Northwestern University Feinberg School of Medicine

Northwestern University Prosthetics-Orthotics Center

Functional Performance Evaluation of the Northwestern University Flexible Sub-Ischial Vacuum (NU-FlexSIV) Socket for Persons with Transfemoral Amputation

Principal Investigator: Stefania Fatone, PhD, BPO(Hons)

Co-Investigators: Ryan Caldwell, CP**; Thomas Schnitzer, PhD

Collaborators:  Michael Oros, CPO; John Angelico, CPO (Scheck & Siress); Steve Gard, PhD; Marc Applebaum, MD; Rebecca Stine, MS (Jesse Brown VA Medical Center)

Research Assistants/Graduate Students: Lilly Tran, MS

Consultants: R. J. Garrick, PhD, Kwang-Youn Kim, PhD

**Visiting Scholar, Northwestern University and Prosthetist, Scheck & Siress

Funded by: Department of Defense #W81XWH-15-1-0708

Status: In Progress 

Introduction

We propose a Clinical Trial to compare the new prosthetic socket we developed with an FY09 PRORP Technology Development Award (Proposal #OR090122, Award #W81XWH-10-1-0744) titled, “Development of Sub-Ischial Prosthetic Sockets with Vacuum-Assisted Suspension for Highly Active Persons with Transfemoral Amputations” with the current standard of care socket with the goal of demonstrating objective functional superiority as well as more desirable patient-reported outcome measures. The availability of a more comfortable and functional socket will contribute to improving the quality of life of persons with transfemoral amputation, especially military persons with amputation who are typically young, with excellent premorbid health, and who wish to return to premorbid activity levels, resulting in higher functional expectations.

Study Design

The proposed clinical trial will be an assessor-blinded prospective randomized cross-over trial wherein participants with unilateral transfemoral amputation will be randomized to using one of two socket conditions (i.e., sub-ischial or ischial containment) before crossing over to the other socket condition. Random allocation will be used to assign the initial treatment condition.

The trial will be balanced such that all subjects will receive all treatments (i.e., both socket conditions) and that all subjects will participate for the same number of periods (i.e., two).

The primary aims of the study are:

Aim 1: To demonstrate if the NU-FlexSIV Socket is more comfortable than the IC socket.

Figure 1 Comparison of proximal trim lines between an ischial containment socket (a) and NU-FlexSIV Socket (b), hip range of motion with NU-FlexSIV Socket shown in (c-e), and flexibility of NU-FlexSIV socket shown in (f) with embedded rigid frame outlined by white tape.
Figure 1 Comparison of proximal trim lines between an ischial containment socket (a) and NU-FlexSIV Socket (b), hip range of motion with NU-FlexSIV Socket shown in (c-e), and flexibility of NU-FlexSIV socket shown in (f) with embedded rigid frame outlined by white tape.

Aim 2: To demonstrate if the NU-FlexSIV Socket results in better functional performance than the IC socket.

Aim 3: To demonstrate the NU-FlexSIV Socket will result in better quality of life and “satisfaction with device” (i.e. prosthesis) than the IC socket.

Presentations

Fatone S, Caldwell R (2016) Socket-Related Research Collaborations at Northwestern University. Scheck Fair. April 8-9, Lombard, Illinois.

Publications

Functional Performance Evaluation of the Northwestern University Flexible Sub-Ischial Vacuum (NU-FlexSIV) Socket for Persons with Transfemoral Amputation 

This study is conducted as a Randomized Crossover Trial (RCT) and is registered with clinicaltrials.gov.

Access the NU-FlexSIV Socket RCT Protocol.

Spotlight on Co-investigator John Angelico, CP, FAAOP

Read a feature article about John Angelico, his prosthetics expertise and professional contributions. Mr. Angelico is fabricating IC sockets for the Functional Performance Evaluation of the NU-FlexSIV Socket study.