Excess mortality in osteoarthritis

Osteoarthritis is the most common joint disorder worldwide. It comprises a group of overlapping disorders that may have different causes, but which result in joint failure subsequent to morphological changes in articular cartilage, subchondral bone, synovium, and other joint structures. Osteoarthritis typically affects the hands, knees, hips, spine, and feet.1 Although osteoarthritis can be defined pathologically, radiographically, or clinically, most epidemiological studies have relied upon radiographic features to characterise the disease. Radiographic features have a graded (although sometimes discordant) association with clinical features—joint pain and functional impairment—with notable disability arising from involvement of the knee and hip. The lifetime risk of osteoarthritis specific morbidity is about 25% for the hip2 and 45% for the knee,3 and the disorder is a major contributor to the 57 000 knee and 55 000 hip arthroplasties undertaken each year in the United Kingdom.4 In the linked study (doi:10.1136/bmj.d1165), Nüesch and colleagues assess all cause and disease specific mortality in patients with knee or hip osteoarthritis⇓.5