Musculoskeletal disorders are the most common cause of severe long-term pain and physical disability, affecting hundreds of millions of people around the world. As the population ages, the extent of the problem will increase, placing huge burdens on societies and health-care systems. Osteoarthritis, the clinical syndrome of joint pain and dysfunction (i.e. loss of motion and mobility) caused by joint degeneration, affects more people than any other joint disease and ranks among the top ten causes of disability worldwide. The economic burden is high –musculoskeletal diseases cost the Canadian economy more than $17 billion per year. These costs are dominated by loss of productivity (due to disability) and hospital-care expenditures. The impact on the quality of life of affected Canadians is more difficult to quantify, but bone and joint diseases typically lead to reduction in activity, loss of employment, sleep disruption and depression.