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Clinical Investigation (Beta) of a New Developed Prosthetic Knee

Investigation on Performance of a New Developed Prosthetic Knee

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06748729
Enrollment
11
Registered
2024-12-27
Start date
2024-02-26
Completion date
2024-03-28
Last updated
2025-09-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Amputation

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

DEVICENavii Knee

Microprocessor controlled prosthetic knee (MPK)

Sponsors

Össur Iceland ehf
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE

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

Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No

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

MeasureTime frameDescription
Satisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)After 4 weeks of useSatisfaction 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 useSatisfaction 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 ActivityAfter 4 weeks of useSatisfaction 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 UseBaseline and After 4 weeks of useThe 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 UseBaseline and After 4 weeks of useAverage 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 UseBaseline and After 4 weeks of useThe 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 UseBaseline and After 4 weeks of useAbility 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 UseBaseline and After 4 weeks of useThe 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

ArmCount
Exploratory Testing of a New Prosthetic Knee
Navii Knee: Microprocessor controlled prosthetic knee (MPK)
11
Total11

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyWithdrawal by Subject1

Baseline characteristics

CharacteristicExploratory 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 Transfemoral11 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 typeEG000
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

Primary

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.

ArmMeasureGroupValue (MEAN)
Exploratory Testing of a New Prosthetic KneeChange in Activities-Specific Balance Confidence Score (ABC) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseRheo Knee users2.3 score on a scale
Exploratory Testing of a New Prosthetic KneeChange in Activities-Specific Balance Confidence Score (ABC) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseHydraulic users5.4 score on a scale
Exploratory Testing of a New Prosthetic KneeChange in Activities-Specific Balance Confidence Score (ABC) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseAll users4.1 score on a scale
Primary

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.

ArmMeasureGroupValue (MEAN)
Exploratory Testing of a New Prosthetic KneeChange in Distance Walked During 2-Minute Walk Test (2MWT) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseRheo Knee users2.43 meters
Exploratory Testing of a New Prosthetic KneeChange in Distance Walked During 2-Minute Walk Test (2MWT) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseHydraulic users-1.8 meters
Exploratory Testing of a New Prosthetic KneeChange in Distance Walked During 2-Minute Walk Test (2MWT) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseAll users-0.1 meters
Primary

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.

ArmMeasureGroupValue (MEAN)
Exploratory Testing of a New Prosthetic KneeChange in Overall Satisfaction From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseRheo Knee users2.6 units on a scale
Exploratory Testing of a New Prosthetic KneeChange in Overall Satisfaction From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseHydraulic users7.4 units on a scale
Exploratory Testing of a New Prosthetic KneeChange in Overall Satisfaction From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseAll users5.5 units on a scale
Primary

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.

ArmMeasureGroupValue (MEAN)
Exploratory Testing of a New Prosthetic KneeChange in Time for the Timed Up and Go Test (TUG) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseRheo Knee users-0.1 time in seconds
Exploratory Testing of a New Prosthetic KneeChange in Time for the Timed Up and Go Test (TUG) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseHydraulic users-0.2 time in seconds
Exploratory Testing of a New Prosthetic KneeChange in Time for the Timed Up and Go Test (TUG) From Baseline With Prescribed Device to After 4 Weeks of Investigational Device UseAll users-0.2 time in seconds
Primary

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.

ArmMeasureGroupValue (MEAN)
Exploratory Testing of a New Prosthetic KneeChange 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 UseRheo Knee users3.8 T-score
Exploratory Testing of a New Prosthetic KneeChange 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 UseHydraulic users20.0 T-score
Exploratory Testing of a New Prosthetic KneeChange 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 UseAll users13.5 T-score
Primary

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.

ArmMeasureGroupCategoryValue (COUNT_OF_PARTICIPANTS)
Exploratory Testing of a New Prosthetic KneeSatisfaction on Level Ground Walking ActivityRheo Knee usersWorse0 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Level Ground Walking ActivityRheo Knee usersSame4 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Level Ground Walking ActivityRheo Knee usersBetter0 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Level Ground Walking ActivityHydraulic usersWorse0 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Level Ground Walking ActivityHydraulic usersSame6 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Level Ground Walking ActivityHydraulic usersBetter0 Participants
Primary

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.

ArmMeasureGroupCategoryValue (COUNT_OF_PARTICIPANTS)
Exploratory Testing of a New Prosthetic KneeSatisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)Rheo Knee Usersworse1 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)Rheo Knee Userssame0 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)Rheo Knee Usersbetter3 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)Hydraulic Usersworse4 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)Hydraulic Userssame1 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Ramp Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)Hydraulic Usersbetter1 Participants
Primary

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.

ArmMeasureGroupCategoryValue (COUNT_OF_PARTICIPANTS)
Exploratory Testing of a New Prosthetic KneeSatisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)In-house questionnaire Rheo Knee Usersbetter3 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)In-house questionnaire Rheo Knee Usersworse0 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)In-house questionnaire Rheo Knee Userssame1 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)In-house questionnaire Hydraulic Usersworse5 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)In-house questionnaire Hydraulic Userssame0 Participants
Exploratory Testing of a New Prosthetic KneeSatisfaction on Stair Descent With the New Microprocessor-controlled Prosthetic Knee (MPK)In-house questionnaire Hydraulic Usersbetter1 Participants

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026