Knee osteoarthritis is caused by chronic wear and tear, or trauma, or damage to the ligaments, resulting in thinning or complete worn out of the meniscus and articular cartilage. The changes can be measured or seen from X-ray or MRI pictures. Because of the loss of cushion and lubrication, the joint becomes very inflamed. The pain could be so severe, that patient has to stop exercising or take frequent breaks during walking or standing. Many patients could not enjoy out-door activities, dancing and playing with grandkids, etc.