Tibial Plateau Leveling Osteotomy (TPLO)

“TPLO” stands for tibial plateau leveling osteotomy – one of several techniques available for treating injury to the cranial cruciate ligament in dogs (equivalent to the “anterior cruciate ligament” of humans) which is found in the knee. This ligament is one of 2 cruciate ligaments which lie within the ‘knee’ joint (stifle), attaching the femur (thigh bone) to the tibia (calf bone) providing stabilization. The stifle is a complex joint, relying on a variety of anatomical structures in order to function normally (and pain-free).

Dogs, especially larger breeds, often injure the cranial cruciate ligament (CCL) resulting in an unstable ‘knee’, resulting in pain. You may notice a slight limp which worsens with exercise, reluctance to exercise or jump, or sudden lameness following activity. Your pet may sit with the limb splayed out to the side. Injury to the cranial cruciate ligament can be a slow process, or occur suddenly; even partial tear of this ligament can cause pain and instability but a complete rupture often causes unwillingness to stand on that leg.

Will this happen to my dog? Conformation of canines and the angle of the joint puts excess strain on this ligament, often causing slow degradation over time. Some breeds are more susceptible than others. Although injury to the cranial cruciate ligament can occur in any breed, sex or age of dog, several factors such as obesity significantly increase the risk. There is no way to prevent this injury from occurring; however exercise helps to keep weight down and muscle strength up, possibly decreasing likelihood of injuries, illness and osteoarthritis.

How will my veterinarian diagnose this condition? Your veterinarian can make a presumptive diagnosis of a damaged CCL based on palpating (feeling) the knee as well as testing its stability. The tibia and femur which form the “stifle”, or knee, are normally stable, allowing flexion and extension; however when the CCL is damaged, the femur is free to move forward in relationship to the tibia, demonstrating “cranial drawer” motion, a strong indicator of a damaged CCL.

Radiographs (x-rays) are also a valuable diagnostic tool to confirm that there aren’t additional problems present causing your pet’s clinical signs. Although soft tissues such as ligaments are not visible on x-rays, other changes to the joint may be seen following injury to the stifle such as joint effusion, fracture or arthritis.

Does the surgery cure my dog of a ruptured CCL? There is no cure for injury or rupture of the CCL. The goal in treatment of TPLO surgery is stabilization of the stifle and pain control to keep your pet comfortable. There are many surgical options which attempt to stabilize this joint, including the TPLO, TTA (tibial tuberosity advancement), extracapsular and intracapsular techniques – some of which attempt to mimic the action of the no longer functioning CCL. Which technique will work best for you and your pet is determined by your veterinarian based on body weight, breed, activity, and other factors.

Medical treatment involves controlling the pain with anti-inflammatories such as non-steroidal anti-inflammatories (NSAID’s) and opioid-like medications such as tramadol.

What will happen to my dog’s condition should I decide no to surgery? Although the canine stifle is difficult to stabilize by using a cast, splint or bandage, over time the body will attempt to stabilize the injured knee by production of scar tissue in and around the joint. Arthritis will also develop over time. To delay these changes such as degenerative joint disease, the joint should be treated as soon as possible after the injury if determined to be the best course of action by you and your veterinarian.

What happens after surgery? The recovery process following the TPLO is crucial, involving 2-3 months of restricted activity. Physical therapy can be of benefit to maintain strength and expedite recovery during this time. X-rays are taken at the end of the recovery period to ensure adequate bone healing before removing those exercise restrictions. Most dogs return to the same or similar level of activity prior to the injury; however, as with any surgery, there are risks, including infection, implant rejection/failure, bone fracture, etc.

If you think your pet may have an injury or possibly a CCL injury, please give us a call as soon as possible to discuss your and your pet’s options for care at Encina Veterinary Hospital with Board Certified Veterinary Surgeon, Dr. Carl Koehler: (925) 937-5000

Cindi Hillemeyer, DVM