I have had 2 spinal surgical procedures and have stenosius with nerve damage. I ride a regular road bike 20 miles a day. It hurts alot but I keep doing it for the abscence of pain and for a workout. A roadbike with that slight hunched over position takes weight off my spine and feels OK.
I do not suggest doing this w/o first checking with your Dr. I would also take no ones advice on this forum except maybe for Dr. Pete.
Everyone is different.