For acute PJI, thresholds of sWBC 10 × 109/L and sPMN > 90% are recommended.90–92 For chronic PJI, sWBC 3 × 109/L and sPMN > 80% are recommended.74,75,88,89 One publication recommended joint aspiration for a CRP > 100 mg/L for acute infection.67 Revision surgery and antibiotics are usually required. This evidence concerns the gene CRP and juvenile polyposis syndrome.