VWF and osteonecrosis: Both asparaginase and glucocorticoids have been shown to induce a hypercoagulable state by suppression of anticoagulant factors such as antithrombin, plasminogen and d-dimer, and by elevation in F VIII/vWF complex.[30] The hypercoagulable state may lead to impaired circulation, vascular damage and subsequent osteonecrosis.[29, 31–33] Interestingly, patients between 11 and 16 years had more significant alteration of anticoagulant and fibrinolytic parameters than children of other ages,[34] consistent with the high susceptibility of adolescents to osteonecrosis.