You and your dog are playing Frisbee in the back yard and he athletically leaps ups, catches it, and comes down wrong on his back leg. Now he is limping, holding his leg up, and barely touches it down. Likely, he has torn his ACL (anterior crucial ligament). Often pet owners just notice their dog is suddenly limping if they did not witness the injury.  A torn ACL occurs after a hyper-extension injury to the knee joint where the ligament in the center of the knee that attaches the back of the femur (the bone above the knee) to the front of the tibia (the bone below the knee) has torn. It’s the most common cause of sudden onset rear leg lameness in large breed dogs, but can occur in any size dog. Dogs that are overweight have a higher risk of ACL injury.

You must go to the veterinarian to have it diagnosed. Many times your veterinarian will have an index of suspicion for a torn ACLby feeling the knee joint. Many dogs need to be sedated to feel the abnormal “anterior drawer sign” where the knee joint slides abnormally when the ACL is broken. X-rays will also be taken to look for fluid in the joint and the subtle abnormal positioning of the femur in relationship to the tibia which occurs with a broken ACL.

Once your pet has been diagnosed with a torn ACL, he will need surgery. Sadly, a torn ACL will not heal on it’s own. With a torn ACL, the tibia and femur slide painfully and abnormally against each other every time your pet bears weight. Without surgery, your pet will continue to have pain and progressive arthritis in the joint which worsens throughout life. The three most common ACL surgical repairs are a Lateral Wire (only appropriate for small breed dogs), a TTA, and a TPLO. These surgeries are usually performed by a surgeon specially trained to do advanced orthopedic surgery. Which procedure is performed will be determined by the surgeon and based on your pet’s specific needs.

If your pet has a torn ACL, we refer to the Diley Animal Emergency Center where Dr. Alec Land performs the surgery that will be most appropriate for your pet’s specific needs. He is skilled at TTA, TPLO, and Lateral Wire procedures.