Ankylosing Spondylitis

Excerpt

Ankylosing spondylitis (AS) is a chronic, inflammatory disease primarily affecting the axial spine that can manifest with a range of clinical signs and symptoms. The hallmark features of the condition include chronic back pain and progressive spinal stiffness. AS is characterized by the involvement of the spine and sacroiliac (SI) joints and peripheral joints, digits, and entheses.

AS often leads to impaired spinal mobility and can result in postural abnormalities. Patients can also experience buttock pain and hip pain. Peripheral arthritis, enthesitis, and dactylitis ("sausage digits") are all associated with AS.

In addition to skeletal involvement, AS can affect various organs outside the joints. These extraarticular manifestations of AS include inflammatory bowel disease (affecting up to 50% of individuals), acute anterior uveitis (seen in 25%-35% of cases), and psoriasis (approximately 10% occurrence).

AS is additionally linked to an increased risk of cardiovascular disease which is believed to stem from the systemic inflammation present in individuals with AS. Pulmonary complications are also associated with AS, as diminished chest wall expansion and limited spinal mobility can predispose individuals to a restrictive pulmonary pattern.

Finally, individuals with AS are at least twice as likely to experience vertebral fragility fractures. Additionally, they face an increased risk of atlantoaxial subluxation, spinal cord injury, and, rarely, cauda equina syndrome.