The Infinity Total Ankle System

Abstract

Category: Ankle Arthritis Introduction/Purpose: Background: Increasing interest in 2-component total ankle arthroplasty (TAA) designs and the increased use of TAA overall has led to the development of a new generation of 2-component TAA implants. The first of these to become available was the Infinity Total Ankle System (Wright Medical Technology, Memphis, TN), introduced in 2014. Despite it currently being the most commonly used TAA implant in the UK and among the most commonly used in the USA, published clinical results are lacking. Purpose: This study presents the first report of the clinical and radiographic outcomes of the Infinity Total Ankle System with minimum 2 year follow-up Methods: The first 67 consecutive patients who underwent primary Infinity total ankle arthroplasty (TAA) at 2 North American sites between 2013 and 2015 were reviewed in a prospective observational study. Demographic, radiographic, and functional outcome data was collected preoperatively, at 6-12 months postoperatively, and annually thereafter. Results: The overall implant survival rate was 97% (65 of 67 implants) at mean follow up of 3 years (range 27-47 months). Two cases underwent talar component revision for aseptic loosening. Six of the 67 cases (9%) required a non-revision reoperation. Mean FFI and AOS scores at latest follow up improved from preoperative by 21.6 (p<0.0001) and 34.0 (p<0.0001), respectively. No radiographic loosening of any talar or tibial components was identified in the 65 non-revised cases. Conclusion: Early clinical and radiographic outcomes with the Infinity TAA are promising and compare favorably to those reported for both fixed- and mobile-bearing third generation TAA designs, even when used in cases with deformity and increased case complexity.