In a previous article, we mentioned artificial disc replacement as an alternative to spinal fusion—with the caveat that it isn’t ideal for most patients.
That leaves things a little unclear, which isn’t surprising for a procedure that goes by multiple names, including artificial disc replacement, spinal disc replacement, total disc replacement, and even occasionally lumbar (lower back) disc replacement. Confused yet? Let’s dig deeper into what artificial disc replacement surgery actually entails and the results we’ve seen in patients since it was first performed in the U.S. more than 15 years ago.
How Your Back Works
Our back pain dictionary defines the spine as a series of stacked vertebrae or vertebral bodies, each containing a disc and two facet joints, connected by ligaments and muscles and mechanically involved in your every movement. The disc and the facet joints work together as a unit, similar to the ball and socket of your hip. Every move you make depends on the seamless functioning of a series of these units. A problem anywhere along the line will eventually lead to back pain.
An important feature of your back is its natural curve. If you look at someone (or yourself in a mirror) from the side, you’ll notice a curve shaped like an “S” in the back—there’s a curve at the top of the neck, the opposite curve midback, and another curve in the lower back, like the one at the top of the neck. Each time you change position throughout the course of a day—from standing to sitting and back again—so does the curve of your spine. A seated position, for example, lessens the curve in your lower back. These changes are a natural part of movement and help keep us balanced in every position.
Artificial Disc Replacement Surgery
In artificial disc replacement surgery, a surgeon replaces a degenerated or worn disc in the spine with a new, artificial one. The facet joints are left alone, and only the disc itself is replaced. (That’s why the term “total disc replacement” isn’t entirely accurate—you’re actually only replacing a portion of the motion unit, not the whole thing.) Patients with healthy facet joints will continue to retain a natural range of movement for several years after surgery (unlike spinal fusion, which “locks” you into a single position).
What are the shortcomings of artificial disc replacement surgery?
Although it sounds like this procedure would be effective in relieving back pain (and it is, to some degree), it isn’t a perfect solution. Here’s why:
- It only works for a very small percentage of people. You’re not a good candidate for this surgery if you have arthritis of the spine. In fact, only about 2%-5% of patients would benefit from it at all.
- It only replaces a portion of the functional spinal unit (the disc)—which is only fixing half of the problem. It’s much like fixing only one side of the joint in a bad arthritic hip; such a procedure would do little to give you relief. That isn’t ideal because your facet joints will naturally degenerate over time, possibly even becoming arthritic and painful. So while you may experience several years of relief as a result of the surgery, sooner or later, you’re likely to incur pain once again.
Looking for a solution that addresses back pain in a different way? Find out about an innovative total joint replacement procedure called BalancedBack®.
- It doesn’t address the most common cause of pain: pinched nerves. Nerves become pinched in the lower back for a variety of reasons, such as a ruptured disc, bone spurs, or thickened ligaments. For a surgery to be successful, then, it would need to unpinch the nerves, something that artificial disc replacement surgery does not do. In reality, the procedure only works for the small percentage of people who have back pain due to something other than pinched nerves.
- It uses an anterior approach—through the stomach—which is riskier than a posterior approach (through the back). To reach the spine, a disc replacement surgeon must navigate major blood vessels in the stomach area, making the surgery itself somewhat risky. This approach presents an even greater challenge should a patient need revision surgery later to address a worn-out disc or arthritic facet joints. The second time around, those same blood vessels are scarred and less movable as a result of the first surgery, which increases the likelihood of injuring them. (Studies show there’s a 10% chance of injury to the vessels, which can literally be life-threatening.) Anterior surgery also carries the risk of retrograde ejaculation in men, a type of sexual disfunction caused by cutting through small nerves in the stomach to access the spine.
Potential Problems Related To Artificial Disc Replacement Surgery
While the surgery may, in some cases, be successful at the outset, artificial disc replacement surgery has shown disappointing results over the long term.
In many patients, the facet joints become arthritic and stiff over time, which is in contrast to the new artificial disc received during surgery. So while the disc itself may be in good condition, the weakened joints will cause pain and reduced range of motion, to six or seven degrees instead of the normal 12, for example. Ultimately this loss of natural movement creates more stress in other segments of your spine and will result in more back pain over time.
In fact, arthritic facet joints have often driven patients to undergo additional surgery anywhere from 10-15 years after the original disc replacement procedure. At that point, fusion was the only solution to address painful joints.
While fusing the joint relieves pain to a degree, it also stops motion, interfering with your natural S-shaped curve. If a surgeon fuses a person in a certain position (for example, standing), then sitting will prove difficult, because the spine is locked in a standing position. This inability to move naturally causes enormous stress directly above the fused location, and the spine breaks down again. Forty percent of fusion patients need surgery again within 15 years.
A Better Alternative
Up until now, people with debilitating lower back pain had no choice but to try artificial disc replacement surgery and/or fusion and hope that these procedures would work. Even if they did work initially, the pain would only be relieved in part and usually only for a limited period of time.
Today, there’s a better alternative: total joint replacement. Called BalancedBack®, this innovative form of artificial disc replacement has one important difference—it replaces the facet joints as well as the disc. Because it replaces the whole joint, your spine regains its natural range of movement and retains its natural “S” curve, allowing you to find comfort in any position.
Here is a short clip of Corey, a BalancedBack® patient, discussing life after his procedure:
BalancedBack® isn’t right for everyone, but it is an exciting treatment option for many patients. Interested in finding out if it’s a good fit for you? Schedule a complimentary call with our clinical coordinator to learn more.