Frequently Asked Questions • Metal on Metal Joint Replacement • Managing Arthritis Why does my knee or hip hurt? As the layer of cartilage wears away, bone begins to rub against bone, which causes the discomfort and stiffness commonly associated with arthritis. What is total knee replacement? A total knee replacement is really a cartilage replacement with an artificial surface. The knee itself is not replaced, only the cartilage on the ends of the bones. The replacement implants create a new, smoothly functioning joint that prevents painful bone-on-bone contact. What is total hip replacement? A total hip replacement removes the arthritic ball of the upper thighbone as well as the damaged cartilage from the hip socket. The replacement implants create a new, smoothly functioning joint that prevents painful bone-on-bone contact. When should I have this type of surgery? Dr. Schmaltz and his team will decide if you are a candidate for this surgery. Their decision will be based on your history, exam, and X-rays. The doctors will ask you to decide if your discomfort, stiffness, and disability justify undergoing surgery. There is no harm in waiting to have surgery if conservative, non-operative methods can adequately control your discomfort. Am I too old for this surgery? Age is not a problem if you are in reasonable good health and have the desire to continue living a productive, active life. You may ask to see your personal physician for an opinion about your general health and readiness for surgery.