Hi there,
My yorkie "Bailey" has the same problem and my vet told me almost exactly what you said your vet told you. I'm not sure what grade Bailey's was at, but it was bad enough that it was popping out of the socket and I'd have to push it back in and realign it. My friend used Glucosamine for her Bullmastiff and it changed the Bully's life! I decided that while I contemplated on the surgery, I could do some research on vitamins that yorkie size. I called the vet back and asked what she recommended. I put Bailey on Synovi Granuals. Since I started Bailey on the Synovi, his leg has not popped out of the socket. I don't have to hear him screech in pain or see him limp (even when he plays a lot). I'm so that I found this for Bailey! It may be worth a shot for you, if anything you know it can't hurt him because they're vitamins. I would suggest that you check with your vet first if you consider the Synovi because I wouldn't want you taking my word alone. I get my granuals at the vet's office, but I think if you google it you may find a site to order from. Let me know if you have any questions!