Joint ContracturesNCT07454356
Knee Flexionater to Avoid Motion Restoring Surgery
A study testing Hydraulic high Intensity Stretch Device and Standard Physical Therapy in people with Joint Contractures and Total Knee Anthroplasty, run by Ermi LLC at 1 site in United States.
Trial summary
The goal of this clinical trial is to learn whether adding a stretching device to standard physical therapy can help people regain knee bending after total knee replacement surgery. Some people have difficulty bending their knee during recovery. Read more about this study
- Who is it for?
- Ages 40 years and older
- Conditions the study is for
- Joint Contractures, Total Knee Anthroplasty, Knee Arthrofibrosis
- What is being tested?
- Hydraulic high Intensity Stretch Device and Standard Physical Therapy
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 150 participants
- Where
- 1 siteUnited States
- Study dates
- 9 Dec 2025to Dec 2029
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 40 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 40 years or older
- Undergoing primary total knee replacement surgery
- Knee flexion less than 105 degrees at approximately 4 weeks after surgery
- Considered a candidate for motion-restoring surgery, with any surgery delayed until after 2 months of nonoperative treatment
Who cannot join
- Not willing to participate
- Diagnosis of advanced rheumatoid arthritis
- Neurological deficit affecting the operative leg
- Revision total knee replacement or previous major surgery on the same knee
- Cognitive impairment
- Prior total hip replacement on the same side (ipsilateral total hip arthroplasty)
- Living more than 2 hours from the study site or unwilling to attend required local physical therapy visits
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
INOV8 Orthopedics
Houston, Texas, 77043
Director of Research, 832-240-5974, bpeace@inov8hc.com
About this study
Official title: Comparing High Intensity Stretch Device Combined With Physical Therapy Versus Physical Therapy Alone to Prevent Motion-Restoring Surgery Following Primary Total Knee Arthroplasty: Study Protocol for a Randomized Controlled Trial
The goal of this clinical trial is to learn whether adding a stretching device to standard physical therapy can help people regain knee bending after total knee replacement surgery.
Some people have difficulty bending their knee during recovery. When this happens, doctors may recommend another procedure called motion-restoring surgery to improve knee movement.
Read more
This study aims to answer two main questions. First, does adding a hydraulic high-intensity stretching device to physical therapy help people regain knee bending after surgery? Second, does using the device affect recovery, daily activities, or the chance of needing another procedure?
Researchers will compare two treatment approaches. One group will receive standard physical therapy alone. The other group will receive standard physical therapy and will also use a hydraulic high-intensity stretching device called the Ermi Knee Flexionater at home.
Participants who receive the device will use it at home each day in addition to attending their physical therapy sessions. Researchers will measure how well participants can bend their knee and will ask questions about pain, daily function, and activity level. Participants will also complete simple walking and mobility tests.
Study visits will occur about four weeks after surgery when participants enroll, and again at about eight weeks, twelve weeks, six months, one year, and two years after surgery. Researchers will compare results between the two groups to see whether the stretching device improves recovery after knee replacement.
- Being tested
- Hydraulic high Intensity Stretch Device, Standard Physical Therapy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hydraulic high Intensity Stretch DeviceDevice
A hydraulic high-intensity mechanical stretch device (Ermi Knee Flexionater) used as an adjunct to standard postoperative physical therapy following primary total knee arthroplasty. The device is designed to apply controlled, patient-actuated stretch to increase knee flexion range of motion. Participants assigned to this intervention will use the device at home daily for approximately one hour, in addition to attending prescribed physical therapy sessions. Device use will begin at approximately four weeks postoperatively and continue for up to eight weeks, consistent with the study protocol. Participants will receive in-person instruction on device setup and operation and will record frequency and duration of use in a log. Compliance will be monitored through weekly check-ins.
Standard Physical TherapyOther
Supervised postoperative physical therapy following primary total knee arthroplasty. Therapy includes range of motion exercises, strengthening, neuromuscular re-education, manual therapy, and functional rehabilitation as determined by the treating clinician.
| Study group | Role | What they receive |
|---|---|---|
| Physical Therapy Only | Active comparator | Participants will receive standard postoperative physical therapy following primary total knee arthroplasty according to the treating clinician's usual rehabilitation protocol. Receives: Other: Standard Physical Therapy |
| Hydraulic high-Intensity Stretch Device Plus Standard Physical Therapy | Experimental | Participants will receive standard postoperative physical therapy and will use a hydraulic high-intensity stretch device (Ermi Knee Flexionater) at home in accordance with the study protocol. Receives: Device: Hydraulic high Intensity Stretch Device |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from Enrollment in Active and Passive Knee Flexion Range of Motion (Degrees)
Change in active and passive knee flexion measured in degrees using a standard goniometer. Higher values indicate greater knee flexion and improved range of motion.
Measured: Baseline (Enrollment at 4 weeks post-operative), 8 weeks post-operative, 12 weeks post-operative, 6 months post-operative, 1 year post-operative, and 2 years post-operative
Secondary outcomes (6)
Change from Enrollment in KOOS Score
Change in Knee injury and Osteoarthritis Outcome Score (KOOS). Scores range from 0 to 100, where 0 represents extreme knee problems and 100 represents no knee problems. Higher scores indicate better knee function.
Measured: Baseline (Enrollment), 8 weeks, 12 weeks, 6 months, 1 year, and 2 years post-operative
Change from Enrollment in WOMAC Score
Change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Total scores range from 0 to 96, where higher scores indicate worse pain, stiffness, and functional limitation.
Measured: Baseline (Enrollment), 8 weeks, 12 weeks, 6 months, 1 year, and 2 years post-operative
Change from Enrollment in Visual Analog Scale (VAS) Pain Score
Change in self-reported pain measured using a 0-10 scale, where 0 indicates no pain and 10 indicates the worst possible pain. Lower scores indicate less pain.
Measured: Baseline (Enrollment), 8 weeks, 12 weeks, 6 months, 1 year, and 2 years post-operative
Change from Enrollment in Timed Up and Go (TUG) Test Time (Seconds)
Change in time required to complete the Timed Up and Go test. Lower times (seconds) indicate improved mobility.
Measured: Baseline (Enrollment), 8 weeks, 12 weeks, 6 months, 1 year, and 2 years post-operative
Change from Enrollment in Six-Minute Walk Test (6MWT) Distance (Meters)
Change in distance walked during the Six-Minute Walk Test measured in meters. Greater distance indicates improved functional endurance.
Measured: Baseline (Enrollment), 8 weeks, 12 weeks, 6 months, 1 year, and 2 years post-operative
Number of Participants Experiencing Adverse Events
Number of participants experiencing any adverse event, including but not motion restoring surgery, limited to infection, pulmonary embolism, rehospitalization, revision surgery, or other complications following enrollment.
Measured: From enrollment to 2 years post-operative follow-up
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Mar 2026
- Study start9 Dec 2025
- Primary completionDec 2029 (estimated)
- Study completionDec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Joint ContracturesStudies 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
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ermi LLC
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Shaun K Stinton, PhD, Study director, Ermi LLC
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07454356
- Sponsor's protocol ID
- RCT-EF-225
- Status last verified
- Mar 2026
- First submitted
- 2 Mar 2026
- Last updated
- 6 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparing High Intensity Stretch Device Combined With Physical Therapy Versus Physical Therapy Alone to Prevent Motion-Restoring Surgery Following Primary Total Knee Arthroplasty: Study Protocol for a Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07454356
- Acronym / sponsor ID
- RCT-EF-225
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- Ermi LLCIndustry (pharma, biotech, devices)
- Study start
- 9 Dec 2025 (actual)
- Primary completion
- Dec 2029 (estimated)
- Study completion
- Dec 2029 (estimated)
- First posted
- 6 Mar 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.
The goal of this clinical trial is to learn whether adding a stretching device to standard physical therapy can help people regain knee bending after total knee replacement surgery.
Some people have difficulty bending their knee during recovery. When this happens, doctors may recommend another procedure called motion-restoring surgery to improve knee movement.
This study aims to answer two main questions. First, does adding a hydraulic high-intensity stretching device to physical therapy help people regain knee bending after surgery? Second, does using the device affect recovery, daily activities, or the chance of needing another procedure?
Researchers will compare two treatment approaches. One group will receive standard physical therapy alone. The other group will receive standard physical therapy and will also use a hydraulic high-intensity stretching device called the Ermi Knee Flexionater at home.
Participants who receive the device will use it at home each day in addition to attending their physical therapy sessions. Researchers will measure how well participants can bend their knee and will ask questions about pain, daily function, and activity level. Participants will also complete simple walking and mobility tests.
Study visits will occur about four weeks after surgery when participants enroll, and again at about eight weeks, twelve weeks, six months, one year, and two years after surgery. Researchers will compare results between the two groups to see whether the stretching device improves recovery after knee replacement.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Physical Therapy Only | Active comparator | Other: Standard Physical TherapyParticipants will receive standard postoperative physical therapy following primary total knee arthroplasty according to the treating clinician's usual rehabilitation protocol. |
| Hydraulic high-Intensity Stretch Device Plus Standard Physical Therapy | Experimental | Device: Hydraulic high Intensity Stretch DeviceParticipants will receive standard postoperative physical therapy and will use a hydraulic high-intensity stretch device (Ermi Knee Flexionater) at home in accordance with the study protocol. |
Who may qualify
- Ages
- 40 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age 40 years or older
- Undergoing primary total knee replacement surgery
- Knee flexion less than 105 degrees at approximately 4 weeks after surgery
- Considered a candidate for motion-restoring surgery, with any surgery delayed until after 2 months of nonoperative treatment
Key exclusion criteria (7 listed)
- Not willing to participate
- Diagnosis of advanced rheumatoid arthritis
- Neurological deficit affecting the operative leg
- Revision total knee replacement or previous major surgery on the same knee
- Cognitive impairment
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 |
|---|---|---|
| Hydraulic high Intensity Stretch DeviceA hydraulic high-intensity mechanical stretch device (Ermi Knee Flexionater) used as an adjunct to standard postoperative physical therapy following primary total knee arthroplasty. The device is designed to apply controlled, patient-actuated stretch to increase knee flexion range of motion. Participants assigned to this intervention will use the device at home daily for approximately one hour, in addition to attending prescribed physical therapy sessions. Device use will begin at approximately four weeks postoperatively and continue for up to eight weeks, consistent with the study protocol. Participants will receive in-person instruction on device setup and operation and will record frequency and duration of use in a log. Compliance will be monitored through weekly check-ins. | Device | Hydraulic high-Intensity Stretch Device Plus Standard Physical Therapy |
| Standard Physical TherapySupervised postoperative physical therapy following primary total knee arthroplasty. Therapy includes range of motion exercises, strengthening, neuromuscular re-education, manual therapy, and functional rehabilitation as determined by the treating clinician. | Other | Physical Therapy Only |
Primary outcome
Change from Enrollment in Active and Passive Knee Flexion Range of Motion (Degrees)
Time frame: Baseline (Enrollment at 4 weeks post-operative), 8 weeks post-operative, 12 weeks post-operative, 6 months post-operative, 1 year post-operative, and 2 years post-operative
Change in active and passive knee flexion measured in degrees using a standard goniometer. Higher values indicate greater knee flexion and improved range of motion.
6 secondary outcomes
Change from Enrollment in KOOS Score
Time frame: Baseline (Enrollment), 8 weeks, 12 weeks, 6 months, 1 year, and 2 years post-operative
Change from Enrollment in WOMAC Score
Time frame: Baseline (Enrollment), 8 weeks, 12 weeks, 6 months, 1 year, and 2 years post-operative
Change from Enrollment in Visual Analog Scale (VAS) Pain Score
Time frame: Baseline (Enrollment), 8 weeks, 12 weeks, 6 months, 1 year, and 2 years post-operative
Change from Enrollment in Timed Up and Go (TUG) Test Time (Seconds)
Time frame: Baseline (Enrollment), 8 weeks, 12 weeks, 6 months, 1 year, and 2 years post-operative
Change from Enrollment in Six-Minute Walk Test (6MWT) Distance (Meters)
Time frame: Baseline (Enrollment), 8 weeks, 12 weeks, 6 months, 1 year, and 2 years post-operative
Number of Participants Experiencing Adverse Events
Time frame: From enrollment to 2 years post-operative follow-up
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Mar 2026.
- Individual participant dataSharing planned: No
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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.
Shaun K Stinton, PhD study director
Ermi LLC
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Hydraulic high Intensity Stretch Device and Standard Physical Therapy in people with Joint Contractures and Total Knee Anthroplasty, run by Ermi LLC 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 7 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: looking for participants now, as of the sponsor's last update on 6 Mar 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.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from Enrollment in Active and Passive Knee Flexion Range of Motion (Degrees) (time frame: Baseline (Enrollment at 4 weeks post-operative), 8 weeks post-operative, 12 weeks post-operative, 6 months post-operative, 1 year post-operative, and 2 years post-operative). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 6 Mar 2026.