Total ankle replacement removes and then replaces both sides of the ankle joint with specially designed artificial parts, called prostheses. The tibial prosthesis consists of a polyethylene (medical grade plastic) and titanium base plate tray that is inserted into the tibia and fibula, giving the implant a wide base for support. The upper portion of the talus, the bone that moves up and down, is replaced with a component made of cobalt chromium alloy, a metal commonly used in joint replacement prostheses.
One type of ankle prosthesis is made by Salto Talaris (http://tornierankle.com/) . The Salto Talaris Total Ankle Prosthesis is modeled after the human anatomy and provides the ability to reproduce the natural movement of the ankle with a design that replicates the natural ankle.
Extensive work has been done to understand the normal anatomy of the ankle to reproduce it.
Each artificial ankle prosthesis is made up of two parts:
1) The tibial component is the metal portion of the artificial joint that replaces the socket of the ankle (the top portion).
2) The talus component replaces the top of the talus. The talus is the first bone of the foot and sits in the mortise of the ankle.
The talus component is made of metal. The tibial component is usually made up of two parts, a metal tray that is attached directly to the bone and a plastic cup that provides the bearing surface. The plastic used is very tough and very slick.
For more information about the ankle joint replacement, visit tornierankle.com.