Patella luxation is a common problem, especially in small dogs, but it can cause issues in dogs of any size. Also referred to as slip knee, patella luxation can cause issues like cartilage damage, inflammation, pain, and even ligament tears. But by knowing how to recognize the signs of patella luxation in a dog and understanding what can be done about it, pet owners may be able to help protect their dog's knees.
What Are Luxating Patellas in Dogs?
Luxating patellas are knee caps that slip out of the groove that they are designed to stay in. The femur, which is the large upper leg bone, has a groove down the middle that the knee cap and its associated ligaments sits in. With patella luxation, the knee cap slides out of this groove in the leg bone, often because the groove is shallower than it should be. This problem can be evident in puppies as young as eight weeks old.1 Oftentimes, the patella will slip out and then back in, but in other cases, it will pop out and not want to go back into the groove. Luxations can occur either medially (towards the inside of the knee) or laterally (towards the outside of the knee) and in one or both legs.