Leesa is correct. There is indeed something called the domino effect and it happened to me. I was fused C6-7. NOT ALL the problems in my neck were addressed by that particular surgeon. I didn't even know there were more problems, he never told me. 6 years of pain later, I was fused 3-7. they all did indeed fall over like dominos. It was only after that second fusion that I got my records and found out I had also reversed the curve of my spine that was not addressed.
Do ask all the questions you can before going through another one. Make sure your doctors are positive that this needs to be done. Ask your doctor what is to stop this from happening above and below this new site.
I am indeed having trouble at C1-2 and T1-2. I am 20 months post op. New aches are happening but no neruo trouble. I wondered what the new hardware would do strain wise above and below and I still have that worry. I am very careful with my neck. I do wish you all the best. This might not be your situation at all, as you may not have the real degenerative disk disease and joint disease like I did. ginnie