Clinical and Radiographic Outcomes of Revision Total Ankle Arthroplasty Using an Intramedullary Referencing Implant

Abstract

Category: Ankle Arthritis Introduction/Purpose: Treatment of the failed total ankle arthroplasty (TAA) is challenging, and historically arthrodesis was advocated as the salvage treatment of choice. Currently, there is limited available literature reporting on options and outcomes of revision arthroplasty despite the persistent relatively high failure rate ranging from 10-23% within the first ten years after primary TAA. Early published outcomes of intramedullary-referencing implants for primary TAA have shown improvement in clinical outcomes and radiographic parameters, sustained correction of coronal deformity, and excellent survivorship with few associated complications. The purpose of this study is to report the clinical and radiographic outcomes of revision TAA using an intramedullary-referencing implant. Methods: We reviewed a consecutive series of 24 cases (14 female and 10 male; median age, 57.9 (28.2-74.6) years; median BMI, 31 (19.4-40.2)) between 2008 to 2015 in which a failed TAA underwent revision using InBone, an intramedullary-referencing, fixed-bearing, two-component total ankle system. Demographic, radiographic, and functional outcome data were collected preoperatively, immediately postoperatively, and at the most recent follow up. The primary outcome was implant survival defined by no reoperation for subsidence/loosening or revision of the implant. Secondary outcomes included radiographic (coronal and sagittal component alignment, osteolysis, and subsidence) and functional (American Orthopaedic Foot & Ankle Society [AOFAS] score and foot function index [FFI]) outcome data. Results: Twenty-four patients underwent revision TAA with intramedullary-referencing with 87.5% implant survival at average follow up of 30.4 months. Revision was performed most commonly for aseptic talar subsidence (45.8%) or implant loosening (tibia, 12.5%; talus, 16.7%). Following revision, three (12.5%) patients required reoperation for talar subsidence or loosening at average 37.7 months. Progression of osteolysis of the tibia, talus, and fibula was observed in 14 (58%), 4 (17%), and 6 (25%) of patients, respectively, although osteolysis was present preoperatively in 17 (70.1%), 9 (37.5%), and 10 (41.7%), respectively. Subsidence of the tibial and talar components was observed in 8 (33%) and 9 (38%) patients, respectively. Clinically, the average AOFAS and FFI score were 72 (57-100) and 27.1 (11.8-82.9), respectively. Conclusion: Early results of intramedullary-referencing revision TAA demonstrated improved patient-reported outcomes and maintenance of radiographic outcomes at an average follow-up of 30 months. Additionally, early results of revision arthroplasty after failed TAA were similar to those after primary arthroplasty. Aseptic talar subsidence or loosening were the main postoperative complications which required reoperation. Revision arthroplasty utilizing an intramedullary-referencing implant is a viable option for the failed TAA.