Effects of a Valgus Unloader Brace on Medial Femoral Cartilage

March 24, 2020 updated by: University of North Carolina, Chapel Hill

Effects of a Valgus Unloader Brace on Medial Femoral Cartilage Changes Following Walking Protocol

The purpose of this study is to determine the effect of a valgus unloader brace condition on the acute change in medial femoral condyle cartilage morphology using Ultrasound following a standardized walking protocol.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Participants will report to an initial screening session during which knee alignment will be determined using a long-lever goniometer. For the assessment of baseline knee alignment, the participant will stand with feet facing forward directly underneath corresponding acromion processes and weight evenly distributed. The first axis will be measured from ASIS to midpoint of the patella and the second axis will be measured from the midpoint of the patella to the tibial tuberosity. The valgus angle will be used to determine eligibility for the study. To be eligible for this study, participants must present with a valgus knee alignment angle of ≥180° on the dominant limb defined as the limb the participant would use to kick a ball. Weight and height measurements will also be measured and used to calculate BMI. Once eligible, participants will determine a self-selected walking speed by walking between 2 sets of infrared timing gates (TF100, TracTronix). Starting approximately 5 steps before the first timing gate, participants will be instructed to walk at a speed described as "comfortable walking over a sidewalk". Each participant will complete 3 trials and the average walking speed will be calculated.

Pre-loading Protocol

Participants will report to the laboratory at the same time of day (±2 hours) for both sessions to account for diurnal variations within the cartilage. Upon arrival, participants will sit on a treatment table in the long-sit position with knees fully extended for 45 mins to allow time for cartilage reformation.

Ultrasonographic Assessment of the Femoral Articular Cartilage While seated with their back up against the wall, participants will flex their knee to 140° measured using a manual goniometer while. A measuring tape will be secured to the length of the table so that the position of the posterior calcaneus can be recorded to allow for consistent positioning across trials 15. A LOGIQe US system (General Electric Co., Fairfield, CT) with a 12MHz linear probe will be used to image both the medial and lateral femoral cartilage. The probe will be placed transversely in line between the medial and lateral femoral condyles just superior to the patella and rotated to maximize reflection off the articular cartilage. A transparent grid will be placed over the US screen to improve reproducibility of the US image. The midpoint of the intercondylar groove will be aligned with the center of the grid.

The level of the cartilage-bone interface at the edge of the image on either side will be recorded in order to ensure consistent positioning across US assessments. Three images will be collected of each knee at each time point. Following each loading condition, the participant will be placed in the same position as the pre-loading US assessment using the tape measure. Three images of the femoral cartilage will be recorded from each knee. All post-walking images will be captured within 5 minutes of the loading protocol.

Ultrasonographic Image Analysis All US images will be analyzed with the ImageJ software (National Institutes of Health, Bethesda, MD). Values for all measurement types will be obtained for each of the three images of the dominant limb at each time point (pre and post-walking) and averaged for statistical analysis.

Cartilage Thickness

Cartilage thickness (in millimeters) will be determined at the most inferior point of the intercondylar groove, the midpoint of the medial condyle, and the midpoint of the lateral condyle by drawing a line from the cartilage-bone interface to the synovial space-cartilage interface.

Cartilage Area The femoral cartilage will be divided into medial and lateral sections by identifying the midline at the most inferior point of the intercondylar groove. Each section of the cartilage will be outlined with a polygon function (Figure 1). The area (in square millimeters) of each section will be measured.

Average Cartilage Thickness The area (in square millimeters) of each section as determined in the cartilage area measure will then be divided by the length (in millimeters) of the section measured via a segmented line along the cartilage-bone interface (Figure 2). Average cartilage thickness (in millimeters) measures will be determined for the medial and lateral condyles. Values will be obtained for each of the three images per limb at each time point (pre and post-walking) and averaged for statistical analysis.

Cartilage Loading Protocol Immediately following pre-test ultrasound assessments, participants will be transferred from the table to a wheelchair in order to minimize knee loading not related to the walking condition. During the braced walking condition, a valgus unloader brace (Össür Unloader One®, Össur Americas, Orange County, CA) will be fitted by a certified athletic trainer per manufacturer instructions to the dominant limb while the participant is seated with knee flexed to approximately 80°.

The brace will be maximally adjusted to unload the medial compartment. The participant will take 30 steps to adjust to the brace. Adjustments will then be made as needed if the participant determines the fit is uncomfortable or too loose. The participant will take 30 more steps. Any final adjustments can be made at that point. The participant will then be transferred to and from the treadmill via wheelchair to control the amount of cartilage loading.

Control Protocol In the unbraced condition, the participant will repeat the brace protocol except that the participant will not be fitted with an unloader brace while seated. The participant will take 60 steps to keep the number of steps consistent across trials before being transferred to the treadmill. The participant will remain unbraced for the entire trial.

Loading Protocol Participants will maintain the self-selected walking speed for 5000 steps on a treadmill (4Front, WOODWAY, Waukesha, WI). Self-selected speed will be kept the same across both conditions. Participant will walk for 1 minute to adjust to treadmill. Steps will then be counted for 1 minute, and the time necessary to complete 5000 steps will be calculated (5000 divided by number of steps per minute).

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

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

Study Locations

  • United States
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27599
        • University of North Carolina at Chapel Hill

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 35 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Uninjured participants. There will be no exclusion based on race, gender or ethnicity.

Exclusion Criteria:

  • congenital or degenerative joint condition, orthopedic implants, current joint pain (quantified as less than 2 on a 10cm visual analog scale),
  • cartilage injury of any joint, lower extremity fracture, or upper extremity fracture within the last year.
  • any major ligamentous or cartilage injury of the knee or hip joints, or reported of cartilage injury at the ankle.

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

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Braced
Össür Unloading Knee Brace used during walking protocol
Other: Össür Unloading Knee Brace

During the braced walking condition, a valgus unloader brace (Össür Unloader One®, Össur Americas, Orange County, CA) will be fitted by a certified athletic trainer per manufacturer instructions to the dominant limb while the participant is seated with knee flexed to approximately 80°.

The brace will be maximally adjusted to unload the medial compartment.

Other Names:
  • Össür Unloader One®
No Intervention: Unbraced
Walking protocol without the use of brace

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Pre walking - Thickness (mm) of the Medial Femoral Articular Cartilage as measured by ultrasound
Time Frame: Prior to the walking protocol
Thickness of the articular cartilage on the Medial Femoral condyle will be measured in millimeters
Prior to the walking protocol
Post walking - Thickness (mm) of the Medial Femoral Articular Cartilage as measured by ultrasound
Time Frame: Immediately following the walking protocol (the post-test will be finished within approximately 5 minutes of concluding the walking protocol)
Thickness of the articular cartilage on the Medial Femoral condyle will be measured in millimeters
Immediately following the walking protocol (the post-test will be finished within approximately 5 minutes of concluding the walking protocol)

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of North Carolina, Chapel Hill

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Joshua Valentine, University of North Carolina, Chapel Hill
  • Study Chair: Brian Pietrosimone, PhD, University of North Carolina, Chapel Hill

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2017

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 1, 2019

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 1, 2019

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 28, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 1, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 5, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 25, 2020

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 24, 2020

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2020

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 17-0831

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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.

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