Table 2 Improvement of radiographic parameters from preoperative to follow-up

Preoperative

22.1 ± 15.0

34.1 ± 11.4

20.1 ± 5.3

48.5 ± 50.7

− 19.9 ± 16.7

− 27.9 ± 12.6

Postoperative

16.4 ± 10.7

8.5 ± 8.2

5.8 ± 5.7

23.8 ± 26.8

− 27.1 ± 15.4

− 23.7 ± 8.3

Change (post-pre)

8.1 ± 16.1

25.6 ± 9.9

14.3 ± 4.4

25.0 ± 44.0

7.1 ± 1.3

− 4.1 ± 10.5

Paired t test

t = 2.817, p = 0.008

t = 14.500, p < 0.001

t = 18.146, p < 0.001

t = 3.212, p = 0.003

t = 2.955, p = 0.006

t = 1.132, p = 0.266

Two-year FU

11.8 ± 8.7

8.7 ± 8.6

5.8 ± 5.7

29.2 ± 35.0

− 24.2 ± 18.4

− 22.6 ± 8.1

Change (follow-post)

2.2 ± 8.3

0.2 ± 0.7

0.1 ± 0.4

5.7 ± 21.5

− 2.7 ± 2.9

− 1.1 ± 1.3

Paired t test

t = 1.514, p = 0.140

t = − 1.561, p = 0.129

t = − 0.373, p = 0.712

t = − 1.495, p = 0.145

t = − 0.524, p = 0.604

t = 518, p = 0.606