I honestly believe it's bad MBD, his legs should not look like that. I personally think it's amazing he survived this long. I assume the reason for his shaking and eye closing is heavy pain related to his MBD.
I'l tell you this honestly, I don't have much experience with MBD, but I know a horned frogs backlegs should not look like that.
I'm sure someone with more experience will tell you what you can do, but honestly, from what I've read and seen, it's not looking good.