Abstract
Objective
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.
Design
Randomized crossover trial with two 7-week periods.
Setting
Private prosthetic clinics and university research laboratory.
Participants
A total of 30 enrolled (N=30); 25 participants completed the study with full (n=18)
or partial data (n=7).
Interventions
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.
Main Outcome Measures
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.
Results
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.
Conclusions
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.
Keywords
List of abbreviations:
4SST (Four Square Step Test), IC (ischial containment), MDC (minimal detectable change), NU-FlexSIV (Northwestern University Flexible Subischial Vacuum Socket), OPUS (Orthotics and Prosthetics Users’ Survey), QOL (quality of life), STST (Sit-to-Stand Test), SCS (Socket Comfort Score), TFA (transfemoral amputation), VASS (vacuum-assisted suction suspension)To read this article in full you will need to make a payment
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Article info
Publication history
Published online: June 29, 2021
Accepted:
May 27,
2021
Received in revised form:
May 20,
2021
Received:
November 18,
2020
Footnotes
Presented to Hanger Clinic, February 4-5, 2021, virtual meeting; OT World, October 27-29, 2020, virtual meeting; Minneapolis VA Research Service, January 14, 2020, Minneapolis, MN; International Society for Prosthetics and Orthotics, October 5-8, 2019, Kobe, Hyogo, Japan; Australian Orthotic and Prosthetic Association, October 4-6, 2018, Gold Coast, Australia; Northwestern University Prosthetics-Orthotics Center, March 13, 2018, Chicago, IL; Scheck & Siress, April 27-28, 2018, Lombard, IL; American Academy of Orthotists and Prosthetists, February 14-17, 2018, New Orleans, LA; Midwest Chapter of the American Academy of Orthotists and Prosthetists, November 11, 207, Chicago, IL; Scheck and Siress, April 8-9, 2016, Lombard, IL.
Supported by the Assistant Secretary of Defense for Health Affairs, through the Peer Reviewed Orthopaedic Research Program (award no. W81XWH-15-1-0708). Opinions, interpretations, conclusions, and recommendations are those of the author and are not necessarily endorsed by the Department of Defense. Supported in part by the National Institutes of Health's National Center for Advancing Translational Sciences (grant no. UL1TR001422). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The sponsors had no role in the study design, collection, analysis, and interpretation of data, writing of the report, or the decision to submit the article for publication.
Clinical Trial Registration No.: NCT02678247.
Disclosures: Stefania Fatone and Ryan Caldwell are the codevelopers of the NU-FlexSIV Socket technique. The other authors have nothing to disclose.
Identification
Copyright
© 2021 The American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
