Mylène Jansen

MRI cartilage thickness after KJD and HTO 283 14 Figure 2 : Two-year change in radiographic and MRI cartilage parameters. (A) Change in MRI mean cartilage thickness over the total subchondral bone area (ThCtAB) of the more affected compartment (MAC), for the 3 groups: KJD HTO : KJD patients with indication high tibial osteotomy (HTO); KJD TKA : knee joint distraction (KJD) patients with indication total knee arthroplasty. (B) Change in MRI percentage of denuded subchondral bone area (dABp) of the MAC for the 3 groups. (C) Change in mean radiographic joint space width (JSW) of the MAC for the 3 groups. Markers represent individual patients, dashes represent the group mean and 95% confidence interval. Hashes (#) between groups indicate statistically significant differences between each 2 groups ( p< 0.05), corrected for baseline patient characteristics statistically significantly different between each 2 groups. Differences in cartilage structural change over time between KJD HTO and HTO and between KJD HTO and KJD TKA did not reach statistical significance for any of the 3 MAC parameters (Table 2). Between KJD TKA and HTO, both the cartilage thickness and denuded bone area showed large, statistically significant differences, while the radiographic JSW did not. Correcting the between-group comparisons for baseline cartilage thickness, denuded bone area, or JSW values did not change significance for any of the comparisons in all 3 parameters. The MRI field strength (1.5T or 3T) did not have a significant influence on the change in MAC cartilage thickness or denuded bone area in any of the 3 patient groups (all p> 0.3). In the LAC, most groups did not show a significant change in any of the 3 parameters (cartilage thickness, denuded bone area, and JSW), except for the KJD HTO group that showed a significant (but small) increase in LAC denude bone area (Table 2). Subregional cartilage thickness changes and location-independent cartilage thinning and thickening scores are shown in the supplementary data.