In synovial fluid, the mean PCT values in the aseptic group were significantly higher (p <  0.001) than those of PJI group (PJI 2.7 ± 1.4 ng/mL (0.53–9.7) vs. aseptic 8.7 ± 2.5 ng/mL (0.25–87.9)). This evidence concerns the gene CALCA and juvenile polyposis syndrome.