Functional Outcomes in Dysvascular Transfemoral Amputees
Condition: Transfemoral Amputation; Unilateral Traumatic Amputation of Leg at or Above Knee
MeSH terms: Amputation, Traumatic
Study type: Interventional

Summary: 
      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.
    

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.
    

Intervention name(s): C leg compared to subject's mechanical leg (Otto Bock); C leg compared to subject's mechanical leg (Otto Bock)
Intervention type(s): Device; Device
Intervention description(s): comparison of different prosthetic knees; comparison of different prosthetic knees
Other intervention name(s): Otto Bock; Otto Bock
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Dysvascular; amputation; above knee; ambulation