Osteoarthritis

Primary osteoarthritis (OA) describes a common group of joint conditions in which cartilage and bone are affected. The sites most frequently affected are hand, knee, hip and spine. Risk factors include systemic features such as age, sex and race as well as local factors including joint alignment and muscle strength. Genes play an important role, with an estimated heritability of OA of 40–60%. Previously considered a ‘wear and tear’ condition, several lines of investigation now point to a low grade inflammatory component. This is important because treatment has largely been confined to palliation with analgesics and subsequent joint replacement. The possibility of effective disease modifying therapeutic agents is becoming likely in the near future.