Knee Flexion ContractureEarly Phase 1NCT07620145
Anterior Heel Wedge to Treat Flexion Contracture After Total Knee Arthroplasty
A Early Phase 1 study testing Anterior heel wedge in people with Knee Flexion Contracture and Total Knee Arthroplasty (TKA), run by University of North Carolina, Charlotte at 1 site in United States.
Trial summary
Total knee arthroplasty (TKA) remains the only treatment for end-stage knee osteoarthritis, whereby the diseased ends of the bones comprising the knee joint are removed and replaced with prosthetic joint components. Approximately 500,000 of these procedures are performed annually in the United States. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Knee Flexion Contracture, Total Knee Arthroplasty (TKA)
- What is being tested?
- Anterior heel wedge
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 8 participants
- Where
- 1 siteUnited States
- Study dates
- 16 Mar 2023to 31 Dec 2025
- Phase
- Early Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- over the age of 18 years
- underwent primary, unilateral TKA and approved for participation by surgeon
- present with flexion contracture in the operative limb (5 degrees or greater at least 3 months after surgery)
- body mass index <40kg/m^2
Who cannot join
- underwent revision TKA
- underwent bilateral TKA
- require use of assistive device to walk
- inability to consistently comprehend and repeat back directions, including for reasons of not understanding/speaking English
- current smoker
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Efficacy of Anterior Heel Wedge at Reducing Knee Flexion Contracture After Total Knee Arthroplasty: A Pilot Investigation
Total knee arthroplasty (TKA) remains the only treatment for end-stage knee osteoarthritis, whereby the diseased ends of the bones comprising the knee joint are removed and replaced with prosthetic joint components. Approximately 500,000 of these procedures are performed annually in the United States. Despite an otherwise successful procedure and post-operative rehabilitation process, about 5% of all individuals will develop a flexion contracture after TKA. Flexion contracture limits the knee joint range of motion, which has negative impacts on activities of daily living and health-related quality of life. Standard of care treatment for resolving flexion contracture requires more surgery or, at minimum, more exposure to anesthesia to manipulate the joint and improve range of motion. The investigators have developed a non-invasive means for resolving flexion contracture, The investigators propose fixing a wedge to the sole of the patient's shoe such that the taller end of the wedge is located near the toes and the shorter end is closer to the heel. Biomechanically, this forces the individual to make ground contact during walking closer to the heel rather than the toes (which is typically observed in patients with flexion contracture). By forcing ground contact closer to the heel, patients gradually force their knee to extend (straighten) over time and resolve the flexion contracture. The aim of this pilot investigation is to test the hypothesis that the anterior wedge worn on the shoe during all walking activities for 4 weeks will reduce the severity of the flexion contracture in patients after TKA.
- Being tested
- Anterior heel wedge
- Keywords
- walking, knee, range of motion
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Anterior heel wedgeDevice
A continuously-worn shoe anterior heel wedge that fits on the under surface of the shoe just under the toe box. When worn during walking, the anterior heel wedge may help to increase knee joint range of motion and reduce knee flexion contracture in patients after total knee arthroplasty.
| Study group | Role | What they receive |
|---|---|---|
| Orthotic | Experimental | Participants enrolled in this arm wear an anterior heel wedge, in the form of a shoe orthotic, to improve walking and reduce knee flexion contracture. The wedge is worn continuously on the shoe for 1 month. Receives: Device: Anterior heel wedge |
What is being measured
The primary outcome is the main question the study is designed to answer.
Gait biomechanics
Participants will walk over level ground at a self-selected pace and one equivalent to average older adult walking speed.
Measured: From enrollment to the end of treatment at 4 weeks
Secondary outcomes (4)
Patient-reported outcomes
Participants will complete the Knee Osteoarthritis Outcomes Survey (0-100, higher scores are better).
Measured: From baseline to the end of the intervention at 4 weeks
Patient-reported outcomes
Participants will complete a Global rating of change (-7 to 7, higher scores indicate more positive changes).
Measured: From baseline to the end of the intervention at 4 weeks
Patient-reported outcomes
Participants will complete the VR-12 (0-100 with higher scores indicating more optimal physical and mental well-being) .
Measured: From baseline to the end of the intervention at 4 weeks
Patient-reported outcomes
Participants will complete the International Physical Activity Questionnaire- Short Form (0- no max possible, higher scores indicate greater levels of physical activity).
Measured: From baseline to the end of the intervention at 4 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jun 2026
- Study start16 Mar 2023
- Primary completion31 Dec 2025
- Study completion31 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Knee Flexion ContractureStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 8 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of North Carolina, Charlotte
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Abbey Thomas, PhD, University of North Carolina, Charlotte
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07620145
- Sponsor's protocol ID
- 22-1206
- Status last verified
- May 2026
- First submitted
- 19 Dec 2024
- Last updated
- 2 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Sappey-Marinier E, Fernandez A, Shatrov J, Batailler C, Servien E, Huten D, Lustig S. Management of fixed flexion contracture in primary total knee arthroplasty: recent systematic review. SICOT J. 2024;10:11. doi: 10.1051/sicotj/2024007. Epub 2024 Mar 26.
PubMed 38530205
Study at a glance
From the registry record, last updated by the sponsor on 2 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy of Anterior Heel Wedge at Reducing Knee Flexion Contracture After Total Knee Arthroplasty: A Pilot Investigation
- ClinicalTrials.gov ID
- NCT07620145
- Acronym / sponsor ID
- 22-1206
- Keywords
- walking, knee, range of motion
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 8 participants (actual)
- Lead sponsor
- University of North Carolina, CharlotteUniversity, hospital or other
- Study start
- 16 Mar 2023 (actual)
- Primary completion
- 31 Dec 2025 (actual)
- Study completion
- 31 Dec 2025 (actual)
- First posted
- 2 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Total knee arthroplasty (TKA) remains the only treatment for end-stage knee osteoarthritis, whereby the diseased ends of the bones comprising the knee joint are removed and replaced with prosthetic joint components. Approximately 500,000 of these procedures are performed annually in the United States. Despite an otherwise successful procedure and post-operative rehabilitation process, about 5% of all individuals will develop a flexion contracture after TKA. Flexion contracture limits the knee joint range of motion, which has negative impacts on activities of daily living and health-related quality of life. Standard of care treatment for resolving flexion contracture requires more surgery or, at minimum, more exposure to anesthesia to manipulate the joint and improve range of motion. The investigators have developed a non-invasive means for resolving flexion contracture, The investigators propose fixing a wedge to the sole of the patient's shoe such that the taller end of the wedge is located near the toes and the shorter end is closer to the heel. Biomechanically, this forces the individual to make ground contact during walking closer to the heel rather than the toes (which is typically observed in patients with flexion contracture). By forcing ground contact closer to the heel, patients gradually force their knee to extend (straighten) over time and resolve the flexion contracture. The aim of this pilot investigation is to test the hypothesis that the anterior wedge worn on the shoe during all walking activities for 4 weeks will reduce the severity of the flexion contracture in patients after TKA.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Orthotic | Experimental | Device: Anterior heel wedgeParticipants enrolled in this arm wear an anterior heel wedge, in the form of a shoe orthotic, to improve walking and reduce knee flexion contracture. The wedge is worn continuously on the shoe for 1 month. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- over the age of 18 years
- underwent primary, unilateral TKA and approved for participation by surgeon
- present with flexion contracture in the operative limb (5 degrees or greater at least 3 months after surgery)
- body mass index <40kg/m^2
Key exclusion criteria (5 listed)
- underwent revision TKA
- underwent bilateral TKA
- require use of assistive device to walk
- inability to consistently comprehend and repeat back directions, including for reasons of not understanding/speaking English
- current smoker
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Anterior heel wedgeA continuously-worn shoe anterior heel wedge that fits on the under surface of the shoe just under the toe box. When worn during walking, the anterior heel wedge may help to increase knee joint range of motion and reduce knee flexion contracture in patients after total knee arthroplasty. | Device | Orthotic |
Primary outcome
Gait biomechanics
Time frame: From enrollment to the end of treatment at 4 weeks
Participants will walk over level ground at a self-selected pace and one equivalent to average older adult walking speed.
4 secondary outcomes
Patient-reported outcomes
Time frame: From baseline to the end of the intervention at 4 weeks
Patient-reported outcomes
Time frame: From baseline to the end of the intervention at 4 weeks
Patient-reported outcomes
Time frame: From baseline to the end of the intervention at 4 weeks
Patient-reported outcomes
Time frame: From baseline to the end of the intervention at 4 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Jun 2026.
- Results publication: PubMed 38530205Sappey-Marinier E, Fernandez A, Shatrov J, Batailler C, Servien E, Huten D, Lustig S. Management of fixed flexion contracture in primary total knee arthroplasty: recent systematic review. SICOT J. 2024;10:11. doi: 10.1051/sicotj/2024007. Epub 2024 Mar 26.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Anterior heel wedge in people with Knee Flexion Contracture and Total Knee Arthroplasty (TKA), run by University of North Carolina, Charlotte at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 2 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Gait biomechanics (time frame: From enrollment to the end of treatment at 4 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07620145, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jun 2026.