Understanding cruciate ligament injury and TTA surgery
Drs. Romain and Peuser have had special surgery training for a procedure called Tibial Tuberosity Advancement, or TTA. This surgery is performed on dogs who have sustained a cranial cruciate ligament injury (the “ACL” in people). Recently, we performed bilateral TTA on a beagle named Milo. This means both of Milo’s cruciate ligaments were injured, so he had the procedure done on both stifles at the same time.
The cranial cruciate ligament plays a crucial role in making sure the tibia bone does not slip out and forward from the stifle joint. ACL rupture in dogs is one of the most common causes of hindlimb lameness, and it almost always requires surgical correction.
Veterinarians can diagnose ACL rupture in dogs with a physical exam and radiographs (x-rays). While stabilizing the femur in one hand, the other hand manipulates the tibia, and if the tibia slides forward like a drawer, this is indicative of cruciate ligament injury.
The goal of TTA surgery is to limit this tibial thrust, which can be quite painful. Surgery begins by inspecting the stifle joint and removing the damaged cruciate ligament. The goal is to transfer the load of the joint from the patellar ligament to the quadriceps muscle. To achieve this, the veterinary surgeon makes a cut into the tibial tuberosity (bone). The tibial tuberosity is advanced into a position perpendicular to the tibial plateau, thus removing the load from the ruptured cruciate ligament. To keep this newly positioned tibial tuberosity in place, a titanium implant is secured to the bone, and a spacer and bone graft material is placed into the cleft between the bones. This helps stabilize the joint.
Post-operative care involves:
- Limited exercise
- Restriction of play
- Care of the surgical site
- Administration of medications
- Suture removal
Follow-up radiographs are usually taken 2 months after the surgery to ensure proper healing.
Milo’s surgery included an epidural to numb his hind limbs for 12-24 hours post-op, and he received a continuous IV infusion of hydromorphone, lidocaine, and ketamine (referred to as an HLK CRI in vet talk) for the next 48 hours to help control pain and provide optimum pain management.