> What is the Cranial Cruciate Ligament?
The cranial cruciate ligament (CCL), called the anterior cruciate ligament (ACL) in humans, is a tough band of tissue that connects the two main bones of the knee joint. The CCL attaches the upper bone (femur) to the lower bone (tibia) and helps prevent excessive motion between these bones. A ruptured CCL is the most common orthopedic injury in dogs and results in a painful and unstable joint. If left untreated, a ruptured CCL will lead to progressive and irreversible degenerative joint disease (arthritis).
> Why did my dog rupture this ligament?
There are generally two ways a dog’s cranial cruciate ligament can rupture. The first way is similar to a sports injury in people. Like a basketball player who plants their leg aggressively and then tears their ACL, a dog’s CCL may suddenly rupture from excessive force and leave the dog with an unstable and painful knee. A dog can also experience years of normal “wear and tear,” leaving the ligament weak and prone to total rupture. We don’t always know why or how a ligament ruptures. Some dogs begin limping after playing aggressively in the park, while others simply step off a curb and begin limping. We do know that obesity appears to be one of the most important predisposing factors in CCL ruptures, as excess weight can cause further strain on ligaments. So, watch those treats!
> Why does my dog need surgery?
When a dog ruptures a cranial cruciate ligament, the joint becomes unstable. When weight is placed on the affected limb, it creates a shearing force on the joint. This shearing force is not just painful, but also potentially damaging to the cartilage (meniscus) in the joint. This abnormal shearing movement (called “tibial thrust”) predisposes the menisci (cartilage pads) to damage and promotes arthritic changes within the joint. These changes often become painful enough to render the limb useless, especially in larger dogs. Surgically repairing a knee joint after a CCL tear provides stability to the joint, thereby reducing the rate of future arthritic change. Additionally, when one CCL is ruptured, a dog will naturally transfer most of its weight to the other leg. In doing so, they inadvertently put the other CCL in danger of rupture due to overuse. If a dog has tears in both cranial cruciate ligaments, simple tasks such as rising, walking, and squatting to urinate or defecate become very difficult, and the dog’s quality of life may suffer.
> Why do different surgeons recommend different procedures?
For many years, different surgeons have advocated for several different procedures to repair ruptured cranial cruciate ligaments. Over time, many procedures have fallen out of favor as more research and technological advancements have emerged. As the veterinary industry learns more and more about cranial cruciate ruptures and repair options, there remain three procedures that consistently show the best results: Tibial-Plateau-Leveling Osteotomy (TPLO), Lateral Extracapsular Repair, and Tibial Tuberosity Advancement (TTA). Each of these procedures has its pros and cons, and most recommendations are made from the surgeon’s personal preference in accordance with what is best for each individual patient. Sleeping Giant Animal Clinic offers both TPLO and Lateral Extracapsular Repair procedures, and our veterinarians are confident that these two procedures offer excellent outcomes for a wide variety of patients.
> What are the pros and cons of the TPLO procedure?
The TPLO procedure utilizes the anatomy and mechanics of the patient’s knee to create stabilization. With this surgery, a portion of the tibia bone is cut, rotated, and stabilized to change the biomechanics of the joint—thus negating the need for a cruciate ligament. In a knee that has been repaired via TPLO, the natural weight-bearing of the dog stabilizes the knee joint. During the procedure, the knee joint is opened to remove remnants of the cruciate ligament, as well as any portions of damaged meniscus that may be present. Pros: Large breed dogs (about 40-60 lbs.) are more likely to achieve full or nearly full return to function with TPLO surgery. Cons: The TPLO is more invasive than other types of surgery and is generally associated with a slower return to functional use of the limb. This surgery also tends to be the most expensive procedure available, but it’s an excellent surgical option, especially for large-breed dogs.
> What are the pros and cons of Extracapsular Repair Surgery?
Extracapsular Repair Surgery is performed outside of the affected joint and is most effective for small-to-medium-sized dogs and cats. In this procedure, the knee joint is opened and inspected. The torn or partly torn cruciate ligament is removed. If the meniscus is torn, the damaged portion is also removed. A strong monofilament suture is used to tighten the joint to prevent the shearing force in the knee (tibial thrust motion) and effectively takes over the job of the torn cranial cruciate ligament. This surgery can be quite effective and is typically reserved for smaller dogs or cats (often weighing less than 40 pounds). Although it’s typically the least expensive option for repair, it’s also considered the most vulnerable to failure (especially in dogs over 60 pounds). If the suture line breaks before the surgery site fully heals, a second surgery would be required.
> I have been told that my dog may eventually rupture the cranial cruciate ligament in the opposite leg. Is this true?
Statistics tell us that 40-60% of dogs that rupture one cranial cruciate ligament will eventually rupture the other one as well. This is likely multifactorial and caused in part by obesity, genetics, and continued wear and tear on the ligament over time.
> What can I do to lower the chance my dog will need surgery in the opposite leg?
Obesity is one of the most important contributing factors in cranial cruciate injuries. If your dog is currently overweight, focus your efforts on a prescribed weight loss program. If you’re not sure if your dog is obese, just ask one of our veterinarians—they’ll assess your dog’s current body condition score and will explain what it means for you and your dog. Keeping your dog at a healthy weight is the best thing you can do for not only their knees, but their overall orthopedic health.
> What can I do to speed up my dog’s recovery?
Just like humans undergoing knee surgery to repair torn ACLs, dogs will benefit greatly from a physical therapy plan following surgery for a ruptured CCL. At Sleeping Giant Animal Hospital, we provide just that! After surgery, we’ll create a customized 8-to-12-week physical therapy plan that outlines daily exercises to help your dog heal faster and return to normal function sooner. The program is thoroughly explained to you before and after surgery, and we’re happy to demonstrate the specific exercises with you and your dog so you feel comfortable and confident during your dog’s healing period. From start to finish, we’re committed to walking this journey with you and your pet so we can achieve the best possible outcomes following surgery!
