Synovial Fluid Aspiration Should Not Be Routinely Performed during the Two-Stage Exchange of the Knee

Table 2

Sensitivity and specificity of synovial fluid culture and synovial leukocyte count at interstage aspiration.

	Threshold	Sensitivity	Specificity	Positive Predictive Value	Negative Predictive Value
	culture positive	0.000	0.989	0.000	0.978
	culture positive	0.034	1.000	1.000	0.541
	4450 cells/μl	0.50	0.865	0.167	0.970
	3250 cells/μl	0.357	0.929	0.833	0.591

SFC: synovial fluid culture; SWBCC: synovial white blood cell count.