Development of Adaptive Vacuum Suspension to Improve Prosthetic Fit and Residual Limb Health (DoD)

The purpose of the study is to evaluate residual limb circulation and skin health associated with the use of a prosthetic vacuum socket. A conventional non-vacuum prosthetic socket will be compared to a vacuum prosthetic socket.

The prosthetic suspension plays a pivotal role in an amputee's comfort. It can also significantly impact an amputee's limb health. If the prosthesis is not held securely to the amputee's limb, relative movement between the limb and prosthetic interface can cause bruising, skin irritation and skin breakdown. These poor outcomes are uncomfortable and can lead to much more serious health conditions. A positive solution to creating secure and comfortable suspension is the use of a vacuum suspension socket. The vacuum pressure assists in preventing movement in the socket. The clinical benefits associated with vacuum suspension include volume retention, increased proprioception, secure suspension, and frequently reported observations of wound healing. However, the long term effects of vacuum suspension on circulation remain undetermined or undocumented. This study examines a vacuum suspension system on the health of the residual limb (amputated limb). A vacuum socket creates a vacuum between the rigid prosthetic socket and prosthetic liner which is sealed to the socket. Therefore, vacuum is not directly applied to the skin of the residual limb.

Study Overview

• Status: Completed
• Conditions: Lower Limb Amputation
• Intervention / Treatment: Device: Active vacuum test prosthesis

Detailed Description

There are a total of 3 study visits, (some visits may be broken into separate visits per preference of subject), including socket fitting visits (which could be 2 separate visits), a baseline visit, and a final visit. During the socket visit, which may consist of a three visits plus socket adjustments (as needed by the participant) on separate days (up to 4 weeks), limb shape capture, measurement or tracing, diagnostic static fitting and diagnostic static fitting, and delivery of a definitive "research" socket will be done. At the baseline visit, participants will perform seated tasks, standing tasks, and treadmill walking tasks. Residual limb health measurements will be taken before and after the activity period, including surface electrical capacitance, Transepidermal Water Loss (TEWL) measurement, hyperspectral imaging, Hitachi Aloka ultrasound imaging, Blood Flow, and digital imaging during the baseline visit as well. The final visit, using the research socket, will consist of the same tasks and measurements as the baseline visit and questionnaires will be completed. The subject may choose to break up the final visit tasks into 2 different visits if desired.

After completion of the study, participants will be given the choice to keep the research socket or return to using their original prosthesis as normal. The study prosthetist will be available to review and adjust the fit of their standard of care prosthesis at this time. Note: Due to physical change and limb volume fluctuation over the study period, it is possible that at the end of the study the standard of care prosthesis will not fit your residual limb as it does at the beginning of the study. At the completion of the study, it is recommended that the subject follow up with their primary care prosthetist for socket evaluation and fitting.

There may be risks that are not known about at this time. Side effects, risks, and discomforts may result from study participation .While the goal of this project is to create a more comfortable prosthesis, it is possible that the subject could experience discomforts commonly associated with prosthesis use, such as perspiration, dry skin, rash, itching, blisters, high pressure in the socket, looseness in the socket, and mechanical rubbing that leads to ulceration which may lead to infection and additional surgery. Subjects with low levels of arterial blood flow have an additional risk of ulceration.

• Prosthesis placement: While the goal of this project is to create a more comfortable prosthesis, it is possible that the subject could experience discomforts commonly associated with prosthesis use, such as perspiration, dry skin, rash, itching, blisters, high pressure in the socket, looseness in the socket, and mechanical rubbing that leads to ulceration.
• Treadmill task:There is a risk of falling during the research activities. This risk is mitigated by the ability of participants to self-select pace for the treadmill task and observation of treadmill activities by research staff.
• Transcutaneous Oxygen Measurement (TcOM) and skin temperature: The PeriFlux System 5000 uses non-invasive probes that will measure the skin temperature and transcutaneous Oxygen Measurement and poses minimal risk to the subject. The probe head is affixed to the residual limb by an adhesive sticker. Removal of the sticker after data acquisition may cause minor discomfort similar to removing a small band-aid.
• Hyperspectral Imaging: This non-invasive imaging technique poses minimal risk to the subject. A small fiduciary marker sticker is placed on the subject's limb to calibrate camera settings. Removal of the sticker after imaging may cause minor discomfort similar to removing a small band-aid.
• Hitachi Aloka Ultrasound:Ultrasound imaging is a noninvasive technique and is a minimal risk procedure.
• TEWL and Surface Electrical Capacitance Measurements: TEWL and Surface Electrical Capacitance measurements are noninvasive and propose less than minimal risk.

Subjects will be queried on self-reported measures of user comfort and performance. Briefly, four subjective measures will be completed: VR-36, PEQ, SCS, and measures from the NIH PROMIS

The CHAMP test will be used to assess overall amputee performance and the effect of the socket suspension intervention over time. The conglomeration of clinical assessment tools into the CHAMP was specifically done to measure high-level mobility in service members with a lower limb amputation. CHAMP consists of the Single Leg Stance Test (SLS), the Edgren Side Step Test (ESST), Illinois Agility Test (IAT), and T Test.

IU Neuroscience Gait lab will be used to collect kinematic data. The laboratory is equipped with an instrumented treadmill and infrared camera system. A harness system will be used to provide support and safety for the amputees while study participants walk on the treadmill for 6 minutes.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Indiana
    • Indianapolis, Indiana, United States, 46202
      • IU Health Methodist Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Ages of 18 and above
• Unilateral transtibial or transfemoral amputee
• Ambulate at a K2 level or higher
• At least 3 months post-amputation per physician discretion
• Residual limb length greater than 6.5 inches in length
• Able to follow directions and give informed consent on their own or through Legally Authorized Representative.
• Must be able to ambulate without assistance. An external assistance device such as cane or walker will be permitted.
• Adequate arterial blood flow as evidenced by a TcOM >30mmHg measured within the past 12 months.

Exclusion Criteria:

• Conditions that prevent wearing a prosthetic socket,such as existing scab, ulcer, or keloid scar on amputation stump.
• Cognitive deficits or mental health problems that would limit ability to consent and participate fully in the study protocol
• Women who are pregnant or who plan to become pregnant in the near future

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Adaptive Vacuum test Prosthesis; The experimental socket system uses an active vacuum pump to push air out of the socket. The level of vacuum is controlled by hardware that automatically detects the socket fit based on in-socket motion and adjusts vacuum as needed to eliminate this motion.

Device: Active vacuum test prosthesis; The adaptive vacuum prosthesis is sold as a commercial device by the company Willow Wood with suggested U.S. L-Code L5781. The device is designated as a Class 1 Medical Device and 510(K) Exempt. This category is part of a low or moderate risk to patient safety and health. The Prosthetic socket system uses an active vacuum pump to push air out of the socket. The level of vacuum is controlled by hardware that automatically detects the socket fit based on in-socket motion and adjusts vacuum as needed to eliminate this motion.; Other Names: Limb logic system

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ratio of Trans-epidermal Water Loss (TEWL) at 16 Weeks After Use	Trans-epidermal Water Loss in 16 wks. Higher TEWL value represents a worse outcome with loss of skin barrier function. The value reported is the ratio of the TEWL of residual limb over TEWL value of the sound side limb.	Baseline and 16 Weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Hyperspectral Imaging at 16 Wks	Change from baseline in Hyperspectral Imaging at 16 wks; tissue oxygenation measured using hyperspectral imaging. Higher the HbO2 better is the perfusion in skin indicating less damage.	Baseline to16 weeks
Ultrasound Measurements at 16 Wks	In elasto-mode the blue color represents less elastic skin and weak tensile strength. whereas red is more elastic skin and high tensile strength. The blue & red color intensities in elasto mode were calculated in Matlab as arbitrary units (AU). The data presented is median of the AU. A lower AU meaning better tensile strength of the tissue meaning favorable outcome.	16 weeks

Collaborators and Investigators

• Sponsor: Indiana University
• Collaborators: United States Department of Defense
• Investigators: Principal Investigator: Chandan Sen, PhD, Indiana University

Publications and helpful links

General Publications

• Epstein RA, Heinemann AW, McFarland LV. Quality of life for veterans and servicemembers with major traumatic limb loss from Vietnam and OIF/OEF conflicts. J Rehabil Res Dev. 2010;47(4):373-85. doi: 10.1682/jrrd.2009.03.0023.
• Schultz AE, Baade SP, Kuiken TA. Expert opinions on success factors for upper-limb prostheses. J Rehabil Res Dev. 2007;44(4):483-9. doi: 10.1682/jrrd.2006.08.0087.
• Zachariah SG, Saxena R, Fergason JR, Sanders JE. Shape and volume change in the transtibial residuum over the short term: preliminary investigation of six subjects. J Rehabil Res Dev. 2004 Sep;41(5):683-94. doi: 10.1682/jrrd.2003.10.0153.
• Fernie GR, Holliday PJ. Volume fluctuations in the residual limbs of lower limb amputees. Arch Phys Med Rehabil. 1982 Apr;63(4):162-5.
• Sanders JE, Fatone S. Residual limb volume change: systematic review of measurement and management. J Rehabil Res Dev. 2011;48(8):949-86. doi: 10.1682/jrrd.2010.09.0189.
• Krueger CA, Wenke JC, Ficke JR. Ten years at war: comprehensive analysis of amputation trends. J Trauma Acute Care Surg. 2012 Dec;73(6 Suppl 5):S438-44. doi: 10.1097/TA.0b013e318275469c.
• Ramasamy A, Hill AM, Phillip R, Gibb I, Bull AM, Clasper JC. The modern "deck-slap" injury--calcaneal blast fractures from vehicle explosions. J Trauma. 2011 Dec;71(6):1694-8. doi: 10.1097/TA.0b013e318227a999.
• Bui KM, Raugi GJ, Nguyen VQ, Reiber GE. Skin problems in individuals with lower-limb loss: literature review and proposed classification system. J Rehabil Res Dev. 2009;46(9):1085-90. doi: 10.1682/jrrd.2009.04.0052.
• Harris AM, Althausen PL, Kellam J, Bosse MJ, Castillo R; Lower Extremity Assessment Project (LEAP) Study Group. Complications following limb-threatening lower extremity trauma. J Orthop Trauma. 2009 Jan;23(1):1-6. doi: 10.1097/BOT.0b013e31818e43dd.

Study record dates

Study Major Dates

• Study Start (Actual): February 12, 2020
• Primary Completion (Actual): August 25, 2021
• Study Completion (Actual): September 6, 2021

Study Registration Dates

• First Submitted: April 23, 2019
• First Submitted That Met QC Criteria: April 23, 2019
• First Posted (Actual): April 25, 2019

Study Record Updates

• Last Update Posted (Actual): May 24, 2024
• Last Update Submitted That Met QC Criteria: May 23, 2024
• Last Verified: May 1, 2024

More Information

Terms related to this study

• Keywords: Prosthesis; Transfemoral Amputees; Transtibial Amputees
• Other Study ID Numbers: 1809327674; W81XWH-16-2-0059 (Other Grant/Funding Number: DoD)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No