What Is the Safe Window from Definitive Fixation to Flap Coverage in Type 3B Open Tibia Fractures? Supporting Plastics and Orthopaedics Alliance in Reducing Trauma Adverse Events (SPARTA)

Objectives:To delineate whether a "safe" window exists for timing from definitive fixation to definitive soft tissue coverage in the treatment of open tibial diaphyseal fractures requiring flap coverage.Design:International multicenter, retrospective comparative cohort study.Patients/Participants:Three hundred and seventy-three (n = 373) patients who sustained an open tibial shaft fracture requiring flap coverage.Methods:We evaluated the deep infection rates based on the timing between the definitive fixation and flap coverage. We determined several intervals of time from the day of definitive fixation (regardless of time from injury) and flap coverage. If performed on the same operative setting these were considered day 0. We evaluated coverage after 2 and 5 days from definitive fixation based on time versus infection rate curve inflection points. We adjusted for time to debridement and antibiotics within an hour.Main Outcome Measurement:Deep infection after definitive fixation and flap coverage.Results:The mean age of the cohort was 42.4 years (SD = 18.2) and 270 were male (72.4%). The deep infection rate after flap coverage was 20.6% (77/373). Definitive fixation to flap coverage time of up to 2 days was not associated with an increased risk of infection [relative risk (RR) = 1.12; 95% confidence interval, 0.92-1.37; P = 0.26]. There was an increased risk of deep infection for more than 2 days (RR = 1.59) and >5 days (RR = 1.64).Conclusion:This study observed a "safe" window of up to 2 days between definitive fixation and flap coverage in open tibial shaft fractures requiring coverage before a statistical increase in risk of deep infection rate occurred.