What Are the Different Stages of Spondylitis?

Swelling of the joints of the spine causes a condition called ankylosing spondylitis. It is a lifelong, incurable condition that causes mild to severe pain and restricted movement. The exact cause is unknown, but it is genetic. Ankylosing spondylitis affects each person differently and does not follow a clear course.

The Facts

• Ankylosing spondylitis (AS) is a debilitating form of arthritis that affects the spine, according to the Spondylitis Association of America (SAA). It causes inflammation in the vertebrae, leading to pain, limited mobility and complications associated with long-term inflammation. Treatment focuses on pain management and symptom control. Some people have relatively mild symptoms, while others experience increasingly severe symptoms ending with damage to the heart and lungs. Symptoms, whether mild or severe, can be chronic or interrupted by intermittent periods of remission.

Onset

• Inflammation where ligaments attach to the bone, called enthesitis, is the characteristic symptom of AS, reports the SAA. It typically begins with inflammation of the sacroiliac joint---the junction of the spine and pelvis---causing stiffness and pain in the hip and lower back. The pain is usually worse after a period of inactivity, at night and in the morning. In some people, AS does not progress beyond this early stage.

Progression

• As AS progresses, the enthesitis moves up the spine from the sacroiliac joint to the neck. Additional joints become affected, from the hips to the heels, knees, shoulders and chest. One or both eyes often become inflamed and require treatment with corticosteroid eye drops, according to the SAA. Inflammation of the joints between the ribs and spine reduces the chest's ability to expand and results in pain that mimics cardiac angina. The jaw may also be affected, making eating difficult.

Spinal Fusion

• In the most advanced cases, the vertebrae become fused, or ankylosed, states the SAA. Cycles of vertebral inflammation and healing eventually lead to a brittle, bony fusion of the ligaments in the spine, increasing the risk of spinal fracture. The fusion also restricts movement, resulting in a hunched, forward-curving posture, known as kyphosis.

Considerations

• Long-term AS may damage organs and the nervous system, although these complications are rare, the SAA reports. Lengthy treatment with corticosteroids may damage the kidneys. Restricted chest movement decreases the capacity of the lungs, and some people with AS may develop lung scarring, while chronic inflammation near the aortic valve may cause blockages or leaks in the valve. Scarring of nerve bundles may cause neurologic complications such as urinary incontinence or retention, fecal incontinence, pain or weakness in the legs or sexual dysfunction.