What is a Cranial Cruciate Ligament Tear in Dogs?
The Cranial Cruciate Ligament, known as the CCL, is a connective tissue found in the knee of the dog that stabilizes the lower leg to the upper leg. The ligament connects the tibia, the bone beneath the knee, to the femur, the bone above. There are a number of CCL injuries that can occur in dogs. However, tears of the CCL are the most commonly observed.
What Causes a Cranial Cruciate Ligament Tear in Dogs?
CCL tears most commonly occur when the excessive internal rotation of the tibia takes place when the joint is partially flexed. Typically this is a result of exercise or running. One of the most common occurrences is when the dog is running and suddenly changes direction. This places the majority of the dog’s body weight on the knee joint, and excessive rotational force is placed on the cruciate ligament. The injury leads to the knee joint becoming unstable.
Who's at Risk of Developing a Cranial Cruciate Ligament Tear in Dogs?
There are a number of factors that may contribute to a dog being at higher risk of developing a CCL injury:
Breed Type: Certain breeds are more prone to CCL injuries, including Labrador retrievers, Newfoundlands, German shepherds, rottweilers, and Golden retrievers.
Obesity: Overweight and obese dogs are four times more likely to tear or rupture their CCL than dogs at a healthy weight. Obesity can play a major role in CCL injuries. The extra weight causes additional strain on the dog’s joints and muscles, making the ligaments more prone to wear and tear.
Weekend Warriors: “Weekend warriors” are those dogs who don’t necessarily exercise on a regular basis, but partake in occasional strenuous exercise.
Previous Injury: Studies have shown that dogs who injure the CCL in one leg have a 50% greater chance of injuring the other side. This is because the dog will compensate and use the other leg more. More strain placed on the good side causes a risk of tearing or rupturing as well.
What Are The Symptoms of a Cranial Cruciate Ligament Tear?
Oftentimes, symptoms of a CCL tear come on gradually and will progressively worsen over a long period of time. However, in some incidents, there may be no obvious symptoms until the ligament actually ruptures.
Symptoms of CCL injuries in dogs include:
- Lameness or limping
- Favoring one leg
- Stiffness after exercise
- Swelling around the knee
- Difficulty lying down or getting up
- Pain or tenderness near the injured knee
How Can a Cranial Cruciate Ligament Tear Be Prevented?
There are a number of measures that can be taken to reduce a CCL tear from occurring in your dog:
- Maintain a healthy weight in your dog
- Provide proper warm-up for your dog before vigorous exercise
- Avoid “weekend warrior syndrome” – keep the amount of exercise your dog receives relatively consistent
- Provide the proper nutrients and vitamins needed to support joint health (ex. Omega-3 and healthy oils)
How is a Cranial Cruciate Ligament Tear Diagnosed?
A physical examination is necessary to diagnose a CCL tear. During your dog’s exam, your veterinarian will assess the affected leg by holding the femur in place while moving the tibia out. If it moves in a manner that can be compared to opening a drawer, the CCL is injured.
In addition to the physical exam, your veterinarian or orthopedic surgeon will order x-rays to assess the severity of the CCL injury and if there is fluid present in the joint.
What Is The Treatment For a Cranial Cruciate Ligament Tear?
Surgery is typically recommended for dogs with a CCL injury. However, this is on a case-by-case basis. Dogs weighing over 22 pounds usually require surgery in order to stabilize the knee. Smaller dogs weighing less than 22 pounds, may be able to heal without surgical intervention if severe restrictions are taken.
CCL surgery is very common and compared to that of an ACL surgery in a human. CCL repair surgery generally begins with an examination of the inside of the dog’s knee. When damaged or torn portions of the CCL are identified, they are removed during the procedure. There are a number of surgical methods that can be used to repair the injured CCL. There are four common surgical techniques executed to repair the CCL. These four techniques are Extracapsular Lateral Suture Stabilization, TightRope Technique, Tibial Plateau Leveling Osteotomy, and Tibial Tuberosity Advancement. Your veterinarian will discuss the pros and cons of each CCL surgery option and guide you and your dog in the right direction.