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Sample records for compression plate fixation

  1. 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.

  2. Biomechanical comparison of straight and helical compression plates for fixation of transverse and oblique bone fractures: Modeling and experiments.

    PubMed

    Sezek, Sinan; Aksakal, Bunyamin; Gürger, Murat; Malkoc, Melih; Say, Y

    2016-08-12

    Total deformation and stability of straight and helical compression plates were studied by means of the finite element method (FEM) and in vitro biomechanical experiments. Fixations of transverse (TF) and oblique (45°) bone (OF) fractures have been analyzed on sheep tibias by designing the straight compression (SP) and Helical Compression Plate (HP) models. The effects of axial compression, bending and torsion loads on both plating systems were analyzed in terms of total displacements. Numerical models and experimental models suggested that under compression loadings, bone fracture gap closures for both fracture types were found to be in the favor of helical plate designs. The helical plate (HP) fixations provided maximum torsional resistance compared to the (SP) fixations. The fracture gap closure and stability of helical plate fixation for transverse fractures was determined to be higher than that found for the oblique fractures. The comparison of average compression stress, bending and torsion moments showed that the FEM and experimental results are in good agreement and such designs are likely to have a positive impact in future bone fracture fixation designs.

  3. Surgical Outcomes of Biologic Fixation for Subtrochanteric Fracture Using Locking Compression Plates

    PubMed Central

    Jang, Jae Hoon; Ahn, Jae Min; Lee, Hee Jin

    2017-01-01

    Purpose This study aimed to evaluate the surgical outcomes of biologic plating using locking compression plate-distal femur (LCP-DF) in patients with subtrochanteric fracture of the femur. Materials and Methods Between January 2010 and December 2013, 28 consecutive patients with subtrochanteric fractures of the femur, treated with biologic fixation using LCP-DF, were enrolled. Preoperative values, including patient age, sex, body mass index, fracture type, type of lung injury, and surgical timing from injury to surgery, were retrospectively evaluated. Radiologic assessments included time to union, coronal alignment, rotational alignment, and complications such as implant breakage and screw breakage. Adverse events, including postoperative fat embolism and adult respiratory distress syndrome, infection during the follow-up period, and walking ability at the last follow-up visit, were assessed. Results Union was achieved in 27 patients (96.4%) after a mean duration of 5.4 months (range, 3-14 months). No patients developed fat embolism or adult respiratory distress syndrome during the hospitalization period of this study. Conclusion Biologic fixation using locking compression plates may represent a safe surgical option which can be utilized in patients with subtrochanteric fracture regardless of injury severity, surgical timing, fracture type, and presence of lung injury. PMID:28316965

  4. A biomechanical comparison of conventional versus an anatomic plate and compression bolts for fixation of intra-articular calcaneal fractures.

    PubMed

    Wang, Haili; Yang, Zhaoxu; Wu, Zhanpo; Chen, Wei; Zhang, Qi; Li, Ming; Li, Zhiyong; Zhang, Yingze

    2012-08-01

    The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures. Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-III calcaneal fracture model by using osteotomy. The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws. Reduction of fracture was evaluated through X radiographs. Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N, representing the partial weight bearing and full weight bearing, respectively, and then the specimens were loaded to failure. Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test. No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading (P=0.06), while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading (P=0.008). The load achieved at loss of fixation of the constructs for the two groups had significant difference: anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N (P=0.008). There was no significant difference between the ultimate displacements. Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading. The study supports the mechanical viability of using our plate and

  5. Fixation of Intertrochanteric Fractures: Dynamic Hip Screw versus Locking Compression Plate

    PubMed Central

    Mardani-Kivi, Mohsen; Mirbolook, Ahmadreza; Khajeh Jahromi, Sina; Rouhi Rad, Melina

    2013-01-01

    Background According to the existing literature, the Dynamic Hip Screw (DHS) is the preferred standard for the treatment of intertrochanteric fractures. However, some surgeons use other devices such as the Locking Compression Plate (LCP). Objectives In this study, we compared the outcome of using DHS or LCP in intertrochanteric fractures. Materials and Methods This cross-sectional study was carried out on 104 patients who were referred to Pursina Hospital in Rasht, Iran with intertrochanteric fractures of the femur treated with either the DHS or LCP devices. Demographic features, existence or nonexistence of stability and operating time were obtained from questionnaires. During a 6-month follow-up after surgery, patients were interviewed to record variables such as Harris Hip Scores and complications. The patients were also interviewed on their final visit (between 9 and 31 postoperative months). The collected data was analyzed using SPSS. Results We discovered that the number of incidences of limb shortening and device failure was higher for patients treated with the LCP device (P = 0.048 and P = 0.014). Patients treated with the DHS device had higher Harris Hip scores for both the 6-month postoperative and the final evaluation visits (P = 0.01 and P = 0.018). Conclusions Despite the complications of fixation with the DHS device, it remains the most successful for treatment of intertrochanteric fractures. PMID:24350155

  6. Treatment of Unstable Posterior Pelvic Ring Fracture with Pedicle Screw-Rod Fixator Versus Locking Compression Plate: A Comparative Study

    PubMed Central

    Bi, Chun; Wang, Qiugen; Nagelli, Christopher; Wu, Jianhong; Wang, Qian; Wang, Jiandong

    2016-01-01

    Background The aim of this study was to assess the clinical results of treatment for unstable posterior pelvic fractures using a pedicle screw-rod fixator compared to use of a locking compression plate. Material/Methods A retrospective study was performed between June 2010 and May 2014 and the data were collected from 46 patients with unstable posterior pelvic ring fractures. All patients were treated using either a pedicle screw-rod fixator (study group, 24 patients) or locking compression plate (control group, 22 patients). In these patients, causes of injury included traffic accidents (n=27), fall from height (n=12), and crushing accidents (n=7). The quality of reduction and radiological grading were assessed. Clinical assessments included the operation time, times of X-ray exposures, bleeding volume during operation, incision length, and Majeed postoperative functional evaluation. Results No iatrogenic neurovascular injuries occurred during the operations in these 2 groups. The average follow-up time was 24.5 months. All fractures were healed. The significant differences (P<0.05) between the 2 groups were operation duration, size of incision, and intraoperative bleeding volume. Statistically significant differences in the Majeed postoperative functional evaluation and times of X-ray exposures were not found between the 2 groups. Conclusions Similar clinical effects were achieved in treating the posterior pelvic ring fractures using the pedicle screw-rod fixator and the locking compression plate. However, the pedicle screw-rod fixator has the advantages of smaller incision, shorter duration of the operation, and less bleeding volume compared to using the locking compression plate. PMID:27748355

  7. Comparison of tension band wiring and precontoured locking compression plate fixation in Mayo type IIA olecranon fractures.

    PubMed

    Schliemann, Benedikt; Raschke, Michael J; Groene, Philipp; Weimann, André; Wähnert, Dirk; Lenschow, Simon; Kösters, Clemens

    2014-03-01

    Aim of the present study was to compare the clinical and radiographic outcome of tension band wiring and precontoured locking compression plate fixation in patients treated surgically for an isolated olecranon fractures type IIA according to the Mayo classification. Of 26 patients presenting with an isolated Mayo type IIA olecranon fracture, 13 underwent fixation with a precontoured locking compression plate (group A), 13 patients were treated with tension band wiring (group B). At a mean follow-up of 43 months, patients were clinically and radiographically re-examined using the DASH score, the Mayo Elbow Performance score (MEPS) and anteroposterior and lateral radiographs. The mean DASH score was 14 points in group A and 12.5 points in group B. Regarding the MEPS, 92% of the patients in group A achieved a good to excellent results in comparison to 77% in group B. No significant differences between the two groups could be detected regarding the clinical and radiographic outcome. Implant-related irritations requiring hardware removal occurred more frequently in group B (12 vs. 7). Procedure and implant related costs were significantly higher in group A. Tension band wiring is still a preferable surgical method to treat simple isolated olecranon fractures. The patient must be informed that in all likelihood implant removal will be required once the fracture has healed. Fixation with precontoured locking compression plates does not provide better functional and radiographic outcome but is more expensive than tension band wiring.

  8. Use of a locking compression plate as an external fixator for repair of a tarsometatarsal fracture in a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Montgomery, Ronald D; Crandall, Elizabeth; Bellah, Jamie R

    2011-06-01

    We describe the successful treatment of a tarsometatarsal fracture in a mature bald eagle (Haliaeetus leucocephalus) using a locking compression plate as an external fixator. The anatomy of the area (inelastic dermis and minimal subcutaneous space) and the high forces placed on a fracture at that site necessitated a unique approach to fixation. The unconventional use of a locking compression plate as an external fixator was minimally invasive, well tolerated by the eagle, and provided adequate stability in opposing fracture forces. This technique may serve as a method of fixation for tarsometatarsal fractures in other large avian species.

  9. Reoperation rate after internal fixation of intertrochanteric femur fractures with the percutaneous compression plate: what are the risk factors?

    PubMed

    Schmidt-Rohlfing, Bernhard; Heussen, Nicole; Knobe, Matthias; Pfeifer, Roman; Kaneshige, Jason R; Pape, Hans-Christoph

    2013-06-01

    The aim was this study was to analyze the risk factors for reoperation after internal fixation of intertrochanteric fractures of the femur using the percutaneous compression plate (PCCP). This was a retrospective cohort study. The study was conducted at the University Hospital. Patients with intertrochanteric femur fractures who underwent internal fixation with a PCCP were included in this study. We investigated potential risk factors such as age, gender, body mass index, comorbidities of the patients (American Society of Anesthetist classification), type of fracture (AO/OTA classification), experience of the surgeons (in terms of the number of surgical procedures with the PCCP device), tip-apex distance (TAD), and operation time. The procedures were performed by 10 surgeons. Logistic regression was used to assess potential predictors for the need of reoperation. Of the 96 patients with 96 intertrochanteric fractures, 8 underwent reoperation due to local complications (8.3%). The most frequent complication was complete or imminent cutting out of the upper cervical screw (N = 5; 5.2%). Five of the 8 risk factors that were associated with reoperation in the initial univariable analyses with a P value of <0.20 were retained in a multivariable logistic regression model, including, age, body mass index, TAD, experience of the surgeons, and operation time. Of these, only the factor TAD proved to be a significant predictor for reoperation (P = 0.027, odds ratio = 1.089, 95% confidence interval 1.01-1.175). Our data show that the surgeon-related risk factors (number of operations, operation time, TAD) seem to be more relevant for the reoperation rate after internal fixation with the PCCP device when compared with the patient-related risk factors. This finding indicates a substantial learning curve for this technically demanding procedure. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

  10. Minimally invasive plate osteosynthesis with a locking compression plate is superior to open reduction and internal fixation in the management of the proximal humerus fractures.

    PubMed

    Lin, Tao; Xiao, Baojun; Ma, Xiucai; Fu, Dehao; Yang, Shuhua

    2014-06-16

    The use of minimally invasive plate osteosynthesis (MIPO) via anterolateral deltoid splitting has good outcomes in the management of proximal humerus fractures. While using this approach has several advantages, including minimal soft tissue disruption, preservation of natural biology and minimal blood loss, there is an increased risk for axillary nerve damage. This study compared the advantages and clinical and radiological outcomes of MIPO or open reduction and internal fixation (ORIF) in patients with proximal humerus fractures. A matched-pair analysis was performed, and patient groups were matched according to age (±3 years), sex and fracture type. Forty-three pairs of patients (average age: MIPO, 63 and ORIF, 61) with a minimum follow-up of 12 months were enrolled in the study group. The patients were investigated radiographically and clinically using the Constant score. The MIPO technique required less surgery time and caused less blood loss compared to ORIF (p < 0.01). In addition, MIPO required a smaller incision, resulted in less scarring, and was cosmetically more appealing and acceptable to female patients than ORIF. Following MIPO, patients had better functional results at 3 and 6 months, with better outcomes, less pain, higher satisfaction in activities of daily living, and a higher range of motion when compared to ORIF (p < 0.05). Fracture configuration, according to the AO/ASIF(Association for the Study of Internal Fixation) fracture classification, did not significantly influence the functional results. The complication rate was comparable between both groups. The use of MIPO with a locking compression plate in the management of proximal humerus fractures is a safe and superior option compared to ORIF.

  11. Minimally invasive plate osteosynthesis with a locking compression plate is superior to open reduction and internal fixation in the management of the proximal humerus fractures

    PubMed Central

    2014-01-01

    Background The use of minimally invasive plate osteosynthesis (MIPO) via anterolateral deltoid splitting has good outcomes in the management of proximal humerus fractures. While using this approach has several advantages, including minimal soft tissue disruption, preservation of natural biology and minimal blood loss, there is an increased risk for axillary nerve damage. This study compared the advantages and clinical and radiological outcomes of MIPO or open reduction and internal fixation (ORIF) in patients with proximal humerus fractures. Methods A matched-pair analysis was performed, and patient groups were matched according to age (±3 years), sex and fracture type. Forty-three pairs of patients (average age: MIPO, 63 and ORIF, 61) with a minimum follow-up of 12 months were enrolled in the study group. The patients were investigated radiographically and clinically using the Constant score. Results The MIPO technique required less surgery time and caused less blood loss compared to ORIF (p < 0.01). In addition, MIPO required a smaller incision, resulted in less scarring, and was cosmetically more appealing and acceptable to female patients than ORIF. Following MIPO, patients had better functional results at 3 and 6 months, with better outcomes, less pain, higher satisfaction in activities of daily living, and a higher range of motion when compared to ORIF (p < 0.05). Fracture configuration, according to the AO/ASIF(Association for the Study of Internal Fixation) fracture classification, did not significantly influence the functional results. The complication rate was comparable between both groups. Conclusion The use of MIPO with a locking compression plate in the management of proximal humerus fractures is a safe and superior option compared to ORIF. PMID:24934152

  12. Mechanical Comparison of Headless Screw Fixation and Locking Plate Fixation for Talar Neck Fractures.

    PubMed

    Karakasli, Ahmet; Hapa, Onur; Erduran, Mehmet; Dincer, Cemal; Cecen, Berivan; Havitcioglu, Hasan

    2015-01-01

    For talar neck fractures, open reduction and internal fixation have been thought to facilitate revascularization and prevent osteonecrosis. Newer screw systems allow for placement of cannulated headless screws, which provide compression by virtue of a variable pitch thread. The present study compared the biomechanical fixation strength of cannulated headless variable-pitch screw fixation and locking plate fixation. A reproducible talar neck fracture was created in 14 fresh cadaver talar necks. Talar head fixation was then performed using 2 cannulated headless variable-pitch 4-mm/5-mm diameter (4/5) screws (Acutrak; Acumed, Hillsboro, OR) and locking plate fixation. Headless variable-pitch screw fixation had lower failure displacement than did locking plate fixation. No statistically significant differences were found in failure stiffness, yield stiffness (p = .655), yield load (p = .142), or ultimate load between the 2 fixation techniques. Cannulated headless variable-pitch screw fixation resulted in better failure displacement than locking plate fixation in a cadaveric talus model and could be considered a viable option for talus fracture fixation. Headless, fully threaded, variable-pitch screw fixation has inherent advantages compared with locking plate fixation, because it might cause less damage to the articular surface and can compress the fracture for improved reduction. Additionally, plate fixation can increase the risk of avascular necrosis owing to the wider incision and dissection of soft tissues.

  13. Simulation-based particle swarm optimization and mechanical validation of screw position and number for the fixation stability of a femoral locking compression plate.

    PubMed

    Lee, Chian-Her; Shih, Kao-Shang; Hsu, Ching-Chi; Cho, Tomas

    2014-01-01

    Locking compression plates (LCPs) have been used to fix femoral shaft fractures. Previous studies have attempted to identify the best LCP screw positions and numbers to achieve the fixation stability. However, the determined screw positions and numbers were mainly based on the surgeons' experiences. The aim of this study was to discover the best number and positions of LCP screws to achieve acceptable fixation stability. Three-dimensional numerical models of a fractured femur with the LCP were first developed. Then, the best screw position and number of LCPs were determined by using a simulation-based particle swarm optimization algorithm. Finally, the results of the numerical study were validated by conducting biomechanical tests. The results showed that the LCP with six locking screws resulted in the necessary fixation stability, and the best combination of positions of locking screws inserted into the LCP was 1-5-6-7-8-12 (three locking screws on either side of the bone fragment with two locking screws as close as practicable to the fracture site). In addition, the numerical models and algorithms developed in this study were validated by the biomechanical tests. Both the numerical and experimental results can provide clinical suggestions to surgeons and help them to understand the biomechanics of LCP systems.

  14. Comparison of double dynamic compression plating versus two configurations of an internal veterinary fixation device: Results of in vitro mechanical testing using a bone substitute.

    PubMed

    Haerdi-Landerer, Christina; Steiner, Adrian; Linke, Berend; Wahl, Dieter; Schneider, Erich; Hehli, Markus; Frei, Reto; Auer, Jörg A

    2002-01-01

    To compare the mechanical properties of 2 configurations of a veterinary fixation system (VFS) for large animal long bones with dynamic compression plating (DCP). Eighteen pairs of Canevasit tubes (Canevasit; Amsler und Frei, Schinznach Dorf, Switzerland) (length, 170 mm; diameter, 47.5 mm; cortex thickness, 10 mm), aligned with a 10-mm gap, and stabilized with 2 DCP or 2 VFS implants. Three groups (n = 6) were compared. Group 1 Canevasit tubes were stabilized with two 10-hole, broad 4.5-mm stainless steel DCP applied with both plates centered over the gap, in orthogonal planes parallel to the long axis of the tubes and staggered to allow bicortical fixation with ten 4.5-mm, 52-mm-long cortex screws each. Group 2 tubes were stabilized similarly with 2 VFS implants, each composed of a stainless steel rod (length, 167 mm; diameter, 8 mm), and 10 clamps were applied in alternating fashion left and right on the rod and fixed bicortically with ten 4.5-mm, 52-mm-long, cortex screws. Group 3 tubes were stabilized similarly, but using only 6 clamps/rod. All groups were tested initially in torsion within elastic limits and subsequently in 4-point bending, with 1 implant on the tension side, until gap closure occurred. None of the constructs failed, but all had plastic deformation after 4-point bending. No statistically significant differences were found among the 3 groups in torsional stiffness. Double DCP fixation was significantly stiffer and stronger in 4-point bending, compared with both configurations of double VFS fixation. The plate design was favored in this study. The VFS system may have to be adapted before further tests are conducted. Test modalities have to be chosen closer to clinical conditions (real bone, cyclic loading, closed gap). The veterinary fixation system has not yet proven its advantages for large animal long bone fracture repair. From the pure mechanical point of view, double DCP is the favored method for the treatment mentioned. Copyright 2002 by

  15. Comparison of Outcomes of Intertrochanteric Fracture Fixation Using Percutaneous Compression Plate Between Stable and Unstable Fractures in the Elderly.

    PubMed

    Carvajal-Pedrosa, Cristina; Gómez-Sánchez, Rafael C; Hernández-Cortés, Pedro

    2016-06-01

    To evaluate the outcomes of treatment with a percutaneous compression plate (PCCP) in stable and unstable intertrochanteric hip fractures. Clinical prospective nonrandomized cohort study. San Cecilio University Hospital, Granada (Spain). A tertiary-care hospital. Patients older than 65 years undergoing surgery for an intertrochanteric hip fracture (n = 657) were divided according to the OTA/AO classification, into stable (31-A1) (group A, n = 363) and unstable fractures (31-A2) (group B, n = 294). Osteosynthesis with a PCCP (Orthofix Inc). Blood loss, wound complications, postoperative pain, operative and fluoroscopy time, functional outcomes, device-related complications, consolidation time, and mortality. Patients with unstable fractures were significantly worse with respect to postoperative pain, immediately (P = 0.020), at 6 weeks (P = 0.0001), and at 3 months (P = 0.009), and with respect to independent walking ability at 6 weeks. No other significant differences were observed. The outcomes of osteosynthesis with PCCP seem to be equally satisfactory in stable and unstable intertrochanteric fractures, with stable fractures having less pain and a greater ability to walk earlier. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

  16. Intramedullary nail versus dynamic compression plate fixation in treating humeral shaft fractures: grading the evidence through a meta-analysis.

    PubMed

    Ma, JianXiong; Xing, Dan; Ma, XinLong; Gao, Feng; Wei, Qiang; Jia, HaoBo; Feng, Rui; Yu, JingTao; Wang, Jie

    2013-01-01

    There is a debate regarding the choice of operative intervention in humeral shaft fractures that require surgical intervention. The choices for operative interventions include intramedullary nailing (IMN) and dynamic compression plate (DCP). This meta-analysis was performed to compare fracture union, functional outcomes, and complication rates in patients treated with IMN or DCP for humeral shaft fractures and to develop GRADE (Grading of Recommendations, Assessment, Development, and Evaluation)-based recommendations for using the procedures to treat humeral shaft fractures. A systematic search of all the studies published through December 2012 was conducted using the Medline, Embase, Sciencedirect, OVID and Cochrane Central databases. The randomized controlled trials (RCTs) and quasi-RCTs that compared IMN with DCP in treating adult patients with humeral shaft fractures and provided data regarding the safety and clinical effects were identified. The demographic characteristics, adverse events and clinical outcomes were manually extracted from all of the selected studies. Ten studies that included a total of 448 patients met the inclusion criteria. The results of a meta-analysis indicated that both IMN and DCP can achieve similar fracture union with a similar incidence of radial nerve injury and infection. IMN was associated with an increased risk of shoulder impingement, more restriction of shoulder movement, an increased risk of intraoperative fracture comminution, a higher incidence of implant failure, and an increased risk of re-operation. The overall GRADE system evidence quality was very low, which reduces our confidence in the recommendations of this system. DCP may be superior to IMN in the treatment of humeral shaft fractures. Because of the low quality evidence currently available, high-quality RCTs are required.

  17. Biomechanical comparison of odontoid plate fixation versus odontoid screw fixation.

    PubMed

    Platzer, Patrick; Eipeldauer, Stefan; Leitgeb, Johannes; Aldrian, Silke; Vécsei, Vilmos

    2011-05-01

    Randomized controlled trial with statistically significant difference or statistically no significant difference (Level I). The purpose of this study was to measure the mechanical stability of odontoid plate fixation, using a specially designed plate construct and to compare the results with those after odontoid single-screw and double-screw fixation. Plate fixation of the odontoid process without C1-C2 is a possible option for the management of odontoid fractures that are not suitable for conventional screw fixation. Although earlier biomechanical works have evaluated the effectiveness of different odontoid screw fixation techniques, no study has quantified the mechanical stability of odontoid fixation by a plate device. The second cervical vertebra was removed from 15 fresh human spinal columns. The specimens were fixed to the experimental apparatus with the load cell at the articular surface of the odontoid process. In the first test series, stiffness and failure load of the intact odontoid were measured. Type II odontoid fractures were created by a 45 degree oblique extension loading at the articular surface of the odontoid process. Afterward, the specimens were randomly assigned to 1 of the following 3 groups: in group I (n=5), the fractures were stabilized, using a specially designed plate construct, in group II, the fractures were fixed, using two 3.5 mm cortical screws, and in group III, we used 1 regular 4.5 mm cortical screw. In the second test series, stiffness and failure load of the stabilized odontoid fractures were assessed for comparison and statistical analysis. Group I (plate device) showed a significantly higher mean failure load than group II and group III. The mean failure load of group I, after fixation of the odontoid fracture, was 84% of the mean failure load that was necessary to create a type II odontoid fracture initially. Comparing group II (double screw technique) and group III (single screw technique), there was no significant

  18. Biomechanical comparison of straight DCP and helical plates for fixation of transverse and oblique bone fractures.

    PubMed

    Aksakal, Bunyamin; Gurger, Murat; Say, Yakup; Yilmaz, Erhan

    2014-01-01

    Biomechanical comparison of straight DCP and helical plates for fixation of transversal and oblique tibial bone fractures were analyzed and compared to each other by axial compression, bending and torsion tests. An in vitro osteosynthesis of transverse (TF) and oblique bone fracture (OF) fixations have been analysed on fresh sheep tibias by using the DCP and helical compression plates (HP). Statistically significant differences were found for both DCP and helical plate fixations under axial compression, bending and torsional loads. The strength of fixation systems was in favor of DC plating with exception of the TF-HP fixation group under compression loads and torsional moments. The transvers fracture (TF) stability was found to be higher than that found in oblique fracture (OF) fixed by helical plates (HP). However, under torsional testing, compared to conventional plating, the helical plate fixations provided a higher torsional resistance and strength. The maximum stiffness at axial compression loading and maximum torsional strength was achieved in torsional testing for the TF-HP fixations. From in vitro biomechanical analysis, fracture type and plate fixation system groups showed different responses under different loadings. Consequently, current biomechanical analyses may encourage the usage of helical HP fixations in near future during clinical practice for transverse bone fractures.

  19. [Long-term results of calcaneal fracture treatment by open reduction and internal fixation using a calcaneal locking compression plate from an extended lateral approach].

    PubMed

    Zeman, P; Zeman, J; Matejka, J; Koudela, K

    2008-12-01

    To report on the surgical treatment of intra-articular calcaneal fractures by open reduction and internal fixation with a calcaneal locking compression plate (LCP) from an extended lateral approach, and to retrospectively analyze the mid-term results in a group of patients treated by this technique. In the period from August 2005 till March 2007, a total of 49 patients with 61 calcaneal fractures were treated. Of these, 11 (18 %) were treated conservatively. Reduction combined with Kirschner-wire fixation was used in four fractures (6.6 %). Open reduction with internal calcaneal LCP fixation (ORIF- calcaneal LCP) from an extended lateral approach was carried out to treat 46 fractures (75.4 %) in 38 patients. The group evaluated here comprised 29 patients with 33 calcaneal fractures treated by ORIF-calcaneal LCP at a follow-up longer than 6 months. The fractures were classified on the basis of computer tomography (CT) findings as Sanders types I to IV. The group had two woman (6.9 %) and 27 men (93.1 %) with an average age of 34.2 years (range, 19-55 years). In 11 fractures (33.3 %), the primary treatment included filling a central cancellous bone defect area. Calcium phosphate bone substitute material (resorbable ChronOS) was used in nine cases (27.3 %), a self-solidifying hydroxyapatite implant was injected in two (6.1 %) cases (X3 Wright and Norian SRS, respectively), and a bone allograft was implanted in one case (3 %). Indicated for surgery were patients with an intra-articular calcaneal fracture, Sanders type II or type III, with articular surface displacement by more than 1 mm. Contraindications included age over sixty years, poor cooperation, smoking habits, peripheral vascular disease or skin infection. Surgery was performed only after oedema had resolved. The aim of our treatment was to achieve anatomical reconstruction of all articular surfaces, to restore the height, length, width and axis of the heel bone, to carry out primary stable osteosynthesis, and

  20. A biomechanical study of conventional acetabular internal fracture fixation versus locking plate fixation

    PubMed Central

    Mehin, Ramin; Jones, Bryn; Zhu, Qingan; Broekhuyse, Henry

    2009-01-01

    Background Conventional internal fixation entails the use of an interfragmentary lag screw along with a plate. Not all acetabular fractures are amenable to the placement of an interfragmentary lag screw, and the fracture may be displaced during tightening of the interfragmentary lag screw. Locking plates are a possible solution. We sought to determine whether a locking plate construct can provide stability equivalent to that provided with a conventional construct for transverse acetabular fractures. Methods We used 5 paired fresh-frozen cadaveric acetabula. We fixed one side with the conventional technique and the other side with a locking plate. We subjected each fixation to a cyclic compressive force up to 500 cycles, followed by compressive force until failure. We monitored 3-dimensional motion of the fracture. Results The average fracture gap at 50 N compressive force after 500 loading cycles was 0.41 (standard deviation [SD] 0.49) mm for the conventional plate and lag screw construct compared with 0.76 (SD 0.62) mm for the locked plate construct (p = 0.46). The force to failure, as defined by 2 mm of fracture gap, was 848 (SD 805) N for the conventional plate and lag screw construct compared with 506 (SD 277) N for the locked plate fixation (p = 0.34). Conclusion The locking plate construct is as strong as the conventional plate plus interfragmentary lag screw construct for fixing transverse acetabular fractures. Locking plates may improve management of acetabular fractures by eliminating the need for placement of an interfragmentary lag screw. Furthermore, they may be helpful in revision hip arthroplasty in patients with pelvic discontinuity. PMID:19503667

  1. Clinical and radiographic outcome of unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation for cervical compressive myelopathy: a five-year follow-up study.

    PubMed

    Wang, Lin-Nan; Wang, Lei; Song, Yue-Ming; Yang, Xi; Liu, Li-Min; Li, Tao

    2016-06-01

    To evaluate the five year clinical and radiographic outcome of unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation for cervical compressive myelopathy. From August 2009 to June 2010, 56 patients with cervical compressive myelopathy underwent unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation with a mean age of 64.8 years. Clinical results were investigated including Japanese Orthopedic Association (JOA) scores, Neck Dysfunction Index (NDI), occurrences of complications and neurological deterioration. Radiographic results including cervical alignments, cervical range of motion (ROM), spinal canal enlargement and spinal cord decompression were assessed on X-ray, three-dimensional CT and MRI. The mean follow-up period was 59.2 months (range 53∼64 months), and all patients achieved osseous fusion at hinge side at an average of 6.8 months after operation. The average cost from admission to discharge is $9817.9. Compared to previous all-level fixation, the cost decreased nearly 40 %. During the follow-up, all patients showed a significant improvement in the JOA score and NDI score. A 23.2 % incidence of axial neck pain were also observed; Significant enlargement of the spinal canal and spinal cord drift was achieved and well maintained, overall cervical ROM decreased by 27.1 % (mean 12.9° loss) at the final follow-up and cervical lordosis decreased slightly in all patients without statistic difference. No instrumentation failure or lamina reclosure was observed in our study. Comparing mini-plate segments and suture segments, the mean AP diameter and Pavlov's ratio at the final follow-up showed no statistic difference, only open angle at the final follow-up showed significant decrease. Unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation is a safe, effective and economical surgical method for cervical compressive myelopathy and the five year result

  2. In vitro biomechanical comparison of limited contat dynamic compression plate and locking compression plate.

    PubMed

    Aguila, A Z; Manos, J M; Orlansky, A S; Todhunter, R J; Trotter, E J; Van der Meulen, M C H

    2005-01-01

    The locking compression plate (LCP) supports biological osteosynthesis by functioning as an internal fixator, rather than as a full or limited contact bone plate which must be adequately contoured and affixed directly to the bone for stable internal fixation of the fracture. In order to help justify the use of the LCP in our veterinary patients, in vitro biomechanical testing was performed comparing the LCP to the conventional limited contact dynamic compression plate (LC-DCP) in canine femurs. We hypothesized that the LCP construct would be at least as stiff under bending and torsional loads as the LC-DCP. The LCP and LC-DCP were applied over a 20-mm osteotomy gap to contralateroal bones within each pair of 14 femora. Non-destructive four-point bending and torsion, and cyclical testing in torsion were performed. The constructs were then loaded to failure in torsion. In medial-lateral and lateral-medial structural bending, significant differences were not found between the LCP and LC-DCP, however, at the gap, the LCP construct was stiffer than the LC-DCP in lateral-medial bending. Significant differences in behaviour over time were not noted between the plate designs during cyclical testing. When loading the constructs to failure in internal rotation, the LC-DCP failed at a significantly lower twist angle (P = .0024) than the LCP. Based on the similar performance with loading, the locking compression plate is a good alternative implant for unstable diaphyseal femoral fracture repair in dogs.

  3. Outcome comparison of Lisfranc injuries treated through dorsal plate fixation versus screw fixation

    PubMed Central

    Hu, Sun-jun; Chang, Shi-min; Li, Xiao-hua; Yu, Guang-rong

    2014-01-01

    OBJECTIVE: The objective of this prospective study was to test whether the treatment of Lisfranc injuries with open reduction and dorsal plate fixation would have the same or better functional outcomes as treatment with standard trans-articular screw fixation. METHODS: Sixty patients with primarily isolated Lisfranc joint injury were treated by open reduction and dorsal plate fixation or standard screw fixation. The patients were followed on average for 31 months. Evaluation was performed with patients' chief complaint, clinical examination, radiography, and AOFAS Midfoot Scale. RESULTS: Thirty two patients were treated with open reduction and dorsal plate fixation, and twenty eight patients were treated with open reduction and screw fixation. After two years follow-up, the mean AOFAS Midfoot score was 83.1 points in the dorsal plate fixation group and 78.5 points in the screw fixation group (p<0.01). Of the dorsal plate fixation group, radiographic analysis revealed anatomic reduction in twenty-nine patients (90.6%, 29/32) and nonanatomic reduction in three patients. Of the screw fixation group, radiographic analysis revealed anatomic reduction in twenty-three patients and nonanatomic reduction in five patients (82.1%, 23/28). CONCLUSIONS: Open reduction and dorsal plate fixation for a dislocated Lisfranc injury do have better short and median term outcome and a lower reoperation rate than standard screw ORIF. In our experience, we recommend using dorsal plate in ORIF on dislocated Lisfranc injuries. Level of Evidence II, Prospective Comparative Study. PMID:25538478

  4. Removal of symptomatic titanium fixation plates after craniotomy.

    PubMed

    Gupta, Raghav; Adeeb, Nimer; Griessenauer, Christoph J; Moore, Justin M; Patel, Apar S; Thomas, Ajith J; Ogilvy, Christopher S

    2016-10-01

    Titanium fixation plates are routinely used for rigid fixation of bone flaps after craniotomy. In craniofacial surgery or after craniotomy involving orbitozygomatic osteotomies, these plates are occasionally removed because of infection, pain, protrusion, soft tissue erosion, and plate malfunction. However, plate removal because of pain and protrusion after craniotomy without orbitozygomatic osteotomy has rarely been reported. A retrospective analysis of all patients who underwent removal of cranial fixation plates after craniotomy, performed by the senior authors at one institution between 2014 and 2016, was conducted. A total of 319 patients underwent bone flap fixation after craniotomy using cranial fixation plates between 2014 and 2016. Five of those patients (1.6 %) had their cranial plates removed because of pain and protrusion. An additional four patients had a cranial fixation plate removed during that time frame with the original craniotomy performed before 2014. All nine patients had immediate resolution of symptoms after plate removal. We report our experience with cranial fixation plate removal because of pain and protrusion in patients who underwent craniotomy without orbitozygomatic osteotomy, particularly frontotemporal craniotomy. In an attempt to reduce this complication, we recently stopped placing a full-size burr hole in the keyhole area of a frontotemporal craniotomy, eliminating the need for a titanium burr hole cover plate.

  5. Mini-plate fixation versus suture suspensory fixation in cervical laminoplasty

    PubMed Central

    Liu, Feng-Yu; Ma, Lei; Huo, Li-Shuang; Cao, Yan-Xiang; Yang, Da-Long; Wang, Hui; Yang, Si-Dong; Ding, Wen-Yuan

    2017-01-01

    Abstract Background: Both the mini-plate fixation and suture suspensory fixation techniques are extensively applied in cervical laminoplasty, but which technique is superior has not been ascertained. The purpose of this meta-analysis is to compare the results between mini-plate fixation and suture suspensory fixation in cervical laminoplasty for the patients with multilevel cervical compressive myelopathy. Methods: PubMed, Embase, the Cochrane library, CNKI, and WANFANG were searched for studies that compared mini-plate fixation and suture suspensory fixation in cervical laminoplasty up to November 1, 2016. We calculated odds ratio (OR) with 95% confidence interval (CI) for dichotomous outcomes and mean difference (MD) with 95% CI for continuous outcomes. Review Manager 5.3 was used for the statistical analyses. Results: A total of 25 studies, involving 1603 participants, were included in this review. The results of this meta-analysis indicated that there were statistically significant differences in postoperative Japanese Orthopedic Association (JOA) scores (MD = 0.67, 95% CI: 0.34–0.99, P < 0.001), JOA scores improvement rate (MD = 4.00, 95% CI: 2.51–5.50, P < 0.001), postoperative Visual Analogue Score (VAS) (MD = −0.81, 95% CI: −1.36 to −0.26, P = 0.004), postoperative range of motion (ROM) (MD = 4.15, 95% CI: 2.06–6.23, P < 0.001), postoperative cervical lordosis (MD = 3.1, 95% CI: 2.02–4.18, P < 0.001), postoperative anteroposterior diameter of the spinal canal (MD = 1.53, 95% CI: 0.11–2.95, P = 0.03), postoperative open angle (MD = 1.93, 95% CI: 0.14–3.71, P = 0.03), postoperative cross-sectional area of the spinal canal (MD = 37.10, 95% CI: 26.92–47.29, P < 0.001), axial symptoms (OR = 0.28, 95% CI: 0.20–0.37, P < 0.001), operation time (MD = 4.46, 95% CI: 0.74–8.19, P = 0.02), and blood loss (MD = 9.24, 95% CI: 6.86–11.62, P < 0.001). However

  6. New concepts for bone fracture treatment and the Locking Compression Plate.

    PubMed

    Wagner, Michael; Frenk, Andre; Frigg, Röbi

    2004-01-01

    The operative treatment of bone fractures using plates and screws is a standard successful technique. Internal fixation with plates and screws leads to additional trauma and disturbance of the bone blood supply, which increases the risk of delayed union and infection. However, problems also are encountered in the fixation of osteoporotic bone. The locked internal fixator technique is an approach to optimize internal fixation. It aims at flexible elastic fixation to imitate spontaneous healing, including induction of callus formation. The technology supports what is currently called "minimally invasive plate osteosynthesis" (MIPO), which provides priority to biology over mechanics. An implant system called "Locking Compression Plate (LCP)" was developed, based on many years of experience with compression plating and good clinical results obtained with internal fixators, such as the Less Invasive Stabilization Systems (LISS). It combines the two treatment methods (ie, the compression plating and locked internal fixation methods) into one system. This chapter describes the basic principles of locked internal fixators and some clinical results with the LISS and LCP systems to illustrate the potential of these new systems.

  7. Unicortical versus bicortical locked plate fixation in midshaft clavicle fractures.

    PubMed

    Bravman, Jonathan T; Taylor, Michal L; Baldini, Todd; Vidal, Armando F

    2015-05-01

    Higher rates of poor outcomes in displaced midshaft clavicle fractures treated nonoperatively have recently been reported. Along with expanding indications for operative fixation and increasing application of locked plate constructs, it is unknown whether complications related to bicortical penetration of the clavicle can be avoided using unicortical fixation. The purpose of this study is to compare the biomechanical properties of unicortical and bicortical fixation in precontoured vs manually contoured locking clavicle plates. Forty-eight Sawbone composite human clavicle specimens (item #3408; Pacific Research Laboratories, Vashon, Washington) with a midshaft clavicle osteotomy were reduced and plated in 8 specimens each using a bicortical and unicortical fixation for each of 3 locked plate constructs (3.5-mm LCP Reconstruction Plate; 3.5-mm LCP Superior Clavicle Plate; 3.5-mm LCP Superior Anterior Clavicle Plate; Synthes, Inc, West Chester, Pennsylvania). Specimens were tested for stiffness in axial torsion and cantilever bending and then loaded to failure in 3-point bending. Data were analyzed using 2-way analysis of variance and Tukey's test (P<.05). No significant differences were found between unicortical and bicortical fixation in failure load, cantilever bending, and cross body stiffness. Bicortical fixation was significantly stiffer than unicortical fixation in torsion only for the same plates. Significant differences also existed between plates in torsion. Unicortical locked plate fixation may be a reasonable option in the treatment of displaced midshaft clavicle fracture fixation to avoid complications associated with posteroinferior hardware penetration following clavicle fracture fixation based on the biomechanical performance of these constructs. However, it remains unclear whether these differences will be clinically significant.

  8. Operative Cost Comparison: Plating Versus Intramedullary Fixation for Clavicle Fractures.

    PubMed

    Hanselman, Andrew E; Murphy, Timothy R; Bal, George K; McDonough, E Barry

    2016-09-01

    Although clavicle fractures often heal well with nonoperative management, current literature has shown improved outcomes with operative intervention for specific fracture patterns in specific patient types. The 2 most common methods of midshaft clavicle fracture fixation are intramedullary and plate devices. Through retrospective analysis, this study performed a direct cost comparison of these 2 types of fixation at a single institution over a 5-year period. Outcome measures included operative costs for initial surgery and any hardware removal surgeries. This study reviewed 154 patients (157 fractures), and of these, 99 had intramedullary fixation and 58 had plate fixation. A total of 80% (79 of 99) of intramedullary devices and 3% (2 of 58) of plates were removed. Average cost for initial intramedullary placement was $2955 (US dollars) less than that for initial plate placement (P<.001); average cost for removal was $1874 less than that for plate removal surgery (P=.2). Average total cost for all intramedullary surgeries was $1392 less than the average cost for all plating surgeries (P<.001). Average cost for all intramedullary surgeries requiring plate placement and removal was $653 less than the average cost for all plating surgeries that involved only placement (P=.04). Intramedullary fixation of clavicle fractures resulted in a statistically significant cost reduction compared with plate fixation, despite the incidence of more frequent removal surgeries. [Orthopedics.2016; 39(5):e877-e882.].

  9. Fixation properties of a biodegradable "free-form" osteosynthesis plate.

    PubMed

    Väänänen, Petteri; Nurmi, Janne T; Nuutinen, Juha-Pekka; Jakonen, Sanna; Happonen, Harri; Jank, Siegfried

    2008-10-01

    The Inion FreedomPlate, a "free-form" osteosynthesis plate, is a biodegradable plate with just pilot holes for drilling. The construction of the plate allows the surgeon a placement of screws in optimal position. The screw heads can either be countersunk into the plate or cut off. Furthermore, the plate can be cut and contoured to match the bone. The aim of this study was to determine the mechanical properties of the Inion FreedomPlate compared to a conventional biodegradable plate. Acrylic pipes were fixed together with plates and screws. Tensile and cantilever bending tests were performed to measure the fixation properties. In the tensile test, the samples were loaded with a constant speed of 5 mm/min until failure of fixation. The yield load, maximum failure load, and initial stiffness were recorded, and the failure mode was visually determined. In the cantilever bending test, the samples were loaded with a constant speed of 50 mm/min (with a moment arm of 45 mm) until failure of fixation. The yield bending moment and initial stiffness were recorded, and the failure mode was determined. The results of the study show that the new free-form plate provides at least as strong fixation as the tested conventional biodegradable plate. No clinically relevant difference was found between free-form plates fixed with into-the-plate countersunk screws and those fixed with screws without heads.

  10. Biomechanics and biology of plate fixation of distal radius fractures.

    PubMed

    Freeland, Alan E; Luber, Kurre T

    2005-08-01

    The fracture management principles of anatomic or near anatomic reduction, fracture stabilization, minimal operative trauma, and early joint motion are paramount in man-aging unstable distal radial fractures. The operative approach and plate selection should correlate with the fracture configuration. Plates have the advantages of providing secure fixation throughout the entire healing process without protruding wires or pins and allowing early and intensive forearm, wrist, and digital exercises. Disadvantages include additional operative trauma, including fragment devascularization; some additional risk of wrist stiffness; occasional tendon rupture; and at times, the need for plate removal. New developments in plate and screw design and operative strategies, fragment specific fixation, and plate strength have improved results with plate fixation. Fixed angle blades and locking screws and pegs enhance overall plate stability, support the articular surface of the distal radius, and are effective in fractures occurring in osteopenic bone.

  11. An in vitro biomechanical comparison of hydroxyapatite coated and uncoated ao cortical bone screws for a limited contact: dynamic compression plate fixation of osteotomized equine 3rd metacarpal bones.

    PubMed

    Durham, Myra E; Sod, Gary A; Riggs, Laura M; Mitchell, Colin F

    2015-02-01

    To compare the monotonic biomechanical properties of a broad 4.5 mm limited contact-dynamic compression plate (LC-DCP) fixation secured with hydroxyapatite (HA) coated cortical bone screws (HA-LC-DCP) versus uncoated cortical bone screws (AO-LC-DCP) to repair osteotomized equine 3rd metacarpal (MC3) bones. Experimental. Adult equine cadaveric MC3 bones (n = 12 pair). Twelve pairs of equine MC3 were divided into 3 test groups (4 pairs each) for: (1) 4 point bending single cycle to failure testing; (2) 4 point bending cyclic fatigue testing; and (3) torsional single cycle to failure testing. For the HA-LC-DCP-MC3 construct, an 8-hole broad LC-DCP (Synthes Ltd, Paoli, PA) was secured on the dorsal surface of each randomly selected MC3 bone with a combination of four 5.5 mm and four 4.5 mm HA-coated cortical screws. For the AO-LC-DCP-MC3 construct, an 8-hole 4.5 mm broad LC-DCP was secured on the dorsal surface of the contralateral MC3 bone with a combination of four 5.5 mm and four 4.5 mm uncoated cortical screws. All MC3 bones had mid-diaphyseal osteotomies. Mean test variable values for each method were compared using a paired t-test within each group. Significance was set at P < .05. Mean yield load, yield bending moment, composite rigidity, failure load, and failure bending moment, under 4 point bending, single cycle to failure, of the HA-LC-DCP fixation were significantly greater than those of the AO-LC-DCP fixation. Mean ± SD values for the HA-LC-DCP and the AO-LC-DCP fixation techniques, respectively, in single cycle to failure under 4 point bending were: yield load, 26.7 ± 2.15 and 16.3 ± 1.38 kN; yield bending moment, 527.4 ± 42.4 and 322.9 ± 27.2 N-m; composite rigidity, 5306 ± 399 and 3003 ± 300 N-m/rad; failure load, 40.6 ± 3.94 and 26.5 ± 2.52 kN; and failure bending moment, 801.9 ± 77.9 and 522.9 ± 52.2 N-m. Mean cycles to failure in 4 point bending of the HA

  12. Comparison of the effect on bone healing process of different implants used in minimally invasive plate osteosynthesis: limited contact dynamic compression plate versus locking compression plate

    PubMed Central

    Xue, Zichao; Xu, Haitao; Ding, Haoliang; Qin, Hui; An, Zhiquan

    2016-01-01

    Minimally invasive plate osteosynthesis (MIPO) has been widely accepted because of its satisfactory clinical outcomes. However, the implant construct that works best for MIPO remains controversial. Different plate designs result in different influence mechanisms to blood flow. In this study, we created ulnar fractures in 42 beagle dogs and fixed the fractures using MIPO. The dogs were randomly divided into two groups and were fixed with a limited contact dynamic compression plate (LC-DCP) or a locking compression plate (LCP). Our study showed that with MIPO, there was no significant difference between the LCP and the LC-DCP in terms of fracture fixation, bone formation, or mineralization. Combined with the previous literature, we inferred that the healing process is affected by the quality of fracture reduction more than plate selection. PMID:27885262

  13. Locking versus standard plates for allograft fixation after tumor resection in children and adolescents.

    PubMed

    Buecker, Peter J; Berenstein, Mariela; Gebhardt, Mark C; Hornicek, Francis J; Mankin, Henry J

    2006-01-01

    This investigation was undertaken to assess the performance of locking plates in comparison to standard compression plates for allograft fixation after resection of malignant primary skeletal tumors. Using a computerized database, patients younger than 18 years who had undergone resection of malignant skeletal tumors with allograft reconstruction from January 1998 through June 2004 were identified. Demographic, oncological, surgical, and follow-up data were collected, and comparison of outcomes with regard to allograft-host junction healing between locking and standard compression plates was undertaken. Thirty-nine patients meeting the inclusion criteria were identified. Homogeneity of the study group with regards to age, sex, diagnosis, adjuvant therapy, and presence of metastases allowed for evaluation of allograft-host union as a relatively independent variable. Nine patients in the locking plate group (75%) united after the index procedure at an average of 13.1 months. Fifteen patients (55.6%) with compression plates healed after the initial reconstruction at an average of 14.6 months. Complications and secondary procedures were noted. Results of this investigation suggest that use of locking plates for allograft-host junction fixation is associated with improved union rates and less need for additional operations when compared with standard compression plates.

  14. Auxetic polymeric bone plate as internal fixator for long bone fractures: Design, fabrication and structural analysis.

    PubMed

    Mehmood, Seemab; Ali, Murtaza Najabat; Ansari, Umar; Mir, Mariam; Khan, Munezza Ata

    2015-01-01

    Injuries cover about 11% of World's Disease Burden depicting fractures to be the leading severe consequence of trauma. Fractures occur due to force impact or osteoporosis. Fracture healing is a complicated process. Fracture fixation techniques focus on imparting reduction to fractured fragments and induce healing. When considering possible fixation methods, the aspect of micro-movement is an important one, as this induces callus formation which tends to be a crucial step for fracture healing. Internal fixation of long bone fractures using metallic plates has been carried out since decades and recently advancements have been in synthesizing biodegradable plates as well. The purpose of this research was to fabricate an Auxetic Polymeric Bone Plate that can be used as an internal fixator for long bone fracture; this bone plate renders micro-movement due to its counter intuitive behavior, has the potential to reduce the effect of stress shielding and allow the same range of motion as that of natural bone. Polyurethane was chosen as a material for the fabrication of the Auxetic device because of its biocompatibility and non-toxic effects. The plate was then tested for mechanical properties such as Tensile and Compression testing to determine the strength. The tensile testing of the Auxetic polyurethane specimens showed that the mean of the Poisson's ratio of the samples lies between -0.68 and -0.87 at different uni-axial tensile load values. The Auxetic structure of our device has the potential to allow for efficient fixation because its negative Poisson's ratio offers micro-movement, thereby causing fixation with relative stability rather than absolute stability. The Auxetic bone plate can be superior to contemporary plate fixation systems, as it demands meaningfully small contact points. The suitable mechanical properties might lessen stress shielding effects that are normally caused by rigid bone plates. The Auxetic nature of the bone will help align and sustain the

  15. Biomechanical Study of the Fixation Plates For Opening Wedge High Tibial Osteotomy

    PubMed Central

    Kim, Kug Jin; Song, Eun Kyoo; Seon, Jong Keun

    2015-01-01

    Purpose The purpose of this study was to compare the mechanical stability of three types of plate systems for opening wedge high tibial osteotomy. Materials and Methods Forty-eight fresh frozen porcine tibia specimens were assigned to three different fixation device groups: Aescular group (16 specimens) was fixed with Aescular plates; Puddu group (16 specimens) with a Puddu plate, and TomoFix group (16 specimens) with a TomoFix plate. We compared axial displacements under compression loads from 200 to 2,000 N and maximal loads at failure among 8 specimens per group. We also compared displacements under cyclic load after 100 cycles at a compressive load of 2,000 N among 8 specimens per group. Results In all three groups, displacement under compression load increased with the increase in the axial compressive load; however, no significant intergroup differences were observed in the mean values under tested loading conditions. The mean maximal loads at failure were not significantly different (6,055, 6,798, and 6,973 N in the Aescular, Puddu, and TomoFix groups, respectively; p=0.41). While the TomoFix group showed less extension and strain during the cyclic load test, the mean values showed no significant differences among groups. Conclusions All three plate systems were found to provide fixation stability suitable for bearing axial compression and cyclic loads while walking. PMID:26389072

  16. Failure analysis of stainless steel femur fixation plate.

    PubMed

    Hussain, P B; Mohammad, M

    2004-05-01

    Failure analysis was performed to investigate the failure of the femur fixation plate which was previously fixed on the femur of a girl. Radiography, metallography, fractography and mechanical testing were conducted in this study. The results show that the failure was due to the formation of notches on the femur plate. These notches act as stress raisers from where the cracks start to propagate. Finally fracture occurred on the femur plate and subsequently, the plate failed.

  17. A biomechanical comparison of short segment long bone fracture fixation techniques: single large fragment plate versus 2 small fragment plates.

    PubMed

    Watts, Adriel; Weinhold, Paul; Kesler, William; Dahners, Laurence

    2012-09-01

    To determine whether using 2 small fragment plates (3.5 mm screw size) side by side is biomechanically superior to the use of 1 large fragment plate (4.5 mm screw size), in the fixation of "short segments" in long bone fractures. Fiber-filled epoxy bone surrogates were plated across 1-cm gaps with 3 different constructs. Six surrogates were fixed using 2 side-by-side 3.5-mm waisted compression plates and six 3.5-mm screws, 6 surrogates were fixed using one 4.5-mm waisted compression plate and two 4.5-mm screws, and 6 surrogates were fixed using one 3.5-mm waisted compression plate and three 3.5-mm screws. These constructs then underwent cyclic axial compression in 100-N increments until 500 N was reached. Then, they underwent cyclic cantilever bending at 2 Hz and at a 23.6 N·m moment until fatigue failure occurred. Also, a single load to failure test was performed in cantilever bending to evaluate plate strength. The cumulative gap length change after 500 cycles of loading up to 500 N was 3.4% ± 0.4% for the 3.5 mm double plate construct, 9.5% ± 1.4% for the 4.5 mm single plate construct, and 14.4% ± 0.9% for the 3.5 mm single plate construct. In cantilever bending, the 3.5 mm double plate construct failed after 15,345 ± 2493 cycles, the 4.5 mm single plate construct failed after 2713 ± 1811 cycles, and the 3.5 mm single plate construct failed in its first cycle. In single load to failure testing, the load at offset yield was higher in the 3.5 mm double plate construct than the 4.5 mm single plate construct. This study suggests that in situations where anatomy or other limitations limit the length of bone segments available for fixation, it may be preferable to use 2 small plates with more screws rather than 1 large plate with few screws.

  18. Assessment of carbon fibre composite fracture fixation plate using finite element analysis.

    PubMed

    Saidpour, Seyed H

    2006-07-01

    In the internal fixation of fractured bone by means of bone-plates fastened to the bone on its tensile surface, an on-going concern has been the excessive stress shielding of the bone by the excessively-stiff stainless-steel plate. The compressive stress shielding at the fracture-interface immediately after fracture-fixation delays callus formation and bone healing. Likewise, the tensile stress shielding in the layer of bone underneath the plate can cause osteoporosis and decrease in tensile strength of this layer. In this study a novel forearm internal fracture fixation plate made from short carbon fibre reinforced plastic (CFRP) was used in an attempt to address the problem. Accordingly, it has been possible to analyse the stress distribution in the composite plates using finite-element modelling. A three-dimensional, quarter-symmetric finite element model was generated for the plate system. The stress state in the underlying bone was examined for several loading conditions. Based on the analytical results the composite plate system is likely to reduce stress-shielding effects at the fracture site when subjected to bending and torsional loads. The design of the plate was further optimised by reducing the width around the innermost holes.

  19. Static and Dynamic Differences in Fixation Stability between a Spacer Plate and a Small Stature Plate Fixator Used for High Tibial Osteotomies: A Biomechanical Bone Composite Study

    PubMed Central

    Maas, Stefan; Dueck, Klaus; Pape, Dietrich

    2013-01-01

    Background. The objective of the present study was to compare mechanical strength and stability of the newly designed spacer plate with the gold standard plate for the treatment of medial knee joint osteoarthritis. Materials and Methods. Ten fourth-generation tibial bone composites underwent a medial open-wedge high tibial osteotomy (HTO) according to standard techniques, using five TomoFix plates and five Contour Lock plates. Static compression load to failure and load-controlled cyclical fatigue failure tests were performed. Forces and horizontal displacements were measured; plastic deformations and dynamic stiffness were determined. Results and Discussion. In all samples, rotation of the tibial head and fracture of the opposite cortex were observed. Behaviors of the specimens under static loading were comparable between groups. Cyclic testing revealed lateral significant higher stiffness until failure for the Contour Lock compared to the TomoFix plate. No visible implant failure was observed in any group. Conclusion. Considering the static analysis, both plates offered sufficient stability under physiologic loads of up to 3000 N. The Contour Lock plate-fixated specimens showed a higher stability during the cyclic testing, supposedly due to the wider distance between the fixation screws. PMID:24959357

  20. TIBIOTARSAL COMPRESSION ARTHRODESIS USING A LATERAL LOCKING PLATE

    PubMed Central

    Coughlin, Michael J.; Nery, Caio; Baumfeld, Daniel; Jastifer, James

    2015-01-01

    Objectives: Tibiotalar (TT) arthrodesis is still a very important option in the treatment of primary or post-traumatic arthritis of the ankle but persists the controversy regarding the optimal method for the fixation of the arthrodesis site. No matter the implant used, the goal is to obtain a solid, healthy, pain-free fusion. The purpose of the current study is to present the preliminary results of a novel laterally based tibiotalar compression arthrodesis system using a locked plate. Methods: Thirteen consecutive patients with tibiotalar arthritis were submitted to an arthrodesis using a new lateral plating system. The average age was 59.7 years (range 36~72); nine patients were male and four female. Using a cutting guide, the remaining articular surfaces of the tibia and talus were removed. A compression device was applied to avoid malalignment of the ankle and a precontoured lateral locking plate was used to achieve the joint fusion. Results: Both the AOFAS ankle-hindfoot score and the VAS score improved with the surgery. All patients’ ankles fused by 6 months. In all patients we found a very good alignment in the sagittal, coronal and transverse planes. Conclusion: We believe that a combination of a bilateral compression, contoured bony cuts, and lateral locked plating offers a novel, accurate and useful technique for ankle arthrodesis. PMID:27047874

  1. Late extensor pollicis longus rupture following plate fixation in Galeazzi fracture dislocation.

    PubMed

    Sabat, Dhananjaya; Dabas, Vineet; Dhal, Anil

    2014-07-01

    Late rupture of extensor pollicis longus (EPL) tendon after Galeazzi fracture dislocation fixation is an unknown entity though it is a well-established complication following distal radius fractures. We report the case of a 55-year old male who presented with late EPL tendon rupture 4 months following internal fixation of Galeazzi fracture dislocation with a Locking Compression Plate (LCP). He was managed with extensor indicis proprius (EIP) transfer to restore thumb extension. At 4 years followup, functional result of the transfer was good. We identify possible pitfalls with this particular patient and discuss how to avoid them in future.

  2. Biomechanics of bone-fracture fixation by stiffness-graded plates in comparison with stainless-steel plates

    PubMed Central

    Ganesh, VK; Ramakrishna, K; Ghista, Dhanjoo N

    2005-01-01

    Background In the internal fixation of fractured bone by means of bone-plates fastened to the bone on its tensile surface, an on-going concern has been the excessive stress-shielding of the bone by the excessively-stiff stainless-steel plate. The compressive stress-shielding at the fracture-interface immediately after fracture-fixation delays callus formation and bone healing. Likewise, the tensile stress-shielding of the layer of the bone underneath the plate can cause osteoporosis and decrease in tensile strength of this layer. Method In order to address this problem, we propose to use stiffness-graded plates. Accordingly, we have computed (by finite-element analysis) the stress distribution in the fractured bone fixed by composite plates, whose stiffness is graded both longitudinally and transversely. Results It can be seen that the stiffness-graded composite-plates cause less stress-shielding (as an example: at 50% of the healing stage, stress at the fracture interface is compressive in nature i.e. 0.002 GPa for stainless steel plate whereas stiffness graded plates provides tensile stress of 0.002 GPa. This means that stiffness graded plate is allowing the 50% healed bone to participate in loadings). Stiffness-graded plates are more flexible, and hence permit more bending of the fractured bone. This results in higher compressive stresses induced at the fractured faces accelerate bone-healing. On the other hand, away from the fracture interface the reduced stiffness and elastic modulus of the plate causes the neutral axis of the composite structure to be lowered into the bone resulting in the higher tensile stress in the bone-layer underneath the plate, wherein is conducive to the bone preserving its tensile strength. Conclusion Stiffness graded plates (with in-built variable stiffness) are deemed to offer less stress-shielding to the bone, providing higher compressive stress at the fractured interface (to induce accelerated healing) as well as higher tensile

  3. Current concepts in locking plate fixation of proximal humerus fractures.

    PubMed

    Laux, Christoph J; Grubhofer, Florian; Werner, Clément M L; Simmen, Hans-Peter; Osterhoff, Georg

    2017-09-25

    Despite numerous available treatment strategies, the management of complex proximal humeral fractures remains demanding. Impaired bone quality and considerable comorbidities pose special challenges in the growing aging population. Complications after operative treatment are frequent, in particular loss of reduction with varus malalignment and subsequent screw cutout. Locking plate fixation has become a standard in stabilizing these fractures, but surgical revision rates of up to 25% stagnate at high levels. Therefore, it seems of utmost importance to select the right treatment for the right patient. This article provides an overview of available classification systems, indications for operative treatment, important pathoanatomic principles, and latest surgical strategies in locking plate fixation. The importance of correct reduction of the medial cortices, the use of calcar screws, augmentation with bone cement, double-plate fixation, and auxiliary intramedullary bone graft stabilization are discussed in detail.

  4. Compression capability of cerclage fixation systems. A biomechanical study.

    PubMed

    Shaw, J A; Daubert, H B

    1988-08-01

    Cerclage wire or tension band techniques are frequently complicated by broken wires or inadequate bony stabilization. The fixation capabilities of various cerclage systems were defined in this study by measuring the maximum compression forces generated by the different methods as well as their ultimate strengths. Parham bands and swage-lock titanium cables were found to exhibit the greatest fixation potential and highest ultimate strengths. Cerclage fixation using stainless steel wire was found to be enhanced by using a modified square knot. Mersilene tape was found to have fixation capabilities of similar magnitude to 20 guage stainless wire secured with a twist knot. The polypropylene and nylon cable ties tested showed no advantage when compared to the other systems.

  5. Fixation elements on plate intraocular lens: large positioning holes to improve security of capsular fixation.

    PubMed

    Whiteside, S B; Apple, D J; Peng, Q; Isaacs, R T; Guindi, A; Draughn, R A

    1998-05-01

    This study aimed to evaluate in rabbit eyes the effects of large positioning holes in one-piece silicone plate-haptic intraocular lenses (IOLs) with respect to security of capsular bag fixation. Mechanical strength of capsular fixation is correlated with the histologic findings of regenerating lens material and fibrous tissue ingrowth through the positioning holes on silicone plate IOLs, comparing capsules implanted with large-hole style plate IOLs to fellow capsules implanted with small-hole style plate IOLs. The study design was a prospective, randomized, experimental study. A total of 40 fellow capsular bags from 20 New Zealand white rabbits were examined. Capsules implanted with conventional small-hole silicone plate IOLs were used as the control in all pairs of fellow capsules. Phacoemulsification and implantation of a silicone plate IOL with small positioning holes in one eye and implantation of a silicone plate IOL with large positioning holes in the fellow eye were measured. All rabbits were killed at 2 months. The force required to extract the IOLs from the capsular bag was measured. All capsular bags underwent histopathologic analysis. Extraction force measurements and histopathologic examination, comparing capsules implanted with small-hole plate IOLs with fellow capsules implanted with large-hole plate IOLs, were measured. The large-hole style IOL required significantly more force to extract from the capsular bag compared to the conventional small-hole style (P = 0.003). Histologically, proliferating lens epithelial material and fibrous tissue were observed growing through all of the large positioning holes (synechia formation) but not through any of the small positioning holes. Silicone plate IOLs with large positioning holes become affixed more firmly within the capsular bag compared to conventional small-hole plate IOLs. These findings suggest that large holes in silicone plate IOLs allow for superior capsular bag fixation. This should reduce the

  6. Assessment of function-graded materials as fracture fixation bone-plates under combined loading conditions using finite element modelling.

    PubMed

    Fouad, H

    2011-05-01

    In previous work by Fouad (Medical Engineering and Physics 2010 [23]), 3D finite element (FE) models for fractured bones with function-graded (FG) bone-plates and traditional bone-plates made of stainless steel (SS) and titanium (Ti) alloy were examined under compressive loading conditions using the ABAQUS Code. In this study, the effects of the presence of the torsional load in addition to the compressive load on the predicted stresses of the fracture fixation bone-plate system are examined at different healing stages. The effects on the stress on the fracture site when using contacted and non-contacted bone-plate systems are also studied. The FE modelling results indicate that the torsional load has significant effects on the resultant stress on the fracture fixation bone-plate system, which should be taken into consideration during the design and the analysis. The results also show that the stress shielding at the fracture site decreases significantly when using FG bone-plates compared to Ti alloy or SS bone-plates. The presence of a gap between the bone and the plate results in a remarkable reduction in bone stress shielding at the fracture site. Therefore, the significant effects of using an FG bone-plate with a gap and the presence of torsional load on the resultant stress on the fracture fixation bone-plate system should be taken into consideration.

  7. Conventional bone plate fixation of distal radius and ulna fractures in toy breed dogs.

    PubMed

    Ramírez, J M; Macías, C

    2016-03-01

    To describe the outcome of bone plate fixation of distal radius and ulna fractures in toy breed dogs treated with conventional bone plates. Records of 15 toy breed dogs with distal radius and ulna fractures were retrospectively reviewed for signalment, method of fixation, complications and clinical and radiographic assessments. A telephone-based owner questionnaire was conducted to determine long-term function and client satisfaction. Age ranged from 4 months to 6 years. Body weight ranged from 1 to 4 kg. Dynamic compression plates were used in 13 dogs and veterinary cuttable plates were used in 2 dogs as the means of fixation. Full radiographic and clinical follow-up data were available for 10 dogs and follow-up was performed between 6 and 8 weeks postoperatively. At that time, all fractures had healed and return to function was considered excellent in all 10 dogs. Five dogs did not return for hospital evaluation because they were judged by their owners to be free of lameness. In two cases, owners could not be contacted by telephone, but the referring veterinarians reported the dogs to be asymptomatic. No major complications occurred. Conventional bone plates are suitable choices for stabilisation of distal radius and ulna fractures in toy breed dogs and are not necessarily correlated with high rates of complication. © 2016 Australian Veterinary Association.

  8. Fixation of displaced subcapital femoral fractures. Compression screw fixation versus double divergent pins.

    PubMed

    Christie, J; Howie, C R; Armour, P C

    1988-03-01

    One hundred and twenty-seven consecutive patients with displaced subcapital fractures of the femoral neck (Garden Grade III or IV) all under 80 years of age and independently mobile, were randomly allocated to fixation with either double divergent pins or a single sliding screw-plate device. The incidence of non-union and infection in the sliding screw-plate group was significantly higher, and we believe that when internal fixation is considered appropriate multiple pinning should be used. Mobility after treatment was disappointing in about half of the patients, and we feel that internal fixation can only be justified in patients who are physiologically well preserved and who maintain a high level of activity.

  9. Volar, Dorsal, and Lateral Locking Plate Fixation for Pilon Fractures.

    PubMed

    Henry, Mark

    2017-03-01

    The more common dorsal fracture subluxations at the base of the middle phalanx have an intact dorsal buttress of articular surface in continuity with the shaft. Capitalizing on this foundation, various fixation methods have met with relatively equivalent success including Kirschner wires, screws only, nonlocking plate and screws, and external fixation. Pilon fractures are complete articular fractures, where the comminuted articular fragments lack any structural connection to the more distal shaft of the middle phalanx, and have largely relied upon external fixation traction systems. The theoretical concept is that axial distraction prevents articular collapse and that the surrounding soft tissue envelope acts to gather the articular fragments; the term "ligamentotaxis" is often applied. Most constructs are founded on a transverse wire through the axis of rotation in the head of the proximal phalanx with the idea that patients will pursue active motion, termed "dynamic fixation." In practice, patients find it difficult to move well while the construct is in place and have rarely achieved much range by the time of removal. These cases are prone to loss of articular reduction leading to posttraumatic arthritis, substantial proximal interphalangeal joint stiffness, and pin-tract infection. Such problems are solved with locking plates that support the articular reduction throughout healing and permit immediate range of motion while avoiding other complications such as pin-tract infection. Outcomes are reported for 40 patients treated with locking plates applied from volar, dorsal, and lateral to treat pilon fractures.

  10. Plate fixation of prostheses after segmental resection for bone tumours.

    PubMed

    Coathup, M J; Cobb, J P; Walker, P S; Blunn, G W

    2000-11-01

    This study investigated the concept of using plates to attach endoprostheses to bone after segmental resection for bone tumours in an animal model. Titanium alloy plates integrated with the prosthesis and coated with hydroxyapatite were attached to bone by screws. This type of uncemented fixation relied on the induction of periosteal bone formation into and around the plates to secure the implant to bone. Two, three, and six-slotted plate designs were investigated. On retrieval, each plate was securely fixed by new bone. Bone apposition on the external surface of the plates occurred through a combination of periosteal bone production, invasion of bone through slots in the plate, and bone growth over the ends of the plates. Most plates became incorporated into a remodelled cortex. Higher bone turnover rates (microm day(-1)) were seen in bone in the slots of the plate compared with normal cortical bone turnover (p < 0.05). Significantly higher rates of turnover were measured beneath slotted parts of the plates compared with regions below the unslotted parts (p < 0.05). The cross-sectional area of bone surrounding the six-plate implant design was significantly higher than that of the three-plate (p < 0.05) and two-plate (p < 0.05) designs. In addition, significantly more bone formed adjacent to the six-plated implant design compared with that in the contralateral limb (p = 0.002). However, no significant difference was found when the total cortical area around the three-plated design was compared with that of the contralateral limb (p = 0.63). In contrast, significantly less bone was measured adjacent to the two-plate design than in the untreated limb (p = 0.001). Image analysis also demonstrated increased cortical porosity adjacent to the six-plate design compared with the three-plate (p = 0.004) and two-plate (p < 0.05) designs. Finite element analysis demonstrated that the six and three-plate designs increased the second moment of area compared with that in the

  11. Finite Element Analysis of Sacroiliac Joint Fixation under Compression Loads

    PubMed Central

    Bruna-Rosso, Claire; Arnoux, Pierre-Jean; Bianco, Rohan-Jean; Godio-Raboutet, Yves; Fradet, Léo

    2016-01-01

    Background Sacroiliac joint (SIJ) is a known chronic pain-generator. The last resort of treatment is the arthrodesis. Different implants allow fixation of the joint, but to date there is no tool to analyze their influence on the SIJ biomechanics under physiological loads. The objective was to develop a computational model to biomechanically analyze different parameters of the stable SIJ fixation instrumentation. Methods A comprehensive finite element model (FEM) of the pelvis was built with detailed SIJ representation. Bone and sacroiliac joint ligament material properties were calibrated against experimentally acquired load-displacement data of the SIJ. Model evaluation was performed with experimental load-displacement measurements of instrumented cadaveric SIJ. Then six fixation scenarios with one or two implants on one side with two different trajectories (proximal, distal) were simulated and assessed with the FEM under vertical compression loads. Results The simulated S1 endplate displacement reduction achieved with the fixation devices was within 3% of the experimentally measured data. Under compression loads, the uninstrumented sacrum exhibited mainly a rotation motion (nutation) of 1.38° and 2.80° respectively at 600 N and 1000 N, with a combined relative translation (0.3 mm). The instrumentation with one screw reduced the local displacement within the SIJ by up to 62.5% for the proximal trajectory vs. 15.6% for the distal trajectory. Adding a second implant had no significant additional effect. Conclusion A comprehensive finite element model was developed to assess the biomechanics of SIJ fixation. SIJ devices enable to reduce the motion, mainly rotational, between the sacrum and ilium. Positioning the implant farther from the SIJ instantaneous rotation center was an important factor to reduce the intra-articular displacement. Clinical relevance Knowledge provided by this biomechanical study enables improvement of SIJ fixation through optimal implant

  12. Fixation of zygomatic and mandibular fractures with biodegradable plates

    PubMed Central

    Degala, Saikrishna; Shetty, Sujeeth; Ramya, S

    2013-01-01

    Context: In this prospective study, 13 randomly selected patients underwent treatment for zygomatic–complex fractures (2 site fractures) and mandibular fractures using 1.5 / 2 / 2.5-mm INION CPS biodegradable plates and screws. Aims: To assess the fixation of zygomatic-complex and mandibular fractures with biodegradable copolymer osteosynthesis system. Materials and Methods: In randomly selected 13 patients, zygomatic-complex and mandibular fractures were plated using resorbable plates and screws using Champy's principle. All the cases were evaluated clinically and radiologically for the type of fracture, need for the intermaxillary fixation (IMF) and its duration, duration of surgery, fixation at operation, state of reduction at operation, state of bone union after operation, anatomic reduction, paresthesia, occlusal discrepancies, soft tissue infection, immediate and late inflammatory reactions related to biodegradation process, and any need for the removal of the plates. Statistical Analysis Used: Descriptives, Frequencies, and Chi-square test were used. Results: In our study, the age group range was 5 to 55 years. Road traffic accidents accounted for the majority of patients six, (46.2%). Postoperative occlusal discrepancies were found in seven patients as mild to moderate, which resolved with IMF for 1-8 weeks. There were minimal complications seen and only as soft tissue infection. Conclusions: Use of biodegradable osteosynthesis system is a reliable alternative method for the fixation of zygomatic-complex and mandibular fractures. The biodegradable system still needs to be refined in material quality and handling to match the stability achieved with metal system. Biodegradable plates and screws is an ideal system for pediatric fractures with favorable outcome. PMID:23662255

  13. Influence of hooks and a lag screw on internal fixation plates for lateral malleolar fracture: a biomechanical and ergonomic study.

    PubMed

    Sakai, Rina; Uchino, Masataka; Yoneo, Terumasa; Ohtaki, Yasuaki; Minehara, Hiroaki; Matsuura, Terumasa; Gomi, Tsutomu; Ujihira, Masanobu

    2017-02-23

    For internal fixation of AO classification Type B lateral malleolar fracture, insertion of lag screws into the fracture plane and fixation with a one-third tubular plate as a neutralization plate are the standard treatment procedures. The one-third tubular plate is processed to a hook shape and hung on the distal end of the fibula. In this study, to compare the function of the hook and lag screws of a one-third tubular plate and LCP for osteosynthesis of lateral malleolar fracture, mechanical indices of internal fixation were compared among the one-third tubular plates with lag screws with and without the hook and a locking compression plate. As mechanical tests, a compression test was performed in which compression in the bone axis direction produced by supporting the body weight was simulated, and a torsion test was performed in which external rotation of the bone axis caused by plantar flexion of the ankle joint was simulated. Muscle strength during walking and the force and torque acting on the ankle and knee joints were determined using inverse dynamic analysis. Finite element analysis was performed to analyze the function of hooks and lag screws. The joint reaction force determined by inverse dynamic analysis was adopted as the loading condition of finite element analysis. A stiffness equivalent to that of healthy bone could be achieved by all three internal fixations. It was clarified that the presence of the hook does not make a difference in stiffness. Displacement of the one-third tubular plate was small regardless of the presence or absence of the hook compared with those of locking compression plates. The presence of the hook did not make any difference in stiffness, suggesting that active preparation of the hook is unnecessary. We also clarified that lag screws inhibit displacement.

  14. Reasons why dynamic compression plates are inferior to locking plates in osteoporotic bone: a finite element explanation.

    PubMed

    MacLeod, Alisdair R; Simpson, A Hamish R W; Pankaj, Pankaj

    2015-01-01

    While locking plate fixation is becoming increasingly popular for complex and osteoporotic fractures, for many indications compression plating remains the standard choice. This study compares the mechanical behaviour of the more recent locking compression plate (LCP) device, with the traditional dynamic compression plates (DCPs) in bone of varying quality using finite element modelling. The bone properties considered include orthotropy, inhomogeneity, cortical thinning and periosteal apposition associated with osteoporosis. The effect of preloads induced by compression plating was included in the models. Two different fracture scenarios were modelled: one with complete reduction and one with a fracture gap. The results show that the preload arising in DCPs results in large principal strains in the bone all around the perimeter of the screw hole, whereas for LCPs large principal strains occur primarily on the side of the screw proximal to the load. The strains within the bone produced by the two screw types are similar in healthy bone with a reduced fracture gap; however, the DCP produces much larger strains in osteoporotic bone. In the presence of a fracture gap, the DCP results in a considerably larger region with high tensile strains and a slightly smaller region with high compressive strains. These findings provide a biomechanical basis for the reported improved performance of locking plates in poorer bone quality.

  15. Comparison of crossed screw versus plate fixation for radial neck fractures.

    PubMed

    Gutowski, Christina J; Darvish, Kurosh; Ilyas, Asif M; Jones, Christopher M

    2015-11-01

    Fixation of radial neck fractures can be achieved with a plate and screw construct or, in absence of comminution, with two obliquely-oriented screws. This study investigated the mechanical properties, specifically the stiffness and load to failure, of these two fixation strategies in a cadaver model. Ten matched-pair radii were removed from fresh cadaver arms. A transverse osteotomy was created at the neck of each radius. Right-sided radii were fixed with two oblique headless compression screws; left-sided radii were fixed with a radial neck plate. The distal aspect of each radius was potted in urethane casting resin. The radial head was loaded in shear in 4 different planes (medial to lateral, lateral to medial, posterior to anterior, and anterior to posterior) using an Instron machine. Stiffness and load to failure were recorded. The stiffness of both constructs was similar in all planes except for loading from medial to lateral where the screw construct was 1.8 times stiffer. Average ultimate failure occurred at 229N for the screws and 206N for the plate. Failure strength was not statistically different. However, mode of failure differed for both fixation constructs, the plate failed in bending while the screws failed by pullout and fracture. The two strategies provide similar strength and stiffness for the fixation of transverse, non-comminuted radial neck fractures. While plate and screw constructs are more appropriate for axially unstable or comminuted fractures, two oblique screws might be preferred for simple transverse neck fractures since this strategy requires less exposure and the implant is buried. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Locking-plate osteosynthesis versus intramedullary nailing for fixation of olecranon fractures: a biomechanical study.

    PubMed

    Nowak, Tobias E; Burkhart, Klaus J; Andres, Torsten; Dietz, Sven O; Klitscher, Daniela; Mueller, Lars P; Rommens, Pol M

    2013-05-01

    Intramedullary nailing and locked plating for fixation of olecranon fractures has recently gained popularity. However, these two new technologies have not been compared for their biomechanical efficacy. The aim of this study was to evaluate the biomechanical stability of two newly designed fracture fixation devices for treating olecranon fractures during dynamic continuous loading: the ION intramedullary locking nail and the LCP precontoured locking compression plate. Simulated oblique olecranon fractures were created in eight pairs of fresh-frozen cadaver ulnae and stabilised using either the LCP or ION. Specimens were then subjected to continuous dynamic loading (from 25 to 200 N), with a continuous angle alteration between 0° and 90° of flexion, to perform a matched-pairs comparison. Significant differences in the distance between markers surrounding the fracture gap was determined using the Wilcoxon test after four and 300 loading cycles. The ION resulted in significantly less displacement in the fracture gap at 0° extension (P = 0.036), 45° flexion (P = 0.035) and 90° flexion (P = 0.017) after 300 cycles of continuous loading. The measured displacements were small and were probably not of clinical significance. No mechanical failure or hardware migration was seen with either fixation technique. This study shows significantly less micromotion for the ION than for the LCP in treating oblique olecranon fractures after 300 cycles of dynamic loading. Both implant types could be appropriate surgical techniques for fixation of selected olecranon fractures and osteotomies.

  17. Stoppa Approach for Anterior Plate Fixation in Unstable Pelvic Ring Injury

    PubMed Central

    Choo, Suk Kyu; Kim, Jung-Jae; Lee, Mark

    2016-01-01

    Background The Stoppa (intrapelvic) approach has been introduced for the treatment of pelvic-acetabular fractures; it allows easy exposure of the pelvic brim, where the bone quality is optimal for screw fixation. The purpose of our study was to investigate the surgical outcomes of unstable pelvic ring injuries treated using the Stoppa approach for stable anterior ring fixation. Methods We analyzed 22 cases of unstable pelvic ring injury treated with plate fixation of the anterior ring with the Stoppa approach. We excluded cases of nondisplaced rami fracture, simple symphyseal diastasis, and parasymphyseal fractures, which can be easily treated with other techniques. The average age of the study patients was 41 years (range, 23 to 61 years). There were 10 males and 12 females. According to the Young and Burgess classification, there were 12 lateral compression, 4 anteroposterior compression, and 6 vertical shear fracture patterns. The fracture location on the anterior ring was near the iliopectineal eminence in all cases and exposure of the pelvic brim was required for plate fixation. All patients were placed in the supine position. For anterior plate fixation, all screws were applied to the anterior ramus distally and directed above the hip joint proximally. Radiologic outcomes were assessed by union time and quality of reduction by Matta method. The Merle d'Aubigne-Postel score was used to evaluate the functional results. Results The average radiologic follow-up period was 16 months (range, 10 to 51 months). All fractures united at an average of 3.5 months (range, 3 to 5 months). According to the Matta method, the quality of reduction was classified as follows: 16 anatomical (73%) and 6 nearly anatomical (27%) reductions. There were no cases of screw or implant loosening before bone healing. The functional results were classified as 7 excellent (32%), 12 good (55%), and 3 fair (13%) by the Merle d'Aubigne-Postel score. There were no wound complications

  18. Plate osteosynthesis of fractures of the shaft of the humerus: comparison of limited contact dynamic compression plates and locking compression plates.

    PubMed

    Singh, Ashutosh Kumar; Narsaria, Nidhi; Seth, R R; Garg, S

    2014-06-01

    The aim of this retrospective study was to compare outcomes and complications of displaced fractures of the shaft of the humerus treated with limited-contact dynamic compression plates (LCDCPs) and locking compression plates (LCPs). Two hundred and twelve patients with displaced fractures of the shaft of the humerus, treated with plate osteosynthesis from January 2005 to December 2009 were reviewed. One hundred and two patients (group A) were treated with LCDCP osteosynthesis and 110 patients (group B) were treated with LCP osteosynthesis. Clinical and radiological assessments were made at monthly intervals for the first 6 months and then at 2-month intervals for the next 6 months. Primary outcome measures like operative time, duration of hospital stay, time to fracture union, union rate and secondary outcome measures (functional outcome and complications such as infection, malunion, delayed union, nonunion, implant failure and iatrogenic radial nerve palsy) were compared between both groups. The ULCA scoring system and Mayo elbow performance index (MEPI) were used to assess shoulder and elbow functions, respectively. Rodriguez-Merchan criteria were used to assess the functional outcomes of the fracture fixation. There was no significant difference found between the two groups in terms of primary outcome measures. According to Rodriguez-Merchan criteria, comparison of functional outcomes of both groups showed insignificant difference (p = 0.48). There was no significant difference found between the two groups regarding mean ULCA score (p = 0.34) and mean MEPI sore (p = 0.54). In terms of complications, no significant difference was found between the two groups. This study concludes that the principle of fracture fixation was more important than plate selection in fractures of the shaft of the humerus. Level 3.

  19. Stability of extraoral vertical ramus osteotomy: plate fixation versus maxillomandibular/skeletal suspension wire fixation.

    PubMed

    Mobarak, K A; Krogstad, O; Espeland, L; Lyberg, T

    2000-01-01

    The objective of this cephalometric study was to evaluate skeletal stability and time course of postoperative changes in 2 groups of mandibular prognathism patients following extraoral oblique vertical ramus osteotomy (VRO). One group (n = 22) received maxillomandibular fixation and skeletal suspension wires (MMF group) for a period of 8 weeks. In the other group (n = 22), the segments were rigidly fixed with plates and the patients were allowed to function immediately after surgery. Lateral cephalograms were taken on 5 occasions: immediately presurgical, immediately postsurgical, 8 weeks postsurgical, 6 months postsurgical, and 1 year postsurgical. During the first 8 weeks after surgery, the MMF group demonstrated posterior movement of the mandible, with an increase in mandibular plane angle, shortening of the rami, and dental compensations. Upon release of MMF and skeletal suspension wiring, a small anterior relapse tendency was observed, but the net setback 1 year after surgery was still greater than the actual surgical setback. In the plate fixation group, postoperative changes were mainly in the form of a small anterior relapse tendency in the range of 10% of the surgical setback. The results indicate that the use of plate fixation with VRO, while eliminating the inconvenience for the patient of several weeks of MMF and preventing the early side effects observed in the MMF group, also resulted in a more predictable surgical procedure, with excellent stability 1 year after surgery.

  20. Locking versus nonlocking palmar plate fixation of distal radius fractures.

    PubMed

    Osti, Michael; Mittler, Christoph; Zinnecker, Richard; Westreicher, Christoph; Allhoff, Clemens; Benedetto, Karl Peter

    2012-11-01

    This study compared functional and radiological outcomes after treatment of extension-type distal radius fractures with conventional titanium nonlocking T-plates or titanium 1.5-mm locking plates. A total of 60 patients were included and followed for 4 to 7 years after receiving nonlocking T-plates (group A; n=30) or locking plates (group B; n=30) with and without dorsal bone grafting. Bone grafting was significantly more often performed in the nonlocking group to increase dorsal fracture fixation and stability (P<.003). Pre- and postoperative and follow-up values for palmar tilt, radial inclination, radial shortening, and ulnar variance were recorded. Age, sex, and fracture type were similarly distributed between the 2 groups. Postoperative and follow-up evaluation revealed equal allocation of intra-articular step formation and osteoarthritic changes to both groups. The overall complication rate was 25%. Compared with the nonlocking system, patients undergoing locking plate fixation presented with statistically significantly better values for postoperative palmar tilt (5.53° vs 8.15°; P<.02) and radial inclination (22.13° vs 25.03°; P<.02). However, forearm pronation was significantly better in group A (P<.005). At follow-up, radial inclination tended to approach a statistically significant difference in favor of group B. All clinical assessment, including Mayo wrist score, Disabilities of the Arm, Shoulder, and Hand score, Green and O'Brien score, Gartland and Werley score, visual analog scale score, and grip strength, yielded no statistically significant difference between the 2 groups. Locking plates seem to provide benefits regarding surgical technique and comfort, improvement in implant anchorage (especially in osteoporotic bone), and reduce the necessity of additional bone grafting. Copyright 2012, SLACK Incorporated.

  1. Osteotomy, compression and other modifications of surgical techniques for internal fixation of extracapsular hip fractures.

    PubMed

    Parker, Martyn J; Handoll, Helen H G

    2009-04-15

    Many different surgical techniques have been described for the internal fixation of extracapsular hip fractures. To compare different aspects of surgical technique used in operations for internal fixation of extracapsular hip fractures in adults. We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (January 2008), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2008, Issue 1), MEDLINE, EMBASE, CINAHL, Current Controlled Trials, orthopaedic journals, conference proceedings and reference lists of articles. Date of last search was January 2008. No language restriction was applied. All randomised and quasi-randomised trials investigating operative techniques used in operations for the treatment of extracapsular hip fractures in adults. Two review authors independently selected trials, assessed trial quality and extracted data. Wherever appropriate, data were pooled. Predominantly older people with trochanteric fractures were treated in the 11 included trials.One trial (65 participants undergoing fixation with a fixed nail-plate) found no statistically significant differences between osteotomy versus anatomical reduction. Four trials, involving 465 participants undergoing fixation with a sliding hip screw (SHS), compared osteotomy versus anatomical reduction. Osteotomy was associated with an increased operative blood loss and length of surgery. There were no statistically significant differences for mortality, morbidity or measures of anatomical deformity.Two trials (138 participants) compared SHS fixation of a trochanteric hip fracture augmented with cement against a standard fixation. There were no reoperations even for the four cases of fixation failure in the cement group. The cement group had significantly better quality of life scores at six months. One trial (200 participants) comparing compression versus no compression of a trochanteric fracture in conjunction with SHS fixation found no significant

  2. Compression behavior of delaminated composite plates

    NASA Technical Reports Server (NTRS)

    Peck, Scott O.; Springer, George S.

    1989-01-01

    The response of delaminated composite plates to compressive in-plane loads was investigated. The delaminated region may be either circular or elliptical, and may be located between any two plies of the laminate. For elliptical delaminations, the axes of the ellipse may be arbitrarily oriented with respect to the applied loads. A model was developed that describes the stresses, strains, and deformation of the sublaminate created by the delamination. The mathematical model is based on a two dimensional nonlinear plate theory that includes the effects of transverse shear deformation. The model takes into account thermal and moisture induced strains, transverse pressures acting on the sublaminate, and contact between the sublaminate and plate. The solution technique used is the Ritz method. A computationally efficient computer implementation of the model was developed. The code can be used to predict the nonlinear-load-strain behavior of the sublaminate including the buckling load, postbuckling behavior, and the onset of delamination growth. The accuracy of the code was evaluated by comparing the model results to benchmark analytical solutions. A series of experiments was conducted on Fiberite T300/976 graphite/epoxy laminates bonded to an aluminum honeycomb core forming a sandwich panel. Either circles or ellipses made from Teflon film were embedded in the laminates, simulating the presence of a delamination. Each specimen was loaded in compression and the strain history of the sublaminate was recorded far into the postbuckling regime. The extent of delamination growth was evaluated by C-scan examination of each specimen. The experimental data were compared to code predictions. The code was found to describe the data with reasonable accuracy. A sensitivity study examined the relative importance of various material properties, the delamination dimensions, the contact model, the transverse pressure differential, the critical strain energy release rate, and the relative

  3. Compressive strength of damaged and repaired composite plates

    NASA Technical Reports Server (NTRS)

    Finn, Scott R.; Springer, George S.

    1992-01-01

    Tests were performed assessing the effectiveness of repair in restoring the mechanical properties of damaged, solid composite plates made of Fiberite T300/976 graphite-epoxy. Some (75%) or all (100%) of the damaged zone was cut out, and the plate was repaired by plugging and patching the hole. The effectiveness of the repair was evaluated by measuring the compressive strengths of undamaged plates, damaged plates with no cutout, damaged plates with a cutout, and plates that had been repaired.

  4. Biomechanical Comparison of External Fixation and Compression Screws for Transverse Tarsal Joint Arthrodesis.

    PubMed

    Latt, L Daniel; Glisson, Richard R; Adams, Samuel B; Schuh, Reinhard; Narron, John A; Easley, Mark E

    2015-10-01

    Transverse tarsal joint arthrodesis is commonly performed in the operative treatment of hindfoot arthritis and acquired flatfoot deformity. While fixation is typically achieved using screws, failure to obtain and maintain joint compression sometimes occurs, potentially leading to nonunion. External fixation is an alternate method of achieving arthrodesis site compression and has the advantage of allowing postoperative compression adjustment when necessary. However, its performance relative to standard screw fixation has not been quantified in this application. We hypothesized that external fixation could provide transverse tarsal joint compression exceeding that possible with screw fixation. Transverse tarsal joint fixation was performed sequentially, first with a circular external fixator and then with compression screws, on 9 fresh-frozen cadaveric legs. The external fixator was attached in abutting rings fixed to the tibia and the hindfoot and a third anterior ring parallel to the hindfoot ring using transverse wires and half-pins in the tibial diaphysis, calcaneus, and metatarsals. Screw fixation comprised two 4.3 mm headless compression screws traversing the talonavicular joint and 1 across the calcaneocuboid joint. Compressive forces generated during incremental fixator foot ring displacement to 20 mm and incremental screw tightening were measured using a custom-fabricated instrumented miniature external fixator spanning the transverse tarsal joint. The maximum compressive force generated by the external fixator averaged 186% of that produced by the screws (range, 104%-391%). Fixator compression surpassed that obtainable with screws at 12 mm of ring displacement and decreased when the tibial ring was detached. No correlation was found between bone density and the compressive force achievable by either fusion method. The compression across the transverse tarsal joint that can be obtained with a circular external fixator including a tibial ring exceeds that

  5. Fixation of supracondylar femoral fractures following total knee arthroplasty: is there any difference comparing angular stable plate fixation versus rigid interlocking nail fixation?

    PubMed

    Aldrian, Silke; Schuster, Rupert; Haas, Nicole; Erhart, Jochen; Strickner, Markus; Blutsch, Beate; Wernhart, Simon; Leitgeb, Johannes; Platzer, Patrick

    2013-07-01

    Literature does not provide any reliable comparison between angular stable plate fixation and rigid nail fixation for stabilization of supracondylar periprosthetic femoral fractures. Thus, the purpose of this study was to compare these two implants in clinical practice relating to fracture healing, functional results and treatment-related complications. In this retrospective study (level IV), clinical and radiographic records of 86 patients (62 female and 24 male, average age: 75.6) with supracondylar periprosthetic femoral fractures between 1996 and 2010 were analyzed. 48 patients underwent lateral plate fixation by an angular stable plate system (LISS), whereas 38 patients were stabilized by a rigid interlocking nail device. Sixty-four (76 %) patients returned to their pre-injury activity level and were satisfied with their clinical outcome. We had an overall Oxford outcome score of 2.21, with patients following angular stable plate fixation of 2.22, and patients after rigid nail fixation of 2.20. Successful fracture healing within 6 months was achieved in 74 (88 %) patients. Comparing between plate fixation and nail fixation, statistical analysis did not reveal any significant differences. Overall, we had a relatively high rate of fracture healing and a satisfactory functional outcome with both implants. Both methods of fixation showed similar results relating to the functional outcome and individual satisfaction of the patients. However, with regards to fracture healing and treatment-related complications, intramedullary nail fixation showed slight advantages.

  6. Biomechanical Property of a Newly Designed Assembly Locking Compression Plate: Three-Dimensional Finite Element Analysis

    PubMed Central

    Liu, Da

    2017-01-01

    In this study, we developed and validated a refined three-dimensional finite element model of middle femoral comminuted fracture to compare the biomechanical stability after two kinds of plate fixation: a newly designed assembly locking compression plate (NALCP) and a locking compression plate (LCP). CT data of a male volunteer was converted to middle femoral comminuted fracture finite element analysis model. The fracture was fixated by NALCP and LCP. Stress distributions were observed. Under slow walking load and torsion load, the stress distribution tendency of the two plates was roughly uniform. The anterolateral femur was the tension stress area, and the bone block shifted toward the anterolateral femur. Maximum stress was found on the lateral border of the number 5 countersink of the plate. Under a slow walking load, the NALCP maximum stress was 2.160e+03 MPa and the LCP was 8.561e+02 MPa. Under torsion load, the NALCP maximum stress was 2.260e+03 MPa and the LCP was 6.813e+02 MPa. Based on those results of finite element analysis, the NALCP can provide adequate mechanical stability for comminuted fractures, which would help fixate the bone block and promote bone healing.

  7. Intramedullary Nailing of Open Tibial Fractures: Provisional Plate Fixation.

    PubMed

    Ludwig, Meryl; Hymes, Robert A; Schulman, Jeff; Pitta, Michael; Ramsey, Lolita

    2016-09-01

    Tibia fracture is the most common type of long bone fracture, and intramedullary nailing is the preferred treatment. In open fractures, a provisional plate is often used to maintain reduction. It is unknown whether this practice increases the risk of infection or other complications. This study retrospectively compared patients who were treated at a level 1 trauma center with intramedullary nailing of an open tibia fracture. Patients who were included: (1) were 18 years or older; (2) were treated between January 1, 2005, and June 30, 2013; (3) had an open fracture of the tibia; and (4) were treated operatively with intramedullary nailing, with or without provisional plate fixation. Patient sex, history of diabetes, history of smoking, mechanism of injury, and side of injury were analyzed. Postoperative complications included infection, delayed union or non-union, compartment syndrome, and death. After the authors controlled for age, Gustilo-Anderson type, and AO/Orthopaedic Trauma Association classification, they found that provisional plate use did not significantly increase the risk of infection (adjusted odds ratio, 1.64; 95% confidence interval, 0.51-5.32; P=.41) or any other complications (adjusted odds ratio, 1.24; 95% confidence interval, 0.46-3.35; P=.67). In the subgroup of patients who had a provisional plate (n=35), removal of the plate did not significantly decrease the risk of infection (adjusted odds ratio, 0.43; 95% confidence interval, 0.07-2.69; P=.36) or other complications (adjusted odds ratio, 0.55; 95% confidence interval, 0.12-2.46; P=.44). In open tibia fractures treated with intramedullary nailing, provisional plate stabilization, a valuable reduction aid, did not increase the risk of infection or other complications. Because of the small subgroup size, however, definitive conclusions cannot be drawn about removal of these provisional plates. [Orthopedics. 2016; 39(5):e931-e936.]. Copyright 2016, SLACK Incorporated.

  8. Plate fixation of odontoid fractures without C1-C2 arthrodesis: practice of a novel surgical technique for stabilization of odontoid fractures, including the opportunity to extend the fixation to C3.

    PubMed

    Platzer, Patrick; Thalhammer, Gerhild; Krumboeck, Anna; Schuster, Rupert; Kutscha-Lissberg, Florian; Zehetgruber, Isabella; Braunsteiner, Thomas; Vécsei, Vilmos

    2009-04-01

    Surgical treatment of odontoid fractures that do not allow interfragmentary fracture compression involves either posterior atlantoaxial arthrodesis or additional anterior stabilization using a plate construct. The purpose of this study was to determine the clinical and radiographic outcome after anterior plate fixation of odontoid fractures that were not suitable for anterior screw fixation. We reviewed the clinical and radiographic records of 9 patients with an average age of 54 years at the time of surgery who had undergone anterior plate fixation of an odontoid fracture. Indications for using a plate construct were odontoid fractures with anterior oblique fracture lines, fractures with comminution or major displacement, and pathological fractures. Eight patients returned to their preinjury activity level and were satisfied with their treatment. One patient reported chronic pain symptoms and a notable decrease in cervical spine motion. Using the Smiley-Webster Scale to quantify their clinical outcome, we achieved an overall outcome score of 1.6. Bony fusion was achieved in all patients. Reduction or fixation failed in 2 patients. Reoperation for technical failures was not necessary in any of the patients. We had promising results using anterior plate fixation for surgical treatment of odontoid fractures that did not allow interfragmentary fracture compression. Because this method avoids the rigid fixation of the atlantoaxial joint in contrast to techniques of posterior cervical arthrodesis, it seems to be a practical option for the management of fracture types that require additional stabilization of the odontoid.

  9. Fixation of diaphyseal fractures with a segmental defect: a biomechanical comparison of locked and conventional plating techniques.

    PubMed

    Fulkerson, Eric; Egol, Kenneth A; Kubiak, Erik N; Liporace, Frank; Kummer, Frederick J; Koval, Kenneth J

    2006-04-01

    Locking plates are an alternative to conventional compression plate fixation for diaphyseal fractures. The objective of this study was to compare the stability of various plating with locked screw constructs to conventional nonlocked screws for fixation of a comminuted diaphyseal fracture model using a uniform, synthetic ulna. Locked screw construct variables were the use of unicortical or bicortical screws, and increasing bone to plate distance. This biomechanical study compared various construct groups after cyclic axial loading and three-point bending. Results were analyzed via one-way analysis of variance. Displacements after cyclical axial loading and number of cycles to failure in cyclic bending were used to assess construct stability. The constructs fixed by plates with bicortical locked screws withstood significantly more cycles to failure than the other constructs (p < 0.001). Significantly less displacement occurred after axial loading with bicortical locked screws than with bicortical nonlocked screws. Increased distance of the plate from the bone surface, and use of unicortical locked screws led to early failure with cyclic loading for constructs with locked screws. These results support the use of plating with bicortical locked screws as an alternative to conventional plating for comminuted diaphyseal fractures in osteoporotic bone. Bicortical locked screws with minimal displacement from the bone surface provide the most stable construct in the tested synthetic comminuted diaphyseal fracture model. The results of this study suggest use of plates with unicortical screws for the described fracture is not recommended.

  10. Optimal side plate fixation for unstable intertrochanteric hip fractures.

    PubMed

    Yian, E H; Banerji, I; Matthews, L S

    1997-05-01

    To quantitatively determine the minimal screw number needed for stable side plate fixation to the femoral shaft in treating unstable intertrochanteric hip fractures. Laboratory/biomedics study. Orthopaedic biomechanics laboratory. The convenience sample was made up of one saw bone, one steel pipe, and ten human cadaveric femur specimens. Human specimens were selected by ruling out pathology and excess osteopenia. Ten specimens were tested to completion. Telescoping hip screw and hip screw side plate secured with various numbered combinations of side plate screws. Decreases in tension experienced by all previously inserted screws when an additional screw was applied were recorded and labeled as "protection." Protection offered by a third screw on all previous screws was 787.3 newtons in the steel pipemodel, 71.2 newtons in the sawbone model, and 158.3 newtons in the human model (p < 0.005). A fourth bone screw did not decrease tension in previous screws by more than 11 newtons. The protective effect of the fourth screw on screw #3 increased with decreasing screw application torque by a maximum of 21.8 newtons (p < 0.005). This study suggests that three bone screws provide an optimal distribution of tensile forces. The insertional torque used to place screws, once screw-plate contact has been established, does not play a significant role in screw protection. Additional studies are needed to assess the role of cortical bone density, and cyclical loading and bending forces experienced by the side plate screws, before definite clinical recommendations can be made.

  11. A comparative in vitro study of fixation of mandibular fractures with paraskeletal clamps or screw plates.

    PubMed

    Crofts, C E; Trowbridge, A; Maung Aung, T; Brook, I M

    1990-05-01

    The use of porcine rib pairs as an in vitro analog for the edentulous mandible is described. Using this model, the relative degree of fixation achieved with a screw plate (Champy) and a paraskeletal clamp plate (Mennen) has been evaluated. The fractured plated ribs failed at significantly lower bending forces than the non-sectioned controls. However, no statistically significant difference in force at failure between the two different methods of plate fixation could be demonstrated.

  12. A biomechanical comparison of conventional dynamic compression plates and string-of-pearls™ locking plates using cantilever bending in a canine Ilial fracture model.

    PubMed

    Kenzig, Allison R; Butler, James R; Priddy, Lauren B; Lacy, Kristen R; Elder, Steven H

    2017-07-13

    Fracture of the ilium is common orthopedic injury that often requires surgical stabilization in canine patients. Of the various methods of surgical stabilization available, application of a lateral bone plate to the ilium is the most common method of fixation. Many plating options are available, each having its own advantages and disadvantages. The purpose of this study was to evaluate the biomechanical properties of a 3.5 mm String-of-Pearls™ plate and a 3.5 mm dynamic compression plate in a cadaveric canine ilial fracture model. Hemipelves were tested in cantilever bending to failure and construct stiffness, yield load, displacement at yield, ultimate load, and mode of failure were compared. The mean stiffness of dynamic compression plate (116 ± 47 N/mm) and String-of-Pearls™ plate (107 ± 18 N/mm) constructs, mean yield load of dynamic compression plate (793 ± 333 N) and String-of-Pearls™ plate (860 ± 207 N) constructs, mean displacement at yield of dynamic compression plate (8.6 ± 3.0 mm) and String-of-Pearls™ plate (10.2 ± 2.8 mm) constructs, and ultimate load at failure of dynamic compression plate (936 ± 320 N) and String-of-Pearls™ plate (939 ± 191 N) constructs were not significantly different. No differences were found between constructs with respect to mode of failure. No significant biomechanical differences were found between String-of-Pearls™ plate and dynamic compression plate constructs in this simplified cadaveric canine ilial fracture model.

  13. Investigation of the mechanical properties and failure modes of hybrid natural fiber composites for potential bone fracture fixation plates.

    PubMed

    Manteghi, Saeed; Mahboob, Zia; Fawaz, Zouheir; Bougherara, Habiba

    2017-01-01

    The purpose of this study is to investigate the mechanical feasibility of a hybrid Glass/Flax/Epoxy composite material for bone fracture fixation such as fracture plates. These hybrid composite plates have a sandwich structure in which the outer layers are made of Glass/Epoxy and the core from Flax/Epoxy. This configuration resulted in a unique structure compared to prior composites proposed for similar clinical applications. In order to evaluate the mechanical properties of this hybrid composite, uniaxial tension, compression, three-point bending and Rockwell Hardness tests were conducted. In addition, water absorption tests were performed to investigate the rate of water absorption for the specimens. This study confirms that the proposed hybrid composite plates are significantly more flexible axially compared to conventional metallic plates. Furthermore, they have considerably higher ultimate strength in tension, compression and flexion. Such high strength will ensure good stability of bone-implant construct at the fracture site, immobilize adjacent bone fragments and carry clinical-type forces experienced during daily normal activities. Moreover, this sandwich structure with stronger and stiffer face sheets and more flexible core can result in a higher stiffness and strength in bending compared to tension and compression. These qualities make the proposed hybrid composite an ideal candidate for the design of an optimized fracture fixation system with much closer mechanical properties to human cortical bone.

  14. Tibial Lengthening Using a Fixator-Assisted Lengthening Plate: A New Technique

    PubMed Central

    Tosun, Haci Bayram; Agir, Ismail; Gumustas, Seyitali; Serbest, Sancar; Uludag, Abuzer; Celik, Suat

    2016-01-01

    Background There are many techniques that are used for limb lengthening. Lengthening a limb over a plate is an alternative choice used in children or when using an intramedullary nail is difficult. Objectives In this study, we presented a new technique for tibial lengthening using a monolateral external fixator over a lengthening plate. Materials and Methods For tibial lengthening, a monolateral external fixator was attached to the composite bone model medially. After a corticotomy was performed, the lengthening plate was placed laterally. Three locking screws were inserted proximally, and two cortical screws were inserted into a lengthening hole that was 1 cm below the osteotomy site. We avoided contact between the screws of the lengthening plate and the pins of the external fixator. During bone lengthening with the monolateral external fixator, the screws at the lengthening hole were able to slide distally with the distal segment of the tibia to allow for tibial elongation. Two locking screws were fixed at the distal locking holes of the plate when the bone elongation was complete. The external fixator was then removed. Results The fixator-assisted lengthening plate allowed bone lengthening without malalignment. There were no mechanical problems associated with the external fixator during the lengthening process. Plate osteosynthesis was stable after the fixator was removed. There was no contact between the screws of plate and the Schanz pins of the external fixator under C-arm fluoroscopy. Conclusions The fixator-assisted lengthening plate technique helps to maintain the stability and alignment at both sides of an osteotomy during tibial elongation. It allows the early removal of the external fixator immediately after lengthening is completed. This technique can be applied in children with open physes and in patients with a narrow medullary canal who are unsuitable for limb lengthening over an intramedullary nail. PMID:28184364

  15. Biomechanical Study of the Fixation Strength of Anteromedial Plating for Humeral Shaft Fractures

    PubMed Central

    Zheng, Yin-Feng; Zhou, Jun-Lin; Wang, Xiao-Hong; Shan, Lei; Liu, Yang

    2016-01-01

    Background: Open reduction and internal fixation with plate and screws are the gold standard for the surgical treatment of humeral shaft fractures, this study was to compare the mechanical properties of anteromedial, anterolateral, and posterior plating for humeral shaft fractures. Methods: A distal third humeral shaft fracture model was constructed using fourth-generation sawbones (#3404, composite bone). A total of 24 sawbones with a distal third humeral shaft fracture was randomly divided into three Groups: A, B, and C (n = 8 in each group) for anteromedial, anterolateral, and posterior plating, respectively. All sawbones were subjected to horizontal torsional fatigue tests, horizontal torsional and axial compressive fatigue tests, four-point bending fatigue tests in anteroposterior (AP) and mediolateral (ML) directions and horizontal torsional destructive tests. Results: In the horizontal torsional fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 6.12°, 6.53°, and 6.81°. In horizontal torsional and axial compressive fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 5.66°, 5.67°, and 6.36°. The mean plate displacement amplitude was 0.05 mm, 0.08 mm, and 0.10 mm. Group A was smaller than Group C (P < 0.05). In AP four-point bending fatigue tests, the mean plate displacement amplitude was 0.16 mm, 0.13 mm, and 0.20 mm. Group B was smaller than Group C (P < 0.05). In ML four-point bending fatigue tests, the mean plate displacement amplitude were 0.16 mm, 0.19 mm, and 0.17 mm. In horizontal torsional destructive tests, the mean torsional rigidity in Groups A, B, and C was 0.82, 0.75, and 0.76 N·m/deg. The yielding torsional angle was 24.50°, 25.70°, and 23.86°. The mean yielding torque was 18.46, 18.05, and 16.83 N·m, respectively. Conclusions: Anteromedial plating was superior to anterolateral or posterior plating in all mechanical tests except in AP four-point bending fatigue tests compared to the

  16. Biomechanical Study of the Fixation Strength of Anteromedial Plating for Humeral Shaft Fractures.

    PubMed

    Zheng, Yin-Feng; Zhou, Jun-Lin; Wang, Xiao-Hong; Shan, Lei; Liu, Yang

    2016-08-05

    Open reduction and internal fixation with plate and screws are the gold standard for the surgical treatment of humeral shaft fractures, this study was to compare the mechanical properties of anteromedial, anterolateral, and posterior plating for humeral shaft fractures. A distal third humeral shaft fracture model was constructed using fourth-generation sawbones (#3404, composite bone). A total of 24 sawbones with a distal third humeral shaft fracture was randomly divided into three Groups: A, B, and C (n = 8 in each group) for anteromedial, anterolateral, and posterior plating, respectively. All sawbones were subjected to horizontal torsional fatigue tests, horizontal torsional and axial compressive fatigue tests, four-point bending fatigue tests in anteroposterior (AP) and mediolateral (ML) directions and horizontal torsional destructive tests. In the horizontal torsional fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 6.12°, 6.53°, and 6.81°. In horizontal torsional and axial compressive fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 5.66°, 5.67°, and 6.36°. The mean plate displacement amplitude was 0.05 mm, 0.08 mm, and 0.10 mm. Group A was smaller than Group C (P < 0.05). In AP four-point bending fatigue tests, the mean plate displacement amplitude was 0.16 mm, 0.13 mm, and 0.20 mm. Group B was smaller than Group C (P < 0.05). In ML four-point bending fatigue tests, the mean plate displacement amplitude were 0.16 mm, 0.19 mm, and 0.17 mm. In horizontal torsional destructive tests, the mean torsional rigidity in Groups A, B, and C was 0.82, 0.75, and 0.76 N·m/deg. The yielding torsional angle was 24.50°, 25.70°, and 23.86°. The mean yielding torque was 18.46, 18.05, and 16.83 N·m, respectively. Anteromedial plating was superior to anterolateral or posterior plating in all mechanical tests except in AP four-point bending fatigue tests compared to the anterolateral plating group. We can suggest

  17. Cerclage wire-plate composite for fixation of quadrilateral plate fractures of the acetabulum: a checkrein and pulley technique.

    PubMed

    Farid, Yasser R

    2010-05-01

    Acetabular fractures with complete or incomplete quadrilateral plate separation frequently present with central displacement of the femoral head. Failure of stable fixation of medial wall fractures leaves residual subluxation despite reduction of other fracture components. Several fixation techniques may be either technically demanding or insufficient for stable fixation in conditions of comminution, osteoporosis, or neglected injuries. The proposed wire-plate composite uses a reconstruction spring plate over the pelvic brim for medial wall buttressing. One hole on its true pelvic limb provides a pulley to deviate a cerclage wire or cable passed through the greater sciatic notch into the true pelvis. This enhances buttressing against medial protrusion. Application through anterior approaches is simple and fixation is reliable in difficult fractures without the risk of joint penetration because all quadrilateral plate buttressing implants remain extraosseous.

  18. Complications of appendicular fracture repair in cats and small dogs using locking compression plates.

    PubMed

    Vallefuoco, Rosario; Le Pommellet, Helene; Savin, Audrey; Decambron, Adeline; Manassero, Mathieu; Viateau, Véronique; Gauthier, Olivier; Fayolle, Pascal

    2016-01-01

    Our objectives were: 1) to review the complications associated with stabilization of appendicular fractures in cats and small dogs using locking compression plates (LCP), and 2) to identify factors that could influence fixation construct stability. Retrospective clinical study. Medical and radiographic records of cats and small dogs with appendicular fractures treated with LCP were reviewed. Only cases with adequate follow-up to document clinical union and cases for which complications appeared before the clinical union were included. Complications were classified as implant-related complications or other complications. Cases with implant-related complications were compared to cases with non-implant-related complications for differences in signalment (species, age, body weight, multiple fractures), fracture location and type (fractured bone, fracture localization, closed or open fracture), reduction method (open reduction and internal fixation [ORIF] or minimally invasive plate osteosynthesis [MIPO]) and fixation evaluations (implant size, plate-bridging ratio, plate span ratio, working length, plate screw density, number of screws and cortices engaged per plate and per main fragment, ratio between screw and bone diameter at the narrowest aspect of the bone, and presence of ancillary fixation). Seventy-five fractures from 63 cats (64 fractures) and 10 dogs (11 fractures) met the inclusion criteria. Eight humeral, 13 radio-ulnar, 26 femoral, and 28 tibio-fibular fractures were treated. Primary repair of the fracture was performed using 2.0 mm and 2.4 mm LCP in 22 and 53 fractures, respectively. Overall and implant-related complications were encountered in 13 and seven of 75 fractures, respectively. Fixation failure was not significantly associated with any aforementioned factor considered in this study, and in particular, there was no significant difference in the occurrence of fixation failure between fractures stabilized with two, or more than two, bicortical

  19. Distraction osteogenesis using combined locking plate and Ilizarov fixator in the treatment of bone defect: A report of 2 cases

    PubMed Central

    Mukhopadhaya, John; Raj, Manish

    2017-01-01

    Distraction osteogenesis and bone transport has been used to reconstruct bone loss defect by allowing new bone to form in the gap. Plate-guided bone transport has been successfully described in literature to treat bone loss defect in the femur, tibia, and mandible. This study reports two cases of fracture of femur with segmental bone loss treated with locking plate fixation and bone transport with Ilizarov ring fixator. At the time of docking, when the transport segment is compressed with bone fragment, the bone fragment is fixed with additional locking or nonlocking screws through the plate. The bone defect size was 7 cm in case 1 and 8 cm in case 2 and the external fixation indexes were 12.7 days/cm and 14 days/cm. No shortening was present in either of our cases. The average radiographic consolidation index was 37 days/cm. Both cases achieved infection-free bone segment regeneration and satisfactorily functional outcome. This technique reduces the duration of external fixation during the consolidation phase, allows correction of length and alignment and provides earlier rehabilitation.

  20. Incipient transition phenomena in compressible flows over a flat plate

    NASA Technical Reports Server (NTRS)

    Erlebacher, G.; Hussaini, M. Y.

    1986-01-01

    The full three-dimensional time-dependent compressible Navier-Stokes equations are solved by a Fourier-Chebyshev method to study the stability of compressible flows over a flat plate. After the code is validated in the linear regime, it is applied to study the existence of the secondary instability mechanism in the supersonic regime.

  1. Compressive strength of damaged and repaired composite plates

    NASA Technical Reports Server (NTRS)

    Finn, Scott R.; He, Yi-Fei; Springer, George S.; Lee, Hung-Joo

    1992-01-01

    Tests were performed assessing the effectiveness of repair in restoring the mechanical properties of damaged, solid composite plates made either of Fiberite T300/976 graphite-epoxy, Fiberite IM7/977-2 graphite-toughened epoxy, or ICI APC-2 graphite-PEEK. The plate length, the layup and the amount of damage were also varied. Damage was introduced in the plates either by impacting them with a solid projectile or by applying a transverse static load. Some (75 percent) or all (100 percent) of the damaged zone was then cut out, and the plate was repaired by plugging and patching the hole. The effectiveness of the repair was evaluated by measuring the compressive strengths of undamaged plates, damaged plates with no cutout, damaged plates with a cutout, and repaired plates. The data at an intermediate stage of repair provide information on the effect of each repair step on the compressive strength. The results indicated that for the solid plates used in these tests, the repair methods used herein did not improve the compressive strength of already damaged plates.

  2. Biomechanical evaluation of fracture fixation constructs using a variable-angle locked periprosthetic femur plate system.

    PubMed

    Hoffmann, Martin F; Burgers, Travis A; Mason, James J; Williams, Bart O; Sietsema, Debra L; Jones, Clifford B

    2014-07-01

    In the United States there are more than 230,000 total hip replacements annually, and periprosthetic femoral fractures occur in 0.1-4.5% of those patients. The majority of these fractures occur at the tip of the stem (Vancouver type B1). The purpose of this study was to compare the biomechanically stability and strength of three fixation constructs and identify the most desirable construct. Fifteen medium adult synthetic femurs were implanted with a hip prosthesis and were osteotomized in an oblique plane at the level of the implant tip to simulate a Vancouver type B1 periprosthetic fracture. Fractures were fixed with a non-contact bridging periprosthetic proximal femur plate (Zimmer Inc., Warsaw, IN). Three proximal fixation methods were used: Group 1, bicortical screws; Group 2, unicortical screws and one cerclage cable; and Group 3, three cerclage cables. Distally, all groups had bicortical screws. Biomechanical testing was performed using an axial-torsional testing machine in three different loading modalities (axial compression, lateral bending, and torsional/sagittal bending), next in axial cyclic loading to 10,000 cycles, again in the three loading modalities, and finally to failure in torsional/sagittal bending. Group 1 had significantly greater load to failure and was significantly stiffer in torsional/sagittal bending than Groups 2 and 3. After cyclic loading, Group 2 had significantly greater axial stiffness than Groups 1 and 3. There was no difference between the three groups in lateral bending stiffness. The average energy absorbed during cyclic loading was significantly lower in Group 2 than in Groups 1 and 3. Bicortical screw placement achieved the highest load to failure and the highest torsional/sagittal bending stiffness. Additional unicortical screws improved axial stiffness when using cable fixation. Lateral bending was not influenced by differences in proximal fixation. To treat periprosthetic fractures, bicortical screw placement should be

  3. The apparent width of the plate in compression

    NASA Technical Reports Server (NTRS)

    Marguerre, Karl

    1937-01-01

    The following investigation treats the load capacity of a rectangular plate stressed in compression on one direction (x) beyond the buckling limit. The plate is rotatable (i.e., free from moments) supported at all four sides by bending-resistant beams.

  4. Dynamic Stabilization of Simple Fractures With Active Plates Delivers Stronger Healing Than Conventional Compression Plating

    PubMed Central

    Tsai, Stanley; Bliven, Emily K.; von Rechenberg, Brigitte; Kindt, Philipp; Augat, Peter; Henschel, Julia; Fitzpatrick, Daniel C.; Madey, Steven M.

    2017-01-01

    Objectives: Active plates dynamize a fracture by elastic suspension of screw holes within the plate. We hypothesized that dynamic stabilization with active plates delivers stronger healing relative to standard compression plating. Methods: Twelve sheep were randomized to receive either a standard compression plate (CP) or an active plate (ACTIVE) for stabilization of an anatomically reduced tibial osteotomy. In the CP group, absolute stabilization was pursued by interfragmentary compression with 6 cortical screws. In the ACTIVE group, dynamic stabilization after bony apposition was achieved with 6 elastically suspended locking screws. Fracture healing was analyzed weekly on radiographs. After sacrifice 9 weeks postsurgery, the torsional strength of healed tibiae and contralateral tibiae was measured. Finally, computed tomography was used to assess fracture patterns and healing modes. Results: Healing in both groups included periosteal callus formation. ACTIVE specimens had almost 6 times more callus area by week 9 (P < 0.001) than CP specimens. ACTIVE specimens recovered on average 64% of their native strength by week 9, and were over twice as strong as CP specimens, which recovered 24% of their native strength (P = 0.008). Microcomputed tomography demonstrated that compression plating induced a combination of primary bone healing and gap healing. Active plating consistently stimulated biological bone healing by periosteal callus formation. Conclusions: Compared with compression plating, dynamic stabilization of simple fractures with active plates delivers significantly stronger healing. PMID:27861456

  5. Treatment of Palatal Fractures by Osteosynthesis with 2.0-mm Locking Plates as External Fixator

    PubMed Central

    Cienfuegos, Ricardo; Sierra, Eduardo; Ortiz, Benjamin; Fernández, Gerardo

    2010-01-01

    Treatment options for palatal fractures range from orthodontic braces, acrylic bars, and arch bars for maxillomandibular fixation to internal fixation, with plates and screws placed under the palate mucosa and periosteum, together with pyriform aperture or alveolar plating plus buttress reconstruction. Forty-five patients, ages 4 to 56, were treated using medium- or high-profile locking plates placed over the palatal mucosa as an external fixator for palatal fractures, together with treatment for other associated facial fractures. In open fractures, plates were placed after approximating the edges of the mucosal wounds. Plates and screws for palate fixation were removed at 12 weeks, when computed tomography scans provided evidence of fracture healing. All palatal fractures healed by 12 weeks, with no cases of mucosal necrosis, bone exposure, fistulae, or infections. This approach achieves adequate stability, reduces the risk of bone and mucosal necrosis, and promotes healing of mucosal wounds in case of open fractures. PMID:22132261

  6. Vibration characteristics of rectangular plate in compressible inviscid fluid

    NASA Astrophysics Data System (ADS)

    Liao, Chan-Yi; Ma, Chien-Ching

    2016-02-01

    This paper presents a mathematical derivation of the vibration characteristics of an elastic thin plate placed at the bottom of a three dimensional rectangular container filled with compressible inviscid fluid. A set of beam functions is used as the admissible functions of the plate in a fluid-plate system, and the motion of the fluid induced by the deformation of the plate is obtained from a three-dimensional acoustic equation. Pressure from the fluid over the fluid-plate interface is integrated to form a virtual mass matrix. The frequency equation of the fluid-plate system is derived by combining mass, stiffness, and the virtual mass matrix. Solving the frequency equation makes it possible to obtain the dynamic characteristic of the fluid-plate system, such as resonant frequencies, corresponding mode shapes, and velocity of the fluid. Numerical calculations were performed for plates coupled with fluids with various degrees of compressibility to illustrate the difference between compressible and incompressible fluids in a fluid-plate system. The proposed method could be used to predict resonant frequencies and mode shapes with accuracy compared to that of incompressible fluid theory (IFT). The proposed method can be used to analyze cases involving high value of sound velocity, such as incompressible fluids. When the sound velocity approaches infinity, the results obtained for compressible fluids are similar to those of incompressible fluids. We also examined the influence of fluid compressibility on vibration characteristics in which a decrease in sound velocity was shown to correspond to a decrease in resonant frequency. Additional modes, not observed in incompressible fluids, were obtained in cases of low sound velocity, particularly at higher resonant frequencies. Fluid velocity plots clearly reveal that the additional resonant modes can be attributed to the compressible behavior of the fluid.

  7. Plate fixation of periprosthetic femur fractures: What happens to the cement mantle?

    PubMed

    Konstantinidis, Lukas; Schmidt, Benjamin; Bernstein, Anke; Hirschmüller, Anja; Schröter, Steffen; Südkamp, Norbert Paul; Helwig, Peter

    2017-02-01

    Osteosynthesis of periprosthetic femur fractures by screw fixation around the implanted prosthetic stem is currently regarded as the biomechanically superior option compared with cerclage. The aim of this biomechanical study was damage analysis of the cement mantle after revision screw insertion. A prosthetic stem (Bicontact) was implanted in 20 cadaveric femora in cemented technique. A locking compression plate (Synthes) was then applied to the lateral femur at the level of the prosthetic stem. The method of plate fixation to the femur was assigned randomly to three groups: bicortical non-locking screws, monocortical locking screws, and bicortical locking screws. This was followed by applying a fluctuating axial load (2100 N, 0.5 Hz) for 20,000 cycles. After testing, macroscopic and microscopic evaluations of the cement mantle were conducted. Cracks formed in the cement mantle in 14% of the 80 screw holes. The type of screw (bicortical or monocortical; locking or non-locking) had no significant effect on the number of cracks (p = 0.52). The relationship between manifestation of crack damage and cement mantle thickness was not significant (p = 0.36), whereas the relationship between crack formation and screw position was significant (p = 0.019). Those screws whose circumference was only partially within the cement mantle yielded a significantly lower number of cracks compared with screws positioned completely within the cement mantle or even touching the prosthetic stem. In order to reduce the incidence of crack formation in the cement mantle during plate osteosynthesis of periprosthetic femur fractures, the screws should not be either placed within the cement mantle or make direct contact with the stem.

  8. Design of Fracture Fixation Plate for Necessary and Sufficient Bone Stress Shielding

    NASA Astrophysics Data System (ADS)

    Ramakrishna, Kotlanka; Sridhar, Idapalapati; Sivashanker, Sathiamoorthy; Khong, Kok Sun; Ghista, Dhanjoo N.

    The objective of treating the fractured bone is to achieve painless functioning of the bone and undisturbed healing at the fracture. Internal fixation by stiff bone-plate is one of the standard methods to achieve these objectives. Recently, there is considerable interest in the usage of compliant plates to enhance bone healing with reduced stress shielding. Herein, first an analytical solution is developed to determine screw forces in the bone-plate assembly that conforms the plate and the bone under bending load. Based on the analytical calculations, an optimal fixator plate selection criterion for necessary and sufficient stress shielding is proposed. Second, effectiveness of employing a non-homogeneous stiffness graded (SG) plate rather than a homogeneous stainless steel (SS) plate for stress shielding is investigated using a finite element method. It is found that stress shielding on bone by SG plate is less compared to SS plate.

  9. Current Evidence: Plate Versus Intramedullary Nail for Fixation of Distal Tibia Fractures in 2016.

    PubMed

    Vallier, Heather A

    2016-11-01

    Displaced distal tibia shaft fractures are effectively treated with standard plates and intramedullary nails. Plate fixation performed with meticulous soft tissue handling results in minimal risks of infection and poor wound healing. Standard plates have high rates of primary union, whereas locking plates may delay union because of increased stiffness. Tibial healing may also be delayed after plating of the fibula, although fibula reduction and fixation may aid accuracy of reduction of the tibia. Malalignment occurs more often with infrapatellar intramedullary nailing versus plates, and early results of suprapatellar nailing appear promising in minimizing intraoperative malalignment. Long-term function after fixation of the distal tibia is good for most, with poor outcomes often associated with baseline social and mental health issues.

  10. A biomechanical comparison of one-third tubular plates versus periarticular plates for fixation of osteoporotic distal fibula fractures.

    PubMed

    Davis, Adrian T; Israel, Heidi; Cannada, Lisa K; Bledsoe, J Gary

    2013-09-01

    The purpose of this study was to test the biomechanical properties of locking and nonlocking plates using one-third tubular and periarticular plate designs in an osteoporotic distal fibula fracture model. Twenty-four cadaveric specimens, whose bone mineral densities were obtained using dual x-ray absorptiometry scans, were tested. The fracture model simulated an OTA 44-B2.1 fracture. The constructs included (1) nonlocking one-third tubular plate, (2) locking one-third tubular plate, (3) nonlocking periarticular plate, and (4) locking periarticular plate. The specimens underwent axial loading followed by torsional loading to failure. Statistical analysis was performed using Kruskal-Wallis testing and further analysis with Mann-Whitney testing. The periarticular plates had greater rotational stiffness compared with the one-third tubular plates (P = 0.04). The nonlocking plates had greater torque to failure than the locking plates (P = 0.01). The nonlocking one-third tubular plate had greater torque to failure than the locking one-third tubular plate (P = 0.03). No significant differences were found in any of the comparisons regarding axial stiffness. In biomechanical testing using an osteoporotic model of OTA 44-B2.1 fractures, periarticular plates were superior to one-third tubular plates in rotational stiffness only. Locking plates did not outperform their nonlocking counterparts. Periarticular plates should be considered when treating osteoporotic distal fibula fractures, but one-third tubular plates and nonlocking plates provide adequate fixation for these injuries.

  11. The Role of Minimally Invasive Plate Osteosynthesis in Rib Fixation: A Review

    PubMed Central

    Bemelman, Michael; van Baal, Mark; Yuan, Jian Zhang; Leenen, Luke

    2016-01-01

    More than a century ago, the first scientific report was published about fracture fixation with plates. During the 1950’s, open reduction and plate fixation for fractures were standardized by the founders of Arbeitsgemeinschaft für osteosynthesefragen/Association for the Study of Internal Fixation. Since the introduction of plate fixation for fractures, several plates and screws have been developed, all with their own characteristics. To accomplice more fracture stability, it was thought the bigger the plate, the better. The counter side was a compromised blood supply of the bone, often resulting in bone necrosis and ultimately delayed or non-union. With the search and development of new materials and techniques for fracture fixation, less invasive procedures have become increasingly popular. This resulted in the minimally invasive plate osteosynthesis (MIPO) technique for fracture fixation. With the MIPO technique, procedures could be performed with smaller incisions and thus with less soft tissue damage and a better preserved blood supply. The last 5 years rib fixation has become increasingly popular, rising evidence has become available suggesting that surgical rib fixation improves outcome of patients with a flail chest or isolated rib fractures. Many surgical approaches for rib fixation have been described in the old literature, however, most of these techniques are obscure nowadays. Currently mostly large incisions with considerable surgical insult are used to stabilize rib fractures. We think that MIPO deserves a place in the surgical treatment of rib fractures. We present the aspects of diagnosis, preoperative planning and operative techniques in regard to MIPO rib fixation. PMID:26889439

  12. Are quadrilateral surface buttress plates comparable to traditional forms of transverse acetabular fracture fixation?

    PubMed

    Kistler, Brian J; Smithson, Ian R; Cooper, Seth A; Cox, Jacob L; Nayak, Aniruddh N; Santoni, Brandon G; Sagi, H Claude

    2014-11-01

    Several construct options exist for transverse acetabular fracture fixation. Accepted techniques use a combination of column plates and lag screws. Quadrilateral surface buttress plates have been introduced as potential fixation options, but as a result of their novelty, biomechanical data regarding their stabilizing effects are nonexistent. Therefore, we aimed to determine if this fixation method confers similar stability to traditional forms of fixation. We biomechanically compared two acetabular fixation plates with quadrilateral surface buttressing with traditional forms of fixation using lag screws and column plates. Thirty-five synthetic hemipelves with a transverse transtectal acetabular fracture were allocated to one of five groups: anterior column plate+posterior column lag screw, posterior column plate+anterior column lag screw, anterior and posterior column lag screws only, infrapectineal plate+anterior column plate, and suprapectineal plate alone. Specimens were loaded for 1500 cycles up to 2.5x body weight and stiffness was calculated. Thereafter, constructs were destructively loaded and failure loads were recorded. After 1500 cycles, final stiffness was not different with the numbers available between the infrapectineal (568±43 N/mm) and suprapectineal groups (602±87 N/mm, p=0.988). Both quadrilateral plates were significantly stiffer than the posterior column buttress plate with supplemental lag screw fixation group (311±99 N/mm, p<0.006). No difference in stiffness was identified with the numbers available between the quadrilateral surface plating groups and the lag screw group (423±219 N/mm, p>0.223). The infrapectineal group failed at the highest loads (5.4±0.6 kN) and this was significant relative to the suprapectineal (4.4±0.3 kN; p=0.023), lag screw (2.9±0.8 kN; p<0.001), and anterior buttress plate with posterior column lag screw (4.0±0.6 kN; p=0.001) groups. Quadrilateral surface buttress plates spanning the posterior and anterior

  13. Distal radius fractures: Minimally invasive plate osteosynthesis with dorsal bicolumnar locking plates fixation

    PubMed Central

    Chen, Alvin Chao-Yu; Chou, Ying-Chao; Cheng, Chun-Ying

    2017-01-01

    Background: Controversy still exists regarding the current treatment modalities for unstable distal radius fractures. There are yet few articles investigating the efficacy of bicolumnar dorsal plating technique, which is designed to minimize tissue dissection while providing sufficiently secure fixation. A clinical study was performed to evaluate the feasibility of the minimally invasive plate osteosynthesis (MIPO) technique using a modified dorsal approach for the treatment of distal radius fractures. Materials and Methods: Thirty patients with unilateral distal radius fracture who underwent bicolumnar plate fixation with a minimally invasive dorsal approach between September 2008 and December 2010 were included in this retrospective study. Twenty four patients (8 men and 16 women) with a mean age of 53 years (range 18-85 years) were available for followup of at least 1 year or more were included in final study. Herein, we report the functional radiological outcomes of the study. There were three cases of AO Type A fracture, five cases of AO Type B fracture, and 16 cases of AO Type C fracture. Results: The union was achieved in all the patients. The functional results at one-year followup, assessed using the modified Gartland and Werley scoring system, were excellent in 14 patients, good in seven patients, and fair in three patients. The average correction of deformity was 4.1 mm for radial height, 7.6° for radial inclination, and 20.7° for volar tilt. Conclusions: MIPO with a dorsal approach is a feasible option for the management of displaced distal radius fractures and can result in favorable surgical outcomes. PMID:28216757

  14. Single column locking plate fixation is inadequate in two column acetabular fractures. A biomechanical analysis

    PubMed Central

    2010-01-01

    Background The objective of this study was to determine whether one can achieve stable fixation of a two column (transverse) acetabular fracture by only fixing a single column with a locking plate and unicortical locking screws. We hypothesized that a locking plate applied to the anterior column of a transverse acetabular fracture would create a construct that is more rigid than a non-locking plate, and that this construct would be biomechanically comparable to two column fixation. Methods Using urethane foam models of the pelvis, we simulated transverse acetabular fractures and stabilized them with 1) an anterior column plate with bicortical screws, 2) an anterior locking plate with unicortical screws, 3) an anterior plate and posterior column lag screw, and 4) a posterior plate with an anterior column lag screw. These constructs were mechanically loaded on a servohydraulic material testing machine. Construct stiffness and fracture displacement were measured. Result and Discussion We found that two column fixation is 54% stiffer than a single column fixation with a conventional plate with bicortical screws. There was no significant difference between fixation with an anterior column locking plate with unicortical screws and an anterior plate with posterior column lag screw. We detected a non-significant trend towards more stiffness for the anterior locking plate compared to the anterior non-locking plate. Conclusion In conclusion, a locking plate construct of the anterior column provides less stability than a traditional both column construct with posterior plate and anterior column lag screw. However, the locking construct offers greater strength than a non-locking, bicortical construct, which in addition often requires extensive contouring and its application is oftentimes accompanied by the risk of neurovascular damage. PMID:20459688

  15. Single column locking plate fixation is inadequate in two column acetabular fractures. A biomechanical analysis.

    PubMed

    Khajavi, Kiarash; Lee, Arthur T; Lindsey, Derek P; Leucht, Philipp; Bellino, Michael J; Giori, Nicholas J

    2010-05-09

    The objective of this study was to determine whether one can achieve stable fixation of a two column (transverse) acetabular fracture by only fixing a single column with a locking plate and unicortical locking screws. We hypothesized that a locking plate applied to the anterior column of a transverse acetabular fracture would create a construct that is more rigid than a non-locking plate, and that this construct would be biomechanically comparable to two column fixation. Using urethane foam models of the pelvis, we simulated transverse acetabular fractures and stabilized them with 1) an anterior column plate with bicortical screws, 2) an anterior locking plate with unicortical screws, 3) an anterior plate and posterior column lag screw, and 4) a posterior plate with an anterior column lag screw. These constructs were mechanically loaded on a servohydraulic material testing machine. Construct stiffness and fracture displacement were measured. We found that two column fixation is 54% stiffer than a single column fixation with a conventional plate with bicortical screws. There was no significant difference between fixation with an anterior column locking plate with unicortical screws and an anterior plate with posterior column lag screw. We detected a non-significant trend towards more stiffness for the anterior locking plate compared to the anterior non-locking plate. In conclusion, a locking plate construct of the anterior column provides less stability than a traditional both column construct with posterior plate and anterior column lag screw. However, the locking construct offers greater strength than a non-locking, bicortical construct, which in addition often requires extensive contouring and its application is oftentimes accompanied by the risk of neurovascular damage.

  16. Design and experimental evaluation of adjustable bone plates for mandibular fracture fixation.

    PubMed

    Cervantes, Thomas M; Slocum, Alexander H; Seldin, Edward B

    2012-01-03

    Conventional bone plates are commonly used for surgical mandibular fracture fixation. Improper alignment between bone segments, however, can result in malocclusion. Current methods of fixation require a surgeon to visually align segments of bone and affix a metal plate using bone screws, after which little can be done to adjust alignment. A method of adjusting fracture alignment after plate placement, without screw removal, presents an improvement over costly and risky revision surgery. A modified bone plate has been designed with a deformable section to give surgeons the ability to reduce misalignments at the fracture site. The mechanics of deformation for various adjustment mechanisms was explored analytically, numerically, and experimentally to ensure that the adjustable plate is comparable to conventional bone plates. A static force of 358.8 N is required to deform the adjustable bone plate, compared with predicted values of 351 N using numerical simulation and 362 N using a simple beam theory. Dynamic testing was performed to simulate in vivo loading conditions and evaluate load-capacity in both deformed and un-deformed bone plates. Results indicate that bending stiffness of a rectangular bone plate is 709 N/mm, compared with 174 N/mm for an octagonal plate and 176 N/mm for standard plates. Once deformed, the rectangular and octagonal plates had a stiffness of 323 N/mm and 228 N/mm, respectively. Un-deformed and deformed adjustable bone plates have efficacy in bone segment fixation and healing.

  17. Evaluation of bioresorbable plates in condylar fracture fixation: a case series.

    PubMed

    Singh, V; Kshirsagar, R; Halli, R; Sane, V; Chhabaria, G; Ramanojam, S; Joshi, S; Patankar, A

    2013-12-01

    The objective of this study was to evaluate the efficacy and stability of bioresorbable plates in condylar fractures in adults. Twelve adult patients who had sustained a condylar fracture, either alone or in combination with other mandibular fractures, were clinically and radiologically assessed for the efficacy and stability of bioresorbable plate and screw fixation. Intraoperatively, a total of seven screw breakages were noted. Six cases showed instability of the fractured fragments after fixation with bioresorbable plates and screws; the other six cases showed adequate stability. A single bioresorbable plate does not provide satisfactory stability for condylar fractures. Also, the screw breakages add additional surgical time and cost to the patient.

  18. Linear optical pulse compression based on temporal zone plates.

    PubMed

    Li, Bo; Li, Ming; Lou, Shuqin; Azaña, José

    2013-07-15

    We propose and demonstrate time-domain equivalents of spatial zone plates, namely temporal zone plates, as alternatives to conventional time lenses. Both temporal intensity zone plates, based on intensity-only temporal modulation, and temporal phase zone plates, based on phase-only temporal modulation, are introduced and studied. Temporal zone plates do not exhibit the limiting tradeoff between temporal aperture and frequency bandwidth (temporal resolution) of conventional linear time lenses. As a result, these zone plates can be ideally designed to offer a time-bandwidth product (TBP) as large as desired, practically limited by the achievable temporal modulation bandwidth (limiting the temporal resolution) and the amount of dispersion needed in the target processing systems (limiting the temporal aperture). We numerically and experimentally demonstrate linear optical pulse compression by using temporal zone plates based on linear electro-optic temporal modulation followed by fiber-optics dispersion. In the pulse-compression experiment based on temporal phase zone plates, we achieve a resolution of ~25.5 ps over a temporal aperture of ~5.77 ns, representing an experimental TBP larger than 226 using a phase-modulation amplitude of only ~0.8π rad. We also numerically study the potential of these devices to achieve temporal imaging of optical waveforms and present a comparative analysis on the performance of different temporal intensity and phase zone plates.

  19. Coracoid bone graft osteolysis after Latarjet procedure: A comparison study between two screws standard technique vs mini-plate fixation.

    PubMed

    Giacomo, Giovanni Di; Costantini, Alberto; de Gasperis, Nicola; De Vita, Andrea; Lin, Bernard K H; Francone, Marco; Beccaglia, Mario A Rojas; Mastantuono, Marco

    2013-01-01

    One of the reason for Latarjet procedure failure may be coracoid graft osteolysis. In this study, we aimed to understand if a better compression between the coracoid process and the glenoid, using a mini-plate fixation during the Latarjet procedure, could reduce the amount of coracoid graft osteolysis. A computed tomography scan analysis of 26 prospectively followed-up patients was conducted after modified Latarjet procedure using mini-plate fixation technique to determine both the location and the amount of coracoid graft osteolysis in them. We then compared our current results with results from that of our previous study without using mini-plate fixation to determine if there is any statistical significant difference in terms of corcacoid bone graft osteolysis between the two surgical techniques. The most relevant osteolysis was represented by the superficial part of the proximal coracoid, whereas the deep part of the proximal coracoid graft is least involved in osteolysis and has best bone healing. The current study showed a significant difference only for the deep part of the distal coracoid with our previous study (P < 0.01). To our knowledge, there are no studies in literature that show the causes of coracoid bone graft osteolysis after Latarjet procedure. Our study suggests that there is a significant difference only for the deep part of the distal coracoid in terms of osteolysis. At clinical examination, this difference did not correspond with any clinical findings. Level 4. Prospective case series, Treatment study.

  20. Buckling analysis for axially compressed flat plates, structural sections, and stiffened plates reinforced with laminated composites

    NASA Technical Reports Server (NTRS)

    Viswanathan, A. V.; Soong, T.; Miller, R. E., Jr.

    1971-01-01

    A classical buckling analysis is developed for stiffened, flat plates composed of a series of linked plate and beam elements. Plates are idealized as multilayered orthotropic elements. Structural beads and lips are idealized as beams. The loaded edges of the stiffened plate are simply-supported and the conditions at the unloaded edges can be prescribed arbitrarily. The plate and beam elements are matched along their common junctions for displacement continuity and force equilibrium in an exact manner. Offsets between elements are considered in the analysis. Buckling under uniaxial compressive load for plates, sections, and stiffened plates is investigated. Buckling loads are the lowest of all possible general and local failure modes, and the mode shape is used to determine whether buckling is a local or general instability. Numerical correlations with existing analysis and test data for plates, sections, and stiffened plates including boron-reinforced structures are discussed. In general correlations are reasonably good.

  1. Fixation strength at the interface between Kerboull-type plate and bone cement.

    PubMed

    Kaku, Nobuhiro; Hara, Katsutoshi; Tabata, Tomonori; Tsumura, Hiroshi

    2014-12-01

    To evaluate the fixation strength at the interface between the Kerboull-type plate and bone cement in 6 experimental conditions. Experimental materials comprised a simulated acetabular block, a simulated Kerboulltype plate, a pressuriser cover, a pressuriser arm, and bone cement. The simulated Kerboull-type plate was placed on the simulated acetabular block, with the pressuriser cover. Bone cement was added and the pressuriser arm was inserted. After 6 days of curing, pulling tests were performed to measure the fixation strength at the interface between the plate and the bone cement. Six experimental conditions were evaluated. In condition 1, a 1-mm plate was used with no gap between the plate and the acetabular block. In condition 2, a 2.5-mm plate was used with no gap. In condition 3, a 2.5-mm plate was used with a 2-mm gap. In condition 4, the plate was not used. In condition 5, condition 2 was tested with the model rotated 45º. In condition 6, condition 3 was tested with the model rotated 45º. The maximum fixation strengths in conditions 1, 2, 3, 5, and 6 were 44.4 N, 59.1 N, 122.5 N, 86.9 N, and 185.2 N, respectively. The most important factor affecting the maximum fixation strength was bone cement at the interface between the plate and the acetabular block, followed by 45º rotation during testing, and then thickness of the plate. To enhance fixation of the Kerboull-type plate with cemented acetabular cup, penetration of cement into the outer side of the Kerboull-type plate should be minimised.

  2. Compression buckling response of tailored rectangular composite plates

    NASA Technical Reports Server (NTRS)

    Biggers, Sherrill B.; Srinivasan, Sundar

    1993-01-01

    Buckling resistance is often a controlling criterion in the design of structures composed of plate elements. Design concepts that lead to increased buckling loads (or strains) of these plate elements can directly lower the structural cost and/or weight by a number of means. This study quantifies the improvements that can be achieved in compression buckling loads of rectangular composite plates by using a simple stiffness-tailoring concept. The approach is to position the unidirectional lamina through the thickness and over the planform of the plate so that the buckling load is increased with no loss in in-plane stiffness or increase in weight. Finite element analyses have been used to determine the effects of tailoring on the buckling loads of plates with various boundary conditions, aspect ratios, thicknesses, and membrane stiffnesses. Increases in buckling loads (or strains) of 200 percent or more compared to the uniform plate-buckling loads are shown possible with this tailoring concept.

  3. Femoral locking plate failure salvaged with hexapod circular external fixation: a report of two cases.

    PubMed

    Ferreira, N; Marais, L C

    2016-08-01

    Femoral non-unions are difficult to treat even for the experienced orthopaedic trauma surgeon. If the non-union follows failure of modern stable internal fixation, the complexity of the management is further increased. We report two cases of stiff hypertrophic femoral non-unions after failed locking plate fixation that were successfully treated with a new hexapod circular external fixator. In addition to providing the necessary stability for functional rehabilitation and union, the hexapod circular fixator software allows gradual correction of deformities in order to restore the normal mechanical alignment of the limb.

  4. Biomechanical evaluation of the fixation methods for transcondylar fracture of the humerus:ONI plate versus conventional plates and screws.

    PubMed

    Shimamura, Yasunori; Nishida, Keiichiro; Imatani, Junya; Noda, Tomoyuki; Hashizume, Hiroyuki; Ohtsuka, Aiji; Ozaki, Toshifumi

    2010-04-01

    We biomechanically evaluated the bone fixation rigidity of an ONI plate (Group I) during fixation of experimentally created transcondylar humerus fractures in cadaveric elbows, which are the most frequently observed humeral fractures in the elderly, and compared it with the rigidity achieved by 3 conventional fixation methods:an LCP reconstruction plate 3.5 using a locking mechanism (Group II), a conventional reconstruction plate 3.5 (CRP) with a cannulated cancellous screw (Group III), and a CRP with 2 cannulated cancellous screws (CS) in a crisscross orientation (Group IV). In the axial loading test, the mean failure loads were:Group I, 98.9+/-32.6;Group II, 108.5+/-27.2;Group III, 50.0+/-7.5;and Group IV, 34.5+/-12.2 (N). Group I fixations failed at a significantly higher load than those of Groups III and IV (p<0.05). In the extension loading test, the mean failure loads were:Group I, 34.0+/-12.4;Group II, 51.0+/-14.8;Group III, 19.3+/-6.0;and Group IV, 14.7+/-3.1 (N). Group IV fixations showed a significantly lower failure load than those of Group I (p<0.05). The fixation rigidities against mechanical loading by the ONI plate and LCP plate were comparable. These results suggested that an ONI system might be superior to the CRP and CS method, and comparable to the LCP method in terms of fixation rigidity for distal humerus fractures.

  5. Bone transport with an external fixator and a locking plate for segmental tibial defects.

    PubMed

    Oh, C-W; Apivatthakakul, T; Oh, J-K; Kim, J-W; Lee, H-J; Kyung, H-S; Baek, S-G; Jung, G-H

    2013-12-01

    Although gradual bone transport may permit the restoration of large-diameter bones, complications are common owing to the long duration of external fixation. In order to reduce such complications, a new technique of bone transport involving the use of an external fixator and a locking plate was devised for segmental tibial bone defects. A total of ten patients (nine men, one woman) with a mean age at operation of 40.4 years (16 to 64) underwent distraction osteogenesis with a locking plate to treat previously infected post-traumatic segmental tibial defects. The locking plate was fixed percutaneously to bridge proximal and distal segments, and was followed by external fixation. After docking, percutaneous screws were fixed at the transported segment through plate holes. At the same time, bone grafting was performed at the docking site with the external fixator removed. The mean defect size was 5.9 cm (3.8 to 9.3) and mean external fixation index was 13.4 days/cm (11.8 to 19.5). In all cases, primary union of the docking site and distraction callus was achieved, with an excellent bony result. There was no recurrence of deep infection or osteomyelitis, and with the exception of one patient with a pre-existing peroneal nerve injury, all achieved an excellent or good functional result. With short external fixation times and low complication rates, bone transport with a locking plate could be recommended for patients with segmental tibial defects.

  6. Implant Material, Type of Fixation at the Shaft, and Position of Plate Modify Biomechanics of Distal Femur Plate Osteosynthesis.

    PubMed

    Kandemir, Utku; Augat, Peter; Konowalczyk, Stefanie; Wipf, Felix; von Oldenburg, Geert; Schmidt, Ulf

    2017-08-01

    To investigate whether (1) the type of fixation at the shaft (hybrid vs. locking), (2) the position of the plate (offset vs. contact) and (3) the implant material has a significant effect on (a) construct stiffness and (b) fatigue life in a distal femur extraarticular comminuted fracture model using the same design of distal femur periarticular locking plate. An extraarticular severely comminuted distal femoral fracture pattern (OTA/AO 33-A3) was simulated using artificial bone substitutes. Ten-hole distal lateral femur locking plates were used for fixation per the recommended surgical technique. At the distal metaphyseal fragment, all possible locking screws were placed. For the proximal diaphyseal fragment, different types of screws were used to create 4 different fixation constructs: (1) stainless steel hybrid (SSH), (2) stainless steel locked (SSL), (3) titanium locked (TiL), and (4) stainless steel locked with 5-mm offset at the diaphysis (SSLO). Six specimens of each construct configuration were tested. First, each specimen was nondestructively loaded axially to determine the stiffness. Then, each specimen was cyclically loaded with increasing load levels until failure. Construct Stiffness: The fixation construct with a stainless steel plate and hybrid fixation (SSH) had the highest stiffness followed by the construct with a stainless steel plate and locking screws (SSL) and were not statistically different from each other. Offset placement (SSLO) and using a titanium implant (TiL) significantly reduced construct stiffness. Fatigue Failure: The stainless steel with hybrid fixation group (SSH) withstood the most number of cycles to failure and higher loads, followed by the stainless steel plate and locking screw group (SSL), stainless steel plate with locking screws and offset group (SSLO), and the titanium plate and locking screws group (TiL) consecutively. Offset placement (SSLO) as well as using a titanium implant (TiL) reduced cycles to failure. Using the

  7. CAD-CAM plates versus conventional fixation plates for primary mandibular reconstruction: A biomechanical in vitro analysis.

    PubMed

    Rendenbach, Carsten; Sellenschloh, Kay; Gerbig, Lucca; Morlock, Michael M; Beck-Broichsitter, Benedicta; Smeets, Ralf; Heiland, Max; Huber, Gerd; Hanken, Henning

    2017-09-01

    CAD/CAM reconstruction plates have become a viable option for mandible reconstruction. The aim of this study was to determine whether CAD/CAM plates provide higher fatigue strength compared with conventional fixation systems. 1.0 mm miniplates, 2.0 mm conventional locking plates (DePuy Synthes, Umkirch, Germany), and 2.0 mm CAD/CAM plates (Materialise, Leuven, Belgium/DePuy Synthes) were used to reconstruct a polyurethane mandible model (Synbone, Malans, CH) with cortical and cancellous bone equivalents. Mastication was simulated via cyclic dynamic testing using a universal testing machine (MTS, Bionix, Eden Prairie, MN, USA) until material failure reached a rate of 1 Hz with increasing loads on the left side. No significant difference was found between the groups until a load of 300 N. At higher loads, vertical displacement differed increasingly, with a poorer performance of miniplates (p = 0.04). Plate breakage occurred in miniplates and conventional locking plates. Screw breakage was recorded as the primary failure mechanism in CAD/CAM plates. Stiffness was significantly higher with the CAD/CAM plates (p = 0.04). CAD/CAM plates and reconstruction plates provide higher fatigue strength than miniplates, and stiffness is highest in CAD/CAM systems. All tested fixation methods seem sufficiently stable for mandible reconstruction. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  8. 16. View of riveted gusset plate connection between compression diagonal, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. View of riveted gusset plate connection between compression diagonal, tension diagonal, and lateral brace at center of 4th panel from north end of west truss of north span, looking from the east - Bridge No. 4900, Spanning Root River at Trunk Highway 16, Rushford, Fillmore County, MN

  9. Ultimate Capacity of Uniaxially Compressed Steel Plates Strengthened by CFRP

    NASA Astrophysics Data System (ADS)

    Tao, Xin; Cao, S. Y.

    2017-06-01

    This paper presents experimental studies on the ultimate capacity of steel plates strengthened by Carbon Fiber-reinforced polymer (CFRP). Some 40 plates are tested under uniaxial compression along its longitudinal direction. The effect of CFRP pasting, plate slenderness ratio and the boundary conditions are illustrated on the studies. The study shows that the steel plates strengthened by CFRP exhibited higher capacity in comparison to similar plates without CFRP. It also can be seen that multi-layers CFRP pasting were better than the single layer, pasting multi-direction is better than pasting uni-direction, pasting the transverse layer outside is better than pasting the longitudinal layer outside, and the effect of longitudinal layer was better than the transverse layer.

  10. Minimally invasive bioabsorbable bone plates for rigid internal fixation of mandible fractures.

    PubMed

    Gaball, Curtis; Lovald, Scott; Baack, Bret; Olson, Garth

    2011-01-01

    To optimize design variables of a bioabsorbable bone plate using a finite element model of the mandible and to discover a minimally invasive bioabsorbable bone plate design that can provide the same mechanical stability as a titanium plate. A finite element model of a mandible with a fracture in the body was subjected to bite loads. An analysis was run to determine the principal strain in the fracture callus and von Mises stress in a titanium plate. These values were then set as the limits within which the bioabsorbable bone plate must comply. The model then considered a bone plate made of the polymer poly(L-lactide-co-D,L-lactide) (P[L/DL]LA) 70/30. An optimization routine determined the smallest volume of bioabsorbable bone plate that can perform as well as a titanium bone plate when fixating mandibular fractures. A P(L/DL)LA plate volume of 315 mm(2) with a thickness of 1.5 mm provided as much mechanical stability as a commonly used titanium strut structure of 172 mm(2). The peak plate stress was well below the yield strength of the material. The P(L/DL)LA bioabsorbable bone plate design is as strong as a titanium plate when fixating fractures of the mandible body despite the polymer material having only 6% of the stiffness of the titanium. The P(L/DL)LA plate can be less than half the volume of its strut-style counterpart.

  11. Complications and range of motion following plate fixation of metacarpal and phalangeal fractures.

    PubMed

    Page, S M; Stern, P J

    1998-09-01

    Eighty-two patients with 105 metacarpal and/or phalangeal fractures stabilized with plates were retrospectively reviewed to assess complications and outcomes. Despite stable fixation and early mobilization, major complications were encountered in 36% of fractures, especially with phalangeal and open fractures. Complications included stiffness, nonunion, plate prominence, infection, and tendon rupture. Forty-eight of 63 (76%) metacarpal fractures and 44 of 66 (67%) closed fractures had a final range of motion greater than 220 degrees; however, only 4 of 37 (11%) phalangeal fractures and 8 of 34 (24%) open fractures achieved this outcome. Despite technical advances in plate design and instrumentation, including lower-profile titanium plates, complications occur commonly with metacarpal and phalangeal fractures, leading to a high incidence of unsatisfactory results. We do not condemn plate fixation, and attribute many of our unsatisfactory results to the frequent use of plates in open and phalangeal fractures.

  12. TIBIOTALOCALCANEAL ARTHRODESIS WITH LATERAL COMPRESSION PLATE

    PubMed Central

    Coughlin, Michael J.; Nery, Caio; Baumfeld, Daniel; Jastifer, James

    2015-01-01

    Objective: The objective of this study was to evaluate the short-term clinical and radiographic results from a TTC fusion procedure using a lateral locking plate specifically designed for this purpose. Methods: All the fourteen patients were evaluated using a variety of methods, including a visual analogue scale (VAS), the AOFAS hindfoot score and a subjective satisfaction scale. The average follow-up was 10 months. Results: The average AOFAS score improved from 41 points preoperatively to 63 points postoperatively. The VAS pain score decreased from 7 to 3 points. Four patients reported excellent results, eight good, one fair and one poor. Conclusion: Our study provides support for using a specially designed plate for TTC fusion in hindfoot salvage surgery. RESUMO Objetivo: O propósito deste estudo é avaliar os resultados clínicos e radiológicos a curto prazo do procedimento de fusão tíbio-talo-calcaneana (TTC) com o uso de uma placa lateral bloqueada específicamente concebida para este fim. Métodos: Todos os 14 pacientes foram avaliados usando uma variedade de métodos, incluindo a escala analógico visual da dor (EAV), escore da AOFAS para o retropé e escala subjetiva de satisfação. O acompanhamento médio foi de 10 meses. Resultados: O escore AOFAS médio melhorou de 41 pontos no período pré-operatório para 63 pontos no período pós-operatório. O escore da dor (EAV) caiu de 7 para 3 pontos. Quatro pacientesforam classificados como excelentes resultados, oito bons, um moderado e um ruim. Conclusão: Nosso estudo dá suporte ao uso da placa especialmente desenhada para a fusão tibio-talo-calcaneana (TTC) nas cirurgias de salvamento do retropé. PMID:27047852

  13. 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.

  14. Definitive plates overlapping provisional external fixator pin sites: is the infection risk increased?

    PubMed Central

    Shah, Chirag M.; Babb, Patricia; McAndrew, Christopher M.; Brimmo, Olubusola; Badarudeen, Sameer; Tornetta, Paul; Ricci, William M.; Gardner, Michael J.

    2014-01-01

    Objectives The purpose of this study was to compare the infection risk when internal fixation plates either overlap or did not overlap previous external fixator pin sites in patients with bicondylar tibial plateau fractures and pilon fractures treated with a two-staged protocol of acute spanning external fixation and later definitive internal fixation. Design Retrospective comparison study. Setting Two level I trauma centers. Patients/Participants A total of 85 OTA type 41C bicondylar tibial plateau fractures and 97 OTA type 43C pilon fractures treated between 2005 to 2010. Radiographs were evaluated to determine the positions of definitive plates in relation to external fixator pin sites and patients were grouped into an “overlapping” group and a “non-overlapping” group. Intervention Fifty patients had overlapping pin sites and 132 did not. Main Outcome Measure Presence of a deep wound infection Results Overall, 25 patients developed a deep wound infection. Of the 50 patients in the “overlapping” group, 12 (24%) developed a deep infection, compared to 13 (10%) of the 132 patients in the “non-overlapping” group (p = 0.033). Conclusions Placement of definitive plate fixation overlapping previous external fixator pin sites significantly increases the risk of deep infection in the two-staged treatment of bicondylar tibial plateau and pilon fractures. Surgeons must make a conscious effort to place external fixator pins outside of future definitive fixation sites to reduce the overall incidence of deep wound infections. Additionally, consideration must be given to the relative benefit of a spanning external fixator in light of the potential for infection associated with their use. PMID:24531389

  15. A Novel Computer-Aided Approach for Parametric Investigation of Custom Design of Fracture Fixation Plates

    PubMed Central

    2017-01-01

    The present study proposes an integrated computer-aided approach combining femur surface modeling, fracture evidence recover plate creation, and plate modification in order to conduct a parametric investigation of the design of custom plate for a specific patient. The study allows for improving the design efficiency of specific plates on the patients' femur parameters and the fracture information. Furthermore, the present approach will lead to exploration of plate modification and optimization. The three-dimensional (3D) surface model of a detailed femur and the corresponding fixation plate were represented with high-level feature parameters, and the shape of the specific plate was recursively modified in order to obtain the optimal plate for a specific patient. The proposed approach was tested and verified on a case study, and it could be helpful for orthopedic surgeons to design and modify the plate in order to fit the specific femur anatomy and the fracture information. PMID:28203270

  16. A Novel Computer-Aided Approach for Parametric Investigation of Custom Design of Fracture Fixation Plates.

    PubMed

    Chen, Xiaozhong; He, Kunjin; Chen, Zhengming

    2017-01-01

    The present study proposes an integrated computer-aided approach combining femur surface modeling, fracture evidence recover plate creation, and plate modification in order to conduct a parametric investigation of the design of custom plate for a specific patient. The study allows for improving the design efficiency of specific plates on the patients' femur parameters and the fracture information. Furthermore, the present approach will lead to exploration of plate modification and optimization. The three-dimensional (3D) surface model of a detailed femur and the corresponding fixation plate were represented with high-level feature parameters, and the shape of the specific plate was recursively modified in order to obtain the optimal plate for a specific patient. The proposed approach was tested and verified on a case study, and it could be helpful for orthopedic surgeons to design and modify the plate in order to fit the specific femur anatomy and the fracture information.

  17. Biomechanical optimization of bone plates used in rigid fixation of mandibular symphysis fractures.

    PubMed

    Lovald, Scott; Baack, Bret; Gaball, Curtis; Olson, Garth; Hoard, Anna

    2010-08-01

    To design and optimize a bone plate for fractures of the mandibular symphysis that will provide maximum fracture stability with minimal implanted volume and patient intrusion. The design will be driven by the unique biomechanics specific to this fracture location. A finite element model of a fractured human mandible was created using computed tomography scans. The boundary conditions included simulating molar, canine, and incisal loading. The bone plate design process included a shape optimization routine and design parameter analysis using the model. The optimized bone plate design was finally compared with standard bone plate configurations according to stress and strain measures. Compared with the miniplate combination, the InterFlex III plate, with the same thickness and just 14% more implanted volume, had only 55% of the plate stress and 25% less fracture strain under the strongest loads considered by the model. Compared with the band/fracture plate combination, the InterFlex plate had 88% of the fracture strain and 74% of the plate stress, despite having only 60% of the plate volume. The results have demonstrated that the new optimized plate is a hybrid of fixation hardware with the small profile of the smallest miniplate configuration and the superior fixation strength and safety that exceeds that of the larger fracture plate configuration. Copyright 2010 American Association of Oral and Maxillofacial Surgeons. All rights reserved.

  18. Incidence of Hardware Removal Following Volar Plate Fixation of Distal Radius Fracture.

    PubMed

    Lutsky, Kevin F; Beredjiklian, Pedro K; Hioe, Stephen; Bilello, Justin; Kim, Nayoung; Matzon, Jonas L

    2015-12-01

    To assess the risk of tendon rupture or plate removal after volar plate fixation of distal radius fractures and to determine the incidence of hardware removal. We searched the surgical database of 5 attending hand surgeons at a single institution from 2009 to 2014. All patients who had undergone volar plate fixation were included. Patients were excluded if they underwent an alternate form of fixation, had less than 1 year of follow-up, or could not be reached for follow-up. Postoperative radiographs were examined for Soong grade, plate distance to the critical line, and plate distance to the volar rim. If patients had hardware removed, the reason for plate removal was identified. For all patients who did not have documented hardware removal at our institution, we placed a follow-up call to determine whether they had hardware removed elsewhere. A total of 517 patients underwent volar plate fixation, 143 of whom did not have their hardware removed at our institution but could not be reached for follow-up. Of the remaining 374 patients, 37 (10%) had hardware removed. For group 1 (hardware retained), Soong grades were 13% grade 0, 85% grade 1, and 2% grade 2. For group 2 (hardware removed) the proportions were 11%, 76%, and 5%, respectively, and 8% undetermined. Mean plate distance to the critical line was significantly greater for group 2 (1.9 mm) compared with group 1 (1.2 mm). Mean plate distance to the volar rim did not differ (5.1 mm vs 5.3 mm). The incidence of hardware removal in our series was 10%. The vast majority of patients had Soong grade 1 prominence. Patients who had hardware removed had a greater plate prominence volar to the critical line. Plate distance to the volar rim was not associated with removal. Prognostic II. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  19. Odontoid plate fixation without C1-C2 arthrodesis: biomechanical testing of a novel surgical technique and comparison to the conventional screw fixation procedure.

    PubMed

    Platzer, Patrick; Eipeldauer, Stefan; Vécsei, Vilmos

    2010-08-01

    Odontoid plate fixation without C1-C2 arthrodesis appears to be a practicable option for the management of odontoid fractures that are not amenable for conventional screw fixation. The purpose of this study was to measure the mechanical stability of odontoid plate fixation using a specially designed plate construct, and to compare the results to those after conventional screw fixation. The second cervical vertebra was removed from twenty fresh human spinal columns. Stiffness and failure load of the intact odontoid were measured, and type II odontoid fractures were created. Afterward, the specimens were randomly assigned to one of the following four groups: Group I: plate-fixation; Group II: 2-AO-screw-fixation; Group III: 1-AO-screw-fixation; Group IV: Herbert-screw-fixation. In a second series, stiffness and failure load of the stabilized odontoid fractures were assessed for comparison and statistical analysis. Group I showed a significantly higher mean failure load than the other groups. The mean failure load of Group I after fixation of the odontoid fracture was 86% of the mean failure load of the intact odontoid. Comparing Groups II, III and IV, there was no significant difference regarding the failure load. In these three groups the mean failure load after odontoid fixation was approximately 50% of the mean failure load of the intact odontoid. Odontoid plate fixation as an alternative procedure in certain fracture patterns provided a significantly higher biomechanical stability than the technique of odontoid screw fixation. Using a specially designed plate construct, 86% of the original stability of the intact odontoid was restored. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  20. Comparison of complication rates of intramedullary pin fixation versus plating of midshaft clavicle fractures in an active duty military population.

    PubMed

    Wenninger, Jerome J; Dannenbaum, Joseph H; Branstetter, Joanna G; Arrington, Edward D

    2013-01-01

    Military service members have increased requirements of shoulder weight bearing to perform duties. Operative intervention has increased for treatment of displaced middle one-third clavicle fractures. Complications of operatively treated clavicle fixation have not been extensively studied. A retrospective, longitudinal cohort chart evaluation was conducted of all active duty members undergoing fixation of middle one-third clavicle fractures, for complications between intramedullary pin fixation and plate constructs. This review found 62 patients meeting inclusion criteria. Thirty-three patients underwent intramedullary pin fixation with Hagie pins and 31 patients underwent precontoured superior clavicle plate fixation of their middle one-third clavicle fractures. Complications included wound infection, skin and/or soft tissue irritation, and need for unplanned hardware removal. The overall complication rate was 31% in the plate fixation group versus 9% in the intramedullary pin group (p = .024). All patients achieved fracture union with return to duty; however, increased overall complications were seen in the plate fixation group.

  1. Improved compression buckling for rectangular composite plates by stiffness tailoring

    NASA Technical Reports Server (NTRS)

    Biggers, Sherrill B.; Srinivasan, Sundar

    1991-01-01

    Buckling resistance is often a controlling criterion in the design of structural elements. Design concepts that lead to increased buckling loads (or strains) can directly lower the structural cost and/or weight by a number of means. This study quantifies the improvements that can be achieved in compression buckling loads of rectangular composite plates by using a simple stiffness tailoring concept. The approach is to position the unidirectional lamina through the thickness and over the planform of the plate so that the buckling load is increased with no loss in in-plane stiffness or increase in weight. Finite element analyses have been used to determine the effects of tailoring on the buckling load of plates with various boundary conditions, aspect ratios, thicknesses, and membrane stiffnesses. Increases in buckling loads (or strains) of nearly 200 percent over the uniform plate buckling loads are shown possible with this tailoring concept.

  2. Percutaneous K-wire fixation versus palmar plating with locking screws for Colles' fractures.

    PubMed

    Hollevoet, Nadine; Vanhoutie, Tom; Vanhove, Wim; Verdonk, René

    2011-04-01

    Different methods exist to treat distal radius fractures. A prospective randomized study was conducted to establish whether palmar plate fixation with locking screws gave better results than percutaneous K-wire fixation in patients over 50 years of age. Only fractures with dorsal displacement after a simple fall were included in the study. Twenty wrists were treated with K-wires and 20 with a plate. Radiological parameters were measured on preoperative radiographs and at five weeks postoperatively. Clinical results and DASH scores were determined at three months postoperatively and at more than one year. No significant difference in radial inclination, palmar tilt, clinical outcome and DASH score was found between plating and K-wires, but the mean difference in ulnar variance between pre- and postoperative radiographs was significantly better with plates. It can be concluded that plates were superior to K-wires in restoring ulnar variance, but functional outcome was similar with both techniques.

  3. Biomechanical comparison of bicortical locking versus unicortical far-cortex-abutting locking screw-plate fixation for comminuted radial shaft fractures.

    PubMed

    Overturf, Steven J; Morris, Randal P; Gugala, Zbigniew; Lindsey, Ronald W

    2014-10-01

    To provide comparative biomechanical evaluation of bicortical locking versus unicortical-abutting locking screw-plate fixation in a comminuted radius fracture model. A validated synthetic substitute of the adult human radius with a 1.5-cm-long segmental mid-diaphyseal defect was used in the study to simulate a comminuted fracture. Stabilization was achieved with an 8-hole locking plate and either bicortical screws or unicortical-abutting screws. The specimens were tested using nondestructive cyclical loading in 4-point bending, axial compression, and torsion to determine stiffness and displacement and subsequently in 4-point bending to assess load to failure. There were no statistically significant differences between bicortical versus unicortical-abutting locking screw fixation in nondestructive 4-point bending, axial compression, and torsion. Both locking screw constructs also demonstrated comparable 4-point bending loads to failure. The biomechanical equivalence between bicortical locking versus unicortical-abutting locking screw-plate fixation suggests that adequate locking plate fixation can be achieved without perforation of the far cortex. The abutment of the screw tip within the far cortex enhances the unicortical screw positional stability and thereby effectively opposes the displacement of the screw when subjected to bending or axial or rotational loads. Unicortical-abutting screws potentially offer several clinical advantages. They eliminate the need for drilling through the far cortex and thereby a risk of adjacent neurovascular injury or soft tissue structure compromise. They eliminate the issues associated with symptomatic screw prominence. They can decrease risk of refracture after screw-plate removal. In case of revision plating, they permit conversion to bicortical locking screws through the same near-cortex screw holes, which eliminates the need for a longer or repositioned plate. Copyright © 2014 American Society for Surgery of the Hand

  4. Multiplanar Fixation for Patella Fractures Using a Low-Profile Mesh Plate.

    PubMed

    Lorich, Dean G; Warner, Stephen J; Schottel, Patrick C; Shaffer, Andre D; Lazaro, Lionel E; Helfet, David L

    2015-12-01

    Patella fractures are challenging orthopaedic injuries. Many commonly used fixation techniques can be ineffective and lead to poor clinical outcomes even with satisfactory reductions and fracture healing. In this investigation, we present the technique of cage plate fixation of patella fractures and the clinical outcomes of 9 initial patients surgically treated at our institution. This technique allows direct visualization of the articular reduction, provides multiplanar fixation, effectively stabilizes inferior pole comminution, and reduces the risk of patella vascular disruption. Using this technique, we have achieved excellent functional and radiographic outcomes.

  5. Slender Compressed Plate in Component Based Finite Element Model

    NASA Astrophysics Data System (ADS)

    Kurejková, M.; Wald, F.; Kabeláč, J.; Šabatka, L.

    2015-11-01

    The paper presents an advance design model of a slender plate in the structural steel joint. Finite element methods and material models are described and design procedure for slender plates in numerical models of steel joints is proposed. The design procedure is demonstrated on examples. The results are verified with an analytical model according to European standards. A compressed beam with slender web and beam-to-column joint are studied by numerical analysis, buckling resistances are determined and results verified. The verification shows very good agreement.

  6. Radiographic Comparison of Four Anterior Fusion Methods in Two Level Cervical Disc Diseases : Autograft Plate Fixation versus Cage Plate Fixation versus Stand-Alone Cage Fusion versus Corpectomy and Plate Fixation

    PubMed Central

    Kim, Min-Ki; Jeon, Kwang-Mo; Kim, Tae-Sung

    2012-01-01

    Objective To evaluate radiographic results of anterior fusion methods in two-level cervical disc disease : tricortical autograft and plate fixation (ACDF-AP), cage and plate fixation (ACDF-CP), stand-alone cage (ACDF-CA), and corpectomy and plate fixation (ACCF). Methods The numbers of patients were 70 with a minimum 6 month follow-up (ACDF-AP : 12, ACDF-CP : 27, ACDF-CA : 15, and ACCF : 16). Dynamic simple X-ray and computed tomography were evaluated preoperatively, postoperatively, 6 month, and at the final follow-up. The fusion and subsidence rates at the final were determined, and global cervical lordosis (GCL), cervical range of motion, fused segment angle (FSA), and fused segment height (FSH) were analyzed. Results Nonunion was observed in 4 (25%) patients with ACDF-CA, 1 (8%) patient with ACDF-AP, 1 (4%) patient with ACDF-CP. The number of loss of FSH (%) more than 3 mm were 2 patients (16%) in ACDF-AP, 3 patients (11%) in ACDF-CP, 5 patients (33%) in ACDF-CA, and 3 patients (20%) in ACCF. The GCL was decreased with ACDF-CA and increased with others. The FSA was increased with ACDF-AP, ACDF-CP, and ACCF, but ACDF-CA was decreased. At the final follow-up, the FSH was slightly decreased in ACDF-CP, ACDF-AP, and ACCF, but ACDF-CA was more decreased. Graft related complication were minimal. Screw loosening, plate fracture, cage subsidence and migration were not identified. Conclusion ACDF-CP demonstrated a higher fusion rate and less minimal FSH loss than the other fusions in two-level cervical disc disease. The ACDF-AP and ACCF methods had a better outcome than the ACDF-CA with respect to GCL, FSA, and FSH. PMID:22639708

  7. Biomechanical Comparison of Volar Fixed-Angle Locking Plates for AO C3 Distal Radius Fractures: Titanium Versus Stainless Steel With Compression.

    PubMed

    Marshall, Tyler; Momaya, Amit; Eberhardt, Alan; Chaudhari, Nilesh; Hunt, Thomas R

    2015-10-01

    To determine biomechanical differences between a fixed-angle locking volar titanium plate (VariAx; Stryker, Kalamazoo, MI) and a fixed-angle compression locking volar stainless steel plate (CoverLoc Volar Plate; Tornier, Amsterdam, Netherlands) in the fixation of simulated AO C3 distal radius fractures. Eighteen cadaveric upper extremities (9 matched pairs) with an average age of 54 years were tested. A 4-part AO C3 fracture pattern was created in each specimen. The fractures were reduced under direct vision and fixed with either the fixed-angle locking volar titanium plate or the fixed-angle compression locking volar stainless steel plate. Motion tracking analysis was then performed while the specimens underwent cyclic loading. Changes in displacement, rotation, load to failure, and mode of failure were recorded. The fragments, when secured with the fixed-angle compression locking stainless steel construct, demonstrated less displacement and rotation than the fragments secured with the fixed-angle locking titanium plate under physiological loading conditions. In the fixed-angle compression locking stainless steel group, aggregate displacement and rotation of fracture fragments were 5 mm and 3° less, respectively, than those for the fixed-angle locking titanium group. The differences between axial loads at mechanical failure and stiffness were not statistically significant. The compression locking stainless steel group showed no trend in mode of failure, and the locking titanium plate group failed most often by articular fixation failure (5 of 9 specimens). The fixed-angle compression locking stainless steel volar plate may result in less displacement and rotation of fracture fragments in the fixation of AO C3 distal radius fractures than fixation by the fixed-angle locking volar titanium plate. However, there were no differences between the plates in mechanical load to failure and stiffness. Fixation of distal radius AO C3 fracture patterns with the fixed

  8. Volar plate position and flexor tendon rupture following distal radius fracture fixation.

    PubMed

    Kitay, Alison; Swanstrom, Morgan; Schreiber, Joseph J; Carlson, Michelle G; Nguyen, Joseph T; Weiland, Andrew J; Daluiski, Aaron

    2013-06-01

    To determine whether there were differences between plate position in patients who had postoperative flexor tendon ruptures following volar plate fixation of distal radius fractures and those who did not. Three blinded reviewers measured the volar plate prominence and position on the lateral radiographs of 8 patients treated for flexor tendon ruptures and 17 matched control patients without ruptures following distal radius fracture fixation. We graded plate prominence using the Soong grading system, and we measured the distances between the plate and both the volar critical line and the volar rim of the distal radius. A higher Soong grade was associated with flexor tendon rupture. Patients with ruptures had plates that were more prominent volarly and more distal than matched controls without ruptures. Plate prominence projecting greater than 2.0 mm volar to the critical line had a sensitivity of 0.88, a specificity of 0.82, and positive and negative predictive values of 0.70 and 0.93, respectively, for tendon ruptures. Plate position distal to 3.0 mm from the volar rim had a sensitivity of 0.88, a specificity of 0.94, and positive and negative predictive values of 0.88 and 0.94, respectively, for tendon ruptures. We identified plate positions associated with attritional flexor tendon rupture following distal radius fracture fixation with volar plates. To decrease rupture risk, we recommend considering elective hardware removal after union in symptomatic patients with plate prominence greater than 2.0 mm volar to the critical line or plate position within 3.0 mm of the volar rim. Therapeutic III. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  9. Stress-riser fractures of the hip after sliding screw plate fixation.

    PubMed

    DiMaio, F R; Haher, T R; Splain, S H; Mani, V J

    1992-10-01

    Fractures occurring after fixation of intertrochanteric femur fractures have been described previously in the literature. Terms such as "stress-riser fracture" and "Young's modulus fracture" have been applied. The prevalence of these fracture types has increased, and so has use of the sliding screw plate device for fixation of intertrochanteric hip fractures. The object of this paper is to describe, by case examples, types of stress-related fractures of the proximal femur in association with the sliding screw plate and to define each biomechanical type in review.

  10. Callus Formation and Mineralization after Fracture with Different Fixation Techniques: Minimally Invasive Plate Osteosynthesis versus Open Reduction Internal Fixation

    PubMed Central

    Ding, Haoliang; Qin, Hui; An, Zhiquan

    2015-01-01

    Minimally invasive plate osteosynthesis(MIPO) has been considered as an alternative for fracture treatment. Previous study has demonstrated that MIPO technique has the advantage of less soft tissue injury compared with open reduction internal fixation (ORIF). However, the comparison of callus formation and mineralization between two plate osteosynthesis methods remains unknown. In this experiment, ulna fracture model was established in 42 beagle dogs. The fractures underwent reduction and internal fixation with MIPO or ORIF. Sequential fluorescent labeling and radiographs were applied to determine new callus formation and mineralization in two groups after operation. At 4, 8 and 12 weeks postoperatively, the animals were selected to be sacrificed and the ulna specimens were analyzed by Micro-CT. The sections were also treated with Masson staining for histological evaluation. More callus formation was observed in MIPO group in early stage of fracture healing. The fracture union rate has no significant difference between two groups. The results indicate that excessive soft tissue stripping may impact early callus formation. As MIPO technique can effectively reduce soft tissue injury with little incision, it is considered to be a promising alternative for fracture fixation. PMID:26444295

  11. Fixator-assisted tibial lengthening over a plate in a patient with sequelae of poliomyelitis.

    PubMed

    Tosun, Haci Bayram; Serbest, Sancar; Uludag, Abuzer; Gumustas, Seyitali; Celik, Suat

    2016-11-01

    There are many techniques for limb lengthening. Lengthening over a plate is an alternative choice of fixation in children or when nailing is difficult. We present a new technique for tibial lengthening with using a monolateral external fixator over a lengthening plate.Lengthening over an intramedullary nail is a commonly used method in patients with short stature or limb-length discrepancy. However, in patients with a narrow and excessively sclerotic intramedullary cavity in the pediatric age group where the skeletal system has not yet fully developed, difficulties have been observed in lengthening methods with nailing.Therefore, in these cases, the use of lengthening techniques over a plate is an alternative treatment option. Nevertheless, in lengthening techniques over a plate, if one side of the osteotomy area cannot be fixed, associated mechanical axis problems have been reported.We applied tibia lengthening with external fixator assistance over a custom-made lengthening plate in a patient with sequelae of poliomyelitis. This new lengthening technique applied over a plate could be the solution to the problems observed in other lengthening techniques over a plate.

  12. Does lengthening and then plating (LAP) shorten duration of external fixation?

    PubMed

    Harbacheuski, Ryhor; Fragomen, Austin T; Rozbruch, S Robert

    2012-06-01

    Classic bone lengthening requires patients wear external fixation for the distraction and consolidation phases and there is fracture risk after frame removal. Our technique of lengthening with the Taylor Spatial Frame(TM) and then insertion of a locked plate allows earlier removal of the external fixator during consolidation. Plate insertion is accomplished through a clean pin-free zone avoiding contamination and before frame removal maintaining bone position. We asked (1) whether lengthening and then plating (LAP) decrease the time for external fixation (2) how alignment and complications compare with those of the classic method. We performed a retrospective case-matched comparison between LAP and the classic technique with 27 extremities in each group. We compared time wearing the frame, bone healing index, external fixation index, joint ROM, alignment, and complications. The time wearing the frame and external fixation index were lower in the LAP group (4.5 versus 6.2 months and 1.5 versus 2 months/cm). Deviation from normal alignment was observed in seven and six patients in the LAP and classic group, respectively. Varus malalignment in two patients in the LAP group was associated with plate breakage. The incidence of pin-tract infection was greater in the classic group (12 versus two). No deep infections occurred in the LAP group. The LAP technique shortened the time patients wore the external fixator but was associated with a high incidence of varus deformity. Stronger plates may help prevent deformity and allow earlier removal of the frame. Level III, therapeutic study (retrospective study). See the Guidelines for Authors for a complete description of levels of evidence.

  13. Prognostic Factors for Reoperation After Plate Fixation of the Midshaft Clavicle.

    PubMed

    Schemitsch, Laura A; Schemitsch, Emil H; Kuzyk, Paul; McKee, Michael D

    2015-12-01

    To determine which prognostic factors were associated with an increased risk for all-cause reoperation in a heterogeneous population of patients treated with primary plate fixation of a midshaft clavicular fracture. Retrospective observational study. Single university-affiliated tertiary care Level 1 trauma center. Of 235 consecutive patients with primary plate fixation for a midshaft clavicular fracture. A reviewer extracted data through a retrospective chart review regarding 20 possible prognostic variables and documented reoperations (defined as any surgical procedure after the initial surgery, including implant removal, bone grafts, implant exchanges, or debridement for infection). Open reduction and internal fixation of the clavicle using straight and precontoured clavicle plates. Complete 2-year follow-up information was available for 153 of 235 patients (65%). Of these 153 patients included in the analysis, 58 (38%) had reoperations. The preoperative risk factors for 3 specific "reoperation outcomes" were examined: (1) reoperation for implant removal alone; (2) reoperation for nonunion, infection, or fixation failure; and (3) multiple reoperations. There was a significant reoperation rate in this patient series (58 of 153 patients, 38%). Although most were for isolated plate removal (42 of 153 patients, 27%), there were a minority of patients who required more complex (16 of 153 patients, 10%) or multiple (8 of 153 patients, 5%) procedures. For these 3 possible outcomes (reoperation for implant removal alone, reoperation for nonunion, infection, or fixation failure, and the need for multiple reoperations), significant risk factors were identified that can assist surgeons in patient selection and predicting reoperation after plate fixation of midshaft clavicle fractures. The significant risk factors for implant removal alone (42 of 153, 27%) were the use of a plate that was not precontoured and patient height <175 cm. The significant risk factors for

  14. Open reduction internal fixation for midline mandibulotomy: lag screws vs plates.

    PubMed

    Danan, Deepa; Mukherjee, Sugoto; Jameson, Mark J; Shonka, David C

    2014-12-01

    Midline mandibulotomy is a common approach for resection of head and neck oral cavity and oropharyngeal tumors; however, there are limited data available on the outcomes of lag screw vs plate fixation. To compare outcomes for midline mandibulotomy open reduction and internal fixation using plates vs lag screw technique. Retrospective cohort study at a tertiary care academic medical center of patients undergoing midline mandibulotomy for head and neck tumor resection over a 6-year period. Mandibular fixation using lag screws or plates. The medical records and computed tomographic (CT) scans of patients undergoing midline mandibulotomy for head and neck tumor resection over a 6-year period were retrospectively reviewed. The postoperative CT scans were reviewed by a neuroradiologist who graded the fusion site on a scale of 0 to 2 using a 2-pass method. The rates and grades of union were compared, as well as several factors that affect healing, for fixations performed with plates vs lag screws. Thirty-seven patients were included. The overall rate of radiologic union was 90% (9 out of 10) for lag screw technique and 41% (11 out of 27) for plates (P = .01). The average grade of radiologic union was 1.3 for lag screws and 0.67 for plates (P = .04). Hardware exposure occurred in 4 (15%) of the plate group and fistulae formed in 3 (11%); neither complication occurred in the lag screw group. In univariate analysis, both presence of dentition (odds ratio [OR], 5.50 [95% CI, 1.33-22.73]; P = .02) and plate technique (OR, 13.09 [95% CI, 1.45-11.62]; P = .02) were significantly associated with nonunion. In multivariate analysis, plate technique had an OR of 8.32 (95% CI, 0.85-81.75) for nonunion (P = .07). Fixation of midline mandibulotomy with lag screws results in a significantly increased rate of radiologic union compared with plates. Lag screws were also significantly better at achieving radiologic union in patients who underwent postoperative radiation

  15. Coracoid bone graft osteolysis after Latarjet procedure: A comparison study between two screws standard technique vs mini-plate fixation

    PubMed Central

    Giacomo, Giovanni Di; Costantini, Alberto; de Gasperis, Nicola; De Vita, Andrea; Lin, Bernard K. H.; Francone, Marco; Beccaglia, Mario A. Rojas; Mastantuono, Marco

    2013-01-01

    Aims: One of the reason for Latarjet procedure failure may be coracoid graft osteolysis. In this study, we aimed to understand if a better compression between the coracoid process and the glenoid, using a mini-plate fixation during the Latarjet procedure, could reduce the amount of coracoid graft osteolysis. Materials and Methods: A computed tomography scan analysis of 26 prospectively followed-up patients was conducted after modified Latarjet procedure using mini-plate fixation technique to determine both the location and the amount of coracoid graft osteolysis in them. We then compared our current results with results from that of our previous study without using mini-plate fixation to determine if there is any statistical significant difference in terms of corcacoid bone graft osteolysis between the two surgical techniques. Results: The most relevant osteolysis was represented by the superficial part of the proximal coracoid, whereas the deep part of the proximal coracoid graft is least involved in osteolysis and has best bone healing. The current study showed a significant difference only for the deep part of the distal coracoid with our previous study (P < 0.01). Discussion: To our knowledge, there are no studies in literature that show the causes of coracoid bone graft osteolysis after Latarjet procedure. Conclusion: Our study suggests that there is a significant difference only for the deep part of the distal coracoid in terms of osteolysis. At clinical examination, this difference did not correspond with any clinical findings. Level of Evidence: Level 4. Clinical Relevance: Prospective case series, Treatment study. PMID:23858288

  16. Analysis of gene expression profiles in healing rat fractures treated with nail and plate fixation.

    PubMed

    Wang, S D; Li, X L; Liu, H P

    2014-10-20

    To compare fracture healing therapies, the gene expression profiles of rat fracture samples treated with nail and plate fixation were analyzed at 1 day, 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks after surgery. The gene expression profiles GSE1685, which include 19 samples, were downloaded from the Gene Expression Omnibus database. After preprocessing, the gene expression profiles were subjected to time series analysis using the Short Time-series Expression Miner software, and the significantly differentially expressed gene (DEG) sets were selected. Further, the distributions of those DEG sets on the corresponding chromosomes were identified using the functional classification tool. Finally, the DEGs were subjected to function and pathway enrichment analysis. DEG analysis indicated that the number of DEGs (854 genes) from nail fixation was significantly lower than that of DEGs (1029 genes) from plate fixation. The DEGs were mainly enriched in cell proliferation, cellular localization, and response to wounding functions. Several critical DEGs expressed during the fracture healing process were screened, and 2 common pathways were enriched for the DEGs in the nail fixation and plate fixation. These DEGs and pathways may be potential targets or predictive markers during fracture healing.

  17. The effects of physiologic dynamic compression on bone healing under external fixation

    SciTech Connect

    Aro, H.T.; Kelly, P.J.; Lewallen, D.G.; Chao, E.Y. )

    1990-07-01

    The effects of early physiologic dynamic compression on fracture healing were studied in the dog. Transverse midtibial osteotomies were performed bilaterally and stabilized with a relatively rigid external fixation system in a neutralization mode (800 microns) to prevent compression of the osteotomy ends during weight bearing. On the 15th day, one osteotomy in each animal was subjected to dynamic compression through weight bearing by release of the fixator-telescoping mechanism (axial dynamization), while the other side remained unchanged as the control. Analysis of sequential roentgenograms showed that the callus distribution was more symmetric on the dynamic compression side. The two sides showed no significant differences in quantitative technetium-99 bone scans or in osteotomy-site blood flow. There were no statistical differences in new bone formation, bone porosity, or maximum torque between sides. The fixation had maintained the initially created osteotomy gap on the control side and tended to unite through a gap-healing mechanism. The dynamic compression side showed reduction in gap size and union by more of a contact-healing mechanism. There were no statistical differences in the rate of pin loosening, but its distribution according to pin location was significantly different between the two sides.

  18. The mechanical behavior of locking compression plates compared with dynamic compression plates in a cadaver radius model.

    PubMed

    Gardner, Michael J; Brophy, Robert H; Campbell, Deirdre; Mahajan, Amit; Wright, Timothy M; Helfet, David L; Lorich, Dean G

    2005-10-01

    The purpose of this cadaveric study was to compare the mechanical behavior of a locked compression plate, which uses threaded screw heads to create a fixed angle construct, with a dynamic compression plate construct in a cadaver radius model. Mechanical study with cyclic testing and high-speed optical motion analysis. Biomechanics laboratory at an academic institution. Eighteen pairs of fresh-frozen human cadaver radii were divided into 3 groups of 6 to be tested as a group in each of the following force applications: anteroposterior (AP) bending, mediolateral bending, or torsion. Each bone was osteotomized leaving a 5-mm fracture gap and then fixed with a plate. For each pair, 1 radius received a standard plate (limited-contact dynamic compression plates; LC-DCP), the contralateral radius was fixed with a locking compression plate (LCP), and specimens underwent cyclic loading. Normalized stiffness, average energy absorbed, and Newton-cycles to failure were calculated. In addition, a 3-dimensional, high-speed, infrared motion analysis system was used to evaluate motion at the fracture site. Construct stiffness, fracture site motion, cycles to failure, and energy absorption. Repeated measures ANOVA were used to detect differences between groups with time. In the torsion group, LCP specimens failed at 60% greater Newton-cycles than the LC-DCP (1473 vs. 918; P < 0.05). In the AP group, the LC-DCP absorbed significantly greater energy during 10,000 cycles compared with the LCP group (P < 0.05). The 2 constructs demonstrated different biomechanical behavior with time. As cycling progressed in the LC-DCP specimens under torsion testing, stiffness (measured at the actuator at the bone ends) did not change significantly; however, fracture motion (measured at the fracture surfaces) decreased significantly (P = 0.04). The LCP specimens did not display similar behavior. Our findings indicated that LCP constructs may demonstrate subtle mechanical superiority compared with the

  19. Outcomes After Distal Radius Fracture Treatment With Percutaneous Wire Versus Plate Fixation: Meta-Analysis of Randomized Controlled Trials.

    PubMed

    Anderson, Mark S; Ghamsary, Mark; Guillen, Phillip T; Wongworawat, Montri D

    Multiple methods for surgical fixation of distal radius fractures exist, including percutaneous pinning with Kirschner wires and open reduction volar plating. Despite increased costs, the hypothesis of this study was that open reduction and volar plating does not provide improved outcomes over wire fixation. Following Transparent Reporting of Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a meta-analysis of randomized controlled trials was conducted comparing these two methods with regard to clinical outcomes, radiographic parameters, and complications. Seven trials with a total of 858 patients were included. Plating was not favored over pinning with regard to clinical outcomes and radiographic parameters. Pinning was associated with a higher superficial infection risk compared with plating, though the risk of repeat surgery was not different. It was concluded that Kirschner wire fixation, which may be associated with lower costs, is associated with similar clinical and radiographic outcomes when compared with volar plate fixation, although wire fixation is associated with higher superficial infection risk.

  20. Fixation of compressive deformation in wood by pre-steaming

    Treesearch

    M. Inoue; N. Sekino; T. Morooka; R.M. Rowell; M. Norimoto

    2008-01-01

    Wood block specimens pre-steamed at 120-220 °C for 5-20 min were compressed in the radial direction. The recovery of set decreased with increasing pre-steaming temperature and time. The reduction of set recovery correlated with the amount of weight loss in steaming irrespective of pre-steaming temperature and time. The weight loss for the highest level of...

  1. Fixation of Soft-inner Part of Oil Palm Trunk by Close System Compression Method

    NASA Astrophysics Data System (ADS)

    Hartono, R.; Dwianto, W.; Wahyudi, I.; Febrianto, F.; Morooka, T.

    2017-03-01

    Compression by closes system compression (CSC) improved quality of the soft-inner part of oil palm trunk (S-OPT). The problem of compressed-wood was spring back or recovery of set, if it was exposed to moisture content. The objective of these study were to evaluate the recovery of set (RS) and weight loss (WL) of S-OPT by CSC. These methods were compared with heat treatment (HT) and steam treatment (ST). Density of S-OPT was 0.3 g/cm3. All samples were compressed to compression ratio of 50%. The compression of HT method used the temperatur of 120, 140, 160, 180 and 200 °C for 0, 10, 30, 60 and 180 minutes; and ST method used temperature of 120, 140, 160, 170 and 180 °C for 0, 5, 10 and 30 minute; while CSC method used temperature of 120, 140, 160, 180 and 200 °C for 0, 10, 20, 30 and 40 minutes. The results showed that the temperature and compression time contributed to the RS and WL value for all methods. Increasing compression temperature and time leads to decreased the RS value and to increased the WL value. The lower RS value indicated that S-OPT fixation would be better or high dimensional stability. Fixation of S-OPT by ST method was achieved at temperature of 170 °C for 30 min, CSC at temperature of 180 °C for 30 min, while HT method has not fixated until 200 °C for 180 min.

  2. Experimental fracture model versus osteotomy model in metacarpal bone plate fixation.

    PubMed

    Ochman, S; Vordemvenne, T; Paletta, J; Raschke, M J; Meffert, R H; Doht, S

    2011-01-01

    Introduction. Osteotomy or fracture models can be used to evaluate mechanical properties of fixation techniques of the hand skeleton in vitro. Although many studies make use of osteotomy models, fracture models simulate the clinical situation more realistically. This study investigates monocortical and bicortical plate fixation on metacarpal bones considering both aforementioned models to decide which method is best suited to test fixation techniques. Methods. Porcine metacarpal bones (n = 40) were randomized into 4 groups. In groups I and II bones were fractured with a modified 3-point bending test. The intact bones represented a further control group to which the other groups after fixation were compared. In groups III and IV a standard osteotomy was carried out. Bones were fixated with plates monocortically (group I, III) and bicortically (group II, IV) and tested for failure. Results. Bones fractured at a mean maximum load of 482.8 N ± 104.8 N with a relative standard deviation (RSD) of 21.7%, mean stiffness was 122.3 ± 35 N/mm. In the fracture model, there was a significant difference (P = 0.01) for maximum load of monocortically and bicortically fixed bones in contrast to the osteotomy model (P = 0.9). Discussion. In the fracture model, because one can use the same bone for both measurements in the intact state and the bone-plate construct states, the impact of inter-individual differences is reduced. In contrast to the osteotomy model there are differences between monocortical and bicortical fixations in the fracture model. Thus simulation of the in vivo situation is better and seems to be suitable for the evaluation of mechanical properties of fixation techniques on metacarpals.

  3. Comparison of interface contact profiles of a new minimum contact locking compression plate and the limited contact dynamic compression plate

    PubMed Central

    Xiong, Yan; Zhao, Yu Feng; Xing, Shu Xing; Du, Quan Yin; Sun, Hong Zhen; Wang, Zi Ming; Wu, Si Yu

    2009-01-01

    In this study, we investigated whether or not a new minimum contact locking compression plate (MC-LCP) can provide advantages over the limited contact dynamic compression plate (LC-DCP) in the context of interface contact area and force. Six matched pairs of cadaveric bones were used for each of three bone types of the humerus, radius and ulna. For each bone type, one of two bone plates was fixed to either of two matched cadaveric bones at the middle of the diaphysis. The interface contact area and force of the plate fixed to three types of human cadaveric bones were evaluated using Fuji prescale pressure sensitive film. Data were quantitated using computer-assisted image analysis. Results showed that the average force between the MC-LCP and humerus or radius was about half of that of the LC-DCP. And the average force between the MC-LCP and ulna was one third less than that of the LC-DCP. Meanwhile, the interface contact area between the MC-LCP and humerus or radius was also about half of that of the LC-DCP, and the interface contact area between the MC-LCP and ulna was less than one third of that of the LC-DCP. These results indicate that the MC-LCP has lower interface contact area and lower average force than that of the LC-DCP. Thus, the MC-LCP system may be a good alternate to treat forearm diaphyseal fractures. PMID:19603166

  4. Analysis of Sternal Fixation Results According to Plate Type in Sternal Fracture

    PubMed Central

    Byun, Chun Sung; Park, Il Hwan; Hwang, Wan Jin; Lee, Yeiwon; Cho, Hyun Min

    2016-01-01

    Background Sternal fractures are relatively rare, and caused mainly by blunt anterior chest wall trauma. In most cases, sternal fractures are treated conservatively. However, if the patient exhibits problematic symptoms such as intractable chest wall pain or bony crepitus due to sternal instability, surgical correction is indicated. But no consensus exists regarding the most appropriate surgical method. We analyzed the results of surgical fixation in cases of sternal fracture in order to identify which surgical method led to the best outcomes. Methods We retrospectively reviewed the medical records of patients with sternal fractures from December 2008 to December 2011, and found 19 patients who underwent open reduction and internal fixation of the sternum with a longitudinal plate (L-group) or a T-shaped plate (T-group). We investigated patients’ characteristics, clinical details regarding each case of chest trauma, the presence of other associated injuries, the type of open reduction and fixation, whether a combined operation was performed, and postoperative complications. Results Of the 19 patients, 10 patients (52.6%) were male, and their average age was 56.8 years (range, 32 to 82 years). Seven patients (36.8%) had isolated sternal fractures, while 12 (63.2%) had other associated injuries. Seven patients (36.8%) were in the L-group and 12 patients (63.2%) were in the T-group. Three patients in the L-group (42.9%) showed a loosening of the fixation. In all patients in the T-group, the fracture exhibited stable alignment. Conclusion Open reduction and internal fixation with a T-shaped plate in sternal fractures is a safer and more efficient treatment method than treatment with a longitudinal plate, especially in patients with a severely displaced sternum or anterior flail chest, than a longitudinal plate. PMID:27733996

  5. Closed treatment of condylar fractures by intermaxillary fixation with thermoforming plates.

    PubMed

    Terai, Haruhiko; Shimahara, Masashi

    2004-02-01

    We report a new intermaxillary fixation (IMF) method for condylar fractures using a thermoforming plate. Fifteen cases of condylar fracture were selected and thermoforming plates were applied. The patient's recover was uneventful in all 15 cases, and the period of IMF ranged from 7 to 17 days, (mean 12) for the following 7 days IMF was used only at night together with functional jaw training during the day. The outcome was good. IMF using a thermoforming plate may be a useful technique for selected condylar fractures.

  6. One size does not fit all: distal radioulnar joint dysfunction after volar locking plate fixation.

    PubMed

    Jones, Christopher W; Lawson, Richard D

    2014-02-01

    Background Fractures of the distal radius are among the most common injuries treated by orthopedic surgeons worldwide. Failure to restore distal radius alignment can lead to fracture malunion and poor clinical outcomes, including distal radioulnar joint (DRUJ) instability and limitation of motion. Case Description We present a unique case of DRUJ dysfunction following volar plate fixation of bilateral distal radius fractures and analyze the biomechanical causes of this complication. As a result of a relatively excessive tilt of the precontoured locking plate (in comparison to the patient's particular anatomy), the fracture on one side was "over-reduced," disrupting the biomechanics of the DRUJ, causing a supination block. Clinical Relevance Volar locking plates are not a panacea to all distal radius fractures. Plate selection and fixation technique must include consideration of patient anatomy. Robust plates offer the advantage of providing rigid fixation but can be difficult to contour when reconstructing normal anatomy. Restoration of patient-specific anatomy is crucial to the management of distal radius fractures.

  7. Proximal humeral fracture fixation: locking plate construct ± intramedullary fibular allograft.

    PubMed

    Chow, Roxanne M; Begum, Farhana; Beaupre, Lauren A; Carey, Jason P; Adeeb, Samer; Bouliane, Martin J

    2012-07-01

    Locking plate constructs for proximal humeral fractures can fail due to varus collapse, especially in osteoporotic bone with medial cortex comminution. Augmentation, using a fibular allograft as an intramedullary bone peg, may strengthen fixation preventing varus collapse. This study investigated the ability of the augmented locking plate construct to withstand repetitive varus stresses relative to the nonaugmented construct. Proximal humeral fractures with medial comminution were simulated by performing wedge-shaped osteotomies at the surgical neck in cadaveric specimens. For each cadaver (n = 8), 1 humeral fracture was fixated with the locking plate construct alone and the other with the locking plate construct plus ipsilateral fibular autograft augmentation. The humeral head was immobilized and a repetitive, medially directed load was applied to the humeral shaft until construct collapse or until 25000 cycles were completed. No augmented construct collapsed. In comparison, 6 of 8 nonaugmented constructs collapsed (P < .05). Collapse in the 6 nonaugmented constructs occurred after an average ±SD of 6604 ± 1984 cycles. Screw penetration of the articular surface was found in only 1 of the nonaugmented constructs. Fibular allograft augmentation increased the ability of the locking plate to withstand repetitive varus loading. Clinically, this may assist proximal humeral fracture fixation in osteoporotic bone with medial cortex comminution. Crown Copyright © 2012. Published by Mosby, Inc. All rights reserved.

  8. Pin guidance of reconstruction plate contour: an expanded role of external fixation.

    PubMed

    Jaquet, Yves; Higgins, Kevin M; Enepekides, Danny J

    2011-09-01

    This article presents a modification of intraoperative external fixation for mandibular reconstruction with free tissue flaps. This technique is indicated when preregistration of the reconstruction plate is not possible due to transmandibular tumor extension. Once standard external fixation has been carried out and prior to segmental mandibulectomy, additional pins are fixed to the connecting rod that delineate the mandibular contour in three-dimensional (3D) space. Following mandibulectomy, these pins allow accurate contouring of the reconstruction plate and improved restoration of mandibular contour, projection, and dental occlusion. A step-by-step description of the technique using models and intraoperative photos is presented. This method of mandibular reconstruction is a simple and time-effective alternative to intraoperative computer navigation and 3D modeling in select cases of oral carcinoma where tumor infiltration of the outer mandibular cortex precludes prebending of the reconstruction plates.

  9. Influence of screw insertion order on compression generated by bone plates in a fracture model.

    PubMed

    Jermyn, K; Roe, S C

    2011-01-01

    Present recommendations regarding order of screw insertion for compression plate osteosynthesis in veterinary training are variable. We hypothesized that placement of a neutrally positioned screw would reduce the magnitude of compression that could be generated by a subsequently placed compression screw. Canine tibial diaphyseal segments were fixed to a plate attached to a bone surrogate and load cell, and the compression generated by screw tightening was measured. Three different screw insertion order patterns were evaluated using both dynamic compression plate (DCP) and limited contact dynamic compression plate (LC-DCP) implants. In group CN, the first screw was placed in compression mode and the second in neutral mode; in group NC, the first screw was placed in neutral mode and the second in compression mode; in group LNC, the first screw was placed partially tightened in neutral mode and the second in compression mode followed by complete tightening of the neutral screw. Screw insertion order significantly influenced the amount of compression generated with both groups CN and LNC demonstrating significantly greater compression generation when compared with group NC (p <0.0001). Compression generated by group CN constructs was also significantly greater than group LNC (p = 0.0013). Evaluation of group CN data to assess the influence of plate and drill guide combinations on compressive force generated did not demonstrate a statistically significant difference. To maximize compression using a load screw in a bone plate, following securement of the opposite bone fragment to the plate, it should be placed before a neutral screw is placed.

  10. Reverse distal femoral locking compression plate a salvage option in nonunion of proximal femoral fractures

    PubMed Central

    Dumbre Patil, Sampat S; Karkamkar, Sachin S; Patil, Vaishali S Dumbre; Patil, Shailesh S; Ranaware, Abhijeet S

    2016-01-01

    Background: When primary fixation of proximal femoral fractures with implants fails, revision osteosynthesis may be challenging. Tracts of previous implants and remaining insufficient bone stock in the proximal femur pose unique problems for the treatment. Intramedullary implants like proximal femoral nail (PFN) or surface implants like Dynamic Condylar Screw (DCS) are few of the described implants for revision surgery. There is no evidence in the literature to choose one implant over the other. We used the reverse distal femur locking compression plate (LCP) of the contralateral side in such cases undergoing revision surgery. This implant has multiple options of fixation in proximal femur and its curvature along the length matches the anterior bow of the femur. We aimed to evaluate the efficacy of this implant in salvage situations. Materials and Methods: Twenty patients of failed primary proximal femoral fractures who underwent revision surgery with reverse distal femoral locking plate from February 2009 to November 2012 were included in this retrospective study. There were 18 subtrochanteric fractures and two ipsilateral femoral neck and shaft fractures, which exhibited delayed union or nonunion. The study included 14 males and six females. The mean patient age was 43.6 years (range 22–65 years) and mean followup period was 52.1 months (range 27–72 months). Delayed union was considered when clinical and radiological signs of union failed to progress at the end of four months from initial surgery. Results: All fractures exhibited union without any complications. Union was assessed clinically and radiologically. One case of ipsilateral femoral neck and shaft fracture required bone grafting at the second stage for delayed union of the femoral shaft fracture. Conclusions: Reverse distal femoral LCP of the contralateral side can be used as a salvage option for failed fixation of proximal femoral fractures exhibiting nonunion. PMID:27512218

  11. Locking plate fixation of periprosthetic femur fractures with and without cerclage wires.

    PubMed

    Ebraheim, Nabil A; Sochacki, Kyle R; Liu, Xiaochen; Hirschfeld, Adam G; Liu, Jiayong

    2013-08-01

    The number of patients requiring knee and hip arthroplasty has been steadily increasing, and periprosthetic fractures are on the rise. Locking plates are the most common treatment for periprosthetic fractures, but the use of cerclage wires with locking plate fixation has been controversial. Forty-seven patients with periprosthetic femur fractures were reviewed retrospectively. Twenty-four patients received locking plate alone and twenty-three patients were treated with locking plate and cerclage wires. Patients were evaluated for clinical and radiographic signs of union at two, six, twelve, twenty-four, and forty-eight weeks postoperatively. The average follow-up time in the plate group was 9.4 ± 6.7 months, while it was 6.0 ± 4.2 months in the cerclage wire group. The time to union in the cerclage wire group (3.6 ± 1.0 months) was significantly less than the plate group (4.8 ± 2.6 months). The group with the cerclage wires had a significantly lower revision rate of 0% compared to 20.8%. There was no statistical significance of union rate and complication rate between the two groups. Cerclage wires used with locking plate fixation successfully treats periprosthetic fractures of the femur with faster time to union, less complication, and fewer revisions. © 2013 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

  12. Internal fixation of patellar apex fractures with the basket plate: 25 years of experience.

    PubMed

    Matejčić, Aljoša; Ivica, Mihovil; Jurišić, Darko; Ćuti, Tomislav; Bakota, Bore; Vidović, Dinko

    2015-11-01

    Comminution of the patellar apex is amenable to internal fixation by standard techniques and usually requires partial patellectomy. In our institution, multifragmentary fractures of the distal pole are treated with the basket plate, which is shaped to fit the geometry of the patellar apex. This implant has been used in our institution for over 25 years. The aim of this study was to evaluate long-term results of internal fixation of comminuted fractures of the patellar apex with the basket plate. A total of 142 patients with fracture of the distal pole of the patella were treated with the basket plate between 1988 and 2013. Functional evaluation was conducted using the modified Cincinnati knee rating system. A total of 98 patients were available for late functional evaluation. There were no infections or implant-related problems during the follow-up period. All fractures healed within 8 to 10 weeks. There were three cases of early revision because of improper use of the implant and incorrect indication. Functional outcome following internal fixation with the basket plate was excellent in 80 patients and good in 18; there were no poor results. Internal fixation with the basket plate is recommended for management of multifragmentary fractures of the patellar apex because this method enables early, unrestricted knee motion, and provides reliable healing and good functional outcome. This method is an alternative to partial patellectomy and is considered a patella-saving procedure; therefore, the use of the basket plate is strongly recommended for the treatment of distal pole fractures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Fracture of the distal radius: risk factors for complications after locked volar plate fixation.

    PubMed

    Soong, Maximillian; van Leerdam, Roderick; Guitton, Thierry G; Got, Christopher; Katarincic, Julia; Ring, David

    2011-01-01

    To identify risk factors for complications after volar locking plate fixation of distal radius fractures. We assessed early postoperative complications in 594 patients with fracture of the distal radius repaired with a volar locking plate and a minimum 1-month evaluation in the medical record. Later complications were assessed among 321 patients as a subset of the original cohort with a minimum 6 months' evaluation. We compared patient demographics, fracture characteristics, and aspects of management between patients with and without complications in bivariate analysis. Multivariable logistic regression analysis was applied to identify the factors independently associated with complications. A total of 47 complications were documented in the medical record. Early complications occurred in 24 of 594, including 8 intra-articular screws and 7 patients with loss of fixation. Late complications occurred in 23 of 321, including 14 patients diagnosed with tendon irritation (one rupture of the flexor pollicis longus tendon) and 5 patients who had subsequent surgery to address dysfunction of the distal radioulnar joint (malunion, synostosis, and arthrofibrosis). Of the 47 complications, 26 were attributed to the plate, of which 9 were considered major (intra-articular screws and tendon rupture; 1.3% (8 out of 594) and less than 1% (1 out of 321) of the early and late groups, respectively). In the logistic regression models, fall from a height and an ipsilateral elbow injury were positive independent predictors of early complications, whereas high-volume surgeons and plates other than the most commonly used plate were positive independent predictors of later complications. Volar locking plate fixation of distal radius fractures was associated with relatively few plate-related complications in our institutions. Factors indicating higher energy or complexity predicted early complications. The most common late complication was tendon irritation, which is less discrete and

  14. Finite Element-Derived Surrogate Models of Locked Plate Fracture Fixation Biomechanics.

    PubMed

    Wee, Hwabok; Reid, J Spence; Chinchilli, Vernon M; Lewis, Gregory S

    2017-03-01

    Internal fixation of bone fractures using plates and screws involves many choices-implant type, material, sizes, and geometric configuration-made by the surgeon. These decisions can be important for providing adequate stability to promote healing and prevent implant mechanical failure. The purpose of this study was to develop mathematical models of the relationships between fracture fixation construct parameters and resulting 3D biomechanics, based on parametric computer simulations. Finite element models of hundreds of different locked plate fixation constructs for midshaft diaphyseal fractures were systematically assembled using custom algorithms, and axial, torsional, and bending loadings were simulated. Multivariate regression was used to fit response surface polynomial equations relating fixation design parameters to outputs including maximum implant stresses, axial and shear strain at the fracture site, and construct stiffness. Surrogate models with as little as three regressors showed good fitting (R (2) = 0.62-0.97). Inner working length was the strongest predictor of maximum plate and screw stresses, and a variety of quadratic and interaction terms influenced resulting biomechanics. The framework presented in this study can be applied to additional types of bone fractures to provide clinicians and implant designers with clinical insight, surgical optimization, and a comprehensive mathematical description of biomechanics.

  15. Dynamic Fixation of Humeral Shaft Fractures Using Active Locking Plates: A Prospective Observational Study

    PubMed Central

    Madey, Steven M.; Tsai, Stanley; Fitzpatrick, Daniel C.; Earley, Kathleen; Lutsch, Michael

    2017-01-01

    Abstract Background Rigid locked plating constructs can suppress fracture healing by inhibiting interfragmentary motion required to stimulate natural bone healing by callus formation. Dynamic fixation with active locking plates reduces construct stiffness, enables controlled interfragmentary motion, and has been shown to induce faster and stronger bone healing in vivo compared to rigid locking plates. This prospective observational study represents the first clinical use of active locking plates. It documents our early clinical experience with active plates for stabilization of humeral shaft fractures to assess their durability and understand potential complications. Methods Eleven consecutive patients with humeral shaft fractures (AO/OTA types 12 A-C) were prospectively enrolled at a level I and a level II trauma center. Fractures were stabilized by using active locking plates without supplemental bone graft or bone morphogenic proteins. The screw holes of active locking plates are elastically suspended in elastomer envelopes inside the plate, enabling up to 1.5 mm of controlled interfragmentary motion. Progression of fracture healing and integrity of implant fixation was assessed radiographically at 3, 6, 12, and 24 weeks post surgery. Patient-reported functional outcome measures were obtained at 6, 12, and 24 weeks post surgery. The primary endpoint of this study was plate durability in absence of plate bending or breakage, or failure of the elastically suspended locking hole mechanism. Secondary endpoints included fracture healing, complications requiring revision surgery, and functional outcome scores. Results The eleven patients had six simple AO/ OTA type 12A fractures, three wedge type 12B fractures, and two comminuted type 12C fracture, including one open fracture. All active locking plates endured the 6-month loading period without any signs of fatigue or failure. Ten of eleven fractures healed at 10.9 ± 5.2 weeks, as evident by bridging callus and pain

  16. Finite element analysis of the stability of combined plate internal fixation in posterior wall fractures of acetabulum

    PubMed Central

    Liu, Xi-Ming; Pan, Chang-Wu; Wang, Guo-Dong; Cai, Xian-Hua; Chen, Lei; Meng, Cheng-Fei; Huang, Jin-Cheng

    2015-01-01

    Objective: This study aims to explore the mechanical stability of combined plate internal fixation in posterior wall fractures of the acetabulum. Methods: The fracture and internal fixation models were established in this study and they were divided into four kinds of internal fixation models, finite element analysis was performed. The four groups were 2 mini-plates and 1 reconstruction plate fixation (A), Reconstruction plate internal fixation group (B), 2 screws internal fixation group (C) and mini-plates internal fixation group (D). The displacement of each node was measured and evaluated. Results: There was no distortion in the geometric shape of the finite element model. The results of stress showed that it was less in the anterior pelvic ring and distributed uniform in labrum acetabulare; the stress was bigger in the upper and middle of sacroiliac joint and sciatic notch in sitting position. Conclusions: Combined plate internal fixation for posterior wall fractures of acetabular were stable and reliable, it is better than the other three methods. PMID:26550272

  17. Proximal humeral fracture fixation: multicenter study with carbon fiber peek plate.

    PubMed

    Rotini, R; Cavaciocchi, M; Fabbri, D; Bettelli, G; Catani, F; Campochiaro, G; Fontana, M; Colozza, A; De Biase, C F; Ziveri, G; Zapparoli, C; Stacca, F; Lupo, R; Rapisarda, S; Guerra, E

    2015-09-01

    Locking plate fixation is a reliable treatment for many displaced proximal humeral fractures. Carbon fiber-reinforced-poly-ether-ether-ketone (CFR-PEEK) plates have recently been introduced as an alternative to traditional metallic plates. In a multicenter study involving the Orthopedic Services of 6 Italian hospitals, 182 patients with a proximal humeral fracture were treated with a Diphos H (Lima Corporate, San Daniele del Friuli, Italy) CFR-PEEK plate, 160 of whom were followed clinically and radiographically for 2 years or more. Fractures were classified by Neer's system. The functional results were assessed by Constant and DASH scores. The average time to radiographic healing was 5.6 months in 158 of 160 cases. Mean Constant score was 76, and mean DASH score was 28 at 2 years. There were two nonunions (one septic and one aseptic) and 13 cases of partial (9) or massive (4) humeral head necrosis. In three of the 78 patients treated with the first-generation plates, hardware breakage happened during the operation and the plate was replaced. There was no failure among the cases treated with the thicker second-generation plate. In eight cases, there was a perforation of the humeral head by the cephalic screws. CFR-PEEK plates proved as reliable as metallic plates in the treatment of proximal humeral fractures. The advantages of these new devices include a better visualization of fracture reduction during intraoperative fluoroscopic assessment and easy hardware removal due to the absence of screw-plate cold fusion.

  18. Early rehabilitation following less invasive surgical stabilisation plate fixation for distal femoral fractures.

    PubMed

    Smith, T O; Hedges, C; MacNair, R; Schankat, K

    2009-06-01

    The less invasive surgical stabilisation (LISS) plate fixation method is an orthopaedic procedure for the fixation of distal femoral fractures. Early physiotherapy treatments of motion and mobilisation have been advocated following this procedure. This article critically appraises the evidence base assessing the early rehabilitation of patients following LISS fixation for distal femoral fractures. A review of EMBASE, Medline, CINAHL and AMED, and a hand search were undertaken. Two independent reviewers identified all eligible articles. Two reviewers extracted the data, which were verified by a third reviewer. All included articles were critically appraised by two independent reviewers using the Critical Appraisal Skills Programme tool. Seventeen case series assessing 508 patients with 535 fractures were reviewed. No clinical trials comparing physiotherapy programmes were identified. The review identified that following LISS fixation for distal femoral fractures, patients begin range-of-motion exercises immediately and are initially required to restrict weight-bearing following surgery. It remains unclear whether casts, braces or immobilisation aids are applied during the initial postoperative period. The efficacy of different physiotherapy protocols following LISS fixation for distal femoral fractures remains unclear. Further well-designed randomised controlled trials are required to compare different postoperative physiotherapy rehabilitation programmes for patients following LISS fixation of distal femoral fractures in order to determine the optimal postoperative management for this complex patient group.

  19. Complex AO type C3 distal femur fractures: Results after fixation with a lateral locked plate using modified swashbuckler approach

    PubMed Central

    Agrawal, Anuj; Kiyawat, Vivek

    2017-01-01

    Background: Complex AO type C3 fractures of the distal femur are challenging injuries, fraught with complications such as malunion and stiffness. We prospectively evaluated a consecutive series of patients with complex AO type C3 distal femur fractures to determine the clinicoradiological outcome after fixation with a single locked plate using modified swashbuckler approach. Materials and Methods: 12 patients with C3 type distal femur fractures treated with a lateral locked plate, using a modified swashbuckler approach, were included in the study. The extraarticular component was managed either by compression plating or bridge plating (transarticular approach and retrograde plate osteosynthesis) depending on the fracture pattern. Primary bone grafting was not done in any case. The clinical outcome at 1 year was determined using the Knee Society Score (KSS). The presence of any secondary osteoarthritis in the knee joint was noted at final followup. Results: All fractures united at a mean of 14.3 ± 4.7 weeks (range 6–26 weeks). There were no significant complications such as nonunion, deep infection, and implant failure. One of the patients underwent secondary bone grafting at 3 months. The mean range of motion of the knee was 120° ± 14.8° (range 105°–150°). Seven patients had excellent, three patients had good and two patients had a fair outcome according to the KSS at 1 year. At a mean followup of 17.6 months, three patients showed radiological evidence of secondary osteoarthritis of the knee joint. However, only one of these patients was symptomatic. Conclusion: The results of complex C3 type distal femur fractures, fixed with a single lateral locked plate using a modified swashbuckler approach, are encouraging, with a majority of patients achieving good to excellent outcome at 1 year. PMID:28216747

  20. Fixation of multifragmentary patella fractures using a bilateral fixed-angle plate.

    PubMed

    Thelen, Simon; Betsch, Marcel; Schneppendahl, Johannes; Grassmann, Jan; Hakimi, Mohssen; Eichler, Christian; Windolf, Joachim; Wild, Michael

    2013-11-01

    This biomechanical study is the first to compare 3 fixation methods-bilateral fixed-angle plate, modified anterior tension wiring, and cannulated lag screws with anterior tension wiring-in multifragmentary distal patella fractures. A T-shaped 3-part fracture simulating a multifragmentary articular distal patella fracture (AO/OTA 34-C2.2) was created in 18 human cadaver knee specimens. Three groups were created using homogenous ages and bone mineral densities based on the fixation method received. Repetitive testing over 100 cycles was performed by moving the knee against gravity from 90° flexion to full extension. Failure was defined as fracture displacement greater than 2 mm. In all patellae using fixed-angle plates, an anatomical fracture reduction could be maintained throughout cyclic testing, whereas anterior tension wiring and lag screws with tension wiring showed significant fracture displacement after 100 cycles, with mean fracture gaps of 2.0±1.3 and 1.9±1.6 mm, respectively. The differences in fracture gaps between the fixed-angle plate group and the other 2 groups were statistically significant. In both groups using tension wiring, half of the constructs (3 of 6 in each group) failed due to a fracture displacement greater than 2 mm. The bilateral fixed-angle plate was the only fixation method that sustainably stabilized a multifragmentary articular distal patella fracture during cyclic loading when compared with modified anterior tension wiring and cannulated lag screws with anterior tension wiring.

  1. Open Reduction and Volar Plate Fixation of Dorsally Displaced Distal Radius Fractures: A Prospective Study of Functional and Radiological Outcomes

    PubMed Central

    Sadasivan, Anand Kumar; Hegde, Anoop; Shetty, Ashwin

    2016-01-01

    Introduction The fractures of the distal radius have always posed a unique challenge to the orthopaedic fraternity. The complex ligamentous and bony anatomy offers a wide variety of fractures to be dealt with around this zone. Over the years these injuries have become common especially in the elderly age group as well as the implants and surgical techniques have improved. Aim To assess the radiological and functional outcome after fixation of intra-articular dorsally displaced distal radius fractures with open reduction and volar Locking Compression Plate fixation (LCP). To study the complications occurring with this technique. Materials and Methods A prospective study was conducted in the Department of Orthopaedics at ARS Hospital, Tirupur, Tamil Nadu, from June 2015 to June 2016. A total of 20 skeletally mature patients with Lidstrom class 2D and 2E fresh closed distal radius fractures were enrolled in the study. All the patients underwent open reduction with locking compression plating with titanium LCPs using the volar approach. The patients were reviewed regularly at three, six, 12 and 24 weeks. Final assessment of radiographic fracture union was done and scored as per the ‘Radiographic Scoring System to Evaluate Union of Distal Radius Fractures {Radius Union Scoring System (RUSS)}’ and the functional assessment of the wrist was done using the Mayo wrist score. The final results were tabulated and calculated statistically using ‘frequency and proportions’ and ‘Chi-square tests’ were used to assess the test of association. Results Of the 20 patients reviewed, one patient had excellent Mayo wrist score, five had good scores, 12 had satisfactory and two patients had poor results. Seven patients had a RUSS score less than five points and four patients had RUSS score of five points, four patients had six points, two patients had seven points and three patients had eight points. One patient was noted to have dorsal collapse of the fracture during the

  2. Locking attachment plate fixation around a well-fixed stem in periprosthetic femoral shaft fractures.

    PubMed

    Kim, Min Bom; Cho, Jae-Woo; Lee, Young Ho; Shon, Won-Yong; Park, Jung Wee; Kim, Jinil; Oh, Jong-Keon

    2017-07-08

    Periprosthetic fractures are difficult to manage. Plating technique has been considered a reliable form of management of periprosthetic fractures with a well-fixed stem, but a dependable and stable method of plate fixation to the bone is lacking. This study reports the clinical results using a locking attachment plate (LAP) instead of cable fixation to fix locking plates to a periprosthetic femoral shaft fracture. Nineteen patients with periprosthetic femoral shaft fractures around well-fixed stemmed implants were studied between August 2012 and December 2014. Patients were followed up for at least 1 year postoperatively. Median age was 74 years (range 56-96 years). Fractures were classified according to the Unified Classification System, Vancouver classification, and Su classification. Open reduction was performed under minimal incision and the locking plate was fixed to the lateral cortex of the femoral shaft. The part of the shaft without a stem was fixed to the plate using 5.0-mm locking screws, and the part with an underlying stem was fixed using 3.5-mm locking screws through the LAP instead of cables. Postoperatively, patients were managed using general principles for femoral shaft fractures. Average follow-up was 16 months (range 12-36 months). All cases achieved fracture healing without loss of reduction. There were no cases of implant breakage or stem loosening at final follow-up. The average number of LAPs per fixation construct was 2.1 (range 1-4), and the average number of 3.5-mm locking screws through each LAP was 3.3 (range 2-4). The average value of plate screw density was 0.55 (range 0.37-0.8), and the average working length was four holes (range 2-8). Using the LAP to manage periprosthetic fractures with a well-fixed stem could obviate the need for cable around the stem area and yield acceptable outcomes.

  3. Are there too many screw holes in plates for fracture fixation?

    PubMed

    Lv, Hongzhi; Chang, Wenli; Yuwen, Peizhi; Yang, Na; Yan, Xiaoli; Zhang, Yingze

    2017-04-21

    Implant breakage after the fixation of traumatic fractures is rare; however, when it occurs, it is debilitating for the patients and a challenge for surgeons. The purpose of this study was to analyze and identify the independent risk factors for implant breakage of traumatic fractures treated with plate osteosynthesis. We reviewed the medical records of patients with a fracture to any part of their four extremities, clavicle, hand or foot, who underwent surgical plate osteosynthesis from January 2005 to January 2015, and who sustained a subsequent implant breakage. Kaplan-Meier univariate and multivariate Cox regressions were performed to identify independent associations of potential risk factors for implant breakage in this cohort. We identified 168 patients who underwent plate osteosynthesis surgery and had subsequent internal fixator breakage. The mean patient age was 40.63 ± 16.71 years (range, 3 to 78 years), with 72.0% (121) males and 28.0% (47) females. The average time between surgery and implant breakage was 12.85 ± 12.42 months (range, 1 to 60 months). In the final regression model, we show that inserting screws close to the fracture line is an independent predictive risk factor for implant breakage (HR, 2.165, 95%CI, 1.227 to 3.822; P = 0.008). We found that inserting screws close to the fracture line is related to an increased risk of internal fixator breakage in patients treated with plate osteosynthesis after fracture. Plates with additional holes likely lead to an increased risk of implant breakage, presumably because surgeons cannot resist inserting extra screws into the holes adjacent to the fracture line, which reduces the stiffness of the plate. We have addressed this problem by designing a plate without holes adjacent to the fracture line.

  4. Comparison of intramedullary nail and plate fixation in distal tibia diaphyseal fractures close to the mortise.

    PubMed

    Yavuz, Umut; Sökücü, Sami; Demir, Bilal; Yıldırım, Timur; Ozcan, Cağrı; Kabukçuoğlu, Yavuz Selim

    2014-05-01

    In this study, we aimed to compare the functional and radiological results of intramedullary nailing and plate fixation techniques in the surgical treatment of distal tibia diaphyseal fractures close to the ankle joint. Between 2005 and 2011, 55 patients (32 males, 23 females; mean age 42 years; range 15 to 72 years) who were treated with intramedullary nailing (21 patients) or plate fixation (34 patients) due to distal tibia diaphyseal fracture were included in the study. The average follow-up period was 27.6 months (range, 12-82 months). The patients were evaluated with regard to nonunion, malunion, infection, and implant irritation. The AOFAS (American Orthopaedic Foot and Ankle Society) scale was used for the clinical evaluation. No statistically significant difference was found between the two surgical methods with respect to unification time, AOFAS score, accompanying fibula fracture, material irritation, and malunion. Nine patients had open fractures, and these patients were treated with plate fixation (p=0.100). Nonunion developed in three patients who were treated with plates. Infection occurred in one patient. Anterior knee pain was significantly higher in patients who were treated with intramedullary nails. There was no malunion in any patient. As the distal fragment is not long enough, plate fixation technique is usually preferred in the treatment of distal tibia diaphyseal fractures. In this study, we observed that if the surgical guidelines are followed carefully, intramedullary nailing is an appropriate technique in this kind of fracture. The malunion rates are not significantly increased, and it also has the advantages of being a minimally invasive surgery with fewer wound problems.

  5. Ability of modern distal tibia plates to stabilize comminuted pilon fracture fragments: Is dual plate fixation necessary?

    PubMed

    Penny, Phillip; Swords, Michael; Heisler, Jason; Cien, Adam; Sands, Andrew; Cole, Peter

    2016-08-01

    The purpose of this study was to examine the screw trajectory of ten commercially available distal tibia plates and compare them to common fracture patterns seen in OTA C type pilon fractures to determine their ability to stabilize the three most common fracture fragments while buttressing anterolateral zones of comminution. We hypothesized that a single plate for the distal tibia would fail to adequately stabilize all three main fracture fragments and zones of comminution in complex pilon fractures. Ten synthetic distal tibia sawbones models were used in conjunction with ten different locking distal tibia plate designs from three manufacturers (Depuy Synthes, J&J Co, Paoli, PA; Smith & Nephew, Memphis, TN; and Stryker, Mawa, NJ). Both medial and anterolateral plates from each company were utilized and separately applied to an individual sawbone model. Three implants allowing variable angle screw placement were used. The location of the locking screws and buttress effect 1cm above the articular surface was noted for each implant using axial computed tomography (CT). The images were then compared to a recently published "pilon fracture map" using an overlay technique to establish the relationship between screw location and known common fracture lines and areas of comminution. Each of the three main fragments was considered "captured" by a screw if it was purchased by at least two screws thereby controlling rotational forces on each fragment. Three of four anterolateral plates lacked stable fixation in the medial fragment. Of the 4 anterolateral plates used, only the variable angle anterolateral plate by Depuy Synthes captured the medial fragment with two screws. All four anterolateral plates buttressed the area of highest comminution and had an average of 1.25 screws in the medial fragment and an average of 3 screws in the posterolateral fragment. All five direct medial plates had variable fixation within anterolateral and posterolateral fragments with an average of

  6. Plate fixation of midshaft clavicular fractures: patient-reported outcomes and hardware-related complications.

    PubMed

    Naimark, Micah; Dufka, Faustine L; Han, Richard; Sing, David C; Toogood, Paul; Ma, C Benjamin; Zhang, Alan L; Feeley, Brian T

    2016-05-01

    Recent studies report high hardware removal rates after plate fixation of midshaft clavicular fractures. Precontoured clavicle plates may decrease hardware-related complications while improving healing rates and patient-reported outcomes (PROs). Using a private-payer national database, we identified 7826 patients who underwent clavicle open reduction and internal fixation (ORIF) in 2007 to 2011. Database patients were tracked for 2 years to assess hardware removal and revision fixation. In addition, we retrospectively identified 73 patients who underwent plate fixation of midshaft clavicular fractures at our institution. These patients completed the Disabilities of Arm, Shoulder and Hand (DASH) assessment, the EQ-5D (EuroQol, Rotterdam, The Netherlands) quality of life assessment, and a hardware-related outcomes survey. Among 7826 database patients, 994 (12.7%) underwent hardware removal and 78 (1%) required revision ORIF. The annual incidence of clavicle ORIF increased 61.5% between 2007 and 2011. In our institutional cohort, 56 patients (77%) were fixed with precontoured plates and 17 (23%) with standard plates. At a mean follow-up of 4.2 years, 11 patients (15%) underwent hardware removal and 1 patient (1.4%) experienced nonunion. Patients reported excellent outcomes, with average DASH of 4.0 ± 8.9 and EQ-5D of 0.89 ± 0.19. There were no differences in PROs, hardware removal, or union rate between plate types, although our study was underpowered for these outcomes. Patients who underwent hardware removal reported lower DASH, EQ-5D, satisfaction, and shoulder function compared with patients with hardware retained. Women were more likely to undergo hardware removal in the institutional (P = .009) and the database (P < .001) cohorts. Displaced midshaft clavicle fractures have high union rates with precontoured plate fixation. Women are 4 times more likely than men to have hardware removed. Patients undergoing clavicle hardware removal report worse long

  7. Treatment of the femoral shaft nonunion with double plate fixation and bone grafting: A case series of 14 patients.

    PubMed

    Maimaitiyiming, Asihaerjiang; Amat, Abdusami; Rehei, Aili; Tusongjiang, Mamatkeremula; Li, Cao

    2015-01-01

    The management of femoral shaft nonunion still remains a challenge in orthopaedic surgery. It represents a serious postoperative problem for the patient, associated with plate breakage and loosening, bone defect, shortening deformity and infection. A double plate fixation combined with bone grafting may become a promising therapeutic strategy for the treatment of patients with femoral shaft nonunion. In this study, our goal was to evaluate the clinical outcome of a novel approach for 14 consecutive patients with femoral shaft nonunion using double plate fixation with bone grafting. Retrospective data from June 2010 to August 2012 were obtained from records for 14 consecutive femoral shaft aseptic nonunion patients treated with double plate fixation combined with bone grafting. Nine patients were men and five patients were woman and average age of the patients was 26 years (range from 22 to 32 years). The mean time since injury was 26.2 months. The nonunion had resulted from repeated internal fixation failure (including plate or intramedullary nail fixation) in nine cases and primary internal fixation in five cases. All the 14 patients were followed up for an average of 14.8 (10-25) months. All cases achieved bony union without wound infection or fixation failure and the mean time to union was 5.2 months (range 4-7 months). Double plate fixation and bone grafting are a promising method for femoral shaft nonunion. In addition, this strategy is useful for such a nonunion caused by a repeated plate or intramedullary nail fixation failure with bone defect due to its strong stability with three-dimensional fixation and fully bone graft availability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Internal fixation of the fibula in ankle fractures: a prospective, randomized and comparative study: plating versus nailing.

    PubMed

    Asloum, Y; Bedin, B; Roger, T; Charissoux, J-L; Arnaud, J-P; Mabit, C

    2014-06-01

    Open reduction and internal plate fixation of the fibula is the gold standard treatment for ankle fractures. The aim of this study was to perform a prospective randomized study to compare bone union, complications and functional results of two types of internal fixation of the fibula (plating and the Epifisa FH intramedullary nail). Inclusion criteria were: closed fractures, isolated displaced fractures of the lateral malleolus, inter- and supra-tubercular bimalleolar fractures, and trimalleolar fractures. This study included 71 patients (mean age 53 ± 19): plate fixation group (n=35) and intramedullary nail fixation group (n=36). In seven cases, intramedullary nailing was technically impossible and was converted to plate fixation (the analysis of this sub-group was performed independently). Two patients died and two patients were lost to follow-up. The final comparative series included 32 cases of plate fixation and 28 cases of intramedullary nail fixation. Union, postoperative complications and Kitaoka and Olerud-Molander functional scores were analyzed after one year of follow-up. There was no significant difference in the rate of union (P=0.5605) between the two types of fixation. There were significantly fewer complications (7% versus 56%) and better functional scores (96 versus 82 for the Kitaoka score; 97 versus 83 for the Olerud-Molander score) with intramedullary nailing than with plate fixation. Intramedullary nailing of the lateral malleolus in non-comminuted ankle fractures without syndesmotic injury is a reproducible technique with very few complications that provides better functional results than plate fixation. II (randomized prospective study). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  9. [Advanced bone graft combined with locking compression plate for the treatment of middle and distal tibia nonunion].

    PubMed

    Zhao, Xue; Wang, Pan-feng; Zhang, Yun-tong; Zhang, Chun-cai; Xu, Shuo-gui; Zhang, Xin

    2014-12-01

    To explore methods of treating middle and distal tibia nonunion with the treatment of advanced bone graft combined with locking compression plate. From January 2011 to December 2012, 12 patients with middle and distal tibia nonunion were treated with advanced bone graft combined with locking compression plate. Among patients, there were 8 males and 4 females aged from 20 to 69 with an average of 47 years old. The time from first injuries to bone nonunion was from 9 months to 5 years, avergaed 19 months. Four cases were treated with external fixation, 6 cases were treated with plate fixation, 2 cases of 12 patients occurred broken of plate and nail. Eleven patients were non-infective bone nonunion and 1 patient was infective bone nonunion. Preoperative X-ray and CT showed all patients had sequestration and formation of ossified bone with different degrees. Operative time, blood loss, wound healing were observed, fracture healing time was evaluated by postoperative X-ray. Johner-Wruhs scoring standards was used to evaluate ankle joint function after operation at 10 months. Operative time ranged from 90 to 185 min with an average of (125.00±20.15) min; blood loss ranged from 225 to 750 ml with an average of (415.00±120.00) ml. All patients were followed up from 10 months to 2.5 years with an average of 1.5 years. Postoperative X-ray showed bone union was formed around fracture after operation at 4 months in all patients, 3 cases obtained bone healing within 6 months after operation, 9 cases obtained from 8 to 12 months. No infection, injury of nerve and vessles, and broken of plate and nail were ocurred. According to Johner-Wruhs scoring at 10 months after operation, 10 cases obtained excellent results, 1 good and 1 moderate. Advanced bone graft combined with locking compression plate, which can build fracture multi-point supporting based on full compression of bone nonunion to get effective fixation, is an effective method in treating middle and distal tibia

  10. Development of the Gliding Hole of the Dynamics Compression Plate

    NASA Astrophysics Data System (ADS)

    Salim, U. A.; Suyitno; Magetsari, R.; Mahardika, M.

    2017-02-01

    The gliding hole of the dynamics compression plate is designed to facilitate relative movement of pedicle screw during surgery application. The gliding hole shape is then geometrically complex. The gliding hole manufactured using machining processes used to employ ball-nose cutting tool. Then, production cost is expensive due to long production time. This study proposed to increase productivity of DCP products by introducing forming process (cold forming). The forming process used to involve any press tool devices. In the closed die forming press tool is designed with little allowance, then work-pieces is trapped in the mould after forming. Therefore, it is very important to determine hole geometry and dimensions of raw material in order to success on forming process. This study optimized the hole sizes with both geometry analytics and experiments. The success of the forming process was performed by increasing the holes size on the raw materials. The holes size need to be prepared is diameter of 5.5 mm with a length of 11.4 mm for the plate thickness 3 mm and diameter of 6 mm with a length of 12.5 mm for the plate thickness 4 mm.

  11. Midshaft Fractures of the Clavicle: A Meta-analysis Comparing Surgical Fixation Using Anteroinferior Plating Versus Superior Plating.

    PubMed

    Nourian, Alex; Dhaliwal, Satvinder; Vangala, Sitaram; Vezeridis, Peter S

    2017-09-01

    To compare the outcomes of clavicle fracture fixation using anteroinferior versus superior plate placement. We performed a meta-analysis of studies that have reported on outcomes after superior or anteroinferior plate fixation for acute midshaft clavicle fractures (Orthopaedic Trauma Association 15-B). A computerized literature search in the Pubmed, Scopus, and Cochrane Library databases was used to identify relevant articles. Only full text articles without language restrictions were evaluated. The inclusion criteria consisted of: (1) fracture of the midshaft clavicle; (2) surgery for acute fractures (within 1 month of the fracture); (3) adult patients (16 years of age and older); and (4) open reduction and internal fixation with plate application in either the anteroinferior or superior position. Studies were excluded if they did not specify plate location, evaluated multitrauma patients, investigated minimally invasive procedures, or studied operations for revision, nonunion, malunion, or infection. The primary measured outcomes were symptomatic hardware (implant prominence or irritation) and surgery for implant removal. The secondary outcomes were time to union, fracture union, nonunion, malunion, Disabilies of the Arm, Shoulder and Hand score, Constant score, and implant failure. Frequencies and proportions of cases were recorded for binary outcomes, whereas mean and standard deviations were recorded for continuous outcomes. Other summary statistics provided were used to impute mean and standard deviations under the assumption of normality when these were not reported. Continuous outcomes were compared between groups using linear mixed effects models, whereas binary outcomes were compared using mixed effects logistic regression models, including fixed group effects and random study effects. P-values less than 0.05 were considered statistically significant. All analyses were performed using SAS v. 9.4 (SAS Institute Inc, Cary, NC). A total of 1428 articles were

  12. Salter-Harris II forearm fracture reduction and fixation using a buttress plate.

    PubMed

    Barnes, Jonathan; Webb, Mark; v Fearon, Paul

    2014-01-31

    Distal radius fractures are common injuries in children. Those that affect the growth plate (physis) need to be managed carefully as inadequate management may lead to long-term deformity and a reduction in function. However, different management strategies all have drawbacks and controversy exists over how best to manage these cases. This is the case of a 13-year-old girl who presented with a Salter Harris II fracture, which was managed using a novel approach of utilising a T plate in a buttress mode to stabilise the fracture after anatomical reduction. This provided effective fracture fixation and should allow good bone healing without causing any iatrogenic growth plate damage and without fixing a plate across the physis, which may need removal in the future.

  13. Salter-Harris II forearm fracture reduction and fixation using a buttress plate

    PubMed Central

    Barnes, Jonathan; Webb, Mark; Fearon, Paul v

    2014-01-01

    Distal radius fractures are common injuries in children. Those that affect the growth plate (physis) need to be managed carefully as inadequate management may lead to long-term deformity and a reduction in function. However, different management strategies all have drawbacks and controversy exists over how best to manage these cases. This is the case of a 13-year-old girl who presented with a Salter Harris II fracture, which was managed using a novel approach of utilising a T plate in a buttress mode to stabilise the fracture after anatomical reduction. This provided effective fracture fixation and should allow good bone healing without causing any iatrogenic growth plate damage and without fixing a plate across the physis, which may need removal in the future. PMID:24488665

  14. Biomechanical Assessment of Locked Plating for the Fixation of Patella Fractures.

    PubMed

    Wurm, Simone; Augat, Peter; Bühren, Volker

    2015-09-01

    To analyze the mechanical stability of locked plating in comparison with tension-band wiring for the fixation of fractures of the patella. Biomechanical tests were performed on artificial foam patella specimens comparing an angular stable plate and monocortical screws with tension-band wiring. Tests were performed under combined tension and bending until failure simulating physiological loading of the tibia during walking. Tension-band wiring failed at 66% of the failure load of plating (1052 N, P = 0.002) and had 5 times larger fracture gap displacements (P = 0.002). Based on the biomechanical advantages, locked plating of the patella may constitute a reasonable alternative in the treatment of patella fractures.

  15. The use of short carbon fibre reinforced thermoplastic plates for fracture fixation.

    PubMed

    Gillett, N; Brown, S A; Dumbleton, J H; Pool, R P

    1985-03-01

    Thermoplastic plates of Nylon 6-10 and Polybutylene terephthalate reinforced with 30% short randomly oriented carbon fibres were tested for internal fixation of canine femoral transverse midshaft fractures. The elastic modulus of the plates was one-half that of bone: however, ultimate strength and strain in bending were comparable to bone. The fractures healed with moderate callus formation which was completely remodelled by 8 to 12 wk post surgery. Although a moderate inflammatory reaction to occasional particulate debris was noted, the materials appeared to possess the proper elastic moduli to allow sufficient support for the healing fracture without protecting the remodelling process.

  16. Biomechanical comparison of supraacetabular external fixation and anterior pelvic bridge plating.

    PubMed

    Çavuşoğlu, Ali Turgay; Erbay, Fatma Kübra; Özsoy, Mehmet Hakan; Demir, Teyfik

    2017-10-01

    Unstable pelvic ring injuries are complex and risky injuries due to high morbidity and mortality. Although anterior pelvic external fixator is a suitable method for rapid stabilization of an injured pelvic ring, due to some disadvantages such as high complication rate, nerve damage, and difficulties of patient's mobility and comfort, there has recently been increased searching for alternative methods for stabilization of the pelvic ring. Pubic symphysis zone freely moves in pelvic models. This study aims to evaluate the biomechanical stability of anterior pelvic bridge plating and compare it with supraacetabular external fixators in an untreated unstable pelvic fracture model. Samples were loaded statically with 2-mm/min loading rate in single leg standing position. Maximum load was 2.3 kN. When loading the samples, photographs were taken continuously. Stiffness values were calculated from the load displacement curves. Some reference parameters were described and were measured from unloaded and 2.3-kN-loaded photographs of the test. The mean stiffness values were 491.14 ± 52.22, 478.55 ± 41.44, and 470.25 ± 44.51 N/mm for anterior pelvic bridge plating group, supraacetabular external fixator group, and Control group, respectively. According to the measured parameters from photographs, the mean displacement at the pubic symphysis was 4.7 ± 0.32, 15.8 ± 2.01, and 18.2 ± 0.47 mm for anterior pelvic bridge plating, supraacetabular external fixator, and Control group, respectively. The highest displacement in the pubic symphysis was found in Control group, and minimum displacement was observed in anterior pelvic bridge plating group. When the perpendicular distance between the right and left lower end of ischium was examined, it was observed that displacement was minimum in anterior pelvic bridge plating group compared to other two groups, regarding to the high stability of pubic symphysis. In conclusion, this study revealed

  17. Human fixation detection model in video compressed domain based on Markov random field

    NASA Astrophysics Data System (ADS)

    Li, Yongjun; Li, Yunsong; Liu, Weijia; Hu, Jing; Ge, Chiru

    2017-01-01

    Recently, research on and applications of human fixation detection in video compressed domain have gained increasing attention. However, prediction accuracy and computational complexity still remain a challenge. This paper addresses the problem of compressed domain fixations detection in the videos based on residual discrete cosine transform coefficients norm (RDCN) and Markov random field (MRF). RDCN feature is directly extracted from the compressed video with partial decoding and is normalized. After spatial-temporal filtering, the normalized map [Smoothed RDCN (SRDCN) map] is taken to the MRF model, and the optimal binary label map is obtained. Based on the label map and the center saliency map, saliency enhancement and nonsaliency inhibition are done for the SRDCN map, and the final SRDCN-MRF salient map is obtained. Compared with the similar models, we enhance the available energy functions and introduce an energy function that indicates the positional information of the saliency. The procedure is advantageous for improving prediction accuracy and reducing computational complexity. The validation and comparison are made by several accuracy metrics on two ground truth datasets. Experimental results show that the proposed saliency detection model achieves superior performances over several state-of-the-art compressed-domain and pixel-domain algorithms on evaluation metrics. Computationally, our algorithm reduces 26% more computational complexity with comparison to similar algorithms.

  18. Comparison of cannulated screws versus compression staples for subtalar arthrodesis fixation.

    PubMed

    Herrera-Pérez, Mario; Andarcia-Bañuelos, Cesar; Barg, Alexej; Wiewiorski, Martin; Valderrabano, Victor; Kapron, Ashley L; De Bergua-Domingo, Josep Maria; Pais-Brito, Jose Luis

    2015-02-01

    Different fixation techniques have been described in the literature for isolated subtalar arthrodesis (ISA). The purpose of this study was to compare the fusion rate and clinical outcome of ISA using cannulated compression screws or compression staples. Thirty-three patients (33 feet) underwent ISA using screw (17 feet) or staples (16 feet) fixation. Patients were followed for 42.7 ± 16.4 months (range, 24.5-84.3 months). The subtalar fusion was assessed radiographically and clinically. Clinical outcome measures included the visual analog scale (VAS) for pain and American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score. The average pain score decreased significantly from 6.4 ± 1.1 (range, 5-9) to 0.8 ± 1.3 (range, 0-4) (P < .001). In the screws group, the average AOFAS hindfoot score increased significantly from 54.6 ± 8.8 (range, 37-67) preoperatively to 86.1 ± 7.1 (range, 71-91) postoperatively (P < .001). In the staples group, the average AOFAS hindfoot score increased significantly from 53.4 ± 11.1 (range, 33-69) preoperatively to 83.4 ± 6.9 (range, 71-91) postoperatively (P < .001). The AOFAS hindfoot score was comparable in both groups (P = .149). Only the AOFAS hindfoot score function subgroup in the screw fixation was significantly higher than in the staples fixation group (P = .005). There were 4 cases of nonunion at the site of subtalar arthrodesis (2 from screws group, 2 from staples group). The complication rate was comparable in both groups. The fusion rate was comparable in both groups, while the postoperative functional outcome was significantly better in the screw fixation group. Level III, retrospective comparative cohort study. © The Author(s) 2014.

  19. Plating versus intramedullary fixation for mid-shaft clavicle fractures: a systemic review and meta-analysis.

    PubMed

    Gao, Yan; Chen, Wei; Liu, Yue-Jv; Li, Xu; Wang, Hai-Li; Chen, Zhao-Yu

    2016-01-01

    Background. Plate fixation and intramedullary fixation are the most commonly used surgical treatment options for mid-shaft clavicle fractures; the latter method has demonstrated better performance in some studies. Objectives. Our aim was to critically review and summarize the literature comparing the outcomes of mid-shaft clavicle fracture treatment with plate fixation or intramedullary fixation to identify the better approach. Search Methods. Potential academic articles were identified from the Cochrane Library, MEDLINE (1966-2015.5), PubMed (1966-2015.5), EMBASE (1980-2015.5) and ScienceDirect (1966-2015.5). Gray studies were identified from the references of the included literature. Selection Criteria. Randomized controlled trials (RCTs) and non-RCTs comparing plate fixation and intramedullary fixation for mid-shaft clavicle fracture were included. Data Collection and Analysis. Two reviewers performed independent data abstraction. The I (2) statistic was used to assess heterogeneity. A fixed- or random-effects model was used for the meta-analysis. Results. Six RCTs and nine non-RCTs were retrieved, including 513 patients in the intramedullary fixation group and 521 patients in the plating group. No significant differences in terms of the union rate and shoulder function were found between the groups. Patients in the intramedullary fixation group had a shorter operative time, less blood loss, smaller wound size, and shorter union time than those in the plating group. With respect to complications, significant differences were identified for all complications and major complications (wound infection, nonunion, implant failures, transient brachial plexopathy, and pain after 6 months). Similar secondary complications (symptomatic hardware, hardware irritation, prominence, numbness, hypertrophic callus) were observed in both groups. Conclusions. Intramedullary fixation may be superior to plate fixation in the treatment of mid-shaft clavicle fractures, with similar

  20. Effect of interfragmentary gap on compression force in a headless compression screw used for scaphoid fixation.

    PubMed

    Tan, E S; Mat Jais, I S; Abdul Rahim, S; Tay, S C

    2017-04-01

    We investigated the effect of an interfragmentary gap on the final compression force using the Acutrak 2 Mini headless compression screw (length 26 mm) (Acumed, Hillsboro, OR, USA). Two blocks of solid rigid polyurethane foam in a custom jig were separated by spacers of varying thickness (1.0, 1.5, 2.0 and 2.5 mm) to simulate an interfragmentary gap. The spacers were removed before full insertion of the screw and the compression force was measured when the screw was buried 2 mm below the surface of the upper block. Gaps of 1.5 mm and 2.0 mm resulted in significantly decreased compression forces, whereas there was no significant decrease in compression force with a gap of 1 mm. An interfragmentary gap of 2.5 mm did not result in any contact between blocks. We conclude that an increased interfragmentary gap leads to decreased compression force with this screw, which may have implications on fracture healing.

  1. The calcar screw in angular stable plate fixation of proximal humeral fractures - a case study

    PubMed Central

    2011-01-01

    Background With new minimally-invasive approaches for angular stable plate fixation of proximal humeral fractures, the need for the placement of oblique inferomedial screws ('calcar screw') has increasingly been discussed. The purpose of this study was to investigate the influence of calcar screws on secondary loss of reduction and on the occurrence of complications. Methods Patients with a proximal humeral fracture who underwent angular stable plate fixation between 01/2007 and 07/2009 were included. On AP views of the shoulder, the difference in height between humeral head and the proximal end of the plate were determined postoperatively and at follow-up. Additionally, the occurrence of complications was documented. Patients with calcar screws were assigned to group C+, patients without to group C-. Results Follow-up was possible in 60 patients (C+ 6.7 ± 5.6 M/C- 5.0 ± 2.8 M). Humeral head necrosis occurred in 6 (C+, 15.4%) and 3 (C-, 14.3%) cases. Cut-out of the proximal screws was observed in 3 (C+, 7.7%) and 1 (C-, 4.8%) cases. In each group, 1 patient showed delayed union. Implant failure or lesions of the axillary nerve were not observed. In 44 patients, true AP and Neer views were available to measure the head-plate distance. There was a significant loss of reduction in group C- (2.56 ± 2.65 mm) compared to C+ (0.77 ± 1.44 mm; p = 0.01). Conclusions The placement of calcar screws in the angular stable plate fixation of proximal humeral fractures is associated with less secondary loss of reduction by providing inferomedial support. An increased risk for complications could not be shown. PMID:21943090

  2. Use of self-tapping metal screws for temporary fixation of a resorbable plate system in maxillofacial surgery.

    PubMed

    Iwai, Toshinori; Omura, Susumu; Aoki, Noriaki; Tohnai, Iwai

    2015-05-01

    Resorbable plate systems have been used in maxillofacial surgery to obviate the need for plate removal. However, resorbable plates and screws are very costly, and refixation with additional screws may be necessary when reduction or repositioning of the bone segment is inaccurate. Here we report the use of self-tapping metal screws for temporary fixation of a resorbable plating system in maxillofacial surgery to avoid the use of additional screws following inaccurate fixation or the reuse of resorbable screws, which may result in loosening.

  3. Morphological analysis of acromion and hook plate for the fixation of acromioclavicular joint dislocation.

    PubMed

    Yoon, Jong Pil; Lee, Yeon Soo; Song, Geun Soo; Oh, Joo Han

    2017-03-01

    Acromioclavicular (AC) joint dislocation is a common sports injury. Hook plate fixation is currently widely used to treat this injury, as it can promote the natural healing of the ligament with good clinical outcomes. However, subacromial erosion and impingement are frequently observed post-operatively. It was hypothesized that the morphology and the contact characteristics between the hook portion and the acromion are the main causes of complications after hook plate fixation with the currently available commercial designs. Three-dimensional reconstructed models of the AC joint obtained from the computed tomographic scans of 23 male and 23 female patients (mean age, 61.1 ± 6.3 years) were evaluated, and multiple anatomical parameters were measured. For the subacromial positioning of the hook plate, an actual hook plate (Synthes Inc., West Chester, PA, USA) was scanned, and the contact between the hook plate and the acromion was estimated. The thicknesses of the acromion and distal clavicle were 9.7 ± 1.5 mm (10.7 mm in men; 8.6 mm in women) and 11.3 ± 1.6 mm (11.6 mm in men; 10.0 mm in women), respectively. The width of the acromion was 28.5 ± 3.6 mm. The mean inclination angle between the hook plate and the acromion was 29.3° ± 9.7° (27.9° in men; 30.6° in women). The hook plate made a point contact with the acromion at 9.2 ± 3.3 mm (31.5 %) from the lateral end of the acromion. The results revealed that the hook made a pinpoint contact with the undersurface of the acromion, and this might explain why complications commonly occur after hook plate fixation. The force concentration phenomenon associated with the hook plate of existing designs results from cases of morphological mismatch, such as excessive inclination and improper occupation of the subacromial space.

  4. Contact problems for a circular plate with sliding fixation at the end face

    NASA Astrophysics Data System (ADS)

    Bazarenko, N. A.

    2014-05-01

    Two mixed elasticity problems of punch indentation into a circular plate placed without clearance in a rigid cylindrical holder with smooth walls are considered. In the first problem, the plate lies without friction on a rigid base, and in the second problem, the plate is rigidly fixed to the base. The problems are solved by a method that was developed for bodies of finite dimensions and is based on the properties of closed systems of orthogonal functions. Each of the problems is reduced to two integral equations, namely, a Volterra integral equation of the first kind for the contact pressure function and a Fredholm integral equation of the first kind for the derivatives of the displacement of the plate upper surface outside the punch. The displacement function is sought as the sum of a trigonometric series and a power function with a root singularity. After truncation, the obtained illposed system of linear algebraic equation has a stable solution. A method for solving Volterra integral equations is given. The contact pressure distribution function and the dimensionless indentation force are determined. Examples of calculation of the plate interaction with the plane punch are given. Contact problems were earlier studied for a rectangle and a circular plate with a stress-free end both without taking account of their fixation [1, 2] and with regard for their fixation [3, 4]. The solution method described here was used to study the interaction of elastic hollow cylinder of finite length with a rigid bandage and a rigid insert [5, 6]. Other papers dealing with contact problems for bodies of finite dimensions, in particular, for a circular plate, should also be mentioned. In these papers, the problems under study were solved by the method of homogeneous solutions [7, 8] and by the method of coupled series-equations [9].

  5. Assessment of Intra-articular Screw Penetration During Radial Head and Olecranon Locking Plate Fixation

    PubMed Central

    Dizdarevic, Ismar; Eden, Claire M.; Bengard, Matthew; Barron, O. Alton; Catalano, Louis W.; Glickel, Steven Z.

    2016-01-01

    Background: The purpose of this study is to evaluate the role of radiographic and clinical exams in predicting screw penetration into the proximal radioulnar joint and ulnohumeral joint during open reduction and internal fixation of the radial head and proximal ulna. Methods: Olecranon and radial head plates were applied to 15 cadaveric elbows. Screws were assessed for intra-articular joint penetration using both clinical exam and radiographic evaluation. Clinical exam consisted of evaluation for crepitus. Radiographs demonstrating screws positioned near the joint surface were evaluated for penetration by 3 fellowship trained hand surgeons. Elbows were disarticulated and screw prominence was determined and recorded using standardized calipers. The ability of clinical and radiographic exams to correctly predict a breach in the articular surface was determined by calculating sensitivity, specificity, and predictive values. Consideration was given to screw position. Results: The sensitivity of crepitus was 81.1% for screws in the radial head plate and 72.6% for screws in the olecranon plate. The sensitivity of radiographs was 72.4% for the screws in the radial head plate and 55.0% for screws in the olecranon plate. Correct radiographic assessment of penetration varied but position o-2 on the olecranon plate consistently resulted in the lowest sensitivity of 30.3%. Conclusions: The study evaluates sensitivity and specificity of clinical and radiographic means when assessing for articular penetration of screws during olecranon and radial head locking plate fixation. Certain screw locations are more difficult to evaluate than others and may go undetected by standard means of assessment used in a surgical setting. PMID:27418892

  6. [Laryngeal Tube Position Shift after Chest Compression: Comparison of Fixation Methods Using Durapore Tape, Multipore Tape, or a Neck Tape].

    PubMed

    Seno, Hisayo; Komasawa, Nobuyasu; Fujiwara, Shunsuke; Miyazaki, Shinichiro; Tatsumi, Shinichi; Minami, Toshiaki

    2015-05-01

    The laryngeal tube (LT ; Smiths Medical, Minnesota, U. S. A) is an inflatable supraglottic device for emergency airway management such as during chest compression, the instability after insertion remains a problem. We investigated the effectiveness of three fixation methods of LT using a manikin and automated chest compressor. After 10-minute chest compression, LT without fixation was shifted by 0.4 ± 0.1 cm, which was greater than with Durapore tape (0.2 ± 0.1 cm), Multipore tape (0.2 ± 0.1 cm), or a neck tape (0.1 ± 0.1 cm). The shift of the position was smaller with neck tape fixation compared to Durapore or Multipore tape fixation. A fixation neck tape may be useful in stabilizing the inserted position of LT during cardiopulmonary resuscitation.

  7. [Treatment of type C3 distal femoral fractures with double-plating fixation via anteriormiddle approach].

    PubMed

    Zhang, Zhi-Min; Liu, Jian; Huang, Chun-Xia; Zhao, Zhan-Fu; Wang, Gang; Qin, Cong-Cong

    2012-12-01

    To investigate clinical efficacy and feasibility of double-plating fixation via anteriormiddle approach in treating type C3 distal femoral fractures. From August 2008 to August 2011, 12 cases with type C3 distal femoral fractures were treated, including 5 open fractures and 7 closed fractures. Among them, there were 8 males, 4 females with an average of 40 years (ranged, 25 to 55 years). There were 7 in left side, 5 in right side. Nine cases were caused by car accident, 3 cases by falling down. The duration from injury to hospital was form 20 minutes to 5 days (mean 135 min). After tibia bone traction for 5 to 8 days, the operation were performed by double-plating fixation via anteriormiddle approach, and autograft of iliac bone or allograft bone grafting were given to bone defect. Knee joint function was evaluated according to Merchanetal criteria. The operation time was from 110 to 160 min, with an average of 135 min, the blood loss was from 300 ml to 500 ml,with an average of 400 ml. Post-operative wound were stage I healing. All patients were followed up from 16 to 36 months (mean 24 months). No infection, reduction loss, nonunion, deep vein thrombosis occurred. Bone healing time was for 18 to 24 weeks with an average of 21 weeks. According to the Merchanetal criteria, 4 cases got excellent results, 6 good, 1 fair and 1 poor. Double-plating fixation via anteriormiddle approach for type C3 distal femoral fractures is an effective way, which has advantages of obvious exposure, simple manipulation, anatomical reduction, stable fixation. However,operation indications and operating instructions should be strictly followed.

  8. Are chest compressions safe for the patient reconstructed with sternal plates? Evaluating the safety of cardiopulmonary resuscitation using a human cadaveric model

    PubMed Central

    2010-01-01

    Background Plate and screw fixation is a recent addition to the sternal wound treatment armamentarium. Patients undergoing cardiac and major vascular surgery have a higher risk of postoperative arrest than other elective patients. Those who undergo sternotomy for either cardiac or major vascular procedures are at a higher risk of postoperative arrest. Sternal plate design allows quick access to the mediastinum facilitating open cardiac massage, but chest compressions are the mainstay of re-establishing cardiac output in the event of arrest. The response of sternal plates and the chest wall to compressions when plated has not been studied. The safety of performing this maneuver is unknown. This study intends to demonstrate compressions are safe after sternal plating. Methods We investigated the effect of chest compressions on the plated sternum using a human cadaveric model. Cadavers were plated, an arrest was simulated, and an experienced physician performed a simulated resuscitation. Intrathoracic pressure was monitored throughout to ensure the plates encountered an appropriate degree of force. The hardware and viscera were evaluated for failure and trauma respectively. Results No hardware failure or obvious visceral trauma was observed. Rib fractures beyond the boundaries of the plates were noted but the incidence was comparable to control and to the fracture incidence after resuscitation previously cited in the literature. Conclusions From this work we believe chest compressions are safe for the patient with sternal plates when proper plating technique is used. We advocate the use of this life-saving maneuver as part of an ACLS resuscitation in the event of an arrest for rapidly re-establishing circulation. PMID:20718981

  9. Simplified laser-driven flyer plates for shock compression science

    NASA Astrophysics Data System (ADS)

    Brown, Kathryn E.; Shaw, William L.; Zheng, Xianxu; Dlott, Dana D.

    2012-10-01

    We describe a simplified system of laser-driven flyer plates for shock compression science and shock spectroscopy. We used commercially available one-box Nd:YAG lasers and beam homogenization solutions to create two launch systems, one based on a smaller (400 mJ) YAG laser and an inexpensive diffusive optic, and one based on a larger (2500 mJ) laser and a diffractive beam homogenizer. The flyer launch, flight, and impact processes were characterized by an 8 GHz fiberoptic photon Doppler velocimeter. We investigated effects of different substrates, adhesives, absorbers, ablative layers, and punching out disks from continuous foils versus fabricating individual foil disks, and found that a simple metal foil epoxied to a glass window was satisfactory in almost all cases. Our simplified system launched flyer plates with velocities up to 4.5 km s-1 and kinetic energies up to 250 mJ that can drive sustained steady shocks for up to 25 ns. The factor that limits these velocities and energies is the laser fluence that can be transmitted through the glass substrate to the flyer surface without optical damage. Methods to increase this transmission are discussed. Reproducible flyer launches were demonstrated with velocity variations of 0.06% and impact time variations of 1 ns. The usefulness of this flyer plate system is demonstrated by Hugoniot equation of state measurements of a polymer film, emission spectroscopy of a dye embedded in the polymer, and impact initiation and emission spectroscopy of a reactive material consisting of nanoscopic fuel and oxidizer particles.

  10. Simplified laser-driven flyer plates for shock compression science.

    PubMed

    Brown, Kathryn E; Shaw, William L; Zheng, Xianxu; Dlott, Dana D

    2012-10-01

    We describe a simplified system of laser-driven flyer plates for shock compression science and shock spectroscopy. We used commercially available one-box Nd:YAG lasers and beam homogenization solutions to create two launch systems, one based on a smaller (400 mJ) YAG laser and an inexpensive diffusive optic, and one based on a larger (2500 mJ) laser and a diffractive beam homogenizer. The flyer launch, flight, and impact processes were characterized by an 8 GHz fiberoptic photon Doppler velocimeter. We investigated effects of different substrates, adhesives, absorbers, ablative layers, and punching out disks from continuous foils versus fabricating individual foil disks, and found that a simple metal foil epoxied to a glass window was satisfactory in almost all cases. Our simplified system launched flyer plates with velocities up to 4.5 km s(-1) and kinetic energies up to 250 mJ that can drive sustained steady shocks for up to 25 ns. The factor that limits these velocities and energies is the laser fluence that can be transmitted through the glass substrate to the flyer surface without optical damage. Methods to increase this transmission are discussed. Reproducible flyer launches were demonstrated with velocity variations of 0.06% and impact time variations of 1 ns. The usefulness of this flyer plate system is demonstrated by Hugoniot equation of state measurements of a polymer film, emission spectroscopy of a dye embedded in the polymer, and impact initiation and emission spectroscopy of a reactive material consisting of nanoscopic fuel and oxidizer particles.

  11. Simplified laser-driven flyer plates for shock compression science

    SciTech Connect

    Brown, Kathryn E.; Shaw, William L.; Zheng Xianxu; Dlott, Dana D.

    2012-10-15

    We describe a simplified system of laser-driven flyer plates for shock compression science and shock spectroscopy. We used commercially available one-box Nd:YAG lasers and beam homogenization solutions to create two launch systems, one based on a smaller (400 mJ) YAG laser and an inexpensive diffusive optic, and one based on a larger (2500 mJ) laser and a diffractive beam homogenizer. The flyer launch, flight, and impact processes were characterized by an 8 GHz fiberoptic photon Doppler velocimeter. We investigated effects of different substrates, adhesives, absorbers, ablative layers, and punching out disks from continuous foils versus fabricating individual foil disks, and found that a simple metal foil epoxied to a glass window was satisfactory in almost all cases. Our simplified system launched flyer plates with velocities up to 4.5 km s{sup -1} and kinetic energies up to 250 mJ that can drive sustained steady shocks for up to 25 ns. The factor that limits these velocities and energies is the laser fluence that can be transmitted through the glass substrate to the flyer surface without optical damage. Methods to increase this transmission are discussed. Reproducible flyer launches were demonstrated with velocity variations of 0.06% and impact time variations of 1 ns. The usefulness of this flyer plate system is demonstrated by Hugoniot equation of state measurements of a polymer film, emission spectroscopy of a dye embedded in the polymer, and impact initiation and emission spectroscopy of a reactive material consisting of nanoscopic fuel and oxidizer particles.

  12. Biomechanical investigation of an alternative concept to angular stable plating using conventional fixation hardware

    PubMed Central

    2010-01-01

    Background Angle-stable locking plates have improved the surgical management of fractures. However, locking implants are costly and removal can be difficult. The aim of this in vitro study was to evaluate the biomechanical performance of a newly proposed crossed-screw concept ("Fence") utilizing conventional (non-locked) implants in comparison to conventional LC-DCP (limited contact dynamic compression plate) and LCP (locking compression plate) stabilization, in a human cadaveric diaphyseal gap model. Methods In eight pairs of human cadaveric femora, one femur per pair was randomly assigned to receive a Fence construct with either elevated or non-elevated plate, while the contralateral femur received either an LCP or LC-DCP instrumentation. Fracture gap motion and fatigue performance under cyclic loading was evaluated successively in axial compression and in torsion. Results were statistically compared in a pairwise setting. Results The elevated Fence constructs allowed significantly higher gap motion compared to the LCP instrumentations (axial compression: p ≤ 0.011, torsion p ≤ 0.015) but revealed similar performance under cyclic loading (p = 0.43). The Fence instrumentation with established bone-plate contact revealed larger fracture gap motion under axial compression compared to the conventional LC-DCP osteosynthesis (p ≤ 0.017). However, all contact Fence specimens survived the cyclic test, whereas all LC-DCP constructs failed early during torsion testing (p < 0.001). All failures occurred due to breakage of the screw heads. Conclusions Even though accentuated fracture gap motion became obvious, the "Fence" technique is considered an alternative to cost-intensive locking-head devices. The concept can be of interest in cases were angle-stable implants are unavailable and can lead to new strategies in implant design. PMID:20492707

  13. Comparison of outcome of tibial plafond fractures managed by hybrid external fixation versus two-stage management with final plate fixation

    PubMed Central

    Cisneros, Luis Natera; Gómez, Mireia; Alvarez, Carlos; Millán, Angélica; De Caso, Julio; Soria, Laura

    2016-01-01

    Background: Tibial platfond fractures are usually associated with massive swelling of the foot and ankle, as well as with open wounds. This swelling may cause significant decrease of the blood flow, so the state of the soft tissue is determinant for the surgical indication and the type of implant. This retrospective study compares the union times in cases of tibial plafond fractures managed with a hybrid external fixation as a definitive procedure versus those managed with a two stage strategy with final plate fixation. Materials and Methods: A retrospective study in a polytrauma referral hospital was performed between 2005 and 2011. Patients with a tibial plafond fracture, managed with a hybrid external fixation as a definitive procedure or managed with a two stage strategy with the final plate fixation were included in the study. Postoperative radiographs were evaluated by two senior surgeons. Fracture healing was defined as callus bridging of one cortex, seen on both lateral and anteroposterior X-ray. The clinical outcome was evaluated by means of 11 points Numerical Rating Scale for pain and The American Orthopedic Foot and Ankle Society ankle score, assessed at the last followup visit. Thirteen patients had been managed with a hybrid external fixation and 18 with a two-stage strategy with the final plate fixation. There were 14 males and 17 females with a mean age of 48 years (range 19–82 years). The mean followup was 24 months (range 24–70 months). Results: The mean time from surgery to weight bearing was 7 ± 6.36 days for the hybrid fixation group and 57.43 ± 15.46 days for the plate fixation group (P < 0.0001); and the mean time from fracture to radiological union was 133.82 ± 37.83) and 152.8 ± 72.33 days respectively (P = 0.560). Conclusion: Besides the differences between groups regarding the baseline characteristics of patients, the results of this study suggest that in cases of tibial plafond fractures, the management with a hybrid external

  14. Fixation of Intertrochanteric Valgus Osteotomy with T Plate in Treatment of Developmental Coxa Vara

    PubMed Central

    Khairy, Hosam Mohamed

    2016-01-01

    Background Although the valgus subtrochanteric osteotomy is considered as a standard surgical treatment for coxa vara, there is no consensus on the optimal method of fixation and osteotomy technique. Fixation of the osteotomy has been achieved by various methods including external fixation and internal fixation with pins and cerclage and a variety of plates. The aim of this study is the evaluation of the results of developmental coxa treated by Y intertrochanteric valgus osteotomy fixed with a T-buttress plate compared with other methods of fixation in the literature. Methods Eighteen corrective valgus intertrochanteric femoral osteotomies were performed in 18 patients (18 hips) for treatment of unilateral developmental coxa vara deformity and fixed with a T plate. There were 12 males and 6 females. The right hip was affected in 10 patients and the left hip in 8 patients. Clinically, patients were evaluated by Larson hip score. Radiographically, anteroposterior view of the pelvis and frog leg lateral views of the affected hip were taken preoperatively and compared with the findings at the final follow-up. Results The average follow-up was 29 months (range, 24 to 36 months). Clinical results showed improvement of the mean Larson hip score from 57.8 to 97.0 (p < 0.001). Radiological results showed that all osteotomies were completely united in 2.4 months (range, 2 to 3 months) with the achievement of the planned correction angle. The average correction of Hilgenreiner's epiphyseal angle improved from 78.2° to 27.8° (p < 0.001) at the final follow-up. The femoral neck shaft angle was improved from 93.7° to 129.9° (p < 0.001) at the final follow-up. Shortening of the affected limb was corrected from 2.8 cm to 1.3 cm (p < 0.001) at the last follow-up. No major serious complications were recorded in the present study. Conclusions Intertrochanteric valgus osteotomy of the proximal femur fixed with a T plate may be efficient for treatment of developmental coxa vara

  15. Locking plate fixation of distal femoral fractures is a challenging technique: a retrospective review

    PubMed Central

    Toro, Giuseppe; Calabrò, Giampiero; Toro, Antonio; de Sire, Alessandro; Iolascon, Giovanni

    2015-01-01

    Summary Distal femoral fractures have typically a bimodal occurrence: in young people due to a high-energy trauma and in older people related to a low-energy trauma. These fractures are associated to a very high morbidity and mortality in elderly. Distal femoral fractures might be treated with plates, intramedullary nails, external fixations, and prosthesis. However, difficulties in fracture healing and the rate of complications are important clinical issues. The purpose of this retrospective review was to present our experience in treatment of distal femoral fracture in a sample of older people in order to evaluate the technical pitfalls and strategies used to face up the fractures unsuccessfully treated with locking plates. We included people aged more than 65 years, with a diagnosis of distal femoral fracture, treated with locking plates. We considered ‘unsuccessfully treated’ the cases with healing problems or hardware failures. Of the 12 patients (9 females and 3 males; mean aged 68.75 ± 3.31 years) included, we observed 3 ‘unsuccessfully cases’, 2 due to nonunions and 1 due to an early hardware failure, all treated using a condylar blade plate with a bone graft. One patient obtained a complete fracture healing after 1 year and in the other cases there was a nonunion. We observed as most common technical pitfalls: inadequate plate lengthening, fracture bridging, and number of locking screws. The use of locking plates is an emerging technique to treat these fractures but it seems more challenging than expected. In literature there is a lack of evidences about the surgical management of distal femoral fractures that is still an important challenge for the orthopaedic surgeon that has to be able to use all the fixation devices available. PMID:27134634

  16. Effect of plate working length on plate stiffness and cyclic fatigue life in a cadaveric femoral fracture gap model stabilized with a 12-hole 2.4 mm locking compression plate

    PubMed Central

    2013-01-01

    Background There are several factors that can affect the fatigue life of a bone plate, including the mechanical properties of the plate and the complexity of the fracture. The position of the screws can influence construct stiffness, plate strain and cyclic fatigue of the implants. Studies have not investigated these variables in implants utilized for long bone fracture fixation in dogs and cats. The purpose of the present study was to evaluate the effect of plate working length on construct stiffness, gap motion and resistance to cyclic fatigue of dog femora with a simulated fracture gap stabilized using a 12-hole 2.4 mm locking compression plates (LCP). Femora were plated with 12-hole 2.4 mm LCP using 2 screws per fracture segment (long working length group) or with 12-hole 2.4 mm LCP using 5 screws per fracture segment (a short working length group). Results Construct stiffness did not differ significantly between stabilization techniques. Implant failure did not occur in any of the plated femora during cycling. Mean ± SD yield load at failure in the short plate working length group was significantly higher than in the long plate working length group. Conclusion In a femoral fracture gap model stabilized with a 2.4 mm LCP applied in contact with the bone, plate working length had no effect on stiffness, gap motion and resistance to fatigue. The short plate working length constructs failed at higher loads; however, yield loads for both the short and long plate working length constructs were within physiologic range. PMID:23800317

  17. [Unstable thorax fixation with bioabsorbable plates and screws. Presentation of some cases].

    PubMed

    Nolasco-de la Rosa, Ana Lilia; Mosiñoz-Montes, Roberto; Matehuala-García, Jesús; Román-Guzmán, Edgardo; Quero-Sandoval, Fidel; Reyes-Miranda, Alma Lorena

    2015-01-01

    Flail chest is managed with mechanical ventilation or inhalation therapy, and analgesia. Mechanical ventilations carry risks by themselves and disengage with the external fixators so they must be operated to improve lung ventilatory mechanics and cleaning. Little has been published on the use of bioabsorbable material and its evolution in the setting of flail chest. A material that did had to be retired, that presented the malleability of titanium and its inflammatory reaction was minimal and could be handled in both adults and children was investigated. Here is shown a descriptive study of patients with flail chest under rib fixation with plates and bioabsorbable screws. 18 cases are presented, aged 33-74 years, three with bilateral flail chest; fixation was performed between days 1-21 of the accident. In cases that showed no fractures pelvic limbs, gait next day restarted fi ng in all cases improved mechanical ventilation, pain decreased, none has so far presented reaction material. Flail chest has a high (16.3%) mortality when no management provides the pathophysiology of the condition (pain, poor mechanical ventilation, alveolar edema-pulmonary contusion). The use of bioabsorbable material has no side effects attributable to material which is another option for rib fixation. Copyright © 2015. Published by Masson Doyma México S.A.

  18. Enhancing fixation strength in periprosthetic femur fractures by orthogonal plating-A biomechanical study.

    PubMed

    Lenz, Mark; Stoffel, Karl; Gueorguiev, Boyko; Klos, Kajetan; Kielstein, Heike; Hofmann, Gunther O

    2016-04-01

    Orthogonal plate osteosynthesis enhances fixation stability in periprosthetic femur fractures. Another option are locking attachment plates (LAP) allowing bicortical locking screw placement lateral to the prosthesis stem. Stability of lateral plate osteosynthesis with two LAP (2LAP) was compared to anterolateral orthogonal plate osteosynthesis (OP) with one LAP in a periprosthetic femur fracture model. In six pairs of fresh frozen human femora with cemented Charnley hip prosthesis, a transverse osteotomy was set distal to the tip of the prosthesis simulating a Vancouver type B1 fracture. Each pair was instrumented using a plate tensioner with either one lateral plate and two LAP, or two orthogonal anterolateral plates and one LAP. Stiffness was determined in a four-point-bending test prior to cyclic testing (2Hz) with physiologic profile and progressively increasing load up to catastrophic construct failure. Paired t-test and Wilcoxon-signed-rank test were used for statistical evaluation at a level of significance p = 0.05. The OP construct exhibited a significantly higher number of cycles and load to failure (39,627 cycles ± 4,056; 4,463 N ± 906) compared to the 2LAP construct (32,927 cycles ± 3,487; 3,793 N ± 849), p < 0.01. Mediolateral bending and torsional stiffness of the OP (1610 N/mm ± 249; 16.9 Nm/mm ± 6.3) were significantly higher compared to 2 LAP (1077 N/mm ± 189; 12.1 Nm/mm ± 3.9), p = 0.03 for both comparisons. Orthogonal plate osteosynthesis is a valuable option in periprosthetic fracture surgery, offering increased stability compared to a single lateral plate fixed with two LAP.

  19. Number and locations of screw fixation for volar fixed-angle plating of distal radius fractures: biomechanical study.

    PubMed

    Mehling, Isabella; Müller, Lars P; Delinsky, Katharina; Mehler, Dorothea; Burkhart, Klaus J; Rommens, Pol M

    2010-06-01

    To compare the biomechanical properties of different numbers and locations of screws in a multidirectional volar fixed-angle plate in a distal radius osteotomy cadaver model. We created an extra-articular fracture in 16 pairs of fresh-frozen human cadaver radiuses. The 32 specimens were randomized into 4 groups. All fractures were fixated with a multidirectional volar fixed-angle plate. We tested 4 different screw-placement options in the distal fragment. The distal fragment was fixed with 4 locking screws in the distal row of the plate in group a, and with 4 locking screws alternately in the distal and proximal rows in group b. In group c, 3 locking screws were used in the proximal row; in group d, 7 locking screws were used, filling all screw holes in the distal and proximal rows of the plate. The proximal fragment was fixed with 3 screws. The specimens were loaded with 80 N under dorsal and volar bending and with 250 N axial loading. Finally, load to failure tests were performed. Group d had the highest mean stiffness, 429 N/mm under axial compression, and was statistically significantly stiffer than the other groups. Group b had a mean stiffness of 208 N/mm, followed by group a, with 177 N/mm. Group c showed only a mean stiffness of 83 N/mm under axial compression. There were no statistically significant differences under dorsal and volar bending. In this model of distal radial fractures, there was a difference regarding the stiffness and the placement of screws in the distal rows of a volar fixed-angle plate. Inserting screws in all available holes in the distal fragment offered the highest stability. Using only the proximal row with 3 screws created an unstable situation. Based on these findings, we recommend placing at least 4 screws in the distal fragment and assigning at least 2 screws to the distal row of the multidirectional screw-holes. Copyright 2010 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  20. Trochanteric Fixation With a Third-Generation Cable-Plate System: An Independent Experience.

    PubMed

    Stewart, Andrew D; Abdelbary, Hesham; Beaulé, Paul E

    2017-09-01

    Greater trochanteric fracture/nonunion can be a devastating complication with significant functional impact after total hip arthroplasty, and their fixation remains a challenge because of the significant forces being transmitted as well as the poor bone quality often associated with these fractures. The objective of this study is to investigate the rates of reoperation and trochanteric nonunion using a third-generation cable-plate system at one center. Thirty-five patients, mean age 72.9 years (range 46-98 years) with 24 women and 11 men, underwent fixation of their fractured greater trochanter using a third-generation cable-plate system. The indications were: periprosthetic fracture (n = 17), complex primary arthroplasty (n = 5), and complex revision arthroplasty (n = 13). Primary outcomes included rates of reoperation and radiographic union. At a mean follow-up of 2.5 years, trochanteric union rate was 62.9% with nonunion rate of 31.4%, and fibrous union in 5.7%. In regard to quality of initial apposition, only 40% achieved a perfect bone on bone reduction. Ten patients (28.6%) had evidence of wire breakage. Five patients (14.3%) required reoperation and removal of the internal fixation because of lateral hip pain. Fixation of the trochanteric fractures remains a challenge with a relatively high reoperation rate. Poor bone quality and capacity to maintain a stable reduction continue to make this complication after total hip arthroplasty a difficult problem to solve. Copyright © 2017. Published by Elsevier Inc.

  1. Biomechanical evaluation of suture-augmented locking plate fixation for proximal third fractures of the olecranon.

    PubMed

    Wild, Jason R; Askam, Brad M; Margolis, David S; Geffre, Christopher P; Krupinski, Elizabeth A; Truchan, Lisa M

    2012-09-01

    To describe a method of suture augmentation of locking plate fixation (PF) of proximal olecranon fractures and to evaluate the biomechanical effectiveness of the suture augmentation using a human cadaveric model. Six matched pairs of cadaveric elbows were used. Proximal one-third fractures of the olecranon were simulated via a transverse osteotomy. Identical locking PF was performed on each elbow using olecranon locking plates. One elbow of each pair was assigned to suture augmentation of the construct. The choice of left/right specimen for augmentation was performed in an alternating fashion. Augmentation was performed using a no. 2 ultra-high-molecular weight polyethylene-braided suture attaching the triceps to the plate via a modified Krackow stitch. The elbows were mounted into a custom jig and linearly loaded to failure using a hydraulic testing machine. Load to and modes of failure were recorded for each sample. The data were analyzed using the Wilcoxon signed-rank test for nonparametric distributions. Suture augmentation improved the single load-to-failure strength in all pairs. One pair was excluded due to failure of the triceps attachment to the test machine. A median 398 N (P = 0.04 range, 197-633 N) or a median 48% (range, 30%-130%) improvement in strength was seen. The most common mode of failure was loss of fixation of the proximal olecranon fragment. Suture augmentation can significantly increase the single load-to-failure strength of locking PF for proximal olecranon fractures.

  2. Patient-tailored plate for bone fixation and accurate 3D positioning in corrective osteotomy.

    PubMed

    Dobbe, J G G; Vroemen, J C; Strackee, S D; Streekstra, G J

    2013-02-01

    A bone fracture may lead to malunion of bone segments, which gives discomfort to the patient and may lead to chronic pain, reduced function and finally to early osteoarthritis. Corrective osteotomy is a treatment option to realign the bone segments. In this procedure, the surgeon tries to improve alignment by cutting the bone at, or near, the fracture location and fixates the bone segments in an improved position, using a plate and screws. Three-dimensional positioning is very complex and difficult to plan, perform and evaluate using standard 2D fluoroscopy imaging. This study introduces a new technique that uses preoperative 3D imaging to plan positioning and design a patient-tailored fixation plate that only fits in one way and realigns the bone segments as planned. The method is evaluated using artificial bones and renders realignment highly accurate and very reproducible (d(err) < 1.2 ± 0.8 mm and φ(err) < 1.8° ± 2.1°). Application of a patient-tailored plate is expected to be of great value for future corrective osteotomy surgeries.

  3. PERPENDICULAR DOUBLE-PLATE FIXATION WITH LOCKING SYSTEM FOR ACROMION PEDICLE FRACTURE

    PubMed Central

    Zhu, Junkun; Pan, Zhijun; Zheng, Rongzong; Lan, Shuhua

    2016-01-01

    Objective : To describe the surgical technique and preliminary clinical outcomes in a series of open reduction internal fixation of basal acromion process fractures applying a double-plating technique. Methods : Nine consecutive patients, mean age 33.4 years old (range, 23-61 years old) with unilateral acromion fracture (Type 3 AO/OTA) with more than 1cm displacement who underwent fixation utilizing a locked double-plating technique, were evaluated on average at 7.8 months (range, 3-15 months) for outcomes related to pain, shoulder function, and surgical complications. Results : Eight patients recovered with complete radiographic union and favorable shoulder function. One case failed to be fully evaluated for more than 3 months follow-up. The overall scores of Constant, Shoulder Pain and Disability Index (SPADI) and DASH for the eight patients reviewed were 91.9± 6.31, 3.11± 3.79 and 5.2± 6.35, respectively. No post-operative infection or surgical hardware irritation was identified at final follow-up of these eight patients. Conclusion : While more evidence is needed to justify its advantages over traditional implants, perpendicular double-plate with a locking system may be indicated for acromion pedicle fracture treatment, since it performed well for fracture healing and joint function rehabilitation. Level of Evidence IV, Therapeutic Study. PMID:26981047

  4. Analysis of a Lane-plate internal fixation device after 64 years in vivo.

    PubMed

    McAuley, J P; Gow, K V; Covert, A; McDermott, A G; Yabsley, R H

    1987-11-01

    A patient presented for an above-knee amputation 64 years after successful internal fixation of a femoral fracture with a Lane plate. Chemical analyses of the plate and corrosion products were done using atomic absorption spectrophotometry, x-ray energy spectroscopy and x-ray diffraction. Mechanical properties of the fixation devices were measured using Rockwell-type instruments and metallographic analyses were also performed. In addition, pathologic and radiologic investigations of the underlying bone were carried out. Results disclosed that extensive corrosion had weakened the plate by 50%. The metallosis of the surrounding soft tissues and abnormal morphologic features of underlying bone were analysed. No appreciable cellular inflammatory or dysplastic reaction of adjacent tissues was identified. The underlying bone showed a persistent lack of mature compact bone and no evidence of remodelling. The products of corrosion were mainly ferrous carbonate and some ferrous chloride. The mechanism of the corrosion was the formation of a galvanic cell between the iron carbide and surrounding iron, with dissolution of the iron and formation of the corrosion products.

  5. Early breakage of a titanium volar locking plate for fixation of a distal radius fracture: case report.

    PubMed

    Yukata, Kiminori; Doi, Kazuteru; Hattori, Yasunori; Sakamoto, Soutetsu

    2009-01-01

    This report presents a case demonstrating the early breakage of a titanium volar locking plate implanted for internal fixation of a dorsally displaced distal radius fracture in which the dorsal cortex was severely comminuted. Careful selection of the proper plate and appropriate surgical technique and postoperative management are necessary to avoid this complication.

  6. Internal plate fixation versus plaster in displaced complete articular distal radius fractures, a randomised controlled trial.

    PubMed

    Mulders, Marjolein A M; Walenkamp, Monique M J; Goslings, J Carel; Schep, Niels W L

    2016-02-09

    Of all distal radius fractures, 25 % are complete articular fractures (AO/OTA type C fractures). Two thirds of those fractures are displaced and require reduction. According to several International Guidelines, adequately reduced intra-articular distal radius fractures are best treated non-operatively with plaster immobilisation, while surgical fixation is suggested only when the articular step exceeds 2 mm after reduction. However, these recommendations are based on studies that did not differentiate between intra- and extra-articular distal radius fractures. Thus, no clear consensus about the best treatment for patients with displaced intra-articular distal radius fractures can be reached. Despite the lack of evidence, an increase in internal fixation of intra-articular distal radius fractures has been observed over the last decade. The aim of this study is to determine the difference in functional outcome following open reduction and plate fixation compared with non-operative treatment with closed reduction and plaster immobilisation in patients with a displaced intra articular distal radius fracture. This multicentre randomised controlled trial will randomise between open reduction and internal plate fixation (intervention group) and closed reduction and plaster immobilisation (control group). All consecutive adult patients from 18 to 65 years with a displaced intra-articular distal radius fracture (AO/OTA type C), which has been adequately reduced at the Emergency Department according to the Dutch National Guidelines, are eligible for inclusion in this study. The primary outcome is function and pain of the wrist assessed with the Patient-Rated Wrist Evaluation score (PRWE). Secondary outcomes are the Disability of the Arm, Shoulder and Hand score (DASH), pain, quality of life (SF-36), range of motion, grip strength, radiological parameters, complications, crossovers and cost-effectiveness of both treatments. A total of 90 patients will be included in this

  7. Managing Vancouver B1 fractures by cerclage system compared to locking plate fixation - a biomechanical study.

    PubMed

    Gordon, Katharina; Winkler, Martin; Hofstädter, Thomas; Dorn, Ulrich; Augat, Peter

    2016-06-01

    With increasing life expectancy and number of total hip arthroplasties (THA), the need for revision surgery is increasing too. The aim of this study was to evaluate the optimal fracture treatment for a clinically characteristic Vancouver B1 fracture. We hypothesized that locking plate fixation has biomechanical advantages over fixation with a simple cerclage system. Additionally, we hypothesized that removal of the primary short stem and revision with a long stem would show biomechanical benefit. The biomechanical testing was performed with a static and a dynamic loading protocol on twenty 4th Generation sawbones. These were divided into four different groups (n = 5 each). In group 1, the primary uncemented short stem remained and the fracture was stabilized with a locking plate. In group 2, the primary stem remained and the fracture was stabilized with a cerclage stabilization system containing two stabilizers and four cerclages. In group 3, the primary stem was replaced by an uncemented long revision stem and the fracture was fixed with a locking plate. In group 4, the short stem was replaced by a long revision stem and the fracture was fixed with the cerclage system. Static testing revealed that the revision of the short stem with the long stem caused a 2-fold (p < 0.001, ANOVA) increase of axial stiffness. In dynamic testing, the number of cycles to failure was 4 times (p < 0.001, ANOVA) higher with the long revision stem. Compared to locked plating cerclage wiring demonstrated a 26% more cycles to failure (p = 0.031, ANOVA). The load to failure was 91% larger (p < 0.001, ANOVA) with the long revision stem and 11% smaller with locked plating (p < 0.001, ANOVA). In conclusion, the present biomechanical study indicates that periprosthetic Vancouver B1 fractures can be sufficiently fixed by simple cerclage systems. Revision with a long replacement stem provides a superior mechanical stability regardless of type of osteosynthesis fixation and is therefore a viable

  8. [Biphasic ceramic wedge and plate fixation with locked adjustable screws for open wedge tibial osteotomy].

    PubMed

    Lavallé, F; Pascal-Mousselard, H; Rouvillain, J L; Ribeyre, D; Delattre, O; Catonné, Y

    2004-10-01

    The aim of this radiological study was to evaluate the use of a biphasic ceramic wedge combined with plate fixation with locked adjustable screws for open wedge tibial osteotomy. Twenty-six consecutive patients (27 knees) underwent surgery between December 1999 and March 2002 to establish a normal lower-limb axis. The series included 6 women and 20 men, mean age 50 years (16 right knees and 11 left knees). Partial weight-bearing with crutches was allowed on day 1. A standard radiological assessment was performed on day 1, 90, and 360 (plain AP and lateral stance films of the knee). A pangonogram was performed before surgery and at day 360. Presence of a lateral metaphyseal space, development of peripheral cortical bridges, and osteointegration of the bone substitute-bone interface were evaluated used to assess bone healing. The medial tibial angle between the line tangent to the tibial plateau and the anatomic axis of the tibia (beta) was evaluated to assess preservation of postoperative correction. The HKA angle was determined. Three patients were lost to follow-up and 23 patients (24 knees) were retained for analysis. At last follow-up, presence of peripheral cortical bridges and complete filling of the lateral metaphyseal space demonstrated bone healing in all patients. Good quality osteointegration was achieved since 21 knees did not present an interface between the bone substitute and native bone (homogeneous transition zone). The beta angle was unchanged for 23 knees. A normal axis was observed in patients (16 knees) postoperatively. Use of a biphasic ceramic wedge in combination with plate fixation with locked adjustable screws is a reliable option for open wedge tibial osteotomy. The bone substitute fills the gap well. Tolerance and integration are optimal. Bone healing is achieved. Plate fixation with protected weight bearing appears to be a solid assembly, maintaining these corrections.

  9. Open Reduction and Internal Fixation of Displaced Calcaneum, Intra-Articular Fractures by Locking Calcaneal Plate

    PubMed Central

    Santosha; Singh, Arambam Mahendra; Waikhom, Sanjib; Pakhrin, Vishal; Mukherjee, Sagnik; Debbarma, Rajkumar; Prashant, Prabhu Shrinivas

    2016-01-01

    Introduction Calcaneal fractures constitute the most common fractures in hindfoot. Lots of controversies exist in the management of calcaneal fractures but now-a-days, it is preferable to perform open reduction and internal fixation and early mobilizatation. Aim To evaluate the functional outcome after open reduction and internal fixation of displaced intra-articular fractures of the calcaneum by locking calcaneal plate. Materials and Methods The study was conducted in the Department of Orthopaedic Surgery from September 2013 to April 2016. Thirty intra-articular fractures of the calcaneum were treated by locking calcaneal plate. Patients were followed up for a period of 24 months. Bohler’s angle was measured in preoperative, immediate Post-operative period and after 2 years, follow-up was compared. Results were evaluated according to American Orthopaedic Foot and Ankle Society (AOFAS) Score. Results After 24 months of follow-up, all 24 patients were available for evaluation. Radiological union was achieved in a mean time of 12.5 weeks. Mean duration of hospital stay was 21 days. Bohler’s angle was significantly higher after 2 years of follow-up when compared with preoperative x-ray. According to the AOFAS, Ankle–Hind foot Scale outcome score results were excellent in 43.3% of the patients, good in 33.3%, fair in 10%, and poor in 13.3% of patients. The mean AOFAS score was 79.9 (Range 49-96). Conclusion Open reduction and internal fixation of intra-articular fractures of the calcaneum with locking calcaneal plate gives good results. Maintenance of calcaneal height and Bohler’s angle helps to decrease the incidence of subtalar arthritis. PMID:28208957

  10. 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.

  11. Buckling behavior of long symmetrically laminated plates subjected to compression, shear, and inplane bending loads

    NASA Technical Reports Server (NTRS)

    Nemeth, Michael P.

    1992-01-01

    A parametric study of the buckling behavior of infinitely long symmetrically laminated anisotropic plates subjected to combined loadings are presented. The loading conditions considered are pure inplane bending, transverse tension and compression, and shear. Results obtained using a special purpose analysis are presented for clamped and simply supported plates. An important finding of the study is that the effects of anisotropy are much more pronounced in shear-loaded plates than in axial compression-loaded plates and plates loaded by pure inplane bending.

  12. Comparison of results between hook plate fixation and ligament reconstruction for acute unstable acromioclavicular joint dislocation.

    PubMed

    Yoon, Jong Pil; Lee, Byoung-Joo; Nam, Sang Jin; Chung, Seok Won; Jeong, Won-Ju; Min, Woo-Kie; Oh, Joo Han

    2015-03-01

    In the present study, we aimed to compare clinical and radiographic outcomes between hook plate fixation and coracoclavicular (CC) ligament reconstruction for the treatment of acute unstable acromioclavicular (AC) joint dislocation. Forty-two patients who underwent surgery for an unstable acute dislocation of the AC joint were included. We divided them into two groups according to the treatment modality: internal fixation with a hook plate (group I, 24 cases) or CC ligament reconstruction (group II, 18 cases). We evaluated the clinical outcomes using a visual analog scale (VAS) for pain and Constant-Murley score, and assessed the radiographic outcomes based on the reduction and loss of CC distance on preoperative, postoperative, and final follow-up plain radiographs. The mean VAS scores at the final follow-up were 1.6 ± 1.5 and 1.3 ± 1.3 in groups I and II, respectively, which were not significantly different. The mean Constant-Murley scores were 90.2 ± 9.9 and 89.2 ± 3.5 in groups I and II, respectively, which were also not significantly different. The AC joints were well reduced in both groups, whereas CC distance improved from a mean of 215.7% ± 50.9% preoperatively to 106.1% ± 10.2% at the final follow-up in group I, and from 239.9% ± 59.2% preoperatively to 133.6% ± 36.7% at the final follow-up in group II. The improvement in group I was significantly superior to that in group II (p < 0.001). Furthermore, subluxation was not observed in any case in group I, but was noted in six cases (33%) in group II. Erosions of the acromion undersurface were observed in 9 cases in group I. In cases of acute unstable AC joint dislocation, hook plate fixation and CC ligament reconstruction yield comparable satisfactory clinical outcomes. However, radiographic outcomes based on the maintenance of reduction indicate that hook plate fixation is a better treatment option.

  13. A new volar plate DiPhos-RM for fixation of distal radius fracture: preliminary report.

    PubMed

    Tarallo, Luigi; Mugnai, Raffaele; Adani, Roberto; Catani, Fabio

    2013-03-01

    We analyzed the efficiency of a new plate DiPhos-RM in CFR-PEEK [carbon-fiber-reinforced poly (etheretherketone)] for the volar fixation of distal radius fractures. The new plate's composition has the advantage of x-ray absolute transparency, therefore allowing to monitor the healing of the fracture. The desired combination of high strength and low rigidity is obtained through the use of the polymer composites CFR-PEEK. In this preliminary study (from March 2012 to June 2012), 10 cases of intra-articular distal radius fractures were treated with DiPhos-RM produced by Lima Corporate (Italy). The fractures were classified according to the AO classification, 4 fractures were type C1, 3 type C2, and 3 were A2. A preoperative computed tomography scan was carried out in all patients. One patient also underwent a postoperative computed tomography scan. Grip strength, range of motion, and DASH score were evaluated at follow-up. There were no cases of hardware failure. Specifically, no loss of position or alignment of fixed-angle locking screws or breakage of the plate were observed. Radiographic union was present at an average of 6 weeks (range, 5 to 8 wk). The overall preliminary experience with this new plate is favorable. The new plate is easy to apply and provides the surgeon dual options of fixed-angle or variable-angle screws. It was rigid enough to maintain the reduction also in AO type C articular fractures.

  14. Radiological Outcomes of Distal Radius Fractures Managed with 2.7mm Volar Locking Plate Fixation-A Retrospective Analysis

    PubMed Central

    Kotian, Prem; Mudiganty, Srikanth; Annappa, Rajendra

    2017-01-01

    Introduction Distal radius fractures accounts for around 15% of all fractures diagnosed and treated in the emergency rooms. These fractures usually result secondary to high velocity injury such as a motor vehicle accident or fall on an out stretched hand. In the elderly, it is a common fragility fracture. Volar Locking Compression Plates (LCP) is effective devices for fixation of the distal radius fractures. There is a lacuna with regard to literature on the 2.7 mm volar LCP and the current study retrospectively assesses the postoperative radiological outcomes. Aim To measure the radiological outcomes in patients with displaced distal radius fractures managed with 2.7 mm volar LCP fixation using Sarmiento’s Modification of Lindstorm Criteria. Materials and Methods A retrospective study was conducted in the Department of Orthopaedic Surgery at Kasturba Medical College Allied Hospitals, Mangalore from May 2014 to July 2016. All displaced distal radius fractures of skeletally mature patients who underwent volar locking plate fixation between May 2014 to July 2016 and follow up with X-rays at six weeks and three months were included as part of the study. The study comprised of 20 patients and fractures were classified using the AO and Melone’s classification systems. The radiological outcome was scored based on Sarmiento’s Modification of Lindstorm Criteria. Results Post operative check X-rays were analysed at immediate post operative, six weeks and three months. The mean immediate post operative radial shortening, decrease in radial deviation and loss of palmar tilt were 4.08±2.23, 5.91±4.01and 4.11±3.29 respectively. The corresponding values at last follow up were 4.71±2.31, 7.9±5.13 and 4.91±3.32 respectively. No statistically significant difference (p=0.930;874;716) in radial shortening, decrease in palmar angulation and loss of radial deviation was seen till the final follow up. Sarmiento’s Modification of Lindstorm Criteria showed a good

  15. Stainless steel versus titanium volar multi-axial locking plates for fixation of distal radius fractures: a randomised clinical trial.

    PubMed

    Couzens, Gregory B; Peters, Susan E; Cutbush, Kenneth; Hope, Benjamin; Taylor, Fraser; James, Christopher D; Rankin, Carly R; Ross, Mark

    2014-03-11

    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. 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

  16. Mechanical effects of high density polyethylene dynamic compression plate hole inserts on bone-plate constructs.

    PubMed

    Sullivan, E K; Nunamaker, D M; Richardson, D W

    2005-01-01

    This study was conducted in order to investigate the mechanical effects of high density polyethylene screw hole inserts in 4.5 mm Dynamic Compression Plate (DCP)--synthetic bone constructs. A mid-shaft 'osteotomy' was created in synthetic bone cylinders. The bisecting 'osteotomy' was reduced using six-hole broad DCPs and 4.5 mm cortical bone screws. The screws adjacent to the 'osteotomy' were placed using a load-guide. The remaining screws were placed in neutral position. High density polyethylene DCP screw hole inserts were incorporated with each screw in neutral position, in the experimental group. The bone plate constructs were tested in four point cyclical bending with the plates loaded at 2,000 Newtons, for a total of 6,000 cycles. Osteotomy gap was measured at 3,000 and 6,000 cycles. Screw head deflection adjacent to the osteotomy was measured. Kruskal-Wallis non-parametric testing was used for statistical comparisons. There was significantly less gapping at the osteotomy site in the treatment group after 3,000 cycles (0.49 +/- 0.18 mm [control] vs. 0.06 +/- 0.14 mm [treated], P=0.02) and 6,000 cycles (0.6 +/- 0.18 mm [control] vs. 0.1 +/- 0.22 mm [treated], P=0.02). The screws adjacent to the gap were significantly more deformed in the control group than those in the treated constructs (3.63 +/- 1.81 [control] vs. 1.06 +/- 1.55 [treated], P=0.0002). The polyethylene inserts improved the interface between bone plate and screw head, resulting in decreased relative movement of the implant and bone. The polyethylene inserts also resulted in less bending of the loaded screws.

  17. Locking compression plates for pancarpal arthrodesis in a Thoroughbred filly.

    PubMed

    Carpenter, Ryan S; Goodrich, Laurie R; Baxter, Gary M; Joyce, Jolynn; Wallis, Tyson W

    2008-08-01

    To report treatment of a comminuted ulnar carpal (UC) bone fracture associated with carpal instability by pancarpal arthrodesis using 2 locking compression plates (LCP). Case report. A 2-year-old Thoroughbred filly. An UC fracture and luxation of the proximal row of carpal bones was diagnosed radiographically. Pancarpal arthrodesis was performed with 2 LCP positioned dorsolaterally and dorsomedially and centered over the carpus through a single skin incision. The filly was maintained in a full limb cast for 15 days, followed by a tube cast for 14 days, and subsequently a full limb bandage with caudal splint for 21 days. Two LCP provided appropriate carpal stability resulting in a pasture sound horse 6 months after surgery. The filly was discharged from the hospital 63 days after surgery, walking well with only a slight mechanical lameness. Use of 2 LCP applied on the dorsomedial and dorsolateral aspect of the carpus can provide carpal stability for pancarpal arthrodesis. Excellent stability of the carpal joints can be achieved with 2 LCP.

  18. Does a minimal invasive approach reduce anterior chest wall numbness and postoperative pain in plate fixation of clavicle fractures?

    PubMed

    Beirer, Marc; Postl, Lukas; Crönlein, Moritz; Siebenlist, Sebastian; Huber-Wagner, Stefan; Braun, Karl F; Biberthaler, Peter; Kirchhoff, Chlodwig

    2015-05-28

    Fractures of the clavicle present very common injuries with a peak of incidence in young active patients. Recently published randomized clinical trials demonstrated an improved functional outcome and a lower rate of nonunions in comparison to non-operative treatment. Anterior chest wall numbness due to injury of the supraclavicular nerve and postoperative pain constitute common surgery related complications in plate fixation of displaced clavicle fractures. We recently developed a technique for mini open plating (MOP) of the clavicle to reduce postoperative numbness and pain. The purpose of this study was to analyze the size of anterior chest wall numbness and the intensity of postoperative pain in MOP in comparison to conventional open plating (COP) of clavicle fractures. 24 patients (mean age 38.2 ± 14.2 yrs.) with a displaced fracture of the clavicle (Orthopaedic Trauma Association B1.2-C1.2) surgically treated using a locking compression plate (LCP) were enrolled. 12 patients underwent MOP and another 12 patients COP. Anterior chest wall numbness was measured with a transparency grid on the second postoperative day and at the six months follow-up. Postoperative pain was evaluated using the Visual Analog Scale (VAS). Mean ratio of skin incision length to plate length was 0.61 ± 0.04 in the MOP group and 0.85 ± 0.06 in the COP group (p < 0.05). Mean ratio of the area of anterior chest wall numbness to plate length was postoperative 7.6 ± 5.9 (six months follow-up 4.7 ± 3.9) in the MOP group and 22.1 ± 19.1 (16.9 ± 14.1) in the COP group (p < 0.05). Mean VAS was 2.6 ± 1.4 points in the MOP group and 3.4 ± 1.6 points in the COP group (p = 0.20). In our study, MOP significantly reduced anterior chest wall numbness in comparison to a conventional open approach postoperative as well as at the six months follow-up. Postoperative pain tended to be lower in the MOP group, however this difference was not statistically significant. ClinicalTrials.gov NCT02247778

  19. A biomechanical comparison of multidirectional nail and locking plate fixation in unstable olecranon fractures.

    PubMed

    Argintar, Evan; Martin, Benjamin D; Singer, Andrea; Hsieh, Adam H; Edwards, Scott

    2012-10-01

    The main theoretic advantage of proximal olecranon fracture intramedullary fixation is decreased soft-tissue irritation and, potentially, less subsequent hardware removal. Despite this possible benefit, questions remain as to whether intramedullary devices are capable of controlling olecranon fractures to the same extent as locking plates. This study evaluates the ability of a novel multidirectional locking nail to stabilize comminuted fractures and directly compares its biomechanical performance with that of locking olecranon plates. We implanted 8 stainless steel locking plates and stainless steel intramedullary nails to stabilize a simulated comminuted fracture in 16 fresh-frozen cadaveric elbows. Flexion-extension, varus-valgus, gap distance, and rotational 3-dimensional angular displacement analysis was conducted over a 60° motion arc (30° to 90°) to assess fragment motion through physiologic cyclic arcs of motion and failure loading. Displacements in all planes were compared. Both implants showed less than 1° of motion in all measured planes and allowed less than 1 mm of gapping through all loads tested until ultimate failure. All failures occurred by sudden, catastrophic means. The mean failure weight for the nail was 14.4 kg compared with 8.7 kg for the plate (P = .02). The nail survived 1102 cycles, whereas the plate survived 831 cycles (P = .06). In simulated comminuted olecranon fractures, the multidirectional locking intramedullary nails sustained significantly higher maximum loads than the locking plates. The two implants showed no significant differences in fragment control or number of cycles survived. Surgeons can expect the multidirectional locking nails to stabilize comminuted fractures at least as well as locking plates. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  20. Scaphoid Plate Fixation and Volar Carpal Artery Vascularized Bone Graft for Recalcitrant Scaphoid Nonunions.

    PubMed

    Dodds, Seth D; Halim, Andrea

    2016-07-01

    We sought to evaluate the clinical and radiographic outcomes after treatment of symptomatic, recalcitrant scaphoid nonunions using a novel combination of volar scaphoid buttress plating with a pedicled vascularized bone graft. We retrospectively followed 9 patients with recalcitrant scaphoid waist nonunions, characterized by failed prior surgery, long duration of nonunion, avascular necrosis of the proximal pole, or considerable bone loss at the nonunion site. We treated these persistent nonunions through a single volar incision with a pedicled vascularized bone graft, based on the volar carpal artery, and a 1.5-mm precontoured, scaphoid-specific, volar buttress plate. Postoperatively, we assessed objective and subjective outcomes as well as radiographs and computed tomography scans. The median duration of nonunion was 15 months, ranging from 6 to 96 months. Postoperative follow-up ranged from 11 to 19 months. Computed tomography scans demonstrated union in 8 of 9 cases. Complications included 1 minor hematoma that spontaneously resolved. One scaphoid failed to unite, requiring revision surgery. Three patients experienced problems with the plate. One plate was removed from a patient who noted persistent clicking, and 2 plates have caused symptomatic clicking, likely requiring future removal. Eight of nine patients reported satisfaction with the procedure, with QuickDash scores averaging 8.2. We present a series of recalcitrant scaphoid nonunions treated with a novel technique of volar buttress plating and vascularized bone graft. In this series, we found a high rate of union, with consistent radiographic improvement and symptomatic relief. This procedure can be performed using a single incision and with minimal donor site morbidity. Volar plating of a scaphoid nonunion comes with the risk of articular prominence, but offers a new alternative to headless screw fixation. Our early results from this series are promising and support this protocol as a viable

  1. Sternal closure by rigid plate fixation in off-pump coronary artery bypass grafting: a comparative study.

    PubMed

    Matsuyama, Katsuhiko; Kuinose, Masahiko; Koizumi, Nobusato; Iwasaki, Tomoaki; Toguchi, Kayo; Ogino, Hitoshi

    2016-06-01

    Sternal instability or dehiscence results in serious sternal wound infection. We sought to assess the early outcomes with such a plating system for sternal closure in comparison to the conventional wiring technique in off-pump coronary artery bypass grafting (CABG). Patients who underwent off-pump CABG were enrolled. Thirty-one patients received plate sternal fixation. A total of 64 patients who underwent off-pump CABG by a single surgeon at our hospital from July 2013 to December 2014 were enrolled. Thirty-one patients received plate sternal fixation (Plate group), while 33 received conventional wire closure (Wire group). The early outcomes, including the pain score and analgesic usage count were compared. Dietary intake was also recorded to assess the duration of appetite loss. At discharge, the largest sternal displacement was measured on computed tomography. In the Plate group, the pain scores were significantly lower on post-operative day 5-8 and POD 9-12 from those in the Wire group. The analgesic usage count on POD 9-12 was significantly lower in the Plate group. The duration of appetite loss and hospital stay was significantly shorter in the Plate group. The displacement in both the anterior-posterior and lateral directions was significantly smaller in the Plate group. Sternal closure by rigid plate fixation contributes to a more rapid post-operative recovery through reduced pain.

  2. Comparisons of front plate, percutaneous sacroiliac screws, and sacroiliac anterior papilionaceous plate in fixation of unstable pelvic fractures.

    PubMed

    Gu, Ronghe; Huang, Weiguo; Yang, Lijing; Liu, Huijiang; Xie, Kegong; Huang, Zonggui

    2017-09-01

    This observational study was aimed at comparing the clinical efficacy of sacroiliac anterior plate fixation (SAPF), sacroiliac anterior papilionaceous plate (SAPP), and percutaneous sacroiliac screw internal fixation (PSCIF) introduced for patients with unstable pelvic fracture. Seventy-eight patients with unstable pelvic fracture (Tile type B or C) were recruited. Twenty-six patients underwent SAPF, 26 underwent SAPP, and 26 underwent PSCIF. Matta scores were calculated to evaluate the reduction of pelvic fractures, and Majeed scores were applied for the assessment of functional recoveries after surgery. Other perioperative clinical indicators were also recorded, including operation time, bleeding status, length of incision, ambulation time, fracture healing time, and incision infection. Total operation time of PSCIF was remarkably shorter than that of SAPF and SAPP (P < .05), and the bleeding volume of SAPF and SAPP group was almost 26∼29 times as high as that of PSCIF group (P < .05). Besides, SAPP resulted in significant blood loss compared with SAPF (P < .05), while SAPF resulted in significantly larger operative incision length than SAPP and PSCIF (P < .05). Moreover, patients' stay time was prolonged in both SAPF and SAPP groups than in the PSCIF group (P < .05). Patients who received PSCIF exhibited significantly higher Matta and Majeed scores than those who received SAPF (all P < .05). Finally, SAPP was associated with fewer complications than SAPF, and complications were barely observed in the PSCIF group. PSCIF may be more appropriate for patients with unstable pelvic fractures in comparison with SAPP and SAPF. Besides, SAPP is likely to be more efficacious than SAPF especially for Tile C patients.

  3. Percutaneous fixation with Kirschner wires versus volar locking plate fixation in adults with dorsally displaced fracture of distal radius: randomised controlled trial.

    PubMed

    Costa, Matthew L; Achten, Juul; Parsons, Nick R; Rangan, Amar; Griffin, Damian; Tubeuf, Sandy; Lamb, Sarah E

    2014-08-05

    To compare the clinical effectiveness of Kirschner wire fixation with locking plate fixation for patients with a dorsally displaced fracture of the distal radius. A multicentre two arm parallel group assessor blind randomised controlled trial with 1:1 treatment allocation. 18 trauma centres in the United Kingdom. 461 adults with a dorsally displaced fracture of the distal radius within 3 cm of the radiocarpal joint that required surgical fixation. Patients were excluded if the surgeon thought that the surface of the wrist joint was so badly displaced it required open reduction. Kirschner wire fixation: wires are passed through the skin over the dorsal aspect of the distal radius and into the bone to hold the fracture in the correct anatomical position. Locking plate fixation: a locking plate is applied through an incision over the volar (palm) aspect of the wrist and secured to the bone with fixed angle locking screws. validated patient rated wrist evaluation (PRWE). This rates wrist function in two (equally weighted) sections concerning the patient's experience of pain and disability to give a score out of 100. disabilities of arm, shoulder, and hand (DASH) score, the EuroQol (EQ-5D), and complications related to the surgery. The baseline characteristics of the two groups were well balanced, and over 90% of patients completed follow-up. The wrist function of both groups of patients improved by 12 months. There was no clinically relevant difference in the patient rated wrist score at three, six, or 12 months (difference in favour of the plate group was -1.3, 95% confidence interval -4.5 to 1.8; P=0.40). Nor was there a clinically relevant difference in health related quality of life or the number of complications in each group. Contrary to the existing literature, and against the rapidly increasing use of locking plate fixation, this trial found no difference in functional outcome in patients with dorsally displaced fractures of the distal radius treated with

  4. Percutaneous fixation with Kirschner wires versus volar locking plate fixation in adults with dorsally displaced fracture of distal radius: randomised controlled trial

    PubMed Central

    Achten, Juul; Parsons, Nick R; Rangan, Amar; Griffin, Damian; Tubeuf, Sandy; Lamb, Sarah E

    2014-01-01

    Objectives To compare the clinical effectiveness of Kirschner wire fixation with locking plate fixation for patients with a dorsally displaced fracture of the distal radius. Design A multicentre two arm parallel group assessor blind randomised controlled trial with 1:1 treatment allocation. Setting 18 trauma centres in the United Kingdom. Participants 461 adults with a dorsally displaced fracture of the distal radius within 3 cm of the radiocarpal joint that required surgical fixation. Patients were excluded if the surgeon thought that the surface of the wrist joint was so badly displaced it required open reduction. Interventions Kirschner wire fixation: wires are passed through the skin over the dorsal aspect of the distal radius and into the bone to hold the fracture in the correct anatomical position. Locking plate fixation: a locking plate is applied through an incision over the volar (palm) aspect of the wrist and secured to the bone with fixed angle locking screws. Main outcome measures Primary outcome measure: validated patient rated wrist evaluation (PRWE). This rates wrist function in two (equally weighted) sections concerning the patient’s experience of pain and disability to give a score out of 100. Secondary outcomes: disabilities of arm, shoulder, and hand (DASH) score, the EuroQol (EQ-5D), and complications related to the surgery. Results The baseline characteristics of the two groups were well balanced, and over 90% of patients completed follow-up. The wrist function of both groups of patients improved by 12 months. There was no clinically relevant difference in the patient rated wrist score at three, six, or 12 months (difference in favour of the plate group was −1.3, 95% confidence interval −4.5 to 1.8; P=0.40). Nor was there a clinically relevant difference in health related quality of life or the number of complications in each group. Conclusions Contrary to the existing literature, and against the rapidly increasing use of locking plate

  5. Biomechanical testing of distal femur osteotomy plate fixation techniques: the role of simulated physiological loading.

    PubMed

    Brinkman, Justus-Martijn; Hurschler, Christof; Agneskirchner, Jens; Lobenhoffer, Philip; Castelein, René M; van Heerwaarden, Ronald J

    2014-12-01

    Implants for fracture and/or osteotomy fixation are often tested according to basic mechanical test models such as open gap tests or 4-point-bending tests. These may be suitable to test and compare different implants for safety and clinical approval, but are not always representative of the post-operative situation, which is decisive when it comes to bone healing. In the current study the Knee Expert Group of the Association for the Study of Internal Fixation has compared the available open gap test results of the latest version of the TomoFix Medial Distal Femoral Plate and the antecedent plate design, with the test results of a more physiological and life-like test model. In the open gap test model the antecedent plate design was found to have superior stiffness and fatigue strength. In the current study simulated postoperative conditions for medial closing wedge supracondylar osteotomies were used. The constructs were subjected to cyclical axial and torsional loading and were subsequently tested to failure. The more life-like tests in this study showed that the latest version was either more or equally stable and stiff than the antecedent version of the plate, in all of the tests. It is argued that the difference in results between the two loading models is due to differences in test design. These test results stress the importance of not only using standard open gap and 4-point-bending tests, but also to use as life-like as possible test conditions for any form of biomechanical testing of new implants.

  6. Mini hook plate fixation for palmar fracture-dislocation of the proximal interphalangeal joint.

    PubMed

    Komura, Shingo; Yokoi, Tatsuo; Nonomura, Hidehiko

    2011-04-01

    Fracture-dislocations of the proximal interphalangeal joint are challenging to treat, since it is difficult to achieve both rigid fixation and early joint motion simultaneously. Palmar fracture-dislocations of the proximal interphalangeal joint are less frequent injuries and a small number of treatment methods have been reported. We describe here a patient with a chronic palmar fracture-dislocation of the proximal interphalangeal joint, who was treated with a new surgical technique. In the surgery, a mini hook plate that was made by adapting a 1.5 mm AO hand modular system straight plate was used. Despite the thinness of the fragment, rigid fixation was achieved, resulting in early active motion. At final follow up, the active ranges of motion were 0°-100° at the proximal and 0°-80° at the distal interphalangeal joint, and there were no complications. This technique may become a useful surgical method to treat palmar fracture-dislocations of the proximal interphalangeal joint.

  7. A comparison of reversed locking compression-distal femoral plates and blade plates in osteotomies for young adult hip pathology.

    PubMed

    MacLean, Simon B M; Evans, Scott; O'Hara, John N

    2013-01-01

    The aim of this study was to compare fixation of proximal femoral osteotomies using reverse contralateral LCP-Distal Femoral Plates (LCP-DF) with the more traditional blade plate technique. This was a retrospective review over six years of a single surgeon's practice within a tertiary orthopaedic unit. Patient demographics were collected, along with indication for surgery. Radiological outcomes, fixation failures and the need for revision surgery were recorded. Forty-six patients were identified; 23 patients in the LCP-DF plate group (7 females, 16 males. Mean age 18.3 years old) and 23 patients in the blade plate group (6 females, 17 males. Mean age 19.1 years old). The patients' presenting conditions were; 26 Perthes'; eight hip dysplasia; 11 slipped capital femoral epiphysis; one fibrous dysplasia. Osteotomy type included; 13 Double osteotomy, 11 Imhauser; 13 pure valgus; eight valgus + rotation; There was one revision for implant failure in the LCP-DF group. In the blade plate group, there were four implant failures--three requiring revision operations (p = 0.155). In the LCP-DF group the mean neck-shaft angle difference compared to the contralateral side (if normal) or 135 degrees (if abnormal) was 0.58°. In the condylar plate group the mean difference was 4.37°. The use of a contralateral LCP-DF plate in the reverse contralateral position to stabilise proximal femoral osteotomies in our cohort confers advantages over blade plate technology. We have found that the plate is stiffer, is easier to use and provides increased screw placement options over standard proximal femoral locking plates.

  8. Plate selection for fixation of extra-articular distal humerus fractures: a biomechanical comparison of three different implants.

    PubMed

    Scolaro, John A; Hsu, Jason E; Svach, David J; Mehta, Samir

    2014-12-01

    Operative fixation of extra-articular distal humerus using a single posterolateral column plate has been described but the biomechanical properties or limits of this technique is undefined. The purpose of this study was to evaluate the mechanical properties of distal humerus fracture fixation using three standard fixation constructs. Two equal groups were created from forty sawbones humeri. Osteotomies were created at 80mm or 50mm from the tip of the trochlea. In the proximal osteotomy group, sawbones were fixed with an 8-hole 3.5mm LCP or with a 6-hole posterolateral plate. In the distal group, sawbones were fixed with 9-hole medial and lateral 3.5mm distal humerus plates and ten sawbones were fixed with a 6-hole posterolateral plate. Biomechanical testing was performed using a servohydraulic testing machine. Testing in extension as well as internal and external rotation was performed. Destructive testing was also performed with failure being defined as hardware pullout, sawbone failure or cortical contact at the osteotomy. In the proximal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than with the 3.5mm LCP. In the distal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than the 3.5mm LCP. In extension testing, the yield strength was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. The yield strength of specimens in axial torsion was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. Limited biomechanical data to support the use of a pre-contoured posterolateral distal humerus LCP for fixation of extra-articular distal humerus exists. We have found that this implant provided significantly greater

  9. Use of locking compression plates in ulnar fractures of 18 horses.

    PubMed

    Jacobs, Carrie C; Levine, David G; Richardson, Dean W

    2017-02-01

    To describe the outcome, clinical findings, and complications associated with the use of the locking compression plate (LCP) for various types of ulnar fractures in horses. Retrospective case series. Client owned horses (n = 18). Medical records, radiographs, and follow-up for horses having an ulnar fracture repaired using at least 1 LCP were reviewed. Fifteen of 18 horses had fractures of the ulna only, and 3 horses had fractures of the ulna and proximal radius. All 18 horses were discharged from the hospital. Complications occurred in 5 horses; incisional infection (n = 4, 22%), implant-associated infection (n = 2, 11%), and colic (n = 1, 6%). Follow-up was available for all horses at a range of 13-120 months and 15 horses (83%) were sound for their intended purpose and 3 horses (17%) were euthanatized. One horse was euthanatized for complications associated with original injury and surgery. The LCP is a viable method of internal fixation for various types of ulnar fractures, with most horses in this series returning to soundness. © 2017 The American College of Veterinary Surgeons.

  10. Does plugging unused combination screw holes improve the fatigue life of fixation with locking plates in comminuted supracondylar fractures of the femur?

    PubMed

    Firoozabadi, R; McDonald, E; Nguyen, T-Q; Buckley, J M; Kandemir, U

    2012-02-01

    Filling the empty holes in peri-articular locking plates may improve the fatigue strength of the fixation. The purpose of this in vitro study was to investigate the effect of plugging the unused holes on the fatigue life of peri-articular distal femoral plates used to fix a comminuted supracondylar fracture model. A locking/compression plate was applied to 33 synthetic femurs and then a 6 cm metaphyseal defect was created (AO Type 33-A3). The specimens were then divided into three groups: unplugged, plugged with locking screw only and fully plugged holes. They were then tested using a stepwise or run-out fatigue protocol, each applying cyclic physiological multiaxial loads. All specimens in the stepwise group failed at the 770 N load level. The mean number of cycles to failure for the stepwise specimen was 25,500 cycles (SD 1500), 28,800 cycles (SD 6300), and 26,400 cycles (SD 2300) cycles for the unplugged, screw only and fully plugged configurations, respectively (p = 0.16). The mean number of cycles to failure for the run-out specimens was 42,800 cycles (SD 10,700), 36,000 cycles (SD 7200), and 36,600 cycles (SD 10,000) for the unplugged, screw only and fully plugged configurations, respectively (p = 0.50). There were also no differences in axial or torsional stiffness between the constructs. The failures were through the screw holes at the level of comminution. In conclusion, filling the empty combination locking/compression holes in peri-articular distal femur locking plates at the level of supracondylar comminution does not increase the fatigue life of the fixation in a comminuted supracondylar femoral fracture model (AO 33-A3) with a 6 cm gap.

  11. Buckling and postbuckling behavior of square compression-loaded graphite-epoxy plates with circular cutouts

    NASA Technical Reports Server (NTRS)

    Nemeth, Michael P.

    1989-01-01

    The postbuckling behavior of square compression-loaded graphite-epoxy plates and isotropic plates with a central circular cutout is studied. The results suggest that the change in the plate's axial stiffness is strongly dependent on cutout size and plate orthotropy. It is found that the cutout size and stacking sequence of a composite plate may be tailored to optimize postbuckling stiffness. Also, it is suggested that a cutout may influence model interaction in a plate. The effects of load-path eccentricity on buckling behavior are examined.

  12. [Management of Odontoid Fractures with Compression Screw and Anterior Transarticular Screw Fixation in Elderly Patients].

    PubMed

    Kočiš, J; Kelbl, M; Veselý, R; Kočiš, T

    2017-01-01

    PURPOSE OF THE STUDY In the management of dens axis fractures in patients older than 65 years of age the posterior approach is preferred due to osteoporosis and the risk of a failure of anterior osteosynthesis. The posterior approach, however, is associated with a higher incidence of complications. A combination of anterior transarticular fixation of C1/2 (ATS) with compression osteosynthesis of dens axis significantly increases the stability of osteosynthesis. MATERIAL AND METHODS In the period from 2009 to 2015 our hospital admitted 13 patients older than 65 years of age with a diagnosed type III dens axis fracture based on AO classification. 8 patients sustained a dens axis fracture combined with a stable atlas fracture. The cohort consisted of 13 women aged 67 to 90 years, with the mean age of 82.3 years. None of the female patients were affected neurologically. The dens axis fracture was treated by anterior approach. Once the screw was inserted in the dens axis, two more screws were added, the entrance points of those screws were medial and lateral to the odontoid screw and direction was divergently via C1/2 joints in order to reinforce stability. The patients were monitored at 6-week, 3-, 6- and 12-month follow-ups. Bone healing was confirmed by CT scan. RESULTS No complications were recorded during the surgery in any of the 13 patients. In one female patient the stabilization failed in the early postoperative period. A reoperation from anterior approach with the use of the same method was necessary. In eleven patients bone healing occurred after 6 to 12 months. In two patients pseudoarthrosis was formed with no clinical symptoms. No neurological deterioration or a patient s death was reported in the monitored period within 12 months after the treatment. DISCUSSION Where dens axis fractures in elderly patients are managed operatively, the posterior approach and transarticular fixation of C1/2 with sublaminar loop are preferred. This procedure is considered

  13. Effect of calcium phosphate bone cement augmentation on volar plate fixation of unstable distal radial fractures in the elderly.

    PubMed

    Kim, Jae Kwang; Koh, Young Do; Kook, Seung Hwan

    2011-04-06

    Calcium phosphate bone cement increases the stability of implant-bone constructs in patients with an osteoporotic fracture. The purpose of this randomized study was to determine whether augmentation of volar locking plate fixation with calcium phosphate bone cement has any benefit over volar locking plate fixation alone in patients older than sixty-five years of age who have an unstable distal radial fracture. Forty-eight patients (fifty unstable distal radial fractures) were recruited for this study. The mean patient age was seventy-three years. Surgical procedures were randomized between volar locking plate fixation alone (Group 1) and volar locking plate fixation with injection of calcium phosphate bone cement (Group 2). The patients were assessed clinically at three and twelve months postoperatively. Clinical assessments included determinations of grip strength, wrist motion, wrist pain, modified Mayo wrist scores, and Disabilities of the Arm, Shoulder and Hand (DASH) scores. Radiographic evaluations were performed immediately postoperatively and at one year following surgery. The adequacy of the reduction was assessed by measuring radial inclination, volar angulation, and ulnar variance. The two groups were comparable with regard to age, sex, fracture type, injury mechanism, and bone mineral density. No significant differences were observed between the groups with regard to the clinical outcomes at the three or twelve-month follow-up examination. No significant intergroup differences in radiographic outcomes were observed immediately after surgery or at the one-year follow-up visit. Furthermore, no complication-related differences were observed, and there were no nonunions. Augmentation of metaphyseal defects with calcium phosphate bone cement after volar locking plate fixation offered no benefit over volar locking plate fixation alone in elderly patients with an unstable distal radial fracture. © 2011 by the Journal of Bone and Joint Surgery, Incorporated

  14. Application of anterior debridement and reconstruction with anatomical screw-plate fixation for lumbosacral tuberculosis

    PubMed Central

    Wang, Wen-Jun; Chen, Wen-Kang; Yan, Yi-Guo; Yao, Nu-Zhao; Wang, Cheng

    2017-01-01

    Abstract This study aimed to determine the efficacy and safety of anterior debridement and reconstruction with anatomical screw-plate fixation in patients with lumbosacral junction tuberculosis (TB). A total of 48 patients (30 males and 18 females) diagnosed with lumbosacral junction TB were included in this study. All patients underwent surgery in our institution from January 2008 to July 2014, using anterior debridement and reconstruction with anatomical screw-plate. Outcome data were evaluated before and after surgery and included lumbosacral angle, Frankel classification, bone fusion, and visual analog scale (VAS) scores. All patients were then followed up for an average of 49.4 months (range, 24–96 months). The mean lumbosacral angle improved from 8.36° ± 5.92° pre-operation to 22.38° ± 4.52° post-operation and 21.13° ± 3.73° during the final follow-up (both P < .05). Solid vertebral fusion was achieved in all patients after 7.6 months on average (range, 6–12 months). No severe complications appeared during operation and post-operation. Neurological performance and VAS scores were significantly improved compared with pre-operation (P < .05). Following standard anti-TB chemotherapy, anterior debridement and reconstruction with anatomical screw-plate fixation may be a feasible and effective therapeutical option for lumbosacral junction TB. This procedure can result in satisfactory bone fusion and deformity correction, and effectively restore lumbosacral junction stability. PMID:28658103

  15. Comparison of olecranon plate fixation in osteoporotic bone: do current technologies and designs make a difference?

    PubMed

    Edwards, Scott G; Martin, Benjamin D; Fu, Rose H; Gill, Joseph M; Nezhad, Mani K; Orr, Jeffrey A; Ferrucci, Allen M; Love, James M; Booth, Richard; Singer, Andrea; Hsieh, Adam H

    2011-05-01

    The purpose of this study is to determine if recent innovations in olecranon plates have any advantages in stabilizing osteoporotic olecranon fractures. Five olecranon plates (Acumed, Synthes-SS, Synthes-Ti, US Implants/ITS, and Zimmer) were implanted to stabilize a simulated comminuted fracture pattern in 30 osteoporotic cadaveric elbows. Specimens were randomized by bone mineral density per dual-energy x-ray absorptiometry scan. Three-dimensional displacement analysis was conducted to assess fragment motion through physiological cyclic arcs of motion and failure loading, which was statistically compared using one-way analysis of variance and Tukey honestly significant difference post hoc comparisons with a critical significance level of α = 0.05. Bone mineral density ranged from 0.546 g/cm to 0.878 g/cm with an average of 0.666 g/cm. All implants limited displacement of the fragments to less than 3 mm until sudden, catastrophic failure as the bone of the proximal fragment pulled away from the implant. The maximum load sustained by all osteoporotic specimens ranged from 1.6 kg to 6.6 kg with an average of 4.4 kg. There was no statistical difference between the groups in terms of cycles survived and maximum loads sustained. Cyclic physiological loading of osteoporotic olecranon fracture fixation resulted in sudden, catastrophic failure of the bone-implant interface rather than in gradual implant loosening. Recent plate innovations such as locking plates and different screw designs and positions appear to offer no advantages in stabilizing osteoporotic olecranon fractures. Surgeons may be reassured that the current olecranon plates will probably adequately stabilize osteoporotic fractures for early motion in the early postoperative period, but not for heavy activities such as those that involve over 4 kg of resistance.

  16. Management of open fractures using a noncontact locking plate as an internal fixator.

    PubMed

    Yıldırım, Azad; Kapukaya, Ahmet; Mertsoy, Yılmaz; Yiğit, Şehmus; Çaçan, Mehmet Akif; Atiç, Ramazan

    2017-01-01

    The treatment of open fractures leads to major problems which may be due to various reasons. It mainly causes soft tissue problems due to the absorption of a large amount of energy by the soft tissues and bone tissues. Although some recent treatment protocols have eliminated many problems regarding delayed soft tissue closure, it still remains a big challange. This study uses a method called the internal fixator technique with noncontact locking plate (NC-LP) which involves the use of a combination of advantages of open and closed fixation techniques. 42 patients (32 men and 10 women) having a mean age of 34.11 years (range 17-56 years) with open fractures operated using internal fixator technique between 2007 and 2012 were included in this study. A retrospective chart review was conducted to record the following: age, gender, anatomic region of fractures, fracture etiology, classification of open fractures by Gustilo-Anderson and AO classification, surgeries, length of hospitalization, location and pattern of fracture, length of followup, and complications. The fractures were caused by traffic accidents, shotgun injuries, falls from heights, and industrial crush injuries. Based on the Gustilo-Anderson classification, 31 fractures were Type III and 11 were Type II, where 23 were localized in the tibia and 19 in the femur. Patients delay for a mean of 13.5 h (range 6-24 h) for operation and the mean followup interval was 27.8 months (range 16-44 months). The mean union time was 19.7 weeks (range 16-29 weeks). One patient had delayed union and implant failure, one patient had osteomyelitis, five suffered from surface skin necrosis, and one patient had an angulation of 17° in the sagittal plane, for which no additional intervention was performed. This case series demonstrates that an "internal fixator technique" is an acceptable alternative to the management of open fractures of the femur or tibia in adult patients. The NC-LP method provided opportunities to achieve

  17. Comminuted olecranon fracture fixation with pre-contoured plate: Comparison of composite and cadaver bones

    PubMed Central

    Hamilton Jr, David A; Reilly, Danielle; Wipf, Felix; Kamineni, Srinath

    2015-01-01

    AIM: To determine whether use of a precontoured olecranon plate provides adequate fixation to withstand supraphysiologic force in a comminuted olecranon fracture model. METHODS: Five samples of fourth generation composite bones and five samples of fresh frozen human cadaveric left ulnae were utilized for this study. The cadaveric specimens underwent dual-energy X-ray absorptiometry (DEXA) scanning to quantify the bone quality. The composite and cadaveric bones were prepared by creating a comminuted olecranon fracture and fixed with a pre-contoured olecranon plate with locking screws. Construct stiffness and failure load were measured by subjecting specimens to cantilever bending moments until failure. Fracture site motion was measured with differential variable resistance transducer spanning the fracture. Statistical analysis was performed with two-tailed Mann-Whitney-U test with Monte Carlo Exact test. RESULTS: There was a significant difference in fixation stiffness and strength between the composite bones and human cadaver bones. Failure modes differed in cadaveric and composite specimens. The load to failure for the composite bones (n = 5) and human cadaver bones (n = 5) specimens were 10.67 nm (range 9.40-11.91 nm) and 13.05 nm (range 12.59-15.38 nm) respectively. This difference was statistically significant (P ˂ 0.007, 97% power). Median stiffness for composite bones and human cadaver bones specimens were 5.69 nm/mm (range 4.69-6.80 nm/mm) and 7.55 nm/mm (range 6.31-7.72 nm/mm). There was a significant difference for stiffness (P ˂ 0.033, 79% power) between composite bones and cadaveric bones. No correlation was found between the DEXA results and stiffness. All cadaveric specimens withstood the physiologic load anticipated postoperatively. Catastrophic failure occurred in all composite specimens. All failures resulted from composite bone failure at the distal screw site and not hardware failure. There were no catastrophic fracture failures in the cadaveric

  18. Risk Factors for Deep Infection Following Plate Fixation of Proximal Tibial Fractures.

    PubMed

    Parkkinen, Markus; Madanat, Rami; Lindahl, Jan; Mäkinen, Tatu J

    2016-08-03

    The risk factors are unclear for deep surgical site infection after plate fixation of proximal tibial fractures. The objective of this study was to identify the patient and surgical procedure-related risk factors for infection using established criteria for deep surgical site infection. A total of 655 proximal tibial fractures were treated with open reduction and plate fixation at our center between 2004 and 2013. We identified 34 patients with deep surgical site infection. A control group of 136 patients was randomly selected from the non-infected cohort. Potential risk factors for deep surgical site infection were identified by reviewing surgical, medical, and radiographic records. Independent risk factors for infection were identified from multivariable logistic regression analysis using a stepwise procedure. The prevalence of deep surgical site infection was 5.2%, the mean age of affected patients was 55 years (range, 16 to 84 years), and 35% of patients were female. Twenty-eight of 34 deep infections were diagnosed within 2 months (acute onset), and only 6 infections were diagnosed >6 months after the index surgical procedure. Nine of the 28 acute-onset infections were treated with antibiotic therapy and debridement. Seventeen patients (50%) required muscle flap coverage, and 5 patients (15%) eventually required above-the-knee amputation. In the multivariable logistic regression analysis with odds ratios (ORs) and 95% confidence intervals (95% CIs), independent predictors of infection were patient age of ≥50 years (OR, 3.6 [95% CI, 1.3 to 10.1]); obesity, defined as a body mass index of ≥30 kg/m(2) (OR, 6.5 [95% CI, 2.2 to 18.9]); alcohol abuse (OR, 6.7 [95% CI, 2.4 to 19.2]); OTA/AO-type-C fracture (OR, 2.8 [95% CI, 1.1 to 7.5]); use of a temporary spanning external fixator (OR, 3.9 [95% CI, 1.4 to 11.1]); and a 4-compartment fasciotomy (OR, 4.5 [95% CI, 1.3 to 15.7]). There is high morbidity associated with deep surgical site infection in plated proximal

  19. Cage subsidence after anterior cervical discectomy and fusion using a cage alone or combined with anterior plate fixation.

    PubMed

    Pinder, E M; Sharp, D J

    2016-04-01

    To compare the extent of cage subsidence after anterior cervical discectomy and fusion (ACDF) using a cage alone or combined with anterior plate fixation, and to assess the effect of end plate removal on cage subsidence. Records of 23 men and 13 women aged 32 to 82 (mean, 54) years who underwent ACDF for 61 levels using the Solis cage alone (n=46) or combined with anterior plate fixation (n=15) were reviewed. The extent of cage subsidence was determined by comparing immediately postoperative (within one week) with final follow-up radiographs. Cage subsidence was defined as the sum subsidence of the superior and inferior part of the cage into the vertebral body. Mild and major cage subsidence was defined as ≤2 mm and >2 mm, respectively. Patients who underwent ACDF using a cage alone or combined with anterior plate fixation were comparable in terms of age, gender, follow-up duration, and number of levels decompressed. Cage subsidence occurred in 33 (54%) of the 61 levels decompressed. In the cage alone group, the extent of cage subsidence was greater (1.68 vs. 0.57 mm, p=0.039) and the rate of major cage subsidence was higher (28% vs. 7%, p=0.08). The inferior part of the cage was more vulnerable to subsidence compared with the superior part (median subsidence: 3.0 vs. 1.4 mm, p<0.0001). Cage subsidence occurred more often when the end plate was removed rather than preserved (58% vs. 18%, p<0.002). The extent of cage subsidence was greater after ACDF with cage alone. Cage subsidence occurred more often when the end plate was removed. Additional anterior plate fixation is recommended when the end plate is removed.

  20. Treatment of Humeral Shaft Fractures: Minimally Invasive Plate Osteosynthesis Versus Open Reduction and Internal Fixation

    PubMed Central

    Esmailiejah, Ali Akbar; Abbasian, Mohammad Reza; Safdari, Farshad; Ashoori, Keyqobad

    2015-01-01

    Background: The optimal technique for operative fixation of humeral shaft fractures remains controversial and warrants research. Objectives: The purpose of the current study was to compare the functional and clinical outcomes of conventional open reduction and internal fixation (ORIF) with minimally invasive plate osteosynthesis (MIPO) in patients with fractures in two-third distal humeral shaft. Patients and Methods: In the current prospective case-control study, 65 patients with humeral shaft fractures were treated using ORIF (33 patients) or MIPO (32 patients). Time of surgery, time of union, incidence of varus deformity and complications were compared between the two groups. Also, the university of California-Los Angeles (UCLA) shoulder rating scale and Mayo Elbow performance score (MEPS) were used to compare the functional outcomes between the two groups. Results: The median of union time was shorter in the MIPO group (4 months versus 5 months). The time of surgery and functional outcomes based on the UCLA and MEPS scores were the same. The incidence of varus deformity was more than 5° and was higher and the incidence of nonunion, infection and iatrogenic radial nerve injury were lower in the MIPO group; however, the differences were not significant. Conclusions: Due to the shorter union time, to some extent less complication rate and comparable functional and clinical results, the authors recommend to use the MIPO technique in treating the mid-distal humeral shaft fracture. PMID:26543844

  1. Postbuckling behavior of longitudinally compressed orthotropic plates with three-dimensional flexibility

    NASA Technical Reports Server (NTRS)

    Stein, M.; Bains, N. J. C.

    1986-01-01

    Postbuckling results for the average longitudinal compressive stress vs applied displacement are obtained for aluminum (isotropic), aluminum/epoxy (quasi-isotropic), and 45-deg graphite/epoxy (orthotropic) plates using classical (Kirchhoff) and conventional transverse shearing theories. An analysis of the results obtained shows that, in the postbuckling range, the classical theory cannot provide reasonably accurate results even for thin plates.

  2. Fixation of olecranon fractures and osteotomies using compression screws: a simple solution to a common problem. A study of cases.

    PubMed

    Haddad, Behrooz; Khan, Wasim; Zaghloul, Ahmed; Grimes, Lisa; Schenk, Willem

    2013-01-01

    Olecranon fractures are common skeletal injuries accounting for approximately 10% of upper extremity fractures in adults. Simple non-comminuted fractures are traditionally fixed using the tension band wiring technique. This technique, however, has several complications, most commonly prominence of the metalwork frequently requiring surgery for removal. We describe a retrospective review of a new method of fixation for these fractures using partially threaded screws in an attempt to avoid these complications. We used two 3.5 and/or 4 mm partially threaded screws to fix seven simple olecranon fractures and two olecranon osteotomies. Notes and clinic letters of all nine patients were reviewed for demographic data, operation details and complications. Radiographs were reviewed at final clinical follow-up. The Mayo Elbow Performance Score was completed during a telephone consultation. One patient injured her elbow postoperatively, which resulted in fragmentation of the proximal segment and loss of fixation. In one patient the tip of the screws broke after a fall but this did not result in loss of fixation. There were no problems with metalwork prominence or skin irritation in any of the patients. Two patients had low scores due to loss of fixation, and severely comminuted supracondylar fracture of the humerus. Six patients had good scores. We believe that use of AO compression screws is a valid method for the fixation of simple fractures of the olecranon. It is a safe technique and has several advantages over tension band fixation. There is minimal tissue dissection and operating time is decreased. There is minimal risk of metalwork prominence as screws obtain good purchase in the anterior cortex of ulna. Good interfragmentary compression is achieved as screws are perpendicular to the fracture line and two screws provide good rotational stability. Protection of fixation for 1014 days does not result in significant loss of range of motion. Further clinical and

  3. Strength of Rectangular Flat Plates Under Edge Compression

    NASA Technical Reports Server (NTRS)

    Schuman, Louis; Back, Goldie

    1931-01-01

    Flat rectangular plates of duralumin, stainless iron, monel metal, and nickel were tested under loads applied at two opposite edges and acting in the plane of the plate. The edges parallel to the direction of loading were supported in V grooves. The plates were all 24 inches long and varied in width from 4 to 24 inches by steps of 4 inches, and in thickness from 0.015 to 0.095 inch by steps of approximately 0.015 inch. There were also a few 1, 2, 3, and 6 inch wide specimens. The loads were applied in the testing machine at the center of a bar which rested along the top of the plate. Load was applied until the plate failed to take any more load. The tests show that the loads carried by the plates generally reached a maximum for the 8 or 12 inch width and that there was relatively small drop in load for the greater widths. Deflection and set measurement perpendicular to the plane of the plate were taken and the form of the buckle determined. The number of buckles were found to correspond in general to that predicted by the theory of buckling of a plate uniformly loaded at two opposite edges and simply supported at the edges.

  4. Failure mechanisms of composite plates with a circular hole under remote biaxial planar compressive loads

    SciTech Connect

    Khamseh, A.R.; Waas, A.M.

    1997-01-01

    The authors report the results of an experimental investigation carried out for the analysis of failure mechanisms in fibrous laminated composite plates containing stress raisers, in the form of circular cutouts, under static biaxial planar compressive loading (i.e., compression in the two inplane orthogonal directions). A series of biaxial tests were carried out with 48 ply graphite/epoxy composites of varying fiber orientation. In all cases, the hole diameter to plate with aspect ratio remained in a range suitable for infinite plate assumptions. Fiber microbuckling, fiber kink banding, and fiber/matrix debonding are identified as the dominant failure mechanisms.

  5. Is cannulated-screw fixation an alternative to plate osteosynthesis in open book fractures? A biomechanical analysis.

    PubMed

    Lázaro Gonzálvez, Ángel; Martínez Reina, Javier; Cano Luis, Pedro; Jiménez Baquero, Juan; Sueiro Fernández, José; Giráldez Sánchez, Miguel Ángel

    2016-09-01

    The current biomechanical work compares the symphyseal and sacroiliac stability obtained with two systems of bone osteosynthesis. The two methods of fixation compared were the 6-hole suprapubic non-locked plate and pubic fixation with two cannulated screws, a novel technique that can be applied percutaneously in the clinical practice. The aim of this study was to examine the validity of the use of two-cannulated-screws osteosynthesis in order to minimize the secondary effects of open fixation, especially in patients in whom an open reduction is contraindicated. A biomechanical study was designed in 9 fresh, human pelvis specimens, simulating an AO B1.1 type injury, using both fixation systems sequentially in each specimen. In both parts of the test, the specimens were subjected to an axial load of 300N. Displacements and rotations between the different pelvic elements were studied by means of a discrete set of points. The absence of differences between the two systems has been set as the null hypothesis. There were significant differences in favor of the cross-cannulated screws in most of the displacements measured at the pubic symphysis and sacroiliac joint. Fixation of the AO B1.1 type fractures with cross cannulated screws restores the biomechanical behavior of the pubic symphysis, obtaining better stability than fixation with the 6-hole non-locked plate. To date, no comparative, biomechanical studies have been conducted with these two systems of osteosynthesis. This study demonstrates that cross-cannulated screws fixation of the pubic symphysis in AO B1.1 pelvic fractures should be considered as an alternative to the conventional plating system. © 2016 Elsevier Ltd. All rights reserved.

  6. Simulated effect on the compressive and shear mechanical properties of bionic integrated honeycomb plates.

    PubMed

    He, Chenglin; Chen, Jinxiang; Wu, Zhishen; Xie, Juan; Zu, Qiao; Lu, Yun

    2015-05-01

    Honeycomb plates can be applied in many fields, including furniture manufacturing, mechanical engineering, civil engineering, transportation and aerospace. In the present study, we discuss the simulated effect on the mechanical properties of bionic integrated honeycomb plates by investigating the compressive and shear failure modes and the mechanical properties of trabeculae reinforced by long or short fibers. The results indicate that the simulated effect represents approximately 80% and 70% of the compressive and shear strengths, respectively. Compared with existing bionic samples, the mass-specific strength was significantly improved. Therefore, this integrated honeycomb technology remains the most effective method for the trial manufacturing of bionic integrated honeycomb plates. The simulated effect of the compressive rigidity is approximately 85%. The short-fiber trabeculae have an advantage over the long-fiber trabeculae in terms of shear rigidity, which provides new evidence for the application of integrated bionic honeycomb plates. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Compressive failure modes and parameter optimization of the trabecular structure of biomimetic fully integrated honeycomb plates.

    PubMed

    Chen, Jinxiang; Tuo, Wanyong; Zhang, Xiaoming; He, Chenglin; Xie, Juan; Liu, Chang

    2016-12-01

    To develop lightweight biomimetic composite structures, the compressive failure and mechanical properties of fully integrated honeycomb plates were investigated experimentally and through the finite element method. The results indicated that: fracturing of the fully integrated honeycomb plates primarily occurred in the core layer, including the sealing edge structure. The morphological failures can be classified into two types, namely dislocations and compactions, and were caused primarily by the stress concentrations at the interfaces between the core layer and the upper and lower laminations and secondarily by the disordered short-fiber distribution in the material; although the fully integrated honeycomb plates manufactured in this experiment were imperfect, their mass-specific compressive strength was superior to that of similar biomimetic samples. Therefore, the proposed bio-inspired structure possesses good overall mechanical properties, and a range of parameters, such as the diameter of the transition arc, was defined for enhancing the design of fully integrated honeycomb plates and improving their compressive mechanical properties.

  8. Theoretical Determination of Lifetime of Compressed Plates at Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Herrmann, George; Chu, Hu-Nan

    1959-01-01

    A method for the theoretical determination of the lifetime of com- pressed plates at elevated temperatures is presented. In this approach, linearized equations are used throughout with the assumption that the plate material is a standard linear solid. The critical time (lifetime) is determined by reducing the time-dependent behavior to the time- independent response of purely elastic buckling. Theoretically predicted lifetimes of 2024-T3 (formerly 24S-T3) aluminum-alloy plates at 450 F are compared with experimental values obtained in previous work.

  9. Surface properties of Indonesian-made narrow dynamic compression plates.

    PubMed

    Dewo, P; Sharma, P K; van der Tas, H F; van der Houwen, E B; Timmer, M; Magetsari, R; Busscher, H J; van Horn, J R; Verkerke, G J

    2008-07-01

    The enormous need of orthopaedic (surgical) implants such as osteosynthesis plates is difficult to be fulfilled in developing countries commonly rely on imported ones. One of the alternatives is utilization of local resources, but only after they have been proven safe to use, to overcome this problem. Surface properties are some of the determining factors of safety for those implants. We have succeeded in developing prototype of osteosynthesis plate and the results indicate that Indonesian-made plates need improvement with regards to the surface quality of physical characterization.

  10. Postbuckling of orthotropic composite plates loaded in compression

    NASA Technical Reports Server (NTRS)

    Stein, M.

    1982-01-01

    The nonlinear large deflection equations of von Karman are written for 'specially' orthotropic plates. The equations are then manipulated to determine the parameters required to establish postbuckling behavior. It is found that only two new parameters are needed beyond those required for buckling. By assuming trigonometric functions in one direction, the plate equations are converted into ordinary nonlinear differential equations which are solved numerically using a two point boundary problem solver that makes use of Newton's method. The postbuckling behavior is obtained for simply supported and clamped, long, rectangular, orthotropic plates covering the complete range of dimensions and material properties.

  11. Optimal Positioning for Volar Plate Fixation of a Distal Radius Fracture: Determining the Distal Dorsal Cortical Distance.

    PubMed

    Vosbikian, Michael M; Ketonis, Constantinos; Huang, Ronald; Ilyas, Asif M

    2016-01-01

    Distal radius fractures are currently among the most common fractures of the musculoskeletal system. With a population that is living longer, being more active, and the increasing incidence of osteoporosis, these injuries will continue to become increasingly prevalent. When operative fixation is indicated, the volar locking plate has recently become the treatment of choice. However, despite its success, suboptimal position of the volar locking plate can still result in radiographic loss of reduction. The distal dorsal cortical distance is being introduced as an intraoperative radiographic tool to help optimize plate position and minimize late loss of fracture reduction.

  12. Buckling and postbuckling behavior of square compression-loaded graphite-epoxy plates with circular cutouts

    NASA Technical Reports Server (NTRS)

    Nemeth, Michael P.

    1990-01-01

    An experimental study of the postbuckling behavior of square compression-loaded graphite-epoxy plates and isotropic plates with a central circular cutout is presented. Results are presented for unidirectional (0 sub 10)s and (90 sub 10)s plates, (0/90 sub 5)s plates, and for aluminum plates. Results are also presented for (+ or - O sub 6)s angle-ply plates for values of O = 30, 46, and 60 degrees. The experimental results indicate that the change in axial stiffness of a plate at buckling is strongly dependent upon cutout size and plate orthotropy. The presence of a cutout gives rise to an internal load distribution that changes, sometimes dramtically, as a function of cutout size coupled with the plate orthotropy. In the buckled state, the role of orthotropy becomes more significant since bending in addition to membrane orthotropy is present. Most of the plates with cutouts exhibited less postbuckling stiffness than the corresponding plate without a cutout, and the postbuckling stiffness decreased with increasing cutout size. However, some of the highly orthotropic plates with cutouts exhibited more postbuckling stiffness than the corresponding plate without a cutout.

  13. A Biomechanical Comparison of Locking Versus Conventional Plate Fixation for Distal Fibula Fractures in Trimalleolar Ankle Injuries.

    PubMed

    Nguyentat, Annie; Camisa, William; Patel, Sandeep; Lagaay, Pieter

    2016-01-01

    Previous biomechanical studies have advocated the use of locking plates for isolated distal fibula fractures in osteoporotic bone. Complex rotational ankle injuries involve an increased number of fractures, which can result in instability, potentially requiring the same fixed angle properties afforded by locking plates. However, the mechanical indication for locking plate technology has not been tested in this fracture model. The purpose of the present study was to compare the biomechanical properties of locking and conventional plate fixation for distal fibula fractures in trimalleolar ankle injuries. Fourteen (7 matched pairs) fresh-frozen cadaver leg specimens were used. The bone mineral density of each was obtained using dual x-ray absorptiometry scans. The fracture model simulated an OTA 44-B3.3 fracture. The syndesmosis was not disrupted. Each fracture was fixated in the same fashion, except for the distal fibula plate construct: locking (n = 7) and one-third tubular (n = 7). The specimens underwent axial and torsional cyclic loading, followed by torsional loading to failure. No statistically significant differences were found between the locking and conventional plate constructs during both fatigue and torque to failure testing (p > .05). Our specimen bone mineral density averages did not represent poor bone quality. The clinical implication of the present study is that distal fibular locking plates do not provide a mechanical advantage for trimalleolar ankle injuries in individuals with normal bone density and in the absence of fracture comminution.

  14. Buckling and postbuckling behavior of compression-loaded isotropic plates with cutouts

    NASA Technical Reports Server (NTRS)

    Nemeth, Michael P.

    1990-01-01

    An experimental study of buckling and postbuckling behavior of square and rectangular compression-loaded aluminum plates with centrally located circular, square, and elliptical cutouts is presented. Experimental results indicate that the plates exhibit overall trends of increasing buckling strain and decreasing initial postbuckling stiffness with increasing cutout width. Corresponding plates with circular and square cutouts of the same width buckle at approximately the same strain level, and exhibit approximately the same initial postbuckling stiffness. Results show that the reduction in initial postbuckling stiffness due to a cutout generally decreases as the plate aspect ratio increases. Other results presented in this paper indicate that square plates with elliptical cutouts having a large cutout-width-to-plate-width ratio generally lose prebuckling and initial postbuckling stiffness as the cutout height increases. However, the plates buckle at essentially the same strain level. Results also indicate that postbuckling stiffness is more sensitive to changes in elliptical cutout height than are prebuckling stiffness and buckling strain.

  15. Buckling and postbuckling behavior of compression-loaded isotropic plates with cutouts

    NASA Technical Reports Server (NTRS)

    Nemeth, Michael P.

    1990-01-01

    An experimental study of the buckling and postbuckling behavior of square and rectangular compression loaded aluminum plates with centrally located circular, square, and elliptical cutouts is presented. Experimental results indicate that the plates exhibit overall trends of increasing buckling strain and decreasing initial postbuckling stiffness with increasing cutout width. Corresponding plates with circular and square cutouts of the same width buckle at approximately the same strain level, and exhibit approximately the same initial postbuckling stiffness. Results show that the reduction in initial postbuckling stiffness due to a cutout generally decreases as the plate aspect ratio increases. Other results presented indicate that square plates with elliptical cutouts having a large cutout-width-to-plate-width ratio generally lose prebuckling and initial postbuckling stiffness as the cutout height increases. However, the plates buckle at essentially the same strain level. Results also indicate that postbuckling stiffness is more sensitive to changes in elliptical cutout height than are prebuckling stiffness and buckling strain.

  16. [Intramedullary locked fixation and compression nail (IP-XS-Nail): treatment of ankle joint fractures].

    PubMed

    Gehr, Jonas; Friedl, Wilhelm

    2006-06-01

    Reconstruction of the anatomy of the ankle joint while protecting the soft tissue, and osteosynthesis to maintain stability for function and weight bearing. Distal fractures of the fibula, bimalleolar fractures, and isolated fractures of the medial malleolus. Very small (< 5 mm) distal fragments (if fixation of the fragments is not possible using a small XXS nail) and very narrow (< 2.5 mm) medullary cavity (conversion to plate fixation). With displaced fibula fractures, open reduction should be performed with fracture retention using wide-armed reduction forceps, insertion of a central guide wire into the medullary cavity, use of a cannulated drill bit, introduction of the nail using an aiming arm and locked fixation with threaded wire. After checking the position using X-ray, the wire should be shortened using the bolt cutters. POSTOPERATIVE MANAGEMENT (Depending on the Weber classification): Full weight bearing for all isolated distal fractures of the fibula (Weber types A and B) and isolated fractures of the medial malleolus. For distal fractures of the fibula (Weber types A and B) with additional fracture of the medial malleolus or involvement of the medial ligament partial weight bearing of 20 kp for 4 weeks, followed by full weight bearing. For all Weber C fractures and/or additional Volkmann fracture only 10 kp of partial weight bearing with a rocker-sole orthosis should be allowed for 6 weeks followed by full weight bearing. No weight bearing for 6 weeks until the screws are removed is only recommended, if positioning screws have been used for Weber C fractures. In the period from 05/2000 to 01/2002, 194 ankle fractures were treated with the IP-XS-Nail((R)). Follow-up examinations were conducted on 162 patients with an average age of 51.2 years after an average of 15 months. 62 Weber B fractures (38.3%) and 45 Weber C fractures (27.7%) were evaluated. There were bimalleolar fractures in 55 cases (34.0%). According to the Olerud Score (clinical and

  17. Elastic and plastic buckling of simply supported solid-core sandwich plates in compression

    NASA Technical Reports Server (NTRS)

    Seide, Paul; Stowell, Elbridge Z

    1950-01-01

    A solution is presented for the problem of the compressive buckling of simply supported, flat, rectangular, solid-core sandwich plates stressed either in the elastic range or in the plastic range. Charts for the analysis of long sandwich plates are presented for plates having face materials of 24s-t3 aluminum alloy, 76s-t6 alclad aluminum alloy, and stainless steel. A comparison of computed and experimental buckling stresses of square solid-core sandwich plates indicates fair agreement between theory and experiment.

  18. Transfracture medial transposition of the radial nerve associated with plate fixation of the humerus.

    PubMed

    Chamseddine, Ali Hassan; Abdallah, Amer; Zein, Hadi; Taha, Assad

    2017-07-01

    The aim of this study was to illustrate safety, feasibility and advantages of transfracture medial transposition of the radial nerve during the lateral approach and lateral plating of humeral fractures located in the mid and distal shaft. This was a retrospective review and analysis of medical records and radiographs of 19 patients who underwent a transfracture medial transposition of the radial nerve. Fifteen patients were treated for fresh fracture and four for nonunion. All patients were followed up clinically and radiographically for a minimum of 12 months. Pre-operative radial nerve paralysis was present in four patients in the fresh fractures group; post-operative paralysis occurred in two. All patients completely recovered a few months after the index procedure. Except for two, all patients achieved bone healing. One patient from the fresh-fracture group developed nonunion, and one from the nonunion group experienced persistent nonunion; both underwent successful revision surgeries. In addition, four patients with a fresh fracture underwent revision surgery for hardware removal. All but two patients showed no restricted elbow or shoulder joint motion compared with the opposite side. Transfracture transposition of the radial nerve during open reduction and internal fixation of humeral shaft fractures is a safe, harmless and feasible procedure when applied for fractures of the middle and distal humeral shaft; it removes the nerve from the surgical field during fracture manipulation and fixation, with a gain in length of the nerve by transforming its course from spiral to straight. Following radial nerve transposition across the fracture, a repeat surgical approach to the humerus for hardware removal or treatment of nonunion transforms the procedure into a simple one; the skin incision is carried straight down to the bone without the need to identify or dissect the nerve that was previously transposed to the medial compartment of the arm.

  19. Clinical and radiological outcome after mini-open Latarjet technique with fixation of coracoid with Arthrex wedge mini-plate.

    PubMed

    Chaudhary, Deepak; Goyal, Ankit; Joshi, Deepak; Jain, Vineet; Mohindra, Mukul; Mehta, Nitin

    2016-01-01

    Technical faults leading to coracoid fractures during screw insertion and coracoid graft osteolysis are concerns with standard screw fixation techniques in Latarjet procedure. The purpose of this study is to share our experience using Arthrex wedge profile plate with mini-open technique for graft fixation, that ensures better load distribution between coracoid graft and glenoid. We did retrospective analysis of 24 patients with recurrent anterior shoulder instability after failed arthroscopic Bankart's repair. Arthroscopic examination of affected shoulder was done in lateral position before making patient supine for open Latarjet. A low profile wedge plate (Arthrex) with two screws was used for the procedure. CT analysis was performed post-operatively at 6 months to see graft union and results were evaluated using the Rowe and Walch Duplay score. Mean follow-up time was 26 months. Postoperatively, mean forward elevation was 170.6 + 4.6° (loss of average 5.9°) and mean external rotation was 42.5 + 5.3° (loss of average 3.1°). All patients returned to their previous occupation. None reported to be having any recurrent subluxation. Functional assessment done using Rowe score and Walch Duplay score showed statistically significant improvement (p value 0.034). There were no implant-related complications and no case of coracoid graft osteolysis. Mini-open Latarjet with graft fixation with Arthrex mini-plate provides satisfactory outcome in patients who require reoperation due to dramatic bone loss and failed soft tissue reconstruction. The modified incision improves exposure enabling plate fixation and the secure fixation accelerates rehabilitation.

  20. Clinical and radiological outcome after mini-open Latarjet technique with fixation of coracoid with Arthrex wedge mini-plate

    PubMed Central

    Chaudhary, Deepak; Goyal, Ankit; Joshi, Deepak; Jain, Vineet; Mohindra, Mukul; Mehta, Nitin

    2016-01-01

    Background Technical faults leading to coracoid fractures during screw insertion and coracoid graft osteolysis are concerns with standard screw fixation techniques in Latarjet procedure. The purpose of this study is to share our experience using Arthrex wedge profile plate with mini-open technique for graft fixation, that ensures better load distribution between coracoid graft and glenoid. Methods We did retrospective analysis of 24 patients with recurrent anterior shoulder instability after failed arthroscopic Bankart's repair. Arthroscopic examination of affected shoulder was done in lateral position before making patient supine for open Latarjet. A low profile wedge plate (Arthrex) with two screws was used for the procedure. CT analysis was performed post-operatively at 6 months to see graft union and results were evaluated using the Rowe and Walch Duplay score. Results Mean follow-up time was 26 months. Postoperatively, mean forward elevation was 170.6 + 4.6° (loss of average 5.9°) and mean external rotation was 42.5 + 5.3° (loss of average 3.1°). All patients returned to their previous occupation. None reported to be having any recurrent subluxation. Functional assessment done using Rowe score and Walch Duplay score showed statistically significant improvement (p value 0.034). There were no implant-related complications and no case of coracoid graft osteolysis. Conclusions Mini-open Latarjet with graft fixation with Arthrex mini-plate provides satisfactory outcome in patients who require reoperation due to dramatic bone loss and failed soft tissue reconstruction. The modified incision improves exposure enabling plate fixation and the secure fixation accelerates rehabilitation. PMID:26908972

  1. Currents of plate osteosynthesis in osteoporotic bone.

    PubMed

    Lampropoulou-Adamidou, Kalliopi; Karampinas, Panagiotis K; Chronopoulos, Efstathios; Vlamis, John; Korres, Demetrios S

    2014-05-01

    Osteoporotic fractures are becoming more prevalent with ageing of populations worldwide. Inadequate fixation or prolonged immobilization after non-surgical care leads to serious life-threatening events, poor functional results and lifelong disability. Thus, a stable internal fixation and rapid initiation of rehabilitation are required for faster return of function. Conventional internal fixation attempts to achieve the exact anatomy, often with extended soft-tissue stripping and compression of the periosteum, causing disturbance of the metaphyseal and comminuted fracture's bone blood supply. This technique relies on frictional forces between bone and plate. Osteoporotic bone might not be able to generate enough torque with the screw to securely fix the plate to bone. Thus, this surgical management have resulted in increased incidence of poor results in elderly, osteoporotic patients. The newly developed locked internal fixators, locking compression plates and less invasive stabilization system, consist of plate and screw systems where the screws are locked in the plate, minimizing the compressive forces exerted between plate and bone. Thus, the plate does not need to compress the bone nor requires precise anatomical contouring of a plate disturbing the periosteal blood supply. These fixators allowed the development of the minimal invasive percutaneous osteosynthesis. Nowadays, locking plates are the fixation method of choice for osteoporotic, diaphyseal or metaphyseal, severely comminuted fractures.

  2. Volar plate fixation of intra-articular distal radius fractures: a retrospective study.

    PubMed

    Fok, Margaret W M; Klausmeyer, Melissa A; Fernandez, Diego L; Orbay, Jorge L; Bergada, Alex Lluch

    2013-08-01

    Background Intra-articular fractures of the distal radius represent a therapeutic challenge as compared with the unstable extra-articular fractures. With the recent development of specifically designed internal fixation materials for the distal radius, treatment of these fractures by fragment-specific implants using two or more incisions has been advocated. Purpose The purpose of this study was to investigate the efficacy of a fixed-angle locking plate applied through a single volar approach in maintaining the radiographic alignment of unstable intra-articular fractures as well as to report the clinical outcomes. We only excluded those with massive comminution, as is discussed in greater detail in the text. Patients and Methods This is a multicentered, retrospective study involving three hospitals situated in Spain, Switzerland, and the United States. In the period between January 2000 and March 2006, 97 patients with 101 intra-articular distal radius fractures, including 13 volarly displaced and 88 dorsally angulated fractures were analyzed. Over 80% were C2/C3 fractures, based on the AO classification. 16 open fractures were noted. Results With an average follow-up of 28 months (range 24-70 months), the range of movement of the wrist was very satisfactory, and the mean grip strength was 81% of the opposite wrist. The Disabilities of the Arm, Shoulder, and Hand (DASH) score was 8. The complications rate was < 5%, including loss of reduction in two patients. All fractures healed by 3 months postinjury. Conclusions Irrespective of the direction and amount of initial displacement, a great majority of intra-articular fractures of the distal radius can be managed with a fixed-angle volar plate through a single volar approach. Level IV retrospective case series.

  3. A Study of the Efficiency of High-strength, Steel, Cellular-core Sandwich Plates in Compression

    NASA Technical Reports Server (NTRS)

    Johnson, Aldie E , Jr; Semonian, Joseph W

    1956-01-01

    Structural efficiency curves are presented for high-strength, stainless-steel, cellular-core sandwich plates of various proportions subjected to compressive end loads for temperatures of 80 F and 600 F. Optimum proportions of sandwich plates for any value of the compressive loading intensity can be determined from the curves. The efficiency of steel sandwich plates of optimum proportions is compared with the efficiency of solid plates of high-strength steel and aluminum and titanium alloys at the two temperatures.

  4. Failure mechanisms of uni-ply composite plates with a circular hole under static compressive loading

    NASA Technical Reports Server (NTRS)

    Khamseh, A. R.; Waas, A. M.

    1992-01-01

    The objective of the study was to identify and study the failure mechanisms associated with compressive-loaded uniply graphite/epoxy square plates with a central circular hole. It is found that the type of compressive failure depends on the hole size. For large holes with the diameter/width ratio exceeding 0.062, fiber buckling/kinking initiated at the hole is found to be the dominant failure mechanism. In plates with smaller hole sizes, failure initiates away from the hole edge or complete global failure occurs. Critical buckle wavelengths at failure are presented as a function of the normalized hole diameter.

  5. Video-assisted ALIF with cage and anterior plate fixation for L5-S1 spondylolisthesis.

    PubMed

    Aunoble, Stephane; Hoste, David; Donkersloot, Peter; Liquois, Frederic; Basso, Yann; Le Huec, Jean-Charles

    2006-10-01

    Spondylolysis and spondylolisthesis grade 0, 1, and 2 are mainly asymptomatic but with aging process and different factors some back pain can occur and lead to chronic low back pain. The conservative treatment with physiotherapy and steroid injection is the gold standard but in some cases is not efficient enough and a surgical treatment is proposed. The goal of this study is to propose a new technique to treat grade 0, 1, and 2 spondylolisthesis with an anterior video-assisted fusion and stabilization. Twenty patients with chronic low back pain since more than 2 years and resistant to conservative therapy were included in this protocol. Clinical signs and radicular pain were noted. They were evaluated preoperatively and postoperatively until the last follow up using Oswestry score and visual analog score (VAS) for leg and back pain. X-rays showed grade 0 (8 cases), 1 (10 cases), and 2 (2 cases) spondylolisthesis according to Meyerding classification with disc collapse (bulging disc). MRI showed in all cases a disc degeneration with at least black disc and/or endplates changes with Modic I or II. All patients were operated using an anterior video-assisted retroperitoneal approach, with discectomy and fusion using an anterior impacted cage filled with autologous cancellous bone from the iliac crest and an anterior fixation with a triangular plate (Pyramid, Medtronic, Memphis). The follow up at 3, 6, 12, and 24 months was done with clinical and radiologic evaluation. In case of problem a computed tomography scan was performed. There were 11 women and 9 men, with and average age of 39 years old and a BMI of 25.6. All spondylolistheses occurred at level L5. The average slippage was 19%. All L5S1 discs were black, 8 had a Modic I changes in the endplates and 2 had Modic II. The shape of L5 vertebra was abnormal (trapezoidal) in 7 cases. All anterior approaches were performed without vascular, urologic, or digestive complication. Blood loss was inferior to 100 mL. All

  6. Stability and Process of Destruction of Compressed Plate of Layered Composite Materials With Defects

    NASA Astrophysics Data System (ADS)

    Bokhoeva, L. A.; Rogov, V. E.; Chermoshentseva, A. S.; Lobanov, D. V.

    2016-08-01

    Interlayer defects in composite materials are a pressing problem, which affecting their performance characteristics. In this research, we considered the problem of the stability and of the fracture process of the compressed thin plate made of laminated composite materials with the interlayer defects. In this research we had got a critical equation for a plate with interlayer defect. The experiment showed the effect and the quantity of nano-dispersed additives on the mechanical properties of composite materials with interlayer defects.

  7. The outcome of super-cutaneous locked plate fixation with percutaneous reduction of displaced intra-articular calcaneal fractures.

    PubMed

    El-Desouky, Ihab I; Abu Senna, Wissam

    2017-02-01

    Supercutaneous (external) fixation with locking plate is utilized for fixation of long bone fractures. One retrospective study for open reduction and supercutaneous fixation of the calcaneus is reported. We prospectively evaluated the use of this method of fixation combined with percutaneous reduction. Between January 2014 and June 2015, 32 displaced calcaneus fractures in 30 patients were stabilized with percutaneous reduction and super-cutaneous fixation. They were 24 males and six females. The mean age was 37.9±5.7 years (21-55). All cases were closed. The time to surgery, complications, radiographic alignment, and time to radiographic union were recorded. Clinical results at the final follow-up were assessed by evaluating Bohler's angles for the radiographic alignment, and the system of the American Orthopedic Foot and Ankle Society (AOFAS) for the functional outcome. According to the Sanders' classification, two cases were type II, 17 cases were type III and 13 cases were type IV. The preoperative average Bohler's angle was 10.57°±4.8. The postoperative X-ray films demonstrated that the average Bohler's angle improved to 29.07°±5.9 (p<0.001). At the time of radiologic healing (about 3 months), the plates and screws were removed under general anesthesia. The average follow-up was 13.2 months (11-18). Four cases (type IV) showed mal-union and heel pain. According to (AOFAS) rating, the fine score was 87.1±17.1 points. Super-cutaneous fixation with percutaneous reduction of calcaneal fracture is an effective method in type II and III and can be effective with type IV but with less favorable results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. The biomechanical effect of bone quality and fracture topography on locking plate fixation in periprosthetic femoral fractures.

    PubMed

    Leonidou, Andreas; Moazen, Mehran; Lepetsos, Panagiotis; Graham, Simon M; Macheras, George A; Tsiridis, Eleftherios

    2015-02-01

    Optimal management of periprosthetic femoral fractures (PFF) around a well fixed prosthesis (Vancouver B1) remains controversial as adequate fixation needs to be achieved without compromising the stability of the prosthesis. The aim of this study was to highlight the effect of bone quality i.e. canal thickness ratio (CTR), and fracture topography i.e. fracture angle and its position in relation to the stem, on the biomechanics of a locking plate for a Vancouver B1 fracture. A previously corroborated simplified finite element model of a femur with a cemented total hip replacement stem was used in this study. Canal thickness ratio (CTR) and fracture topography were altered in several models and the effect of these variations on the von Mises stress on the locking plate as well as the fracture displacement was studied. Increasing the CTR led to reduction of the von Mises stress on the locking plate as well as the fracture movement. In respect to the fracture angle with the medial cortex, it was shown that acute angles resulted in lower von Mises stress on the plate as opposed to obtuse angles. Furthermore, acute fracture angles resulted in lower fracture displacement compared to the other fractures considered here. Fractures around the tip of the stem had the same biomechanical effect on the locking plate. However, fractures more distal to the stem led to subsequent increase of stress, strain, and fracture displacement. Results highlight that in good bone quality and acute fracture angles, single locking plate fixation is perhaps an appropriate management method. On the contrary, for poor bone quality and obtuse fracture angles alternative management methods might be required as the fixation might be under higher risk of failure. Clinical studies for the management of PFF are required to further support our findings.

  9. Operative Fixation of Chronic Acromioclavicular Joint Dislocation With Hook Plate and Modified Ligament Transfer.

    PubMed

    McKee, Michael D

    2016-08-01

    The optimal treatment for acute dislocation of the acromioclavicular (AC) joint remains unclear, and prior randomized trials did not reveal any significant improvements in the operative groups. However, it is clear that some patients treated nonoperatively are dissatisfied with their outcome and request surgical correction. This video demonstrates one method of repair of a chronic dislocation of the AC joint in a patient with significant symptomatology following nonoperative treatment of a high-grade AC dislocation. This video demonstrates the open reduction of a chronically dislocated AC joint. After mobilization of the distal clavicle and debridement of the joint, a step cut is made in the anterior surface of the distal clavicle. The coracoacromial (CA) ligament is then identified and mobilized, taking care to preserve its acromial origin. An anterior acromioplasty is then performed with a microsaggital saw. The AC joint is reduced, and the acromial fragment is sculpted to fit the step cut in the distal clavicle, where it is then fixed with a small-fragment cancellous screw in lag fashion. The blade of the hook plate is then contoured to fit under the acromion (posteriorly) to hold the joint in a reduced position. The deltoid is repaired with number 1 absorbable sutures, followed by a standard closure. Results are improved and complications minimized when care is taken to not avoid overreduction of the clavicle: an intraoperative radiograph, and/or comparison to the opposite side, may be useful. We do not shorten or resect the entire distal clavicle: this has been shown to lead to worse outcomes. We have found that CA transfer with a fragment of attached acromial bone results in more reliable healing than a CA transfer alone (the Weaver-Dunn transfer). In the setting of a chronic AC dislocation, hook plate fixation provides excellent reduction of the joint and a stable mechanical environment: this allows for the optimal healing of the ligament transfer. Typically

  10. Use of a Locked Fibular Plate for Fixation of a Vertical Shear Medial Malleolus Fracture: A Case Report.

    PubMed

    Blake, Sean; Yakubek, George; Shaer, James

    2015-01-01

    Vertical shear fractures of the medial malleolus are less common than transverse fractures. These fractures are often treated with lag screws, posteromedial buttress plating, antiglide plates, and neutralization plates with screws. We report on a 37-year-old male who had fractured his ankle after tripping and falling into a ditch. Initially, the patient was treated with closed reduction and a splint for a trimalleolar fracture with a laterally subluxed talus. However, on review of his preoperative radiographs and computed tomography studies, we confirmed a medial malleolus fracture with a vertical shear pattern and communition. Recently, a contoured fibular locking plate has been developed. We considered this plate to be effective for containing the bone in part because of its broader plate design. We present a case in which a fibular locking plate was used successfully as a neutralization plate as an alternative fixation method for a vertical shear medial malleolar fracture. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Radiographic outcomes of cable-plate versus cable-grip fixation in periprosthetic fractures of the proximal femur.

    PubMed

    Ricciardi, Benjamin F; Nodzo, Scott R; Oi, Kathryn; Lee, Yuo-Yu; Westrich, Geoffrey H

    2017-05-23

    Newer generation cable-plate designs are commonly used for periprosthetic proximal femur fractures; however, comparisons relative to cable-grips remain limited. The aim of this study was to compare radiographic healing rates of cable-plate versus cable-grip fixation for periprosthetic proximal femur fractures. Consecutive patients with an acute or chronic Vancouver A, B1, or B2 periprosthetic proximal femur fracture undergoing trochanteric fixation with a cable-plate (n = 46 cases) or cable-grip (n = 24 cases) system were identified retrospectively from a single-centre hospital database (mean follow-up 28 months [range 6-89 months]). Demographics, radiographic fracture healing, and complications were compared between the 2 groups. Radiographic union rates were not different between the cable-grip versus cable-plate group (67% vs. 76% respectively; p = 0.4). Healing rates of greater trochanteric fractures alone were not different between the cable-plate versus cable-grip groups (75% vs. 71% respectively; p = 0.38). The cable-plates were used for a more diverse range of fracture patterns relative to the cable-grips. An increased number of cables was associated with radiographic healing (odds ratio 14 [95% confidence interval 2-64]; p = 0.01), and body mass index had a negative correlation with radiographic healing (odds ratio -0.4 [95% confidence interval 0.5-0.9]. Similar rates of periprosthetic fracture healing were seen using a cable-grip versus cable-plate system; however, the cable-plate system could be used for a more diverse range of fracture patterns.

  12. Zygomatic complex fracture: A comparative evaluation of stability using titanium and bio-resorbable plates as one point fixation

    PubMed Central

    Tripathi, Nalini; Goyal, Manoj; Mishra, Brijesh; Dhasmana, Satish

    2013-01-01

    Background: The malar bone represents a strong bone on fragile support and its processes - frontal, orbital, maxillary and zygomatic are frequently the site of fracture. Current study was done to compare the stability of zygomatic complex fracture using Biodegradable plates and titanium miniplates with one point fixation. Materials and Methods: Twenty patients of zygomatic complex fracture were randomly selected and divided in two groups which were further divided into two subgroups (A, B). Group I patients were treated with titanium miniplate at zygomatic buttress and Group II was treated by bio-resorbable plates. One point fixation was done either at zygomatic buttress or at frontozygomatic suture and it was observed that both the site have been the most favored site of rigid internal fixation in terms of stability, aesthetics and prevention of rotation of the fracture segment in either vertical or horizontal axis. Conclusion: There is no significant difference in post operative outcomes between two groups, but still bioresorbable system has some advantage over titanium system as these plates resorbs over a period of time and does not cause any interference with growth and post operative radiotherapy. However application of biodegradable system demands highly précised technique. PMID:24665173

  13. Tracheal Tube Position Shift During Infant Resuscitation by Chest Compression: A Simulation Comparison by Fixation Method and With or Without Cuff.

    PubMed

    Ueno, Takeshi; Komasawa, Nobuyasu; Majima, Nozomi; Mihara, Ryosuke; Minami, Toshiaki

    2016-04-01

    Tracheal tube placement during infant resuscitation is essential for definite airway protection. Accidental extubation due to tracheal tube displacement is a rare event, but it results in severe complications, especially in infants. The present study evaluated how infant tracheal tube displacement is affected by tape vs. tube holder fixation using a manikin. A tracheal tube with internal diameter of 3.5 mm was placed 10 cm from the gum ridge in an advanced life support (ALS) Baby(®) simulator (Laerdal, Stavanger, Norway). In the first trial, cuff pressure was set at 15, 20, and 25 cmH2O and trials were performed at each setting with no fixation, Durapore(®) (3M, St Paul, MN) tape fixation, Multipore(®) (3M) tape fixation, and Thomas(®) Tube Holder (Laerdal) fixation. After 5 min of chest compression, the tracheal tube shift was measured. In the second trial, we compared the tube shift by chest compression with or without cuff in the same way. Relative to no fixation, tracheal tube shift was significantly less in the Durapore, Multipore, and tube holder groups (p < 0.05) at all cuff settings. Of the three fixation methods, the tube holder showed significantly less shift (p < 0.05) relative to tape, regardless of the initial cuff pressure. The positional shift after chest compressions was significantly larger in the trials with cuff than in those without cuff in Durapore or Multipore fixation (p < 0.05), but did not in tube holder fixation. There is less tracheal tube displacement with tube holder fixation than with tape during continuous infant chest compression simulation. The tube cuff can contribute to the positional shift of the tube during infant chest compression. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. FIXATION OF SUPRACONDYLAR FEMORAL FRACTURES: A BIOMECHANICAL ANALYSIS COMPARING 95° BLADE PLATES AND DYNAMIC CONDYLAR SCREWS (DCS)

    PubMed Central

    Percope Andrade, Marco Antônio; Rodrigues, André Soares; Mendonça, Celso Junio; Santos Portela, Luiz Gustavo

    2015-01-01

    Objective: To determine, by means of comparative biomechanical tests, whether greater compressive load resistance and flexion is presented by 95° angled blade plates or by dynamic condylar screws (DCS), and to correlate the failure type presented during the tests with each type of plate. Methods: Sixty-five porcine femurs were subjected to 1 cm medial wedge osteotomy, in the metaphysis, to simulate an unstable supracondylar femoral fracture. Osteosynthesis was performed on these pieces: 35 were fixed using 95° lateral blade plates and 30 with DCS plates. Another variable studied was the failure type presented in each group, in an attempt to correlate this with the type of plate. Results: There were no statistically significant differences in biomechanical resistance between the two types of plates, or between the failure type and the plate type used for the osteosynthesis. Conclusion: The two types of plate behaved in a similar fashion. However, the angled blade plate proved to be superior to the DCS in the flexion test. No statistical difference in failure type or type of plate used was observed. PMID:27022525

  15. A retrospective comparison of first metatarsophalangeal joint arthrodesis using a locked plate and compression screw technique.

    PubMed

    Hyer, Christopher F; Scott, Ryan T; Swiatek, Michael

    2012-10-01

    The historic primary treatment for end-stage first metatarsophalangeal (MTP) joint arthritis has been fusion. Traditionally, this has been accomplished by metaphyseal apposition between the proximal phalanx and metatarsal using crossed compression screws. Recently, locked plates have been introduced that help support this technique by offering added stability. We present our experience with 45 first MTP fusions in 45 feet using a locked plate and compression screw. A retrospective review of 45 patients who met the study criteria with a hallux rigidus correction using a locked plate with a compression screw was performed. Charts and radiographs were independently reviewed by 2 authors not involved in the index procedures to assess outcomes. There was a 93% fusion rate (42/45 feet) with 3 nonunions. The mean time to union was 51.1 days (range = 29-116 days, SD = 24.4). The mean patient age was 58.1 years (range = 29-80 years, SD = 10.1). The mean time to partial weight bearing was 7.0 days (range = 0-53 days, SD = 13.8) and the mean time to full weight bearing was 62.0 days (range = 29-57 days, SD = 17.9). We report on the results of first MTP fusion using a compression screw and locked plate technique. The results show that this is an effective means of creating a first MTP joint arthrodesis.

  16. Column and Plate Compressive Strength of Extruded XB75S-T Aluminum Alloy

    NASA Technical Reports Server (NTRS)

    Heimerl, George J.; Roy, J. Albert

    1944-01-01

    Results are presented of tests to determine the column and plate compressive strength of extruded XB75S-T aluminum alloy, and comparative values are shown for 24S-T aluminum-alloy sheet. Stress-strain curves are also given,

  17. TIBIOTARSAL COMPRESSION ARTHRODESIS USING A LATERAL LOCKING PLATE.

    PubMed

    Coughlin, Michael J; Nery, Caio; Baumfeld, Daniel; Jastifer, James

    2012-01-01

    Objetivos: A artrodese tibiotársica (TT) continua sendo uma importante opção no tratamento da artrose primária ou pós-traumática do tornozelo mas persiste ainda a controvérsia sobre o melhor método de fixação do foco de artrodese. Independentemente do tipo de material utilizado, o objetivo maior é a obtenção da fusão articular sólida, saudável e indolor. O propósito do presente estudo é apresentar os resultados preliminares de um novo sistema de placa bloqueada lateral compressiva para a artrodese do tornozelo. Método: Treze pacientes consecutivos portadores de artrose tibiotársica foram submetidos à artrodese do tornozelo nove pacientes eram homens e quatro mulheres. Com o auxílio de um guia, as superfícies articulares do talo e da tíbia foram decorticadas. Um sistema de compressão foi aplicado para evitar o alinhamento indesejável dos segmentos e uma placa bloqueada pré-moldada lateral foi utilizada para obter a fusão articular. Resultados: Tanto o escore AOFAS quanto o VAS melhoraram com a cirurgia. Todos os tornozelos operados consolidaram dentro do prazo de seis meses. Em todos os pacientes, foi obtido um ótimo alinhamento nos planos sagital, coronal e transverso. Conclusão: Acreditamos que a combinação de compressão bilateral, cortes ósseos com contornos pré-demarcados e placa lateral bloqueada, constitui uma técnica moderna, segura e útil para a artrodese do tornozelo.

  18. Are Biodegradable Plates Applicable in Endoscope-Assisted Open Reduction and Internal Fixation of Mandibular Subcondyle Fractures?

    PubMed

    Son, Jang-Ho; Ha, Jinhee; Cho, Yeong-Cheol; Sung, Iel-Yong

    2017-08-01

    To investigate whether biodegradable plates are applicable in endoscope-assisted open reduction and internal fixation (EAORIF) of mandibular subcondyle fractures. This retrospective case-series study included patients with mandibular subcondyle fractures treated with EAORIF using an unsintered hydroxyapatite particles/poly-l-lactide biodegradable plate system, with at least 6 months of clinical follow-up data available. The outcome variables were fracture healing with postoperative stability and postoperative complications. Other variables included age, gender, fracture site, cause of injury, accompanying mandibular fracture, total follow-up period, fracture classification, extent of displacement, preoperative status of occlusion, preoperative mandibular movements, fixation materials in accompanying mandibular fracture, location and number of fixation plates, periods of intermaxillary fixation/elastic bands, and postoperative mandibular movements. Fracture healing in these patients was assessed by comparing the immediate postoperative cone-beam computed tomography (CBCT) images with those obtained at least 3 months after surgery. A total of 11 patients, 9 male and 2 female, with a mean ± standard deviation age of 35.3 ± 15.9 years, were included. The mean follow-up period was 18.8 ± 7.8 months. Four patients had an accompanying mandibular fracture. Two 4-hole, 2.0-mm biodegradable plates were fixed with 6-mm screws along the posterior border of the mandibular ramus and near the sigmoid notch. Complete bone formation around the fracture lines or fading of the fracture lines, with no change in the position of the fractured segments, was observed on the postoperative CBCT images at 3 months. With the exception of 2 patients, no patient complained of plate palpability, deviation in occlusion, or discomfort during the postoperative follow-up period. EAORIF using biodegradable plates for mandible subcondylar fractures is a stable and reliable method, with

  19. Biomechanical analysis of expansion screws and cortical screws used for ventral plate fixation on the cervical spine

    PubMed Central

    Ullrich, Bernhard; Huber, Gerd; Morlock, Michael M.

    2009-01-01

    Compared to bicortical screws, the surgical risk of injuring intraspinal structures can be minimized with the use of monocortical screws. However, this reduction should not be achieved at the expense of the stability of the fixation. With monocortical stabilization, the expansion screws have the potential of absorbing high loads. Therefore, they are expected to be a suitable alternative to bicortical screws for revision surgeries and in osteoporotic bone. The purpose of this in vitro study was to investigate the stiffness of the two screw-plate systems used for ventral stabilization of the cervical spine, by focusing on the suitability of expansion screws as tools for revision treatments. The study was conducted in ten functional units of human cervical spines. The device sample stiffness was determined for four conditions using a turning moment of 2.25 N m each around one of the three principle axes. The conditions were native, destabilized, primarily stabilized with one of the screw-plate systems, followed by secondary stabilization using the expansion screw implant. The stabilized samples achieved a comparable, in most cases higher stiffness than the native samples. The samples undergoing secondary stabilization using expansion screws tend to display greater stiffness for all three axes compared to the primarily stabilized samples. The achieved tightening moment of the screws was higher than the one achieved with primary fixation. Both plates revealed similar primary stability. Revision surgeries with secondary instrumentation achieve a high stiffness of the screwed up segments. Monocortical expansion screws combined with a trapezoidal plate allow ventral stabilization of the cervical spine that is comparable to the plate fixation using bicortical screws. PMID:19588171

  20. The Locking Compression Paediatric Hip Plate: technical guide and critical analysis.

    PubMed

    Joeris, Alexander; Audigé, Laurent; Ziebarth, Kai; Slongo, Theddy

    2012-11-01

    Osteotomies of the proximal femur and stable fixation of displaced femoral neck fractures are demanding operations. An LCP Paediatric Hip Plate was developed to make these operations safer and less demanding. The article focuses on the surgical technique and critically analyses the device. Between 2006 and 2008, 30 hips in 22 patients underwent surgery. Patients' demographics, perioperative details, postoperative outcome and complications were retrospectively collected and analysed. Patients' diagnoses included persistent congenital hip dysplasia (n = 4), neuropathic hip dysplasia (n = 9), idiopathic ante/retroversion (n = 8), femoral neck fracture (n = 3), Perthes' disease (n = 2), deformity after slipped capital femoral epiphysis (SCFE), congenital femoral neck pseudarthrosis, deformity after pelvic tumour resection and malunion following proximal femoral fracture (one each). In 21 of 22 patients, the postoperative radiographs showed corrections as planned. Two cases had to be revised for screw loosening. Intraoperative handling using the plate was excellent in all cases. In our case series of 30 hip operations, the LCP Paediatric Hip Plate was shown to be safe and applicable in the clinical setting with excellent results and a low complication rate. We consider that the LCP Paediatric Hip Plate is a valuable device for correction of pathological conditions of the proximal femur and for fixation of displaced femoral neck fractures in children. Larger studies should be carried out to better quantify the risk of clinically relevant complications.

  1. Risk factors for failure of locked plate fixation of distal femur fractures: an analysis of 335 cases.

    PubMed

    Ricci, William M; Streubel, Philipp N; Morshed, Saam; Collinge, Cory A; Nork, Sean E; Gardner, Michael J

    2014-02-01

    Locked plating has become a standard method to treat supracondylar femur fractures. Emerging evidence indicates that this method of treatment is associated with modest failure rates. The goals of this study were to determine risk factors for complications and to provide technical recommendations for locked plating of supracondylar femur fractures. Retrospective review. Three level I or II trauma centers. Three hundred twenty-six patients with 335 distal femur fractures (OTA 33A or C, 33% open) treated with lateral locked plates were studied. The average patient age was 57 years (range 17-97 years), 55% were women, 34% were obese, 19% were diabetic, and 24% were smokers. All patients were managed with open reduction internal fixation using a lateral distal femoral locked plate construct that included locked screws in the distal fragment and nonlocked, locked, or a combination of locked and nonlocked screws in the proximal fragment. Risk factors for reoperation to promote union, deep infection, and implant failure. After the index procedure, 64 fractures (19%) required reoperation to promote union, including 30 that had a planned staged bone grafting because of the metaphyseal defect after debridement of an open fracture. Independent risk factors for reoperation to promote union and deep infection included diabetes and open fracture. Risk factors for proximal implant failure included open fracture, smoking, increased body mass index, and shorter plate length. The identified risk factors for reoperation to promote union and complications included open fracture, diabetes, smoking, increased body mass index, and shorter plate length. Most factors are out of surgeon control but are useful when considering prognosis. Use of relatively long plates is a technical factor that can reduce risk for fixation failure. Prognostic level II. See instructions for authors for a complete description of levels of evidence.

  2. Damage Progression in Buckle-Resistant Notched Composite Plates Loaded in Uniaxial Compression

    NASA Technical Reports Server (NTRS)

    McGowan, David M.; Davila, Carlos G.; Ambur, Damodar R.

    2001-01-01

    Results of an experimental and analytical evaluation of damage progression in three stitched composite plates containing an angled central notch and subjected to compression loading are presented. Parametric studies were conducted systematically to identify the relative effects of the material strength parameters on damage initiation and growth. Comparisons with experiments were conducted to determine the appropriate in situ values of strengths for progressive failure analysis. These parametric studies indicated that the in situ value of the fiber buckling strength is the most important parameter in the prediction of damage initiation and growth in these notched composite plates. Analyses of the damage progression in the notched, compression-loaded plates were conducted using in situ material strengths. Comparisons of results obtained from these analyses with experimental results for displacements and axial strains show good agreement.

  3. Meta-analysis for dorsally displaced distal radius fracture fixation: volar locking plate versus percutaneous Kirschner wires.

    PubMed

    Zong, Shuang-Le; Kan, Shi-Lian; Su, Li-Xin; Wang, Bin

    2015-07-15

    Dorsally displaced distal radius fractures (DDDRF) are frequent injuries in clinical practice. Traditional percutaneous Kirschner wires (K-wire) and open reduction with volar locking plate (VLP) are the two most common surgical fixation techniques used to manage DDDRF. However, there is no current consensual evidence to guide the selection of one technique over the other. Therefore, we undertook a systematic search and meta-analysis to compare clinical outcomes and complications of these two treatment approaches for DDDRF. The following electronic databases were searched by two independent reviewers, up to April 2015: PubMed, ScienceDirect and Wiley Online Library. High-quality randomized controlled trials (RCTs) comparing VLP and percutaneous K-wire fixation for DDDRF were identified. Pooled mean differences were calculated for the following continuous outcome variables: disabilities of the arm, shoulder and hand (DASH) score, grip strength and wrist range of motion. Pooled odds ratios were calculated for rates of total postoperative complications, including superficial infection, deep infection, complex regional pain syndrome (CRPS), carpal tunnel syndrome (CTS), neurological injury, tendon rupture, tenosynovitis, loss of reduction and additional surgery to remove hardware. The meta-analysis was completed using RevMan 5.3 software. Seven RCTs, with a total of 875 patients, were included in our meta-analysis. Open reduction internal fixation (ORIF) with VLP fixation provided statistically lower DASH scores, reduced the incidence of total postoperative complications and specifically lowered the rate of superficial infection, when compared, over a 1-year follow-up, to percutaneous K-wire fixation. VLP fixation also provided significantly better grip strength and range of wrist flexion and supination in the early 6-month postoperative period, compared with percutaneous K-wire fixation. ORIF with VLP fixation provided lower DASH scores and reduced total postoperative

  4. Hook plate fixation for acute acromioclavicular dislocations without coracoclavicular ligament reconstruction: a functional outcome study in military personnel.

    PubMed

    Kumar, Narinder; Sharma, Vyom

    2015-08-01

    The aim of our study was to evaluate the shoulder function after clavicular hook plate fixation of acute acromioclavicular dislocations (Rockwood type III) in a population group consisting exclusively of high-demand military personnel. This prospective study was carried out at a tertiary care military orthopaedic centre during 2012-2013 using clavicular hook plate for management of acromioclavicular injuries without coracoclavicular ligament reconstruction in 33 patients. All patients underwent routine implant removal after 16 weeks. The functional outcome was assessed at 3, 6 and 12 months after hook plate removal and 2 years from the initial surgery using the Constant Murley and UCLA Scores. All the patients were male serving soldiers and had sustained acromioclavicular joint dislocation (Rockwood type III). Mean age of the patient group was 34.24 years (21-55 years). The mean follow-up period in this study was 23.5 months (20-26 months) after hook plate fixation and an average of 19.9 months (17-22 months) after hook plate removal. The average Constant Score at 3 months after hook plate removal was 60.3 as compared to 83.7 and 90.3 at 6 months and 1 year, respectively, and an average of 91.8 at the last follow-up that was approximately 2 years after initial surgery which was statistically significant (p value <0.05). The UCLA Score was an average of 15.27, 25.9 and 30.1 at 3, 6 months and 1 year, respectively, after removal of hook plate which improved further an average of 32.3 at the last follow-up, which was also statistically significant (p value <0.05). Clavicular hook plate fixation without coracoclavicular ligament reconstruction is a good option for acute acromioclavicular dislocations producing excellent medium-term functional results in high-demand soldiers.

  5. The effect of posterior spinal fixation with acrylic cement on the vertebral growth plate and intervertebral disc in dogs.

    PubMed

    Moon, M S; Ok, I Y; Ha, K Y

    1986-01-01

    We have attempted to clarify the serial histological changes in the growing spine of dogs following posterior fixation with acrylic cement. Twenty-four male mongrel dogs aged 8 weeks were used for the study. The lumbar spine from L.3 to L.5 was fixed posteriorly with acrylic cement. Three dogs were then sacrificed every four weeks up to 32 weeks, and the histological changes of the vertebral disc, growth plate and vertebral bodies were observed by light microscopy. Thinning of the growth plate and distortion of the cartilage columns has been demonstrated, but premature fusion of the growth plate did not result and vertebral body growth continued. Anterior wedging of the intervertebral disc was seen with some thinning of the bony trabeculae of the vertebral body. Degeneration of the nucleus pulposus resulted, with replacement by fibrous tissue. The normal horizontal arrangement of the fibres of the annulus fibrosus altered to a vertical configuration by 32 weeks.

  6. Internal fixation of complex fractures of the tarsal navicular with locking plates. A report of 10 cases.

    PubMed

    Cronier, P; Frin, J-M; Steiger, V; Bigorre, N; Talha, A

    2013-06-01

    Tarsal navicular fractures are rare and treatment of comminuted fractures is especially difficult. Since 2007, the authors have had access to 3D reconstruction from CT scan images and specific locking plates, and they decided to evaluate whether these elements improved management of these severe cases. Between 2007 and 2011, 10 comminuted tarsal navicular fractures were treated in a prospective study. All of the fractures were evaluated by 3D reconstruction from CT scan images, with suppression of the posterior tarsal bones. The surgical approach was chosen according to the type of lesion. Reduction was achieved with a mini-distractor when necessary, and stabilized by AO locking plate fixation (Synthes™). Patient follow-up included a clinical and radiological evaluation (Maryland Foot score, AOFAS score). Eight patients underwent postoperative CT scan. All patients were followed up after a mean 20.5 months. Union was obtained in all patients and arthrodesis was not necessary in any of them. The mean Maryland Foot score was 92.8/100, and the AOFAS score 90.6/100. One patient with an associated comminuted calcaneal fracture had minimal sequella from a compartment syndrome of the foot. The authors did not find any series in the literature that reported evaluating tarsal navicular fractures by 3D reconstruction from CT scan images. The images obtained after suppression of the posterior tarsal bones systematically showed a lateral plantar fragment attached to the plantar calcaneonavicular ligament, which is essential for stability, and which helped determine the reduction technique. Locking plate fixation of these fractures has never been reported. Comminuted fractures of the tarsal navicular were successfully treated with specific imaging techniques in particular 3D reconstructions of CT scan images to choose the surgical approach and the reduction technique. Locking plate fixation of the navicular seems to be a satisfactory solution for the treatment of these

  7. Observation of the initiation and progression of damage in compressively loaded composite plates containing a cutout

    NASA Technical Reports Server (NTRS)

    Waas, A.; Babcock, C., Jr.

    1986-01-01

    A series of experiments was carried out to determine the mechanism of failure in compressively loaded laminated plates with a circular cutout. Real time holographic interferometry and photomicrography are used to observe the progression of failure. These observations together with post experiment plate sectioning and deplying for interior damage observation provide useful information for modelling the failure process. It is revealed that the failure is initiated as a localised instability in the zero layers, at the hole surface. With increasing load extensive delamination cracking is observed. The progression of failure is by growth of these delaminations induced by delamination buckling. Upon reaching a critical state, catastrophic failure of the plate is observed. The levels of applied load and the rate at which these events occur depend on the plate stacking sequence.

  8. In situ deformation of growth plate chondrocytes in stress-controlled static vs dynamic compression.

    PubMed

    Zimmermann, Elizabeth A; Bouguerra, Séréna; Londoño, Irene; Moldovan, Florina; Aubin, Carl-Éric; Villemure, Isabelle

    2017-03-11

    Longitudinal bone growth in children/adolescents occurs through endochondral ossification at growth plates and is influenced by mechanical loading, where increased compression decreases growth (i.e., Hueter-Volkmann Law). Past in vivo studies on static vs dynamic compression of growth plates indicate that factors modulating growth rate might lie at the cellular level. Here, in situ viscoelastic deformation of hypertrophic chondrocytes in growth plate explants undergoing stress-controlled static vs dynamic loading conditions was investigated. Growth plate explants from the proximal tibia of pre-pubertal rats were subjected to static vs dynamic stress-controlled mechanical tests. Stained hypertrophic chondrocytes were tracked before and after mechanical testing with a confocal microscope to derive volumetric, axial and lateral cellular strains. Axial strain in hypertrophic chondrocytes was similar for all groups, supporting the mean applied compressive stress's correlation with bone growth rate and hypertrophic chondrocyte height in past studies. However, static conditions resulted in significantly higher lateral (p<0.001) and volumetric cellular strains (p≤0.015) than dynamic conditions, presumably due to the growth plate's viscoelastic nature. Sustained compression in stress-controlled static loading results in continued time-dependent cellular deformation; conversely, dynamic groups have less volumetric strain because the cyclically varying stress limits time-dependent deformation. Furthermore, high frequency dynamic tests showed significantly lower volumetric strain (p=0.002) than low frequency conditions. Mechanical loading protocols could be translated into treatments to correct or halt progression of bone deformities in children/adolescents. Mimicking physiological stress-controlled dynamic conditions may have beneficial effects at the cellular level as dynamic tests are associated with limited lateral and volumetric cellular deformation.

  9. The search for the ideal fixation of palatal fractures: innovative experience with a mini-locking plate.

    PubMed

    Pollock, Richard A

    2008-11-01

    Fractures of the palate have defied conventional management, such that malrotation and disinclination of the palatal shelves occur in a significant number of patients after repair. The fractured palatal shelves of eight patients were first prealigned. To do so, one or more 205-mm ratchet clamps and two intermaxillary fixation (IMF) posts were used. Rigid fixation was then achieved by applying a 2.0-mm mini-locking titanium plate (across the palatal vault) and by applying an adaptation miniplate across the fracture line as it exited the anterior surface of the maxilla. Screws were passed directly through the mucoperiosteum, to engage the palatal shelves and to lock the locking plate into position. Lacerations in the mucoperiosteum were neither used to aid fixation nor used as portals for dissection; incisions and mucoperiosteal flaps in the palatal vault were avoided. Adjuncts, such as intraoral splints, have not been used in cases to date, and early mobilization was allowed. Reconstitution of the craniomaxillofacial buttresses was added in patients with more extensive maxillary injury. The palatal appliance and screws remained rigidly in position in the roof of the mouth, much like an external fixator, until their removal 8 to 12 weeks after the repair. No patient suffered erosion of the mucoperiosteum or other major morbidity, other than a transient fistula of the soft palate. The palatoalveolar segments remained in proper realignment and inclination, and pretraumatic occlusal patterns and the width and depth of the lower face appear to have been restored with one exception. The latter suffered a subtle posterolateral open bite that was corrected orthodontically. Prealignment of fractured palatal shelves with one or more large ratchet clamps and two IMF posts provides several points of forced reduction of the palatal shelves, along the dental arch. In addition, stabilization with mini-locking plate(s) in the palatal vault and an adaptation plate across the

  10. Radiographic and clinical results of tension suture fixation using two washers with PHILOS plate for proximal humeral fractures.

    PubMed

    Cho, Chul-Hyun; Kim, Du Han; Kim, Beom-Soo

    2017-02-01

    The purpose of this study was to evaluate the radiographic and clinical results of tension suture fixation using two washers with PHILOS plate (Synthes, West Chester, PA, USA) for proximal humeral fractures. Consecutive 39 patients were included and divided into two groups of adequate and inadequate medial support (MS (+) group vs MS (-) group). The mean follow-up period was 45months (range: 26-69 months). The mean age at the time of surgery was 59 years (range: 17-86 years) and there were 12 men and 27 women. The clinical results were evaluated using the visual analogue scale (VAS) pain score, American Shoulder and Elbow Surgeons (ASES) score, and subjective shoulder value (SSV). The radiographic results were evaluated by serial radiographs and Paavolainen method, which measures the neck-shaft angle (NSA). We used the Paired T and Kruskal-Wallis test to compare radiographic and clinical results between the two groups. Bony union was achieved in 37 cases (94.9%). The mean NSA was changed from 133.5° postoperatively to 131.0° at the final follow-up period, but this change was not statistically significant. Thirty-five cases (89.8%) had good radiographic results as determined by the Paavolainen method. The mean final VAS pain score, ASES score, and SSV were 1.3, 87.3, and 86.0%, respectively. There were no significant differences between the two groups with respect to radiographic and clinical outcomes. Eight cases (20.5%) had complications including 5 with shoulder stiffness, 1 experiencing nonunion by fixation failure, 1 malunion, and 1 migration of greater tuberosity. Tension suture fixation using two washers with PHILOS plate for proximal humeral fractures yielded satisfactory radiographic and clinical results. It can be a treatment option that can reduce varus deformity and fixation loss. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Cuttable plate fixation for small breed dogs with radius and ulna fractures: Retrospective study of 31 dogs.

    PubMed

    Watrous, Gwyneth K; Moens, Noel M M

    2017-04-01

    This retrospective study evaluated complication rates for radius and ulna fractures in small breed dogs in which 1.5 mm to 2.7 mm cuttable bone plates were used for internal fixation. The medical records of all cases from 2004 to 2011 that were presented to our clinic were reviewed. Inclusion criteria were: dogs with body weight < 9 kg, fracture of the radius and ulna with open reduction, and internal fixation utilizing a cuttable bone plate. Thirty-four fractures in 31 dogs met the inclusion criteria. Of 25 dogs that were available for follow-up, all achieved union, minor complications occurred in 9, and major complications occurred in 8. External coaptation was responsible for complications in 8 cases and the need for coaptation needs to be investigated. Excluding minor complications, 32% of patients required at least 1 additional surgery or additional hospitalization. All but 2 of the dogs returned to full function. The 1.5 mm straight plate was successfully used in all dogs with a body weight of 0.9 to 2.6 kg.

  12. Evaluation of a new approach for modelling the screw-bone interface in a locking plate fixation: a corroboration study.

    PubMed

    Moazen, Mehran; Mak, Jonathan H; Jones, Alison C; Jin, Zhongmin; Wilcox, Ruth K; Tsiridis, Eleftherios

    2013-07-01

    Computational modelling of the screw-bone interface in fracture fixation constructs is challenging. While incorporating screw threads would be a more realistic representation of the physics, this approach can be computationally expensive. Several studies have instead suppressed the threads and modelled the screw shaft with fixed conditions assumed at the screw-bone interface. This study assessed the sensitivity of the computational results to modelling approaches at the screw-bone interface. A new approach for modelling this interface was proposed, and it was tested on two locking screw designs in a diaphyseal bridge plating configuration. Computational models of locked plating and far cortical locking constructs were generated and compared to in vitro models described in prior literature to corroborate the outcomes. The new approach led to closer agreement between the computational and the experimental stiffness data, while the fixed approach led to overestimation of the stiffness predictions. Using the new approach, the pattern of load distribution and the magnitude of the axial forces, experienced by each screw, were compared between the locked plating and far cortical locking constructs. The computational models suggested that under more severe loading conditions, far cortical locking screws might be under higher risk of screw pull-out than the locking screws. The proposed approach for modelling the screw-bone interface can be applied to any fixation involved application of screws.

  13. Behavior of a plate strip under shear and compressive stresses beyond the buckling limit

    NASA Technical Reports Server (NTRS)

    Kromm, A; Marguerre, K

    1938-01-01

    The present report is an extension of previous theoretical investigations on the elastic behavior of a plate under compression and shear in the region above the critical. The main object is the clarification of the behavior immediately above the buckling limit since no theoretical expressions for this range have thus far been found and since experimentally, too, any degree of regularity in the behavior of the plate in the range between the critical load and about three to four times the critical, is discernible only with difficulty.

  14. A biomechanical comparison of proximal femoral nails and locking proximal anatomic femoral plates in femoral fracture fixation

    PubMed Central

    Ozkan, Korhan; Türkmen, İsmail; Sahin, Adem; Yildiz, Yavuz; Erturk, Selim; Soylemez, Mehmet Salih

    2015-01-01

    Background: The incidence of fractures in the trochanteric area has risen with the increasing numbers of elderly people with osteoporosis. Although dynamic hip screw fixation is the gold standard for the treatment of stable intertrochanteric femur fractures, treatment of unstable intertrochanteric femur fractures still remains controversial. Intramedullary devices such as Gamma nail or proximal femoral nail and proximal anatomic femur plates are in use for the treatment of intertrochanteric femur fractures. There are still many investigations to find the optimal implant to treat these fractures with minimum complications. For this reason, we aimed to perform a biomechanical comparison of the proximal femoral nail and the locking proximal anatomic femoral plate in the treatment of unstable intertrochanteric fractures. Materials and Methods: Twenty synthetic, third generation human femur models, obtained for this purpose, were divided into two groups of 10 bones each. Femurs were provided as a standard representation of AO/Orthopedic Trauma Associationtype 31-A2 unstable fractures. Two types of implantations were inserted: the proximal femoral intramedullary nail in the first group and the locking anatomic femoral plate in the second group. Axial load was applied to the fracture models through the femoral head using a material testing machine, and the biomechanical properties of the implant types were compared. Result: Nail and plate models were locked distally at the same level. Axial steady load with a 5 mm/m velocity was applied through the mechanical axis of femur bone models. Axial loading in the proximal femoral intramedullary nail group was 1.78-fold greater compared to the plate group. All bones that had the plate applied were fractured in the portion containing the distal locking screw. Conclusion: The proximal femoral intramedullary nail provides more stability and allows for earlier weight bearing than the locking plate when used for the treatment of

  15. UK DRAFFT - A randomised controlled trial of percutaneous fixation with kirschner wires versus volar locking-plate fixation in the treatment of adult patients with a dorsally displaced fracture of the distal radius

    PubMed Central

    2011-01-01

    Background Fractures of the distal radius are extremely common injuries in adults. However, the optimal management remains controversial. In general, fractures of the distal radius are treated non-operatively if the bone fragments can be held in anatomical alignment by a plaster cast or orthotic. However, if this is not possible, then operative fixation is required. There are several operative options but the two most common in the UK, are Kirschner-wire fixation (K-wires) and volar plate fixation using fixed-angle screws (locking-plates). The primary aim of this trial is to determine if there is a difference in the Patient-Reported Wrist Evaluation one year following K-wire fixation versus locking-plate fixation for adult patients with a dorsally-displaced fracture of the distal radius. Methods/design All adult patients with an acute, dorsally-displaced fracture of the distal radius, requiring operative fixation are potentially eligible to take part in this study. A total of 390 consenting patients will be randomly allocated to either K-wire fixation or locking-plate fixation. The surgery will be performed in trauma units across the UK using the preferred technique of the treating surgeon. Data regarding wrist function, quality of life, complications and costs will be collected at six weeks and three, six and twelve months following the injury. The primary outcome measure will be wrist function with a parallel economic analysis. Discussion This pragmatic, multi-centre trial is due to deliver results in December 2013. Trial registration Current Controlled Trials ISRCTN31379280 UKCRN portfolio ID 8956 PMID:21914196

  16. UK DRAFFT - a randomised controlled trial of percutaneous fixation with kirschner wires versus volar locking-plate fixation in the treatment of adult patients with a dorsally displaced fracture of the distal radius.

    PubMed

    Costa, Matthew L; Achten, Juul; Parsons, Nick R; Rangan, Amar; Edlin, Richard P; Brown, Jaclyn; Lamb, Sarah E

    2011-09-13

    Fractures of the distal radius are extremely common injuries in adults. However, the optimal management remains controversial. In general, fractures of the distal radius are treated non-operatively if the bone fragments can be held in anatomical alignment by a plaster cast or orthotic. However, if this is not possible, then operative fixation is required. There are several operative options but the two most common in the UK, are Kirschner-wire fixation (K-wires) and volar plate fixation using fixed-angle screws (locking-plates). The primary aim of this trial is to determine if there is a difference in the Patient-Reported Wrist Evaluation one year following K-wire fixation versus locking-plate fixation for adult patients with a dorsally-displaced fracture of the distal radius. All adult patients with an acute, dorsally-displaced fracture of the distal radius, requiring operative fixation are potentially eligible to take part in this study. A total of 390 consenting patients will be randomly allocated to either K-wire fixation or locking-plate fixation. The surgery will be performed in trauma units across the UK using the preferred technique of the treating surgeon. Data regarding wrist function, quality of life, complications and costs will be collected at six weeks and three, six and twelve months following the injury. The primary outcome measure will be wrist function with a parallel economic analysis. This pragmatic, multi-centre trial is due to deliver results in December 2013. Current Controlled Trials ISRCTN31379280 UKCRN portfolio ID 8956.

  17. Comparison of postoperative changes in the distal and proximal segments between conventional and sliding mini-plate fixation following mandibular setback

    PubMed Central

    Kim, Seong-Sik; Kwak, Kyoung-Ho; Ko, Ching-Chang; Park, Soo-Byung; Son, Woo-Sung

    2016-01-01

    Objective The purpose of the present study was to evaluate the postoperative three-dimensional (3D) changes in the proximal segments after mandibular setback sagittal split ramus osteotomy and to compare the changes between the conventional mini-plate fixation and semi-rigid sliding plate fixation. Methods Cone-beam computed tomography (CBCT) images were used to evaluate the postoperative 3D changes in the proximal segments during the healing process. CBCT images were superimposed using the symphysis and the lower anterior mandible as references. Results There were no statistically significant differences between the conventional mini-plate and semi-rigid sliding plate groups (p > 0.05). With respect to the distribution of changes greater than 2 mm in the landmarks, the right condylion, right coronoid process, and left condylion showed ratios of 55.6%, 50.0%, and 44.4%, respectively, in the semi-rigid sliding plate group; however, none of the landmarks showed ratios greater than 30% in the conventional mini-plate group. Conclusions There were no statistically significant differences in postoperative changes in the segments between the conventional mini-plate and semi-rigid sliding plate groups. Nevertheless, while selecting the type of fixation technique, clinicians should consider that landmarks with greater than 2 mm changes were higher in the semi-rigid sliding plate group than in the conventional mini-plate group. PMID:27896211

  18. Which parameters affect medium- to long-term results after angular stable plate fixation for proximal humeral fractures?

    PubMed

    Bahrs, Christian; Kühle, Luise; Blumenstock, Gunnar; Stöckle, Ulrich; Rolauffs, Bernd; Freude, Thomas

    2015-05-01

    Very little information on medium- to long-term results is available for surgically treated proximal humeral fractures. The aim of this prospective treatment study was to present long-term results after angular stable plate fixation of displaced proximal humeral fractures and to detect which specific patient- and fracture-related parameters affect the clinical outcome. We performed a prospective clinical and radiologic evaluation of 77 patients with a displaced proximal humeral fracture (28 Neer 2-part, 38 3-part, and 11 4-part fractures; 28 AO A fractures, 30 AO B fractures, and 19 AO C fractures) treated with angular stable plate fixation after a mean follow-up period of 96 months (range, 74-133 months). We assessed outcomes with the Constant, University of California-Los Angeles (UCLA), and Disabilities of the Arm, Shoulder, and Hand (DASH) scores and evaluated specific patient- and fracture-related parameters including complications. The mean Constant, University of California-Los Angeles (UCLA), and Disabilities of the Arm, Shoulder, and Hand (DASH) scores were 79, 31, and 12 points. Reasons for revisions were implant-related impingement (n = 13), screw perforation (n = 10), infection (n = 4), and secondary fracture displacement (n = 1). There was a significant association between worse score results and occurrence of secondary fracture displacement, screw perforation, residual bone deformities, and a rotator cuff defect at follow-up. Good medium- to long-term results after angular stable plate fixation of displaced proximal humeral fracture can be expected. A reconstruction within a range of 15° in both anteroposterior and axillary views and <5-mm tuberosity displacement should be the aim of head-preserving surgery to prevent complications, such as secondary fracture displacement and screw perforation, and a less favorable long-term result. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights

  19. Compression failure mechanisms of uni-ply composite plates with a circular cutout

    NASA Technical Reports Server (NTRS)

    Khamseh, A. R.; Waas, A. M.

    1992-01-01

    The effect of circular-hole size on the failure mode of uniply graphite-epoxy composite plates is investigated experimentally and analytically for uniaxial compressive loading. The test specimens are sandwiched between polyetherimide plastic for nondestructive evaluations of the uniply failure mechanisms associated with a range of hole sizes. Finite-element modeling based on classical lamination theory is conducted for the corresponding materials and geometries to reproduce the experimental results analytically. The type of compressive failure is found to be a function of hole size, with fiber buckling/kinking at the hole being the dominant failure mechanism for hole diam/plate width ratios exceeding 0.062. The results of the finite-element analysis supported the experimental data for these failure mechanisms and for those corresponding to smaller hole sizes.

  20. Investigation of the Compressive Strength and Creep Lifetime of 2024-T3 Aluminum-Alloy Plates at Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Mathauser, Eldon E; Deveikis, William D

    1957-01-01

    The results of elevated-temperature compressive strength and creep tests of 2024-t3 (formerly 24s-t3) aluminum alloy plates supported in v-grooves are presented. The strength-test results indicate that a relation previously developed for predicting plate compressive strength for plates of all materials at room temperature is also satisfactory for determining elevated-temperature strength. Creep-lifetime results are presented for plates in the form of master creep-lifetime curves by using a time-temperature parameter that is convenient for summarizing tensile creep-rupture data. A comparison is made between tensile and compressive creep lifetime for the plates and a method that made use of isochronous stress-strain curves for predicting plate-creep failure stresses is investigated.

  1. The use of mini plates for intermaxillary fixation in a severely comminuted mandibular fracture with bilateral condylar fractures

    PubMed Central

    Clohessy, James William; Chang, Frank; Subramaniam, Shiva S.

    2016-01-01

    Intermaxillary fixation (IMF) is an integral technique utilized by maxillofacial surgeons to appropriately reduce and relate maxillary and mandibular fractures to both one another and the facial skeleton. This case report reviews the management of a comminuted mandibular fracture including inoperable bilateral condylar fractures that precluded the use of convention IMF techniques necessitating an alternative technique. This was achieved in the form of modified bony plates extending intraorally. Postoperative review showed favorable results with occlusion and range of motion comparable to the premorbid function and no unforeseen complications.

  2. Clinical results of using the proximal humeral internal locking system plate for internal fixation of displaced proximal humeral fractures.

    PubMed

    Norouzi, Masoud; Naderi, Mohammad Nasir; Komasi, Mehdi Hemmati; Sharifzadeh, Seyyed Reza; Shahrezaei, Mostafa; Eajazi, Alireza

    2012-05-01

    Proximal humerus fractures are accounting for 4-5% of all fractures with increasing incidence. Proximal Humeral Internal Locking System (PHILOS) plate is a new plate which permits early mobility and lowers the risk of complications. The aim of this study was to evaluate the functional outcome and the complication rate after using this plate. Between 2006-2008, 37 patients with displaced 2-, 3-, and 4-part fractures of the proximal humerus underwent surgery using PHILOS plate. The mean range of follow-up was 12 months. Twenty patients were aged 60 years and younger, and 17 were aged older than 60 years. The average American Shoulder and Elbow Surgeons (ASES) score at the final follow-up was 77.62. According to Michener and colleagues classification, 5.4% of patients had an excellent outcome, 72.9% were minimally functionally limited, 16.2% were moderately functionally limited, and 5.4% were maximally functionally limited. The average ASES score between patients 60 years and older and those 60 years and younger was not different significantly. One patient developed avascular necrosis of the humeral head, 2 patients developed an infection, and no patients developed a nonunion. Fixation with PHILOS plate can be considered a good method with high union rates for this kind of fracture, especially in the older population with osteoporotic bone.

  3. Mechanisms of failure of locked-plate fixation of the proximal humerus: acoustic emissions as a novel assessment modality.

    PubMed

    Hymes, Robert A; Levine, Matthew J; Schulman, Jeff E; Westbrook, Ryan D; Li, Jihui

    2013-07-01

    Locking plates are the predominant implants used for proximal humerus fractures. Despite a preponderance of good clinical outcomes, failures continue to occur. The purpose of this study was to investigate the failure mechanism of locked proximal humeral plate fixation and its relationship with bone density and screw length. Human cadaveric humeri were subjected to cyclic bending loads after an unstable 2-part fracture (Orthopedic Trauma Association classification 11 A-3) was created and stabilized with a locking proximal humeral plate. Acoustic emission (AE) sensors were mounted on the specimens to detect fracture displacement and generation of microcracks. The data were analyzed to evaluate construct failure. Eight of 10 locking plate constructs in cadaver specimens failed in varus collapse. The primary influences on failure were cancellous bone density and cancellous bone screw length. AE monitoring demonstrated patterns of microcrack progression, predominantly along the inferior screws. The progression trends according to AE were similar to their respective actuator displacement versus time curves. Cancellous bone density and total cancellous screw depth penetration seem to be critical variables. Although the patients' bone density cannot be controlled, surgeons may decrease the risk of failure by maximizing the length of the screws within the cancellous bone. Analysis of microcrack formation revealed that failures begin at the midportion and tips of the inferior screws and at the bone-plate interface of the inferior screws.

  4. Biomechanical optimization of bone plates used in rigid fixation of mandibular fractures.

    PubMed

    Lovald, Scott T; Wagner, Jon D; Baack, Bret

    2009-05-01

    To design and optimize a bone plate for fractures of the mandibular body that will provide maximum fracture stability with minimal implanted volume and patient intrusion. The design will be driven by the unique biomechanics specific to this fracture location. A finite element model of a fractured human mandible was created using tomography scans. Material properties were assigned to the cortical bone, cancellous bone, and dental region. Boundary conditions included simulating a unilateral molar clench and incisal loading. The bone plate design process included a shape optimization routine and design parameter analysis using the model. The optimized bone plate design was finally compared with standard bone plate configurations based on stress and strain measures. For incisal loading, the newly designed InterFlex II plate has 69% of the fracture strain and only 34% of the plate stress of an 8-hole strut plate. For unilateral molar loading, those numbers improve even further to 59% and 27%, respectively. InterFlex II plate stresses are less than or equal to the paired plate configuration, and fracture strain is within 10% of the corresponding paired plate strain under both loading scenarios. In terms of mechanical performance, InterFlex II is in the same class as the commonly used paired plate configuration, despite having only 55% of the implanted volume. A design process focused on shape and design variable optimization can produce bone plates that provide maximum fracture stability with minimum implanted volume.

  5. An in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: an axial positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion versus three parallel transarticular cortical screws inserted in lag fashion.

    PubMed

    Sod, Gary A; Riggs, Laura M; Mitchell, Colin F; Hubert, Jeremy D; Martin, George S

    2010-01-01

    To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP-TLS) with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (3-TLS) for the equine proximal interphalangeal (PIP) joint arthrodesis. Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Cadaveric adult equine forelimbs (n=15 pairs). For each forelimb pair, 1 PIP joint was stabilized with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion. Five matching pairs of constructs were tested in single cycle to failure under axial compression, 5 construct pairs were tested for cyclic fatigue under axial compression, and 5 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Mean yield load, yield stiffness, and failure load under axial compression and torsion, single cycle to failure, of the DCP-TLS fixation were significantly greater than those of the 3-TLS fixation. Mean cycles to failure in axial compression of the DCP-TLS fixation was significantly greater than that of the 3-TLS fixation. The DCP-TLS was superior to the 3-TLS in resisting the static overload forces and in resisting cyclic fatigue. The results of this in vitro study may provide information to aid in the selection of a treatment modality for arthrodesis of the equine PIP joint.

  6. Generalized wall function and its application to compressible turbulent boundary layer over a flat plate

    NASA Astrophysics Data System (ADS)

    Liu, J.; Wu, S. P.

    2017-04-01

    Wall function boundary conditions including the effects of compressibility and heat transfer are improved for compressible turbulent boundary flows. Generalized wall function formulation at zero-pressure gradient is proposed based on coupled velocity and temperature profiles in the entire near-wall region. The parameters in the generalized wall function are well revised. The proposed boundary conditions are integrated into Navier-Stokes computational fluid dynamics code that includes the shear stress transport turbulence model. Numerical results are presented for a compressible boundary layer over a flat plate at zero-pressure gradient. Compared with experimental data, the computational results show that the generalized wall function reduces the first grid spacing in the directed normal to the wall and proves the feasibility and effectivity of the generalized wall function method.

  7. Intramedullary Nailing Versus Plate Fixation for the Treatment Displaced Midshaft Clavicular Fractures: A Systematic Review and Meta-Analysis

    PubMed Central

    Hussain, Nasir; Sermer, Corey; Prusick, Parker J.; Banfield, Laura; Atrey, Amit; Bhandari, Mohit

    2016-01-01

    The two commonly performed surgical techniques used to repair displaced midshaft clavicle fractures are plate fixation or intramedullary nailing; however, despite recent evidence, the optimal method to treat such fractures remains a continued topic of debate. A meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate long term function, complications, and operative duration in adult patients receiving intramedullary nailing in comparison to plating. Seven RCTs and three quasi-randomized trials were included. No significant difference was found in long-term function between the two groups (MD: −0.66, 95% CI: −2.03 to 0.71, I2 = 62%, p = 0.34). Patients who received plating had a 2.19 times increased risk of treatment failure, but this failed to reach significance (95% CI: 0.93 to 5.15, I2 = 0%, p = 0.07). The risk of non-operative complications was 2.11 times higher in patients who received plating and this reached statistical significance (95% CI: 1.38 to 3.23, I2 = 53%, p = 0.0006). Finally, plating significantly prolonged operative duration by 20.16 minutes (95% CI: 16.87 to 23.44, I2 = 56%, p < 0.00001). Our results suggest that intramedullary nailing and plating provide equivalent long-term functional outcomes; however, plating may lead to a higher risk of treatment failure and non-operative complications. PMID:27762393

  8. Postbuckling response of long thick isotropic plates loaded in compression including higher order transverse shearing effects

    NASA Technical Reports Server (NTRS)

    Stein, Manuel; Sydow, P. Daniel; Librescu, Liviu

    1990-01-01

    Buckling and postbuckling results for aluminum plates loaded in compression are presented. The buckling results were plotted to show the effects of thickness on the stress coefficient. Buckling results are given for various length-to-width ratios. Postbuckling results for plates with transverse shearing flexibility are compared to results from classical theory for various width-to-thickness ratios. The plates are considered to be long with side edges simply supported, with edges free of stress and the plates are subjected to longitudinal compressive displacement. Characteristic curves indicating the average longitudinal direct stress resultant as a function of the applied displacements are calculated based on four different theories: Classical von Karman, first-order shear deformation, higher-order shear deformation, and three-dimensional flexibility. Present results indicate that the three-dimensional flexibility theory gives the lowest and therefore, most accurate results. The higher-order shear deformation theory has fewer unknowns than the three-dimensional flexibility but is not as accurate. The figures presented show that small differences occur in the maximum stress resultants and the transverse displacements calculated when the effects of transverse shear are included.

  9. Measurements of displacement around holes in composite plates subjected to quasi-static compression

    NASA Technical Reports Server (NTRS)

    Duke, J. C., Jr.; Post, D.; Czarnek, R.; Asundi, A.

    1982-01-01

    Attempts to develop a whole-field, high sensitivity optical technque for measurement of load induced changes of thickness of composite plates are described. Graphite-epoxy plates of quasi-isotropic layup were used as test specimens. Changes of thickness of three plates, each with a central hole of different size, were measured as a function of applied compressive loads. The first test specimen showed localized zones where no holographic fringes were present, surrounded by zones of low fringe contrast. This was thought to be a result of localized motion or creep. Subsequent tests with an increased time interval between specimen loading and holographic exposure demonstrated no localized zones of absent fringes. No plausible explanation for radical differences in the quality of fringe patterns was found, although the use of specimens having a high quality mirrorized surface provided superior change of thickness patterns. Recommendations for further investigations and changes in test procedure are presented.

  10. Biomechanical evaluation of two plating configurations for fixation of a simple transverse caudal mandibular fracture model in cats.

    PubMed

    Greiner, Christopher L; Verstraete, Frank J M; Stover, Susan M; Garcia, Tanya C; Leale, Dustin; Arzi, Boaz

    2017-06-01

    OBJECTIVE To evaluate biomechanical properties of intact feline mandibles, compared with those for mandibles with an experimentally created osteotomy that was stabilized with 1 of 2 internal fixation configurations. SAMPLE 20 mandibles from 10 adult feline cadavers. PROCEDURES An incomplete block study design was used to assign the mandibles of each cadaver to 2 of 3 groups (locking plate with locking screws [locking construct], locking plate with nonlocking screws [nonlocking construct], or intact). Within each cadaver, mandibles were randomly assigned to the assigned treatments. For mandibles assigned to the locking and nonlocking constructs, a simple transverse osteotomy was created caudal to the mandibular first molar tooth after plate application. All mandibles were loaded in cantilever bending in a single-load-to-failure test while simultaneously recording load and actuator displacement. Mode of failure (bone or plate failure) was recorded, and radiographic evidence of tooth root and mandibular canal damage was evaluated. Mechanical properties were compared among the 3 groups. RESULTS Stiffness, bending moments, and most post-yield energies for mandibles with the locking and nonlocking constructs were significantly lower than those for intact mandibles. Peak bending moment and stiffness for mandibles with the locking construct were significantly greater than those for mandibles with the nonlocking construct. Mode of failure and frequency of screw damage to tooth roots and the mandibular canal did not differ between the locking and nonlocking constructs. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that both fixation constructs were mechanically inferior to intact mandibles. The locking construct was mechanically stronger than the nonlocking construct.

  11. Biomechanical Comparison of Inter-fragmentary Compression Pressures: Lag Screw versus Herbert Screw for Anterior Odontoid Screw Fixation.

    PubMed

    Park, Jin-Woo; Kim, Kyoung-Tae; Sung, Joo-Kyung; Park, Seong-Hyun; Seong, Ki-Woong; Cho, Dae-Chul

    2017-09-01

    The purpose of the present study was to compare inter-fragmentary compression pressures after fixation of a simulated type II odontoid fracture with the headless compression Herbert screw and a half threaded cannulated lag screw. We compared inter-fragmentary compression pressures between 40- and 45-mm long 4.5-mm Herbert screws (n=8 and n=9, respectively) and 40- and 45-mm long 4.0-mm cannulated lag screws (n=7 and n=10, respectively) after insertion into rigid polyurethane foam test blocks (Sawbones, Vashon, WA, USA). A washer load cell was placed between the two segments of test blocks to measure the compression force. Because the total length of each foam block was 42 mm, the 40-mm screws were embedded in the cancellous foam, while the 45-mm screws penetrated the denser cortical foam at the bottom. This enabled us to compare inter-fragmentary compression pressures as they are affected by the penetration of the apical dens tip by the screws. The mean compression pressures of the 40- and 45-mm long cannulated lag screws were 50.48±1.20 N and 53.88±1.02 N, respectively, which was not statistically significant (p=0.0551). The mean compression pressures of the 40-mm long Herbert screw was 52.82±2.17 N, and was not statistically significant compared with the 40-mm long cannulated lag screw (p=0.3679). However, 45-mm Herbert screw had significantly higher mean compression pressure (60.68±2.03 N) than both the 45-mm cannulated lag screw and the 40-mm Herbert screw (p=0.0049 and p=0.0246, respectively). Our results showed that inter-fragmentary compression pressures of the Herbert screw were significantly increased when the screw tip penetrated the opposite dens cortical foam. This can support the generally recommended surgical technique that, in order to facilitate maximal reduction of the fracture gap using anterior odontoid screws, it is essential to penetrate the apical dens tip with the screw.

  12. [Wrist arthrodesis with a fixed-angle, "low-profile" fusion plate without carpometacarpal joint fixation].

    PubMed

    Köhler, S; Koch, K; Arsalan-Werner, A; Mehling, I M; Seegmüller, J; Krimmer, H; Sauerbier, Michael

    2017-09-12

    Total wrist arthrodesis to improve functional use of the hand by reducing pain and increasing grip strength. Painful destruction of the radio- and midcarpal joints. Analgesia and satisfactory hand function after motion-preserving surgical or conservative treatment. Chronic joint infection. Posterior approach to the wrist. Removal of articular surfaces destroyed all the way down to cancellous bone. Filling of defects with cancellous bone graft taken from distal radius or iliac crest. Osteosynthesis with fixed-angle wrist fusion plate without carpometacarpal (CMC) III joint fixation. Below-elbow cast for 2 weeks. Immediate active motion fingers exercises. X‑ray control 6 weeks postoperatively. Gradual increase of normal hand use in daily life after bony consolidation. Total wrist arthrodesis was performed using a fixed-angle fusion plate without CMC III joint fixation in 28 patients (21 men, 7 women). A follow-up of 14/28 patients was performed at a mean of 21 (3-39) months postoperatively. Grip strength improved from 14 (0-38) kg preoperatively to 22 (12-40) kg postoperatively. The average postoperative DASH score was 40 (6-72) points. Pain measured with the VAS scale (0-10) improved from an average of 7 (3-10) points preoperatively to 2 (0-6) points postoperatively. Overall, 13/14 patients were satisfied with the treatment; 26/28 patients achieved primary bony consolidation. Postoperative complications found in 9 of 28 patients: 2 nonunion, pain in the CMC II (n = 3) or III (n = 1) joints, 2 screw breakage, 1 postoperative bleeding and 1 infection. Both cases of nonunion healed after plate removal, re-osteosynthesis with a straight wrist arthrodesis plate, bridging the CMC III joint, and a bone graft from the iliac crest. All patients with CMC II joint pain were pain-free after removal of the protruding screw. One patient had chronic pain in the CMC III joint despite plate removal. In the 2 cases with screw breakage, no issues caused. In

  13. In vitro mechanical evaluation of a limited contact dynamic compression plate and hybrid carpal arthrodesis plate for canine pancarpal arthrodesis.

    PubMed

    Guillou, R P; Demianiuk, R M; Sinnott, M T; Curcio, K; DeCamp, C E; Haut, R C; Déjardin, L M

    2012-01-01

    To compare the mechanical properties of pancarpal arthrodesis (PCA) constructs stabilized at 20° of extension using either a 3.5 mm limited contact dynamic compression plate (LC-DCP) or a 3.5/2.7 mm hybrid plate (HP). Seven forelimb pairs were used from dogs of similar size. All soft tissues were removed except for supporting structures of the carpus and proximal metacarpal region. All plates were accurately bent to 20°, and then instrumented with two, 350Ω strain gauges applied at the level of the bend. Constructs were embedded in epoxy moulds then mounted onto a servo-hydraulic testing machine. Specimens were loaded for 10 cycles at 100N, 200N and 300N. Tenth cycle construct compliance (CC), maximum angular deformation (MAD), and peak plate strain (PPS) were compared using two-factor analysis of variance (ANOVA) and Student-Newman-Keuls post-hoc tests (p <0.05). Regardless of load, CC was 29% to 33% smaller in the HP than the LC-DCP group (p <0.03). In each group, the CC significantly increased with increasing loads (p <0.02). Mean MAD was 19% to 22% less in HP than LC-DCP constructs, with significant differences seen at 200N and 300N loads. In both groups, MAD was significantly greater with increasing loads (p <0.02). In addition, PPS was 37% to 43% smaller for HP than LC-DCP. The mechanical advantages of the HP over the LC-DCP make it a viable alternative for PCA. Smaller CC, MAD and PSS of the HP may reduce the risk of implant failure and postoperative morbidity following PCA.

  14. Fixator-assisted Technique Enables Less Invasive Plate Osteosynthesis in Medial Opening-wedge High Tibial Osteotomy: A Novel Technique.

    PubMed

    Lee, Dong Hoon; Ryu, Keun Jung; Kim, Jae Hwa; Kim, Hae Hwa; Soung, Sahyun; Shin, Soowan

    2015-10-01

    Opening-wedge high tibial osteotomy is a well-established procedure in the management of medial osteoarthritis of the knee and correction of proximal tibia vara. Recently, surgical approaches using less invasive plate osteosynthesis have been used with the goal of minimizing complications from more extensive soft tissue exposures. However, to our knowledge, less invasive fixator-assisted plate osteosynthesis has not been tested in the setting of opening-wedge high tibial osteotomy. The purposes of this study were (1) to assess the complications associated with use of a fixator-assisted less invasive plate osteosynthesis technique to stabilize an opening-wedge high tibial osteotomy in the treatment of proximal tibial vara; and (2) to evaluate the ability of this technique to achieve correction of the proximal tibial deformity and achieve osseous union. From June 2011 to June 2013, a total of 157 limbs in 83 patients who underwent fixator-assisted high tibial osteotomy for (1) idiopathic genu vara; or (2) osteoarthritis of the knee with proximal tibia vara were initially enrolled. Of these, eight limbs (5%) were excluded on the way; thus, 149 limbs in 77 patients were evaluated. During the period in question, no other techniques were used for proximal tibial osteotomy. The surgical procedures included less preparation of soft tissue, proximal tibial osteotomy, application of a temporary external fixator, correction of alignment, and final fixation with the help of an external fixator. Complications were assessed by chart review and the alignment in both coronal and sagittal planes was compared pre- and postoperatively. Radiographic review to confirm osseous union and alignment was performed by two of the authors not involved in clinical care of the patient. Delayed union was described as union occurring later than 4 months. Thirty limbs out of 149 tibiae (20%) showed complications, all of which were resolved without leaving any sequela. Twenty-seven limbs out of 149

  15. Risk factors for postoperative wound complications of calcaneal fractures following plate fixation.

    PubMed

    Ding, Liang; He, Zhimin; Xiao, Haijun; Chai, Leizi; Xue, Feng

    2013-09-01

    A fairly high prevalence of wound complications after open reduction and internal plate fixation (ORIF) of closed calcaneal fractures via the extensile lateral approach has been reported. The goal of this study was to analyze and identify independent risk factors for wound complications among closed calcaneal fractures undergoing ORIF. The medical records of all closed calcaneal fracture patients who underwent ORIF from July 2005 to July 2012 were reviewed to identify those who developed a wound complication. Then we constructed a univariate and multivariate logistic regression to evaluate the independent associations of potential risk factors for surgical wound complication. Records showed 479 patients who underwent ORIF of a closed calcaneal fracture from July 2005 to July 2012. The patients were followed for 3 to 28 months, with an average follow-up period of 14.2 months. Eleven patients had bilateral fractures, for a total of 490 fractured calcanei. The overall rate of postoperative wound complications following ORIF of closed calcaneus fractures was 17.8% (87 wound complications in 490 operations). With the regression model, smoking history (odds ratio, 5.79; 95% CI: 1.55 to 21.70; P = .009), diabetes mellitus (odds ratio, 6.23; 95% CI: 1.37 to 28.31; P = .018), Sanders type (odds ratio, 5.44; 95% CI: 2.02 to 14.64; P = .001), number of residents and/or fellows present during the case (odds ratio, 1.63; 95% CI: 1.06 to 2.52; P = .028), duration of surgery (odds ratio, 4.54; 95% CI: 1.46 to 14.12; P < .001), estimated blood loss (odds ratio, 1.02; 95% CI: 1.01 to 1.04%; P < .001), and 10 or more people present in the operating room during the entire case (odds ratio, 2.30; 95% CI: 1.79 to 2.94; P < .001) were risk factors for wound complication. Tourniquet use (odds ratio, 0.02; 95% CI: 0.00 to 0.08; P < .001), which was associated with a decreased risk for the development of a wound complication, was observed as a protective factor. Diabetes mellitus, Sanders

  16. Treatment of Non Unions of Subtrochanteric Fractures Using an Anatomical Proximal Femur Locked Compression Plate – A Prospective Study of 13 Patients

    PubMed Central

    Balasubramanian, Navin; Babu, Ganesh; Prakasam, Sindhuja

    2016-01-01

    Introduction: Subtrochanteric fractures have a bimodal age distribution. They are mostly due to high violence trauma in the younger age group. They almost always require open reduction and internal fixation. Due to the increase in the emergence of native bone setters, these fractures are increasingly been managed by these spurious bone setters using native splints. As a result, non-union rate is high among such patients. These patients definitely need open reduction with internal fixation +/- bone grafting. The choice of implants used can be either a dynamic condylar screw plate (DCS) orproximal femoral nail (PFN). Case series: Here we have used a surgical grade 316 L stainless steel proximal femoral anatomical locked compression plate (PF-LCP). We analyzed 13 patients with established non unions of subtrochanteric fractures treated in our centre by the use of the PF-LCP. There were 10 males and 3 females. The average age was 48.23 years. All our patients were followed up by serial radiographs at 6, 12, 18, 24 weeks and thereafter at 6 months interval. Union was achieved in 11 out of 13 patients at 12 weeks whereas two patients had delayed union which eventually healed at 18 weeks and 24 weeks. The average Harris hip score at 1 year follow-up was excellent in eight, good in four and fair in one patient respectively. Conclusion: We conclude that in complicated non-unions, the use of PF-LCP has a definite positive role in the management of such cases. PMID:27299132

  17. Is intramedullary fixation of displaced midshaft clavicle fracture superior to plate fixation? Evidence from a systematic review of discordant meta-analyses.

    PubMed

    Xu, Bin; Lin, Yongsheng; Wang, Zhihong; Cao, Junming; Yang, Yipeng; Xia, Hehuan; Zhang, Yingze

    2017-07-01

    An increasing number of meta-analyses comparing intramedullary fixation (IF) with plate fixation (PF) for displaced midshaft clavicle fracture have been reported, but the inconsistent results obtained might confuse decision-making. We systematically reviewed discordant meta-analyses for assisting the decision-maker in interpreting and selecting amongst discordant meta-analyses and providing surgical recommendations for displaced midshaft clavicle fracture according to currently best available evidence. Meta-analyses on IF and PF for displaced midshaft clavicle fracture were identified by searching PubMed, Emabase and the Cochrane Library. A review of meta-analysis quality and data extraction was individually conducted by two reviewers. The meta-analysis providing the best available evidence was identified using the Jadad decision algorithm. Nine studies were included, five of which were of Level-II evidence and four of which were of Level-III evidence. These meta-analyses scored from 6 to 10 according to the Assessment of Multiple Systematic Reviews instrument. With respect to the Jadad decision algorithm, the best meta-analysis was chosen depending upon publication characteristics and methodology of primary studies, language restrictions, and whether data on individual patients were analysed. A meta-analysis incorporating more randomised controlled trials was eventually selected. The best available evidence indicated that the differences between IF and PF were not significant in terms of shoulder function or the rate of treatment failure. However, IF significantly decreased the operative time and the rate of non-operative complications, especially the rate of infection. Based on the best available evidence, IF may be superior to PF for treating displaced midshaft clavicle fracture. Copyright © 2017. Published by Elsevier Ltd.

  18. A Novel Shape Memory Plate Osteosynthesis for Noninvasive Modulation of Fixation Stiffness in a Rabbit Tibia Osteotomy Model

    PubMed Central

    Müller, Christian W.; Pfeifer, Ronny; Meier, Karen; Decker, Sebastian; Reifenrath, Janin; Gösling, Thomas; Wesling, Volker; Krettek, Christian; Krämer, Manuel

    2015-01-01

    Nickel-titanium shape memory alloy (NiTi-SMA) implants might allow modulating fracture healing, changing their stiffness through alteration of both elastic modulus and cross-sectional shape by employing the shape memory effect (SME). Hypotheses: a novel NiTi-SMA plate stabilizes tibia osteotomies in rabbits. After noninvasive electromagnetic induction heating the alloy exhibits the SME and the plate changes towards higher stiffness (inverse dynamization) resulting in increased fixation stiffness and equal or better bony healing. In 14 rabbits, 1.0 mm tibia osteotomies were fixed with our experimental plate. Animals were randomised for control or induction heating at three weeks postoperatively. Repetitive X-ray imaging and in vivo measurements of bending stiffness were performed. After sacrifice at 8 weeks, macroscopic evaluation, µCT, and post mortem bending tests of the tibiae were carried out. One death and one early implant dislocation occurred. Following electromagnetic induction heating, radiographic and macroscopic changes of the implant proved successful SME activation. All osteotomies healed. In the treatment group, bending stiffness increased over time. Differences between groups were not significant. In conclusion, we demonstrated successful healing of rabbit tibia osteotomies using our novel NiTi-SMA plate. We demonstrated shape-changing SME in-vivo through transcutaneous electromagnetic induction heating. Thus, future orthopaedic implants could be modified without additional surgery. PMID:26167493

  19. A biomechanical comparison of external skeletal fixation and plating for the stabilization of ilial osteotomies in dogs.

    PubMed

    Fitzpatrick, N; Lewis, D; Cross, A

    2008-01-01

    This in vitro study compares the biomechanical properties of two methods of ilial fracture repair in dogs. Ten pelves were harvested from skeletally mature mixed breed dogs weighing 20-27 kg and bilateral oblique ilial body osteotomies were created. One hemipelvis from each dog was stabilized with a 2.7 mm plate and screws and the contralateral hemipelvis was stabilized with a five pin linear external fixator construct. Each hemipelvis was mounted at an angle of 30 degrees to an actuator platform, such that the acetabulum was centrally loaded by a steel sphere attached to the load cell of a servohydraulic materials testing machine. The construct was loaded at a constant rate of 20 mm/min. A load/displacement curve was generated for each hemipelvis by plotting the sustained load against the actuator movement. The stiffness, yield load and failure load for each hemipelvis were determined from the load/displacement curve. Bending stiffness was defined as the slope of the load/displacement curve from 100 N to yield load. The mode of failure was determined by observations made during testing and gross inspection of each specimen. The mean construct stiffness, yield load and failure load were compared between stabilization groups using a Student's paired t-test with statistical significance set at p<0.05. Nine out of 10 of the hemipelves that were stabilized by plates and screws failed catastrophically by fracture through the caudal screw holes and nine out of 10 of the hemipelves that were stabilized using an external fixator failed by fracture of the ischium in the region supported by the mounting roller, propagating through the most caudal ischial pin. There was not any significant difference (P=0.22) in bending stiffness between stabilization techniques, but yield (1467 N vs 2620 N; P=0.04) and failure (1918 N vs 2687 N; P=0.002) loads were significantly greater for hemipelves stabilized with external fixators.

  20. Comparison of single coracoclavicular suture fixation and hook plate for the treatment of acute unstable distal clavicle fractures.

    PubMed

    Chen, Chun-Yu; Yang, Shan-Wei; Lin, Kuan-Yu; Lin, Kai-Cheng; Tarng, Yih-Wen; Renn, Jenn-Huei; Lai, Chia-Hsin

    2014-05-29

    Surgical managements are recommended for unstable distal clavicle fractures because of a high incidence of nonunion. A variety of methods have been previously reported, but there is no current consensus regarding which method is the most suitable. Between December 2004 and August 2010, we treated 68 patients with Neer type IIB distal clavicle fractures using single coracoclavicular suture fixation with Mersilene tape (M group) or clavicular hook plate (H group). Sixty-eight patients were followed at least 24 months (mean, 37.9 months). We retrospectively compared the functional outcome, parameters, and perioperative course of the two treatments. Statistical analysis was performed with independent sample t test and chi-square test. The M group presented significantly less operation time (P = 0.005) and intra-operative blood loss (P = 0.010) than the H group. The mean University of California at Los Angeles (UCLA) shoulder rating scale, Oxford shoulder score, VAS scale, and satisfaction score revealed no significant difference between the M group and the H group. The M group had better range of motion in the operated shoulder during forward flexion and abduction at 3 and 6 months postoperatively. However, the range of motion at 1 and 2 years after operation revealed almost the same results. Two acromial osteolysis and one acromial fracture were noted in the H group and one superficial wound infection and one frozen shoulder in the M group during follow-up. Finally, there was no significant difference in the complication rate between the two groups, and all fractures achieved union clinically at final follow-up. Both single coracoclavicular suture fixation and clavicular hook plate offered effective treatment in acute unstable distal clavicle fractures. However, single coracoclavicular suture fixation with Mersilene tape provided early recovery of shoulder motion and avoided further morbidity of the acromion.

  1. Comparison of single coracoclavicular suture fixation and hook plate for the treatment of acute unstable distal clavicle fractures

    PubMed Central

    2014-01-01

    Background Surgical managements are recommended for unstable distal clavicle fractures because of a high incidence of nonunion. A variety of methods have been previously reported, but there is no current consensus regarding which method is the most suitable. Methods Between December 2004 and August 2010, we treated 68 patients with Neer type IIB distal clavicle fractures using single coracoclavicular suture fixation with Mersilene tape (M group) or clavicular hook plate (H group). Sixty-eight patients were followed at least 24 months (mean, 37.9 months). We retrospectively compared the functional outcome, parameters, and perioperative course of the two treatments. Statistical analysis was performed with independent sample t test and chi-square test. Results The M group presented significantly less operation time (P = 0.005) and intra-operative blood loss (P = 0.010) than the H group. The mean University of California at Los Angeles (UCLA) shoulder rating scale, Oxford shoulder score, VAS scale, and satisfaction score revealed no significant difference between the M group and the H group. The M group had better range of motion in the operated shoulder during forward flexion and abduction at 3 and 6 months postoperatively. However, the range of motion at 1 and 2 years after operation revealed almost the same results. Two acromial osteolysis and one acromial fracture were noted in the H group and one superficial wound infection and one frozen shoulder in the M group during follow-up. Finally, there was no significant difference in the complication rate between the two groups, and all fractures achieved union clinically at final follow-up. Conclusions Both single coracoclavicular suture fixation and clavicular hook plate offered effective treatment in acute unstable distal clavicle fractures. However, single coracoclavicular suture fixation with Mersilene tape provided early recovery of shoulder motion and avoided further morbidity of the acromion. PMID

  2. Complications following dorsal versus volar plate fixation of distal radius fracture: a meta-analysis.

    PubMed

    Wei, Jie; Yang, Tu-Bao; Luo, Wei; Qin, Jia-Bi; Kong, Fan-Jing

    2013-04-01

    A meta-analysis to compare complication rates following volar or dorsal surgical fixation of distal radius fracture. A detailed search of PubMed®/MEDLINE® was undertaken to identify randomized and nonrandomized controlled trials published before 25 August 2012 that compared volar with dorsal fixation, in patients with distal radius fracture. A quantitative meta-analysis of 12 trials (952 patients) was performed. There was no between-group difference in the overall rate of complications. Volar fixation was associated with significant increases in neuropathy (relative risk [RR] 2.19; 95% confidence intervals [CI] 1.27, 3.76) and carpal tunnel syndrome (RR 4.56; 95% CI 1.02, 20.44), and a reduction in tendon irritation, compared with the dorsal approach (RR 0.38; 95% CI 0.17, 0.86). Dorsal fixation offers a lower risk of neuropathy and carpal tunnel syndrome than the volar approach, but a higher risk of tendon irritation. Patients with a distal radius fracture can expect similar outcomes after volar or dorsal surgery.

  3. In vivo analysis of acromioclavicular joint motion after hook plate fixation using three-dimensional computed tomography.

    PubMed

    Kim, Yoon Sang; Yoo, Yon-Sik; Jang, Seong Wook; Nair, Ayyappan Vijayachandran; Jin, Hyonki; Song, Hyun-Seok

    2015-07-01

    The clavicle hook plate can be used to treat acromioclavicular and coracoclavicular ligament injury or distal clavicular fracture with comminution. However, the hook plate can induce subacromial impingement, resulting in discomfort from the hardware. Our inclusion criteria were (1) men and women aged older than 20 years and (2) the presence of comminuted distal clavicular fractures (Neer type IIB) fixed with a hook plate (Synthes, Oberdorf, Switzerland). Three-dimensional computed tomography was obtained before removal of the hook plate. Seven patients were enrolled prospectively. The mean age was 42 years (range, 24-60 years). Zero degree images and abduction images were obtained. The sagittal cut surface was obtained 5 mm medial from the distal clavicle. The equator of the cut surface of the clavicle was compared with the full abduction model to analyze rotation. The center of the cut surface of the clavicle was compared with the full abduction model to analyze translation. The average difference in rotation of the distal clavicle between both shoulders was 16° (range, 3°-22°; P = .001). The mean difference in anterior translation of the distal clavicle was 2.2 mm (range, -0.7 to 5.6 mm; P = .030). Hook plate fixation at the acromioclavicular joint causes decreased internal rotation and increased anterior translation of the distal clavicle with respect to the medial acromion, indicating that the scapula relative to the thorax has decreased posterior tilting and increased external rotation in shoulders fixed using a hook plate. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  4. A Biomechanical Comparison of Three 1.5-mm Plate and Screw Configurations and a Single 2.0-mm Plate for Internal Fixation of a Mandibular Condylar Fracture

    PubMed Central

    Aquilina, Peter; Parr, William C.H.; Chamoli, Uphar; Wroe, Stephen; Clausen, Philip

    2014-01-01

    The most stable pattern of internal fixation for mandibular condyle fractures is an area of ongoing discussion. This study investigates the stability of three patterns of plate fixation using readily available, commercially pure titanium implants. Finite element models of a simulated mandibular condyle fracture were constructed. The completed models were heterogeneous in bone material properties, contained approximately 1.2 million elements and incorporated simulated jaw adducting musculature. Models were run assuming linear elasticity and isotropic material properties for bone. No human subjects were involved in this investigation. The stability of the simulated condylar fracture reduced with the different implant configurations, and the von Mises stresses of a 1.5-mm X-shaped plate, a 1.5-mm rectangular plate, and a 1.5-mm square plate (all Synthes (Synthes GmbH, Zuchwil, Switzerland) were compared. The 1.5-mm X plate was the most stable of the three 1.5-mm profile plate configurations examined and had comparable mechanical performance to a single 2.0-mm straight four-hole plate. This study does not support the use of rectangular or square plate patterns in the open reduction and internal fixation of mandibular condyle fractures. It does provide some support for the use of a 1.5-mm X plate to reduce condylar fractures in selected clinical cases. PMID:25136411

  5. Lateral transpsoas interbody fusion (LTIF) with plate fixation and unilateral pedicle screws: a preliminary report.

    PubMed

    Kepler, Christopher K; Sharma, Amit K; Huang, Russel C

    2011-08-01

    Retrospective cohort study. We present the radiographic and clinical outcomes of 13 patients who underwent lateral transpsoas interbody fusion (LTIF) stabilized by unilateral pedicle screw instrumentation and anterior instrumentation. LTIF is a surgical technique that permits anterior column lumbar interbody fusion via a direct lateral transpsoas approach. Because of the inherent stability of the implants used and the minimal disruption of stabilizing ligaments associated with LTIF, this technique may allow use of less invasive adjunctive fixation methods including unilateral pedicle screw fixation. Information from medical records included patient demographics, medical comorbidities, clinical assessment, surgical time, blood loss, implant information, and complications. Oswestry Disability Index, Short Form-12, and visual analog pain scale scores were obtained. Postoperative imaging allowed assessment of fusion, subsidence, and alignment. Estimated blood loss averaged 225 mL and operative time averaged 261 minutes. No patients received a transfusion. Average length of hospital stay was 4.6 days. Oswestry Disability Index, Short Form-12, and visual analog pain scores demonstrated significant improvement. All patients with available 1 year postoperative imaging demonstrated solid fusion with average cranial and caudal subsidence of 1.8 and 0.8 mm, respectively. Two patients developed postoperative nondisplaced vertebral fractures through the anterior fixation screw tracts. Three patients developed transient postoperative hip flexion weakness and one also developed transient hypoesthesia in the anterior thigh, likely approach related. We report a series of patients treated with unilateral pedicle screw fixation with LTIF. Although the patient cohort is small, validated outcomes instruments were used and fusion was assessed by computed tomography scan in most cases. The data suggest that unilateral pedicle screw fixation may be adequate to achieve high fusion rates

  6. Postbuckling response of long thick plates loaded in compression including higher order transverse shearing effects

    NASA Technical Reports Server (NTRS)

    Stein, Manuel; Sydow, P. Daniel; Librescu, Liviu

    1990-01-01

    Buckling and postbuckling results are presented for compression-loaded simply-supported aluminum plates and composite plates with a symmetric lay-up of thin + or - 45 deg plies composed of many layers. Buckling results for aluminum plates of finite length are given for various length-to-width ratios. Asymptotes to the curves based on buckling results give N(sub xcr) for plates of infinite length. Postbuckling results for plates with transverse shearing flexibility are compared to results from classical theory for various width-to-thickness ratios. Characteristic curves indicating the average longitudinal direct stress resultant as a function of the applied displacements are calculated based on four different theories: Classical von Karman theory using the Kirchoff assumptions, first-order shear deformation theory, higher-order shear deformation theory, and 3-D flexibility theory. Present results indicate that the 3-D flexibility theory gives the lowest buckling loads. The higher-order shear deformation theory has fewer unknowns than the 3-D flexibility theory but does not take into account through-the-thickness effects. The figures presented show that small differences occur in the average longitudinal direct stress resultants from the four theories that are functions of applied end-shortening displacement.

  7. PEEK versus titanium locking plates for proximal humerus fracture fixation: a comparative biomechanical study in two- and three-part fractures.

    PubMed

    Schliemann, Benedikt; Seifert, Robert; Theisen, Christina; Gehweiler, Dominic; Wähnert, Dirk; Schulze, Martin; Raschke, Michael J; Weimann, Andre

    2017-01-01

    The high rigidity of metal implants may be a cause of failure after fixation of proximal humerus fractures. Carbon fiber-reinforced polyetheretherketone (PEEK) plates with a modulus similar to human cortical bone may help to overcome this problem. The present study assesses the biomechanical behavior of a PEEK plate compared with a titanium locking plate. Unstable two- and three-part fractures were simulated in 12 pairs of cadaveric humeri and were fixed with either a PEEK or a titanium locking plate using a pairwise comparison. With an optical motion capture system, the stiffness, failure load, plate bending, and the relative motion at the bone-implant interface and at the fracture site were evaluated. The mean load to failure for two- and three-part fracture fixations was, respectively, 191 N (range 102-356 N) and 142 N (range 102-169 N) in the PEEK plate group compared with 286 N (range 191-395 N) and 258 N (range 155-366 N) in the titanium locking plate group. The PEEK plate showed significantly more bending in both the two- and three-part fractures (p < 0.05), an increased relative motion at the bone-implant interface and lower stiffness values (p < 0.05). In this biomechanical study on unstable proximal humerus fractures, fixation with a PEEK plate showed lower fixation strength and increased motion at the bone-implant interface compared with a titanium locking plate.

  8. [Comparing clinical effects of titanic elastic nail and locking compression pine fixation in treating subtrochanteric fractures in older children].

    PubMed

    Zhu, Kang-xiang; Yin, Shan-qing

    2013-12-01

    To explore optimal choice of surgical treatment for subtrochanteric fractures in older children. A retrospective study of 36 older children with subtrochanteric fractures was performed between January 2010 and January 2012. Among them, 18 patients (11 males and 7 females) aged from 7 to 13 years old with an average of 9.4 were treated with titanic elastic nail (TEN) fixation, 4 cases were Type II A, 3 cases were II B, 2 cases were II C, 4 cases were III A, 3 cases were III B according to Seinsheimer classification. Eighteen patients (10 males and 8 females) aged was from 8 to 13 years with an average of 9.6 were treated with locking compression pine (LCP) fixation, and 3 cases were Type II A, 4 cases were II B, 3 cases were II C, 4 cases were IIIA, 2 cases were III B. Fracture healing time, postoperative complications (including wound infection, failure and breakage of internal fixtion, deformities of angular on the sagittal view, deformities of coxa vara) and recovery of hip joint function were observed and recorded. All children were followed up from 15 to 36 months with an average of 21. Fracture were all healed, the time ranged from 7 to 16 weeks (mean 9.5). Three cases in TEN group occurred mild deformities of angular on the sagittal view, 3 cases occurred deformities of coxa vara and 2 cases occurred limb shortening; while 1 case occurred mild deformities of angular on the sagittal view, and no deformities of coxa vara and limb shortening occurred in LCP group. No early close of epiphyseal injury, avascular necrosis of femoral head occurred. Clinical efficacy were evaluated by Sanders standard, 14 cases got excellent results, 3 cases were moderate in LCP group, while 9 cases in excellent, 4 in moderate in TEN group. There were no significant differences between two group in recovery of hip joint function and complications. For the treatment of subtrochanteric fractures in older children,the efficacy of LCP fixation is better than that of TFN fixation, which

  9. [BIOMECHANICAL RESEARCH OF DIFFERENT INTERNAL FIXATIONS USING LOCKING RECONSTRUCTION PLATE FOR ACETABULAR TRANSVERSE FRACTURE].

    PubMed

    Liu, Hongyang; Li, Ligeng; Wu, Xiaobo; Xu, Hongjia; Zhang, Ruijie

    2015-09-01

    To compare the biomechanical stability of acetabular transverse fracture fixed with single column locking reconstruction plate, locking reconstruction plate combined with lag screw, and double columns lag screws. Acetabular transverse fractures were established in 20 adult fresh semi-pelvis specimens, and divided into 5 groups randomly (n=4). The anterior columns were fixed with locking reconstruction plates in group A; the posterior columns were fixed with locking reconstruction plates in group B; the anterior columns were fixed with locking reconstruction plates and the posterior columns with lag screws in group C; the anterior columns were fixed with lag screws and the posterior columns with locking reconstruction plates in group D; the double columns were fixed with lag screws in group E. When loading three times weight, the longitudinal displacement of fracture fragment was measured, and the shear rigidity was calculated to compare the stability among groups. The longitudinal displacement of groups A and B were significantly greater than that of groups C, D, and E (P<0.05), and the shear rigidity of groups A and B were significantly lower than that of groups C, D, and E (P< 0.05). The longitudinal displacement of group B was significantly greater than that of group A (P< 0.05), but no significant difference was found in the shear rigidity between groups A and B (P>0.05). There was no significant difference in the longitudinal displacement and shear rigiditramong groups C, D, and E (P>0.05). Locking reconstruction plate combined with lag screw and double columns lag screws have similar stability, they have stronger stability than the single column locking reconstruction plate. The stability of anterior column locking reconstruction plate is better than that of the posterior column locking reconstruction plate.

  10. UK Fixation of Distal Tibia Fractures (UK FixDT): protocol for a randomised controlled trial of ‘locking’ plate fixation versus intramedullary nail fixation in the treatment of adult patients with a displaced fracture of the distal tibia

    PubMed Central

    Achten, Juul; Parsons, Nicholas R; McGuinness, Katie R; Petrou, Stavros; Lamb, Sarah E; Costa, Matthew L

    2015-01-01

    Introduction The treatment of displaced, extra-articular fractures of the distal tibia remains controversial. These injuries are difficult to manage due to limited soft tissue cover, poor vascularity of the area and proximity to the ankle joint. Surgical treatment options are expanding and include locked intramedullary nails, plate and screw fixation and external fixator systems. The nail and plate options are most commonly used in the UK, but controversy exists over which treatment is most clinically and cost-effective. In this multicentre randomised controlled trial we aim to assess ratings of disability 6 months postinjury in patients who have sustained a distal tibia fracture treated with either an intramedullary nail or plate and locking screw fixation. Methods and analysis Adult patients presenting at trial centres with an acute fracture of the distal tibia will be considered for inclusion. A total of 320 patients will provide 90% power to detect a difference of 8 points in Disability Rating Index (DRI) score at 6 months at the 5% level. The randomisation sequence is stratified by trial centre and age, and administered via web-based service with 1:1 treatment allocation. Baseline demographic and pre-injury functional data and radiographs will be collected using the DRI, Olerud and Molander, and EuroQol EQ-5D questionnaire. Clinical assessment, early complications and radiographs will be recorded at 6–8 weeks. Functional outcome, health-related quality of life and resource use will be collected at 3, 6 and 12 months postoperatively. The main analysis will investigate differences in DRI 6 months postsurgery, between the two treatment groups, on an intention-to-treat basis. Tests will be two-sided and considered to provide evidence for a significant difference if p values are <0.05. Ethics and dissemination NRES Committee West-Midlands, 6/11/2012 (ref:12/WM/0340). The results of the trial will be disseminated via peer-reviewed publications and

  11. Biomechanical comparison of the Locking Compression superior anterior clavicle plate with seven and ten hole reconstruction plates in midshaft clavicle fracture stabilisation.

    PubMed

    Eden, Lars; Doht, Stefanie; Frey, Sönke P; Ziegler, Dirk; Stoyhe, Jan; Fehske, Kai; Blunk, Torsten; Meffert, Rainer H

    2012-12-01

    The purpose of this study was to characterise the biomechanical properties of the seven hole superior anterior clavicle LCP (locking compression plate) and to compare these with the properties of commonly applied implants used for the stabilisation of clavicular midshaft fractures such as the locking 7- and ten hole reconstruction plate. Twenty-four synthetic clavicles were used. A transverse midshaft fracture was induced. The clavicles were fixed with angle stable clavicle LCPs, seven hole and ten hole reconstruction plates (n = 8 each). Twenty cycles of axial compression and torsion were performed for each sample, which was followed by 1,000 cycles of three point bending and ultimately bending to failure. Axial, torsional and cantilever bending stiffness were calculated from the data recorded. The clavicle LCP showed the highest overall stiffness compared to the seven and ten hole reconstruction plate. Significantly higher stiffness values were found for axial compression and external rotation. In the load-to-failure tests, the ten hole reconstruction plate especially showed early signs of plastic deformation, which might account for early plate insufficiency so frequently observed clinically. The results indicate that the clavicle LCP, as compared to the reconstruction plates, leads to superior biomechanical stability in the treatment of midshaft clavicle fractures.

  12. Fixation of Metacarpal Shaft Fractures: Biomechanical Comparison of Intramedullary Nail Crossed K-Wires and Plate-Screw Constructs.

    PubMed

    Curtis, Benjamin D; Fajolu, Olukemi; Ruff, Michael E; Litsky, Alan S

    2015-08-01

    Metacarpal (MC) fractures are very common, accounting for 18% of all fractures distal to the elbow. Many MC fractures can be treated non-operatively; however, some are treated most effectively with surgical stabilization, for which there are multiple methods. It was postulated that plates would have a significantly higher (P < 0.05) load to failure than crossed K(XK)-wires and that intramedullary metacarpal nails (IMNs) and XK-wires would have equivalent load to failure. Mid-diaphyseal transverse fractures were created in 36 synthetic metacarpals and stabilized using nails, XK-wires or non-locking plates. Three-point bending was performed with continuous recording of load and displacement. Statistical analysis was performed using single factor ANOVA and Scheffe's test. Statistical significance was defined as P < 0.05. Biomechanical testing revealed significant differences between groups in load-to-failure. Average load to failure was significantly greater in the plate (1669 ± 322 N) than the XK-wire (146 ± 56 N) or IMN (110 ± 43 N) groups. The loads to failure of the K-wires and nails were equivalent. Plates were 11 and 15 times stronger in three-point bending than the K-wires and nails, respectively. There was no statistically significant difference between strengths of the K-wires and nails. Although plates are the most stable means of fixation of midshaft metacarpal fractures, if minimally-invasive techniques are indicated, intramedullary nails may provide equivalent stability as commonly-used XK-wires. Although some studies have shown favorable clinical outcomes with IMNs, additional clinical correlation of these biomechanical results to fracture healing and outcomes is needed. © 2015 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

  13. In Vivo Syndesmotic Over-Compression After Fixation of Ankle Fractures with a Syndesmotic Injury

    PubMed Central

    Cherney, Steven M.; Haynes, Jacob A.; Spraggs-Hughes, Amanda; McAndrew, Christopher M.; Ricci, William M.; Gardner, Michael J.

    2015-01-01

    Objectives The goals of this study were to assess syndesmotic reductions utilizing computerized tomography (CT) scans, and to determine if malreductions were associated with certain injury types or reduction forceps. Design Prospective cohort Setting Urban Level 1 Trauma center Patients Twenty-seven patients with operatively treated syndesmotic injuries were recruited prospectively. Intervention Patients underwent postoperative bilateral CT scans of the ankle and hindfoot to assess syndesmotic reduction. The uninjured extremity was used as a control. Main outcome measurement Side-to-side differences of fibula position within the tibial incisura were measured at several anatomic points and analyzed based on injury type, the presence of posterior malleolar injury, level of fracture, and type of reduction forceps used. Results On average, operatively treated syndesmotic injuries were over-compressed (fibular medialization) by 1mm (p < .001) and externally rotated by 5° (p = .002) when compared to the uninjured extremity. The absence of a posterior malleolar injury and Weber B (OTA 44-B) fractures seemed to have a protective effect against malrotation, but not against over-compression. There was no difference in malreduction based on type of clamp used. Conclusions It is possible, and highly likely based on these data, to over-compress the syndesmosis when using a reduction forceps. Care should be taken to avoid over-compression, as this may affect ankle motion and functional outcome. This is the first in vivo series of syndesmotic over-compression to our knowledge. PMID:26295735

  14. Intramedullary plate fixation of a distal humerus fracture: a case report.

    PubMed

    Russell, George V; Pearsall, Albert W

    2002-05-01

    A case of a complex distal humeral fracture is presented. The patient lacked sufficient bony architecture to allow for conventional reconstruction. A technique is described using an intramedullary plate to obtain bony stabilization and permit early range of motion exercises.

  15. Immuno-inflammatory tissue reaction to stainless-steel and titanium plates used for internal fixation of long bones.

    PubMed

    Voggenreiter, Gregor; Leiting, Stefan; Brauer, Holger; Leiting, Peter; Majetschak, Matthias; Bardenheuer, Mark; Obertacke, Udo

    2003-01-01

    The immuno-inflammatory responses to stainless-steel (21 implants in 20 patients) and titanium plates (22 implants in 20 patients) used in the treatment of long bone fractures were studied immunohistochemically. All fractures healed without complications. In the soft tissue adjacent to the surface of the implants a dark discolouration of the tissue was visible in 18/21 stainless-steel and 20/22 titanium plates. Tissue specimens of all patients contained positive staining for macrophages (CD68-positive cells). Serial sections showed that the majority of cells were found to express the HLA-DR molecule indicating their activation. Many of the macrophages were surrounded by clusters of T-lymphocytes (CD3-positive cells). 17 out of 21 steel specimens and 15 out of 22 titanium specimens showed the infiltration of moderate amounts of cytotoxic T-lymphocytes (CD8-positive cells). Moderate amounts of B-lymphocytes (CD79alpha positive cells) were evident in four patients with steel and six patients with titanium implants. The results of the present study clearly demonstrate the presence of a marked inflammation and tissue reaction in the soft tissue covering stainless-steel and titanium plates used for internal fixation of fractures of long bones independently from the material used.

  16. Near Continuum Velocity and Temperature Coupled Compressible Boundary Layer Flow over a Flat Plate

    NASA Astrophysics Data System (ADS)

    He, Xin; Cai, Chunpei

    2017-04-01

    The problem of a compressible gas flows over a flat plate with the velocity-slip and temperature-jump boundary conditions are being studied. The standard single- shooting method is applied to obtain the exact solutions for velocity and temperature profiles when the momentum and energy equations are weakly coupled. A double-shooting method is applied if these two equations are closely coupled. If the temperature affects the velocity directly, more significant velocity slip happens at locations closer to the plate's leading edge, and inflections on the velocity profiles appear, indicating flows may become unstable. As a consequence, the temperature-jump and velocity-slip boundary conditions may trigger earlier flow transitions from a laminar to a turbulent flow state.

  17. Evaluation of poly(lactic-co-glycolic acid) plate and screw system for bone fixation.

    PubMed

    Park, Subin; Kim, Jin Hee; Kim, Il Hwan; Lee, Minsu; Heo, Suhak; Kim, Hong; Kim, Eun Hee; Choy, Young Bin; Heo, Chan Yeong

    2013-05-01

    In this study, we investigated the efficacy and safety of the recently developed modifiable bioabsorbable plates and screws, which are made of PLGA [poly(lactic-co-glycolic acids)]. An in vitro extract test and a mammalian erythrocyte micronucleus test revealed that neither cytotoxicity nor genotoxicity was observed with the plates and screws tested in this study. An in vivo mandible fracture model in rabbit was introduced to evaluate the in vivo efficacy and of the PLGA-based plates and screws. At 4, 6, 8, and 10 weeks after implantation, tissue specimens were taken from the implanted sites of the rabbits and a histologic analysis was performed for each of the specimens. After 4 weeks, the plate was covered by connective tissues and severe chronic active inflammation in soft tissue was observed. After 6 weeks, the inflammation decreased and some of the specimens exhibited new bone formation around the periosteum. After 8 and 10 weeks, new bone formation was observed with all samples, where almost no severe inflammation was involved, implying the healing of the fracture. Given these, it can be suggested that the biodegradable plate and screw system that we evaluated in this study is effective for treatment of mandible fracture, one of the regions under a high load-bearing condition. The adjustment process and the long-term follow-up study are in progress for clinical application of the plate and screw system introduced in this study.

  18. Column and Plate Compressive Strengths of Aircraft Structural Martials Extruded 0-1HTA Magnesium Alloy

    NASA Technical Reports Server (NTRS)

    Heimerl, George J; Niles, Donald E

    1947-01-01

    Column and plate compressive strengths of extruded 0-1HTA magnesium alloy were determined both within and beyond the elastic range from tests of flat end H-section columns and from local instability tests of H-, Z-, and channel section columns. These tests are part of an extensive research investigation to provide data on the structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircraft structures.

  19. Column and Plate Compressive Strengths of Aircraft Structural Materials: Extruded 24S-T Aluminum Alloy

    NASA Technical Reports Server (NTRS)

    Heimerl, George J.; Roy, J Albert

    1945-01-01

    Column and plate compressive strengths of extruded 24S-T aluminum alloy were determined both within and beyond the elastic range from tests of thin-strip columns and local-instability tests of H-, Z-,and channel-section columns. These tests are part of an extensive research investigation to provide data on the' structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircraft structures.

  20. Biomechanical Evaluation of Interfragmentary Compression At Tibia Plateau Fractures In Vitro Using Different Fixation Techniques: A CONSORT-Compliant Article: Erratum.

    PubMed

    2015-02-01

    [In the article "Biomechanical Evaluation of Interfragmentary Compression At Tibia Plateau Fractures In Vitro Using Different Fixation Techniques: A CONSORT-compliant" article, which appeared in Volume 94, Issue 1 of Medicine, a line denoting dual authorship was omitted. K. Kojima and B. Gueorguiev contributed equally to the article.].

  1. Carbon fiber reinforced plastic (CFRP) plates versus stainless steel dynamic compression plates in the treatment of fractures of the tibiae in dogs.

    PubMed

    Skirving, A P; Day, R; Macdonald, W; McLaren, R

    1987-11-01

    In a series of 14 dogs, fractures of both tibiae were caused by a "bone-breaker" designed in the authors' department and observed to produce a consistent and realistic canine fracture. One tibia was plated with a carbon fiber reinforced plastic (CFRP) plate and the other with a dynamic compression (DC) plate. Roentgenographic examination demonstrated healing of the CFRP-plated tibiae with abundant callus, and almost total remodeling of the fracture callus between ten and 20 weeks. Biomechanical testing by three-point bending revealed little difference between the strength of union of the fractures at 12-16 weeks. At 20 weeks, although the numbers were too small for statistical confirmation, the CFRP-plated tibiae were consistently stronger than the DC-plated tibiae.

  2. Compressive buckling of rectangular composite plates with a free-edge delamination

    NASA Astrophysics Data System (ADS)

    Suemasu, Hiroshi; Gozu, Katsuhisa; Hayashi, Kunio; Ishikawa, Takashi

    1995-02-01

    An experimental and analytical investigation is conducted on the compressive buckling behavior of orthotropic plates with a delamination. The plates, which have three simply supported edges and one free edge, are a simplified model of stiffener plates of a stiffened panel. A uniform width delamination is located at their free edges over the whole length. In the analysis, the Rayleigh-Ritz approximation method is adopted. A constrained point is introduced to allow the contact between the two delaminated surfaces. Imaginary springs about relative displacement and two relative slopes are introduced at the constrained point. With the constraint, buckling loads of physically admissible buckling modes can be obtained by ordinary buckling analysis. The global buckling load reduction is found to be significant and almost proportional to the delamination width. Local delamination buckling is found to occur when the delamination is located near the surface and its size is relatively large compared with that of the plate. The local buckling mode is different from the global one, and more wave number in loading direction and constrained points are necessary to obtain physically admissible solutions. The analytical results agree well with the experimental ones.

  3. Cranial fixation plates in cerebral magnetic resonance imaging: a 3 and 7 Tesla in vivo image quality study.

    PubMed

    Chen, Bixia; Schoemberg, Tobias; Kraff, Oliver; Dammann, Philipp; Bitz, Andreas K; Schlamann, Marc; Quick, Harald H; Ladd, Mark E; Sure, Ulrich; Wrede, Karsten H

    2016-06-01

    This study assesses and quantifies impairment of postoperative magnetic resonance imaging (MRI) at 7 Tesla (T) after implantation of titanium cranial fixation plates (CFPs) for neurosurgical bone flap fixation. The study group comprised five patients who were intra-individually examined with 3 and 7 T MRI preoperatively and postoperatively (within 72 h/3 months) after implantation of CFPs. Acquired sequences included T1-weighted magnetization-prepared rapid-acquisition gradient-echo (MPRAGE), T2-weighted turbo-spin-echo (TSE) imaging, and susceptibility-weighted imaging (SWI). Two experienced neurosurgeons and a neuroradiologist rated image quality and the presence of artifacts in consensus reading. Minor artifacts occurred around the CFPs in MPRAGE and T2 TSE at both field strengths, with no significant differences between 3 and 7 T. In SWI, artifacts were accentuated in the early postoperative scans at both field strengths due to intracranial air and hemorrhagic remnants. After resorption, the brain tissue directly adjacent to skull bone could still be assessed. Image quality after 3 months was equal to the preoperative examinations at 3 and 7 T. Image quality after CFP implantation was not significantly impaired in 7 T MRI, and artifacts were comparable to those in 3 T MRI.

  4. Surgical fixation of sternal fractures: preoperative planning and a safe surgical technique using locked titanium plates and depth limited drilling.

    PubMed

    Schulz-Drost, Stefan; Oppel, Pascal; Grupp, Sina; Schmitt, Sonja; Carbon, Roman Th; Mauerer, Andreas; Hennig, Friedrich F; Buder, Thomas

    2015-01-05

    Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the anterior chest wall or the flexion-compression injury of the trunk, there is a need to retain each sternal fragment in the correct position while neutralizing shearing forces to the sternum. Anterior sternal plating provides the best stability and is therefore increasingly used in most cases. However, many surgeons are reluctant to perform sternal osteosynthesis due to possible complications such as difficulties in preoperative planning, severe injuries to mediastinal organs, or failure of the performed method. This manuscript describes one possible safe way to stabilize different types of sternal fractures in a step by step guidance for anterior sternal plating using low profile locking titanium plates. Before surgical treatment, a detailed survey of the patient and a three dimensional reconstructed computed tomography is taken out to get detailed information of the fracture's morphology. The surgical approach is usually a midline incision. Its position can be described by measuring the distance from upper sternal edge to the fracture and its length can be approximated by the summation of 60 mm for the basis incision, the thickness of presternal soft tissue and the greatest distance between the fragments in case of multiple fractures. Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates prevents injuries to mediastinal organs and vessels. Transverse fractures and oblique fractures at the corpus sterni are plated longitudinally, whereas oblique fractures of manubrium, sternocostal separation and any longitudinally fracture needs to be stabilized by a transverse plate from rib to sternum to rib. Usually the high convenience of a patient is seen during follow up as well as a precise reconstruction of the sternal morphology.

  5. Surgical Fixation of Sternal Fractures: Preoperative Planning and a Safe Surgical Technique Using Locked Titanium Plates and Depth Limited Drilling

    PubMed Central

    Schulz-Drost, Stefan; Oppel, Pascal; Grupp, Sina; Schmitt, Sonja; Carbon, Roman Th.; Mauerer, Andreas; Hennig, Friedrich F.; Buder, Thomas

    2015-01-01

    Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the anterior chest wall or the flexion-compression injury of the trunk, there is a need to retain each sternal fragment in the correct position while neutralizing shearing forces to the sternum. Anterior sternal plating provides the best stability and is therefore increasingly used in most cases. However, many surgeons are reluctant to perform sternal osteosynthesis due to possible complications such as difficulties in preoperative planning, severe injuries to mediastinal organs, or failure of the performed method. This manuscript describes one possible safe way to stabilize different types of sternal fractures in a step by step guidance for anterior sternal plating using low profile locking titanium plates. Before surgical treatment, a detailed survey of the patient and a three dimensional reconstructed computed tomography is taken out to get detailed information of the fracture’s morphology. The surgical approach is usually a midline incision. Its position can be described by measuring the distance from upper sternal edge to the fracture and its length can be approximated by the summation of 60 mm for the basis incision, the thickness of presternal soft tissue and the greatest distance between the fragments in case of multiple fractures. Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates prevents injuries to mediastinal organs and vessels. Transverse fractures and oblique fractures at the corpus sterni are plated longitudinally, whereas oblique fractures of manubrium, sternocostal separation and any longitudinally fracture needs to be stabilized by a transverse plate from rib to sternum to rib. Usually the high convenience of a patient is seen during follow up as well as a precise reconstruction of the sternal morphology. PMID

  6. The results of volar locking plate fixation for the fragility fracture population with distal radius fracture in Japanese women.

    PubMed

    Kato, Shuichi; Tatebe, Masahiro; Yamamoto, Michiro; Iwatsuki, Katsuyuki; Nishizuka, Takanobu; Hirata, Hitoshi

    2014-02-01

    The purpose of this study was to determine whether volar locking plate fixation for distal radius fracture benefits the fragility fracture population as much as it benefits the non-fragility fracture population. This matched case-control study was conducted based on a multi-center clinical prospective cohort. A comparison of treatment outcomes after volar locking plate fixation was made between females 55 years of age and older (fragility fracture population) and males less than 75 years of age (non-fragility fracture population) by evaluating clinical, radiological, and subjective outcomes using Hand20, a validated patient-rated disability instrument. A total of 170 patients were enrolled in this study. The two cohorts were matched in terms of AO fracture type. The fragility fracture population group and the non-fragility fracture population group each consisted of 50 patients. All objective measurements including wrist range of motion and radiological evaluations, but excluding grip strength, were not significantly different between the two groups. However, the Hand20 at 18 months after surgery was worse in the fragility fracture population group than in the non-fragility fracture population group. Carpal tunnel syndrome was the most frequently encountered complication in the fragility fracture population group, with one case (2%) in the non-fragility fracture population group and six cases (12%) in the fragility fracture population group, but the difference was not significant. In conclusion, there was a significant deficit in the improvement in disability despite favorable radiological and functional outcomes in fragility fracture population patients. Therefore, the fragility fracture population, especially middle-aged or older women, needs to be informed about prolonged disability and the higher risk of upper extremity disorders prior to surgery.

  7. Biodegradable internal fixation plates enabled with X-ray visibility by a radiopaque layer of β-tricalcium phosphate and poly (lactic-co-glycolic acid).

    PubMed

    Shasteen, Catherine; Park, Keun Yung; Kwong, Seok Min; Jung, Sun Young; Lee, Seung Ho; Park, Chun Gwon; Kim, Myung Hun; Kim, Sukwha; Son, Woo-Chan; Choi, Tae Hyun; Choy, Young Bin

    2013-02-01

    Biodegradable polymer plates can be clinically used as an alternative to metal plates (e.g., titanium) for internal fixation, which, however, are not visible with X-ray imaging, often used for post-operative diagnostics. In this study, therefore, we prepared a biodegradable plate enabled with X-ray visibility by attaching a radiopaque layer on a biodegradable fixation plate in clinical use (Inion, Finland). A radiopaque layer was made of a fine powder of a radiopaque agent, β-tricalcium phosphate (TCP) and a biodegradable binder material, poly (lactic-co-glycolic acid) (PLGA), which were physically mixed without change in their chemical structure. The radiopacity increased as we increased the layer thicknesses from 0.5 mm to 1.3 mm. Regardless of layer thickness, however, the radiopacity decreased with time both in vitro and in vivo due to decreasing density of TCP in the layer by swelling and degradation of a binder material, PLGA. The in vivo study with rabbits revealed that a discernible image of the radiopaque plate could be obtained by X-ray for up to 21 days, also showing the overall biocompatibility 6 months after implantation. Therefore, we conclude that the radiopaque plate prepared in this work is a promising fixation device enabled with both X-ray visibility and biodegradability. Copyright © 2012 Wiley Periodicals, Inc.

  8. Functional outcome of extra-articular distal humerus fracture fixation using a single locking plate: A retrospective study.

    PubMed

    Trikha, Vivek; Agrawal, Prabhat; Das, Saubhik; Gaba, Sahil; Kumar, Arvind

    2017-01-01

    The optimal method for fixation of extra-articular distal humerus factures poses a management dilemma. Although various plate configurations have been proposed, anatomic shaped extra-articular distal humerus locking plates have emerged as a viable solution for these complex injuries. We assessed clinico-radiologic outcome in our retrospective case series of extra-articular distal humerus fractures managed with these plates. Forty-five patients of extra-articular distal humerus fractures, who were operated at our level 1 trauma centre between January, 2012 and December, 2016, were identified. After exclusion, 36 patients were available for the final assessment. All patients were operated with the triceps-reflecting modified posterior approach. Regular clinico-radiologic follow-up was done evaluating elbow functionality, fracture union, secondary displacement, non-union, implant failure and any complications; Mayo Elbow Performance score (MEPS) was used for the final functional assessment. Twenty-four (66.7%) male and 12 (33.3%) female patients constituted the study group, who had an average follow-up of 15 months. Preoperatively three patients and post-operatively one patient had radial nerve palsy; all had neurapraxia and recovered completely. Overall, 34 (94.4%) patients were adjudged to have complete radiological union within 3 months; 2 (5.5%) patients developed non-union. Mean flexion achieved was 122.9° ± 23°, and mean extension was -4.03° ± 6.5°; 1 patient with head injury developed flexion deformity of 45°. Average MEPS at the final follow-up was 90.8° ± 9.9°. Stable reconstruction and early initiation of physiotherapy are utilitarian to envision optimal outcome; the use of precontoured extra-articular distal humerus locking plates has yielded satisfactory results with minimal complications in our hands.

  9. Design criteria for steel tank shells in compression influenced by plate fabrication and welding distortion tolerances

    SciTech Connect

    Knoy, E.C.

    1994-12-31

    For almost 60 years, the design and construction of steel water storage tanks has most commonly been under the requirements of the American Water Works Association Standard D100 `Welded Steel Tanks for Water Storage.` For many years, the criteria for designing conical and double curved members under compression was not precisely defined by the AWWA Standard, as some designers considered the local buckling criteria to only be applicable to cylindrical tubular members. There have been varied opinions concerning design and tolerance philosophy. This paper will give an overview of these philosophies and will tell the importance of meeting these dimensional criteria. the method of calculating allowable deformations and measuring as-built deformations will be shown. Several examples of actual failures and laboratory and computer-simulated testing will be shown, leaving the attendee with a visual message of the importance of complying with the industry-accepted design, assembly, and welding techniques. A discussion of the safety of welded steel structures in public areas will also be included in the presentation. Engineering concern for the adequacy of current standards for the proper design and construction of composite tanks made of reinforced concrete and steel plate will be outlined. The reader will be made aware of the need for proper design, fabrication, and construction of tubular steel plate members subject to compressive loads.

  10. Anterior cervical fusion with interbody cage containing beta-tricalcium phosphate augmented with plate fixation: a prospective randomized study with 2-year follow-up.

    PubMed

    Dai, Li-Yang; Jiang, Lei-Sheng

    2008-05-01

    A variety of bone graft substitutes, interbody cages, and anterior plates have been used in cervical interbody fusion, but no controlled study was conducted on the clinical performance of beta-tricalcium phosphate (beta-TCP) and the effect of supplemented anterior plate fixation. The objective of this prospective, randomized clinical study was to evaluate the effectiveness of implanting interbody fusion cage containing beta-TCP for the treatment of cervical radiculopathy and/or myelopathy, and the fusion rates and outcomes in patients with or without randomly assigned plate fixation. Sixty-two patients with cervical radiculopathy and/or myelopathy due to soft disc herniation or spondylosis were treated with one- or two-level discectomy and fusion with interbody cages containing beta-TCP. They were randomly assigned to receive supplemented anterior plate (n = 33) or not (n = 29). The patients were followed up for 2 years postoperatively. The radiological and clinical outcomes were assessed during a 2-year follow-up. The results showed that the fusion rate (75.0%) 3 months after surgery in patients treated without anterior cervical plating was significantly lower than that (97.9%) with plate fixation (P < 0.05), but successful bone fusion was achieved in all patients of both groups at 6-month follow-up assessment. Patients treated without anterior plate fixation had 11 of 52 (19.2%) cage subsidence at last follow-up. No difference (P > 0.05) was found regarding improvement in spinal curvature as well as neck and arm pain, and recovery rate of JOA score at all time intervals between the two groups. Based on the findings of this study, interbody fusion cage containing beta-TCP following one- or two-level discectomy proved to be an effective treatment for cervical spondylotic radiculopathy and/or myelopathy. Supplemented anterior plate fixation can promote interbody fusion and prevent cage subsidence but do not improve the 2-year outcome when compared with those treated

  11. UK DRAFFT: a randomised controlled trial of percutaneous fixation with Kirschner wires versus volar locking-plate fixation in the treatment of adult patients with a dorsally displaced fracture of the distal radius.

    PubMed

    Costa, Matthew L; Achten, Juul; Plant, Caroline; Parsons, Nick R; Rangan, Amar; Tubeuf, Sandy; Yu, Ge; Lamb, Sarah E

    2015-02-01

    In high-income countries, 6% of all women will have sustained a fracture of the wrist (distal radius) by the age of 80 years and 9% by the age of 90 years. Advances in orthopaedic surgery have improved the outcome for patients: many such fractures can be treated in a plaster cast alone, but others require surgical fixation to hold the bone in place while they heal. The existing evidence suggests that modern locking-plate fixation provides improved functional outcomes, but costs more than traditional wire fixation. In this multicentre trial, we randomly assigned 461 adult patients having surgery for an acute dorsally displaced fracture of the distal radius to either percutaneous Kirschner-wire fixation or locking-plate fixation. The primary outcome measure was the Patient-Rated Wrist Evaluation© (PRWE) questionnaire at 12 months after the fracture. In this surgical trial, neither the patients nor the surgeons could be blind to the intervention. We also collected information on complications and combined costs and quality-adjusted life-years (QALYs) to assess cost-effectiveness. The baseline characteristics of the two groups were well balanced and over 90% of patients completed follow-up. Both groups of patients recovered wrist function by 12 months. There was no clinically relevant difference in the PRWE questionnaire score at 3 months, 6 months or 12 months [difference at 12 months: -1.3; 95% confidence interval (CI) -4.5 to 1.8; p=0.398]. There was no difference in the number of complications in each group and small differences in QALY gains (0.008; 95% CI -0.001 to 0.018); Kirschner-wire fixation represents a cost-saving intervention (-£727; 95% CI -£588 to -£865), particularly in younger patients. Contrary to the existing literature, and against the increasing use of locking-plate fixation, this trial shows that there is no difference between Kirschner wires and volar locking plates for patients with dorsally displaced fractures of the distal radius. A

  12. Analysis of behavior of simply supported flat plates compressed beyond the buckling load into the plastic range

    NASA Technical Reports Server (NTRS)

    Mayers, J; Budiansky, Bernard

    1955-01-01

    An analysis is presented of the postbuckling behavior of a simply supported square flat plate with straight edges compressed beyond the buckling load into the plastic range. The method of analysis involves the application of a variational principle of the deformation theory of plasticity in conjunction with computations carried out on a high-speed calculating machine. Numerical results are obtained for several plate proportions and for one material. The results indicate plate strengths greater than those that have been found experimentally on plates that do not satisfy straight-edge conditions. (author)

  13. Metaphyseal locking plate as a definitive external fixator for treating open tibial fractures--clinical outcome and a finite element study.

    PubMed

    Ma, Ching-Hou; Wu, Chin-Hsien; Tu, Yuan-Kun; Lin, Ting-Sheng

    2013-08-01

    We evaluated both the outcome of using a locking plate as a definitive external fixator for treating open tibial fractures and, using finite element analysis, the biomechanical performance of external and internal metaphyseal locked plates in treating proximal tibial fractures. Eight open tibial patients were treated using a metaphyseal locked plate as a low-profile definitive external fixator. Then, finite element models of internal (IPF) as well as two different external plate fixations (EPFs) for proximal tibial fractures were reconstructed. The offset distances from the bone surface to the EPFs were 6 cm and 10 cm. Both axial stiffness and angular stiffness were calculated to evaluate the biomechanical performance of these three models. The mean follow-up period was 31 months (range, 18-43 months). All the fractures united and the mean bone healing time was 37.5 weeks (range, 20-52 weeks). All patients had excellent or good functional results and were walking freely at the final follow-up. The finite element finding revealed that axial stiffness and angular stiffness decreased as the offset distance from the bone surface increased. Compared to the IPF models, in the two EPF models, axial stiffness decreased by 84-94%, whereas the angular stiffness decreased by 12-21%. The locking plate used as a definitive external fixator provided a high rate of union. While the locking plate is not totally rigid, it is clinically stable and may be advisable for stiffness reduction of plating constructs, thus promoting fracture healing by callus formation. Our patients experienced a comfortable clinical course, excellent knee and ankle joint motion, satisfactory functional results and an acceptable complication rate.

  14. Reconstruction plate fixation with bone graft for mid-shaft clavicular non-union in semi-professional athletes.

    PubMed

    Wentz, S; Eberhardt, C; Leonhard, T

    1999-01-01

    From 1993 to 1997, 22 semi-professional athletes (14 men and 8 women), aged 18-33 years (mountain bike racers, soccer players, handball players, swimmers, and short distance runners) with a non-union of the middle third of the clavicle were treated operatively by reconstruction plating and bone grafting. Fourteen clavicular non-unions were caused by falls. Eight non-unions were the result of a car, motorcycle, or bicycle accident. There were 19 atrophic and 3 hypertrophic non-unions. In all patients, initially a figure-of-eight strap or a sling was used for immobilization and no radiographic union was documented within 5 months. None of the athletes had gone back to their sports and all had pain and limitation of shoulder function. For open reduction and internal fixation, an AO 3.5-mm seven-hole reconstruction plate was used. The sclerotic bone ends were freshened and a cortical bone transplant or cancellous bone from the iliac crest (depending on the shortening of the clavicle) was packed around the fracture or between the reduced fracture ends. In all athletes, radiographic consolidation was achieved after an average of 14 weeks (range, 11-16 weeks) and the average increase in the Constant and Murley Score was from 79 points preoperatively to 97 points after surgery. No operative or postoperative complications occurred and all athletes returned to their sports.

  15. Outcome Analysis of Intra-Articular Scapula Fracture Fixation with Distal Radius Plate: A Multicenter Prospective Study

    PubMed Central

    Panigrahi, Ranajit; Madharia, Divya; Das, Dibya Singha; Samant, Saswat; Biswal, Manas Ranjan

    2016-01-01

    Background Scapula fractures occur in approximately 1% of all fractures and constitute about 3% - 5% of all injuries of the shoulder joint. Objectives This study aimed to evaluate the clinical outcomes of 20 surgically treated patients with displaced glenoid fractures after stabilization with distal radius plate. Methods Between 2012 and 2015, at 2 centers (HMCH & SHCE) of Bhubaneswar Odisha, we stabilized 20 scapular intra-articular fractures surgically with distal radius locking plate and studied the outcome of the surgeries. The outcome of the 20 fractures was determined using the Constant and Murley score. Both shoulders were assessed and the score on the injured side was given as a percentage of that on the uninjured side. Results The median score was 88% (mean 65%, range 30 to 100). The median score for strength was 21/25 (mean 19, range 0 to 25) and that for pain 11/15 (mean 11, range 5 to 15). The median functional score was 16/20 (mean 15, range 0 to 20). The mean range of active abduction of the shoulder was 135° (20 to 180), the mean range of flexion 138° (20 to 180) and the mean range of external rotation 38° (0 to 100). Five patients showed excellent result; 11 patients showed good result; three patients showed fair result and one patient had poor outcome according to the Constant-Murley score. A superficial infection settled with antibiotics after operation in one patient whose score at final follow-up was 96%. In one patient, delayed healing was reported because of infection. One patient with stiffness of the shoulder at six weeks underwent manipulation under anesthesia with a follow-up score of 81%. Conclusions Various fixation modalities have been described in the literature, however fixation of intra-articular fracture of glenoid with distal radius locking plate for articular reconstruction in the presented series provides good functional outcome with early restoration of the range of motion of the shoulder. PMID:28144606

  16. 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.

  17. Distal Radius Volar Rim Fracture Fixation Using DePuy-Synthes Volar Rim Plate

    PubMed Central

    Kachooei, Amir Reza; Tarabochia, Matthew; Jupiter, Jesse B.

    2016-01-01

    Background To assess the results of distal radius fractures with the involvement of the volar rim fixed with the DePuy-Synthes Volar Rim Plate. Case Description We searched for the patients with volar rim fracture and/or volar rim fractures as part of a complex fracture fixed with a volar rim plate. Ten patients met the inclusion criteria: three patients with type 23B3, six patients with type 23C, and one patient with very distal type 23A. The mean follow-up was 14 months (range: 2–26). Fractures healed in all patients. Of the three patients with isolated volar rim fractures (type 23B3), two patients had no detectable deficits in motion. These patients had an average Gartland and Werley score of 9 (range: 2–14). Of the other seven patients (six with type 23C and one with type 23A fracture), three patients healed with full range of motion and four had some deficits in range of motion. Two patients had excellent results, three had good results, and two had fair results using the Gartland and Werley categorical rating. One patient healed with a shortened radius and ulnar impingement requiring a second surgery for ulnar head resection arthroplasty. Literature Review Results after nonoperative treatment of volar rim fractures are not satisfactory and often require subsequent corrective osteotomy. Satisfactory outcomes are achieved when the fragments are well reduced and secured regardless of the device type. Clinical Relevance Volar rim plates give an adequate buttress of the volar radius distal to volar projection of the lunate facet and do not interfere with wrist mobility. Furthermore, the dorsal fragments can be fixed securely through the volar approach eliminating the need for a secondary posterior incision. However, patients should be informed of the potential problems and the need to remove the plate if symptoms develop. PMID:26855829

  18. Fixation of sternal fracture using absorbable plating system, three years follow-up

    PubMed Central

    Katballe, Niels; Pilegaard, Hans

    2015-01-01

    Sternal fractures occur due to severe chest wall trauma in a small number of patients. They are often conservatively treated. The surgical intervention, although controversial, is indicated in case of deformity, severe pain, and ventilatory complications. We report the first case where absorbable plate has been used to fix a traumatic fracture in a 42-year-old female. After 3 years, the patient is still free of symptoms and CT scanning reveals intact sternal bone structure. PMID:26101659

  19. Effects of ethylene oxide sterilization on 82: 18 PLLA/PGA copolymer craniofacial fixation plates.

    PubMed

    Pietrzak, William S

    2010-01-01

    Bioabsorbable devices are generally susceptible to some form of degradation or alteration of material properties in response to exposure to the terminal sterilization cycle. In addition to affecting the material strength, sterilization can also increase the rate of hydrolysis, both of which can impact clinical performance. The impact of sterilization on the material/device is unpredictable and must be empirically determined. This study examined the effects of ethylene oxide treatment on the material properties of LactoSorb 82:18 poly(L-lactic acid)-poly(glycolic acid) craniofacial plates. Compared with untreated control plates, there was no effect on the initial inherent viscosity (1.3 dL/g), the glass transition temperature (58 degrees C), or on the flexural mechanical properties. Furthermore, there was no effect on the in vitro rate of hydrolysis and mechanical strength loss profile. This provides evidence that the ethylene oxide sterilization cycle is compatible with these copolymer plates and that such treatment should not affect the clinical performance.

  20. The Northern Caribbean Plate Boundary Offshore Hispaniola: Strike-slip and Compressive Tectonic Processes

    NASA Astrophysics Data System (ADS)

    Corbeau, J.; Rolandone, F.; Leroy, S. D.; Mercier De Lepinay, B. F.; Meyer, B.; Ellouz, N.

    2014-12-01

    The boundary between the Caribbean plate and the North American plate is transpressive due to the oblique collision between these two plates. The transpressive movement is partitioned and accommodated in the Hispaniola region along two left-lateral strike-slip structures surrounding a fold-and-thrust belt. New multibeam bathymetry data and multichannel seismic reflection profiles have been recently collected during the Haiti-SIS and Haiti-SIS 2 cruises, along part of the northern Caribbean plate boundary between Cuba, Jamaica and Hispaniola. From the north to the south, three types of deformations are observed. In the Windward Passage, the analysis of the data set reveals that the movement on the Oriente fault between Cuba and Hispaniola is purely left-lateral strike-slip according to the GPS measurements. In the Gonave basin, west of Hispaniola, the deformation is compressive. A series of folds is identified and moves toward the southwest. The Enriquillo-Plantain-Garden Fault (EPGF) is localized in the Jamaica Passage, between Jamaica and Hispaniola. The analysis of the data set reveals that the left-lateral EPGF recently intersects inherited basins from the eastern Cayman Trough margin. The study of the actual EPGF active trace shows that this fault moves with a pure strike-slip component, at least in its western part: the presence of a little push-up structure and a set of three en echelon folds is highlighting in the western part of the Jamaica Passage. The shortening rate in the inherited basins crossed by the EPGF increases from west to east (5.8% to 8.5%), indicating that a thrusting component is also accommodated around the EPGF.

  1. Pancarpal Arthrodesis Without Rigid Coaptation Using the Hybrid Dynamic Compression Plate in Dogs.

    PubMed

    Ramirez, Juan M; Macias, Carlos

    2016-04-01

    To describe the complications, short- and long-term outcomes, and owner satisfaction for dogs treated with pancarpal arthrodesis (PCA) using the 2.7/3.5 mm locking and dynamic compression plate (DCP) hybrid pancarpal arthrodesis plate (hybrid DCP [HDCP]) without rigid coaptation in the postoperative period. Retrospective case series. Dogs with carpal injuries requiring PCA (n=15). Records (May 2007-October 2013) of dogs that had PCA using 3.5/2.7 mm HDCP (1 or 2 plates) and a Robert-Jones bandage were reviewed to determine intra- and post-operative complications and overall limb function. Follow-up was obtained by clinical evaluation at our institution and telephone interview of owners. Fourteen dogs had PCA stabilized with a single HDCP and 1 giant breed dog had PCA stabilized with 2 HDCP on the dorsal aspect of the carpus secured onto the 3rd and 4th metacarpal bones. Two dogs presented with bilateral injuries. Thirteen owners (87%) judged the results of surgery as excellent and 2 (13%) judged the results of surgery as good. Minor complications (4 limbs; 23%) were occasional episodes of mild lameness in 3 dogs and 3 episodes of discharging sinus tracts in a single dog. Major complications (3 limbs; 17%) included 1 surgical site infection and implant failure in a 43 kg dog with an active leishmaniasis infection and a concurrent bilateral sacro-iliac luxation. Two dogs developed episodes of discharging sinus tract and pain over the most distal screw that eventually necessitated plate removal. PCA without rigid coaptation can successfully be performed using the HDCP. © Copyright 2016 by The American College of Veterinary Surgeons.

  2. RAB-plate versus sliding hip screw for unstable trochanteric hip fractures: stability of the fixation and modes of failure--radiographic analysis of 218 fractures.

    PubMed

    Buciuto, R; Hammer, R

    2001-03-01

    The sliding hip screw has gained considerable acceptance in the treatment of unstable trochanteric fractures. However, the new type of 120 degrees fixed angle blade-plate with a buttress rod (RAB-plate) showed encouraging clinical results. The purpose of this study was to assess stability of fixation and analyze modes of failure in unstable trochanteric hip fractures treated with these devices. A retrospective radiographic review of 218 unstable fractures was performed. Linear and angular displacements of the major fragments and implant migration into the femoral head during healing were assessed. Additionally, adequacy of the reduction and the location of the implant within the femoral head as predictors of fixation failure were evaluated. The postreduction neck-shaft angle was maintained in the majority of the fractures in both groups. However, there was a significantly higher incidence of varus angulation by 10 degrees or more by the completion of healing among fractures treated with the sliding hip screw (p = 0.04). There was no statistically significant difference in vertical migration of the device into the femoral head between the implants used (p = 0.3). There was a significant relationship between failure of the fixation and varus reduction (p = 0.04) as well as screw/neck angle deviation more than 20 degrees in the lateral projection (p = 0.005) or if the implant was in a superior or posterior position (p = 0.02). The RAB-plate provided a more stable fixation, especially with regard to maintained postoperative alignment. However, positive predictors for fixation failure were identical for both devices. Here, the screw/neck angle deviation has had the strongest significance for prediction of fixation failure.

  3. [Humerus varus: correction by proximal valgus osteotomy with precontourned plate fixation in children].

    PubMed

    Tallón-López, J; Domínguez-Amador, J J; Andrés-García, J A

    2014-01-01

    Varus deformity of the proximal humerus in children is a little known pathology due to its low incidence of presentation. Progress has been made in recent years in understanding the possible etiology and pathophysiological causes. Radiological criteria for diagnosis and functional impairment that occurs have also been defined. However, there are few reports in the literature about the surgical treatment of this deformity in children. In this paper we present a case of surgical treatment of this deformity by corrective osteotomy fixed with precontoured external maleolar plate osteosynthesis.

  4. Ex vivo biomechanical comparison of a 3.5 mm locking compression plate applied cranially and a 2.7 mm locking compression plate applied medially in a gap model of the distal aspect of the canine radius.

    PubMed

    Uhl, Justin M; Kapatkin, Amy S; Garcia, Tanya C; Stover, Susan M

    2013-10-01

    To compare a medially applied 2.7 mm locking compression plate (LCP) to a cranially applied 3.5 mm LCP in a cadaveric distal radial fracture gap model. In vitro mechanical testing of paired cadaveric limbs Paired radii (n = 8) stabilized with either a 2.7 mm LCP medially or a 3.5 mm LCP cranially. Simulated distal radial comminuted fractures were created and stabilized with an LCP plate on the cranial surface in 1 limb, and on the medial surface in the contralateral limb. Gap stiffness, gap strain, and failure properties were compared between cranial and medial plate positions. Limb constructs were axially loaded, cyclically through 4 conditions that allowed mediolateral or craniocaudal bending at walk and trot loads, before monotonic failure loading. The effects of plate position on mechanical variables were assessed using paired t-tests. Gap stiffness was greater for cranial plate constructs than medial plate constructs for axial loading with mediolateral bending, but lower with craniocaudal bending. However, in loading that facilitated craniocaudal bending the medial plate construct also had bending apparent in the mediolateral direction. Gap strains for the different conditions followed similar trends as stiffness. Cranial plate constructs had significantly higher monotonic stiffness, yield, and failure loads. The larger, cranially applied LCP was biomechanically superior to the smaller, medially applied LCP in our distal radial fracture gap model, however the medial plate was superior to the cranial plate in cyclic loading allowing craniocaudal bending. © Copyright 2013 by The American College of Veterinary Surgeons.

  5. Minimally invasive plating versus either open reduction and plate fixation or intramedullary nailing of humeral shaft fractures: a systematic review and meta-analysis of randomized controlled trials.

    PubMed

    Hohmann, Erik; Glatt, Vaida; Tetsworth, Kevin

    2016-10-01

    The purpose of this study was to perform a meta-analysis comparing the clinical outcomes and complications between anterior humeral minimally invasive plate osteosynthesis (MIPO) and the 2 standard techniques, either open reduction and plating or humeral nailing. We performed a systematic review of Medline, Embase, Scopus, and Google Scholar to identify relevant randomized controlled trials in the English- and German-language literature. Eligibility criteria included randomized controlled trials comparing at least 1 surgical intervention with MIPO and reporting the primary clinical outcome using a validated functional scoring system and description of complications. Publication bias was assessed by funnel plot, and the risk of bias was established using the Cochrane Collaboration's Risk of Bias Tool. Heterogeneity was assessed using χ(2) and I(2) statistics. Eight prospective randomized studies (N = 376) met the eligibility criteria and were included in the analysis. The pooled estimate for clinical outcome showed that MIPO resulted in a significantly better outcome (standardized mean difference, 0.366; 95% confidence interval, 0.16 to 0.571; P = .0001; I(2) = 61%). The pooled estimate for all complications showed that the open reduction-internal fixation/nail group had a significantly higher complication rate (odds ratio, 0.507; 95% confidence interval, 0.285 to 0.905; P = .021; I(2) = 97%). Current evidence indicates the MIPO approach has better clinical outcomes with a lower rate of complications compared with alternative surgical techniques. However, the results of this meta-analysis are limited by problems inherent in the primary studies, including poor reporting of randomization protocols, as well as possible attrition bias and reporting bias, of the primary studies. Future publications may therefore change the trend of the pooled estimate in either direction. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees

  6. Morphologic evaluation of cervical spine anatomy with computed tomography: anterior cervical plate fixation considerations.

    PubMed

    Kwon, Brian K; Song, Frederick; Morrison, William B; Grauer, Jonathan N; Beiner, John M; Vaccaro, Alexander R; Hilibrand, Alan S; Albert, Todd J

    2004-04-01

    The computed tomography (CT) studies of the cervical spine from 50 males and 50 females were reviewed to provide morphometric data on a variety of anatomic parameters relevant to anterior cervical reconstruction and fixation. Measurements were made of the vertebral body width and midsagittal anteroposterior (AP) diameter and the distance between the medial borders of the longus coli muscles. Distances between adjacent endplates were also measured, both at their midpoint and at the anterior margin. Widths of the vertebral bodies measure 24.6 +/- 2.4 and 23.0 +/- 2.4 mm in males and females, respectively, with the narrowest measuring 17 and 14, respectively. The average midsagittal AP diameter of each vertebral body in males was approximately 17-18 mm, with the smallest AP diameter measured to be 13 mm. The average midsagittal AP diameter of each vertebral body in females was approximately 15-16 mm, with the smallest being 10 mm. CT scanning provides excellent osseous detail for the measurement of such parameters, and with its widespread use in the evaluation of cervical disorders, large numbers of patients can be reviewed.

  7. Hybrid Decompression and Fixation Technique Versus Plated 3-Vertebra Corpectomy for 4-Segment Cervical Myelopathy: Analysis of 81 Cases With a Minimum 2-Year Follow-Up.

    PubMed

    Odate, Seiichi; Shikata, Jitsuhiko; Kimura, Hiroaki; Soeda, Tsunemitsu

    2016-07-01

    A retrospective comparative study. The purpose of this study was to compare the stability and outcomes of a hybrid technique with those of a 3-vertebra corpectomy in the management of 4-segment cervical myelopathy. Patients with primarily ventral disease and loss of cervical lordosis are considered good candidates for anterior surgery. Cervical corpectomy is commonly performed in patients with multilevel cervical myelopathy. Corpectomies including >3 vertebraes entail an extremely high risk of reconstruction failure. To avoid the need to perform a 3-vertebra corpectomy, we use a hybrid decompression and fixation technique. This hybrid technique is a technique to obtain optimum decompression and fixation in patients with multilevel cervical myelopathy. A total of 81 patients with multilevel cervical myelopathy who underwent 4-segment cervical fixation with a minimum 2-year follow-up were included. The hybrid technique involved combining a plated 2-vertebra corpectomy and single-level discectomy with stand-alone cage fixation. This technique was performed in 39 patients, and the plated 3-vertebra corpectomy was performed in 42 patients. Nine patients (21%) who underwent the plated 3-vertebra corpectomy were treated with halo immobilization, but no patient in the hybrid group required this treatment (P=0.002). There were fewer instances of reconstruction failure in the hybrid group than in the 3-vertebra corpectomy group (0% vs. 10%, respectively; P=0.048) and fewer instances of C5 palsy (3% vs. 17%, respectively; P <0.0001). The incidence of postoperative C5 palsy was 25% for C3-C5 corpectomy, 19% for C4-C6 corpectomy, and 11% for C4-C5 corpectomy+C6-C7 discectomy. The hybrid technique has the following advantages over 3-vertebra corpectomy for 4-segment cervical fixation: a shorter graft bone and plate are required; the fixed segment has greater initial stability; postoperative external immobilization is simplified; and the risk of reconstruction failure and

  8. Large-deflection theory for end compression of long rectangular plates rigidly clamped along two edges

    NASA Technical Reports Server (NTRS)

    Levy, Samuel; Krupen, Philip

    1943-01-01

    The von Karman equations for flat plates are solved beyond the buckling load up to edge strains equal to eight time the buckling strain, for the extreme case of rigid clamping along the edges parallel to the load. Deflections, bending stresses, and membrane stresses are given as a function of end compressive load. The theoretical values of effective width are compared with the values derived for simple support along the edges parallel to the load. The increases in effective width due to rigid clamping drops from about 20 percent near the buckling strain to about 8 percent at an edge strain equal to eight times the buckling strain. Experimental values of effective width in the elastic range reported in NACA Technical Note No. 684 are between the theoretical curves for the extremes of simple support and rigid clamping.

  9. Percutaneous compression plating versus gamma nail for the treatment of pertrochanteric hip fractures

    PubMed Central

    Antonini, Guido; Delle Rose, Giacomo; Crippa, Cornelio

    2008-01-01

    The objective of this study is to compare percutaneous compression plating (PCCP) device with standard gamma nail (GN). A sample was prospectively followed and compared to a historical cohort: 82 intertrochanteric hip fractures in 81 patients treated with PCCP in 2004 versus 51 hip fractures treated with GN in 2003 (AO type 31A1, 31 A2). The main outcome measures were: surgery times, blood loss (Hb serum level and transfusions), complication, costs, for a 1-year follow-up. The minimally invasive PCCP technique resulted in a lower blood loss and consequently lower transfusion need (statistically significant), fewer implant-related complications and comparable surgery times. Overall surgical costs were lower for a comparable outcome in terms of healing and surgical time. PMID:18427918

  10. Mid-term outcome following revision surgery of clavicular non- and malunion using anatomic locking compression plate and iliac crest bone graft.

    PubMed

    Beirer, Marc; Banke, Ingo J; Harrasser, Norbert; Crönlein, Moritz; Pförringer, Dominik; Huber-Wagner, Stefan; Biberthaler, Peter; Kirchhoff, Chlodwig

    2017-03-29

    Treatment of clavicular non- and malunion is still challenging. Current surgical procedures often result in frustrating functional outcome along with high-grade subjective impairment and increased rates of revision surgery. However, the combination of biological augmentation with vital bone graft and a biomechanically sufficient fixation system seems to be a promising concept of treatment. In this retrospective study, 14 patients with a mean age of 44 years (26-67 years) suffering from non-union (n = 11) and/or malunion (n = 3) of the clavicle were enrolled. All patients were surgically treated using an anatomical precontoured locking compression plate (LCP) and autologous iliac crest bone graft. Functional outcome was assessed using the age- and sex-specific relative Constant Score. Mean follow-up was 27 months (range 12-44 months). The relative Constant Score significantly improved from preoperative 61 ± 8 (43-72) to 82 ± 10 (65-100) points at the final follow-up examination (p < 0.05). All patients showed bony union radiographically. One patient presented with a re-fracture of the clavicle nearly 3 years after revision surgery and 5 weeks after implant removal. Secondary fractures at the donor site of the anterior superior iliac spine were recorded in two patients. Iliac crest bone graft and anatomic locking plate fixation allow for a safe and adequate stabilization and radiographical bony union in non- and malunions of the clavicle with a high degree of patient satisfaction. However, secondary fractures of the anterior superior iliac spine constitute relevant complications and the time of hardware removal should be considered carefully.

  11. [Treatment of osteoporotic vertebral compression fractures with PMMA-augmented pedicle screw fixation].

    PubMed

    Padányi Csaba; Misik, Ferenc; Papp, Zoltán; Vitanovics, Dusan; Balogh, Attila; Veres, Róbert; Lipóth, László; Banczerowski, Péter

    2015-01-30

    Over the last few decades many innovative operation technique were developed due to the increase of porotic vertebral fractures. These new techniques aim to reach the required stability of the vertebral column. In case of significant instability, spinal canal stenosis or neural compression, decompressive intervention may be necessary, which results in further weakening of the column of the spine, the minimal invasive percutan vertebroplasty is not an adequate method to reach the required stability, that is why insertion of complementary pedicular screws is needed. Considering the limited screw-fixing ability of the porotic bone structure, with this new technique we are able to reach the appropriate stability of cement-augmented pedicle screws by dosing cement carefully through the screws into the vertebral body. We used this technique in our Institute in case of 12 patients and followed up the required stability and the severity of complications. Fifteen vertebral compression fractures of 12 patients were treated in our Institute. Using the classification proposed by Genant et al. we found that the severity of the vertebral compression was grade 3 in case of 13, while grade 2 in case of two fractures. The average follow up time of the patients was 22 months (12-39), during this period X-ray, CT and clinical control examinations were taken. During the surgery the involved segments were localised by using X-ray and after the exploration the canulated screws were put through the pedicles of the spine and the vertebral body was filled through the transpedicular screws with bone cement. Depending on the grade of the spinal canal stenosis, we made the decompression, vertebroplasty or corpectomy of the fractured vertebral body, and the replacement of the body. Finally the concerned segments were fixed by titanium rods. In all cases the stenosis of spinal canal was resolved and the bone cement injected into the corpus resulted in adequated stability of the spine. In case

  12. Results of Arthroscopic Ankle Arthrodesis with Fixation Using Two Parallel Headless Compression Screws in a Heterogenic Group of Patients

    PubMed Central

    Kolodziej, Lukas; Sadlik, Boguslaw; Sokolowski, Sebastian; Bohatyrewicz, Andrzej

    2017-01-01

    Background: As orthopedic surgeons become skilled in ankle arthroscopy technique and evidence -based data is supporting its use, arthroscopic ankle arthrodesis (AAA) will likely continue to increase, but stabilization methods have not been described clearly. We present a technique for two parallel 7.3-mm headless compression screws fixation (HCSs) for AAA in cases of ankle arthritis with different etiology, both traumatic and non-traumatic, including neuromuscular and inflammatory patients. Materials and Methods: We retrospectively verified 24 consecutive patients (25 ankles) who underwent AAA between 2011 and 2015. The average follow-up was 26 months (range 18 to 52 months). Arthrodesis was performed in 16 patients due to posttraumatic arthritis (in 5 as a sequela of pilon, 6 ankles, 3 tibia fractures, and 2 had arthritis due to chronic instability after lateral ligament injury), in 4 patients due to neuromuscular ankle joint deformities, and in 4 patients due to rheumatoid arthritis. Results: Fusion occurred in 23 joints (92%) over an average of 12 weeks (range 6 to 18 weeks). Ankle arthrodesis was not achieved in 2 joints (8%), both in post-pilon fracture patients. The correct foot alignment was not achieved in 4 feet (16%). None of the treated patients required hardware removal. Conclusion: The presented technique was effective in achieving a high fusion rate in a variety of diseases, decreasing intra- and post-operative hardware complications while maintaining adequate bone stability. PMID:28400871

  13. A finite element analysis of bone plates available for prophylactic internal fixation of the radial osteocutaneous donor site using the sheep tibia model.

    PubMed

    Avery, C M E; Bujtár, Péter; Simonovics, János; Dézsi, Tamás; Váradi, Károly; Sándor, George K B; Pan, Jingzhe

    2013-10-01

    The strengthening effect of prophylactic internal fixation (PIF) with a bone plate at the radial osteocutaneous flap donor site has previously been demonstrated using the sheep tibia model of the human radius. This study investigated whether a finite element (FE) model could accurately represent this biomechanical model and whether stress or strain based failure criteria are most appropriate. An FE model of an osteotomised sheep tibia bone was strengthened using 4 types of plates with unilocking or bicortical screw fixation. Torsion and 4-point bending simulations were performed. The maximum von Mises stresses and strain failure criteria were studied. The strengthening effects when applying stress failure criteria [factor 1.76-4.57 bending and 1.33-1.80 torsion] were comparable to the sheep biomechanical model [factor 1.73-2.43 bending and 1.54-2.63 torsion]. The strongest construct was the straight 3.5mm stainless steel unilocking plate. Applying strain criteria the strongest construct was the straight 3.5mm stainless DCP plate with bicortical screw fixation. The FE model was validated by comparison with the sheep tibia model. The complex biomechanics at the bone-screw interface require further investigation. This FE modelling technique may be applied to a model of the human radius and other sites. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  14. Linear stability analysis in compressible, flat-plate boundary-layers

    NASA Astrophysics Data System (ADS)

    Özgen, Serkan; Kırcalı, Senem Atalayer

    2008-01-01

    The stability problem of two-dimensional compressible flat-plate boundary layers is handled using the linear stability theory. The stability equations obtained from three-dimensional compressible Navier-Stokes equations are solved simultaneously with two-dimensional mean flow equations, using an efficient shoot-search technique for adiabatic wall condition. In the analysis, a wide range of Mach numbers extending well into the hypersonic range are considered for the mean flow, whereas both two- and three-dimensional disturbances are taken into account for the perturbation flow. All fluid properties, including the Prandtl number, are taken as temperature-dependent. The results of the analysis ascertain the presence of the second mode of instability (Mack mode), in addition to the first mode related to the Tollmien-Schlichting mode present in incompressible flows. The effect of reference temperature on stability characteristics is also studied. The results of the analysis reveal that the stability characteristics remain almost unchanged for the most unstable wave direction for Mach numbers above 4.0. The obtained results are compared with existing numerical and experimental data in the literature, yielding encouraging agreement both qualitatively and quantitatively.

  15. Recurrent sternal infection following treatment with negative pressure wound therapy and titanium transverse plate fixation.

    PubMed

    Gaudreau, Geneviève; Costache, Victor; Houde, Chanel; Cloutier, Daniel; Montalin, Livia; Voisine, Pierre; Baillot, Richard

    2010-04-01

    To provide a definition for recurrent sternal infection (RSI), analyse the risk factors and describe the management of this complication following treatment of deep sternal wound infection (DSWI) with horizontal titanium sternal osteosynthesis and coverage with pectoralis major myocutaneous flaps. Between 2002 and 2007, 10665 patients were submitted to open-heart surgery (OHS) in our institution, of whom 149 (1.4%) developed a DSWI. Negative pressure wound therapy (NPWT) followed by sternal osteosynthesis with musculocutaneous coverage was used in 92 (61.7%) patients. A retrospective review was done using a prospectively maintained database to identify risk factors for recurrent infection in this group of patients. Of the 92 patients who underwent sternal osteosynthesis, nine (9.8%) developed recurrent sternal infection requiring hardware removal. Univariate analysis showed that preoperative methicillin-resistant Staphylococcus aureus (MRSA) status (33.3% vs 6.1%; p=0.03) and prolonged intubation time in ICU (44.4% vs 14.6%; p<0.05) were significant risk factors. Two-thirds of these patients were also found to be infected with the same germ as the one responsible for their initial DSWI. No death was reported and sternal integrity was preserved in all patients despite plate removal. To lower the rate of RSI in patients treated with transverse sternal ostheosynthesis along with myocutaneous coverage for DSWI, surgeons must consider the MRSA preoperative status as a significant predictor of RSI and/or persistent infection. Chest-wall integrity in patients with RSI can be maintained after hardware removal, even after only a few weeks following initial plating. Copyright (c) 2009 European Association for Cardio-Thoracic Surgery. All rights reserved.

  16. Aerothermodynamics of compressible flow past a flat plate in the slip-flow regime

    NASA Astrophysics Data System (ADS)

    Cheng, Chi-Yang; Dai, Yi; Li, Genong; Hu, Yitao; Lai, Ming-Chia

    2015-11-01

    Compressible flow past a flat plate in the slip-flow regime features a very simple geometry and flow field, but it retains the most relevant and interesting physics in high-speed rarefied gas dynamics. In the slip-flow regime, the aerothermodynamic issues, especially the recovery factors and the convection heat transfer correlation, are the focus of this presentation. We first present the detailed similarity equations, especially the transformed Maxwell's slip and jump boundary conditions, and the equations for the Chapman-Rubesin parameter as well as how we incorporate the variable gas properties and the constitutive scaling model for the Knudsen layer in the similarity equations. The similarity solutions are compared with results published by E. R. van Driest [NACA Technical Note 2597, 1952]. We point out that van Driest's solutions were computed by using no-slip and no-jump boundary conditions. The recovery factor and Nusselt number of the plate are shown as functions of the Reynolds number and the Mach number. Finally, the similarity solutions are also compared with simulations of a two-dimensional computational fluid dynamics model solving the full Navier-Stokes-Fourier equations with slip and jump boundary conditions.

  17. Study of compression settlement of a three-layer rigid-plastic strip between parallel plates

    NASA Astrophysics Data System (ADS)

    Aleksandrov, S. E.; Goldstein, R. V.

    2014-11-01

    The process of compression settlement of a three-layer strip between parallel plates is investigated under the plane strain conditions. The inner layer of the strip is assumed to be made of a rigid-plastic hardening material, and the two outer layers are assumed to be ideally rigid-plastic. The boundary value problem has two symmetry axes. It is assumed that the strip thickness is much less than its width. The boundary conditions at the strip edge and at the center are satisfied in integral form. Two friction regimes, i.e., sliding and adhesion, are possible on the surface of contact between the strip and the plates and on the interface between the layers. It is shown that the general structure of the solution depends on the regimes realized at the moment. In particular, one of the layers can remain rigid at a certain stage of the deformation process. The differential equations are stated which permit exactly determining the conditions of the friction regime change and the state of each layer (rigid or plastic); these equations must be solved numerically. For some values of parameters of the boundary value problem, the velocity field is singular near one or both surfaces of friction. In these cases, it is necessary to calculate the strain rate intensity coefficient whose value probably controls the process of formation of a narrow layer with strongly changed properties near the corresponding surface of friction.

  18. Poor relation between biomechanical and clinical studies for the proximal femoral locking compression plate.

    PubMed

    Viberg, Bjarke; Rasmussen, Katrine M V; Overgaard, Søren; Rogmark, Cecilia

    2017-08-01

    Background and purpose - The proximal femur locking compression plate (PF-LCP) is a new concept in the treatment of hip fractures. When releasing new implants onto the market, biomechanical studies are conducted to evaluate performance of the implant. We investigated the relation between biomechanical and clinical studies on PF-LCP. Methods - A systematic literature search of relevant biomechanical and clinical studies was conducted in PubMed on December 1, 2015. 7 biomechanical studies and 15 clinical studies were included. Results - Even though the biomechanical studies showed equivalent or higher failure loads for femoral neck fracture, the clinical results were far worse, with a 37% complication rate. There were no biomechanical studies on pertrochanteric fractures. Biomechanical studies on subtrochanteric fractures showed that PF-LCP had a lower failure load than with proximal femoral nail, but higher than with angled blade plate. 4 clinical studies had complication rates less than 8% and 9 studies had complication rates between 15% and 53%. Interpretation - There was no clear relation between biomechanical and clinical studies. Biomechanical studies are generally inherently different from clinical studies, as they examine the best possible theoretical use of the implant without considering the long-term outcome in a clinical setting. Properly designed clinical studies are mandatory when introducing new implants, and they cannot be replaced by biomechanical studies.

  19. Volar Plate Fixation in Patients Older Than 70 Years with AO Type C Distal Radial Fractures: Clinical and Radiologic Outcomes.

    PubMed

    Piuzzi, Nicolas S; Zaidenberg, Ezequiel E; Duarte, Matias Pereira; Boretto, Jorge G; Donndorff, Agustin; Gallucci, Gerardo; De Carli, Pablo

    2017-08-01

    Introduction  Treatment of unstable distal radial fractures (DRFs) in elderly patients is controversial, and considering the increasing life expectancy, their appropriate treatment is of growing importance. Our aim was to analyze the clinical and radiologic outcomes in the elderly patients with AO type C DRF treated with volar locking plate (VLP). Materials and Methods  Between 2007 and 2011, 572 DRFs were operated on in our hospital with open reduction and internal fixation with VLP. Of these, only 64 patients (66 DRFs) met the selection criteria (AO type C DRF, age > 70 years, minimum 12-month follow-up). Mean follow-up was 28 months. Outcome assessment included range of motion, grip strength, VAS pain, Mayo Clinic Score, and DASH score. Analysis of pre- and postoperative radiographs was performed. Complications were recorded. Statistical analysis was performed comparing the results with the contralateral side. Results  Mean postoperative range of motion of the injured wrist compared with the control contralateral side was 86% for flexion ( p  < 0.001), 92% for extension ( p  < 0.001). The average DASH was 12. Mayo Clinic Wrist Score showed 43 excellent results, 15 good, 4 satisfactory, and 4 poor. Articular step-offs were reduced in 34 of 38 wrists. Five (7%) patients required plate removal. Conclusion  The treatment of articular DRF (AO type C) with VLP in the elderly patients achieved greater than 90% of the wrist range of motion and grip strength with no residual pain in greater than 90% of the patients. Level of Evidence  Therapeutic IV, case series.

  20. Critical Compressive Stress for Flat Rectangular Plates Supported Along All Edges and Elastically Restrained Against Rotation along the Unloaded Edges

    NASA Technical Reports Server (NTRS)

    Lundquist, Eugene E; Stowell, Elbridge Z

    1942-01-01

    A chart is presented for the values of the coefficient in the formula for the critical compressive stress at which buckling may be expected to occur in flat rectangular plates supported along all edges and, in addition, elastically restrained against rotation along the unloaded edges. The mathematical derivations of the formulas required in the construction of the chart are given.

  1. Reducing the risk of flexor pollicis longus tendon rupture after volar plate fixation for distal radius fractures: validation of the tendon irritation test.

    PubMed

    Suganuma, Seigo; Tada, Kaoru; Tsuchiya, Hiroyuki

    2014-12-01

    We have proposed that a positive tendon irritation test is suggestive of flexor pollicis longus (FPL) tendon damage that can lead to tendon rupture after volar plate fixation for distal radius fractures. We investigated cases of postsurgical hardware removal and validated the tendon irritation test as a way to elicit a sign of FPL tendon irritation. We performed hardware removal from 30 wrists in 28 consecutive patients after volar plate fixation. Subjects included 9 men and 19 women with an average age of 58.8 years. The duration of internal fixation averaged 14.5 months. We investigated the efficacy of the tendon irritation test to elicit a sign of tendon irritation before hardware removal, and we intraoperatively evaluated the presence of FPL tendon injuries. Twenty-four of 30 wrists exhibited a sign of tendon irritation. There was no statistical correlation between a sign of tendon irritation and patient age or the duration of internal fixation. We diagnosed 10 wrists with tenosynovitis and 8 frayed tendons. The sensitivity of the tendon irritation test to identify a sign of tendon irritation that was associated with FPL tendon injuries was 80.0%, and its specificity to correctly identify non-injured FPL tendons was 40.0%. The duration of internal fixation associated with tendon fraying was significantly longer than it was in cases of non-injured tendons and tenosynovitis. Our results suggest that subsequent examinations should be performed when the tendon irritation test is positive for signs of tendon irritation that may require plate removal.

  2. Biomechanical evaluation of the impact of various facet joint lesions on the primary stability of anterior plate fixation in cervical dislocation injuries: a cadaver study: Laboratory investigation.

    PubMed

    Oberkircher, Ludwig; Born, Sebastian; Struewer, Johannes; Bliemel, Christopher; Buecking, Benjamin; Wack, Christina; Bergmann, Martin; Ruchholtz, Steffen; Krüger, Antonio

    2014-10-01

    Injuries of the subaxial cervical spine including facet joints and posterior ligaments are common. Potential surgical treatments consist of anterior, posterior, or anterior-posterior fixation. Because each approach has its advantages and disadvantages, the best treatment is debated. This biomechanical cadaver study compared the effect of different facet joint injuries on primary stability following anterior plate fixation. Fractures and plate fixation were performed on 15 fresh-frozen intact cervical spines (C3-T1). To simulate a translation-rotation injury in all groups, complete ligament rupture and facet dislocation were simulated by dissecting the entire posterior and anterior ligament complex between C-4 and C-5. In the first group, the facet joints were left intact. In the second group, one facet joint between C-4 and C-5 was removed and the other side was left intact. In the third group, both facet joints between C-4 and C-5 were removed. The authors next performed single-level anterior discectomy and interbody grafting using bone material from the respective thoracic vertebral bodies. An anterior cervical locking plate was used for fixation. Continuous loading was performed using a servohydraulic test bench at 2 N/sec. The mean load failure was measured when the implant failed. In the group in which both facet joints were intact, the mean load failure was 174.6 ± 46.93 N. The mean load failure in the second group where only one facet joint was removed was 127.8 ± 22.83 N. In the group in which both facet joints were removed, the mean load failure was 73.42 ± 32.51 N. There was a significant difference between the first group (both facet joints intact) and the third group (both facet joints removed) (p < 0.05, Kruskal-Wallis test). In this cadaver study, primary stability of anterior plate fixation for dislocation injuries of the subaxial cervical spine was dependent on the presence of the facet joints. If the bone in one or both facet joints is damaged

  3. Internal fixation of mandibular angle fractures: a meta-analysis.

    PubMed

    Regev, Eran; Shiff, Jacob S; Kiss, Alex; Fialkov, Jeffrey A

    2010-06-01

    The degree of rigidity of internal fixation required for the treatment of mandibular angle fractures has long been at the center of debate in the literature. A statistical comparison between rigid fixation and monocortical fixation has been difficult because of multiple terms, definitions, and technical variations. The purpose of this study was to use the meta-analysis tool to combine information from multiple studies and to compare complication rates for different fixation methods. An English language literature search was conducted for articles on mandibular angle fractures. Information was collected on four variables of interest: compression/noncompression technique, monocortical/bicortical screws, number of plates, and location of plates. Five outcome rates were analyzed: infection, reoperation, hardware removal, malunion, and nonunion. Meta-analyses were run using Comprehensive Meta Analysis, version 2.2.03. Twenty-four studies with relevant data on the variables and outcomes of interest met the inclusion criteria. Significantly higher rates of infection, reoperation, and hardware removal were found for compression compared with noncompression, two plates compared with one plate, and for plates located on both the inferior and superior borders as compared with superior or inferior only. There were also significantly higher infection rates for bicortical screws compared with monocortical screws and higher malunion rates for compression compared with noncompression plating techniques. The results of this meta-analysis found lower complication rates with the use of noncompression, monocortical, and single-plate fixation, supporting the trend toward a single, superiorly placed, monocortical miniplate for fixation of mandibular angle fractures.

  4. Biomechanical and histological evaluation of the application of biodegradable poly-L-lactic cushion to the plate internal fixation for bone fracture healing.

    PubMed

    Fan, Yubo; Xiu, Kaihua; Duan, Hong; Zhang, Ming

    2008-01-01

    Internal plate fixation of fracture can provide favorable mechanical environment for fracture fragments. However, osteoporosis under the plate is often found, and refracture may occur after the plate is removed. There are two different opinions about the bone loss beneath the plate: first is the stress shielding effect brought by the rigid fixation, and the second is the insufficient blood supply of the bone caused by the placement of the plate. In this paper, we tried to achieve a favorable condition for the fracture healing by inserting a kind of biodegradable cushion, through which the stress shielding effect and the interruption of the bone blood supply could be relieved at the same time. Animal models of internal fixation for tibia diaphyseal fracture with the placement of the poly-l-lactic (PLLA) cushion between the plate and the bone were established; a series of in vitro investigations and finite element (FE) analysis were performed to evaluate the effect of this new internal fixation system. During both the initial and 50% healing periods, the extent of stress shielding of the fracture zone decreased due to the use of the PLLA cushion. Especially for the 50% healing stage, the insertion of the PLLA cushion on alleviating the stress shielding of the bone tissue between the inner two screws directly under the plate is more apparent than that at the initial healing period. Meanwhile, radiological and histological coloration results demonstrated sooner callus growth and better trabecular rearrangement of the fracture zone in the PLLA group with the degradation of the PLLA cushion during the healing periods. This study showed that the use of the PLLA cushion at the initial period did not impair the stability of the whole system, which provides a favorable mechanical environment for the following fracture healing. On the other hand, its superiorities on alleviating stress shielding effect and interruption with the blood supply of the bone tissue beneath the

  5. External Fixator for Maintaining Reduction Before Volar Plating: A Simple Treatment Method for Association of Osteosynthesis Type C3 Distal Radius Fracture.

    PubMed

    Tsai, Chun-Hao; Hsu, Chin-Jung; Wang, Ta-I; Fong, Yi-Chin; Hsu, Horng-Chaung; Lin, Tsung-Li

    2016-03-01

    Volar plating for Association of Osteosynthesis type C3 distal radius fractures involves more time and more radiation exposure because it is extremely difficult to simultaneously maintain the reduction and restore the congruity of the articular surface. The authors present a technique of maintaining the acceptable reduction by using an external fixator followed by open volar plating for restoring articular congruity. A consecutive series of 96 Association of Osteosynthesis type C3 distal radius fractures treated with the technique were retrospectively reviewed between January 2004 and December 2012. The technique makes surgery simpler and more effective, and reduces radiation exposure.

  6. Soft tissue repair for tibialis anterior tendon ruptures using plate and screw fixation technique in combination with anterolateral thigh flaps transplantation.

    PubMed

    Mao, Haijun; Xu, Guanyue

    2015-09-17

    Traumatic ruptures of the tibialis anterior tendon are rare but can cause substantial functional deficiencies. This study aimed to evaluate the feasibility of a surgery for soft tissue repair of traumatic rupture of the tibialis anterior tendon by using a plate and screw fixation repair in combination with the free anterolateral thigh flaps transplantation. Eight consecutive patients with anterior tibialis tendon ruptures who visited orthopedics departments from February 2008 to February 2012 were included in our study. The ruptured tendon was reconstructed with plate and screw fixation technique, and the tissue defects were repaired with anterolateral thigh free flaps. The complications and American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores were evaluated. Postoperative manual strength test was performed using a 0 to 5 scale. All flaps survived without any complications. The average preoperative and postoperative AOFAS ankle-hindfoot scores of the patients were 51 and 95, respectively. Good ankle dorsiflexion strength against strong resistance was observed in eight ankles postoperatively (manual strength of one patient was 4/5, the others were 5/5), and a substantial improvement in strength was noted compared with the preoperative examination. Soft tissue repair for tibialis anterior tendon rupture using plate and screw fixation technique in combination with anterolateral thigh flaps transplantation is a feasible technique and yield satisfactory results.

  7. Efficacy and safety of tension band wiring versus plate fixation in olecranon fractures: a systematic review and meta-analysis.

    PubMed

    Ren, Yi-Ming; Qiao, Hu-Yun; Wei, Zhi-Jian; Lin, Wei; Fan, Bao-You; Liu, Jun; Li, Ang; Kang, Yi; Liu, Shen; Hao, Yan; Zhou, Xian-Hu; Feng, Shi-Qing

    2016-11-14

    Olecranon fracture (OF) is a common upper limb fracture, and the most commonly used techniques are still tension band wiring (TBW) and plate fixation (PF). The aim of the current study is to discuss whether TBW or PF technique of internal fixation is better in the treatment of OFs, using the method of meta-analysis. The eligible studies were acquired from PubMed, CNKI, Embase, Cochrane Library, and other sources. The data were extracted by two of the coauthors independently and were analyzed by RevMan5.3. Standardized mean differences (SMDs), odds ratios (ORs), and 95% confidence intervals (CIs) were calculated. Cochrane Collaboration's Risk of Bias Tool and Newcastle-Ottawa Scale were used to assess risk of bias. Thirteen studies including 1 RCT and 12 observational studies were assessed. Our meta-analysis results showed that both in RCT and observational studies, there were no significant differences between the two groups in disabilities of the arm, shoulder and hand (DASH) (SMD = 0.07, 95% CI = -0.32 to 0.46, p = 0.73), improvement rate (OR = 0.76, 95% CI = 0.48-1.22, p = 0.26), range of motion (ROM), operation time (SMD = -0.51, 95% CI = -1.17 to 0.14, p = 0.12) and blood loss (SMD = -0.97, 95% CI = -2.06 to 0.11, p = 0.08). The overall estimate of complications indicated that the pooled OR was 2.61 (95% CI = 1.65-4.14, p < 0.0001), suggesting that the difference was statistically significant. We also compared the outcomes of patients with mayo type IIA OFs treated by TBW and PF in DASH and ROM and found no differences. Both TBW and PF interventions had treatment benefit in OFs. The current study reveals that there are no significant differences in DASH, improvement rate, ROM, operation time, and blood loss between TBW and PF for OFs. Due to the less complications, we recommend the PF approach as the optical choice for OFs. More high-quality studies are required to further confirm our results.

  8. Distal third humeri fractures treated using the Synthes™ 3.5-mm extra-articular distal humeral locking compression plate: clinical, radiographic and patient outcome scores.

    PubMed

    Fawi, Hassan; Lewis, James; Rao, Prasad; Parfitt, Dan; Mohanty, Khitish; Ghandour, Adel

    2015-04-01

    Conventional management protocols for distal humeral extra-articular fractures (e.g. conservative, double columnar plating) are often associated with complications. We aimed to describe our experience of using the Synthes™ 3.5-mm extra-articular distal humeral locking compression plate for treatment of extra-articular distal humeral fractures. We prospectively studied 23 consecutive patients who underwent fixation, in a tertiary trauma centre, over 2 years. Data, including patient demographics, duration of follow-up, patient satisfaction, visual analogue score (VAS), Oxford Elbow Score, and final outcome on discharge, were collected and analyzed. Of the 23 patients (12 males, 11 females; mean age 47.5 years; range 18 years to 89 years), all fractures united radiologically and clinically after the index procedure, with a mean time to fracture union of 15.7 weeks (range 9 weeks to 34 weeks) and a mean time to discharge of 17.8 weeks (range 13 weeks to 34 weeks). Oxford Elbow Score was 36.5 (range 11 to 48) at 4.6 months postoperatively; at 20 months follow-up, it was 40 (range 14 to 48) and the VAS was 8.5 (range 5 to 10). One patient had radial nerve neuropraxia pre-operatively, and one postoperatively, and both recovered uneventfully 3 months postoperatively. Neither superficial, nor deep infections were observed in this cohort. The present study reports satisfactory outcome with the usage of the Synthes plate for extra-articular fracture management. It has become the technique of choice in our centre because it provides excellent results.

  9. Screw augmentation reduces motion at the bone-implant interface: a biomechanical study of locking plate fixation of proximal humeral fractures.

    PubMed

    Schliemann, Benedikt; Seifert, Robert; Rosslenbroich, Steffen B; Theisen, Christina; Wähnert, Dirk; Raschke, Michael J; Weimann, Andre

    2015-12-01

    Shear forces at the bone-implant interface lead to a loss of reduction after locking plate fixation of proximal humeral fractures. The aim of the study was to analyze the roles of medial support screws and screw augmentation in failure loads and motion at the bone-implant interface after locking plate fixation of proximal humeral fractures. Unstable 3-part fractures were simulated in 6 pairs of cadaveric humeri and were fixed with a DiPhos-H locking plate (Lima Corporate, Udine, Italy). An additional medial support screw was implanted in 1 humerus of every donor. The opposite humerus was stabilized with a medial support screw and additional bone cement augmentation of the 2 anteriorly directed head screws. Specimens were loaded in the varus bending position. Stiffness, failure loads, plate bending, and the motion at the bone-implant interface were evaluated using an optical motion capture system. The mean load to failure was 669 N (standard deviation [SD], 117 N) after fixation with medial support screws alone and 706 N (SD, 153 N) after additional head screw augmentation (P = .646). The initial stiffness was 453 N/mm (SD, 4.16 N/mm) and 461 N/mm (SD, 64.3 N/mm), respectively (P = .594). Plate bending did not differ between the 2 groups. However, motion at the bone-implant interface was significantly reduced after head screw augmentation (P < .05). The addition of bone cement to augment anteriorly directed head screws does not increase stiffness and failure loads but reduces motion at the bone-implant interface. Thus, the risk of secondary dislocation of the head fragment may be reduced. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  10. 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

  11. The Clinical Usefulness of Ultrasound-Aided Fixation Using an Absorbable Plate System in Patients with Zygomatico-Maxillary Fracture

    PubMed Central

    Park, Jun Hyung

    2013-01-01

    Background Ultrasound-aided fixation is a recently developed alternative method of treatment of zygomatico-maxillary (ZM) fracture, and it can resolve the problems of excessive torsion force and subsequent fractures of screws. We conducted this study to evaluate the clinical usefulness of ultrasound-aided fixation as compared with the conventional fixation method using a drill and an expander in patients with ZM fracture. Methods We conducted a retrospective study in 35 patients with ZM fracture who had been treated at our hospital during a period ranging from March of 2008 to December of 2010. We divided them into two groups: an ultrasound-aided fixation group, comprising 13 patients who underwent ultrasound-aided fixation (SonicWeld Rx, KLS Martin), and a conventional group, comprising 22 patients who underwent conventional fixation (Biosorb FX, Linvatec Biomaterials Ltd.). We compared such variables as sex, direction, age at operation, follow-up period, operation duration, number of fixed holes, and time to discharge between the two groups. Results The ultrasound-aided fixation reduced the operation duration by about 30 minutes as compared with that of conventional fixation. There was no significant difference in follow-up period, number of fixed holes, or time to discharge between the two groups. Furthermore, there were no complications in either group. Conclusions The ultrasound-aided fixation of fractured ZM bone using an absorbable implant system is safe and effective in promptly reducing the bone fracture and providing satisfactory cosmetic outcomes over time. PMID:23898427

  12. Bioabsorbable bone fixation plates for X-ray imaging diagnosis by a radiopaque layer of barium sulfate and poly(lactic-co-glycolic acid).

    PubMed

    Choi, Sung Yoon; Hur, Woojune; Kim, Byeung Kyu; Shasteen, Catherine; Kim, Myung Hun; Choi, La Mee; Lee, Seung Ho; Park, Chun Gwon; Park, Min; Min, Hye Sook; Kim, Sukwha; Choi, Tae Hyun; Choy, Young Bin

    2015-04-01

    Bone fixation systems made of biodegradable polymers are radiolucent, making post-operative diagnosis with X-ray imaging a challenge. In this study, to allow X-ray visibility, we separately prepared a radiopaque layer and attached it to a bioabsorbable bone plate approved for clinical use (Inion, Finland). We employed barium sulfate as a radiopaque material due to the high X-ray attenuation coefficient of barium (2.196 cm(2) /g). The radiopaque layer was composed of a fine powder of barium sulfate bound to a biodegradable material, poly(lactic-co-glycolic acid) (PLGA), to allow layer degradation similar to the original Inion bone plate. In this study, we varied the mass ratio of barium sulfate and PLGA in the layer between 3:1 w/w and 10:1 w/w to modulate the degree and longevity of X-ray visibility. All radiopaque plates herein were visible via X-ray, both in vitro and in vivo, for up to 40 days. For all layer types, the radio-opacity decreased with time due to the swelling and degradation of PLGA, and the change in the layer shape was more apparent for layers with a higher PLGA content. The radiopaque plates released, at most, 0.5 mg of barium sulfate every 2 days in a simulated in vitro environment, which did not appear to affect the cytotoxicity. The radiopaque plates also exhibited good biocompatibility, similar to that of the Inion plate. Therefore, we concluded that the barium sulfate-based, biodegradable plate prepared in this work has the potential to be used as a fixation device with both X-ray visibility and biocompatibility.

  13. Magnetically launched flyer plate technique for probing electrical conductivity of compressed copper

    NASA Astrophysics Data System (ADS)

    Cochrane, K. R.; Lemke, R. W.; Riford, Z.; Carpenter, J. H.

    2016-03-01

    The electrical conductivity of materials under extremes of temperature and pressure is of crucial importance for a wide variety of phenomena, including planetary modeling, inertial confinement fusion, and pulsed power based dynamic materials experiments. There is a dearth of experimental techniques and data for highly compressed materials, even at known states such as along the principal isentrope and Hugoniot, where many pulsed power experiments occur. We present a method for developing, calibrating, and validating material conductivity models as used in magnetohydrodynamic (MHD) simulations. The difficulty in calibrating a conductivity model is in knowing where the model should be modified. Our method isolates those regions that will have an impact. It also quantitatively prioritizes which regions will have the most beneficial impact. Finally, it tracks the quantitative improvements to the conductivity model during each incremental adjustment. In this paper, we use an experiment on Sandia National Laboratories Z-machine to isentropically launch multiple flyer plates and, with the MHD code ALEGRA and the optimization code DAKOTA, calibrated the conductivity such that we matched an experimental figure of merit to +/-1%.

  14. Buckling Of Long Compression-Loaded Anisotropic Plates Restrained Against Inplane Lateral and Shear Deformations

    NASA Technical Reports Server (NTRS)

    Nemeth, Michael P.

    2003-01-01

    An approach for synthesizing buckling results and behavior for thin balanced and unbalanced symmetric laminates that are subjected to uniform axial compression loads and elastically restrained against inplane expansion, contraction, and shear deformation is presented. This approach uses a nondimensional analysis for infinitely long, flexurally anisotropic plates (coupling between bending and twisting) that are subjected to combined mechanical loads and is based on nondimensional parameters. In addition, nondimensional loading parameters are derived that account for the effects of the elastic inplane deformation restraints, membrane orthotropy, and membrane anisotropy on the induced prebuckling stress state. The loading parameters are used to determine buckling coefficients that include the effects of flexural orthotropy and flexural anisotropy. Many results are presented, for some selected laminates, that are intended to facilitate a structural designer's transition to the use of the generic buckling design curves that are presented and discussed in the paper. Several buckling response curves are presented that provide physical insight into the behavior for combined loads, in addition to providing useful design data. An example is presented that demonstrates the use of the generic design curves, which are applicable to a wide range of laminate constructions. The analysis approach and generic results indicate the effects and characteristics of laminate orthotropy and anisotropy in a very general and unifying manner.

  15. Magnetically launched flyer plate technique for probing electrical conductivity of compressed copper

    DOE PAGES

    Cochrane, Kyle R.; Lemke, Raymond W.; Riford, Z.; ...

    2016-03-11

    The electrical conductivity of materials under extremes of temperature and pressure is of crucial importance for a wide variety of phenomena, including planetary modeling, inertial confinement fusion, and pulsed power based dynamic materialsexperiments. There is a dearth of experimental techniques and data for highly compressed materials, even at known states such as along the principal isentrope and Hugoniot, where many pulsed power experiments occur. We present a method for developing, calibrating, and validating material conductivity models as used in magnetohydrodynamic(MHD) simulations. The difficulty in calibrating a conductivity model is in knowing where the model should be modified. Our method isolatesmore » those regions that will have an impact. It also quantitatively prioritizes which regions will have the most beneficial impact. Finally, it tracks the quantitative improvements to the conductivity model during each incremental adjustment. In this study, we use an experiment on Sandia National Laboratories Z-machine to isentropically launch multiple flyer plates and, with the MHD code ALEGRA and the optimization code DAKOTA, calibrated the conductivity such that we matched an experimental figure of merit to +/–1%.« less

  16. Long-term results after treatment of pertrochanteric femoral fractures with percutaneous compression plate (PCCP).

    PubMed

    Crespo, E; Gómez, S; Palacios, V; Galvez, J; Tenías, J M; Cano, I; Peñuela, R; Arcas, A; Crespo, R

    2016-08-01

    This study sought to evaluate the long-term osteosynthesis results for AO/OTA 31.A1-A2 pertrochanteric fractures treated with the percutaneous compression plate (PCCP). This investigation was a retrospective observational descriptive study of 335 patients, with a minimum follow-up of 2 years and a maximum follow-up of 8 years (2004-2011). The average post-operative hospital stay was 6.2 days, and the average decrease in haemoglobin levels after the intervention was 2.7 mg/dL, with transfusion required for one-third of the patients. Complications related to the implant were observed in 4.2 % of patients; the most notable complication was cut-out (2.4 % of patients), and 3 cases involved pseudarthrosis with breakage of the implant (0.9 % of patients). From the results obtained in this study and an analysis of previously published work, we believe that the PCCP may be the implant of choice for AO/OTA 31.A1-A2 fractures.

  17. A new, low cost, locking plate for the long-term fixation of a critical size bone defect in the ratfemur: in vivo performance, biomechanical and finite element analysis.

    PubMed

    Mataliotakis, George I; Tsouknidas, Alexander; Panteliou, Sofia; Vekris, Marios D; Mitsionis, Grigorios I; Agathopoulos, Simeon; Beris, Alexander E

    2015-01-01

    The optimum fixation device for the critical size bone defect is not established yet. A reliable, feasible and low-cost fixation device for the long-term maintenance of a critical bone defect. A custom-made plate made of poly-methyl-methacrylate was used for the fixation of a critical defect of rats' femurs. The screws were securely fixing both on the plate and the bone. A three point bending test, aimed to resemble the in vivo loading pattern, a Finite Element Analysis and a 24-week in vivo monitoring of the integrity of the plate fixation were utilized. The plate has linear and reproducible behavior. It presents no discontinuities in the stress field of the fixation. Its properties are attributed to the material and the locking principle. It fails beyond the level of magnitude of the normal ambulatory loads. In vivo, 100% of the plates maintained the bone defect intact up to 12 weeks and 85% of them at 24 weeks. This novel locking plate shows optimal biomechanical performance and reliability with high long-term in vivo survival rate. It is fully implantable, inexpensive and easily manufactured. It can be qualified for long term critical defect fixation in bone regeneration studies.

  18. Fatigue damage prognosis of internal delamination in composite plates under cyclic compression loadings using affine arithmetic as uncertainty propagation tool

    NASA Astrophysics Data System (ADS)

    Gbaguidi, Audrey J.-M.

    Structural health monitoring (SHM) has become indispensable for reducing maintenance costs and increasing the in-service capacity of a structure. The increased use of lightweight composite materials in aircraft structures drastically increased the effects of fatigue induced damage on their critical structural components and thus the necessity to predict the remaining life of those components. Damage prognosis, one of the least investigated fields in SHM, uses the current damage state of the system to forecast its future performance by estimating the expected loading environments. A successful damage prediction model requires the integration of technologies in areas like measurements, materials science, mechanics of materials, and probability theories, but most importantly the quantification of uncertainty in all these areas. In this study, Affine Arithmetic is used as a method for incorporating the uncertainties due to the material properties into the fatigue life prognosis of composite plates subjected to cyclic compressive loadings. When loadings are compressive in nature, the composite plates undergo repeated buckling-unloading of the delaminated layer which induces mixed modes I and II states of stress at the tip of the delamination in the plates. The Kardomateas model-based prediction law is used to predict the growth of the delamination, while the integration of the effects of the uncertainties for modes I and II coefficients in the fatigue life prediction model is handled using Affine arithmetic. The Mode I and Mode II interlaminar fracture toughness and fatigue characterization of the composite plates are first experimentally studied to obtain the material coefficients and fracture toughness, respectively. Next, these obtained coefficients are used in the Kardomateas law to predict the delamination lengths in the composite plates while using Affine Arithmetic to handle their uncertainties. At last, the fatigue characterization of the composite plates during

  19. Experimental and theoretical study of the buckling of narrow thin plates on an elastic foundation under compression

    NASA Astrophysics Data System (ADS)

    Kurguzov, V. D.; Demeshkin, A. G.

    2016-05-01

    The paper describes the processes of elastic deformation of thin films under mechanical loading. The film is modeled longitudinally by a compressed plate arranged on an elastic foundation. A computer model of the buckling of the narrow thin plate with a delamination portion located on an elastic foundation is constructed. This paper also touches upon the supercritical behavior of the plate-substrate system. The experiments on the axial compression of a metal strip adhered to a rubber plate are performed, and 2 to 7 buckling modes are obtained therein. The critical loads and buckling modes obtained in the numerical calculations are compared with the experimental data. It is shown that there is the possibility of progressive delamination of the metal plate from the foundation if the critical load is exceeded. It is found that the use of the proposed approach, which, in contrast to other approaches, accounts for the elastic deformation of the substrate, causes the dependence between the critical bending stress and the stiffness of the foundation.

  20. Dynamic plate osteosynthesis for fracture stabilization: how to do it

    PubMed Central

    Sonderegger, Juerg; Grob, Karl R.; Kuster, Markus S.

    2010-01-01

    Plate osteosynthesis is one treatment option for the stabilization of long bones. It is widely accepted to achieve bone healing with a dynamic and biological fixation where the perfusion of the bone is left intact and micromotion at the fracture gap is allowed. The indications for a dynamic plate osteosynthesis include distal tibial and femoral fractures, some midshaft fractures, and adolescent tibial and femoral fractures with not fully closed growth plates. Although many lower limb shaft fractures are managed successfully with intramedullary nails, there are some important advantages of open-reduction-and-plate fixation: the risk of malalignment, anterior knee pain, or nonunion seems to be lower. The surgeon performing a plate osteosynthesis has the possibility to influence fixation strength and micromotion at the fracture gap. Long plates and oblique screws at the plate ends increase fixation strength. However, the number of screws does influence stiffness and stability. Lag screws and screws close to the fracture site reduce micromotion dramatically. Dynamic plate osteosynthesis can be achieved by applying some simple rules: long plates with only a few screws should be used. Oblique screws at the plate ends increase the pullout strength. Two or three holes at the fracture site should be omitted. Lag screws, especially through the plate, must be avoided whenever possible. Compression is not required. Locking plates are recommended only in fractures close to the joint. When respecting these basic concepts, dynamic plate osteosynthesis is a safe procedure with a high healing and a low complication rate. PMID:21808699

  1. Endochondral growth in growth plates of three species at two anatomical locations modulated by mechanical compression and tension.

    PubMed

    Stokes, Ian A F; Aronsson, David D; Dimock, Abigail N; Cortright, Valerie; Beck, Samantha

    2006-06-01

    Sustained mechanical loading alters longitudinal growth of bones, and this growth sensitivity to load has been implicated in progression of skeletal deformities during growth. The objective of this study was to quantify the relationship between altered growth and different magnitudes of sustained altered stress in a diverse set of nonhuman growth plates. The sensitivity of endochondral growth to differing magnitudes of sustained compression or distraction stress was measured in growth plates of three species of immature animals (rats, rabbits, calves) at two anatomical locations (caudal vertebra and proximal tibia) with two different ages of rats and rabbits. An external loading apparatus was applied for 8 days, and growth was measured as the distance between fluorescent markers administered 24 and 48 h prior to euthanasia. An apparently linear relationship between stress and percentage growth modulation (percent difference between loaded and control growth plates) was found, with distraction accelerating growth and compression slowing growth. The growth-rate sensitivity to stress was between 9.2 and 23.9% per 0.1 MPa for different growth plates and averaged 17.1% per 0.1 MPa. The growth-rate sensitivity to stress differed between vertebrae and the proximal tibia (15 and 18.6% per 0.1 MPa, respectively). The range of control growth rates of different growth plates was large (30 microns/day for rat vertebrae to 366 microns/day for rabbit proximal tibia). The relatively small differences in growth-rate sensitivity to stress for a diverse set of growth plates suggest that these results might be generalized to other growth plates, including human. These data may be applicable to planning the management of progressive deformities in patients having residual growth.

  2. ENDOCHONDRAL GROWTH IN GROWTH PLATES OF THREE SPECIES AT TWO ANATOMICAL LOCATIONS MODULATED BY MECHANICAL COMPRESSION AND TENSION

    PubMed Central

    Stokes, Ian A.F.; Aronsson, David D.; Dimock, Abigail N.; Cortright, Valerie; Beck., Samantha

    2006-01-01

    SUMMARY Purpose Sustained mechanical loading alters longitudinal growth of bones, and this growth sensitivity to load has been implicated in progression of skeletal deformities during growth. The objective of this study was to quantify the relationship between altered growth and different magnitudes of sustained altered stress in a diverse set of non-human growth plates. Methods The sensitivity of endochondral growth to differing magnitudes of sustained compression or distraction stress was measured in growth plates of three species of immature animals (rats, rabbits, calves) at two anatomical locations (caudal vertebra and proximal tibia) with two different ages of rats and rabbits. An external loading apparatus was applied for eight days and growth was measured as the distance between fluorescent markers administered 24 and 48 hours prior to euthanasia. Results An apparently linear relationship between stress and percentage growth modulation (percent difference between loaded and control growth plates) was found, with distraction accelerating growth and compression slowing growth. The growth-rate sensitivity to stress was between 9.2 and 23.9% per 0.1 MPa for different growth plates, and averaged 17.1% per 0.1 MPa. The growth-rate sensitivity to stress differed between vertebrae and the proximal tibia (15 and 18.6 percent per 0.1 MPa respectively). The range of control growth rates of different growth plates was large (30 microns/day for rat vertebrae to 366 microns/day for rabbit proximal tibia). Conclusions The relatively small differences in growth-rate sensitivity to stress for a diverse set of growth plates suggests that these results might be generalized to other growth plates, including human. These data may be applicable to planning the management of progressive deformities in patients having residual growth. PMID:16705695

  3. Mechanical evaluation of two canine iliac fracture fixation systems.

    PubMed

    Vangundy, T E; Hulse, D A; Nelson, J K; Boothe, H W

    1988-01-01

    Twenty-three canine pelves were tested bilaterally to determine the stiffness and strength of intact ilium and stabilized oblique iliac osteotomies that simulated a common clinical fracture. Fixation systems tested were three 4.0 mm cancellous screws inserted ventral to dorsal across the osteotomy site and one laterally placed five hole 3.5 mm dynamic compression plate. Specimens were mechanically tested to failure under torsional, axial, or axial plus bending loads. Lag screw fixation was stiffer and stronger than plate fixation in all testing modes. The differences were statistically significant (p less than .05) in the torsional and axial plus bending loading modes. Fatigue testing was performed on implanted specimens with low-level cyclic loading under axial plus bending loading conditions. Physiologic loading conditions failed to produce mechanical failure of either fixation system after 100,000 cycles.

  4. Open reduction and internal fixation of capitellar fracture through anterolateral approach with headless double-threaded compression screws: a series of 16 patients.

    PubMed

    Vaishya, Raju; Vijay, Vipul; Jha, Gyanendra Kumar; Agarwal, Amit Kumar

    2016-07-01

    Fracture of the capitellum is an often missed or inadequately treated serious elbow injury. Anatomic reduction and proper stabilization are essential to obtain articular congruity so that late-onset arthritis can be avoided. The main areas of interest in this intriguing fracture are the choice of implant and the surgical approach. We describe the use of anterolateral approach and headless double-threaded compression screws for the fixation of this fracture. This prospective study included 16 capitellar fractures. A computed tomography scan was done for delineating the fracture line and planning the fixation technique. All fractures were treated with headless double-threaded compression screws using an anterolateral approach, over a period of 3 years, with a mean follow-up of 2.3 years (range, 1.5-4 years). The average time to bony union was 3.5 months (range, 2.5-5 months) with no malunion or nonunion. The mean range of flexion was 132° (range, 125°-135°). The average extensor lag was 10° (range, 0°-25°), but the range of motion remained functional in all patients. On the final follow-up, no evidence of osteonecrosis, post-traumatic osteoarthritis, or heterotrophic ossification was seen. The outcome was excellent in 10 patients, and 6 patients had a good result. The success of management of a capitellar fracture depends on an early diagnosis by keeping a high index of suspicion and timely management. Adequate exposure of the fracture is of paramount importance to achieve accurate reduction. This can be satisfactorily achieved by an anterolateral approach to the elbow. An adequate fixation of the fractured fragments can be achieved by the use of headless double-threaded compression screws. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  5. Charts relating the compressive buckling stress of longitudinally supported plates to the effective deflectional and rotational stiffness of the supports

    NASA Technical Reports Server (NTRS)

    Anderson, Roger A; Semonian, Joseph W

    1954-01-01

    A stability analysis is made of a long flat rectangular plate subjected to a uniform longitudinal compressive stress and supported along its longitudinal edges and along one or more longitudinal lines by elastic line supports. The elastic supports possess deflectional and rotational stiffness. Such configuration is an idealization of the compression cover skin and internal structure of a wing and tail surfaces. The results of the analysis are presented in the form of charts in which the buckling-stress coefficient is plotted against the buckle length of the plate for a wide range of support stiffnesses. The charts make possible the determination of the compressive buckling stress of plates supported by members whose stiffness may or may not be defined by elementary beam bending and twisting theory but yet whose effective restraint is amenable to evaluation. The deflectional and rotational stiffness provided by longitudinal stiffeners and full-depth webs is discussed and numerical examples are given to illustrate the application of the charts to the design of wing structures.

  6. Comparative efficacy of candling and glass plate compression for detection of diphyllobothriosis in rainbow trout (Oncorhynchus mykiss) musculature.

    PubMed

    Torres, P; Puga, S

    2011-12-01

    The efficiency of the direct candling technique on fillets (candling 1) was compared with examination of cuts 4 mm thick or less (candling 2) and glass plate compression for the detection of plerocercoids of Diphyllobothrium spp. in muscles of rainbow trout, Oncorhynchus mykiss. Application of the three procedures gave the following results (percentage of infected fish/percentage of isolated plerocercoids): candling 1: 40.9/22, candling 2: 29.5/18.8, glass plate compression: 29.5/59.2, and combination of candling 1 and 2: 70.5/40.8. The combination of the three techniques yielded 100% sensitivity: 44 infected fish were detected of 77 trout examined. When different regions of the musculature were compared using the three techniques, a high density of plerocercoids and the highest percentage of infection (90.9%; 40 infected trout) were detected in the ventral musculature. Candling 1, candling 2 and glass plate compression on the ventral musculature gave the following case numbers and percentages, respectively, for the total of 44 cases: 9 (20.5%), 9 (20.5%), and 22 (50%).

  7. Effects of adding injection-compression to rapid heat cycle molding on the structure of a light guide plate

    NASA Astrophysics Data System (ADS)

    Hong, Seokkwan; Min, Inki; Yoon, Kyunghwan; Kang, Jeongjin

    2014-01-01

    This study investigates the effects of adding injection-compression to rapid heat cycle molding (RHCM) (rapid heat cycle injection-compression molding (RICM)) on the physical quality and optical anisotropy of a molded light guide plate (LGP). Transcription ratio of microstructure, uniformity of part thickness and birefringence were experimentally evaluated on a 7 inch LGP of nominal thickness of 1.12 mm (including a microstructure array of 30 µm diameter and 14 µm height). The designed mold was equipped with rapid heating and compressing facilities and a microstructured nickel stamper was fabricated by UV LIGA process. In addition, to investigate the efficacy of RICM, experiments involving conventional injection molding (CIM), ICM, and RHCM were conducted in parallel with RICM using the same mold. RHCM and RICM yielded excellent transcription ratios for the microstructure, while CIM and RICM provided high thickness uniformity and low birefringence. Thus, RICM obtains high transcription ratio of microstructure, uniform thickness and low birefringence.

  8. A systematic review of open reduction and internal fixation of periprosthetic femur fractures with or without allograft strut, cerclage, and locked plates.

    PubMed

    Moore, Ryan E; Baldwin, Keith; Austin, Matthew S; Mehta, Samir

    2014-05-01

    Few comparative studies exist for open reduction and internal fixation of Vancouver B1 and C fractures. We therefore performed a systematic review of fractures treated with or without an allograft strut, and using various fixation techniques. Thirty-seven manuscripts including 682 fractures were identified between 1992 and 2012. Percent union was similar for Vancouver B1 fractures treated with or without an allograft strut (90.7% vs. 91.5%). Time to union (4.4 vs. 6.6 months) and deep infection (3.8% vs. 8.3%) were increased with use of allograft struts. Percent union and time to union were unaffected by plate type or use of cerclage. We conclude that due to increased infection and time to union, allograft struts should be used cautiously during operative treatment of Vancouver B1 factures.

  9. Average properties of compressible laminar boundary layer on flat plate with unsteady flight velocity

    NASA Technical Reports Server (NTRS)

    Moore, Franklin K; Ostrach, Simon

    1957-01-01

    The time-average characteristics of boundary layers over a flat plate in nearly quasi-steady flow are determined. The plate may be either insulated or isothermal. The time averages are found without specifying the plate velocity explicitly except that it is positive and has an average value.

  10. Multilevel anterior cervical discectomy and fusion with plate fixation for juvenile unilateral muscular atrophy of the distal upper extremity accompanied by cervical kyphosis.

    PubMed

    Guo, Xiang; Lu, Ming; Xie, Ning; Guo, Qunfeng; Ni, Bin

    2014-10-01

    A retrospective clinical study was conducted and related literatures were reviewed. This study aimed to evaluate outcome of multilevel anterior cervical discectomy and fusion with plate fixation for juvenile unilateral muscular atrophy of the distal upper extremity accompanied by cervical kyphosis. Juvenile unilateral muscular atrophy of the distal upper extremity is a rare disease. Traditional treatment uses a neck collar to immobilize neck motion. However, if the disease is accompanied by cervical kyphosis, conservative treatment is difficult to correct cervical kyphosis and the prognosis is worsened. Therefore, it is important to initially apply surgical treatment for juvenile unilateral muscular atrophy accompanied with cervical kyphosis. From March 2008 to May 2010, 4 patients were transferred to our spine medical center because of a history of slowly progressive distal weakness and atrophy of their hands and forearms. Four patients were diagnosed with Hirayama disease accompanied with cervical kyphosis based on their clinical representations and radiologic findings. After conservative treatment failed, these patients underwent multilevel anterior cervical discectomy and fusion with plate fixation. The clinical outcomes were retrospectively evaluated with follow-up ranging from 1.5 to 3 years. The clinical and radiologic follow-up indicated satisfactory clinical relief from symptoms, cervical sagittal alignment and cervical spinal canal volume, for all the patients. Within 6 months after surgery, the JOA score improved from a preoperative average of 14 to a postoperative average of 16.3; JOA recovery rates of all patients were more than good level. The muscle strengths of intrinsic muscles, wrist flexors and extensors, and biceps and triceps muscle improved on average by 1 grade. No complications occurred. Hirayama disease is a rare disease, a proper diagnosis of which can be made based on significant clinical symptoms and neurological imaging (dynamic MRI

  11. Complications during removal of conventional versus locked compression plates: is there a difference?

    PubMed

    Neumann, Hanjo; Stadler, Anne; Heuer, Hinrich; Auerswald, Marc; Gille, Justus; Schulz, Arndt Peter; Kienast, Benjamin

    2017-08-01

    Osteosynthesis plate removal is one of the most commonly performed procedures in orthopaedic surgery. Due to technological advances and the quality of increasing osteosynthesis material, more and more locked plates have been implanted over the last 20 years. The aim of this study was to determine whether the complication rate during plate removal differs between conventional and locked plates. In this retrospective cohort study, 620 patients were included and divided into two groups based on the type of plate (locked and conventional). Technical complications during implant removal included screw breakage, destroyed screw head, implant breakage, remaining implant material, refracture, bony or soft tissue overgrowth. The following plate-associated complications were identified: osteosynthesis plate not detachable, plate bent or broken, necessity of special tools or plate loosened. Three types of screw-related complications were observed: screw not detachable, screw broken or screw dislocated. Overall, complications related to the plate or screws were documented in 110 of the 620 cases. These complications occurred in 48 of the 382 cases involving conventional osteosynthesis (7.7% of all removals, 12.6% of all conventional removals) and in 62 of the 238 cases involving locked plate osteosynthesis (10.0% of all removals, 26.1% of all locked plate removals). The statistical analysis showed a significantly higher implant-related complication rate with locked plates compared to the conventional plates (p < 0.01). Hardware removal can be a complication-afflicted operation, especially cases involving locked-plate removal should only be performed if a strong indication is evident. Possible benefits of the procedure should be considered carefully, taking the cost-benefit ratio into account.

  12. Three-level and four-level anterior cervical discectomies and titanium cage-augmented fusion with and without plate fixation.

    PubMed

    Hwang, Shiuh-Lin; Lin, Chih-Lung; Lieu, Ann-Shung; Lee, Kung-Shing; Kuo, Tai-Hung; Hwang, Yan-Fen; Su, Yu-Feng; Howng, Shen-Long

    2004-09-01

    Cage-assisted anterior cervical discectomy and fusion (ACDF) has proven to be a safe and effective procedure for the treatment of one- and two-level degenerative disc disease (DDD). To the authors' knowledge, clinical results after three- and four-level interbody cage-augmented ACDF have not been reported in the literature. The authors investigated the safety and effectiveness of titanium cages used in such procedures and evaluated the results in cases with or without plate fixation. Fifty-six patients suffering from cervical DDD were divided into two groups. Group 1 included 32 patients who underwent titanium cage-assisted ACDF; Group 2 included 24 patients who underwent the same procedure, supplemented with plate fixation. The cervical DDD was confirmed by radiography and magnetic resonance imaging. The patients underwent radiographic evaluation to assess cervical lordosis, segmental height of cervical spine, the height of the foramina, and spinal stability. Neurological outcomes were assessed using the Japanese Orthopaedic Association (JOA) scores. Neck pain was graded using a 10-point visual analog scale (VAS). The follow-up period ranged from 13 to 28 months (mean 17.2 months). In both Groups 1 and 2 significant increase (p < 0.001) was demonstrated in the JOA scores (preoperatively 10.7 +/- 2.4 and 11.1 +/- 2, postoperatively 13.9 +/- 2.2 and 14.1 +/- 2.3, respectively) and VAS pain scores (preoperatively 8.8 +/- 0.9 and 8.5 +/- 1, postoperatively 3.1 +/- 2.1 and 2.8 +/- 1.8, respectively); however, there was no significant intergroup difference. A significant increase in the cervical lordosis, foraminal height, and segmental height was observed in both groups. Good stability of cage fusion was obtained in both groups 12 months postoperatively (90.6% in Group 1 and 91.7% in Group 2); however, there were no statistically significant intergroup differences. The complication rate in Group 2 was higher than that in Group 1. The hospital length of stay in Group 1

  13. Opening-wedge osteotomy, allografting with dual buttress plate fixation for severe genu recurvatum caused by partial growth arrest of the proximal tibial physis: a case report.

    PubMed

    Chen, Liang-Chin; Chan, Yi-Sheng; Wang, Ching-Jen

    2004-07-01

    Injuries to the proximal tibial physis are among the least common epiphyseal injuries. We present a case of severe genu recurvatum deformity (45 degrees) with leg length discrepancy (4 cm) following a neglected proximal tibial physeal injury incurred 6 years previously. The 16-year-old patient was successfully treated by open-wedge osteotomy, allograft reconstruction, and dual buttress plate fixation. At 3 years' follow-up, the patient was asymptomatic, fully active with a full range of motion (0 - 140 degrees) of the leg, and equal leg lengths. There were no signs of genu recurvatum clinically.

  14. The biomechanical performance of locking plate fixation with intramedullary fibular strut graft augmentation in the treatment of unstable fractures of the proximal humerus.

    PubMed

    Bae, J-H; Oh, J-K; Chon, C-S; Oh, C-W; Hwang, J-H; Yoon, Y-C

    2011-07-01

    We evaluated the biomechanical properties of two different methods of fixation for unstable fractures of the proximal humerus. Biomechanical testing of the two groups, locking plate alone (LP), and locking plate with a fibular strut graft (LPSG), was performed using seven pairs of human cadaveric humeri. Cyclical loads between 10 N and 80 N at 5 Hz were applied for 1,000,000 cycles. Immediately after cycling, an increasing axial load was applied at a rate of displacement of 5 mm/min. The displacement of the construct, maximum failure load, stiffness and mode of failure were compared. The displacement was significantly less in the LPSG group than in the LP group (p = 0.031). All maximum failure loads and measures of stiffness in the LPSG group were significantly higher than those in the LP group (p = 0.024 and p = 0.035, respectively). In the LP group, varus collapse and plate bending were seen. In the LPSG group, the humeral head cut out and the fibular strut grafts fractured. No broken plates or screws were seen in either group. We conclude that strut graft augmentation significantly increases both the maximum failure load and the initial stiffness of this construct compared with a locking plate alone.

  15. Extramedullary fixation implants and external fixators for extracapsular hip fractures in adults.

    PubMed

    Parker, Martyn J; Das, Avishek

    2013-02-28

    longer operation times for the Medoff plate along with a trend to a lower risk of fixation failure with the Medoff plate for unstable trochanteric fractures.Two trials of 676 participants compared the Medoff plate with three different screw-plate systems. There were no statistically significant differences in outcome for trochanteric fractures. For subtrochanteric fractures, there was a lower fixation failure rate for the Medoff plate but no evidence for differences in longer-term outcomes.Four trials of 396 participants comparing the Gotfried percutaneous compression plate (PCCP) with a SHS found a trend to lower blood loss and transfusion requirements for the PCCP but no other confirmed differences in outcomes between implants. Three of the trials reported intra-operative problems with the PCCP, some of which precluded its use.Three trials of 200 participants comparing external fixation with a SHS found less operative trauma for the external fixation. Final outcome appeared similar. The markedly increased fixation failure rate of fixed nail plates compared with the SHS is a major consideration and thus the SHS appears preferable.There was insufficient evidence from other comparisons of extramedullary implants or on the use of external fixators to draw definite conclusions.

  16. Buckling and postbuckling behavior of square compression-loaded graphite-epoxy plates with circular cutouts

    NASA Technical Reports Server (NTRS)<