Introduction: Large bone defects such as those encountered after failed total ankle replacement have previously been a relative contraindication to revision ankle replacement due to inadequate bone stock. We describe our experience and patient reported outcomes with a modular ankle replacement system with tibial and talar augments.
Methods: This is a retrospective case series analysis of patients who underwent a total ankle replacement using the INVISION system across 2 centers between 2016 and 2022. Patients completed the Manchester-Oxford Foot Questionnaire (MOXFQ), Ankle Osteoarthritis Scale (AOS), and EQ-5D pre-operatively and then post-operatively at 6 months, 1 year, 2 years, 3 years, and 5 years. Medical records were reviewed for complications and re-operations. X-rays were reviewed for lucencies and alignment.
Results: A total of 17 patients were included in the study; 14 men and 3 women with an average age at the time of surgery of 67.9 years (range 56-80 years). The average follow-up post-operatively was 40.5 months (range 7-78) at the time of this study. The indication for surgery was revision of failed total ankle replacement (TAR) in 16 and revision of failed ankle fusion in 1. An augmented tibia was used in 13, an augmented talus in 13, and both augmented tibia and talus in 9 cases. There were no early surgical complications. One patient required debridement and implant retention for late deep infection. No implants have been revised. The average MOXFQ score improved by 19.3 points at most recent follow-up. The average AOS score improved by 25.2 points.
Conclusion: The early results of a modular augmented ankle arthroplasty system have shown satisfactory patient outcomes with a low complication and re-operation rate and present another option for patients with larger bone defects. This is a small series, and a larger series with long-term follow-up would be beneficial.
Levels of evidence: Level IV: Case series.
Keywords: arthritis and joint disease; comorbid conditions heel–rearfoot–ankle implant arthroplasty; diagnostic and therapeutic techniques reconstructive foot and ankle surgery; diagnostic and therapeutic techniques unstable ankle; heel–rearfoot–ankle.