EMPLOYEE WAS CLOSING LIDS ON TOP OF A RAIL CAR. LID HUNG UP ON ANOTHER LID AND EMPLOYEE FELT A PAIN BEHIND HIS LEFT KNEE. *PAIN WENT AWAY BEFORE NEXT SHIFT BUT RETURNED ON JUNE 30, 2004. WE RECEIVED NOTIFICATION ON 7/5/04 THAT THE EMPLOYEE HAD TORN CARTILEDGE & WOULD NEED SURGERY, MAKING THIS INCIDENT REPORTABLE.