I have not dealt with it at all, but know of a few cases in Miniature foals. I dont believe that there is any way of dealing with it other than surgerynot when it is bilateral. In the bilateral cases I know of the foal has been unable to stand; a crouch is about the best the foals could do and even that was difficult for them. If only one leg is affected the owner might be tempted to leave it alone, because the foal can walk on the good leg, at least for awhileoften that leg gives out due to the added stress on it. Surgery involves making the groove deeper so that the patella will stay in place.
I dont honestly know what the surgery costsand no doubt it differs clinic to clinic; I doubt that it is inexpensive. Lilhorseladiedid you have the surgery done for luxation (dislocation) or for locking stifle (upward fixation)? The surgery to correct upward fixation is quite simple and inexpensive. The surgery for luxating patella is more extensive and therefore expensive. I know people who have had it done on their small dogs and the cost was $3000 to $5000. I have not heard a dollar amount that anyone paid for the surgery on a foal but would guess that it is right up there too.