The dog's cranial cruciate ligament (CCL) is frequently referred to as the dog's ACL or 'cruciate'. This connective tissue joins the upper and lower leg bones at the dog's knee and may become injured. Today, our Simi Valley vets explain the three main ACL surgeries for dogs.
ACL, CCL, or Cruciate - What is it?
The anterior cruciate ligament (ACL) is a thin piece of connective tissue in the human knee that connects the lower leg bone (tibia) to the upper leg bone (femur) and helps the knee function. Dogs have this connective tissue connecting their tibia and femur as well, but it is known as the cranial cruciate ligament in dogs (CCL).
While the human ACL and the dog's CCL function somewhat differently, pet owners and vets will often refer to the dog's cranial cruciate ligament as the dog's ACL, CCL, or 'cruciate' interchangeably.
How did my dog hurt their ACL?
ACL injuries in dogs usually develop gradually rather than suddenly, and they worsen with activity. There may not have been a defining moment when your dog injured their ACL, but with continued exercise, mild symptoms will become more pronounced and painful for your dog.
What are the signs that my dog has injured their ACL?
Dogs with ACL injuries are unable to walk normally and are in pain. If your dog has injured their ACL, you will notice that they are limping in its hind legs, have stiffness after exercise, and have difficulty rising off the floor or jumping.
How are ACL injuries in dogs treated?
If you suspect that your dog has an injured ACL it is important to see a vet to have the condition diagnosed and treated.
The tibia (lower leg bone) slides forward about the femur if your dog's ACL is torn or injured (thigh bone). This movement is known as a 'positive drawer sign,' and it causes knee instability, which can lead to cartilage and bone damage, as well as osteoarthritis.
Surgical treatments for ACL injuries in dogs include:
Extracapsular Lateral Suture Stabilization - ELSS / ECLS
This surgery for a torn ACL in dogs works by counteracting 'tibial thrust' (the sliding forward of the dog's tibia) with a specifically placed suture.
The transmission of weight up the tibia and across the knee causes the tibia to "thrust" forward relative to the femur. The forward thrust movement occurs because the top of the tibia is sloped, and the dog's injured ACL, which should be able to oppose the forward force, is no longer able to do so.
Extracapsular Lateral Suture Stabilization corrects tibia thrust by “anchoring” the tibia to the femur with a surgically placed suture. The suture pulls the joint tight and helps to stabilize the knee, preventing the front-to-back sliding of the femur and tibia while the ACL heals and the muscles surrounding the knee strengthen.
The suture must stay intact for 8-12 weeks for the ACL injury to heal. The suture will then begin to loosen or even break.
This surgery is relatively quick and uncomplicated with a success rate in smaller dogs. It can also be less expensive than other methods for repairing a torn ACL in dogs. Long-term success varies in dogs of different sizes and activity levels.
Tibial Plateau Leveling Osteotomy - TPLO
Another surgical option for treating your dog's injured ACL is the tibial plateau leveling osteotomy (TPLO). This surgery is more complex than the ELSS and aims to reduce the amount of forward movement during the dog's stride without the help of the ACL (CCL).
In this procedure, a complete cut through the top of the tibia is made (the tibial plateau). After that, the tibial plateau is rotated to change its angle, and a metal plate is placed to stabilize the cut bone as it heals. Over several months, the tibia will gradually heal and strengthen.
Full recovery from TPLO surgery will take several months however some improvement can be seen within just days of surgery. It is essential to follow your vet's instructions after your dog's TPLO surgery, and restrict your dog's activities to allow the bone to heal properly.
The long-term prognosis is good for TPLO treatment in dogs, and re-injury is uncommon. The stabilization plate does not need to be removed from your dog's leg unless it begins to cause problems.
Tibial Tuberosity Advancement - TTA
Tibial Tuberosity Advancement surgery is similar to TPLO but may be slightly less invasive than TPLO. Recovery from TTA appears to be quicker than recovery from TPLO in many dogs.
The front part of the tibia is cut and separated from the rest of the bone during TTA surgery. The front section of the tibia is then moved forward and up by screwing a special orthopedic spacer into the space between the two sections of the tibia. The patellar ligament, which runs along the front of the knee, is moved into better alignment as a result, which helps to prevent much of the abnormal sliding movement. After this procedure is completed, a bone plate will be attached to keep the front section of the tibia in place.
TTA surgery is typically performed in dogs with a steep tibial plateau (angle of the top section of the tibia). Your vet will evaluate your dog's knee geometry to determine which ACL treatment surgery is best for your dog.
How long does it take for dogs to recover from ACL surgery?
All dogs are different and some dogs will recover more quickly than others following ACL surgery. Nonetheless, recovery from ACL surgery is always a long process!
Your dog may be able to walk as soon as 24 hours following surgery, however full recovery and a return to normal activities will take 12 - 16 weeks or maybe longer.
It is essential to follow your vet's instructions and to pay attention to your dog's healing progress. Never force your dog to do exercises if they resist as this can lead to re-injuring the leg.