Ankylosing spondylitis:A form of chronic inflammation of the spine and the sacroiliac joints. Chronic inflammation in these areas causes pain and stiffness in and around the spine. Over time, chronic spinal inflammation (spondylitis) can lead to a complete cementing together (fusion) of thevertebrae, a process calledankylosis.Ankylosing spondylitiscan sometimes be seen in patients withpsoriasisand inflammatory bowel disease (ulcerative and Crohn's结肠炎).
