As it's good to consider all options before going into surgery I've found that a chiropractor for someone with herniated discs is a no no. Could potentially cause more damage and typically someone who is a candidate for a fusion is beyond to point of such traditional means of treatment. Although each person is different but it sounRAB as though since you're asking about a chiro that maybe you haven't really exhausted all your options. I could be wrong but it's easier for people to give you answers to your questions if you fill us in more of what your situation is and what options you have tried thus far.
Hope this helps and also I hope you find some answers to your questions.
-Karl