Cranial cruciate ligament (CCL) damage is one of the most common causes of hind leg lameness in dogs.
If your dog suddenly starts limping on their hind leg, particularly a large breed dog, the chances are they suffered a CCL injury. The essential thing to note, that without treatment, your dog’s knee will only become worse over time, developing arthritis and affecting the rest of your dog’s body as well as their quality of life.
It doesn’t mean, however, that every hind leg lameness means your dog hurt their knee. Other potential reasons your dog might become lame on a hind leg include:
- nail and pad injuries
- foreign bodies
- other soft tissue injuries
- hip dysplasia
- luxating patella
- inflammatory conditions
The knee joint is where the shin, thigh, and patella bones meet in the form of a hinge. It allows the dog to walk and run. If you ever wore a cast, you know how difficult it is to move around when the joint is immobilized.
The cranial cruciate ligament (CCL) is the equivalent of ACL in the human knee. CCL is one of two little ligaments inside the dog’s knee, or stifle, that contribute to the stabilization of the joint. I say contribute because there are other stabilizing structures in place. In fact, the CCL is supposed to be a backup, not the primary means of joint stabilization.
Further information: Ruptured Anterior (Cranial) Cruciate Ligament
Further reading: Hanging by a Thread? Stabilizing Forces in the Canine Stifle
Some of the factors that contribute to CCL injuries in dogs include:
- breed conformation
- metabolic issues
- hormonal inbalances
- gradual degradation
- poor physical condition
- early spay/neuter
While we believe we have it all figured out, it might not be so.
Does cruciate disease result from abnormal biomechanics on a normal ligament, normal biomechanics on an abnormal ligament, or a combination of both?Animal Medical Center of Southern California
Further information: Canine Cruciate Ligament Injury
However things arrive to that point, when the CCL ruptures, it allows the bones in the joint move beyond the range the knee was designed for. The result is pain, inflammation, and arthritis.
What does a CCL injury look like?
Common signs of cruciate ligament tears include:
- lameness/reduced weight bearing on the affected leg
- weight shifting
- an abnormal sitting position with one leg kicked out to a side rather than tucked in as normal
- swelling may or may not be present
- difficulty rising
- trouble or reluctance to jump
- reduced activity
- popping noise (if the meniscus is damaged)
Your veterinarian might discover other signs such as:
- reduced muscle mass/muscle atrophy
- decreased range of motion
A dog with a torn CCL will be hesitant to bear weight on the affected leg or he may not put that foot down at all.
Dr. Andy Roark’s Low-Down on Cruciate Ligament Tears
Diagnosing CCL injuries
Diagnosing CCL injuries is relatively straightforward and includes:
- physical examination
- gait and sitting stance observation
- joint manipulation (drawer sign)
- diagnostic imaging
Cruciate ligament tears in dogs rarely occur due to an acute trauma to a previously healthy knee. Rather, they are typically the result of gradual weakening and gradual degradation.
CCL tears can be either complete or partial.
More information: Dog CCL Injury Grading: Cruciate Tears “All or None, or Partial?”
One of the key parts of the diagnosis of a ruptured cruciate ligament is the demonstration of abnormal movement—drawer sign.
A healthy joint will not move in such a way. The failure to elicit the drawer sign, however, doesn’t meat the knee is unstable; some strong dogs might be able to resist. When repeated under sedation or anesthesia, it becomes apparent.
Treatment options for CCL injuries
So now that it has happened, what do you do? You have to do something. The thing about ligaments is that they don’t heal very well. With minor damage, regenerative therapy, along with other measures, might allow healing. Most of the time, however, the goal of treatment is to stabilize the knee by other means.
Treatment options depend on the degree of the tear, the dog’s overall condition and health, size, activity level and other factor.
Treatment options include:
- conservative management with or without brace
- physical therapy
- regenerative and cell therapies
I describe the various options in more detail in the articles linked below.
Whether or not conservative management is a viable option for you dog depends on several factors such as their
- age/activity level
- overall health/other medical conditions
- degree of damage
The best candidates for this approach are dogs who are:
- less than 30 pounds
- less active
Can regenerative medicine help treat CCL injuries in dogs?
There are two options to consider when looking for regenerative treatment for a partially torn cruciate ligament:
- stem cell therapy
- platelet-rich plasma therapy (PRP)
Some sport dogs orthopedic specialist like to combine the two.
If your dog is still young and is otherwise healthy, surgery might be the best option. We’ve been through this with Jasmine twice. It is heartbreaking, but I do believe it’s the best thing to do.
Which surgery to chose? In the past, surgeons attempted to replace the ligament. However, just as a torn ligament cannot heal, it cannot be easily replaced either. So that leaves us with joint stabilization techniques such as:
- extracapsular repair/suture technique
- TightRope stabilization
- Tibial plateau leveling osteotomy (TPLO)
- Cora-based leveling osteotomy (CBLO)
- Triple tibial osteotomy (TTO)
- Tibial tuberosity advancement (TTA)
- Simitri stable in stride stabilization (SSIS)
Which option is best for your dog depends on the dog. Which one is better – the answer depends on who you ask. Research your options thoroughly.
Most often though you’ll run into a surgeon who does and believes in one of them. Make sure your surgeon is comfortable with the chosen technique and has the experience and skill needed to do it well.
This is an older type of surgery, largely abandoned particularly for larger breeds. However, it can work under the right circumstances.
It is the least invasive technique. With a bit of luck, the sutures will keep the knee stable long enough for fibrous/scar tissue to develop. The scar tissue then stabilizes the knee effectively.
The TightRope stabilization technique was conceived as an improvement on the traditional suture repair.
They are both variations of the same idea.
The RightRope repair uses stronger material which is more of a cord than a suture and it anchors it through both the tibia and femur.
This technique didn’t seem to take root and it appears the initial excitement wore off.
Further information: CCL Tears TightRope Repair: My Two Cents on the TightRope® CCL Fixation System
TPLO has been considered the gold standard for the treatment of canine CCL tears. Does that make it the best option?
While I find it quite invasive, it does provide good stability when it’s done well.
I do feel that there is quite a bit of room for error, as well as it comes with inherent challenges that can lead to complications.
More information: Tibial Plateau Leveling Osteotomy: My Two Cents on TPLO Repair
CBLO is the next-generation TPLO. Veterinary surgeons were looking for ways to address issues that were causing potential complications in TPLO patients.
To me, the CBLO indeed looks much better thought-out and elegant.
At this time, however, it is a novelty surgery which might cause challenge both with availability and the level of surgeon’s experience.
More information: Cora-based Leveling Osteotomy: My Two Cents on CBLO Repair
Triple Tibial Osteotomy (TTO) in in my opinion a clever, sensible take on the CCL surgery and I liked it better than the TPLO and TTA. In fact, it is an improvement in form of a hybrid of the two.
In spite of that, it remains obscure and largely not available in North America.
Further information: Triple Tibial Osteotomy: My Two Cents on TTO Cruciate Repair
The Simitri Stable in Stride Stabilization is an emerging technique which is unique in its approach.
This surgery achieves stabilization by a hinge implant—you could think of it as a heavy-duty ligament replacement outside the knee joint.
Further information: Simitri Stable in Stride Stabilization: The Hinge Technique
The tibial tuberosity advancement (TTA) was one of the first modern surgical options to address cranial cruciate ligament tears in dogs.
The difference in the approach is that instead of changing the tibial plateau angle to achieve joint stabilization, TTA uses the strength of the patellar tendon.
The technique went through several evolutionary steps and improvements.
Further information: Tibial Tuberosity Advancement: My Two Cents on the TTA Repair
What happens after your dog’s surgery is just as important as the operation itself. Make no mistake—successful surgery is only half of the final outcome.
Exercise restrictions and physical rehabilitation are essential for your dog to regain normal function of the knee. Don’t let your surgeon send you home without a detailed post-op plan for your dog.
Physical therapy is paramount to your dog’s successful recovery from a CCL surgery.
You can work with a certified animal PT and with guidance, you can do some of the exercises at home.
Always consult with your surgeon about the type of exercises and their timing.
More information: Physical Therapy for Full CCL Tears
Given the fact that, in most cases, cruciate ligament tears are a result of a chronic process, the likelyhood of CCL tear in the second leg is high.
Not only that ligaments in both knees are likely to have weakened, the uninjured leg has to withstand additional weight-bearing while the dog is limping.
More information: Dog Knee Injuries: Why The Second CCL Often Goes Too
Preventing CCL injuries in dogs
There are measures you can take to minimize the risk, the most important of which is weight management. Effectively, when you review the list of contributing factors earlier, you can influence some of them.
Keeping your dog slim, fit, and healthy will help prevent injuries.
Is there a way to prevent cruciate ligament tears in dogs?
Achieve an optimal body condition score for your dog, keep them healthy and strong, and consider curbing activities that increase the risk of knee injuries.
Available data shows that the odds of CCL tears in dogs spayed and neutered before 6 months of age is seven-fold higher than in intact dogs.
For example, these dogs have significantly greater tibial plateau angle which is considered one of the anatomical risk factors.
Further information: CCL Tears And Early Spay And Neuter: Is There a Connection?
So you see there are choices. Each of them has its pro’s and cons. My main points here are, know your options, and do your homework. Always. One cannot make a good decision without information. Understand all your options, discuss them with your veterinarian or surgeon and then make a decision.
Don’t wait too long though, this is one of those problems that will not go away by being ignored. A delay will only cause additional problems down the line.