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

PubMed

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

2010-03-01

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

Predictive Power of Distal Radial Metaphyseal Tenderness for Diagnosing Occult Fracture.

PubMed

Glickel, Steven Z; Hinojosa, Lauren; Eden, Claire M; Balutis, Elaine; Barron, O Alton; Catalano, Louis W

2017-10-01

To correlate the physical examination finding of distal radial metaphyseal tenderness with plain radiographic and magnetic resonance imaging after acute wrist injury to diagnose occult distal radius fractures. We hypothesized that persistent distal radial metaphyseal tenderness 2 weeks after acute injuries is predictive of an occult fracture. Twenty-nine adult patients presented, after acute trauma, with distal radial metaphyseal tenderness and initial plain radiographs and/or fluoroscopic images that did not show a distal radius fracture. Patients were reevaluated clinically and radiographically at approximately 2 weeks after initial presentation. Patients with persistent distal radial tenderness and negative radiographs underwent magnetic resonance imaging to definitively diagnose an occult distal radius fracture. We calculated the sensitivity and positive predictive value for persistent distal radial metaphyseal tenderness using a 95% confidence interval and standard formulas. Both radiographs and magnetic resonance imaging were used as our endpoint diagnosis for a distal radius fracture. We diagnosed 28 occult distal radius fractures, 8 by follow-up radiograph and 20 by magnetic resonance imaging. The positive predictive value for patients who completed the protocol was 96%. One patient who did not have an occult distal radius fracture had a fracture of the ulnar styloid. Tenderness of the distal radial metaphysis after wrist injury is strongly suggestive of a distal radius fracture despite both normal plain radiographs and fluoroscopic images. Diagnostic III. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Accuracy of specimen-specific nonlinear finite element analysis for evaluation of distal radius strength in cadaver material.

PubMed

Matsuura, Yusuke; Kuniyoshi, Kazuki; Suzuki, Takane; Ogawa, Yasufumi; Sukegawa, Koji; Rokkaku, Tomoyuki; Takahashi, Kazuhisa

2014-11-01

Distal radius fracture, which often occurs in the setting of osteoporosis, can lead to permanent deformity and disability. Great effort has been directed toward developing noninvasive methods for evaluating the distal radius strength, with the goal of assessing fracture risk. The aim of this study was to evaluate distal radius strength using a finite element model and to gauge the accuracy of finite element model measurement using cadaver material. Ten wrists were obtained from cadavers with a mean age of 89.5 years at death. CT images of each wrist in an extended position were obtained. CT-based finite element models were prepared with Mechanical Finder software. Fracture on the models was simulated by applying a mechanical load to the palm in a direction parallel to the forearm axis, after which the fracture load and the site at which the fracture began were identified. For comparison, the wrists were fractured using a universal testing machine and the fracture load and the site of fracture were identified. The fracture load was 970.9 N in the finite element model group and 990.0 N in the actual measurement group. The site of the initial fracture was extra-articular to the distal radius in both groups. The finite element model was predictive for distal radius fracture when compared to the actual measurement. In this study, a finite element model for evaluation of distal radius strength was validated and can be used to predict fracture risk. We conclude that a finite element model is useful for the evaluation of distal radius strength. Knowing distal radius strength might avoid distal radius fracture because appropriate antiosteoporotic treatment can be initiated.

Atypical distal radial fractures in children.

PubMed

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

2004-05-01

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

Reliability of the pronator quadratus fat pad sign to predict the severity of distal radius fractures.

PubMed

Loesaus, Julia; Wobbe, Isabel; Stahlberg, Erik; Barkhausen, Joerg; Goltz, Jan Peter

2017-09-28

To evaluate the reliability of pronator quadratus fat pad sign to detect distal radius fracture and to predict its severity. Retrospectively we identified 89 consecutive patients (41 female, mean age 49 ± 18 years) who had X-ray (CR) and computed tomography (CT) within 24 h following distal forearm trauma. Thickness of pronator quadratus fat pad complex (PQC) was measured using lateral views (CR) and sagittal reconstructions (CT). Pearson's test was used to determine the correlation of the PQC thickness in CR and CT. A positive pronator quadratus sign (PQS) was defined as a PQC > 8.0 mm (female) or > 9.0 mm (male). Frykman classification was utilized to assess the severity of fractures. Forty-four/89 patients (49%) had a distal radius fracture (Frykman I n = 3, II n = 0, III n = 10, IV n = 5, V n = 2, VI n = 2, VII n = 9, VIII n = 13). Mean thickness of the PQC thickness can reliably be measured on X-ray views and was 7.5 ± 2.8 mm in lateral views (CR), respectively 9.4 ± 3.0 mm in sagittal reconstructions (CT), resulting in a significant correlation coefficient of 0.795. A positive PQS at CR was present in 21/44 patients (48%) with distal radius fracture and in 2/45 patients (4%) without distal radius fracture, resulting in a specificity of 96% and a sensitivity of 48% for the detection of distal radius fractures. There was no correlation between thickness of the PQC and severity of distal radius fractures. A positive PQS shows high specificity but low sensitivity for detection of distal radius fractures. The PQC thickness cannot predict the severity of distal radius fractures.

Reliability of the pronator quadratus fat pad sign to predict the severity of distal radius fractures

PubMed Central

Loesaus, Julia; Wobbe, Isabel; Stahlberg, Erik; Barkhausen, Joerg; Goltz, Jan Peter

2017-01-01

AIM To evaluate the reliability of pronator quadratus fat pad sign to detect distal radius fracture and to predict its severity. METHODS Retrospectively we identified 89 consecutive patients (41 female, mean age 49 ± 18 years) who had X-ray (CR) and computed tomography (CT) within 24 h following distal forearm trauma. Thickness of pronator quadratus fat pad complex (PQC) was measured using lateral views (CR) and sagittal reconstructions (CT). Pearson’s test was used to determine the correlation of the PQC thickness in CR and CT. A positive pronator quadratus sign (PQS) was defined as a PQC > 8.0 mm (female) or > 9.0 mm (male). Frykman classification was utilized to assess the severity of fractures. RESULTS Forty-four/89 patients (49%) had a distal radius fracture (Frykman I n = 3, II n = 0, III n = 10, IV n = 5, V n = 2, VI n = 2, VII n = 9, VIII n = 13). Mean thickness of the PQC thickness can reliably be measured on X-ray views and was 7.5 ± 2.8 mm in lateral views (CR), respectively 9.4 ± 3.0 mm in sagittal reconstructions (CT), resulting in a significant correlation coefficient of 0.795. A positive PQS at CR was present in 21/44 patients (48%) with distal radius fracture and in 2/45 patients (4%) without distal radius fracture, resulting in a specificity of 96% and a sensitivity of 48% for the detection of distal radius fractures. There was no correlation between thickness of the PQC and severity of distal radius fractures. CONCLUSION A positive PQS shows high specificity but low sensitivity for detection of distal radius fractures. The PQC thickness cannot predict the severity of distal radius fractures. PMID:29098069

The correlation of initial radiographic characteristics of distal radius fractures and injuries of the triangular fibrocartilage complex.

PubMed

Kasapinova, K; Kamiloski, V

2016-06-01

Our purpose was to determine the correlation of initial radiographic parameters of a distal radius fracture with an injury of the triangular fibrocartilage complex. In a prospective study, 85 patients with surgically treated distal radius fractures were included. Wrist arthroscopy was used to identify and classify triangular fibrocartilage complex lesions. The initial radial length and angulation, dorsal angulation, ulnar variance and distal radioulnar distance were measured. Wrist arthroscopy identified a triangular fibrocartilage complex lesion in 45 patients. Statistical analysis did not identify a correlation with any single radiographic parameter of the distal radius fractures with the associated triangular fibrocartilage complex injuries. The initial radiograph of a distal radius fracture does not predict a triangular fibrocartilage complex injury. III. © The Author(s) 2016.

Hand Surgeon Reporting of Tendon Rupture Following Distal Radius Volar Plating

PubMed Central

Monaco, Nathan A.; Dwyer, C. Liam; Ferikes, Alex J.; Lubahn, John D.

2016-01-01

Background: Volar plate fixation with locked screws has become the preferred treatment of displaced distal radius fractures that cannot be managed nonoperatively. This treatment, however, is not without complication. The purpose of this study was to determine what percentage of hand surgeons, over a 12-month period, have experienced a tendon complication when using volar plates for the treatment of distal radius fractures. Methods: A total of 3022 hand surgeons were e-mailed a link to an online questionnaire regarding their observation and treatment of tendon injuries associated with volar plating of distal radius fractures. Responses were reported using descriptive statistics. Results: Of the 596 (20%) respondents, 199 (33%) surgeons reported encountering at least one flexor tendon injury after distal radius volar plating over the past year of practice. The flexor pollicis longus was the most commonly reported tendon injury (254, 75%). Palmaris longus grafting (118, 37%) and tendon transfer (114, 36%) were the most often reported treatments following this complication. A total of 216 respondents (36%) also encountered 324 cases of extensor tendon rupture after volar plating of distal radius fractures, with tendon transfer (88%) being the preferred treatment option. Conclusions: Both flexor and extensor tendon ruptures can be seen after volar plating of distal radius fractures. Surgeons should be aware of these complications. Critical assessment of hardware position at the time of index procedure is recommended to avoid complications. Long-term studies are needed to standardize approaches to managing tendon rupture following volar plating of distal radius fractures. PMID:27698628

Hand Surgeon Reporting of Tendon Rupture Following Distal Radius Volar Plating.

PubMed

Monaco, Nathan A; Dwyer, C Liam; Ferikes, Alex J; Lubahn, John D

2016-09-01

Background: Volar plate fixation with locked screws has become the preferred treatment of displaced distal radius fractures that cannot be managed nonoperatively. This treatment, however, is not without complication. The purpose of this study was to determine what percentage of hand surgeons, over a 12-month period, have experienced a tendon complication when using volar plates for the treatment of distal radius fractures. Methods: A total of 3022 hand surgeons were e-mailed a link to an online questionnaire regarding their observation and treatment of tendon injuries associated with volar plating of distal radius fractures. Responses were reported using descriptive statistics. Results: Of the 596 (20%) respondents, 199 (33%) surgeons reported encountering at least one flexor tendon injury after distal radius volar plating over the past year of practice. The flexor pollicis longus was the most commonly reported tendon injury (254, 75%). Palmaris longus grafting (118, 37%) and tendon transfer (114, 36%) were the most often reported treatments following this complication. A total of 216 respondents (36%) also encountered 324 cases of extensor tendon rupture after volar plating of distal radius fractures, with tendon transfer (88%) being the preferred treatment option. Conclusions: Both flexor and extensor tendon ruptures can be seen after volar plating of distal radius fractures. Surgeons should be aware of these complications. Critical assessment of hardware position at the time of index procedure is recommended to avoid complications. Long-term studies are needed to standardize approaches to managing tendon rupture following volar plating of distal radius fractures.

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.

A morphological and morphometric study of proximal and distal ends of dry radii with its clinical implications.

PubMed

Gupta, Chandni; Kalthur, Sneha Guruprasad; Malsawmzuali, J C; D'souza, Antony Sylvan

2015-01-01

Knowledge of the size and shape of radial head is essential for construction of radial head prosthesis. Further, the measurements of bicipital tuberosity and its angular relationship to radial head are significant in surgical techniques, like in the reconstruction of biceps tendon. Even the morphometry of the distal radius is significant in numerous clinical orthopedic situations such as reduction of distal radius fractures and in the design of distal radius prosthesis. So, the aim of the study was to determine the morphometric parameters of proximal and distal radius in dry adult Indian radius. Fifty intact adult Indian radius (right = 23, left = 27) were chosen, and the various parameters of proximal and distal ends of radius were studied. Student's t-test was done to correlate all these parameters on the right and left sides. The mean length of radius, height of head at medial and lateral ends, head anteroposterior and transverse diameter, head thickness at ventral, dorsal, and lateral ends were 23.5, 0.90, 0.75, 1.91, 1.85, 0.42, 0.32, and 0.30 cm, respectively. The mean depth of articular facet, length of neck, proximal and distal neck diameter, width and length of bicipital tuberosity, and radial circumference at bicipital tuberosity were 0.19, 1.19, 1.36, 1.31, 1.23, 1.97, and 4.54 cm, respectively. The mean length of styloid process, oblique and transverse width of lower end, anteroposterior diameter of lower end, and angle of radial inclination were 0.98cm, 2. 81cm, 2.59cm, 1.86cm, and 25.05°, respectively. This study will be useful for orthopedic surgeons in making prosthesis for the proximal and distal ends of radius.

Correlation between obesity and severity of distal radius fractures.

PubMed

Acosta-Olivo, C; Gonzalez-Saldivar, J C; Villarreal-Villarreal, G; Torres-Botello, A; Gomez-Garcia, E; Tamez-Mata, Y; Peña-Martinez, V

2017-04-01

The incidence of obesity has increased significantly worldwide. Our hypothesis was that patients with obesity have a more severe distal radius fracture and we realized a study to evaluate this correlation between obesity and severity of distal radius fractures caused by low-energy injuries. A total of 114 patients with distal radius fracture were examined in a cross-sectional, observational study. Fractures were classified according to the international AO-Müller/Orthopedic Trauma Association (AO/OTA) classification in order to determine the severity. The patient's Body Mass Index (BMI) was calculated and a Pearson correlation was performed. The patients were predominantly female, and left side was more frequently affected. Most of the fractures were AO/OTA type A (71 patients). The majority of the involved patients in our study were overweighed or obese. We do not observe a direct correlation between grade of obesity and distal radius fracture severity. Based on the results of this study obesity and severity of distal radius fractures do not correlate. Prognostic. Level IV. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Management of Complications of Distal Radius Fractures

PubMed Central

Chung, Kevin C.; Mathews, Alexandra L.

2015-01-01

Synopsis Treating a fracture of the distal radius may require the surgeon to make a difficult decision between surgical treatment and nonsurgical management. The use of surgical fixation has recently increased owing to complications associated with conservative treatment. However, conservative action may be necessary depending on certain patient factors. The treating surgeon must be aware of the possible complications associated with distal radius fracture treatments to prevent their occurrence. Prevention can be achieved with a proper understanding of the mechanism of these complications. This article discusses the most recent evidence on how to manage and prevent complications following a fracture of the distal radius. PMID:25934197

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

PubMed Central

Kopylov, Philippe; Geijer, Mats; Tägil, Magnus

2009-01-01

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

[Osteoconductive behaviour of beta-tricalcium phosphate ceramics in osteoporotic, metaphyseal bone defects of the distal radius].

PubMed

Hainich, J; von Rechenberg, B; Jakubietz, R G; Jakubietz, M G; Giovanoli, P; Grünert, J G

2014-02-01

Surgical treatment of osteoporotic distal radius fractures with locking plates does not completely prevent loss of reduction. Additional bone deficit stabilisation with the use of bone substitute materials is receiving increased attention. Most knowledge on the in vivo behavior of bone substitutes originates from a small number of animal models after its implantation in young, good vascularized bone. This paper investigates the osteoconductivity, resorption and biocompatibility of beta-tricalcium phosphate as a temporary bone replacement in osteoporotic type distal radius fractures. 15 bone samples taken from the augmented area of the distal radius of elderly people during metal removal were examined. The material was found to be osteoconductive, good degradable, and biocompatible. Degrading process and remodelling to woven bone seem to require more time than in available comparative bioassays. The material is suitable for temporary replacement of lost, distal radius bone from the histological point of view. © Georg Thieme Verlag KG Stuttgart · New York.

Pathologic fracture of the distal radius in a 25-year-old patient with a large unicameral bone cyst.

PubMed

Massen, Felix; Baumbach, Sebastian; Volkmer, Elias; Mutschler, Wolf; Grote, Stefan

2014-06-13

Distal radius fractures (DRF) are often referred to as osteoporosis indicator fractures as their incidence increases from age 45. In the group of young adults, distal radius fractures normally result from high-energy trauma. Wrist fractures in young patients without adequate trauma thus raise suspicion of a pathologic fracture. In this report we present the case of a fractured unicameral bone cyst (UBC) at the distal radius in a young adult.To the author's best knowledge, this is the first detailed report in an UBC at the distal radius causing a pathologic DRF in an adult patient. A 25-year-old otherwise healthy male presented to our Emergency Department after a simple fall on his right outstretched hand. Extended diagnostics revealed a pathologic, dorsally displaced, intra-articular distal radius fracture secondary to a unicameral bone cyst occupying almost the whole metaphysis of the distal radius. To stabilize the fracture, a combined dorsal and volar approach was used for open reduction and internal fixation. A tissue specimen for histopathological examination was gathered and the lesion was filled with an autologous bone graft harvested from the ipsilateral femur using a reamer-irrigator-aspirator (RIA) system. Following one revision surgery due to an intra-articular step-off, the patient recovered without further complications. Pathologic fractures in young patients caused by unicameral bone cysts require extended diagnostics and adequate treatment. A single step surgical treatment is reasonable if fracture and bone cyst are treated appropriately. Arthroscopically assisted fracture repair may be considered in intra-articular fractures or whenever co-pathologies of the carpus are suspected.

Pathologic fracture of the distal radius in a 25-year-old patient with a large unicameral bone cyst

PubMed Central

2014-01-01

Background Distal radius fractures (DRF) are often referred to as osteoporosis indicator fractures as their incidence increases from age 45. In the group of young adults, distal radius fractures normally result from high-energy trauma. Wrist fractures in young patients without adequate trauma thus raise suspicion of a pathologic fracture. In this report we present the case of a fractured unicameral bone cyst (UBC) at the distal radius in a young adult. To the author’s best knowledge, this is the first detailed report in an UBC at the distal radius causing a pathologic DRF in an adult patient. Case presentation A 25-year-old otherwise healthy male presented to our Emergency Department after a simple fall on his right outstretched hand. Extended diagnostics revealed a pathologic, dorsally displaced, intra-articular distal radius fracture secondary to a unicameral bone cyst occupying almost the whole metaphysis of the distal radius. To stabilize the fracture, a combined dorsal and volar approach was used for open reduction and internal fixation. A tissue specimen for histopathological examination was gathered and the lesion was filled with an autologous bone graft harvested from the ipsilateral femur using a reamer-irrigator-aspirator (RIA) system. Following one revision surgery due to an intra-articular step-off, the patient recovered without further complications. Conclusions Pathologic fractures in young patients caused by unicameral bone cysts require extended diagnostics and adequate treatment. A single step surgical treatment is reasonable if fracture and bone cyst are treated appropriately. Arthroscopically assisted fracture repair may be considered in intra-articular fractures or whenever co-pathologies of the carpus are suspected. PMID:24925068

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

PubMed

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

2005-12-01

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

[Comparative study on the strength of different mechanisms of operation of multidirectionally angle-stable distal radius plates].

PubMed

Rausch, S; Hoffmeier, K; Gueorguiev, B G; Klos, K; Gras, F; Hofmann, G O; Mückley, T

2011-12-01

Polyaxial angle-stable plating is thought to be particularly beneficial in the management of complex intra-articular fractures of the distal radius. The present study was performed to investigate the strength of polyaxial locking interfaces of distal radius plates. We tested the polyaxial interfaces of 3 different distal radius plates (2.4 mm Variable Angle LCP Two-Column Volar Distal Radius Plate, Synthes, Palmar Classic, Königsee Implantate and VariAx Plate Stryker). The strength of 0° and 10° screw locking angle was obtained during static loading. The strength of Palmar Classic with a 0° locking angle is significantly the best of all tested systems. With a 10° locking angle there is no significant difference between Palmar Classic, Two column Plate and VariAx Plate. The strength of polyaxial interfaces differs between the tested systems. A reduction of ultimate strength is due to increases of screw locking angle. The design of polyaxial locking interfaces should be investigated in human bone models. © Georg Thieme Verlag KG Stuttgart · New York.

Clinical and functional outcome of open primary repair of triangular fibrocartilage complex tears associated with distal radius fractures.

PubMed

Johandi, Faisal; Sechachalam, Sreedharan

2017-01-01

We evaluate the clinical and functional outcome of open primary repair of acute TFCC tears in distal radius fracture, when there is gross intraoperative distal radioulnar joint (DRUJ) instability after fixation of the distal radius, in the absence of an ulnar styloid fracture or when the ulnar fracture fragment is too small to be fixed. A retrospective review of our institution's distal radius fracture database over a 4-year period (January 2010 to December 2013). A total of 12 (1.38%) out of 3379 patients had an open TFCC repair in the same setting as fixation of distal radius. Assessment of outcome involved the analysis of objective and subjective clinical and functional outcomes. All patient regained Activities of Daily Living (ADL) independence; eleven out of 12 patients (91.7%) returned to pre-injury function and 8 out of 11 patients (72.7%) returned to their jobs. DRUJ stability was preserved in 10 patients (83.3%) with 10 patients (83.3%) having grip strength of at least 50%, compared to the uninjured hand, and 7 (58.3%) with grip strength of more than or equal to 75%. Complications of surgery identified can be classified into 4 broad categories: infection, neurological complications, persistent DRUJ instability and prolonged pain. The authors believe a primary open repair of the TFCC should be considered when patients present with instability during intra-operative DRUJ ballottement test after distal radius fixation, in the absence of an ulnar styloid fracture or when the ulnar fracture fragment is too small to be fixed.

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.

Alterations of bone density, microstructure, and strength of the distal radius in male patients with rheumatoid arthritis: a case-control study with HR-pQCT.

PubMed

Zhu, Tracy Y; Griffith, James F; Qin, Ling; Hung, Vivian W; Fong, Tsz-Ning; Au, Sze-Ki; Li, Martin; Lam, Yvonne Yi-On; Wong, Chun-Kwok; Kwok, Anthony W; Leung, Ping-Chung; Li, Edmund K; Tam, Lai-Shan

2014-09-01

In this cross-sectional study, we investigated volumetric bone mineral density (vBMD), bone microstructure, and biomechanical competence of the distal radius in male patients with rheumatoid arthritis (RA). The study cohort comprised 50 male RA patients of average age of 61.1 years and 50 age-matched healthy males. Areal BMD (aBMD) of the hip, lumbar spine, and distal radius was measured by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal radius provided measures of cortical and trabecular vBMD, microstructure, and biomechanical indices. aBMD of the hip but not the lumbar spine or ultradistal radius was significantly lower in RA patients than controls after adjustment for body weight. Total, cortical, and trabecular vBMD at the distal radius were, on average, -3.9% to -23.2% significantly lower in RA patients, and these differences were not affected by adjustment for body weight, testosterone level, or aBMD at the ultradistal radius. Trabecular microstructure indices were, on average, -8.1% (trabecular number) to 28.7% (trabecular network inhomogeneity) significantly inferior, whereas cortical pore volume and cortical porosity index were, on average, 80.3% and 63.9%, respectively, significantly higher in RA patients. RA patients also had significantly lower whole-bone stiffness, modulus, and failure load, with lower and more unevenly distributed cortical and trabecular stress. Density and microstructure indices significantly correlated with disease activity, severity, and levels of pro-inflammatory cytokines (interleukin [IL] 12p70, tumor necrosis factor, IL-6 and IL-1β). Ten RA patients had focal periosteal bone apposition most prominent at the ulnovolar aspect of the distal radius. These patients had shorter disease duration and significantly higher cortical porosity. In conclusion, HR-pQCT reveals significant alterations of bone density, microstructure, and strength of the distal radius in male RA patients and provides new insight into the microstructural basis of bone fragility accompanying chronic inflammation. © 2014 American Society for Bone and Mineral Research.

[Dynamic radioulnar convergence after Darrach operation, soft tissue stabilizing operations of the distal ulna and ulnar head prosthesis implantation--an experimental biomechanical study].

PubMed

Sauerbier, M; Hahn, M E; Fujita, M; Neale, P G; Germann, G; An, K N; Berger, R A

2002-08-01

The most common method of treating the arthrotic distal radioulnar joint (DRUJ) is resection of the entire ulnar head (Darrach procedure). Complications related to instability of the distal forearm resulting from loss of the ulnar head are usually manifested by pain and weak grip strength and have remained the drawbacks of this procedure. In an attempt to mechanically stabilize the distal forearm, an endoprosthesis was developed to replace the ulnar head after Darrach resection. The purpose of this study was to: 1) evaluate the dynamic effects of the Darrach procedure on radioulnar convergence; and 2) evaluate the mechanical efficacy of two soft tissue stabilizing techniques (Pronator quadratus advancement flap and ECU/FCU tenodesis) for the unstable distal ulnar stump and 3) the stability after the implantation of an ulnar head endoprosthesis following a Darrach resection on radioulnar convergence. With a dynamic PC-controled forearm simulator the rotation of 7 fresh-frozen cadaver upper extremities was actively and passively performed while loading relevant muscles. Resultant total forearm torque and the 3-dimensional kinematics of the ulna, radius and third metacarpal were recorded simultaneously. The implantation of the ulnar head endoprosthesis effectively restored the stability of the DRUJ. There were significantly better results after the implantation of the prosthesis compared with the Darrach and the soft tissue stabilization procedures. This study provides laboratory validity to the option of implanting an ulnar head endoprosthesis as an attempt to stabilize the distal forearm after Darrach resection in lieu of performing soft tissue stabilization techniques.

[The value of the Kapandji-Sauvé procedure with considering clinical results and measurement of bone density. A clinical study].

PubMed

Wüstner-Hofmann, M C; Schober, F; Hofmann, A K

2003-05-01

Between 1989 and 1995, 33 patients were treated with a Kapandji-Sauvé procedure for malunited fracture of the distal radius and instabilities of the distal radioulnar joint. Thirty patients were followed up with a mean follow-up time of 91 months. Fourteen patients underwent a measurement of bone density of the distal forearm. Twenty-eight patients showed good ossification of the distal radioulnar arthrodesis. Forearm rotation improved by 17.3 %. Mean grip strength was 72 % of that of the contralateral hand. Evaluation by the Cooney score resulted in 10 % very good, in 65 % good, 22 % fair and in 3 % poor results. The measurement of bone density of the distal radius showed an increase of rotation and flexure firmness. The cortical density remained constant. In the subcortical bone of the distal radius, we found a decrease of the trabecular density in the radial part.

Prostate-Specific Membrane Antigen Expression in Distal Radius Fracture.

PubMed

Hoberück, Sebastian; Michler, Enrico; Kaiser, Daniel; Röhnert, Anne; Zöphel, Klaus; Kotzerke, Jörg

2018-06-12

A 79-year old man with prostate cancer under active surveillance for 5 years was referred for a PSMA-PET/MRI for re-evaluation because of a rising prostate-specific antigen value. PET/MRI revealed a ribbonlike tracer accumulation in a healing fracture of the distal radius. This case illustrates that PSMA expression may occur in healing bone fractures in the distal radius. It can be assumed that benign causes of tracer accumulations in the upper extremities are missed in PET/CT due to elevated position of the arms during image acquisition.

Malpractice in distal radius fracture management: an analysis of closed claims.

PubMed

DeNoble, Peter H; Marshall, Astrid C; Barron, O Alton; Catalano, Louis W; Glickel, Steven Z

2014-08-01

Distal radius fractures comprise the majority of hand- and wrist-related malpractice claims. We hypothesized that a majority of lawsuits would be for malunions resulting from nonsurgical treatment. Additional goals of this study were to quantify costs associated with claims, determine independent risk factors for making an indemnity payment, and illustrate trends over time. Seventy closed malpractice claims filed for alleged negligent treatment of distal radius fractures by orthopedic surgeons insured by the largest medical professional liability insurer in New York State (NYS) from 1981 to 2005 were reviewed. We separately reviewed defendants' personal closed malpractice claim histories from 1975 to 2011. Overall incidence of malpractice claims among distal radius fractures treated in NYS was calculated using the NYS Statewide Planning and Research Cooperative System database and the 2008 American Academy of Orthopedic Surgeons census data. The overall incidence of malpractice claims for distal radius fracture management was low. Malunion was the most common complaint across claims regardless of treatment type. Claims for surgically treated fractures increased over time. A majority of claims documented poor doctor-patient relationships. Male plaintiffs in this group were significantly older than males treated for distal radius fractures in NYS. Most defendants had a history of multiple malpractice suits, all were male, and only a small percentage were fellowship-trained in hand surgery. Defendants lacking American Board of Orthopedic Surgery certification were significantly more likely to make indemnity payments. Thirty-eight of 70 cases resulted in an indemnity payment. Malunion and poor doctor-patient relationships are the major features of malpractice litigation involving distal radius fracture management. Older defendant age and lack of American Board of Orthopedic Surgery certification increase the likelihood of making an indemnity payment. Economic and decision analyses II. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Incidence and Functional Outcomes of Scapholunate Diastases Associated Distal Radius Fractures: A 2-year Follow-Up Scapholunate Dissociation.

PubMed

Lans, Jonathan; Lasa, Alejandro; Chen, Neal C; Jupiter, Jesse B

2018-01-01

The Scapholunate Interosseous Ligament (SLIL) is the first intrinsic carpal ligament to be injured in wrist trauma, present in up to 64% of the distal radius fractures. However, it remains unclear what patients develop symptoms, making primary treatment of these injuries accompanying distal radius fractures remains questionable. The aim of this study was to evaluate the functional outcomes of patients with scapholunate diastasis associated with distal radius fractures. We evaluated 391 patients with a distal radius fracture. Using Computer Tomography (CT) scans the scapholunate interval was measured. We identified 14 patients with an SLD (>3mm) of the injured wrist, which underwent a CT-scan of the contralateral wrist. To evaluate the functional outcomes at a mean follow up of 136±90 weeks, we used the Quick Disabilities of the Arm, Shoulder and Hand (qDASH) Score. There were 8 patients with bilateral SLD and 6 patients with unilateral SLD. Five patients had a qDASH score of 0 and one patient showed a qDASH score of 18.2. The patient with a poor score had bilateral preexisting osteoarthritis of the wrist. No patient had additional surgery of the SLIL. In patients with distal radius fractures, more than half of the 14 patients with an SL gap on CT had widening on the contralateral side. It is therefore worthwhile to image the contralateral wrist before diagnosing a SLD. The patients with unilateral SLD should not be surgically treated at initial presentation because they may have good functional outcomes after a follow up of 2 years.

Stabilization of Volar Ulnar Rim Fractures of the Distal Radius: Current Techniques and Review of the Literature

PubMed Central

O'Shaughnessy, Maureen A.; Shin, Alexander Y.; Kakar, Sanjeev

2016-01-01

Background Distal radius fractures involving the lunate facet can be challenging to manage. Reports have shown the volar carpal subluxation/dislocation that can occur if the facet is not appropriately stabilized. Literature Review Recent emphasis in the literature has underscored the difficulty in managing this fracture fragment, suggesting standard volar plates may not be able to adequately stabilize the fragment. This article reviews the current literature with a special emphasis on fixation with a specifically designed fragment-specific hook plate to secure the lunate facet. Case Description An extended flexor carpi radialis volar approach was made which allows access to the distal volar ulnar fracture fragment. Once provisionally stabilized with Kirschner wire fixation, a volar hook plate was applied to capture this fragment. Additional fracture stabilization was used as deemed necessary to stabilize the remaining distal radius fracture. Clinical Relevance The volar marginal rim fragment remains a challenge in distal radius fracture management. Use of a hook plate to address the volar ulnar corner allows for stable fixation without loss of reduction at intermediate-term follow-up. PMID:27104076

The role of post-operative radiographs in predicting risk of flexor pollicis longus tendon rupture after volar plate fixation of distal radius fractures - a case control study.

PubMed

Selvan, D R; Perry, D; Machin, D G; Brown, D J

2014-12-01

Volar plating of distal radius fractures is one of the common procedures performed in trauma surgery. Flexor pollicis longus (FPL) rupture has been described as complication following volar plating of distal radius fractures. The aim of our study was to investigate the possible relation between parameters measured on post-operative radiographs and the occurrence of FPL ruptures. This was a case control study. The post-operative radiographs of 11 FPL rupture, and 22 non-FPL rupture patients were reviewed with respect to fracture reduction and plate position and the various parameters were calculated by five independent people. Logistic regression was used to examine the importance of the variables. We identified two significant factors to predict FPL rupture after volar plating of distal radial fractures. These were radial tilt and plate distance from the joint line. The odds ratio of ruptures was 0.74 (95% CI 0.57-0.95) for every degree of radial tilt <25° and 0.50 (95% CI 0.28-0.88) for every millimetre that the distal end of the plate was away from the volar lip of the distal radius at the wrist joint. Post-operative radiographs could help us predict FPL rupture after distal radius volar plating. The findings also highlight the need for good fracture reduction and thoughtful placement of the volar plate intraoperatively to minimise the risk of FPL tendon rupture. Copyright © 2014 Elsevier Ltd. All rights reserved.

A new building block: costo-osteochondral graft for intra-articular incongruity after distal radius fracture.

PubMed

Tang, Chris Yuk Kwan; Fung, Boris; Poon, T L; Fok, Margaret

2014-01-01

Even with the invention of locking plates, intra-articular fractures of distal radius with extreme comminution remain a challenge for orthopaedic surgeons. Osteochondral graft is a potential choice to reconstruct the articular defect. We report a patient who had a fracture of distal radius with costo-osteochondral graft for articular reconstruction which has not yet been described in the English literature. At nine-year follow-up, he was pain free and had full range of movement of the wrist. The authors suggest that costo-osteochondral graft could be an option with satisfactory result.

Future treatment and research directions in distal radius fracture.

PubMed

Jupiter, Jesse

2012-05-01

Whether or not they will have their lives dramatically extended in the next few decades, it is clear that people are living longer, healthier, and more active lives. The two peak incidences of distal radius fractures will remain within the pediatric and geriatric age groups, with the latter experiencing a substantial increase in the coming years. This article attempts to project future developments with regard to epidemiology, risk and prevention, fracture assessment, and treatment of distal radius fractures, and the ever increasing concern for the economic impact of this prevalent injury. Copyright © 2012. Published by Elsevier Inc.

Ultrasound-guided diagnosis of fractures of the distal forearm in children.

PubMed

Herren, C; Sobottke, R; Ringe, M J; Visel, D; Graf, M; Müller, D; Siewe, J

2015-06-01

Distal radius and forearm fractures are injuries that are frequently seen in trauma surgery outpatient clinics. Usually, the wrist is X-rayed in 2 planes as standard diagnostic procedure. In contrast, we evaluate in our study the accuracy of ultrasonography (US) in diagnosing these fractures. This prospective study includes the patients who presented at two trauma surgery clinics with a presumptive diagnosis of distal radius or forearm fracture between January and December 2012. After a clinical examination, US imaging of the distal forearm was first carried out on 6 standardized planes followed by radiographs of the wrist made in two planes. The age limit was set at the end of 11 years. In total, 201 patients between 4 and 11 years of age were recruited with an average age of 9.5 years at the time of the trauma. There were 104 (51.7%) fractures distributed as follows: 89 (85.9%) injuries of the distal radius, 9 (8.7%) injuries of the distal ulna, and 6 (5.8%) combined injuries (radius and ulna). Sixty-five greenstick fractures were detected. Surgery was necessary in 34 cases. Specificity and sensitivity of ultrasound diagnosis were 99.5%. Ultrasound imaging is suitable to demonstrate fractures of the distal forearm. It is a highly sensitive procedure in detecting distal forearm fractures. In our opinion, a negative result in ultrasound may reduce the need for further radiographs in children with distal forearm lesions. But in any doubtful situation the need for conventional radiographs remains. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

What counts: outcome assessment after distal radius fractures in aged patients.

PubMed

Goldhahn, Jörg; Angst, Felix; Simmen, Beat R

2008-09-01

Outcome of surgical interventions at the distal radius does not only depend on the type of intervention used, it also depends on the way the outcome is measured. Substantial differences in outcome assessment between different measurement tools and poor correlation among them result in the question about the best instrument for the evaluation of treatment after distal radius fractures. The aim of the review is to discuss pros and cons of the parameters that are available to assess the outcome after distal radius fractures. The review should help to choose the appropriate instruments for a given research question in aged patients with distal radius fractures. Objective and subjective measures were reviewed with respect to their suitability in outcome assessment. Radiological parameters like inclination, palmar slope, and length of the radius are most common and used to determine especially surgical success. Grip strength and range of motion are considered objective and used as study endpoints in many studies. Functional tests like the Jebsen test provide a realistic feedback about disability but require special skills and resources of the testing personnel. Patient self-assessment adds perceived patient benefit. The patient-rated wrist evaluation (PRWE) provides a reliable and valid instrument for subjective outcome assessment. A combination of objective and subjective parameters should be used to assess the outcome of different treatment strategies due to the known discrepancies. Objective parameters like shortening, radial shift, or others should be clearly defined in the study methodology.

Distal radius osteotomy with volar locking plates based on computer simulation.

PubMed

Miyake, Junichi; Murase, Tsuyoshi; Moritomo, Hisao; Sugamoto, Kazuomi; Yoshikawa, Hideki

2011-06-01

Corrective osteotomy using dorsal plates and structural bone graft usually has been used for treating symptomatic distal radius malunions. However, the procedure is technically demanding and requires an extensive dorsal approach. Residual deformity is a relatively frequent complication of this technique. We evaluated the clinical applicability of a three-dimensional osteotomy using computer-aided design and manufacturing techniques with volar locking plates for distal radius malunions. Ten patients with metaphyseal radius malunions were treated. Corrective osteotomy was simulated with the help of three-dimensional bone surface models created using CT data. We simulated the most appropriate screw holes in the deformed radius using computer-aided design data of a locking plate. During surgery, using a custom-made surgical template, we predrilled the screw holes as simulated. After osteotomy, plate fixation using predrilled screw holes enabled automatic reduction of the distal radial fragment. Autogenous iliac cancellous bone was grafted after plate fixation. The median volar tilt, radial inclination, and ulnar variance improved from -20°, 13°, and 6 mm, respectively, before surgery to 12°, 24°, and 1 mm, respectively, after surgery. The median wrist flexion improved from 33° before surgery to 60° after surgery. The median wrist extension was 70° before surgery and 65° after surgery. All patients experienced wrist pain before surgery, which disappeared or decreased after surgery. Surgeons can operate precisely and easily using this advanced technique. It is a new treatment option for malunion of distal radius fractures.

Fracture heuristics: surgical decision for approaches to distal radius fractures. A surgeon's perspective.

PubMed

Wichlas, Florian; Tsitsilonis, Serafim; Kopf, Sebastian; Krapohl, Björn Dirk; Manegold, Sebastian

2017-01-01

Introduction: The aim of the present study is to develop a heuristic that could replace the surgeon's analysis for the decision on the operative approach of distal radius fractures based on simple fracture characteristics. Patients and methods: Five hundred distal radius fractures operated between 2011 and 2014 were analyzed for the surgeon's decision on the approach used. The 500 distal radius fractures were treated with open reduction and internal fixation through palmar, dorsal, and dorsopalmar approaches with 2.4 mm locking plates or underwent percutaneous fixation. The parameters that should replace the surgeon's analysis were the fractured palmar cortex, and the frontal and the sagittal split of the articular surface of the distal radius. Results: The palmar approach was used for 422 (84.4%) fractures, the dorsal approach for 39 (7.8%), and the combined dorsopalmar approach for 30 (6.0%). Nine (1.8%) fractures were treated percutaneously. The correlation between the fractured palmar cortex and the used palmar approach was moderate (r=0.464; p<0.0001). The correlation between the frontal split and the dorsal approach, including the dorsopalmar approach, was strong (r=0.715; p<0.0001). The sagittal split had only a weak correlation for the dorsal and dorsopalmar approach (r=0.300; p<0.0001). Discussion: The study shows that the surgical decision on the preferred approach is dictated through two simple factors, even in the case of complex fractures. Conclusion: When the palmar cortex is displaced in distal radius fractures, a palmar approach should be used. When there is a displaced frontal split of the articular surface, a dorsal approach should be used. When both are present, a dorsopalmar approach should be used. These two simple parameters could replace the surgeon's analysis for the surgical approach.

The biomechanical analysis of three-dimensional distal radius fracture model with different fixed splints.

PubMed

Hua, Zhen; Wang, Jian-Wei; Lu, Zhen-Fei; Ma, Jian-Wei; Yin, Heng

2018-01-01

The distal radius fracture is one of the common clinical fractures. At present, there are no reports regarding application of the finite element method in studying the mechanism of Colles fracture and the biomechanical behavior when using splint fixation. To explore the mechanism of Colles fracture and the biomechanical behavior when using different fixed splints. Based on the CT scanning images of forearm for a young female volunteer, by using model construction technology combined with RPOE and ANSYS software, a 3-D distal radius fracture forearm finite element model with a real shape and bioactive materials is built. The material tests are performed to obtain the mechanical properties of the paper-based splint, the willow splint and the anatomical splint. The numerical results are compared with the experimental results to verify the correctness of the presented model. Based on the verified model, the stress distribution of different tissues are analyzed. Finally, the clinical tests are performed to observe and verify that the anatomical splint is the best fit for human body. Using the three kinds of splints, the transferred bone stress focus on the distal radius and ulna, which is helpful to maintain the stability of fracture. Also the stress is accumulated in the distal radius which may be attributed to flexion position. Such stress distribution may be helpful to maintain the ulnar declination. By comparing the simulation results with the experimental observations, the anatomical splint has the best fitting to the limb, which can effectively avoid the local compression. The anatomical splint is the most effective for fixing and curing the fracture. The presented model can provide theoretical basis and technical guide for further investigating mechanism of distal radius fracture and clinical application of anatomical splint.

Reproducibility of three dimensional digital preoperative planning for the osteosynthesis of distal radius fractures.

PubMed

Yoshii, Yuichi; Kusakabe, Takuya; Akita, Kenichi; Tung, Wen Lin; Ishii, Tomoo

2017-12-01

A three-dimensional (3D) digital preoperative planning system for the osteosynthesis of distal radius fractures was developed for clinical practice. To assess the usefulness of the 3D planning for osteosynthesis, we evaluated the reproducibility of the reduction shapes and selected implants in the patients with distal radius fractures. Twenty wrists of 20 distal radius fracture patients who underwent osteosynthesis using volar locking plates were evaluated. The 3D preoperative planning was performed prior to each surgery. Four surgeons conducted the surgeries. The surgeons performed the reduction and the placement of the plate while comparing images between the preoperative plan and fluoroscopy. Preoperative planning and postoperative reductions were compared by measuring volar tilt and radial inclination of the 3D images. Intra-class correlation coefficients (ICCs) of the volar tilt and radial inclination were evaluated. For the implant choices, the ICCs for the screw lengths between the preoperative plan and the actual choices were evaluated. The ICCs were 0.644 (p < 0.01) and 0.625 (p < 0.01) for the volar tilt and radial inclination in the 3D measurements, respectively. The planned size of plate was used in all of the patients. The ICC for the screw length between preoperative planning and actual choice was 0.860 (p < 0.01). Good reproducibility for the reduction shape and excellent reproducibility for the implant choices were achieved using 3D preoperative planning for distal radius fracture. Three-dimensional digital planning was useful to visualize the reduction process and choose a proper implant for distal radius fractures. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2646-2651, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Incidence and Functional Outcomes of Scapholunate Diastases Associated Distal Radius Fractures: A 2-year Follow-Up Scapholunate Dissociation

PubMed Central

Lans, Jonathan; Lasa, Alejandro; Chen, Neal C.; Jupiter, Jesse B.

2018-01-01

Background: The Scapholunate Interosseous Ligament (SLIL) is the first intrinsic carpal ligament to be injured in wrist trauma, present in up to 64% of the distal radius fractures. However, it remains unclear what patients develop symptoms, making primary treatment of these injuries accompanying distal radius fractures remains questionable. Objective: The aim of this study was to evaluate the functional outcomes of patients with scapholunate diastasis associated with distal radius fractures. Methods: We evaluated 391 patients with a distal radius fracture. Using Computer Tomography (CT) scans the scapholunate interval was measured. We identified 14 patients with an SLD (>3mm) of the injured wrist, which underwent a CT-scan of the contralateral wrist. To evaluate the functional outcomes at a mean follow up of 136±90 weeks, we used the Quick Disabilities of the Arm, Shoulder and Hand (qDASH) Score. Results: There were 8 patients with bilateral SLD and 6 patients with unilateral SLD. Five patients had a qDASH score of 0 and one patient showed a qDASH score of 18.2. The patient with a poor score had bilateral preexisting osteoarthritis of the wrist. No patient had additional surgery of the SLIL. Conclusion: In patients with distal radius fractures, more than half of the 14 patients with an SL gap on CT had widening on the contralateral side. It is therefore worthwhile to image the contralateral wrist before diagnosing a SLD. The patients with unilateral SLD should not be surgically treated at initial presentation because they may have good functional outcomes after a follow up of 2 years. PMID:29456778

A Comprehensive Study of Internal Distraction Plating, an Alternative Method for Distal Radius Fractures.

PubMed

Jain, Mohit J; Mavani, Kinjal J

2016-12-01

The management of highly comminuted distal radius fractures still remains a major treatment challenge. Articular comminution and compromised bone quality are the culprits. One novel approach is the technique of Internal Distraction Plating which involves "bridging" the fracture with the use of a standard 3.5mm plate applied dorsally in distraction from the radius, proximal to the fracture, to the long finger metacarpal distally, bypassing the comminuted segment. The plate is removed once fracture union has been achieved. The present study was conducted with the aim to evaluate the role of internal dorsal distraction plating as an alternative method in the treatment of fracture distal radius in terms of special indications, technique and outcome. This study was a prospective longitudinal study on 20 patients (mean age 62 years) treated with internal distraction plating for comminuted distal radius fractures with specific indications. Regular follow-ups with standard radiographs and analysis were done upto 24 months. Functional outcome were assessed by DASH Score and the Gartland and Werley demerit score. At final follow-up, all fractures had united and X-rays showed mean palmar tilt of 7°, positive ulnar variance of 0.5mm, radial inclination of 18° and average loss of 2mm of radial height. Mean range of motion values for wrist flexion 46°, extension 50°, pronation 79° and supination 77° At final follow-up, the mean DASH score was 32. 85% patient had excellent to good result as per Gartland and Werley demerit score. This construct has yield satisfactory clinical and radiographic results with these very challenging injuries. The purpose of this study was to report the radiographic and the functional outcomes of treatment with this technique. External fixator and volar plating in communited distal end radius fractures are not always satisfactory in old age with osteoporotic bone because of complications associated with them. The current technique represents an alternative that provides union of the comminuted distal radius fracture with anatomical alignment, optimal range of motion and with minimal clinical disability.

SURGICAL TREATMENT OF DISTAL RADIUS FRACTURES WITH A VOLAR LOCKED PLATE: CORRELATION OF CLINICAL AND RADIOGRAPHIC RESULTS

PubMed Central

Xavier, Claudio Roberto Martins; Dal Molin, Danilo Canesin; dos Santos, Rafael Mota Marins; dos Santos, Roberto Della Torre; Neto, Julio Cezar Ferreira

2015-01-01

Objectives: To analyze and correlate the clinical and radiographic results from patients with distal radius fractures who underwent surgical treatment with a fixed-angle volar locked plate. Methods: Sixty-four patients with distal radius fractures were evaluated. They all underwent surgical treatment with a volar locked plate for the distal radius, with a minimum of six months of postoperative follow-up. They underwent a physical examination that measured range of motion and grip strength, answered the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and underwent radiographic examination. Results: In the physical examination on the patients, all the range-of-motion measurements were reduced. Grip strength measured in kgf was on average 85.8% of the strength on the unaffected side. The mean DASH score was 15.99. A significant relationship was found between lower DASH scores and losses of extension and grip strength. On the radiographs, the mean values in relation to the unfractured side were 84.0% for radial inclination, 85.4% for radial length and 86.8% for volar deviation of the radius. Loss of radial length was correlated with losses of extension and grip strength. PMID:27027046

Volar plating for distal radius fractures--do not trust the image intensifier when judging distal subchondral screw length.

PubMed

Park, Derek H; Goldie, Boyd S

2012-09-01

The use of the volar plate to treat distal radius fractures is increasing but despite the theoretical advantages of a volar approach there have been reports of extensor tendon ruptures due to prominent screw tips protruding past the dorsal cortex. The valley in the intermediate column between Lister tubercle and the sigmoid notch of the distal radius makes it difficult to rely on fluoroscopy to judge screw length. Our aim was to quantify the dimensions of this valley and to demonstrate the danger of relying on intraoperative image intensification fluoroscopy to determine lengths of distal screws. We measured the depth of this valley in the intermediate column of the distal radius in 33 patients with computed tomographic (9 patients) or magnetic resonance image (24 patients) scans of the wrist. There was a consistent valley in all images examined [average 1.8 mm (95% confidence interval, 1.6-2.0 mm)]. Thirty-nine percent of wrists had a valley depth of at least 2 mm. Standard lateral views or rotation of the forearm to obtain oblique views does not identify prominent screw tips; and whatever the rotation of the forearm, screw tips protruding beyond dorsal cortex may look as if it is within the bone when in fact it is out. When drilling we suggest noting the depth at which the drill bit just penetrates dorsal cortex and routinely downsize the distal screw length by 2 mm. We caution against relying on flourosocopy when judging the length of the distal subchondral screws.

Two-wave propagation in in vitro swine distal ulna

NASA Astrophysics Data System (ADS)

Mano, Isao; Horii, Kaoru; Matsukawa, Mami; Otani, Takahiko

2015-07-01

Ultrasonic transmitted waves were obtained in an in vitro swine distal ulna specimen, which mimics a human distal radius, that consists of interconnected cortical bone and cancellous bone. The transmitted waveforms appeared similar to the fast waves, slow waves, and overlapping fast and slow waves measured in the specimen after removing the surface cortical bone (only cancellous bone). In addition, the circumferential waves in the cortical bone and water did not affect the fast and slow waves. This suggests that the fast-and-slow-wave phenomenon can be observed in an in vivo human distal radius.

[Eponyms of distal radius fractures. Colles-Pouteau, Smith-Goyrand and Barton fractures and their importance in the trauma surgery patient sample].

PubMed

Ebert, B; Müller, J E

1993-10-01

Fractures at the distal end of the radius are quite common. So, these fractures are well known to represent consequences of industrial accidents leading to temporary unfitness for work, too. Eponym descriptions of fractures may mislead authors and readers as well if used in a non-uniform way in medical literature. Using the original articles of the first describing authors a clear distinction of eponyms concerning fractures near to the wrist joint is given. The authors of this feature report of the clinical experience in treatment and results of distal radius fractures in combination with aspects of expert opinions on these fractures.

Team physician #5. Salter-Harris type I fracture of the distal radius due to weightlifting.

PubMed

Weiss, A P; Sponseller, P D

1989-02-01

A Salter-Harris Type I distal radius fracture was sustained by a skeletally immature adolescent while performing a supine bench press during weight training. Closed reduction was accomplished without difficulty. Fractures in adolescence due to weightlifting are rare but illustrate the need for proper instruction and supervision.

Supination and Pronation Strength Deficits Persist at 2-4 Years after Treatment of Distal Radius Fractures.

PubMed

Ploegmakers, Joris; The, Bertram; Wang, Allan; Brutty, Mike; Ackland, Tim

2015-10-01

Forearm rotation is a key function in the upper extremity. Following distal radius fracture, residual disability may occur in tasks requiring forearm rotation. The objectives of this study are to define pronation and supination strength profiles tested through the range of forearm rotation in normal individuals, and to evaluate the rotational strength profiles and rotational strength deficits across the testing range in a cohort of patients treated for distal radius fracture associated with an ulnar styloid base fracture. In a normative cohort of 29 subjects the supination strength profile showed an increasing linear relationship from supination to pronation. Twelve subjects were evaluated 2-4 years after anatomical open reduction and volar plate fixation of a distal radius fracture. The injured wrist was consistently weaker (corrected for hand dominance) in both supination and pronation strength in all testing positions, with the greatest loss in 60 degrees supination. Mean supination strength loss across all testing positions was significantly correlated with worse PRWE scores, highlighting the importance of supination in wrist function.

Is Bone Grafting Necessary in the Treatment of Malunited Distal Radius Fractures?

PubMed Central

Disseldorp, Dominique J. G.; Poeze, Martijn; Hannemann, Pascal F. W.; Brink, Peter R. G.

2015-01-01

Background Open wedge osteotomy with bone grafting and plate fixation is the standard procedure for the correction of malunited distal radius fractures. Bone grafts are used to increase structural stability and to enhance new bone formation. However, bone grafts are also associated with donor site morbidity, delayed union at bone–graft interfaces, size mismatch between graft and osteotomy defect, and additional operation time. Purpose The goal of this study was to assess bone healing and secondary fracture displacement in the treatment of malunited distal radius fractures without the use of bone grafting. Methods Between January 1993 and December 2013, 132 corrective osteotomies and plate fixations without bone grafting were performed for malunited distal radius fractures. The minimum follow-up time was 12 months. Primary study outcomes were time to complete bone healing and secondary fracture displacement. Preoperative and postoperative radiographs during follow-up were compared with each other, as well as with radiographs of the uninjured side. Results All 132 osteotomies healed. In two cases (1.5%), healing took more than 4 months, but reinterventions were not necessary. No cases of secondary fracture displacement or hardware failure were observed. Significant improvements in all radiographic parameters were shown after corrective osteotomy and plate fixation. Conclusion This study shows that bone grafts are not required for bone healing and prevention of secondary fracture displacement after corrective osteotomy and plate fixation of malunited distal radius fractures. Level of evidence Therapeutic, level IV, case series with no comparison group PMID:26261748

The effect of search term on the quality and accuracy of online information regarding distal radius fractures.

PubMed

Dy, Christopher J; Taylor, Samuel A; Patel, Ronak M; Kitay, Alison; Roberts, Timothy R; Daluiski, Aaron

2012-09-01

Recent emphasis on shared decision making and patient-centered research has increased the importance of patient education and health literacy. The internet is rapidly growing as a source of self-education for patients. However, concern exists over the quality, accuracy, and readability of the information. Our objective was to determine whether the quality, accuracy, and readability of information online about distal radius fractures vary with the search term. This was a prospective evaluation of 3 search engines using 3 different search terms of varying sophistication ("distal radius fracture," "wrist fracture," and "broken wrist"). We evaluated 70 unique Web sites for quality, accuracy, and readability. We used comparative statistics to determine whether the search term affected the quality, accuracy, and readability of the Web sites found. Three orthopedic surgeons independently gauged quality and accuracy of information using a set of predetermined scoring criteria. We evaluated the readability of the Web site using the Fleisch-Kincaid score for reading grade level. There were significant differences in the quality, accuracy, and readability of information found, depending on the search term. We found higher quality and accuracy resulted from the search term "distal radius fracture," particularly compared with Web sites resulting from the term "broken wrist." The reading level was higher than recommended in 65 of the 70 Web sites and was significantly higher when searching with "distal radius fracture" than "wrist fracture" or "broken wrist." There was no correlation between Web site reading level and quality or accuracy. The readability of information about distal radius fractures in most Web sites was higher than the recommended reading level for the general public. The quality and accuracy of the information found significantly varied with the sophistication of the search term used. Physicians, professional societies, and search engines should consider efforts to improve internet access to high-quality information at an understandable level. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Conversion of external fixation to open reduction and internal fixation for complex distal radius fractures.

PubMed

Natoli, R M; Baer, M R; Bednar, M S

2016-05-01

Distal radius fractures are common injuries treated in a multitude of ways. One treatment paradigm not extensively studied is initial treatment by external fixation (EF) followed by conversion to open reduction internal fixation (ORIF). Such a paradigm may be beneficial in damage control situations, when there is extensive soft tissue injury, or when appropriate personnel/hospital resources are not available for immediate internal fixation. There is no increased risk of infection when converting EF to ORIF in the treatment of complex distal radius fractures when conversion occurs early or if EF pin sites are overlapped by the definitive fixation. Using an IRB approved protocol, medical records over nine years were queried to identify patients with distal radius fractures that had undergone initial EF and were later converted to ORIF. Charts were reviewed for demographic data, injury characteristics, operative details, time to conversion from EF to ORIF, assessment of whether the EF pin sites overlapped the definitive fixation, presence of infection after ORIF, complications, and occupational therapy measurements of range of motion and strength. In total, 16 patients were identified, only one of which developed an infection following conversion to ORIF. Fisher's exact testing showed that infection did not depend on open fracture, time to conversion of one week or less, presence of EF pin sites overlapping definitive fixation, fracture classification, high energy mechanism of injury, or concomitant injury to the DRUJ. Planned staged conversion from EF to ORIF for complex distal radius fractures does not appear to result in an increased rate of infection if conversion occurs early or if the EF pin sites are overlapped by definitive fixation. This treatment paradigm may be reasonable for treating complex distal radius fractures in damage control situations, when there is extensive soft tissue injury, or when appropriate personnel/hospital resources are not available for immediate internal fixation. IV, retrospective case series. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Clinical effects of internal fixation for ulnar styloid fractures associated with distal radius fractures: A matched case-control study.

PubMed

Sawada, Hideyoshi; Shinohara, Takaaki; Natsume, Tadahiro; Hirata, Hitoshi

2016-11-01

Ulnar styloid fractures are often associated with distal radius fractures. However, controversy exists regarding whether to treat ulnar styloid fractures. This study aimed to evaluate clinical effects of internal fixation for ulnar styloid fractures after distal radius fractures were treated with the volar locking plate system. We used prospectively collected data of distal radius fractures. 111 patients were enrolled in this study. A matched case-control study design was used. We selected patients who underwent fixation for ulnar styloid fractures (case group). Three control patients for each patient of the case group were matched on the basis of age, sex, and fracture type of distal radius fractures from among patients who did not undergo fixation for ulnar styloid fractures (control group). The case group included 16 patients (7 men, 9 women; mean age: 52.6 years; classification of ulnar styloid fractures: center, 3; base, 11; and proximal, 2). The control group included 48 patients (15 men, 33 women; mean age: 61.1 years; classification of ulnar styloid fractures: center, 10; base, 31; and proximal, 7). For radiographic examination, the volar tilt angle, radial inclination angle, and ulnar variance length were measured, and the union of ulnar styloid fractures was judged. For clinical examination, the range of motions, grip strength, Hand20 score, and Numeric Rating Scale score were evaluated. There was little correction loss for each radiological parameter of fracture reduction, and these parameters were not significantly different between the groups. The bone-healing rate of ulnar styloid fractures was significantly higher in the case group than in the control group, but the clinical results were not significantly different. We revealed that there was no need to fix ulnar styloid fractures when distal radius fractures were treated via open reduction and internal fixation with a volar locking plate system. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Age- and site-related bone mineral densities in Korean women with a distal radius fracture compared with the reference Korean female population.

PubMed

Lee, Joon Oh; Chung, Moon Sang; Baek, Goo Hyun; Oh, Joo Han; Lee, Young Ho; Gong, Hyun Sik

2010-09-01

To assess age- and site-related bone mineral density (BMD) values in Korean female patients with a distal radius fracture, and to compare them with those of the community-based general Korean female population. For this study, we recruited 54 consecutive Korean women, 50 to 79 years of age, with a distal radius fracture caused by minor trauma. We performed dual-energy x-ray absorptiometry scans at central sites: the lumbar spine, femoral neck, trochanter, and Ward's triangle, which is a triangular area within the femoral neck. Age- and site-related BMDs were assessed and compared with those of population-based reference data for Korean women. The overall prevalence (defined as meeting the osteoporosis criteria in at least one of the earlier-described measurement areas) of osteoporosis in patients with a distal radius fracture was 57%. The site-related prevalence was 54% at Ward's triangle, 43% at the lumbar spine, 32% at the femoral neck, and 26% at the trochanter, and these values were individually statistically significantly higher than those of the general Korean female population except for the lumbar spine. In patients 50 to 59 and 70 to 79 years of age, patients' mean BMD values at the hip were statistically significantly lower than those of the reference female population of corresponding age groups, but the hip BMD differences were not statistically significant in patients 60 to 69 years of age. There were no statistically significant BMD differences measured at the lumbar spine in any age group. Korean female patients with a distal radius fracture, 50 to 59 and 70 to 79 years of age, had lower BMDs at the hip than the reference Korean female population. However, no statistically significant BMD differences were found in those 60 to 69 years of age. Low BMD may have a greater impact on distal radius fracture in women younger than 60 years of age or over 70 years of age. Considering the young onset of bone loss, patients younger than 60 years of age with a distal radius fracture are a good target group for secondary prevention of osteoporosis. Copyright 2010 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Biomechanics of the Upper Extremity in Response to Dynamic Impact Loading Indicative of a Forward Fall: An Experimental and Numerical Investigation

NASA Astrophysics Data System (ADS)

Burkhart, Timothy A.

The distal radius is one of the most common fracture sites in humans, often resulting from a forward fall with more than 60 % of all fractures to the wrist requiring some form of surgical intervention. Although there is a general consensus regarding the risk factors for distal radius fractures resulting from forward falling, prevention of these injuries requires a more thorough understanding of the injury mechanisms. Therefore the overall purpose of this dissertation was to assess the response of the upper extremity to impact loading to improve the understanding of distal radius fracture mechanisms and the effectiveness of joint kinematic strategies for reducing the impact effects. Three main studies were conducted that utilized in vivo, in vitro and numerical techniques. In vitro impact testing of the distal radius revealed that fracture will occur at a mean (SD) resultant impact force and velocity of 2142.1(1228.7) N and 3.4 (0.7) m/s, respectively. Based on the failure data, multi-variate injury criteria models were produced, highlighting the dynamic and multidirectional nature of distal radius fractures The in vitro investigation was also used to develop and validate a finite element model of the distal radius. Dynamic impacts were simulated in LS-DYNARTM and the resulting z-axis force validation metrics (0.23--0.54) suggest that this is a valid model. A comparison of the experimental fracture patterns to those predicted numerically (i.e. von-Mises stress criteria) shows the finite element model is capable of accurately predicting bone failure. Finally, an in vivo fall simulation apparatus was designed and built that was found to reliably (Intraclass Correlation Coefficients > 0.6) apply multi-directional motion and upper extremity impacts indicative of forward falls. This study revealed that, to some extent, individuals are capable of selected an impact strategy that minimizes the significant injury variables that were outlined in the in vitro investigation, with very little instruction. The body of work presented here has the potential to be used to develop distal radius fracture prevention methods in an attempt to improve the health and well being of those individuals currently at the highest risk of sustaining these injuries.

Computer-assisted versus non-computer-assisted preoperative planning of corrective osteotomy for extra-articular distal radius malunions: a randomized controlled trial.

PubMed

Leong, Natalie L; Buijze, Geert A; Fu, Eric C; Stockmans, Filip; Jupiter, Jesse B

2010-12-14

Malunion is the most common complication of distal radius fracture. It has previously been demonstrated that there is a correlation between the quality of anatomical correction and overall wrist function. However, surgical correction can be difficult because of the often complex anatomy associated with this condition. Computer assisted surgical planning, combined with patient-specific surgical guides, has the potential to improve pre-operative understanding of patient anatomy as well as intra-operative accuracy. For patients with malunion of the distal radius fracture, this technology could significantly improve clinical outcomes that largely depend on the quality of restoration of normal anatomy. Therefore, the objective of this study is to compare patient outcomes after corrective osteotomy for distal radius malunion with and without preoperative computer-assisted planning and peri-operative patient-specific surgical guides. This study is a multi-center randomized controlled trial of conventional planning versus computer-assisted planning for surgical correction of distal radius malunion. Adult patients with extra-articular malunion of the distal radius will be invited to enroll in our study. After providing informed consent, subjects will be randomized to two groups: one group will receive corrective surgery with conventional preoperative planning, while the other will receive corrective surgery with computer-assisted pre-operative planning and peri-operative patient specific surgical guides. In the computer-assisted planning group, a CT scan of the affected forearm as well as the normal, contralateral forearm will be obtained. The images will be used to construct a 3D anatomical model of the defect and patient-specific surgical guides will be manufactured. Outcome will be measured by DASH and PRWE scores, grip strength, radiographic measurements, and patient satisfaction at 3, 6, and 12 months postoperatively. Computer-assisted surgical planning, combined with patient-specific surgical guides, is a powerful new technology that has the potential to improve the accuracy and consistency of orthopaedic surgery. To date, the role of this technology in upper extremity surgery has not been adequately investigated, and it is unclear whether its use provides any significant clinical benefit over traditional preoperative imaging protocols. Our study will represent the first randomized controlled trial investigating the use of computer assisted surgery in corrective osteotomy for distal radius malunions. NCT01193010.

Biomechanics of the Proximal Radius Following Drilling of the Bicipital Tuberosity to Mimic Cortical Button Distal Biceps Repair Technique.

PubMed

Oak, Nikhil R; Lien, John R; Brunfeldt, Alexander; Lawton, Jeffrey N

2018-05-01

A fracture through the proximal radius is a theoretical concern after cortical button distal biceps fixation in an active patient. The permanent, nonossified cortical defect and medullary tunnel is at risk during a fall eliciting rotational and compressive forces. We hypothesized that during simulated torsion and compression, in comparison with unaltered specimens, the cortical button distal biceps repair model would have decreased torsional and compressive strength and would fracture in the vicinity of the bicipital tuberosity bone tunnel. Sixteen fourth-generation composite radius Sawbones models were used in this controlled laboratory study. A bone tunnel was created through the bicipital tuberosity to mimic the exact bone tunnel, 8 mm near cortex and 3.2 mm far cortex, made for the BicepsButton distal biceps tendon repair. The radius was then prepared and mounted on either a torsional or compression testing device and compared with undrilled control specimens. Compression tests resulted in average failure loads of 9015.2 N in controls versus 8253.25 N in drilled specimens ( P = .074). Torsional testing resulted in an average failure torque of 27.3 Nm in controls and 19.3 Nm in drilled specimens ( P = .024). Average fracture angle was 35.1° in controls versus 21.1° in drilled. Gross fracture patterns were similar in compression testing; however, in torsional testing all fractures occurred through the bone tunnel in the drilled group. There are weaknesses in the vicinity of the bone tunnel in the proximal radius during biomechanical stress testing which may not be clinically relevant in nature. In cortical button fixation, distal biceps repairs creates a permanent, nonossified cortical defect with tendon interposed in the bone tunnel, which can alter the biomechanical properties of the proximal radius during compressive and torsional loading.

A prospective study on the effectiveness of cotton versus waterproof cast padding in maintaining the reduction of pediatric distal forearm fractures.

PubMed

Robert, Christopher E; Jiang, Jimmy J; Khoury, Joseph G

2011-03-01

Distal forearm fractures, one of the most common fractures seen in the pediatric population, are regularly treated by closed reduction and casting. Our study investigates the effectiveness of Gore-Tex-lined casting in maintaining the reduction of 100% displaced distal forearm fractures compared with traditional cotton-lined casts. We screened all patients from February 2007 to July 2009 who presented to Children's Hospital in Birmingham, AL with a distal radius fracture. Only patients with 100% displaced distal radius fractures were eligible to be assigned to either the cotton-lined or Gore-Tex-lined cast groups. Power analysis was performed to identify an adequate patient sample size. The mean maximum change between initial post-reduction x-rays and follow-up x-rays for anterior-posterior (AP) angulation, AP displacement, lateral angulation, and lateral displacement of the radius were calculated for both cotton and Gore-Tex groups. The rate of subsequent intervention and/or unacceptable results for each group was also analyzed. Seven hundred and twenty-two patients were treated with distal radius fractures at our hospital with 59 patients eligible for inclusion in our study. Thirty-six of our patients were treated with cotton-lined casts, and 23 patients were treated with Gore-Tex-lined cast. The mean maximum change in AP angulation, AP displacement, lateral angulation, and lateral displacement of the radius after initial reduction was 9.2 degrees, 6.9%, 13.9 degrees, and 13.6%, respectively, for the cotton-lined cast group and 7.7 degrees, 6.1%, 14.6 degrees, and 9.6%, respectively, for the Gore-Tex-lined cast group. There were no statistical differences between the means of the 4 measurements (P=0.33, 0.69, 0.73, and 0.10, respectively). There were also no significant differences between groups for final AP and lateral angulation and displacement. Subgroup analysis showed no significant differences in all measurements between cotton and Gore-Tex groups. Gore-Tex and cotton-lined casts are equally effective in their ability to maintain the reduction of 100% displaced distal forearm fractures. Thus, Gore-Tex-lined casts can be offered to pediatric patients immediately after closed reduction of distal radius fractures of any severity. Therapeutic level II.

[Osteosynthesis of distal radius fractures by doral plate: advantages and disadvantages].

PubMed

Obert, L; Vichard, P; Garbuio, P; Tropet, Y

2001-12-01

Distal radius fractures remain a challenge. No one osteosynthesis procedure can solve all the problems. A method of analysis is necessary in order to choose the best tools. Open treatment of the fracture is logical but rarely performed. A review of the literature and the experience of the authors are reported in order to analyse the correct place of dorsal plating in distal radius fracture with dorsal displacement. The learning curve of the operative procedure and the design of the implants can explain the occurrence of several complications. The dorsal plate is effective against secondary dorsal displacement. This demanding procedure must be compared with other reported procedures (pining and external fixator) to define the advantages and disadvantages.

[Free microvascular fibula graft for skeletal reconstruction of the distal radius: 5 years follow-up after en-bloc resection of a giant cell tumour].

PubMed

Franz, T; Krawczyk, T; Eggli, S; Wartburg, U von

2010-10-01

A giant cell tumour of the distal radius or of the carpal bones, verified by incisional biopsies, should be approached as a low-grade malignancy. Lesions that arise in the bones of the hand or the wrist have a greater propensity to metastasise, and have a higher risk of local recurrence. In this case report we describe a 54-year-old women with a giant cell tumour of the distal radius (Campanacci grade III lesion), having a follow-up of five years without signs of local recurrence or metastatic disease. The general principles of and options for surgical treatment are discussed. © Georg Thieme Verlag KG Stuttgart · New York.

Radiographic Outcomes of Dorsal Distraction Distal Radius Plating for Fractures With Dorsal Marginal Impaction.

PubMed

Huish, Eric G; Coury, John G; Ibrahim, Mohamed A; Trzeciak, Marc A

2017-04-01

The purpose of this study is to compare radiographic outcomes of patients treated with dorsal spanning plates with previously reported normal values of radiographic distal radius anatomy and compare the results with prior publications for both external fixation and internal fixation with volar locked plates. Patients with complex distal radius fractures including dorsal marginal impaction pattern necessitating dorsal distraction plating at the discretion of the senior authors (M.A.T. and M.A.I.) from May 30, 2013, to December 29, 2015, were identified and included in the study. Retrospective chart and radiograph review was performed on 19 patients, 11 male and 8 female, with mean age of 47.83 years (22-82). No patients were excluded from the study. All fractures united prior to plate removal. The average time the plate was in place was 80.5 days (49-129). Follow-up radiographs showed average radial inclination of 20.5° (13.2°-25.5°), radial height of 10.7 mm (7.5-14 mm), ulnar variance of -0.3 mm (-2.1 to 3.1 mm), and volar tilt of 7.9° (-3° to 15°). One patient had intra-articular step-off greater than 2 mm. Dorsal distraction plating of complex distal radius fractures yields good radiographic results with minimal complications. In cases of complex distal radius fractures including dorsal marginal impaction where volar plating is not considered adequate, a dorsal distraction plate should be considered as an alternative to external fixation due to reduced risk for infection and better control of volar tilt.

Antero-medial approach to the wrist: anatomic basis and new application in cases of fracture of the lunate facet.

PubMed

Uzel, A-P; Bulla, A; Laurent-Joye, M; Caix, P

2011-08-01

The Henry approach is the classical anterolateral surgical exposure of the volar aspect of the distal radius. This approach does not allow good access to the medial side of the volar distal radius (lunate facet) and the distal radio-ulnar joint, unless it is extended proximally, retracting the tendons and the median nerve medially, which can cause some trauma. The purpose of our study was to investigate the anatomic basis and to outline the advantages of the unusual anteromedial approach, reporting our experience in the treatment of 4 distal radius fractures, with a 90° or 180° twist of the lunate facet, and 10 wrist dissections on cadavers. The average follow-up was 68.8 months (range 18 to 115 months). In our series, this approach did not cause any nerve injuries or any sensory loss of the distal forearm and the palm. All the fractures of the lunate facet and of the radial styloid process healed. One patient with an ulnar styloid process fracture associated showed pseudarthrosis, but with no instability of the distal radio-ulnar joint or pain on the ulnar side. Using the criteria of Green and O'Brien, modified by Cooney, the results were: excellent in two cases, good in one case, and average in another. The evaluation of arthritis according to Knirk and Jupiter's classification showed grade 0 in three cases and grade 3 in one case with osteochondral sclerosis. We showed that the anteromedial approach is reliable and convenient in the case of fractures situated in the antero-medial portion of the radius, for the double objective of reducing the fracture under direct control and checking the congruence of the distal radio-ulnar joint.

Vascularized bone graft for scaphoid nonunions.

PubMed

Mih, Alexander D

2004-09-01

Scaphoid fracture nonunion remains a challenging problem that may persist despite traditional methods of bone grafting and internal fixation. The alteration of wrist mechanics created by nonunion as well as the development of avascular necrosis leads to degenerative change of the radiocarpal joint accompanied by loss of motion and pain. The use of a vascularized bone graft has the theoretical benefit of increased blood flow that exceeds that of nonvascularized grafts. Numerous sources of vascularized bone graft have been described, including those from remote sites as well as from the carpus and distal radius. Knowledge of the blood supply to the distal radius has allowed for development of several vascularized bone graft harvest sites. The results of vascularized bone grafting from the distal radius have been encouraging, with numerous authors reporting the successful treatment of scaphoid nonunions.

[Outcomes of minimally invasive plate osteosynthesis (MIPO) with volar locking plates in distal radius fractures: A review].

PubMed

Liverneaux, P; Ichihara, S; Facca, S; Hidalgo Diaz, J J

2016-12-01

Minimally invasive plate osteosynthesis (MIPO) has been used in recent years to treat fractures of the distal radius with volar locking plates. Its advantages are the preservation of the pronator quadratus and good esthetics. The MIPO technique was described originally with two incisions: one distal transverse or longitudinal incision and one proximal longitudinal incision. The trend is now to use a single longitudinal incision less than 20mm long. Functional and radiological outcomes are comparable to those of conventional techniques. The MIPO technique is indicated for extra-articular and intra-articular fractures. Arthroscopy may be used concurrently in the latter case. When the distal radius fracture is associated with a proximal shaft fracture, a double incision is needed to introduce a longer plate. The relative contraindications of the MIPO technique are comminuted intra-articular fractures in osteoporotic elderly patients. If reduction is problematic, a larger incision can easily be made. Copyright © 2016 SFCM. Published by Elsevier Masson SAS. All rights reserved.

Radiographic signs of static carpal instability with distal end radius fractures: is current treatment adequate?

PubMed

Bunker, D L J; Pappas, G; Moradi, P; Dowd, M B

2012-01-01

Patients presenting with distal end radius fractures may have concomitant carpal instability due to disruption of the scapholunate ligament. This study examined the incidence of static radiographic signs of carpal instability in patients with distal radial fractures before and after fracture treatment. We performed a retrospective radiographic study of 141 patients presenting to Central Middlesex Hospital, London between January 2002-May 2004 with distal end radius fractures. We used abnormal scapholunate angle as the primary indicator of possible carpal dissociation. Abnormal scapholunate angles were noted in 39% of patients at presentation and 35% of patients after treatment with no statistically significant intra-patient variability. Persistent static radiographic signs of carpal instability are high in this subset of patients. The long-term morbidity of persistent wrist instability may be avoided by early radiological diagnosis with clinical correlation to identify carpal ligament injuries and initiate treatment that addresses both the bony and ligamentous components of the injury.

[Distal clavicle fracture].

PubMed

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

2014-06-01

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

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

PubMed

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

2016-06-01

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

Prevention of recurrent radioulnar heterotopic ossification by combined indomethacin and a dermal/silicone sheet implant: case report.

PubMed

Lytle, Ian F; Chung, Kevin C

2009-01-01

A 27-year-old, right-handed man developed severe radioulnar synostosis at the distal radius 7 months after open reduction and internal fixation of his distal radius fracture. Heterotopic ossification formed at the radius fracture site, requiring excision of the heterotopic bone and plate removal. A bilayer, dermal substitute and silicone sheet was placed between the radius and ulna in the interosseous space to prevent recurrence of the heterotopic ossification. After surgery, the patient was treated with indomethacin 25 mg orally 3 times daily for 6 weeks. At 1 year after surgery, he has retained full pronation and near normal supination. Radiographs demonstrate no new heterotopic bone formation.

Citation analysis of the 100 most common articles regarding distal radius fractures.

PubMed

Jones, Richard; Hughes, Travis; Lawson, Kevin; DeSilva, Gregory

2017-01-01

Bibliometric studies are increasingly being utilized as a tool for gauging the impact of different literature within a given field. The purpose of this study was to identify the most cited articles related to the management of distal radius fractures to better understand how the evidence of this topic has been shaped and changed over time. We utilized the ISI web of science database to conduct a search for the term "distal radius fracture" under the "orthopaedics" research area heading, and sorted the results by number of times cited. The 100 most cited articles published in orthopedic journals were then analyzed for number of citations, source journal, year of publication, number of authors, study type, level of evidence, and clinical outcomes utilized. The 100 most cited articles identified were published between 1951 and 2009. Total number of citations ranged between 525 and 67, and came from ten different orthopedic journals. The largest number of articles came from J Hand Surg Am and J Bone Joint Surg Am, each with 32. Consistent with previous analyses of orthopedic literature, the articles were primarily clinical, and of these, 53/76 were case series. The vast majority were evidence level IV. Only a small percentage of articles utilized patient reported outcome measures. These data show that despite distal radius fractures being a common fracture encountered by physicians, very few of the articles were high quality studies, and only a low proportion of the studies include patient reported outcome measures. Surgeons should take this lack of high-level evidence into consideration when referencing classic papers in this field. Analysis of the 100 most cited distal radius fracture articles allows for delineation of which articles are most common in the field and if a higher level of evidence correlates positively with citation quantity.

Distal Radius Fractures Do Not Displace following Splint or Cast Removal in the Acute, Postreduction Period: A Prospective, Observational Study.

PubMed

Foster, Brock D; Sivasundaram, Lakshmanan; Heckmann, Nathanael; Pannell, William C; Alluri, Ram K; Ghiassi, Alidad

2017-02-01

Background  Displacement of distal radius fractures has been previously described in the literature; however, little is known about fracture displacement following splint or cast removal at the initial clinic visit following reduction and immobilization. Purpose  The purpose of this study was to evaluate risk factors for fracture displacement following splint or cast removal and physical examination in the acute postinjury period. Methods  All patients with a closed distal radius fracture who presented to our orthopedic hand clinic within 3 weeks of injury were prospectively enrolled in our study. Standard wrist radiographs were obtained prior to splint or cast removal. A second wrist series was obtained following physical exam and application of immobilization at the end of the clinic visit. Radiographic parameters for displacement were measured by two independent reviewers and included dorsal angulation, radial inclination, articular step-off, radial height, and ulnar variance. Displacement was assessed using predefined, radiographic criteria for displacement. Results  A total of 64 consecutive patients were enrolled over a period of 12 weeks. Of these, 37.5% were classified as operative according to American Academy of Orthopaedic Surgeons guidelines and 37.5% met LaFontaine instability criteria. For each fracture, none of the five measurements exceeded the predefined clinically or statistically significant criteria for displacement. Conclusion  Splint removal in the acute postinjury period did not result in distal radius fracture displacement. Clinicians should feel comfortable removing splints and examining underlying soft tissue in the acute setting for patients with distal radius fractures after closed reduction. Level of Evidence  Level II, prospective comparative study.

Effects of Ibuprofen and Resistance Training on Bone and Muscle: A Randomized Controlled Trial in Older Women.

PubMed

Duff, Whitney R D; Chilibeck, Philip D; Candow, Darren G; Gordon, Julianne J; Mason, Riley S; Taylor-Gjevre, Regina; Nair, Bindu; Szafron, Michael; Baxter-Jones, Adam; Zello, Gordon A; Kontulainen, Saija A

2017-04-01

Resistance training with ibuprofen supplementation may improve musculoskeletal health in postmenopausal women. The study purpose was to determine the efficacy of resistance training and ibuprofen supplementation on bone and muscle properties in postmenopausal women. Participants (n = 90, 65.3 ± 4.9 yr) were randomly assigned to: supervised resistance training or stretching (placebo-exercise) with postexercise ibuprofen (400 mg) or placebo supplementation for 3 d·wk (9 months). Baseline and postintervention measurements included distal and shaft scans of the forearm and lower leg using peripheral quantitative computed tomography. Distal site outcomes included cross-sectional area, content, and density for total and trabecular bone, as well as estimated bone strength in compression. Shaft site outcomes included total bone area; cortical bone area, content, and density; estimated bone strength in torsion; and muscle area and density. Exercise-supplement-time interactions for total bone content at the distal radius (P = 0.009) and cortical density at the radius shaft (P = 0.038) were significant. Resistance training with ibuprofen decreased total bone content (-1.5%) at the distal radius in comparison to the resistance training (0.6%; P = 0.032) and ibuprofen alone (0.5%; P = 0.050). Change in cortical density at the radius shaft differed between the stretching with placebo and ibuprofen supplementation groups (-1.8% vs 1.1%; P = 0.050). Resistance training preserved muscle density in the lower leg more so than stretching (-3.1% vs -5.4%; P = 0.015). Ibuprofen consumed immediately after resistance training had a deleterious effect on bone mineral content at the distal radius, whereas resistance training or ibuprofen supplementation individually prevented bone loss. Resistance training prevented muscle density decline in the lower leg.

Outcomes and complications of fractures of distal radius (AO type B and C): volar plating versus nonoperative treatment.

PubMed

Sharma, Himanshu; Khare, Ghanshyam Narayan; Singh, Saurabh; Ramaswamy, Arun Govindraj; Kumaraswamy, Vinay; Singh, Ashutosh Kumar

2014-07-01

Management of AO type B and C fractures of the distal radius is controversial. This study compares outcomes and complications of AO type B and C fractures of the distal radius treated with volar locked plating and nonoperative methods. Sixty-four patients with fractures of the distal radius (AO type B and C) were included in this study, according to inclusion criteria, and were allocated to the volar plating group or nonoperative group by alternate randomization: 32 patients with odd numbers went into the nonoperative group and the other 32 with even numbers went into the volar plating group. Patients in the nonoperative group were managed with closed reduction of the fracture and plaster cast application under an image intensifier. Those in the volar plating group were managed by open reduction and fixation with a volar locked plate. Preoperative and postoperative serial clinico-radiological follow-up was done. The range of movement, grip strength, functional outcome scores and radiological parameters were compared. Student's t-test was used for statistical analysis with significance at p < 0.05. Range of movement and functional scores were significantly (p < 0.001) better in the volar plating group, but the difference in ulnar variance and radial and ulnar deviation was insignificant as compared to the nonoperative group. At 24 months follow-up, the nonoperative group had significantly more cases with malunion, articular incongruity and osteoarthritis. In cases of AO type B or C fractures of the distal radius, volar locked plating provides anatomical stable fixation and early mobilization with better clinico-radiological outcome as compared to conservative treatment.

Mid-term functional outcome after the internal fixation of distal radius fractures

PubMed Central

2012-01-01

Background Distal radius fracture is a common injury with a variety of operative and non-operative management options. There remains debate as to the optimal treatment for a given patient and fracture. Despite the popularity of volar locking plate fixation, there are few large cohort or long term follow up studies to justify this modality. Our aim was to report the functional outcome of a large number of patients at a significant follow up time after fixation of their distal radius with a volar locking plate. Methods 180 patients with 183 fractures and a mean age of 62.4 years were followed up retrospectively at a mean of 30 months (Standard deviation = 10.4). Functional assessment was performed using the Disabilities of the Arm, Shoulder and Hand (DASH) and modified MAYO wrist scores. Statistical analysis was performed to identify possible variables affecting outcome and radiographs were assessed to determine time to fracture union. Results The median DASH score was 2.3 and median MAYO score was 90 for the whole group. Overall, 133 patients (74%) had a good or excellent DASH and MAYO score. Statistical analysis showed that no specific variable including gender, age, fracture type, post-operative immobilisation or surgeon grade significantly affected outcome. Complications occurred in 27 patients (15%) and in 11 patients were major (6%). Conclusion This single centre large population series demonstrates good to excellent results in the majority of patients after volar locking plate fixation of the distal radius, with complication rates comparable to other non-operative and operative treatment modalities. On this basis we recommend this mode of fixation for distal radius fractures requiting operative intervention. PMID:22280557

Mid-term functional outcome after the internal fixation of distal radius fractures.

PubMed

Phadnis, Joideep; Trompeter, Alex; Gallagher, Kieran; Bradshaw, Lucy; Elliott, David S; Newman, Kevin J

2012-01-26

Distal radius fracture is a common injury with a variety of operative and non-operative management options. There remains debate as to the optimal treatment for a given patient and fracture. Despite the popularity of volar locking plate fixation, there are few large cohort or long term follow up studies to justify this modality. Our aim was to report the functional outcome of a large number of patients at a significant follow up time after fixation of their distal radius with a volar locking plate. 180 patients with 183 fractures and a mean age of 62.4 years were followed up retrospectively at a mean of 30 months (Standard deviation=10.4). Functional assessment was performed using the Disabilities of the Arm, Shoulder and Hand (DASH) and modified MAYO wrist scores. Statistical analysis was performed to identify possible variables affecting outcome and radiographs were assessed to determine time to fracture union. The median DASH score was 2.3 and median MAYO score was 90 for the whole group. Overall, 133 patients (74%) had a good or excellent DASH and MAYO score. Statistical analysis showed that no specific variable including gender, age, fracture type, post-operative immobilisation or surgeon grade significantly affected outcome. Complications occurred in 27 patients (15%) and in 11 patients were major (6%). This single centre large population series demonstrates good to excellent results in the majority of patients after volar locking plate fixation of the distal radius, with complication rates comparable to other non-operative and operative treatment modalities. On this basis we recommend this mode of fixation for distal radius fractures requiting operative intervention.

Relationship between distal radius fracture malunion and arm-related disability: A prospective population-based cohort study with 1-year follow-up

PubMed Central

2011-01-01

Background Distal radius fracture is a common injury and may result in substantial dysfunction and pain. The purpose was to investigate the relationship between distal radius fracture malunion and arm-related disability. Methods The prospective population-based cohort study included 143 consecutive patients above 18 years with an acute distal radius fracture treated with closed reduction and either cast (55 patients) or external and/or percutaneous pin fixation (88 patients). The patients were evaluated with the disabilities of the arm, shoulder and hand (DASH) questionnaire at baseline (concerning disabilities before fracture) and one year after fracture. The 1-year follow-up included the SF-12 health status questionnaire and clinical and radiographic examinations. Patients were classified into three hypothesized severity categories based on fracture malunion; no malunion, malunion involving either dorsal tilt (>10 degrees) or ulnar variance (≥1 mm), and combined malunion involving both dorsal tilt and ulnar variance. Multivariate regression analyses were performed to determine the relationship between the 1-year DASH score and malunion and the relative risk (RR) of obtaining DASH score ≥15 and the number needed to harm (NNH) were calculated. Results The mean DASH score at one year after fracture was significantly higher by a minimum of 10 points with each malunion severity category. The RR for persistent disability was 2.5 if the fracture healed with malunion involving either dorsal tilt or ulnar variance and 3.7 if the fracture healed with combined malunion. The NNH was 2.5 (95% CI 1.8-5.4). Malunion had a statistically significant relationship with worse SF-12 score (physical health) and grip strength. Conclusion Malunion after distal radius fracture was associated with higher arm-related disability regardless of age. PMID:21232088

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

[Distal radius fractures--retrospective quality control after conservative and operative therapy].

PubMed

Sommer, C; Brendebach, L; Meier, R; Leutenegger, A

2001-01-01

The distal radius fracture is the most frequent fracture in the adult patient. The wide spectrum of different types of fracture and the coexisting factors make the choice for the optimal treatment difficult. As an interne quality control we retrospectively evaluated all patients with distal radius fractures treated in 1995 at our institution. The study included 69 adult patients with 71 distal radius fractures. After on average 26 months 58 patients with 59 fractures were clinically and radiologically evaluated. The patients were asked to give supplementary information about their follow-up treatment as well as any remaining physical difficulties and limitations in the daily life. All x-rays of the broken radius were carefully analysed and compared with the opposite side. The final results were evaluated according to the "Demerit Point System". Patients were treated with five different therapeutical methods. 76.3% of the patients showed a very good/good final result. In 56.7% of the cases secondary fracture dislocation occurred; the dislocation-rate of fractures treated with percutaneous k-wires was 93.3%! A clear correlation between secondary displacement and final results was found. A main factor for an optimal outcome is the anatomic restoration of length and axis of the distal radius as well as of joint congruency, also moderate angular deformities are well tolerated. Our collective showed an unexpected high rate of secondary displacement, especially in the k-wire group. The reasons for this unsatisfactory event are manifold: too optimistic indication, insufficient follow-up examination in the first four to six weeks, inconsequent change to a more stable fixation method in case of a secondary dislocation. The results of this retrospective evaluation had a major impact on our concept of treatment. The dorso-radial double-plate technique combined with bone graft will be more used in the future especially in younger patients. The new standardised concept is the base of a present prospective study.

Age-related differences in volumetric bone mineral density, microarchitecture, and bone strength of distal radius and tibia in Chinese women: a high-resolution pQCT reference database study.

PubMed

Hung, V W Y; Zhu, T Y; Cheung, W-H; Fong, T-N; Yu, F W P; Hung, L-K; Leung, K-S; Cheng, J C Y; Lam, T-P; Qin, L

2015-06-01

In a cohort of 393 Chinese women, by using high-resolution peripheral quantitative computed tomography (HR-pQCT), we found that significant cortical bone loss occurred after midlife. Prominent increase in cortical porosity began at the fifth decade but reached a plateau before the sixth decade. Trabecular bone loss was already evident in young adulthood and continued throughout life. This study aimed to investigate age-related differences in volumetric bone mineral density (vBMD), microarchitecture, and estimated bone strength at peripheral skeleton in Chinese female population. In a cross-sectional cohort of 393 Chinese women aged 20-90 years, we obtained vBMD, microarchtecture, and micro-finite element-derived bone strength at distal radius and tibia using HR-pQCT. The largest predictive age-related difference was found for cortical porosity (Ct.Po) which showed over four-fold and two-fold differences at distal radius and tibia, respectively, over the adulthood. At both sites, cortical bone area, vBMD, and thickness showed significant quadratic association with age with significant decrease beginning after midlife. Change of Ct.Po became more prominent between age of 50 and 57 (0.26 %/year at distal radius, 0.54 %/year at distal tibia, both p ≤ 0.001) but thereafter, reached a plateau (0.015 and 0.028 %/year, both p > 0.05). In contrast, trabecular vBMD and microarchitecture showed linear association with age with significant deterioration observed throughout adulthood. Estimated age of peak was around age of 20 for trabecular vBMD and microarchitecture and Ct.Po and age of 40 for cortical vBMD and microarchitecture. Estimated stiffness and failure load peaked at mid-30s at the distal radius and at age 20 at distal tibia. Age-related differences in vBMD and microarchitecture in Chinese women differed by bone compartments. Significant cortical bone loss occurred after midlife. Prominent increase in Ct.Po began at the fifth decade but appeared to be arrested before the sixth decade. Loss of trabecular bone was already evident in young adulthood and continued throughout life.

Patient-specific distal radius locking plate for fixation and accurate 3D positioning in corrective osteotomy.

PubMed

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

2014-11-01

Preoperative three-dimensional planning methods have been described extensively. However, transferring the virtual plan to the patient is often challenging. In this report, we describe the management of a severely malunited distal radius fracture using a patient-specific plate for accurate spatial positioning and fixation. Twenty months postoperatively the patient shows almost painless reconstruction and a nearly normal range of motion.

Statistical analysis on the concordance of the radiological evaluation of fractures of the distal radius subjected to traction☆

PubMed Central

Machado, Daniel Gonçalves; da Cruz Cerqueira, Sergio Auto; de Lima, Alexandre Fernandes; de Mathias, Marcelo Bezerra; Aramburu, José Paulo Gabbi; Rodarte, Rodrigo Ribeiro Pinho

2016-01-01

Objective The objective of this study was to evaluate the current classifications for fractures of the distal extremity of the radius, since the classifications made using traditional radiographs in anteroposterior and lateral views have been questioned regarding their reproducibility. In the literature, it has been suggested that other options are needed, such as use of preoperative radiographs on fractures of the distal radius subjected to traction, with stratification by the evaluators. The aim was to demonstrate which classification systems present better statistical reliability. Results In the Universal classification, the results from the third-year resident group (R3) and from the group of more experienced evaluators (Staff) presented excellent correlation, with a statistically significant p-value (p < 0.05). Neither of the groups presented a statistically significant result through the Frykman classification. In the AO classification, there were high correlations in the R3 and Staff groups (respectively 0.950 and 0.800), with p-values lower than 0.05 (respectively <0.001 and 0.003). Conclusion It can be concluded that radiographs performed under traction showed good concordance in the Staff group and in the R3 group, and that this is a good tactic for radiographic evaluations of fractures of the distal extremity of the radius. PMID:26962498

Trigonometry-Integrated 'Lift' Technique (TILT) for Restoring Volar Tilt in Distal Radius Fractures: Description of Technique and Preliminary Results.

PubMed

Sechachalam, Sreedharan; Satku, Mala; Wong, Jian Hao Kevin; Tan, Lester Teong Jin; Yong, Fok Chuan

2017-03-01

Restoration of extra-articular and intra-articular parameters are important considerations during operative fixation of distal radius fractures. Restoration of volar tilt by using visual estimation and the 'lift' technique has previously been described. The aim of our study was to describe a mathematical technique for accurately restoring the volar tilt of the distal radius to acceptable anatomic values. A retrospective review of cases performed using the trigonometry-integrated ' lift' technique (TILT) was performed. This technique uses the pre-operative volar tilt angle as well as the dimensions of the implant to calculate the 'lift' required to restore volar tilt. Intra-operative angles were measured using a marked transparency overlay on fluoroscopic images. Pre-operative and post-operative volar tilt were measured and analysed. Twenty-seven fractures were included in the study, with 20 being classified as Arbeitsgemeinschaft für Osteosynthesefragen (AO) C-type. Pre-'lift' volar tilt ranged from 0° to -20°. Post-'lift' volar tilt ranged from 2° to 16°, with all but three cases ranging from 5° to 15°. The mean volar tilt achieved was 10.2°. The trigonometry-integrated 'lift' technique resulted in reliable intra-operative restoration of anatomic volar tilt in distal radius fractures.

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

PubMed

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

2015-02-01

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

A Systematic Review of Outcomes and Complications of Treating Unstable Distal Radius Fractures in the Elderly

PubMed Central

Diaz-Garcia, Rafael J.; Oda, Takashi; Shauver, Melissa J.; Chung, Kevin C.

2011-01-01

Purpose As the population in developed countries continues to age, the incidence of osteoporotic distal radius fractures (DRFs) will increase as well. Treatment of DRF in the elderly population is controversial. We systematically reviewed the existing literature for the management of DRFs in patients 60 and over with five common techniques: volar locking plate system (VLPS), non-bridging external fixation (non-BrEF), bridging external fixation (BrEF), percutaneous Kirschner-wire fixation (PKF), and cast immobilization (CI). Methods Articles retrieved from MEDLINE, Embase and CINAHL Plus that met predetermined inclusion and exclusion criteria were reviewed in two literature reviews. Outcomes of interest included wrist arc of motion, grip strength, functional outcome measurements, radiographic parameters, and the number and type of complications. The data were statistically analyzed using weighted means and proportions based on the sample size in each study. Results 2,039 papers were identified, and 21 papers fitting the inclusion criteria were selected in the primary review of articles with mean patient age of 60 and over. Statistically significant differences were detected for wrist arc of motion, grip strength, and DASH score, although these findings may not be clinically meaningful. Volar tilt and ulnar variance revealed significant differences amongst the groups, with CI resulting in the worst radiographic outcomes. The complications were significantly different, with CI having the lowest rate of complications, whereas VLPS had significantly more major complications requiring additional surgical intervention. Conclusions This systematic review suggests that despite worse radiographic outcomes associated with CI, functional outcomes were no different than surgically treated groups for patients 60 and over. Prospective comparative outcomes studies are necessary to evaluate the rate of functional recovery, cost, and outcomes associated with these 5 treatment methods. Level of Evidence Therapeutic, Level III PMID:21527140

Measurement of Malrotation on Direct Radiography in Pediatric Distal Radius Fractures

PubMed Central

Duymus, Tahir Mutlu; Mutlu, Serhat; Komur, Baran; Mutlu, Harun; Yucel, Bulent; Parmaksizoglu, Atilla Sancar

2016-01-01

Abstract The aim of this prospective study was to test a mathematical method of measuring the malrotation of pediatric distal radius fractures (PDRFs) from direct radiographs. A total of 70 pediatric patients who presented at the Emergency Department with a distal radius fracture were evaluated. For 38 selected patients conservative treatment for PDRF was planned. Anteroposterior and lateral radiographs were taken of all of the patients for comparison before and after reduction. Radius bone diameters were measured in the coronal and sagittal planes on the healthy and fractured sides. Using the diameter values on the healthy side and the new diameter values on the fractured side in the rotation formula, the degree of malrotation between the fracture ends was calculated. The mean follow-up period was 13.5 months. Patients’ mean age was 10.00 ± 3.19 years (range, 4–12 years). The rotation degree in the sagittal plane significantly differed between the proximal (26.52°±2.84°) and distal fracture ends (20.96°±2.73°) (P = 0.001). The rotation degree in the coronal plane significantly differed between the proximal (26.70°±2.38°) and distal fracture ends (20.26°±2.86°) (P = 0.001). The net rotation deformity of the fracture line was determined to be 5.55°± 3.54° on lateral radiographs and 5.44°± 3.35° on anteroposterior radiographs, no significant difference was observed between measurements (P >0.05). The malrotation deformity in PDRF occurs with greater rotation in the proximal fragment than in the distal fragment. The net rotation deformity created between the fracture ends can be calculated on direct radiographs. Level of Evidence: Diagnostic, Level II PMID:27149480

Open reduction and cranial bone plate fixation of fractures involving the distal aspect of the radius and ulna in miniature- and toy-breed dogs: 102 cases (2008-2015).

PubMed

De Arburn Parent, Rebecca; Benamou, Jérôme; Gatineau, Matthieu; Clerfond, Pierre; Planté, Jérôme

2017-06-15

OBJECTIVE To determine outcomes and complication rates of open reduction and cranial bone plate fixation of fractures involving the distal aspect of the radius and ulna in miniature- and toy-breed dogs. DESIGN Retrospective case series. ANIMALS 102 miniature- and toy-breed dogs (105 fractures) weighing ≤ 7 kg (15.4 lb) that had undergone open reduction and cranial bone plate fixation of a fracture involving the distal aspect of the radius and ulna from 2008 through 2015. PROCEDURES Medical records were reviewed and information extracted regarding dog and fracture characteristics, surgical variables, and follow-up examination data (including postoperative complications). Postoperative radiographs were examined for distal fragment size, implant placement, apposition, alignment, and healing stage. A long-term follow-up questionnaire was completed by telephone interview with dog owners at least 6 months after surgery. RESULTS Mean length of the distal bone fragment in all fractures was 19.2 mm, with a mean distal-to-total radial length ratio of 0.21. At last follow-up examination (typically 6 weeks after surgery), 97 (95%) dogs had no signs of lameness; minor lameness was identified in 5 (5%) dogs. Complications developed in 26 (25%) fractures (23 [22%] minor and 3 [3%] major complications). Sixty-eight of 71 (96%) owners rated the overall and long-term outcome as excellent and 3 (4%) as good; 68 of 71 (96%) dogs reportedly had no signs of residual lameness. CONCLUSIONS AND CLINICAL RELEVANCE Open reduction and cranial bone plate fixation for the treatment of radius-ulna fractures in miniature- and toy-breed dogs provided an excellent outcome with a low complication rate.

Distal Oblique Bundle Reinforcement for Treatment of DRUJ Instability.

PubMed

Brink, Peter R G; Hannemann, Pascal F W

2015-08-01

Background Chronic, dynamic bidirectional instability in the distal radioulnar joint (DRUJ) is diagnosed clinically, based on the patient's complaints and the finding of abnormal laxity in the vicinity of the distal ulna. In cases where malunion is ruled out or treated and there are no signs of osteoarthritis, stabilization of the DRUJ may offer relief. To this end, several different techniques have been investigated over the past 90 years. Materials and Methods In this article we outline the procedure for a new technique using a tendon graft to reinforce the distal edge of the interosseous membrane. Description of Technique A percutaneous technique is used to harvest the palmaris longus tendon and to create a tunnel, just proximal to the sigmoid notch, through the ulna and radius in an oblique direction. By overdrilling the radial cortex, the knotted tendon can be pulled through the radius and ulna and the knot blocked at the second radial cortex, creating a strong connection between the radius and ulna at the site of the distal oblique bundle (DOB). The tendon is fixed in the ulna with a small interference screw in full supination, preventing subluxation of the ulna out of the sigmoid notch during rotation. Results Fourteen patients were treated with this novel technique between 2011 and October 2013. The QuickDASH score at 25 months postoperatively (range 16-38 months) showed an improvement of 32 points. Similarly, an improvement of 33 points (67-34 months) was found on the PRWHE. Only one recurrence of chronic, dynamic bidirectional instability in the DRUJ was observed. Conclusion This simple percutaneous tenodesis technique between radius and ulna at the position of the distal edge of the interosseous membrane shows promise in terms of both restoring stability and relieving complaints related to chronic subluxation in the DRUJ.

Outcome Assessment after Aptis Distal Radioulnar Joint (DRUJ) Implant Arthroplasty

PubMed Central

Kachooei, Amir Reza; Chase, Samantha M; Jupiter, Jesse B

2014-01-01

Background: Conventional treatments after complicated injuries of the distal radioulnar joint (DRUJ) such as Darrach and Kapandji-Sauvé procedures have many drawbacks, which may eventually lead to a painful unstable distal ulna. The development of DRUJ prosthesis has significantly evolved over the past years. In this study, we assessed the outcome results of patients after DRUJ implant arthroplasty using the Aptis (Scheker) prosthesis. Methods: We identified 13 patients with 14 prosthesis during the past 10 years. Patients underwent DRUJ arthroplasty due to persistent symptoms of instability, chronic pain, and stiffness. Records and follow-up visits were reviewed to find the final post-operative symptoms, pain, range of motion, and grip strength with a mean follow-up of 12 months (range: 2-25 months). Also, patients were contacted prospectively by phone in order to administer the disabilities of the arm shoulder and hand (DASH), patient rated wrist evaluation (PRWE), and visual analogue scale (VAS), and to interview regarding satisfaction and progress in daily activities. Eleven patients out of 13 could be reached with a median follow-up time of 60 months (range: 2 to 102 months). Results: No patient required removal of the prosthesis. Only two patients underwent secondary surgeries in which both required debridement of the screw tip over the radius. The median DASH score, PRWE score, VAS, and satisfaction were 1.3, 2.5, 0, and 10, respectively. The mean range of flexion, extension, supination, and pronation was 62, 54, 51, and 64, respectively. Conclusions: Distal radioulnar joint injuries are disabling and patients usually undergo one or more salvage surgeries prior to receiving an arthroplasty. The Scheker prosthesis has shown satisfactory results with 100% survival rate in all reports. The constrained design of this prosthesis gives enough stability to prevent painful subluxation. PMID:25386579

Patient-accident-fracture (PAF) classification of acute distal radius fractures in adults.

PubMed

Herzberg, G; Galissard, T; Burnier, M

2018-05-19

There is not enough evidence in the literature to support the use of any classification system for distal radius fractures (DRF) in adults. However, there is a need for identification of more homogeneous groups of patients with DRF so that the extent of preoperative workup and sophistication of treatment would best match the needs of the patient. The authors propose an innovative method to analyse and stratify acute DRF in adults. A one-page chart includes criteria related to the patient (P), the energy of the accident (A) and the pathology of the fracture (F). Analysis of the pathology includes not only the distal radius itself but also the associated ulnar and carpal lesions. Radiological suspicion of associated carpal of distal radio-ulnar joint ligamentous injuries is included in the analysis. The preliminary results of the use of this chart in 1610 consecutive adult patients (16-102 years) with unilateral acute DRF are presented. A total of six homogeneous groups of patients are described, and the relevance of this classification regarding the therapeutic options is discussed.

Distal radius fractures result in alterations in scapular kinematics: a three-dimensional motion analysis.

PubMed

Ayhan, Cigdem; Turgut, Elif; Baltaci, Gul

2015-03-01

Scapular motion is closely integrated with arm motion. Injury to a distal segment requires compensatory changes in the proximal segments leading to alterations in scapular motion. Since the effects of distal injuries on scapular kinematics remain unknown, in the present study we investigated the influences on scapular motion in patients with distal injuries. Sixteen subjects with a history of distal radius fracture and 20 asymptomatic healthy subjects (controls) participated in the study. Three-dimensional scapular and humeral kinematic data were collected on all 3 planes of shoulder elevation: frontal, sagittal, and scapular. All testing was performed in a single session; therefore, the sensors remained attached to the participants for all testing. The position and orientation data of the scapula at 30°, 60°, 90°, and 120° humerothoracic elevation and 120°, 90°, 60°, and 30° lowering were used for statistical comparisons. Independent samples t-test was used to compare the scapular internal/external rotation, upward/downward rotation, and anterior/posterior tilt between the affected side of subjects with a distal radius fracture and the dominant side of asymptomatic subjects at the same stage of humerothoracic elevation. Scapular internal rotation was significantly increased at 30° elevation (P=0.01), 90° elevation (P=0.03), and 30° lowering (P=0.03), and upward rotation was increased at 30° and 60° elevation (P<0.001) on the affected side during frontal plane elevation. Scapular upward rotation and anterior tilt were significantly increased during 30° lowering on both the scapular (P=0.002 and 0.02, respectively) and sagittal planes (P=0.01 and 0.02. respectively). Patients with distal radius fractures exhibit altered scapular kinematics, which may further contribute to the development of secondary musculoskeletal pathologies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Appendicular and whole body lean mass outcomes are associated with finite element analysis-derived bone strength at the distal radius and tibia in adults aged 40years and older.

PubMed

Gibbs, Jenna C; Giangregorio, Lora M; Wong, Andy K O; Josse, Robert G; Cheung, Angela M

2017-10-01

The purpose of this cross-sectional study was to determine how appendicular lean mass index (ALMI), and whole body lean (LMI) and fat mass indices (FMI) associate with estimated bone strength outcomes at the distal radius and tibia in adults aged 40 years and older. Dual energy X-ray absorptiometry (DXA) scans were performed to determine body composition, including whole body lean and fat mass, and appendicular lean mass. ALMI (appendicular lean mass/height 2 ), LMI (lean tissue mass/height 2 ) and FMI (fat mass/height 2 ) were calculated. High-resolution peripheral quantitative computed tomography (HRpQCT) scans were performed to assess bone structural properties at the distal radius and tibia. Using finite element analysis, failure load (N), stiffness (N/mm), ultimate stress (MPa), and cortical-to-trabecular load ratio were estimated from HRpQCT scans. The associations between body composition (ALMI, LMI, FMI) and estimated bone strength were examined using bivariate and multivariable linear regression analyses adjusting for age, sex, and other confounding variables. In 197 participants (127 women; mean±SD, age: 69.5±10.3y, body mass index: 27.95±4.95kg/m 2 , ALMI: 7.31±1.31kg/m 2 ), ALMI and LMI were significantly associated with failure load at the distal radius and tibia (explained 39%-48% of the variance) and remained significant after adjusting for confounding variables and multiple testing (R 2 =0.586-0.645, p<0.001). ALMI, LMI, and FMI did not have significant associations with ultimate stress in our multivariable models. FMI was significantly associated with cortical-to-trabecular load ratio at the distal radius and tibia (explained 6%-12% of the variance) and remained significant after adjusting for confounders and multiple testing (R 2 =0.208-0.243, p<0.001). FMI was no longer significantly associated with failure load after adjusting for confounders. These findings suggest that ALMI and LMI are important determinants of estimated bone strength, particularly failure load, at the distal radius and tibia, and may contribute to preservation of bone strength in middle-to-late adulthood. Copyright © 2017 Elsevier Inc. All rights reserved.

Functional Consequence of Distal Brachioradialis Tendon Release: A Biomechanical Study

PubMed Central

Tirrell, Timothy F.; Franko, Orrin I.; Bhola, Siddharth; Hentzen, Eric R.; Abrams, Reid A.; Lieber, Richard L.

2013-01-01

Purpose Open reduction and internal fixation of distal radius fractures often necessitates release of the brachioradialis from the radial styloid. However, this common procedure has the potential to decrease elbow flexion strength. To determine the potential morbidity associated with brachioradialis release, we measured the change in elbow torque as a function of incremental release of the brachioradialis insertion footprint. Methods In 5 upper extremity cadaveric specimens, the brachioradialis tendon was systematically released from the radius, and the resultant effect on brachioradialis elbow flexion torque was measured. Release distance was defined as the distance between the release point and the tip of the radial styloid. Results Brachioradialis elbow flexion torque dropped to 95%, 90% and 86% of its original value at release distances of 27mm, 46mm, and 52mm, respectively. Importantly, brachioradialis torque remained above 80% of its original value at release distances up to 7 centimeters. Conclusions Our data demonstrate that release of the brachioradialis tendon from its insertion has minor effects on its ability to transmit force to the distal radius. Clinical Relevance These data may imply that release of the distal brachioradialis tendon during distal radius open reduction internal fixation can be performed without meaningful functional consequences to elbow flexion torque. Even at large release distances, overall elbow flexion torque loss after brachioradialis release would be expected to be less than 5% due to the much larger contributions of the biceps and brachialis. Use of the brachioradialis as a tendon transfer donor should not be limited by concerns of elbow flexion loss, and the tendon could be considered as an autograft donor. PMID:23528425

Interobserver Variability of Radiographic Assessment Using a Mobile Messaging Application as a Teleconsultation Tool

PubMed Central

Özkan, Sezai; Mellema, Jos J.; Ring, David; Chen, Neal C.

2017-01-01

Background: To examine whether interobserver reliability, decision-making, and confidence in decision-making in the treatment of distal radius fractures changes if radiographs are viewed on a messenger application on a mobile phone compared to a standard DICOM viewer. Methods: Radiographs of distal radius fractures were presented to surgeons on either a smart phone using a mobile messenger application or a laptop using a DICOM viewer application. Twenty observers participated: 10 (50%) were randomly assigned to the DICOM viewer group and 10 (50%) to the mobile messenger group. Each observer was asked to evaluate the cases and (1) classify the fracture type according to the AO classification, (2) recommend operative or conservative treatment and (3) rate their confidence about this decision. Results: There was no significant difference in interobserver reliability for AO classification and recommendation for surgery for distal radius fractures in both groups. The percentage of recommendation for surgery was significantly higher in the messenger application group compared to the DICOM viewer group (89% versus 78%, P=0.019) and the confidence for treatment decision was significantly higher in the mobile messenger group compared to the DICOM viewer group (8.9 versus 7.9, P=0.026). Conclusion: Messenger applications on mobile phones could facilitate remote decision-making for patients with distal radius fractures, but should be used with caution. PMID:29226202

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.

Dorsal or Volar Plate Fixation of the Distal Radius: Does the Complication Rate Help Us to Choose?

PubMed

Disseldorp, D J G; Hannemann, P F W; Poeze, M; Brink, P R G

2016-08-01

Internal fixation with plates is a reliable fixation technique for the treatment of distal radius fractures. An ongoing discussion exists whether volar or dorsal plating is the appropriate technique. In clinical practice, volar plate fixation is usually preferred because of the assumed lower complication frequency. However, recent studies with the newer generation low-profile dorsal plates reported lower complication rates. The aim of our study was to evaluate the differences in complication rates between volar and dorsal plate for the treatment of distal radius fractures in adult patients. A total of 214 patients with acute distal radius fractures were included in this retrospective study with a minimum 2 years of follow-up. In total, 123 patients were treated with dorsal plate fixation and 91 patients with volar plate fixation. Our primary study outcome was complication rate. The overall risk for complications was 15.4% in the dorsal group and 14.3% in the volar group (p = 0.81). A total of 19 patients had implant removal due to complications: 11 patients in the dorsal group and 8 patients in the volar group (p = 0.97). There is no preferred plate fixation technique based on these study results. In our opinion, decision for type of plate fixation should be based on fracture type and surgeon's experience with the specific approach and plate types. Therapeutic level III.

[Case-control study on transverse carpal ligament resection for the prevention of delayed carpal tunnel syndrome after distal radius fracture].

PubMed

Wang, Yan-jie; Wang, Shi-gang; Miao, Shu-juan; Su, Xia

2011-06-01

To investigate the effects of open reduction by palm side for the distal radius fracture and T shape plate internal fixation with simultaneous anterior transverse carpal ligament resection for the prevention of delayed carpal tunnel syndrome after operation. From March 2000 to March 2007, 32 patients (8 males and 24 females, ranging in age from 46 to 66 years) with distal radius fracture were treated with open reduction by palm side and T shape plate internal fixation with simultaneous anterior transverse carpal ligament resection; while 30 patients (7 males and 23 females,ranging in age from 45 to 65 years) only with open reduction by palm side and T shape plate internal fixation. The incidences of delayed carpal tunnel syndrome between the two groups were compared. Among 32 patients treated with open reduction by palm side and T shape plate internal fixation with anterior transverse carpal ligament resection, 3 patients had delayed carpal tunnel syndrome; while in 30 patients treated with open reduction by palm side and T shape plate internal fixation, 10 patients had delayed carpal tunnel syndrome. There was significant statistically difference (P < 0.05%). Simultaneous anterior transverse carpal ligament resection can effectively prevent the delayed carpal tunnel syndrome occurrence for the distal radius fracture with open reduction by palm side.

Midterm Follow-up of Treating Volar Marginal Rim Fractures with Variable Angle Lcp Volar Rim Distal Radius Plates.

PubMed

Goorens, Chul Ki; Geeurickx, Stijn; Wernaers, Pascal; Staelens, Barbara; Scheerlinck, Thierry; Goubau, Jean

2017-06-01

Specific treatment of the volar marginal rim fragment of distal radius fractures avoids occurance of volar radiocarpal dislocation. Although several fixation systems are available to capture this fragment, adequately maintaining internal fixation is difficult. We present our experience of the first 10 cases using the 2.4 mm variable angle LCP volar rim distal radius plate (Depuy Synthes®, West Chester, US), a low-profile volar rim-contouring plate designed for distal plate positioning and stable buttressing of the volar marginal fragment. Follow-up patient satisfaction, range of motion, grips strength, functional scoring with the QuickDASH and residual pain with a numeric rating scale were assessed. Radiological evaluation consisted in evaluating fracture consolidation, ulnar variance, volar angulation and maintenance of the volar rim fixation. The female to male ratio was 5:5 and the mean age was 52.2 (range, 17-80) years. The mean follow-up period was 11 (range, 5-19) months postoperatively. Patient satisfaction was high. The mean total flexion/extension range was 144° (range, 100-180°) compared to the contralateral uninjured side 160° (range, 95-180°). The mean total pronation/supination range was 153° (range, 140-180°) compared to the contralateral uninjured side 170° (range, 155-180°). Mean grip strength was 14 kg (range, 9-22), compared to the contralateral uninjured side 20 kg (range, 12-25 kg). Mean pre-injury level activity QuickDASH was 23 (range, 0-34.1), while post-recovery QuickDASH was 25 (range 0-43.2). Residual pain was 1.5 on the visual numerical pain rating scale. Radiological evaluation revealed in all cases fracture consolidation, satisfactory reconstruction of ulnar variance, volar angulation and volar rim. We encountered no flexor tendon complications, although plate removal was systematically performed after fracture consolidation. The 2.4 mm variable angle LCP volar rim distal radius plates is a valid treatment option for treating the volar marginal fragment in distal radius fractures.

Increased Cortical Porosity in Type-2 Diabetic Postmenopausal Women with Fragility Fractures

PubMed Central

Patsch, Janina M.; Burghardt, Andrew J.; Yap, Samuel P.; Baum, Thomas; Schwartz, Ann V.; Joseph, Gabby B.; Link, Thomas M.

2012-01-01

The primary goal of this study was to assess peripheral bone microarchitecture and strength in diabetic postmenopausal women with fragility fractures (DMFx) and to compare them with diabetic women without fracture (DM). Secondary goals were to assess differences in non-diabetic women with (Fx) and without fragility fractures (Co) and in women with (DM) and without diabetes (Co). Eighty women (mean age 61.3±5.7 yrs) were recruited into these groups (n=20 per group). Participants underwent DXA and high-resolution peripheral quantitative computed tomography (HR-pQCT) of the ultradistal and distal radius and tibia. In the HR-pQCT images volumetric bone mineral density, cortical and trabecular structure measures, including cortical porosity, were calculated. Bone strength was estimated using micro-finite element analysis (μFEA). Differential strength estimates were obtained with and without open cortical pores. At the ultradistal and distal tibia, DMFx had greater intracortical pore volume (+52.6%, p=0.009; +95.4%, p=0.020), relative porosity (+58.1%; p=0.005; +87.9%, p=0.011) and endocortical bone surface (+10.9%, p=0.031; +11.5%, 0.019) than DM. At the distal radius DMFx had 4.7-fold greater relative porosity (p=0.000) than DM. At the ultradistal radius, intracortical pore volume was significantly higher in DMFx than DM (+67.8%, p=0.018). DMFx also displayed larger trabecular heterogeneity (ultradistal radius; +36.8%, p=0.035), and lower total and cortical BMD (ultradistal tibia: −12.6%, p=0.031; −6.8%, p=0.011) than DM. DMFx exhibited significantly higher pore-related deficits in stiffness, failure load and cortical load fraction at the ultradistal and distal tibia, and the distal radius than DM. Comparing non-diabetic Fx and Co, we only found a non-significant trend with increase in pore volume (+38.9%, p=0.060) at the ultradistal radius. The results of our study suggest that severe deficits in cortical bone quality are responsible for fragility fractures in postmenopausal diabetic women. PMID:22991256

Uncemented three-dimensional-printed prosthetic replacement for giant cell tumor of distal radius: a new design of prosthesis and surgical techniques.

PubMed

Lu, Minxun; Min, Li; Xiao, Cong; Li, Yongjiang; Luo, Yi; Zhou, Yong; Zhang, Wenli; Tu, Chongqi

2018-01-01

Currently, it is challenging to treat giant cell tumor (GCT) of distal radius. For Campanacci grade III or recurrent GCTs, en bloc resection has been accepted as a better treatment option. Although numerous methods are available for reconstruction, all of them have some limitations in joint function and complications. In this study, our aims were to treat the GCT of distal radius with uncemented three-dimensional (3D)-printed prosthesis and to present and evaluate the surgical techniques and short-term outcomes. Between September 2015 and March 2017, 11 patients with distal radius GCTs were treated with personalized uncemented 3D-printed prosthesis. The preoperative/postoperative pain, range of motion, and grip strengths of all patients were evaluated. Oncological results, complications, and degenerative changes in the wrist joint were evaluated. Functional outcomes were assessed according to the disabilities of the arm, shoulder, and hand (DASH) questionnaire and Mayo wrist scoring systems. The average follow-up was 14.45 months (range, 8-18 months). There was a significant decrease in the mean postoperative visual analog scale score (2.33) compared with the preoperative score (5.22; p <0.001). The mean DASH score and Mayo wrist score of the wrist joint function were 18.7 and 72, respectively. There was no local recurrence or lung metastasis. No complication associated with prosthesis was observed, including aseptic loosening, subluxation, and breakage. Joint space narrowing, or disuse osteoporosis, was also not found in all cases. En bloc resection and reconstruction with a personalized uncemented 3D-printed prosthesis can be alternative options to treat Campanacci grade III or recurrent GCTs of distal radius and can result in short-term oncologic salvage, good postoperative function, and low complication rate. However, a long-term follow-up is required to determine the outcome.

The morphological characteristics of the antebrachiocarpal joint of the cheetah (Acinonyx jubatus).

PubMed

Ohale, L O C; Groenewald, H B

2003-03-01

A morphological study of the structures of the antebrachiocarpal (AC) joint of the cheetah was carded out by dissection of eight forelimbs obtained from four adult cheetahs culled from the Kruger National Park, Republic of South Africa. The aim was to evaluate the deviations of this joint from the normal feline pattern and to consider their possible relationship to the cheetah's adaptation to speed. Although published data on the AC joint of the other felids show general resemblance to that of the cheetah, there are nevertheless slight, but significant variations and modifications which tend to suggest adaptation to speed. The shafts of the radius and ulna of the cheetah are relatively straight and slender, with poorly developed distal ends. The ulnar notch is reduced to a very shallow concavity while the corresponding ulnar facet is a barely noticeable convexity, separated from the distal ulnar articular facet by an ill-defined groove. The movement of the distal radio-ulnar joint is highly restricted by the presence of a fibro-cartilaginous structure and a strong interrosseous membrane, limiting pronation and supination normally achieved by the rotation of the radius around the ulna. The extensor grooves at the distal extremity of the radius are deep and narrow and are guarded by prominent ridges. A thick extensor retinaculum anchors the strong extensor tendons in these grooves. The distal articular surface of the radius is concave in all directions except at the point where it moves into its stylold process. At this point it is convex in the dorsopalmar direction, with a surface that is rather deep and narrow. The proximal row of carpal bones presents a strongly convex surface, which is more pronounced in the dorsopalmar direction with the greatest convexity on the lateral aspect. Medially, there is a ridge-like concavity across the base of the tubercle, which rocks on the flexor surface of the radius, limiting excessive flexion as well as restricting lateral deviation of the AC joint.

Epidemiology of fragility fractures in Sakaiminato, Japan: incidence, secular trends, and prognosis.

PubMed

Tsukutani, Y; Hagino, H; Ito, Y; Nagashima, H

2015-09-01

We investigated the incidence of fragility fractures from 2010 to 2012 in Sakaiminato, Japan. The incidence rates of limb fractures in Sakaiminato were lower than in Caucasian populations but had increased relative to data obtained in Japan in the 1990s. Clinical vertebral fractures occurred at higher rates in Sakaiminato than in Caucasian populations. To elucidate the incidence and prognosis of fragility fractures in Sakaiminato, Japan. A survey of all hip, distal radius, proximal humerus, and clinical vertebral fractures was performed from 2010 to 2012 in patients aged 50 or older in Sakaiminato city, Tottori prefecture, Japan. The age- and gender-specific incidence rates (per 100,000 person-years) were calculated based on the population of Sakaiminato city each year. The incidence rates of hip, distal radius, and proximal humerus fractures were compared with previous reports. We conducted a follow-up study assessing patients within 1 year following their initial treatment at two Sakaiminato hospitals. The age-adjusted incidence rates in population aged 50 years or older (per 100,000 person-years) of hip, distal radius, proximal humerus, and clinical vertebral fractures were, respectively, 217, 82, 26, and 412 in males and 567, 432, 96, and 1229 in females. Age-specific incidence rates of hip, distal radius, and proximal humerus fractures all increased since the 1990s. Our study also revealed that anti-osteoporotic pharmacotherapy was prescribed 1 year post-fracture at rates of 29, 20, 30, and 50 % for patients with hip, distal radius, proximal humerus, and clinical vertebral fractures, respectively. The incidence rates of limb fractures in Sakaiminato were substantially lower than Caucasian populations in northern Europe but had increased relative to data obtained in Japan in the 1990s. Unlike upper and lower limb fractures, clinical vertebral fractures occurred at higher rates in our study population than in other Asian and North European countries.

Palmar reconstruction of the triangular fibrocartilage complex for instability of the distal radioulnar joint: a biomechanical study.

PubMed

Kataoka, T; Moritomo, H; Omokawa, S; Iida, A; Wada, T; Aoki, M

2013-06-01

We developed a new triangular fibrocartilage complex reconstruction technique for distal radioulnar joint instability in which the palmar portion of the triangular fibrocartilage complex was predominantly reconstructed, and evaluated whether such reconstruction can restore stability of the distal radioulnar joint in seven fresh cadaver upper extremities. Distal radioulnar joint instability was induced by cutting all soft-tissue stabilizers around the distal ulna. Using a palmar approach, a palmaris longus tendon graft was sutured to the remnant of the palmar radioulnar and ulnocarpal ligaments. The graft was then passed through a bone tunnel created at the fovea and was sutured. Loads were applied to the radius, and dorsopalmar displacements of the radius relative to the ulna were measured using an electromagnetic tracking device in neutral rotation, 60° supination and 60° pronation. We compared the dorsopalmar displacements before sectioning, before reconstruction and after reconstruction. Dorsopalmar instability produced by sectioning significantly improved in all forearm positions after reconstruction.

Factors associated with infection following open distal radius fractures.

PubMed

Glueck, Dane A; Charoglu, Constantine P; Lawton, Jeffrey N

2009-09-01

Open fractures are often classified according to a system described by Gustilo and Anderson. However, this system was applied to open long bone fractures, which may not predict the incidence of infection in open metaphyseal fractures of the upper extremity. Other studies have found that wound contamination and systemic illness were the best predictors of infections in open hand fractures. Our study assessed infection in open distal radius fractures and identifies factors that are associated with these infections. We hypothesize that contamination, rather than absolute wound size, is the best predictor of infection associated with open distal radius fractures. A review by CPT code yielded 42 patients with open distal radius fractures between 1997 and 2002 treated at a level one trauma center. Medical records and radiographic follow-up were reviewed to assess the time to irrigation and debridement, the number of debridements in initial treatment period, the method of operative stabilization, the Gustilo and Anderson type of fracture, the Swanson type of fracture, and description of wound contamination. Forty-two patients were followed up for an average of 15 months (range 4 to 68 months). Twenty-four fractures were classified as Gustilo and Anderson type I, ten were type II, and eight were type III, 30 were Swanson type I, and 12 were Swanson type II. Five of the 42 fractures were considered contaminated. Two were exposed to fecal contamination. The others were contaminated with tar, dirt/grass, and gravel, respectively. Three of 42 (7%) fractures developed infections. All three infected cases received a single irrigation and debridement. Two of five contaminated fractures (40%) developed a polymicrobial infection. Both were exposed to fecal contamination and, therefore, considered Swanson type II fractures. They were classified as Gustilo and Anderson type II and IIIB based solely upon the size of the wound. Both required multiple debridements and eventually wrist fusions. The third infection occurred in a Gustilo and Anderson type II and Swanson type I open fracture treated with one debridement and plate fixation. Hardware removal, debridement, and antibiotics resolved the infection. Three contaminated fractures that healed uneventfully received two debridements. Statistical analysis revealed a correlation with infection and contamination (p = 0.0331). The number of initial debridements played a role in infection, but was not statistically significant. No relationship between infection and time to initial irrigation and debridement, method of fixation, Gustilo and Anderson type, or Swanson type was found. We propose that open distal radius fractures behave differently than open long bone fractures. Infection developed in 7% of the distal radius fractures in our study and was significantly associated with wound contamination. We recommend that contamination be included as factor for prognosis in open distal radius fractures. Contaminated fractures should be treated with multiple debridements as part of the initial plan not based upon subsequent development of an infection.

Better Skeletal Microstructure Confers Greater Mechanical Advantages in Chinese-American Women Versus White Women

PubMed Central

Liu, X Sherry; Walker, Marcella D; McMahon, Donald J; Udesky, Julia; Liu, George; Bilezikian, John P; Guo, X Edward

2013-01-01

Despite lower areal bone mineral density (aBMD), Chinese-American women have fewer fractures than white women. We hypothesized that better skeletal microstructure in Chinese-American women in part could account for this paradox. Individual trabecula segmentation (ITS), a novel image-analysis technique, and micro–finite-element analysis (μFEA) were applied to high-resolution peripheral quantitative computed tomography (HR-pQCT) images to determine bone microarchitecture and strength in premenopausal Chinese-American and white women. Chinese-American women had 95% and 80% higher plate bone volume fraction at the distal radius and tibia, respectively, as well as 20% and 18% higher plate number density compared with white women (p < .001). With similar rodlike characteristics, the plate-to-rod ratio was twice as high in the Chinese-American than in white trabecular bone (p < .001). Plate-rod junction density, a parameter indicating trabecular network connections, was 37% and 29% greater at the distal radius and tibia, respectively, in Chinese-American women (p < .002). Moreover, the orientation of the trabecular bone network was more axially aligned in Chinese-American women because axial bone volume fraction was 51% and 32% higher at the distal radius and tibia, respectively, than in white women (p < .001). These striking differences in trabecular bone microstructure translated into 55% to 68% (distal radius, p < .001) and 29% to 43% (distal tibia, p < .01) greater trabecular bone strength, as assessed by Young’s moduli, in the Chinese-American versus the white group. The observation that Chinese-American women have a major microstructural advantage over white women may help to explain why their risk of fracture is lower despite their lower BMD. PMID:21351150

Biomechanical Testing of Distal Radius Fracture Treatments: Boundary Conditions Significantly Affect the Outcome of In Vitro Experiments.

PubMed

Synek, Alexander; Chevalier, Yan; Schröder, Christian; Pahr, Dieter H; Baumbach, Sebastian F

2016-04-01

The variety of experimental setups used during in vitro testing of distal radius fracture treatments impairs interstudy comparison and might lead to contradictory results. Setups particularly differ with respect to their boundary conditions, but the influence on the experimental outcome is unknown. The aim of this biomechanical study was to investigate the effects of 2 common boundary conditions on the biomechanical properties of an extra-articular distal radius fracture treated using volar plate osteosynthesis. Uniaxial compression tests were performed on 10 synthetic radii that were randomized into a proximally constrained group (ProxConst) or proximally movable group (ProxMove). The load was applied distally through a ball joint to enable distal fragment rotation. A significantly larger (ProxConst vs ProxMove) stiffness (671.6 ± 118.9 N·mm(-1) vs 259.6 ± 49.4 N·mm(-1)), elastic limit (186.2 ± 24.4 N vs 75.4 ± 20.2 N), and failure load (504.9 ± 142.5 N vs 200.7 ± 49.0 N) were found for the ProxConst group. The residual tilt did not differ significantly between the 2 groups. We concluded that the boundary conditions have a profound impact on the experimental outcome and should be considered more carefully in both study design and interstudy comparison.

[Roof folding and rotary pushing for the treatment of back to back fractures of distal radius and ulna in children].

PubMed

Xu, Ping; Dong, Xiao-jun; Lu, Zhou-tong; Wang, Gongjun; Zhang, Han-qing; Chen, Xuan-ning; Li, Dong

2015-09-01

To evaluate the technique and the clinical effect of folding roof and rotary pushing in treatment of children with distal radius and ulna fracture of "back to back". From January 2012 to February 2014,38 children with distal radius and ulna fracture of "back to back" were treated by using the technique of folding roof and rotary pushing to reset and splint fixation including 23 males and 15 females with an average age of 9.5 years old ranging from 6 to 14 years old. Injury time was from 45 min to 3 days (averaged 1.3 days). All cases was unilateral closed fracture without symptoms of nerve injury occurred. The wrist joint anteroposterior and lateral radiographs showed double fracture of radius and ulna, and the broken end of radius was typical "back to back" displacement. The quality of reduction was assessed according to Dienst recommendation on the combination of Aro measurement, and the therapeutic effect was evaluated using standard of Anderson function. All patients were followed up from 3 to 13 months with an average of 6 months. There were no iatrogenic nerve injury. Thirty cases were treated successfully for the first time, 8 cases were again reset successfully; 28 cases were anatomical reduction, 7 cases were near anatomic reduction, 3 cases were functional reduction. At the second day 7 cases with hand and finger swelling appeared in multiple reset patients. Quality results of reduction were excellent in 33 cases, good in 5 cases. According to the standard of Anderson function evaluation, 35 cases were excellent, 3 cases were good. All fractures were healed with of deformity of wrist. Using the technique of folding roof and rotary pushing in treatment of children with distal radius and ulna fracture of "back to back" is very successful, the patient's limb function recovered well, the whole operation process is simple.

Incidence and clinical outcomes of tendon rupture following distal radius fracture.

PubMed

White, Brian D; Nydick, Jason A; Karsky, Dawnne; Williams, Bailee D; Hess, Alfred V; Stone, Jeffrey D

2012-10-01

To evaluate the incidence of tendon rupture after nonoperative and operative management of distal radius fractures, report clinical outcomes after tendon repair or transfer, and examine volar plate and dorsal screw prominence as a predictor of tendon rupture. We performed a retrospective chart review on patients treated for tendon rupture after distal radius fracture. We evaluated active range of motion, Disabilities of Arm, Shoulder, and Hand score, grip strength, and pain score, and performed radiographic evaluation of volar plate and dorsal screw prominence in both the study group and a matched control group. There were 6 tendon ruptures in 1,359 patients (0.4%) treated nonoperatively and 8 tendon ruptures in 999 patients (0.8%) treated with volar plate fixation. At the time of final follow-up, regardless of treatment, we noted that patients had minimal pain and excellent motion and grip strength. Mean Disabilities of the Shoulder, Arm, and Hand scores were 6 for patients treated nonoperatively and 4 for those treated with volar plating. We were unable to verify volar plate or dorsal screw prominence as independent risk factors for tendon rupture after distal radius fractures. However, we recommend continued follow-up and plate removal for symptomatic patients who have volar plate prominence or dorsal screw prominence. In the event of tendon rupture, we report excellent clinical outcomes after tendon repair or tendon transfer. Therapeutic IV. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Effectiveness of external fixator combined with T-plate internal fixation for the treatment of comminuted distal radius fractures.

PubMed

Han, L R; Jin, C X; Yan, J; Han, S Z; He, X B; Yang, X F

2015-03-31

This study compared the efficacy between external fixator combined with palmar T-plate internal fixation and simple plate internal fixation for the treatment of comminuted distal radius fractures. A total of 61 patients classified as type C according to the AO/ASIF classification underwent surgery for comminuted distal radius fractures. There were 54 and 7 cases of closed and open fractures, respectively. Moreover, 19 patients received an external fixator combined with T-plate internal fixation, and 42 received simple plate internal fixation. All patients were treated successfully during 12-month postoperative follow-up. The follow-up results show that the palmar flexion and dorsiflexion of the wrist, radial height, and palmar angle were significantly better in those treated with the external fixator combined with T-plate compared to those treated with the simple plate only (P < 0.05); however, there were no significant differences in radial-ulnar deviation, wrist range of motion, or wrist function score between groups (P > 0.05). Hence, the effectiveness of external fixator combined with T-plate internal fixation for the treatment of comminuted distal radius fractures was satisfactory. Patients sufficiently recovered wrist, forearm, and hand function. In conclusion, compared to the simple T-plate, the external fixator combined with T-plate internal fixation can reduce the possibility of the postoperative re-shifting of broken bones and keep the distraction of fractures to maintain radial height and prevent radial shortening.

Fragment-Specific Fixation Versus Volar Locking Plates in Primarily Nonreducible or Secondarily Redisplaced Distal Radius Fractures: A Randomized Controlled Study.

PubMed

Landgren, Marcus; Abramo, Antonio; Geijer, Mats; Kopylov, Philippe; Tägil, Magnus

2017-03-01

To compare the patient-reported, clinical, and radiographic outcome of 2 methods of internal fixation in distal radius fractures. Fifty patients, mean age 56 years (range, 21-69 years) with primarily nonreducible or secondarily redisplaced distal radius fractures were randomized to open reduction internal fixation using volar locking plates (n = 25) or fragment-specific fixation (n = 25). The patients were assessed on grip strength, range of motion, patient-reported outcome (Quick Disabilities of the Arm, Shoulder, and Hand), pain (visual analog scale), health-related quality of life (Short Form-12 [SF-12]), and radiographic evaluation. Grip strength at 12 months was the primary outcome measure. At 12 months, no difference was found in grip strength, which was 90% of the uninjured side in the volar plate group and 87% in the fragment-specific fixation group. No differences were found in range of motion and the median Quick Disabilities of the Arm, Shoulder, and Hand score was 5 in both groups. The overall complication rate was significant, 21% in the volar locking plate group, compared with 52% in the fragment-specific group. In treatment of primarily nonreducible or secondarily redisplaced distal radius fractures, volar locking plates and fragment-specific fixation both achieve good and similar patient-reported outcomes, although more complications were recorded in the fragment-specific group. Therapeutic II. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

The International Classification of Functioning as an explanatory model of health after distal radius fracture: A cohort study

PubMed Central

Harris, Jocelyn E; MacDermid, Joy C; Roth, James

2005-01-01

Background Distal radius fractures are common injuries that have an increasing impact on health across the lifespan. The purpose of this study was to identify health impacts in body structure/function, activity, and participation at baseline and follow-up, to determine whether they support the ICF model of health. Methods This is a prospective cohort study of 790 individuals who were assessed at 1 week, 3 months, and 1 year post injury. The Patient Rated Wrist Evaluation (PRWE), The Wrist Outcome Measure (WOM), and the Medical Outcome Survey Short-Form (SF-36) were used to measure impairment, activity, participation, and health. Multiple regression was used to develop explanatory models of health outcome. Results Regression analysis showed that the PRWE explained between 13% (one week) and 33% (three months) of the SF-36 Physical Component Summary Scores with pain, activities and participation subscales showing dominant effects at different stages of recovery. PRWE scores were less related to Mental Component Summary Scores, 10% (three months) and 8% (one year). Wrist impairment scores were less powerful predictors of health status than the PRWE. Conclusion The ICF is an informative model for examining distal radius fracture. Difficulty in the domains of activity and participation were able to explain a significant portion of physical health. Post-fracture rehabilitation and outcome assessments should extend beyond physical impairment to insure comprehensive treatment to individuals with distal radius fracture. PMID:16288664

How well can step-off and gap distances be reduced when treating intra-articular distal radius fractures with fragment specific fixation when using fluoroscopy.

PubMed

Thiart, M; Ikram, A; Lamberts, R P

2016-12-01

Although fragment specific fixation has proved to be an effective treatment regime, it has not been established how successfully this treatment could be performed using fluoroscopy and what the added value of arthroscopy could be. Establish gap and step-off distances after in intra-articular distal radius fractures that have been treated with fragment specific fixation while using fluoroscopy. Forty-four patients with an intra-articular distal radius fracture were treated with fragment specific fixation while using fluoroscopy. After the treatment of the intra-articular distal radius fracture with fragment specific fixation and the use of fluoroscopy, but before the completion of the surgical intervention, all gap, and step-off distances were determined by using arthroscopy. In addition, the joint was checked for any other wrist pathologies. Arthroscopy after the surgical intervention showed that in 37 patients no gap distances could be detected, while in six patients a gap distance of≤2mm was found and in one patient, a gap distance of 3mm. Similarly, arthroscopy revealed no step-off distances in 33 patients, while in 11 patients a step-off distance of≤2mm was found. Although additional wrist pathologies were found in 48% of our population, only one patient needed surgical intervention. Three months after the surgical intervention wrist flexion was 41±10°, wrist extension 51±17°, ulnar deviation 19±10°, radial deviation 32±12° while patients could pronate and supinate their wrist to 85±5° and 74±20°, respectively. Intra-articular distal radius fractures can be treated successfully with fragment specific fixation and the use of fluoroscopy. As almost all gap and step-off distances could be reduced to an acceptable level, the scope for arthroscopy to further improve this treatment regime is limited. The functional outcome scores that were found 3 months after the surgical intervention were similar to what has been reported in other studies using different treatment option. These findings suggest that fragment specific fixation is a good alternative for treating intra-articular distal radius fractures. As in most cases, only fluoroscopy is needed for fragment specific fixation, this treatment technique is a good treatment option for resource-limited hospitals, setting who do not have access to arthroscopy. III, case-control study. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A longitudinal study of bone area, content, density, and strength development at the radius and tibia in children 4-12 years of age exposed to recreational gymnastics.

PubMed

Jackowski, S A; Baxter-Jones, A D G; Gruodyte-Raciene, R; Kontulainen, S A; Erlandson, M C

2015-06-01

This study investigated the long-term relationship between the exposure to childhood recreational gymnastics and bone measures and bone strength parameters at the radius and tibia. It was observed that individuals exposed to recreational gymnastics had significantly greater total bone content and area at the distal radius. No differences were observed at the tibia. This study investigated the relationship between exposure to early childhood recreational gymnastics with bone measures and bone strength development at the radius and tibia. One hundred twenty seven children (59 male, 68 female) involved in either recreational gymnastics (gymnasts) or other recreational sports (non-gymnasts) between 4 and 6 years of age were recruited. Peripheral quantitative computed tomography (pQCT) scans of their distal and shaft sites of the forearm and leg were obtained over 3 years, covering the ages of 4-12 years at study completion. Multilevel random effects models were constructed to assess differences in the development of bone measures and bone strength measures between those exposed and not exposed to gymnastics while controlling for age, limb length, weight, physical activity, muscle area, sex, and hours of training. Once age, limb length, weight, muscle area, physical activity, sex, and hours of training effects were controlled, it was observed that individuals exposed to recreational gymnastics had significantly greater total bone area (18.0 ± 7.5 mm(2)) and total bone content (6.0 ± 3.0 mg/mm) at the distal radius (p < 0.05). This represents an 8-21 % benefit in ToA and 8-15 % benefit to ToC from 4 to 12 years of age. Exposure to recreational gymnastics had no significant effect on bone measures at the radius shaft or at the tibia (p > 0.05). Exposure to early life recreational gymnastics provides skeletal benefits to distal radius bone content and area. Thus, childhood recreational gymnastics exposure may be advantageous to bone development at the wrist.

[Injury to the Scapholunate Ligament in Distal Radius Fractures: Peri-Operative Diagnosis and Treatment Results].

PubMed

Gajdoš, R; Pilný, J; Pokorná, A

2016-01-01

PURPOSE OF THE STUDY Injury to the scapholunate ligament is frequently associated with a fracture of the distal radius. At present neither a unified concept of treatment nor a standard method of diagnosis in these concomitant injuries is available. The aim of the study was to evaluate a group of surgically treated patients with distal radius fractures in order to assess a contribution of combined conventional X-ray and intra-operative fluoroscopic examinations to the diagnosis of associated lesions and to compare short-term functional outcomes of sugically treated patients with those of patients treated conservatively. MATERIAL AND METHODS A group of patients undergoiong surgery for distal radius fractures using plate osteosynthesis was evaluated retrospectively. The peri-operative diagnosis of associated injury to the scapholunate ligament was based on pre-operative standard X-ray views and intra-operative fluoroscopy. The latter consisted of images of maximum radial and ulnar deviation as well as an image of the forearm in traction exerted manually along the long axis. All views were in postero-anterior projection. Results were read directly on the monitor of a fluoroscopic device after its calibration or were obtained by comparing the thickness of an attached Kirschner wire with the distance to be measured. Subsequently, pixels were converted to millimetres. When a scapholunate ligament injury was found and confirmed by examination of the contralateral wrist, the finding was verified by open reduction or arthroscopy. Both static and dynamic instabilities were treated together with the distal radius fracture at one-stage surgery. After surgery, the patients without ligament injury had the wrist immobilised for 4 weeks, then rehabilitation followed. In the patients with a damaged ligament, immobilisation in a short brace lasted until transarticular wires were removed. All patients were followed up for a year at least. At follow-up, the injured wrist was examined for signs of clinical instability of the scapholunate joint, functional outcome was assessed using the Mayo Wrist Score (MWS) and pain intensity was evaluated on the Visual Analoque Scale (VAS). Restriction in daily activities was rated by the Quick Disabilities of the Arm, Shoulder and Hand (QDASH) score and plain X-ray was done. If any of the results was not satisfactory, MRI examination was indicated. RESULTS Of a total of 265 patients, 35 had injury to the scapholunate joint, 16 had static instability diagnosed by a standard fluoroscopic examination and nine patients with an acute phase of injury remained undiagnosed. For detection of associated scapholunate injuries, a standard X-ray examination had sensitivity of 46%, specificity of 99%, accuracy of 92%, positive predictive value of 84%, negative predictive value of 92%, positive likelihood ratio = 35.05 and negative likelihood ratio = 0.55. Dynamic fluoroscopic examination showed sensitivity of 53%, specificity of 99%, accuracy of 95%, positive predictive value of 77%, negative predictive value of 96%, positive likelihood ratio = 36.49 and negative likelihood ratio = 0.48. Using the MWS system, no differences in the outcome of scapholunate instability treatment were found between the patients undergoing surgery and those treated conservatively (p=0.35). Statistically significant differences were detected in the evaluation of subjective parameters - both VAS and QDASH scores were better in the treated than non-treated patients (p=0.02 and p=0.04, respectively). DISCUSSION The high negative predictive values of both standard X-ray and intra-operative fluoroscopy showed that combined use of the two method is more relevant for excluding than for confirming an injury to the scapholunate ligament concomitant with distal radius fracture. Similarly, the low negative likelihood ratio showed that a negative result decreases the pre-test probability of concomitant injury. CONCLUSIONS Negative findings of scapholunate ligament injury on standard X-ray views and intra-operative fluoroscopic images make it unnecessary to perform any further intra-operative examination to detect injury to the scapholunate ligament. Positive findings require verification of the degree of injury by another intra-operative modality, most ideally by arthroscopy. Patients with untreated instability associated with distal radius fracture have, at short-term follow-up, no statistically significant differences in functioning of the injured extremity in comparison with treated patients. Subjectively, however, they feel more pain and more restriction in performing daily activities. Therefore, the treatment of an injured scapholunate ligament together with distal radius fracture at one-stage surgery seems to be a good alternative for the patient. Key words: distal radius fractures, scapholunate ligament, radiographic, diagnosis, outcome distal radius fracture.

Equine ulnar fracture repair with locking compression plates can be associated with inadvertent penetration of the lateral cortex of the radius.

PubMed

Kuemmerle, Jan M; Kühn, Karolin; Bryner, Marco; Fürst, Anton E

2013-10-01

To evaluate if the use of locking head screws (LHS) in the distal holes of a locking compression plate (LCP) applied to the caudal aspect of the ulna to treat equine ulnar fractures is associated with a risk of injury to the lateral cortex of the radius. Controlled laboratory study. Cadaveric equine forelimbs (n = 8 pair). After transverse ulnar osteotomy, osteosynthesis was performed with a narrow 10-13 hole 4.5/5.0 LCP applied to the caudal aspect of each ulna. The distal 3 holes were filled with 4.5 mm cortex screws (CS) in 1 limb (group 1) and with 5.0 mm LHS contralaterally (group 2). CS were inserted in an angle deemed appropriate by the surgeon and LHS were inserted perpendicular to the plate. Implant position and injury to the lateral cortex of the radius were assessed by radiography, CT, and limb dissection. In group 1, injury of the lateral radius cortex did not occur. In group 2, 4 limbs and 6/24 LHS were associated with injury of the lateral radius cortex by penetration of a LHS. This difference was statistically significant. CS were inserted with a mean angle of 17.6° from the sagittal plane in a caudolateral-craniomedial direction. Use of LHS in the distal part of a LCP applied to the caudal aspect of the ulna is associated with a risk of inadvertent injury to the lateral cortex of the radius. © Copyright 2013 by The American College of Veterinary Surgeons.

Primary hyperparathyroidism associated with a giant cell tumor: One case in the distal radius.

PubMed

Ouzaa, M R; Bennis, A; Iken, M; Abouzzahir, A; Boussouga, M; Jaafar, A

2015-10-01

Hyperparathyroidism can present itself as brown tumors (or osteolytic expansive lesions) that usually disappear after normalization of calcium and phosphate levels. It rarely occurs simultaneously with a giant cell tumor. The authors report one case of a localized form at the distal radius in a patient being followed for primary hyperparathyroidism. The diagnostic challenges related to the clinical and radiological similarities of these two pathological entities are discussed, as they can lead to delays in therapeutic management. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

[Fractures of the distal forearm. Which therapy is indicated when?].

PubMed

Brug, E; Joosten, U; Püllen, M

2000-04-01

Every 15th case of a bone fracture in patients aged more than 65 years concerns the distal radius in Germany. This means the second rank of all geriatric fractures following fractures of the hip. According to the approved and increased apply of operative stabilisation there are arising more and more reports upon poor results of nonsurgical treatment. Especially in older patients the main reason for the discontented outcome of conservative management is osteoporosis, which is an affirmative circumstance for the genesis of fracture but also for secondary mal-aligment of comminuted thin cortical walls and crushed porotic cancellous bone. The rational of this perception is either filling artificial bonelike tissue--avoiding the need of harvest cancellous bone graft from a second surgical site--into the resultant cavity following reduction, or supplementary trans-styloidal or intrafocal K-wiring until remodeling is obtained within an average of 10 weeks. Both arrangements should be secured in addition with a trans-articular external fixation. According to a literature review and our own experiences of 92 follow up cases of distal radius fractures in patients who were older than 65 years this procedure seems to be superior at present for A-2, A-3 and most cases of type-C fractures of the distal radius, despite the disadvantage of joint immobilisation for about 5 weeks. Type B-fractures, however, should be provided better with an internal fixation. Sudeck's algodystrophia is the mostly serious complication of the distal radius fracture and its treatment in older patients. Recognising punctually neurovegetative stimulated patients, treat them cautiously and coming in on their special situation is usually the best way to reduce this risk. To pay attention to the topography of the nerves during the application of the pins and to act at the first signs of complications immediately is also very important. We examined 92 patients who were older than 65 years with a fracture of the distal end of the radius in a follow up study. In this group we treated 62 distal radius fractures of the type A and C of the AO classification with an trans-articular external fixateur and with supplementary measures if necessary. Additionally we filled the bone cavity with an artificial bone graft (Endobon) following closed reduction in 32 cases, 12 times a complementary K-wiring was added and in 8 cases the external fixateur was combined with both. Sudeck's disease appeared in 1.1% of all cases. In 5 cases we recorded complications with an obligation to treatment as well. Lesion of the superficial branch of the radial nerve were noted in 2 cases (2.1%), as far as we extended the surgical approach for the pin application. Technical problems from the site of the external fixateur appeared in 3 cases, two of them could be attributed to an infirmity of the fixateurs ball joints which is now eliminated by the producer. 4 patients with a type-B fracture was provided by plating, additionally 4 patients with a type-C fracture because of non-compliance. The external fixateur is an essential part of a differentiated treatment with reference to the several types of distal radius fractures in older patients.

On the interaction of Tollmien-Schlichting waves in axisymmetric supersonic flows

NASA Technical Reports Server (NTRS)

Duck, P. W.; Hall, P.

1988-01-01

Two-dimensional lower branch Tollmien-Schlichting waves described by triple-deck theory are always stable for planar supersonic flows. The possible occurrence of axisymmetric unstable modes in the supersonic flow around an axisymmetric body is investigated. In particular flows around bodies with typical radii comparable with the thickness of the upper deck are considered. It is shown that such unstable modes exist below a critical nondimensional radius of the body a sub 0. At values of the radius above a sub 0 all the modes are stable while if unstable modes exist they are found to occur in pairs. The interaction of these modes in the nonlinear regime is investigated using a weakly nonlinear approach and it is found that, dependent on the frequencies of the imposed Tollmien-Schlichting waves, either of the modes can be set up.

On the interaction of Tollmien-Schlichting waves in axisymmetric supersonic flows

NASA Technical Reports Server (NTRS)

Duck, P. W.; Hall, P.

1989-01-01

Two-dimensional lower branch Tollmien-Schlichting waves described by triple-deck theory are always stable for planar supersonic flows. The possible occurrence of axisymmetric unstable modes in the supersonic flow around an axisymmetric body is investigated. In particular flows around bodies with typical radii comparable with the thickness of the upper deck are considered. It is shown that such unstable modes exist below a critical nondimensional radius of the body a sub O. At values of the radius above a sub O all the modes are stable while if unstable modes exist they are found to occur in pairs. The interaction of these modes in the nonlinear regime is investigated using a weakly nonlinear approach and it is found that, dependent on the frequencies of the imposed Tollmien-Schlichting waves, either of the modes can be set up.

Soft cast versus rigid cast for treatment of distal radius buckle fractures in children.

PubMed

Witney-Lagen, Caroline; Smith, Christine; Walsh, Graham

2013-04-01

Buckle fractures are extremely common and their optimum management is still under debate. This study aimed to ascertain whether buckle fractures of the distal radius can be safely and effectively treated in soft cast with only a single orthopaedic outpatient clinic appointment. A total of 232 children with buckle fractures of the distal radius were included in the study. 111 children with 112 distal radius fractures were treated in full rigid cast and 121 children with 123 fractures were treated with soft cast. The rigid cast children attended outpatient clinic for removal of cast at 3 weeks. Soft casts were removed by parents unwinding the cast at home after 3 weeks. Follow-up was conducted prospectively by telephone questionnaire at an average of 6 weeks post-injury. Outcome data were available for 117 children treated in soft cast and for 102 children treated in rigid cast. The most common mechanism of injury was a fall sustained from standing or running, followed by falls from bikes and then trampoline accidents. Overall, both groups recovered well. Overall satisfaction with the outcome of treatment was 97.4% in soft cast and 95.2% in rigid cast. Casts were reported as comfortable by 95.7% in soft cast and 93.3% in rigid cast. Cast changes were required for 6.8% of soft casts and 11.5% of rigid casts. The most frequent cause for changing rigid casts was getting the cast wet. None of the improved scores seen in the soft cast group were statistically significant. No re-fractures were seen in either group. Nearly all (94.9%) children in soft cast did bathe, shower or swim in their cast. Parents of both groups preferred treatment with soft cast (p < 0.001). Reasons given for preferring the soft cast included the ability to get the cast wet, avoidance of the plaster saw and not having to take time off work to attend a follow-up visit for cast removal. Buckle fractures of the distal radius can be safely and effectively treated in soft cast with only a single orthopaedic outpatient clinic appointment. Copyright © 2012 Elsevier Ltd. All rights reserved.

A combined randomised and observational study of surgery for fractures in the distal radius in the elderly (CROSSFIRE)—a study protocol

PubMed Central

Harris, Ian, A; Naylor, Justine, M; Buchbinder, Rachelle; Ivers, Rebecca; Balogh, Zsolt; Smith, Paul; Mittal, Rajat; Xuan, Wei; Howard, Kirsten; Vafa, Arezoo; Yates, Piers; Rieger, Bertram; Smith, Geoff; Elkinson, Ilia; Kim, Woosung; Chehade, Mellick; Sungaran, Jai; Latendresse, Kim; Wong, James; Viswanathan, Sameer; Richardson, Martin; Shrestha, Kush; Drobetz, Herwig; Tran, Phong; Loveridge, Jeremy; Page, Richard; Hau, Raphael; Bingham, Roger; Mulford, Jonathan; Incoll, Ian

2017-01-01

Fractures of the distal radius are common and occur in all age groups. The incidence is high in older populations due to osteoporosis and increased falls risk. Considerable practice variation exists in the management of distal radius fractures in older patients ranging from closed reduction with cast immobilisation to open reduction with plate fixation. Plating is currently the most common surgical treatment. While there is evidence showing no significant advantage for some forms of surgical fixation over conservative treatment, and no difference between different surgical techniques, there is a lack of evidence comparing two of the most common treatments used: closed reduction and casting versus plating. Surgical management involves significant costs and risks compared with conservative management. High-level evidence is required to address practice variation, justify costs and to provide the best clinical outcomes for patients. Methods and analysis This pragmatic, multicentre randomised comparative effectiveness trial aims to determine whether plating leads to better pain and function and is more cost-effective than closed reduction and casting of displaced distal radius fractures in adults aged 60 years and older. The trial will compare the two techniques but will also follow consenting patients who are unwilling to be randomised in a separate, observational cohort. Inclusion of non-randomised patients addresses selection bias, provides practice and outcome insights about standard care, and improves the generalisability of the results from the randomised trial. Ethics and dissemination CROSSFIRE(Combined Randomised and Observational Study of Surgery for Fractures In the distal Radius in the Elderly) was reviewed and approved by The Hunter New England HREC (HNEHREC Reference No: 16/02/17/3.04). The results of the trial will be published in a peer-reviewed journal and will be disseminated via various forms of media. Results will be incorporated in clinical recommendations and practice guidelines produced by professional bodies. Registration CROSSFIRE has been registered with the Australian and New Zealand Clinical Trials Registry (ANZCTR: ACTRN12616000969460). PMID:28645976

A combined randomised and observational study of surgery for fractures in the distal radius in the elderly (CROSSFIRE)-a study protocol.

PubMed

Harris, Ian A; Naylor, Justine M; Lawson, Andrew; Buchbinder, Rachelle; Ivers, Rebecca; Balogh, Zsolt; Smith, Paul; Mittal, Rajat; Xuan, Wei; Howard, Kirsten; Vafa, Arezoo; Yates, Piers; Rieger, Bertram; Smith, Geoff; Elkinson, Ilia; Kim, Woosung; Chehade, Mellick; Sungaran, Jai; Latendresse, Kim; Wong, James; Viswanathan, Sameer; Richardson, Martin; Shrestha, Kush; Drobetz, Herwig; Tran, Phong; Loveridge, Jeremy; Page, Richard; Hau, Raphael; Bingham, Roger; Mulford, Jonathan; Incoll, Ian

2017-06-23

Fractures of the distal radius are common and occur in all age groups. The incidence is high in older populations due to osteoporosis and increased falls risk. Considerable practice variation exists in the management of distal radius fractures in older patients ranging from closed reduction with cast immobilisation to open reduction with plate fixation. Plating is currently the most common surgical treatment. While there is evidence showing no significant advantage for some forms of surgical fixation over conservative treatment, and no difference between different surgical techniques, there is a lack of evidence comparing two of the most common treatments used: closed reduction and casting versus plating. Surgical management involves significant costs and risks compared with conservative management. High-level evidence is required to address practice variation, justify costs and to provide the best clinical outcomes for patients. This pragmatic, multicentre randomised comparative effectiveness trial aims to determine whether plating leads to better pain and function and is more cost-effective than closed reduction and casting of displaced distal radius fractures in adults aged 60 years and older. The trial will compare the two techniques but will also follow consenting patients who are unwilling to be randomised in a separate, observational cohort. Inclusion of non-randomised patients addresses selection bias, provides practice and outcome insights about standard care, and improves the generalisability of the results from the randomised trial. CROSSFIRE(Combined Randomised and Observational Study of Surgery for Fractures In the distal Radius in the Elderly) was reviewed and approved by The Hunter New England HREC (HNEHREC Reference No: 16/02/17/3.04). The results of the trial will be published in a peer-reviewed journal and will be disseminated via various forms of media. Results will be incorporated in clinical recommendations and practice guidelines produced by professional bodies. CROSSFIRE has been registered with the Australian and New Zealand Clinical Trials Registry (ANZCTR: ACTRN12616000969460). © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

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 Kirschner wires or volar locking plates. Kirschner wire fixation, however, is cheaper and quicker to perform. Current Controlled Trials ISCRTN 31379280. UKCRN 8956. © Costa et al 2014.

Catastrophic Thinking Is Associated With Finger Stiffness After Distal Radius Fracture Surgery.

PubMed

Teunis, Teun; Bot, Arjan G J; Thornton, Emily R; Ring, David

2015-10-01

To identify demographic, injury-related, or psychologic factors associated with finger stiffness at suture removal and 6 weeks after distal radius fracture surgery. We hypothesize that there are no factors associated with distance to palmar crease at suture removal. Prospective cohort study. Level I Academic Urban Trauma Center. One hundred sixteen adult patients underwent open reduction and internal fixation of their distal radius fractures; 96 of whom were also available 6 weeks after surgery. None. At suture removal, we recorded patients' demographics, AO fracture type, carpal tunnel release at the time of surgery, pain catastrophizing scale, Whiteley Index, Patient Health Questionnaire-9, and disabilities of the arm, shoulder, and hand questionnaire, 11-point ordinal measure of pain intensity, distance to palmar crease, and active flexion of the thumb through the small finger. At 6 weeks after surgery, we measured motion, disabilities of the arm, shoulder, and hand, and pain intensity. Prereduction and postsurgery radiographic fracture characteristics were assessed. Female sex, being married, specific surgeons, carpal tunnel release, AO type C fractures, and greater catastrophic thinking were associated with increased distance to palmar crease at suture removal. At 6 weeks, greater catastrophic thinking was the only factor associated with increased distance to palmar crease. Catastrophic thinking was a consistent and major determinant of finger stiffness at suture removal and 6 weeks after injury. Future research should assess if treatments that ameliorate catastrophic thinking can facilitate recovery of finger motion after operative treatment of a distal radius fracture. Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Significance of a Pronator Quadratus–Sparing Approach for Volar Locking Plate Fixation of Comminuted Intra-articular Fractures of the Distal Radius

PubMed Central

Itoh, Soichiro; Yumoto, Myu; Kanai, Misa; Yoshida, Wataru; Yoshioka, Taro

2016-01-01

Background: The preservation of the integrity of the pronator quadratus (PQ) muscle is expected to have many benefits, particularly in cases of highly comminuted intra-articular fractures of the distal radius. Therefore, we examined the significance of a PQ muscle–sparing approach for volar locking plate (VLP) fixation of these types of fractures. Methods: Sixty-five patients who sustained AO Foundation and Orthopaedic Trauma Association (AO/OTA) type C2 and C3 distal radius fractures were treated with VLP fixation using either a PQ muscle release and repair (PQ-releasing group, n = 30) or a PQ muscle–sparing approach (PQ-sparing group, n = 35). Radiographic parameters, active range of motion (ROM), percentage of the grip power of the injured hand compared with that of the opposite hand, wrist pain visual analog scale (VAS) score, and Quick Disability of the Arm, Shoulder, and Hand (DASH) score (disability/symptom) were evaluated monthly up to 12 months after surgery. Results: The mean VAS score was significantly lower in the PQ-sparing group at 2, 3, and 4 months postoperatively than in the PQ-releasing group. Furthermore, the mean Quick DASH score in the PQ-sparing group was significantly lower than that in the PQ-releasing group at 1 and 2 months postoperatively. There were no significant differences, however, in the other functional parameters in the groups through the observation period. Conclusions: The PQ muscle–sparing approach appears to achieve satisfactory results in patients undergoing VLP fixation of comminuted intra-articular fractures of the distal radius. PMID:27418895

Dorsal Arthroscopic Approach and Intra-Articular Anatomy of the Bovine Antebrachiocarpal and Middle Carpal Joints.

PubMed

Lardé, Hélène; Nichols, Sylvain; Babkine, Marie; Desrochers, André

2016-07-01

To determine arthroscopic approaches to the dorsal synovial compartments of the antebrachiocarpal and middle carpal joints in adult cattle, and to describe the arthroscopic intra-articular anatomy from each approach. Ex vivo study. Six fresh adult bovine cadavers. Two carpi were injected with latex and dissected to determine the ideal location for arthroscopic portals. Arthroscopy of the antebrachiocarpal and middle carpal joints of 10 carpi was then performed. The dorsolateral approach was made between the extensor carpi radialis and common digital extensor tendons. The dorsomedial approach was made medial to the extensor carpi radialis tendon, midway between the distal radius and proximal row of carpal bones (antebrachiocarpal joint) and midway between the two rows of carpal bones (middle carpal joint), with the joint in flexion. Arthroscopy of the antebrachiocarpal joint allowed visualization of the distal radius, proximal aspect of the radial, intermediate and ulnar carpal bones, and a palmar ligament located between the radius and the intermediate carpal bone. The approach to the middle carpal joint allowed visualization of the distal aspect of the radial, intermediate, and ulnar carpal bones, the proximal aspect of the fourth and fused second and third carpal bones and an interosseous ligament. The most lateral articular structures (lateral glenoid cavity of the distal radius, ulnar carpal and fourth carpal bones) were difficult to assess. Dorsal approaches to the antebrachiocarpal and middle carpal joints allowed visualization of most intra-articular dorsal structures in adult cattle. © Copyright 2016 by The American College of Veterinary Surgeons.

Are distal radius fracture classifications reproducible? Intra and interobserver agreement.

PubMed

Belloti, João Carlos; Tamaoki, Marcel Jun Sugawara; Franciozi, Carlos Eduardo da Silveira; Santos, João Baptista Gomes dos; Balbachevsky, Daniel; Chap Chap, Eduardo; Albertoni, Walter Manna; Faloppa, Flávio

2008-05-01

Various classification systems have been proposed for fractures of the distal radius, but the reliability of these classifications is seldom addressed. For a fracture classification to be useful, it must provide prognostic significance, interobserver reliability and intraobserver reproducibility. The aim here was to evaluate the intraobserver and interobserver agreement of distal radius fracture classifications. This was a validation study on interobserver and intraobserver reliability. It was developed in the Department of Orthopedics and Traumatology, Universidade Federal de São Paulo - Escola Paulista de Medicina. X-rays from 98 cases of displaced distal radius fracture were evaluated by five observers: one third-year orthopedic resident (R3), one sixth-year undergraduate medical student (UG6), one radiologist physician (XRP), one orthopedic trauma specialist (OT) and one orthopedic hand surgery specialist (OHS). The radiographs were classified on three different occasions (times T1, T2 and T3) using the Universal (Cooney), Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation (AO/ASIF), Frykman and Fernández classifications. The kappa coefficient (kappa) was applied to assess the degree of agreement. Among the three occasions, the highest mean intraobserver k was observed in the Universal classification (0.61), followed by Fernández (0.59), Frykman (0.55) and AO/ASIF (0.49). The interobserver agreement was unsatisfactory in all classifications. The Fernández classification showed the best agreement (0.44) and the worst was the Frykman classification (0.26). The low agreement levels observed in this study suggest that there is still no classification method with high reproducibility.

Are distal radius fractures due to fragility or to falls? A consecutive case-control study of bone mineral density, tendency to fall, risk factors for osteoporosis, and health-related quality of life.

PubMed

Nordvall, Helena; Glanberg-Persson, Gunhild; Lysholm, Jack

2007-04-01

A fracture of the distal radius is considered to indicate an increased risk of future fractures, especially a hip fracture. The main causes may be osteoporosis or a tendency to fall, separately or in combination. 93 women and 5 men with a recent radius fracture and the same number of controls were measured with a heel-DXL and asked to complete one questionnaire on their quality of life (SF-36), and one on risk factors. The mean T-score of the patients was -2.1, and for the controls it was -1.9 (p = 0.3). The patients aged over 64 years had a history of falling more often than the corresponding controls (p = 0.01), but there was no difference in T-score. By contrast, patients 45-64 years of age showed a non-significant, lower T-score (p = 0.09), but there was no difference concerning their history of falling. For all other risk factors, no differences were found between the patients and the controls. There were significant differences between the patients and the controls in some of the functions in the SF-36, due to the radius fracture. This study indicates that the underlying cause of a distal radius fracture may be different in patients aged 45-64 years and those who are more than 64 years old.

Probing Neutron-Skin Thickness of Unstable Nuclei with Total Reaction Cross Sections

NASA Astrophysics Data System (ADS)

Horiuchi, Wataru; Suzuki, Yasuyuki; Inakura, Tsunenori

We present our recent analysis of the total reaction cross sections, σR, of unstable nuclei and discuss their sensitivity to the neutron-skin thickness. The σR is calculated with the Glauber model using projectile densities obtained with the Skyrme-Hartree-Fock method on the three-dimensional coordinate space. We cover 91 nuclei of O, Ne, Mg, Si, S, Ca, and Ni isotopes. Defining a reaction radius, aR = √{σ R/π } , to characterize the nuclear size and target (proton or 12C) dependence, we see the 12C target probes the matter radius while the proton target is sensitive to the skin-thickness. We find an empirical formula for expressing aR with the point matter radius and the skin thickness, which can be used to determine the skin thickness.

[Distal fixation prosthesis for unstable intertrochanteric fractures in elderly patients: a mid-term follow-up study].

PubMed

Zhang, Zhan-feng; Min, Ji-kang; Zhong, Jian-ming; Wang, Dan

2016-06-01

To explore mid-term follow up results of distal fixation prosthesis in treating unstable intertrochanteric fractures in elderly patients. From May 2008 to March 2014,58 elderly patients with unstable intertrochanteric were treated with distal fixation prosthesis, among them, there were 15 males and 43 females aged from 75 to 87 years old with an average of 83.2 years old. Fracture were classified according to Evans classification, 39 cases were type I c and 19 cases were type I d. Surgical risk was evaluated before operation, 9 patients were performed total hip arthroplasty and 49 patients were performed prosthetic replacement hip joint function of patients with different age period, Evans classificaton, prothesis type, fixation method were evaluated respectively by using Harris score. Fifty-six patients were followed up from 13 to 36 months with an average of 21.6 months. Harris score was 83.51 ± 6.40, 5 cases got excellent results, 38 cases good and 13 cases moderate. Harris score of patients aged from 75 to 80 years old was 88.64 ± 2.35, 81.64 ± 6.40 in patients aged more than 80 years old, and had significant differences between two groups; Harris score in patients with type Evans I c was 83.64 ± 6.53, and 83.11 ± 6.08 in type Evans I d, while there was no significant differences between two groups. There was no obvious meaning in Harris score between patients with tension band (83.63 ± 6.15) and without tension band (82.41 ± 6.57). There was no significant meaning in Harris score between patients with normal distal fixation prosthesis (83.34 ± 6.43) and femoral moment reconstruction distal fixation prosthesis (83.92 ± 6.51). There was 1 patient occurred hip joint dislocation on the operative side and re-dislocation after manual reduction, then received open reduction. Two patients occurred femoral osteolysis without clinical symptoms, and treated conservative treatment. Artificial joint replacement for unstable intertrochanteric fractures in elderly patients, hip joint function in patients aged more than 80 years old is worse, while there was no obvious market effect in fracture classification, whether to use tension band and type of distal fixation prosthesis, moreover, proximal femoral osteolysis should be focused on.

Non-union in 3 of 15 osteotomies of the distal radius without bone graft

PubMed Central

Scheer, Johan H; Adolfsson, Lars E

2015-01-01

Background and purpose Open-wedge osteotomies of the distal radius create a void that is usually filled with either iliac crest bone graft or bone substitute. Previous studies have suggested that this is unnecessary. We investigated the safety of omitting the filling procedure. Patients and methods We included 15 patients with a dorsal malunion of a distal radius fracture. A palmar approach and angle-stable plates were used. The patients were followed until there was radiographic and clinical healing. Results Non-union occurred in 3 of the 15 patients. The study, which had been planned to include 25 patients, was then discontinued. 6 osteotomies created a trapezoid void (no cortical contact); 3 of these did not unite after the index procedure (p = 0.04), but did subsequently, after autogenous bone grafting. A trapezoid void was significantly associated with non-union (p = 0.04). Interpretation When a trapezoid defect is created, one should consider bone substitute or autogenous bone graft. This has been shown to be safe in other studies. PMID:25619425

Can the displacement of a conservatively treated distal radius fracture be predicted at the beginning of treatment?

PubMed Central

Einsiedel, T.; Freund, W.; Sander, S.; Trnavac, S.; Gebhard, F.

2008-01-01

The aim of this study was to investigate whether the final displacement of conservatively treated distal radius fractures can be predicted after primary reduction. We analysed the radiographic documents of 311 patients with a conservatively treated distal radius fracture at the time of injury, after reduction and after bony consolidation. We measured the dorsal angulation (DA), the radial angle (RA) and the radial shortening (RS) at each time point. The parameters were analysed separately for metaphyseally “stable” (A2, C1) and “unstable” (A3, C2, C3) fractures, according to the AO classification system. Spearman’s rank correlations and regression functions were determined for the analysis. The highest correlations were found for the DA between the time points ‘reduction’ and ‘complete healing’ (r = 0.75) and for the RA between the time points ‘reduction’ and ‘complete healing’ (r = 0.80). The DA and the RA after complete healing can be predicted from the regression functions. PMID:18504577

Impact of oral ibandronate 150 mg once monthly on bone structure and density in post-menopausal osteoporosis or osteopenia derived from in vivo μCT.

PubMed

Bock, Oliver; Börst, Hendrikje; Beller, Gisela; Armbrecht, Gabriele; Degner, Corina; Martus, Peter; Roth, Heinz-Jürgen; Felsenberg, Dieter

2012-01-01

The effect of ibandronate 150 mg/once monthly in the treatment of post-menopausal osteopenia and osteoporosis on bone micro-structure at the distal tibia and radius has not been considered to date. Seventy post-menopausal women with osteoporosis or osteopenia were recruited. All subjects received calcium and vitamin D supplementation and were randomized to either a group which took 150 mg ibandronate oral monthly or a placebo group over a 12-month period. μCT measures of the distal tibia and radius were conducted every three months, with DXA lumbar spine and hip measurements conducted only pre and post and serum markers of bone formation and resorption measured every 6 months. After 12-months no significant impact of ibandronate on the primary outcome measures bone-volume to tissue-volume and trabecular separation at the distal tibia (p≥0.15) was found. Further multiple regression analyses of the primary end-points indicated a significant effect favoring the ibandronate intervention (p=0.045). Analysis of secondary end-points showed greater increases in distal tibia cortical thickness, cortical density and total density (p≤0.043) with ibandronate and no significant effects at the distal radius, but greater increases of hip DXA-BMD and lumbar spine DXA-BMD (p≤0.017). Ibandronate use resulted in a marked reduction in bone turnover (p<0.001). While ibandronate resulted in greater mineralization of bone, this effect differed from one body region to another. There was some impact of ibandronate on bone structure (cortical thickness) at the distal tibia, but not on bone-volume to tissue-volume or trabecular separation. Copyright © 2011 Elsevier Inc. All rights reserved.

Non-axisymmetric annular curtain stability

NASA Astrophysics Data System (ADS)

Ahmed, Zahir U.; Khayat, Roger E.; Maissa, Philippe; Mathis, Christian

2013-08-01

A stability analysis of non-axisymmetric annular curtain is carried out for an axially moving viscous jet subject in surrounding viscous gas media. The effect of inertia, surface tension, gas-to-liquid density ratio, inner-to-outer radius ratio, and gas-to-liquid viscosity ratio on the stability of the jet is studied. In general, the axisymmetric disturbance is found to be the dominant mode. However, for small wavenumber, the non-axisymmetric mode is the most unstable mode and the one likely observed in reality. Inertia and the viscosity ratio for non-axisymmetric disturbances show a similar stability influence as observed for axisymmetric disturbances. The maximum growth rate in non-axisymmetric flow, interestingly, appears at very small wavenumber for all inertia levels. The dominant wavenumber increases (decreases) with inertia for non-axisymmetric (axisymmetric) flow. Gas-to-liquid density ratio, curvature effect, and surface tension, however, exhibit an opposite influence on growth rate compared to axisymmetric disturbances. Surface tension tends to stabilize the flow with reductions of the unstable wavenumber range and the maximum growth rate as well as the dominant wavenumber. The dominant wavenumber remains independent of viscosity ratio indicating the viscosity ratio increases the breakup length of the sheet with very little influence on the size of the drops. The range of unstable wavenumbers is affected only by curvature in axisymmetric flow, whereas all the stability parameters control the range of unstable wavenumbers in non-axisymmetric flow. Inertia and gas density increase the unstable wavenumber range, whereas the radius ratio, surface tension, and the viscosity ratio decrease the unstable wavenumber range. Neutral curves are plotted to separate the stable and unstable domains. Critical radius ratio decreases linearly and nonlinearly with the wavenumber for axisymmetric and non-axisymmetric disturbances, respectively. At smaller Weber numbers, a wider unstable domain is predicted for non-axisymmetric modes. For both axisymmetric and non-axisymmetric modes, the disturbance frequency is found to be the same and equal to the negative of axial wavenumber. Finally, comparison between theory and existing experiment leads to good qualitative agreement. A more accurate comparison is not possible given the difference in flow conditions.

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

Comparison of pQCT parameters between ulna and radius in retired elite gymnasts: the skeletal benefits associated with long-term gymnastics are bone- and site-specific.

PubMed

Ducher, G; Hill, B L; Angeli, T; Bass, S L; Eser, P

2009-01-01

To compare the skeletal benefits associated with gymnastics between ulna and radius. 19 retired artistic gymnasts, aged 18-36 years, were compared to 24 sedentary women. Bone mineral content (BMC), total and cortical bone area (ToA, CoA), trabecular and cortical volumetric density (TrD, CoD) and cortical thickness (CoTh) were measured by pQCT at the 4% and 66% forearm. At the 4% site, BMC and ToA were more than twice greater at the radius than ulna whereas at the 66% site, BMC, ToA, CoA, CoTh and SSIpol were 20 to 51% greater at the ulna than radius in both groups (p<0.0001). At the 4% site, the skeletal benefits in BMC of the retired gymnasts over the non-gymnasts were 1.9 times greater at the radius than ulna (p<0.001), with enlarged bone size at the distal radius only. In contrast, the skeletal benefits at the 66% site were twice greater at the ulna than radius for BMC and CoA (p<0.01). Whereas the skeletal benefits associated with long-term gymnastics were greater at the radius than ulna in the distal forearm, the reverse was found in the proximal forearm, suggesting both bones should be analysed when investigating forearm strength.

Occupational therapy and Colles' fractures.

PubMed

Christensen, O M; Kunov, A; Hansen, F F; Christiansen, T C; Krasheninnikoff, M

2001-01-01

In this randomized trial, we enrolled 30 patients treated for a distal radius Colles' type fracture. The fractures were reduced if necessary and fixed in a below-elbow plaster cast for 5 weeks. One group consisting of 14 patients received instructions for shoulder; elbow and finger exercise and the other group consisting of 16 patients had occupational therapy. At 5 weeks, 3 and 9 months we measured the functional scores. There were no statistically significant differences between the groups at any time. It seems that for non-surgically treated patients with a distal radius fracture only instructions are necessary.

The Minimum Clinically Important Difference of the Patient-rated Wrist Evaluation Score for Patients With Distal Radius Fractures.

PubMed

Walenkamp, Monique M J; de Muinck Keizer, Robert-Jan; Goslings, J Carel; Vos, Lara M; Rosenwasser, Melvin P; Schep, Niels W L

2015-10-01

The Patient-rated Wrist Evaluation (PRWE) is a commonly used instrument in upper extremity surgery and in research. However, to recognize a treatment effect expressed as a change in PRWE, it is important to be aware of the minimum clinically important difference (MCID) and the minimum detectable change (MDC). The MCID of an outcome tool like the PRWE is defined as the smallest change in a score that is likely to be appreciated by a patient as an important change, while the MDC is defined as the smallest amount of change that can be detected by an outcome measure. A numerical change in score that is less than the MCID, even when statistically significant, does not represent a true clinically relevant change. To our knowledge, the MCID and MDC of the PRWE have not been determined in patients with distal radius fractures. We asked: (1) What is the MCID of the PRWE score for patients with distal radius fractures? (2) What is the MDC of the PRWE? Our prospective cohort study included 102 patients with a distal radius fracture and a median age of 59 years (interquartile range [IQR], 48-66 years). All patients completed the PRWE questionnaire during each of two separate visits. At the second visit, patients were asked to indicate the degree of clinical change they appreciated since the previous visit. Accordingly, patients were categorized in two groups: (1) minimally improved or (2) no change. The groups were used to anchor the changes observed in the PRWE score to patients' perspectives of what was clinically important. We determined the MCID using an anchor-based receiver operator characteristic method. In this context, the change in the PRWE score was considered a diagnostic test, and the anchor (minimally improved or no change as noted by the patients from visit to visit) was the gold standard. The optimal receiver operator characteristic cutoff point calculated with the Youden index reflected the value of the MCID. In our study, the MCID of the PRWE was 11.5 points. The area under the curve was 0.54 (95% CI, 0.37-0.70) for the pain subscale and 0.71 (95% CI, 0.57-0.85) for the function subscale. We determined the MDC to be 11.0 points. We determined the MCID of the PRWE score for patients with distal radius fractures using the anchor-based approach and verified that the MDC of the PRWE was sufficiently small to detect our MCID. We recommend using an improvement on the PRWE of more than 11.5 points as the smallest clinically relevant difference when evaluating the effects of treatments and when performing sample-size calculations on studies of distal radius fractures.

[Locked volar plating for complex distal radius fractures: maintaining radial length].

PubMed

Jeudy, J; Pernin, J; Cronier, P; Talha, A; Massin, P

2007-09-01

Maintaining radial length, likely to be the main challenge in the treatment of complex distal radius fractures, is necessary for complete grip-strength and pro-supination range recovery. In spite of frequent secondary displacements, bridging external-fixation has remained the reference method, either isolated or in association with additional percutaneous pins or volar plating. Also, there seems to be a relation between algodystrophy and the duration of traction applied on the radio-carpal joint. Fixed-angle volar plating offers the advantage of maintaining the reduction until fracture healing, without bridging the joint. In a prospective study, forty-three consecutive fractures of the distal radius with a positivated ulnar variance were treated with open reduction and fixed-angle volar plating. Results were assessed with special attention to the radial length and angulation obtained and maintained throughout treatment, based on repeated measurements of the ulnar variance and radial angulation in the first six months postoperatively. The correction of the ulnar variance was maintained until complete recovery, independently of initial metaphyseal comminution, and of the amount of radial length gained at reduction. Only 3 patients lost more than 1 mm of radial length after reduction. The posterior tilt of the distal radial epiphysis was incompletely reduced in 13 cases, whereas reduction was partially lost in 6 elderly osteoporotic female patients. There was 8 articular malunions, all of them less than 2 mm. Secondary displacements were found to be related to a deficient locking technique. Eight patients developed an algodystropy. The risk factors for algodystrophy were articular malunion, associated posterior pining, and associated lesions of the ipsilateral upper limb. Provided that the locking technique was correct, this type of fixation appeared efficient in maintaining the radial length in complex fractures of the distal radius. The main challenge remains the reduction of displaced articular fractures. Based on these results, it is not possible to conclude that this method is superior to external fixation.

Reproducibility of Direct Quantitative Measures of Cortical Bone Micro-architecture of the Distal Radius and Tibia by HR-pQCT

PubMed Central

Burghardt, Andrew J.; Buie, Helen R.; Laib, Andres; Majumdar, Sharmila; Boyd, Steven K.

2010-01-01

Quantitative cortical micro-architectural endpoints are important for understanding structure-function relations in the context of fracture risk and therapeutic efficacy. This technique study details new image-processing methods to automatically segment and directly quantify cortical density, geometry, and micro-architecture from HR-pQCT images of the distal radius and tibia. An automated segmentation technique was developed to identify the periosteal and endosteal margins of the distal radius and tibia, and detect intra-cortical pore space morphologically consistent with Haversian canals. The reproducibility of direct quantitative cortical bone indices based on this method was assessed in a pooled dataset of 56 subjects with two repeat acquisitions for each site. The in vivo precision error was characterized using root mean square coefficient of variation (RMSCV%) from which, the least significant change (LSC) was calculated. Bland-Altman plots were used to characterize bias in the precision estimates. The reproducibility of cortical density and cross-sectional area measures was high (RMSCV <1% and <1.5%, respectively) with good agreement between young and elder medians. The LSC for cortical porosity (Ct.Po) was somewhat smaller in the radius (0.58%) compared with the distal tibia (0.84%) and significantly different between young and elder medians in the distal tibia (LSC: 0.75% vs. 0.92%; p<0.001). The LSC for pore diameter and distribution (Po.Dm and Po.Dm.SD) ranged between 15 and 23μm. Bland-Altman analysis revealed moderate bias for integral measures of area and volume, but not density nor microarchitecture. This study indicates HR-pQCT measures of cortical bone density and architecture can be measured in vivo with high reproducibility and limited bias across a biologically relevant range of values. The results of this study provide informative data for the design of future clinical studies of bone quality. PMID:20561906

Follicle-stimulating hormone and bioavailable estradiol are less important than weight and race in determining bone density in younger postmenopausal women

PubMed Central

Preisser, J. S.; Hammett-Stabler, C. A.; Renner, J. B.; Rubin, J.

2011-01-01

Summary The association between follicle-stimulating hormone (FSH) and bone density was tested in 111 postmenopausal women aged 50–64 years. In the multivariable analysis, weight and race were important determinants of bone mineral density. FSH, bioavailable estradiol, and other hormonal variables did not show statistically significant associations with bone density at any site. Introduction FSH has been associated with bone density loss in animal models and longitudinal studies of women. Most of these analyses have not considered the effect of weight or race. Methods We tested the association between FSH and bone density in younger postmenopausal women, adjusting for patient-related factors. In 111 postmenopausal women aged 50–64 years, areal bone mineral density (BMD) was measured at the lumbar spine, femoral neck, total hip, and distal radius using dual-energy X-ray absorptiometry, and volumetric BMD was measured at the distal radius using peripheral quantitative computed tomography (pQCT). Height, weight, osteoporosis risk factors, and serum hormonal factors were assessed. Results FSH inversely correlated with weight, bioavailable estradiol, areal BMD at the lumbar spine and hip, and volumetric BMD at the ultradistal radius. In the multivariable analysis, no hormonal variable showed a statistically significant association with areal BMD at any site. Weight was independently associated with BMD at all central sites (p<0.001), but not with BMD or pQCT measures at the distal radius. Race was independently associated with areal BMD at all sites (p≤0.008) and with cortical area at the 33% distal radius (p=0.004). Conclusions Correlations between FSH and bioavailable estradiol and BMD did not persist after adjustment for weight and race in younger postmenopausal women. Weight and race were more important determinants of bone density and should be included in analyses of hormonal influences on bone. PMID:21125395

Boundary Between Stable and Unstable Regimes of Accretion

NASA Astrophysics Data System (ADS)

Blinova, A. A.; Lovelace, R. V. E.; Romanova, M. M.

2014-01-01

We investigated the boundary between stable and unstable regimes of accretion and its dependence on different parameters. Simulations were performed using a "cubed sphere" code with high grid resolution (244 grid points in the azimuthal direction), which is twice as high as that used in our earlier studies. We chose a very low viscosity value, with alpha-parameter α=0.02. We observed from the simulations that the boundary strongly depends on the ratio between magnetospheric radius rm (where the magnetic stress in the magnetosphere matches the matter stress in the disk) and corotation radius rcor (where the Keplerian velocity in the disk is equal to the angular velocity of the star). For a small misalignment angle of the dipole field, Θ = 5°, accretion is unstable if rcor/rm> 1.35, and is stable otherwise. In cases of a larger misalignment angle of the dipole, Θ = 20°, instability occurs at slightly larger values, rcor/rm> 1.41

[Progress in diagnosis and treatment of distal tibiofibular syndesmosis injury].

PubMed

Liu, Xiang; Yu, Guangrong

2012-05-01

To review the progress in the diagnosis and treatment of distal tibiofibular syndesmosis injury. Different kinds of documents were widely collected, current developments of the diagnosis and treatment of distal tibiofibular syndesmosis injury were summarized. The disease history (damage mechanism), clinical examination, and imaging examination (X-ray, CT scan, and MRI) can assist the diagnosis of distal tibiofibular syndesmosis injury. Patients with unstable distal tibiofibular syndesmosis injury needs active surgery treatment, and the principle is anatomical reduction and fixation so as to avoid the instability of the ankle joint, long-term chronic pain, and traumatic arthritis. The diagnosis of distal tibiofibular syndesmosis injury is still lack of specific quantitative parameters, so clinical study for large sample is needed to explicit the effectiveness.

Management of a Complex, Multioperated Intra-Articular Distal Radius Fracture

PubMed Central

Giwa, Lolade; Spacey, Kate; Packer, Greg

2015-01-01

Background Intra-articular distal radius fractures can have many complications, including radiocarpal osteoarthritis and distal radioulnar joint (DRUJ) dysfunction leading to pain and restricted wrist function. Case Description We describe the case of a 38-year-old patient who sustained a left distal radius intra-articular fracture, which was treated with volar plating. She developed pain from the radiocarpal joint as a result of intra-articular malunion and was listed for total wrist fusion. On the day of surgery this was converted to a Darrach procedure for minor DRUJ symptoms. This resulted in pain from the DRUJ as a result of instability, in addition to persisting radiocarpal arthritis pain. Due to her subsequent poor wrist function, she presented to the authors and underwent DRUJ arthroplasty with a proximally placed Scheker prosthesis to deal with her DRUJ symptoms and, later, a KinematX radiocarpal hemiarthroplasty for her radiocarpal symptoms. She remains happy with her outcome at 36-month follow-up. Literature Review The complications of the Darrach procedure include painful radioulnar convergence and wrist instability. The Scheker prosthesis allows restoration of stability of the DRUJ with good outcomes and 100% 5-year survival in one series. Sparing the midcarpal joint, the KinematX hemiarthroplasty allows preservation of the dart thrower's motion arc, which is key in many complex wrist movements and functions. Clinical Relevance This case highlights the negative consequences of distal ulna resection and shows both the Scheker and KinematX prostheses as viable, effective means to restore function to young, active patients with posttraumatic radiocarpal arthritis and/or instability. PMID:26261743

Arthroscopic knotless anchor repair of triangular fibrocartilage in distal radius fracture.

PubMed

García-Ruano, Á A; Najarro-Cid, F; Jiménez-Martín, A; Gómez de los Infantes-Troncoso, J G; Sicre-González, M

2015-01-01

Lesions of triangular fibrocartilage (TFC) are associated with distal radioulnar joint instability. Arthroscopic treatment of these lesions improves functional outcome of affected patients. The aim of the present work is to evaluate functional and occupational outcome of TCF repair using an arthroscopic knotless anchor device in patients with associated distal radius fracture. An observational, descriptive study was carried out between November 2011 and January 2014 including 21 patients with distal radius fracture and Palmer 1B lesions of TCF (Atzei class 2 and 3) that were treated by arthroscopic knotless anchor (PopLok® 2,8mm, ConMed, USA). Mean follow-up was 18 months. Functional (Mayo Wrist Score) and occupational outcome results were analyzed. Mean age of the group was 43.0±8.8 years, with 19% of the patients being female. There was an associated scapholunate lesion in 5 cases. Functional results reached a mean of 83.4±16.1 points onMayo Wrist Score. Mean sick-leave time was 153.16±48.5 days. Complete occupational reintegration was reached in 89.5% of cases. There were no postoperative complications. Arthroscopic knotless anchor repair of 1B TFC tears is a minimally invasive method of treatment that improves tension of fixation, avoiding subsequent loosen, in our experience, with few complications and good functional and occupational results. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

Three-dimensional computer simulation of radiostereometric analysis (RSA) in distal radius fractures.

PubMed

Madanat, Rami; Moritz, Niko; Aro, Hannu T

2007-01-01

Physical phantom models have conventionally been used to determine the accuracy and precision of radiostereometric analysis (RSA) in various orthopaedic applications. Using a phantom model of a fracture of the distal radius it has previously been shown that RSA is a highly accurate and precise method for measuring both translation and rotation in three-dimensions (3-D). The main shortcoming of a physical phantom model is its inability to mimic complex 3-D motion. The goal of this study was to create a realistic computer model for preoperative planning of RSA studies and to test the accuracy of RSA in measuring complex movements in fractures of the distal radius using this new model. The 3-D computer model was created from a set of tomographic scans. The simulation of the radiographic imaging was performed using ray-tracing software (POV-Ray). RSA measurements were performed according to standard protocol. Using a two-part fracture model (AO/ASIF type A2), it was found that for simple movements in one axis, translations in the range of 25microm-2mm could be measured with an accuracy of +/-2microm. Rotations ranging from 16 degrees to 2 degrees could be measured with an accuracy of +/-0.015 degrees . Using a three-part fracture model the corresponding values of accuracy were found to be +/-4microm and +/-0.031 degrees for translation and rotation, respectively. For complex 3-D motion in a three-part fracture model (AO/ASIF type C1) the accuracy was +/-6microm for translation and +/-0.120 degrees for rotation. The use of 3-D computer modelling can provide a method for preoperative planning of RSA studies in complex fractures of the distal radius and in other clinical situations in which the RSA method is applicable.

Distal radius geometry and skeletal strength indices after peripubertal artistic gymnastics.

PubMed

Dowthwaite, J N; Scerpella, T A

2011-01-01

Development of optimal skeletal strength should decrease adult bone fragility. Nongymnasts (NON): were compared with girls exposed to gymnastics during growth (EX/GYM: ), using peripheral quantitative computed tomography (pQCT) to evaluate postmenarcheal bone geometry, density, and strength. Pre- and perimenarcheal gymnastic loading yields advantages in indices of postmenarcheal bone geometry and skeletal strength. Two prior studies using pQCT have reported bone density and size advantages in Tanner I/II gymnasts, but none describe gymnasts' bone properties later in adolescence. The current study used pQCT to evaluate whether girls exposed to gymnastics during late childhood growth and perimenarcheal growth exhibited greater indices of distal radius geometry, density, and skeletal strength. Postmenarcheal subjects underwent 4% and 33% distal radius pQCT scans, yielding: 1) vBMD and cross-sectional areas (CSA) (total bone, compartments); 2) polar strength-strain index; 3) index of structural strength in axial compression. Output was compared for EX/GYM: vs. NON: , adjusting for gynecological age and stature (maturity and body size), reporting means, standard errors, and significance. Sixteen postmenarcheal EX/GYM: (age 16.7 years; gynecological age 3.4 years) and 13 NON: (age 16.2 years; gynecological age 3.6 years) were evaluated. At both diaphysis and metaphysis, EX/GYM: exhibited greater CSA and bone strength indices than NON; EX/GYM: exhibited 79% larger intramedullary CSA than NON: (p < 0.05). EX/GYM: had significantly higher 4% trabecular vBMD; differences were not detected for 4% total vBMD and 33% cortical vBMD. Following pre-/perimenarcheal gymnastic exposure, relative to nongymnasts, postmenarcheal EX/GYM: demonstrated greater indices of distal radius geometry and skeletal strength (metaphysis and diaphysis) with greater metaphyseal trabecular vBMD; larger intramedullary cavity size was particularly striking.

Distal radius geometry and skeletal strength indices after peripubertal artistic gymnastics

PubMed Central

Scerpella, T. A.

2011-01-01

Summary Development of optimal skeletal strength should decrease adult bone fragility. Nongymnasts (NON) were compared with girls exposed to gymnastics during growth (EX/GYM), using peripheral quantitative computed tomography (pQCT) to evaluate postmenarcheal bone geometry, density, and strength. Pre- and perimenarcheal gymnastic loading yields advantages in indices of postmenarcheal bone geometry and skeletal strength. Introduction Two prior studies using pQCT have reported bone density and size advantages in Tanner I/II gymnasts, but none describe gymnasts’ bone properties later in adolescence. The current study used pQCT to evaluate whether girls exposed to gymnastics during late childhood growth and perimenarcheal growth exhibited greater indices of distal radius geometry, density, and skeletal strength. Methods Postmenarcheal subjects underwent 4% and 33% distal radius pQCT scans, yielding: 1) vBMD and cross-sectional areas (CSA) (total bone, compartments); 2) polar strength-strain index; 3) index of structural strength in axial compression. Output was compared for EX/GYM vs. NON, adjusting for gynecological age and stature (maturity and body size), reporting means, standard errors, and significance. Results Sixteen postmenarcheal EX/GYM (age 16.7 years; gynecological age 3.4 years) and 13 NON (age 16.2 years; gynecological age 3.6 years) were evaluated. At both diaphysis and metaphysis, EX/GYM exhibited greater CSA and bone strength indices than NON; EX/GYM exhibited 79% larger intramedullary CSA than NON (p<0.05). EX/GYM had significantly higher 4% trabecular vBMD; differences were not detected for 4% total vBMD and 33% cortical vBMD. Conclusions Following pre-/perimenarcheal gymnastic exposure, relative to nongymnasts, postmenarcheal EX/GYM demonstrated greater indices of distal radius geometry and skeletal strength (metaphysis and diaphysis) with greater metaphyseal trabecular vBMD; larger intramedullary cavity size was particularly striking. PMID:20419293

MRI of bone marrow in the distal radius: in vivo precision of effective transverse relaxation times

NASA Technical Reports Server (NTRS)

Grampp, S.; Majumdar, S.; Jergas, M.; Lang, P.; Gies, A.; Genant, H. K.

1995-01-01

The effective transverse relaxation time T2* is influenced by the presence of trabecular bone, and can potentially provide a measure of bone density as well as bone structure. We determined the in vivo precision of T2* in repeated bone marrow measurements. The T2* measurements of the bone marrow of the distal radius were performed twice within 2 weeks in six healthy young volunteers using a modified water-presaturated 3D Gradient-Recalled Acquisition at Steady State (GRASS) sequence with TE 7, 10, 12, 20, and 30; TR 67; flip angle (FA) 90 degrees. An axial volume covering a length of 5.6 cm in the distal radius was measured. Regions of interest (ROIs) were determined manually and consisted of the entire trabecular bone cross-section extending proximally from the radial subchondral endplate. Reproducibility of T2* and area measurements was expressed as the absolute precision error (standard deviation [SD] in ms or mm2) or as the relative precision error (SD/mean x 100, or coefficient of variation [CV] in %) between the two-point measurements. Short-term precision of T2* and area measurements varied depending on section thickness and location of the ROI in the distal radius. Absolute precision errors for T2* times were between 1.3 and 2.9 ms (relative precision errors 3.8-9.5 %) and for area measurements between 20 and 55 mm2 (relative precision errors 5.1-16.4%). This MR technique for quantitative assessment of trabecular bone density showed reasonable reproducibility in vivo and is a promising future tool for the assessment of osteoporosis.

Precision of pQCT-measured total, trabecular and cortical bone area, content, density and estimated bone strength in children

PubMed Central

Duff, W.R.D.; Björkman, K.M.; Kawalilak, C.E.; Kehrig, A.M.; Wiebe, S.; Kontulainen, S.

2017-01-01

Objectives: To define pQCT precision errors, least-significant-changes, and identify associated factors for bone outcomes at the radius and tibia in children. Methods: We obtained duplicate radius and tibia pQCT scans from 35 children (8-14yrs). We report root-mean-squared coefficient of variation (CV%RMS) and 95% limits-of-agreement to characterize repeatability across scan quality and least-significant-changes for bone outcomes at distal (total and trabecular area, content and density; and compressive bone strength) and shaft sites (total area and content; cortical area content, density and thickness; and torsional bone strength). We used Spearman’s rho to identify associations between CV% and time between measurements, child’s age or anthropometrics. Results: After excluding unanalyzable scans (6-10% of scans per bone site), CV%RMS ranged from 4% (total density) to 19% (trabecular content) at the distal radius, 4% (cortical content) to 8% (cortical thickness) at the radius shaft, 2% (total density) to 14% (trabecular content) at the distal tibia and from 2% (cortical content) to 6% (bone strength) at the tibia shaft. Precision errors were within 95% limits-of-agreement across scan quality. Age was associated (rho -0.4 to -0.5, p <0.05) with CV% at the tibia. Conclusion: Bone density outcomes and cortical bone properties appeared most precise (CV%RMS <5%) in children. PMID:28574412

[Pedicled vascularized bone grafts from the dorsum of the distal radius for treatment of scaphoid nonunions].

PubMed

Sauerbier, Michael; Bishop, Allen T; Ofer, Nina

2009-11-01

Bony healing and reconstruction of the scaphoid with use of a reverse-flow pedicle vascularized bone graft from the dorsal aspect of the distal radius. Revitalization of the proximal fragment in case of avascular necrosis. Scaphoid nonunion, especially of the proximal pole. Nonunion after failed attempts of autogenous nonvascularized bone grafting. Avascular necrosis of the scaphoid (Preiser's disease). Avascular osteonecrosis of other carpal bones (i.e., Kienböck's disease stage II and IIIa). However, these will not be addressed in this paper. Advance carpal collapse (SNAC [scaphoid nonunion advanced collapse] wrist stage II and III). Avascular necrosis with broken proximal pole of the scaphoid. Malformation, disease or previous injury of the vascular system. Reconstruction of the scaphoid by interposition of a vascularized bone graft from the dorsum of the distal radius, where several vascularized bone grafts can be harvested, and fixation by a scaphoid screw. Management Immobilization for 6 weeks in a forearm cast including the first phalanx of the thumb. 48 scaphoid nonunions were treated with 1,2-ICSRA-based (intercompartmental supraretinacular artery) vascularized bone grafts: 34 scaphoid nonunions went on to union at an average of 15.6 weeks after surgery.

[APPLICATION OF BUTTERFLY SHAPED LOCKING COMPRESSION PLATE IN COMPLEX DISTAL RADIUS FRACTURES].

PubMed

Jiang, Zongyuan; Ma, Tao; Xia, Jiang; Hu, Caizhi; Xu, Lei

2014-06-01

To investigate the effectiveness of butterfly shaped locking compression plate for the treatment of complex distal radius fractures. Between June 2011 and January 2013, 20 cases of complex distal radius fractures were treated with butterfly shaped locking compression plate fixation. There were 11 males and 9 females with an average age of 54 years (range, 25-75 years). Injury was caused by falling in 10 cases, by traffic accident in 7 cases, and by falling from height in 3 cases. All of fractures were closed. According to AO classification system, there were 8 cases of type C1, 8 cases of type C2, and 4 cases of type C3. Of them, 9 cases had radial styloid process fracture, 4 cases had sigmoid notch fracture, and 7 cases had both radial styloid process fracture and sigmoid notch fracture. The mean interval between injury and operation was 5.2 days (range, 3-15 days). All incisions healed by first intention; no complications of infection and necrosis occurred. All cases were followed up 14 months on average (range, 10-22 months). All factures healed after 9.3 weeks on average (range, 6-11 weeks). No complications such as displacement of fracture, joint surface subsidence, shortening of the radius, and carpal tunnel syndrome were found during follow-up. At last follow-up, the mean palmar tilt angle was 10.2° (range, 7-15°), and the mean ulnar deviation angle was 21.8° (range, 17-24°). The mean range of motion of the wrist was 45.3° (range, 35-68°) in dorsal extension, 53.5° (range, 40-78°) in palmar flexion, 19.8° (range, 12-27°) in radial inclination, 26.6° (range, 18-31°) in ulnar inclination, 70.2° (range, 45-90°) in pronation, and 68.4° (range, 25-88°) in supination. According to the Dienst scoring system, the results were excellent in 8 cases, good in 10 cases, and fair in 2 cases, and the excellent and good rate was 90%. Treatment of complex distal radius fractures with butterfly shaped locking compression plate can reconstruct normal anatomic structures, especially for radial styloid process and sigmoid notch fractures, and it can get good functional recovery of the wrist and the distal radioulnar joint.

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 fixation, this trial found no difference in functional outcome in patients with dorsally displaced fractures of the distal radius treated with Kirschner wires or volar locking plates. Kirschner wire fixation, however, is cheaper and quicker to perform. Trial registration Current Controlled Trials ISCRTN 31379280. UKCRN 8956. PMID:25096595

Surgery versus conservative treatment in patients with type A distal radius fractures, a randomized controlled trial

PubMed Central

2014-01-01

Background Fractures of the distal radius are common and account for an estimated 17% of all fractures diagnosed. Two-thirds of these fractures are displaced and require reduction. Although distal radius fractures, especially extra-articular fractures, are considered to be relatively harmless, inadequate treatment may result in impaired function of the wrist. Initial treatment according to Dutch guidelines consists of closed reduction and plaster immobilisation. If fracture redisplacement occurs, surgical treatment is recommended. Recently, the use of volar locking plates has become more popular. The aim of this study is to compare the functional outcome following surgical reduction and fixation with a volar locking plate with the functional outcome following closed reduction and plaster immobilisation in patients with displaced extra-articular distal radius fractures. Design This single blinded randomised controlled trial will randomise between open reduction and internal fixation with a volar locking plate (intervention group) and closed reduction followed by plaster immobilisation (control group). The study population will consist of all consecutive adult patients who are diagnosed with a displaced extra-articular distal radius fracture, which has been adequately reduced at the Emergency Department. The primary outcome (functional outcome) will be assessed by means of the Disability Arm Shoulder Hand Score (DASH). Secondary outcomes comprise the Patient-Rated Wrist Evaluation score (PRWE), quality of life, pain, range of motion, radiological parameters, complications and cross-overs. Since the treatment allocated involves a surgical procedure, randomisation status will not be blinded. However, the researcher assessing the outcome at one year will be unaware of the treatment allocation. In total, 90 patients will be included and this trial will require an estimated time of two years to complete and will be conducted in the Academic Medical Centre Amsterdam and its partners of the regional trauma care network. Dicussion Ideally, patients would be randomised before any kind of treatment has been commenced. However, we deem it not patient-friendly to approach possible participants before adequate reduction has been obtained. Trial registration This study is registered at the Netherlands Trial Register (NTR3113) and was granted permission by the Medical Ethical Review Committee of the Academic Medical Centre on 01-10-2012. PMID:24642190

Instability of a rotating liquid ring

NASA Astrophysics Data System (ADS)

Zhao, Sicheng; Tao, Jianjun

2013-09-01

It is shown numerically that a rotating inviscid liquid ring has a temporally oscillating state, where the radius of the ring varies periodically because of the competition between the centrifugal force and the centripetal force caused by the surface tension. Stability analysis reveals that an enlarging or shrinking ring is unstable to a varicose-type mode, which is affected by both the radial velocity and the radius ratio between the cross section and the ring. Furthermore, uniform rotation of a ring leads to a traveling unstable mode, whose frequency is determined by a simple sinuous mode, while the surface shape is modulated by the varicose mode and twisted by the rotation-induced Coriolis force.

Instability of a rotating liquid ring.

PubMed

Zhao, Sicheng; Tao, Jianjun

2013-09-01

It is shown numerically that a rotating inviscid liquid ring has a temporally oscillating state, where the radius of the ring varies periodically because of the competition between the centrifugal force and the centripetal force caused by the surface tension. Stability analysis reveals that an enlarging or shrinking ring is unstable to a varicose-type mode, which is affected by both the radial velocity and the radius ratio between the cross section and the ring. Furthermore, uniform rotation of a ring leads to a traveling unstable mode, whose frequency is determined by a simple sinuous mode, while the surface shape is modulated by the varicose mode and twisted by the rotation-induced Coriolis force.

Evaluation of an Image-Based Tool to Examine the Effect of Fracture Alignment and Joint Congruency on Outcomes after Wrist Fracture.

PubMed

Lalone, Emily A; Grewal, Ruby; King, Graham W; MacDermid, Joy C

2015-01-01

Some mal-alignment of the wrist occurs in up to 71% of patients following a distal radius fracture. A multiple case study was used to provide proof of principle of an image-based technique to investigate the evolution and impact of post-traumatic joint changes at the distal radioulnar joint. Participants who had a unilateral distal radius fracture who previously participated in a prospective study were recruited from a single tertiary hand center. Long term follow-up measures of pain, disability, range of motion and radiographic alignment were obtained and compared to joint congruency measures. The inter-bone distance, a measure of joint congruency was quantified from reconstructed CT bone models of the distal radius and ulna and the clinical outcome was quantified using the patient rated wrist evaluation. In all four cases, acceptable post-reduction alignment and minimal pain/disability at 1-year suggested good clinical outcomes. However, 10 years following injury, 3 out of 4 patients had radiographic signs of degenerative changes occurring in their injured wrist (distal radioulnar joint/radio-carpal joint). Proximity maps displaying inter-bone distances showed asymmetrical congruency between wrists in these three patients. The 10-year PRWE (patient rated wrist evaluation) varied from 4 to 60, with 3 reporting minimal pain/disability and one experiencing high pain/disability. These illustrative cases demonstrate long-term joint damage post-fracture is common and occurs despite positive short-term clinical outcomes. Imaging and functional outcomes are not necessarily correlated. A novel congruency measure provides an indicator of the overall impact of joint mal-alignment that can be used to determine predictors of post-traumatic arthritis and is viable for clinical or large cohort studies.

Does formal education and training of staff reduce the operation rate for fractures of the distal radius?

PubMed

McDonald, Kyle; Murphy, Lynn; Gallagher, Brendan; Eames, Niall

2013-12-01

Fractures of the distal radius are one of the most common extremity fractures, and operation rates are increasing. Staff within our unit felt that formal teaching, particularly of new medical staff, with regards to fracture reduction and appropriate cast application could result in a reduction in operation rates. Retrospective data was extracted from FORD (Fracture Outcome and Research Database), including: number of fractures, number of fractures undergoing ORIF, fracture configuration, patient demographics, and mechanism of injury. All patients undergoing ORIF had their radiographs assessed by two separate reviewers. Information regarding adequate fracture reduction, adequate cast application (using Gap Index), and appropriate plaster cast moulding was recorded. Formal teaching was then given to the next group of medical staff rotating through the unit, and the same data was collected prospectively for that six-month period. Exclusion criteria included bilateral injuries, and polytrauma patients. A total of 1623 distal radial fractures were treated in our unit over the 12-month period, with 71 undergoing ORIF in the first 6 months and 39 in the second 6 months, this was statistically significant (p = 0.0009). Our study found that formal teaching and education significantly reduced the operation rate for distal radial fractures. This effect was most significant for extra-articular, dorsally angulated fractures of the distal radius. Our study proves that just 1 h of basic training at the beginning of an attachment can have significant benefits to both the unit and, more importantly, the patients. Copyright © 2013 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Vertebral deformities and fractures are associated with MRI and pQCT measures obtained at the distal tibia and radius of postmenopausal women

PubMed Central

Rajapakse, C. S.; Phillips, E. A.; Sun, W.; Wald, M. J.; Magland, J. F.; Snyder, P. J.; Wehrli, F. W.

2016-01-01

Summary We investigated the association of postmenopausal vertebral deformities and fractures with bone parameters derived from distal extremities using MRI and pQCT. Distal extremity measures showed variable degrees of association with vertebral deformities and fractures, highlighting the systemic nature of postmenopausal bone loss. Introduction Prevalent vertebral deformities and fractures are known to predict incident further fractures. However, the association of distal extremity measures and vertebral deformities in postmenopausal women has not been fully established. Methods This study involved 98 postmenopausal women (age range 60–88 years, mean 70 years) with DXA BMD T-scores at either the hip or spine in the range of −1.5 to −3.5. Wedge, biconcavity, and crush deformities were computed on the basis of spine MRI. Vertebral fractures were assessed using Eastell's criterion. Distal tibia and radius stiffness was computed using MRI-based finite element analysis. BMD at the distal extremities were obtained using pQCT. Results Several distal extremity MRI and pQCT measures showed negative association with vertebral deformity on the basis of single parameter correlation (r up to 0.67) and two-parameter regression (r up to 0.76) models involving MRI stiffness and pQCT BMD. Subjects who had at least one prevalent vertebral fracture showed decreased MRI stiffness (up to 17.9 %) and pQCT density (up to 34.2 %) at the distal extremities compared to the non-fracture group. DXA lumbar spine BMD T-score was not associated with vertebral deformities. Conclusions The association between vertebral deformities and distal extremity measures supports the notion of postmenopausal osteoporosis as a systemic phenomenon. PMID:24221453

Incidence of Treatment for Infection of Buried Versus Exposed Kirschner Wires in Phalangeal, Metacarpal, and Distal Radial Fractures.

PubMed

Ridley, Taylor J; Freking, Will; Erickson, Lauren O; Ward, Christina Marie

2017-07-01

To determine whether there is a difference in the incidence of infection between exposed and buried K-wires when used to treat phalangeal, metacarpal, and distal radius fractures. We conducted a retrospective review identifying all patients aged greater than 16 years who underwent fixation of phalangeal, metacarpal, or distal radius fractures with K-wires between 2007 and 2015. We recorded patient demographic data, fracture location, number of K-wires used, whether K-wires were buried or left exposed, and duration of K-wire placement. A total of 695 patients met inclusion criteria. Surgeons buried K-wires in 207 patients and left K-wires exposed in 488. Infections occurred more frequently in exposed K-wire cases than in buried K-wire ones. Subgroup analysis based on fracture location revealed a significantly increased risk of being treated for infection when exposed K-wires were used for metacarpal fractures. Patients with exposed K-wires for fixation of phalangeal, metacarpal, or distal radius fractures were more likely to be treated for a pin-site infection than those with K-wires buried beneath the skin. Metacarpal fractures treated with exposed K-wires were 2 times more likely to be treated for a pin-site infection (17.6% of exposed K wire cases vs 8.7% of buried K wire cases). Therapeutic IV. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

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

PubMed

Cisneros, Luis Natera; Reiriz, Juan Sarasquete

2017-04-01

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

A rare combined injury of dorsal fracture-dislocation of four carpometacarpal joints and trapezium, trapezoid and distal radius bone fractures.

PubMed

Touloupakis, Georgios; Stuflesser, Wilfried; Antonini, Guido; Ferrara, Fabrizio; Crippa, Cornelio; Lettera, Maria Gabriella

2016-05-06

Incorrect or delayed diagnosis and treatment of the carpometacarpal fracture-dislocations is often associated with poor prognosis. We present a rare case of unusual pattern of injury, involving dorsal dislocation of four ulnar carpometacarpal joints, associated with fracture of the trapezium, a burst fracture of the trapezoid  bone and an extra-articular fracture of the third distal  of the radius. The first surgical intervention was followed by unsatisfactory results, confirmed by the CT scans. A second surgery followed and an open reduction and pinning with K wires performed. Post-operative follow up lasting for nine months revealed a very good surgical outcome.

Liquid inflow to a baffled cylindrical tank during weightlessness

NASA Technical Reports Server (NTRS)

Staskus, J. V.

1972-01-01

An experimental investigation was conducted in which the behavior of liquid inflow to a cylindrical tank containing inlet baffles was observed during weightlessness. A single tank radius (2 cm), inlet radius (0.2 cm), and liquid (ethanol)were used. The inlet end of the tank was hemispherical with a 30 deg convergent inlet. All the baffle configurations tested were cylindrically symmetric and mounted coaxially with the tank within the hemispherical end. Both stable and unstable inflow behavior were observed using each baffle. It was found that, depending on which of the baffles was used, the critical inflow velocity at which a transition to unstable inflow began was from 2.5 to 12 times greater than the corresponding velocity in an unbaffled tank.

Association of Insulin-like Growth Factor-1, Bone Mass and Inflammation to Low-energy Distal Radius Fractures and Fracture Healing in Elderly Women Attending Emergency Care.

PubMed

Chisalita, Simona I; Chong, Lee Ti; Wajda, Maciej; Adolfsson, Lars; Woisetschläger, Mischa; Spångeus, Anna

2017-11-01

Elderly patients suffer fractures through low-energy mechanisms. The distal radius is the most frequent fracture localization. Insulin-like growth factor-1 (IGF1) plays an important role in the maintenance of bone mass and its levels decline with advancing age and in states of malnutrition. Our aim was to investigate the association of IGF1 levels, bone mass, nutritional status, and inflammation to low-energy distal radius fractures and also study if fracture healing is influenced by IGF1, nutritional status, and inflammation. Postmenopausal women, 55 years or older, with low-energy distal radius fractures occurring due to falling on slippery ground, indoors or outdoors, were recruited in the emergency department (ED) and followed 1 and 5 weeks after the initial trauma with biomarkers for nutritional status and inflammation. Fractures were diagnosed according to standard procedure by physical examination and X-ray. All patients were conservatively treated with plaster casts in the ED. Patients who needed interventions were excluded from our study. Fracture healing was evaluated from radiographs. Fracture healing assessment was made with a five-point scale where the radiological assessment included callus formation, fracture line, and stage of union. Blood samples were taken within 24 h after fracture and analyzed in the routine laboratory. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA). Thirty-eight Caucasian women, aged 70.5 ± 8.9 years (mean ± SD) old, were recruited. Nutritional status, as evaluated by albumin (40.3 ± 3.1 g/L), IGF1 (125.3 ± 39.9 μg/L), body mass index (26.9 ± 3.6 kg/m 2 ), arm diameter (28.9 ± 8.9 cm), and arm skinfold (2.5 ± 0.7 cm), was normal. A positive correlation was found between IGF1 at visit 1 and the lowest BMD for hip, spine, or radius (r = 0.39, P = 0.04). High sensitive C-reactive protein (hsCRP) and leukocytes were higher at the fracture event compared to 5 weeks later (P = 0.07 and P < 0.001, respectively). Fracture healing parameters (i.e. callus formation, fracture line, and stage of union) were positively correlated with the initial leukocyte count and to difference in thrombocyte count between visit 1 and 3. In elderly women with low-energy distal radius fractures, an association between IGF1 and lowest measures of BMD was found, indicating that low IGF1 could be an indirect risk factor for fractures. Fracture healing was associated with initial leukocytosis and a lower thrombocyte count, suggesting that inflammation and thrombocytes are important components in fracture healing. © 2017 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

Does Wrist Arthrodesis With Structural Iliac Crest Bone Graft After Wide Resection of Distal Radius Giant Cell Tumor Result in Satisfactory Function and Local Control?

PubMed

Wang, Tao; Chan, Chung Ming; Yu, Feng; Li, Yuan; Niu, Xiaohui

2017-03-01

Many techniques have been described for reconstruction after distal radius resection for giant cell tumor with none being clearly superior. The favored technique at our institution is total wrist fusion with autogenous nonvascularized structural iliac crest bone graft because it is structurally robust, avoids the complications associated with obtaining autologous fibula graft, and is useful in areas where bone banks are not available. However, the success of arthrodesis and the functional outcomes with this approach, to our knowledge, have only been limitedly reported. (1) What is the success of union of these grafts and how long does it take? (2) How effective is the technique in achieving tumor control? (3) What complications occur with this type of arthrodesis? (4) What are the functional results of wrist arthrodesis by this technique for treating giant cell tumor of the distal radius? Between 2005 and 2013, 48 patients were treated for biopsy-confirmed Campanacci Grade III giant cell tumor of the distal radius. Of those, 39 (81% [39 of 48]) were treated with wrist arthrodesis using autogenous nonvascularized iliac crest bone graft. Of those, 27 (69% [27 of 39]) were available for followup at a minimum of 24 months (mean, 45 months; range, 24-103 months). During that period, the general indications for this approach were Campanacci Grade III and estimated resection length of 8 cm or less. Followup included clinical and radiographic assessment and functional assessment using the Disabilities of the Arm, Shoulder and Hand (DASH) score, the Musculoskeletal Tumor Society (MSTS) score, grip strength, and range of motion at every followup by the treating surgeon and his team. All functional results were from the latest followup of each patient. Union of the distal junction occurred at a mean of 4 months (± 2 months) and union of the proximal junction occurred at a mean of 9 months (± 5 months). Accounting for competing events, at 12 months, the rate of proximal junction union was 56% (95% confidence interval [CI], 35%-72%), whereas it was 67% (95% CI, 45%-82%) at 18 months. In total, 11 of the 27 patients (41%) underwent repeat surgery on the distal radius, including eight patients (30%) who had complications and three (11%) who had local recurrence. The mean DASH score was 9 (± 7) (value range, 0-100, with lower scores representing better function), and the mean MSTS 1987 score was 29 (± 1) (value range, 0-30, with higher scores representing better function) as well as 96% (± 4%) of mean MSTS 1993 score (value range, 0%-100%, with higher scores representing better function). The mean grip strength was 51% (± 23%) of the uninvolved side, whereas the mean arc of forearm rotation was 113° (± 49°). Reconstruction of defects after resection of giant cell tumor of the distal radius with autogenous structural iliac crest bone graft is a facile technique that can be used to achieve favorable functional results with complications and recurrences comparable to those of other reported techniques. We cannot show that this technique is superior to other options, but it seems to be a reasonable option to consider when other reconstruction options such as allografts are not available. Level IV, therapeutic study.

Radiographical measurements for distal intra-articular fractures of the radius using plain radiographs and cone beam computed tomography images.

PubMed

Suojärvi, Nora; Sillat, T; Lindfors, N; Koskinen, S K

2015-12-01

Operative treatment of an intra-articular distal radius fracture is one of the most common procedures in orthopedic and hand surgery. The intra- and interobserver agreement of common radiographical measurements of these fractures using cone beam computed tomography (CBCT) and plain radiographs were evaluated. Thirty-seven patients undergoing open reduction and volar fixation for a distal radius fracture were studied. Two radiologists analyzed the preoperative radiographs and CBCT images. Agreement of the measurements was subjected to intra-class correlation coefficient and the Bland-Altman analyses. Plain radiographs provided a slightly poorer level of agreement. For fracture diastasis, excellent intraobserver agreement was achieved for radiographs and good or excellent agreement for CBCT, compared to poor interobserver agreement (ICC 0.334) for radiographs and good interobserver agreement (ICC 0.621) for CBCT images. The Bland-Altman analyses indicated a small mean difference between the measurements but rather large variation using both imaging methods, especially in angular measurements. For most of the measurements, radiographs do well, and may be used in clinical practice. Two different measurements by the same reader or by two different readers can lead to different decisions, and therefore a standardization of the measurements is imperative. More detailed analysis of articular surface needs cross-sectional imaging modalities.

In Vivo, Non-Invasive Characterization of Human Bone by Hybrid Broadband (600-1200 nm) Diffuse Optical and Correlation Spectroscopies.

PubMed

Konugolu Venkata Sekar, Sanathana; Pagliazzi, Marco; Negredo, Eugènia; Martelli, Fabrizio; Farina, Andrea; Dalla Mora, Alberto; Lindner, Claus; Farzam, Parisa; Pérez-Álvarez, Núria; Puig, Jordi; Taroni, Paola; Pifferi, Antonio; Durduran, Turgut

2016-01-01

Non-invasive in vivo diffuse optical characterization of human bone opens a new possibility of diagnosing bone related pathologies. We present an in vivo characterization performed on seventeen healthy subjects at six different superficial bone locations: radius distal, radius proximal, ulna distal, ulna proximal, trochanter and calcaneus. A tailored diffuse optical protocol for high penetration depth combined with the rather superficial nature of considered tissues ensured the effective probing of the bone tissue. Measurements were performed using a broadband system for Time-Resolved Diffuse Optical Spectroscopy (TRS) to assess mean absorption and reduced scattering spectra in the 600-1200 nm range and Diffuse Correlation Spectroscopy (DCS) to monitor microvascular blood flow. Significant variations among tissue constituents were found between different locations; with radius distal rich of collagen, suggesting it as a prominent location for bone related measurements, and calcaneus bone having highest blood flow among the body locations being considered. By using TRS and DCS together, we are able to probe the perfusion and oxygen consumption of the tissue without any contrast agents. Therefore, we predict that these methods will be able to evaluate the impairment of the oxygen metabolism of the bone at the point-of-care.

In Vivo, Non-Invasive Characterization of Human Bone by Hybrid Broadband (600-1200 nm) Diffuse Optical and Correlation Spectroscopies

PubMed Central

Pagliazzi, Marco; Negredo, Eugènia; Martelli, Fabrizio; Farina, Andrea; Dalla Mora, Alberto; Lindner, Claus; Farzam, Parisa; Pérez-Álvarez, Núria; Puig, Jordi; Taroni, Paola; Pifferi, Antonio; Durduran, Turgut

2016-01-01

Non-invasive in vivo diffuse optical characterization of human bone opens a new possibility of diagnosing bone related pathologies. We present an in vivo characterization performed on seventeen healthy subjects at six different superficial bone locations: radius distal, radius proximal, ulna distal, ulna proximal, trochanter and calcaneus. A tailored diffuse optical protocol for high penetration depth combined with the rather superficial nature of considered tissues ensured the effective probing of the bone tissue. Measurements were performed using a broadband system for Time-Resolved Diffuse Optical Spectroscopy (TRS) to assess mean absorption and reduced scattering spectra in the 600–1200 nm range and Diffuse Correlation Spectroscopy (DCS) to monitor microvascular blood flow. Significant variations among tissue constituents were found between different locations; with radius distal rich of collagen, suggesting it as a prominent location for bone related measurements, and calcaneus bone having highest blood flow among the body locations being considered. By using TRS and DCS together, we are able to probe the perfusion and oxygen consumption of the tissue without any contrast agents. Therefore, we predict that these methods will be able to evaluate the impairment of the oxygen metabolism of the bone at the point-of-care. PMID:27997565

A functional outcomes survey of elderly patients who sustained distal radius fractures.

PubMed

Amorosa, Louis F; Vitale, Mark A; Brown, Shervondalonn; Kaufmann, Robert A

2011-09-01

This study aims to examine the subjective functional outcomes of patients 70 years or older who sustained distal radius fractures through the use of the Disability of the Arm, Shoulder, and Hand (DASH) and Short Form-8 Health (SF-8) surveys. Patients at least 70 years old with a distal radius fracture between 2000 and 2004 were identified and their charts reviewed. They were contacted to answer the DASH and SF-8 surveys. The radiographic injury parameters examined were articular stepoff greater than 2 mm, dorsal tilt on the lateral radiograph, ulnar variance, and presence of an ulnar styloid fracture. Fifty-eight patients answered the DASH and SF-8 surveys. The mean age at the time of injury in the survey group was 78 years old (range 70-94 years). Mean follow-up period was 33 months (range 13-65 months). Average DASH and SF-8 scores were 22.3 (SD 22.4) and 31.5 (SD 6.9), respectively. DASH scores were inversely correlated with SF-8 scores (R = -0.65, p < 0.01). Patients who sustained an associated ulnar styloid fracture demonstrated worse DASH scores than those without an ulnar styloid fracture (presence of ulnar styloid fracture: mean DASH 26.2, no ulnar styloid fracture: mean DASH 12.9, p = 0.04). There were no significant differences in functional outcome for any other radiographic parameters assessed. Males had statistically better DASH scores than the females (males: mean DASH 6.9, females: mean DASH 24.4, p = 0.003). No difference was found in functional outcome scores among different treatment groups. In elderly patients with distal radius fractures, the only radiographic parameter we found that affects functional outcome is an associated ulnar styloid fracture. Additionally, females had worse functional outcomes than males.

Outcome Analysis of Intra-Articular Scapula Fracture Fixation with Distal Radius Plate: A Multicenter Prospective Study.

PubMed

Panigrahi, Ranajit; Madharia, Divya; Das, Dibya Singha; Samant, Saswat; Biswal, Manas Ranjan

2016-12-01

Scapula fractures occur in approximately 1% of all fractures and constitute about 3% - 5% of all injuries of the shoulder joint. This study aimed to evaluate the clinical outcomes of 20 surgically treated patients with displaced glenoid fractures after stabilization with distal radius plate. 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. 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%. 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.

[Intraoperative virtual implant planning for volar plate osteosynthesis of distal radius fractures].

PubMed

Franke, J; Vetter, S Y; Reising, K; Herrmann, S; Südkamp, N P; Grützner, P A; von Recum, J

2016-01-01

Digital planning of implants is in most cases conducted prior to surgery. The virtual implant planning system (VIPS) is an application developed for mobile C-arms, which assists the virtual planning of screws close to the joint line during surgery for treatment of distal radius fractures with volar plate osteosynthesis. The aim of this prospective randomized study was to acquire initial clinical experiences and to compare the VIPS method with the conventional technique. The study included 10 patients for primary testing and 30 patients with distal radius fractures of types A3, C1 and C2, divided in 2 groups. In the VIPS group, after placement of the plate and fracture reduction, a virtual 3D model of the plate was matched with the image of the plate from the fluoroscopic acquisition. Next, the length and position of the screws close to the joint line were planned on the virtual plate. The control group was treated with the same implant in the conventional way. Data were collected regarding screw replacement, fluoroscopy and operating room (OR) times. The VIPS group included six A3, one C1 and eight C2 fractures, while the control group consisted of six A3 and nine C2 fractures. Three screws were replaced in the VIPS group and two in the control group (p = 0.24). The mean intraoperative fluoroscopy time of the VIPS group amounted to 2.58 ± 1.38 min, whereas it was 2.12 ± 0.73 min in the control group (p = 0.26). The mean OR time in the VIPS group was 53.3 ± 34.5 minutes and 42.3 ± 8.8 min (p = 0.23) in the control group. The VIPS enables a precise positioning of screws close to joint line in the treatment of distal radius fractures; however, for routine use, further development of the system is necessary.

Volar plate fixation failure for volar shearing distal radius fractures with small lunate facet fragments.

PubMed

Beck, John D; Harness, Neil G; Spencer, Hillard T

2014-04-01

To determine the percentage of AO B3 distal radius fractures that lose reduction after operative fixation and to see whether fracture morphology, patient factors, or fixation methods predict failure. We hypothesized that initial fracture displacement, amount of lunate facet available for fixation, plate position, and screw fixation would be significant risk factors for loss of reduction. A prospective, observational review was conducted of 51 patients (52 fractures) with AO B3 (volar shearing) distal radius fractures treated operatively between January 2007 and June 2012. We reviewed a prospective distal radius registry to determine demographic data, medical comorbidities, and physical examination findings. Radiographs were evaluated for AO classification, loss of reduction, length of volar cortex available for fixation, and adequacy of stabilization of the lunate facet fragment with a volar plate. Preoperative data were compared between patients who maintained radiographic alignment and those with loss of reduction. A multivariate logistic regression analysis was completed to determine significant predictors of loss of reduction. Volar shearing fractures with separate scaphoid and lunate facet fragments (AO B3.3), preoperative lunate subsidence distance, and length of volar cortex available for fixation were significant predictors for loss of reduction; the latter was significant in multivariate analysis. Plate position and number of screws used to stabilize the lunate facet were not statistically different between groups. Patients with AO B3.3 fractures with less than 15 mm of lunate facet available for fixation, or greater than 5 mm of initial lunate subsidence, are at risk for failure even if a volar plate is properly placed. In these cases, we recommend additional fixation to maintain reduction of the small volar lunate facet fracture fragments in the form of plate extensions, pins, wires, suture, wire forms, or mini screws. Therapeutic III. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Radiographic Outcomes of Volar Locked Plating for Distal Radius Fractures

PubMed Central

Mignemi, Megan E.; Byram, Ian R.; Wolfe, Carmen C.; Fan, Kang-Hsien; Koehler, Elizabeth A.; Block, John J.; Jordanov, Martin I.; Watson, Jeffry T.; Weikert, Douglas R.; Lee, Donald H.

2013-01-01

Purpose To assess the ability of volar locked plating to achieve and maintain normal radiographic parameters for articular stepoff, volar tilt, radial inclination, ulnar variance, and radial height in distal radius fractures. Methods We performed a retrospective review of 185 distal radius fractures that underwent volar locked plating with a single plate design over a 5-year period. We reviewed radiographs and recorded measurements for volar tilt, radial inclination, ulnar variance, radial height, and articular stepoff. We used logistic regression to determine the association between return to radiographic standard norms and fracture type. Results At the first and final postoperative follow-up visits, we observed articular congruence less than 2 mm in 92% of fractures at both times. Normal volar tilt (11°) was restored in 46% at the first follow-up and 48% at the final one. Radial inclination (22°) was achieved in 44% at the first follow-up and 43% at the final one, and ulnar variance (01 ± 2 mm) was achieved in 53% at the first follow-up and 53% at the final one. In addition, radial height (14 ± 1mm) was restored in 14% at the first follow-up and 12% at the final one. More complex, intra-articular fractures (AO class B and C and Frykman types 3, 4, 7, and 8) were less likely to be restored to normal radiographic parameters. However, because of the small sample size for some fracture types, it was difficult to discover significant associations between fracture type and radiographic outcome. Conclusions Volar locked plating for distal radius fractures achieved articular stepoff less than 2 mm in most fractures but only restored and maintained normal radiographic measurements for volar tilt, radial inclination, and ulnar variance in 50% of fractures. The ability of volar locked plating to restore and maintain ulnar variance and volar tilt decreased with more complex intra-articular fracture types. PMID:23218558

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

Open reduction and internal fixation versus casting for highly comminuted and intra-articular fractures of the distal radius (ORCHID): protocol for a randomized clinical multi-center trial.

PubMed

Bartl, Christoph; Stengel, Dirk; Bruckner, Thomas; Rossion, Inga; Luntz, Steffen; Seiler, Christoph; Gebhard, Florian

2011-03-22

Fractures of the distal radius represent the most common fracture in elderly patients, and often indicate the onset of symptomatic osteoporosis. A variety of treatment options is available, including closed reduction and plaster casting, K-wire-stabilization, external fixation and open reduction and internal fixation (ORIF) with volar locked plating. The latter is widely promoted by clinicians and hardware manufacturers. Closed reduction and cast stabilization for six weeks is a simple, convenient, and ubiquitously available intervention. In contrast, ORIF requires hospitalization, but allows for functional rehabilitation.Given the lack of randomized controlled trials, it remains unclear whether ORIF leads to better functional outcomes one year after injury than closed reduction and casting. ORCHID (Open reduction and internal fixation versus casting for highly comminuted intra-articular fractures of the distal radius) is a pragmatic, randomized, multi-center, clinical trial with two parallel treatment arms. It is planned to include 504 patients in 15 participating centers throughout Germany over a three-year period. Patients are allocated by a central web-based randomization tool.The primary objective is to determine differences in the Short Form 36 (SF-36) Physical Component Score (PCS) between volar locked plating and closed reduction and casting of intraarticular, comminuted distal radius fractures in patients > 65 years of age one year after the fracture. Secondary outcomes include differences in other SF-36 dimensions, the EuroQol-5D questionnaire, the Disability of the Arm, Shoulder, and Hand (DASH) instrument. Also, the range of motion in the affected wrist, activities of daily living, complications (including secondary ORIF and revision surgery), as well as serious adverse events will be assessed. Data obtained during the trial will be used for later health-economic evaluations. The trial architecture involves a central statistical unit, an independent monitoring institute, and a data safety monitoring board. Following approval by the institutional review boards of all participating centers, conduct and reporting will strictly adhere to national and international rules, regulations, and recommendations (e.g., Good Clinical Practice, data safety laws, and EQUATOR/CONSORT proposals). To our knowledge, ORCHID is the first multicenter RCT designed to assess quality of life and functional outcomes following operative treatment compared to conservative treatment of complex, intra-articular fractures of the distal radius in elderly patients. The results are expected to influence future treatment recommendations and policies on an international level. ISRCTN: ISRCTN76120052 Registration date: 31.07.2008; Randomization of first patient: 15.09.2008.

Microarchitectural Deterioration of Cortical and Trabecular Bone: Differing Effects of Denosumab and Alendronate

PubMed Central

Seeman, Ego; Delmas, Pierre D; Hanley, David A; Sellmeyer, Deborah; Cheung, Angela M; Shane, Elizabeth; Kearns, Ann; Thomas, Thierry; Boyd, Steven K; Boutroy, Stephanie; Bogado, Cesar; Majumdar, Sharmila; Fan, Michelle; Libanati, Cesar; Zanchetta, Jose

2015-01-01

The intensity of bone remodeling is a critical determinant of the decay of cortical and trabecular microstructure after menopause. Denosumab suppresses remodeling more than alendronate, leading to greater gains in areal bone mineral density (aBMD). These greater gains may reflect differing effects of each drug on bone microarchitecture and strength. In a phase 2 double-blind pilot study, 247 postmenopausal women were randomized to denosumab (60mg subcutaneous 6 monthly), alendronate (70mg oral weekly), or placebo for 12 months. All received daily calcium and vitamin D. Morphologic changes were assessed using high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia and QCT at the distal radius. Denosumab decreased serum C-telopeptide more rapidly and markedly than alendronate. In the placebo arm, total, cortical, and trabecular BMD and cortical thickness decreased (−2.1% to −0.8%) at the distal radius after 12 months. Alendronate prevented the decline (−0.6% to 2.4%, p = .051 to < .001 versus placebo), whereas denosumab prevented the decline or improved these variables (0.3% to 3.4%, p < .001 versus placebo). Changes in total and cortical BMD were greater with denosumab than with alendronate (p ≤ .024). Similar changes in these parameters were observed at the tibia. The polar moment of inertia also increased more in the denosumab than alendronate or placebo groups (p < .001). Adverse events did not differ by group. These data suggest that structural decay owing to bone remodeling and progression of bone fragility may be prevented more effectively with denosumab. PMID:20222106

Airspace Dimension Assessment with nanoparticles reflects lung density as quantified by MRI

PubMed Central

Jakobsson, Jonas K; Löndahl, Jakob; Olsson, Lars E; Diaz, Sandra; Zackrisson, Sophia; Wollmer, Per

2018-01-01

Background Airspace Dimension Assessment with inhaled nanoparticles is a novel method to determine distal airway morphology. This is the first empirical study using Airspace Dimension Assessment with nanoparticles (AiDA) to estimate distal airspace radius. The technology is relatively simple and potentially accessible in clinical outpatient settings. Method Nineteen never-smoking volunteers performed nanoparticle inhalation tests at multiple breath-hold times, and the difference in nanoparticle concentration of inhaled and exhaled gas was measured. An exponential decay curve was fitted to the concentration of recovered nanoparticles, and airspace dimensions were assessed from the half-life of the decay. Pulmonary tissue density was measured using magnetic resonance imaging (MRI). Results The distal airspace radius measured by AiDA correlated with lung tissue density as measured by MRI (ρ = −0.584; p = 0.0086). The linear intercept of the logarithm of the exponential decay curve correlated with forced expiratory volume in one second (FEV1) (ρ = 0.549; p = 0.0149). Conclusion The AiDA method shows potential to be developed into a tool to assess conditions involving changes in distal airways, eg, emphysema. The intercept may reflect airway properties; this finding should be further investigated.

FACTORS ASSOCIATED WITH COMPLEX REGIONAL PAIN SYNDROME IN SURGICALLY TREATED DISTAL RADIUS FRACTURE.

PubMed

Ortiz-Romero, Joel; Bermudez-Soto, Ignacio; Torres-González, Rubén; Espinoza-Choque, Fernando; Zazueta-Hernandez, Jesús Abraham; Perez-Atanasio, José Manuel

2017-01-01

The aim of this study was to identify factors associated with developing complex regional pain syndrome (CRPS) after surgical treatment for distal radius fracture (DRF). This case-control study analyzed patients seen from January 2014 to January 2016. Results: In our sample of 249 patients, 4% developed CRPS. Associated factors were economic compensation via work disability (odds ratio [OR] 14.3), age (OR 9.38), associated fracture (OR 12.94), and level of impact (OR 6.46), as well as psychiatric history (OR 7.21). Economically-productive aged patients with a history of high-impact trauma and patients with a history of psychiatric disorders have greater risk of developing CRPS after DRF. Level of Evidence III, Case-Control Study.

Revascularization procedures for Kienböck disease.

PubMed

Kakar, Sanjeev; Giuffre, Jennifer L; Shin, Alexander Y

2011-03-01

The goals of treatment in Kienböck disease include preservation of wrist function, maintaining normal wrist kinematics, and revascularization of the necrotic lunate when and if possible. A variety of pedicled vascularized bone graft options exist and include but are not limited to pedicled grafts from the volar radius, dorsal radius, metacarpal heads or bases, and pisiform. Of the various treatment options, pedicled vascularized bone grafts from the dorsal distal radius based on the fourth and fifth extensor compartment arteries has been successful in the revascularization of the necrotic lunate at our institution. Vascularized bone grafting is an attractive alternative to conventional bone grafting by improving the local biological environment and thereby promoting revascularization. Recent advances in the anatomy and physiology of vascularized pedicled bone grafts have increased our ability to apply them to the treatment of Kienböck disease. The purpose of this article is to describe the various types of pedicled vascularized bone graft available, to detail the vascular anatomy of the dorsal distal radius, and to describe the surgical technique of our preferred vascularized bone graft (the fourth+fifth extensor compartment artery graft). In addition, the indications, contraindications, and outcomes are described.

Complications of volar locking plating of distal radius fractures in 576 patients with 3.2 years follow-up.

PubMed

Thorninger, Rikke; Madsen, Mette Lund; Wæver, Daniel; Borris, Lars Carl; Rölfing, Jan Hendrik Duedal

2017-06-01

Volar plating of unstable distal radius fractures (DRF) has become the favoured treatment. The complication rates vary from 3 to 36%. The purpose of the study was to estimate the complication rate of volar plating of DRF and its association with AO/OTA fracture type, surgeon experience and type of volar plate. Retrospectively, all patients treated with volar plating of a DRF between February 2009 and June 2013 at Aarhus University Hospital, Denmark were included. AO/OTA fracture type, surgeon experience (1st year, 2nd-5th year resident or consultant), type of plate (VariAx ® , Acu-Loc ® ) and complications were extracted from the electronic medical records. Complications were categorized as carpal tunnel syndrome, other sensibility issues, tendon complications including irritation and rupture, deep infections, complex regional pain syndrome and unidentified DRUJ or scapholunar problems. Reoperations including hardware removal were also charted. 576 patients with a median age of 63 years (min: 15; max: 87) were included. 78% were female and the mean observation time was 3.2 years (min: 2.0; max: 5.4). 78% (n=451) of the patients were treated with VariAx ® and 22% (n=125) with Acu-Loc ® . The overall complication rate was 14.6% (95% CI 11.8-17.7) including carpal tunnel syndrome or change in sensibility in 5.2% and tendon complications in 4.7%. Five flexor tendon ruptures and 12 extensor tendon ruptures were observed. The reoperation rate was 10.4% including 41 cases of hardware removal. A statistically significant association between AO/OTA fracture type C and complications was found. No statistically significant association between complication rate and surgeon experience and type of plate was observed. The majority of DRF patients treated with a volar plate suffer no complications. However, the overall complication rate of 14.6% is substantial. Intra-articular fractures, e.g. AO/OTA-type 23C1-3, had significantly higher complication rates. Neither surgeon experience, nor type of volar plate was able to predict complications. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed

Kanchanatawan, Wichan; Wongthongsalee, Ponrachai

2016-02-01

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

Hairline fractures following volar plating of the distal radius: a recently recognized hardware-related complication.

PubMed

Otremski, Hila; Dolkart, Oleg; Atlan, Franck; Hutt, Dan; Segev, Elad; Pritsch, Tamir; Rosenblatt, Yishai

2018-06-01

Intraoperative hairline longitudinal fractures were recently reported in association with distal radius volar plating. Our aim was to further analyze this newly described complication. A retrospective radiographic and chart review was performed on 225 patients who underwent distal radius plating between June 2013 and June 2015. The Acu-Loc/Acu-Loc2© plating system (Acumed, Hillsboro, OR, USA) was used in 208 cases, and the VariAx© plating system (Stryker, Kalamazoo, MI, USA) was used in 17 cases. Three independent reviewers performed a blind evaluation of all relevant radiographs for the occurrence of longitudinal fractures around the plate, and validity was considered only when there was agreement among all three of them. Hairline longitudinal fractures were identified in 57 cases (25%), 55 with the Acu-Loc/Acu-Loc2© system and 2 with the VariAx© system. All fractures occurred with volar plating. Fracture occurrence was associated with age over 59 years, female gender, extra-articular fractures, and the use of Hexalobe screws (Acu-Loc/Acu-Loc2© system). We believe that the source of fracture occurrence lies within the screw design and that better screw design and possibly tapping in patients at risk may reduce the occurrence of intraoperative hairline longitudinal fractures. Further clinical and biomechanical research is needed to better understand this newly reported complication.

Apparent Disk-mass Reduction and Planetisimal Formation in Gravitationally Unstable Disks in Class 0/I Young Stellar Objects

NASA Astrophysics Data System (ADS)

Tsukamoto, Y.; Okuzumi, S.; Kataoka, A.

2017-04-01

We investigate the dust structure of gravitationally unstable disks undergoing mass accretion from the envelope, envisioning its application to Class 0/I young stellar objects (YSOs). We find that the dust disk quickly settles into a steady state and that, compared to a disk with interstellar medium (ISM) dust-to-gas mass ratio and micron-sized dust, the dust mass in the steady state decreases by a factor of 1/2 to 1/3, and the dust thermal emission decreases by a factor of 1/3 to 1/5. The latter decrease is caused by dust depletion and opacity decrease owing to dust growth. Our results suggest that the masses of gravitationally unstable disks in Class 0/I YSOs are underestimated by a factor of 1/3 to 1/5 when calculated from the dust thermal emission assuming an ISM dust-to-gas mass ratio and micron-sized dust opacity, and that a larger fraction of disks in Class 0/I YSOs is gravitationally unstable than was previously believed. We also investigate the orbital radius {r}{{P}} within which planetesimals form via coagulation of porous dust aggregates and show that {r}{{P}} becomes ˜20 au for a gravitationally unstable disk around a solar mass star. Because {r}{{P}} increases as the gas surface density increases and a gravitationally unstable disk has maximum gas surface density, {r}{{P}}˜ 20 {au} is the theoretical maximum radius for planetesimal formation. We suggest that planetesimal formation in the Class 0/I phase is preferable to that in the Class II phase because a large amount of dust is supplied by envelope-to-disk accretion.

Radius morphology and its effects on rotation with contoured and noncontoured plating of the proximal radius.

PubMed

Rupasinghe, Shavantha L; Poon, Peter C

2012-05-01

The radius has a sagittal bow and a coronal bow. Fractures are often treated with volar anterior plating. However, the sagittal bow is often overlooked when plating. This study looks at radial morphology and the effect of plating the proximal radius with straight plates and then contoured plates bowed in the sagittal plane. We report our findings and their effect on forearm rotation. Morphology was investigated in 14 radii. Attention was paid to the proximal shaft of the radius and its sagittal bow; from this, 6-, 7-, and 8-hole plates were contoured to fit this bow. A simple transverse fracture was then made at the apex of this bow in 23 cadaver arms. Supination and pronation were compared when plating with a straight plate and a contoured plate. Ten cadavers underwent ulna plating at the same level. The effect on rotation of fractures plated in the distal-third shaft was also measured. A significant reduction in rotation was found when a proximal radius fracture was plated with a straight plate compared with a contoured plate: 10.8°, 12.8°, and 21.7° for 6-, 7-, and 8-hole plates, respectively (P < .05). Forearm rotation was decreased further when a longer plate was used. Ulna or distal shaft plating did not reduce rotation. This study has shown a significant sagittal bow of the proximal shaft of the radius. Plating this with contoured plates in the sagittal plane improves rotation when compared with straight plates. Additional ulna plating is not a source of reduced forearm rotation. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

FACTORS ASSOCIATED WITH COMPLEX REGIONAL PAIN SYNDROME IN SURGICALLY TREATED DISTAL RADIUS FRACTURE

PubMed Central

ORTIZ-ROMERO, JOEL; BERMUDEZ-SOTO, IGNACIO; TORRES-GONZÁLEZ, RUBÉN; ESPINOZA-CHOQUE, FERNANDO; ZAZUETA-HERNANDEZ, JESÚS ABRAHAM; PEREZ-ATANASIO, JOSÉ MANUEL

2017-01-01

ABSTRACT Objective: The aim of this study was to identify factors associated with developing complex regional pain syndrome (CRPS) after surgical treatment for distal radius fracture (DRF). Methods: This case-control study analyzed patients seen from January 2014 to January 2016. Results: In our sample of 249 patients, 4% developed CRPS. Associated factors were economic compensation via work disability (odds ratio [OR] 14.3), age (OR 9.38), associated fracture (OR 12.94), and level of impact (OR 6.46), as well as psychiatric history (OR 7.21). Conclusions: Economically-productive aged patients with a history of high-impact trauma and patients with a history of psychiatric disorders have greater risk of developing CRPS after DRF. Level of Evidence III, Case-Control Study. PMID:29081703

Complications associated with distraction plate fixation of wrist fractures.

PubMed

Hanel, Douglas P; Ruhlman, Scott David; Katolik, Leo I; Allan, Christopher H

2010-05-01

This article discusses the major and minor complications of distal plating in the light of a cohort study carried out by the authors, who reviewed all patients undergoing bridge distraction plate fixation of distal radius fractures by three surgeons in a single level I trauma center. The article discusses the effectiveness and the complication rates associated with the technique. Copyright (c) 2010 Elsevier Inc. All rights reserved.

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

PubMed

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

2013-11-01

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

Internal fixation of pilon fractures of the distal radius.

PubMed Central

Trumble, T. E.; Schmitt, S. R.; Vedder, N. B.

1993-01-01

When closed manipulation fails to restore articular congruity in comminuted, displaced fractures of the distal radius, open reduction and internal fixation is required. Results of surgical stabilization and articular reconstruction of these injuries are reviewed in this retrospective study of 49 patients with 52 displaced, intra-articular distal radius fractures. Forty-three patients (87%) with a mean age of 37 years (range of 17 to 79 years) were available for evaluation. The mean follow-up time was 38 months (range 22-69 months). When rated according to the Association for the Study of Internal Fixation (ASIF), 19 were type C2 and 21 were type C3. We devised an Injury Score System based on the initial injury radiographs to classify severely comminuted intra-articular fractures and to identify those associated with carpal injury (3 patients). Post-operative fracture alignment, articular congruity, and radial length were significantly improved following surgery (p < .01). Grip strength averaged 69% +/- 22% of the contralateral side, and the range of motion averaged 75% +/- 18% of the contralateral side post-operatively. A combined outcome rating system that included grip strength, range of motion, and pain relief averaged 76% +/- 19% of the contralateral side. There was a statistically significant decrease in the combined rating with more severe fracture patterns as defined by the ASIF system (p < .01), Malone classification (p < .03), and the Injury Score System (p < .001). The Injury Score System presented here, and in particular the number of fracture fragments, correlated most closely with outcome of all the classification systems studied. Operative treatment of these distal radius fractures with reconstruction of the articular congruity and correction of the articular surface alignment with internal fixation and/or external fixation, can significantly improve the radiographic alignment and functional outcome. Furthermore, the degree to which articular stepoff, gap between fragments, and radial shortening are improved by surgery is strongly correlated with improved outcome, even when the results are corrected for severity of initial injury, whereas correction of radial tilt or dorsal tilt did not correlate with improved outcome. Images Figure 2 PMID:8209554

Early Rehabilitation of Distal Radius Fractures Stabilized by Volar Locking Plate: A Prospective Randomized Pilot Study

PubMed Central

Quadlbauer, Stefan; Pezzei, Christoph; Jurkowitsch, Josef; Kolmayr, Brigitta; Keuchel, Tina; Simon, Daniel; Hausner, Thomas; Leixnering, Martin

2016-01-01

Background Distal radius fractures are very common and an increased incidence of 50% is estimated by 2030. Therefore, both operative and postsurgical treatment remains pertinent. Main aim in treating intra-articular fractures is to restore the articular surface by internal fixation and early mobilization (EM). Questions/Purposes The purpose of this study was to compare functional results between EM immediately after surgery and 5 weeks of immobilization (IM). Patients and Methods In a randomized prospective study, 30 patients with an isolated distal radius fracture were treated by open reduction and internal fixation using a single volar locking plate excluding bone graft. Fifteen patients were randomized in the EM group and 15 in the IM group. At 6 weeks, 9 weeks, 3 months, 6 months, and 1 year postsurgery, range of motion, grip strength and X-rays were evaluated. Additionally, Quick Disability of the Arm, Shoulder and Hand (QuickDASH) questionnaire, Patient-Rated Wrist Evaluation (PRWE), modified Green O'Brien (Mayo) score, and pain according to the Visual Analog Scale score were analyzed. Results Patients in the EM group had a significantly better range of motion in the sagittal plane, in grip strength up to 6 months, in the frontal plane up to 9 weeks, and in forearm rotation up to 6 weeks. Also QuickDASH and PRWE scores were better up to 6 weeks postsurgery. The Green O'Brien score differed significantly up to 1 year. At 1 year, 93% “excellent” and “good” results in the Green O'Brien score with a mean QuickDASH of 5.98 ± 10.94 and PRWE score of 4.27 ± 9.23 were observed in the EM group. No differences regarding loss of reduction, pain, duration of physiotherapy, and sick leave were noted. Conclusion EM of surgically treated distal radius fractures (without bone graft) is a safe method for postoperative aftercare and leads to an improved range of motion and grip strength at 6 months postsurgery compared with an IM of 5 weeks. Level of Evidence This is a level Ib clinical study. PMID:28428911

Bone strength and muscle properties in postmenopausal women with and without a recent distal radius fracture.

PubMed

Crockett, K; Arnold, C M; Farthing, J P; Chilibeck, P D; Johnston, J D; Bath, B; Baxter-Jones, A D G; Kontulainen, S A

2015-10-01

Distal radius (wrist) fracture (DRF) in women over age 50 years is an early sign of bone fragility. Women with a recent DRF compared to women without DRF demonstrated lower bone strength, muscle density, and strength, but no difference in dual-energy x-ray absorptiometry (DXA) measures, suggesting DXA alone may not be a sufficient predictor for DRF risk. The objective of this study was to investigate differences in bone and muscle properties between women with and without a recent DRF. One hundred sixty-six postmenopausal women (50-78 years) were recruited. Participants were excluded if they had taken bone-altering medications in the past 6 months or had medical conditions that severely affected daily living or the upper extremity. Seventy-seven age-matched women with a fracture in the past 6-24 months (Fx, n = 32) and without fracture (NFx, n = 45) were measured for bone and muscle properties using the nondominant (NFx) or non-fractured limb (Fx). Peripheral quantitative computed tomography (pQCT) was used to estimate bone strength in compression (BSIc) at the distal radius and tibia, bone strength in torsion (SSIp) at the shaft sites, muscle density, and area at the forearm and lower leg. Areal bone mineral density at the ultradistal forearm, spine, and femoral neck was measured by DXA. Grip strength and the 30-s chair stand test were used as estimates of upper and lower extremity muscle strength. Limb-specific between-group differences were compared using multivariate analysis of variance (MANOVA). There was a significant group difference (p < 0.05) for the forearm and lower leg, with the Fx group demonstrating 16 and 19% lower BSIc, 3 and 6% lower muscle density, and 20 and 21% lower muscle strength at the upper and lower extremities, respectively. There were no differences between groups for DXA measures. Women with recent DRF had lower pQCT-derived estimated bone strength at the distal radius and tibia and lower muscle density and strength at both extremities.

Corrective osteotomy for combined intra- and extra-articular distal radius malunion.

PubMed

Buijze, Geert A; Prommersberger, Karl-Josef; González Del Pino, Juan; Fernandez, Diego L; Jupiter, Jesse B

2012-10-01

This study evaluated the functional outcome of corrective osteotomy for combined intra- and extra-articular malunions of the distal radius using multiple outcome scores. We evaluated 18 skeletally mature patients at an average of 78 months after corrective osteotomy for a combined intra- and extra-articular malunion of the distal part of the radius. The indication for osteotomy in all patients was the combination of an extra-articular deformity (≥ 15° volar or ≥ 10° dorsal angulation or ≥ 3 mm radial shortening) and intra-articular incongruity of 2 mm or greater (maximum stepoff or gap), as measured on lateral and posteroanterior radiographs. The average interval from the injury to the osteotomy was 9 months. The average maximum stepoff or gap of the articular surface before surgery was 4 mm. All 18 patients healed uneventfully and the final articular incongruity was reduced to 2 mm or less. Final range of motion and grip strength significantly improved, averaging 89% and 84% of the uninjured side and 185% and 241% of the preoperative measures, respectively. The rate of excellent or good results was 72% according to the validated rating system Mayo Modified Wrist Score, and 89% according to the unvalidated system of Gartland and Werley. The mean Disabilities of the Arm, Shoulder, and Hand score was 11, which corresponds to mild perceived disability. Of the 18 cases, 11 normalized upper limb function. Five patients had complications; all were successfully treated. According to the rating system of Knirk and Jupiter, 4 had grade 1 and 1 had grade 2 osteoarthritis of the radiocarpal joint on radiographs. Two of those patients reported occasional mild pain. Radiographic osteoarthritis did not correlate with strength, motion, and wrist scores. Outcomes of corrective osteotomy for combined intra- and extra-articular malunions were comparable to those of osteotomy for isolated intra- and extra-articular malunions. A successful corrective osteotomy for the treatment of complex intra- and extra-articular distal radius malunions can improve wrist function. Therapeutic IV. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Effects of the Kelvin-Helmholtz surface instability on supersonic jets

NASA Technical Reports Server (NTRS)

Hardee, P. E.

1982-01-01

An exact numerical calculation is provided for of linear growth and phase velocity of Kelvin-Helmholtz unstable wave modes on a supersonic jet of cylindrical cross section. An expression for the maximally unstable wavenumber of each wave mode is found. Provided a sharp velocity discontinuity exists all wave modes are unstable. A combination of rapid jet expansion and velocity shear across a jet can effectively stabilize all wave modes. The more likely case of slow jet expansion and of velocity shear at the jet surface allows wave modes with maximally unstable wavelength longer than or on the order of the jet radius to grow. The relative energy in different wave modes and effect on the jet is investigated. Energy input into a jet resulting from surface instability is discussed.

Radiographic and functional evaluation of low profile dorsal versus volar plating for distal radius fractures.

PubMed

Kumar, Sanjay; Khan, A N; Sonanis, S V

2016-12-01

Fracture of the distal radius is a common clinical problem. Complex fracture requires open reduction and stabilization with plating to restore anatomy. Dorsal plating has advantages of buttressing the fracture better but often complicated with tendon problems as per literature. The rate of complications however, was not compared between the low-profile dorsal and the volar plates. This was a retrospective study on seventy one patients with dorsally angulated or displaced distal radius fractures, who underwent fixation of fractures with either dorsal or volar locking plate from Jan - Nov 2012. Preoperative radiographs were classified based on Universal and Fernandez classification. Postoperative radiographs were assessed for anatomical restoration of Radial length, radial inclination and volar tilt. Tendon and nerve related complications were assessed and functional evaluation was performed on the basis of PRWE (Patient related wrist evaluation) score. Both groups were matched for their demographic profile and fracture types (p 0.033). Dorsal plating group had 89% excellent/good restoration and fair in 11%. Volar group had 96% excellent/good restoration and fair in 4%. Statistical analysis was performed with unpaired t test for radiographic parameters. Three patients had tendon related complications in dorsal plating group; two patients in volar group had nerve related complications. Functional outcome with PRWE was comparable between two groups. Results with low profile dorsal plating were comparable to volar plating. Therefore dorsal plating can be used as an alternative method when dorsal buttressing of comminuted fracture is required, especially with concomitant osteoporosis.

Long-term results after vascularised bone graft as treatment of Kienböck disease.

PubMed

Kirkeby, Lone; von Varfalva Palffy, Lena; Hansen, Torben Bæk

2014-02-01

The aim of this study was to present the long-term results in a small series of patients with Kienböck disease treated with a pedicled vascularised bone graft from the 4/5 extensor compartment of the distal radius as the only surgical treatment. In the period 2002-2006, five patients, three men and two women, mean age 41 years (22-54) were operated on using a pedicled vascularised bone graft from the 4/5 extensor compartment of the distal radius as described by Sheetz et al. Four patients were staged as Lichtman stage 2 and one as Lichtman stage 3. At the follow-up examination with radiographs and clinical examination at a mean of 7.4 years (5-9) after the operation, they all stated that they were satisfied with the operation. None of the patients had any further surgery in the observation period. Four patients were fully employed, and only one had changed employment due to his hand. The last patient was on a medical pension due to other medical causes. In all patients, no sign of progression was found of the radiological changes in the lunate and in all patients the arches of Gilula were unchanged without signs of carpal collapse. So, in this small series, a pedicled vascularised bone graft from the 4/5 extensor compartment of the distal radius as the only surgical treatment provided good long-term results in patients with stage 2 and 3 Kienböck disease.

The influence of distal screw length on the primary stability of volar plate osteosynthesis--a biomechanical study.

PubMed

Baumbach, Sebastian F; Synek, Alexander; Traxler, Hannes; Mutschler, Wolf; Pahr, Dieter; Chevalier, Yan

2015-09-08

Extensor tendon irritation is one of the most common complications following volar locking plate osteosynthesis (VLPO) for distal radius fractures. It is most likely caused by distal screws protruding the dorsal cortex. Shorter distal screws could avoid this, yet the influence of distal screw length on the primary stability in VLPO is unknown. The aim of this study was to compare 75 to 100% distal screw lengths in VLPO. A biomechanical study was conducted on 11 paired fresh-frozen radii. HRpQCT scans were performed to assess bone mineral density (BMD) and bone mineral content (BMC). The specimens were randomized pair-wise into two groups: 100% (group A) and 75% (group B) unicortical distal screw lengths. A validated fracture model for extra-articular distal radius fractures (AO-23 A3) was used. Polyaxial volar locking plates were mounted, and distal screws was inserted using a drill guide block. For group A, the distal screw tips were intended to be flush or just short of the dorsal cortex. In group B, a target screw length of 75% was calculated. The specimens were tested to failure using a displacement-controlled axial compression test. Primary biomechanical stability was assessed by stiffness, elastic limit, and maximum force as well as with residual tilt, which quantified plastic deformation. Nine specimens were tested successfully. BMD and BMC did not differ between the two groups. The mean distal screw length of group A was 21.7 ± 2.6 mm (range: 16 to 26 mm), for group B 16.9 ± 1.9 mm (range: 12 to 20 mm). Distal screws in group B were on average 5.6 ± 0.9 mm (range: 3 to 7 mm) shorter than measured. No significant differences were found for stiffness (706 ± 103 N/mm vs. 660 ± 124 N/mm), elastic limit (177 ± 25 N vs. 167 ± 36 N), maximum force (493 ± 139 N vs. 471 ± 149 N), or residual tilt (7.3° ± 0.7° vs. 7.1° ± 1.3°). The 75% distal screw length in VLPO provides similar primary stability to 100% unicortical screw length. This study, for the first time, provides the biomechanical basis to choose distal screws significantly shorter then measured.

Gravitational Instability of a Dust Layer Composed of Porous Silicate Dust Aggregates in a Protoplanetary Disk

NASA Astrophysics Data System (ADS)

Tatsuuma, Misako; Michikoshi, Shugo; Kokubo, Eiichiro

2018-03-01

Planetesimal formation is one of the most important unsolved problems in planet formation theory. In particular, rocky planetesimal formation is difficult because silicate dust grains are easily broken when they collide. It has recently been proposed that they can grow as porous aggregates when their monomer radius is smaller than ∼10 nm, which can also avoid the radial drift toward the central star. However, the stability of a layer composed of such porous silicate dust aggregates has not been investigated. Therefore, we investigate the gravitational instability (GI) of this dust layer. To evaluate the disk stability, we calculate Toomre’s stability parameter Q, for which we need to evaluate the equilibrium random velocity of dust aggregates. We calculate the equilibrium random velocity considering gravitational scattering and collisions between dust aggregates, drag by mean flow of gas, stirring by gas turbulence, and gravitational scattering by gas density fluctuation due to turbulence. We derive the condition of the GI using the disk mass, dust-to-gas ratio, turbulent strength, orbital radius, and dust monomer radius. We find that, for the minimum mass solar nebula model at 1 au, the dust layer becomes gravitationally unstable when the turbulent strength α ≲ 10‑5. If the dust-to-gas ratio is increased twice, the GI occurs for α ≲ 10‑4. We also find that the dust layer is more unstable in disks with larger mass, higher dust-to-gas ratio, and weaker turbulent strength, at larger orbital radius, and with a larger monomer radius.

On fluttering modes for aircraft wing model in subsonic air flow.

PubMed

Shubov, Marianna A

2014-12-08

The paper deals with unstable aeroelastic modes for aircraft wing model in subsonic, incompressible, inviscid air flow. In recent author's papers asymptotic, spectral and stability analysis of the model has been carried out. The model is governed by a system of two coupled integrodifferential equations and a two-parameter family of boundary conditions modelling action of self-straining actuators. The Laplace transform of the solution is given in terms of the 'generalized resolvent operator', which is a meromorphic operator-valued function of the spectral parameter λ, whose poles are called the aeroelastic modes. The residues at these poles are constructed from the corresponding mode shapes. The spectral characteristics of the model are asymptotically close to the ones of a simpler system, which is called the reduced model. For the reduced model, the following result is shown: for each value of subsonic speed, there exists a radius such that all aeroelastic modes located outside the circle of this radius centred at zero are stable. Unstable modes, whose number is always finite, can occur only inside this 'circle of instability'. Explicit estimate of the 'instability radius' in terms of model parameters is given.

Lacertus Fibrosus Versus Achilles Allograft Reconstruction for Distal Biceps Tears: A Biomechanical Study.

PubMed

Murthi, Anand M; Ramirez, Miguel A; Parks, Brent G; Carpenter, Shannon R

2017-12-01

The bicipital aponeurosis, or lacertus fibrosus, can potentially be used as a reconstruction graft in chronic distal biceps tendon tears. To evaluate construct stiffness, load to failure, and failure mechanism with lacertus fibrosus versus Achilles allograft for distal biceps tendon reconstruction. Controlled laboratory study. Ten fresh-frozen matched cadaveric pairs of elbows were used. Three centimeters of the distal biceps tendon was resected. Specimens were randomized to the lacertus fibrosus or Achilles tendon group. In one group, the lacertus fibrosus was released from its distal attachment and then tubularized and repaired intraosseously to the radius. In the other group, an Achilles tendon graft was sutured to the biceps muscle and repaired to the ulna. The prepared radii were rigidly mounted at a 45° angle on a load frame. The proximal biceps muscle was secured in a custom-fabricated cryogenic grip. Displacement was measured using a differential variable reluctance transducer mounted at the radius-soft tissue junction and in the muscle- or muscle allograft-tissue junction proximal to the repair. Specimens were loaded at 20 mm/min until failure, defined as a 3-mm displacement at the radius-soft tissue junction. No significant difference was found in mean load to failure between the lacertus fibrosus and Achilles tendon group (mean ± SD, 20.2 ± 5.5 N vs 16.89 ± 4.54 N; P = .18). Stiffness also did not differ significantly between the lacertus fibrosus and Achilles tendon group (12.3 ± 7.1 kPa vs 10.5 ± 5.7 kPa; P = .34). The primary mode of failure in the lacertus fibrosus group was suture pullout from the tissue at the musculotendinous junction (7 of 10). In the Achilles group, failures were observed at the muscle-allograft interface (3) and the allograft-bone (radial tuberosity) interface (3), and 3 suture failures were observed. The button fixation did not fail in any specimens. The mean stiffness and load-to-failure values were not significantly different between a lacertus fibrosus construct and Achilles tendon allograft. Use of the lacertus fibrosus may be a potential alternative to Achilles tendon allograft reconstruction of chronic distal biceps tears when primary repair is not possible.

A rare case of a medullary, multifocal lesion in the distal radius

PubMed Central

Aktas, Birol; Ozturan, Burak; Kilic, Bulent; Ozkan, Korhan

2017-01-01

In multifocal findings, the possibility of multifocal osteoid osteomas should be considered and this case helps us to be attentive for the unusual radiographical presentation of osteoid osteoma. PMID:28748099

In vitro assessment of the contact mechanics of reverse-engineered distal humeral hemiarthroplasty prostheses.

PubMed

Willing, Ryan; Lapner, Michael; King, Graham J W; Johnson, James A

2014-11-01

Distal humeral hemiarthroplasty alters cartilage contact mechanics, which may predispose to osteoarthritis. Current prostheses do not replicate the native anatomy, and therefore contribute to these changes. We hypothesized that prostheses reverse-engineered from the native bone shape would provide similar contact patterns as the native articulation. Reverse-engineered hemiarthroplasty prostheses were manufactured for five cadaveric elbows based on CT images of the distal humerus. Passive flexion trials with constant muscle forces were performed with the native articulation intact while bone motions were recorded using a motion tracking system. Motion trials were then repeated after the distal humerus was replaced with a corresponding reverse-engineered prosthesis. Contact areas and patterns were reconstructed using computer models created from CT scan images combined with the motion tracker data. The total contact areas, as well as the contact area within smaller sub-regions of the ulna and radius, were analyzed for changes resulting from hemiarthroplasty using repeated-measures ANOVAs. Contact area at the ulna and radius decreased on average 42% (SD 19%, P=.008) and 41% (SD 42%, P=.096), respectively. Contact area decreases were not uniform throughout the different sub-regions, suggesting that contact patterns were also altered. Reverse-engineered prostheses did not reproduce the same contact pattern as the native joints, possibly because the thickness of the distal humerus cartilage layer was neglected when generating the prosthesis shapes or as a consequence of the increased stiffness of the metallic implants. Alternative design strategies and materials for hemiarthroplasty should be considered in future work. Copyright © 2014 Elsevier Ltd. All rights reserved.

Open reduction internal fixation of the unstable mallet fracture.

PubMed

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

2010-09-01

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

Estimation of in vivo cortical bone thickness using ultrasonic waves.

PubMed

Mano, Isao; Horii, Kaoru; Hagino, Hiroshi; Miki, Takami; Matsukawa, Mami; Otani, Takahiko

2015-07-01

To verify the measurement of cortical bone thickness at the distal radius in vivo using an ultrasonic method. The method for estimating cortical bone thickness was derived from experiments with in vitro bovine specimens. Propagation time of echo waves and propagation time of slow waves were used for the estimation. The outside diameter of cortical bone and the cortical bone thickness at the distal 5.5 % site of radius were measured with the new ultrasonic bone measurement system, and the results were compared with X-ray pQCT clinical measurements. There was a high positive correlation (r: 0.76) between the cortical bone thickness measured by the new ultrasonic system and the X-ray pQCT results. We will be able to measure not only cancellous bone density but also cortical bone thickness in vivo using ultrasonic waves (without X-ray) safely and repeatedly.

Can radiological results be surrogate markers of functional outcome in distal radial extra-articular fractures?

PubMed

Kumar, Skand; Penematsa, Subbaraju; Sadri, Maziar; Deshmukh, Subodh C

2008-08-01

The purpose of this study was to evaluate the relationship between radiological and functional results in patients with extra-articular fractures of the distal radius. We conducted a prospective study of radiological and functional assessment in 95 consecutively selected extra-articular distal radius fractures. There were two patient groups: more than 60 and less than 60 years of age. The final fracture union radiographs were analysed for their functional outcome using the Michigan Hand Outcomes Questionnaire (MHQ) and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. In patients with acceptable radiological results, 62% (MHQ group) and 72% (DASH group) of patients had satisfactory functional outcome. Analysing patients with satisfactory functional results, 56% (MHQ group) and 59% (DASH group) had satisfactory radiological results. There was a higher proportion of patients with better functional results, despite poor radiological results, in both of the age groups. There was a statistically significant correlation between satisfactory radial tilt and functional outcome in the younger patients. In the older age group, patients with satisfactory radiological results had satisfactory functional outcome (p<0.05). However, in the older age group, satisfactory functional results were achieved, despite unsatisfactory radiological results.

A successful treatment of necrotizing fasciitis following the surgery of distal radius plate removal: A case report and literature review.

PubMed

Cai, Yuchen; Gan, Yaokai; Yu, Chao; Tang, Jian; Sun, Yuehua

2018-04-01

Necrotizing fasciitis (NF) is defined as a rare, rapidly progressive, and highly lethal skin infection characterized by necrosis of the fascia and subcutaneous tissue. The present study aims to discuss the case of a 35-year-old man who developed NF following a routine sterile right distal radius bone plate removal surgery. The patient was suspected of NF based on his clinical manifestations, laboratory tests, and imaging results. The diagnosis of NF was confirmed by histological examinations. Serial prompt and extensive debridement was performed during the rapid and aggressive extension of the skin infection, together with antibiotics and supportive treatments. The condition of the patient finally improved on the sixth day of disease progression. Skin grafting of his right forearm wound was performed successfully 2 months after the admission. NF can occur during the perioperative period for routine clean radius plate removal operation in patients with no risk factor for NF. The objective is to remind the physicians to stay aware of this disease, especially its early clinical signs and symptoms. Urgent subsequent treatment, including surgical debridement, antibiotic therapy, and supporting management, is the key to ensure the survival and better prognosis of patients.

A trans-ethnic genome-wide association study identifies gender-specific loci influencing pediatric aBMD and BMC at the distal radius.

PubMed

Chesi, Alessandra; Mitchell, Jonathan A; Kalkwarf, Heidi J; Bradfield, Jonathan P; Lappe, Joan M; McCormack, Shana E; Gilsanz, Vicente; Oberfield, Sharon E; Hakonarson, Hakon; Shepherd, John A; Kelly, Andrea; Zemel, Babette S; Grant, Struan F A

2015-09-01

Childhood fractures are common, with the forearm being the most common site. Genome-wide association studies (GWAS) have identified more than 60 loci associated with bone mineral density (BMD) in adults but less is known about genetic influences specific to bone in childhood. To identify novel genetic factors that influence pediatric bone strength at a common site for childhood fractures, we performed a sex-stratified trans-ethnic genome-wide association study of areal BMD (aBMD) and bone mineral content (BMC) Z-scores measured by dual energy X-ray absorptiometry at the one-third distal radius, in a cohort of 1399 children without clinical abnormalities in bone health. We tested signals with P < 5 × 10(-6) for replication in an independent, same-age cohort of 486 Caucasian children. Two loci yielded a genome-wide significant combined P-value: rs7797976 within CPED1 in females [P = 2.4 × 10(-11), β =- 0.30 standard deviations (SD) per T allele; aBMD-Z] and rs7035284 at 9p21.3 in males (P = 1.2 × 10(-8), β = 0.28 SD per G allele; BMC-Z). Signals at the CPED1-WNT16-FAM3C locus have been previously associated with BMD at other skeletal sites in adults and children. Our result at the distal radius underscores the importance of this locus at multiple skeletal sites. The 9p21.3 locus is within a gene desert, with the nearest gene flanking each side being MIR31HG and MTAP, neither of which has been implicated in BMD or BMC previously. These findings suggest that genetic determinants of childhood bone accretion at the radius, a skeletal site that is primarily cortical bone, exist and also differ by sex. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Examination of Skill Acquisition and Grader Bias in a Distal Radius Fracture Fixation Model.

PubMed

Putnam, Matthew D; Adams, Julie E; Lender, Paul; Van Heest, Ann E; Shanedling, Janet R; Nuckley, David J; Bechtold, Joan E

2018-03-01

Primary: Assess the ability of faculty graders to predict the objectively measured strength of distal radius fracture fixation. Secondary: Compare resident skill variation and retention related to other knowable training data. Residents were allowed 60 minutes to stabilize a standardized distal radius fracture using an assigned fixed-angle volar plate. Faculty observed and subjectively graded the residents without providing real-time feedback. Objective biomechanical evaluation (construct strength and stiffness) was compared to subjective grades. Resident-specific characteristics (sex, PGY, and ACGME case log) were also used to compare the objective data. A simulated operating room in our laboratory. Post-graduate year 2, 3, 4, and 5 orthopedic residents. Primary: Faculty were not successful at predicting objectively measured fixation, and their subjective scoring suggests confirmation bias as PGY increased. Secondary: Resident year-in-training alone did not predict objective measures (p = 0.53), but was predictive of subjective scores (p < 0.001). Skills learned were not always retained, as 29% of residents objectively failed subsequent to passing. Notably, resident-reported case-specific experience alone was inversely correlated with objective fixation strength. This testing model enabled the collection of objective and subjective resident skill scores. Faculty graders did not routinely predict objective measures, and their subjective assessment appears biased related to PGY. Also, in vivo case volume alone does not predict objective results. Familiar faculty teaching consistency, and resident grading by external faculty unfamiliar with tested residents, might alter these results. Copyright © 2018 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

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

PubMed

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

2017-01-01

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

"Single nucleotide polymorphisms of the OPG/RANKL system genes in primary hyperparathyroidism and their relationship with bone mineral density".

PubMed

Piedra, María; García-Unzueta, María T; Berja, Ana; Paule, Blanca; Lavín, Bernardo A; Valero, Carmen; Riancho, José A; Amado, José A

2011-12-20

Primary hyperparathyroidism (PHPT) affects mainly cortical bone. It is thought that parathyroid hormone (PTH) indirectly regulates the activity of osteoclasts by means of the osteoprotegerin/ligand of the receptor activator of nuclear factor-κβ (OPG/RANKL) system. Several studies have confirmed that OPG (osteoprotegerin) and RANKL (ligand of the receptor activator of nuclear factor-κβ) loci are determinants of bone mineral density (BMD) in the general population. The aim of this study is to analyze the relationship between fractures and BMD and the rs3102735 (163 A/G), rs3134070 (245 T/G) and rs2073618 (1181 G/C) SNPs of the OPG and the rs2277438 SNP of the RANKL, in patients with sporadic PHPT. We enrolled 298 Caucasian patients with PHPT and 328 healthy volunteers in a cross-sectional study. We analyzed anthropometric data, history of fractures or renal lithiasis, biochemical determinants including markers for bone remodelling, BMD measurements in the lumbar spine, total hip, femoral neck and distal radius, and genotyping for the SNPs to be studied. Regarding the age of diagnosis, BMI, menopause status, frequency of fractures or renal lithiasis, we found no differences between genotypes in any of the SNPs studied in the PHPT group. Significant lower BMD in the distal radius with similar PTH levels was found in the minor allele homozygotes (GG) compared to heterozygotes and major allele homozygotes in both OPG rs3102735 (163 A/G) and OPG rs3134070 (245 T/G) SNPs in those with PHPT compared to control subjects. We found no differences between genotypes of the OPG rs2073618 (1181 G/C) SNP with regard to BMD in the PHPT subjects. In the evaluation of rs2277438 SNP of the RANKL in PHPT patients, we found a non significant trend towards lower BMD in the 1/3 distal radius and at total hip in the minor allele homocygotes (GG) genotype group versus heterocygotes and major allele homocygotes (AA). Our study provides the first evaluation of the relationship between SNPs of the OPG/RANK system and sporadic PHPT. Subjects with PHPT and minor homocygote genotype (GG) for the OPG rs3102735 (163 A/G) and OPG rs3134070 (245 T/G) SNPs have lower BMD in the distal radius, and this association does not appear to be mediated by differences in PTH serum levels.

Effects of Passive Porous Walls on the First Mode of Hypersonic Boundary Layers Over a Sharp Cone

DTIC Science & Technology

2013-01-01

perforated with cylindrical blind holes of radius r∗p and equal spacing s ∗ = r∗p √ π/φ0. This model takes into account gas rarefaction effects. We have ρD...admittance Ay and admittance A r y. The flow is unstable above the neutral curves . We see that having a porous coating with phase angle π leads to lower...neutral curves for the higher modes. So there is a destabilising effect in the sense that low frequencies may become unstable. Corresponding results for

Teaching the Basics: Development and Validation of a Distal Radius Reduction and Casting Model.

PubMed

Seeley, Mark A; Fabricant, Peter D; Lawrence, J Todd R

2017-09-01

Approximately one-third of reduced pediatric distal radius fractures redisplace, resulting in further treatment. Two major modifiable risk factors for loss of reduction are reduction adequacy and cast quality. Closed reduction and immobilization of distal radius fractures is an Accreditation Council for Graduate Medical Education residency milestone. Teaching and assessing competency could be improved with a life-like simulation training tool. Our goal was to develop and validate a realistic distal radius fracture reduction and casting simulator as determined by (1) a questionnaire regarding the "realism" of the model and (2) the quantitative assessments of reduction time, residual angulation, and displacement. A distal radius fracture model was created with radiopaque bony segments and articulating elbows and shoulders. Simulated periosteum and internal deforming forces required proper reduction and casting techniques to achieve and maintain reduction. The forces required were estimated through an iterative process through feedback from experienced clinicians. Embedded monofilaments allowed for quantitative assessment of residual displacement and angulation through the use of fluoroscopy. Subjects were asked to perform closed reduction and apply a long arm fiberglass cast. Primary performance variables assessed included reduction time, residual angulation, and displacement. Secondary performance variables consisted of number of fluoroscopic images, casting time, and cast index (defined as the ratio of the internal width of the forearm cast in the sagittal plane to the internal width in the coronal plane at the fracture site). Subject grading was performed by two blinded reviewers. Interrater reliability was nearly perfect across all measurements (intraclass correlation coefficient range, 0.94-0.99), thus disagreements in measurements were handled by averaging the assessed values. After completion the participants answered a Likert-based questionnaire regarding the realism of simulation. Eighteen participants consented to participate in the study (eight attending pediatric orthopaedic surgeons, six junior residents, four senior residents). The performances of junior residents (Postgraduate Year [PGY] 1-2), senior residents (PGY 3-5), and attending surgeons were compared using one-way ANOVA with Tukey's-adjusted pairwise comparisons. The majority of participants (15 of 18) felt that the model looked, felt, and moved like a human forearm. All participants strongly agreed that the model taught the basic steps of fracture reduction and should be implemented in orthopaedic training. Attending surgeons reduced fractures in less time than junior residents (60 ± 27 seconds versus 460 ± 62 seconds; mean difference, 400 seconds; 95% CI, 335-465 seconds; p < 0.001). Residual angulation was greater for junior residents when compared with attending surgeons on AP (7° ± 5° versus 0.7° ± 0.9°; mean difference, 6.3°; 95% CI, 3°-11°; p = 0.003) and lateral (27° ± 7° versus 7° ± 5°; mean difference, 20°; 95% CI, 13°-27°; p = 0.001) radiographs. Similarly, residual displacement was greater for junior residents than either senior residents (mean difference, 16 mm; 95% CI, 2-34 mm; p = 0.05) or attending surgeons (mean difference, 15 mm; 95% CI, 3-27 mm; p = 0.02) on lateral images. There were no differences identified in secondary performance variables (number of fluoroscopic images, casting time, and cast index) between groups. This is the first distal radius fracture reduction model to incorporate an elbow and shoulder and allow quantitative assessment of the fracture reduction. This simulator may be useful in an orthopaedic resident training program to help them reach a defined minimum level of competency. This simulator also could easily be integrated in other accreditation and training programs, including emergency medicine. Level II, therapeutic study.

The utility of dual-energy X-ray absorptiometry, calcaneal quantitative ultrasound, and fracture risk indices (FRAX® and Osteoporosis Risk Assessment Instrument) for the identification of women with distal forearm or hip fractures: A pilot study.

PubMed

Esmaeilzadeh, Sina; Cesme, Fatih; Oral, Aydan; Yaliman, Ayse; Sindel, Dilsad

2016-08-01

Dual-energy X-ray absorptiometry (DXA) is considered the "gold standard" in predicting osteoporotic fractures. Calcaneal quantitative ultrasound (QUS) variables are also known to predict fractures. Fracture risk assessment tools may also guide us for the detection of individuals at high risk for fractures. The aim of this case-control study was to evaluate the utility of DXA bone mineral density (BMD), calcaneal QUS parameters, FRAX® (Fracture Risk Assessment Tool), and Osteoporosis Risk Assessment Instrument (ORAI) for the discrimination of women with distal forearm or hip fractures. This case-control study included 20 women with a distal forearm fracture and 18 women with a hip fracture as cases and 76 age-matched women served as controls. BMD at the spine, proximal femur, and radius was measured using DXA and acoustic parameters of bone were obtained using a calcaneal QUS device. FRAX® 10-year probability of fracture and ORAI scores were also calculated in all participants. Receiver operating characteristic (ROC) analysis was used to assess fracture discriminatory power of all the tools. While all DXA BMD, and QUS variables and FRAX® fracture probabilities demonstrated significant areas under the ROC curves for the discrimination of hip-fractured women and those without, only 33% radius BMD, broadband ultrasound attenuation (BUA), and FRAX® major osteoporotic fracture probability calculated without BMD showed significant discriminatory power for distal forearm fractures. It can be concluded that QUS variables, particularly BUA, and FRAX® major osteoporotic fracture probability without BMD are good candidates for the identification of both hip and distal forearm fractures.

[The Effect of Activation of the Shoulder Girdle Muscles on Functional Outcomes of Rehabilitation in Patients with Surgically Treated Distal Radius Fractures].

PubMed

Jančíková, V; Opavský, J; Dráč, P; Krobot, A; Čižmář, I

2017-01-01

PURPOSE OF THE STUDY The aim of the study was to assess the functional outcomes of rehabilitation in patients with surgically treated distal radius fractures in the early postoperative period. We compared the functional outcomes of patients undergoing standard rehabilitation with the group of patients whose postoperative rehabilitation was extended with shoulder girdle exercises of the affected upper limb while the wrist was immobilized. Several indices and variables were used for the assessment of the functional therapeutic outcomes of the affected wrist. MATERIAL AND METHODS Forty patients (32 females and 8 males, the mean age 60.5 years) with distal radius fractures treated by internal fixation using volar surgical approach were involved in the study between 2013-2016. The tested subjects were randomized and split into two groups according to the selected method of rehabilitation. The tested subjects with standard rehabilitation extended with shoulder girdle muscles activation were labelled as group I. It included patients (n = 20) of the mean age 59.8 (age range 42-73 years) with immobilized wrist (i.e. for 3-4 weeks) performing shoulder girdle muscles exercises at the same time. Furthermore, standard kinesiotherapy continued after their fixation was removed. The other tested group, labelled as group II (n = 20), the mean age 61.3 (variation 40-74 years of age) involved patients with distal radius fractures. Only standard rehabilitation was performed in this group as late as their forearm fixation was removed. The following indices and parameters were assessed in the early postoperative period (i.e. by 8 weeks after the fixation removal): wrist and fingers range of motion (ROM), hand grip strength (dynamometry), local swelling, pain, scores of a nine hole peg test (NHPT), and a DASH score. RESULTS After the fixation had been removed, the group I reported statistically significantly higher values of movement compared to the values of the contralateral limb in the following directions: dorsal flexion, palmar flexion, MP joints flexion, flexion of PIP joints (proximal interphalangeal), and flexion of DIP joints (distal interphalangeal). After eight weeks, the group I manifested significantly higher values in dorsal flexion, palmar flexion and ulnar deviation in the wrist. There were no significant differences in other movement directions. The hand grip strength mean value examined with a dynamometer was significantly higher in the group I in the sixth and eighth week of testing (group I - 58.9% strength of a healthy limb after six weeks, or 66.5% after eight weeks). The results in the group II were 49.9% strength of a healthy limb after six weeks, or 56.6% after eight weeks. The group I showed statistically significantly lower values of wrist swelling and higher finger dexterity in the NHPT in all measured weeks. Lower pain intensity in the group I during the measurements was observed. At the same time, this group showed significantly better results in the DASH score. DISCUSSION The results of this study are useful for clinical practice. They confirm a functional relation between the activity of hand muscles and the shoulder muscle activity. The differences in the functional ability of the hand and the functional state of the injured wrist were detected as early as in the early postoperative period. It could be stated that the tested subjects in the group I showed a greater and faster improvement in the physical function of the injured hand. This was also accompanied by a positive psychological effect. We had not found a study of a similar type in the available literature that we could have compared our submitted results to. CONCLUSIONS Shoulder girdle muscles exercises after a distal radius fracture, while wrist is immobilized, can evidently enhance functional capability and accelerate the hand-function restitution. Early functional outcomes of the injured wrist after the rehabilitation with shoulder girdle muscles exercises support the efficiency of this broadened rehabilitation protocol. Key words: distal radius frac,ture, hand, shoulder, functional treatment, rehabilitation.

Defects in cortical microarchitecture among African-American women with type 2 diabetes

PubMed Central

Yu, Elaine W.; Putman, Melissa S.; Derrico, Nicolas; Abrishamanian-Garcia, Gabriela; Finkelstein, Joel S.; Bouxsein, Mary L.

2015-01-01

Introduction/Purpose Fracture risk is increased in patients with type 2 diabetes mellitus (DM2) despite normal areal bone mineral density (aBMD). DM2 is more common in African-Americans than in Caucasians. It is not known whether African-American women with DM2 have deficits in bone microstructure. Methods We measured aBMD at the spine and hip by DXA, and volumetric BMD (vBMD) and microarchitecture at the distal radius and tibia by HR-pQCT in 22 DM2 and 78 non-diabetic African-American women participating in the Study of Women Across the Nation (SWAN). We also measured fasting glucose and HOMA-IR. Results Age, weight, and aBMD at all sites were similar in both groups. At the radius, cortical porosity was 26% greater, while cortical vBMD and tissue mineral density were lower in women with DM2 than in controls. There were no differences in radius total vBMD or trabecular vBMD between groups. Despite inferior cortical bone properties at the radius, FEA-estimated failure load was similar between groups. Tibia vBMD and microarchitecture were also similar between groups. There were no significant associations between cortical parameters and duration of DM2 or HOMA-IR. However, among women with DM2, higher fasting glucose levels were associated with lower cortical vBMD (r=−0.54, p=0.018). Conclusions DM2 and higher fasting glucose are associated with unfavorable cortical bone microarchitecture at the distal radius in African-American women. These structural deficits may contribute to the increased fracture risk among women with DM2. Further our results suggest that hyperglycemia may be involved in mechanisms of skeletal fragility associated with DM2. PMID:25398431

[Clinical observation on the effect of joint mobilization in treating elderly patients after distal radius fractures operation].

PubMed

Jia, Xue-Feng; Cai, Hong-Xin; Lin, Ge-Sheng; Fang, Ji-Shi; Wang, Yong; Wu, Zhi-Yong; Tu, Xu-Hui

2017-07-25

To investigate the effect of joint mobilization on postoperative wrist joint function, pain and grip strength for elderly patients with distal radius fracture. From January 2015 to June 2016, a total of 67 elderly patients with distal radius fracture were randomly divided into routine exercise group and joint mobilization group. Among them, 37 patients in the routine exercise group underwent conventional distal radius fracture postoperative joint function exercise regimen, including 16 males and 21 females with a mean age of (67.8±3.2) years old ranging from 60 to 72 years old;the injured side was dominant in 23 cases and non-dominant in 14 cases;injury mechanism was fall in 26 cases, traffic accident in 11 cases; for AO type, 6 cases were type B3, 18 cases were type C1, 7 cases were type C2, 6 cases was type C3. Other 30 patients in the joint mobilization group underwent joint mobilization on the basis of the routine exercise group including 14 males and 16 females with a mean age of (67.1±4.0) years old ranging from 61 to 74 years old; the injured side was dominant in 21 cases and non-dominant in 9 cases;injury mechanism was fall in 25 cases, traffic accident in 5 cases;for AO type, 8 cases were type B3, 13 cases were type C1, 6 cases were type C2, 9 cases were type C3. The wrist joint activity, Gartland-Werley wrist joint function score, VAS pain score and grip strength were observed at 3 months afrer treatment. After 3 months' treatment, the VAS in the routine exercise group was higher than that of the joint mobilization group ( P <0.05). The grip strength of affected side in both groups were lower than that of contralateral side, but the average grip strength of affected side in joint mobilization group was higher than that in routine exercise group( P <0.05). In routine exercise group, the average angle of flexion, extension, radial deviation were significantly higher than those of joint mobilization group( P <0.05). But ulnar deviation angle in routine exercise group compared with joint mobilization group had no significant difference ( P >0.05). In the comparison of each item of Gartland-Werley, there was no significant difference between two groups in residual deformity and complication( P >0.05); the average score of subjective score, objective score and total score in routine exercise group were significantly higher than those of the joint mobilization group ( P <0.05). The wrist function Gartland-Werley score in routine exercise group after treatment was excellent in 21 cases, good in 10, 6 in fair, while in joint mobilization group, excellent in 23, good in 6, fair in 1( P <0.05). The application of joint mobilization in the treatment of elderly patients with distal radius fracture can improve the joint activity and obtain better wrist function after surgery.

Association of larger holes in the trabecular bone at the distal radius in postmenopausal women with type 2 diabetes mellitus compared to controls.

PubMed

Pritchard, Janet M; Giangregorio, Lora M; Atkinson, Stephanie A; Beattie, Karen A; Inglis, Dean; Ioannidis, George; Punthakee, Zubin; Adachi, J D; Papaioannou, Alexandra

2012-01-01

Adults with type 2 diabetes mellitus (DM) have an elevated fracture risk despite normal areal bone mineral density (aBMD). The study objective was to compare trabecular bone microarchitecture of postmenopausal women with type 2 DM and women without type 2 DM. An extremity 1T magnetic resonance imaging system was used to acquire axial images (195 × 195 × 1,000 μm(3) voxel size) of the distal radius of women recruited from outpatient clinics or by community advertisement. Image segmentation yielded geometric, topologic, and stereologic outcomes, i.e., number and size of trabecular bone network holes (marrow spaces), endosteal area, trabecular bone volume fraction, nodal and branch density, and apparent trabecular thickness, separation, and number. Lumbar spine (LS) and proximal femur BMD were measured with dual x-ray absorptiometry. Microarchitectural differences were assessed using linear regression and adjusted for percent body fat, ethnicity, timed up-and-go test, Charlson Index, and calcium and vitamin D intake; aBMD differences were adjusted for body mass index (BMI). Women with type 2 DM (n = 30, mean ± SD age 71.0 ± 4.8 years) had larger holes (+13.3%; P = 0.001) within the trabecular bone network than women without type 2 DM (n = 30, mean ± SD age 70.7 ± 4.9 years). LS aBMD was greater in women with type 2 DM; however, after adjustment for BMI, LS aBMD did not differ between groups. In women with type 2 DM, the average hole size within the trabecular bone network at the distal radius is greater compared to controls. This may explain the elevated fracture risk in this population. Copyright © 2012 by the American College of Rheumatology.

Association between individual DASH tasks and restricted wrist flexion and extension after volar plate fixation of a fracture of the distal radius.

PubMed

Bot, Arjan G J; Souer, J Sebastiaan; van Dijk, C Niek; Ring, David

2012-12-01

Symptoms and psychosocial factors are suggested to account for more of the variation in disability than physical impairment, but perhaps less so at the level of specific tasks. This study assessed the influence of impaired wrist motion on specific tasks on the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. Sixty-three patients with an operatively treated fracture of the distal radius completed the Pain Catastrophizing Scale (PCS), Pain Anxiety Symptoms Scale, and Center for Epidemiologic Studies Depression Scale (CES-D) just before surgery and the DASH questionnaire 3 months after surgery. Nine questions on the DASH were selected as potentially sensitive to changes in wrist motion and evaluated in bivariate and multivariable analyses. In multivariable models of factors associated with specific tasks, only "Open a tight or new jar" was affected by wrist flexion and PCS accounting for 33 % of the variation. Motion, pain, and PCS were significant predictors of the DASH score. Among the eight tasks not related to wrist motion, 33 % of the variation in disability with writing was accounted for by PCS and limb dominance; 20 % of disability preparing a meal by pain, CES-D, and PCS; 14 % of disability with making a bed by pain and CES-D; and 23 % of changing a light bulb overhead by age, pain, and fracture type. After volar plate fixation of a fracture of the distal radius, upper extremity disability based on select items from the DASH questionnaire correlated minimally with impairment of wrist motion, even at the level of specific tasks. Prognostic Level II.

Epidemiology of distal radius fractures in polytrauma patients and the influence of high traumatic energy transfer.

PubMed

Ferree, Steven; van der Vliet, Quirine M J; Nawijn, Femke; Bhashyam, Abhiram R; Houwert, Roderick M; Leenen, Luke P H; Hietbrink, Falco

2018-03-01

For several extremity fractures differences in morphology, incidence rate and functional outcome were found when polytrauma patients were compared to patients with an isolated injury. This is not proven for distal radius fractures (DRF). Therefore, this study aimed to analyse fracture morphology in relation to energy transfer in both poly- and mono-trauma patients with a DRF. This was a retrospective cohort study. All patients aged 16 years and older with a DRF were included. Patients with an Injury Severity Score of 16 or higher were classified as polytrauma patients. Injuries were defined as high or low energy. All DRFs were classified using the AO/OTA fracture classification system. A total of 830 patients with a DRF were included, 12% were polytrauma. The incidence rate of DRF in polytrauma patients was 3.5%. Ipsilateral upper extremity injury was found in >30% of polytrauma and high-energy monotrauma patients, compared to 5% in low-energy monotrauma patients. More type C DRF were found in polytrauma and high-energy monotrauma patients versus low-energy monotrauma patients. Operative intervention rates for all types of DRF were similar for polytrauma and high-energy monotrauma patients. Non-union rates were higher in polytrauma patients. Higher energy mechanisms of injury, in polytrauma and high-energy monotrauma patients, were associated with more severe complex articular distal radius fractures and more ipsilateral upper extremity injuries. Polytrauma and high-energy monotrauma patient have a similar fracture morphology. However, polytrauma patients have in addition to more injured body regions also more non-union related interventions than high-energy monotrauma patients. Copyright © 2018 Elsevier Ltd. All rights reserved.

Systematic review of outcomes following fixed angle intramedullary fixation of distal radius fractures.

PubMed

Hardman, John; Al-Hadithy, Nawfal; Hester, Thomas; Anakwe, Raymond

2015-12-01

There remains little consensus regarding the optimal management of distal radius fractures. Fixed angle volar devices have gained recent popularity, but have also been associated with soft tissue complications. Intramedullary (IM) devices offer fixed angle stabilisation with minimally invasive surgical technique and low, IM profile. No formal review of outcomes could be identified. We conducted a systematic review of clinical studies regarding the use of fixed angle IM devices in acute extra-articular or simple intra-articular distal radius fractures. Preferred Reporting Items for Systematic Reviews (PRISMA) guidance was followed. Numerical data regarding functional scores, ranges of movement, radiological outcomes and complications were pooled to produce aggregate means and standard deviation. A total of 310 titles and abstracts were identified. Fourteen papers remained for analysis. Total patient number was 357, mean age 63.72 years and mean follow-up 12.77 months. Mean functional scores were all rated as 'excellent'. Aggregate means: flexion 53.62°, extension 56.38°, pronation 69.10°, supination 70.29°, ulnar deviation 28.35°, radial deviation 18.12°, radial height 8.98 mm, radial inclination 16.51°, volar tilt 5.35°, ulnar variance 0.66 mm and grip strength 90.37 %. Overall complication rate was 19.6 %. Tendon rupture was unreported. Tendon irritation was 0.88 %. Radial nerve paraesthesia was 11.44 %. Fixed angle IM devices facilitate excellent functional outcomes, with radiological and clinical parameters at least equivalent to volar plate devices. Low rates of tendon irritation and absence of tendon rupture are advantageous. Significant limitations include a lack of application for complex articular injuries and the propensity to cause a transient neuritis of the superficial branch of the radial nerve.

Recommendation for measuring clinical outcome in distal radius fractures: a core set of domains for standardized reporting in clinical practice and research.

PubMed

Goldhahn, Jörg; Beaton, Dorcas; Ladd, Amy; Macdermid, Joy; Hoang-Kim, Amy

2014-02-01

Lack of standardization of outcome measurement has hampered an evidence-based approach to clinical practice and research. We adopted a process of reviewing evidence on current use of measures and appropriate theoretical frameworks for health and disability to inform a consensus process that was focused on deriving the minimal set of core domains in distal radius fracture. We agreed on the following seven core recommendations: (1) pain and function were regarded as the primary domains, (2) very brief measures were needed for routine administration in clinical practice, (3) these brief measures could be augmented by additional measures that provide more detail or address additional domains for clinical research, (4) measurement of pain should include measures of both intensity and frequency as core attributes, (5) a numeric pain scale, e.g. visual analogue scale or visual numeric scale or the pain subscale of the patient-reported wrist evaluation (PRWE) questionnaires were identified as reliable, valid and feasible measures to measure these concepts, (6) for function, either the Quick Disability of the arm, shoulder and hand questionnaire or PRWE-function subscale was identified as reliable, valid and feasible measures, and (7) a measure of participation and treatment complications should be considered core outcomes for both clinical practice and research. We used a sound methodological approach to form a comprehensive foundation of content for outcomes in the area of distal radius fractures. We recommend the use of symptom and function as separate domains in the ICF core set in clinical research or practice for patients with wrist fracture. Further research is needed to provide more definitive measurement properties of measures across all domains.

High-resolution-cone beam tomography analysis of bone microarchitecture in patients with acromegaly and radiological vertebral fractures.

PubMed

Maffezzoni, Filippo; Maddalo, Michele; Frara, Stefano; Mezzone, Monica; Zorza, Ivan; Baruffaldi, Fabio; Doglietto, Francesco; Mazziotti, Gherardo; Maroldi, Roberto; Giustina, Andrea

2016-11-01

Vertebral fractures are an emerging complication of acromegaly but their prediction is still difficult occurring even in patients with normal bone mineral density. In this study we evaluated the ability of high-resolution cone-beam computed tomography to provide information on skeletal abnormalities associated with vertebral fractures in acromegaly. 40 patients (24 females, 16 males; median age 57 years, range 25-72) and 21 healthy volunteers (10 females, 11 males; median age 60 years, range: 25-68) were evaluated for trabecular (bone volume/trabecular volume ratio, mean trabecular separation, and mean trabecular thickness) and cortical (thickness and porosity) parameters at distal radius using a high-resolution cone-beam computed tomography system. All acromegaly patients were evaluated for morphometric vertebral fractures and for mineral bone density by dual-energy X-ray absorptiometry at lumbar spine, total hip, femoral neck, and distal radius. Acromegaly patients with vertebral fractures (15 cases) had significantly (p < 0.05) lower bone volume/trabecular volume ratio, greater mean trabecular separation, and higher cortical porosity vs. nonfractured patients, without statistically significant differences in mean trabecular thickness and cortical thickness. Fractured and nonfractured acromegaly patients did not have significant differences in bone density at either skeletal site. Patients with acromegaly showed lower bone volume/trabecular volume ratio (p = 0.003) and mean trabecular thickness (p < 0.001) and greater mean trabecular separation (p = 0.02) as compared to control subjects, without significant differences in cortical thickness and porosity. This study shows for the first time that abnormalities of bone microstructure are associated with radiological vertebral fractures in acromegaly. High-resolution cone-beam computed tomography at the distal radius may be useful to evaluate and predict the effects of acromegaly on bone microstructure.

Assessment of "YouTube" Content for Distal Radius Fracture Immobilization.

PubMed

Addar, Abdullah; Marwan, Yousef; Algarni, Nizar; Berry, Gregory

Distal radius fractures (DRFs) are the most common orthopedic fractures, with >70% of cases treated by closed immobilization using a short arm cast or a sugar tong splint. However, inadequate immobilization is a risk factor for loss of reduction requiring repeat reduction or surgical treatment. Therefore, education of clinical skills for appropriate immobilization of DRFs is important. With the increasing use of web-based information by medical learners, our aim was to assess the quality and quantity of videos regarding closed immobilization of DRFs on YouTube. Retrospective review of YouTube videos on distal radius fracture immobilization using specific search terms. Identified videos were analyzed for their educational value, quality of the technical skill demonstrated, and overall metrics. Educational value was scored on a 5-point scale, with "1" indicative of low quality and "5" of high quality. Not applicable. Among the 68,366 videos identified, 16 met our inclusion criteria of being in English; performed by a health care professional or institution; and with casting being the major theme of the educational information provided. Of these 16 videos, 6 had an educational value score of 4 or 5, with the remaining 10 having a score ≤3. Although immobilization was demonstrated by cast technician specialized in orthopedics, skills were also performed by orthopedic attendants, urgent care physicians, orthopedic residents, and nurse practitioners. The credentials of the performer in 3 videos were not identified. There is a need to promote high-quality educational videos produced by established medical school faculty members on open, web-based, portals. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Effect of facility on the operative costs of distal radius fractures.

PubMed

Mather, Richard C; Wysocki, Robert W; Mack Aldridge, J; Pietrobon, Ricardo; Nunley, James A

2011-07-01

The purpose of this study was to investigate whether ambulatory surgery centers can deliver lower-cost care and to identify sources of those cost savings. We performed a cost identification analysis of outpatient volar plating for closed distal radius fractures at a single academic medical center. Multiple costs and time measures were taken from an internal database of 130 consecutive patients and were compared by venue of treatment, either an inpatient facility or an ambulatory, stand-alone surgery facility. The relationships between total cost and operative time and multiple variables, including fracture severity, patient age, gender, comorbidities, use of bone graft, concurrent carpal tunnel release, and surgeon experience, were examined, using multivariate analysis and regression modeling to identify other cost drivers or explanatory variables. The mean operative cost was considerably greater at the inpatient facility ($7,640) than at the outpatient facility ($5,220). Cost drivers of this difference were anesthesia services, post-anesthesia care unit, and operating room costs. Total surgical time, nursing time, set-up, and operative times were 33%, 109%, 105%, and 35% longer, respectively, at the inpatient facility. There was no significant difference between facilities for the additional variables, and none of those variables independently affected cost or operative time. The only predictor of cost and time was facility type. This study supports the use of ambulatory stand-alone surgical facilities to achieve efficient resource utilization in the operative treatment of distal radius fractures. We also identified several specific costs and time measurements that differed between facilities, which can serve as potential targets for tertiary facilities to improve utilization. Economic and Decisional Analysis III. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Limited arthrodesis of the wrist for treatment of giant cell tumor of the distal radius.

PubMed

Flouzat-Lachaniette, Charles-Henri; Babinet, Antoine; Kahwaji, Antoine; Anract, Philippe; Biau, David-Jean

2013-08-01

To present the functional results of a technique of radiocarpal arthrodesis and reconstruction with a structural nonvascularized autologous bone graft after en bloc resection of giant cell tumors of the distal radius. A total of 13 patients with a mean age of 37 years with aggressive giant cell tumor (Campanacci grade III) of distal radius were managed with en bloc resection and reconstruction with a structural nonvascularized bone graft. The primary outcome measure was the disability evaluated by the Musculoskeletal Tumor Society rating score of limb salvage. Secondary outcomes included survival of the reconstruction measured from the date of the operation to revision procedure for any reason (mechanical, infectious, or oncologic). Other outcomes included active wrist motion and ability to resume work. Mean follow-up period was 6 years (range, 2-14 y). The median arc of motion at the midcarpal joint was 40°, median wrist flexion was 20°, and median extension was 10°. The median Musculoskeletal Tumor Society score based on the analysis of factors pertinent to the patient as a whole (pain, functional activities, and emotional acceptance) and specific to the upper limb (positioning of the hand, manual dexterity, and lifting ability) was 86%. Five patients underwent a second surgical procedure. The cumulative probability of reoperation for mechanical reason was 31% at similar follow-up times at 2, 5, and 10 years. This technique provided a stable wrist and partially restored wrist motion with limited pain. However, further surgical procedures may be necessary to reach this goal. Therapeutic IV. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Assessment of skeletal maturity in scoliosis patients to determine clinical management: a new classification scheme using distal radius and ulna radiographs.

PubMed

Luk, Keith D K; Saw, Lim Beng; Grozman, Samuel; Cheung, Kenneth M C; Samartzis, Dino

2014-02-01

Assessment of skeletal maturity in patients with adolescent idiopathic scoliosis (AIS) is important to guide clinical management. Understanding growth peak and cessation is crucial to determine clinical observational intervals, timing to initiate or end bracing therapy, and when to instrument and fuse. The commonly used clinical or radiologic methods to assess skeletal maturity are still deficient in predicting the growth peak and cessation among adolescents, and bone age is too complicated to apply. To address these concerns, we describe a new distal radius and ulna (DRU) classification scheme to assess skeletal maturity. A prospective study. One hundred fifty young, female AIS patients with hand x-rays and no previous history of spine surgery from a single institute were assessed. Radius and ulna plain radiographs, and various anthropomorphic parameters were assessed. We identified various stages of radius and ulna epiphysis maturity, which were graded as R1-R11 for the radius and U1-U9 for the ulna. The bone age, development of sexual characteristics, standing height, sitting height, arm span, radius length, and tibia length were studied prospectively at each stage of these epiphysis changes. Standing height, sitting height, and arm span growth were at their peak during stages R7 (mean, 11.4 years old) and U5 (mean, 11.0 years old). The long bone growths also demonstrated a common peak at R7 and U5. Cessation of height and arm span growth was noted after stages R10 (mean, 15.6 years old) and U9 (mean, 17.3 years old). The new DRU classification is a practical and easy-to-use scheme that can provide skeletal maturation status. This classification scheme provides close relationship with adolescent growth spurt and cessation of growth. This classification may have a tremendous utility in improving clinical-decision making in the conservative and operative management of scoliosis patients. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of oral monthly ibandronate on bone microarchitecture in women with osteopenia-a randomized placebo-controlled trial.

PubMed

Chapurlat, R D; Laroche, M; Thomas, T; Rouanet, S; Delmas, P D; de Vernejoul, M-C

2013-01-01

We have examined the effect of oral monthly ibandronate on distal radius and tibia microarchitecture with high-resolution peripheral quantitative tomography compared with placebo, in women with osteopenia, and found that ibandronate did not significantly affect trabecular bone but improved cortical density and thickness at the tibia. We have examined the effect of ibandronate on bone microarchitecture with peripheral high-resolution quantitative computed tomography (HR-pQCT) in a randomized placebo-controlled trial among 148 women with osteopenia. Patients received either oral 150 mg monthly ibandronate or placebo over 24 months. Bone microarchitecture was assessed at baseline, 6, 12, and 24 months, using HR-pQCT at the distal radius and tibia; areal bone mineral density (aBMD) was measured with DXA at the spine, hip, and radius. At 12 months, there was no significant difference in trabecular bone volume at the radius (the primary end point) between women on ibandronate (10.8 ± 2.5%) and placebo (10.5 ± 2.9%), p = 0.25. There was no significant difference in other radius trabecular and cortical microarchitecture parameters at 12 and 24 months. In contrast, at the tibia, cortical vBMD in the ibandronate group was significantly greater than in the placebo group at 6, 12, and 24 months, with better cortical thickness at 6, 12, and 24 months. With ibandronate, aBMD was significantly increased at the hip and spine at 12 and 24 months but at the radius was significantly superior to placebo only at 24 months. Most of the adverse events related to ibandronate were expected with bisphosphonate use, and none of them were serious. We conclude that 12 months of treatment with ibandronate in women with osteopenia did not affect trabecular bone microarchitecture, but improved cortical vBMD at the tibia at 12 and 24 months, and preserved cortical thickness at the tibia.

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

PubMed

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

2011-02-01

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

[Fracture of the diaphyseal radius during Cyr wheel practice - an uncommon injury of wheel gymnastics].

PubMed

Kauther, M D; Rummel, S; Hussmann, B; Lendemans, S; Nast-Kolb, D; Wedemeyer, C

2011-12-01

The cyr wheel is a modified gymnastic wheel with only one ring that can lead to extreme forces on the gymnast. We report on a distal radius shaft fracture (AO 22 A 2.1) and a fracture of the styloid process of the ulna that occurred after holding on to a slipping Cyr wheel and exposition to high pressure on the lower arm. The fracture was fixed by screws and a plate. © Georg Thieme Verlag KG Stuttgart · New York.

77 FR 35978 - Johnson & Johnson and Synthes, Inc.; Analysis of Agreement Containing Consent Orders to Aid...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-15

... the most common fractures in the human body. Distal radius fractures generally occur as a result of an... comprehensive and broad-based manufacturer of products related to all aspects of human health care. In 2011, J&J...

Arthroscopic study of injuries in articular fractures of distal radius extremity

PubMed Central

Araf, Marcelo; Mattar, Rames

2014-01-01

OBJECTIVE: To analyze the incidence of wrist ligament and cartilage associated fractures of the distal radius, through arthroscopy, correlating with AO/ASIF classification. METHODS: Thirty patients aged between 20 and 50 years old, with closed fracture from groups B and C according to AO/ASIF classification were selected. All of them were submitted to wrist arthroscopy to address intra-articular injuries and reduction and osteosynthesis of the fracture. RESULTS: A high incidence of intra-articular injuries was noticed, and 76.6% of them presented injury of the triangular fibrocartilage complex, 36.6% of the intrinsic scapholunate ligament, 6.6% of the intrinsic triquetrolunate ligament, and 33% articular cartilage injury larger than three millimeters. Patients with fractures from type C according to AO/ASIF classification presented a higher incidence of ligament injuries. CONCLUSION: There is no relationship between the presence of chondral injury and the AO/ASIF classification of the fractures in the cases reported in this study. Level of Evidence III, Non Randomized Controlled Trial. PMID:25061421

Does bone measurement on the radius indicate skeletal status. Concise communication

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

Mazess, R.B.; Peppler, W.W.; Chesney, R.W.

1984-03-01

Single-photon (I-125) absorptiometry was used to measure bone mineral content (BMC) of the distal third of the radius, and dual-photon absorptiometry (Gd-153) was used to measure total-body bone mineral (TBBM), as well as the BMC of major skeletal regions. Measurements were done in normal females, normal males, osteoporotic females, osteoporotic males, and renal patients. The BMC of the radius predicted TBBM well in normal subjects, but was less satisfactory in the patient groups. The spinal BMC was predicted with even lower accuracy from radius measurement. The error in predicting areal density (bone mass per unit projected skeletal area) of themore » lumbar and thoracic spine from the radius BMC divided by its width was smaller, but the regressions differed significantly among normals, osteoporotics, and renal patients. There was a preferential spinal osteopenia in the osteoporotic group and in about half of the renal patients. Bone measurements on the radius can indicate overall skeletal status in normal subjects and to a lesser degree in patients, but these radius measurements are inaccurate, even on the average, as an indicator of spinal state.« less

[Clinical Efficacy of Supplementary Treatment of Gukang Capsules to the Elder Patients with Fracture of Distal Radius].

PubMed

Wang, Wei; Liao, Su-ping; Wei, Lei

2015-01-01

To study the clinical efficacy of supplementary treatment of tukang Capsules to the elder patients with fracture of the distal radius. A total of 108 elder patients with fracture of the distal radius diagnosed by X-ray,who visited orthopedics department of Pu' ai Hospital in January 2012 - December 2013, were randomly divided into observation group and control group. Cases in both groups received the operation of internal fixation by T-type plate. Cases in control group received oral Calcium Carbonate Tablets, and cases in observation group received Gukang Capsules besides Calcium Carbonate Tablets. Treatment duration was four weeks. The painful and swelling degree of wrist joints, levels of type I propeptide carboxy-terminal procollagen (P I CP) and bone glaprotein(BGP) in serum were compared. Hospitalization and fracture healing time, as well as recovery condition of wrist joints in the sixth month after operation were compared. The VAS of both groups was not significantly different before operation and in the 28th day after operation(P >0. 05), but the VAS in observation group was significantly lower than that in control group in the 3rd,5th, 7th, 14th and 21th day after operation(P <0. 01). The swelling scale of both groups was not significantly different before operation and in the 28th day after operation(P >0. 05), but the swelling scale in observation group was significantly lower than that in control group in the 3rd, 5th, 7th, 14th and 21th day after operation(P <0. 01). The levels of P I CP and BGP in serum of both groups were not significantly different before operation(P >0. 05), but the levels of P I CP and BGP in serum of observation groups were significantly higher than that in control group one and two months after operation (P <0. 01). Hospitalization and fracture healing time in observation group was significantly shortened compared with control group (P <0. 05). The effective ratio in observation group was 79. 63%, significantly higher than that in control group (P <0. 05). Gukang Capsules supplementary to internal fixation by T-type plate has favorable efficacy to fracture of the distal radius, which can reduce pain and swelling, increase levels of P I CP and BGP in serum, as well as promote the heal of fracture and recovery of wrist joints function.

Superradiance of charged black holes in Einstein–Gauss–Bonnet gravity

NASA Astrophysics Data System (ADS)

Fierro, Octavio; Grandi, Nicolás; Oliva, Julio

2018-05-01

In this paper we show that electrically charged black holes in Einstein–Gauss–Bonnet gravity suffer from a superradiant instability. It is triggered by a charged scalar field that fulfils Dirichlet boundary conditions at a mirror located outside the horizon. As in general relativity, the unstable modes exist provided that the mirror is located beyond a critical radius, making the instability a long wavelength one. We explore the effects of the Gauss–Bonnet corrections on the critical radius and find evidence that the critical radius decreases as the Gauss–Bonnet coupling α increases. Due to the, up to date, lack of an analytic rotating solution for Einstein–Gauss–Bonnet theory, this is the first example of a superradiant instability in the presence of higher curvature terms in the action.

Biomechanical evaluation of fixation of intra-articular fractures of the distal part of the radius in cadavera: Kirschner wires compared with calcium-phosphate bone cement.

PubMed

Yetkinler, D N; Ladd, A L; Poser, R D; Constantz, B R; Carter, D

1999-03-01

The purpose of this study was to compare the biomechanical efficacy of an injectable calcium-phosphate bone cement (Skeletal Repair System [SRS]) with that of Kirschner wires for the fixation of intraarticular fractures of the distal part of the radius. Colles fractures (AO pattern, C2.1) were produced in ten pairs of fresh-frozen human cadaveric radii. One radius from each pair was randomly chosen for stabilization with SRS bone cement. These ten radii were treated with open incision, impaction of loose cancellous bone with use of a Freer elevator, and placement of the SRS bone cement by injection. In the ten control specimens, the fracture was stabilized with use of two horizontal and two oblique Kirschner wires. The specimens were cyclically loaded to a peak load of 200 newtons for 2000 cycles to evaluate the amount of settling, or radial shortening, under conditions simulating postoperative loading with the limb in a cast. Each specimen then was loaded to failure to determine its ultimate strength. The amount of radial shortening was highly variable among the specimens, but it was consistently higher in the Kirschner-wire constructs than in the bone fixed with SRS bone cement within each pair of radii. The range of shortening for all twenty specimens was 0.18 to 4.51 millimeters. The average amount of shortening in the SRS constructs was 50 percent of that in the Kirschner-wire constructs (0.51+/-0.34 compared with 1.01+/-1.23 millimeters; p = 0.015). With the numbers available, no significant difference in ultimate strength was detected between the two fixation groups. This study showed that fixation of an intra-articular fracture of the distal part of a cadaveric radius with biocompatible calcium-phosphate bone cement produced results that were biomechanically comparable with those produced by fixation with Kirschner wires. However, the constructs that were fixed with calcium-phosphate bone cement demonstrated less shortening under simulated cyclic load-bearing.

Axisymmetric annular curtain stability

NASA Astrophysics Data System (ADS)

Ahmed, Zahir U.; Khayat, Roger E.; Maissa, Philippe; Mathis, Christian

2012-06-01

A temporal stability analysis was carried out to investigate the stability of an axially moving viscous annular liquid jet subject to axisymmetric disturbances in surrounding co-flowing viscous gas media. We investigated in this study the effects of inertia, surface tension, the gas-to-liquid density ratio, the inner-to-outer radius ratio and the gas-to-liquid viscosity ratio on the stability of the jet. With an increase in inertia, the growth rate of the unstable disturbances is found to increase. The dominant (or most unstable) wavenumber decreases with increasing Reynolds number for larger values of the gas-to-liquid viscosity ratio. However, an opposite tendency for the most unstable wavenumber is predicted for small viscosity ratio in the same inertia range. The surrounding gas density, in the presence of viscosity, always reduces the growth rate, hence stabilizing the flow. There exists a critical value of the density ratio above which the flow becomes stable for very small viscosity ratio, whereas for large viscosity ratio, no stable flow appears in the same range of the density ratio. The curvature has a significant destabilizing effect on the thin annular jet, whereas for a relatively thick jet, the maximum growth rate decreases as the inner radius increases, irrespective of the surrounding gas viscosity. The degree of instability increases with Weber number for a relatively large viscosity ratio. In contrast, for small viscosity ratio, the growth rate exhibits a dramatic dependence on the surface tension. There is a small Weber number range, which depends on the viscosity ratio, where the flow is stable. The viscosity ratio always stabilizes the flow. However, the dominant wavenumber increases with increasing viscosity ratio. The range of unstable wavenumbers is affected only by the curvature effect.

Fast estimation of Colles' fracture load of the distal section of the radius by homogenized finite element analysis based on HR-pQCT.

PubMed

Hosseini, Hadi S; Dünki, Andreas; Fabech, Jonas; Stauber, Martin; Vilayphiou, Nicolas; Pahr, Dieter; Pretterklieber, Michael; Wandel, Jasmin; Rietbergen, Bert van; Zysset, Philippe K

2017-04-01

Fractures of the distal section of the radius (Colles' fractures) occur earlier in life than other osteoporotic fractures. Therefore, they can be interpreted as a warning signal for later, more deleterious fractures of vertebral bodies or the femoral neck. In the past decade, the advent of HR-pQCT allowed a detailed architectural analysis of the distal radius and an automated but time-consuming estimation of its strength with linear micro-finite element (μFE) analysis. Recently, a second generation of HR-pQCT scanner (XtremeCT II, SCANCO Medical, Switzerland) with a resolution beyond 61 μm became available for even more refined biomechanical investigations in vivo. This raises the question how biomechanical outcome variables compare between the original (LR) and the new (HR) scanner resolution. Accordingly, the aim of this work was to validate experimentally a patient-specific homogenized finite element (hFE) analysis of the distal section of the human radius for the fast prediction of Colles' fracture load based on the last generation HR-pQCT. Fourteen pairs of fresh frozen forearms (mean age = 77.5±9) were scanned intact using the high (61 μm) and the low (82 μm) resolution protocols that correspond to the new and original HR-pQCT systems. From each forearm, the 20mm most distal section of the radius were dissected out, scanned with μCT at 16.4 μm and tested experimentally under compression up to failure for assessment of stiffness and ultimate load. Linear and nonlinear hFE models together with linear micro finite element (μFE) models were then generated based on the μCT and HR-pQCT reconstructions to predict the aforementioned mechanical properties of 24 sections. Precision errors of the short term reproducibility of the FE analyses were measured based on the repeated scans of 12 sections. The calculated failure loads correlated strongly with those measured in the experiments: accounting for donor as a random factor, the nonlinear hFE provided a marginal coefficient of determination (R m 2 ) of 0.957 for the high resolution (HR) and 0.948 for the low resolution (LR) protocols, the linear hFE with R m 2 of 0.957 for the HR and 0.947 for the LR protocols. Linear μFE predictions of the ultimate load were similar with an R m 2 of 0.950 for the HR and 0.954 for the LR protocols, respectively. Nonlinear hFE strength computation led to precision errors of 2.2 and 2.3% which were higher than the ones calculated based on the linear hFE (1.6 and 1.9%) and linear μFE (1.2 and 1.6%) for the HR and LR protocols respectively. Computation of the fracture load with nonlinear hFE demanded in average 6h of CPU time which was 3 times faster than with linear μFE, while computation with linear hFE took only a few minutes. This study delivers an extensive experimental and numerical validation for the application of an accurate and fast hFE diagnostic tool to help in identifying individuals who may be at risk of an osteoporotic wrist fracture and to follow up pharmacological and other treatments in such patients. Copyright © 2017 Elsevier Inc. All rights reserved.

[Secondary tendon reconstruction on the thumb].

PubMed

Bickert, B; Kremer, T; Kneser, U

2016-12-01

Closed tendon ruptures of the thumb that require secondary reconstruction can affect the extensor pollicis longus (EPL), extensor pollicis brevis (EPB) and flexor pollicis longus (FPL) tendons. Treatment of rupture of the EPB tendon consists of refixation to the bone and temporary transfixation of the joint. In the case of preexisting or posttraumatic arthrosis, definitive arthrodesis of the thumb is the best procedure. Closed ruptures of the EPL and FPL tendons at the wrist joint cannot be treated by direct tendon suture. Rupture of the EPL tendon occurs after distal radius fractures either due to protruding screws or following conservative treatment especially in undisplaced fractures. Transfer of the extensor indicis tendon to the distal EPL stump is a good option and free interposition of the palmaris longus tendon is a possible alternative. The tension should be adjusted to slight overcorrection, which can be checked intraoperatively by performing the tenodesis test. Closed FPL ruptures at the wrist typically occur 3-6 months after osteosynthesis of distal radius fractures with palmar plates and are mostly characterized by crepitation and pain lasting for several weeks. They can be prevented by premature plate removal, synovectomy and carpal tunnel release. For treatment of a ruptured FPL tendon in adult patients the options for tendon reconstruction should be weighed up against the less complicated tenodesis or arthrodesis of the thumb interphalangeal joint.

Longitudinal instability of the forearm.

PubMed

Phadnis, J; Watts, A C

2016-10-01

The Essex Lopresti lesion is a rare triad of injury to the radial head, interosseous membrane of the forearm and distal radio-ulnar joint, which results in longitudinal instability of the radius. If unrecognized this leads to chronic pain and disability which is difficult to salvage. Early recognition and appropriate treatment is therefore desirable to prevent long-term problems. The aim of this article is to review the pathoanatomy of longitudinal radius instability and use the existing literature and authors' experience to provide recommendations for recognition and treatment of acute and chronic forearm instability, including description of the author's technique for interosseous membrane reconstruction.

Distal radius: anatomical morphometric gender characteristics. Do anatomical pre-shaped plates pay attention on it?

PubMed

Oppermann, Johannes; Bredow, Jan; Beyer, Frank; Neiss, Wolfram Friedrich; Spies, Christian K; Eysel, Peer; Dargel, Jens; Wacker, Max

2015-01-01

The purpose of the study was to investigate differences in the osseous structure anatomy of male and female distal radii. Morphometric data were obtained of 49 distal human cadaveric radii. An imprint of the distal edge was attained using silicone mass and the palmar cortical angle (PCA) of the lateral and intermediate column, here declared as medial, according to the concept of Rikli and Rigazzoni. The lateral and medial length and five widths were digitally measured by three observers. In order to compare the measurements an unpaired t test was used. To prove the reliability of the measurements an intraclass correlation analyses was done. Overall mean medial PCA was 148.25° (SD ± 6.83) and mean lateral PCA 156.07° (SD ± 7.00). In male specimens, the mean medial PCA was 147.38° (SD ± 6.01) and mean lateral PCA was 153.6° (SD ± 6.20) whereas in female specimens, the mean medial PCA was 149.41° (SD ± 7.79) and the mean lateral PCA 159.37° (SD ± 6.78), with statistical significance for the female lateral PCA. No gender significant difference for the medial PCA and no significant side difference for the PCA's could be found. The ICC of the observers was r = 0.936 and 0.976 for the medial and for lateral PCA 0.957-0.984. The palmar cortical length of the distal radius was significantly longer in male specimens. For all widths, larger values for male radii were measured, being statistically significant in all cases. Male dimensions concerning the wide were significantly larger when compared with females. Regarding the PCA at the medial and lateral column, we found significant difference for lateral PCA concerning the gender. Overall, study results demonstrated an angle of 148.25° ± 6.83 for the medial PCA and 156.07° ± 7.00 for the lateral PCA.

WHAT IS THE BEST RADIOGRAPHIC VIEW FOR “DIE PUNCH” DISTAL RADIUS FRACTURES? A CADAVER MODEL STUDY

PubMed Central

Falcochio, Diego Figueira; Crepaldi, Bruno Eiras; Trindade, Christiano Augusto; da Costa, Antonio Carlos; Chakkour, Ivan

2015-01-01

Objective: the aim of this study is try to show the best view for distal radius fractures so called die-punch fractures. Methods: There has been used a human cadaver radius bone from the Salvador Arena Tissue Bank. This bone was cleaned up after removing the soft tissues and osteotomies created displaced lunate fossa fractures of 0, 1, 2, 3 and 5 mm. We have fixed this fragment with adhesive tape. Then the joint deviation were significantly increased with step-offs of 1 mm. Radiographs were then taken into 5 different positions: postero-anterior view, lateral view, oblique views and tangencial view for each of the deviations. The resulting lunate fossa depression in each X-ray film was analyzed by the AutoCAD 2010® software. Results: The tangencial view was the best one to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees. The pronated oblique view was the best to see the 2mm degrees and the oblique supinated view wasn't able to see the degrees between 1 and 2mm. Conclusion: The tangencial view was the best one to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees. PMID:27027079

WHAT IS THE BEST RADIOGRAPHIC VIEW FOR "DIE PUNCH" DISTAL RADIUS FRACTURES? A CADAVER MODEL STUDY.

PubMed

Falcochio, Diego Figueira; Crepaldi, Bruno Eiras; Trindade, Christiano Augusto; da Costa, Antonio Carlos; Chakkour, Ivan

2012-01-01

the aim of this study is try to show the best view for distal radius fractures so called die-punch fractures. There has been used a human cadaver radius bone from the Salvador Arena Tissue Bank. This bone was cleaned up after removing the soft tissues and osteotomies created displaced lunate fossa fractures of 0, 1, 2, 3 and 5 mm. We have fixed this fragment with adhesive tape. Then the joint deviation were significantly increased with step-offs of 1 mm. Radiographs were then taken into 5 different positions: postero-anterior view, lateral view, oblique views and tangencial view for each of the deviations. The resulting lunate fossa depression in each X-ray film was analyzed by the AutoCAD 2010® software. The tangencial view was the best one to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees. The pronated oblique view was the best to see the 2mm degrees and the oblique supinated view wasn't able to see the degrees between 1 and 2mm. The tangencial view was the best one to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees.

Fixation Options for the Volar Lunate Facet Fracture: Thinking Outside the Box.

PubMed

Harness, Neil G

2016-03-01

Background Fractures of the distal radius with small volar ulnar marginal fracture fragments are difficult to stabilize with standard volar locking plates. The purpose of this study is to describe alternative techniques available to stabilize these injuries. Materials and Methods Five patients were identified retrospectively with unstable volar lunate facet fracture fragments treated with supplemental fixation techniques. The demographic data, pre- and postoperative radiographic parameters, and early outcomes data were analyzed. The AO classification, preoperative and final postoperative ulnar variance, articular step-off, volar tilt, radial inclination, and teardrop angle were measured. The lunate subsidence and length of the volar cortex available for fixation were measured from the initial injury films. Description of Technique Lunate facet fixation was based on the morphology of the fragment, and stabilization was achieved with headless compression screws in three patients, a tension band wire construct in one, and two cortical screws in another. Results Five patients with a mean age of 58 years (range: 41-82) were included. There were two AO C3.2 and three B3.3 fractures. Preoperative radiographic measurements including radial inclination, tilt, and ulnar variance all improved after surgery and were maintained within normal limits at 3-month follow-up. There was no change in the teardrop angle at final follow-up (70-64 degrees; p = 0.14). None of the patients had loss of fixation or volar carpal subluxation. The mean visual analog scale pain score at 3 months was 1 (range: 0-2). Conclusions The morphology of volar lunate facet fracture fragments is variable, and fixation must be customized to the particular pattern. Small fragments may preclude the use of plates and screws for fixation. These fractures can be managed successfully with tension band wire constructs and headless screws. These low-profile implants may decrease the risk of tendon irritation that might accompany distally placed plates.

Fixation Options for the Volar Lunate Facet Fracture: Thinking Outside the Box

PubMed Central

Harness, Neil G.

2016-01-01

Background Fractures of the distal radius with small volar ulnar marginal fracture fragments are difficult to stabilize with standard volar locking plates. The purpose of this study is to describe alternative techniques available to stabilize these injuries. Materials and Methods Five patients were identified retrospectively with unstable volar lunate facet fracture fragments treated with supplemental fixation techniques. The demographic data, pre- and postoperative radiographic parameters, and early outcomes data were analyzed. The AO classification, preoperative and final postoperative ulnar variance, articular step-off, volar tilt, radial inclination, and teardrop angle were measured. The lunate subsidence and length of the volar cortex available for fixation were measured from the initial injury films. Description of Technique Lunate facet fixation was based on the morphology of the fragment, and stabilization was achieved with headless compression screws in three patients, a tension band wire construct in one, and two cortical screws in another. Results Five patients with a mean age of 58 years (range: 41–82) were included. There were two AO C3.2 and three B3.3 fractures. Preoperative radiographic measurements including radial inclination, tilt, and ulnar variance all improved after surgery and were maintained within normal limits at 3-month follow-up. There was no change in the teardrop angle at final follow-up (70–64 degrees; p = 0.14). None of the patients had loss of fixation or volar carpal subluxation. The mean visual analog scale pain score at 3 months was 1 (range: 0–2). Conclusions The morphology of volar lunate facet fracture fragments is variable, and fixation must be customized to the particular pattern. Small fragments may preclude the use of plates and screws for fixation. These fractures can be managed successfully with tension band wire constructs and headless screws. These low-profile implants may decrease the risk of tendon irritation that might accompany distally placed plates. PMID:26855830

Relativistic stars in vector-tensor theories

NASA Astrophysics Data System (ADS)

Kase, Ryotaro; Minamitsuji, Masato; Tsujikawa, Shinji

2018-04-01

We study relativistic star solutions in second-order generalized Proca theories characterized by a U (1 )-breaking vector field with derivative couplings. In the models with cubic and quartic derivative coupling, the mass and radius of stars become larger than those in general relativity for negative derivative coupling constants. This phenomenon is mostly attributed to the increase of star radius induced by a slower decrease of the matter pressure compared to general relativity. There is a tendency that the relativistic star with a smaller mass is not gravitationally bound for a low central density and hence is dynamically unstable, but that with a larger mass is gravitationally bound. On the other hand, we show that the intrinsic vector-mode couplings give rise to general relativistic solutions with a trivial field profile, so the mass and radius are not modified from those in general relativity.

The Clinical and Economic Impact of Generic Locking Plate Utilization at a Level II Trauma Center.

PubMed

Mcphillamy, Austin; Gurnea, Taylor P; Moody, Alastair E; Kurnik, Christopher G; Lu, Minggen

2016-12-01

In today's climate of cost containment and fiscal responsibility, generic implant alternatives represent an interesting area of untapped resources. As patents have expired on many commonly used trauma implants, generic alternatives have recently become available from a variety of sources. The purpose of this study was to examine the clinical and economic impact of a cost containment program using high quality, generic orthopaedic locking plates. The implants available for study were anatomically precontoured plates for the clavicle, proximal humerus, distal radius, proximal tibia, distal tibia, and distal fibula. Retrospective review. Level II Trauma center. 828 adult patients with operatively managed clavicle, proximal humerus, distal radius, proximal tibia, tibial pilon, and ankle fractures. Operative treatment with conventional or generic implants. The 414 patients treated with generic implants were compared with 414 patients treated with conventional implants. There were no significant differences in age, sex, presence of diabetes, smoking history or fracture type between the generic and conventional groups. No difference in operative time, estimated blood loss or intraoperative complication rate was observed. No increase in postoperative infection rate, hardware failure, hardware loosening, malunion, nonunion or need for hardware removal was noted. Overall, our hospital realized a 56% reduction in implant costs, an average savings of $1197 per case, and a total savings of $458,080 for the study period. Use of generic orthopaedic implants has been successful at our institution, providing equivalent clinical outcomes while significantly reducing implant expenditures. Based on our data, the use of generic implants has the potential to markedly reduce operative costs as long as quality products are used. Therapeutic Level III.

Comparison study of growth plate fusion using MRI versus plain radiographs as used in age determination for exclusion of overaged football players.

PubMed

George, John; Nagendran, Jayaselvi; Azmi, Khairul

2012-03-01

MRI of distal radius fusion is currently being used in the U17 World Cup to exclude overaged players. Developing countries that cannot afford to perform MRI on their players are using plain radiographs based on the same MRI criteria of fusion. The aim of this study is to compare the grade of fusion of the left wrist distal radial growth plate between MRI and plain radiographs. 150 healthy male football players were grouped into five age groups ranging from 15 to 19 years old. Each participant had coronal T1-weighted MRI and plain radiograph of the left wrist. The degree of distal radius fusion was rated randomly by three radiologists using a six-stage grading system proposed by the FIFA Research Centre. MRI assessment of distal radial growth plate fusion has good correlation with plain radiograph fusion (r=0.949). The mean of x-ray grading is higher than the MRI grading in the 15, 16, 17, 18 and 19 years old age groups with p=0.443, 0.001, 0.009, <0.001 and 0.003, respectively, using Wilcoxon signed ranked test. Intraobserver and interobserver correlations were high (r=0.9). T1 MRI correlation with chronological age (r=0.771) was close to plain radiographs (r=0.821) with p value of <0.001. This article is of major importance as it is the first to show that x-rays significantly overrate the grading of fusion in this age group and therefore should not be used to exclude overaged players as is occurring now to the distress of many genuinely eligible players.

History of amenorrhoea compromises some of the exercise-induced benefits in cortical and trabecular bone in the peripheral and axial skeleton: a study in retired elite gymnasts.

PubMed

Ducher, G; Eser, P; Hill, B; Bass, S

2009-10-01

Female gymnasts frequently present with overt signs of hypoestrogenism, such as late menarche or menstrual dysfunction. The objective was to investigate the impact of history of amenorrhoea on the exercise-induced skeletal benefits in bone geometry and volumetric density in retired elite gymnasts. 24 retired artistic gymnasts, aged 17-36 years, who had been training for at least 15 h/week at the peak of their career and had been retired for 3-18 years were recruited. They had not been engaged in more than 2 h/week of regular physical activity since retirement. Former gymnasts who reported history of amenorrhoea ('AME', n=12: either primary or secondary amenorrhoea) were compared with former gymnasts ('NO-AME', n=12) and controls ('C', n=26) who did not report history of amenorrhoea. Bone mineral content (BMC), total bone area (ToA) and total volumetric density (ToD) were measured by pQCT at the radius and tibia (4% and 66%). Trabecular volumetric density (TrD) and bone strength index (BSI) were measured at the 4% sites. Cortical area (CoA), cortical thickness (CoTh), medullary area (MedA), cortical volumetric density (CoD), stress-strain index (SSI) and muscle and fat area were measured at the 66% sites. Spinal BMC, areal BMD and bone mineral apparent density (BMAD) were measured by DXA. Menarcheal age was delayed in AME when compared to NO-AME (16.4+/-0.5 years vs. 13.3+/-0.4 years, p<0.001). No differences were detected between AME and C for height-adjusted spinal BMC, aBMD and BMAD, TrD and BSI at the distal radius and tibia, CoA at the proximal radius, whereas these parameters were greater in NO-AME than C (p<0.05-0.005). AME had lower TrD and BSI at the distal radius, and lower spinal BMAD than NO-AME (p<0.05) but they had greater ToA at the distal radius (p<0.05). Greater spinal BMC, aBMD and BMAD as well as trabecular volumetric density and bone strength in the peripheral skeleton were found in former gymnasts without a history of menstrual dysfunction but not in those who reported either primary or secondary amenorrhoea. History of amenorrhoea may have compromised some of the skeletal benefits associated with high-impact gymnastics training.

Camera-tracking gaming control device for evaluation of active wrist flexion and extension.

PubMed

Shefer Eini, Dalit; Ratzon, Navah Z; Rizzo, Albert A; Yeh, Shih-Ching; Lange, Belinda; Yaffe, Batia; Daich, Alexander; Weiss, Patrice L; Kizony, Rachel

Cross sectional. Measuring wrist range of motion (ROM) is an essential procedure in hand therapy clinics. To test the reliability and validity of a dynamic ROM assessment, the Camera Wrist Tracker (CWT). Wrist flexion and extension ROM of 15 patients with distal radius fractures and 15 matched controls were assessed with the CWT and with a universal goniometer. One-way model intraclass correlation coefficient analysis indicated high test-retest reliability for extension (ICC = 0.92) and moderate reliability for flexion (ICC = 0.49). Standard error for extension was 2.45° and for flexion was 4.07°. Repeated-measures analysis revealed a significant main effect for group; ROM was greater in the control group (F[1, 28] = 47.35; P < .001). The concurrent validity of the CWT was partially supported. The results indicate that the CWT may provide highly reliable scores for dynamic wrist extension ROM, and moderately reliable scores for flexion, in people recovering from a distal radius fracture. N/A. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Distal radius fracture arthroscopic intraarticular displacement measurement after open reduction and internal fixation from a volar approach.

PubMed

Ono, Hiroshi; Furuta, Kazuhiko; Fujitani, Ryotaro; Katayama, Takeshi; Akahane, Manabu

2010-07-01

The purpose of this study was to assess articular surface reduction arthroscopically after volar locked-plate fixation of distal radius fractures (DRFs) via fluoroscopyguided open reduction/internal fixation. We also aimed to develop preoperative radiographic criteria to help assist in determining which DRFs may need arthroscopic evaluation. A total of 31 consecutive patients with DRF were prospectively enrolled. Posteroanterior (PA) and lateral radiographs as well as axial, coronal, and sagittal CT scans were obtained just after attempted reduction of the DRF. The widest articular displacement at the radiocarpal joint surface of the distal radius (preopD) was then measured using a digital radiography imaging system. The DRF was reduced under fluoroscopy, and a volar locked plate was applied. The degree of residual articular displacement was then measured arthroscopically, and the maximum displacement (postopD) was measured with a calibrated probe. Of the 31 patients, 7 had an arthroscopically assessed maximum postopD of > or = 2 mm after internal fixation. The correlation coefficients between each preopD and postopD of all radiographs and CTs were statistically significant. The cutoff values were 0.5 mm for PA radiographs, 2.10 mm for lateral radiographs, 2.15 mm for axial CT scans, 3.15 mm for coronal CT scans, and 1.20 mm for sagittal CT scans. All cutoff values for PA and lateral radiographs and for axial, coronal, and sagittal CT scans were unsuitable as screening criteria for arthroscopic reduction of DRF because of their low sensitivities and specificities. The cutoff value of the new preopD (the sum of the preopDs determined by lateral radiography and coronal CT scan) was 5.80 mm, and its sensitivity and specificity were 100% and 83.3%, respectively. Because a new preopD cutoff value of 5.80 mm is a good indicator for residual articular displacement after internal fixation of >2 mm, it is also a good indicator for the need for arthroscopic evaluation after internal fixation.

Full title: Biomechanical comparison between stainless steel, titanium and carbon-fiber reinforced polyetheretherketone volar locking plates for distal radius fractures.

PubMed

Mugnai, Raffaele; Tarallo, Luigi; Capra, Francesco; Catani, Fabio

2018-05-25

As the popularity of volar locked plate fixation for distal radius fractures has increased, so have the number and variety of implants, including variations in plate design, the size and angle of the screws, the locking screw mechanism, and the material of the plates. carbon-fiber reinforced polyetheretherketone (CFR-PEEK) plate features similar biomechanical properties to metallic plates, representing, therefore, an optimal alternative for the treatment of distal radius fractures. three different materials-composed plates were evaluated: stainless steel volar lateral column (Zimmer); titanium DVR (Hand Innovations); CFR-PEEK DiPHOS-RM (Lima Corporate). Six plates for each type were implanted in sawbones and an extra-articular rectangular osteotomy was created. Three plates for each material were tested for load to failure and bending stiffness in axial compression. Moreover, 3 constructs for each plate were evaluated after dynamically loading for 6000 cycles of fatigue. the mean bending stiffness pre-fatigue was significantly higher for the stainless steel plate. The titanium plate yielded the higher load to failure both pre and post fatigue. After cyclic loading, the bending stiffness increased by a mean of 24% for the stainless steel plate; 33% for the titanium; and 17% for the CFR-PEEK plate. The mean load to failure post-fatigue increased by a mean of 10% for the stainless steel and 14% for CFR-PEEK plates, whereas it decreased (-16%) for the titanium plate. Statistical analysis between groups reported significant values (p <.001) for all comparisons except for Hand Innovations vs. Zimmer bending stiffness post fatigue (p = .197). the significant higher load to failure of the titanium plate, makes it indicated for patients with higher functional requirements or at higher risk of trauma in the post-operative period. The CFR-PEEK plate showed material-specific disadvantages, represented by little tolerance to plastic deformation, and lower load to failure. N/A. Copyright © 2018. Published by Elsevier Masson SAS.

[Manifestation of Dupuytren nodules following fracture of the distal radius].

PubMed

Wichelhaus, Alice; Wendt, M; Mielsch, N; Gradl, G; Mittlmeier, T

2015-02-01

The aim of this study is to evaluate the incidence of post-traumatic development of Dupuytren nodules in distal radius fractures treated operatively. In 2 prospective randomised studies for operative treatment of distal radius fractures, the formation of Dupuytren nodules was registered. One of the exclusion criteria was a pre-existing Dupuytren's disease at the date of trauma. In addition to the notification of the development of Dupuytren nodules, signs of a complex regional pain syndrome were registered as well as the wrist function, level of pain and grip strength. The Castaing and the Gartland and Werley scores were assessed. The clinical outcomes of patients with and without Dupuytren nodules were compared. 239 of 275 (87%) of the patients could be examined 1 year after the operation, consisting of 32 men and 207 women with a median age of 64.2 years. The patients with Dupuytren nodules were re-evaluated after 16-60 months (median 41.8) for progression of the disease. 21 patients (8.7%) developed changes of the palmar aponeurosis. In 20 patients nodules were stated, one patient showed a cord at the fourth ray of the injured hand. 19 out of 21 patients were female (90.5%). At re-evaluation after 41.8 months (16-60) progression could not be noted nor could similar changes be seen on the contralateral side. Patients with Dupuytren nodules were not handicapped in their hand function. 3 patients (14.3%) revealed a positive family history for Dupuytren's disease. Abuse of alcohol or diabetes was not present in any of the patients with Dupuytren nodules, 7 (33%) were smokers. The occurrence of Dupyutren nodules can be triggered by a trauma or operation. It may be speculated that these nodules are an entity of their own as no progression of the contracture could be seen during the follow-up period. © Georg Thieme Verlag KG Stuttgart · New York.

Outcomes of Pin and Plaster Versus Locking Plate in Distal Radius Intraarticular Fractures

PubMed Central

Bahari-Kashani, Mahmoud; Taraz-Jamshidy, Mohammad Hosein; Rahimi, Hassan; Ashraf, Hami; Mirkazemy, Masoud; Fatehi, Amirreza; Asadian, Mariam; Rezazade, Jafar

2013-01-01

Background Distal radius fractures are among the most prevalent fractures predictive of probable occurrence of other osteoporotic fractures. They are treated via a variety of methods, but the best treatment has not been defined yet. Objectives This study was performed to compare the results of open reduction and internal fixation with locking plates versus the pin and plaster method. Materials and Methods In this prospective study, 114 patients aged 40 to 60 years with Fernandez type III fracture referring to Imam-Reza and Mehr hospitals of Mashhad from 2009 to 2011, were selected randomly; after obtaining informed consent, they were treated with pin and plaster fixation (n = 57) or internal fixation with the volar locking plate (n = 57). They were compared at the one year follow up. Demographic features and standard radiographic indices were recorded and MAYO, DASH and SF - 36 tests were performed. Data was analyzed by SPSS software version 13, with descriptive indices, Mann-Whitney and Chi-square tests. Results SF-36 test demonstrated a better general health (P < 0.001), mental health (P = 0.006), physical functioning (P < 0.001), social functioning (P < 0.001) and energy/fatigue (P < 0.001) in LCP group. However, pain (P = 0.647) was not significantly different between the groups. Physical limitation (P < 0.001) and emotional limitation (P < 0.001) were greater in the pin and plaster group. Also, in the LCP group mean MAYO score (P < 0.001) was more than pin and plaster group. Mean DASH score was not different between the groups (P = 0.218). The rate of acceptable results of radiographic indices (P < 0.001), grip strength (P < 0.001) and range of motion in supination-pronation (P < 0.001) in LCP method were better than the pin and plaster method. Conclusions In treatment of intra-articular distal radius fractures in middle-aged patients internal fixation with locking plates may be prefered to pin and plaster as the treatment of choice. PMID:24350132

Comparison of modern locked plating and antiglide plating for fixation of osteoporotic distal fibular fractures.

PubMed

Switaj, Paul J; Wetzel, Robert J; Jain, Neel P; Weatherford, Brian M; Ren, Yupeng; Zhang, Li-Qun; Merk, Bradley R

2016-09-01

Fractures in osteoporotic patients can be difficult to treat because of poor bone quality and inability to gain screw purchase. The purpose of this study is to compare modern lateral periarticular distal fibula locked plating to antiglide plating in the setting of an osteoporotic, unstable distal fibula fracture. AO/OTA 44-B2 distal fibula fractures were created in sixteen paired fresh frozen cadaveric ankles and fixed with a lateral locking plate and an independent lag screw or an antiglide plate with a lag screw through the plate. The specimens underwent stiffness, cyclic loading, and load to failure testing. The energy absorbed until failure, torque to failure, construct stiffness, angle at failure, and energy at failure was recorded. The lateral locking construct had a higher torque to failure (p=0.02) and construct stiffness (p=0.04). The locking construct showed a trend toward increased angle at failure, but did not reach statistical significance (p=0.07). Seven of the eight lateral locking plate specimens failed through the distal locking screws, while the antiglide plating construct failed with pullout of the distal screws and displacement of the fracture in six of the eight specimens. In our study, the newly designed distal fibula periarticular locking plate with increased distal fixation is biomechanically stronger than a non-locking one third tubular plate applied in antiglide fashion for the treatment of AO/OTA 44-B2 osteoporotic distal fibula fractures. V: This is an ex-vivo study performed on cadavers and is not a study performed on live patients. Therefore, this is considered Level V evidence. Copyright © 2015. Published by Elsevier Ltd.

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

PubMed

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

2014-12-01

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

Bilateral Carpus Valgus with Cranial Bowing of the Distal Radius in a Foal

PubMed Central

Caron, J. P.; Fretz, P. B.; Pharr, J. W.; Bailey, J. V.

1986-01-01

Bilateral carpus valgus with concomitant outward rotation and cranial bowing of the distal radii was diagnosed in a crossbred foal. The foal was not lame on admission and showed no radiographic evidence of carpal bone abnormalities. Surgery was limited to the most severely affected leg, and consisted of a combination of growth promotion (periosteal transection and stripping) and temporary physeal retardation (transphyseal bridging) procedures. Correction of the valgus deformity was nearly complete in the operated limb and substantial improvement was observed in the cranial bowing and outward rotation in both limbs, five months postoperatively. ImagesFigure 1.Figure 2. PMID:17422668

Combined radiogrammetry and texture analysis for early diagnosis of osteoporosis using Indian and Swiss data.

PubMed

Areeckal, Anu Shaju; Kamath, Jagannath; Zawadynski, Sophie; Kocher, Michel; S, Sumam David

2018-05-26

Osteoporosis is a bone disorder characterized by bone loss and decreased bone strength. The most widely used technique for detection of osteoporosis is the measurement of bone mineral density (BMD) using dual energy X-ray absorptiometry (DXA). But DXA scans are expensive and not widely available in low-income economies. In this paper, we propose a low cost pre-screening tool for the detection of low bone mass, using cortical radiogrammetry of third metacarpal bone and trabecular texture analysis of distal radius from hand and wrist radiographs. An automatic segmentation algorithm to automatically locate and segment the third metacarpal bone and distal radius region of interest (ROI) is proposed. Cortical measurements such as combined cortical thickness (CCT), cortical area (CA), percent cortical area (PCA) and Barnett Nordin index (BNI) were taken from the shaft of third metacarpal bone. Texture analysis of trabecular network at the distal radius was performed using features obtained from histogram, gray level Co-occurrence matrix (GLCM) and morphological gradient method (MGM). The significant cortical and texture features were selected using independent sample t-test and used to train classifiers to classify healthy subjects and people with low bone mass. The proposed pre-screening tool was validated on two ethnic groups, Indian sample population and Swiss sample population. Data of 134 subjects from Indian sample population and 65 subjects from Swiss sample population were analysed. The proposed automatic segmentation approach shows a detection accuracy of 86% in detecting the third metacarpal bone shaft and 90% in accurately locating the distal radius ROI. Comparison of the automatic radiogrammetry to the ground truth provided by experts show a mean absolute error of 0.04 mm for cortical width of healthy group, 0.12 mm for cortical width of low bone mass group, 0.22 mm for medullary width of healthy group, and 0.26 mm for medullary width of low bone mass group. Independent sample t-test was used to select the most discriminant features, to be used as input for training the classifiers. Pearson correlation analysis of the extracted features with DXA-BMD of lumbar spine (DXA-LS) shows significantly high correlation values. Classifiers were trained with the most significant features in the Indian and Swiss sample data. Weighted KNN classifier shows the best test accuracy of 78% for Indian sample data and 100% for Swiss sample data. Hence, combined automatic radiogrammetry and texture analysis is shown to be an effective low cost pre-screening tool for early diagnosis of osteoporosis. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Size of the Radial Tuberosity is Not Related to the Occurrence of Distal Biceps Tendon Ruptures: A Case-Control Study.

PubMed

Kodde, Izaäk F; van den Bekerom, Michel P J; Mulder, Paul G H; Eygendaal, Denise

2016-01-01

Hypertrophic changes at the radial tuberosity have traditionally been related to distal biceps tendon degeneration and rupture. From supination to pronation of the forearm, the space available for the distal biceps tendon between de lateral ulna and radial bicipital tuberosity (RBT) decreases by almost 50%. A hypertrophic change at the radial tuberosity further reduces this space with impingement of the distal biceps tendon as a result. The purpose of this study was to evaluate whether the size of the RBT plays a role in the pathophysiology of distal biceps tendon ruptures. Twenty-two consecutive patients with a surgically proven distal biceps tendon rupture were matched to controls, in a 1:1 ratio. The size of the RBT was expressed as a ratio of the maximum diameter of the radius at the RBT to the diameter of the diaphysis just distal to the RBT (RD ratio), measured on standard radiographs of the elbow. The RD ratio of patients and matched controls were compared. The mean RD ratio in control group was 1.25 and not significantly different from the mean 1.30 in the group of patients with a distal biceps tendon rupture. Each 0.1 point increase in RD ratio results in an estimated 60% increase of the rupture odds, which was not significant either. Based on the RD ratio on conventional radiographs of the elbow, there was no significant difference in RBT size between patients with a distal biceps tendon rupture and matched controls without biceps tendon pathology.

Locally optimal transfer trajectories between libration point orbits using invariant manifolds

NASA Astrophysics Data System (ADS)

Davis, Kathryn E.

2009-12-01

Techniques from dynamical systems theory and primer vector theory have been applied to the construction of locally optimal transfer trajectories between libration point orbits. When two libration point orbits have different energies, it has been found that the unstable manifold of the first orbit can be connected to the stable manifold of the second orbit with a bridging trajectory. A bounding sphere centered on the secondary, with a radius less than the radius of the sphere of influence of the secondary, was used to study the stable and unstable manifold trajectories. It was numerically demonstrated that within the bounding sphere, the two-body parameters of the unstable and stable manifold trajectories could be analyzed to locate low transfer costs. It was shown that as the two-body parameters of an unstable manifold trajectory more closely matched the two-body parameters of a stable manifold trajectory, the total DeltaV necessary to complete the transfer decreased. Primer vector theory was successfully applied to a transfer to determine the optimal maneuvers required to create the bridging trajectory that connected the unstable manifold of the first orbit to the stable manifold of the second orbit. Transfer trajectories were constructed between halo orbits in the Sun-Earth and Earth-Moon three-body systems. Multiple solutions were found between the same initial and final orbits, where certain solutions retraced interior portions of the trajectory. All of the trajectories created satisfied the conditions for optimality. The costs of transfers constructed using invariant manifolds were compared to the costs of transfers constructed without the use of invariant manifolds, when data was available. In all cases, the total cost of the transfers were significantly lower when invariant manifolds were used in the transfer construction. In many cases, the transfers that employed invariant manifolds were three to four times more efficient, in terms of fuel expenditure, than the transfer that did not. The decrease in transfer cost was accompanied by an increase in transfer time of flight. Transfers constructed in the Earth-Moon system were shown to be particularly viable for lunar navigation and communication constellations, as excellent coverage of the lunar surface can be achieved during the transfer.

[Cinematography, a new diagnostic procedure in evaluation of the injured painful wrist joint].

PubMed

Werber, K D; Wuttge-Hannig, A; Hannig, C

1990-01-01

By the X-ray Cineradiografie we are able to examine and to judge the dynamic of the wrist bones by 50 pictures/sec. in comparison to one another and also depending on their ligaments. We did an investigation of 170 patients with painful wrist. With the method we were able to make up a clear diagnosis and to propose the therapy. I.e.: If consecutive shortening of the radius after distal radius fracture resulting ingruency of the wrist joint is relevant, or a scaphoid pseudarthrosis is fixed elastically, or a scaphoic dissociation is effective. The variations were shown in comparison to normal circumstances.

The equilibrium and stability of the gaseous component of the galaxy, 2

NASA Technical Reports Server (NTRS)

Kellman, S. A.

1971-01-01

A time-independent, linear, plane and axially-symmetric stability analysis was performed on a self-gravitating, plane-parallel, isothermal layer of nonmagnetic, nonrotating gas. The gas layer was immersed in a plane-stratified field isothermal layer of stars which supply a self-consistent gravitational field. Only the gaseous component was perturbed. Expressions were derived for the perturbed gas potential and perturbed gas density that satisfied both the Poisson and hydrostatic equilibrium equations. The equation governing the size of the perturbations in the mid-plane was found to be analogous to the one-dimensional time-independent Schrodinger equation for a particle bound by a potential well, and with similar boundary conditions. The radius of the neutral state was computed numerically and compared with the Jeans' and Ledoux radius. The inclusion of a rigid stellar component increased the Ledoux radius, though only slightly. Isodensity contours of the neutrual or marginally unstable state were constructed.

Incidence patterns of pediatric and adolescent orthopaedic fractures according to age groups and seasons in South Korea: a population-based study.

PubMed

Park, Moon Seok; Chung, Chin Youb; Choi, In Ho; Kim, Tae Won; Sung, Ki Hyuk; Lee, Seung Yeol; Lee, Sang Hyeong; Kwon, Dae Gyu; Park, Jung Woo; Kim, Tae Gyun; Choi, Young; Cho, Tae-Joon; Yoo, Won Joon; Lee, Kyoung Min

2013-09-01

Fractures which need urgent or emergency treatment are common in children and adolescents. This study investigated the incidence patterns of pediatric and adolescent orthopaedic fractures according to age groups and seasons in South Korea based on population data. Data on the number of pediatric and adolescent patients under the age of 18 years who utilized medical services due to fractures were retrieved from the Health Insurance Review and Assessment service in South Korea. The data included four upper extremity and two lower extremity fractures according to four age groups (0-4 years, 5-9 years, 10-14 years, and 15-18 years). Incidences of the fractures were calculated as the incidence per 10,000 per year, and patterns according to age groups and seasons were demonstrated. The annual incidence of clavicle, distal humerus, both forearm bone, distal radius, femoral shaft and tibial shaft fractures were 27.5, 34.6, 7.7, 80.1, 2.5, and 9.6 per 10,000 per year in children and adolescents, respectively. Clavicle and distal radius fractures showed significant seasonal variation for all age groups but femoral shaft fracture showed no significant seasonal variation for any of the age groups. The four upper extremity fractures tended to show greater variations than the two lower extremity fractures in the nationwide database in South Korea. The study results are believed to be helpful in the planning and assignment of medical resources for fracture management in children and adolescents.

Are milk and alternatives and fruit and vegetable intakes during adolescence associated with cortical and trabecular bone structure, density, and strength in adulthood?

PubMed

Z Movassagh, E; Kontulainen, S; Baxter-Jones, A D G; Whiting, S; Szafron, M; Papadimitropoulos, M; Vatanparast, H

2017-02-01

We investigated the impact of food group intake during adolescence on bone structure and strength during adulthood. In females, we found a beneficial effect of adolescent milk and alternatives and fruit and vegetable intake on adult radius shaft and distal tibia bone structure, respectively. No association was observed in males. The purpose of this study was to investigate whether adolescents with high intake of milk and alternatives (M&A) or fruit and vegetables (F&V) had better adult bone structure and strength compared to those with low intake levels. We analyzed data from 47 males and 69 females enrolled in the Pediatric Bone Mineral Accrual Study (PBMAS 1991-2011), who had one peripheral quantitative computed tomography scan at age 29 ± 2 years. We measured radius and tibia shaft total area (ToA), cortical area (CoA), cortical content (CoC), cortical density, bone strength (SSI p ), and muscle area, as well as distal radius and tibia ToA, total density, trabecular area, trabecular content, trabecular density, and bone strength (BSI c ). Sequential 24-h recalls were used to assess M&A and F&V intake; participants were grouped for their mean intake during adolescence (low = bottom quartile, moderate = middle quartiles, high = top quartile) and were compared using multivariate analysis of covariance while adjusting for adult height, muscle area, physical activity, energy and calcium intake and adolescent energy intake, and physical activity. Females with high M&A intake compared to low M&A intake group (mean 3.8 vs. 1.3 servings/day, respectively) had greater adult ToA (14 %, p < 0.05), CoA (15 %, p < 0.01), and CoC (16 %, p < 0.01) at radius shaft. Females with moderate F&V intake compared to low F&V intake group (mean 3.7 vs. 2.1 servings/day, respectively) had greater adult ToA (8.5 %, p < 0.05) at distal tibia. Higher intake of M&A or F&V during adolescence had a long-term beneficial effect on bone structure in females, an association not observed in males.

On fluttering modes for aircraft wing model in subsonic air flow

PubMed Central

Shubov, Marianna A.

2014-01-01

The paper deals with unstable aeroelastic modes for aircraft wing model in subsonic, incompressible, inviscid air flow. In recent author’s papers asymptotic, spectral and stability analysis of the model has been carried out. The model is governed by a system of two coupled integrodifferential equations and a two-parameter family of boundary conditions modelling action of self-straining actuators. The Laplace transform of the solution is given in terms of the ‘generalized resolvent operator’, which is a meromorphic operator-valued function of the spectral parameter λ, whose poles are called the aeroelastic modes. The residues at these poles are constructed from the corresponding mode shapes. The spectral characteristics of the model are asymptotically close to the ones of a simpler system, which is called the reduced model. For the reduced model, the following result is shown: for each value of subsonic speed, there exists a radius such that all aeroelastic modes located outside the circle of this radius centred at zero are stable. Unstable modes, whose number is always finite, can occur only inside this ‘circle of instability’. Explicit estimate of the ‘instability radius’ in terms of model parameters is given. PMID:25484610

Single left coronary artery with separate origins of proximal and distal right coronary arteries from left anterior descending and circumflex arteries--a previously undescribed coronary circulation.

PubMed

Kaul, Pankaj; Javangula, Kalyana

2007-04-20

A single left coronary artery with right coronary artery arising from either left main stem (LMS) or left anterior descending artery (LAD) or circumflex artery (Cx) is an extremely rare coronary anomaly. This is the first report of separate origins of proximal and distal RCA from LAD and circumflex arteries respectively in a patient with a single left coronary artery. This 57 year old patient presented with unstable angina and severe stenotic disease of LAD and Cx arteries and underwent urgent successful quadruple coronary artery bypass grafting. The anomalies of right coronary artery in terms of their origin, number and distribution are reviewed.

Nucleation of an oil phase in a nonionic microemulsion-containing chlorinated oil upon systematic temperature quench.

PubMed

Deen, G Roshan; Pedersen, Jan Skov

2010-06-17

A clear and stable nonionic model microemulsion consisting of pentaoxyethylene glycol dodecyl ether (C(12)E(5)), water, and 1-chlorotetradecane (CLTD) was prepared. This system was subjected to a systematic temperature quench (perturbation out of equilibrium) in steps of 1.0 degrees C from 20.4 to 15.3 degrees C in the unstable region of its phase diagram. The change in turbidity (for droplet volume fractions of 0.02 and 0.08) and hydrodynamic radius (R(h)) (for a droplet volume fraction of 0.02) of the system on its way to its new equilibrium was measured at each quench temperature. For small systematic temperature quenches just below the emulsification failure boundary (EFB) the turbidity decreases and remains constant indicating quick changes in the microstructures. Further lowering of temperature brings the system to the unstable region where the turbidity and light scattering increase sharply as function of time because of expulsion of excess oil from the microemulsion droplets. The newly formed oil-rich droplets grow in size as a function of time. These observations indicate the existence of a narrow but observable metastable region en route to the new equilibrium where both microemulsion droplets and larger oil-rich droplets coexist. The region in which microemulsion droplets are metastable is very narrow and is concentration-dependent. The presence of a metastable region is as for other similar systems attributed to the presence of a free energy barrier for the formation of the larger oil-rich droplets associated with curvature free energy of the surfactant film. The turbidity-time curves were converted to the radius-time curves using a model assuming monodisperse spherical droplets. The obtained results are in good agreement with the results for the hydrodynamic radius. The observed average radius from both type of measurements decreases in the metastable region. By performing calculation of the influence of eccentricity and size polydispersity on the observed radius, we have shown that the distribution of the microemulsion droplets becomes more homogeneous in the metastable region.

All Madelung deformities are not endocrine

PubMed Central

Kumar, Ajay; Rai, Gopal K.; Akhtar, Javed; Phillip, Rajeev; Gutch, Manish; Arya, T. V. S.

2013-01-01

Madelung deformity is a rare inherited disorder associated with endocrine disorders like Turner's syndrome, pseudohypoparathyroidism, but can be seen with short stature homeobox deficiency conditions such as Leri-Weill dyschondrosteosis (LWD) and Langers mesomelic dysplasia. It has also been reported following trauma to the distal radius epiphysis neoplasia mucopolysaccharidosis (MPS) and achondroplasia. Madelung deformity is an abnormality of distal radial epiphysis where in progressive ulnar and volar tilt of the articular surface occurring in association with distal subluxation of ulna. A 13-year-old girl was referred to us for evaluation of bilateral deformity of wrist and short stature. There was ulnar deviation and dorsal tilt of bilateral hands without history of pain to the joint trauma and family history of similar illness. On X-ray, wrist showed malformed distal radial epiphysis with dorsal and ulnar shift and with increased length of phalanges suggestive of Madelung deformity. X-ray spine was normal. Ultrasound abdomen showed normal uterus and ovary and her follicle stimulating hormone. Luteinizing hormone was normal and so was urine MPS screening. Based on the above points the diagnosis of LWD was made. PMID:24251169

All Madelung deformities are not endocrine.

PubMed

Kumar, Ajay; Rai, Gopal K; Akhtar, Javed; Phillip, Rajeev; Gutch, Manish; Arya, T V S

2013-10-01

Madelung deformity is a rare inherited disorder associated with endocrine disorders like Turner's syndrome, pseudohypoparathyroidism, but can be seen with short stature homeobox deficiency conditions such as Leri-Weill dyschondrosteosis (LWD) and Langers mesomelic dysplasia. It has also been reported following trauma to the distal radius epiphysis neoplasia mucopolysaccharidosis (MPS) and achondroplasia. Madelung deformity is an abnormality of distal radial epiphysis where in progressive ulnar and volar tilt of the articular surface occurring in association with distal subluxation of ulna. A 13-year-old girl was referred to us for evaluation of bilateral deformity of wrist and short stature. There was ulnar deviation and dorsal tilt of bilateral hands without history of pain to the joint trauma and family history of similar illness. On X-ray, wrist showed malformed distal radial epiphysis with dorsal and ulnar shift and with increased length of phalanges suggestive of Madelung deformity. X-ray spine was normal. Ultrasound abdomen showed normal uterus and ovary and her follicle stimulating hormone. Luteinizing hormone was normal and so was urine MPS screening. Based on the above points the diagnosis of LWD was made.

Graft-supplemented, augmented external fixation in the treatment of intra-articular distal radial fractures.

PubMed

Tyllianakis, Minos E; Panagopoulos, Andreas; Giannikas, Dimitrios; Megas, Panagiotis; Lambiris, Elias

2006-02-01

This article compares the functional and radiographic outcomes of intraarticular distal radial fractures treated with augmented external fixation in which autologous cancellous bone grafting or Norian SRS (Norian Corp, Cupertino, Calif) was used for filling the metaphyseal void. Thirty non-randomized patients, 15 in each group, with AO type C distal radius fractures (20 men and 10 women; average age: 48 years) were operatively treated between 1998-2000 and retrospectively evaluated. Radial inclination, radial length, volar tilt, and Modified Mayo Wrist Score were assessed at the most recent follow-up evaluation (average: 33.3 months). Overall, 12 (80%) patients in the Norian group had an excellent or good result, 2 had fair, and 1 had poor. In the autologous iliac bone graft group, the results were excellent or good in 11 (73.3%) patients, fair in 1, and poor in 2. No statistical difference between the two types of grafting was noted. Norian SRS is equally effective to cancellous bone as supplementary graft in comminuted distal radial fractures treated by external and Kirschner-wire fixation.

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

PubMed

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

2015-04-01

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

Recurrent neuroma formation after lateral arm free flap coverage with neurorraphy to the posteroantebrachial nerve.

PubMed

Peterson, Steven L; Gordon, Michael J

2004-09-01

We report a patient with previous wrist trauma and development of a symptomatic neuroma of the palmar cutaneous branch of the median nerve. The patient had previously been successfully treated with lateral arm free flap coverage with neurorrhaphy to a segment of the posteroantebrachial cutaneous nerve carried with the flap. Two years following this procedure the patient experienced re-onset of symptoms prompting surgical exploration of the area. At the time of operation a recurrent neuroma was found at the free distal terminus of the transferred posteroantebrachial cutaneous nerve. The neuroma was repositioned into the distal radius via a burr hole with relief of symptoms.

Measurement of radial bone mineral density in patients after heart transplantation.

PubMed

Garlicki, A M; Orchowski, F; Myrdko, T; Wójcik, S; Czerwiński, E; Kukiełka, R; Kapelak, B; Dziatkowiak, A

1996-01-01

Limited physical activity, steroidotherapy and immunosuppression are known risk factors for the development of osteoporosis. The purpose of our current work was to investigate whether patients after heart transplantation (Htx) have an increased incidence of osteoporosis. We compared bone mineral density (BMD) in 32 post-transplant patients with a reference group of 1548 healthy age-matched males. Measurement of BMD was carried out with a Dtx 100 Osteometer on the distal and ultradistal segment of the non-dominant radius. Our results revealed a decreased BMD in HTx patients ranging from 6.9 to 10% in the ultradistal (p = 0.0446) and from 0.4 to 3.5% in the distal segment (p = 0.0593).

Impact of double-tiered subchondral support procedure with a polyaxial locking plate on the stability of distal radius fractures using fresh cadaveric forearms: Biomechanical and radiographic analyses.

PubMed

Tsutsui, Sadaaki; Kawasaki, Keikichi; Yamakoshi, Ken-Ichi; Uchiyama, Eiichi; Aoki, Mitsuhiro; Inagaki, Katsunori

2016-09-01

The present study compared the changes in biomechanical and radiographic properties under cyclic axial loadings between the 'double-tiered subchondral support' (DSS) group (wherein two rows of screws were used) and the 'non-DSS' (NDSS) group (wherein only one row of distal screws was used) using cadaveric forearm models of radius fractures fixed with a polyaxial locking plate. Fifteen fresh cadaveric forearms were surgically operated to generate an Arbeitsgemeinschaft für Osteosynthesefragen (AO) type 23-C2 fracture model with the fixation of polyaxial volar locking plates. The model specimens were randomized into two groups: DSS (n = 7) and NDSS (n = 8). Both the groups received 4 locking screws in the most distal row, as is usually applied, whereas the DSS group received 2 additional screws in the second row inserted at an inclination of about 15° to support the dorsal aspect of the dorsal subchondral bone. Cyclic axial compression test was performed (3000 cycles; 0-250 N; 60 mm/min) to measure absolute rigidity and displacement, after 1, 1000, 2000 and 3000 cycles, and values were normalized relative to cycle 1. These absolute and normalized values were compared between those two groups. Radiographic images were taken before and after the cyclic loading to measure changes in volar tilt (ΔVT) and radial inclination (ΔRI). The DSS group maintained significantly higher rigidity and lower displacement values than the NDSS group during the entire loading period. Radiographic analysis indicated that the ΔVT values of the DSS group were lower than those of the NDSS group. In contrast, the fixation design did not influence the impact of loading on the ΔRI values. Biomechanical and radiographic analyses demonstrated that two rows of distal locking screws in the DSS procedure conferred higher stability than one row of distal locking screws. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

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

PubMed

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

2018-05-10

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

High rate of complications following volar plating of distal radius fractures.

PubMed

Knudsen, Roland; Bahadirov, Zafar; Damborg, Frank

2014-10-01

Fracture of the distal radius (DRF) is one of the most common fractures treated by orthopaedic surgeons. The most common operative treatments of these fractures are open reduction and internal fixation. The incidents and types of complications associated with the use of these operations have not been studied in detail. We performed a retrospective study documenting types of complications and their occurrence in a group of patients who received open reduction and internal fixation. Our definition of a complication was a case in which the patient had one or more complications which required an operation, or suffered from complex regional pain syndrome, or skin healing problems lasting more than four weeks from the operation. A total of 165 patients were included. In all, 39 complications in 30 wrists were registered: i.e. 18% had a minimum of one complication. Our finding that 18% suffer from a serious complication when treated using a volar locking plate must be taken into consideration when surgeons choose between conservative or operative treatment for DRF treatment. A few other studies have looked at the incidents of complications and have reported similar results. not relevant. not relevant.

[Morphometric anatomic study and clinical significance of lunate fossa].

PubMed

Aldemir, Cengiz; Önder, Merve; Doğan, Ali; Duygun, Fatih; Oğuz, Nurettin

2015-01-01

This study aims to investigate the depth, transverse and sagittal diameters of lunate fossa which is a significant structure of the wrist in terms of reducing the risk for volar plate screws, which are administered in distal radius fractures, from penetrating into the joint. Depth, transverse and sagittal diameters of lunate fossa in 50 right and 50 left adult dried radius bones without distal tip damage were measured by using MicroscribeG2X from the MicroScribe G series. Mean lunate fossa depth: left 2.419886±0.51 mm/right 2.543052±0.78 mm, mean lunate fossa sagittal diameter: left 19.656±1.57 mm/right 18.796±1.53 mm, mean lunate fossa transverse diameter: left 11.382±0.65 mm/right 11.106±0.91 mm. There was no statistically significant difference between right and left depth values of lunate fossa (p=0.320), whereas there was statistically significant difference between right and left transverse and sagittal diameters (p=0.006, p=0.048). Measurements involving depth of lunate fossa may guide the development of new anatomic plates and decrease complications like the penetration of screw into joint whilst volar plate administrations.

Effect of shock interactions on the attitude stability of a toroidal ballute for reentry vehicles

NASA Astrophysics Data System (ADS)

Otsu, Hirotaka; Abe, Takashi

2016-11-01

The effect of shock interactions on the attitude stability of a reentry vehicle system with a toroidal ballute was investigated. The hypersonic wind tunnel experimental results showed that when the shock interaction occurred near or outside the ballute, an unstable oscillation of the ballute was observed. This was caused by the local high-pressure region on the ballute surface created by the shock interaction between the shock from the reentry capsule and the shock from the ballute. To avoid this unstable oscillation, the radius of the ballute should be designed to be large enough so that the shock from the capsule will be located inside the ballute, which can avoid the local high-pressure region on the ballute surface.

Improving fast-ion confinement in high-performance discharges by suppressing Alfvén eigenmodes

DOE PAGES

Kramer, Geritt J.; Podestà, Mario; Holcomb, Christopher; ...

2017-03-28

Here, we show that the degradation of fast-ion confinement in steady-state DIII-D discharges is quantitatively consistent with predictions based on the effects of multiple unstable Alfven eigenmodes on beam-ion transport. Simulation and experiment show that increasing the radius where the magnetic safety factor has its minimum is effective in minimizing beam-ion transport. This is favorable for achieving high performance steady-state operation in DIII-D and future reactors. A comparison between the experiments and a critical gradient model, in which only equilibrium profiles were used to predict the most unstable modes, show that in a number of cases this model reproduces themore » measured neutron rate well.« less

Dynamical instabilities in axisymmetric stellar systems. I - Oblate E6 models

NASA Technical Reports Server (NTRS)

Levison, Harold F.; Duncan, Martin J.; Smith, Bruce F.

1990-01-01

The stability of a set of models based on isothermal oblate E6 elliptical galaxies is studied using N-body techniques. The only stable models are those that are near the isotropic model and have nearly equal number of stars in retrograde and prograde orbits. Fast rotators are unstable to modes that appear to be analogous to the classical streaming instability seen in many disk systems. Systems with a large velocity dispersion in the direction of the cylindrical radius are unstable to modes that appear to be similar to the radial orbit instability observed in some spherical systems. However, evidence is presented that these two instabilities may be related, and an instability criterion that applies to both is constructed.

An explanation of unstable wetting fronts in soils

NASA Astrophysics Data System (ADS)

Steenhuis, Tammo; Parlange, Jean-Yves; Kung, Samuel; Stoof, Cathelijne; Baver, Christine

2016-04-01

Despite the findings of Raats on unstable wetting front almost a half a century ago, simulating wetting fronts in soils is still an area of active research. One of the critical questions currently is whether Darcy law is valid at the wetting front. In this talk, we pose that in many cases for dry soils, Darcy's law does not apply because the pressure field across the front is not continuous. Consequently, the wetting front pressure is not dependent on the pressure ahead of the front but is determined by the radius of water meniscuses and the dynamic contact angle of the water. If we further assume since the front is discontinuous, that water flows at one pore at the time, then by using the modified Hoffman relationship - relating the dynamic contact angle to the pore water velocity - we find the elevated pressures at the wetting front typical for unstable flows that are similar to those observed experimentally in small diameter columns. The theory helps also explain the funnel flow phenomena observed in layered soils.

Effect of Denosumab on Peripheral Compartmental Bone Density, Microarchitecture and Estimated Bone Strength in De Novo Kidney Transplant Recipients.

PubMed

Bonani, Marco; Meyer, Ursina; Frey, Diana; Graf, Nicole; Bischoff-Ferrari, Heike A; Wüthrich, Rudolf P

2016-01-01

In a randomized controlled clinical trial in kidney transplant recipients (NCT01377467) we have recently shown that RANKL inhibition with denosumab significantly improved areal bone mineral density (aBMD) when given during the first year after transplantation. The effect of denosumab on skeletal microstructure and bone strength in kidney transplant recipients is not known. The purpose of the present bone microarchitecture ancillary study was to investigate high-resolution peripheral quantitative computed tomography (HRpQCT) data from the distal tibia and distal radius in 24 study patients that had been randomized to receive either two injections of denosumab 60 mg at baseline and after 6 months (n=10) or no treatment (n=14). Consistent with the full trial findings, denosumab reduced biomarkers of bone turnover, and significantly increased aBMD at the lumbar spine (median difference of 4.7%; 95% confidence interval [CI] 2.6 - 7.8; p<0.001). Bone quality as assessed by total and cortical volumetric bone mineral density (Tot. vBMD, Ct.vBMD) and cortical thickness (Ct.Th) increased significantly at the tibia, while changes at the radius were less pronounced. The trabecular volumetric BMD (Tb.vBMD), thickness (Tb. Th), separation (Tb.Sp) and number (Tb.N) and the cortical porosity (Ct.Po) at the tibia and the radius did not significantly change in both treatment groups. Micro-finite element analysis (µFEA) showed that bone stiffness increased significantly at the tibia (median difference 5.6%; 95% CI 1.8% - 9.2%; p=0.002) but not at the radius (median difference 2.9%, 95% CI -3.7% - 9.1%; p=0.369). Likewise, failure load increased significantly at the tibia (median difference 5.1%; 95% CI 2.1% - 8.1%; p=0.002) but not at the radius (median difference 2.4%, 95% CI -3.2% - 8.5%; p=0.336). These findings demonstrate that denosumab improves bone density and bone quality in first-year kidney transplant recipients at risk to develop osteoporosis. © 2016 The Author(s) Published by S. Karger AG, Basel.

Conformational Changes in the Carpus During Finger Traps Distraction

PubMed Central

Leventhal, Evan L.; Moore, Douglas C.; Akelman, Edward; Wolfe, Scott W.; Crisco, Joseph J.

2010-01-01

Introduction Wrist distraction is a common treatment maneuver used clinically for the reduction of distal radial fractures and mid-carpal dislocations. Wrist distraction is also required during wrist arthroscopy to access the radiocarpal joint and has been used as a test for scapholunate ligament injury. However, the effect of a distraction load on the normal wrist has not been well studied. The purpose of this study was to measure the 3-D conformational changes of the carpal bones in the normal wrist as a result of a static distractive load. Methods The dominant wrists of 14 healthy volunteers were scanned using computed tomography at rest and during application of 98N of distraction. Load was applied using finger traps and volunteers were encouraged to relax their forearm muscles and to allow distraction of the wrist. The motions of the bones in the wrist were tracked between the unloaded and loaded trial using markerless bone registration. The average displacement vector of each bone was calculated relative to the radius as well as the interbone distances for 20 bone-bone interactions. Joint separation was estimated at the radiocarpal, midcarpal and carpal-metacarpal joints in the direction of loading using the radius, lunate, capitate and 3rd metacarpal. Results With loading, the distance between the radius and 3rd metacarpal increased an average of 3.3±3.1mm in the direction of loading. This separation was primarily located in the axial direction at the radiocarpal (1.0±1.0mm) and midcarpal (2.0±1.7mm) joints. There were minimal changes in the transverse direction within the distal row, although the proximal row narrowed by 0.98±0.7mm. Distraction between the radius and scaphoid (2.5±2.2mm) was 2.4 times greater than between the radius and lunate (1.0±1.0mm). Conclusions Carpal distraction has a significant effect on the conformation of the carpus, especially at the radiocarpal and midcarpal joints. In the normal wrist, external traction causes twice as much distraction at the lunocapitate joint than at the radiolunate joint. PMID:20141894

Conformational changes in the carpus during finger trap distraction.

PubMed

Leventhal, Evan L; Moore, Douglas C; Akelman, Edward; Wolfe, Scott W; Crisco, Joseph J

2010-02-01

Wrist distraction is a common treatment maneuver used clinically for the reduction of distal radial fractures and midcarpal dislocations. Wrist distraction is also required during wrist arthroscopy to access the radiocarpal joint and has been used as a test for scapholunate ligament injury. However, the effect of a distraction load on the normal wrist has not been well studied. The purpose of this study was to measure the three-dimensional conformational changes of the carpal bones in the normal wrist as a result of a static distractive load. Using computed tomography, the dominant wrists of 14 healthy volunteers were scanned at rest and during application of 98 N of distraction. Load was applied using finger traps, and volunteers were encouraged to relax their forearm muscles and to allow distraction of the wrist. The motions of the bones in the wrist were tracked between the unloaded and loaded trial using markerless bone registration. The average displacement vector of each bone relative to the radius was calculated, as were the interbone distances for 20 bone-bone interactions. Joint separation was estimated at the radiocarpal, midcarpal, and carpometacarpal joints in the direction of loading using the radius, lunate, capitate, and third metacarpal. With loading, the distance between the radius and third metacarpal increased an average of 3.3 mm +/- 3.1 in the direction of loading. This separation was primarily in the axial direction at the radiocarpal (1.0 mm +/- 1.0) and midcarpal (2.0 mm +/- 1.7) joints. There were minimal changes in the transverse direction within the distal row, although the proximal row narrowed by 0.98 mm +/- 0.7. Distraction between the radius and scaphoid (2.5 mm +/- 2.2) was 2.4 times greater than that between the radius and lunate (1.0 mm +/- 1.0). Carpal distraction has a significant (p < .01) effect on the conformation of the carpus, especially at the radiocarpal and midcarpal joints. In the normal wrist, external traction causes twice as much distraction at the lunocapitate joint than at the radiolunate joint. Copyright 2010. Published by Elsevier Inc.

Sustained skeletal benefit from childhood mechanical loading

PubMed Central

Scerpella, T. A.; Dowthwaite, J. N.; Rosenbaum, P. F.

2011-01-01

Summary Preliminary prospective, longitudinal results suggest that pre-menarcheal exposure to artistic gymnastics is associated with greater radius BMC, aBMD, and projected area throughout growth and into early adulthood, more than 4 years after activity cessation. Any loss of benefit associated with de-training appears to be temporary. Introduction Mechanical loading may enhance bone accrual during growth, but prospective evidence of benefit retention is limited. This prospective, longitudinal cohort study tests whether gymnastics is linked to distal radius advantages during growth and four or more years post-training cessation. Methods Semi-annually, female ex/gymnasts and non-gymnasts underwent height and weight measurements; questionnaires assessed calcium intake, physical activity, and maturation. Annual dual energy X-ray absorptiometry scans (Hologic QDR 4500W) measured total body fat-free mass, skull areal density (aBMD), and bone mineral content (BMC); forearm scans measured ultradistal and 1/3 radius area, BMC, and aBMD. Analysis inclusion criteria were: (1) achievement of gynecological age >4 years and (2) for gymnasts, >2 years of pre-menarcheal training (>6 h/week), ceasing between 0.5 year pre-menarche and 1 year post-menarche. Hierarchical linear modeling (HLM v6.0) evaluated outcomes for ex/gymnasts versus non-gymnasts; a slope/intercept discontinuity evaluated de-training effects. Results Data from 14 non-gymnasts and six ex/gymnasts represented outcomes from 4 years pre-menarche to 9 years post-menarche. All adjusted distal radius parameters were higher in ex/gymnasts than non-gymnasts (p<0.02). Ultradistal BMC, ultradistal aBMD, and 1/3 aBMD temporarily decreased with gymnastic cessation (p<0.04); ultradistal area, 1/3 area, and 1/3 BMC did not change significantly. Skull outcomes did not differ between groups or change with activity cessation. Conclusion Gymnastic exposure during childhood and early puberty is associated with greater radius bone mass, size, and aBMD. Despite brief de-training losses in density and mass, significant skeletal benefits are manifested throughout growth and at least 4 years beyond activity cessation into early adulthood. PMID:20838772

Increased cortical area and thickness in the distal radius in subjects with SHOX-gene mutation.

PubMed

Frederiksen, A L; Hansen, S; Brixen, K; Frost, M

2014-12-01

Short-stature homeobox (SHOX) gene haploinsufficiency may cause skeletal dysplasia including Léri-Weill Dyschondrosteosis (LWD), a clinical entity characterised by the triad of low height, mesomelic disproportion and Madelung's deformity of the wrist. Bone microarchitecture and estimated strength in adult SHOX mutation carriers have not been examined. Twenty-two subjects with a SHOX mutation including 7 males and 15 females with a median age of 38.8 [21.1-52.2] years were recruited from five unrelated families. The control group consisted of 22 healthy subjects matched on age and sex. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. Bone geometry, volumetric density, microarchitecture and finite element estimated (FEA) bone strength were measured using high-resolution peripheral quantitative computed tomography (HR-pQCT). A full region of interest (ROI) image analysis and height-matched ROI analyses adjusting for differences in body height between the two groups were performed. Areal BMD and T-scores showed no significant differences between cases and controls. Total radius area was smaller in cases than controls (207 [176-263] vs. 273 [226-298] mm, p<0.01). Radius cortical bone area (74 ± 20 vs. 58 ± 17 mm(2), p=0.01) and thickness (1.16 ± 0.30 vs. 0.84 ± 0.26 mm, p<0.01) as well as total density (428 ± 99 vs. 328 ± 72 mg/cm(3), p<0.01) were higher in SHOX mutation carriers compared to controls. Radius trabecular bone area (119 [103-192] vs. 202 [168-247] mm(2), p<0.01) and trabecular number (1.61 [1.46-2.07] vs. 1.89 [1.73-2.08] mm(-1), p=0.01) were smaller in SHOX mutation carriers. Tibia trabecular thickness was lower in cases (0.067 ± 0.012 vs. 0.076 ± 0.012 mm, p=0.01). These results remained significant after adjustment for differences in body height and when restricting analyses to females. There were no differences in BMD, radius and tibia cortical porosity or FEA failure load between groups. A segment of cortical bone defect was identified in the distal radius adjacent to ulna in five unrelated SHOX mutation carriers. Subjects with a SHOX mutation presented with a different bone geometry in radius and tibia while there were no differences in BMD or failure load compared to controls, suggesting that mutations in SHOX gene may have an impact on bone microarchitecture albeit not bone strength. Copyright © 2014 Elsevier Inc. All rights reserved.

Cross-education for improving strength and mobility after distal radius fractures: a randomized controlled trial.

PubMed

Magnus, Charlene R A; Arnold, Cathy M; Johnston, Geoffrey; Dal-Bello Haas, Vanina; Basran, Jenny; Krentz, Joel R; Farthing, Jonathan P

2013-07-01

To evaluate the effects of cross-education (contralateral effect of unilateral strength training) during recovery from unilateral distal radius fractures on muscle strength, range of motion (ROM), and function. Randomized controlled trial (26-wk follow-up). Hospital, orthopedic fracture clinic. Women older than 50 years with a unilateral distal radius fracture. Fifty-one participants were randomized and 39 participants were included in the final data analysis. Participants were randomized to standard rehabilitation (Control) or standard rehabilitation plus strength training (Train). Standard rehabilitation included forearm casting for 40.4±6.2 days and hand exercises for the fractured extremity. Nonfractured hand strength training for the training group began immediately postfracture and was conducted at home 3 times/week for 26 weeks. The primary outcome measure was peak force (handgrip dynamometer). Secondary outcomes were ROM (flexion/extension; supination/pronation) via goniometer and the Patient Rated Wrist Evaluation questionnaire score for the fractured arm. For the fractured hand, the training group (17.3±7.4kg) was significantly stronger than the control group (11.8±5.8kg) at 12 weeks postfracture (P<.017). There were no significant strength differences between the training and control groups at 9 (12.5±8.2kg; 11.3±6.9kg) or 26 weeks (23.0±7.6kg; 19.6±5.5kg) postfracture, respectively. Fractured hand ROM showed that the training group had significantly improved wrist flexion/extension (100.5°±19.2°) than the control group (80.2°±18.7°) at 12 weeks postfracture (P<.017). There were no significant differences between the training and control groups for flexion/extension ROM at 9 (78.0°±20.7°; 81.7°±25.7°) or 26 weeks (104.4°±15.5°; 106.0°±26.5°) or supination/pronation ROM at 9 (153.9°±23.9°; 151.8°±33.0°), 12 (170.9°±9.3°; 156.7°±20.8°) or 26 weeks (169.4°±11.9°; 162.8°±18.1°), respectively. There were no significant differences in Patient Rated Wrist Evaluation questionnaire scores between the training and control groups at 9 (54.2±39.0; 65.2±28.9), 12 (36.4±37.2; 46.2±35.3), or 26 weeks (23.6±25.6; 19.4±16.5), respectively. Strength training for the nonfractured limb after a distal radius fracture was associated with improved strength and ROM in the fractured limb at 12 weeks postfracture. These results have important implications for rehabilitation strategies after unilateral injuries. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

[Meta-analysis of risk factors of recurrence in patients with giant cell tumor on extremities].

PubMed

Li, Rongrui; Hu, Yongcheng

2014-12-23

To explore the risk factors of giant cell tumor on extremities for patients with postoperative recurrence. The literature reports published before June 2014 were searched in the electronic databases of CBM, CNKI, PUBNED, MEDLINE and EMBASE. Meta-analysis was performed by software Review Manager (Version 5.3). The odds ratios (OR) of gender, age, tumor site, Campanacci Classification, pathological fracture, selection of treatment and soft tissue invasion were analyzed with heterogeneity test. Publication bias were tested by funnel plot and fail-safe number.Sensitivity analysis was performed to assess the stability. A total of 15 case-control studies were identified. Age, location and type of surgery were associated with tumor recurrence. The combined OR (95%CI) was 1.83 (1.04-3.24) P = 0.04 for aged <20 years, 0.52(0.31-0.86) P = 0.01 for aged >40 years, 1.60 (1.06-2.42) P = 0.02 for distal radius, 0.35 (0.14-0.90) P = 0.03 for proximal humerus, 3.64 (1.88-7.04) P = 0.0001 for curettage,0.56 (0.35-0.91) P = 0.02 for curettage with PMMA, 1.79 (1.11-2.88) P = 0.02 for curettage with bone graft and adjuvant and 0.29 (0.12-0.66) P = 0.003 for resection respectively. There were not significant relationship between tumor recurrence and gender, tumor location (distal femur, proximal femur, distal tibia, proximal tibia), Jaffe staging, Campanacci classification,Enneking classification, pathological fracture, soft tissue invasion, extensive curettage, curettage with bone graft, curettage with polymethylmethacrylate and adjuvant (P > 0.05). Youth (aged <20 years), distal radius, curettage and curettage with bone graft and adjuvant are the risk factors for recurrence of giant cell tumor.However, advanced age (aged >40 years), proximal tibia, curettage with PMMA and resection appear to have lower risks for tumor recurrence.

In vivo endoscopic optical coherence tomography by use of a rotational microelectromechanical system probe

NASA Astrophysics Data System (ADS)

Tran, Peter H.; Mukai, David S.; Brenner, Matthew; Chen, Zhongping

2004-06-01

A novel endoscopic optical coherence tomography probe was designed and constructed with a 1.9-mm microelectromechanical system (MEMS) motor. The new MEMS endoscopic probe design eliminates the need to couple the rotational energy from the proximal to the distal end of the probe. Furthermore, the endoscopic probe's sheath and fiber have the advantages of having a much smaller diameter and being more flexible than traditional endoscopes since no reinforcement is needed to couple the rotational torque. At the distal end, a prism mounted on a micromotor deflects the light rays to create a transverse circular-scanning pathway. Because our MEMS scanner does not require the coupling of a rotational single-mode fiber, a high scanning speed is possible while eliminating unstable optical signals caused by nonuniform coupling.

The effect of obesity and gender on body segment parameters in older adults

PubMed Central

Chambers, April J.; Sukits, Alison L.; McCrory, Jean L.; Cham, Rakié

2010-01-01

Background Anthropometry is a necessary aspect of aging-related research, especially in biomechanics and injury prevention. Little information is available on inertial parameters in the geriatric population that account for gender and obesity effects. The goal of this study was to report body segment parameters in adults aged 65 years and older, and to investigate the impact of aging, gender and obesity. Methods Eighty-three healthy old (65–75 yrs) and elderly (>75 yrs) adults were recruited to represent a range of body types. Participants underwent a whole body dual energy x-ray absorptiometry scan. Analysis was limited to segment mass, length, longitudinal center of mass position, and frontal plane radius of gyration. A mixed-linear regression model was performed using gender, obesity, age group and two-way and three-way interactions (α=0.05). Findings Mass distribution varied with obesity and gender. Males had greater trunk and upper extremity mass while females had a higher lower extremity mass. In general, obese elderly adults had significantly greater trunk segment mass with less thigh and shank segment mass than all others. Gender and obesity effects were found in center of mass and radius of gyration. Non-obese individuals possessed a more distal thigh and shank center of mass than obese. Interestingly, females had more distal trunk center of mass than males. Interpretation Age, obesity and gender have a significant impact on segment mass, center of mass and radius of gyration in old and elderly adults. This study underlines the need to consider age, obesity and gender when utilizing anthropometric data sets. PMID:20005028

Age-related decrements in bone mineral density in women over 65

NASA Technical Reports Server (NTRS)

Steiger, P.; Cummings, S. R.; Black, D. M.; Spencer, N. E.; Genant, H. K.

1992-01-01

Age-related changes in bone density contribute to the risk of fractures. To describe the relationship between age and bone mass in elderly women, we studied a large cohort of women over age 65 years who were recruited from population-based lists in four cities in the United States. Bone density in g/cm2 was measured by single-photon absorptiometry (SPA) and dual x-ray absorptiometry (DXA) at the distal and proximal radius, the calcaneus, the lumbar spine, and the proximal femur. Centralized data collection was used to control data quality and consistency. We found a strong inverse relationship between bone density and age for most sites. Decrements in bone density between women aged 65-69 years and women 85 years and older exceeded 16% in all regions except the spine, where the difference between the two age groups was 6%. Ward's triangle and the calcaneus exhibited the largest decrements, with 26 and 21%, respectively. The estimates of annual changes in bone mineral density by linear regression at sites other than the spine ranged from -0.82% at the femoral neck and trochanter to -1.30% at Ward's triangle. Correlations between the different regions ranged from r = 0.51 between the proximal radius and Ward's triangle to r = 0.66 between the distal radius and calcaneus. We conclude that the inverse relationship between age and bone mass measured by absorptiometry techniques in white women continues into the ninth decade of life. The relationship is strongest for bone density of Ward's triangle and the calcaneus and weakest for the spine.

Effect of Positioning of the ROI on BMD of the Forearm and Its Subregions.

PubMed

Rosen, Elizabeth O; McNamara, Elizabeth A; Whittaker, LaTarsha G; Malabanan, Alan O; Rosen, Harold N

2018-03-21

Inconsistent positioning of patients and region of interest (ROI) is known to influence the precision of bone mineral density (BMD) measurements in the spine and hip. However, it is unknown whether minor shifts in the positioning of the ROI along the shaft of the radius affect the measurement of forearm BMD and its subregions. The ultradistal (UD-), mid-, one-third, and total radius BMDs of 50 consecutive clinical densitometry patients were acquired. At baseline the distal end of the ROI was placed at the tip of the ulnar styloid as usual, and then the forearm was reanalyzed 10 more times, each time shifting the ROI 1 mm proximally. No corrections for multiple comparisons were necessary since the differences that were significant were significant at p < 0.001. The UD-radius BMD increased as the ROI was shifted proximally; the increase was significant when shifted even 1 mm proximally (p < 0.001). These same findings held true for the mid- and total radius bone density, though the percent increase with moving proximally was significantly greater for the UD radius than for the other subregions. However, there was no significant change in the one-third radius BMD when shifted proximally 1-10 mm. Minor proximal shifts of the forearm ROI substantially affect the BMD of the UD-, mid- and total radius, while having no effect on the one-third radius BMD. Since the one-third radius is the only forearm region usually reported, minor proximal shifts of the ROI should not influence forearm BMD results significantly. Copyright © 2018 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

The relations among upper-extremity loading characteristics and bone mineral density changes in young women.

PubMed

Wang, Man-Ying; Salem, George J

2004-06-01

The relations among the reaction forces engendered during an upper-extremity dynamic impact-loading exercise (DILE) program and bone mineral density adaptations (DeltaBMD) in the radius were investigated in 24 healthy premenopausal women (mean age = 29 +/- 6 years). Subjects performed DILE 36 cycles/day, 3 days/week for 24 weeks. The exercised arm was allocated randomly to either the dominant or the nondominant limb. In addition, subjects were assigned randomly into either damped or nondamped treatment arms to examine the effects of both higher- and lower-magnitude loading prescriptions. Measurements including anthropometrics, self-reported physical activity levels, hand-grip strength, radial BMD (DEXA, Hologic QDR1500, MA) at the ultradistal radius (UD), distal 1/3 radius (DR), and total distal radius (TOTAL), and exercise-related loading characteristics (impact load, loading rate, and impulse) were recorded at baseline and at 6 months. Simple linear regression models were used to fit the regional BMD changes to the reaction force, changes in hand-grip strength (DeltaGRIP), and changes in body weight (DeltaBW). Findings demonstrated that the damping condition utilized during DILE influenced the relations between loading events and BMD changes. Specifically, none of the reaction-force characteristics significantly predicted changes in BMD in participants performing DILE using the damped condition, whereas, in the nondamped condition, impact load accounted for 58% of the variance in BMD change at DR and 66% of the variance in BMD change at TOTAL. Thresholds of 345 and 285 N of impact force to promote BMD increases at DR and TOTAL, respectively, were obtained from the regression models in the nondamped group. Impulse was also an independent predictor of BMD changes at TOTAL, accounting for 56% of the variance. Neither DeltaGRIP nor DeltaBW significantly predicted DeltaBMD at any radial site. These findings, in young adult women, parallel previous reports identifying significant, regionally specific relations among external loading events and BMD changes in both animal and human models.

One-dimensional Turbulence Models of Type I X-ray Bursts

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

Hou, Chen

Type I X-ray bursts are caused by thermonuclear explosions occurring on the surface of an accreting neutron star in a binary star system. Observations and simulations of these phenomena are of great importance for understanding the fundamental properties of neutron stars and dense matter because the equation of state for cold dense matter can be constrained by the mass-radius relationship of neutron stars. During the bursts, turbulence plays a key role in mixing the fuels and driving the unstable nuclear burning process. This dissertation presents one-dimensional models of photospheric radius expansion bursts with a new approach to simulate turbulent advection.more » Compared with the traditional mixing length theory, the one-dimensional turbulence (ODT) model represents turbulent motions by a sequence of maps that are generated according to a stochastic process. The light curves I obtained with the ODT models are in good agreement with those of the KEPLER model in which the mixing length theory and various diffusive processes are applied. The abundance comparison, however, indicates that the differences in turbulent regions and turbulent diffusivities result in more 12C survival during the bursts in the ODT models, which can make a difference in the superbursts phenomena triggered by unstable carbon burning.« less

Fibrosarcoma in the distal radius and carpus of a four-year-old Persian.

PubMed

Cook, J L; Turk, J R; Tomlinson, J L; Corwin, L A; Shaw, D C

1998-01-01

A four-year-old Persian was presented for evaluation of a nonweight-bearing, left forelimb lameness. Radioulnar and pancarpal osteolysis with minimal periosteal reaction were seen on radiographs of the antebrachium. Cytological examinations of fine-needle aspirates and impression smears were suggestive of sarcoma. After forequarter amputation, histopathological examination provided a diagnosis of fibrosarcoma with axillary lymph-node metastasis.

Women with previous fragility fractures can be classified based on bone microarchitecture and finite element analysis measured with HR-pQCT.

PubMed

Nishiyama, K K; Macdonald, H M; Hanley, D A; Boyd, S K

2013-05-01

High-resolution peripheral quantitative computed tomography (HR-pQCT) measurements of distal radius and tibia bone microarchitecture and finite element (FE) estimates of bone strength performed well at classifying postmenopausal women with and without previous fracture. The HR-pQCT measurements outperformed dual energy x-ray absorptiometry (DXA) at classifying forearm fractures and fractures at other skeletal sites. Areal bone mineral density (aBMD) is the primary measurement used to assess osteoporosis and fracture risk; however, it does not take into account bone microarchitecture, which also contributes to bone strength. Thus, our objective was to determine if bone microarchitecture measured with HR-pQCT and FE estimates of bone strength could classify women with and without low-trauma fractures. We used HR-pQCT to assess bone microarchitecture at the distal radius and tibia in 44 postmenopausal women with a history of low-trauma fracture and 88 age-matched controls from the Calgary cohort of the Canadian Multicentre Osteoporosis Study (CaMos) study. We estimated bone strength using FE analysis and simulated distal radius aBMD from the HR-pQCT scans. Femoral neck (FN) and lumbar spine (LS) aBMD were measured with DXA. We used support vector machines (SVM) and a tenfold cross-validation to classify the fracture cases and controls and to determine accuracy. The combination of HR-pQCT measures of microarchitecture and FE estimates of bone strength had the highest area under the receiver operating characteristic (ROC) curve of 0.82 when classifying forearm fractures compared to an area under the curve (AUC) of 0.71 from DXA-derived aBMD of the forearm and 0.63 from FN and spine DXA. For all fracture types, FE estimates of bone strength at the forearm alone resulted in an AUC of 0.69. Models based on HR-pQCT measurements of bone microarchitecture and estimates of bone strength performed better than DXA-derived aBMD at classifying women with and without prior fracture. In future, these models may improve prediction of individuals at risk of low-trauma fracture.

Site-specific, adult bone benefits attributed to loading during youth: A preliminary longitudinal analysis.

PubMed

Scerpella, Tamara A; Bernardoni, Brittney; Wang, Sijian; Rathouz, Paul J; Li, Quefeng; Dowthwaite, Jodi N

2016-04-01

We examined site-specific bone development in relation to childhood and adolescent artistic gymnastics exposure, comparing up to 10years of prospectively acquired longitudinal data in 44 subjects, including 31 non-gymnasts (NON) and 13 gymnasts (GYM) who participated in gymnastics from pre-menarche to ≥1.9years post-menarche. Subjects underwent annual regional and whole-body DXA scans; indices of bone geometry and strength were calculated. Anthropometrics, physical activity, and maturity were assessed annually, coincident with DXA scans. Non-linear mixed effect models centered growth in bone outcomes at menarche and adjusted for menarcheal age, height, and non-bone fat-free mass to evaluate GYM-NON differences. A POST-QUIT variable assessed the withdrawal effect of quitting gymnastics. Curves for bone area, mass (BMC), and strength indices were higher in GYM than NON at both distal radius metaphysis and diaphysis (p<0.0001). At the femoral neck, greater GYM BMC (p<0.01), narrower GYM endosteal diameter (p<0.02), and similar periosteal width (p=0.09) yielded GYM advantages in narrow neck cortical thickness and buckling ratio (both p<0.001; lower BR indicates lower fracture risk). Lumbar spine and sub-head BMC were greater in GYM than NON (p<0.036). Following gymnastics cessation, GYM slopes increased for distal radius diaphysis parameters (p≤0.01) and for narrow neck BR (p=0.02). At the distal radius metaphysis, GYM BMC and compressive strength slopes decreased, as did slopes for lumbar spine BMC, femoral neck BMC, and narrow neck cortical thickness (p<0.02). In conclusion, advantages in bone mass, geometry, and strength at multiple skeletal sites were noted across growth and into young adulthood in girls who participated in gymnastics loading to at least 1.9years post-menarche. Following gymnastics cessation, advantages at cortical bone sites improved or stabilized, while advantages at corticocancellous sites stabilized or diminished. Additional longitudinal observation is necessary to determine whether residual loading benefits enhance lifelong skeletal strength. Copyright © 2016 Elsevier Inc. All rights reserved.

Sex differences and growth-related adaptations in bone microarchitecture, geometry, density and strength from childhood to early adulthood: a mixed longitudinal HR-pQCT study

PubMed Central

Gabel, Leigh; Macdonald, Heather M.; McKay, Heather A.

2016-01-01

Sex differences in bone strength and fracture risk are well-documented. However, we know little about bone strength accrual during growth and adaptations in bone microstructure, density and geometry that accompany gains in bone strength. Thus, our objectives are to 1) describe growth related adaptations in bone microarchitecture, geometry, density and strength at the distal tibia and radius in boys and girls; 2) compare differences in adaptations in bone microarchitecture, geometry, density and strength between boys and girls. We used HR-pQCT at the distal tibia (8% site) and radius (7% site) in 184 boys and 209 girls (9–20y at baseline). We aligned boys and girls on a common maturational landmark (age at peak height velocity; APHV) and fit a mixed effects model to these longitudinal data. Importantly, boys demonstrated 28–63% greater estimated bone strength across 12 years of longitudinal growth. Boys demonstrated 28–80% more porous cortices compared with girls at both sites across all biological ages, except at the radius at 9 years post-APHV. However, cortical density was similar between boys and girls at all ages at both sites, except at 9 years post-APHV at the tibia when girls’ values were 2% greater than boys’. Boys demonstrated 13–48% greater cortical and total bone area across growth. Load-to-strength ratio was 26–27% lower in boys at all ages, indicating lower risk of distal forearm fracture compared with girls. Contrary to previous HR-pQCT studies that did not align boys and girls at the same biological age, we did not observe sex differences in Ct.BMD. Boys’ superior bone size and strength compared with girls may confer them a protective advantage. However, boys’ consistently more porous cortices may contribute to boys’ higher fracture incidence during adolescence. Large prospective studies using HR-pQCT that target boys and girls who have sustained a fracture are needed to verify this. PMID:27556581

It is not just comfort: waterproof casting increases physical functioning in children with minimally angulated distal radius fractures.

PubMed

Silva, Mauricio; Avoian, Tigran; Warnock, Robert Sean; Sadlik, Gal; Ebramzadeh, Edward

2017-09-01

Waterproof casting has been reported to increase patient comfort and satisfaction, and decrease skin irritation. There are no available data on the influence of waterproof casting materials on physical function in pediatric patients. Our aim was to determine whether the use of waterproof casting would result in faster recovery of physical function while maintaining similar clinical outcomes as those obtained with nonwaterproof materials. Twenty-six children with nonangulated or minimally angulated distal radius fractures were assigned randomly to initially receive a short-arm cast made of one of two optional materials: a hybrid mesh material with a waterproof lining or fiberglass with a nonwaterproof skin protector. Two weeks later, the initial cast was removed and replaced with a short-arm cast made of the alternative option. We compared the rate of fracture displacement, physical function, pain, skin changes, itchiness, and patient satisfaction. No evidence of displacement was found in either group. The mean Activities Scale for Kids - Performance (ASK-P) (physical function) score was 10% higher during the period of time when a waterproof cast was used (P=0.04). When a waterproof cast was used during the first 2 weeks of treatment, the mean total ASK-P scores were 23% higher than that when a nonwaterproof one was used during the same period of time (P=0.003). Patients who received a waterproof cast as the initial treatment reported lower functional scores overall and in almost every domain of the ASK-P once they were in a nonwaterproof one; similarly, those who received a nonwaterproof cast as the initial treatment reported higher functional scores overall and in every domain of the ASK-P once they were in a waterproof cast. Compared with a nonwaterproof cast, the use of waterproof casting resulted in comparable levels of pain, itchiness, skin irritability, and overall patient satisfaction. The results of this randomized, cross-over trial suggest that the use of waterproof casting material for the treatment of nondisplaced or minimally displaced distal radius fractures in children can result in a faster recovery of physical function, while providing comparable stability, pain, itchiness, skin irritability, and overall patient satisfaction. II.

Volar locking plate (VLP) versus non-locking plate (NLP) in the treatment of die-punch fractures of the distal radius, an observational study.

PubMed

Zhang, Xiong; Hu, Chunhe; Yu, Kunlun; Bai, Jiangbo; Tian, Dehu; Xu, Yi; Zhang, Bing

2016-10-01

This study aims to evaluate whether volar locking plate was superior over non-locking plate in the treatment of die-punch fractures of the distal radius. A total of 57 patients with closed die-punch fractures of the distal radius were included and analyzed. Of them, 32 were treated by non-locking plate (NLP) and the remaining 25 were treated by volar locking plate (VLP). Preoperative radiographs, computer tomographs and three-dimensional reconstruction, radiographs taken at immediate postoperation and at last follow-up were extracted and evaluated. Patients' electronic medical records were inquired and related demographic and medical data were documented. The documented contents were volar tilt, radial inclination, ulnar variance, grip strength, Disabilities of the Arm, Shoulder, and Hand (DASH) and visual analog scale (VAS) scores and complications. VLP group demonstrated a significantly reduced radial subsidence of 1.5 mm (0.7 versus 2.2 mm), during the interval of bony union (P < 0.001), compared to NLP group. Larger proportion of patients (88% versus 62.5%) in VLP group gained acceptable joint congruity (step-off <2 mm) at the final follow-up (P = 0.037). No significant differences were observed between the groups in the measurements of volar tilt, radial inclination, DASH, VAS and grip strength recovery at the last follow-up. There was a trend of fewer overall complications (5/25 versus 10/32) and major complications that required surgery interventions (1/25 versus 4/32) in VLP than NLP groups, although the difference did not approach to significance (P = 0.339, 0.372). VLP leaded to significantly better results of reduction maintainance and the final joint congruity than NLP, while reducing overall and major complications. However, the results should be treated in the context of limitations and the clinical significance of the difference required further studies to investigate. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Deficits in distal radius bone strength, density and microstructure are associated with forearm fractures in girls: an HR-pQCTstudy

PubMed Central

Määttä, M.; Macdonald, H. M.; Mulpuri, K.

2016-01-01

Summary Forearm fractures are common during growth. We studied bone strength in youth with a recent forearm fracture. In girls, suboptimal bone strength was associated with fractures. In boys, poor balance and physical inactivity may lead to fractures. Prospective studies will confirm these relationships and identify targets for prevention strategies. Introduction The etiology of pediatric forearm fractures is unclear. Thus, we examined distal radius bone strength, microstructure, and density in children and adolescents with a recent low- or moderate-energy forearm fracture and those without forearm fractures. Methods We assessed the non-dominant (controls) and non-fractured (cases) distal radius (7 % site) using high-resolution peripheral quantitative computed tomography (HR-pQCT) (Scanco Medical AG) in 270 participants (girls: cases n=47, controls n=61 and boys: cases n=88, controls n=74) aged 8–16 years. We assessed standard anthropometry, maturity, body composition (dual energy X-ray absorptiometry (DXA), Hologic QDR 4500 W) physical activity, and balance. We fit sex-specific logistic regression models for each bone outcome adjusting for maturity, ethnicity, height, and percent body fat. Results In girls, impaired bone strength (failure load, ultimate stress) and a high load-to-strength ratio were associated with low-energy fractures (odds ratios (OR) 2.8–4.3). Low total bone mineral density (Tt.BMD), bone volume ratio, trabecular thickness, and cortical BMD and thickness were also associated with low-energy fractures (ORs 2.0–7.0). In boys, low Tt.BMD, but not bone strength, was associated with low-energy fractures (OR=1.8). Boys with low-energy fractures had poor balance and higher percent body fat compared with controls (p<0.05). Boys with fractures (both types) were less active than controls (p<0.05). Conclusions Forearm fracture etiology appears to be sex-specific. In girls, deficits in bone strength are associated with fractures. In boys, a combination of poor balance, excess body fat, and low physical activity may lead to fractures. Prospective studies are needed to confirm these relationships and clarify targets for prevention strategies. PMID:25572041

Pulsed Flow Pinch

NASA Astrophysics Data System (ADS)

Hartman, Charles

2005-10-01

Formation of a Pulsed Flow Pinch is discussed, based on 2-D, MHD numerical calculations. The PFP utilizes the observed stable, Btheta magnetic ``bubble'' which propagates from breach to muzzle during the run-down phase of the coaxial Marshall gun. We consider two ways of launching a PFP onto a fiber or cylindrical gas cloud: 1) by propagating the bubble to small radius along an exponentially-decreasing-radius center conductor and, 2) by a radial launch to form reflex PFP's propagating in opposite directions along a fiber. We show that the bubble velocity increases to high values as the radius is decreased making the rise time of Btheta at an axial point very short. A bubble, launched into uniform gas is found to undergo unstable pinching of the front. Results will be presented of calculations of a PFP driven, neutron-producing, snow-plow pinch. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

Sex determination from the radius and ulna in a modern South African sample.

PubMed

Barrier, I L O; L'Abbé, E N

2008-07-18

With a large number of unidentified skeletal remains found in South Africa, the development of population specific osteometric standards is imperative. Forensic anthropologists need to have access to a variety of techniques to establish accurate demographic profiles from complete, fragmentary and/or commingled remains. No research has been done on the forearm of African samples, even though these bones have been shown to exhibit sexual dimorphism. The purpose of this paper is to develop discriminant function formulae to determine sex from the radius and ulna in a South African population. The sample consisted of 200 male and 200 female skeletons from the Pretoria Bone (University of Pretoria) and Raymond A. Dart (Witwatersrand University) collections. Sixteen standard anthropometric measurements were taken from the radius (9) and ulna (7) and subjected to stepwise and direct discriminant function analysis. Distal breadth, minimum mid-shaft diameter and maximum head diameter were the best discriminators of sex for the radius, while minimum mid-shaft diameter and olecranon breadth were selected for the ulna. Classification accuracy for the forearm ranged from 76 to 86%. The radius and ulna can be considered moderate discriminators for determining sex in a South African group. However, it is advised that these formulae are used in conjunction with additional methods to determine sex.

Skeletal mass in rheumatoid arthritis: a comparison with forearm bone mineral content. [Photon transmission scanning of bone tissues

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

Zanzi, I.; Roginsky, M.S.; Ellis, K.J.

1976-01-01

The evaluation of diffuse osteoporosis in patients with rheumatoid arthritis (RA) remains controversial. An important associated problem is the compounded effect of osteopenia secondary to chronic corticosteroid treatment. Photon-absorptiometric techniques have been utilized for measurements of selected sites of the skeleton, such as the distal femur and the distal radius. The development of the technique of in-vivo total body neutron activation analysis (TBNAA) along with whole body counting, has made possible the direct measurement of skeletal mass (total body calcium, TBCa). The TBCa and radial bone mineral content (BMC) were evaluated in 19 Caucassian women with R.A., with and withoutmore » a history of corticosteroid treatment. (auth)« less

Angioscopy by a new percutaneous transluminal coronary angioscope

NASA Astrophysics Data System (ADS)

Sakurada, Masami; Mizuno, Kyoichi; Miyamoto, Akira; Arakawa, Koh; Satomura, Kimio; Shibuya, Toshio; Yanagida, Shigeki; Okamoto, Yasuyuki; Kurita, Akira; Nakamura, Haruo; Arai, Tsunenori; Suda, Akira; Kikuchi, Makoto; Utsumi, Atsushi; Takeuchi, Kiyoshi; Akai, Yoshiro

1990-07-01

We developed a new percutaneous transluminal coronary angioscopic catheter for visualization of coronary artery.This angioscopic catheter has an inflatable balloon at the distal tip and one - directional angulation mechanism.We performed percutaneous transluminal coronary angioscopy during cardiac catheterization cosecutively in 155 patients. With this angioscope , we could get good'-'fair visualization in 81%(131 of 162 lesions)without major complications.We could investigate the endothelial macropathology of ischemic heart disease such as unstable angina and acute myocardial infarction.

External fixation versus open reduction with locked volar plating for geriatric distal radius fractures.

PubMed

Lee, Daniel J; Elfar, John C

2014-09-01

The optimal management of displaced dorsal radius fractures (DRFs) in older patients remains an issue of debate. Bridging external fixation is a well-accepted treatment modality for severely comminuted DRFs, while open reduction and internal fixation with locked volar plating has emerged as a promising alternative in recent years. The current body of randomized trials supports the trend toward locked volar plating, as it allows for quicker improvement in subjective and functional outcomes. There is no clear evidence to suggest that one technique carries significantly less complications than the other. Locked volar plating should be considered in patients for whom an accelerated functional recovery would be advantageous. Otherwise, both external fixation and locked volar plating provide good long-term clinical outcomes.

A Novel Combined Hybrid Approach to Enable Revascularisation of a Trauma-Induced Subclavian Artery Injury.

PubMed

Sabbagh, C N; Chowdhury, M M; Durrani, A; Van Rensburg, L; Koo, B; Coughlin, P A

2016-01-01

This case highlights the complexity of upper limb revascularization after a subclavian artery traumatic injury and strengthens the role of a hybrid/multi-disciplinary approach to such injuries. A 45-year-old male patient presented with an acute right upper limb following a traumatic injury to the right subclavian artery due to a motor vehicle accident (MVA). Associated injuries included an unstable cervical spine injury, a large open right clavicular injury, and a brain injury, which limited the potential revascularisation options available. The arm was revascularised using a hybrid endovascular/open surgical approach, namely embolization of the proximal subclavian artery (just distal to vertebral artery) and a right common femoral artery to distal axillary artery bypass using prosthetic material. Blunt injuries to the subclavian artery are often high impact, complex and associated with multiple injuries to surrounding structures, which limit the role of standard procedures used in the elective setting. This case highlights the role of multidisciplinary team involvement, using a hybrid approach and a novel distal inflow site to restore upper limb perfusion.

Acute flexor tendon injury following midshaft radius and ulna fractures in a paediatric patient.

PubMed

Williams, James; Wharton, Rupert; Peev, Peter; Horwitz, Maxim

2018-06-01

Delayed rupture of the extensor and flexor tendons are recognised complications of distal radius fractures. However, acute flexor tendon rupture in the context of forearm fractures is rare. A twelve-year-old female sustained midshaft fractures of the radius and ulna. Intra-operatively the flexor pollicis longus (FPL) was found to be stripped from its musculotendinous junction at the level of the fracture fragment. The ruptured tendon was repaired using a modified Krackow technique at the time of fracture fixation. The repair was protected in plaster of Paris prior to referral to the paediatric hand clinic. The patient made a full recovery. Flexor tendon injury is a rare but potentially devastating consequence of acute forearm fractures. High energy trauma, significant volar angulation of the fracture fragment and clinical signs of flexor tendon injury should raise suspicion of this injury. A high index of suspicion in conjunction with repeat clinical examination of flexor tendon function should be performed before opting for closed management or intramedullary nailing in paediatric patients.

Post-surgical rehabilitative approach to fragility fractures.

PubMed

Gimigliano, F; Iolascon, G; Riccio, I; Frizzi, L; Gimigliano, R

2013-10-01

Osteoporosis is a skeletal disorder characterized by compromised bone strength predisposing to an increased risk of fracture. The most frequent sites of fragility fractures are the hip, the distal radius, the spine, the proximal humerus, and the ankle. In most cases, a surgical approach with subsequent rehabilitative treatment is required. The general aims of rehabilitation are to increase functioning and improve patients' activities, participation level, and quality of life.

Osteosarcoma in a young Great Dane dog.

PubMed

Evans, L B

1983-12-01

A 10-month-old Great Dane dog was presented showing lameness in the left foreleg. Radiographic examination revealed a severe bony reaction of the left distal radius and ulna. The reaction together with associated soft tissue swelling increased dramatically over a 6 week period. A diagnosis of osteogenic sarcoma was confirmed histologically and the dog was euthanased. Metastases were found post mortem in the left prescapular lymph node and left lung.

Gallium nitrate: effects on cartilage during limb regeneration in the axolotl, Ambystoma mexicanum.

PubMed

Tassava, Roy A; Mendenhall, Luciara; Apseloff, Glen; Gerber, Nicholas

2002-09-01

Gallium nitrate, a drug shown to have efficacy in Paget's disease of bone, hypercalcemia of malignancy, and a variety of experimental autoimmune diseases, also inhibits the growth of some types of cancer. We examined dose and timing of administration of gallium nitrate on limb regeneration in the Mexican axolotl, Ambystoma mexicanum. Administered by intraperitoneal injection, gallium nitrate inhibited limb regeneration in a dose-dependent manner. Gallium nitrate initially suppressed epithelial wound healing and subsequently distorted both anterior-posterior and proximo-distal chondrogenic patterns. Gallium nitrate given at three days after amputation severely inhibited regeneration at high doses (6.25 mg/axolotl) and altered the normal patterning of the regenerates at low doses (3.75 mg/axolotl). Administration of 6.25 mg of gallium nitrate at four or 14 days prior to amputation also inhibited regeneration. In amputated limbs of gallium-treated axolotls, the chondrocytes were lost from inside the radius/ulna. Limbs that regenerated after gallium treatment was terminated showed blastema formation preferentially over the ulna. New cartilage of the regenerate often attached to the sides of the existing radius/ulna proximally into the stump and less so to the distal cut ends. J. Exp. Zool. 293:384-394, 2002. Copyright 2002 Wiley-Liss, Inc.

Measurement of the effect of playground surface materials on hand impact forces during upper limb fall arrests.

PubMed

Choi, Woochol J; Kaur, Harjinder; Robinovitch, Stephen N

2014-04-01

Distal radius fractures are common on playgrounds. Yet current guidelines for the selection of playground surface materials are based only on protection against fall-related head injuries. We conducted "torso release" experiments to determine how common playground surface materials affect impact force applied to the hand during upper limb fall arrests. Trials were acquired for falls onto a rigid surface, and onto five common playground surface materials: engineered wood fiber, gravel, mulch, rubber tile, and sand. Measures were acquired for arm angles of 20 and 40 degrees from the vertical. Playground surface materials influenced the peak resultant and vertical force (P<.001), but not the peak horizontal force (P=.159). When compared with the rigid condition, peak resultant force was reduced 17% by sand (from 1039 to 864 N), 16% by gravel, 7% by mulch, 5% by engineered wood fiber, and 2% by rubber tile. The best performing surface provided only a 17% reduction in peak resultant force. These results help to explain the lack of convincing evidence from clinical studies on the effectiveness of playground surface materials in preventing distal radius fractures during playground falls, and highlight the need to develop playground surface materials that provide improved protection against these injuries.

AO Distal Radius Fracture Classification: Global Perspective on Observer Agreement.

PubMed

Jayakumar, Prakash; Teunis, Teun; Giménez, Beatriz Bravo; Verstreken, Frederik; Di Mascio, Livio; Jupiter, Jesse B

2017-02-01

Background  The primary objective of this study was to test interobserver reliability when classifying fractures by consensus by AO types and groups among a large international group of surgeons. Secondarily, we assessed the difference in inter- and intraobserver agreement of the AO classification in relation to geographical location, level of training, and subspecialty. Methods  A randomized set of radiographic and computed tomographic images from a consecutive series of 96 distal radius fractures (DRFs), treated between October 2010 and April 2013, was classified using an electronic web-based portal by an invited group of participants on two occasions. Results  Interobserver reliability was substantial when classifying AO type A fractures but fair and moderate for type B and C fractures, respectively. No difference was observed by location, except for an apparent difference between participants from India and Australia classifying type B fractures. No statistically significant associations were observed comparing interobserver agreement by level of training and no differences were shown comparing subspecialties. Intra-rater reproducibility was "substantial" for fracture types and "fair" for fracture groups with no difference accounting for location, training level, or specialty. Conclusion  Improved definition of reliability and reproducibility of this classification may be achieved using large international groups of raters, empowering decision making on which system to utilize. Level of Evidence  Level III.

AO Distal Radius Fracture Classification: Global Perspective on Observer Agreement

PubMed Central

Jayakumar, Prakash; Teunis, Teun; Giménez, Beatriz Bravo; Verstreken, Frederik; Di Mascio, Livio; Jupiter, Jesse B.

2016-01-01

Background The primary objective of this study was to test interobserver reliability when classifying fractures by consensus by AO types and groups among a large international group of surgeons. Secondarily, we assessed the difference in inter- and intraobserver agreement of the AO classification in relation to geographical location, level of training, and subspecialty. Methods A randomized set of radiographic and computed tomographic images from a consecutive series of 96 distal radius fractures (DRFs), treated between October 2010 and April 2013, was classified using an electronic web-based portal by an invited group of participants on two occasions. Results Interobserver reliability was substantial when classifying AO type A fractures but fair and moderate for type B and C fractures, respectively. No difference was observed by location, except for an apparent difference between participants from India and Australia classifying type B fractures. No statistically significant associations were observed comparing interobserver agreement by level of training and no differences were shown comparing subspecialties. Intra-rater reproducibility was “substantial” for fracture types and “fair” for fracture groups with no difference accounting for location, training level, or specialty. Conclusion Improved definition of reliability and reproducibility of this classification may be achieved using large international groups of raters, empowering decision making on which system to utilize. Level of Evidence Level III PMID:28119795

Stability of anti-de sitter space in Einstein-Gauss-Bonnet gravity.

PubMed

Deppe, Nils; Kolly, Allison; Frey, Andrew; Kunstatter, Gabor

2015-02-20

Recently it has been argued that in Einstein gravity anti-de Sitter spacetime is unstable against the formation of black holes for a large class of arbitrarily small perturbations. We examine the effects of including a Gauss-Bonnet term. In five dimensions, spherically symmetric Einstein-Gauss-Bonnet gravity has two key features: Choptuik scaling exhibits a radius gap, and the mass function goes to a finite value as the horizon radius vanishes. These suggest that black holes will not form dynamically if the total mass-energy content of the spacetime is too small, thereby restoring the stability of anti-de Sitter spacetime in this context. We support this claim with numerical simulations and uncover a rich structure in horizon radii and formation times as a function of perturbation amplitude.

The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF).

PubMed

Joeris, Alexander; Lutz, Nicolas; Blumenthal, Andrea; Slongo, Theddy; Audigé, Laurent

2017-04-01

Background and purpose - To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the upper extremities of a representative population of children classified according to the PCCF. Patients and methods - We included children and adolescents (0-17 years old) diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at the university hospitals in Bern and Lausanne (Switzerland). Patient charts were retrospectively reviewed and fractures were classified from standard radiographs. Results - Of 2,292 upper extremity fractures in 2,203 children and adolescents, 26% involved the humerus and 74% involved the forearm. In the humerus, 61%, and in the forearm, 80% of single distal fractures involved the metaphysis. In adolescents, single humerus fractures were more often epiphyseal and diaphyseal fractures, and among adolescents radius fractures were more often epiphyseal fractures than in other age groups. 47% of combined forearm fractures were distal metaphyseal fractures. Only 0.7% of fractures could not be classified within 1 of the child-specific fracture patterns. Of the single epiphyseal fractures, 49% were Salter-Harris type-II (SH II) fractures; of these, 94% occurred in schoolchildren and adolescents. Of the metaphyseal fractures, 58% showed an incomplete fracture pattern. 89% of incomplete fractures affected the distal radius. Of the diaphyseal fractures, 32% were greenstick fractures. 24 Monteggia fractures occurred in pre-school children and schoolchildren, and 2 occurred in adolescents. Interpretation - The pattern of pediatric fractures in the upper extremity can be comprehensively described according to the PCCF. Prospective clinical studies are needed to determine its clinical relevance for treatment decisions and prognostication of outcome.

Impact of Weight Loss With Intragastric Balloon on Bone Density and Microstructure in Obese Adults.

PubMed

Madeira, Eduardo; Madeira, Miguel; Guedes, Erika Paniago; Mafort, Thiago Thomaz; Moreira, Rodrigo Oliveira; de Mendonça, Laura Maria Carvalho; Lima, Inayá Correa Barbosa; Neto, Leonardo Vieira; de Pinho, Paulo Roberto Alves; Lopes, Agnaldo José; Farias, Maria Lucia Fleiuss

2018-03-21

The historical concept that obesity protects against bone fractures has been questioned. Weight loss appears to reduce bone mineral density (BMD); however, the results in young adults are inconsistent, and data on the effects of weight loss on bone microstructure are limited. This study aimed to evaluate the impact of weight loss using an intragastric balloon (IGB) on bone density and microstructure. Forty obese patients with metabolic syndrome (mean age 35.1 ± 7.3 yr) used an IGB continuously for 6 mo. Laboratory tests, areal BMD, and body composition measurements via dual-energy X-ray absorptiometry, and volumetric BMD and bone microstructure measurements via high-resolution peripheral quantitative computed tomography were conducted before IGB placement and after IGB removal. The mean weight loss was 11.5%. After 6 mo, there were significant increases in vitamin D and carboxyterminal telopeptide of type 1 collagen levels. After IGB use, areal BMD increased in the spine but decreased in the total femur and the 33% radius. Cortical BMD increased in the distal radius but tended to decrease in the distal tibia. The observed trabecular bone loss in the distal tibia contributed to the decline in the total volumetric BMD at this site. There was a negative correlation between the changes in leptin levels and the measures of trabecular quality in the tibia on high-resolution peripheral quantitative computed tomography. Weight loss may negatively impact bone microstructure in young patients, especially for weight-bearing bones, in which obesity has a more prominent effect. Copyright © 2018 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF)

PubMed Central

Joeris, Alexander; Lutz, Nicolas; Blumenthal, Andrea; Slongo, Theddy; Audigé, Laurent

2017-01-01

Background and purpose To achieve a common understanding when dealing with long bone fractures in children, the AO Pediatric Comprehensive Classification of Long Bone Fractures (AO PCCF) was introduced in 2007. As part of its final validation, we present the most relevant fracture patterns in the upper extremities of a representative population of children classified according to the PCCF. Patients and methods We included children and adolescents (0–17 years old) diagnosed with 1 or more long bone fractures between January 2009 and December 2011 at the university hospitals in Bern and Lausanne (Switzerland). Patient charts were retrospectively reviewed and fractures were classified from standard radiographs. Results Of 2,292 upper extremity fractures in 2,203 children and adolescents, 26% involved the humerus and 74% involved the forearm. In the humerus, 61%, and in the forearm, 80% of single distal fractures involved the metaphysis. In adolescents, single humerus fractures were more often epiphyseal and diaphyseal fractures, and among adolescents radius fractures were more often epiphyseal fractures than in other age groups. 47% of combined forearm fractures were distal metaphyseal fractures. Only 0.7% of fractures could not be classified within 1 of the child-specific fracture patterns. Of the single epiphyseal fractures, 49% were Salter-Harris type-II (SH II) fractures; of these, 94% occurred in schoolchildren and adolescents. Of the metaphyseal fractures, 58% showed an incomplete fracture pattern. 89% of incomplete fractures affected the distal radius. Of the diaphyseal fractures, 32% were greenstick fractures. 24 Monteggia fractures occurred in pre-school children and schoolchildren, and 2 occurred in adolescents. Interpretation The pattern of pediatric fractures in the upper extremity can be comprehensively described according to the PCCF. Prospective clinical studies are needed to determine its clinical relevance for treatment decisions and prognostication of outcome. PMID:27882802

Are Elias 2-27's Spiral Arms Driven by Self-gravity, or by a Companion? A Comparative Spiral Morphology Study

NASA Astrophysics Data System (ADS)

Forgan, Duncan H.; Ilee, John D.; Meru, Farzana

2018-06-01

The spiral waves detected in the protostellar disk surrounding Elias 2-27 have been suggested as evidence of the disk being gravitationally unstable. However, previous work has shown that a massive, stable disk undergoing an encounter with a massive companion are also consistent with the observations. We compare the spiral morphology of smoothed particle hydrodynamic simulations modeling both cases. The gravitationally unstable disk produces symmetric, tightly wound spiral arms with constant pitch angle, as predicted by the literature. The companion disk’s arms are asymmetric, with pitch angles that increase with radius. However, these arms are not well-fitted by standard analytic expressions, due to the high disk mass and relatively low companion mass. We note that differences (or indeed similarities) in morphology between pairs of spirals is a crucial discriminant between scenarios for Elias 2-27, and hence future studies must fit spiral arms individually. If Elias 2-27 continues to show symmetric tightly wound spiral arms in future observations, then we posit that it is the first observed example of a gravitationally unstable protostellar disk.

Axial and appendicular bone density predict fractures in older women

NASA Technical Reports Server (NTRS)

Black, D. M.; Cummings, S. R.; Genant, H. K.; Nevitt, M. C.; Palermo, L.; Browner, W.

1992-01-01

To determine whether measurement of hip and spine bone mass by dual-energy x-ray absorptiometry (DEXA) predicts fractures in women and to compare the predictive value of DEXA with that of single-photon absorptiometry (SPA) of appendicular sites, we prospectively studied 8134 nonblack women age 65 years and older who had both DEXA and SPA measurements of bone mass. A total of 208 nonspine fractures, including 37 wrist fractures, occurred during the follow-up period, which averaged 0.7 years. The risk of fracture was inversely related to bone density at all measurement sites. After adjusting for age, the relative risks per decrease of 1 standard deviation in bone density for the occurrence of any fracture was 1.40 for measurement at the proximal femur (95% confidence interval 1.20-1.63) and 1.35 (1.15-1.58) for measurement at the spine. Results were similar for all regions of the proximal femur as well as SPA measurements at the calcaneus, distal radius, and proximal radius. None of these measurements was a significantly better predictor of fractures than the others. Furthermore, measurement of the distal radius was not a better predictor of wrist fracture (relative risk 1.64: 95% CI 1.13-2.37) than other sites, such as the lumbar spine (RR 1.56; CI 1.07-2.26), the femoral neck (RR 1.65; CI 1.12-2.41), or the calcaneus (RR 1.83; CI 1.26-2.64). We conclude that the inverse relationship between bone mass and risk of fracture in older women is similar for absorptiometric measurements made at the hip, spine, and appendicular sites.

Follicle-stimulating hormone is independently associated with lean mass but not BMD in younger postmenopausal women

PubMed Central

Gourlay, Margaret L.; Specker, Bonny L.; Li, Chenxi; Hammett-Stabler, Catherine A.; Renner, Jordan B.; Rubin, Janet E.

2011-01-01

Purpose Increased follicle-stimulating hormone (FSH) has been associated with lower bone mineral density (BMD) in animal models and longitudinal studies of women, but a direct effect has not been demonstrated. Methods We tested associations between FSH, non-bone body composition measures and BMD in 94 younger (aged 50 to 64 years) postmenopausal women without current use of hormone therapy, adjusting for sex hormone concentrations and clinical risk factors for osteoporosis. Lean mass, fat mass and areal BMD (aBMD) at the spine, femoral neck and total hip were measured using dual energy X-ray absorptiometry (DXA). Volumetric BMD (vBMD) was measured at the distal radius using peripheral quantitative computed tomography (pQCT). Results: FSH was inversely correlated with lean and fat mass, bioavailable estradiol, spine and hip aBMD, and vBMD at the ultradistal radius. In the multivariable analysis, FSH was independently associated with lean mass (β= −0.099, p=0.005) after adjustment for age, race, years since menopause, bioavailable estradiol, bioavailable testosterone, LH, PTH, SHBG and urine N-telopeptide. FSH showed no statistically significant association with aBMD at any site or pQCT measures at the distal radius in adjusted models. Race was independently associated with aBMD, and race and urine N-telopeptide were independently associated with bone area and vBMD. Conclusions After adjustment for hormonal measures and osteoporosis risk factors, higher concentrations of FSH were independently associated with lower lean mass, but not with BMD. Previously reported correlations between FSH and BMD might have been due to indirect associations via lean mass or weight. PMID:22086136

Scenario development for high β p low torque plasma with q min above 2 and large-radius internal transport barrier in DIII-D

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

Ding, S.; Xu, G. S.; Wang, Q.

A recent experiment on DIII-D, which was conducted by the joint research team from DIII-D and EAST, has extended the previous high β p, high q min regime, which has been tested in the 2013 DIII-D/EAST joint experiment, to inductive operation at higher plasma current (I p=0.8 MA) and significantly higher normalized fusion performance (G = H 89β N/=qmore » $$2\\atop{95}$$ = 0.16). The experiment aims at exploring high performance scenario with q min > 2 and reduced torque for long pulse operation, which can be potentially extrapolated to EAST. The effort was largely motivated by the interest in developing a feasible scenario for long-pulse high performance operation with low torque on EAST. Very high confinement, H 89 = 3.5 or H 98,y2 = 2.1 with β N ~ 3.0, has been achieved transiently in this experiment together with q min > 2 and reduced NBI torque (3~5 N-m). The excellent confinement is associated with the spontaneous formation of an internal transport barrier (ITB) in plasmas with I p=0.8 MA at large minor radius (normalized p ~ 0.7) in all channels (n e, T e, T i, V Φ, especially strong in the T e channel). Fluctuation measurements show a significant reduction in the fluctuation levels, including AE modes and broadband turbulence, at the location where an ITB forms. Linear gyrokinetic simulations also support the decrease of the growth rate of the most unstable mode during strong ITB formation. The simulation implies that strong suppression of turbulence and a positive feedback loop may be active in this process and is responsible for the spontaneous formation of large-radius ITB. Finally, in an unstable ITB phase, an ELM crash is observed to have a positive effect on transient formation of large-radius ITB. The formation of this kind of ITB is found to have a shielding (protecting) effect on the core plasma while isolating the perturbation due to ELM crash.« less

Scenario development for high β p low torque plasma with q min above 2 and large-radius internal transport barrier in DIII-D

DOE PAGES

Ding, S.; Xu, G. S.; Wang, Q.; ...

2016-09-30

A recent experiment on DIII-D, which was conducted by the joint research team from DIII-D and EAST, has extended the previous high β p, high q min regime, which has been tested in the 2013 DIII-D/EAST joint experiment, to inductive operation at higher plasma current (I p=0.8 MA) and significantly higher normalized fusion performance (G = H 89β N/=qmore » $$2\\atop{95}$$ = 0.16). The experiment aims at exploring high performance scenario with q min > 2 and reduced torque for long pulse operation, which can be potentially extrapolated to EAST. The effort was largely motivated by the interest in developing a feasible scenario for long-pulse high performance operation with low torque on EAST. Very high confinement, H 89 = 3.5 or H 98,y2 = 2.1 with β N ~ 3.0, has been achieved transiently in this experiment together with q min > 2 and reduced NBI torque (3~5 N-m). The excellent confinement is associated with the spontaneous formation of an internal transport barrier (ITB) in plasmas with I p=0.8 MA at large minor radius (normalized p ~ 0.7) in all channels (n e, T e, T i, V Φ, especially strong in the T e channel). Fluctuation measurements show a significant reduction in the fluctuation levels, including AE modes and broadband turbulence, at the location where an ITB forms. Linear gyrokinetic simulations also support the decrease of the growth rate of the most unstable mode during strong ITB formation. The simulation implies that strong suppression of turbulence and a positive feedback loop may be active in this process and is responsible for the spontaneous formation of large-radius ITB. Finally, in an unstable ITB phase, an ELM crash is observed to have a positive effect on transient formation of large-radius ITB. The formation of this kind of ITB is found to have a shielding (protecting) effect on the core plasma while isolating the perturbation due to ELM crash.« less

Open segmental fracture of both bone forearm and dislocation of ipsilateral elbow with extruded middle segment radius

PubMed Central

Kumar, Pawan; Manjhi, Lal Bahadur; Rajak, Ramesh Lal

2013-01-01

Extruded middle segment of radius with open segmental fracture both bone forearm and dislocation of ipsilateral elbow is a rare injury. A 12-year-old child presented to us within 4 hours following fall from tree. The child's mother was carrying a 12-cm-long extruded soiled segment of radius. The extruded bone was thoroughly washed. The medullary cavity was properly syringed with antiseptic solution. The bone was autoclaved and put in the muscle plane of the distal forearm after debridement of the wound. After 5 days, a 2.5-mm K-wire was introduced by retrograde method into the proximal radius by passing through the extruded segment. Another 2.5-mm K-wire was passed in ulna. The limb was evaluated clinicoradiologically every 2 weeks. The wound was healed by primary intention. At 4 months, the reposed bone appeared less dense radiologically and K-wire seemed to be out of the bone. In the subsequent months, the roentgenograms show remodeling of the extruded fragment. After 20 weeks, the K-wires were removed (first ulnar and then radial). Complete union was achieved with full range of movement except loss of few degrees of extension of elbow and thumb. This case is reported to show a good outcome following successful incorporation of an extruded segment of radius in an open fracture. PMID:23798764

Correction to: The minimally invasive flexor carpi radialis approach: a new perspective for distal radius fractures.

PubMed

Igeta, Yuka; Vernet, Paul; Facca, Sybille; Naroura, Ismaël; Hidalgo Diaz, Juan José; Liverneaux, Philippe A

2018-03-03

With regards to Juan José Hidalgo Diaz, fifth author. The author's name is incorrectly listed on Pub-Med. The first and last name has been mixed up.Correct first name is: JJ (on PubMed: JJH.).Correct last name is: Hidalgo Diaz (on PubMed: Diaz).On SpringerLink the name is listed correctly, but on PubMed he is listed as Diaz JJH.

Unicameral bone cyst of the scaphoid: a report of two cases.

PubMed

Javdan, Mohammad; Zarezadeh, Abolghasem; Gaulke, Raulf; Eshaghi, Mohammad Amin; Shemshaki, Hamidreza

2012-08-01

Unicameral bone cysts are benign, fluid-filled lesions that occur mostly in long bones (proximal humerus, 50-60%; femur, 30%) of male children aged 5 to 15 years. Occurrence in the scaphoid of an adult is rare. We report 2 such patients who presented with wrist pain, with and without a history of trauma. Both underwent curettage and bone grafting (harvested from the distal radius) and achieved good functional recovery.

Genetic and environmental variances of bone microarchitecture and bone remodeling markers: a twin study.

PubMed

Bjørnerem, Åshild; Bui, Minh; Wang, Xiaofang; Ghasem-Zadeh, Ali; Hopper, John L; Zebaze, Roger; Seeman, Ego

2015-03-01

All genetic and environmental factors contributing to differences in bone structure between individuals mediate their effects through the final common cellular pathway of bone modeling and remodeling. We hypothesized that genetic factors account for most of the population variance of cortical and trabecular microstructure, in particular intracortical porosity and medullary size - void volumes (porosity), which establish the internal bone surface areas or interfaces upon which modeling and remodeling deposit or remove bone to configure bone microarchitecture. Microarchitecture of the distal tibia and distal radius and remodeling markers were measured for 95 monozygotic (MZ) and 66 dizygotic (DZ) white female twin pairs aged 40 to 61 years. Images obtained using high-resolution peripheral quantitative computed tomography were analyzed using StrAx1.0, a nonthreshold-based software that quantifies cortical matrix and porosity. Genetic and environmental components of variance were estimated under the assumptions of the classic twin model. The data were consistent with the proportion of variance accounted for by genetic factors being: 72% to 81% (standard errors ∼18%) for the distal tibial total, cortical, and medullary cross-sectional area (CSA); 67% and 61% for total cortical porosity, before and after adjusting for total CSA, respectively; 51% for trabecular volumetric bone mineral density (vBMD; all p < 0.001). For the corresponding distal radius traits, genetic factors accounted for 47% to 68% of the variance (all p ≤ 0.001). Cross-twin cross-trait correlations between tibial cortical porosity and medullary CSA were higher for MZ (rMZ  = 0.49) than DZ (rDZ  = 0.27) pairs before (p = 0.024), but not after (p = 0.258), adjusting for total CSA. For the remodeling markers, the data were consistent with genetic factors accounting for 55% to 62% of the variance. We infer that middle-aged women differ in their bone microarchitecture and remodeling markers more because of differences in their genetic factors than differences in their environment. © 2014 American Society for Bone and Mineral Research.

Slipped Distal Femoral Epiphysis in Congenital Insensitivity to Pain.

PubMed

Shaikh, M Javed; Rex, C; Vignesh, R; Chavan, Madhav

2016-01-01

Congenital insensitivity to pain (CIP) is a rare disorder, and often presents to an orthopaedic surgeon as recurrent fractures, dislocations, pseudoarthrosis, osteomyelitis etc. Here, we report a case of congenital insensitivity to pain presenting with distal femoral physeal separation in a child. A 12-year-old girl child came with complaints of limp while walking and swelling in the left knee for past 5 weeks. Mother gave a history that the girl is a known case of congenital insensitivity to pain with clear history of no pain on intramuscular injection since birth. She was born of consanguineous marriage and had no significant trauma, fever, other joint involvement or any features of rheumatism. On local examination, she had no bony tenderness, mild warmth, and moderate knee effusion with restricted range of movement. Plain radiograph showed epiphysiolysis of distal femur with widening of physis. Examination under anaesthesia demonstrated gross movement indicating lower femoral physeal separation. This unstable distal femoral epiphysis was treated under general anaesthesia with closed reduction, percutaneous cross pinning and above knee plaster cast. Congenital insensitivity to pain (CIP) is a rare disorder to diagnose. Emphasis is given on early diagnosis of orthopaedic problems and prompt treatment, educating parents and prevention of accidents. Physeal separation without significant trauma must prompt an orthopaedic surgeon to think about congenital insensitivity to pain as a differential diagnosis.

Proconsul heseloni distal radial and ulnar epiphyses from the Kaswanga Primate Site, Rusinga Island, Kenya.

PubMed

Daver, Guillaume; Nakatsukasa, Masato

2015-03-01

Only two distal epiphyses of a radius and ulna are consensually attributed to the holotype skeleton of Proconsul heseloni, KNM-RU 2036. Here, we describe seven adult and immature distal antebrachial (radial and ulnar) epiphyses from two other individuals of P. heseloni from the Lower Miocene deposits of the Kaswanga Primate Site (KPS), Rusinga Island, Kenya. Because KNM-RU 2036 and KNM-KPS individuals III and VIII are conspecific and penecontemporaneous, their comparison provides the opportunity i) to characterize, for the first time, the morphological variation of the distal radioulnar joint in a Miocene ape, P. heseloni, and ii) to investigate the functional and evolutionary implications. Our results show that the distal antebrachial epiphyses of KNM-KPS III and VIII correspond to stages of bone maturation that are more advanced than those of KNM-RU 2036 (larger articulations and sharper articular borders and ligament attachments that are more developed). Accordingly, functional interpretations based solely on the skeleton of KNM-RU 2036 have involved an underestimation of the forearm rotation abilities of P. heseloni. In particular, the KPS fossils do not exhibit the primitive morphology of distal radioulnar syndesmosis, as those of KNM-RU 2036 and most nonhominoid primates, but rather the morphology of an incipient diarthrosis (as in extant lorisines and hominoids). The distal radioulnar diarthrosis permits more mobility and maintenance of the wrist during repeated and slow rotation of the forearms, which facilitates any form of quadrupedal locomotion on discontinuous and variably oriented supports. By providing the oldest evidence of a distal radioulnar joint in an early Miocene hominoid, the main conclusions of this study are consistent with the role of cautious climbing as a prerequisite step for the emergence of positional adaptations in apes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Why is the rapid burster different from all other galactic-bulge X-ray sources?

NASA Astrophysics Data System (ADS)

Milgrom, M.

1987-01-01

It is suggested that the rapid X-ray burster exhibits unique behavior because it contains a neutron star whose stellar radius is smaller than the minimum radius of a circular orbit that is stable according to general relativity. The star accretes from a disk that extends down to the last stable orbit. In this state, the disk is unstable against a rapid fall and accretion of its innermost part onto the star. The sudden dumping of mass gives rise to a burst of X-rays. The disk then heals, refilling the inner region at a pace that is dictated mainly by the global accretion rate, in order to ready itself for the next burst. In all other galactic-bulge-type sources, the neutron star is larger than the last stable orbit.

Packings of a charged line on a sphere.

PubMed

Alben, Silas

2008-12-01

We find equilibrium configurations of open and closed lines of charge on a sphere, and track them with respect to varying sphere radius. Closed lines transition from a circle to a spiral-like shape through two low-wave-number bifurcations-"baseball seam" and "twist"-which minimize Coulomb energy. The spiral shape is the unique stable equilibrium of the closed line. Other unstable equilibria arise through tip-splitting events. An open line transitions smoothly from an arc of a great circle to a spiral as the sphere radius decreases. Under repulsive potentials with faster-than-Coulomb power-law decay, the spiral is tighter in initial stages of sphere shrinkage, but at later stages of shrinkage the equilibria for all repulsive potentials converge on a spiral with uniform spacing between turns. Multiple stable equilibria of the open line are observed.

Upper-extremity phocomelia reexamined: a longitudinal dysplasia.

PubMed

Goldfarb, Charles A; Manske, Paul R; Busa, Riccardo; Mills, Janith; Carter, Peter; Ezaki, Marybeth

2005-12-01

In contrast to longitudinal deficiencies, phocomelia is considered a transverse, intercalated segmental dysplasia. Most patients demonstrate severe, but not otherwise classifiable, upper-extremity deformities, which usually cannot be placed into one of three previously described phocomelia groups. Additionally, these phocomelic extremities do not demonstrate true segmental deficits; the limb is also abnormal proximal and distal to the segmental defect. The purpose of this investigation was to present evidence that upper-extremity abnormalities in patients previously diagnosed as having phocomelia in fact represent a proximal continuum of radial or ulnar longitudinal dysplasia. The charts and radiographs of forty-one patients (sixty extremities) diagnosed as having upper-extremity phocomelia were reviewed retrospectively. On the basis of the findings on the radiographs, the disorders were categorized into three groups: (1) proximal radial longitudinal dysplasia, which was characterized by an absent proximal part of the humerus, a nearly normal distal part of the humerus, a completely absent radius, and a radial-sided hand dysplasia; (2) proximal ulnar longitudinal dysplasia, characterized by a short one-bone upper extremity that bifurcated distally and by severe hand abnormalities compatible with ulnar dysplasia; and (3) severe combined dysplasia, with type A characterized by an absence of the forearm segment (i.e., the radius and ulna) and type B characterized by absence of the arm and forearm (i.e., the hand attached to the thorax). Twenty-nine limbs in sixteen patients could be classified as having proximal radial longitudinal dysplasia. Systemic medical conditions such as thrombocytopenia-absent radius syndrome were common in those patients, but additional musculoskeletal conditions were rare. Twenty limbs in seventeen patients could be classified as having proximal ulnar longitudinal dysplasia. Associated musculoskeletal abnormalities, such as proximal femoral focal deficiency, were common in those patients. Eleven limbs in ten patients were identified as having severe combined dysplasia, which was type A in seven of them and type B in four. Four patients with severe combined dysplasia had congenital cardiac anomalies, and four had associated musculoskeletal abnormalities. Three of the four patients with the type-B disorder had a contralateral ulnar longitudinal dysplasia. We propose that cases previously classified as upper-extremity phocomelia represent a spectrum of severe longitudinal dysplasia, as none of the sixty extremities that we studied demonstrated a true intercalary deficiency. These findings have both developmental and genetic implications.

Unique effects of energy versus estrogen deficiency on multiple components of bone strength in exercising women.

PubMed

Southmayd, E A; Mallinson, R J; Williams, N I; Mallinson, D J; De Souza, M J

2017-04-01

Many female athletes are energy and/or estrogen deficient, but the independent effects on bone health have not been isolated. Energy deficiency was detrimental at the tibia while estrogen deficiency was detrimental at the radius. Nutrition must be considered alongside menstrual recovery when addressing compromised bone health in female athletes. The purpose of this study was to describe volumetric bone mineral density (vBMD), bone geometry, and estimated bone strength in exercising women (n = 60) grouped according to energy status (energy replete (EnR: n = 30) vs. energy deficient (EnD: n = 30)) and estrogen status (estrogen replete (E 2 R: n = 33) vs. estrogen deficient (E 2 D: n = 27)), resulting in four distinct groups: EnR + E 2 R (n = 17), EnR + E 2 D (n = 13), EnD + E 2 R (n = 16), EnD + E 2 D (n = 14). Energy status was determined using the ratio of measured to predicted resting energy expenditure (mREE/pREE). Estrogen status was based on self-reported menstrual status confirmed by daily evaluation of urinary estrone-1-glucoronide (E1G), pregnanediol glucuronide (PdG), and luteinizing hormone (LH). Eumenorrheic women were considered E 2 R, amenorrheic women were E 2 D, and oligomenorrheic women were categorized based on history of menses in the past year. Bone was assessed using peripheral quantitative computed tomography (pQCT). EnD women exhibited lower total vBMD, trabecular vBMD, cortical area, and BSI at the distal tibia and lower total vBMD, smaller cortical area and cortical thickness, and larger endosteal circumference at the proximal tibia compared to EnR women (p < 0.042). E 2 D women had lower total and cortical vBMD, larger total and trabecular area, and lower BSI at the distal radius and lower cortical vBMD at the proximal radius compared to E 2 R women (p < 0.023). Energy and estrogen interacted to affect total and trabecular area at the distal tibia (p < 0.021). Efforts to correct energy deficiency, which in turn may promote reproductive health, are warranted in order to address the unique contributions of energy status versus estrogen status to bone health.

Effect of low appendicular lean mass, grip strength, and gait speed on the functional outcome after surgery for distal radius fractures.

PubMed

Roh, Young Hak; Noh, Jung Ho; Gong, Hyun Sik; Baek, Goo Hyun

2017-12-01

Patients with low appendicular lean mass plus slow gait speed or weak grip strength are at risk for poor functional recovery after surgery for distal radius fracture, even when they have similar radiologic outcomes. Loss of skeletal muscle mass and consequent loss in muscle function associate with aging, and this condition negatively impacts the activities of daily living and increases elderly individuals' frailty to falls. Thus, patients with low appendicular lean mass would show different functional recovery compared to those without this condition after surgery for distal radius fracture (DRF). This study compares the functional outcomes after surgery for DRF in patients with or without low appendicular lean mass plus slowness or weakness. A total of 157 patients older than 50 years of age with a DRF treated via volar plate fixation were enrolled in this prospective study. A definition of low appendicular lean mass with slowness or weakness was based on the consensus of the Asian Working Group for Sarcopenia. The researchers compared functional assessments (wrist range of motion and Michigan Hand Questionnaire [MHQ]) and radiographic assessments (radial inclination, volar tilt, ulnar variance, and articular congruity) 12 months after surgery between patients with and without low appendicular lean mass plus slowness or weakness. Multivariable regression analyses were performed to determine whether appendicular lean mass, grip strength, gait speed, patient demographic, or injury characteristics accounted for the functional outcomes. Patients with low appendicular lean mass plus slowness or weakness showed a significantly lower recovery of MHQ score than those in the control group throughout 12 months. There was no significant difference in the range of motion between the groups. The radiologic outcomes showed no significant difference between groups in terms of volar tilt, radial inclination, or ulnar variance. According to multivariable regression analysis, the poor recovery of MHQ score was associated with an increase in age, weak grip strength, and lower appendicular lean mass, and these three factors accounted for 37% of the variation in the MHQ scores. Patients with low appendicular lean mass plus slowness or weakness are at risk for poor functional recovery after surgery for DRF, even when they have similar radiologic outcomes.

Relative contributions of lean and fat mass to bone strength in young Hispanic and non-Hispanic girls.

PubMed

Hetherington-Rauth, Megan; Bea, Jennifer W; Blew, Robert M; Funk, Janet L; Hingle, Melanie D; Lee, Vinson R; Roe, Denise J; Wheeler, Mark D; Lohman, Timothy G; Going, Scott B

2018-05-22

With the high prevalence of childhood obesity, especially among Hispanic children, understanding how body weight and its components of lean and fat mass affect bone development is important, given that the amount of bone mineral accrued during childhood can determine osteoporosis risk later in life. The aim of this study was to assess the independent contributions of lean and fat mass on volumetric bone mineral density (vBMD), geometry, and strength in both weight-bearing and non-weight-bearing bones of Hispanic and non-Hispanic girls. Bone vBMD, geometry, and strength were assessed at the 20% distal femur, the 4% and 66% distal tibia, and the 66% distal radius of the non-dominant limb of 326, 9- to 12-year-old girls using peripheral quantitative computed tomography (pQCT). Total body lean and fat mass were measured by dual-energy x-ray absorptiometry (DXA). Multiple linear regression was used to assess the independent relationships of fat and lean mass with pQCT bone measures while adjusting for relevant confounders. Potential interactions between ethnicity and both fat and lean mass were also tested. Lean mass was a significant positive contributor to all bone outcomes (p < 0.05) with the exception of vBMD at diaphyseal sites. Fat mass was a significant contributor to bone strength at weight bearing sites, but did not significantly contribute to bone strength at the non-weight bearing radius and was negatively associated with radius cortical content and thickness. Bone measures did not significantly differ between Hispanic and non-Hispanic girls, although there was a significant interaction between ethnicity and fat mass with total bone area at the femur (p = 0.02) and 66% tibia (p = 0.005) as well as bone strength at the femur (p = 0.03). Lean mass is the main determinant of bone strength for appendicular skeletal sites. Fat mass contributes to bone strength in the weight-bearing skeleton but does not add to bone strength in non-weight-bearing locations and may potentially be detrimental. Bone vBMD, geometry, and strength did not differ between Hispanic and non-Hispanic girls; fat mass may be a stronger contributor to bone strength in weight-bearing bones of Hispanic girls compared to non-Hispanic. Copyright © 2018. Published by Elsevier Inc.

Variation in the Use of Therapy following Distal Radius Fractures in the United States

PubMed Central

Waljee, Jennifer F.; Zhong, Lin; Shauver, Melissa

2014-01-01

Background: Distal radius fractures (DRFs) are one of the most common injuries among the elderly, resulting in significant expense and disability. The specific aims of this study are (1) to examine rates of therapy following DRFs and (2) to identify those factors that influence utilization of therapy and time span between DRF treatment and therapy among a national cohort of elderly patients. Methods: We examined national use of physical and occupational therapy among all Medicare beneficiaries who suffered DRFs between January 1, 2007, and October 1, 2007, and assessed the effect of treatment, patient-related, and surgeon-related factors on utilization of therapy. Results: Overall, 20.6% of patients received either physical or occupational therapy following DRF. Use of therapy varied by DRF treatment, and patients who underwent open reduction and internal fixation were more likely to receive therapy compared with patients who received closed reduction. Patients who received open reduction and internal fixation were also referred to therapy earlier compared with patients who received external fixation, percutaneous pinning, and closed reduction. Surgeon specialization is associated with greater use of postoperative therapy. Patient predictors of therapy use include younger age, female sex, higher socioeconomic status, and fewer comorbidity conditions. Conclusion: Use of therapy following DRF varies significantly by both patient- and surgeon-related factors. Identifying patients who benefit from postinjury therapy can allow for better resource utilization following these common injuries. PMID:25289323

Electric potential distributions at the interface between plasmasheet clouds

NASA Technical Reports Server (NTRS)

Evans, D. S.; Roth, M.; Lemaire, J.

1987-01-01

At the interface between two plasma clouds with different densities, temperatures, and/or bulk velocities, there are large charge separation electric fields which can be modeled in the framework of a collisionless theory for tangential discontinuities. Two different classes of layers were identified: the first one corresponds to (stable) ion layers which are thicker than one ion Lamor radius; the second one corresponds to (unstable) electron layers which are only a few electron Larmor radii thick. It is suggested that these thin electron layers with large electric potential gradients (up to 400 mV/m) are the regions where large-amplitude electrostatic waves are spontaneously generated. These waves scatter the pitch angles of the ambient plasmasheet electron into the atmospheric loss cone. The unstable electron layers can therefore be considered as the seat of strong pitch angle scattering for the primary auroral electrons.

Non-axisymmetric viscous lower-branch modes in axisymmetric supersonic flows

NASA Technical Reports Server (NTRS)

Duck, Peter W.; Hall, Philip

1990-01-01

A previous paper by Duck and Hall (1989) considered the weakly nonlinear interaction of a pair of axisymmetric lower-branch Tollmien-Schlichting instabilities in cylindrical supersonic flows. Here, the possibility that nonaxisymmetric modes might also exist is investigated. In fact, it is found that such modes do exist and, on the basis of linear theory, it appears that these modes are the most important. The nonaxisymmetric modes are found to exist for flows around cylinders with nondimensional radius a less than some critical value a(c). This critical value a(c) is found to increase monotonically with the azimuthal wavenumber n of the disturbance, and it is found that unstable modes always occur in pairs. It is shown that, in general, instability in the form of lower-branch Tollmien-Schlichting waves will occur first for nonaxisymmetric modes and that, in the unstable regime, the largest growth rates correspond to the latter modes.

Nonaxisymmetric viscous lower branch modes in axisymmetric supersonic flows

NASA Technical Reports Server (NTRS)

Duck, Peter W.; Hall, Philip

1988-01-01

In a previous paper, the weakly nonlinear interaction of a pair of axisymmetric lower branch Tollmien-Schlichting instabilities in cylindrical supersonic flows was considered. Here the possibility that nonaxisymmetric modes might also exist is investigated. In fact, it is found that such modes do exist and, on the basis of linear theory, it appears that these modes are the most important. The nonaxisymmetric modes are found to exist for flows around cylinders with nondimensional radius alpha less than some critical value alpha sub c. This critical value alpha sub c is found to increase monotonically with the azimuthal wavenumber nu of the disturbance and it is found that unstable modes always occur in pairs. It is also shown that, in general, instability in the form of lower branch Tollmien-Schlichting waves will occur first for nonaxisymmetric modes and that in the unstable regime the largest growth rates correspond to the latter modes.

Outcome of Repair of Distal Radial and Ulnar Fractures in Dogs Weighing 4 kg or Less Using a 1.5-mm Locking Adaption Plate or 2.0-mm Limited Contact Dynamic Compression Plate.

PubMed

Nelson, Thomas A; Strom, Adam

2017-11-01

Objectives  Retrospective evaluation of repairing distal radial and ulnar fractures in small breed dogs with the Synthes 1.5-mm locking Adaption plate system and compare results in a similar group of patients repaired with the Synthes 2.0-mm limited contact-dynamic compression plate (LC-DCP). Methods  Electronic medical records from one specialty referral centre were reviewed from March 21, 2010, to October 9, 2015, for patients weighing less than or equal to 4 kg that had a distal one-third radial and ulnar fracture repaired with a Synthes 1.5-mm locking adaption plate or Synthes 2.0-mm LC-DCP. Further inclusion criteria included application of the plate to the cranial surface of the radius via open reduction and internal fixation. Results  Six 1.5-mm Adaption plates and 7 2.0-mm LC-DCPs were used to repair 13 distal radial and ulnar fractures in 12 dogs. There were three major complications in the 1.5-mm adaption plate group (one plate fracture, one screw pull-out and one fracture through a distal screw hole) and one major complication in the 2.0-mm LC-DCP group due to a re-fracture. All patients without a complication had good or excellent functional outcome. Clinical Significance  The authors recommend that the 1.5-mm Adaption plate be used only when a 2.0-mm LC-DCP would not allow for a minimum of two screws in the distal segment and at the discretion of the surgeon. Schattauer GmbH Stuttgart.

Effects of Calcium Spikes in the Layer 5 Pyramidal Neuron on Coincidence Detection and Activity Propagation

PubMed Central

Chua, Yansong; Morrison, Abigail

2016-01-01

The role of dendritic spiking mechanisms in neural processing is so far poorly understood. To investigate the role of calcium spikes in the functional properties of the single neuron and recurrent networks, we investigated a three compartment neuron model of the layer 5 pyramidal neuron with calcium dynamics in the distal compartment. By performing single neuron simulations with noisy synaptic input and occasional large coincident input at either just the distal compartment or at both somatic and distal compartments, we show that the presence of calcium spikes confers a substantial advantage for coincidence detection in the former case and a lesser advantage in the latter. We further show that the experimentally observed critical frequency phenomenon, in which action potentials triggered by stimuli near the soma above a certain frequency trigger a calcium spike at distal dendrites, leading to further somatic depolarization, is not exhibited by a neuron receiving realistically noisy synaptic input, and so is unlikely to be a necessary component of coincidence detection. We next investigate the effect of calcium spikes in propagation of spiking activities in a feed-forward network (FFN) embedded in a balanced recurrent network. The excitatory neurons in the network are again connected to either just the distal, or both somatic and distal compartments. With purely distal connectivity, activity propagation is stable and distinguishable for a large range of recurrent synaptic strengths if the feed-forward connections are sufficiently strong, but propagation does not occur in the absence of calcium spikes. When connections are made to both the somatic and the distal compartments, activity propagation is achieved for neurons with active calcium dynamics at a much smaller number of neurons per pool, compared to a network of passive neurons, but quickly becomes unstable as the strength of recurrent synapses increases. Activity propagation at higher scaling factors can be stabilized by increasing network inhibition or introducing short term depression in the excitatory synapses, but the signal to noise ratio remains low. Our results demonstrate that the interaction of synchrony with dendritic spiking mechanisms can have profound consequences for the dynamics on the single neuron and network level. PMID:27499740

Effects of Calcium Spikes in the Layer 5 Pyramidal Neuron on Coincidence Detection and Activity Propagation.

PubMed

Chua, Yansong; Morrison, Abigail

2016-01-01

The role of dendritic spiking mechanisms in neural processing is so far poorly understood. To investigate the role of calcium spikes in the functional properties of the single neuron and recurrent networks, we investigated a three compartment neuron model of the layer 5 pyramidal neuron with calcium dynamics in the distal compartment. By performing single neuron simulations with noisy synaptic input and occasional large coincident input at either just the distal compartment or at both somatic and distal compartments, we show that the presence of calcium spikes confers a substantial advantage for coincidence detection in the former case and a lesser advantage in the latter. We further show that the experimentally observed critical frequency phenomenon, in which action potentials triggered by stimuli near the soma above a certain frequency trigger a calcium spike at distal dendrites, leading to further somatic depolarization, is not exhibited by a neuron receiving realistically noisy synaptic input, and so is unlikely to be a necessary component of coincidence detection. We next investigate the effect of calcium spikes in propagation of spiking activities in a feed-forward network (FFN) embedded in a balanced recurrent network. The excitatory neurons in the network are again connected to either just the distal, or both somatic and distal compartments. With purely distal connectivity, activity propagation is stable and distinguishable for a large range of recurrent synaptic strengths if the feed-forward connections are sufficiently strong, but propagation does not occur in the absence of calcium spikes. When connections are made to both the somatic and the distal compartments, activity propagation is achieved for neurons with active calcium dynamics at a much smaller number of neurons per pool, compared to a network of passive neurons, but quickly becomes unstable as the strength of recurrent synapses increases. Activity propagation at higher scaling factors can be stabilized by increasing network inhibition or introducing short term depression in the excitatory synapses, but the signal to noise ratio remains low. Our results demonstrate that the interaction of synchrony with dendritic spiking mechanisms can have profound consequences for the dynamics on the single neuron and network level.

A Baroclinic Eddy Mixer: Supercritical Transformation of Compensated Eddies

NASA Astrophysics Data System (ADS)

Sutyrin, G.

2016-02-01

In contrast to many real-ocean rings and eddies, circular vortices with initial lower layer at rest tend to be highly unstable in idealized two-layer models, unless their radius is made small or the lower layer depth is made artificially large. Numerical simulations of unstable vortices with parameters typical for ocean eddies revealed strong deformations and pulsations of the vortex core in the two-layer setup due to development of corotating tripolar structures in the lower layer during their supercritical transformation. The addition of a middle layer with the uniform potential vorticity weakens vertical coupling between the upper and lower layer that enhances vortex stability and makes the vortex lifespan more realistic. Such a three-layer vortex model possesses smaller lower interface slope than the two-layer model that reduces the potential vorticity gradient in the lower layer and provides with less unstable configurations. While cyclonic eddies become only slightly deformed and look nearly circular when the middle layer with uniform potential vorticity is added, anticyclonic eddies tend to corotating and pulsating elongated states through potential vorticity stripping and stirring. Enhanced vortex stability in such three-layer setup has important implications for adequate representation of the energy transfer across scales.

Observational Signatures of a Kink-unstable Coronal Flux Rope Using Hinode /EIS

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

Snow, B.; Botha, G. J. J.; Régnier, S.

The signatures of energy release and energy transport for a kink-unstable coronal flux rope are investigated via forward modeling. Synthetic intensity and Doppler maps are generated from a 3D numerical simulation. The CHIANTI database is used to compute intensities for three Hinode /EIS emission lines that cover the thermal range of the loop. The intensities and Doppler velocities at simulation-resolution are spatially degraded to the Hinode /EIS pixel size (1″), convolved using a Gaussian point-spread function (3″), and exposed for a characteristic time of 50 s. The synthetic images generated for rasters (moving slit) and sit-and-stare (stationary slit) are analyzedmore » to find the signatures of the twisted flux and the associated instability. We find that there are several qualities of a kink-unstable coronal flux rope that can be detected observationally using Hinode /EIS, namely the growth of the loop radius, the increase in intensity toward the radial edge of the loop, and the Doppler velocity following an internal twisted magnetic field line. However, EIS cannot resolve the small, transient features present in the simulation, such as sites of small-scale reconnection (e.g., nanoflares).« less

Physical analysis of the process of cavitation in xylem sap.

PubMed

Shen, Fanyi; Gao, Rongfu; Liu, Wenji; Zhang, Wenjie

2002-06-01

Recent studies have confirmed that cavitation in xylem is caused by air bubbles. We analyzed expansion of a preexistent bubble adhering to a crack in a conduit wall and a bubble formed by the passage of air through a pore of a pit membrane, a process known as air seeding. We consider that there are two equilibrium states for a very small air bubble in the xylem: one is temporarily stable with a bubble radius r1 at point s1 on the curve P(r) relating pressure within the bubble (P) with bubble radius (r); the other is unstable with a bubble radius r2 at point s2 on Pr (where r1 < r2). In each equilibrium state, the bubble collapse pressure (2sigma/r, where sigma is surface tension of water) is balanced by the pressure difference across its surface. In the case of a bubble from a crack in a conduit wall, which is initially at point s1, expansion will occur steadily as water potential decreases. The bubble will burst only if the xylem pressure drops below a threshold value. A formula giving the threshold pressure for bubble bursting is proposed. In the case of an air seed entering a xylem conduit through a pore in a pit membrane, its initial radius may be r2 (i.e., the radius of the pore by which the air seed entered the vessel) at point s2 on Pr. Because the bubble is in an unstable equilibrium when entering the conduit, it can either expand or contract to point s1. As water vaporizes into the air bubble at s2, P rises until it exceeds the gas pressure that keeps the bubble in equilibrium, at which point the bubble will burst and induce a cavitation event in accordance with the air-seeding hypothesis. However, other possible perturbations could make the air-seeded bubble contract to s1, in which case the bubble will burst at a threshold pressure proposed for a bubble expanding from a crack in a conduit wall. For this reason some cavitation events may take place at a xylem threshold pressure (Pl'*) other than that determined by the formula, Plp'* = -2sigma/rp, proposed by Sperry and Tyree (1988), which is applicable only to air-seeded bubbles at s2. The more general formula we propose for calculating the threshold pressure for bubble breaking is consistent with the results of published experiments.

Magnetorotational instability in protoplanetary discs

NASA Astrophysics Data System (ADS)

Salmeron, Raquel; Wardle, Mark

2005-07-01

We investigate the linear growth and vertical structure of the magnetorotational instability (MRI) in weakly ionized, stratified accretion discs. The magnetic field is initially vertical and dust grains are assumed to have settled towards the mid-plane, so charges are carried by electrons and ions only. Solutions are obtained at representative radial locations from the central protostar for different choices of the initial magnetic field strength, sources of ionization, disc structure and configuration of the conductivity tensor. The MRI is active over a wide range of magnetic field strengths and fluid conditions in low-conductivity discs. Moreover, no evidence was found of a low-limit field strength below which unstable modes do not exist. For the minimum-mass solar nebula model, incorporating cosmic ray ionization, perturbations grow at 1 au for B<~ 8 G. For a significant subset of these strengths (200mG <~B<~ 5G), the maximum growth rate is of the order of the ideal magnetohydrodynamic (MHD) rate (0.75Ω). Hall conductivity modifies the structure and growth rate of global unstable modes at 1 au for all magnetic field strengths that support MRI. As a result, at this radius, modes obtained with a full conductivity tensor grow faster and are active over a more extended cross-section of the disc than perturbations in the ambipolar diffusion limit. For relatively strong fields (e.g. B>~ 200 mG), ambipolar diffusion alters the envelope shapes of the unstable modes, which peak at an intermediate height, instead of being mostly flat as modes in the Hall limit are in this region of parameter space. Similarly, when cosmic rays are assumed to be excluded from the disc by the winds emitted by the magnetically active protostar, unstable modes grow at this radius for B<~ 2 G. For strong fields, perturbations exhibit a kink at the height where X-ray ionization becomes active. Finally, for R= 5 au (10 au), unstable modes exist for B<~ 800 mG (B<~ 250 mG) and the maximum growth rate is close to the ideal-MHD rate for 20 <~B<~ 500 mG (2 <~B<~ 50 mG). Similarly, perturbations incorporating Hall conductivity have a higher wavenumber and grow faster than solutions in the ambipolar diffusion limit for B<~ 100 mG (B<~ 10 mG). Unstable modes grow even at the mid-plane for B>~ 100 mG (B~ 1 mG), but for weaker fields, a small dead region exists. This study shows that, despite the low magnetic coupling, the magnetic field is dynamically important for a large range of fluid conditions and field strengths in protostellar discs. An example of such magnetic activity is the generation of MRI unstable modes, which are supported at 1 au for field strengths up to a few gauss. Hall diffusion largely determines the structure and growth rate of these perturbations for all studied radii. At radii of order 1 au, in particular, it is crucial to incorporate the full conductivity tensor in the analysis of this instability and more generally in studies of the dynamics of astrophysical discs.

Relativistic Bose-Einstein condensates thin-shell wormholes

NASA Astrophysics Data System (ADS)

Richarte, M. G.; Salako, I. G.; Graça, J. P. Morais; Moradpour, H.; Övgün, Ali

2017-10-01

We construct traversable thin-shell wormholes which are asymptotically Ads/dS applying the cut and paste procedure for the case of an acoustic metric created by a relativistic Bose-Einstein condensate. We examine several definitions of the flare-out condition along with the violation or not of the energy conditions for such relativistic geometries. Under reasonable assumptions about the equation of state of the matter located at the shell, we concentrate on the mechanical stability of wormholes under radial perturbation preserving the original spherical symmetry. To do so, we consider linearized perturbations around static solutions. We obtain that dS acoustic wormholes remain stable under radial perturbations as long as they have small radius; such wormholes with finite radius do not violate the strong/null energy condition. Besides, we show that stable Ads wormhole satisfy some of the energy conditions whereas unstable Ads wormhole with large radii violate them.

Nuclear surface diffuseness revealed in nucleon-nucleus diffraction

NASA Astrophysics Data System (ADS)

Hatakeyama, S.; Horiuchi, W.; Kohama, A.

2018-05-01

The nuclear surface provides useful information on nuclear radius, nuclear structure, as well as properties of nuclear matter. We discuss the relationship between the nuclear surface diffuseness and elastic scattering differential cross section at the first diffraction peak of high-energy nucleon-nucleus scattering as an efficient tool in order to extract the nuclear surface information from limited experimental data involving short-lived unstable nuclei. The high-energy reaction is described by a reliable microscopic reaction theory, the Glauber model. Extending the idea of the black sphere model, we find one-to-one correspondence between the nuclear bulk structure information and proton-nucleus elastic scattering diffraction peak. This implies that we can extract both the nuclear radius and diffuseness simultaneously, using the position of the first diffraction peak and its magnitude of the elastic scattering differential cross section. We confirm the reliability of this approach by using realistic density distributions obtained by a mean-field model.

Case report. Pediatric carpal fracture dislocation.

PubMed

DeCoster, T A; Faherty, S; Morris, A L

1994-01-01

Transcarpal fractures in children are rare in the orthopaedic literature. This is a case report of a 10-year-old boy who sustained fractures across the distal radius, scaphoid, lunate, and triquetrum with gross displacement. Treatment consisted of open reduction with internal fixation of the fractures and ligamentous repair through a combined dorsal and palmar approach. The injury healed with good wrist function but abnormal carpal development. This unusual pattern of injury is described so that it may be more readily appreciated in the future.

Microsurgical reconstruction in limb salvage due to a giant cell tumor of the distal radius. Case report.

PubMed

Sánchez-Torres, L J; de la Parra-Márquez, M L; Cruz-Escalante, A M; Ramírez-Barroso, R; Espinoza-Velazco, A

2017-01-01

The giant cell tumor of bone is one of the most controversial neoplasms due to growth patterns that may present. The case reported shows a very aggressive tumor in a classic location, but key to hand function. Rather than treat with radical surgery, was planned and performed a wide resection with an ulnar-carpus arthrodesis and microsurgical reconstruction of the defect throught an anterolateral thigh flap. The multidisciplinary approach of bone neoplasms produce a positive impact on patients.

Unusual twig "twistiness" in pawpaw (Asimina triloba) provides biomechanical protection for distal foliage in high winds.

PubMed

Goodrich, Katherine R; Ortiz, Luis A; Coughlin, David J

2016-11-01

Deciduous woody species invest considerable resources in the growth of new foliage and distal stems. This new growth is at risk for mechanical damage from high winds and storms. Pawpaw has large leaves borne distally on thin twigs. Following a storm, pawpaw branches sometimes exhibit a persistent "flipped" orientation, slowly returning upright over 24 h. We investigated biomechanical properties of pawpaw twigs, comparing them to co-occurring species with similarly high leaf areas and loads, which do not exhibit this "flipping". Our goal was to determine biomechanical and structural properties in these species and how variation in form might relate to functional differences. We measured flexural stiffness, torsional stiffness, and viscoelastic creep in pawpaw and co-occurring trees Liriodendron tulipifera and Carya cordiformis. We also recorded twig/foliage reconfiguration in high winds. We stained thin cross sections of distal twigs and recorded images using fluorescent light microscopy. Flexural and torsional stiffness increased with twig radius in pawpaw and tulip tree, although torsional stiffness increased more slowly in pawpaw. Pawpaw had a high ratio of flexural to torsional stiffness (EI/GJ) across a range of twig radii and significant viscoelastic creep compared with the other species. Biomechanical data showed that pawpaw twigs were "twistier" than the comparison species, which were shown previously to alleviate drag-induced damage by reorienting petioles and leaves. Pawpaw has an unusual strategy of low torsional stiffness in twigs, allowing for reorientation of the entire distal appendage, likely minimizing drag-induced damage in storms. © 2016 Botanical Society of America.

Neurologic complications in common wrist and hand surgical procedures

PubMed Central

Verdecchia, Nicole; Johnson, Julie; Baratz, Mark; Orebaugh, Steven

2018-01-01

Nerve dysfunction after upper extremity orthopedic surgery is a recognized complication, and may result from a variety of different causes. Hand and wrist surgery require incisions and retraction that necessarily border on small peripheral nerves, which may be difficult to identify and protect with absolute certainty. This article reviews the rates and ranges of reported nerve dysfunction with respect to common surgical interventions for the distal upper extremity, including wrist arthroplasty, wrist arthrodesis, wrist arthroscopy, distal radius open reduction and internal fixation, carpal tunnel release, and thumb carpometacarpal surgery. A relatively large range of neurologic complications is reported, however many of the studies cited involve relatively small numbers of patients, and only rarely are neurologic complications included as primary outcome measures. Knowledge of these neurologic outcomes should help the surgeon to better counsel patients with regard to perioperative risk, as well as provide insight into workup and management of any adverse neurologic outcomes that may arise.

Stability of miscible core?annular flows with viscosity stratification

NASA Astrophysics Data System (ADS)

Selvam, B.; Merk, S.; Govindarajan, Rama; Meiburg, E.

The linear stability of variable viscosity, miscible core-annular flows is investigated. Consistent with pipe flow of a single fluid, the flow is stable at any Reynolds number when the magnitude of the viscosity ratio is less than a critical value. This is in contrast to the immiscible case without interfacial tension, which is unstable at any viscosity ratio. Beyond the critical value of the viscosity ratio, the flow can be unstable even when the more viscous fluid is in the core. This is in contrast to plane channel flows with finite interface thickness, which are always stabilized relative to single fluid flow when the less viscous fluid is in contact with the wall. If the more viscous fluid occupies the core, the axisymmetric mode usually dominates over the corkscrew mode. It is demonstrated that, for a less viscous core, the corkscrew mode is inviscidly unstable, whereas the axisymmetric mode is unstable for small Reynolds numbers at high Schmidt numbers. For the parameters under consideration, the switchover occurs at an intermediate Schmidt number of about 500. The occurrence of inviscid instability for the corkscrew mode is shown to be consistent with the Rayleigh criterion for pipe flows. In some parameter ranges, the miscible flow is seen to be more unstable than its immiscible counterpart, and the physical reasons for this behaviour are discussed.A detailed parametric study shows that increasing the interface thickness has a uniformly stabilizing effect. The flow is least stable when the interface between the two fluids is located at approximately 0.6 times the tube radius. Unlike for channel flow, there is no sudden change in the stability with radial location of the interface. The instability originates mainly in the less viscous fluid, close to the interface.

Knuckle-walking anteater: a convergence test of adaptation for purported knuckle-walking features of African Hominidae.

PubMed

Orr, Caley M

2005-11-01

Appeals to synapomorphic features of the wrist and hand in African apes, early hominins, and modern humans as evidence of knuckle-walking ancestry for the hominin lineage rely on accurate interpretations of those features as adaptations to knuckle-walking locomotion. Because Gorilla, Pan, and Homo share a relatively close common ancestor, the interpretation of such features is confounded somewhat by phylogeny. The study presented here examines the evolution of a similar locomotor regime in New World anteaters (order Xenarthra, family Myrmecophagidae) and uses the terrestrial giant anteater (Myrmecophaga tridactyla) as a convergence test of adaptation for purported knuckle-walking features of the Hominidae. During the stance phase of locomotion, Myrmecophaga transmits loads through flexed digits and a vertical manus, with hyperextension occurring at the metacarpophalangeal joints of the weight-bearing rays. This differs from the locomotion of smaller, arboreal anteaters of outgroup genera Tamandua and Cyclopes that employ extended wrist postures during above-branch quadrupedality. A number of features shared by Myrmecophaga and Pan and Gorilla facilitate load transmission or limit extension, thereby stabilizing the wrist and hand during knuckle-walking, and distinguish these taxa from their respective outgroups. These traits are a distally extended dorsal ridge of the distal radius, proximal expansion of the nonarticular surface of the dorsal capitate, a pronounced articular ridge on the dorsal aspects of the load-bearing metacarpal heads, and metacarpal heads that are wider dorsally than volarly. Only the proximal expansion of the nonarticular area of the dorsal capitate distinguishes knuckle-walkers from digitigrade cercopithecids, but features shared with digitigrade primates might be adaptive to the use of a vertical manus of some sort in the stance phase of terrestrial locomotion. The appearance of capitate nonarticular expansion and the dorsal ridge of the distal radius in the hominin lineage might be indicative of a knuckle-walking ancestry for bipedal hominins if interpreted within the biomechanical and phylogenetic context of hominid locomotor evolution. Copyright 2005 Wiley-Liss, Inc

Light Collection Efficiency in Thin Strip Plastic Scintillator for the Study of ISGMR in Unstable Nuclei

NASA Astrophysics Data System (ADS)

Shafer, Jacob

2011-10-01

The compressibility of nuclear matter (KA) is one of the constituent of the equation of state for nuclear matter which is important in the study Neutron Stars and Super Novae. The KA is proportional to the Giant Monopole Resonance (GMR) energy and is related by the equation EGMR = (h2/mr2) 1/2 *(AKA)1/2 , where ``m'' is the mass of a nucleon and ``r'' is the radius of the nucleus. The GMR in unstable nuclei is important because the KA is related to the ratio of protons to neutrons. For this reason, it is desirable to study unstable nuclei as well as stable nuclei. The study of the GMR in unstable nuclei will be done using inverse kinematics on a target of Lithium (6Li). A detector composed of two layers of thin strip scintillators and one layer of large block scintillators has been designed and constructed to give adequate energy and angular distribution over a large portion of the solid angle where decay particles from the ISGMR can be found. Attenuation of the light signal in the strip scintillators was measured using an Americium (241Am) alpha source. Gains in light collection efficiency due to various wrapping techniques were also measured. The thin strip scintillators are connected to the photomultiplier tube (PMT) via bundles of optical fiber. Losses in light calculation efficiency due to fiber bundles were measured as well. Funded by DOE and NSF-REU.

Baroclinic instability in the solar tachocline

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

Gilman, Peter; Dikpati, Mausumi, E-mail: gilman@ucar.edu, E-mail: dikpati@ucar.edu

2014-05-20

The solar tachocline is likely to be close to a geostrophic 'thermal wind', for which the Coriolis force associated with differential rotation is closely balanced by a latitudinal pressure gradient, leading to a tight relation between the vertical gradient of rotation and the latitudinal entropy gradient. Using a hydrostatic but nongeostrophic spherical shell model, we examine baroclinic instability of the tachocline thermal wind. We find that both the overshoot and radiative parts of the tachocline should be baroclinicly unstable at most latitudes. Growth rates are roughly five times higher in middle and high latitudes compared to low latitudes, and muchmore » higher in the overshoot than in the radiative tachocline. They range in e-folding amplification from 10 days in the high latitude overshoot tachocline, down to 20 yr for the low latitude radiative tachocline. In the radiative tachocline only, longitudinal wavenumbers m = 1, 2 are unstable, while in the overshoot tachocline a much broader range of m are unstable. At all latitudes and with all stratifications, the longitudinal scale of the most unstable mode is comparable to the Rossby deformation radius, while the growth rate is set by the local latitudinal entropy gradient. Baroclinic instability in the tachocline competing with instability of the latitude rotation gradient established in earlier studies should be important for the workings of the solar dynamo and should be expected to be found in most stars that contain an interface between radiative and convective domains.« less

Treatment of a Femur Nonunion with Microsurgical Corticoperiosteal Pedicled Flap from the Medial Femoral Condyle

PubMed Central

Guzzini, Matteo; Guidi, Marco; Civitenga, Carolina; Ferri, Germano; Ferretti, Andrea

2016-01-01

Introduction. The vascularized corticoperiosteal flap is harvested from the medial femoral condyle and it is nourished by the articular branch of the descending genicular artery and the superomedial genicular artery. This flap is usually harvested as a free flap for the reconstruction of bone defects at forearm, distal radius, carpus, hand, and recently at lower limb too. Case Report. A 50-year-old Caucasian man referred to our department for hypertrophic nonunion of the distal femur, refractory to the conservative treatments. The first surgical choice was the revision of the nail and the bone reconstruction with a corticoperiosteal pedicled flap from the medial femoral condyle. We considered union to have occurred 3.5 months after surgery when radiographs showed bridging of at least three of the four bony cortices and clinically the patient was able to walk with full weight bearing without any pain. At the last follow-up (25 months), the patient was completely satisfied with the procedure. Discussion. The corticoperiosteal flap allows a faster healing of fractures with a minimal morbidity at the donor site. We suggest that the corticoperiosteal pedicled flap graft is a reliable and effective treatment for distal femur nonunion. PMID:27064589

[Frequency of diagnosis of postmenopausal osteoporosis of the spine, distant radius and extravertebral fractures in women with normal body mass, overweight and obesity].

PubMed

Popov, A A; Izmozherova, N V; Fominykh, M I; Tagil'tseva, N V; Kozulina, E V; Gavrilova, E I

2008-01-01

To assess features and peculiarities of postmenopausal osteoporosis (OP) in women with normal body mass, overweight and obesity. Dual energy X-ray absorptiometry of the lumbal spine (Lunar DPX) and distal radius X-ray absorptiometry (DTX 200) were performed during cross-section study of 730 symptomatic postmenopausal women. OP was diagnosed in 253 (34.7%) women, 30.5% of them had normal body mass, 43.2% had overweight and 26.3% were obese. Among them 227 had atraumatic fractures at the age over 50 years. Obese OP patients had significantly higher frequency of arterial hypertension, chronic heart failure, osteoarthritis and glucose metabolism disorders than osteoporotic patients with normal body mass. Fracture frequency did not differ between groups with normal body mass, overweight and obesity. Excessive body mass did not decrease fracture risk in women with postmenopausal OP.

Bone microarchitecture in adolescent boys with autism spectrum disorder.

PubMed

Neumeyer, Ann M; Cano Sokoloff, Natalia; McDonnell, Erin; Macklin, Eric A; McDougle, Christopher J; Misra, Madhusmita

2017-04-01

Boys with autism spectrum disorder (ASD) have lower areal bone mineral density (aBMD) than typically developing controls (TDC). Studies of volumetric BMD (vBMD) and bone microarchitecture provide information about fracture risk beyond that provided by aBMD but are currently lacking in ASD. To assess ultradistal radius and distal tibia vBMD, bone microarchitecture and strength estimates in adolescent boys with ASD compared to TDC. Cross-sectional study of 34 boys (16 ASD, 18 TDC) that assessed (i) aBMD at the whole body (WB), WB less head (WBLH), hip and spine using dual X-ray absorptiometry (DXA), (ii) vBMD and bone microarchitecture at the ultradistal radius and distal tibia using high-resolution peripheral quantitative CT (HRpQCT), and (iii) bone strength estimates (stiffness and failure load) using micro-finite element analysis (FEA). We controlled for age in all groupwise comparisons of HRpQCT and FEA measures. Activity questionnaires, food records, physical exam, and fasting levels of 25(OH) vitamin D and bone markers (C-terminal collagen crosslinks and N-terminal telopeptide (CTX and NTX) for bone resorption, N-terminal propeptide of Type 1 procollagen (P1NP) for bone formation) were obtained. ASD participants were slightly younger than TDC participants (13.6 vs. 14.2years, p=0.44). Tanner stage, height Z-scores and fasting serum bone marker levels did not differ between groups. ASD participants had higher BMI Z-scores, percent body fat, IGF-1 Z-scores, and lower lean mass and aBMD Z-scores than TDC at the WB, WBLH, and femoral neck (P<0.1). At the radius, ASD participants had lower trabecular thickness (0.063 vs. 0.070mm, p=0.004), compressive stiffness (56.7 vs. 69.7kN/mm, p=0.030) and failure load (3.0 vs. 3.7kN, p=0.031) than TDC. ASD participants also had 61% smaller cortical area (6.6 vs. 16.4mm 2 , p=0.051) and thickness (0.08 vs. 0.22mm, p=0.054) compared to TDC. At the tibia, ASD participants had lower compressive stiffness (183 vs. 210kN/mm, p=0.048) and failure load (9.4 vs. 10.8kN, p=0.043) and 23% smaller cortical area (60.3 vs. 81.5mm 2 , p=0.078) compared to TDC. A lower proportion of ASD participants were categorized as "very physically active" (20% vs. 72%, p=0.005). Differences in physical activity, calcium intake and IGF-1 responsiveness may contribute to group differences in stiffness and failure load. Bone microarchitectural parameters are impaired in ASD, with reductions in bone strength estimates (stiffness and failure load) at the ultradistal radius and distal tibia. This may result from lower physical activity and calcium intake, and decreased IGF-1 responsiveness. Copyright © 2017 Elsevier Inc. All rights reserved.

Dynamics of a Sonoluminescing Bubble in Sulfuric Acid

NASA Astrophysics Data System (ADS)

Hopkins, Stephen D.; Putterman, Seth J.; Kappus, Brian A.; Suslick, Kenneth S.; Camara, Carlos G.

2005-12-01

The spectral shape and observed sonoluminescence emission from Xe bubbles in concentrated sulfuric acid is consistent only with blackbody emission from a spherical surface that fills the bubble. The interior of the observed 7000 K blackbody must be at least 4 times hotter than the emitting surface in order that the equilibrium light-matter interaction length be smaller than the radius. Bright emission is correlated with long emission times (˜10ns), sharp thresholds, unstable translational motion, and implosions that are sufficiently weak that contributions from the van der Waals hard core are small.

Dynamics of a sonoluminescing bubble in sulfuric acid.

PubMed

Hopkins, Stephen D; Putterman, Seth J; Kappus, Brian A; Suslick, Kenneth S; Camara, Carlos G

2005-12-16

The spectral shape and observed sonoluminescence emission from Xe bubbles in concentrated sulfuric acid is consistent only with blackbody emission from a spherical surface that fills the bubble. The interior of the observed 7000 K blackbody must be at least 4 times hotter than the emitting surface in order that the equilibrium light-matter interaction length be smaller than the radius. Bright emission is correlated with long emission times (approximately 10 ns), sharp thresholds, unstable translational motion, and implosions that are sufficiently weak that contributions from the van der Waals hard core are small.

Case report and review of the literature total endovascular repair of acute ascending aortic rupture: a case report and review of the literature.

PubMed

McCallum, John C; Limmer, Karl K; Perricone, Anthony; Bandyk, Dennis; Kansal, Nikhil

2013-07-01

Thoracic aortic endografting has been successfully implemented to treat aneurysmal disease of the distal aortic arch and descending thoracic aorta. Although there are reports of ascending aortic endovascular interventions, the total endovascular repair of a ruptured ascending aorta secondary to a Type A dissection has not been described. We report the case of a 77-year-old patient who presented with a ruptured ascending aortic aneurysm secondary to degeneration of a Stanford type A aortic dissection. His surgical history was significant for orthotropic heart transplant 19 years prior. The dissection, aneurysm, and rupture occurred in the native aorta distal to the ascending aortic suture line. At presentation, he was hemodynamically unstable with a right hemothorax. We placed 3 Medtronic Talent Thoracic Stent Graft devices (Medtronic Inc, Minneapolis, MN) across the suture line in the ascending aorta, excluding the rupture. The patient survived and has been followed to 25 months.

The role of total elbow arthroplasty in traumatology.

PubMed

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

2014-10-01

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

Osteoporosis and Osteopathy Markers in Patients with Mastocytosis

PubMed Central

Alpay Kanıtez, Nilüfer; Erer, Burak; Doğan, Öner; Büyükbabani, Nesimi; Baykal, Can; Sindel, Dilşad; Tanakol, Refik; Yavuz, Akif Selim

2015-01-01

Objective: Osteoporosis, osteosclerosis, and lytic bone lesions have been observed in patients with systemic mastocytosis (SM). We examined bone mineral density (BMD) biochemical turnover markers and serum tryptase levels in SM, which is considered a rare disease. Materials and Methods: Seventeen adult patients (5 females, 12 males; median age: 33 years, range: 20-64) with mastocytosis were included in this study. We investigated the value of quantitative ultrasound (QUS) of the calcaneus in the assessment of BMD in SM patients, as well as BMD of the lumbar spine (L1-L4), femoral neck, and distal radius using dual energy x-ray absorptiometry (DXA) and plasma tryptase levels, biochemical markers of bone turnover. Results: At lumbar spine L1-L4, the femoral neck, and the distal radius or as calcaneus stiffness, 12 of 17 patients had T-scores of less than -1 at least at 1 site, reflecting osteopenia. Three of 17 patients had T-scores showing osteoporosis (T-score <-2.5). There was no relationship between DXA and bone lesion severity. We also found a significant positive correlation between tryptase levels and disease severity, as well as between disease severity and pyridinoline (p<0.01 by Spearman’s test). Conclusion: DXA and calcaneal QUS may not be appropriate techniques to assess bone involvement in SM patients because of the effects of osteosclerosis. This study further shows that the osteoclastic marker pyridinoline is helpful in patients with severe disease activity and sclerotic bone lesions to show bone demineralization. PMID:25805674

[Magnetic resonance imaging for the wrist joint of the coal miners in vibration department].

PubMed

Zhao, Xuan-zhi; Liu, Rui-lian; Hu, Shu-dong; Zhang, Wei; Xu, Wen-xiu; Ge, Ling-xia

2006-04-01

To study the magnetic resonance imaging (MRI) in the wrist joint of coal miners who work in excavation and vibration department. Forty-three coal miners with the hand-arm vibration disease served as the observation group while 20 workers who were not working in the vibration department acted as the control group. The patients in the observation group were divided into five subgroups according to the time when they received vibration. The regularity of the development of signs and symptoms of MRI was observed and analyzed. The hydroarthrosis was most found in MRI. There were significant difference in hydroarthrosis (chi(2) = 8.80, P < 0.01), osteoporosis and osteomyelitis (chi(2) = 3.91, chi(2) = 5.01, P < 0.05 respectively) between the observation group and the control group. The edema of bone marrow and the avascular necrosis of ossa carpi were found only in the observation group and not found in the control group. The hydroarthrosis and the edema of bone marrow occurred most in the early stage of vibration. The signal in the edema of the bone marrow of the distal end of the radius was decreased in the GE sequence T(2)WI with the specificity. (1) Changes in the wrist joint occur in the early stage of the vibration work, and can be found in the MRI. (2) The edema of the bone marrow of the distal end of the radius is of great value in the diagnosis of the hand-arm vibration disease.

Examination of the pronator quadratus muscle during hardware removal procedures after volar plating for distal radius fractures.

PubMed

Nho, Jae-Hwi; Gong, Hyun Sik; Song, Cheol Ho; Wi, Seung Myung; Lee, Young Ho; Baek, Goo Hyun

2014-09-01

It is not clear whether the pronator quadratus (PQ) muscle actually heals and provides a meaningful pronation force after volar plating for distal radius fractures (DRFs). We aimed to determine whether the length of the PQ muscle, which is dissected and then repaired during volar plating for a DRF, affects the forearm rotation strength and clinical outcomes. We examined 41 patients who requested hardware removal after volar plating. We measured the isokinetic forearm rotation strength and clinical outcomes including grip strength, wrist range of motion, and disabilities of the arm, shoulder and hand (DASH) scores at 6 months after fracture fixation. During the hardware removal surgery, which was performed at an average of 9 months (range, 8.3 to 11.5 months) after fracture fixation, we measured the PQ muscle length. The average PQ muscle length was 68% of the normal muscle length, and no significant relationship was found between the PQ muscle length and the outcomes including isokinetic forearm rotation strength, grip strength, wrist range of motion, and DASH scores. This study demonstrates that the length of the healed PQ muscle does not affect isokinetic forearm rotation strength and clinical outcomes after volar plating for DRFs. The results of this study support our current practice of loose repair of the PQ that is performed by most of the surgeons to prevent tendon irritation over the plate, and suggest that tight repair of the PQ is not necessary for achieving improved forearm function.

Logarithmic spiral flap for circular or oval defects on the lateral surface of the nose and nasal ala: a series of 15 cases.

PubMed

Moreno-Artero, E; Redondo, P

2015-10-01

A large number of flaps, particularly rotation and transposition flaps, have been described for the closure of skin defects left by oncologic surgery of the nose. The logarithmic spiral flap is a variant of the rotation flap. We present a series of 15 patients with different types of skin tumor on the nose. The skin defect resulting from excision of the tumor by micrographic surgery was reconstructed using various forms of the logarithmic spiral flap. There are 3 essential aspects to flap design: commencement of the pedicle at the upper or lower border of the wound, a width of the distal end of the flap equal to the vertical diameter of the defect, and a progressive increase in the radius of the spiral from the distal end of the flap to its base. The cosmetic and functional results of surgical reconstruction were satisfactory, and no patient required additional treatment to improve scar appearance. The logarithmic spiral flap is useful for the closure of circular or oval defects situated on the lateral surface of the nose and nasal ala. The flap initiates at one of the borders of the wound as a pedicle with a radius that increases progressively to create a spiral. We propose the logarithmic spiral flap as an excellent option for the closure of circular or oval defects of the nose. Copyright © 2015 Elsevier España, S.L.U. and AEDV. All rights reserved.

Accelerated rehabilitation compared with a standard protocol after distal radial fractures treated with volar open reduction and internal fixation: a prospective, randomized, controlled study.

PubMed

Brehmer, Jess L; Husband, Jeffrey B

2014-10-01

There are relatively few studies in the literature that specifically evaluate accelerated rehabilitation protocols for distal radial fractures treated with open reduction and internal fixation (ORIF). The purpose of this study was to compare the early postoperative outcomes (at zero to twelve weeks postoperatively) of patients enrolled in an accelerated rehabilitation protocol with those of patients enrolled in a standard rehabilitation protocol following ORIF for a distal radial fracture. We hypothesized that patients with accelerated rehabilitation after volar ORIF for a distal radial fracture would have an earlier return to function compared with patients who followed a standard protocol. From November 2007 to November 2010, eighty-one patients with an unstable distal radial fracture were prospectively randomized to follow either an accelerated or a standard rehabilitation protocol after undergoing ORIF with a volar plate for a distal radial fracture. Both groups began with gentle active range of motion at three to five days postoperatively. At two weeks, the accelerated group initiated wrist/forearm passive range of motion and strengthening exercises, whereas the standard group initiated passive range of motion and strengthening at six weeks postoperatively. Patients were assessed at three to five days, two weeks, three weeks, four weeks, six weeks, eight weeks, twelve weeks, and six months postoperatively. Outcomes included Disabilities of the Arm, Shoulder and Hand (DASH) scores (primary outcome) and measurements of wrist flexion/extension, supination, pronation, grip strength, and palmar pinch. The patients in the accelerated group had better mobility, strength, and DASH scores at the early postoperative time points (zero to eight weeks postoperatively) compared with the patients in the standard rehabilitation group. The difference between the groups was both clinically relevant and statistically significant. Patients who follow an accelerated rehabilitation protocol that emphasizes motion immediately postoperatively and initiates strengthening at two weeks after volar ORIF of a distal radial fracture have an earlier return to function than patients who follow a more standard rehabilitation protocol. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Measurement of humerus and radius bone mineral content in the term and preterm infant

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

Vyhmeister, N.R.; Linkhart, T.A.

1988-07-01

We compared two anatomic sites for single-photon absorptiometric measurement of bone mineral content (BMC) in term and preterm infants. The distal one third of the radius and the midportion of the humerus were evaluated for measurements of BMC with an unmodified, commercially available bone densitometer. We assessed reproducibility of BMC and bone width (BW) measurements and defined normal at-birth ranges of BMC, BW, and BMC/BW ratio for infants with gestational ages of 24 to 42 weeks. Humerus BMC correlated with gestational age, birth weight, and BW of patients and did not differ from humerus BMC values determined over the samemore » range of gestational ages at another center. Representative serial measurements of two very low birth weight (VLBW) infants are presented to demonstrate the feasibility of using humerus BMC in longitudinal studies to assess changes in bone mineralization. We conclude that bone densitometer measurements of mid-humerus BMC can be successfully performed and are preferable to similar measurements of the radius for VLBW infants. Normal humerus BMC values were defined for use in diagnosis and evaluation of the efficacy of treatment in VLBW infants who are at high risk of developing osteopenia of prematurity.« less

An evanescent wave biosensor--Part I: Fluorescent signal acquisition from step-etched fiber optic probes.

PubMed

Anderson, G P; Golden, J P; Ligler, F S

1994-06-01

A fiber-optic biosensor capable of remote continuous monitoring has recently been designed. To permit sensing at locations separate from the optoelectronic instrumentation, long optical fibers are utilized. An evanescent wave immuno-probe is prepared by removing the cladding near the distal end of the fiber and covalently attaching antibodies to the core. Probes with a radius unaltered from that of the original core inefficiently returned the signal produced upon binding the fluorescent-labelled antigen. To elucidate the limiting factors in signal acquisition, a series of fibers with increasingly reduced probe core radius was examined. The results were consistent with the V-number mismatch, the difference in mode carrying capacity between the clad and unclad fiber, being a critical factor in limiting signal coupling from the fiber probe. However, it was also delineated that conditions which conserve excitation power, such that power in the evanescent wave is optimized, must also be met to obtain a maximal signal. The threshold sensitivity for the optimal step-etched fiber probe was improved by over 20-fold in an immunoassay, although, it was demonstrated that signal acquisition decreased along the probe length, suggesting that a sensor region of uniform radius is not ideal.

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

PubMed

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

2018-06-01

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

Fatigue strength of common tibial intramedullary nail distal locking screws

PubMed Central

Griffin, Lanny V; Harris, Robert M; Zubak, Joseph J

2009-01-01

Background Premature failure of either the nail and/or locking screws with unstable fracture patterns may lead to angulation, shortening, malunion, and IM nail migration. Up to thirty percent of all unreamed nail locking screws can break after initial weight bearing is allowed at 8–10 weeks if union has not occurred. The primary problem this presents is hardware removal during revision surgery. The purposes of our study was to evaluate the relative fatigue resistance of distal locking screws and bolts from representative manufacturers of tibial IM nail systems, and develop a relative risk assessment of screws and materials used. Evaluations included quantitative and qualitative measures of the relative performance of these screws. Methods Fatigue tests were conducted to simulate a comminuted fracture that was treated by IM nailing assuming that all load was carried by the screws. Each screw type was tested ten times in a single screw configuration. One screw type was tested an additional ten times in a two-screw parallel configuration. Fatigue tests were performed using a servohydraulic materials testing system and custom fixturing that simulated screws placed in the distal region of an appropriately sized tibial IM nail. Fatigue loads were estimated based on a seventy-five kilogram individual at full weight bearing. The test duration was one million cycles (roughly one year), or screw fracture, whichever occurred first. Failure analysis of a representative sample of titanium alloy and stainless steel screws included scanning electron microscopy (SEM) and quantitative metallography. Results The average fatigue life of a single screw with a diameter of 4.0 mm was 1200 cycles, which would correspond roughly to half a day of full weight bearing. Single screws with a diameter of 4.5 mm or larger have approximately a 50 percent probability of withstanding a week of weight bearing, whereas a single 5.0 mm diameter screw has greater than 90 percent probability of withstanding more than a week of weight bearing. If two small diameter screws are used, our tests showed that the probability of withstanding a week of weight bearing increases from zero to about 20 percent, which is similar to having a single 4.5 mm diameter screw providing fixation. Conclusion Our results show that selecting the system that uses the largest distal locking screws would offer the best fatigue resistance for an unstable fracture pattern subjected to full weight bearing. Furthermore, using multiple screws will substantially reduce the risk of premature hardware failure. PMID:19371438

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

NASA Astrophysics Data System (ADS)

Zhang, Yuwei; Guo, Zhansheng

2018-03-01

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

Higher-order Skyrme hair of black holes

NASA Astrophysics Data System (ADS)

Gudnason, Sven Bjarke; Nitta, Muneto

2018-05-01

Higher-order derivative terms are considered as replacement for the Skyrme term in an Einstein-Skyrme-like model in order to pinpoint which properties are necessary for a black hole to possess stable static scalar hair. We find two new models able to support stable black hole hair in the limit of the Skyrme term being turned off. They contain 8 and 12 derivatives, respectively, and are roughly the Skyrme-term squared and the so-called BPS-Skyrme-term squared. In the twelfth-order model we find that the lower branches, which are normally unstable, become stable in the limit where the Skyrme term is turned off. We check this claim with a linear stability analysis. Finally, we find for a certain range of the gravitational coupling and horizon radius, that the twelfth-order model contains 4 solutions as opposed to 2. More surprisingly, the lowest part of the would-be unstable branch turns out to be the stable one of the 4 solutions.

The effect of topography on the evolution of unstable disturbances in a baroclinic atmosphere

NASA Technical Reports Server (NTRS)

Clark, J. H. E.

1985-01-01

A two layer spectral quasi-geostrophic model is used to simulate the effects of topography on the equilibria, their stability, and the long term evolution of incipient unstable waves. The flow is forced by latitudinally dependent radiative heating. Dissipation is in the form of Rayleigh friction. An analytical solution is found for the propagating finite amplitude waves which result from baroclinic instability of the zonal winds when topography is absent. The appearance of this solution for wavelengths just longer than the Rossby radius of deformation and disappearance of ultra-long wavelengths is interpreted in terms of the Hopf bifurcation theory. Simple dynamic and thermodynamic criteria for the existence of periodic Rossby solutions are presented. A Floquet stability analysis shows that the waves are neutral. The nature of the form drag instability of high index equilibria is investigated. The proximity of the equilibrium shear to a resonant value is essential for the instability, provided the equilibrium occurs at a slightly stronger shear than resonance.

Tunneling decay of false vortices

NASA Astrophysics Data System (ADS)

Lee, Bum-Hoon; Lee, Wonwoo; MacKenzie, Richard; Paranjape, M. B.; Yajnik, U. A.; Yeom, Dong-han

2013-10-01

We consider the decay of vortices trapped in the false vacuum of a theory of scalar electrodynamics in 2+1 dimensions. The potential is inspired by models with intermediate symmetry breaking to a metastable vacuum that completely breaks a U(1) symmetry, while in the true vacuum, the symmetry is unbroken. The false vacuum is unstable through the formation of true vacuum bubbles; however, the rate of decay can be extremely long. On the other hand, the false vacuum can contain metastable vortex solutions. These vortices contain the true vacuum inside in addition to a unit of magnetic flux and the appropriate topologically nontrivial false vacuum outside. We numerically establish the existence of vortex solutions which are classically stable; however, they can decay via tunneling. In general terms, they tunnel to a configuration which is a large, thin-walled vortex configuration that is now classically unstable to the expansion of its radius. We compute an estimate for the tunneling amplitude in the semiclassical approximation. We believe our analysis would be relevant to superconducting thin films or superfluids.

Wake Numerical Simulation Based on the Park-Gauss Model and Considering Atmospheric Stability

NASA Astrophysics Data System (ADS)

Yang, Xiangsheng; Zhao, Ning; Tian, Linlin; Zhu, Jun

2016-06-01

In this paper, a new Park-Gauss model based on the assumption of the Park model and the Eddy-viscosity model is investigated to conduct the wake numerical simulation for solving a single wind turbine problem. The initial wake radius has been modified to improve the model’s numerical accuracy. Then the impact of the atmospheric stability based on the Park-Gauss model has been studied in the wake region. By the comparisons and the analyses of the test results, it turns out that the new Park-Gauss model could achieve better effects of the wind velocity simulation in the wake region. The wind velocity in the wake region recovers quickly under the unstable atmospheric condition provided the wind velocity is closest to the test result, and recovers slowly under stable atmospheric condition in case of the wind velocity is lower than the test result. Meanwhile, the wind velocity recovery falls in between the unstable and stable neutral atmospheric conditions.

A Quantitative Investigation of Entrainment and Detrainment in Numerically Simulated Convective Clouds. Pt. 2; Simulations of Cumulonimbus Clouds

NASA Technical Reports Server (NTRS)

Cohen, Charles

1998-01-01

Deep cumulonimbus clouds are simulated using a model that makes accurate diagnoses of entrainment and detrainment rates and of the properties of entrained and detrained air. Clouds generated by a variety of initial thermodynamic soundings are compared. In the simulations, updraft entrainment rates are large near and above cloud base, through the entire depth of the conditionally unstable layer. Stronger updrafts in a more unstable environment are better able to entrain relatively undisturbed environmental air, while weaker updrafts can entrain only air that has been modified by the clouds. When the maximum buoyancy is large, the updraft includes parcels with a wide range of buoyancies, while weaker clouds are more horizontally uniform. Strong downdrafts originate from levels at which updrafts detrain, and their mass flux depends on the mass flux of the updraft. The magnitude of mixing between cloud and environment, not the entrainment rate, varies inversely with the cloud radius. How much of the mixed air is entrained depends on the buoyancy.

A nondestructive, reproducible method of measuring joint reaction force at the distal radioulnar joint.

PubMed

Canham, Colin D; Schreck, Michael J; Maqsoodi, Noorullah; Doolittle, Madison; Olles, Mark; Elfar, John C

2015-06-01

To develop a nondestructive method of measuring distal radioulnar joint (DRUJ) joint reaction force (JRF) that preserves all periarticular soft tissues and more accurately reflects in vivo conditions. Eight fresh-frozen human cadaveric limbs were obtained. A threaded Steinmann pin was placed in the middle of the lateral side of the distal radius transverse to the DRUJ. A second pin was placed into the middle of the medial side of the distal ulna colinear to the distal radial pin. Specimens were mounted onto a tensile testing machine using a custom fixture. A uniaxial distracting force was applied across the DRUJ while force and displacement were simultaneously measured. Force-displacement curves were generated and a best-fit polynomial was solved to determine JRF. All force-displacement curves demonstrated an initial high slope where relatively large forces were required to distract the joint. This ended with an inflection point followed by a linear area with a low slope, where small increases in force generated larger amounts of distraction. Each sample was measured 3 times and there was high reproducibility between repeated measurements. The average baseline DRUJ JRF was 7.5 N (n = 8). This study describes a reproducible method of measuring DRUJ reaction forces that preserves all periarticular stabilizing structures. This technique of JRF measurement may also be suited for applications in the small joints of the wrist and hand. Changes in JRF can alter native joint mechanics and lead to pathology. Reliable methods of measuring these forces are important for determining how pathology and surgical interventions affect joint biomechanics. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Rotating elastic string loops in flat and black hole spacetimes: stability, cosmic censorship and the Penrose process

NASA Astrophysics Data System (ADS)

Natário, José; Queimada, Leonel; Vicente, Rodrigo

2018-04-01

We rederive the equations of motion for relativistic strings, that is, one-dimensional elastic bodies whose internal energy depends only on their stretching, and use them to study circular string loops rotating in the equatorial plane of flat and black hole spacetimes. We start by obtaining the conditions for equilibrium, and find that: (i) if the string’s longitudinal speed of sound does not exceed the speed of light then its radius when rotating in Minkowski’s spacetime is always larger than its radius when at rest; (ii) in Minkowski’s spacetime, equilibria are linearly stable for rotation speeds below a certain threshold, higher than the string’s longitudinal speed of sound, and linearly unstable for some rotation speeds above it; (iii) equilibria are always linearly unstable in Schwarzschild’s spacetime. Moreover, we study interactions of a rotating string loop with a Kerr black hole, namely in the context of the weak cosmic censorship conjecture and the Penrose process. We find that: (i) elastic string loops that satisfy the null energy condition cannot overspin extremal black holes; (ii) elastic string loops that satisfy the dominant energy condition cannot increase the maximum efficiency of the usual particle Penrose process; (iii) if the dominant energy condition (but not the weak energy condition) is violated then the efficiency can be increased. This last result hints at the interesting possibility that the dominant energy condition may underlie the well known upper bounds for the efficiencies of energy extraction processes (including, for example, superradiance).

Calculating Transition Energy Barriers and Characterizing Activation States for Steps of Fusion

PubMed Central

Ryham, Rolf J.; Klotz, Thomas S.; Yao, Lihan; Cohen, Fredric S.

2016-01-01

We use continuum mechanics to calculate an entire least energy pathway of membrane fusion, from stalk formation, to pore creation, and through fusion pore enlargement. The model assumes that each structure in the pathway is axially symmetric. The static continuum stalk structure agrees quantitatively with experimental stalk architecture. Calculations show that in a stalk, the distal monolayer is stretched and the stored stretching energy is significantly less than the tilt energy of an unstretched distal monolayer. The string method is used to determine the energy of the transition barriers that separate intermediate states and the dynamics of two bilayers as they pass through them. Hemifusion requires a small amount of energy independently of lipid composition, while direct transition from a stalk to a fusion pore without a hemifusion intermediate is highly improbable. Hemifusion diaphragm expansion is spontaneous for distal monolayers containing at least two lipid components, given sufficiently negative diaphragm spontaneous curvature. Conversely, diaphragms formed from single-component distal monolayers do not expand without the continual injection of energy. We identify a diaphragm radius, below which central pore expansion is spontaneous. For larger diaphragms, prior studies have shown that pore expansion is not axisymmetric, and here our calculations supply an upper bound for the energy of the barrier against pore formation. The major energy-requiring deformations in the steps of fusion are: widening of a hydrophobic fissure in bilayers for stalk formation, splay within the expanding hemifusion diaphragm, and fissure widening initiating pore formation in a hemifusion diaphragm. PMID:26958888

Finite-Larmor-radius effects on z-pinch stability

NASA Astrophysics Data System (ADS)

Scheffel, Jan; Faghihi, Mostafa

1989-06-01

The effect of finite Larmor radius (FLR) on the stability of m = 1 small-axial-wavelength kinks in a z-pinch with purely poloidal magnetic field is investigated. We use the incompressible FLR MHD model; a collisionless fluid model that consistently includes the relevant FLR terms due to ion gyroviscosity, Hall effect and electron diamagnetism. With FLR terms absent, the Kadomtsev criterion of ideal MHD, 2r dp/dr + m2B2/μ0 ≥ 0 predicts instability for internal modes unless the current density is singular at the centre of the pinch. The same result is obtained in the present model, with FLR terms absent. When the FLR terms are included, a normal-mode analysis of the linearized equations yields the following results. Marginally unstable (ideal) modes are stabilized by gyroviscosity. The Hall term has a damping (but not absolutely stabilizing) effect - in agreement with earlier work. On specifying a constant current and particle density equilibrium, the effect of electron diamagnetism vanishes. For a z-pinch with parameters relevant to the EXTRAP experiment, the m = 1 modes are then fully stabilized over the crosssection for wavelengths λ/a ≤ 1, where a denotes the pinch radius. As a general z-pinch result a critical line-density limit Nmax = 5 × 1018 m-1 is found, above which gyroviscous stabilization near the plasma boundary becomes insufficient. This limit corresponds to about five Larmor radii along the pinch radius. The result holds for wavelengths close to, or smaller than, the pinch radius and for realistic equilibrium profiles. This limit is far below the required limit for a reactor with contained alpha particles, which is in excess of 1020 m-1.

STANDING SHOCK INSTABILITY IN ADVECTION-DOMINATED ACCRETION FLOWS

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

Le, Truong; Wood, Kent S.; Wolff, Michael T.

2016-03-10

Depending on the values of the energy and angular momentum per unit mass in the gas supplied at large radii, inviscid advection-dominated accretion flows can display velocity profiles with either preshock deceleration or preshock acceleration. Nakayama has shown that these two types of flow configurations are expected to have different stability properties. By employing the Chevalier and Imamura linearization method and the Nakayama instability boundary conditions, we discover that there are regions of parameter space where disks/shocks with outflows can be stable or unstable. In regions of instability, we find that preshock deceleration is always unstable to the zeroth mode withmore » zero frequency of oscillation, but is always stable to the fundamental mode and overtones. Furthermore, we also find that preshock acceleration is always unstable to the zeroth mode and that the fundamental mode and overtones become increasingly less stable as the shock location moves away from the horizon when the disk half-height expands above ∼12 gravitational radii at the shock radius. In regions of stability, we demonstrate the zeroth mode to be stable for the velocity profiles that exhibit preshock acceleration and deceleration. Moreover, for models that are linearly unstable, our model suggests the possible existence of quasi-periodic oscillations (QPOs) with ratios 2:3 and 3:5. These ratios are believed to occur in stellar and supermassive black hole candidates, for example, in GRS 1915+105 and Sgr A*, respectively. We expect that similar QPO ratios also exist in regions of stable shocks.« less

Biologic plating of unstable distal radial fractures.

PubMed

Kwak, Jae-Man; Jung, Gu-Hee

2018-04-14

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

Distinct molecular and cellular contributions to stabilizing selectin-mediated rolling under flow

PubMed Central

Yago, Tadayuki; Leppänen, Anne; Qiu, Haiying; Marcus, Warren D.; Nollert, Matthias U.; Zhu, Cheng; Cummings, Richard D.; McEver, Rodger P.

2002-01-01

Leukocytes roll on selectins at nearly constant velocities over a wide range of wall shear stresses. Ligand-coupled microspheres roll faster on selectins and detach quickly as wall shear stress is increased. To examine whether the superior performance of leukocytes reflects molecular features of native ligands or cellular properties that favor selectin-mediated rolling, we coupled structurally defined selectin ligands to microspheres or K562 cells and compared their rolling on P-selectin. Microspheres bearing soluble P-selectin glycoprotein ligand (sPSGL)-1 or 2-glycosulfopeptide (GSP)-6, a GSP modeled after the NH2-terminal P-selectin–binding region of PSGL-1, rolled equivalently but unstably on P-selectin. K562 cells displaying randomly coupled 2-GSP-6 also rolled unstably. In contrast, K562 cells bearing randomly coupled sPSGL-1 or 2-GSP-6 targeted to a membrane-distal region of the presumed glycocalyx rolled more like leukocytes: rolling steps were more uniform and shear resistant, and rolling velocities tended to plateau as wall shear stress was increased. K562 cells treated with paraformaldehyde or methyl-β-cyclodextrin before ligand coupling were less deformable and rolled unstably like microspheres. Cells treated with cytochalasin D were more deformable, further resisted detachment, and rolled slowly despite increases in wall shear stress. Thus, stable, shear-resistant rolling requires cellular properties that optimize selectin–ligand interactions. PMID:12177042

Effect of Tendon Vibration on Hemiparetic Arm Stability in Unstable Workspaces.

PubMed

Conrad, Megan O; Gadhoke, Bani; Scheidt, Robert A; Schmit, Brian D

2015-01-01

Sensory stimulation of wrist musculature can enhance stability in the proximal arm and may be a useful therapy aimed at improving arm control post-stroke. Specifically, our prior research indicates tendon vibration can enhance stability during point-to-point arm movements and in tracking tasks. The goal of the present study was to investigate the influence of forearm tendon vibration on endpoint stability, measured at the hand, immediately following forward arm movements in an unstable environment. Both proximal and distal workspaces were tested. Ten hemiparetic stroke subjects and 5 healthy controls made forward arm movements while grasping the handle of a two-joint robotic arm. At the end of each movement, the robot applied destabilizing forces. During some trials, 70 Hz vibration was applied to the forearm flexor muscle tendons. 70 Hz was used as the stimulus frequency as it lies within the range of optimal frequencies that activate the muscle spindles at the highest response rate. Endpoint position, velocity, muscle activity and grip force data were compared before, during and after vibration. Stability at the endpoint was quantified as the magnitude of oscillation about the target position, calculated from the power of the tangential velocity data. Prior to vibration, subjects produced unstable, oscillating hand movements about the target location due to the applied force field. Stability increased during vibration, as evidenced by decreased oscillation in hand tangential velocity.

Effect of Tendon Vibration on Hemiparetic Arm Stability in Unstable Workspaces

PubMed Central

Conrad, Megan O.; Gadhoke, Bani; Scheidt, Robert A.; Schmit, Brian D.

2015-01-01

Sensory stimulation of wrist musculature can enhance stability in the proximal arm and may be a useful therapy aimed at improving arm control post-stroke. Specifically, our prior research indicates tendon vibration can enhance stability during point-to-point arm movements and in tracking tasks. The goal of the present study was to investigate the influence of forearm tendon vibration on endpoint stability, measured at the hand, immediately following forward arm movements in an unstable environment. Both proximal and distal workspaces were tested. Ten hemiparetic stroke subjects and 5 healthy controls made forward arm movements while grasping the handle of a two-joint robotic arm. At the end of each movement, the robot applied destabilizing forces. During some trials, 70 Hz vibration was applied to the forearm flexor muscle tendons. 70 Hz was used as the stimulus frequency as it lies within the range of optimal frequencies that activate the muscle spindles at the highest response rate. Endpoint position, velocity, muscle activity and grip force data were compared before, during and after vibration. Stability at the endpoint was quantified as the magnitude of oscillation about the target position, calculated from the power of the tangential velocity data. Prior to vibration, subjects produced unstable, oscillating hand movements about the target location due to the applied force field. Stability increased during vibration, as evidenced by decreased oscillation in hand tangential velocity. PMID:26633892

Tidal interactions of inspiraling compact binaries

NASA Technical Reports Server (NTRS)

Bildsten, Lars; Cutler, Curt

1992-01-01

We discuss the tidal interaction in neutron star-neutron star and neutron star-black hole binaries and argue that they will not be tidally locked during the gravitational inspiral. More specifically, we show that, for inspiraling neutron stars of mass greater than about 1.2 solar mass, the shortest possible tidal synchronization time exceeds the gravitational decay time, so that the neutron star cannot be tidally locked prior to tidal disruption, regardless of its internal viscosity. For smaller mass neutron stars, an implausibly large kinematic viscosity - nearly the speed of light times the stellar radius - is required for tidal locking. We also argue that the mass transfer which occurs when the neutron star reaches the tidal radius will be unstable in neutron star-black hole binaries, and the instability will destroy the neutron star in a few orbital periods. The implications of our work for the detection of these sources by LIGO and other gravitational wave observatories and for the gamma-ray burst scenarios of Paczynski (1986, 1991) are discussed.

The Effects of Gravitational Instabilities on Gas Giant Planet Migration in Protoplanetary Disks

NASA Astrophysics Data System (ADS)

Michael, Scott A.; Durisen, R. H.

2010-05-01

In this paper we conduct several three-dimensional radiative hydrodynamic simulations to explore the effect of the inclusion of gas giant planets in gravitationally unstable protoplanetary disks. We compare several simulations carried out with the CHYMERA code including: a baseline simulation without a planet, and three simulations including planets of various masses 0.3, 1 and 3 Jupiter masses. The planets are inserted into the baseline simulation after the gravitational instabilities (GIs) have grown to non-linear amplitude. The planets are inserted at the same radius, which coincides with the co-rotation radius of the dominant global mode in the baseline simulation. We examine the effect that the GIs have on migration rates as well as the potential of halting inward migration. We also examine the effect the insertion of the planet has on the global torques caused by the GIs. Furthermore, we explore the relationship between planet mass and migration rates and effect on GIs.

Relay NBS Graft with the Plus Delivery System to Improve Deployment in Aortic Arch with Small Radius Curve

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

Ferro, Carlo; Rossi, Umberto G., E-mail: urossi76@hotmail.com; Seitun, Sara

The purpose of this report is to describe deployment of the Relay NBS Thoracic Stent Graft with the Plus Delivery System (Bolton Medical, Sunrise, FL) in a flexible resin arch model with a 15-mm radius curve as well as our preliminary clinical results. The Relay NBS graft with the Plus Delivery System was evaluated by way of bench testing, which was performed with stent grafts with diameters ranging from 24 to 46 mm and lengths ranging from 100 to 250 mm in flexible resin arch models with a 15-mm arch radius of curvature. The deployment sequence was analyzed. The Relaymore » NBS graft with the Plus Delivery System was deployed in two patients, respectively, having a 6.5-cm penetrating aortic ulcer of the proximal third of the descending thoracic aorta and a DeBakey type-I aortic dissection with chronic false lumen dilatation after surgery due to an entry site at the distal thoracic aorta. Bench tests showed proper conformation and apposition of the Relay NBS graft with the Plus Delivery System in the flexible resin model. This stent graft was deployed successfully into the two patients with a correct orientation of the first stent and without early or late complications. The Relay NBS graft with the Plus Delivery System ensures an optimal conformation and apposition of the first stent in the aortic arch with a small radius of curvature.« less

Hox11 genes regulate postnatal longitudinal bone growth and growth plate proliferation.

PubMed

Pineault, Kyriel M; Swinehart, Ilea T; Garthus, Kayla N; Ho, Edward; Yao, Qing; Schipani, Ernestina; Kozloff, Kenneth M; Wellik, Deneen M

2015-10-23

Hox genes are critical regulators of skeletal development and Hox9-13 paralogs, specifically, are necessary for appendicular development along the proximal to distal axis. Loss of function of both Hoxa11 and Hoxd11 results in severe malformation of the forelimb zeugopod. In the radius and ulna of these mutants, chondrocyte development is perturbed, growth plates are not established, and skeletal growth and maturation fails. In compound mutants in which one of the four Hox11 alleles remains wild-type, establishment of a growth plate is preserved and embryos develop normally through newborn stages, however, skeletal phenotypes become evident postnatally. During postnatal development, the radial and ulnar growth rate slows compared to wild-type controls and terminal bone length is reduced. Growth plate height is decreased in mutants and premature growth plate senescence occurs along with abnormally high levels of chondrocyte proliferation in the reserve and proliferative zones. Compound mutants additionally develop an abnormal curvature of the radius, which causes significant distortion of the carpal elements. The progressive bowing of the radius appears to result from physical constraint caused by the disproportionately slower growth of the ulna than the radius. Collectively, these data are consistent with premature depletion of forelimb zeugopod progenitor cells in the growth plate of Hox11 compound mutants, and demonstrate a continued function for Hox genes in postnatal bone growth and patterning. © 2015. Published by The Company of Biologists Ltd.

On the Stability of Strange Dwarf Hybrid Stars

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

Alford, Mark G.; Harris, Steven P.; Sachdeva, Pratik S., E-mail: harrissp@wustl.edu

2017-10-01

We investigate the stability of “strange dwarfs”: white-dwarf-sized stars with a density discontinuity between a small dense core of quark matter and a thick low-density mantle of degenerate electrons. Previous work on strange dwarfs suggested that such a discontinuity could stabilize stars that would have been classified as unstable by the conventional criteria based on extrema in the mass–radius relation. We investigate the stability of such stars by numerically solving the Sturm–Liouville equations for the lowest-energy modes of the star. We find that the conventional criteria are correct, and strange dwarfs are not stable.

Ergonomic task reduction prevents bone osteopenia in a rat model of upper extremity overuse

PubMed Central

BARBE, Mary F.; JAIN, Nisha X.; MASSICOTTE, Vicky S.; POPOFF, Steven N.; BARR-GILLESPIE, Ann E.

2015-01-01

We evaluated the effectiveness of ergonomic workload reduction of switching rats from a high repetition high force (HRHF) lever pulling task to a reduced force and reach rate task for preventing task-induced osteopenic changes in distal forelimb bones. Distal radius and ulna trabecular structure was examined in young adult rats performing one of three handle-pulling tasks for 12 wk: 1) HRHF, 2) low repetition low force (LRLF); or 3) HRHF for 4 wk and than LRLF thereafter (HRHF-to-LRLF). Results were compared to age-matched controls rats. Distal forelimb bones of 12-wk HRHF rats showed increased trabecular resorption and decreased volume, as control rats. HRHF-to-LRLF rats had similar trabecular bone quality as control rats; and decreased bone resorption (decreased trabecular bone volume and serum CTX1), increased bone formation (increased mineral apposition, bone formation rate, and serum osteocalcin), and decreased osteoclasts and inflammatory cytokines, than HRHF rats. Thus, an ergonomic intervention of HRHF-to-LRLF prevented loss of trabecular bone volume occurring with prolonged performance of a repetitive upper extremity task. These findings support the idea of reduced workload as an effective approach to management of work-related musculoskeletal disorders, and begin to define reach rate and load level boundaries for such interventions. PMID:25739896

Reliability and validity of selected measures associated with increased fall risk in females over the age of 45 years with distal radius fracture - A pilot study.

PubMed

Mehta, Saurabh P; MacDermid, Joy C; Richardson, Julie; MacIntyre, Norma J; Grewal, Ruby

2015-01-01

Clinical measurement. This study examined test-retest reliability and convergent/divergent construct validity of selected tests and measures that assess balance impairment, fear of falling (FOF), impaired physical activity (PA), and lower extremity muscle strength (LEMS) in females >45 years of age after the distal radius fracture (DRF) population. Twenty one female participants with DRF were assessed on two occasions. Timed Up and Go, Functional Reach, and One Leg Standing tests assessed balance impairment. Shortened Falls Efficacy Scale, Activity-specific Balance Confidence scale, and Fall Risk Perception Questionnaire assessed FOF. International Physical Activity Questionnaire and Rapid Assessment of Physical Activity were administered to assess PA level. Chair stand test and isometric muscle strength testing for hip and knee assessed LEMS. Intraclass correlation coefficients (ICC) examined the test-retest reliability of the measures. Pearson correlation coefficients (r) examined concurrent relationships between the measures. The results demonstrated fair to excellent test-retest reliability (ICC between 0.50 and 0.96) and low to moderate concordance between the measures (low if r ≤ 0.4; moderate if r = 0.4-0.7). The results provide preliminary estimates of test-retest reliability and convergent/divergent construct validity of selected measures associated with increased risk for falling in the females >45 years of age after DRF. Further research directions to advance knowledge regarding fall risk assessment in DRF population have been identified. Copyright © 2015 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Morphology of distal radius curvatures: a CT-based study on the Malaysian Malay population

PubMed Central

Singh, Taran Singh Pall; Sadagatullah, Abdul Nawfar; Yusof, Abdul Halim

2015-01-01

INTRODUCTION The purpose of this study was to examine the differing curves of the volar distal radius of healthy Malaysian Malays, so as to obtain detailed morphological information that will further the understanding of volar plate osteosynthesis in Malaysian Malays. METHODS Computed tomography with three-dimensional reconstruction was performed on the wrists of 16 healthy Malaysian Malay volunteers. Profile measurements were made using a software program. A novel parameter, the pronator quadratus curve angle, was explored and introduced in this study. Interclass correlation coefficients were calculated to assess the level of agreement between the data collected by the principal investigator and that collected by an independent radiologist. RESULTS The mean ± standard deviation of the arc radii on the radial aspect was 17.50° ± 5.40°, while the median (interquartile range [IQR]) of the arc radii on the ulnar aspect was 25.27° (IQR 5.80°). The mean ± standard deviation of the curvature of the pronator quadratus line was 40.52° ± 2.48°. The arc radii on the radial aspect was significantly lower than the arc radii on the ulnar aspect (p = 0.001). Different radial and ulnar arcs were observed in 56.25% of the radii; the arc was deeper on the ulnar aspect in 93.75% of the radii. CONCLUSION Based on the findings of this study, the likelihood of achieving anatomical reduction with uniformly curved, fixed-angle volar plates is questionable. Changes in the design of these implants may be needed to optimise their usage in the Malaysian Malay population. PMID:25814075

Post-osteomyelitic-acquired radial club hand deformity in children treated by centralization of ulna.

PubMed

Meena, Dinesh Kumar

2017-01-01

Radial club hand deformity acquired post haematogenous osteomyelitis of radius bone is a very rare disease. Resulting in functional and cosmetic deficit of upper limb which is similar to congenital cases. For a long-time various surgeons attempted to reconstruct the deformity by bone grafting, plating, Ilizarov, monorail external fixator, callus distraction and so on. Keeping in mind that creating single bone forearm we proposed centralization of ulna on wrist to correct the deformity. In our institute, we conducted a rare study involving small number of patients ( n = 5), between February 2013 and November 2106. The study participants comprised four male children and one female child whose average age was 1.8 months. Participant inclusion criteria were no active infection, no distal end of radius (cartilage remnant) and only haematogenous osteomyelitis. Exclusion criteria were congenital radial club hand and active infection. Decrease in the angle of radial deviation (radiologically) preoperatively from 54° to 5° and angle of volar flexion from 34° to 4° were measured. Preoperatively no ulnar angulations were observed. Length of ulna remains similar to the opposite side. No neurovascular complication noted and full range of movement regained. Our case series is unique in terms of massive bone loss, that is, distal metaphysic and epiphysis, so we followed the statement of Ono et al. and did centralization of ulna over carpus and achieved good functional and cosmetic outcome at the cost of loss of motion at the wrist, concluding that treatment is primarily considered as salvage only.

External fixation is more suitable for intra-articular fractures of the distal radius in elderly patients

PubMed Central

Ma, Chuang; Deng, Qiang; Pu, Hongwei; Cheng, Xinchun; Kan, Yuhua; Yang, Jing; Yusufu, Aihemaitijiang; Cao, Li

2016-01-01

The purpose of this study was to compare the functional outcomes, psychological impact, and complication rates associated with external fixation and volar or dorsal plating in relation to the functional parameters following treatment of intra-articular fractures of the distal radius (IFDR) in patients older than 65 years. We hypothesized that using volar or dorsal plating would improve functional outcomes, but that it would be associated with more complications and equivalent functional outcomes when compared with the external fixation group. A total of 123 consecutive patients suffering from IFDR were recruited into the study. The patients were measured for clinical, radiological, and psychosocial functioning outcomes and were followed up after 1 week and 3, 6 and 12 months. After 3 months, the plating group had better pronation (P=0.001), supination, (P=0.047) and extension (P=0.043) scores. These differences were somewhat attenuated by 6 months and disappeared at 1 year. The plating group had a greater occurrence of wound infection (P=0.043), tendonitis, (P=0.024) and additional surgery compared with the external fixation group. The only TNO-AZL Adult Quality of Life scores in the plating group that were lower than those in the external fixation group were in the “gross motor” category (walking upstairs, bending over, walking 500 yards; P=0.023). Internal fixation was more advantageous than external fixation in the early rehabilitation period; after 1 year the outcomes were similar. The plating group showed significantly higher levels of wound infection and tendonitis and had a greater need for additional surgeries. PMID:27408765

Quantification of pronator quadratus contribution to isometric pronation torque of the forearm.

PubMed

McConkey, Mark O; Schwab, Timothy D; Travlos, Andrew; Oxland, Thomas R; Goetz, Thomas

2009-11-01

The contribution of the pronator quadratus (PQ) muscle in generation of pronation torque has not been determined. The purpose of this study was to investigate pronation torque in healthy volunteers before and after temporary paralysis of the PQ with lidocaine, under electromyographic guidance. A custom apparatus was designed to allow isometric testing of pronation torque at 5 positions of rotation: 90 degrees of supination, 45 degrees of supination, neutral, 45 degrees of pronation, and 80 degrees of pronation. After validation of the apparatus, 17 (9 male, 8 female) right-hand-dominant volunteers were recruited. They were tested at all 5 positions in random order and then had their PQ muscles paralyzed with lidocaine. Repeat testing was performed in the same random order 30 minutes after injection. Three unblinded subjects underwent testing after injection of saline instead of lidocaine to determine effect of fluid volume alone on PQ function. The validation trial demonstrated reproducibility of the testing apparatus. After paralysis of PQ with lidocaine, pronation torque decreased by an average 21% (range, 16.7% to 23.2%) at all positions compared with preinjection testing. All were statistically significant except at 80 degrees of pronation. The subjects who underwent injection of saline showed no evidence of decrease in pronation torque. This study demonstrated a significant decrease in pronation torque with controlled elimination of PQ function. Open reduction and internal fixation of distal radius fractures damages the PQ and may result in a pronation torque deficit. Pronation torque measurement may help in postoperative outcome analysis of surgical procedures using the volar approach to the distal radius.

The impact of orthopaedic injuries sustained at an urban public ice skating rink: is it really free?

PubMed

Schwarzkopf, Ran; Nacke, Elliot A; Tejwani, Nirmal C

2014-01-01

Previous reports in the literature from Europe and Asia cite an increased burden on the local emergency departments and orthopaedic services during the operational period of the ice skating rinks. This retrospective observational study was undertaken in order to report the incidence, characteristic, and severity of injuries during a full season at a large urban ice skating rink, as well as to quantify the added burden the ice skating rink places on the local emergency department and the orthopaedic service. All patients seen at our emergency room who sustained an injury at the neighboring "free" ice rink were identified over the 4-month period when it was open. The data collected included type of injury, demographics, and need for surgical treatment. Over this period, 118 patients were seen in our ED (of the 135 referrals from the ice rink logbook); Of these, 43 (38%) required an orthopaedic consult and were evenly divided into upper (22) and lower extremity injuries (21). Sixty-seven percent of the patients were adults, and the most common fractures were ankle and distal radius fractures. There were two open fractures of the distal radius seen in the older patients (both in patients > 50). Overall 32% of patients needed operative treatment. Of the non-orthopaedic injuries, the most common was head injury (25%). An ice-rink may be "free" but adds significant burden to the healthcare system, and these costs should be factored in by both the sponsoring body and the healthcare system for treatment of these additional patients.

Effects of nanoparticle heating on the structure of a concentrated aqueous salt solution.

PubMed

Sindt, Julien O; Alexander, Andrew J; Camp, Philip J

2017-12-07

The effects of a rapidly heated nanoparticle on the structure of a concentrated aqueous salt solution are studied using molecular dynamics simulations. A diamond-like nanoparticle of radius 20 Å is immersed in a sodium-chloride solution at 20% above the experimental saturation concentration and equilibrated at T = 293 K and P = 1 atm. The nanoparticle is then rapidly heated to several thousand degrees Kelvin, and the system is held under isobaric-isoenthalpic conditions. It is observed that after 2-3 ns, the salt ions are depleted far more than water molecules from a proximal zone 15-25 Å from the nanoparticle surface. This leads to a transient reduction in molality in the proximal zone and an increase in ion clustering in the distal zone. At longer times, ions begin to diffuse back into the proximal zone. It is speculated that the formation of proximal and distal zones, and the increase in ion clustering, plays a role in the mechanism of nonphotochemical laser-induced nucleation.

Effects of nanoparticle heating on the structure of a concentrated aqueous salt solution

NASA Astrophysics Data System (ADS)

Sindt, Julien O.; Alexander, Andrew J.; Camp, Philip J.

2017-12-01

The effects of a rapidly heated nanoparticle on the structure of a concentrated aqueous salt solution are studied using molecular dynamics simulations. A diamond-like nanoparticle of radius 20 Å is immersed in a sodium-chloride solution at 20% above the experimental saturation concentration and equilibrated at T = 293 K and P = 1 atm. The nanoparticle is then rapidly heated to several thousand degrees Kelvin, and the system is held under isobaric-isoenthalpic conditions. It is observed that after 2-3 ns, the salt ions are depleted far more than water molecules from a proximal zone 15-25 Å from the nanoparticle surface. This leads to a transient reduction in molality in the proximal zone and an increase in ion clustering in the distal zone. At longer times, ions begin to diffuse back into the proximal zone. It is speculated that the formation of proximal and distal zones, and the increase in ion clustering, plays a role in the mechanism of nonphotochemical laser-induced nucleation.

Fueling nuclear activity in disk galaxies: Starbursts and monsters

NASA Astrophysics Data System (ADS)

Heller, Clayton H.; Shlosman, Isaac

1994-03-01

We study the evolution of the gas distribution in a globally unstable galactic disk with a particular emphasis on the gasdynamics in the central kiloparsec and the fueling activity there. The two-component self-gravitating disk is embedded in a responsive halo of comparable mass. The gas and stars are evolved using a three-dimensional hybrid smoothed particle hydrodynamics/N-body code and the gravitational interactions are calculated using a hierarchical TREE algorithm. A massive 'star formation' is introduced when the gas becomes Jeans unstable and locally exceeds the critical density of approximately 100 solar mass pc-3. The newly formed OB stars deposit energy in the gas by means of radiation-driven winds and supernovae. This energy is partially thermalized (efficiency of a few percent); the rest is radiated away. Models without star formation are evolved for a comparison. The effect of a massive object at the disk center is studied by placing a 'seed' black hole (BH) of 5 x 107 solar mass with an accretion radius of 20 pc. The tendency of the system to form a massive object 'spontaneously' is tested in models without the BH. We find that for models without star formation the bar- or dynamical friction-driven inflows lead to (1) domination of the central kpc by a few massive clouds that evolve into a single object probably via a cloud binary system, with and without a 'seed' BH, (2) accretion onto the BH which has a sporadic character, and (3) formation of remnant disks around the BH with a radius of 60-80 pc which result from the capture and digestion of clouds. For models with star formation, we find that (1) the enrgy input into the gas induces angular momentum loss and inflow rates by a factor less than 3, (2) the star formation is concentrated mainly at the apocenters of the gaseous circulation in the stellar bar and in the nuclear region, (3) the nuclear starburst phase appears to be very luminous approximately 1045-1046 erg/s and episodic with a typical single burst duration of aproximately 107 yr, and (4) the starburst phase coincides with both the gas becoming dynamically important and the catastrophic growth of the BH. It ends with the formation of cold residual less than 1 kpc radius gas disks. Models without the 'seed' BH form less than 1 kpc radius fat disks which dominate the dynamics. Gaseous bars follow, drive further inflow, and may fission into a massive cloud binary system at the center.

Site-directed mutagenesis of the conserved Asp-443 and Asp-498 carboxy-terminal residues of HIV-1 reverse transcriptase.

PubMed Central

Mizrahi, V; Usdin, M T; Harington, A; Dudding, L R

1990-01-01

Substitution of the conserved Asp-443 residue of HIV-1 reverse transcriptase by asparagine specifically suppressed the ribonuclease H activity of the enzyme without affecting the reverse transcriptase activity, suggesting involvement of this ionizable residue at the ribonuclease H active site. An analogous asparagine substitution of the Asp-498 residue yielded an unstable enzyme that was difficult to enzymatically characterize. However, the instability caused by the Asn-498 mutation was relieved by the introduction of a second distal Asn-443 substitution, yielding an enzyme with wild type reverse transcriptase activity, but lacking ribonuclease H activity. Images PMID:1699202

High-resolution simulations of unstable cylindrical gravity currents undergoing wandering and splitting motions in a rotating system

NASA Astrophysics Data System (ADS)

Dai, Albert; Wu, Ching-Sen

2018-02-01

High-resolution simulations of unstable cylindrical gravity currents when wandering and splitting motions occur in a rotating system are reported. In this study, our attention is focused on the situation of unstable rotating cylindrical gravity currents when the ratio of Coriolis to inertia forces is larger, namely, 0.5 ≤ C ≤ 2.0, in comparison to the stable ones when C ≤ 0.3 as investigated previously by the authors. The simulations reproduce the major features of the unstable rotating cylindrical gravity currents observed in the laboratory, i.e., vortex-wandering or vortex-splitting following the contraction-relaxation motion, and good agreement is found when compared with the experimental results on the outrush radius of the advancing front and on the number of bulges. Furthermore, the simulations provide energy budget information which could not be attained in the laboratory. After the heavy fluid is released, the heavy fluid collapses and a contraction-relaxation motion is at work for approximately 2-3 revolutions of the system. During the contraction-relaxation motion of the heavy fluid, the unstable rotating cylindrical gravity currents behave similar to the stable ones. Towards the end of the contraction-relaxation motion, the dissipation rate in the system reaches a local minimum and a quasi-geostrophic equilibrium state is reached. After the quasi-geostrophic equilibrium state, vortex-wandering or vortex-splitting may occur depending on the ratio of Coriolis to inertia forces. The vortex-splitting process begins with non-axisymmetric bulges and, as the bulges grow, the kinetic energy increases at the expense of decreasing potential energy in the system. The completion of vortex-splitting is accompanied by a local maximum of dissipation rate and a local maximum of kinetic energy in the system. A striking feature of the unstable rotating cylindrical gravity currents is the persistent upwelling and downwelling motions, which are observed for both the vortex-wandering and vortex-splitting motions and were not previously documented for such flows. Depending on the Reynolds number, the bulges around the circumference of the unstable rotating cylindrical gravity currents may or may not develop into cutoff distinct circulations. The number of bulges is seen to be dependent on the ratio of Coriolis to inertia forces but independent of the Reynolds number for the range of Reynolds number considered in this study.

[Anatomo-functional consideration of an aponeurosis on the caudal radiocarpus in the tiger, lion and domestic cat (Panthera tigris, Panthera leo and Felis catus)].

PubMed

Graziotti, G H; Victorica, C L

1997-09-01

This study describes a strong aponeurosis on the caudal surface of the antebrachium, between the Mm. Flexoris and the M. pronator quadratus. This aponeurosis has not been experimentally validated. By dissection and macroscopic examination of formaldehyde-prepared material, and experimental surgical transection of the structure in F. catus, the aponeurosis is described and its functional capacity is determined. The origin of the aponeurosis is the Facies caudalis, Margo medialis of the Radius and distal Ulna and inserts on the Crista transversa of the Radius and the Ligg. radiocarpeum palmare and ulno-carpeum palmare, and a strong Pars radialis. Its disposition is similar to that of the supernumerary M. anterior radialis brevis in humans. Surgical transection of the aponeurosis in F. catus resulted in hyperextension of the Manus and a decrease in the Carpus in its weight-bearing ability. These findings indicate the anatomico-functional importance of the aponeurosis in providing support to the claws.

Gymnastics participation is associated with skeletal benefits in the distal forearm: a 6-month study using peripheral Quantitative Computed Tomography.

PubMed

Burt, L A; Ducher, G; Naughton, G A; Courteix, D; Greene, D A

2013-12-01

Musculoskeletal development of the upper limbs during exposure to weight-bearing loading is under-researched during early pubescent growth. The purpose was to assess the changes in upper body musculoskeletal strength in young girls following 6 months of non-elite gymnastics participation. Eighty-four girls, 6-12 years were divided into groups based on gymnastics participation: high-training (HGYM, 6-16 hr/wk), low-training (LGYM, 1-5 hr/wk), and non-gymnasts (NONGYM). Volumetric BMD, bone geometry, estimated bone strength and muscle size were assessed at the non-dominant forearm (4% and 66% radius and ulna) with pQCT. DXA assessed aBMD and body composition. Tests for explosive power, muscle strength, and endurance were also performed. Interaction effects were observed in all variables at the 4% radius. At the 66% ulna, HGYM and LGYM had greater bone mass, size and bone strength than NONGYM, furthermore a dose-response relationship was observed at this location. Body composition was better for HGYM than LGYM and NONGYM, however muscle function was better for HGYM and LGYM than NONGYM. The greatest changes were obtained with more than one gymnastics class per week. Separating gymnastics participation-related changes from those associated with normal growth and development remains difficult, particularly at the 4% radius.

Ion velocity analysis of rotating structures in a magnetic linear plasma device

NASA Astrophysics Data System (ADS)

Claire, N.; Escarguel, A.; Rebont, C.; Doveil, F.

2018-06-01

The MISTRAL device is designed to produce a linear magnetized plasma column. It has been used a few years ago to study a nonlinear low frequency instability exhibiting an azimuthal number m = 2. By changing the experimental configuration of MISTRAL, this work shows experimental results on an m = 1 rotating instability with strongly different behavior. The spatio-temporal evolution of the ion velocity distribution function given by a laser-induced fluorescence diagnostic is measured to infer the radial and azimuthal velocities, ion fluxes, and electric fields. The naive image of a plasma exhibiting a global rotation is again invalidated in this m = 1 mode but in a different way. Contrary to the m = 2 mode, the rotation frequency of the instability is lower than the ion cyclotron frequency and ions exhibit a complex behavior with a radial outward flux inside the unstable arm and azimuthal ion fluxes always directed toward the unstable arm. The azimuthal ion velocity is close to zero inside the ionization region, whereas the radial ion velocity grows linearly with radius. The radial electric field is oriented inward inside the unstable arm and outward outside. An axial velocity perturbation is also present, indicating that contrary to the m = 2 mode, the m = 1 mode is not a flute mode. These results cannot be easily interpreted with existing theories.

The transverse force experienced by the radial head during axial loading of the forearm: A cadaveric study.

PubMed

Orbay, Jorge L; Mijares, Michael R; Berriz, Cecilia G

2016-01-01

When designing a radial head replacement, the magnitude and direction of forces applied across the proximal radio-ulnar joint (PRUJ) and the radiocapitellar joint must be included. These designs often focus on axial loads transmitted to the radial head by the capitellum; however, the radial head also bears a significant transverse force at the PRUJ. Load transmission by the central band of the interosseous ligament induces a force component in a lateral direction perpendicular to the axis of the limb, which is borne by the articular surfaces of the proximal and distal radio-ulnar joints. The objective of this study is to establish the relationship between distally applied axial forces and proximal transverse reaction forces. Five cadaveric, human forearms with intact interosseous membranes were used to measure the magnitude of transversely-directed forces experienced by the radial head during axial loading of the forearm at the lunate fossa. A Mark-10 test stand applied a gradual and continuous axial load on the articular surface of the distal radius. A Mark-10 force gauge measured the resultant transverse force experienced by the radial head in the proximal radioulnar joint. Classical mechanics and static force analysis were applied in order to predict lateral force values that would occur when the interosseous ligament is treated as the major load transmitter between the radius and ulna. Acquired data show that the radial head bears a force in the transverse direction that averages 18% (SD 3.89%) in magnitude of the axial force applied at the wrist. This figure is in close accordance with the predicted value of 22% that was calculated by way of free-body plotting. Physiologic forearm loading results in a clinically significant transverse force component transmitted through the interosseous ligament complex. The existence of transverse forces in the human forearm may explain clinical problems seen after radial head resection and suggest that radial head implants be designed to sustain substantial transverse forces. Basic science study, anatomical. Copyright © 2015 Elsevier Ltd. All rights reserved.

[The Amsterdam wrist rules: the multicenter prospective derivation and external validation of a clinical decision rule for the use of radiography in acute wrist trauma].

PubMed

Walenkamp, Monique M J; Bentohami, Abdelali; Slaar, Annelie; Beerekamp, M S H Suzan; Maas, Mario; Jager, L C Cara; Sosef, Nico L; van Velde, Romuald; Ultee, Jan M; Steyerberg, Ewout W; Goslings, J C Carel; Schep, Niels W L

2016-01-01

Although only 39% of patients with wrist trauma have sustained a fracture, the majority of patients is routinely referred for radiography. The purpose of this study was to derive and externally validate a clinical decision rule that selects patients with acute wrist trauma in the Emergency Department (ED) for radiography. This multicenter prospective study consisted of three components: (1) derivation of a clinical prediction model for detecting wrist fractures in patients following wrist trauma; (2) external validation of this model; and (3) design of a clinical decision rule. The study was conducted in the EDs of five Dutch hospitals: one academic hospital (derivation cohort) and four regional hospitals (external validation cohort). We included all adult patients with acute wrist trauma. The main outcome was fracture of the wrist (distal radius, distal ulna or carpal bones) diagnosed on conventional X-rays. A total of 882 patients were analyzed; 487 in the derivation cohort and 395 in the validation cohort. We derived a clinical prediction model with eight variables: age; sex, swelling of the wrist; swelling of the anatomical snuffbox, visible deformation; distal radius tender to palpation; pain on radial deviation and painful axial compression of the thumb. The Area Under the Curve at external validation of this model was 0.81 (95% CI: 0.77-0.85). The sensitivity and specificity of the Amsterdam Wrist Rules (AWR) in the external validation cohort were 98% (95% CI: 95-99%) and 21% (95% CI: 15%-28). The negative predictive value was 90% (95% CI: 81-99%). The Amsterdam Wrist Rules is a clinical prediction rule with a high sensitivity and negative predictive value for fractures of the wrist. Although external validation showed low specificity and 100 % sensitivity could not be achieved, the Amsterdam Wrist Rules can provide physicians in the Emergency Department with a useful screening tool to select patients with acute wrist trauma for radiography. The upcoming implementation study will further reveal the impact of the Amsterdam Wrist Rules on the anticipated reduction of X-rays requested, missed fractures, Emergency Department waiting times and health care costs.

Accelerated bone loss in older men: Effects on bone microarchitecture and strength.

PubMed

Cauley, J A; Burghardt, A J; Harrison, S L; Cawthon, P M; Schwartz, A V; Connor, E Barrett; Ensrud, Kristine E; Langsetmo, Lisa; Majumdar, S; Orwoll, E

2018-05-11

Accelerated bone loss (ABL) shown on routine dual-energy X-ray absorptiometry (DXA) may be accompanied by microarchitectural changes, increased cortical porosity and lower bone strength. To test this hypothesis, we performed a cross-sectional study and used high resolution peripheral quantitative computed tomography (HR-pQCT) scans (SCANCO, Inc., Switzerland) to measure estimated bone strength and microarchitecture in the distal radius and distal and diaphyseal tibia. We studied 1628 men who attended the Year 14 exam of the Osteoporotic Fractures in Men (MrOS) study. We retrospectively characterized areal (a) bone mineral density (BMD) change from the Year 7 to Year 14 exam in 3 categories: "accelerated" >10% loss at either the total hip or femoral neck, (N = 299, 18.4%); "expected" loss, <10%, (N = 1061, 65.2%) and "maintained" BMD, ≥0%, (N = 268, 16.5%). The ABL cutoff was a safety alert established for MrOS. We used regression models to calculate adjusted mean HR-pQCT parameters in men with ABL, expected loss or maintained BMD. Men who experienced ABL were older and had a lower body mass index and aBMD and experienced greater weight loss compared to other men. Total volumetric BMD and trabecular and cortical volumetric BMD were lower in men with ABL compared to the expected or maintained group. Men with ABL had significantly lower trabecular bone volume fraction (BV/TV), fewer trabeculae and greater trabecular separation at both the distal radius and tibia than men with expected loss or who maintained aBMD, all p trend <0.001. Men with ABL had lower cortical thickness and lower estimated bone strength but there was no difference in cortical porosity except at the tibia diaphyseal site In summary, men with ABL have lower estimated bone strength, poorer trabecular microarchitecture and thinner cortices than men without ABL but have similar cortical porosity. These impairments may lead to an increased risk of fracture. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Low volumetric BMD is linked to upper-limb fracture in pubertal girls and persists into adulthood: a seven-year cohort study.

PubMed

Cheng, Sulin; Xu, Leiting; Nicholson, Patrick H F; Tylavsky, Frances; Lyytikäinen, Arja; Wang, Qingju; Suominen, Harri; Kujala, Urho M; Kröger, Heikki; Alen, Markku

2009-09-01

The aetiology of increased incidence of fracture during puberty is unclear. This study aimed to determine whether low volumetric bone mineral density (vBMD) in the distal radius is associated with upper-limb fractures in growing girls, and whether any such vBMD deficit persists into adulthood. Fracture history from birth to 20 years was obtained and verified by medical records in 1034 Finnish girls aged 10-13 years. Bone density and geometry at distal radius, biomarkers and lifestyle/behavioural factors were assessed in a subset of 396 girls with a 7.5-year follow-up. We found that fracture incidence peaked during puberty (relative risk 3.1 at age of 8-14 years compared to outside this age window), and 38% of fractures were in the upper-limb. Compared to the non-fracture cohort, girls who sustained upper-limb fracture at ages 8-14 years had lower distal radial vBMD at baseline (258.9+/-37.5 vs. 287.5+/-34.1 mg/cm(3), p=0.001), 1-year (252.0+/-29.3 vs. 282.6+/-33.5 mg/cm(3), p=0.001), 2-year (258.9+/-32.2 vs. 289.9+/-40.1 mg/cm(3), p=0.003), and 7-year follow-ups (early adulthood, 307.6+/-35.9 vs. 343.6+/-40.9 mg/cm(3), p=0.002). There was a consistent trend towards larger bone cross-sectional area in the fracture cohort compared to non-fracture. In a logistic regression model, lower vBMD (p=0.001) was the only significant predictor of upper-limb fracture during the period of 8-14 years. Our results indicate that low BMD is an important factor underlying elevated upper-limb fracture risk during puberty, and that low BMD in pubertal girls with fracture persists into adulthood. Hence low vBMD during childhood is not a transient deficit. Methods to monitor vBMD and to maximise bone mineral accrual and reduce risks of falling in childhood should be developed.

Calculating Transition Energy Barriers and Characterizing Activation States for Steps of Fusion.

PubMed

Ryham, Rolf J; Klotz, Thomas S; Yao, Lihan; Cohen, Fredric S

2016-03-08

We use continuum mechanics to calculate an entire least energy pathway of membrane fusion, from stalk formation, to pore creation, and through fusion pore enlargement. The model assumes that each structure in the pathway is axially symmetric. The static continuum stalk structure agrees quantitatively with experimental stalk architecture. Calculations show that in a stalk, the distal monolayer is stretched and the stored stretching energy is significantly less than the tilt energy of an unstretched distal monolayer. The string method is used to determine the energy of the transition barriers that separate intermediate states and the dynamics of two bilayers as they pass through them. Hemifusion requires a small amount of energy independently of lipid composition, while direct transition from a stalk to a fusion pore without a hemifusion intermediate is highly improbable. Hemifusion diaphragm expansion is spontaneous for distal monolayers containing at least two lipid components, given sufficiently negative diaphragm spontaneous curvature. Conversely, diaphragms formed from single-component distal monolayers do not expand without the continual injection of energy. We identify a diaphragm radius, below which central pore expansion is spontaneous. For larger diaphragms, prior studies have shown that pore expansion is not axisymmetric, and here our calculations supply an upper bound for the energy of the barrier against pore formation. The major energy-requiring deformations in the steps of fusion are: widening of a hydrophobic fissure in bilayers for stalk formation, splay within the expanding hemifusion diaphragm, and fissure widening initiating pore formation in a hemifusion diaphragm. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

[Clinical randomized controlled trial on ultrashort wave and magnetic therapy for the treatment of early stage distal radius fractures].

PubMed

Wang, Guan-Jie; Liu, Jia

2012-07-01

To explore the effect of application of ultrashort wave and magnetic therapy instrument on the swelling regression in distal radius fractures treated by splint external fixation in initial stage. From March 2007 to May 2010,90 patients with distal radial fracture were treated by manual reduction and splint external fixation. After manual reduction and small splints external fixation, these patients were randomly divided into electrical physical therapy group, western medicine group and the control group by the order of calling number, with 30 cases each group. In control group, there were 9 males and 21 females with an average age of (61.29 +/- 1.97) years, the patients raised and exercise the limb and fingers only. The other two groups also carried out this treatment. In electrical physical therapy group, there were 9 males and 21 females with an average age of (62.37 +/- 2.48) years, the patients were treated with ultrashort wave and magnetic therapy instrument for early intervention, once a day, 5 days for a course of treatment and three cycle were operated. In western medicine group,there were 8 males and 22 females with an average age of (60.12 +/- 2.87) years, the patients were injected with beta-aescin (20 mg, intravenous injection,once a day) for 5 days, followed by Danshen injection (20 ml, intravenous injection, once a day) for 10 days. The limb swelling of patients were assessed every day for 20 days after manual reduction and small splints external fixation. The time of swelling regression in electrical physical therapy group, western medicine group and the control group were respectively (9.62 +/- 3.32), (10.05 +/- 3.05) and (14.57 +/- 2.93) days. Both of that in electrical physical therapy group and western medicine group were shorter than that in the control group (P<0.05), then there were not statistical difference between electrical physical therapy group and western medicine group (P>0.05). The effective rate of swelling regression in electrical physical therapy group, western medicine group and the control group were 86.67%, 80.00%, 46.66% respectively. There was no significant differences between electrical physical therapy group and western medicine group in the curative effect, but both of them had advantage over the control group. Application of ultrashort wave and magnetic therapy instrument for treatment of distal radial fractures in initial stage can promote the regression of limb swelling evidently, which is similar to the intravenous infusion of beta-aescin injection and Danshen injection in curative effect.

Influence of thermal deformation in cavity mirrors on beam propagation characteristics of high-power slab lasers

NASA Astrophysics Data System (ADS)

Wang, Zhen; Xiao, Longsheng; Wang, Wei; Wu, Chao; Tang, Xiahui

2018-01-01

Owing to their good diffusion cooling and low sensitivity to misalignment, slab-shape negative-branch unstable-waveguide resonators are widely used for high-power lasers in industry. As the output beam of the resonator is astigmatic, an external beam shaping system is required. However, the transverse dimension of the cavity mirrors in the resonator is large. For a long-time operation, the heating of cavity mirrors can be non-uniform. This results in micro-deformation and a change in the radius of curvature of the cavity mirrors, and leads to an output beam of an offset optical axis of the resonator. It was found that a change in the radius of curvature of 0.1% (1 mm) caused by thermal deformation generates a transverse displacement of 1.65 mm at the spatial filter of the external beam shaping system, and an output power loss of more than 80%. This can potentially burn out the spatial filter. In order to analyze the effect of the offset optical axis of the beam on the external optical path, we analyzed the transverse displacement and rotational misalignments of the spatial filter. For instance, if the transverse displacement was 0.3 mm, the loss in the output power was 9.6% and a sidelobe appeared in the unstable direction. If the angle of rotation was 5°, the loss in the output power was 2%, and the poles were in the direction of the waveguide. Based on these results, by adjusting the bending mirror, the deviation angle of the output beam of the resonator cavity was corrected, in order to obtain maximum output power and optimal beam quality. Finally, the propagation characteristics of the corrected output beam were analyzed.

Association of genetic variants of MAOA and SH2B1 with bone mineral density in community-dwelling Japanese women.

PubMed

Yamada, Yoshiji; Ando, Fujiko; Shimokata, Hiroshi

2008-01-01

Although bone mineral density (BMD) is a complex trait that is influenced by both genetic and environmental factors, heritability studies in twins and families have shown that genetic factors account for 60-85% of its variance. We examined the relation of the variable number of tandem repeats (VNTR) polymorphism of the monoamine oxidase A gene (MAOA) and the A↷G (Thr484Ala) polymorphism of the SH2B adaptor protein 1 gene (SH2B1) to BMD in community-dwelling Japanese women and men. The 2235 subjects (1107 women, 1128 men) were aged 40-79 years and were randomly recruited for a population-based prospective cohort study of aging and age-related diseases in Japan. BMD at the distal and proximal radius was measured by peripheral quantitative computed tomography, and the BMD of the total body, lumbar spine (L2-L4), right femoral neck and right trochanter was measured by dual-energy X-ray absorptiometry. The genotypes of the VNTR polymorphism of MAOA were determined by DNA fragment analysis, and those of the A↷G (Thr484Ala) polymorphism of SH2B1 by melting curve analysis. The VNTR polymorphism of MAOA was associated with the BMD of the distal radius, total body, lumbar spine and trochanter in all women, and with the BMD of the total body and trochanter in postmenopausal ones, with the L (four repeats) and S (two or three repeats) alleles reflecting increased and decreased BMD, respectively. The A↷G (Thr484Ala) polymorphism of SH2B1 was associated with the BMD of the lumbar spine in all women, with the BMD of the proximal radius in premenopausal women and with the BMD of the lumbar spine, femoral neck and trochanter in postmenopausal women, with the variant G allele being related to increased BMD. These results suggest that MAOA and SH2B1 are determinative loci for bone mass in Japanese women, especially in postmenopausal ones.

Abnormal Canine Bone Development Associated with Hypergravity Exposure

NASA Technical Reports Server (NTRS)

Morgan, J. P.; Fisher, G. L.; McNeill, K. L.; Oyama, J.

1979-01-01

Chronic centrifugation of 85- to 92-day-old Beagles at 2.0 x g and 2.6 x g for 26 weeks during the time of active skeletal growth caused skeletal abnormalities in the radius and the ulna of ten of 11 dogs. The pattern of change mimicked that found in naturally occurring and experimentally induced premature distal ulnar physeal closure or delayed growth at this physis. Minimal changes in bone density were detected by sensitive photon absorptiometric techniques. Skeletal abnormalities also were found in five of the six cage-control dogs, although the run-control dogs were radiographically normal.

The origin of a coarse lithic breccia in the 34 ka caldera-forming Sounkyo eruption, Taisetsu volcano group, central Hokkaido, Japan

NASA Astrophysics Data System (ADS)

Yasuda, Y.; Suzuki-Kamata, K.

2018-05-01

The 34 ka Sounkyo eruption produced 7.6 km3 of tephra ( 5 km3 DRE) as fallout, ignimbrite, and lithic breccia units, forming a small, 2-km-diameter summit caldera in the Taisetsu volcano group, Japan. The Sounkyo eruption products are made up of five eruptive units (SK-A to -E) in proximal regions, corresponding to the distal deposits, a 1- to 2-m-thick pumice fallout and the Px-type ignimbrite up to 220 m thick. The eruption began with a fallout phase, producing unstable low eruption columns during the earlier phase to form a <7-m-thick succession of well-stratified fallouts (SK-A1 and the lower part of the distal fallout). The eruption column reached up to 25 km high (subplinian to plinian) and became more stable at the late of the phase, producing a < 60-m-thick, pumice-dominated fallout (SK-A2 and the upper part of the distal fallout). The second phase, the climax of the Sounkyo eruption, produced a widespread, valley-filling ignimbrite in both proximal and distal regions (SK-B and the Px-type ignimbrite). At the end of the climactic phase, the waning of the eruption led to extensive failure of the walls of the shallow conduit, generating a dense, lithic-rich, low-mobile pyroclastic density current (PDC) to form a >27-m-thick, unstratified and ungraded, coarse lithic breccia (SK-C). The failure in turn choked the conduit, and then the eruption stopped. After a short eruptive hiatus, the eruption resumed with a short-lived fall phase, establishing an eruption column up to 16 km high and producing a <6-m-thick scoria fallout (SK-D). Finally, the eruption ended with the generation of PDCs by eruption column collapse to form a 5- to 15-m-thick ignimbrite in the proximal area (SK-E). Volume relationships between the caldera, ejected magma, and ejected lithic fragments suggest that the caldera was not essentially formed by caldera collapse but, instead, by vent widening as a consequence of explosive erosion and failure of the shallow conduit. The dominance of shallow-origin volcanic rocks in the lithic fraction throughout the Sounkyo eruption products implies the development of a flaring funnel-shaped vent. Hence, the occurrence of lithic breccias within small caldera-forming eruption products does not necessarily reflect either the existence or the timing of caldera collapse, as commonly assumed in literature. Lithic breccias commonly overlie climactic ignimbrite/fallout deposits in small caldera-forming eruptions, and an alternative explanation is that this reflects the collapse of the shallow conduit after an eruption climax, whose walls had been highly fractured and had become unstable owing to progressive erosion.

Instability patterns in a miscible core annular flow

NASA Astrophysics Data System (ADS)

D'Olce, Marguerite; Martin, Jerome; Rakotomalala, Nicole; Salin, Dominique; Talon, Laurent

2006-11-01

Laboratoire FAST, batiment 502, campus universitaire, 91405 Orsay Cedex (France). Experiments are performed with two miscible fluids of equal density but different viscosities. The fluids are injected co-currently and concentrically into a cylindrical pipe. The so-obtained base state is an axisymmetric parallel flow, for which the ratio of the flow rates of the two fluids monitors the relative amount (and so the radius) of the fluids. Depending on this relative amount and on the total flow rate of the fluids, unstable axisymmetric patterns such as mushrooms and pearls are observed. We delineate the diagram of occurrence of the two patterns and characterize the instabilities.

Bone Parameters in Anorexia Nervosa and Athletic Amenorrhea: Comparison of Two Hypothalamic Amenorrhea States.

PubMed

Kandemir, Nurgun; Slattery, Meghan; Ackerman, Kathryn E; Tulsiani, Shreya; Bose, Amita; Singhal, Vibha; Baskaran, Charumathi; Ebrahimi, Seda; Goldstein, Mark; Eddy, Kamryn; Klibanski, Anne; Misra, Madhusmita

2018-04-05

We have reported low bone mineral density (BMD), impaired bone structure, and increased fracture risk in anorexia nervosa (AN) and normal-weight, oligo-amenorrheic athletes (OA). However, data directly comparing compartment-specific bone parameters in AN, OA and controls are lacking. 426 females 14-21.9 years old were included; 231 AN, 94 OA and 101 normal-weight eumenorrheic controls. Dual energy x-ray absorptiometry was used to assess areal BMD (aBMD) of the whole body less head (WBLH), spine, and hip. High resolution peripheral quantitative CT was used to assess volumetric BMD (vBMD), bone geometry and structure at the non-weight bearing distal radius and weight-bearing distal tibia. AN had lower WBLH and hip aBMD Z-scores than OA and controls (p<0.0001). AN and OA had lower spine aBMD Z-scores than controls (p<0.01). At the radius, total and cortical vBMD, percent cortical area and thickness were lower in AN and OA vs. controls (p≤0.04); trabecular vBMD was lower in AN than controls. At the tibia, AN had lower measures for most parameters vs. OA and controls (p<0.05); OA had lower cortical vBMD than controls (p=0.002). AN and OA had higher fracture rates vs. controls. Stress fracture prevalence was highest in OA (p<0.0001); non-stress fracture prevalence was highest in AN (p<0.05). AN is deleterious to bone at all sites and both bone compartments. A high stress fracture rate in OA, who have comparable WBLH and hip aBMD measures to controls, indicates that BMD in these women may need to be even higher to avoid fractures.

Conservative Treatment of Distal Radius Fractures: A Prospective Descriptive Study.

PubMed

Aparicio, Pilar; Izquierdo, Óscar; Castellanos, Juan

2017-06-01

Disability of the upper limb is one of the consequences of distal radius fracture (DRF). The outcome of DRF treatment is based on objective clinical variables, as strength or range of movement (ROM); sometimes these variables do not correlate with the functional level of the patient. The principal objective of our study was to assess the repercussion of conservative treatment of DRF on upper limb disability. This is a retrospective review of prospectively collected data. We collected data of 61 nonconsecutive DRFs treated conservatively from July 2007 to August 2008. Average Disabilities of the Arm, Shoulder and Hand (DASH) score before fracture was 20.8 points; average DASH score after the fracture was 42.6. There was a significant increase in the upper limb disability after 1 year of follow-up in the patients treated conservatively ( P < .001; size effect, 1.06). Average radial inclination, radial tilt, and radial length were 18.18°, 3.35°, and 5.76 mm, respectively. Average ROM for flexion-extension was 100.6° and for pronation-supination 144.0°. ROM for flexion-extension of the unaffected wrist was 128.2° and for pronation-supination 172.4°. We did not find any significant statistical correlation between the increase in disability and the decrease in the ROM ( P > .05). We did not find any significant statistical correlation between the increase in the disability and the worsening in the radiological parameters ( P > .05). Our results confirm the hypothesis that the conservative treatment of DRF produced an increase in the upper limb disability after 1 year of follow-up. Our study does not show a correlation between the increase in upper limb disability and the decrease in wrist ROM. Our study did not find a correlation between radiological measures and DASH scores.

Factors associated with appendicular bone mass in older women. The Study of Osteoporotic Fractures Research Group.

PubMed

Bauer, D C; Browner, W S; Cauley, J A; Orwoll, E S; Scott, J C; Black, D M; Tao, J L; Cummings, S R

1993-05-01

To determine the factors associated with appendicular bone mass in older women. Cross-sectional analysis of baseline data collected for a multicenter, prospective study of osteoporotic fractures. Four clinical centers in Baltimore, Maryland; Minneapolis, Minnesota; Portland, Oregon; and the Monongahela valley, Pennsylvania. A total of 9704 ambulatory, nonblack women, ages 65 years or older, recruited from population-based listings. Demographic and historical information and anthropometric measurements were obtained from a baseline questionnaire, interview, and examination. Single-photon absorptiometry scans were obtained at three sites: the distal radius, midradius, and calcaneus. Multivariate associations with bone mass were first examined in a randomly selected half of the cohort (training group) and were then tested on the other half of the cohort (validation group). In order of decreasing strength of association, estrogen use, non-insulin-dependent diabetes, thiazide use, increased weight, greater muscle strength, later age at menopause, and greater height were independently associated with higher bone mass. Gastric surgery, age, history of maternal fracture, smoking, and caffeine intake were associated with lower bone mass (all P < 0.05). For example, we found that 2 or more years of estrogen use was associated with a 7.2% increase in distal radius bone mass, whereas gastrectomy was associated with an 8.2% decrease in bone mass. The associations between bone mass and dietary calcium intake and rheumatoid arthritis were inconsistent. Alcohol use, physical activity, use of calcium supplements, pregnancy, breast-feeding, parental nationality, and hair color were among the many variables not associated with bone mass. Multivariate models accounted for 20% to 35% of the total variance of bone mass. A large number of factors influence the bone mass of elderly women; however, age, weight, muscle strength, and estrogen use are the most important factors.

Insulin Resistance Is Associated With Smaller Cortical Bone Size in Nondiabetic Men at the Age of Peak Bone Mass.

PubMed

Verroken, Charlotte; Zmierczak, Hans-Georg; Goemaere, Stefan; Kaufman, Jean-Marc; Lapauw, Bruno

2017-06-01

In type 2 diabetes mellitus, fracture risk is increased despite preserved areal bone mineral density. Although this apparent paradox may in part be explained by insulin resistance affecting bone structure and/or material properties, few studies have investigated the association between insulin resistance and bone geometry. We aimed to explore this association in a cohort of nondiabetic men at the age of peak bone mass. Nine hundred ninety-six nondiabetic men aged 25 to 45 years were recruited in a cross-sectional, population-based sibling pair study at a university research center. Insulin resistance was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR), with insulin and glucose measured from fasting serum samples. Bone geometry was assessed using peripheral quantitative computed tomography at the distal radius and the radial and tibial shafts. In age-, height-, and weight-adjusted analyses, HOMA-IR was inversely associated with trabecular area at the distal radius and with cortical area, periosteal and endosteal circumference, and polar strength strain index at the radial and tibial shafts (β ≤ -0.13, P < 0.001). These associations remained essentially unchanged after additional adjustment for dual-energy X-ray absorptiometry-derived body composition, bone turnover markers, muscle size or function measurements, or adiponectin, leptin, insulin-like growth factor 1, or sex steroid levels. In this cohort of nondiabetic men at the age of peak bone mass, insulin resistance is inversely associated with trabecular and cortical bone size. These associations persist after adjustment for body composition, muscle size or function, or sex steroid levels, suggesting an independent effect of insulin resistance on bone geometry. Copyright © 2017 Endocrine Society

Assessment of a novel biomechanical fracture model for distal radius fractures

PubMed Central

2012-01-01

Background Distal radius fractures (DRF) are one of the most common fractures and often need surgical treatment, which has been validated through biomechanical tests. Currently a number of different fracture models are used, none of which resemble the in vivo fracture location. The aim of the study was to develop a new standardized fracture model for DRF (AO-23.A3) and compare its biomechanical behavior to the current gold standard. Methods Variable angle locking volar plates (ADAPTIVE, Medartis) were mounted on 10 pairs of fresh-frozen radii. The osteotomy location was alternated within each pair (New: 10 mm wedge 8 mm / 12 mm proximal to the dorsal / volar apex of the articular surface; Gold standard: 10 mm wedge 20 mm proximal to the articular surface). Each specimen was tested in cyclic axial compression (increasing load by 100 N per cycle) until failure or −3 mm displacement. Parameters assessed were stiffness, displacement and dissipated work calculated for each cycle and ultimate load. Significance was tested using a linear mixed model and Wald test as well as t-tests. Results 7 female and 3 male pairs of radii aged 74 ± 9 years were tested. In most cases (7/10), the two groups showed similar mechanical behavior at low loads with increasing differences at increasing loads. Overall the novel fracture model showed a significant different biomechanical behavior than the gold standard model (p < 0,001). The average final loads resisted were significantly lower in the novel model (860 N ± 232 N vs. 1250 N ± 341 N; p = 0.001). Conclusion The novel biomechanical fracture model for DRF more closely mimics the in vivo fracture site and shows a significantly different biomechanical behavior with increasing loads when compared to the current gold standard. PMID:23244634

Testing the validity of preventing chronic regional pain syndrome with vitamin C after distal radius fracture. [Corrected].

PubMed

Malay, Sunitha; Chung, Kevin C

2014-11-01

The American Academy of Orthopaedic Surgeons recommends the use of vitamin C to prevent complex regional pain syndrome (CRPS) for patients with distal radius fractures (DRFs). We hypothesized that the evidence for supporting this recommendation is weak, based on epidemiological principles of association and causality. The specific aim of this project was to test the validity of this recommendation. We conducted a literature review to retrieve articles reporting on the use of vitamin C to prevent CRPS. Data collected included sample size, study design type, dose of vitamin C used, and outcome measures of association expressed as relative risk (RR) and odds ratio. We then applied Hill criteria to evaluate the relationship between vitamin C and CRPS. We obtained 225 articles from the database search. After the exclusion of duplicates, unrelated articles, editorial letters, and commentaries, we found 4 articles and 1 systematic review relevant to our topic. Six of the 9 Hill criteria were met, and an earlier meta-analysis showed a quantified reduction in CRPS risk. However, criteria like biological plausibility, specificity, and coherence were not met. The number of causal/association criteria met was adequate to support the scientific premise of the effect of vitamin C in preventing CRPS after DRF. Furthermore, vitamin C administration is of relatively low cost and has few complications unless administered in large doses. Owing to sufficient epidemiological evidence availability, the American Academy of Orthopaedic Surgeons recommendation of vitamin C to prevent CRPS has practical merit. Therapeutic II. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Design and evaluation of a portable intra-operative unified-planning-and-guidance framework applied to distal radius fracture surgery.

PubMed

Magaraggia, Jessica; Wei, Wei; Weiten, Markus; Kleinszig, Gerhard; Vetter, Sven; Franke, Jochen; John, Adrian; Egli, Adrian; Barth, Karl; Angelopoulou, Elli; Hornegger, Joachim

2017-01-01

During a standard fracture reduction and fixation procedure of the distal radius, only fluoroscopic images are available for planning of the screw placement and monitoring of the drill bit trajectory. Our prototype intra-operative framework integrates planning and drill guidance for a simplified and improved planning transfer. Guidance information is extracted using a video camera mounted onto a surgical drill. Real-time feedback of the drill bit position is provided using an augmented view of the planning X-rays. We evaluate the accuracy of the placed screws on plastic bones and on healthy and fractured forearm specimens. We also investigate the difference in accuracy between guided screw placement versus freehand. Moreover, the accuracy of the real-time position feedback of the drill bit is evaluated. A total of 166 screws were placed. On 37 plastic bones, our obtained accuracy was [Formula: see text] mm, [Formula: see text] and [Formula: see text] in tip position and orientation (azimuth and elevation), respectively. On the three healthy forearm specimens, our obtained accuracy was [Formula: see text] mm, [Formula: see text] and [Formula: see text]. On the two fractured specimens, we attained: [Formula: see text] mm, [Formula: see text] and [Formula: see text]. When screw plans were applied freehand (without our guidance system), the achieved accuracy was [Formula: see text] mm, [Formula: see text], while when they were transferred under guidance, we obtained [Formula: see text] mm, [Formula: see text]. Our results show that our framework is expected to increase the accuracy in screw positioning and to improve robustness w.r.t. freehand placement.

Comparison of Risk of Carpal Tunnel Syndrome in Patients with Distal Radius Fractures After 7 Treatments

PubMed Central

Zhao, Huan-Li; Wang, Gui-Bin; Jia, Yue-Qing; Zhu, Shi-Cai; Zhang, Feng-Fang; Liu, Hong-Mei

2015-01-01

Background To compare risk of carpal tunnel syndrome (CTS) in distal radius fracture (DRF) patients after 7 treatments using bridging external fixation (BrEF), non-bridging external fixation (non-BrEF), plaster fixation, K-wire fixation, dorsal plating fixation, volar plating fixation, and dorsal and volar plating by performing a network meta-analysis. Material/Methods An exhaustive search of electronic databases identified randomized controlled trails (RCTs) closely related to our study topic. The published articles were screened, based on predefined inclusion and exclusion criteria, to select high-quality studies for the present network meta-analysis. Data extracted from the selected studies were analyzed using STATA version 12.0 software. Results The literature search and selection process identified 12 eligible RCTs that contained a total of 1370 DRF patients (394 patients with BrEF, 377 patients with non-BrEF, 89 patients with K-wire fixation, 192 patients with plaster fixation, 42 patients with dorsal plating fixation, 152 patients with volar plating fixation, and 124 patients with dorsal and volar plating fixation). Our network meta-analysis results demonstrated no significant differences in CTS risk among the 7 treatments (P>0.05). The value of surface under the cumulative ranking curve (SUCRA), however, suggested that dorsal plating fixation is the optimal treatment, with the lowest risk of CTS in DRF patients (dorsal plating fixation: 89.2%; dorsal and volar plating: 57.8%; plaster fixation: 50.9%; non-BrEF: 50.6%; volar plating fixation: 39.6%; BrEF: 38.4%; K-wire fixation: 23.6%). Conclusions Our network meta-analysis provides evidence that dorsal plating fixation significantly decreases the risk of CTS and could be the method of choice in DRF patients. PMID:26391617

Comparison of effects of seven treatment methods for distal radius fracture on minimizing complex regional pain syndrome

PubMed Central

Sun, Tao

2016-01-01

Introduction Using network meta-analysis, we evaluated the adverse effects of the seven most common treatment methods, i.e., bridging external fixation, non-bridging external fixation, K-wire fixation, plaster fixation, dorsal plating, volar plating, and dorsal and volar plating, by their associated risk of developing complex regional pain syndrome (CRPS) in distal radius fracture (DRF) patients. Material and methods Following an exhaustive search of scientific literature databases for high quality studies, randomized controlled trials (RCTs) related to our study topic were screened and selected based on stringent predefined inclusion and exclusion criteria. Data extracted from the selected studies were used for statistical analyses using Stata 12.0 software. Results A total of 17 RCTs, including 1658 DRF patients, were enrolled in this network meta-analysis. Among the 1658 DRF patients, 452 received bridging external fixation, 525 received non-bridging external fixation, 154 received K-wire fixation, 84 received plaster fixation, 132 received dorsal plating, 123 received volar plating, and 188 received dorsal and volar plating. When compared to bridging external fixation patients, there was no marked difference in the CRPS risk in DRF patients receiving different treatments (all p > 0.05). However, the surface under the cumulative ranking curves (SUCRA) for plaster fixation (77.0%) and non-bridging external fixation (71.3%) were significantly higher compared with the other five methods. Conclusions Our findings suggest that compared with bridging external fixation, K-wire fixation, dorsal plating, volar plating, dorsal and volar plating, plaster fixation and non-bridging external fixation might be the better treatment methods to reduce the risk of CRPS in DRF patients. PMID:28144268

Utilization of Post-Acute Care following Distal Radius Fracture among Medicare Beneficiaries

PubMed Central

Zhong, Lin; Mahmoudi, Elham; Giladi, Aviram M.; Shauver, Melissa; Chung, Kevin C.; Waljee, Jennifer F.

2016-01-01

Purpose To examine the utilization and cost of post-acute care following isolated distal radius fractures (DRF) among Medicare beneficiaries. Methods We examined utilization of post-acute care among Medicare beneficiaries who experienced an isolated DRF (n=38,479) during 2007 using 100% Medicare claims data. We analyzed the effect of patient factors on hospital admission following DRF and the receipt of post-acute care delivered by skilled nursing facilities (SNFs), inpatient rehabilitation facilities (IRFs), home healthcare agencies (HHAs), and outpatient OT/PT for the recovery of DRF. Results In this cohort of isolated DRF patients, 1,694 (4.4%) were admitted to hospitals following DRF, and 20% received post-acute care. Women and patients with more comorbid conditions were more likely to require hospital admission. The utilization of post-acute care was higher among women, patients who resided in urban areas, and patients of higher socioeconomic status. The average cost per patient of post-acute care services from IRFs and SNFs ($15,888/patient) was significantly higher than the average cost other aspects of DRF care and accounted for 69% of the total DRF-related expenditure among patients who received inpatient rehabilitation. Conclusions Sociodemographic factors, including sex, socioeconomic status, and age, were significantly correlated with the use of post-acute care following isolated DRFs, and post-acute care accounted for a substantial proportion of the total expenditures related to these common injuries among the elderly. Identifying patients who will derive the greatest benefit from post-acute care can inform strategies to improve the cost-efficiency of rehabilitation and optimize scarce healthcare resources. Level of evidence Therapeutic, III PMID:26527599

FLOATING ELBOW IN CHILDREN: A DESCRIPTIVE STUDY OF 31 CASES ATTENDED IN A REFERENCE CENTER FOR PEDIATRIC TRAUMA.

PubMed

Malheiros, Dorotea Starling; Bárbara, Gustavo Henrique Silva; Mafalda, Leandro Gonçalves; Madureira, João Lopo; Braga, Gilberto Ferreira; Terra, Dalton Lopes

2011-01-01

To conduct a descriptive analysis on 31 cases of children with floating elbow who were attended at our clinic between 1994 and 2009, and to review the literature relating to this topic. Data were obtained through examining the medical records. The following variables were used: age, gender, side, mechanism, type of fracture, classification, treatment and complications. Twenty-four patients (77.4%) were male and seven (22.6%) were female. The mean age was 8.5 (± 3.2) years, ranging from one to 14 years. The left side was predominantly affected (67.7%). The commonest injury mechanism was a fall from a height (74.2%). All the supracondylar fractures were Gartland type III. Distal radius fractures alone, of Salter-Harris type II, were diagnosed in 22 patients (71%). Open fractures occurred in 22 cases (71%). Closed reduction and application of a plaster cast for a closed fracture of the distal radius was performed in two patients (6.45%). Simultaneous conservative treatment for two fractures was not used. Sixteen supracondylar fractures (54.8%) were fixed using crossed wires, at 90° to each other, and in 14 cases (45.16%), an intramedullary wire was used together with another wire introduced through the lateral epicondyle at 45°. The following complications were observed: deformed consolidation (10%), nerve injuries (6%), compartment syndrome (3%) and pin path infection (16%). This is an uncommon injury that in most cases results from high-energy trauma. Surgical treatment for both fractures is recommended by most authors. Ulnar nerve injuries were correlated with the fixation method, but no neurological injuries were triggered by the initial trauma.

FLOATING ELBOW IN CHILDREN: A DESCRIPTIVE STUDY OF 31 CASES ATTENDED IN A REFERENCE CENTER FOR PEDIATRIC TRAUMA

PubMed Central

Malheiros, Dorotea Starling; Bárbara, Gustavo Henrique Silva; Mafalda, Leandro Gonçalves; Madureira, João Lopo; Braga, Gilberto Ferreira; Terra, Dalton Lopes

2015-01-01

Objective: To conduct a descriptive analysis on 31 cases of children with floating elbow who were attended at our clinic between 1994 and 2009, and to review the literature relating to this topic. Methods: Data were obtained through examining the medical records. The following variables were used: age, gender, side, mechanism, type of fracture, classification, treatment and complications. Results: Twenty-four patients (77.4%) were male and seven (22.6%) were female. The mean age was 8.5 (± 3.2) years, ranging from one to 14 years. The left side was predominantly affected (67.7%). The commonest injury mechanism was a fall from a height (74.2%). All the supracondylar fractures were Gartland type III. Distal radius fractures alone, of Salter-Harris type II, were diagnosed in 22 patients (71%). Open fractures occurred in 22 cases (71%). Closed reduction and application of a plaster cast for a closed fracture of the distal radius was performed in two patients (6.45%). Simultaneous conservative treatment for two fractures was not used. Sixteen supracondylar fractures (54.8%) were fixed using crossed wires, at 90° to each other, and in 14 cases (45.16%), an intramedullary wire was used together with another wire introduced through the lateral epicondyle at 45°. The following complications were observed: deformed consolidation (10%), nerve injuries (6%), compartment syndrome (3%) and pin path infection (16%). Conclusions: This is an uncommon injury that in most cases results from high-energy trauma. Surgical treatment for both fractures is recommended by most authors. Ulnar nerve injuries were correlated with the fixation method, but no neurological injuries were triggered by the initial trauma. PMID:27027045

How does bone quality differ between healthy-weight and overweight adolescents and young adults?

PubMed

Hoy, Christa L; Macdonald, Heather M; McKay, Heather A

2013-04-01

Overweight youth have greater bone mass than their healthy-weight peers but sustain more fractures. However, it is unclear whether and how excess body fat influences bone quality in youth. We determined whether overweight status correlated with three-dimensional aspects of bone quality influencing bone strength in adolescent and young adult females and males. We categorized males (n=103; mean age, 17 years) and females (n=85; mean age, 18 years) into healthy-weight and overweight groups. We measured lean mass (LM) and fat mass (FM) with dual-energy x-ray absorptiometry (DXA). We used high-resolution peripheral quantitative CT to assess the distal radius (7% site) and distal tibia (8% site). Bone quality measures included total bone mineral density (Tt.BMD), total area (Tt.Ar), trabecular bone volume fraction (BV/TV), trabecular number (Tb.N), separation (Tb.Sp), and thickness (Tb.Th). We used multiple regression to compare bone quality between healthy-weight and overweight adolescents adjusting for age, ethnicity, limb length, LM, and FM. Overweight males had higher (10%-21%) Tt.BMD, BV/TV, and Tb.N and lower Tb.Sp at the tibia and lower Tt.Ar at the radius than healthy-weight males. No differences were observed between overweight and healthy-weight females. LM attenuated the differences in bone quality between groups in males while FM negatively predicted Tt.BMD, BV/TV, Tb.N, and Tb.Th. Our data suggest overweight males have enhanced bone quality compared with healthy-weight males; however, when group differences are interpreted in the context of the mechanostat theory, it appears bone quality of overweight adolescents adapts to LM and not to greater FM.

Maneuverability by the sea lion Zalophus californianus: turning performance of an unstable body design.

PubMed

Fish, Frank E; Hurley, Jenifer; Costa, Daniel P

2003-02-01

Maneuverability is critical to the performance of fast-swimming marine mammals that use rapid turns to catch prey. Overhead video recordings were analyzed for two sea lions (Zalophus californianus) turning in the horizontal plane. Unpowered turns were executed by body flexion in conjunction with use of the pectoral and pelvic flippers, which were used as control surfaces. A 90 degree bank angle was used in the turns to vertically orient the control surfaces. Turning radius was dependent on body mass and swimming velocity. Relative minimum radii were 9-17% of body length and were equivalent for pinnipeds and cetaceans. However, Zalophus had smaller turning radii at higher speeds than cetaceans. Rate of turn was inversely related to turn radius. The highest turn rate observed in Zalophus was 690 degrees s(-1). Centripetal acceleration measured up to 5.1 g for Zalophus. Comparison with other marine mammals indicates that Zalophus has a morphology that enhances instability, thus providing enhanced turning performance. Enhanced turning performance is necessary for sea lions to forage after highly elusive prey in structurally complex environments.

Formation of large-scale structures with sharp density gradient through Rayleigh-Taylor growth in a two-dimensional slab under the two-fluid and finite Larmor radius effects

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

Goto, R.; Hatori, T.; Miura, H., E-mail: miura.hideaki@nifs.ac.jp

Two-fluid and the finite Larmor effects on linear and nonlinear growth of the Rayleigh-Taylor instability in a two-dimensional slab are studied numerically with special attention to high-wave-number dynamics and nonlinear structure formation at a low β-value. The two effects stabilize the unstable high wave number modes for a certain range of the β-value. In nonlinear simulations, the absence of the high wave number modes in the linear stage leads to the formation of the density field structure much larger than that in the single-fluid magnetohydrodynamic simulation, together with a sharp density gradient as well as a large velocity difference. Themore » formation of the sharp velocity difference leads to a subsequent Kelvin-Helmholtz-type instability only when both the two-fluid and finite Larmor radius terms are incorporated, whereas it is not observed otherwise. It is shown that the emergence of the secondary instability can modify the outline of the turbulent structures associated with the primary Rayleigh-Taylor instability.« less

Effect of long-term impact-loading on mass, size, and estimated strength of humerus and radius of female racquet-sports players: a peripheral quantitative computed tomography study between young and old starters and controls.

PubMed

Kontulainen, Saija; Sievänen, Harri; Kannus, Pekka; Pasanen, Matti; Vuori, Ilkka

2002-12-01

Bone characteristics of the humeral shaft and distal radius were measured from 64 female tennis and squash players and their 27 age-, height-, and weight-matched controls with peripheral quantitative tomography (pQCT) and DXA. The players were divided into two groups according to the starting age of their tennis or squash training (either before or after menarche) to examine the possible differences in the loading-induced changes in bone structure and volumetric density. The used pQCT variables were bone mineral content (BMC), total cross-sectional area (TotA) of bone, cross-sectional area of the marrow cavity (CavA) and that of the cortical bone (CoA), cortical wall thickness (CWT), volumetric density of the cortical bone (CoD) and trabecular bone (TrD), and torsional bone strength index (BSIt) for the shaft, and compressional bone strength index (BSIc) for the bone end. These bone strength indices were compared with the DXA-derived areal bone mineral density (aBMD) to assess how well the latter represents the effect of mechanical loading on apparent bone strength. At the humeral shaft, the loaded arm's greater BMC (an average 19% side-to-side difference in young starters and 9% in old starters) was caused by an enlarged cortex (CoA; side-to-side differences 20% and 9%, respectively). The loaded humerus seemed to have grown periosteally (the CavA did not differ between the sites) leading to 26% and 11% side-to-side BSIt difference in the young and old starters, respectively. CoD was equal between the arms (-1% difference in both player groups). The side-to-side differences in the young starters' BMC, CoA, TotA, CWT, and BSIt were 8-22% higher than those of the controls and 8-14% higher than those of the old starters. Old starters' BMC, CoA, and BSIt side-to-side differences were 6-7% greater than those in the controls. The DXA-derived side-to-side aBMD difference was 7% greater in young starters compared with that of the old starters and 14% compared with that in controls, whereas the difference between old starters and controls was 6%, in favor of the former. All these between-group differences were statistically significant. At the distal radius, the player groups differed significantly from controls in the side-to-side BMC, TrD, and aBMD differences only; the young starters' BMC difference was 9% greater, TrD and aBMD differences were 5% greater than those in the controls, and the old starters' TrD and aBMD differences were both 7% greater than those in the controls. In summary, in both of the female player groups the structural adaptation of the humeral shaft to long-term loading seemed to be achievedthrough periosteal enlargement of the bone cortex although this adaptation was clearly better in the young starters. Exercise-induced cortical enlargement was not so clear at the distal radius (a trabecular bone site), and the study suggested that at long bone ends also the TrD could be a modifiable factor to build a stronger bone structure. The conventional DXA-based aBMD measurement detected the intergroup differences in the exercise-induced bone gains, although, measuring two dimensions of bone only, it seemed to underestimate the effect of exercise on the apparent bone strength, especially if the playing had been started during the growing years.

Theory on the mechanism of distal action of transcription factors: looping of DNA versus tracking along DNA

NASA Astrophysics Data System (ADS)

Murugan, R.

2010-10-01

In this paper, we develop a theory on the mechanism of distal action of the transcription factors, which are bound at their respective cis-regulatory enhancer modules on the promoter-RNA polymerase II (PR) complexes to initiate the transcription event in eukaryotes. We consider both the looping and tracking modes of their distal communication and calculate the mean first passage time that is required for the distal interactions of the complex of enhancer and transcription factor with the PR via both these modes. We further investigate how this mean first passage time is dependent on the length of the DNA segment (L, base-pairs) that connects the cis-regulatory binding site and the respective promoter. When the radius of curvature of this connecting segment of DNA is R that was induced upon binding of the transcription factor at the cis-acting element and RNAPII at the promoter in cis-positions, our calculations indicate that the looping mode of distal action will dominate when L is such that L > 2πR and the tracking mode of distal action will be favored when L < 2πR. The time required for the distal action will be minimum when L = 2πR where the typical value of R for the binding of histones will be R ~ 16 bps and L ~ 102 bps. It seems that the free energy associated with the binding of the transcription factor with its cis-acting element and the distance of this cis-acting element from the corresponding promoter of the gene of interest is negatively correlated. Our results suggest that the looping and tracking modes of distal action are concurrently operating on the transcription activation and the physics that determines the timescales associated with the looping/tracking in the mechanism of action of these transcription factors on the initiation of the transcription event must put a selection pressure on the distribution of the distances of cis-regulatory modules from their respective promoters of the genes. The computational analysis of the upstream sequences of promoters of various genes in the human and mouse genomes for the presence of putative cis-regulatory elements for a set of known transcription factors using the position weight matrices available with the JASPAR database indicates the presence of cis-acting elements with maximum probability at a distance of ~102 bps from the promoters which substantiates our theoretical predictions.

Temporary ipsilateral stiff shoulder after operative fixation of distal radial fractures.

PubMed

Cha, Soo Min; Shin, Hyun Dae; Hwang, Sung Jin

2017-06-01

This study was conducted to identify variables affecting the development of temporary stiff shoulder after operative fixation for distal radial fractures (DRF). The study retrospectively analyzed 167 patients who had undergone internal fixation using volar locking plate for DRF between 2010 and 2013. Group 1 was denoted as the "normal group," and group 2 was denoted as the "stiff shoulder group." Basic demographic factors evaluated included age, sex, bone mineral density (BMD), and the dominancy. Also investigated were radiologic variables, including concurrent fractures of the styloid process, positive ulnar variances, classification of DRF, and morphologic type of the distal radioulnar joint. Finally, the type of plate, methods used for postoperative protection, and time of union were analyzed. Group 1 consisted of 114 patients, and group 2 consisted of 53 patients. On overall univariate analysis, BMD, hand dominancy, and the protective methods after plating were significantly different between the 2 groups. On multivariate analysis, a lower BMD and injury on the nondominant side were significant factors for shoulder stiffness. Stiffness was significantly higher in patients with a mean BMD < -2.6 than in patients with a mean BMD ≥ -2.6. At the final follow-up, all of the 53 patients in group 2 were relieved of the symptoms of a stiff shoulder. A lower BMD and injury on the nondominant distal radius were distinct factors for the development of a stiff shoulder after operative fixation in DRF. Fortunately, nonoperative treatments, such as stretching exercises/injections, were useful for the relief of these symptoms in the short-term follow-up. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

A Numerical Model of Hercules A by Magnetic Tower

NASA Astrophysics Data System (ADS)

Nakamura, Masanori; Tregillis, I. L.; Li, H.; Li, S.

2009-01-01

We apply magnetohydrodynamic (MHD) modeling to the radio galaxy Hercules A for investigating the jet-driven shock, jet/lobe transition, wiggling, and magnetic field distribution associated with this source. The model consists of magnetic tower jets in a galaxy cluster environment. The profile of underlying ambient gas plays an important role in jet-lobe morphology. The balance between the magnetic pressure generated by axial current and the ambient gas pressure can determine the lobe radius. The jet body is confined jointly by the external pressure and gravity inside the cluster core radius, while outside this radius it expands radially to form fat lobes in a steeply decreasing ambient thermal pressure gradient. The current-carrying jets are responsible for generating a strong, tightly wound helical magnetic field. This magnetic configuration will be unstable against the current-driven kink mode and it visibly grows beyond the cluster core radius where a separation between the jet forward and return currents occurs. The reversed pinch profile of global magnetic field associated with the jet and lobes produces projected magnetic-vector distributions aligned with the jet flow and the lobe edge. AGN-driven shock powered by the expanding magnetic tower jet surrounds the jet/lobe structure and heats the ambient ICM. The lobes expand subsonically; no obvious hot spots are produced at the heads of lobes. Several key features in our MHD modeling may be qualitatively supported by the observations of Hercules A. This work was carried out under the auspices of the National Nuclear Security Administration of the U.S. Department of Energy at Los Alamos National Laboratory under Contract No. DE-AC52-06NA25396. It was supported by the Laboratory Directed Research and Development Program at LANL and by IGPP at LANL.

Detectors for MUSE

NASA Astrophysics Data System (ADS)

Hirschman, Jack; Muon Scattering Experiment (MUSE) Collaboration

2017-09-01

Until recently, it was thought that the proton radius was known with an uncertainty of 1%. However, experiments carried-out at the Paul Scherrer Institute (PSI) involving muonic hydrogen yielded a radius 4% smaller with an uncertainty of .1%, a 7.9 σ inconsistency. This problem of properly measuring the radius now requires new and different measurements. The Muon Scattering Experiment (MUSE) will thus be the first to utilize elastic muon scattering with sufficient precision to address the proton radius measurement. MUSE will run in PSI's PiM1 beamline, using a stack of GEM chambers and thin scintillation detectors to identify and track the beam particle species in this mixed e, pi, mu beam. Scattered particles will be measured in two arms with ten layers of Straw Tube Tracking (STT) detectors and a double plastic scintillator wall for timing of and triggering on scattered particles. The STT chambers will employ the anti-Proton Annihilations at Darmstadt (PANDA) design. Each straw consists of a thin wire with high voltage surrounded by an aluminized Mylar tube inflated with a mix of Argon and Carbon Dioxide, the ratio of which is important for optimal operation. The Argon gas, ionized by incoming charged particles, releases electrons which attract to the central wire. The CO2 acts as a quencher, taking-up electrons to prevent an unstable avalanche effect. This project will investigate the effects of altering the gas mixture in the STTs on signal size and timing. This material is based upon work supported by the National Science Foundation under Grant No. OISE-1358175, PHY-1614850, and PHY-1614938. Thank you to the teams at HUJI and PSI, in particular, Dr. G. Ron, Dr. T. Rostomyan, Dr. K. Dieters, and D. Cohen.

BAROCLINIC INSTABILITY IN THE SOLAR TACHOCLINE. II. THE EADY PROBLEM

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

Gilman, Peter A., E-mail: gilman@ucar.edu

2016-02-20

We solve the nongeostrophic baroclinic instability problem for the tachocline for a continuous model with a constant vertical rotation gradient (the Eady problem), using power series generated by the Frobenius method. The results confirm and greatly extend those from a previous two-layer model. For effective gravity G independent of height, growth rates and ranges of unstable longitudinal wavenumbers m and latitudes increase with decreasing G. As with the two-layer model, the overshoot tachocline is much more unstable than the radiative tachocline. The e-folding growth times range from as short as 10 days to as long as several years, depending on latitude,more » G, and wavenumber. For a more realistic effective gravity that decreases linearly from the radiative interior to near zero at the top of the tachocline, we find that only m = 1, 2 modes are unstable, with growth rates somewhat larger than for constant G, with the same value as at the bottom of the tachocline. All results are the same whether we assume that the vertical velocity or the perturbation pressure is zero at the top of the layer; this is a direct consquence of not employing the geostrophic assumption for perturbations. We explain most of the properties of the instability in terms of the Rossby deformation radius. We discuss further improvements in the realism of the model, particularly adding toroidal fields that vary in height, and including latitudinal gradients of both rotation and toroidal fields.« less

Migration of Gas Giant Planets in a Gravitationally Unstable Disk

NASA Astrophysics Data System (ADS)

Desai, Karna Mahadev; Steiman-Cameron, Thomas Y.; Michael, Scott; Durisen, Richard H.

2017-01-01

Understanding the migration of giant planets in gravitationally unstable protoplanetary disks is important for understanding planetary system architecture, especially the existence of planets orbiting close to and at large distances from their stars. Migration rates can determine the efficiency of planet formation and survival rates of planets. We present results from simulations of 0.3, 1, and 3 Jupiter-mass planets in a 0.14 M⊙ protoplanetary disk around a 1 M⊙ star, where the disk is marginally unstable to gravitational instabilities (GIs). Each planet is simulated separately. We use CHYMERA, a radiative 3D hydrodynamics code developed by the Indiana University Hydrodynamics Group. The simulations include radiative cooling governed by realistic dust opacities. The planets are inserted into the disk, once the disk has settled into its quasi-steady GI-active phase. We simulate each of the 0.3, 1, and 3 Jupiter-mass planets by inserting it at three different locations in the disk, at the corotation radius and at the inner and outer Lindblad resonances. No matter where placed, the 3 Jupiter-mass planets tend to drift inexorably inward but with a rate that slows after many orbital periods. The 1 Jupiter-mass planets migrate mostly inward, but their motion can be delayed or reversed near the corotation of the two-armed wave. The 0.3 Jupiter-mass planets are much less predictable and frequently migrate outward. We analyze how the density of matter and waves in the disk at different azimuthal locations affect the migration.

An assessment of the relationship between congenital transverse deficiency of the forearm and symbrachydactyly.

PubMed

Kallemeier, Patricia M; Manske, Paul R; Davis, Benjamin; Goldfarb, Charles A

2007-11-01

A relationship between symbrachydactyly and transverse deficiency has been suggested but has not been critically investigated or established by scientific studies. The purpose of this investigation was to evaluate a large group of patients with transverse deficiency of the forearm for clinical and radiologic features typically seen in patients with symbrachydactyly. A retrospective review of the medical records of 291 patients with a diagnosis of upper-extremity transverse deficiency at the level of the forearm was performed. Patient charts, photographs, and radiographs were evaluated for manifestations of symbrachydactyly; specifically, we clinically assessed for the presence of nubbins and skin invaginations and radiologically assessed for hypoplasia of the proximal radius and ulna. Two hundred seven patients had soft tissue nubbins at the end of their amputation stumps including 38 with the additional finding of skin invagination at the distal end. Another 36 extremities had a skin invagination alone. Twenty-nine of the extremities without nubbins or skin invaginations had hypoplasia of the proximal radius and ulna. Thus, 272 of the 291 extremities with transverse deficiency had manifestations of symbrachydactyly. The majority of patients with the diagnosis of transverse deficiency have soft tissue nubbins, skin invaginations, or hypoplasia of the proximal radius and ulna at the end of their amputation stumps. These clinical and radiologic features support the concept that transverse deficiency through the forearm represents a proximal continuum of symbrachydactyly.

Methods for Improving the Curvature of Steerable Needles in Biological Tissue

PubMed Central

Adebar, Troy K.; Greer, Joseph D.; Laeseke, Paul F.; Hwang, Gloria L.; Okamura, Allison M.

2016-01-01

Robotic needle steering systems have the potential to improve percutaneous interventions such as radiofrequency ablation of liver tumors, but steering techniques described to date have not achieved sufficiently small radius of curvature in biological tissue to be relevant to this application. In this work, the impact of tip geometry on steerable needle curvature is examined. Finite-element simulations and experiments with bent-tip needles in ex vivo liver tissue demonstrate that selection of tip length and angle can greatly improve curvature, with radius of curvature below 5 cm in liver tissue possible through judicious selection of these parameters. Motivated by the results of this analysis, a new articulated-tip steerable needle is described, in which a distal section is actively switched by a robotic system between a straight tip (resulting in a straight path) and a bent tip (resulting in a curved path). This approach allows the tip length and angle to be increased, while the straight configuration allows the needle tip to still pass through an introducer sheath and rotate inside the body. Validation testing in liver tissue shows that the new articulated-tip steerable needle achieves smaller radius of curvature compared to bent-tip needles described in previous work. Steerable needles with optimized tip parameters, which can generate tight curves in liver tissue, increase the clinical relevance of needle steering to percutaneous interventions. PMID:26441438

Development of the 3DHZETRN code for space radiation protection

NASA Astrophysics Data System (ADS)

Wilson, John; Badavi, Francis; Slaba, Tony; Reddell, Brandon; Bahadori, Amir; Singleterry, Robert

Space radiation protection requires computationally efficient shield assessment methods that have been verified and validated. The HZETRN code is the engineering design code used for low Earth orbit dosimetric analysis and astronaut record keeping with end-to-end validation to twenty percent in Space Shuttle and International Space Station operations. HZETRN treated diffusive leakage only at the distal surface limiting its application to systems with a large radius of curvature. A revision of HZETRN that included forward and backward diffusion allowed neutron leakage to be evaluated at both the near and distal surfaces. That revision provided a deterministic code of high computational efficiency that was in substantial agreement with Monte Carlo (MC) codes in flat plates (at least to the degree that MC codes agree among themselves). In the present paper, the 3DHZETRN formalism capable of evaluation in general geometry is described. Benchmarking will help quantify uncertainty with MC codes (Geant4, FLUKA, MCNP6, and PHITS) in simple shapes such as spheres within spherical shells and boxes. Connection of the 3DHZETRN to general geometry will be discussed.

[Osteosynthesis of distal radius fractures by by flexible intramedullary nailing (Geneva experience)].

PubMed

Flisch, C W; Della Santa, D R

1998-01-01

In 1949 Leslie Rush described a new method of management of Colles' fractures by means of a rigid medullary nail. Claude Py in 1969 followed this concept but used two flexible intramedullary pins. After briefly recalling the biomechanical principle and operating technique, the authors outline their series of 39 extra- and intra-articular fractures (10 males and 29 females) operated between March 1995 and April 1996 with an average follow-up of 6.5 months (1.5-14.5 months). The radiological and functional results are discussed: 55% of the cases showed good anatomical reduction whereas 59% achieved a satisfactory functional result. The advantage of this operating technique lies in its simplicity. Nevertheless, considerable experience is necessary owing to the relatively high complication rate (secondary displacement, tendon or nerve lesions, reflex sympathetic dystrophy). However, this method requires only a limited amount of time and remains a good indication for extra-articular and simple articular fractures. In the case of severe posterior comminution, the use of cancellous bone graft can help to prevent secondary dorsal impaction and its repercussion on distal radio-ulnar function.

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

PubMed

Furui, Atsuo; Terada, Nobuki

2017-08-01

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

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

PubMed Central

Sabat, Dhananjaya; Dabas, Vineet; Dhal, Anil

2014-01-01

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. PMID:25143650

Value in Pediatric Orthopaedic Surgery Health Care: the Role of Time-driven Activity-based Cost Accounting (TDABC) and Standardized Clinical Assessment and Management Plans (SCAMPs).

PubMed

Waters, Peter M

2015-01-01

The continuing increases in health care expenditures as well as the importance of providing safe, effective, timely, patient-centered care has brought government and commercial payer pressure on hospitals and providers to document the value of the care they deliver. This article introduces work at Boston Children's Hospital on time-driven activity-based accounting to determine cost of care delivery; combined with Systemic Clinical Assessment and Management Plans to reduce variation and improve outcomes. The focus so far has been on distal radius fracture care for children and adolescents.

Volleyball and Basketball Enhanced Bone Mass in Prepubescent Boys.

PubMed

Zouch, Mohamed; Chaari, Hamada; Zribi, Anis; Bouajina, Elyès; Vico, Laurence; Alexandre, Christian; Zaouali, Monia; Ben Nasr, Hela; Masmoudi, Liwa; Tabka, Zouhair

2016-01-01

The aim of this study was to examine the effect of volleyball and basketball practice on bone acquisition and to determine which of these 2 high-impact sports is more osteogenic in prepubertal period. We investigated 170 boys (aged 10-12 yr, Tanner stage I): 50 volleyball players (VB), 50 basketball players (BB), and 70 controls. Bone mineral content (BMC, g) and bone area (BA, cm(2)) were measured by dual-energy X-ray absorptiometry at different sites. We found that, both VB and BB have a higher BMC at whole body and most weight-bearing and nonweight-bearing sites than controls, except the BMC in head which was lower in VB and BB than controls. Moreover, only VB exhibited greater BMC in right and left ultra-distal radius than controls. No significant differences were observed between the 3 groups in lumbar spine, femoral neck, and left third D radius BMC. Athletes also exhibited a higher BA in whole body, limbs, lumbar spine, and femoral region than controls. In addition, they have a similar BA in head and left third D radius with controls. The VB exhibited a greater BA in most radius region than controls and a greater femoral neck BA than BB. A significant positive correlation was reported between total lean mass and both BMC and BA in whole body, lumbar spine, total hip, and right whole radius among VB and BB. In summary, we suggest that volleyball and basketball have an osteogenic effect BMC and BA in loaded sites in prepubescent boys. The increased bone mass induced by both volleyball and basketball training in the stressed sites was associated to a decreased skull BMC. Moreover, volleyball practice produces a more sensitive mechanical stress in loaded bones than basketball. This effect seems translated by femoral neck expansion. Copyright © 2016 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Bone geometry, volumetric bone mineral density, microarchitecture and estimated bone strength in Caucasian females with systemic lupus erythematosus. A cross-sectional study using HR-pQCT.

PubMed

Hansen, Stinus; Gudex, Claire; Åhrberg, Fabian; Brixen, Kim; Voss, Anne

2014-12-01

Patients with systemic lupus erythematosus (SLE) have an increased risk of fracture. We used high resolution peripheral quantitative computed tomography (HR-pQCT) to measure bone geometry, volumetric bone mineral density (vBMD), cortical and trabecular microarchitecture and estimated bone strength by finite element analysis (FEA) at the distal radius and tibia to assess bone characteristics beyond BMD that may contribute to the increased risk of fracture. Thirty-three Caucasian women with SLE (median age 48, range 21-64 years) and 99 controls (median age 45, range 21-64 years) were studied. Groups were comparable in radius regarding geometry and vBMD, but SLE patients had lower trabecular number (-7%, p < 0.05), higher trabecular separation (13%, p < 0.05) and lower FEA-estimated failure load compared to controls (-10%, p < 0.05). In tibia, SLE patients had lower total vBMD (-11%, p < 0.01), cortical area (-14%, p < 0.001) and cortical thickness (-16%, p < 0.001) and higher trabecular area (8%, p < 0.05). In subgroup analyses of the premenopausal participants (SLE n = 21, controls n = 63), SLE patients had significantly lower trabecular bone volume fraction [(BV/TV); -17%, p < 0.01], trabecular number (-9%, p < 0.01), trabecular thickness (-9%, p < 0.05) and higher trabecular separation (13%, p < 0.01) and trabecular network inhomogeneity (14%, p < 0.05) in radius along with lower BV/TV (-15%, p < 0.01) and higher trabecular separation (11%, p < 0.05) in tibia. FEA-estimated bone strength was lower in both radius (-11%, p < 0.01) and tibia (-10%, p < 0.05). In conclusion, Caucasian women with SLE compared to controls had fewer and more widely separated trabeculae and lower estimated bone strength in radius and lower total vBMD, cortical area and thickness in tibia.

GROWTH DISTURBANCES IN BONE AFTER X IRRADIATION AND RADIUM IRRADIATION FOR HEMANGIOMATA IN CHILDHOOD (in German)

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

Weiss, J.; Gregl, A.

1961-08-01

A number of injuries from radiation treatment of hemangiomata have been reported in the literature; two additional instances are reported here. The left hand of a 9-monthold child was treated for hemangiomata by exposure to 480 mg-hr of Ra. This was followed by skin necrosis with poor healing, and a permanent flexion of the wrist toward the radial side. At age 13, corrective surgery was required. The wrist was scarred on the thumb side, and the flexion formed almost a right angle. The left underarm on the ulnar side was shortened by 4 cm, the reach was shortened by 3.5more » cm, arsi the ball of the thumb was atrophied by 2 cm. The thumb was shortened by 1.7 cm, and the middle and forefinger were each shortened by 0.5 cm. The skeleta1 injuries visualized by x ray showed hypoplasia and shortening of the radius. The radial epiphysis was displaced. The distal end of the ulna was raised and bent. The os naviculare was stunted, the os multangulum was completely missing, and there was hypoplasia of metacarpal I. A satisfactory correction was made by partial resection of the ulna and osteotomy of the radius with 90 deg traction on the peripheral fragments. The patient reported that the hand became occupationally useful. In the second case, hemangioma on the right hand of an 18-month-old child was exposed to five x-ray treatments of 700 r each. After about seven months radial abduction increased at the right wrist. X ray showed 3.5-cm shortening of the right radius, with the epiphysis turned approximates 30 deg toward the radius side. The metaphysis was abnormal and partly sclerotic. The epiphysial trabeculae were coarsened. The wrist bones were hypoplastic. The radius was straightened and the ulna was shortened by osteotomy. (BBB)« less

Extracting nuclear sizes of medium to heavy nuclei from total reaction cross sections

NASA Astrophysics Data System (ADS)

Horiuchi, W.; Hatakeyama, S.; Ebata, S.; Suzuki, Y.

2016-04-01

Background: Proton and neutron radii are fundamental quantities of atomic nuclei. To study the sizes of short-lived unstable nuclei, there is a need for an alternative to electron scattering. Purpose: The recent paper by Horiuchi et al. [Phys. Rev. C 89, 011601(R) (2014)], 10.1103/PhysRevC.89.011601 proposed a possible way of extracting the matter and neutron-skin thickness of light- to medium-mass nuclei using total reaction cross section, σR. The analysis is extended to medium to heavy nuclei up to lead isotopes with due attention to Coulomb breakup contributions as well as density distributions improved by paring correlation. Methods: We formulate a quantitative calculation of σR based on the Glauber model including the Coulomb breakup. To substantiate the treatment of the Coulomb breakup, we also evaluate the Coulomb breakup cross section due to the electric dipole field in a canonical-basis-time-dependent-Hartree-Fock-Bogoliubov theory in the three-dimensional coordinate space. Results: We analyze σR's of 103 nuclei with Z =20 , 28, 40, 50, 70, and 82 incident on light targets, H,21, 4He, and 12C. Three kinds of Skyrme interactions are tested to generate those wave functions. To discuss possible uncertainty due to the Coulomb breakup, we examine its dependence on the target, the incident energy, and the Skyrme interaction. The proton is a most promising target for extracting the nuclear sizes as the Coulomb excitation can safely be neglected. We find that the so-called reaction radius, aR=√{σR/π } , for the proton target is very well approximated by a linear function of two variables, the matter radius and the skin thickness, in which three constants depend only on the incident energy. We quantify the accuracy of σR measurements needed to extract the nuclear sizes. Conclusions: The proton is the best target because, once the incident energy is set, its aR is very accurately determined by only the matter radius and neutron-skin thickness. If σR's at different incident energies are measured, one can determine both the proton and neutron radii for unstable nuclei as well. The total reaction cross sections calculated in this paper are given as Supplemental Material for the sake of future measurements.

Sequence of the Essex-Lopresti lesion—a high-speed video documentation and kinematic analysis

PubMed Central

2014-01-01

Background and purpose The pathomechanics of the Essex-Lopresti lesion are not fully understood. We used human cadavers and documented the genesis of the injury with high-speed cameras. Methods 4 formalin-fixed cadaveric specimens of human upper extremities were tested in a prototype, custom-made, drop-weight test bench. An axial high-energy impulse was applied and the development of the lesion was documented with 3 high-speed cameras. Results The high-speed images showed a transversal movement of the radius and ulna, which moved away from each other in the transversal plane during the impact. This resulted into a transversal rupture of the interosseous membrane, starting in its central portion, and only then did the radius migrate proximally and fracture. The lesion proceeded to the dislocation of the distal radio-ulnar joint and then to a full-blown Essex-Lopresti lesion. Interpretation Our findings indicate that fracture of the radial head may be preceded by at least partial lesions of the interosseous membrane in the course of high-energy axial trauma. PMID:24479620

Record-Breaking Pain: The Largest Number and Variety of Forelimb Bone Maladies in a Theropod Dinosaur.

PubMed

Senter, Phil; Juengst, Sara L

2016-01-01

Bone abnormalities are common in theropod dinosaur skeletons, but before now no specimen was known with more than four afflicted bones of the pectoral girdle and/or forelimb. Here we describe the pathology of a specimen of the theropod dinosaur Dilophosaurus wetherilli with eight afflicted bones of the pectoral girdle and forelimb. On its left side the animal has a fractured scapula and radius and large fibriscesses in the ulna and the proximal thumb phalanx. On its right side the animal has abnormal torsion of the humeral shaft, bony tumors on the radius, a truncated distal articular surface of metacarpal III, and angular deformities of the first phalanx of the third finger. Healing and remodeling indicates that the animal survived for months and possibly years after its ailments began, but its right third finger was permanently deformed and lacked the capability of flexion. The deformities of the humerus and the right third finger may be due to developmental osteodysplasia, a condition known in extant birds but unreported in non-avian dinosaurs before now.

Site-Specific Advantages in Skeletal Geometry and Strength at the Proximal Femur and Forearm in Young Female Gymnasts

PubMed Central

Dowthwaite, Jodi N.; Rosenbaum, Paula F.; Scerpella, Tamara A.

2012-01-01

Purpose We evaluated site-specific skeletal adaptation to loading during growth,comparing radius (RAD) and femoral neck (FN) DXA scans in young female gymnasts (GYM) and non-gymnasts (NON). Methods Subjects from an ongoing longitudinal study (8-26 yrs old) underwent annual DXA scans (proximal femur, forearm, total body) and anthropometry, completing maturity and physical activity questionnaires. This cross-sectional analysis used the most recent data meeting the following criteria: gynecological age ≤2.5 yrs post-menarche; GYM annual mean gymnastic exposure ≥5.0 h/wk in the prior year. Bone geometric and strength indices were derived from scans for 173 subjects (8-17 yrs old) via hip structural analysis (femoral narrow neck, NN) and similar radius formulae (1/3 and Ultradistal (UD)). Maturity was coded as M1 (Tanner I breast), M2 (pre-menarche, ≥Tanner II breast) or M3 (post-menarche). ANOVA and chi square compared descriptive data. Two factor ANCOVA adjusted for age, height, total body non-bone lean mass and percent body fat; significance was tested for main effects and interactions between gymnastic exposure and maturity. Results At the distal radius, GYM means were significantly greater than NON means for all variables (p<0.05). At the proximal femur, GYM exhibited narrower periosteal and endosteal dimensions, but greater indices of cortical thickness, BMC, aBMD and section modulus, with lower buckling ratio (p <0.05). However, significant interactions between maturity and loading were detected for the following: 1) FN bone mineral content (BMC), NN buckling ratio (GYM BMC advantages only in M1 and M3; for BMC and buckling ratio, M1 advantages were greatest; 2) 1/3 radius BMC, width, endosteal diameter, cortical cross-sectional area, section modulus (GYM advantages primarily post-menarche); 3) UD radius BMC and axial compressive strength (GYM advantages were larger with greater maturity, greatest post-menarche). Conclusions Maturity-specific comparisons suggested site-specific skeletal adaptation to loading during growth, with greater advantages at the radius versus the proximal femur. At the radius, GYM advantages included greater bone width, cortical cross-sectional area and cortical thickness; in contrast, at the femoral neck, GYM bone tissue cross-sectional area and cortical thickness were greater, but bone width was narrower than in NON. Future longitudinal analyses will evaluate putative maturity-specific differences. PMID:22342799

Evolutionary anatomy of the Neandertal ulna and radius in the light of the new El Sidrón sample.

PubMed

Pérez-Criado, Laura; Rosas, Antonio

2017-05-01

This paper aims to improve our understanding of the phylogenetic trait polarity related to hominin forearm evolution, in particular those traits traditionally defined as "Neandertal features." To this aim, twelve adult and adolescent fragmented forelimb elements (including ulnae and radii) of Homo neanderthalensis recovered from the site of El Sidrón (Asturias, Spain) were examined comparatively using three-dimensional geometric and traditional morphometrics. Mean centroid size and shape comparisons, principal components analysis, and phylogenetic signal analysis were undertaken. Our investigations revealed that the proximal region of the ulna discriminated best between Neandertals and modern humans, with fewer taxonomically-informative features in the distal ulna and radius. Compared to modern humans, the divergent features in the Neandertal ulna are an increase in olecranon breadth (a derived trait), lower coronoid length (primitive), and anterior orientation of the trochlear notch (primitive). In the Neandertal radius, we observe a larger neck length (primitive), medial orientation of the radial tubercle (secondarily primitive), and a curved diaphysis (secondarily primitive). Anatomically, we identified three units of evolutionary change: 1) the olecranon and its fossa, 2) the coronoid-radius neck complex, and 3) the tubercle and radial diaphysis. Based on our data, forearm evolution followed a mosaic pattern in which some features were inherited from a pre-Homo ancestor, others originated in some post-ergaster and pre-antecessor populations, and other characters emerged in the specific Homo sapiens and H. neanderthalensis lineages, sometimes appearing as secondarily primitive. Future investigations might consider the diverse phylogenetic origin of apomorphies while at the same time seeking to elucidate their functional meaning. Copyright © 2017 Elsevier Ltd. All rights reserved.

Congenital band syndrome with pseudarthrosis of the radius and ulna and impending vascular compromise: a case report.

PubMed

Ho, Christine A; Richards, B Stephens; Ezaki, Marybeth

2014-09-01

Although amniotic band syndrome is relatively rare, reports of pseudarthrosis in conjunction with amniotic band syndrome are even rarer, as are reports of impending vascular compromise in the neonatal period. Careful serial examinations and timely surgical intervention can successfully avoid the catastrophic event of limb loss. We report on a case of upper extremity amniotic band syndrome with pseudarthrosis of the radius and ulna that was complicated by vascular compromise in a neonate. Chart and radiographic data for this single case were reviewed and reported retrospectively. A 1-day-old neonate born at 28 3/7 weeks of gestational age was transferred to our institution for increased swelling to the forearm distal to a congenital band associated with an underlying radius and ulna pseudarthrosis. Although the forearm and hand were soft and viable initially, severe edema and swelling occurred after fluid resuscitation, and on the fourth day of life, the patient underwent simple band releases at bedside with 2 longitudinal incisions over the radius and ulna. Circulation was restored, and the pseudarthrosis healed with no further surgical intervention. Successful delayed reconstruction of the band with Z-plasties was performed when the baby was 7 months of age. In this case, a relatively simple, straightforward procedure that is familiar to most pediatric orthopaedists salvaged a compromised neonatal limb with amniotic band syndrome and allowed healing of a pseudarthrosis, allowing more complex reconstruction to be performed in a delayed, elective manner. Careful observation is necessary in the neonatal period of the baby with a severe band; a viable, well-perfused, compressible extremity may still be at risk.

The Radial Bow following Square Nailing in Radius and Ulna Shaft Fractures in Adults and its Relation to Disability and Function.

PubMed

Dave, M B; Parmar, K D; Sachde, B A

2016-07-01

One of the points made against nailing in radius and ulna shaft fractures has been the loss of radial bow and its impact on function. The aims of the study were to assess the change in magnitude and location of the radial bow in radius and ulna shaft fractures treated with intramedullary square nails and to assess the impact of this change on functional outcome, patient reported disability and the range of motion of the forearm. We measured the magnitude of radial bow and its location in the operated extremity and compared it to the uninjured side in 32 adult patients treated with intramedullary square nailing for radius and ulna shaft fractures at our institute. The mean loss of magnitude of maximum radial bow was 2.18 mm which was statistically significant by both student-T test and Mann-Whitney U test with p value less than 0.01. The location of maximum radial bow shifted distally but was statistically insignificant. The magnitude of maximum radial bow had a negative correlation with DASH score that was statistically insignificant (R=- 0.22, p=0.21). It had a positive, statistically significant correlation to the extent of supination in the operated extremity (R = 0.66, p = 0.0004). A loss of up to 2mm of radial bow did not influence the functional outcome as assessed by criteria reported by Anderson et al. The magnitude of radial bow influenced the supination of the forearm but not the final disability as measured by DASH score. Intramedullary nailing did decrease the magnitude of radial bow but a reduction of up to 2mm did not influence the functional outcome.

The Extended Pulsar Magnetosphere

NASA Technical Reports Server (NTRS)

Constantinos, Kalapotharakos; Demosthenes, Kazanas; Ioannis, Contopoulos

2012-01-01

We present the structure of the 3D ideal MHD pulsar magnetosphere to a radius ten times that of the light cylinder, a distance about an order of magnitude larger than any previous such numerical treatment. Its overall structure exhibits a stable, smooth, well-defined undulating current sheet which approaches the kinematic split monopole solution of Bogovalov 1999 only after a careful introduction of diffusivity even in the highest resolution simulations. It also exhibits an intriguing spiral region at the crossing of two zero charge surfaces on the current sheet, which shows a destabilizing behavior more prominent in higher resolution simulations. We discuss the possibility that this region is physically (and not numerically) unstable. Finally, we present the spiral pulsar antenna radiation pattern.

On the Rayleigh-Taylor Instability in Presence of a Background Shear

NASA Astrophysics Data System (ADS)

Shvydkoy, Roman

2018-01-01

In this note we revisit the classical subject of the Rayleigh-Taylor instability in presence of an incompressible background shear flow. We derive a formula for the essential spectral radius of the evolution group generated by the linearization near the steady state and reveal that the velocity variations neutralize shortwave instabilities. The formula is a direct generalization of the result of Hwang and Guo (Arch Ration Mech Anal 167(3):235-253, (2003). Furthermore, we construct a class of steady states which posses unstable discrete spectrum with neutral essential spectrum. The technique involves the WKB analysis of the evolution equation and contains novel compactness criterion for pseudo-differential operators on unbounded domains.

The Amsterdam wrist rules: the multicenter prospective derivation and external validation of a clinical decision rule for the use of radiography in acute wrist trauma.

PubMed

Walenkamp, Monique M J; Bentohami, Abdelali; Slaar, Annelie; Beerekamp, M Suzan H; Maas, Mario; Jager, L Cara; Sosef, Nico L; van Velde, Romuald; Ultee, Jan M; Steyerberg, Ewout W; Goslings, J Carel; Schep, Niels W L

2015-12-18

Although only 39 % of patients with wrist trauma have sustained a fracture, the majority of patients is routinely referred for radiography. The purpose of this study was to derive and externally validate a clinical decision rule that selects patients with acute wrist trauma in the Emergency Department (ED) for radiography. This multicenter prospective study consisted of three components: (1) derivation of a clinical prediction model for detecting wrist fractures in patients following wrist trauma; (2) external validation of this model; and (3) design of a clinical decision rule. The study was conducted in the EDs of five Dutch hospitals: one academic hospital (derivation cohort) and four regional hospitals (external validation cohort). We included all adult patients with acute wrist trauma. The main outcome was fracture of the wrist (distal radius, distal ulna or carpal bones) diagnosed on conventional X-rays. A total of 882 patients were analyzed; 487 in the derivation cohort and 395 in the validation cohort. We derived a clinical prediction model with eight variables: age; sex, swelling of the wrist; swelling of the anatomical snuffbox, visible deformation; distal radius tender to palpation; pain on radial deviation and painful axial compression of the thumb. The Area Under the Curve at external validation of this model was 0.81 (95 % CI: 0.77-0.85). The sensitivity and specificity of the Amsterdam Wrist Rules (AWR) in the external validation cohort were 98 % (95 % CI: 95-99 %) and 21 % (95 % CI: 15 %-28). The negative predictive value was 90 % (95 % CI: 81-99 %). The Amsterdam Wrist Rules is a clinical prediction rule with a high sensitivity and negative predictive value for fractures of the wrist. Although external validation showed low specificity and 100 % sensitivity could not be achieved, the Amsterdam Wrist Rules can provide physicians in the Emergency Department with a useful screening tool to select patients with acute wrist trauma for radiography. The upcoming implementation study will further reveal the impact of the Amsterdam Wrist Rules on the anticipated reduction of X-rays requested, missed fractures, Emergency Department waiting times and health care costs. This study was registered in the Dutch Trial Registry, reference number NTR2544 on October 1(st), 2010.

A customized protocol to assess bone quality in the metacarpal head, metacarpal shaft and distal radius: a high resolution peripheral quantitative computed tomography precision study.

PubMed

Feehan, Lynne; Buie, Helen; Li, Linda; McKay, Heather

2013-12-24

High Resolution-Peripheral Quantitative Computed Tomography (HR-pQCT) is an emerging technology for evaluation of bone quality in Rheumatoid Arthritis (RA). However, there are limitations with standard HR-pQCT imaging protocols for examination of regions of bone commonly affected in RA. We developed a customized protocol for evaluation of volumetric bone mineral density (vBMD) and microstructure at the metacarpal head (MH), metacarpal shaft (MS) and ultra-ultra-distal (UUD) radius; three sites commonly affected in RA. The purpose was to evaluate short-term measurement precision for bone density and microstructure at these sites. 12 non-RA participants, individuals likely to have no pre-existing bone damage, consented to participate [8 females, aged 23 to 71 y [median (IQR): 44 (28) y]. The custom protocol includes more comfortable/stable positioning and adapted cortical segmentation and direct transformation analysis methods. Dominant arm MH, MS and UUD radius scans were completed on day one; repeated twice (with repositioning) three to seven days later. Short-term precision for repeated measures was explored using intraclass correlational coefficient (ICC), mean coefficient of variation (CV%), root mean square coefficient of variation (RMSCV%) and least significant change (LSC%95). Bone density and microstructure precision was excellent: ICCs varied from 0.88 (MH2 trabecular number) to .99 (MS3 polar moment of inertia); CV% varied from < 1 (MS2 vBMD) to 6 (MS3 marrow space diameter); RMSCV% varied from < 1 (MH2 full bone vBMD) to 7 (MS3 marrow space diameter); and LSC%95 varied from 2 (MS2 full bone vBMD to 21 (MS3 marrow space diameter). Cortical porosity measures were the exception; RMSCV% varying from 19 (MS3) to 42 (UUD). No scans were stopped for discomfort. 5% (5/104) were repeated due to motion during imaging. 8% (8/104) of final images had motion artifact graded > 3 on 5 point scale. In our facility, this custom protocol extends the potential for in vivo HR-pQCT imaging to assess, with high precision, regional differences in bone quality at three sites commonly affected in RA. Our methods are easy to adopt and we recommend other users of HR-pQCT consider this protocol for further evaluations of its precision and feasibility in their imaging facilities.

The Effect of Isometric Massage on Global Grip Strength after Conservative Treatment of Distal Radial Fractures. Pilot Study.

PubMed

Ratajczak, Karina; Płomiński, Janusz

2015-01-01

The most common fracture of the distal end of the radius is Colles' fracture. Treatment modalities available for use in hand rehabilitation after injury include massage. The aim of this study was to evaluate the effect of isometric massage on the recovery of hand function in patients with Colles fractures. For this purpose, the strength of the finger flexors was assessed as an objective criterion for the evaluation of hand function. The study involved 40 patients, randomly divided into Group A of 20 patients and Group B of 20 patients. All patients received physical therapy and exercised individually with a physiotherapist. Isometric massage was additionally used in Group A. Global grip strength was assessed using a pneumatic force meter on the first and last day of therapy. Statistical analysis was performed using STATISTICA. Statistical significance was defined as a P value of less than 0.05. In both groups, global grip strength increased significantly after the therapy. There was no statistically significant difference between the groups. The men and women in both groups equally improved grip strength. A statistically significant difference was demonstrated between younger and older patients, with younger patients achieving greater gains in global grip strength in both groups. The incorporation of isometric massage in the rehabilitation plan of patients after a distal radial fracture did not significantly contribute to faster recovery of hand function or improve their quality of life.

Axicon based conical resonators with high power copper vapor laser.

PubMed

Singh, Bijendra; Subramaniam, V V; Daultabad, S R; Chakraborty, Ashim

2010-07-01

We report for the first time the performance of axicon based conical resonators (ABCRs) in a copper vapor laser, with novel results. The unstable conical resonator comprising of conical mirror (reflecting axicon) with axicon angle approximately pi/18, cone angle approximately 160 degrees, and a convex mirror of 60 cm radius of curvature was effective in reducing the average beam divergence to approximately 0.15 mrad (approximately 25 fold reduction compared to standard multimode plane-plane cavity) with output power of approximately 31 W. Extraction efficiency of approximately 50%-60% and beam divergence of <1 mrad was achieved in other stable ABCR configurations using flat and concave mirrors with the axicon. This is a significant improvement compared to 4-5 mrad normally observed in conventional stable resonators in copper vapor lasers. The conical resonators with copper vapor laser provide high misalignment tolerance beta approximately 4-5 mrad where beta is the tilt angle of the conical mirror from optimum position responsible for approximately 20% decline in laser power. The depth of focus d was approximately three times larger in case of conical resonator as compared to that of standard spherical unstable resonator under similar beam divergence and focusing conditions.

Electric Field Induced Interfacial Instabilities

NASA Technical Reports Server (NTRS)

Kusner, Robert E.; Min, Kyung Yang; Wu, Xiao-Lun; Onuki, Akira

1996-01-01

The study of the interface in a charge-free, nonpolar, critical and near-critical binary fluid in the presence of an externally applied electric field is presented. At sufficiently large fields, the interface between the two phases of the binary fluid should become unstable and exhibit an undulation with a predefined wavelength on the order of the capillary length. As the critical point is approached, this wavelength is reduced, potentially approaching length-scales such as the correlation length or critical nucleation radius. At this point the critical properties of the system may be affected. In zero gravity, the interface is unstable at all long wavelengths in the presence of a field applied across it. It is conjectured that this will cause the binary fluid to break up into domains small enough to be outside the instability condition. The resulting pattern formation, and the effects on the critical properties as the domains approach the correlation length are of acute interest. With direct observation, laser light scattering, and interferometry, the phenomena can be probed to gain further understanding of interfacial instabilities and the pattern formation which results, and dimensional crossover in critical systems as the critical fluctuations in a particular direction are suppressed by external forces.

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

PubMed

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

2015-01-01

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

A prospective study of pain reduction and knee dysfunction comparing femoral skeletal traction and splinting in adult trauma patients.

PubMed

Bumpass, David B; Ricci, William M; McAndrew, Christopher M; Gardner, Michael J

2015-02-01

To determine if distal femoral traction pins result in knee dysfunction in patients with femoral or pelvic fracture, and to determine if skeletal traction relieves pain more effectively than splinting for femoral shaft fractures. Prospective cohort trial. Level I urban trauma center. One hundred twenty adult patients with femoral shaft, acetabular, and unstable pelvic fractures. Patients with femoral shaft fractures were placed into distal femoral skeletal traction or a long-leg splint, based on an attending-specific protocol. Patients with pelvic or acetabular fractures with instability or intraarticular bone fragments were placed into skeletal traction. An initial Lysholm knee survey was administered to assess preinjury knee pain and function; the survey was repeated at 3- and 6-month follow-up visits. Also, a 10-point visual analog scale was used to document pain immediately before, during, and immediately after fracture immobilization with traction or splinting. Thirty-five patients (29%) were immobilized with a long-leg splint, and 85 (71%) were immobilized with a distal femoral traction pin. Eighty-four patients (70%) completed a 6-month follow-up. Lysholm scores decreased by a mean 9.3 points from preinjury baseline to 6 months postinjury in the entire cohort (P < 0.01); no significant differences were found between the splint and traction pin groups. During application of immobilization, visual analog scale pain scores were significantly lower in traction patients as compared with splinted patients (mean, 1.9 points less, P < 0.01). Traction pins caused no infections, neurovascular injuries, or iatrogenic fractures. Distal femoral skeletal traction does not result in detectable knee dysfunction at 6 months after insertion, and results in less pain during and after immobilization than long-leg splinting. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Development of a preoperative simulation technique for carotid endarterectomy in patients with contrast contraindications.

PubMed

Nomura, Shunsuke; Hayashi, Motohiro; Ishikawa, Tatsuya; Yamaguchi, Koji; Kawamata, Takakazu

2018-05-19

Vascular and osteological parameters, such as the heights of the carotid bifurcation and distal end of the plaque, are important preoperative considerations for patients undergoing carotid stenosis procedures such as carotid endarterectomy. However, for patients with contrast contraindications such as allergies or nephropathies, three-dimensional computed tomography angiography (3D-CTA) is unavailable, and preoperative evaluation remains challenging. In the present study, we aimed to develop a preoperative simulation for use in patients with contrast-contraindicated carotid stenosis. Images from non-contrast neck CT and magnetic resonance imaging obtained without the Leksell stereotactic frame were uploaded to GammaPlan. Following delineation of various structures, we performed preoperative simulations to determine the relationships between vascular and osteological structures. We applied this technique in 10 patients with carotid stenosis to verify the accuracy of the simulation. In all patients, the GammaPlan simulation successfully visualized the heights of the carotid bifurcation and distal end of the plaque without the use of contrast medium. Furthermore, information regarding the location of internal arterial structures, such as calcifications and unstable plaques, could be incorporated into GammaPlan images. Thereafter, we verified simulation accuracy by comparing the simulation results with 3D-CTA and operative findings. Simulations created using GammaPlan can be used to obtain accurate vascular and osteological information regarding the heights of the carotid bifurcation and distal end of the plaque, without the use of contrast medium. The reconstruction of delineated structures using this technique may be effective for preoperative evaluation in patients with contrast-contraindicated carotid stenosis. Copyright © 2018 Elsevier Inc. All rights reserved.

Quasi-linear gyrokinetic predictions of the Coriolis momentum pinch in NSTX

DOE Data Explorer

Guttenfelder, W. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Kaye, S. M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Ren, Y. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Solomon, W. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Bell, R. E. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Candy, J. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Gerhardt, S. P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); LeBlanc, B. P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Yuh, H. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

2016-04-01

This paper presents quasi-linear gyrokinetic predictions of the Coriolis momentum pinch for low aspect-ratio NSTX H-modes where previous experimental measurements were focused. Local, linear calculations predict that in the region of interest (just outside the mid-radius) of these relatively high-beta plasmas, profiles are most unstable to microtearing modes that are only effective in transporting electron energy. However, sub-dominant electromagnetic and electrostatic ballooning modes are also unstable, which are effective at transporting energy, particles and momentum. The quasi-linear prediction of transport from these weaker ballooning modes, assuming they contribute transport in addition to that from microtearing modes in a nonlinear turbulent state, leads to a very small or outward convection of momentum, inconsistent with the experimentally measured inward pinch, and opposite to predictions in conventional aspect ratio tokamaks. Additional predictions of a low beta L-mode plasma, unstable to more traditional electrostatic ion temperature gradient-trapped electron mode instability, show that the Coriolis pinch is inward but remains relatively weak and insensitive to many parameter variations. The weak or outward pinch predicted in NSTX plasmas appears to be at least partially correlated to changes in the parallel mode structure that occur at finite beta and low aspect ratio, as discussed in previous theories. The only conditions identified where a stronger inward pinch is predicted occur either in the purely electrostatic limit or if the aspect ratio is increased. As the Coriolis pinch cannot explain the measured momentum pinch, additional theoretical momentum transport mechanisms are discussed that may be potentially important.

Giant cell tumour 2nd metatarsal-Result with en-bloc excision and autologous fibular grafting.

PubMed

Agarwal, Saurabh; Chawla, Sumit; Agarwal, Sippy; Agarwal, Puneet

2015-12-01

Giant cell tumour (GCT) of the small bones is relatively uncommon tumour. It occurs most commonly in the distal portions of femur and radius and proximal end of tibia. GCT of small bones presents at advanced stages with major bony destruction. These tumours represent more aggressive course; associated with increased local recurrence rates (40%) and metastasis. Various treatment modalities like en-bloc resection, cryosurgery, intralesional curettage with burring/phenolization or bone cement are available. In our case en-bloc resection with reconstruction using nonvascular autogenous fibular strut graft was used in patient of 2nd metatarsal GCT and a favourable functional outcome was observed. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Injury patterns and prophylaxis in inline skating].

PubMed

Jerosch, J; Heck, C

2005-05-01

Inline skating has become one of the fastest growing sports since its appearance in 1980. The increasing number of inline skaters has also led to a rising incidence of injuries. The most common injury is the distal fracture of the radius, which occurs in 50% of all fractures. There are several reasons for increasing serious injuries in inline skating. The majority of skaters do not wear proper protective equipment (helmet, elbow, knee and wrist protectors), however, many users can not handle their inline skates in dangerous situations. All skaters should take care by buying industrially tested inline skates and appropriate protective equipment; novice skaters should additionally attend special skating schools to learn skating, braking and the the correct falling techniques.

Oscillation Characteristics of Thermocapillary Convection in An Open Annular Pool

NASA Astrophysics Data System (ADS)

Duan, Li; Kang, Qi; Zhang, Di

2016-07-01

Temperature oscillation characteristics and free surface deformation are essential phenomena in fluids with free surface. We report experimental oscillatory behaviors for hydrothermal wave instability in thermocapillary-driven flow in an open annular pool of silicone oil. The annular pool is heated from the inner cylindrical wall with the radius 4mm and cooled at the outer wall with radius 20mm, and the depth of the silicone oil layer is in the range of 0.8mm-3mm.Temperature difference between the two sidewalls was increased gradually, and the flow will become unstable via a super critical temperature difference. In the present paper we used T-type thermocouple measuring the single-point temperature inside the liquid layer and captured the tiny micrometer wave signal through a high-precision laser displacement sensor. The critical temperature difference and critical Ma number of onset of oscillation have been obtained. We discussed the critical temperature difference and critical Marangoni number varies with the change of the depth of liquid layer, and the relationship between the temperature oscillation and surface oscillation has been discussed. Experimental results show that temperature oscillation and surface oscillation start almost at the same time with similar spectrum characteristic.

Parametric instability of shaft with discs

NASA Astrophysics Data System (ADS)

Wahab, A. M. Abdul; Rasid, Z. A.; Abu, A.; Rudin, N. F. Mohd Noor

2017-12-01

The occurrence of resonance is a major criterion to be considered in the design of shaft. While force resonance occurs merely when the natural frequency of the rotor system equals speed of the shaft, parametric resonance or parametric instability can occur at excitation speed that is integral or sub-multiple of the frequency of the rotor. This makes the study on parametric resonance crucial. Parametric instability of a shaft system consisting of a shaft and disks has been investigated in this study. The finite element formulation of the Mathieu-Hill equation that represents the parametric instability problem of the shaft is developed based on Timoshenko’s beam theory and Nelson’s finite element method (FEM) model that considers the effect of torsional motion on such problem. The Bolotin’s method is used to determine the regions of instability and the Strut-Ince diagram. The validation works show that the results of this study are in close agreement to past results. It is found that a larger radius of disk will cause the shaft to become more unstable compared to smaller radius although both weights are similar. Furthermore, the effect of torsional motion on the parametric instability of the shaft is significant at higher rotating speed.

Evaluation of the detachment energy of hydrated phosphate anion over a wide range of cluster size and revisiting solvent-berg model: a theoretical study

NASA Astrophysics Data System (ADS)

Pathak, Arup Kumar

2014-12-01

An explicit analytical expression has been obtained for vertical detachment energy (VDE) that can be used to calculate the same over a wide range (both stable and unstable regions) of cluster sizes including the bulk from the knowledge of VDE for a finite number of stable clusters (n = 16-23). The calculated VDE for the bulk is found to be very good in agreement (within 1%) with the available experimental result and the domain of instability lies between n = 0 and n = 15 for the hydrated clusters, PO3 -4 . nH2O. The minimum number (n0) of water molecules needed to stabilise the phosphate anion is 16. We are able to explain the origin of solvent-berg model and anomalous conductivity from the knowledge of first stable cluster. We have also provided a scheme to calculate the radius of the solvent-berg for phosphate anion. The calculated conductivity using Stokes-Einstein relation and the radius of solvent-berg is found to be very good in agreement (within 4%) with the available experimental results.

Dynamics of the axisymmetric core-annular flow. II. The less viscous fluid in the core, saw tooth waves

NASA Astrophysics Data System (ADS)

Kouris, Charalampos; Tsamopoulos, John

2002-03-01

The nonlinear dynamics of the concentric, two-phase flow of two immiscible fluids in a circular tube is studied when the viscosity ratio of the fluid in the annulus to that in the core of the tube, μ, is larger than or equal to unity. For these values of the viscosity ratio the perfect core-annular flow (CAF) is linearly unstable and it is necessary to keep the ratio of the thickness of the annulus to the radius of the tube small so that the solutions remain uniformly bounded. The simulations are based on a pseudospectral numerical method while special care has been taken in order to minimize as far as possible the effect of the boundary conditions imposed in the axial direction allowing for multiple waves of different lengths to develop and interact. The time integration originates with the analytical solution for the pressure driven, perfect CAF or the perfect CAF seeded with either the most unstable mode or random disturbances. Quite regular wave patterns are predicted in the first two cases, whereas multiple unstable modes grow and remain even after saturation of the instability in the last case. The resulting waves generally travel in the same direction and faster than the undisturbed interface, except for the case with μ=1 for which they are stationary with respect to it. Depending on parameter values, waves move with the same velocity or interact with each other exchanging their amplitudes or merge and split giving rise to either chaotic or organized solutions. For fluids of equal viscosities and densities (μ=ρ=1) and for a Reynolds number, Re(≡Λρ̂1R̂2Ŵ0/μ̂1)=0.0275 and an inverse Weber number, W(≡T̂/(ρ̂1Ŵ02R̂2))=145.4, both based on the properties of the inner fluid, the tube radius, R̂2, and the average flow velocity, Ŵ0, small amplitude waves are predicted. The increase of μ by almost two orders of magnitude does not affect their amplitudes, but increases their temporal period linearly. Varying W by more than three orders of magnitude increases their amplitudes proportionately, while their period increases with the logarithm of W. Similar to that is the effect of increasing Re. The present analysis confirms and extends results based on long wave expansions, which lead to the Kuramoto-Sivashinsky equation and modifications of it.

Adaptive control based on retrospective cost optimization

NASA Technical Reports Server (NTRS)

Bernstein, Dennis S. (Inventor); Santillo, Mario A. (Inventor)

2012-01-01

A discrete-time adaptive control law for stabilization, command following, and disturbance rejection that is effective for systems that are unstable, MIMO, and/or nonminimum phase. The adaptive control algorithm includes guidelines concerning the modeling information needed for implementation. This information includes the relative degree, the first nonzero Markov parameter, and the nonminimum-phase zeros. Except when the plant has nonminimum-phase zeros whose absolute value is less than the plant's spectral radius, the required zero information can be approximated by a sufficient number of Markov parameters. No additional information about the poles or zeros need be known. Numerical examples are presented to illustrate the algorithm's effectiveness in handling systems with errors in the required modeling data, unknown latency, sensor noise, and saturation.

A Wolff in sheep's clothing: trabecular bone adaptation in response to changes in joint loading orientation.

PubMed

Barak, Meir M; Lieberman, Daniel E; Hublin, Jean-Jacques

2011-12-01

This study tests Wolff's law of trabecular bone adaptation by examining if induced changes in joint loading orientation cause corresponding adjustments in trabecular orientation. Two groups of sheep were exercised at a trot, 15 min/day for 34 days on an inclined (7°) or level (0°) treadmills. Incline trotting caused the sheep to extend their tarsal joints by 3-4.5° during peak loading (P<0.01) but has no effect on carpal joint angle (P=0.984). Additionally, tarsal joint angle in the incline group sheep were maintained more extended throughout the day using elevated platform shoes on their forelimbs. A third "sedentary group" group did not run but wore platform shoes throughout the day. As predicted by Wolff's law, trabecular orientation in the distal tibia (tarsal joint) were more obtuse by 2.7 to 4.3° in the incline group compared to the level group; trabecular orientation was not significantly different in the sedentary and level groups. In addition, trabecular orientations in the distal radius (carpal joint) of the sedentary, level and incline groups did not differ between groups, and were aligned almost parallel to the radius long axis, corresponding to the almost straight carpal joint angle at peak loading. Measurements of other trabecular bone parameters revealed additional responses to loading, including significantly higher bone volume fraction (BV/TV), Trabecular number (Tb.N) and trabecular thickness (Tb.Th), lower trabecular spacing (Tb.Sp), and less rod-shaped trabeculae (higher structure model index, SMI) in the exercised than sedentary sheep. Overall, these results demonstrate that trabecular bone dynamically adjusts and realigns itself in very precise relation to changes in peak loading direction, indicating that Wolff's law is not only accurate but also highly sensitive. Copyright © 2011 Elsevier Inc. All rights reserved.

[Reconstruction of the extensor pollicis longus tendon by transposition of the extensor indicis tendon].

PubMed

Loos, A; Kalb, K; Van Schoonhoven, J; Landsleitner Dagger, B

2003-12-01

Rupture of the extensor pollicis longus-tendon (EPL) is a frequent complication after distal radius fractures. Other traumatic and non-traumatic reasons for this tendon lesion are known, including a theory about a disorder in the blood supply to the tendon itself. We examined 40 patients after reconstruction of the EPL-tendon in a mean follow-up time of 30 months. All patients were clinically examined and a DASH questionnaire was answered by all patients. The method to reconstruct the EPL-tendon was the transposition of the extensor indicis-tendon. After the operations the thumb was put in a splint for four weeks in a "hitch-hiker's-position". 31 ruptures of the tendon (77.5 %) were a result of trauma. In 20 of them (50 %) a distal radius fracture had occurred. Clinical examination included measurements of the movement of the thumb- and index-finger joints, the grip strength and the maximal span of the hand. Significant differences were not found. The isolated extension of the index finger was possible in all patients. But it was reduced in ten cases which represent 25 %. Our results were evaluated by the Geldmacher score to evaluate the reconstruction of the EPL-tendon. 20 % excellent, 65 % good, 12.5 % fair and 2.5 % poor results were reached. The Geldmacher score was used critically. We suggest its modification for the evaluation of thumb abduction. The DASH score reached a functional value of ten points which represents a very good result. In conclusion the extensor indicis-transposition is a safe method to reconstruct the EPL-tendon. Its substantial advantage is taking a healthy muscle as the motor, thereby avoiding the risk of using a degenerated muscle in late tendon reconstruction. A powerful extension of the index finger will be maintained by physical education. Generally, the loss of the extension of the index finger is negligible. It does not disturb the patients. But it has to be discussed with the patient before the operation.

Early diagnosis of osteoporosis using radiogrammetry and texture analysis from hand and wrist radiographs in Indian population.

PubMed

Areeckal, A S; Jayasheelan, N; Kamath, J; Zawadynski, S; Kocher, M; David S, S

2018-03-01

We propose an automated low cost tool for early diagnosis of onset of osteoporosis using cortical radiogrammetry and cancellous texture analysis from hand and wrist radiographs. The trained classifier model gives a good performance accuracy in classifying between healthy and low bone mass subjects. We propose a low cost automated diagnostic tool for early diagnosis of reduction in bone mass using cortical radiogrammetry and cancellous texture analysis of hand and wrist radiographs. Reduction in bone mass could lead to osteoporosis, a disease observed to be increasingly occurring at a younger age in recent times. Dual X-ray absorptiometry (DXA), currently used in clinical practice, is expensive and available only in urban areas in India. Therefore, there is a need to develop a low cost diagnostic tool in order to facilitate large-scale screening of people for early diagnosis of osteoporosis at primary health centers. Cortical radiogrammetry from third metacarpal bone shaft and cancellous texture analysis from distal radius are used to detect low bone mass. Cortical bone indices and cancellous features using Gray Level Run Length Matrices and Laws' masks are extracted. A neural network classifier is trained using these features to classify healthy subjects and subjects having low bone mass. In our pilot study, the proposed segmentation method shows 89.9 and 93.5% accuracy in detecting third metacarpal bone shaft and distal radius ROI, respectively. The trained classifier shows training accuracy of 94.3% and test accuracy of 88.5%. An automated diagnostic technique for early diagnosis of onset of osteoporosis is developed using cortical radiogrammetric measurements and cancellous texture analysis of hand and wrist radiographs. The work shows that a combination of cortical and cancellous features improves the diagnostic ability and is a promising low cost tool for early diagnosis of increased risk of osteoporosis.

[Anatomy study on micro transverse flap pedicled with superfical palmar branch of radial artery from palmar wrist].

PubMed

Zhao, Min; Tian, Dehu; Shao, Xinzhong; Li, Dacun; Li, Jianfeng; Liu, Jingda; Zhao, Liang; Li, Hailei; Wang, Xiaolei; Zhang, Wentong; Wu, Jinying; Yuan, Zuoxiong

2013-07-01

To study the anatomical basis of micro transverse flap pedicled with the superfical palmar branch of radial artery from the palmar wrist for using this free flap to repair soft tissue defect of the finger. Thirty-eight fresh upper limb specimens (22 males and 16 females; aged 26-72 years with an average of 36 years; at left and right sides in 19 limbs respectively) were dissected and observed under operating microscope. Two specimens were made into casting mould of artery with bones, and 2 specimens were injected with red emulsion in radial artery. Thirty-four specimens were injected with 1% gentian violet solution in the superfical palmar branch of the radial artery. A transverse oval flap in the palmar wrist was designed, the axis of the flap was the distal palmar crease. The origin, distribution, and anastomosis of the superfical palmar branch of the radial artery were observed. The superficial palmar branch of the radial artery was constantly existed, it usually arises from the main trunk of the radial artery, 1.09-3.60 cm to proximal styloid process of radius. There were about 2-5 branches between the origin and the tubercle of scaphoid bone. The origin diameter was 1.00-3.00 mm, and the distal diameter at the styloid process of radius was 1.00-2.90 mm. The venous return of flap passed through 2 routes, and the innervations of the flap mainly from the palmar cutaneous branch of the median nerve. The area of the flap was 4 cm x 2 cm-6 cm x 2 cm. The origin and courses of the superficial palmar branch of the radial artery is constant, and its diameter is similar to that of the digital artery. A transverse oval flap pedicled with the superfical palmar branch of radial artery in the palmar wrist can be designed to repair defects of the finger.

Late effect of subtotal thyroidectomy and radioactive iodine therapy on calcitonin secretion and bone mineral density in women treated for Graves' disease

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

Lowery, W.D.; Thomas, C.G. Jr.; Awbrey, B.J.

1986-12-01

This study was designed to evaluate the effect of subtotal thyroidectomy and/or radioactive iodine therapy on plasma immunocalcitonin (iCT) levels and bone densities in patients treated for Graves' disease. Forty-eight women whose ages ranged from 29 to 79 years (mean, 55 years) were evaluated. All were at least 10 years beyond treatment. Fourteen patients had undergone subtotal thyroidectomy, 22 had received radioactive iodine therapy, and 12 had received both. Serum calcitonin levels were measured with the patient fasting and at 30 minutes and 2 hours after the ingestion of 15 mg of calcium in orange juice. Single photon absorptiometry wasmore » used to measure bone mineral density of the middle and distal radius. The mean fasting plasma levels of iCT for patients undergoing subtotal thyroidectomy was 27 +/- 2 mumol/L; women treated with radioactive iodine, 26 +/- 2; women undergoing subtotal thyroidectomy followed by radioactive iodine, 24 +/- 2, and for normal control women, 48.5 +/- 4.7. The mean stimulated iCT level of each of the patient groups was significantly lower than that of the normal controls (p = 0.01). There were no significant differences among the groups. Although there was an increased loss of bone mineral density in postmenopausal patients, with age and race as covariates, the bone densities of the distal radius in women undergoing subtotal thyroidectomy and/or receiving radioactive iodine were not significantly lower than those of normal control subjects (p greater than 0.05). These findings are consistent with other observations that patients treated by thyroidectomy and/or radioactive iodine for Graves' disease have lower basal levels of calcitonin and decreased calcitonin response to a provocative stimulus. Whether this loss of calcitonin reserve is a significant factor in development of postmenopausal osteoporosis remains unanswered.« less

Why the chameleon has spiral-shaped muscle fibres in its tongue

PubMed Central

Leeuwen, J. L. van

1997-01-01

The intralingual accelerator muscle is the primary actuator for the remarkable ballistic tongue projection of the chameleon. At rest, this muscle envelopes the elongated entoglossal process, a cylindrically shaped bone with a tapering distal end. During tongue projection, the accelerator muscle elongates and slides forward along the entoglossal process until the entire muscle extends beyond the distal end of the process. The accelerator muscle fibres are arranged in transverse planes (small deviations are possible), and form (hitherto unexplained) spiral-shaped arcs from the peripheral to the internal boundary. To initiate tongue projection, the muscle fibres probably generate a high intramuscular pressure. The resulting negative pressure gradient (from base to tip) causes the muscle to elongate and to accelerate forward. Effective forward sliding is made possible by a lubricant and a relatively low normal stress exerted on the proximal cylindrical part of the entoglossal process. A relatively high normal stress is, however, probably required for an effective acceleration of muscle tissue over the tapered end of the process. For optimal performance, the fast extension movement should occur without significant (energy absorbing) torsional motion of the tongue. In addition, the tongue extension movement is aided by a close packing of the muscles fibres (required for a high power density) and a uniform strain and work output in every cross-section of the muscle. A quantitative model of the accelerator muscle was developed that predicts internal muscle fibre arrangements based on the functional requirements above and the physical principle of mechanical stability. The curved shapes and orientations of the muscle fibres typically found in the accelerator muscle were accurately predicted by the model. Furthermore, the model predicts that the reduction of the entoglossal radius towards the tip (and thus the internal radius of the muscle) tends to increase the normal stress on the entoglossal bone.

Sun Exposure Behavior, Seasonal Vitamin D Deficiency, and Relationship to Bone Health in Adolescents.

PubMed

Farrar, Mark D; Mughal, M Zulf; Adams, Judith E; Wilkinson, Jack; Berry, Jacqueline L; Edwards, Lisa; Kift, Richard; Marjanovic, Elizabeth; Vail, Andy; Webb, Ann R; Rhodes, Lesley E

2016-08-01

Vitamin D is essential for bone health in adolescence, when there is rapid bone mineral content accrual. Because cutaneous sun exposure provides vitamin D, there is no recommended oral intake for UK adolescents. Our objective was to assess seasonal vitamin D status and its contributors in white Caucasian adolescents and examine bone health in those found deficient. Prospective cohort study was undertaken. Six schools in Greater Manchester, UK, were included. Participants were 131 adolescents between 12 and 15 years of age. Seasonal assessment of circulating 25-hydroxyvitamin D (25OHD), personal sun exposure, and dietary vitamin D. Adolescents deficient (25OHD <10 ng/ml/25 nmol/liter) in at least one season underwent dual-energy X-ray absorptiometry (lumbar spine, femoral neck), with bone mineral apparent density correction for size, and peripheral quantitative computed tomography (distal radius) for volumetric bone mineral density (BMD). Serum 25OHD and BMD measurements. Mean 25OHD was highest in September: 24.1 (SD, 6.9) ng/ml and lowest in January: 15.5 (5.9) ng/ml. Over the year, 16% were deficient in ≥ one season and 79% insufficient (25OHD <20 ng/ml/50 nmol/liter) including 28% in September. Dietary vitamin D was low year-round, whereas personal sun exposure was seasonal and predominantly across the school week. Holidays accounted for 17% variation in peak 25OHD (P < .001). Nineteen adolescents underwent bone assessment, which showed low femoral neck bone mineral apparent density vs matched reference data (P = .0002), three with Z less than or equal to -2.0 distal radius trabecular volumetric BMD. Sun exposure levels failed to provide adequate vitamin D, with approximately one-quarter of adolescents insufficient even at summer peak. Seasonal vitamin D deficiency was prevalent and those affected had low BMD. Recommendations on vitamin D acquisition are indicated in this age-group.

Use of MR-based trabecular bone microstructure analysis at the distal radius for osteoporosis diagnostics: a study in post-menopausal women with breast cancer and treated with aromatase inhibitor.

PubMed

Baum, Thomas; Karampinos, Dimitrios C; Seifert-Klauss, Vanadin; Pencheva, Tsvetelina D; Jungmann, Pia M; Rummeny, Ernst J; Müller, Dirk; Bauer, Jan S

2016-01-01

Treatment with aromatase inhibitor (AI) is recommended for post-menopausal women with hormone-receptor positive breast cancer. However, AI therapy is known to induce bone loss leading to osteoporosis with an increased risk for fragility fractures. The purpose of this study was to investigate whether changes of magnetic resonance (MR)-based trabecular bone microstructure parameters as advanced imaging biomarker can already be detected in subjects with AI intake but still without evidence for osteoporosis according to dual energy X-ray absorptiometry (DXA)-based bone mineral density (BMD) measurements as current clinical gold standard. Twenty-one postmenopausal women (62±6 years of age) with hormone-receptor positive breast cancer, ongoing treatment with aromatase inhibitor for 23±15 months, and no evidence for osteoporosis (current DXA T-score greater than -2.5) were recruited for this study. Eight young, healthy women (24±2 years of age) were included as controls. All subjects underwent 3 Tesla magnetic resonance imaging (MRI) of the distal radius to assess the trabecular bone microstructure. Trabecular bone microstructure parameters were not significantly (p>0.05) different between subjects with AI intake and controls, including apparent bone fraction (0.42±0.03 vs. 0.42±0.05), trabecular number (1.95±0.10 mm(-1) vs 1.89±0.15 mm(-1)), trabecular separation (0.30±0.03 mm vs 0.31±0.06 mm), trabecular thickness (0.21±0.01 mm vs 0.22±0.02 mm), and fractal dimension (1.70±0.02 vs. 1.70±0.03). These findings suggest that the initial deterioration of trabecular bone microstructure as measured by MRI and BMD loss as measured by DXA occur not sequentially but rather simultaneously. Thus, the use of MR-based trabecular bone microstructure assessment is limited as early diagnostic biomarker in this clinical setting.

Bone microstructure in men assessed by HR-pQCT: Associations with risk factors and differences between men with normal, low, and osteoporosis-range areal BMD.

PubMed

Okazaki, Narihiro; Burghardt, Andrew J; Chiba, Ko; Schafer, Anne L; Majumdar, Sharmila

2016-12-01

The primary objective of this study was to analyze the relationships between bone microstructure and strength, and male osteoporosis risk factors including age, body mass index, serum 25-hydroxyvitamin D level, and testosterone level. A secondary objective was to compare microstructural and strength parameters between men with normal, low, and osteoporosis-range areal bone mineral density (aBMD). Seventy-eight healthy male volunteers (mean age 62.4 ± 7.8 years, range 50-84 years) were recruited. The participants underwent dual-energy X-ray absorptiometry (DXA) and high-resolution peripheral quantitative computed tomography (HR-pQCT) of the ultra-distal radius and tibia. From the HR-pQCT images, volumetric bone mineral density (BMD) and cortical and trabecular bone microstructure were evaluated, and bone strength and cortical load fraction (Ct.LF) were estimated using micro-finite element analysis (μFEA). Age was more strongly correlated with bone microstructure than other risk factors. Age had significant positive correlations with cortical porosity at both ultra-distal radius and tibia ( r  = 0.36, p  = 0.001, and r  = 0.47, p  < 0.001, respectively). At the tibia, age was negatively correlated with cortical BMD, whereas it was positively correlated with trabecular BMD. In μFEA, age was negatively correlated with Ct.LF, although not with bone strength. Compared with men with normal aBMD, men with low or osteoporosis-range aBMD had significantly poor trabecular bone microstructure and lower bone strength at the both sites, while there was no significant difference in cortical bone. Cortical bone microstructure was negatively affected by aging, and there was a suggestion that the influence of aging may be particularly important at the weight-bearing sites.

Magnetic-field-induced dose effects in MR-guided radiotherapy systems: dependence on the magnetic field strength.

PubMed

Raaijmakers, A J E; Raaymakers, B W; Lagendijk, J J W

2008-02-21

Several institutes are currently working on the development of a radiotherapy treatment system with online MR imaging (MRI) modality. The main difference between their designs is the magnetic field strength of the MRI system. While we have chosen a 1.5 Tesla (T) magnetic field strength, the Cross Cancer Institute in Edmonton will be using a 0.2 T MRI scanner and the company Viewray aims to use 0.3 T. The magnetic field strength will affect the severity of magnetic field dose effects, such as the electron return effect (ERE): considerable dose increase at tissue air boundaries due to returning electrons. This paper has investigated how the ERE dose increase depends on the magnetic field strength. Therefore, four situations where the ERE occurs have been simulated: ERE at the distal side of the beam, the lateral ERE, ERE in cylindrical air cavities and ERE in the lungs. The magnetic field comparison values were 0.2, 0.75, 1.5 and 3 T. Results show that, in general, magnetic field dose effects are reduced at lower magnetic field strengths. At the distal side, the ERE dose increase is largest for B = 0.75 T and depends on the irradiation field size for B = 0.2 T. The lateral ERE is strongest for B = 3 T but shows no effect for B = 0.2 T. Around cylindrical air cavities, dose inhomogeneities disappear if the radius of the cavity becomes small relative to the in-air radius of the secondary electron trajectories. At larger cavities (r > 1 cm), dose inhomogeneities exist for all magnetic field strengths. In water-lung-water phantoms, the ERE dose increase takes place at the water-lung transition and the dose decreases at the lung-water transition, but these effects are minimal for B = 0.2 T. These results will contribute to evaluating the trade-off between magnetic field dose effects and image quality of MR-guided radiotherapy systems.

Variation in the Incidence of Distal Radius Fractures in the US Elderly as Related to Slippery Weather Conditions

PubMed Central

Giladi, Aviram M.; Shauver, Melissa J.; Ho, Allison; Zhong, Lin; Kim, H. Myra; Chung, Kevin C.

2014-01-01

Background Distal radius fractures (DRFs) are costly and debilitating injuries, especially for the elderly. DRFs often occur from falls and more commonly occur outdoors. Inclement weather, especially in the winter, may increase the risk of fall-related injuries. Small community studies have reported increased risk of DRF due to inclement winter weather; however, larger studies are lacking. Methods We analyzed a sample of 2007 Medicare claims for DRF. Weather data were collected for the date and location of each DRF in our analysis cohort. A novel slipperiness score (0–7, 7 indicates the most slippery weather) was used as a measure of the severity of slippery outdoor conditions. Negative binomial regression models evaluated the correlation between slipperiness and DRF occurrence. Results Risk of DRF was higher in winter months (Incidence Rate Ratio=1.2, 95%CI 1.14–1.26, p<0.001). Days with average temperature ≤ 32°F (IRR=1.36, 95%CI 1.19–1.54, p<0.001), snow/ice on ground at the start of the day (IRR=1.45, 95%CI 1.25–1.68, p<0.001), and freezing rain (IRR=1.24, 95%CI 1.03–1.49, p=0.025) all had an increased risk of DRF. Risk of sustaining a DRF was increased 21% on days with a slipperiness score of 5 or above (IRR=1.21, 95%CI 1.08–1.20, p=0.007). Additionally, for each increase in slipperiness score above 4, the IRR of DRF increased as well. Conclusions Weather events that create slippery walking conditions, most often occurring in winter months, result in an increased risk of DRF in the US elderly. This finding can be used to support resource allocation as well as awareness and prevention campaigns. Level of Evidence IV; retrospective cohort PMID:24469166

[Ligamentous injuries to the ankle joint].

PubMed

Rammelt, S; Schneiders, W; Grass, R; Rein, S; Zwipp, H

2011-10-01

Injuries to the lateral ankle ligaments are the most common sports injuries. Determination of their severity and exclusion of relevant accompanying injuries requires a subtle clinical and a focussed radiological assessment. Treatment is non-operative and functional in the majority of cases. Consequent application of orthoses limiting supination and proprioceptive training are essential to avoid chronic instability. With recurrent ankle sprains one has to distinguish between functional and mechanical instability. The latter can be treated successfully with anatomic reconstruction and ligamentoplasty in more than 80 % of cases. Extraanatomic tenodeses should be reserved for cases of combined ankle and subtalar instability. Isolated injuries to the medial collateral ligaments are rare. Therefore, osseous injuries or underlying deformities have to be excluded. Isolated deltoid ligament ruptures may be treated non-operatively. Unstable injuries to the distal tibiofibular syndesmosis resulting in a manifest or latent diastasis are treated with open reduction and fixation with two tibiofibular set screws. Anatomic reduction of the distal fibula into the tibial groove is of utmost prognostic relevance and therefore should be reliably proved with either intraoperative 3D fluoroscopy or postoperative CT scanning. For chronic syndesmotic instability an anatomic ligamentoplasty using half the peroneus longus tendon is recommended. © Georg Thieme Verlag KG Stuttgart · New York.

Finite element analysis on preferable I-bar clasp shape.

PubMed

Sato, Y; Tsuga, K; Abe, Y; Asahara, S; Akagawa, Y

2001-05-01

An I-bar clasp is one of the most popular direct retainers for distal-extension removable partial dentures. However, no adequate information is available on preferable shape as determined by biomechanics. This study aimed (1) to investigate, by finite element analysis (FEA), the dimensions and stress of I-bar clasps having the same stiffness, and (2) to estimate a mechanically preferable clasp design. Three-dimensional FEA models of I-bar clasps were created with vertical and horizontal straight sections connected by a curved section characterized by six parameters: thickness of the clasp tip, width of the clasp tip, radius of the curvature, horizontal distance between the base and the vertical axis, vertical dimension between the tip and the horizontal axis, and taper (change of width per unit length along the axis). Stress was calculated with a concentrated load of 5 N applied 2 mm from the tip of the clasp in the buccal direction. A thinner and wider clasp having an taper of 0.020-0.023 and radius of curvature of 2.75-3.00 showed less stress. The results suggest that such a shape might be the preferable I-bar clasp shape as biomechanical viewpoint.

Phase behavior and kinetics of phase separation of a nonionic microemulsion of C12E5/water/1-chlorotetradecane upon a temperature quench.

PubMed

Roshan Deen, G; Oliveira, Cristiano L P; Pedersen, Jan Skov

2009-05-21

The phase behavior and phase separation kinetics of a model ternary nonionic microemulsion system composed of pentaethylene glycol dodecyl ether (C12E5), water, and 1-chlorotetradecane were studied. With increasing temperature, the microemulsion exhibits the following rich phase behavior: oil-in-water phase (L1+O), droplet microemulsion phase (L1), lamellar liquid crystalline phase (Lproportional), and sponge-like (liquid) phase (L3). The microemulsion with a fixed surfactant-to-oil volume fraction ratio (Phis/Phio) of 0.81 and droplet volume fraction of 0.087 was perturbed from equilibrium by a temperature quench from the L1 region (24 degrees C) to an unstable region L1+O (13 degrees C), where the excess oil phase is in equilibrium with the microemulsion droplets. The process of phase separation in the unstable region was followed by time-resolved small-angle X-ray scattering (TR-SAXS) and time-resolved turbidity methods. Due to the large range of scattering vector (q=0.004-0.22 A(-1)) that is possible to access with the TR-SAXS method, the growth of the oil droplets and shrinking of the microemulsion droplets as a result of phase separation could be studied simultaneously. By using an advanced polydisperse ellipsoidal hard-sphere model, the experimental curves have been quantitatively analyzed. The microemulsion droplets were modeled as polydisperse core-shell ellipsoidal particles, using molecular constraints, and the oil droplets are modeled as polydisperse spheres. The radius of gyration (Rg) of the growing oil droplets, volume fraction of oil in the microemulsion droplets, and polydispersity were obtained from the fit parameters. The volume equivalent radius at the neutral plane between the surfactant head and tail of the microemulsion droplet decreased from 76 to 51 A, while the radius of oil drop increased to 217 A within the 160 min of the experiment. After about 48 min from the temperature quench, the system reaches a steady state and continues to coarsen at a constant fraction of the oil of 0.51 in the oil phase by Ostwald ripening with the power law dependence of Roil proportional, variant t1/3. The size of the oil droplets determined by the time-resolved turbidity method is in good agreement with that of the TR-SAXS, highlighting the usefulness of the method in the size determination of oil-in-water microemulsions on an absolute scale.