2.

A、B两组间椎管前后径的比较(x±s)

Comparison of anteroposterior diameter between the two groups (x±s) /mm

Segment	Pre-operation			Post-operation			Final follow-up
	Group A	Group B	P	Group A	Group B	P	Group A	Group B	P
C3	15.2±1.1	15.5±1.4	0.49	23.3±2.4	23.2±2.5	0.89	22.3±1.4	22.1±2.1	0.70
C4	14.7±1.3	14.8±1.4	0.75	22.6±2.3	22.8±2.1	0.61	22.1±1.3	21.9±2.0	0.77
C5	15.1±1.2	15.7±1.5	0.12	24.1±2.1	23.6±2.2	0.42	23.6±1.4	22.5±2.0	0.06
C6	16.2±1.2	16.3±1.5	0.74	24.6±2.2	25.0±2.0	0.54	23.7±1.6	24.1±1.7	0.46
C7	16.3±1.2	17.0±1.7	0.06	25.7±2.6	25.1±2.3	0.39	25.0±2.1	24.5±1.9	0.55