Application Study Of Ultrasonography For Sacroiliitis And Lower Limbs Enthesopathy In Axial Spondyloarthropathy

Object:To observe the ultrasonography of sacroiliac joints(SIJ) and lower limbs enthesis in patients with early axial spondyloarthropathy(ax SpA), investigating the value of ultrasound in diagnosing of early axSpA and evaluating disease activity.Methods:Early axSpA patients in department of Rheumatology were selected from March2014 to February 2015 for the study. 19 cases were account into active group and 25 were inactive group base on clinical and laboratorial results. 30 cases of asymptomatic volunteers matched by age and gender were included as a control group. All of the patients and controls independent underwented ultrasonographic examinations of bilateral SIJ and lower limbs enthesis. The following ultrasonic index were recorded and analyzed:(1) the differences of vascularization demonstrated rate,the degree of blood flow(a 4-point scale semi-quantitative) and resistances index(RI)in SIJ among the three groups;(2) the diagnosis efficacy of blood flow RI value in SIJ to active ax SpA and the cut-off point;(3) the commonly abnormalities and frequent involvements of entheseal sites at lower limbs in patients with early ax SpA;(4) the differences of in the positive rates of enthesis by ultrasonography, the proportion of abnormalities and the involved entheseal sites among the three groups.Results:(1) Vascularization demonstrated rate, the degree of blood flow and RI value of SIJ in active group of early ax SpA patient was significantly different with the other two groups(p<0.01). The difference of above indexes was not statistically significant between inactive and normal groups(p=0.74,0.71,0.71).(2) When taking blood flow RI value of SIJ as standard for diagnosing of activeax SpA, the area under the ROC curve is 0.893, RI=0.64 was the cut-off point, and its sensitivity and specificity was 87.1%,76.9%, respectively.(3) Varieties of abnormal sonographic were observed in early ax SpA patients such as bursitis, tendon thickening, bony erosion, calcification within the tendon,enthesophyte(bony spur) and Doppler signals. Bursitis was the most commonly abnormality in lower limbs enthesopathy; the Achilles distal was the most frequently involved entheseal sites.(4) The differences of in the positive rates of enthesis by ultrasonography in activity group, inactive group of early ax SpA patients and the controls was 44.7%,31.2% and 6.0%, respectively. The above index was statistically different between any two groups(p<0.00). The proportion of power Doppler ultrasonography(CDPI)flow signals in all abnormalities were statistically different(x2=4.6, p=0.03) while the involved entheseal sites were same between the two groups.Conclusions:(1) Vessel demonstration rate of SIJ in active ax SpA patients was high which mainly concerned with much richness blood flow signals and lower RI, while the control group and the inactive group was on the contrary.(2) Ultrasound can display the enthesopathy effectively in early axSpA patients,of which the bursitis was most common; the incidence of enthesopathy were not identical in entheseal sites, of which the Achilles distal was most likely involved.(3) The blood flow RI of SIJ and the PDUS flow signals of enthesis could be reference indicators to active disease, providing an objective, visual evidence for clinical to diagnosis axSpA early and assess inflammatory activity.