EE WAS USING A 5' PRY BAR TO FREE AN OLD LINER FROM A 4 1/2' SHORT HEAD MANTLE. THE PRY BAR SLIPPED & THE EE LOST HIS BALANCE. WHILE STEPPING BACKWARDS TO CATCH HIS BALANCE, HIS LEG TURNED & A S THIS HAPPENED HE FELT A SNAP IN HIS LOWER LEFTLEG. AT THAT TIME, HE FELL TO THE GROUND. SURGERY WAS REQUIRED BUT NO MEDICAL REPORTS HAVE BEEN RECEIVED AT THIS TIME.