Cranial cruciate ligament tear a common pet injury
Limping or lameness is one of the more common medical problems encountered by dog owners and veterinarians.
Often, determining the origin of lameness poses a difficult and frustrating challenge. There are many types of orthopedic problems that affect dogs and many of these incidents can resolve on their own with rest and time. Minor sprains, twists or muscle bruises account for a large percentage of these common problems. Persistent lameness that last more than a few days, lameness associated with trauma, and severe or worsening lameness problems should always receive the attention of a veterinarian.
Determining the underlying cause of lameness begins with a thorough history and physical exam. Many common conditions are congenital (inherited) and the age and breed of dog often gives the first clues as to the cause of lameness.
Puppies are often affected by genetic cartilage defects, panosteitis (growing pain), dysplasia or growth abnormalities of the hips, shoulders or elbows, or luxation of the patella (knee cap).
Middle-aged dogs are commonly affected by hip dysplasia, tendon injuries to the shoulder, cranial cruciate ligament tears in the knee, Iliopsoas strain in the pelvis and intervertebral disc disease, or conditions because of instability in the spine.
Geriatric dogs have many of the same conditions as their middle-aged counterparts with the addition of degenerative joint disease/osteoarthritis and cancer.
One of the most common orthopedic injuries seen in dogs is a partial or full rupture of the cranial cruciate ligament (CCL) of the stifle or knee joint. The term “ACL tear” is often used synonymously to compare this injury to rupture of the anterior cruciate ligament in people.
This is a common traumatic injury typically seen in athletic, large breed dogs, but also occurs in small breeds as well as less active or overweight pets. Often this injury occurs while chasing a squirrel in the backyard or playing fetch. A ruptured CCL results in limping in the hind limb with little or no willingness to bear weight on the leg. As with injuries in ourselves, the initial discomfort, pain and swelling may subside after five to seven days and your dog may begin to walk better. However, because the ligament has been damaged or torn, the knee is unstable and after several weeks, this instability will cause tearing of the meniscus which again leads to pain and swelling within the joint.
Inflammatory changes that lead to arthritis and degeneration of the joint begin within two weeks post-injury, which makes early diagnosis and treatment critical for improving the long term prognosis.
Diagnostic tests to confirm a ruptured ligament include palpation of the knee to assess laxity, which often requires that your dog be sedated, and X-rays to determine if there is swelling within the joint. In most cases, CCL rupture requires a surgical repair in order to restore function, reduce pain and slow the development of arthritis.
Unlike their human counterparts, dogs with even partial CCL tears generally will benefit from surgery. This is largely due to the unique forces that the dog’s stifle undergoes that differs from the vertical position of our knees.
Without surgery, chronic instability leads to arthritis and meniscus tears, and puts the opposite knee at risk of injury because of overcompensation. In fact, even with surgery, a majority of dogs that rupture their CCL will rupture the ligament in the opposite knee within a year or two.
There are several surgical options available, each differ in outcome, recovery time, and cost. Your veterinarian will work with you to determine the best surgical approach for your pet, based on activity level, age, weight and financial considerations.
The prognosis for dogs after CCL repair is excellent, and, depending on the type of surgery performed, most dogs return to normal function. Physical therapy including cold laser therapy can greatly reduce healing time and discomfort postoperatively.
While there is no way to prevent CCL injuries in your dog, there are steps that can be taken that may reduce the chances of injury. Keeping pets in ideal body condition, exercising regularly, and avoiding play that encourages high jumping will help to reduce the risk of CCL damage.