Total Ankle Arthroplasty vs Arthrodesis in an HbA_1c-Defined Diabetic Cohort: Lower 1- to 5-Year Structural Complication Rates in a Retrospective Propensity-Matched Study.

Abstract

Patients with diabetes are at increased risk for postoperative complications after ankle arthrodesis (AA) and total ankle arthroplasty (TAA), yet few studies directly compare outcomes between these procedures in a matched diabetic cohort. This study evaluates outcomes of TAA vs AA in patients with diabetes with end-stage ankle arthritis. We performed a retrospective cohort study using the TriNetX Research Network. Adults undergoing primary TAA (<i>Current Procedural Terminology</i> [<i>CPT</i>] 27702) or ankle arthrodesis (<i>CPT</i> 27870 or 29899) between 2005 and 2025 were included. Diabetes was defined by hemoglobin A_1c (HbA_1c) ≥6.5% recorded at any point within 1 year prior to surgery. Propensity score matching (1:1) was performed using demographic and clinical covariates. Outcomes included 1-year infection and 1-, 3-, and 5-year structural complications and emergency department (ED) visits. ED visits captured all-cause encounters rather than ankle-specific presentations. The pre-specified primary endpoint was 1-year structural complication; secondary endpoints included infection at 1 year and ED visits and structural complications at 3 and 5 years, with FDR applied to secondary outcomes. Risk estimates, Kaplan-Meier analyses, and Benjamini-Hochberg false discovery rate (FDR) correction were applied. After propensity score matching, 255 patients remained in each group. At 1 year, postoperative infection occurred in 5.5% of TAA patients and 9.4% of AA patients; this difference did not meet statistical significance after false discovery rate (FDR) adjustment. ED visits were more common in the AA cohort at 1, 3, and 5 years after FDR correction. Structural complications occurred more frequently in the AA cohort at 1 year (29.8% vs 15.3%; RR 0.51), 3 years (38.8% vs 20.0%; RR 0.52), and 5 years (39.6% vs 21.2%; RR 0.54), and these differences were statistically supported after FDR adjustment. In patients with a recorded HbA_1c ≥6.5% at any point within the previous year undergoing surgery for end-stage ankle arthritis, TAA demonstrated non-inferior structural complication rates across 1-, 3-, and 5-year follow-up without evidence of increased early infection risk after FDR adjustment.