Volume 14-4, Winter 2005

The lateral head-shaft angle as described by Southwick is used to assess the severity of slipped capital femoral epiphysis and to measure progression. Intraobserver variability in measuring the lateral headshaft angle may influence decision making. The purpose of this study was to determine intraobservervariability in the measurement of the lateral head-shaft angle of slipped capital femoral epiphysis. The lateral head-shaft angle of 108 hips was measured twice by three observers. The two-way analysis of variance method of Bland and Altman as outlined by Loder was used to determine the intraobserver variability. For the lateral head-shaft angle in slipped capital femoral epiphysis, the intraobserver variability was +5.9°. To ensure true change, a single observer should document at least a 12° change in the lateral head-shaft angle between two radiographs.

Malignant peripheral nerve sheath tumors (MPNSTs) are highly malignant cancers that account for approximately 5–10% of all soft tissue sarcomas. They occur either sporadically, in association with neurofibromatosis type 1 (NF1), or subsequent to radiation therapy. Histologically, MPNSTs resemble fibrosarcomas in their basic organization. Immunohistochemistry, particularly S100, plays an important role in the diagnosis. At the molecular level, loss of the NF1 gene and high levels of Ras-activity are hallmarks. Magnetic resonance imaging (MRI) is the most helpful imaging technique to clearly identify tumoral extent and to suggest neurogenic origin. The presence of heterogeneity with evidence of necrosis and hemorrhage on MRI and increased uptake on positron emission tomography scan may prove helpful in detecting malignant changes. MPNSTs need to be approached by a multidisciplinary team, assuring the complete surgical removal of the lesion. Disease-free and overall survival statistics reinforce the aggressive nature of this unique soft tissue tumor.

Although direct osteosynthesis of certain types of odontoid fractures may increase union and decrease the need for prolonged immobilization, screw fixation remains a technically demanding procedure. This study compares radiation exposure, surgical time, and accuracy of hardware placement using standard fluoroscopy versus computer-assisted fluoroscopy-based navigation ("virtual fluoroscopyto")to assist with the placement of odontoid screws. Twenty-two cadavers were divided into two groups and underwent placement of a single odontoid screw using either standard fluoroscopic or virtual fluoroscopic guidance. Following screw placement, dissection of the C1–C2 segments was performed to assess accuracy. A significant reduction in fluoroscopy time was noted with the computer-based fluoroscopy technique, whereas the surgical time was not found to differ significantly between the techniques. No critical breaches (those risking neurovascular injury) were noted in either group, and the rate of noncritical breaches did not differ. The authors conclude that fluoroscopy-based virtual navigation appears to have a safety profile similar to standard fluoroscopy while allowing a reduction in radiation exposure.

Upper extremity dog bite wounds comprise a large percentage of all mammalian bite wounds. The purpose of the study was to assess the bacteriology of patients presenting with such injuries to the emergency room that required consultation by a hand surgeon. The study also analyzed the effect of delayed intervention on growth of invasive pathogens, on the incidence of multiple pathogens, on treatment interventions, and on length of hospital stay. Objective data and subjective descriptions of the wound were collected on 32 patients who presented to Chicago area hospitals. The authors retrospectively analyzed the data and grouped the patients into two categories based on time of intervention: early or those treated within 48 hours, and delayed to include those treated after 48 hours. Incidence of bacterial growth and Pasteurella species growth in cultures was similar to that reported in the literature. Delayed patients had a significantly higher incidence of positive bacterial growth from wound cultures (100%) compared with nondelayed patients (54%). Delayed patients also had a higher incidence of treatment intervention (delayed group 86% surgical irrigation and debridement compared with 48% for the early group). There was a trend toward increased length of hospital stay (delayed group 4.6 days compared with 2.6 days), although this was not significant. The growth of multiple pathogens between the two groups was similar and not significant (delayed group 43% compared with 54% early group).

Arthroplasty for intertrochanteric fractures in elderly patients may allow early weightbearing and avoid fixation failure. Clinical results are reviewed in a consecutive group of acute arthroplasties (5 hemiarthroplasties and 29 total hip arthroplasties) performed via the anterolateral approach for intertrochanteric fractures. Age averaged 80.2 years. Follow-up averaged 35 months for living patients. Twenty-six patients died during follow-up. Time to death averaged 3.5 years. Five hips, all total hip arthroplasties, required subsequent surgeries: four for dislocation and one revised for sepsis. Acute intertrochanteric fractures are associated with high early mortality. In this series, a 15% complication rate and high mortality rate at 12 years was associated with acute arthroplasty. Dislocation is higher than in primary total hip arthroplasty utilizing the same surgical approach. The results do not support routine use of arthroplasty in treatment of intertrochanteric hip fractures in the elderly.

This case report involves three patients in whom hip sepsis occurred in association with degenerative joint disease, in the absence of any risk factors for infection. The diagnosis had been missed on initial evaluation, and each patient had been referred to the authors’ adult reconstructive service to have the arthritic hip replaced. In each instance, existing hip pain had worsened acutely. Further workup led to the correct diagnosis and appropriate treatment of the septic joint. These cases illustrate the value of differential diagnosis when treating patients with degenerative hip disease.

Hallux valgus surgery aims to correct the nonphysiological angulation of the first ray and rebalance its function. Many techniques are reported, each with different indications depending on the pathoanatomy of the deformity. This article presents a minimally invasive distal metatarsal osteotomy technique, requiring no custom instrumentation. The operation is performed under direct vision and without fluoroscopy.