Wilson A, et al. Paper 925. Presented at: Musculoskeletal Infection Society Annual Meeting; Aug. 5-6, 2022; Pittsburgh (hybrid meeting).
Wilson reports no relevant financial disclosures.
Researchers at the University of Pittsburgh Medical Center found a 5% incidence of unexpected positive sonication cultures with at least five colony-forming units in patients undergoing presumed aseptic revision total joint arthroplasty.
“The goals of this study were threefold: first, to report our rate of unexpected positive cultures; secondly, to report on how we are treating these patients and; lastly, to compare the rates of failure for patients with and without unexpected positive sonication cultures,” Alan Wilson, MD, a fifth-year resident at the University of Pittsburgh Medical Center, told Healio in a video interview about results presented at the Musculoskeletal Infection Society Annual Meeting.
In a retrospective chart review for 424 patients who underwent presumed aseptic revision hip or knee arthroplasty from 2016 to 2019, Wilson noted 21% of patients had positive sonication cultures, which included patients with a single colony-forming unit.
“When we looked more closely at patients who had at least five colony-forming units, which we have previously reported is the optimal threshold for defining a positive result at our institution, we found a combined incidence of 5%,” Wilson said.
He added unexpected positive cultures were more commonly found among patients with a history of prior revision surgery or patients with a prior periprosthetic joint infection. Among 208 patients who had at least 1 year of follow-up data, patients with and those without unexpected positive cultures had no significant differences in rates of repeat revision or treatment for infection, according to Wilson.
“However, there was a significant loss to follow-up that limits the interpretation of these outcomes,” Wilson said.