Table 2.

The sagittal cervical canal diameter at each pedicle level

Group	C3†	C4†	C5†	C6††	C7
A	14.39 ± 1.87	14.27 ± 1.85	14.29 ± 1.77	14.35 ± 1.81	14.42 ± 1.70
B	13.39 ± 3.05*	13.39 ± 2.88*	13.82 ± 2.65	13.94 ± 2.90	13.96 ± 2.29
C	13.75 ± 2.36*	13.37 ± 2.08**	13.36 ± 1.98**	13.43 ± 1.81**	13.83 ± 1.72*
D	13.13 ± 2.27***	12.79 ± 2.09***	12.77 ± 1.95***	12.57 ± 2.00***	13.60 ± 1.74**

Compared with group A: *p < 0.05, **p < 0.01, ***p < 0.001

Compared between groups C and D: †p < 0.05, ††p < 0.01, †††p < 0.001