EE WAS CLEARING CHUNKS OF MATERIAL OFF OF PIECE OF GRATING ON 7/20/03. EE'S RT. FOOT SLIPPED AS HE WAS LIFTING MATERIAL AND HE TWISTED HIS RIGHT KNEE. EE CONTINUED TO WORK HIS REG. WORK SHIFTS . EE CONTINUED TO EXPERIENCE PAIN IN HIS KNEE AREA & HAD KNEE EXAMINED BY ORTHO.SURGEON IN EARLY SEPT. 2003. EE UNDERWENT SURGERY TO REPAIR A TORN MINISCUS ON 9/5/03.