The Effect of Age in Total Ankle Replacement

Abstract

Category: Ankle Introduction/Purpose: Over the last decades, total ankle replacement (TAR) emerged as a reliable treatment option in end-stage ankle osteoarthritis (OA) while preserving motion and physiological load. As these are strong arguments for TAR from an active patient’s perspective, it appears obvious that young patients show great interest in it. In the late 90s, 2nd generation implants showed a high revision rate, which has led to great cautiousness for TAR in young and active patients. Despite recently published data on 3rd generation implants showed a comparable outcome within different age groups, the question to debate remains whether TAR is advised in younger patients. The purpose of this study was to compare the clinical outcome and revision rate after TAR in patients younger and older than 50 years. Methods: A consecutive series of 813 primary TARs (3rd generation HINTEGRA, 446 male, 367 female), performed between May 2003 and December 2013, were enrolled. 129 patients (16%) were younger than 50 years and 784 (84%) were older than 50 years at time of surgery. The clinical outcome (AOFAS hindfoot score) and survivorship (revision of a metallic component as endpoint, or ankle fusion) of patients aged <50 years and ≥50 years at the time of surgery were compared. Results: Posttraumatic OA as indication for a TAR was more common in the younger cohort (81 vs. 78%) and the mean follow-up time was slightly longer (5.6 vs. 5.0 years). Younger patients had a significantly lower preoperative AOFAS score (39 vs. 44). Both groups showed an identical clinical improvement that resulted in a lower total AOFAS score (66 vs. 71) in the younger group at last follow-up. Overall, a total of 81 ankles (10%) were revised (13 patients <50 years, 68 patients ≥50 years). In 62 ankles (77%) a revision of a metallic component, in 19 ankles (23%) a conversion to ankle fusion was performed. The estimated 10-year revision rate was 15.7% for patients aged > 50 years and 18.4% for patients aged ≥ 50 years. Conclusion: Beside of the higher incidence of posttraumatic OA in younger cohort, the high activity level and biomechanical demands may lead to a greater subjective limitation, which explains their significantly lower baseline AOFAS score. However, both groups showed similar clinical improvement and overall revision rates. Our findings support and back up recently published data from 3rd generation TARs to be an effective and reliable treatment option in end-stage ankle OA in young patients. However, a long-term follow-up and individual analysis of all failures leading to revision is of high importance.