Table 1. Musculoskeletal Infection Society (MSIS) definition of peri-prosthetic joint infection [14].

ESR: Erythrocyte Sedimentation rate, CRP: C-reactive protein

PJI may be present in fewer than four of these criteria are met.

Musculoskeletal Infection Society (MSIS) definition of peri-prosthetic joint infection.

1. There is a sinus tract communicating with the prosthesis; or

2. A pathogen is isolated by culture from at least two separate tissue or fluid samples obtained from the affected prosthetic joint; or

3. Four of the following six criteria exist:

1. Elevated serum erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP) concentration,

2. Elevated synovial leukocyte count,

3. Elevated synovial neutrophil percentage (PMN%),

4. Presence of purulence in the affected joint,

5. Isolation of a microorganism in one culture of periprosthetic tissue or fluid, or

6. Greater than five neutrophils per high-power field in five high-power fields observed from histologic analysis of periprosthetic tissue at ×400 magnification.