Mylène Jansen

Two-year results of KJD compared with HTO and TKA 71 4 KJD versus HTO In the KJD HTO group the minimum JSW increased from 0.49 (SEM 0.15) mm to 1.43 (0.23) mm ( p< 0.001) and the mean JSW increased from 1.99 (0.33) mm to 2.82 (0.32) mm ( p= 0.002). In the HTO group, the minimum and mean JSW increased from 0.57 (SEM 0.16) mm to 1.19 (0.21) mm ( p< 0.001) and from 1.91 (0.20) mm to 2.80 (0.23) mm ( p< 0.001), respectively. For the 2-year increase in both mean and minimum JSW, there was no statistically significant difference between the KJD HTO and HTO groups (both p> 0.232; Table 3). Biochemical marker analyses In the KJD patients, normalized biochemical marker Z-scores showed a significant initial increase in collagen type II degradation marker CTXII, at 3 ( p< 0.001) and 12 ( p= 0.020) months, and a longer-term increase in collagen type II synthesis marker PIIANP at 12 ( p= 0.008) and 24 ( p< 0.001) months. The Z-index, indicating normalized net collagen type II synthesis, was statistically significantly decreased at 3 months (Δ-0.43 (SEM 0.20); p= 0.035) and statistically significantly increased at 24 months (Δ0.59 (0.18); p= 0.003) with respect to baseline, as shown in Figure 4. In these analyses, 16 of 452 measurements were excluded as outliers (15 points above 95%CI, 1 point below 95%CI). The sensitivity analysis including these outliers resulted in a loss of statistical significance only at 3 months ( p= 0.231), the 24 months normalized increase of synthesis over breakdown remained statistically significant ( p= 0.002). Performing the same analyses in the 2 KJD patient groups separately showed a similar pattern for both groups, although the differences from baseline were not statistically significant. Figure 4 : Collagen type II. Normalized biomarker Z-index over 2 years for all knee joint distraction (KJD) patients combined, expressing net collagen type II synthesis (Z index = Z PIIANP – Z CTXII ). Mean values ± standard error of the mean are shown. Statistically significant changes ( p< 0.05) compared to baseline are indicated with *.