Factors Associated with Surgical Success of End Stage Ankle Arthritis with Minimum 4-Year Follow-Up

Abstract

Category: Ankle Arthritis; Ankle Introduction/Purpose: Both total ankle arthroplasty (TAA) and ankle arthrodesis (AA) are effective treatments for ankle arthritis. This study sought to use a statistical modeling approach to determine factors associated with success following either surgery. While a number of studies have explored risk factors associated with complications, our aim was to guide management based on factors which may be predictive of success. Methods: We retrospectively analyzed data from a prospective multicenter cohort study conducted between May 2012 and May 2015. We compared outcomes in 448 patients who had follow-up of at least 4 years and were treated for ankle arthritis with either TAA or AA. We collected baseline factors including demographics, pre- and post-operative outcome scores including the Foot and Ankle Ability Measure (FAAM), Short Form-36 (SF-36) Physical and Mental Component Summary scores, pain, ankle related adverse events, and radiographs (coronal tilt and sagittal subluxation). We defined fully Successful as an increase in the FAAM ADL score by the minimum clinically important difference (MCID) and the absence of post-operative complications. We performed a multivariate logistic regression model adjusted for age, sex, BMI, and surgery type to identify associations with success. Results: Of the 517 patients who consented, had surgery and completed post-operative surveys, 414 (80.0%) underwent TAA and 103 (19.9%) underwent AA. Of the 517 patients, 448 patients (86.7%) had a minimum of 4-year follow-up. Of the 448 patients, 331 (73.9%) were successful) outcome and 117 (26.1%) were not fully successful. Out multivariable logistic model found female sex (0.83 +- 0.03, p=0.002), treatment with TAA (0.80 +- 0.020, p=0.001), and no previous surgery (0.82 +- 0.03, p=0.030) as variable significantly associated with success. Notably, mental health factors and pre-operative radiographic measurements, including coronal tilt and sagittal subluxation, were not significantly associated with success. Conclusion: Surgeons treating patients with ankle arthritis have two viable surgical alternatives. Recognizing the factors associated with mid-term success may be as valuable as knowing risk factors associated with failure. In addition, we also find variables thought to affect outcomes, mental health and pre-operative radiographic measurements such as coronal plane misalignment, were not found to significantly affect outcomes.