What type of knee dislocation is this?

two years ago in school i was sitting down and i turned around and my knee dislocated and i had to go to the emergency room, and while i was there i was laying on the bed and it went back into place, but it wasnt my knee cap and there was no visual dislocation because it was inside my leg and because the doctors didnt actually put it back in place, im still not sure what happend to my knee that day. also the same thing had happened once when i was younger, and also when it happened i could bend my leg inwards and close it but if i tried to extend it outwards the pain was crazy, also now im 16