Ankylosing spondylarthritis

Overview

Ankylosing spondylitis is an inflammatory disease that can cause some of the vertebrae in your spine to fuse together. This fusing makes the spine less flexible and can result in a hunched-forward posture. A severe case of ankylosing spondylitis can make it impossible for you to lift your head high enough to see forward.

Ankylosing spondylitis affects men more often than women. Signs and symptoms of ankylosing spondylitis typically begin in early adulthood. Inflammation also can occur in other parts of your body — such as your eyes and bowels.

Symptoms

Early signs and symptoms of ankylosing spondylitis may include pain and stiffness in your lower back and hips, especially in the morning and after periods of inactivity.

These symptoms may come on so gradually that you don't notice them at first. Over time, symptoms may worsen, improve or stop completely at irregular intervals.

The areas most commonly affected are:

  • The joint between the base of your spine and your pelvis
  • The vertebrae in your lower back
  • The places where your tendons and ligaments attach to bones, mainly in your spine, but sometimes along the back of your heel
  • The cartilage between your breastbone and ribs
  • Your hip and shoulder joints

 

Causes

Ankylosing spondylitis has no known specific cause, though genetic factors seem to be involved. In particular, people who have a gene called HLA-B27 are at significantly increased risk of developing ankylosing spondylitis.

As ankylosing spondylitis worsens and the inflammation persists, new bone forms as part of the body's attempt to heal. This new bone gradually bridges the gap between vertebrae and eventually fuses sections of vertebrae together. Those parts of your spine become stiff and inflexible. Fusion can also stiffen your rib cage, restricting your lung capacity and function.

Prevention

Because genetic factors appear to play a part in ankylosing spondylitis, it's not possible to prevent the disease. However, being aware of any personal risk factors for the disease can help in early detection and treatment. Proper and early treatment can relieve joint pain and may help to prevent or delay the onset of physical deformities.

Diagnosis

Diagnosis of ankylosing spondylitis may be delayed if your symptoms are mild or if you mistakenly attribute some of your symptoms to more common back problems.

Imaging tests

  • X-rays. X-rays allow your doctor to check for changes in your joints and bones, though the characteristic effects of ankylosing spondylitis may not be evident early in the disease.
  • Computerized tomography (CT). CT scans combine X-ray views taken from many different angles into a cross-sectional image of internal structures. CT scans provide more detail, and more radiation exposure, than do plain X-rays.
  • Magnetic resonance imaging (MRI). Using radio waves and a strong magnetic field, MRI scans are better at visualizing soft tissues such as cartilage.

Lab tests

There are no specific lab tests to identify ankylosing spondylitis. Certain blood tests can check for signs of inflammation, but inflammation can be caused by many different health problems. Your blood can be tested for the HLA-B27 gene, but most people who have that gene don't have ankylosing spondylitis.

Prognosis

AS can range from mild to progressively debilitating and from medically controlled to refractive. Some have times of active inflammation followed by times of remission, while others never have times of remission and have acute inflammation and pain.

Unattended cases of AS accompanied by dactylitis or enthesitis, especially when spine inflammation is not yet active, may result in a misdiagnosis of normal rheumatism. In a long-term undiagnosed period, osteopenia or osteoporosis of the AP spine may occur, causing eventual compression fractures and a back "hump". Typical signs of progressed AS are the visible formation of syndesmophytes on X-rays and abnormal bone outgrowths similar to osteophytes affecting the spine. The fusion of the vertebrae paresthesia is a complication due to the inflammation of the tissue surrounding nerves.

Organs commonly affected by AS, other than the axial spine and other joints, are the heart, lungs, eyes, colon, and kidneys. Other complications are aortic regurgitation, Achilles tendinitis, AV node block and amyloidosis. Owing to lung fibrosis, chest X-rays may show apical fibrosis, while pulmonary function testing may reveal a restrictive lung defect. Very rare complications involve neurologic conditions such as the cauda equina syndrome.

Treatment

The goal of treatment is to relieve your pain and stiffness, and prevent or delay complications and spinal deformity. Ankylosing spondylitis treatment is most successful before the disease causes irreversible damage to your joints.

Medications

Nonsteroidal anti-inflammatory drugs (NSAIDs) — such as naproxen (Aleve, Naprosyn) and indomethacin (Indocin) — are the medications doctors most commonly use to treat ankylosing spondylitis. They can relieve your inflammation, pain and stiffness. However, these medications also can cause gastrointestinal bleeding.

If NSAIDs aren't helpful, your doctor may suggest tumor necrosis factor (TNF) blockers. TNF is a cell protein that acts as an inflammatory agent in rheumatoid arthritis. TNF blockers target this protein to help reduce pain, stiffness, and tender or swollen joints. They are administered by injecting the medication under the skin or through an intravenous line.

Examples of TNF blockers include:

  • Adalimumab (Humira)
  • Etanercept (Enbrel)
  • Infliximab (Remicade)
  • Golimumab (Simponi)

TNF blockers can reactivate latent tuberculosis and may cause certain neurological problems.

Therapy

Physical therapy can provide a number of benefits, from pain relief to improved physical strength and flexibility. Your doctor may recommend that you meet with a physical therapist to provide you with specific exercises designed for your needs.

Range-of-motion and stretching exercises can help maintain flexibility in your joints and preserve good posture. In addition, specific breathing exercises can help to sustain and enhance your lung capacity.

As your condition worsens, your upper body may begin to stoop forward. Proper sleep and walking positions and abdominal and back exercises can help maintain your upright posture. Even if portions of your spine eventually fuse, you'll be able to get around and perform daily functions more easily if your spine fuses in an upright position.

Surgery

Most people with ankylosing spondylitis don't need surgery. However, your doctor may recommend surgery if you have severe pain or joint damage, or if a hip joint is so damaged that it needs to be replaced.

Resources

See your doctor if you have chronic pain and stiffness in your lower back and hips, or if deep breathing makes your chest hurt. Seek immediate medical advice if you develop eye pain, light sensitivity or blurred vision