Stifle issues-upward fixation or locking patella.
which has an article on "Unlocking Stifle Problems" by Michelle Anderson. This article deals with
UFP / upward fixation of the patella and for the most part is sound advice. The problem we frequently see in our practice is the unfit (I thought it was fit) horse. This problem (UFP)
arises from a laxity of the Medial patellar ligament which is part of the horses reciprocal apporatus
or locking mechanism which allows the horse to rest standing up. With UFP the ligament is lax or longer and hangs up on the medial side of the femur which causes pain and a stiff leg which drags
the toe behind. Frequently this leg "pops" as the limb comes forward. The old treatment was to
"clip" or "cut" the stifle. This is a surgical procedure where the medial patellar ligament is severed to prevent it form locking. The downside to this is a BIG one.....fracture of the patella. In 15-20% of the cases this occurs and can do so at anytime after the surgery leaving you with an expensive pasture orniment. The only time we do the procedure anymore is in cases where the limb is locked and we are unable to reduce it by backing up the horse. The best treatment is exercise, either straight line or long line lungeing. This builds up the quadricep muscles and thereby pulls the patella into place eliminating the problem. This can require significant amounts of time to properly condition the horse. The article also mentions injecting the joint with counter irritants. This is a NO-NO. No irritating substance should ever be put into a joint,
you can however, inject these substances into and around the medial patella ligament to try and cause local inflammation and scar tissue making the ligament wider and hopefully stop the UFP.
This is frequently helpful but doesn't take the place of a good exercise program.
If you notice this happening to your horse have a thorough lameness exam done to rule out other potential cause and when thats done ......start working your horse.