Short-term clinical outcomes of subway-related amputations

Abstract

Introduction: In city hospitals, subway-related traumatic amputations are a frequent pattern of injury, however there is a paucity of literature on this specific injury pattern. The purpose of this study was to describe the epidemiology of subway-related traumatic amputations, as well as compare them to non-subway traumatic amputations.

Patients and methods: Retrospective review was performed at a single Level-1 trauma center in a metropolitan area. All patients who sustained a traumatic lower-extremity amputation over a seven-year period were included. Demographics, injury, treatment-related information, and complications were collected. Subway and non-subway traumatic amputations were statistically compared. Cohorts were further subdivided into above-knee amputations (AKAs) and below-knee amputations (BKAs) for statistical comparison.

Results: Fifty-seven patients sustained 72 traumatic lower-extremity amputations, including 64 subway-related amputations. Fifteen patients with bilateral lower-extremity amputations all had subway-related injuries. Patients with subway-related injuries were more likely to have a history of alcohol use disorder (58.1 % vs. 0 %; P = 0.002), and experienced longer stays in the intensive care unit (ICU) (8.9 vs. 3.6 days; P = 0.006). Twenty-four amputations (33.3 %) were complicated by wound infection during the initial hospitalization, with wound cultures growing a variety of organisms, most frequently Enterococcus species and Enterobacter cloacae. When subway injuries were separated by AKAs and BKAs, patients with AKAs underwent more irrigation and debridement procedures on average (10.3 vs. 5.8; P = 0.006), had a higher rate of wound infections (58.8 % vs. 25.0 %; P = 0.018), and had longer hospital stays (50.4 vs. 32.2 days; P = 0.047).

Conclusion: Subway-related amputations are associated with longer ICU stays and a history of alcohol use disorder compared to non-subway traumatic amputations. Approximately 1/3 of these patients are expected to develop a wound infection, with Enterococcus and Enterobacter species being the most commonly identified organisms. Further research into high-energy, traumatic amputations, including subway injuries, may help improve prognostication of patient outcomes, identify potential in-hospital complications, and proactively direct differences in care compared to the standard for non-subway-related amputations.

Level of evidence: Prognostic Level III.

Keywords: Above knee amputation; Below knee amputation; Complication; Infection; Subway; Traumatic amputation; Wound.