Is synovial calprotectin lateral flow test a reliable intraoperative biomarker for periprosthetic joint infection? A systematic review and meta-analysis

TL;DR

This study evaluates the synovial calprotectin lateral flow test as a reliable intraoperative tool for diagnosing joint infections during surgery.

Contribution

The study provides a meta-analysis of synovial calprotectin LFT's diagnostic accuracy for PJI, highlighting its potential as a real-time surgical aid.

Findings

Synovial calprotectin LFT showed 88% sensitivity and 89% specificity for detecting periprosthetic joint infection.

A cutoff of ≥ 50 mg/L improved diagnostic performance across all metrics.

The test has an area under the curve of 0.94, indicating strong diagnostic accuracy.

Abstract

Periprosthetic Joint Infection (PJI) remains one of the most challenging complications in arthroplasty, often leading to diagnostic uncertainty and suboptimal treatment decisions. Synovial calprotectin has emerged as a promising biomarker, with the lateral flow test (LFT) offering real-time results for intraoperative decision-making. This meta-analysis aimed to evaluate the diagnostic accuracy of intraoperative synovial calprotectin LFT in detecting PJI.

A systematic review and meta-analysis were conducted according to PRISMA guidelines. Thirteen studies comprising 990 patients were included. Pooled sensitivity, specificity, positive and negative predictive values (PPV, NPV), likelihood ratios (LR+, LR−), diagnostic odds ratio (DOR), and area under the curve (AUC) were calculated using a random-effects model. Subgroup analyses were performed based on test kit type and calprotectin cutoff values.

The pooled sensitivity and specificity of synovial calprotectin LFT were 88% (95% CI: 82–92%) and 89% (95% CI: 83–93%), respectively, with an AUC of 0.94. The DOR was 56.1 (95% CI: 28.4-110.8). The ≥ 50 mg/L cutoff subgroup demonstrated superior diagnostic performance across all metrics. Despite subgroup analysis, heterogeneity remained high (I² = 74.1%), likely due to differences in reference standards, joint types, and study design.

Intraoperative synovial calprotectin LFT is a highly accurate and rapid diagnostic tool for PJI, with strong applicability in real-world surgical settings. Its cost-effectiveness and ease of use support its integration as a valuable adjunctive marker within standard diagnostic algorithms, providing supplementary evidence when conventional criteria remain inconclusive.

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