# Diagnostic value of ratio of blood inflammation to coagulation markers in periprosthetic joint infection

## TL;DR

This study explores using ratios of blood inflammation and coagulation markers to help diagnose joint infections after surgery.

## Contribution

It introduces new diagnostic ratios combining inflammation and coagulation markers for periprosthetic joint infection detection.

## Key findings

- PJI patients showed significantly higher levels of multiple inflammation and coagulation markers.
- Ratios like CRP/fibrinogen and ESR/fibrinogen had diagnostic accuracy comparable to traditional markers.
- Combining CRP with ratios improved diagnostic performance similar to combining CRP and ESR.

## Abstract

Assess the feasibility of utilizing the ratio of blood inflammation to coagulation markers as a potential periprosthetic joint infection (PJI) diagnostic tool.

A retrospective analysis was conducted, involving 133 PJI and 93 aseptic loosening patients. Levels of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), platelet count, mean platelet volume, fibrinogen, D-dimer, and ratios of CRP to fibrinogen, ESR to fibrinogen, platelet count and mean platelet volume ratio (PC/MPV), and D-dimer were compared. Receiver operating characteristic curves and Youden’s index were employed to assess the diagnostic efficacy of these biomarkers.

PJI patients had significantly higher levels of CRP, ESR, PC/MPV ratio, fibrinogen, D-dimer, CRP/(PC/MPV) ratio (CPR), CRP/D-dimer, CRP/fibrinogen (CFR), ESR/(PC/MPV) ratio, ESR/D-dimer, and ESR/fibrinogen. Area under the curve (AUC) values for fibrinogen, CRP, and ESR in diagnosing PJI were comparable. AUC values for CPR and CFR were akin to those of ESR. AUC values for combined CRP and CPR, combined CRP and fibrinogen, combined CRP and CFR, and combined ESR and fibrinogen in diagnosing PJI were akin to that of combined CRP and ESR.

Fibrinogen, CPR, CFR, combined CRP and CPR, combined CRP and fibrinogen, combined CRP and CFR, and combined ESR and fibrinogen could be considered as new adjunct markers for diagnosing PJI.