Table 3.
Cartilage worsening: adjusted risk ratio per degree (or per percentage) of exposure variable (alignment or morphology at one year)
| Patellofemoral joint | Lateral | Medial | |
|---|---|---|---|
| Number of subregions with worsening | 70/584 | 22/292 | 48/292 |
| Insall Salvati ratio × 100* (%) | 0.99 (0.96, 1.02) | 0.99 (0.95, 1.02) | 1.00 (0.96, 1.03) |
| Bisect offset (%) | 1.03 (0.98, 1.09) | 1.09 (1.01, 1.16) | 1.01 (0.96, 1.07) |
| ≥ 61.6%^ | 1.26 (0.51, 3.10) | 2.43 (0.91, 6.50) | 0.81 (0.28, 2.34) |
| Lateral patellar tilt angle (°) | 0.95 (0.90, 1.01) | 0.91 (0.83, 0.99) | 0.97 (0.91, 1.04) |
| ≤ 12.3°^ | 1.53 (0.73, 3.20) | 2.87 (0.95, 8.65) | 1.19 (0.54, 2.64) |
| Patellar tilt angle (°) | 1.03 (0.96, 1.09) | 1.06 (0.97, 1.15) | 1.01 (0.94, 1.09) |
| Sulcus angle (°) | 0.98 (0.94, 1.03) | 0.99 (0.93, 1.04) | 0.98 (0.94, 1.03) |
| Lateral trochlear inclination (°) | 1.02 (0.95, 1.08) | 0.98 (0.90, 1.07) | 1.03 1.11) |
| Medial trochlear inclination (°) | 1.02 (0.97, 1.08) | 1.05 (0.97, 1.13) | 1.01 (0.96, 1.07) |
| Trochlear angle (°) | 0.97 (0.86, 1.09) | 0.88 (0.77, 1.00) | 1.02 (0.88, 1.17) |
| Trochlear depth (mm) | 1.14 (0.86, 1.52) | 1.15 (0.79, 1.68) | 1.14 (0.83, 1.55) |
Age was included as a covariate in all models. Note analyses are all subregion-based, thus sample size for each model includes sample size (n=73) times the number of subregions (4 for full patellofemoral joint, 2 each for lateral and medial) times the number of MOAKS scores included (2, cartilage damage size and percentage that is full-thickness). Bold indicates p < 0.05
Insall-Salvati Ratio was transformed to for analyses in order to calculate a risk ratio that could be clinically interpreted per point difference in ratio (a risk ratio in a change in Insall-Salvati Ratio of 1 is not meaningful)
Dichotomized exposure variables: only measures where at least 10% of the sample exceeded reference values were analysed as both continuous and dichotomous exposure variables and are reported here