Table 1.

Preoperative and postoperative radiographic parameters of the enrolled group according to the results of computed tomography examination

	Preoperative value	Postoperative value	Statistical	Р value
Vertebral canal square in axial plane mm2	m = 102.4468 ± 8.6091	m = 150.3774 ± 8.9059	t-test for matched samples	< 0.0001
	SD = 67.7880	SD = 70.1252
	95%CI: 85.2319, 119.6617	95%CI: 132.5689, 168.1859
Left lateral recess depth in axial plane mm	M = 3.90	M = 4.95	Wilcoxon test	< 0.0001
	25%-75%: (2.8, 4.8)	25%-75%: (3.7, 6.2)
Left lateral recess depth in axial plane mm	M = 3.45	M = 4.95	Wilcoxon test	< 0.0001
	25%-75%: (2.7, 5.0)	25%-75%: (3.8, 6.2)
Disc height along the midline of anterior boarders of vertebral bodies	m = 6.6677 ± 0.3016	m = 12.0161 ± 0.2734	t-test for matched samples	< 0.0001
	SD = 2.3751	SD = 2.1531
	95%CI: 6.0646, 7.2709	95%CI: 11.8693, 12.963
Disc height along the midline of posterior boarders of vertebral bodies	m = 4.4500 ± 0.2496	m = 7.1871 ± 0.2749	t-test for matched samples	< 0.0001
	SD = 1.9656	SD = 2.1649
	95%CI: 3.9508, 4.949	95%CI: 6.6373, 7.736

M: Median; m: Mean.