Modified Trochanteric Flip Osteotomy in Varus Intertrochanteric Osteotomy for Treatment of Legg–Calvé–Perthes Disease

Abstract

Background/Objectives: Legg–Calvé–Perthes disease (LCPD) presents challenges in treatment due to its varied course and unclear etiology. This study aimed to evaluate the efficacy of combining proximal femoral varus osteotomy (PFVO) with a modified trochanteric flip osteotomy to address biomechanical consequences and improve hip abductor muscle strength. Methods: We present a modified approach combining PFVO with a trochanteric flip osteotomy. In this technique, the greater trochanter in compound with its muscular insertions is separated from the femur and attached distally using a varization blade plate. Nine patients (ten hips, mean age 8 years) with LCPD were treated using this technique. Clinical examination findings and radiographic evaluations were retrospectively analyzed. The median follow-up was 33 months. Results: At the last follow-up, two patients exhibited Trendelenburg gait, but hip abduction was improved in all patients. Radiographically, consolidation at the osteotomy site was observed in all cases with no delayed union or non-union. The median CE angle improved by 7°, while the median CCD decreased by 18°. The median MPFA decreased by 13°, resulting in a median of 82°. Conclusions: Combining PFVO with a modified trochanteric flip osteotomy addresses biomechanical issues associated with PFVO, potentially improving hip containment and abductor muscle strength. This approach may offer advantages over traditional osteotomy techniques in treating LCPD, and it appears to produce a superior functional outcome in particular in regard to limping when compared to conventional PFVO. Despite satisfactory radiological outcomes in most cases, further research is needed to assess long-term effectiveness and address challenges such as femoral head enlargement and persistent gait abnormalities.