Cell-based therapies for osteonecrosis of the femoral head.

Osteonecrosis of the femoral head is a disabling condition and a known complication of hematopoietic cell transplants (HCT). It is characterized by empty lacunae in the osseous matrix and necrotic marrow elements. The most important risk factor in HCT recipients is steroid exposure, frequently in the context of graft-versus-host disease. Current treatment is surgical, and involves decompression of the affected area and the use of bone grafts or hip arthroplasty. Cellular-based therapies are now under investigation, and can be used in addition to, or instead of, invasive surgery. This review presents an overview of osteonecrosis with particular emphasis on HCT recipients and introduces the role of cell therapy, especially with mesenchymal stromal cells, as a promising new treatment.