Figure 2From: Is knee osteoarthritis a symmetrical disease? Analysis of a 12 year prospective cohort study Percentage of subjects with no radiographic change, unilateral and bilateral changes at each time point. Error bars represent 95% confidence intervals. The term ‘No OA’ refers to subjects with no evidence of disease in either knee. a) using a definition of KL ≥ 1 for osteoarthritis. b) using a definition of KL ≥ 2 for osteoarthritis.Back to article page