Knee replacement surgery, which can take 1 to 2 hours, has become so precise that doctors can choose from a variety of knee designs that suit your height, weight, and activity level. The implants, as they are called, are made from a variety of materials, including metal, ceramic, or plastic. They are built to allow easy movement. Some implants are made just for women to closely match their anatomy.
A common artificial knee design replaces the PCL (posterior cruciate ligament), located in the back of the knee. Another replaces the ACL (anterior cruciate ligament). Some artificial knees are designed for partial knee replacement, while others are built to keep the PCL and ACL right where they are.