Background: Peri-prosthetic joint infection (PJI) is a serious and frequent complication of total joint arthroplasty (TJA). Recently, synovial fluid leukocyte esterase (LE), measurement of which is convenient and fast, has been examined as a marker of PJI. We summarized the articles describing synovial fluid LE as a biomarker for the diagnosis of PJI and assessed its diagnostic value in patients suspected of having PJI.
Methods: We searched with appropriate key words in PubMed, Embase, Web of Science, the Cochrane database, and Science Direct. Eligible studies providing sufficient data to construct 2 × 2 contingency tables were chosen on the basis of several criteria, and the quality of the chosen studies was assessed. The pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated for those studies. The summary receiver operating characteristic (SROC) curve and the area under the SROC (AUSROC) were used to evaluate the overall diagnostic performance of LE.
Results: Eleven studies were found suitable for this systematic review. Among them, eight articles with a total of 1,011 participants qualified for meta-analysis. The pooled sensitivity, specificity, and DOR were 0.90 (95% confidence interval [CI] 0.76-0.96), 0.97 (95% CI 0.95-0.98), and 310.76 (95% CI 103.86-929.88), respectively. The SROC was 0.98 (95% CI 0.96-0.99). Sub-group analysis indicated that the sample inclusion criteria might be the main source of heterogeneity. Publication bias was suggested by an asymmetrical funnel plot (p = 0.144).
Conclusion: Although the result of synovial fluid LE assay can be influenced by sample-related factors, it is more specific as a means to exclude PJI.
Keywords: leukocyte esterase; peri-prosthetic joint infection; synovial fluid.