Tibial Plateau Leveling Osteotomy in Dogs – The TPLO
By Dr. Frank Coons
Injuries to the anterior or cranial cruciate ligament in the knee (or stifle) is widely accepted as the most common significant joint injury in the dog. Anatomically very similar to the same ligament in people, the function and biomechanics are significantly different in the quadruped. Ligaments attach bone to bone, and the anterior cruciate ligament or acl attaches the femur (thigh bone) to the tibia(shin) to prevent forward movement of the tibia relative to the femur, protect against excessive internal rotation and hyperextension.
Injuries to the acl in dogs run the gamut from young to old, small to large. Causes include trauma, obesity, conformation abnormalities, genetics or any combination of these. As opposed to the injury in man which is usually due to a single traumatic event (skiing, soccer, etc.), the dog may often have an insidious onset, minor trauma or multiple traumas leading up to clinical presentation. Many dogs will have periods of subtle lameness that seem to recur, or partially respond to rest and medication prior to diagnosis. Others will present more suddenly with no early signs of trouble. The diagnosis may be very obvious, but in some cases can be quite challenging. Because the causes can be varied, and include anatomic and genetic predispositions, eventual involvement of both knees is common.
The TPLO was developed in the early nineties by Dr. Barclay Slocum, and has become for many surgeons and institutions, the preferred method of treatment in medium and large dogs. The TPLO surgery takes advantage of the fact that the canine knee has a backward facing slope to the top of the tibia (tibial plateau). By making a very specific circular cut through the tibia below the knee, this slope can be rotated to level, preventing the sliding of the tibia forward that causes the instability, the pain and the ensuing arthritis. Once the alignment is corrected, the bone is stabilized with a specialized plate and screws. The bone will heal from the TPLO surgery procedure in 8-10 weeks, but total recovery is generally around four months.
As with any orthopedic surgery, including TPLO, careful attention to post operative physical therapy is critical to overall success. In addition, weight management, diet and long term lifestyle choices are crucial to achieving the best long-term result.
In summary, the TPLO procedure has proven to be a very valuable surgery in treating anterior cruciate ligament tears in many dogs, often with excellent long-term function and minimal arthritis. The TPLO procedure is major orthopedic surgery that requires special education and a team approach.
