Effect of transfemoral prosthetic socket interface design on gait, balance, mobility, and preference: A randomized clinical trial.

Background: There are alternative transfemoral (TF) socket interface designs that have not been compared with the standard of care, ischial ramus containment (IRC). The interface directly affects performance.

Objectives: To compare 3 TF interface designs, IRC, dynamic socket (DS), and subischial (Sub-I), regarding gait, balance, mobility, and preference. The authors hypothesized that these more active users may experience gait, mobility, and preference benefits from the less intrusive DS and Sub-I interface designs.

Study Design: Single-blind, repeated-measures, 3-period randomized controlled crossover clinical trial.

Methods: People with unilateral TF amputation with 1 year or longer prosthesis use experience, independent community ambulatory status, 18 to 60 years of age, of any race or ethnicity, with a body mass of 45 to 125 kg, and with a self-reported ability to walk for 20 minutes continuously were included in the study. Each participant was fit in all 3 interface designs.

Results: Thirteen participants completed the clinical trial. Velocity, cadence, mobility, and balance were not statistically different between the 3 socket conditions. The DS demonstrated significantly greater symmetry in swing, stance, single support percentage, and toe angle compared with IRC and Sub-I. Sixty days after study completion, 7 participants changed interfaces, trending away from IRC.

Conclusions: Large differences were not observed. Small differences in spatiotemporal gait measures combined with patient preference may make a meaningful difference to individual patients and should be considered.