Hi. My Lab has hip dysplasia. My vet gave me Piroxicam 10 mg. It helps her a lot. We give it to her every other day. She is 1 1/2 years old, though. He did say that surgery was an option, but, it was very expensive and often kind of backfired. My vet is a very good vet. He has never steered me wrong.
That is the only suggestion I can give. Your Lab is 11 years old...He has lived long. Most vets aren't going to recommend surgery at an age like that, because...they might not come out of it.
Do get a second an opinion, or a third...I'm not saying not to. Not at all. I have had to put a dog to sleep before, and it was so painful. There was nothing that could be done for him, though.

My thoughts are with you, and I hope you find a better alternative. I must say, though..if your baby can't walk too well, then...he's awfully depressed. I know you don't want to let him go. I wouldn't want to either. You'll know when it's the right time.
My thoughts are with you. I hope I was as sincere and thoughtful as I tried to be in this message.
-Trinity