title: Osteoporotic changes of subchondral trabecular bone in osteoarthritis of the knee: a 3-T MRI study.
abstract: CONCLUSIONS
  Subchondral trabecular bone structure was analyzed in knee osteoarthritis (OA) patients using 3-T MRI to investigate structural features of subchondral trabecular bone of knee OA. With OA progression, osteoporotic changes were observed in the lateral joint, showing a higher correlation than sclerotic changes in the medial joint.
  
  
  BACKGROUND
  To investigate structural features of subchondral trabecular bone of knee osteoarthritis (OA).
  
  
  METHODS
  Sixty knees with KL grade 0-4 (all female) were examined. Fast imaging employing steady-state acquisition-cycled phases (FIESTA-c) and FatSat Spoiled gradient recalled acquisition in the steady state (SPGR) images were acquired by 3-T MRI. At four sites (the medial femur, medial tibia, lateral femur, and lateral tibia), subchondral trabecular bone structure was analyzed by FIESTA-c imaging, cartilage area was measured by SPGR imaging, and their correlation was analyzed. In addition, the subjects were classified into four groups from the cartilage area measured by SPGR imaging, and subchondral trabecular bone structure in each group was compared.
  
  
  RESULTS
  As cartilage area decreased in the medial joint, bone volume fraction and trabecular thickness in the medial tibia increased, and bone volume fraction, trabecular thickness, number, and connectivity in the lateral femur and lateral tibia decreased (r ≥ 0.4 or ≤-0.4, p ≤ 0.001). Compared to medially, the changes laterally showed a higher correlation. When the medial-lateral ratio of trabecular thickness in the tibia was determined, it had the highest correlation coefficient (r=-0.7, p < 0.001). These changes were not significantly detected in the early stage.
  
  
  CONCLUSIONS
  To more sensitively detect OA changes in subchondral trabecular bone structure, a focus on osteoporotic changes in the lateral joint and the medial-lateral ratio would be useful. Detectability of early OA remains unknown, but based on a strong correlation with the degree of OA progression, trabecular structural analysis of subchondral bone may be a useful parameter to evaluate OA severity and evaluate treatment.
authors.affiliation: Department of Orthopaedic Surgery, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. kohchiba@estate.ocn.ne.jp
authors.forename: K
authors.initials: K
authors.lastname: Chiba
authors.forename: M
authors.initials: M
authors.lastname: Uetani
authors.forename: Y
authors.initials: Y
authors.lastname: Kido
authors.forename: M
authors.initials: M
authors.lastname: Ito
authors.forename: N
authors.initials: N
authors.lastname: Okazaki
authors.forename: K
authors.initials: K
authors.lastname: Taguchi
authors.forename: H
authors.initials: H
authors.lastname: Shindo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002358:Cartilage, Articular / Q000473:pathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications* / Q000175:diagnosis; D010024:Osteoporosis / Q000175:diagnosis / Q000209:etiology*; D013977:Tibia / Q000473:pathology