Most cervical disc implants are still in the clinical trial stage. The US Food and Drug Administration studies each new device as they come on the market. First, studies are done on a disc replacement at a single spinal level.
If the results are good, then they can try them on more than one level. The third step is to expand the group of patients who qualify. Just recently a group of doctors in Australia tried the Bryan cervical disc implant in 15 patients who had previous neck surgery. They either had a cervical spine fusion or a foraminotomy (bone removed to take pressure off the spinal cord or spinal nerves).
The early results were good. Researchers will continue to follow this group for long-term results. Another study with more patients will come next.
Cervical disc replacement after a previous surgery isn't standard yet. It may become one of a patient's many options in the near future.