TPLO Surgery
TPLO surgery is one of the most common orthopedic surgeries for dogs.
TPLO Stands for Tibial Plateau Leveling Osteotomy
The cranial cruciate ligament (CCL) is a ligament in the knee that contributes a large amount of stability to the knee. The body relies on the CCL to prevent forward movement and internal rotation of the lower leg bone (tibia) as well as hyperextension of the knee. When the CCL is partially or completely torn, pain and instability result. A torn CCL will start a cascade leading to osteoarthritis.
Treatment consists of two steps:
"Cleaning Up"
Cleaning up the joint entails removing the torn remnants of the cranial cruciate ligament and addressing the meniscus. The meniscus is a fibrocartilage disc that sits between two bones in the knee (femur and tibia). The medial meniscus is at risk of being damaged when there is a cranial cruciate ligament tear. A torn meniscus is treated by removing the torn portion. If the meniscus is normal it can be released or left alone. Releasing the meniscus is performed by some surgeons to minimize the risk of future damage to it.
Stabilization
Stabilization is performed by changing the geometry in the knee. The top of the tibia is sloped. A torn cranial cruciate ligament allows the upper bone (femur) to slide down the slope. To prevent the “sliding” a curved bone cut is made in the tibia and the sloped portion is rotated to “level” or “flatten” out that surface. After leveling the slope the femur is no longer able to slide down the slope on the tibia. Once the rotation has been performed the cut bone is put back together in its new, level position with a bone plate and screws. The bone will then heal in its new position over the following 8-12 weeks. Once the bone has healed the bone plate and screws are no longer needed and could be removed if they ever caused any issues.
Recovery
Three months
Prognosis
Very good to excellent
(depends upon the amount of osteoarthritis present)
(depends upon the amount of osteoarthritis present)
Potential Risks:
Anesthetic risks are extremely low in healthy patients but must be understood and accepted in moving forward with any anesthetic event.
Bleeding and infection are risks associated with any surgery. Infection rates are reportedly around 5-8%. Over the last 6 years our TPLO infection rate has averaged 2%.
Risks associated with placing an implant (pin, screw, wire, plate, suture, etc.) in the body are very low. However, implants can loosen, migrate, become infected/rejected, and break. If this were to happen an assessment would need to be made to determine if further surgery or implant removal would be needed.
There is a 1% chance of a broken tibial tuberosity (front part of the lower leg bone).
Osteoarthritis forms anytime there are abnormal forces on a normal joint, or normal forces on an abnormal joint. Any pet that has a cranial cruciate ligament rupture has an “abnormal joint” and therefore will form osteoarthritis throughout life. However, correcting the instability in the knee will help to minimize future clinical problems resulting from osteoarthritis.
Injury to the meniscus is possible before and after surgery. Although damage to it after surgery is uncommon (~5%), it is painful and could require a second surgery to address it.
Pets that rupture the cranial cruciate ligament on one leg have a 30-40% chance of rupturing the cranial cruciate ligament on the opposite leg.