316. Application of New Consensus Definition Identifies High Numbers of Fracture Related Infections with Negative Cultures

BACKGROUND: Fracture related infection (FRI) is a severe complication in trauma surgery but defining the full impact of these infections has been challenging with the lack of clear diagnostic criteria. This is particularly problematic for culture-negative FRI (CNFRI), which lack pathogen identification to guide antimicrobial therapy. However, new consensus definition and criteria for the diagnosis of FRI (Table) may help reduce the risk of diagnostic error. The purpose of this study was to determine the proportion and clinical characteristics of CNFRI cases at a level I trauma hospital using the new diagnostic criteria. [Image: see text] METHODS: Laboratory reports were used to identify all patients with at least one specimen submitted for microbiology culture by an orthopedic surgeon at our trauma I level hospital in Cincinnati, Ohio during a three-year study period. This cohort was refined by an electronic medical record (EMR) review to select patients that met the diagnostic criteria for suspected/confirmed FRI. The specimen details and results of the cultures were recorded for the first orthopedic surgeon collection for each suspected FRI case. Clinical data, including fracture characteristics, surgical treatment, antibiotic utilization, and patient outcomes were also extracted from the EMR for each case. RESULTS: A total of 246 patients were identified with at least one culture specimen; 35.8% (n = 88) of these were deemed suspected/confirmed FRI based on consensus guidelines. The cultures for the first orthopedic surgery collection on these FRI were negative for 35% (n = 31). The most common location for CNFRI were proximal lower extremity fractures (52%), a distribution different from that of culture positive (Figure). Culture positive FRI were predominated by Staphylococcus aureus (39%) followed by gram negative rods (23%). [Image: see text] CONCLUSION: This retrospective cohort study identified a sizable proportion of CNFRI at our trauma center using the recently published consensus definition. While further analysis is necessary to determine the exact impact of these new criteria, this suggests that clearer definitions may facilitate improved recognition of CNFRI. Because of the relatively high rates of CNFRI, efforts to standardize laboratory diagnostic processes and case management will be required. DISCLOSURES: Henry C. Sagi, MD, FACS, Conexxions (Board Member)GLW trauma (Consultant)GLW trauma (Shareholder)Stryker (Consultant)