Transfemoral Amputation
Conditions
Brief summary
In current clinical prosthetic practice, there is no evidence based method for selecting a microprocessor knee (MPK) joint for a patient with an above the knee amputation. Of individuals with amputation in veteran and service member populations, approximately 35% present with an above the knee amputation. It is well understood in clinical practice that MPKs provide numerous benefits to patients with amputations above the knee including improved gait, safety, comfort, confidence, reduced falls, balance, patient satisfaction and reduced energy expenditure, greater ease in negotiating varying terrains, improvements in multi-tasking and cost effectiveness. Studies that have investigated commercially available MPKs tend to lump all of them together within a single group rather than teasing out individual differences between each knee. Therefore, clinicians are left to rely on their own intuition and past experiences with an MPK when selecting for a patient with an above the knee amputation rather than making their decision based on evidence collected from the specific patient. This may mean that some individuals with an above the knee amputation may not be receiving the best component for them which may delay or inhibit their rehabilitation potential following their amputation.
Interventions
DEVICEMicroprocessor prosthetic knee
Microprocessor prosthetic knees for use in a transfemoral prosthesis
Sponsors
Georgia Institute of Technology
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* A unilateral transfemoral amputation of the lower limb at least six months post fitting of definitive lower extremity prosthesis * Habitual use of a lower extremity prosthesis in daily living activities (based on assessment of a physiatrist and/or prosthetist and patient self-report) * Aged between 18 to 75 years * K3 or K4 level ambulators who can perform all locomotor tasks of interest (based on assessment of a physiatrist and/or prosthetist)
Exclusion criteria
* Individuals with any significant neuromuscular or musculoskeletal disorder or other comorbidity that would interfere with participation (based on assessment of the physiatrist and/or prosthetist and patient self-report) * Individuals who have open wounds on their residual limb * Individuals with known visual impairments that would prevent them from safely operating a prosthesis during over ground walking or ascending stairs (based on assessment of the physiatrist and/or prosthetist and patient self-report) * Individuals with known hearing impairments or who use hearing aids that would prevent them from responding to an auditory instruction (based on assessment of the physiatrist and/or prosthetist and patient self-report) * Individuals who are currently pregnant (based on patient self-report) due to slight risk of falling during experiments
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Ten Meter Walking Test | 1 month | Self selected walking speed over ten meters of walking over ground. |
| Two Minute Walking Test | 1 month | Self selected walking speed over two minutes of walking over ground. |
| Prosthetic Evaluation Questionnaire (PEQ) | 1 month | A patient reported survey on perceptions of a prosthesis. Scores range zero to one hundred with zero being representing a negative patient reported outcome and one hundred representing a positive patient reported outcome. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Physiological Cost Index | 1 month | A clinical measure of energy expenditure. This formula consists of working heart minus resting heart rate divided by speed. |
| Stair Ascent Speed | 1 month | Self selected walking speed during stair ascent. |
| Stair Descent Speed | 1 month | Self selected walking speed while descending stairs. |
| Stance Time Asymmetry Index | 1 month | Stance time asymmetry index measures the percent difference in stance time between the prosthetic and sound side limbs. A value equal to zero is indicative of perfect symmetry. Negative values of ST asymmetry index are indicative of increased time spent on the sound side and positive values are indicative of increased time on the prosthetic side. |
| Ramp Descent Speed | 1 month | Self selected walking speed while descending a 5 degree incline. |
| Steps Per Day | 1 month | Steps per day as measured by StepWatch. |
| Ramp Ascent Speed | 1 month | Self selected walking speed while ascending a 5 degree incline. |
| Narrowing Beam Walking Test | 1 month | A measure of balance via walking down a narrowing beam. |
| Reported Falls | 1 month | Average reported falls per day. |
Countries
United States
Participant flow
Pre-assignment details
Knee condition order was randomized prior to enrollment.
Participants by arm
| Arm | Count |
|---|---|
| Study Microprocessor Prosthetic Knee Randomization to C-Leg 4.0, Rheo Knee and Power Knee | 11 |
| Total | 11 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Withdrawal by Subject | 1 |
Baseline characteristics
| Characteristic | Study Microprocessor Prosthetic Knee |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 1 Participants |
| Age, Categorical Between 18 and 65 years | 10 Participants |
| Age, Continuous | 49.5 years STANDARD_DEVIATION 10.4 |
| AMPnoPro | 38.1 units on a scale STANDARD_DEVIATION 3.9 |
| Clinically Prescribed Prosthetic Knee Otto Bock C-Leg | 7 Participants |
| Clinically Prescribed Prosthetic Knee Otto Bock X3 | 1 Participants |
| Clinically Prescribed Prosthetic Knee Plie | 2 Participants |
| Clinically Prescribed Prosthetic Knee Proteor Quattro | 1 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 11 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Height | 1.75 Meters STANDARD_DEVIATION 0.11 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 8 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 3 Participants |
| Sex: Female, Male Female | 2 Participants |
| Sex: Female, Male Male | 9 Participants |
| Weight | 82.5 Kilograms STANDARD_DEVIATION 16.3 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 10 | 0 / 10 | 0 / 11 |
| other Total, other adverse events | 0 / 10 | 0 / 10 | 0 / 11 |
| serious Total, serious adverse events | 0 / 10 | 0 / 10 | 0 / 11 |
Outcome results
Primary
Prosthetic Evaluation Questionnaire (PEQ)
A patient reported survey on perceptions of a prosthesis. Scores range zero to one hundred with zero being representing a negative patient reported outcome and one hundred representing a positive patient reported outcome.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Prosthetic Evaluation Questionnaire (PEQ) | Power Knee | 69.4 units on a scale | Standard Deviation 8.99 |
| Prosthetic Knee Randomized | Prosthetic Evaluation Questionnaire (PEQ) | C-Leg 4.0 | 83.2 units on a scale | Standard Deviation 10.15 |
| Prosthetic Knee Randomized | Prosthetic Evaluation Questionnaire (PEQ) | Rheo | 78.4 units on a scale | Standard Deviation 11.75 |
Comparison: The Non-parametric Friedman's test was used to compare the survey results between the participants using the Power Knee and the C-Leg 4.0.p-value: 0.006Non-parametric Friedman's test with mult
Comparison: The Non-parametric Friedman's test was used to compare the survey results between the participants using the Power Knee and the Rheo.p-value: 0.236Non-parametric Friedman's test with mult
Comparison: The Non-parametric Friedman's test was used to compare the survey results between the participants using the Rheo and the C-Leg 4.0.p-value: 0.118Non-parametric Friedman's test with mult
Primary
Ten Meter Walking Test
Self selected walking speed over ten meters of walking over ground.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Ten Meter Walking Test | Rheo | 1.1111 Meters per second | Standard Deviation 0.201 |
| Prosthetic Knee Randomized | Ten Meter Walking Test | Power Knee | 0.9963 Meters per second | Standard Deviation 0.2061 |
| Prosthetic Knee Randomized | Ten Meter Walking Test | C-Leg 4.0 | 1.1051 Meters per second | Standard Deviation 0.2081 |
Comparison: An ANOVA was used to compare the Power Knee and the C-Leg 4.0 when used during Ten Meter Walking Test.p-value: 0.126ANOVA
Comparison: An ANOVA was used to compare the Power Knee and the Rheo when used during Ten Meter Walking Test.p-value: 0.015ANOVA
Comparison: An ANOVA was used to compare the Rheo and the C-Leg 4.0 when used during Ten Meter Walking Test.p-value: 0.852ANOVA
Primary
Two Minute Walking Test
Self selected walking speed over two minutes of walking over ground.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Two Minute Walking Test | C-Leg 4.0 | 1.2106 Meters per second | Standard Deviation 0.2025 |
| Prosthetic Knee Randomized | Two Minute Walking Test | Power Knee | 1.073 Meters per second | Standard Deviation 0.2415 |
| Prosthetic Knee Randomized | Two Minute Walking Test | Rheo | 1.1698 Meters per second | Standard Deviation 0.2458 |
Comparison: An ANOVA was used to compare the Power Knee and the C-Leg 4.0 when used during Two Meter Walking Test.p-value: 0.003ANOVA
Comparison: An ANOVA was used to compare the Power Knee and the Rheo when used during Two Meter Walking Test.p-value: 0.027ANOVA
Comparison: An ANOVA was used to compare the Rheo and the C-Leg 4.0 when used during Two Meter Walking Test.p-value: 0.425ANOVA
Secondary
Narrowing Beam Walking Test
A measure of balance via walking down a narrowing beam.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Narrowing Beam Walking Test | Power Knee | 11.3 Feet | Standard Deviation 3.14 |
| Prosthetic Knee Randomized | Narrowing Beam Walking Test | C-Leg 4.0 | 12.6 Feet | Standard Deviation 2.8 |
| Prosthetic Knee Randomized | Narrowing Beam Walking Test | Rheo | 13.5 Feet | Standard Deviation 2.64 |
Comparison: An ANOVA was used to compare the Power Knee, the C-Leg 4.0, and Rheo when used during the Narrowing beam walking test.p-value: 0.082ANOVA
Secondary
Physiological Cost Index
A clinical measure of energy expenditure. This formula consists of working heart minus resting heart rate divided by speed.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Physiological Cost Index | Power Knee | 0.29 Heart beats per meter | Standard Deviation 0.1034 |
| Prosthetic Knee Randomized | Physiological Cost Index | C-Leg 4.0 | 0.25 Heart beats per meter | Standard Deviation 0.0593 |
| Prosthetic Knee Randomized | Physiological Cost Index | Rheo | 0.27 Heart beats per meter | Standard Deviation 0.0984 |
Comparison: An ANOVA was used to compare the Physiological cost index for when the Power Knee, the C-Leg 4.0, and the Rheo were used.p-value: 0.535ANOVA
Secondary
Ramp Ascent Speed
Self selected walking speed while ascending a 5 degree incline.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Ramp Ascent Speed | Power Knee | 0.8929 Meters per second | Standard Deviation 0.1533 |
| Prosthetic Knee Randomized | Ramp Ascent Speed | C-Leg 4.0 | 0.969 Meters per second | Standard Deviation 0.2086 |
| Prosthetic Knee Randomized | Ramp Ascent Speed | Rheo | 0.971 Meters per second | Standard Deviation 0.1754 |
Comparison: An ANOVA was used to compare the Ramp Ascent Speed between the Power Knee and the C-Leg 4.0.p-value: 0.144ANOVA
Comparison: An ANOVA was used to compare the Ramp Ascent Speed between the Power Knee and the Rheo.p-value: 0.024ANOVA
Comparison: An ANOVA was used to compare the Ramp Ascent Speed between the Rheo and the C-Leg 4.0.p-value: 0.949ANOVA
Secondary
Ramp Descent Speed
Self selected walking speed while descending a 5 degree incline.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Ramp Descent Speed | Power Knee | 0.7643 Meters per second | Standard Deviation 0.1675 |
| Prosthetic Knee Randomized | Ramp Descent Speed | C-Leg 4.0 | 0.869 Meters per second | Standard Deviation 0.2282 |
| Prosthetic Knee Randomized | Ramp Descent Speed | Rheo | 0.8584 Meters per second | Standard Deviation 0.2436 |
Comparison: An ANOVA was used to compare the Ramp Descent Speed for the Power Knee, C-Leg 4.0, and the Rheo when used.p-value: 0.051ANOVA
Secondary
Reported Falls
Average reported falls per day.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Reported Falls | Rheo | 0.01429 Falls per day | Standard Deviation 0.04286 |
| Prosthetic Knee Randomized | Reported Falls | Power Knee | 0.06429 Falls per day | Standard Deviation 0.10326 |
| Prosthetic Knee Randomized | Reported Falls | C-Leg 4.0 | 0.04286 Falls per day | Standard Deviation 0.06547 |
Comparison: An ANOVA was used to compare the reported falls when for when the Power Knee, C-Leg 4.0, and the Rheo were used.p-value: 0.943ANOVA
Secondary
Stair Ascent Speed
Self selected walking speed during stair ascent.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Stair Ascent Speed | Power Knee | 50.463 Steps per minute | Standard Deviation 7.9767 |
| Prosthetic Knee Randomized | Stair Ascent Speed | C-Leg 4.0 | 56.336 Steps per minute | Standard Deviation 17.494 |
| Prosthetic Knee Randomized | Stair Ascent Speed | Rheo | 48.336 Steps per minute | Standard Deviation 7.1067 |
Comparison: An ANOVA was used to compare the Stair Ascent Speed for the Power Knee, C-Leg 4.0, and the Rheo when used.p-value: 0.229ANOVA
Secondary
Stair Descent Speed
Self selected walking speed while descending stairs.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Stair Descent Speed | Power Knee | 92.65 Steps per minute | Standard Deviation 25.67 |
| Prosthetic Knee Randomized | Stair Descent Speed | C-Leg 4.0 | 93.997 Steps per minute | Standard Deviation 27.183 |
| Prosthetic Knee Randomized | Stair Descent Speed | Rheo | 88.3 Steps per minute | Standard Deviation 21.261 |
Comparison: An ANOVA was used to compare the Stair Descent Speed for the Power Knee, C-Leg 4.0, and the Rheo when used.p-value: 0.528ANOVA
Secondary
Stance Time Asymmetry Index
Stance time asymmetry index measures the percent difference in stance time between the prosthetic and sound side limbs. A value equal to zero is indicative of perfect symmetry. Negative values of ST asymmetry index are indicative of increased time spent on the sound side and positive values are indicative of increased time on the prosthetic side.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Stance Time Asymmetry Index | Power Knee | -10.15 percentage of stance time | Standard Deviation 3.68 |
| Prosthetic Knee Randomized | Stance Time Asymmetry Index | C-Leg 4.0 | -10.95 percentage of stance time | Standard Deviation 9.98 |
| Prosthetic Knee Randomized | Stance Time Asymmetry Index | Rheo | -7.03 percentage of stance time | Standard Deviation 8.13 |
Comparison: An ANOVA was used to compare the Power Knee, the C-Leg 4.0, and the Rheo when used during Stance Time Asymmetry Index test.p-value: 0.687ANOVA
Secondary
Steps Per Day
Steps per day as measured by StepWatch.
Time frame: 1 month
Population: 1 participant did not complete any of the conditions due to self withdrawal after consenting.~No data obtained from two participants due to experimental error.~Each participant wore all three knees during this trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Prosthetic Knee Randomized | Steps Per Day | Power Knee | 2620.1 Steps per day | Standard Deviation 705.5 |
| Prosthetic Knee Randomized | Steps Per Day | C-Leg 4.0 | 2762.6 Steps per day | Standard Deviation 969.2 |
| Prosthetic Knee Randomized | Steps Per Day | Rheo | 2462.6 Steps per day | Standard Deviation 1030.2 |
Comparison: An ANOVA was used to compare the Steps per Day for the Power Knee, C-Leg 4.0, and the Rheo when used.p-value: 0.367ANOVA