Prosthetics: Etiology of Amputation

Question 1

Where does the COG move after an amputation

Answer 1

• up and posterior

Question 2

Prosthetics

Answer 2

the design, construction and attachment of artificial limbs or other systems to assume the function of the missing body part

Question 3

prosthesis

Answer 3

device

Question 4

Prosthetist

Answer 4

• master’s level preparation
• designs, fabricates, fits prosthesis

Question 5

Pt’s w/ amputation incidence

Answer 5

• LE amputations more frequent than UE (PVD/PAD)
• UE is most traumatic
• more common in men than women (men tend to be more risk takers, hold manual labour jobs, and less likely to see a healthcare specialist)
• amputation rates increase with age (steeply)

Question 6

Most common causes of amputation

Answer 6

• Neuropathy/vascular conditions 81.9%
• trauma 16.4%
• cancer 0.9%
• congenital anomalies 0.8%

Question 7

Leading causes of amputations

Answer 7

• health conditions that affect the blood vessels (PVD/PAD)

Question 8

Risk factors for dysvascular disease

Answer 8

• diabetes (increase risk of amputation 10x)
• smoking
• advanced age
• hypertension
• hyperlipidemia

Question 9

Traumatic amputation

Answer 9

• second leading cause of amputation
• most common in young adult group (20-29)
• leading cause: injuries involving machinery, power tools
• incidence decreasing over time due to safety regulations, safer farm and industrial machinery, medical advancement in salvaging limbs with reattachment/revascularization

Question 10

levels of amputation

Answer 10

perfomed at either

• joint disarticulation: names by the joint though which amputation has been made

OR

• transection through long bone
• named by major bone through which amputation has been made

Question 11

LE examples of joint disarticulation amputation

Answer 11

• hip disarticulation
• knee disarticulation
• ankle disarticulation

Question 12

LE examples of transection through long bone

Answer 12

• transpelvic
• transfemoral
• transtibial
• transmetatarsal

Question 13

Diabetes and vascular disease

Answer 13

• prevalence and severity of dysvascularity increases with age and duration of diabetes
• diabetes with dysvascularity: increase risk of non healing ulcer, infection, gangrene

Question 14

Racial and ethnic factors

Answer 14

• certain racial and ethnic groups are at risk for LE amputation
• appears related to increase prevalence of diabetes and PAD

native Americans, African Americans, hispanic Americans

Question 15

30-day mortality rate

Answer 15

• 30-day mortality rate for dysvascular LE amputations is 7-13%

Question 16

How is the 30-day mortality rate for dysvascular LE amputations predicted?

Answer 16

• age >80
• dependent functional status before surgery
• dialysis
• steroid use
• preop sepsis
• impaired cognition
• renal insufficiency

Question 17

5 year mortality rate for different LE amputations

Answer 17

• transtibial 40-80%
• transferal 40-90%
• higher than 5 year mortality rate for breast cancer, colon cancer, and prostate cancer.

Question 18

outcome after dysvascular amputation

Answer 18

• vascular disease usually affects both LE’s
• about 1/2 of persons undergoing diabetes related amputation will have the contralateral amputation within 3-5 years
• emphasize importance of protecting the remaining limb

Question 19

Prevention of amputation

Answer 19

• evidence that preventative care is effective
• interdisciplinary team approach
• smoking reduction programs
• dietary, exercise, pharmaceutical interventions
• foot care

Question 20

Goals of prevention amputation

Answer 20

• control HTN
• control hyperlipidemia
• control hyperglycemia

Question 21

Rehab after amputation: phases

Answer 21

• postop phase: surgery to d/c from acute care
• pre prosthetic phase: discharge from acute care to fitting with permanent prosthesis or decision that patient is not prosthetic candidate
• prosthetic training: duration varies by patient

Question 22

Factors influencing post-amputation rehab success

Answer 22

• age
• cognitive status
• concurrent disease/comorbidity
• level of amputation: energy cost
• muscle strength: hip extension/grip
• single limb stance

Question 23

Why is hip extension and grip strength important for post-amputation success

Answer 23

• hip extension: walking/standing
• grip strength: indicator of health

Question 24

General Principles of amputation surgery

Answer 24

• surgeons want to save as much length as possible
• residual limb is able to tolerate the stress of prosthetic ambulation
• peripheral nerves must be severed
• send out tendrils that form clusters of nerve ends (neuromas)
• if small and embedded in soft tissue they usually do not cause a problem
• surgeon pulls down major nerves firmly, resects them and allows them to retract into soft tissue

Question 25

Muscle mangement in amputations

Answer 25

• when muscle severed it loses distal attachments
• if left loss they will retract, atrophy and scar in place
• muscle management in amputation: myoplasty vs myodesis

Question 26

myoplasty

Answer 26

• attach anterior and posterior compartment muscles to each other over the end of the bone

Question 27

Myodesis

Answer 27

• anchor muscle to bone (rare)

Question 28

Soft tissue management: skin flaps

Answer 28

• usually as broad as distal end of limb
• shaped to allow corners to retract smoothly
  avoid “dog ears”: