What is the name for this knee injury or grinding in my knee?!

My doctor said the name of an injury/problem I have with my knee. She was pushing on it and felt the knee cap grinding and then told me the name.

I'm pretty sure it starts with the letter K. Something like krypto or kryo, or I'm not sure, but its it's a word that I hear a lot with elderly people and their joints I think. Thanks for any help.