I think it's jumping the gun to feel like it's impossible - I was offering options that could be temporary while you work back up to carrying the pack. My friend had a horse buck him off - after a previous back surgery. He failed to listen to the doctor about not riding horses, and tried to ride a green broke horse into the bargain. HIs problems are in the lower back.

I think everyone is different - and if the doc thinks it's possible to backpack again, listen to the guy with the degree and the experience who's looking at you in person, not people on the internet and their anecdotes.