Table 3.
Adjusted mean values of patellofemoral WORMS subscores at baseline and their change over 48-month as well as prevalence and progression rates of structural abnormalities in subjects with versus without SPFP signal alteration at baseline
| Time point | Parameter | Subjects with SPFP signal alteration* | Controls without SPFP signal alteration* | P value*; odds ratio (OR [95% confidence intervals] from logistic regressions) |
|---|---|---|---|---|
| Baseline | WORMS patellar cartilage (mean, 95% confidence interval [CI]) | 1.99 [1.26, 2.72] | 1.72 [1.08, 2.36] | 0.092 |
| WORMS trochlea cartilage (mean, 95% CI) | 1.11 [0.54, 1.67] | 0.98 [0.41, 1.53] | 0.236 | |
| WORMS patellar BML (mean, 95% CI) | 0.54 [0.09, 0.98] | 0.52 [0.08, 0.97] | 0.871 | |
| WORMS trochlea BML (mean, 95% CI) | 0.27 [−0.07, 0.62] | 0.16 [−0.19, 0.50] | 0.080 | |
| WORMS patellar subchondral cysts (mean, 95% CI) | 0.24 [−0.01, 0.49] | 0.20 [−0.05, 0.45] | 0.361 | |
| WORMS trochlea subchondral cysts (mean, 95% CI) | 0.14 [−0.08, 0.35] | 0.09 [−0.16, 0.34] | 0.063 | |
| WORMS patellofemoral joint1 (mean, 95% CI) | 3.81 [1.69, 5.93] | 3.42 [1.78, 5.05] | 0.060 | |
| Partial-thickness cartilage defect present (WORMS 2, 3, 4; n; % of subgroup) | 114 (52.5%) | 97 (46.4%) | 0.215 | |
| Full-thickness cartilage defect present (WORMS 2.5, 5, 6; n; % of subgroup) | 16 (7.4%) | 14 (6.7%) | 0.795 | |
| Change over 48 months | Delta WORMS patellar cartilage (mean, 95% CI) | 0.29 [−0.07, 0.64] | −0.04 [−0.40, 0.31] | <0.001 |
| Delta WORMS trochlea cartilage (mean, 95% CI) | 0.47 [0.16, 0.77] | 0.31 [0.01, 0.61] | 0.007 | |
| Delta WORMS patellar BML (mean, 95% CI) | 0.11 [−0.24, 0.46] | 0.01 [−0.34, 0.36] | 0.135 | |
| Delta WORMS trochlea BML (mean, 95% CI) | 0.18 [−0.11, 0.47] | 0.13 [−0.15, 0.42] | 0.416 | |
| Delta WORMS patellar subchondral cysts (mean, 95% CI) | −0.04 [−0.29, 0.22] | −0.06 [−0.31, 0.20] | 0.708 | |
| Delta WORMS trochlea subchondral cysts (mean, 95% CI) | 0.21 [−0.02, 0.43] | 0.18 [−0.04, 0.40] | 0.556 | |
| Delta total WORMS patellofemoral joint (mean, 95% CI) | 1.21 [0.34, 2.08] | 0.53 [−0.34, 1.40] | <0.001 | |
| Progression of WORMS cartilage1 (n; %) | 98 (45.2%) | 44 (21.1%) | <0.001 (OR 3.71 [2.33, 5.90]) | |
| Progression of WORMS BML1 (n; %) | 62 (28.6%) | 38 (18.2%) | 0.021 (OR 1.75 [1.09, 2.82]) | |
| Progression of total WORMS patellofemoral joint1,2 (n; %) | 121 (55.8%) | 64 (30.6%) | <0.001 (OR 3.58 [2.30, 5.56]) |
Estimated marginal means for numerical outcome variables and P-values from general linear models; odds ratios for binary outcome variables and P-values from logistic regressions. All models adjusted for presence of mass effect and patella malalignment parameters, age, sex, BMI, KL and OAI cohort affiliation at baseline.
Progression indicating any difference of WORMS subscores larger than 0 between 48 months and baseline either in the patella or trochlea, or both.
Composed of subscores for cartilage, BML, and subchondral cysts in the patella and trochlea.