Damn. I had that done and went back to work. It never crossed my mind to get a SSD retirement. 
Id say that's because you aren't a primitive. I know of one other person who had that procedure, and a severe case of Lyme Disease who tried to go back to work but couldn't do her former job -and instead transferred to an office position. She stayed employed until her actual retirement date and didn't get out early.
Everyone else I know who had that procedure done hopped right aboard the Gravy Train.