Cranial Curciate Ligament Injury

Important Anatomy

The stifle (knee) is a complex joint consisting of the femur (thigh bone), the tibia (shin bone) and the patella (kneecap).  Cartilage ‘cushions’ called the medial and lateral meniscus fit between the femur and tibia.  The two ligaments that cross inside the knee joint are called the cranial (front) and caudal (back) cruciate ligament.  The cranial cruciate ligament (CCL) is one of the most important stabilizers of the stifle.

Understanding Disease of the CCL

Rupture of the CCL is a common orthopedic injury affecting dogs of all ages.  CCL-injuries typically occur as a result of a slow deterioration of the ligament. They start out as partial tears with a subtle lameness. Over time the tear worsens and the stifle becomes more unstable and painful. This results in further inflammation and debilitating arthritis develops.  Unfortunately, many dogs that rupture one cruciate ligament frequently rupture the other at some point in their lifetime.

Diagnosing CCL Injury

Usually the disease starts as a sudden lameness,   which is often intermittent at first and then progresses to continuous lameness. Many dogs are more painful after exercise, shift weight off the affected leg, sit differently with a leg to the outside, and are less active. A tentative diagnosis is established by palpation of the stifle in conjunction with    X-rays (radiographs). Radiographs will not show the ligament itself but are useful in evaluating the amount of joint fluid, arthritis, and ruling out other diseases such as bone cancer. The diagnosis will be confirmed at the time of surgery by visualizing the tear of the CCL.  This can be done by the more traditional approach of opening the joint (arthrotomy), or with arthroscopy.   Arthroscopy is used almost exclusively at AMVS as a minimally invasive way to evaluate the inside of your dog’s stifle using a small videoscope (camera), achieving the most complete evaluation of meniscal and CCL-injuries.

                             

Treatment of CCL Injury

Tibial Plateau Leveling Osteotomy (TPLO)

The TPLO-procedure alters the physics or biomechanics of the stifle joint, eliminating the need for the CCL by reducing the downward slope of the tibia. This results in a stable knee without actually replacing the ligament itself. To achieve this, the top portion of the tibia is cut with a bone saw and rotated just below the joint surface. The bone is then stabilized in its new position using a bone plate.  TPLO has revolutionized the way veterinary surgeons treat CCL-injuries in dogs. The success rate of TPLO surgery is extremely high, with many dogs returning to normal or almost normal function. Because of the high clinical success, it has become the treatment of choice in large-breed and/or athletic dogs.

Tightrope Procedure

The Tightrope technique was developed to overcome the disadvantages of other surgical techniques like TTA, TPLO, and lateral suture. The TR is a fairly new technique that is based on replacing the cruciate ligament with a prosthetic ligament on the outside of the joint. This procedure uses FiberTape (a very strong suture material) and is theoretically superior to the lateral suture technique because it uses bone tunnels and toggles that are placed in isometric fashion (allowing normal range of motion). In contrast to TPLO/TTA, it is much less invasive and does not require a bone cut. The TR procedure has been compared to TPLO in a preliminary research study and found to have similar outcomes and complication rates as TPLO. However, no long-term data is available to date.

Lateral Fabellotibial Procedure

This method uses a suture that spans the joint and attempts to stabilize it while fibrous tissue forms.  The suture is passed around a small bone on the back side of the femur and through a hole drilled in the tibia. The anchor points for this suture are different than the anchor points of the original CCL which is likely the cause of the progression of arthritis and occasional residual lameness seen with this technique. For young, large and active patients, clinical outcomes appear to be more favorable with TPLO/TR procedures.

Tibial Tuberosity Advancement Procedure (TTA)

The TTA-procedure aims at achieving the same goal as the TPLO, but with a different approach (insertion of quadriceps muscle rather than rotation of shin bone). For more information on TTA, please ask your surgeon.

What to Expect After Surgery

Regardless of the chosen technique - it is extremely important to restrict exercise while the dog’s knee is healing.  In general, patients should have exercise restriction (no running, jumping, rough-housing or off leash activity) for 3 months after surgery.  Full activity is generally achieved 3-5 months after surgery.  In general, the recovery is faster with TPLO and TR than with the lateral suture technique.  While the TPLO or TTA procedures have the risk of implant failure, the TR or lateral suture procedures have the risk of suture loosening or failure of the suture (more so with the lateral suture).  Other possible complications include infection, meniscal injury or residual lameness. Physical therapy is an essential part of the recovery process to achieve optimal function.

 

Printable TPLO Flier

Printable Tightrope Flier

Printable TPLO General Guidelines & Exercise Restrictions

Printable CCL Injury Brochure

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