Short- to Midterm Follow-up of Cemented Total Ankle Replacement Using the INBONE II: A Retrospective Chart Review

Background: Total ankle arthroplasty is a viable option for the treatment of end stage ankle arthritis. The purpose of this study is to report on the mid-term results with a cemented total ankle prosthesis, the Inbone™ II implant over a 5 year period. Methods: A retrospective, single-center chart and radiographic review of all patients with end stage ankle arthritis treated with Inbone™ II TAR) as the primary index procedure from 12/1/2012 to 3/1/2017. Clinical data were evaluated at 3 month, 6 month, 1 year and subsequent intervals for the study period. Preoperative diagnosis, pertinent patient demographics adjunctive procedures, implant associated complications, subsequent surgeries, and revisions were recorded. Results: 121 total ankles met our inclusion criteria. Patients had an INBONE™ II TAR implant placed with bone cement with a minimum of a 12 months follow up. Average age was 62.88 (range, 32-87) years, average body mass index was 32.74 (range, 21.8-56.04) kg/m2 and average follow up was 28.51(range, 12-69) months. Using the COFAS complication classification there were 14 minor, 11 moderate, and 5 major complications. 6/121 (5.0%) revisions which included: polyethylene exchange, device explant/fusion, and antibiotic spacer in situ. No complications over the course of this study ended in amputation. Conclusion: Total Ankle Arthroplasty utilizing the cemented INBONE™ II yielded good midterm results with regards to minor, moderate, and major complications. Rate of revision 6/121 (5.0%) was within the reported range with only 5 patients converted to fusion during the study period resulting in a 95% survivability at mid-term follow up.Levels of Evidence: Level IV: Retrospective case series.