Clinical and radiological outcomes of treatment of avascular necrosis of the femoral head using autologous osteochondral transfer (mosaicplasty). Preliminary report

PURPOSE: The purpose of this study was to evaluate clinical and radiological outcomes of autologous osteochondral transfer (OATS) for femoral head osteonecrosis. METHODS: Twenty-one hips in 20 patients (one woman and 19 men), average patients' age at the time of surgery of 35.4 (range 20–56) years, were treated with OATS for osteonecrosis of the femoral head (ONFH). Seven patients at pre-collapse ARCO stages IIA and IIB were treated with OATS alone. Thirteen patients with large pre-collapse ARCO IIC and post-collapse ARCO III and IV were treated with OATS and morselised bone allografts (OATS/allograft). Harris hip score (HHS) was used for clinical evaluation of outcomes; X-rays were performed to examine the evolution of the disease. Kaplan-Meier survival curves were used to determine the failure of the procedures with conversion to THR defined as endpoint. RESULTS: Follow-up of patients treated with OATS alone was 46.14 (range 18–75) months with HHS improvement from a preoperative mean of 42 to 87.85 points at the latest follow-up examination. Only one patient in this group needed a revision operation with THR. The survival for this group of patients was 85.71 % at four years. Follow-up of patients treated with AOTS/allograft was 32.7 (range 7–84) months with HHS improvement from a preoperative mean of 35.2 to 65.7 points at the latest follow-up examination. One patient died six months after the surgery. There were five conversions to THR because of femoral head collapse in this group of patients with survival of 61.54 % at three years. CONCLUSION: The use of osteochondral grafts offers the possibility of successful treatment for ONFH at small and medium pre-collapse stages. The outcomes of large pre-collapse and post-collapse stages were below our expectations. OATS is a time buying procedure for young patients as it may defer total hip replacement.