AB0708 Differences in Localization and Activity of the Entheseal Involvement between Non-Radiographic and Radiographic Axial Spondyloarthritis by the Ultrasound Assessment

Background Peripheral entheseal involvement seems to be an important sign of spondyloarthritis (SpA). It may occur in patients with long-term as well as newly diagnosed disease and in those with definite ankylosing spondylitis (AS) and without radiological sacroiliitis, non-radiographic axial SpA (nr-ax-SpA). The clinical severity may not correlate with local tendon changes and ultrasound detection should be a useful tool for active changes assessment. Objectives To search for active and non-active entheseal changes by an ultrasound detection in four localization: Achilles tendon, patellar ligament, plantar aponeurosis and quadriceps insertion in patients suffering from newly diagnosed SpA: nr-ax-SpA and definite AS. Methods The total of 34 patients suffering from newly diagnosed SpA (with established diagnosis maximally within 2 years) underwent the clinical and ultrasound examination. Disease activity was determined by ASDAS CRP and BASDAI. Conventional two-dimensional power Doppler ultrasonography was performed by one radiologist/musculoskeletal ultrasound specialist. Six ultrasound changes like tendon structural changes and thickening of tendon insertion, calcifications, bone erosions, bursitis, and Doppler signal was determined in four locations and Naredo et al. classification (1) for active/non active lesions was used. The χ2 test for comparison each group, Fisher exact test and correlation for activity a tendon changes was used. Results Altogether, 26 nr-ax-SpA patients (average age: 35.44±8.64) and 8 AS patients (average age: 31.63±6.12); BASDAI 3.27±0.56 and 1.95±0.2 respectively, ASDAS CRP 1.88±0.63 and 2.07±0.29 respectively, underwent the ultrasound detection for entheseal changes. 5 (19.20%) nr-ax-SpA and 3 (37.5%) AS patients have Doppler positive changes in any locations (p=ns), whereas the non-active changes were found in 21 (80.77%) nr-ax-SpA a 8 (100%) AS patients (p=ns). The Achilles tendon and the patellar ligament were the most common involved sites in both patients groups, nr-ax-SpA (32.70 and 26.92%, respectively) and AS (50.0 and 25.0% respectively), all p=ns. Interestingly, when we look for every changes in all tested tendons there were non-active changes in only 37.90% nr-ax-SpA compared to 71.88% AS (p