EEwas taking guard off conveyor. As he stepped down 12"", he twisted left knee. EE refused treatment at that time. On 6/26/06 employer made employee go to DR. Determined possible meniscus tear. MRI was done. On 7/3/06 he went to orthopedic. He received by mail notice of surgery scheduled for 7/20/06. As of 7/12/06 ee has performed his regular duties without medication.