There are lots of threads on y.t about it. I learned here so many yourkie have gone through it . I will do my best to explain. the knee has a little notch.. our babys are small the groves are small. some times they have to go in and make it bigger so it does not slip in and out. small breads get this(jumping) or just it doest grow good. now in Tedes case he is 16 months so the insurence says its genitic so they wont cover it.does that help
Im not a good explainer