Abstract
Research Type:
Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies
Introduction/Purpose:
Total ankle arthroplasty (TAA) continues to grow in popularity however, the revision of failed implants remains challenging, in part due to the amount of bone resected during the index procedure. Various strategies for bridging this bony defect have been described, but no consensus has been reached regarding optimal management. The Agility Total Ankle Replacement (DePuy, Warsaw, IN) has some of the most established outcomes of any implant; however, also has a characteristic mode of failure that may exacerbate bony defects. Herein, we describe 45 revisions of failed Agility Total Ankle Replacements managed with either revision arthroplasty or structural allograft arthrodesis.
Methods:
This is a single-institution, retrospective cohort study of revised Agility total ankle arthroplasties from 2002 to 2023. Cases were identified using CPT codes (27703, 27704) and screened to include only those with a primary Agility total ankle arthroplasty. Forty-five unique ankles met these criteria. The average duration of follow-up was 61.7 months. The primary outcome was reoperation, defined as any unplanned procedure performed on the ipsilateral ankle due to implant complications. Collected variables included types of revision, reason for reoperation, and time to reoperation, among others. Statistical analyses were performed in SPSS using chi-square or unpaired t-test, as appropriate.
Results:
Search and screening yielded revisions of 45 unique Agility total ankle arthroplasties. Of these, 26 underwent revision total ankle arthroplasty, while 19 underwent revision to an arthrodesis. A total of 21 required a reoperation after their revision procedure. The relative risk of reoperation for revision arthroplasty compared to arthrodesis was 1.026 (95% CI: 0.314-3.359). The average time to reoperation of revision TAA and arthrodesis were 36.9 months and 24.8 months, respectively, however this difference did not reach statistical significance (p=0.637). Four revisions were performed for infection with three ankles undergoing revision to an arthrodesis and one ankle undergoing revision to an arthroplasty. Of these four patients, one patient from each revision strategy later underwent below knee amputation.
Conclusion:
Revision of failed total ankle arthroplasty remains a challenging procedure with a high rate of reoperation. Our study did not find a statistically significant difference in the incidence of or the time to reoperation between these two revision strategies. These findings are limited by low power and larger studies may uncover significant relationships. Our cohort had relatively few revisions for infection, and we were unable to assess superiority of one intervention over the other in this high-risk group. Patients undergoing revision of a total ankle arthroplasty should be counseled that additional procedures may be required in the future.