Jeffrey P. Schwab

The necessity of acute bone grafting in diaphyseal forearm fractures : A Retrospective review

OBJECTIVE To determine the union rate of forearm fractures where acute bone grafting was recommended but not performed. DESIGN Retrospective review. SETTING Regional level one trauma center. PATIENTS The criteria for inclusion in the study were patients with closed growth plates and a diaphyseal fracture of the radius, ulna, or both (including Monteggia and Galeazzi fracture-dislocations) that were treated with plate fixation. Patients were excluded from the study if they were lost to follow-up before radiographic documentation of bone union. The review identified 198 fractures that were eligible for inclusion. Fifteen fractures were excluded. INTERVENTION The method of treatment of each fracture was open reduction and plate fixation with or without bone grafting. MAIN OUTCOME MEASUREMENT Fracture union. RESULTS The overall union rate in comminuted, nongrafted forearm fractures (open and closed) was 98% (99/101; 95% confidence interval: 93-100%). The union rate in closed, comminuted, nongrafted forearm fractures was 97% (74/76; 95% confidence interval; 91-100%). CONCLUSIONS Open reduction and internal fixation of comminuted diaphyseal forearm fractures without bone grafting in this study produced union rates comparable to those reported for open reduction and internal fixation of comminuted forearm fractures with acute bone grafting. This study suggests that routine use of bone grafting in comminuted forearm fractures is not indicated.

A murine model of deep vein thrombosis Characterization and validation in transgenic mice

Deep vein thrombosis (DVT) occurs with high prevalence in association with a number of risk factors, including major surgery, trauma, obesity, bed rest (> 5 days), cancer, a previous history of DVT, and several predisposing prothrombotic mutations. A novel murine model of DVT was developed for applications to preclinical studies of transgenically constructed prothrombotic lines and evaluation of new antithrombotic therapies.A transient direct-current electrical injury was induced in the common femoral vein of adult C57BI/6 mice. A non-occlusive thrombus grew, peaking in size at 30 min, and regressing by 60 min, as revealed by histomorphometric volume reconstruction of the clot. Pre-heparinization greatly reduced clot formation at 10, 30, and 60 min (p < 0.01 versus non-heparinized). Homozygous FactorV Leiden mice (analogous to the clinical FactorV Leiden prothrombotic mutation) on a C57Bl/6 background had clot volumes more than twice those of wild-types at 30 min (0.121 +/- 0.018 mm3 vs. 0.052 +/- 0.008 mm3, respectively; p < 0.01). Scanning electron microscopy revealed a clot surface dominated by fibrin strands, in contrast to arterial thrombi which showed a platelet-dominated structure. This new model of DVT presents a quantifiable approach for evaluating thrombosis-related murine transgenic lines and for comparatively evaluating new pharmacologic approaches for prevention of DVT.

The use of Ender nails in fractures of the tibial shaft.

Between November 1979 and January 1983, we treated fifty-one severe fractures of the tibial shaft with multiple intramedullary Ender nails. Thirty-six fractures were treated within two weeks after injury. Forty-one fractures united in less than four months and eight, in four to eight months. Only two were not united after eight months. An anatomical reduction was maintained in all but three of the fractures, in which the tibia shortened. Two tibiae united with an angulation of 7 degrees and one with 6 degrees, as measured in two planes. There were two infections, both after an open fracture. It has been our experience that Ender nails provide excellent rotational stability, allow early full weight-bearing, and markedly decrease the duration of need for immobilization. Ender nailing was of value both for the acute management of complicated high-energy fractures of the tibial shaft with extensive soft-tissue damage and as a salvage procedure to maintain reduction of a fracture when other techniques had failed.

Olecranon fractures treated with AO screw and tension bands.

Twenty-eight patients averaging 36.4 years of age underwent open reduction and internal fixation of olecranon fractures. The AO cancellous screw was used alone in 16 and with tension banding in 12. Banding was used when the bone was soft or severely comminuted. The fractures were clinically healed at an average of nine weeks and roentgenographic healing with obliteration of the fracture line occurred at 13 weeks. Sixty-seven percent acquired full motion by the ninth postoperative week. All but two patients regained full supination and pronation. No patient lost greater than 30 degrees of extension and only two lost greater than 30 degrees of flexion. There were few operative difficulties or postoperative complications. We found the AO cancellous screw alone and in severely comminuted cases in combination with tension band wiring to be an excellent fixation device for olecranon fractures. It allows for early range of motion in young patients with excellent healing prospects by 16 weeks.

Comparison of upper extremity kinematics in children with spastic diplegic cerebral palsy using anterior and posterior walkers

This prospective study analyzes the upper extremity kinematics of 10 children with spastic diplegic cerebral palsy using anterior and posterior walkers. Although both types of walkers are commonly prescribed by clinicians, no quantitative data comparing the two in regards to upper extremity motion has been published. The study methodology included testing of each subject with both types of walkers in a motion analysis laboratory after an acclimation period of at least 1 month. Overall results showed that statistically, both walkers are relatively similar. With both anterior and posterior walkers, the shoulders were extended, elbows flexed, and wrists extended. Energy expenditure, walking speed and stride length was also similar with both walker types. Several differences were also noted although not statistically significant. Anterior torso tilt was reduced with the posterior walker and shoulder extension and elbow flexion were increased. Outcomes analysis indicated that differences in upper extremity torso and joint motion were not dependent on spasticity or hand dominance. These findings may help to build an understanding of upper extremity motion in walker-assisted gait and potentially to improve walker prescription.

Traumatic unilateral avulsion of the anterior superior and inferior iliac spines with anterior dislocation of the hip: a case report.

A sixteen-year-old boy involved in a high-speed motor vehicle accident sustained an anterior hip dislocation and avulsion of the anterior ilium extending from the anterior superior iliac spine to the anterior inferior iliac spine. The hip was emergently reduced, and further imaging was obtained to evaluate the bony injury. Computed tomography confirmed the presence of a large displaced bony fragment representing avulsion of the anterior superior and inferior iliac spines and a smaller fragment from the reflected head of the rectus femoris. The patient underwent open reduction and internal fixation of the ilium two days after the initial injury. Postoperatively, he was allowed to bear weight as tolerated with crutches but to avoid active hip flexion. He went on to an uneventful recovery, and at last report (approximately six months after injury), he had returned to full activity. An extensive review of the literature failed to show a similar injury of ipsilateral avulsion of the anterior superior and inferior iliac spines and reflected head of the rectus femoris.

A biomechanical analysis of upper extremity kinetics in children with cerebral palsy using anterior and posterior walkers

Upper extremity (UE) joint kinetics during aided ambulation is an area of research that is not well characterized in the current literature. Biped UE joints are not anatomically designed to be weight bearing, therefore it is important to quantify UE kinetics during assisted gait. This will help to better understand the biomechanical implications of UE weight bearing, and enable physicians to prescribe more effective methods for treatment and therapy, perhaps minimizing excessive loads and torques. To address this challenge, an UE model that incorporates both kinematics and kinetics has been developed for use with walkers instrumented with load cells. In this study, the UE joint kinetics are calculated for 10 children with cerebral palsy using both anterior and posterior walkers. Three-dimensional joint reaction forces and moments are fully characterized for the wrist, elbow, and shoulder (glenohumeral) joints for both walker types. Statistical analysis methods are used to quantify the differences in forces or moments between the two walker types. Comparisons showed no significant differences in kinetic joint parameters between walker types. Results from a power analysis of the current data are provided which may be useful for planning longer term clinical studies. If risk factors for UE joint pathology can be identified early, perhaps a change in gait training routine, walker prescription, or walker design could prevent further harm.

Subtrochanteric fracture as a complication of proximal femoral pinning

The circumstances of subtrochanteric fractures following the use of multiple pins for fixation of femoral neck fractures were reviewed in four women (age range, 67-94 years). Internal fixation by use of multiple pins in the proximal femur is a common orthopedic procedure. The pins, however, create a significant stress riser in the lateral subtrochanteric cortex. Subtrochanteric fracture has been reported after internal fixation of slipped capital femoral epiphysis with multiple conventional pins and, recently, after internal fixation of femoral neck fractures with large Garden screws.

PRedominance of type II collagen in synovial chondromatosis.

Synovial chondromatosis is an uncommon condition in which islands of cartilage appear in the synovial lining of joints,8 tendons,” or bursae.13 These nests may remain cartilaginous, calcify, or differentiate into bone.’ The cartilaginous nodules can detach to form loose bodies in affected joints and may produce secondary degenerative changes on a mechanical basis. The accepted mode of treatment is synovectomy. The chondromas are assumed to be the end-products of metaplasia of the subintimal tissue of the synovial membrane. The hypothetical origin is supported by the morphologic features of synovial chondromatosis, which include nests of metaplastic cells, apparently transforming into chondrocytes, interspersed among abundant nodules of hyaline cartilage containing mature chondrocytes.” Little is known about the biochemical differentiation of the subintimal cells. This report describes the collagen profile of chondromas obtained from the synovium of a patient who had typical synovial chon-

Biomechanical system for the evaluation of walker-assisted gait in children: design and preliminary application

This study is an extension of earlier work to incorporate walker handle dynamometers with a video motion analysis system. The purpose of this study is to more fully address the quantitative metrics identified in the pilot study with a more sophisticated biomechanical model and instrumentation system, and a larger subject population. Preliminary findings of walker comparisons indicate differences in shoulder and elbow angles when comparing anterior and posterior walkers.