S. Tamaoki, T. Atsumi, Y. Hiranuma, K. Yamano, T. Kajiwara,
K. Nakamura, Y. Asakura, E. Kato and M. Watanabe
Department of Orthopaedic Surgery, Fujigaoka Hospital, Showa University School of Medicine, Yokohama, Japan
Introduction: Since 2004, in addition to the original curved varus osteotomy for osteonecrosis of the femoral head, we have intentionally performed anterior or posterior rotation without incising the articular capsule to obtain a more extensive viable area in the loaded portion. We investigated the extent of viable area on the loaded portion after this modified operation.
Materials and Methods: Subjects included 11 patients (13 joints: anterior, 12 joints; posterior, 1 joint) who underwent a modified curved varus osteotomy and anterior or posterior rotation. We investigated the percent of viable area in the preoperative vs. the postoperative weighted portion. In addition, we measured the extent of viable area in the loaded portion when the extent of curved varus osteotomy without rotation was performed based on a schematic drawing.
Results: In this study, the combination of transtrochanteric curved varus osteotomy and anterior or posterior rotation significantly increased the percent viable area from 66% to 85%.
Discussion: The extent of postoperative viable area on the loaded portion might have been increased more than in the original procedure.