Your Dog's Cranial Cruciate Ligament
The cranial cruciate ligament (CCL) is one of several ligaments located in your dog's knee. This band of tissue connects the femur to the tibia (the bones situated above and under the knee) and allows the knee to function.
This ligament has three main functions:
- Prevent cranial displacement of the tibia in relation to the femur (cranial drawer sign)
- Prevent hyperextension of the knee
- Prevent internal rotation of the tibia
This ligament is also the one most vulnerable to injury. A dog's CCL is similar to a human's anterior cruciate ligament (ACL). Like a person's ACL, the CCL can tear. A dog's cranial cruciate ligament can also rupture suddenly (acute rupture) or tear slowly, gradually worsening until a complete rupture happens.
What are signs of a torn CCL?
If you are present when the actual rupture occurs, the signs will be obvious. Since CCL tears are incredibly painful, most dogs will yelp, whine, or howl if this injury occurs.
However, not every dog is that outwardly expressive about injuries, especially if they are suffering from degenerative and chronic onset of joint disease.
Signs of a torn cranial cruciate ligament include:
- Limping in the hind legs
- Decreased physical activity
- Difficulty jumping or rising from the floor
- Sitting with one hind leg stuck out to the side
- Clicking sound when your dog walks
- Pain responses when you touch the injured stifle joint
- Joint inflammation
- Joint stiffness that is most noticeable when your dog is resting after physical activity
Most dogs with an injured CCL will be reluctant to bear weight on the injured leg.
Is a cranial cruciate ligament tear an emergency?
If you see any signs of an injured or torn CCL in your dog, it's important to have the condition treated as quickly as possible. Left untreated, CCL injuries only worsen over time and the symptoms become more pronounced and cause your dog severe pain.
If left alone, it may appear to improve over a week or two, but the knee will be notably swollen and arthritis can set in quickly.
To avoid walking on the injured knee, your dog may favor their healthy leg. Overcompensation can lead to the other knee becoming damaged along with the first. Many dogs with a single injury to the CCL go on to hurt the other knee, resulting in more pain and more necessary treatment, in addition to a longer recovery period.
Tibial Tuberosity Advancement (TTA) Surgery
Tibial tuberosity advancement surgery is less invasive than other types of surgical procedures that are sometimes used to treat a torn CCL, such as TPLO (Tibial Plateau Leveling Osteotomy) surgery.
When a vet or veterinary surgeon performs TTA surgery, the front portion of the tibia is cut and separated from the rest of the bone. A special orthopedic spacer is then screwed into the space between the tibia's two sections to move the front section forward and up.
This will shift the patellar ligament, which runs along the front of the knee, into better alignment and help prevent much of the abnormal sliding movement. Once this process is complete, the vet will attach a bone plate to hold the front section of the tibia in its proper position.
Tibial tuberosity advancement surgery is typically recommended for dogs with a steep tibial plateau (angle of the top section of the tibia). Your veterinarian will examine the geometry of your dog's knee to decide whether TTA surgery is the best surgical treatment option for your dog's torn CCL.
What's involved in TTA surgery for dogs?
Your veterinarian will assess your dog's knee to understand the extent of the CCL injury, its severity, and whether TTA surgery will be the most suitable treatment option. Your vet may do some of the following diagnostic tests to determine this:
- X-rays of the tibia and stifle (also taken to rule out other potential causes of hind-limb lameness and to gauge the extent of arthritis in the joint).
- Laboratory analysis of fluid drawn from the knee.
- Palpation of the knee. Your vet will feel the knee for cranial drawer motion. Though this procedure is not painful, your dog might be sedated or given light anesthesia if they are too tense to allow thorough palpation.
Patients with chronic ruptures associated with a large amount of arthritis and scar tissue may not display cranial drawer motion. Other signs of CCL rupture include thickening or scarring on the inside of the knee and tibial thrust (another method to check for cranial displacement of the tibia).
Hospital staff may schedule your dog's surgery on the same day these tests are done, or for a later date.
During the surgery, your dog will be sedated with anesthesia, and your vet will administer antibiotics and painkillers to your pooch during the procedure. The vet will clip your dog's limb from the level of their hip to the ankle. Before starting the surgery, the vet will make a small incision or cut in the knee to be able to inspect its internal structures. The damaged parts of the cartilage are then removed and any remaining ruptured ligaments will also be shortened.
X-rays will be taken once your pup's surgery is complete so the vet can evaluate the angle of the top of the shin bone (the tibial plateau) in relation to the patellar tendon and inspect the position of the implant.
After the surgery, a bandage may be applied to the surgical site. Patients will often stay in the hospital overnight, then go home the day after their TTA.
How Much Will My Dog's TTA Surgery Cost?
The cost of TTA surgery for dogs can differ significantly depending on:
- Your dog's size and weight
- The location of your vet clinic
- Which pre-surgical examinations and diagnostic tests may be required
- The expertise of the vet or veterinary surgeon performing the procedure, and
- What type of post-operative care and rehabilitation may be needed, including medications, follow-up visits, and physical therapy
After-Surgery Care
Your dog's rehabilitation after their surgery may take several months and it's imperative to follow the post-operative care instructions your vet gives you carefully. Your vet will prescribe a course of antibiotics and painkillers at the time your dog is sent home after their surgery. If your dog has a habit of licking their wound they may also need to wear an Elizabethan collar while the incision site heals.
You will need to visit your vet during the first couple of weeks following your dog's surgery so they can check in on the recovery process, as well as remove any sutures.
It's imperative to your dog's recovery that you restrict their activity and movements, limiting it to toiletry purposes only. You must keep them on a leash to prevent any running, stair climbing, and jumping. You must keep your pup in a small room or pen to prevent these movements when they are off their leash. After several weeks have passed, you may gradually increase your dog's activity and movement.
After approximately six to eight weeks have gone by since your pooch's procedure you will have a follow-up appointment with your veterinarian. At this visit, your vet will monitor the function of your dog's leg, take X-rays to assess the healing of the cut bone and provide you with advice about increasing your dog's daily activity. Additional tests and evaluations may be recommended based on your dog's individual case.
The Benefits of TTA Surgery in Dogs
There are a handful of benefits for dogs that have their torn CCL treated with Tibial Tuberosity Advancement surgery, including:
- Increased range of motion in the knee
- Faster healing time than with some other surgeries used to treat CCL tears
- 90% surgery success rate
- Dogs can return to their normal activities quicker
Risks of TTA Surgery
While the success rate in repairing CCL injuries with surgery is high and most dogs go on to make a smooth and complete recovery, there are several potential complications associated with TTA surgery, including:
- Infections
- Fractures
- Loosening implants
Another potential complication occurs in a very small percentage of dogs that have undergone TTA surgery without having injured cartilage, where they later go on to tear their CCL and require a second surgical procedure to have the torn cartilage removed.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.