A new study from the Rothman Orthopaedic Institute at Thomas Jefferson University in Philadelphia, Pennsylvania, may well be the first to tackle the issue of bacterial resistance in periprosthetic joint infection (PJI) across two-stage exchanges.
The work, “Emergence of Antibiotic Resistance Across Two-Stage Revision for Periprosthetic Joint Infection,” appears in the April 7, 2021 edition of The Journal of Arthroplasty.
How often do patients who have had a two-stage revision for chronic periprosthetic joint infection develop a subsequent antibiotic-resistant infection? To answer that question, the Rothman team retrospectively reviewed data from 142 patients who had received a two-stage revision for a chronic culture-positive PJI from January 2014 to May 2019.
The authors found that only 10 of the 142 patients (7.04%) had evidence of antibiotic resistance across their two-stage revision. Said the authors “At reimplantation, 25 (17.6%) patients had positive cultures. Of these, 16 patients presented with a novel organism and 9 patients had positive culture for the same organism as the initial infection.”
“During the entire course of the two-stage revision, including spacer exchanges and irrigation and debridement procedures, 15 (10.56%) patients demonstrated persistent infections, whereas 25 (17.6%) patients presented with novel infections. 26 (18.3%) patients had reinfection of the same joint within one year.”
Co-author Emanuele Chisari, M.D., a research fellow and Ph.D. candidate at Rothman, explained to OTW, “Bacterial resistance rarely occurs between stages across two stage exchanges for periprosthetic joint infection (7% in our cohort), but treatment failure has been reported as high as 50% depending on the sample examined. This huge discrepancy demonstrates that the emergence of resistance occurs only in a small portion of cases, highlighting the need to explore other bacterial mechanisms that may justify the high rate of failure despite treatment.”
More Focus on Microbiological Mechanisms Regulating Antibiotic Resistance
“Future studies should explore mechanisms such as persistence in relation to bacterial periprosthetic joint infection,” added Dr. Chisari. “We speculate that persistent bacteria are responsible for a significant portion of recurrent and persistent PJI. Currently, we know that bacteria purposefully decrease their metabolic activity to survive antibiotic treatment, but further research needs to be conducted to clinically validate these findings.
