Revision of the Failed STAR Total Ankle Replacement

Abstract

The Scandinavian Total Ankle Replacement (STAR) is one of the most commonly implanted total ankle replacements globally. The STAR has been in clinical use in Europe since 1981 and in the United States since 2009. Clinical outcomes following total ankle replacement with the STAR prosthesis are good to excellent, but implant survivorship averages around 71 % at 10 years postoperatively. Implant failure is most commonly due to aseptic loosening, malalignment, deep infection, and polyethylene bearing fracture. Failure of the STAR prosthesis can be implementation related or design related. Poor bone quality, bone loss, ligamentous laxity, non-correctable deformity, and infection can all potentially compromise the outcome following total ankle replacement. The procedure has a high learning curve, and some characteristics of STAR prosthesis implantation may be especially challenging in the hands of an inexperienced surgeon. Various aspects of the STAR design may contribute to overloading and fracture of the polyethylene bearing. The relationship between the tibial surface and the polyethylene insert is unable to accommodate coronal plane motion, resulting in edge loading. The fixed curvature of the talar component may also lead to a mild ligament imbalance and edge loading.