Slipped capital femoral epiphysis: long-term outcome and remodelling after in situ fixation.

Abstract

In primary treatment of slipped capital femoral epiphysis (SCFE) in situ fixation reliably prevents slip progression. The aim of this study was to examine the long-term outcome of SCFE-patients treated by transfixation with Kirschner wires with a special focus on the remodelling process of the hips under this fixation method. 30 patients with stable SCFE (mean initial slip angle: 29°, mean follow-up: 10 years), who were treated with bilateral transfixation by Kirschner wires, were recruited for this study. At most recent follow-up patients were clinically and radiologically (X-ray and MRI) examined. Medical records were reviewed for previous follow-up time points. Range of motion: At most recent follow-up the mean range of motion was: extension/flexion: 0/0/121, abduction/adduction: 44/0/31, external rotation/internal rotation: 39/0/24. Nearly all dimensions of motion significantly improved during the postoperative course.Head-shaft angle: We saw a significant reduction of the mean head-shaft angle from 29° preoperatively to 11° at most recent follow-up (p<0.0001). Harris Hip Score (HHS): 24 patients had an excellent, 3 a good, 2 a fair and 1 a poor outcome defined by HHS. Remodelling: At most recent follow-up 25 patients achieved complete remodelling. The remodelling process took place especially during the first postoperative year.Angle alpha: The mean angle alpha of the affected hips at most recent follow-up was 62°. Transfixation with Kirschner wires leads to very good clinical, functional and radiologic results with a low complication rate. Furthermore the femoral head-neck junction retains enough plasticity for an active remodelling process.