title: Quantitative microfocal radiography detects changes in OA knee joint space width in patients in placebo controlled trial of NSAID therapy.
abstract: OBJECTIVE
  To assess the usefulness of, and define the time course of changes in the features of osteoarthritic (OA) knees measurable using microfocal radiography, and to determine whether it differs in patients taking a nonsteroidal antiinflammatory drug (NSAID).
  
  
  METHODS
  Forty-five patients with knee OA were randomly allocated to receive either diclofenac sodium or placebo for 18 months; 33 (17 NSAID, 16 placebo) completed the study. Clinical and 5 x high definition macroradiographic assessments of both knees in standing semiflexed views were carried out at 6-monthly intervals. Precise measurements were taken of the tibial and femoral subchondral thickness and osteophyte size, and of joint space width (JSW) across the narrowest part of the medial and lateral tibiofemoral compartments.
  
  
  RESULTS
  In all knees as a group, there was no statistically significant difference in JSW between treatment groups. However, changes in JSW were significantly different (p < 0.04, multivariate analysis of variance) between treatments in 51 knees with early disease, i.e., those with initially > 50% JSW (22 active, 29 placebo), but not in 15 knees with severe disease, i.e., initially < 50% JSW (10 active, 5 placebo). During the study, osteophyte size in all knees and in those with > 50% JSW increased significantly (p < 0.016; p < 0.008) in the placebo group but remained unchanged in the treatment group. No significant changes were detected in subchondral cortical thickness.
  
  
  CONCLUSIONS
  Using microfocal radiography the time course of changes in JSW and osteophyte size of knees with early, but not late OA, was found to differ in both pattern and magnitude in patients receiving NSAID: In knees with late stage OA the JSW progressively decreased irrespective of treatment. The observations may prove useful for the design of future therapeutic trials.
authors.affiliation: Division of Anatomy and Cell Biology, UMDS Guy's Hospital, London, UK.
authors.forename: J C
authors.initials: JC
authors.lastname: Buckland-Wright
authors.forename: D G
authors.initials: DG
authors.lastname: MacFarlane
authors.forename: J A
authors.initials: JA
authors.lastname: Lynch
authors.forename: M K
authors.initials: MK
authors.lastname: Jasani
mesh_terms: D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D001175:Arthrography / Q000379:methods*; D018450:Disease Progression; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000187:drug effects; D008297:Male; D008852:Microradiography; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D010147:Pain Measurement; D010919:Placebos; D013997:Time Factors
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D010919:Placebos