Autologous bone marrow cell implantation in the treatment of non-traumatic osteonecrosis of the femoral head: Five year follow-up of a prospective controlled study.

OBJECTIVE To determine the efficacy of bone marrow cell implantation into the necrotic lesion of the femoral head on clinical symptoms and the progression of osteonecrosis of the femoral head in comparison with core decompression. METHODS We studied nineteen patients and twenty four hips with early stage osteonecrosis of the femoral head. The hips were allocated to either core decompression only or core decompression and implantation of bone marrow cells. Both patients and assessors were blind with respect to treatment group assignment. The primary outcomes were clinical symptoms and disease progression. RESULTS Bone marrow implantation afforded a significant reduction in pain and in joint symptoms and reduced the incidence of fractural stages. At 60 months, eight of the eleven hips in the control group had deteriorated to the fractural stage whereas only three of the thirteen hips in the bone marrow graft group had progressed to that stage. Survival analysis showed a significant difference in the time to failure between the two groups at 60 months. Patients had only minor side-effects after the treatments. CONCLUSIONS This long term follow-up study confirmed that implantation of autologous bone marrow cells in the necrotic lesion might be an effective treatment for patients with early stages of osteonecrosis of the femoral head.