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Ankylosing Spondylitis

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What is Ankylosing Spondylitis?

What is Ankylosing Spondylitis?

Ankylosing spondylitis (AS) is a type of arthritis that causes inflammation in the ligaments and joints of the spine. Other surrounding joints can also be affected. The disease can result in long-term lower back and hip pain that comes and goes.

Ankylosing means rigid or stiff. Spondylitis means inflammation of the spine. Over time, the inflammation of advanced ankylosing spondylitis can cause stiffness or fusing of the vertebrae, resulting in limited spine flexibility and a hunched posture.

Ankylosing spondylitis is a fairly rare condition affecting approximately 1 in 1,000 people. Men are more likely to have AS than women. There is no direct cure, but there are treatments that can help reduce pain and symptoms and possibly slow its progression.

Types of Ankylosing Spondylitis

Types

Ankylosing spondylitis (AS) is a form of axial spondyloarthritis (axSpA), an overall term used to categorize arthritic spine conditions. Most people experience back pain during their lifetimes, but ankylosing spondylitis is a specific type of axSpA that is diagnosed and treated differently.
There are two types of axial spondyloarthritis (axSpA):

  • Non-radiographic axSpA (nr-axSpA). Nr-axSpA is when back and pelvic pain exists, but damage to the bones and joints cannot be detected by an X-ray.
  • Ankylosing spondylitis (AS) or radiographic axSpA. Ankylosing spondylitis causes damage to the joints and bones of the spine that can be seen on an X-ray. Non-radiographic axSpA can eventually develop into AS.

Ankylosing spondylitis is one of the more severe subtypes of axSpA.

Stages of Ankylosing Spondylitis

Stages

The progression of ankylosing spondylitis varies from case to case. Some people may only experience sporadic stiffness and back pain. Other forms can progress to cause impaired movement, a hunched appearance, and digestive, eye, and nerve issues.

  • Early stage ankylosing spondylitis. In the beginning, AS can cause inflammation along the spine—often starting in the sacroiliac joints at the base of the backbone. The resulting pain can start on one side and gradually spread to the other, and occasionally to the buttocks. The flare-ups of pain can come and go.
  • Progressing ankylosing spondylitis. Over the years, AS can move from the base of the spine up to the neck. The inflammation can occur where your ligaments and tendons attach to bones (the entheses), causing pain in the hips, ribs, shoulders, thighs, and heels. AS inflammation may be associated with inflammatory bowel disease (IBD), psoriasis, and eye inflammations.
  • Advanced ankylosing spondylitis. Advanced AS can result in “bamboo spine,” where the vertebrae in the backbone become fused together. Fusion can result in more pain, a curved spine, difficultly moving, and higher risk for falling and fractures. It can also restrict the ribcage, making it difficult to breathe.

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Signs & Symptoms of Ankylosing Spondylitis

Symptoms

Early stage ankylosing spondylitis symptoms involve pain in the lower back and hips. Pain typically flares up while sleeping, first thing in the morning, and after periods of inactivity. There can be sporadic intervals where the symptoms improve, get worse, or go into remission.

An early ankylosing spondylitis symptom checklist can include:

Symptoms of progressing to advanced spondylitis can include:

  • Abdominal pain and diarrhea
  • Skin rash (psoriasis)
  • Pain in the thighs, ribs, and shoulders
  • Heel or arch pain
  • Vision issues
  • Loss of appetite
  • Difficulty breathing, if AS had progressed to the ribs
  • Forward curvature of the spine, due to fused vertebrae (ankylosis)

Many of these symptoms can be caused by other conditions. A doctor or spine specialist at NewYork-Presbyterian can help treat your symptoms and identify the underlying cause.

What Causes Ankylosing Spondylitis?

Causes

There is no known direct cause as to why some people develop ankylosing spondylitis. But a large percentage of AS patients have a gene called HLA-B27, which has been linked to the condition.

But only some people with the HLA-B27 gene develop ankylosing spondylitis. In fact, the majority of kids who inherit the gene from a parent with AS don’t develop the condition. There are many other genes that may cause the disease.

Risk Factors

Risk Factors

Anyone can get ankylosing spondylitis. But risk factors and underlying conditions can elevate your chances of developing the condition.

Risk factors of AS include:

  • Age. The majority of people who develop AS are between the ages of 17 and 35.
  • Being male. The disease typically affects more young men than women.
  • Family history. You are more likely to have AS if one of your parents had the condition.
  • Certain health conditions. Having psoriasis, ulcerative colitis, or Crohn’s disease can raise your risk of AS.

Complications

Complications

There are complications that may arise as a result of ankylosing spondylitis, including:

  • Compression fractures, small cracks or breaks in the vertebrae.
  • Photophobia, a sensitivity to light due to potential eye inflammation.
  • Heart issues, including arrhythmia and cardiomyopathy.
  • Osteoporosis.
  • Cauda equina syndrome. Scarring and inflammation in the lumbar spine can cause nerve compression, resulting in urinary incontinence and other bladder and bowel issues.
 

This content has been reviewed by the following medical editors.

Evan Johnson, PT

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Trust NewYork-Presbyterian for Ankylosing Spondylitis Care

NewYork-Presbyterian is home to some of the nation’s top specialists in spinal care. Our doctors are well-versed in diagnosing the symptoms of ankylosing spondylitis. They will work with you to develop a treatment plan to help ease pain and prevent future complications.

To find out how to get relief from ankylosing spondylitis symptoms, reach out to NewYork-Presbyterian for an appointment.