Summary of baseline characteristics.
| Characteristic | N = 50 |
| Sex, n | |
| Men | 24 |
| Women | 26 |
| Age, y, mean (range) | 59.7 (28–80) |
| Body mass index, mean (range) | 28.7 (18.2–42.6) |
| Diagnosis, n | |
| Deformity | 14 |
| Degenerative disc disease | 36 |
| Fusion extent, n | |
| 1 Interbody level (L5–S1) | 14 |
| 2 Interbody levels (L4–S1) | 21 |
| 3–6 Interbody levels (L3–S1 to T12–S1) | 15 |