Table 2.

The new evidence-based 2018 International Consensus Meeting (ICM) definition for diagnosing periprosthetic joint infection (knee and hips).

Major criteria
1. Two + cultures (same microorganism)	Interpretation
2. Sinus tract communicating with the joint or if joint prosthesis is visualized	At least one of these: Infected
Minor criteria
A. Preoperative diagnosis	Score	Interpretation
Serum
1. ↑CRP (more than 1 mg/dL) OR D-Dimer (more than 860 ng/mL)	2	≥6: Infected
2. ↑ESR (more than 30 mm/h)	1	2–5: Possibly infected
Synovial		0–1: Not Infected
1. ↑Synovial WBC count (more than 3000 cells/μL) or LE ++	3
2. +Alpha-defensin (signal-to-cut-off ratio > 1)	3
3. ↑Synovial PMN (%) (more than 80%)	2
4. ↑Synovial CRP (more than 6.9 mg/L)	1
B. Intraoperative diagnosis		≥6: Infected
1. Preoperative score	–	4–5: Inconclusive
2. +Histology	3	≤3: Not Infected
3. +Purulence	3
4. One + Culture	2

C-reactive protein (CRP); erythrocyte sedimentation rate (ESR); positive (+); ↑: increase; polymorphonuclear neutrophils (PMN).