Multisite Study of the Management of Musculoskeletal Infection After Trauma: The MMUSKIT Study.

Background: The optimal duration and choice of antibiotic for fracture-related infection (FRI) is not well defined. This study aimed to determine whether antibiotic duration (≤6 vs >6 weeks) is associated with infection- and surgery-free survival. The secondary aim was to ascertain risk factors associated with surgery- and infection-free survival.

Methods: We performed a multicenter retrospective study of patients diagnosed with FRI between 2013 and 2022. The association between antibiotic duration and surgery- and infection-free survival was assessed by Cox proportional hazard models. Models were weighted by the inverse of the propensity score, calculated with a priori variables of hardware removal; infection due to , , or species; and flap coverage. Multivariable Cox proportional hazard models were run with additional covariates including initial pathogen, need for flap, and hardware removal.

Results: Of 96 patients, 54 (56.3%) received ≤6 weeks of antibiotics and 42 (43.7%) received >6 weeks. There was no association between longer antibiotic duration and surgery-free survival (hazard ratio [HR], 0.95; 95% CI, .65-1.38; = .78) or infection-free survival (HR, 0.77; 95% CI, .30-1.96; = .58). Negative culture was associated with increased hazard of reoperation or death (HR, 3.52; 95% CI, 1.99-6.20; < .001) and reinfection or death (HR, 3.71; 95% CI, 1.24-11.09; < .001). Need for flap coverage had an increased hazard of reoperation or death (HR, 3.24; 95% CI, 1.61-6.54; = .001).

Conclusions: The ideal duration of antibiotics to treat FRI is unclear. In this multicenter study, there was no association between antibiotic treatment duration and surgery- or infection-free survival.