title: MRI of knee osteonecrosis in children with leukemia and lymphoma: Part 2, clinical and imaging patterns.
abstract: OBJECTIVE
  This aim of this study was to explore the relationship between MRI findings and clinical symptoms of knee osteonecrosis in children and to determine the significance of this relationship. Such information is important for early diagnosis of this frequent complication and for choosing an appropriate treatment strategy.
  
  
  METHODS
  Osteonecrotic lesion size and location were determined in a retrospective analysis of MR images of the knee obtained in our institution during the past 10 years. Association between MRI findings and clinical symptoms expressed by the knee scores was tested for a subgroup of our patient population who had clinical evaluation of the knees in the orthopedic clinic within 6 weeks of their MRI studies.
  
  
  RESULTS
  In 80% of patients, osteonecrosis was bilateral. Lesions were distributed as follows: femur and tibia, 66% of the knees; femur alone, 26%; and tibia alone, 8%. Clinical symptoms of knee osteonecrosis were associated with lesions involving the articular surface of the distal femur, large lesions, and involvement of any part of the tibia. MR images showed milder osteonecrosis in patients who were less than 10 years old at the time of primary diagnosis.
  
  
  CONCLUSIONS
  Osteonecrosis affecting the knees of children treated for leukemia and lymphoma is mostly asymptomatic. Children who are 10 years old or older have signs of more advanced osteonecrosis. Clinical symptoms often lag MRI presentation and may develop late in the course of the disease. Routine MRI evaluation is recommended for timely diagnosis of treatment-induced osteonecrosis.
authors.affiliation: Department of Radiological Sciences, Division of Diagnostic Imaging, St. Jude Children's Research Hospital, 332 N Lauderdale St., Memphis, TN 38105, USA.
authors.forename: Evguenia J
authors.initials: EJ
authors.lastname: Karimova
authors.forename: Shesh N
authors.initials: SN
authors.lastname: Rai
authors.forename: David
authors.initials: D
authors.lastname: Ingle
authors.forename: Amy C
authors.initials: AC
authors.lastname: Ralph
authors.forename: Xin
authors.initials: X
authors.lastname: Deng
authors.forename: Michael D
authors.initials: MD
authors.lastname: Neel
authors.forename: Scott C
authors.initials: SC
authors.lastname: Howard
authors.forename: Ching-Hon
authors.initials: CH
authors.lastname: Pui
authors.forename: Sue C
authors.initials: SC
authors.lastname: Kaste
mesh_terms: D000293:Adolescent; D000970:Antineoplastic Agents / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007223:Infant; D007719:Knee Joint / Q000473:pathology*; D007938:Leukemia / Q000150:complications* / Q000188:drug therapy; D008223:Lymphoma / Q000150:complications* / Q000188:drug therapy; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010020:Osteonecrosis / Q000139:chemically induced / Q000175:diagnosis*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
chemical_list: D000970:Antineoplastic Agents