Table 5 Comparison of encroachment ratio of the injured vertebral canal

 Preoperation

27.46 ± 8.73

28.94 ± 5.38

0.572

0.747

 3 days after operation

1.63 ± 0.59*

6.52 ± 4.56*

t = 4.921, P < 0.05

t = 4.840, P < 0.05

 Difference of the encroachment ratio of the injured vertebral canal between the preoperation and 3 days after the operation

25.46 ± 4.26

21.51 ± 1.36

3.295

0.033*