Ultrasonographic evaluation of Achilles tendon: Is there any difference between ankylosing spondylitis, non-radiographic axial spondyloarthropathy and controls?

AS and nr-axSpA patients were found to be similar in various clinical, functional, and US findings indicating that these 2 entities are different phenotypic reflections of the same disease spectrum. The positive correlation between PDUS and MASES scores in AS patients substantiate the performance of MASES in evaluation of entheseal activity.