Avascular necrosis of bone after allogeneic bone marrow transplantation: analysis of risk factors for 4388 patients by the Société Française de Greffe de Moëlle (SFGM).

Increasing numbers of patients are surviving after allogeneic bone marrow transplantation and are therefore at risk for developing late complications. Among these complications, avascular necrosis of bone has been reported, but only two single-centre studies included sufficient patients to enable analysis of the risk factors for developing avascular necrosis. In this multicentre retrospective study the aim was to assess risk factors for this complication in a large number of patients. The population consisted of 4388 patients, recorded in the Societe Francaise de Greffe de Moelle (SFGM) data base, who had undergone a single allogeneic bone marrow transplant between January 1974 and December 1993. 77 patients developed avascular necrosis leading to a 4.3% projected incidence at 5 years. Symptoms developed 2-132 months after transplantation. In these 77 patients a mean of 1.87 joints per patient were affected (range 1-7). The hip joint was the most often affected (88% of patients) and 48% of the patients required joint replacement. All but two patients received steroids for acute and/or chronic graft-versus-host disease (GvHD) over a mean period of 15 months. In univariate analysis, among eight factors tested as risk factors for developing avascular necrosis, six were shown to be linked to an increased risk: older age, diagnosis of aplastic anaemia or acute leukaemia, an irradiation-based conditioning regimen, type of GvHD prophylaxis regimens, acute and chronic GvHD. In multivariate logistic regression analysis, five factors remained significantly associated with an increased risk for developing avascular necrosis: chronic GvHD (odds ratio (OR) 3.52), acute GvHD (OR 3.73), age > 16 years (OR 5.81), aplastic anaemia (OR 3.90), and acute leukaemia (OR 1.72). Avascular necrosis is not a rare late complication of allogeneic bone marrow transplantation causing significant morbidity. In this study, older age, initial diagnosis, and GvHD and/or its treatment with steroids emerged as significant risk factors.