Intralesional autologous mesenchymal stem cells in management of osteonecrosis of femur: a preliminary study.

BACKGROUND: Management of early stages of osteonecrosis aims to prevent the collapse of the femoral head by attempts at restoring the vascularity of femoral head. Bone marrow-derived mononuclear cells with their angiogenic and osteogenic properties appear to have the potential to halt the disease process when injected intralesionally following core decompression.

MATERIALS AND METHODS: Forty patients (60 hips) with stage I, II or III (ARCO system) osteonecrosis of femoral head were treated by either core decompression and isolated mononuclear cells (group A) or core decompression and unprocessed bone marrow injection (group B). The patients were followed up clinically and radiologically for a minimum of 2 years. The functional outcome was assessed in terms of Harris hip score, and disease progression was assessed radiologically by comparing the preoperative and follow-up MRI at the end of 2 years.

RESULTS: On 2-year follow-up, there was considerable improvement in the hip function as measured by the Harris hip score in both the groups (p = 0.031). On MRI, there was a decrease in the size of the lesion in group A (p = 0.03). Three of 30 hips (10.0 %) in group B required total hip replacement.

CONCLUSIONS: Implantation of autologous bone marrow stem cells in avascular necrosis of femoral head is a safe and effective procedure and has better outcome than bone marrow for early stage of avascular necrosis of femoral head.