Prevalence of osteonecrosis and associated risk factors in children before allogenic bone marrow transplantation

Osteonecrosis (ON) is a debilitating long-term complication of allogenic bone marrow transplantation (alloBMT) but may begin before alloBMT in some children because of their primary disease treatment. Therefore, to estimate the prevalence and associated risk factors for ON before alloBMT, we conducted a retrospective analysis of magnetic resonance (MR) studies of 118 children who underwent first alloBMT at our institution between December 2000 and September 2007. Of the 118 consecutive patients, 107 (90.7%) underwent prospective MR studies irrespective of symptoms (69 males; median age at alloBMT 12.9 years), and 11 underwent MR studies for symptoms. Amongst the 107 who had prospective imaging, 23 (21.5%) had ON; nearly 50% had at least 30% epiphyseal involvement. Knees were more frequently involved than were hips; severity of ON was greater in hips. ON prevalence before alloBMT was 23.72% when all 118 patients were included in the denominator. Risk factor analysis, limited to MR studies performed irrespective of symptoms, revealed female gender (P = 0.049) and age ≥10 years at the time of MR study (P = 0.03) as significant risk factors and primary diagnosis of lymphoid malignancies and aplastic anemia trended towards significance. ON prior to alloBMT is a common occurrence in children.