One form of arthritis in the knee joint occurs because of degeneration of the cartilage in your knee. It commonly refers osteoarthritis to as “wear and tear” arthritis or degenerative arthritis and is the most common cause of total knee replacement surgery. Because of osteoarthritis, the cartilage in the knee breaks down over time and the result damages joint surface with bone rubbing on bone. This process may occur because of previous trauma to the joint, ligament instability, or abnormal stresses to the joint.