Synovial Periprosthetic Infection Markers Show High Variability in Different Clinical and Microbiological Settings

Area of Science:

• Orthopedics
• Infectious Diseases
• Medical Diagnostics

Background:

• Diagnosing periprosthetic joint infection (PJI) is challenging, particularly for low-grade infections.
• Synovial fluid markers like white blood cell count (WBC) and polymorphonuclear percentage (PMN) are crucial when other diagnostic methods are inconclusive.

Purpose of the Study:

• To evaluate the diagnostic utility of synovial WBC and PMN in periprosthetic joint infections (PJI).
• To assess how WBC and PMN levels are influenced by infection virulence, histology, symptom duration, and pathogen detection.

Main Methods:

• Retrospective analysis of 115 patients diagnosed with PJI.
• Comparison of synovial WBC and PMN across different clinical and microbiological subgroups: low- vs. high-virulent pathogens, negative vs. positive histology, symptom duration (≤4 weeks vs. >4 weeks), and pathogen detection (positive vs. negative).

Main Results:

• Higher synovial WBC and PMN were observed in cases with positive pathogen detection and high-virulent pathogens.
• Elevated WBC and PMN levels correlated with shorter symptom duration (≤4 weeks).
• Negative histology was associated with significantly lower WBC and PMN values.

Conclusions:

• Synovial WBC and PMN are influenced by pathogen virulence, histological findings, symptom onset, and successful pathogen detection.
• These synovial markers demonstrate variability, highlighting their complex role in PJI diagnosis.