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

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

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.

Study Overview

• Status: Completed
• Conditions: Transfemoral Amputation
• Intervention / Treatment: Device: Active knee (Ossur Power Knee II); Device: Adaptive knee (Ossur Rheo); Device: Passive knee (Various manufacturers)

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 Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Washington
    • Seattle, Washington, United States, 98195
      • University of Washington

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 45 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: Single

Number of Arms

1

Arms and Interventions

Participant Group / 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: Power knee; Motorized knee; Device: Adaptive knee (Ossur Rheo); Prosthetic knee with adaptive control system.; Other Names: Magnetorheological knee; Microprocessor knee; Device: Passive knee (Various manufacturers); Prosthetic knee with mechanical control system.; Other Names: Mechanical knee; Hydraulic knee; 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)

Collaborators and Investigators

• Sponsor: University of Washington
• Collaborators: Össur Ehf
• Investigators: Principal Investigator: Brian Hafner, PhD, University of Washington

Publications and helpful links

General Publications

• Hafner BJ, Askew RL. Physical performance and self-report outcomes associated with use of passive, adaptive, and active prosthetic knees in persons with unilateral, transfemoral amputation: Randomized crossover trial. J Rehabil Res Dev. 2015;52(6):677-700. doi: 10.1682/JRRD.2014.09.0210.

Helpful Links

• Study results published in the Journal of Rehabilitation Research and Development

Study record dates

Study Major Dates

• Study Start: June 1, 2011
• Primary Completion (Actual): September 1, 2013
• Study Completion (Actual): September 1, 2013

Study Registration Dates

• First Submitted: July 29, 2014
• First Submitted That Met QC Criteria: August 14, 2014
• First Posted (Estimate): August 18, 2014

Study Record Updates

• Last Update Posted (Estimate): December 28, 2015
• Last Update Submitted That Met QC Criteria: December 23, 2015
• Last Verified: December 1, 2015

More Information

Terms related to this study

• Other Study ID Numbers: 40660-A; A62089 (Other Identifier: University of Washington)