Comparative Effectiveness Between Microprocessor Knees and Non-Microprocessor Knees

Not Applicable

Completed

Interventions: Device: Microprocessor Knee (MPK)
Device: Non-Microprocessor Knee (NMPK)

Brief Summary: This study will assess if the functional performance and musculoskeletal outcome of transfemoral amputees are improved after receiving a Microprocessor Knee (MPK) compared to a Non-Microprocessor Knees (NMPK).

Detailed Description: The study design is a reversal design whereby only the prosthetic knee joint will be changed. Each subject will be tested using their current NMPK, fit and tested with a MPK, and then tested again with their NMPK. MPK prostheses from all manufacturers will be considered appropriate for testing. Each MPK to be used in this study is FDA approved. The foot will be in the L5981 class, e.g. flex foot or equivalent. The same socket, suspension, and foot will be used throughout the study in order to eliminate these confounding variables. All prosthesis fittings will be performed by the subject's own certified prosthetist according to manufacturers' fitting guidelines.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Arm && Interventions

Group	Intervention	Description
Prosthetic knee joints	Microprocessor Knee (MPK)	Each subject will be tested using their current Non-Microprocessor Knee (NMPK) , fit and tested with a Microprocessor Knee (MPK), and then tested again with their NMPK, e.g. A-B-A design.
Prosthetic knee joints	Non-Microprocessor Knee (NMPK)	Each subject will be tested using their current Non-Microprocessor Knee (NMPK) , fit and tested with a Microprocessor Knee (MPK), and then tested again with their NMPK, e.g. A-B-A design.

Primary Outcome Measures

Name	Time	Method
Daily Activity Measured With Triaxial Accelerometers	Baseline (tested on subjects' current NMPK), 10 weeks (after 10 weeks acclimation time to the study MPK) , 4 weeks (subjects placed back on NMPK and tested after 4 weeks re-acclimation time)	Measurements will be obtained three times using activity monitors attached to waist, and bilaterally to the ankle and thigh for a period of 4 consecutive days, including 2 weekdays and 2 weekend days. Primary outcome will be the difference in activity level between the NMPK and MPK measurements.
Falls as Assessed by the Prosthesis Evaluation Questionnaire Addendum (PEQ-A)	Baseline (tested on subjects' current NMPK), 10 weeks (after 10 weeks acclimation time to the study MPK) , 4 weeks (subjects placed back on NMPK and tested after 4 weeks re-acclimation time)	The Prosthesis Evaluation Questionnaire (PEQ) addendum (PEQ-A) is a self-administered questionnaire to quantify balance confidence, concentration, stumbles, and falls. The outcome will be difference in falls per month between the Non-Microprocessor Knee (NPMK) and MPK measurements. The number of falls was recorded as the sum of items #5 and #7 in the PEQ-A.

Secondary Outcome Measures

Name	Time	Method
Patient Satisfaction as Assessed by the Prosthesis Evaluation Questionnaire (PEQ)	Baseline (tested on subjects' current NMPK), 10 weeks (after 10 weeks acclimation time to the study MPK) , 4 weeks (subjects placed back on NMPK and tested after 4 weeks re-acclimation time)	The condition-specific Prosthesis Evaluation Questionnaire (PEQ) was used to quantify patient satisfaction with each prosthesis. The outcome was a difference in PEQ scores between the NPMK and MPK measurements. The PEQ is a self-administered questionnaire composed of nine validated scales (ambulation, appearance, frustration, perceived response, residual limb health, social burden, sounds, utility, well being). Scores range from 0 to 100 for each sub-scale. Higher scores indicated a higher functioning prosthesis/quality of life.