Concomitant Posterior Hip Dislocation, Ipsilateral Intertrochanteric- and Proximal Tibial- Fractures with Popliteal Artery Injury: A Challenging Trauma Mélange.

PubMed

Chotai, Pranit N; Ebraheim, Nabil A; Hart, Ryan; Wassef, Andrew

2015-11-05

Constellation of ipsilateral posterior hip dislocation, intertrochanteric- and proximal tibial fracture with popliteal artery injury is rare. Management of this presentation is challenging. A motor vehicle accident victim presented with these injuries, but without any initial signs of vascular compromise. Popliteal artery injury was diagnosed intra-operatively and repaired. This was followed by external fixation of tibial fracture, open reduction of dislocated hip and internal fixation of intertrochanteric fracture. Patient regained bilateral complete weight bearing and returned to pre-accident activity level. Apt surgical management including early repair of vascular injury in such a trauma mélange allows for a positive postoperative outcome.

Comparison and analysis of reoperations in two different treatment protocols for trochanteric hip fractures - postoperative technical complications with dynamic hip screw, intramedullary nail and Medoff sliding plate.

PubMed

Paulsson, Johnny; Stig, Josefine Corin; Olsson, Ola

2017-08-24

In treatment of unstable trochanteric fractures dynamic hip screw and Medoff sliding plate devices are designed to allow secondary fracture impaction, whereas intramedullary nails aim to maintain fracture alignment. Different treatment protocols are used by two similar Swedish regional emergency care hospitals. Dynamic hip screw is used for fractures considered as stable within the respective treatment protocol, whereas one treatment protocol (Medoff sliding plate/dynamic hip screw) uses biaxial Medoff sliding plate for unstable pertrochanteric fractures and uniaxial Medoff sliding plate for subtrochanteric fractures, the second (intramedullary nail/dynamic hip screw) uses intramedullary nail for subtrochanteric fractures and for pertrochanteric fractures with intertrochanteric comminution or subtrochanteric extension. All orthopedic surgeries are registered in a regional database. All consecutive trochanteric fracture operations during 2011-2012 (n = 856) and subsequent technical reoperations (n = 40) were derived from the database. Reoperations were analysed and classified into the categories adjustment (percutaneous removal of the locking screw of the Medoff sliding plate or the intramedullary nail, followed by fracture healing) or minor, intermediate (reosteosynthesis) or major (hip joint replacement, Girdlestone or persistent nonunion) technical complications. The relative risk of intermediate or major technical complications was 4.2 (1.2-14) times higher in unstable pertrochanteric fractures and 4.6 (1.1-19) times higher in subtrochanteric fractures with treatment protocol: intramedullary nail/dynamic hip screw, compared to treatment protocol: Medoff sliding plate/dynamic hip screw. Overall rates of intermediate and major technical complications in unstable pertrochanteric and subtrochanteric fractures were with biaxial Medoff sliding plate 0.68%, with uniaxial Medoff sliding plate 1.4%, with dynamic hip screw 3.4% and with intramedullary nail 7.2%. The treatment protocol based on use of biaxial Medoff sliding plate for unstable pertrochanteric and uniaxial Medoff sliding plate for subtrochanteric fractures reduced the risk of severe technical complications compared to using the treatment protocol based on dynamic hip screw and intramedullary nail.

Mortality rates of patients with a hip fracture in a southwestern district of Greece: ten-year follow-up with reference to the type of fracture.

PubMed

Karagiannis, A; Papakitsou, E; Dretakis, K; Galanos, A; Megas, P; Lambiris, E; Lyritis, G P

2006-02-01

Increased mortality after a hip fracture has been associated with age, sex, and comorbidity. In order to estimate the long-term mortality with reference to hip fracture type, we followed 499 patients older than 60 years who had been treated surgically for a unilateral hip fracture for 10 years. At admission, patients with femoral neck fractures (n = 172) were 2 years younger than intertrochanteric patients (77.6 +/- 7.7 [SD] vs. 79.9 +/- 7.4 [SD], P = 0.001) and had a greater prevalence of heart failure (57% vs. 40.3%, P = 0.03). Similar mortality rates were observed at 1 year in both types of fracture (17.9% vs. 11.3%, log rank test P = 0.112). Mortality rates were significantly higher for intertrochanteric fractures at 5 years (48.8% vs. 34.7%, P = 0.01) and 10 years (76% vs. 58%, P = 0.001). Patients 60-69 years old with intertrochanteric fractures had significantly higher 10-year mortality than patients of similar age with femoral neck fractures (P = 0.008), while there was no difference between the groups aged 70-79 (P > 0.3) and 80-89 (P = 0.07). Women were less likely to die in 5 years (relative risk [RR] = 0.57, 95% confidence interval [CI] 0.41-0.79, P = 0.0007) and 10 years (RR = 0.65, 95% CI 0.49-0.85, P = 0.002). Age, sex, the type of fracture, and the presence of heart failure were independent predictors of 10-year mortality (Cox regression model P < 0.0001). The intertrochanteric type was independently associated with 1.37 (95% CI 1.03-1.83) times higher probability of death at 10 years (P = 0.002). In conclusion, the type of fracture is an independent predictor of long-term mortality in patients with hip fractures, and the intertrochanteric type yields worse prognosis.

Innovations in the management of hip fractures.

PubMed

Teasdall, Robert D; Webb, Lawrence X

2003-08-01

Hip fractures include fractures of the head, neck, intertrochanteric, and subtrochanteric regions. Head fractures commonly accompany dislocations. Neck fractures and intertrochanteric fractures occur with greatest frequency in elderly patients with a low bone mineral density and are produced by low-energy mechanisms. Subtrochanteric fractures occur in a predominantly strong cortical osseous region that is exposed to large compressive stresses. Implants used to address these fractures must accommodate significant loads while the fractures consolidate. Complications secondary to hip fractures produce significant morbidity and include infection, nonunion, malunion, decubitus ulcers, fat emboli, deep venous thrombosis, pulmonary embolus, pneumonia, myocardial infarction, stroke, and death.

Comparison of Intertrochanteric Fracture Fixation with Dynamic Hip Screw and Bipolar Hemiarthroplasty Techniques

PubMed Central

Emami, Mohamad; Manafi, Alireza; Hashemi, Behrooz; Nemati, Ali; Safari, Saeed

2013-01-01

Background: At present, there is no consensus on an appropriate treatment modality for intertrochanteric fractures in the elderly with background diseases. The aim of the present study was to compare treatment outcomes of intertrochanteric fractures reduced with dynamic hip screws (DHS) and bipolar hemiarthroplasty in elderly patients with background medical conditions. Methods: In this randomized clinical trial, 60 patients with intertrochanteric fractures, who were 45-60 years old, were randomly divided into DHS and bipolar groups. After treatment, the two groups were compared in relation to complications and mortality rates, functional status using the Harris Hip Score (HHS), range of movement and severity of pain using the visual analogue score (VAS). Results: HHS (86±9 vs. 75±7.6), range of flexion (105±11 degrees vs. 90±17 degrees) and external rotation (35±7 degrees vs. 20±7 degrees) were significantly higher in the bipolar group compared to the DHS group (P<0.05). However, there were no significant differences in pain severity between the two groups. Conclusion: Reduction of intertrochanteric fractures in elderly patients with background medical conditions is more effective and less problematic with the bipolar technique compared to DHS and is better tolerated by patients, because this technique is associated with improvements in functional status and hip joint movement range. PMID:25207277

Proximal femoral fractures.

PubMed

Webb, Lawrence X

2002-01-01

Fractures of the proximal femur include fractures of the head, neck, intertrochanteric, and subtrochanteric regions. Head fractures commonly accompany dislocations. Neck fractures and intertrochanteric fractures occur with greatest frequency in elderly patients with a low bone mineral density and are produced by low-energy mechanisms. Subtrochanteric fractures occur in a predominantly strong cortical osseous region which is exposed to large compressive stresses. Implants used to address these fractures must be able to accommodate significant loads while the fractures consolidate. Complications secondary to these injuries produce significant morbidity and include infection, nonunion, malunion, decubitus ulcers, fat emboli, deep venous thrombosis, pulmonary embolus, pneumonia, myocardial infarction, stroke, and death.

Interpretation of hip fracture patterns using areal bone mineral density in the proximal femur.

PubMed

Hey, Hwee Weng Dennis; Sng, Weizhong Jonathan; Lim, Joel Louis Zongwei; Tan, Chuen Seng; Gan, Alfred Tau Liang; Ng, Jun Han Charles; Kagda, Fareed H Y

2015-12-01

Bone mineral density scans are currently interpreted based on an average score of the entire proximal femur. Improvements in technology now allow us to measure bone density in specific regions of the proximal femur. The study attempts to explain the pathophysiology of neck of femur (NOF) and intertrochanteric/basi-cervical (IT) fractures by correlating areal BMD (aBMD) scores with fracture patterns, and explore possible predictors for these fracture patterns. This is a single institution retrospective study on all patients who underwent hip surgeries from June 2010 to August 2012. A total of 106 patients (44 IT/basi-cervical, 62 NOF fractures) were studied. The data retrieved include patient characteristics and aBMD scores measured at different regions of the contralateral hip within 1 month of the injury. Demographic and clinical characteristic differences between IT and NOF fractures were analyzed using Fisher's Exact test and two-sample t test. Relationship between aBMD scores and fracture patterns was assessed using multivariable regression modeling. After adjusted multivariable analysis, T-Troc and T-inter scores were significantly lower in intertrochanteric/basi-cervical fractures compared to neck of femur fractures (P = 0.022 and P = 0.026, respectively). Both intertrochanteric/basi-cervical fractures (mean T.Tot -1.99) and neck of femur fractures (mean T.Tot -1.64) were not found to be associated with a mean T.tot less than -2.5. However, the mean aBMD scores were consistently less than -2.5 for both intertrochanteric/basi-cervical fractures and neck of femur fractures. Gender and calcium intake at the time of injury were associated with specific hip fracture patterns (P = 0.002 and P = 0.011, respectively). Hip fracture patterns following low energy trauma may be influenced by the pattern of reduced bone density in different areas of the hip. Intertrochanteric/basi-cervical fractures were associated with significantly lower T-Troc and T-Inter scores compared to neck of femur fractures, suggesting that the fracture traversed through the areas with the lowest bone density in the proximal femur. In the absence of reduced T.Troc and T.Inter, neck of femur fractures occurred more commonly. T-Total scores may underestimate the severity of osteoporosis/osteopenia and measuring T-score at the neck of femur may better reflect the severity of osteoporosis and likelihood of a fragility fracture.

Does integrity of the lesser trochanter influence the surgical outcome of intertrochanteric fracture in elderly patients?

PubMed

Liu, Xiaohui; Liu, Yueju; Pan, Shuo; Cao, Huijian; Yu, Dahai

2015-03-05

Most surgeons do not fix the lesser trochanter when managing femoral intertrochanteric fractures with intramedullary nails. We have not found any published clinical studies on the relationship between the integrity of the lesser trochanter and surgical outcomes of intertrochanteric fractures treated with intramedullary nails. The purpose of this study was to evaluate the impact of the integrity of the lesser trochanter on the surgical outcome of intertrochanteric fractures. A retrospective review of 85 patients aged more than 60 years with femoral intertrochanteric fractures from January 2010 to July 2012 was performed. The patients were allocated to two groups: those with (n = 37) and without (n = 48) preoperative integrity of the lesser trochanter. Relevant patient variables and medical comorbidities were collected. Medical comorbidities were evaluated according to the American Society of Anesthesiologists classification and medical records were also reviewed for age, sex, time from injury to operation, intraoperative blood loss, volume of transfusion, operative time, length of stay, time to fracture union, Harris Hip Score 1 year postoperatively, and incidence of postoperative complications. Postoperative complications included deep infection (beneath the fascia lata), congestive heart failure, pulmonary embolus, cerebrovascular accident, pneumonia, cardiac arrhythmia, urinary tract infection, wound hematoma, pressure sores, delirium, and deep venous thrombosis. Variables were statistically compared between the two groups, with statistical significance at P<0.05. Patients with and without preoperative integrity of the lesser trochanter were comparable for all assessed clinical variables except fracture type (P < 0.05). There were no statistically significant differences between these groups in time from injury to operation, volume of transfusion, length of stay, time to fracture union, Harris Hip Score at 1 year postoperatively, and incidence of postoperative complication (P > 0.05). The group with preoperative integrity of the lesser trochanter had significantly less blood loss (107.03 ± 49.21 mL) than those without it (133.96 ± 58.08 mL) (P < 0.05) and the operative time was significantly shorter in the former (0.77 ± 0.07 hours) than the latter (0.84 ± 0.11 hours) group (P < 0.05). The integrity of the lesser trochanter has no significant influence on the surgical outcome of intramedullary nail internal fixation of femoral intertrochanteric fractures.

External fixation of "intertrochanteric" fractures.

PubMed

Gani, Naseem Ul; Kangoo, Khursheed Ahmed; Bashir, Arshad; Muzaffer, Rahil; Bhat, Mohammad Farooq; Farooq, Munir; Badoo, Abdul Rashid; Dar, Imtiyaz Hussian; Wani, Mudassir Maqbool

2009-10-10

In developing countries, due to limited availability of modern anesthesia and overcrowding of the hospitals with patients who need surgery, high-risk patients with "intertrochanteric" fractures remain unsuita ble for open reduction and internal fixation.The aim of this study was to analyze the results of external fixation of "intertrochanteric" fractures in high-risk geriatric patients in a developing country.The results of 62 ambulatory high-risk geriatric patients with a mean age of 70 years (range 58-90 years) with "intertrochanteric" fractures, in whom external fixation was performed, are reported.Eight patients died during follow-up due to medical causes unrelated to the surgical procedure. So only 54 patients were available for final assessment. Procedure is simple, performed under local anesthesia, requires less time for surgery and is associated with less blood loss. Good fixation and early ambulation was achieved in most of the patients. Average time to union was 14 weeks. Thirty-one patients developed superficial pin tract infection and 28 patients had average shortening of 15 mm due to impaction and varus angulation. Functional outcome was assessed using Judet's point system. Good to excellent results were achieved in 44 patients.This study demonstrated that external fixation of "intertrochantric" fractures performed under local anesthesia offers significant advantage in ambulatory high-risk geriatric patients especially in a developing country.

[Stress test and clinical application of the minimal-invasive dynamic hip screw].

PubMed

Tong, Song-Lin; Chen, Jian-Lie; Lu, Wen-Jie; Pan, Zhi-Jun; Wang, Yi-Jin

2008-05-01

To recognize the effect of minimal-invasive dynamic hip screw (MIDHS) on the treatment of intertrochanteric fracture of the hip by biomechanical test and preliminary clinical application. Ten artifical made intertrochanteric fractures of femoral specimen from five cadavers were divided into two groups randomly. The fractures in first group were fixed by MIDHS and other group were fixed by dynamic hip (DHS). Biomechanical characteristics of two different devices were compared with the biomechanical character of load-straining, load-displacing, rigidity and strength of femur by statistic analysis. According to the Harris evaluation, healing effect of intertrochanteric fractures was evaluated clinically on the 15 cases. Straining changes of MIDHS were 14% and 11% less than that of DHS on the tensile side and the pressure side respectively; Sinking and horizontal displacement, were 19% and 22% less than that of DHS respectivly. But external and internal stress intensity,axial and bending rigidity were all higher than that of DHS, they were 12%, 11%, 19% and 37%. Maximal destroyed twisting moment (15%) and average twisting rigidity (15%) were both higher than that of DHS, but twisting angle was 18% less. Under the force, of 1 800 N, the open angle of the fracture on transverse section was 2.28 degrees,while the DHS's was 3.60 degrees . The data above were significant differences statistically (P < 0.01). The average Harris score of the 15 cases with intertrochanteric fractures treated by MIDHS was 91, excellent and good rate was 92.7%, without complications of internal fixation failure,postoperative infection and so on. The design of minimal-invasive dynamic hip screw is reasonable and effective against rotating, shearing and varus stress force of the fracture, and it provides possibility of implanting the internal fixation with minimal incision. So it is an ideal internal fixation device for the treatment of intertrochanteric fractures.

Complications of short versus long cephalomedullary nail for intertrochanteric femur fractures, minimum 1 year follow-up.

PubMed

Vaughn, Josh; Cohen, Eric; Vopat, Bryan G; Kane, Patrick; Abbood, Emily; Born, Christopher

2015-05-01

Hip fractures are becoming increasingly common resulting in significant morbidity, mortality and raising healthcare costs. Both short and long cephalomedullary devices are currently employed to treat intertrochanteric hip fractures. However, which device is optimal continues to be debated as each implant has unique characteristics and theoretical advantages. This study looked to identify rates of complications associated with both long and short cephalomedullary nails for the treatment of intertrochanteric hip fractures. We retrospectively reviewed charts from 2006 to 2011, and we identified 256 patients were identified with AO class 31.1-32.3 fractures. Sixty were treated with short nails and 196 with long nails. Radiographs and charts were then analysed for failures and hardware complications. Catastrophic failure and hardware complication rates were not statistically different between short or long cephalomedullary nails. The overall catastrophic failure rate was 3.1 %; there was a 5 % failure rate in the short-nail group compared with a 2.6 % failure rate in the long-nail group (p = 0.191). There was a 3.33 % secondary femur fracture rate in the short-nail group, compared with none in the long-nail cohort (p = 0.054). The rate of proximal fixation failure was 1.67 % for the short-nail group and 2.0 % in the long-nail group (p = 0.406). Our data suggests equivocal outcomes as measured by similar catastrophic failure rate between both short and long cephalomedullary nails for intertrochanteric femur fractures. However, there was an increased risk of secondary femur fracture with short cephalomedullary nails when compared to long nails that approached statistical significance.

Surgical Results of the Cephalomedullary Nail for the Femoral Intertrochanteric Fracture: Comparison between Non-experienced Surgeons and Experienced Surgeon

PubMed Central

Seo, Jae-Seong; Min, Hak-Jin; Kim, Dong Min; Oh, Seung-Min

2016-01-01

Purpose Cephalomedullary nail (CM nail) in the treatment of femoral intertrochanteric fractures is in the lime light in recent years. The purpose of this study is to compare surgical outcomes between experienced surgeon and non-experienced surgeons in respect of CM nail for femoral intertrochanteric fractures. Materials and Methods The 129 patients underwent CM nail for femoral intertrochanteric fracture more than six months of follow-up from April 2011 to March 2014 in Seoul Medical Center (Seoul, Korea) were participated in this study. For this study, group A consisted of experienced surgeons who performed more than 500 times of CM nail, and group B consisted of non-experienced surgeons who performed less than 50 times of CM nail. Clinical and radiologic outcomes, complications and the need for reoperation between both groups were compared in the study. Results According to clinical result, both the mean operation time and transfusion volume were significantly longer and greater in group B (P<0.05). In the radiologic outcomes, adequacy of reduction, tip-apex distance and numbers of case placed in the Cleveland zones 5, 6 and 8; there was no statistical difference between both groups. Moreover, rate of complication and reoperation had same results as radiologic outcomes. Conclusion There was no significant difference with statistical data in complications from CM nail for femoral intertrochanteric fractures between experienced surgeon and non-experienced surgeon. Although the operation time and transfusion volume were significantly longer and greater in the case of operation by non-experienced surgeon, satisfactory performance was seen in the complications and the need for reoperation. PMID:28097112

Influence of Regional Difference in Bone Mineral Density on Hip Fracture Site in Elderly Females by Finite Element Analysis.

PubMed

Lin, Z L; Li, P F; Pang, Z H; Zheng, X H; Huang, F; Xu, H H; Li, Q L

2015-11-01

Hip fracture is a kind of osteoporotic fractures in elderly patients. Its important monitoring indicator is to measure bone mineral density (BMD) using DXA. The stress characteristics and material distribution in different parts of the bones can be well simulated by three-dimensional finite element analysis. Our previous studies have demonstrated a linear positive correlation between clinical BMD and the density of three-dimensional finite element model of the femur. However, the correlation between the density variation between intertrochanteric region and collum femoris region of the model and the fracture site has not been studied yet. The present study intends to investigate whether the regional difference in the density of three-dimensional finite element model of the femur can be used to predict hip fracture site in elderly females. The CT data of both hip joints were collected from 16 cases of elderly female patients with hip fractures. Mimics 15.01 software was used to reconstruct the model of proximal femur on the healthy side. Ten kinds of material properties were assigned. In Abaqus 6.12 software, the collum femoris region and intertrochanteric region were, respectively, drawn for calculating the corresponding regional density of the model, followed by prediction of hip fracture site and final comparison with factual fracture site. The intertrochanteric region/collum femoris region density was [(1.20 ± 0.02) × 10(6)] on the fracture site and [(1.22 ± 0.03) × 10(6)] on the non-fracture site, and the difference was statistically significant (P = 0.03). Among 16 established models of proximal femur on the healthy side, 14 models were consistent with the actual fracture sites, one model was inconsistent, and one model was unpredictable, with the coincidence rate of 87.5 %. The intertrochanteric region or collum femoris region with lower BMD is more prone to hip fracture of the type on the corresponding site.

The Role of Radiographs and Office Visits in the Follow-Up of Healed Intertrochanteric Hip Fractures: An Economic Analysis.

PubMed

Kempegowda, Harish; Richard, Raveesh; Borade, Amrut; Tawari, Akhil; Howenstein, Abby M; Kubiak, Erik N; Suk, Michael; Horwitz, Daniel S

2016-12-01

The purpose of this study was to evaluate the role and the necessity of radiographs and office visits obtained during follow-up of intertrochanteric hip injuries. Retrospective study. Two level I trauma centers. Four hundred sixty-five elderly patients who were surgically treated for an intertrochanteric fracture of the femur at 2 level I trauma centers between January 2009 and August 2014 were retrospectively identified from orthopaedic trauma databases. Analysis of all healed intertrochanteric hip fractures, including demographic characteristics, quality of reduction, time of healing, number of office visits, number of radiographs obtained, and each radiograph for fracture alignment, implant position or any pathological changes. The surgical fixation of 465 fractures included 155 short nails (33%), 232 long nails (50%), 69 sliding hip screw devices (15%), 7 trochanteric stabilizing plates (1.5%), and 2 proximal femur locking plates (0.5%). The average fracture healing time was 12.8 weeks and the average follow-up was 81.2 weeks. Radiographs of any patient obtained after the fracture had healed did not reveal any changes, including fracture alignment or implant position and hardware failure. In 9 patients, pathological changes, including arthritis (3), avascular necrosis (3), and ectopic ossification (3) were noted. The average number of elective office visits and radiographs obtained after the fracture had healed were 2.8 (range: 1-8) and 2.6 (range: 1-8), respectively. According to Medicare payments to the institution, these radiographs and office visits account for a direct cost of $360.81 and $192, respectively, per patient. The current study strongly suggests that there is a negligible role for radiographs and office visits during the follow-up of a well-healed hip fracture when there is documented evidence of radiographic and clinical healing with acceptable fracture alignment and implant position. Implementation of this simple measure will help in reducing the cost of care and inconvenience to elderly patients. Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Resident Participation in Fixation of Intertrochanteric Hip Fractures: Analysis of the NSQIP Database.

PubMed

Neuwirth, Alexander L; Stitzlein, Russell N; Neuwirth, Madalyn G; Kelz, Rachel K; Mehta, Samir

2018-01-17

Future generations of orthopaedic surgeons must continue to be trained in the surgical management of hip fractures. This study assesses the effect of resident participation on outcomes for the treatment of intertrochanteric hip fractures. The National Surgical Quality Improvement Program (NSQIP) database (2010 to 2013) was queried for intertrochanteric hip fractures (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] code 820.21) treated with either extramedullary (Current Procedural Terminology [CPT] code 27244) or intramedullary (CPT code 27245) fixation. Demographic variables, including resident participation, as well as primary (death and serious morbidity) and secondary outcome variables were extracted for analysis. Univariate, propensity score-matched, and multivariate logistic regression analyses were performed to evaluate outcome variables. Data on resident participation were available for 1,764 cases (21.0%). Univariate analyses for all intertrochanteric hip fractures demonstrated no significant difference in 30-day mortality (6.3% versus 7.8%; p = 0.264) or serious morbidity (44.9% versus 43.2%; p = 0.506) between the groups with and without resident participation. Multivariate and propensity score-matched analyses gave similar results. Resident involvement was associated with prolonged operating-room time, length of stay, and time to discharge when a prolonged case was defined as one above the 90th percentile for time parameters. Resident participation was not associated with an increase in morbidity or mortality but was associated with an increase in time-related secondary outcome measures. While attending surgeon supervision is necessary, residents can and should be involved in the care of these patients without concern that resident involvement negatively impacts perioperative morbidity and mortality. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Osteosynthesis of fractures of the femur with flexible metallic intramedullary nails.

PubMed

Firica, A; Troianescu, O; Petre, M

1978-04-01

The authors discuss their use of Ender's method in the treatment of fractures of the femur. The diameter and length of the nails depends on the type of fracture. 1) Three nails of 4 mm diameter are introduced in parallel from the medial condyle in fractures of the femoral neck; 2) 5 mm nails are used, in similar fashion, for the fixation of intertrochanteric and subtrochanteric fractures; 3) 5 mm nails are used for diaphyseal, supracondylar and intercondylar fractures, introduced in crossed fashion ("Eiffel Tower" technique) from both medial and lateral condyles. This method of fixation has proved to be extremely stable. The operation itself is quick, with no blood loss or shock. The patient can resume partial weight bearing after a week in stabilised intertrochanteric and shaft fractures, after a month in less stable types, and after three to four months in fractures of the neck of the femur. This report is based on the first 250 cases treated by this method.

[Clinical observation of proximal femoral anti-rotation nail for the treatment of femoral intertrochanteric fracture].

PubMed

Sun, Fang-Gui; Wang, De-Xin; Hu, Yu-Tong; Xu, Rong-Ming

2017-10-25

To explore the curative effect and the recessive loss of blooding of PFNA for the treatment of intertrochanteric fractures of femur. From January 2012 to January 2015, a total of 49 patients with intertrochanteric fractures of femur were treated with proximal femoral anti-rotation nail including 41 males and 8 females with an average age of 79 years old ranging from 65 to 91 years old. According to the modified Evans type, 1 case was type I, 12 cases were type II, 36 cases were type III. All cases were fresh fractures. Patients had hip pain, movement limited, joint swelling, bruising, extorsion deformity, X-ray and CT examination showed completely fractures. All patients were treated by closed reduction and PFNA internal fixation. Three comminuted fractures using closed reduction were not satisfied, then were treated by limited PFNA fixation after open reduction. The patients' incision got the grade A healing, no complications such as infection and internal fixation failure happened. All patients were followed up from 6 to 36 months (means 22 months). The pain VAS score decreased from preoperative 7.70±1.97 to 1.00±0.26 at 6 months after operation( P <0.01). Harris hip score improved from preoperative 8.70±4.19 to 91.70±5.31 at 6 months after operation( P <0.01). The outcome at 6 months after operation was excellent in 34 cases, good in 7, poor in 1. The fracture healing time was from 8 to 16 weeks with an average of 12 weeks after operation. One patient with osteoporosis, crushing broken, poor compliance, associated with schizophrenia at the same time, appeared with the displacement of the femoral greater trochanter, with conservative treatment for healing. Intertrochanteric fractures of femur are common in the elderly trauma, in pain relief, recovery of hip function, to provide quality of life for the patients, PFNA achieved satisfactory effect, but its existence is worth to pay close attention to the recessive loss of blood.

[Curative effect analysis on closed reduction and external fixator under local anesthesia for the treatment of intertrochanteric fracture in elderly patients with high-risk].

PubMed

Wang, Zeng-ping; Liu, Lin; Xue, Wen; Zhou, Hui-ru; Song, Yu-xin; Cai, Li-yang; Cheng, Xian-tang; Qian, Yao-wen

2016-06-01

To explore clinical efficacy of closed reduction and external fixation under local anesthesia for the treatment of high-risk elderly patients with intertrochanteric fracture. From March 2013 to March 2015, 10 patients with intertrochanteric fractures treated with closing reduction and external fixator under local anesthesia were analyszed, including 4 males and 6 females, aged from 69 to 88 years old with an average of 75.2 years old. All fractures were caused by injury and classified to type I (5 cases), II (3 cases), and V (2 cases) according to Evans classification. According to American Society of Anesthesiologists (ASA), 6 cases were type III and 4 cases were type IV. Blood loss,operative time,hospital stays, postoperative complications, ambulation time and fracture healing time were observed, and Harris scoring were used to evaluate hip joint function. All patients were followed up from 3 to 23 months with an average of 13.1 months. One patient with chronic obstructive pulmonary disease died for non-operation reason at 4 months after operation, the other fractures were healed at stage I, the mean fracture healing time was 5.6 months. There were no coxa vara, lower limb venous thrombosis, loosen and remove of needle passage. The average operative time was 46 min, blood loss was (35.00 ± 8.46) ml without blood transfusion. One patient was occurred pulmonary infection and stent-tract infection on the 2 nd and 3 rd day after operation, and improved with active anti-infection and dressing change; the other patients gone to ground activity at 4.2 d after operation. The patients stayed hospital for 10.6 d on average. According to Harris scoring at final following-up, the total score was 83.42 ± 3.27, 3 cases obtained excellent results, 5 cases good and 1 case poor. Closed reduction and external fixation under local anesthesia in treating high-risk elderly patients with intertrochanteric fracture,which has advantages of shorter operative time, less blood loss, good recovery of postoperative function, is a safe, stable and economic method.

Undisplaced Intraoperative Fracture Presenting as Early Dislocation with Tapered Wedge Stems in Total Hip Arthroplasty - Case Series and Review of Literature

PubMed Central

Reddy, A V Gurava; Eachempati, Krishna Kiran; Mugalur, Aakash; Suchinder, A; Rao, V B N Prasad; Kamurukuru, Nalanda

2017-01-01

Introduction: Periprosthetic fractures and dislocation in the early post-operative period can be disastrous both for the surgeon and the patient. However, undisplaced periprosthetic fractures presenting with dislocation is uncommon. We describe successful management of two cases (one bilateral dislocation and one unilateral dislocation) of undisplaced iatrogenic fractures in total hip arthroplasty (THA) presenting as early dislocation. Case Report: Case 1 was a 45-year-old female with osteoarthritis of hip secondary to developmental dysplasia of the hip with bilateral early nontraumatic dislocation with bilateral identical periprosthetic fracture. It was managed by revision to long stem and encirclage wiring. Case 2 presented with early dislocation in the 2nd week post THA. We found an intertrochanteric fracture intra-operatively with unstable implant. Acetabular component and femoral component revision were done with reconstruction of the greater trochanter. Discussion: These fractures could be occult iatrogenic fractures characteristic of taper wedge stems which presented as early nontraumatic dislocation in the post-operative period. The prosthesis subsidence, loss of muscle tension and change of version might be the factors leading to dislocation. Conclusion: Unrecognized incomplete intraoperative fracture can occur with tapered wedge uncemented stems which can present as a dislocation in the immediate post-operative period. This will require early revision of the femoral component. PMID:29051875

Adherence to oral bisphosphonates and the risk of subtrochanteric and femoral shaft fractures among female medicare beneficiaries

PubMed Central

Wang, Z.; Ward, M. M.; Chan, L.

2014-01-01

Summary Previous studies have shown an association between duration of bisphosphonate use and atypical femur fractures. This cohort study showed an increasingly higher risk of subtrochanteric and femoral shaft fractures among those who were more adherent to oral bisphosphonates. Introduction Long-term use of oral bisphosphonates has been implicated in an increased risk of atypical femur fractures located in subtrochanteric and femoral shaft regions. Another measure of drug exposure, medication adherence, however, has not been investigated. Methods Among all Medicare fee-for-service female beneficiaries from 2006–2010, we followed 522,287 new bisphosphonate users from their index prescription until being censored or having a primary diagnosis of closed subtrochanteric/ femoral shaft or intertrochanteric/femoral neck fractures. Data about radiographs of fracture site and features were not available. Adherence was classified according to the medication possession ratio (MPR) as the following: MPR<1/3 as less compliant, MPR≥1/3–<2/3 as compliant, and MPR≥2/3 as highly compliant. Alternative cutoff points at 50 and 80 % were also used. Survival analysis was used to determine the cumulative incidence and hazard of subtrochanteric/femoral shaft or intertrochanteric/femoral neck fractures. Results There was a graded increase in incidence of subtrochanteric/femoral shaft fractures as the level of adherence increased (Gray’s test, P<0.001). The adjusted hazard ratio (HR) for the highly compliant vs. the less compliant was 1.23 (95 % Confidence Interval [CI] 1.06–1.43) overall, became significant after 2 years of follow-up (HR=1.51, 95 % CI 1.06–2.15) and reached the highest risk in the fifth year (HR=4.06, 95 % CI 1.47–11.19). However, age-adjusted incidence rates of intertrochanteric/femoral neck fractures were significantly lower among highly compliant beneficiaries, compared to less compliant users (HR=0.69, 95 % CI 0.66–0.73). Similar results were obtained when the cutoff points for being compliant and highly compliant were set at 50 and 80 %, respectively. Conclusions Subtrochanteric/femoral shaft fractures, unlike intertrochanteric/femoral neck fractures, are positively associated with higher adherence to long-term (≥3 years) oral bisphosphonates in the elderly female Medicare population. PMID:24846316

Effectiveness of treatment of transtrochanteric fractures with Dynamic Hip Screws using minimally invasive access☆

PubMed Central

de Abreu, Eduardo Lima; Sena, Caroline Brum; Saldanha Rodrigues Filho, Sergio Antonio

2016-01-01

Objective To analyze the short-term results from treating unstable intertrochanteric fractures with Dynamic Hip Screws (DHS), using a minimally invasive route, focusing on the functional aspects and complication and mortality rates of the method. Methods This was a prospective longitudinal study on 140 patients who underwent fixation of transtrochanteric fractures with the DHS system with a lateral minimally invasive access in the hip, between January and December 2013. The patients were evaluated pre and postoperatively (after six months of follow-up) by means of the Parker and Palmer mobility score. Women comprised 65.7% of the sample, and 54.3% of the fractures were on the right side. The patients’ mean age was 80 years, ranging from 60 to 93 years. Results We observed an overall decrease in the mobility score and an increase in the degree of dependence over the short term. However, we encountered only two deaths in the study sample and there were no cases of infection or nonunion. Conclusion Despite the efficacy of the treatment with DHS, with high rates of fracture consolidation and a low mortality rate, we noted that the patients still showed significant functional limitation at the follow-up six months after the operation. PMID:27069880

Classification of intertrochanteric fractures with computed tomography: a study of intraobserver and interobserver variability and prognostic value.

PubMed

Chapman, Cary B; Herrera, Mauricio F; Binenbaum, Gil; Schweppe, Michael; Staron, Ronald B; Feldman, Frieda; Rosenwasser, Melvin P

2003-09-01

The purpose of this prospective study was to determine the level of interobserver and intraobserver agreement among orthopedic surgeons and radiologists when computed tomography (CT) scans are used with plain radiographs to evaluate intertrochanteric fractures. In addition, the prognostic value of current classifications systems concerning quality of life was evaluated. Sixty-one patients who presented with intertrochanteric fractures received open reduction and internal fixation with compression hip screw. Three orthopedic surgeons and 2 radiologists independently classified the fractures according to 2 systems: Evans-Jensen and AO (Arbeitsgemeinschaft für Osteo-synthesefragen). Fractures were initially graded with plain radiographs and then again in conjunction with CT. Results were analyzed using the (kappa) kappa coefficient. The 36-item Short-Form Health Survey was administered at baseline, 3 months, and 1 year, and results were correlated with fracture grade. Mean kappa coefficients when comparing radiography alone with radiography and CT scan were 0.63 for the AO system and 0.59 for the Evans-Jensen system. Both represent "fair" agreements. Mean overall interobserver kappa coefficients were 0.67 for radiologists and 0.57 for orthopedic surgeons. Radiologists also had higher intraobserver kappa coefficients. No significant relationships were found between follow-up Short Form Health Survey results and intraoperative grading of fractures. When these classification schemes are compared, interobserver agreement does not appear to change dramatically when information from CT scans is added. This may suggest that (1) more data have been provided by CT with greater possibilities for misinterpretation and (2) these classification schemes may not be comprehensive in describing fracture pattern and displacement. Finally, both systems failed to provide any prognostic value.

Comparison of the Lag Screw Placements for the Treatment of Stable and Unstable Intertrochanteric Femoral Fractures regarding Trabecular Bone Failure.

PubMed

Celik, Talip; Mutlu, Ibrahim; Ozkan, Arif; Kisioglu, Yasin

2016-01-01

Background. In this study, the cut-out risk of Dynamic Hip Screw (DHS) was investigated in nine different positions of the lag screw for two fracture types by using Finite Element Analysis (FEA). Methods. Two types of fractures (31-A1.1 and A2.1 in AO classification) were generated in the femur model obtained from Computerized Tomography images. The DHS model was placed into the fractured femur model in nine different positions. Tip-Apex Distances were measured using SolidWorks. In FEA, the force applied to the femoral head was determined according to the maximum value being observed during walking. Results. The highest volume percentage exceeding the yield strength of trabecular bone was obtained in posterior-inferior region in both fracture types. The best placement region for the lag screw was found in the middle of both fracture types. There are compatible results between Tip-Apex Distances and the cut-out risk except for posterior-superior and superior region of 31-A2.1 fracture type. Conclusion. The position of the lag screw affects the risk of cut-out significantly. Also, Tip-Apex Distance is a good predictor of the cut-out risk. All in all, we can supposedly say that the density distribution of the trabecular bone is a more efficient factor compared to the positions of lag screw in the cut-out risk.

[EFFECTIVENESS COMPARISON OF PROXIMAL FEMORAL NAIL ANTI-ROTATION IN SUPINE "SCISSORS" POSITION AND IN LITHOTOMY POSITION TO TREAT FEMORAL INTERTROCHANTERIC FRACTURES OF OLD PATIENTS].

PubMed

Du, Shihao; Yin, Fei; Wei, Xuming; Song, Sheng; Gu, Sanjun; Sun, Zhenzhong; Rui, Yongjun

2016-02-01

To compare the effectiveness of proximal femoral nail anti-rotation (PFNA) between in the supine "scissors" position and in the lithotomy position for treating femoral intertrochanteric fractures of old patients. A retrospective study was performed on 58 patients with femoral intertrochanteric fractures treated with PFNA between January 2013 and January 2015. Fracture was treated with PFNA in the lithotomy position in 28 cases (group A) and in the supine "scissors" position in 30 cases (group B). There was no significant difference in gender, age, side, cause of injury, fracture type, and interval from injury to operation between 2 groups (P>0.05). The incision length, operation time, perspective times, intraoperative blood loss, complications, and fracture healing time were recorded; Harris hip score was used to access the effectiveness. The wound healed by first intention without infection, pressure sores, deep vein thrombosis of lower extremity, and other complications. There was no significant difference in incision length between 2 groups (t=1.313, P=0.212). Group B was significantly better than group A in operation time, perspective times, and intraoperative blood loss (P<0.05). All patients were followed up 10-31 months (mean, 15.3 months). Stretch injury at normal side and perineal discomfort occurred in 1 case and 5 cases of group A respectively, and no nonunion and other complications was observed in the other patients. There was no significant difference in fracture healing time and Harris hip score at last follow-up between 2 groups (P>0.05). PFNA in the supine "scissors" position has exact effectiveness and advantages of shorter operation time, less intraoperative blood loss, less perspective times, and fewer complications.

Application of 3D printing rapid prototyping-assisted percutaneous fixation in the treatment of intertrochanteric fracture.

PubMed

Zheng, Sheng-Nai; Yao, Qing-Qiang; Mao, Feng-Yong; Zheng, Peng-Fei; Tian, Shu-Chang; Li, Jia-Yi; Yu, Yi-Fan; Liu, Shuai; Zhou, Jin; Hu, Jun; Xu, Yan; Tang, Kai; Lou, Yue; Wang, Li-Ming

2017-10-01

The aim of the present study was to investigate the application of 3D printing (3DP) rapid prototyping (RP) technique-assisted percutaneous fixation in the treatment of femoral intertrochanteric fracture (ITF) using proximal femoral nail anti-rotation (PFNA). A total of 39 patients with unstable ITF were included in the current study. Patients were divided into two groups: 19 patients were examined using computed tomography scanning and underwent PFNA with SDP-RP whereas the other 20 patients underwent conventional PFNA treatment. Anatomical data were converted from the Digital Imaging and Communications in Medicine format to the stereolithography format using M3D software. The 3DP-RP model was established using the fused deposition modeling technique and the length and diameter of the main screw blade was measured during the simulation. The postoperative femoral neck-shaft angle (NSA), surgery duration, intraoperative and postoperative blood loss, and the duration of hospital stay were recorded and compared with the corresponding values in conventional surgery. No significant differences were observed in mean PFNA size between the implants used and the preoperative planning estimates. It was demonstrated that the 3DP-RP assisted procedure resulted in more effective reduction of the NSA. Furthermore, patients undergoing 3DP-RP experienced a significant reduction in duration of surgery (P<0.01), as well as reductions in intraoperative (P=0.02) and postoperative (P=0.03) blood loss, compared with conventional surgery. At 6 months post-surgery, no cases of hip varus/vague deformities or implant failure were observed in patients that underwent either the 3DP-RP-assisted or conventional procedure. The results of the present study suggest that the 3DP-RP technique is able to create an accurate model of the ITF, which facilitates surgical planning and fracture reduction, thus improving the efficiency of PFNA surgery for ITFs.

Comparison of the Lag Screw Placements for the Treatment of Stable and Unstable Intertrochanteric Femoral Fractures regarding Trabecular Bone Failure

PubMed Central

Mutlu, Ibrahim; Ozkan, Arif; Kisioglu, Yasin

2016-01-01

Background. In this study, the cut-out risk of Dynamic Hip Screw (DHS) was investigated in nine different positions of the lag screw for two fracture types by using Finite Element Analysis (FEA). Methods. Two types of fractures (31-A1.1 and A2.1 in AO classification) were generated in the femur model obtained from Computerized Tomography images. The DHS model was placed into the fractured femur model in nine different positions. Tip-Apex Distances were measured using SolidWorks. In FEA, the force applied to the femoral head was determined according to the maximum value being observed during walking. Results. The highest volume percentage exceeding the yield strength of trabecular bone was obtained in posterior-inferior region in both fracture types. The best placement region for the lag screw was found in the middle of both fracture types. There are compatible results between Tip-Apex Distances and the cut-out risk except for posterior-superior and superior region of 31-A2.1 fracture type. Conclusion. The position of the lag screw affects the risk of cut-out significantly. Also, Tip-Apex Distance is a good predictor of the cut-out risk. All in all, we can supposedly say that the density distribution of the trabecular bone is a more efficient factor compared to the positions of lag screw in the cut-out risk. PMID:27995133

The Effect of Skin Traction on Preoperative Pain and Need for Analgesics in Patients With Intertrochanteric Fractures: A Randomized Clinical Trial

PubMed Central

Manafi Rasi, Alireza; Amoozadeh, Farzad; Khani, Salim; Kamrani Rad, Amin; Sazegar, Ali

2015-01-01

Background: Preoperative skin traction is applied for many patients with hip fracture. However, the efficacy of this modality in pain relief is controversial. Objectives: The aim of the current study was to investigate the effects of skin traction on pain in patients with intertrochanteric fractures. Patients and Methods: A total of 40 patients contributed in this randomized clinical trial. Patients were randomly allocated into two equal groups: the skin traction (3 kg) and control groups. The severity of pain was recorded at admission and 30 minutes, one, six, 12, and 24 hours after skin traction application utilizing a Visual Analogue Scale (VAS). In addition, the number of requests for analgesics was recorded. Finally, the mean severity of pain in each measurement and the mean number of analgesic requests were compared between the two groups. Results: The severity of pain was significantly decreased in skin traction group only at the end of the first day after traction application (2.7 ± 0.8 vs. 3.3 ± 0.9; P = 0.042), while there was no significant difference between the two groups in other pain measurements. The number of requests for analgesics was the same between the two groups. Conclusions: Although skin traction had no effect on analgesic consumption, it significantly decreased the pain at the end of the first day. The application of skin traction in patients with intertrochanteric fractures is recommended. PMID:26401491

The prognostic value of tip-to-apex distance (TAD index) in intertrochanteric fractures fixed by dynamic hip screw.

PubMed

Sedighi, Ali; Sales, Jafar Ganjpour; Alavi, Sahar

2012-11-02

Intertrochanteric fractures (ITFs) are the most common type of fractures requiring surgical intervention. They also have the highest surgical mortality among orthopedic operations. Among the many different techniques used for fixation of this type of fracture, use of the Dynamic Hip Screw (DHS) has gained wide acceptance. This current study was designed to assess positive predictive value of tip-to-apex distance (TAD) index in the prognosis of patients treated with DHS. The study was designed according to a descriptive-analytic protocol, made up of 100 cases of ITFs caused by falling, treated in the Shohada Orthopedic Center, Tabriz, Iran. All patients underwent lateral and antero-posterior hip X-ray to measure TAD index. The cohort was followed for three months after DHS placement. Of a total of 100 cases (53 male, 47 female) with a mean age of 76.7 years (range 29-100 years), 43% had grade 4, 29% grade 3, 21% grade 5, 5% grade 2 and 2% grade 6 osteoporosis. The screw position was postero-inferior in 57%, central in 40% and superior in 3% of patients. Minimum and maximum TAD index were 20 and 28 mm, respectively. Mean TAD was 23.5 mm. There were no post-operative complications in 84% of cases. Screw failure was the most common complication in the remaining 16% of patients. The study shows a statistically significant correlation between TAD index and cut-off rate in patients with intertrochanteric fractures of femoral bone treated by DHS. This validates the use of TAD index in determining the prognosis of patients treated by DHS.

Pediatric Hip Fractures in California: Results from a Community-Based Hip Fracture Registry.

PubMed

Prentice, Heather A; Paxton, Elizabeth W; Hunt, Jessica J; Grimsrud, Christopher D; Weiss, Jennifer M

2017-01-01

Hip fracture registries offer an opportunity to identify and to monitor patients with rare conditions and outcomes, including hip fractures in pediatric patients. To report patient demographics and surgical outcomes of pediatric patients treated surgically for hip fractures in a large integrated health care system. Pediatric patients (< 21 years old at the time of fracture) with hip fractures were identified between 2009 and 2012 using our health care system's hip fracture registry. Patient characteristics, type of fracture, surgical treatment, and short-term complications. Among 39 patients identified, 31 (79.5%) were male, and the median age was 15 years old (interquartile range: 11-17 years). Most patients were Hispanic (n = 17, 43.6%) or white (n = 14, 35.9%). There were 8 patients (20.5%) with 15 comorbidities. Delbet Type IV (intertrochanteric) fractures were the most common fracture type (n = 22, 56.4%), and fixation method was equally distributed between intramedullary, screw and sideplate, and screws (n = 12, 30.8% for each). Most surgeries were performed by medium-volume surgeons (n = 22, 56.4%) at medium- and high-volume hospitals (n = 37, 94.9%). Three 90-day readmissions (7.7%), 1 infection (2.6%), 1 malunion (2.6%), and 1 revision (2.6%) were observed in this cohort during the study period. In our series using registry data, hip fractures younger than age 21 years were more common in boys and Hispanic patients. Intertrochanteric fractures (Delbet Type IV) were the most frequently observed type in our community-based hip fracture registry. Short-term complications were infrequent.

A comparative study of the therapeutic effect between long and short intramedullary nails in the treatment of intertrochanteric femur fractures in the elderly.

PubMed

Guo, Xue-Feng; Zhang, Ke-Ming; Fu, Hong-Bo; Cao, Wen; Dong, Qiang

2015-01-01

To compare the clinical effects of long vs. short intramedullary nails in the treatment of intertrochanteric fractures in old patients more than 65 years old. A retrospective analysis of 178 cases of intertrochanteric fractures of the femur (AO type A1 and A2) in the elderly was conducted from January 2008 to December 2013. There were 85 males (47.8%) and 93 females (52.2%) with the age of 65e89 (70.2±10.8) years. The patients were treated by closed reduction and long or short intramedullary nail (Gamma 3) fixation. The length of short nail was 180 mm and that for long nail was 320e360 mm. The general data of patients, operation time, intraoperative blood loss, length of hospital stay, preoperative hemoglobin level, blood transfusion rate, postoperative periprosthetic fractures, infections, complications, etc were carefully recorded. There were 76 cases (42.7%) in the long intramedullary nail group and 102 cases (57.3%) in the short nail group. All the cases were followed up for 12e48 (21.3±6.8) months, during which there were 21 deaths (11.8%), mean (13.8±6.9) months after operation. The intraoperative blood loss was (90.7±50.6) ml in short nail group, greatly less than that in long nail group (127.8±85.9) ml (p=0.004). The short nail group also had a significantly shorter operation time (43.5 min±12.3 min vs. 58.5 min±20.3 min, p=0.002) and lower rate of postoperative transfusion (42.3% vs. 56.7%, p=0.041). But the length of hospital stay showed no big differences. After operation, in each group there was 1 case of periprosthetic fracture with a total incidence of 1.1%, 1.3% in long nail group and 0.9% in short nail group. At the end of the follow-up, all patients achieved bony union. The average healing time of the long nail group was (6.5±3.1) months, and the short nail group was (6.8±3.7) months, revealing no significant differences (p=0.09). Postoperative complications showed no great differences either. Both the intramedullary long and short nail fixation has a good clinical effect in treating intertrochanteric femur fractures in the elderly. They showed no significant difference in terms of therapeutic effect, hospital stay and postoperative complications. The incidence of periprosthetic fractures treated by either length of nails was low. But short intramedullary nailing can obviously decrease the intraoperative blood loss, operation time and postoperative blood transfusion.

Accurate guide wire of lag screw placement in the intertrochanteric fractures: a technical note.

PubMed

Li, Jiang; Wang, Liao; Li, Xiaodong; Feng, Kai; Tang, Jian; Wang, Xiaoqing

2017-09-01

Cephalomedullary fixations are commonly used in the treatment of intertrochanteric fractures. In clinical practice, one of the difficulties is when we exit the guide wire in a wrong position of femoral neck and insert near the hole again, the guide wire often flow into the previous track. This study develops a surgical technique to direct the guide wire to slip away the previous track and slip into a right position. When guide wire is exited to the cortex of femoral, we let the wire in and out at the cortical layer for several times to enlarge the entry hole. After that, electric drill is inverted, rubbed and entered slowly at a right angle. When guide wire encountered new resistance, the electric drill is turned back instantly. This technique can help trauma and orthopedic surgeons to obtain precision placement of the lag screw after the first try is failed.

[Trochanteric femoral fractures: anatomy, biomechanics and choice of implants].

PubMed

Bonnaire, F; Lein, T; Bula, P

2011-06-01

The objective of any surgical care of a trochanteric femoral fracture should be the achievement of a stable osteosynthesis that allows early full weight-bearing mobilisation of the patient, because long-term immobilisation soon becomes a vital threat to the affected patients who are usually elderly with correlating comorbidities. The anatomical references of the proximal femur and the structure of the hip joint contain some specifics that play an essential role in the incurrence of a trochanteric femoral fracture and the planning of the osteosynthesis as well. With reposition and fracture stabilisation particular importance must be attached to the collo-diaphyseal and the antetorsion angle so that they do not interfere with the functional interaction of the hip and knee joint. Uncomplex trochanteric fractures ordinarily stabilise sufficiently after reposition so that even an extramedullary implant can ensure full weight-bearing stability. With evermore distal fracture course and intertrochanteric comminution zone, rotational instability and pivot transfer of the fracture area to lateral and caudal are followed by an increase of the dislocating forces. These kinds of fractures (A2 and A3 according to the AO/ASIF classification) profit from an intramedullary and rotationally stable osteosynthesis. Basically primary total hip arthroplasty is a potential option for surgical care of a trochanteric fracture in elderly patients with relevant coxarthrosis. However this procedure can only be recommended in cases of a stable uncomplex fracture. The more the medial interlocking of the proximal femur is destroyed the more difficult it will be to primarily implant a total hip prosthesis with good offset and without a varus and rotational failure in the fracture zone.The current studies in the main show disadvantages due to increased complications in these patients, so that in cases of an unstable trochanteric fracture a primary osteosynthesis should be performed followed by total hip arthroplasty after fracture consolidation has occurred.

Age-related hip fractures in men: clinical spectrum and short-term outcomes.

PubMed

Poór, G; Atkinson, E J; Lewallen, D G; O'Fallon, W M; Melton, L J

1995-01-01

Clinical spectrum, treatment and short-term outcomes were assessed among the 131 Rochester, Minnesota, men who contracted an initial hip fracture due to moderate trauma during 1978-89. Three-fourths of falls leading to hip fracture occurred indoors with little seasonality, and 91% of fractures were in men 65 years of age or older. The ratio of cervical to intertrochanteric femur fractures was 1.4:1, and there was a tendency toward more neurological conditions among the patients with cervical fractures. Hemiarthroplasty and total hip replacement were mostly performed for cervical fractures, while internal fixation was preferred for intertrochanteric fractures. In-hospital mortality was 11.5%, and the 30-day case fatality rate was 16.0%. Age and postoperative deterioration of mental status significantly increased the risk of early death, the latter even after adjustment in a multivariate model, while comorbidity had a suggestive but not statistically significant influence on mortality. More than half the men were discharged to nursing homes, and 79% of the patients who survived at 1 year resided in nursing homes or intermediate care facilities or were attended by home care. Only 41% of survivors recovered their prefracture level of functioning and nearly 60% of patients limped and required a cane or walker. After implementation of the prospective payment system in 1984, the length of hospital stay was reduced, but there was no change in early mortality rates, in the duration of physical therapy following fracture or in attendance at nursing homes. The results of this population-based study demonstrate the strong impact of hip fractures on short-term outcomes in men.

Medical Research: A Bibliography of Walter Reed Army Medical Center Staff Publications, 1986-1989. Volume 1

DTIC Science & Technology

1990-01-01

Wilson PD Jr: Fracture of the femoral component. Analysis of failure and long-term follow-up of rev-ision. Orthop Chin North Am 1988 Jul;19(3):637-47...DMED,DCI 88224857 Dysart SH, Savory CG, Callaghan JJ: Nonoperative treatment of a postoperative fracture around an uncemented porous-coated femoral...trochanter fractures of the hip without intertrochanteric extension: a case report. Milit Med 1988 Aug;153(8):421-3. DSURG 89015096 Lucente FE, Patow

Effect of zoledronic acid on fracture healing in osteoporotic patients with intertrochanteric fractures.

PubMed

Hayer, Prabhnoor Singh; Deane, Anit Kumar Samuel; Agrawal, Atul; Maheshwari, Rajesh; Juyal, Anil

2017-01-01

To assess the effect of zoledronic acid (ZOL) on fracture healing in osteoporotic patients with intertrochanteric fracture based on radiological evaluation and to study the correlations between severity of osteoporosis, age, gender, and time taken to fracture union. An open label study was conducted on 43 patients at a tertiary care center. The osteoporosis status of all the included patients was documented using a double-energy X-ray absorptiometry scan. A single dose of injection ZOL 5 mg was administered intravenously to all the patients after fixation during their hospital stay. Follow-up of the patients was done at 1, 3, and 6 months after surgery until union was seen radiologically. Data were entered into Microsoft Office Excel version 2007, and interpretation and analysis of obtained data were done using summary statistics. Pearson correlation between age, gender, bone mineral density (BMD), and time taken to fracture union was done using the IBM SPSS Version 22.0 (IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp.). The average age of the patients included in the study was 71.27 ± 11.48 and the average BMD was -4.58±1.42. All the fractures united by the 6 th month of follow-up, which was similar to the union rate in comparison with the literature. The correlations between the gender, BMD, age, and time to union were calculated, and all the r values obtained showed very low correlation and the P values in all the variables were not significant. The bisphosphonate therapy did not adversely affect radiologically determined fracture union, and no correlations between severity of osteoporosis, age, gender, and time taken to fracture union were found to be significant.

Biomechanical Testing of a 3-Hole versus a 4-Hole Sliding Hip Screw in the presence of a Retrograde Intramedullary Nail for Ipsilateral Intertrochanteric and Femur Shaft Fractures.

PubMed

Olsen, Michael; Goshulak, Peter; Crookshank, Meghan C; Moktar, Joel; Brazda, Ignace J; Schemitsch, Emil H; Zdero, Radovan

2018-04-03

The goal of this study was to compare a 3-hole vs. a 4-hole sliding hip screw (SHS) in the presence of a retrograde intramedullary (RIM) nail for fixing intertrochanteric and comminuted midshaft femur fractures. Mechanical tests were performed on 10 matched pairs of human cadaveric femurs that were osteotomized and then fixed using a 3-hole SHS vs. the traditional "gold standard" 4-hole SHS in the presence of a RIM nail. Data showed no differences between the 3-hole SHS with RIM nail vs. 4-hole SHS with RIM nail for stiffness (281 +/- 127 vs. 260 +/- 118 N/mm, p=0.76), clinical failure at 10 mm of hip displacement (2014 +/- 363 vs. 2134 +/- 614 N, p=0.52), or ultimate mechanical failure (3476 +/- 776 vs. 3669 +/- 755 N, p=0.12). For this fracture pattern, a 3-hole SHS with RIM nail may be a suitable surgical alternative to the traditional "gold standard" method, since it provides the same biomechanical properties while potentially reducing surgical time, blood loss, and hardware used. Level III biomechanical study.

[Meta-analysis of internal fixation versus hip replacement in the treatment of trochanteric fractures].

PubMed

Dong, Jian-Bin; Wang, Zhi-Yong; Lu, Hao; Tian, Yuan; Wang, Xin-Rui; Zhang, Zhi-Qiang

2015-03-01

To compare the efficacy of internal fixation (including PFNA and PFN) versus hip replacement (including FHR or THA) in the treatment of trochanteric fractures in adults. Reports of studies using randomized controlled trials (RCT) to compare internal fixationg with hip replacement in the management of intertrochanteric fractures were retrieved (up to January 1, 2013) from the Cochrane Library, PUBMED Data, CNKI (China National Knowledge infrastructure), Elsevier, the Chinese Biomedical Database, Wanfang Data, and manually. Methodological quality of the trials was critically assessed, and relevant data were extracted. Statistical software RevMan 5.0 was used for data-analysis. Seven articles were included in the meta-analysis. The results showed that,compared internal fixation with hip replacement,there were statistical significance in the duration of surgery time [WMD = -2.66, 95% CI (-5.25,-0.06), P = 0.05], intra-operative blood loss [WMD = -24.20, 95% CI (-30.38, -18.02), P < 0.000 01], hospital stays time [WMD = -4.72, 95% CI (-5.18, -4.25), P < 0.000 01], bearing load time [WMD = -29.54, 95% CI (-30.77, -28.31), P < 0.000 01], total complications rate [WMD = 0.15, 95% CI (0.11, 0.22), P < 0.000 01], the good rate of Harris scores [WMD = 1.09, 95% CI (0.54,1.32), P < 0.05]. However, there were no statistical significance in the rate of deep venous thrombosis [WMD = 1.09, 95% CI (0.47, 2.55), P > 0.05]. CON- CLUSION: Hip replacement (containing FHR or THA) for the treatment of intertrochanteric fractures is superior to internal fixa- tion in regards to the duration of surgery time, the mean duration of hosipital stays, mean post-operative down time, intra-opera- tive blood loss, the rate of post-operative good Harris scores. But there is not enough evidence to show any difference between hip replacement (containing THA or FHR) and internal fixation in regards to the rate of deep venous thrombosis. However, internal fixation for the treatment of intertrochanteric fractures is superior to hip replacement (containing FHR or THA) in regards to total complications rate.

[A clinical study on the relationship of the tail femur distance and the lag screw migration or cutting-out after the third generation of Gamma nail fixation of intertrochanteric fracture].

PubMed

Hou, Yu; Yao, Qi; Zhang, Gen'ai; Ding, Lixiang

2018-01-01

To confirm the association between tail femur distance (TFD) and lag screw migration or cutting-out in the treatment of intertrochanteric fracture with the third generation of Gamma nail (TGN). The clinical data of 124 cases of intertrochanteric fracture treated with TGN internal fixation and followed up more than 18 months between January 2012 and December 2015 were reviewed and analyzed. There were 52 males and 72 females, with an age of 46-93 years (mean, 78.5 years). According to AO/Association for the Study of Internal Fixation (AO/ASIF) classification, 43 cases were type 31-A1, 69 cases were type 31-A2, and 12 cases were type 31-A3. The time from injury to operation was 1-10 days (mean, 2.9 days). According to the fracture healing of the patients, the patients were divided into the healing group and failure group. The age, gender, height, bone mineral density (BMD), fracture AO/ASIF classification, the time from injury to operation, and the TFD value at 1 day after operation were recorded and compared. The risk factors for the migration or cutting-out of lag screw were analyzed by logistic regression. There were 111 cases in healing group, the healing time was 80-110 days (mean, 95.5 days). There were 13 cases in failure group, including 2 cases of lag screw cutting-out and 11 cases of significant migration. Except for the TFD value at 1 day after operation in failure group was significantly higher than that in the healing group( t =5.14, P =0.00), there was no significant difference in gender, age, height, BMD, fracture of AO/ASIF classification, and the time from injury to operation ( P >0.05) between 2 groups. logistic regression analysis showed that TFD value was a risk factor for the migration or cutting-out of lag screw (B=1.22, standardized coefficient=0.32, Wald χ 2 =14.66, P =0.00, OR=3.37). The patients with higher TFD value had higher risk of postoperative lag screw migration or cutting-out. This result indicates that the appropriate length of the lag screw is helpful to reduce TFD value and prevent postoperative lag screw migration or cutting-out.

Use of a unipedal standing test to assess the ambulation reacquisition time during the early postoperative stage after hip fracture in elderly Japanese: prospective study.

PubMed

Murata, Koichi; Sugitani, Shigeki; Yoshioka, Hiroki; Noguchi, Takashi; Aoto, Toshiyuki; Nakamura, Takashi

2010-01-01

The aim of this study was to predict the ambulation reacquisition time after hip fracture in elderly people using the unipedal standing test during the early postoperative stage. Patients with an intertrochanteric fracture treated with internal fixation (n = 35) and patients with a femoral neck fracture treated with hemiarthroplasty (n = 22) were included. A unipedal standing test using the nonoperated leg was performed on days 3 and 7 after the operation. Among the patients with an intertrochanteric fracture, those with a positive result on the unipedal standing test on postoperative day (POD) 3 attained gait with parallel guide bars (BG) and walker-assisted gait (WG) significantly earlier than did patients with a negative result on the unipedal standing test. Patients with a positive result on the unipedal standing test on POD 7 attained BG, WG, and cane-assisted gait (CG) significantly earlier than did patients with a negative test. Among patients with a femoral neck fracture, those with a positive unipedal standing test result on POD 3 attained BG, WG, and CG significantly earlier than did patients with a negative test. Those with a positive test result on POD 7 attained BG, WG, and CG significantly earlier than did patients with a negative test. The unipedal standing test given during the early postoperative stage is a good test for predicting the ambulation reacquisition time. Moreover, it gives information that can help determine the need for subacute rehabilitation and about discharge planning and health service provision.

[Early total care pattern for intertrochanteric fracture of femur in the elderly].

PubMed

Gu, Jie; Kang, Xin-yong; Xu, Hong-wei; Li, Yong-fu; Zahng, Bin; Guo, Jian; He, Zhen-nian

2016-06-01

To evaluate clinical results of early total care (ETC) treatment for elderly patients with intertrochanteric femur fractures. Clinical data of 106 elderly patients with intertrochanteric fracture treated from January 2012 and February 2015 were retrospectively studied. According to whether receiving the early total care mode, the patients were divided into 2 groups, 34 cases were diagnosed and treated with early total care pattern (ETC group), including 14 males and 20 females with an average age of (74.88 ± 4.38) years old ranging from 70 to 86. According to Evans types, 4 cases were type I, 5 cases were type II, 13 cases were type III, 11 cases were type IV, 1 case was type V. Seventy-two patients were treated with conventional trauma method (conventional group), including 35 males and 37 females with an average age of (74.46 ± 3.63) years old ranging from 70 to 85. According to Evans type, 8 cases were type I ,13 cases were type II, 25 cases were type III, 25 cases were type IV, and 1 case was type V. All fractures were treated with proximal femoral nails anti-rotation (PFNA). Operative time, hospital stays, leaving bed time, complications, cases of death at 1 year after operation, postoperative Harris score at 12 months were observed and compared. All patients were followed up, the time of ETC group ranged from 9 to 18 months with an average of 13.29 ± 1.51, and the time in conventional group ranged from 12 to 16 months with an average 12.93 ± 1.15, while there was no significant difference between two groups in time of following-up (t = 1.368, P = 0.174). There was no significant meaning in cases of death between ETC group (2 cases) and conventional group (8 cases). Three cases occurred complications in ETC group, and 20 cases in conventional group,there was obvious meaning between two groups (χ² = 0.739, P = 0.318). Operative time,hospital stays,leaving bed time in ETC group respectively was (2.03 ± 0.67) d, (15.41 ± 2.87) d and (3.62 ± 0.74) d; while in conventional group respectively was (4.17 ± 1.59) d, (20.11 ± 4.24) d and (5.35 ± 1.22) d; there were significant differences between two groups in operative time, hospital stays, leaving bed time. Postoperative Harris scores at 12 months in ETC group was (82.32 ± 4.56), and (79.24 ± 5.52) in conventional group, there was obvious meaning between two groups (t = 2.833, P = 0.006). ETC pattern is a novel method for diagnosis and treatment of intertrochanteric femur fractures in elderly, it could shorten operative time, hospital stays, leaving bed time, decrease complications and promote recovery of function.

[Clinical analysis of LPFP, PFNA and BPH in treating femoral intertrochanteric fractures in elderly patients].

PubMed

Zhu, Li-Jun; Li, Xiao-Fei; Liu, Chao; Lyu, Cheng-Yu

2017-07-25

To evaluate the clinical results of locking proximal femur plate(LPFP), proximal femoral nail antirotation(PFNA) and bipolar hemiarthroplasty(BPH) in the treatment of femoral intertrochanteric fractures in elderly patients. Retrospective analysis of the 86 elderly patients with femoral intertrochanteric fractures during June 2011 and August 2016 were enrolled in this study. The patients were divided into 3 groups: 26 cases in LPFP group included 10 males and 16 females with an average age of (72.54±4.78) years old, 5 cases of type II of Evans, 12 cases of type III and 9 cases of type IV; 39 cases in PFNA group included 17 males and 22 females with an average age of 74.41±5.65, 11 cases of type II, 18 cases of type III and 10 cases of type IV; 21 cases in BPH group included 9 males and 12 females with an average age of 76.23±6.97, 1 case of type II, 10 cases of type III and 10 cases of type IV. The data of three groups were collected for statistical analysis on the following aspects: operation time, intraoperative blood loss, the length of hospital stay, postoperative complications and Harris score of the hip joint function. The wound healed well and no complication occurred. Eighty-four cases were follow-up, while 2 cases were lost, the follow-up rate was 97.6%. The patients were followed up for 22 to 41 months with an average of 26.3 months. For comparison of operation time and time of the hospital stay, BPH group was shorter than the LPFP and PFNA group( F =19.782, 21.981, P <0.05). For comparison of the intraoperative blood loss, the BPH group was less blood loss than the LPFP and PFNA group( F =12.976, P <0.05), while there was no significant means between the LPFP and PFNA group( t =10.879, P >0.05). For comparison of the postoperative complications, LPFP group was higher than BHP and PFNA group( F =30.976, P <0.05), while there was no significant means between LPFP and PFNA group( t =9.902, P >0.05). For comparison of the Harris score of the hip joint at 1 year after operation, BPH and PFNA group were both higher than LPFP group( F =19.692, P <0.05), while there was no significant means between BPH and PFNA group ( t =4.971, P >0.05). For elder patient with femoral intertrochanteric fracture, BPH could be the best optional for the shorter operation time and less complications. And the PFNA also could be optional choice for the patients while the LPFP was forbidden for the elder patients.

Active shape modeling of the hip in the prediction of incident hip fracture.

PubMed

Baker-LePain, Julie C; Luker, Kali R; Lynch, John A; Parimi, Neeta; Nevitt, Michael C; Lane, Nancy E

2011-03-01

The objective of this study was to evaluate right proximal femur shape as a risk factor for incident hip fracture using active shape modeling (ASM). A nested case-control study of white women 65 years of age and older enrolled in the Study of Osteoporotic Fractures (SOF) was performed. Subjects (n = 168) were randomly selected from study participants who experienced hip fracture during the follow-up period (mean 8.3 years). Controls (n = 231) had no fracture during follow-up. Subjects with baseline radiographic hip osteoarthritis were excluded. ASM of digitized right hip radiographs generated 10 independent modes of variation in proximal femur shape that together accounted for 95% of the variance in proximal femur shape. The association of ASM modes with incident hip fracture was analyzed by logistic regression. Together, the 10 ASM modes demonstrated good discrimination of incident hip fracture. In models controlling for age and body mass index (BMI), the area under receiver operating characteristic (AUROC) curve for hip shape was 0.813, 95% confidence interval (CI) 0.771-0.854 compared with models containing femoral neck bone mineral density (AUROC = 0.675, 95% CI 0.620-0.730), intertrochanteric bone mineral density (AUROC = 0.645, 95% CI 0.589-0.701), femoral neck length (AUROC = 0.631, 95% CI 0.573-0.690), or femoral neck width (AUROC = 0.633, 95% CI 0.574-0.691). The accuracy of fracture discrimination was improved by combining ASM modes with femoral neck bone mineral density (AUROC = 0.835, 95% CI 0.795-0.875) or with intertrochanteric bone mineral density (AUROC = 0.834, 95% CI 0.794-0.875). Hips with positive standard deviations of ASM mode 4 had the highest risk of incident hip fracture (odds ratio = 2.48, 95% CI 1.68-3.31, p < .001). We conclude that variations in the relative size of the femoral head and neck are important determinants of incident hip fracture. The addition of hip shape to fracture-prediction tools may improve the risk assessment for osteoporotic hip fractures. Copyright © 2011 American Society for Bone and Mineral Research.

Learning Curve and Clinical Outcomes of Performing Surgery with the InterTan Intramedullary Nail in Treating Femoral Intertrochanteric Fractures

PubMed Central

2017-01-01

Purpose. The purpose of this study is to evaluate the learning curve of performing surgery with the InterTan intramedullary nail in treating femoral intertrochanteric fractures, to provide valuable information and experience for surgeons who decide to learn a new procedure. Methods. We retrospectively analyzed data from 53 patients who underwent surgery using an InterTan intramedullary nail at our hospital between July 2012 and September 2015. The negative exponential curve-fit regression analysis was used to evaluate the learning curve. According to 90% learning milestone, patients were divided into two group, and the outcomes were compared. Results. The mean operative time was 69.28 (95% CI 64.57 to 74.00) minutes; with the accumulation of surgical experience, the operation time was gradually decreased. 90% of the potential improvement was expected after 18 cases. In terms of operative time, intraoperative blood loss, hospital stay, and Harris hip score significant differences were found between two groups (p = 0.009, p = 0.000, p = 0.030, and p = 0.002, resp.). Partial weight bearing time, fracture union time, tip apex distance, and the number of blood transfusions and complications were similar between two groups (p > 0.5). Conclusion. This study demonstrated that the learning curve of performing surgery with the InterTan intramedullary nail is acceptable and 90% of the expert's proficiency level is achieved at around 18 cases. PMID:28503572

Modified Pauwels' intertrochanteric osteotomy in neglected femoral neck fractures in children: a report of 10 cases followed for a minimum of 5 years.

PubMed

Magu, Narender Kumar; Singh, Roop; Sharma, Ashwini Kumar; Ummat, Vikas

2007-04-01

To evaluate the role of a modified Pauwels' intertrochanteric osteotomy (MPIO) in neglected femoral neck fractures in children. Prospective study with retrospective analysis. Tertiary care Postgraduate Institute of Medical Sciences. Ten children (8 males, 2 females) with an average age of 10.2 years with neglected femoral neck fractures were seen from 1990 to 1998. A femoral neck fracture was considered neglected when no proper medical treatment was instituted for at least 1 month following the fracture. Nonunion was accompanied by coxa vara and resorption of the femoral neck in 9 patients; a 10th patient had a neglected femoral neck fracture for 1 month without coxa vara. Three patients at time of presentation with Delbet Type II displaced fractures with associated nonunion and coxa vara (2 with Ratliff Type III and 1 with Type I) also had avascular necrosis using plain radiographic criteria of increased density. Modified Pauwels' intertrochanteric osteotomy. The children were immobilized in a hip spica for 6-10 weeks postoperatively and weightbearing was started after hip spica removal. Fracture healing, neck-shaft angle, avascular necrosis, and functional outcome. Patients were followed for an average of 8.2 years (range 5-12 years). All patients had union of their fracture within an average of 16.6 weeks (12-20 weeks) and of the osteotomy site within 8.2 weeks (7-9 weeks). Radiologic signs of avascular necrosis disappeared completely in the 3 patients who presented with avascular necrosis. In 1 patient with a preoperatively viable femoral head, radiologic signs of Ratliff Type I avascular necrosis appeared between 60 and 98 weeks. This radiologic finding became normal again, indicating viability of the femoral head somewhere between 98 to 205 weeks of follow-up. Postoperatively, an average of 135-degree neck-shaft angle was achieved (range 125-160 degrees). The average preoperative neck-shaft angle was 104.4 degrees (range 92-120 degrees) and on the normal hip side it was 127.7 degrees (range 124-132 degrees). Significant improvement in the neck-shaft angle was seen compared with the preoperative angle (P < 0.001) and normal hip angle (P < 0.05). Coxa vara and signs of chondrolysis were not observed in any of the patients. Premature proximal femoral epiphyseal closure resulting in a 1-cm and a 1.5-cm leg-length discrepancy was seen in 2 patients as compared with their normal side. A mild Trendelenburg gait was observed in 1 patient (10%). Using Ratliff's criteria, 9 patients (90%) were graded as a good result and 1 patient (10%) was graded as a fair result. The osteotomy plate was removed in 1 patient (10%). An MPIO creates a biomechanical environment conducive to healing of a neglected femoral neck nonunion in a child while simultaneously correcting an associated coxa vara. The procedure also seems to have a biological role in helping restore viability to a noncollapsed femoral head with avascular necrosis.

Risk factors for distal radius fracture in postmenopausal women.

PubMed

Xu, Wenting; Ni, Cheng; Yu, Ren; Gu, Guoqing; Wang, Zheren; Zheng, Guoqing

2017-05-01

The aim of this work was to explore the risk factors for distal radius fracture in postmenopausal women. A total of 611 postmenopausal women with distal radius fractures were included. In all, 173 patients with unstable distal radius fractures were included (unstable fracture group), while there were 438 patients with stable distal radius fractures (stable fracture group). The control group comprised 800 postmenopausal women with no fracture. A questionnaire survey was conducted. Compared with the control group, the 611 postmenopausal women with distal radius fractures had a higher body mass index (BMI). Advanced age and higher BMI were more common in the unstable fracture group than in the stable fracture group (P <0.05). A higher proportion of the 611 postmenopausal women with a distal radius fracture had fallen in the last 12 months than in the control group. Comorbidities and the frequency of falls in the last 12 months were higher in the unstable fracture group than in the stable fracture group (P < 0.05). A higher proportion of the control group was taking calcium supplements, while the proportion taking calcium supplementation in the unstable fracture group was lower than that in the stable fracture group (P < 0.05). Osteoporosis in the two fracture groups (P < 0.05) was significantly higher than in the control group and was the highest in the unstable fracture group (P < 0.05). In postmenopausal women, obesity, falls, unknown osteoporosis status, and osteoporosis are associated with high risk of distal radius fracture. If comorbidities and advanced age are also present, this group of persons may be at higher risk for unstable distal radius fractures.

A refined definition improves the measurement reliability of the tip-apex distance.

PubMed

Sakagoshi, Daigo; Sawaguchi, Takeshi; Shima, Yosuke; Inoue, Daisuke; Oshima, Takeshi; Goldhahn, Sabine

2016-07-01

Tip-apex distance (TAD) is reported as a good predictor for cut-outs of lag screws and spiral blades in the treatment of intertrochanteric fractures, and surgeons are advised to strive for TAD within 20 mm. However, the femoral neck axis and the position of the lower limb in the lateral radiograph are not clearly defined and can lead to measurement errors. We propose a refined TAD by defining these factors. The objective of this study was to analyze the reliability of this refined TAD. The radiographs of 130 prospective cases with unstable trochanteric fractures were used for the analysis of the refined TAD. The refined TAD was independently measured by 2 raters with clinical experience of more than 10 years (rater 1, 2) and 2 raters with much less clinical experience (rater 3, 4) after they received a training about the new measurement method. Intraclass correlation coefficient (ICC [2,4]) was calculated to assess the interrater reliability. The mean refined TADs were 18.2:18.4:18.2:18.2 mm for rater 1:2:3:4. There was a strong correlation among all four raters (ICC 0.998, (95% CI: 0.998, 0.999). Regardless of the clinical experience of raters, the refined TAD is a reliable tool and can be used to develop new TAD recommendations for predicting failure of fixation. Future studies with larger samples are needed to evaluate the predictive value of the refined TAD. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Head salvage of an infected neck of femur fracture in an adult: a case report.

PubMed

Joseph, Christina Marie; Jepegnanam, Thilak Samuel

2018-05-23

Head preservation of an infected neck of femur fracture appears to be extremely rare with no described cases in literature till date. We present the outcome of head salvage in a young adult with an infected neck of femur nonunion who in addition had chronic osteomyelitic sequelae of his entire femur with reactivation of latent infection in the distal femoral diaphysis. Osteosynthesis was performed by means of cancellous screw fixation augmented with bone substitute following a failed attempt at salvage with a valgus intertrochanteric osteotomy. The patient had an excellent functional outcome with near normal hip range of movements at a follow-up of 5 years after union.

Outcomes of osteoporotic trochanteric fractures treated with cement-augmented dynamic hip screw

PubMed Central

Gupta, Rakesh Kumar; Gupta, Vinay; Gupta, Navdeep

2012-01-01

Background: Dynamic hip screw (DHS) has been the standard treatment for stable trochanteric fracture patterns, but complications of lag screw cut out from a superior aspect, due to inadequate bone anchorage, occur frequently in elderly osteoporotic patients. Polymethylmethacrylate (PMMA) has been used as an augmentation tool to facilitate fixation stability in cadaveric femora for biomechanical studies and in pathological fractures. However, there are very few reports on the utilization of PMMA cement to prevent these complications in fresh intertrochanteric fractures. A prospective study was conducted to evaluate the outcome and efficacy of PMMA augmented DHS in elderly osteoporotic patients with intertrochanteric fractures. Materials and Methods: The study included 64 patients (AO type31-A2.1 in eight, A2.2 in 29, A2.3 in 17 patients, and 31-A3.1 in five, A3.2 in three, and A3.3 in two patients) with an average age of 72 years (60 – 94 years) of which 60 were available for final followup. PMMA augmentation of DHS was performed in all cases by injecting PMMA cement into the femoral head with a custommade gun designed by the authors. The clinical outcome was rated as per the Salvati and Wilson scoring system at the time of final followup of one year. Results were graded as excellent (score > 31), good (score 24 – 31), fair (score 16 – 23), and poor (score < 16). Results: Fracture united in all patients and the average time to union was 13.8 weeks (range 12 – 16 weeks). At an average followup of 18 months (range 12 – 24 months), no incidence of varus collapse or superior screw cut out was observed in any of the patients in spite of weightbearing ambulation from the early postoperative period. There was no incidence of avascular necrosis (AVN) or cement penetration into the joint in our series. Most of the patients were able to regain their prefracture mobility status with a mean hip pain score of 8.6. Conclusion: Cement augmentation of DHS appears to be an effective method of preventing osteoporosis related complications of fracture fixation in the trochanteric fractures. The technique used for cement augmentation in the present study is less likely to cause possible complications of cement augmentation like thermal necrosis, cement penetration into the joint, and AVN hip. PMID:23325965

CORRELATION BETWEEN TIME UNTIL SURGICAL TREATMENT AND MORTALITY AMONG ELDERLY PATIENTS WITH FRACTURES AT THE PROXIMAL END OF THE FEMUR.

PubMed

Arliani, Gustavo Gonçalves; da Costa Astur, Diego; Linhares, Glauber Kazuo; Balbachevsky, Daniel; Fernandes, Hélio Jorge Alvachian; Dos Reis, Fernando Baldy

2011-01-01

The primary aim of this study was to analyze the possible association between delay in receiving surgical treatment and mortality among elderly patients with fractures at the proximal end of the femur. 269 patients with fractures at the proximal end of the femur (femur neck and intertrochanteric fractures) who were treated surgically at Hospital São Paulo, UNIFESP, São Paulo, between January 2003 and December 2007, were studied. The following attributes were analyzed and compared with the literature relating to this subject: sex, age, type of fracture, classification of the fracture, affected side, synthesis used, trauma mechanism, length of hospitalization, waiting time for surgery, associated comorbidities, hemogram on admission, type of anesthesia, need for blood transfusion, day of the week and season of the year of the fracture. The study showed that higher mortality correlated with higher numbers of clinical comorbidities, longer hospitalization and use of general anesthesia during the surgery. There was no association between the time spent waiting for surgery and mortality.

Sliding hip screw versus sliding helical blade for intertrochanteric fractures: a propensity score-matched case control study.

PubMed

Fang, C; Lau, T W; Wong, T M; Lee, H L; Leung, F

2015-03-01

The spiral blade modification of the Dynamic Hip Screw (DHS) was designed for superior biomechanical fixation in the osteoporotic femoral head. Our objective was to compare clinical outcomes and in particular the incidence of loss of fixation. In a series of 197 consecutive patients over the age of 50 years treated with DHS-blades (blades) and 242 patients treated with conventional DHS (screw) for AO/OTA 31.A1 or A2 intertrochanteric fractures were identified from a prospectively compiled database in a level 1 trauma centre. Using propensity score matching, two groups comprising 177 matched patients were compiled and radiological and clinical outcomes compared. In each group there were 66 males and 111 females. Mean age was 83.6 (54 to 100) for the conventional DHS group and 83.8 (52 to 101) for the blade group. Loss of fixation occurred in two blades and 13 DHSs. None of the blades had observable migration while nine DHSs had gross migration within the femoral head before the fracture healed. There were two versus four implant cut-outs respectively and one side plate pull-out in the DHS group. There was no significant difference in mortality and eventual walking ability between the groups. Multiple logistic regression suggested that poor reduction (odds ratio (OR) 11.49, 95% confidence intervals (CI) 1.45 to 90.9, p = 0.021) and fixation by DHS (OR 15.85, 95%CI 2.50 to 100.3, p = 0.003) were independent predictors of loss of fixation. The spiral blade design may decrease the risk of implant migration in the femoral head but does not reduce the incidence of cut-out and reoperation. Reduction of the fracture is of paramount importance since poor reduction was an independent predictor for loss of fixation regardless of the implant being used. Cite this article: Bone Joint J 2015;97-B:398-404. ©2015 The British Editorial Society of Bone & Joint Surgery.

Results of operative fixation of unstable ankle fractures in geriatric patients.

PubMed

Pagliaro, A J; Michelson, J D; Mizel, M S

2001-05-01

It is widely accepted that operative fixation of unstable ankle fractures yields predictably good outcomes in the general population. The current literature, however reports less acceptable results in the geriatric population age 65 years and older. The current study analyzes the outcome of the surgical treatment of unstable ankle fractures in patients at least 65 years old. Twenty three patient over 65 years old were surgically treated after sustaining 21 (91%) closed and 2 (9%) open grade II unstable ankle fractures. Fractures were classified according to the Danis-Weber and Lauge-Hansen schemes. Fracture type was predominantly Weber B (21/23, 91%), or supination external rotation stage IV (21/23, 91%). Fracture union rate was 100%. There were three significant complications including a lateral wound dehiscence with delayed fibular union in an open fracture dislocation, and two below knee amputations, neither of which was directly related to the fracture treatment. There were three minor complications; one superficial wound infection and two cases of prolonged incision drainage, all of which resolved without further surgical intervention. Complications were associated with open fractures and preexisting systemic disease. These results indicate that open reduction and internal fixation of unstable ankle fractures in geriatric patients is an efficacious treatment regime that with results that are comparable to the general population.

Functional Improvement in Geriatric Hip Fractures: Does Vitamin D Deficiency Affect the Functional Outcome of Patients With Surgically Treated Intertrochanteric Hip Fractures.

PubMed

Seng, W R D; Belani, M H; Ramason, R; Naidu, G; Doshi, H K

2015-09-01

The "Integrated Care Pathway" for geriatric intertrochanteric (IT) fractures in Singapore's Tan Tock Seng Hospital has shown significant functional recovery in patients' activities of daily living. However, the influence of preoperative vitamin D on functional recovery remains equivocal. This retrospective study therefore aims to determine whether patients with preoperative vitamin D deficiency have poorer functional outcomes. A total of 171 patients who had surgical treatment for IT fractures were recruited in the study. They were categorized into group A (vitamin D deficient) and group B (normal vitamin D). Charlson Comorbidity Index (CCI) score and nutritional parameters including hemoglobin, albumin, and adjusted calcium levels on admission were recorded. The Modified Barthel Index (MBI) score was used to measure functional recovery at the following time intervals: at pre-fall, at discharge after surgery, at 6 months, and at 1-year follow-up. The mean age of both the groups (A: 79.7 years, n = 45; B: 83.0 years, n = 126) was statistically different (P < .05). However, the mean CCI (A: 9.42 and B: 10.13), hemoglobin (A: 12.4 and B 11.1), adjusted calcium (A: 2.39 and B: 2.38), and mean albumin (A: 33.6 and B: 33.0) of the groups were not significantly different. Furthermore, the MBI scores were not significantly different for both groups at preinjury (A: 91.5 and B: 89.4), at discharge (A: 55.2 and B: 58.9), at 6 months (A: 70.9 and B: 75.1), and at 1 year (A: 75.8 and B: 79.4). In our cohort, patients with vitamin D deficiency were younger. However, vitamin D deficiency at time of injury had no significant influence on functional recovery in patients with surgically treated hip fracture in our Integrated Care Pathway. In addition, patients who had a normal vitamin D levels had similar functional scores and improvement postoperatively and at 1 year (A: 82.8% and B: 88.9%).

Assessment of Hip Fracture Risk Using Cross-Section Strain Energy Determined by QCT-Based Finite Element Modeling

PubMed Central

Kheirollahi, Hossein

2015-01-01

Accurate assessment of hip fracture risk is very important to prevent hip fracture and to monitor the effect of a treatment. A subject-specific QCT-based finite element model was constructed to assess hip fracture risk at the critical locations of femur during the single-leg stance and the sideways fall. The aim of this study was to improve the prediction of hip fracture risk by introducing a novel failure criterion to more accurately describe bone failure mechanism. Hip fracture risk index was defined using cross-section strain energy, which is able to integrate information of stresses, strains, and material properties affecting bone failure. It was found that the femoral neck and the intertrochanteric region have higher fracture risk than other parts of the femur, probably owing to the larger content of cancellous bone in these regions. The study results also suggested that women are more prone to hip fracture than men. The findings in this study have a good agreement with those clinical observations reported in the literature. The proposed hip fracture risk index based on strain energy has the potential of more accurate assessment of hip fracture risk. However, experimental validation should be conducted before its clinical applications. PMID:26601105

A randomised comparison of AMBI, TGN and PFN for treatment of unstable trochanteric fractures.

PubMed

Papasimos, S; Koutsojannis, C M; Panagopoulos, A; Megas, P; Lambiris, E

2005-09-01

In this study, we initiated a prospective, randomised, clinical trial comparing the AMBI, TGN and PFN operations used for treatment of unstable fractures, for differences in intra-operative use, consolidation, complications and functional outcome. We have compared the pre-, intra- and post-operating variables of AMBI, TGN and PFN operations that were used for treatment of unstable trochanteric fractures, of 120 patients all above 60 years old diagnosed with extracapsular hip fractures classified as AO Type 31-A2 or Type 31-A3. According to our results the three methods are comparable in the treatment of unstable trochanteric fractures of patients above 60 years old. The AMBI remains the gold standard for the fractures of trochanteric region. TGN has an easier and faster procedure, facilitates early weight bearing and had minor late complications. An improper use of the PFN system was the reason for the most complications and the longer operation time of the device. PFN is also an accepted minimally invasive implant for unstable proximal femoral fractures but future modification of the implant to avoid Z-effect phenomenon, careful surgical technique and selection of the patients should reduce its high complication rate.

Preoperative Radiographic and CT Findings Predicting Syndesmotic Injuries in Supination-External Rotation-Type Ankle Fractures.

PubMed

Choi, Young; Kwon, Soon-Sun; Chung, Chin Youb; Park, Moon Seok; Lee, Seung Yeol; Lee, Kyoung Min

2014-07-16

The Lauge-Hansen classification system does not provide sufficient data related to syndesmotic injuries in supination-external rotation (SER)-type ankle fractures. The aim of the present study was to investigate factors helpful for the preoperative detection of syndesmotic injuries in SER-type ankle fractures using radiographs and computed tomography (CT). A cohort of 191 consecutive patients (104 male and eighty-seven female patients with a mean age [and standard deviation] of 50.7 ± 16.4 years) with SER-type ankle fractures who had undergone operative treatment were included. Preoperative ankle radiographs and CT imaging scans were made for all patients, and clinical data, including age, sex, and mechanism of injury (high or low-energy trauma), were collected. Patients were divided into two groups: the stable syndesmotic group and the unstable syndesmotic group, with a positive intraoperative lateral stress test leading to syndesmotic screw fixation. Fracture height, fracture length, medial joint space, extent of fracture, and bone attenuation were measured on radiographs and CT images and were compared between the groups. Binary logistic regression analysis was performed to identify the factors that significantly contributed to unstable syndesmotic injuries. Receiver operating characteristic curves were calculated, and cutoff values were suggested to predict unstable syndesmotic injuries on preoperative imaging measurements. Of the 191 patents with a SER-type ankle fracture, thirty-eight (19.9%) had a concurrent unstable syndesmotic injury. Age, sex, mechanism of injury, fracture height, medial joint space, and bone attenuation were significantly different between the two groups. In the binary logistic analysis, fracture height, medial joint space, and bone attenuation were found to be significant factors contributing to unstable syndesmotic injuries. The cutoff values for predicting unstable syndesmotic injuries were a fracture height of >3 mm and a medial joint space of >4.9 mm on CT scans, and a fracture height of >7 mm and medial joint space of >4.5 mm on radiographs. Fracture height, medial joint space, and bone attenuation were useful factors for the preoperative detection of unstable syndesmotic injuries in SER-type ankle fractures. Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Fixation of unstable type II clavicle fractures with distal clavicle plate and suture button.

PubMed

Johnston, Peter S; Sears, Benjamin W; Lazarus, Mark R; Frieman, Barbara G

2014-11-01

This article reports on a technique to treat unstable type II distal clavicle fractures using fracture-specific plates and coracoclavicular augmentation with a suture button. Six patients with clinically unstable type II distal clavicle fractures underwent treatment using the above technique. All fractures demonstrated radiographic union at 9.6 (8.4-11.6) weeks with a mean follow-up of 15.6 (12.4-22.3) months. American Shoulder and Elbow Surgeons, Penn Shoulder Score, and Single Assessment Numeric Evaluation scores were 97.97 (98.33-100), 96.4 (91-99), and 95 (90-100), respectively. One patient required implant removal. Fracture-specific plating with suture-button augmentation for type II distal clavicle fractures provides reliable rates of union without absolute requirement for implant removal.

Atlas Fractures and Atlas Osteosynthesis: A Comprehensive Narrative Review.

PubMed

Kandziora, Frank; Chapman, Jens R; Vaccaro, Alexander R; Schroeder, Gregory D; Scholz, Matti

2017-09-01

Most atlas fractures are the result of compression forces. They are often combined with fractures of the axis and especially with the odontoid process. Multiple classification systems for atlas fractures have been described. For an adequate diagnosis, a computed tomography is mandatory. To distinguish between stable and unstable atlas injury, it is necessary to evaluate the integrity of the transverse atlantal ligament (TAL) by magnetic resonance imaging and to classify the TAL lesion. Studies comparing conservative and operative management of unstable atlas fractures are unfortunately not available in the literature; neither are studies comparing different operative treatment strategies. Hence all treatment recommendations are based on low level evidence. Most of atlas fractures are stable and will be successfully managed by immobilization in a soft/hard collar. Unstable atlas fractures may be treated conservatively by halo-fixation, but nowadays more and more surgeons prefer surgery because of the potential discomfort and complications of halo-traction. Atlas fractures with a midsubstance ligamentous disruption of TAL or severe bony ligamentous avulsion can be treated by a C1/2 fusion. Unstable atlas fractures with moderate bony ligamentous avulsion may be treated by atlas osteosynthesis. Although the evidence for the different treatment strategies of atlas fractures is low, atlas osteosynthesis has the potential to change treatment philosophies. The reasons for this are described in this review.

Hip fractures in a developing country: osteoporosis frequency, predisposing factors and treatment costs.

PubMed

Tanriover, Mine Durusu; Oz, S Gul; Tanriover, Altug; Kilicarslan, Alpaslan; Turkmen, Ercan; Guven, Gulay Sain; Saracbasi, Osman; Tokgozoglu, Mazhar; Sozen, Tumay

2010-01-01

Hip fractures are a burden to both society and the individual. The aim of this study was to describe the frequency of osteoporosis and the in-hospital treatment costs of patients with hip fractures admitted to Hacettepe University Faculty of Medicine Hospital. Patients with a hip fracture who were admitted to the Orthopedics and Traumatology wards between April 2003 and December 2006 were interviewed and 50 of them were enrolled prospectively in the study protocol. Patient characteristics, predisposing factors for fractures and hospital costs were recorded as well as laboratory test results and bone mineral density measurements. The mean age was 74.2 years and 72% of the patients were women. Sixty-four percent of them presented with an intertrochanteric fracture. The patient population was significantly debilitated with a high prevalence of vitamin D insufficiency and secondary hyperparathyroidism. No association was shown with T scores and dietary habits and lifestyle characteristics of patients. In 34% of patients in whom measurements were available, no osteoporosis could be documented. The mean hospital expenditure was $5983. Factors affecting the total cost were age and functional status of the patient and the duration of hospital stay, independent of the type of fracture and surgical procedure used. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

Intramedullary nailing: experience in 427 patients.

PubMed

Lambiris, E; Tyllianakis, M; Megas, P; Panagiotopoulos, E

1996-01-01

In the Orthopaedic Department in Patras University 427 intramedullary nailings in the lower limbs were performed between 1989 and 1994 and retrospectively reviewed to evaluate the range of complications. One hundred and seventy-two were nailings of the femur; 80 gamma nails mainly for subtrochanteric and intertrochanteric with subtrochanteric extension fractures were included, (total 252/59%); 175 (41%) were nailings of the tibia. Union was achieved in all case. Overall the complication rate in this series was 3.3% (14 cases) and included infection (4 cases), neuropraxia (2 cases), implant failure (5 cases), limb length deficiency (2 cases) and malrotation (1 case).

[Damage Control Surgery in Polytrauma Patients with Pelvic Fractures. Is It Possible to Use Internal Fixation?

PubMed

Havlůj, L; Džupa, V; Gürlich, R

2017-01-01

Current polytrauma management is multidisciplinary, with Damage Control Surgery (DCS), Damage Control Orthopaedics (DCO) and Damage Control Resuscitation (DCR) being applied in the first few hours after injury. The most severe group of polytrauma patients are those with circulatory instability and massive blood loss as a consequence of unstable pelvic fractures. In treating these patients, of crucial importance is the speed and quality of stabilisation of pelvic fracture fragments. The authors present two case reports of polytrauma patients with unstable pelvic fractures, in whom open reduction and internal fixation was performed on the anterior fracture segment through extended laparotomy in order to stop bleeding into the abdominopelvic cavity as part of the DCS approach. Key words: exsanguination, polytrauma, unstable pelvic fracture, plate fixation.

[Comparative study of proximal femoral shortening after the third generation of Gamma nail versus proximal femoral nail anti-rotation in treatment of intertrochanteric fracture].

PubMed

Hou, Yu; Yao, Qi; Zhang, Gen'ai; Ding, Lixiang

2018-03-01

To explore the difference of the proximal femoral shortening (PFS) between the third generation of Gamma nail (TGN) and the proximal femoral nail anti-rotation (PFNA) in treating intertrochanteric fracture of femur. The clinical data of 158 patients with intertrochanteric fracture of femur who were treated with TGN internal fixation or PFNA internal fixation between January 2014 and December 2015 were retrospectively analysed. The patients were divided into TGN group (69 cases) and PFNA group (89 cases) according to surgical operation. There was no significant difference in gender, age, bone mineral density, causes of injury, AO/Association for the Study of Internal Fixation (AO/ASIF) classification, accompanied disease, and the time from injury to operation between 2 groups ( P >0.05). The result of fracture reduction was divided into 3 types: positive medial cortex support, neutral position cortex support, and negative medial cortex support according to the method of Chang et al . At 18 months postoperatively, bilateral hip anteroposterior X-ray films were taken to measure horizontal PFS values (marked as X), vertical PFS values (marked as Y), and calculate the total PFS values (marked as Z). The PFS values were divided into 4 grades according to the criteria (≤1.0 mm, 1.0-4.9 mm, 5.0-9.9 mm, and ≥10.0 mm), and the constituent ratio was calculated and compared between 2 groups. The X, Y, and Z values and the collodiaphyseal angles of 2 groups at 18 months postoperatively were compared. The X, Y, and Z values of 2 groups of patients with failed fixation and normal healing within 18 months after operation were recorded and compared. The X, Y, and Z values of 2 groups of the patients with different cortex support types were also compared. There were 34 cases of positive medial cortex support, 30 cases of neutral position cortex support, and 5 cases of negative medial cortex support in TGN group, and there were 45, 33, and 11 cases in PFNA group respectively, showing no significant difference between 2 groups ( Z =-1.06, P =0.29). All patients were followed up 18 months after operation. At 18 months after operation, the constituent ratios of PFS values (X, Y, Z) had significant differences between 2 groups ( P <0.05). The patients of shortening of 1.0-4.9 mm and 5.0-9.9 mm were obviously more in TGN group than in PFNA group; the patients of shortening of ≥10.0 mm were obviously more in PFNA group than in TGN group. There were significant differences in X, Y, and Z values between 2 groups ( P <0.05), but no significant difference of the collodiaphysial angle was found between 2 groups ( t =0.47, P =0.64). Six cases of internal fixation failed in TGN group and PFNA group respectively within 3 months after operation, and there was no significant difference of X, Y, and Z values between failed fixation and normal healing patients within 2 groups ( P >0.05). When the reposition effect was the positive medial cortex support, the X, Y, and Z values were significantly lower in TGN group than in PFNA group ( P <0.05); but no significant difference was found between 2 groups when the reposition effect was the neutral position cortex support or negative medial cortex support ( P >0.05). At 18 months after operation, the X, Y, and Z values of the negative medial cortex support patients were significantly higher than those of the positive medial cortex support or the neutral position cortex support patients within 2 groups ( P <0.05). PFS is a common complication of the intertrochanteric fracture of the femur after internal fixation. During operation, the selection of internal fixation should be based on the results of intraoperative reduction. TGN should be applied to reduce PFS if positive medial cortex support happened.

Relevant signs of stable and unstable thoracolumbar vertebral column trauma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gehweiler, J.A.; Daffner, R.H.; Osborne, R.L.

1981-12-01

One-hundred and seventeen patients with acute thoracolumbar vertebral column fracture or fracture-dislocations were analyzed and classified into stable (36%) and unstable (64%). Eight helpful roentgen signs were observed that may serve to direct attention to serious underlying, often occult, fractures and dislocations. The changes fall into four principal groups: abnormal soft tissues, abnormal vertebral alignment, abnormal joints, and widened vertebral canal. All stable and unstable lesions showed abnormal soft tissues, while 70% demonstrated kyphosis and/or scoliosis, and an abnormal adjacent intervertebral disk space. All unstable lesions showed one or more of the following signs: displaced vertebra, widened interspinous space, abnormalmore » apophyseal joint(s), and widened vertebral canal.« less

Specimen-specific modeling of hip fracture pattern and repair.

PubMed

Ali, Azhar A; Cristofolini, Luca; Schileo, Enrico; Hu, Haixiang; Taddei, Fulvia; Kim, Raymond H; Rullkoetter, Paul J; Laz, Peter J

2014-01-22

Hip fracture remains a major health problem for the elderly. Clinical studies have assessed fracture risk based on bone quality in the aging population and cadaveric testing has quantified bone strength and fracture loads. Prior modeling has primarily focused on quantifying the strain distribution in bone as an indicator of fracture risk. Recent advances in the extended finite element method (XFEM) enable prediction of the initiation and propagation of cracks without requiring a priori knowledge of the crack path. Accordingly, the objectives of this study were to predict femoral fracture in specimen-specific models using the XFEM approach, to perform one-to-one comparisons of predicted and in vitro fracture patterns, and to develop a framework to assess the mechanics and load transfer in the fractured femur when it is repaired with an osteosynthesis implant. Five specimen-specific femur models were developed from in vitro experiments under a simulated stance loading condition. Predicted fracture patterns closely matched the in vitro patterns; however, predictions of fracture load differed by approximately 50% due to sensitivity to local material properties. Specimen-specific intertrochanteric fractures were induced by subjecting the femur models to a sideways fall and repaired with a contemporary implant. Under a post-surgical stance loading, model-predicted load sharing between the implant and bone across the fracture surface varied from 59%:41% to 89%:11%, underscoring the importance of considering anatomic and fracture variability in the evaluation of implants. XFEM modeling shows potential as a macro-level analysis enabling fracture investigations of clinical cohorts, including at-risk groups, and the design of robust implants. © 2013 Published by Elsevier Ltd.

Comparison of tip apex distance and cut-out complications between helical blades and lag screws in intertrochanteric fractures among the elderly: a meta-analysis.

PubMed

Li, Shuang; Chang, Shi-Min; Niu, Wen-Xin; Ma, Hui

2015-11-01

To investigate whether helical blade implant systems have advantages in terms of tip apex distance (TAD) and cut-out rate in comparison to conventional lag screws for intertrochanteric fractures in a geriatric population. Methods: Relevant articles were sourced from the MEDLINE, Embase, Ovid and Cochrane Library databases from inception through March 2015. All randomized controlled trials (RCTs) comparing outcomes between helical blade and lag screw implant systems were selected. Mean TAD values and reported cut-out complications were noted. Each author independently assessed the relevance of the enrolled studies and the quality of the extracted data. Data were analyzed using R software. Ten studies including 1831 patients were eligible for this review, seven of which were included in a combined analysis of dichotomous outcomes and five in a combined analysis of continuous outcomes. The results revealed that, compared with lag screw implantations, the use of helical blades led to a lower rate of cut-out complications (95 % CI: 0.28–0.96, P = 0.036). Patients who experienced cut-out complications had a significantly greater tip apex distance (95 % CI: 0.68–1.34, P < 0.001). However, the actual tip apex distances were similar between the screw group and blade group (95 % CI: −0.44–0.79, P = 0.58). No difference in TAD values was found between blades and screws. In addition, the cut-out risk in the blade-design group was lower than that of the screw group. Therefore, TAD is not an accurate predictor of cut-out risk.

Fracture in Westerly granite under AE feedback and constant strain rate loading: Nucleation, quasi-static propagation, and the transition to unstable fracture propagation

USGS Publications Warehouse

Thompson, B.D.; Young, R.P.; Lockner, D.A.

2006-01-01

New observations of fracture nucleation are presented from three triaxial compression experiments on intact samples of Westerly granite, using Acoustic Emission (AE) monitoring. By conducting the tests under different loading conditions, the fracture process is demonstrated for quasi-static fracture (under AE Feedback load), a slowly developing unstable fracture (loaded at a 'slow' constant strain rate of 2.5 ?? 10-6/s) and an unstable fracture that develops near instantaneously (loaded at a 'fast' constant strain rate of 5 ?? 10-5/s). By recording a continuous ultrasonic waveform during the critical period of fracture, the entire AE catalogue can be captured and the exact time of fracture defined. Under constant strain loading, three stages are observed: (1) An initial nucleation or stable growth phase at a rate of ??? 1.3 mm/s, (2) a sudden increase to a constant or slowly accelerating propagation speed of ??? 18 mm/s, and (3) unstable, accelerating propagation. In the ??? 100 ms before rupture, the high level of AE activity (as seen on the continuous record) prevented the location of discrete AE events. A lower bound estimate of the average propagation velocity (using the time-to-rupture and the existing fracture length) suggests values of a few m/s. However from a low gain acoustic record, we infer that in the final few ms, the fracture propagation speed increased to 175 m/s. These results demonstrate similarities between fracture nucleation in intact rock and the nucleation of dynamic instabilities in stick slip experiments. It is suggested that the ability to constrain the size of an evolving fracture provides a crucial tool in further understanding the controls on fracture nucleation. ?? Birkha??user Verlag, Basel, 2006.

Femoral head wedge resection for the treatment of avascular necrosis of the femoral head after pediatric femoral neck fracture: a case report.

PubMed

Kim, Ha Yong; Cha, Yong Han; Choy, Won Sik; Jeung, Sang Wook; Min, Yeon Seung

2018-05-01

This research focuses on femoral head wedge resection for the treatment of avascular necrosis (AVN) of the femoral head. A 9-year-old girl presented to the emergency room complaining of right hip pain that occurred after a pedestrian car accident. After 8 months of internal fixation using cannulated screws for Delbet-type 2 fracture of the femoral neck, AVN of the femoral head developed in the patient. Even though valgus-derotation-extension intertrochanteric osteotomy was performed for the treatment of AVN, it progressed further and femoral head wedge resection was performed to recover the femoral head sphericity. After 3 years of follow-up, radiograph results showed appropriate and satisfactory congruency and containment. This research shows that the treatment of AVN of the femoral head using femoral head wedge resection is an effective method that can yield excellent results.

Stability of cervical spine fractures after gunshot wounds to the head and neck.

PubMed

Medzon, Ron; Rothenhaus, Todd; Bono, Christopher M; Grindlinger, Gene; Rathlev, Niels K

2005-10-15

Retrospective chart review. To determine the frequency of stable and unstable cervical spine fractures after gunshot wounds to the head or neck; to identify potential risk factor(s) for an unstable versus stable cervical spine fracture. Cervical spine fractures after gunshot wounds to the head and neck are common. Because of the nature of their injuries, patients often present with concomitant airway obstruction and large blood vessel injury that can necessitate emergent procedures. In some cases, acute treatment of these problems can be hindered by the presence of a cervical collar or strict adherence to spinal precautions (i.e., patient laying supine). In such situations, information regarding the probability of a stable versus unstable cervical spine fracture would be useful in emergency treatment decision making. A search for patients with gunshot wounds to the head or neck potentially involving the cervical spine over a 13-year period was performed using a trauma registry. Individuals with cervical spine fractures were identified and their records reviewed in detail. Data collected included information about neurologic deficits, mental status, airway treatment, entrance wounds, fracture level/type, initial/definitive fracture treatment, and final disposition at hospital discharge. A total of 81 patients were identified; 19 had cervical spine fractures. There were 5 patients who were not examinable because of altered mental status (severe head trauma, hemorrhagic shock, or intoxication). All 5 patients had stable cervical spine fractures. There were 11 patients who had an acute spinal cord injury, 3 (30%) of whom underwent surgery for an unstable fracture. Of the 65 awake, alert patients without a neurologic deficit, only 3 (5%) had a fracture, none of which were unstable. Gunshot wounds to the head and neck had a high rate of concomitant cervical spine fracture. Neurologically intact patients have a lower rate of fracture than those presenting with a spinal cord injury or altered mental status. In this small series of patients, the only unstable cervical spine injuries were detected in patients with a spinal cord injury. The data suggest that spinal precautions and/or a hard cervical collar should not be maintained at the expense of delaying or hindering emergent life-saving airway or hemodynamically stabilizing procedures, particularly in awake, neurologically intact patients. However, the cervical collar and spinal precautions should be resumed after such procedures are completed and continued until a more definitive evaluation of spinal stability can be performed.

Using decision analysis to assess comparative clinical efficacy of surgical treatment of unstable ankle fractures.

PubMed

Michelson, James D

2013-11-01

The development of a robust treatment algorithm for ankle fractures based on well-established stability criteria has been shown to be prognostic with respect to treatment and outcomes. In parallel with the development of improved understanding of the biomechanical rationale of ankle fracture treatment has been an increased emphasis on assessing the effectiveness of medical and surgical interventions. The purpose of this study was to investigate the use of using decision analysis in the assessment of the cost effectiveness of operative treatment of ankle fractures based on the existing clinical data in the literature. Using the data obtained from a previous structured review of the ankle fracture literature, decision analysis trees were constructed using standard software. The decision nodes for the trees were based on ankle fracture stability criteria previously published. The outcomes were assessed by calculated Quality-Adjusted Life Years (QALYs) assigned to achieving normal ankle function, developing posttraumatic arthritis, or sustaining a postoperative infection. Sensitivity analysis was undertaken by varying the patient's age, incidence of arthritis, and incidence or infection. Decision analysis trees captured the essential aspects of clinical decision making in ankle fracture treatment in a clinically useful manner. In general, stable fractures yielded better outcomes with nonoperative treatment, whereas unstable fractures had better outcomes with surgery. These were consistent results over a wide range of postoperative infection rates. Varying the age of the patient did not qualitatively change the results. Between the ages of 30 and 80 years, surgery yielded higher expected QALYs than nonoperative care for unstable fractures, and generated lower QALYs than nonoperative care for stable fractures. Using local cost estimates for operative and nonoperative treatment, the incremental cost of surgery for unstable fractures was less than $40,000 per QALY (the usual cutoff for the determination of cost effectiveness) for patients aged up to 90 years. Decision analysis is a useful methodology in developing treatment guidelines. Numerous previous studies have indicated superior clinical outcomes when unstable ankle fractures underwent operative reduction and stabilization. What has been lacking was an examination of the cost effectiveness of such an approach, particularly in older patients who have fewer expected years of life. In light of the evidence for satisfactory outcomes for surgery of severe ankle fractures in older people, the justification for operative intervention is an obvious question that can be asked in the current increasingly cost-conscious environment. Using a decision-tree decision analysis structured around the stability-based ankle fracture classification system, in conjunction with a relatively simple cost effectiveness analysis, this study was able to demonstrate that surgical treatment of unstable ankle fractures in elderly patients is in fact cost effective. The clinical implication of the present analysis is that these existing treatment protocols for ankle fracture treatment are also cost effective when quality of life outcome measures are taken into account. Economic Level II. See Instructions for Authors for a complete description of levels of evidence.

Characterization of the 3-D fracture setting of an unstable rock mass: From surface and seismic investigations to numerical modeling

NASA Astrophysics Data System (ADS)

Colombero, C.; Baillet, L.; Comina, C.; Jongmans, D.; Vinciguerra, S.

2017-08-01

The characterization of the fracturing state of a potentially unstable rock cliff is a crucial requirement for stability assessments and mitigation purposes. Classical measurements of fracture location and orientation can however be limited by inaccessible rock exposures. The steep topography and high-rise morphology of these cliffs, together with the widespread presence of fractures, can additionally condition the success of geophysical prospecting on these sites. In order to mitigate these limitations, an innovative approach combining noncontact geomechanical measurements, active and passive seismic surveys, and 3-D numerical modeling is proposed in this work to characterize the 3-D fracture setting of an unstable rock mass, located in NW Italian Alps (Madonna del Sasso, VB). The 3-D fracture geometry was achieved through a combination of field observations and noncontact geomechanical measurements on oriented pictures of the cliff, resulting from a previous laser-scanning and photogrammetric survey. The estimation of fracture persistence within the rock mass was obtained from surface active seismic surveys. Ambient seismic noise and earthquakes recordings were used to assess the fracture control on the site response. Processing of both data sets highlighted the resonance properties of the unstable rock volume decoupling from the stable massif. A finite element 3-D model of the site, including all the retrieved fracture information, enabled both validation and interpretation of the field measurements. The integration of these different methodologies, applied for the first time to a complex 3-D prone-to-fall mass, provided consistent information on the internal fracturing conditions, supplying key parameters for future monitoring purposes and mitigation strategies.

Analysis of PITFL injuries in rotationally unstable ankle fractures.

PubMed

Warner, Stephen J; Garner, Matthew R; Schottel, Patrick C; Hinds, Richard M; Loftus, Michael L; Lorich, Dean G

2015-04-01

Reduction and stabilization of the syndesmosis in unstable ankle fractures is important for ankle mortise congruity and restoration of normal tibiotalar contact forces. Of the syndesmotic ligaments, the posterior inferior tibiofibular ligament (PITFL) provides the most strength for maintaining syndesmotic stability, and previous work has demonstrated the significance of restoring PITFL function when it remains attached to a posterior malleolus fracture fragment. However, little is known regarding the nature of a PITFL injury in the absence of a posterior malleolus fracture. The goal of this study was to describe the PITFL injury pattern based on magnetic resonance imaging (MRI) and intraoperative observation. A prospective database of all operatively treated ankle fractures by a single surgeon was used to identify all supination-external rotation (SER) types III and IV ankle fracture patients with complete preoperative orthogonal ankle radiographs and MRI. All patients with a posterior malleolus fracture were excluded. Using a combination of preoperative imaging and intraoperative findings, we analyzed the nature of injuries to the PITFL. In total, 185 SER III and IV operatively treated ankle fractures with complete imaging were initially identified. Analysis of the preoperative imaging and operative reports revealed 34% (63/185) had a posterior malleolus fracture and were excluded. From the remaining 122 ankle fractures, the PITFL was delaminated from the posterior malleolus in 97% (119/122) of cases. A smaller proportion (3%; 3/122) had an intrasubstance PITFL rupture. Accurate and stable syndesmotic reduction is a significant component of restoring the ankle mortise after unstable ankle fractures. In our large cohort of rotationally unstable ankle fractures without posterior malleolus fractures, we found that most PITFL injuries occur as a delamination off the posterior malleolus. This predictable PITFL injury pattern may be used to guide new methods for stabilizing the syndesmosis in these patients. Level IV, case series. © The Author(s) 2014.

[Fractures of the proximal interphalangeal joint: Diagnostic and operative therapy options].

PubMed

Unglaub, F; Langer, M F; Hahn, P; Müller, L P; Ahrens, C; Spies, C K

2016-02-01

Joint fractures of the fingers often entail operative interventions in contrast to extra-articular fractures. These types of fracture are inclined to dislocate in addition to the actual fracture. The proximal interphalangeal (PIP) joint in particular often shows comminuted fractures due to the long leverage of the finger and a relatively small diameter of the joint. The clinical examination, X-ray diagnostics and if necessary computed tomography allow the classification into stable and unstable fractures. Unstable fractures must be treated by surgical reduction and fixation. A multitude of operative techniques are available for these mostly complicated fractures. The foremost goal is a stable osteosynthesis of the fracture with repositioning of the dislocation, which enables early physiotherapy in order to prevent tendon adhesion and contracture. This article presents the different types of PIP joint fractures, their specific surgical treatment and postoperative treatment regimens.

Accuracy of screw fixation using the O-arm® and StealthStation® navigation system for unstable pelvic ring fractures.

PubMed

Takeba, Jun; Umakoshi, Kensuke; Kikuchi, Satoshi; Matsumoto, Hironori; Annen, Suguru; Moriyama, Naoki; Nakabayashi, Yuki; Sato, Norio; Aibiki, Mayuki

2018-04-01

Screw fixation for unstable pelvic ring fractures is generally performed using the C-arm. However, some studies reported erroneous piercing with screws, nerve injuries, and vessel injuries. Recent studies have reported the efficacy of screw fixations using navigation systems. The purpose of this retrospective study was to investigate the accuracy of screw fixation using the O-arm ® imaging system and StealthStation ® navigation system for unstable pelvic ring fractures. The participants were 10 patients with unstable pelvic ring fractures, who underwent screw fixations using the O-arm StealthStation navigation system (nine cases with iliosacral screw and one case with lateral compression screw). We investigated operation duration, bleeding during operation, the presence of complications during operation, and the presence of cortical bone perforation by the screws based on postoperative CT scan images. We also measured the difference in screw tip positions between intraoperative navigation screen shot images and postoperative CT scan images. The average operation duration was 71 min, average bleeding was 12 ml, and there were no nerve or vessel injuries during the operation. There was no cortical bone perforation by the screws. The average difference between intraoperative navigation images and postoperative CT images was 2.5 ± 0.9 mm, for all 18 screws used in this study. Our results suggest that the O-arm StealthStation navigation system provides accurate screw fixation for unstable pelvic ring fractures.

Weight-Bearing Cone-Beam CT Scan Assessment of Stability of Supination External Rotation Ankle Fractures in a Cadaver Model.

PubMed

Lawlor, Mark C; Kluczynski, Melissa A; Marzo, John M

2018-03-01

The utility of computed tomography (CT) for measuring medial clear space (MCS) for determination of the stability of supination external rotation (SER) ankle fractures and in comparison to standard radiographs is unknown. We compared MCS on gravity stress (GS) radiographs to GS and weight bearing (WB) cone-beam CT (CBCT). An AO SER 44B3.1 ankle fracture was simulated in 10 human cadavers, also serving as controls. MCS was measured on GS radiographs, GS CBCT, and a simulated WB CBCT scan. Specimens were stable if MCS was <5 mm and unstable if MCS was ≥5 mm. Paired t tests were used to compare MCS from each imaging modality for controls versus SER injuries and stable versus unstable specimens. Compared with controls assessed by GS radiographs, MCS was greater for an SER injury when assessed by GS radiograph and GS CBCT scan within the stable group. Compared with controls assessed by GS radiographs, MCS was greater for SER injuries when assessed by GS radiograph, GS CBCT scan, and WB CBCT within the unstable group. MCS was reduced for stable versus unstable SER injuries assessed by WB CBCT. In a cadaveric model of SER ankle fracture, the medial clear space was statistically significantly greater for the experimental condition when assessed by gravity stress radiograph and gravity stress CBCT scan. Under weight-bearing conditions, the cone-beam CT scanner distinguished between stable and unstable ankles in the experimental condition. This study suggests that a WB cone-beam CT scan may be able to distinguish between stable and unstable SER ankle fractures and influence operative decision making.

Sensitivity and specificity of CT- and MRI-scanning in evaluation of occult fracture of the proximal femur.

PubMed

Haubro, M; Stougaard, C; Torfing, T; Overgaard, S

2015-08-01

To estimate sensitivity and specificity of CT and MRI examinations in patients with fractures of the proximal femur. To determine the interobserver agreement of the modalities among a senior consulting radiologist, a resident in radiology and a resident in orthopaedics surgery. 67 patients (27 males, 40 females, mean age 80.5) seen in the emergency room with hip pain after fall, inability to stand and a primary X-ray without fracture were evaluated with both CT and MRI. The images were analysed by a senior consulting musculoskeletal radiologist, a resident in radiology and a resident in orthopaedic surgery. Sensitivity and specificity were estimated with MRI as the golden standard. Kappa value was used to assess level of agreement in both MRI and CT finding. 15 fractures of the proximal femur were found (7 intertrochanteric-, 3 femoral neck and 5 fractures of the greater trochanter). Two fractures were not identified by CT and four changed fracture location. Among those, three patients underwent surgery. Sensitivity of CT was 0.87; 95% CI [0.60; 0.98]. Kappa for interobserver agreement for CT were 0.46; 95% CI [0.23; 0.76] and 0.67; 95% CI [0.42; 0.90]. For MRI 0.67; 95% CI [0.43; 0.91] and 0.69; 95% CI [0.45; 0.92]. MRI was observed to have a higher diagnostic accuracy than CT in detecting occult fractures of the hip. Interobserver analysis showed high kappa values corresponding substantial agreement in both CT and MRI. Copyright © 2015 Elsevier Ltd. All rights reserved.

Self-designed posterior atlas polyaxial lateral mass screw-plate fixation for unstable atlas fracture.

PubMed

He, Baorong; Yan, Liang; Zhao, Qinpeng; Chang, Zhen; Hao, Dingjun

2014-12-01

Most atlas fractures can be effectively treated nonoperatively with external immobilization unless there is an injury to the transverse atlantal ligament. Surgical stabilization is most commonly achieved using a posterior approach with fixation of C1-C2 or C0-C2, but these treatments usually result in loss of the normal motion of the C1-C2 and C0-C1 joints. To clinically validate feasibility, safety, and value of open reduction and fixation using an atlas polyaxial lateral mass screw-plate construct in unstable atlas fractures. Retrospective review of patients who sustained unstable atlas fractures treated with polyaxial lateral mass screw-plate construct. Twenty-two patients with unstable atlas fractures who underwent posterior atlas polyaxial lateral mass screw-plate fixation were analyzed. Visual analog scale, neurologic status, and radiographs for fusion. From January 2011 to September 2012, 22 patients with unstable atlas fractures were treated with this technique. Patients' charts and radiographs were reviewed. Bone fusion, internal fixation placement, and integrity of spinal cord and vertebral arteries were assessed via intraoperative and follow-up imaging. Neurologic function, range of motion, and pain levels were assessed clinically on follow-up. All patients were followed up from 12 to 32 months, with an average of 22.5±18.0 months. A total of 22 plates were placed, and all 44 screws were inserted into the atlas lateral masses. The mean duration of the procedure was 86 minutes, and the average estimated blood loss was 120 mL. Computed tomography scans 9 months after surgery confirmed that fusion was achieved in all cases. There was no screw or plate loosening or breakage in any patient. All patients had well-preserved range of motion. No vascular or neurologic complication was noted, and all patients had a good clinical outcome. An open reduction and posterior internal fixation with atlas polyaxial lateral mass screw-plate is a safe and effective surgical option in the treatment of unstable atlas fractures. This technique can provide immediate reduction and preserve C1-C2 motion. Copyright © 2014 Elsevier Inc. All rights reserved.

Early Weightbearing After Operatively Treated Ankle Fractures: A Biomechanical Analysis.

PubMed

Tan, Eric W; Sirisreetreerux, Norachart; Paez, Adrian G; Parks, Brent G; Schon, Lew C; Hasenboehler, Erik A

2016-06-01

No consensus exists regarding the timing of weightbearing after surgical fixation of unstable traumatic ankle fractures. We evaluated fracture displacement and timing of displacement with simulated early weightbearing in a cadaveric model. Twenty-four fresh-frozen lower extremities were assigned to Group 1, bimalleolar ankle fracture (n=6); Group 2, trimalleolar ankle fracture with unfixed small posterior malleolar fracture (n=9); or Group 3, trimalleolar ankle fracture with fixed large posterior malleolar fracture (n=9) and tested with axial compressive load at 3 Hz from 0 to 1000 N for 250 000 cycles to simulate 5 weeks of full weightbearing. Displacement was measured by differential variable reluctance transducer. The average motion at all fracture sites in all groups was significantly less than 1 mm (P < .05). Group 1 displacement of the lateral and medial malleolus fracture was 0.1±0.1 mm and 0.4±0.4 mm, respectively. Group 2 displacement of the lateral, medial, and posterior malleolar fracture was 0.6±0.4 mm, 0.5±0.4 mm, and 0.5±0.6 mm, respectively. Group 3 displacement of the lateral, medial, and posterior malleolar fracture was 0.1±0.1 mm, 0.5±0.7 mm, and 0.5±0.4 mm, respectively. The majority of displacement (64.0% to 92.3%) occurred in the first 50 000 cycles. There was no correlation between fracture displacement and bone mineral density. No significant fracture displacement, no hardware failure, and no new fractures occurred in a cadaveric model of early weightbearing in unstable ankle fracture after open reduction and internal fixation. This study supports further investigation of early weightbearing postoperative protocols after fixation of unstable ankle fractures. © The Author(s) 2016.

A Technique to Allow Prone Positioning in the Spine Surgery Patient With Unstable Spine Fracture and Flail Segment Rib Fractures.

PubMed

Pennington, Matthew W; Roche, Anthony M; Bransford, Richard J; Zhang, Fangyi; Dagal, Armagan

2016-07-01

Two patients with unstable thoracic spine and flail segment rib fractures initially failed prone positioning on a Jackson spinal table used for posterior spinal instrumentation and fusion surgery. Both patients experienced rapid hemodynamic collapse. We developed a solution using the anterior portions of a thoracolumbosacral orthosis brace as chest supports to use during prone positioning, allowing both patients to undergo uncomplicated posterior spinal instrumentation and fusion surgeries with greater hemodynamic stability.

Modular femoral component for conversion of previous hip surgery in total hip arthroplasty.

PubMed

Goldstein, Wayne M; Branson, Jill J

2005-09-01

The conversion of previous hip surgery to total hip arthroplasty creates a durable construct that is anatomically accurate. Most femoral components with either cemented or cementless design have a fixed tapered proximal shape. The proximal femoral anatomy is changed due to previous hip surgery for fixation of an intertrochanteric hip fracture, proximal femoral osteotomy, or a fibular allograft for avascular necrosis. The modular S-ROM (DePuy Orthopaedics Inc., Warsaw, Ind) hip stem accommodates these issues and independently prepares the proximal and distal portion of the femur. In preparation and implantation, the S-ROM hip stem creates less hoop stresses on potentially fragile stress risers from screws and thin bone. The S-ROM hip stem also prepares a previously distorted anatomy by milling through cortical bone that can occlude the femoral medullar canals and recreate proper femoral anteversion and reduces the risk of intraoperative or postoperative periprosthetic fracture due to the flexible titanium-slotted stem. The S-ROM femoral stem is recommended for challenging total hip reconstructions.

Use of plate fixation without coracoclavicular ligament augmentation for unstable distal clavicle fractures.

PubMed

Shin, Sang-Jin; Ko, Young-Won; Lee, Juyeob; Park, Min-Gyue

2016-06-01

The purpose of this study was to evaluate the clinical and radiologic outcomes of unstable distal clavicle fractures treated with anatomic plate fixation without coracoclavicular ligament augmentation and to compare the outcome of Neer type IIA with that of type IIB. Twenty-five patients with unstable distal clavicle fractures who underwent anatomic plate fixation without coracoclavicular ligament augmentation were enrolled prospectively, including 9 patients of Neer type IIA and 16 patients of Neer type IIB. Clinical outcomes were evaluated using Constant and University of California-Los Angeles (UCLA) scores. Coracoclavicular distance was measured on plain radiographs. Bone union was achieved in all patients. Satisfactory clinical and radiologic outcomes were obtained regardless of fracture type. After operation, the mean coracoclavicular distance on the injured side was increased by 10% compared with the uninjured side. However, between the patients who showed an increased coracoclavicular distance >10% (Constant score, 89.4 ± 3.7; UCLA score, 32.6 ± 3) and the patients with increased coracoclavicular distance <10% of the uninjured side (Constant score, 88.7 ± 3.6; UCLA score, 31.9 ± 3), there was no statistically significant difference in clinical outcomes of Constant score (P = .934) and UCLA score (P = .598). In unstable distal clavicle fractures, precontoured anatomic plate fixation without coracoclavicular ligament augmentation showed satisfactory clinical outcomes and high union rates even with a small lateral fragment. Patients who had increased coracoclavicular distance also demonstrated satisfactory shoulder functional outcomes regardless of the fracture type. Therefore, anatomic plate fixation without additional coracoclavicular ligament augmentation can be considered one of the treatment options for unstable distal clavicle fracture. Level IV; Case Series; Treatment Study. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Mortality Following Periprosthetic Proximal Femoral Fractures Versus Native Hip Fractures.

PubMed

Boylan, Matthew R; Riesgo, Aldo M; Paulino, Carl B; Slover, James D; Zuckerman, Joseph D; Egol, Kenneth A

2018-04-04

The number of periprosthetic proximal femoral fractures is expected to increase with the increasing prevalence of hip arthroplasties. While native hip fractures have a well-known association with mortality, there are currently limited data on this outcome among the subset of patients with periprosthetic proximal femoral fractures. Using the New York Statewide Planning and Research Cooperative System, we identified patients from 60 to 99 years old who were admitted to a hospital in the state with a periprosthetic proximal femoral fracture (n = 1,655) or a native hip (femoral neck or intertrochanteric) fracture (n = 97,231) between 2006 and 2014. Within the periprosthetic fracture cohort, the indication for the existing implant was not available in the data set. We used mixed-effects regression models to compare mortality at 1 and 6 months and 1 year for periprosthetic compared with native hip fractures. The risk of mortality for patients who sustained a periprosthetic proximal femoral fracture was no different from that for patients who sustained a native hip fracture at 1 month after injury (3.2% versus 4.6%; odds ratio [OR], 0.90; 95% confidence interval [CI], 0.68 to 1.19; p = 0.446), but was lower at 6 months (3.8% versus 6.5%; OR, 0.74; 95% CI, 0.57 to 0.95; p = 0.020) and 1 year (9.7% versus 15.9%; OR, 0.71; 95% CI, 0.60 to 0.85; p < 0.001). Among periprosthetic proximal femoral fractures, factors associated with a significantly increased risk of mortality at 1 year included advanced age, male sex, and higher Deyo comorbidity scores. In the acute phase, any type of hip fracture appears to confer a similar risk of death. Over the long term, however, periprosthetic proximal femoral fractures are associated with lower mortality rates than native hip fractures, even after accounting for age and comorbidities. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Triangular osteosynthesis of vertically unstable sacrum fractures: a new concept allowing early weight-bearing.

PubMed

Schildhauer, T A; Josten, Ch; Muhr, G

2006-01-01

Presentation of a new triangular osteosynthesis technique that permits early weight-bearing in vertically unstable sacral fractures. : Retrospective evaluation of a consecutive series. Level I trauma center. Thirty-four patients, twenty-eight of whom were poly-traumatized, all with vertically unstable sacral fractures. This group included eight women and twenty-six men, with a mean age of thirty-five years. Average time between trauma and definite operation was thirteen days (range 0 to 28 days). All patients underwent triangular osteosynthesis using a combination of a vertical vertebro-pelvic distraction osteosynthesis (pedicle screw system) and a transverse fixation of the sacrum fracture with either iliosacral screws or trans-sacral plating. Immediate postoperative weight-bearing was permitted postoperatively. Nineteen patients were treated with early progressive weight-bearing and advanced to full weight-bearing, on average, after twenty-three days (range 8 to 70 days). Three of the thirty-four patients (9 percent) experienced loosening of hardware, including two patients (6 percent) who required secondary intervention because of loss of the original reduction. Further complications included one pulmonary embolism (3 percent), one iatrogenic nerve lesion (3 percent), one wound necrosis (3 percent), and two local infections (6 percent). Triangular osteosynthesis is a demanding procedure that can be performed on vertically unstable sacral fractures to allow early progressive weight-bearing with an acceptable complication rate.

Injuries in Full-Scale Vehicle Side Impact Moving Deformable Barrier and Pole Tests Using Postmortem Human Subjects.

PubMed

Yoganandan, Narayan; Pintar, Frank; Humm, John; Rudd, Rodney

2015-01-01

To conduct near-side moving deformable barrier (MDB) and pole tests with postmortem human subjects (PMHS) in full-scale modern vehicles, document and score injuries, and examine the potential for angled chest loading in these tests to serve as a data set for dummy biofidelity evaluations and computational modeling. Two PMHS (outboard left front and rear seat occupants) for MDB and one PMHS (outboard left front seat occupant) for pole tests were used. Both tests used sedan-type vehicles from same manufacturer with side airbags. Pretest x-ray and computed tomography (CT) images were obtained. Three-point belt-restrained surrogates were positioned in respective outboard seats. Accelerometers were secured to T1, T6, and T12 spines; sternum and pelvis; seat tracks; floor; center of gravity; and MDB. Load cells were used on the pole. Biomechanical data were gathered at 20 kHz. Outboard and inboard high-speed cameras were used for kinematics. X-rays and CT images were taken and autopsy was done following the test. The Abbreviated Injury Scale (AIS) 2005 scoring scheme was used to score injuries. MDB test: male (front seat) and female (rear seat) PMHS occupant demographics: 52 and 57 years, 177 and 166 cm stature, 78 and 65 kg total body mass. Demographics of the PMHS occupant in the pole test: male, 26 years, 179 cm stature, and 84 kg total body mass. Front seat PMHS in MDB test: 6 near-side rib fractures (AIS = 3): 160-265 mm vertically from suprasternal notch and 40-80 mm circumferentially from center of sternum. Left rear seat PMHS responded with multiple bilateral rib fractures: 9 on the near side and 5 on the contralateral side (AIS = 3). One rib fractured twice. On the near and contralateral sides, fractures were 30-210 and 20-105 mm vertically from the suprasternal notch and 90-200 and 55-135 mm circumferentially from the center of sternum. A fracture of the left intertrochanteric crest occurred (AIS = 3). Pole test PMHS had one near-side third rib fracture. Thoracic accelerations of the 2 occupants were different in the MDB test. Though both occupants sustained positive and negative x-accelerations to the sternum, peak magnitudes and relative changes were greater for the rear than the front seat occupant. Magnitudes of the thoracic and sternum accelerations were lower in the pole test. This is the first study to use PMHS occupants in MDB and pole tests in the same recent model year vehicles with side airbag and head curtain restraints. Injuries to the unilateral thorax for the front seat PMHS in contrast to the bilateral thorax and hip for the rear seat occupant in the MDB test indicate the effects of impact on the seating location and restraint system. Posterolateral locations of fractures to the front seat PMHS are attributed to constrained kinematics of occupant interaction with torso side airbag restraint system. Angled loading to the rear seat occupant from coupled sagittal and coronal accelerations of the sternum representing anterior thorax loading contributed to bilateral fractures. Inward bending initiated by the distal femur complex resulting in adduction of ipsilateral lower extremity resulted in intertrochanteric fracture to the rear seat occupant. These results serve as a data set for evaluating the biofidelity of the WorldSID and federalized side impact dummies and assist in validating human body computational models, which are increasingly used in crashworthiness studies.

Dose--effect relationships for femoral fractures after multimodality limb-sparing therapy of soft-tissue sarcomas of the proximal lower extremity.

PubMed

Pak, Daniel; Vineberg, Karen A; Griffith, Kent A; Sabolch, Aaron; Chugh, Rashmi; Ben-Josef, Edgar; Biermann, Janet Sybil; Feng, Mary

2012-07-15

We investigated the clinical and dosimetric predictors for radiation-associated femoral fractures in patients with proximal lower extremity soft tissue sarcomas (STS). We examined 131 patients with proximal lower extremity STS who received limb-sparing surgery and external-beam radiation therapy between 1985 and 2006. Five (4%) patients sustained pathologic femoral fractures. Dosimetric analysis was limited to 4 fracture patients with full three-dimensional dose information, who were compared with 59 nonfracture patients. The mean doses and volumes of bone (V(d)) receiving specified doses (≥30 Gy, 45 Gy, 60 Gy) at the femoral body, femoral neck, intertrochanteric region, and subtrochanteric region were compared. Clinical predictive factors were also evaluated. Of 4 fracture patients in our dosimetric series, there were three femoral neck fractures with a mean dose of 57.6 ± 8.9 Gy, V30 of 14.5 ± 2.3 cc, V45 of 11.8 ± 1.1 cc, and V60 of 7.2 ± 2.2 cc at the femoral neck compared with 22.9 ± 20.8 Gy, 4.8 ± 5.6 cc, 2.5 ± 3.9 cc, and 0.8 ± 2.7 cc, respectively, for nonfracture patients (p < 0.03 for all). The femoral neck fracture rate was higher than at the subtrochanteric region despite lower mean doses at these subregions. All fracture sites received mean doses greater than 40 Gy. Also, with our policy of prophylactic femoral intramedullary nailing for high-risk patients, there was no significant difference in fracture rates between patients with and without periosteal excision. There were no significant differences in age, sex, tumor size, timing of radiation therapy, and use of chemotherapy between fracture and nonfracture patients. These dose-volume toxicity relationships provide RT optimization goals to guide future efforts for reducing pathologic fracture rates. Prophylactic femoral intramedullary nailing may also reduce fracture risk for susceptible patients. Copyright © 2012 Elsevier Inc. All rights reserved.

The outcome of surgically treated traumatic unstable pelvic fractures by open reduction and internal fixation.

PubMed

Mardanpour, Keykhosro; Rahbar, Mahtab

2013-07-01

This study was performed to evaluate functional and radiological results of pelvic ring fractures treatment by open reduction and internal fixation. Thirty eight patients with unstable pelvic fractures, treated from 2002 to 2008 were retrospectively reviewed. The mean patients' age was 37 years (range 20 to 67). Twenty six patients were men (4 patients with type B and 22 patients with type C fracture) and 12 women (7 patients with type B and 5 patients with type C fracture). The commonest cause was a road traffic accident (N=37, about 97%). Internal fixation was done by plaque with ilioinguinal and Kocher-Langenbeek approaches for anterior, posterior pelvic wall and acetabulum fracture respectively. Quality of reduction was graded according to Majeed score system. There were 11 type-C and 27 type-B pelvic fractures according to Tile's classification. Thirty six patients sustained additional injuries. The commonest additional injury was lower extremity fracture. The mean follow-up was 45.6 months (range 16 to 84 months).The functional outcome was excellent in 66%, good in 15%, fair in 11% and poor in 7% of the patients with type B pelvic fractures and functional outcome was excellent in 46%, good in 27%, fair in 27% and poor in 0% of the patients with type C pelvic fractures. There were four postoperative infections. No sexual functional problem was reported. Neurologic problem like Lateral cutaneous nerve of thigh injury recovered completely in 2 patients and partially in 2 patients. There was no significant relation between functional outcome and the site of fracture (P greater than 0.005). Unstable pelvic ring fracture injuries should be managed surgically by rigid stabilization. It must be carried out as soon as the general condition of the patient permits, and even up to two weeks.

Treatment of inherently unstable open or infected fractures by open wound management and external skeletal fixation.

PubMed

Ness, M G

2006-02-01

To assess the use of external skeletal fixation with open wound management for the treatment of inherently unstable open or infected fractures in dogs. A retrospective review of 10 cases. Fracture stabilisation and wound management required only a single anaesthetic, and despite the challenging nature of these injuries, the final outcome was acceptable or good in every case. However, minor complications associated with the fixator pins were quite common, and two dogs developed complications which required additional surgery. Open management of wounds, even when bone was exposed, proved to be an effective technique, and external skeletal fixators were usually effective at maintaining stability throughout an inevitably extended fracture healing period.

Posterior fixation including the fractured vertebra for severe unstable thoracolumbar fractures.

PubMed

Kanna, Rishi M; Shetty, Ajoy Prasad; Rajasekaran, S

2015-02-01

Traditional short-segment fixation of unstable thoracolumbar injuries can be associated with progressive kyphosis and implant failure. Load sharing classification (LSC) recommends supplemental anterior reconstruction for fractures of score 7 or greater. Posterior fixation including the fractured vertebra (PFFV) has biomechanical advantages over conventional short-segment fixation. However, its efficacy in severe thoracolumbar injuries (LSC≥7) has not been studied. To study the clinical, functional, and radiologic results of PFFV for severe, unstable thoracolumbar injuries (LSC≥7) at a minimum of 2 years. A retrospective review of case records. Thirty-two patients with an unstable burst fracture of LSC≥7 treated with PFFV were included. They included clinical outcomes: American Spinal Injury Association grade, visual analog scale (VAS), Oswestry Disability Index (ODI); and radiologic measures: segmental kyphosis angle, vertebral wedge angle, and percentage loss of anterior and posterior vertebral height. Thirty-two patients with LSC≥7 who had undergone PFFV, with a minimum follow-up of 2 years were studied for demographic, injury, and surgical details. Clinical and radiologic outcomes were measured before surgery and at 6, 12, and 24 months postoperatively. The presence of screw breakage, screw pullout, peri-implant loosening, and rod breakage were considered as criteria for implant failure. None of the patients had postoperative implant failure at the final follow-up. The mean preoperative kyphosis angle was 22.9°±7.6°. This improved significantly to 9.2°±6.6° after surgery (p=.000). There was a loss of mean 2.4° (mean kyphosis angle of 11.6°±6.3°) at the final follow-up. The mean preoperative wedge angle was 23.0°±8.1°. This was corrected to 9.7°±6.2° (p=.000). There was a loss of kyphosis (mean 1.2°) in the follow-up period. The mean anterior and posterior vertebral height also showed significant improvements postoperatively, which were maintained at the final follow-up. The mean ODI and VAS scores at the end of 2 years were 17.5% and 1.6, respectively. Reduction of unstable thoracolumbar injuries even with LSC≥7 can be achieved and maintained with the use of short-segment pedicle screw fixation including the fractured vertebra, avoiding the need for anterior reconstruction. In the current era of evolving concepts of fracture fixation, the relevance of LSC in the management of unstable burst fractures is questionable. Copyright © 2015 Elsevier Inc. All rights reserved.

Modified tension band fixation and coracoclavicular stabilisation for unstable distal clavicle fracture.

PubMed

Choi, Sungwook; Kim, Sang-Rim; Kang, Hyunseong; Kim, Donghee; Park, Yong-Geun

2015-02-01

The purpose of this study was to report a new surgical technique for the treatment of unstable distal clavicle fracture with modified tension band fixation (MTBF) and coracoclavicular (CC) stabilisation, and evaluate the radiologic and clinical outcome of these patients. Thirteen patients who had a fracture of the distal clavicle (Neer classification type IIb) were treated with MTBF and CC stabilisation. After the CC stabilisation was performed with a suture anchor or flip button, internal fixation using MTBF was carried out. Each patient was followed up for a minimum of 12 months and their clinical and radiological results were analysed. The mean period required for fracture union was 12.6 (range, 8-24) weeks and union was successfully completed in all cases. The mean Constant score at the final follow-up was 94.7 (88-100); the modified University of California, Los Angeles (UCLA) shoulder rating scale was 31.3 points (range, 22-35). All patients returned to normal daily activities at an average of 3.7 months postoperatively (range, 3-5 months). One patient had a new fracture around drilled holes for CC stabilisation by inappropriate tunnelling. MTBF and CC stabilisation is a useful technique for treating an unstable distal clavicle fracture. This procedure provides minimal incision and stable fixation without causing any further acromioclavicular joint injury to those with distal clavicle fractures. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison of hip geometry, strength, and estimated fracture risk in women with anorexia nervosa and overweight/obese women.

PubMed

Bachmann, Katherine Neubecker; Fazeli, Pouneh K; Lawson, Elizabeth A; Russell, Brian M; Riccio, Ariana D; Meenaghan, Erinne; Gerweck, Anu V; Eddy, Kamryn; Holmes, Tara; Goldstein, Mark; Weigel, Thomas; Ebrahimi, Seda; Mickley, Diane; Gleysteen, Suzanne; Bredella, Miriam A; Klibanski, Anne; Miller, Karen K

2014-12-01

Data suggest that anorexia nervosa (AN) and obesity are complicated by elevated fracture risk, but skeletal site-specific data are lacking. Traditional bone mineral density (BMD) measurements are unsatisfactory at both weight extremes. Hip structural analysis (HSA) uses dual-energy X-ray absorptiometry data to estimate hip geometry and femoral strength. Factor of risk (φ) is the ratio of force applied to the hip from a fall with respect to femoral strength; higher values indicate higher hip fracture risk. The objective of the study was to investigate hip fracture risk in AN and overweight/obese women. This was a cross-sectional study. The study was conducted at a Clinical Research Center. PATIENTS included 368 women (aged 19-45 y): 246 AN, 53 overweight/obese, and 69 lean controls. HSA-derived femoral geometry, peak factor of risk for hip fracture, and factor of risk for hip fracture attenuated by trochanteric soft tissue (φ(attenuated)) were measured. Most HSA-derived parameters were impaired in AN and superior in obese/overweight women vs controls at the narrow neck, intertrochanteric, and femoral shaft (P ≤ .03). The φ(attenuated) was highest in AN and lowest in overweight/obese women (P < .0001). Lean mass was associated with superior, and duration of amenorrhea with inferior, HSA-derived parameters and φ(attenuated) (P < .05). Mean φ(attenuated) (P = .036), but not femoral neck BMD or HSA-estimated geometry, was impaired in women who had experienced fragility fractures. Femoral geometry by HSA, hip BMD, and factor of risk for hip fracture attenuated by soft tissue are impaired in AN and superior in obesity, suggesting higher and lower hip fracture risk, respectively. Only attenuated factor of risk was associated with fragility fracture prevalence, suggesting that variability in soft tissue padding may help explain site-specific fracture risk not captured by BMD.

Comparison of Hip Geometry, Strength, and Estimated Fracture Risk in Women With Anorexia Nervosa and Overweight/Obese Women

PubMed Central

Bachmann, Katherine Neubecker; Fazeli, Pouneh K.; Lawson, Elizabeth A.; Russell, Brian M.; Riccio, Ariana D.; Meenaghan, Erinne; Gerweck, Anu V.; Eddy, Kamryn; Holmes, Tara; Goldstein, Mark; Weigel, Thomas; Ebrahimi, Seda; Mickley, Diane; Gleysteen, Suzanne; Bredella, Miriam A.; Klibanski, Anne

2014-01-01

Context: Data suggest that anorexia nervosa (AN) and obesity are complicated by elevated fracture risk, but skeletal site-specific data are lacking. Traditional bone mineral density (BMD) measurements are unsatisfactory at both weight extremes. Hip structural analysis (HSA) uses dual-energy X-ray absorptiometry data to estimate hip geometry and femoral strength. Factor of risk (φ) is the ratio of force applied to the hip from a fall with respect to femoral strength; higher values indicate higher hip fracture risk. Objective: The objective of the study was to investigate hip fracture risk in AN and overweight/obese women. Design: This was a cross-sectional study. Setting: The study was conducted at a Clinical Research Center. Patients: Patients included 368 women (aged 19–45 y): 246 AN, 53 overweight/obese, and 69 lean controls. Main Outcome Measures: HSA-derived femoral geometry, peak factor of risk for hip fracture, and factor of risk for hip fracture attenuated by trochanteric soft tissue (φattenuated) were measured. Results: Most HSA-derived parameters were impaired in AN and superior in obese/overweight women vs controls at the narrow neck, intertrochanteric, and femoral shaft (P ≤ .03). The φattenuated was highest in AN and lowest in overweight/obese women (P < .0001). Lean mass was associated with superior, and duration of amenorrhea with inferior, HSA-derived parameters and φattenuated (P < .05). Mean φattenuated (P = .036), but not femoral neck BMD or HSA-estimated geometry, was impaired in women who had experienced fragility fractures. Conclusions: Femoral geometry by HSA, hip BMD, and factor of risk for hip fracture attenuated by soft tissue are impaired in AN and superior in obesity, suggesting higher and lower hip fracture risk, respectively. Only attenuated factor of risk was associated with fragility fracture prevalence, suggesting that variability in soft tissue padding may help explain site-specific fracture risk not captured by BMD. PMID:25062461

A protocol for treatment of unstable ankle fractures using transarticular fixation in patients with diabetes mellitus and loss of protective sensibility.

PubMed

Jani, Mihir M; Ricci, William M; Borrelli, Joseph; Barrett, Susan E; Johnson, Jeffrey E

2003-11-01

Surgical treatment of ankle fractures in patients with diabetes mellitus is associated with a high complication rate. Diabetic patients with peripheral neuropathy are a particularly difficult group to treat because of their inability to sense deep infection, repeat trauma, and wound complications. The purpose of this study was to evaluate a protocol that included transarticular fixation and prolonged, protected weightbearing in the treatment of unstable ankle fractures in diabetic patients with peripheral neuropathy and loss of protective sensibility. The authors retrospectively reviewed the records of 15 patients with diabetes mellitus, unstable ankle fractures (AO classification 44B), and loss of protective sensibility confirmed via testing with a 5.07 Semmes-Weinstein monofilament. Retrograde transcalcaneal-talar-tibial fixation using large Steinmann pins or screws in conjunction with standard techniques of open reduction and internal fixation was used. The postoperative treatment protocol included: 1) short leg, total contact casting and nonweightbearing status for 12 weeks; 2) removal of the intramedullary implants between 12 and 16 weeks; 3) application of a walker boot or short leg cast with partial weightbearing for an additional 12 weeks; and 4) transition to a custom-molded ankle-foot orthosis (AFO) or custom total-contact inserts in appropriate diabetic footwear. The major complication rate for all fractures was 25% (4/16) and for closed fractures was 23% (3/13). These are lower than previously reported rates between 30% (3/10) and 43% (9/21) for diabetic patients with and without neuropathy. The amputation rate for all fractures was 13% (2/16) and for closed fractures alone was 8% (1/13). These are similar to previously reported rates of 10% (2/10) to 20% (2/21). There were no deaths or Charcot malunions in this series. The combination of transarticular fixation and prolonged, protected weightbearing provided 13 of 15 patients with a stable ankle for weightbearing. Although these fractures remain a treatment challenge, this study presents a successful, multidisciplinary protocol for treatment of unstable ankle fractures in the most challenging group of diabetic patients - those with loss of protective sensibility.

[Percutaneous treatment of unstable spine fractures - OP video and results from over 300 cases].

PubMed

Prokop, A; Chmielnicki, M

2014-02-01

Minimally invasive surgery for vertebral fractures results in less approach-related morbidity, decreased postoperative pain, and rapid mobilisation of patients. Such procedures can be performed even in elderly patients. However, along with the many advantages, minimally invasive procedures are technically demanding, require sophisticated tools, and there is a learning curve for surgeons. Intraoperative visualisation is often possible only radiologically, and implants are generally much more expensive. Using the data from over 300 unstable vertebral fracture cases treated over the past 3.5 years, we have developed a differentiated treatment concept, depending on the age of the patient and the fracture characteristics. Unstable fractures with involvement of the posterior edge are stabilised from posterior, percutaneously with a fixator. In patients under 60 years, monoaxial screws with inserted rods (top loading) are used, with which distraction and restoration of lordosis are also possible. Patients over 60 years are treated percutaneously with a polyaxial sextant system with rods inserted to avoid avulsion of the pedicle screws from the vertebral body. To avoid cutting through the vertebra, the fenestrated screws can be augmented with cement. The operation technique is demonstrated by a video. Georg Thieme Verlag KG Stuttgart · New York.

Texture analysis of clinical radiographs using radon transform on a local scale for differentiation between post-menopausal women with and without hip fracture

NASA Astrophysics Data System (ADS)

Boehm, Holger F.; Körner, Markus; Baumert, Bernhard; Linsenmaier, Ulrich; Reiser, Maximilian

2011-03-01

Osteoporosis is a chronic condition characterized by demineralization and destruction of bone tissue. Fractures associated with the disease are becoming an increasingly relevant issue for public health institutions. Prediction of fracture risk is a major focus research and, over the years, has been approched by various methods. Still, bone mineral density (BMD) obtained by dual-energy X-ray absorptiometry (DXA) remains the clinical gold-standard for diagnosis and follow-up of osteoporosis. However, DXA is restricted to specialized diagnostic centers and there exists considerable overlap in BMD results between populations of individuals with and without fractures. Clinically far more available than DXA is conventional x-ray imaging depicting trabecular bone structure in great detail. In this paper, we demonstrate that bone structure depicted by clinical radiographs can be analysed quantitatively by parameters obtained from the Radon Transform (RT). RT is a global analysis-tool for detection of predefined, parameterized patterns, e.g. straight lines or struts, representing suitable approximations of trabecular bone texture. The proposed algorithm differentiates between patients with and without fractures of the hip by application of various texture-metrics based on the Radon-Transform to standard x-ray images of the proximal femur. We consider three different regions-of-interest in the proximal femur (femoral head, neck, and inter-trochanteric area), and conduct an analysis with respect to correct classification of the fracture status. Performance of the novel approach is compared to DXA. We draw the conclusion that performance of RT is comparable to DXA and may become a useful supplement to densitometry for the prediction of fracture risk.

Coupled Modeling of Flow, Transport, and Deformation during Hydrodynamically Unstable Displacement in Fractured Rocks

NASA Astrophysics Data System (ADS)

Jha, B.; Juanes, R.

2015-12-01

Coupled processes of flow, transport, and deformation are important during production of hydrocarbons from oil and gas reservoirs. Effective design and implementation of enhanced recovery techniques such as miscible gas flooding and hydraulic fracturing requires modeling and simulation of these coupled proceses in geologic porous media. We develop a computational framework to model the coupled processes of flow, transport, and deformation in heterogeneous fractured rock. We show that the hydrocarbon recovery efficiency during unstable displacement of a more viscous oil with a less viscous fluid in a fractured medium depends on the mechanical state of the medium, which evolves due to permeability alteration within and around fractures. We show that fully accounting for the coupling between the physical processes results in estimates of the recovery efficiency in agreement with observations in field and lab experiments.

[Low incidence of hip fractures among the elderly in Guadeloupe: a spared Caribbean island population].

PubMed

Naudi, S; Mehdi, N; Gatti, S; Stroppa, S; Fleurat, E

2007-02-01

The purpose of this study was to determine the incidence of hip fractures among the elderly population in Guadeloupe, a French Caribbean archipelago with 440,000 inhabitants who present two rarely associated characteristics: 90% of the population is of African descent and life expectancy is similar to that of European populations. Using the recent census report, we established that in 2002, 61,000 persons aged 60 years or more (27,000 men and 34,000 women) lived in Guadeloupe. All new cases of hip fracture among the population aged 60 years or more were recorded in 2002, 2003, and 2004 in the seven islands that compose Guadeloupe. For each case, we noted patient age and gender, type of hip fracture, and treatment administered. We excluded open and pathologic fractures. Overall and age-specific incidence of hip fractures were determined and compared with rates reported for other countries. Three hundred and two new cases of hip fracture were recorded from 2002 to 2005 in 211 women (70%) and 91 men (30%). The age of patients was 82 years on average (range 60-102). There were 134 neck fractures and 168 intertrochanteric fractures which were treated by osteosynthesis for 193 and arthroplasty for 108. Only one orthopedic treatment was noted. The incidence of hip fracture for people aged over 60 years was 16.9/10,000; for the population aged 65 years or more, it was 22.2/10,000. Osteoporotic fracture is a pandemic problem. Incidence is increasing worldwide. Our findings demonstrate that Guadeloupeans are spared from this pathology. This population offers an interesting field for research into the causal mechanisms of osteoporotic fractures and potential means of prevention or screening. The incidence of hip fractures among the elderly population in Guadeloupe is the lowest recorded in the world. We suggest that an environmental and genetic study in this spared population could provide interesting insight into the cause of hip fractures and appropriate means of prevention and screening among the elderly. The geographic and environmental characteristics of Guadeloupe make this area a unique zone of research and should enable new insight into the genetic and environmental factors involved in hip fractures.

Computed tomography for occult fractures of the proximal femur, pelvis, and sacrum in clinical practice: single institution, dual-site experience.

PubMed

Mandell, Jacob C; Weaver, Michael J; Khurana, Bharti

2018-06-01

The purpose of this study was to evaluate the diagnostic performance of CT for assessment of occult fractures of the proximal femur, pelvis, and sacrum. A retrospective review was performed on patients who received a CT of the hip or pelvis for suspected occult fracture after negative or equivocal radiographs performed within 24 h. The official radiology report was utilized for the determination of CT findings and calculation of sensitivity and specificity. Surgical reports, MRI reports, and clinical follow-up were used as the standard of reference. Sensitivity and specificity were calculated with 95% confidence intervals. Seventy-four patients received CT of the hip or pelvis for clinical concern for occult fracture after negative or equivocal radiographs. By the reference standard, a total of 40 fractures were present in 25/74 (33.8%) patients, including 35 conservatively treated fractures of the greater trochanter, pelvis, and sacrum, and 5 operatively treated proximal femoral fractures. A total of 14/74 (18.9%) of patients had an MRI within 1 day of CT. MRI identified an operatively treated femoral neck fracture not seen on CT and an operatively treated intertrochanteric fracture, which CT described as a greater trochanteric fracture. There were two false negative conservatively treated pelvic fractures not seen on CT but diagnosed on MRI. On a per-patient basis, CT had an overall sensitivity of 88% (22/25; 95% confidence intervals 69-97%), specificity of 98% (48/49; 95% confidence intervals 89-100%), and negative predictive value of 94%. For the five operative proximal femoral fractures, the sensitivity of CT was 60% (3/5; 95% confidence intervals 15-95%), specificity was 99% (68/69; 95% confidence intervals 92-100%), and negative predictive value was 97%. In the clinical setting of suspected occult fracture, the sensitivity of clinical CT reports for detection of any type of fracture of the proximal femur, pelvis, or sacrum was 88%. For the small number of operatively treated proximal femoral fractures seen in the study, sensitivity of CT was 60% (3/5) and negative predictive value was 97%, although the relatively few patients needing fixation precludes statistical analysis.

Reassessment of osteoporosis-related femoral fractures and economic burden in Saudi Arabia.

PubMed

Sadat-Ali, Mir; Al-Dakheel, Dakheel A; Azam, Md Q; Al-Bluwi, Mohammed T; Al-Farhan, Mohammed F; AlAmer, Hussein A; Al-Meer, Zakaria; Al-Mohimeed, Abdallah; Tabash, Ibrahim K; Karry, Maher O; Rassasy, Yaseen M; Baragaba, Mohammed A; Amer, Ahmed S; AlJawder, Abdallah; Al-Bouri, Kamil M; ElTinay, Mohammed; Badawi, Hamed A; Al-Othman, Abdallah A; Tayara, Badar K; Al-Faraidy, Moaad H; Amin, Ahmed H

2015-01-01

The current study reassesses the prevalence of fragility fractures and lifetime costs in the Eastern Province of Saudi Arabia. Forty-two percent (391) of the fractures were at the neck of the femur, and 38.6 % (354) were inter-trochanteric fractures. The overall incidence was assessed to be 7528 (1,300,336 population 55 years or older) with the direct cost of SR564.75 million ($150.60 million). A National Fracture Registry and osteoporosis awareness programs are recommended. Proximal femur fragility fractures are reported to be increasing worldwide due to increased life expectancy. The current study is carried out to assess the incidence of such fractures in the Eastern Province of Saudi Arabia and to assess the costs incurred in managing them annually. Finally, by extrapolating the data, the study can calculate the overall economic burden in Saudi Arabia. The data of fragility proximal femur fractures was collected from 24 of 28 hospitals in the Eastern Province. The data included age, sex, mode of injury, type of fracture, prescribed drug (and its cost), and length of hospital stay. Population statistics were obtained from the Department of Statistics of the Saudi Arabian government Web site. Twenty-four hospitals (85 %) participated in the study. A total of 780 fractures were sustained by 681 patients. Length of stay in the hospital averaged 23.28 ± 13.08 days. The projected fracture rate from all the hospitals would be 917 (an incidence of 5.81/1000), with a total cost of SR68.77 million. Further extrapolation showed that the overall incidence could be 7528 (1,300,336 population 55 years or older) with the direct cost of SR564.75 million ($150.60 million). Osteoporosis-related femoral fractures in Saudi Arabia are significant causes of morbidity besides incurring economic burden. We believe that a National Fracture Registry needs to be established, and osteoporosis awareness programs should be instituted in every part of Saudi Arabia so that these patients can be diagnosed early and treated appropriately to reduce both the number of fractures and the economic burden of the fractures.

Management of unstable distal third clavicle fractures: clinical and radiological outcomes of the arthroscopy-assisted conoid ligament reconstruction and fracture cerclage with sutures.

PubMed

Cisneros, Luis Natera; Reiriz, Juan Sarasquete

2017-04-01

Surgical treatment is indicated for the management of Neer type IIB fractures of the distal third of the clavicle. The aim of this study was to assess the clinical and radiological outcomes, in cases of unstable distal third clavicle fractures managed by means of an arthroscopy-assisted conoid ligament reconstruction and fracture cerclage with sutures. Nine patients with unstable distal third clavicle fractures (Neer type IIB) managed arthroscopically by means of a conoid ligament reconstruction and fracture cerclage with sutures, between 2008 and 2012, were included. The QoL was evaluated at the last follow-up visit, by means of the Health Survey questionnaire (SF36), the visual analogue scale (VAS) for pain, the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, the constant score, and a Global Satisfaction scale (from 0 to 10). The mean time from fracture fixation until radiological union, the development of hardware loosening, nonunion, infections, and hardware skin discomfort were evaluated. The mean age was 36 [21-48] years old. The mean [range] time from surgery until the last follow-up visit was 49 [46-52] months. Values of the questionnaires assessed at the last follow-up visit were: (1) physical SF36 score (50.72 ± 6.88); (2) mental SF36 score (50.92 ± 11.65); (3) VAS for pain (1.86 ± 1.35); (4) DASH questionnaire (11.97 ± 7.03); (5) constant score (89.67 ± 8.55), and (6) Global Satisfaction (8.17 ± 0.98). The mean time elapsed from fracture fixation to radiological union was 8.41 ± 3.26 months. Hardware loosening was observed in none of the patients. Nonunion was observed in 11.11% (1/9) of the patients. Hardware skin discomfort was observed in 11.11% (1/9) of the patients. Patients with unstable distal third clavicle fractures managed by means of an arthroscopy-assisted conoid ligament reconstruction and fracture cerclage with sutures may have good clinical and radiological outcomes, with no need for a second surgical procedure to remove any metal hardware. Therapeutic; case series, Level IV.

Treatment of unstable intraarticular fracture of distal radius: POP casting with external fixation.

PubMed

ur Rahman, Obaid; Khan, Mohammad Qadeem; Rasheed, Haroon; Ahmad, Saleem

2012-04-01

To compare radiological and functional outcome of external fixation and distraction with conservative Plaster of Paris (POP) cast for unstable intra-articular fractures of the distal radius. The study was conducted on 60 patients with unstable intra-articular fracture of distal radius who reported to emergency or outpatient Orthopaedic Surgery department of Benazir Bhutto Hospital, Rawalpindi, between March and August 2007. They were divided into two equal groups: Group A and Group B, treated by Plaster of Paris cast, and external fixation with distraction respectively. The functional outcome in terms of freedom from pain, range of movement, grip power and deformity, and the radiological outcome of radial length, incongruity and radio-ulnar joint position were analysed at three months follow-up using a 3-point scoring scale. In Group A, 1 (3%) patient showed excellent result, 8 (27%) patients good results, 19 (63%) patients fair results and 2 (7%) patients poor result. In Group B, 14 (47%) patients showed excellent results, 11 (37%) patients good results, 4 (13%) patients fair results and 1 (3%) patient poor result. The outcome score of the Group B patients was significantly better compared to the Group A patients (p value < 0.05). External fixation has definite advantages over conventional Plaster of Paris cast in the treatment of unstable intra-articular fractures of distal radius.

Analysis of the Postoperative Displacement of Trochanteric Fractures on Lateral View Radiographs.

PubMed

Furui, Atsuo; Terada, Nobuki

2017-08-01

Achieving sufficient support of the anterior cortex of the femoral neck is a fundamental goal of the reduction of trochanteric fractures. However, anterior-cortex support is often lost after the fracture reduction. Our aim was to analyze factors contributing to the postoperative displacement of an acceptably reduced trochanteric fracture. The cases of 40 patients with a post-reduction Ikuta subtype N fracture alignment were reviewed. All fractures were fixed with 135° free-sliding plates. On postoperative day 14, patients were classified into two groups: those with retention of the Ikuta subtype N alignment, and those with progression to Ikuta subtype P alignment. The clinical and radiological factors were evaluated between the groups. In addition, to define one of the factors, i.e., the postoperative rotational displacement between the proximal and distal fragments, the relationship between radiographic findings and computed tomography image measurements was assessed in 15 of the 40 patients. Angulation at the fracture site on lateral view radiographs was defined as postoperative rotational displacement, and unstable trochanteric fractures and postoperative rotational displacement were identified as significant risk factors for the postoperative displacement. Therefore, cautious and careful follow-up is warranted for patients with unstable trochanteric fractures or fractures having rotational displacement.

Unstable metacarpal and phalangeal fractures: treatment by internal fixation using AO mini-fragment plates and screws.

PubMed

Mumtaz, Mohammad Umar; Farooq, Muneer Ahmad; Rasool, Altaf Ahmad; Kawoosa, Altaf Ahmad; Badoo, Abdul Rashid; Dhar, Shabir Ahmad

2010-07-01

Accurate open reduction and internal fixation for metacarpal and phalangeal fractures of the hand is required in less than 5% of the patients; otherwise, closed treatment techniques offer satisfactory results in most of these cases as these fractures are stable either before or after closed reduction. AO mini-fragment screws and plates, when used in properly selected cases, can provide rigid fixation, allowing early mobilization of joints and hence good functional results while avoiding problems associated with protruding K-wires and immobilization. The advantages of such internal fixation urged us to undertake such a study in our state where such hand injuries are commonly seen. Forty patients with 42 unstable metacarpal and phalangeal fractures were treated with open reduction and internal fixation using AO mini-fragment screws and plates over a period of three years in a prospective manner. The overall results were good in 78.5% of cases, fair in 19% of cases and poor in 2.5% of cases, as judged according to the criteria of the American Society for Surgery of the Hand. This technique is a reasonable option for treating unstable metacarpal and phalangeal fractures as it provides a highly rigid fixation, which is sufficient to allow early mobilization of the adjacent joints, thus helping to achieve good functional results.

Effects of trochanteric soft tissue thickness and hip impact velocity on hip fracture in sideways fall through 3D finite element simulations.

PubMed

Majumder, Santanu; Roychowdhury, Amit; Pal, Subrata

2008-09-18

A major worldwide health problem is hip fracture due to sideways fall among the elderly population. The effects of sideways fall on the hip are required to be investigated thoroughly. The objectives of this study are to evaluate the responses to trochanteric soft tissue thickness (T) variations and hip impact velocity (V) variations during sideways fall based on a previously developed CT scan derived 3D non-linear and non-homogeneous finite element model of pelvis-femur-soft tissue complex with simplified biomechanical representation of the whole body. This study is also aimed at quantifying the effects [peak impact force (F(max)), time to F(max), acceleration and peak principal compressive strain (epsilon(max))] of these variations (T,V) on hip fracture. It was found that under constant impact energy, for 81% decrease in T (26-5mm), F(max) and epsilon(max) increased by 38% and 97%, respectively. Hence, decrease in T (as in slimmer persons) strongly correlated to risk for hip fracture (phi) and strain ratio (SR) by 0.972 and 0.988, respectively. Also under same T and body weight, for 75% decrease in V (4.79-1.2m/s), F(max) and epsilon(max) decreased by 70% and 86%, respectively. Hence, increase in V (as in taller persons) strongly correlated to phi and SR by 0.995 and 0.984, respectively. For both variations in T and V, inter-trochanteric fracture situations were well demonstrated by phi as well as by SR and strain contours, similar to clinically observed fractures. These quantifications would be helpful for effective design of person-specific hip protective devices.

The effects of once-weekly teriparatide on hip geometry assessed by hip structural analysis in postmenopausal osteoporotic women with high fracture risk.

PubMed

Sone, Teruki; Ito, Masako; Fukunaga, Masao; Tomomitsu, Tatsushi; Sugimoto, Toshitsugu; Shiraki, Masataka; Yoshimura, Takeshi; Nakamura, Toshitaka

2014-07-01

Weekly administration of teriparatide has been shown to reduce the risk of vertebral and non-vertebral fractures in patients with osteoporosis at higher fracture risk in Japan. However, its efficacy for hip fracture has not been established. To gain insight into the effect of weekly teriparatide on the hip, hip structural analysis (HSA) based on dual-energy X-ray absorptiometry (DXA) was performed using the data of 209 postmenopausal osteoporotic women who had participated in the original randomized, multicenter, double-blind, placebo-controlled trial assessing the effects of once-weekly 56.5 μg teriparatide for 72 weeks. The DXA scans, obtained at baseline, 48 weeks and 72 weeks, were analyzed to extract bone mineral density (BMD) and cross-sectional geometrical indices at the narrowest point on the neck (NN), the intertrochanteric region (IT), and the proximal shaft. Compared with placebo after 72 weeks, the teriparatide group showed significantly higher BMD, average cortical thickness, bone cross-sectional area, and section modulus, and lower buckling ratio at both the NN and IT regions. No significant expansion of periosteal diameter was observed at these regions. There were no significant differences in BMD and HSA indices at the shaft region. The results indicate that overall structural strength in the proximal femur increased compared to placebo, suggesting that once-weekly teriparatide effectively reverses changes in hip geometry and strength with aging. Copyright © 2014. Published by Elsevier Inc.

The stability of a hip fracture determines the fatigue of an intramedullary nail.

PubMed

Eberle, S; Bauer, C; Gerber, C; von Oldenburg, G; Augat, P

2010-01-01

The purpose of this study was to address the question of how the stability of a proximal hip fracture determines the fatigue and failure mechanism of an intramedullary implant. To answer this question, mechanical experiments and finite element simulations with two different loading scenarios were conducted. The two load scenarios differed in the mechanical support of the fracture by an artificial bone sleeve, representing the femoral head and neck. The experiments confirmed that an intramedullary nail fails at a lower load in an unstable fracture situation in the proximal femur than in a stable fracture. The nails with an unstable support failed at a load 28 per cent lower than the nails with a stable support by the femoral neck. Hence, the mechanical support of a fracture is crucial to the fatigue failure of an implant. The simulation showed why the fatigue fracture of the nail starts at the aperture of the lag screw. It is the location of the highest von Mises stress, which is the failure criterion for ductile materials.

[Distal clavicle fracture].

PubMed

Seppel, G; Lenich, A; Imhoff, A B

2014-06-01

Reposition and fixation of unstable distal clavicle fractures with a low profile locking plate (Acumed, Hempshire, UK) in conjunction with a button/suture augmentation cerclage (DogBone/FibreTape, Arthrex, Naples, FL, USA). Unstable fractures of the distal clavicle (Jäger and Breitner IIA) in adults. Unstable fractures of the distal clavicle (Jäger and Breitner IV) in children. Distal clavicle fractures (Jäger and Breitner I, IIB or III) with marked dislocation, injury of nerves and vessels, or high functional demand. Patients in poor general condition. Fractures of the distal clavicle (Jäger and Breitner I, IIB or III) without marked dislocation or vertical instability. Local soft-tissue infection. Combination procedure: Initially the lateral part of the clavicle is exposed by a 4 cm skin incision. After reduction of the fracture, stabilization is performed with a low profile locking distal clavicle plate. Using a special guiding device, a transclavicular-transcoracoidal hole is drilled under arthroscopic view. Additional vertical stabilization is arthroscopically achieved by shuttling the DogBone/FibreTape cerclage from the lateral portal cranially through the clavicular plate. The two ends of the FibreTape cerclage are brought cranially via adjacent holes of the locking plate while the DogBone button is placed under the coracoid process. Thus, plate bridging is achieved. Finally reduction is performed and the cerclage is secured by surgical knotting. Use of an arm sling for 6 weeks. Due to the fact that the described technique is a relatively new procedure, long-term results are lacking. In the short term, patients postoperatively report high subjective satisfaction without persistent pain.

Study of the X-Ray Diagnosis of Unstable Pelvic Fracture Displacements in Three-Dimensional Space and its Application in Closed Reduction.

PubMed

Shi, Chengdi; Cai, Leyi; Hu, Wei; Sun, Junying

2017-09-19

ABSTRACTS Objective: To study the method of X-ray diagnosis of unstable pelvic fractures displaced in three-dimensional (3D) space and its clinical application in closed reduction. Five models of hemipelvic displacement were made in an adult pelvic specimen. Anteroposterior radiographs of the pelvis were analyzed in PACS. The method of X-ray diagnosis was applied in closed reductions. From February 2012 to June 2016, 23 patients (15 men, 8 women; mean age, 43.4 years) with unstable pelvic fractures were included. All patients were treated by closed reduction and percutaneous cannulate screw fixation of the pelvic ring. According to Tile's classification, the patients were classified into type B1 in 7 cases, B2 in 3, B3 in 3, C1 in 5, C2 in 3, and C3 in 2. The operation time and intraoperative blood loss were recorded. Postoperative images were evaluated by Matta radiographic standards. Five models of displacement were made successfully. The X-ray features of the models were analyzed. For clinical patients, the average operation time was 44.8 min (range, 20-90 min) and the average intraoperative blood loss was 35.7 (range, 20-100) mL. According to the Matta standards, 7 cases were excellent, 12 cases were good, and 4 were fair. The displacements in 3D space of unstable pelvic fractures can be diagnosed rapidly by X-ray analysis to guide closed reduction, with a satisfactory clinical outcome.

Pseudogout at the knee joint will frequently occur after hip fracture and lead to the knee pain in the early postoperative period.

PubMed

Harato, Kengo; Yoshida, Hiroki

2015-01-14

Symptomatic knee joint effusion is frequently observed after hip fracture, which may lead to postoperative knee pain during rehabilitation after hip fracture surgery. However, unfortunately, very little has been reported on this phenomenon in the literature. The purpose of the current study was to investigate the relationship between symptomatic knee effusion and postoperative knee pain and to clarify the reason of the effusion accompanied by hip fracture. A total of 100 patients over 65 years of age with an acute hip fracture after fall were prospectively followed up. Knee effusion was assessed on admission and at the operating room before the surgery. If knee effusion was observed at the time of the surgery, synovial fluid was collected into syringes to investigate the cause of the effusion using a compensated polarized light microscope. Furthermore, for each patient, we evaluated age, sex, radiographic knee osteoarthritis (OA), type of the fracture, laterality, severity of the fracture, and postoperative knee pain during rehabilitation. These factors were compared between patients with and without knee effusion at the time of the surgery. As a statistical analysis, we used Mann-Whitney U-test for patients' age and categorical variables were analyzed by chi-square test or Fisher's exact test. A total of 30 patients presented symptomatic knee effusion at the time of the surgery. In patients with knee effusion, numbers of intertrochanteric fracture, radiographic knee OA, and postoperative knee pain were significantly large compared to those without effusion. In terms of synovial fluid analysis, calcium pyrophosphate dihydrate crystals were observed in 80% of patients with knee effusion. From our study, approximately 63% of patients with knee effusion at the time of the surgery had postoperative knee pain. In addition, this effusion was basically related to pseudogout.

The effects of different nutritional measurements on delayed wound healing after hip fracture in the elderly.

PubMed

Guo, Jiong Jiong; Yang, Huilin; Qian, Haixin; Huang, Lixin; Guo, Zhongxing; Tang, Tiansi

2010-03-01

It has been well recognized that malnutrition causes wounds to heal inadequately and incompletely. Malnutrition is often observed in the elderly, and it appears to be more severe in patients with hip fracture than in the general aging population. Few prospective studies give a detailed account of the identification and classification of nutritional status in the elderly. The objective of this study was to evaluate the effects of different nutritional measurements on wound healing status after hip fracture in the elderly. From September 2002 to December 2007, 207 hip fracture patients older than 60 y treated surgically were reviewed for preoperative nutritional status. There were 81 males and 126 females with an average age of 75.93 y (62-91 y); 131 cases with femoral neck fractures, 76 cases with intertrochanteric fractures. Parameters indicative of nutritional status (serum albumin, serum transferrin, serum pre-albumin, and total lymphocyte count levels) at the time of admission were assessed, along with anthropometric measurements, Rainey MacDonald nutritional index, and MNA tool. Suture removal was performed on postoperative day 14. Delayed wound healing complicated 46 (22.2%) of the 207 cases. The preoperative serum transferring total lymphocyte count levels, MNA total score, and Rainey MacDonald nutritional index were significantly lower for patients who subsequently had delayed wound healing. When all variables were subjected to multivariate analysis, only total lymphocyte count levels and MNA total score showed significant value in predicting which patients would have delayed wound healing. Through prophylactic antibiotics and adherence to strict aseptic precautions, on follow-up, wound healing was normal in all patients. Patients at risk for delayed wound healing problems after hip fracture can be identified using relatively inexpensive laboratory test such as TLC and MNA tool. The clinician must be aware of the risk values of both measurements. We believe this information is particularly important before planning procedures of hip fractures in the elderly. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Arthroscopic-assisted Locking Compression Plate clavicular hook fixation for unstable fractures of the lateral end of the clavicle: a prospective study

PubMed Central

Lee, Kwang Won; Kim, Kap Jung; Kim, Yong In; Kwon, Won Cho; Choy, Won Sik

2009-01-01

The aim of this prospective study was to assess the clinical outcomes of an unstable fracture of the lateral end of the clavicle treated with an arthroscopic-assisted locking compressive plate (LCP) clavicular hook plate. Twenty-three patients underwent arthroscopic assisted LCP clavicular hook plate fixation for these fractures. All patients achieved clinical and radiological union over a mean of 4.2 months (range, 3.4–5 months). Four patients (17%) showed some degree of acromial osteolysis. Three patients (13%) showed radiological signs of arthrosis of the acromioclavicular joint. In one patient, a second fracture (stress) was observed between the medial two screws of the plate without an additional injury. Five patients (22%) showed subacromial bursitis on dynamic ultrasonography. The mean Constant and Murley score was 91 points (range, 81–98). The average level of pain in the shoulder at rest and on abduction was 1 (range, 0–2) and 2.4 (range, 0–4), respectively. Based on our experience, arthroscopic-assisted LCP hook plate fixation for the treatment of unstable fractures of the lateral end of the clavicle is not without complications. However, it is an acceptable alternative method that is easy to apply with good results. Furthermore, it prevents rotator cuff impingement, allows early mobilisation and maintains the acromioclavicular joint biomechanics. PMID:19998033

Treatment of unstable distal radius fractures with Ilizarov circular, nonbridging external fixator.

PubMed

Tyllianakis, Minos; Mylonas, Spyros; Saridis, Alkis; Kallivokas, Alkiviadis; Kouzelis, Antonis; Megas, Panagiotis

2010-03-01

Unstable distal radius fractures remain a challenge for the treating orthopaedic surgeon. We present a retrospective follow-up study (mean follow-up 12.5 months) of 20 patients with 21 unstable distal radius fractures that were reduced in a closed manner and stabilized with a nonbridging Ilizarov external fixator. Subsequent insertion of olive wires for interfragmentary compression was performed in cases with intra-articular fractures. According to the overall evaluation proposed by Gartland and Werley scoring system 12 wrists were classified as excellent, 6 as good, 2 as fair and 1 as poor. Grade II pin-tract infection in distal fracture fragment was detected in 3 wires from a total of 78 (3.8%) and in 4 half pins out of a total of 9 (44.4%). Pronation was the most frequently impaired movement. This was restricted in 4 patients (19%) in whom a radioulnar transfixing wire was applied. Symptoms of irritation of superficial sensory branch of the radial nerve occurred in 3 patients with an olive wire applied in a closed manner in the distal fragment. Ilizarov method yields functional results comparable to that of other methods whilst it avoids wrist immobilization, open reduction and reoperation for implant removal. The method is associated with a low rate of major complication and satisfactory functional outcome. Copyright 2009 Elsevier Ltd. All rights reserved.

[Direct osteosynthesis of instable Gehweiler Type III atlas fractures. Presentation of a dorsoventral osteosynthesis of instable atlas fractures while maintaining function].

PubMed

Böhm, H; Kayser, R; El Saghir, H; Heyde, C-E

2006-09-01

This retrospective study evaluates eight patients with unstable fractures of the atlas vertebra, treated operatively in the Central Clinic Bad Berka between January 1995 and December 2001. In all cases, we were confronted with unstable and dislocated type III fractures according to Gehweiler, caused by an injured transverse ligament. Mean age was 34 years (range 20-49) in two women and six men. We introduce a new technique of direct reconstruction of the atlas vertebra. This technique leads to a stable ring construct that allows compression osteosynthesis of the fracture. Spinal fusion can be avoided, as can postoperative immobilization, since sufficient stability for functional postoperative treatment is achievable. The follow-up control 38 months (range 6-75) after surgery showed solid bony fusion in all cases, in one case after revision surgery. All patients showed good functional results, there was no need for analgesics and all patients could be reintegrated into their former occupation.

Integration of ambient seismic noise monitoring, displacement and meteorological measurements to infer the temperature-controlled long-term evolution of a complex prone-to-fall cliff

NASA Astrophysics Data System (ADS)

Colombero, C.; Baillet, L.; Comina, C.; Jongmans, D.; Larose, E.; Valentin, J.; Vinciguerra, S.

2018-06-01

Monitoring the temporal evolution of resonance frequencies and velocity changes detected from ambient seismic noise recordings can help in recognizing reversible and irreversible modifications within unstable rock volumes. With this aim, the long-term ambient seismic noise data set acquired at the potentially unstable cliff of Madonna delSasso (NW Italian Alps) was analysed in this study, using both spectral analysis and cross-correlation techniques. Noise results were integrated and compared with direct displacement measurements and meteorological data, to understand the long-term evolution of the cliff. No irreversible modifications in the stability of the site were detected over the monitored period. Conversely, daily and seasonal air temperature fluctuations were found to control resonance frequency values, amplitudes and directivities and to induce reversible velocity changes within the fractured rock mass. The immediate modification in the noise parameters due to temperature fluctuations was interpreted as the result of rock mass thermal expansion and contraction, inducing variations in the contact stiffness along the fractures isolating two unstable compartments. Differences with previous case studies were highlighted in the long-term evolution of noise spectral amplitudes and directivities, due to the complex 3-D fracture setting of the site and to the combined effects of the two unstable compartments.

Immediate percutaneous sacroiliac screw insertion for unstable pelvic fractures: is it safe enough?

PubMed

Acker, A; Perry, Z H; Blum, S; Shaked, G; Korngreen, A

2018-04-01

The purpose of this study was to compare the results of immediate and delayed percutaneous sacroiliac screws surgery for unstable pelvic fractures, regarding technical results and complication rate. Retrospective study. The study was conducted at the Soroka University Medical center, Beer Sheva, Israel, which is a level 1 trauma Center. 108 patients with unstable pelvic injuries were operated by the orthopedic department at the Soroka University Medical Center between the years 1999-2010. A retrospective analysis found 50 patients with immediate surgery and 58 patients with delayed surgery. Preoperative and postoperative imaging were analyzed and data was collected regarding complications. All patients were operated on by using the same technique-percutaneous fixation of sacroiliac joint with cannulated screws. The study's primary outcome measure was the safety and quality of the early operation in comparison with the late operation. A total of 156 sacroiliac screws were inserted. No differences were found between the immediate and delayed treatment groups regarding technical outcome measures (P value = 0.44) and complication rate (P value = 0.42). The current study demonstrated that immediate percutaneous sacroiliac screw insertion for unstable pelvic fractures produced equally good technical results, in comparison with the conventional delayed operation, without additional complications.

[A new type sternoclavicular hook plate for unstable sternoclavicular joint dislocation and fracture].

PubMed

Zhang, Chuan-Yi; Lin, Lie; Liang, Jun-Bo; Wang, Bin; Chen, Guo-Fu; Chen, Hai-Xiao

2016-11-25

To evaluate the therapeutic effect of a new type sternoclavicular hook plate fixation in treating unstable sternoclavicular joint dislocation and fracture. From June 2011 to December 2013, 32 patients with sternoclavicular joint dislocation and fracture were treated with a new type sternoclavicular hook plate fixation, including 24 males and 8 females with an average age of 42 years ranging from 25 to 76 years;12 patients were anterior dislocation, 5 pations were posterior dislocation, 10 patients were internal extremity of clavicle fracture and 5 patients were sternoclavicular joint dislocation combined with fracture. The anterior fracture dislocation of the sternoclavicular joint adopted standard sternoclavicular joint hook plate, and the posterior dislocation was at the distal end of the hook of the steel plate, that is, the front part of the handle of the breast was added with a nut and a gasket to prevent the re-dislocation after operation. The results were evaluated according to Rockwood score. No complication happened in all patients. X-ray and CT showed that the dislocation and fracture of the sternoclavicular joint was well reduced and the plate was on right position. All patients were followed up for 6 to 24 months with an average of 10 months. At 6 to 3 months after operation, the fracture was healing without re-dislocation of the sternoclavicular joint, the medial end of the clavicle anatomical structure were restored, functional satisfaction, in which 9 patients with the swelling around sternoclavicular joint, but no pain and other symptoms. The total Rockwood score was 12.78±1.43; the results were excellent in 24 cases, good in 8 cases. The use of the new type of locking hook plate for the treatment of unstable fracture of the sternoclavicular joint, internal fixation is reliable, high security, easy to operate, to provide a reliable method for the treatment of such trauma.

Weight-bearing recommendations after operative fracture treatment-fact or fiction? Gait results with and feasibility of a dynamic, continuous pedobarography insole.

PubMed

Braun, Benedikt J; Veith, Nils T; Rollmann, Mika; Orth, Marcel; Fritz, Tobias; Herath, Steven C; Holstein, Jörg H; Pohlemann, Tim

2017-08-01

Rehabilitation after lower-extremity fractures is based on the physicians' recommendation for non-, partial-, or full weight-bearing. Clinical studies rely on this assumption, but continuous compliance or objective loading rates are unknown. The purpose of this study was to determine the compliance to weight-bearing recommendations by introducing a novel, pedobarography system continuously registering postoperative ground forces into ankle, tibial shaft and proximal femur fracture aftercare and test its feasibility for this purpose. In this prospective, observational study, a continuously measuring pedobarography insole was placed in the patients shoe during the immediate post-operative aftercare after ankle, tibial shaft and intertrochanteric femur fractures. Weight-bearing was ordered as per the institutional standard and controlled by physical therapy. The insole was retrieved after a maximum of six weeks (28 days [range 5-42 days]). Non-compliance was defined as a failure to maintain, or reach the ordered weight-bearing within 30%. Overall 30 patients were included in the study. Fourteen (47%) of the patients were compliant to the weight-bearing recommendations. Within two weeks after surgery patients deviated from the recommendation by over 50%. Sex, age and weight did not influence the performance (p > 0.05). Ankle fracture patients (partial weight-bearing) showed a significantly increased deviation from the recommendation (p = 0.01). Our study results show that, despite physical therapy training, weight-bearing compliance to recommended limits was low. Adherence to the partial weight-bearing task was further decreased over time. Uncontrolled weight-bearing recommendations should thus be viewed with caution and carefully considered as fiction. The presented insole is feasible to determine weight bearing continuously, could immediately help define real-time patient behaviour and establish realistic, individual weight-bearing recommendations.

Bone mineral density, osteoporosis, and fractures among people with eating disorders: a systematic review and meta-analysis.

PubMed

Solmi, M; Veronese, N; Correll, C U; Favaro, A; Santonastaso, P; Caregaro, L; Vancampfort, D; Luchini, C; De Hert, M; Stubbs, B

2016-05-01

To provide meta-analytical evidence of bone mineral density (BMD), fractures, and osteoporosis rates in eating disorders (ED) vs. healthy controls (HCs). Three independent authors searched major electronic databases from inception till August 2015 for cross-sectional studies reporting BMD in people with ED (anorexia nervosa, (AN); bulimia nervosa, (BN); eating disorders not otherwise specified, (EDNOS)) vs. HCs. Standardized mean differences (SMDs) ±95% and confidence intervals (CIs) were calculated for BMD, and odds ratios (ORs) for osteopenia, osteoporosis, and fractures. Overall, 57 studies were eligible, including 21 607 participants (ED = 6485, HCs = 15 122). Compared to HC, AN subjects had significantly lower BMD values at lumbar spine (SMD = -1.51, 95% CI = -1.75, -1.27, studies = 42), total hip (SMD = -1.56, 95%CI = -1.84, -1.28, studies = 23), intertrochanteric region (SMD = -1.80, 95%CI = -2.46, -1.14, studies = 7), trochanteric region (SMD = -1.05, 95%CI = -1.44, -0.66, studies = 7), and femoral neck (SMD = -0.98, 95%CI = -1.12, -0.77, studies = 20). Reduced BMD was moderated by ED illness duration and amenorrhea (P < 0.05). AN was associated with an increased likelihood of osteoporosis (OR = 12.59, 95%CI = 3.30-47.9, P < 0.001, studies = 4) and fractures (OR = 1.84, 95% CI = 1.17-2.89, I(2) = 56, studies = 6). No difference in BMD was found between BN and EDNOS vs. HC. People with AN have reduced BMD, increased odds of osteoporosis and risk of fractures. Proactive monitoring and interventions are required to ameliorate bone loss in AN. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Fluoroscopy-guided reduction and fibular nail fixation to manage unstable ankle fractures in patients with diabetes: a retrospective cohort study.

PubMed

Ashman, B D; Kong, C; Wing, K J; Penner, M J; Bugler, K E; White, T O; Younger, A S E

2016-09-01

Patients with diabetes are at increased risk of wound complications after open reduction and internal fixation of unstable ankle fractures. A fibular nail avoids large surgical incisions and allows anatomical reduction of the mortise. We retrospectively reviewed the results of fluoroscopy-guided reduction and percutaneous fibular nail fixation for unstable Weber type B or C fractures in 24 adult patients with type 1 or type 2 diabetes. The re-operation rate for wound dehiscence or other indications such as amputation, mortality and functional outcomes was determined. Two patients developed lateral side wound infection, one of whom underwent wound debridement. Three other patients required re-operation for removal of symptomatic hardware. No patient required a below-knee amputation. Six patients died during the study period for unrelated reasons. At a median follow-up of 12 months (7 to 38) the mean Short Form-36 Mental Component Score and Physical Component Score were 53.2 (95% confidence intervals (CI) 48.1 to 58.4) and 39.3 (95% CI 32.1 to 46.4), respectively. The mean Visual Analogue Score for pain was 3.1 (95% 1.4 to 4.9). The mean Ankle Osteoarthritis Scale total score was 32.9 (95% CI 16.0 to 49.7). Fluoroscopy-guided reduction and fibular nail fixation of unstable ankle fractures in patients with diabetes was associated with a low incidence of wound and overall complications, while providing effective surgical fixation. Cite this article: Bone Joint J 2016;98-B:1197-1201. ©2016 The British Editorial Society of Bone & Joint Surgery.

Clinical comparative analysis on unstable pelvic fractures in the treatment with percutaneous sacroiliac screws and sacroiliac joint anterior plate fixation.

PubMed

Li, C-L

2014-01-01

To investigate clinical efficacy of unstable pelvic fractures in the treatment with percutaneous sacroiliac screws and sacroiliac joint anterior plate fixation. 64 patients with unstable pelvic fractures were selected in the hospital from January 2008 to June 2011, and were randomly divided into two groups.(32 patients with sacroiliac anterior plate fixation as the control group, and another 32 patients with percutaneous sacroiliac screw internal fixation as the observation group). The perioperative period clinical indicators, postoperative Matta score, postoperative Majeed function score of all patients were compared and analyzed. The operation time, intraoperative blood loss, wound total length, postoperative fever time, duration of hospitalization in the observation group were significantly less than those in the control group. The complication rate (3.1%) in the observation group was lower than that in the control group (21.9%). The rate of Matta score excellent (96.9%) in the observation group was higher than that in the control group (81.2%) after the treatment. The rate of Majeed function score excellent (93.8%) in the observation group was significantly higher than that in the control group (75%) after the treatment. Percutaneous sacroiliac screw internal fixation in the treatment of unstable pelvic fractures has less injury, less bleeding, less pain and rapid recovery which is a safe and effective minimally invasive operation method. The clinical curative effect of percutaneous sacroiliac screw internal fixation is better than anterior plate fixation for the treatment of sacroiliac joint. The full preparation before the surgery and patients with positive can substantially reduce the occurrence of complications rate.

Cyclic Stable-Unstable Slip Preserved along an Appalachian Fault

NASA Astrophysics Data System (ADS)

Wells, R. K.; Newman, J.; Holyoke, C. W., III; Wojtal, S. F.

2017-12-01

The inactive Copper Creek thrust, southern Appalachians, TN, preserves evidence suggesting cyclic aseismic and unstable slip. The Copper Creek thrust is a low-temperature (4-6 km burial depth) foreland thrust with an estimated net slip of 15-20 km. Immediately below the 2 cm thick calcite-shale fault zone, the footwall is composed of shale with cross-cutting calcite veins and is separated from the fault zone by a 300 µm thick layered calcite vein. Optical and electron microscopy indicates that this complex vein layer experienced grain size reduction by plasticity-induced fracturing followed by aseismic diffusion creep. The fault zone calcite exhibits interpenetrating grain boundaries and four-grain junctions suggesting diffusion creep, but also contains nanoscale grains (7 nm), vesicular calcite, and partially-coated clasts indicating unstable, possibly seismic, slip. Well-preserved clasts of deformed calcite vein layer material within the fault zone indicate repeated cycle(s) of aseismic diffusion creep. In addition, nanoscale calcite grains, 30 nm, with straight grain boundaries that form triple junctions, may represent earlier nanoscale grains formed during unstable slip that have experienced grain growth during periods of aseismic creep. Based on the spatial and temporal relations of these preserved microstructures, we propose a sequence of deformation processes consistent with cyclic episodes of unstable slip separated by intervals of aseismic creep. Formation of calcite-filled veins is followed by grain size reduction in vein calcite by plasticity-induced fracturing and aseismic grain-size sensitive diffusion creep deformation in fine-grained calcite. During aseismic creep, the combination of grain growth, resulting in fault strengthening, and an increase in pore fluid pressure, reducing the effective fault strength, leads to new fractures and/or an unstable slip event. During unstable slip, nanograins and vesicular calcite form as a result of thermal decomposition and coated clasts form as a result of fluidization of the fault zone, and are then incorporated within ductilely deforming calcite during a new interval of aseismic creep.

Unstable upper and middle thoracic fractures. Preliminary experience with a posterior transpedicular correction-fixation technique.

PubMed

Payer, M

2005-06-01

A number of conservative and operative approaches have been described for the treatment of unstable traumatic upper and middle thoracic fractures. The advantage of surgical correction and fixation/fusion lies in its potential to restore sagittal and coronal alignment, thereby indirectly decompressing the spinal cord. A consecutive series of 8 patients with unstable traumatic upper and middle thoracic fractures is reviewed. In all patients, polyaxial pedicle screws were inserted bilaterally into the two levels above and below the fracture. Rods that were less contoured ("undercontoured") than the regional hyperkyphosis at the injured level, were anchored to the caudal four screws. The cranial four screws, with the vertebrae to which they were inserted, were then progressively pulled posteriorly onto the undercontoured rods with rod reducers, thus correcting the hyperkyphosis and anterolisthesis. The mean follow-up was 15 months. The mean regional kyphosis was 23 degrees preoperatively, 17 degrees postoperatively and 18 degrees at follow-up. The mean anterolisthesis was 8 mm preoperatively, 1 mm postoperatively and 1 mm at follow-up. No hardware failure occurred. Five patients with complete spinal cord injury at presentation made no neurological recovery, two patients with incomplete spinal cord injury initially (ASIA B), recovered substantially (to ASIA D), and the patients who were neurologically intact at presentation remained so.

[Kirschner wire transfixation of unstable ankle fractures: indication, surgical technique and outcomes].

PubMed

Marvan, J; Džupa, V; Bartoška, R; Kachlík, D; Krbec, M; Báča, V

2015-01-01

PURPOSE OF THE STUDY The aim of the study was to assess treatment outcomes in patients undergoing K-wire transfixation of unstable ankle fractures and compare the results with those of patients in whom it was possible to perform primary one-stage osteosynthesis. MATERIAL AND METHODS Between 2009 and 2012, a total of 358 patients (191 women and 167 men) had surgery for unstable ankle fracture. At 1-year follow-up, their subjective feelings, objective findings and ankle radiographs were evaluated. The fractures were categorised according to the Weber classification. A patient group treated by one-stage osteosynthesis, a group with definitive transfixation and a group of patients in whom temporary transfixation was converted to definitive osteosynthesis were assessed and compared. RESULTS The group treated by one-stage osteosynthesis included 278 patients with an average age of 47 years; the group of 20 patients with definitive transfixation had an average age of 67 years, and the group of 60 patients who had temporary transfixation with subsequent conversion to internal osteosynthesis were 55 years on average. In the group with one-stage osteosynthesis, 223 (80%) ankle fractures on post-injury radiographs were associated with minor joint dislocations and 55 (20%) with major dislocations. On the other hand, the radiographs of the patients treated by temporary transfixation and delayed open reduction with internal fixation showed major dislocations in 38 (63%) and minor dislocations in the rest of the patients (37%); the difference between the two groups was statistically significant (p<0.001). Posterior malleolar fractures were most frequent in the group with temporary transfixation (60%) and least frequent in the group with primary osteosynthesis (44%); also this difference was statistically significant (p=0.032). At one-year follow-up, in the group with one-stage osteosynthesis, 220 patients (79%) had no radiographic signs of posttraumatic ankle osteoarthritis while, in the group with temporary transfixation, no radiographic evidence of ankle osteoarthritis was recorded in 25 (42%) patients. While tibiofibular synostosis was recorded in only few patients (9%) of the group with one-stage osteosynthesis, it showed a high occurrence in the group with temporary transfixation (35%). The patients with one-stage osteosynthesis (188/68%) had a higher proportion of excellent outcomes measured on the Olerund-Molander ankle scoring scale than the other two groups (temporary transfixation, 47%; definitive transfixation,10%); in both cases the difference was significant (p < 0.001 and p = 0.003, respectively). DISCUSSION In this study the morphological and clinical aspects of surgically treated ankle fractures were assessed. The patients with one-stage osteosynthesis were compared with those treated by temporary or definitive transfixation. The majority of patients undergoing temporary transfixation had a fractured posterior margin of the tibia and major ankle joint dislocation, which suggested serious injuries to bone and ligament structures. Generally, the use of only two K-wires inserted through the calcaneus and talus into the distal tibia is recommended. Patients with K-wire transfixation usually require a longer hospital stay because of the serious nature of their injuries. CONCLUSIONS The therapy of choice for unstable ankle fractures is one-stage osteosynthesis. Temporary transfixation is an effective method of primary management when an unstable fracture cannot be treated by definitive osteosynthesis at the early stage due to local or general health conditions of the patient. The temporary transfixation provides good alignment of the ankle joint necessary for successful healing of soft tissues. A higher occurrence of post-traumatic ankle osteoarthritis, ossification and distal tibiotalar synostosis found in the patients treated by temporary transfixation is more related to serious types of ankle fractures the patient had suffered than to the method itself. Key words: unstable ankle fracture, soft tissue condition, indications for transfixation, treatment outcome.

Pelvic trauma with displaced sacral fractures: functional outcome at one year.

PubMed

Tötterman, Anna; Glott, Thomas; Søberg, Helene Lundgaard; Madsen, Jan Erik; Røise, Olav

2007-06-01

A prospective single-cohort study of 31 patients surgically treated for pelvic injuries with displaced sacral fractures. To describe the medium term functional outcome in unstable sacral fractures. Displaced sacral fractures pose a special challenge in orthopedic surgery due to the high rate of associated injuries. Little information is available on the medium-term functional outcome of patients with injuries which include unstable sacral fractures. We examined 31 patients with displaced sacral fractures having 10 mm or more displacement, 1 year (mean, 1.4 years; range, 1.0-2.5 years) after injury. Data from a previous study were supplemented with functional outcome measures (work status, independence in ADL, and SF-36). An association between outcome and tested variables was sought. Fifteen months after injury, 65% of the patients had regained their independence in functions pertaining to daily activities; 33% had returned to work. All dimensions of perceived health were affected. Polytrauma and impairments relative to voiding and sexual function had a detrimental effect on outcome. Fracture characteristics were not predictive of poor outcome. Although the majority of patients achieved independent living, medium-term follow-up indicated significant residual disability. The complex nature of these fractures and the associated injuries should be considered in the rehabilitation of these patients.

Appropriate hinge position for prevention of unstable lateral hinge fracture in open wedge high tibial osteotomy.

PubMed

Nakamura, R; Komatsu, N; Fujita, K; Kuroda, K; Takahashi, M; Omi, R; Katsuki, Y; Tsuchiya, H

2017-10-01

Open wedge high tibial osteotomy (OWHTO) for medial-compartment osteoarthritis of the knee can be complicated by intra-operative lateral hinge fracture (LHF). We aimed to establish the relationship between hinge position and fracture types, and suggest an appropriate hinge position to reduce the risk of this complication. Consecutive patients undergoing OWHTO were evaluated on coronal multiplanar reconstruction CT images. Hinge positions were divided into five zones in our new classification, by their relationship to the proximal tibiofibular joint (PTFJ). Fractures were classified into types I, II, and III according to the Takeuchi classification. Among 111 patients undergoing OWHTOs, 22 sustained lateral hinge fractures. Of the 89 patients without fractures, 70 had hinges in the zone within the PTFJ and lateral to the medial margin of the PTFJ (zone WL), just above the PTFJ. Among the five zones, the relative risk of unstable fracture was significantly lower in zone WL (relative risk 0.24, confidence interval 0.17 to 0.34). Zone WL appears to offer the safest position for the placement of the osteotomy hinge when trying to avoid a fracture at the osteotomy site. Cite this article: Bone Joint J 2017;99B10:1313-18. ©2017 The British Editorial Society of Bone & Joint Surgery.

A Medial Malleolar "Fleck Sign" May Predict Ankle Instability in Ligamentous Supination External Rotation Ankle Fractures.

PubMed

Nwosu, Kenneth; Schneiderman, Brian Andrew; Shymon, Stephen Joseph; Harris, Thomas

2018-06-01

Ankle joint stability dictates treatment in ligamentous supination external rotation ankle injuries (LSERAI). Investigation of the medial structures that support the ankle mortise is critical, and a small avulsion fracture, or "fleck", of the medial malleolus is occasionally encountered. This study aimed to assess the utility of this medial malleolus fleck sign (MMFS) in diagnosing instability requiring surgery in LSERAI. This retrospective observational study examined 166 LSERAI at a single level I trauma center. A standardized diagnostic and treatment protocol for ankle fractures was followed. LSERAI at presentation were reported as having a normal, dynamically wide, or statically wide medial clear space. Patient demographics, MMFS characteristics, and the use of operative management were recorded. MMFS incidence in the cohort was 16 (10%) of 166 and was present in 25% of patients with unstable LSERAI. Fifteen (94%) of 16 patients with a MMFS were deemed to have an unstable LSERAI (P < .005). MMFS had a 25% sensitivity and 99% specificity in diagnosing an unstable LSERAI. For the subgroup of patients without a statically wide medial clear space, MMFS had a 50% sensitivity and 99% specificity in determining instability. A MMFS may be indicative of an unstable LSERAI. With previous MRI studies demonstrating complete deltoid disruption in unstable LSERAI, we deduce the MMFS may be associated with extensive deltoid incompetence. The MMFS may help to diagnose a complete deltoid injury in LSERAI with a normal medial clear space, which could influence treatment and reduce patient morbidity, radiation exposure, and healthcare costs. Level III: Retrospective Cohort Study.

[Stable ankle joint fractures. Indication for surgical or conservative management?].

PubMed

Richter, J; Schulze, W; Muhr, G

1999-06-01

In German literature, ankle joint fractures are mostly classified in three groups according to Weber. In cases of the type A, the fracture line runs below, in cases of type B at height of the syndesmotic ligaments. C-type fractures are typically seen above this region. However, this practical and simple classification allows no inferences at accompanying injuries which in turn influence the functional outcome. We observed isolated fractures of the lateral malleolus in more than 60% of all type B-fractures, as soon as in the majority the type A-fractures. Since isolated medial ankle fractures occur very rarely, careful exclusion of further injuries is advisable here. In order to differentiate stable ones from unstable type B ankle injuries, we carry out a manual stress test, if there is less than 2 mm fracture dislocation and a congruent ankle mortise. In this manner we could find that stable lateral ankle fractures are characterized with a combination of an intact dorsal syndesmotic and medial ligament. Stable type B and undisplaced type A fractures were treated conservatively with an ankle brace (Aircast?). Unstable ankle injuries were treated by ORIF. Conservative treatment for undisplaced medial malleolar fractures is recommended, if x-rays showed less than 2 mm dislocation which allows a tibio-talare impingement. Biomechanical investigations could prove a significant increase in ankle joint stability, when an axial load of 300 N was applied to various horizontal loads. The talus does not follow automatically a displaced fibular fracture. The dorsal syndesmotic and the medial deltoid ligaments control ankle joint stability.

Management of acute unstable distal clavicle fracture with a modified coracoclavicular stabilization technique using a bidirectional coracoclavicular loop system.

PubMed

Kanchanatawan, Wichan; Wongthongsalee, Ponrachai

2016-02-01

Fracture of the distal clavicle is not uncommon. Despite the vast literature available for the management of this fracture, there is no consensus regarding the gold standard treatment for this fracture. To assess the clinical and radiographic outcomes and complications of acute unstable distal clavicle fracture when treated by a modified coracoclavicular stabilization technique using a bidirectional coracoclavicular loop system. Thirty-nine patients (32 males, 7 females) with acute unstable distal clavicle fractures treated by modified coracoclavicular stabilization using the surgical technique of bidirectional coracoclavicular (CC) loops seated behind the coracoacromial (CA) ligament were retrospectively reviewed. Mean follow-up time was 35.7 months (range 24-47 months). The outcomes measured included union rate, union time, CC distances when compared to the patients' uninjured shoulders, and the Constant and ASES shoulder scores, which were evaluated 6 months after surgery. All fractures displayed clinical union within 13 weeks postoperatively. The mean union time was 9.2 weeks (range 7-13 weeks). At the time of union, the CC distances on the affected shoulders were on average 0.9 mm (range 0-1.6 mm) longer than the unaffected shoulders. At 6 months after surgery, the Constant and ASES scores were on average 93.4 (72-100) and 91.5 (75-100), respectively. No complications related to the fixation loops, musculocutaneous nerve injuries, or fractures of coracoid or clavicle were recorded. One case of surgical wound dehiscence was observed due to superficial infection. Enlargement of the clavicle drill hole without migration of the buttons was observed in 9 out of 16 cases at a follow-up time of at least 30 months after the original operation. Modified CC stabilization using bidirectional CC loops seated behind the CA ligament is a simple surgical technique that naturally restores stability to the distal clavicle fracture. It also produces predictable outcomes, a high union rate, good to excellent shoulder function, and a low complication rate. The buttons and suture loops were routinely removed in a second operation in order to prevent late stress fracture of the clavicle.

[Long-term efficacy of open reduction and internal fixation versus external fixation for unstable distal radius fractures: a meta-analysis].

PubMed

Yang, Z; Yuan, Z Z; Ma, J X; Ma, X L

2017-11-07

Objective: To make a systematic assessment of the Long-term efficacy of open reduction and internal fixation versus external fixation for unstable distal radius fractures. Methods: A computer-based online search of PubMed, ScienceDirect, EMBASE, BIOSIS, Springer and Cochrane Library were performed. The randomized and controlled trials of open reduction and internal fixation versus external fixation for unstable distal radius fractures were collected. The included trials were screened out strictly based on the criterion of inclusion and exclusion. The quality of included trials was evaluated. RevMan 5.0 was used for data analysis. Results: Sixteen studies involving 1 268 patients were included. There were 618 patients with open reduction and internal fixation and 650 with external fixation. The results of meta-analysis indicated that there were statistically significant differences with regard to the complications postoperatively (infection( I (2)=0%, RR =0.27, 95% CI 0.16-0.45, Z =4.92, P <0.000 01) and total complications( I (2)=0%, RR =0.71, 95% CI 0.59-0.85, Z =3.65, P =0.000 3) ), DASH scores( I (2)=37%, MD =-5.67, 95% CI -8.31--3.04, Z =4.22, P <0.000 1) and volar tilt( I (2)=78%, MD =2.29, 95% CI 0.33-4.24, Z =2.30, P =0.02)( P <0.05) at the end of follow-up period were noted. There were no statistically significant differences observed between two approaches with respect to the clinical outcomes (grip strength, flexion, extension, pronation, supination, radial deviation and ulnar deviation) and radiographic outcome(radial length) at the end of follow-up period( P <0.05). Conclusion: Both open reduction and internal fixation and external fixation are effective treatment for unstable distal radius fractures. Compared with external fixation, open reduction and internal fixation provides reduced complications postoperatively, lower DASH scores and better restoration of volar tilt for treatment of distal radius fractures.

When do anterior external or internal fixators provide additional stability in an unstable (Tile C) pelvic fracture? A biomechanical study.

PubMed

Mcdonald, E; Theologis, A A; Horst, P; Kandemir, U; Pekmezci, M

2015-12-01

This study aimed at evaluating the additional stability that is provided by anterior external and internal fixators in an unstable pelvic fracture model (OTA 61-C). An unstable pelvic fracture (OTA 61-C) was created in 27 synthetic pelves by making a 5-mm gap through the sacral foramina (posterior injury) and an ipsilateral pubic rami fracture (anterior injury). The posterior injury was fixed with either a single iliosacral (IS) screw, a single trans-iliac, trans-sacral (TS) screw, or two iliosacral screws (S1S2). Two anterior fixation techniques were utilized: external fixation (Ex-Fix) and supra-acetabular external fixation and internal fixation (In-Fix); supra-acetabular pedicle screws connected with a single subcutaneous spinal rod. The specimens were tested using a nondestructive single-leg stance model. Peak-to-peak (P2P) displacement and rotation and conditioning displacement (CD) were calculated. The Ex-Fix group failed in 83.3 % of specimens with concomitant single-level posterior fixation (Total: 15/18-7 of 9 IS fixation, 8 of 9 TS fixation), and 0 % (0/9) of specimens with concomitant two-level (S1S2) posterior fixation. All specimens with the In-Fix survived testing except for two specimens treated with In-Fix combined with IS fixation. Trans-sacral fixation had higher pubic rotation and greater sacral and pubic displacement than S1S2 (p < 0.05). Rotation of the pubis and sacrum was not different between In-Fix constructs combined with single-level IS and TS fixation. In this model of an unstable pelvic fracture (OTA 61-C), anterior fixation with an In-Fix was biomechanically superior to an anterior Ex-Fix in the setting of single-level posterior fixation. There was no biomechanical difference between the In-Fix and Ex-Fix when each was combined with two levels of posterior sacral fixation.

[The rotationally stable screw-anchor with trochanteric stabilizing plate (RoSA/TSP) : First results in unstable trochanteric femur fractures].

PubMed

Maier, K-J; Bücking, B; Horst, K; Andruszkow, H; Hildebrand, F; Knobe, M

2017-12-01

In unstable trochanteric fractures, the extramedullary rotationally stable screw-anchor (RoSA) combines the benefits of the load and rotational stability of the blade with the advantages of the screw (pull-out resistance, compression capability) in a single load carrier, and was designed to prevent femoral neck shortening by using an additional locked trochanteric stabilizing plate (TSP). The aim of the current prospective cohort study was the clinical evaluation of the RoSA/TSP system regarding the mechanical re-operation rate and the amount of postoperative femoral neck shortening. From September 2011 to January 2014 80 patients with unstable trochanteric fractures underwent internal extramedullary fixation with the RoSA/TSP (Königsee Implantate GmbH, Allendorf, Germany). Due to fracture stability and after induction of compression, additional long locked antitelescoping screws (AT, n = 1-4) were placed reaching the femoral head. Radiological (femoral neck shortening) and clinical re-examination of patients (n = 61) was performed 6-10 weeks and 6-10 months later. In the 61 re-examined patients (76 %) femoral neck shortening was very low with 2 mm 6-10 months after operation. Re-operations occurred in 8 % (n = 6) and in 4 % (n = 3) as prophylactic surgical intervention. Whereas one-third (4 %) of re-operations occurred due to iatrogenic surgical problems from the first operation two-thirds of patients (8 %) had a re-operation due to delay of bone union (3× nonunion, 3 planned removals of AT-screws to improve healing). The in-hospital mortality was 3 % (n = 2). The fixation of unstable trochanteric femur fractures using the RoSA/TSP in a first clinical setting led to a great primary stability, with significant advantages with regard to limited femoral neck shortening. However, the rigidity of the construct with its consequences regarding bone healing can be challenging for the surgeon. Nevertheless, in some cases of revision it could be beneficial for stability.

Comparing the predictive value of the pelvic ring injury classification systems by Tile and by Young and Burgess.

PubMed

Osterhoff, Georg; Scheyerer, Max J; Fritz, Yannick; Bouaicha, Samy; Wanner, Guido A; Simmen, Hans-Peter; Werner, Clément M L

2014-04-01

Radiology-based classifications of pelvic ring injuries and their relevance for the prognosis of morbidity and mortality are disputed in the literature. The purpose of this study was to evaluate potential differences between the pelvic ring injury classification systems by Tile and by Young and Burgess with regard to their predictive value on mortality, transfusion/infusion requirement and concomitant injuries. Two-hundred-and-eighty-five consecutive patients with pelvic ring fractures were analyzed for mortality within 30 days after admission, number of blood units and total volume of fluid infused during the first 24h after trauma, the Abbreviated Injury Severity (AIS) scores for head, chest, spine, abdomen and extremities as a function of the Tile and the Young-Burgess classifications. There was no significant relationship between occurrence of death and fracture pattern but a significant relationship between fracture pattern and need for blood units/total fluid volume for Tile (p<.001/p<.001) and Young-Burgess (p<.001/p<.001). In both classifications, open book fractures were associated with more fluid requirement and more severe injuries of the abdomen, spine and extremities (p<.05). When divided into the larger subgroups "partially stable" and "unstable", unstable fractures were associated with a higher mortality rate in the Young-Burgess system (p=.036). In both classifications, patients with unstable fractures required significantly more blood transfusions (p<.001) and total fluid infusion (p<.001) and higher AIS scores. In this first direct comparison of both classifications, we found no clinical relevant differences with regard to their predictive value on mortality, transfusion/infusion requirement and concomitant injuries. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of three-dimensional printing for internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach: a preliminary report.

PubMed

Zeng, Canjun; Xiao, Jidong; Wu, Zhanglin; Huang, Wenhua

2015-01-01

The aim of this study is to evaluate the efficacy and feasibility of three-dimensional printing (3D printing) assisted internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach. A total of 38 patients with unstable pelvic fractures were analyzed retrospectively from August 2012 to February 2014. All cases were treated operatively with internal fixation assisted by three-dimensional printing from minimal invasive para-rectus abdominis approach. Both preoperative CT and three-dimensional reconstruction were performed. Pelvic model was created by 3D printing. Data including the best entry points, plate position and direction and length of screw were obtained from simulated operation based on 3D printing pelvic model. The diaplasis and internal fixation were performed by minimal invasive para-rectus abdominis approach according to the optimized dada in real surgical procedure. Matta and Majeed score were used to evaluate currative effects after operation. According to the Matta standard, the outcome of the diaplasis achieved 97.37% with excellent and good. Majeed assessment showed 94.4% with excellent and good. The imageological examination showed consistency of internal fixation and simulated operation. The mean operation time was 110 minutes, mean intraoperative blood loss 320 ml, and mean incision length 6.5 cm. All patients have achieved clinical healing, with mean healing time of 8 weeks. Three-dimensional printing assisted internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach is feasible and effective. This method has the advantages of trauma minimally, bleeding less, healing rapidly and satisfactory reduction, and worthwhile for spreading in clinical practice.

Comparison of occipitocervical and atlantoaxial fusion in treatment of unstable Jefferson fractures.

PubMed

Hu, Yong; Yuan, Zhen-Shan; Kepler, Christopher K; Dong, Wei-Xin; Sun, Xiao-Yang; Zhang, Jiao

2017-01-01

Controversy exists regarding the management of unstable Jefferson fractures, with some surgeons performing reduction and immobilization of the patient in a halo vest and others performing open reduction and internal fixation. This study compares the clinical and radiological outcome parameters between posterior atlantoaxial fusion (AAF) and occipitocervical fusion (OCF) constructs in the treatment of the unstable atlas fracture. 68 consecutive patients with unstable Jefferson fractures treated by AAF or OCF between October 2004 and March 2011 were included in this retrospective evaluation from institutional databases. The authors reviewed medical records and original images. The patients were divided into two surgical groups treated with either AAF ( n = 48, F/M 30:18) and OCF ( n = 20, F/M 13:7) fusion. Blood loss, operative time, Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score, atlanto-dens interval, lateral mass displacement, complications, and the bone fusion rates were recorded. Five patients with incomplete paralysis (7.4%) demonstrated postoperative improvement by more than 1 grade on the American Spinal Injury Association impairment scale. The JOA score of the AAF group improved from 12.5 ± 3.6 preoperatively to 15.7 ± 2.3 postoperatively, while the JOA score of the OCF group improved from 11.2 ± 3.3 preoperatively to 14.8 ± 4.2 postoperatively. The VAS score of AAF group decreased from 4.8 ± 1.5 preoperatively to 1.0 ± 0.4 postoperatively, the VAS score of the OCF group decreased from 5.4 ± 2.2 preoperatively to 1.3 ± 0.9 postoperatively. The OCF or AAF combined with short-term external immobilization can establish the upper cervical stability and prevent further spinal cord injury and nerve function damage.

Injuries of the Medial Clavicle: A Cohort Analysis in a Level-I-Trauma-Center. Concomitant Injuries. Management. Classification.

PubMed

Bakir, Mustafa Sinan; Merschin, David; Unterkofler, Jan; Guembel, Denis; Langenbach, Andreas; Ekkernkamp, Axel; Schulz-Drost, Stefan

2017-01-01

Introduction: Although shoulder girdle injuries are frequent, those of the medial clavicle are widely unexplored. An applied classification is less used just as a standard management. Methods: A retrospective analysis of medial clavicle injuries (MCI) during a 5-year-term in a Level-1-Trauma-Center. We analyzed amongst others concomitant injuries, therapy strategies and the classification following the AO standards. Results: 19 (2.5%) out of 759 clavicula injuries were medial ones (11 A, 6 B and 2 C-Type fractures) thereunder 27,8% were displaced and thus operatively treated Locked plate osteosynthesis was employed in unstable fractures and a reconstruction of the ligaments at the sternoclavicular joint (SCJ) in case of their disruption. 84,2% of the patients sustained relevant concomitant injuries. Numerous midshaft fractures were miscoded as medial fracture, which limited the study population. Conclusions: MCI resulted from high impact mechanisms of injury, often with relevant dislocation and concomitant injuries. Concerning medial injury's complexity, treatment should occur in specialized hospitals. Unstable fractures and injuries of the SCJ ligaments should be considered for operative treatment. Midshaft fractures should be clearly distinguished from the medial ones in ICD-10-coding. Further studies are required also regarding a subtyping of the AO classification for medial clavicle fractures including ligamental injuries. Celsius.

A mathematical simulation of the tip-apex distance and the calcar-referenced tip-apex distance for intertrochanteric fractures reduced with lag screws.

PubMed

Li, Shuang; Chang, Shi-Min; Jin, Yan-Min; Zhang, Ying-Qi; Niu, Wen-Xin; Du, Shou-Chao; Zhang, Li-Zhi; Ma, Hui

2016-06-01

As a predictor of the risk of lag screw cutout, it was recommended that keeping tip-apex distance (TAD)<25mm and placing the screw centrally or inferiorly, but positioning the lag screw too inferiorly in the head would produce TAD>25mm. We aim to simulate various positions of the lag screw in the femoral head and identify whether 25mm is a suitable cut-off value that favours all sizes of femoral heads with intertrochanteric fractures of the hip. Using a general mathematical software, the positions of the screw tip points were simulated. The virtual anterior-posterior and lateral views were then visualised, and the locus of the screw tips was projected into a Cartesian coordinate system according to the TAD and calcar-referenced tip-apex distance (CalTAD) formulas. Each original virtual anterior-posterior and lateral image was zoomed and compiled to match a calculated average image. The screw tip points were recorded, traced and compiled into volumes which could be used to visualise the screw's movements and positioning within the femoral head. The extracted volumes were calculated when 10mm

Seat belt syndrome with unstable Chance fracture dislocation of the second lumbar vertebra without neurological deficits.

PubMed

Onu, David O; Hunn, Andrew W; Bohmer, Robert D

2014-01-08

The seat belt syndrome is a recognised complication of seat belt use in vehicles. Unstable Chance fractures of the spine without neurological deficits have been reported infrequently. We describe a young woman with completely disrupted Chance fracture of the second lumbar vertebra in association with left hemidiaphragmatic rupture/hernia, multiple bowel perforations, splenic capsular tear, left humeral shaft and multiple rib fractures. These injuries which resulted from high-speed vehicle collision and led to death of one of the occupants were readily detected by trauma series imaging. The patient was successfully treated by a dedicated multidisciplinary team which adopted a staged surgical approach and prioritisation of care. There were no manifested neurological or other deficits after 1 year of follow-up. To the authors' knowledge, this is the first report of such a case in Australasia. We discuss the challenging surgical management, highlighting the role of radiological imaging in such cases and provide a literature review.

A new mini-invasive technique in treating pediatric diaphyseal forearm fractures by bioabsorbable elastic stable intramedullary nailing: a preliminary technical report.

PubMed

Sinikumpu, J-J; Keränen, J; Haltia, A-M; Serlo, W; Merikanto, J

2013-01-01

Operative treatment is often indicated in unstable pediatric diaphyseal forearm fractures. Recently minimally invasive reduction and elastic stable intramedullary nailing have been of increasing interest, instead of open reduction and internal fixation with plates. There are several disadvantages of metallic intramedullary implants, such as soft-tissue irritation and a risk of disturbing later imaging. Thus, they are generally removed in later operations. We aimed to develop a new technique to stabilize pediatric forearm fractures by the bioabsorbable intramedullary nailing. We developed a new, two-stage mini-invasive surgical technique to stabilize the unstable diaphyseal fractures in children. The procedure is bioabsorbable elastic stable intramedullary nailing. Ultra-high-strength bioabsorbable intramedullary nails of poly(lactide-co-glycolide) were manufactured for our purpose. The material has been widely proven to be biocompatible and stable enough for fracture treatment as screws and pins. We have used the new technique in the unstable both-bone diaphyseal forearm fractures in children between the ages of 5 and 15 years. We report the technique and our clinical experience in the series of those three cases that have been followed up for at least 12 months. The present series has been randomized for the procedure instead for titanium elastic stable intramedullary nailing, and the series represents a part of ongoing randomized trial. The reported cases operated by the new technique referred good union in the fractured bones and acceptable alignment in the follow-up. Removal of the implants was not required. No troubles with the procedure or implant per se were noticed, indicating good feasibility. One high-energy refracture occurred half year after the primary trauma. Traditional titanium implants were used to control the refracture. We report our preliminary experience of a new surgical mini-invasive procedure to stabilize the unstable pediatric forearm shaft fractures by bioabsorbable elastic stable intramedullary nailing. Our clinical experience suggests that the procedure combined with long-arm casting is feasible in treating the pediatric forearm fractures. The technique may bring benefits to handling these challenging fractures. The disadvantages of metallic implants may be avoided. In addition, removal of the implant will not be required. There was one refracture in the series, but it was due to new high-energy trauma. According to our understanding, it was not related to the type of former osteosynthesis. However, ignoring the good preliminary experience, still we do not have results of the superiority of the procedure over traditional elastic stable intramedullary nailing. Our ongoing randomized multicenter study is aimed to determine its long-term outcome against the present golden standard. Nevertheless, due to encouraging preliminary results, we see it necessary to report the technique.

Spinal Stabilization Using Orthopedic Extremity Instrumentation Sets During Operation Enduring Freedom-Afghanistan.

PubMed

Ravindra, Vijay M; Wallace, Scott A; Vaidya, Rahul; Fox, W Christopher; Klugh, Arnett R; Puskas, David; Park, Min S

2016-02-01

The Role III, Multinational Medical Unit at Kandahar Air Field, Afghanistan, was established to provide combat casualty care in theater for International Security Assistance Forces, Afghanistan National Security Forces, and local nationals during Operation Enduring Freedom-Afghanistan. The authors describe their experience of treating unstable lumbar spine fractures with orthopedic extremity instrumentation sets from January 2007 to January 2008 and November 2010 to May 2011. During the study periods, 15 patients comprising Afghanistan National Security Forces and local nationals presented to the medical facility for treatment of unstable lumbar spine fractures. The patients underwent surgery for either anterior corpectomy and instrumented fusion (n = 5) or posterior instrumented fusion (n = 10). Because of periodic scarcity of spinal instrumentation sets, orthopedic extremity instrumentation sets were used (Synthes Large Fragment LCP Instrument and Implant Set) for spinal stabilization. Immediate postoperative standing and sitting plain radiographs demonstrated no evidence of fracture progression or immediate hardware failure. One patient was seen in follow-up at 4 weeks and demonstrated construct stability on follow-up radiographs. In the combat environment with sparse resources, unstable spine fractures may potentially be treated using instrumentation not specifically designed for spinal implantation. This is an off-label use, and the authors do not recommend the use of these techniques as standard treatment in most medical environments. Copyright © 2016 Elsevier Inc. All rights reserved.

The kinetic and mechanical aspects of hydrogen-induced failure in metals. Ph.D. Thesis, 1971

NASA Technical Reports Server (NTRS)

Nelson, H. G.

1972-01-01

Premature hydrogen-induced failure observed to occur in many metal systems involves three stages of fracture: (1) crack initiation, (2) stable slow crack growth, and (3) unstable rapid crack growth. The presence of hydrogen at some critical location on the metal surface or within the metal lattice was shown to influence one or both of the first two stages of brittle fracture but has a negligible effect on the unstable rapid crack growth stage. The relative influence of the applied parameters of time, temperature, etc., on the propensity of a metal to exhibit hydrogen induced premature failure was investigated.

The focused abdominal sonography for trauma examination can reliably identify patients with significant intra-abdominal hemorrhage in life-threatening pelvic fractures.

PubMed

Christian, Nicole Townsend; Burlew, Clay Cothren; Moore, Ernest E; Geddes, Andrea E; Wagenaar, Amy E; Fox, Charles J; Pieracci, Fredric M

2018-06-01

The focused abdominal sonography for trauma (FAST) examination has been reported to be unreliable in pelvic fracture patients. Additionally, given the advent of new therapeutic interventions, such as resuscitative endovascular balloon occlusion of the aorta (REBOA), rapid identification of intra-abdominal hemorrhage compared with Zone III hemorrhage may guide different therapeutic strategies. We hypothesized that FAST is reliable for detecting clinically significant intra-abdominal hemorrhage in the face of complex pelvic fractures. Our pelvic fracture database of all hemodynamically unstable patients requiring intervention from January 1, 2005, to July 1, 2015, was reviewed. The FAST examination was compared with operative and computed tomography (CT) scan findings. Confirmatory evaluation for FAST(-) patients was considered positive if therapeutic intervention was required. During the study period, 81 patients in refractory shock with FAST imaging in our emergency department (ED) underwent pelvic packing. Mean age was 45 ± 2 years and Injury Severity Score was 50 ± 1.5. The FAST examination was negative in 53 patients; 52 patients did not require operative intervention for abdominal bleeding while one patient required splenectomy. The FAST examination was positive in 28 patients; 26 had findings confirmed by CT or laparotomy while two patients did not have intra-abdominal hemorrhage on further evaluation. The sensitivity and specificity for FAST in this population was 96% and 96%, respectively, positive predictive value was 93%, and negative predictive value was 98%. The false-negative and -positive rates for FAST were 2% and 7%. Focused abdominal sonography for trauma examination reliably identifies clinically significant hemoperitoneum in life-threatening, pelvic fracture related hemorrhage. The incidence of a false-negative FAST in this unstable pelvic fracture population was 2%. FAST results may be used when determining the role of REBOA in these multisystem trauma patients and requires further study. REBOA placement should be considered in hemodynamically unstable pelvic fracture patients who are FAST(-), while laparotomy should be used in FAST(+) patients. Therapeutic, level IV.

Strain Rate Sensitivity of Polymer-Matrix Composites under Mode I delamination

DTIC Science & Technology

1990-12-01

unstable growth system requires two values. In reality , the fracture toughness may vary along the length of the specimen due to strain rate effects...18 M. F. Kanninen. An Augmented Double Cantilever Beam Model for Studying Crack Propagation and Arrest. International Journal of Fracture. Vol. 9

Imaging in traumatic mandibular fractures

PubMed Central

Gemal, Hugo; Reed, Duncan

2017-01-01

A fracture of the mandible is a common trauma presentation amongst young males and represents one of the most frequently encountered fractured bones within the viscerocranium. Historically, assault was the dominant contributing factor but now due to the increased number of vehicles used per capita, motor vehicle accidents are the primary cause. Mandibular fractures can be classified anatomically, by dentition, by muscle group and by severity. The fracture may also be closed, open, comminuted, displaced or pathological. It is important that the imaging modality used identifies the classification as this will decide definitive treatment. X-ray projections have typically been used to detect a mandibular fracture, but are limited to an anteroposterior (AP), lateral and oblique view in an unstable trauma patient. These views are inadequate to detail the level of fracture displacement and show poor detail of the condylar region. Computer tomography (CT) is the imaging modality of choice when assessing a traumatic mandibular injury and can demonstrate a 100% sensitivity in detecting a fracture. This is through use of a multidetector-row CT, which reduces motion blur and therefore produces accurate coronal and sagittal reconstructions. Furthermore, reconstructive three-dimensional CT images gained from planar views, allows a better understanding of the spatial relationship of the fracture with other anatomical landmarks. This ensures a better appreciation of the severity and classification of a mandibular fracture, which therefore influences operative planning. Ultrasound is another useful modality in detecting a mandibular fracture when the patient is too unstable to be transferred to a CT scanner. The sensitivity however is less in comparison to a CT series of images and provides limited detail on the fracture pattern. Magnetic resonance imaging demonstrates use in assessing soft tissue injury of the temporomandibular joint but this is unlikely to be of priority when initially assessing a trauma patient. PMID:28932703

Initial Experience of US Marine Corps Forward Resuscitative Surgical System during Operation Iraqi Freedom

DTIC Science & Technology

2005-01-01

lavage, and splinting. Exter- nal fixation was used when there was concurrent vascular pro- cedures or if fractures were extremely unstable...foot open fracture Completion lower extremity amputation; completion right upper amputation; external fixation right ankle 8/Iraqi child Class 3 shock...infection Comminuted mandible fracture with loss of airway (casualty 1 in Table 2) Airway control Infection of mandibular plate at echelon 5 facility

The United States Army Medical Department Journal. July-September 2010

DTIC Science & Technology

2010-09-01

or Flail chest Respiratory rate < 10 or > 29 with distress, or Bilateral femur fractures GCS motor score  5 Unstable pelvis or suspected...significant pelvic fracture Paralysis or evidence of spinal cord injury Amputation above the wrist or ankle Significant burns Unreactive or...emphasis is on the individual who is failing to show signs of improvement in the immediate postinjury phase. Suspected skull fracture , especially with

The effect of early operative stabilization on late displacement of zone I and II sacral fractures.

PubMed

Emohare, Osa; Slinkard, Nathaniel; Lafferty, Paul; Vang, Sandy; Morgan, Robert

2013-02-01

This study was designed to evaluate the effect on displacement of early operative stabilization on unstable fractures when compared to stable fractures of the sacrum. Patient consisted of those sustaining traumatic pelvic fractures that also included sacral fractures of Denis type I and type II classification, who were over 18 at the time of the study. Patients were managed emergently, as judged appropriate at the time and then subsequently divided into two cohorts, comprising those who were either treated operatively or non-operatively. The operative group comprised those treated with either internal fixation or external fixation. Twenty-eight patients had zone II fractures, and 20 had zone I fractures. Zone II fractures showed average displacements of 6.5mm and 6.9mm in the rostral-caudal and anteroposterior directions, respectively, at final follow up. Zone I fractures had average displacements of 6.6mm and 6.1mm in both directions. There were no significant differences between zone I and II sacral fractures (rostral-caudal P=0.74, anteroposterior P=0.24). Average changes in fracture displacement in patients with zone I fractures were 0.6-1.0mm in both directions. Average changes in zone II fractures were 1.8-1.5mm in both directions. There were no significant differences between the average changes in zone I and II fractures in any direction (rostral-caudal P=0.64, anteroposterior P=0.68) or in average displacements at final follow up in any of zone or the entire cohort. Statistically significant differences were noted in average changes in displacement in zone II fractures in the anteroposterior plane (P=0.03) and the overall cohort in the anteroposterior plane (P=0.02). Operative fixation for unstable sacral fractures ensures displacement at follow up is comparable with stable fractures treated non operatively. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comparison of the quasi-static method and the dynamic method for simulating fracture processes in concrete

NASA Astrophysics Data System (ADS)

Liu, J. X.; Deng, S. C.; Liang, N. G.

2008-02-01

Concrete is heterogeneous and usually described as a three-phase material, where matrix, aggregate and interface are distinguished. To take this heterogeneity into consideration, the Generalized Beam (GB) lattice model is adopted. The GB lattice model is much more computationally efficient than the beam lattice model. Numerical procedures of both quasi-static method and dynamic method are developed to simulate fracture processes in uniaxial tensile tests conducted on a concrete panel. Cases of different loading rates are compared with the quasi-static case. It is found that the inertia effect due to load increasing becomes less important and can be ignored with the loading rate decreasing, but the inertia effect due to unstable crack propagation remains considerable no matter how low the loading rate is. Therefore, an unrealistic result will be obtained if a fracture process including unstable cracking is simulated by the quasi-static procedure.

New-type steel plate with ultra high crack-arrestability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishikawa, T.; Nomiyama, Y.; Hagiwara, Y.

1995-12-31

A new-type steel plate has been developed by controlling the microstructure of the surface layers. The surface layer consists of ultra fine grain ferrite microstructure, which provides excellent fracture toughness even at cryogenic temperature. When an unstable brittle crack propagates in the developed steel plate, shear-lips can be easily formed due to the surface layers with ultra fine grain microstructure. Since unstable running crack behavior is strongly affected by side-ligaments (shear-lips), which are associated with extensive plastic deformation, enhanced formation of the shear-lips can improve crack arrestability. This paper describes the developed steel plates of HT500MPa tensile strength class formore » shipbuilding use. Fracture mechanics investigations using large-scale fracture testings (including ultrawide duplex ESSO tests) clarified that the developed steel plates have ultra high crack-arrestability. It was also confirmed that the plates possess sufficient properties, including weldability and workability, for ship building use.« less

Intramedullary osteosynthesis versus plate osteosynthesis in subtrochanteric fractures.

PubMed

Burnei, C; Popescu, Gh; Barbu, D; Capraru, F

2011-11-14

Due to an ever-aging population and a growing prevalence of osteoporosis and motor vehicle accidents, the number of subtrochanteric fractures is increasing worldwide. The choice of the appropriate implant continues to be critical for fixation of unstable hip fractures. The subtrochanteric region has certain anatomical and biomechanical features that can make fractures in this region difficult to treat. The preferred type of device is a matter of debate. Increased understandings of biomechanical characteristics of the hip and improvement of the implant materials have reduced the incidence of complications. The surgeons choose between the two methods according to Seinsheimer's classification and also to their personal preferences. As a general principle, the open reduction and internal fixation were performed in stable fractures, and the closed reduction and internal fixation were performed in unstable fractures. The advantages of intramedullary nailing consist in a small skin incision, lower operating times, preservation of fracture hematoma and the possibility of early weight bearing. The disadvantages consist in a difficult closed reduction due to important muscular forces, although the nail can be used as a reduction instrument, and higher implant cost. In open reduction internal fixation techniques, the advantage is represented by anatomical reduction which, in our opinion, is not necessary. The disadvantages are represented by: higher operating time, demanding surgery, large devascularization, higher infection rates, late weight bearing, medial instability, refracture after plate removal and inesthetic approach.

Intramedullary osteosynthesis versus plate osteosynthesis in subtrochanteric fractures

PubMed Central

Burnei, C; Popescu, Gh; Barbu, D; Capraru, F

2011-01-01

Due to an ever-aging population and a growing prevalence of osteoporosis and motor vehicle accidents, the number of subtrochanteric fractures is increasing worldwide. The choice of the appropriate implant continues to be critical for fixation of unstable hip fractures. The subtrochanteric region has certain anatomical and biomechanical features that can make fractures in this region difficult to treat. The preferred type of device is a matter of debate. Increased understandings of biomechanical characteristics of the hip and improvement of the implant materials have reduced the incidence of complications. The surgeons choose between the two methods according to Seinsheimer's classification and also to their personal preferences. As a general principle, the open reduction and internal fixation were performed in stable fractures, and the closed reduction and internal fixation were performed in unstable fractures. The advantages of intramedullary nailing consist in a small skin incision, lower operating times, preservation of fracture hematoma and the possibility of early weight bearing. The disadvantages consist in a difficult closed reduction due to important muscular forces, although the nail can be used as a reduction instrument, and higher implant cost. In open reduction internal fixation techniques, the advantage is represented by anatomical reduction which, in our opinion, is not necessary. The disadvantages are represented by: higher operating time, demanding surgery, large devascularization, higher infection rates, late weight bearing, medial instability, refracture after plate removal and inesthetic approach. PMID:22514563

A novel fixation system for sacroiliac dislocation fracture: internal fixation system design and biomechanics analysis.

PubMed

Dawei, Tian; Na, Liu; Jun, Lei; Wei, Jin; Lin, Cai

2013-02-01

Although there were many different types of fixation techniques for sacroiliac dislocation fracture, the treat remained challenging in posterior pelvic ring injury. The purpose of this study was to evaluate the biomechanical effects of a novel fixation system we designed. 12 human cadavers (L3-pelvic-femora) were used to compare biomechanical stability after reconstruction on the same specimens in four conditions: (1) intact, (2) cable system, (3) plate-pedicle screw system, and (4) cable system and plate-pedicle screw combination system (combination system). Biomechanical testing was performed on a material testing machine for evaluating the stiffness of the pelvic fixation construct in compression and torsion. The cable system and plate-pedicle screw system alone may be insufficient to resist vertical shearing and rotational loads; however the combination system for unstable sacroiliac dislocation fractures provided significantly greater stability than single plate-pedicle or cable fixation system. The novel fixation system for unstable sacroiliac dislocation fractures produced sufficient stability in axial compression and axial rotation test in type C pelvic ring injuries. It may also offer a better solution for sacroiliac dislocation fractures. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Complications of treatment of acromioclavicular joint dislocation and unstable distal clavicular fracture with clavicular hook plate].

PubMed

Zhu, Yi-Yong; Cui, Heng-Yan; Jiang, Pan-Qiang; Wang, Jian-Liang

2013-11-01

To investigate the causes and prevention of the complications about treatment of acromioclavicular joint dislocation (Tossy III) and unstable distal clavicular fracture (Neer II) with clavicular hook plate. From January 2001 to December 2011, 246 patients with acromioclavicular joint dislocation (Tossy III) and 222 patients with unstable distal clavicular fracture (Neer II) were treated with acromioclvicular hook plate fixation,including 348 males and 120 females with an average age of 45.4 years old ranging from 21 to 80 years old. The mean time from injury to operation was 30.8 hours (ranged from 1 h to 15 d). All patients had normal shoulder function before injury. According to Karlsson evaluation standard, the cases with excellent and good function of the shoulder joint were regarded as the normal group, and the cases with poor function of shoulder joint as the abnormal group. The comparison of the range of forward flexion,backward stretch, adduction, abduction and elevation of shoulder joints between two groups was performed. The data of impingement, subacromial osteolysis, acromioclavicular arthritis, clavicular stress fracture, downward acromioclavicular joint subluxation, hook cut-out and hook break were summarized. All patients were followed up from 8 to 48 months with an average of 12.5 months. The results were excellent in 308 cases,good in 76,and poor in 84 according to Karlsson evaluation. The excellent and good rate was 82.1%. The difference of the range of forward flexion, backward stretch, adduction, abduction and elevation of shoulder joints between two groups had a statistically significant difference (P < 0.01). Among 84 poor cases, there were 41 (8.76%) in acromial impingement or inadequate place of plate hook, 12 (2.56%) with subacromial osteolysis or/and bursitis, 10 (2.14%) with acromioclavicular arthritis or painful shoulder caused by delayed dirigation,7 (1.50%) with clavicular stress fracture or interal plate upward, 6 (1.28%) with downward acromioclavicular joint subluxation, 5 (1.07%) with hook cut -out and 3 (0.64%) in hook break. The clavicular hook plate is useful for the treatment of acromioclavicular joint dislocation (Tossy III) and unstable distal clavicular fracture (Neer II). The correct place and suitable preflex of plate hook,the restoration of fiber structure around the acromioclavicular joint and the advisable dirigation contribute to the modified rate of complications.

Percutaneous vertebroplasty at C2: case report of a patient with multiple myeloma and a literature review

PubMed Central

Blimark, Cecilie; Willén, Jan; Mellqvist, Ulf-H; Rödjer, Stig

2006-01-01

Percutaneous vertebroplasty (PVP) of the axis is a challenging procedure which may be performed by a percutaneous or a transoral approach. There are few reports of PVP at the C2 level. We report a case of unstable C2 fracture treated with the percutaneous approach. The fracture was the first manifestation of multiple myeloma in a previously healthy 47-year-old woman. After local radiotherapy and chemotherapy, the fracture was still unstable and the patient had been continuously wearing a stiff cervical collar for 9 months. Complication-free PVP resulted in pain relief and stabilization and use of the cervical collar could be discontinued. At 18 months follow-up the patient remained free from pain, the fracture was stable and she had returned to work. The purpose of this article is to present the technical facts and to highlight the benefits and potential complications of the procedure. The technical characteristics of the procedure, the indication and results of the present case are discussed together with previously reported cases of PVP treatment at C2. PMID:17160394

Radiographic diagnosis of sagittal plane rotational displacement in pelvic fractures: a cadaveric model and clinical case study.

PubMed

Shui, Xiaolong; Ying, Xiaozhou; Kong, Jianzhong; Feng, Yongzeng; Hu, Wei; Guo, Xiaoshan; Wang, Gang

2015-08-01

Our objective was to measure the sagittal plane rotational (flexion and extension) displacement of hemipelvis radiologically and analyze the ratio of flexion and extension displacement of unstable pelvic fractures. We used 8 cadaveric models to study the radiographic evidence of pelvic fractures in the sagittal plane. We performed pelvic osteotomy on 8 cadavers to simulate anterior and posterior pelvic ring injury. Radiological data were measured in the flexion and extension group under different angles (5°, 10°, 15°, 20°, and 25°). We retrospectively reviewed 164 patients who were diagnosed with a unilateral fracture of the pelvis. Pelvic ring displacement was identified and recorded radiographically in cadaveric models. The flexion and extension displacement of pelvic fractures was measured in terms of the vertical distance of fracture from the top of iliac crest to the pubic tubercle (CD) or from the top of iliac crest to the lowest point of ischial tuberosity (AB). Fifty-seven pelves showed flexion displacement and 15 showed extension displacement. Closed reduction including internal fixation and external fixation was successfully used in 141 cases (86.0 %). The success rates of closed reduction in flexion and extension displacement groups were 77 and 73 %, respectively, which were lower than in unstable pelvic ring fractures. The sagittal plane rotation (flexion and extension) displacement of pelvic fractures could be measured by special points and lines on the radiographs. Minimally invasive reduction should be based on clearly identified differences between the sagittal plane rotation and the vertical displacement of pelvic fractures.

Open unstable metaphyseo-diaphyseal fractures of the tibia in adolescents: treatment by flexible intramedullary nails augmented by external fixator.

PubMed

Atef, Ashraf; El Tantawy, Ahmad

2015-05-01

The treatment of open and unstable metaphyseo-diaphyseal fractures of the tibia in adolescents is challenging. It is important to choose a fixation method that can maintain alignment, allow wound care and not violate the growth plate. The aim of this work was to evaluate the efficacy of using flexible intramedullary nails (FIN) augmented by external fixator (EF) in the management of such fractures. A total of 26 males, with a mean age of 14.08 years and average body weight of 49.8 kg, presented with open metaphyseo-diaphyseal tibial fractures. All cases were treated using FIN augmented by mono-lateral EF. The fractures were located at the upper third in 17 cases and at the lower third in nine cases. The fracture pattern was spiral in eight cases, oblique in seven and multi-fragmentary in 11. The results were evaluated according to the scoring system for femoral TENs. All fractures united primarily after an average eight to 12 weeks with no evident angular deformity or limb-length discrepancy. None of the cases required cast immobilization or revision procedure. Twenty patients had excellent results, six patients showed good results and none had poor results. Fracture characteristics as well as patients' characteristics had no statistically significant effect (p > 0.005) on the final end results. The use of FIN augmented by EF is a good alternative in the management of open metaphyseo-diaphyseal tibial fractures in adolescents. This fixation provides more stability, allows easy access to the wound and early patients' ambulation.

[Ender nailing in fractures of the proximal femur. II. Analysis of our cohort].

PubMed

Bartonícek, J

1989-12-01

The work presents the analysis of the group of 172 patients with the fracture of the proximal femur treated by the technique of Ender nailing between June 1985 and December 1988. The group comprised 45 male (26 per cent) and 127 female (74 per cent) patients. Their average age was 76 years (ranging from 20 to 97 years of age) out of which 75 per cent of patients were older than 70 years and 40 per cent older than 80 years. Indication of Ender nailing in patients under 60 years of age we consider exceptional. In our group we operated on in total 14 patients under 60 years of age (ranging from 20 to 57 years of age) and namely in case of the comminuted type of fracture increased risk of infection or serious total condition. The whole group was operated on by 21 variously experienced surgeons. 147 operations were performed in the general anesthesia and 25 in the epidural one. The fractures of the proximal femur were divided into basicervical--10 (6 per cent), stable pertrochanteric 96 (56 per cent), unstable pertrochanteric--38 (22 per cent), per-subtrochanteric--19 (11 per cent) and subtrochanteric--9 (5 per cent). For the objective evaluation we compared our classification of the fracture of the trochanteric part with these of Evens, Kyle and Jensen. For stable fractures we considered the types I and II according to Kyle, for unstable the type III of Kyle classification. Per-subtrochanteric fractures (Kyle IV) we singled out for their seriousness as a separate group of unstable pertrochanteric fractures. Almost the same spectrum of fractures was in the group of 108 patients in which we evaluated longterm results. The minimum observence period was 3 months the mean period 6.3 months. Almost all patients from this group were followed up until complete healing. The mean duration of operation was 52 minutes, the mean duration of anesthesia was 81 minutes and the duration of X-ray exposure was 2.6 minutes. These data were calculated also for individual types of fractures. In this case the time intervals differed according to the seriousness of the fracture. The comparison of our time data with other authors reliably evaluating the results of Ender nailing has proved that it is necessary to free this intervention from the myth of a quick and easy operation. The average number of nails inserted in one patient was 3.6.(ABSTRACT TRUNCATED AT 400 WORDS)

Correlation between radiological parameters and patient-rated wrist dysfunction following fractures of the distal radius.

PubMed

Karnezis, I A; Panagiotopoulos, E; Tyllianakis, M; Megas, P; Lambiris, E

2005-12-01

The present study investigates the correlation between radiological parameters of wrist fractures and the clinical outcome expressed by objective clinical parameters and the level of patient-rated wrist dysfunction. Thirty consecutive cases of unstable distal radial fractures treated with closed reduction and percutaneous fixation were prospectively studied for a period of one year. The outcome parameters included objective clinical and radiological parameters and the previously described and validated patient-rated wrist evaluation (PRWE) score. Analysis showed that for unstable (AO classification types 23-A2, -A3, -C1 and -C2) fractures the fracture type affects the range of wrist palmarflexion (p=0.04) and that the presence of postoperative articular 'step-off' affects the range of wrist dorsiflexion and the patient-rated wrist function at the final time of the study (p<0.01 and p=0.02, respectively). It is also shown that permanent radial shortening and loss of the palmar angle were associated with prolonged wrist pain (p<0.01 and p=0.03, respectively). Our finding that residual articular incongruity correlates with persisting loss of wrist dorsiflexion and wrist dysfunction contradicts the view that loss of articular congruity is associated with late development of articular degeneration but not with early wrist dysfunction. Additionally, this study failed to show any association between the fracture type and the functional outcome as rated by the patients.

Mortality Rates Following Posterior C1-2 Fusion for Displaced Type II Odontoid Fractures in Octogenarians.

PubMed

Clark, Stephen; Nash, Alysa; Shasti, Mark; Brown, Luke; Jauregui, Julio J; Mistretta, Katherine; Koh, Eugene; Banagan, Kelley; Ludwig, Steven; Gelb, Daniel

2018-03-13

Retrospective cohort study OBJECTIVE.: To assess 30-day and one-year mortality rates as well as the most common complications associated with posterior C1-2 fusion in an octogenarian cohort. Treatment of unstable type II odontoid fractures in elderly patients can present challenges. Recent evidence indicates in patients older than 80 years, posterior C1-2 fusion results in improved survival as compared to other modes of treatment. Retrospective analysis of 43 consecutive patients (25 F and 18 M; mean age 84.3y, range 80-89y; mean Charlson Comorbidities Index 1.4, (range 1-6); mean BMI 24.8 ± 4.2 kg/m2, who underwent posterior C1-C2 fusion for management of unstable type II odontoid fracture by 4 fellowship trained spine surgeons at a single institution between January 2006-June 2016. Mean fracture displacement was 5.1 ± 3.6 mm and mean absolute value of angulation was 19.93 ± 12.93°. The most common complications were altered mental status (41.9%, n = 18), dysphagia (27.9%, n = 12) with 50% of those patients (6 of 12) requiring a feeding tube, and emergency reintubation (9.3%, n = 4). To the date of review completion, 25 of 43 patients expired (58.1%), median survival of 1.76 years from the date of surgery. Thirty-day and one-year mortality rates were 2.3% and 18.6%, respectively. Patients who developed dysphagia were 14.5 times more likely to have expired at 1 year; dysphagia was also found to be significantly associated with degree of displacement. Fracture displacement was found to be associated with increased odds for 1-year mortality when accounting for age and requirement of a feeding tube. Posterior C1-2 fusion results in acceptably low mortality rates in octogenarians with unstable type II odontoid fractures when compared to non-operative management mortality rates in current literature. Initial fracture displacement is associated with higher mortality rate in this patient population. 4.

Thoracolumbar Chance fracture during a professional female soccer game: case report

PubMed Central

Gotfryd, Alberto Ofenhejm; Franzin, Fernando José; Hartl, Roger

2016-01-01

ABSTRACT We report a rare case of an unstable flexion-distraction spine fracture with ligament involvement that occurred during a professional female soccer game. There were no neurological déficit. The patient had a painful midline gap which suggested ligamentar injury that was not immediately recognized. Despite that, proper immobilization and referral to hospital for further evaluation avoided additional spinal cord damage. The patient underwent a monosegmental posterior instrumentation spine fusion and after 6 months returned to professional soccer activities. This paper alerts to the possibility of occurrence of severe and unstable spine injuries during soccer practice and the importance of an adequate initial care at the game field in order to avoid iatrogenic neurological injuries. PMID:27074237

Additive fiber-cerclages in proximal humeral fractures stabilized by locking plates

PubMed Central

Hurschler, Christof; Rech, Louise; Vosshenrich, Rolf; Lill, Helmut

2009-01-01

Background and purpose The effect of additive fiber-cerclages in proximal humeral fractures stabilized by locking plates on fracture stabilization and rotator cuff function is unclear. Here it was assessed in a human cadaver study. Methods 24 paired human shoulder specimens were harvested from median 77-year-old (range 66–85) female donors. An unstable 3-part fracture model with an intact rotator cuff was developed. 1 specimen of each pair received an additive fiber-cerclage of the rotator cuff after plate fixation, and the other one received a plate fixation without an additive fiber-cerclage. Force-controlled hydraulic cylinders were used to simulate physiological rotator cuff tension, while a robot-assisted shoulder simulator performed 4 relevant cases of load: (1) axial loading at 0°, (2) glenohumeral abduction at 60°, (3) internal rotation at 0° abduction, and (4) external rotation at 0° abduction, and imitated hanging arm weight during loading without affecting joint kinematics. A 3-dimensional real-time interfragmentary motion analysis was done in fracture gaps between the greater tuberosity and the head, as well as subcapital. The capacity of the rotator cuff to strain was analyzed with an optical system. Results Interfragmentary motion was similar between the groups with and without fiber-cerclages, in both fracture gaps and in any of the cases of load. Cerclages did not impair the capacity of the rotator cuff to strain. Interpretation Provided that unstable 3-part fractures are reduced and stabilized anatomically by a locking plate, additive fiber-cerclages do not reduce interfragmentary motion. Additive fiber-cerclages may be necessary in locking plate osteosyntheses of multiple-fractured greater tuberosities or lesser tuberosity fractures that cannot be fixed sufficiently by the plate. PMID:19562564

Intra-Articular Entrapment of the Medial Epicondyle following a Traumatic Fracture Dislocation of the Elbow in an Adult

PubMed Central

Hassan, Youssef G.; Joukhadar, Nabih I.

2018-01-01

Medial epicondyle entrapment after an acute fracture dislocation of the elbow is a common finding in the pediatric population, but a rare finding in adults. We present a case of an adult patient diagnosed with a traumatic fracture dislocation of the elbow joint with intra-articular entrapment of the medial epicondyle. After initial evaluation, closed reduction was done. Stability testing after reduction showed an unstable joint; thus, open reduction and internal fixation was decided. PMID:29666736

Ductile fracture theories for pressurised pipes and containers

NASA Technical Reports Server (NTRS)

Erdogan, F.

1976-01-01

Two mechanisms of fracture are distinguished. Plane strain fractures occur in materials which do not undergo large-scale plastic deformations prior to and during a possible fracture deformation. Plane stress or high energy fractures are generally accompanied by large inelastic deformations. Theories for analyzing plane stress are based on the concepts of critical crack opening stretch, K(R) characterization, J-integral, and plastic instability. This last is considered in some detail. The ductile fracture process involves fracture initiation followed by a stable crack growth and the onset of unstable fracture propagation. The ductile fracture propagation process may be characterized by either a multiparameter (discrete) model, or some type of a resistance curve which may be considered as a continuous model expressed graphically. These models are studied and an alternative model is also proposed for ductile fractures which cannot be modeled as progressive crack growth phenomena.

Acute Pelvic Fractures: II. Principles of Management.

PubMed

Tile

1996-05-01

The past two decades have seen many advances in pelvic-trauma surgery. Provisional fixation of unstable pelvic-ring disruptions and open-book fractures with a pelvic clamp or an external frame with a supracondylar pin has proved markedly beneficial in the resuscitative phase of management. In the completely unstable pelvis, external clamps and frames can act only as provisional fixation and should be combined with skeletal traction. The traction pin is usually used only until a definitive form of stabilization can be applied to keep the pelvic ring in a reduced position. If the patient is too ill to allow operative intervention, the traction pin can remain in place with the external frame as definitive treatment. Symphyseal disruptions and medial ramus fractures should be plated at the time of laparotomy. Lateral ramus fractures can usually be controlled with external frames. A role has been suggested for percutaneous retrograde fixation of the superior pubic ramus; however, the benefits to be gained may not be enough to outweigh the serious risks of penetrating the hip, and this technique should therefore be used only by surgeons trained in its performance. The techniques for posterior fixation are becoming more standardized, but all still carry significant risks, especially to neurologic structures.

Reinforced cementoplasty using dedicated spindles in the management of unstable malignant lesions of the cervicotrochanteric region.

PubMed

Premat, Kévin; Clarençon, Frédéric; Bonaccorsi, Raphael; Degos, Vincent; Cormier, Évelyne; Chiras, Jacques

2017-09-01

In long bones, cementoplasty alone does not provide sufficient stability, which may cause secondary fractures. This study reviewed the safety and efficacy of reinforced cementoplasty (RC) (percutaneous internal fixation using dedicated spindles combined with cementoplasty) for unstable malignant lesions of the cervicotrochanteric region (CTR) of the proximal femur. Eighteen consecutive patients (nine women [50%] and nine men [50%]; mean age 55.1 ± 16.2 years; range 22-85) underwent RC for 19 unstable lesions of the CTR (16/19 [84.2%] bone metastases, 3/19 [15.8%] multiple myeloma lesions). All the patients were considered unsuitable for surgery. Clinical outcome was judged with a mean follow-up of 8.8 ± 7.2 months (range 1-27). The primary endpoints were occurrence of secondary fractures during the follow-up period and local pain relief measured by a visual analogue scale (VAS). No secondary fracture occurred. Mean VAS improved from 5.9 ± 3.1 (range 0-10) to 2.3 ± 2.4 (range 0-7) at 1 month (p = 0.001) to 1.6 ± 1.7 (range 0-5) at final follow-up (p = 0.0002). One symptomatic cement pulmonary embolism was recorded. RC is an original minimally invasive technique providing pain relief and effective bone stability for unstable malignant lesions of the cervicotrochanteric region in patients unsuitable for open surgery. • Reinforced cementoplasty (RC) combines intralesional spindling with cementoplasty. • RC provides effective bone stability and pain relief. • RC is a suitable minimally invasive option for patients in poor general condition.

Chromium content in the human hip joint tissues.

PubMed

Brodziak-Dopierała, Barbara; Kwapuliński, Jerzy; Sobczyk, Krzysztof; Wiechuła, Danuta

2015-02-01

Chromium has many important functions in the human body. For the osseous tissue, its role has not been clearly defined. This study was aimed at determining chromium content in hip joint tissues. A total of 91 hip joint samples were taken in this study, including 66 from females and 25 from males. The sample tissues were separated according to their anatomical parts. The chromium content was determined by the AAS method. The statistical analysis was performed with U Mann-Whitney's non-parametric test, P≤0.05. The overall chromium content in tissues of the hip joint in the study subjects was as follows: 5.73 µg/g in the articular cartilage, 5.33 µg/g in the cortical bone, 17.86 µg/g in the cancellous bone, 5.95 µg/g in the fragment of the cancellous bone from the intertrochanteric region, and 1.28 µg/g in the joint capsule. The chromium contents were observed in 2 group patients, it was 7.04 µg/g in people with osteoarthritis and 12.59 µg/g in people with fractures. The observed chromium content was highest in the cancellous bone and the lowest in the joint capsule. Chromium content was significantly different between the people with hip joint osteoarthritis and the people with femoral neck fractures. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Operative versus nonoperative treatment of unstable lateral malleolar fractures: a randomized multicenter trial.

PubMed

Sanders, David W; Tieszer, Christina; Corbett, Bradley

2012-03-01

To compare clinical and functional outcomes after operative and nonoperative treatment of undisplaced, unstable, isolated fibula fractures. Randomized multicenter clinical trial. Six level 1 trauma centers. Eighty-one patients with undisplaced, unstable, isolated fibula fractures as confirmed by an external rotation stress examination demonstrating an increase in medial clear space to 5 mm or greater were followed for 12 months after treatment. Forty-one patients were treated operatively by open reduction and internal fixation of the fibula. Forty patients underwent nonoperative treatment, which included the use of a short leg cast or brace and protected weight bearing for 6 weeks. Functional outcomes determined using the Olerud-Molander Ankle Score and the Short Form 36. Radiographic outcomes included measurement of union and displacement at each visit. There were no statistically significant differences in functional outcome scores or pace of recovery between the operative and nonoperative groups at any time interval (β = -0.28, 3.49; P = 0.936). Complications in the nonoperative group included 8 patients with a medial clear space ≥5 mm and 8 patients with delayed union or nonunion. In the operative group, 5 patients had a surgical site infection and 5 patients required hardware removal. Patients managed operatively had equivalent functional outcomes compared with nonoperative treatment; however, the risk of displacement and problems with union was substantially lower in patients managed with surgery.

A statistical model of brittle fracture by transgranular cleavage

NASA Astrophysics Data System (ADS)

Lin, Tsann; Evans, A. G.; Ritchie, R. O.

A MODEL for brittle fracture by transgranular cleavage cracking is presented based on the application of weakest link statistics to the critical microstructural fracture mechanisms. The model permits prediction of the macroscopic fracture toughness, KI c, in single phase microstructures containing a known distribution of particles, and defines the critical distance from the crack tip at which the initial cracking event is most probable. The model is developed for unstable fracture ahead of a sharp crack considering both linear elastic and nonlinear elastic ("elastic/plastic") crack tip stress fields. Predictions are evaluated by comparison with experimental results on the low temperature flow and fracture behavior of a low carbon mild steel with a simple ferrite/grain boundary carbide microstructure.

Basic principles of fracture treatment in children.

PubMed

Ömeroğlu, Hakan

2018-04-01

This review aims to summarize the basic treatment principles of fractures according to their types and general management principles of special conditions including physeal fractures, multiple fractures, open fractures, and pathologic fractures in children. Definition of the fracture is needed for better understanding the injury mechanism, planning a proper treatment strategy, and estimating the prognosis. As the healing process is less complicated, remodeling capacity is higher and non-union is rare, the fractures in children are commonly treated by non-surgical methods. Surgical treatment is preferred in children with multiple injuries, in open fractures, in some pathologic fractures, in fractures with coexisting vascular injuries, in fractures which have a history of failed initial conservative treatment and in fractures in which the conservative treatment has no/little value such as femur neck fractures, some physeal fractures, displaced extension and flexion type humerus supracondylar fractures, displaced humerus lateral condyle fractures, femur, tibia and forearm shaft fractures in older children and adolescents and unstable pelvis and acetabulum fractures. Most of the fractures in children can successfully be treated by non-surgical methods.

A Biomechanical Comparison of Distal Fixation for Bridge Plating in a Distal Radius Fracture Model.

PubMed

Alluri, Ram K; Bougioukli, Sofia; Stevanovic, Milan; Ghiassi, Alidad

2017-09-01

To compare the biomechanical properties of second versus third metacarpal distal fixation when using a radiocarpal spanning distraction plate in an unstable distal radius fracture model. Biomechanical evaluation of the radiocarpal spanning distraction plate comparing second versus third metacarpal distal fixation was performed using a standardized model of an unstable wrist fracture in 10 matched-pair cadaveric specimens. Each fixation construct underwent a controlled cyclic loading protocol in flexion and extension. The resultant displacement and stiffness were calculated at the fracture site. After cyclic loading, each specimen was loaded to failure. The stiffness, maximum displacement, and load to failure were compared between the 2 groups. Cyclic loading in flexion demonstrated that distal fixation to the third metacarpal resulted in greater stiffness compared with the second metacarpal. There was no significant difference between the 2 groups with regards to maximum displacement at the fracture site in flexion. Cyclic loading in extension demonstrated no significant difference in stiffness or maximum displacement between the 2 groups. The average load to failure was similar for both groups. Fixation to the third metacarpal resulted in greater stiffness in flexion. All other biomechanical parameters were similar when comparing distal fixation to the second or third metacarpal in distal radius fractures stabilized with a spanning internal distraction plate. The treating surgeon should choose distal metacarpal fixation primarily based on fracture pattern, alignment, and soft tissue integrity. If a stiffer construct is desired, placement of the radiocarpal spanning plate at the third metacarpal is preferred. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Image-Guided Internal Fixation of an Oblique Sagittal Split Fracture of C1 Lateral Mass with Motion Preservation: A Technical Report.

PubMed

Malcolm, James G; Tan, Lee A; Johnson, Andrew K

2017-07-20

A sagittal split fracture of the C1 lateral mass is an unstable subtype of C1 fractures and has a high propensity for developing late deformities and pain with nonoperative management. A primary internal fixation of this type of fracture has been recently described with good clinical outcomes and preservation of motion. We present a modified technique of primary internal fixation using an obliquely inserted C1 lag screw with imaging guidance. We successfully treated a 55-year-old woman with a unilateral C1 oblique sagittal split fracture who failed nonoperative management. Technical nuances are discussed with a review of pertinent literature.

Does the Angle of the Nail Matter for Pertrochanteric Fracture Reduction? Matching Nail Angle and Native Neck-Shaft Angle.

PubMed

Parry, Joshua A; Barrett, Ian; Schoch, Bradley; Yuan, Brandon; Cass, Joseph; Cross, William

2018-04-01

To determine whether fixation of pertrochanteric hip fractures with cephalomedullary nails (CMNs) with a neck-shaft angle (NSA) less than the native NSA affects reduction and lag screw cutout. Retrospective comparative study. Level I trauma center. Patients treated with a CMN for unstable pertrochanteric femur fractures (OTA/AO 31-A2.2 and 31-A2.3) between 2005 and 2014. CMN fixation. NSA reduction and lag screw cutout. Patients fixed with a nail angle less than their native NSA were less likely to have good reductions [17% vs. 60%, 95% confidence interval (CI), -63% to -18%; P = 0.0005], secondary to more varus reductions (41% vs. 10%, 95% CI, 9%-46%; P = 0.01) and more fractures with ≥4 mm of displacement (63% vs. 35%, 95% CI, 3%-49%; P = 0.03). The cutout was not associated with the use of a nail angle less than the native NSA (60% vs. 76%, 95% CI, -56% to 18%; P = 0.5), varus reductions (60% vs. 32%, 95% CI, -13% to 62%; P = 0.3), or poor reductions (20% vs. 17%, 95% CI, -24% to 44%; P = 1.0). The fixation of unstable pertrochanteric hip fractures with a nail angle less than the native NSA was associated with more varus reductions and fracture displacement but did not affect the lag screw cutout. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effect on dynamic mechanical stability and interfragmentary movement of angle-stable locking of intramedullary nails in unstable distal tibia fractures: a biomechanical study.

PubMed

Gueorguiev, Boyko; Wähnert, Dirk; Albrecht, Daniel; Ockert, Ben; Windolf, Markus; Schwieger, Karsten

2011-02-01

Unstable distal tibia fractures are challenging injuries that require surgery. Increasingly, intramedullary nails are being used. However, fracture site anatomy may cause distal-fragment stabilization and fixation problems and lead to malunion/nonunion. We studied the influence of angle-stable nail locking on fracture gap movement and other biomechanical parameters. Eight pairs of fresh human cadaver tibiae were used. The bone mineral density (BMD) was determined. All tibiae were nailed with a Synthes Expert tibial nail. Within each pair, one tibia was randomized to receive conventional locking screws; the other, angle-stable screws with sleeves. A 7-mm osteotomy was created 10 mm above the upper distal locking screw, to simulate an AO 42-A3 fracture. Biomechanical testing involved nondestructive mediolateral and anteroposterior pure bending, followed by cyclic combined axial and torsional loading to catastrophic failure. The neutral zone was determined. Fracture gap movement was monitored with 3-D motion tracking. The angle-stable locked constructs had a significantly smaller mediolateral neutral zone (mean: 0.04 degree; p=0.039) and significantly smaller fracture gap angulation (p=0.043). The number of cycles to failure did not differ significantly between the locking configurations. BMD was a significant covariate affecting the number of cycles to failure (p=0.008). However, over the first 20,000 cycles, there was no significant correlation in the angle-stable construct. Angle-stable locking of the Expert tibial nail was associated with a significant reduction in the mediolateral neutral zone and in fracture gap movement. Angle-stable fixation also reduced the influence of BMD over the first 20,000 cycles.

Surgical management of U-shaped sacral fractures: a systematic review of current treatment strategies.

PubMed

König, M A; Jehan, S; Boszczyk, A A; Boszczyk, B M

2012-05-01

U-shaped sacral fractures usually result from axial loading of the spine with simultaneous sacral pivoting due to a horizontal fracture which leads to a highly unstable spino-pelvic dissociation. Due to the rarity of these fractures, there is lack of an agreed treatment strategy. A thorough literature search was carried out to identify current treatment concepts. The studies were analysed for mechanism of injury, diagnostic imaging, associated injuries, type of surgery, follow-up times, complications, neurological, clinical and radiological outcome. Sixty-three cases were found in 12 articles. No Class I, II or III evidence was found in the literature. The most common mechanism of injury was a fall or jump from height. Pre-operative neurological deficit was noted in 50 (94.3%) out of 53 cases (not available in 10 patients). The most used surgical options were spino-pelvic fixation with or without decompression and ilio-sacral screws. Post-operative complications occurred in 24 (38.1%) patients. Average follow-up time was 18.6 months (range 2-34 months). Full neurological recovery was noted in 20 cases, partial recovery in 14 and 9 patients had no neurological recovery (5 patients were lost in follow-up). Fracture healing was mentioned in 7 articles with only 1 case of fracture reduction loss. From the current available data, an evidence based treatment strategy regarding outcome, neurological recovery or fracture healing could not be identified. Limited access and minimal-invasive surgery focussing on sacral reduction and restoration seems to offer comparable results to large spino-pelvic constructs with fewer complications and should be considered as the method of choice. If the fracture is highly unstable and displaced, spino-pelvic fixation might offer better stability.

A prospective study on 284 digital fractures of the hand.

PubMed

Pun, W K; Chow, S P; So, Y C; Luk, K D; Ip, F K; Chan, K C; Ngai, W K; Crosby, C; Ng, C

1989-05-01

We report a prospective study on 284 digital fractures of the hand in 235 patients. Management followed clear guidelines set out in a protocol. Important factors in the selection of the treatment method were, acceptable alignment, functional stability, and associated "significant" soft tissue injuries. "Functionally" stable fractures treated by free mobilization had satisfactory results. Unstable fractures treated by splints or Kirschner wire fixation produced unsatisfactory results. "Open fracture," "comminuted fracture," and "associated significant soft tissue injuries" were identified as unfavorable prognostic factors. The anatomic site of the fractures was not important in determining the final outcome. About 15% of the displaced fractures became functionally stable after closed reduction and their results were comparable with the undisplaced fractures. About 30% of the patients had various degrees of difficulty after they returned to work. About 14% of the patients eventually changed their jobs because of their residual disability.

Early Weightbearing and Range of Motion Versus Non-Weightbearing and Immobilization After Open Reduction and Internal Fixation of Unstable Ankle Fractures: A Randomized Controlled Trial.

PubMed

Dehghan, Niloofar; McKee, Michael D; Jenkinson, Richard J; Schemitsch, Emil H; Stas, Venessa; Nauth, Aaron; Hall, Jeremy A; Stephen, David J; Kreder, Hans J

2016-07-01

The aim of this study was to compare early weightbearing and range of motion (ROM) to nonweightbearing and immobilization in a cast after surgical fixation of unstable ankle fractures. Multicentre randomized controlled trial. Two-level one trauma centers. One hundred ten patients who underwent open reduction and internal fixation of an unstable ankle fracture were recruited and randomized. One of 2 rehabilitation protocols: (1) Early weightbearing (weightbearing and ROM at 2 weeks, Early WB) or (2) Late weightbearing (nonweightbearing and cast immobilization for 6 weeks, Late WB). The primary outcome measure was time to return to work (RTW). Secondary outcome measures included: ankle ROM, SF-36 heath outcome scores, Olerud/Molander ankle function score, and rates of complications. There was no difference in RTW. At 6 weeks postoperatively, patients in the Early WB group had significantly improved ankle ROM (41 vs. 29, P < 0.0001); Olerud/Molander ankle function scores (45 vs. 32, P = 0.0007), and SF-36 scores on both the physical (51 vs. 42, P = 0.008) and mental (66 vs. 54, P = 0.0008) components. There were no differences with regard to wound complications or infections and no cases of fixation failure or loss of reduction. Patients in the Late WB group had higher rates of planned/performed hardware removal due to plate irritation (19% vs. 2%, P = 0.005). Given the convenience for the patient, early improved functional outcome, and the lack of an increased complication rate, we recommend early postoperative weightbearing and ROM in patients with surgically treated ankle fractures. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Cervical spine immobilization may be of value following firearm injury to the head and neck.

PubMed

Schubl, Sebastian D; Robitsek, R Jonathan; Sommerhalder, Christian; Wilkins, Kimberly J; Klein, Taylor R; Trepeta, Scott; Ho, Vanessa P

2016-04-01

Penetrating injuries to the head and neck may not be able to cause unstable fractures without concomitant spinal cord injury, rendering prehospital spinal immobilization (PHSI) ineffectual, and possibly harmful. However, this premise is based on reports including predominantly chest and abdominal injuries, which are unlikely to cause cervical spine (CS) injuries. We performed a retrospective review of all patients presenting with a penetrating wound to the head or neck over a 4-year period at an urban, level 1 trauma center to determine if there was a benefit of PHSI. One hundred seventy-two patients were identified, of which 16 (9.3%) died prior to CS evaluation. Of 156 surviving patients, mechanism was gunshot wound (GSW) in 36 (28%) and stab wound (SW) in 120 (72%). Fifty-eight patients had PHSI placed (37%), and GSW patients' odds of having PHSI were greater than SW patients (OR 2.3; CI 1.08-4.9). Eight of 156 surviving patients eventually died (5.1%), and the odds of mortality were greater among those that had PHSI than those without (OR 5.54; CI 1.08-28.4). Six (3.8%; 5 GSW, 1 SW) patients had a CS fracture. Two GSW patients (5.6%) had unstable CS fractures with a normal neurological exam at initial evaluation. Of patients with a GSW to the head or neck that survived to be evaluated, 5.6% had unstable fractures without an initial neurologic deficit. PHSI may be appropriate in this population. Further studies are warranted prior to a determination that PHSI is unnecessary in penetrating head and neck injuries. Copyright © 2016 Elsevier Inc. All rights reserved.

Grain fracture model and its application to strength evaluation in engineering ceramics

NASA Astrophysics Data System (ADS)

Hoshide, Toshihiko

1993-02-01

A new model of cracking process in ceramics is developed assuming the fracture of the grain just ahead of a flaw, such as a crack or a notch, during the loading process, prior to the final unstable fracture. Based on the grain fracture model, a simulation was carried out to explain the anomalous behavior of small flaws and the notch width effect, which were reported by Evans and Langdon (1976) and Hoshide et al. (1984) and by Bertolotti (1973) and Pabst et al. (1982), respectively. It is shown that the analytical relations of the new model can explain the experimental results for both situations.

Lunate fractures and associated radiocarpal and midcarpal instabilities: a systematic review.

PubMed

Shunmugam, Meenalochani; Phadnis, Joideep; Watts, Amy; Bain, Gregory I

2018-01-01

The aim of this study was to analyse lunate fractures and any associated osseo-ligamentous injuries. A systematic review identified 34 cases. We identified carpal instabilities at the radiocarpal and midcarpal joints in volar and dorsal directions. Radiocarpal instabilities (10/34) were usually dorsoradial (8/10), with a transverse lunate fracture, best seen on a coronal image. Midcarpal instabilities (24/34) were usually volar (14/18), with a volar lunate shear fracture, best seen on a sagittal image. Instabilities were sub-classified into non-displaced, subluxated and dislocated. Associated fractures of the scaphoid and the radial and ulnar styloid processes were common. Lunate fractures without subluxation or dislocation had good outcomes with cast immobilization or fixation of associated fractures. Lunate fracture-subluxations are unstable injuries that are best managed with fixation of the carpal fractures. Lunate fracture-dislocations are complex injuries, requiring stabilization of the lunate, associated fractures and ligament injuries; complications are common and acute or delayed salvage procedures may be required.

Fall-Related Injuries in Community-Dwelling Older Adults in Qom Province, Iran, 2010-2012.

PubMed

Gilasi, Hamid Reza; Soori, Hamid; Yazdani, Shahram; Taheri Tenjani, Parisa

2015-03-01

Falls and related injuries are common health problems in the elderly. Fractures, brain and internal organ injuries and death are the common consequences of the falls, which result in dependence, decreased self-efficacy, fear of falling, depression, restricted daily activities, hospitalization and admission to the nursing home and impose costs on the individual and the society. The purpose of this study was to determine the types of fall-related injuries and the related risk factors in the elderly population of Qom province, Iran. This retrospective study was performed on 424 elderly people (65 years and over) referred to Shahid Beheshti Hospital, Qom, Iran, due to falls between 2010 and 2012. The ICD-10 codes of external causes of injury from w00 to w19 related to falls were selected from the health information system of the hospital and demographic variables of the patients and external causes of falls were extracted after accessing the files of the patients. Data were analyzed using SPSS version 18 (SPSS Inc., USA). The duration of hospital stay and its relationship with underlying variables were investigated using t test and ANOVA. The level of significance was considered P < 0.05. Among 424 elderly people, 180 cases (42.45%) were male and the mean age of the patients was 78.65 ± 7.70 years. Fall on the same level from slipping, tripping, and stumbling was the most common external cause with 291 victims (68.60%), and hip fracture in 121 patients (29.00%), intertrochanteric fracture in 112 patients (26.90%), and traumatic brain injury in 51 patients (12.20%) were the most common causes of hospital stay. The mean hospital stay was 7.33 ± 3.63 days. Lower limb fracture and traumatic brain injury were the most common causes of hospitalization, which resulted in the longest hospital stay and highest hospitalization costs in the elderly.

Pediatric mandibular fractures treated by rigid internal fixation.

PubMed

Wong, G B

1993-09-01

Mandibular fractures in the pediatric patient population are relatively uncommon. These patients present with their own unique treatment requirements. Most fractures have been treated conservatively by dental splints. Closed reduction techniques with maxillomandibular fixation (MMF) in very young children can pose several concerns, including cooperation, compliance and adequate nutritional intake. Rigid internal fixation of unstable mandibular fractures using miniplates and screws circumvents the need for MMF and allows immediate jaw mobilization. At major pediatric trauma institutions, there has been an increasing trend toward the use of this treatment when open reduction is necessary. This article presents a report of a five-year-old child who presented with bilateral mandibular fractures and was treated by rigid internal fixation and immediate mandibular mobilization.

Fractography of a bis-GMA resin.

PubMed

Davis, D M; Waters, N E

1989-07-01

The fracture behavior of a bis-GMA resin was studied by means of the double-torsion test. The fracture parameter measured was the stress-intensity factor. Fracture occurred in either a stick-slip (unstable) or continuous (stable) manner, depending upon the test conditions. When stick-slip propagation occurred, the fracture surfaces showed characteristic crack-arrest lines. The fracture surfaces were examined by use of a reflected-light optical microscope. The stress-intensity factor for crack initiation was found to be related to the size of the crack-arrest line which, in turn, could be related to the Dugdale model for plastic zone size. The evidence supported the concept that the behavior of the crack during propagation was controlled by the amount of plastic deformation occurring at the crack tip.

Image-Guided Internal Fixation of an Oblique Sagittal Split Fracture of C1 Lateral Mass with Motion Preservation: A Technical Report

PubMed Central

Malcolm, James G; Johnson, Andrew K

2017-01-01

A sagittal split fracture of the C1 lateral mass is an unstable subtype of C1 fractures and has a high propensity for developing late deformities and pain with nonoperative management. A primary internal fixation of this type of fracture has been recently described with good clinical outcomes and preservation of motion. We present a modified technique of primary internal fixation using an obliquely inserted C1 lag screw with imaging guidance. We successfully treated a 55-year-old woman with a unilateral C1 oblique sagittal split fracture who failed nonoperative management. Technical nuances are discussed with a review of pertinent literature. PMID:28948116

[Injuries of the cervical spine in patients with ankylosing spondylitis].

PubMed

Vaverka, M; Hrabálek, L

2001-01-01

A brittle and rigid, osteoporotic and injury prone "bamboo" spine which develops as a result of transformation of the normal spine in the final stage of Bekhterev's disease contains normal neural elements. Unstable fractures occur frequently even after a minimal injury and the morbidity and mortality is significantly higher than in the group of routine injuries of the cervical, spine, in particular as a result of pulmonary complications. Diagnosis of the fracture based on simple X-ray pictures is difficult, CT examination is essential. The authors present an account on their experience with three patients. They draw attention to problems of skeletal traction when the spinal axis is altered by disease and to risks associated with semiconservative treatment. The authors therefore recommend traction with a minimal load and with subsequent early decompression and stabilization by a combined anterior and posterior approach in a single session. By this approach secondary affection of neural structures in unstable fractures can be prevented, and early rehabilitation with verticalization without restriction of respiratory excursions by an orthesis then significantly reduces the risk of pulmonary complications.

[Complications of open reduction and internal fixation versus external fixation for unstable distal radius fractures: a meta-analysis].

PubMed

Yang, Z; Yuan, Z Z; Ma, J X; Ma, X L

2016-12-20

Objective: To make a systematic assessment of the complications of open reduction and internal fixation versus external fixation for unstable distal radius fractures. Method: A computer-based online search of PubMed, ScienceDirect, EMBASE, BIOSIS, Springer and Cochrane Library were performed.The randomized and controlled trials of open reduction and internal fixation versus external fixation for unstable distal radius fractures were collected.The included trials were screened out strictly based on the criterion of inclusion and exclusion.The quality of included trials was evaluated.RevMan 5.0 was used for data analysis. Result: A total of 17 studies involving 1 402 patients were included.There were 687 patients with open reduction and internal fixation and 715 with external fixation.The results of Meta-analysis indicated that there were statistically significant differences with regard to the postoperatively total complications, infection, malunion, tendon rupture ( I 2 =8%, RR =0.77(95% CI 0.65-0.91, Z =3.10, P <0.05). There were no statistically significant differences observed between two approaches with respect to nounion, re-operation, complex regional pain syndrome, carpal tunnel syndrome, neurapraxia, tendonitis, painful hardware, scar( P >0.05). Conclusion: Postoperative complications are present in both open reduction and internal fixation and external fixation.Compared with external fixation, open reduction and internal fixation is lower in total complications postoperatively, infection and malunion, but external fixation has lower tendon rupture incidence.

[Early operative treatment of pelvic fractures associated with urethral disruption].

PubMed

Jia, Jian; Guo, Lu-Zeng; Wu, Chang-Lin; Chen, Jia-Geng; Zhang, Tie-Liang; Pei, Fu-Xing

2007-02-15

To evaluate the early operative treatment and clinical results of pelvic fractures associated with urethra disruption. From January 1995 to January 2005, 25 patients suffered from pelvic fractures combined urethra disruption treated by operation were retrospectively analyzed. According to Tile's classification, 1 case was stable pelvic fracture, 17 rotational unstable fractures, and 7 rotational combined vertical unstable fractures. The complete urethra rupture were in 23 cases and incomplete in 2 cases. The operative methods included: (1) emergency open reduction and internal fixation of the pelvis combined primary urethra suturing in 2 cases, partial suturing after realignment in 4 cases, realignment in 2 cases, and urethrovaginal penetrating wound repairing in 1 case; (2) primary urethra realignment only and delayed (range, 7 to 21 days) pelvic internal fixation in 10 cases; (3) early cystostomy and delayed (range, 3 to 21 days) urethra realignment and pelvic internal fixation in 6 cases. The mean follow-up time of all patients was 34 months (range from 6 to 120 months). According to Majeed's evaluation, 17 cases of pelvic injury showed excellent results, 5 good, and 3 fare. After urinary catheter removed, the mean maximal urine flow rate of 19 (76%) patients was 18.6 ml/s and the mean scar length between both disrupted ends on the film of excretion urethrography was 0.51 cm. Five (20%) cases suffered in dysuria needed urethral dilatation or further surgery. One (4%) female could not control urination who need a second-look operation. The primary suprapubic soft tissue avulsion wound infection secondary to retropubic abscess was found in 1 case, posterior urethra-stenosis in 5 cases, sexual impotence in 3 cases, and incontinence in 1 case. The satisfactory reduction and effective fixation of the pelvic fractures is an anatomical basis for receiving "tension-free urethral anastomosis".

Weightbearing vs Gravity Stress Radiographs for Stability Evaluation of Supination-External Rotation Fractures of the Ankle.

PubMed

Seidel, Angela; Krause, Fabian; Weber, Martin

2017-07-01

Isolated lateral malleolar fractures may result from a supination-external rotation (SER) injury of the ankle. Stable fractures maintain tibiotalar congruence due to competent medial restraints and can be treated nonoperatively with excellent functional results and long-term prognosis. Stability might be assessed with either stress radiographs or weightbearing radiographs. A consecutive series of patients with closed SER fractures (presumed AO 44-B1) were prospectively enrolled from 2008 to 2015. Patients with clearly unstable fractures (medial clear space more than 7 mm) on the initial nonweightbearing radiograph were excluded and operated on. All other patients were examined with a gravity stress and a weightbearing anteroposterior radiograph. Borderline instability of the fracture was assumed when the medial clear space was 4 to 7 mm. Those were treated nonoperatively. Of 104 patients with isolated lateral malleolar fractures of the SER type, 14 patients were treated operatively because of clear instability (displacement) on the initial radiographs. Of the nonoperative patients, 44 patients demonstrated borderline instability on the gravity stress but stability on the weightbearing radiograph ("gravity borderline"); the remaining 46 were stable in both tests ("gravity stable"). At an average follow-up of 23 months, no significant differences were seen in the American Orthopaedic Foot & Ankle Society hindfoot score (92 points gravity-borderline group vs 93 points gravity-unstable group), the Foot Functional Index score (11 vs 10 points), the Short Form 36 (SF-36) physical component (86 vs 85 points), and SF-36 mental component (84 vs 81 points). Radiographically, all fractures had healed with anatomic congruity of the ankle. Weightbearing radiographs provided a reliable basis to decide about stability and nonoperative treatment in isolated lateral malleolar fractures of the SER type with excellent clinical and radiographic outcome at short-term follow-up. Gravity stress radiographs appear to overrate the need for operative treatment. Level III, prospective comparative study.

3D printing-based minimally invasive cannulated screw treatment of unstable pelvic fracture.

PubMed

Cai, Leyi; Zhang, Yingying; Chen, Chunhui; Lou, Yiting; Guo, Xiaoshan; Wang, Jianshun

2018-04-04

Open reduction and internal fixation of pelvic fractures could restore the stability of the pelvic ring, but there were several problems. Minimally invasive closed reduction cannulated screw treatment of pelvic fractures has lots advantages. However, how to insert the cannulated screw safely and effectively to achieve a reliable fixation were still hard for orthopedist. Our aim was to explore the significance of 3D printing technology as a new method for minimally invasive cannulated screw treatment of unstable pelvic fracture. One hundred thirty-seven patients with unstable pelvic fractures from 2014 to 2016 were retrospectively analyzed. Based on the usage of 3D printing technology for preoperative simulation surgery, they were assigned to 3D printing group (n = 65) and control group (n = 72), respectively. These two groups were assessed in terms of operative time, intraoperative fluoroscopy, postoperative reduction effect, fracture healing time, and follow-up function. The effect of 3D printing technology was evaluated through minimally invasive cannulated screw treatment. There was no significant difference in these two groups with respect to general conditions, such as age, gender, fracture type, time from injury to operation, injury cause, and combined injury. Length of surgery and average number of fluoroscopies were statistically different for 3D printing group and the control group (p < 0.01), i.e., 58.6 vs. 72.3 min and 29.3 vs. 37 min, respectively. Using the Matta radiological scoring systems, the reduction was scored excellent in 21/65 cases (32.3%) and good in 30/65 cases (46.2%) for the 3D printing group, versus 22/72 cases (30.6%) scored as excellent and 36/72 cases (50%) as good for the control group. On the other hand, using the Majeed functional scoring criteria, there were 27/65 (41.5%) excellent and 26/65 (40%) good cases for the 3D printing group in comparison to 30/72 (41.7%) and 28/72 (38.9%) cases for the control group, respectively. This suggests no significant difference between these two groups about the function outcomes. Full reduction and proper fixation of the pelvic ring and reconstruction of anatomical morphology are of great significance to patients' early functional exercise and for the reduction of long-term complications. This retrospective study has demonstrated the 3D printing technology as a potential approach for improving the diagnosis and treatment of pelvic fractures. The study was retrospectively registered at the Chinese Clinical Trial Registry, number: ChiCTR-TRC-17012798, trial registration date: 26 Sept. 2017.

Biomechanical Concepts for Fracture Fixation

PubMed Central

Bottlang, Michael; Schemitsch, Christine E.; Nauth, Aaron; Routt, Milton; Egol, Kenneth; Cook, Gillian E.; Schemitsch, Emil H.

2015-01-01

Application of the correct fixation construct is critical for fracture healing and long-term stability; however, it is a complex issue with numerous significant factors. This review describes a number of common fracture types, and evaluates their currently available fracture fixation constructs. In the setting of complex elbow instability, stable fixation or radial head replacement with an appropriately sized implant in conjunction with ligamentous repair is required to restore stability. For unstable sacral fractures, “standard” iliosacral screw fixation is not sufficient for fractures with vertical or multiplanar instabilities. Periprosthetic femur fractures, in particular Vancouver B1 fractures, have increased stability when using 90/90 fixation versus a single locking plate. Far Cortical Locking combines the concept of dynamization with locked plating in order to achieve superior healing of a distal femur fracture. Finally, there is no ideal construct for syndesmotic fracture stabilization; however, these fractures should be fixed using a device that allows for sufficient motion in the syndesmosis. In general, orthopaedic surgeons should select a fracture fixation construct that restores stability and promotes healing at the fracture site, while reducing the potential for fixation failure. PMID:26584263

External fixation techniques for distal radius fractures.

PubMed

Capo, John T; Swan, Kenneth G; Tan, Virak

2006-04-01

Fractures of the distal radius are common injuries. Low-energy or high-energy mechanisms may be involved. Unstable distal radius fractures present a challenge to the treating orthopaedic surgeon. External fixation is a valuable instrument for fracture reduction and stabilization. Limited open incisions, early range of motion, and treatment of complex wounds are a few of the benefits of external fixation. Fixators may be spanning or nonbridging and may be used alone or in combination with other stabilization methods to obtain and maintain distal radius fracture reduction. Augmentation with percutaneous wires allows for optimal fracture stabilization with physiologic alignment of the wrist. Moderate distraction at the carpus does not induce postoperative stiffness. The distal radioulnar joint must be assessed and may need to be stabilized. Complications of external fixation are usually minor, but must be anticipated and treated early. Level V (expert opinion).

Dismounted Blast Injuries in Patients Treated at a Role 3 Military Hospital in Afghanistan: Patterns of Injury and Mortality.

PubMed

Oh, John S; Tubb, Creighton C; Poepping, Thomas P; Ryan, Paul; Clasper, Jonathan C; Katschke, Adrian R; Tuman, Caroline; Murray, Michael J

2016-09-01

The purposes of this study are to define the pattern of injuries sustained by dismounted troops exposed to improvised explosive devices blasts treated at a Role 3 combat support hospital and to assess injury patterns and mortality associated with the mechanism. Our hypothesis was that mortality is associated with pelvic fracture, massive transfusion, high Injury Severity Score (ISS), multiple limb amputations, and transfer from a Role 2 facility. Retrospective study of 457 patients. Analysis performed on trauma registry data and systematic review of radiographs. 99.9% were men with a median age of 23 years and median ISS 10. 141 patients (30.9%) required massive blood transfusion. Limb amputations were frequently observed injuries, 109 of 172 amputees (63.4%) had a double amputation. 34 subjects (7.4%) had pelvic fractures; majority of pelvic fractures (88%) were unstable (Tile B or C). Risk factors associated with the overall mortality rate of 1.8% were an ISS greater than 15 (odds ratio: 11.5; 95% confidence interval: 1.38, 533; p = 0.009), need for massive transfusion (p < 0.0001), and the presence of a pelvic fracture (odds ratio: 7.63; 95% confidence interval: 1.13, 41.3; p = 0.018). Dismounted improvised explosive devices blast injuries result in devastating multiple limb amputations and unstable pelvic fractures, which are associated with mortality after initial trauma resuscitation at a Role 3 hospital. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Intramedullary Percutaneous Fixation of Extra-Articular Proximal and Middle Phalanx Fractures.

PubMed

Jovanovic, Nebojsa; Aldlyami, Ehab; Saraj, Basem; Fm Seidam, Mohamed; Badawi, Hamed; Shaat, Ahmed; Alawadi, Khalid; Dodakundi, Chaitanya

2018-06-01

Multiple methods have been described for treating unstable proximal and middle phalangeal fractures. Irrespective of using an open or closed technique of fixation, stiffness and extensor lag at the proximal/distal interphalangeal joint almost always occur. This issue can be avoided by allowing the patients to mobilize the fingers out of plaster or splint as early as possible from the day of surgery. We describe a technique of intramedullary percutaneous fixation of extra-articular proximal and middle phalanx fractures allowing immediate mobilization of fingers, concurrent stabilization with progressive healing and thus preventing such complications.

Anesthetic Considerations of Sporadic Inclusion Body Myositis in an Elderly Man With Orthopedic Trauma.

PubMed

Steck, Dominik T; Choi, Christine; Gollapudy, Suneeta; Pagel, Paul S

2016-04-01

Sporadic inclusion body myositis (IBM) is an inflammatory myopathy characterized by progressive asymmetric extremity weakness, oropharyngeal dysphagia, and the potential for exaggerated sensitivity to neuromuscular blockers and respiratory compromise. The authors describe their management of a patient with IBM undergoing urgent orthopedic surgery. An 81-year-old man with IBM suffered a left intertrochanteric femoral fracture after falling down stairs. His IBM caused progressive left proximal lower extremity, bilateral distal upper extremity weakness (left > right), and oropharyngeal dysphagia (solid food, pills). He denied dyspnea, exercise intolerance, and a history of aspiration. Because respiratory insufficiency resulting from diaphragmatic dysfunction and prolonged duration of action of neuromuscular blockers may occur in IBM, the authors avoided using a neuromuscular blocker. After applying cricoid pressure, anesthesia was induced using intravenous lidocaine, propofol, remifentanil followed by manual ventilation with inhaled sevoflurane in oxygen. Endotracheal intubation was accomplished without difficulty; anesthesia was then maintained using remifentanil and sevoflurane. The fracture was repaired with a trochanteric femoral nail. The patient was extubated without difficulty and made an uneventful recovery. In summary, there is a lack of consensus about the use of neuromuscular blockers in patients with IBM. The authors avoided these drugs and were able to easily secure the patient's airway and maintain adequate muscle relaxation using a balanced sevoflurane-remifentanil anesthetic. Clinical trials are necessary to define the pharmacology of neuromuscular blockers in patients with IBM and determine whether use of these drugs contributes to postoperative respiratory insufficiency in these vulnerable patients.

[Selection of access and positioning for operative treatment of pelvic injuries. Decision-making strategies].

PubMed

Ossendorf, C; Hofmann, A; Rommens, P M

2013-03-01

Surgical treatment of pelvic ring injuries requires in-depth knowledge of the topographic anatomy of the pelvic bones, joints and soft tissue structures. A wide range of stabilizing techniques is available including bridging plate osteosynthesis, iliosacral compression screw osteosynthesis and transpubic positioning screws. In this article the different treatment strategies with the respective surgical approaches and patient positioning for pelvic ring fractures and combined lesions of the pelvic ring and acetabulum are presented. Pelvic ring lesions with rotational instability are approached from the anterior and occasionally from both the anterior and posterior based on the amount and localization of the instability. In vertically unstable lesions the most unstable part must be addressed first by reduction and fixation of the dislocated part to the axial skeleton. In combined fractures of the pelvis and acetabulum dorsal stabilization is carried out first.

The outcome of unstable proximal femoral fracture treated with reverse LISS plates.

PubMed

Lin, Shih-Jie; Huang, Kuo-Chin; Chuang, Po-Yao; Lee, Chien-Yin; Huang, Tsan-Wen; Lee, Mel S; Hsu, Robert Wen-Wei

2016-10-01

The Russel-Taylor type 2B fractures compromised the trochanteric region and medial buttress of proximal femur. This fracture pattern limits the choice of implants and raises the risk of adverse outcomes. We aimed to (i) determine the outcome of Russel-Taylor type 2B fractures treated using reverse less invasive stabilization system plates (LISS-DF) and to (ii) learn what factors affected outcomes after osteosynthesis with reverse LISS plates. A retrospective study SETTING: The study was conducted at a Level III trauma center in Taiwan. Twenty-five consecutive patients presenting with a Russel-Taylor type 2B fracture were enrolled. All cases were treated with reverse LISS plates. A Modified Radiographic Union Scale for Femur (RUSF), Radiographic parameters, functional scores, and complications were assessed. Union occurred in 21 cases at an average of 18.8 weeks. The average immediate postoperative neck-shaft angle was 130° (range: 122-135°) compared with 139° (range: 135-141°, p=0.05) on the contralateral side. Two cases had complications of proximal screws cutting out and two cases had broken implants. Finally, all 4 cases required repeated surgeries (16%). Malunion occurred in 4 patients and early mechanical failure (proximal screws cut out) occurred in 2. There was a significant difference in the purchase index of the proximal screws between cases with redisplacement and those without (26.4mm and 98.6mm, p=0.01). The use of reverse LISS plate appeared to be an alternative procedure for the specific pattern in the present study. We recommend using this reverse locking plate to treat unstable proximal femoral fractures with meticulous techniques of placing plates. Adequate purchase of the proximal locking screws might decrease the risks of complications. Copyright © 2016 Elsevier Ltd. All rights reserved.

PROSPECTIVE ASSESSMENT OF THE CLINICAL, RADIOGRAPHIC AND FUNCTIONAL EVOLUTION OF TREATMENT FOR UNSTABLE TROCHANTERIC FRACTURES OF THE FEMUR USING A CEPHALOMEDULLARY NAIL

PubMed Central

Borger, Richard Armelin; Borger, Frederico Araújo; Pires de Araújo, Rodrigo; Pereira, Thiago Ferreira Nunes; Queiroz, Roberto Dantas

2015-01-01

To assess the clinical, radiological and functional evolution of osteosynthesis using a cephalomedullary nail, in unstable trochanteric fractures of the femur, over a one-year postoperative follow-up. Methods: Fourteen men and 23 women of mean age 77.7 years were evaluated. Twenty-seven of them had fractures classified as AO/ASIF 31A2 and ten as 31A3. The patients were evaluated clinically, radiologically and functionally one week, two weeks, one month, two months, six months and one year after the operation. Results: The clinical complications comprised five cases of death, one case of calcaneal ulcer, one case of acute arterial obstruction and two cases of deep vein thrombosis. The radiographic evaluation showed that the mean cervicodiaphyseal angle in the immediate postoperative period was 132.5°. The mean tip-apex index was 22.8 mm. After one year, the mean cervicodiaphyseal angle was 131.7°. Fracture consolidation was seen in all the patients six months after the operation, except in one case that presented cut-out. There were no cases of fracture below the implant. The functional evaluation using the Harris score after one year showed a mean of 69.3 points. The evaluation of walking progress showed that after one year, 40.6% of the patients had the same ability to walk that they had before the fracture. The visual analogue pain scale showed that a significant decrease in pain complaints occurred, going from 5.19 in the first week to 2.25 after 1 year. Conclusion: Osteosynthesis using a cephalomedullary nail resulted in low rates of clinical and mechanical complications and adequate functional outcomes. PMID:27027025

PROSPECTIVE ASSESSMENT OF THE CLINICAL, RADIOGRAPHIC AND FUNCTIONAL EVOLUTION OF TREATMENT FOR UNSTABLE TROCHANTERIC FRACTURES OF THE FEMUR USING A CEPHALOMEDULLARY NAIL.

PubMed

Borger, Richard Armelin; Borger, Frederico Araújo; Pires de Araújo, Rodrigo; Pereira, Thiago Ferreira Nunes; Queiroz, Roberto Dantas

2011-01-01

To assess the clinical, radiological and functional evolution of osteosynthesis using a cephalomedullary nail, in unstable trochanteric fractures of the femur, over a one-year postoperative follow-up. Fourteen men and 23 women of mean age 77.7 years were evaluated. Twenty-seven of them had fractures classified as AO/ASIF 31A2 and ten as 31A3. The patients were evaluated clinically, radiologically and functionally one week, two weeks, one month, two months, six months and one year after the operation. The clinical complications comprised five cases of death, one case of calcaneal ulcer, one case of acute arterial obstruction and two cases of deep vein thrombosis. The radiographic evaluation showed that the mean cervicodiaphyseal angle in the immediate postoperative period was 132.5°. The mean tip-apex index was 22.8 mm. After one year, the mean cervicodiaphyseal angle was 131.7°. Fracture consolidation was seen in all the patients six months after the operation, except in one case that presented cut-out. There were no cases of fracture below the implant. The functional evaluation using the Harris score after one year showed a mean of 69.3 points. The evaluation of walking progress showed that after one year, 40.6% of the patients had the same ability to walk that they had before the fracture. The visual analogue pain scale showed that a significant decrease in pain complaints occurred, going from 5.19 in the first week to 2.25 after 1 year. Osteosynthesis using a cephalomedullary nail resulted in low rates of clinical and mechanical complications and adequate functional outcomes.

Percutaneous Intramedullary Screw Fixation of Distal Fibula Fractures: A Case Series and Systematic Review.

PubMed

Loukachov, Vladimir V; Birnie, Merel F N; Dingemans, Siem A; de Jong, Vincent M; Schepers, Tim

The current reference standard for unstable ankle fractures is open reduction and internal fixation using a plate and lag screws. This approach requires extensive dissection and wound complications are not uncommon. The use of intramedullary screw fixation might overcome these issues. The aim of our study was to provide an overview of the published data regarding intramedullary screw fixation of fibula fractures combined with a small consecutive case series. We performed a search of published studies to identify the studies in which fibula fractures were treated with percutaneous intramedullary screw fixation. Additionally, all consecutive patients treated for an unstable ankle fracture in a level 1 trauma center using an intramedullary screw were retrospectively included. The literature search identified 6 studies with a total of 180 patients. Wound infection was seen in 1 patient (0.6%), anatomic reduction was achieved in 168 patients (93.3%), and a loss of reduction was seen in 2 patients (1.1%). Implant removal was deemed necessary in 3 patients (1.7%) and nonunion was seen is 2 patients (1.1%). A total of 11 patients, in whom no wound complications occurred, were included in our study. The follow-up duration was a minimum of 12 months. A secondary dislocation was seen in 1 patient, and delayed union was observed after 7.5 months in 1 other patient. In conclusion, intramedullary screw fixation is a safe and adequate method to use for fibula fractures, with a low risk of wound complications. Additional research regarding functional outcome is warranted. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Progressive fracture of polymer matrix composite structures: A new approach

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Murthy, P. L. N.; Minnetyan, L.

1992-01-01

A new approach independent of stress intensity factors and fracture toughness parameters has been developed and is described for the computational simulation of progressive fracture of polymer matrix composite structures. The damage stages are quantified based on physics via composite mechanics while the degradation of the structural behavior is quantified via the finite element method. The approach account for all types of composite behavior, structures, load conditions, and fracture processes starting from damage initiation, to unstable propagation and to global structural collapse. Results of structural fracture in composite beams, panels, plates, and shells are presented to demonstrate the effectiveness and versatility of this new approach. Parameters and guidelines are identified which can be used as criteria for structural fracture, inspection intervals, and retirement for cause. Generalization to structures made of monolithic metallic materials are outlined and lessons learned in undertaking the development of new approaches, in general, are summarized.

Active and passive seismic methods for characterization and monitoring of unstable rock masses: field surveys, laboratory tests and modeling.

NASA Astrophysics Data System (ADS)

Colombero, Chiara; Baillet, Laurent; Comina, Cesare; Jongmans, Denis; Vinciguerra, Sergio

2016-04-01

Appropriate characterization and monitoring of potentially unstable rock masses may provide a better knowledge of the active processes and help to forecast the evolution to failure. Among the available geophysical methods, active seismic surveys are often suitable to infer the internal structure and the fracturing conditions of the unstable body. For monitoring purposes, although remote-sensing techniques and in-situ geotechnical measurements are successfully tested on landslides, they may not be suitable to early forecast sudden rapid rockslides. Passive seismic monitoring can help for this purpose. Detection, classification and localization of microseismic events within the prone-to-fall rock mass can provide information about the incipient failure of internal rock bridges. Acceleration to failure can be detected from an increasing microseismic event rate. The latter can be compared with meteorological data to understand the external factors controlling stability. On the other hand, seismic noise recorded on prone-to-fall rock slopes shows that the temporal variations in spectral content and correlation of ambient vibrations can be related to both reversible and irreversible changes within the rock mass. We present the results of the active and passive seismic data acquired at the potentially unstable granitic cliff of Madonna del Sasso (NW Italy). Down-hole tests, surface refraction and cross-hole tomography were carried out for the characterization of the fracturing state of the site. Field surveys were implemented with laboratory determination of physico-mechanical properties on rock samples and measurements of the ultrasonic pulse velocity. This multi-scale approach led to a lithological interpretation of the seismic velocity field obtained at the site and to a systematic correlation of the measured velocities with physical properties (density and porosity) and macroscopic features of the granitic cliff (fracturing, weathering and anisotropy). Continuous passive seismic monitoring at the site, from October 2013 to present, systematically highlighted clear energy peaks in the spectral content of seismic noise on the unstable sector, interpreted as resonant frequencies of the investigated volume. Both spectral analysis and cross-correlation of seismic noise showed seasonal reversible variation trends related to air temperature fluctuations. No irreversible changes, resulting from serious damage processes within the rock mass, were detected so far. Modal analysis and geomechanical modeling of the unstable cliff are currently under investigation to better understand the vibration modes that could explain the measured amplitude and orientation of ground motion at the first resonant frequencies. Classification and location of microseismic events still remains the most challenging task, due to the complex structural and morphological setting of the site.

Occipital Neuralgia after Occipital Cervical Fusion to Treat an Unstable Jefferson Fracture

PubMed Central

Kong, Seong Ju; Park, Jin Hoon

2012-01-01

In this report we describe a patient with an unstable Jefferson fracture who was treated by occipitocervical fusion and later reported sustained postoperative occipital neuralgia. A 70-year-old male was admitted to our center with a Jefferson fracture induced by a car accident. Preoperative lateral X-ray revealed an atlanto-dens interval of 4.8mm and a C1 canal anterior-posterior diameter of 19.94mm. We performed fusion surgery from the occiput to C5 without decompression of C1. The patient reported sustained continuous pain throughout the following year despite strong analgesics. The pain dermatome was located mainly in the great occipital nerve territory and posterior neck. Magnetic resonance images revealed no evidence of cord compression, however a C1 lamina compressed dural sac and C2 root compression could not be excluded. We performed bilateral C2 root decompression via a C1 laminectomy. After decompression, bilateral C2 root redundancy was identified by palpation. After decompression surgery, pain was reduced. This case indicates that occipital neuralgia, suggesting the need for diagnostic block, should be considered in the differential diagnosis of patients with sustained occipital headache after occipitocervical fusion surgery. PMID:25983846

The management of ankle fractures in patients with diabetes.

PubMed

Wukich, Dane K; Kline, Alex J

2008-07-01

Patients with diabetes mellitus have higher complication rates following both open and closed management of ankle fractures. Diabetic patients with neuropathy or vasculopathy have higher complication rates than both diabetic patients without these comorbidities and nondiabetic patients. Unstable ankle fractures in diabetic patients without neuropathy or vasculopathy are best treated with open reduction and internal fixation with use of standard techniques. Patients with neuropathy or vasculopathy are at increased risk for both soft-tissue and osseous complications, including delayed union and nonunion. Careful soft-tissue management as well as stable, rigid internal fixation are crucial to obtaining a good outcome. Prolonged non-weight-bearing and subsequently protected weight-bearing are recommended following both operative and nonoperative management of ankle fractures in patients with diabetes.

Modal and thermal analysis of Les Arches unstable rock column (Vercors massif, French Alps)

NASA Astrophysics Data System (ADS)

Bottelin, P.; Lévy, C.; Baillet, L.; Jongmans, D.; Guéguen, P.

2013-08-01

A potentially unstable limestone column (˜1000 m3, Vercors, French Alps) delineated by an open rear fracture was continuously instrumented with two three-component seismic sensors from mid-May 2009 to mid-October 2011. Spectral analysis of seismic noise allowed several resonance frequencies to be determined, ranging from 6 to 21 Hz. The frequency domain decomposition (FDD) technique was applied to the ambient vibrations recorded on the top of the rock column. Three vibration modes were identified at 6, 7.5 and 9 Hz, describing the upper part of corresponding modal shapes. Finite element numerical modelling of the column dynamic response confirmed that the first two modes are bending modes perpendicular and parallel to the fracture, respectively, while the third one corresponds to torsion. Seismic noise monitoring also pointed out that resonance frequencies fluctuate with time, under thermomechanical control. For seasonal cycles, changes in frequency are due to the variations of the bulk elastic properties with temperature. At daily scale, increase in fundamental frequency with temperature has been interpreted as resulting from the rock expansion inducing a closure of the rear fracture rock bridges, hence stiffening the contact between the column and the rock mass. Conversely, the rock contraction induces a fracture opening and a decrease in resonance frequency. In winter, when the temperature drops below 0 °C, a dramatic increase in fundamental frequency is observed from 6 Hz to more than 25 Hz, resulting from ice formation in the fracture. During spring, the resonance frequency gradually diminishes with ice melting to reach the value measured before winter.

Results of minimal invasive coracoclavicular fixation by double button lift-up system in Neer type II distal clavicle fractures.

PubMed

Dedeoğlu, Süleyman Semih; İmren, Yunus; Çabuk, Haluk; Çakar, Murat; Arslan, Samet Murat; Esenyel, Cem Zeki

2017-01-01

We aimed to evaluate clinical and functional outcomes of indirect fracture reduction performed by coracoclavicular fixation with minimal invasive double button lift-up system in Neer type IIa unstable fractures of distal clavicle. 22 patients with Neer type 2 distal clavicle fracture were enrolled in that prospective study. All patients underwent indirect reduction and osteosynthesis performed by coracoclavicular fixation with minimal invasive double button lift-up system. Postoperative follow-up was carried out clinically and radiologically with plain X-rays and utilization of Constant and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment (ASES) shoulder scores. Mean follow-up time was 15 months. A standard sling was applied for 2 weeks, postoperatively. Rehabilitation program was started on postoperative day 1. Mean age was 39 (range: 21-60), 18 of the patients were male. Right dominant extremity was affected in 14 patients. Mean duration of the surgical intervention was 40 min (range: 30-55 min). Mean union time was found to be 14 weeks (range: 7-21 weeks). Mean postoperative ASES and Constant scores were 79.9 (66.9-88.3) and 82.2 (71-100), respectively. The duration of return to normal daily activities were found to be 4.5 months. Any loss of reduction, AC joint arthrosis, and clavicular shortening were not detected in X-rays. This study has demonstrated that indirect osteosynthesis performed by coracoclavicular fixation with double button lift-up system in the treatment of unstable Neer type IIa fractures of the distal clavicle had successful clinical, radiological, and functional outcomes.

Pelvic ring injuries: Surgical management and long-term outcomes

PubMed Central

Halawi, Mohamad J.

2016-01-01

Pelvic ring injuries present a therapeutic challenge to the orthopedic surgeon. Management is based on the patient's physiological status, fracture classification, and associated injuries. Surgical stabilization is indicated in unstable injury patterns and those that fail nonsurgical management. The optimal timing for definitive fixation is not clearly defined, but early stabilization is recommended. Surgical techniques include external fixation, open reduction and internal fixation, and minimally invasive percutaneous osteosynthesis. Special considerations are required for concomitant acetabular fractures, sacral fractures, and those occurring in skeletally immature patients. Long-term outcomes are limited by lack of pelvis-specific outcome measures and burden of associated injuries. PMID:26908968

Progressive delamination in polymer matrix composite laminates: A new approach

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Murthy, P. L. N.; Minnetyan, L.

1992-01-01

A new approach independent of stress intensity factors and fracture toughness parameters has been developed and is described for the computational simulation of progressive delamination in polymer matrix composite laminates. The damage stages are quantified based on physics via composite mechanics while the degradation of the laminate behavior is quantified via the finite element method. The approach accounts for all types of composite behavior, laminate configuration, load conditions, and delamination processes starting from damage initiation, to unstable propagation, and to laminate fracture. Results of laminate fracture in composite beams, panels, plates, and shells are presented to demonstrate the effectiveness and versatility of this new approach.

[Fractures of the thoracic and lumbar spine in children and adolescents].

PubMed

Kraus, R; Stahl, J-P; Heiss, C; Horas, U; Dongowski, N; Schnettler, R

2013-05-01

Only 1.5-2% of all fractures in children and adolescents are fractures of the thoracic and lumbar spine. Treatment is most often conservative. This study compares the own experience with the recent literature. Over a 48 month period all patients with fractures of the thoracic and lumbar spine, younger than 16 years were included prospectively. Of the patients 67 underwent follow-up investigations after 3-36 months. The average age of the patients was 11.9 years. Sports (53%) and traffic (28%) accidents were most frequent. Fractures most often appeared in the mid-thoracic (47%) and thoracolumbar spine (41%). Operative treatment was performed in 9 cases (10.4%). Secondary loss of alignment was not observed neither after conservative nor operative treatment. Neurological deficits (n=2) did not completely improve. Most fractures of the thoracic and lumbar spine heal fast and without any sequelae. Unstable fractures of type B and C (exclusively occurring as a result of traffic accidents) need operative stabilization as in adults.

Microstructure-failure mode correlations in braided composites

NASA Technical Reports Server (NTRS)

Filatovs, G. J.; Sadler, Robert L.; El-Shiekh, Aly

1992-01-01

Explication of the fracture processes of braided composites is needed for modeling their behavior. Described is a systematic exploration of the relationship between microstructure, loading mode, and micro-failure mechanisms in carbon/epoxy braided composites. The study involved compression and fracture toughness tests and optical and scanning electron fractography, including dynamic in-situ testing. Principal failure mechanisms of low sliding, buckling, and unstable crack growth are correlated to microstructural parameters and loading modes; these are used for defining those microstructural conditions which are strength limiting.

Fracture behavior of W based materials. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hack, J.E.

This report describes the results of a program to investigate the fracture properties of tungsten based materials. In particular, the role of crack velocity on crack instability was determined in a W-Fe-Ni-Co ``heavy alloy`` and pure polycrystalline tungsten. A considerable effort was expended on the development of an appropriate crack velocity gage for use on these materials. Having succeeded in that, the gage technology was employed to determine the crack velocity response to the applied level of stress intensity factor at the onset of crack instability in pre-cracked specimens. The results were also correlated to the failure mode observed inmore » two material systems of interest. Major results include: (1) unstable crack velocity measurements on metallic specimens which require high spatial resolution require the use of brittle, insulating substrates, as opposed to the ductile, polymer based substrates employed in low spatial resolution measurements; and (2) brittle failure modes, such as cleavage, are characterized by relatively slow unstable crack velocities while evidence of high degrees of deformation are associated with failures which proceed at high unstable crack velocities. This latter behavior is consistent with the predictions of the modeling of Hack et al and may have a significant impact on the interpretation of fractographs in general.« less

Structure and properties of corrosion and wear resistant Cr-Mn-N steels

NASA Astrophysics Data System (ADS)

Lenel, U. R.; Knott, B. R.

1987-06-01

Steels containing about 12 pct Cr, 10 pct Mn, and 0.2 pct N have been shown to have an unstable austenitic microstructure and have good ductility, extreme work hardening, high fracture strength, excellent toughness, good wear resistance, and moderate corrosion resistance. A series of alloys containing 9.5 to 12.8 pct Cr, 5.0 to 10.4 pct Mn, 0.16 to 0.32 pct N, 0.05 pct C, and residual elements typical of stainless steels was investigated by microstructural examination and mechanical, abrasion, and corrosion testing. Microstructures ranged from martensite to unstable austenite. The unstable austenitic steels transformed to α martensite on deformation and displayed very high work hardening, exceeding that of Hadfield’s manganese steels. Fracture strengths similar to high carbon martensitic stainless steels were obtained while ductility and toughness values were high, similar to austenitic stainless steels. Resistance to abrasive wear exceeded that of commercial abrasion resistant steels and other stainless steels. Corrosion resistance was similar to that of other 12 pct Cr steels. Properties were not much affected by minor compositional variations or rolled-in nitrogen porosity. In 12 pct Cr-10 pct Mn alloys, ingot porosity was avoided when nitrogen levels were below 0.19 pet, and austenitic microstructures were obtained when nitrogen levels exceeded 0.14 pct.

Haemodynamically Unstable Pelvic Fractures

DTIC Science & Technology

2009-01-01

through the pubic symphysis, and posteriorlywith the sacrum forming the sacroiliac (SI) joints (Fig. 1). The SI joints are the strongest in the body...Gardner MJ, Kendoff D, Ostermeier S, et al. Sacroiliac joint compression using an anterior pelvic compressor: a mechanical study in synthetic bone. J

Numerical computation of central crack growth in an active particle of electrodes influenced by multiple factors

NASA Astrophysics Data System (ADS)

Zhang, Yuwei; Guo, Zhansheng

2018-03-01

Mechanical degradation, especially fractures in active particles in an electrode, is a major reason why the capacity of lithium-ion batteries fades. This paper proposes a model that couples Li-ion diffusion, stress evolution, and damage mechanics to simulate the growth of central cracks in cathode particles (LiMn2O4) by an extended finite element method by considering the influence of multiple factors. The simulation shows that particles are likely to crack at a high discharge rate, when the particle radius is large, or when the initial central crack is longer. It also shows that the maximum principal tensile stress decreases and cracking becomes more difficult when the influence of crack surface diffusion is considered. The fracturing process occurs according to the following stages: no crack growth, stable crack growth, and unstable crack growth. Changing the charge/discharge strategy before unstable crack growth sets in is beneficial to prevent further capacity fading during electrochemical cycling.

Open reduction internal fixation of the unstable mallet fracture.

PubMed

Phadnis, Joideep; Yousaf, Sohail; Little, Nicholas; Chidambaram, Ramiah; Mok, Daniel

2010-09-01

Unstable mallet fractures of the digit pose a challenge when treated surgically. We present the results of a technique, not earlier described, for the fixation of these uncommon injuries. The technique involves anatomical reduction and stable fixation of the distal articular fragment combined with stabilization of the distal interphalangeal joint with buried Kirschner wires allowing early mobilization of the digit. Twenty patients with an average follow-up of 12.7 months (10 mo to 21 mo) are presented. Results were good/excellent (Crawford's criteria) in 16 patients, fair in 3, and poor in 1 with those operated upon within 2 weeks postinjury achieving the best results. There were no incidences of fixation failure, loss of reduction, or posttraumatic osteoarthritis. One patient had a minor infection, but there were no cases of nail deformity or wound breakdown. There was high patient satisfaction and all patients returned to work after treatment. We conclude that this is a reliable technique with minimal complications and is comparable with other published operative and nonoperative treatment modalities.

Fingering, Fracturing and Dissolution in Granular Media

NASA Astrophysics Data System (ADS)

Juanes, R.; Cueto-Felgueroso, L.; Trojer, M.; Zhao, B.; Fu, X.

2014-12-01

The displacement of one fluid by another in a porous medium give rise to a rich variety of hydrodynamic instabilities. Beyond their scientific value as fascinating models of pattern formation, unstable porous-media flows are essential to understanding many natural and man-made processes, including water infiltration in the vadose zone, carbon dioxide injection and storage in deep saline aquifers, and hydrocarbon recovery. Here, we review the pattern-selection mechanisms of a wide spectrum of porous-media flows that develop hydrodynamic instabilities, discuss their origin and the mathematical models that have been used to describe them. We point out many challenges that remain to be resolved in the context of multiphase flows, and suggest modeling approaches that may offer new quantitative understanding. In particular, I will present experimental, theoretical and computational results for: (1) fluid spreading under partial wetting; (2) the impact of wettability on viscously unstable multiphase flow in porous media; (3) capillary fracturing in granular media; and (4) rock dissolution during convective mixing in porous media.

Decision Making in the Management of Extracapsular Fractures of the Proximal Femur - is the Dynamic Hip Screw the Prevailing Gold Standard?

PubMed

Jacob, Joshua; Desai, Ankit; Trompeter, Alex

2017-01-01

Currently, approximately half of all hip fractures are extracapsular, with an incidence as high as 50 in 100,000 in some countries. The common classification systems fail to explain the logistics of fracture classification and whether they all behave in the same manner. The Muller AO classification system is a useful platform to delineate stable and unstable fractures. The Dynamic hip screw (DHS) however, has remained the 'gold standard' implant of choice for application in all extracapsular fractures. The DHS relies on the integrity and strength of the lateral femoral wall as well as the postero-medial fragment. An analysis of several studies indicates significant improvements in design and techniques to ensure a better outcome with intramedullary nails. This article reviews the historical trends that helped to evolve the DHS implant as well as discussing if the surgeon should remain content with this implant. We suggest that the gold standard surgical management of extracapsular fractures can, and should, evolve.

Conservative Management of Odontoid Peg Fractures, long term follow up.

PubMed

Osman, Aheed; Alageli, Nabil A; Short, D J; Masri, W S El

2017-01-01

The aim of the study was to look at the long-term effects of conservative management of odontoid peg fractures. We reviewed 48 consecutive patients with type II (32) and 16 type III, odontoid peg fractures. The clinical & radiological outcomes were assessed over an average period of follow up of 8 years. Union rate was determined and we discussed several factors that may affect it. Patients were treated conservatively with an average period of bed rest of 4 weeks followed by bracing for an average of 9 weeks. Bony union was established in 25 of 32 (78%) type II fractures. Of 7 cases of no bony union 4 were stable probably with fibrous union. 3 remained unstable. In 13 of 16(83%) type III fractures bony union was established. 2 of the 3 with no bony union were considered stable. Osseous non-union was higher in patients with displacement of >5 mm, but there is no correlation between union and age, gender or angulation of the fracture in both types.

Functional outcome of open reduction and internal fixation for completely unstable pelvic ring fractures (type C): a report of 40 cases.

PubMed

Kabak, Sevki; Halici, Mehmet; Tuncel, Mehmet; Avsarogullari, Levent; Baktir, Ali; Basturk, Mustafa

2003-09-01

To evaluate functional outcomes, morbidity and mortality rates, and psychological and psychosomatic status in patients treated for completely unstable pelvic injuries (Tile class C). Prospective clinical study. University hospital. Forty patients treated with anterior and posterior internal fixation for unstable pelvic ring fractures between January 1992 and August 1999. Open reduction and anterior and posterior internal fixation of the pelvic ring. The data were analyzed as follows: pelvic fracture classification, Tile classification; severity of trauma, Injury Severity Score (ISS); functional outcomes, the Majeed Outcome Scale; psychological and psychosomatic status, Hamilton Depression and Anxiety Rating Score (HDARS). Preoperatively the average ISS was 29.4 (range 12-66). There was a statistically significant positive correlation between anxiety and ISS (r = 0.536, P < 0.01). Two patients died during the early postoperative period. Two additional patients were lost to follow-up, leaving 36 patients followed for an average of 45 months (range 21-116 months). Deep infections developed in three patients with a posterior pelvic ring injury who had been treated with percutaneous fixation techniques. These were treated successfully with débridement. Nine patients complained of pain of pelvic origin. Nerve deficits recovered completely in four of the seven patients with preoperative neurologic deficiency. Moderate or major depression was diagnosed in sexually dysfunctional patients in the 12th postoperative month according to HDARS (r = -0.559, P < 0.001). At the last visit, there was an inverse correlation between ability to work and depression and anxiety (r = -0.551, r = -0.391). An inverse correlation was found between pain and ability to work (r = 0.597, P < 0.001). Of the 36 patients, 26 returned to their original jobs at the last follow-up visit. Morbidity and mortality rates are higher in patients with a completely unstable pelvic ring injury. Emergency department stabilization and reconstruction of the pelvic ring with optimal operative techniques in these patients can reduce morbidity and mortality rates. Anterior and posterior internal fixation results in satisfactory clinical and radiologic outcomes. The affective status of patients is an important aspect that should be considered during the entire care of the patient.

Periprosthetic Fractures Following Total Knee Arthroplasty

PubMed Central

Kim, Nam Ki

2015-01-01

Periprosthetic fractures after total knee arthroplasty may occur in any part of the femur, tibia and patella, and the most common pattern involves the supracondylar area of the distal femur. Supracondylar periprosthetic fractures frequently occur above a well-fixed prosthesis, and risk factors include anterior femoral cortical notching and use of the rotational constrained implant. Periprosthetic tibial fractures are frequently associated with loose components and malalignment or malposition of implants. Fractures of the patella are much less common and associated with rheumatoid arthritis, use of steroid, osteonecrosis and malalignment of implants. Most patients with periprosthetic fractures around the knee are the elderly with poor bone quality. There are many difficulties and increased risk of nonunion after treatment because reduction and internal fixation is interfered with by preexisting prosthesis and bone cement. Additionally, previous soft tissue injury is another disadvantageous condition for bone healing. Many authors reported good clinical outcomes after non-operative treatment of undisplaced or minimally displaced periprosthetic fractures; however, open reduction or revision arthroplasty was required in displaced fractures or fractures with unstable prosthesis. Periprosthetic fractures around the knee should be prevented by appropriate technique during total knee arthroplasty. Nevertheless, if a periprosthetic fracture occurs, an appropriate treatment method should be selected considering the stability of the prosthesis, displacement of fracture and bone quality. PMID:25750888

Use of the S3 Corridor for Iliosacral Fixation in a Dysmorphic Sacrum: A Case Report.

PubMed

El Dafrawy, Mostafa H; Strike, Sophia A; Osgood, Greg M

2017-01-01

The S1 and S2 corridors are the typical osseous pathways for iliosacral screw fixation of posterior pelvic ring fractures. In dysmorphic sacra, the S1 screw trajectory is often different from that in normal sacra. We present a case of iliosacral screw placement in the third sacral segment for fixation of a complex lateral compression type-3 pelvic fracture in a patient with a dysmorphic sacrum. In patients with dysmorphic sacra and unstable posterior pelvic ring fractures or dislocations, the S3 corridor may be a feasible osseous fixation pathway that can be used in a manner equivalent to the S2 corridor in a normal sacrum.

Time dependent fracture and cohesive zones

NASA Technical Reports Server (NTRS)

Knauss, W. G.

1993-01-01

This presentation is concerned with the fracture response of materials which develop cohesive or bridging zones at crack tips. Of special interest are concerns regarding crack stability as a function of the law which governs the interrelation between the displacement(s) or strain across these zones and the corresponding holding tractions. It is found that for some materials unstable crack growth can occur, even before the crack tip has experienced a critical COD or strain across the crack, while for others a critical COD will guarantee the onset of fracture. Also shown are results for a rate dependent nonlinear material model for the region inside of a craze for exploring time dependent crack propagation of rate sensitive materials.

Dorsal Plating of Unstable Scaphoid Fractures and Nonunions.

PubMed

Bain, Gregory I; Turow, Arthur; Phadnis, Joideep

2015-09-01

Achieving stable fixation of displaced acute and chronic nonunited scaphoid fractures continues to be a challenge for the treating surgeon. The threaded compression screw has been the mainstay of treatment of these fractures for the last 3 decades; however, persistent nonunion after screw fixation has prompted development of new techniques. Recent results of volar buttress plating have been promising. We describe a novel technique of dorsal scaphoid plating. In contrast to volar plating, the dorsal plate is biomechanically more favorable as it utilizes the tension side of the scaphoid bone for dynamic compression. Dorsal scaphoid plating provides a more stable construct than the traditional Herbert screw and mitigates the need for vascular or corticocancellous bone grafting in most cases.

Comparing slow and fast rupture in laboratory experiments

NASA Astrophysics Data System (ADS)

Aben, F. M.; Brantut, N.; David, E.; Mitchell, T. M.

2017-12-01

During the brittle failure of rock, elastically stored energy is converted into a localized fracture plane and surrounding fracture damage, seismic radiation, and thermal energy. However, the partitioning of energy might vary with the rate of elastic energy release during failure. Here, we present the results of controlled (slow) and dynamic (fast) rupture experiments on dry Lanhélin granite and Westerly granite samples, performed under triaxial stress conditions at confining pressures of 50 and 100 MPa. During the tests, we measured sample shortening, axial load and local strains (with 2 pairs of strain gauges glued directly onto the sample). In addition, acoustic emissions (AEs) and changes in seismic velocities were monitored. The AE rate was used as an indicator to manually control the axial load on the sample to stabilize rupture in the quasi-static failure experiments. For the dynamic rupture experiments a constant strain rate of 10-5 s-1 was applied until sample failure. A third experiment, labeled semi-controlled rupture, involved controlled rupture up to a point where the rupture became unstable and the remaining elastic energy was released dynamically. All experiments were concluded after a macroscopic fracture had developed across the whole sample and frictional sliding commenced. Post-mortem samples were epoxied, cut and polished to reveal the macroscopic fracture and the surrounding damage zone. The samples failed with average rupture velocities varying from 5x10-6 m/s up to >> 0.1 m/s. The analyses of AE locations on the slow ruptures reveal that within Westerly granite samples - with a smaller grain size - fracture planes are disbanded in favor of other planes when a geometrical irregularity is encountered. For the coarser grained Lanhélin granite a single fracture plane is always formed, although irregularities are recognized as well. The semi-controlled experiments show that for both rock types the rupture can become unstable in response to these irregularities. In Westerly granite, slow rupture experiments tend to produce complex fracture patterns while during the dynamic rupture experiments secondary rupture planes are not formed. These findings show that grain or flaw size, flaw distribution, and rupture speed strongly influence fracture localization and propagation.

History of internal fixation with plates (part 2): new developments after World War II; compressing plates and locked plates.

PubMed

Hernigou, Philippe; Pariat, Jacques

2017-07-01

The first techniques of operative fracture with plates were developed in the 19th century. In fact, at the beginning these methods consisted of an open reduction of the fracture usually followed by a very unstable fixation. As a consequence, the fracture had to be opened with a real risk of (sometimes lethal) infection, and due to unstable fixation, protection with a cast was often necessary. During the period between World Wars I and II, plates for fracture fixation developed with great variety. It became increasingly recognised that, because a fracture of a long bone normally heals with minimal resorption at the bone ends, this may result in slight shortening and collapse, so a very rigid plate might prevent such collapse. However, as a consequence, delayed healing was observed unless the patient was lucky enough to have the plate break. One way of dealing with this was to use a slotted plate in which the screws could move axially, but the really important advance was recognition of the role of compression. After the first description of compression by Danis with a "coapteur", Bagby and Müller with the AO improved the technique of compression. The classic dynamic compression plates from the 1970s were the key to a very rigid fixation, leading to primary bone healing. Nevertheless, the use of strong plates resulted in delayed union and the osteoporosis, cancellous bone, comminution, and/or pathological bone resulted in some failures due to insufficient stability. Finally, new devices represented by locking plates increased the stability, contributing to the principles of a more biological osteosynthesis while giving enough stability to allow immediate full weight bearing in some patients.

Complex pelvic ring injuries associated with floating knee in a poly-trauma patient: A case report.

PubMed

Zhou, Yuebin; Guo, Honggang; Cai, Zhiwei; Zhang, Yuan

2017-12-01

Complex pelvic ring fracture associated with floating knee is comparatively rare which usually results from high-energy trauma including vehicle-related accidence, falls from height, and earthquake-related injury. To our knowledge, few literatures have documented such injuries in the individual patient. Management of both injuries present challenges for surgical management and postoperative care. The purpose of this study is to prove the feasibility and benefits of damage control orthopedics (DCO). Our case involved a 45-year-old lady who was hit by a dilapidated building. The patient was anxious, pale and hemodynamically stable at the initial examination. The pelvis was unstable and there were obvious deformities in the left lower extremities. Significant degloved injuries in the left leg were noted. Her radiographs and physical examination verified the above signs. Unstable pelvic fractures, multiple fractures of bilateral lower limbs with floating knee injury, multiple pelvic and rib fractures and multiple degloving injuries and soft tissue contusion formed the characteristics of the multiple-injury. The algorithm of DCO was determined as the treatment. Early simplified procedures such as wound debridement, pelvis fixation, closed reduction and EF of the right shoulder joint, and chest wall fixation were conducted as soon as possible. After a period of time, internal fixations were applied to the fracture sites. The subsequent functional exercise was also conducted in accordance with this algorithm. This patient got recovery after the treatments which were guided by the criterion of DCO. The restoration of limb functional and the quality of life greatly improved. The DCO plays a decisive role in the first aid and follow-up treatment of this patient. The guidelines of management of complex pelvic ring injuries and floating knee should be established by authorities.

[Flat rate reimbursement system for minimally invasive management of unstable vertebral fractures. An analysis of costs and benefits].

PubMed

Hartwig, E; Schultheiss, M; Bischoff, M

2002-08-01

Some 30% of unstable vertebral fractures of the thoracic and lumbar spine involve a destruction of the ventral column and thus of the supporting structures of the spine. This requires extensive surgical reconstruction procedures, which are carried out using minimally invasive techniques. The disadvantages of the minimally invasive methods are the high cost, the technical equipment and the expenditure of time required in the initial phase for the performance of the surgical procedure. With the structural reform of the health care system in the year 2000, the private-sector regulatory bodies were called upon to introduce a flat-rate compensation system for hospital services according to section 17b of the Hospital Law (KHG). The previous financing system which involved per-diem operating cost rates has thus been abolished. Calculations of individual entities are now required. Considering the case values to date, a contribution margin deficit of EUR 4628.45 has been calculated for our patients with fractures of the thoracic and lumbar spine without neurological defunctionalization symptoms. An economically efficient medical care is thus no longer possible. Consequently, an adjustment of the German relative weights must urgently be demanded in order to guarantee a high-quality medical care of patients.

Value Added: the Case for Point-of-View Camera use in Orthopedic Surgical Education.

PubMed

Karam, Matthew D; Thomas, Geb W; Taylor, Leah; Liu, Xiaoxing; Anthony, Chris A; Anderson, Donald D

2016-01-01

Orthopedic surgical education is evolving as educators search for new ways to enhance surgical skills training. Orthopedic educators should seek new methods and technologies to augment and add value to real-time orthopedic surgical experience. This paper describes a protocol whereby we have started to capture and evaluate specific orthopedic milestone procedures with a GoPro® point-of-view video camera and a dedicated video reviewing website as a way of supplementing the current paradigm in surgical skills training. We report our experience regarding the details and feasibility of this protocol. Upon identification of a patient undergoing surgical fixation of a hip or ankle fracture, an orthopedic resident places a GoPro® point-of-view camera on his or her forehead. All fluoroscopic images acquired during the case are saved and later incorporated into a video on the reviewing website. Surgical videos are uploaded to a secure server and are accessible for later review and assessment via a custom-built website. An electronic survey of resident participants was performed utilizing Qualtrics software. Results are reported using descriptive statistics. A total of 51 surgical videos involving 23 different residents have been captured to date. This includes 20 intertrochanteric hip fracture cases and 31 ankle fracture cases. The average duration of each surgical video was 1 hour and 16 minutes (range 40 minutes to 2 hours and 19 minutes). Of 24 orthopedic resident surgeons surveyed, 88% thought capturing a video portfolio of orthopedic milestones would benefit their education. There is a growing demand in orthopedic surgical education to extract more value from each surgical experience. While further work in development and refinement of such assessments is necessary, we feel that intraoperative video, particularly when captured and presented in a non-threatening, user friendly manner, can add significant value to the present and future paradigm of orthopedic surgical skill training.

Value Added: the Case for Point-of-View Camera use in Orthopedic Surgical Education

PubMed Central

Thomas, Geb W.; Taylor, Leah; Liu, Xiaoxing; Anthony, Chris A.; Anderson, Donald D.

2016-01-01

Abstract Background Orthopedic surgical education is evolving as educators search for new ways to enhance surgical skills training. Orthopedic educators should seek new methods and technologies to augment and add value to real-time orthopedic surgical experience. This paper describes a protocol whereby we have started to capture and evaluate specific orthopedic milestone procedures with a GoPro® point-of-view video camera and a dedicated video reviewing website as a way of supplementing the current paradigm in surgical skills training. We report our experience regarding the details and feasibility of this protocol. Methods Upon identification of a patient undergoing surgical fixation of a hip or ankle fracture, an orthopedic resident places a GoPro® point-of-view camera on his or her forehead. All fluoroscopic images acquired during the case are saved and later incorporated into a video on the reviewing website. Surgical videos are uploaded to a secure server and are accessible for later review and assessment via a custom-built website. An electronic survey of resident participants was performed utilizing Qualtrics software. Results are reported using descriptive statistics. Results A total of 51 surgical videos involving 23 different residents have been captured to date. This includes 20 intertrochanteric hip fracture cases and 31 ankle fracture cases. The average duration of each surgical video was 1 hour and 16 minutes (range 40 minutes to 2 hours and 19 minutes). Of 24 orthopedic resident surgeons surveyed, 88% thought capturing a video portfolio of orthopedic milestones would benefit their education Conclusions There is a growing demand in orthopedic surgical education to extract more value from each surgical experience. While further work in development and refinement of such assessments is necessary, we feel that intraoperative video, particularly when captured and presented in a non-threatening, user friendly manner, can add significant value to the present and future paradigm of orthopedic surgical skill training. PMID:27528828

Comparison of Intralaminar and Interlaminar Mode-I Fracture Toughness of Unidirectional IM7/8552 Graphite/Epoxy Composite

NASA Technical Reports Server (NTRS)

Czabaj, Michael W.; Ratcliffe, James

2012-01-01

The intralaminar and interlaminar mode-I fracture-toughness of a unidirectional IM7/8552 graphite/epoxy composite were measured using compact tension (CT) and double cantilever beam (DCB) test specimens, respectively. Two starter crack geometries were considered for both the CT and DCB specimen configurations. In the first case, starter cracks were produced by 12.5 micron thick, Teflon film inserts. In the second case, considerably sharper starter cracks were produced by fatigue precracking. For each specimen configuration, use of the Teflon film starter cracks resulted in initially unstable crack growth and artificially high initiation fracture-toughness values. Conversely, specimens with fatigue precracks exhibited stable growth onset and lower initiation fracture toughness. For CT and DCB specimens with fatigue precracks, the intralaminar and interlaminar initiation fracture toughnesses were approximately equal. However, during propagation, the CT specimens exhibited more extensive fiber bridging, and rapidly increasing R-curve behavior as compared to the DCB specimens. Observations of initiation and propagation of intralaminar and interlaminar fracture, and the measurements of fracture toughness, were supported by fractographic analysis using scanning electron microscopy.

Epidemiology of Pelvic Ring Fractures in a Level 1 Trauma Center in the Netherlands

PubMed Central

Biert, Jan; Edwards, Michael John Richard

2017-01-01

Purpose This study was conducted to study the epidemiology, classification, treatment and outcome of a large patient group with pelvic ring injury in a level 1 trauma center in the Netherlands. Materials and Methods In the period of 2004 to 2014, we encountered 537 patients with a pelvic fracture. Many of them are due to a high energy trauma and therefore many concomitant injuries are observed. Tile A fractures were seen in 137 patients (25.5%), Tile B fractures in 211 (39.3%) and Tile C fractures in 189 patients (35.2%). Results Patients with unstable fracture types (Tile B1 and B3, Tile C) had significantly higher injury severity score, transfusion rates, need for laparotomy and definitive operative stabilization and complication rate. However, mortality did not differ significantly among Tile A, B or C fractures. Conclusion Overall outcome was good with a mortality rate of 13.6%, which is comparable with other rAelpmorotsst. half of the patients treated could directly be dismissed to their own homes. PMID:29250500

Biomechanical comparison of double-row locking plates versus single- and double-row non-locking plates in a comminuted metacarpal fracture model.

PubMed

Gajendran, Varun K; Szabo, Robert M; Myo, George K; Curtiss, Shane B

2009-12-01

Open or unstable metacarpal fractures frequently require open reduction and internal fixation. Locking plate technology has improved fixation of unstable fractures in certain settings. In this study, we hypothesized that there would be a difference in strength of fixation using double-row locking plates compared with single- and double-row non-locking plates in comminuted metacarpal fractures. We tested our hypothesis in a gap metacarpal fracture model simulating comminution using fourth-generation, biomechanical testing-grade composite sawbones. The metacarpals were divided into 6 groups of 15 bones each. Groups 1 and 4 were plated with a standard 6-hole, 2.3-mm plate in AO fashion. Groups 2 and 5 were plated with a 6-hole double-row 3-dimensional non-locking plate with bicortical screws aimed for convergence. Groups 3 and 6 were plated with a 6-hole double-row 3-dimensional locking plate with unicortical screws. The plated metacarpals were then tested to failure against cantilever apex dorsal bending (groups 1-3) and torsion (groups 4-6). The loads to failure in groups 1 to 3 were 198 +/- 18, 223 +/- 29, and 203 +/- 19 N, respectively. The torques to failure in groups 4 to 6 were 2,033 +/- 155, 3,190 +/- 235, and 3,161 +/- 268 N mm, respectively. Group 2 had the highest load to failure, whereas groups 5 and 6 shared the highest torques to failure (p < .05). Locking and non-locking double-row plates had equivalent bending and torsional stiffness, significantly higher than observed for the single-row non-locking plate. No other statistical differences were noted between groups. When subjected to the physiologically relevant forces of apex dorsal bending and torsion in a comminuted metacarpal fracture model, double-row 3-dimensional non-locking plates provided superior stability in bending and equivalent stability in torsion compared with double-row 3-dimensional locking plates, whereas single-row non-locking plates provided the least stability.

Treatment of reducible unstable fractures of the distal radius: randomized clinical study comparing the locked volar plate and external fixator methods: study protocol.

PubMed

Raduan Neto, Jorge; de Moraes, Vinicius Ynoe; Gomes Dos Santos, João B; Faloppa, Flávio; Belloti, João Carlos

2014-03-05

Various treatments are available for reducible unstable fractures of the distal radius, such as closed reduction combined with fixation by external fixator (EF), and rigid internal fixation using a locked volar plate (VP). Although there are studies comparing these methods, there is no conclusive evidence indicating which treatment is best. The hypothesis of this study is that surgical treatment with a VP is more effective than EF from the standpoint of functional outcome (patient-reported). The study is randomized clinical trial with parallel groups and a blinded evaluator and involves the surgical interventions EF and VP. Patients will be randomly assigned (assignment ratio 1:1) using sealed opaque envelopes. This trial will include consecutive adult patients with an acute (up to 15 days) displaced, unstable fracture of the distal end of the radius of type A2, A3, C1, C2 or C3 by the Arbeitsgemeinschaft für Osteosynthesefragen-Association for the Study of Internal Fixation classification and type II or type III by the IDEAL32 classification, without previous surgical treatments of the wrist. The surgical intervention assigned will be performed by three surgical specialists familiar with the techniques described. Evaluations will be performed at 2, and 8 weeks, 3, 6 and 12 months, with the primary outcomes being measured by the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and measurement of pain (Visual Analog Pain Scale and digital algometer). Secondary outcomes will include radiographic parameters, objective functional evaluation (goniometry and dynamometry), and the rate of complications and method failure according to the intention-to-treat principle. Final postoperative evaluations (6 and 12 months) will be performed by independent blinded evaluators. For the Student's t-test, a difference of 10 points in the DASH score, with a 95% confidence interval, a statistical power of 80%, and 20% sampling error results in 36 patients per group. Results from this study protocol will improve the current evidence regarding to the surgical treatment these fractures. ISCRTN09599740.

Cervical spine injuries in civilian victims of explosions: Should cervical collars be used?

PubMed

Klein, Yoram; Arieli, Izhar; Sagiv, Shaul; Peleg, Kobi; Ben-Galim, Peleg

2016-06-01

Semirigid cervical collars (SRCCs) are routinely applied to victims of explosions as part of the prehospital trauma protocols. Previous studies have shown that the use of SRCC in penetrating injuries is not justified because of the scarcity of unstable cervical spine injuries and the risk of obscuring other neck injuries. Explosion can inflict injuries by fragments penetration, blast injury, blunt force, and burns. The purpose of the study was to determine the occurrence of cervical spine instability without irreversible neurologic deficit and other potentially life-threatening nonskeletal neck injuries among victims of explosions. The potential benefits and risks of SRCC application in explosion-related injuries were evaluated. This is a retrospective cohort study of all explosion civilian victims admitted to Israeli hospitals during the years 1998 to 2010. Data collection was based on the Israeli national trauma registry and the hospital records and included demographic, clinical, and radiologic details of all patients with documented cervical spine injuries. The cohort included 2,267 patients. All of them were secondary to terrorist attacks. SRCC was applied to all the patients at the scene. Nineteen patients (0.83%) had cervical spine fractures. Nine patients (0.088%) had unstable cervical spine injury. All but one had irreversible neurologic deficit on admission. A total of 151 patients (6.6%) had potentially life-threatening penetrating nonskeletal neck injuries. Unstable cervical spine injuries secondary to explosion are extremely rare. The majority of unstable cervical spine fractures were secondary to penetrating injuries, with irreversible neurologic deficits on admission. The application of SRCC did not seem to be of any benefit in these patients and might pose a risk of obscuring other neck injuries. We recommend that SRCC will not be used in the prehospital management of victims of explosions. Prognostic/epidemiologic study, level III.

Cadaveric study of movement in the unstable upper cervical spine during emergency management: tracheal intubation and cervical spine immobilisation—a study protocol for a prospective randomised crossover trial

PubMed Central

Popp, Erik; Hüttlin, Petra; Weilbacher, Frank; Münzberg, Matthias; Schneider, Niko; Kreinest, Michael

2017-01-01

Introduction Emergency management of upper cervical spine injuries often requires cervical spine immobilisation and some critical patients also require airway management. The movement of cervical spine created by tracheal intubation and cervical spine immobilisation can potentially exacerbate cervical spinal cord injury. However, the evidence that previous studies have provided remains unclear, due to lack of a direct measurement technique for dural sac's space during dynamic processes. Our study will use myelography method and a wireless human motion tracker to characterise and compare the change of dural sac's space during tracheal intubations and cervical spine immobilisation in the presence of unstable upper cervical spine injury such as atlanto-occipital dislocation or type II odontoid fracture. Methods and analysis Perform laryngoscopy and intubation, video laryngoscope intubation, laryngeal tube insertion, fiberoptic intubation and cervical collar application on cadaveric models of unstable upper cervical spine injury such as atlanto-occipital dislocation or type II odontoid fracture. The change of dural sac's space and the motion of unstable cervical segment are recorded by video fluoroscopy with previously performing myelography, which enables us to directly measure dural sac's space. Simultaneously, the whole cervical spine motion is recorded at a wireless human motion tracker. The maximum dural sac compression and the maximum angulation and distraction of the injured segment are measured by reviewing fluoroscopic and myelography images. Ethics and dissemination This study protocol has been approved by the Ethics Committee of the State Medical Association Rhineland-Palatinate, Mainz, Germany. The results will be published in relevant emergency journals and presented at relevant conferences. Trial registration number DRKS00010499. PMID:28864483

Governance in English VET: On the Functioning of a Fractured "System"

ERIC Educational Resources Information Center

Keep, Ewart

2015-01-01

This article explores the governance structures that cover vocational education and training (VET) in England. The English VET system is highly fragmented, complex and unstable, and has tended to oscillate between centralised command and control, and attempts at marketisation. Its governance arrangements reflect this situation. The various…

Pelvic fracture and associated urologic injuries.

PubMed

Brandes, S; Borrelli, J

2001-12-01

Successful management of patients with major pelvic injuries requires a team approach including orthopedic, urologic, and trauma surgeons. Each unstable pelvic disruption must be treated aggressively to minimize complications and maximize long-term functional outcome. Commonly associated urologic injuries include injuries of the urethra, corpora cavernosa (penis), bladder, and bladder neck. Bladder injuries are usually extraperitoneal and result from shearing forces or direct laceration by a bone spicule. Posterior urethral injuries occur more commonly with vertically applied forces, which typically create Malgaigne-type fractures. Common complications of urethral disruption are urethral stricture, incontinence, and impotence. Acute urethral injury management is controversial, although it appears that early primary realignment has promise for minimizing the complications. Impotence after pelvic fracture is predominantly vascular in origin, not neurologic as once thought.

Direct reduction may need to be considered to avoid postoperative subtype P in patients with an unstable trochanteric fracture: a retrospective study using a multivariate analysis.

PubMed

Kozono, Naoya; Ikemura, Satoshi; Yamashita, Akihisa; Harada, Takashi; Watanabe, Tetsuya; Shirasawa, Kenzo

2014-12-01

It has recently been reported that the cases with an anterior femoral neck cortex posterior to the distal fragment (subtype P) in the lateral view of a postoperative radiograph have a risk of excessive sliding of lag screws compared to those located anterior to the distal fragment (subtype A) or perfectly continuous to the distal fragment (subtype N) following osteosynthesis for the treatment of a trochanteric fracture. The purpose of this study was to investigate factors that influence the postoperative subtype in the lateral view of radiographs. This study reviewed 136 patients who underwent osteosynthesis using an intramedullary hip nail for the treatment of a trochanteric fracture. A closed reduction was performed in 130 patients (95.6 %), while a direct reduction via a small elevator with a small skin incision was performed in the other six patients (4.4 %). The 136 patients were divided into two groups (subtype P and subtype A or N) based on postoperative radiographs taken of the lateral view. Both clinical and radiological factors were analyzed using the univariate and multivariable analyses. Thirty-nine patients (29 %) were categorized as subtype P and 97 patients (71 %) were categorized as subtype A or N. A multivariate analysis demonstrated that unstable fractures were associated with a significant risk of postoperative subtype P (Odds ratio: 24.45, P = 0.0024). The results of this study suggest that direct reduction via a small elevator with a small skin incision or percutaneous intrafocal pinning may be needed in these cases.

[Osteosynthesis and cup revision in periprosthetic acetabulum fractures using a Kocher-Langenbeck approach].

PubMed

Schwabe, P; Märdian, S; Perka, C; Schaser, K-D

2016-04-01

Reconstruction/stable fixation of the acetabular columns to create an adequate periacetabular requirement for the implantation of a revision cup. Displaced/nondisplaced fractures with involvement of the posterior column. Resulting instability of the cup in an adequate bone stock situation. Periprosthetic acetabulum fractures with inadequate bone stock. Extended periacetabular defects with loss of anchorage options. Isolated periprosthetic fractures of the anterior column. Septic loosening. Dorsal approach. Dislocation of hip. Mechanical testing of inlaying acetabular cup. With unstable cup situation explantation of the cup, fracture fixation of acetabulum with dorsal double plate osteosynthesis along the posterior column. Cup revision. Hip joint reposition. Early mobilization; partial weight bearing for 12 weeks. Thrombosis prophylaxis. Clinical and radiological follow-ups. Periprosthetic acetabular fracture in 17 patients with 9 fractures after primary total hip replacement (THR), 8 after revision THR. Fractures: 12 due to trauma, 5 spontaneously; 7 anterior column fractures, 5 transverse fractures, 4 posterior column fractures, 1 two column fracture after hemiendoprosthesis. 5 type 1 fractures and 12 type 2 fractures. Operatively treated cases (10/17) received 3 reinforcement ring, 2 pedestal cup, 1 standard revision cup, cup-1 cage construct, 1 ventral plate osteosynthesis, 1 dorsal plate osteosynthesis, and 1 dorsal plate osteosynthesis plus cup revision (10-month Harris Hip Score 78 points). Radiological follow-up for 10 patients: consolidation of fractures without dislocation and a fixed acetabular cup. No revision surgeries during follow-up; 2 hip dislocations, 1 transient sciatic nerve palsy.

Probabilistic Assessment of Fracture Progression in Composite Structures

NASA Technical Reports Server (NTRS)

Chamis, Christos C.; Minnetyan, Levon; Mauget, Bertrand; Huang, Dade; Addi, Frank

1999-01-01

This report describes methods and corresponding computer codes that are used to evaluate progressive damage and fracture and to perform probabilistic assessment in built-up composite structures. Structural response is assessed probabilistically, during progressive fracture. The effects of design variable uncertainties on structural fracture progression are quantified. The fast probability integrator (FPI) is used to assess the response scatter in the composite structure at damage initiation. The sensitivity of the damage response to design variables is computed. The methods are general purpose and are applicable to stitched and unstitched composites in all types of structures and fracture processes starting from damage initiation to unstable propagation and to global structure collapse. The methods are demonstrated for a polymer matrix composite stiffened panel subjected to pressure. The results indicated that composite constituent properties, fabrication parameters, and respective uncertainties have a significant effect on structural durability and reliability. Design implications with regard to damage progression, damage tolerance, and reliability of composite structures are examined.

Association of Ipsilateral Rib Fractures With Displacement of Midshaft Clavicle Fractures.

PubMed

Stahl, Daniel; Ellington, Matthew; Brennan, Kindyle; Brennan, Michael

2017-04-01

To determine whether the presence of ipsilateral rib fractures affects the rate of a clavicle fracture being unstable (>100% displacement). A retrospective review from 2002-2013 performed at a single level 1 trauma center evaluated 243 midshaft clavicle fractures. Single Level 1 trauma center. These fractures were subdivided into those with ipsilateral rib fractures (CIR; n = 149) and those without ipsilateral rib fractures (CnIR; n = 94). The amount of displacement was measured on the initial injury radiograph and subsequent follow-up radiographs. Fractures were classified into either <100% displacement or >100% displacement, based on anteroposterior radiographs. Ipsilateral rib fractures were recorded based on which number rib was fractured and the total number of fractured ribs. One hundred sixteen (78%) of the CIR group and 51 (54%) of the CnIR group were found to have >100% displacement at follow-up (P = 0.0047). Seventy-two percent of the CIR group demonstrated progression from <100% to >100% displacement of the fracture compared with only 54% of the CnIR group (P < 0.05). The odds ratio for progression of the clavicle fracture to >100% was 4.08 (P = 0.000194) when ribs 1-4 were fractured and not significant for rib fractures 5-8 or 9-12. The presence of concomitant ipsilateral rib fractures significantly increases the rate of midshaft clavicle fractures being >100% displaced. In addition, a fracture involving the upper one-third of the ribs significantly increases the rate of the clavicle fracture being >100% displaced on early follow-up. Clavicle fractures with associated ipsilateral rib fractures tend to demonstrate an increased amount of displacement on follow-up radiographs compared with those without ipsilateral rib fractures. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Pelvic packing or angiography: competitive or complementary?

PubMed

Suzuki, Takashi; Smith, Wade R; Moore, Ernest E

2009-04-01

Pelvic angiography is an established technique that has evolved into a highly effective means of controlling arterial pelvic haemorrhage. The current dominant paradigm for haemodynamically unstable patients with pelvic fractures is angiographic management combined with mechanical stabilisation of the pelvis. However, an effective rapid screening tool for arterial bleeding in pelvic fracture patients has yet to be identified. There is also no precise way to determine the major source of bleeding responsible for haemodynamic instability. In many pelvic fracture patients, bleeding is from venous lacerations which are not effectively treated with angiography to fractured bony surfaces. Modern pelvic packing consists of time-saving and minimally invasive techniques which appear to result in effective control of the haemorrhage via tamponade. This review article focuses on the recent body of knowledge on angiography and pelvic packing. We propose the optimal role for each modality in trauma centres.

A conservative approach to pediatric mandibular fracture management: outcome and advantages.

PubMed

Khatri, Amit; Kalra, Namita

2011-01-01

Pediatric mandibular fractures are rare and their treatment remains controversial. Management is extremely complicated in mixed dentition as it is inherently dynamic and unstable. Treatment options include soft diet, intermaxillary fixation with eyelet wires, arch bars, circummandibular wiring, or stents. Alternative options include open reduction and internal fixation through either an intraoral or extraoral approach. This case report describes and evaluates the conservative technique of acrylic splint in the treatment of pediatric mandible fracture in a 12-year-old female child. The patient with isolated mandibular fracture was treated with acrylic splint and interdental wiring followed by evaluation of clinical and radiographic healing as well as the somatosensory status. Patient demonstrated clinical union to her pre-injury occlusion by three to four weeks. Panoramic finding supported the finding of clinical examination throughout the study. High osteogenic potential of the pediatric mandible allowed conservative management to be successful in this case.

The importance of pelvic ring stabilization as a life-saving measure in pre-hospital - A case report commented by autopsy.

PubMed

Durão, Carlos; Alves, Magda; Barros, André; Pedrosa, Frederico

2017-08-01

Hip fractures with unstable pelvic ring have great morbidity and mortality rates. These fractures result from high energy trauma such as falls from heights, road accidents and collapsing structures or other similar mechanisms of action. We report the case of a 63 years old man, construction worker, who stood inside a ditch during a wall construction when he was surprised by this collapse, which resulted in direct trauma to the right thigh and pelvis. The autopsy revealed diaphysis fracture of the right femur with an open book pelvic fracture with severe hemorrhagic infiltration and hematoma of the pelvic muscles without arterial injury. Bone bleeding and the vascular damage associated with disruption of the sacroiliac ligaments promote a very significant bleeding. Simple maneuvers such as sheet circumferential compression to promote pelvic ring closure are effective on stabilizing and closure of the sacroiliac joint. Hip manipulation of the fracture was performed during the necropsy to demonstrate and prove how a simple sheet contention can promote stabilization of the pelvic ring by closing the sacroiliac joints in open book fractures.

Decision Making in the Management of Extracapsular Fractures of the Proximal Femur – is the Dynamic Hip Screw the Prevailing Gold Standard?

PubMed Central

Jacob, Joshua; Desai, Ankit; Trompeter, Alex

2017-01-01

Currently, approximately half of all hip fractures are extracapsular, with an incidence as high as 50 in 100,000 in some countries. The common classification systems fail to explain the logistics of fracture classification and whether they all behave in the same manner. The Muller AO classification system is a useful platform to delineate stable and unstable fractures. The Dynamic hip screw (DHS) however, has remained the ‘gold standard’ implant of choice for application in all extracapsular fractures. The DHS relies on the integrity and strength of the lateral femoral wall as well as the postero-medial fragment. An analysis of several studies indicates significant improvements in design and techniques to ensure a better outcome with intramedullary nails. This article reviews the historical trends that helped to evolve the DHS implant as well as discussing if the surgeon should remain content with this implant. We suggest that the gold standard surgical management of extracapsular fractures can, and should, evolve. PMID:29290858

Frictional stability-permeability relationships for fractures in shales

NASA Astrophysics Data System (ADS)

Fang, Yi; Elsworth, Derek; Wang, Chaoyi; Ishibashi, Takuya; Fitts, Jeffrey P.

2017-03-01

There is wide concern that fluid injection in the subsurface, such as for the stimulation of shale reservoirs or for geological CO2 sequestration (GCS), has the potential to induce seismicity that may change reservoir permeability due to fault slip. However, the impact of induced seismicity on fracture permeability evolution remains unclear due to the spectrum of modes of fault reactivation (e.g., stable versus unstable). As seismicity is controlled by the frictional response of fractures, we explore friction-stability-permeability relationships through the concurrent measurement of frictional and hydraulic properties of artificial fractures in Green River shale (GRS) and Opalinus shale (OPS). We observe that carbonate-rich GRS shows higher frictional strength but weak neutral frictional stability. The GRS fracture permeability declines during shearing while an increased sliding velocity reduces the rate of permeability decline. By comparison, the phyllosilicate-rich OPS has lower friction and strong stability while the fracture permeability is reduced due to the swelling behavior that dominates over the shearing induced permeability reduction. Hence, we conclude that the friction-stability-permeability relationship of a fracture is largely controlled by mineral composition and that shale mineral compositions with strong frictional stability may be particularly subject to permanent permeability reduction during fluid infiltration.

Closed bone graft epiphysiodesis for avascular necrosis of the capital femoral epiphysis.

PubMed

Thompson, George H; Lea, Ethan S; Chin, Kenneth; Liu, Raymond W; Son-Hing, Jochen P; Gilmore, Allison

2013-07-01

Avascular necrosis (AVN) of the capital femoral epiphysis (CFE) after an unstable slipped capital femoral epiphysis (SCFE), femoral neck fracture or traumatic hip dislocation can result in severe morbidity. Treatment options for immature patients with AVN are limited, including a closed bone graft epiphysiodesis (CBGE). However, it is unclear whether this procedure prevents AVN progression. We investigated whether early MRI screening and CBGE prevented the development of advanced AVN changes in the CFE and the rates of complications with this approach. We prospectively followed all 13 patients (seven boys, six girls) with unstable SCFEs (six patients), femoral neck fractures (five patients), and traumatic hip dislocations (two patients) and evidence of early AVN treated between 1984 and 2012. Mean age at initial injury was 12 years (range, 10-16 years). Nine of the 13 patients had followup of at least 2 years or until conversion to THA (mean, 4.5 years; range, 0.8-8.5 years), including two with unstable SCFEs, the five with femoral neck fractures, and the two with traumatic hip dislocations. All patients had technetium scans and/or MRI within 1 to 2 months of their initial injury (before CBGE) and all had evidence of early (Ficat 0) AVN. Patients were followed clinically and radiographically for AVN progression. Six of the nine hips did not develop typical clinical or radiographic evidence of AVN. These six patients have been followed 6.3 years (range, 4.3-9.1 years) from initial injury and 5.9 years (range, 3.8-8.5 years) from CBGE. The remaining three patients were diagnosed with AVN at periods ranging from 3 to 6 months after CBGE. Early recognition and treatment of AVN with a CBGE may alter the natural history of this complication. Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Cement augmentation of the Proximal Femoral Nail Antirotation (PFNA) - A multicentre randomized controlled trial.

PubMed

Kammerlander, Christian; Hem, Einar S; Klopfer, Tim; Gebhard, Florian; Sermon, An; Dietrich, Michael; Bach, Olaf; Weil, Yoram; Babst, Reto; Blauth, Michael

2018-04-22

New implant designs like the Proximal Femoral Nail Antirotation (PFNA) were developed to reduce failure rates in unstable pertrochanteric fractures in the elderly. Standardized implant augmentation with up to 6 mL of polymethylmethacrylate (PMMA) cement has been introduced to enhance implant anchorage by increasing the implant-bone interface in osteoporotic bone conditions. Biomechanically, loads to failure were significantly higher with augmentation. The primary objective of this study was to compare the mobility of patients with closed unstable trochanteric fractures treated by PFNA either with or without cement augmentation. A prospective multicentre, randomized, patient-blinded trial was conducted with ambulatory patients aged 75 or older who sustained a closed, unstable trochanteric fracture. Surgical fixation had to be performed within 72 h after admission. Outcomes were evaluated at baseline, during surgery, 3 to 14 days after surgery, 3 months, 6 months, and 12 months after surgery. To evaluate the primary objective, patients' walking speed was assessed by the Timed Up and Go (TUG) test. Secondary objectives included the analysis of implant migration assessed on radiographs, quality of life measured by the Barthel Index, mobility measured by the Parker Mobility Score, and complications. Of 253 randomized patients, 223 patients were eligible: 105 patients were allocated to the PFNA Augmentation group and 118 to PFNA group. At 3 to 14 days after surgery, there was no statistical significant difference in mean walking speed between the treatment groups. For the secondary objectives, also no statistical significant differences were found. However, no patient in the PFNA Augmentation group had a reoperation due to mechanical failure or symptomatic implant migration compared to 6 patients in the PFNA group. Augmentation of the PFNA blade did not improve patients' walking ability compared to the use of a non-augmented PFNA but might have the potential to prevent reoperations by strengthening the osteosynthesis construct. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Angle of torsion of the femur and its correlates.

PubMed

Prasad, R; Vettivel, S; Isaac, B; Jeyaseelan, L; Chandi, G

1996-01-01

Unpaired femora (171), devoid of gross pathology and grouped by gender (94 male and 77 female) and side (88 left and 83 right), were used to measure the angle of femoral torsion and the maximum femur length and to score the degree of prominency of the superior cervical tubercle, intertrochanteric line, quadrate tubercle, linea aspera, and adductor tubercle. The angle of torsion ranged from -9 to +35 degrees with a mean of +12.3 degrees. The means were not significantly different either by gender or side. The angle correlated negatively with superior cervical tubercle, intertrochanteric line, and adductor tubercle (P < 0.001), positively with quadrate tubercle (P < 0.001) but not with linea aspera, neck-shaft angle, or length of femur. Bony prominences were significantly more apparent in males. There was no significant association between prominency and side. The torsion seems to be brought about by muscular activity and capsular and ligamentous strain at the hip. This study suggests to clinicians the possibility of correction of torsion defects in certain hip diseases of growing children by suitable alteration in posture of the lower extremity.

Simultaneous occurrence of a severe Morel-Lavallée lesion and gluteal muscle necrosis as a sequela of transcatheter angiographic embolization following pelvic fracture: a case report.

PubMed

Shimizu, Takayoshi; Matsuda, Shuichi; Sakuragi, Atsushi; Tsukie, Tomio; Kawanabe, Keiichi

2015-03-26

Morel-Lavallée lesions are posttraumatic hemolymphatic collections caused by disruption of the interfascial planes between the subcutaneous soft tissue and muscle. Severe peripelvic Morel-Lavallée lesions have rarely been reported in the literature. By contrast, a number of cases of gluteal muscle necrosis following transcatheter angiographic embolization for pelvic fracture have been reported. Each entity can result in severe infection and sepsis, and the mortality rate in such cases is quite high. However, to date, no previous reports have described a case in which these life-threatening entities occurred simultaneously. A 32-year-old Asian man simultaneously developed severe peripelvic Morel-Lavallée lesions and gluteal muscle necrosis with sepsis following transcatheter angiographic embolization after an unstable pelvic fracture. Extremely large skin and soft tissue defects, which were untreatable with any commonly used flaps, were generated after repeated debridement. In addition, a deep-bone infection was suspected in his left fractured iliac bone, while motor function was almost completely lost in his left leg, possibly as a sequela of transcatheter angiographic embolization. As a result of his condition, a left hemipelvectomy was unavoidable. A pedicled fillet flap from his sacrificed left limb was used for the treatment of the defects and to provide a durable base for a prosthesis. Our patient survived and returned to his previous job 24 months after the surgery wearing a prosthetic left leg. As illustrated by the present case, severe peripelvic Morel-Lavallée lesions and gluteal muscle necrosis following transcatheter angiographic embolization can occur simultaneously after unstable pelvic fractures. Physicians should recognize that these entities can result in life-threatening sepsis and, therefore, should attempt to detect them as early as possible. When hemipelvectomy is unavoidable, a pedicled upper and lower leg in-continuity fillet flap may provide satisfactory outcomes.

Is Augmented LISS Plating Biomechanically Advantageous Over Conventional LISS Plating In Unstable Osteoporotic Distal Femoral Fractures?

PubMed

Todorov, Dimitar; Zderic, Ivan; Richards, R Geoff; Lenz, Mark; Knobe, Matthias; Enchev, Dian; Baltov, Asen; Gueorguiev, Boyko; Stoffel, Karl

2018-05-10

Treatment of complex osteoporotic distal femur fractures with the Less Invasive Stabilization System (LISS) has been associated with high complication rates. The aim of this study was to investigate the biomechanical competence of two different techniques of augmented versus conventional LISS plating. Unstable distal femoral fracture AO/OTA 33-A3 was created via osteotomies in artificial femora simulating osteoporotic bone. Three study groups, consisting of 10 specimens each, were created for instrumentation with either LISS plate, LISS plate with additional polylactide intramedullary graft, or LISS plate plus medial locking plate (double plating). All specimens were non-destructively tested under axial (20-150N) and torsional (0-4Nm) quasi-static loading. Each construct was tested with two different working length (WL) configurations (long and short) of the LISS plate. Relative movements between the most medial superior and inferior osteotomy aspects were investigated via three-dimensional motion tracking analysis. Double plating revealed significantly smaller longitudinal and shear displacement than the other two techniques (P≤0.001). In addition, LISS plus graft fixation was with significantly less longitudinal displacement in comparison to conventional LISS plating (P < 0.001). Long WL resulted in significantly higher longitudinal and shear displacement compared to short WL for LISS and LISS plus graft (P≤0.032), but not for double plating (P > 0.999). In conclusion, intramedullary grafting resulted in significantly increased fracture stability under axial loading in comparison to conventional LISS plating. Although it was not efficient enough to provide comparable stability to double plating, intramedullary grafting may be considered as a useful biological alternative to the latter in a surgeon's armamentarium. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Biologic plating of unstable distal radial fractures.

PubMed

Kwak, Jae-Man; Jung, Gu-Hee

2018-04-14

Volar locking plating through the flexor carpi radialis is a well-established technique for treating unstable distal radial fractures, with few reported complications. In certain circumstances, including metaphyseal comminuted fractures, bridge plating through a pronator quadratus (PQ)-sparing approach may be required to preserve the soft tissue envelope. This study describes our prospective experience with bridge plating through indirect reduction. Thirty-three wrists (four 23A2, six 23A3, 15 23C1, and eight 23C2) underwent bridge plating through a PQ-sparing approach with indirect reduction from June 2006 to December 2010. Mean patient age was 56.8 years (range, 25-83 years), and the mean follow-up period was 47.5 months (range, 36-84 months). Changes in radiologic parameters (volar tilt, radial inclination, radial length, and ulnar variance) were analyzed, and functional results at final follow-up were evaluated by measuring the Modified Mayo Wrist Score (MMWS) and Modified Gartland-Werley Score (MGWS). All wrists achieved bone healing without significant complications after a single operation. At final follow-up, radial length was restored from an average of 3.7 mm to 11.0 mm, as were radial inclination, from 16.4° to 22.5°, and volar tilt, from - 9.1° to 5.5°. However, radial length was overcorrected in three wrists, and two experienced residual dorsal tilt. Excellent and good results on the MGWS were achieved in 30 wrists (90.9%). The average MMWS outcome was 92.6 (range, 75-100). Our experience with bridge plating was similar to that previously reported in the earlier publications. Compared with the conventional technique, bridge plating through a PQ-sparing approach may help in managing metaphyseal comminuted fractures of both cortices with a reduced radio-ulnar index.

Finite Element Analysis and Biomechanical Comparison of Short Posterior Spinal Instrumentation with Divergent Bridge Construct versus Parallel Tension Band Construct for Thoracolumbar Spine Fractures

PubMed Central

Ouellet, Jean A.; Richards, Corey; Sardar, Zeeshan M.; Giannitsios, Demetri; Noiseux, Nicholas; Strydom, Willem S.; Reindl, Rudy; Jarzem, Peter; Arlet, Vincent; Steffen, Thomas

2013-01-01

The ideal treatment for unstable thoracolumbar fractures remains controversial with posterior reduction and stabilization, anterior reduction and stabilization, combined posterior and anterior reduction and stabilization, and even nonoperative management advocated. Short segment posterior osteosynthesis of these fractures has less comorbidities compared with the other operative approaches but settles into kyphosis over time. Biomechanical comparison of the divergent bridge construct versus the parallel tension band construct was performed for anteriorly destabilized T11–L1 spine segments using three different models: (1) finite element analysis (FEA), (2) a synthetic model, and (3) a human cadaveric model. Outcomes measured were construct stiffness and ultimate failure load. Our objective was to determine if the divergent pedicle screw bridge construct would provide more resistance to kyphotic deforming forces. All three modalities showed greater stiffness with the divergent bridge construct. The FEA calculated a stiffness of 21.6 N/m for the tension band construct versus 34.1 N/m for the divergent bridge construct. The synthetic model resulted in a mean stiffness of 17.3 N/m for parallel tension band versus 20.6 N/m for the divergent bridge (p = 0.03), whereas the cadaveric model had an average stiffness of 15.2 N/m in the parallel tension band compared with 18.4 N/m for the divergent bridge (p = 0.02). Ultimate failure load with the cadaveric model was found to be 622 N for the divergent bridge construct versus 419 N (p = 0.15) for the parallel tension band construct. This study confirms our clinical experience that the short posterior divergent bridge construct provides greater stiffness for the management of unstable thoracolumbar fractures. PMID:24436856

Displaced Neer Type IIB distal-third clavicle fractures-Long-term clinical outcome after plate fixation and additional screw augmentation for coracoclavicular instability.

PubMed

Tiefenboeck, Thomas M; Boesmueller, Sandra; Binder, Harald; Bukaty, Adam; Tiefenboeck, Michael M; Joestl, Julian; Hofbauer, Marcus; Ostermann, Roman C

2017-01-23

Unstable Neer Type IIB fractures require meticulous surgical treatment. Thus, the aim of this study was to present long-term outcomes after plate fixation and minimally invasive coracoclavicular (CC) stabilization using screw fixation. A consecutive series of patients with unstable Neer Type IIB displaced clavicle fractures, treated by open reduction and internal fixation (ORIF) with a plate and additional screw fixation for coracoclavicular ligament instability, was reviewed in order to determine long-term clinical and radiological outcome. Seven patients, six males and one female, with a mean age of 37 ± 8 years (median: 36 years; range, 28-51 years), were evaluated. At latest follow-up, after a mean of 67 months (range, 11-117 months), patients presented with the following mean scores: DASH: 0.57, ASES: 98.81, UCLA: 34.29, VAS: 0.43, Simple Shoulder Test: 11.57. However, two complications were observed: one case of implant loosening and one non-union. There were no differences observed between the CC distances comparing postoperative X-rays to those in final follow-up. In 25% of our patients early postoperative complications occurred. In all patients reoperation was necessary to remove the implanted screw. The results of the present study indicate that the treatment of Neer Type IIB lateral clavicle fractures with ORIF using a plate and additional CC screw fixation, leads to satisfying clinical and radiological outcomes in the long-term. However, considering an early postoperative complication rate of 25% and a 100% rate of secondary surgery due to removal of the CC screw does not seem to justify this technique anymore.

Surface recrystallization of polyethylene extended-chain crystals.

PubMed

Wunderlich, B; Melillo, L

1966-12-09

Rough fracture surfaces of extended-chain polyethylene crystals become unstable at temperatures below the bulk melting point. There is no way for the extended chains, which are up to 20,000 methylene units long, to change position without collapse. As a result, the rough surfaces smooth out on heating by covering themselves with oriented folded-chain lamellae.

Ankle Injury Management (AIM): design of a pragmatic multi-centre equivalence randomised controlled trial comparing Close Contact Casting (CCC) to Open surgical Reduction and Internal Fixation (ORIF) in the treatment of unstable ankle fractures in patients over 60 years.

PubMed

Willett, Keith; Keene, David J; Morgan, Lesley; Gray, Bridget; Handley, Robert; Chesser, Tim; Pallister, Ian; Tutton, Elizabeth; Knox, Christopher; Lall, Ranjit; Briggs, Andrew; Lamb, Sarah E

2014-03-12

Ankle fractures account for 9% of all fractures with a quarter of these occurring in adults over 60 years. The short term disability and long-term consequences of this injury can be considerable. Current opinion favours open reduction and internal fixation (ORIF) over non-operative treatment (fracture manipulation and the application of a standard moulded cast) for older people. Both techniques are associated with complications but the limited published research indicates higher complication rates of fracture malunion (poor position at healing) with casting. The aim of this study is to compare ORIF with a modification of existing casting techniques, Close Contact Casting (CCC). We propose that CCC may offer an equivalent functional outcome to ORIF and avoid the risks associated with surgery. This study is a pragmatic multi-centre equivalence randomised controlled trial. 620 participants will be randomised to receive ORIF or CCC after sustaining an isolated displaced unstable ankle fracture. Participants will be recruited from a minimum of 20 National Health Service (NHS) acute hospitals throughout England and Wales. Participants will be aged over 60 years and be ambulatory prior to injury. Follow-up will be at six weeks and six months after randomisation. The primary outcome is the Olerud & Molander Ankle Score, a functional patient reported outcome measure, at 6 months. Follow-up will also include assessments of mobility, ankle range of movement, health related quality of life and complications. The six-month follow-up will be conducted face-to-face by an assessor blinded to the allocated intervention. A parallel economic evaluation will consider both a health service and a broader societal perspective including the individual and their family. In order to explore patient experience of their treatment and recovery, a purposive sample of 40 patients will also be interviewed using a semi-structured interview schedule between 6-10 weeks post treatment. This multicentre study was open to recruitment July 2010 and recruitment is due to be completed in December 2013. Current Controlled Trials ISRCTN04180738.

Malleolar fractures and their ligamentous injury equivalents have similar outcomes in supination-external rotation type IV fractures of the ankle treated by anatomical internal fixation.

PubMed

Berkes, M B; Little, M T M; Lazaro, L E; Sculco, P K; Cymerman, R M; Daigl, M; Helfet, D L; Lorich, D G

2012-11-01

It has previously been suggested that among unstable ankle fractures, the presence of a malleolar fracture is associated with a worse outcome than a corresponding ligamentous injury. However, previous studies have included heterogeneous groups of injury. The purpose of this study was to determine whether any specific pattern of bony and/or ligamentous injury among a series of supination-external rotation type IV (SER IV) ankle fractures treated with anatomical fixation was associated with a worse outcome. We analysed a prospective cohort of 108 SER IV ankle fractures with a follow-up of one year. Pre-operative radiographs and MRIs were undertaken to characterise precisely the pattern of injury. Operative treatment included fixation of all malleolar fractures. Post-operative CT was used to assess reduction. The primary and secondary outcome measures were the Foot and Ankle Outcome Score (FAOS) and the range of movement of the ankle. There were no clinically relevant differences between the four possible SER IV fracture pattern groups with regard to the FAOS or range of movement. In this population of strictly defined SER IV ankle injuries, the presence of a malleolar fracture was not associated with a significantly worse clinical outcome than its ligamentous injury counterpart. Other factors inherent to the injury and treatment may play a more important role in predicting outcome.

Determining the Role of Sost and Sostdc1 During Fracture Healing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yee, Cristal Sook Ngei

The bone is a dynamic organ, often changing throughout the course of the human lifespan with its continuous remodeling, laying down new bone and resorbing old bone. With age, the bone becomes increasingly porous and mechanically unstable, leading to the development of osteoporosis in some individuals. Elderly patients with osteoporosis are at an increased risk of fracturing their bones which contributes to a higher mortality rate. Recent studies have revealed that type 1 diabetic mellitus (T1DM) patients also have an osteoporotic bone phenotype and impaired fracture healing, independent of age. Currently, there is a lack of available treatments that canmore » improve impaired healing and directly enhance bone formation. Therefore, there is a great need for developing new therapies that can not only aid type 1 diabetic patients with osteoporosis to improve bone phenotype, but that could also aid patients with difficult or impaired fracture healing. In this thesis, I will be discussing the role of Wnt signaling and Sclerostin, a Wnt antagonist that negatively regulates bone formation, in the content of fracture repair.« less

Patterns of triangular fibrocartilage complex (TFCC) injury associated with severely dorsally displaced extra-articular distal radius fractures.

PubMed

Scheer, Johan H; Adolfsson, Lars E

2012-06-01

The aim of the study was to examine triangular fibrocartilage (TFCC) injury patterns associated with unstable, extra-articular dorsally displaced distal radius fractures. Twenty adult patients with an Arbeitsgemeinschaft für Osteosynthesefragen (AO), type A2 or A3, distal radius fracture with an initial dorsal angulation greater than 20° were included. Nine had a tip fracture (distal to the base) of the ulnar styloid and 11 had no such fracture. They were all openly explored from an ulnopalmar approach and TFCC injuries were documented. Eleven patients also underwent arthroscopy and intra-articular pathology was recorded. All patients had TFCC lesions of varying severity, having an extensor carpi ulnaris subsheath avulsion in common. Eighteen out of 20 also displayed deep foveal radioulnar ligament lesions, with decreasingly dorsal fibres remaining. The extent of this foveal injury could not be appreciated by radiocarpal arthroscopy. Severe displacement of an extra-articular radius fracture suggests an ulnar-sided ligament injury to the TFCC. The observed lesions concur with findings in a previous cadaver study. The lesions follow a distinct pattern affecting both radioulnar as well as ulnocarpal stabilisers. Copyright © 2012 Elsevier Ltd. All rights reserved.

The anterolateral acromial approach for fractures of the proximal humerus.

PubMed

Gardner, Michael J; Boraiah, Sreevathsa; Helfet, David L; Lorich, Dean G

2008-02-01

Displaced and unstable fractures of the proximal humerus are notoriously difficult to manage. Successful surgical treatment requires finding the appropriate balance between adequate exposure for reduction and rigid fixation and minimizing soft tissue dissection. The anterolateral acromial approach was developed to allow less invasive treatment of proximal humerus fractures. The plane of the avascular anterior deltoid raphe is utilized, and the axillary nerve is identified and protected. Anterior dissection near the critical blood supply is avoided, substantial muscle retraction is minimized, and the lateral plating zone is directly accessed. Over a 4-year period, 52 patients with acute displaced fractures of the proximal humerus were treated with the anterolateral acromial approach and either a locking plate or an intramedullary nail. Twenty-three patients were evaluated clinically at a minimum follow-up of 1 year (average, 28 months) by clinical examination for range of motion and nerve function and a QuickDASH score. There were no axillary nerve deficits postoperatively related to the approach, and the average QuickDASH score was 25.2 (0, best; 100, worst). This approach allowed direct access to the lateral fracture planes for fracture reduction and plate placement or safe nail and interlocking screw placement.

Chest wall stabilization in trauma patients: why, when, and how?

PubMed Central

White, Thomas W.

2018-01-01

Blunt trauma to the chest wall and rib fractures are remarkably frequent and are the basis of considerable morbidity and possible mortality. Surgical remedies for highly displaced rib fractures, especially in cases of flail chest, have been undertaken intermittently for more than 50 years. Rib-specific plating systems have started to be used in the last 10 years. These have ushered in the modern era of rib repair with chest wall stabilization (CWS) techniques that are safer, easier to perform, and more efficient. Recent consensus statements have sought to define the indications and contraindications, as well as the when, the how, and the technical details of CWS. Repair should be considered for patients who have three or more displaced rib fractures or a flail chest, whether or not mechanical ventilation is required. Additional candidates include patients who fail non-operative management irrespective of fracture pattern and those with rib fractures who need thoracic procedures for other reasons. Traditionally, unstable spine fracture and severe traumatic brain injury are definite contraindications. Pulmonary contusion’s role in the decision to perform CWS remains controversial. A range of rib-specific plating systems are now commercially available. PMID:29744222

Open reduction of nasal bone fractures through an intercartilaginous incision.

PubMed

Kim, Ji Heui; Lee, Jun Ho; Hong, Seok Min; Park, Chan Hum

2013-01-01

Open reduction through an intercartilaginous incision was useful for treating delayed-diagnosed nasal bone fractures because it resulted in a successful outcome with minimal complications. Nasal bone fractures are generally managed with closed reduction, which is usually inadequate and results in airway obstruction with a delayed diagnosis of nasal bone fracture when bone healing and fibrotic adhesions around the bone fragment have progressed. This study investigated the surgical outcome of open reduction through an intercartilaginous incision for delayed-diagnosis nasal bone fractures. The study enrolled 18 patients who underwent open reduction through an intercartilaginous incision to correct delayed-diagnosis nasal bone fractures. Three independent otorhinolaryngologists evaluated the outcomes 4-35 months (average 12.7 months) postoperatively as excellent, fair or poor. The time from injury to surgery was 11-39 days (20-39 days in adults and 11-30 days in children). The 18 cases included 16 primary repairs and two revisions. A Kirschner wire was inserted in six (33.3%) patients who had unstable reduced nasal bones. Postoperatively, l5 (83%) patients had excellent results, two (11%) had fair, and one (6%) had a poor outcome. No patient experienced any complication.

The posterior two-portal approach for reconstruction of scapula fractures: results of 39 patients.

PubMed

Pizanis, A; Tosounidis, G; Braun, C; Pohlemann, T; Wirbel, R J

2013-11-01

The purpose of this study was to describe the so-called posterior two-portal approach to the scapula in detail and to investigate the clinical outcome of patients with displaced glenoid and scapular neck fractures who were surgically treated using this approach. From February 1992 to August 2008, 39 patients (30 men and nine women; mean age: 53 years) with scapular fractures underwent surgical fixation at our institution. Thirty-three patients had glenoid fractures and six had unstable scapular neck fractures. All patients were treated via the two-portal approach. The reduction was evaluated radiographically, and the clinical results were analysed using the Constant score. The mean follow-up period was 78 months (range: 6-168). In 24 of the 33 glenoid fractures, the reduction was anatomical. The mean Constant score was 82.3 (range: 35-100) points. In one case, an early postoperative wound infection was cured by local revision, and one patient developed posttraumatic osteoarthritis of the acromioclavicular joint after 2 years. Only one patient developed specific glenohumeral degeneration after non-anatomical reduction. The posterior two-portal approach allows for a good visualisation of the posterior scapular neck and the glenoid area, facilitating the reduction and safe internal fixation of dislocated scapular neck and glenoid fractures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Frictional stability-permeability relationships for fractures in shales: Friction-Permeability Relationships

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, Yi; Elsworth, Derek; Wang, Chaoyi

There is wide concern that fluid injection in the subsurface, such as for the stimulation of shale reservoirs or for geological CO 2 sequestration (GCS), has the potential to induce seismicity that may change reservoir permeability due to fault slip. However, the impact of induced seismicity on fracture permeability evolution remains unclear due to the spectrum of modes of fault reactivation (e.g., stable versus unstable). As seismicity is controlled by the frictional response of fractures, we explore friction-stability-permeability relationships through the concurrent measurement of frictional and hydraulic properties of artificial fractures in Green River shale (GRS) and Opalinus shale (OPS).more » We observe that carbonate-rich GRS shows higher frictional strength but weak neutral frictional stability. The GRS fracture permeability declines during shearing while an increased sliding velocity reduces the rate of permeability decline. By comparison, the phyllosilicate-rich OPS has lower friction and strong stability while the fracture permeability is reduced due to the swelling behavior that dominates over the shearing induced permeability reduction. Hence, we conclude that the friction-stability-permeability relationship of a fracture is largely controlled by mineral composition and that shale mineral compositions with strong frictional stability may be particularly subject to permanent permeability reduction during fluid infiltration.« less

Evaluation and treatment recommendations for acute injuries to the ankle syndesmosis without associated fracture.

PubMed

Miller, Timothy L; Skalak, Timothy

2014-02-01

Ankle ligamentous injuries are commonly seen in athletes in a variety of sports. Surveys of physicians and trainers of professional sports teams have identified syndesmotic injuries as among the most difficult to treat. In particular, injuries of the ankle syndesmosis have been strongly linked with a prolonged recovery and increased time to return to play. Due to sudden external rotation with the tibiotalar joint in dorsiflexion, these structures are commonly injured in association with fractures of the distal fibula. Surgery is indicated in cases with associated fractures and ligamentous instability, but optimal treatment for syndesmosis injuries without an associated fracture is less clear. A thorough history and physical examination, as well as appropriate imaging, are necessary to effectively diagnose and classify the injury. For stable injuries, short-term immobilization and functional rehabilitation is recommended. Unstable Grade 2 and 3 injuries require surgical fixation. Debate currently exists over rigid screw fixation versus suture button techniques as the ideal fixation method.

The role of total elbow arthroplasty in traumatology.

PubMed

Mansat, P; Bonnevialle, N; Rongières, M; Bonnevialle, P

2014-10-01

Fractures of the distal humerus account for 5% of osteoporotic fractures in subjects older than 60 years. A history of osteoporosis, co-morbidities, and joint comminution make their management difficult. The therapeutic options are limited to functional treatments, osteosynthesis, or either partial or total arthroplasty. Functional treatment of distal humerus fractures in the elderly subject provide inconsistent results, often with persistence of pain with a stiff or unstable elbow. Osteosynthesis remains the reference treatment for these fractures, following the principle of stable and rigid osteosynthesis allowing early mobilization. However, joint comminution and a history of osteoporosis occasionally make it impossible to meet this objective, with a considerable rate of complications and surgical revisions. Total elbow arthroplasty remains an alternative to osteosynthesis with very satisfactory immediate results restoring a painless, stable, and functional elbow. These results seem reproducible and sustainable over time. The complication rate is not uncommon with an approximately 10% surgical revision rate. Elbow hemiarthroplasty remains to be validated in this indication. V. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Atypical distal radial fractures in children.

PubMed

Kiely, Paul D; Kiely, Patrick J; Stephens, Micheal M; Dowling, Frank E

2004-05-01

In a prospective study of paediatric injuries secondary to the use of the non-motorized microscooter, we found a high rate of upper limb trauma, and a distinct injury associated with the scooter. The most common single injury was a fracture of the distal third of radius and ulna, characterized by volar angulation of the distal fragment. This injury, akin to the Smiths fracture in adults, was predictive of scooter use in all cases. This pattern of injury was not repeated by any another mechanism of injury during the course of the study period. The mechanism of injury, seemingly specific to the scooter, is produced by a fall while continuing to clutch the handlebars, leading to palmar flexion and pronation of the wrist as they strike the ground. Fourteen children required admission and manipulation under anaesthesia. Four of these patients subsequently needed remanipulation under anaesthesia. This study suggests that the scooter is associated with a forearm fracture which is both distinctive and unstable.

Peculiar Traits of Coarse AP (Briefing Charts)

DTIC Science & Technology

2014-12-01

coarse AP Bircumshaw, Newman Active centers are sources of AP decomposition gases AP low temperature decomposition (LTD) Most unstable AP particles ...delay before coarse AP ejection *Coarse AP particle flame retardancy 19 Air Force Research Laboratory Distribution A: Approved for public release...distribution unlimited. PA clearance #. Combustion bomb trials 2 AP phase change may enable coarse particle breakage Fractured coarse AP ejection agrees

Close Contact Casting vs Surgery for Initial Treatment of Unstable Ankle Fractures in Older Adults: A Randomized Clinical Trial.

PubMed

Willett, Keith; Keene, David J; Mistry, Dipesh; Nam, Julian; Tutton, Elizabeth; Handley, Robert; Morgan, Lesley; Roberts, Emma; Briggs, Andrew; Lall, Ranjit; Chesser, Timothy J S; Pallister, Ian; Lamb, Sarah E

2016-10-11

Ankle fractures cause substantial morbidity in older persons. Surgical fixation is the contemporary intervention but is associated with infection and other healing complications. To determine whether initial fracture treatment with close contact casting, a molded below-knee cast with minimal padding, offers outcome equivalent to that with immediate surgery, with fewer complications and less health resource use. This was a pragmatic, equivalence, randomized clinical trial with blinded outcome assessors. A pilot study commenced in May 2004, followed by multicenter recruitment from July 2010 to November 2013; follow-up was completed May 2014. Recruitment was from 24 UK major trauma centers and general hospitals. Participants were 620 adults older than 60 years with acute, overtly unstable ankle fracture. Exclusions were serious limb or concomitant disease or substantial cognitive impairment. Participants were randomly assigned to surgery (n = 309) or casting (n = 311). Casts were applied in the operating room under general or spinal anesthesia by a trained surgeon. The primary 6-month, per-protocol outcome was the Olerud-Molander Ankle Score at 6 months (OMAS; range, 0-100; higher scores indicate better outcomes and fewer symptoms), equivalence prespecified as ±6 points. Secondary outcomes were quality of life, pain, ankle motion, mobility, complications, health resource use, and patient satisfaction. Among 620 adults (mean age, 71 years; 460 [74%] women) who were randomized, 593 (96%) completed the study. Nearly all participants (579/620; 93%) received allocated treatment; 52 of 275 (19%) who initially received casting later converted to surgery, which was allowable in the casting treatment pathway to manage early loss of fracture reduction. At 6 months, casting resulted in ankle function equivalent to that with surgery (OMAS score, 66.0 [95% CI, 63.6-68.5] for surgery vs 64.5 [95% CI, 61.8-67.2] for casting; mean difference, -0.6 [95% CI, -3.9 to 2.6]; P for equivalence = .001). Infection and wound breakdown were more common with surgery (29/298 [10%] vs 4/275 [1%]; odds ratio [OR], 7.3 [95% CI, 2.6-20.2]), as were additional operating room procedures (18/298 [6%] for surgery and 3/275 [1%] for casting; OR, 5.8 [95% CI, 1.8-18.7]). Radiologic malunion was more common in the casting group (38/249 [15%] vs 8/274 [3%] for surgery; OR, 6.0 [95% CI, 2.8-12.9]). Casting required less operating room time compared with surgery (mean difference [minutes/participant], -54 [95% CI, -58 to -50]). There were no significant differences in other secondary outcomes: quality of life, pain, ankle motion, mobility, and patient satisfaction. Among older adults with unstable ankle fracture, the use of close contact casting compared with surgery resulted in similar functional outcomes at 6 months. Close contact casting may be an appropriate treatment for such patients. isrctn.com Identifier: ISRCTN04180738.

Slow Recovery of Weight Bearing After Stabilization of Long-Bone Fractures Using Elastic Stable Intramedullary Nails in Children

PubMed Central

Lardelli, Patrizia; Frech-Dörfler, Martina; Holland-Cunz, Stefan; Mayr, Johannes

2016-01-01

Abstract Stabilization of diaphyseal long-bone fractures using elastic stable intramedullary nails (ESIN) in children promises early mobilization and rapid resumption of full weight bearing. We evaluated the duration of postoperative functional rehabilitation after ESIN, measured by the time from stabilization until first partial weight bearing, full weight bearing, and resumption of school sports. Fifty children with unstable, displaced fractures of the femur or lower leg treated with ESIN between 2002 and 2012 were included in this retrospective analysis. We classified fractures according to the pediatric comprehensive classification of fractures (PCCF). Thirty-five children sustained a femur fracture, and 15 children had a fracture of the lower leg or tibia. The surgeons in charge applied an additional plaster cast in 7 of 15 children who suffered a lower leg fracture. The postoperative time interval until full weight bearing in the group of children who had suffered transverse or short oblique femur fractures was significantly shorter (median: 4.4 weeks; range: 0.1–9.1 weeks) than that in the group who had sustained more complex fracture patterns (median: 6.8 weeks; range: 2.9–13.9 weeks; P = 0.04). Similarly, transverse and short oblique lower leg and tibia fractures required less time until full weight bearing (median: 4.1 weeks; range 2.7–6.0 weeks) than complex lower leg fractures (median: 6.1 weeks; range: 1.3–12.9 weeks; P = 0.04). ESIN proved fairly effective in restoring full weight bearing in transverse or short oblique fractures of the lower extremities but was less effective in complex fractures. PMID:26986106

Slow Recovery of Weight Bearing After Stabilization of Long-Bone Fractures Using Elastic Stable Intramedullary Nails in Children.

PubMed

Lardelli, Patrizia; Frech-Dörfler, Martina; Holland-Cunz, Stefan; Mayr, Johannes

2016-03-01

Stabilization of diaphyseal long-bone fractures using elastic stable intramedullary nails (ESIN) in children promises early mobilization and rapid resumption of full weight bearing. We evaluated the duration of postoperative functional rehabilitation after ESIN, measured by the time from stabilization until first partial weight bearing, full weight bearing, and resumption of school sports. Fifty children with unstable, displaced fractures of the femur or lower leg treated with ESIN between 2002 and 2012 were included in this retrospective analysis. We classified fractures according to the pediatric comprehensive classification of fractures (PCCF). Thirty-five children sustained a femur fracture, and 15 children had a fracture of the lower leg or tibia. The surgeons in charge applied an additional plaster cast in 7 of 15 children who suffered a lower leg fracture. The postoperative time interval until full weight bearing in the group of children who had suffered transverse or short oblique femur fractures was significantly shorter (median: 4.4 weeks; range: 0.1-9.1 weeks) than that in the group who had sustained more complex fracture patterns (median: 6.8 weeks; range: 2.9-13.9 weeks; P = 0.04). Similarly, transverse and short oblique lower leg and tibia fractures required less time until full weight bearing (median: 4.1 weeks; range 2.7-6.0 weeks) than complex lower leg fractures (median: 6.1 weeks; range: 1.3-12.9 weeks; P = 0.04). ESIN proved fairly effective in restoring full weight bearing in transverse or short oblique fractures of the lower extremities but was less effective in complex fractures.

Cleavage fracture in high strength low alloy weld metal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bose, W.W.; Bowen, P.; Strangwood, M.

1996-12-31

The present investigation gives an evaluation of the effect of microstructure on the cleavage fracture process of High Strength Low Alloy (HSLA) multipass weld metals. With additions of alloying elements, such as Ti, Ni, Mo and Cr, the microstructure of C-Mn weld metal changes from the classical composition, i.e., allotriomorphic ferrite with acicular ferrite and Widmanstaetten ferrite, to bainite and low carbon martensite. Although the physical metallurgy of some HSLA weld metals has been studied before, more work is necessary to correlate the effect of the microstructure on the fracture behavior of such weld metals. In this work detailed microstructuralmore » analysis was carried out using optical and electron (SEM and TEM) microscopy. Single edge notched (SEN) bend testpieces were used to assess the cleavage fracture stress, {sigma}{sub F}. Inclusions beneath the notch surface were identified as the crack initiators of unstable cleavage fracture. From the size of such inclusions and the value of tensile stress predicted at the initiation site, the effective surface energy for cleavage was calculated using a modified Griffth energy balance for a penny shape crack. The results suggest that even though inclusions initiate cleavage fracture, the local microstructure may play an important role in the fracture process of these weld metals. The implications of these observations for a quantitative theory of the cleavage fracture of ferritic steels is discussed.« less

Should the tip-apex distance (TAD) rule be modified for the proximal femoral nail antirotation (PFNA)? A retrospective study.

PubMed

Nikoloski, Andrej N; Osbrough, Anthony L; Yates, Piers J

2013-10-17

Unstable proximal femoral fractures are common and challenging for the orthopaedic surgeon. Often, these are treated with intramedullary nails. The most common mode of failure of any device to treat these fractures is cut-out. The Synthes proximal femoral nail antirotation (PFNA) is unique because it is the only proximal femoral intramedullary nail which employs a helical blade in lieu of a lag screw. The optimal tip-apex distance is 25 mm or less for a dynamic hip screw. The optimal blade tip placement is not known for the PFNA. The aim of this study is to determine if the traditional tip-apex distance rule (<25 mm) applies to the PFNA. A retrospective study of all proximal femoral fractures treated with the PFNA in Western Australian public teaching hospitals between August 2006 and October 2007 was performed. Cases were identified from company and theatre implant use records. Patient demographic data was obtained from hospital records. Fractures were classified according to Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation. Fracture reduction, distal locking type and blade position within the head (tip-apex distance and Cleveland zone) were recorded from the intraoperative and immediate postoperative radiographs. Postoperative radiographs obtained in the routine treatment of patients were studied for review looking primarily for cut-out. Clinical outcomes were measured with the Oxford hip score. One hundred eighty-eight PFNAs were implanted during the study period, with 178 cases included in this study. Ninety-seven patients could be followed up clinically. There were 18 surgical implant-related failures (19%). The single most common mode of failure was cut-out in six cases (6.2%). Three cut-outs (two medial perforation and one varus collapse) occurred with tip-apex distance (TAD) less than 20 mm. There was no cut-out in cases where the TAD was from 20-30 mm. There were three implant-related failures (nail fracture, missed nail and loose locking screw), four implant-related femoral fractures, two non-unions, two delayed unions and one loss of reduction. The PFNA is a suitable fixation device for the treatment of unstable proximal femoral fractures. There were still a relatively large number of cut-outs, and the tip-apex distance in the failures showed a bimodal distribution, not like previously demonstrated with dynamic hip screw. We propose that the helical blade behaves differently to a screw, and placement too close to the subchondral bone may lead to penetration through the head.

Fractures of the manubrium sterni: treatment options and a possible classification of different types of fractures

PubMed Central

Krinner, Sebastian; Oppel, Pascal; Grupp, Sina; Schulz-Drost, Melanie; Hennig, Friedrich F.; Langenbach, Andreas

2018-01-01

Background Sternum fractures are mostly located on the sternal corpus, seldom on the manubrium. Fractures of the sternal manubrium are, however, more frequently associated with severe concomitant injuries of thoracic organs, and therefore deserve special attention. In addition, in its function as a capstone in between the anterior chest wall and the shoulder girdle, it is exposed to a multiplicity of forces. Therefore the questions arise what types of fractures are observed in today’s clinical practice, how to classify them and which treatment options are available. This study reports on different types of fractures which involve the manubrium sterni. Methods Between January 2012 and October 2014, data was collected from all severely injured patients (ISS ≥16), which received a CT scan of the thorax in our Level-I-Trauma Center and retrospectively analyzed concerning sternal fractures. Fracture type, collateral injuries, age, and information about the circumstances of the accident were noted. Results Of 890 evaluable patients, 154 (17.3%) had a fracture of the sternum and 23 (2.6%) of the manubrium. Fractures of the manubrium appeared in following types: A-type—transverse fracture (n=11) in 1st intercostal space by direct blunt trauma or flexion of the torso with sagittal instability; B-type—oblique fracture (n=9) by seat belt injury with rotatory instability; C-type—combined, more fragmentary fracture (n=3) by direct blunt trauma with simultaneous flexion of the torso and multi directional instability. Fractures only little dislocation were treated conservatively, and unstable fractures were surgically stabilized (n=10). Conclusions In summary, three main types of fractures could be found. A-type fractures were stabilized with a longitudinal plate osteosynthesis and B-type fractures with transverse positioned plates. To treat complex C-type fractures, plates with a T- or H-form could be a good solution. Level of evidence: Level III retrospective prognostic cohort study PMID:29707289

Facial Fracture Management in Northwest Nigeria

PubMed Central

Taiwo, Abdurrazaq Olanrewaju; Soyele, Olujide Oladele; Godwin, Ndubuizi Ugochukwu; Ibikunle, Adebayo Aremu

2013-01-01

Background: Facial fracture is gradually become a public health problem in our community due to the attendant morbidity and mortality. Hence, the aim of this study was to determine the pattern of facial fracture in Dental and Maxillofacial Surgery Department of Usmanu Danfodiyo University Teaching Hospital. This cross-sectional study was undertaken to provide information regarding gender, age, etiology, and diagnosis of patients with maxillofacial fractures. Materials and Methods: A 1-year review of patients diagnosed and treated for facial fractures in Usmanu Danfodiyo University Teaching Hospital between January 2011 and December 2011. The diagnosis was based on radiographic data and clinical examination. The main analysis outcome measures were etiology, age, gender, site, and treatment. Data were organized and presented by means of descriptive statistics and Pearson's Chi-square test. The level of significance adopted was 5%. Results: A total of 40 patients were treated in this period. Over 95% were male, 81% were caused by road traffic crash (RTC) and 86.4% were in the 21-30 years group. Most patients (52%) had mandibular fractures, and the most common site was the body. Most patients with midfacial fractures had fractures of the zygomaticomaxillary region (36%), while fractures of the parasymphyseal region were more common in the mandible 156 (31%). The most common treatment for jaw fractures was mandibulomaxillary fixation (MMF). Stable zygomatic complex fractures were reduced (elevated) intraorally, and unstable ones were supported by antral packs. Conclusions: This study highlights facial fractures secondary to RTC as a serious public health problem in our environment. Preventive strategies remain the cheapest way to reduce direct and indirect costs of the sequelae of RTC. It also bring to the fore the necessity to shift to open reduction and internal fixation (ORIF) of fractures. PMID:24741422

Mapping Bone Mineral Density Obtained by Quantitative Computed Tomography to Bone Volume Fraction

NASA Technical Reports Server (NTRS)

Pennline, James A.; Mulugeta, Lealem

2017-01-01

Methods for relating or mapping estimates of volumetric Bone Mineral Density (vBMD) obtained by Quantitative Computed Tomography to Bone Volume Fraction (BVF) are outlined mathematically. The methods are based on definitions of bone properties, cited experimental studies and regression relations derived from them for trabecular bone in the proximal femur. Using an experimental range of values in the intertrochanteric region obtained from male and female human subjects, age 18 to 49, the BVF values calculated from four different methods were compared to the experimental average and numerical range. The BVF values computed from the conversion method used data from two sources. One source provided pre bed rest vBMD values in the intertrochanteric region from 24 bed rest subject who participated in a 70 day study. Another source contained preflight vBMD values from 18 astronauts who spent 4 to 6 months on the ISS. To aid the use of a mapping from BMD to BVF, the discussion includes how to formulate them for purpose of computational modeling. An application of the conversions would be used to aid in modeling of time varying changes in vBMD as it relates to changes in BVF via bone remodeling and/or modeling.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, T.; Shimizu, S.; Ogata, Y.

For the primary coolant piping of PWRs in Japan, cast duplex stainless steel which is excellent in terms of strength, corrosion resistance, and weldability has conventionally been used. The cast duplex stainless steel contains the ferrite phase in the austenite matrix and thermal aging after long term service is known to change its material characteristics. It is considered appropriate to apply the methodology of elastic plastic fracture mechanics for an evaluation of the integrity of the primary coolant piping after thermal aging. Therefore we evaluated the integrity of the primary coolant piping for an initial PWR plant in Japan bymore » means of elastic plastic fracture mechanics. The evaluation results show that the crack will not grow into an unstable fracture and the integrity of the piping will be secured, even when such through wall crack length is assumed to equal the fatigue crack growth length for a service period of up to 60 years.« less

Brittle Fracture In Disordered Media: A Unified Theory

NASA Astrophysics Data System (ADS)

Shekhawat, Ashivni; Zapperi, Stefano; Sethna, James

2013-03-01

We present a unified theory of fracture in disordered brittle media that reconciles apparently conflicting results reported in the literature, as well as several experiments on materials ranging from granite to bones. Our renormalization group based approach yields a phase diagram in which the percolation fixed point, expected for infinite disorder, is unstable for finite disorder and flows to a zero-disorder nucleation-type fixed point, thus showing that fracture has mixed first order and continuous character. In a region of intermediate disorder and finite system sizes, we predict a crossover with mean-field avalanche scaling. We discuss intriguing connections to other phenomena where critical scaling is only observed in finite size systems and disappears in the thermodynamic limit. We present a numerical validation of our theoretical results. We acknowledge support from DOE- BES DE-FG02-07ER46393, ERC-AdG-2011 SIZEFFECT, and the NSF through TeraGrid by LONI under grant TG-DMR100025.

[Odontoid process fracture in elderly patients over 70 years: morbidity, handicap, and role of surgical treatment in a retrospective series of 27 cases].

PubMed

Lefranc, M; Peltier, J; Fichten, A; Desenclos, C; Toussaint, P; Le Gars, D

2009-12-01

Odontoid process fractures of the axis are frequent in elderly patients. However, the impact in terms of handicap and morbidity in this particular population are unknown. The role of surgical treatment remains controversial. We present a retrospective series of patients aged 70 years or older with odontoid fractures treated in our department between 1998 and 2006. Two cohorts were defined (surgery versus conservative) and compared. Morbidity, handicap, and radiographic fusion were analyzed. Twenty-seven patients were treated. The mean age was 80.67 years. Five patients died early during hospitalization. Fractures were type II in 66.7% of the cases and type III in 33.3%. Orthopedic treatment was chosen in 44.4% of the cases. A non-union at the fracture site was found in 33% of the cases and morbidity in 41.7% of the cases was found after a 1-year follow-up. Surgery was performed in 40.7% of the cases. There was 18% non-union and no morbidity after 1-year of follow-up. Morbidity was statistically lower in the surgery group (p=0.037), particularly in cases of type II fracture (p=0.0063); no statistically significant difference was found for non-union at the fracture site (p=0.64) except for type II fractures (p=0.028). Odontoid fractures in the elderly are a very frequent problem. Immediate mortality is still high but appears correlated to associated lesions. Today's treatments must preserve autonomy for these patients. For elderly patients, the treatment must be chosen in relation to the fracture analysis. In our opinion, surgical management is the treatment of choice for unstable fractures (type II). Conservative management is indicated for stable fractures.

[Surgical fixation of rib fractures with clips and titanium bars (STRATOS System). Preliminary experience].

PubMed

Moreno De La Santa Barajas, Pablo; Polo Otero, María Dolores; Delgado Sánchez-Gracián, Carlos; Lozano Gómez, Manuel; Toscano Novella, Alberto; Calatayud Moscoso Del Prado, Julia; Leal Ruiloba, Sonsoles; Choren Durán, Maria L

2010-09-01

Rib fractures are very common in closed chest injuries. The majority of these patients suffer significant pain with movement and cough. The purpose of this study is to assess the usefulness of titanium rib bars and clips in stabilising rib fractures. Twenty-two patients with rib fractures were treated with open reduction and internal fixation between 2008 and 2009. Indications for treatment were defined as; 1) Patients with unstable chest (13 patients), 2) Patients with pain or instability due to rib fractures (6 patients), and 3) Significant traumatic deformities of the chest wall (3 patients). Age, traumatic mechanism, chest and associated injuries, surgical data, complications and follow-up were prospectively analysed. The surgical technique is described. The majority of patients were extubated immediately after surgery. All patients with pain or instability showed a subjective improvement or disappearance of pain after the surgery. Four patients had a wound infection which had to be drained. After 3 months, 55% of the patients had returned to work or normal life. The results in each group are described. Open reduction with internal fixation of rib fractures is a good alternative. The use of titanium rib bars and clips give good clinical results, are easy to apply and have few complications. Copyright © 2010 AEC. Published by Elsevier Espana. All rights reserved.

Open reduction and internal fixation compared to closed reduction and external fixation in distal radial fractures

PubMed Central

Kopylov, Philippe; Geijer, Mats; Tägil, Magnus

2009-01-01

Background and purpose In unstable distal radial fractures that are impossible to reduce or to maintain in reduced position, the treatment of choice is operation. The type of operation and the choice of implant, however, is a matter of discussion. Our aim was to investigate whether open reduction and internal fixation would produce a better result than traditional external fixation. Methods 50 patients with an unstable or comminute distal radius fracture were randomized to either closed reduction and bridging external fixation, or open reduction and internal fixation using the TriMed system. The primary outcome parameter was grip strength, but the patients were followed for 1 year with objective clinical assessment, subjective outcome using DASH, and radiographic examination. Results At 1 year postoperatively, grip strength was 90% (SD 16) of the uninjured side in the internal fixation group and 78% (17) in the external fixation group. Pronation/supination was 150° (15) in the internal fixation group and 136° (20) in the external fixation group at 1 year. There were no differences in DASH scores or in radiographic parameters. 5 patients in the external fixation group were reoperated due to malunion, as compared to 1 in the internal fixation group. 7 other cases were classified as radiographic malunion: 5 in the external fixation group and 2 in the internal fixation group. Interpretation Internal fixation gave better grip strength and a better range of motion at 1 year, and tended to have less malunions than external fixation. No difference could be found regarding subjective outcome. PMID:19857180

Minimally invasive treatment of trochanteric fractures with intramedullary nails. Technique and results.

PubMed

Todor, Adrian; Pojar, Adina; Lucaciu, Dan

2013-01-01

The aim of the study was to evaluate the results of minimally invasive treatment of trochanteric fractures with the use of intramedullary nails. From September 2010 to September 2012 we treated 21 patients with pertrochanteric fractures by a minimally invasive technique using the Gamma 3 (Stryker, Howmedica) nail. There were 13 females and 8 men with a mean age of 74.1 years, ranging from 58 to 88 years. Fractures were classified as being stable (AO type 31-A1) in 5 cases and unstable (AO type 31-A2 and A3) in the rest of 16 cases. Patients were reviewed at 6 weeks and 3 months postoperatively. Mean surgery time was 46.8 minutes and mean hospital stay was 14.9 days. No patients required blood transfusions. During the hospital stay all the patients were mobilized with weight bearing as tolerated. All patients were available for review at 6 weeks, and 2 were lost to the 3 months follow up. 16 patients regained the previous level of activity. This minimally invasive technique using a gamma nail device for pertrochanteric fractures gives reliable good results with excellent preservation of hip function.

7-year follow-up after open reduction and internal screw fixation in Bennett fractures.

PubMed

Leclère, Franck Marie Patrick; Jenzer, Achat; Hüsler, Rolf; Kiermeir, David; Bignion, Dietmar; Unglaub, Frank; Vögelin, Esther

2012-07-01

Bennett fractures are unstable, and, with inadequate treatment, lead to osteoarthritis, weakness and loss of function of the first carpometacarpal joint. This study focuses on long-term functional and radiological outcomes after open reduction and internal fixation. Between June 1997 and December 2005, 24 patients with Bennett fractures were treated with open reduction and internal fixation with screws at our center. Radiological and functional assessments including range of motion of the thumb and pinch and grip strength were performed 4 months post-procedure and at the long-term follow-up, on average 83 months after surgery. Reduction of the Bennett fracture was maintained as it was at the time of the procedure in 96 % of the cases when fixation with two lag screws was performed. At the 4-month follow-up, mean pinch and grip strength reached 92 ± 3 and 89 ± 4 % of the contralateral side, respectively. Long-term follow-up demonstrated no correlation between the accuracy of the fracture reduction and the development of post-traumatic arthritis. Good clinical results could be observed, if successful reduction of the fracture was achieved and maintained. However, there was no correlation between the accuracy of the fracture reduction considering a gap and step <2 mm and the development of arthritis.

A comparative evaluation of dental luting cements by fracture toughness tests and fractography.

PubMed

Ryan, A K; Orr, J F; Mitchell, C A

2001-01-01

In recent years there has been a shift from traditional methods of investigating dental materials to a fracture mechanics approach. Fracture toughness (KIC) is an intrinsic material property which can be considered to be a measure of a material's resistance to crack propagation. Glass-ionomer cements are biocompatible and bioactive dental restorative materials, but they suffer from poor fracture toughness and are extremely susceptible to dehydration. The main objective of this study was to evaluate the fracture toughness of three types of commercially available dental cements (polyacid-modified composite resin, resin-modified and conventional glass ionomer) using a short-rod chevron-notch test and to investigate and interpret the results by means of fractography using scanning electron microscopy. Ten specimens of each cement were fabricated according to manufacturers' instructions, coated in varnish, and stored at ambient laboratory humidity, 100 per cent relative humidity, or in water at 37 degrees C for 7 days prior to preparation for testing. Results indicated that significant differences existed between each group of materials and that the fracture toughness ranged from 0.27 to 0.72 MN/m3/2. It was concluded that the resin-modified glass-ionomer cement demonstrated the highest resistance to crack propagation. Fractographs clearly showed areas of stable and unstable crack growth along the fractured surfaces for the three materials examined.

Ankle Injury Management (AIM): design of a pragmatic multi-centre equivalence randomised controlled trial comparing Close Contact Casting (CCC) to Open surgical Reduction and Internal Fixation (ORIF) in the treatment of unstable ankle fractures in patients over 60 years

PubMed Central

2014-01-01

Background Ankle fractures account for 9% of all fractures with a quarter of these occurring in adults over 60 years. The short term disability and long-term consequences of this injury can be considerable. Current opinion favours open reduction and internal fixation (ORIF) over non-operative treatment (fracture manipulation and the application of a standard moulded cast) for older people. Both techniques are associated with complications but the limited published research indicates higher complication rates of fracture malunion (poor position at healing) with casting. The aim of this study is to compare ORIF with a modification of existing casting techniques, Close Contact Casting (CCC). We propose that CCC may offer an equivalent functional outcome to ORIF and avoid the risks associated with surgery. Methods/Design This study is a pragmatic multi-centre equivalence randomised controlled trial. 620 participants will be randomised to receive ORIF or CCC after sustaining an isolated displaced unstable ankle fracture. Participants will be recruited from a minimum of 20 National Health Service (NHS) acute hospitals throughout England and Wales. Participants will be aged over 60 years and be ambulatory prior to injury. Follow-up will be at six weeks and six months after randomisation. The primary outcome is the Olerud & Molander Ankle Score, a functional patient reported outcome measure, at 6 months. Follow-up will also include assessments of mobility, ankle range of movement, health related quality of life and complications. The six-month follow-up will be conducted face-to-face by an assessor blinded to the allocated intervention. A parallel economic evaluation will consider both a health service and a broader societal perspective including the individual and their family. In order to explore patient experience of their treatment and recovery, a purposive sample of 40 patients will also be interviewed using a semi-structured interview schedule between 6-10 weeks post treatment. Discussion This multicentre study was open to recruitment July 2010 and recruitment is due to be completed in December 2013. Trial registration Current Controlled Trials ISRCTN04180738. PMID:24621174

High resolution monitoring of hydrology and deformation in a unstable slope

NASA Astrophysics Data System (ADS)

Nevers, Pierre; Provost, Floriane; Kromer, Ryan; Bertrand, Catherine; Malet, Jean-Philippe; Marc, Vincent; Gaillardet, Jérôme; Gance, Julien; Abellan, Antonio; Jaboyedoff, Michel

2017-04-01

The Séchilienne landslide is located on the right bank of the Romanche River, South East of Grenoble (Isère, France). The active zone of the gravitational instability involves several millions of cubic meters. The geology consists in fractured hard rocks (micaschists) with double permeability and strong spatial heterogeneities. The deformation of the unstable slope is monitored by on-site extensometric gauges, inclinometers, GNSS and remotely by a terrestrial radar and a total station. Hydro-chemio-mechanical processes controlling the reactivation of the landslide are influenced by the evolution of the landslide deformation in space and time, and the water circulation in the highly heterogeneous fractured media. A hydrogeochemical monitoring of the unsaturated zone in the fractured hard rock has been carried out since 2010. This monitoring is supported by the French Landslide Observatory (OMIV) and consists in continuous measurements of physico-chemical parameters on two groundwater outlets (T°C, EC, flow rate) and weekly samplings of the waters for quality monitoring. Water chemistry is a good proxy to locate in time and space the origin of the infiltrated water. This tool is used to understand the complex relationships between chemical weathering, hydromechanical changes and weakening/deformation of the unstable material. This monitoring indicates a correlation between water chemistry, rainwater infiltration and rock mass deformation highlighting the impacts of rock-water interactions on the landslide dynamics. But a distributed information over area is still needed because the heterogeneities of the slope and the few sampling points currently prevent a detailed understanding of the global mechanisms involved. To better understand and constrain the hydrogeological and hydro-chemio-mechanical behavior of the slope, a multi-method monitoring of a flood wave infiltration has been carried out in early 2016 in order to distinguish possible signals related to significant displacements. Displacements were monitored by a GB-InSAR and a terrestrial laser scanner in order to obtain a global image of the deformation at high frequency (less than 1 hour). Repeated time-lapse geoelectrical profiles along four sections have been acquired each two hours on relevant plots which are suspected to be the main water flow paths from the surface to the depth. Water quality changes were monitored at high frequency in order to provide information on the water residence time. This first dataset gives insight into the moving volumes of rock and fluids. Imagery geophysics identifies a signal of fluid circulation in a fracture with a fast transit. The chemical signal identifies the heterogeneous functioning of the drainage system (drain/low permeable structure) with a fast transit.

Ambient vibrations of unstable rock slopes - insights from numerical modeling

NASA Astrophysics Data System (ADS)

Burjanek, Jan; Kleinbrod, Ulrike; Fäh, Donat

2017-04-01

The recent events in Nepal (2015 M7.8 Gorkha) and New Zealand (2016 M7.8 Kaikoura) highlighted the importance of earthquake-induced landslides, which caused significant damages. Moreover, landslide created dams present a potential developing hazard. In order to reduce the costly consequences of such events it is important to detect and characterize earthquake susceptible rock slope instabilities before an event, and to take mitigation measures. For the characterisation of instable slopes, acquisition of ambient vibrations might be a new alternative to the already existing methods. We present both observations and 3D numerical simulations of the ambient vibrations of unstable slopes. In particular, models of representative real sites have been developed based on detailed terrain mapping and used for the comparison between synthetics and observations. A finite-difference code has been adopted for the seismic wave propagation in a 3D inhomogeneous visco-elastic media with irregular free surface. It utilizes a curvilinear grid for a precise modeling of curved topography and local mesh refinement to make computational mesh finer near the free surface. Topographic site effects, controlled merely by the shape of the topography, do not explain the observed seismic response. In contrast, steeply-dipping compliant fractures have been found to play a key role in fitting observations. Notably, the synthetized response is controlled by inertial mass of the unstable rock, and by stiffness, depth and network density of the fractures. The developed models fit observed extreme amplification levels (factors of 70!) and show directionality as well. This represents a possibility to characterize slope structure and infer depth or volume of the slope instability from the ambient noise recordings in the future.

Angular Stable Miniplate Fixation of Chronic Unstable Scaphoid Nonunion.

PubMed

Schormans, Philip M J; Brink, Peter R G; Poeze, Martijn; Hannemann, Pascal F W

2018-02-01

Background  Around 5 to 15% of all scaphoid fractures result in nonunion. Treatment of long-lasting scaphoid nonunion remains a challenge for the treating surgeon. Healing of scaphoid nonunion is essential for prevention of scaphoid nonunion advanced collapse and the subsequent predictable pattern of radiocarpal osteoarthritis. Purpose  The purpose of this study was to investigate the feasibility of fixation of the scaphoid nonunion with a volar angular stable miniplate and cancellous bone grafting. We hypothesized that this technique could be successful, even in patients with previous surgery for nonunion and in patients with a long duration of nonunion. Patients and Methods  A total of 21 patients enrolled in a single-center prospective cohort study. Healing of nonunion was assessed on multiplanar computed tomography scan of the wrist at a 3-month interval. Functional outcome was assessed by measuring grip strength, range of motion, and by means of the patient-rated wrist and hand evaluation (PRWHE) questionnaire. Results  During follow-up, 19 out of 21 patients (90%) showed radiological healing of the nonunion. The range of motion did not improve significantly. Postoperative PRWHE scores decreased by 34 points. Healing occurred regardless of the length of time of the nonunion (range: 6-183 months) and regardless of previous surgery (38% of patients). Conclusion  Volar angular stable miniplate fixation with autologous cancellous bone grafting is a successful technique for the treatment of chronic unstable scaphoid nonunion, even in patients with long-lasting nonunion and in patients who underwent previous surgery for a scaphoid fracture. Rotational interfragmentary stability might be an important determining factor for the successful treatment of unstable scaphoid nonunion. Level of Evidence  Level IV.

Characterization of Unstable Rock Slopes Through Passive Seismic Measurements

NASA Astrophysics Data System (ADS)

Kleinbrod, U.; Burjanek, J.; Fäh, D.

2014-12-01

Catastrophic rock slope failures have high social impact, causing significant damage to infrastructure and many casualties throughout the world each year. Both detection and characterization of rock instabilities are therefore of key importance. An analysis of ambient vibrations of unstable rock slopes might be a new alternative to the already existing methods, e.g. geotechnical displacement measurements. Systematic measurements have been performed recently in Switzerland to study the seismic response of potential rockslides concerning a broad class of slope failure mechanisms and material conditions. Small aperture seismic arrays were deployed at sites of interest for a short period of time (several hours) in order to record ambient vibrations. Each measurement setup included a reference station, which was installed on a stable part close to the instability. Recorded ground motion is highly directional in the unstable parts of the rock slope, and significantly amplified with respect to stable areas. These effects are strongest at certain frequencies, which were identified as eigenfrequencies of the unstable rock mass. In most cases the directions of maximum amplification are perpendicular to open cracks and in good agreement with the deformation directions obtained by geodetic measurements. Such unique signatures might improve our understanding of slope structure and stability. Thus we link observed vibration characteristics with available results of detailed geological characterization. This is supported by numerical modeling of seismic wave propagation in fractured media with complex topography.For example, a potential relation between eigenfrequencies and unstable rock mass volume is investigated.

Fracture toughness of dentin/resin-composite adhesive interfaces.

PubMed

Tam, L E; Pilliar, R M

1993-05-01

The reliability and validity of tensile and shear bond strength determinations of dentin-bonded interfaces have been questioned. The fracture toughness value (KIC) reflects the ability of a material to resist crack initiation and unstable propagation. When applied to an adhesive interface, it should account for both interfacial bond strength and inherent defects at or near the interface, and should therefore be more appropriate for characterization of interface fracture resistance. This study introduced a fracture toughness test for the assessment of dentin/resin-composite bonded interfaces. The miniature short-rod specimen geometry was used for fracture toughness testing. Each specimen contained a tooth slice, sectioned from a bovine incisor, to form the bonded interface. The fracture toughness of an enamel-bonded interface was assessed in addition to the dentin-bonded interfaces. Tensile bond strength specimens were also prepared from the dentin surfaces of the cut bovine incisors. A minimum of ten specimens was fabricated for each group of materials tested. After the specimens were aged for 24 h in distilled water at 37 degrees C, the specimens were loaded to failure in an Instron universal testing machine. There were significant differences (p < 0.05) between the dental adhesives tested. Generally, both the fracture toughness and tensile bond strength measurements were highest for AllBond 2, intermediate for 3M MultiPurpose, and lowest for Scotchbond 2. Scanning electron microscopy of the fractured specimen halves confirmed that crack propagation occurred along the bond interface during the fracture toughness test. It was therefore concluded that the mini-short-rod fracture toughness test provided a valid method for characterization of the fracture resistance of the dentin-resin composite interface.

Fracture behavior of human molars.

PubMed

Keown, Amanda J; Lee, James J-W; Bush, Mark B

2012-12-01

Despite the durability of human teeth, which are able to withstand repeated loading while maintaining form and function, they are still susceptible to fracture. We focus here on longitudinal fracture in molar teeth-channel-like cracks that run along the enamel sidewall of the tooth between the gum line (cemento-enamel junction-CEJ) and the occlusal surface. Such fractures can often be painful and necessitate costly restorative work. The following study describes fracture experiments made on molar teeth of humans in which the molars are placed under axial compressive load using a hard indenting plate in order to induce longitudinal cracks in the enamel. Observed damage modes include fractures originating in the occlusal region ('radial-median cracks') and fractures emanating from the margin of the enamel in the region of the CEJ ('margin cracks'), as well as 'spalling' of enamel (the linking of longitudinal cracks). The loading conditions that govern fracture behavior in enamel are reported and observations made of the evolution of fracture as the load is increased. Relatively low loads were required to induce observable crack initiation-approximately 100 N for radial-median cracks and 200 N for margin cracks-both of which are less than the reported maximum biting force on a single molar tooth of several hundred Newtons. Unstable crack growth was observed to take place soon after and occurred at loads lower than those calculated by the current fracture models. Multiple cracks were observed on a single cusp, their interactions influencing crack growth behavior. The majority of the teeth tested in this study were noted to exhibit margin cracks prior to compression testing, which were apparently formed during the functional lifetime of the tooth. Such teeth were still able to withstand additional loading prior to catastrophic fracture, highlighting the remarkable damage containment capabilities of the natural tooth structure.

Intra- and interobserver agreement in the classification and treatment of distal third clavicle fractures.

PubMed

Bishop, Julie Y; Jones, Grant L; Lewis, Brian; Pedroza, Angela

2015-04-01

In treatment of distal third clavicle fractures, the Neer classification system, based on the location of the fracture in relation to the coracoclavicular ligaments, has traditionally been used to determine fracture pattern stability. To determine the intra- and interobserver reliability in the classification of distal third clavicle fractures via standard plain radiographs and the intra- and interobserver agreement in the preferred treatment of these fractures. Cohort study (Diagnosis); Level of evidence, 3. Thirty radiographs of distal clavicle fractures were randomly selected from patients treated for distal clavicle fractures between 2006 and 2011. The radiographs were distributed to 22 shoulder/sports medicine fellowship-trained orthopaedic surgeons. Fourteen surgeons responded and took part in the study. The evaluators were asked to measure the size of the distal fragment, classify the fracture pattern as stable or unstable, assign the Neer classification, and recommend operative versus nonoperative treatment. The radiographs were reordered and redistributed 3 months later. Inter- and intrarater agreement was determined for the distal fragment size, stability of the fracture, Neer classification, and decision to operate. Single variable logistic regression was performed to determine what factors could most accurately predict the decision for surgery. Interrater agreement was fair for distal fragment size, moderate for stability, fair for Neer classification, slight for type IIB and III fractures, and moderate for treatment approach. Intrarater agreement was moderate for distal fragment size categories (κ = 0.50, P < .001) and Neer classification (κ = 0.42, P < .001) and substantial for stable fracture (κ = 0.65, P < .001) and decision to operate (κ = 0.65, P < .001). Fracture stability was the best predictor of treatment, with 89% accuracy (P < .001). Fracture stability determination and the decision to operate had the highest interobserver agreement. Fracture stability was the key determinant of treatment, rather than the Neer classification system or the size of the distal fragment. © 2015 The Author(s).

Acute fractures of the pediatric foot and ankle.

PubMed

Halai, Mansur; Jamal, Bilal; Rea, Paul; Qureshi, Mobeen; Pillai, Anand

2015-02-01

Injuries around the foot and ankle are challenging. There is a paucity of literature, outside that of specialist orthopedic journals, that focuses on this subject in the pediatric population. In this review, we outline pediatric foot and ankle fractures in an anatomically oriented manner from the current literature. Our aim is to aid the emergency department doctor to manage these challenging injuries more effectively in the acute setting. These injuries require a detailed history and examination to aid the diagnosis. Often, plain radiographs are sufficient, but more complex injuries require the use of magnetic resonance imaging. Treatment is dependent on the proximity to skeletal maturity and the degree of displacement of fracture. Children have a marked ability to remodel after fractures and therefore mainstay treatment is immobilization by a cast or splint. Operative fixation, although uncommon in this population, may be necessary with adolescents, certain unstable injuries or in cases with displaced articular surface. In the setting of severe foot trauma, skin compromise and compartment syndrome of the foot must be excluded. The integrity of the physis, articular surface and soft tissues are all equally important in treating these injuries.

Fracture Mechanics Analyses of Reinforced Carbon-Carbon Wing-Leading-Edge Panels

NASA Technical Reports Server (NTRS)

Raju, Ivatury S.; Phillips, Dawn R.; Knight, Norman F., Jr.; Song, Kyongchan

2010-01-01

Fracture mechanics analyses of subsurface defects within the joggle regions of the Space Shuttle wing-leading-edge RCC panels are performed. A 2D plane strain idealized joggle finite element model is developed to study the fracture behavior of the panels for three distinct loading conditions - lift-off and ascent, on-orbit, and entry. For lift-off and ascent, an estimated bounding aerodynamic pressure load is used for the analyses, while for on-orbit and entry, thermo-mechanical analyses are performed using the extreme cold and hot temperatures experienced by the panels. In addition, a best estimate for the material stress-free temperature is used in the thermo-mechanical analyses. In the finite element models, the substrate and coating are modeled separately as two distinct materials. Subsurface defects are introduced at the coating-substrate interface and within the substrate. The objective of the fracture mechanics analyses is to evaluate the defect driving forces, which are characterized by the strain energy release rates, and determine if defects can become unstable for each of the loading conditions.

[Unidirectional versus multidirectional palmar locking osteosynthesis of unstable distal radius fractures: comparative analysis with LDR 2.4 mm versus 2.7 mm matrix-Smartlock].

PubMed

Hakimi, M; Jungbluth, P; Gehrmann, S; Nowak, J; Windolf, J; Wild, M

2010-03-01

Due to advances in the development of the unidirectional locking plates there is now an increased use of multidirectional palmar locking plates in the treatment of distal radius factures. The purpose of this study was to evaluate a possible improvement of the treatment and results. This prospective cohort study investigated 40 patients with C1 and C2 Colles' fractures who had been treated with unidirectional and multidirectional locking plates. The average time for the follow-up examinations was 12.3 months (range 12-15 months) after surgery. The intra-operative functional (neutral-zero method), radiological and subjective (DASH score, VAS) results were evaluated. The intra-operative fluoroscopy time of the unidirectional group was 58 s shorter compared to the multidirectional group. All fractures healed without any complication. The radiological, subjective (DASH score) and objective results for both groups were good and showed no differences. Unidirectional palmar locking plates are equally suited for the therapy of C1 and C2 fractures as multidirectional palmar locking plates but multidirectional plates require a longer fluoroscopy time.

Dislocation dynamics modelling of the ductile-brittle-transition

NASA Astrophysics Data System (ADS)

Hennecke, Thomas; Hähner, Peter

2009-07-01

Many materials like silicon, tungsten or ferritic steels show a transition between high temperature ductile fracture with stable crack grow and high deformation energy absorption and low temperature brittle fracture in an unstable and low deformation mode, the ductile-brittle-transition. Especially in steels, the temperature transition is accompanied by a strong increase of the measured fracture toughness over a certain temperature range and strong scatter in the toughness data in this transition regime. The change in fracture modes is affected by dynamic interactions between dislocations and the inhomogeneous stress fields of notches and small cracks. In the present work a dislocation dynamics model for the ductile-brittle-transition is proposed, which takes those interactions into account. The model can explain an increase with temperature of apparent toughness in the quasi-brittle regime and different levels of scatter in the different temperature regimes. Furthermore it can predict changing failure sites in materials with heterogeneous microstructure. Based on the model, the effects of crack tip blunting, stress state, external strain rate and irradiation-induced changes in the plastic flow properties can be discussed.

Unstable cervical spine fracture after penetrating neck injury: a rare entity in an analysis of 1,069 patients.

PubMed

Lustenberger, Thomas; Talving, Peep; Lam, Lydia; Kobayashi, Leslie; Inaba, Kenji; Plurad, David; Branco, Bernardino C; Demetriades, Demetrios

2011-04-01

The value of cervical spine immobilization after penetrating trauma to the neck is the subject of lively debate. The purpose of this study was to review the epidemiology of unstable cervical spine injuries (CSI) after penetrating neck trauma in a large cohort of patients. This is a retrospective analysis of patients admitted with penetrating neck injuries to a Level I trauma center from January 1996 through December 2008. A penetrating neck injury was defined as a gunshot wound (GSW) or stab wound (SW) between the clavicles and the base of the skull. Univariate and multivariate analyses were performed to investigate associations between injury mechanisms, the presence of CSI instability, and mortality. Risk factors independently associated with the presence of a CSI were identified. A total of 1,069 patients met inclusion criteria, of which 463 patients (43.3%) and 606 patients (56.7%) were sustaining GSW and SW, respectively. Overall, 65 patients (6.1%) were diagnosed with a CSI with a significantly higher incidence after GSWs compared with SWs (12.1% vs. 1.5%; p < 0.001). In four patients (0.4%), the CSI was considered unstable, all of them following GSW. All patients with unstable CSI had obvious neurologic deficits or altered mental status at the time of admission. Risk factors independently associated with the presence of a CSI were GSW to the neck and a Glasgow Coma Scale score ≤8 on admission (R = 0.16). The overall incidence of unstable CSI after penetrating trauma to the neck is exceedingly low at 0.4%. Following GSW to the neck, an unstable CSI was noted in <1% of patients. After cervical SW, however, no spinal instability was noted precluding the need for spinal precautions in these instances.

Microbially Induced Calcite Precipitation (MICP) - A Technology for Managing Flow and Transport in Porous and Fractured Media

NASA Astrophysics Data System (ADS)

Phillips, A. J.; Hiebert, R.; Kirksey, J.; Lauchnor, E. G.; Rothman, A.; Spangler, L.; Esposito, R.; Gerlach, R.; Cunningham, A. B.

2014-12-01

Certain microorganisms e.g., Sporosarcina pasteurii contribute enzymes that catalyze reactions which in the presence of calcium, can create saturation conditions favorable for calcium carbonate precipitation (microbially-induced calcium carbonate precipitation (MICP)). MICP can be used for a number of engineering applications including securing geologic storage of CO2 or other fluids by sealing fractures, improving wellbore integrity, and stabilizing fractured and unstable porous media. MICP treatment has the advantage of the use of small microorganisms, ~2μm, suggesting applicability to treatment of small aperture fractures not accessible to traditional treatments, for example the use of fine cement. The promotion of MICP in the subsurface is a complex reactive transport problem coupling microbial, abiotic (geochemical), geomechanical and hydrodynamic processes. In the laboratory, MICP has been demonstrated to cement together heavily fractured shale and reduce the permeability of fractures in shale and sandstone cores up to five orders of magnitude under both ambient and subsurface relevant pressure conditions (Figure 1). Most recently, a MICP fracture treatment field study was performed at a well at the Southern Company Gorgas Steam Generation Plant (Alabama) (Figure 1). The Fayetteville Sandstone at approximately 1120' below ground surface was hydraulically fractured prior to MICP treatment. After 4 days of injection of 24 calcium pulses and 6 microbial inoculations, injectivity of brine into the formation was significantly reduced. The experiment also resulted in a reduction in pressure decay which is a measure of improved wellbore integrity. These promising results suggest the potential for MICP treatment to seal fractured pathways at the field scale to improve the long-term security of geologically-stored carbon dioxide or prevent leakage of shale gas or hydraulic fracturing fluids into functional overlying aquifers, reducing environmental impacts.

SUPRACONDYLAR FRACTURE OF THE HUMERUS IN CHILDREN: FIXATION WITH TWO CROSSED KIRSCHNER WIRES

PubMed Central

Carvalho, Roni Azevedo; Filho, Nelson Franco; Neto, Antonio Batalha Castello; Reis, Giulyano Dias; Dias, Marcos Pereira

2015-01-01

Objective: To analyze and present the surgical results from unstable supracondylar fractures of the humerus in children, treated by means of reduction and percutaneous fixation using two crossed Kirschner wires. Methods: A cross-sectional study was conducted on 20 children, taking into consideration sex, age at the time of the fracture, age at the time of the assessment, side affected, type and mechanism of trauma, postoperative complications and radiographic and clinic variables. Results: Ten fractures were observed in the left arm and ten in the right arm. The age at the time of the fracture ranged from 2 to 13 years (mean: 5.9 ± 2.48 years). Three fractures were classified as type II and 17 as type III. The length of follow-up ranged from four months to three years. Baumann's angle ranged from 69 to 100 (mean: 78.3) and cubitus varus was observed in four patients (values ranging from 84 to 100). According to the modified Flynn's criteria, 20 cases presented satisfactory outcomes: 17 excellent (85%), two good (10%) and one regular (5%). Two patients presented limited range of motion, two had paresthesia in the cubital region and one had transient neuropraxia of the ulnar nerve for six weeks. Conclusion: Percutaneous fixation with two crossed Kirschner wires leads to good results when carried out under direct viewing and with isolation of the ulnar nerve. PMID:27047887

Probabilistic Simulation of Progressive Fracture in Bolted-Joint Composite Laminates

NASA Technical Reports Server (NTRS)

Minnetyan, L.; Singhal, S. N.; Chamis, C. C.

1996-01-01

This report describes computational methods to probabilistically simulate fracture in bolted composite structures. An innovative approach that is independent of stress intensity factors and fracture toughness was used to simulate progressive fracture. The effect of design variable uncertainties on structural damage was also quantified. A fast probability integrator assessed the scatter in the composite structure response before and after damage. Then the sensitivity of the response to design variables was computed. General-purpose methods, which are applicable to bolted joints in all types of structures and in all fracture processes-from damage initiation to unstable propagation and global structure collapse-were used. These methods were demonstrated for a bolted joint of a polymer matrix composite panel under edge loads. The effects of the fabrication process were included in the simulation of damage in the bolted panel. Results showed that the most effective way to reduce end displacement at fracture is to control both the load and the ply thickness. The cumulative probability for longitudinal stress in all plies was most sensitive to the load; in the 0 deg. plies it was very sensitive to ply thickness. The cumulative probability for transverse stress was most sensitive to the matrix coefficient of thermal expansion. In addition, fiber volume ratio and fiber transverse modulus both contributed significantly to the cumulative probability for the transverse stresses in all the plies.

Cement-in-cement stem revision for Vancouver type B periprosthetic femoral fractures after total hip arthroplasty. A 3-year follow-up of 23 cases.

PubMed

Briant-Evans, Toby W; Veeramootoo, Darmaraja; Tsiridis, Eleftherios; Hubble, Matthew J

2009-10-01

Revision surgery for periprosthetic femoral fractures around an unstable cemented femoral stem traditionally requires removal of existing cement. We propose a new technique whereby a well-fixed cement mantle can be retained in cases with simple fractures that can be reduced anatomically when a cemented revision is planned. This technique is well established in femoral stem revision, but not in association with a fracture. We treated 23 Vancouver type B periprosthetic femoral fractures by reducing the fracture and cementing a revision stem into the pre-existing cement mantle, with or without supplementary fixation. 3 patients died in the first 6 months for reasons unrelated to surgery. In addition, 1 was too frail to attend follow-up and was therefore excluded from the study, and 1 patient underwent revision surgery for a nonunion. The remaining 18 cases all healed with radiographic union after an average time of 4.4 (2-11) months. There was no sign of loosening or subsidence of the revision stems within the old cement mantle in any of these cases at the most recent follow-up after an average of 3 (0.3-9) years. Our results support the use of the cement-in-cement revision in anatomically reducible periprosthetic fractures with a well-preserved pre-existing cement mantle. This technique is particularly useful for the elderly patient and for those who are not fit for prolonged surgical procedures.

Surgical Strategy and Techniques for Low-Profile Dorsal Plating in Treating Dorsally Displaced Unstable Distal Radius Fractures

PubMed Central

Hamada, Yoshitaka; Gotani, Hiroyuki; Hibino, Naohito; Tanaka, Yoshitaka; Satoh, Ryousuke; Sasaki, Kousuke; Kanchanathepsak, Thepparat

2016-01-01

Background The low-profile dorsal locking plating (DLP) technique is useful for treating dorsally comminuted intra-articular distal radius fractures; however, due to the complications associated with DLP, the technique is not widely used. Methods A retrospective review of 24 consecutive cases treated with DLP were done. Results All cases were classified into two types by surgical strategy according to the fracture pattern. In type 1, there is a volar fracture line distal to the watershed line in the dorsally displaced fragment, and this type is treated by H-framed DLP. In type 2, the displaced dorsal die-punch fragment is associated with a minimally displaced styloid shearing fracture or a transverse volar fracture line. We found that the die-punch fragment was reduced by the buttress effect of small l-shaped DLP after stabilization of the styloid shearing for the volar segment by cannulated screws from radial styloid processes. At 6 months after surgery, outcomes were good or excellent based on the modified Mayo wrist scores with no serious complications except one case. The mean range of motion of each type was as follows: the palmar flexion was 50, 65 degrees, dorsiflexion was 70, 75 degrees, supination was 85, 85 degrees, and pronation was 80, 80 degrees; in type 1 and 2, respectively. Conclusion DLP is a useful technique for the treatment of selected cases of dorsally displaced, comminuted intra-articular fractures of the distal radius with careful soft tissue coverage. PMID:28428920

Seismic azimuthal anisotropy in crevasse fields

NASA Astrophysics Data System (ADS)

Lindner, F.; Laske, G.; Walter, F.

2017-12-01

Crevasses and englacial fracture networks route meltwater from a glacier's surface to the subglacial drainage system and thus strongly influence glacial hydraulics. However, rapid fracture growth may also lead to sudden (and potentially hazardous) structural failure of unstable glaciers and ice dams, rifting of ice shelves, or iceberg calving.Here, we use passive seismic recordings from Glacier de la Plaine Morte, Switzerland, to investigate the englacial fracture network. Glacier de la Plaine Morte is the largest plateau glacier in the European Alps and extremely vulnerable to climate change. The annual drainage of an ice-marginal lake gives rise to numerous icequakes, thereby demonstrating the interplay between hydraulics and fracturing. The majority of these naturally occurring events exhibits dispersed, high-frequency Rayleigh waves at about 10 Hz and higher. A wide distribution of events allows us to study azimuthal anisotropy of englacial seismic velocities in regions of preferentially oriented fractures.Results from beamforming applied to a 100m-aperture array show strong (up to 9%) azimuthal anisotropy of Rayleigh wave velocities. We find that the fast direction coincides with the observed surface strike of the fractures and that anisotropy is strongest for high-frequency (around 30 Hz) Rayleigh waves that are sensitive only to the uppermost (few tens of meters) part of the glacier. In addition to these results, we propose to study temporal variations in the anisotropy pattern that can potentially be related to growth, shrinkage, and changing water content of the fractures during the course of the lake drainage or other hydrological events.

Cohesive fracture of elastically heterogeneous materials: An integrative modeling and experimental study

NASA Astrophysics Data System (ADS)

Wang, Neng; Xia, Shuman

2017-01-01

A combined modeling and experimental effort is made in this work to examine the cohesive fracture mechanisms of heterogeneous elastic solids. A two-phase laminated composite, which mimics the key microstructural features of many tough engineering and biological materials, is selected as a model material system. Theoretical and finite element analyses with cohesive zone modeling are performed to study the effective fracture resistance of the heterogeneous material associated with unstable crack propagation and arrest. A crack-tip-position controlled algorithm is implemented in the finite element analysis to overcome the inherent instability issues resulting from crack pinning and depinning at local heterogeneities. Systematic parametric studies are carried out to investigate the effects of various material and geometrical parameters, including the modulus mismatch ratio, phase volume fraction, cohesive zone size, and cohesive law shape. Concurrently, a novel stereolithography-based three-dimensional (3D) printing system is developed and used for fabricating heterogeneous test specimens with well-controlled structural and material properties. Fracture testing of the specimens is performed using the tapered double-cantilever beam (TDCB) test method. With optimal material and geometrical parameters, heterogeneous TDCB specimens are shown to exhibit enhanced effective fracture energy and effective fracture toughness than their homogeneous counterparts, which is in good agreement with the modeling predictions. The integrative computational and experimental study presented here provides a fundamental mechanistic understanding of the fracture mechanisms in brittle heterogeneous materials and sheds light on the rational design of tough materials through patterned heterogeneities.

Multilevel non-contiguous spinal injuries: incidence and patterns based on whole spine MRI.

PubMed

Kanna, Rishi Mugesh; Gaike, Chandrasekar V; Mahesh, Anupama; Shetty, Ajoy Prasad; Rajasekaran, S

2016-04-01

Multi-level non-contiguous spinal injuries are not uncommon and their incidence varies from 1.6 to 77% depending on the type of imaging modality used. Delayed diagnosis and missed spinal injuries in non-contiguous spine fractures have been frequently described which can result in significant pain, deformity and neurological deficit. The efficacy of whole spine MRI in detecting asymptomatic significant vertebral fractures is not known. Consecutive spinal injury patients treated between 2011 and 2013 were retrospectively evaluated based on clinical and radiographic records. Patients' demographics, mode of injury, presence of associated injuries, clinical symptoms and the presence of neurological deficit were studied. Radiographs of the fractured region and whole spine MRI were evaluated for the presence of multi-level injuries. Among 484 patients, 95 (19.62%) patients had multilevel injuries including 86 (17.76%) with non-contiguous injuries. Five common patterns of non-contiguous spinal injuries were observed. Pattern I: cervical and thoracic--29.1%, Pattern II: thoracolumbar and lumbosacral--22.1%, Pattern III: thoracic and thoracolumbar--12.8 %, Pattern IV: cervical and thoracolumbar--9.1% and Pattern V: lumbosacral and associated injuries--9.0 %. The incidence of intra-regional non-contiguous injuries was 17.4%. Whole spine MRI scan detected 24 (28.6%) missed secondary injuries of which 5 were unstable. The incidence of multilevel non-contiguous spine injury using whole spine MRI imaging is 17.76%. Five different patterns of multi-level non-contiguous injuries were found with the most common pattern being the cervical and thoracic level injuries. The incidence of unstable injuries can be as high as 21% of missed secondary injuries.

A reliable absorbable intranasal bolster for proper maintenance of fractured nasal bone position.

PubMed

Ducic, Y; Hilger, P A

1999-06-01

The maintenance of comminuted or otherwise unstable nasal bones in proper position following adequate operative reduction, may, on occasion, be a frustrating experience for both the patient and the surgeon. Migration of the fragments may compromise the aesthetic and functional results of well executed corrective nasal surgery. In this article, we will outline our successful, inexpensive approach to this occasionally challenging problem utilising an absorbable intranasal customised Surgicel bolster.

[Rehabilitation after Traumatic Fracture of Thoracic and Lumbar Spine].

PubMed

Bork, Hartmut; Simmel, Stefan; Böhle, Eckhardt; Ernst, Ulrich; Fischer, Klaus; Fromm, Bernd; Glaesener, Jean-Jacques; Greitemann, Bernhard; Krause, P; Panning, S; Pullwitt, V; Schmidt, J; Veihelmann, Andreas; Vogt, Lutz

2018-05-18

On the basis of the S2-k guideline "Rehabilitation after traumatic fractures of the thoracic und lumbar spine without neurologic disorder", this article gives an overview of target-oriented rehabilitation of patients with minor fractures or those with column stability and unstable spinal fractures which are stabilised by surgery. To obtain early social and job related reintegration, outpatient or inpatient rehabilitation has to start immediately after treatment in hospital. Rehabilitation must be orientated towards the biopsychosocial model of ICF and has to be adapted for the patient. The overall goal of rehabilitation is functional restoration of patient health to enable participation in society, life and job. Individual goals may change during rehabilitation, because of differential progress in therapy. Pain management must be orientated towards individual requirements and mental health has to be tested early, especially in polytrauma patients. Disorders have to be treated by psychotherapy, because psychic stress supports chronification of pain. Generally early exercise and physiotherapy are recommended in the guideline, with patient education for health-seeking behavior. Otherwise an orthesis device is not really necessary for treatment of a stable fracture. To improve the outcome of rehabilitation aftercare, treatment has to be arranged during rehabilitation, especially for employed patients. Georg Thieme Verlag KG Stuttgart · New York.

Aortic rupture complicating a fracture of an ankylosed thoracic spine. A case report.

PubMed

Savolaine, E R; Ebraheim, N A; Stitgen, S; Jackson, W T

1991-11-01

A 34-year-old man was injured in a motorcycle accident and suffered both aortic rupture and thoracic spinal fracture, complicated by an underlying undetected ankylosing spondylitis. The latter disease can affect the integrity of vascular and spinal structure. Aortography is recommended as a high priority for the patient in an unstable cardiovascular condition requiring a definitive diagnosis. Aortic rupture and thoracic spine fracture may occur from high energy deceleration trauma. Motor vehicle passenger and pedestrian injuries are most commonly involved, although airline accidents and high falls also generate some cases. Mediastinal widening, displacement of esophagus and trachea, apical dissection of blood, and, especially, paravertebral pleural space widening are common to both injuries. Whereas most mediastinal hematomas are nonaortic in origin, a combined injury must be considered because clinical features may also overlap. These include hypotension (hypovolemic or spinal shock), paraplegia, and severe back pain. In light of the high mortality and time constraints associated with aortic rupture, immediate diagnostic resolution is necessary for appropriate management and priority of investigation.

Pelvic fracture urethral injuries: evaluation of various methods of management.

PubMed

Koraitim, M M

1996-10-01

The results of various immediate treatments of urethral injuries complicating a fractured pelvis were evaluated. The records of 100 male patients with pelvic fracture urethral injury were reviewed, 73 of whom were treated by suprapubic cystostomy and delayed repair, 23 by primary realignment and 4 by primary suturing. Also, the findings of 771 patients reported in the literature were reviewed. Urethral stricture was an almost inevitable consequence (97% of the cases) after suprapubic cystostomy. Primary realignment decreased the incidence of stricture to 53% but produced a 36% impotence rate. Primary suturing also decreased the incidence of stricture to 49% but produced the greatest complication rates for impotence (56%) and incontinence (21%). Suprapubic cystostomy alone is indicated for incomplete urethral rupture, slight urethral distraction and critically unstable patients, and when there are inadequate facilities or inexperienced surgeons. Primary realignment is advised if there is wide separation of the urethral ends, or associated injury of the bladder neck or rectum. Primary suturing is not recommended for any condition.

Paediatric tibial shaft fractures treated by open reduction and stabilization with monolateral external fixation

PubMed Central

Simon, A.-L.; Apostolou, N.; Vidal, C.; Ferrero, E.; Mazda, K.; Ilharreborde, B.

2018-01-01

Abstract Purpose Elastic stable intramedullary nailing is increasingly used for surgical treatment of tibial shaft fractures, but frequently requires immobilization and delayed full weight-bearing. Therefore, external fixation remains interesting. The aim was to report clinico-radiological outcomes of monolateral external fixation for displaced and unstable tibial shaft fractures in children. Methods All tibial fractures consecutively treated by monolateral external fixation between 2008 and 2013 were followed. Inclusion criteria included skeletal immaturity and closed and open Gustilo I fractures caused by a direct impact. Patients were seen until two years postoperatively. Demographics, mechanism of injury, surgical data and complications were recorded. Anteroposterior and lateral side radiographs were performed at each visit. Full-limb 3D reconstructions using biplanar stereroradiography was performed for final limb length and alignment measures. Results A total of 45 patients (mean age 9.7 years ± 0.5) were included. In all, 17 were Gustilo I fractures, with no difference between open and closed fractures for any data. Mean time to full weight bearing was 18.2 days ± 0.7. After 15 days, 39 patients returned to school. Hardware removal (mean time to union 15.6 weeks ± 0.8) was performed during consultation under analgesic gas. There were no cases of nonunion. No fracture healed with > 10° of angulation (mean 5.1° ± 0.4°). Leg-length discrepancy > 10 mm was found for six patients. Conclusions This procedure can be a safe and simple surgical treatment for children with tibial shaft fractures. Few complications and early return to school were reported, with the limitations of non-comparative study. Level of Evidence IV PMID:29456750

The Ankle Injury Management (AIM) trial: a pragmatic, multicentre, equivalence randomised controlled trial and economic evaluation comparing close contact casting with open surgical reduction and internal fixation in the treatment of unstable ankle fractures in patients aged over 60 years.

PubMed

Keene, David J; Mistry, Dipesh; Nam, Julian; Tutton, Elizabeth; Handley, Robert; Morgan, Lesley; Roberts, Emma; Gray, Bridget; Briggs, Andrew; Lall, Ranjit; Chesser, Tim Js; Pallister, Ian; Lamb, Sarah E; Willett, Keith

2016-10-01

Close contact casting (CCC) may offer an alternative to open reduction and internal fixation (ORIF) surgery for unstable ankle fractures in older adults. We aimed to (1) determine if CCC for unstable ankle fractures in adults aged over 60 years resulted in equivalent clinical outcome compared with ORIF, (2) estimate cost-effectiveness to the NHS and society and (3) explore participant experiences. A pragmatic, multicentre, equivalence randomised controlled trial incorporating health economic evaluation and qualitative study. Trauma and orthopaedic departments of 24 NHS hospitals. Adults aged over 60 years with unstable ankle fracture. Those with serious limb or concomitant disease or substantial cognitive impairment were excluded. CCC was conducted under anaesthetic in theatre by surgeons who attended training. ORIF was as per local practice. Participants were randomised in 1 : 1 allocation via remote telephone randomisation. Sequence generation was by random block size, with stratification by centre and fracture pattern. Follow-up was conducted at 6 weeks and, by blinded outcome assessors, at 6 months after randomisation. The primary outcome was the Olerud-Molander Ankle Score (OMAS), a patient-reported assessment of ankle function, at 6 months. Secondary outcomes were quality of life (as measured by the European Quality of Life 5-Dimensions, Short Form questionnaire-12 items), pain, ankle range of motion and mobility (as measured by the timed up and go test), patient satisfaction and radiological measures. In accordance with equivalence trial US Food and Drug Administration guidance, primary analysis was per protocol. We recruited 620 participants, 95 from the pilot and 525 from the multicentre phase, between June 2010 and November 2013. The majority of participants, 579 out of 620 (93%), received the allocated treatment; 52 out of 275 (19%) who received CCC later converted to ORIF because of loss of fracture reduction. CCC resulted in equivalent ankle function compared with ORIF at 6 months {OMAS 64.5 points [standard deviation (SD) 22.4 points] vs. OMAS 66.0 points (SD 21.1 points); mean difference -0.65 points, 95% confidence interval (CI) -3.98 to 2.68 points; standardised effect size -0.04, 95% CI -0.23 to 0.15}. There were no differences in quality of life, ankle motion, pain, mobility and patient satisfaction. Infection and/or wound problems were more common with ORIF [29/298 (10%) vs. 4/275 (1%)], as were additional operating theatre procedures [17/298 (6%) vs. 3/275 (1%)]. Malunion was more common with CCC [38/249 (15%) vs. 8/274 (3%); p  < 0.001]. Malleolar non-union was lower in the ORIF group [lateral: 0/274 (0%) vs. 8/248 (3%); p  = 0.002; medial: 3/274 (1%) vs. 18/248 (7%); p  < 0.001]. During the trial, CCC showed modest mean cost savings [NHS mean difference -£644 (95% CI -£1390 to £76); society mean difference -£683 (95% CI -£1851 to £536)]. Estimates showed some imprecision. Incremental quality-adjusted life-years following CCC were no different from ORIF. Over common willingness-to-pay thresholds, the probability that CCC was cost-effective was very high (> 95% from NHS perspective and 85% from societal perspective). Experiences of treatments were similar; both groups endured the impact of fracture, uncertainty regarding future function and the need for further interventions. Assessors at 6 weeks were necessarily not blinded. The learning-effect analysis was inconclusive because of limited CCC applications per surgeon. CCC provides a clinically equivalent outcome to ORIF at reduced cost to the NHS and to society at 6 months. Longer-term follow-up of trial participants is under way to address concerns over potential later complications or additional procedures and their potential to impact on ankle function. Further study of the patient factors, radiological fracture patterns and outcomes, treatment responses and prognosis would also contribute to understanding the treatment pathway. Current Controlled Trials ISRCTN04180738. The National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment ; Vol. 20, No. 75. See the NIHR Journals Library website for further project information. This report was developed in association with the National Institute for Health Research Oxford Biomedical Research Unit funding scheme. The pilot phase was funded by the AO Research Foundation.

Is there any place for the variable angle proximal femoral plate? A case matched cohort study against the Dynamic Hip Screw system.

PubMed

Tucker, A; Diamond, O; McDonald, S; Johnston, A; Neil, M; Kealey, D; Archbold, P

2016-10-01

The Variable angle Martin Plate (MP) is designed to offer patient-specific adaption for the treatment of intertrochanteric hip fractures. Its proposed benefits include optimization of lag screw placement, plate shaft congruence and reduced risk of failure. Often its use has been criticized as representing a poor reduction of the fracture. The purpose of this study was to assess for a poorer quality of reduction, and compare functional outcomes and mortality, using a MP to that of a fixed angle Dynamic Hip Screw (DHS) in a matched cohort of patients. A retrospective review of a prospective fracture database system was undertaken between 1st January 2004 to 31st December 2013. MP patients were matched to a cohort of DHS patients. Outcomes measure were a quality of procedure score(QPS), 1-year mortality rates, reoperation rates, and Barthel Index functional outcome. Minimum follow up was 12 months. A total of 77 Martin Plate patients were identified and case matched. The mean pre- and post-op Neck Shaft Angle (NSA) in the MPs was significantly different (132.97±7.78 Vs 126±8.62; p<0.0001). Conversely, the mean pre op DHS NSA and the mean post op NSA was not (p=0.397). Mean Tip-Apex Distance (TAD) was significantly different between groups; MP mean 26.51±9.09mm vs DHS 23.50±8.14mm (p=0.023). The QPS consisted of 4 variables. A significant inverse relationship between QPS and the incidence of construct related complications exists. TAD>25mm, and a change in AP NSA of >5°conveyed the greatest risk of complications. No difference occurred in complications, nor 12-month mortality. No statistical difference was found in the quality of reduction between MP and DHS in this group of matched patients. QPS demonstrated a significant inverse correlation with implant-related complications. No significant difference was noted in the incidence of complications, Barthel Index functional scores, or 12-month mortality between implants. A rationale exists regarding the use of MPs, particularly in patients with varus NSA. However, planning and adequate reduction are essential regardless of implant choice. Copyright © 2016 Elsevier Ltd. All rights reserved.

EFFECTS OF MINERAL CONTENT ON THE FRACTURE PROPERTIES OF EQUINE CORTICAL BONE IN DOUBLE-NOTCHED BEAMS

PubMed Central

McCormack, Jordan; Stover, Susan M.; Gibeling, Jeffery C.; Fyhrie, David P.

2012-01-01

We recently developed a method to measure cortical bone fracture initiation toughness using a double-notched beam in four-point bending. This method was used to test the hypothesis that mineralization around the two notch roots is correlated with fracture toughness and crack extension (physical damage). Total energy absorbed to failure negatively correlated with average mineralization of the beam (r2=0.62), but not with notch root mineralization. Fracture initiation toughness was positively correlated to mineralization at the broken notch root (r2=0.34). Crack length extension at the unbroken notch was strongly negatively correlated with the average mineralization of the notch roots (r2=0.81) whereas crack length extension at the broken notch did not correlate with any of the mineralization measurements. Mineralization at the notch roots and the average mineralization contributed independently to the mechanical and damage properties. The data are consistent with an hypothesis that a) high notch root mineralization results in less stable crack length extension but high force to initiate unstable crack propagation while b) higher average mineralization leads to low post-yield (and total) energy absorption to failure. PMID:22394589

Review of Van earthquakes form an orthopaedic perspective: a multicentre retrospective study.

PubMed

Guner, Savas; Guner, Sukriye Ilkay; Isik, Yasemin; Gormeli, Gokay; Kalender, Ali Murat; Turktas, Ugur; Gokalp, Mehmet Ata; Gozen, Abdurrahim; Isik, Mustafa; Ozkan, Sezai; Turkozu, Tulin; Karadas, Sevdegul; Ceylan, Mehmet Fethi; Ediz, Levent; Bulut, Mehmet; Gunes, Yusuf; Gormeli, Ayse; Erturk, Cemil; Eseoglu, Metehan; Dursun, Recep

2013-01-01

This is a descriptive analysis, of victims of Turkey's October 23, 2011 and November 21, 2011 Van earthquakes. The goal of this study is investigated the injury profile of the both earthquakes in relation to musculoskeletal trauma. We retrospectively reviewed medical records of 3,965 patients admitted to in seven hospitals. A large share of these injuries were soft tissue injuries, followed by fractures, crush injuries, crush syndromes, nerve injuries, vascular injuries, compartment syndrome and joint dislocations. A total of 73 crush injuries were diagnosed and 31 of them were developed compartment syndrome. The patients with closed undisplaced fractures were treated with casting braces. For closed unstable fractures with good skin and soft-tissue conditions, open reduction and internal fixation was performed. All patients with open fracture had an external fixator applied after adequate debridement. Thirty one of 40 patients with compartment syndrome were treated by fasciotomy. For twelve of them, amputation was necessary. The most common procedure performed was debridement, followed by open reduction and internal fixation and closed reduction-casting, respectively. The results of this study may provide the basis for future development of strategy to optimise attempts at rescue and plan treatment of survivors with musculoskeletal injuries after earthquakes.

Gunshot wounds: epidemiology, wound ballistics, and soft-tissue treatment.

PubMed

Dougherty, Paul J; Najibi, Soheil; Silverton, Craig; Vaidya, Rahul

2009-01-01

The extremities are the most common anatomic location for gunshot wounds. Because of the prevalence of gunshot injuries, it is important that orthopaedic surgeons are knowledgeable about caring for them. The most common injuries seen with gunshot wounds are those of the soft tissues. Nonsurgical management of patients who have gunshot wounds with minimal soft-tissue disruption has been successfully accomplished in emergency departments for several years; this includes extremity wounds without nerve, intra-articular, or vascular injury. Stable, nonarticular fractures of an extremity have also been successfully treated with either minimal surgical or nonsurgical methods in the emergency department. Indications for surgical treatment include unstable fractures, intra-articular injuries, a significant soft-tissue injury (especially with skin loss), vascular injury, and/or a large or expanding hematoma.

Geochemical alteration vs mechanical weathering on stability of unstable slope : Case of the deep seated landslide of Séchilienne (Isère, France)

NASA Astrophysics Data System (ADS)

Bertrand, Catherine; Nevers, Pierre; Gaillardet, Jérôme; Dubois, Laurent

2017-04-01

The Séchilienne landslide is located on the right bank of the Romanche River, South East of Grenoble (Isère, France). The active zone of the gravitational instability involves several millions of cubic meters. The geology consists of fractured hard rocks (micaschists) with double permeability and strong spatial heterogeneities. The permeability of the basement areas is rather obtained by long term weathering, which can be associated with a mechanical action in high relief mountainous regions. Water plays two major roles, the first one being a hydrogeological process, which is a factor that worsens instability, and the second one being a geochemical factor that alters the massif, making it less cohesive. These two factors interact through time and modify permeability and therefore the flow of water within the rock. Hydrochemistry simultaneously provides information about water flows (location and amount of refill, types and flow patterns, storage, residence time), and also about the acquisition of the chemistry during its transit through the aquifer (water-rock interaction during the transit, quantification of the alteration). The issue is to improve the knowledge of the genesis of the chemical signal, and to define the contributions of the knowledge of this signal in terms of functioning, on the pressure transferring as well as on the mass transferring and its effects. Hydrogeochemistry, which is integrative of the entire "history" of the water in the different compartments, paired with geochemical modelling, which allow the discrimination of the chemical signal according to its path in the aquifer, turns out to be an appropriate method for the objective. These tools (hydrogeochemistry & geochemical modelling) are designed to understand the complex relationship between chemical weathering, hydromechanical changes and weakening / deformation of the unstable rock slope The deformation of the unstable slope is monitored by on-site extensometric gauges, inclinometers, GNSS and at distance by a terrestrial radar and a total station. A hydrogeochemical monitoring of the non-saturated zone in a fractured hard rock is established since 2010 on the site. This monitoring leaded by the French Landslide Observatory (OMIV) consists of continuous measurements of physical parameters (Temp. EC. Flow rate) on two groundwater outlets and weekly samplings of the waters for quality monitoring Hydrochemical studies allows a sufficient resolution to detect exchange between compartments of contrasted permeability within fractured aquifers. They enabled to determine the influence of the hydrodynamic conditions variations at the aquifer scale, on exchange modalities between the pervious zone and the less pervious zone, and to highlight that permeability variations on mechanical stress effect may induce variations of the chemical signal of a fractured aquifer. Geochemical alteration represents a significant contribution compared to mechanical weathering on the long term (multiannual evolution by mechanical and geochemical damage of the fractures and the rock matrix), to the medium and short-term (seasonal and instantaneous effect of hydro-mechanical fluctuations located in the fractures of the slope) evolution of the rock slope failures. The reconstitution of the chemical evolutions of water and minerals during the transit of water through the rock, might allow establishing local erosion balance In addition it might also allow to locate and to quantify at the scale of a rock slope, the chemical erosion able to induce "chemical tiredness" of the rock.

Is arthroplasty preferable to internal fixation for the treatment of extracapsular fracture of the upper femur in the elderly?

PubMed

Duriez, P; Devaux, T; Chantelot, C; Baudrier, N; Hery, J-Y; Mainard, D; Favier, T; Massin, P

2016-10-01

Although internal fixation is the reference treatment for extracapsular fracture of the upper femur, indications for arthroplasty are broadening, especially in unstable comminutive fracture in fragile bone. The present study hypothesis was that arthroplasty reduces early mortality and morbidity and provides better recovery of autonomy in over-80 year-old patients than does internal fixation. A prospective multicenter study was conducted on 8 sites. Internal fixation was systematically used in 5 centers; arthroplasty was used systematically in 1 center, and reserved for unstable fracture in 2 centers. A total of 697 patients aged over 80 years (mean age, 85±5 years), presenting with extracapsular fracture, were included; 521 were treated by internal fixation and 176 by arthroplasty. Results were studied on multivariate analysis of ASA score, blood loss, transfusion, and also of treatment modality as an independent factor for early (first 6 months) mortality and morbidity (mechanical, general and nutritional complications) and functional outcome (autonomy and dependence). Overall mortality was 19.2%. Autonomy deteriorated in 56% of patients alive at 6 months and dependence worsened in 44%. Two percent of those managed by internal fixation underwent revision for disassembly (n=8) or infection (n=1). Eight percent of those managed by arthroplasty underwent revision for dislocation (n=4), implant loosening (n=3) or infection (n=7). On univariate analysis, mortality was higher in the arthroplasty group (25%) than with internal fixation (17%; P=0.002), as were blood loss (425±286mL versus 333±223mL; P<0.0001), transfusion rate (61% versus 32%; P<0.0001) and infection (4% versus 0.2%; P<0.001). On multivariate analysis, however, treatment modality no longer showed impact on mortality or on morbidity and autonomy at 6 months. Nutritional status was better conserved at 6 months following arthroplasty, but dependence worsened. Poor preoperative autonomy, ASA score, and nutritional status and time to treatment were independent factors for mortality. Transfusion, associated with onset of mechanical complications, significantly increased dependence. Type of treatment had little impact on mortality, morbidity or functional outcome. Differences seemed more related to preoperative functional and nutritional status. III, prospective case-control study. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A comparison between rib fracture patterns in peri- and post-mortem compressive injury in a piglet model.

PubMed

Bradley, Amanda L; Swain, Michael V; Neil Waddell, J; Das, Raj; Athens, Josie; Kieser, Jules A

2014-05-01

Forensic biomechanics is increasingly being used to explain how observed injuries occur. We studied infant rib fractures from a biomechanical and morphological perspective using a porcine model. We used 24, 6th ribs of one day old domestic pigs Sus scrofa, divided into three groups, desiccated (representing post-mortem trauma), fresh ribs with intact periosteum (representing peri-mortem trauma) and those stored at -20°C. Two experiments were designed to study their biomechanical behaviour fracture morphology: ribs were axially compressed and subjected to four-point bending in an Instron 3339 fitted with custom jigs. Morphoscopic analysis of resultant fractures consisted of standard optical methods, micro-CT (μCT) and Scanning Electron Microscopy (SEM). During axial compression fresh ribs did not fracture because of energy absorption capabilities of their soft and fluidic components. In flexure tests, dry ribs showed typical elastic-brittle behaviour with long linear load-extension curves, followed by short non-linear elastic (hyperelastic) behaviour and brittle fracture. Fresh ribs showed initial linear-elastic behaviour, followed by strain softening and visco-plastic responses. During the course of loading, dry bone showed minimal observable damage prior to the onset of unstable fracture. Frozen then thawed bone showed similar patterns to fresh bone. Morphologically, fresh ribs showed extensive periosteal damage to the tensile surface with areas of collagen fibre pull-out along the tensile surface. While all dry ribs fractured precipitously, with associated fibre pull-out, the latter feature was absent in thawed ribs. Our study highlights the fact that under controlled loading, fresh piglet ribs (representing perimortem trauma) did not fracture through bone, but was associated with periosteal tearing. These results suggest firstly, that complete lateral rib fracture in infants may in fact not result from pure compression as has been previously assumed; and secondly, that freezing of bone during storage may affect its fracture behaviour. Copyright © 2013 Elsevier Ltd. All rights reserved.

Safe corridors for K-wiring in phalangeal fractures.

PubMed

Rex, C; Vignesh, R; Javed, M; Balaji, Subba Chandra; Premanand, C; Zakki, Syed Ashfaque

2015-01-01

Unstable phalangeal fractures are commonly treated with K-wire fixation. Operative fixation must be used judiciously and with the expectation that the ultimate outcome should be better than the outcome after nonoperative management. It is necessary to achieve a stable fracture fixation and early mobilization. In order to achieve this goal, one should closely understand the safe portals/corridors in hand for K-wire entry for fractures of the phalanges. Safe corridors were defined and tested using a pilot cadaveric and a clinical case study by assessing the outcome. In our prospective case series, 50 patients with 64 phalangeal fractures were treated with closed reduction and K-wires were inserted through safe portals identified by a pilot cadaveric study. On table active finger movement test was done and the results were analyed using radiology, disabilities of the arm, shoulder, and hand (DASH) score and total active motion (TAM). In our study, little finger (n = 28) was the most commonly involved digit. In fracture pattern, transverse (n = 20) and spiral (n = 20) types were common. Proximal phalanx (n = 38) was commonly involved and the common site being the base of the phalanx (n = 28). 47 (95%) patients had excellent TAM and the mean postoperative DASH score was 58.05. All patients achieved excellent and good scores proving the importance of the safe corridor concept. K-wiring through the safe corridor has proved to yield the best clinical results because of least tethering of soft tissues as evidenced by performing "on-table active finger movement test" at the time of surgery. We strongly recommend K-wiring through safe portals in all phalangeal fractures.

Distal radius fractures and the volar lunate facet fragment: Kirschner wire fixation in addition to volar-locked plating.

PubMed

Moore, Amy M; Dennison, David G

2014-06-01

The volar lunate facet fragment of a distal radius fracture may not be stabilized with volar-locked plating alone due to the small size and distal location of the fragment. Identification and stabilization of this small fragment is critical as unstable fixation may result in radiocarpal and radioulnar joint subluxation. The addition of spring wire fixation with volar plating can provide stable internal fixation of this critical fracture fragment. A retrospective review (2006-2011) identified nine patients with distal radius fractures with an associated volar lunate facet fragment that were treated with volar-locked plating and spring wire fixation of the volar lunate facet fragment. Radiographic indices, range of motion, grip strength, and postoperative Patient-related wrist evaluation (PRWE) scores were obtained to assess pain and function. All distal radius fractures healed, and the volar lunate facet fragment reduction was maintained. The mean follow-up was 54 weeks. Mean active range of motion was 46° wrist flexion, 51° wrist extension, 80° pronation, and 68° supination. The mean grip strength was 21 Kg, achieving 66 % of the uninjured limb. The average PRWE score was 17. No patient required removal of hardware or had evidence of tendon irritation. The addition of spring wire fixation to volar-locked plating provided stable fixation of the volar lunate facet fragment of distal radius fractures without complication. This technique addresses a limitation of volar-locked plating to control the small volar lunate facet fragment in distal radius fractures otherwise amenable to volar plating. A retrospective case series, Level IV.

Trochanteric fracture-implant motion during healing - A radiostereometry (RSA) study.

PubMed

Bojan, Alicja J; Jönsson, Anders; Granhed, Hans; Ekholm, Carl; Kärrholm, Johan

2018-03-01

Cut-out complication remains a major unsolved problem in the treatment of trochanteric hip fractures. A better understanding of the three-dimensional fracture-implant motions is needed to enable further development of clinical strategies and countermeasures. The aim of this clinical study was to characterise and quantify three-dimensional motions between the implant and the bone and between the lag screw and nail of the Gamma nail. Radiostereometry Analysis (RSA) analysis was applied in 20 patients with trochanteric hip fractures treated with an intramedullary nail. The following three-dimensional motions were measured postoperatively, at 1 week, 3, 6 and 12 months: translations of the tip of the lag screw in the femoral head, motions of the lag screw in the nail, femoral head motions relative to the nail and nail movements in the femoral shaft. Cranial migration of the tip of the lag screw dominated over the other two translation components in the femoral head. In all fractures the lag screw slid laterally in the nail and the femoral head moved both laterally and inferiorly towards the nail. All femoral heads translated posteriorly relative to the nail, and rotations occurred in both directions with median values close to zero. The nail tended to retrovert in the femoral shaft. Adverse fracture-implant motions were detected in stable trochanteric hip fractures treated with intramedullary nails with high resolution. Therefore, RSA method can be used to evaluate new implant designs and clinical strategies, which aim to reduce cut-out complications. Future RSA studies should aim at more unstable fractures as these are more likely to fail with cut-out. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparing Different Surgical Techniques for Addressing the Posterior Malleolus in Supination External Rotation Ankle Fractures and the Need for Syndesmotic Screw Fixation.

PubMed

Li, Mengnai; Collier, Rachel C; Hill, Brian W; Slinkard, Nathaniel; Ly, Thuan V

Trimalleolar ankle fractures are unstable injuries with possible syndesmotic disruption. Recent data have described inherent morbidity associated with screw fixation of the syndesmosis, including the potential for malreduction, hardware irritation, and post-traumatic arthritis. The posterior malleolus is an important soft tissue attachment for the posterior inferior syndesmosis ligament. We hypothesized that fixation of a sizable posterior malleolar (PM) fracture in supination external rotation type IV (SER IV) ankle fractures would act to stabilize the syndesmosis and minimize or eliminate the need for trans-syndesmotic fixation. A retrospective review of trimalleolar ankle fractures surgically treated from October 2006 to April of 2011 was performed. A total of 143 trimalleolar ankle fractures were identified, and 97 were classified as SER IV. Of the 97 patients, 74 (76.3%) had a sizable PM fragment. Syndesmotic fixation was required in 7 of 34 (20%) and 27 of 40 (68%), respectively, when the PM was fixed versus not fixed (p = .0002). When the PM was indirectly reduced using an anterior to posterior screw, 7 of 15 patients (46.7%) required syndesmotic fixation compared with none of 19 patients when the PM fragment was fixated with direct posterior lateral plate fixation (p = .0012). Fixation of the PM fracture in SER IV ankle fractures can restore syndesmotic stability and, thus, lower the rate of syndesmotic fixation. We found that fixation of a sizable PM fragment in SER IV or equivalent injuries through posterolateral plating can eliminate the need for syndesmotic screw fixation. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Effects of electric field on the fracture toughness (KIc) of ceramic PZT

NASA Astrophysics Data System (ADS)

Goljahi, Sam; Lynch, Christopher S.

2013-09-01

This work was motivated by the observation that a small percentage of the ceramic lead zirconate titanate (PZT) parts in a device application, one that requires an electrode pattern on the PZT surface, developed fatigue cracks at the edges of the electrodes; yet all of the parts were subjected to similar loading. To obtain additional information on the fracture behavior of this material, similar specimens were run at higher voltage in the laboratory under a microscope to observe the initiation and growth of the fatigue cracks. A sequence of experiments was next performed to determine whether there were fracture toughness variations that depended on material processing. Plates were cut from a single bar in different locations and the Vickers indentation technique was used to measure the relative fracture toughness as a function of position along the bar. Small variations in toughness were found, that may account for some of the devices developing fatigue cracks and not others. Fracture toughness was measured next as a function of electric field. The surface crack in flexure technique was modified to apply an electric field perpendicular to a crack. The results indicate that the fracture toughness drops under a positive electric field and increases under a negative electric field that is less than the coercive field, but as the negative coercive field is approached the fracture toughness drops. Examination of the fracture surfaces using an optical microscope and a surface profilometer reveal the initial indentation crack shape and (although less accurately) the crack shape and size at the transition from stable to unstable growth. These results are discussed in terms of a ferroelastic toughening mechanism that is dependent on electric field.

A two-stage model of fracture of rocks

USGS Publications Warehouse

Kuksenko, V.; Tomilin, N.; Damaskinskaya, E.; Lockner, D.

1996-01-01

In this paper we propose a two-stage model of rock fracture. In the first stage, cracks or local regions of failure are uncorrelated occur randomly throughout the rock in response to loading of pre-existing flaws. As damage accumulates in the rock, there is a gradual increase in the probability that large clusters of closely spaced cracks or local failure sites will develop. Based on statistical arguments, a critical density of damage will occur where clusters of flaws become large enough to lead to larger-scale failure of the rock (stage two). While crack interaction and cooperative failure is expected to occur within clusters of closely spaced cracks, the initial development of clusters is predicted based on the random variation in pre-existing Saw populations. Thus the onset of the unstable second stage in the model can be computed from the generation of random, uncorrelated damage. The proposed model incorporates notions of the kinetic (and therefore time-dependent) nature of the strength of solids as well as the discrete hierarchic structure of rocks and the flaw populations that lead to damage accumulation. The advantage offered by this model is that its salient features are valid for fracture processes occurring over a wide range of scales including earthquake processes. A notion of the rank of fracture (fracture size) is introduced, and criteria are presented for both fracture nucleation and the transition of the failure process from one scale to another.

Spinopelvic dissociation: multidetector computed tomographic evaluation of fracture patterns and associated injuries at a single level 1 trauma center.

PubMed

Gupta, Pushpender; Barnwell, Jonathan C; Lenchik, Leon; Wuertzer, Scott D; Miller, Anna N

2016-06-01

The objective of the present study is to evaluate multidetector computed tomographic (MDCT) fracture patterns and associated injuries in patients with spinopelvic dissociation (SPD). Our institutional trauma registry database was reviewed from Jan. 1, 2006, to Sept. 30, 2012, specifically evaluating patients with sacral fractures. MDCT scans of patients with sacral fractures were reviewed to determine the presence of SPD. SPD cases were characterized into the following fracture patterns: U-shaped, Y-shaped, T-shaped, H-shaped, and burst. The following MDCT features were recorded: level of the horizontal fracture, location of vertical fracture, kyphosis between major fracture fragments, displacement of fracture fragment, narrowing of central spinal canal, narrowing of neural foramina, and extension into sacroiliac joints. Quantitative evaluation of the sacral fractures was performed in accordance with the consensus statement by the Spine Trauma Study Group. Medical records were reviewed to determine associated pelvic and non-pelvic fractures, bladder and bowel injuries, nerve injuries, and type of surgical intervention. Twenty-one patients had SPD, of whom 13 were men and eight were women. Mean age was 41.8 years (range 18.8 to 87.7). Five fractures (24 %) were U-shaped, six (29 %) H-shaped, four (19 %) Y-shaped, and six (29 %) burst. Nine patients (43 %) had central canal narrowing, and 19 (90 %) had neural foramina narrowing. Eleven patients (52 %) had kyphotic angulation between major fracture fragments, and seven patients (33 %) had either anterior (24 %) or posterior (10 %) displacement of the proximal fracture fragment. Fourteen patients (67 %) had associated pelvic fractures, and 20 (95 %) had associated non-pelvic fractures. Two patients (10 %) had associated urethral injuries, and one (5 %) had an associated colon injury. Seven patients (33 %) had associated nerve injuries. Six patients (29 %) had surgical fixation while 15 (71 %) were managed non-operatively. On trauma MDCT examinations, patients with SPD have characteristic fracture patterns. It is important to differentiate SPD from other pelvic ring injuries due to high rate of associated injuries. Although all SPD injuries are unstable and need fixation, the decision for operative management in an individual patient depends on the systemic injury pattern, specific fracture pattern, and the ability to attain stable screw fixation.

Monitoring Unstable Glaciers with Seismic Noise Interferometry

NASA Astrophysics Data System (ADS)

Preiswerk, L. E.; Walter, F.

2016-12-01

Gravity-driven glacier instabilities are a threat to human infrastructure in alpine terrain, and this hazard is likely to increase with future changes in climate. Seismometers have been used previously on hazardous glaciers to monitor the natural englacial seismicity. In some situations, an increase in "icequake" activity may indicate fracture growth and thus an imminent major break-off. However, without independent constraints on unstable volumes, such mere event counting is of little use. A promising new approach to monitor unstable masses in Alpine terrain is coda wave interferometry of ambient noise. While already established in the solid earth, application to glaciers is not straightforward, because the lack of inhomogeneities typically suppresses seismic coda waves in glacier ice. Only glaciers with pervasive crevasses provide enough scattering to generate long codas. This is requirement is likely met for highly dynamic unstable glaciers. Here, we report preliminary results from a temporary 5-station on-ice array of seismometers (corner frequencies: 1 Hz, array aperture: 500m) on Bisgletscher (Switzerland). The seismometers were deployed in shallow boreholes, directly above the unstable tongue of the glacier. In the frequency band 4-12 Hz, we find stable noise cross-correlations, which in principle allows monitoring on a subdaily scale. The origin and the source processes of the ambient noise in these frequencies are however uncertain. As a first step, we evaluate the stability of the sources in order to separate effects of changing source parameters from changes of englacial properties. Since icequakes occurring every few seconds may dominate the noise field, we compare their temporal and spatial occurrences with the cross-correlation functions (stability over time, the asymmetry between causal and acausal parts of the cross-correlation functions) as well as with results from beamforming to assess the influence of these transient events on the noise field.

Fresh-Stored Osteochondral Allograft for Treatment of Osteochondritis Dissecans the Femoral Head

DTIC Science & Technology

2010-01-01

rotational osteotomy for treatment of avascular necrosis of the femoral head. Arch Orthop Trauma Surg. 1996;115:80–84. Volume 468, Number 2, February 2010...14. Hall FM. Osteochondrosis dissecans and avascular necrosis of bone. (Comment on: Skeletal Radiol. 1990;19(6):419–421.) Skeletal Radiol. 1991;20...439–456. 28. Schneider W, Aigner N, Pinggera O, Knahr K. Intertrochanteric osteotomy for avascular necrosis of the head of the femur: sur- vival

Experimentally induced cam impingement in the sheep hip.

PubMed

Siebenrock, Klaus A; Fiechter, Ruth; Tannast, Moritz; Mamisch, Tallal C; von Rechenberg, Brigitte

2013-04-01

Sheep hips have a natural non-spherical femoral head similar to a cam-type deformity in human beings. By performing an intertrochanteric varus osteotomy, cam-type femoro-acetabular impingement (FAI) during flexion can be created. We tested the hypotheses that macroscopic lesions of the articular cartilage and an increased Mankin score (MS) can be reproduced by an experimentally induced cam-type FAI in this ovine in vivo model. Furthermore, we hypothesized that the MS increases with longer ambulatory periods. Sixteen sheep underwent unilateral intertrochanteric varus osteotomy of the hip with the non-operated hip as a control. Four sheep were sacrificed after 14, 22, 30, and 38-weeks postoperatively. We evaluated macroscopic chondrolabral alterations, and recorded the MS, based on histochemical staining, for each ambulatory period. A significantly higher prevalence of macroscopic chondrolabral lesions was found in the impingement zone of the operated hips. The MS was significantly higher in the acetabular/femoral cartilage of the operated hips. Furthermore, these scores increased as the length of the ambulatory period increased. Cam-type FAI can be induced in an ovine in vivo model. Localized chondrolabral degeneration of the hip, similar to that seen in humans (Tannast et al., Clin Orthop Relat Res 2008; 466: 273-280; Beck et al., J Bone Joint Surg Br 2005; 87: 1012-1018), can be reproduced. This experimental sheep model can be used to study cam-type FAI. Copyright © 2012 Orthopaedic Research Society.

Medial malleolar fractures: a biomechanical study of fixation techniques.

PubMed

Fowler, T Ty; Pugh, Kevin J; Litsky, Alan S; Taylor, Benjamin C; French, Bruce G

2011-08-08

Fracture fixation of the medial malleolus in rotationally unstable ankle fractures typically results in healing with current fixation methods. However, when failure occurs, pullout of the screws from tension, compression, and rotational forces is predictable. We sought to biomechanically test a relatively new technique of bicortical screw fixation for medial malleoli fractures. Also, the AO group recommends tension-band fixation of small avulsion type fractures of the medial malleolus that are unacceptable for screw fixation. A well-documented complication of this technique is prominent symptomatic implants and secondary surgery for implant removal. Replacing stainless steel 18-gauge wire with FiberWire suture could theoretically decrease symptomatic implants. Therefore, a second goal was to biomechanically compare these 2 tension-band constructs. Using a tibial Sawbones model, 2 bicortical screws were compared with 2 unicortical cancellous screws on a servohydraulic test frame in offset axial, transverse, and tension loading. Second, tension-band fixation using stainless steel wire was compared with FiberWire under tensile loads. Bicortical screw fixation was statistically the stiffest construct under tension loading conditions compared to unicortical screw fixation and tension-band techniques with FiberWire or stainless steel wire. In fact, unicortical screw fixation had only 10% of the stiffness as demonstrated in the bicortical technique. In a direct comparison, tension-band fixation using stainless steel wire was statistically stiffer than the FiberWire construct. Copyright 2011, SLACK Incorporated.

Comparison of two-transsacral-screw fixation versus triangular osteosynthesis for transforaminal sacral fractures.

PubMed

Min, Kyong S; Zamorano, David P; Wahba, George M; Garcia, Ivan; Bhatia, Nitin; Lee, Thay Q

2014-09-01

Transforaminal pelvic fractures are high-energy injuries that are translationally and rotationally unstable. This study compared the biomechanical stability of triangular osteosynthesis vs 2-transsacral-screw fixation in the repair of a transforaminal pelvic fracture model. A transforaminal fracture model was created in 10 cadaveric lumbopelvic specimens. Five of the specimens were stabilized with triangular osteosynthesis, which consisted of unilateral L5-to-ilium lumbopelvic fixation and ipsilateral iliosacral screw fixation. The remaining 5 were stabilized with a 2-transsacral-screw fixation technique that consisted of 2 transsacral screws inserted across S1. All specimens were loaded cyclically and then loaded to failure. Translation and rotation were measured using the MicroScribe 3D digitizing system (Revware Inc, Raleigh, North Carolina). The 2-transsacral-screw group showed significantly greater stiffness than the triangular osteosynthesis group (2-transsacral-screw group, 248.7 N/mm [standard deviation, 73.9]; triangular osteosynthesis group, 125.0 N/mm [standard deviation, 66.9]; P=.02); however, ultimate load and rotational stiffness were not statistically significant. Compared with triangular osteosynthesis fixation, the use of 2 transsacral screws provides a comparable biomechanical stability profile in both translation and rotation. This newly revised 2-transsacral-screw construct offers the traumatologist an alternative method of repair for vertical shear fractures that provides biplanar stability. It also offers the advantage of percutaneous placement in either the prone or supine position. Copyright 2014, SLACK Incorporated.

Two-View Gravity Stress Imaging Protocol for Nondisplaced Type II Supination External Rotation Ankle Fractures: Introducing the Gravity Stress Cross-Table Lateral View.

PubMed

Boffeli, Troy J; Collier, Rachel C; Gervais, Samuel J

Assessing ankle stability in nondisplaced Lauge-Hansen supination external rotation type II injuries requires stress imaging. Gravity stress mortise imaging is routinely used as an alternative to manual stress imaging to assess deltoid integrity with the goal of differentiating type II from type IV injuries in cases without a posterior or medial fracture. A type II injury with a nondisplaced fibula fracture is typically treated with cast immobilization, and a type IV injury is considered unstable and often requires operative repair. The present case series (two patients) highlights a standardized 2-view gravity stress imaging protocol and introduces the gravity stress cross-table lateral view. The gravity stress cross-table lateral view provides a more thorough evaluation of the posterior malleolus owing to the slight external rotation and posteriorly directed stress. External rotation also creates less bony overlap between the tibia and fibula, allowing for better visualization of the fibula fracture. Gravity stress imaging confirmed medial-sided injury in both cases, confirming the presence of supination external rotation type IV or bimalleolar equivalent fractures. Open reduction and internal fixation was performed, and both patients achieved radiographic union. No further treatment was required at 21 and 33 months postoperatively. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Radiographic evaluation of acute distal radius fracture stability: A comparative cadaveric study between a thermo-formable bracing system and traditional fiberglass casting.

PubMed

Santoni, Brandon G; Aira, Jazmine R; Diaz, Miguel A; Kyle Stoops, T; Simon, Peter

2017-08-01

Distal radius fractures are common musculoskeletal injuries and many can be treated non-operatively with cast immobilization. A thermo-formable brace has been developed for management of such fractures, but no data exist regarding its comparative stabilizing efficacy to fiberglass casting. A worst-case distal radius fracture was created in 6 cadaveric forearms. A radiolucent loading fixture was created to apply cantilever bending/compression loads ranging from 4.5N to 66.7N across the simulated fracture in the: (1) non-stabilized, (2) braced; and (3) casted forearms, each forearm serving as its own control. Fracture fragment translations and rotations were measured radiographically using orthogonal radiographs and a 2D-3D, CT-based transformation methodology. Under 4.5N of load in the non-stabilized condition, average sagittal plane rotation and 3D center of mass translation of the fracture fragment were 12.3° and 5.3mm, respectively. At the 4.5N load step, fragment rotation with the brace (avg. 0.0°) and cast (0.1°) reduced sagittal plane rotation compared to the non-stabilized forearm (P<0.001). There were no significant differences in measured sagittal plane fracture fragment rotations or 3D fragment translations between the brace or cast at any of the four load steps (4.5N, 22.2N, 44.5N, and 66.7N, P≥0.138). In this in vitro radiographic study utilizing 6 cadaveric forearms with simulated severe-case, unstable and comminuted distal radius fractures, the thermo-formable brace stabilized the fracture in a manner that was not radiographically or biomechanically different from traditional fiberglass casting. Study results support the use of the thermo-formable brace clinically. Copyright © 2017 Elsevier Ltd. All rights reserved.

Brittle and Ductile Behavior in Deep-Seated Landslides: Learning from the Vajont Experience

NASA Astrophysics Data System (ADS)

Paronuzzi, Paolo; Bolla, Alberto; Rigo, Elia

2016-06-01

This paper analyzes the mechanical behavior of the unstable Mt. Toc slope before the 1963 catastrophic collapse, considering both the measured data (surface displacements and microseismicity) and the updated geological model of the prehistoric rockslide. From February 1960 up to 9 October 1963, the unstable mass behaved as a brittle-ductile `mechanical system,' characterized by remarkable microseismicity as well as by considerable surface displacements (up to 4-5 m). Recorded microshocks were the result of progressive rock fracturing of distinct resisting stiff parts made up of intact rock (indentations, undulations, and rock bridges). The main resisting stiff part was a large rock indentation located at the NE extremity of the unstable mass that acted as a mechanical constraint during the whole 1960-1963 period, inducing a progressive rototranslation toward the NE. This large constraint failed in autumn 1960, when an overall slope failure took place, as emphasized by the occurrence of the large perimetrical crack in the upper slope. In this circumstance, the collapse was inhibited by a reblocking phenomenon of the unstable mass that had been previously destabilized by the first reservoir filling. Progressive failure of localized intact rock parts progressively propagated westwards as a consequence of the two further filling-drawdown cycles of the reservoir (1962 and 1963). The characteristic brittle-ductile behavior of the Vajont landslide was made possible by the presence of a very thick (40-50 m) and highly deformable shear zone underlying the upper rigid rock mass (100-120 m thick).

Damage Instability and Transition From Quasi-Static to Dynamic Fracture

NASA Technical Reports Server (NTRS)

Davila, Carlos G.

2015-01-01

In a typical mechanical test, the loading phase is intended to be a quasi-static process, while the failure and collapse is usually a dynamic event. The structural strength and modes of damage can seldom be predicted without accounting for these two aspects of the response. For a proper prediction, it is therefore essential to use tools and methodologies that are capable of addressing both aspects of responses. In some cases, implicit quasi-static models have been shown to be able to predict the entire response of a structure, including the unstable path that leads to fracture. However, is it acceptable to ignore the effect of inertial forces in the formation of damage? In this presentation we examine aspects of the damage processes that must be simulated for an accurate prediction of structural strength and modes of failure.

Detection of water contamination from hydraulic fracturing wastewater: a μPAD for bromide analysis in natural waters.

PubMed

Loh, Leslie J; Bandara, Gayan C; Weber, Genevieve L; Remcho, Vincent T

2015-08-21

Due to the rapid expansion in hydraulic fracturing (fracking), there is a need for robust, portable and specific water analysis techniques. Early detection of contamination is crucial for the prevention of lasting environmental damage. Bromide can potentially function as an early indicator of water contamination by fracking waste, because there is a high concentration of bromide ions in fracking wastewaters. To facilitate this, a microfluidic paper-based analytical device (μPAD) has been developed and optimized for the quantitative colorimetric detection of bromide in water using a smartphone. A paper microfluidic platform offers the advantages of inexpensive fabrication, elimination of unstable wet reagents, portability and high adaptability for widespread distribution. These features make this assay an attractive option for a new field test for on-site determination of bromide.

The deformation of the front of a 3D interface crack propagating quasistatically in a medium with random fracture properties

NASA Astrophysics Data System (ADS)

Pindra, Nadjime; Lazarus, Véronique; Leblond, Jean-Baptiste

One studies the evolution in time of the deformation of the front of a semi-infinite 3D interface crack propagating quasistatically in an infinite heterogeneous elastic body. The fracture properties are assumed to be lower on the interface than in the materials so that crack propagation is channelled along the interface, and to vary randomly within the crack plane. The work is based on earlier formulae which provide the first-order change of the stress intensity factors along the front of a semi-infinite interface crack arising from some small but otherwise arbitrary in-plane perturbation of this front. The main object of study is the long-time behavior of various statistical measures of the deformation of the crack front. Special attention is paid to the influences of the mismatch of elastic properties, the type of propagation law (fatigue or brittle fracture) and the stable or unstable character of 2D crack propagation (depending on the loading) upon the development of this deformation.

Delamination micromechanics analysis

NASA Technical Reports Server (NTRS)

Adams, D. F.; Mahishi, J. M.

1985-01-01

A three-dimensional finite element analysis was developed which includes elastoplastic, orthotropic material response, and fracture initiation and propagation. Energy absorption due to physical failure processes characteristic of the heterogeneous and anisotropic nature of composite materials is modeled. A local energy release rate in the presence of plasticity was defined and used as a criterion to predict the onset and growth of cracks in both micromechanics and macromechanics analyses. This crack growth simulation technique is based upon a virtual crack extension method. A three-dimensional finite element micromechanics model is used to study the effects of broken fibers, cracked matrix and fiber-matrix debond on the fracture toughness of the unidirectional composite. The energy release rates at the onset of unstable crack growth in the micromechanics analyses are used as critical energy release rates in the macromechanics analysis. This integrated micromechanical and macromechanical fracture criterion is shown to be very effective in predicting the onset and growth of cracks in general multilayered composite laminates by applying the criterion to a single-edge notched graphite/epoxy laminate subjected to implane tension normal to the notch.

Intraoperative reduction of the scapular body--a technical trick.

PubMed

Bartonícek, Jan; Fric, Vladimír; Tucek, Michal

2009-04-01

When internal fixation of the scapular neck and body fractures is performed, a problem may occur with reduction and retention of position of the lateral border of the scapula during surgery. For this purpose, the authors have developed their own technique of stabilization using a K-wire in a novel way. The technique is indicated in a 2-part shear unstable fracture of the lateral border. It cannot be used in fractures with an intercalated segment. A 2.5-mm drill bit is used to drill a 1.5-cm deep hole into the "medullary cavity" of each of the 2 fragments of the lateral border. A K-wire, 1.5 mm in diameter and 2.5-cm long, is inserted into the distal fragment. The protruding end of the K-wire is inserted into the hole in the proximal fragment. This intramedullary peg helps to maintain reduction and keeps both fragments stable. Subsequently, the lateral border is stabilized with a 3.5-mm reconstruction plate. This technique is quite simple and allows for a temporary stabilization of fragments without compromising the subsequent fixation by plate screws.

Dietary patterns explaining differences in bone mineral density and hip structure in the elderly: the Rotterdam Study.

PubMed

de Jonge, Ester Al; Kiefte-de Jong, Jessica C; Hofman, Albert; Uitterlinden, André G; Kieboom, Brenda Ct; Voortman, Trudy; Franco, Oscar H; Rivadeneira, Fernando

2017-01-01

Evidence on the association between dietary patterns, measures of hip bone geometry, and subsequent fracture risk are scarce. The objective of this study was to evaluate whether dietary patterns that explain most variation in bone mineral density (BMD) and hip bone geometry are associated with fracture risk. We included 4028 subjects aged ≥55 y from the Rotterdam study. Intake of 28 food groups was assessed with the use of food-frequency questionnaires. BMD, bone width, section modulus (SM; reflecting bending strength) and cortical buckling ratio (BR; reflecting bone instability) were measured with the use of dual-energy X-ray absorptiometry. BMD and geometry-specific dietary patterns were identified with the use of reduced rank regression. Fracture data were reported by general practitioners (median follow-up 14.8 y). We identified 4 dietary patterns. Of the 4, we named 2 patterns "fruit, vegetables, and dairy" and "sweets, animal fat, and low meat," respectively. These 2 patterns were used for further analysis. Independently of confounders, adherence to the fruit, vegetables, and dairy pattern was associated with high BMD, high SM, low BR, and low risk of fractures [HR (95% CI) for osteoporotic fractures: 0.90 (0.83, 0.96); for hip fractures: 0.85 (0.81, 0.89) per z score of dietary pattern adherence]. Adherence to the sweets, animal fat, and low meat pattern was associated with high bone width, high SM, high BR, and high risk of fractures [HR (95% CI) for osteoporotic fractures: 1.08 (1.00, 1.06); for hip fractures: 1.06 (1.02, 1.12) per z score]. The fruit, vegetables, and dairy pattern might be associated with lower fracture risk because of high BMD, high bending strength, and more stable bones. The sweets, animal fat, and low meat pattern might be associated with higher fracture risk because of widened, unstable bones, independently of BMD. Dietary recommendations associated with bone geometry in addition to BMD might influence risk of fractures. © 2017 American Society for Nutrition.

On the interfacial fracture of porcelain/zirconia and graded zirconia dental structures.

PubMed

Chai, Herzl; Lee, James J-W; Mieleszko, Adam J; Chu, Stephen J; Zhang, Yu

2014-08-01

Porcelain fused to zirconia (PFZ) restorations are widely used in prosthetic dentistry. However, their susceptibility to fracture remains a practical problem. The failure of PFZ prostheses often involves crack initiation and growth in the porcelain, which may be followed by fracture along the porcelain/zirconia (P/Z) interface. In this work, we characterized the process of fracture in two PFZ systems, as well as a newly developed graded glass-zirconia structure with emphases placed on resistance to interfacial cracking. Thin porcelain layers were fused onto Y-TZP plates with or without the presence of a glass binder. The specimens were loaded in a four-point-bending fixture with the thin porcelain veneer in tension, simulating the lower portion of the connectors and marginal areas of a fixed dental prosthesis (FDP) during occlusal loading. The evolution of damage was observed by a video camera. The fracture was characterized by unstable growth of cracks perpendicular to the P/Z interface (channel cracks) in the porcelain layer, which was followed by stable cracking along the P/Z interface. The interfacial fracture energy GC was determined by a finite-element analysis taking into account stress-shielding effects due to the presence of adjacent channel cracks. The resulting GC was considerably less than commonly reported values for similar systems. Fracture in the graded Y-TZP samples occurred via a single channel crack at a much greater stress than for PFZ. No delamination between the residual glass layer and graded zirconia occurred in any of the tests. Combined with its enhanced resistance to edge chipping and good esthetic quality, graded Y-TZP emerges as a viable material concept for dental restorations. Copyright © 2014 Acta Materialia Inc. All rights reserved.

Study of the Rock Mass Failure Process and Mechanisms During the Transformation from Open-Pit to Underground Mining Based on Microseismic Monitoring

NASA Astrophysics Data System (ADS)

Zhao, Yong; Yang, Tianhong; Bohnhoff, Marco; Zhang, Penghai; Yu, Qinglei; Zhou, Jingren; Liu, Feiyue

2018-05-01

To quantitatively understand the failure process and failure mechanism of a rock mass during the transformation from open-pit mining to underground mining, the Shirengou Iron Mine was selected as an engineering project case study. The study area was determined using the rock mass basic quality classification method and the kinematic analysis method. Based on the analysis of the variations in apparent stress and apparent volume over time, the rock mass failure process was analyzed. According to the recent research on the temporal and spatial change of microseismic events in location, energy, apparent stress, and displacement, the migration characteristics of rock mass damage were studied. A hybrid moment tensor inversion method was used to determine the rock mass fracture source mechanisms, the fracture orientations, and fracture scales. The fracture area can be divided into three zones: Zone A, Zone B, and Zone C. A statistical analysis of the orientation information of the fracture planes orientations was carried out, and four dominant fracture planes were obtained. Finally, the slip tendency analysis method was employed, and the unstable fracture planes were obtained. The results show: (1) The microseismic monitoring and hybrid moment tensor analysis can effectively analyze the failure process and failure mechanism of rock mass, (2) during the transformation from open-pit to underground mining, the failure type of rock mass is mainly shear failure and the tensile failure is mostly concentrated in the roof of goafs, and (3) the rock mass of the pit bottom and the upper of goaf No. 18 have the possibility of further damage.

Biomechanical Assessment of the Dorsal Spanning Bridge Plate in Distal Radius Fracture Fixation: Implications for Immediate Weight-Bearing.

PubMed

Huang, Jerry I; Peterson, Bret; Bellevue, Kate; Lee, Nicolas; Smith, Sean; Herfat, Safa

2017-04-01

The goal of this study was to compare the biomechanical stability of a 2.4-mm dorsal spanning bridge plate with a volar locking plate (VLP) in a distal radius fracture model, during simulated crutch weight-bearing. Five paired cadaveric forearms were tested. A 1-cm dorsal wedge osteotomy was created to simulate an unstable distal radius fracture with dorsal comminution. Fractures were fixed with a VLP or a dorsal bridge plate (DBP). Specimens were mounted to a crutch handle, and optical motion-tracking sensors were attached to the proximal and distal segments. Specimens were loaded in compression at 1 mm/s on a servohydraulic test frame until failure, defined as 2 mm of gap site displacement. The VLP construct was significantly more stable to axial load in a crutch weight-bearing model compared with the DBP plate (VLP: 493 N vs DBP: 332 N). Stiffness was higher in the VLP constructs, but this was not statistically significant (VLP: 51.4 N/mm vs DBP: 32.4 N/mm). With the crutch weight-bearing model, DBP failed consistently with wrist flexion and plate bending, whereas VLP failed with axial compression at the fracture site and dorsal collapse. Dorsal spanning bridge plating is effective as an internal spanning fixator in treating highly comminuted intra-articular distal radius fracture and prevents axial collapse at the radiocarpal joint. However, bridge plating may not offer advantages in early weight-bearing or transfer in polytrauma patients, with less axial stability in our crutch weight-bearing model compared with volar plating. A stiffer 3.5-mm DBP or use of a DBP construct without the central holes may be considered for distal radius fractures if the goal is early crutch weight-bearing through the injured extremity.

A biomechanical comparison of four fixed-angle dorsal plates in a finite element model of dorsally-unstable radius fracture.

PubMed

Knežević, Josip; Kodvanj, Janoš; Čukelj, Fabijan; Pamuković, Frane; Pavić, Arsen

2017-11-01

To compare the finite element models of two different composite radius fracture patterns, reduced and stabilised with four different fixed-angle dorsal plates during axial, dorsal and volar loading conditions. Eight different plastic models representing four AO/ASIF type 23-A3 distal radius fractures and four AO/ASIF 23-C2 distal radius fractures were obtained and fixed each with 1 of 4 methods: a standard dorsal non-anatomical fixed angle T-plate (3.5mm Dorsal T-plate, Synthes), anatomical fixed-angle double plates (2.4mm LCP Dorsal Distal Radius, Synthes), anatomical fixed angle T-plate (2.4mm Acu-Loc Dorsal Plate, Acumed) or anatomical variable-angle dorsal T-plate (3.5mm, Dorsal Plate, Zrinski). Composite radius with plate and screws were scanned with a 3D optical scanner and later processed in Abaqus Software to generate the finite element model. All models were axially loaded at 3 points (centrally, volarly and dorsally) with 50 N forces to avoid the appearance of plastic deformations of the models. Total displacements at the end of the bone and the stresses in the bones and plates were determined and compared. Maximal von Mises stress in bone for 3-part fracture models was very similar to that in 2-part fracture models. The biggest difference between models and the largest displacements were seen during volar loading. The stresses in all models were the highest above the fracture gap. The best performance in all parameters tested was with the Zrinski plate and the most modest results were with the Synthes T-plate. There was no significant difference between 2-part (AO/ASIF type 23-A3) and 3-part (AO/ASIF 23-C2) fracture models. Maximal stresses in the plates appeared above the fracture gap; therefore, it is worth considering the development of plates without screw holes above the gap. © 2017 Elsevier Ltd. All rights reserved.

The use of weightbearing radiographs to assess the stability of supination-external rotation fractures of the ankle.

PubMed

Weber, Martin; Burmeister, Helge; Flueckiger, Gerhard; Krause, Fabian G

2010-05-01

Isolated lateral malleolar fractures usually result from a supination-external rotation (SER) injury and may include a deltoid ligament rupture. The necessity of operative treatment is based on the recognition of a relevant medial soft-tissue disruption. Currently used tests to assess ankle stability include manual stress radiographs and gravity stress radiographs, but seem to overestimate the need for fracture fixation. We investigated the use of weightbearing radiographs to distinguish stable and unstable isolated lateral malleolar fractures induced by the SER mechanism in 57 patients. Patients with stable fractures (SER type II according to the Lauge-Hansen classification) were treated non-operatively with varying external support. Forty-seven patients were evaluated by questionnaire and AOFAS ankle-hindfoot score. Follow-up was 18-120 months (mean 62). Fifty-one of fifty-seven (90%) patients were found to have stable fractures (SER type II) and were treated nonoperatively. The AOFAS score was 96.1 points on average (range 85-100) at latest follow-up. Four patients reported minor complaints. A "moderate" correlation of risk factors (i.e. smoking) to delayed bone healing was found while the correlation of varying external support (i.e. bandage, cast) to the AOFAS score and delayed bone healing was "poor". The use of weightbearing radiographs is an easy, pain-free, safe and reliable method to exclude the need for operative treatment, with excellent clinical outcome in the majority of the patients seen at latest follow-up. The delay of 3-10 days until the decision about surgical treatment is well accepted by the patients.

Early results of a simple distraction dynamic external fixator in management of comminuted intra-articular fractures of base of middle phalanx.

PubMed

Mansha, Muhammad; Miranda, Sanjay

2013-12-01

Treatment for comminuted fracture dislocations of the proximal interphalangeal joint (pilon injuries) remains a challenge. We present our short term results of twelve pilon fracture dislocations treated by closed reduction and application of a distraction dynamic external fixator. The aim of the study was to assess the clinical outcomes and compare them to the original description by Hynes and Giddins. A cohort of 12 consecutive patients with pilon fracture of the proximal interphalangeal joint (comminuted fracture of the base of middle phalanx, longitudinally unstable with joint subluxation), were treated with this method over the study period. Data was collected by an independent observer at last follow-up appointment in the clinic. The outcome measures recorded were; level of residual pain, arc of motion, X-ray appearance, return to work and satisfaction with the procedure. The study group comprises of 7 male and 5 female patients at a mean age of 38.1 years (range 21-70 years). The average range of movement achieved was 13-87° at a mean follow-up of 16.4 weeks (Range 12-42 weeks). Early return to work, good pain relief and high level of patient satisfaction were achieved. No serious complication was noted during this period. We used the construct with slight modification of the original description and we feel this modification may help to reduce the pin site infection. We found the results reproducible and based on our experience we recommend this technique to treat these complex intra-articular fractures of base of middle phalanx.

Inertial and stick-slip regimes of unstable adhesive tape peeling.

PubMed

Dalbe, Marie-Julie; Villey, Richard; Ciccotti, Matteo; Santucci, Stéphane; Cortet, Pierre-Philippe; Vanel, Loïc

2016-05-18

We present an experimental characterization of the detachment front unstable dynamics observed during the peeling of pressure sensitive adhesives. We use an experimental set-up specifically designed to control the peeling angle θ and the peeled tape length L, while peeling an adhesive tape from a flat substrate at a constant driving velocity V. High-speed imaging allows us to report the evolution of the period and amplitude of the front oscillations, as well as the relative durations of their fast and slow phases, as a function of the control parameters V, L and θ. Our study shows that, as the driving velocity or the peeling angle increases, the oscillations of the peeling front progressively evolve from genuine "stick-slip" oscillations, made of alternating long stick phases and very brief slip phases, to sinusoidal oscillations of amplitude twice the peeling velocity. We propose a model which, taking into account the peeling angle-dependent kinetic energy cost to accelerate and decelerate the peeled tape, explains the transition from the "stick-slip" to the "inertial" regime of the dynamical instability. Using independent direct measurements of the effective fracture energy of the adhesive-substrate joint, we show that our model quantitatively accounts for the two regimes of the unstable dynamics.

Compressive rib fracture: peri-mortem and post-mortem trauma patterns in a pig model.

PubMed

Kieser, Jules A; Weller, Sarah; Swain, Michael V; Neil Waddell, J; Das, Raj

2013-07-01

Despite numerous studies on high impact fractures of ribs, little is known about compressive rib injuries. We studied rib fractures from a biomechanical and morphological perspective using 15, 5th ribs of domestic pigs Sus scrofa, divided into two groups, desiccated (representing post-mortem trauma) and fresh ribs with intact periosteum (representing peri-mortem trauma). Ribs were axially compressed and subjected to four-point bending in an Instron 3339 fitted with custom jigs. Morphoscopic analysis of resultant fractures consisted of standard optical methods, micro-CT (μCT) and scanning electron microscopy (SEM). During axial compression, fresh ribs had slightly higher strength because of energy absorption capabilities of their soft and fluidic components. In flexure tests, dry ribs showed typical elastic-brittle behaviour with long linear load-extension curves, followed by relatively short non-linear elastic (hyperelastic) behaviour and brittle fracture. Fresh ribs showed initial linear-elastic behaviour, followed by strain softening, visco-plastic responses. During the course of loading, dry bone showed minimal observable damage prior to the onset of unstable fracture. In contrast, fresh bone showed buckling-like damage features on the compressive surface and cracking parallel to the axis of the bone. Morphologically, all dry ribs fractured precipitously, whereas all but one of the fresh ribs showed incomplete fracture. The mode of fracture, however, was remarkably similar for both groups, with butterfly fractures predominating (7/15, 46.6% dry and wet). Our study highlights the fact that under controlled loading, despite seemingly similar butterfly fracture morphology, fresh ribs (representing perimortem trauma) show a non-catastrophic response. While extensive strain softening observed for the fresh bone does show some additional micro-cracking damage, it appears that the periosteum may play a key role in imparting the observed pseudo-ductility to the ribs. The presence of fibrous pull-out and grooving of the outer tensile surface associated with periosteal stretching suggests that the periosteum under tension is able to sustain very high strain and bridge the mouth of the extending butterfly crack, thereby contributing to the observed strain-softening behaviour. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Fragility fractures of the ankle in the elderly: Open reduction and internal fixation versus tibio-talo-calcaneal nailing: Short-term results of a prospective randomized-controlled study.

PubMed

Georgiannos, D; Lampridis, V; Bisbinas, I

2017-02-01

The management of ankle fractures in the elderly remains unpredictable, secondary to their various co-morbidities. Although tibiotalocalcaneal (TTC) nailing has been an effective option for ankle arthrodesis due to ankle arthritis or Charcot arthropathy there are few reports regarding the use of TTC nail for the treatment of ankle fractures. Aim of this study was to compare the results of ORIF versus TTC nailing for the treatment of unstable ankle fractures in the elderly. We hypothesized that the elderly may benefit from TTC nailing, as it allows the patient to be mobilized immediately after surgery and minimizes the risk of wound or bone problems. This was a prospective, randomized-controlled, comparative study. Between 2009 and 2015, 43 patients were treated with a TTC nail (Group A) and 44 with ORIF (Group B). The Olerud-Molander ankle score was obtained and intraoperative-postoperative complications, length of hospital stay, mobility status and reoperation rate were recorded. The nail fixation was performed with the TrigenR hindfoot nail after closed reduction. ORIF was performed, using a 1/3 tubular plate and 3.5mm screws for the lateral malleolus and two 4.0 mm cannulated screws for the medial. Mortality rate at one year was 13.9% for Group A and 18.1% for Group B. Mean follow-up was 14 months (12-18m). There were no intraoperative complications. Three complications in Group A (8.1%) and twelve (33.3%) in Group B were encountered postoperatively (p<0.05). There was significant shorter hospital stay in Group A (5.2±3.1d) than in Group B (8.4±5.2d). In Group A, 28 patients returned to their pre-injury mobility status (75.6%) while 9 declined one level of the mobility scale (24.3%). In Group B, 26 patients remained at the same mobility level (72.2%) and 10 declined one level (27.7%). There was no significant difference between the postoperative OMAS scores in the two Groups (56.9±9.85 and 56.6±9.3 respectively). We believe that TTC nailing is a safe and effective method of treatment of unstable ankle fractures in the elderly because it has a low risk of complications and restores function and mobility allowing an immediate return to full weight-bearing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Immediate management of posterior urethral disruptions due to pelvic fracture: therapeutic alternatives.

PubMed

Podestá, M L; Medel, R; Castera, R; Ruarte, A

1997-04-01

We retrospectively reviewed the results of 3 types of initial management of pelvic fracture urethral disruption in children. From 1980 to 1994, 35 boys 2 to 15 years old (mean age 8.1) with prostatomembranous urethral disruption were treated, including 17 who also had associated injuries. Immediate treatment included suprapubic cystostomy and delayed urethroplasty in 19 patients (group 1), urethral catheter alignment without traction and concomitant suprapubic cystostomy in 10 (group 2), and primary retropubic anastomotic urethroplasty in 6 (group 3). In all patients in groups 1 and 2 severe urethral obliteration developed. Four group 3 patients (66%) had a stricture at the site of anastomotic repair. After delayed urethroplasty 16 group 1 (84%) and all 10 group 2 patients were continent. However, only 3 group 3 patients (50%) achieved continence. Retrospectively associated bladder neck injury occurred in 5 of the 6 incontinent boys. Erections were observed before and after treatment in all but 3 children. Unstable pelvic ring fractures (type IV) comprised 28% of all pelvic fractures with a high rate of associated injuries. As described, urethral alignment was not beneficial for avoiding urethral obliteration. Therefore we recommend suprapublic cystostomy as the only form of initial treatment in these cases. Urinary incontinence seems more likely related to associated bladder neck rupture and the severity of pelvic fracture rather than to initial treatment or delayed urethral repair. Consequently, when associated bladder neck injury is present, we advocate immediate surgical repair.

Engineering Evaluation of International Low Impact Docking System Latch Hooks

NASA Technical Reports Server (NTRS)

Martinez, J.; Patin, R.; Figert, J.

2013-01-01

The international Low Impact Docking System (iLIDS) provides a structural arrangement that allows for visiting vehicles to dock with the International Space Station (ISS) (Fig 1). The iLIDS docking units are mechanically joined together by a series of active and passive latch hooks. In order to preserve docking capability at the existing Russian docking interfaces, the iLIDS latch hooks are required to conform to the existing Russian design. The latch hooks are classified as being fail-safe. Since the latch hooks are fail-safe, the hooks are not fracture critical and a fatigue based service life assessment will satisfy the structural integrity requirements. Constant amplitude fatigue testing to failure on four sets of active/passive iLIDS latch hooks was performed at load magnitudes of 10, 11, and 12 kips. Failure analysis of the hook fatigue failures identified multi-site fatigue initiation that was effectively centered about the hook mid-plane (consistent with the 3D model results). The fatigue crack initiation distribution implies that the fatigue damage accumulation effectively results in a very low aspect ratio surface crack (which can be simulated as thru-thickness crack). Fatigue damage progression resulted in numerous close proximity fatigue crack initiation sites. It was not possible to determine if fatigue crack coalescence occurs during cyclic loading or as result of the fast fracture response. The presence of multiple fatigue crack initiation sites on different planes will result in the formation of ratchet marks as the cracks coalesce. Once the stable fatigue crack becomes unstable and the fast fracture advances across the remaining ligament and the plane stress condition at a free-surface will result in failure along a 45 deg. shear plane (slant fracture) and the resulting inclined edge is called a shear lip. The hook thickness on the plane of fatigue crack initiation is 0.787". The distance between the shear lips on this plane was on the order of 0.48" and it was effectively centered about the mid-plane of the section. The numerous ratchet marks between the shear lips on the fracture initiation plane are indicative of multiple fatigue initiation sites within this region. The distribution of the fatigue damage about the centerline of the hook is consistent with the analytical results that demonstrate peak stress/strain response at the mid-plane that decreases in the direction of the hook outer surfaces. Scanning electron microscope images of the failed sections detected fatigue crack striations in close proximity to the free surface of the hook radius. These findings were documented at three locations on the fracture surface : 1) adjacent to the left shear lip, 2) adjacent to the right shear lip, and 3) near the centerline of the section. The features of the titanium fracture surface did not allow for a determination of a critical crack size via identification of the region where the fatigue crack propagation became unstable. The fracture based service life projections where benchmarked with strain-life analyses. The strainrange response in the hook radius was defined via the correlated finite element models and the modified method of universal slopes was incorporated to define the strain-life equation for the titanium alloy. The strain-life assessment confirmed that the fracture based projections were reasonable for the loading range of interest. Based upon the analysis and component level fatigue test data a preliminary service life capability for the iLIDS active and passive hooks of 2 lifetimes is projected (includes a scatter factor of 4).

Navigation-aided visualization of lumbosacral nerves for anterior sacroiliac plate fixation: a case report.

PubMed

Takao, Masaki; Nishii, Takashi; Sakai, Takashi; Sugano, Nobuhiko

2014-06-01

Anterior sacroiliac joint plate fixation for unstable pelvic ring fractures avoids soft tissue problems in the buttocks; however, the lumbosacral nerves lie in close proximity to the sacroiliac joint and may be injured during the procedure. A 49 year-old woman with a type C pelvic ring fracture was treated with an anterior sacroiliac plate using a computed tomography (CT)-three-dimensional (3D)-fluoroscopy matching navigation system, which visualized the lumbosacral nerves as well as the iliac and sacral bones. We used a flat panel detector 3D C-arm, which made it possible to superimpose our preoperative CT-based plan on the intra-operative 3D-fluoroscopic images. No postoperative complications were noted. Intra-operative lumbosacral nerve visualization using computer navigation was useful to recognize the 'at-risk' area for nerve injury during anterior sacroiliac plate fixation. Copyright © 2013 John Wiley & Sons, Ltd.

Atomistic Origin of Deformation Twinning in Biomineral Aragonite.

PubMed

Liu, Jialin; Huang, Zaiwang; Pan, Zhiliang; Wei, Qiuming; Li, Xiaodong; Qi, Yue

2017-03-10

Deformation twinning rarely occurs in mineral materials which typically show brittle fracture. Surprisingly, it has recently been observed in the biomineral aragonite phase in nacre under high rate impact loading. In this Letter, the twinning tendency and the competition between fracture and deformation twinning were revealed by first principles calculations. The ratio of the unstable stacking fault energy and the stacking fault energy in orthorhombic aragonite is hitherto the highest in a broad range of metallic and oxide materials. The underlining physics for this high ratio is the multineighbor shared ionic bonds and the unique relaxation process during sliding in the aragonite structure. Overall, the unique deformation twining along with other highly coordinated deformation mechanisms synergistically work in the hierarchical structure of nacre, leading to the remarkable strengthening and toughening of nacre upon dynamic loading, and thus protecting the mother-of-pearl from predatory attacks.

Glacial seismology.

PubMed

Aster, R C; Winberry, J P

2017-12-01

Seismic source and wave propagation studies contribute to understanding structure, transport, fracture mechanics, mass balance, and other processes within glaciers and surrounding environments. Glaciogenic seismic waves readily couple with the bulk Earth, and can be recorded by seismographs deployed at local to global ranges. Although the fracturing, ablating, melting, and/or highly irregular environment of active glaciers can be highly unstable and hazardous, informative seismic measurements can commonly be made at stable proximal ice or rock sites. Seismology also contributes more broadly to emerging studies of elastic and gravity wave coupling between the atmosphere, oceans, solid Earth, and cryosphere, and recent scientific and technical advances have produced glaciological/seismological collaborations across a broad range of scales and processes. This importantly includes improved insight into the responses of cryospheric systems to changing climate and other environmental conditions. Here, we review relevant fundamental physics and glaciology, and provide a broad review of the current state of glacial seismology and its rapidly evolving future directions.

Glacial seismology

NASA Astrophysics Data System (ADS)

Aster, R. C.; Winberry, J. P.

2017-12-01

Seismic source and wave propagation studies contribute to understanding structure, transport, fracture mechanics, mass balance, and other processes within glaciers and surrounding environments. Glaciogenic seismic waves readily couple with the bulk Earth, and can be recorded by seismographs deployed at local to global ranges. Although the fracturing, ablating, melting, and/or highly irregular environment of active glaciers can be highly unstable and hazardous, informative seismic measurements can commonly be made at stable proximal ice or rock sites. Seismology also contributes more broadly to emerging studies of elastic and gravity wave coupling between the atmosphere, oceans, solid Earth, and cryosphere, and recent scientific and technical advances have produced glaciological/seismological collaborations across a broad range of scales and processes. This importantly includes improved insight into the responses of cryospheric systems to changing climate and other environmental conditions. Here, we review relevant fundamental physics and glaciology, and provide a broad review of the current state of glacial seismology and its rapidly evolving future directions.

[Mathematical model of oblique three-dimensional intertrochanteric detorsion varus-forming osteotomy of the femur by the Bernbeck method in surgical treatment of congenital hip dysplasia in children].

PubMed

Bohatyrewicz, A

1992-01-01

Whenever the conservative procedure fails to bring about congruence of the dysplastic hip joint, an operative procedure becomes indispensable. In Orthopaedic Clinic of the Pomeranian Medical Academy in Szczecin we implement the oblique three-dimensional intertrochanteric detorsion and varus forming osteotomy after Bernbeck in order to correct the proximal end of the femoral bone. Precise determination of the plane to be cut, prior to the operative procedure, simplifies and shortens the operation itself and facilitates the achieving of the planned angular values in all three planes. Mathematical model of osteotomy according to Bernbeck considering required angles of correction as well as angles determining the plane of osteotomy was worked out. In collaboration of the Szczecin Technical University, a simple computer program was elaborated which allowed the presentation of the results in the form of tables. With the help of tables the optimal cutting plane was chosen and created correct biomechanical and anatomical conditions as well as optimal conditions for stable osteosynthesis of dissected fragments of the femoral bone. That type of osteotomy is useful in most operative correcrions of the dysplastic hip joint (not great varus formation connected with relatively extensive detorsion). The achieved congruence in the 22 dysplastic hip joints operated on was the most important condition for their later physiological development. Short post-operative observations confirm the value of described mathematic model.

Pore-level influence of micro-fracture parameters on visco-capillary behavior of two-phase displacements in porous media

NASA Astrophysics Data System (ADS)

Rokhforouz, M. R.; Akhlaghi Amiri, H. A.

2018-03-01

In this work, coupled Cahn-Hilliard phase field and Navier-Stokes equations were solved using finite element method to address the effects of micro-fracture and its characterizations on water-oil displacements in a heterogeneous porous medium. Sensitivity studies at a wide range of viscosity ratios (M) and capillary numbers (Ca), and the resultant log Ca-log M stability phase diagram, revealed that in both media, with/without fracture, the three regimes of viscous fingering, capillary fingering and stable displacement similarly occur. However, presence of the fracture caused water channeling phenomenon which resulted in reduction of the number of active fingers and hence the final oil recovery factor. At high Ca (especially in the stable regime, with log Ca ≥ -2.5 and log M ≥ 0), recovery factor for the fractured medium was relatively identical with the non-fractured one. At log M ≥ 0, the fracture was fully swept, but flow instabilities were observed inside the fracture at lower M values, especially for log Ca > -4.6. In the case of the fractured medium at log Ca = -4.6 and log M = 0 (capillary dominant flow), it is observed that the primary breakthrough took place by a finger progressed through the matrix, not those channeled through the fracture. Geometrical properties of the fracture, including length, aperture and orientation, highly affected both displacement profile and efficiency. The fracture length inversely influenced the oil recovery factor. It was observed that there is a critical fracture width (almost half of the medium average pore diameter) at which the recovery factor of the medium during displacement is minimum, compared to the media having thinner and thicker fractures. Minor channeling effect in the media with thinner fracture and larger fracture swept volume as well as high fracture/matrix cross flow in the media with thicker fracture were detected as the main cause of this non-monotonic behavior. In the models with thick fractures (with the thickness higher than the average pore diameter), considerable trapped oil volumes were observed inside the fracture at low M values. The fracture orientation had the most impressive effect on oil recovery compared to the other studied parameters; where the oil recovery factor incremented more than 20% as the fracture rotated 90° from flow direction. Due to the dominant effect of the channeling phenomenon, the change in the medium wettability from slightly oil-wet to slightly water-wet, did not considerably affect the displacement profile in the fractured medium. However, oil recovery factor increased as the medium became more water-wet. The fracture area was fully swept by the injected water in the oil-wet and neutral-wet media. However, flow instabilities were observed inside the fracture of the water-wet medium due to counter-current imbibition between fracture/matrix. Micro-scale mechanisms of pore doublet effect, interface coalesce, snap-off and reverse movements were captured during the studied unstable displacements.

On the physics of unstable infiltration, seepage, and gravity drainage in partially saturated tuffs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faybishenko, B.; Bodvarsson, G.S.; Salve, R.

2002-04-01

To improve understanding of the physics of dynamic instabilities in unsaturated flow processes within the Paintbrush nonwelded unit (PTn) and the middle nonlithophysal portion of the Tonopah Spring welded tuff unit (TSw) of Yucca Mountain, we analyzed data from a series of infiltration tests carried out at two sites (Alcove 4 and Alcove 6) in the Exploratory Studies Facility, using analytical and empirical functions. The analysis of infiltration rates measured at both sites showed three temporal scales of infiltration rate: (1) a macro-scale trend of overall decreasing flow, (2) a meso-scale trend of fast and slow motion exhibiting three-stage variationsmore » of the flow rate (decreasing, increasing, and [again] decreasing flow rate, as observed in soils in the presence of entrapped air), and (3) micro-scale (high frequency) fluctuations. Infiltration tests in the nonwelded unit at Alcove 4 indicate that this unit may effectively dampen episodic fast infiltration events; however, well-known Kostyakov, Horton, and Philip equations do not satisfactorily describe the observed trends of the infiltration rate. Instead, a Weibull distribution model can most accurately describe experimentally determined time trends of the infiltration rate. Infiltration tests in highly permeable, fractured, welded tuff at Alcove 6 indicate that the infiltration rate exhibits pulsation, which may have been caused by multiple threshold effects and water-air redistribution between fractures and matrix. The empirical relationships between the extrinsic seepage from fractures, matrix imbibition, and gravity drainage versus the infiltration rate, as well as scaling and self-similarity for the leading edge of the water front are the hallmark of the nonlinear dynamic processes in water flow under episodic infiltration through fractured tuff. Based on the analysis of experimental data, we propose a conceptual model of a dynamic fracture flow and fracture-matrix interaction in fractured tuff, incorporating the time dependent processes of water redistribution in the fracture-matrix system.« less

Factors of Pelvic Infection and Death in Patients with Open Pelvic Fractures and Rectal Injuries.

PubMed

Song, Wenhao; Zhou, Dongsheng; Xu, Weicheng; Zhang, Guoming; Wang, Chunhui; Qiu, Daodi; Dong, Jinlei

Open pelvic fractures associated with rectal injuries are uncommon. They often cause serious pelvic infection, even death. This combination of injuries has been reviewed infrequently. Herein, we report factors associated with pelvic infection and death in a group of patients with open pelvic fractures and concurrent rectal injuries. We retrospectively reviewed the records of patients with open pelvic fractures and rectal injuries who were treated at our institution from January 2010-April 2014. From the medical records, age, gender, Injury Severity Score (ISS), cause of fracture, associated injuries, classification of the fracture, degree of soft-tissue injury, Glasgow Coma Score (GCS), Revised Trauma Score (RTS), packed red blood cells (PRBCs) needed, presence/absence of shock, early colostomy (yes or no), drainage (yes or no), and rectal washout (yes or no) were extracted. Univariable and multivariable analysis were performed to determine the association between risk factors and pelvic infection or death. Twenty patients were identified. Pelvic infection occurred in 50% (n = 10) of the patients. Four patients suffered septicemia, and three patients died of multiple organ dysfunction. The mortality rate thus was 15%. According to the univariable analysis, the patients in whom pelvic infection developed had shock, RTS ≤8, GCS ≤8, blood transfusion ≥10 units in the first 24 h, no colostomy, or Gustilo grade III soft-tissue injury. According to the multivariable analysis, shock and absence of colostomy were independently associated with pelvic infection. By univariable analysis, the only factor associated with death was RTS ≤8. The incidence of pelvic infection was lower in patients having early colostomy (p < 0.05). Patients with shock had a higher risk of pelvic infection, and we recommend aggressive measures to treat these patients. According to our results, RTS ≤8 could be a predictor of poor outcomes in patients with open pelvic fracture and concurrent rectal injury. Open reduction and internal fixation after extensive debridement is recommended in patients with unstable pelvic fractures.

Cognitive and Psychomotor Entrustable Professional Activities: Can Simulators Help Assess Competency in Trainees?

PubMed

Dwyer, Tim; Wadey, Veronica; Archibald, Douglas; Kraemer, William; Shantz, Jesse Slade; Townley, John; Ogilvie-Harris, Darrell; Petrera, Massimo; Ferguson, Peter; Nousiainen, Markku

2016-04-01

An entrustable professional activity describes a professional task that postgraduate residents must master during their training. The use of simulation to assess performance of entrustable professional activities requires further investigation. (1) Is simulation-based assessment of resident performance of entrustable professional activities reliable? (2) Is there evidence of important differences between Postgraduate Year (PGY)-1 and PGY-4 residents when performing simulated entrustable professional activities? Three entrustable professional activities were chosen from a list of competencies: management of the patient for total knee arthroplasty (TKA); management of the patient with an intertrochanteric hip fracture; and management of the patient with an ankle fracture. Each assessment of entrustable professional activity was 40 minutes long with three components: preoperative management of a patient (history-taking, examination, image interpretation); performance of a technical procedure on a sawbones model; and postoperative management of a patient (postoperative orders, management of complications). Residents were assessed by six faculty members who used checklists based on a modified Delphi technique, an overall global rating scale as well as a previously validated global rating scale for the technical procedure component of each activity. Nine PGY-1 and nine PGY-4 residents participated in our simulated assessment. We assessed reliability by calculating the internal consistency of the mean global rating for each activity as well as the interrater reliability between the faculty assessment and blinded review of videotaped encounters. We sought evidence of a difference in performance between PGY-1 and PGY-4 residents on the overall global rating scale for each station of each entrustable professional activity. The reliability (Cronbach's α) for the hip fracture activity was 0.88, it was 0.89 for the ankle fracture activity, and it was 0.84 for the TKA activity. A strong correlation was seen between blinded observer video review and faculty scores (mean 0.87 [0.07], p < 0.001). For the hip fracture entrustable professional activity, the PGY-4 group had a higher mean global rating scale than the PGY-1 group for preoperative management (3.56 [0.5] versus 2.33 [0.5], p < 0.001), postoperative management (3.67 [0.5] versus 2.22 [0.7], p < 0.001), and technical procedures (3.11 [0.3] versus 3.67 [0.5], p = 0.015). For the TKA activity, the PGY-4 group scored higher for postoperative management (3.5 [0.8] versus 2.67 [0.5], p = 0.016) and technical procedures (3.22 [0.9] versus 2.22 [0.9], p = 0.04) than the PGY-1 group, but no difference for preoperative management with the numbers available (PGY-4, 3.44 [0.7] versus PGY-1 2.89 [0.8], p = 0.14). For the ankle fracture activity, the PGY-4 group scored higher for postoperative management (3.22 [0.8] versus 2.33 [0.7], p = 0.18) and technical procedures (3.22 [1.2] versus 2.0 [0.7], p = 0.018) than the PGY-1 groups, but no difference for preoperative management with the numbers available (PGY-4, 3.22 [0.8] versus PGY-1, 2.78 [0.7], p = 0.23). The results of our study show that simulated assessment of entrustable professional activities may be used to determine the ability of a resident to perform professional tasks that are critical components of medical training. In this manner, educators can ensure that competent performance of these skills in the simulated setting occurs before actual practice with patients in the clinical setting.

[Modified PemberSal osteotomy technique with lyophilized human allograft].

PubMed

Druschel, C; Heck, K; Kraft, C; Placzek, R

2016-12-01

PemberSal osteotomy to improve femoral head coverage by rotating the acetabular roof ventrally and laterally. Insufficient coverage of the femoral head, and can be combined with other surgical procedures such as femoral intertrochanteric varus-derotation osteotomy and open reduction for developmental dysplasia and dislocation of the hip or to improve sphericity and containment in Legg-Calvé-Perthes disease. This specific acetabuloplasty can only be performed in patients with an open epiphyseal growth-plate. Increased bleeding tendency (e.g., inherited or iatrogenic); elevated anesthetic risk such as in cerebral palsy, arthrogryposis multiplex congenital, trisomies; syndromes require explicit interdisciplinary clarification to reduce perioperative risks; infections as in other elective surgeries; diseases/deformities making postoperative spica casting impossible or impractical (e.g., deformities of spinal cord or urogenital system, hernias requiring treatment); closed epiphyseal plate requires complex three-dimensional corrections of the acetabular roof (e.g., triple/periacetabular osteotomy). Osteotomy from the iliac bone to the posterior ilioischial arm of the epiphyseal growth-plate cartilage; controlled fracture of the cancellous bone without breaking the medial cortex of the iliac bone for ventrocaudal rotation of the acetabular roof. To refill and stabilize the osteotomy site, an allogenic bone-wedge is interponated and secured by a resorbable screw or kirschner wire. This method also allows more complex reconstructions of the acetabular roof, e.g., by including the pseudo-cup in a modified Rejholec technique. A spica cast is applied to immobilize the hip for 6 weeks. Afterwards physiotherapy can be performed under weight-bearing as tolerated. Radiographic check-ups every 6 months.

Anterior Z-plate and titanic mesh fixation for acute burst thoracolumbar fracture.

PubMed

Xu, Jian-Guang; Zeng, Bing-Fang; Zhou, Wei; Kong, Wei-Qing; Fu, Yi-Shan; Zhao, Bi-Zeng; Zhang, Tao; Lian, Xiao-Feng

2011-04-01

A retrospective study. To evaluate the clinical outcome, effectiveness, and security of the surgical management of acute thoracolumbar burst fracture with corpectomy, titanic mesh autograft, and Z-plate fixation by anterior approach. Many surgical methods were adopted to treat acute burst thoracolumbar fracture. But the optimal surgical management remains controversial. A retrospective review of a consecutive series of 48 patients with thoracolumbar burst fracture treated with anterior corpectomy, titanic mesh autograft, and Z-plate internal fixation was carried out. Preoperative clinical and radiographic data of all cases were originally collected. Surgical indications were motor neurologic deficit and thoracolumbar column instability. Twenty-two patients (45.8%) with acute thoracolumbar burst fractures presented with a neurologic deficit. The postoperative recovery of neural function, restoration of anterior cortex collapse, kyphotic angle, and spinal canal compromise were observed. The preoperative kyphotic angle was improved to a mean of 5.6°, radiographic height restored to 95.8% of the adjacent normal levels, and canal compromise was 0%. None of the patients had neurologic deterioration. Mean follow-up time was 32.4 months (range, 24-47 months). All 22 patients with neurologic deficit demonstrated at least one Frankel grade improvement on final observation, with 16 (73%) patients had accomplished complete neurologic recovery. Forty-six (96%) patients reported minimal or no pain at final follow-up observation, and 40 (83%) patients who had been working before injury returned to original work. The authors considered spinal cord decompression with anterior corpectomy and stability reconstruction with titanic mesh autograft and Z-plate fixation at same time in one incision as an effective technique for unstable thoracolumbar burst fracture with and without neurologic deficit.

Comparison of modern locked plating and antiglide plating for fixation of osteoporotic distal fibular fractures.

PubMed

Switaj, Paul J; Wetzel, Robert J; Jain, Neel P; Weatherford, Brian M; Ren, Yupeng; Zhang, Li-Qun; Merk, Bradley R

2016-09-01

Fractures in osteoporotic patients can be difficult to treat because of poor bone quality and inability to gain screw purchase. The purpose of this study is to compare modern lateral periarticular distal fibula locked plating to antiglide plating in the setting of an osteoporotic, unstable distal fibula fracture. AO/OTA 44-B2 distal fibula fractures were created in sixteen paired fresh frozen cadaveric ankles and fixed with a lateral locking plate and an independent lag screw or an antiglide plate with a lag screw through the plate. The specimens underwent stiffness, cyclic loading, and load to failure testing. The energy absorbed until failure, torque to failure, construct stiffness, angle at failure, and energy at failure was recorded. The lateral locking construct had a higher torque to failure (p=0.02) and construct stiffness (p=0.04). The locking construct showed a trend toward increased angle at failure, but did not reach statistical significance (p=0.07). Seven of the eight lateral locking plate specimens failed through the distal locking screws, while the antiglide plating construct failed with pullout of the distal screws and displacement of the fracture in six of the eight specimens. In our study, the newly designed distal fibula periarticular locking plate with increased distal fixation is biomechanically stronger than a non-locking one third tubular plate applied in antiglide fashion for the treatment of AO/OTA 44-B2 osteoporotic distal fibula fractures. V: This is an ex-vivo study performed on cadavers and is not a study performed on live patients. Therefore, this is considered Level V evidence. Copyright © 2015. Published by Elsevier Ltd.

Multidirectional volar fixed-angle plating using cancellous locking screws for distal radius fractures--evaluation of three screw configurations in an extra-articular fracture model.

PubMed

Weninger, Patrick; Dall'Ara, Enrico; Drobetz, Herwig; Nemec, Wolfgang; Figl, Markus; Redl, Heinz; Hertz, Harald; Zysset, Philippe

2011-01-01

Volar fixed-angle plating is a popular treatment for unstable distal radius fractures. Despite the availability of plating systems for treating distal radius fractures, little is known about the mechanical properties of multidirectional fixed-angle plates. The aim of this study was to compare the primary fixation stability of three possible screw configurations in a distal extra-articular fracture model using a multidirectional fixed-angle plate with metaphyseal cancellous screws distally. Eighteen Sawbones radii (Sawbones, Sweden, model# 1027) were used to simulate an extra-articular distal radius fracture according to AO/OTA 23 A3. Plates were fixed to the shaft with one non-locking screw in the oval hole and two locking screws as recommended by the manufacturer. Three groups (n = 6) were defined by screw configuration in the distal metaphyseal fragment: Group 1: distal row of screws only; Group 2: 2 rows of screws, parallel insertion; Group 3: 2 rows of screws, proximal screws inserted with 30° of inclination. Specimens underwent mechanical testing under axial compression within the elastic range and load controlled between 20 N and 200 N at a rate of 40 N/s. Axial stiffness and type of construct failure were recorded. There was no difference regarding axial stiffness between the three groups. In every specimen, failure of the Sawbone-implant-construct occurred as plastic bending of the volar titanium plate when the dorsal wedge was closed. Considering the limitations of the study, the recommendation to use two rows of screws or to place screws in the proximal metaphyseal row with inclination cannot be supported by our mechanical data.

Characterization of Unstable Rock Slopes Through Passive Seismic Measurements

NASA Astrophysics Data System (ADS)

Kleinbrod, Ulrike; Burjánek, Jan; Fäh, Donat

2014-05-01

Catastrophic rock slope failures have high social impact, causing significant damage to infrastructure and many casualties throughout the world each year. Both detection and characterization of rock instabilities are therefore of key importance. Analysing unstable rock slopes by means of ambient vibrations might be a new alternative to the already existing methods as for example geotechnical displacement measurements. A systematic measurement campaign has been initiated recently in Switzerland in order to study the seismic response of potential rockslides concerning a broad class of slope failure mechanisms and material conditions. First results are presented in this contribution. Small aperture seismic arrays were deployed at sites of interest for a short period of time (several hours) in order to record ambient vibrations. During each measurement a reference station was installed on a stable part close to the instability. The total number of stations used varies from 16 down to 2, depending on the site scope and resource availability. Instable rock slopes show a highly directional ground motion which is significantly amplified with respect to stable areas. These effects are strongest at certain frequencies which are identified as eigenfrequencies of the unstable rock mass. The eigenfrequencies and predominant directions have been estimated by frequency dependent polarization analysis. Site-to-reference spectral ratios have been calculated as well in order to estimate the relative amplification of ground motion at unstable parts. The retrieved results were compared with independent in-situ observations and other available data. The directions of maximum amplification are in most cases perpendicular to open cracks mapped on the surface and in good agreement with the deformation directions obtained by geodetic measurements. The interpretation of the observed wave field is done through numerical modelling of seismic wave propagation in fractured media with complex topography. For example, a potential relation between eigenfrequencies and unstable rock mass volume is investigated.

Percutaneous Instrumentation of a Complex Lumbar Spine Fracture with Bilateral Pedicle Dissociation: Case Report and Technical Note.

PubMed

Luther, Evan; Urakov, Timur; Vanni, Steven

2018-06-11

 Complex traumatic lumbar spine fractures are difficult to manage and typically occur in younger patients. Surgical immobilization for unstable fractures is an accepted treatment but can lead to future adjacent-level disease. Furthermore, large variations in fracture morphology create significant difficulties when attempting fixation. Therefore, a surgical approach that considers both long-term outcomes and fracture type is of utmost importance. We present a novel technique for percutaneous fixation without interbody or posterolateral fusion in a young patient with bilateral pedicle dissociations and an acute-onset incomplete neurologic deficit.  A 20-year-old man involved in a motorcycle accident presented with unilateral right lower extremity paresis and sensory loss with intact rectal tone and no saddle anesthesia. Lumbar computed tomography (CT) demonstrated L2 and L3 fractures associated with bilateral pedicle dislocations. Lumbar magnetic resonance imaging showed draping of the conus medullaris/cauda equina anteriorly over the kyphotic deformity at L2 with minimal associated canal stenosis at L2 and L3. He was treated with emergent percutaneous fixation of the fracture segment without interbody or posterolateral fusion. Decompression was not performed because of the negligible amount of canal stenosis and high likelihood of cerebrospinal fluid leakage due to dural tears from the fractures. Surgical fixation of the L2 vertebra was achieved by cannulating the left pedicle with an oversized tap while holding the right pedicle in place with a normal tap and then driving screws into the left and right pedicles, respectively, thus reducing the free-floating fracture segment. At 18 months after surgery, a follow-up CT demonstrated good cortication across the prior pedicle fractures, and the instrumentation was removed without any obvious signs of instability or disruption of the alignment at the thoracolumbar junction.  We present a novel technique for percutaneous reduction and fixation of bilateral pedicle fractures with significant dissociation from the vertebral body, associated neural compression from the kyphotic deformity, and minimal spinal canal stenosis. Furthermore, we argue that early fixation and reduction of the fracture prevented irreversible neurologic compromise, and the absence of interbody or posterolateral fusion ultimately preserved the spinal mobility of the patient once the hardware was removed. Georg Thieme Verlag KG Stuttgart · New York.

Post-Injection Induced Seismicity in EGS: Triggering Mechanisms and Mitigation.

NASA Astrophysics Data System (ADS)

De Simone, S.; Carrera, J.; Vilarrasa, V.

2017-12-01

Induced microseismicity is a controversial issue related to Enhanced Geothermal Systems (EGS) and in general with fluid injection into deep geological formations. The occurring of felt earthquakes after stopping injection especially generates concern, because the correlation between injection and seismic activity is unclear. The aim of this work is to advance in the understanding of the processes that may induce or trigger co- and post-injection seismicity. To this end we investigate the thermo-hydro-mechanical coupling by means of numerical simulations of hydraulic stimulation of deep geothermal systems. We find that preferential flow through conductive fractures or fault zones provokes pressure and temperature perturbations that result in not only heterogeneous variation of the stress field, but also highly anisotropic variations of the local stress tensor. Anisotropic variations tend to stabilize some fractures, but destabilize others. Moreover, activation of shear slip causes a significant variation of the stress field that enlarges the range of critical fracture orientations. We find that post-injection seismicity may occur on non-critically oriented faults that were originally stable. During injection, such faults become destabilized by thermal and shear slip stress changes, but remain static by the superposition of the stabilizing effect of pressure forces. However, these fractures become unstable and fail when the pressure forcing dissipates shortly after injection stops abruptly, which suggests that a slow reduction in injection rate may mitigate post-injection seismicity.

Blunt cerebrovascular trauma causing vertebral arteryd issection in combination with a laryngeal fracture: a case report

PubMed Central

2011-01-01

Introduction The diagnosis and therapy of blunt cerebrovascular injuries has become a focus since improved imaging technology allows adequate description of the injury. Although it represents a rare injury the long-term complications can be fatal but mostly prevented by adequate treatment. Case presentation A 33-year-old Caucasian man fell down a 7-meter scarp after losing control of his quad bike in a remote area. Since endotracheal intubation was unsuccessfully attempted due to the severe cervical swelling as well as oral bleeding an emergency tracheotomy was performed on scene. He was hemodynamically unstable despite fluid resuscitation and intravenous therapy with vasopressors and was transported by a helicopter to our trauma center. He had a stable fracture of the arch of the seventh cervical vertebra and fractures of the transverse processes of C5-C7 with involvement of the lateral wall of the transverse foramen. An abort of the left vertebral artery signal at the first thoracic vertebrae with massive hemorrhage as well as a laryngeal fracture was also detected. Further imaging showed retrograde filling of the left vertebral artery at C5 distal of the described abort. After stabilization and reconfirmation of intracranial perfusion during the clinical course weaning was started. At the time of discharge, he was aware and was able to move all extremities. Conclusion We report a rare case of a patient with vertebral artery dissection in combination with a laryngeal fracture after blunt trauma. Thorough diagnostic and frequent reassessments are recommended. Most patients can be managed with conservative treatment. PMID:21843321

Treatment for proximal humeral fractures with percutaneous plating: our first results.

PubMed

Imarisio, D; Trecci, A; Sabatini, L; Scagnelli, R

2013-06-01

Proximal humeral fractures are common lesions; there is no generally accepted strategy about the treatment for displaced and unstable two- to four-part fractures. We have nowadays many different surgical solutions, ranging from percutaneous pinning to shoulder arthroplasty. Percutaneous plating can be a good solution to treat some of these fractures using a minimally invasive technique and performing stable fixation that can allow early mobilization. Purpose of this paper is to evaluate the results of our first cases of percutaneous plating in proximal humeral fractures in order to assess the theoretical advantages and the incidence of possible complications. From June 2009 to February 2012, we treated 29 proximal humeral fractures with a percutaneous plating (NCB-PH plate) through an anterolateral deltoid split. For each patient, we evaluated the clinical outcome according to Constant score and the radiographic results, paying attention to fracture healing, loss of reduction, hardware complications, and head necrosis. The clinical evaluation gave a mean Constant score value of 79 points. Comparing each value to the unaffected shoulder, we could find these results: 7 excellent, 10 good, 8 fair, and 4 poor. No axillary nerve lesions were clinically detected. The radiographic evaluation showed a complete bone healing in all cases within the first 3 months. No head necrosis was detected, as well as screws loosening. In two cases, the X-ray at 2 months revealed a little loss of reduction in varus. Two patients had an anterior pain; in one of these two cases, the plate was removed. In our series, we had no cases of head necrosis, screws cutout, fracture collapse, hardware mobilization, and we think this could be the real advantage of the percutaneous technique compared to the open one, thanks to the reduced biological damage. We had some poor results, related more to patient's age than to other factors. The safety of the technique for the axillary nerve is demonstrated in the literature and confirmed by our experience. Percutaneous plating of proximal humeral fractures with NCB-PH plate has demonstrated to be a good strategy in managing these lesions without increasing complications.

Modelling the graphite fracture mechanisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacquemoud, C.; Marie, S.; Nedelec, M.

2012-07-01

In order to define a design criterion for graphite components, it is important to identify the physical phenomena responsible for the graphite fracture, to include them in a more effective modelling. In a first step, a large panel of experiments have been realised in order to build up an important database; results of tensile tests, 3 and 4 point bending tests on smooth and notched specimens have been analysed and have demonstrated an important geometry related effects on the behavior up to fracture. Then, first simulations with an elastic or an elastoplastic bilinear constitutive law have not made it possiblemore » to simulate the experimental fracture stress variations with the specimen geometry, the fracture mechanisms of the graphite being at the microstructural scale. That is the reason why a specific F.E. model of the graphite structure has been developed in which every graphite grain has been meshed independently, the crack initiation along the basal plane of the particles as well as the crack propagation and coalescence have been modelled too. This specific model has been used to test two different approaches for fracture initiation: a critical stress criterion and two criteria of fracture mechanic type. They are all based on crystallographic considerations as a global critical stress criterion gave unsatisfactory results. The criteria of fracture mechanic type being extremely unstable and unable to represent the graphite global behaviour up to the final collapse, the critical stress criterion has been preferred to predict the results of the large range of available experiments, on both smooth and notched specimens. In so doing, the experimental observations have been correctly simulated: the geometry related effects on the experimental fracture stress dispersion, the specimen volume effects on the macroscopic fracture stress and the crack propagation at a constant stress intensity factor. In addition, the parameters of the criterion have been related to experimental observations: the local crack initiation stress of 8 MPa corresponds to the non-linearity apparition on the global behavior observed experimentally and the the maximal critical stress defined for the particle of 30 MPa is equivalent to the fracture stress of notched specimens. This innovative combination of crack modelling and a local crystallographic critical stress criterion made it possible to understand that cleavage initiation and propagation in the graphite microstructure was driven by a mean critical stress criterion. (authors)« less

Functional outcome following tibio-talar-calcaneal nailing for unstable osteoporotic ankle fractures.

PubMed

Jonas, S C; Young, A F; Curwen, C H; McCann, P A

2013-07-01

Fragility fractures of the ankle are increasing in incidence. Such fractures typically occur from low-energy injuries but lead to disproportionately high levels of morbidity. Ankle fractures in this age group are managed conservatively in plaster or by open reduction and internal fixation. Both modalities have shown high rates of failure in terms of delayed union or mal-union together with perioperative complications such as implant failure and wound breakdown. The optimal treatment of these patients remains controversial. We aimed to review the functional outcome of patients with ankle fragility fractures primarily managed using a tibio-talar-calcaneal nail (TTC). We retrospectively reviewed 31 consecutive patients primarily managed with a TCC nail for osteoporotic fragility fractures about the ankle. Data were collected via case notes, radiographic reviews and by clinical reviews at the outpatient clinic or a telephone follow-up. Information regarding patient characteristics, indication for operation, Arbeitsgemeinschaft für Osteosynthesefragen (AO) fracture classification, operative and postoperative complications, time to radiographic union and current clinical state including Olerud and Molander scores were recorded (as a measure of ankle function). Nine of 31 patients had died by the time of follow-up. Mean preoperative and postoperative Olerud and Molander scores were 56 and 45, respectively. There were no postoperative wound complications. Twenty-nine of 31 patients returned to the same level of mobility as pre-injury. There were three peri-prosthetic fractures managed successfully with nail removal and replacement or plaster cast. There were two nail failures, both in patients who mobilised using only a stick, which were managed by nail removal. Ten of 31 patients were not followed up radiographically due to either infirmity or death. Thirteen of 21 followed up radiographically had evidence of union and 8/21 had none. None, however, had clinical evidence of fracture nonunion. The TTC nail can successfully be used to manage fragility fractures about the ankle in the elderly. Much like fractured neck of femur patients, who also have a high rate of mortality, this allows immediate mobilisation with minimal risk of wound complications. However, careful assessment must be made of each patient's mobility, as there is a significant incidence of device failure in the more active patient. Copyright © 2012 Elsevier Ltd. All rights reserved.

A prospective study of pain reduction and knee dysfunction comparing femoral skeletal traction and splinting in adult trauma patients.

PubMed

Bumpass, David B; Ricci, William M; McAndrew, Christopher M; Gardner, Michael J

2015-02-01

To determine if distal femoral traction pins result in knee dysfunction in patients with femoral or pelvic fracture, and to determine if skeletal traction relieves pain more effectively than splinting for femoral shaft fractures. Prospective cohort trial. Level I urban trauma center. One hundred twenty adult patients with femoral shaft, acetabular, and unstable pelvic fractures. Patients with femoral shaft fractures were placed into distal femoral skeletal traction or a long-leg splint, based on an attending-specific protocol. Patients with pelvic or acetabular fractures with instability or intraarticular bone fragments were placed into skeletal traction. An initial Lysholm knee survey was administered to assess preinjury knee pain and function; the survey was repeated at 3- and 6-month follow-up visits. Also, a 10-point visual analog scale was used to document pain immediately before, during, and immediately after fracture immobilization with traction or splinting. Thirty-five patients (29%) were immobilized with a long-leg splint, and 85 (71%) were immobilized with a distal femoral traction pin. Eighty-four patients (70%) completed a 6-month follow-up. Lysholm scores decreased by a mean 9.3 points from preinjury baseline to 6 months postinjury in the entire cohort (P < 0.01); no significant differences were found between the splint and traction pin groups. During application of immobilization, visual analog scale pain scores were significantly lower in traction patients as compared with splinted patients (mean, 1.9 points less, P < 0.01). Traction pins caused no infections, neurovascular injuries, or iatrogenic fractures. Distal femoral skeletal traction does not result in detectable knee dysfunction at 6 months after insertion, and results in less pain during and after immobilization than long-leg splinting. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

[Treatment of calcaneal fractures with a locking nail (C-Nail)].

PubMed

Pompach, M; Carda, M; Amlang, M; Zwipp, H

2016-06-01

Anatomic reconstruction of the posterior facet by primary stabilization of the calcaneal fracture with a locking nail. All intraarticular calcaneal fractures and unstable two-part fractures independent of the degree of closed/open soft tissue trauma. High perioperative risk, soft tissue infection, beak fracture (type II fracture) and still open apophysis. Anatomic reduction of the posterior facet using a sinus tarsi approach. Reduction and temporary fixation of the sustentacular, tuberosity, and anterior process fragments with 1.8-2.0 mm Kirschner wires. Thereafter, the C-Nail (calcaneus nail) is introduced with its guiding device stabilizing the sustentacular, tuberostity, and anterior process fragments through its three guiding arms with 6 or 7 locking screws. Passive and active motion starts on postoperative day 2. Lymph drains help reduce swelling. Partial weightbearing with 20 kg for 6-8 weeks in the patient's own shoes is recommended. X‑ray controls are done at 4 and 8 weeks as well as after 6 and 12 months. A total of 107 calcaneal fractures treated with the C-Nail between 2011 and 2014 were evaluated according to the AOFAS score 6 months and 1 year after surgery. The measured values were on average 93.0 (range 65-100) points at 6 months and 94.1 (range 75-100) points 12 months after the surgery. Böhler's angle with initial traumatic values of 6.2° (-30 to +13°) improved postoperatively to 31.8°, after 3 months slightly decreased to 29.6°, and after 12 months to 28.3°. There were 2 cases of superficial wound necrosis (1.9 %) and 1 case a deep infection (0.93 %) with need of early C-Nail removal.

Fixation Options for the Volar Lunate Facet Fracture: Thinking Outside the Box.

PubMed

Harness, Neil G

2016-03-01

Background Fractures of the distal radius with small volar ulnar marginal fracture fragments are difficult to stabilize with standard volar locking plates. The purpose of this study is to describe alternative techniques available to stabilize these injuries. Materials and Methods Five patients were identified retrospectively with unstable volar lunate facet fracture fragments treated with supplemental fixation techniques. The demographic data, pre- and postoperative radiographic parameters, and early outcomes data were analyzed. The AO classification, preoperative and final postoperative ulnar variance, articular step-off, volar tilt, radial inclination, and teardrop angle were measured. The lunate subsidence and length of the volar cortex available for fixation were measured from the initial injury films. Description of Technique Lunate facet fixation was based on the morphology of the fragment, and stabilization was achieved with headless compression screws in three patients, a tension band wire construct in one, and two cortical screws in another. Results Five patients with a mean age of 58 years (range: 41-82) were included. There were two AO C3.2 and three B3.3 fractures. Preoperative radiographic measurements including radial inclination, tilt, and ulnar variance all improved after surgery and were maintained within normal limits at 3-month follow-up. There was no change in the teardrop angle at final follow-up (70-64 degrees; p = 0.14). None of the patients had loss of fixation or volar carpal subluxation. The mean visual analog scale pain score at 3 months was 1 (range: 0-2). Conclusions The morphology of volar lunate facet fracture fragments is variable, and fixation must be customized to the particular pattern. Small fragments may preclude the use of plates and screws for fixation. These fractures can be managed successfully with tension band wire constructs and headless screws. These low-profile implants may decrease the risk of tendon irritation that might accompany distally placed plates.

Fixation Options for the Volar Lunate Facet Fracture: Thinking Outside the Box

PubMed Central

Harness, Neil G.

2016-01-01

Background Fractures of the distal radius with small volar ulnar marginal fracture fragments are difficult to stabilize with standard volar locking plates. The purpose of this study is to describe alternative techniques available to stabilize these injuries. Materials and Methods Five patients were identified retrospectively with unstable volar lunate facet fracture fragments treated with supplemental fixation techniques. The demographic data, pre- and postoperative radiographic parameters, and early outcomes data were analyzed. The AO classification, preoperative and final postoperative ulnar variance, articular step-off, volar tilt, radial inclination, and teardrop angle were measured. The lunate subsidence and length of the volar cortex available for fixation were measured from the initial injury films. Description of Technique Lunate facet fixation was based on the morphology of the fragment, and stabilization was achieved with headless compression screws in three patients, a tension band wire construct in one, and two cortical screws in another. Results Five patients with a mean age of 58 years (range: 41–82) were included. There were two AO C3.2 and three B3.3 fractures. Preoperative radiographic measurements including radial inclination, tilt, and ulnar variance all improved after surgery and were maintained within normal limits at 3-month follow-up. There was no change in the teardrop angle at final follow-up (70–64 degrees; p = 0.14). None of the patients had loss of fixation or volar carpal subluxation. The mean visual analog scale pain score at 3 months was 1 (range: 0–2). Conclusions The morphology of volar lunate facet fracture fragments is variable, and fixation must be customized to the particular pattern. Small fragments may preclude the use of plates and screws for fixation. These fractures can be managed successfully with tension band wire constructs and headless screws. These low-profile implants may decrease the risk of tendon irritation that might accompany distally placed plates. PMID:26855830

Anthropometric measurements as predictors of cephalopelvic disproportion: Can the diagnostic accuracy be improved?

PubMed

Benjamin, Santosh J; Daniel, Anjali B; Kamath, Asha; Ramkumar, Vani

2012-01-01

We assessed the efficacy of maternal anthropometric measurements and clinical estimates of fetal weight in isolation and in combination as predictors of cephalopelvic disproportion (CPD). Prospective cohort study. Tertiary care teaching hospital, two affiliated hospitals with facilities for conducting cesarean delivery and seven affiliated primary care facilities with no operation theaters. Primigravidae over 37 weeks' gestation attending these facilities during a 20-month period with a singleton pregnancy in vertex presentation. Several anthropometric measurements were taken in 249 primigravidae. Fetal weight was estimated. Differences in these measurements between the vaginal delivery and CPD groups were analyzed. The validity of these measurements in predicting CPD was analyzed by plotting receiver operating characteristic curves and by logistic regression analysis. Mode of delivery. Maternal height, foot size, inter-trochanteric diameter and bis-acromial diameter showed the highest positive predictive values for CPD. Combining some maternal measurements with estimates of fetal weight increased predictive values modestly, which are likely to be greater if the estimates of fetal weight are close to the actual birth weight. Based on multivariate analysis the risk factors for CPD in our population were foot length ≤23cm, inter-trochanteric diameter ≤30cm and estimated fetal weight ≥3 000g. Maternal anthropometric measurements can predict CPD to some extent. Combining maternal measurements with clinical estimates of fetal weight only enhances the predictive value to a relatively modest degree (positive predictive value 24%). © 2011 The Authors Acta Obstetricia et Gynecologica Scandinavica © 2011 Nordic Federation of Societies of Obstetrics and Gynecology.

A risk-adapted approach is beneficial in the management of bilateral femoral shaft fractures in multiple trauma patients: an analysis based on the trauma registry of the German Trauma Society.

PubMed

Steinhausen, Eva; Lefering, Rolf; Tjardes, Thorsten; Neugebauer, Edmund A M; Bouillon, Bertil; Rixen, Dieter

2014-05-01

Today, there is a trend toward damage-control orthopedics (DCO) in the management of multiple trauma patients with long bone fractures. However, there is no widely accepted concept. A risk-adapted approach seems to result in low acute morbidity and mortality. Multiple trauma patients with bilateral femoral shaft fractures (FSFs) are considered to be more severely injured. The objective of this study was to validate the risk-adapted approach in the management of multiple trauma patients with bilateral FSF. Data analysis is based on the trauma registry of the German Trauma Society (1993-2008, n = 42,248). Multiple trauma patients with bilateral FSF were analyzed in subgroups according to the type of primary operative strategy. Outcome parameters were mortality and major complications as (multiple) organ failure and sepsis. A total of 379 patients with bilateral FSF were divided into four groups as follows: (1) no operation (8.4%), (2) bilateral temporary external fixation (DCO) (50.9%), bilateral primary definitive osteosynthesis (early total care [ETC]) (25.1%), and primary definitive osteosynthesis of one FSF and DCO contralaterally (mixed) (15.6%). Compared with the ETC group, the DCO group was more severely injured. The incidence of (multiple) organ failure and mortality rates were higher in the DCO group but without significance. Adjusted for injury severity, there was no significant difference of mortality rates between DCO and ETC. Injury severity and mortality rates were significantly increased in the no-operation group. The mixed group was similar to the ETC group regarding injury severity and outcome. In Germany, both DCO and ETC are practiced in multiple trauma patients with bilateral FSF so far. The unstable or potentially unstable patient is reasonably treated with DCO. The clearly stable patient is reasonably treated with nailing. When in doubt, the patient is probably not totally stable, and the safest precaution may be to use DCO as a risk-adapted approach. Therapeutic study, level IV. Epidemiologic study, level III.

Magma Fragmentation

NASA Astrophysics Data System (ADS)

Gonnermann, Helge M.

2015-05-01

Magma fragmentation is the breakup of a continuous volume of molten rock into discrete pieces, called pyroclasts. Because magma contains bubbles of compressible magmatic volatiles, decompression of low-viscosity magma leads to rapid expansion. The magma is torn into fragments, as it is stretched into hydrodynamically unstable sheets and filaments. If the magma is highly viscous, resistance to bubble growth will instead lead to excess gas pressure and the magma will deform viscoelastically by fracturing like a glassy solid, resulting in the formation of a violently expanding gas-pyroclast mixture. In either case, fragmentation represents the conversion of potential energy into the surface energy of the newly created fragments and the kinetic energy of the expanding gas-pyroclast mixture. If magma comes into contact with external water, the conversion of thermal energy will vaporize water and quench magma at the melt-water interface, thus creating dynamic stresses that cause fragmentation and the release of kinetic energy. Lastly, shear deformation of highly viscous magma may cause brittle fractures and release seismic energy.

Arthroscopic findings after shoulder dislocation.

PubMed

Hintermann, B; Gächter, A

1995-01-01

The purpose of this study was to evaluate prospectively the arthroscopic findings of the unstable shoulder, to provide insights into the causes and mechanisms of shoulder instability, and to establish a rationale for using special surgical procedures. Arthroscopic examination was performed on 212 patients who had at least 1 documented shoulder dislocation. Of these 212 patients, 184 (87%) patients had anterior glenoid labral tears, 168 (79%) patients had ventral capsule insufficiency, 144 (68%) patients had Hill-Sachs compression fractures, 116 (55%) patients had glenohumeral ligament insufficiency, 30 (14%) patients had complete rotator cuff tendon tears, 26 (12%) patients had posterior glenoid labral tears, 14 (7%) patients had superior labrum anterior and inferior lesions. As this prospective study shows, multiple morphologic changes are associated with instability of the glenohumeral joint; there is no single cause for an unstable shoulder. Arthroscopic examination of the shoulder before surgery revealed a significant amount of information that would have been undetected without the aid of expensive diagnostic tools. For instance, the labrum and rim of the anteroinferior glenoid showed typical abnormalities corresponding to different entities of anterior instability.

Spatial instability of the rift in the St. Paul multifault transform fracture system, Atlantic Ocean

NASA Astrophysics Data System (ADS)

Sokolov, S. Yu.; Zaraiskaya, Yu. A.; Mazarovich, A. O.; Efimov, V. N.; Sokolov, N. S.

2016-05-01

The structure of the acoustic basement of the eastern part of the St. Paul multifault transform fracture system hosts rift paleovalleys and a paleonodal depression that mismatch the position of the currently active zones. This displacement zone, which is composed of five fault troughs, is unstable in terms of the position of the rift segments, which jumped according to redistribution of stresses. The St. Paul system is characterized by straightening of the transform transition between two remote segments of the Mid-Atlantic Ridge (MAR). The eastern part of the system contains anomalous bright-spot-like reflectors on the flattened basement, which is a result of atypical magmatism, that forms the standard ridge relief of the acoustic basement. Deformations of the acoustic basement have a presedimentation character. The present-day deformations with lower amplitude in comparison to the basement are accompanied by acoustic brightening of the sedimentary sequence. The axial Bouguer anomalies in the east of the system continue to the north for 120 km from the active segments of the St. Paul system. Currently seismically active segments of the spreading system are characterized by increasing amplitudes of the E-W displacement along the fault troughs. Cross-correlation of the lengths of the active structural elements of the MAR zone (segments of the ridge and transform fracture zones of displacement) indicates that, statistically, the multifault transform fracture system is a specific type of oceanic strike-slip faults.

The Anterior Intrapelvic Approach for Acetabular Fractures Using Approach-Specific Instruments and an Anatomical-Preshaped 3-Dimensional Suprapectineal Plate.

PubMed

Gras, Florian; Marintschev, Ivan; Grossterlinden, Lars; Rossmann, Markus; Graul, Isabel; Hofmann, Gunther O; Rueger, Johannes M; Lehmann, Wolfgang

2017-07-01

Anatomical acetabular plates the anterior intrapelvic approach (AIP) were recently introduced to fix acetabular fractures through the intrapelvic approach. Therefore, we asked the following: (1) Does the preshaped 3-dimensional suprapectineal plate interfere with or even impair the fracture reduction quality? (2) How often does the AIP approach need to be extended by the first (lateral) window of the ilioinguinal approach? Observational case series. Two Level 1 trauma centers. Patients with unstable acetabular fractures in 2014. Fracture fixation with anatomical-preshaped, 3-dimensional suprapectineal plates through the AIP approach ± the first window of the ilioinguinal approach. Fracture reduction results were measured in computed tomography scans and graded according to the Matta quality of reduction. Intraoperative parameters and perioperative complications were recorded. Radiological results (according to Matta) and functional outcome (modified Merle d'Aubigné score) were evaluated at 1-year follow-up. Thirty patients (9 women + 21 men; mean age ± SE: 64 ± 8 years) were included. The intrapelvic approach was solely used in 19 cases, and in 11 cases, an additional extension with the first window of the ilioinguinal approach (preferential for 2-column fractures) was performed. The mean operating time was 202 ± 59 minutes; the fluoroscopic time was 66 ± 48 seconds. Fracture gaps and steps in preoperative versus postoperative computed tomography scans were 12.4 ± 9.8 versus 2.0 ± 1.5 and 6.0 ± 5.5 versus 1.3 ± 1.7 mm, respectively. At 13.4 ± 2.9 months follow-up, the Matta grading was excellent in 50%, good in 25%, fair in 11%, and poor in 14% of cases. The modified Merle d'Aubigné score was excellent in 17%, good in 37%, fair in 33%, and poor in 13% of cases. The AIP approach using approach-specific instruments and an anatomical-preshaped, 3-dimensional suprapectineal plate became the standard procedure in our departments. Radiological and functional early results justify joint preserving surgery in most cases. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Acute management and outcome of multiple trauma patients with pelvic disruptions

PubMed Central

2012-01-01

Introduction Data on prehospital and trauma-room fluid management of multiple trauma patients with pelvic disruptions are rarely reported. Present trauma algorithms recommend early hemorrhage control and massive fluid resuscitation. By matching the German Pelvic Injury Register (PIR) with the TraumaRegister DGU (TR) for the first time, we attempt to assess the initial fluid management for different Tile/OTA types of pelvic-ring fractures. Special attention was given to the patient's posttraumatic course, particularly intensive care unit (ICU) data and patient outcome. Methods A specific match code was applied to identify certain patients with pelvic disruptions from both PIR and TR anonymous trauma databases, admitted between 2004 and 2009. From the resulting intersection set, a retrospective analysis was done of prehospital and trauma-room data, length of ICU stay, days of ventilation, incidence of multiple organ dysfunction syndrome (MODS), sepsis, and mortality. Results In total, 402 patients were identified. Mean ISS was 25.9 points, and the mean of patients with ISS ≥16 was 85.6%. The fracture distribution was as follows: 19.7% type A, 29.4% type B, 36.6% type C, and 14.3% isolated acetabular and/or sacrum fractures. The type B/C, compared with type A fractures, were related to constantly worse vital signs that necessitated a higher volume of fluid and blood administration in the prehospital and/or the trauma-room setting. This group of B/C fractures were also related to a significantly higher presence of concomitant injuries and related to increased ISS. This was related to increased ventilation and ICU stay, increased rate of MODS, sepsis, and increased rate of mortality, at least for the type C fractures. Approximately 80% of the dead had sustained type B/C fractures. Conclusions The present study confirms the actuality of traditional trauma algorithms with initial massive fluid resuscitation in the recent therapy of multiple trauma patients with pelvic disruptions. Low-volume resuscitation seems not yet to be accepted in practice in managing this special patient entity. Mechanically unstable pelvic-ring fractures type B/C (according to the Tile/OTA classification) form a distinct entity that must be considered notably in future trauma algorithms. PMID:22913820

Improving the toughness of ultrahigh strength steel

NASA Astrophysics Data System (ADS)

Sato, Koji

2002-01-01

The ideal structural steel combines high strength with high fracture toughness. This dissertation discusses the toughening mechanism of the Fe/Co/Ni/Cr/Mo/C steel, AerMet 100, which has the highest toughness/strength combination among all commercial ultrahigh strength steels. The possibility of improving the toughness of this steel was examined by considering several relevant factors. Chapter 1 reviews the mechanical properties of ultrahigh strength steels and the physical metallurgy of AerMet 100. It also describes the fracture mechanisms of steel, i.e. ductile microvoid coalescence, brittle transgranular cleavage, and intergranular separation. Chapter 2 examines the strength-toughness relationship for three heats of AerMet 100. A wide variation of toughness is obtained at the same strength level. The toughness varies despite the fact that all heat fracture in the ductile fracture mode. The difference originates from the inclusion content. Lower inclusion volume fraction and larger inclusion spacing gives rise to a greater void growth factor and subsequently a higher fracture toughness. The fracture toughness value, JIc, is proportional to the particle spacing of the large non-metallic inclusions. Chapter 3 examines the ductile-brittle transition of AerMet 100 and the effect of a higher austenitization temperature, using the Charpy V-notch test. The standard heat treatment condition of AerMet 100 shows a gradual ductile-brittle transition due to its fine effective grain size. Austenitization at higher temperature increases the prior austenite grain size and packet size, leading to a steeper transition at a higher temperature. Both transgranular cleavage and intergranular separation are observed in the brittle fracture mode. Chapter 4 examines the effect of inclusion content, prior austenite grain size, and the amount of austenite on the strength-toughness relationship. The highest toughness is achieved by low inclusion content, small prior austenite grain size, and a small content of stable austenite. The low inclusion content increases the strain at the fracture. The reduction in prior austenite grain size prevents the fast unstable crack propagation by cleavage. And the stable austenite decreases the strength of the intergranular separation at the prior austenite grain boundary, which provides the stress relief at the crack tip.

Efficacy of plain radiography and computer tomography in localizing the site of pelvic arterial bleeding in trauma patients.

PubMed

Dormagen, Johann B; Tötterman, Anna; Røise, Olav; Sandvik, Leiv; Kløw, Nils-E

2010-02-01

Immediate angiography is warranted in pelvic trauma patients with suspected arterial injury (AI) in order to stop ongoing bleeding. Prior to angiography, plain pelvic radiography (PPR) and abdominopelvic computer tomography (CT) are performed to identify fracture and hematoma sites. To investigate if PPR and CT can identify the location of AI in trauma patients undergoing angiography. 95 patients with pelvic fractures on PPR (29 women, 66 men), at a mean age of 44 (9-92) years, underwent pelvic angiography for suspected AI. Fifty-six of them underwent CT additionally. Right and left anterior and posterior fractures on PPR were registered, and fracture displacement was recorded for each quadrant. Arterial blush on CT was registered, and the size of the hematoma in each region was measured in cm(2). AIs were registered for anterior and posterior segments of both internal iliac arteries. Presence of fractures, arterial blush, and hematomas were correlated with AI. Presence of fracture in the corresponding skeletal segment on PPR showed sensitivity and specificity of 0.86 and 0.58 posteriorly, and 0.87 and 0.44 anteriorly. The area under the curve (AUC) was 0.77 and 0.69, respectively. Fracture displacement on PPR >0.9 cm posteriorly and >1.9 cm anteriorly revealed specificity of 0.84. Sensitivities of arterial blush and hematoma on CT were 0.38 and 0.82 posteriorly, and 0.24 and 0.82 anteriorly. The specificities were 0.96 and 0.58 posteriorly, and 0.79 and 0.53 anteriorly, respectively. For hematomas, the AUC was 0.79 posteriorly and 0.75 anteriorly. Size of hematoma >22 cm(2) posteriorly and >29 cm(2) anteriorly revealed specificity of 0.85 and 0.86, respectively. CT findings of arterial blush and hematoma predicted site of arterial bleeding on pelvic angiography. Also, PPR predicted the site of bleeding using location of fracture and size of displacement. In the hemodynamically unstable patient, PPR may contribute equally to effective assessment of injured arteries.

Internal hydrogen-induced subcritical crack growth in austenitic stainless steels

NASA Astrophysics Data System (ADS)

Huang, J. H.; Altstetter, C. J.

1991-11-01

The effects of small amounts of dissolved hydrogen on crack propagation were determined for two austenitic stainless steel alloys, AISI 301 and 310S. In order to have a uniform distribution of hydrogen in the alloys, they were cathodically charged at high temperature in a molten salt electrolyte. Sustained load tests were performed on fatigue precracked specimens in air at 0 ‡C, 25 ‡C, and 50 ‡C with hydrogen contents up to 41 wt ppm. The electrical potential drop method with optical calibration was used to continuously monitor the crack position. Log crack velocity vs stress intensity curves had definite thresholds for subcritical crack growth (SCG), but stage II was not always clearly delineated. In the unstable austenitic steel, AISI 301, the threshold stress intensity decreased with increasing hydrogen content or increasing temperature, but beyond about 10 wt ppm, it became insensitive to hydrogen concentration. At higher concentrations, stage II became less distinct. In the stable stainless steel, subcritical crack growth was observed only for a specimen containing 41 wt ppm hydrogen. Fractographic features were correlated with stress intensity, hydrogen content, and temperature. The fracture mode changed with temperature and hydrogen content. For unstable austenitic steel, low temperature and high hydrogen content favored intergranular fracture while microvoid coalescence dominated at a low hydrogen content. The interpretation of these phenomena is based on the tendency for stress-induced phase transformation, the different hydrogen diffusivity and solubility in ferrite and austenite, and outgassing from the crack tip. After comparing the embrittlement due to internal hydrogen with that in external hydrogen, it is concluded that the critical hydrogen distribution for the onset of subcritical crack growth is reached at a location that is very near the crack tip.

A novel framework for the temporal analysis of bone mineral density in metastatic lesions using CT images of the femur

NASA Astrophysics Data System (ADS)

Knoop, Tom H.; Derikx, Loes C.; Verdonschot, Nico; Slump, Cornelis H.

2015-03-01

In the progressive stages of cancer, metastatic lesions in often develop in the femur. The accompanying pain and risk of fracture dramatically affect the quality of life of the patient. Radiotherapy is often administered as palliative treatment to relieve pain and restore the bone around the lesion. It is thought to affect the bone mineralization of the treated region, but the quantitative relation between radiation dose and femur remineralization remains unclear. A new framework for the longitudinal analysis of CT-scans of patients receiving radiotherapy is presented to investigate this relationship. The implemented framework is capable of automatic calibration of Hounsfield Units to calcium equivalent values and the estimation of a prediction interval per scan. Other features of the framework are temporal registration of femurs using elastix, transformation of arbitrary Regions Of Interests (ROI), and extraction of metrics for analysis. Build in Matlab, the modular approach aids easy adaptation to the pertinent questions in the explorative phase of the research. For validation purposes, an in-vitro model consisting of a human cadaver femur with a milled hole in the intertrochanteric region was used, representing a femur with a metastatic lesion. The hole was incrementally stacked with plates of PMMA bone cement with variable radiopaqueness. Using a Kolmogorov-Smirnov (KS) test, changes in density distribution due to an increase of the calcium concentration could be discriminated. In a 21 cm3 ROI, changes in 8% of the volume from 888 ± 57mg • ml-1 to 1000 ± 80mg • ml-1 could be statistically proven using the proposed framework. In conclusion, the newly developed framework proved to be a useful and flexible tool for the analysis of longitudinal CT data.

J-integral fracture toughness and tearing modulus measurement of radiation cross-linked UHMWPE.

PubMed

Gomoll, A; Wanich, T; Bellare, A

2002-11-01

Radiation and chemical cross-linking of medical grade ultrahigh molecular weight polyethylene (UHMWPE) has recently been utilized in an effort to improve wear performance of total joint replacement components. However, reductions in mechanical properties with cross-linking are cause for concern regarding the use of cross-linked UHMWPE for high-stress applications such as in total knee replacement prostheses. In this study, the fracture behavior of radiation cross-linked UHMWPE was compared to that of uncross-linked UHMWPE. The Rice and Sorensen model that utilizes mechanical parameters obtained from uniaxial tensile and compact tension tests was used to calculate the steady state J-integral fracture toughness, Jss, for radiation cross-linked UHMWPE. Jss decreased monotonically with increase in radiation dose. UHMWPE exhibited tough, ductile tearing behavior with stable crack growth when it was cross-linked using a gamma radiation dose of 0-50 kGy. However, in cross-linked UHMWPE irradiated to a dose of 100 and 200 kGy, unstable fracture occurred spontaneously upon attaining the initial crack driving force, J1c. This indicates that a high degree of cross-linking is less desirable for high-stress applications in orthopaedic implants. However, a substantial increase in J1c, even at a low degree of cross-linking, suggests that a low degree of cross-linking may be beneficial for resistance to delamination and catastrophic failure, both of which require an initiation step for the fracture to propagate in the material. This mechanical test should, however, be considered along with fatigue tests and joint simulator testing before determination of an appropriate amount of cross-linking for total joint replacement prostheses that experience high stresses.

Volar fixed-angle plating of extra-articular distal radius fractures--a biomechanical analysis comparing threaded screws and smooth pegs.

PubMed

Weninger, Patrick; Dall'Ara, Enrico; Leixnering, Martin; Pezzei, Christoph; Hertz, Harald; Drobetz, Herwig; Redl, Heinz; Zysset, Philippe

2010-11-01

Distal radius fractures represent the most common fractures in adult individuals. Volar fixed-angle plating has become a popular modality for treating unstable distal radius fractures. Most of the plates allow insertion of either threaded locking screws or smooth locking pegs. To date, no biomechanical studies compare locking screws and pegs under axial and torsional loading. Ten Sawbones radii were used to simulate an AO/OTA A3 fracture. Volar fixed-angle plates (Aptus Radius 2.5, Medartis, Switzerland) with threaded locking screws (n = 5) or smooth locking pegs (n = 5) were used to fix the distal metaphyseal fragment. Each specimen was tested under axial compression and under torsional load with a servohydraulic testing machine. Qualitative parameters were recorded as well as axial and torsional stiffness, torsion strength, energy absorbed during monotonic loading and energy absorbed in one cycle. Axial stiffness was comparable between both groups (p = 0.818). If smooth pegs were used, a 17% reduction of torsional stiffness (p = 0.017) and a 12% reduction of minimum torque (p = 0.012) were recorded. A 12% reduction of energy absorbed (p = 0.013) during monotonic loading and unloading was recorded if smooth pegs were used. A 34% reduction of energy absorbed in one cycle (p < 0.007) was recorded if threaded screws were used. Sliding of the pegs out of the distal radius metaphyses of the synthetic bones was recorded at a mean torque of 3.80 Nm ± 0.19 Nm. No sliding was recorded if threaded screws were used. According to the results of this study using Sawbones, volar fixed-angle plates with threaded locking screws alone are mechanically superior to volar fixed-angle plates with smooth locking pegs alone under torsional loading.

Three-dimensional to two-dimensional transition in mode-I fracture microbranching in a perturbed hexagonal close-packed lattice

NASA Astrophysics Data System (ADS)

Heizler, Shay I.; Kessler, David A.

2017-06-01

Mode-I fracture exhibits microbranching in the high velocity regime where the simple straight crack is unstable. For velocities below the instability, classic modeling using linear elasticity is valid. However, showing the existence of the instability and calculating the dynamics postinstability within the linear elastic framework is difficult and controversial. The experimental results give several indications that the microbranching phenomenon is basically a three-dimensional (3D) phenomenon. Nevertheless, the theoretical effort has been focused mostly on two-dimensional (2D) modeling. In this paper we study the microbranching instability using three-dimensional atomistic simulations, exploring the difference between the 2D and the 3D models. We find that the basic 3D fracture pattern shares similar behavior with the 2D case. Nevertheless, we exhibit a clear 3D-2D transition as the crack velocity increases, whereas as long as the microbranches are sufficiently small, the behavior is pure 3D behavior, whereas at large driving, as the size of the microbranches increases, more 2D-like behavior is exhibited. In addition, in 3D simulations, the quantitative features of the microbranches, separating the regimes of steady-state cracks (mirror) and postinstability (mist-hackle) are reproduced clearly, consistent with the experimental findings.

Evaluation of the quality of life of patients undergoing hemiarthroplasty of the hip☆

PubMed Central

de Abreu, Eduardo Lima; de Oliveira, Medre Henrique Araújo

2015-01-01

Objective This was a comparative analysis on the quality of life of patients who underwent hemiarthroplasty of the hip, assessed before the operation and 3 and 6 months after the operation, by means of the SF-36 questionnaire (Medical Outcomes Study 36-Item Short Form health survey). Methods A prospective study was conducted on 12 patients with femoral neck fractures who underwent partial hip arthroplasty between June 2013 and July 2014. Female patients predominated (58.3%). The mean age was 83 years and, in 91.7%, the fracture was due to falling from a standing position. The SF-36 questionnaire was applied before the operation and 3 and 6 months after the operation. Results With regard to physical health, the patients presented low scores for functional capacity and physical aspects. They had good scores for the subitem of general state and high scores regarding pain. Vitality, social aspect and mental health had moderate scores and emotional aspects had a low score. Conclusion With the sample analyzed here, we can say that the hip hemiarthroplasty procedure for cases of unstable femoral neck fractures, in patients with low functional demands analyzed over a postoperative period of 6 months, does indeed allow quality of life to be maintained. PMID:26535198

Early or delayed stabilization in severely injured patients with spinal fractures? Current surgical objectivity according to the Trauma Registry of DGU: treatment of spine injuries in polytrauma patients.

PubMed

Bliemel, Christopher; Lefering, Rolf; Buecking, Benjamin; Frink, Michael; Struewer, Johannes; Krueger, Antonio; Ruchholtz, Steffen; Frangen, Thomas Manfred

2014-02-01

Because of a lack of evidence, the appropriate timing of surgical stabilization of thoracic and lumbar spine injuries in severely injured patients is still controversial. Data of a large international trauma register were analyzed to investigate the medical care situation of unstable spinal column fractures in patients with multiple injuries, so as to examine the outcome related to timing of surgical stabilization. Data sets of the Trauma Registry of German Trauma Society (Deutsche Gesellschaft für Unfallchirurgie [DGU]) (1993-2010) were analyzed. The Trauma Registry of DGU is a prospective, multicenter register that provides information on severely injured patients. All patients with an Injury Severity Score (ISS) of 16 or greater caused by blunt trauma, subsequent treatment of 7 days or more, 16 years or older, and thoracic or lumbar spine injuries (spine Abbreviated Injury Scale [AIS] score ≥ 2) were included in our analysis. Patients with relevant spine injuries classified as having a spine AIS score of 3 or greater were further analyzed in terms of whether they got early (<72 hours) or late (>72 hours) surgical treatment due to unstable spinal column fractures. Of 24,974 patients, 8,994 (36.0%) had documented spinal injuries (spine AIS score ≥ 2). A total of 1,309 patients who sustained relevant thoracic spine injuries (spine AIS score ≥ 3) and 994 patients who experienced lumbar spine trauma and classified as having spine AIS score of 3 or greater were more precisely analyzed. Of these, 68.2% and 71.0%, respectively, received an early thoracic or lumbar spine fixation. With an increase in spinal injury severity, an increase in early stabilization in the thoracic and lumbar spine was seen. In the group of patients with early surgical stabilization, significantly shorter hospital stays, shorter intensive care unit stays, fewer days on mechanical ventilation, and lower rates of sepsis were seen. In the case that additional body regions were affected, for example, when patients were critically ill, a delayed spinal stabilization was more often performed. A spinal stabilization at an early stage (<72 hours) is presumed to be beneficial. Although some patients may require delay due to necessary medical improvement, every reasonable effort should be made to treat patients with instable spinal column fractures as soon as possible. If an early surgical treatment is feasible, severely injured patients may benefit from a shorter period of hospital treatment and a lower rate of complications. Therapeutic study, level III.

Fatigue strength of common tibial intramedullary nail distal locking screws

PubMed Central

Griffin, Lanny V; Harris, Robert M; Zubak, Joseph J

2009-01-01

Background Premature failure of either the nail and/or locking screws with unstable fracture patterns may lead to angulation, shortening, malunion, and IM nail migration. Up to thirty percent of all unreamed nail locking screws can break after initial weight bearing is allowed at 8–10 weeks if union has not occurred. The primary problem this presents is hardware removal during revision surgery. The purposes of our study was to evaluate the relative fatigue resistance of distal locking screws and bolts from representative manufacturers of tibial IM nail systems, and develop a relative risk assessment of screws and materials used. Evaluations included quantitative and qualitative measures of the relative performance of these screws. Methods Fatigue tests were conducted to simulate a comminuted fracture that was treated by IM nailing assuming that all load was carried by the screws. Each screw type was tested ten times in a single screw configuration. One screw type was tested an additional ten times in a two-screw parallel configuration. Fatigue tests were performed using a servohydraulic materials testing system and custom fixturing that simulated screws placed in the distal region of an appropriately sized tibial IM nail. Fatigue loads were estimated based on a seventy-five kilogram individual at full weight bearing. The test duration was one million cycles (roughly one year), or screw fracture, whichever occurred first. Failure analysis of a representative sample of titanium alloy and stainless steel screws included scanning electron microscopy (SEM) and quantitative metallography. Results The average fatigue life of a single screw with a diameter of 4.0 mm was 1200 cycles, which would correspond roughly to half a day of full weight bearing. Single screws with a diameter of 4.5 mm or larger have approximately a 50 percent probability of withstanding a week of weight bearing, whereas a single 5.0 mm diameter screw has greater than 90 percent probability of withstanding more than a week of weight bearing. If two small diameter screws are used, our tests showed that the probability of withstanding a week of weight bearing increases from zero to about 20 percent, which is similar to having a single 4.5 mm diameter screw providing fixation. Conclusion Our results show that selecting the system that uses the largest distal locking screws would offer the best fatigue resistance for an unstable fracture pattern subjected to full weight bearing. Furthermore, using multiple screws will substantially reduce the risk of premature hardware failure. PMID:19371438

Health Care Usage and Related Costs in Fibular Plating for AO Type 44-B Ankle Fractures in a Belgian University Hospital: An Exploratory Analysis.

PubMed

Smeets, Bart; Nijs, Stefaan; Nderlita, Meri; Vandoren, Cindy; Hoekstra, Harm

2016-01-01

Open reposition and internal fixation (ORIF) is the reference standard for unstable Arbeitsgemeinschaft für Osteosynthesefragen (AO)-type 44-B ankle fractures. Age, comorbidity, delayed-staged surgery, and length-of-stay (LOS) are all factors that presumably correlate positively with health care costs. We performed an exploratory analysis of the health care costs associated with the treatment of this type of fracture and hypothesized that these costs will be significantly greater for the elderly. A total of 217 patients with an acute AO type 44-B ankle fracture were included. We studied 14 variables, and 5 main cost categories were defined. The health care costs associated with the treatment of ankle fractures in the present study constituted more than one half (53%) of the hospitalization costs, which, in turn, were strongly related to the LOS. Delayed-staged surgery and age were the most important clinical variables driving the total health care costs and LOS (p < .001). The median LOS before ORIF was 6 times greater (12 versus 2 days) for patients treated using a delayed-staged surgery protocol. The cutoff age above which the costs differed significantly was 65 years. Thus, the median total health care costs for the treatment of these fractures were doubled in the older group ($9207 versus $4559), mainly owing to a 2 times greater LOS before ORIF (2 versus 4 days) and 3 times greater total LOS (4 versus 12.5 days) in the elderly. Surprisingly, the complication rate was equal (27.7% versus 29.3%) in the 2 groups. Therefore, to decrease the total health care costs, we should focus on a reduction of the costly LOS before ORIF in the elderly population. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Cost-Utility Analysis of Pedicle Screw Removal After Successful Posterior Instrumented Fusion in Thoracolumbar Burst Fractures.

PubMed

Lee, Han-Dong; Jeon, Chang-Hoon; Chung, Nam-Su; Seo, Young-Wook

2017-08-01

A cost-utility analysis (CUA). The aim of this study was to determine the cost-effectiveness of pedicle screw removal after posterior fusion in thoracolumbar burst fractures. Pedicle screw instrumentation is a standard fixation method for unstable thoracolumbar burst fracture. However, removal of the pedicle screw after successful fusion remains controversial because the clinical benefits remain unclear. CUA can help clinicians make appropriate decisions about optimal health care for pedicle screw removal after successful fusion in thoracolumbar burst fractures. We conducted a single-center, retrospective, longitudinal matched-cohort study of prospectively collected outcomes. In total, 88 consecutive patients who had undergone pedicle screw instrumentation for thoracolumbar burst fracture with successful fusion confirmed by computed tomography (CT) were used in this study. In total, 45 patients wanted to undergo implant removal surgery (R group), and 43 decided not to remove the implant (NR group). A CUA was conducted from the health care perspective. The direct costs of health care were obtained from the medical bill of each patient. Changes in health-related quality of life (HRQoL) scores, validated by Short Form 6D, were used to calculate quality-adjusted life-years (QALYs). Total costs and gained QALY were calculated at 1 year (1 year) and 2 years (2 years) compared with baseline. Results are expressed as an incremental cost-effectiveness ratio (ICER). Different discount rates (0%, 3%, and 5%) were applied to both cost and QALY for sensitivity analysis. Baseline patient variables were similar between the two groups (all P > 0.05). The additional benefits of implant removal (0.201 QALY at 2 years) were achieved with additional costs ($2541 at 2 years), equating to an ICER of $12,641/QALY. On the basis of the different discount rates, the robustness of our study's results was also determined. Implant removal after successful fusion in a thoracolumbar burst fracture is cost-effective until postoperative year 2. 3.

Treatment of unstable distal radius fractures: non-invasive dynamic external fixator versus volar locking plate – functional and radiological outcome in a prospective case-controlled series

PubMed Central

Bajwa, Ali S.; Rammappa, Manju; Lee, Ling; Nanda, Rajesh

2015-01-01

Introduction: Distal radius fracture (DRF) is a common injury and various treatment modalities including open reduction and internal fixation (ORIF) with volar locking plate are available. More recently, a non-invasive external fixator has been used. Aims: To prospectively compare the use of a non-invasive external fixator with early dynamisation for DRF against ORIF with volar locking plate control group. Methods: Consecutive patients with closed DRF were included in a prospective case-controlled study. Patients were assigned to non-invasive external fixator or ORIF. Minimum follow-up was two years. Follow-up was at weeks 2, 4, 6, 8, 12, 26 and at one and two-year post-operatively. The outcome measures included demographic details, injury mechanism, AO fracture type, risk factors, body mass index (BMI), ulnar styloid fracture and dorsal comminution, radiographs, grip strength and DASH score. Results: Consecutive 50 patients were treated either with non-invasive external fixator (25/50) or with ORIF (25/50) and the mean age of the two groups was 53 years (SD 17.1) and 49 years (SD 19.5), respectively. Demographics were matched in two groups. In the non-invasive external fixator group, there were 10 AO Type-A, 5 Type-B and 10 Type-C fractures. The ORIF group included 8 Type-A, 6 Type-B and 11 Type-C fractures. The mean DASH score at three-months and one-year post-injury in non-invasive fixator group was 12.2 (SD 3.1) and 3.5 (SD 0.7), respectively, significantly greater than those of ORIF group 14.5 (SD 5.6) and 11.2 (SD 4.4), respectively (p < 0.05). Conclusion: DRF treated with non-invasive external fixator can give functional results superior to ORIF at three-months and the trend is maintained at one and two-year post-operatively. PMID:27163089

Ambient Seismic Imaging of Hydraulically Active Fractures at km Depths

NASA Astrophysics Data System (ADS)

Malin, P. E.; Sicking, C.

2017-12-01

Streaming Depth Images of ambient seismic signals using numerous, densely-distributed, receivers have revealed their connection to hydraulically active fractures at 0.5 to 5 km depths. Key for this type of imaging is very high-fold stacking over both multiple receives and periods of a few hours. Also important is suppression of waveforms from fixed, repeating sources such as pumps, generators, and traffic. A typical surface-based ambient SDI survey would use a 3D seismic receiver grid. It would have 1,000 to 4,000 uniformly distributed receivers at a density of 50/km2over the target. If acquired by borehole receivers buried 100 m deep, the density can be dropped by an order of magnitude. We show examples of the acquisition and signal processing scenarios used to produce the ambient images. (Sicking et al., SEG Interpretation, Nov 2017.) While the fracture-fluid source connection of SDI has been verified by drilling and various types of hydraulic tests, the precise nature of the signal's origin is not clear. At the current level of observation, the signals do not have identifiable phases, but can be focused using P wave velocities. Suggested sources are resonances of pressures fluctuations in the fractures, or small, continuous, slips on fractures surfaces. In either case, it appears that the driving mechanism is tectonic strain in an inherently unstable crust. Solid earth tides may enhance these strains. We illustrate the value of the ambient SDI method in its industrial application by showing case histories from energy industry and carbon-capture-sequestration projects. These include ambient images taken before, during, and after hydraulic treatments in un-conventional reservoirs. The results show not only locations of active fractures, but also their time responses to stimulation and production. Time-lapse ambient imaging can forecast and track events such as well interferences and production changes that can result from nearby treatments.

Postoperative stroke after hemiarthroplasty for femoral neck fracture: a report of 2 cases and review of literature.

PubMed

Ding, David Yi; Christoforou, Dimitrios; Turner, Garth; Tejwani, Nirmal C

2014-06-01

Femoral neck fractures in the elderly comprise a significant number of orthopedic surgical cases at a major trauma center. These patients are immediately incapacitated, and surgical fixation can help increase mobility, restore independence, and reduce morbidity and mortality. However, operative treatment carries its own inherent risks including infections, deep vein thromboses, and intraoperative cardiovascular collapse. Cerebrovascular stroke is a relatively uncommon occurrence after hip fractures. We present 2 cases with unusual postoperative medical complication after cemented hip hemiarthroplasty for femoral neck fracture that will serve to illustrate an infrequent but very serious complication. Case 1 was a 73-year-old man with a Garden IV femoral neck fracture who underwent a right hip unipolar cemented hemiarthroplasty under general anesthesia. After uneventful surgery, he developed neurological deficits, and a postoperative noncontrast head computed tomography showed a right medial thalamic infarct. Case 2 was an 82-year-old man with a Garden IV femoral neck fracture who underwent a right hip unipolar cemented hemiarthroplasty under general anesthesia. After uneventful surgery, the patient became hemodynamically unstable. A postoperative noncontrast head computed tomography showed a large evolving left middle cerebral artery stroke. General anesthesia in the setting of decreased cardiac function (decreased ejection fraction and output) carries the risk for ischemic injury to the brain from decreased cerebral perfusion. Risk factors including advanced age, history of coronary artery disease, atherosclerotic disease, and atrial fibrillation increase the risk for perioperative stroke. Furthermore, it is known that during the cementing of implants, microemboli can be released, which must be considered in patients with preoperative heart disease. As a result, consideration of using a noncemented implant or cementing without pressurizing in this clinical scenario should be an important aspect of the preoperative plan in an at-risk patient. Further studies are needed that can elucidate a causal relationship.

Effects of unipedal standing balance exercise on the prevention of falls and hip fracture among clinically defined high-risk elderly individuals: a randomized controlled trial.

PubMed

Sakamoto, Keizo; Nakamura, Toshitaka; Hagino, Hiroshi; Endo, Naoto; Mori, Satoshi; Muto, Yoshiteru; Harada, Atsushi; Nakano, Tetsuo; Itoi, Eiji; Yoshimura, Mitsuo; Norimatsu, Hiromichi; Yamamoto, Hiroshi; Ochi, Takahiro

2006-10-01

The aim of this study was to assess the effectiveness of the unipedal standing balance exercise for 1 min to prevent falls and hip fractures in high-risk elderly individuals with a randomized controlled trial. This control study was designed as a 6-month intervention trial. Subjects included 553 clinically defined high-risk adults who were living in residences or in the community. They were randomized to an exercise group and a control group. Randomization to the subjects was performed by a table of random numbers. A unipedal standing balance exercise with open eyes was performed by standing on each leg for 1 min three times per day. As a rule, subjects of the exercise group stood on one leg without holding onto any support, but unstable subjects were permitted to hold onto a bar during the exercise time. Falls and hip fractures were reported by nurses, physical therapists, or facility staff with a survey sheet every month. This survey sheet was required every month for both groups. Registered subjects were 553 persons ranging in age from 37 to 102 years (average, 81.6 years of age). Twenty-six subjects dropped out. The number of falls and hip fractures for the 6-month period after the trial for 527 of the 553 subjects for whom related data were available were assessed. The exercise group comprised 315 subjects and the control group included 212 subjects. The cumulative number of falls of the exercise group, with 1 multiple faller omitted, was 118, and the control group recorded 121 falls. A significant intergroup difference was observed. However, the cumulative number of hip fractures was only 1 case in both groups. This difference was not statistically significant. The unipedal standing balance exercise is effective to prevent falls but was not shown to be statistically significant in the prevention of hip fracture in this study.

Rock melting tool with annealer section

DOEpatents

Bussod, Gilles Y.; Dick, Aaron J.; Cort, George E.

1998-01-01

A rock melting penetrator is provided with an afterbody that rapidly cools a molten geological structure formed around the melting tip of the penetrator to the glass transition temperature for the surrounding molten glass-like material. An annealing afterbody then cools the glass slowly from the glass transition temperature through the annealing temperature range to form a solid self-supporting glass casing. This allows thermally induced strains to relax by viscous deformations as the molten glass cools and prevents fracturing of the resulting glass liner. The quality of the glass lining is improved, along with its ability to provide a rigid impermeable casing in unstable rock formations.

[Mathematical calculation of strength of the vertebral column in surgical treatment of unstable fractures of the spine].

PubMed

Orlov, S V; Kanykin, A Iu; Moskalev, V P; Shchedrenok, V V; Sedov, R L

2009-01-01

A mathematical model of a three-vertebra complex was developed in order to make an exact calculation of loss of supporting ability of the vertebral column in trauma. Mathematical description of the dynamic processes was based on Lagrange differential equation of the second order. The degree of compression and instability of the three-vertebra complex, established using mathematical modeling, determines the decision on the surgical treatment and might be considered as a prognostic criterion of the course of the compression trauma of the spine. The method of mathematical modeling of supporting ability of the vertebral column was used in 72 patients.

Clathrate hydrates in cometary nuclei and porosity

NASA Technical Reports Server (NTRS)

Smoluchowski, R.

1988-01-01

Possible mechanisms of formation and decomposition of CO2-clathrate hydrate in cometary nuclei are discussed. As far as it is known, this is the only clathrate hydrate which is unstable at low temperatures. Calculation shows that, in accord with other evidence, neither volume nor grain boundary diffusion in the clathrate lattice can be responsible for the rate of these reactions and that a surface mechanism with the attendant sensitivity to pressure must play a crucial role. Density changes accompanying CO2-clathrate decomposition and formation can lead to microporosity and enhanced brittleness or even to fracture of cometary nuclei at low temperatures. Other clathrate hydrates and mixed clathrates are also discussed.

Large Deformation Analysis of a High Steep Slope Relating to the Laxiwa Reservoir, China

NASA Astrophysics Data System (ADS)

Lin, Peng; Liu, Xiaoli; Hu, Senying; Li, Pujian

2016-06-01

The unstable rock slope in the Laxiwa reservoir area of the Yellow River upstream, China, shows the signs of gravitational and water-impounding induced large deformations over an area of 1.15 × 105 m2. Slope movements have been measured daily at more than 560 observation points since 2009, when the reservoir was first impounded. At two of these points, an average daily movement of around 60-80 mm has ever been observed since the beginning of the impounding. Based on the observed deformations and the geology of the site, a fluid-solid coupling model was then adopted to investigate the existing rockslide activity to better understand the mechanism underlying the large deformations. The results from the field observation, kinematic analysis and numerical modeling indicate that the slope instability is dominated by the strong structurally controlled unstable rock mass. Based on an integrated overview of these analyses, a new toppling mode, i.e. the so-called `conjugate block' mode, is proposed to explain the large deformation mechanism of the slope. The conjugate block is formed by a `dumping block' and toppling blocks. The large deformation of the slope is dominated by (1) a toppling component and (2) a subsiding bilinear wedge induced by planar sliding along the deep-seated faults. Following a thorough numerical analysis, it is concluded that small collapses of rock blocks along the slope will be more frequent with the impounding process continuing and the water level fluctuating during the subsequent operation period. Based on a shear strength reduction method and field monitoring, four controlling faults are identified and the instability of the loose structure in the surface layer is analyzed and discussed. The factor of safety against the sliding failure along the deep seated fractures in the slope is 1.72, which reveals that (1) the collapse of the free-standing fractured blocks cannot be ruled out and the volume of the unstable blocks may be greater than 100,000 m3; (2) the collapse of the whole slope, i.e. with the volume being greater than 92 million m3, or a very large collapse involving several million m3, is considered to be of very low likelihood, unless there are extreme conditions, such as earthquakes and exceptionally heavy rain.

Korean Type Distal Radius Anatomical Volar Plate System: A Preliminary Report

PubMed Central

Kim, Jeong Hwan; Kim, Jihyeung; Kim, Min Bom; Rhee, Seung Hwan; Gong, Hyun Sik; Lee, Young Ho

2014-01-01

Background Distal radius fracture is the most common fracture of the upper extremity, and approximately 60,000 distal radius fractures occur annually in Korea. Internal fixation with an anatomical volar locking plate is widely used in the treatment of unstable distal radius fractures. However, most of the currently used distal radius anatomical plate systems were designed based on the anatomical characteristics of Western populations. Recently, the Korean-type distal radius anatomical volar plate (K-DRAVP) system was designed and developed based on the anatomical characteristics of the distal radius of Koreans. The purpose of this study was to evaluate the preliminary results of the new K-DRAVP system, and to compare its radiologic and functional results with those of the other systems. Methods From March 2012 to October 2012, 46 patients with acute distal radius fractures who were treated with the K-DRAVP system at three hospitals were enrolled in this study. Standard posteroanterior and lateral radiographs were obtained to assess fracture healing, and three radiographic parameters (volar tilt, radial inclination, and radial length) were assessed to evaluate radiographic outcomes. The range of motion and grip strength, the Gartland and Werley scoring system, and the disabilities of the arm, shoulder and hand (DASH) questionnaire were used to assess clinical and functional outcomes. Results All radiologic parameters were restored to normal values, and maintained without any loosening or collapse until the time of final follow-up. Grip strength was restored to 84% of the value for the unaffected side. The mean range of motion of the wrist at final follow-up was restored to 77%-95% of the value for the unaffected side. According to the Gartland and Werley scoring system, there were 16 excellent, 26 good, and 4 fair results. The mean DASH score was 8.4 points. There were no complications after surgery. Conclusions The newly developed K-DRAVP system could be used to restore and maintain good anatomical parameters, and provide good clinical outcomes with low complication rates. This system is a promising surgical option for the treatment of distal radius fractures in the Korean population. PMID:25177449

Accelerated rehabilitation compared with a standard protocol after distal radial fractures treated with volar open reduction and internal fixation: a prospective, randomized, controlled study.

PubMed

Brehmer, Jess L; Husband, Jeffrey B

2014-10-01

There are relatively few studies in the literature that specifically evaluate accelerated rehabilitation protocols for distal radial fractures treated with open reduction and internal fixation (ORIF). The purpose of this study was to compare the early postoperative outcomes (at zero to twelve weeks postoperatively) of patients enrolled in an accelerated rehabilitation protocol with those of patients enrolled in a standard rehabilitation protocol following ORIF for a distal radial fracture. We hypothesized that patients with accelerated rehabilitation after volar ORIF for a distal radial fracture would have an earlier return to function compared with patients who followed a standard protocol. From November 2007 to November 2010, eighty-one patients with an unstable distal radial fracture were prospectively randomized to follow either an accelerated or a standard rehabilitation protocol after undergoing ORIF with a volar plate for a distal radial fracture. Both groups began with gentle active range of motion at three to five days postoperatively. At two weeks, the accelerated group initiated wrist/forearm passive range of motion and strengthening exercises, whereas the standard group initiated passive range of motion and strengthening at six weeks postoperatively. Patients were assessed at three to five days, two weeks, three weeks, four weeks, six weeks, eight weeks, twelve weeks, and six months postoperatively. Outcomes included Disabilities of the Arm, Shoulder and Hand (DASH) scores (primary outcome) and measurements of wrist flexion/extension, supination, pronation, grip strength, and palmar pinch. The patients in the accelerated group had better mobility, strength, and DASH scores at the early postoperative time points (zero to eight weeks postoperatively) compared with the patients in the standard rehabilitation group. The difference between the groups was both clinically relevant and statistically significant. Patients who follow an accelerated rehabilitation protocol that emphasizes motion immediately postoperatively and initiates strengthening at two weeks after volar ORIF of a distal radial fracture have an earlier return to function than patients who follow a more standard rehabilitation protocol. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Anterior-only stabilization using cage versus plating with bone autograft for the treatment of type II/IIA Hangman's fracture combined with intervertebral disc injury.

PubMed

Wei, Fuxin; Pan, Ximin; Zhou, Zhiyu; Cui, Shangbin; Zhong, Rui; Wang, Le; Gao, Manman; Chen, Ningning; Liang, Zijian; Zou, Xuenong; Huang, Sheng; Liu, Shaoyu

2015-03-11

Anterior C2/3 discectomy and interbody fusion (ACDF) with plating is increasingly performed as the primary treatment of unstable Hangman's fracture; however, plate-related complications, such as screw back-out, plate fracture and soft-tissue injury, is not uncommon. Polyetheretherketone (PEEK) cage has now been developed to provide initial stability before fusion; however, whether and how ACDF with PEEK cage offer better clinical results compared with ACDF with plating in management of Hangman's fracture remains unknown. This study compares the efficacy of ACDF with plating to that of ACDF with PEEK cage in management of type II/IIA Hangman's fractures (according to Levine and Edwards classification) retrospectively. From February 2006 to March 2012, a total of 21 patients with type II/IIA Hangman's fractures combined with intervertebral disc injury underwent ACDF with PEEK cage, and 28 patients underwent ACDF with plating. Perioperative parameters were compared. The average follow-up period was 50.3 months (range 27-76 months). The clinical outcome (visual analog scale (VAS), American Spinal Injury Association (ASIA) scale, and clinical post-traumatic neck score (PTNC)) and radiological outcome (translation of C2, local kyphotic angle (LKA), and fusion status of C2/3) was compared retrospectively. The operative time and blood loss were significantly less in the ACDF with cage group compared with that in the ACDF with plating group (P < 0.05). All patients showed neurological recovery and achieved solid fusion. There were no significant differences in the clinical and radiological outcomes at final follow-up between groups, except in the LKA and the correction loss rate of LKA which were higher in the ACDF with plating group (P < 0.05). Donor-site pain occurred in two patients (10.1%) within 6 months after operation in the ACDF with plating group and none in the ACDF with cage group. All patients recovered without any adverse effects. ACDF with PEEK cage is effective and reliable in management of type II/IIA Hangman's fractures and is more cost-effective due to shorter operative time and less blood loss requirements.

Suture Button Fixation Versus Syndesmotic Screws in Supination-External Rotation Type 4 Injuries: A Cost-Effectiveness Analysis.

PubMed

Neary, Kaitlin C; Mormino, Matthew A; Wang, Hongmei

2017-01-01

In stress-positive, unstable supination-external rotation type 4 (SER IV) ankle fractures, implant selection for syndesmotic fixation is a debated topic. Among the available syndesmotic fixation methods, the metallic screw and the suture button have been routinely compared in the literature. In addition to strength of fixation and ability to anatomically restore the syndesmosis, costs associated with implant use have recently been called into question. This study aimed to examine the cost-effectiveness of the suture button and determine whether suture button fixation is more cost-effective than two 3.5-mm syndesmotic screws not removed on a routine postoperative basis. Economic and decision analysis; Level of evidence, 2. Studies with the highest evidence levels in the available literature were used to estimate the hardware removal and failure rates for syndesmotic screws and suture button fixation. Costs were determined by examining the average costs for patients who underwent surgery for unstable SER IV ankle fractures at a single level-1 trauma institution. A decision analysis model that allowed comparison of the 2 fixation methods was developed. Using a 20% screw hardware removal rate and a 4% suture button hardware removal rate, the total cost for 2 syndesmotic screws was US$20,836 and the total effectiveness was 5.846. This yielded a total cost of $3564 per quality-adjusted life-year (QALY) over an 8-year time period. The total cost for suture button fixation was $19,354 and the total effectiveness was 5.904, resulting in a total cost of $3294 per QALY over the same time period. A sensitivity analysis was then conducted to assess suture button fixation costs as well as screw and suture button hardware removal rates. Other possible treatment scenarios were also examined, including 1 screw and 2 suture buttons for operative fixation of the syndesmosis. To become more cost-effective, the screw hardware removal rate would have to be reduced to less than 10%. Furthermore, fixation with a single suture button continued to be the dominant treatment strategy compared with 2 suture buttons, 1 screw, and 2 screws for syndesmotic fixation. This cost-effectiveness analysis suggests that for unstable SER IV ankle fractures, suture button fixation is more cost-effective than syndesmotic screws not removed on a routine basis. Suture button fixation was a dominant treatment strategy, because patients spent on average $1482 less and had a higher quality of life by 0.058 QALYs compared with patients who received fixation with 2 syndesmotic screws. Assuming that functional outcomes and failure rates were equivalent, screw fixation only became more cost-effective when the screw hardware removal rate was reduced to less than 10% or when the suture button cost exceeded $2000. In addition, fixation with a single suture button device proved more cost-effective than fixation with either 1 or 2 syndesmotic screws.

Syndesmotic fixation in supination-external rotation ankle fractures: a prospective randomized study.

PubMed

Pakarinen, Harri J; Flinkkilä, Tapio E; Ohtonen, Pasi P; Hyvönen, Pekka H; Lakovaara, Martti T; Leppilahti, Juhana I; Ristiniemi, Jukka Y

2011-12-01

This study was designed to assess whether transfixion of an unstable syndesmosis is necessary in supination-external rotation (Lauge-Hansen SE/Weber B)-type ankle fractures. A prospective study of 140 patients with unilateral Lauge-Hansen supination-external rotation type 4 ankle fractures was done. After bony fixation, the 7.5-Nm standardized external rotation (ER) stress test for both ankles was performed under fluoroscopy. A positive stress examination was defined as a difference of more than 2 mm side-to-side in the tibiotalar or tibiofibular clear spaces on mortise radiographs. If the stress test was positive, the patient was randomized to either syndesmotic transfixion with 3.5-mm tricortical screws or no syndesmotic fixation. Clinical outcome was assessed using the Olerud-Molander scoring system, RAND 36-Item Health Survey, and Visual Analogue Scale (VAS) to measure pain and function after a minimum 1-year of followup. Twenty four (17%) of 140 patients had positive standardized 7.5-Nm ER stress tests after malleolar fixation. The stress view was positive three times on tibiotalar clear space, seven on tibiofibular clear space, and 14 times on both tibiotalar and tibiofibular clear spaces. There was no significant difference between the two randomization groups with regards to Olerud-Molander functional score, VAS scale measuring pain and function, or RAND 36-Item Health Survey pain or physical function at 1 year. Relevant syndesmotic injuries are rare in supination-external rotation ankle fractures, and syndesmotic transfixion with a screw did not influence the functional outcome or pain after the 1-year followup compared with no fixation.

Lumbar hemangioma masking a plasma cell tumor--case report and review of the literature.

PubMed

Haque, Maahir U; Wilson, Adam N; Blecher, Haim D; Reich, Steven M

2013-08-01

Vertebral hemangiomata are ubiquitous bone tumors. Often multiple, they are generally benign in nature and slow growing. They typically have a predictable radiographic appearance. Occasionally, hemangiomata may behave in a more aggressive manner, causing pathologic fracture or even symptoms/signs of nerve compression. In such cases, one must be careful not to assume that an atypical hemangioma is responsible. Coexisting, more malignant processes may be present and sometimes may be radiographically undetectable in the setting of acute fracture. This was the case in our patient. Case report/university spine surgery center. The patient underwent a corpectomy of her affected vertebra with conversion to a total spondylectomy when intraoperative frozen section was consistent with plasma cell neoplasm. A reconstruction with vertebral body replacement and fusion through anterior and posterior approaches was completed. Subsequently, the literature was reviewed for other cases of atypical hemangiomata to investigate the incidence of coexistent lesions. This patient presented with pain secondary to an unstable pathologic vertebral body fracture. Surgery to stabilize her spine was elected. Intraoperative recognition of abnormal-appearing tissue led to the diagnosis of a plasma cell neoplasm that was not seen on imaging. Coexistent in the same vertebra was hemangiomatous tissue that was visible on preoperative imaging. There are rare reports of aggressively behaving hemangiomata that mainly have occurred in the thoracic spine. There have been no reports of the coexistence of a hemangioma and a plasma cell tumor in the same vertebral level in the setting of acute compression fracture. Copyright © 2013 Elsevier Inc. All rights reserved.

Increased wound complication with intramedullary screw fixation of clavicle fractures: Is it thermal necrosis?

PubMed

Domos, Peter; Tytherleigh-Strong, Graham; Van Rensburg, Lee

2017-01-01

Adult mid-shaft clavicle fractures are common injuries. For displaced fractures, open reduction with plate or intramedullary (IM) fixation is the widely used techniques. All methods have their own potential drawbacks, especially related to local soft tissue complications. There is little information about outcome and management of local wound complications after clavicle fracture fixations. Ninety-seven patients underwent open reduction and internal fixation, 17 were treated with IM screw fixation and 80 with plate fixation. Wound complication occurred in eight patients (8.2%) and rates differed significantly between IM and plate fixations (29.4% vs. 3.8%). Patients were assessed on average 58.3 months with visual analogue pain scores (VASs), Oxford Shoulder Score (OSS), and QuickDash (QD) score. Five patients had wound breakdown and three patients had wound erythema. In seven patients with stable fixation, it was possible to "dress and suppress" with average 3 weeks of oral antibiotics. One patient had unstable fixation and required longer antibiotic treatment with early screw removal. One patient developed a chronic discharging wound, requiring debridement and later plate removal. At final follow-up, all wounds remained healed, bony union was achieved in all. The average scores were: VAS 1, OSS 46, and QD 4.5. Good function with dry healed wound and united clavicle can be achieved. Further studies are required to investigate the difference in soft tissue complication rates, which may be due to the IM technique of retrograde drilling with a guide wire and due to aseptic thermal bone necrosis, rather than true infection.

An Experimental and Numerical Study on Cracking Behavior of Brittle Sandstone Containing Two Non-coplanar Fissures Under Uniaxial Compression

NASA Astrophysics Data System (ADS)

Yang, Sheng-Qi; Tian, Wen-Ling; Huang, Yan-Hua; Ranjith, P. G.; Ju, Yang

2016-04-01

To understand the fracture mechanism in all kinds of rock engineering, it is important to investigate the fracture evolution behavior of pre-fissured rock. In this research, we conducted uniaxial compression experiments to evaluate the influence of ligament angle on the strength, deformability, and fracture coalescence behavior of rectangular prismatic specimens (80 × 160 × 30 mm) of brittle sandstone containing two non-coplanar fissures. The experimental results show that the peak strength of sandstone containing two non-coplanar fissures depends on the ligament angle, but the elastic modulus is not closely related to the ligament angle. With the increase of ligament angle, the peak strength decreased at a ligament angle of 60°, before increasing up to our maximum ligament angle of 120°. Crack initiation, propagation, and coalescence were all observed and characterized from the inner and outer tips of pre-existing non-coplanar fissures using photographic monitoring. Based on the results, the sequence of crack evolution in sandstone containing two non-coplanar fissures was analyzed in detail. In order to fully understand the crack evolution mechanism of brittle sandstone, numerical simulations using PFC2D were performed for specimens containing two non-coplanar fissures under uniaxial compression. The results are in good agreement with the experimental results. By analyzing the stress field, the crack evolution mechanism in brittle sandstone containing two non-coplanar fissures under uniaxial compression is revealed. These experimental and numerical results are expected to improve the understanding of the unstable fracture mechanism of fissured rock engineering structures.

The effect of laparotomy and external fixator stabilization on pelvic volume in an unstable pelvic injury.

PubMed

Ghanayem, A J; Wilber, J H; Lieberman, J M; Motta, A O

1995-03-01

Determine if laparotomy further destabilizes an unstable pelvic injury and increases pelvic volume, and if reduction and stabilization restores pelvic volume and prevents volume changes secondary to laparotomy. Cadaveric pelvic fracture model. Unilateral open-book pelvic ring injuries were created in five fresh cadaveric specimens by directly disrupting the pubic symphysis, left sacroliac joint, and sacrospinous and sacrotuberous ligaments. Pelvic volume was determined using computerized axial tomography for the intact pelvis, disrupted pelvis with both a laparotomy incision opened and closed, and disrupted pelvis stabilized and reduced using an external fixator with the laparotomy incision opened. The average volume increase in the entire pelvis (from the top of the iliac crests to the bottom of the ischial tuberosities) between a nonstabilized injury with the abdomen closed and then subsequently opened was 15 +/- 5% (423 cc). The average increase in entire pelvic volume between a stabilized and reduced pelvis and nonstabilized pelvis, both with the abdomen open, was 26 +/- 5% (692 cc). The public diastasis increased from 3.9 to 9.3 cm in a nonstabilized pelvis with the abdomen closed and then subsequently opened. Application of a single-pin anterior-frame external fixator reduced the pubic diastasis anatomically and reduced the average entire and true (from the pelvic brim to the ischeal tuberosities) pelvic volumes to within 3 +/- 4 and 8 +/- 6% of the initial volume, respectively. We believe that the abdominal wall provides stability to an unstable pelvic ring injury via a tension band effect on the iliac wings. Our results demonstrate that a laparotomy further destabilized an open-book pelvic injury and subsequently increased pelvic volume and pubic diastasis. This could potentially increase blood loss from the pelvic injury and delay the tamponade effect of reduction and stabilization. A single-pin external fixator prevents the destabilizing effect of the laparotomy and effectively reduces pelvic volume. These data support reduction and temporary stabilization of unstable pelvic injuries before or concomitantly with laparotomy.

Supination external rotation ankle fractures: A simpler pattern with better outcomes

PubMed Central

Tejwani, Nirmal C; Park, Ji Hae; Egol, Kenneth A

2015-01-01

Background: Rotational injuries are the most common and usually classified as per the Lauge Hansen classification; with the most common subgroup being the supination external rotation (SER) mechanism. Isolated fractures of the distal fibula (SE2) without associated ligamentous injury are usually treated with a splint or brace and the patient may be allowed to weight bear as tolerated. This study reports the functional outcomes following a stable, low energy, rotational ankle fracture supination external rotation (SER2) when compared to unstable SER4 fractures treated operatively. Materials and Methods: 64 patients who were diagnosed and treated nonoperatively for a stable SER2 ankle fracture were followed prospectively. In the comparison group, 93 operatively treated fibular fractures were extracted from a prospectively collected database and evaluated comparison. Baseline characteristics obtained by trained interviewers at the time of injury included: Patient demographics, short form-36, short musculoskeletal functional assessment (SMFA) and American Orthopedic Foot and Ankle Society (AOFAS) questionnaires. Patients were followed at 3, 6 and 12 months postsurgery. Additional information obtained at each followup point included any complications or evidence on fracture healing. Data were analyzed by the Student's t-test and theFisher's Exact Test to compare demographic and functional outcomes between the two cohorts. P < 0.05 was considered to be significant. Results: The average of patients’ age in the stable fracture cohort was 43 versus 45 in the SER4 group. Nearly 64% of the patient population was female when compared with 37% in the operative group. In the SER2 by 6 months all patients had returned to baseline functional status. There were 18 delayed unions (all healed by 6 months). Based on the functional outcome scores all patients had returned to preoperative level. In comparison, SE4 patients had less functional recovery at 3 and 6 months (P < 0.05) based on the SMFA scores and at 3, 6 and 12 months based on the AOFAS (P < 0.001) scores. There was no difference in pain levels between the two groups at all time points. There were three nonunions in the SE4 group and six delayed unions. Conclusions: An SER2 ankle fracture is a relatively benign injury with functional limitations resolving by 3 months while the need for surgical fixation in SER ankle fractures appears to affect lower extremity function to a greater degree for a longer time period. Patients should be counseled as to these expected outcomes. PMID:26015612

A Comparison of Sacroiliac and Pubic Rami Fracture Occurrences in Oblique Side Impact Tests on Nine Post Mortem Human Subjects.

PubMed

Petit, Philippe; Trosseille, Xavier; Lebarbé, Mathieu; Baudrit, Pascal; Potier, Pascal; Compigne, Sabine; Masuda, Mitsutoshi; Yamaoka, Akira; Yasuki, Tsuyoshi; Douard, Richard

2015-11-01

The WorldSID dummy can be equipped with both a pubic and a sacroiliac joint (S-I joint) loadcell. Although a pubic force criterion and the associated injury risk curve are currently available and used in regulation (ECE95, FMVSS214), as of today injury mechanisms, injury criteria, and injury assessment reference values are not available for the sacroiliac joint itself. The aim of this study was to investigate the sacroiliac joint injury mechanism. Three configurations were identified from full-scale car crashes conducted with the WorldSID 50th percentile male where the force passing through the pubis in all three tests was approximately 1500 N while the sacroiliac Fy/Mx peak values were 4500 N/50 Nm, 2400 N/130 Nm, and 5300 N/150 Nm, respectively. These tests were reproduced using a 150 kg guided probe impacting Post Mortem Human Subjects (PMHS) at 8 m/s, 5.4 m/s and 7.5 m/s. The shape and the orientation of the impacting face of the probe were selected to match the WorldSID pubic Fy and sacroiliac Fy/Mx loads of the three vehicle test configurations. Three PMHS were tested in each of the three configurations (nine PMHS in total). In the first PMHS configuration, one specimen sustained an AIS 3 injury and one sustained an AIS 4 injury (an unstable pelvis with complete disruption of the posterior arch, a sacroiliac joint disruption associated with an iliac fracture, and a pubic symphysis separation). In the second configuration, all specimens sustained a fracture of the superior lateral iliac wing (AIS 2). In the third configuration, one specimen sustained a partial disruption of the anterior arch (AIS 2). Based on the data from strain gauges located on the pubic rami and near the sacroiliac joint, the pubic rami fractures were identified as occurring prior to the sacroiliac fractures. Out of nine impactor tests performed, the PMHS S-I joint injuries were observed to consistently be associated with pelvic anterior arch fractures. In addition, from the injury sequences derived from strain gauges located on the specimen pelvises and on the injury assessments obtained by necropsy, the S-I joint fractures were observed to occur after the anterior arch fractures.

Surgical Therapy of Cervical Spine Fracture in Patients With Ankylosing Spondylitis

PubMed Central

Ma, Jun; Wang, Ce; Zhou, Xuhui; Zhou, Shengyuan; Jia, Lianshun

2015-01-01

Abstract The present study aimed to explore surgical treatments and assess the effects based on the features of cervical spine fracture in patients with ankylosing spondylitis (AS) and to summarize the experiences in perioperative management. Retrospective analysis was performed in 25 AS patients with cervical spine fracture treated in our hospital from January 2011 to December 2013. The patients were divided according to fracture segments, including 4 cases at C4 to C5, 8 cases at C5 to C6, and 13 cases at C6 to C7. Among them, 12 belonged to I type, 5 to II type, and 8 to III type based on the improved classification method for AS cervical spine fracture. The Subaxial Cervical Spine Injury Classification score for these patients was 7.2 ± 1.3, and the assessment of their neurological function states showed 6 patients (24%) were in American Spinal Injury Association (ASIA) A grade, 1 (4%) in ASIA B grade, 3 (12%) in ASIA C grade, 12 (48%) in ASIA D grade, and 3 (12%) in ASIA E grade. Surgical methods contained simple anterior approach alone, posterior approach alone, and combined posterior–anterior or anterior–posterior approach. The average duration of patients’ hospital stay was 38.6 ± 37.6, and the first surgical methods were as follows: anterior approach alone on 6 cases, posterior surgery alone on 9 cases, and combined posterior–anterior or anterior–posterior approach on 10 patients. The median segments of fixation and fusion were 4.1 ± 1.4 sections. Thirteen patients developed complications. During 2 to 36 months of postoperative follow-up, 1 patient died of respiratory failure caused by pulmonary infections 2 months after leaving hospital. At the end of the follow-up, bone graft fusion was achieved in the rest of patients, and obvious looseness or migration of internal fixation was not observed. In addition, the preoperative neurological injury in 12 patients (54.5%) was also alleviated in different levels. AS cervical spine fracture, an unstable fracture, should be treated with operation, and satisfactory effects will be achieved after the individualized surgical treatment according to the improved classification method for AS cervical spine fracture. PMID:26554765

Paediatric injury from indoor trampoline centres.

PubMed

Mulligan, Christopher S; Adams, Susan; Brown, Julie

2017-10-01

Indoor trampoline parks are increasing as a source of injuries among children. We conducted a prospective cohort study, with semi-structured interview and medical record review, of children aged <17 years presenting to a paediatric emergency department following an injury at an indoor trampoline park. In a 6-month period in 2014, 40 such children (55% female) presented to the department. Common mechanisms were individual jumpers falling while attempting a somersault or trick, landing awkwardly on an obstacle such as a ball or protective padding, and multiple users on a single trampoline. Most sustained soft tissue injuries (n=22, 55%) and fractured bones (n=15, 37.5%). One child sustained an unstable cervical fracture/dislocation. Unlike domestic trampolines, where the majority of injuries occur from falling off, most trampoline-park injuries occur on the trampoline surface. These differences require injury prevention strategies that engage children, carers and businesses to meet best practice design and management standards. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

[Biomechanical performance of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability].

PubMed

Liu, Tie-long; Yan, Wang-jun; Han, Yu; Ye, Xiao-jian; Jia, Lian-shun; Li, Jia-shun; Yuan, Wen

2010-05-01

To compare the biomechanical performances of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability, and test the effect of different fixation strengths and fixation approaches on the surgical outcomes. Six specimens of the atlantoaxial complex (C0-C3) were used to establish models of the normal complex, unstable complex (type II odontoid fracture) and fixed complex. On the wd-5 mechanical testing machine, the parameters including the strength and rigidity of anti-rotation, change and strength of stress, and stability were measured for the normal complex, atlantoaxial instability complex, the new type titanium cable fixation system, Atlas titanium cable, Songer titanium cable, and stainless wire. The strength and rigidity of anti-rotation, change and strength of stress, stability of flexion, extension and lateral bending of the unstable atlantoaxial complex fixed by the new double locking titanium cable fixation system were superior to those of the Songer or Atlas titanium cable (P<0.05) and medical stainless wire (P<0.05). Simultaneous cable fastening on both sides resulted in better fixation effect than successive cable fastening (P<0.05). Better fixation effect was achieved by fastening the specimen following a rest (P<0.05). The fixation effects can be enhanced by increased fastening strengths. The new type double locking titanium cable fixation system has better biomechanical performance than the conventional Songer and Atlas titanium cables. Fastening the unstable specimens after a rest following simultaneous fastening of the specimen on both sides produces better fixation effect.

Sticking our neck out: is magnetic resonance imaging needed to clear an obtunded patient's cervical spine?

PubMed

Satahoo, Shevonne S; Davis, James S; Garcia, George D; Alsafran, Salman; Pandya, Reeni K; Richie, Cheryl D; Habib, Fahim; Rivas, Luis; Namias, Nicholas; Schulman, Carl I

2014-03-01

Evaluating the cervical spine in the obtunded trauma patient is a subject fraught with controversy. Some authors assert that a negative computed tomography (CT) scan is sufficient. Others argue that CT alone misses occult unstable injuries, and magnetic resonance imaging (MRI) will alter treatment. This study examines the data in an urban, county trauma center to determine if a negative cervical spine CT scan is sufficient to clear the obtunded trauma patient. Records of all consecutive patients admitted to a level 1 trauma center from January 2000 to December 2011 were retrospectively analyzed. Patients directly admitted to the intensive care unit with a Glasgow Coma Scale score ≤13, contemporaneous CT and MRI, and a negative CT reading were included. The results of the cervical spine MRI were analyzed. A total of 309 patients had both CT and MRI, 107 (35%) of whom had negative CTs. Mean time between CT and MRI was 16 d. Of those patients, seven (7%) had positive acute traumatic findings on MRI. Findings included ligamentous injury, subluxation, and fracture. However, only two of these patients required surgical intervention. None had unstable injuries. In the obtunded trauma patient with a negative cervical spine CT, obtaining an MRI does not appear to significantly alter management, and no unstable injuries were missed on CT scan. This should be taken into consideration given the current efforts at cost-containment in the health care system. It is one of the larger studies published to date. Copyright © 2014 Elsevier Inc. All rights reserved.

Controversies in Treatment of Acetabular Fracture

PubMed Central

Grubor, Predrag; Krupic, Ferid; Biscevic, Mirza; Grubor, Milan

2015-01-01

Introduction: Acetabular fractures treatment represents a great controversy, challenge and dilemma for an orthopedic surgeon. Aim: The aim of the paper was to present the results of treatment of 96 acetabular fractures in the Clinic of Traumatology Banja Luka, in the period from 2003 to 2013, as well as to raise awareness regarding the controversy in the methods of choice in treating acetabulum fractures. Material and methods: The series consists of 96 patients, 82 males and 14 females, average age 40.5 years. Traffic trauma was the cause of fractures in 79 patients (85%), and in 17 patients (15%) fractures occurred due to falls from height. Polytrauma was present in 31 patients (32%). According to the classification of Judet and Letournel, representation of acetabular fractures was as follows: posterior wall in 32 patients, posterior column in 28, anterior wall in 4, anterior column in 2, transverse fractures in 8, posterior wall and posterior column in 10, anterior and posterior wall in 6, both- column in 4 and transversal fracture and posterior wall in 2 patients. 14 patients were treated with traction, that is, 6 patients with femoral traction and 8 patients with both lateral and femoral traction. 82 patients (86.4%) were surgically treated. Kocher-Langenbeck approach was applied in the treatment of 78 patients. In two patients from the Kocher-Langenbeck’s approach, the Ollier’s approach had to be applied as well. Two acetabular were primarily treated with Ollier’s approach. Extended Smith- Peterson’s approach was applied 4 times, and Emile Letournel’s (ilioinguinal) approach 14 times. Results: Functional outcome (after follow-up of 18 months), according to the Harris hip score of surgical treatment in 82 patients, was as follows: good 46 (56%), satisfactory 32 (39%) and poor 4 (5%). Results of acetabulum fractures treated with traction were: good 8 (57%), satisfactory 4 (28%) and poor 2 (15%). According to the Brook’s classification of heterotopic ossification, periarticular hetero-tropic calcifications after surgical treatment were: 0° in 65 patients (79%), I-II° in 9 patients (11%) and III-IV ° in 8 patients (10%). Calcifications in 14 patients treated with traction of heterotopic ossification by Brook-s classification were as follows: 0° in 10 patients (72%), I-II ° in 3 patients (22%) and III-IV° in 1 patient (6%). Conclusion: At the occurrence of acetabular fracture, it is necessary to start the treatment immediately, with an obligatory application of thromboembolic and antibiotic prophylaxis. Conservative treatment is acceptable if the dislocation of fracture is less than 5 mm. Indications for surgical treatment are incongruent or unstable fractures with verified dislocation greater than 5 mm, as well as when the radiography measured by JM Matta shows incongruence of acetabular roof less than 40° in all planes. Kocher-Langenbeck approach is the choice of surgical approach for the management of posterior column / wall, and Letournel’s (ilioinguinal) approach is the choice for the management of anterior wall/column. PMID:25870470

Physically Based Failure Criteria for Transverse Matrix Cracking

NASA Technical Reports Server (NTRS)

Davila, Carlos G.; Camanho, Pedro P.

2003-01-01

A criterion for matrix failure of laminated composite plies in transverse tension and in-plane shear is developed by examining the mechanics of transverse matrix crack growth. Matrix cracks are assumed to initiate from manufacturing defects and can propagate within planes parallel to the fiber direction and normal to the ply mid-plane. Fracture mechanics models of cracks in unidirectional laminates, embedded plies and outer plies are developed to determine the onset and direction of propagation for unstable crack growth. The models for each ply configuration relate ply thickness and ply toughness to the corresponding in-situ ply strength. Calculated results for several materials are shown to correlate well with experimental results.

Rockfall risk assessment for a road along the coastal rocky slope of Maratea (Basilicata Region, Italy)

NASA Astrophysics Data System (ADS)

Pellicani, R.; Spilotro, G.; Colangelo, G.; Petraglia, A.; Pizzo, V.

2012-04-01

The rockfall risk has been evaluated for the Tirrena Inferiore State Road SS18 between 220+600 and 243+670 Kilometers in the coastal area of Maratea (Basilicata, Italy) through a specific multilayer technique. These results are particularly significant as validated in field through the occurrence of rockfall events after the study. The study part of "Tirrena Inferiore" SS18 road is often affected by rockfalls, which periodically (coinciding with abundant rainfalls, earthquakes and temperature lowering) cause large amount of damage and traffic interruptions. In order to assess the rockfall risk and define the countermeasure needed to mitigate the risk, an integrated index-based and physically-based approach was implemented. The roadway is subject to slopes with steep rocky vertical or sub-vertical faces affected by different systems of discontinuities, that show a widespread fracturing. The superficial parts of slopes are characterized by gaping fracturing, often karstified. Several historical rockfall events were recognized in the area and numerous geomechanical analyses, finalized to the stability analysis of rock walls, were carried out. The localization of the potentially unstable areas and the quantification of relative rockfall risk were evaluated through three successive phases of analysis. First, a map based on SMR (Slope Mass Rating) Index of Romana (1985) was produced, through a spatial analysis of both geomechanical parameters, such as the RMR Index of Bieniawski, and the distribution of the discontinuities. This approach therefore allowed the estimation of the potentially unstable zones and their classification on the basis of the resulting stability degree. Subsequently, an analysis of the rockfall trajectories in correspondence to the most unstable zones of slope was carried out by using ROTOMAP, a 3-dimensional rock-fall simulation software. The input data for computing the rockfall trajectories are the following: (1) digital terrain model (DTM), (2) location of rock-fall release points (source areas), (3) geometrical parameters of block rolling, such as limit angle of flight, impact and rebound, and (4) geomechanical parameters of block rolling, such as the coefficients of normal and tangential energy restitution. For each DTM cell the software calculates the number of blocks passing through, the maximum rock-fall velocity and the maximum flying height. These information were used in order to verify the efficiency of the existing rockfall protection systems. Finally, the rockfall risk map was realized through the evaluation of the spatial distribution of the following three parameters: (i) lithology, (ii) kinematic compatibility, and (iii) historical rockfall events. After quantifying the risk, the most suitable typologies of rockfall protection systems were identified for the most unstable sections of slopes. The importance and usefulness of this study derives from the validation of the obtained results, in terms of risk, through the occurrence of new rockfall events in those areas for which the highest level of rockfall risk was defined in previous study.

Stable Versus Unstable Grade II High Ankle Sprains: A Prospective Study Predicting the Need for Surgical Stabilization and Time to Return to Sports.

PubMed

Calder, James D; Bamford, Richard; Petrie, Aviva; McCollum, Graham A

2016-04-01

To investigate grade II syndesmosis injuries in athletes and identify factors important in differentiating stable from dynamically unstable ankle sprains and those associated with a longer time to return to sports. Sixty-four athletes with an isolated syndesmosis injury (without fracture) were prospectively assessed, with a mean follow-up period of 37 months (range, 24 to 66 months). Those with an associated deltoid ligament injury or osteochondral lesion were included. Those whose injuries were considered stable (grade IIa) were treated conservatively with a boot and rehabilitation. Those whose injuries were clinically unstable underwent arthroscopy, and if instability was confirmed (grade IIb), the syndesmosis was stabilized. Clinical and magnetic resonance imaging assessments of injury to individual ligaments were recorded, along with time to return to play. A power analysis estimated that each group would need 28 patients. All athletes returned to the same level of professional sport. The 28 patients with grade IIa injuries returned at a mean of 45 days (range, 23 to 63 days) compared with 64 days (range, 27 to 104 days) for those with grade IIb injuries (P < .0001). There was a highly significant relationship between clinical and magnetic resonance imaging assessments of ligament injury (anterior tibiofibular ligament [ATFL], anterior-inferior tibiofibular ligament [AITFL], and deltoid ligament, P < .0001). Instability was 9.5 times as likely with a positive squeeze test and 11 times as likely with a deltoid injury. Combined injury to the anterior-inferior tibiofibular ligament and deltoid ligament was associated with a delay in return to sports. Concomitant injury to the ATFL indicated a different mechanism of injury-the syndesmosis is less likely to be unstable and is associated with an earlier return to sports. A positive squeeze test and injury to the ATFL and deltoid ligament are important factors in differentiating stable from dynamically unstable grade II injuries and may be used to identify which athletes may benefit from early arthroscopic assessment and stabilization. They may also be important in predicting the time frame for athletes' expected return to play. Level II, prospective comparative study. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Ancient microbial activity recorded in fracture fillings from granitic rocks (Äspö Hard Rock Laboratory, Sweden).

PubMed

Heim, C; Lausmaa, J; Sjövall, P; Toporski, J; Dieing, T; Simon, K; Hansen, B T; Kronz, A; Arp, G; Reitner, J; Thiel, V

2012-07-01

Fracture minerals within the 1.8-Ga-old Äspö Diorite (Sweden) were investigated for fossil traces of subterranean microbial activity. To track the potential organic and inorganic biosignatures, an approach combining complementary analytical techniques of high lateral resolution was applied to drill core material obtained at -450 m depth in the Äspö Hard Rock Laboratory. This approach included polarization microscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS), confocal Raman microscopy, electron microprobe (EMP) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The fracture mineral succession, consisting of fluorite and low-temperature calcite, showed a thin (20-100 μm), dark amorphous layer lining the boundary between the two phases. Microscopic investigations of the amorphous layer revealed corrosion marks and, in places, branched tubular structures within the fluorite. Geochemical analysis showed significant accumulations of Si, Al, Mg, Fe and the light rare earth elements (REE) in the amorphous layer. In the same area, ToF-SIMS imaging revealed abundant, partly functionalized organic moieties, for example, C(x)H(y)⁺, C(x)H(y)N⁺, C(x)H(y)O⁺. The presence of such functionalized organic compounds was corroborated by Raman imaging showing bands characteristic of C-C, C-N and C-O bonds. According to its organic nature and the abundance of relatively unstable N- and O- heterocompounds, the organic-rich amorphous layer is interpreted to represent the remains of a microbial biofilm that established much later than the initial cooling of the Precambrian host rock. Indeed, δ¹³C, δ¹⁸O and ⁸⁷Sr/⁸⁶Sr isotope data of the fracture minerals and the host rock point to an association with a fracture reactivation event in the most recent geological past. © 2012 Blackwell Publishing Ltd.

Strong synergistic effects in PLA/PCL blends: Impact of PLA matrix viscosity.

PubMed

Ostafinska, Aleksandra; Fortelný, Ivan; Hodan, Jiří; Krejčíková, Sabina; Nevoralová, Martina; Kredatusová, Jana; Kruliš, Zdeněk; Kotek, Jiří; Šlouf, Miroslav

2017-05-01

Blends of two biodegradable polymers, poly(lactic acid) (PLA) and poly(ϵ-caprolactone) (PCL), with strong synergistic improvement in mechanical performance were prepared by melt-mixing using the optimized composition (80/20) and the optimized preparation procedure (a melt-mixing followed by a compression molding) according to our previous study. Three different PLA polymers were employed, whose viscosity decreased in the following order: PLC ≈ PLA1 > PLA2 > PLA3. The blends with the highest viscosity matrix (PLA1/PCL) exhibited the smallest PCL particles (d∼0.6μm), an elastic-plastic stable fracture (as determined from instrumented impact testing) and the strongest synergistic improvement in toughness (>16× with respect to pure PLA, exceeding even the toughness of pure PCL). According to the available literature, this was the highest toughness improvement in non-compatiblized PLA/PCL blends ever achieved. The decrease in the matrix viscosity resulted in an increase in the average PCL particle size and a dramatic decrease in the overall toughness: the completely stable fracture (for PLA1/PCL) changed to the stable fracture followed by unstable crack propagation (for PLA2/PCL) and finally to the completely brittle fracture (for PLA3/PCL). The stiffness of all blends remained at well acceptable level, slightly above the theoretical predictions based on the equivalent box model. Despite several previous studies, the results confirmed that PLA and PCL could behave as compatible polymers, but the final PLA/PCL toughness is extremely sensitive to the PCL particle size distribution, which is influenced by both processing conditions and PLA viscosity. PLA/PCL blends with high stiffness (due to PLA) and toughness (due to PCL) are very promising materials for medical applications, namely for the bone tissue engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

The prediction of cyclic proximal humerus fracture fixation failure by various bone density measures.

PubMed

Varga, Peter; Grünwald, Leonard; Windolf, Markus

2018-02-22

Fixation of osteoporotic proximal humerus fractures has remained challenging, but may be improved by careful pre-operative planning. The aim of this study was to investigate how well the failure of locking plate fixation of osteoporotic proximal humerus fractures can be predicted by bone density measures assessed with currently available clinical imaging (realistic case) and a higher resolution and quality modality (theoretical best-case). Various density measures were correlated to experimentally assessed number of cycles to construct failure of plated unstable low-density proximal humerus fractures (N = 18). The influence of density evaluation technique was investigated by comparing local (peri-implant) versus global evaluation regions; HR-pQCT-based versus clinical QCT-based image data; ipsilateral versus contralateral side; and bone mineral content (BMC) versus bone mineral density (BMD). All investigated density measures were significantly correlated with the experimental cycles to failure. The best performing clinically feasible parameter was the QCT-based BMC of the contralateral articular cap region, providing significantly better correlation (R 2  = 0.53) compared to a previously proposed clinical density measure (R 2  = 0.30). BMC had consistently, but not significantly stronger correlations with failure than BMD. The overall best results were obtained with the ipsilateral HR-pQCT-based local BMC (R 2  = 0.74) that may be used for implant optimization. Strong correlations were found between the corresponding density measures of the two CT image sources, as well as between the two sides. Future studies should investigate if BMC of the contralateral articular cap region could provide improved prediction of clinical fixation failure compared to previously proposed measures. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

GENOA-PFA: Progressive Fracture in Composites Simulated Computationally

NASA Technical Reports Server (NTRS)

Murthy, Pappu L. N.

2000-01-01

GENOA-PFA is a commercial version of the Composite Durability Structural Analysis (CODSTRAN) computer program that simulates the progression of damage ultimately leading to fracture in polymer-matrix-composite (PMC) material structures under various loading and environmental conditions. GENOA-PFA offers several capabilities not available in other programs developed for this purpose, making it preferable for use in analyzing the durability and damage tolerance of complex PMC structures in which the fiber reinforcements occur in two- and three-dimensional weaves and braids. GENOA-PFA implements a progressive-fracture methodology based on the idea that a structure fails when flaws that may initially be small (even microscopic) grow and/or coalesce to a critical dimension where the structure no longer has an adequate safety margin to avoid catastrophic global fracture. Damage is considered to progress through five stages: (1) initiation, (2) growth, (3) accumulation (coalescence of propagating flaws), (4) stable propagation (up to the critical dimension), and (5) unstable or very rapid propagation (beyond the critical dimension) to catastrophic failure. The computational simulation of progressive failure involves formal procedures for identifying the five different stages of damage and for relating the amount of damage at each stage to the overall behavior of the deteriorating structure. In GENOA-PFA, mathematical modeling of the composite physical behavior involves an integration of simulations at multiple, hierarchical scales ranging from the macroscopic (lamina, laminate, and structure) to the microscopic (fiber, matrix, and fiber/matrix interface), as shown in the figure. The code includes algorithms to simulate the progression of damage from various source defects, including (1) through-the-thickness cracks and (2) voids with edge, pocket, internal, or mixed-mode delaminations.

Instability in dynamic fracture

NASA Astrophysics Data System (ADS)

Fineberg, J.; Marder, M.

1999-05-01

The fracture of brittle amorphous materials is an especially challenging problem, because the way a large object shatters is intimately tied to details of cohesion at microscopic scales. This subject has been plagued by conceptual puzzles, and to make matters worse, experiments seemed to contradict the most firmly established theories. In this review, we will show that the theory and experiments fit within a coherent picture where dynamic instabilities of a crack tip play a crucial role. To accomplish this task, we first summarize the central results of linear elastic dynamic fracture mechanics, an elegant and powerful description of crack motion from the continuum perspective. We point out that this theory is unable to make predictions without additional input, information that must come either from experiment, or from other types of theories. We then proceed to discuss some of the most important experimental observations, and the methods that were used to obtain the them. Once the flux of energy to a crack tip passes a critical value, the crack becomes unstable, and it propagates in increasingly complicated ways. As a result, the crack cannot travel as quickly as theory had supposed, fracture surfaces become rough, it begins to branch and radiate sound, and the energy cost for crack motion increases considerably. All these phenomena are perfectly consistent with the continuum theory, but are not described by it. Therefore, we close the review with an account of theoretical and numerical work that attempts to explain the instabilities. Currently, the experimental understanding of crack tip instabilities in brittle amorphous materials is fairly detailed. We also have a detailed theoretical understanding of crack tip instabilities in crystals, reproducing qualitatively many features of the experiments, while numerical work is beginning to make the missing connections between experiment and theory.

Complications of volar locking plating of distal radius fractures in 576 patients with 3.2 years follow-up.

PubMed

Thorninger, Rikke; Madsen, Mette Lund; Wæver, Daniel; Borris, Lars Carl; Rölfing, Jan Hendrik Duedal

2017-06-01

Volar plating of unstable distal radius fractures (DRF) has become the favoured treatment. The complication rates vary from 3 to 36%. The purpose of the study was to estimate the complication rate of volar plating of DRF and its association with AO/OTA fracture type, surgeon experience and type of volar plate. Retrospectively, all patients treated with volar plating of a DRF between February 2009 and June 2013 at Aarhus University Hospital, Denmark were included. AO/OTA fracture type, surgeon experience (1st year, 2nd-5th year resident or consultant), type of plate (VariAx ® , Acu-Loc ® ) and complications were extracted from the electronic medical records. Complications were categorized as carpal tunnel syndrome, other sensibility issues, tendon complications including irritation and rupture, deep infections, complex regional pain syndrome and unidentified DRUJ or scapholunar problems. Reoperations including hardware removal were also charted. 576 patients with a median age of 63 years (min: 15; max: 87) were included. 78% were female and the mean observation time was 3.2 years (min: 2.0; max: 5.4). 78% (n=451) of the patients were treated with VariAx ® and 22% (n=125) with Acu-Loc ® . The overall complication rate was 14.6% (95% CI 11.8-17.7) including carpal tunnel syndrome or change in sensibility in 5.2% and tendon complications in 4.7%. Five flexor tendon ruptures and 12 extensor tendon ruptures were observed. The reoperation rate was 10.4% including 41 cases of hardware removal. A statistically significant association between AO/OTA fracture type C and complications was found. No statistically significant association between complication rate and surgeon experience and type of plate was observed. The majority of DRF patients treated with a volar plate suffer no complications. However, the overall complication rate of 14.6% is substantial. Intra-articular fractures, e.g. AO/OTA-type 23C1-3, had significantly higher complication rates. Neither surgeon experience, nor type of volar plate was able to predict complications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stainless steel versus titanium volar multi-axial locking plates for fixation of distal radius fractures: a randomised clinical trial

PubMed Central

2014-01-01

Background Distal radius fractures are among the most common fractures seen in the hospital emergency department. Of these, over 40% are considered unstable and require some form of fixation. In recent years with the advent of low profile plating, open reduction and internal fixation (ORIF) using volar plates has become the surgical treatment of choice in many hospitals. However, it is currently unknown which plating system has the lowest complication rate and/or superior clinical and radiological outcomes following surgery. Few studies have compared different types of plates, which may have various features, different plate and screw designs or may be manufactured from different materials (for example, stainless steel or titanium). This study will specifically investigate and compare the clinical and radiological outcomes and complication rates of two commonly used volar plating systems for fixation of distal radius fractures: one made from stainless steel (Trimed™ Volar Plate, Trimed™, California, USA) and the other made from titanium (Medartis® Aptus Volar Plate, Medartis®, Basel, Switzerland). The primary aim of this study is to determine if there is a difference on the Patient Reported Wrist Evaluation six months following ORIF using a volar plate for adult patients with a distal radius fracture. Methods/Design This study will implement a randomized prospective clinical trial study design evaluating the outcomes of two different types of volar plates: one plate manufactured from stainless steel (Trimed™ Volar Plate) and one plate manufactured from titanium (Medartis® Aptus Volar Plate). The surgery will be performed at a major trauma hospital in Brisbane, Australia. Outcome measures including function, adverse events, range of movement, strength, disability, radiological findings and health-related quality of life will be collected at 6 weeks, 3, 6, 12 and 24 months following surgery. A parallel economic analysis will also be performed. This randomized clinical trial is due to deliver results in December 2016. Discussion Results from this trial will contribute to the evidence on operative management of distal radius fractures and plate material type. Trial registration ACTRN12612000969864 PMID:24612524

Fracture of the First Cervical Vertebra in a High School Football Player: A Case Report

PubMed Central

Trupiano, Tim P.; Sampson, Michelle L.; Weise, Marc W.

1997-01-01

Objective: To present the case of a high school football player with a burst fracture of the ring of C1 resulting from a “spearing” tackle. Background: Cervical spine fractures are rare in collision sports, but their potentially grave consequences mean that they must be given special attention. Spearing was banned by the National Collegiate Athletic Association and the National Federation of High School Athletic Associations in 1976, and the number of cervical spine fractures in high school and college football players has fallen dramatically. However, cervical spine fractures do still occur, and they present a diagnostic challenge to sports medicine professionals. Differential Diagnosis: Cervical sprain. Treatment: Treatment consists of halo-vest immobilization. Surgical fusion may be necessary for unstable C1-C2 fractures, although initial halo-vest treatment is usually attempted. Uniqueness: A 17-year-old defensive back attempted to make a tackle with his head lowered. He was struck on the superolateral aspect of the helmet by the opposing running back. He remained in the game for another play, but then left the field under his own power, complaining of neck stiffness and headache. Physical examination revealed upper trapezius and occiput tenderness, bilateral cervical muscle spasm, and pain at all extremes of voluntary cervical movement. He was alert and oriented, with a normal neurologic examination. Treatment with ice was attempted but was discontinued due to increased pain and stiffness. Heat resulted in decreased pain and stiffness, but his symptoms persisted, and he was trans- ported to the emergency room. Plain radiographs were read as negative, but a CT scan demonstrated a burst fracture of Cl. He was treated with halo-vest immobilization for 8 weeks and a rigid cervical collar for 8 additional weeks. Physical therapy was then initiated, and normal cervical range of motion and strength were restored within 6 weeks. The athlete competed in track 6 months after the injury and continues to play recreational sports without difficulty. At clinical follow-up 8 months after injury, he had full, painless cervical range of motion and a normal neurologic examination. Conclusions: A potentially devastating cervical spine injury can present insidiously, without dramatic signs or symptoms. Therefore, sports medicine professionals must retain a high index of suspicion when evaluating athletes with cervical spine complaints. ImagesFig 1.Fig 2. PMID:16558448

Outcomes of operative treatment of unstable ankle fractures: a comparison of metallic and biodegradable implants.

PubMed

Noh, Jung Ho; Roh, Young Hak; Yang, Bo Gyu; Kim, Seong Wan; Lee, Jun Suk; Oh, Moo Kyung

2012-11-21

Biodegradable implants for internal fixation of ankle fractures may overcome some disadvantages of metallic implants, such as imaging interference and the potential need for additional surgery to remove the implants. The purpose of this study was to evaluate the outcomes after fixation of ankle fractures with biodegradable implants compared with metallic implants. In this prospectively randomized study, 109 subjects with an ankle fracture underwent surgery with metallic (Group I) or biodegradable implants (Group II). Radiographic results were assessed by the criteria of the Klossner classification system and time to bone union. Clinical results were assessed with use of the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale, Short Musculoskeletal Function Assessment (SMFA) dysfunction index, and the SMFA bother index at three, six, and twelve months after surgery. One hundred and two subjects completed the study. At a mean of 19.7 months, there were no differences in reduction quality between the groups. The mean operative time was 30.2 minutes in Group I and 56.4 minutes in Group II (p < 0.001). The mean time to bone union was 15.8 weeks in Group I and 17.6 weeks in Group II (p = 0.002). The mean AOFAS score was 87.5 points in Group I and 84.3 points in Group II at twelve months after surgery (p = 0.004). The mean SMFA dysfunction index was 8.7 points in Group I and 10.5 points in Group II at twelve months after surgery (p = 0.060). The mean SMFA bother index averaged 3.3 points in Group I and 4.6 points in Group II at twelve months after surgery (p = 0.052). No difference existed between the groups with regard to clinical outcomes for the subjects with an isolated lateral malleolar fracture. The outcomes after fixation of bimalleolar ankle fractures with biodegradable implants were inferior to those after fixation with metallic implants in terms of the score on the AOFAS scale and time to bone union. However, the difference in the final AOFAS score between the groups may not be clinically important. The outcomes associated with the use of biodegradable implants for the fixation of isolated lateral malleolar fractures were comparable with those for metallic implants.

Anterior subcutaneous internal fixation for treatment of unstable pelvic fractures

PubMed Central

2014-01-01

Background Fractures of the pelvic ring including disruption of the posterior elements in high-energy trauma have both high morbidity and mortality rates. For some injury pattern part of the initial resuscitation includes either external fixation or plate fixation to close the pelvic ring and decrease blood loss. In certain situations – especially when associated with abdominal trauma and the need to perform laparotomies – both techniques may put the patient at risk of either pintract or deep plate infections. We describe an operative approach to percutaneously close and stabilize the pelvic ring using spinal implants as an internal fixator and report the results in a small series of patients treated with this technique during the resuscitation phase. Findings Four patients were treated by subcutaneous placement of an internal fixator. Screw fixation was carried out by minimally invasive placement of two supra-acetabular iliac screws. Afterwards, a subcutaneous transfixation rod was inserted and attached to the screws after reduction of the pelvic ring. All patients were allowed to fully weight-bear. No losses of reduction or deep infections occurred. Fracture healing was uneventful in all cases. Conclusion Minimally invasive fixation is an alternative technique to stabilize the pelvic ring. The clinical results illustrate that this technique is able to achieve good results in terms of maintenance of reduction the pelvic ring. Also, abdominal surgeries no longer put the patient at risk of infected pins or plates. PMID:24606833

Stability-based classification for ankle fracture management and the syndesmosis injury in ankle fractures due to a supination external rotation mechanism of injury.

PubMed

Pakarinen, Harri

2012-12-01

The aim of this thesis was to confirm the utility of stability-based ankle fracture classification in choosing between non-operative and operative treatment of ankle fractures, to determine how many ankle fractures are amenable to non-operative treatment, to assess the roles of the exploration and anatomical repair of the AITFL in the outcome of patients with SER ankle fractures, to establish the sensitivities, specificities and interobserver reliabilities of the hook and intraoperative stress tests for diagnosing syndesmosis instability in SER ankle fractures, and to determine whether transfixation of unstable syndesmosis is necessary in SER ankle fractures. The utility of stability based fracture classification to choose between non-operative and operative treatment was assessed in a retrospective study (1) of 253 ankle fractures in skeletally mature patients, 160 of whom were included in the study to obtain an epidemiological profile in a population of 130,000. Outcome was assessed after a minimum follow-up of two years. The role of AITFL repairs was assessed in a retrospective study (2) of 288 patients with Lauge-Hansen SE4 ankle fractures; the AITFL was explored and repaired in one group (n=165), and a similar operative method was used but the AITFL was not explored in another group (n=123). Outcome was measured with a minimum follow-up of two years. Interobserver reliability of clinical syndesomosis tests (study 3) and the role of syndesmosis transfixation (study 4) were assessed in a prospective study of 140 patients with Lauge-Hansen SE4 ankle fractures. The stability of the distal tibiofibular joint was evaluated by the hook and ER stress tests. Clinical tests were carried out by the main surgeon and assistant, separately, after which a 7.5-Nm standardized ER stress test for both ankles was performed; if it was positive, the patient was randomized to either syndesmosis transfixation (13 patients) or no fixation (11 patients) treatment groups. The sensitivity and specificity of both clinical tests were calculated using the standard 7.5-Nm external rotation stress test as reference. Outcome was assessed after a minimum of one year of follow-up. Olerud-Molander (OM) scoring system, RAND 36-Item Health Survey, and VAS to measure pain and function were used as outcome measures in all studies. In study 1, 85 (53%) fractures were treated operatively using the stability based fracture classification. Non-operatively treated patients reported less pain and better OM (good or excellent 89% vs. 71%) and VAS functional scores compared to operatively treated patients although they experienced more displacement of the distal fibula (0 mm 30% vs. 69%; 0-2 mm 65% vs. 25%) after treatment. No non-operatively treated patients required operative fracture fixation during follow-up. In study 2, AITFL exploration and suture lead to equal functional outcome (OM mean, 77 vs. 73) to no exploration or fixation. In study 3, the hook test had a sensitivity of 0.25 and a specificity of 0.98. The external rotation stress test had a sensitivity of 0.58 and a specificity of 0.9. Both tests had excellent interobserver reliability; the agreement was 99% for the hook test and 98% for the stress test. There was no statistically significant difference in functional scores (OM mean, 79.6 vs. 83.6) or pain between syndesmosis transfixation and no fixation groups (Study 4). Our results suggest that a simple stability-based fracture classification is useful in choosing between non-operative and operative treatment of ankle fractures; approximately half of the ankle fractures can be treated non-operatively with success. Our observations also suggest that relevant syndesmosis injuries are rare in ankle fractures due to an SER mechanism of injury. According to our research, syndesmotic repair or fixation in SER ankle fracture has no influence on functional outcome or pain after minimum one year compared with no fixation.

Outcome of distal end clavicle fractures treated with locking plates.

PubMed

Vaishya, Raju; Vijay, Vipul; Khanna, Vikram

2017-02-01

Fractures of the lateral end of the clavicle are relatively uncommon. These fractures are unstable due to the various deforming forces which act on the fragments as well as the small distal fracture fragment. At most times the deforming forces are not taken into consideration, and the fracture is not fixed securely. In this study, we assessed a fixation technique using the precontoured locking plates to find out whether it provided a stable fixation with good functional outcome. Totally, 32 patients with lateral end clavicle fracture (Neer's Type II) were included in the study. After the informed consent and preoperative investigations were obtained, open reduction and internal fixation was done using a 3.5 mm precontoured superior locking plate with lateral extension under general anesthesia. Postoperative X-rays were done on day 1 and every 6 weeks after operation, until radiological union was achieved. The postoperative pain was assessed using Visual Analogue Scale (VAS) on postoperative days 1, 2 and 10. Postoperatively arm pouch sling was given for 2 weeks followed by active mobilization. Patients were asked to do their daily routine work and avoid lifting heavy weights. The functional outcome was assessed at the end of 2nd and 6th months with the help of Disabilities of the Arm, Shoulder and Hand (DASH) scoring. There were no intraoperative complications in the procedure. The mean VAS score on postoperative day 1 was found to be 5 which decreased to 3 on day 2 and 0 on day 10. The mean DASH score was calculated as 11.63 at the end of postoperative month 2 and then 4.6 at the end of month 6. There was one case of malunion in whom the overhead abduction was restricted but was not painful and was managed conservatively. The precontoured locking plates with lateral extension may be a good method to fix the fractures of the lateral end clavicle, which provide a stable fixation with good functional outcome with very few instances of stiffness and decreased range of motion of the shoulder with the hook plates and failure of fixation in screw and K-wire fixations. It may well be the answer to the fixation questions of the lateral clavicle fractures, although larger comparative studies between the surgical treatment methods are required to confirm the same. Copyright © 2017 Daping Hospital and the Research Institute of Surgery of the Third Military Medical University. Production and hosting by Elsevier B.V. All rights reserved.

Screw-blade fixation systems in Pauwels three femoral neck fractures: a biomechanical evaluation.

PubMed

Knobe, Matthias; Altgassen, Simon; Maier, Klaus-Jürgen; Gradl-Dietsch, Gertraud; Kaczmarek, Chris; Nebelung, Sven; Klos, Kajetan; Kim, Bong-Sung; Gueorguiev, Boyko; Horst, Klemens; Buecking, Benjamin

2018-02-01

To reduce mechanical complications after osteosynthesis of femoral neck fractures, improved fixation techniques have been developed including blade or screw-anchor devices. This biomechanical study compares different fixation systems used for treatment of unstable femoral neck fractures with evaluation of failure mode, load to failure, stiffness, femoral head rotation, femoral neck shortening and femoral head migration. Standardized Pauwels type 3 fractures (AO/OTA 31-B2) with comminution were created in 18 biomechanical sawbones using a custom-made sawguide. Fractures were stabilized using either SHS-Screw, SHS-Blade or Rotationally Stable Screw-Anchor (RoSA). Femurs were positioned in 25 degrees adduction and ten degrees posterior flexion and were cyclically loaded with an axial sinusoidal loading pattern of 0.5 Hz, starting with 300 N, with an increase by 300 N every 2000 cycles until bone-implant failure occurred. Mean failure load for the Screw-Anchor fixation (RoSA) was 5100 N (IQR 750 N), 3900 N (IQR 75 N) for SHS-Blade and 3000 N (IQR 675 N; p = 0.002) for SHS-Screw. For SHS-Screw and SHS-Blade we observed fracture displacement with consecutive fracture collapse as the main reason for failure, whereas RoSA mainly showed a cut-out under high loadings. Mean stiffness at 1800 N was 826 (IQR 431) N/mm for SHS-Screw, 1328 (IQR 441) N/mm for SHS-Blade and 1953 (IQR 617) N/mm for RoSA (p = 0.003). With a load of 1800 N (SHS-Screw 12° vs. SHS-Blade 7° vs. RoSA 2°; p = 0.003) and with 2700 N (24° vs. 15° vs. 3°; p = 0.002) the RoSA implants demonstrated a higher rotational stability and had the lowest femoral neck shortening (p = 0.002), compared with the SHS groups. At the 2700 N load point, RoSA systems showed a lower axial (p = 0.019) and cranial (p = 0.031) femoral head migration compared to the SHS-Screw. In our study, the new Screw-Anchor fixation (RoSA) was superior to the comparable SHS implants regarding rotational stability and femoral neck shortening. Failure load, stiffness, femoral head migration, and resistance to fracture displacement were in RoSA implants higher than in SHS-Screws, but without significance in comparison to SHS-Blades.

Management of Syndesmotic Ankle Injuries in Children and Adolescents.

PubMed

Shore, Benjamin J; Kramer, Dennis E

2016-06-01

Pediatric ankle injuries are common, especially in athletes; however, the incidence of syndesmosis injuries in children has been scarcely reported. Injuries to the ankle syndesmosis, termed "high ankle sprains," can affect high-level and recreational athletes and have been related to delayed return to play, persistent pain, and adult injuries have been associated with long-term disability. Syndesmotic injuries do occur in children, especially those who participate in sports that involve cutting and pivoting (football, soccer) or sports with rigid immobilization of the ankle (skiing, hockey). Unstable pediatric syndesmosis injuries requiring surgical fixation are often associated with concomitant fibular fracture in skeletally mature children. Physician vigilance and careful clinical examination coupled with appropriate radiographs can determine the extent of the injury in the majority of circumstances.

Fingering and fracturing during multiphase flow in porous media (Invited)

NASA Astrophysics Data System (ADS)

Juanes, R.

2013-12-01

The displacement of one fluid by another in a porous medium give rise to a rich variety of hydrodynamic instabilities. Beyond their scientific value as fascinating models of pattern formation, unstable porous-media flows are essential to understanding many natural and man-made processes, including water infiltration in the vadose zone, carbon dioxide injection and storage in deep saline aquifers, and hydrocarbon recovery. Here, we review the pattern-selection mechanisms of a wide spectrum of porous-media flows that develop hydrodynamic instabilities, discuss their origin and the mathematical models that have been used to describe them. We point out many challenges that remain to be resolved in the context of multiphase flows, and suggest modeling approaches that may offer new quantitative understanding.

The value of 'binder-off' imaging to identify occult and unexpected pelvic ring injuries.

PubMed

Fagg, James A C; Acharya, Mehool R; Chesser, Tim J S; Ward, Anthony J

2018-02-01

To determine the effectiveness of 'binder-off' plain pelvic radiographs in the assessment of pelvic ring injuries. All patients requiring operative intervention at our tertiary referral pelvic unit/major trauma centre for high-energy pelvic injuries between April 2012 and December 2014 were retrospectively identified. Pre-operative pelvic imaging with and without pelvic binder was reviewed with respect to fracture pattern and pelvic stability. The frequency with which the imaging without pelvic binder changed the opinion of the pelvic stability and need for operative intervention, when compared with the computed tomography (CT) scans and anteroposterior (AP) radiographs with the binder on, was assessed. Seventy-three percent (71 of 97) of patients had initial imaging with a pelvic binder in situ. Of these, 76% (54 of 71) went on to have 'binder-off' imaging. Seven percent (4 of 54) of patients had unexpected unstable pelvic ring injuries identified on 'binder-off' imaging that were not identified on CT imaging in binder. Trauma CT imaging of the pelvis with a pelvic binder in place is inadequate at excluding unstable pelvic ring injuries, and, based on the original findings in this paper, we recommend additional plain film 'binder-off' radiographs, when there is any clinical concern. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Utility of Local Anesthesia for Neurosurgical Interventions in a Low-Resource Setting: A Case Series.

PubMed

Eaton, Jessica; Hanif, Asma Bilal; Mzumara, Suzgisam; Charles, Anthony

2018-05-01

Trauma is a major contributor to global morbidity and mortality, and injury to the central nervous system is the most common cause of death in these patients. While the provision of surgical services is being recognized as essential to global public health efforts, specialty areas such as neurosurgery remain overlooked. This is a retrospective case review of patients with operable lesions, such as extra-axial hematomas and unstable depressed skull fractures that underwent neurosurgical interventions under local anesthesia. A total of 13 patients underwent neurosurgical intervention under local anesthesia. Two and three patients with burr hole decompression of epidural and subdural hematomas, respectively; seven patients had elevation of depressed skull fractures and lastly one patient had an aspiration of a brain abscess. All patients survived with and without residual neurological deficits. Access to resources and staff required to deliver general anesthesia is challenging in resource-poor settings. We have therefore begun performing emergent interventions under local anesthesia, with or without conscious sedation. While some patients had some minor residual weakness after the procedure, the degree of neurological deficit was improved from that observed before the procedure in all patients.

Predicting cancellous bone failure during screw insertion.

PubMed

Reynolds, Karen J; Cleek, Tammy M; Mohtar, Aaron A; Hearn, Trevor C

2013-04-05

Internal fixation of fractures often requires the tightening of bone screws to stabilise fragments. Inadequate application of torque can leave the fracture unstable, while over-tightening results in the stripping of the thread and loss of fixation. The optimal amount of screw torque is specific to each application and in practice is difficult to attain due to the wide variability in bone properties including bone density. The aim of the research presented in this paper is to investigate the relationships between motor torque and screw compression during powered screw insertion, and to evaluate whether the torque during insertion can be used to predict the ultimate failure torque of the bone. A custom test rig was designed and built for bone screw experiments. By inserting cancellous bone screws into synthetic, ovine and human bone specimens, it was established that variations related to bone density could be automatically detected through the effects of the bone on the rotational characteristics of the screw. The torque measured during screw insertion was found to be directly related to bone density and can be used, on its own, as a good predictor of ultimate failure torque of the bone. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Wing-augmentation reduces femoral head cutting out of dynamic hip screw.

PubMed

Chen, Chih-Yu; Huang, Shu-Wei; Sun, Jui-Sheng; Lin, Shin-Yiing; Yu, Chih-Sheng; Pan, Hsu-Pin; Lin, Ping-Hung; Hsieh, Fan-Chun; Tsuang, Yang-Hwei; Lin, Feng-Huei; Yang, Rong-Sen; Cheng, Cheng-Kung

2017-06-01

The dynamic hip screw (DHS) is commonly used in the treatment of femoral intertrochanteric fracture with high satisfactory results. However, post-operative failure does occur and result in poor prognosis. The most common failure is femoral head varus collapse, followed by lag screw cut-out through the femoral head. In this study, a novel-designed DHS with two supplemental horizontal blades was used to improve the fixation stability. In this study, nine convention DHS and 9 Orthopaedic Device Research Center (ODRC) DHSs were tested in this study. Each implant was fixed into cellular polyurethane rigid foam as a surrogate of osteoporotic femoral head. Under biaxial rocking motion, all constructs were loaded to failure point (12mm axial displacement) or up to 20,000 cycles of 1.45kN peak magnitude were achieved, whichever occurred first. The migration kinematics was continuously monitored and recorded. The final tip-to-apex distance, rotational angle and varus deformation were also recorded. The results showed that the ODRC DHS sustained significantly more loading cycles and exhibited less axial migration in comparison to the conventional DHS. The ODRC DHS showed a significantly smaller bending strain and larger torsional strain compared to the conventional DHS. The changes in tip-to-apex distance (TAD), post-study varus angle, post-study rotational angle of the ODRC DHS were all significantly less than that of the conventional DHS (p < 0.05). We concluded that the ODRC DHS augmented with two horizontal wings would increase the bone-implant interface contact surface, dissipate the load to the screw itself, which improves the migration resistance and increases the anti-rotational implant effect. In conclusion, the proposed ODRC DHS demonstrated significantly better migration resistance and anti-rotational effect in comparison to the conventional DHS construct. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Short Segment Spinal Instrumentation With Index Vertebra Pedicle Screw Placement for Pathologies Involving the Anterior and Middle Vertebral Column Is as Effective as Long Segment Stabilization With Cage Reconstruction: A Biomechanical Study.

PubMed

Bartanusz, Viktor; Harris, Jonathan; Moldavsky, Mark; Cai, Yiwei; Bucklen, Brandon

2015-11-01

An in vitro, cadaveric biomechanical study. The aim of the present study was to compare single-segment posterior instrumentation and fracture-level screws with single/multilevel posterior fixation and corpectomy in a simulated, unstable burst fracture model. The optimal extent of instrumentation for surgical cases of non-neoplastic vertebral body pathologies remains uncertain. Although several clinical studies demonstrate advantages of short segment instrumentation with index-level screws over more extensive corpectomy and anterior-posterior techniques, a comprehensive biomechanical comparison of these techniques is currently lacking. Six bovine spines (T11-L5) were tested in flexion, extension, lateral bending (LB), and axial rotation (AR) following simulated burst fracture at L2. Posterior instrumentation included 1 level above/below (1LF) and 2 levels above/below fracture level (2LF), intermediate or index screws at fracture level (FF), and cross-connectors above/below fracture level (CC). Anterior corpectomy devices included expandable corpectomy spacers with/without integrated screws, ACDi and ACD, respectively FORTIFY-Integrated/FORTIFY; Globus Medical, Inc., PA. Constructs were tested in the following order: (1) Intact; (2) 1LF; (3) 1LF and CC; (4) 1LF and FF; (5) 1LF, CC, and FF; (6) 2LF; (7) 2LF and CC; (8) 2LF and FF; (9) 2LF, CC, and FF; (10) 2LF and ACD; (11) 2LF, ACD, and CC; (12) 1LF and ACDi; (13) 1LF, ACDi, and CC. During flexion, all constructs except 1LF reduced motion relative to intact (P ≤ 0.05). Anterior support was most stable, but no differences were found between constructs (P ≥ 0.05). Every construct reduced motion in extension, though no differences were found between constructs and intact (P ≥ 0.05). During LB, all constructs reduced motion relative to intact (P ≤ 0.05); 2LF constructs further reduced motion (P ≤ 0.05). No construct returned AR motion to intact, with significant increases in 1LF and ACDi, 2LF and ACD, and 2LF, ACD, and CC (P ≤ 0.05). Cross-connectors and fracture screws reinforced each other in posterior-only constructs, providing maximum stability (P ≥ 0.05). This biomechanical comparison study found no significant superiority of combined anterior-posterior constructs over short segment fracture screw fixation, only multilevel posterior instrumentation with and without anterior support, providing increased stability in LB. Biomechanical equivalency suggests that short segment fracture screw intervention may provide appropriate stabilization for non-neoplastic pathologies involving the anterior and middle vertebral columns. 2.

[The occurance lead and cadmium in hip joint in aspect of exposure on tobacco smoke].

PubMed

Bogunia, Mariusz; Brodziak-Dopierała, Barbara; Kwapuliński, Jerzy; Ahnert, Bozena; Kowol, Jolanta; Nogaj, Ewa

2008-01-01

The objective of this study was qualification of content cadmium and lead in selected elements of the hip joint in aspect of tobacco smoking. The material for the research were 5 elements of hip joint (articular cartilage, trabecular bone and cortical bone femur head, fragment articular capsule and fragment trabecular bone from region intertrochanteric femoral bone), obtained intraoperatively during endoprothesoplastic surgeries. The samples come from habitants of Upper Silesian Region. Determination of trace elements contents were performed by ASA method (Pye Unicam SP-9) in acetylene-oxygen flame. Higher contents of lead were observed for smoking people, however in case of cadmium the differences of this element were not statistical essential between smokers and non-smokers.

The sinkhole of Schmalkalden, Germany - Imaging of near-surface subrosion structures and faults

NASA Astrophysics Data System (ADS)

Wadas, Sonja H.; Tschache, Saskia; Polom, Ulrich; Krawczyk, Charlotte M.

2017-04-01

In November 2010 a sinkhole of 30 m diameter and 20 m depth opened in a residential area in the village Schmalkalden, Germany, which fortunately led to damage of buildings and property only. The collapse was caused by leaching of soluble rocks in the subsurface, called subrosion. For an improved understanding of the processes leading to subrosion and sinkhole development a detailed characterization of the subsurface structures and elastic parameters is required. We used shear wave reflection seismic, which has proven to be a suitable method for high-resolution imaging of the near-surface. The village Schmalkalden is located in southern Thuringia in Germany. Since the Upper Cretaceous the area is dominated by fault tectonics, fractures and joints, which increase the rock permeability. The circulating groundwater leaches the Permian saline deposits in the subsurface and forms upward migrating cavities, which can develop into sinkholes, if the overburden collapses. In the direct vicinity of the backfilled sinkhole, five 2-D shear wave reflection seismic profiles with total length of ca. 900 m and a zero-offset VSP down to 150 m depth were acquired. For the surface profiles a 120-channel landstreamer attached with horizontal geophones and an electrodynamic micro-vibrator, exciting horizontally polarized shear waves, were used. For the VSP survey an oriented borehole probe equipped with a 3C-geophone and electrodynamic and hydraulic vibrators, exciting compression- and shear waves, were utilized. The seismic sections show high-resolution images from the surface to ca. 100 m depth. They display heterogeneous structures as indicated by strong vertical and lateral variations of the reflectors. In the near-surface, depressions are visible and zones of low seismic velocities < 180 m/s show increased attenuation of the seismic wave field. These are probably the result of the fractured underground, due to fault tectonics and the ongoing subrosion. The unstable zones are additionally characterized by a low shear modulus < 120 MPa, which is derived from density and shear wave interval velocities. The results from the 2-D reflection seismics are supplemented with results of a VSP survey in a borehole near the former sinkhole. The VSP data shows anomalies of the Vp-Vs ratio with values above 2,5. This indicates unstable zones correlated with the anomalies revealed by the 2-D sections. Possible factors for the development of the Schmalkalden sinkhole in 2010 are the presence of soluble Permian deposits, the strongly fractured underground and the identified faults.

Intra-pelvic pressure changes after pelvic fracture: A cadaveric study quantifying the effect of a pelvic binder and limb bandaging over a bolster.

PubMed

Morris, Rhys; Loftus, Andrew; Friedmann, Yasmin; Parker, Paul; Pallister, Ian

2017-04-01

Unstable pelvic fractures can be life-threatening due to catastrophic haemorrhage. Non-invasive methods of reducing and stabilising these injuries include pelvic binder application and also lower limb bandaging over a knee-flexion bolster. Both of these methods help close the pelvic ring and should tamponade bleeding. This study aimed to quantify the intra-pelvic pressure changes that occurred with 3 different manoeuvres: lower limb bandaging over a bolster; a Trauma Pelvic Orthotic Device (T-POD) pelvic binder, and a combination of both. Following a pilot study with 2 soft embalmed cadavers, a formal study with 6 unembalmed cadavers was performed. For each specimen an unstable pelvic injury was created (OA/OTA 61-C1) by dividing the pelvic ring anteriorly and posteriorly. A 3-4cm manometric water-filled balloon was placed in the retropubic space and connected to a 50ml syringe and water manometer via a 3-way tap. A baseline pressure of 8cmH 2 O (equating to the average central venous pressure) was used for each cadaver. Steady intra-pelvic pressures (more reliably reflecting the pressures achieved following an intervention) were used in the subsequent statistical analysis, using R statistical language and Rstudio. Paired t-test or Wilcoxon's rank sum test were used (depending on the normality of the dataset) to determine the impact of each intervention on the intra-pelvic pressure. The mean steady intra-pelvic pressures were significantly greater than the baseline pressure for each intervention. The binder and limb bandaging over a bolster alone increased the mean steady pelvic pressures significantly to 24 (SE=5) (p<0.036) and 15.5 (SE=2) (p<0.02)cmH 2 O respectively. Combining these interventions further increased the mean steady pressure to 31 (SE=7)cmH 2 O. However, this was not significantly greater than pressures for each of the individual interventions. Both lower limb bandaging over a bolster and pelvic binder application significantly increased intra-pelvic pressure above the baseline pressure. This was further increased through combining these interventions, which could be useful clinically to augment haemorrhage control in these fractures. Lower-limb bandaging over a bolster, and pelvic binder application, both significantly increased intra-pelvic pressures, and were greatest in combination. These findings support the use of these techniques to facilitate non-surgical haemorrhage control. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Biomechanical Study of Posteromedial Tibial Plateau Fracture Stability: Do They All Require Fixation?

PubMed

Cuéllar, Vanessa G; Martinez, Danny; Immerman, Igor; Oh, Cheongeun; Walker, Peter S; Egol, Kenneth A

2015-07-01

Although the posteromedial fragment in tibial plateau fractures is often considered unstable, biomechanical evidence supporting this view is lacking. We aimed to evaluate the stability of the fragment in a cadaver model. Our hypothesis was that under the expected small axial force during rehabilitation and the combined effects of this force with shear force, internal rotation torque, and varus moment, the most common posteromedial tibial fragment morphology could maintain stability in early flexion. Axial compression force alone or combined with posterior shear, internal rotation torque, or varus moment was applied to the femurs of 5 fresh cadaveric knees. A Tekscan pressure mapping system was used to measure pressure and contact area between the femoral condyles, meniscus, and tibial plateau. A Microscribe 3D digitizer was used to define the 3-dimensional positions of the femur and tibia. A 10-mm and then a 20-mm osteotomy was created with a saw at an angle of 30 degrees in the axial plane with respect to the tangent of the posterior tibial plateau and 75 degrees in the sagittal plane, representing a typical posteromedial fracture fragment. At each flexion angle (15, 30, 60, 90, and 120 degrees) and loading condition (axial compression only, compression with shear force, torque, and varus moment), distal displacement of the medial femoral condyle and the tibial fracture fragments was determined. For the 10-mm fragment, medial femoral condyle displacement was little affected up to approximately 30-degree flexion, after which it increased. For the 20-mm fragment, there was progressive medial femoral condyle displacement with increasing flexion from baseline. However, for the 10- and 20-mm fragments themselves, displacements were noted at every flexion angle, starting at 1.7 mm inferior displacement with 15 degrees of flexion and internal rotation torque and up to 10.2 mm displacement with 90 degrees of flexion and varus bending moment. In this cadaveric model of a posteromedial tibial plateau fracture, both fracture fragments studied displaced with knee flexion, even at low flexion angles. Although such fragments may initially seem nondisplaced after injury, posteromedial fragments similar to these tested are likely to displace during knee range of motion exercises in non-weight-bearing conditions.

Surgical treatment of multiple rib fractures and flail chest in trauma: a one-year follow-up study.

PubMed

Caragounis, Eva-Corina; Fagevik Olsén, Monika; Pazooki, David; Granhed, Hans

2016-01-01

Multiple rib fractures and unstable thoracic cage injuries are common in blunt trauma. Surgical management of rib fractures has received increasing attention in recent years and the aim of this 1-year, prospective study was to assess the long-term effects of surgery. Fifty-four trauma patients with median Injury Severity Score 20 (9-66) and median New Injury Severity Score 34 (16-66) who presented with multiple rib fractures and flail chest, and underwent surgical stabilization with plate fixation were recruited. Patients responded to a standardized questionnaire concerning pain, local discomfort, breathlessness and use of analgesics and health-related quality of life (EQ-5D-3 L) questionnaire at 6 weeks, 3 months, 6 months and 1 year. Lung function, breathing movements, range of motion and physical function were measured at 3 months, 6 months and 1 year. Symptoms associated with pain, breathlessness and use of analgesics significantly decreased from 6 weeks to 1 year following surgery. After 1 year, 13 % of patients complained of pain at rest, 47 % had local discomfort and 9 % used analgesics. The EQ-5D-3 L index increased from 0.78 to 0.93 and perceived overall health state increased from 60 to 90 % (p < 0.0001) after 6 weeks to 1 year. Lung function improved significantly with predicted Forced vital capacity and Peak expiratory flow increasing from 86 to 106 % (p = 0.0002) and 81 to 110 % (p < 0.0001), respectively, from 3 months to 1 year after surgery. Breathing movements and range of motion tended to improve over time. Physical function improved significantly over time and the median Disability rating index was 0 after 1 year. Patients with multiple rib fractures and flail chest show a gradual improvement in symptoms associated with pain, quality of life, mobility, disability and lung function over 1 year post surgery. Therefore, the final outcome of surgery cannot be assessed before 1 year post-operatively.

Evolution of a Multidisciplinary Clinical Pathway for the Management of Unstable Patients With Pelvic Fractures

PubMed Central

Biffl, Walter L.; Smith, Wade R.; Moore, Ernest E.; Gonzalez, Ricardo J.; Morgan, Steven J.; Hennessey, Theresa; Offner, Patrick J.; Ray, Charles E.; Franciose, Reginald J.; Burch, Jon M.

2001-01-01

Objective To determine whether the evolution of the authors’ clinical pathway for the treatment of hemodynamically compromised patients with pelvic fractures was associated with improved patient outcome. Summary Background Data Hemodynamically compromised patients with pelvic fractures present a complex challenge. The multidisciplinary trauma team must control hemorrhage, restore hemodynamics, and rapidly identify and treat associated life-threatening injuries. The authors developed a clinical pathway consisting of five primary elements: immediate trauma attending surgeon’s presence in the emergency department, early simultaneous transfusion of blood and coagulation factors, prompt diagnosis and management of associated life-threatening injuries, stabilization of the pelvic girdle, and timely insinuation of pelvic angiography and embolization. The addition of two orthopedic pelvic fracture specialists led to a revision of the pathway, emphasizing immediate emergency department presence of the orthopedic trauma attending to provide joint decision making with the trauma surgeon, closing the pelvic volume in the emergency department, and using alternatives to traditional external fixation devices. Methods Using trauma registry and blood bank records, the authors identified pelvic fracture patients receiving blood transfusions in the emergency department. They analyzed patients treated before versus after the May 1998 revision of the clinical pathway. Results A higher proportion of patients in the late period had blood pressure less than 90 mmHg (52% vs. 35%). In the late period, diagnostic peritoneal lavage was phased out in favor of torso ultrasound as a primary triage tool, and pelvic binding and C-clamp application largely replaced traditional external fixation devices. The overall death rate decreased from 31% in the early period to 15% in the later period, as did the rate of deaths from exsanguination (9% to 1%), multiple organ failure (12% to 1%), and death within 24 hours (16% to 5%). Conclusions The evolution of a multidisciplinary clinical pathway, coordinating the resources of a level 1 trauma center and directed by joint decision making between trauma surgeons and orthopedic traumatologists, has resulted in improved patient survival. The primary benefits appear to be in reducing early deaths from exsanguination and late deaths from multiple organ failure. PMID:11407336

The Ghost in the Machine: Fracking in the Earth's Complex Brittle Crust

NASA Astrophysics Data System (ADS)

Malin, P. E.

2015-12-01

This paper discusses in the impact of complex rock properties on practical applications like fracking and its associated seismic emissions. A variety of borehole measurements show that the complex physical properties of the upper crust cannot be characterized by averages on any scale. Instead they appear to follow 3 empirical rule: a power law distribution in physical scales, a lognormal distribution in populations, and a direct relation between changes in porosity and log(permeability). These rules can be directly related to the presence of fluid rich and seismically active fractures - from mineral grains to fault segments. (These are the "ghosts" referred to in the title.) In other physical systems, such behaviors arise on the boundaries of phase changes, and are studied as "critical state physics". In analogy to the 4 phases of water, crustal rocks progress upward from a un-fractured, ductile lower crust to nearly cohesionless surface alluvium. The crust in between is in an unstable transition. It is in this layer methods such as hydrofracking operate - be they in Oil and Gas, geothermal, or mining. As a result, nothing is predictable in these systems. Crustal models have conventionally been constructed assuming that in situ permeability and related properties are normally distributed. This approach is consistent with the use of short scale-length cores and logs to estimate properties. However, reservoir-scale flow data show that they are better fit to lognormal distributions. Such "long tail" distributions are observed for well productivity, ore vein grades, and induced seismic signals. Outcrop and well-log data show that many rock properties also show a power-law-type variation in scale lengths. In terms of Fourier power spectra, if peaks per km is k, then their power is proportional to 1/k. The source of this variation is related to pore-space connectivity, beginning with grain-fractures. We then show that a passive seismic method, Tomographic Fracture ImagingTM (TFI), can observe the distribution of this connectivity. Combined with TFI data, our fracture-connectivity model reveals the most significant crustal features and account for their range of passive and stimulated behaviors.

Bladder incarceration following anterior pelvic infix of a traumatic pubic symphysis diastasis treated with immediate open reduction and internal fixation.

PubMed

Jain, Mantu; Nanda, Saurav Narayan; Mohapatra, Soumya Shrikanta; Samal, Barada Prasanna

2017-08-01

Stabilization after a pelvic fracture can be accomplished using multiple techniques. The anterior external fixator has been traditionally used in variety of unstable pelvis either singly or in combination of posterior screws. These devices are cumbersome and restrict side turning and sitting particularly in obese patients. An alternative, anterior subcutaneous pelvic internal fixation technique (ASPIF) was developed which is well tolerated by patients for mobility and comfort and biomechanically more stable construct Complications of this construct included irritation of the lateral femoral cutaneous nerve, femoral nerve palsy &heterotypic ossification with reduced rates of infections and aseptic loosening as compared to external fixator. Bladder incarceration following treatment has never been reported and we encountered such a problem during management which we want to highlight.

Upper ankle joint space detection on low contrast intraoperative fluoroscopic C-arm projections

NASA Astrophysics Data System (ADS)

Thomas, Sarina; Schnetzke, Marc; Brehler, Michael; Swartman, Benedict; Vetter, Sven; Franke, Jochen; Grützner, Paul A.; Meinzer, Hans-Peter; Nolden, Marco

2017-03-01

Intraoperative mobile C-arm fluoroscopy is widely used for interventional verification in trauma surgery, high flexibility combined with low cost being the main advantages of the method. However, the lack of global device-to- patient orientation is challenging, when comparing the acquired data to other intrapatient datasets. In upper ankle joint fracture reduction accompanied with an unstable syndesmosis, a comparison to the unfractured contralateral site is helpful for verification of the reduction result. To reduce dose and operation time, our approach aims at the comparison of single projections of the unfractured ankle with volumetric images of the reduced fracture. For precise assessment, a pre-alignment of both datasets is a crucial step. We propose a contour extraction pipeline to estimate the joint space location for a prealignment of fluoroscopic C-arm projections containing the upper ankle joint. A quadtree-based hierarchical variance comparison extracts potential feature points and a Hough transform is applied to identify bone shaft lines together with the tibiotalar joint space. By using this information we can define the coarse orientation of the projections independent from the ankle pose during acquisition in order to align those images to the volume of the fractured ankle. The proposed method was evaluated on thirteen cadaveric datasets consisting of 100 projections each with manually adjusted image planes by three trauma surgeons. The results show that the method can be used to detect the joint space orientation. The correlation between angle deviation and anatomical projection direction gives valuable input on the acquisition direction for future clinical experiments.

Managing type II and type IV Lauge-Hansen supination external rotation ankle fractures: current orthopaedic practice.

PubMed

Kosuge, D D; Mahadevan, D; Chandrasenan, J; Pugh, H

2010-11-01

Differentiating supination external rotation (SER) type II and IV ankle injuries is challenging in the absence of a medial malleolar fracture or talar shift on radiographs. The accurate differentiation between a stable SER-II from an unstable SER-IV injury would allow implementation of the appropriate management plan from diagnosis. The aim of this study was to ascertain the practice of orthopaedic surgeons in dealing with these injuries. A postal survey was undertaken on 216 orthopaedic consultants from three regions. In the presence of medial-sided clinical signs (tenderness, swelling, ecchymosis), 22% of consultants would perform surgical fixation. 53% would choose non-operative treatment and the majority would monitor these fractures through serial radiographs. The remaining 25% of consultants would perform an examination under anaesthesia (EUA; 15%), request stress radiographs (9%) or an MRI scan (1%). Without medial-sided signs, 85% would advocate non-operative treatment and, of these, 74% would perform weekly radiographs. Interestingly, 6% would perform immediate surgical fixation. Stress radiographs (6%) and EUAs (2%) were advocated in the remaining group of consultants. Foot and ankle surgeons utilised stress radiographs more frequently and were more likely to proceed to surgical fixation should talar shift be demonstrated. Clinical practice is varied amongst the orthopaedic community. This may lead to unnecessary surgery in SER-II injuries and delay in diagnosis and operative management of SER-IV injuries. We have highlighted the various investigative modalities available that may be used in conjunction with clinical signs to make a more accurate diagnosis.

Using glass-graded zirconia to increase delamination growth resistance in porcelain/zirconia dental structures.

PubMed

Chai, Herzl; Mieleszko, Adam J; Chu, Stephen J; Zhang, Yu

2018-01-01

Porcelain fused to zirconia (PFZ) restorations are widely used in prosthetic dentistry. However, their tendency to delaminate along the P/Z interface remains a practical problem so that assessing and improving the interfacial strength are important design aspects. This work examines the effect of modifying the zirconia veneering surface with an in-house felspathic glass on the interfacial fracture resistance of fused P/Z. Three material systems are studied: porcelain fused to zirconia (control) and porcelain fused to glass-graded zirconia with and without the presence of a glass interlayer. The specimens were loaded in a four-point-bend fixture with the porcelain veneer in tension. The evolution of damage is followed with the aid of a video camera. The interfacial fracture energy G C was determined with the aid of a FEA, taking into account the stress shielding effects due to the presence of adjacent channel cracks. Similarly to a previous study on PFZ specimens, the fracture sequence consisted of unstable growth of channel cracks in the veneer followed by stable cracking along the P/Z interface. However, the value of GC for the graded zirconia was approximately 3 times that of the control zirconia, which is due to the good adhesion between porcelain and the glass network structure on the zirconia surface. Combined with its improved bonding to resin-based cements, increased resistance to surface damage and good esthetic quality, graded zirconia emerges as a viable material concept for dental restorations. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Life cycle of a geyser discharge apron: Evidence from Waikite Geyser, Whakarewarewa geothermal area, North Island, New Zealand

NASA Astrophysics Data System (ADS)

Jones, Brian; Renaut, Robin W.; Owen, R. Bernhart

2011-05-01

Waikite, a geyser located in the Whakarewarewa geothermal area on the North Island, New Zealand, has a history of eruptive-dormancy cycles that have been attributed to natural and anthropogenic causes. The last cycle involved an active period from ~ 1932 to 1968/69 that was followed by a period of dormancy that continues today. Such cycles are important because they control the temporal development of the discharge apron. When the geyser is active, growth of the discharge apron is dictated by the precipitation of opal-A, which is controlled by factors such as discharge patterns, water chemistry, pH, temperature, rate of cooling, and the resident microbiota. With dormancy, conditions change radically because water no longer flows down the discharge apron. Instead, the discharge apron lapses into a phase of degradation that, on Waikite, is evident from (1) deflation of the apron surface, (2) blocks splaying off the apron margins along margin-parallel fractures, (3) tension fractures, (4) saucer-shaped collapse zones, (5) increasingly unstable surfaces resulting from subsurface opal-A dissolution, (6) fractures, from which steam and other gases emanate, and (7) incursion of native vegetation around the edge of the apron and on the distal parts of the discharge apron. When the geyser becomes active again, silica precipitation will resume and the discharge apron will once again accrete vertically and expand laterally. Analysis of the Waikite system shows that successions that develop on geyser discharge aprons are formed of unconformity-bounded packages of sinter that reflect the eruptive-dormancy history of the parent geyser.

Sublaminar fixation for traumatic lumbar fracture subluxation with lateral listhesis in a 2-year-old patient.

PubMed

Yanni, Daniel S; Cruz, Aurora S; Halim, Alexander Y; Gill, Amandip S; Muhonen, Michael G; Heary, Robert F; Goldstein, Ira M

2018-05-04

Pediatric spinal trauma can present a surgeon with difficult management decisions given the rarity of these cases, pediatric anatomy, and a growing spine. The need to stabilize a traumatically unstable pediatric spine can be an operative challenge given the lack of instrumentation available. The authors present a surgical technique and an illustrative case that may offer a novel, less disruptive method of stabilization. A 2-year-old girl presented after an assault with an L1-2 fracture subluxation with lateral listhesis and fractured jumped facets exhibited on CT scans. CT also showed intact growth plates at the vertebral body, pedicles, and posterior elements. MRI showed severe ligamentous injury, conus medullaris compression, and an epidural hematoma. Neurologically, the patient moved both lower extremities asymmetrically. Given the severity of the deformity and neurological examination and disruption of the stabilizing structures, the authors made the decision to surgically decompress the L-1 and L-2 segments with bilateral laminotomies, evacuate the epidural hematoma, and reduce the deformity with sublaminar stabilization using braided polyester cables bilaterally, thus preserving the growth plates. They also performed a posterolateral onlay fusion at L-1 and L-2 using autograft and allograft placed due to the facet disruption. At the 42-month follow-up, imaging showed fusion of L-1 and L-2 with good alignment, and the hardware was subsequently explanted. The patient was neurologically symmetric in strength, ambulating, and had preserved alignment. Her bones and spinal canal continued to grow in relation to the other levels.

Anterior transarticular C1-C2 fixation with contralateral screw insertion: a report of two cases and technical note.

PubMed

Lvov, Ivan; Grin, Andrey; Kaykov, Aleksandr; Smirnov, Vladimir; Krylov, Vladimir

2017-08-08

Anterior transarticular fixation of the C1-C2 vertebrae is a well-known technique that involves screw insertion through the body of the C2 vertebra into the lateral masses of the atlas through an anterior transcervical approach. Meanwhile, contralateral screw insertion has been previously described only in anatomical studies. We describe two case reports of the clinical application of this new technique. In Case 1, the patient was diagnosed with an unstable C1 fracture. The clinical features of the case did not allow for any type of posterior atlantoaxial fusion, Halo immobilization, or routine anterior fixation using the Reindl and Koller techniques. The possible manner of screw insertion into the anterior third of the right lateral mass was via a contralateral trajectory, which was performed in this case. Case 2 involved a patient with neglected posteriorly dislocated dens fracture who could not lie in the prone position due to concomitant cardiac pathology. Reduction of atlantoaxial dislocation was insufficient, even after scar tissue resection at the fracture, while transdental fusion was not possible. Considering the success of the previous case, atlantoaxial fixation was performed through the small approach, using the Reindl technique and contralateral screw insertion. These two cases demonstrate the potential of anterior transarticular fixation of C1-C2 vertebrae in cases where posterior atlantoaxial fusion is not achievable. This type of fixation can be performed through a single approach if one screw is inserted using the Reindl technique and another is inserted via a contralateral trajectory.

New observations on mid-plate volcanism and the tectonic history of the Pacific plate, Tahiti to Easter microplate

NASA Astrophysics Data System (ADS)

Searle, R. C.; Francheteau, J.; Cornaglia, B.

1995-04-01

We describe the geology and tectonics of a continuous swathe of seafloor between Tahiti and the western edge of the Easter microplate imaged by GLORIA and Sea Beam on two separate cruise transits in 1987 and 1988. The data reveal that mid-plate volcanism is common in this region, even on deep seafloor hundreds of kilometres from major lines of seamounts and islands. This supports the idea of a thin weak lithosphere over the Pacific Superswell, and the idea that the tops of major mantle plumes may spread out over diameters of the order of 1000 km. The mid-plate volcanism occurs in two distinct forms. Over most of our traverse it appears as fields of relatively young and acoustically strongly backscattering lava flows, often accompanied by groups of numerous small, circular volcanoes. East of 122° W (about chron 5A), however, we observed a distinct form: major, sharp-crested, constructional volcanic ridges, many tens of kilometres long, individually trending ENE, but lying en-echelon along an E-W regional trend. These ridges appear morphologically identical to the 'cross-grain ridges' seen elsewhere in the Pacific. We attribute their formation to magma supplied from the regionally hot mantle leaking along tectonic lines of weakness. However, although these ridges are parallel to fracture zone trends seen farther west, they are morphologically very different from any known fracture zone. Moreover, individual ridges are somewhat oblique to the tectonic spreading fabric around them, and so do not seem to follow actual fracture zone traces. The whole line of en-echelon ridges lies along part of the predicted trace of Fracture Zone 2 of Okal and Cazenave [15], and is probably its morphological expression. However, nowhere did we see a convincing 'conventional' fracture zone trace in or following the predicted position or orientation. We suggest instead that magma from an independent source has used lines of weakness along minor fracture zones to produce these en-echelon features. The Austral Fracture Zone is the only major fracture zone crossed in our transit, and here is characterised by four fossil transform strands. Its marked position on the AAPG and GEBCO maps is found to be in error. Finally, we found that the expected change from NNW- to NNE-trending spreading fabric at chron 6C did not occur in a clear-cut way, as predicted by earlier tectonic histories of the Pacific. Instead, the post-chron 6C fabric oscillates in a confused way between NNE and NNW, suggesting to us that this area has been characterised by an unstable plate boundary, probably associated with a succession of propagating rifts or microplates from chron 6C to the present.

A comparative biomechanical analysis of implants for the stabilization of proximal humerus fractures.

PubMed

Füchtmeier, B; May, R; Fierlbeck, J; Hammer, J; Nerlich, M

2006-01-01

A new humerus nail (Sirus) has become available for the treatment of fractures of the proximal humerus. The aim of the study was the biomechanical comparison of this implant with established systems. 12 matched pairs of human humeri were employed for testing. Three randomized groups were formed (n = 4 pairs). A bending moment of 7.5 Nm and a torsional moment of 8.3 Nm were applied in a test of five loading cycles to all intact bones. Loading was consistently initiated at the distal epiphysis. The consequent deformation at the distal epiphysis was continuously recorded. Then an osteotomy with a defect of 5 mm was created to simulate an unstable subcapital humerus fracture. For paired comparison, one of each pair was stabilized with the Sirus proximal humerus nail. The other side was fixed with a reference implant. The following groups were created.: Group I: Sirus versus Proximal humerus nail (PHN) with spiral blade. Group II: Sirus versus PHILOS plate. Group III: Sirus versus 4.5 mm AO T-plate. The proximal humerus nail (Sirus) demonstrated significantly higher stiffness values than the reference implants for both bending and torsional load. The following values were recorded at a bending moment of 7.5 Nm: Sirus 14.2 mm, PHN 20.7 mm, PHILOS plate 28.1 mm, 4.5 AO T-plate 29.3 mm p < 0.0012). The values at 8.3 Nm torsional moment were: Sirus 8.5 degrees , PHN 12.3 degrees , PHILOS plate 16.4 degrees , 4.5 AO T-Platte 15.6 degrees (p < 0.002). The intramedullary load carriers were biomechanically superior when compared to the plating systems in the fracture model presented here. Supplementary, the Sirus Nail showed higher stiffness values than the PHN. However, the latter are gaining in importance due to the possibility of minimal invasive implantation. Whether this will be associated with functional advantages requires further clinical investigation.

Intraoperative assessment of the stability of the distal tibiofibular joint in supination-external rotation injuries of the ankle: sensitivity, specificity, and reliability of two clinical tests.

PubMed

Pakarinen, Harri; Flinkkilä, Tapio; Ohtonen, Pasi; Hyvönen, Pekka; Lakovaara, Martti; Leppilahti, Juhana; Ristiniemi, Jukka

2011-11-16

This study was designed to assess the sensitivity, specificity, and interobserver reliability of the hook test and the stress test for the intraoperative diagnosis of instability of the distal tibiofibular joint following fixation of ankle fractures resulting from supination-external rotation forces. We conducted a prospective study of 140 patients with an unstable unilateral ankle fracture resulting from a supination-external rotation mechanism (Lauge-Hansen SE). After internal fixation of the malleolar fracture, a hook test and an external rotation stress test under fluoroscopy were performed independently by the lead surgeon and assisting surgeon, followed by a standardized 7.5-Nm external rotation stress test of each ankle under fluoroscopy. A positive stress test result was defined as a side-to-side difference of >2 mm in the tibiotalar or the tibiofibular clear space on mortise radiographs. The sensitivity and specificity of each test were calculated with use of the standardized 7.5-Nm external rotation stress test as a reference. Twenty-four (17%) of the 140 patients had a positive standardized 7.5-Nm external rotation stress test after internal fixation of the malleolar fracture. The hook test had a sensitivity of 0.25 (95% confidence interval, 0.12 to 0.45) and a specificity of 0.98 (95% confidence interval, 0.94 to 1.0) for the detection of the same instabilities. The external rotation stress test had a sensitivity of 0.58 (95% confidence interval, 0.39 to 0.76) and a specificity of 0.96 (95% confidence interval, 0.90 to 0.98). Both tests had excellent interobserver reliability, with 99% agreement for the hook test and 98% for the stress test. Interobserver agreement for the hook test and the clinical stress test was excellent, but the sensitivity of these tests was insufficient to adequately detect instability of the syndesmosis intraoperatively.

A prospective randomised controlled trial of the fibular nail versus standard open reduction and internal fixation for fixation of ankle fractures in elderly patients.

PubMed

White, T O; Bugler, K E; Appleton, P; Will, E; McQueen, M M; Court-Brown, C M

2016-09-01

The fundamental concept of open reduction and internal fixation (ORIF) of ankle fractures has not changed appreciably since the 1960s and, whilst widely used, is associated with complications including wound dehiscence and infection, prominent hardware and failure. Closed reduction and intramedullary fixation (CRIF) using a fibular nail, wires or screws is biomechanically stronger, requires minimal incisions, and has low-profile hardware. We hypothesised that fibular nailing in the elderly would have similar functional outcomes to standard fixation, with a reduced rate of wound and hardware problems. A total of 100 patients (25 men, 75 women) over the age of 65 years with unstable ankle fractures were randomised to undergo standard ORIF or fibular nailing (11 men and 39 women in the ORIF group, 14 men and 36 women in the fibular nail group). The mean age was 74 years (65 to 93) and all patients had at least one medical comorbidity. Complications, patient related outcome measures and cost-effectiveness were assessed over 12 months. Significantly fewer wound infections occurred in the fibular nail group (p = 0.002). At one year, there was no evidence of difference in mean functional scores (Olerud and Molander Scores 63; 30 to 85, versus 61; 10 to 35, p = 0.61) or scar satisfaction. The overall cost of treatment in the fibular nail group was £91 less than in the ORIF group despite the higher initial cost of the implant. We conclude that the fibular nail allows accurate reduction and secure fixation of ankle fractures, with a significantly lower rate of soft-tissue complications, and is more cost-effective than ORIF. Cite this article: Bone Joint J 2016;98-B:1248-52. ©2016 The British Editorial Society of Bone & Joint Surgery.

Detecting active pelvic arterial haemorrhage on admission following serious pelvic fracture in multiple trauma patients.

PubMed

Brun, Julien; Guillot, Stéphanie; Bouzat, Pierre; Broux, Christophe; Thony, Frédéric; Genty, Céline; Heylbroeck, Christophe; Albaladejo, Pierre; Arvieux, Catherine; Tonetti, Jérôme; Payen, Jean-Francois

2014-01-01

The early diagnosis of pelvic arterial haemorrhage is challenging for initiating treatment by transcatheter arterial embolization (TAE) in multiple trauma patients. We use an institutional algorithm focusing on haemodynamic status on admission and on a whole-body CT scan in stabilized patients to screen patients requiring TAE. This study aimed to assess the effectiveness of this approach. This retrospective cohort study included 106 multiple trauma patients admitted to the emergency room with serious pelvic fracture [pelvic abbreviated injury scale (AIS) score of 3 or more]. Of the 106 patients, 27 (25%) underwent pelvic angiography leading to TAE for active arterial haemorrhage in 24. The TAE procedure was successful within 3h of arrival in 18 patients. In accordance with the algorithm, 10 patients were directly admitted to the angiography unit (n=8) and/or operating room (n=2) for uncontrolled haemorrhagic shock on admission. Of the remaining 96 stabilized patients, 20 had contrast media extravasation on pelvic CT scan that prompted pelvic angiography in 16 patients leading to TAE in 14. One patient underwent a pelvic angiography despite showing no contrast media extravasation on pelvic CT scan. All 17 stabilized patients who underwent pelvic angiography presented a more severely compromised haemodynamic status on admission, and they required more blood products during their initial management than the 79 patients who did not undergo pelvic angiography. The incidence of unstable pelvic fractures was however comparable between the two groups. Overall, haemodynamic instability and contrast media extravasation on the CT-scan identified 26 out of the 27 patients who required subsequent pelvic angiography leading to TAE in 24. An algorithm focusing on haemodynamic status on arrival and on the whole-body CT scan in stabilized patients may be effective at triaging multiple trauma patients with serious pelvic fractures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Prevalence of sacral dysmorphia in a prospective trauma population: Implications for a "safe" surgical corridor for sacro-iliac screw placement

PubMed Central

2011-01-01

Background Percutaneous sacro-iliac (SI) screw fixation represents a widely used technique in the management of unstable posterior pelvic ring injuries and sacral fractures. The misplacement of SI-screws under fluoroscopic guidance represents a critical complication for these patients. This study was designed to determine the prevalence of sacral dysmorphia and the radiographic anatomy of surgical S1 and S2 corridors in a representative trauma population. Methods Prospective observational cohort study on a consecutive series of 344 skeletally mature trauma patients of both genders enrolled between January 1, 2007, to September 30, 2007, at a single academic level 1 trauma center. Inclusion criteria included a pelvic CT scan as part of the initial diagnostic trauma work-up. The prevalence of sacral dysmorphia was determined by plain radiographic pelvic films and CT scan analysis. The anatomy of sacral corridors was analyzed on 3 mm reconstruction sections derived from multislice CT scan, in the axial, coronal, and sagittal plane. "Safe" potential surgical corridors at S1 and S2 were calculated based on these measurements. Results Radiographic evidence of sacral dysmorphia was detected in 49 patients (14.5%). The prevalence of sacral dysmorphia was not significantly different between male and female patients (12.2% vs. 19.2%; P = 0.069). In contrast, significant gender-related differences were detected with regard to radiographic analysis of surgical corridors for SI-screw placement, with female trauma patients (n = 99) having significantly narrower corridors at S1 and S2 in all evaluated planes (axial, coronal, sagittal), compared to male counterparts (n = 245; P < 0.01). In addition, the mean S2 body height was higher in dysmorphic compared to normal sacra, albeit without statistical significance (P = 0.06), implying S2 as a safe surgical corridor of choice in patients with sacral dysmorphia. Conclusions These findings emphasize a high prevalence of sacral dysmorphia in a representative trauma population and imply a higher risk of SI-screw misplacement in female patients. Preoperative planning for percutaneous SI-screw fixation for unstable pelvic and sacral fractures must include a detailed CT scan analysis to determine the safety of surgical corridors. PMID:21569232

Prevalence of sacral dysmorphia in a prospective trauma population: Implications for a "safe" surgical corridor for sacro-iliac screw placement.

PubMed

Hasenboehler, Erik A; Stahel, Philip F; Williams, Allison; Smith, Wade R; Newman, Justin T; Symonds, David L; Morgan, Steven J

2011-05-10

Percutaneous sacro-iliac (SI) screw fixation represents a widely used technique in the management of unstable posterior pelvic ring injuries and sacral fractures. The misplacement of SI-screws under fluoroscopic guidance represents a critical complication for these patients. This study was designed to determine the prevalence of sacral dysmorphia and the radiographic anatomy of surgical S1 and S2 corridors in a representative trauma population. Prospective observational cohort study on a consecutive series of 344 skeletally mature trauma patients of both genders enrolled between January 1, 2007, to September 30, 2007, at a single academic level 1 trauma center. Inclusion criteria included a pelvic CT scan as part of the initial diagnostic trauma work-up. The prevalence of sacral dysmorphia was determined by plain radiographic pelvic films and CT scan analysis. The anatomy of sacral corridors was analyzed on 3 mm reconstruction sections derived from multislice CT scan, in the axial, coronal, and sagittal plane. "Safe" potential surgical corridors at S1 and S2 were calculated based on these measurements. Radiographic evidence of sacral dysmorphia was detected in 49 patients (14.5%). The prevalence of sacral dysmorphia was not significantly different between male and female patients (12.2% vs. 19.2%; P = 0.069). In contrast, significant gender-related differences were detected with regard to radiographic analysis of surgical corridors for SI-screw placement, with female trauma patients (n = 99) having significantly narrower corridors at S1 and S2 in all evaluated planes (axial, coronal, sagittal), compared to male counterparts (n = 245; P < 0.01). In addition, the mean S2 body height was higher in dysmorphic compared to normal sacra, albeit without statistical significance (P = 0.06), implying S2 as a safe surgical corridor of choice in patients with sacral dysmorphia. These findings emphasize a high prevalence of sacral dysmorphia in a representative trauma population and imply a higher risk of SI-screw misplacement in female patients. Preoperative planning for percutaneous SI-screw fixation for unstable pelvic and sacral fractures must include a detailed CT scan analysis to determine the safety of surgical corridors.

Internal versus external fixation of the anterior component in unstable fractures of the pelvic ring: pooled results from a systematic review.

PubMed

Wardle, B; Eslick, G D; Sunner, P

2016-10-01

Improving reduction of the pelvic ring improves long-term functional outcomes for patients. It has been demonstrated that posterior internal fixation is necessary to adequately control fractures to the posterior ring and there is evidence that supplementing this with fixation of the anterior ring improves stability. It is accepted that internal fixation provides greater stability than external fixation of the anterior ring but long-term differences in radiographic and functional outcomes have not yet been quantified. A search of electronic databases, reference lists and review articles from 1989 to 2015 yielded 18 studies (n = 884) that met our inclusion criteria. We included studies that discussed pelvic ring injuries in adults, reported functional or radiological outcomes or complications by anterior ring intervention and exceeded 14 patients. We excluded biomechanical and cadaver studies. Internal fixation of the anterior pelvic ring had better functional and radiographic outcomes. Residual displacement of >10 mm was less common with internal fixation (ER 0.12, 95 % CI 0.06-0.24) than external fixation (ER 0.31, 95 % CI 0.11-0.62). Unsatisfactory outcomes also occurred at a lower rate (ER 0.09, 95 % CI 0.03-0.22) compared to external fixation (ER 0.32, 95 % CI 0.18-0.50). Losses of reduction (ER 0.02, 95 % CI 0.01-0.04 versus ER 0.07, 95 % CI 0.02-0.21), malunions (ER 0.03, 95 % CI 0.01-0.08 versus ER 0.07, 95 % CI 0.02-0.21) and delayed/non-unions (ER 0.02, 95 % CI 0.01-0.05 versus ER 0.04, 95 % CI 0.02-0.07). Internal fixation of the anterior pelvic ring as supplementary fixation for unstable injuries to the pelvic ring appears to result in better radiographic and functional outcomes as well as fewer complications. However, data that separated outcomes and complications in relation to interventions of the anterior pelvic ring were limited. More studies looking specifically at outcomes in relation to the type of anterior ring intervention are needed.

Open MR imaging in spine surgery: experimental investigations and first clinical experiences.

PubMed

Verheyden, P; Katscher, S; Schulz, T; Schmidt, F; Josten, C

1999-01-01

The latest open MRI technology allows to perform open and closed surgical procedures under real-time imaging. Before performing spinal trauma surgery preclinical examinations had to be done to evaluate the artifacts caused by the implants. The MRT presented is a prototype developed by GE. Two vertically positioned magnetic coils are installed in an operation theater. By that means two surgeons are able to access the patient between the two coils. Numerous tests regarding the material of instruments and implants were necessary in advance. The specific size of the artifact depending on the pulse sequence and the positioning within the magnetic field had to be examined. The magnifying factors of the artifact in the spin echo sequence regarding titanium are between 1.7 and 3.2, depending on the direction of the magnetic vector. Regarding stainless steel they are between 8.4 and 8.5. In the gradient echo sequence the factors are between 7.5 and 7.7 for titanium and between 16.9 and 18.0 for stainless steel. The tip of an implant is imaged with an accuracy of 0 to 2 mm. Since September 1997 16 patients with unstable fractures of the thoracic and lumbar spine have been treated by dorsal instrumentation in the open MRI. Percutaneous insertion of the internal fixator has proven a successful minimally invasive procedure. The positioning of the screws in the pedicle is secure, the degree of indirect reduction of the posterior wall of the vertebral body can be imaged immediately. The diameter of the spinal canal can be determined in any plane. The open MRI has proven useful in orthopedic and trauma surgery. The size and configuration of the artifacts caused by instruments and implants is predictable. Therefore exact positioning of the implants is achieved more easily. Dorsal instrumentation of unstable thoracolumbar fractures with a percutaneous technique has turned out safe and less traumatic under MR-imaging. Real-time imaging of soft tissue and bone in any plane improves security for the patient and allows the surgeon to work less invasively and more precisely.

Detection of Cracking Levels in Brittle Rocks by Parametric Analysis of the Acoustic Emission Signals

NASA Astrophysics Data System (ADS)

Moradian, Zabihallah; Einstein, Herbert H.; Ballivy, Gerard

2016-03-01

Determination of the cracking levels during the crack propagation is one of the key challenges in the field of fracture mechanics of rocks. Acoustic emission (AE) is a technique that has been used to detect cracks as they occur across the specimen. Parametric analysis of AE signals and correlating these parameters (e.g., hits and energy) to stress-strain plots of rocks let us detect cracking levels properly. The number of AE hits is related to the number of cracks, and the AE energy is related to magnitude of the cracking event. For a full understanding of the fracture process in brittle rocks, prismatic specimens of granite containing pre-existing flaws have been tested in uniaxial compression tests, and their cracking process was monitored with both AE and high-speed video imaging. In this paper, the characteristics of the AE parameters and the evolution of cracking sequences are analyzed for every cracking level. Based on micro- and macro-crack damage, a classification of cracking levels is introduced. This classification contains eight stages (1) crack closure, (2) linear elastic deformation, (3) micro-crack initiation (white patch initiation), (4) micro-crack growth (stable crack growth), (5) micro-crack coalescence (macro-crack initiation), (6) macro-crack growth (unstable crack growth), (7) macro-crack coalescence and (8) failure.

Engineering Controlled Spalling in (100)-Oriented GaAs for Wafer Reuse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sweet, Cassi A.; McNeely, Joshua E.; Gorman, Brian

Controlled spalling offers a way to cleave thin, single-crystal films or devices from wafers, particularly if the fracture planes in the material are oriented parallel to the wafer surface. Unfortunately, misalignment between the favored fracture planes and the wafer surface preferred for photovoltaic growth in (100)-oriented GaAs produces a highly faceted surface when subject to controlled spalling. This highly faceted cleavage surface is problematic in several ways: (1) it can result in large variations of spall depth due to unstable crack propagation; (2) it may introduce defects into the device zone or underlying substrate; and (3) it consumes many micronsmore » of material outside of the device zone. We present the ways in which we have engineered controlled spalling for (100)-oriented GaAs to minimize these effects. We expand the operational window for controlled spalling to avoid spontaneous spalling, find no evidence of dislocation activity in the spalled film or the parent wafer, and reduce facet height and facet height irregularity. Resolving these issues provides a viable path forward for reducing III-V device cost through the controlled spalling of (100)-oriented GaAs devices and subsequent wafer reuse when these processes are combined with a high-throughput growth method such as Hydride Vapor Phase Epitaxy.« less

[Urogenital trauma associated with pelvic ring fractures].

PubMed

Pavelka, T; Houcek, P; Hora, M; Hlavácová, J; Linhart, M

2010-02-01

To evaluate, in a retrospective study, injuries to the urogenital tract in patients with pelvic ring fractures. MATERIAL In the years 1998-2007, a total of 308 patients with pelvic ring fractures were treated. The study did not comprise patients with low-energy fractures, such as apophyseolysis in children, osteoporotic bone fractures or pathologic fractures. It also did not include patients with multiple injuries who died within 6 hours of admission to the hospital. The group consisted of 186 men and 122 women with an average age of 34 (range, 6 to 76) years. The fractures sustained were classified as type A in 5 %, type B in 57 % and type C in 38 % of the patients. The average follow-up was 71 (range, 13 to 121) months. A primary injury to the urogenital tract was recorded in 50 (16 %) patients. Injury to the urethra was found in 23 (7.5%) and urinary bladder trauma in 18 (6%) patients, vaginal injury was in four women (1%), and penis injury in three (1%) and lacerated testicles in two men (1%). Injury to the urogenital tract was associated with a pelvic ring fracture type A in 5 %, type B in 34 % and type C in 61 % of the patients. Out of the 23 patients with urethral trauma, only six (26 %) were free from functional and subjective complaints; eight (35 %) continued to receive therapy for urethral stenosis seven (30 %) reported urinary incontinence, and seven men (30 %) had erection problems. In six patients (26%) the lasting sequelae were combined. The 18 patients with injury to the bladder reported no subjective complaints at a one-year follow-up. Two patients with penis root injury had erectile dysfunction. Two patients with the loss of both testicles were in the care of a psychiatrist. The patients' satisfaction was evaluated on a 0-to10-point scale. The average value for the whole group was 4.1 points. In the patients with erectile dysfunction, the value was 0.8, and in those with isolated injury to the urinary bladder it was 9.4 points. The increasing number of injuries to the urogenital tract associated with permanent sequelae is caused by a growing number of pelvic ring fractures as well as, and this is more important, by decreasing mortality in patients with severe trauma to the pelvic ring The extent of urogenital injury is related to the degree of dislocation of the pelvic skeleton. Injury to the male urethra is the most frequent urogenital trauma because of the male anatomy. It occurs most often in unstable C type fractures when the pelvic ring is disrupted with bone displacement due to shear force at the site of urethra attachment. The consequences are related to the quality of treatment of urogenital tract injury as well as to how the skeletal injury is managed. The lasting effects of the primary injury to nerve structures are beyond repair by therapy. Injury to the urethra results in erectile dysfunction in 50 % of the injured patients it is often associated with urinary incontinence that has a strong effect on the patient's life quality. Isolated trauma to the urinary bladder has a good prognosis. The incidence of post-traumatic incontinence is not high, but reduces the patient's personal and social comfort. A prerequisite for a successful therapeutic outcome is a good cooperation of the orthopaedic surgeon and urologist. Key words: pelvic ring fractures, urogenital injury.

Biomechanical stability of a supra-acetabular pedicle screw internal fixation device (INFIX) vs external fixation and plates for vertically unstable pelvic fractures.

PubMed

Vigdorchik, Jonathan M; Esquivel, Amanda O; Jin, Xin; Yang, King H; Onwudiwe, Ndidi A; Vaidya, Rahul

2012-09-27

We have recently developed a subcutaneous anterior pelvic fixation technique (INFIX). This internal fixator permits patients to sit, roll over in bed and lie on their sides without the cumbersome external appliances or their complications. The purpose of this study was to evaluate the biomechanical stability of this novel supraacetabular pedicle screw internal fixation construct (INFIX) and compare it to standard internal fixation and external fixation techniques in a single stance pelvic fracture model. Nine synthetic pelves with a simulated anterior posterior compression type III injury were placed into three groups (External Fixator, INFIX and Internal Fixation). Displacement, total axial stiffness, and the stiffness at the pubic symphysis and SI joint were calculated. Displacement and stiffness were compared by ANOVA with a Bonferroni adjustment for multiple comparisons The mean displacement at the pubic symphysis was 20, 9 and 0.8 mm for external fixation, INFIX and internal fixation, respectively. Plate fixation was significantly stiffer than the INFIX and external Fixator (P = 0.01) at the symphysis pubis. The INFIX device was significantly stiffer than external fixation (P = 0.017) at the symphysis pubis. There was no significant difference in SI joint displacement between any of the groups. Anterior plate fixation is stiffer than both the INFIX and external fixation in single stance pelvic fracture model. The INFIX was stiffer than external fixation for both overall axial stiffness, and stiffness at the pubic symphysis. Combined with the presumed benefit of minimizing the complications associated with external fixation, the INFIX may be a more preferable option for temporary anterior pelvic fixation in situations where external fixation may have otherwise been used.

Tangential Bicortical Locked Fixation Improves Stability in Vancouver B1 Periprosthetic Femur Fractures: A Biomechanical Study.

PubMed

Lewis, Gregory S; Caroom, Cyrus T; Wee, Hwabok; Jurgensmeier, Darin; Rothermel, Shane D; Bramer, Michelle A; Reid, John Spence

2015-10-01

The biomechanical difficulty in fixation of a Vancouver B1 periprosthetic fracture is purchase of the proximal femoral segment in the presence of the hip stem. Several newer technologies provide the ability to place bicortical locking screws tangential to the hip stem with much longer lengths of screw purchase compared with unicortical screws. This biomechanical study compares the stability of 2 of these newer constructs to previous methods. Thirty composite synthetic femurs were prepared with cemented hip stems. The distal femur segment was osteotomized, and plates were fixed proximally with either (1) cerclage cables, (2) locked unicortical screws, (3) a composite of locked screws and cables, or tangentially directed bicortical locking screws using either (4) a stainless steel locking compression plate system with a Locking Attachment Plate (Synthes) or (5) a titanium alloy Non-Contact Bridging system (Zimmer). Specimens were tested to failure in either axial or torsional quasistatic loading modes (n = 3) after 20 moderate load preconditioning cycles. Stiffness, maximum force, and failure mechanism were determined. Bicortical constructs resisted higher (by an average of at least 27%) maximum forces than the other 3 constructs in torsional loading (P < 0.05). Cables constructs exhibited lower maximum force than all other constructs, in both axial and torsional loading. The bicortical titanium construct was stiffer than the bicortical stainless steel construct in axial loading. Proximal fixation stability is likely improved with the use of bicortical locking screws as compared with traditional unicortical screws and cable techniques. In this study with a limited sample size, we found the addition of cerclage cables to unicortical screws may not offer much improvement in biomechanical stability of unstable B1 fractures.

Tangential Bicortical Locked Fixation Improves Stability in Vancouver B1 Periprosthetic Femur Fractures: A Biomechanical Study

PubMed Central

Lewis, Gregory S.; Caroom, Cyrus T.; Wee, Hwabok; Jurgensmeier, Darin; Rothermel, Shane D.; Bramer, Michelle A.; Reid, J. Spence

2015-01-01

Objectives The biomechanical difficulty in fixation of a Vancouver B1 periprosthetic fracture is purchase of the proximal femoral segment in the presence of the hip stem. Several newer technologies provide the ability to place bicortical locking screws tangential to the hip stem with much longer lengths of screw purchase compared to unicortical screws. This biomechanical study compares the stability of two of these newer constructs to previous methods. Methods Thirty composite synthetic femurs were prepared with cemented hip stems. The distal femur segment was osteotomized, and plates were fixed proximally with either: (1) cerclage cables; (2) locked unicortical screws; (3) a composite of locked screws and cables; or tangentially directed bicortical locking screws using either (4) a stainless steel LCP system with a Locking Attachment Plate (Synthes), or (5) a titanium alloy NCB system (Zimmer). Specimens were tested to failure in either axial or torsional quasi-static loading modes (n = 3) after 20 moderate load pre-conditioning cycles. Stiffness, maximum force, and failure mechanism were determined. Results Bicortical constructs resisted higher (by an average of at least 27%) maximum forces than the other three constructs in torsional loading (p<0.05). Cables constructs exhibited lower maximum force than all other constructs, in both axial and torsional loading. The bicortical titanium construct was stiffer than the bicortical stainless steel construct in axial loading. Conclusions Proximal fixation stability is likely improved with the use of bicortical locking screws as compared to traditional unicortical screws and cable techniques. In this study with a limited sample size, we found the addition of cerclage cables to unicortical screws may not offer much improvement in biomechanical stability of unstable B1 fractures. PMID:26053467

Treatment of distal-third clavicular fractures (Neer type ii-b) with a triple button device.

PubMed

Cano-Martínez, J A; Nicolás-Serrano, G; Andrés-Grau, J; Bento-Gerard, J

The purpose of this study is to describe the outcomes of using a triple button device for the treatment of displaced distal-third clavicle fractures (Neer, type ii-b). A retrospective review was conducted on a series of patients between November 2011 and December 2014. Fourteen patients initially met the inclusion criteria, but 2 were excluded, leaving 12 patients (83.3% male; mean age 32.2 years) for the final analysis at a mean follow-up of 26±11.24 months (range, 12-48). Post-operative follow-up was performed at 2 weeks (two first months), and monthly thereafter, until was achieving clinically and radiological healing. The functional outcome was evaluated using the Constant score, and DASH score in the last follow-up. The mean Constant Score was 95.5±5.2 points (range, 85-100), with a mean DASH score of 3.3±4.4 points (range, 0-12.5). The mean time to clinical healing was10.3±3.1 weeks (range, 8-16), and the mean time to radiological healing was 13.6±2.6 weeks (range, 12-20). There were no major complications. There were 5 minor complications without clinical impact: 2 coracoclavicular calcifications, 1 hypertrophic scar, 1 patient with discomfort due to the device, and 1 superficial wound infection. All patients returned their previous activity. Good clinical results can be achieved with the triple button device in unstable distal fractures of the clavicle, without the need to remove the hardware. Copyright © 2016 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Laboratory earthquakes triggered during eclogitization of lawsonite-bearing blueschist

NASA Astrophysics Data System (ADS)

Incel, Sarah; Hilairet, Nadège; Labrousse, Loïc; John, Timm; Deldicque, Damien; Ferrand, Thomas; Wang, Yanbin; Renner, Jörg; Morales, Luiz; Schubnel, Alexandre

2017-04-01

The origin of intermediate-depth seismicity has been debated for decades. A substantial fraction of these events occurs within the upper plane of Wadati-Benioff double seismic zones believed to represent subducting oceanic crust. We deformed natural lawsonite-rich blueschist samples under eclogite-facies conditions, using a D-DIA apparatus installed at a synchrotron beamline continuously monitoring stress, strain, phase changes, and acoustic emissions (AEs). Two distinct paths were investigated during which i) lawsonite and glaucophane became gradually unstable while entering the stability field of lawsonite-eclogite and the breakdown reaction of lawsonite was only crossed in case of the highest final temperature; ii) lawsonite broke down and the sample successively entered the stability fields of epidote-blueschist and eclogite-amphibolite but not of lawsonite-eclogite. Upon entering the Lws-Ecl stability field, samples exhibited brittle failure, accompanied by the radiation of AEs. In-situ X-ray diffraction and microstructural analysis demonstrate that fractures are topologically related to the formation of omphacite. Amorphous material was detected along the fractures by transmission-electron microscopy without evidence for free-water. Since the newly formed omphacite crystals are small compared to the initial grains, we interpret the observed mechanical instability as a transformation-induced runaway under stress triggered during the transformation from lawsonite-blueschist to lawsonite-eclogite. In contrast, we find no microstructural evidence that the breakdown of lawsonite, and hence the liberation of water leads to the fracturing. Our experimental results challenge the concept of "dehydration embrittlement", which ascribes the genesis of intermediate-depth earthquakes to the breakdown of hydrous phases in the subducting oceanic plate. Instead we suggest that grain-size reduction (transformational faulting) during the transformation from lawsonite-blueschist to lawsonite-eclogite leads to brittle failure of the deviatorically loaded samples.

Monitoring electrical properties for improving the lithological and hydrological characterization of landslides

NASA Astrophysics Data System (ADS)

Malet, J. P.; Gance, J.; Lajaunie, M.; Gallistl, J.; Denchik, N.; Flores Orozco, A.; Ottowitz, D.; Supper, R.; Sailhac, P.; Gautier, S.; Schmutz, M.

2017-12-01

Imaging water flows in landslides is of critical importance as the distribution of pore-fluid pressures controls the dynamics (acceleration, deceleration) of the material. Detecting and imaging water is a difficult task, not only because of the complex topography and the small dimensions of the geological structures, but also because the landslide material consists of unsaturated porous and heterogeneous fractured media, leading to multi-scale water-flow properties. Further, these properties can change in time, in relation to temperature, rainfall and biological forcings. Electrical properties are relevant proxies of the sub-surface hydrological properties. In order to image water in landslide bodies, we propose to combine multi-frequency electrical and electromagnetic measurements using campaigns or permanent instruments, and surface/boreole investigations, installed on several unstable slopes in France. To evaluate the information gained from electrical properties for different geological conditions, we discuss electrical and electro-magnetic imaging results for data collected at four different landslides located in France (Super-Sauze and La Valette in the South East Alps, Lodève lin the southern border of the Massif Central Massif, and Séchilienne in the North French Alps). Time-lapse electrical DC resistivity observations, complex electrical conductivity (conduction and polarization/chargeability) measured by IP imaging methods, and controlled-source electromagnetic (CS-AMT) methods are discussed. Imaging results demonstrate an improved lithological characterization of the landslide structures (delineation of the sliding planes, identification of the fractures, discrimination of clay lenses with enhanced resolution); further, water infiltration within the soil matrix and/or the fractures is discriminated allowing better modelling of the hydrological regime of the landslides at the slope scale. This research is conducted in the frame of the project HYDROSLIDE - Hydrogeophysical Monitoring of Clay-Rich Landslides funded by the Austrian Science Fund (FWF) and the French Research Agency (ANR).

More than mere numbers: the impact of lethal control on the social stability of a top-order predator.

PubMed

Wallach, Arian D; Ritchie, Euan G; Read, John; O'Neill, Adam J

2009-09-02

Population control of socially complex species may have profound ecological implications that remain largely invisible if only their abundance is considered. Here we discuss the effects of control on a socially complex top-order predator, the dingo (Canis lupus dingo). Since European occupation of Australia, dingoes have been controlled over much of the continent. Our aim was to investigate the effects of control on their abundance and social stability. We hypothesized that dingo abundance and social stability are not linearly related, and proposed a theoretical model in which dingo populations may fluctuate between three main states: (A) below carrying capacity and socially fractured, (B) above carrying capacity and socially fractured, or (C) at carrying capacity and socially stable. We predicted that lethal control would drive dingoes into the unstable states A or B, and that relaxation of control would allow recovery towards C. We tested our predictions by surveying relative abundance (track density) and indicators of social stability (scent-marking and howling) at seven sites in the arid zone subject to differing degrees of control. We also monitored changes in dingo abundance and social stability following relaxation and intensification of control. Sites where dingoes had been controlled within the previous two years were characterized by low scent-marking activity, but abundance was similar at sites with and without control. Signs of social stability steadily increased the longer an area was allowed to recover from control, but change in abundance did not follow a consistent path. Comparison of abundance and stability among all sites and years demonstrated that control severely fractures social groups, but that the effect of control on abundance was neither consistent nor predictable. Management decisions involving large social predators must therefore consider social stability to ensure their conservation and ecological functioning.

Internal fixation in pelvic fractures and primary repairs of associated genitourinary disruptions: a team approach.

PubMed

Routt, M L; Simonian, P T; Defalco, A J; Miller, J; Clarke, T

1996-05-01

Associated urological and orthopedic injuries of the pelvic ring are complex with numerous potential complications. These patients are treated optimally using a team approach. The combined expertise is not only helpful initially when managing these difficult patients, but also later as problems develop. This study describes a treatment protocol and reports the early results of 23 patients with unstable pelvic fractures and associated bladder or urethral disruptions, or both, treated surgically with open reduction and internal fixation of the anterior pelvic ring injuries at the same anesthetic and using the same surgical exposure as the urethral realignments or bladder repairs or both. Early complications occurred in four patients (17%): one patient sustained a fifth lumbar nerve injury caused by the pelvic reduction procedure, and three patients had anterior pelvic internal fixation failures. Late complications occurred in eight patients (35%). There was one deep wound infection (4.3%) that presented 6 weeks after injury. Late urological complications occurred in seven patients (30%). Four of the nine male patients with urethral disruptions had urethral stricture after their primary urethral realignments (44%). Three of the 18 male patients admitted to impotence (16.7%). One of the three had a residual thoracic paraplegia caused by a burst fracture. One of the five female patients had urinary incontinence and required a bladder suspension operation to restore normal function (20%). A low infection rate can be expected despite the use of internal fixation. Early urethral "indirect" realignments avoid more difficult delayed open repairs; however, late urological complication rates are still high. Early "direct" bladder repairs are easily performed at the time of anterior pelvic open reduction and internal fixation. Suprapubic tubes are not necessary to adequately divert the urine when large diameter urethral catheters are used in these patients.

Redefining Optimal Nail to Medullary Canal Diameter Ratio in Stainless Steel Flexible Intramedullary Nailing of Pediatric Femur Fractures.

PubMed

Shaha, James S; Cage, Jason M; Black, Sheena R; Wimberly, Robert L; Shaha, Steven H; Riccio, Anthony I

The ideal canal fill for flexible intramedullary fixation of pediatric femoral shaft fractures is considered to be 80% based upon relatively few clinical studies. The purpose of this study is to assess the relationship between the summed nail to intramedullary canal diameter (ND/MCD) ratio and alignment at radiographic union following flexible intramedullary nailing (FIMN) of pediatric femoral shaft fractures. An Internal Review Board approved, retrospective review of a consecutive series of patients who sustained a femoral shaft fracture treated by retrograde, stainless steel FIMN was performed at a single level 1 pediatric trauma center from 2005 to 2012. Preoperative radiographs were analyzed to determine fracture pattern, location, and isthmic canal diameter. ND/MCD ratio was calculated using the sum of the known nail diameters and the measured isthmic diameter. Radiographs at bony union were reviewed to measure shortening, coronal angulation, and sagittal angulation. ND/MCD ratio was analyzed to determine correlative factors with final radiographic outcomes. In total, 261 children underwent retrograde FIMN at an average age of 8.2 years (range, 2.2 to 17.0 y). ND/MCD ratio of ≥80% was seen in 108 (41.4%) patients. When compared with those with <80% ND/MCD ratio, there were no significant differences in age (8.8 vs. 8.0 y), sex (76.9% vs. 71.0% males), or body mass index (18.5 vs. 17.2 kg/m). There were significantly more length unstable fractures in the <80% ND/MCD ratio group (49.4% vs. 29.7%; P<0.01). Radiographic outcome was no different with respect to coronal angulation (2.7 vs. 3.0 degrees), sagittal angulation (3.0 vs. 3.2 degrees), or shortening (2.5 vs. 4.1 mm). ND/MCD ratio of ≥70% was seen in 176 (67.4%) patients and, when compared with the <70% ND/MCD ratio group, there were no differences in shortening (3.3 vs. 3.9 mm), coronal angulation (2.8 vs. 3.0 degrees), or sagittal angulation (3.0 vs. 3.4 degrees). Finally, 6.9% of the population (18 patients) had ND/MCD ratios <60% and did not demonstrate a significant increase in shortening, coronal, or sagittal angulation compared with groups with higher ND/MCD ratios. No group had an increased rate of infection, implant removal, nonunion, or need for reoperation. In a large series of consecutive patients treated with retrograde stainless steel FIMN there does not appear to be any correlation between the ND/MCD ratio and radiographic outcome. Stainless steel flexible IM nails seem to maintain fracture alignment without an increase in complications at lower ND/MCD ratios than previously reported as "optimal." Level III.

Knee fusion--a new technique using an old Belgian surgical approach and a new intramedullary nail.

PubMed

Alt, V; Seligson, D

2001-02-01

Knee arthrodesis is a useful procedure in difficult cases such as failed total knee arthroplasty, severe articular trauma, bone tumors, and infected knee joints. The most common techniques for knee fusion include external fixation and intramedullary nailing. Küntscher's nail is driven antegrade from the intertrochanteric region into the knee. We describe a new technique for knee arthrodesis using a new intramedullary nail and an old Belgian surgical approach to the knee joint published by Lambotte in 1913. This approach provides excellent exposure for the implantation of the nail by osteotomizing the patella vertically. The nail is implanted using HeyGroves method, whereby the nail is inserted retrograde into the femur and pulled distally anterograde into the tibia. We now use this technique as our standard procedure for knee fusion.

Morphological and structural changes at the Merapi lava dome monitored in 2012-15 using unmanned aerial vehicles (UAVs)

NASA Astrophysics Data System (ADS)

Darmawan, Herlan; Walter, Thomas R.; Brotopuspito, Kirbani Sri; Subandriyo; I Gusti Made Agung Nandaka

2018-01-01

Dome-building volcanoes undergo rapid and profound topographic changes that are important to quantify for the purposes of hazard assessment. However, as hazardous lava domes often develop on high-altitude volcanoes that exhibit steep-sided topography, it is challenging to obtain direct field access and thus to analyze these morphological and structural changes. Merapi Volcano in Indonesia is a type example of such a volcano, as soon after its 2010 eruption, a new lava dome developed. This dome was partially destroyed during six distinct steam-driven explosions that occurred between 2012 and 2014. Here, we investigate the topographic and structural changes associated with these six steam-driven explosions by comparing close-range photogrammetric data obtained before and after these explosions. To accomplish this, we performed two UAV campaigns in 2012 and 2015. By applying the Structure from Motion (SfM) technique, we are able to construct three-dimensional point clouds, assess their quality by comparing them to a terrestrial laser scanning (TLS) dataset, and generate high-resolution Digital Elevation Models (DEMs) and photomosaics. The comparison of these two DEMs and photomosaics reveals changes in topography and the appearance of fractures. In the 2012 dataset, we find a dense fracture network striking to the NNW-SSE. In the post-eruptive 2015 dataset, we see that this NNW-SSE fracture trend is much more strongly expressed; we also detect the formation of aligned and elongated explosion craters, which are associated with the removal of over 200,000 m3 of dome material, most of which ( 70%) was deposited outside the crater region. Therefore, this study suggests that the locations of the steam-driven explosions at Merapi Volcano were controlled by the reactivation of preexisting structures. Moreover, some of the newly developed and reactivated fractures delineate a block on the southern slope of the dome, which could become structurally unstable and potentially lead to rock avalanche hazards. This study therefore demonstrates the significance of characterizing structural fingerprints during the development of lava domes and exemplifies the value of topographic and fracture mapping, which is becoming increasingly feasible when using UAVs, even on high and steep stratovolcanoes. Fig. S2. The density of TLS point cloud dataset.

Biomechanical evaluation of a simulated T-9 burst fracture of the thoracic spine with an intact rib cage.

PubMed

Perry, Tiffany G; Mageswaran, Prasath; Colbrunn, Robb W; Bonner, Tara F; Francis, Todd; McLain, Robert F

2014-09-01

Classic biomechanical models have used thoracic spines disarticulated from the rib cage, but the biomechanical influence of the rib cage on fracture biomechanics has not been investigated. The well-accepted construct for stabilizing midthoracic fractures is posterior instrumentation 3 levels above and 2 levels below the injury. Short-segment fixation failure in thoracolumbar burst fractures has led to kyphosis and implant failure when anterior column support is lacking. Whether shorter constructs are viable in the midthoracic spine is a point of controversy. The objective of this study was the biomechanical evaluation of a burst fracture at T-9 with an intact rib cage using different fixation constructs for stabilizing the spine. A total of 8 human cadaveric spines (C7-L1) with intact rib cages were used in this study. The range of motion (ROM) between T-8 and T-10 was the outcome measure. A robotic spine testing system was programmed to apply pure moment loads (± 5 Nm) in lateral bending, flexion-extension, and axial rotation to whole thoracic specimens. Intersegmental rotations were measured using an optoelectronic system. Flexibility tests were conducted on intact specimens, then sequentially after surgically induced fracture at T-9, and after each of 4 fixation construct patterns. The 4 construct patterns were sequentially tested in a nondestructive protocol, as follows: 1) 3 above/2 below (3A/2B); 2) 1 above/1 below (1A/1B); 3) 1 above/1 below with vertebral body augmentation (1A/1B w/VA); and 4) vertebral body augmentation with no posterior instrumentation (VA). A repeated-measures ANOVA was used to compare the segmental motion between T-8 and T-10 vertebrae. Mean ROM increased by 86%, 151%, and 31% after fracture in lateral bending, flexion-extension, and axial rotation, respectively. In lateral bending, there was significant reduction compared with intact controls for all 3 instrumented constructs: 3A/2B (-92%, p = 0.0004), 1A/1B (-63%, p = 0.0132), and 1A/1B w/VA (-66%, p = 0.0150). In flexion-extension, only the 3A/2B pattern showed a significant reduction (-90%, p = 0.011). In axial rotation, motion was significantly reduced for the 3 instrumented constructs: 3A/2B (-66%, p = 0.0001), 1A/1B (-53%, p = 0.0001), and 1A/1B w/VA (-51%, p = 0.0002). Between the 4 construct patterns, the 3 instrumented constructs (3A/2B, 1A/1B, and 1A/1B w/VA) showed comparable stability in all 3 motion planes. This study showed no significant difference in the stability of the 3 instrumented constructs tested when the rib cage is intact. Fractures that might appear more grossly unstable when tested in the disarticulated spine may be bolstered by the ribs. This may affect the extent of segmental spinal instrumentation needed to restore stability in some spine injuries. While these initial findings suggest that shorter constructs may adequately stabilize the spine in this fracture model, further study is needed before these results can be extrapolated to clinical application.

Fracture mechanics modeling of popping event during daughter cell separation.

PubMed

Jiang, Yuxuan; Liang, Xudong; Guo, Ming; Cao, Yanping; Cai, Shengqiang

2018-05-10

Most bacteria cells divide by binary fission which is part of a bacteria cell cycle and requires tight regulations and precise coordination. Fast separation of Staphylococcus Aureus (S. Aureus) daughter cells, named as popping event, has been observed in recent experiments. The popping event was proposed to be driven by mechanical crack propagation in the peripheral ring which connected two daughter cells before their separation. It has also been shown that after the fast separation, a small portion of the peripheral ring was left as a hinge. In the article, we develop a fracture mechanics model for the crack growth in the peripheral ring during S. Aureus daughter cell separation. In particular, using finite element analysis, we calculate the energy release rate associated with the crack growth in the peripheral ring, when daughter cells are inflated by a uniform turgor pressure inside. Our results show that with a fixed inflation of daughter cells, the energy release rate depends on the crack length non-monotonically. The energy release rate reaches a maximum value for a crack of an intermediate length. The non-monotonic relationship between the energy release rate and crack length clearly indicates that the crack propagation in the peripheral ring can be unstable. The computed energy release rate as a function of crack length can also be used to explain the existence of a small portion of peripheral ring remained as hinge after the popping event.

Large deformation contact mechanics of a pressurized long rectangular membrane. II. Adhesive contact

PubMed Central

Srivastava, Abhishek; Hui, Chung-Yuen

2013-01-01

In part I of this work, we presented a theory for adhesionless contact of a pressurized neo-Hookean plane-strain membrane to a rigid substrate. Here, we extend our theory to include adhesion using a fracture mechanics approach. This theory is used to study contact hysteresis commonly observed in experiments. Detailed analysis is carried out to highlight the differences between frictionless and no-slip contact. Membrane detachment is found to be strongly dependent on adhesion: for low adhesion, the membrane ‘pinches-off’, whereas for large adhesions, it detaches unstably at finite contact (‘pull-off’). Expressions are derived for the critical adhesion needed for pinch-off to pull-off transition. Above a threshold adhesion, the membrane exhibits bistability, two stable states at zero applied pressure. The condition for bistability for both frictionless and no-slip boundary conditions is obtained explicitly. PMID:24353472

Linking megathrust earthquakes to brittle deformation in a fossil accretionary complex

PubMed Central

Dielforder, Armin; Vollstaedt, Hauke; Vennemann, Torsten; Berger, Alfons; Herwegh, Marco

2015-01-01

Seismological data from recent subduction earthquakes suggest that megathrust earthquakes induce transient stress changes in the upper plate that shift accretionary wedges into an unstable state. These stress changes have, however, never been linked to geological structures preserved in fossil accretionary complexes. The importance of coseismically induced wedge failure has therefore remained largely elusive. Here we show that brittle faulting and vein formation in the palaeo-accretionary complex of the European Alps record stress changes generated by subduction-related earthquakes. Early veins formed at shallow levels by bedding-parallel shear during coseismic compression of the outer wedge. In contrast, subsequent vein formation occurred by normal faulting and extensional fracturing at deeper levels in response to coseismic extension of the inner wedge. Our study demonstrates how mineral veins can be used to reveal the dynamics of outer and inner wedges, which respond in opposite ways to megathrust earthquakes by compressional and extensional faulting, respectively. PMID:26105966

Strain energy density and surface layer energy for a crack-like ellipse

NASA Technical Reports Server (NTRS)

Kipp, M. E.; Sih, G. C.

1973-01-01

Some of the fundamental concepts of sharp crack fracture criteria are applied to cracks and narrow ellipses. The strain energy density theory is extended to notch boundaries, where the energy in a surface layer is calculated and the location of failure initiation is determined. The concept of a core region near the notch tip, and its consequences, are examined in detail. The example treated is that of an elliptical cavity loaded uniformly at a large distance from the hole, and at an angle to the hole; the results are shown to approach that of the crack solution for narrow ellipses, and to display quite satisfactory agreement with recently published experimental data under both tensile and compressive loading conditions. Results also indicate that in globally unstable configurations in brittle materials, the original loading and notch geometry are sufficient to predict the subsequent crack trajectory with considerable accuracy.

Comparative analysis of locking plate versus hook plate osteosynthesis of Neer type IIB lateral clavicle fractures.

PubMed

Erdle, Benjamin; Izadpanah, Kaywan; Jaeger, Martin; Jensen, Patrizia; Konstantinidis, Lukas; Zwingmann, Jörn; Südkamp, Norbert P; Maier, Dirk

2017-05-01

Controversy exists on optimal operative treatment of vertically unstable Neer IIB lateral clavicle fractures. Aim of this study was to analyse and compare clinical and radiological results and complications of locking plate osteosynthesis (LPO) versus hook plate osteosynthesis (HPO) with acromioclavicular joint (ACJ) stabilization. The hypothesis was, that HPO would recreate coracoclavicular stability more effectively and potentially lead to a superior outcome. This retrospective, observational cohort study included 32 patients (19 HPO, 13 LPO) with a mean age of 44.1 ± 14.2 years at surgery. The mean follow-up period was 54.2 months (range 25.2-111.4 months). Besides standard radiography, bilateral coracoclavicular distances were assessed by means of preoperative and follow-up stress radiographs after implant removal. Clinical outcome measures included the Constant score (CS), the Oxford shoulder score (OSS), the subjective shoulder value (SSV) and the Taft score (TS). Bone union occurred in all but one patient and proved to occur delayed in five patients (15.6%). Radiographical healing required a mean of 4.2 ± 4.0 months irrespective of the type of osteosynthesis. At follow-up, mean coracoclavicular distance was increased by 34% (±36) without significant differences between both groups. HPO patients obtained a significantly lower TS (HPO: 9.5 ± 1.5 points, LPO: 11.1 ± 1.3 points; p = 0.005). Other mean score values did not differ (CS: 90.1 ± 7.4 points, OSS: 43.2 ± 9.2 points, SSV: 91.1 ± 14.7%). Sixteen patients (50.0%) experienced complications. Overall prevalence of complications was significantly higher in the HPO group (p = 0.014). Both HPO and LPO were equally effective in relation to restoration of vertical stability, overall functional outcome and fracture consolidation in treatment of Neer IIB fractures. Contrary to our hypothesis, HPO was not associated with superior recreation of the coracoclavicular distance. Considerable drawbacks of HPO were an inferior ACJ-specific outcome (Taft-Score) and a higher overall complication rate. Level of evidence IV.

Determining level of care appropriateness in the patient journey from acute care to rehabilitation

PubMed Central

2011-01-01

Background The selection of patients for rehabilitation, and the timing of transfer from acute care, are important clinical decisions that impact on care quality and patient flow. This paper reports utilization review data on inpatients in acute care with stroke, hip fracture or elective joint replacement, and other inpatients referred for rehabilitation. It examines reasons why acute level of care criteria are not met and explores differences in decision making between acute care and rehabilitation teams around patient appropriateness and readiness for transfer. Methods Cohort study of patients in a large acute referral hospital in Australia followed with the InterQual utilization review tool, modified to also include reasons why utilization criteria are not met. Additional data on team decision making about appropriateness for rehabilitation, and readiness for transfer, were collected on a subset of patients. Results There were 696 episodes of care (7189 bed days). Days meeting acute level of care criteria were 56% (stroke, hip fracture and joint replacement patients) and 33% (other patients, from the time of referral). Most inappropriate days in acute care were due to delays in processes/scheduling (45%) or being more appropriate for rehabilitation or lower level of care (30%). On the subset of patients, the acute care team and the utilization review tool deemed patients ready for rehabilitation transfer earlier than the rehabilitation team (means of 1.4, 1.3 and 4.0 days from the date of referral, respectively). From when deemed medically stable for transfer by the acute care team, 28% of patients became unstable. From when deemed stable by the rehabilitation team or utilization review, 9% and 11%, respectively, became unstable. Conclusions A high proportion of patient days did not meet acute level of care criteria, due predominantly to inefficiencies in care processes, or to patients being more appropriate for an alternative level of care, including rehabilitation. The rehabilitation team was the most accurate in determining ongoing medical stability, but at the cost of a longer acute stay. To avoid inpatients remaining in acute care in a state of 'terra nullius', clinical models which provide rehabilitation within acute care, and more efficient movement to a rehabilitation setting, is required. Utilization review could have a decision support role in the determination of medical stability. PMID:22040281

Percutaneous Distraction Pinning for Metacarpophalangeal Joint Stabilization After Blast or Crush Injuries of the Hand.

PubMed

Langford, Matthew A; Cheung, Kevin; Li, Zhongyu

2015-09-01

Unstable, severely comminuted fractures of the metacarpophalangeal (MCP) joint are difficult to treat. Closed treatment and casting of these fractures often fail to maintain proper alignment and impede wound care where concomitant open injuries such as gunshot wounds are present. Conventional pinning or plating techniques are not feasible if extensive bone loss and comminution are present. A distraction pinning technique represents a potential alternative, but results with this approach, to our knowledge, have not been reported. The purposes of this study were (1) to evaluate the effectiveness (defined as osseous union and joint stability) of distraction pinning for comminuted fractures involving MCP joints after gunshot or crush injuries; (2) to report the short-term results in terms of pain and function in a small group of patients who underwent MCP distraction pinning; and (3) to evaluate complications and return to work status of these patients in the short term. We reviewed 10 patients with comminuted pilon-type fractures of the base of the proximal phalanx or metacarpal head treated with wire distraction fixation from 2005 and 2014. During that period, we used this technique to treat all patients whose fractures were deemed too comminuted for plating or pinning, and during that period, no other techniques (such as simple external fixation) were used for patients meeting those indications. The minimum followup was 6 months; eight of the 10 patients were accounted at a median of 10 months (range, 6-89 months). The median age was 47 years (range, 28-57 years), and seven of the eight were male. Kirschner wire fixation frames were removed 3.5 to 6 weeks after the index surgery when fracture consolidation was confirmed on radiography by the treating surgeon. Stability and range of motion of the MCP joint were assessed using physical examination, radiographs, and goniometer by the treating surgeon. Patients completed the Quick Disabilities of the Arm, Shoulder and Hand score at latest followup or by telephone, and complications were assessed by chart review. All fractures were healed with stable MCP joints. Eight patients reported having no pain or minimal pain of their injuries to the hand. The median finger and thumb MCP arc of motion were 80° (range, 70°-105°) and 30° (range, 0°-60°), respectively. The median Quick Disabilities of the Arm, Shoulder and Hand score was 3 (range, 0-41). One patient underwent a second surgical procedure for bone grafting and soft tissue coverage. Three patients developed pin site irritations and were treated with oral antibiotics. Six patients returned to their original job. The distraction pinning technique provides reliable osseous union and joint stability of comminuted pilon-type fractures of the base of the proximal phalanx or metacarpal head, even with associated open wounds. Future studies will need to evaluate these patients at longer term followup and compare this approach with other available techniques, because arthrosis, stiffness, and progressive loss of function seem likely to occur given the severity of these injuries. Level IV, therapeutic study.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balhoff, Matthew; Tavassoli, Shayan; Fei Ho, Jostine

The potential leakage of hydrocarbon fluids or CO 2 out of subsurface formations through wells with fractured cement or debonded microannuli is a primary concern in oil and gas production and CO 2 storage. The presence of fractures in a cement annulus with apertures on the order of 10–300 microns can pose a significant leakage danger with effective permeability in the range of 0.1–1 mD (millidarcy). Leakage pathways with small apertures are often difficult to repair using conventional oilfield cement, thus a low-viscosity sealant that can be easily placed into these fractures while providing an effective seal is desired. Themore » development of a novel application using pH-triggered polymeric sealants could potentially be the solution to plugging these fractures and that was the research aim of this study. The application is based on the transport and reaction of a low-pH poly(acrylic acid) polymer through fractures in strongly alkaline cement. The pH-sensitive microgels viscosify upon neutralization with cement to become highly swollen gels with substantial yield stress that can block fluid flow. Experiments in a cement fracture determined the effects of the viscosification and gel deposition via real-time visual observation and measurements of pressure gradient and effluent pH. While the pH-triggered gelling mechanism and rheology measurements of the neutralized polymer gel show promising results, the polymer solution in contact with cement undergoes an undesirable reaction known as polymer syneresis. Syneresis is caused by the release of calcium cation from cement that collapses the polymer network. Syneresis produces an unstable calcium-precipitation byproduct that is detrimental to the strength and stability of the gel in place. As a result, gel-sealed leakage pathways that subjected to various degrees of syneresis often failed to hold back pressures. Several chemicals were studied to inhibit polymer syneresis and tested for pretreatment of cement cores to remove calcium and prevent syneresis during polymer placement. A chelating agent, sodium triphosphate (Na 5P 3O 10), was found to successfully eliminate syneresis without compromising the injectivity of polymer solution during placement. Polymer gel strength is determined by recording the maximum holdback pressure gradients during liquid breakthrough tests after various periods of pretreatment and polymer shut-in time. Cores pretreated with Na 5P 3O 10 successfully held up to an average of 80 psi/ft, which is significantly greater than the expected threshold value of about 0.1-5 psi/ft required to prevent flow in a typical CO 2 leakage scenario. The use of such inexpensive, pH-triggered poly-acrylic acid polymer allows long-term robust seal of leaky wellbores under high pH conditions.« less