The Role of Sonication in Improving the Detection of Periprosthetic Joint Infections: a Prospective Analysis

The diagnosis of periprosthetic joint infection (PJI) can be particularly challenging in cases of low-grade chronic infection. The suspicion of infection is typically confirmed through cultures of synovial fluid and periprosthetic tissue. However, these methods may not always detect low-grade infections, which can lead to persistent infection and early failure of the prosthesis. The purpose of this study was to evaluate the effectiveness of sonication in enhancing the detection of PJI using polymerase chain reaction (PCR) analysis. A prospective cohort of 26 patients, suspected of having mitigated PJI, underwent surgery at the First Department of Orthopaedic Surgery, St. Anne's University Hospital in Brno between 2019 and 2024. The cohort included 16 women and 10 men, aged 56 to 82 years, with infections involving hip (11 cases) or knee prostheses (15 cases). Standard PCR and sonication followed by PCR were used to confirm PJI. In 20 out of 26 cases, both standard PCR and sonication-assisted PCR detected the infection(p= 0.014). However, in 6 cases, standard PCR failed to identify the pathogen, whereas sonication followed by PCR confirmed the infection. Among these, 4 cases had significantly positive results, and 2 showed weak positivity. The most common pathogens detected were coagulase-negative Staphylococcus (12 cases), followed by Staphylococcus aureus, Pseudomonas aeruginosa, and others. The findings of this study indicate that the integration of sonication with PCR markedly enhances the detection of PJI, especially in instances where standard PCR techniques may be insufficient, such as in low-grade chronic infections.