Plasma Fibrinogen as a Diagnostic Marker of Infection in Patients with Nonunions

Figures & data

Table 1 Patient Characteristics of the Two Groups

	Group A (n = 55)	Group B (n =91)	P-value
No of women	4/51	15/76	0.109
Age (year, mean ± SD)	48.9 ± 15.0	46.5± 13.3	0.309
BMI (kg/m2, mean ± SD)	24.1±3.7	23.8±3.5	0.125
Nonunion site (Lower Extremity)	49/6	77/14	0446

Notes: Group A = infected nonunion; Group B = aseptic nonunion. *P<0.05 indicated significances.

Abbreviation: BMI, body mass index.

Table 2 Comparison of the Tested Markers in the Two Groups

	Group A (n = 55)	Group B (n = 91)	P-value
WBC (10^9/μL)
Median	6.5	6.4	0.087
P25, P75	5.5 ~ 8.2	5.5 ~ 7.1
CRP (mg/L)			<0.001*
Median	6.6	3.5
P25, P75	3.6 ~ 17.5	2.6 ~ 5.1
ESR (mm/hr, median)			<0.001*
Median	23.0	6.0
P25, P75	13.0 ~ 34.0	4.0 ~ 9.0
Plasma Fibrinogen (mg/L)			<0.001*
Median	3.3	2.4
P25, P75	2.8 ~ 5.1	2.0 ~ 2.8

Notes: Group A = infected nonunion; Group B = aseptic nonunion. *P<0.05 indicated significances.

Abbreviations: WBC, white blood cell; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate.

Figure 1 ROC curve shows the infected nonunion predictive value of WBC, CRP, ESR, and plasma fibrinogen.

Abbreviations: WBC, white blood cell; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate.

Table 3 The Diagnostic Value of Tested Markers in Patients

Variables	AUC(95% CI)	Optimal Cutoff Value	Sensitivity	Specificity	PPV	NPV
WBC	0.585 (0.484–0.685)	7.65×10^9/L	0.382	0.857	0.618	0.696
CRP	0.716 (0.624–0.807)	6.35 mg/L	0.545	0.868	0.714	0.612
ESR	0.885 (0.830–0.940)	17.5 mm/h	0.691	0.923	0.783	0.674
Plasma Fibrinogen	0.816 (0.747–0.885)	2.75 g/L	0.783	0.824	0.729	0.862

Abbreviations: WBC, white blood cell; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; AUC, areas under the curve; CI, confidence interval; PPV, positive predictive value; NPV, negative predictive value.