Awe, poor little guy!
I don't know what I am looking at on the x-ray either, but I just wanted to say that I feel for you. I have a foal that was born with a leg deformity. It's always something, isn't it?
Interestingly enough, my friend has a Queensland Heeler puppy that has been limping on and off for months. Finally got a diagnosis and surgery and he had some little bone chips floating in his elbow. He got those removed and should be healing up nicely as we speak.
I got the impression that OCD is similar, with little bits of cartilage or tissue floating around or rubbing around where it doesn't belong, correct?
I wish him the best of luck and I hope you can get him heeled one way or another.