I know that everyone has their own theories, vets and owners alike, but from what I've learned from 12 years of dog ownership, when a dog shows signs of pain, he really is in pain! The vets should do x-rays first and then make assumptions it would be good to stretch out the scarred cartilage!!! His elbow is swollen and inflamed, it must hurt like hell! I know you mentioned you are going to take him for x-rays by the end of August, but honestly, if he were my dog, I'd find a vet who would do it immediately.