Hi lyden and welcome to the forum,
I'm sorry for your wife's circumstances but am glad that you found us. You are both wise to seek more than one opinion and though we know no specifics about your wife's condition, it seems that fusion is a drastic measure for a first surgery, especially given that your doctor felt trying other non-invasion remedies first in hoping they might work.
Yes, two top doctors are still in Germany, I think. Dr. Bertagnoli is in Germany, and Dr. Zeegers used to be but has recently moved. Mark, the founder of this forum would know and utilizing his services is probably your quickest route to contacting both of them.
GPN Artificial Disc Replacement ADR.
Give him a call and please tell us more about where you are and a few more specifics about your wife's condition.
Dale