The impact of duration of infection on outcome of debridement, antimicrobial treatment and implant retention in fracture-related infections of the lower leg: A multicentre retrospective cohort study

Aim This study aimed to assess the association between the interval from initial fracture fixation to debridement, antibiotics and implant retention (DAIR) for fracture-related infection (FRI) (referred to as the FF-FRI interval) and treatment outcome in patients with FRI of the lower leg. Methods This multinational retrospective cohort study included patients over 18-years of age who were diagnosed with an FRI of the lower leg, who underwent FRI surgery within 12 weeks after initial fracture fixation, between January 1st 2015 and July 1st 2020. All patients had a minimum follow-up of 12 months after cessation of therapy. Treatment success was defined as a combination of implant retention, eradication of infection, fracture healing and preservation of the affected limb. Both univariate and multivariable models were employed to ascertain factors associated with treatment outcome following DAIR. Results A total of 100 patients were treated with DAIR. The median FF-FRI interval was 17 days (range: 1–63). A total of 57/100 patients (57%) had a successful treatment outcome after a median follow-up of 33.6 (P₂₅-P₇₅: 18.4–50.7) months. In 11 out of 22 patients (50%) identical pathogens were cultured at time of recurrent infection. The multivariable analysis demonstrated no statistically significant effect of the FF-FRI interval (HR: 1.01; 95%CI: [1.00–1.03]; p: 0.059). Conclusion This study found no association between time to DAIR surgery and treatment outcome of DAIR procedures up to nine weeks, in patients with an FRI of the lower leg, however the success rate, when applying strict definition of treatment success, of 57% rate is limited. In clinical practice, this indicates that attempts to retain an implant can be considered at least up to nine weeks after initial fracture fixation, provided that other surgical decision-making factors (e.g. implant stability, adequate debridement, and soft tissue coverage) permit it.