Comparison of Synovial Fluid and Serum Procalcitonin for Diagnosis of Periprosthetic Joint Infection: A Pilot Study in 32 Patients

Table 2

The threshold for the minor diagnostic criteria according to the International Consensus Group.

Criterion	Acute PJI (<90 days)	Chronic PJI (>90 days)
Erythrocyte sedimentation rate (mm/hr)	Not helpful; no threshold was determined	30
C-reactive protein (mg/L)	100	10
Synovia white blood cell count (cells/L)	10,000	3,000
Synovial polymorphonuclear percentage ()	90	80
Leukocyte esterase	+ or ++	Same as acute
Histological analysis of tissue	>5 neutrophils/HPF in 5 HPFs (x400)	Same as acute

PJI: periprosthetic joint infection; HPF: high power field.