Should You Have Disc Replacement Surgery or a Spinal Fusion?

Spinal fusion and disc replacement are two surgical methods used to treat certain types of spine issues, especially degenerative disc disease (DDD). Each type of surgery has its risks and benefits and involves recovery time and rehabilitation.

About Degenerative Disc Disease

As a structure, the spinal column is made of stacked vertebral bones separated by spinal discs. Each disc is composed of tough, but pliable collagen fibers that help maintain the position and integrity of the spine while allowing movement between the vertebrae. This complex structure provides us the stability needed to stand upright, as well as the flexibility to bend and twist in multiple directions.

With time, discs degenerate. While this is a normal process that occurs in everyone, the medical community has historically called this problem DDD. This can be due to various reasons, such as old age, daily activities and sports, or injuries. To an extent, this type of deterioration is normal; most people by age 60 will experience it to some degree.

People can have disc degeneration that doesn't cause any problems, but sometimes, it can lead to pain.

Disc Replacement vs. Spinal Fusion

Though the two surgeries have similar aims, there are important differences between them. In short, disc replacement is a newer, less-proven approach, but it may have advantages compared to spinal fusion.

Goals of Each Surgery

Before considering surgery, treatment for DDD should focus on non-invasive or minimally invasive options. Surgery for DDD is controversial and it is considered a last ditch effort to treat low back pain when an exhaustive course of conservative methods like physical therapy and anti-inflammatory medication don't provide relief

Spinal fusion has been the standard surgical treatment for DDD when surgery is needed. The goal for spinal fusion is to correct deformities of the spine by fusing two or more vertebrae together to increase stability and decrease motion that may be causing pain.

In a spinal fusion procedure, a damaged disc can be removed and replaced with a bone graft to stimulate bone growth. Over time, the space of the absent disc gradually fills with bone, fusing the vertebrae.

On the other hand, lumbar disc replacement is similar to other types of joint replacement, such as those involving the knee or hip. The difference here is that while the cause of hip and knee pain in arthritic joints is well known, the cause of low back pain is not well understood. The surgery involves removing a damaged disc and replacing it with an artificial disc that mimics a healthy one, which can preserve the spine's mobility.

Pros and Cons 

There are pros and cons to both surgical methods. Spinal fusion has been a standard procedure for spinal conditions since the 1890s. Conditions like DDD can cause the vertebrae of your spine to move poorly, be unstable, and absorb more load than normal, potentially causing pain. Spinal fusion may help eliminate pain by stabilizing the spine and limiting pain-causing movements of one or more vertebrae.

However, because adjacent bones are joined together in a spinal fusion—eliminating all movement in that level of your spine—the way your spine moves after the operation may be altered, with extra pressure being placed on the adjacent joints.

Problems with spinal fusion surgery can also include:

• Fusing the spine may lead to back stiffness and a loss in the range of motion.
• By fusing the spine, the segments above and below the fusion are subject to increased stress, and people who have undergone fusion may be more likely to develop problems with the adjacent discs in the future.

Total disc replacement surgery is intended to preserve your spine’s mobility and help reduce post-surgical degenerative changes in the neighboring spinal joints.

However, this does not suggest that lumbar disc replacement surgery is not without its own limitations.

These include:

• Disc replacement surgery is less common than spinal fusion and is newer in origin, with the first procedure done in the United States in the year 2000. Studies looking at long-term success rates, especially compared to spinal fusion, continue to emerge. Current success rates for lumbar disc replacement are mediocre at best, and are estimated to be around 60% to 70%.
• While newer prosthetic discs offer greater durability, they can still wear out and may require additional surgeries down the road.
  

What the Research Says

When comparing the two procedures, some research shows that there is not much of a difference when it comes to success rates, which is why surgery is typically not recommended to treat low back pain.

A 2017 study published in the Global Spine Journal compared outcomes between lower back total disc replacement and lower back fusion surgery. The researchers found that disc replacement patients showed more improvements in pain relief and disability than spinal fusion patients at every post-surgery time period studied (six weeks, three months, six months, and one year).

In addition, two 2020 systematic reviews, one published in the journal Turkish Neurosurgery and the other in the journal Medicine, found that disc replacement surgery yielded better results in factors like pain and range of motion when compared to spinal fusion.

With that being said, the potential benefits of a disc replacement surgery compared to spinal fusion can sometimes make disc replacement the preferred treatment option. However, treatment decisions should be made in consultation with a healthcare provider or surgeon.

Surgery Eligibility

Not everybody is eligible for disc replacement or spinal fusion surgery.

Your doctor may recommend disc replacement surgery if:

• You've had no prior joint disease
• There's no compression on the nerves of your spine
• You've had no previous spinal surgery

Your doctor may not recommend total disc replacement surgery if you have conditions like:

• Central or lateral recess stenosis
• Facet arthritis
• Fracture
• Scoliosis
• Spondylolysis and spondylolisthesis
• Herniated disc with radiculopathy
• Osteoporosis
• Pseudarthrosis
  

Similar to total disc replacement surgery, your doctor may recommend spinal fusion if you've had no prior joint or spinal conditions and haven't had spinal surgery before. Your doctor may not recommend spinal fusion if you have conditions like severe adjacent segment disease or non-symptomatic spondylolysis.

Financial Considerations

The cost of disc replacement surgery can range anywhere from $30,000 to $45,000 or more depending on location and if more than one spinal disc needs to be replaced.

Similarly, the cost of spinal fusion can range from $73,000 to $82,000 or more, but costs can vary due to location and the nature of the procedure—for example, if multiple vertebrae need to be fused.

Summary

Spinal fusion and disc replacement surgery are two surgical methods utilized for spine disease, especially DDD. Although some studies show that the success rates of both surgical procedures are about equal, emerging research shows that there may be some potential benefits with total disc replacement surgery, such as preserved mobility and decreased pain.

However, it's important to talk with your doctor to see which procedure would be best for your condition and lifestyle.

A Word from Verywell

If you develop severe back pain of any sort and believe it may be DDD, it's important that you get evaluated by a doctor to pinpoint the exact cause. You may be able to avoid surgery and alleviate problems with conservative measures like anti-inflammatory medications, physical therapy, and epidural steroid injections.

Be sure to talk thoroughly with your doctor about the risks and benefits of a spinal fusion or disc replacement surgery if you're considering surgery.