Gait variability changes before and after total hip arthroplasty are unclear. This study aimed to investigate gait variability changes in hip osteoarthritis patients before and after total hip arthroplasty and to examine the relationships between gait variability changes and hip function.
Twenty-three female patients with hip osteoarthritis (61.0 ± 7.1 yrs) and 10 healthy female participants (57.8 ± 3.9 yrs) were assessed 1 mo before and 12 mos after surgery. Heel and lower trunk accelerations were measured using two triaxial accelerometers. The coefficient of variation of stride time for gait variability of lower limb motions and the harmonic ratio for trunk variability were calculated. Radiographic leg-length discrepancy, hip abductor strength, hip abduction, extension range of motion, and pain level during gait were measured.
The coefficient of variation was significantly decreased after total hip arthroplasty and was comparable with that in healthy individuals. Although postoperative harmonic ratios were greater than preoperative harmonic ratios, they were not comparable with those in healthy individuals. The coefficient of variation changes were associated with pain relief during gait. Harmonic ratio changes were associated with hip abductor strength, extension range of motion, and limb lengthening.
Gait variability improved after total hip arthroplasty due to improved hip function. However, trunk variability was insufficient compared with that in healthy individuals.