Demographic data of enrolled individuals.
| Characteristic | Total(N = 90) | Group A(n = 48) | Group B(n = 42) |
| Sex n (%) | |||
| Men | 46 (51.1) | 26 (54.2) | 20 (47.6) |
| Women | 44 (48.9) | 22 (45.8) | 22 (52.4) |
| Age, y, mean ± SD | 73.0 ± 7.2 | 73.8 ± 6.1 | 72.0 ± 8.2 |
| Operated level, n (%) | |||
| L3-L4 | 20 (22.2) | 12 (25.0) | 8 (19.0) |
| L4-L5 | 49 (54.4) | 25 (52.1) | 24 (57.1) |
| L5-S1 | 21 (23.3) | 11 (22.9) | 10 (23.8) |