A girl on my old yard had a horse that had a locking stifle, The horse nearly ended up on the floor when it come out of its stable. Not sure about what treatment it had but she sold it in the end as it needed to live out. It used to lock when You first started riding him but it was ok once he got going.
Sorry not much help I just remember seeing him didnt really have much to do with owner.
Often work is the best way of treating it. As the muscles build up the mechanism that unlocks the patella works better.
Some vets advise a surgery where one of the ligaments that the patella hooks around is cut. It is quite a simple procedure but it may cause instability of the joint later in life, so is really a last resort.
As your horse is young it is quite likely that the problem will resolve with work as he matures.
I had the same experience with my 6 year old with his upwardly fixating patella. When he was unfit it would lock, especially when he first came out of his stable. Once he was in in work it got to the point that it simply wasn't a problem as the stronger muscles seemed to hold everything in place.
I would suggest using lots of hill work, suppling exercises on circles and raised trotting poles to help engage the hind quaters more & build the muscles up.
I've just taken on an aging shetland with arthritis in its back legs...it turns out its 5yrs old and has locking stifles!!! I also have a 9yrold with locking stifles. The 9yr old's only presented itself after a period of rest and now she is back out in the big hilly field I barely notice it. The shettie is better too now she is in my hilly paddock which I guess is down to muscle..
One of my 3 year olds has this VERY badly. I've never seen a horse with this as bad as she is. She has good days and bad days and right now she is a bit better but no way would you ever consider riding her; she's just too bad to be ridden. She is very very muscley and is living in a field with a large hill in it again - last time I put her in there she went downhill rapidly, but I am giving it a go again as a last ditch. If she doesn't pull out of this within the next year then it will have to be curtains for her I think.
I looked into having the operation on her however the research I came up with was way less than positive, therefore she is really on her own to recover.
My youngster had locking stifle and ended up having key hole surgery. After recuperating e had to do a lot of uphill slow walking to develop her muscles behind. She is now absolutley fine with no after effects. She now competes succesfully. Hope that helps
Tilly (4 yr old cob) has had locking stifles since she was approx 1 yr old. As she has got older, they tend to lock less and less. Sometimes she comes out of her stable and one is locked, but after reversing and turning her, she is soon fine and it doesn't seem to bother her at all. Vet thinks she will be fine with work (
if we ever get round to backing her!). Charlie (8 hh Falabella x Shetland) had surgery on his. Apparently it is very common in Falabellas. He is absolutely fine. Everyone I have talked to about it is of the opinion that work is the key to the problem.
I had a cob with a locking patella. i found that plenty of consistent regular work suited him fine and we rarely had a problem. Also as much turnout as possible.