Thank you all so much for your thoughts and answers. To answer some of your questions:
Billy is probably 8-10 years old. I don't know because he was a stray when I found him. I have a "skid" -- it is as you described, but made of plastic. He used to have no problem with it, but now, he seems uncomfortable with it. I don't know if it is because he thinks he is now going to trip on it?
I was also thinking that maybe the garage reminds him of the kennel. When I first got him home, he wouldn't eat in the garage like he used to do. I had to feed him outside. Now, he is back to eating in the garage. Yes, fall is here, and he loves this weather, so I'm sure a part of it is he would rather be outside. But in the evening, sometime I used to sit in the garage with him and read; last night, I tried that, and he acted like he wanted to be there with me. He circled his (about 2" thick about 3' x 4') bed a couple of times, wobbled very slightly, then walked away. I took the bed away and put just a thin foam bed. He circled it a few times, and walked away. I replaced that with a rubber-backed throw rug. He circled it a few times, and walked away. I can't quite figure it out. And no, when I put his bed on the grass, he still won't lay on it.
I have used the kennel before and they do let them out in the yard several times a day to exercise and potty. The woman who owns it is the supervisor of the 4-H dog show at our county fair, owns a farm, and raises white GSDs, and I do trust her. I just think, being a Husky, he is uber sensitive, and because he's getting older, even more so, so that's why he paced and was nervous and eventually hurt himself.
We had bloodwork and xrays done before putting him on the Rimadyl and Tramadol, and no problems there. Yes, the Tramadol makes him sleepy which is good right now so that he rests his leg. I've been walking him slowly about 1/2 mile a day, because as you know, they get very demanding when they don't get their exercise. But he doesn't realize he still has to take it easy. Yes, maybe once this episode is over he'll feel more comfortable.
When he is outside, he does have access to the garage. I worry about him outside 24/7 because I'm paranoid. I'm always worried that someone is either going to steal him or hurt him somehow, even though I have privacy fence on the street side and chain link on all other sides. I do have one neighbor who is an @#$hole, so I'm never too sure about him.
He was off his food when painful, but now, he is eating well and the vet recommended a grain free diet to prevent inflammation, so that's what I have him on. Nature's Variety frozen raw food, Merrick canned, and Taste of the Wild dry. He loves all of it, and that figures, because it is pretty pricey. I am looking into making a raw food grain free diet for him myself to save a little bit on cost.
Yes, in the future, I will not kennel him. I am currently looking for someone who can either stay here and take care of him, or someone who can stop in a couple times a day to care for him.
Any other insight or advice would be much appreciated. Thank you again for all your comments -- you have helped.