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Last Updated: September 29,  2021

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Acton Veterinary Clinic

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Veterinary Orthopedics

Choose Acton Veterinary Clinic for your pets orthopedic care

Torn ACL in Dogs (Cranial Cruciate Ligament Injury)

Most people have heard of a human athlete injuring their anterior cruciate ligament, or ACL, which is one of the critical stabilizing ligaments of the knee joint.

An ACL injury is also one of the most common injuries we see in dogs. With dogs, we call the knee joint the "stifle" and their "ACL" the cranial cruciate ligament (or CCL).

Partial or full tear of the cranial cruciate ligament can happen at any age and is frequently seen in middle to large breed dogs, particularly those that are overweight. This CCL injury is similar to a torn ACL in dogs.

When the cranial cruciate ligament is ruptured, the dog's knee joint becomes unstable. If left untreated, chronic instability leads to the development of arthritis and, as a result, pain. A torn cranial cruciate ligament cannot be repaired without surgery.

It is best to evaluate a patient for an ACL or CCL injury after an injection of sedation and pain medication, so the dog is relaxed, and we can manipulate the joint to demonstrate a "positive drawer test" and the presence of "tibial thrust."

If these are present, a rupture of the cranial cruciate ligament can be confirmed.

Once a torn CCL has been diagnosed, the next step is to determine which surgical cranial cruciate ligament repair procedure best suits the patient's anatomy. We make a decision based on calculations from the patient's knee joint x-rays, as well as lifestyle factors (activity levels, for example).

There are three canine ACL repair options:

1. External Capsular Repair
This was the original repair technique and essentially involves placing bands of very strong suture material around the stifle to stabilize the knee joint. This can be a good option for canine ACL repairs in smaller or less active dogs.

2. Tibial Tuberosity Advancement Surgery (TTA)
This procedure involves cutting the front part of the top of the tibia (the bone between the stifle and the tarsus, or ankle joint). The fragment is rotated slightly forward and upward, then held in place with a metal plate and screws. This surgery changes the forces acting on the stifle and recruits the large, powerful quadriceps muscles to keep the tibia in its normal position during standing. The TTA procedure is considered by many veterinary orthopedic surgeons to be one of the best methods for repairing a torn ACL in dogs.

3. Tibial Plateau Leveling Osteotomy (TPLO)
This technique involves cutting the back part of the top of the tibia. The fragment is rotated slightly backward and downward, then held in place with a metal plate and screws. This surgery creates a flat surface, as opposed to a sloped surface, for the femur (thigh bone) to sit on, so it does not slip backwards on the tibia during standing.

Our Expertise in Veterinary Orthopedics

Dr. Hess has performed hundreds of successful extra-capsular repairs during his career. After being trained by one of the top veterinary orthopedic surgeons in Canada, he is proud to also offer Tibial Tuberosity Advancement Surgery (TTA) for our patients.

Dr. Hess and the team at Acton Veterinary Clinic have performed many surgeries for cranial cruciate ligament repair with the TTA procedure, all with very successful outcomes. After a diagnosis of CCL rupture, Dr. Hess will be happy to discuss your dog's individual case and recommend the procedure best suited for your dog. Our goal is to return function of the injured leg to as close to normal as possible.