Lower Extremity Amputation and Prosthetics

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Lower Extremity Amputation and Prosthetics

• Understanding, Evaluation and Challenges

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Prosthetics Vs. Orthotics

• Prosthesis An artificial device used to replace
  a missing body part, such as a limb, eye, or
  heart valve.
• Orthosis An application or apparatus used to
  support, align, prevent, or correct deformities
  or to improve existing function of movable parts
  of the body.

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Amputation rates increase with

• chronic disease, i.e. complications of diabetes,
  and peripheral vascular diseases,
• being male, traumatic amputations i.e. automobile
  accidents, freezing, burns, farm machinery and
  power tool accidents,
• increasing age
• being a member of a racial or ethnic minority

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Rates of Causes for Amputation

• 70 of amputations are performed for vascular
  disease including diabetic complications,
  arteriosclerosis and thromboembolism,
• 22 due to traumatic injuries and infection
• 4 result from malignancies
• 4 due to congenital deformities

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Lower Extremity Amputation Levels

• Hemipelvectomy and Hip Disarticulation
  amputation of the entire leg including lateral
  portion of pelvis being the ilium, ischum, or
  pubis of same side. Usually done in cases of
  malignant tumors, extensive gangrene, infection
  and trauma
• Disarticulation a separation at the joints, hip
  or knee
• Rotationplasty NEJM -- Rotationplasty for
  Ewing's Sarcoma of the Distal Femur -- Data
  Supplement -

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Rotationplasty
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Transfemoral Amputation Levels

• Short large weight-bearing surface if done at
  level of lesser trochanter, retains femoral head,
  and greater trochanter resulting in an improved
  prosthetic fit. Declined due to improved surgical
  techniques and assessment of vascular function.

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Transfemoral Amputation Levels

• Medium At least 410 cm above lower end of femur
  to allow room for prosthetic knee.
• Knee disarticulation Retains thigh muscles
  giving good muscular balance, growth potential is
  maintained, provides good weight bearing, results
  in difficulty of swing phase control in walking,
  cosmetic asymmetry due to a prosthetic knee that
  extends below the other.

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Transtibial Amputation Levels

• Very Short Usually results from trauma, not an
  elective procedure, very small moment arm,
  retains knee.
• Standard Elective amputation, provides a well
  padded and effective biomechanical lever arm, at
  lease 8 cm of tibia is required.
• Long Not advised due to poor blood supply in
  distal leg.

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Transtibial Amputation Levels

• Syme Named for James Syme, a scottish physician
  mid 1800s, Ankle disarticulation, residual limb
  with good function due to long lever arm to
  control prosthesis, ideally suited for weigh
  bearing and can last life of patient, can walk
  without prosthesis, disadvantages of chronic
  nerve damage to posterior tibial nerve.

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Transmetatarsal Amputation

• Approximately 10,000 performed in US with a 30
  failure rate, attributed to the combination of
  substantial loss of weight bearing area and
  reduced length of lever arm to generate a
  plantarflexor movement. Limited to patients with
  good anterior tibial pulse and blood flow,
  usually performed due to trauma, infection,
  frostbite, diabetes, arteriosclerosis localized
  to the phalanges.

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Patient Challenges

• Psychosocial Body image, self-esteem, struggle
  with change in appearance
• Adults Livelihood, functional capacity,
• interpersonal relationships
• Young Identity, sexuality and social
  acceptance
• Most difficult transition are those individuals
  that are young adults, not married, history of
  addiction

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Patient Challenges

• Financial Concerns Cost of prosthetics Depends
  on degree of disability
• activity of wearer, more than one prosthetic
  needed
• types of components and materials used, metals,
  hydraulic or pneumatic pistons timed for cadence,
  microprocessors adjust pistons for a broad range
  of cadence, composite material, surgical
  silicone, sleeves
• All customized and fitted for the individual
  to provide best fit
• Surfaces that activities are performed effect
  dynamics of prosthetic

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Patient Challenges

• Phantom Limb Pain and Sensation
• Pain perception of pain in the absent
  extremity
• Sensation perception of the absent
  limb