mad men star was charged with viciously assaulting mark allen sanders in after 1990 hazing incident .
the freshman was hit so hard he suffered a fractured spine and nearly lost a kidney .
sanders alleged that he and his fellow pledges were subjected to ` repeated confinements ' in tiny compartments carved into the frat building 's basement .
the pledge listed hamm as one of his chief tormentors at the sigma nu fraternity at the university of texas at austin .
the future star ordered him to recite a six-page list of phrases pledges are told to memorize called the ` bulls *** list '
now 45 , sanders is a doctor and an attorney specializing in medical malpractice and personal injury .