Tissue-engineered approach for the treatment of steroid-induced osteonecrosis of the femoral head: transplantation of autologous mesenchymal stem cells cultured with beta-tricalcium phosphate ceramics and free vascularized fibula.

Autologous mesenchymal stem cells (MSCs) cultured with beta-tricalcium phosphate (beta-TCP) ceramics and with a free vascularized fibula were transplanted into three patients with steroid-induced osteonecrosis of the femoral head. The average follow-up period was 34 months and the average patient age at the time of surgery was 28 years old. Fifteen milliliters of bone marrow was obtained from the patients 4 weeks before surgery, and was used for in vitro proliferation of MSCs. beta-TCP granules were immersed in the MSC suspension and the cells were further cultured for 2 weeks. Cultured MSCs/beta-TCP composite granules were implanted into the cavity that remained after curettage of necrotic bone; and finally, a free vascularized fibula was grafted. All hips showed preoperative collapse and radiographic progression was observed in two hips postoperatively. Osteonecrosis did not progress any further and early bone regeneration was observed. This tissue-engineered approach has potentials for the treatment of osteonecrosis. However, our results suggested that the present procedure could not be used for cases with severe preoperative collapse.