Abstract
Introduction: A single hip screw is the recommended method of fixation for slipped upper femoral epiphysis (SUFE). Current practice favours the placement of the screw in the centre of the femoral head on both anteroposterior and lateral planes to avoid the risks of chondrolysis and avascular necrosis (AVN).
Aims: To investigate the correlation between different positions of the screw in the femoral head and the prevalence of AVN, chondrolysis, late slippage, and the time to epiphyseal closure.
Methods: The clinical notes and radiographs of 38 consecutive patients (61 hips), who underwent single screw fixation for SUFE, were evaluated retrospectively with a mean follow up of 36 months. Two way ANOVA and post hoc test was performed to analyse the correlation between the different variables and the outcome, at 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 encountered in 39 hips, moderate in 4 and severe in 1 hip. Central-Central position was only achieved in 51% of cases. The most significant results of the study were as follows. I: No significant difference between the time to epiphyseal closure and the position of the screw. II. No late slippage or chondrolysis was observed in our series.
Conclusion: Our results showed that the position of the screw, other than in the centre of the femoral head, has the ability to provide physeal stability and has no correlation with the timing to closure of the epiphysis and the risk of avascular necrosis or chondrolysis. We therefore recommend that other positions be considered if the “optimal central-central position” is not initially achieved specifically for the treatment of mild SUFE as the potential hazards from several attempts to achieve the optimum position outweigh the benefits.
Correspondence should be addressed to Mr John Hodgkinson, BHS, c/o BOA, The Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PE.
