Osteotomies for avascular necrosis of the femoral head.

BACKGROUND: In osteonecrosis of the femoral head (ONFH), blood supply is insufficient for the metabolic requirements of the bone. The initial management is conservative, and, in case of failure, surgery is indicated. Osteotomies aim to change the spatial position of the necrotic portion of the femoral head. This systematic review evaluates the effectiveness and safety of osteotomies for ONFH. SOURCE OF DATA: The systematic review, organized, conducted and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, was performed on PubMed and Google Scholar. We analysed outcomes in term of Harris Hip Score, leg shortening, secondary collapse and blood loss. We also verified the percentage of patients who required total hip replacement (THR) after osteotomy for ONFH. AREAS OF AGREEMENT: A total of 16 articles were selected, including 775 patients and 852 osteotomies [curved varus osteotomy in 369 (43.3%) patients; transtrochanteric rotational osteotomy in 435 (51.05%) patients; half wedge osteotomy in 48 (5.6%) patients]. There was an overall THR conversion rate of 31.5% (268 hips on 852 osteotomies). AREAS OF CONTROVERSY: There were no prospective randomized trials, and the outcome measures employed were often heterogeneous. GROWING POINTS: Approximately one-third of the osteotomies performed in cases of ONFH are converted to THR over a period of ~7 years. In older patients, primary THR should be considered, especially as the conversion to THR after osteotomy is technically demanding. AREAS TIMELY FOR DEVELOPING RESEARCH: Randomized clinical studies should be conducted in order to define the parameters of the patient that can direct towards the most suitable osteotomic technique.