With means for better mechanical stability and fixation, custom prostheses have improved our capabilities in salvaging failed total ankle replacements. Even in the primary total ankle replacement setting, previous contraindications due to suboptimal bony support may be adequately bypassed, and more patients may benefit from having a custom prosthesis. Accurate preoperative imaging and templating will ensure proper dimensions of the custom prosthesis. Intraoperative adjuncts such as screws, plates, and bone grafts will help address unexpected bone defects, coexisting adjacent joints arthritis, and other hindfoot and midfoot deformities. In this article, the authors discuss the history and problems of total ankle replacement failures, the surgical technique, and tips and pitfalls when using custom replacement prostheses.