Abstract

Osteoarthritis (OA) is the most prevalent form of arthritis and a major cause of disability in people aged 65 and older. OA is not a single disease; rather, it is a group of overlapping yet distinct diseases with different etiologies but similar pathologic, morphologic, and clinical outcomes. OA occurs when the dynammic equilibrium between the breakdown and reapir of joint tissues is overwhelmed. Systemic and local biomechanical factors contribute to the development of the disease, with systemic factors also making the joint vulnerable and resulting in a greater impact of local joint factors. Systemic risk factors include ethnicity, gender, age, genetic factors, hormonal status, bone density, and nutritional factors. Local biomechanical factors include altered joint biomechanics, prior injuries, the effects of physical activities, sports participation, occupation, developmental abnormalities, and obesity. The normal joint is protected by biomechanical factors such as alignment and muscle strength, the lubrication provided by the synovial fluid, and the shock-absorbing function of bone and cartilage. When these functions are altered, changes occur at both the macroscopic and cellular levels, with derangements in any structure contributing to further joint destruction. 1) Further studies of both risk factor modification and cellular changes in OA will hopefully continue to enhance our understanding of this complex disease and lead to improved outcomes.

• Keywords: Osteoarthritis, Epidemiology, Risk factors, Pathophysiology