NCT05287646

Brief Summary

Individuals with lower extremity amputation are often challenged by complications that arise from poor prosthetic fit, including movement of the residual limb in the socket, known as pistoning. Pistoning can lead to gait instability, skin problems, and pain. Different prosthetic suspension systems have been developed to decrease this motion, including elevated vacuum suspension, which utilizes a pump to draw air from the socket. However, scientific analyses to understand the movement between the limb and socket have yet to be performed with a high level of accuracy. This study will use a state-of-the art imaging technique, known as dynamic stereo x-ray, to quantify the 3D movement of the residual limb in the socket. It is hypothesized that dynamic stereo x-ray will be a sensitive method to measure differences in residual limb movement between 2 different socket suspension techniques: suction and elevated vacuum suspension. This information is critical for advancing prosthetic treatments to reduce secondary conditions and degenerative changes that result from poor prosthetic fit.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
21

participants targeted

Target at below P25 for not_applicable

Timeline
11mo left

Started Jan 2024

Typical duration for not_applicable

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress72%
Jan 2024Mar 2027

First Submitted

Initial submission to the registry

March 9, 2022

Completed
9 days until next milestone

First Posted

Study publicly available on registry

March 18, 2022

Completed
1.8 years until next milestone

Study Start

First participant enrolled

January 5, 2024

Completed
3.2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

February 28, 2027

Expected
1 month until next milestone

Study Completion

Last participant's last visit for all outcomes

March 31, 2027

Last Updated

April 22, 2026

Status Verified

April 1, 2026

Enrollment Period

3.2 years

First QC Date

March 9, 2022

Last Update Submit

April 21, 2026

Conditions

Keywords

Prosthesis FittingProsthetic Suspension SystemsDynamic Stereo X-RayBiplanar FluoroscopyTranstibial AmputationPistoningElevated Vacuum SuspensionSuction SuspensionLower Extremity Amputation

Outcome Measures

Primary Outcomes (2)

  • Changes in dynamic residual tibia kinematics between suspension techniques

    To evaluate the 6 degree of freedom kinematics of the residual limb within the socket, participants with transtibial amputation will walk on a treadmill at a self-selected speed, at a speed 10% faster than their self-selected speed, and also perform a step-down task from an 18 cm high platform. These movement tasks will be completed under 2 conditions: with the elevated suspension active and with the elevated system inactive (traditional suction). Up to 4 trials of dynamic stereo x-ray will be conducted for each task for each socket condition. For each task, dynamic stereo x-ray data will be collected and analyzed to determine underlying bone movement with respect to the socket. Six degree of freedom residual tibia rotations and translations relative to the prosthetic socket will be measured.

    4 weeks post socket fit

  • Changes in dynamic skin deformation of the residual limb between suspension techniques

    Radio-opaque markers will be placed on the residual limb in specific patterns. Participants will walk on a treadmill at a self-selected speed, at a speed 10% faster than their self-selected speed, and also perform a step-down task from an 18 cm high platform. These movement tasks will be completed under 2 conditions: with the elevated suspension active and with the elevated system inactive (traditional suction). Up to 4 trials of dynamic stereo x-ray will be conducted for each task for each socket condition. For each task, dynamic stereo x-ray data will be collected and analyzed to determine underlying skin deformation. The radio-opaque markers on the skin will be tracked during the dynamic trials, and their trajectories in the socket coordinate system will define the motion of the skin relative to the socket. Shear, defined as the change in angle between the markers, and compression, defined as the change in distance between markers and a neutral position, will be calculated.

    4 weeks post socket fit

Study Arms (2)

Suction Suspension First

ACTIVE COMPARATOR

The residual limb will be imaged during dynamic activities while participants use suction suspension first, then while participants use elevated vacuum suspension. Dynamic stereo x-ray will take place 4-weeks after socket fitting.

Device: Suction Suspension First

Elevated Vacuum Suspension First

ACTIVE COMPARATOR

The residual limb will be imaged during dynamic activities while participants use elevated vacuum suspension first, then while participants use suction suspension. Dynamic stereo x-ray will take place 4-weeks after socket fitting.

Device: Elevated Vacuum Suspension First

Interventions

Participants will be fit with a socket capable of being suspended by both traditional suction and elevated vacuum. Participants will be assessed first with the elevated vacuum system inactive (traditional suction). Residual limb kinematics and skin deformation during movement tasks will be evaluated utilizing dynamic stereo x-ray. The evaluation will then be repeated with the elevated vacuum system active.

Suction Suspension First

Participants will be fit with a socket capable of being suspended by both traditional suction and elevated vacuum. Participants will be assessed first with the elevated vacuum system active. Residual limb kinematics and skin deformation during movement tasks will be evaluated utilizing dynamic stereo x-ray. The evaluation will then be repeated with the elevated vacuum system inactive.

Elevated Vacuum Suspension First

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Unilateral transtibial amputation (any etiology)
  • At least 18 years old
  • At least 6-months post-amputation
  • Current prosthetic users (at least 6 hours/day)

You may not qualify if:

  • Unable to ambulate on a treadmill at low to moderate speed
  • Inability to tolerate the socket suspensions
  • Length of the residual limb prohibits socket fitting, dynamic stereo x-ray data capture, or marker placement
  • Mental impairment that impedes study compliance
  • Skin conditions (i.e. burns or poor skin coverage) as well as those with severe contractures that prevent prior prosthetic wear
  • Severe neuropathy, uncontrolled diabetes, have insensate foot, severe phantom pain, or a significant history of skin ulcers
  • Any other significant comorbidity that would interfere with the study
  • Severe circulatory problems including peripheral vascular disease and pitting edema
  • Cognitive deficits or mental health problems that would limit ability to participate fully in the study protocol
  • Women who are pregnant or who plan to become pregnant during the study

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

VA NY Harbor Healthcare System, New York, NY

New York, New York, 10010-5011, United States

RECRUITING

Related Publications (1)

  • Paglia DN, Chomack JM, Herlihy DV, Wetterstrand C, Kadkoy Y, Duchnycz R, Kelly P, O'Connor JP, D'Andrea SE, Maikos JT. Mitigation of image distortion during mechanical testing within a dynamic stereo x-ray system. Front Bioeng Biotechnol. 2025 May 19;13:1571639. doi: 10.3389/fbioe.2025.1571639. eCollection 2025.

Study Officials

  • Jason Maikos, PhD

    VA NY Harbor Healthcare System, New York, NY

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Jason Maikos, PhD

CONTACT

Michael J Hyre, MS

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Masking Details
The statistician will be masked to the intervention order.
Purpose
BASIC SCIENCE
Intervention Model
CROSSOVER
Model Details: A randomized, block, cross-over design will be used to evaluate the residual limb-socket fit. A group of 11 (Group 1) and a group of 10 (Group 2) participants will be formed. Participants in Group 1 will first be tested with the elevated vacuum system active and then repeat all procedures with the elevated vacuum system inactive. Participants in Group 2 will first be tested with the elevated vacuum system inactive and then repeat the tasks with the elevated vacuum system active.
Sponsor Type
FED
Responsible Party
SPONSOR

Study Record Dates

First Submitted

March 9, 2022

First Posted

March 18, 2022

Study Start

January 5, 2024

Primary Completion (Estimated)

February 28, 2027

Study Completion (Estimated)

March 31, 2027

Last Updated

April 22, 2026

Record last verified: 2026-04

Data Sharing

IPD Sharing
Will share

De-identified individual participant data will be stored in a curated data repository that makes the data underlying scientific publications discoverable, freely usable, and citable, while promoting openly available research integrated with scholarly literature.

Time Frame
After study completion

Locations