Case control study, retrospective comparative study, Level III.

Per the American Association of Orthopaedic Surgeons (AAOS) guidelines or the Musculoskeletal Infection Society (MSIS), 23% of the patients in the present study with PJI would never have been identified. Blood inflammatory markers such as the CRP level and ESR may not be accurate as diagnostic tools in PJI, particularly to identify low-grade and chronic PJI.

dSonication improved the diagnosis of orthopedic implant-associated infections (OIAI). We investigated the diagnostic performance of sonication fluid inoculated into blood culture bottles in comparison with that of intraoperative tissue and sonication fluid cultures. Consecutive patients with removed orthopedic hardware were prospectively included and classified as having OIAI or aseptic failure (AF) according to standardized criteria. The diagnostic procedure included the collection of five intraoperative tissue cultures and sonication of the removed device, followed by conventional culture of the sonication fluid. Cultures were incubated for 7 days (aerobic) or 14 days (anaerobic). In addition, 10 ml of sonication fluid was inoculated into each aerobic and anaerobic BacT/Alert FAN blood culture bottle and incubated in the automated blood culture system for 5 days. Of 75 included patients, 39 had OIAI and 36 AF. The sensitivity of sonication fluid inoculated into blood culture bottles (100%) was higher than that of conventional sonication fluid (87%; P ‫؍‬ 0.05) or intraoperative tissue cultures (59%; P < 0.01). Previous antibiotic therapy reduced the culture sensitivity of conventional sonication fluid to 77% and that of intraoperative tissue to 55%, while it remained 100% for blood culture-inoculated sonication fluid. The time to positivity was shorter in blood culture-inoculated sonication fluid, with detection of 72% of microorganisms after 1 day of incubation, than for intraoperative tissue and conventional sonication fluid cultures, with detection of 18% and 28% of microorganisms, respectively. In conclusion, compared to conventional sonication fluid and intraoperative tissue cultures, sonication fluid inoculated into blood culture bottles improved the diagnosis of OIAI and considerably reduced the time to culture positivity.T he pathogenesis of orthopedic implant-associated infections (OIAI) is related to biofilms, rendering these infections difficult to diagnose. Microorganisms in biofilms are embedded in a hydrated extracellular matrix, adhered to the surface, and transformed in a less metabolically active state than microorganisms in biofilms (1). An accurate diagnosis of OIAI is crucial for treatment success. A combination of various preoperative and intraoperative methods is usually needed for microbiological diagnosis of OIAI (2, 3). However, current diagnostic methods have limited sensitivity, with 10 to 30% false-negative results, and/or lack specificity (2).Research and development of new diagnostic methods aim to improve the diagnostic accuracy and speed of microbial detection in foreign-body infections. Sonication of explanted implants, designed to remove attached biofilms, significantly improved the culture sensitivity compared to that of conventional microbiological methods using synovial fluid or intraoperative tissue samples. Sonication was evaluated in infections involving prosthetic joints, fracture fixation devices, vascular grafts, neurosurgical shunts, breast implants, and cardiac dev...