Impact of duration of perioperative antibiotic prophylaxis on development of fracture-related infection in open fractures.

INTRODUCTION: Infection is a common complication of open fractures potentially leading to nonunion, functional loss, and even amputation. Perioperative antibiotic prophylaxis (PAP) is standard practice for infection prevention in the management of open fractures. However, optimal duration of PAP remains controversial. The objectives were to assess whether PAP duration is independently associated with infection in open fractures and if administration of PAP beyond the commonly-recommended limit of 72 h has any effect on the infection rate. MATERIALS AND METHODS: Over a 14-year period from 2003 to 2017, 530 skeletally-mature patients with operatively-treated, non-pathologic, long-bone open fractures were treated at one institution. Twenty-eight patients were excluded because of death or loss to follow-up and the remaining 502 patients (with 559 open fractures) who completed a 24-month follow-up were included in this retrospective study. The outcome was fracture-related infection (FRI), defined by the criteria of a recent consensus definition. A logistic generalized estimating equations regression model was conducted, including PAP duration and variables selected by a least absolute shrinkage and selection operator (LASSO) method, to assess the association between PAP duration and FRI. Propensity score analysis using a 72-h cut-off was performed to further cope with confounding. RESULTS: PAP duration, adjusted for the LASSO selected predictors, was independently associated with FRI (OR: 1.11 [95%CI, 1.04-1.19] for every one-day increase in PAP duration, p = 0.003). PAP duration longer than 72 h did not significantly increase the odds for FRI compared to shorter durations (p = 0.06, analysis adjusted for propensity score). CONCLUSIONS: This study found no evidence that administration of prophylactic antibiotics beyond 72 h in patients with long-bone open fractures is warranted. Analyses adjusted for known confounders even revealed a higher risk for FRI for longer PAP. However, this effect cannot necessarily be considered as causal and further research is needed.