Ankylosing spondylitis is a type of arthritis that affects the spine. Ankylosing spondylitis symptoms include pain and stiffness from the neck down to the lower back. The spine’s bones (vertebrae) may grow or fuse together, resulting in a rigid spine. These changes may be mild or severe and may lead to a stooped-over posture. Early diagnosis and treatment helps control pain and stiffness and may reduce or prevent significant deformity.
Symptoms appear gradually, usually around 23 years of age. Initial symptoms are typically chronic pain and stiffness in the middle part of the spine or the entire spine, often with pain referred to one or the other buttock or the back of the thigh from the sacroiliac joint. Since the initial signs and symptoms are not specific for ankylosing spondylitis, there is a lag-time between onset of disease and diagnosis, which averages between 8.5 years and 11.4 years. When the condition presents before the age of 18, it is relatively likely to cause pain and swelling of large limb joints, particularly the knee. In prepubescent cases, pain and swelling may also manifest in the ankles and feet, where calcaneal spurs may also develop. Pain is often severe at rest, but improves with physical activity. However, many experience inflammation and pain to varying degrees regardless of rest and movement. Ankylosing spondylitis is one of a cluster of conditions known as seronegative spondyloarthropathies, in which rheumatoid factor tests are negative and the characteristic pathological lesion is an inflammation of the enthesis (the insertion of tensile connective tissue into bone).
There is no direct test to diagnose AS. A clinical examination, magnetic resonance imaging (MRI), and X-ray studies of the spine, which show characteristic spinal changes and sacroiliitis, combined with a genetic marker blood test are the major diagnostic tools. A drawback of X-ray diagnosis is the signs and symptoms of AS have usually been established as long as 8–10 years prior to X-ray-evident changes occurring on a plain film X-ray, which means a delay of as long as 10 years before adequate therapies can be introduced. Options for earlier diagnosis are tomography and MRI of the sacroiliac joints, but the reliability of these tests is still unclear. The Schober’s test is a useful clinical measure of flexion of the lumbar spine performed during examination.
Medical professionals and experts in AS have speculated that maintaining good posture can reduce the likelihood of a fused or curved spine which occurs in a significant percentage of diagnosed persons.
The major types of medications used to treat ankylosing spondylitis are pain-relievers and drugs aimed at stopping or slowing the progression of the disease. Pain-relieving drugs come in two major classes:
- Anti-inflammatory drugs, which include NSAIDs such as ibuprofen, phenylbutazone, diclofenac, indomethacin, naproxen and COX-2 inhibitors, which reduce inflammation and pain. 2012 research showed that patients with elevated acute phase reactants seem to benefit most from continuous treatment with NSAIDs.
- Opioid analgesics
Drugs used to treat the progression of the disease include:
- Disease-modifying antirheumatic drugs (DMARDs) such as cyclosporin, methotrexate, sulfasalazine, and corticosteroids, are used to reduce the immune system response through immunosuppression
- Tumor necrosis factor-alpha (TNFα) blockers (antagonists), such as the biologics etanercept, infliximab, golimumab and adalimumab, have shown good short-term effectiveness and trials are ongoing to determine their long-term effectiveness and safety. One drawback is the cost.
- Anti-interleukin-6 inhibitors such as Tocilizumab, currently approved for the treatment of rheumatoid arthritis, and rituximab, a monoclonal antibody against CD20, are also undergoing trials.
In severe cases of AS, surgery can be an option in the form of joint replacements, particularly in the knees and hips. Surgical correction is also possible for those with severe flexion deformities (severe downward curvature) of the spine, particularly in the neck, although this procedure is considered very risky.
In addition, AS can have some manifestations which make anaesthesia more complex. Changes in the upper airway can lead to difficulties in intubating the airway, spinal and epidural anaesthesia may be difficult owing to calcification of ligaments, and a small number of patients have aortic insufficiency. The stiffness of the thoracic ribs results in ventilation being mainly diaphragm-driven, so there may also be a decrease in pulmonary function.
Some of the therapies that have been shown to benefit AS patients include:
- Exercise programs, either at home or supervised, are better than not having an exercise program;
- Group exercises are better than home exercises;
- Extending regular group exercises with few weeks exercising at a spa resort is better than group exercises alone.
- Moderate-to-high impact exercises like jogging are generally not recommended or recommended with restrictions due to the jarring of affected vertebrae that can worsen pain and stiffness in some patients.