Table 1 Summary of the patients’ demographic and clinical characteristics
| Â | n (%) |
|---|---|
Overall | 202 (100) |
Age (years) | |
 ≤ 59 | 24 (11.9) |
 60–69 | 49 (24.3) |
 70–79 | 76 (37.6) |
 ≥ 80 | 53 (26.2) |
Sex | |
 Male | 109 (54.0) |
 Female | 93 (46.0) |
Number of levels | |
 1 | 105 (52.0) |
 2 | 71 (35.1) |
 3 | 23 (11.4) |
 4 | 3 (1.5) |
Operated level | |
 L1/2 | 3 (1.5) |
 L2/3 | 39 (19.3) |
 L3/4 | 107 (53.0) |
 L4/5 | 160 (79.2) |
 L5/S | 20 (9.9) |