Factors associating with surgical site infection following operative management of malleolar fractures at an urban level 1 trauma center.

OBJECTIVES

To identify comorbidities and injury characteristics associated with surgical site infection (SSI) following internal fixation of malleolar fractures in an urban level 1 trauma setting.

DESIGN

Retrospective.

SETTING

Level 1 trauma center.

PATIENTS/PARTICIPANTS: Seven-hundred seventy-six consecutive patients with operatively managed malleolar fractures from 2006 to 2016.

INTERVENTION

Open reduction internal fixation.

MAIN OUTCOME MEASUREMENTS

Superficial SSI (erythema and drainage treated with oral antibiotics and wound care) or deep SSI (treated with surgical debridement and antibiotics).

RESULTS

Fifty-six (7.2%) patients developed SSI, with 17 (30%) of these being deep infections. An a-priori power analysis of n = 325 (α=0.05, β=0.2) was tabulated for differences in univariate analysis. Univariate analysis identified categorical associations ( < .05) between SSI and diabetes mellitus, drug abuse, open fracture, and renal disease but not tobacco abuse, body mass index, or neuropathy. Multivariate logistic regression identified categorical associations between diabetes (OR = 2.2, 95% CI: 1.1-4.3), drug abuse (OR = 3.9, 95% CI: 1.2-12.7), open fracture (OR = 4.1, 95% CI: 1.3-12.8), and renal disease (OR = 2.7, 95% CI: 1.4-5.0) and any (superficial or deep) SSI. A separate multivariate logistic regression analysis found categorical associations between deep SSI requiring reoperation and diabetes (OR = 4.4, 95% CI: 1.6-12.2) and open fracture (OR = 4.1, 95% CI: 1.3-12.8). Furthermore, American society of anesthesiologists classification (ASA) Class 4 patients were (OR = 9.2, 95% CI: 2.0-41.79) more likely to experience an SSI than ASA Class 1 patients.

CONCLUSIONS

Factors associated with SSI following malleolar fracture surgery in a single urban level 1 trauma center included diabetes, drug abuse, renal disease, and open fracture. The presence of diabetes or open type fractures were associated with deep SSI requiring reoperation.

LEVEL OF EVIDENCE

Level 3 prognostic: retrospective cohort study.