STAR® Total Ankle Replacements with BONIT® Coating: A Prospective 2-17 Year Follow-Up Study of 474 Ankles from a Single Center.

Background: Different coatings of the metal implants of STAR prostheses have been used since 1999. In Europe metal implants with a double calcium-phosphate coating (BONIT) on a titanium sprayed surface have been available since 1999.Methods: We present a 2-17 year follow-up of a consecutive series from a single center with 474 STAR ankle replacements where the BONIT type of coating has been used.Results: 55 prostheses (12%) have been revised, the majority of them due to fracture of the mobile bearing. 22 prostheses (5%) have been converted to an arthrodesis. Analysis of survival of the specific components showed an estimated 10-year survival rate of the tibia component, talus component and polyethylene mobile bearing of 99%, 98% and 84%, respectively. The corresponding estimated 15-year survival was 98%, 98% and 74%, respectively.Conclusion: This study showed an extraordinary high survival rate of the metal implants. Level of evidence: Level III, prospective cohort series.(c) 2023 The Author(s). Published by Elsevier Ltd on behalf of European Foot and Ankle Society. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).