Table 4 Comparison of ODI and JOA scores (\(\overline{x}\) ± s, points)

ODI

Before surgery

39.71 ± 4.39

39.37 ± 4.76

0.306

0.761

6 months after surgery

17.38 ± 2.18

23.91 ± 2.09

− 12.608

< 0.001

1 year after surgery

9.71 ± 1.82

14.29 ± 1.92

− 10.095

< 0.001

JOA

Before surgery

11.98 ± 2.19

12.32 ± 2.07

− 0.658

0.513

6 months after surgery

25.19 ± 2.76

20.12 ± 2.34

8.171

< 0.001

1 year after surgery

27.91 ± 2.37

23.28 ± 2.09

8.544

< 0.001