Mylène Jansen

358 Chapter 17 Table 2 : Baseline and 2-year WOMAC and JSW for the different patient groups KJD HTO CHECK Baseline 2 Years P- value Baseline 2 Years P- value Baseline 2 Years P- value Total WOMAC (0–100) 50.6 (15.7) 78.8 (19.3) <0.001 50.7 (14.6) 81.5 (14.5) <0.001 58.6 (15.9) 51.8 (20.3) 0.035 JSW (mm) 2.36 (1.73) 3.03 (1.57) <0.001 2.24 (1.28) 2.56 (1.37) 0.034 3.18 (1.76) 2.52 (1.72) <0.001 Mean and standard deviation are given. P- values are calculated for 2-year changes with paired t -tests; bold p- values indicate statistical significance. CHECK: Cohort Hip & Cohort Knee; HTO: high tibial osteotomy; JSW: joint space width (mean JSW of the most affected compartment is shown); KJD: knee joint distraction; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index (scale 0–100). The total osteophyte size showed a statistically significant increase after treatment ( p= 0.003), from 40.9 (SD 28.0) mm 2 at baseline to 47.1 (28.1) mm 2 at 2 years, as shown in Figure 1A. Only the lateral femur showed a significant increase (from 9.1 (9.4) mm 2 to 11.9 (9.8) mm 2 ; p< 0.001), the other compartments did not (all p≥0.19; Figure 1B). A representative radiograph of a patient before and 2 years after KJD treatment is shown in Figure 2. Figure 1 : Change in osteophyte size inmm 2 before and 1 and 2 years after treatment with knee joint distraction (KJD) or high tibial osteotomy (HTO). (A) The total joint osteophyte area and (B) the osteophyte area per compartment after KJD. (C) Total joint osteophyte area after KJD or HTO and (D) osteophyte area per compartment after HTO. Mean and standard error of the mean (SEM) are shown, * indicates significant changes compared to baseline using repeated measures ANOVA ( p< 0.05).