Use of Passive, Adaptive, and Active Prosthetic Knees in Persons With Unilateral, Transfemoral Amputation

Study Overview
=================
Brief Summary
-----------------
The goals of this study are to assess measured, observed, and self-reported outcomes achieved through the use of passive (mechanical), active(motorized) and adaptive (magnetorheological) prosthetic knee control systems in individuals with unilateral, transfemoral amputation.

Detailed Description
-----------------
An interrupted time-series trial with pre/post baseline assessments, randomized crossover of interventions, and within-phase repeated measures is used to evaluate and compare the effectiveness of the Össur Power Knee II and the Össur Rheo Knee in individuals with unilateral, transfemoral amputation. A rigorous and clinically-meaningful experimental protocol is applied to verify study participants receive appropriate training, experience, and assessment in each knee condition. A suite of standardized and ad-hoc physical performance tests, patient-reported questionnaires, and monitoring technologies were carefully selected to assess important, clinically-relevant participant outcomes. Comparative effectiveness of three prosthetic knee interventions are evaluated using direct measurement (i.e., timed tests), observed clinical ratings (i.e., subjective assessments of gait quality) and self-report instruments (i.e., health status surveys). Analyses will focus on identifying differences between control system technologies inherent to each type of prosthetic knee (i.e., passive [mechanical], adaptive [magnetorheological], and active [power]). Outcomes will be used to establish recommendations for which activities and patients knees are most appropriate or likely to produce a desired effect.

Official Title
-----------------
Outcomes Associated With Use of Passive, Adaptive, and Active Prosthetic Knees in Persons With Unilateral, Transfemoral Amputation: a Randomized Crossover Trial

Conditions
-----------------
Transfemoral Amputation

Intervention / Treatment
-----------------
* Device: Active knee (Ossur Power Knee II)
* Device: Adaptive knee (Ossur Rheo)
* Device: Passive knee (Various manufacturers)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: age 45 - 75 body weight less than 275lbs unilateral amputation between the hip and knee amputation due to non-vascular causes no other major limb amputations amputation occurred at least 2 years prior stable limb volume (i.e., at least 6 months on an unmodified prosthetic socket) intact skin tissue without open wounds or sores for at least 2 months physiologically stable medical condition (i.e., non-degenerative) possession and regular (i.e., daily) use of a prosthesis with a prosthetic knee with non-microprocessor (i.e., mechanical or fluid) stance control Medicare functional classification level (MFCL or K-level) 3 Exclusion Criteria: expect to receive or are expected to require a replacement prosthetic socket within 15 months complete reliance on an assistive device (i.e., cane or walker) for ambulation

Ages Eligible for Study
-----------------
Minimum Age: 45 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Intervention Model: Single Group Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Prosthetic knee<br>Subjects crossed over between interventions (three different prosthetic knees). Knee conditions include 1) Active knee (Ossur Power Knee II); 2) Adaptive knee (Ossur Rheo); and 3) Passive knee (Various manufacturers) | Device: Active knee (Ossur Power Knee II)<br>* Prosthetic knee with active control system.<br>* Other names: Motorized knee;Device: Adaptive knee (Ossur Rheo)<br>* Prosthetic knee with adaptive control system.<br>* Other names: Microprocessor knee;Device: Passive knee (Various manufacturers)<br>* Prosthetic knee with mechanical control system.<br>* Other names: Pneumatic knee;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Timed Up and Go | Timed performance test that measures rising from a chair, walking 3m, and returning to a seated position. | Change from Baseline (mean score at weeks 1, 2, 3, and 4) to Follow-Up (mean score at weeks 8, 12, 16, 20, 24, and 28) | 
| Timed Ramp Test | Timed performance test that involves walking up and down a 14ft ramp. | Change from Baseline (mean score at weeks 1, 2, 3, and 4) to Follow-Up (mean score at weeks 8, 12, 16, 20, 24, and 28) | 
| Timed Stair Test | Timed performance test that involves walking up and down 6 steps. | Change from Baseline (mean score at weeks 1, 2, 3, and 4) to Follow-Up (mean score at weeks 8, 12, 16, 20, 24, and 28) | 
| Step activity | Average daily step counts measured by an accelerometer-based device. | Change from Baseline (mean score at weeks 1, 2, 3, and 4) to Follow-Up (mean score at weeks 8, 12, 16, 20, 24, and 28) | 
| Obstacle course time | Time to walk a 1/2-mile outdoor walking course. | Change from Baseline (mean score at weeks 1, 2, 3, and 4) to Follow-Up (mean score at weeks 8, 12, 16, 20, 24, and 28) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reported Falls | Self-report phone survey. | Change from Baseline (mean score at weeks 1, 2, 3, and 4) to Follow-Up (mean score at weeks 8, 12, 16, 20, 24, and 28) | 
| Prosthesis Evaluation Questionnaire (PEQ) | Self-report computerized survey (12 questions) | Change from Baseline (mean score at weeks 1, 2, 3, and 4) to Follow-Up (mean score at weeks 8, 12, 16, 20, 24, and 28) | 
| Activities Specific Balance Confidence Scale (ABC) | Self-report computerized survey (18 questions). | Change from Baseline (mean score at weeks 1, 2, 3, and 4) to Follow-Up (mean score at weeks 8, 12, 16, 20, 24, and 28) | 
| Patient Reported Outcomes Measurement Information System (PROMIS) | Self-report computerized questionnaire with 8-14 questions per domain. Includes Physical Function, Fatigue, and General Health subdomains. | Change from Baseline (mean score at weeks 1, 2, 3, and 4) to Follow-Up (mean score at weeks 8, 12, 16, 20, 24, and 28) |