If you have recently been told your dog needs ACL repair surgery, you are probably a bit confused as to which surgery is right for your pet. Injury to a dog’s ACL, also known as the cranial cruciate ligament (CCL), is the most common orthopedic injury found in large breed dogs today. A torn CCL may be the result of sudden acute trauma to the knee or “stifle joint,” or may develop slowly as in overweight dogs with progressive degenerative joint disease.
The most conventional surgical option is referred to as Extracapsular Stabilization or (ECR). Think of this surgery as replacing a rope. The ligaments inside a dog’s stifle joint crisscross, running through the joint. Once torn, the ligament is unable to support the function of the stifle joint. The ligament will never repair itself. The surgeon will use materials such as stainless steel wire to wrap around the lateral fabella and through a drilled hole in the tibial crest. This technique is performed outside the stifle joint, restraining abnormal motion. The ultimate goal is for the artificial ligament to provide the stability needed for the joint to function normally. Eventually, the wire will loosen slightly, muscles will strengthen and the development of scar tissue will help to stabilize the joint.
A second, more invasive surgery referred to as Tibial Plateau Leveling Osteotomy (TPLO) is thought to be a good alternative for larger dogs. This approach actually changes how the stifle joint functions, whereas the goal of ECR is to mimic the mechanics of the joint. In TPLO, a cut is made with a custom curved saw at the top of the tibia bone. The tibial plateau is then rotated along the curved osteotomy, so as to change the slope of the top of the tibia. The bones are held in place by a metal plate and screws, allowing the bone to heal. This technique eliminates the need for cranial cruciate ligaments by leveling the angle of the joint itself.
The TTA procedure or Tibial Tuberosity Advancement is considered less invasive than TPLO, and brings with it fewer complications. In TPLO, joint stability is achieved by rotating the tibial plateau. Conversely, in TTA, joint stability is achieved by repositioning the patellar tendon. This involves cutting the front part of the tibia bone and advancing this portion of bone forward in order to realign the patellar ligament. This eliminates the abnormal sliding movement within the stifle joint. A custom bone spacer, plate and screws are used to keep the bone in place, and a bone graft is placed into the gap in the tibia bone to stimulate healing.
The three surgical procedures listed above each come with their own set of risks and benefits. It is imperative that you discuss with your surgeon, the best option for your dog.