Prosthetic Socket Design for Amputees

No longer recruiting at 1 trial location

Overseen By William Anderst, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Pittsburgh

Disqualifiers: Pregnancy, Osteoporosis, Radiation exposure

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

Approved in 6 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 9

Duration: 8-10 weeks

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how various modifications to prosthetic sockets affect comfort and performance for individuals with a transfemoral (above-knee) amputation. Participants will try several socket designs, each during a brief 10-minute walk, while researchers collect data. The goal is to identify the best modifications for future improvements in socket fitting for amputees. This trial suits those who use a prosthetic leg above the knee and can walk on a treadmill unaided. As an unphased trial, it offers participants the chance to directly contribute to advancements in prosthetic technology and enhance future socket designs.

Do I need to stop my current medications for the trial?

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

What prior data suggests that these prosthetic socket modifications are safe for amputees?

Research shows that different designs of above-knee prosthetic sockets affect comfort and mobility. For example, one study found that the NU-FlexSIV socket was more comfortable and satisfying than traditional designs after seven weeks. This indicates that changes in socket design can enhance user comfort.

While new technologies for prosthetic sockets are under development, existing designs remain reliable. Thus, any new changes likely build on designs that are already safe and comfortable.

In summary, although specific data on side effects for the new changes is unavailable, research and the use of similar sockets suggest these designs are generally safe and comfortable for people with amputations. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the prosthetic socket design trial because it explores how different socket modifications can improve comfort and mobility for amputees. Unlike current options, which often involve a one-size-fits-all approach, this study tests a personalized method by trying eight different socket versions in random sequences for each participant. This approach aims to find the best fit and function for individuals, potentially leading to more comfortable and effective prosthetic solutions tailored to each user's unique needs.

What evidence suggests that these prosthetic socket modifications are effective for amputees?

This trial will compare the effectiveness of different designs of above-knee prosthetic sockets. Studies have shown that changes in socket design can significantly impact their functionality for people with amputations. For example, modifications can help individuals walk more smoothly and move their hips more easily. Research indicates that certain socket designs can also enhance comfort and stability when moving. One study found that improved socket designs reduce awkward movement between the leg stump and the prosthetic, making walking more efficient. Overall, these findings suggest that better socket designs can lead to improved mobility and comfort for prosthetic leg users. ^{1 2 6 7 8}

Who Is on the Research Team?

William Anderst, PhD

Principal Investigator

University of Pittsburgh

Are You a Good Fit for This Trial?

This trial is for individuals aged 18-80 who use a transfemoral prosthesis, can walk unassisted on a treadmill, and weigh less than 125 kg. It's not suitable for those with high radiation exposure, pregnant women, or anyone clinically diagnosed with osteoporosis.

Inclusion Criteria

I use a prosthetic leg that attaches at the thigh.

I can walk by myself on a treadmill.

Body weight less than 125 kg

Exclusion Criteria

I have been exposed to high levels of radiation in the past.

I have been diagnosed with osteoporosis.

You are pregnant.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo testing with unmodified and 8 modified socket designs in a randomized order

8-10 weeks

9 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Trans-femoral prosthetic socket

Trial Overview

The study is testing specific standardized changes to the design of transfemoral prosthetic sockets. Participants will experience different socket modifications in a randomized order to prepare for future trials on individual fitting methods.

How Is the Trial Designed?

Group I: Unmodified Socket + 8 Socket Modifications in Random Order Experimental Treatment 1 Intervention

The sequence of the 9 different interventions (original socket and 8 versions derived from it) is randomized for each participant. The number of participants is smaller than the number of possible permutations. Therefore the enacted ordering is randomly selected from the pool of possible orderings. Participants walk for less than 10 minutes with every socket type while data is being collected.

Trans-femoral prosthetic socket is already approved in European Union, United States, Canada, Japan, China, Switzerland for the following indications:

Approved in European Union as Transfemoral Prosthetic Socket for:

• Transfemoral amputations

Approved in United States as Transfemoral Prosthetic Socket for:

• Transfemoral amputations

Approved in Canada as Transfemoral Prosthetic Socket for:

• Transfemoral amputations

Approved in Japan as Transfemoral Prosthetic Socket for:

• Transfemoral amputations

Approved in China as Transfemoral Prosthetic Socket for:

• Transfemoral amputations

Approved in Switzerland as Transfemoral Prosthetic Socket for:

• Transfemoral amputations

Who Is Running the Clinical Trial?

University of Pittsburgh

Lead Sponsor

Trials

1,820

Recruited

16,360,000+

United States Department of Defense

Collaborator

Trials

940

Recruited

339,000+

Published Research Related to This Trial

The transfemoral socket is essential for ensuring comfort and functionality in prosthetic limbs, regardless of the technology used in other components like knees and feet.

The article reviews different socket designs, specifically quadrilateral and ischial containment, and discusses various suspension options to optimize the fit and performance of the prosthesis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transfemoral socket design and suspension options. Kapp, SL.[2013]

In a study of 12 transfemoral amputees, those using the ischial-ramal containment (IRC) socket reported significantly better comfort and stability compared to those using the quadrilateral (QL) socket, particularly in sitting comfort and lumbar support.

Despite the IRC socket providing a more comfortable experience and better femur positioning, it did not show superior metabolic efficiency in gait compared to the QL socket, indicating that while the IRC socket may enhance comfort, it does not improve oxygen consumption during walking.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Subjective evaluations and objective measurements of the ischial-ramal containment prosthesis. Hachisuka, K., Umezu, Y., Ogata, H., et al.[2019]

A study involving 47 transfemoral prosthetic users showed that the Direct Socket interface significantly improved quality of life, comfort, and mobility compared to their previous prostheses, with 36 subjects completing the 6-month follow-up.

Participants reported enhanced stability, suspension, and overall comfort with the Direct Socket, along with improved mobility as indicated by reduced reliance on assistive devices, suggesting this method is a promising alternative to traditional prosthetic fittings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical Outcome of Transfemoral Direct Socket Interface (Part 2). Walker, J., Marable, WR., Smith, C., et al.[2023]

Both the quadrilateral and ischial containment sockets are valid options for patients with transfemoral amputations, with each design having its own advantages and applications.

Despite claims of superiority for the ischial containment socket, there is limited scientific evidence supporting its benefits over the quadrilateral socket, suggesting that both designs share more similarities than differences in their effectiveness.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Current transfemoral sockets. Schuch, CM., Pritham, CH.[2022]

The new subischial socket design improved comfort for both transfemoral prosthesis users compared to traditional ischial containment sockets, as evaluated through comfort scores.

Functional performance, measured by gait analysis and clinical outcome tests, was generally comparable between the subischial socket and ischial containment sockets, indicating that while comfort improved, overall function remained similar.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Northwestern University Flexible Subischial Vacuum Socket for persons with transfemoral amputation: Part 2 Description and Preliminary evaluation. Fatone, S., Caldwell, R.[2022]

A new system was developed to measure pressure at the stump-socket interface, revealing that maximum pressures reached 34 kPa while standing and 95 kPa during walking in two trans-femoral amputee volunteers.

The ischial containment socket provided a more evenly distributed pressure profile compared to the quadrilateral socket, which had higher pressures at the proximal brim, suggesting potential benefits for comfort and fit in prosthetic design.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stump-socket interface pressure as an aid to socket design in prostheses for trans-femoral amputees--a preliminary study. Lee, VS., Solomonidis, SE., Spence, WD.[2017]

The adjustable subischial transfemoral prosthesis was rated significantly more comfortable and functional than conventional sockets by participants, with an average comfort score of 40.9 compared to 32.8 (P=.004).

In a 2-week trial involving 18 participants, there were no adverse events such as falls or skin breakdown, and 61% of participants continued to use the adjustable prosthesis regularly after the trial, indicating its safety and effectiveness.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A Prospective Assessment of an Adjustable, Immediate Fit, Subischial Transfemoral Prosthesis. Dillingham, TR., Kenia, JL., Shofer, FS., et al.[2022]

The study developed rectification maps from 30 cast pairs of prosthetic sockets, showing that material was mainly removed from the proximal-lateral and posterior regions to improve fit for transfemoral amputees.

Using these rectification maps, a template was created that allowed for the fabrication of check sockets for 15 patients, resulting in a reasonable initial fit with only minor adjustments needed, indicating the template's effectiveness in teaching and central fabrication of the new socket design.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Quantification of rectifications for the Northwestern University Flexible Sub-Ischial Vacuum Socket. Fatone, S., Johnson, WB., Tran, L., et al.[2022]

Citations

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pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC10443468/

The Hybrid Subischial Socket for Persons With ...

This report describes the differences in terms of gait parameters, hip RoM and satisfaction with the prosthesis following the change of the socket (from ICS to ...

2.

strathprints.strath.ac.uk

strathprints.strath.ac.uk/79766/

Transfemoral prosthetic socket designs : a review of the ...

The review purpose is to assess the quality of scientific evidence and compare this for a variety of available transfemoral socket designs.

3.

sciencedirect.com

sciencedirect.com/science/article/pii/S1877065711011122

Influence of different types of sockets on the range ...

To compare the individual influence of different types of socket designs on the hip's range of motion in transfemoral amputees.

4.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC8383143/

Effects of Prosthetic Socket Design on Residual Femur ...

Individuals with transfemoral amputation experience relative motion between their residual limb and prosthetic socket, which can cause inefficient dynamic load ...

5.

cdn-links.lww.com

cdn-links.lww.com/permalink/poi/a/poi_2022_08_25_miro_poi-d-21-00198r2_sdc2.pdf

Critical Transfemoral Socket Design Features and Variations

The effect of the transfemoral prosthetic socket interface designs on skeletal motion and socket comfort: A randomized clinical trial.

6.

nupoc.northwestern.edu

nupoc.northwestern.edu/docs/inmotion_2018mar_38-43_optimized.pdf

The Newest Technology

New prosthetic socket interface technology offers the potential of improving your use of an above-knee prosthesis. To learn more about each of these ...

7.

sciencedirect.com

sciencedirect.com/science/article/abs/pii/S0003999321004615

Comparison of Ischial Containment and Subischial Sockets ...

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 ...

8.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC10443499/

Transfemoral Socket Fabrication Method Using Direct ...

Direct Socket for transfemoral (DS-TF) prosthetic user is a novel method of fabricating a laminated interface on to the residual limb but requires ...