Low sensitivity of histology to predict the presence of microorganisms in suspected aseptic loosening of a joint prosthesis.

Intraoperative histology has a high specificity and sensitivity when a septic prosthesis loosening is suspected. However, its usefulness to predict the presence of microorganisms when aseptic loosening is suspected is not well defined. Intraoperative histology and cultures from periprosthetic tissue of 61 revision arthroplasties performed owing to suspected aseptic loosening were retrospectively reviewed. Frozen sections were evaluated following Mirra's criteria (adapted by Feldman). Culture was considered positive when the same microorganism was isolated in at least two samples. The cultures were positive in 12 cases and coagulase-negative staphylococci were the most common microorganisms (11 cases). In six out of 12 cases (50%), the histology revealed more than five polymorphonuclear leukocytes per high-power field. The sensitivity, specificity, positive and negative predictive value of histology to detect the presence of microorganisms was 50, 81, 40 and 86%, respectively. In conclusion, intraoperative histology using Mirra's criteria had a low sensitivity to predict the presence of microorganisms in samples from suspected aseptic prosthetic loosening.