Revision Rates after Total Ankle Arthroplasty in Sample-Based Clinical Studies and National Registries

Abstract

The aim of this study was to evaluate the outcome of specific implants in total ankle arthroplasty as reported in clinical studies and determined by national registries. A structured literature review was conducted regarding sample-based clinical studies and national registry data. To allow for comparative analyses, registry data had to be available for the implants included. These were STAR Ankle, Büchel-Pappas, Hintegra, Mobility, Agility, and Ramses Total Ankle Arthroplasty. The revision rate was used as the main outcome parameter. On average, the revision rates published in sample-based clinical studies were about half the value found in registries. Implant developers represent a share of almost 50% of the published content and are therefore over-represented in scientific publications. The inventors of STAR Ankle and BP total ankle implants published data which was statistically significantly superior to the outcome achieved in average patients as documented in registries. Irrespective of the implant, the average revision rate to be expected according to the registry data available is 21.8% after 5 years, and 43.5% after 10 years. The average revision rate published in peer-reviewed scientific articles was significantly lower than the outcome achieved according to national arthroplasty registry data, which reflect actual average patient care in the respective countries. Publications by some research groups, particularly by implant inventors, show a deviation from the outcome published by other users and those shown in registry data.