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

15 Participants Needed

Trial Summary

What is the purpose of this trial?

The overall goal of this research is to determine the efficacy of new powered prosthetic devices for individuals with transfemoral amputations. The anticipation is that this will be a high-impact technological intervention with the potential to restore significant functionality to individuals with lower limb amputation and transform the field of lower limb prosthetics. The objective of the proposed clinical trial is to fully evaluate the biomechanical and energetic effects of using PKA prosthesis and quantify functional performance and quality of life changes.

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 data supports the effectiveness of the treatment Microprocessor (MP) Knee Prosthesis, Vanderbilt Powered Knee-Ankle Prosthesis for transfemoral amputees?

Research shows that microprocessor-controlled prosthetic knees help improve walking ability and quality of life for people with above-knee amputations. These advanced prostheses provide better balance and safety, making it easier for users to move around in their daily lives. ^{1 2 3 4 5}

Is the microprocessor knee prosthesis safe for humans?

Research indicates that microprocessor-controlled knee prostheses are generally safe for humans, with studies showing benefits in safety and performance for users, including those with lower activity levels. ^{1 2 3 6 7}

How is the Powered Knee-Ankle Prosthesis and Microprocessor Knee Prosthesis treatment different from other treatments for transfemoral amputees?

This treatment is unique because it combines a microprocessor-controlled knee with a powered knee-ankle prosthesis, which can improve mobility and quality of life by adapting to different terrains and enhancing balance and energy efficiency. Unlike traditional mechanical prostheses, these advanced devices use technology to provide more natural movement and better support for transfemoral amputees. ^{1 2 4 5 6}

Research Team

Arun Jayaraman, PT, PhD

Principal Investigator

Shirley Ryan AbilityLab

Eligibility Criteria

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

I have lost one leg at or above the knee.

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

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

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

Treatment Details

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.

Participant Groups

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+

Findings from Research

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]

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 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]

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]

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 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]

References

1. Italy 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. [2023]

2. Netherlands pubmed.ncbi.nlm.nih.gov

The comparison of transfemoral amputees using mechanical and microprocessor- controlled prosthetic knee under different walking speeds: A randomized cross-over trial. [2019]

3. England pubmed.ncbi.nlm.nih.gov

The effect of microprocessor controlled exo-prosthetic knees on limited community ambulators: systematic review and meta-analysis. [2023]

4. France 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. [2022]

5. United States pubmed.ncbi.nlm.nih.gov

A Comparison of Control Strategies in Commercial and Research Knee Prostheses. [2021]

6. France 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. [2023]

7. England 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. [2018]