Mylène Jansen

KIDA performance in severe OA 223 11 Table 3 : Intra-observer results for the 3 groups Mean SDD CV (%) Severe OA (n=293) Severe OA 1 month (n=98) Mild OA (n=55) Severe OA (n=293) Severe OA 1 month (n=98) Mild OA (n=55) Severe OA (n=293) Severe OA 1 month (n=98) Mild OA (n=55) Bone density (all in mm Al eq) Femur mean lateral 33.0 32.6 28.6 0.61 0.41 1.08 0.9 0.6 1.9 Femur mean medial 37.3 36.8 29.8 0.65 0.45 0.84 0.9 0.6 1.4 Tibia mean lateral 33.7 32.9 29.6 2.76 2.35 1.06 4.2 3.6 1.8 Tibia mean medial 38.6 38.2 31.3 0.98 0.69 0.84 1.3 0.9 1.4 JSW (all in mm) Mean 5.2 5.3 5.1 1.16 0.76 0.86 11.3 7.4 8.6 Mean lateral 7.7 7.7 6.1 2.02 1.43 1.53 13.4 9.5 12.8 Mean medial 2.7 2.9 4.2 0.76 0.47 0.67 14.4 8.3 8.1 Minimum 1.0 1.0 2.8 0.88 0.61 0.49 45.0 31.0 8.9 Osteophytes (all in mm 2 ) Femur lateral 7.6 8.6 5.4 10.31 5.35 6.78 69.2 31.7 64.1 Femur medial 7.1 11.1 3.7 13.41 11.15 3.21 96.3 51.3 44.3 Tibia lateral 10.0 11.8 6.4 9.35 11.56 8.06 47.7 50.0 64.2 Tibia medial 7.6 8.5 9.9 12.23 10.94 4.63 82.1 65.6 23.8 Other (mm, mm, degrees) Eminence lateral 12.5 12.7 10.0 2.21 2.23 2.47 9.0 9.0 12.6 Eminence medial 13.3 13.3 11.6 1.84 1.74 1.92 7.1 6.7 8.4 Joint angle* 6.4 6.3 3.0 2.35 1.86 2.02 18.8 15.1 34.3 *The joint angle here was defined as the absolute value (negative angles as a result of medial narrowing were taken as a positive value), as this was done in the original publication. CV: coefficient of variation (standard deviation of the differences between observations divided by the mean value of both observations and multiplied by 100); SDD: smallest detectable difference (1.96*standard deviation of mean differences between the 2 observations); mm Al eq: mm aluminum equivalent. Comparison with Kellgren-Lawrence grade The relation between all individual KIDA parameters and KL-grade are shown in Table 4. A smaller JSW and especially higher osteophytes were significantly associated with a higher KL- grade, as would be expected. A higher bone density in the medial femur showed a significant positive relation with KL-grade as well.