The Diagnostic Utility of Synovial Fluid Markers in Periprosthetic Joint Infection: A Systematic Review and Meta-analysis

Abstract

Level II.

Comparison of Synovial Fluid and Serum Procalcitonin for Diagnosis of Periprosthetic Joint Infection: A Pilot Study in 32 Patients

“…Although there is an international consensus for the definition of PJI, no single “gold standard” test currently exists for diagnosing PJI. Recently, many studies have reported the usefulness of synovial fluid cytokines—such as interleukin-6, c-reactive protein, and alpha-defensin—as alternative and better diagnostic markers for PJI compared to the standard technique [ 7 , 8 , 18 – 21 ]. The overall sensitivity and specificity of these markers were more than 80% and 90%, respectively [ 7 ].…”

“…Recent studies regarding the new diagnostic techniques demonstrated that some biomarkers—such as procalcitonin (PCT), interleukin-6 (IL-6), and α -defensin—are helpful and a better marker for PJI [ 4 – 6 ]. Moreover, several studies also showed that the synovial fluid biomarkers obtained directly from the infected joint are more reliable and accurate for diagnosing PJI compared to serum biomarkers and other existing tests [ 7 , 8 ].…”

State-of-the-art diagnosis and surgical treatment of acute peri-prosthetic joint infection following primary total hip arthroplasty

“…Most studies have focused their analysis on synovial CRP, leukocyte esterase, interleukin-6 (IL-6), interleukin-17 (IL-17) and α-defensin. 26 We have been using quantitative synovial CRP (with a threshold level of 9.5 mg/L) as it is as useful as a frozen section to diagnose PJI; synovial CRP and intraoperative frozen section have a similar sensitivity, specificity and predictive value. 27 , 28 Since synovial CRP is easier to obtain, less expensive and less dependent on the technique of obtaining and interpreting a frozen section, we prefer it to the latter to use on a daily basis.…”

“…Nonetheless, we are aware that synovial CRP may result in higher numbers of false positives when compared to α-defensin or IL-17, despite the three of them being of high diagnostic utility. 26 …”

“… 29 - 31 In a systematic review to identify diagnostic technique studies evaluating the accuracy of α-defensin or leukocyte esterase in the diagnosis of PJI, Wyatt et al found that the area under the curve (AUC) for α-defensin and PJI was 0.99 (95% CI 0.98 to 1.00), whereas for leukocyte esterase and PJI it was 0.97 (95% CI 0.95 to 0.98), evidencing a similar diagnostic accuracy. The α-defensin test, Synovasure (Zimmer Biomet), costs around US$93 and is still not available worldwide, whereas synovial CRP costs around US$7 and is obtainable worldwide; thus, since it is cost-effective and non-inferior to the former, 26 many institutions (including ours) keep on selecting it.…”