Cranial Cruciate Ligament Injury

Cranial cruciate ligament injury in dogs is one of the most common causes of hind leg lameness presented to veterinarians.

The cranial cruciate ligament stabilizes the stifle during weight bearing and movement. When the cranial cruciate ligament is ruptured it results in instability of the stifle joint, called cranial tibial thrust.


Cranial Tibial Thrust

  • When the cruciate ligament ruptures, the slope of the tibial plateau - along with the forces exerted by the muscles in the leg - cause the femur bone to slide downward on the top of the tibia bone, called the tibial plateau. This in essence causes the tibia to thrust forward with each weight-bearing stride, and is called cranial tibial thrust.
  • This thrusting results in excessive wear of the cartilage of the joint, and stretches the tissues which surround the joint. Cranial tibial thrust can also tear the menisci which are protective cushions sitting over the cartilage.
  • Prolonged instability in the stifle with time will lead to arthritic changes in the stifle.
  • Conservative treatment (non surgical) of cranial cruciate injuries in dogs is generally unsuccessful. This is because the cranial cruciate ligament deficient stifle can no longer prevent this cranial tibial thrust, hence surgical repair is the preferred treatment. There are numerous surgical techniques that have been developed to correct ruptured cranial cruciate ligaments in dogs.



These techniques include:

Tibial Plateau Leveling Osteotomy (TPLO)

The Tibial Plateau Leveling Osteotomy (TPLO) is an orthopaedic surgical procedure and is considered worldwide to be the Gold Standard surgical procedure in treating cruciate ligament injury. It involves making a curved cut on top of the tibia, which is then rotated in order to level the tibial plateau slope.

A specific bone plate and screws are used to hold the rotated bone in place, so it can heal in this new position.

By leveling your dogs tibial slope, we eliminate the tibial thrust forces acting on your dog’s knee. This will prevent further damage to the dog’s cartilage and meniscus, which aims to slow the progression of osteoarthritis.

The TPLO surgery is considered an advanced surgical technique. Bass Hill Veterinary Hospital is able to provide this technique after receiving formal training from veterinary specialists.




Tibial Tuberosity Advancement (TTA)

The Tibial Tuberosity Advancement (TTA) involves cutting the tibial tuberosity and advancing it forward so that the patella tendon is perpendicular to the slope of the tibial plateau. The tibial tuberosity is held in its new position by a titanium plate, cage and a bone graft placed in the bone gap to stimulate bone healing.

The repositioning of the Tibial Tuberosity eliminates tibial thrust and stabilizes the joint, which aims to slow the progression of osteoarthritis.














Triple Tibial Osteotomy (TTO)

The Triple Tibial Osteotomy involves removing a small horizontal wedge of bone from the tibia to level the tibial plateau and in closing this wedge down the tibial tuberosity is advanced slightly. The TTO procedure essentially is a hybrid of the TTA and TPLO surgery. It uses the theories of both procedures to eliminate tibial thrust and prevent to progression of osteoarthritis.

We offer this procedure when surgical candidates are more suited to this hybrid procedure over routine surgical procedures.




Tibial Wedge Osteotomy (TWO)

The Tibial Wedge Osteotomy involves removing a horizontal wedge of bone to level the tibial plateau to eliminate the tibial thrust. This procedure has also been offered at Bass Hill Veterinary Hospital in dogs with steep tibial plateaus where other procedures are unsuitable or to repair patella luxation at the same time.


De Angelis Suture

This involves the placement of a nylon prosthetic suture to mimic the action of the cruciate ligament and stabilize the stifle. The suture is passed through a bone tunnel in the front of the tibia coursing around the back of the femur bone and tightened with steel crimps. The nylon suture allows normal passive movement of the knee but stabilises the joint from forward movement. It is a surgery that has traditionally been most applicable for smaller patients.





The Modified Maquet Procedure

MMP uses a wedge-shaped implant of titanium OrthoFoam™ which both defines the degree of advancement of the tibial tuberosity and holds the bone in its new place while the bony ingrowth that provides permanent biomechanically robust fixation, develops.

The Orthofoam wedge provides a robust early fixation without the need for support bandages or a lengthy period of rest. The potentially disruptive forces that act to displace the distal end of the tibial tuberosity cranially following advancement are controlled using wither wire tension band, a titanium staple or a plate and screws.


If you suspect your dog has ruptured its cruciate ligament, please phone Bass Hill Veterinary Hospital  on 02 9724 1927 to make an appointment.