STRUCTURAL CHANGES OF KNEE OSTEOARTHRITIS ARE PROGRESSED IN MIDDLE-AGED POPULATIONS WITH GRADE 0 OF KELLGREN-LAWRENCE CLASSIFICATION -THE OSTEOARTHRITIS INITIATIVE

Abstract

Purpose: Osteoarthritis of the knee (knee OA) is a slowly but progressive joint disease and is most common form of joint dysfunction and knee pain. Knee OA is also a major cause of morbidity and disability as well as a burden on health-care resources, especially for the elderly. As approximately 25% of populations aged 55 years of age or older have knee pain while walking, most of them is speculated to have knee OA. When we use radiography, it is estimated that approximately 25 million middle-aged and elderly populations have knee OA in Japan.