Powered Knee-Ankle Prosthesis and Microprocessor Knee Prosthesis for Transfemoral Amputee

Overseen By Shenan Hoppe-Ludwig, CPO

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Shirley Ryan AbilityLab

Disqualifiers: Over 250 lbs, Inactive, Cognitive deficits, Pregnant, Others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 26

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial examines how well new powered prosthetic devices assist individuals who have lost a leg above the knee. It evaluates two types of prosthetic knees: the Microprocessor (MP) Knee Prosthesis and the Vanderbilt Powered Knee-Ankle Prosthesis, to determine if they enhance movement and comfort in daily life. The trial targets individuals who have lost one leg above the knee, use a microprocessor knee, and can walk at various speeds. The researchers aim to discover if these new prosthetics significantly impact daily activities. As an unphased trial, it offers participants the chance to contribute to innovative research that could improve mobility and quality of life for many.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It is best to discuss this with the trial coordinators or your doctor.

What prior data suggests that these prosthetic devices are safe for transfemoral amputees?

Research has shown that the Vanderbilt Powered Knee-Ankle Prosthesis (PKA) has undergone testing in several studies. In one study, three service members used the PKA with special training, and results indicated improved mobility without major safety issues.

Another study examined the PKA's effects on two individuals with above-knee amputations. They experienced no serious side effects, suggesting the device is generally well-tolerated.

The Microprocessor (MP) Knee Prosthesis is another device under research. Although specific safety details from these studies were not provided, MP knee prostheses are widely used and accepted in the medical field.

Both devices aim to enhance mobility for individuals with above-knee amputations, and current evidence suggests they are generally safe to use. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about these prosthetic treatments for transfemoral amputees because they offer advanced features that could enhance mobility and quality of life. Unlike traditional prosthetics, the Vanderbilt Powered Knee-Ankle Prosthesis includes powered assistance, which helps users move more naturally and efficiently. This means it can actively aid in walking, rather than relying solely on the user's effort. On the other hand, the Microprocessor (MP) Knee Prosthesis uses smart technology to adapt to the user's movements, providing a more personalized and responsive experience. Both devices represent a leap forward in prosthetic technology, offering potential improvements in comfort, adaptability, and ease of movement for amputees.

What evidence suggests that these prosthetic devices are effective for transfemoral amputees?

Studies have shown that powered knee-ankle prostheses, such as the Vanderbilt Powered Knee-Ankle Prosthesis tested in this trial, can ease walking for individuals with above-the-knee amputations. Research indicates that these devices help users expend less energy, reducing fatigue during walking. One study found that users of powered prosthetics walked faster and maintained better balance. Another study demonstrated that this type of prosthesis could also alleviate back pain by making movement feel more natural. These early findings suggest that powered knee-ankle prostheses might enhance daily life for those with leg amputations. Participants in this trial will also have the opportunity to train with a Microprocessor (MP) Knee Prosthesis, allowing for a comparison of the two devices. ^{1 2 3 4 6}

Who Is on the Research Team?

Arun Jayaraman, PT, PhD

Principal Investigator

Shirley Ryan AbilityLab

Are You a Good Fit for This Trial?

This trial is for individuals with one leg amputated above the knee who are currently using a microprocessor knee prosthesis and can walk at various speeds. They must be under 250 lbs, not pregnant, mentally fit to consent and follow instructions, and free of other serious health issues that could affect participation.

Inclusion Criteria

You need to use a special computerized knee on your artificial leg.

I have lost one leg at or above the knee.

I can walk with little to no assistance.

Exclusion Criteria

I weigh more than 250 lbs.

I do not have any major health issues that could affect my participation in the study.

I am physically inactive and unfit.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Prosthetic Fitting and Training

Participants undergo up to 8 prosthetic fitting sessions and up to 12 physical therapy training sessions using either the Vanderbilt Powered Knee-Ankle Prosthesis or their own Microprocessor Knee Prosthesis.

12 weeks

Up to 20 visits (in-person)

Wash-out Period

An 8-week period to allow normalization to the use of the device, reducing carryover effects.

8 weeks

Post-Training Assessment

Participants return for up to 6 post-training assessment sessions to evaluate the effects of the prosthetic devices.

2 weeks

Up to 6 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment.

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Microprocessor (MP) Knee Prosthesis
• Vanderbilt Powered Knee-Ankle Prosthesis

Trial Overview The study is testing the effectiveness of a new powered prosthetic leg called Vanderbilt Powered Knee-Ankle Prosthesis compared to standard microprocessor knees in improving mobility and social interaction for people with above-knee amputations.

How Is the Trial Designed?

Group I: Vanderbilt Powered Knee-Ankle Prosthesis Experimental Treatment 1 Intervention

Upon screening and enrollment participants return for up to 8 prosthetic fitting sessions and up to 12 physical therapy training sessions using the Vanderbilt Powered Knee-Ankle (PKA) Prosthesis. Once training is complete participants will return for up to 6 post-training assessment sessions using the Vanderbilt Powered Knee-Ankle (PKA) Prosthesis. The device participants begin with will be randomly selected but there will be an equal opportunity to train with both devices. In between training, there will be an 8 week "wash out period" to allow normalization to use of the device, reducing carryover effects. After wash-out period protocol will be repeated with second device.

Group II: Microprocessor (MP) Knee Prosthesis Active Control 1 Intervention

Upon screening and enrollment participants return for up to 8 prosthetic fitting sessions and up to 12 physical therapy training sessions using their own Microprocessor (MP) Knee Prosthesis. Once training is complete participants will return for up to 6 post-training assessment sessions using the Microprocessor (MP) Knee Prosthesis. The device participants begin with will be randomly selected but there will be an equal opportunity to train with both devices. In between training, there will be an 8 week "wash out period" to allow normalization to use of the device, reducing carryover effects. After wash-out period protocol will be repeated with second device.

Who Is Running the Clinical Trial?

Shirley Ryan AbilityLab

Lead Sponsor

Trials

212

Recruited

17,900+

Published Research Related to This Trial

In a study of 45 low-activity transfemoral amputees transitioning from mechanical knees to microprocessor knees (MPKs), significant improvements were observed in balance, walking distance (measured by the two-minute walk test), and confidence, despite no significant changes in health-related quality of life or gait profile score.

The findings suggest that while MPKs may not drastically change overall quality of life or gait metrics, they can enhance functional mobility and reduce falls, indicating potential benefits for low-activity users.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of patient-reported and functional outcomes following transition from mechanical to microprocessor knee in the low-activity user with a unilateral transfemoral amputation. Davie-Smith, F., Carse, B.[2023]

The Proprio-foot®, a quasi-active microprocessor-controlled ankle prosthesis, significantly improved balance and quality of life in 45 patients compared to standard ankle prostheses, as measured by various assessments over a 34-day period.

Despite these improvements, there was no significant difference in energy expenditure (measured by oxygen uptake) between the Proprio-foot® and standard prostheses during treadmill walking.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of a microprocessor-controlled ankle-foot unit on energy expenditure, quality of life, and postural stability in persons with transtibial amputation: An unblinded, randomized, controlled, cross-over study. Colas-Ribas, C., Martinet, N., Audat, G., et al.[2022]

Microprocessor prosthetic knees (MPKs) significantly improve functional status and quality of life for patients with lower limb amputation compared to non-microprocessor prosthetic knees (NMPKs), based on a systematic review of 18 studies involving up to 602 participants.

While MPKs show clear advantages over NMPKs, the specific benefits of more advanced models like the Genium® compared to others like the C-leg® and Rheo knee® are not well established, indicating a need for further research.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Impact of microprocessor prosthetic knee on mobility and quality of life in patients with lower limb amputation: a systematic review of the literature. Thibaut, A., Beaudart, C., Maertens DE Noordhout, B., et al.[2023]

Commercial microprocessor-controlled prosthetic knees (MPKs) are mostly passive and rely on heuristic intent classifiers, while research MPKs are powered and often use machine learning for better intention detection, indicating a significant technological gap.

The main challenges for the commercial viability of active MPKs include demonstrating their benefits over passive models, evaluating their performance in real-world settings, and ensuring that control parameters remain practical for users.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A Comparison of Control Strategies in Commercial and Research Knee Prostheses. Fluit, R., Prinsen, EC., Wang, S., et al.[2021]

Microprocessor-controlled prosthetic knees (MPKs) significantly reduce falls and fear of falling in limited community ambulators, based on a systematic review of 13 studies involving 2366 patients, with 704 classified as limited community ambulators.

MPKs also improve mobility, walking speed, and patient-reported ambulation, making them a valuable therapeutic option for individuals with transfemoral amputations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effect of microprocessor controlled exo-prosthetic knees on limited community ambulators: systematic review and meta-analysis. Hahn, A., Bueschges, S., Prager, M., et al.[2023]

The pilot study involving five elderly transfemoral amputees showed that using a microprocessor-controlled knee prosthesis (MPK) improved perceptions of safety and resulted in more natural gait patterns compared to standard non-microprocessor-controlled knee prostheses (NMPK) after just 4 to 6 weeks of familiarization.

However, the study suggests that without structured training and a longer acclimation period, the functional benefits of the MPK may not be fully realized, indicating that additional support may be necessary for optimal use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety and function of a prototype microprocessor-controlled knee prosthesis for low active transfemoral amputees switching from a mechanic knee prosthesis: a pilot study. Hasenoehrl, T., Schmalz, T., Windhager, R., et al.[2018]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC2836171/

Self-Contained Powered Knee and Ankle Prosthesis In the absence of net power generation at the knee and ankle, transfemoral amputees with passive prostheses have been shown to expend up to 60% more metabolic ...

2. frontiersin.org frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2018.00134/full

Impact of Powered Knee-Ankle Prosthesis on Low Back ... In this case series, we studied the impact of using a powered knee-ankle prostheses (PKA) on two transfemoral amputees who currently use advanced ...

3. withpower.com withpower.com/trial/phase-11-2016-3aa41

Powered Knee-Ankle Prosthesis and Microprocessor ... The overall goal of this research is to determine the efficacy of new powered prosthetic devices for individuals with transfemoral amputations.

4. academic.oup.com academic.oup.com/milmed/article/188/11-12/3432/6650769

Functional Performance Outcomes of a Powered Knee–Ankle ... Here, three service members (SM) with unilateral transfemoral limb loss received an optimally tuned PKA prosthesis and device-specific training.

5. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1350453321001442

Early evaluation of a powered transfemoral prosthesis with ... These early results suggest the efficacy of simplifying impedance control tuning and fusing control and energy regeneration in transfemoral prostheses.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC5874899/

Impact of Powered Knee-Ankle Prosthesis on Low Back ... In this case series, we studied the impact of using a powered knee-ankle prostheses (PKA) on two transfemoral amputees who currently use ...