Functional Performance Evaluation of NU-FlexSIV Socket

Study Overview
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Brief Summary
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The overall objective of this study is to provide a more comfortable and functional prosthetic socket for persons with transfemoral amputation that will ultimately improve their quality of life.

Detailed Description
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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 (computer-generated) utilizing blocks of random size 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). While a washout period is not strictly necessary, it is effectively included as subjects will need to transition back to their usual, pre-study socket/prosthesis while the second test socket is fabricated. Allocation of intervention will be concealed from the investigators until after a subject is enrolled. The starting socket design will be enclosed in sequentially numbered, opaque, sealed envelopes. Envelopes will be opened sequentially and only after the participant's name and other details are written on the appropriate envelope. Blinding of prosthetic interventions is challenging given that they are devices that must be custom-fabricated and donned each day by the subject. Hence, for this study only the assessor will be blinded. The blinded assessor will be responsible for administration of the clinical performance and patient-reported measures as well as processing of motion analysis data.

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

Conditions
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Amputation, Artificial Limbs

Intervention / Treatment
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* Device: Northwestern University Flexible Sub-Ischial Vacuum Socket
* Device: Ischial Containment Socket


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: unilateral transfemoral amputation have used a prosthesis for two or more years have a residual limb that is stable in volume and free from wounds be physically fit enough to participate in the performance tests (Medicare Functional Classification Level K3 or K4) have no previous experience of the sub-ischial socket able to complete all visits for the duration of the protocol Exclusion Criteria: have a residual limb femur of less than 5-inches co-morbidities that affect function, including neurologic abnormalities (e.g. neuropathic pain that would interfere with the study) do not speak and read English

Ages Eligible for Study
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Minimum Age: 21 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: NU-FlexSIV Socket<br>The Northwestern University Flexible Sub-Ischial Vacuum Socket is a novel socket design for transfemoral amputees. | Device: Northwestern University Flexible Sub-Ischial Vacuum Socket<br>* NU-FlexSIV sockets have lower proximal trim lines, do not impinge on the pelvis, are highly flexible so as to allow better comfort during sitting and when muscles move within the socket during activity, and are held securely to the residual limb by suction from a vacuum pump and from compression exerted by the deliberately undersized liner and socket.<br>* Other names: NU-FlexSIV Socket;Device: Ischial Containment Socket<br>* Ischial Containment (IC) sockets are more rigid and have a narrower medio-lateral dimension than anterior-posterior dimension. The socket encapsulates the ischium, ischial ramus and greater trochanter, limiting hip range of motion and comfort.<br>* Other names: IC Socket;|
| Active Comparator: IC Socket<br>The Ischial Containment Socket is the standard of care socket design for transfemoral amputees. | Device: Northwestern University Flexible Sub-Ischial Vacuum Socket<br>* NU-FlexSIV sockets have lower proximal trim lines, do not impinge on the pelvis, are highly flexible so as to allow better comfort during sitting and when muscles move within the socket during activity, and are held securely to the residual limb by suction from a vacuum pump and from compression exerted by the deliberately undersized liner and socket.<br>* Other names: NU-FlexSIV Socket;Device: Ischial Containment Socket<br>* Ischial Containment (IC) sockets are more rigid and have a narrower medio-lateral dimension than anterior-posterior dimension. The socket encapsulates the ischium, ischial ramus and greater trochanter, limiting hip range of motion and comfort.<br>* Other names: IC Socket;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Socket Comfort Score (SCS) Between IC Socket and NU-FlexSIV Sockets at 7 Weeks. | Socket comfort was assessed after each socket was worn for 7 weeks. SCS is an ordinal scale where the subject responds to the question, On a 0 to 10 scale, if 0 represents the most uncomfortable socket fit you can imagine, and 10 represents the most comfortable socket fit, how would you score the comfort of the socket of your artificial limb at the moment? | 7 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Walking Speed Between the IC Socket and NU-FlexSIV Socket at 7 Weeks. | Walking speed was assessed after each socket was worn for 7 weeks. Participants walked along a 12 meter, level walkway at their normal self-selected speed. Marker based motion capture was used to assess walking speed (m/s). | 7 weeks | 
| Step Length Between the IC Socket and NU-FlexSIV Socket at 7 Weeks. | Step length was assessed after each socket was worn for 7 weeks. Participants walked along a 12 meter, level walkway at their normal self-selected speed. Marker based motion capture was used to assess step length (cm). | 7 weeks | 
| Hip Extension Between the IC Socket and NU-FlexSIV Socket at 7 Weeks. | Hip extension was assessed after each socket was worn for 7 weeks. Participants walked along a 12 meter, level walkway at their normal self-selected speed. Marker based motion capture was used to assess hip extension (degrees). | 7 weeks | 
| Hip Range of Motion Between the IC Socket and NU-FlexSIV Socket 7 Weeks. | Hip range of motion was assessed after each socket was worn for 7 weeks. Participants walked along a 12 meter, level walkway at their normal self-selected speed. Marker based motion capture was used to assess hip range of motion (degrees). | 7 weeks | 
| Trunk Motion Between the IC Socket and NU-FlexSIV Socket at 7 Weeks. | Trunk motion was assessed after each socket was worn for 7 weeks. Participants walked along a 12 meter, level walkway at their normal self-selected speed. Marker based motion capture was used to assess trunk motion (degrees). | 7 weeks | 
| Orthotics and Prosthetics Users' Survey (OPUS) Lower-Extremity Functional Status Measure Between the IC Socket and NU-FlexSIV Socket at 7 Weeks | Lower-Extremity Functional Status was assessed after each socket was worn for 7 weeks. The OPUS Lower-Extremity Functional Status measure is a self-report instrument that assesses functional status in persons who use orthoses and prostheses. It is comprised of 20 items rated on a 5-point rating scale. Responses to items are summed to produce a total score for the measure (0 to 80) with higher scores representing better functional status. | 7 weeks | 
| Orthotics andProsthetics Users' Survey (OPUS) Health Related Quality of Life Index Between the IC Socket and NU-FlexSIV Socket at 7 Weeks. | Health Related Quality of life was assessed after each socket was worn for 7 weeks. The OPUS Health Related Quality of Life measure is self-report instrument comprised of 23 items that are evaluated with a 5-point rating scale. Responses to items are summed to produce a total score for the index (0 to 92) with higher scores representing better quality of life. | 7 weeks | 
| Orthotics and Prosthetics Users' Survey (OPUS) Satisfaction With Device Between the IC Socket and NU-FlexSIV Socket at 7 Weeks. | Satisfaction with Device was assessed after each socket was worn for 7 weeks. The OPUS Satisfaction with Device measure is a set of 11 items rated on a 5-point rating scale. Responses to items are summed to produce a total score. 9 items were used in this study for a possible score of 9 to 45 with higher scores representing better satisfaction. | 7 weeks | 
| 5-Times Rapid Sit-to-Stand Test (RSTS) Between the IC Socket and NU-FlexSIV Socket at 7 Weeks. | The 5-Times Rapid-Sit-to-Stand Test was assessed after each socket was worn for 7 weeks. Participants were asked to rise from a chair of standard height five times as fast as possible with their arms folded across their chests. Performance was timed. | 7 weeks | 
| Four-Square-Step Test (FSST) Between the IC Socket and NU-FlexSIV Socket at 7 Weeks. | The Four-Square-Step Test was assessed after each socket was worn for 7 weeks. Four sticks were placed flat on the floor in a cross that denoted a square. Participants were asked to complete a stepping sequence as fast as possible. Performance was timed. | 7 weeks | 
| T-Test of Agility (T-Test) Between the IC Socket and NU-FlexSIV Socket at 7 Weeks. | The T-Test was assessed after each socket was worn for 7 weeks. Four markers were set out so a T could be traced among them. The subject was asked to move as fast as possible between the markers, moving forwards, sideways and backwards. Performance was timed and reported in seconds. | 7 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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prosthesis, prosthetic socket, transfemoral amputation, socket comfort, gait biomechanics