CRP and infection: Current modalities to treat PJI include a single-stage or a two-stage revision surgery, based on the duration of symptoms and time to evaluation.6,7 The Musculoskeletal Infection Society developed criteria, such as positive cultures, presence of a sinus tract, elevated serum CRP and ESR, and synovial fluid laboratory test results, to diagnose PJI and to help surgeons determine if surgical intervention is necessitated as shown in Figure 1.