Abstract
Purpose of study: A single dynamic hip screw is the recommended method of fixation for slipped upper femoral epiphysis (SUFE). Current practice favours placement of the screw in the centre of the femoral head on both anteroposterior and lateral planes. This study investigated screw placement in the femoral head for SUFE and the prevalence of AVN, chondrolysis, late slippage, and time to physeal closure.
Method: Clinical notes and radiographs of 38 consecutive patients (61 hips), who underwent single screw fixation for SUFE, were evaluated retrospectively with a minimum follow up of 24 months (24–56). Two way ANOVA and post hoc tests were performed to analyse the correlation between the different variables and the outcome, at a 5% significance level.
Results: There were 16 acute slips, 18 chronic slips and 10 acute on chronic slips. 17 slips were treated prophylactically. Mild slip was noted in 39 hips, moderate in 4 and severe in 1 hip. A central-central position was only achieved in 50% of cases. No significant difference between the time to physeal closure and the screw position was found. No late slippage, AVN or chondrolysis occurred in this series.
Conclusions: Our results demonstrate that positions of the screw, other than in the centre of the femoral head, provide adequate stability. There is no correlation between screw position and the time to physeal closure, the risk of avascular necrosis or chondrolysis. We recommend that positions other than the “optimal central-central position” be accepted if not initially achieved, especially for mild SUFE. The potential hazards from several attempts to achieve the optimum position outweigh the benefits.
Correspondence should be addressed to: Mr J. B. Hunter, BSCOS, c/o BOA, The Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PE.
