RESEARCH ARTICLE The effects of necrotic les

Full list of author information is available at the end of the articleBackground Osteonecrosis of the femoral head (ONFH) is a devastat-ing disease that typically affects patients who are in the third through fifth decades of life. The development of ONFH is usually progressive, and it often leads to the collapse of the femoral head and the subsequent destruc-tion of the hip, requiring the joint to be reconstructed using a prosthetic replacement. Hip resurface arthroplasty (HRA) has several advan-tages compared with traditional total hip arthroplasty (THA), including a reduced rate of dislocation due to the larger diameter of femoral head, reduced wear of metal-on-metal interface, a larger range of motion and its bone-conserving nature [1-3]. Consequently, HRA is considered suitable for the treatment of young and ac-tive patients who have ONFH. Although promising re-sults have been reported in some short-term follow-up studies [4-6], aseptic loosening and narrowing of the femoral neck, which may lead to femoral neck frac-tures have also been reported in long-term follow-u