The incidence, risk factors, and outcomes of symptomatic avascular necrosis of bone among Chinese pediatric patients with acute lymphoblastic leukemia по Calvin Pui Lun Hoo, Alex Wing Kwan Leung, Joyce Pui Kwan Chan, Yin Ting Cheung, Frankie Wai Tsoi Cheng, Terry Tin Wai Chow, Grace Kee See Lam, Sau Yin Ha, Alan Kwok Shing Chiang, Rever Chak Ho Li, Chi Kong Li