Anklylosing Spondylitis Definition

Ankylosing spondylitis is a chronic inflammatory disease that affects the joints between the spine and the pelvis as well as the joints between the spinal processes.

The joint between the spine and pelvis is often called the sacroiliac joint, or SI joint. This joint is where the sacrum, just above the tailbone, and the iliac bones, those on either side of the buttocks, meet.

The disease causes pain and inflammation, but may also cause this same effect in other parts of the body as well.

Loss of Mobility

Ankylosing Spondylitis DiagramChronic inflammation in these areas, vertebrae and SI joint, will cause pain and stiffness in and around the spine. Over time a chronic inflammation can lead to the vertebral bodies fusing together which a process called ankylosis. This leads to the loss of mobility at the joints affected.

However, the disease is also systemic, meaning it can affect other tissue around the body. Inflammation and injury can occur in other organs, such as the eyes, heart, lungs and kidneys.

This particular disease shares many features with other arthritic conditions, such as psoriatic arthritis, ulcerative colitis and reactive arthritis. Because of their similarities the conditions are sometimes collectively referred to as spondyloarthropathies.(1)

Unfortunately, ankylosing spondylitis is a chronic condition and while treatments can decrease pain and lessen symptoms, there is no current cure. With early diagnosis and treatment many individuals can prevent complications and physical deformities which can be common.

Symptoms of Ankylosing Spondylitis

Spondylitis ankylosans morbus bechterew anagoriaIndividuals who suffer from ankylosing spondylitis will complain of chronic pain in the lower back and hips especially in the morning or after periods of inactivity.

Early symptoms can also include stiffness in the lower back or hip area. As the disease progresses symptoms will get worse, improve or completely stop.

Individuals also complain of pain in the tendons and ligaments which attach bones between the ribs and spine, joints in the hips, shoulders and knees as well as pain in the eyes.(2)

Ankylosing spondylitis is two to three times more common in men than it is in women. When men are affected they are more likely to have the joints of the vertebral column fused and women are more frequently affected in the joints away from the spine.

Ankylosing spondylitis can also affect children although the most common onset of symptoms is in the 20s and 30s.

In the advanced stages of disease people will experience restricted expansion of the chest wall as the joints between the ribs in the spine are affected; chronic stooping, increase fatigue, weight loss, loss of appetite, bowel inflammation and eye inflammation are also symptoms of advanced disease.

At any time that you have pain in the joints or your back that is unexplained by previous trauma or athletic activity, it is important to see your primary care physician. Only they can help to accurately diagnose the condition and start proper treatment protocols which can reduce inflammation, swelling and progression of the disease.(3)

Genetic Component

Many researchers believe that ankylosing spondylitis has a genetic component. They have found that 90% of those who present with the disease are born with the HLA-B27 gene.

Blood tests have been developed that can detect this marker which helps researchers to further understand the relationship between the gene and the disease.(4)

However, this gene only appears to increase the tendency to develop the disease because other additional factors are necessary for the gene to be expressed or the disease to appear.

Researchers have found that 7% of the total population in the United States carries the HLA-B27 gene and only 1% of the population has a diagnosis of ankylosing spondylitis. On the other hand, only 1.8% of the population in Lapland, a northern Scandinavian region, has the condition while 24% carries the gene.

Risk Factors

At this time researchers have determined only three specific risk factors for the development of ankylosing spondylitis. These are sex (more males than females have the disease), age (between the ages of 20 and 40) and heredity (those who carry the gene may be more susceptible to developing the disease).

This particular condition does not follow a specific course of events, but rather will vary widely between people. However, common complications include difficulty walking or standing, difficulty breathing, inflammation in the eyes, inflammatory bowel disease, anemia and heart problems.

Difficulty walking or standing is a result of the joint fusion in the back and SI joints. Because the inflammation can cause the bones in the rib cage to fuse, it results in breathing problems.


Photo By: Ruth Hartnup

Complications with inflammation in the eyes occur in up to 40% of the individuals who suffer from this disease. It results in rapid onset of eye pain, sensitivity to light and blurred vision.

Individuals who noticed the symptoms should seek the care of their physician immediately in order to decrease the risk of any long-term effects to the eyes.(5)

If the inflammation reaches the heart muscle valve problems can develop resulting in regurgitation and distortion of the essential structures in the heart.

Rare complications include scarring of the heart’s electrical system which causes an abnormal slow heart rate requiring the insertion of a pacemaker.

As the disease advances, individuals can experience deposits of a protein in the kidneys resulting in kidney failure.

Progressive kidney disease will lead to chronic fatigue and nausea requiring consistent kidney dialysis to eliminate the accumulated waste products in the blood. People who have ankylosing spondylitis are not candidates for kidney transplants.

Diagnosis is based on evaluation of symptoms, imaging results and blood tests.

The physician will do a thorough medical history, physical examination, order x-rays to determine any abnormalities of the spine and a blood test looking for the genetic marker. Sedimentation rate (another blood test) is a non-specific blood test looking for evidence of inflammation in the body.

Treatment paths use medications to reduce inflammation and to stop the progression of the disease while physical therapy and exercise will help to support the motion of the joints.

Individuals who suffer from symptoms outside of the spine and SI joint may not respond to nonsteroidal anti-inflammatory treatments alone and may require medications that suppress the body’s immune system, such as sulfasalazine. Another alternative is methotrexate which can be injected or taken orally.

Learn More:

(1) American Family Physician: Spondyloarthropathies

(2) Spondylitis Association of America: Most Common Symptoms

(3) Therapeutic Clinical Risk Management: Update on the Treatment of Ankylosing Spondylitis

(4) Cleveland Clinic: Spondyloarthropathy

(5) NHS Choices: Anykylosing Spondylitis – Complications

Top Image: Medical Art Service, I. Christensen, Wellcome Images

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