Table 2.

Surgical technique and operation time in the two groups.

	Early (n = 25)	Late (n = 23)	P
Surgical technique
Foraminoplasty	2	3	.701∗
Pediculotomy	1	1	.952∗
Penetration of the posterior longitudinal ligament	16	22	.203∗
Procedure time
Preparation time (min)	23.88 ± 9.77	16.74 ± 5.76	.004†
Operation time (min)	66.00 ± 11.37	50.43 ± 7.52	<.001†
Total operation time (min)	86.48 ± 14.15	67.17 ± 7.66	<.001†

^∗Pearson's chi square test.

^†Independent t test.