Surgery for Ankylosing Spondylitis

Most people with ankylosing spondylitis (AS) can successfully manage their disease with a combination of medications and physical therapy. However, some people may experience disease progression or complications despite these treatments. While most people with AS don’t need surgery, in certain cases surgery may be necessary.¹

How ankylosing spondylitis affects the joints

AS most often affects the spine and the sacroiliac joints, although some people with AS have joints in their arms or legs affected as well, called peripheral AS. AS causes chronic inflammation in the joints and in the points where tendons and ligaments attach to the joints, called entheses. This chronic inflammation wears away at the bone of the joints. As the body works to replace the lost bone, it can create excess bone, leading to a fusing of the joint (ankylosis). The entheses and ligaments may also become calcified, called syndesmophytes. The fused joints in the spine can take on the appearance of bamboo and is called “bamboo spine” because of its appearance on x-rays. The fused spinal joints make the spine less stable and more likely to fracture.^2-4 AS may also cause complications like kyphosis, an outward curvature of the spine that causes a hunched back, or spinal stenosis, a narrowing of the spinal column which can put pressure on the nerves, affecting sensation or movement.^5-7

When the hips are affected by AS, which occurs in approximately 30% of people, the damage is different. Instead of the formation of new bone, AS in the hips wears away or erodes the hip joint, which destroys the joint. This can be disabling and painful, causing a significant reduction in the individual’s mobility and quality of life. Hip replacement can lead to a dramatic improvement in function and mobility.^8,9

Types of surgery used in people with ankylosing spondylitis

There are several different surgical procedures that may be used in people with ankylosing spondylitis, including^1,10:

• Osteotomy – used to correct a deformity in the spine
• Spinal fusion instrumentation – used to stabilize a weakened spine
• Spinal decompression – used to relieve pressure on the nerves
• Hip replacement – used to restore function and reduce pain in the hip joint

Getting an assessment for surgery

Surgery may be performed by an orthopedic surgeon (for a hip replacement) or a neurological surgeon or spinal surgeon (for spinal surgeries). Prior to surgery, the doctor will evaluate the patient with a thorough work-up, including a medical history, physical examination, x-rays, and possibly, other tests like an MRI (magnetic resonance imaging). The surgeon will assess the functional limitations as well as ask questions about how AS is impacting the patient’s daily living.¹⁰

Preparing for surgery

If surgery is recommended, patients can prepare by asking their surgeon all their questions, including what to expect during recovery. Ask about anesthesia and other pain medications, and when normal activities can be resumed. It’s important that doctors know all the medications and health conditions of their patient, as well as any previous reactions to anesthesia.¹¹ Patients should also discuss any planned surgeries with their rheumatologist, as they may need to stop some medications such as biologics prior to surgery.