A Cranial Cruciate Ligament (CCL) injury is one of the most common orthopedic problems in dogs and is the most common reason for hind limb lameness in dogs. In people the CCL is called the Anterior Cruciate Ligament (ACL).
The CCL attaches the back of the femur to the front of the tibia and is responsible for stabilizing the knee joint. Dogs are susceptible to CCL injuries due to the natural slope of the knee that causes instability. CCL injuries occur in dogs of all breeds, ages, and sizes but they are especially common in Labrador Retrievers, Newfoundlands, Rottweilers, and Pit Bulls.
A CCL can be partially or completely torn. A partial CCL tear can cause symptoms that resolve over time, but the ligament can NOT repair itself. Eventually a partial CCL tear will eventually lead to a complete tear. The longer a CCL rupture is present the more arthritis forms and therefore, the pain and lameness increase. The majority of dogs who injure their CCL will also injure their meniscus that is the cartilage-like structure that is responsible for shock absorption and weight bearing. Due to the risk of degenerative changes it is advisable to seek veterinary care as early as possible.
Symptoms of a CCL injury include:
- Lameness in a hind limb
- Non-weight bearing on a hind limb
- Trouble rising from sitting or lying position
- Decreased activity
- Hopping on three legs
- Sitting with legs out to the side instead of under the body
- Loss of muscle mass
Diagnosing a CCL injury can be as simple as palpating the knee and observing the dog as it walks. X-rays are usually taken to confirm the presence of fluid in the joint which occurs with injury, the degree of arthritis, and to rule out any other injuries such as a fracture or dislocation. The CCL and meniscus cannot be seen on x-rays.
Two important steps should be taken when treating a CCL injury:
- Surgical repair
- Medical management of arthritis
Many surgeons consider the TPLO (Tibial Plateau Leveling Osteotomy) surgery to be the gold standard for CCL injuries.