Nathan, someone told me about that the other day. He said if you had it when you were younger, it could pull the bone away slightly, then heal itself which causes calcified bone to be left there.
I don't ever recall having pains in my younger days, but I have a spur on both legs right under my knee caps.
I hate to knee walking. People don't understand the pain either.
They just tell you it will get better. This is just not true.
Anyway, check
here. The Adidas ones are really good. I use them for Brazilian Jiujitsu.