Almost 21 million people in the United States are afflicted by osteoarthritis and it accounts for nearly 25% of all visits to primary care physicians. Moreover, close to 50% of those 65 and older will develop symptoms of this disorder This issue of Rheumatic Disease Clinics of North America examines the clinically important aspects of osteoarthritis and features articles on the following topics: epidemiology; etiopathogenesis; the role of bone and...