Table 2.
Mean (standard deviation) values of the selected variables among controls, subjects with radiographic OA but no medial tibial BMLs, and subjects with medial tibial BMLs.
| Variable | Group 0: Controls (n = 52) | Group 1: OA, no medial tibial BML (n = 30) | Group 2: Medial tibial BML (n = 23) | p value |
|---|---|---|---|---|
| Age (years) | 56.4 (6.3)2 | 58.3 (5.5) | 60.8 (4.4) | 0.019a |
| Body mass index (kg/m2) | 25.0 (2.5)1,2 | 28.1 (3.8)2 | 30.9 (5.8) | < 0.001 |
| GVmmAl in medial SB (mmAl) | 26.9 (3.1)1,2 | 29.2 (4.7) | 29.6 (4.5) | 0.011a |
| GVmmAl in ROI6 (mmAl) | 25.0 (2.6)1,2 | 26.8 (3.4) | 26.8 (3.9) | 0.016 |
| GVmmAl in ROI7 (mmAl) | 20.1 (2.1)1,2 | 22.3 (2.9)2 | 24.0 (4.0) | < 0.001 |
| GVmmAl in ROI12 (mmAl) | 23.6 (2.4)1,2 | 25.4 (2.9) | 25.6 (3.7) | 0.006 |
| FDVer,0.30mm in medial SB | 2.65 (0.09)2 | 2.68 (0.08) | 2.71 (0.07) | < 0.001 |
| FDVer,0.30mm in ROI6 | 2.65 (0.08)2 | 2.66 (0.07) | 2.70 (0.06) | 0.028 |
| FDVer,0.30mm in ROI7 | 2.55 (0.06)2 | 2.57 (0.06)2 | 2.62 (0.06) | < 0.001a |
| FDVer,0.30mm in ROI12 | 2.70 (0.06)2 | 2.71 (0.06) | 2.74 (0.06) | 0.043 |
| FDVer,0.30mm in ROI15 | 2.70 (0.06)2 | 2.72 (0.08)2 | 2.74 (0.05) | 0.013a |
| FDVer,0.44mm in medial SB | 2.86 (0.09)1,2 | 2.90 (0.08)2 | 2.95 (0.08) | < 0.001 |
| FDVer,0.44mm in ROI7 | 2.76 (0.08)1,2 | 2.80 (0.09)2 | 2.85 (0.08) | < 0.001a |
| FDVer,0.59mm in medial SB | 2.90 (0.11)1,2 | 2.96 (0.12) | 3.01 (0.11) | < 0.001 |
| FDVer,0.59mm in ROI7 | 2.79 (0.11)1,2 | 2.85 (0.12)2 | 2.92 (0.12) | < 0.001 |
| FDVer,0.59mm in ROI12 | 3.14 (0.10)1,2 | 3.19 (0.12) | 3.20 (0.07) | 0.024 |
| FDVer,0.74mm in medial SB | 2.84 (0.11)2 | 2.90 (0.16)2 | 2.96 (0.13) | 0.002a |
| FDVer,0.74mm in ROI7 | 2.70 (0.15)1,2 | 2.77 (0.15) | 2.85 (0.17) | < 0.001 |
| FDVer,0.74mm in ROI12 | 3.08 (0.13)1,2 | 3.16 (0.13) | 3.17 (0.13) | 0.005 |
| FDHor,0.30mm in lateral SB | 2.52 (0.08)2 | 2.55 (0.10) | 2.57 (0.08) | 0.046 |
| FDHor,0.30mm in ROI7 | 2.57 (0.08)2 | 2.59 (0.08) | 2.62 (0.07) | 0.025 |
| FDHor,0.59mm in ROI2 | 2.96 (0.07) | 2.98 (0.05)2 | 2.93 (0.10) | 0.020 |
| FDHor,0.59mm in ROI3 | 2.98 (0.07)2 | 2.97 (0.07)2 | 2.91 (0.09) | < 0.001a |
| FDHor,0.74mm in ROI1 | 2.92 (0.06)2 | 2.92 (0.08)2 | 2.87 (0.08) | 0.013 |
| FDHor,0.74mm in ROI2 | 2.97 (0.08)2 | 2.98 (0.14)2 | 2.91 (0.14) | 0.040 |
| FDHor,0.74mm in ROI3 | 2.98 (0.07)2 | 2.97 (0.11)2 | 2.91 (0.11) | 0.004a |
| FDHor,0.74mm in ROI7 | 2.77 (0.08)2 | 2.75 (0.11)2 | 2.70 (0.11) | 0.012a |
Bone density and texture variables were measured from X-ray images with minimal post-processing
SB subchondral bone, ROI region of interest, GVmmAl mean grayscale value calibrated with aluminum step wedge, FD fractal dimension of vertical (Ver) or horizontal (Hor) structures, adifferences tested using Kruskal–Wallis test. Numbers in superscript means significant differences between groups without correction of p-values. Bolded numbers means significant differences between groups using Bonferroni post hoc test