At 22 years of age I had spinal fusion. All due to a football injury while playing during a game. The college handled the operation and rehab cost. They had a prime medical center and very qualified doctor/surgery staff and still do. I'm 46 years old now. I do have occasional discomfort, but can't honesty say they cause me any serious pain. Maybe I'm lucky that way, we all respond differently. Of course the older I get, I will probably feel that more often.
A gave rehab a good six to seven months before returning to any form of heavier lifting. I did, and still do, get rolfing/deep tissue massages which really helped the lower back area. Also took up Hatha and Kundalini yoga, which I though was somewhat useless at first, but some good friends of mine insisted. I was very wrong about that, those stretches and hold also helped the lower back and whole body in general.
I liked to train heavy, it's in my nature. I like the rattle and clang of a loaded BB. I returned to heavy training within a year of surgery. Have not had a major injury since that time., back or otherwise. Just have to apply a bit of caution and reason to any exercise and the lower back. I did find that the Goodmorning exercise helped the lower back very well, for me anyway. Have even done heavier partial reps with GM'ings.
Good Luck.