title: Associations between pain, function, and radiographic features in osteoarthritis of the knee.
abstract: OBJECTIVE
  To assess the associations between pain, loss of function, and radiographic changes in knee osteoarthritis (OA), taking into account both the patellofemoral and tibiofemoral compartments.
  
  
  METHODS
  Both knees of 167 community-based patients with OA in at least 1 of their knees were assessed. Pain was measured by visual analog scale, and function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index. Anteroposterior standing radiographs with the knee in extension and lateral 30 degrees flexion were obtained and assessed for the Kellgren/Lawrence score and for individual features (osteophytes, joint space narrowing, and subchondral bone sclerosis) in each compartment.
  
  
  RESULTS
  Knees with structural changes in both compartments were more likely to be painful and to be associated with loss of function than were knees in which only 1 compartment was affected. The individual feature most strongly associated with pain was subchondral bone sclerosis.
  
  
  CONCLUSIONS
  Studies exploring the associations between structural and symptomatic knee OA need to include an assessment of the patellofemoral compartment, and individual radiographic features rather than a global severity score should be considered in these studies.
authors.affiliation: Academc Rheumatology, Department of Clinical Science at North Bristol, University of Bristol, Avon Orthopaedic Centre, Southmead Hospital, Bristol BS10 5NB, UK. b.szebenyi@bristol.ac.uk
authors.forename: Béla
authors.initials: B
authors.lastname: Szebenyi
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Hollander
authors.forename: Paul
authors.initials: P
authors.lastname: Dieppe
authors.forename: Brian
authors.initials: B
authors.lastname: Quilty
authors.forename: John
authors.initials: J
authors.lastname: Duddy
authors.forename: Shane
authors.initials: S
authors.lastname: Clarke
authors.forename: John R
authors.initials: JR
authors.lastname: Kirwan
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D020370:Osteoarthritis, Knee / Q000150:complications* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D010146:Pain / Q000209:etiology*; D011859:Radiography