Was the "panty bomber"...(ahem)...injured?

I saw a piece on the news tonight, where they discussed terrorists surgically implanting bombs into people who get on airplanes.

They made a reference to Umar Farouk Abdulmutallab, the infamous “underwear bomber”.

It crossed my mind that I never heard if he was injured by the misfire in his pants.

If he was, I am sure it was not pretty. Probably enough to make me wince. Not that he didn’t deserve it, but seriously…

But does anybody know exactly what physically happened to the guy?