Figure 1.

Panels show the longitudinal change of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score [28], WOMAC pain subscore [28], pain intensity [29] and quality of life (as assessed by the knee specific Knee injury and Osteoarthritis Outcome Score (KOOS) [27]) in the years 4–0 prior to total knee replacement (TKR) (surgery. Significance levels are indicated by n.s. (not significant) or *: p ≤ 0.05, ***: p ≤ 0.001, and represent the comparison to the previous year: 3 vs. 4, 2 vs. 3, 1 vs. 2 and 0 vs. 1.; yrs: years.