Complication Rates and Functional Outcomes after Total Ankle Arthroplasty in Patients with Rheumatoid Arthritis

Abstract

Category: Ankle Arthritis; Other Introduction/Purpose: Utilization rates of total ankle arthroplasty (TAA) have greatly increased in recent years. For patients with rheumatoid arthritis (RA) undergoing TAA, conflicting data have been reported regarding risk of complications and patient reported outcome (PRO) improvement when compared to patients with osteoarthritis. The purpose of this study is to compare complication rates and PROs of patients with RA to patients with osteoarthritis and posttraumatic arthritis. Methods: This was a retrospective study of 1,071 primary TAA performed at a single institution between 2001 and 2020. Minimum follow-up was two years. Patients were stratified by indication for TAA (osteoarthritis, n=372; posttraumatic arthritis, n=642; RA, n=57). Patient demographics, intraoperative variables, postoperative complications, and PRO measures were compared between groups using univariable statistics. Multivariable Cox regression was performed to assess risk for implant failure. Mean follow-up was 5.6 years (SD: 3.1). Results: Compared to the osteoarthritis and posttraumatic arthritis groups, the RA cohort had the lowest mean age (p < 0.001), lowest percentage of males (p < 0.001), and highest ASA score (p < 0.001). Univariate analysis showed no statistically significant difference for infection rates among groups (p=1.0). The RA cohort had the highest rate of heterotopic ossification postoperatively (2/57, 3.5%, p< 0.001). Multivariable regression analysis showed no increased risk of implant failure for the RA cohort (p=0.23). For the SMFA, SF-36, AOFAS-hindfoot, FAOS-symptoms, and FAOS-ADL the RA group reported the worst scores at final follow-up (p < 0.001). However, the RA cohort demonstrated the largest improvements from preoperative to postoperative scores on the FADI, SF-36, and the symptoms and ADL subscales of the FAOS (p=0.04, 0.01, 0.03, 0.03). Conclusion: In the largest single institution study to date, patients with RA had the worst PRO scores compared to the osteoarthritis and posttraumatic arthritis groups. However, they experienced significantly higher improvements in functional outcomes from their preoperative baseline. Large patient samples with mid- to long-term follow up such as a presented in this series are imperative to fully understand the risk-benefit of TAA in various patient cohorts.