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

Table 6

Diagnostic accuracy of PJI diagnosis using serum or synovial fluid procalcitonin.

	Sensitivity	Specificity	AUC	LR+	LR-
Serum PCT (ng/mL)
0.1	65.0 (40.8–84.6)	91.7 (61.5–99.8)	0.78 (0.60–0.91)	7.80 (1.16–52.35)	0.38 (0.21–0.71)
0.3	50.0 (27.2–72.8)	100.0 (73.5–100.0)	0.75 (0.57–0.89)	n/a	0.47 (0.29–0.76)
0.5	40.0 (19.1–64.0)	100.0 (73.5–100.0)	0.70 (0.51–0.85)	n/a	0.60 (0.42–0.86)
Synovial fluid PCT (ng/mL)
0.08	90.0 (68.3–98.8)	83.3 (51.6–97.9)	0.87 (0.70–0.96)	5.40 (1.51–19.30)	0.12 (0.03–0.46)
0.12	80.0 (56.3–94.3)	91.7 (61.5–99.8)	0.86 (0.69–0.96)	9.60 (1.45–63.50)	0.22 (0.09–0.53)
0.16	55.0 (31.5–76.9)	91.7 (61.5–99.8)	0.73 (0.55–0.87)	6.60 (0.97–44.93)	0.49 (0.29–0.82)

AUC: area under curve, LR+: positive likelihood ratio, LR-: negative likelihood ratio, and PCT: procalcitonin.