C-Leg 3 and C-Leg 4 Study in Transfemoral Amputees

• Sponsor: Otto Bock Healthcare Products GmbH (Industry)
• Overall Status: Completed
• CT.gov ID: NCT02765035
• Collaborator: (none)
• Enrollment: 18
• Locations: 2
• Arms: 2
• Duration (Months): 25.9
• Patients Per Site: 9
• Patients Per Site Per Month: 0.3

Study Details

Study Description

Brief Summary

The aim of this post-market study is to confirm that the microprocessor controlled prosthetic knee components (C-Leg 3 and C-Leg 4) in comparison to mechanical knee joints can bring additional benefit to the users primarily on level walking and secondarily in safety, stair and hill mobility, activities of daily living, satisfaction and preference.

Condition or Disease	Intervention/Treatment	Phase
Lower Limb Amputation Above Knee (Injury)	Device: C-Leg 4; Device: C-Leg 3	N/A

Detailed Description

During the last two decades many microprocessor controlled knee joints (MPK) appeared on the market.The newly developed C-Leg 4 aims to provide improved standing function while in the same time offering technology of knee´s previous version (C-Leg 3). Since added functional benefit of a knee joint cannot be anticipated just due to the fact that the knee is controlled by the microprocessor, the aim of this post-market study is to evaluate the safety, functional mobility and satisfaction of the microprocessor controlled prosthetic knee components C-Leg 3 and C-Leg 4 in comparison to mechanical knee joints. Additional goal is to improve the methodological quality of research conducted in the field.

Study Design

• Study Type: Interventional
• Actual Enrollment: 18 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Masking: Double (Participant, Outcomes Assessor)
• Primary Purpose: Treatment
• Official Title: A Randomized, Blinded, Cross-over Trial to Evaluate the Safety, Functional Mobility and Satisfaction of the Microprocessor Controlled Prosthetic Knee Component C-Leg 4 in Transfemoral Amputees
• Study Start Date: Apr 1, 2016
• Actual Primary Completion Date: May 30, 2018
• Actual Study Completion Date: May 30, 2018

Arms and Interventions

Arm	Intervention/Treatment
Experimental: C-Leg 3, then C-Leg 4 Participants are first fitted with a C-Leg 3, receive physical therapy, acclimate for 90 days and are then assessed in the clinic. They then receive a C-Leg 4, receive additional physical therapy and acclimate for 30 days after which they are again assessed in the clinic.	Device: C-Leg 4; Microprocessor Controlled Knee; Device: C-Leg 3; Microprocessor Controlled Knee
Experimental: C-Leg 4, then C-Leg 3 Participants are first fitted with a C-Leg 4, receive physical therapy, acclimate for 90 days and are then assessed in the clinic. They then receive a C-Leg 3, receive additional physical therapy and acclimate for 30 days after which they are again assessed in the clinic.	Device: C-Leg 4; Microprocessor Controlled Knee; Device: C-Leg 3; Microprocessor Controlled Knee

Outcome Measures

Primary Outcome Measures

1. Change in 6 Minute Gait Test [Baseline and after acclimation period (30-90 days after fitting)]

   A measure of walking endurance, the distance walked in meters after 6 minutes.

Secondary Outcome Measures

1. Change in 10 Meter Gait Test [Baseline and after acclimation period (30-90 days after fitting)]

   Average gait speed over middle 6 meters of a 10-meter course at both self-selected and fastest safe walking speeds

2. Change in Stairs Assessment Index (SAI) [Baseline and after acclimation period (30-90 days after fitting)]

   Participants are scored on a 14-level scale for independence, technique and step length for ascending and descending a 12-step ADA-compliant stairwell. The maximum score is 13 and the minimum 0. Higher scores indicate greater independence. Time to descend stairs was also recorded.

3. Change in Hill Assessment Index (HAI) [Baseline and after acclimation period (30-90 days after fitting)]

   Participants are scored on a 12-level scale for independence, technique and step length for descending a 5m, 5-degree downgrade hill at self selected speed. The maximum score is 11 and the minimum 0. Higher scores indicate greater independence. Time to descend the hill was also recorded.

4. Change in Four Step Square Test (FSST) [Baseline and after acclimation period (30-90 days after fitting)]

   Time to complete a stepping sequence through 4 squares as quickly as possible. The test involves stepping forward, backward and sideways to the left and right while face the same direction.

5. Change in Activities-specific Balance Confidence (ABC) Scale [Baseline and after acclimation period (30-90 days after fitting)]

   Assessment of patient-perceived balance confidence for 16 activities of daily living. For each activity, subjects rate their level of confidence in doing the activity without losing their balance or becoming unsteady on a scale from 0% to 100%, with 100% being the highest level of confidence. The total score for the ABC scale is an average of all activity scores.

6. Change in Prosthetic Limb Users Survey of Mobility (PLUS-M) [Baseline and after acclimation period (30-90 days after fitting)]

   The PLUS-M 12-item short form is a valid and reliable self-reported measure for the mobility of adults with lower limb amputations. PLUS-M asks about the patient's ability to perform simple and complex tasks. Higher PLUS-M scores correspond with greater mobility. T-scores range from 21.8 to 71.4. A T-score has a mean of 50 and a standard deviation (SD) of 10. A PLUS-M T-score of 50 represents the mean mobility reported by the development sample (i.e., people with unilateral amputation).

7. Change in Amputee Body Image Scale (ABIS) [Baseline and after acclimation period (30-90 days after fitting)]

   The ABIS assesses how an amputee perceives and feels about his or her body experience. The scale addresses several different domains, including: 1) body appearance; 2) body function; 3effective distress; and 4) behavioral avoidance in social situations. The scale produces scores that range from 1 to 100, with low scores indicating the relative absence of a body image concern and higher scores indicating the presence of a more serious body-image concern.

8. Change in Number of Stumbles and Falls [Baseline and after acclimation period (30-90 days after fitting)]

   Stumbles and falls in the previous 30 days for each studied device based on records in a subject log book. At baseline, users were asked to recall the number of stumbles and falls in the previous 30 days.

9. Preference of the Knee (Percentage of Subjects That Preferred Each Studied Knee) [At 3rd study visit after having been fitted and acclimatized to each of the study devices]

   The user´s knee preference is assessed with the question: "Which prosthesis do you prefer?"

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years and Older
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Inclusion Criteria:

• Person is >18 years old.

• Person is a unilateral transfemoral or knee-disarticulation amputee with stabilized residual limb.

• Person is a K2, K3 or K4 ambulator based on Medicare Functional Classification Level (MFCL).

• Person is currently fitted with a prosthesis using a non-microprocessor controlled prosthetic knee for at least 6 months.

• Person was never fitted with microprocessor controlled prosthetic knee joint.

• Person is willing and able to independently provide informed consent.

• Person is willing to comply with study procedures.

• Person wears prosthesis daily and ≥ 8 hours/day.

• Person is walking on average 1km/day.

• Person is walking not slower than 3km/h (~0.8m/s) (based on 10m walk test conducted during recruiting).

• Person is walking on level ground in a step over step manner.

Exclusion Criteria:

• Person is under 18 years of age.

• Person who weighs more than 136kg.

• Person who weighs less than 50kg.

• Person who is pregnant.

• Person has a history of chronic skin breakdown on the residual limb.

• Person has conditions that would prevent participation and pose increased risk (e.g. unstable cardiovascular conditions that preclude physical activity such as walking).

• Person falls ≥ once a week due to the reasons that could not be corrected by the new prosthesis (for ex. problems with vestibular system).

• Person is using under arm axillary crutches or walker.

• Person in an emergency, life threatening situation.

• Person is unwilling/unable to follow instructions.

• Person who is not available to follow the entire study protocol.

• Person who is participating in another study or intends to participate in another study during this study duration.

• Person who cannot personally provide their consent.

• Person who is not wearing prosthesis 8hours/day on average.

• Person who has a score on 10m walk test less than 3km/h (~0.8m/s) (based on 10m walk test conducted during recruiting).

• Person who walks on average less than 1km per day.

• Person who is not able to walk on level ground in a step over step manner.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Orthopedic Rehabilitation Center SKA Zicksee	Sankt Andrä Am Zicksee	Burgenland	Austria	7161
2	University Leuven	Pellenberg		Belgium	3212

Sponsors and Collaborators

• Otto Bock Healthcare Products GmbH

Investigators

• Principal Investigator: Stephan Domayer, Prim.Dr., Orthopedic Rehabilitation Center

Study Documents (Full-Text)

• Study Protocol and Statistical Analysis Plan - Dec 15, 2015

More Information

Publications

None provided.

• Responsible Party: Otto Bock Healthcare Products GmbH
• ClinicalTrials.gov Identifier: NCT02765035
• Other Study ID Numbers: PD-PS00120010A-001
• First Posted: May 6, 2016
• Last Update Posted: Oct 14, 2021
• Last Verified: Sep 1, 2021

• Individual Participant Data (IPD) Sharing Statement: Yes
• Plan to Share IPD: Yes

Study Results

Participant Flow

Pre-assignment Detail	5 subjects were excluded from the study prior to randomization: 3 subjects had adverse events, 1 subject could not be fitted with the intervention device due to anthropomorphic characteristics, and 1 subject withdrew due to a change in work situation.

Arm/Group Title	C-Leg 3, Then C-Leg 4	C-Leg 4, Then C-Leg 3
Arm/Group Description	The participants were first fitted with C-Leg 3 and allowed to accommodate for up to 90 days after which they were assessed. Then they crossed over to be fitted with the C-Leg 4 and allowed to accommodate for 30 days after which they were assessed.	The participants were first fitted with C-Leg 4 and allowed to accommodate for up to 90 days after which they were assessed. Then they crossed over to be fitted with the C-Leg 3 and allowed to accommodate for 30 days after which they were assessed.
Period Title: First Intervention (90 Days)
STARTED	5	8
COMPLETED	4	7
NOT COMPLETED	1	1
Period Title: First Intervention (90 Days)
STARTED	4	7
COMPLETED	2	5
NOT COMPLETED	2	2

Baseline Characteristics

Arm/Group Title	C-Leg 3, Then C-Leg 4	C-Leg 4, Then C-Leg 3	Total
Arm/Group Description	C-Leg 4: Microprocessor Controlled Knee C-Leg 3: Microprocessor Controlled Knee	C-Leg 4: Microprocessor Controlled Knee C-Leg 3: Microprocessor Controlled Knee	Total of all reporting groups
Overall Participants	5	8	13
Age (years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [years]	64.0 (4.95)	58.5 (12.2)	60.6 (10.2)
Sex: Female, Male (Count of Participants)
Female	1 20%	3 37.5%	4 30.8%
Male	4 80%	5 62.5%	9 69.2%
Race and Ethnicity Not Collected (Count of Participants)
Count of Participants [Participants]	0 0%
Region of Enrollment (participants) [Number]
Austria	2 40%	2 25%	5 38.5%
Belgium	3 60%	6 75%	8 61.5%
Height (cm) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [cm]	177.4 (7.54)	172.13 (9.40)	174.15 (8.81)
Weight (kg) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [kg]	74.4 (12.4)	73.9 (14.4)	74.1 (13.1)
Time since amputation (years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [years]	21.8 (23.6)	23.0 (14.9)	22.54 (17.74)
Amputation side (Count of Participants)
left	1 20%	3 37.5%	4 30.8%
right	4 80%	5 62.5%	9 69.2%
Amputation type (Count of Participants)
Transfemoral	0 0%	4 50%	4 30.8%
Knee disarticulation	5 100%	4 50%	9 69.2%
Medicare Functional Classification Level (MFCL) (Count of Participants)
2	1 20%	1 12.5%	2 15.4%
3	4 80%	6 75%	10 76.9%
4	0 0%	1 12.5%	1 7.7%
Current knee prosthesis (NMPK) (Count of Participants)
3R106	1 20%	3 37.5%	4 30.8%
3R15	0 0%	1 12.5%	1 7.7%
3R60	2 40%	1 12.5%	3 23.1%
3R80	2 40%	1 12.5%	3 23.1%
Polycentric	0 0%	1 12.5%	1 7.7%
Multiaxial	0 0%	1 12.5%	1 7.7%
Amputation cause (Count of Participants)
cancer	1 20%	5 62.5%	6 46.2%
infection	1 20%	1 12.5%	2 15.4%
trauma	1 20%	1 12.5%	2 15.4%
vascular disease	2 40%	1 12.5%	3 23.1%
Hours of wearing prosthesis per day (hours) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [hours]	12.4 (2.6)	12.4 (2.7)	12.4 (2.6)
Distance covered per day (km) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [km]	3.6 (2.1)	3.25 (1.5)	3.38 (1.7)

Outcome Measures

1. Primary Outcome

Title	Change in 6 Minute Gait Test
Description	A measure of walking endurance, the distance walked in meters after 6 minutes.
Time Frame	Baseline and after acclimation period (30-90 days after fitting)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	C-Leg 3	C-Leg 4
Arm/Group Description	The participants wearing a C-Leg 3 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)	The participants wearing a C-Leg 4 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)
Measure Participants	7	7
Baseline	380.4 (69.66)	380.4 (69.66)
Change from Baseline after accommodation	35.9 (20.26)	26.7 (33.87)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	C-Leg 3
	Comments	C-Leg 3 vs. NMPK (Baseline)
	Type of Statistical Test	Superiority
	Comments
Statistical Test of Hypothesis	p-Value	0.01
	Comments
	Method	t-test, 1 sided
	Comments

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	C-Leg 4
	Comments	C-Leg 4 vs. NMPK (Baseline)
	Type of Statistical Test	Superiority
	Comments
Statistical Test of Hypothesis	p-Value	0.04
	Comments
	Method	t-test, 1 sided
	Comments

2. Secondary Outcome

Title	Change in 10 Meter Gait Test
Description	Average gait speed over middle 6 meters of a 10-meter course at both self-selected and fastest safe walking speeds
Time Frame	Baseline and after acclimation period (30-90 days after fitting)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	C-Leg 3	C-Leg 4
Arm/Group Description	The participants wearing a C-Leg 3 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)	The participants wearing a C-Leg 4 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)
Measure Participants	7	7
SSWS at Baseline	1.11 (0.168)	1.11 (0.168)
SSWS after acclimation	0.00 (0.06)	-0.25 (0.14)
FWS at Baseline	1.36 (0.262)	1.36 (0.262)
FWS after acclimation	0.21 (0.15)	-0.03 (0.08)

3. Secondary Outcome

Title	Change in Stairs Assessment Index (SAI)
Description	Participants are scored on a 14-level scale for independence, technique and step length for ascending and descending a 12-step ADA-compliant stairwell. The maximum score is 13 and the minimum 0. Higher scores indicate greater independence. Time to descend stairs was also recorded.
Time Frame	Baseline and after acclimation period (30-90 days after fitting)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	C-Leg 3	C-Leg 4
Arm/Group Description	The participants wearing a C-Leg 3 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)	The participants wearing a C-Leg 4 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)
Measure Participants	7	7
Baseline SAI (Ascent)	5 (2.6)	5 (2.6)
Change in SAI (Ascent) after fitting and acclimation	-0.6 (1.5)	0.0 (0.0)
Baseline SAI (Descent)	4 (1.6)	4 (1.6)
Change in SAI (Descent) after fitting and acclimation	5.9 (3.2)	5.7 (2.9)
Baseline time to descent stairs	12.7 (3.95)	12.7 (3.95)
Change in time to descent stairs after fitting and acclimation	-2.1 (1.7)	-3.1 (2.0)

4. Secondary Outcome

Title	Change in Hill Assessment Index (HAI)
Description	Participants are scored on a 12-level scale for independence, technique and step length for descending a 5m, 5-degree downgrade hill at self selected speed. The maximum score is 11 and the minimum 0. Higher scores indicate greater independence. Time to descend the hill was also recorded.
Time Frame	Baseline and after acclimation period (30-90 days after fitting)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	C-Leg 3	C-Leg 4
Arm/Group Description	The participants wearing a C-Leg 3 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)	The participants wearing a C-Leg 4 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)
Measure Participants	7	7
Baseline HAI (Ascent)	8.4 (2.5)	8.4 (2.5)
Change in HAI (Ascent) after fitting and acclimation	1.9 (2.0)	1.1 (1.3)
Baseline HAI (Descent)	7.9 (2.8)	7.9 (2.8)
Change in HAI (Descent) after fitting and acclimation	1.9 (2.0)	0.9 (2.7)
Baseline Descent Time	6.6 (2.5)	6.6 (2.5)
Change in Descent Time after fitting and acclimation	-0.9 (1.3)	-0.4 (1.4)

5. Secondary Outcome

Title	Change in Four Step Square Test (FSST)
Description	Time to complete a stepping sequence through 4 squares as quickly as possible. The test involves stepping forward, backward and sideways to the left and right while face the same direction.
Time Frame	Baseline and after acclimation period (30-90 days after fitting)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	C-Leg 3	C-Leg 4
Arm/Group Description	The participants wearing a C-Leg 3 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)	The participants wearing a C-Leg 4 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)
Measure Participants	7	7
Baseline FSST	13.5 (3.92)	13.5 (3.92)
FSST after fitting and acclimation	-2.6 (1.18)	-2.4 (1.77)

6. Secondary Outcome

Title	Change in Activities-specific Balance Confidence (ABC) Scale
Description	Assessment of patient-perceived balance confidence for 16 activities of daily living. For each activity, subjects rate their level of confidence in doing the activity without losing their balance or becoming unsteady on a scale from 0% to 100%, with 100% being the highest level of confidence. The total score for the ABC scale is an average of all activity scores.
Time Frame	Baseline and after acclimation period (30-90 days after fitting)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	C-Leg 3	C-Leg 4
Arm/Group Description	The participants wearing a C-Leg 3 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)	The participants wearing a C-Leg 4 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)
Measure Participants	7	7
Baseline ABC	72.4 (9.73)	72.4 (9.73)
Change in ABC after fitting and acclimation	1.4 (7.83)	2.7 (8.75)

7. Secondary Outcome

Title	Change in Prosthetic Limb Users Survey of Mobility (PLUS-M)
Description	The PLUS-M 12-item short form is a valid and reliable self-reported measure for the mobility of adults with lower limb amputations. PLUS-M asks about the patient's ability to perform simple and complex tasks. Higher PLUS-M scores correspond with greater mobility. T-scores range from 21.8 to 71.4. A T-score has a mean of 50 and a standard deviation (SD) of 10. A PLUS-M T-score of 50 represents the mean mobility reported by the development sample (i.e., people with unilateral amputation).
Time Frame	Baseline and after acclimation period (30-90 days after fitting)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	C-Leg 3	C-Leg 4
Arm/Group Description	The participants wearing a C-Leg 3 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)	The participants wearing a C-Leg 4 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)
Measure Participants	7	7
Baseline PLUS-M T-Score	50.0 (6.64)	50 (6.64)
Change in PLUS T-Score after fitting and acclimation	0.6 (3.3)	0.8 (3.27)

8. Secondary Outcome

Title	Change in Amputee Body Image Scale (ABIS)
Description	The ABIS assesses how an amputee perceives and feels about his or her body experience. The scale addresses several different domains, including: 1) body appearance; 2) body function; 3effective distress; and 4) behavioral avoidance in social situations. The scale produces scores that range from 1 to 100, with low scores indicating the relative absence of a body image concern and higher scores indicating the presence of a more serious body-image concern.
Time Frame	Baseline and after acclimation period (30-90 days after fitting)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	C-Leg 3	C-Leg 4
Arm/Group Description	The participants wearing a C-Leg 3 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)	The participants wearing a C-Leg 4 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)
Measure Participants	7	7
Baseline ABIS	55.1 (13.01)	55.1 (13.01)
Change in ABIS after fitting and acclimation	1.9 (7.34)	-0.4 (6.97)

9. Secondary Outcome

Title	Change in Number of Stumbles and Falls
Description	Stumbles and falls in the previous 30 days for each studied device based on records in a subject log book. At baseline, users were asked to recall the number of stumbles and falls in the previous 30 days.
Time Frame	Baseline and after acclimation period (30-90 days after fitting)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	C-Leg 3	C-Leg 4
Arm/Group Description	The participants wearing a C-Leg 3 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)	The participants wearing a C-Leg 4 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)
Measure Participants	7	7
Baseline number of stumbles	3.3 (4.07)	3.3 (4.07)
Change in number of stumbles after fitting and acclimation	-0.3 (2.56)	-0.3 (2.29)
Baseline number of falls	1.0 (1.53)	1.0 (1.53)
Change in number of falls after fitting and acclimation	-0.6 (1.62)	-0.1 (1.77)

10. Secondary Outcome

Title	Preference of the Knee (Percentage of Subjects That Preferred Each Studied Knee)
Description	The user´s knee preference is assessed with the question: "Which prosthesis do you prefer?"
Time Frame	At 3rd study visit after having been fitted and acclimatized to each of the study devices

Outcome Measure Data

Analysis Population Description

All subjects with preference data that completed the study were included in the analysis.

Arm/Group Title	All Subjects
Arm/Group Description	All subjects were ask which knee they preferred after having been fitted and acclimatized to each (C-Leg 3, C-Leg 4 and the NMPK)
Measure Participants	11
Number preferring the C-Leg 4	7 140%
Number preferring the C-Leg 3	3 60%
Number preferring the NMPK	1 20%

Adverse Events

Time Frame	36-40 weeks
Arm/Group Title	C-Leg 3		C-Leg 4
Arm/Group Description	The participants wearing a C-Leg 3 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)		The participants wearing a C-Leg 4 either in the first fitting (after max 90 days of acclimation) or the second fitting (after 30 days acclimation)
All Cause Mortality
	C-Leg 3		C-Leg 4
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/13 (0%)		0/13 (0%)
Serious Adverse Events
	C-Leg 3		C-Leg 4
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/13 (0%)		0/13 (0%)
Other (Not Including Serious) Adverse Events
	C-Leg 3		C-Leg 4
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	3/13 (23.1%)		3/13 (23.1%)
Musculoskeletal and connective tissue disorders
Foot pain	0/13 (0%)	0	1/13 (7.7%)	1
Hip pain	0/13 (0%)	0	1/13 (7.7%)	1
Knee pain	0/13 (0%)	0	1/13 (7.7%)	1
Residual limb pain	1/13 (7.7%)	1	0/13 (0%)	0
Respiratory, thoracic and mediastinal disorders
Pneumonia	1/13 (7.7%)	1	0/13 (0%)	0
Skin and subcutaneous tissue disorders
Dermatitis	1/13 (7.7%)	1	0/13 (0%)	0

Limitations/Caveats

From 11 subjects that participated in the study, only 7 followed protocol. From post-hoc power analysis, 22 subjects would be required for 80% power to detect a difference of 35.9m (standard deviation = 30.3m) in the 6MWT. Patients were aware that a walking speed of greater than 0.8 m/s was a prerequisite for study participation, which could have lead to bias (elevated baseline measurement) and explain the small change in observed walking speed with C-Leg 3 and C-Leg 4 compared to baseline.

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

The only disclosure restriction on the PI is that the sponsor can review results communications prior to public release and can embargo communications regarding trial results for a period that is less than or equal to 60 days. The sponsor cannot require changes to the communication and cannot extend the embargo.