TTA stands for Tibial Tuberosity Advancement. It is a procedure for treatment of cranial cruciate ligament rupture. This procedure was developed in Switzerland in 2002/2003 and is now available worldwide. We are thrilled to bring this procedure to the North Hills area and be able to offer pet owners an alternative to current techniques.
TTA works by altering the architecture of the knee in a manner that allows natural weight bearing forces to stabilize the knee making the cruciate ligament no longer necessary to have stability. This becomes evident when we take a closer look at the canine knee.
Background
The normal dog bears weight and walks with the knee in a slightly flexed position (approximately 135 degrees). If we look at the interior of the knee we can see that the cranial cruciate ligament attaches the femur (upper thigh bone) to the tibia (lower shin bone). The cranial cruciate ligament’s normal function is to stop the tibia from being pushed forward of the femur during ambulation and weight bearing. The top of the tibia as outlined below has a naturally rounded shape. When the animal applies weight across the knee the natural action is for the femur to move toward the back along the tibial plateau (top of the itbia) and push the tibia forward. This in turn applies shear forces to the cranial cruciate ligament and when intact the cruciate ligament stops this motion and the knee is stabilized.
Fig.1If we look a little closer at the forces acting on the cruciate ligament we find that weight bearing forces are parallel to the patellar (knee cap) tendon. This is outlined in the diagram figure 2 below. The diagram on the right below (fig. 3)shows what happens when the cranial cruciate ligament is no longer intact and the dog attempts to bear weight.
Fig. 3Tibial tuberosity advancement allows us to stop cranial tibial thrust without having an intact cranial cruciate ligament. As we mentioned earlier, weight bearing forces at the knee are parallel to the patellar tendon. Therefore, if we change the angle of the patellar tendon we can change the forces acting on the knee. The diagrams on the right show how we have changed these forces that act on the knee and how we can provide stabilization of cranial tibial thrust without an intact cruciate ligament.
Ruger ruptured her right cranial cruciate ligament in August 2008. A TTA repair was performed and she responded very well. 7 months later in March 2009 she ruptured the left cranial cruciate ligament. This knee was also repaired via tibial tuberosity advancement. The first video below shows her at 3 days post-operatively. The second video is at 6 weeks post-operatively.
after her operation
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