When knee replacements began to be used in the early ‘70s it was the common thinking that they would last maybe 10 years before needing to be replaced. For this reason, knee replacements were commonly only used for elderly patients. Over the years, there have been huge technological advancements in a wide variety of areas. Even though many improvements have occurred in surgical technique alone, it is not the only area which has undergone major changes. For instance there have been many improvements and advancements in the materials, design and fixation which have occurred which all work together to increase the durability of any type of joint replacement. In some patients, an orthopedic surgeon placed the knee prostheses as long ago as 30 to 40 years. But how long a knee replacement lasts varies greatly from one patient to another depending on many factors.