title: Association between clinical and sonographic synovitis in patients with painful knee osteoarthritis.
abstract: OBJECTIVE
  To evaluate the association between ultrasonographic findings of inflammation (effusion, synovitis) and clinical findings in patients with primary painful knee osteoarthritis.
  
  
  METHODS
  This cross-sectional study was performed on 142 patients with primary painful knee osteoarthritis (American College of Rheumatology criteria) in whom the visual analogue scale of pain was 30 or more. Clinical parameters were evaluated by a rheumatologist using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score while the ultrasonographic examination was performed by a musculoskeletal radiologist in our center. Knee joint synovitis and effusion were defined as synovial thickness ≥ 4 mm and depth of fluid in the suprapatellar recess ≥ 4 mm, respectively.
  
  
  RESULTS
  Sixty-eight (47.9%) patients demonstrated neither synovitis nor effusion, 37 (26.1%) had only effusion, 11 (7.7%) had only synovitis and 26 (18.3%) had both effusion and synovitis in the ultrasonographic examination. There was significant association between ultrasonographic knee arthritis (defined as presence of synovitis or effusion) and WOMAC pain sub-score, WOMAC physical function sub-score and WOMAC total score. No significant association was noted between sonographic signs of arthritis and WOMAC joint stiffness sub-score. We also found significant correlation between ultrasonographic synovitis and WOMAC pain sub-score (P < 0.001), WOMAC physical function sub-score (P < 0.001) and total WOMAC score (P < 0.001).
  
  
  CONCLUSIONS
  This study revealed a positive correlation between ultrasonographic synovitis and total WOMAC score, WOMAC pain and physical function sub-score. There was no association between sonographic signs of arthritis and WOMAC joint stiffness sub-score.
authors.affiliation: Radiology Department, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Bita
authors.initials: B
authors.lastname: Abbasi
authors.affiliation: Vascular and Interventional Research Center, Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Pezeshki-Rad
authors.affiliation: Emergency Medicine Department, Edalatian Emergency Center, Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Akhavan
authors.affiliation: Rheuamtic Disease Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Sahebari
mesh_terms: D018771:Arthralgia / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D010147:Pain Measurement; D011237:Predictive Value of Tests; D015995:Prevalence; D013583:Synovial Membrane / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013585:Synovitis / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D014463:Ultrasonography
keywords: Western Ontario and McMaster Universities Osteoarthritis Index; osteoarthritis; synovial effusion; synovitis; ultrasonography