Table 1. Proposed definitions of prosthetic joint infection.

Infectious Disease Society of America (IDSA) 2013		Musculoskeletal Infection Society (MSIS) 2011		International Consensus Meeting (ICM) 2013
PJI is present when one of the following criteria is present:		PJI is present when one major criterion is present or four out of six minor criteria exist.		PJI is present when one major criterion is present or four out of five minor criteria exist.
	-Sinus tract communicating with prosthesis
	-Presence of purulence
	-Acute inflammation on histopathological evaluation of periprosthetic tissue
	-Two or more positive cultures with the same organism (intraoperatively and/or preoperatively)
	-Single positive culture with virulent organism
		Major Criteria:		Major Criteria:
			-Two positive periprosthetic cultures with phenotypically identical organisms		-Two positive periprosthetic cultures with phenotypically identical organisms
			-A sinus tract communicating with the joint		-A sinus tract communicating with the joint
		Minor Criteria:		Minor Criteria:
			-elevated CRP and ESR		-elevated CRP and ESR
			-elevated synovial fluid leukocyte count or ++ change on leukocyte esterase test strip		-elevated synovial fluid leukocyte count or ++ change on leukocyte esterase test strip
			-elevated synovial fluid PMN %		-elevated synovial fluid PMN %
			-presence of purulence in the affected joint		-positive histological analysis of periprosthetic tissue
			-positive histological analysis of periprosthetic tissue		-A single positive culture
			-A single positive culture

PJI, prosthetic joint infection; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; WBC, white blood cell; PMN %, polymorphonuclear leukocyte percentage.