Avascular necrosis of bone following allogeneic stem cell transplantation: MR screening and therapeutic options.

With improvement in long-term survival after allogeneic stem cell transplantation, late complications with significant morbidity are of increasing importance. We retrospectively analysed 272 recipients of an allogeneic stem cell transplant for the development of osteonecrosis. The incidence among allograft recipients was 6.3% (17/272) for the whole patient population, and 11.8% (17/144) for long-term survivors. All patients were treated with high-dose prednisolone, 16 for severe acute or extensive chronic graft-versus-host disease (GVHD) and one patient for graft rejection. The mean age at time of diagnosis was 33 years (range 16-45) and the mean time from transplant to diagnosis of osteonecrosis was 13 months. Osteonecrosis was diagnosed by magnetic resonance (MR) imaging, which allows early detection of osteonecrosis and assessment of stage. At the time of diagnosis, eight patients had stage I, three patients stage II, three patients stage III and three patients stage IV osteonecrosis according to MR criteria. All but one patient had involvement of the femoral head. The median total dosage of prednisolone at the time of diagnosis was 189 mg/kg (single manifestation 150 mg/kg; multiple manifestations 313 mg/kg) with a total range of 13-555 mg/kg. Six patients were treated by conservative means, 77 patients underwent surgery (three core decompression, eight joint replacement). MR screening of patients receiving high-dose steroids might help to detect osteonecrosis at an early stage and thus prevent progression by early intervention, for example, by core decompression.