Your concern is a legitimate one and one that you may want to bring up to your surgeon for discussion. She will be able to answer your questions and allay your fears. But let us give you some information that might help.
Surgeons have all manner of tools available to them now that have advanced their technical abilities during surgery. For example, preoperative X-rays and fluoroscopy (real-time 3-D X-rays during surgery) make it possible to line everything up accurately and with more precision than ever before.
Some disc replacement systems involve using a special machine that makes all the cuts. The surgeon lines everything up carefully but the machine makes even, equal amounts of bone cuts from each end. With this capability, bone resection isn’t a significant factor.
They even have computer programs that measure (in square millimeters) exactly how much bone has been removed. That gives the surgeon some feedback to gauge how much bone has been resected.
Studies show that there are some important factors that can predict who will have better motion after surgery. Men are more likely to have better motion than women. Patients of either sex who have the most motion before disc replacement have the best results after surgery.
Getting the disc implanted at the right angle and in the best position are technical factors only your surgeon can control. Patients must choose their surgeon carefully just as surgeons must select patients for this procedure with equal care.
Patients who have severe, advanced degenerative disease may be better off with a spinal fusion than a disc replacement. This is something surgeons and patients usually decide together. You may have already had this conversation with your surgeon, but if not, it’s always good to review what all your treatment are, which ones are best suited for you, and why.