Understanding stifles

Your horse’s stifle is the equivalent of the human knee. It is a powerful joint enabling the limb to flex and extend to propel your horse forwards.

Where is it?

The stifle is the meeting point of the tibia, which runs from the hock, the femur, which extends to the hip in your horse’s hind limbs and the patella or kneecap. At the points of articulation are two discs of cartilage called menisci. Two cruciate ligaments help to stabilise the joint and two strong collateral ligaments provide support on either side of the leg.

The stifle has a special mechanism which locks the joint so that the horse can rest the other leg or even sleep standing up, without falling over!

Stifle problems

Stifle lameness can be challenging to diagnose. This hard-working joint can be susceptible to potentially impeding developmental diseases such as locking stifles and osteochondrosis (OCD), as well as to arthritis and degenerative joint disease (DJD), cruciate ligament injuries and fractures.

Locking stifles

Sometimes the locking mechanism may not unlock or can lock at the wrong time – this is formally known as upward fixation of the patella. The condition is usually seen in growing young horses, where bone growth is exceeding muscular growth, causing a change in the angles of the joints. It is thought that horses with straighter hind limbs and weakness in the quadriceps muscles may be more susceptible to locking stifles. Mild cases of locking stifles can be successfully treated by building the horse’s condition and hind limb muscle. In more severe cases a special counter-irritant is injected into the ligaments to strengthen and tighten them and if this this fails surgery is the remaining option.

Osteochondrosis

Young horses can sometimes have a growth problem with the bone and cartilage in the stifle developing abnormally and this can cause swelling and lameness. Luckily the condition can often be treated