Patient characteristics and operative details by group.
| Characteristics | VTE group (N = 9) | Non-VTE group (N = 324) | P |
| Gender, men:women | 6:3 | 227:97 | >0.99 |
| Age, y, mean ± SD | 79.6 ± 9.7 | 67.7 ± 13.5 | <0.01 |
| Disease | 0.54 | ||
| Cervical spondylotic myelopathy | 7 | 166 | |
| Herniated disc | 0 | 15 | |
| Tumor | 1 | 16 | |
| Atlantoaxial subluxation | 0 | 16 | |
| Pseudotumor | 0 | 10 | |
| Cervical spondylotic amyotrophy | 0 | 32 | |
| Ossification of the posterior longitudinal ligament | 0 | 49 | |
| Other | 1 | 20 | |
| Preoperative Japanese Orthopedic Association score | 7.0 ± 6.9 | 10.6 ± 3.5 | 0.46 |
| Surgical procedure | |||
| Fusion, n (%) | 4 (44.4%) | 131 (40.4%) | >0.99 |
| Fused vertebral levels, mean ± SD | 3.7 ± 4.5 | 1.8 ± 2.6 | 0.24 |
| Surgical time, min, mean ± SD | 228 ± 101 | 167 ± 85 | 0.10 |
| Blood loss volume, mL, mean ± SD | 259 ± 306 | 119 ± 147 | 0.20 |
| Preoperative D-dimer, μg/mL, mean ± SD | 7.9 ± 12.4 | 1.1 ± 1.2 | 0.14 |
| Postoperative D-dimer, μg/mL, mean ± SD | 10.6 ± 4.4 | 2.7 ± 2.1 | <0.01 |
| Diabetes mellitus, n (%) | 3 (33.3%) | 63 (19.4%) | 0.38 |
| Hypertension, n (%) | 3 (33.3%) | 106 (32.7%) | >0.99 |
| Rheumatoid arthritis, n (%) | 1 (11.1%) | 11 (3.3%) | 0.28 |
| Cardiovascular disease, n (%) | 4 (44.4%) | 36 (11.1%) | 0.011 |
| Atrial fibrillation, n (%) | 1 (11.1%) | 8 (2.4%) | 0.21 |
| Coronal artery disease, n (%) | 2 (22.2%) | 16 (4.8%) | 0.076 |
| Heart failure, n (%) | 0 (0%) | 5 (1.5%) | >0.99 |
| Cancer, n (%) | 1 (11.1%) | 27 (8.3%) | 0.55 |
| Dialysis, n (%) | 1 (11.1%) | 7 (2.1%) | 0.19 |
Abbreviation: VTE, venous thromboembolism.
Notes: Values represent the mean ± SD.