Table 1.

Definition of periprosthetic joint infection^†

Diagnostic Criteria	Concrete Contents
Major Criteria	1) Two positive periprosthetic cultures with phenotypically identical organisms.
	2) A sinus tract communicating with the joint.
Minor Criteria	1) Elevated serum C-reactive protein (CRP) AND erythrocyte sedimentation rate (ESR);
	2) Elevated synovial fluid white blood cell (WBC) count OR + + change on leukocyte esterase test strip;
	3) Elevated synovial fluid polymorphonuclear neutrophil percentage (PMN%);
	4) Positive histological analyses of periprosthetic tissue;
	5) A single positive culture.

^†According to the MSIS criteria, PJI is diagnosed when a patient has one of the two major criteria or three of the five minor criteria