Ankylosing spondylitis: Pictures, early signs, and progression in this article, learn about ankylosing spondylitis which is a type of arthritis. What are the symptoms, how is it diagnosed, and how might it be treated? medicalnewstoday.com Spondyloarthritis: Pathogenesis, Clinical Manifestations, Diagnosis and Management The term spondyloarthritis (SpA) is used to describe a heterogeneous group of diseases sharing certain characteristics. emjreviews.com