Comparison of microendoscopic discectomy and open discectomy for single-segment lumbar disc herniation

Table 3 Comparison of the visual analogue scale pain score in the two groups of patients before and after surgery (mean ± SD, min)

Group	Number of cases	Before surgery	1 d after operation	3 d after operation	1 mo after operation	6 mo after operation
Observation group	48	6.87 ± 1.56	2.75 ± 1.36	2.52 ± 1.42	2.01 ± 1.68	1.52 ± 1.24
Control group	48	7.04 ± 2.13	3.41 ± 1.76	3.13 ± 1.35	2.69 ± 1.49	2.13 ± 1.58
t		0.446	2.056	2.157	2.098	2.104
P value		0.657	0.043	0.034	0.039	0.038