In Brazil, 118,960 hospitalizations occurred in 2024 due to musculoskeletal and skin infections, being the most common cause of infection-related hospitalization, with an annual growth rate of 10.9%. Fracture-related infections (FRI) stand out for their high hospital costs and morbidity. In order to propose medical management strategies for FRI, we aimed to characterize the clinical and microbiological aspects of FRIs through a prospective multicenter Brazilian study.

Clinical tissue samples from 11 hospitals were evaluated. Isolates were identified by MALDI-TOF MS, and antimicrobial susceptibility was determined by disk diffusion and broth microdilution. Statistical analyses were performed using chi-square and Fisher’s exact tests.

Among the 202 patients evaluated, 70.6% were male, with a mean age of 49 years (IQR 36–64). Fractures predominated in the lower limbs (74.6%), of which 25.4% were open (54.9% Gustilo III), and 18.0% were associated with polytrauma. The most frequent mechanisms were traffic accidents (31.4%) and falls from standing height (24.1%). The predominant diagnostic criteria for FRI were purulent secretion at the fracture site (31.9%), intraoperative microbiological identification (31.0%), and presence of fistula (20.6%). Microbiological findings revealed 312 isolates, with 40.6% being polymicrobial infections. Gram-negative bacilli (GNB) represented 38.5% of isolates, reaching 45.1% in polymicrobial infections (p = 0.01). The most frequent pathogens were S. aureus (36.5%; 35.1% MRSA), Enterobacteriaceae (24.7%), coagulase-negative staphylococci (12.2%), and Pseudomonas spp. (9.0%). S. aureuspredominated in monomicrobial infections (61.3%, p < 0.001). Enterobacteriaceae, coagulase-negative staphylococci, and Enterococcus were associated with polymicrobial infections (p < 0.05). S. aureus showed resistance to ERI (69.5%) and RIF (6.5%). Enterobacteriaceae showed resistance to TET (57.4%) and SMX-TMP (25.5%), with 10.4% producing ESBL. Recurrence occurred in 20.2% of cases, being more frequent in infections caused by S. aureus compared to other pathogens (31.4%, p = 0.05), and in cases treated surgically with implant retention (DAIR) (39.1%, p = 0.02).

In Brazil, FRIs are often polymicrobial and show a high prevalence of GNB. Recurrence rates are elevated, especially in the presence of S. aureus and when implant retention is chosen. These results reinforce the need for further national studies to guide FRI management.