Patient demographic and treatment information (N = 246).
| Characteristic | Values |
| Age in years, mean (SD, range) | 42.5 (11.9, 21–81) |
| Male, n (%) | 124 (50) |
| BMI, mean (SD, range) | 26.2 (3.8, 19–37) |
| Comorbidities, n (%) | |
| Ex-smoker | 83 (34) |
| Current smoker | 38 (15) |
| Never smoker | 125 (51) |
| Prior microdiscectomy, n (%) | 17 (7) |
| Vascular adherence/dissection difficulty, n (%) | |
| Standard | 203 (82) |
| Difficult | 43 (18) |
| Blood loss (mL) | |
| Standard dissection | |
| Single-level mean (SD, range) | 126.6 (116.8, 20–490) |
| Two-level mean (SD, range) | 188.9 (202.6, 50–650) |
| Difficult dissection | |
| Single-level mean (SD, range) | 160.3 (280.7, 10–1420) |
| Two-level mean (SD, range) | 347.5 (355.3, 20–1550) |
| Type of operation, n (%) | |
| ALIF | 117 (48) |
| TDR | 69 (28) |
| Hybrid | 60 (24) |
| Level of operation, n (%) | |
| Single-level | |
| L4-5 | 50 (20) |
| L5-S1 | 121 (49) |
| Two-level | |
| L3-4 and L4-5 | 2 (1) |
| L4-5 and L5-S1 | 73 (30) |
| Modic changes, n (%) | |
| Type 1 | 11 (4) |
| Type 2 | 57 (23) |
ALIF, anterior lumbar interbody fusion; BMI, body mass index; TDR, total disc replacement.