Ankle Arthroplasty: Indications, Alignment, Stability and Gain in Mobility

Abstract

There were several reasons for the failures of the first-generation ankle arthroplasty. The indication were not clear and the incidence of prosthetic loosening was rather high in some constrained devices [1, 2, 3]. With other designs, the spheroid types, the kinematics of the ankle joint were entirely dependent on the ligament structures [4, 5]. Such prostheses’ inability to correct deformities and produce stable and cylindrical mobility in the ankle joint were generally the problems. Calderale and Pipino [6] and Pappas et al. [7] were the first to describe biomechanical features of ankle prosthesis. The principles were: (1) to preserve the axis of the ankle joint, (2) to ley the prosthesis be as anatomical as possible, (3) to avoid constrained designs, and (4) to get cylindrical motion. These Principles have been followed in the Scandinavian total ankle replacement (STAR) prosthesis. Furthermore, as the ankle joint is a three-compartmental joint, the joint spaces between the medial-and lateral-talus facets and the malleoli must be addressed.