title: How does osteonecrosis about the knee progress in young patients with leukemia?: a 2- to 7-year study.
abstract: BACKGROUND
  Osteonecrosis is a major treatment complication of pediatric leukemias owing to its potential to cause joint deterioration. Because of potential long-term effects of osteonecrosis on joints, information regarding its progression and collapse in different patients can be used to identify high-risk groups, advise the patients and parents of this complication, and potentially consider the risk for development of osteonecrosis in planning primary treatment.
  
  
  OBJECTIVE
  We therefore determined: (1) the incidence of joint collapse and/or pain in young patients with hematologic malignancies diagnosed with ON of the knee; (2) risk factors associated with collapse; and (3) the relationship between size and location of osteonecrotic knee lesions and the likelihood of joint collapse.
  
  
  METHODS
  We retrospectively reviewed 109 patients with hematologic malignancies and MRI-confirmed knee osteonecrosis. The median age was 11.5 years (range, 2.3-18.8 years) at primary diagnosis of hematologic malignancy and a median age of 13.4 years (range, 2.7-23.3 years) at diagnosis of osteonecrosis of the knee. For analyses, we used the first and last MR images. Minimum clinical followup was 2.3 years after diagnosis of knee osteonecrosis (median, 6 years; range, 2.3-7.17 years).
  
  
  RESULTS
  Joint collapse occurred in 22% (24 of 109). Older age, pain at osteonecrosis presentation, and lesions extending to the articular surface of distal femoral epiphyses were associated with joint collapse.
  
  
  CONCLUSIONS
  Younger patients and those without extensive femoral epiphyseal involvement have a better prognosis for osteonecrosis of the knee.
  
  
  METHODS
  Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University, St Louis, MO, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Karimova
authors.forename: A
authors.initials: A
authors.lastname: Wozniak
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.forename: M D
authors.initials: MD
authors.lastname: Neel
authors.forename: S C
authors.initials: SC
authors.lastname: Kaste
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000970:Antineoplastic Agents / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D007938:Leukemia / Q000188:drug therapy*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D010020:Osteonecrosis / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology; D010146:Pain / Q000139:chemically induced; D010147:Pain Measurement; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents