If you have noticed your dog favouring their hind leg, you may want to have them checked by your family veterinarian or make an appointment with a board-certified veterinary surgeon* to have it assessed. A torn cranial cruciate ligament (CCL) is a common knee injury for dogs – it is similar to anterior cruciate ligament (ACL) injuries in humans.

A dog’s cranial cruciate ligament (CCL) connects the shin bone and thigh bone at the stifle (knee). If the CCL is damaged, it causes discomfort and prevents a dog from being able to walk properly. It is painful and negatively impacts their well-being if left untreated.

If your pup has this kind of injury, a decision for treatment needs to be made quickly. Tibial plateau leveling osteotomy (TPLO) surgery is the procedure that stabilizes a knee with a CCL injury, and it has a very high success rate. At Boundary Bay Veterinary Specialty Hospital, our board-certified surgeons perform several of these surgeries every week. We also provide 24-hour aftercare to our patients supervised by our board-certified critical care specialists, and work to create a recovery plan for our patients and their owners that works for them.

We sat down with one of our BBVSH surgeons, Dr. Evan Crawford, who has done many tibial plateau leveling osteotomy (TPLO) surgeries, to ask him about some of the common questions we receive about this surgery.

What exactly is the cranial cruciate ligament?

The cranial cruciate ligament is the canine counterpart to the ACL, and among both dogs and humans, tears or ruptures in these ligaments are common—but that doesn’t make them any less painful.

Ligaments are tough, fibrous bands of tissue that hold bones and cartilage in place. We have two ACL ligaments that connect the thigh (femur) bone to the shin (tibia) bone. These ligaments cross inside the knee joint (like a cross, giving them their name) and keep the knee stable during physical activity.

Dogs have four main ligaments stabilizing their stifles (knee joints, in vet speak) with the CCL being the most commonly injured one.

What causes cranial cruciate ligament ruptures (CCLR)?

In humans, it is often sports-related trauma, including twists and hyperextension, that is the leading cause of ACL damage. Dogs are different. They don’t have to suffer a significant trauma to experience a ruptured CCL because their physiology and biomechanics leave them vulnerable to CCL damage.

Dogs affected with CCLR seem to have an underlying degenerative condition of the ligament.  This results in it slowly breaking down over time, and unable to handle the normal stresses of day-to-day life.

When dogs walk, their stifles (knees) are bent most of the time (versus people who usually walk with their legs much straighter) and the top of their tibia has a slope to it as well (called the tibial plateau slope).  Hence, when dogs stand or walk, the tibia tries to slide down the slope and push the tibia forward.  The CCL usually prevents this from happening.  If it is damaged, then the stress on the injured ligament causes pain, and if it is broken, then the bones start sliding abnormally against each other, causing progressive damage to the cartilage and/or arthritis in the joint, and discomfort.  There is also a small cartilage pad called the meniscus inside the joint that helps cushion the interaction of the bones; when a CCL is broken and the bones are sliding abnormally against each other, the meniscus can get pinched and torn.

Cranial cruciate ligament ruptures can affect any dog of any age, though some breeds, including golden retrievers and rottweilers, are more prone to CCLRs. Dogs with higher tibial plateau slopes are also more likely to injury their CCLs and, for reasons still being explored by orthopedic veterinary specialists, female large-breed dogs in their prime make up a disproportionately large number of CCLR cases.

Other contributing factors include:

• Obesity
• Poor conformation (body structure)
• Aging
• Genetics (hereditary or breed-related)

In humans, vigorous exercise and physical sports are the most common causes of ACL injuries, but dogs who don’t get regular exercise are actually at greater risk of a CCLR, probably because they lack muscle strength to help support the ligament, and the extra strain their weight puts on it causes more deterioration

There’s no surefire way to prevent CCLR other than to keep your dog fit and to keep them from getting overweight.

What are the signs and symptoms of cranial cruciate ligament disease (CCLD)?

Since dogs can have significant variation in degree of cruciate ligament injury, the condition is usually referred to as ‘cranial cruciate ligament disease’ (CCLD), with a complete rupture / tear being the end stage of the disease. While the clinical signs (symptoms) associated with CCLD vary, the condition invariably causes rear limb dysfunction and pain.

Dogs with CCLD may exhibit any combination of the following signs (symptoms):

• difficulty rising from a sit
• difficulty in the process of sitting (“positive sit test”)
• trouble jumping into the car
• decreased activity level or unwillingness to play
• lameness (limping) of variable severity, sometimes only noted after long periods of rest
• muscle atrophy (decreased muscle mass in the affected leg)
• decreased range of motion of the knee joint
• a popping / clicking noise (which may indicate a meniscal tear)
• firm swelling on the inside of the shin bone (fibrosis or scar tissue)
• pain
• stiffness

Pain and discomfort are expressed differently in people compared to dogs, so although dogs may not whine, cry out, or hold up their affected limb constantly, the persistence of their lameness is pain.

How does my veterinarian diagnose CCLD and determine whether my pet needs a tibial plateau leveling osteotomy (TPLO) surgery?

Diagnosing damage to the CCL can be challenging.  A strong suspicion of a complete tear can usually be made using a combination of gait evaluation and physical exam findings.  Partial injuries can be harder to identify, and the manipulations that help make the diagnosis can be challenging in dogs that are very anxious / tense, and in very large dogs.  Radiographs (x-rays) are usually recommended; MRI and ultrasound can be used to try and evaluate the ligaments but are not usually required.  The ligament cannot be seen on x-rays; ultimately the confirmation of a cruciate ligament is made based on direct visualization via an arthroscopic (examination with a small fibre-optic camera) evaluation of the joint, or an arthrotomy (a small incision into the joint) to directly inspect it.

 

Radiographs allow your veterinarian to:

• confirm the presence of a soft tissue opacity consistent with joint effusion (fluid accumulation, mostly inflammatory in nature, in the stifle joint, indicating that there is an abnormality present)
• evaluate for the presence/degree of arthritis
• take measurements for surgical planning
• rule out concurrent disease conditions

Specific palpation techniques that veterinarians use to assess the CCL include the ‘cranial drawer test’ and the ‘tibial compression test.’ These tests can confirm abnormal motion within the knee consistent with rupture of the CCL.

Prior to surgical intervention or administration of anti-inflammatory medications for pain relief, your veterinarian will also likely perform bloodwork or ensure that your pet had it recently performed. Knowing the overall health of your pet is important before focusing on an orthopedic surgery or dispensing certain medications.

What is the treatment for CCLD?

Many treatment options are available for CCLD. The first major decision is between surgical treatment and non-surgical (also termed conservative or medical) treatment/management. The best option for your pet depends on many factors including their activity levels, size, age, skeletal conformation, and degree of knee instability.

Non-surgical treatment usually involves a combination of pain medications, exercise modification, joint supplements or joint injections, physical rehabilitation (dog physiotherapy), and possibly braces/orthotics.

Surgical treatment typically results in the best outcomes with CCLR since it is the only way to permanently control the instability present in the knee joint. The most common surgery performed to stabilize a knee with a damaged CCL is the tibial plateau leveling osteotomy (TPLO).

Surgery addresses one of the main issues associated with CCLD—knee instability and the pain it causes because of the loss of normal CCL structural support. The goal of surgery is not to “repair” the CrCL itself, since it is generally a degenerative condition of the ligament, repairing the ligament would only be a very temporary repair.  Instead, surgery seeks to stabilize the joint in other ways.

Here at BBVSH, in addition to performing TPLOs, we have the experience and capacity to do other surgical procedures to stabilize a cruciate deficient stifle such as TTA, CBLO, CCWO, TightRope®, Flo technique etc., and can discuss with you the pros and cons of all of those options.

What is tibial plateau leveling osteotomy (TPLO) surgery?

Tibial plateau leveling osteotomy (TPLO) is a procedure that, simply put, decreases the angle at the top of the tibia. This surgery greatly reduces or eliminates the force pushing the tibia forward, so there is no longer a need for the ligament to be present to prevent that motion.

During the operation, your veterinary surgeon will cut and rotate a portion of the bone, inserting a plate and screws to secure the bone in the new position while it heals. This alteration levels the tibia, preventing the femur from sliding down and off its surface.

In more than 95% of TPLO treatments, the plate and screws are left in place forever, so further surgery to remove them usually isn’t necessary. There are rare situations where the implants need to be removed, mainly due to infection.  If your vet opts to remove these materials, the procedure is simple and won’t complicate or prolong your dog’s final recovery, and removal of the implants does not eliminate the stabilizing effect of the surgery.

Check out this video: CCL Tears and How a TPLO Surgery Works

How quickly will my dog recover from tibial plateau leveling osteotomy (TPLO) surgery?

Dogs will typically stay overnight with us and go home the day after a TPLO, which helps reduce psychological stress on both you and your pet and keeps the final costs lower. This 24-hour aftercare in our hospital is to ensure they are fully recovered from surgery, to ensure they are comfortable on medications you can give at home after, and to make sure they are starting to use the leg appropriately as the local anesthetic blocks used during surgery wear off. During their stay, our patients are under the care and supervision of board-certified critical care specialists who have access to any of our other board-certified specialists on an on-call basis.

Recovery is relatively quick; you can expect your dog to be up on her feet and putting weight on her leg within a few days, and after a period of restricted activity defined by your veterinary surgeon, she’ll likely be able to participate in all or most of the activities she enjoyed before her CCLR symptoms first appeared.

TPLO isn’t an experimental treatment. It’s been around for more than 20 years, and during this time the most talented veterinary surgeons have refined the technique and shared their knowledge among their peers. More than 200 academic papers document the effectiveness of TPLO, and outcomes are overwhelmingly positive.

Is My Dog a Good Candidate for tibial plateau leveling osteotomy (TPLO) surgery?

That’s a team decision made by you, your family veterinarian, and your surgical specialist. When you consult your veterinary surgeon, they will evaluate your dog’s overall health to determine whether or not they will benefit from CCLR surgery. Any procedure requiring anesthesia is a risk, and your dog’s physical condition and age are important factors in determining whether surgery is the best option.

Tibial plateau leveling osteotomy and other CCLR treatments can’t reverse secondary damage caused by CCLR, nor does it address other issues related to your dog’s knees. Torn meniscal ligaments, problems with the patella (kneecap), and arthritis are separate issues that TPLO can ease, but not repair. If other concerns are identified, much of the time these other conditions can be addressed at the same time, or another procedure recommended to provide the optimum outcome for your pet.  Pre- or co-existing issues can reduce your dog’s chances for long-term results after any surgery, and some conditions can aggravate or become aggravated by the TPLO procedure and recovery.

Your veterinary surgeon might recommend that your dog lose weight prior to the surgery, or that you consult with your regular vet to address and remediate existing issues that could hinder your pet’s outcome. Another factor in determining whether or not your dog is a good candidate for any surgery is your willingness and ability to help your dog through the recovery process.  We will guide you through the recovery process and can help build a recovery plan individualized for your pet.  Our goal is to work with you to get your pet back to their best potential.

Why would I choose a board-certified veterinary surgeon to perform my pet’s TPLO?

Advances in animal health care have led to a wider variety of treatment options, including highly specialized surgical procedures.

Board-certified surgeons spend at least four years after achieving their veterinary medical degree (DVM) being trained by other board-certified specialists in Surgery, Radiology, Pathology, and Internal Medicine with a strict focus on diagnosing and treating surgical diseases in small animals.

This concentrated training in surgery allows the ACVS Veterinary Surgeon to keep current with frequent advances in veterinary medicine. Ask your veterinarian if your pet would benefit from a specialist.

All our surgeons at Boundary Bay Veterinary Hospital are board-certified. We have advanced equipment to do arthroscopy as needed, as well as the option to do ultrasound or MR evaluations if indicated.  We have a variety of implant systems available to fit any dog from a Chihuahua to a Great Dane, with whatever shapes of bones they may have.  We have specially trained veterinary nurses who monitor your pet during anesthesia, and who are used to providing anesthesia for patients with other underlying health concerns.  We also have the experience to address any other concurrent problems that are identified and have other specialists in hospital to help out if other health concerns are identified.  BBVSH also has an in-house physical therapy service that can help develop and provide a personalized recovery plan for your pet, to ensure the fastest and best return to function for them.

We are happy to meet with you to discuss tibial plateau leveling osteotomy (TPLO) surgery or any other treatments, provide you with all the information you need and help you make a decision that is best for both you and your pet.

 

* The term “ACVS Diplomate” refers to a veterinarian who has been board-certified by the American College of Veterinary Surgeons in veterinary surgery. Although in BC any veterinarian may use the term “surgeon”, only veterinarians who have successfully completed the certification requirements of the ACVS are Diplomates of the American College of Veterinary Surgeons and have earned the right to be called “specialists” or “board-certified” in veterinary surgery.

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About Boundary Bay Veterinary Specialty Hospital

Boundary Bay Veterinary Specialty Hospital is a family owned, veterinary specialty and 24/7 emergency and critical care hospital in Surrey, BC, serving the Vancouver metro area and greater British Columbia. We have a sister hospital in Bellingham, Washington.

As a certified VECCS Level I facility and a Level II VetCOT Trauma Centre, we are capable of handling even the most critical, life-threatening emergencies and trauma, with board-certified specialists on staff and on-call to handle any medical or surgical issue.

Our board-certified specialists offer services in emergency and critical care, surgery, internal medicine, cardiology, neurology, oncology, dentistry, diagnostic imaging, and animal rehabilitation.