What is a Luxating Patella and the Signs

Hey guys, Nikki lead veterinary technician with Posh Dog Knee Braces here.  Today, lets discuss what a luxating patella is, and what that means for our pups.  First off, a luxating patella simply means that the kneecap is not staying in the nice little happy groove that it was meant to on the femur.  There is a groove, like a valley, cut out in the femur, that the kneecap is supposed to stay inside.  A kneecap, or patella, is only supposed to glide in that grove up and down, as our pup bends the knee, just like our kneecaps do. 

Things to know about Luxating Patella

Unfortunately, due to sometimes genetics, this groove is too shallow for the kneecap to be happy and stay put.  Also, if the patient has a bow to the femur or leg, the tendon that holds the kneecap in place, makes that kneecap straight up and down.  Well, this causes an issue if our dog in fact has a crooked or bowed femur.

Certain breeds are more pre-disposed to this issue, and those would be most poodles, yorkies, chihuahua, bulldogs including smaller bulldog breeds, spaniels, terriers, and even some large breeds.  Some of the signs we will see is intermittent hind limb skipping, lameness, stretching the leg out behind them.  The more a kneecap moves out of place, the worse the issue gets. 

There are 4 grades of lameness for these guys.  Grade 1, the kneecap comes out of position, but is easily put back into place.  This usually does not cause an issue for the dog, and minor symptoms.  Grade 2 the kneecap shifts out of position with pressure, and can remain displaced until adjusted.  There may be damage to cartilage on these from moving out of place.  Grade 3, the kneecap is disjointed most of the time, but can be returned to normal position, however, once pressure is removed it luxates back out.  Dogs will exibit some lameness, and cartilage damage.  Grade 4, the kneecap is permanently dislodged from position, and can impair limb function.

Some dog’s with a luxating patella are more prone to having a CCL tear, and so we may suggest bracing them as a grade 2 or less, in order to help support the knee and take some pressure off the knee.  Bracing will not hold the kneecap in place, such as for a grade 3 or 4, but will provide some stabilizing of the joint itself, helping to prevent the CCL tear. 

Most grade 1 or 2 can be managed conservatively with supplements and rehab, possibly bracing.  Unfortunately, if the grade is 3 or above, sometimes they do need surgery to correct the issue, such as deepening that groove the kneecap sits on, or moving the actual tibial bone laterally, which makes the kneecap sit much better in the groove. 

If your dog does have surgery, it is recommended to brace post op, to restrict pressure on the knee, otherwise the patient must be restricted to a kennel or crate.  PT is really helpful as well.

Thank you, and please visit Poshdogkneebrace.com with any questions about Luxating Patella or you can visit our Facebook page.