Complications in early start vs late start cases.
| Parameter | Early Start (N = 771) | Late Start (N = 269) | P Value | ||
| n | % | n | % | ||
| Overall number of complications | 71 | 9.2 | 28 | 10.4 | 0.56 |
| Instrumentation-related complication | 13 | 1.7 | 8 | 3.0 | 0.20 |
| Postoperative cerebrospinal fluid leak | 11 | 1.4 | 4 | 1.5 | 0.94 |
| Wound infection | 7 | 0.9 | 6 | 2.2 | 0.09 |
| Seroma | 20 | 2.6 | 10 | 3.7 | 0.34 |
| Pulmonary embolism | 6 | 0.8 | 5 | 1.9 | 0.14 |
| Deep venous thrombosis | 5 | 0.6 | 3 | 1.1 | 0.45 |
| Postoperative pneumonia | 8 | 1.2 | 0 | 0 | 0.09 |
| Ileus | 10 | 1.3 | 4 | 1.5 | 0.82 |
| Postoperative urinary retention | 13 | 1.7 | 1 | 0.4 | 0.11 |
| Sacral fracture | 2 | 0.3 | 0 | 0 | 0.40 |
| Delirium | 5 | 0.6 | 2 | 0.7 | 0.87 |
| Epidural hematoma | 1 | 0.1 | 1 | 0.4 | 0.44 |
| Mortality | 2 | 0.3 | 2 | 0.7 | 0.27 |