Joint Preservation of Severe Osteonecrosis of the Femoral Head Treated by Posterior Rotational Osteotomy in Young Patients: More Than 3 Years of Follow-up and Its Remodeling

Posterior rotational osteotomy in 48 hips of 40 young patients with femoral head osteonecrosis with extensive and apparent collapsed lesions were reviewed with a mean of 9.2 years of follow-up. No viable area was seen on the articular surface of the femoral head of the loaded portion on preoperative anteroposterior radiographs in all femoral heads. All hips had greater than 3 mm collapse; 40 hips showed no apparent joint narrowing, and 8 hips revealed joint narrowing. Posterior viable area of joint surface before surgery ranged from 6% to 29%, with a mean of 19%, on lateral radiographs. Anterior viable area ranged from 6% to 42% with a mean of 21%. The mean age of the patients was 29 years, with 13 women and 27 men. Thirty-five hips were nontraumatic, and 13 were traumatic. Mean postoperative viable area below the acetabular roof was 59% on anteroposterior radiographs and 54% on 45° flexed radiographs. Recollapse was prevented in 44 hips (92%), with adequate viable area on the loaded portion on final follow-up radiographs. Progressive joint narrowing was found in 9 hips. Resphericity of the postoperative transferred medial collapsed area of the femoral head was observed on 34 of 35 hips on final anteroposterior radiographs. The joint space was increased in 6 of 8 hips. Posterior rotational osteotomy appeared to be effective in delaying the progression of degeneration in young patients with extensive collapsed osteonecrotic lesions.