Makes me admire the professionalism, to be honest.
I dislocated my knee almost nine years ago now, and I haven't run, kicked a ball, or even walked properly since. I'm just too worried about it giving in again.
Even walking down steps, I go left foot on every step, because I don't want to risk putting pressure on my right and again seeing my leg at a hideous angle with my kneecap off to the side.