Patellofemoral dysbalance and genua valga: outcome after femoral varisation osteotomies

Introduction Patellofemoral dysbalance may be caused by trochlear dysplasia, an elevated TTTG distance, femoral or tibial torsional deformities, patella alta, or a genu valgum. The surgical procedure for the treatment of a genu valgum is varisation osteotomy, usually in the femoral aspect. Several authors believe that a genu valgum is one cause of patellofemoral dysbalance, but studies about the outcome of the treatment with a varisation osteotomy are rare. Materials and methods Nineteen knees in 18 patients, aged on average 28 (16–52) years were investigated in a retrospective study. The patients had symptoms of patellofemoral instability or anterior knee pain due to a genu valgum, without symptoms of a lateral femorotibial compartment. All patients underwent a femoral varisation osteotomy. The diagnostic investigation prior to surgery included full-leg radiographs and torsional angle CT scans. The pre-surgery and follow-up investigation included the visual analog scale (VAS), the Kujala score, the Japanese Knee Society score, the Lysholm score. Results The mean duration of follow-up was 44(10–132) months. The mean preoperative mechanical valgus was 5.6° (range 4–10°). Twelve patients mentioned patellar instability as the main symptom while 14 mentioned anterior knee pain. No redislocation occurred in the follow-up period. Anterior knee pain on the VAS ( p value