Diagnostic Accuracy of the Synovial Fluid α‐Defensin Lateral Flow Test in Periprosthetic Joint Infection: A Meta‐analysis

Abstract

Objectives There is a controversy on the diagnostic reliability and accuracy of synovial fluid α‐defensin in periprosthetic joint infection (PJI). We performed this meta‐analysis to evaluate the diagnostic accuracy of the α‐defensin lateral flow test in PJI. Methods PubMed, Embase, and the Cochrane library were systematically searched, and articles (up to January 2020) on the diagnosis of hip and knee PJIs using the α‐defensin Synovasure lateral flow test were included. The diagnostic accuracy of the α‐defensin lateral flow test in PJI was evaluated using meta‐analysis. The pooled sensitivity, specificity, accuracy, positive and negative likelihood ratio, diagnostic odds ratio, and post‐test probabilities were calculated. Results Seventeen studies including 1443 cases were included. Meta‐analysis showed the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and a diagnostic odds ratio was 0.83 (95% CI 0.77, 0.88), 0.95 (95% CI 0.93, 0.97), 16.86 (95% CI 11.67, 24.37), 0.17 (95% CI 0.13, 0.24) and 85.30 (95% CI 47.76, 152.35), respectively. The area under the hierarchical summary receiver operating characteristic curve was 0.97 (95% CI 0.95, 0.98). Subgroup analysis also confirmed the high efficiency of α‐defensin Synovasure lateral flow test in diagnosing PJIs, irrespective of ethnicity. Fagan's nomogram analysis there was a high positive post‐test probability of 94% and a low negative post‐test probability of 15%. Conclusions We indicated that the α‐defensin lateral flow test had a high accuracy for diagnosing PJI. Large‐scale studies are needed to validate its significance in PJI diagnosis.

Ultrasound evaluations and guided procedures of the painful joint arthroplasty

“…The incidence of PJI following primary TKA and THA is approximately 1-4% and 1% within 2 years, respectively. Furthermore, in regard to revision TKA and THA, these percentages are actually doubled [38].…”

“…More recently, the diagnosis of PJI has shifted focus to biomarkers in the periprosthetic fluid, specifically α-defensin (Synovasure, Zimmer Biomet, Warsaw, IN) [37,38]. αdefensin is an antimicrobial peptide released by neutrophils a b Fig.…”

“…It has been described as an ideal biomarker for PJI due to its high sensitivity and specificity. Quantitative measurements of α-defensin levels in joint fluid have been shown to have a sensitivity ranging from 85 to 100% and similar specificity and accuracy for diagnosing PJI [38]. Furthermore, it has been shown to be effective even in the presence of antibiotics and low virulence organisms and with patient inflammatory comorbidities.…”

“…Furthermore, it has been shown to be effective even in the presence of antibiotics and low virulence organisms and with patient inflammatory comorbidities. The evaluation is typically overnight shipped to an outside facility for processing, although if available, a newer α-defensin lateral flow test can be processed in-house and the same day, with only slightly decreased sensitivity, specificity, and accuracy [38]. An α-defensin test should be included in the clinical diagnostic criteria for PJI when performing an US-guided joint aspiration [37,38].…”

Improve Integration of In Vitro Biofilm Body of Knowledge to Support Clinical Breakthroughs in Surgical Site Infection

“… 101 , 102 Clinical microbiological results can require 2 weeks to return reliable negative results in growth-based assays, but this method is becoming rare because of timing and inaccuracy—some report as much as 56% false-negative output for preoperative synovial fluid aspirate, 60 , 103 , 104 driving a trend toward rapid molecular methods such as alpha-defensin, each with their own weaknesses. 105 Even in the presence of a positive culture, notable challenges such as the heterogeneous growth rates of biofilm bacteria play an important role in determining an effective treatment. 88 Slower growing species can be overwhelmed in planktonic laboratory culture systems, leading to treatments targeting the faster growing CFUs over the slower growing cells, which are more likely to contribute to the underlying chronic condition.…”