Joint Infection Diagnostics: Why the Gold Standard Remains Undefeated
Why traditional tests like polymorphonuclear percentage (PMN%) continue to outperform trendy new markers.
Periprosthetic joint infection (PJI) remains one of the most common causes of early revision total joint arthroplasty (TJA). It represents a staggering 14.8% of total hip arthroplasty (THA) and 25.5% of total knee arthroplasty (TKA) revisions performed in the United States. The financial burden is immense, with the direct costs of a single revision for infection ranging from $75,000 to $100,000.
Currently, clinical practice guidelines recommend utilizing serum tests like erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), alongside synovial tests like polymorphonuclear percentage (PMN%), to diagnose PJI. However, no single test or scoring method has been shown to be 100% sensitive and specific in diagnosing PJI. While novel biomarkers like alpha-defensin and calprotectin offer potential for increased detection, they may not be readily available at every institution and can be costly.
This has driven researchers to ask a vital question: Could a synovial marker currently utilized in the standard workup of PJI, without requiring additional infrastructure or cost, be interpreted in a novel way to predict infection?
