What are MSIS major PJI criteria?

Major criteria (either alone = definite PJI): (1) Communicating sinus tract or fistula to the prosthesis, (2) Same organism on 2+ periprosthetic tissue or fluid cultures. If neither met, scoring minor criteria (serology, synovial WBC, histology, cultures, intraoperative purulence).

What synovial fluid WBC and PMN% diagnose acute vs chronic PJI?

Acute PJI ( 10,000 cells/uL or PMN% >90%. Chronic PJI (>90 days): WBC >3,000 cells/uL or PMN% >80%. Values vary by joint (hip vs knee) and inflammatory arthritis background.

What serum markers support PJI diagnosis?

ESR >30 mm/h (+1 point), CRP >1 mg/dL (+2 points), d-dimer >860 ng/mL (+1 point), fibrinogen >405 mg/dL (+1 point). Alpha-defensin in synovial fluid is the highest-specificity single test (>95%) for PJI.

MSIS/ICM Periprosthetic Joint Infection Criteria Score

Apply MSIS/ICM 2018 periprosthetic joint infection (PJI) major and minor criteria. One major criterion (draining sinus/fistula, 2 cultures same organism) or 3 minor serology/synovial criteria (>4 points) establishes PJI diagnosis.

⚕ Clinical Disclaimer: These calculators are for educational and reference purposes only. Always verify results with qualified clinical judgment and current clinical guidelines. Do not use as a sole basis for medical decisions.

How to Use

Enter the values for the scenario you are assessing. Apply MSIS/ICM 2018 periprosthetic joint infection (PJI) major and minor criteria. One major criterion (draining sinus/fistula, 2 cultures same organism) or 3 minor serology/synovial criteria (>4 points) establishes PJI diagnosis. Use the pji diagnosis criteria result to inform your calculation.

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