Demographic and clinical patient data.
| Characteristic | N = 107 |
| Men/women, n | 44/63 |
| Age, y mean (range) | 84.1 (80–96) |
| Body mass index, mean (range) | 24.5 (17.0–33.6) |
| CCI score, mean (range) | 0.98 (0–5) |
| ASA score, mean (range) | 2.41 (1–4) |
| Operated level, n (%) | |
| 1-level | 60 (56.1%) |
| 2-level | 33 (30.8%) |
| 3-level | 7 (6.5%) |
| 4-level | 6 (5.6%) |
| 5-level | 1 (0.9%) |
| Severitya (Schizas grade), n ( %) | |
| C | 32 (29.9%) |
| D | 75 (70.1%) |
| Location, n (%) | |
| L1–L2 | 8 (4.6%) |
| L2–L3 | 25 (14.4%) |
| L3–L4 | 50 (28.7%) |
| L4–L5 | 80 (46.0%) |
| L5–S1 | 11 (6.3%) |
Abbreviations: ASA, American Society of Anesthesiologists; CCI, Charlson Comorbidity Index.
↵a Most severe level of operated segments.