Microbiological diagnosis of implant-associated infections : Retrospective analysis of 133 patients in an arthroplasty center

Abstract

Because standardized microbiological cultures of puncture fluids and tissue samples often do not provide pathogen detection in implant-associated infections, sonication and polymerase chain reaction (PCR) are used additionally today. Pathogen spectra and previous microbiological standards are examined for agreement of results using the new methods sonication and PCR. In this descriptive, retrospective observational study, we evaluated the data of 133patients in whom ajoint prosthesis, osteosynthesis material or aspacer was removed during revision surgery with suspected implant-associated infection and sent for sonication. Pathogen detection was achieved by culture of peri-implant material in 40.1% and by sonication in 42.5%. In each case, coagulase-negative staphylococci were detected most frequently. Overall, the results were consistent in 71.7% of cases. In the discrepant cases, more anaerobes could be detected by sonication, especially for osteosynthesis material and knee prostheses. PCR analyses in 21cases showed pathogen detection in 14.3% and agreement with the results of peri-implant tissue culture and sonication in 57.1% and 66.7%, respectively. The present results indicate again in sensitivity of sonication, especially for anaerobes that are difficult to grow, and again in specificity through sonication. PCR analyses should be reserved for specific questions.