Qualitative data for patients who developed an infection (n = 28).
| Variable | n (%) |
| Gender | |
| Men | 8 (28.6) |
| Women | 20 (71.4) |
| Revision surgery | |
| Yes | 9 (32.1) |
| No | 19 (67.9) |
| Area | |
| Thoracic spine | 2 (7.1) |
| Lumbar spine | 20 (71.4) |
| Thoracolumbar spine | 6 (21.4) |
| No. of segments fused | |
| 2 | 10 (35.7) |
| 3 | 11 (39.3) |
| 4 | 5 (17.9) |
| 5 | 2 (7.1) |
| Antibiotic prophylaxis | |
| Cefazolin | 17 (60.7) |
| Vancomycin | 1 (3.6) |
| Cefazolin + aminoglycoside | 7 (25.0) |
| Cefazolin + gentamicin + rifampicin | 2 (7.1) |
| Unspecified | 1 (3.6) |
| Obesity (by body mass index [kg/m2]) | |
| <30 | 12 (46.2) |
| 30–35 | 12 (46.2) |
| >35 | 2 (7.7) |
| Smoking | |
| Yes | 1 (3.6) |
| No | 27 (96.4) |
| Malnutrition | |
| No | 28 (100) |
| American Society of Anesthesiologists class | |
| I | 10 (35.7) |
| III–IV | 18 (64.3) |
| History of infection | |
| Yes | 1 (3.6) |
| No | 27 (96.4) |
| Time at which infection occurred | |
| Early | 28 (100) |
| Infection level | |
| Deep | 28 (100) |
| Bacteria | |
| Gram-positive | 11 (39.3) |
| Gram-negative | 7 (25.0) |
| Mixed | 10 (35.7) |
| Sonication | |
| Performed | 2 (7.4) |
| Not performed | 25 (92.6) |
| Pathogen concordance | |
| Yes | 13 (46.4) |
| No | 15 (53.6) |
| Surgical procedure performed | |
| Debridement with instrument retention/replacement | 27 (96.4) |
| Complete removal | 1 (3.6) |
| No. of irrigations | |
| 1 | 3 (46.4) |
| 2 | 2 (42.9) |
| 3 | 1 (3.6) |
| 4 | 1 (3.6) |
| 6 | 1 (3.6) |
| Status at 2 year follow-up evaluation | |
| Infection cured with debridement | 23 (82.1) |
| Infection cured with hardware replacement | 4 (14.8) |
| Treatment failure | 1 (3.6) |
| Plastic surgery | |
| Yes | 4 (14.3) |
| No | 24 (85.7) |
| Vacuum-assisted closure therapy | |
| Yes | 6 (21.4) |
| No | 22 (78.6) |