Microbiological Profile of Periprosthetic Infections Following Femoral Fracture: A Retrospective Analysis.

Background: Implant-related infection following femoral fracture surgery is a severe complication in elderly patients and is associated with high morbidity and mortality. Most available evidence on periprosthetic joint infection (PJI) derives from elective arthroplasty populations, which differ substantially from patients undergoing surgery for femoral fractures. This study aimed to investigate the microbiological profile and clinical characteristics of implant-related infections after proximal femoral fracture surgery. Materials and Methods: A retrospective observational study was conducted on 20 patients aged ≥70 years who developed implant-related infection after surgical treatment of proximal femoral fractures between 2020 and 2025 at a referral trauma center. Surgical procedures included intramedullary nailing, hemiarthroplasty, and total hip arthroplasty. Only patients with Charlson Comorbidity Index ≥ 4 and infection occurring within one year of the index surgery were included. Clinical, surgical, microbiological, and antibiotic therapy data were retrospectively reviewed. Results: The cohort had a mean age of 82.4 years and a high comorbidity burden (mean Charlson index 4.8). The most frequently isolated pathogen was Staphylococcus aureus (25.9%), with 85% methicillin-resistant strains. Other pathogens included Enterococcus faecalis, Klebsiella pneumoniae, and Escherichia coli. Polymicrobial infections were observed in 25% of patients. One-year mortality was 25%. Conclusions: Implant-related infections after femoral fracture surgery represent a distinct clinical entity compared with elective PJI, characterized by frail patients and a higher prevalence of multidrug-resistant organisms. These findings highlight the need for tailored preventive and therapeutic strategies in this high-risk population.