Fig 3.

Cumulative incidence of hip osteonecrosis by femur site in pediatric patients with acute lymphoblastic leukemia. The blue dotted line represents patients with any hip osteonecrosis, including epiphysis (to any extent) or metaphysis. The red dashed line represents patients with osteonecrosis of the epiphysis (regardless of the extent of epiphyseal involvement, but excluding patients whose only sites of hip osteonecrosis were in the metaphysis). The black line shows patients with epiphyseal osteonecrosis affecting ≥ 30% of the articular surface, which represents extensive osteonecrosis with high risk of subsequent joint collapse and need for arthroplasty.