Since the 1980s, ankle arthroplasty has been considered a dubious treatment for painful and degenerated joints. Many of the concerns that existed previously have been solved in the late-1990s. Prosthetic replacement of other joints also took a long time before reaching their present successful status. This text deals with ankle arthroplasty. International experts have given their opinion on the kinematics of the ankle; the basics of replacing the ankle joint; and the current status of several modern ankle-prosthesis designs. A better understanding of the ankle kinematics, alignment techniques and biological stabilization and the results of newer designs have changed the former attitude worldwide. The content of this book bears evidence for this change in opinion.