Cruciate Ligament Repair for Dogs

Knee Joint

• The knee joint is formed by three leg bones. The femur bone, the long bone that attaches at the hip, forms the top section of the knee. The tibia, the bone that spans the knee and ankle, forms the bottom section of the knee. The patella bone forms the kneecap. Connecting these three bones are ligaments, or fibrous bands of tissue. The two cruciate ligaments crisscross in the joint between the tibia and femur. The cranial cruciate ligament lies near the front of the leg, and the caudal cruciate ligament is near the back of the leg. These ligaments function to hold the tibia and femur in place and prevent them from sliding across one another.

Ruptured Cruciate Ligament

• A ruptured cruciate ligament describes a ligament that has been torn either by injury or degenerative disease. Certain breeds are at higher risk of cruciate ligament degeneration and are more prone to rupture. A dog with a ruptured cruciate ligament will present with a leg (usually rear) that is so painful that he will not put weight on it to walk. Cranial cruciate ligament rupture is the most common knee injury in dogs whereas caudal cruciate ligament ruptures are extremely rare.

Surgery

• Dogs under 30 pounds often do not require surgical intervention. Strict confinement, anti-inflammatory medications, and weight loss are often prescribed for these smaller dogs. Sixty-five percent of smaller dogs improve considerably within six months. Surgery may be recommended if no improvement is seen within six to eight weeks. Dogs heavier than 30 pounds almost always require surgery to correct the problem and prevent potential lifelong lameness. Only 20 percent of heavier dogs improve without surgery.

  There are three main surgical options to consider for cruciate ligament repair. The first option is called the lateral suture technique. This procedure uses synthetic suture material to recreate the torn ligament in dogs less than 70 to 80 pounds. The second option is called tibial plateau leveling osteotomy (TPLO). This surgery alters the shape of the tibia by cutting and reattaching portions of the bone with plates and screws. The result is a more stabilized knee joint. The third option is tibial tuberosity advancement (TTA), which also cuts and then reattaches a portion of the tibia bone to alter the joint mechanics.

Recovery

• After knee surgery is performed, a dog must be kept completely non-weight bearing for two weeks. The dog is then restricted to leash walking for a minimum of another six weeks to ensure complete healing. Exercise is gradually increased until the dog is allowed to return to normal activity levels approximately four months post-surgery. Physical therapy can also help speed recovery.

Prognosis

• The success rate for cruciate ligament surgical repair is higher than 85 percent. An overweight dog should return to his normal body weight to ensure optimal results. Degenerative joint disease can occur as the dog ages, and its severity is largely determined by the extent of the injury and the time lapse between the injury and surgery.