TTA: Tibial Tuberosity Advancement
TTA is used to manage the cranial cruciate deficient stifle in dogs. This procedure modifies the geometry of the stifle (knee) rather than attempts to repair the deficient function of the ligament
The shear forces of the tibia (shin bone) and the femur (thigh bone) appear to be responsible for excessive loading (pressure) on the cranial cruciate ligament (CCL) during weight bearing, leading to partial or complete rupture. TTA advances the tibial tuberosity to neutralize the shear force in the stifle. Advantages of this technique appear to be decreased lameness after surgery and minimal complications that are not usually catastophic when they occur.
For this procedure, pre-operative x-rays are taken with the leg at 135 degrees, measurements are taken, and an appropriate plate and spacer are selected based on the correction needed. During surgery, the front of the tibia is cut, advanced the appropriate distance, a spacer is placed to maintain that spacing, and the space is filled with cancellous bone to promote healing. A special plate is applied to maintain the advancement and support the bone while healing. During surgery, the joint is opened to inspect for and correct damage to the meniscal cartilages. A meniscal release is also done at that time.
Post Operative Care
The post operative management is extremely important to the healing of this or any CCL surgery. For 8 weeks the patient must be maintained restricted and on a leash. When dogs have this surgery, they usually start feeling very good a few days after the surgery and want to start being active again. We often suggest support of the back legs with a sling to prevent falling and injury when leash walked. At 4 weeks post operative, walking without support may occur and can begin a short walk as long as the patient is comfortable.
An X-ray of the stifle is done at 8 weeks post operative to verify healing. When healed, the dog may begin some exercise that can gradually increase over time. This should be done slowly to prevent stress on the patellar ligament.