Clinical Investigation (Beta) of a New Developed Prosthetic Knee

NCT06748729 | Completed Results FDA Device

• 1 other identifier: CIP2023120529
• Study Type: interventional
• Target: 11
• Locations: 1 country
• Sites: 1

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).

Conditions

Amputation

Keywords

Trans-femoral; Prosthetic knee; Amputees

Outcome Measures

Primary Outcomes (8)

• 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.

  After 4 weeks of use

• 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

  After 4 weeks of use

• 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

  After 4 weeks of use

• 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.

  Baseline and After 4 weeks of use

• 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.

  Baseline and After 4 weeks of use

• 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.

  Baseline and After 4 weeks of use

• 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.

  Baseline and After 4 weeks of use

• 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.

  Baseline and After 4 weeks of use

Study Arms (1)

Exploratory testing of a new prosthetic knee

EXPERIMENTAL

The investigational device is provided to subjects, who then use it as their main prosthesis for a period of 4 weeks prior to returning for data collection on the device.

Device: Navii Knee

Interventions

Navii Knee DEVICE

Microprocessor controlled prosthetic knee (MPK)

Exploratory testing of a new prosthetic knee

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Kg\< 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Össur Iceland ehf: lead

Study Sites (1)

Össur Orlando

Orlando, Florida, 32819, United States

Location

Results Point of Contact

• Title: Laurine Roussillon
• Organization: Össur Iceland ehf.

lroussillon@ossur.com

+3548221812

Study Officials

• Kurt N. Gruben

  Össur Americas

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: The test will be a non-randomized single group repeated measures open label prospective design with observational and self-report measures.

Study Record Dates

• First Submitted: April 17, 2024
• First Posted: December 27, 2024
• Study Start: February 26, 2024
• Primary Completion: March 28, 2024
• Study Completion: March 28, 2024
• Last Updated: September 4, 2025
• Results First Posted: September 4, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)