Employee works at a surface shop of an underground mine. As he was getting in an end loader, he slipped and twisted to knee. He went to the dr and x ray were negative. H continued to work but the pain increase. He got an mri and it was postive for a small tear in his muscle. He had outpatient surgery on 3-17-06 and returnt to work on 3-20-06. He did not miss any schuled work.