Surgical site infection after femoral fracture surgery: 5-year trends in mechanisms of injury, pathogens, and antimicrobial resistance.

BACKGROUND

Femoral fractures are high-impact injuries commonly arising from traffic collisions, falls, and other trauma mechanisms. Surgical site infection (SSI) following fixation remains a major postoperative complication, amplified by soft-tissue disruption, environmental contamination, and prolonged hospitalization. Evidence on how mechanism of injury (MOI) moderates SSI risk, pathogen distribution, and antimicrobial resistance (AMR) patterns in trauma populations remains limited.

METHODS

We conducted a 5-year retrospective cohort study (2020-2024) at a tertiary trauma centre including all operatively managed femoral fractures. MOI categories comprised traffic accidents, falls, sports injuries, violence, work-related trauma, and firearm injuries. Demographic, clinical, surgical, and microbiological data were obtained from a prospectively maintained registry. SSI was defined according to the 2018 AO/EBJIS Fracture-Related Infection (FRI) consensus criteria. Group comparisons used χ2 or Fisher's exact tests, and multivariable logistic regression identified independent predictors. Infection-related reoperation and 1-year mortality were assessed with survival analysis.

FINDINGS: Of 2891 patients, 249 developed SSI (8.6%). Gram-negative organisms predominated, with A. baumannii accounting for most isolates across MOI groups, while S. aureus was more common in younger and sports-related injuries. Resistance testing showed persistently high multidrug resistance (MDR, 66.2%), with declining trends in extensively drug-resistant (XDR) phenotypes and carbapenem resistance over time. Independent predictors of SSI included ASA ≥ 3, diabetes mellitus, preoperative anaemia, and operative duration > 90 min. SSI markedly increased reoperation rates and more than doubled 1-year mortality.

CONCLUSION

MOI shapes both SSI risk and microbiological profiles following femoral fracture surgery. The dominance of Gram-negative organisms and high MDR burden highlight the need for MOI-specific prevention strategies and trauma-adapted antimicrobial stewardship.