The fate of elbows with unexpected positive intraoperative cultures during revision elbow arthroplasty

Background: An intraoperative culture sample obtained during revision elbow arthroplasty that is unexpectedly positive poses a dilemma for the surgeon. The purpose of our study was to determine the prevalence of positive cultures during revision elbow arthroplasty when infection is not suspected preoperatively, and the long-term implications of these positive cultures. Methods: Two hundred and thirteen consecutive revision elbow arthroplasties were performed at our institution between 2000 and 2007. Of these, sixteen patients had unexpected positive intraoperative cultures. Results: The majority of cultures grew either Staphylococcus epidermidis or Propionibacterium acnes. Twelve patients had more than two years of follow-up. One of the twelve patients was treated as for an infection because of unexplained early implant loosening and the isolation of Staphylococcus epidermidis. Ten of the twelve elbows were treated as "contaminants" and did not receive long-term antibiotic treatment. Nine of these ten remained infection-free at the time of the final follow-up, while the remaining one developed an infection with a different organism. Conclusions: In our series, there was a 7.5% chance of encountering an unexpected positive result on intraoperative culture at the time of revision elbow arthroplasty. Themajority of patients were successfully treated without antibiotics with a low rate of failure. A minority were considered as infections, typically presenting with unexplained early loosening and isolation of an organism on solid culture medium. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.