Wow... Thelma, great to see you here. I hope all is well!
There are many different facet replacement systems in various stages of development. I understand that they work well, but only for facet pain. Most of the people who would require a facet replacement will have other degenerative changes that may be other pain generators.
A very interesting varient of the facet replacement is the total segment motion system. These systems combing an ADR with a facet replacement. I've seen the TSMS surgery performed several times over the last few years. It is NOT just another ADR that allows implantation via a posterior approach. This is a big and fairly brutal surgery that is very invasive.
www.GlobalPatientNetwork.com/devices/tsms.html
Cheryl, has your facet pain been proven with injections? I would think that facet blocks would be helpful. If they are positive, then facet rhizotomies could ablate the nerves going to the facets... possibly resolving your pain without surgery. (Relief from rhizotimies may be temporary... they seem to last a year or two, but can be redone.)
All the best,
Mark