Faculty Bibliography

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.

This retrospective study over a 3 year follow-up was designed to establish the significance of the Weber classification of ankle fractures with regards to functional and radiographic outcome. One hundred and seven patients were available for follow-up, of which 88 ankles could be classified with the Weber system. Medial malleolar fractures alone and pilon fractures could not be classified with this system. A correlation was found between the type of Weber fracture and the overall ankle score. This held true for unimalleolar fractures alone. More complex bimalleolar and trimalleolar fractures did not follow this convention. Logistical regression analysis was used to evaluate other predictors of outcome. Bimalleolar and trimalleolar fractures were statistically significant predictors of a poorer outcome (P = 0.033, P = 0.021). The initial degree of displacement was also determined to be a predictor of outcome (P = 0.0133) as was the operative reduction (P = 0.0113). Using linear regression, older age (> 62 years) was also established as a predictor of a poorer outcome (P < 0.05). The Weber classification was found to be a predictor of outcome in unimalleloar ankle fractures and not for multimalleolar fractures. We have identified further predictors of a poorer outcome in ankle fractures as the degree of initial injury, the number of malleoli fractured and older age. These factors were found to have greater significance in predicting outcome than the level of fibular fracture alone. We have identified a deficiency of the Weber system in excluding these criteria and have addressed this by modifying the existing system to include the number of malleoli involved, thus providing a more useful prognostic tool

We retrospectively reviewed 75 total hip arthroplasties to examine the effect of acetabular component position. In group A, 38 of the components were implanted according to manufacture's instructions with all peripheral fins in contact with acetabular bone; as such, the acetabular components were in a relatively vertical position with a mean angle of inclination of 61.9 degrees. Three of these patients developed recurrent dislocations necessitating revision of the acetabular component. In group B, 37 hips, a more horizontal orientation was used despite the fact that all of the peripheral fins of the acetabular component did not engage acetabular bone; in this group the mean angle of inclination was 49.7 degrees. Only one of these hips recurrently dislocated and required revision. There were no problems in this group associated with provisional component stability caused by inadequate peripheral fixation. Radiographs of all patients were obtained at 4 years after surgery (range, 4.0-4.3 years). Pelvic osteolysis had occurred in 24% of hips in group A and 13% of group B. Asymmetric polyethylene wear was observed in 5.1% of the hips in group A; no hip in group B showed wear asymmetry. Acetabular component migration developed in 19% of group A hips and 5% of group B hips. The Mayo clinical hip score was excellent in both groups: group A 71/80, group B 73/80. At an intermediate follow-up it is clear that significant problems can be encountered when this component is positioned in a relatively vertical position to facilitate engaging all four peripheral fins in bone. We have addressed this problem by placing the cup in a more anatomic position of inclination while maintaining provisional rim fixation. This has resulted in a decreased incidence of pelvic osteolysis and fewer complications overall.

Ninety patients who had undergone 92 total knee replacements were reviewed to determine predictors of postoperative pyrexia and to evaluate the relative value of septic screening in this group of patients. Postoperative pyrexia was defined as an axillary temperature greater than 37 degrees C (98.4 degrees F) on any or all of the 5 days after surgery. All of the patients in this series developed a postoperative pyrexia after knee arthroplasty. None of 16 patients (17% of arthroplasties) with a temperature of 39 degrees C (102 degrees F) or greater had evidence of infection. None of the 4 patients with urinary tract infections developed a pyrexia exceeding 38 degrees C (101 degrees F). At a minimum of 2 years' follow-up, none of the 90 patients had developed an infected arthroplasty. Logistic regression analysis showed that the risk of becoming significantly febrile (temperature > 39 degrees C) doubled for every unit drop in hematocrit and increased fourfold for each unit of blood transfused after surgery. Perioperative blood loss and pyrexia were correlated, but the correlation was not statistically significant. The duration of procedure, tourniquet time, and patient age or sex were not associated with risk of pyrexia. In this series, there was no association between a pyrexia greater than 37 degrees C, septic screening, and the presence of an infective focus. Early postoperative pyrexia after arthroplasty is a normal physiological response, and a significant pyrexia can be predicted by a drop in hematocrit and/or after postoperative transfusion. Pyrexia in the early postoperative period following total knee arthroplasty warrants detailed laboratory and radiographic investigation only in the presence of positive physical findings.

OBJECTIVE:To describe our experience with four cases of severe pelvic dislocation associated with difficult parturition. DESIGN/METHODS:Retrospective case series. PATIENTS/METHODS:Four patients, each with rupture of the symphysis pubis and sacroiliac joints during labor. All injuries were associated with significant initial pain and disability. All developed persistent symptoms related to the sacroiliac disruption. INTERVENTIONS/METHODS:The three patients who had presented acutely were freated with closed reduction and application of a pelvic binder. Two underwent closed reduction of their pelvic dislocation while anesthetized with a general anesthetic. One patient (N.A.), who presented late, had not been treated with a binder. RESULTS:All four patients had persistent posterior pelvic (sacroiliac) pain. In two patients a postpartum neuropathy persisted. CONCLUSIONS:Severe pelvic dislocations are rare during labor, with conservative treatment reported to be successful in most cases. The persistence of symptoms in our patients emphasizes the need for careful examination and follow-up of these rare injuries. Because the outcome in our patients was poor and results in the literature are equivocal, we suggest the consideration of an operative approach to treatment in patients with symphyseal diastasis of > 4.0 cm.