Does Timing of Subtalar Arthrodesis Affect Reoperation or Revision Rates for Total Ankle Arthroplasty?
Authors: Ramamurti Pradip , Schwartz Joshua , Cooper M. Truitt , Park Joseph 
Published: April 2024

Introduction/Purpose: The incidence of primary total ankle arthroplasty (TAA) in the treatment of end-stage ankle arthritis has increased substantially over the last decade. TAA may be performed alone or in conjunction with additional procedures including subtalar (ST) or triple arthrodesis as end-stage ankle arthritis is often associated with degenerative disease affecting neighboring joints. Prior literature has demonstrated that the ipsilateral hindfoot arthrodesis may increase the risk for revision after TAA and that simultaneous ST arthrodesis with TAA could result in significant short term clinical and radiologic improvements. However, there is limited research comparing staged versus simultaneous hindfoot arthrodesis with concomitant TAA. The purpose of this study is to compare the reoperation rates after TAA with simultaneous hindfoot arthrodesis versus staged hindfoot arthrodesis followed by TAA. Methods: Patients who underwent primary TAA from 2015-2022 were identified in the PearlDiver database using international classification of diseases (ICD) and current procedural (CPT) codes. Patients were only selected if they contained 1-year database follow-up after the index TAA. Patients were sorted into three cohorts: (1) primary TAA without any history of hindfoot arthrodesis (control), (2) those with staged hindfoot arthrodesis prior to TAA, and (3) those with hindfoot arthrodesis at the same time as TAA. Demographic characteristics including age, gender, and Charlson Comorbidity Index (CCI) were assessed for each cohort. The 1-year rate of reoperation and revision were the primary outcomes of this study. Univariate analysis using chi- square tests and student T-tests were performed to analyze any differences in patient demographics, comorbidities, and complications. Multivariate analysis using logistic regression was subsequently conducted to account for any confounding variables and covariates. Results: 9,912 patients underwent TAA without prior hindfoot arthrodesis, 297 patients underwent TAA with prior hindfoot arthrodesis and 174 with hindfoot arthrodesis concurrently with TAA. The incidences of reoperation (OR 3.52, 12.6% vs. 3.9%, P<0.001) and revision (OR 3.66, 4.0% vs. 1.1%, P=0.001) were higher in the simultaneous cohort when compared to the control. However, there were no statistically significant differences in rates of reoperation (OR 0.96, 4.0% vs. 3.9%, P= 0.891) or revision (OR 1.94, 2.4% vs. 1.1 %, P= 0.095) when comparing staged hindfoot arthrodesis to the control. Conclusion: Patients undergoing concurrent hindfoot arthrodesis with TAA had a 3.5 times higher odds of reoperation and revision when compared to the control. Patients undergoing staged procedures did not demonstrate a difference in revision or reoperation rates when compared to the control. Staged hindfoot arthrodesis and TAA may be an effective option in treating complex end-stage ankle and hindfoot arthritis whereas a simultaneous approach may lead to higher rates of complications.