Revision Surgery for Metal Component Failure in Total Ankle Arthroplasty

Abstract

Category: Ankle Arthritis Introduction/Purpose: Metal component failure in total ankle arthroplasty(TAA) is difficult to treat. Traditionally, to an arthrodesis has been advocated. Revision TAA surgery has become more and more common with availability of revision implants and refinement of bone conserving primary implants. It this study, patient reported results and clinical outcomes are analyzed for patients undergoing revision total ankle arthroplasty. Methods: We retrospectively reviewed prospectively collected data on 45 patients (cases) with a mean age of 63.7 +/-10.2 years who developed loosening or collapse of either major metal component in the primary total ankle arthroplasty. Cases of isolated polyethylene exchange, infection, or extra-articular realignment procedures were excluded. Prospectively collected patient reported outcomes measures including the American Orthopaedic Foot and Ankle Society(AOFAS) hindfoot score, Visual Analog Scale (VAS), Short Form 36 (SF-36), Short Musculoskeletal Function Assessment (SMFA), and the Foot and Ankle Outcomes Score (FAOS) questionnaires were collected. Clinical data was collected through thorough review of the electronic medical record to identify clinical failure defined as explant and second revision or conversion to arthrodesis or amputation. Results: The causes of failure of primary TAA in this study were aseptic loosening of both components (40%), talar component subsidence/loosening (37.7%), tibial loosening (8.8%), coronal talar subluxation (8.8%) and talar malrotation (2.2%). Twenty-four patients (53.3%) underwent revision of all components, nineteen (42.2%) just the talar and polyethylene components, and two (4.4%) the tibial and polyethylene components. The average time to revision was 5.56 years +/- 5.71 with a follow-up of 3.02 years +/- 1.25 after revision. Ten (22.2%) revision arthroplasties required further surgery; five required conversion to arthrodesis and five required second revision TAA. VAS scores, SF36 scores, SMFA scores, AOFAS Hindfoot scores, and FAOS all improved after revision surgery but took 2 years to reach scores comparable to 1 year after primary TAA. Conclusion: Clinical and patient reported results of revision ankle arthroplasty after metal component failure were comparable to those after primary ankle arthroplasty. In our series, 22.2% of revision TAAs required a second revision TAA or arthrodesis surgery. Various prosthesis performed similarly when used in revision scenarios. Patients recovered faster from primary ankle arthroplasty when compared to revision ankle arthroplasty but all scores were comparable by the two-year follow-up visit after revision arthroplasty surgery.