Release/Relock Socket for Below Knee Amputation

Overseen By Joan E Sanders, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Washington

Disqualifiers: Skin breakdown, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

100 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new technology designed to help individuals with below-knee amputations manage changes in limb size throughout the day. Participants will use a special socket, the Release/Relock Socket, which can be adjusted for improved comfort and fit. The trial compares this new socket to traditional ones, both in a lab setting and in everyday life. It seeks individuals who have had a trans-tibial amputation for over 18 months, use a prosthesis regularly, and can walk with it for at least two minutes at a time. As an unphased trial, this study offers participants the chance to contribute to innovative research that could enhance daily comfort and mobility for many.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that this technology is safe for managing residual limb fluid volume fluctuation?

Research has shown that the Release/Relock Socket has undergone successful lab testing. In one study, 16 individuals with below-the-knee amputations used the socket in a controlled setting, and all completed the test without issues. Another study found that this socket helps maintain stable fluid levels in the limb, which is important for comfort and fit. These results suggest the socket is well-tolerated. No major problems were reported in these tests, indicating it appears to be a safe option for those considering this new technology. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the Release/Relock Socket because it introduces a novel mechanism for below-knee amputees that could improve comfort and adaptability. Unlike traditional prosthetic sockets that require fixed adjustments, this innovative socket allows users to easily release and relock the fit, accommodating changes in limb volume throughout the day. This feature is tested both in lab settings and real-world environments to assess its impact on user convenience and comfort. By potentially reducing discomfort and enhancing user experience, this new approach could represent a significant advancement over current prosthetic options.

What evidence suggests that the Release/Relock Socket is effective for managing residual limb fluid volume fluctuation?

Research has shown that the Release/Relock Socket system could enhance comfort and mobility for individuals with lower-limb amputations. This system automatically adjusts the socket size to maintain a proper fit as the limb changes size throughout the day. In this trial, participants will be assigned to different arms to test the system in various settings. One study found that taking short breaks with this system helps stabilize the limb's fluid levels, which is crucial for comfort and function. Another study noted that users experienced increased daily comfort due to the easy locking and unlocking feature. These findings suggest that the Release/Relock Socket could effectively manage limb size changes and improve the daily experience for prosthetic users. ^{5 6 7 8 9}

Who Is on the Research Team?

Joan E Sanders, PhD

Principal Investigator

University of Washington

Are You a Good Fit for This Trial?

This trial is for individuals who have had a below-knee amputation at least 18 months ago, can walk continuously for at least 90 seconds, and regularly use a definitive prosthesis with a pin-lock system. Their residual limb should be at least 9 cm long. People using walking aids, those with elevated vacuum sockets or open wounds on their residual limb cannot participate.

Inclusion Criteria

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.

K2 or higher MFCL

I had a below-the-knee amputation over 18 months ago.

Exclusion Criteria

Unable to satisfy inclusion criteria

I currently have open sores on my skin.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

In-Lab Testing

Participants operate the test socket in lab following a structured protocol to evaluate the release and relock mechanisms on limb volume.

1-2 weeks

Multiple visits (in-person)

Out-of-Lab Testing

Participants operate the test socket out of lab with no structured protocol to assess comfort and effectiveness of the release and relock mechanisms.

At least 2 days

Continuous monitoring (remote)

Follow-up

Participants are monitored for safety and effectiveness after testing, including assessments of socket comfort and limb volume changes.

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Release/Relock Socket & Control
• Release/Relock Socket - In Lab
• Release/Relock Socket - Out of Lab

Trial Overview The study is testing a new socket technology designed to adjust to daily changes in limb volume. Participants will try the Release/Relock Socket both in lab settings and during regular activities outside the lab compared to their usual control socket.

How Is the Trial Designed?

Group I: Release/Relock Socket - Out of Lab Experimental Treatment 1 Intervention

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.

Group II: Release/Relock Socket - In Lab Experimental Treatment 1 Intervention

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.

Group III: Release/Relock Socket & Control Experimental Treatment 2 Interventions

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.

Release/Relock Socket & Control is already approved in United States for the following indications:

Approved in United States as Release/Relock Socket for:

• Management of daily residual limb fluid volume fluctuation in transtibial amputation

Who Is Running the Clinical Trial?

University of Washington

Lead Sponsor

Trials

1,858

Recruited

2,023,000+

Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

Collaborator

Trials

2,103

Recruited

2,760,000+

Published Research Related to This Trial

In a study of 181 patients who underwent primary total knee arthroplasty (TKA) for valgus deformities, selective soft tissue releases were effective in achieving proper limb alignment, with an average postoperative mechanical axis of 0.13° compared to a preoperative average of 9.4°.

The study found that while more severe preoperative deformities required additional soft tissue releases, lateral retinacular release (LRR) was commonly performed (in 40% of cases) with minimal complications, indicating it is a safe option in this surgical context.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Soft Tissue Releases in Total Knee Arthroplasty for Valgus Deformities. Xie, K., Lyons, ST.[2018]

Transcutaneous osseointegration offers a promising alternative for amputees who cannot use conventional socket-based prostheses, allowing for a rigid attachment of the prosthetic limb to the residual bone, which can enhance function and patient satisfaction.

The Compress® device, originally designed for massive endoprostheses, has shown encouraging results when adapted for transcutaneous use in the U.S., and plans for a regulatory trial are underway to further evaluate its effectiveness.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Compress® transcutaneous implant for rehabilitation following limb amputation. McGough, RL., Goodman, MA., Randall, RL., et al.[2022]

In a study involving 20 unilateral transtibial amputees, the vacuum-assisted socket suspension system (VASS) resulted in significantly less residual limb pistoning compared to the pin suspension system, indicating a better fit in terms of socket stability.

However, participants were less active and preferred the pin suspension system, taking about half as many steps while using the VASS, suggesting that while VASS may improve fit, it may not enhance overall mobility or user satisfaction.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Vacuum-assisted socket suspension compared with pin suspension for lower extremity amputees: effect on fit, activity, and limb volume. Klute, GK., Berge, JS., Biggs, W., et al.[2015]

The inside-out soft-tissue release technique for correcting severe valgus knee deformities during total knee arthroplasty resulted in significant improvements in clinical scores, with the mean Knee Society clinical score rising from 30 to 93 points after surgery.

This technique demonstrated long-term effectiveness, as evidenced by a correction in mean coronal alignment from 15 degrees of valgus to 5 degrees, with no cases of delayed instability reported among the 42 knees followed for at least five years.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Total knee arthroplasty for severe valgus deformity. Five to fourteen-year follow-up. Elkus, M., Ranawat, CS., Rasquinha, VJ., et al.[2022]

The Rapidform process represents a significant advancement in the manufacturing of prostheses, allowing for complete control over the production process, which enhances the precision and customization of prosthetic devices.

Clinical and laboratory results indicate that Rapidform is not only swift and accurate but also economical, making it a practical solution for producing various types of prosthetic sockets without the need for specialized services.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Rapidform process for automated thermoplastic socket production. Davies, RM., Lawrence, RB., Routledge, PE., et al.[2017]

In a study of 359 total knee arthroplasty patients, a novel pie crust release technique for the superficial medial collateral ligament (MCL) was found to be safe and effective, achieving normal medio-lateral stability in 95% of patients who underwent this technique.

The algorithmic release approach resulted in satisfactory correction of knee alignment in 82.9% of patients, highlighting the importance of preoperative coronal alignment and other factors in determining the appropriate release technique for varus knees.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Soft tissue balancing in varus total knee arthroplasty: an algorithmic approach. Verdonk, PC., Pernin, J., Pinaroli, A., et al.[2022]

A modification to the trans-tibial shuttle lock release mechanism allowed a morbidly obese client with limited mobility to independently remove their prostheses, demonstrating the efficacy of the adjustment.

The client was satisfied with the modified release mechanism's operation, and all components functioned well at the three-month follow-up, indicating the procedure's safety and effectiveness, although cosmetic concerns and other factors must be considered for broader application.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Shuttle lock release modification of a trans-tibial prosthesis with an obese client. Highsmith, MJ., Kahle, JT., Hoover, RM.[2007]

In a study involving eight unilateral below-knee amputees, CAD-CAM prosthetic sockets required more adjustments (one change for all but one socket) compared to hand-made sockets (only two changes), indicating potential challenges in initial fit.

Despite differences in design and configuration, both CAD-CAM and hand-made sockets were similarly accepted by patients in terms of comfort, with no significant differences reported in pressure or pain levels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of CAD-CAM and hand made sockets for PTB prostheses. Köhler, P., Lindh, L., Netz, P.[2017]

The study involved five unilateral trans-tibial amputees who assessed their socket comfort and satisfaction using questionnaires, but the results showed no statistically significant differences in interface pressure between comfortable and uncomfortable socket conditions, except in specific areas.

Despite the lack of clear findings, the study suggests that larger sample sizes and longer acclimation periods are necessary to better understand the relationship between socket pressure and patient-reported comfort and satisfaction outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Socket Interface Pressure and Amputee Reported Outcomes for Comfortable and Uncomfortable Conditions of Patellar Tendon Bearing Socket: A Pilot Study. Safari, MR., Tafti, N., Aminian, G.[2015]

The selective medial release technique using pie-crusting during primary total knee arthroplasty (TKA) was found to be effective, with significant improvements in Knee Society scores and the Western Ontario and McMaster Universities Osteoarthritis Index after surgery.

Out of 729 knees reviewed, no specific complications related to the pie-crusting technique were identified, indicating that it is a safe method for addressing medial tightness in TKA.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Selective Medial Release Technique Using the Pie-Crusting Method for Medial Tightness During Primary Total Knee Arthroplasty. Ha, CW., Park, YB., Lee, CH., et al.[2018]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9087223/

Performance of an auto-adjusting prosthetic socket during ... The purpose of this study was to test the stability of a socket that automatically adjusted socket size to maintain fit.

2. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1350453321000254

An innovative mechanism to maintain residual limb volume The purpose of this research was to develop and evaluate a system to allow for quick and easy locking pin and socket panel release during sitting and relock ...

3. cdmrp.health.mil cdmrp.health.mil/prorp/research_highlights/23Joan_Sanders_highlight

2023 Peer Reviewed Orthopaedic Highlight PRORP Highlight: Improved Daily Comfort and Mobility for Lower-Limb Amputees Using Novel Release-Relock System.

4. nature.com nature.com/articles/s41598-024-61234-9

An adaptive prosthetic socket for people with transtibial ... This study presents results from take-home testing of a motor-driven adaptive socket that automatically adjusted socket size during walking.

5. clinbiomech.com clinbiomech.com/article/S0268-0033(23)00117-1/fulltext

Short partial doffs of release/relock sockets may effectively ... A partial doff duration as short as 4 min may be an effective strategy to stabilize limb fluid volume in prosthesis users with transtibial amputation.

6. apps.dtic.mil apps.dtic.mil/sti/trecms/pdf/AD1092709.pdf

A Release/Relock Socket to Enhance Volume ... - DTIC Significant results or key outcomes: The significant result was the completion of a functional release and relock system, and the completion of ...

7. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/37210769/

Short partial doffs of release/relock sockets may effectively ... Short partial doffs of release/relock sockets may effectively stabilize limb fluid volume in prosthesis users with transtibial amputation · Authors · Affiliations.

8. clinconnect.io clinconnect.io/trials/NCT04305782

NIH Release/Relock Socket (NCT04305782) - ClinConnect The goal of the research is to create and evaluate a new technology for management of daily residual limb fluid volume fluctuation.

9. researchgate.net researchgate.net/publication/380602520_An_adaptive_prosthetic_socket_for_people_with_transtibial_amputation

An adaptive prosthetic socket for people with transtibial ... This study presents results from take-home testing of a motor-driven adaptive socket that automatically adjusted socket size during walking. A ...