Open Ankle Fractures: What Predicts Infection? A Multi-center Study

SLR - January 2022 - Kyle D. Miller

References: Cooke ME, Tornetta P, Firoozabadi R, Vallier H, Weinberg D, Alton T, Dillman M, Westberg J, Schmidt A, Bosse M, Leas, D, Archdeacon M, Kakazu R, Nzegwu I, OToole RV, Costales TG, Coale M, Mullis B, Usmani RH, Egol K, Kottmeier S, Sanders D, Jones C, Miller AN, Horwitz DS, Kempegowda H, Morshed S, Belaye T, Teague D. Open Ankle Fractures: What Predicts Infection? A Multi-center Study. J Orthop Trauma. 2021 Oct 14. Online ahead of print

Level of Evidence: Level III

Scientific Literature Review

Reviewed By: Kyle D. Miller, DPM
Residency Program: INOVA Fairfax - Falls Church, Virgina

Podiatric Relevance: Ankle fractures are one of the most common fractures seen in the foot and ankle community. They present as open injuries 2-5 percent of the time. There is little data specifically investigating these ankle open fracture types when considering infection risk and outcomes. Most of our treatment algorithms are extrapolated from other open type injuries specifically utilizing Gustilo-Anderson as a guide. If we can better understand the fracture and/or patient specific factors that predispose patients to higher risk of infection after open ankle fractures, we should be able to better manage them in the perioperative period or at least provide more appropriate counseling to patients prognostically as to their potential outcomes.

Methods: Sixteen trauma centers with 16 separate principal investigators were involved where records of 1003 patients with open ankle fractures were retrospectively reviewed. Exclusion criteria included skeletal immaturity, pathologic fracture, pilon fracture, non-ambulatory prior to injury or had less than 12 weeks of clinical follow-up after initial presentation. Data analyzed included age, sex, body mass index (BMI), smoking history, medical co-morbidities, neuropathy, wound location and wound contamination. Classification systems included Orthopaedic Trauma Association/AO Foundation (OTA/AO), Lauge-Hanson, Injury Severity Score (ISS) and Gustilo-Anderson classification. Authors evaluated time from injury to: administration of antibiotics, wound debridement including method of closure, and closure. They also evaluated the need for graft versus flap closure

Results: Of the 1,003 patients, 712 met inclusion criteria with minimum 12 weeks of follow up. Regarding wound location 78 percent were directly medial and 66 percent of fractures were dislocated on presentation. Level of contamination between locations was reportedly similar for all groups. Interestingly lateral wounds were more likely to become infected (26 percent vs 14 percent, p= 0.04). Overall fracture related infection was 15% with men, diabetics, smokers, patients on immunosuppressants and neuropathic patients were identified as those with increased risk (p= 0.033). There was no difference in infection rate between patients with or without workers compensation. Time to antibiotics was not associated with increased risk of infection even if delayed, however nearly all patients received early antibiotics. Regarding debridement and closure there was no association even with debridement up to 15.6 hours after injury. Time to definitive closure (5.4 vs. 1.5 days) is a significant risk factor in those who developed infection.

Conclusions: The overall 15 percent infection rate in open ankle fractures appears to be similar and acceptable between institutions. Risk factors for infection in these open fractures include male sex, diabetes, smoking, immunosuppressive medications, and lateral wound location which were noted to be statistically significant. Timing to initial debridement (i.e. the golden window) does not appear to be as important as previously thought. However, we do now know that longer time to definitive closure is a statistically significant risk factor for developing infection if greater than 1.5 days, therefore, closure should be performed as early as possible as long as reasonably safe for the patient. These are important factors for the foot and ankle surgeon to understand in managing as well as in preparing patients for the post-injury and perioperative course