Lumbar Disc Replacement

New treatment for low back pain

spine disc
Spinal discs are the cushions between the vertabrae.. Nancy Ross / Getty Images

A lumbar disc replacement is emerging as a new treatment option for some types of low back pain. Spinal disc replacement surgery has recently been FDA approved in the United States, and a growing amount of research is being performed throughout the world, mostly in Europe, on this new procedure. Lumbar disc replacement may soon be a standard treatment for some types of low back pain.

The Problem: Degenerative Disc Disease

Degenerative disc disease is one type of back pain that is caused by wearing away of the cushion that rests between the vertebrae of our spine.

The spinal column is made of stacked bones called vertebrae. These bones are separated by a cushion at each level called a spinal disc. The disc is a tough but pliable tissue that helps maintain the position of the spine, but also allows motion between the vertebrae. With this design, we have the stability to stand upright, but also the flexibility to bend and twist. Unfortunately, these discs can cause problems as they wear away.

As the disc ages, it becomes more brittle and less flexible. The disc also becomes more prone to injury and degradation. Exactly what causes pain with lumbar disc degeneration is debatable, but we do know that some patients with worn out discs have typical symptoms of low back pain.

It is important to understand that aging discs are normal! MRIs of patients with no symptoms of back pain often show wearing away of the discs. It should not be considered abnormal to have wearing of the spinal discs.

That said, some patients can develop symptoms of back pain, and it is possible that their symptoms come from the spinal disc degeneration. It is very important to have this carefully evaluated by your orthopedic surgeon before embarking on any treatment plan.

Current Treatment: Spine Fusion Surgery

Spine fusion has long been considered the best treatment for degenerative disc disease of the lumbar spine once conservative treatment measures have failed.

The first treatment for degenerative disc disease is always with nonsurgical options. These include anti-inflammatory medications, physical therapy, and epidural steroid injections. However, if patients try these treatments, and do not find satisfactory relief, then spine fusion surgery may be an option.

Spine fusion surgery is done to remove the damaged disc, and stimulate bone growth in that same area. Fusion of bone means that the space once occupied by the flexible disc will be occupied by bone that will not allow motion at that spinal level. Once the bone fuses across the disc space, the vertebrae above and below the damaged disc are locked together. By securing the vertebrae together, the spine does not move at this segment, and the pain relief can be excellent.

However, there are several problems with spine fusion surgery. First, the rate of successful fusion is about 80%. While complete fusion of the segments is not always necessary for pain relief, it is concerning that we cannot always find a way for bone to grow across the damaged disc space.

Second, fusing a spinal disc space decreases the motion of the back, and may lead to symptoms of stiffness. Finally, because of the stiffness when the fusion is performed, the segments of the spine above and below the fusion are subjected to increased stresses. Patients who have a fusion at one level are more likely to develop problems at discs above or below (so-called adjacent levels) down the road.

Lumbar disc replacement is similar to other types of joint replacement (such as hip and knee replacements). The concept is similar that the surgeon is removing a damaged joint, and replacing this with a metal and plastic implant. In the lumbar spine, the goal is to remove the damaged, painful disc, and replace this with a metal and plastic implant. The implant is designed to move like a normal disc.

The theoretical advantage of lumbar disc replacement over spine fusion is that the replaced disc would allow motion at the damaged level and would not transfer stresses to adjacent levels. The goal is to achieve the same pain reduction as spinal fusion, but eliminate some of the complications.

Unfortunately, lumbar disc replacement is a new surgery. While it is tempting to accept that this is a "better" treatment (pain reduction with less complications), we do not know if that is really the case. Lumbar disc replacements can break and they can become infected. Furthermore, the metal and plastic can itself wear out causing problems down the road. The question is which treatment offers the best result with the lowest complication rate. The answer, right now, is that we do not know. Lumbar disc replacements have not been performed on enough patients for a long enough time to know what potential problems may arise from this surgery.

Where Are We Now?

A recent review in the journal Orthopedics Today reported the findings of several European studies. These studies found good results in about 75-85% of patients. This is about the results expected with spinal fusion. Unfortunately, these studies only lasted about one year, and thus the long-term results are not well understood.

More research needs to be done before lumbar disc replacement is a standard option for degenerative disc disease, but it could be a future treatment.


"Lumbar Total Disc Replacement Yields 72% to 86% Good Result" Orthopedics Today: Vol 24, No 2, Feb 2004, Page 26.

Lin EL & Wang, JC. "Total Disk Arthroplasty" J Am Acad Orthop Surg 2006 14: 705-714.

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