Cervical Disc Replacement

The problem: The spine is made up of similar repeating units, like links in a chain. When the cervical spine moves forward (flexion) or backward (extension), each joint contributes a small part to the total movement of the head.  If we can replace a disc instead of fusing it, there is less stress applied to the levels above and below the fused level.

When a disc wears out or is injured, after non-operative treatments have failed, the most common surgical treatment is to go in through the front, decompress the nerves and fuse the bones together, called ACDF surgery.  While fusion is the appropriate procedure in many cases, one consequence of fusion is that the joint above and below have more stress and are at risk of wearing out.

For example, in this xray to the right, the disc spaces above and below the fused segment show more degeneration five years later that might possibly (no guarantee!) have been limited had a disc replacement been placed at that level.

The stress on the levels above and below the fused level can accelerate the degeneration at those levels.  As an example, in this short video of cervical motion with and without a fusion, you can see that in a normal motion situation, the vertebral bodies are all lined up even as the neck moves in flexion and extension.  For the level above the fusion, you can see some subtle motion forward and backward indicating some additional stress on that level.

Therefore, in selected cases, there is an option to replace the cervical disc instead of fusing it. This treatment, which is done through the same approach to the cervical spine, allows for maintenance of motion at that particular segment, with at least theoretical benefit of preserving the discs above and below the fusion.