title: Bone marrow lesions and joint effusion are strongly and independently associated with weight-bearing pain in knee osteoarthritis: data from the osteoarthritis initiative.
abstract: OBJECTIVE
  It is widely believed that there are multiple sources of pain at a tissue level in osteoarthritis (OA). Magnetic Resonance Images (MRIs) provide a wealth of anatomic information and may allow identification of specific features associated with pain. We hypothesized that in knees with OA, bone marrow lesions (BMLs), synovitis, and effusion would be associated with weight-bearing and (less so with) non-weight-bearing pain independently.
  
  
  METHODS
  In a cross-sectional study of persons with symptomatic knee OA using univariate and multivariate logistic regressions with maximal BML, effusion, and synovitis defined by Boston Leeds Osteoarthritis Knee Score as predictors, and knee pain using weight-bearing and non-weight-bearing Western Ontario and McMaster University OA Index pain questions as the outcome, we tested the association between MRI findings and knee symptoms.
  
  
  RESULTS
  160 participants, mean age 61 (+/-9.9), mean body mass index (BMI) 30.3 (+/-4.7) and 50% female, stronger associations were seen with weight-bearing compared with non-weight-bearing knee pain with adjusted risk ratios (RRs) of weight-bearing knee pain, for increasing maximal BML scores of 1.0 (referent) (maximal BML=0), 1.2, 1.9, and 2.0 (P for trend=0.006). For effusion scores, adjusted RRs of knee pain were 1.0, 1.7, 2.0, and 2.6 (P for trend=0.0004); and for synovitis scores, adjusted ORs were 1.0, 1.4, 1.5, and 1.9 (P for trend=0.22).
  
  
  CONCLUSIONS
  Cross-sectionally, maximal BML and effusion scores are independently associated with weight-bearing and less so with non-weight-bearing knee pain, supporting the idea that pain in OA is multifactorial. These MRI features should be considered as possible new treatment targets in knee OA.
authors: Tufts Medical Center, Boston, MA 02111, United States. glo@tuftsmedicalcenter.org
authors: G H
authors: GH
authors: Lo
authors: T E
authors: TE
authors: McAlindon
authors: J
authors: J
authors: Niu
authors: Y
authors: Y
authors: Zhang
authors: C
authors: C
authors: Beals
authors: C
authors: C
authors: Dabrowski
authors: M P Hellio
authors: MP
authors: Le Graverand
authors: D J
authors: DJ
authors: Hunter
mesh_terms: D000368:Aged; D018771:Arthralgia / Q000175:diagnosis / Q000209:etiology*; D015992:Body Mass Index; D001855:Bone Marrow Diseases / Q000150:complications* / Q000175:diagnosis; D002358:Cartilage, Articular / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology*; D010147:Pain Measurement; D012720:Severity of Illness Index; D016474:Weight-Bearing / Q000502:physiology*