Disorders of the Stifle in Horses

Last Updated on March 29, 2022 by Allison Price

Fracture of Stifle

Rarely are severe fractures of either the femur, or the tibia in the stifle. These bones can be difficult to treat due to damage to the joint and ligaments as well as cartilage and soft-tissue swelling. Minor fractures can be treated depending on what type of fracture. You can treat some fractures of the patella, tibial tuberosity, kneecap and femoral condyles. To confirm the diagnosis, X-rays will be required. While some conditions can be treated conservatively, others require surgery to fix large fractures of bone.


Gonitis refers to inflammation of the stifle. Due to the complexity of the joint, many causes can be identified. These include osteochondritis scutans, locking of the kneecap in an extended location, injuries to the ligaments and menisci or cartilage, erosions or infections of the joint cartilage or puncture wounds.

The cause of the condition and its severity will determine which signs you see. It is quite common to experience mild to moderate joint inflammation due to an unknown cause. As a result of a shorter forward phase, lameness can be seen in the swinging leg. The horse may rest with the fetlock straight and only the toe touching ground. Lameness can be observed in the supporting or swinging legs in moderately severe cases. The horse may be forced to carry the leg bent in severe cases. A crackling or grating sound could be heard if the ligaments or cartilage have burst. Ultrasonography is a way for your veterinarian to see ligaments, cartilage and soft tissue. X-rays can confirm the presence of bone or cartilage.

Disorders of the Stifle in Horses

Long-term rest is often necessary. It may be beneficial to inject steroids or hyaluronic acids into the joint several times. In less severe cases, anti-inflammatory drugs or whole-body steroids can be used to relieve lameness. The majority of cases of gonitis caused by rupture of ligaments and damage to the joint cartilage do not respond well and can quickly progress to secondary arthritis. If the condition is severe, long-term, or if there have been serious injuries to the joints, ligaments, and joint cartilage, the chances of recovery are poor.

Dislocation of the Kneecap

Horses are not known to have true dislocation of their kneecaps. It is rare for horses to experience true dislocation of the kneecap. The dislocation is often very obvious. Congenital dislocation is possible in some breeds.

Upward fixation, or locking of patellar ligament is the most common problem with the kneecap. This condition is more common in pony breeds. Immature animals may experience dislocation if their thighs are weak. This may affect one or both of the hindlimbs. It can be described as an intermittent locking of one or both hindlimbs in extension, followed by a sudden jerk of overbending the joint when patellar ligament unlocks. These signs are more common when the horse is standing still for any length of time (e.g., after being transported in a trailer or overnight in the stable). The signs can be less obvious, making diagnosis more difficult. It could simply be that there is a lack in hindlimb forward motion and a jerky patellar movement.

The problem can be solved in many cases by a general increase in fitness and muscle tone in the hindquarters. Surgery to realign the kneecap might be recommended for more serious and persistent cases. Rest must be allowed to heal completely (4 to 6 weeks), before you can resume training.

Bone Cyst beneath Cartilage

Many cyst-like structures, large and often cyst-like, can be found in horse bones. They are most common in the stifle, but less frequently in the fetlock. Although their causes and development are still not fully understood, they could be caused by trauma to the joint cartilage, or as a result a bone or cartilage disorder (e.g. osteochondritis dissecans).

Cysts are more common in young Thoroughbreds, aged 1 to 2 years. When training starts, you may notice lameness. Although the cysts are most common in the knee joint, they can also cause severe lameness and pain. A diagnosis can be confirmed by X-rays. Some horses will respond to treatment with anti-inflammatory medications and rest for up to six months. Surgery is recommended for complete cysts or animals that are more mature. There are many surgical options available. Because of the positive results that surgery tends to bring, you may consider it before more conservative treatments.

Allison Price
Allison Price

I’m Allison, born and raised in San Diego California, the earliest memory I have with horses was at my grandfather’s farm. I used to sit at the stable as a kid and hang out with my Papa while he was training the horses. When I was invited to watch a horse riding competition, I got so fascinated with riding!