Cranial Cruciate Ligament Injuries in Dogs

A Rottweiler walking through the grass.

If your pet collapses, is unable to walk or get up, or experiences severe trauma, these are considered “RED” – or true emergencies – on our Fast Track Triage system. We advise you to seek immediate veterinary care. Please call ahead of your arrival so the veterinary team knows to expect you!

If your pet is limping, has a small wound/laceration, or has a broken toenail, these are considered “YELLOW” – or semi-urgent cases – on our Fast Track Triage system. We recommend having your pet evaluated by your family veterinarian or local animal emergency hospital within 24 hours. Call ahead of your arrival so the veterinary team knows to expect you, and if your pet’s condition worsens, call the team back to inform them of the status change.

Damage to the cranial cruciate ligament is one of the most common orthopedic injuries we see in dogs. The cranial cruciate ligament (CCL, also known as ACL) is one of the major stabilizers of the knee joint. When the CCL is injured, it can lead to varying degrees of lameness in dogs, making it crucial for pet parents to recognize this type of injury and seek veterinary care if they notice any changes in their pet’s mobility.

A sad dog lying on the ground next to a soccer ball.

Causes

CCL injuries are common in young to middle-aged large breed dogs, but they can occur in dogs of any size. While less common, cats can also suffer from CCL injuries.

While trauma, like falling off the couch or jumping from the bed, can result in CCL injuries in pets, other variables also play a role. Genetics (with certain breeds like Labradors, German shepherds, Rottweilers, and golden retrievers being more prone) and ligament degeneration due to age or obesity can increase the risk. Due to these genetic and degenerative factors, 50-60% of dogs with a CCL injury in one knee are likely to suffer the same injury in the other knee.

Signs of a CCL Injury

Pets with CCL injuries often show signs of pain and discomfort, including:

Sudden lameness or limping (Some pets will avoid putting any weight on the affected leg while others might only limp after exercise)
Struggling to rise, sit, or climb stairs
Decreased activity
Swelling around the knee joint

Two veterinary technicians safely restraining a dog for x-rays at Animal Emergency & Referral Center of Minnesota.

Diagnosis

Diagnosis of a CCL injury is usually based on:

Physical examination
X-rays
- X-rays don’t show soft tissue injuries like a CCL tear; however, changes to the knee, such as fluid within the joint and/or secondary arthritis, can be seen. These changes support a diagnosis of damage to the CCL.

Confirmation of a tear is ultimately made during surgery by direct visualization of the ligament either via camera (arthroscopy) or the surgeon’s own eyes in the open approach (arthrotomy). The other structures in the joint are also evaluated, such as the cartilage within the knee or menisci, to ensure there is no concurrent damage.

Three x-ray images. The first one is of a dog's CCL injury prior to surgery and the second two images are x-rays of the CCL injury post-surgery.

Treatment

Treatment options include medical management and surgery.

Medical management usually includes 8-12 weeks of activity restriction, pain medication, and physical therapy. The goal is for the body to develop scar tissue outside the knee, thus stabilizing the joint without surgical intervention.
- This approach can have a good prognosis for dogs that are less than thirty pounds. Surgery is usually recommended in dogs that are larger or have a high-energy level.
There are a variety of different surgical options to address a cranial cruciate ligament injury. Which procedure is recommended depends on the age and size of the pet, as well as the surgeon’s preference. These factors will be discussed at your consultation – prior to surgery.
- The procedure typically performed at AERC for a CCL injury is a Tibial Plateau Leveling Osteotomy (TPLO).
  - The surgeon makes a cut in the shin bone (tibia), rotates it, and stabilizes the new position with a bone plate and screws. This alters the biomechanics of the knee so that the limb can be functional without the CCL.
  - The post-operative period requires activity restriction for 8-10 weeks, an E-collar, pain medication, and general and incisional monitoring.
    - Sutures along the incision are removed 10-14 days after surgery.
    - Recheck radiographs are performed 8 weeks after surgery to ensure the bone is healing well before returning to normal activity.
    - While TPLO may seem like a big procedure and recovery, most dogs tolerate it well. The long-term goal is to get your dog back to running around and playing like nothing ever happened!