Cruciate Surgical Repair

This is perhaps the most common dog injury we see. Occasionally cats will also rupture their cruciate ligament. The cruciate ligament is a tough band of tissue that holds the femur and the tibia together, the knee joint. When torn, the knee becomes unstable and the animal can become quite lame.

There are 2 main types of surgery that we perform for a ruptured cruciate ligament. The first is called the D'Angelis technique, the second is called a tibial wedge osteotomy.

1)D'angelis technique: With this technique we basically replace the ruptured ligament with a nylon prosthesis which mimics the action of the old ruptured cruciate ligament. The knee joint is actually opened and inspected for 2 reasons. Firstly we remove the remnants of the old ligament which can cause irritation and pain if left. More importantly we are looking to identify and remove any damaged meniscus. The meniscus is a band of cartilage that cushions the joint. When the joint has excessive movement after a ruture, the menisci can often become torn and damaged. The longer surgical correction of a ruptured cruciate is left, the greater is the potential for damage of this important cartilage.

Once cleaned up the joint capsule is closed, then the false ligament is placed. This new ligament is fixed around the back of the fabella, a small bone that sits behind the end of the femur. The ligament is then threaded under the patella ligament and comes back through a hole that we drill in the tibial crest, the prominent bony part of the top of the tibia. The two ends of the ligament can then be either tied in a knot or secured via 2 metallic “crimps” that are clamped down on the false ligament. We use the crimp method in our surgeries as they tend to have greater knot holding ability.

2)Tibial Wedge Osteotomy: This is a specialised procedure whereby the angle of the knee is straightened by taking a wedge of bone from the tibia and re-aligning the tibia to be straight. Effectively we are “breaking” the tibia in two via removing a wedge of bone. This is then plated, just like a broken bone. The great advantage of this procedure is that patients recover much faster, long term they do better and develop less arthritis, and are less chance than the D'Angelis technique to break down and not work. The disadvantage is cost, and if complications do occur from surgery they can be potentially more serious. This is the preferred option for larger dogs.

n deciding which of the above procedures to do many things need to be taken into consideration. The following is a brief summary of the advantages and disadvantages of each technique.

D'Angelis technique:

Advantages:

• Cheaper
• Less chance of serious complications
• If not successful can still go to the Tibial Wedge Osteotomy technique
• Still a very good chance of a very good result, even in large dogs. (Success is about 85-90% in large dogs and greater than 95% in small dogs)

Disadvantages:

• Greater chance of not working well (10-15% in large dogs, 5% in small dogs of not getting a great result)
• Longer recovery period
• More chance of a more arthritic knee long term

Tibial Wedge Osteotomy technique:

Advantages:

• Much shorter recovery period
• Better result via less arthritis long term
• Greater chance of successful result

Disadvantages:

• Cost
• If complications do occur, they can be more severe (such as non union of fracture repair)