Amputation
Conditions
Keywords
Trans-femoral, Prosthetic knee, Amputees
Brief summary
The aim of this investigation is to evaluate the efficacy of the investigational device regarding performance improvements and satisfaction in descending activities for moderate to high active prosthesis users within the intended population for the investigational device. Additionally, the overall satisfaction for activities of daily living will be evaluated after a certain time of use (4 weeks home use).
Detailed description
This investigation is a non-randomized single group repeated measures open label prospective design with observational and self-report measures. Two scheduled study events are planned for amputee subjects, with 4 weeks between visits.
Interventions
Microprocessor controlled prosthetic knee (MPK)
Sponsors
Study design
Intervention model description
The test will be a non-randomized single group repeated measures open label prospective design with observational and self-report measures.
Eligibility
Inclusion criteria
* 45Kg\< body weight \< 136Kg * Cognitive ability to understand all instructions and questionnaires in the study; * Unilateral TF/KD amputees that are regular prosthesis users for at least 3 months * Current MPK users (passive MPKs only) regularly performing descent activities (stairs/ramps) * Age ≥ 18 years * Willing and able to participate in the study and follow the protocol
Exclusion criteria
* Users with stump pain * Users with socket problems * Pregnant Users * Users using Power Knee, Kenevo or mechanical knees as their prescribed prosthesis * Alignment that cannot be matched with the Navii setup, as described in Instructions for use. * Osseointegration
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Satisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | After 4 weeks of use | Satisfaction on ramp descent with the new MPK compared to prescribed device In-house questionnaire and Scale used: worse, same, better. |
| Satisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | After 4 weeks of use | Satisfaction on stair descent with the new MPK compared to prescribed device In-house questionnaire and Scale used: worse, same, better |
| Satisfaction on Level Ground Walking Activity | After 4 weeks of use | Satisfaction on level ground walking activity with the new MPK compared to prescribed device In-house questionnaire and Scale used: worse, same, better |
| Change in Overall Satisfaction From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Baseline and After 4 weeks of use | The PEQ (Prosthesis Evaluation Questionnaire) assesses the quality of life and satisfaction for prosthetic users using a visual analog scale from 0 to 100, where higher scores indicate more positive responses. Only certain subsets were used, including the ambulation subscale, satisfaction and safety questions, and utility questions. The hypothesis tested was that the new MPK has a 95% chance of not negatively affecting overall satisfaction. If scores in Visit 2 (with the investigational device) were higher than in Visit 1 (with the prescribed device), it would support the hypothesis. The confidence interval bars represented in graph were visually compared to the margin of non-inferiority. No further statistical analysis was done. |
| Change in Distance Walked During 2-Minute Walk Test (2MWT) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Baseline and After 4 weeks of use | Average difference in distance walked in 2MWT with the new MPK compared to comparator (prescribed device) User walk for 2 minutes in their self selected walking speed on a 30 meter track. The hypothesis being tested is that the new MPK has a 95% probability of not negatively affecting the distance walked on 2MWT. For this hypothesis, if scores in visit 2 (subjects using the investigational device) were higher than in visit 1 (subjects using their prescribed device), the difference of Visit 2 - Visit 1 would be positive and would therefore support the corresponding hypothesis. The confidence interval bars represented in graph were visually compared to the margin of non-inferiority. No further statistical analysis was done. |
| Change in Time for the Timed Up and Go Test (TUG) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Baseline and After 4 weeks of use | The TUG test is a simple evaluative test used to measure functional mobility and assess fall risk. Reduction in time (measured in seconds) to complete indicates improvement in mobility. Average time needed to perform the TUG with the new MPK compared to comparator (prescribed device). The hypothesis being tested is that the new MPK has a 95% probability of not negatively affecting the time needed to complete the TUG. For this hypothesis, if the completion times of the TUG during the Visit 2 (subjects using the investigational device) were lower than the ones in Visit 1 (subjects using their prescribed device), the difference of Visit 2 - Visit 1 would be negative and would therefore support the corresponding hypothesis. The confidence interval bars represented in graph were visually compared to the margin of non-inferiority. No further statistical analysis was done. |
| Change in T-score for the Prosthetic Limb Users Survey of Mobility (PLUS-M) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Baseline and After 4 weeks of use | Ability to ambulate over typical environmental obstacles is measured by the PLUS-M, using the T-score with the new MPK compared to the comparator (prescribed device). The PLUS-M is a self-report tool for assessing mobility in adults with lower limb amputation. The PLUS-M produces a T-score, which is standardized with a mean of 50 and a standard deviation of 10. Higher T-scores indicate greater mobility, with scores ranging from 17.5 to 76.6, based on responses to 44 questions. Only T-scores should be reported, as they are valid and comparable, unlike raw scores. The hypothesis being tested is that the new MPK has a 95% probability of not negatively affecting the PLUS-M score. If Visit 2 scores (using the investigational device) are higher than Visit 1 scores (using the prescribed device), the positive difference supports the hypothesis. The confidence interval bars represented in graph were visually compared to the margin of non-inferiority. No further statistical analysis was done. |
| Change in Activities-Specific Balance Confidence Score (ABC) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Baseline and After 4 weeks of use | The ABC-scale is a 16-item questionnaire measuring confidence in performing ambulatory activities without falling, scored from 0 (no confidence) to 100 (full confidence). Cut-off scores define physical functioning: below 50% indicates low, 50-80% moderate, and above 80% high functioning. The hypothesis is that the new MPK has a 95% chance of not negatively impacting the ABC score. If Visit 2 scores (using the investigational device) exceed Visit 1 scores (using the prescribed device), it supports the hypothesis. Confidence interval bars in the graph were visually compared to the margin of non-inferiority, with no additional statistical analysis conducted. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Exploratory Testing of a New Prosthetic Knee Navii Knee: Microprocessor controlled prosthetic knee (MPK) | 11 |
| Total | 11 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Withdrawal by Subject | 1 |
Baseline characteristics
| Characteristic | Exploratory Testing of a New Prosthetic Knee | — |
|---|---|---|
| Age, Categorical <=18 years | 0 Participants | — |
| Age, Categorical >=65 years | 1 Participants | — |
| Age, Categorical Between 18 and 65 years | 10 Participants | — |
| Amputation level Transfemoral | 11 Participants | — |
| Race and Ethnicity Not Collected | — | — Participants |
| Region of Enrollment United States | 11 Participants | — |
| Sex: Female, Male Female | 3 Participants | — |
| Sex: Female, Male Male | 8 Participants | — |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 11 |
| other Total, other adverse events | 2 / 11 |
| serious Total, serious adverse events | 0 / 11 |
Outcome results
Change in Activities-Specific Balance Confidence Score (ABC) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use
The ABC-scale is a 16-item questionnaire measuring confidence in performing ambulatory activities without falling, scored from 0 (no confidence) to 100 (full confidence). Cut-off scores define physical functioning: below 50% indicates low, 50-80% moderate, and above 80% high functioning. The hypothesis is that the new MPK has a 95% chance of not negatively impacting the ABC score. If Visit 2 scores (using the investigational device) exceed Visit 1 scores (using the prescribed device), it supports the hypothesis. Confidence interval bars in the graph were visually compared to the margin of non-inferiority, with no additional statistical analysis conducted.
Time frame: Baseline and After 4 weeks of use
Population: 4 subjects had magnetorheological working MPK, 6 subjects had a hydraulic one.
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Exploratory Testing of a New Prosthetic Knee | Change in Activities-Specific Balance Confidence Score (ABC) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Rheo Knee users | 2.3 score on a scale |
| Exploratory Testing of a New Prosthetic Knee | Change in Activities-Specific Balance Confidence Score (ABC) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Hydraulic users | 5.4 score on a scale |
| Exploratory Testing of a New Prosthetic Knee | Change in Activities-Specific Balance Confidence Score (ABC) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | All users | 4.1 score on a scale |
Change in Distance Walked During 2-Minute Walk Test (2MWT) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use
Average difference in distance walked in 2MWT with the new MPK compared to comparator (prescribed device) User walk for 2 minutes in their self selected walking speed on a 30 meter track. The hypothesis being tested is that the new MPK has a 95% probability of not negatively affecting the distance walked on 2MWT. For this hypothesis, if scores in visit 2 (subjects using the investigational device) were higher than in visit 1 (subjects using their prescribed device), the difference of Visit 2 - Visit 1 would be positive and would therefore support the corresponding hypothesis. The confidence interval bars represented in graph were visually compared to the margin of non-inferiority. No further statistical analysis was done.
Time frame: Baseline and After 4 weeks of use
Population: 4 subjects had magnetorheological working MPK, 6 subjects had a hydraulic one.
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Exploratory Testing of a New Prosthetic Knee | Change in Distance Walked During 2-Minute Walk Test (2MWT) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Rheo Knee users | 2.43 meters |
| Exploratory Testing of a New Prosthetic Knee | Change in Distance Walked During 2-Minute Walk Test (2MWT) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Hydraulic users | -1.8 meters |
| Exploratory Testing of a New Prosthetic Knee | Change in Distance Walked During 2-Minute Walk Test (2MWT) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | All users | -0.1 meters |
Change in Overall Satisfaction From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use
The PEQ (Prosthesis Evaluation Questionnaire) assesses the quality of life and satisfaction for prosthetic users using a visual analog scale from 0 to 100, where higher scores indicate more positive responses. Only certain subsets were used, including the ambulation subscale, satisfaction and safety questions, and utility questions. The hypothesis tested was that the new MPK has a 95% chance of not negatively affecting overall satisfaction. If scores in Visit 2 (with the investigational device) were higher than in Visit 1 (with the prescribed device), it would support the hypothesis. The confidence interval bars represented in graph were visually compared to the margin of non-inferiority. No further statistical analysis was done.
Time frame: Baseline and After 4 weeks of use
Population: 4 subjects had magnetorheological working MPK, 6 subjects had a hydraulic one.
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Exploratory Testing of a New Prosthetic Knee | Change in Overall Satisfaction From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Rheo Knee users | 2.6 units on a scale |
| Exploratory Testing of a New Prosthetic Knee | Change in Overall Satisfaction From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Hydraulic users | 7.4 units on a scale |
| Exploratory Testing of a New Prosthetic Knee | Change in Overall Satisfaction From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | All users | 5.5 units on a scale |
Change in Time for the Timed Up and Go Test (TUG) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use
The TUG test is a simple evaluative test used to measure functional mobility and assess fall risk. Reduction in time (measured in seconds) to complete indicates improvement in mobility. Average time needed to perform the TUG with the new MPK compared to comparator (prescribed device). The hypothesis being tested is that the new MPK has a 95% probability of not negatively affecting the time needed to complete the TUG. For this hypothesis, if the completion times of the TUG during the Visit 2 (subjects using the investigational device) were lower than the ones in Visit 1 (subjects using their prescribed device), the difference of Visit 2 - Visit 1 would be negative and would therefore support the corresponding hypothesis. The confidence interval bars represented in graph were visually compared to the margin of non-inferiority. No further statistical analysis was done.
Time frame: Baseline and After 4 weeks of use
Population: 4 subjects had magnetorheological working MPK, 6 subjects had a hydraulic one.
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Exploratory Testing of a New Prosthetic Knee | Change in Time for the Timed Up and Go Test (TUG) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Rheo Knee users | -0.1 time in seconds |
| Exploratory Testing of a New Prosthetic Knee | Change in Time for the Timed Up and Go Test (TUG) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Hydraulic users | -0.2 time in seconds |
| Exploratory Testing of a New Prosthetic Knee | Change in Time for the Timed Up and Go Test (TUG) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | All users | -0.2 time in seconds |
Change in T-score for the Prosthetic Limb Users Survey of Mobility (PLUS-M) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use
Ability to ambulate over typical environmental obstacles is measured by the PLUS-M, using the T-score with the new MPK compared to the comparator (prescribed device). The PLUS-M is a self-report tool for assessing mobility in adults with lower limb amputation. The PLUS-M produces a T-score, which is standardized with a mean of 50 and a standard deviation of 10. Higher T-scores indicate greater mobility, with scores ranging from 17.5 to 76.6, based on responses to 44 questions. Only T-scores should be reported, as they are valid and comparable, unlike raw scores. The hypothesis being tested is that the new MPK has a 95% probability of not negatively affecting the PLUS-M score. If Visit 2 scores (using the investigational device) are higher than Visit 1 scores (using the prescribed device), the positive difference supports the hypothesis. The confidence interval bars represented in graph were visually compared to the margin of non-inferiority. No further statistical analysis was done.
Time frame: Baseline and After 4 weeks of use
Population: 4 subjects had magnetorheological working MPK, 6 subjects had a hydraulic one.
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Exploratory Testing of a New Prosthetic Knee | Change in T-score for the Prosthetic Limb Users Survey of Mobility (PLUS-M) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Rheo Knee users | 3.8 T-score |
| Exploratory Testing of a New Prosthetic Knee | Change in T-score for the Prosthetic Limb Users Survey of Mobility (PLUS-M) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | Hydraulic users | 20.0 T-score |
| Exploratory Testing of a New Prosthetic Knee | Change in T-score for the Prosthetic Limb Users Survey of Mobility (PLUS-M) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device Use | All users | 13.5 T-score |
Satisfaction on Level Ground Walking Activity
Satisfaction on level ground walking activity with the new MPK compared to prescribed device In-house questionnaire and Scale used: worse, same, better
Time frame: After 4 weeks of use
Population: 4 subjects had magnetorheological working MPK, 6 subjects had a hydraulic one.
| Arm | Measure | Group | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|---|
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Level Ground Walking Activity | Rheo Knee users | Worse | 0 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Level Ground Walking Activity | Rheo Knee users | Same | 4 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Level Ground Walking Activity | Rheo Knee users | Better | 0 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Level Ground Walking Activity | Hydraulic users | Worse | 0 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Level Ground Walking Activity | Hydraulic users | Same | 6 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Level Ground Walking Activity | Hydraulic users | Better | 0 Participants |
Satisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)
Satisfaction on ramp descent with the new MPK compared to prescribed device In-house questionnaire and Scale used: worse, same, better.
Time frame: After 4 weeks of use
Population: 4 subjects had magnetorheological working MPK, 6 subjects had a hydraulic one.
| Arm | Measure | Group | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|---|
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | Rheo Knee Users | worse | 1 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | Rheo Knee Users | same | 0 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | Rheo Knee Users | better | 3 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | Hydraulic Users | worse | 4 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | Hydraulic Users | same | 1 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | Hydraulic Users | better | 1 Participants |
Satisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)
Satisfaction on stair descent with the new MPK compared to prescribed device In-house questionnaire and Scale used: worse, same, better
Time frame: After 4 weeks of use
Population: 4 subjects had magnetorheological working MPK, 6 subjects had a hydraulic one.
| Arm | Measure | Group | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|---|
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | In-house questionnaire Rheo Knee Users | better | 3 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | In-house questionnaire Rheo Knee Users | worse | 0 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | In-house questionnaire Rheo Knee Users | same | 1 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | In-house questionnaire Hydraulic Users | worse | 5 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | In-house questionnaire Hydraulic Users | same | 0 Participants |
| Exploratory Testing of a New Prosthetic Knee | Satisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK) | In-house questionnaire Hydraulic Users | better | 1 Participants |