TTA (Tibial Tuberosity Advancement) surgery is a procedure used to treat cranial cruciate ligament rupture in dogs. It involves cutting the top of the shin bone and moving it forward to stabilize the knee joint. This surgery is commonly performed on dogs to treat hind limb lameness caused by cruciate ligament rupture. The procedure changes the shape of the knee so that the quadriceps muscle can help to stabilize the joint. This allows the dog to bear weight on the affected leg without feeling unstable.