Osteoarthritis, the most common joint disease, causes appreciable disability in a high percentage of older adults. Commonly attributed to progressive disruption of the articular cartilage and underlying bone structures constituting the joint, the condition can be extremely debilitating due to its widespread aversive consequences. Knee osteoarthritis (OA) is the most frequent localization of the arthrosis disease and the most common arthropathy of the knee, affecting over 37% of the population aged over 60 years and representing the main cause of pain and disability. In this book, Chapter One describes the most common less well documented psychological complications that can prevail in knee osteoarthritis, their implications, and possible solutions for reducing the extent and severity of this disabling condition. Chapter Two reviews biological pathways in knee osteoarthritis. Chapter Three discusses ozone therapy for management of OA.