The Musculoskeletal Infection Society (MSIS) criteria for periprosthetic joint infection include major criteria. Which of the following constitutes a major criterion?

• A Synovial fluid leukocyte count greater than 3,000 cells/µL
• B Synovial neutrophil percentage greater than 80 per cent
• C Serum CRP greater than 10 mg/L
• D Two positive periprosthetic cultures with the same organism ✓

Explanation

MSIS major criteria for PJI are: two positive cultures of the same organism, or a sinus tract communicating with the joint. The other values listed are minor criteria used in the scoring algorithm. Two identical positive cultures remain the strongest single microbiological indicator.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.