Predictors of self-reported knee instability among patients with knee osteoarthritis: results of the Amsterdam osteoarthritis cohort.

Abstract

The aims of the study were to (i) determine the prevalence and course of self-reported knee instability at 2-year follow-up and (ii) identify factors predictive of retention of self-reported knee instability among patients with established knee osteoarthritis (OA). Among 201 patients from the Amsterdam Osteoarthritis (AMS-OA) cohort, demographic characteristics, self-reported knee instability, muscle strength, proprioception, pain, and physical function were assessed at baseline and at 2years. Exercise over the past 2years was assessed by evaluating the medical files. The course of self-reported knee instability was determined in patients reporting instability at baseline. Baseline predictors of self-reported knee instability were determined by uni- and multivariable logistic regression analyses. At baseline, 123 (61%) patients reported knee instability, and of these, 85 (64%) patients reported instability 2years later, while 38 (29%) reported no instability 2years later. Poor proprioception and high pain assessed at baseline predicted retention of self-reported knee instability at 2years among patients with self-reported instability at baseline. Knee instability is highly prevalent among patients with knee osteoarthritis. In patients with self-reported knee instability, the majority retained instability over 2years. Poor proprioception and high pain predicted retention of self-reported knee instability over time.