Anklosing Spondylitis Ankylosing spondylitis is an inflammatory condition that involves the spine and skeleton of the head and trunk. The disorder causes inflammation and pain in joints in the spine, pelvis and other parts of the skeleton. In addition, parts of the spine, the sacroiliac joints where the hips join the lower back, or the hips may fuse, or grow, together. Signs & Symptoms Pain Stiffness, especially in the morning, Functional limitation, When the disorder affects the spine, it also may result in progressive deformity including curvature of the back, called kyphosis, and the inability to stand up straight. Diagnosis The first clue in diagnosing ankylosing spondylitis is the presence of symptoms, especially back pain. In addition, X-rays are taken to look for signs of the disorder, such as fused joints. A blood test for the HLA-B27 gene, which is found in about 90 percent of the people with ankylosing spondylitis, also may be performed. Howeve...