Hi Beckel! I have had two ACDF's; one of the C3/C4 in 2004 and one of the C5/C6 in 2006. So, you see, I have one (C4/C5) sandwiched in between. Your surgeon said the same thing my own did. And here it is 2012 and I am still doing well as far as my neck is concerned. It doesn't mean things won't go south but I have asked about the domino effect repeatedly. My own surgeon says it is not necessarily true. So, so far so good. It is my lumbar I have been dealing with lately. Anyway, good luck to you!