Synovial Fluid Biomarkers for the Diagnosis of Periprosthetic Joint Infection—A Systematic Review and Meta-Analysis of Their Diagnostic Accuracy According to Different Definitions

Background Different synovial fluid biomarkers have emerged to improve periprosthetic joint infection (PJI) diagnosis. The goals of this paper were (i) to assess their diagnostic accuracy and (ii) to evaluate their performance according to different PJI definitions. Methods A systematic review and meta-analysis was performed using studies that reported diagnostic accuracy of synovial fluid biomarkers using validated PJI definitions published from 2010 to March 2022. A database search was performed through PubMed, Ovid MEDLINE, Central, and Embase. The search identified 43 different biomarkers with four being the more commonly studied, with 75 papers overall: alpha-defensin; leukocyte esterase; synovial fluid C-reactive protein; and calprotectin. Results Overall accuracy was higher for calprotectin, followed by alpha-defensin, leukocyte esterase, and synovial fluid C-reactive protein with sensitivities of 78 to 92% and specificities of 90 to 95%. Their diagnostic performance was different according to which definition was adopted as the reference. Specificity was consistently high across definitions for all four biomarkers. Sensitivity varied the most with lower values for the more sensitive European Bone and Joint Infection Society or Infectious Diseases Society of America definitions with higher values for the Musculoskeletal Infection Society definition. The International Consensus Meeting 2018 definition showed intermediate values. Conclusion All evaluated biomarkers had good specificity and sensitivity, making their use acceptable in the diagnosis of PJI. Biomarkers perform differently according to the selected PJI definitions.