[Osteoarthritis--epidemiology, economics and quality of life]

Osteoarthritis (OA) is the most common form of arthritis and the most common indication for total hip and total knee replacement. It is an ageing-disorder which mostly affects distal interphalangeal joints, proximal interphalangeal joints, trapezo-metacarpal joints of the thumbs, knees and hips. Risk factors for the development and/or progression of OA identified in epidemiological studies can be broadly divided into systemic factors that increase the susceptibility to the disease and local biomechanical factors that influence the development of OA at the particular joint. It is estimated that costs associated with OA exceed 2% of the gross national product in developed countries. When it involves the hip and/or knee, OA accounts for more functional limitations and physical disability than any other chronic disease among adults.