TPLO, or tibial-plateau-leveling osteotomy, is a surgery performed on dogs to stabilize the stifle joint (knee) after ruptures of the cranial cruciate ligament (analogous to the anterior cruciate ligament [ACL] in humans, and sometimes colloquially called the same).
In the vast majority of dogs, the cranial cruciate ligament (CrCL) ruptures as a result of long-term degeneration, whereby the fibres within the ligament weaken over time. We do not know the precise cause of this, but genetic factors are probably most important.
In a TPLO procedure, the tibial plateau, the portion of the tibia adjoining the stifle, is cut and rotated so that its slope changes to approximately 5 degrees from the horizontal plane. This prevents the femur from sliding down the slope of the tibial plateau when the dog puts weight on its knee. Thus surgery generally results in faster recovery times compared to other procedures to stabilize the knee. Most dogs (over 90%) are expected to regain a very active and athletic lifestyle with no post-operative complications and without the need for any long-term pain relieving medication.
TPLO is the preferred and most recommended surgical repair for CrCL (ACL) injuries especially for active large breed dogs.
