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CCL Injuries in Dogs: What you need to know

Nov 06, 2015

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Photo: Diamond by Brian Kelly via Flickr

A common injury we see in dogs is cranial cruciate ligament (CCL) rupture. This is similar to the ACL tear that many human athletes experience. While dogs of all ages and breeds are at risk for CCL rupture, large, active breeds like Rottweilers and Labrador Retrievers are especially prone to CCL injuries. CCL rupture is one of the most common causes of rear limb lameness, pain and arthritis in the stifle (knee) joints of dogs. This post will help you understand how a CCL rupture happens and to make you aware of the various treatment options. As always, if you have any questions, we welcome your call and are available for consultation with a referral from your primary care veterinarian. 

What is the CCL?

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For orientation purposes, the stifle (knee) joint in the dog is first joint encountered below the hip that appears to be oriented in a forward direction. There are two ligaments inside the dog’s stifle joint called the cranial and caudal cruciate ligaments, both of which are important joint stabilizers. However, it is the cranial cruciate ligament, or CCL, that most commonly fails.

While injury to this ligament is common in both dogs and humans, CCL rupture in dogs is more complex. In humans, ACL rupture is almost always associated with acute failure as a result of traumatic injury. In dogs, CCL rupture is most commonly considered to be the result of a degenerative process. Therefore dogs can present with CCL insufficiency where the ligament may be in various stages of degeneration or where the ligament has completely ruptured. Although there are many factors that are thought to contribute to the development of CCL failure in dogs, what actually causes the initiation of the degenerative process remains undetermined.   

Due to the complex, degenerative nature of CCL ruptures in dogs, the condition is often referred to as cranial cruciate ligament disease, or CrCLD. Dogs with partial CCL insufficiency can experience progressive deterioration of rear limb function over a period of weeks to months, sometimes years. Early in the process, diagnosis of this problem can be challenging and will often require evaluation by a surgical specialist and diagnostics including sedated radiographic and orthopedic evaluation +/- a joint tap with joint fluid analysis. Partial CCL insufficiency will almost always eventually progress to complete CCL rupture. Furthermore, 40-60% of dogs that experience a CCL rupture in one stifle will often develop the same problem in the other stifle within 1 month to 2 years. 

Most common causes of a CCL rupture

CCL ruptures can be caused by a combination of many factors including:

  • Degeneration of the ligament
  • Primary trauma (relatively rare)
  • Obesity
  • Poor physical condition
  • Genetics
  • Conformation (skeletal shape and configuration)
  • Specific anatomical characteristics (tibial plateau slope)
  • Breed
    • Certain dog breeds are known to have a higher incidence of CrCLD such as Rottweiler, Staffordshire Terrier, Mastiff, Akita, Saint Bernard, Chesapeake Bay Retriever, Newfoundland and Labrador Retriever.
    • Despite this almost all pure bred and mixed breed dogs are susceptible to CCL rupture

Most common signs and symptoms of CrCLD

Dogs with a CCL rupture may exhibit any combination of the following signs and symptoms:

  • Difficulty rising from a sit
  • Sitting with the stifle(s) extended instead of in a normal crouch
  • Lifting the affected rear limb off the floor when bending down to eat or drink
  • Trouble jumping into the car
  • Decreased activity level
  • Lameness (limping) of variable severity
  • Muscle atrophy (decreased muscle mass in the affected leg)
  • Decreased range of motion of the knee joint
  • A popping noise (which may indicate a meniscal tear)
  • Swelling on the inside of the stifle joint (fibrosis or scar tissue)
  • Unwillingness to play
  • Pain
  • Stiffness

How do Veterinarians diagnose a CCL rupture?

Veterinarians can usually diagnose a CCL rupture through one or more of the following:

  • Observing gait (manner of walking, stepping, or running)
  • Physical examination of the knee by palpation
  • Radiography (x-rays)
  • Joint tap with joint fluid analysis

What are the most common treatments? (i.e. surgery vs. non-surgical)

Since dogs can experience varying degrees of CCL insufficiency, there are many treatment options. The first step is to decide between surgical and non-surgical treatment/management. This will depend on your pet’s activity level, size, age, skeletal conformation, and degree of knee instability. Most patients will benefit most from surgery; however, there are cases where financial concerns, concurrent illness, etc. may preclude operative intervention. If your dog requires a surgical treatment, your family veterinarian may refer you to a board-certified surgeon for a consultation on the best treatment option(s) and/or to perform the surgery.

Surgical treatments

Surgery is typically the best treatment option since it is the only way to permanently control the instability in the knee joint. Once the CCL begins tearing there is no way for the ligament to repair itself. So the goal of surgery is not to repair the damaged ligament.

Instead, surgery will stabilize the knee through one of two techniques: an osteotomy-based technique (TPLO, CORA-based TPLO, TTA, MMP, CCWO) or a suture-based technique (Extracapsular suture or Tightrope). 

  • Osteotomy-based technique
    The osteotomy-based techniques require a bone cut and repositioning of the bone fragment so as to alter the biomechanics of the joint, creating a stable joint environment in the absence of the CCL. The osteotomy techniques are force-neutralizing procedures. They neutralize cranial tibial thrust, which is the force that is normally controlled by the healthy CCL.
  • Suture-based technique
    The suture-based techniques involve placement of a suture between the femur and the tibia on the lateral or outer side of the stifle joint. The suture attempts to mimic the function of the normal CCL by providing physical restraint against cranial tibial thrust. The suture techniques ultimately rely on periarticular scar tissue formation to provide long-term joint stability. 

Following a complete assessment, your surgeon will discuss the pro’s and con’s of the various options and recommend the technique that he/she feels is the best option based on the individual characteristics and circumstances associated with your pet.    

Non-surgical treatments

Non-surgical treatment usually involves a combination of pain medications, exercise modification, joint supplements, physical rehabilitation, and braces/orthotics, if necessary. 

Post-operative care

After surgery, it is important that the surgeon’s discharge instructions are followed carefully at home. Uncontrolled or excessive activity post-operatively can cause complete or partial failure of any surgical repair. Along with activity restriction, physical therapy under the strict supervision of a licensed veterinary physical therapist (LVPT) may be beneficial beginning as soon as 2 weeks after surgery to speed recovery and potentially improve the final outcome. If engaging the LVPT is not an option, it is best to wait to start physical therapy until your surgeon approves the beginning of the rehabilitation phase of your pet’s recovery.  

What you can do to reduce the risk of CrCLD in your dog

Poor physical body condition and excessive body weight are risk factors for the development of CrCLD. As a pet owner, you have the ability to reduce these risk factors by making sure your pet receives regular exercise and proper diet to maintain healthy weight.

Use this chart to observe your pet’s body shape. (Click to enlarge.)

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PetMD offers an online Healthy Weight Calculator to help owners keep track of their pet’s weight.

If you feel your dog is overweight or you need extra assistance in maintaining a healthy weight, contact your primary care veterinarian. They can design an exercise routine and diet to help your pet achieve a healthy weight.

Maintain a schedule of regular general health evaluations with your primary care veterinarian in order to increase the chance of early detection of any disease process (orthopedic or otherwise) that could potentially adversely affect muscle, tendon and ligament strength.   

If you see any symptoms or signs of CCL injury, contact your veterinarian right away. 

And remember, consultations with any of The COVE’s specialists, including our board-certified surgeon, Dr. Jeff Stallings, are accepted by referral from your primary care veterinarian and by appointment. Please call 757-935-9111 to schedule at your earliest convenience. 

For more information on CrCLD, please visit the American College of Veterinary Surgeons (ACVS) webpage on Cranial Cruciate Ligament Disease.  

 



Category: Pet Health Tips