AmputationNCT05048355
Metabolic Cost of Walking With Passive vs. Powered Microprocessor Controlled Knees
A study testing Power Knee Mainstream Dynamic in people with Amputation and Prosthesis User, run by Össur Iceland ehf at 2 sites in 2 countries.
Trial summary
This study is conducted to evaluate the efficacy of the Power Knee Mainstream Dynamic compared to passive microprocessor-controlled knees (MPKs) regarding metabolic cost for high active transfemoral amputees.The test is of a single group repeated measures crossover design. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Amputation, Prosthesis User
- What is being tested?
- Power Knee Mainstream Dynamic
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 2 sitesin 2 countries
- Study dates
- 26 May 2021to 25 Aug 2021
- Phase
- Interventional
- 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
- 50Kg< body weight < 116Kg
- Cognitive ability to understand all instructions and questionnaires in the study;
- Higher active unilateral trans-femoral amputees
- Allows for 37mm knee center height to dome of pyramid alignment to allow for symmetrical knee height to sound side
- Willing and able to participate in the study and follow the protocol
- Comfortable and stable socket fit
Show all 9Show fewer
- No socket issues/changes in the last 6 weeks
- No residual limb pain affecting functional ability
- Users with at least 6 months experience on a prosthesis
Who cannot join
- Hip disarticulation amputees
- Bilateral amputees
- Users with Osseointegrated prosthesis
- Users with co-morbidities in the contra-lateral limb, which significantly affect their functional mobility
- Users taking beta-adrenergic blocking agents (beta blockers) or other medication for heart rate control e.g. Verapamil \& Digoxin.
Trial locations and contacts
2 sites in 2 countries.
2 sites in 2 countries
About this study
Official title: Metabolic Cost of Level Ground Walking With Passive vs. Powered Microprocessor Controlled Knees for Higher Active TF Amputees
This study is conducted to evaluate the efficacy of the Power Knee Mainstream Dynamic compared to passive microprocessor-controlled knees (MPKs) regarding metabolic cost for high active transfemoral amputees.The test is of a single group repeated measures crossover design. The primary endpoint is the difference in MET/HRI-VO2 index between conditions. Subjects are measured on their prescribed device at visit 1, be fitted to the PKM which they wear as their primary prosthesis for one week before coming for visit 2 and being measured again on the PKM.
Read the detailed description
The metabolic cost of ambulation for individuals living with a lower limb amputation is significantly increased compared to able-bodied individuals. Individuals living with transfemoral amputation have shown up to 65% more exertion to generate half the ambulation speed of able-bodied individuals.
The Power Knee Mainstream - Dynamic, was designed to provide powered swing dynamics to restore muscle activity and thereby attempting to mitigate this increase in metabolic cost that individuals living with TF amputation face. This study aims to evaluate this indirectly by measuring the heart rate during level ground walking on the Power Knee Mainstream - Dynamic compared to a passive MPK.
Previous studies reported in the literature on previous versions of the Power Knee have shown that it provides active flexion and extension during walking2, 3, 4 and more symmetric gait5 compared to passive microprocessor-controlled knees (MPKs). By providing increased symmetry and active swing during level ground walking the knee is meant to lower the effort needed by the transfemoral prosthesis user to swing the leg forward and thereby lower the metabolic cost of level ground walking.
This underpins the hypothesis being tested in this investigation, that the Power Knee Mainstream - Dynamic enables the user to walk with less metabolic cost compared to passive MPKs.
A pilot investigation that was conducted with 5 subjects indicated that the Power Knee Mainstream - Dynamic enabled users to walk on level ground with less metabolic cost compared to passive MPKs, however the difference did not reach statistical significance. The same study procedure will be used in this study with sufficient sample size to achieve the statistical power needed, which was determined in a power analysis using data form the pilot study mentioned above.
The primary objective of this study is to evaluate the efficacy of the investigational device compared to passive microprocessor-controlled knees (MPKs) regarding metabolic cost for high active transfemoral amputees.
The test is of a single group repeated measures crossover design. Amputees are a small proportion of the general population. The primary endpoint is the difference in MET/HRI-VO2 index between conditions.
Testing takes place in Össur HQ in Iceland as well as in Össur facility in Germany, the collective sample size in both sites is 20 subjects.
Subjects are measured on their prescribed device at visit 1, be fitted to the PKM which they wear as their primary prosthesis for one week before coming for visit 2 and being measured again on the PKM.
If a subject in the study is a current PKM user the procedure will apply in reverse and they will be provided with a Rheo knee to act as a comparator.
Prior to the first visit subjects will be contacted via telephone and asked screening questions, if they fit the inclusion criteria they will be booked for study visit 1. They will receive instructions to consume no alcohol and perform no exercise for 24 hours before study visit 1, the same applies to visit 2. In addition, they will be instructed to consume no caffeine prior to the visits (same day) or drink the same amount before both visits and keep the same routine the 24 hours prior to visit 1 and 2 (breakfast, water/drink consumption etc.).
During the one week follow up, subjects will be called via telephone to check the status of the device and the alignment and if there are issues identified they will be asked to come in to correct those
- Conditions
- Amputation, Prosthesis User
- Being tested
- Power Knee Mainstream Dynamic, Passive microprocessor controlled knee
- Keywords
- Metabolic cost, Powered prosthetics, Microprocessor controlled knees, MPKs
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Power Knee Mainstream DynamicDevice
Powered Microprocessor controlled prosthetic knee. The Power Knee Mainstream - Dynamic, was designed to provide powered swing dynamics to restore muscle activity and thereby attempting to mitigate this increase in metabolic cost that individuals living with TF amputation face.
Passive microprocessor controlled kneeDevice
Any passive microprocessor controlled prosthetic knee on the market
| Study group | Role | What they receive |
|---|---|---|
| Power Knee Mainstream Dynamic | Experimental | Users are measured using their prescribed microprocessor knee and after wearing the Power Knee Mainstream dynamic for the adaptation period, they are measured again. Receives: Device: Power Knee Mainstream Dynamic; Device: Passive microprocessor controlled knee |
What is being measured
The primary outcome is the main question the study is designed to answer.
Metabolic cost
MET/HRI-VO2 index
Measured: 1 week
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Sep 2021
- Study start26 May 2021
- Primary completion25 Aug 2021
- Study completion25 Aug 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AmputationStudies 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
- Not applicable
- Intervention model
- Single group
- Model description
- single group repeated measures crossover design
- Masking
- None (open label)
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- Össur Iceland ehf
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05048355
- Sponsor's protocol ID
- CII2021050747
- Status last verified
- Sep 2021
- First submitted
- 3 Sep 2021
- Last updated
- 8 Oct 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Oct 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Metabolic Cost of Level Ground Walking With Passive vs. Powered Microprocessor Controlled Knees for Higher Active TF Amputees
- ClinicalTrials.gov ID
- NCT05048355
- Acronym / sponsor ID
- CII2021050747
- Conditions
- Amputation, Prosthesis User
- Keywords
- Metabolic cost, Powered prosthetics, Microprocessor controlled knees, MPKs
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- Össur Iceland ehfIndustry (pharma, biotech, devices)
- Study start
- 26 May 2021 (actual)
- Primary completion
- 25 Aug 2021 (actual)
- Study completion
- 25 Aug 2021 (actual)
- First posted
- 17 Sep 2021 (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.
This study is conducted to evaluate the efficacy of the Power Knee Mainstream Dynamic compared to passive microprocessor-controlled knees (MPKs) regarding metabolic cost for high active transfemoral amputees.The test is of a single group repeated measures crossover design. The primary endpoint is the difference in MET/HRI-VO2 index between conditions. Subjects are measured on their prescribed device at visit 1, be fitted to the PKM which they wear as their primary prosthesis for one week before coming for visit 2 and being measured again on the PKM.
Detailed description
The metabolic cost of ambulation for individuals living with a lower limb amputation is significantly increased compared to able-bodied individuals. Individuals living with transfemoral amputation have shown up to 65% more exertion to generate half the ambulation speed of able-bodied individuals.
The Power Knee Mainstream - Dynamic, was designed to provide powered swing dynamics to restore muscle activity and thereby attempting to mitigate this increase in metabolic cost that individuals living with TF amputation face. This study aims to evaluate this indirectly by measuring the heart rate during level ground walking on the Power Knee Mainstream - Dynamic compared to a passive MPK.
Previous studies reported in the literature on previous versions of the Power Knee have shown that it provides active flexion and extension during walking2, 3, 4 and more symmetric gait5 compared to passive microprocessor-controlled knees (MPKs). By providing increased symmetry and active swing during level ground walking the knee is meant to lower the effort needed by the transfemoral prosthesis user to swing the leg forward and thereby lower the metabolic cost of level ground walking.
This underpins the hypothesis being tested in this investigation, that the Power Knee Mainstream - Dynamic enables the user to walk with less metabolic cost compared to passive MPKs.
A pilot investigation that was conducted with 5 subjects indicated that the Power Knee Mainstream - Dynamic enabled users to walk on level ground with less metabolic cost compared to passive MPKs, however the difference did not reach statistical significance. The same study procedure will be used in this study with sufficient sample size to achieve the statistical power needed, which was determined in a power analysis using data form the pilot study mentioned above.
The primary objective of this study is to evaluate the efficacy of the investigational device compared to passive microprocessor-controlled knees (MPKs) regarding metabolic cost for high active transfemoral amputees.
The test is of a single group repeated measures crossover design. Amputees are a small proportion of the general population. The primary endpoint is the difference in MET/HRI-VO2 index between conditions.
Testing takes place in Össur HQ in Iceland as well as in Össur facility in Germany, the collective sample size in both sites is 20 subjects.
Subjects are measured on their prescribed device at visit 1, be fitted to the PKM which they wear as their primary prosthesis for one week before coming for visit 2 and being measured again on the PKM.
If a subject in the study is a current PKM user the procedure will apply in reverse and they will be provided with a Rheo knee to act as a comparator.
Prior to the first visit subjects will be contacted via telephone and asked screening questions, if they fit the inclusion criteria they will be booked for study visit 1. They will receive instructions to consume no alcohol and perform no exercise for 24 hours before study visit 1, the same applies to visit 2. In addition, they will be instructed to consume no caffeine prior to the visits (same day) or drink the same amount before both visits and keep the same routine the 24 hours prior to visit 1 and 2 (breakfast, water/drink consumption etc.).
During the one week follow up, subjects will be called via telephone to check the status of the device and the alignment and if there are issues identified they will be asked to come in to correct those
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- single group repeated measures crossover design
| Arm | Type | Receives |
|---|---|---|
| Power Knee Mainstream Dynamic | Experimental | Device: Power Knee Mainstream Dynamic, Device: Passive microprocessor controlled kneeUsers are measured using their prescribed microprocessor knee and after wearing the Power Knee Mainstream dynamic for the adaptation period, they are measured again. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- 50Kg< body weight < 116Kg
- Cognitive ability to understand all instructions and questionnaires in the study;
- Higher active unilateral trans-femoral amputees
- Allows for 37mm knee center height to dome of pyramid alignment to allow for symmetrical knee height to sound side
- Willing and able to participate in the study and follow the protocol
Key exclusion criteria (5 listed)
- Hip disarticulation amputees
- Bilateral amputees
- Users with Osseointegrated prosthesis
- Users with co-morbidities in the contra-lateral limb, which significantly affect their functional mobility
- Users taking beta-adrenergic blocking agents (beta blockers) or other medication for heart rate control e.g. Verapamil \& Digoxin.
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 |
|---|---|---|
| Power Knee Mainstream DynamicPowered Microprocessor controlled prosthetic knee. The Power Knee Mainstream - Dynamic, was designed to provide powered swing dynamics to restore muscle activity and thereby attempting to mitigate this increase in metabolic cost that individuals living with TF amputation face. | Device | Power Knee Mainstream Dynamic |
| Passive microprocessor controlled kneeAny passive microprocessor controlled prosthetic knee on the market | Device | Power Knee Mainstream Dynamic |
Primary outcome
Metabolic cost
Time frame: 1 week
MET/HRI-VO2 index
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 8 Oct 2024.
- 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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Power Knee Mainstream Dynamic in people with Amputation and Prosthesis User, run by Össur Iceland ehf at 2 sites in 2 countries.
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 9 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 8 Oct 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Germany, Iceland. 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?
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?
Metabolic cost (time frame: 1 week). 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 8 Oct 2024.