Mylène Jansen

298 Chapter 14 Longitudinal changes by baseline severity Sensitivity analyses Supplementary Table S1 : Sensitivity analyses for comparisons where patients were included in different trials KJD mild vs KJD severe KJD mild vs HTO mild KJD severe vs HTO severe Difference P Difference P Difference P MAC ThCtAB (mm) 0.42 (0.15 to 0.68) 0.003 0.09 (-0.08 to 0.27) 0.289 -0.31 (-0.59 to 0.03) 0.031 MAC dABp (%) -5.9 (-13.8 to 2.0) 0.139 -1.4 (-4.5 to 1.7) 0.351 7.5 (-0.8 to 15.9) 0.075 Mean MAC JSW (mm) 0.61 (-0.35 to -1.57) 0.204 0.48 (-0.03 to 1.00) 0.064 -0.16 (-1.11 to 0.80) 0.742 Differences are shown with mean and 95% confidence interval. Differences between groups and corresponding p- values were calculated with linear regression, correcting for statistically significantly different baseline characteristics and the trial in which patients were included; bold p- values indicate statistical significance ( p< 0.05). dABp: percentage of denuded subchondral bone area; HTO: high tibial osteotomy; JSW: joint space width; KJD HTO : knee joint distraction (KJD) patients with indication HTO; KJD TKA : KJD patients with indication total knee arthroplasty; LAC: least affected compartment; MAC: most affected compartment; ThCtAB: mean cartilage thickness over the total subchondral bone area. Supplementary discussion In KJD patients, the anterior region of the MAC tibia and the central and external regions of the MAC tibia and femur clearly showed the most substantial cartilage restoration. The baseline cartilage thickness in the central femur and external tibia and femur was much smaller than that of the other regions (≥40%; data not shown). This could explain the greater restoration in these 3 areas. In another MRI cartilage study, the anterior tibial region has been shown to be frequently involved in both thickening and thinning of cartilage. 36 Similarly, in another study, the central tibial and femoral regions showed a greater loss of cartilage than the other regions. 37 As such, the higher rate of cartilage restoration at the central, anterior, and external parts of the MAC may be the result of natural sensitivity to change.