Changes in Pain, Function, and Gait Mechanics Two Years following Total Ankle Arthroplasty Performed with Two Modern Fixed-Bearing Prostheses

Abstract

Background: Total ankle replacement (TAR) continues to grow as an alternative to arthrodesis for patients who suffer from end-stage ankle arthritis. The purpose of this study was to examine changes in gait mechanics from before surgery to 1 and 2 years after surgery in patients who received a fixed-bearing TAR. Methods: Fifty-one patients with a primary fixed-bearing TAR and no complications requiring further surgery were identified from a database and enrolled in this non-randomized study. Subjects were examined preoperatively, and at 1 and 2 years postoperatively. Three-dimensional joint mechanics and ground reaction forces (GRF) were collected during level walking. The Four Square Step Test, Timed Up and Go (TUG), VAS, and the AOFAS-Hindfoot score were assessed for each subject at each time point. Results: TUG, VAS and AOFAS-Hindfoot score along with all measured kinetic parameters demonstrated significant improvements across all of the time points ( p < 0.05). Four Square Step Test time was significantly improved between the preoperative and 2-year postoperative time point ( p < 0.05). Measured ankle dorsiflexion angles did not demonstrate significant change between any time points. Conclusions: All of the observed changes suggest improved or maintained functioning in patients who received a TAR with the greatest improvement occurring within the first year. Sagittal plane ankle range of motion and dorsiflexion angle at heel strike were unchanged across all of the time points. The results of this study indicate that patients with end-stage osteoarthritis demonstrate improvements in pain and gait up to 2 years following surgery while maintaining ankle range of motion. Level of Evidence: IV, Prospective study