Single Antibiotic Use with Ceftriaxone for Prophylaxis of All Open Fractures

OBJECTIVES: To compare outcomes for open fractures treated with a prophylactic antibiotic protocol using ceftriaxone for all open fractures, referred to as group "CTX", versus a previous protocol utilizing cefazolin for Gustilo I/II fractures and cefazolin plus gentamicin or ceftriaxone monotherapy for Gustilo type III fractures only, referred to as group "Classic". METHODS: Design: Retrospective cohort study. SETTING: Single level I trauma center. PATIENT SELECTION CRITERIA: This study included adult patients undergoing surgery for an open fracture from December 2016 to December 2022 with a minimum follow-up of 3 months.Outcome Measures and Comparisons: The primary outcome of deep infection and secondary outcomes of superficial infection rates, nonunion rate, and time to antibiotic administration were compared between overall groups and subgroups based on Gustilo type. RESULTS: A total of 521 patients were included. Baseline characteristics were similar between groups, with no differences in age (CTX 41.1±19.7 vs Classic 39.5±19.3), sex (68.5% vs 72.0% male), or comorbidities (p>0.05). There were no differences in deep infection (7.8% vs 12.7%, p=0.095), superficial infection (7.0% vs 4.7%, p=0.427), or nonunion (10.3% vs 7.9%, p=0.500) between CTX and Classic groups for all Gustilo types. Similarly for only type I/II fractures, rates of deep infection (3.5% vs 8.9%, p=0.145), superficial infection (2.9% vs 3.6%, p=0.683), and nonunion (3.6% vs 0.0%, p=0.340) did not differ. Non-inferiority of CTX for deep infection was demonstrated for all Gustilo types (intergroup difference -0.048, p=0.027) and type I/II fractures (-0.054, p=0.035). The CTX protocol was associated with shorter time to antibiotic administration (63.9±116.9 vs 114.1±199.0 minutes, p=0.002). CONCLUSIONS: The use of ceftriaxone for prophylaxis of all open fractures, regardless of Gustilo type, was associated with non-inferior outcomes in terms of deep infection as well as shorter time to antibiotic administration, compared to a regimen where type I/II fractures received cefazolin. No significant differences in rates of superficial infection or nonunion were noted following transition to CTX protocol. The study was notably under-powered to detect a difference in the primary outcome of deep infection. Prophylaxis of all open fractures with ceftriaxone may be a safe and effective method of standardizing and expediting care for orthopedic trauma patients. LEVEL OF EVIDENCE: Therapeutic Level III.