Torn Urethra. After a stunt slit open his urethra, “Jackass” bad boy Johnny Knoxville has had to stick an 11” catheter up in it twice a day, just to prevent the scar tissue from sealing it up for good. Or as he put it to Howard Stern, “It’s just like a dog’s chew toy down there. I broke my penis about three years ago trying to backflip a motorcycle. So that didn’t help its appearance—although it’s pretty cute.” Dang! But I guess after you’ve had your crotch paint-balled, had a sledge hammer swung at your dong, and ridden off the high-dive on a bicycle, nothing really phases you.