Fibrinogen performs better than D-dimer for the diagnosis of periprosthetic joint infection: a meta-analysis of diagnostic trials

PURPOSE: D-dimer and fibrinogen, both belonging to coagulation parameters, are controversial for the diagnosis of periprosthetic joint infection (PJI). This meta-analysis was conducted to compare their diagnostic accuracies for PJI by synthesizing currently available evidence. METHODS: Cochrane Library, MEDLINE, Web of Science, and Embase up to March 1, 2020, and other relevant articles were searched. Five hundred and eighty-one articles were identified after initial research, and 11 studies were included finally. No threshold effects were found between studies. The pooled sensitivity, specificity, and positive and negative likelihood ratio were reported to evaluate the diagnostic performance with heterogeneity analysis. Z test statistics was used to analyze the difference of diagnostic performance between D-dimer and fibrinogen. RESULTS: The pooled sensitivity, specificity, and positive and negative likelihood ratio of D-dimer for PJI were 0.79 (95% [CI], 0.72–0.85), 0.77 (0.67–0.84), 3.38 (2.21–5.18), and 0.27 (0.18–0.41), respectively. As for fibrinogen, the pooled sensitivity, specificity, and positive and negative likelihood ratio for PJI were 0.75 (0.68–0.80), 0.85 (0.82–0.88), 5.12 (4.22–6.22), and 0.30 (0.23–0.37), respectively. Great heterogeneity was found in studies for D-dimer, and univariate meta-regression analysis revealed that number of involved joints, disease spectrum, comorbidities influencing D-dimer, and sample sources were the source of heterogeneity. Z test found that the pooled specificity of fibrinogen was significantly higher than D-dimer (0.85 ± 0.01 versus 0.77 ± 0.04, p = 0.03). The pooled positive likelihood ratio of fibrinogen was significantly higher than D-dimer (5.12 ± 0.51 versus 3.38 ± 0.74, p = 0.03). CONCLUSION: Based on currently available evidence, the meta-analysis suggests that fibrinogen performs better than D-dimer as a rule-in diagnostic tool for its higher specificity. However, more prospective trials with larger size are still needed to provide further confirmation. TRIAL REGISTRATION: This meta-analysis was prospectively registered on PROSPERO (International prospective register of systematic reviews), and the registering number was CRD42020177176.