Ziade N, el Hajj J, Rassi J, et al. - In this study, the clinical characteristics of spondyloarthritis (SpA) patients with and without root joint disease (RJD+ and RJD-) were compared. Researchers further compared the prevalence of RJD across various SpA subtypes and in different world regions, to compare the SpA axial severity and SpA burden between RJD+ and RJD-. They conducted a post-hoc analysis of the ASAS-PerSpA study (PERipheral involvement in SpondyloArthritis), including a total of 4,465 patients with SpA (axial (axSpA), peripheral (pSpA), psoriatic (PsA), inflammatory bowel disease, reactive and juvenile) according to the rheumatologist’s diagnosis. They performed multivariable stepwise binary logistic regression analyses to distinguish factors associated with “RJD”, “hip” and “shoulder” involvement. In comparison with RJD-, RJD+ SpA patients had a distinctive clinical phenotype. Hip involvement, based on the rheumatologist’s diagnosis, was more prevalent than shoulder involvement and was clinically distinct.