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Functional Outcomes in Dysvascular Transfemoral Amputees (CLEG)

This study is ongoing, but not recruiting participants.
Otto Bock Healthcare
Information provided by (Responsible Party):
Arun Jayaraman, Rehabilitation Institute of Chicago Identifier:
First received: February 7, 2012
Last updated: April 12, 2017
Last verified: April 2017
In older adults, poor circulation in the lower extremities leads to serious health complications including limb loss. In addition, individuals with dysvascular disease also suffer from other co-morbidities like diabetes, coronary and cerebrovascular disease. An individual with a transfemoral (TF) amputation is usually fitted with a prosthetic limb to assist with function, including a prosthetic knee and a prosthetic foot. Currently, dysvascular amputees are given a prosthetic knee based on the basic expectation that they will be functionally stable. This consideration does not address higher levels of function like walking at multiple speeds and over uneven ground. Also, dysvascular amputees are not able to counteract their co-morbidities with a more active lifestyle. Walking is less energy efficient; their traditional prostheses may cause early onset of fatigue and induce a fear of falling. Newer microprocessor knees enable patients with transfemoral amputations to walk on different surfaces and at multiple cadences through better control in swing and stance phases of gait. The impact of the functional differences in the prostheses is not clear and requires additional investigation to clarify the choice of the most appropriate functional prosthesis. The purpose of this study is to compare the functional outcomes with the traditional mechanical knee versus the microprocessor knee (C-leg) in transfemoral amputees.

Condition Intervention
Transfemoral Amputation
Unilateral Traumatic Amputation of Leg at or Above Knee
Device: C leg compared to subject's mechanical leg (Otto Bock)

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Outcomes Assessor
Primary Purpose: Treatment
Official Title: Microprocessor Knee Versus Mechanical Knee: Impact on Functional Outcomes in Dysvascular Transfemoral Amputees

Resource links provided by NLM:

Further study details as provided by Rehabilitation Institute of Chicago:

Primary Outcome Measures:
  • Change in community physical activity as measured by GPS [ Time Frame: baseline, 6 months 12 months ]
    We will measure the difference in social mobility (as seen by GPS) between the 2 devices

Secondary Outcome Measures:
  • Change in Functional walking and balance capacity [ Time Frame: every 3 months ]
    Functional capacity will be assessed using step activity, 6 minute walk test, amputee mobility predictor, Community Participation Indicator, Single Leg stance, Timed Up and Go, Berg Balance Score, Four Square step Test, Falls Efficacy Scale and Prosthetic Evaluation Questionnaire at different points of the study

Estimated Enrollment: 40
Study Start Date: August 2011
Estimated Study Completion Date: December 2017
Estimated Primary Completion Date: October 2017 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Microprocessor knee then Mechanical knee Device: C leg compared to subject's mechanical leg (Otto Bock)
comparison of different prosthetic knees
Other Name: Otto Bock
Experimental: Mechanical Knee then Microprocessor knee Device: C leg compared to subject's mechanical leg (Otto Bock)
comparison of different prosthetic knees
Other Name: Otto Bock

Detailed Description:

In older adults, poor circulation in the lower extremities or dysvascular disease can lead to serious health complications. In addition, these individuals also suffer from serious co-morbidities like diabetes and coronary or cerebrovascular disease. Circulatory dysfunction or dysvascular disease is the major cause for amputations in the United States (www.amputee-coalition.orf/fact_sheet/amp_stats_cause.html). Increasing sedentary lifestyles have lead to increased rates of diabetes which has significantly contributed to an increased number of amputations in recent years. The risk of amputation in a diabetic individual is 25 times higher than in the non-diabetic population. The level of amputation that is appropriate for an individual depends on the extent of damage to his/her tissues. Common amputations of the lower extremities in the dysvascular population include the transtibial and transfemoral amputations. The individual having a transtibial or below knee amputation, will be fitted with a prosthetic foot to assist with functional ambulation, while a person with a transfemoral amputation will require both a prosthetic foot and knee for ambulatory purposes. Currently dysvascular amputees are given prostheses based on the goal of returning them to a basic level of function focused primarily on stability. They are considered lower functioning walkers and are expected to use a slow and constant walking speed to ambulate around their homes and are not considered traditional community ambulators. Therefore, they are traditionally given standard mechanical knees which are considered safe, as they provide the ability for only simple single speed house-hold tasks. While this criterion does return the patient to function for basic Activities of Daily Living (ADLs) and walking at a single cadence, it does not empower the patient to counteract the previously existing co-morbidities. Dysvascular amputees tend to be less active predisposing them to a more sedentary lifestyle and exacerbating their risk factors. Their prostheses make them energy inefficient and use more energy for ADLs and functional walking. This causes early onset of fatigue, induces anxiety and fear of falling. Further, they are often depressed, lose motivation and curtail their community interaction. This raises the question if dysvascular amputees are further functionally limited by the prostheses traditionally given to them.

More recently, technology has been used to assist with return to function in the amputee population. Microprocessor (MP) controlled knees are among the technological innovations applied to prostheses to not only return amputees to a basic function, but also with a view to return them to their highest possible function. Over the years, clinical use has shown that traditional knees provide the ability to complete ADLs and basic functions like sit - stand. However, activities like negotiating stairs/steps, walking on uneven ground and self-correction during tripping; functions which reintegrate amputees into unlimited community ambulation and social reintegration require prosthetics which advanced functionality. The Otto Bock C-leg is a MP knee that allows the patient a greater level of control in swing and stance phases of gait. This enables the TF amputee to adjust the requirements of gait during dynamic walking like changing the speed of walking, going up and down stairs and inclines, walking on grass and uneven surfaces and crossing an obstacle. The C-leg has been traditionally given to patients who begin post-amputation rehabilitation at a higher level, but are more expensive than traditionally mechanical knees. In the contrary however, a European study that defined health outcomes in terms of quality-adjusted life year (QALY), indicated that the C-leg showed a QALY gain of €3218 per patient, makes it still financial viable keeping it mind its price tag.. The purpose of this study is to compare the traditional mechanical knee to the microprocessor knee (C-leg) in the dysvascular population. The study will specifically evaluate the potential of microprocessor knees to improve the quality of life in dysvascular transfemoral amputees. This includes identifying if the C-leg can increase the activity level to be classified at a higher level by the Medicare classification from K2 (lower level ambulators) to K3 (more proficient ambulators), along with increasing their social interaction in the community.


Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Males or females with dysvascular transfemoral amputations
  • 6 months or more post prosthetic fitting
  • Homebound or limited community ambulators post amputation
  • Ability to walk > 50m in a 2 min walk test

Exclusion Criteria:

  • Traumatic, cancer or genetic amputation
  • Co-morbidity that completely prevents physical activity
  • Significant skin lesions/ulcers on stump that prevent fitting of prosthesis
  • Cognitive deficits or visual impairments that would impair their ability to give informed consent or to follow simple instructions during experiment
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Please refer to this study by its identifier: NCT01537211

United States, Illinois
Rehabilitation Institute of Chicago, 345 E Superior St
Chicago, Illinois, United States, 60611
Sponsors and Collaborators
Rehabilitation Institute of Chicago
Otto Bock Healthcare
Principal Investigator: Arun Jayaraman, PT PhD Rehabilitation Institute of Chicago
  More Information

Responsible Party: Arun Jayaraman, Director, Rehab Technolgoies and Outcomes Lab, Rehabilitation Institute of Chicago Identifier: NCT01537211     History of Changes
Other Study ID Numbers: STU00042823
Study First Received: February 7, 2012
Last Updated: April 12, 2017

Keywords provided by Rehabilitation Institute of Chicago:
above knee

Additional relevant MeSH terms:
Amputation, Traumatic
Leg Injuries
Wounds and Injuries processed this record on April 26, 2017