PT - JOURNAL ARTICLE AU - Emilio Filippucci AU - Gianluca Smerilli AU - Andrea Di Matteo AU - Walter Grassi TI - Ultrasound definition of enthesitis in spondyloarthritis and psoriatic arthritis: arrival or starting point? AID - 10.1136/annrheumdis-2021-220478 DP - 2021 Jun 24 TA - Annals of the Rheumatic Diseases PG - annrheumdis-2021-220478 4099 - http://ard.bmj.com/content/early/2021/06/25/annrheumdis-2021-220478.short 4100 - http://ard.bmj.com/content/early/2021/06/25/annrheumdis-2021-220478.full AB - Enthesitis has a key role in the diagnosis, classification and management of patients with spondyloarthritis and psoriatic arthritis. Clinical assessment of enthesitis is known to be inaccurate mainly due to its poor specificity. In this context, ultrasound has the potential to improve the evaluation of enthesitis and, therefore, the management of patients with spondyloarthritis and psoriatic arthritis. In this viewpoint, we review the Outcome Measures in Rheumatology (OMERACT) definitions for ultrasound enthesitis, highlighting their current limits and potential implications on rheumatology research and clinical practice.