Early Clinical, Radiographic, and Patient-Reported Outcomes of the Infinity with Adaptis Total Ankle System

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: The Infinity with Adaptis Total Ankle System (Stryker, Mahwah, NJ) is a low-profile, fixed-bearing implant that became available for use in October 2019. The aim of this study was to describe the early survivorship, clinical, and radiographic outcomes of the Infinity with Adaptis implant at minimum 2-year follow-up. Methods: A retrospective review of prospectively collected data within an institutional total ankle replacement (TAR) patient registry was performed. All patients who underwent primary total ankle arthroplasty (TAA) with the Infinity with Adaptis Total Ankle System between November 2019 to November 2021 at a single institution were identified. Chart review was performed to identify complications, reoperations, and revision procedures. Pre-operative and post-operative radiographs were measured to assess tibiotalar alignment and identify periprosthetic lucencies, cysts, or subsidence. Patient-Reported Outcomes Measurement Information System (PROMIS) scores were collected pre-operatively and at 1- and 2-years post-operatively to assess clinical outcomes. Of the 71 ankles that underwent a primary TAR with the Infinity with Adaptis between November 2019 and November 2021, 52 (73%) met inclusion criteria and were included in analysis. Results: At final follow-up (average 2.7 + 0.6 years), 49 of the 52 ankles in the cohort survived (94.2%). Three ankles were revised within 1.5 years of the index procedure (one talar component loosening and two infections). There were an additional 6 reoperations at an average of 16.4 (range: 1.1 – 37.1) months post-operative. Patients demonstrated both clinically and statistically significant improvements in the domains of Physical Function, Pain Interference, Pain Intensity, and Global Physical Health from pre-operative scores to 1-year post-operative scores (p < 0.0001). There was no statistically significant improvement in scores from 1- to 2-years post-operatively. There was improvement in radiographic alignment from the pre-operative to post-operative radiographs, with no significant change in alignment between first and last post-operative follow-up (p > 0.05). Conclusion: Patients who underwent total ankle arthroplasty with the Infinity with Adaptis Total Ankle Replacement demonstrated significant improvements in radiographic and clinical outcomes at a minimum of 2-year follow-up. The overall implant survival rate was 94.2%.