If you are contemplating surgery, please don't ever let a Doctor fuse your vertebrae. Read through this link before making any decision -
https://www.axiomed.com/pdf/WPaperSWISSSpineReg.pdf
I have no dog in this fight, other than I will be getting a multi-level surgery with Dr. Guyer at the Texas Back Institute, once the Freedom Lumbar Disc clears FDA approval.