Comparison of Ischial Containment and Subischial Sockets on Comfort, Function, Quality of Life, and Satisfaction With Device in Persons With Unilateral Transfemoral Amputation: A Randomized Crossover Trial.

Abstract

To compare comfort and functional performance of the Northwestern University Flexible Subischial Vacuum (NU-FlexSIV) Socket with the ischial containment (IC) socket in persons with unilateral transfemoral amputation. Randomized crossover trial with two 7-week periods. Private prosthetic clinics and university research laboratory. A total of 30 enrolled (N=30); 25 participants completed the study with full (n=18) or partial data (n=7). Two custom-fabricated sockets (IC and NU-FlexSIV), worn full-time for 7 weeks, with testing at 1, 4, and 7 weeks after socket delivery. The primary outcome was change in Socket Comfort Score (SCS) at 7 weeks. Secondary outcomes at 7 weeks included the Orthotic and Prosthetic Users' Survey (OPUS) to assess lower extremity functional status, health-related quality of life, and satisfaction with device, as well as the 5-Times Rapid Sit-to-Stand Test, Four Square Step Test, and T-Test of Agility to assess functional performance. At 7 weeks, the mean SCS for IC (7.0±1.7) and NU-FlexSIV (8.4±1.1) Sockets were significantly different (P<.001; 95% confidence interval, 0.8-2.3). Results from a linear mixed-effects model, accounting for data from all time points, indicated that the SCS was 1.7 (SE=0.45) points higher for the NU-FlexSIV Socket (P<.001). For the secondary outcomes, only OPUS satisfaction with device was significantly better in the NU-FlexSIV Socket after accounting for all data points. The results suggest that after 7 weeks' accommodation, the NU-FlexSIV Socket was more comfortable and led to greater satisfaction with device than the IC socket in persons with unilateral transfemoral amputation and K3/K4 mobility. Other patient-reported outcomes and function were no different between sockets.