Ankylosing Spondylitis
Ankylosing spondylitis is a rare condition affecting less than 1% of the population. The term “ankylosing” means “stiff” or rigid” in Greek. “Spondyl” means “spine” and “itis” means inflammation. Therefore, “ankylosing spondylitis” is Greek for stiff, inflamed, spine. It is a type of arthritis (a condition that causes pain and swelling in joints) that mainly affects the spine. Patients with ankylosing spondylitis typically experience pain and stiffness in their spine due to the constant inflammation and swelling that the body is not able to control. As the condition progresses the vertebrae of the spine may actually fuse together (Figure 1). This condition may also affect other body parts, including the hips, shoulders, and knees. Ankylosing spondylitis typically affects young adults, and people with the HLA-B27 gene. It is twice as common in men. Currently, there is not a single test that definitively diagnoses ankylosing spondylitis. Performing a blood test to check for HLA-B27, markers of inflammation, and elevated blood counts may help establish the diagnose. There is currently no cure for this condition. However, there are ways to manage it using medications, physical therapy, lifestyle changes and surgery.
Symptoms of Ankylosing Spondylitis
The symptoms of ankylosing spondylitis include back pain and stiffness, commonly in the spine and hip, mostly in the morning or after periods of sitting still. Ankylosing Spondylitis may also cause pain in areas other than the spine, including the neck, shoulder, ribs, knees, and possibly heels. Patients may experience a decrease in flexibility of the spine and fatigue. Some patients may experience eye conditions called iritis or uveitis, which are described as soreness, redness, and swelling inside the eye. This may lead to sensitivity to light and blurry vision.
Physical Exam Findings in Ankylosing Spondylitis
On a physical exam, patients will often display limited flexibility and movement of the spine, hips, knees, and shoulders. When the physician palpates where the lower spine connects with the pelvis (sacroiliac joint), there may be pain and tenderness. Ankylosing spondylitis may also change a patient’s posture causing them to lean forward with a more rounded spine.
Imaging Studies
X-rays are a tool that may be used to help diagnose ankylosing spondylitis. In ankylosing spondylitis there may be the presence of a” bamboo spine” sign. This occurs when the bones that make up the spine fuse together which will make the bone straight and stiff resembling a bamboo.
MRI is another tool that may be used to help diagnose ankylosing spondylitis in the earlier course of the disease because it allows the physicians to see the details of cartilage, ligaments, and soft tissues. A CT scan is another option when X-ray and MRI do not provide a clear answer.
Treatment of Ankylosing Spondylitis
Conservative Treatment
Although there is no cure for ankylosing spondylitis, this condition can be managed through medication, physical therapy and lifestyle changes. Common conservative treatments include activity modification, physical therapy, medications to reduce pain, and possibly one or more corticosteroid injections. Activity modification, such as reducing or eliminating activities that cause increased pain and opting for low-impact activities such as swimming, can be very beneficial in decreasing pain symptoms. A physical therapy program with exercises designed to increase back flexibility and improve core strength can be useful. Anti-inflammatory and other medications that reduce pain may be helpful for some patients. Additional types of medications that can be beneficial include janus kinase inhibitors, biologics, and corticosteroids. Lifestyle changes may also alleviate some symptoms, including not smoking and maintaining a balanced diet.
Surgical Treatment
Surgery may be indicated if there is severe joint damage, nerve abnormalities, or spine deformities. Ankylosing spondylitis may result in severe joint damage. For some affected joints like the hips a joint replacement may be performed to improve pain and increase motion. Due to the fusion of the spinal bones there may be compression of the spinal nerves that can lead to pain, numbness, and loss of function, requiring surgery to correct.
Edited November 12th, 2024 by Nadia Hackett and Stephen Pinney MD