Hey sports fans and pet lovers! Ever heard of an athlete tearing their ACL? It's a common and serious knee injury. Well, our dogs can get a very similar injury, but in dogs, it's called a cranial cruciate ligament (CCL) tear. It's one of the most common orthopedic injuries in dogs, so let's break down what it is and how we can get our furry athletes back on their feet!
What is the Cranial Cruciate Ligament (CCL)?
The CCL is a tough band of tissue inside the knee joint (or "stifle" in dogs) that connects the thigh bone (femur) to the shin bone (tibia). Its main job is to prevent the shin bone from sliding forward in relation to the thigh bone and to keep the knee stable. It's the doggy equivalent of the human ACL (anterior cruciate ligament).
A CCL injury can be a partial tear or a full rupture. Unlike in human athletes where the injury is often from a single traumatic event, in dogs, it's usually a degenerative process. The ligament slowly weakens and frays over time, and then one day, a simple activity like jumping off the couch can cause it to finally tear.
Spotting the Signs of a CCL Tear
The signs can be sudden or gradual, depending on whether it's a full rupture or a slow tear.
- •Sudden Lameness: This is the most common sign. Your dog might be running and playing, and then suddenly cry out and hold up a back leg.
- •"Toe-Touching": They might be very reluctant to put any weight on the leg, often just touching their toe to the ground.
- •Difficulty Rising: They may have trouble getting up from a sitting or lying position.
- •A Clicking or Popping Sound: You might hear a "pop" from the knee joint when it's injured.
- •Swelling: The knee joint may look swollen.
- •Muscle Atrophy: If the injury has been going on for a while, you might notice the muscles in the injured leg looking smaller.
A crucial point: If your dog tears the CCL in one knee, there's a 40-60% chance they will tear the one in the other knee within a couple of years.
What Causes a CCL to Tear?
- •Degeneration: As mentioned, it's usually a slow breakdown of the ligament over time.
- •Breed Predisposition: Certain breeds are much more prone to CCL tears, including Labradors, Rottweilers, Newfoundlands, and Staffordshire Terriers.
- •Weight: Overweight and obese dogs are at a much higher risk.
- •Conformation: The way a dog is built can put more stress on the CCL.
How Vets Diagnose a CCL Tear
Your vet will perform an orthopedic exam to check for instability in the knee. The key test is the "cranial drawer sign" or the "tibial thrust test." In these tests, your vet will manipulate the knee to see if the shin bone slides forward. If it does, the CCL is torn. This test might require sedation if your dog is very painful or tense.
X-rays are also essential. While they can't show the ligament itself, they can show signs of arthritis (which is almost always present with a CCL tear) and help to rule out other problems.
Treatment: Surgery is Usually the Answer
For all but the smallest dogs (under 20-25 lbs), surgery is the recommended treatment for a CCL tear. Without surgery, the knee will be unstable, leading to progressive, painful arthritis and a poor quality of life.
The goal of surgery is to stabilize the knee. There are several different surgical techniques, but the most common and effective ones change the geometry of the knee so that the CCL is no longer needed.
The Gold Standard Surgical Options:
- •Tibial Plateau Leveling Osteotomy (TPLO): This is one of the most popular procedures. The surgeon makes a curved cut in the top of the shin bone (the tibial plateau) and rotates it to change the angle of the joint. This prevents the shin bone from thrusting forward, making the knee stable when the dog bears weight. A plate and screws are used to hold the bone in place while it heals.
- •Tibial Tuberosity Advancement (TTA): In this procedure, the front part of the shin bone (the tibial tuberosity) is cut and moved forward. This changes the angle of the patellar tendon, which also stabilizes the knee.
Both TPLO and TTA have very high success rates (over 90%) and allow dogs to return to a very active, athletic life.
Other Surgical Options:
- •Extracapsular or Lateral Suture Repair: This technique uses a strong suture on the outside of the joint to mimic the function of the CCL. It can be a good option for smaller, less active dogs, but it's generally not as robust as TPLO or TTA for larger, more active dogs.
The Road to Recovery
Recovery from CCL surgery takes time and dedication. It involves 8-12 weeks of restricted activity, with a gradual return to normal function.
- •The first two weeks: Very strict rest, with only short, leashed potty walks.
- •Weeks 3-8: A gradual increase in controlled leash walks.
- •Physical Therapy: This is a critical part of recovery! It will include exercises to rebuild muscle and improve range of motion.
A CCL tear is a significant injury, but with modern veterinary surgery, the prognosis is excellent. With your commitment to their recovery, your furry athlete will be back to enjoying life to the fullest.
Sources & Further Reading:
- •American College of Veterinary Surgeons - Cranial Cruciate Ligament Disease
- 1VCA Animal Hospitals - Cranial Cruciate Ligament Disease in Dogs