Table 3.
Results of longitudinal analyses for primary and exploratory outcome parameters between groups
| Parameters | The rates of change over 8 years | Differences on average over 8 years | ||
|---|---|---|---|---|
| Effect size (95% CI)a | Pi value | Effect size (95% CI)b | Pa value | |
| Primary outcome parameters | ||||
| Regular T2 values | ||||
| T2 global* | 0.005 (−0.011, 0.022) | 0.523 | 0.13 (−0.90, 1.15) | 0.809 |
| Laminar T2 values | ||||
| Global bone layer T2 | 0.006 (−0.009, 0.022) | 0.411 | 0.20 (−0.72, 1.12) | 0.669 |
| Global articular layer T2 | 0.005 (−0.014, 0.024) | 0.620 | 0.89 (−0.41, 2.19) | 0.180 |
| Texture parameters | ||||
| Global knee contrast* | −0.072 (−0.108, − 0.035) | 0.000 | ||
| Global knee variance* | −0.031 (− 0.050, − 0.013) | 0.001 | ||
| Global knee entropy* | −0.001 (− 0.004, 0.002) | 0.460 | 0.09 (0.00, 0.19) | 0.047 |
| Exploratory outcome parameters | ||||
| WORMS scores | ||||
| Cartilage sum score | 0.012 (−0.008, 0.032) | 0.248 | −1.04 (−2.61, 0.53) | 0.194 |
| Meniscus sum score | 0.004 (−0.008, 0.015) | 0.514 | −0.79 (− 2.31, 0.74) | 0.313 |
| BMEPs sum score | 0.004 (−0.006, 0.015) | 0.437 | −0.89 (−2.21, 0.43) | 0.188 |
| Subchondral cysts sum score | 0.001 (−0.009, 0.012) | 0.788 | −1.51 (−2.47, − 0.55) | 0.002 |
| Effusion score | 0.000 (−0.003, 0.003) | 0.865 | 0.24 (0.10, 0.38) | 0.001 |
| Ligament sum score* | −0.001 (− 0.007, 0.004) | 0.610 | − 0.16 (− 0.65, 0.34) | 0.534 |
| IPFP and SPFP signal abnormalities | ||||
| IPFP signal abnormalities (size) | −0.007 (− 0.011, − 0.003) | 0.001 | ||
| IPFP signal abnormalities (SI) | −0.006 (− 0.011, − 0.002) | 0.010 | ||
| SPFP signal abnormalities (SI)* | −0.004 (− 0.007, − 0.000) | 0.030 | ||
*Parameters that had a non-linear change over 8 years. aEffect size for the rates of change over 8 years between groups, with (95% confidence intervals, CI) provided. bEffect size for the differences on average over 8 years between groups, with (95% confidence intervals) provided. Effect size were corrected for age, sex, race and baseline BMI and K&L grades. Pi values < 0.05 were in bold, indicating significant interactions with time. Pa values < 0.05 were in bold, indicating significant differences on average over 8 years. BMEP bone marrow edema pattern, IPFP infrapatellar fat pad, SPFP suprapatellar fat pad, SI signal intensity