| Summary points: | A 36-year-old presents with evidence of sclerotic changes and osteophyte formation on radiographs obtained 5 years after undergoing treatment for osteonecrosis of both femoral heads by core decompression and allograft in the left side and by injection of autologous cultured osteoblasts in the right side. This case report details the findings from isolation of bone marrow stromal cells and culture of osteoblasts, the surgical treatment, and outcome, and includes some images. The authors discuss the benefits and drawbacks of using cultured autologous osteoblasts to treat osteonecrosis. |