My Husband Drilled Screw In His Left Knee Cap At

My husband drilled screw in his left knee cap at work. He couldn't pull it out himself. He had to reverse screw with the drill. Not much bleeding . But now there is Brown discoloration on side and on top of knee. There I 's swelling not knee but off the side of knee . It seems like fluid .
It seems his left foot is a little swollen as well . Don't know what he should do