Postoperative surgical site infection (SSI) is common in open long bone fractures, so early administration of prophylactic antibiotics is critical to prevent SSI. However, the necessity of initial broad-spectrum coverage for Gram-positive and -negative pathogens remains unclear. The purpose of this study was to clarify the effectiveness of prophylactic broad-spectrum antibiotics in a large, national-wide sample. We reviewed an open fracture database of prospectively collected data from 111 institutions managed by our society. A retrospective cohort study was designed to compare the rates of deep SSI between narrow- and broad-spectrum antibiotics, which were initiated within three hours after injury. A total of 1041 type III fractures were evaluated at three months after injury. Overall deep SSI rates did not differ significantly between the narrow-spectrum group (43/538, 8.0%) and broad-spectrum group (49/503, 9.8%) (p = 0.320). During propensity score-matched analysis, 425 pairs were analyzed. After matching, no significant difference in the SSI rate was seen between the narrow- and broad-spectrum groups, with 42 SSIs (9.9%) and 40 SSIs (9.4%), respectively (p = 0.816). The probability of deep SSI was not reduced by broad-spectrum antibiotics compared with narrow-spectrum antibiotics in type III open long bone fractures.
© 2023. The Author(s).