Ankylosing spondylitis (AS) is a form of arthritis that affects the spine’s vertebrae and joints (facet joints). AS can affect one or more regions of the spine: cervical (neck), mid back (thoracic), low back (lumbar), and/or sacral (sacrum, pelvis). The Center of Disease Control's National Health and Nutrition Examination Survey estimated that as many as 2.7 million adults in the United States may be affected by ankylosing spondylitis.

Ankylosis: joints fuse together and become unmovable

Spondylitis: inflammation involving the spine’s vertebrae and facet joints

Similar to other types of arthritis AS causes inflammation and pain. In severe cases of ankylosing spondylitis, the disease causes new bone formation, which can cause the bones in the spine to fuse (join) together. Involvement of the sacroiliac joints (SI joints) is classic as the disease progresses. When vertebrae or other bones/joints fuse together, the spine becomes stiff and immobile. Sometimes this can lead to significant changes in posture, such as kyphosis—an abnormal forward position of the upper spine resembling a hunched back.

The severity of AS can vary greatly from person to person. Some people experience intermittent back pain, and others have severe pain and stiffness for long periods of time. Almost all cases are characterized by acute pain followed by temporary remission when symptoms subside. In some cases, AS may affect other parts of the body, such as the eyes.

Exact Cause of Anklyosing Spondylitis


Although the exact cause of ankylosing spondylitis isn’t known, scientists know that genetics plays a role in the disease. Most people who have ankylosing spondylitis also produce the protein human leukocyte antigen B27 (HLA-B27). Therefore, the doctor may order the blood test that detects HLA-B27. This marker is found in more than 95% of Caucasians with AS. However, you do not have to have the HLA-B27 protein to have AS, and most people with this marker never get ankylosing spondylitis.

Treatments for ankylosing spondylitis may include:

Tumor Necrosis Factor (TNF) Blockers. Recent studies show the most promising medications to be tumor necrosis factor (TNF) blockers. These medications suppress the body’s response to TNF, a chemical that causes inflammation. Besides treating inflammation, a TNF blocker can help to slow the progression of ankylosing spondylitis. TNF blockers include: Infliximab , Etanercept , and Golimumab

Disease Modifying Antirheumatic Drugs (DMARDs).This class of drug is prescribed to help reduce inflammation and slow the progression of ankylosing spondylitis. A DMARD is a slow working medication, and must be consistently taken per the prescribing doctor’s directions. DMARDs prescribed to treat AS include methotrexate and sulfasalazine (Azulfidine).Pain Relievers. Nonsteroidal anti-inflammatory drugs (NSAIDs) are often the first-line medications recommended to treat pain associated with ankylosing spondylitis. Your doctor may recommend an over-the-counter NSAID or prescribe a stronger type.

Physical Therapy and Exercise

Physical therapy and exercise are very important for people with AS. Not only can gentle stretching and exercise (as tolerated) help relieve back and/or neck stiffness; it can help to you stay as flexible and mobile as possible. Your physical therapist can prescribe a home stretching/exercise program, as well as help you with good practices for proper posture. Furthermore, cold therapies can help reduce inflammation, and heat can help relieve joint stiffness.