Osteoarthritis of the knee, or “wear and tear” deterioration in the knee joint, is a leading cause of knee pain. As a mobile and load-bearing joint, the knee is susceptible to trauma throughout life. Inflammatory diseases and infections can accelerate joint damage, and genetic and lifestyle factors also play a role. The biomechanical changes that occur as a result of cartilage loss add to loss of joint function and increasing pain. These changes may affect one or both knees to varying degrees.