Painful symptoms from a herniated disc can limit function and really reduce quality of life. If the condition gets worse, patients can end up with irreversible neurologic damage. That’s why surgery is recommended if conservative care doesn’t result in any change in the clinical picture.
Pressure on the spinal cord from a disc protrusion or herniation in the neck is called cervical myelopathy. Anything in the spinal canal can cause a narrowing of this opening designed to let the spinal cord travel from the brain down to the base of the spine. Besides disc material, bone spurs, hardening of the spinal ligaments, and arthritic changes of the facet (spinal) joints can change spinal alignment resulting in pressure on the spinal cord.
Because disc replacement is a fairly new procedure, there remain questions about whether disc replacement versus spinal fusion is the best treatment approach to the problem of cervical myelopathy. Disc replacement preserves motion but might cause ongoing microtrauma to the spinal cord if the implant puts any pressure on the spinal cord. Fusion eliminates any ongoing microtrauma but limits motion and may increase stress and load on the vertebral segments above or below the fused level.
There are no direct studies comparing the two methods. There has been one review published in 2008 in which surgeons looked at the results of two large studies — each one evaluated one of the two procedures separately. By comparing the final outcomes of each approach, the authors of that study could give us some idea how these two approaches stack up against one another.
The results were measured using patient reports of neck and arm pain, function, gait (walking ability), and self-reported general physical and mental health. They found that either treatment worked well and the myelopathy did not get worse after disc replacement. Treatment was restricted to one spinal segment and patients were only followed for two years.
Since that time, cervical disc arthroplasty (replacement) has continued to be used in younger patients who don’t have a lot of degenerative changes seen in older adults. When pressure is placed on the spinal cord because of disc protrusion, then disc replacement is the treatment of choice. Cervical disc arthroplasty is not recommended when the patient has bone spurs, significant wear and tear on the facet (spinal) joints, or other age-related changes.
Other contraindications to cervical disc arthroplasty include fracture, unstable segments due to rheumatoid arthritis, or previous surgery to remove the lamina, a supporting column of bone that’s part of the vertebra. Contraindication means reasons why something should not be done, in this case, the disc replacement. Anything that might compromise the stability of the spine is considered a contraindication. Infection, extreme obesity, osteoporosis (brittle bones), or other arthritic conditions that limit spinal motion are also contraindications to cervical disc arthroplasty.
Your surgeon is the best one to advise you in this matter. Once all the information is gathered from the tests that will be done, the pros and cons of each procedure can be evaluated. Surgeons are aware of the pitfalls of each approach as well as what patient factors to take into consideration. Age, previous spine surgeries, age-related or other degenerative changes in the spine, and location of the herniation are just some of the things the surgeon will be taking into account when planning the best treatment for you.