Tibial Tuberosity Advancement (TTA) system

What is TTA surgery?

TTA stands for Tibial Tuberosity Advancement. It is a surgical procedure used to treat a torn cruciate ligament in the cranial (or anterior) part of the knee in dogs. It involves cutting the top of the tibia (shin bone), moving it forward and stabilizing it in its new position in one of several ways.

How is TTA surgery performed?

After a rupture of the cranial cruciate ligament, the knee (knee joint) becomes unstable. This instability causes the tibia (shin bone) to move forward relative to the thigh bone (femur) when the dog is bearing weight on the limb. Choking feels like "giving way," which can cause the dog to appear severely lame.

One reason the tibia moves forward with weight is that the top of the bone (called the tibial plateau) is not perpendicular (90 degrees) to the tendon (patellar tendon) that connects the kneecap (patella) to the tibial plateau.

The purpose of the TTA surgery is to bring the tibial plateau perpendicular to the patellar tendon, thus preventing the tibia from moving forward. Although the ligament has been ruptured and not directly repaired, the knee is stable for the dog during weight bearing.

Does my dog need TTA?

Tibial tuberosity advancement surgery is only applicable to dogs where the surgical benefits outweigh the possible risks and the alternative treatment is less successful. It is mainly carried out in medium and large dogs.

Candidates for TTA surgery are dogs with ruptured cruciate ligaments, which have persistent claudication and asphyxiated joint instability. Puppies and dogs with double ligament rupture (bilateral disease) are particularly good candidates.

What does TTA involve?

Dogs need to be carefully evaluated to see if they need TTA surgery. After the initial examination, additional palpation may be required under sedation or mild anesthesia. This can detect more subtle knee instability, as occurs with a partial rupture of the cruciate ligament.

A very specific X-ray examination of the knee and tibia is required. The presence and severity of osteoarthritis can be assessed, and the angle of the top of the tibia (tibial plateau) can be measured. This can be planned before surgery. You can evaluate the location of the incision on the bone, the amount of bone that needs to move forward, and the size of the implant that stabilizes the bone in the new location. Fluid (synovial fluid) samples may need to be taken from the knee and sent to the laboratory for analysis.

The operation can be performed on the same day of the investigation or on a different day. Antibiotics and analgesics are used during anesthesia, and the limbs are clamped from the hip level to the hock joint (ankle). Before performing TTA, make a small incision or incision on the knee joint to check the structure. Many dogs with ruptured cruciate ligaments of the skull tear cartilage (meniscus). The damaged portion of the cartilage needs to be removed. At the same time, the residual part of the broken ligament can be trimmed.

X-rays were performed at the end of the procedure to assess the new angle of the top of the tibia (tibial plateau) relative to the patellar tendon and to check the position of the implant. Light bandages are sometimes used. Most dogs can go home the day after surgery.

Aftercare

Post-operative care after TTA surgery is very important and recovery can take several months. A course of pain medication and antibiotics will be prescribed when your pet comes home. If the dog tends to lick the wound excessively, a plastic Elizabethan collar may be necessary. It is important to see a veterinarian within the first two weeks to examine the wound and remove all sutures.

Movement must be very restricted for the first few weeks until the soft tissues and cut bones have healed, mainly for toileting during this phase. It must be tied to a leash or harness to prevent strenuous movement, such as chasing a cat or squirrel. At other times, it is necessary to confine it to an enclosure or a small room in the house in order to avoid jumping and climbing. After a few weeks, the amount of exercise can be gradually increased in a controlled manner (still staying ahead). Hydrotherapy may be recommended.

An examination is required six to eight weeks after surgery. The extremities and knee (knee) function are checked at this time. X-rays are obtained to assess the healing of the osteotomy (osteotomy). Depending on the progress, advice is given about increasing exercise. Depending on the circumstances, further clinical and radiological examinations may be required.

Risks and complications

TTA surgery is associated with potential complications, including infection, implant loosening, and fracture. A small percentage of dogs that do not have injured cartilage at the time of TTA surgery continue to tear it at a later date. In such cases, lameness usually worsens suddenly and a second surgery (lock-hole surgery or arthroscopic surgery) is required to remove the torn pieces of cartilage. However, despite the possibility of complications, knee pain is reduced and limb function improves significantly in most patients who choose to undergo TTA surgery.