04/11/2025
โSticky stifles" in horses, also known as upward fixation of the patella or locking stifles, occur when the patella (kneecap) gets stuck in a locked position, preventing the horse from flexing the stifle joint and moving the leg forward.
* What it is:
The equine stifle joint has a mechanism that allows horses to stand sleeping with minimal muscular effort by locking the patella in place. Sometimes, this mechanism malfunctions, and the patella doesn't unlock, causing the stifle to stick.
* Causes:
* Conformation: Horses with straight hind limbs (post-legged) are more prone to locking stifles.
* Muscle weakness: Weakness in the thigh muscles, especially the quadriceps, can contribute to locking stifles.
* Trauma: Trauma to the stifle region can also make it more difficult for the patella to move freely.
* Signs and Symptoms:
* Extended leg: The affected leg may remain extended and dragged forward.
* Jerking: The leg may jerk upward to free itself.
* Short striding: The horse may shorten its stride on the affected side to avoid locking.
* Difficulty with transitions: The horse may have trouble with transitions, especially from a canter to a trot or walk.
* Stumbling: The horse may stumble in the hind end, which can lead to stumbling in the front end and potentially falling.
* Popping noise: The stifle joint may make a popping noise as it attempts to unstick itself.
* Treatment:
* Strengthening exercises: Focus on strengthening the quadriceps muscles to improve stifle stability.
* Corrective shoeing: A farrier can help improve hoof rotation and medial breakover.
* Weight gain: In some cases, gaining weight can help develop a larger fat pad behind the patella, which can help prevent locking.
* Veterinary intervention: In more severe cases, veterinary intervention, such as ligament splitting or injections, may be necessary.
Many young horses grow out of the condition as their muscles develop. With appropriate management, the prognosis for horses with locking stifles is generally positive.
