If you feel up to it, you may want to check out the links in this thread:

http://neurotalk.psychcentral.com/thread45284.html

The reason I bring it up is that, when surgery is something you need, it could be helpful to have the info. in-mind (while consulting with surgeons):

http://neurotalk.psychcentral.com/thread45284.html

I've a feeling that you'll know when the time is the time for you - based on your symptoms and exams, along with your films, etc.

Quality of life, along with levels of feeling, functioning and pain will assist you in making the decision right for you.