Knee replacement surgery also known as knee arthroplasty arth row plas tee can help relieve pain and restore function in severely diseased knee joints. Knee replacement also called knee arthroplasty or total knee replacement is a surgical procedure to resurface a knee damaged by arthritis metal and plastic parts are used to cap the ends of the bones that form the knee joint along with the kneecap this surgery may be considered for someone who has severe arthritis or a severe knee injury. Most patients who undergo total knee replacement are age 50 to 80 but orthopaedic surgeons evaluate patients individually total knee replacements have been performed successfully at all ages from the young teenager with juvenile arthritis to the elderly patient with degenerative arthritis. Total knee arthroplasty tka is major surgery and usually performed under general or spinal anesthesia usually the surgery is completed within three hours depending upon the patients condition the surgeon monitors the patients vitals throughout the procedure