Ankylosing spondylitis (AS) is a form of arthritis that’s associated with long-term inflammation of the spinal joints, also called vertebrae. The condition can cause back pain, hip pain, and stiffness. It can also affect a person’s mobility.

Your spine is designed to protect the vulnerable nerves of your spinal cord. Like interlocking puzzle pieces, the bones of the vertebral column fit together perfectly. This allows for flexibility without compromising spinal cord protection.

As normal aging progresses, the tissue of the cushioning intervertebral discs develops small tears and cracks. At the same time, the inner gel-like core of the vertebra, called the nucleus pulposus, gradually loses water and the ability to absorb shocks efficiently. Eventually, the outer ring of the vertebra, called the annulus fibrosus, weakens and tears. The bulging disc can press on nerves and cause pain.

AS mostly affects the spine and sacroiliac joints (SI). There are two SI joints on either side of the spine in your pelvis.

It’s unclear what causes the inflammation that results in stiff vertebrae. However, genetic factors are thought to play a role. As the inflamed vertebrae produce extra bone, they eventually fuse together. This fusion encases the shock-absorbing spinal discs and severely limits the flexibility of the spine. When the vertebrae become fused, it’s sometimes called “bamboo spine.”

In this comparison, the vertebrae of the lower spine have fused together. This makes it difficult for to bend backward and forward.

People with AS may awaken very stiff and find it difficult to sit or stand for extended periods of time. Doctors may prescribe physical therapy and exercise, especially swimming. Some believe that physical activity that promotes range of motion may prolong flexibility. When fusion of the spine occurs, maintaining good posture may help to avoid extreme stooping.

Although there’s no current cure for AS, excellent therapies are available to reduce inflammation, lessen pain, and slow disease progression. Treatments range from over-the-counter anti-inflammatory drugs like ibuprofen (Advil) or prescription doses of NSAIDs to newer biologic therapies such as:

  • etanercept (Enbrel)
  • infliximab
  • golimumab
    (Simponi Aria)
  • adalimumab (Humira)
  • certolizumab
  • secukinumab (Cosentyx)