I've made up my mind to go with a disc replacement for my neck instead of a neck fusion. Now give me the skinny on the problems I might expect with this approach. I don't want to go into this blind.
Your surgeon, of course, will review all of the potential problems and complications that can occur -- some from any type of surgery and others related to this specific type of procedure. Not everyone is a good candidate for this approach, so you will have to find out from your surgeon (if you haven't already) whether or not you qualify.
The goals of a good fitting design are first to maintain the space between two vertebra (in other words maintain disc height). Preserving motion at that segment is equally important. And providing shock absorption while keeping the proper spinal alignment is important, too. The implant should be durable (last a long time) with few (hopefully no) complications or problems.
A good fit can depend on how the device sits in-between the two vertebral bones. Different shapes of implants have been tried and different methods of "fixation." Implants can be round, square, saddle-shaped, triangular, and square with rounded edges. Some implants are serrated while others have teeth or keels to help them grab hold of the bone and stay where placed. Screws and cement have been used to aid fixation.
But the method with the best results (fewest complications, minimal debris, lowest rate of adjacent segmental disease) has yet to be determined. Studies are ongoing comparing cervical disc replacement with the standard treatment (anterior cervical discectomy and fusion or ACDF). And now with five CDR devices to choose from, research is being done to compare the results among the currently available implants.
Overall, research results show that patients who are treated with either fusion (the ACDF procedure) or cervical disc replacement (CDR) all get better. They all have less neck and arm pain and fewer neurologic symptoms (e.g., pain, numbness, or tingling down the arm).
There is always a concern for adjacent segment disease or ASD as the most likely complication. ASD is defined as degeneration of the disc at the level next to the fusion or disc implant. This seems to be improving with cervical disc replacements. These results may be explained by the fact that the implant preserves motion, so there is less pressure on the discs above and below the surgical level.
Reported complications with either procedure (disc replacement or fusion) include difficulty swallowing, vocal cord paralysis, penetration of the esophagus or dura (lining around the spinal cord), infection, and hardware failure. In the case of disc replacement, there have been rare episodes of device migration (disc implant shifts or moves significantly), spinal cord compression, and bone spur formation around the implant. Some of these problems required removal of the disc implant.
Long-term concerns include adjacent segment degeneration and wear debris from tiny flecks of metal getting into the area from the implant. There have been some questions raised about the long-term safety of disc implants from studies that showed chronic inflammation around the implant and in the spinal cord. All metal implants have an increased risk of a hypersensitivity (serious allergic) reaction.