EP1.90 Direct anterior approach for open correction of Slipped Capital Femoral Epiphysiolysis: surgical technique and clinical outcome

Abstract Introduction Slipped Capital Femoral Epiphysis (SCFE) is an idiopathic hip disorder in adolescents. With or without surgery, avascular necrosis (AVN) is the most dangerous complication. For open reduction and internal fixation, the modified Dunn procedure is considered the gold standard. This study presents an open epiphyseal realignment through the Hueter-interval and reports on (1) surgical technique of direct anterior approach (DAA) based surgical realignment, (2) radiographic correction of biomechanics, and (3) AVN-incidence after surgery. Materials and Methods A single-center retrospective case series was conducted including all patients who underwent open realignment for SCFE via the direct anterior approach between January 2014 and January 2025. Pre- and postoperative Southwick and alpha angles were measured by two independent observers. Complications, including avascular necrosis, chondrolysis, and degenerative changes, were assessed at final follow-up. Descriptive statistics were used. Interobserver agreement of radiographic measurements was assessed using the intraclass correlation coefficient (ICC). Results Twelve patients (13 hips; 9 boys and 3 girls) were included. Median age and BMI were respectively 12.9 years old (IQR 12.2-13.7) and 23.1 kg/m2 (IQR 19.9-29.5) kg/m2. One patient showed bilateral involvement. Median preoperative AP - and lateral Southwick angle were respectively 117.5 (IQR 95.8–137.3) and 59.6 (IQR 35.1–71.8) degrees. After open realignment, median postoperative AP – and lateral Southwick angles were respectively 139.5 (IQR 135.0–143.3) and 14.7 (IQR 11.3–20.9). Thus, a correction of the lateral Southwick angle of 31.2 (IQR 17.4–54.2) was achieved. Follow-up was 6.0 years (IQR 2.4-8.3) and none of the patients developed AVN. Median Alpha-angle on Dunn view at final follow-up was 44.5 (IQR 42.8–68.1). Conclusion The DAA described in this series, can be considered a reproducible technique for an open realignment of displaced SCFE. None of the cases had an AVN and the approach does not appear to limit correction potential.