Prosthetics: Etiology of Amputation Flashcards
Where does the COG move after an amputation
- up and posterior
Prosthetics
the design, construction and attachment of artificial limbs or other systems to assume the function of the missing body part
prosthesis
device
Prosthetist
- master’s level preparation
- designs, fabricates, fits prosthesis
Pt’s w/ amputation incidence
- 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)
Most common causes of amputation
- Neuropathy/vascular conditions 81.9%
- trauma 16.4%
- cancer 0.9%
- congenital anomalies 0.8%
Leading causes of amputations
- health conditions that affect the blood vessels (PVD/PAD)
Risk factors for dysvascular disease
- diabetes (increase risk of amputation 10x)
- smoking
- advanced age
- hypertension
- hyperlipidemia
Traumatic amputation
- 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
levels of amputation
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
LE examples of joint disarticulation amputation
- hip disarticulation
- knee disarticulation
- ankle disarticulation
LE examples of transection through long bone
- transpelvic
- transfemoral
- transtibial
- transmetatarsal
Diabetes and vascular disease
- prevalence and severity of dysvascularity increases with age and duration of diabetes
- diabetes with dysvascularity: increase risk of non healing ulcer, infection, gangrene
Racial and ethnic factors
- 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
30-day mortality rate
- 30-day mortality rate for dysvascular LE amputations is 7-13%
How is the 30-day mortality rate for dysvascular LE amputations predicted?
- age >80
- dependent functional status before surgery
- dialysis
- steroid use
- preop sepsis
- impaired cognition
- renal insufficiency
5 year mortality rate for different LE amputations
- transtibial 40-80%
- transferal 40-90%
- higher than 5 year mortality rate for breast cancer, colon cancer, and prostate cancer.
outcome after dysvascular amputation
- 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
Prevention of amputation
- evidence that preventative care is effective
- interdisciplinary team approach
- smoking reduction programs
- dietary, exercise, pharmaceutical interventions
- foot care
Goals of prevention amputation
- control HTN
- control hyperlipidemia
- control hyperglycemia
Rehab after amputation: phases
- 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
Factors influencing post-amputation rehab success
- age
- cognitive status
- concurrent disease/comorbidity
- level of amputation: energy cost
- muscle strength: hip extension/grip
- single limb stance
Why is hip extension and grip strength important for post-amputation success
- hip extension: walking/standing
- grip strength: indicator of health
General Principles of amputation surgery
- 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
Muscle mangement in amputations
- 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
myoplasty
- attach anterior and posterior compartment muscles to each other over the end of the bone
Myodesis
- anchor muscle to bone (rare)
Soft tissue management: skin flaps
- usually as broad as distal end of limb
- shaped to allow corners to retract smoothly
avoid “dog ears”:
