EE stated that his left knee was bothering him on 12/9/2015 as he walked. He reported this to his supervisor on 12/13/2015. He continued to work until he had surgery on his left knee on 3/1/2016. This is being reported as an occupational illness. Attached MRI noted degenerative chondromalacia and degenerative meniscal deficiency. Additional medical information is attached.