It is important to evaluate follow-up radiographs for periprosthetic lucency, lysis, and component migration or subsidence. Subsidence at the talus is especially important to detect early. The case above is from a bone survey, so we don't have a lateral view, but there is suggestion of talar subsidence on the frontal view.
Because it is the oldest system in use, long term follow-up data are available for the Agility, and the majority don't seem to be good. A recent study of 41 patients with the Agility, for example, found that almost 40% needed revision surgery at some point (follow-up period of 6 months to 11 years), with an average time to revision surgery of 4 years. In addition, the authors found that patients without revisions reported only moderate pain relief and function.
A systematic review of all ankle arthroplasties found that revision rates published in clinical studies were about half the value found in registries, possibly because of the over-representation of publications by implant developers (almost 50% of the published content), who tended to report better results.
- Criswell BJ, Douglas K, Naik R, Thomson AB. High Revision and Reoperation Rates Using the Agility(TM) Total Ankle System. Clin Orthop Relat Res. 2012 Jan 24.
- Kopp FJ, Patel MM, Deland JT, O'Malley MJ. Total ankle arthroplasty with the Agility prosthesis: clinical and radiographic evaluation. Foot Ankle Int. 2006 Feb;27(2):97-103.
- Labek G, Klaus H, Schlichtherle R, Williams A, Agreiter M. Revision rates after total ankle arthroplasty in sample-based clinical studies and national registries. Foot Ankle Int. 2011 Aug;32(8):740-5.