What is ankylosing spondylitis kyphosis (ASK)?

Ankylosing spondylitis is a chronic inflammatory disease that affects the axial skeleton, causing pain and progressive stiffness. The age of onset for ASK is around 12 to 15. Common symptoms include lower back pain and pain in the thigh or buttocks areas. As the disease develops, pain could extend to the spine, the ribcage, shoulders, and neck. Thus, it limits the physical activities a patient can do. However, symptoms stop showing at the age of 40 to 50. By then, the normal sagittal physiological curve of patients with advanced ankylosing spondylitis is lost; and kyphosis deformity gradually appears.