What to Know About Surgery for Ankylosing Spondylitis

If you have ankylosing spondylitis (AS), a type of inflammatory arthritis that can affect the spine, we’ve got good news: Most people never need surgery. Still, it never hurts to be prepared and know what you might be in for if your rheumatologist or spine specialist thinks you’d benefit from surgical intervention.

There are a few basic indications when surgery may be considered or recommended, and based on your symptoms and disease severity, there are several procedures that may benefit you. Here’s how you can tell you might need surgery, and what to expect before and after.

When to Consider Surgery for Ankylosing Spondylitis

Most people with AS will never need surgery, but those who do may be a candidate for one or more procedures. What’s more likely? Surgery to repair complications of the condition. AS has the potential to turn minor accidents and trauma into something more serious, says Baron S. Lonner, M.D., so even if you don’t need surgery to correct AS-related deformities, you still might need it to treat AS-related fractures.

People with AS “are prone to fracture of the rigid spinal column even with relatively trivial trauma, such as a fall or a low-speed motor vehicle accident. This can result in severe instability, spinal deformity, and most importantly, deteriorating neurological function or paralysis,” says Dr. Lonner, a professor of orthopedic surgeon at Mount Sinai Hospital in New York City. Some estimates put the number of people with AS who experience fractures between 4% and 18%.

Any of the criteria below might warrant surgery, either alone or in combination with each other.

Chin-on-Chest Deformity

The magnitude (angle) of this deformity is the most important consideration for whether surgery is recommended. An example is forward flexion so great that the chin rests near or on the chest (commonly called chin-on-chest deformity). The functional limitations of this particular deformity are serious: You might be unable to look forward, make visual contact, drive, and may even have difficulty eating.

“Once a deformity has been established, it is quite rigid or stiff and typically is not correctible” by exercise, stretching, and bracing, says Dr. Lonner. People with this sort of deformity tend “to be pitched forward and often have difficulty looking straight ahead as the head is often fixed in a downward position.”

Spinal Instability

An unstable spine means that the joints aren't controlling the spine’s mobility as they should, allowing it to move too much. People with AS often develop spinal instability due to Andersson lesions—inflammatory damage to intervertebral discs—or vertebral fractures. Spinal instability can put you more at risk for nerve damage.

Neurologic Symptoms

"Neurologic deficit" refers to altered function of the body due to injury to the brain, spinal cord, muscles or nerves. These changes in function may be sensory changes (such as pain or tingling sensations) and/or motor-related (walking problems or muscle weakness). Data from more than 100 people in a 2018 study published in Clinical Rheumatology suggests that up to a third of people with AS may have neurological symptoms.

Neurological symptoms can include:

• Pain radiating down the path of the nerve and into a limb (called radiculopathy; sciatica is an infamous example)

• Numbness or tingling in limbs or extremities

• Muscle weakness in a limb

• Bladder or bowel incontinence (this could indicate cauda equina syndrome, which is an emergency and could result in paralysis if untreated)

Types of Spine Surgery for AS

If you have any of the above complications from ankylosing spondylitis, your doctor may talk with you about considering surgery. “The goal of surgery is to realign and stabilize the spine in a manner that affords the patient the best posture possible,” says Ali A. Baaj, M.D., a neurosurgeon and chief of spine surgery at Banner Health in Phoenix, AZ.

The type of spine surgery your surgeon recommends is based on many factors, including your symptoms, the severity of the spinal deformity (such as chin-on-chest), rigidity of the spine, your age, lifestyle (for instance, tobacco use can interfere with fusion healing), and overall health.

Sometimes the surgery involves one or more procedures. These are a few of the options you and your doctor may consider:

Laminectomy

Other procedures, such as laminectomies, decompress the spinal canal and associated nerves, restoring or preventing neurologic dysfunction. “Decompress” means to take pressure off the spinal cord or nerves, so if you’re having neurological symptoms, a decompression surgery may help.

In a laminectomy, the surgeon will remove part of your vertebra (backbone) to relieve pressure on a nerve. A microdiscectomy will clear out any pieces of damaged intervertebral disc that might be compressing a nerve root. This one- to two-hour procedure is the most common surgery for ankylosing spondylitis, per Weill Cornell Medicine.

Spinal Instrumentation and Fusion

These are surgical procedures used to correct spinal deformity and to provide permanent stability to the spinal column. These procedures join and solidify the level where a spinal element has been damaged or removed. Instrumentation uses medically designed hardware such as rods, bars, wires, and screws. These devices hold the spine straight during fusion. Fusion is the adhesive process joining bony spinal elements.

AS can cause some of your vertebrae (or the bones of your SI joint) to fuse on their own, which can throw off your body mechanics and make other vertebrae pick up the slack. These, in turn, get stressed and may become damaged.

Osteotomy

During an osteotomy, bone is cut to correct angular deformities. The bone ends are realigned and allowed to heal. Spinal instrumentation and fusion may be combined with an osteotomy to stabilize the spine during healing. If you have a chin-to-chest deformity, an osteotomy “may be required to restore a more horizontal gaze and comfortable alignment,” says Dr. Lonner. One study of nearly 300 osteotomy procedures found that study subjects’ disability metrics decreased by about 50%.

Pre-Surgery Evaluation

If surgery is in the cards for you, the next step will be a pre-surgery evaluation. Dr. Baaj says that pre-surgery evaluation and planning take into account the diagnosis, as well as the locations affected and the severity of your AS symptoms. Surgeons will use full-length X-rays to evaluate your spine’s alignment, and they’ll take measurements of the curve of any chin-to-chest deformities.

“Furthermore, pre-operative images can be utilized to determine patient positioning on the operating table, incisions, osteotomies, and type of placement of spinal instrumentation,” says Dr. Baaj. “Pre-planning the entire surgical procedure is typical in these types of complex spine surgeries.”

Recovery from Surgery for Ankylosing Spondylitis

Immediately following surgery, you are moved from the operating room into the recovery area. There nurses and other medical professionals monitor your vital signs, including postoperative pain. Some types of spinal surgical procedures require you to wear a brace temporarily, which is explained to you before surgery.

Depending on the type of surgery, you may spend one or more nights in the hospital. During hospitalization, nurses will keep a close watch on you. type of surgery will also determine how fast you regain mobility: Some patients are up and walking with assistance the same day of surgery, but some are not.

“Regardless if a patient underwent surgery for fracture or deformity, the post-operative period can be challenging,” says Dr. Baaj. He says bracing for at least six to 12 weeks after surgery is normal, as well as X-rays every three to six months to check healing progress if you’ve had fusion surgery.

Bottom line? Surgery for ankylosing spondylitis isn’t common, and odds are good that you will be able to manage your symptoms through medication and lifestyle changes like diet alone. But if your AS continues to worsen, talk with your doctor about surgical options. Together, you’ll come up with an approach that’s right for you.