Ankylosing Spondylitis
About Ankylosing Spondylitis
AS is a chronic, systemic, inflammatory disease of the joints and ligaments of the spine. Other joints may be involved. This typically results in pain and stiffness in the spine. The disease may be mild to severe. The bones of the spine may fuse (ankylosis) causing a rigid spine. Early diagnosis and treatment may help control the symptoms and reduce deformity.
Causes of Ankylosing Spondylitis
The cause of AS is unknown although there appears to be some genetic component. AS is associated with the HLA B27 gene but it is unclear why. The gene is seen in about 8% of normal Caucasians, about 10% of AS patients don't have the gene and only about 10% of people with the gene will get AS.
Diagnosing Ankylosing Spondylitis
The diagnosis is typically suspected by the doctor based on the signs and symptoms. The doctor will take a thorough history and do a physical examination. X-rays, especially those of the sacroiliac joints can be confirmatory. The HLA B27 gene may be checked by a blood test, but its presence or absence does not ultimately confirm or reject the diagnosis.
The signs of AS are as follows. Early on, there is pain and stiffness in the buttocks and low back due to sacroiliac joint involvement. Over time, the symptoms can progress up the spine to involve the chest and neck. Ultimately, the bones may fuse together causing limited range of motion of the spine and limiting one's mobility. Shoulders, hips and sometimes other joints may be involved. AS may affect tendons and ligaments. The heel may be involved with Achilles tendonitis and plantar fasciitis. Since it is a systemic disease, patients can get fever and fatigue, eye or bowel inflammation, and rarely, there can be heart or lung involvement. AS is typically non life-threatening. Usually, it is a slowly progressive disease. Most people are able to work and function normally.
Treatment of Ankylosing Spondylitis
At this time there is no known curative treatment. Goals of treatment are to reduce pain and stiffness, slow progression of disease, prevent deformity, maintain posture and preserve function.
Exercise programs are an essential part of the treatment. Patients may be referred for a formal physical therapy program. Patients with AS are given daily exercises for stretching and strengthening, deep breathing exercises and posture exercises to avoid stooping and slumping. A hard mattress is recommended.
Medications are also used to treat AS. Non-steroidal anti-inflammatory drugs (NSAIDs) are traditionally used to control symptoms. Steroids, such as prednisone, are rarely used. Sometimes, medications that are normally used for rheumatoid arthritis, such as sulfasalazine or methotrexate, may be used. These medications have more toxicities and it is unclear if they actually slow the progression of the disease. More recently, the biologic agents etanercept (Enbrel), adalimumab (Humira), and infliximab (Remicade) have been approved for use in AS. These drugs may not only help symptoms but also slow the progression of the disease. They are only given as IV's in the doctor's office or by self-administered shots at home.
Surgical options are limited. There are no specific surgical interventions for the spine. Sometimes, in severe cases, replacement of the shoulder or hip joint is beneficial.