I’m afraid I don’t have personal experience of what happens once a horse goes home after surgery. I can however help with expenses as I used to work for an equine vet. The cost for a hock arthroscopy including GA is around £2000-£2500. Then on top of this you have the livery fees and bandaging material which varies. In total horses from my old practice used to go home with bills around £3000 after 5 days in horspital!
From a research point of view hock and fetlock have the best recovery prognosis. Followed by stifle. Shoulder is the worst recovery prognosis.