eOh, I don't think that pre-existing facet issues are under-appreciated as a source of post-adr problems. This is extensively discussed at every meeting and in most presentations about ADR. More severe facet issues are an absolute contra-indication for ADR.
Having said that, the discussions of facet issues also demonstrate the unpredictability of spine surgery. I've seen cases presented with grade III facets pre-pop in which the facets have recovered and improved in the years following ADR. (Facets are graded I to IV with grade III representing moderate to severe degeneration, IV being severe.). I have also seen cases presented where pre-op good facets go bad after ADR.
Some might make an assumption that the cases going bad after ADR would have been successful if a fusion was done instead of ADR. In the discussions we had regarding failed back surgery syndrome with Dr. Hochschuler of TBI at the GPN symposium, he reiterated what I hear at all the conferences. "A very high percentage of the patients that fail ADR would have likely failed with fusion as well." (<-- paraphrased by mmglobal) This is evidenced by the number of cases in which the patient has an apparently successful ADR surgery that they tolerate well and recover from well... they just do poorly on all clinical outcome measurements. This is followed by an apparent successful fusion that they tolerate well and recover from well... but they just to poorly on all clinical outcome measurements.
I have seen many successful fusions in the patient community... both as a first surgery and as a revision for failed ADR surgery. Yes, the facets are key players in many failed surgeries. I think that 2 things are very clear:
1. Either we don't yet understand the system well enough and there (currently) no way to effectively predict success/failure for any/most spine procedures... or:
2. There is a randomness of failures that will never be understood...
I have a theory that I've been discussing with the spine surgeons for years. Most of them will first laugh at it, then they will agree with it:
All major spine procedures come with a success rate that is at best, about 85%.As the technologies develop, we get improvements in the system and get better and better options. I believe that 15 years from now, what we do today will seem barbaric and outdated... but the success rates will still be 85%!
Mark