Evaluation of Transfemoral Amputees When Transitioning From a Mechanical to a Microprocessor Prosthetic Knee

NCT03829202 | Completed

• 1 other identifier: MRC_Ossur_MPK
• Study Type: interventional
• Target: 7
• Locations: 0 countries
• Sites: N/A

Brief Summary

The central hypothesis of this proposal is that real-life benefits of microprocessor knees (MPK) are largely underappreciated because of the lack of sensitive and ecologically valid methods for evaluating motor performance. This makes it difficult to justify MPKs for many amputees who could benefit from it. Using recently developed outcome measures shown to be more effective in evaluating prosthesis users than commonly employed metrics, 7 transfemoral prosthesis users who exclusivity utilize a non-microprocessor mechanical knee were evaluated as they transitioned to and from an MPK in an ABA/BAB single subject design protocol. Subjects were also evaluated with existing clinical measures established for lower limb amputees.

Conditions

Amputation of Lower Limb Above Knee

Outcome Measures

Primary Outcomes (7)

• Stride Length-Cadence Relationship

  The stride length-cadence relationship measures the coordination between the temporal and spatial gait parameters over a range of walking speeds. Greater correlation represents improved gait coordination.

  Weekly for the duration of the study, approximately 15 weeks

• Dual-task residual standard deviation

  Subject's will walk at their self-selected speed while performing 1 of 4 cognitive tasks. Tasks include: serial subtraction, listing words in a specific category, reciting every other letter of the alphabet, repeating a list of numbers. The change in stride length and cadence were compared to baseline gait (walking at 3 speeds: normal, slow, fast) using the residual standard deviation (RSD) method. RSD evaluates gait variability while accounting for changes in velocity.

  Weekly for the duration of the study, approximately 15 weeks

• Prosthetic Single Limb Support

  Prosthesis users are reported to spend less time in single limb support on the prosthetic side due to a lack of stability. Improved stability with an MPK could increase prosthetic single limb support. The outcome will be measured over a range of walking speeds using an instrumented walkway.

  Weekly for the duration of the study, approximately 15 weeks

• Hip/knee/ankle joint angles

  Joint angle range of motion and angle at critical instances will be measured using 3D motion capture to evaluate changes in gait kinematics while using each knee.

  At baseline and end of each phase (5 weeks) for the duration of the study, approximately 15 weeks

• 6-minute walk test

  The 6-Min Walk Test is a functional walking test that is considered to be reflective of performance of activities of daily living. Participants will be instructed to walk as far as they can in 6 min along a wide, 30.5m (100 ft) corridor with sufficient additional space for unobstructed 180° turns at each end. Participants are free to pause at any time during the test; however, the time will continue to run. The distance walked during 6-Min Walk Test will be recorded to the nearest foot.

  At baseline and end of each phase (5 weeks) for the duration of the study, approximately 15 weeks

• Berg Balance Scale

  The Berg Balance Scale has high validity and reliability in assessing balance in prosthesis users. The Berg Balance Scale consists of 14 functional balance tasks scored from 0 to 4, with a max score of 56. It will be administered by a physical therapist experienced with the measure and working with lower-limb amputees.

  At baseline and end of each phase (5 weeks) for the duration of the study, approximately 15 weeks

• Amputee Mobility Predictor

  The Amputee Mobility Predictor is designed specifically for assessing amputees before or after receiving a prosthesis and the score can be used to assign Medicare Functional Class Level (K-Level, secondary outcome). The 20 tasks include assessments of balance and mobility (most tasks scored from 0-2, maximum score 47) and will be administered by a certified prosthetist. Although comparison between devices is not its primary intent, the Amputee Mobility Predictor has widespread use among practitioners and researchers, providing a consistent means to compare results between studies.

  At baseline and end of each phase (5 weeks) for the duration of the study, approximately 15 weeks

Secondary Outcomes (11)

• Gait Velocity

  Weekly for the duration of the study, approximately 15 weeks

• Dual-task cognitive performance

  Weekly for the duration of the study, approximately 15 weeks

• Dual-task difficulty

  Weekly for the duration of the study, approximately 15 weeks

• Step Width

  Weekly for the duration of the study, approximately 15 weeks

• Prosthetic limb double support

  Weekly for the duration of the study, approximately 15 weeks

Study Arms (2)

A-B-A Group

EXPERIMENTAL

Daily use of own mechanical knee for 4 weeks (A), followed by RheoKnee microprocessor prosthetic knee for 4 weeks (B), and concluding with own mechanical knee for 4 weeks (A).

Device: Own mechanical knee; Device: RheoKnee microprocessor prosthetic knee

B-A-B Group

EXPERIMENTAL

Daily use of RheoKnee microprocessor prosthetic knee for 4 weeks (B), followed by own mechanical knee for 4 weeks (A), and concluding with RheoKnee microprocessor prosthetic knee for 4 weeks (B).

Device: Own mechanical knee; Device: RheoKnee microprocessor prosthetic knee

Interventions

Own mechanical knee DEVICE

Daily use of own mechanical knee

A-B-A Group; B-A-B Group

RheoKnee microprocessor prosthetic knee DEVICE

Daily use of RheoKnee microprocessor prosthetic knee

Also known as: MPK

A-B-A Group; B-A-B Group

Eligibility Criteria

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

You may qualify if:

• Unilateral above-knee amputation
• Exclusive use of an non-microprocessor knee for more than 1 year
• Comfortable socket fit
• No skin breakdown on the residual limb
• Medicare functional classification level 2 or 3
• Ability to read or understand English
• Ability to walk 10 m with or without an assistive device

You may not qualify if:

• Cognitive or general health problems that would prevent participation in the study
• Physical limitations on the non amputated side

Sponsors & Collaborators

• Methodist Rehabilitation Center: lead
• Össur Iceland ehf: collaborator

Related Publications (1)

• Howard CL, Wallace C, Perry B, Stokic DS. The utility of the single-subject method for comparison of temporal-spatial gait changes between a microprocessor and non-microprocessor prosthetic knees. Prosthet Orthot Int. 2020 Jun;44(3):133-144. doi: 10.1177/0309364620909049. Epub 2020 Mar 18.

  PMID: 32186241 RESULT

Study Officials

• Dobrivoje Stokic, MD, DSc

  Methodist Rehabilitation Center

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 16, 2019
• First Posted: February 4, 2019
• Study Start: December 19, 2013
• Primary Completion: August 12, 2014
• Study Completion: August 12, 2014
• Last Updated: October 8, 2020

Record last verified: 2020-10