# Synovial fluid specific gravity as an inexpensive point-of-care test for diagnosing hip and knee periprosthetic joint infection

## TL;DR

This study shows that measuring synovial fluid specific gravity is a quick and low-cost way to help diagnose joint infections in patients undergoing revision surgery.

## Contribution

The study introduces synovial fluid specific gravity as a novel, inexpensive point-of-care diagnostic tool for periprosthetic joint infection.

## Key findings

- Synovial fluid specific gravity has high diagnostic accuracy (AUC 0.89) for periprosthetic joint infection.
- A threshold of 1.007 provides 100% specificity and 65% sensitivity for infection detection.

## Abstract

Synovial fluid specific gravity (SG) was evaluated as a rapid, inexpensive test for periprosthetic joint infection (PJI) diagnosis in revision arthroplasties. High diagnostic accuracy (area under the curve 0.89; threshold 1.007) with high specificity (100 %) and moderate sensitivity (65 %) was found, supporting its use as an adjunctive point-of-care (POC) tool for PJI.