Total ankle arthroplasty.

First-generation total ankle arthroplaty designs had unacceptably high complication and failure rates compared with ankle arthrodesis. More recent prostheses have had encouraging intermediate results because of refined surgical techniques and improved designs. Mobile-bearing designs theoretically offer less wear and loosening through full conformity and minimal constraint. The less complex fixed-bearing designs avoid bearing dislocation and the potential for added wear from a second articulation. Four second-generation designs have demonstrated reasonable functional outcomes: the Scandinavian Total Ankle Replacement, the Agility Ankle, the Buechel-Pappas Total Ankle Replacement, and the TNK ankle. Intermediate results are promising but should be interpreted with care.