Table 2.

Univariate analysis of 150 patients with DIAM™ implantation for primary lumbar spinal stenosis or disc herniation

Variables	Total number	Number of reoperation	4-year reoperation (%)	Chi-square	p value
Age				0.70	0.40
<50	90	3	3.3
≥50	60	4	6.7
Gender				1.93	0.16
Male	84	2	2.4
Female	66	5	7.6
Diagnosis				0.18	0.67
Stenosis	96	5	5.2
Disc	54	2	3.7
Location				9.43	0.002*
L4–5	115	3	2.6
L5–6	31	3	9.7
Level				6.70	0.01*
One	146	6	4.1
Two	4	1	25.0

* Statistically significant by the log-rank test