Altered Gait and Total Ankle Arthroplasty Influence Ankle and Hindfoot Joint Kinematics during Cadaveric Simulations of Level Walking.
Academic Article
Overview
abstract
The progression of ankle arthritis causes altered gait patterns to develop that persist even after total ankle arthroplasty (TAA) and rehabilitation, although the contributions of altered gait and implantation to this persistence are unknown. The objective of this study was to quantify changes in joint kinematics resulting from the combined and individual contributions of total ankle implantation and gait alterations during simulated level walking. Twelve cadaveric feet were tested on a six-degree-of-freedom robot to simulate level walking in four conditions: intact with healthy gait (Intact-Healthy), intact with altered gait (Intact-Altered), implanted with healthy gait (TAA-Healthy), and implanted with altered gait (TAA-Altered). Nonparametric 95% confidence intervals for paired samples were calculated for the kinematics of the ankle, subtalar, and talonavicular joints in each condition. Isolated implantation and altered gait conditions changed ankle and hindfoot joint kinematics during simulated level walking. The ankle joint was more dorsiflexed, everted, and internally rotated due to altered gait, while implantation largely corrected the rotational changes induced by it. Altered gait increased subtalar eversion, dorsiflexion, and external rotation in late stance, whereas implantation either exacerbated these changes or failed to correct them. Implantation and altered gait increased talonavicular joint abduction and eversion across different portions of the stance phase, with increased dorsiflexion in late stance due to altered gait, a change mitigated by implantation. The combination of these factors largely corrected ankle kinematics but often exacerbated kinematic changes in the hindfoot joints and should be considered in the design and evaluation of implants.
