title: Changes in structure and symptoms in knee osteoarthritis and prediction of future knee replacement over 8 years.
abstract: The objective of this study was to assess the association between changes in joint space width (JSW, i.e., structure) or Western Ontario and McMaster Universities (WOMAC) score (i.e., symptoms) over 3 years in patients with knee osteoarthritis and the occurrence of knee replacement over 8 years. We followed 133 subjects with primary knee osteoarthritis prospectively for a mean of 8 years. JSW (standard radiography) and symptoms (total WOMAC score) were assessed every year for 3 years. The rate of knee replacement was recorded for the following 5 years. Logistic regressions were performed according to the intention-to-treat principle. After 8 years' follow-up, ten patients (7.5 %) had undergone a knee replacement. The changes in JSW or WOMAC score over 3 years were significantly associated with the occurrence of knee replacement during the following 5 years (p = 0.02 and p = 0.03, respectively). Each 0.1-mm narrowing of JSW over 3 years was associated with a 14 % (95 % CI 3-25 %) increased risk for knee replacement. For every 10 % increase in WOMAC score, the risk for joint replacement was increased by 16 % (95 % CI 1-33 %). When JSW and WOMAC score were included in the same statistical model, they were still significantly associated with risk for knee replacement (p = 0.02 and p = 0.03, respectively), but JSW change was the only variable that remained significant after adjusting for all potential confounders. Our results suggest that changes in symptoms and, more particularly, in structure over 3 years in patients with osteoarthritis reflect a clinically relevant progression of the disease.
authors.affiliation: Department of Public Health, Epidemiology and Health Economics, University of Liège, CHU Sart-Tilman, Bât B23, 4000, Liège, Belgium, olivier.bruyere@ulg.ac.be.
authors.forename: Olivier
authors.initials: O
authors.lastname: Bruyere
authors.forename: Cyrus
authors.initials: C
authors.lastname: Cooper
authors.forename: Karel
authors.initials: K
authors.lastname: Pavelka
authors.forename: Véronique
authors.initials: V
authors.lastname: Rabenda
authors.forename: Fanny
authors.initials: F
authors.lastname: Buckinx
authors.forename: Charlotte
authors.initials: C
authors.lastname: Beaudart
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Reginster
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D015992:Body Mass Index; D018450:Disease Progression; D004311:Double-Blind Method; D005260:Female; D005269:Femur / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D011379:Prognosis; D011446:Prospective Studies; D011859:Radiography; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013977:Tibia / Q000473:pathology