A Bit of Ankle Replacement History
A total ankle replacement is joint replacement surgery of the ankle joint. Total ankle replacements have been available for more than 30 years -- but early designs were failures. In the 1970s, ankle replacements were touted as promising -- but by the 1980s ankle replacements were rarely performed due to their high failure rate. More recently, ankle replacements have made a comeback. There are 5 ankle prostheses that have been FDA-approved and a couple of others under study in the United States.
According to the American Academy of Orthopedic Surgeons (AAOS), early ankle replacement designs had only two components and required bone cement to hold them in proper position. Newer designs don't require cement -- instead, bone grows into the ankle prosthesis similar to knee and hip replacements. Second-generation ankle implants are cement-less with a fixed (two-component design) or mobile (three-component design) polyethylene bearing.
Who Should Have an Ankle Replacement?
If you are experiencing severe ankle pain from arthritis, you may be a candidate for ankle replacement. The other surgical option is ankle fusion (arthrodesis). Ankle replacement allows you to retain more mobility and movement in the ankle compared to ankle fusion.
The downside is that not every patient is an appropriate candidate for ankle replacement. Patients with severely deformed or unstable ankles make ankle replacement an option that is less than ideal. Discuss your options with your doctors.
Types of Ankle Replacements
Your orthopedic surgeon has several options when choosing an ankle prosthesis for you. More detailed information exists about each one, including how many have been performed.
The Agility Ankle
The Agility Ankle by DePuy was FDA approved in May 2002. There is a tibial component and a talar component in the Agility Ankle. The tibial component consists of a metal piece and a plastic piece that support both the tibia and fibula by bridging the space between the two bones. The talar component of the implant sits in the talus bone in the foot and allows the foot to flex up and down. The Agility Ankle is designed to be used with bone cement.
The INBONE Total Ankle (formerly Topez Total Ankle Replacement System)
The INBONE Total Ankle is produced by Wright Technology. The FDA approved INBONE in November 2005. INBONE consists of two components -- a tibial component and a talar component. From their website, "The tibial component features a high-strength polyethylene piece secured within a titanium holder. A long titanium stem securely anchors this half of the implant within the tibia. The talar component is an anatomically shaped, highly polished cobalt chrome piece which also features a stem."
Eclipse Total Ankle Replacement
The Eclipse was FDA approved in November 2006. It has an upper tibial component and fixed polyethylene surface (a two-component design).
Salto Talaris Anatomic Ankle
The Salto Talaris Anatomic Ankle prosthesis was approved for marketing by the FDA in 2006. The Salto Talaris is a newly designed version of the Salto Ankle Prosthesis which had been implanted in Europe for the last 9 years. The Salto Talaris mimics the anatomy and flexion/extension movements of the natural ankle joint.
The STAR (Scandinavian Total Ankle Replacement)
The STAR was approved by the FDA on May 27, 2009. The STAR is the first mobile bearing, three component ankle marketed in the U.S. Mobile bearing ankles have been available in Europe for several years, but the FDA had been concerned with the safety and efficacy of STAR prior to its approval.
The Buechel-Pappas Device
The Buechel-Pappas ankle is not currently available in the U.S.. Read more about the Buechel-Pappas ankle and view photos.
The TNK ankle is not currently FDA approved. The TNK is a cementless, two-component, fixed-bearing device used almost exclusively in Japan.
Current Designs of Total Ankle Prostheses. Springer Vienna. December 2005.
Design Features of Current Total Ankle Replacements: Implants and Instrumentation. Journal of the Academy of Orthopedic Surgeons. Cracchiolo A. et al. September 2008.
Surgery Section - Total Ankle Replacement. Regence. 9/4/2007.