It doesn't replace the whole disc, just the nucleus (the squishy part in the middle). It used to be that they had to replace the whole disc which meant some type of metal or plastic thing plus a squishy middle part. Now they've found that in people who have their disc degenerated to the point where the nucleus is leaking out, but where the disc has not completely collapsed in on itself that they can leave your own disc minus the nucleus in there. They suck out the nucleus & then put this inflatable pouch into your disc. Then the inflatable part is filled with gel. Supposedly, it will prevent the stress that is normally inflicted on the surrounding discs after a full disc replacement. As I understand it, a lot of times the discs above or below a replacement disc can end up getting more deteriorated than if the real disc was left in. This is supposed to correct that issue b/c you still have the same shell of your disc, it just has a new inside.
They have been doing this in other countries for some years now with incredible success (nothing's perfect, but this is supposedly leaps & bounds better than the alternatives). My favorite part is that there is hardly any cutting at all. Because of a congenital condition, my injured muscles don't ever heal so I try to avoid any damage to them, including surgery. For some people the surgeons can just go in through the abdomen & weave their way around muscles & organs to get to the damaged disc. Now it is in the final stages of FDA trial here in the U.S.
The places that trained to participate in the FDA trial are:
Greater Baltimore Neurosurgical Associates
Rocky Mountain Spine Arthroplasty Specialists
The Center for Diseases & Surgery of the Spine
The Spine Institute at St. John's Health Center
Needless to say, it all sounds pretty exciting to me. I wish there were more places doing it right now, but I guess they do have to have some controls in order to make sure they get valid study results. :(
Hopefully in another year or so it will be available everywhere, but for one I can't wait that long b/c I need to get well to get back to work and for two who knows whether or not the evil insurance companies will cover it right away so I figure better to get in the study group so I can get mine for free.