What is a disc arthroplasty?

A disc replacement. Certain individuals with lumbar or cervical disc disease can qualify for a disc replacement. Somewhat similar to hip and knee replacements done today. The purpose of this procedure is to maintain motion at the level with the disc pathology. This helps to prevent further degeneration of the disc that are adjacent to the level operated on in the future.
Disk replacement. Disk replacement is a surgery to replace the native disk in the neck or back. It is a newer technique that, though fda approved for safety, has shown marginal benefit in the low back. In the neck there is more theoretical benefit, however, long term results are pending, and the alternative of an anterior cervical fusion has a long track record of outstanding results.
Surgery... Depending upon the level of involvement; this is a surgical procedure aimed at correcting degenerative spinal disease/disc problems.
Replacement. Of your disk (cartilage shock absorber) in your neck between two bones (vertebrae) with metal and polyethylene. Similar to knee replacement in theory.