Osteoarthritis（OA）is one of the most common joint disorders. OAseriously threatens human health and life, it has been an important subject of orthopaedic science. Although the investment in the early treatment of osteoarthritis and inhibiting the developing direction is largerin the past20 years, it has not obtained great progress in drug treatment. In spite of thearticular cartilage of physiology, biochemistry and metabolism of chondrocyte have a certain understanding, but the etiology and pathogenesis of osteoarthritis is still not very clear. So for, its early diagnosis and treatment of the lack of a clear direction. The pathogenesis of osteoarthritis is caused by a variety of factors, including genetic heritage, biomechanical factors, cartilage nutritional and metabolic abnormalities, chondrocyte apoptosis, etc. Now, in this paper we reviewed the pathogenesis of osteoarthritis from the structure of the articular cartilage, cytokines theory, theory of free radicals, miRNA and STAT3.
