Cranial Cruciate Ligament Injuries in Dogs

What is the Cranial Cruciate Ligament?

The Cranial Cruciate Ligament (CCL) is equivalent to the ACL in people. It is one of four ligaments in the stifle (knee) responsible for maintaining stability. These knee stabilizers are called the medial and lateral collateral ligaments and the cranial and caudal cruciate ligaments.

The CCL specifically helps prevent the knee from rotating inwards and hyperextending. All of these ligaments are inside the knee joint, so if the CCL becomes partially or completely torn, it can cause a lot of inflammation in the joint. In addition, the knee becomes unstable, rotating inwards inappropriately, causing further pain. Excess stress is then put on other ligaments, such as the meniscus, which can tear and cause even more pain and inflammation.

Facts About Cranial Cruciate Ligament Disease in Dogs

• It is the most common orthopedic condition in dogs (out of about 40 conditions affecting back legs in dogs)
• CCL injuries are a relatively rare orthopedic condition in cats
• Dogs can have a partial or complete rupture of the CCL
• Symptoms can have a sudden onset or be chronic in nature
• Dogs with CCL injuries will show varying degrees of lameness (limping)
• Osteoarthritis (arthritis) will occur as a result. This is the body’s method to stabilize the knee on its own, but it is slow and painful. This process begins immediately after the injury and worsens over time.
• Surgical stabilization of the knee can significantly decrease the amount of arthritis that develops.

Causes of CCL Disease in Dogs

• Trauma - May occur at a time of high impact activity, accident, or injury. This results in a very unstable knee where your dog will suddenly hold up the leg completely and develop a non-weight-bearing lameness.

• Genetic - Slow, gradual degradation of the ligament, causing waxing and waning symptoms over time. You may still notice symptoms suddenly, but not be able to relate them to a traumatic event. Unfortunately, genetic causes of CCL disease often lead to tearing of both the left and right ligaments within 2 years of each other.

Clinical Signs of Cranial Cruciate Disease in Dogs

• Lameness, limping, abnormal gait
• Lameness is chronic, always on the same leg, and doesn’t get better on its own
• Holding up the leg completely, toe-touching, or using the leg with a limp
• Limping can be worse if your dog is affected by a tick-borne bacterial infection such as Lyme, Anaplasma, and Ehrlichia which can cause joint swelling
• Dog won’t jump up (onto bed or couch, into the car)
• Decreased activity

Diagnosing CCL Injuries in Dogs

Diagnosis is usually made by a combination of examination and x-rays:

• Orthopedic exam - A vet can feel the dog’s knee and determine if one or both typical signs of a torn cranial cruciate ligament is present: cranial drawer and tibial thrust

• Radiographs - X-rays will show any joint swelling, fractures, genetic bony abnormalities, arthritis, and previous injuries (you cannot see the cranial cruciate ligament itself on an x-ray)

Treatment of CCL Injuries in Dogs

Treatment depends on the severity of the condition, the age, weight, and size of the pet, and the time at which it is diagnosed versus when the injury occurred. Surgery is often recommended because, without it, the knee develops far more arthritis, resulting in stiffness and pain that can worsen over time.

Strict rest

• Often advised for the first two weeks before slowly increasing daily activity for the following 4 weeks
• Activity restrictions include cage rest, no running, jumping or high impact activity, no catching balls or frisbees, no walks, just going outside to urinate and defecate on a leash at all times
• Restricted areas of movement so there is no running indoors throughout the home
• No stairs, no jumping UP onto couches, beds, or into cars

Joint supplements

• Supplements such as glucosamine and chondroitin are often given daily for life in any pet who has an injury involving a joint, both with and without surgical treatment

Medications

Medications such as NSAIDs (non-steroidal anti-inflammatory pain medications), neuromuscular pain medications, and/or synthetic opioid pain medications may be indicated and prescribed by your vet.

Surgery

Surgery to stabilize the cranial cruciate ligament is often performed by a board-certified veterinary surgeon. However, many general practice veterinarians will perform surgery as well. Surgery is typically recommended in young, large dogs due to their size and weight and the number of years they have left to run and play. Surgery is not always advised in smaller dogs who may manage with only pain medications and strict rest while healing.

Unlike in people, the surgeon does not attempt to repair or replace the ligament using a person’s ankle ligament or that of a cadaver. Instead, in veterinary medicine, surgeons stabilize the knee using a different procedure.

There are three surgical procedures that can be performed to stabilize the knee. Surgery will always consist of opening up the joint capsule, removing and cleaning out any torn and damaged pieces of the CCL, and closing the joint. Then, one of the following procedures is performed:

1. Extracapsular Repair

• Tradition surgical repair method using large gauge, strong suture through portions of the tibia and fabella bones to tighten and stabilize the joint
• No hardware is involved, so some general practice vets will perform this surgery
• This procedure is typically better for smaller and/or lighter dogs
• Less invasive procedure

2. Tibial Plateau Leveling Osteotomy (TPLO)

• The most common surgery of choice for CCL rupture in dogs, especially larger, heavier dogs
• More invasive than extracapsular repair
• Requires a veterinary surgeon with specialized training
• Involves cutting and rotating tibia and the use of hardware to change the angle at which the femur bears weight onto the flat ‘plateau’ of the tibia

3. Tibial Tuberosity Advancement (TTA)

• More invasive than extracapsular repair
• Requires a veterinary surgeon with specialized training
• Involves cutting and repositioning the tibial crest (area of the tibia where the patellar ligament attaches) and the use of hardware to change the angle of the patellar ligament

Rehabilitation after surgery may include massage, icing, passive range of motion and stretching exercises, hydrotherapy (water treadmill), slow, controlled walking, laser therapy, acupuncture, and more. Rehabilitation helps manage pain by decreasing inflammation, maintaining good range of motion in the joint, encouraging use of the limb, decreasing muscle atrophy, and increasing proprioception.

For information on the four phases of rehabilitation, click here.

For easy to understand anatomical diagrams and information about cranial cruciate ligament ruptures in dogs, click here.

Read more:

Nothing to bark about! Causes of Limping in Dogs (and what you should do!)

Joint Supplements for Pets

Need to speak with a veterinarian regarding your dog's injury or another condition?

Click here to schedule a video consult to speak to one of our vets. You can also download the FirstVet app from the Apple App Store and Google Play Stores.