Outcomes of Morscher's Femoral Neck Lengthening Osteotomy for Coxa Brevis

Abstract

Background: Coxa brevis, often a sequela of childhood hip disorders such as Legg-Calvé-Perthes disease (LCPD), developmental dysplasia of the hip (DDH), and Perthes-like diseases, results in a shortened femoral neck, proximal migration of the greater trochanter, and limb-length discrepancy (LLD). These morphological changes adversely affect hip biomechanics, leading to pain, limping, and functional disability. Purpose: This study evaluates the radiological and clinical outcomes of Morscher femoral neck lengthening osteotomy (FNLO) using a dynamic hip screw (DHS) in patients with coxa brevis due to various childhood hip pathologies. Methods: This retrospective study included 21 patients who underwent triple oblique proximal femoral osteotomy as described by Morscher, stabilized using a DHS. Pre- and postoperative measurements included Harris Hip Score (HHS), limb-length discrepancy (LLD), articulotrochanteric distance (ATD), centro-trochanteric distance, medial proximal femoral angle (MPFA), and lever arm ratio (LAR). Results: The mean age at surgery was 14 years. The mean LLD improved from 2.8 cm to 0.54 cm (mean gain of 2.2 cm). The ATD improved by a mean of 22 mm. The MPFA improved from 62° to 90°, and the LAR decreased significantly from 2.25 to 1.65 (p = 0.004). The mean HHS improved from 66.5 to 89.5. 14 Of the 16 patients with a preoperative positive Trendelenburg sign, showed resolution postoperatively. No major complications were observed during the short-term follow-up. Conclusion: Morscher osteotomy with DHS fixation offers a reproducible and effective approach to treat extra-articular deformities in coxa brevis, restoring hip biomechanics, improving limb-length discrepancy, and enhancing abductor function with minimal complications. Long-term follow-up is warranted to assess durability of outcomes.