SCIENTIFIC POSTER #122 Topic of General Interest OTA 2018 Fracture Blister Fluid: Is It Sterile or Infected? David Hak, MD; Cyril Mauffrey, MD Purpose: The purpose of this study was to determine whether the fluid in clear and blood- filled fracture blisters is sterile or infected. Operative treatment of fractures in the pres- ence of fracture blisters remains controversial as there is concern regarding wound healing complications, especially in the presence of blood-filled blisters that some authors have associated with a greater infection risk. Methods: We aspirated 24 fracture blisters present at the time of surgical treatment in 23 patients. The skin was prepped with betadine prior to aspiration. The fluid was analyzed by Gram stain and routine culture. Patient demographics, fracture classification, mecha- nism of injury, surgical treatment, and subsequent complications were recorded. Results: 12 fractures were due to a high-energy mechanism, while 11 were low-energy in- juries. There were 14 ankle fractures, 4 tibial shaft fractures, 3 pilon fractures, and 2 midfoot dislocations. The blisters were blood-filled in 12 cases, and clear in 12 cases. Gram stains were negative in all cases. Rare polymorphonuclear leukocytes were seen in 15 cases, few in 3 cases, and moderate in 2 cases. Cultures were positive in 6 aspirates, 3 from blood- filled blisters and 3 from clear fluid-filled blisters. Two clear blisters grew coagulase nega- tive Staphylococcus and 1 grew a gram-negative rod. The 3 blood-filled blisters showed polymicrobial growth including Staphylococcus aureus, coagulase negative Staphylococcus, bacillus, and Capnocytophaga. Three patients developed postoperative wound infections. Two of these patients had blood-filled blisters with positive culture results, and 1 had a clear blister with negative culture results. POSTER ABSTRACTS Conclusion: Both clear and blood-filled blister fluid may be colonized with bacteria. Cau- tion should be exercised when operating in the presence of fracture blisters. Both clear and blood-filled fracture blisters should be of concern regarding the potential risk for subse- quent wound infection. See the meeting app for complete listing of authors’ disclosure information. 330.