Femoral varus osteotomy in Legg-Calvé-Perthes disease: points at operation to prevent residual problems.

We analyzed at skeletal maturity the radiographic results of 46 patients with unilateral Legg-Calvé-Perthes disease (LCPD) who were treated with femoral varus osteotomy (FVO) with special attention to proximal femoral growth. In 30 patients, leg-length discrepancy (LLD) and alignment change in the leg also were examined. The postoperative femoral neck shaft angle (FNSA) was not related to the result on Stulberg's criteria, but the postoperative acetabulum head index (AHI) was. Trochanteric prominence remained on the affected side in spite of an improvement in FNSA. LLD did not depend chiefly on FVO itself. The alignment of the leg on the affected side showed a tendency to valgus, which occurred to correct the mechanical axis displaced medially by the FVO. Along with an FVO for LCPD, some additional operative technique should be performed to prevent trochanteric prominence and medial displacement of the distal fragment to prevent genu valgum.