OPK: Use of Passive, Adaptive, and Active Prosthetic Knees in Persons With Unilateral, Transfemoral Amputation
Study Details
Study Description
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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
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.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Prosthetic knee 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)
Prosthetic knee with active control system.
Other Names:
Device: Adaptive knee (Ossur Rheo)
Prosthetic knee with adaptive control system.
Other Names:
Device: Passive knee (Various manufacturers)
Prosthetic knee with mechanical control system.
Other Names:
|
Outcome Measures
Primary Outcome Measures
- Timed Up and Go [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 performance test that measures rising from a chair, walking 3m, and returning to a seated position.
- Timed Ramp Test [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 performance test that involves walking up and down a 14ft ramp.
- Timed Stair Test [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 performance test that involves walking up and down 6 steps.
- Step activity [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)]
Average daily step counts measured by an accelerometer-based device.
- Obstacle course time [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)]
Time to walk a 1/2-mile outdoor walking course.
Secondary Outcome Measures
- Reported Falls [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)]
Self-report phone survey.
- Prosthesis Evaluation Questionnaire (PEQ) [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)]
Self-report computerized survey (12 questions)
- Activities Specific Balance Confidence Scale (ABC) [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)]
Self-report computerized survey (18 questions).
- Patient Reported Outcomes Measurement Information System (PROMIS) [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)]
Self-report computerized questionnaire with 8-14 questions per domain. Includes Physical Function, Fatigue, and General Health subdomains.
Eligibility Criteria
Criteria
Inclusion Criteria:
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age 45 - 75
-
body weight less than 275lbs
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unilateral amputation between the hip and knee
-
amputation due to non-vascular causes
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no other major limb amputations
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amputation occurred at least 2 years prior
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stable limb volume (i.e., at least 6 months on an unmodified prosthetic socket)
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intact skin tissue without open wounds or sores for at least 2 months
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physiologically stable medical condition (i.e., non-degenerative)
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possession and regular (i.e., daily) use of a prosthesis with a prosthetic knee with non-microprocessor (i.e., mechanical or fluid) stance control
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Medicare functional classification level (MFCL or "K-level") 3
Exclusion Criteria:
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expect to receive or are expected to require a replacement prosthetic socket within 15 months
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complete reliance on an assistive device (i.e., cane or walker) for ambulation
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | University of Washington | Seattle | Washington | United States | 98195 |
Sponsors and Collaborators
- University of Washington
- Össur Ehf
Investigators
- Principal Investigator: Brian Hafner, PhD, University of Washington
Study Documents (Full-Text)
None provided.More Information
Additional Information:
Publications
None provided.- 40660-A
- A62089