Increased Diagnostic Certainty of Periprosthetic Joint Infections by Combining Microbiological Results with Histopathological Samples Gained via a Minimally Invasive Punching Technique.

Background: The diagnosis of low-grade infections of endoprostheses is challenging. There are still no unified guidelines for standardised diagnostic approaches, recommendations are categorised into major and minor criteria. Additional histopathological samples might sustain the diagnosis. However, ambulatory preoperative biopsy collection is not widespread.

Method: 102 patients with hip or knee endoprosthesis and suspected periprosthetic joint infection (PJI) were examined by arthrocentesis with microbiological sample and histopathological punch biopsy. The data were retrospectively analysed for diagnosis concordance.

Results: Preoperative microbiology compared to intraoperative results was positive in 51.9% (sensitivity 51.9%, specificity 97.3%). In comparison of preoperative biopsy to intraoperative diagnostic results 51.9% cases were positive (sensitivity 51.9%, specificity 100.0%). The combination of preoperative biopsy and microbiology in comparison to intraoperative results was positive in 70.4% of the cases (sensitivity 70.4%, specificity 97.3%).

Conclusion: The diagnosis of PJI is complex. One single method to reliably detect an infection is currently not available. With the present method histopathological samples might be obtained quickly, easily and safely for the preoperative detection of PJI. A combination of microbiological and histopathological sampling increases the sensitivity up to 18.5% to detect periprosthetic infection.