Adekile AD, et al. - In patients with sickle cell disease (SCD), researchers determined the role of hydroxyurea (HU) in the pathogenesis of avascular necrosis of the femoral head (AVNFH). Participants in the study were Kuwaiti children with SCD who were treated with HU. The results from this prospective cohort study indicate that the frequency and rate of progression of AVNFH were much less than that previously reported for the patients not treated with HU. No evidence indicated that HU therapy increased risk for AVNFH. It might stop new lesions and discourage progression of existing AVNFH. Reticulocyte count was the only hematological parameter that was consistently related to AVNFH.