The relationship between clinical data and US measurements of patients
thumbComparisons
GROUP B
In patients with trigger thumb, the average of C1, C2 and C1/C2 were no statistically different between men and women (Fig. Based on the ROC curve, we chose the diagnostic cut-off value for the C1/ C2 to be 1.362 and 1.153 in order to differ a trigger thumb from children and adults. The sensitivity and specificity of this cut-off value were shown to be 98.0% and 94.1% in adults; 100% and 100% in children. (Fig. 
The sonographic information of measurement in normal thumb and trigger thumbIn each box of the measurements, the mean value ± standard deviation is described in the upper boxC1 = the cross-sectional area of metacarpophalangeal (MCP) joint of flexor pollicis longus (FPL) tendon; C2 = the cross-sectional area of the midpoint of the first metacarpal of FPL tendon; C1/C2 = the ratio of C1 to C2Group1: 0 – 6 year, Group 2: 7–17 year, Group3:18- 40 year and Group4: ≥ 41 yearGroup A: 0- 6 year) and Group B: ≥ 41 yearIn the normal thumb, comparisons of the C1 and C2 in different ages, genders, and left and right hands. The asterisk indicates a significant difference (Comparisons of the C1/ C2 between gender, age, and left and right hands in the normal thumbComparisons of the C1, C2 and C1/ C2 in the trigger thumbComparisons of C1/ C2 in the normal thumb and trigger thumb. The asterisk indicates a significant difference (The measurements of the C1/ C2 in normal thumb are plotted against the measurements in trigger thumb. 