Neck pain and cervical spine disorders are prevalent conditions that can severely impact your quality of life. Most of the time, non-surgical treatments including physical therapy, medications such as steroids and anti-inflammatories, and time provide relief. However, sometimes problems with the discs in the neck can produce either a herniation or bone spurs that cause pressure on the nerves or spinal cord in the neck. When this happens severe pain, numbness, tingling and oftentimes weakness radiate down from the neck into the arm and the hand.

When Should You Have a Fusion or Disc Replacement?

Nerve pain does not generally cause neck pain or headaches but instead causes pain where the nerves go, namely down the arm and into the hand. Pain while sleeping and discomfort while driving or sitting, with some improvement with movement are common. Most episodes of this pain, called radiculopathy, do resolve over the course of about six to eight weeks. When the pain does not resolve or if severe weakness is present such as not being able to grasp objects with the hand, not being able to pick up objects because of weakness, or not being able to raise the arm overhead, surgery is a great option to relieve the pressure on the nerves.

There are two mainstays of surgery in the neck. Anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA), also known as artificial disc replacement, are the two commonly performed surgical techniques for treating cervical disc degeneration and herniation. Each has risks, advantages and limitations which are discussed below.

What is Anterior Cervical Discectomy?

Anterior cervical discectomy and fusion (ACDF) is a widely practiced surgical procedure aimed at relieving symptoms caused by cervical disc herniation or degeneration. During ACDF, the damaged disc is removed from the cervical spine, and the gap is fused using bone grafts, plastic or titanium cages and a small plate and screws to stabilize the spine. The fusion process creates a solid bone bridge, immobilizing the affected segment and preventing recurrence of nerve pressure at the level involved. This surgery has been around since the 1950s with strong outcomes of more than 90% of patients experiencing marked improvement of arm pain and weakness. Because this is a well understood procedure that is performed very frequently in the United States, it can safely be done on an outpatient basis, often at a surgery center rather than at a hospital.

The Difference Between Fusion and Disc Replacement

Cervical disc arthroplasty (CDA), or artificial disc replacement, is a relatively new surgical technique designed to maintain motion at the affected cervical level while addressing disc pathology. During CDA, the damaged disc is replaced with an artificial disc prosthesis. The most appropriate reason to consider a disc replacement versus a fusion is in a younger patient with a disc herniation rather than arthritis. Advantages of disc replacement largely include preservation of motion, and work in the same fashion as knee replacements or hip replacements with similar components including metal alloys and plastic. The surgery and recovery are comparable to an ACDF; however, there is less motion loss with a disc replacement. Only one- and two-level disc replacements have been studied and are approved by the FDA.

Outcomes

Studies do indeed show that preserving motion with a disc replacement does result in lower pressures at the discs above and below the replacement, but clinical outcomes, meaning improved pain and function after surgery, are about the same as with a fusion in well-selected patients. Additionally, studies have shown good patient outcomes for disc replacements to continue to function well for nearly a decade. Since disc replacement surgery is relatively new, the orthopaedic community does not know the longevity of the surgery at this time. However, based on the industry’s experience with knee and hip replacements, longevity is roughly estimated to 20 to 30 years.

The decision between ACDF and CDA should be based on individual patient characteristics and surgeon experience. Ultimately, the goal is to provide patients with the most appropriate treatment that offers the best chance of symptom relief and improved quality of life. As research and technology advance, both procedures continue to evolve promising better outcomes over time. At Wake Orthopaedics, we are well-experienced in both treatment options as we believe in fitting the procedure to the patient rather than the patient to the procedure.

Frequently Asked Questions – Cervical Fusion

Are there any limitations in activities?

No, in the long run the fusion is as or more stable than a normal spine. Once the fusion is healed, you cannot break it regardless of activities. Because the surgery is stable to begin with, there are no necessary restrictions on range of motion.

Will I lose range of motion in my neck after a fusion?

The answer to this is more complicated. Research looking at motion after an ACDF for one disc space shows that range of motion increases by one to two degrees on average. If two discs are involved, average range of motion decreases about four to seven degrees. If three discs are involved, average range of motion decreases by about 10 degrees. Since overall neck range of motion is about 120 to 150 degrees, motion loss does not affect everyday activities to a large degree.

Does a fusion make me more likely to need another operation in the future?

In theory, the more stiffness added to the spine, the more likely the levels adjacent to a fusion are to developing arthritis and cause similar issues. However, research has shown the opposite effect. This problem is called adjacent segment disease. The risk of adjacent segment disease after a one-disc fusion is about one in four over the course of a lifetime. The risk after a 2-level fusion is about 10 to 15%. After a three-level fusion, it decreases to about three to five percent. This is because there are certain levels in the neck that simply are more likely to develop arthritis. If those levels are involved in a fusion, they cannot get arthritis and therefore cannot cause adjacent level problems.

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About Conor Regan, MD

Dr. Conor Regan is a board-certified (FAAOS), fellowship-trained orthopaedic spine surgeon. He treats all disorders of the cervical, thoracic and lumbar spine, including adult and pediatric spinal deformity. He has special interest in the cervical spine and complex cervical reconstruction, as well as lumbar revision surgery, treatment of cancer of the spine and idiopathic scoliosis.

Dr. Regan has presented his research at the local, regional and national levels, and he has multiple publications in medical literature.