Table 1.

Characteristics of Patients with Hip and Knee PJI

	Monomicrobial	Polymicrobial	Culture-negative
	n=1,448	n=508	n=111
Age, median (IQR)	68 (60–75)	66 (59–74)	68 (61–76)
Male sex, n (%)	846 (58)	267 (53)	57 (51)
BMI, median (IQR)	32 (28–37)	33 (29–38)	35 (30–40)
ESR, median (IQR)	43 (25–67)	45 (24–75)	36 (25–43)
CRP, median (IQR)	39 (15–100)	39 (15–79)	31 (14–67)
Synovial fluid WBC/µL,	30,009	28,453	12,780
median (IQR)	(9,472–65,036)	(3,028–70,556)	(3,625–44,561)
Sinus tract present, n (%)	184 (13)	142 (28)	20 (18)
Arthroplasty type
Primary arthroplasty, n (%)	956 (66)	337 (66)	91 (82)
Revision arthroplasty, n (%)	492 (34)	173 (34)	20 (18)
Arthroplasty location
Hip joint, n (%)	601 (42)	268 (53)	36 (32)
Knee joint, n (%)	847 (58)	242 (47)	75 (68)

BMI, body mass index; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate

Note: Data available for 987 episodes for BMI, 1910 episodes for ESR, 1888 episodes for CRP, and 1169 episodes for synovial fluid leukocyte count.