title: Relationship of compartment-specific structural knee status at baseline with change in cartilage morphology: a prospective observational study using data from the osteoarthritis initiative.
abstract: BACKGROUND
  The aim was to investigate the relationship of cartilage loss (change in medial femorotibial cartilage thickness measured with magnetic resonance imaging (MRI)) with compartment-specific baseline radiographic findings and MRI cartilage morphometry features, and to identify which baseline features can be used for stratification of fast progressors.
  
  
  METHODS
  An age and gender stratified subsample of the osteoarthritis (OA) initiative progression subcohort (79 women; 77 men; age 60.9 +/- 9.9 years; body mass index (BMI) 30.3 +/- 4.7) with symptomatic, radiographic OA in at least one knee was studied. Baseline fixed flexion radiographs were read centrally and adjudicated, and cartilage morphometry was performed at baseline and at one year follow-up from coronal FLASH 3 Tesla MR images of the right knee.
  
  
  RESULTS
  Osteophyte status at baseline was not associated with medial cartilage loss. Knees with medial joint space narrowing tended to show higher rates of change than those without, but the relationship was not statistically significant. Knees with medial femoral subchondral bone sclerosis (radiography), medial denuded subchondral bone areas (MRI), and low cartilage thickness (MRI) at baseline displayed significantly higher cartilage loss than those without, both with and without adjusting for age, sex, and BMI. Participants with denuded subchondral bone showed a standardized response mean of up to -0.64 versus -0.33 for the entire subcohort.
  
  
  CONCLUSIONS
  The results indicate that radiographic and MRI cartilage morphometry features suggestive of advanced disease appear to be associated with greater cartilage loss. These features may be suited for selecting patients with a higher likelihood of fast progression in studies that attempt to demonstrate the cartilage-preserving effect of disease-modifying osteoarthritis drugs.
authors.affiliation: Institute of Anatomy and Musculoskeletal Research, Paracelsus Medical University, A5020 Salzburg, Austria. felix.eckstein@pmu.ac.at
authors.forename: Felix
authors.initials: F
authors.lastname: Eckstein
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wirth
authors.forename: Martin I
authors.initials: MI
authors.lastname: Hudelmaier
authors.forename: Susanne
authors.initials: S
authors.lastname: Maschek
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hitzl
authors.forename: Bradley T
authors.initials: BT
authors.lastname: Wyman
authors.forename: Michael
authors.initials: M
authors.lastname: Nevitt
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Hellio Le Graverand
authors.forename: David
authors.initials: D
authors.lastname: Hunter
mesh_terms: D000368:Aged; D002358:Cartilage, Articular / Q000473:pathology*; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000453:epidemiology / Q000473:pathology*; D010020:Osteonecrosis / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D011446:Prospective Studies; D012307:Risk Factors