Until recently, a total knee replacement was the operation provided for painful knee arthritis. This operation replaced all mobile surfaces of the native knee with artificial, smooth articulating surfaces - whether they needed it or not! Now, the gold standard is to KEEP THE PARTS OF YOUR KNEE THAT ARE NORMAL and only replace those parts with damaged cartilage. This is a picture of a partial knee replacement used for patients who have only the inner portion (medial) knee arthritis. This results in much less surgical trauma, keeping the ligaments and bone that's normal, shorter hospital stays and easier rehabilitation.