Microbiome Population Adaptation Study (OLIMPAS)

August 25, 2025 updated by: Walter Reed National Military Medical Center

Osseointegrated Limb Implant Microbiome Population Adaptation Study

The investigators will accomplish our research aims by collecting cutaneous microbiome samples from 50 persons that have undergone the Osseointegration (OI) surgery at eight timepoints, prospectively. The investigators will also collect control samples to correct for turnovers in species compositions that may naturally occur and to compare the residual limb microbiome to the sound contralateral limb. The investigators will sequence the bacterial community using universal bacterial primers. Using these sequences, The investigators will borrow from ecological theory and calculate the alpha and beta diversity. The alpha diversity will determine the species and abundance of each species that are present, while the beata diversity will allow us to compare how species assemblages and frequencies change between time points. Then, the investigators will take a phylogenetic modeling approach to determine if particular species assemblages correlate with rates of wound healing. The investigators will construct phylogenies from the sequences at the different time points and "paint" the rate of wound healing along the phylogeny (e.g., improved, stagnated, worsened). Using Akaike and Bayesian information criterion, the investigators can determine which phylogenetic model best explains the patterns the investigators see across patients. Lastly, the investigators will quantify soft tissue stability and health and correlate this with the homeostasis of the microbial community. Specifically, the investigators will determine if redundant soft tissue leads to altered microbial communities that can impact the rate of wound healing. Finally, the investigators will further stratify these data to compare microbial communities between the sexes, upper versus lower limbs, and proximal versus distal amputations. This work will allow us to better treat infections after OI surgery and can shed light on wound healing process so that the investigators can better treat limb loss patients and the military community as a whole.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Patients that are undergoing to have OI surgery will be asked if they would like to participate in the research study. All the data collected for the study is research related and will be collected on the case report forms ( CRFs) /source documents and will be entered into the Henry Jackson Foundation (HJF) REDCap.

Below is a breakdown of the research-related study procedures. All of these procedures will be done for research purposes, none of them are for the standard of care. The investigators will coincide study visit with clinical visits/ follow ups. The investigators will collect the following information from the patients/clinician:

Baseline/Pre-operative Surgery Stage I

Demographics (DOB, sex, height, weight, BMI, length of residual limb, amputated side, side indicated for surgery, date of amputation, reason for amputation, details of reason for amputation, issues with prior/current prosthesis) Medication: The investigators will collect detailed information about the medications (names, indication, dose, frequency, route. etc.) that the patients are currently taking (including over-the counter medications, vitamins, or herbal treatment).

Hygiene Questionnaire Biome sample (Osseointegrated and control site) Flora Data Collection Sample Questionnaire Flora Data Collection Sample Questionnaire-Control Holger Score System Questionnaire ( It is a score that the investigators is given after they evaluate the participant's skin condition).

Clinical Assessment

Pre-operative Surgery Stage II, Post-Operative 3 Weeks, 3 Months, 6 Months, and 12 Months Follow-Ups from Surgery Stage II

Medication: The patients will be asked about any changes to the medications that they are taking currently.

Hygiene Questionnaire Biome sample (Osseointegrated and control site) Flora Data Collection Sample Questionnaire Flora Data Collection Sample Questionnaire-Control Holger Score System Questionnaire

Post-Operative Surgery Stage II (in the OR)

Flora Data Collection Sample Questionnaire Flora Data Collection Sample Questionnaire-Control Biome sample (Osseointegrated and control site) Holger Score System Questionnaire

24 Months Post-Operative Surgery Stage II

Medication: The patients will be asked about any changes to the medications that they are taking currently.

Hygiene Questionnaire Biome sample (Osseointegrated and control site) Flora Data Collection Sample Questionnaire Flora Data Collection Sample Questionnaire-Control Holger Score System Questionnaire Thighplasty Questionnaire Clinical Assessment

Data collected will include flora samples collections and soft tissue envelop analysis

Flora samples collections

Biome samples will be collected /swabbed by one of the study team members. The swab area of skin or abutment will be about 2 cm x 2 cm.

Samples collecting swabbing sites For unilateral amputation patients Amputated limb: Implant surface, aperture site, the midpoint between amputated site and groin or axillary crease, and amputation site Contralateral limb as a control: as same level as amputated limb (compatible location of swabbing sites to the imputed limb) For the bilateral amputation patients Both amputated limbs: Implant surface, aperture site, the midpoint between amputated site and groin or axillary crease (as control) Anytime a participant has an infection and comes in outside of research-related timepoints The investigators will collect a Biome sample (Osseointegrated and control site), Flora Data Collection Sample Questionnaire, Flora Data Collection Sample Questionnaire-Control, and clinical assessment.

Sample collection swabbing procedures

Flora is the microorganisms that exist in all living things. The investigators will use the swabbing method to collect the participant's skin biome/flora samples on their Osseointegrated and control site. The fresh swab will be in a moistening buffer such as saline or distilled water. One of the study team members will use one hand to stretch the skin site taut. With the other hand, hold the swab so the shaft is parallel to the skin surface. Apply firm pressure and rub the swab back and forth rigorously 50 times (for 30 seconds). The swab will be put in the tube buffer and will be taken to the freezer as soon as possible (within 30 min of collecting). This is a noninvasive procedure that will cause no pain but may cause discomfortable at the collecting site. If the participants ask us to stop to collection the samples because they experience any pain, The investigators will stop to collection the flora samples.

The participant's skin flora samples will be collected at Baseline/Pre-operative Surgery Stage I, Pre-operative Surgery Stage II, Immediate post-operative Surgery Stage II (in the Operation room), Post-Operative 3 Weeks, 3 Months, 6 Months, 12 Months, and 24 months Follow-Ups from Surgery Stage II.

Swab samples processing, storing, and analysis

The swab needs to go in the tube buffer and be taken to the freezer ASAP (within 30 min of collecting). These biome samples will be stored at the -20 º the Surgical Critical Care Initiative (SC2i) freezer located in building#9. Once the investigators have accumulated enough samples, the investigators will send these samples to Zymo Research Corporation for sequencing on dry ice so the samples remain frozen. After the analysis of these samples by Zymo, the results will be sent back as text and a fasta file. The text files will be the results (alpha and beta diversity, species identified, etc.) and the fasta file will be the actual genetic sequence. Zymo will dispose of all unused samples after three months once the study has been completed

The soft tissue envelope analysis

The soft tissue envelope will be measured for redundancy and scored using the Modified Holger Score System. The investigators will document soft tissue redundancy and hypermobility, drainage and irritability, and active infection. Clinical data being collected are demographics (DOB, sex, height, weight, BMI, length of residual limb, amputated side, side indicated for surgery, date of amputation, reason for amputation, details of reason for amputation, issues with prior/current prosthesis), other relevant past and present medical conditions and medications. Questionnaires that will be collected are hygiene (how many times a day do the participants clean participants' residual limb, what product(s) do the participants use to clean their residual limb, do participant apply any product(s), like lotion, after the participants have cleaned their residual limb, if yes what product(s), flora data collection sample questionnaire (date of assessment, flora sample site, flora sample control site, what site collecting from (implant surface, aperture site, contralateral limb) and person collecting sample), Holger Score System (normal skin, reddish, red and moist, granulation tissues and skin complication leading to removal of the abutment, skin overgrowth), Clinical Assessment (soft tissue-redundancy, hypermobility, drainage irritable), wound grade (improved, stagnated and worsened) and thighplasty questionnaire (did the patient have to have a thighplasty).

Study Type

Observational

Enrollment (Estimated)

50

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Male and female military health care beneficiaries aged 18-75 years old have undergone an osseointegrated percutaneous prosthetic system.

Description

Inclusion Criteria:

  • Any adult male or female that will undergo an OI procedure between the ages of 18-75.
  • Defense Enrollment Eligibility Reporting System (DEERs) eligible

Exclusion Criteria:

  • Inability to provide self-consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Study subjects
Individuals with a limb amputation who are undergoing an osseointegration surgery
Other: Collection of biologic samples and data
  • collection of skin flora samples via swabs
  • data collection regarding subject's medications See Detailed Description in Study Description section above for more details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Determine if OI surgery causes changes in the microbiome community using phylogenies
Time Frame: month 36
We will use phylogenies and phylogenetic comparative methods to quantify the changes in the cutaneous microbiome flora before and after OI surgery. This will be done by comparing phylogenies across time points to determine changes in species lineage composition.
month 36
Determine if changes in the microbiome community predicts wound healing using phylogenetic comparative methods
Time Frame: months 36-48
We will use phylogenetic comparative methods and community turnover rates, quantified via alpha and beta diversity measures, to determine if community perturbations impact wound healing.
months 36-48
Quantify soft tissue health using a modified Holger Score (0 = healthy soft issue and 6 = unhealthy soft tissue) to phylogenetically correlate this with microbiome homeostasis.
Time Frame: months 36-48
We will clinically quantify soft tissue stability using a modified Holger Score, then, we will use a phylogenetic correlation to determine if soft tissue health drives microbiome homeostasis
months 36-48

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Floral profiles
Time Frame: months 40
We will use phylogenies to build species assemblages profiles (which species are present) for each participant. Then, we will use phylogenetic methods to compare profiles within each patient through time.
months 40
Floral colonization
Time Frame: months 42
We will use the microbial profiles and phylogenies to determine the colonization order of the microbiome after OI surgery by comparing which species are present at baseline and which species are present at the subsequent follow-ups.
months 42
Clinical guidelines
Time Frame: month 48
We will design and write clinical practice guidelines to identify a skin penetration aperture infection and disseminate to the public so others can use the same guidelines
month 48
Surgical site questionnaire
Time Frame: month 44
We will develop and disseminate a questionnaire for the cleaning and maintenance of the skin penetration aperture to correlate hygiene routines and probability of developing a superficial infection.
month 44
Post-OI hygiene guidelines
Time Frame: month 46
We will develop and disseminate a skin penetration aperture hygiene guidelines based on the findings of the microbiome profiles to reduce the probability of developing a superficial infection.
month 46
Soft tissue stability guidelines
Time Frame: month 46
We will develop and disseminate best practice guidelines for clinicians based on our findings to educate surgeons on soft tissue stability and when surgical intervention is needed to correct soft tissue complications.
month 46
Holger score validation
Time Frame: Time Frame: month 48
We will validate our modified Holger Score (0 = healthy soft issue and 6 = unhealthy soft tissue) in osseointegrated patients for the skin penetration aperture by determining the interobserver variation.
Time Frame: month 48

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Walter Reed National Military Medical Center

Investigators

  • Principal Investigator: Ean R Saberski, MD, Walter Reed National Military Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 1, 2023

Primary Completion (Estimated)

November 30, 2027

Study Completion (Estimated)

November 30, 2029

Study Registration Dates

First Submitted

February 21, 2024

First Submitted That Met QC Criteria

March 6, 2024

First Posted (Actual)

March 15, 2024

Study Record Updates

Last Update Posted (Estimated)

August 26, 2025

Last Update Submitted That Met QC Criteria

August 25, 2025

Last Verified

August 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

  • WRNMMC-2023-0434
  • 67407 (Other Grant/Funding Number: PRORP)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

We will not share individual participant data (IPD) available to other researchers.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Amputation With Osseointegration

Clinical Trials on Collection of biologic samples and data

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Nigeria

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe