Table 6 Comparison of radiological parameters before and after surgery

DH(\(\bar{x} \pm s\), mm)

9.39 ± 2.04

8.81 ± 2.12

t=3.207

0.002

the adjacent upper segment DH(\(\bar{x} \pm s\), mm)

9.60 ± 1.81

9.65 ± 1.76

t=-0.371

0.712

FH(\(\bar{x} \pm s\), mm)

17.57 ± 2.19

17.07 ± 2.52

t=2.003

0.049

the adjacent upper segment FH(\(\bar{x} \pm s\), mm)

18.84 ± 2.98

18.58 ± 2.50

t=1.046

0.299

LLA(\(\bar{x} \pm s\), °)

40.19 ± 14.68

39.89 ± 13.59

t=0.322

0.749

Pfirrmann grading(example, 1/2/3/4/5)

26/24/6/5/5

15/23/13/9/6

χ²=6.785

0.148

the adjacent upper segment Pfirrmann grading(example, 1/2/3/4/5)

28/23/7/5/3

16/21/11/10/8

χ²=8.192

0.085

intervertebral disc angle(\(\bar{x} \pm s\), °)

9.71 ± 2.03

9.85 ± 1.89

t=-0.571

0.570

the adjacent upper segment intervertebral disc angle(\(\bar{x} \pm s\), °)

10.08 ± 2.27

10.23 ± 2.05

t=-0.559

0.578

anterior-posterior translation distance(\(\bar{x} \pm s\), mm)

1.78 ± 0.25

1.76 ± 0.29

t=0.697

0.488

the adjacent upper segment anterior-posterior translation distance(\(\bar{x} \pm s\), mm)

1.79 ± 0.25

1.79 ± 0.22

t=-0.155

0.877