Primary Intra-Medullary Nailing of Open Tibia Fractures Caused by Low-Velocity Gunshots: Does Operative Debridement Increase Infection Rates?

Abstract

Background: Although gunshot-induced extremity fractures are typically not considered open fractures, there is controversy regarding wound management in the setting of operative fixation to limit infection complications. Previous studies have evaluated the need for a formal irrigation and debridement (I&D) prior to intra-medullary nailing (IMN) of gunshot-induced femur fractures but none have specifically evaluated tibias. By comparing primary IMN for tibial shaft fractures caused by low-velocity firearms additionally treated with a formal operative I&D (group 1) with those without an I&D (group 2), we sought to identify whether there are: differences in treatment group infection rates; particular fracture patterns more prone to infection; and patient characteristics more prone to infections.

Patients and methods: Retrospective cohort study at a single level I trauma center of gunshot-induced tibial shaft fractures managed primarily with IMN in 39 patients from October 1, 2008 to October 30, 2016. The following were studied: demographics, follow-up, fracture characteristics, injury management, and patient outcome. Fractures were categorized based on the Orthopaedic Trauma Association (OTA) classification system for diaphyseal tibia/fibula fractures. All patients had intravenous antibiotic agents at presentation and received three days of post-operative intravenous antibiotic agents per institutional protocol.

Results: In group 1, 6 of 23 patients (26.1%) developed superficial infections and 4 of 23 patients (17.4%) developed deep infections. In group 2, none of 16 patients (0%) developed superficial infections and 1 patient (6.25%) developed a deep infection, making the total cohort infection rate 28.2% (11/39). Superficial infections were associated with a formal I&D whereas deep infections were not. Tobacco smokers and type 42-A fractures had higher infection rates when treated with a formal I&D.

Conclusion: A formal debridement, followed by primary IMN in tibia fractures caused by low-velocity firearms is associated with an increased risk of superficial infection that is well managed with antibiotic agents, but the incorporation of a debridement does not affect rate of deep infection. A formal I&D during IMN fixation should be avoided in patients that are smokers and have type 42-A tibia fractures as these are factors associated with increased infection rates.

Keywords: debridement; gunshot wounds; infection; intra-medullary nailing; tibia fracture.