What really happened to Reids leg? He's been on crutches for a long time.

he was out with some of his cast mates from 500 days of summer and they decided to have a dance contest and matthew fell kinda funny and dislocated his knee. here's a link to the night it happened.
link

i was wondering that to so i looked it up and found an interview with matthew gray gubler the actor that plays him and he said that he was out at a bar with some friends they were having a wacky dance contest and well his won or lost how ever u want to look at it bt he messed up his knee really bad so he has to were a brace and use crutches for a little bit i think he said five months or something like that.