  ankylosing spondylitis (as, from greek ankylos, fused; spondylos, vertebra; -itis, inflammation), previously known as bechterew's disease (or syndrome) and marie-strÃ¼mpell disease, is a chronic inflammatory disease of the axial skeleton, with variable involvement of peripheral joints and nonarticular structures. as is a member of the group of the spondyloarthropathies, with a strong genetic predisposition. it mainly affects joints in the spine and the sacroiliac joint in the pelvis. in severe cases, it can eventually cause complete fusion and rigidity of the spine. "bamboo spine" develops when the outer fibers of the fibrous ring of the intervertebral disks ossify, which results in the formation of marginal syndesmophytes between adjoining vertebrae. it usually begins in the second or third decade of life and tends to occur more often in males. ==signs and symptoms== thumb|illustration depicting ankylosing spondylitis. * symptoms appear gradually, most commonly between 15 and 45 years of age. * sacroiliitis is usually one of the earliest manifestation of as. the initial symptom is usually a typical chronic dull pain, insidious in onset, felt deep in the lower lumbar or gluteal region, accompanied by low-back morning stiffness. it can occur in in the middle part of the spine or the entire spine, often with pain referred to one or the other buttock or the back of the thigh from the sacroiliac joint. * pain is often severe at rest, but improves with physical act
Ankylosing_spondylitis Arthritis Autoimmune_diseases Rheumatology