How can I tell if my dog has a CCL injury?
There are a couple of methods Dr. Simon uses when determining if your dog has injured their cranial cruciate ligament (CCL; equivalent to the ACL in humans). Today, we are going cover two of those methods using joint stability tests, which you can also try on your dog at home.
Keep in mind that it takes a lot of practice to interpret what you are observing during these tests as the movements can be very subtle. So it’s okay if you’re not sure what you’re looking at – that’s why we have veterinary surgeons like Dr. Simon to do it for us.
In addition, these tests are just one of several ways to evaluate your dog’s knee - even if the stifle joint feels stable, there is a chance that your dog may still have a CCL injury.
For these reasons, we always recommend scheduling a consultation at Simon Veterinary Surgical so Dr. Simon can perform a full physical exam, take x-rays of the joint, and make her informed recommendation.
Okay, now that we have our disclaimer out of the way, let’s get started 😉
The CCL is an important ligament your dog’s stifle joint (knee), which prevents the tibia (shin bone) from moving in front of the femur (thigh bone). We often see the CCL injured in one of two ways:
Degeneration. As dogs gets older, their CCL undergoes progressive changes that weaken it, increasing the risk of a rupture.
Trauma. The CCL also may tear if a dog happens to position their stifle in exactly the right (or wrong 🤷) way when force is applied. As such, we often see trauma-related CCL injuries in very active dogs.
So now that we know that the CCL keeps the joint stable, it makes sense that our joint stability tests are meant to answer this one question: is the CCL doing its job?
Tibial Compression Test
This test mimics the strain placed on the stifle joint when the dog puts weight on their leg. We look for a ‘thrust’ motion, indicating that the femur is sliding over the tibia, and as you can imagine, this bone-on-bone contact is very painful.
This test can be done while your dog is either standing, lying on their side, or lying on their back.
With one hand:
Place your index finger and thumb on the sides of the distal femur bone above the stifle joint.
Hold: Keep the stifle joint positioned in a neutral standing angle, not fully flexed or fully extended
With the other hand:
Hold the leg right below the hock joint (ankle)
Action: Flex the hock toward the stifle to simulate weight-bearing
What to look for: If there is a CCL tear, this force will noticeably shift the tibia cranial relative to the femur - in other words, you will see the bone beneath the knee joint shift in the direction of the dog’s head.
Cranial Drawer Test
This test is a bit more passive (and less painful) than the Tibial Compression Test since it does not mimic a natural movement of the joint. However, it does help up further confirm joint instability when ‘drawer’ motion is observed.
Have your dog lie on their side while you perform this test
With one hand:
Place your index finger firmly on the patella (knee cap)
Place your thumb behind knee at the base of the femur
Hold: The stifle can be held at any angle - extended, flexed, or neutral – but be sure to keep this hand stationary
With the other hand:
Place your index finger on the crest (top front) of the tibia
Place your thumb behind the fibular head (top of the small bone located behind the tibia)
Action: Move the tibia cranially (in the directions of the dog’s head) and caudally (in the directions of the dog’s tail)
What to look for: If there is a CCL tear, there will be obvious cranial linear movement of the tibia and an indistinct, ill-defined end-point. Partial CCL tears often show cranial drawer instability only when the stifle is flexed. If your pup is still growing, you might notice "puppy laxity" in the joint, where the tibia can move a few millimeters cranial and caudal tibial with crisp and distinct endpoints.
Okay, so you’ve done these test at home – now what?
It takes a trained eye to look for the subtle movements in these tests. If you suspect that your dog has a CCL injury or if they are favoring one of their hind legs, we always suggest scheduling a consultation with Dr. Simon.
If your dog has already had a TPLO surgery, you can also check our blog “My dog just has a TPLO – did it work?” to how to interpret these joint stability test following the procedure.
Ready to schedule your consultation? Give us a call or send us a message today!
(310) 402-3573
info@simonvetsurgical.com
