There are two different artificial discs made by Medtronic; the Prestige and the Bryan discs. The Synthes disc is called the Prodisc-C.
The Prestige disc cannot be implanted next to another Prestige disc due to the interlocking screws that insert into the vertebral body. The Bryan disc however can be implanted next to another Bryan disc.
The Prodisc-C can be placed next to another Prodisc-C. There is some question that the keel of this disc can create questionable vertebral body weakness as when two discs were on top of each other, the two respective keels create a possible “wedge stress riser”.
The artificial disc was designed to possibly prevent adjacent segment degenerative changes. The theory was that a fusion was thought to increase the stress on the levels above and below. The motion of the artificial disc was then thought to reduce this loading. Current studies are not supporting this theory.
Artificial discs can and do wear out. No one knows how long they will last. The good news is that conversion to a fusion is generally easy and works well.
Dr. Corenman
