Risk factors and clinical significance of posterior slip of the proximal vertebral body after lower lumbar fusion

Table 4 Quality of life of the patients in the two groups, mean ± SD

	Nonretrograde group	Retrograde group	t value	P value
ODI score
Preoperative	41.4 ± 11.9	40.8 ± 10.3	0.201	0.841
Postoperative	21.1 ± 7.2	26.1 ± 7.4	2.677	< 0.001
Final follow-up	18.0 ± 6.3	24.2 ± 4.6	4.009	< 0.001
VAS score
Preoperative	7.0 ± 2.2	7.4 ± 2.5	0.685	0.495
Postoperative	2.2 ± 1.2	3.1 ± 1.6	2.703	0.008
Final follow-up	1.8 ± 1.1	2.9 ± 1.4	3.654	< 0.001

ODI: Oswestry Disability Index; VAS: Visual Analogue Scale.