Ankylosing Spondylitis and Spine Pain

An x-ray like image of an inflamed sacroiliac joint.
An x-ray like image of an inflamed sacroiliac joint. SCIEPRO / Science Photo Library / Getty Images

Ankylosing spondylitis (acronym AS)  is one disease found along a spectrum of inflammatory arthritis conditions that affect the spine and sacrum. The broader spectrum, known as axial spondyloarthritis, (but often written as "axial SpA",) includes diseases such as ankylosing spondylitis as subsets. 

These are diseases that affect your spine and structures that connect to it (the term "axial skeleton" actually refers to your trunk, skull, spine, pelvis and rib cage.) When spondyloarthritis affects the extremities, it's referred to as peripheral spondyloarthritis.


Ankylosing Spondylitis Defined

Ankylosing spondyloarthritis is a a rare but debilitating subset of axial spondyoarthritis in which the spine, over time, fuses. It is chronic, and progressive.  Your risk is much higher if you test positive for the HLA-B27 gene, although scientists are not exactly sure of the role HLA-B27 plays in the process.

What happens when you have AS?  It generally starts with sacroiliac (SI) joint inflammation and stiffening.  Because AS is a chronic condition, the symptoms over time progress to other areas of your axial skeleton - namely your hips, vertebrae, and rib cage.

Here's an anatomy refresher in case you need it: The SI joints, as they are sometimes called, are the joints between the sacrum and the pelvis. They are located on either side of the sacrum, which is the lowest section of the spinal column.)  

Ultimately, ankylosing spondylitis can result in a completely fused spine, and total loss of spinal mobility.


Symptoms of Ankylosing Spondylitis

AS symptoms include early morning joint/spine stiffness, and pain that is worse after rest, but feels better as the day goes on or after exercise.  Fatigue, feverish feelings and/or night sweats are also symptoms.  Note that AS symptoms tend to come on slowly, often taking weeks or months to make themselves known.

Diagnosing Ankylosing Spondylitis

Ankylosing spondylitis, as well as other subset diseases along the axial spondylitis spectrum sometimes show up on x-ray or MRI - but sometimes they do not.  Often when a subset disease is "non-radiographic,"  (which is what it's called when there's no evidence of it on diagnostic imaging films,) it's because the disease is still in an early stage.  This could mean that signs may show up on future films (a good reason to keep monitoring with your doctor.)

Radiographic signs are important because they help your doctor definitively diagnose ankylosing spondylitis.

Some people find getting their ankylosing spondylitis diagnosed is a challenging or even frustrating experience.  AS is often confused with rheumatoid arthritis, which means before arriving at a conclusion about what's causing your symptoms, your doctor will have to distinguish between the two diseases.

Just the same, getting a diagnosis is an important goal to work for - the sooner you do, the sooner you can start a treatment regimen that will hopefully be right for you.  Ankylosing spondylitis is generally treated with drugs (a number of new ones are now on the market) and exercise.  Exercise may help slow the disease progression, as well as manage pain and other symptoms.


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