CORR Insights(®): Does Preoperative Antimicrobial Prophylaxis Influence the Diagnostic Potential of Periprosthetic Tissues in Hip or Knee Infections?

Abstract

P rosthetic joint infection (PJI) often is initially treated as aseptic loosening, but this misdiagnosis can result in early failure, additional revision procedures, and unnecessary damage to soft-tissue and bone. Additionally, the number of revisions performed is a risk factor for the emergence of antibiotic resistance, making future antimicrobial treatments more difficult [1]. Researchers are currently investigating better ways to ensure that the diagnosis of PJI is not missed. Recent tests have shown promise in proving the absence of bacteria in preoperative joint aspirates [3]. But in case of infection, they cannot identify the causative bacteria, which is crucial for planning of the treatment. For an established PJI caused by an unknown microorganism, twostage exchange remains the standard treatment option in order to give an appropriate therapy before reimplantation [4]. However, there is increasing evidence that one-stage exchange can be a reliable and safe procedure even in these cases, provided that there is a low probability of infection with difficultto-treat pathogens [2]. Bedencic and colleagues showed that timely antibiotic prophylaxis does not impair the identification of the causative microorganism in cases with suspected PJI. The authors suggested that prophylaxis should not be postponed in order to minimize the risk of a new infection. However, this strategy may prevent the identification of difficult-to-detect bacteria. In the present study, two cases caused by Propionibacterium acnes and one case caused by Corynebacterium species were detected before, but not after, a single prophylactic dose of cefazolin. Therefore, even if antibiotic prophylaxis did not appear to harm the yield of positive cultures in this small trial, a larger study may reveal a diagnostic problem.