Table 1 The Modified Musculoskeletal Infection Society (MSIS) criteria
From: Neutrophil to lymphocyte ratio as a predictor for diagnosis of early Periprosthetic joint infection
PJI is present if one of two major criteria or three of five minor criteria exists: | |||
Major criteria | 1. A communicating sinus tract with the prosthesis; or | ||
2. Two positive periprosthetic cultures with phenotypically identical organisms | |||
Minor criteria | Having three of the following minor criteria: | Acute PJI (< 90 days) | Chronic PJI (> 90 days) |
1. Serum CRP or ESR | ESR: no threshold | ESR: >30mm/h | |
2. Synovial fluid WBC count or | 10,000 cells/μL | 3000 cells/μL | |
Changes in leukocyte esterase test strip | + or ++ | + or ++ | |
3. Synovial fluid PMN % | 90% | 80% | |
4. Positive histologic analysis of the periprosthetic tissue | > 5 neutrophils per high-power field (× 400) | > 5 neutrophils per high-power field (× 400) | |