Ten Year Subsequent Hindfoot Fusion Rates do not Differ Following Total Ankle Arthroplasty or Ankle Arthrodesis in a Large-Scale Database with Verified Continued Patient Enrollment

Abstract

Category: Hindfoot, Ankle Arthritis

Keywords: Wound Complications, Total Ankle Arthroplasty, Revision Ankle Arthroplasty

Introduction/Purpose: Total ankle arthroplasty (TAA) preserves motion, while ankle arthrodesis (AF) has historically been the gold standard for end-stage ankle arthritis. One potential advantage of ankle replacement over fusion is that it may reduce the risk of symptomatic hindfoot fusion requiring subsequent fusion, and this has been promoted as a relative benefit of the procedure. While limited small-scale data supports this contention, large-scale community-based data are missing. We sought to determine the relative rates of subsequent hindfoot fusion after both procedures using a large-scale commercial insurance database.

Methods: We performed a retrospective cohort study using the PearlDiver national claims database (2010– 2023). Patients undergoing primary TAA (CPT 27702) and AF (CPT 27870) were identified and included only if continuous enrollment for 10 or more years in the database was confirmed to ensure integrity of the data. Patients with Charcot/neuropathy, infection, tumor, or revision at the index were excluded. Subsequent hindfoot fusion (CPT 28725, 28715, 28705, 28730, 29907) was the primary endpoint. To exclude concomitant or staged procedures, we applied a 90-day exclusion period after the index procedure. Incidence rates were calculated, and Kaplan–Meier curves estimated fusion-free survival.

Results: Long-term claims data show that hindfoot fusion after TAA or AF is uncommon (<5% at 10 years), with similar incidence between procedures. The rate of subsequent hindfoot fusion of around 4% within 10 years after either TAA or AF highlights the durability of both procedures but failed to demonstrate an advantage for ankle replacement in this large-scale community database.

Conclusion: Long-term claims data show that hindfoot fusion after TAA or AF is uncommon (<5% at 10 years), with similar incidence between procedures. The rate of subsequent hindfoot fusion of around 4% within 10 years after either TAA or AF highlights the durability of both procedures but failed to demonstrate an advantage for ankle replacement in this large-scale community database.