Cranial cruciate ligament (CCL) disease is one of the most common orthopedic issues affecting pets, particularly dogs. Our Fusion Veterinary Orthopedics specialist Dr. David Dycus frequently treats pets with this condition, and we provide information about CCL disease in dogs and cats.

A pet’s normal cranial cruciate ligament

To understand CCL disease, you must first understand the ligament’s normal anatomy and function. The CCL in pets is equivalent to the anterior cruciate ligament (ACL) in humans and one of the most important stabilizers in the knee joint. The knee joint consists of multiple components, including the femur above, the tibia below, the kneecap in front, and the bean-like fabellae behind. Menisci (i.e., cartilage-like structures) sit between the femur and tibia to absorb shock, assist with position sensing, and provide cushion-like support. Numerous ligaments that hold the joint together allow the knee to bend properly. The cranial and caudal cruciate ligaments attach to one side of the femur on top and the opposite side of the tibia on the bottom, crossing inside the knee joint. The CCL’s main responsibility is preventing the tibia from moving forward in relation to the femur as well as preventing hyperextension of the knee, and excessive internal rotation of the knee.

Cranial cruciate ligament disease in pets

CCL disease can be caused by numerous factors, such as ligament degeneration, genetic predisposition, conformation, and injury. Excess weight can increase a pet’s CCL injury risk. 

In dogs, CCL disease is most commonly caused by degeneration. Dogs of all breeds and sizes can be affected, but some breeds, including rottweilers, Labrador retrievers, Saint Bernards, and Mastiffs, are at higher risk. Partial CCL tearing is common in dogs and often progresses to a full tear. Also, 40% to 60% of dogs with CCL injury in one knee will eventually have the same problem in the opposite knee.

In cats, CCL disease is most commonly caused by trauma. When degenerative disease occurs, the affected cat is typically overweight.

Cranial cruciate ligament disease signs in pets

CCL disease is one of the most common reasons for hind limb lameness in dogs, and hind limb lameness after trauma is the most common presenting sign in cats. Other potential signs include:

  • Difficulty rising from a resting position
  • Trouble jumping on or off elevated surfaces
  • Stiffness in the hind end after resting
  • Difficulty navigating stairs
  • Decreased interest in activity
  • Muscle wasting over the affected side
  • Swelling inside the shin bone

Cranial cruciate ligament disease diagnosis in pets

If the CCL is completely ruptured, the diagnosis involves gait evaluation, special palpation techniques, and X-rays, and is typically straightforward. If the tear is partial, advanced imaging, such as magnetic resonance imaging (MRI) or surgical exploration through arthroscopy, may be necessary to better evaluate the joint and determine the problem.

Non-surgical management of cranial cruciate ligament disease in pets

Non-surgical CCL disease management may be an option for cats and some dogs who are not particularly active. This strategy involves:

  • Restricted activity
  • Physical therapy
  • Pain and anti-inflammatory medications 
  • Knee braces in select dogs
  • Weight management

Surgical management of cranial cruciate ligament disease in pets

Surgical treatment is the best option for pets with CCL disease. The knee must be stabilized to help slow or reduce arthritis development. Several techniques are used, but common procedures include:

  • Tibial plateau leveling osteotomy (TPLO) — The TPLO involves cutting the top part of the tibia and rotating the bone to change the angle where the femur bears weight.
  • Tibial tuberosity advancement (TTA) — This procedure, which also involves cutting bone, changes the patellar ligament’s angle by cutting and repositioning the front part of the tibia. 
  • Extracapsular suture stabilization — This technique uses suture material to stabilize the joint until scar tissue can form around the joint.

At the current time, Dr. David Dycus recommends the TPLO procedure over other surgical options. In addition, at the time of the TPLO, he will perform minimally invasive joint inspection utilizing arthroscopy. 

Proper postoperative care, involving activity restriction, pain management, and physical rehabilitation, is important to ensure the best possible outcome. Pets who undergo surgery to treat CCL disease typically develop arthritis more slowly than those who are managed non-surgically. 

If your pet favors a hind limb, contact our Fusion Veterinary Orthopedics team, so Dr. David Dycus can determine if they have CCL disease and the best treatment strategy to get them moving normally again as soon as possible.