I think they inject cortisone as close as they can to the joint, and it diffuses the rest of the way. Or at least that's how I understand it from here: http://www.ivis.org/proceedings/AAEP...0102000257.PDF
Neither of our horses have insurance, so it's all out of pocket
Of course I won't know anything for sure until the vet gets here. Just waiting on him. He rehabbed my friend's mare who tore a ligament in one of her legs and was out for two years. Lots of stall rest and laser therapy, but she's back in lessons as of a few weeks ago, 100% sound. I have confidence in him. I have no idea what to expect for Zeus though. If he's pasture sound, that's fine. If he's only light riding, that's fine, too. As long as he's comfortable.
Zeus is feeling tons better today. Almost no soreness in his back! But same as he always has been in his plunky walk. Thinking about getting something from Back on Track to help. I've been rubbing liniment on him and twiddling my thumbs waiting for his appointment.