Long term follow-up of transtrochanteric rotational osteotomy in patients with extensive and collapsed femoral head osteonecrosis

Background: Transtrochanteric rotational osteotomy (TRO) potentially can salvage hips with extensive and collapsed lesions of femoral head osteonecrosis (ONFH). However, the results varied greatly and few long term results were reported. Methods From 1998 to 2001, TRO had been done on 15 ONFH hips. The mean age of the patients was 42 years. All hips were associated with extensive lesions and in the early collapsed stage (ARCO staging system, IIIA less than 2 mm collapse in 10 hips and IIIB 2 to 4 mm collapse in 5 hips). Demographic data, Harris hip score, and radiological outcomes were reviewed. Results: Anterior rotational osteotomy was done in 11 hips and posterior rotational osteotomy was done in 4 hips. The index of necrosis was 39% in average (range, 12% to 68%). In the 15 hips with an average follow-up of 11 years, the Harris hip score improved from 39.1 to 76.2. Six hips were converted to total hip replacement in an average of 3.6 years. The overall survival rate for conversion to total hip replacement as the end point was 60%. The overall radiological success rate was 53.3% Conclusions: TRO is a worthy procedure to preserve extensive and collapsed hips with acceptable success rate. Technical difficulties while executing the surgery or converting to total hip replacement should be considered and discussed fully with the patients.