Table 1.
Baseline characteristics of all patients included in the study
| Variable | All patients (898) | No SSI (838) | SSI (60) | Lee et al. (1532) |
|---|---|---|---|---|
| Age | 52.2 (SD 16.1) | 51.9 (SD 16.0) | 56.9 (SD 16.5) | 49.5 |
| Gender | M 48.9%; F 51.1% | M 48.6%; F 51.4% | M 53.3%; F 46.7% | M 57%; F 43% |
| BMI | 26.1 (SD 4.7) | 26.0 (SD 4.5) | 27.9 (SD 5.9) | 27.7 |
| ASA | 1: 310 (34.5%) | 1: 295 (35.2%) | 1: 15 (25%) | |
| 2: 435 (48.4%) | 2: 416 (49.6%) | 2: 19 (31.7%) | ||
| 3: 150 (16.7%) | 3: 125 (14.9%) | 3: 25 (41.7%) | ||
| 4: 3 (0.3%) | 4: 2 (0.2%) | 4: 1 (1.7%) | ||
| Diagnosis* | Trauma 199 (22.1%) De novo degenerative scoliosis 54 (6.0%) Adult spinal deformity 59 (6.5%) Degenerative spinal cord compression disorder 379 (42.1%) Malignancy 42 (4.7%) Failed back surgery 96 (10.7%) One- or two-level degenerative disorder of the spine 61 (6.8%) Spondylodiscitis 8 (0.9%) |
Trauma 181 (21.6%) De novo degenerative scoliosis 51 (6.1%) Adult spinal deformity 58 (6.9%) Degenerative spinal cord compression disorder 358 (42.7%) Malignancy 35 (4.2%) Failed back surgery 90 (10.7%) One- or two-level degenerative disorder of the spine 58 (6.9%) Spondylodiscitis 7 (0.8%) |
Trauma 18 (30.0%) De novo degenerative scoliosis 3 (5.0%) Adult spinal deformity 1 (1.7%) Degenerative spinal cord compression disorder 21 (35.0%) Malignancy 7 (11.7%) Failed back surgery 6 (10.0%) One- or two-level degenerative disorder of the spine 3 (5.0%) Spondylodiscitis 1 (1.7%) |
Trauma 24.3% Degenerative 64.7% |
| SI score | 10.3 (SD 5.9) | 10.3 (SD 6.0) | 10.1 (SD 5.1) | Mean 8.5 |
| CHF | 49 (5.5%) | 44 (5.3%) | 5 (8.3%) | |
| Diabetes | 73 (8.2%) | 66 (7.9%) | 7 (11.6%) | |
| RA | 20 (2.2%) | 17 (2.0%) | 3 (5.0%) | |
| Previous operation | 253 (28.2%) | 234 (27.9%) | 19 (31.7%) | |
| Blood loss | 1124 mL (SD 1201 mL) | 1113 mL (SD 1211 mL) | 1276 mL (SD 1044 mL) | |
| Surgical time | 248 min (SD 100 min) | 247 min (SD 99 min) | 264 min (SD 123 min) | |
| Cage | 42.0% | 42.7% | 32.7% | |
| Number of levels fused | 3.2 (SD 2.9) | 3.2 (SD 2.9) | 3.3 (SD 2.5) | |
| Dural tear | 91 (10.1%) | 82 (9.8%) | 9 (15.0%) | |
| Combined anterior approach Posterior approach |
2.8% 97.2% |
2.8% 97.2% |
3.4% 96.6% |
22.8% 58.7% |
| Smoking | 285 (31.7%) | 265 (31.6%) | 20 (33.4%) | |
| Alcohol | 334 (37.2%) | 305 (36.4%) | 29 (40.0%) | |
| Transfusion | 281 (32.9%) | 257 (32.2%) | 24 (42.9%) | |
| Using NSAIDs post-OK | 433 (48.2%) | 398 (47.5%) | 35 (58.3%) | |
| Using NSAID pre-OK | 225 (25.1%) | 205 (24.5%) | 20 (33.3%) | |
| Amount of transfusion | 279 mL (SD 675 mL) | 273 mL (SD 682 mL) | 367 mL (572 mL) | |
| Timing AB prophylaxis before surgery | 37 min (SD 20 min) | 37 min (SD 19 min) | 42 min (SD 22 min) | |
| Mean FiO2 during surgery | 48.9 (SD 12) | 48.8 (SD 12) | 49.6 (SD 14.4) |
*Degenerative spinal cord compression disorder = spondylolisthesis, spinal stenosis, HNP; De novo degenerative scoliosis = degenerative scoliosis, junctional kyphosis; Adult spinal deformity = kyphosis, juvenile scoliosis, adolescent scoliosis, neuromuscular scoliosis, idiopathic scoliosis; One- or two-level degenerative disorder of the spine = degenerative discopathy, spondylosis, facetarthrosis, adjacent segment degeneration; Fracture = fracture with and without myelum compression; Failed back surgery = failed previous total disc replacement, pseudoarthrosis, failed previous laminectomy, failed previous posterior fusion, failed previous discectomy, failed previous anterior fusion, hardware failure