Ankylosing spondylitis is a type of arthritis that affects the
spine. "Ankylosing" means stiff or rigid,
"spondyl" means spine, and "itis" refers to
inflammation. The disease causes inflammation of the spine and large
joints, resulting in stiffness and pain.
Ankylosing spondylitis may result in erosion at the joint between
the spine and the hip bone (the sacroiliac joint), and the formation
of bony bridges between vertebrae in the spine, fusing those bones. In
addition, bones in the chest may fuse.
Who is affected by ankylosing spondylitis?
AS is more common among young people, ages 16 to 30. The disease
affects more than 500,000 Americans.