Risk Factors for Surgical Site Infection after Operative Management of Pilon Fractures

Abstract

Category: Trauma; Ankle Introduction/Purpose: Pilon fractures are complex injuries that most commonly result from high-energy trauma. The extensive soft tissue damage and high rates of associated infection seen in these injuries remains a challenging concern for surgeons. The purpose of this study is to identify risk factors associated with surgical site infection (SSI) following operative management of pilon fractures. Methods: A retrospective review of all operatively managed pilon fractures at a single level 1 trauma center from 2014 to 2019 was performed. Minimum six-month follow-up and skeletal maturity was required for inclusion. Patients with amputation prior to definitive fixation were excluded. SSI consisted of superficial (defined as infection resolving with oral antibiotics) and/or deep infections (defined as return to the operating room for debridement with positive cultures). Patients were grouped based on presence or absence of SSI. Demographics, injury and operative characteristics, and surgical outcomes were compared between the two groups. Results: A total of 279 patients met inclusion criteria for the study, with 40 patients developing SSI (14.3%). Average follow-up was 3.2 years. Patients that developed SSI had a significantly higher proportion of open fractures (47.5% vs 23.4%, p=0.003); however, there were no significant differences in Gustilo-Anderson classification or open wound location compared to controls. The SSI group required significantly higher rates of skin grafts (25.0% vs 4.2%, p<0.001) and muscle flap coverage (20.0% vs 1.7%, p<0.001). Average operative time was significantly longer in the SSI group (283.1 vs. 222.3 minutes, p=0.002). Patients with SSI displayed significantly higher rates of nonunion at six-month follow-up compared to those without SSI (55.0% vs 10.9%, p<0.001). There were no significant differences in mechanism of injury, AO/OTA fracture classification, associated ipsilateral lower extremity injuries, bone grafting, surgical approach, or presence of medial column fixation between the two groups. Conclusion: The present study showed that SSI after pilon fractures can lead to significant morbidity, with 55% of patients having nonunion at six months. Risk factors for SSI in these patients included open fracture, need for soft tissue coverage, and longer operative times. Future multicenter studies are needed to further investigate risk factors for SSI after operative management of pilon fractures.