Points on Total Ankle Arthroplasty

End-stage ankle arthritis is a painful and functionally limiting condition that can significantly worsen quality of life. Ankle arthrodesis, a common surgical procedure for ankle arthritis, provides good pain relief, patient satisfaction, and clinical outcomes when fusion is achieved. Potential disadvantages include malunion and nonunion, malalignment, limited range of motion (ROM), altered gait mechanics, and development of adjacent joint arthritis requiring reoperation. Over the past 2 decades, significant improvements in total ankle arthroplasty (TAA) surgical technique, implant design, surgeon training and education, and clinical outcomes have led to increased TAA popularity and use worldwide. Proposed advantages of TAA over arthrodesis include more normal joint ROM, superior gait kinematics, and decreased likelihood of subtalar arthritis, with equivalent pain relief and patient satisfaction. TAA has steadily gained acceptance as a safe, effective treatment option for ankle arthritis in select patient populations. In the United States from 2004 to 2009, the number of ankle fusions performed remained unchanged, but the number of TAAs increased by 57%, to 0.99 case per 10,000 patients. First-generation TAA implants had high failure rates at short-term follow-up because of nonanatomical designs, excessive bony resection, component malalignmemt, and improper soft-tissue balancing. Modern, secondand third-generation implants have improved features, including more anatomical designs, decreased bony resection, increased coronal and rotational stability, and enhanced modularity—decreasing tensile and shear forces at the bone–prosthesis interface and improving wear patterns. In a prospective, controlled, multicenter trial of the Scandinavian Total Ankle Replacement (STAR) 3-part mobile-bearing prosthesis (Small Bone Innovations, Morrisville, Pennsylvania), Saltzman and colleagues found that, compared with ankle arthrodesis, TAA had better functional outcomes and equivalent pain relief at 2-year followup. However, in a systematic review and meta-analysis of meniscal-bearing TAA implants, Stengel and colleagues found the rate of secondary surgery to be higher after TAA (12.5%) than after ankle arthrodesis. Brunner and colleagues reported long-term follow-up of the STAR prosthesis in a series of 62 TAAs with survival rates of 70.7% at 10 years and 45.6% at 14 years, with 38% of ankles requiring revision of at least 1 metallic component. Primary reasons for revision included aseptic loosening, talar component subsidence, progressive cyst formation, arthrofibrosis, and polyethylene insert fractures with an average time to revision of 7.4 years. A recent systematic review of 58 modern TAA implant studies (7942 TAAs) found an overall survivorship of 89% at 10 years with an annual failure rate of 1.2%. Overall, published survivorship data for TAA vary across studies, implant systems, and author-design teams and are influenced by surgeon familiarity with the procedure and surgeon case volume. In this review, we highlight 5 key TAA aspects that can help guide treatment and improve outcomes, and we provide supporting evidence from the literature.