On this page:

• Definition
• Causes
• Signs and Symptoms
• Implications
• What You Can Do

Definition

Ankylosing spondylitis is a form of arthritis that involves the joints between the vertebrae of the spine and the joints between the spine and pelvis (sacroiliac joints). Ankylosing spondylitis may also affect other joints, tendons and ligaments.

As the condition worsens and the inflammation persists, new bone forms as a part of simultaneous healing process. The vertebrae begin to fuse together, form vertical bony outgrowths and become stiff and inflexible. Fusion of the vertebrae can also stiffen your rib cage, resulting in restricted lung function and lung capacity.

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Causes

• Ankylosing spondylitis has no known specific cause.
• Genetic factors seem to be involved. It has been observed that the majority of people with ankylosing spondylitis have a gene called HLA-B27. This gene is believed to make people more susceptible to developing ankylosing spondylitis.

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Signs and Symptoms

• Low back pain
• Pain and stiffness in any part or entire spine and other joints of the body.
• The pain is often worse in the morning and following periods of inactivity
• Restricted expansion of chest cage
• Stiff, inflexible spine and forward stooping.
• Fatigue
• Loss of appetite
• Weight loss
• Inflammation of eye (iritis)

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Implications

• Ankylosing spondylitis begins with pain and soreness in the spine. As the disease progresses, the affected bones may fuse together, rendering the joints immobile and causing a stiff, inflexible spine (bamboo spine). This can make walking or standing difficult. The joints may fuse and no additional treatment will help restore mobility. However, if fusion occurs with your spine in an upright position, you can remain more able to perform activities of daily living.

• Inflammation can also spread up your spine and cause the bones in your rib cage to fuse resulting in breathing problems. It becomes difficult to fully inflate the lungs due to restricted movement of the rib cage. Performing daily activities may cause shortness of breath in the absence of any lung disease.

• Inflammation of the heart can lead to valve problems and aortitis (inflammation of the body's largest artery which is called aorta). Another possible complication is aortic valve regurgitation, which occurs when the aortic valve widens and causes back flow of the blood in the heart's lower left chamber.

• In some people with ankylosing spondylitis, cavitary lesions develop in the upper portion of the lungs. These cavities can slowly enlarge over many years and develop infections, most commonly fungal infections of the lung. This complication commonly occurs in smokers.

• Inflammation can also involve other parts of your body, resulting in conditions such as:
  • Inflammatory bowel disease
  • Anemia
  • Painful and inflamed eyes (iritis)
  • Weak and brittle bones (osteoporosis)

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What You Can Do

The goal of treatment is to relieve pain and stiffness and to prevent or delay complications like spinal fusion and deformity. Treatment of ankylosing spondylitis is most successful during it's early stages. Irreversible damage to your joints, such as fusion, especially in positions that limit your function may occur during advanced stage of the disease.

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