In the past, they thought that a person must be sixty-five years old or at most sixty years old in order to be able to replace the knee joint, and the main reason for this is that the surgeries that are performed again were more difficult and the equipment was less. But the situation is different now, and we know that surgery can be performed at any age, but the patient must be aware, because he will have a longer life expectancy than when he is alive, and the probability that he will have to undergo another knee joint replacement surgery will be higher. For this reason, nowadays we can no longer keep the patient in pain and infirm until he reaches a certain age.