NIH Release/Relock Socket

Study Overview
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Brief Summary
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The goal of the research is to create and evaluate a new technology for management of daily residual limb fluid volume fluctuation.

Detailed Description
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Limb fluid volume changes that can occur in the residual limb of a lower-limb amputee can result in changes in socket fit that lead to discomfort, skin injuries, and reduced mobility. It is known that limb fluid volume fluctuations can be reduced for some people by intermittently removing (doffing) the socket throughout the day. It is believed that partially doffing the socket may have a similar benefit, and could be made more convenient thereby promoting easier compliance for prosthetic users. The goal of the research is to create and evaluate a new technology for management of daily residual limb fluid volume fluctuation. The technology enables partial doffing through the release and relock of a socket panel and the prosthetic pin used to hold the limb in place. The expected outcomes are an enhanced understanding of how socket adjustments after activity facilitate limb fluid volume recovery, subsequent fluid retention, and improved socket fit.

Official Title
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NIH Release/Relock Socket

Conditions
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Lower Limb Amputation Below Knee (Injury)

Intervention / Treatment
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* Device: Release/Relock Socket - In Lab
* Device: Release/Relock Socket - Out of Lab
* Device: Release/Relock Socket & Control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Had trans-tibial amputation at least 18 months prior to enrollment Regularly wear a definitive prosthesis for at least 7 hours per week Have a residual limb length of at least 9 cm K2 or higher MFCL Able to walk continuously with a prosthesis for at least 2 minutes at a time Sit, stand, and negotiate a step of 5.0 cm Participants involved remotely will have to meet the following inclusion criteria: Have a spare prosthesis No cognitive issues Good hand dexterity and strength (not frail) Capable of communication over a video Zoom conference call. Exclusion Criteria: Current presence of skin breakdown Unable to satisfy inclusion criteria

Ages Eligible for Study
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Minimum Age: 18 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: Supportive Care
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Release/Relock Socket - In Lab<br>The test socket will be operated by the participant in lab, following a structured protocol. This arm focuses on the order effects on the re-lock panel and pin mechanisms on limb volume. | Device: Release/Relock Socket - In Lab<br>* The participants will operate the test socket in one of two test conditions: (1) pin re-lock before panel re-lock and (2) panel re-lock before pin re-lock. Participants will test each of the two conditions in a random order, in lab, following a structured protocol. Tests will determine if the order of the re-lock mechanisms influences changes in limb volume.<br>|
| Experimental: Release/Relock Socket - Out of Lab<br>The test socket will be operated by the participant out of lab, with no structured protocol. This arm focuses on the effects of the re-lock panel and pin mechanisms on participant comfort. | Device: Release/Relock Socket - Out of Lab<br>* The participants will operate the test socket in one of two test conditions: (1) pin re-lock before panel re-lock and (2) panel re-lock before pin re-lock. Participants will test each of the two conditions in a random order, out of lab, with no structured protocol. Tests will determine if the order of the re-lock mechanisms changes participant experience.<br>|
| Experimental: Release/Relock Socket & Control<br>The test socket will be operated by the participant out of lab, with no structured protocol. This arm focuses on the comparing participant experience using the novel mechanism versus traditional socket mechanisms. | Device: Release/Relock Socket - In Lab<br>* The participants will operate the test socket in one of two test conditions: (1) pin re-lock before panel re-lock and (2) panel re-lock before pin re-lock. Participants will test each of the two conditions in a random order, in lab, following a structured protocol. Tests will determine if the order of the re-lock mechanisms influences changes in limb volume.<br>Device: Release/Relock Socket & Control<br>* The participants will operate the test socket in one of two test conditions: (1) release/relock mechanisms enabled and (2) release/relock mechanisms disabled. Participants will test each of the two conditions in a random order, out of lab, with no structured protocol. Tests will determine how the novel release/relock mechanisms compare against traditional socket release methods.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Limb Volume | Limb volume fluctuations will be measured in real-time as socket release/relock strategies are tested. This will be accomplished using a portable bioimpedance device with thin sticky electrodes that are placed on the residual limb. Specifically, the change in limb volume will be assessed from a baseline period where no socket adjustments are made to another period within the same test session where socket adjustments are made. | Change from baseline period (no release/relock) to test period (release/relock), commonly each 1 hour long and separated by a seated period of approximately 30 minutes | 
| Prosthesis Evaluation Questionnaire (PEQ) | Participants will be asked to fill out a questionnaire related to their experience using the test socket out of lab in various test configurations. Each question on the PEQ can receive a score form 0 to 100, with higher scores indicating greater satisfaction. | Administered following out of lab testing, after at least 2 days using the test socket in out-of-lab environments. | 
| PROMIS-Fatigue | Participants will be asked to fill out a questionnaire related to their experience using the test socket out of lab in various test configurations. Each PROMIS-Fatigue question asks participants to rank on a scale from 1 to 5 (categorical options), with higher scores indicating greater level of fatigue. | Administered following out of lab testing, after at least 2 days using the test socket in out-of-lab environments. | 
| Socket Comfort Score (SCS) | Participants will be asked to rank their comfort while using the test socket out of lab in various test configurations. The SCS ranges from 0 to 10 (categorical), with higher scores indicating greater level of comfort. | Administered following out of lab testing, after at least 2 days using the test socket in out-of-lab environments. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Prosthetic Socket, Amputee, Pin Lock Prosthetic Socket