Gait Parameters and Postoperative Pain Following Total Ankle Arthroplasty Using Wearable Motion Sensors: A Cross-Sectional Study.

Objectives Total ankle arthroplasty (TAA) is increasingly performed to alleviate pain and improve function in patients with end-stage ankle osteoarthritis. This study aimed to evaluate the gait characteristics of patients with TAA using a motion sensor-based system and to investigate the relationship between postoperative pain and gait parameters. Methods This cross-sectional study included patients at least three months post-TAA. The evaluated parameters included sex, age, postoperative period, and the dorsiflexion/plantarflexion range of motion (ROM) of the ankle. Gait analysis was performed using a six-axis inertial sensor attached to both shoes to measure stride speed, heel-strike angle, toe-off angle (TOA), pronation angle, foot progression angle, vertical height, swing width, and stride length normalized to height. Pain was assessed using the Self-Administered Foot Evaluation Questionnaire (SAFE-Q). Comparisons were made between the surgical and contralateral sides, and the correlations between pain scores and measured angles were examined. Results Thirty-eight patients (mean age: 76 ± 5 years) were evaluated. The surgical side demonstrated significantly lower TOA (48.9° vs. 59.0°) and plantarflexion ROM (35.5° vs. 49.6°) compared with the contralateral side (p < 0.001). Although the pain scores showed no correlation with ROM, TOA on the surgical side showed a positive correlation with pain scores (r = 0.379, p < 0.05). Conclusions The surgical side exhibited reduced plantarflexion ROM and smaller TOA compared with the contralateral side. Additionally, greater postoperative pain was associated with lower TOA on the surgical side. Therefore, motion sensor-based gait analysis can be a valuable tool for tailoring rehabilitation strategies and improving outcomes following TAA.