Can a Cranial Cruciate Ligament Rupture be Treated with an Ankle Brace?

Posted by Ruby Porter CCRP (she/her) Certified Canine Rehabilitation Practitioner

05/31/2024

Can a Cranial Cruciate Ligament Rupture be Treated with an Ankle Brace?

What is a Torn Cranial Cruciate Ligament (CrCL)?

One of the most common injuries in dogs is a torn cranial cruciate ligament (CrCL) within the knee. Many may call this a  cranial cruciate ligament rupture, ACL tear, or just a blown knee. All of these terms describe the same condition. The cranial cruciate ligament is one of five main ligaments within the dog's knee and the one most commonly torn, similar to how a rope tears after being used repeatedly. There can be full tears, as well as partial tears. You may be asking yourself, “what does a ligament do?”. A ligaments job is to connect two bones together within a joint. With a torn CrCL, the dog’s lower leg bone, the tibia, moves forward in the direction of their head, in relation to the upper leg bone, the femur. This abnormal movement when standing is commonly called cranial tibial thrust, and it occurs during weight bearing. It is not a lot of movement, just a few millimeters, but that small abnormal movement will cause instability, which leads to arthritis and pain that can be expressed by the dog in varying degrees of lameness/limping. Lameness can also be intermittent and sometimes can be worse after rest and/or intense exercise. While I was practicing physical rehabilitation in a clinical setting, I saw thousands of dogs recovering from CrCL tears. One of the most common histories I heard from dog parents was that their dog suddenly started limping, they went to their regular vet, anti-inflammatories were prescribed, the dog would get better for a few weeks, get worse again, and then be referred to a specialty clinic. 

Diagnosis 

Most times a veterinarian can diagnose a cranial cruciate ligament (CrCL) rupture in dogs through a  normal orthopedic exam. However, partial tears of the CrCL may require a sedated physical exam and possibly X-rays. You cannot see ligaments on x-rays, but rather the joint inflammation, arthritic changes, and misalignment caused by the torn ligament.  X-rays can also help rule out other problems, such as fractures and cancer, and help with surgical planning. Some surgeons use arthroscopes to diagnose partial tears as well. It is important to realize that most veterinary surgeons now refer to torn CrCLs as a degenerative disease and that there is likely a strong  genetic component to the injury. In other words, there is an environmental trigger that sets off the genetically predisposed condition. With that said, 50-60 percent of dogs who rupture one CrCL will rupture their other CrCL within about a year. The American College of Veterinary Surgeons states that there is a  breed predisposition for CrCL disease in the Rottweiler, Newfoundland, Staffordshire Terrier, Mastiff, Akita, Saint Bernard, Chesapeake Bay Retriever, and Labrador Retriever. Although less common, Bulldogs and other Chondrodystrophic Breeds (short legged breeds) can have problems with their knees too, including but not limited to patella (kneecap) luxations and CrCL tears. The conformation of Chondrodystrophic Breeds can also pose Custom Bracing challenges that will be addressed later in the blog. 

Stance and swing phases for Hock/ Stifle Blog

Treatment

Surgery tends to be the best option when you talk with a surgeon, however conservative treatment via custom bracing shows similar pet owner satisfaction in retrospective studies(see link below for reference). Surgery poses risk factors and aftercare that not everyone is willing or able to do. I have seen good results with both surgery and custom bracing treatments during my years as a canine physical rehabilitation practitioner and think each pet owner should be well informed so that they can make the best decision for both their dog and themselves. Some of the factors that affect owner satisfaction may include anesthetic risks, aggravation of other medical conditions, patient age, the possibility of 8-12 weeks of strict cage rest following surgery (often required after surgeries involving an osteotomy such as the TPLO), skin/incision infection, and complications such as the need for implant removal in cases with infection or a loose implant. Cost is a big factor and that is a fact.  Surgical costs for a TPLO or similar surgery can be between $5000- 7000 for one leg. I saw very few dogs that did not blow out their other knee over my clinical career. That means you could easily pay upwards of $14,000 to have your dog’s knees fixed with surgery if you do not have the proper coverage with  pet health insurance. These figures don’t always include the additional costs for physical therapy following each surgery. That is a pretty big number that not all of us can afford.  Hero Braces are custom and hand made for each dog patient. The current cost of each brace is $996. A veterinary professional will need to cast your dog’s limb/create a mold so that we can create a custom brace for your dog. Off the shelf braces do not work in my opinion and experience as there are so many sizes and shapes of dogs. This makes it nearly impossible for an “off the shelf” version to provide the needed comfort and stability. 

Which Brace is Right for Your Dog? 

The  Hero stifle/knee brace is the best choice for dogs with a cranial cruciate ligament (CrCL) rupture that are not having surgery. It has knee joints built into it, is lightweight, and helps stabilize the dog's knee joint. However, in short legged breeds like Bulldogs, leg length can pose a challenge for our standard brace to work properly. In these cases, a  hock brace can be used instead. This may sound a little crazy, right? How can a hock/ankle brace be used to help stabilize a stifle/knee? In order to understand this concept, we need to go back to the previously described abnormal movement caused by the torn CrCL called cranial tibial thrust. Cranial tibial thrust only happens when a dog bears weight on their limb during what is called the stance phase of gait. There are two phases of a gait cycle. Stance phase, when the foot is in contact with the ground and supporting the dog’s weight, and swing phase, when the leg is swinging forward getting ready to contact the ground again. During the stance phase, the hock or ankle flexes under the stress of the animal’s weight. Cranial tibial thrust happens when the hock flexes under a load. (see video 1). Immobilizing just the hock joint with a brace doesn’t really work, which is why we have to use a force couple or ground reaction force AFO (Ankle Foot Orthosis) design. Force couples are when 2 or more muscles on opposing sides of a joint work together to provide stability. In this case, we have lost the ligament that helps prevent cranial tibial thrust. We need the opposing force on the front side of the limb to push back on the tibia or shin. We can apply a force to the front of the tibia through a ground reaction force AFO. By adding a foot plate to an ankle orthosis, the force of standing on the plastic is transferred up to the plate in front of the shin and is directed towards the back side of the leg. This causes extension or straightening of the knee and counteracts the cranial tibial thrust. 


Conclusion 

There are many treatment options for dogs with cranial cruciate ligament disease. Depending on who you talk with and their personal experiences, you may get a lot of different answers. In my opinion, it is ideal to talk with your veterinarian(s), have your dog’s knee examined and learn about both conservative management with custom bracing and surgical options. Then you will be well informed and can make the best decision for you and your dog. It’s great to know Hero Braces has more than one option for your pet’s knee injury. If you have questions, please reach out to us at hello@goherogo.com

1. Owner satisfaction study link: https://avmajournals.avma.org/view/journals/javma/249/4/javma.249.4.391.xml