Ankylosis spondylitis (AS) is classified as a rheumatologic disorder of the spine. It is considered one of the so-called sero-negative arthropathies. This inflammation can eventually lead the joints to become fused, leading to stiffness and reduced range of motion (known as ankylosis). It also frequently affects the hips and other peripheral joints. Ankylosis comes from Latin words meaning "bent" or "crooked."
AS usually strikes a person between the teen years and the age of 40. The classic picture of AS is a man between the ages of 15 and 40 with intermittent, dull lower back pain, and stiffness slowly progressing over a period of months to years. Although AS was once considered to predominantly affect men, it is now known to affect women as well. There may also be differences in symptoms and outcomes in men and women with AS.1
The cause of AS is not known, but a genetic predisposition to the disorder does exist. People with AS often have stiffness in the morning that lasts a few minutes to several hours, sometimes coupled with fatigue. Prolonged inactivity can cause more pain and stiffness in the back, unlike other lower back disorders, which often improve with rest. With AS, there may be pain and stiffness in the shoulders, hips, or other joints as well. After a few years with the disorder, there may be pain in the middle or upper part of the back and gradual stiffening of the spine and eventually the neck. The classic deformity associated with AS is a rigid kyphosis, which causes a stiff, hunched forward posture.
Ankylosis spondylitis is often diagnosed after your doctor takes a thorough medical history, performs a physical examination, and orders appropriate x-rays and laboratory studies. There is a significant association of AS with a commonly performed blood test that detects the presence or absence of a particular marker in the blood called the human leukocyte antigen B27 (HLA-B27). A positive test, along with other clinical correlations, will help to establish the diagnosis of AS.
The goal of treatment for ankylosis spondylitis is to relieve your pain and stiffness, while preventing spinal deformities and other complications. Treatment will be most successful before AS causes irreversible damage to your joints. Non-steroidal anti-inflammatory agents (NSAIDS) may help relieve your inflammation, pain, and stiffness. If they aren’t helpful, your doctor may suggest tumor necrosis factor (TNF) blockers. These injections work differently from NSAIDS but also help to reduce inflammation, pain, and stiffness. Physical therapy can also help relieve pain while improving strength and flexibility.
Most people with facet arthropathy will complain of lower back pain that becomes worse when twisting, standing, or bending backward. Usually, the pain is confined to a particular point in the spine, and unlike the pain and numbness often caused by a slipped disc or sciatica, it doesn’t usually radiate into the buttocks or down the legs.
As the facet joints become arthritic, they often develop bone spurs—tiny outgrowths or projections of bone—that can decrease the amount of space available for the nerve roots as they exit the spinal canal. This can contribute to the development of spinal stenosis, another condition that may cause pain, numbness, and weakness in the buttocks and legs.
In fact, people who have facet arthropathy often have other conditions that may be contributing to their symptoms. Aside from spinal stenosis, it’s possible that arthritis in other parts of your spine or degenerative disc disease—a natural part of the aging process where our intervertebral discs lose flexibility, elasticity, and shock absorbing characteristics—could be contributing to your symptoms.
To find out if facet arthropathy is causing your back pain, your doctor may order the following tests: A CT scan (CAT scan) or MRI, which shows evidence of facet joint degeneration, even in most people who only have mild to moderate pain. A bone scan shows areas of active inflammation in the spine.
Another way to help confirm a diagnosis is to have your painful facet joints injected with a mixture of local anesthetic and an anti-inflammatory steroid. If the injection relieves your back pain, it’s likely that facet arthropathy is contributing to your symptoms.
There are several options for treating the pain and symptoms caused by facet arthropathy:
Osteoarthritis is the most common form of arthritis, affecting millions of people around the world. It’s sometimes known as “wear and tear” arthritis as it worsens with time and age. Osteoarthritis can affect any joint in your body, including the spine.
The symptoms of osteoarthritis usually come on slowly and become worse as time passes.
The signs and symptoms may include:
There are several factors that contribute to the likelihood of a person developing osteoarthritis.
These factors may include:
Your doctor will perform a complete medical exam and may also use x-rays to confirm the diagnosis and make sure you don’t have another type of arthritis. An MRI may also be necessary to get a more detailed look at the spine and the surrounding tissues if the x-ray does not clearly point to a diagnosis.
Osteoarthritis is usually first treated by a combination of non-surgical treatments including physical therapy, exercise, and medications. Surgery may be helpful to relieve pain when other treatment options are not effective, especially in the case of vertebral compression fractures.
Sacroiliac dysfunction is a common cause of back pain. In most instances, the discomfort that comes with it can be managed through conservative treatment; however, some cases may require back surgery.
The sacroiliac joint is located in the lower back between the spine and hip joint, and normally does not move much. Inflammatory arthritis (such as ankylosis spondylitis), degeneration of the sacroiliac joint, or misalignment of this joint can cause pain associated with sacroiliac dysfunction.
Sacroiliac joint pain is usually located in the buttock, just to the side of the midline. It is usually one-sided, but not always. The pain may radiate down the back of the thigh to the knee. Typically, it is difficult to find a comfortable position when lying in bed. Sacroiliac joint pain can become severe and disabling if not treated.
Some common causes of sacroiliac joint pain are muscle tightness, pregnancy, types of arthritis, and the wearing away of the cartilage between the bones. Although sacroiliac joint pain can be caused by trauma, it usually develops over a long period of time.2
Accurately diagnosing sacroiliac joint dysfunction can be difficult and must be done by clinical exam. Its symptoms can mimic those of other common conditions, such as herniated disc and radiculopathy (pain along the sciatic nerve that radiates down the leg). Unless your doctor specifically checks for sacroiliac dysfunction, your physical examination may turn out "normal" and you may be told that nothing is wrong with you.
During the exam, your doctor may try to determine if the sacroiliac joint is the cause of pain by moving the joint known as “provocative maneuvers.” If the movement recreates your pain, and no other cause of pain has been found (such as a herniated disc on an MRI scan), the sacroiliac joint may be the cause of the pain.
A sacroiliac joint injection is another diagnostic tool that may be used. In this test, your physician uses fluoroscopic guidance (live x-ray) and inserts a needle into the sacroiliac joint to inject lidocaine (a numbing solution). If the injection relieves your pain, it can be inferred that the sacroiliac joint is the source of the pain.
Sometimes sacroiliac dysfunction is associated with piriformis syndrome. The piriformis is a small muscle in the buttock that stabilizes the sacroiliac joint. When irritated, it causes pain in the buttock. The piriformis muscle happens to overlap the sciatic nerve and can also cause sciatic pain down the leg all the way to the foot. This is often mistaken for sciatica, which is caused by a pinched nerve root in the spine.
If diagnosed early, the majority of people with sacroiliac dysfunction and/or piriformis syndrome will improve with non-surgical treatment.
For those who do not respond to conservative measures, fusion of the sacroiliac joint may be the next step. Read more about sacroiliac joint fusion.
Information on this site should not be used as a substitute for talking with your doctor. Always talk with your doctor about diagnosis and treatment information.
Lee, et al. Women with Ankylosing Spondylitis: A Review. Arthritis & Rheumatism, Vol 59, 449-454, 2008