[Analysis of Musculoskeletal Systems and Their Diseases. Pathophysiology of articular cartilage and its new therapeutic targets].

Osteoarthritis (OA) is a group of heterogenetic disorders occurring due to a variety of causes, resulting in cartilage degeneration and finally in cartilage loss. No conservative drug therapy with high-quality evidence in terms of OA treatment has been developed as of yet. In recent years, the relation between OA and lifestyle related diseases along with the involvement of joint tissues other than the cartilage is becoming clarified through many epidemiological studies and basic researches. These topics are introduced in order to put new OA therapeutic targets into perspective. Moreover, problems in the evaluation for intraarticular injection of hyaluronic acid, which is a drug therapy used in medical practice for long term, are investigated and a discussion is carried out on the evaluation method of future drug therapies for OA.