The knee is a weak point in your cat’s body and is subject to injury and other damage. This is especially true when stress is put on the joint due to injury or pressure from jumping from heights or from awkward positions. When the cranial cruciate ligament (CCL) tears, this is known as a rupture. The rupture can cause pain, limping and a variety of other side effects, including permanent joint defects. This condition is more common in dogs but does also occur in cats.

The cranial cruciate ligament is a connective tissue located in your cat’s knee that helps stabilize the joint in order for proper movement of the legs as the surrounding muscles flex. This ligament is one of the most important structures of the joint. In humans, this ligament is known as the ACL.

Symptoms of CCL rupture in your cat tend to be acute, meaning that they will come on suddenly as the result of injury/rupture. Pets, and cats in particular, however, do not have the same sensitivity to pain as humans. Signs to watch for include:

The cause of a CCL rupture in your cat is either a full or partial tear in the canine cruciate ligament, located within the knee. Without this important structure, the knee suffers from instability. CCL ruptures most often occur as a result of injury, such as a sudden movement or torsion of the leg. This can occur especially in cats when their legs become trapped or when they suffer a large fall or collision with a vehicle or other object. Cats that are overweight also are more susceptible to CCL ruptures due to the additional stress on the joint.

Your veterinarian will diagnose a cranial cruciate ligament rupture in your cat with a complete physical exam. Your vet will cautiously manipulate each of your cat’s limbs to check for swelling or injury. Your vet may also want to observe your cat’s gait by allowing them to walk across the vet office floor. Cats suffering from CCL injuries tend to have a distinctive type of limp that can help pinpoint this injury.

Your vet will next perform something called a drawer test. This will involve the manipulation of your cat’s knee joint in an attempt to produce movement similar to that of a drawer pulling out. In a joint with a healthy, intact CCL, this movement is not possible. This test may be difficult if there is a great deal of swelling or if your cat is in tremendous pain.

Finally, your vet will perform x-rays or MRI imaging. While x-rays alone cannot identify a CCL tear, they can show abnormalities in the surrounding tissue, such as from arthritis, which is a common sign of a CCL rupture especially in chronic cases or cases in which limping has been a long-term issue. In the case of injury, this will also help rule out any additional broken bones.

There are two main treatment options for a ruptured cranial cruciate ligament in your cat. The first is a conservative approach. This is often used when a partial tear is suspected or when a cat is too old or is otherwise a poor choice for surgery. In this treatment, your cat will be given medications for pain and anti-inflammatory drugs and the surrounding tissues in the knee allowed to heal. Since ligaments have poor blood flow, they themselves do not regenerate. However, scar tissue may build up around the area which can assist in compensation for the lack of stabilization as a result of the torn CCL. This approach is not recommended for very young or active animals, since it can lead to chronic pain and injury and doesn’t withstand a great deal of movement.

The second treatment option is surgery. There are many surgical variations that have been developed in recent years. These options involve various methods of creating an artificial ligament or replacement stabilization of the joint using permanent sutures that are connected to the bone of the knee. These procedures tend to be highly effective in cats given their light weight.

Proper rest and restriction of movement while your cat heals will be crucial to its long-term recovery. For several weeks to months after surgery, your cat will need to be confined to a small space, with limited movement. Jumping, running or other jolting may disrupt the healing process or cause additional damage. Your vet may also recommend physical therapy for your cat, which may involve stretching of the limb and various exercises either at home or in a pet rehabilitation office.

The prognosis for recovery of your cat, if the proper treatment protocols are followed, is very good.