Repair of Cranial Cruciate Ligament Rupture Via Tibial Tuberosity Advancement (TTA)

When a dog tears the CCL in their knee (stifle), there are various procedures and implants to be used in the repair. In a prior article CCL Knee Surgery and Rehabilitation, we discussed the Tightrope implant option. Having personal experience with both the Tightrope and now the TTA procedure, following are details on Tibial Tuberosity Advancement.

The knee structure in a dog versus a human is similar in the fact that the critical stabilizing component is the cruciate ligament (known as the anterior cruciate ligament or ACL in the knee in humans and cranial cruciate ligament or CCL in the stifle in dogs). The main functions of the CCL is to prevent cranial displacement of the tibia, prevent hyperextension of the knee, and prevent internal rotation of the tibia and forward thrusting motion during weight bearing to avert hyperextension of the knee. A CCL injury occurs when the joint is rotated unexpectedly or overextended. Other issues such as obesity or repeated stresses can also damage this joint causing changes over time and bring about arthritis.

When the CCL is damaged, either an acute rupture, chronic rupture, or partial tear, often the meniscus which is a cushion inside the joint is often damaged and torn. A tear in the meniscus can cause even more pain to the dog. With a meniscus tear a clicking or popping sound can be heard when walking. For CCL damage, the dog will experience pain and will either favor the leg or not put any weight bearing on it. The knee will also likely swell and range of motion may be compromised. If the dog only has a partial tear, the signs are more difficult to see. The dog may appear to move slower, limp, appear stiff, when sitting holds leg out to the side, has difficulty rising, but shows improvement after rest. Over time, the CCL will get worse resulting in an unstable, painful knee with added arthritic conditions in the joint.

What is TTA? It is one of the techniques used to stabilize the knee in a dog. This surgical technique was developed in Switzerland and available since 2004. The surgeon will fracture the bone by making a cut in the tibia along the front, moving the bone out and stabilizing with a titanium plate and screws. This will make the dog's leg slightly wider than their other one. Titanium is being used in an effort to help in cold weather areas. When stainless steel was used, there were issues found when the weather became cold, dogs would experience discomfort from the steel. Using titanium appears to eliminate that issue. By moving the tibia forward, the force of weight bearing has changed by changing the angle of the ligament. This implant is held in place by screws and is permanent.

CCL rupture is one of the most common orthopedic issues seen in dogs and CCL repair is the most common orthopedic surgery performed by veterinary surgeons. By researching options, you and your vet will make the best decision for your dog that may be experiencing this problem. There will be a long road to recovery but following the strict advice of the surgeon, keeping the dog on lead for the eight week recovery period, and limited exercise, proper healing should occur with your dog being allowed to resume normal activity.