title: Presence of MRI-detected joint effusion and synovitis increases the risk of cartilage loss in knees without osteoarthritis at 30-month follow-up: the MOST study.
abstract: OBJECTIVE
  To evaluate if two different measures of synovial activation, baseline Hoffa synovitis and effusion synovitis, assessed by MRI, predict cartilage loss in the tibiofemoral joint at 30 months follow-up in subjects with neither cartilage damage nor tibiofemoral radiographic osteoarthritis of the knee.
  
  
  METHODS
  Non-contrast-enhanced MRI was performed using proton density-weighted fat-suppressed sequences in the axial and sagittal planes and a short tau inversion recovery sequence in the coronal plane. Hoffa synovitis, effusion synovitis and cartilage status were assessed semiquantitatively according to the WORMS scoring system. Included were knees that had neither radiographic osteoarthritis nor MRI-detected tibiofemoral cartilage damage at the baseline visit. The presence of Hoffa synovitis was defined as any grade ≥ 2 (range 0-3) and effusion synovitis as any grade ≥ 2 (range 0-3). Logistic regression was performed to examine the relation of the presence of either measure to the risk of cartilage loss at 30 months adjusting for other potential confounders.
  
  
  RESULTS
  Of 514 knees included in the analysis, the prevalence of Hoffa synovitis and effusion synovitis at the baseline visit was 8.4% and 10.3%, respectively. In the multivariable analysis, baseline effusion synovitis was associated with an increased risk of cartilage loss. No such association was observed for baseline Hoffa synovitis.
  
  
  CONCLUSIONS
  Baseline effusion synovitis, but not Hoffa synovitis, predicted cartilage loss. The findings suggest that effusion synovitis, a reflection of inflammatory activity including joint effusion and synovitic thickening, may play a role in the future development of cartilage lesions in knees without osteoarthritis.
authors.affiliation: Department of Radiology, Boston University Medical Center, FGH Building, 3rd floor, 820 Harrison Avenue, Boston, MA 02118, USA. froemer@bu.edu
authors.forename: Frank W
authors.initials: FW
authors.lastname: Roemer
authors.forename: Ali
authors.initials: A
authors.lastname: Guermazi
authors.forename: David T
authors.initials: DT
authors.lastname: Felson
authors.forename: Jingbo
authors.initials: J
authors.lastname: Niu
authors.forename: Michael C
authors.initials: MC
authors.lastname: Nevitt
authors.forename: Michel D
authors.initials: MD
authors.lastname: Crema
authors.forename: John A
authors.initials: JA
authors.lastname: Lynch
authors.forename: Cora E
authors.initials: CE
authors.lastname: Lewis
authors.forename: James
authors.initials: J
authors.lastname: Torner
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000368:Aged; D002358:Cartilage, Articular / Q000473:pathology*; D018450:Disease Progression; D005122:Exudates and Transudates / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000378:metabolism / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology; D013585:Synovitis / Q000378:metabolism / Q000473:pathology*