Hi Peter,
First of all let me say welcome to this forum and sorry you're experiencing the probs you are.
I'm wondering what diagnostics show in terms of pain generators such as myelograms, discograms, MRIs, CT scans and such.
Then I'm thinking (uneducated opinion here) that anyone with such a degree of surgerized spine may have offset the natural balance of things and have pain that is just mechanical/structural in nature due to surrounding structures having to adjust.
I may be way off there though my own experience has been that my L5S1 was operated on and then L4 was operated on. For a long time after that I had quite a lot of pain and differing types. I was told too much disc was removed at L4 making my spine more unstable but not enough for a fusion (was told I could have a 3 level global fusion 8 years later or two level ADR 11 years later or hybrid surgery 13 years later). Anyway I just think that one surgery often begets another or more problems.
Not with everyone I'm sure and there are of course reasons why people have pain/probs and some can be taken care of successfully and are and some maybe not.
I didn't want to chance the maybe not again so I just stuck with no more surgery to date. I live on low dose pain medication although have stopped taking a med that I took for 12 years (Neurontin) and am doing better.
In the scheme of knowing anything revelent to your particular case however I know nothing so the one person here that could probably help you the most would be Mark. I would speak to him.
GPN Artificial Disc Replacement ADR
Or pose a question to him here or hopefully he'll reply to your thread. There are others that are knowledgable as well that can give you better direction. I'm just "supposing" as they would say in English.
Good luck w/upcoming consults! Please keep us posted.