| C group | D group | P value |
---|---|---|---|
Before surgery | −0.01 ±  0.02 | − 0.009 ± 0.04 | 0.073 |
3 months postoperatively | 0.69 ± 0.05 | 0.55 ± 0.13 | <0.001 |
6 months postoperatively | 0.84 ± 0.10 | 0.75 ± 0.14 | <0.001 |
1 year postoperatively | 0.95 ± 0.07 | 0.92 ± 0.07 | 0.157 |