Abstract
Background
Periprosthetic joint infection (PJI) remains challenging as a “gold standard” for diagnosis has not yet been established. The aim of this study was to evaluate the accuracy of synovial fluid procalcitonin (SF-PCT) and serum procalcitonin as diagnostic biomarker for PJI and compared their accuracy with standard methods.
Materials and Methods
A single-centered prospective cohort study was conducted between 2015–2017 in 32 patients with painful hip or knee arthroplasty underwent revision surgery. Relevant clinical and laboratory data were collected. PJI was diagnosed based on the 2013 international consensus criteria. Preoperative blood sample and intraoperatively acquired joint fluid were taken for PCT measurement with a standard assay. Diagnostic accuracy was analyzed by the receiver-operating characteristic (ROC) curve and the area under the curve (AUC).
Results
Twenty patients (62.5%) were classified as PJI, and 12 of them (37.5%) were classified as aseptic loosening group. The median age was 68 years (range 38–87 years). The median values of SF-PCT and serum PCT in PJI group were both significant higher than those in aseptic loosening group: the median serum PCT levels (interquartile range: IQR) were 0.33 ng/mL (0.08–2.79 ng/mL) in PJI group compared with 0.04 ng/mL (0.03–0.06 ng/mL), and the median SF-PCT levels (IQR) were 0.16 ng/mL (0.12–0.26 ng/mL) in PJI group compared with 0.00 (0.00–0.00 ng/mL) (p<0.001 both) (Fig 1). SF-PCT, with a cut-off level as 0.08 ng/mL, had a AUC of 0.87, a sensitivity of 90.0% and a specificity of 83.3%, and a negative likelihood ratio (LR-) of 0.12. Whereas serum PCT, with a standard cut-off level as 0.5 ng/mL, had a AUC of 0.70, a sensitivity of 40.0% and a specificity of 100.0%, and a LR- of 0.60. (Fig 2–3)
Conclusion
SF-PCT appears to be a reliable test and could be useful as an alternative indicator or in combination for the diagnosis of PJI.
