Cylindrical total ankle joint replacement: surgical and biomechanical rationale.

Incongruent designs of total ankle arthroplasty are all unsatisfactory owing to inherently poor wear, deformation resistance, and poor stability. Several congruent designs are capable of providing good function. It is concluded that a cylindrical surface with a horizontal axis located at the center of curvature of the lateral border of the talar dome seems most desirable where adequate subtalar motion is present and a spherical type seems most desirable where such motion is not present. The "New Jersey" cylindrical total ankle arthroplasty using a cylindrical surface uses an ultrahigh molecular weight polyethylene talar component and a mortised cobalt-chromium alloy tibial component both stabilized with methylmethacrylate bone cement and dual fixation fins.