Survivorship and Long-term Results of Consecutive Series of 118 Hintegra Total Ankle Arthroplasties

CATEGORY: Ankle Arthritis INTRODUCTION/PURPOSE: Total ankle arthroplasty (TAA) has been more suggested to patients with end-stage ankle osteoarthritis. However, there were few studies which had investigated long-term clinical outcomes with mobile bearing system. The purpose of this study is to evaluate the long-term outcomes of total ankle arthroplasty with use of the Hintegra prosthesis and to identify prognostic factors that affect the outcome. METHODS: Between September 2004 and December 2009, 118 ankles underwent total ankle arthroplasty with Hintegra prosthesis. Clinical outcomes were assessed annually after operation using visual analog scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) scores, plain radiographs and re-operation. Kaplan-Meier survival plot showed survival outcomes of TAA in long-term follow-up. RESULTS: The mean follow-up period was 10.9 years (range 9.0-14.3). The mean change from baseline to final follow-up was -6.7 ± 4.3 points for VAS, and 26.1 ± 10.3 points for the AOFAS score. Three (2.5%) of the ankles required metal component revision at a mean of 2.9 ± 1.8 years (range, 0.5 to 5.8 years) after primary surgery. Five (4.2%) ankles underwent conversion to arthrodesis. Cystic osteolysis that needed surgery was 19 (16.1%) cases, most frequent lesion was posterior aspect of distal tibia. 65 ankles (55.1%) showed heterotopic ossifications but the degree of heterotopic ossification was not significantly correlated with VAS and AOFAS score. Revision with metal component as the end point of prosthesis was 86% at 10 years of follow up. CONCLUSION: Long term outcomes were satisfactory after mobile-bearing total ankle arthroplasty. Further study to elucidate possible reasons for osteolysis and subjective pain after TAA is warranted.