Welcome from New Orleans. I don't have much in the way of help to say. You are very brave and kind to take on the responsibility of a special needs chick. As some one else said there may be internal problems that don't show up for a while, have you been able to get the chick to eat and drink? I would look on BYC for a thread regarding a chick or chicken with similar problems. If you can't find one, start one. I would be as specific as possible in the title and I would carefully pick which forum you posted in. Good luck, give yourself a pat on the back for attempting something so many people would be afraid to try.
Let us know how things work out, please.