Table 2.
Univariate analysis of risk factors associated with SSI
| Variables | SSI (n = 66, 9.7%) | No SSI (n = 615, 90.3%) | P value |
|---|---|---|---|
| Open fracture | 16 (24.2) | 19 (3.1) | 0.00003**** |
| Sanders grade | 0.08191 | ||
| I | 4 (6.1) | 18 (2.9) | |
| II | 36 (54.5) | 319 (51.9) | |
| III | 19 (28.8) | 191 (31.1) | |
| IV | 7 (10.6) | 87 (14.1) | |
| Operation season (summer) | 28 (42.4) | 233 (37.9) | 0.78615 |
| Intraoperative blood loss (≥ 400 ml) | 2 (3.0) | 15 (2.4) | 0.77030 |
| Extended lateral approach | 15 (22.7) | 181 (29.4) | 0.24816 |
| Fixation type (plate and screws) | 37 (56.1) | 294 (47.8) | 0.20429 |
| Length of operative incision (cm) | 0.51307 | ||
| < 7 | 23 (34.8) | 200 (32.5) | |
| 7–11 | 24 (36.4) | 210 (34.1) | |
| > 11 | 19 (28.8) | 205 (33.3) | |
| Operative time | 0.05660 | ||
| < 120 min | 29 (43.9) | 380 (61.8) | |
| 120–180 min | 36 (54.5) | 205 (33.3) | |
| > 180 min | 1 (1.5) | 30 (4.9) | |
| Intraoperative temperature(< 36.0 °C) | 21 (31.8) | 103 (16.7) | 0.01807* |
| Gender | 0.26118 | ||
| Male | 63 (95.5) | 562 (91.4) | |
| Female | 3 (4.5) | 53 (8.6) | |
| Preoperative stay | 0.36943 | ||
| ≤ 14 days | 63 (95.5) | 599 (97.4) | |
| > 14 days | 3 (4.5) | 16 (2.6) | |
| Surgeon level (resident and visiting staff) | 16 (24.2) | 111 (18.0) | 0.22901 |
| Injury mechanism (high energy) | 47 (71.2) | 310 (50.4) | 0.00204** |
| Obesity (BMI ≥ 28.0) | 10 (15.2) | 71 (11.5) | 0.39142 |
| Diabetes mellitus | 0 (0) | 20 (3.3) | 0.99836 |
| Hypertension | 7 (10.6) | 53 (8.6) | 0.58909 |
| Coronary heart disease | 3 (45.5) | 8 (1.3) | 0.06311 |
| History of anemia | 0 (0) | 3 (0.5) | 0.99910 |
| Tobacco consumption | 13 (19.7) | 149 (24.2) | 0.41327 |
| History of alcohol intake | 12 (18.2) | 117 (19.0) | 0.86844 |
| Allergic history | 4 (6.1) | 25 (4.1) | 0.44905 |
| Previous operation | 9 (13.6) | 49 (8.0) | 0.12219 |
| ASA score (≥ 3) | 5 (7.6) | 14 (2.3) | 0.01903* |
| General anesthesia | 11 (16.7) | 64 (10.4) | 0.67229 |
| Preoperative antibiotics use | 17 (25.8) | 69 (11.2) | 0.00107** |
| Intraoperative antibiotics use | 61 (92.4) | 555 (90.2) | 0.56822 |
| Drainage use | 39 (59.1) | 332 (54.0) | 0.42941 |
| TP (< 65 g/L) | 28 (42.4) | 221 (36.0) | 0.29930 |
| ALB (< 40 g/L) | 19 (28.8) | 137 (22.3) | 0.23307 |
| GLOB (< 20 g/L) | 15 (22.7) | 91 (14.8) | 0.16344 |
| A/G | 0.46406 | ||
| References (1.2–2.4) | 59 (89.4) | 564 (91.7) | |
| < 1.2 | 1 (1.5) | 11 (1.8) | |
| > 2.4 | 6 (9.1) | 40 (6.5) | |
| WBC (109/L) | 0.46511 | ||
| References (4–10) | 47 (71.2) | 465 (75.6) | |
| < 4 | 1 (1.5) | 5 (0.8) | |
| > 10 | 18 (27.3) | 145 (23.6) | |
| NEUT (109/L) | 0.39405 | ||
| References (1.8–6.3) | 39 (59.1) | 394 (64.1) | |
| > 6.3 | 27 (40.9) | 217 (35.3) | |
| LYM (109/L) | 0.99515 | ||
| References (1.1–3.2) | 56 (84.9) | 533 (86.7) | |
| < 1.1 | 10 (15.2) | 71 (11.5) | |
| > 3.2 | 0 (0) | 11 (1.8) | |
| MON (109/L) | 0.79901 | ||
| References (0.1–0.6) | 31 (47.0) | 298 (48.5) | |
| > 0.6 | 35 (53.0) | 315 (51.2) | |
| BAS (109/L) | 0.08710 | ||
| References (0–0.06) | 60 (90.9) | 577 (93.8) | |
| > 0.06 | 6 (9.1) | 18 (2.9) |
TP total protein, A albumin, G globulin, A/G albumin/globulin, WBC white blood cell, NEUT neutrophile, LYM lymphocyte, MON monocyte, BAS basophilic
Significant Variables (*P < 0.05; **P < 0.01; ****P < 0.0001)