Spine in ankylosing spondylitis. Coloured X-ray of the lumbar spine of a 44-year-old patient with ankylosing spondylitis affecting the entire lumbar spine. Ankylosing spondylitis is a progressive inflammatory autoimmune disease that mainly affects the joints in the spine an pelvis. In severe cases it may cause complete fusion and rigidity of the spine. Management includes analgesic drugs and regular exercise.