The knee joint takes on a fair amount of stress in everyday life. Going up and down stairs, walking, jogging, running and jumping are activities that further stress the knee. We usually face these activities on a daily basis. Over time, with activity and age factors, the knee can wear down. From a structural standpoint, your knee will not completely break down but small amounts of wear and tear may become noticeable, beginning with mild arthritis. As pressure increases on the tissue, more cartilage frays and further injury to the bone may take place. When the bone becomes more involved, the pain usually increases. It is when the pain becomes function limiting and less bearable during daily activities that a surgery may be necessary. The surgery type will be decided by you and your physician.