The Ongoing Struggle to Find a Gold Standard for PJI Diagnosis.

Periprosthetic joint infection (PJI) is a devastating complication of joint arthroplasty surgery that is difficult to both diagnose and treat. Misdiagnosing a prosthetic infection has terrible consequences for both the patient and healthcare system. No currently used diagnostic test fulfills the requirements to be considered a gold standard. This shortcoming has been overcome through the implementation of multi-criteria diagnostic protocols elaborated by societies including the Infectious Diseases Society of America, International Consensus Meeting and European Bone and Joint Infection Society, using a combination of clinical, paraclinical and molecular findings in order to achieve the best accuracy in diagnosing PJI. This review aims to survey the current state of the techniques and technologies used for the diagnosis of PJI, investigating the accuracies of serum biomarkers (e.g., C-reactive protein, Interleukin-6, procalcitonin, D-dimers, Serum Intercellular Adhesion Molecule-1), synovial biomarkers (e.g., Antimicrobial peptides, lipocalin-2, leukocyte esterase, calprotectin), tissue biomarkers (e.g., Toll-like receptors, CD15) and advanced molecular techniques (e.g., Polymerase chain reaction, Metagenomic next-generation sequencing), as well as describing their ongoing limitations. In the search for an accurate, inexpensive and fast diagnostic test for PJI, we conclude that the accuracies of the currently studied biomarkers could be further enhanced through the development of novel detection technologies.