The Animal Medical Hospital at Glenwood is proud to offer surgical options for Cranial Cruciate Ligament Disease (tears). The cranial cruciate ligament (CrCL) is one of the most important stabilizers inside the canine knee (stifle) joint, the middle joint in the back leg. In humans the CrCL is called the anterior cruciate ligament (ACL). We offer both TPLO surgery and extracapsular surgery, depending on which is better for the patient.
What is TPLO surgery?
Tibial Plateau Leveling Osteotomy (TPLO) is a surgical procedure used to treat cranial (or anterior) cruciate ligament rupture in the knee joints of dogs. It involves changing the angle of the top of the shin bone (the tibial plateau) by cutting the bone, rotating it, and stabilizing it in a new position with a plate and screws.
Cranial cruciate ligament rupture is the most common cause of hind limb lameness, pain, and subsequent knee arthritis in dogs. As a result, TPLO surgery is one of the most common orthopedic surgical procedures performed in dogs.
How does TPLO surgery work?
Following rupture of the cranial cruciate ligament, the knee (stifle) becomes unstable. When the dog puts weight on the limb the instability allows the shin bone (tibia) to move forward relative to the thigh bone (femur). The stifle feels as though it is ‘giving way’ and this can cause the dog to appear severely lame.
The reason the tibia moves forward with weight-bearing is that the top of the bone (called the tibial plateau) is not perpendicular (90 degrees) to the length (the axis) of the bone.
TPLO surgery aims to make the tibial plateau perpendicular to the long axis of the bone and prevent the shin bone from moving forward. The stifle then feels stable for the dog when weight-bearing, even though the ligament has been ruptured and has not been directly repaired.
Diagnosing complete tears of the CrCL is easily accomplished by a veterinarian using a combination of gait observations, physical examination findings, and radiography (X-rays). By contrast, partial CrCL tears may be more challenging to diagnose.
X-rays allow your veterinarian to:
- Confirm the presence of joint effusion (fluid accumulation in the joint, indicating that there is an abnormality present).
- Evaluate for the presence/degree of arthritis.
- Take measurements for surgical planning.
- Rule out concurrent disease conditions.
Does my dog need a TPLO?
Candidates for TPLO surgery are dogs with a ruptured cranial cruciate ligament that have persistent lameness and stifle joint instability. Young dogs and those with rupture of both of their ligaments (bilateral disease) are particularly good candidates.
Cruciate ligament disease and injuries can affect dogs of all breeds, sizes and age; however, TPLO surgery is primarily performed in medium, large and giant breed dogs.
Poor physical body condition and excessive body weight are risk factors for the development of CrCLD. Both factors can be influenced by pet owners. Consistent physical conditioning with regular activity and close monitoring of food intake to maintain a lean body mass is advisable.