title: Total-body irradiation produces late degenerative joint damage in rats.
abstract: OBJECTIVE
  Premature musculoskeletal joint failure is a major source of morbidity among childhood cancer survivors. Radiation effects on synovial joint tissues of the skeleton are poorly understood. Our goal was to assess long-term changes in the knee joint from skeletally mature rats that received total-body irradiation while skeletal growth was ongoing.
  
  
  METHODS
  14 week-old rats were irradiated with 1, 3 or 7 Gy total-body doses of 18 MV X-rays. At 53 weeks of age, structural and compositional changes in knee joint tissues (articular cartilage, subchondral bone, and trabecular bone) were characterized using 7T MRI, nanocomputed tomography (nanoCT), microcomputed tomography (microCT), and histology.
  
  
  RESULTS
  T2 relaxation times of the articular cartilage were lower after exposure to all doses. Likewise, calcifications were observed in the articular cartilage. Trabecular bone microarchitecture was compromised in the tibial metaphysis at 7 Gy. Mild to moderate cartilage erosion was scored in the 3 and 7 Gy rats.
  
  
  CONCLUSIONS
  Late degenerative changes in articular cartilage and bone were observed after total-body irradiation in adult rats exposed prior to skeletal maturity. 7T MRI, microCT, nanoCT, and histology identified potential prognostic indicators of late radiation-induced joint damage.
authors.affiliation: Department of Orthopaedic Surgery.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Hutchinson
authors.forename: John
authors.initials: J
authors.lastname: Olson
authors.forename: Carl A
authors.initials: CA
authors.lastname: Lindburg
authors.forename: Valerie
authors.initials: V
authors.lastname: Payne
authors.forename: Boyce
authors.initials: B
authors.lastname: Collins
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Smith
authors.forename: Michael T
authors.initials: MT
authors.lastname: Munley
authors.forename: Kenneth T
authors.initials: KT
authors.lastname: Wheeler
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Willey
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000528:radiation effects; D002358:Cartilage, Articular / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D007596:Joints / Q000528:radiation effects*; D007719:Knee Joint / Q000528:radiation effects*; D008279:Magnetic Resonance Imaging; D008297:Male; D036103:Nanotechnology; D010003:Osteoarthritis / Q000209:etiology / Q000517:prevention & control; D051381:Rats; D011916:Rats, Inbred F344; D014916:Whole-Body Irradiation / Q000009:adverse effects*; D055114:X-Ray Microtomography
keywords: 7T MRI; Radiation; arthritis; articular cartilage; knee joints; nanocomputed tomography