Penile fracture refers to an injury of the penis where there is a rupture in one of the fibrous openings of the corposa cavenosa, the cavernous muscle of the penis. Injury is caused by blunt force trauma, usually from rapid movement during vaginal sex or masturbation. It is preceded by a cracking sound, which is immediately followed by a loss of erection. The man may also experience skin hematoma and temporary flaccidity.