Ankylosing Spondylitis: What is it, Causes, Symptoms and Treatment


Ankylosing spondylitis (AS), like the name, “it’s a bit complicated,” says spinal surgeon Kaixuan Liu, MD, PhD, who notes that the chronic, inflammatory joint disorder is difficult to diagnose, and its causes still not clearly understood.

What is Ankylosing Spondylitis

Frequently called arthritis of the spine, the debilitating disease initially manifests itself as stiffness, transient pain and inflammation of tendons in the vertebrae of the neck and back, especially in the lowest portion of the spine where it meets the pelvis. If left untreated, the condition can prompt bone-spur formation. The spurs grow and eventually create bony bridges and fusion of vertebrae, making the spine less flexible and forcing a hunched-over posture that may impede breathing, says Dr. Liu, founder and medical director of the Atlantic Spine Center.

As the condition progresses, it affects other tendons and joints like the hips, elbows, knees, and Achilles tendon and various bodily systems, such as the eyes (uveitis), heart, gut, and even the skin (psoriasis), Dr. Liu indicates. He refers to recent studies that show a higher risk of death from heart disease and stroke and a reported 50 percent increase in the risk of blood clots in patients with AS.

Ankylosing Spondylitis Causes

“What happens in AS is that a patient’s immune system becomes dysfunctional and begins attacking healthy tissue in the joints and other areas of the body,” Dr. Liu explains. Bone spurs and spinal rigidity occur when the body attempts to quell inflamed tendons by building up calcium in affected areas.

Ankylosing spondylitis appears to develop most often in younger men between their teen years and mid-40s, although some experts suspect the disease may be underdiagnosed in women.

Besides gender, other potential ankylosing spondylitis causes include genetic variants, alterations in the body’s immune system, ethnicity, family history and environmental factors, such as exposure to certain toxins and infections – even changes in the bacterial population that normally inhabits the colon, says Dr. Liu. A study published online in August 2019 in the journal Plos One contends AS patients are more likely to have had a history of previous inflammatory problems, such as tonsillitis and appendicitis.

The Arthritis Foundation reports that nearly a half million people in the United States struggle with AS, which is a form of spondyloarthritis and which gets its name from the Greek ankylose, meaning to fuse or grow together, and spondylos, which refers to a vertebra. The disease was first described in the 1600s.

Ankylosing Spondylitis Risk Factors

One of the primary risk factors for ankylosing spondylitis is genetics. The condition tends to run in families, and several genes have been identified that are associated with an increased risk of developing ankylosing spondylitis. However, having these genes does not necessarily mean that someone will develop the condition, and not all people with ankylosing spondylitis have a family history of the disease.

Age is another risk factor for ankylosing spondylitis, with most people developing the condition in their late teens or early twenties. Men are also at a higher risk than women for developing ankylosing spondylitis, although the reasons for this are not fully understood.

Other factors that may increase the risk of ankylosing spondylitis include a history of other inflammatory conditions, such as psoriasis or inflammatory bowel disease, as well as a history of certain infections, such as chlamydia.

Ankylosing Spondylitis Symptoms

The most common spondylitis symptoms are back pain and stiffness, which may be worse in the morning or after periods of inactivity. The pain may also be accompanied by fatigue, loss of appetite, and weight loss. As the condition progresses, ankylosing spondylitis can cause the bones of the spine to fuse together, resulting in a loss of mobility and flexibility. This can make it difficult to perform daily activities and may lead to a stooped posture.

Other ankylosing spondylitis symptoms may include pain and swelling in other joints, such as the hips, knees, and shoulders, as well as inflammation of the eyes, bowel, and heart.

Ankylosing spondylitis is a progressive condition, meaning that symptoms may worsen over time if left untreated. However, with proper management and treatment, many people with ankylosing spondylitis are able to lead active and fulfilling lives.

Ankylosing Spondylitis Diagnosis

Although Ankylosing Spondylitis has no known cure, new treatment protocols are proving increasingly effective in controlling the disorder, especially in its initial stages, says Dr. Liu, who emphasizes the importance of early diagnosis by a spinal specialist or rheumatologist. Just this year (2019), the American College of Rheumatology partnered with the Spondylitis.

Association of America and the Spondyloarthritis Research and Treatment Network in issuing updated guidelines for the treatment, assessment and diagnosis of AS.

“AS is suspected as a potential diagnosis if a patient is 40 years of age or under, complains of back pain or pain in the upper buttocks that has persisted for several months, and indicates the pain lessens with exercise and worsens during rest,” Dr. Liu states. “Although no single ankylosing spondylitis test provides a definitive diagnosis of AS, magnetic resonance imaging, X-rays, and ultrasound, as well as a blood evaluation can help determine the presence of ongoing inflammation, especially in the lower back and hips.

“Patients often go to multiple doctors before getting a correct diagnosis,” says Dr. Liu.

Ankylosing Spondylitis Complications

While many people with ankylosing spondylitis are able to manage their symptoms with treatment and lifestyle modifications, the condition can lead to several complications if left untreated or poorly managed.

One of the most common complications of ankylosing spondylitis is a spinal deformity, which occurs as a result of the fusion of the spinal vertebrae. This can lead to a loss of mobility and flexibility in the spine, as well as a stooped posture. In severe cases, the spinal deformity can even affect the function of the lungs and heart.

Another potential complication of ankylosing spondylitis is eye inflammation, which can cause redness, pain, and sensitivity to light. This condition, known as uveitis, can lead to vision loss if left untreated. Ankylosing spondylitis can also increase the risk of osteoporosis, a condition characterized by a loss of bone density and an increased risk of fractures. This is due in part to the chronic inflammation associated with ankylosing spondylitis, which can lead to bone loss over time.

Other potential complications of ankylosing spondylitis may include inflammation of the heart or aorta, bowel inflammation, and nerve damage.

Ankylosing Spondylitis Treatments

Ankylosing spondylitis treatment can include over-the-counter non-steroidal anti-inflammatory medications, as well as physical therapy, which are one way of controlling AS. As scientists learn more about the disease’s causative factors, new spondylitis treatment therapies, including medications targeting dysfunctional immune system cells that promote inflammation, are being developed, he says.

In advanced cases, surgery may be required to repair damaged hips and other joints. Less common is spinal surgery, which is usually reserved for correcting severe downward curving of the spine and other significant spinal deformities caused by the disorder, Dr. Liu says.

Meanwhile, Dr. Liu suggests lifestyle changes that AS patients can make to help control their disease:

  • Exercise regularly to maintain spinal flexibility and increase strength and mobility. He recommended “gentle,” but effective, exercises including walking and swimming.
  • Practice good posture when sitting, standing or walking. Don’t slouch.
  • Sleep on a firm, not hard, mattress and use a pillow for neck support.
  • Stop smoking and reduce alcohol consumption. Recent research indicates smoking impairs patient response to medications for treating inflammatory arthritis.
  • Improve diet and drop the pounds. Extra weight puts added stress on the spine and other joints already affected by the disease.