Abstract / Summary
Abstract Recovery of gait after total hip arthroplasty (THA) has been extensively investigated in unilateral cases; however, the longitudinal recovery process following simultaneous bilateral THA remains unclear. This study aimed to longitudinally evaluate spatiotemporal gait parameters and trunk trajectory for 12 months after simultaneous bilateral THA using wearable inertial measurement unit (IMU) sensors and to compare outcomes at 12 months with healthy controls (HCs). Twenty-six patients were assessed preoperatively and at 3, 6, and 12 months postoperatively. Twenty-six age-matched healthy women served as controls. Stride length, maximum foot clearance, stride speed, stride duration, stance and swing duration, and lateral sway of the trunk, lateral sway asymmetry, vertical trunk displacement, and vertical displacement asymmetry were analyzed. Stride length and stride speed improved progressively up to 12 months. In contrast, stride duration and stance duration improved by 6 months and showed no further significant changes thereafter, with no differences compared with HCs at 12 months. Lateral trunk displacement did not demonstrate significant longitudinal improvement. At 12 months, patients exhibited slower stride speed and greater lateral trunk displacement than HCs. Age was negatively associated with postoperative stride speed, whereas body mass index was positively associated with lateral sway of the trunk. Temporal and spatial aspects of gait recovery appear to follow distinct recovery trajectories after bilateral THA. Regular monitoring using wearable IMU sensors may help identify patients with persistent gait deviations and support individualized rehabilitation strategies.