How and Why Does the TPLO Work?
The canine stifle is supported by a variety of ligaments. The cranial cruciate ligament is the most frequently damaged. The cranial cruciate ligament prevents the tibia (shin bone) from displacing forward. Unlike the human knee, the canine tibia slopes backwards. This results in a force called Cranial Tibial Thrust. Cranial Tibial Thrust is produced as the dog walks, producing a forward force on the top portion of the tibia. In the dog knee, forward translation of the tibia is counteracted by the cranial cruciate ligament as well as a balance between the hamstring and quadriceps muscle groups. Once the cranial cruciate ligament becomes damaged or is completely torn (A), there is an imbalance within the knee. Due to the cranial tibial thrust, this results in forward motion of the tibia. In addition, if the ligament becomes partially torn, the repeated strain results in an eventual complete tear in most dogs. With either partial or complete tears, the stifle becomes progressively unstabl
