New developments in the epidemiology and risk factors for osteoarthritis.

Osteoarthritis (OA) is a common condition affecting nearly 600 million people worldwide, resulting in significant morbidity and disability. This paper reviews the latest updates on the systemic and local risk factors associated with development and progression of this disease. Some systemic risk factors, such as increasing age and obesity for example, have been well-established as strong risk factors for decades. Other potential risk factors such as smoking, nutritional deficiencies, and various medication exposures are less well-understood currently and require further investigation. The review of local risk factors focuses on congenital and acquired abnormalities that contribute to OA development such as joint malalignment, leg length discrepancy, and prior injury among others. This overview of OA risk factors highlights the importance of identifying modifiable risk factors as targets for treatment and progression-prevention in patients with OA as well as for the purpose of risk stratification and prevention in unaffected individuals.