Ankle Joint Replacement Components

Total ankle replacement removes and then replaces both sides of the ankle joint with specially designed components, 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 DePuy Orthopaedics, Inc. of Warsaw, Indiana. The Agility™ LP Total Ankle System design is based on numerous research studies of the structure and mechanics of the ankle joint. The LP is a fourth generation design based on over 20 years of clinical experience in total ankle replacement.

Each artificial ankle prosthesis is made up of two parts:

• The tibial component is the metal portion of the joint replacement that replaces the socket of the ankle (the top portion).
• 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.

As with any medical treatment, individual results may vary. Only an orthopaedic surgeon can determine whether an orthopaedic implant is an appropriate course of treatment. There are potential risks, and recovery takes time. The performance of the new joint depends on weight, activity level, age and other factors. These need to be discussed with your doctor.

Last Updated: 10/23/2007