The focus of osteoarthritis research has, for many years, been the biology of hyaline articular cartilage, whose loss is a central pathologic feature of this disease. However, cartilage has no pain fibers. Osteoarthritis, a condition which affects millions of people throughout the world, is a disease whose principal clinical manifestation is pain. Persons with disease have frequent pain especially with activity, develop disability because of this pain and seek health care to treat the pain. There is little in the literature to help the clinician understand the sources of this pain and how best to treat it. This book addresses this need. It brings together neuroscientists who study pain with osteoarthritis specialists. It provides an understanding of sources of pain in osteoarthritis and how best to treat this pain.