Ankylosing Spondylitis

causes and risk factors
signs, symptoms and diagnosis
pathophysiology
treatments
consequences and course
the patient
health care team
community involvement
resources and references

Ankylosing spondylitis is a chronic inflammatory joint disease mainly affecting the spine and the sacro-iliac joints. It usually occurs in the 20's or 30's and affects men more frequently then women, with a 2-3:1 ratio.

Causes and Risk Factors

AP is strongly associated (90%) with with HLA-B27, which is also associated with reactive arthritis, psoriatic arthritis, and arthritis association with IBD. Together, these are known as seronegative arthritis.

It is believed that HLA-B27 is a marker for immunologic predisposition which needs to interact with one or more infectious triggers.

Signs, Symptoms, and Diagnosis

AP starts in the lower spine and gradually ascends, potentially affecting the entire back. Both synovial (facet and costovertebral) and fibrous (intervertebral discs) joints are affected. Inflammation tends to settle and be replaced by bony ankylosis, or joint fusion. The end stage is a fused spine.

Involvement of non-spinal joints is present in approximately one-third of patients. Aortitis and uveitis can sometimes also occur.

Inflammation of tendinoligamentous insertions is characteristic and can lead to bony spurs during chronic disease, a process known as enthesitis.

Cervical spine fracture and cord injury can occur following relatively minor trauma.

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