Faculty Bibliography

We describe the imaging features of a giant geode of the distal humerus in a patient with rheumatoid arthritis, which presented initially as a pathological fracture. The value of magnetic resonance imaging in establishing this diagnosis is emphasized.

We present the case of a child who developed a massive subperiosteal hemorrhage and subsequent osteonecrosis of her right femur after treatment with tissue plasminogen activator for post-varicella streptococcal purpura fulminans. Radiographs showed posteromedial translation of the capital femoral epiphysis on the necrotic shaft, and the hip was immobilized. The femur slowly remodeled and has continued to grow. The child is independently ambulatory with a 2.1-cm leg length discrepancy, a varus deformity of the hip, and a valgus distal femur.

BACKGROUND:A prospective, randomized controlled trial was used to compare the efficacy of the arteriovenous (AV) impulse system and aspirin in reducing venous thrombosis after fracture to the femoral neck. METHODS:A total of 143 patients underwent hemiarthroplasty, after which 70 patients were treated with the AV pump and a second group of 73 patients were commenced on 325 mg of aspirin. Duplex ultrasound was used to assess both proximal and distal venous thrombi on days 7 to 10. Calf and thigh circumferences were also measured. RESULTS:Thrombi developed in seven of the patients treated with aspirin and in four patients treated with the AV pump. No statistically significant difference could be established (p = 0.109). There was a significant reduction in both calf (p = 0.003) and thigh (p = 0.002) swelling in the group treated with the AV pump. Neither treatment group was a significant predictor of a poorer outcome by using logistical regression analysis (p = 0.258). CONCLUSIONS:Both aspirin and the AV pump are effective in reducing thromboembolic events after hemiarthroplasty of the hip.

We present a case of post-traumatic subchondral cyst formation in the talus. No evidence of an osteochondral defect was observed, however, the histological findings suggested a synovial origin. This implicates synovial herniation through traumatized articular cartilage into subchondral bone in a fashion analogous to osteoarthritic pathogenesis

Previously reported cases of fracture dislocation of the tarsal navicular bone have implicated dorsiflexion and longitudinal compression as the mechanism of injury. We report a case of navicular fracture dislocation which, by the description of the incident and the reduction manoeuvre employed, suggests that plantarflexion combined with inversion were the forces required to produce the deformity. Understanding of the mechanism of injury in these fractures may lead to easier closed reduction and improved outcome.

This retrospective review examined the cause, level of pathology, onset of symptoms, time taken to treatment, and outcome of 19 patients with cauda equina syndrome (CES). The minimum time to follow up was 22 months. Logistical regression analysis was used to determine how these factors influenced the eventual outcome. Out of 19 patients, 14 had satisfactory recovery at 2 years post-decompression; 5 patients were left with some residual dysfunction. The mean time to decompression in the group with a satisfactory outcome was 14 h (range 6-24 h) whilst that of the group with the poor outcome was 30 h (range 20-72 h). There was a clear correlation between delayed decompression and a poor outcome (P = 0.023). Saddle hypoaesthesia was evident in all patients. In addition complete perineal anaesthesia was evident in 7/19 patients, 5 of whom developed a poor outcome. Bladder dysfunction was observed in 19/19 patients, with 12/19 regarded as having significant impairment. Of the five patients identified as having a poor overall outcome, all five presented with a significant sphincter disturbance and 4/5 were left with residual sphincter dysfunction. There was a clear correlation between the presence of complete perineal anaesthesia and significant sphincter dysfunction as both univariate and multivariate predictors of a poor overall outcome. The association between a slower onset of CES and a more favourable outcome did not reach statistical significance (P = 0.052). No correlation could be found between initial motor function loss, bilateral sciatica, level or cause of injury as predictors of a poor outcome (P>0.05). CES can be diagnosed early by judicious physical examination, with particular attention to perineal sensation and a history of urinary dysfunction. The most important factors identified in this series as predictors of a favourable outcome in CES were early diagnosis and early decompression.