Table 2. Comparison between grade 3 and grade 4 osteoarthritis and control for various parameters and their p-value.
*Kruskal-Wallis test, df = 2
MMP-13, matrix metalloproteinase 13; χ2, chi-square; df, degrees of freedom
| Parameter | Grade 3 (n = 25) (mean ± SD) | Grade 4 (n = 25) (mean ± SD) | Control (n = 50) (mean ± SD) | χ2 | P-value* |
| Synovial MMP-13 (pg/mL) | 186.2 ± 78.2 | 238.2 ± 93.5 | 79.3 ± 29.4 | 45.508 | <0.001 |
| Serum MMP-13 (pg/mL) | 117.6 ± 40.8 | 89.6 ± 36.2 | 49.1 ± 24.6 | 45.237 | <0.001 |
| Serum vitamin D (ng/mL) | 11.4 ± 3.2 | 11.9 ± 4.0 | 20.4 ± 6.0 | 13.662 | <0.001 |