title: Total Knee Replacement as a Knee Osteoarthritis Outcome: Predictors Derived from a 4-Year Long-Term Observation following a Randomized Clinical Trial Using Chondroitin Sulfate.
abstract: OBJECTIVE
  To predict, using clinical and qMRI data, the incidence of total knee replacement (TKR) during the long-term follow-up of knee osteoarthritis (OA) patients who formerly received chondroitin sulfate (CS) or placebo treatment.
  
  
  METHODS
  A post hoc intention-to-treat analysis to evaluate the incidence of TKR was done on knee OA patients who had participated in a 12-month trial evaluating the impact of CS (800 mg/d) versus placebo for 6 months, followed by a 6-month open-phase in which all patients received CS. Additionally, the clinical and qMRI predictors of TKR were determined.
  
  
  RESULTS
  Thirteen TKRs were performed in the population after a 4-year follow-up. More TKRs were performed in the placebo group than in the CS group (69% vs. 31%, P = 0.150, logistic regression). The statistically significant predictors of TKRs were, at baseline, higher WOMAC pain and function scores, presence of bone marrow lesions (BMLs), and higher C-reactive protein levels. Loss of medial cartilage volume and increase in WOMAC pain and function at one-year were also predictors of TKR. Multivariate analyses revealed that baseline presence of BML and higher WOMAC pain score were independent predictors. Time to occurrence of the TKR also favored the CS group versus placebo (log-rank, P = 0.094).
  
  
  CONCLUSIONS
  Symptoms such as knee pain and function, presence of BML, and cartilage volume loss predict the long-term occurrence of a "hard" outcome such as TKR.
authors.affiliation: Osteoarthritis Research Unit, University of Montreal Hospital Research Centre, Montreal, Quebec, Canada.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Raynauld
authors.affiliation: Osteoarthritis Research Unit, University of Montreal Hospital Research Centre, Montreal, Quebec, Canada.
authors.forename: Johanne
authors.initials: J
authors.lastname: Martel-Pelletier
authors.affiliation: StatSciences Inc., Notre-Dame de l'Île-Perrot, Quebec, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Dorais
authors.affiliation: Osteoarthritis Research Unit, University of Montreal Hospital Research Centre, Montreal, Quebec, Canada.
authors.forename: Boulos
authors.initials: B
authors.lastname: Haraoui
authors.affiliation: Osteoarthritis Research Unit, University of Montreal Hospital Research Centre, Montreal, Quebec, Canada.
authors.forename: Denis
authors.initials: D
authors.lastname: Choquette
authors.affiliation: Imaging Research & Development, ArthroLab Inc., Montreal, Quebec, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Abram
authors.affiliation: Faculty of Medicine, Laval University, Quebec City, Quebec, Canada.
authors.forename: André
authors.initials: A
authors.lastname: Beaulieu
authors.affiliation: Groupe de Recherche en Rhumatologie et Maladies Osseuses, Sainte-Foy, Quebec, Canada.
authors.forename: Louis
authors.initials: L
authors.lastname: Bessette
authors.affiliation: Centre de Recherche Musculo-squelettique, Trois-Rivières, Quebec, Canada.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Morin
authors.affiliation: Osteoarthritis Research Unit, University of Montreal Hospital Research Centre, Montreal, Quebec, Canada.
authors.forename: Lukas M
authors.initials: LM
authors.lastname: Wildi
authors.affiliation: Osteoarthritis Research Unit, University of Montreal Hospital Research Centre, Montreal, Quebec, Canada.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Pelletier
keywords: MRI; chondroitin sulfate; knee osteoarthritis; knee replacement