Search

Prosthetic joint infections (PJI) can be difficult to diagnose. Studies have shown that we are missing many infections, possibly due to poor diagnostic workup and the presence of culture-negative infection. PJI diagnosis requires a methodical approach and a standardised set of criteria. Multiple PJI definitions have been published with improved accuracy in recent years. The new European Bone and Joint Infection Society definition offers some advantages in clinical practice. It identifies more clinically important infections and accurately defines those with the highest risk of treatment failure. It reduces the number of patients with uncertain diagnoses. Classification of PJIs may offer a better understanding of treatment outcomes and risk factors for failure.

Aims: This study aimed to assess the performance of an automated multiplex polymerase chain reaction (mPCR) technique for rapid diagnosis of native joint septic arthritis., Patients and Methods: Consecutive patients with suspected septic arthritis undergoing aseptic diagnostic joint aspiration were included. The aspirate was used for analysis by mPCR and conventional microbiological analysis. A joint was classed as septic according to modified Newman criteria. Based on receiver operating characteristic (ROC) analysis, the area under the ROC curve (AUC) values of the mPCR and the synovial fluid culture were compared using the z-test. A total of 72 out of 76 consecutive patients (33 women, 39 men; mean age 64 years (22 to 92)) with suspected septic arthritis were included in this study., Results: Of 72 patients, 42 (58%) were deemed to have septic joints. The sensitivity of mPCR and synovial fluid culture was 38% and 29%, respectively. No significant differences were found between the AUCs of both techniques (p = 0.138). A strong concordance of 89% (Cohen's kappa: 0.65) was shown. The mPCR failed to detect Staphylococcus aureus (n = 1) and Streptococcus pneumoniae (n = 1; no primer included in the mPCR), whereas the synovial fluid culture missed six microorganisms (positive mPCR: S. aureus (n = 2), Cutibacterium acnes (n = 3), coagulase-negative staphylococci (n = 2))., Conclusion: The automated mPCR showed at least a similar performance to the synovial fluid culture (the current benchmark) in diagnosing septic arthritis, having the great advantage of a shorter turnaround time (within five hours). Cite this article: Bone Joint J 2019;101-B:288-296.