Fracture-related infection (FRI) is a challenging complication. This study aims to investigate (1) microbial patterns in fracture-related infection (FRI), (2) the comparison of isolated pathogens in FRI patients with early, delayed, and late onset of infection and (3) antibiotic susceptibility profiles to identify effective empiric antibiotic therapy for FRI.
Patients treated for FRI from 2013 to 2020 were grouped into early (< 2 weeks), delayed (2– 10 weeks) and late (> 10 weeks) onset of infection. Pathogens detected during treatment were evaluated for pathogens. Antibiotic susceptibility profiles were examined with respect to broadly used antibiotics and antibiotic combinations.
In total 117 patients (early n=19, delated n=60, late n=38) were included in the study. Infection was polymicrobial in 10 cases (8.6%) and culture-negative in 11 cases (9.4%). Staphylococcus aureus was the most frequently detected pathogen (40.5%), followed by Staphylococcus epidermidis (17.2%) and gram-negative bacteria (16.4%). Pathogen distribution did not differ statistically significant between the groups. Highest effectiveness could be achieved by the combination of meropenem + vancomycin (95.7%) and gentamycin + vancomycin (94.0%). More than 90% of all patients would have also been covered by co-amoxiclav + glycopeptide (93.2%), ciprofloxacin + glycopeptide and piperacillin/tazobactam + glycopeptide (92.3% each) as well as ceftriaxone + glycopeptide (91.5%). Comparing the predicted efficacy of empiric antimicrobial regimens between the subgroups only revealed a statistically significant difference regarding the combination ciprofloxacin with a glycopeptide (F= 3.304, p=.04), for which more patients with an early onset of infection would have been susceptible.
Microbiological pattern for the causative microorganism between early, delayed, and late FRI are comparable. Empiric therapy combinations such as meropenem + vancomycin, gentamycin +vancomycin or co-amoxiclav + glycopeptide are effective antibiotic strategies. To bypass unwanted side effects of systemic antibiotics and reduce the risk of antimicrobial resistance, the administration of local antibiotic carriers should be implemented in clinical practice.