Predicting post‐total ankle arthroplasty walking speed based on preoperative gait mechanics

Abstract

Decreased walking speed is associated with impaired physical performance and function in older adults. Following total ankle arthroplasty (TAA), walking speed continues to be slower than age matched controls. The purpose of this study was to determine if patients 1 year post‐TAA can achieve walking speed benchmarks and investigate if gait metrics are predictive of achieved benchmarks. 191 TAA patients were recruited and assessed pre‐TAA and 1 year post‐TAA. Kinetic and kinematic data were collected during seven self‐selected speed barefoot walking trials along a 30‐m walkway. Receiver operator curves were generated for each variable to determine threshold values needed to achieve walking speeds of 0.8, 0.9, 1.1, and 1.3 m/s. Each variable's predictive ability was classified according to the area under the curve. Ninety one percent of participants achieved a walking speed > 0.8 m/s, 85.3% achieved ≥0.9 m/s, 64.9% walked at ≥1.1 m/s, and 24.1% achieved a walking speed of 1.3 m/s by 1 year post‐TAA. Walking speed pre‐TAA was the strongest predictor with ankle moment, power and GRF data showing mixed results. Clinical Significance: 75.9% of participants were unable to walk at 1.3 m/s—a speed indicative of safely crossing a street. Variables predictive of postoperative walking speed benchmarks could be useful in developing interventions for the TAA population. The strongest predictor across all walking speed benchmarks was preoperative walking speed. A walking speed > 0.71 m/s was predictive of achieving 0.8 m/s 1 year post‐TAA, while >1.09 m/s predicted 1.3 m/s 1 year post‐TAA.