The impact of smoking on hospital course and postoperative outcomes in patients with fracture-related infections

Abstract

OBJECTIVE: To assess the relationship between patient smoking status and fracture-related infection (FRI) characteristics including patient symptoms at FRI presentation, bacterial species of FRI, and rates of fracture union. METHODS: Design: Retrospective cohort study. Setting: Urban level 1 trauma center. Patient Selection Criteria: All patients undergoing reoperation for FRI from January 2013 to April 2021 were identified via manual review of an institutional database. Outcome Measures and Comparisons: Data including patient demographics, fracture characteristics, infection presentation, and hospital course were collected via review of the electronic medical record. Patients were grouped based on current smoker versus non-smoker status. Hospital course and postoperative outcomes of these groups were then compared. Risk factors for methicillin-resistant Staphylococcus aureus (MRSA) infection, Staphylococcus epidermidis infection, and sinus tract development were evaluated using multivariable logistic regression. RESULTS: A total of 301 patients, comprised of 155 (51%) smokers and 146 (49%) non-smokers, undergoing FRI reoperation were included. Compared to non-smokers, smokers were more likely male (69% vs. 56%, p = 0.024), were younger at the time of FRI reoperation (41.7 years vs. 49.5 years, p < 0.001), and had lower mean BMI (27.2 vs. 32.0, p < 0.001). Smokers also had lower prevalence of diabetes mellitus (13% vs. 25%, p = 0.008) and had higher Charlson Comorbidity Index 10-year estimated survival (93% vs. 81%, p < 0.001). Smokers had a lower proportion of S. epidermidis infections (11% vs. 20%, p = 0.037), higher risk of nonunion following index fracture surgery (74% vs. 61%, p = 0.018), and higher risk of sinus tracts at FRI presentation (38% vs. 23%, p = 0.004). On multivariable analysis, smoking was not found to be associated with increased odds of MRSA infection. CONCLUSION: Among patients who develop a fracture related infection, smokers appeared to have better baseline health in terms of age, body mass index, diabetes mellitus, and Charlson Comorbidity Index 10-year estimated survival compared to non-smokers. Smoking status was not significantly associated with odds of MRSA infection. However, smoking status was associated with increased risk of sinus tract development and nonunion as well as lower rates of S. epidermidis infection at the time of FRI reoperation.