Table 1: Baseline data.

Parameter Prolapse (n = 90; 82.6%) Osteochondrosis (n = 19; 17.4%) p-Value
Age (mean years, SD) 49.0 ± 0 11.7 60.2 ± 8.7 < 0.01a
Sex Female gender (n,%) 53 (58.9) 8 (41.2) 0.21b
Male gender (n,%) 37 (41.1) 11 (57.9)
body weight (kg, SD) 84.2 ± 14.4 78.4 ± 14.6 0.11a
height (cm, SD) 174.3 ± 8.1 168.3 ± 6.5 < 0.01a
Body mass index (kg/m², SD) 27.7 ± 4.1 27.7 ± 4.9 0.99a
Smoking habits      
never smoking (n,%) 45 (41.3) 9 (8.3) 0.84c
ex-smoker (n,%) 18 (16.5) 5 (4.6)
current smoker (n,%) 27 (24.8) 5 (4.6)
Spinal leveld (n,%) L1/L2  0  1 (5.3) < 0.01c
L2/L3  3 (3.3)  0
L4/L4  4 (4.4)  5 (26.3)
L4/L5  45 (50.0)  12 (63.2)
L5/S1  38 (42.4)  1 (5.3)

Legend: Demographic and clinical characteristics of 109 patients with lumbar intervertebral disc surgery.
a Student’s t-test for independent samples.
b Fisher’s exact test.
c Likelihood ratio-test.
d given are the column percentages.