Abstract
Despite long-standing dogma, a clear relationship between the timing of surgical irrigation and the development of subsequent deep infection has not been established in the literature. Traditionally, irrigation of an open fracture has been recommended within six-hours of injury based on animal studies from the 1970s, however the clinical basis for this remains unclear. Using data from a multi-centre randomized controlled trial of 2,447 open fracture patients, the primary objective of this secondary analysis is to determine if a relationship exists between timing of wound irrigation (within six hours of injury versus beyond six hours) and subsequent reoperation rate for infection or healing complications within one year for patients with open extremity fractures requiring surgical treatment.
To adjust for the influence of patient and injury characteristics on the timing of irrigation, a propensity score was developed from the data set. Propensity-adjusted regression allowed for a matched cohort analysis within the study population to determine if early irrigation put patients independently at risk for reoperation, while controlling for confounding factors. Results were reported as odds ratios (ORs), 95% Confidence Intervals (CIs), and p-values. All analyses were conducted using STATA 14 (StataCorp LP, College Station, TX, USA).
Two thousand, two hundred eighty-six of 2,447 patients randomized to the trial from 41 orthopaedic trauma centers across five countries had complete data regarding time to irrigation. Prior to matching, the patients managed with early irrigation had a higher proportion requiring reoperation for infection or healing complications (17% versus 12.8%, p=0.02), however this does not account for selection bias of more severe injuries preferentially being treated earlier. After the propensity score-matching algorithm was applied, there were 373 matched pairs of patients available for comparison. In the matched cohort, reoperation rates did not differ between early and late groups (16.1% vs 16.6%, p=0.84). When accounting for propensity matching in a logistic regression analysis, early irrigation was not associated with reoperation (OR 0.93, 95% CI 0.62 to 1.40, p=0.73).
When accounting for other variables, late irrigation does not independently increase risk of reoperation.
