I agree with farmerman about the word hypothetical in science, which is a usual for me, but I did read something the other day, ok, yesterday, that fits in with this discussion as a sort of "in-between". It doesn't change my view on hypothetical, still same as Farmer's, just that this one took a lot of years of growing knowledge to develop - where as the OP's hypothetical was a kind of play, which I can get too, but hypothetical then not used in the scientific sense.
It has been understood, close to forever, that the spinal cord, once very damaged in certain ways, is unfixable. I'll have to grab the article to double check, and I will since I need to give the link, but I'll guess a couple of thousand years. Ah, it mentions a spinal problem on an egyptian papyrus from 1600 BC.
There is a way, though, that involves using olfactory ensheathing cells from the olfactory bulb in the brain and using them to create a new spinal pathway. This is because it was noticed that ordinary nasal membrane cells are oft refreshing themselves (interesting to me, since I have diminished nasal nerve endings, heh, mine don't do that)., and someone made the connection re nerve growth. Those don't really work, but going to the brain's olfactory bulb has. Cells refreshing (my word) can produce growth.
It's not clear from my reading that it can help all paraplegics because of differing types of damage but also time passing after the injuries, but there has been one big success to date.
New Yorker, Jan. 25, 2016
Annals of Medicine
ONE SMALL STEP
A paraplegic undergoes pioneering surgery
by D.T. Max
It's quite a good read re something doctors were quite sure about for a long time now. The solving part starts out with one cranky type guy not quite believing there could be no fix.
edited a few times, to be clearer