[Osteoarthritis of knee joint--standard concept and diagnosis]

Osteoarthritis of knee joint is the disease that can be easily found at the ordinary examination. The aging and the continuous long-term stress are the most important ones among the many kind of causing factors. Most of osteoarthritis is appeared in medial femorotibial joint. The second largest number of osteoarthritis is appeared in patellofemoral joint. The first appearance of the disease is over forty and the number of the patients increases as patients grow older. Patients are almost female. Complication of osteoarthritis is obesity and varix of the lower limbs. 85% of the Japanese patients have varus deformity but few have valgus deformity. Main symptom is is pain that can be treated conservatively by medication and physical therapy. Medical care and the following effect are differ from the existence of injury of meniscus and ligament, and the level of the disease.