VPO Prosthetics Lecture Flashcards
what is an amputation?
the surgical removal of all or part of a limb or extremity
what is an amputee?
a person who’s had a limb amputated
what is a prosthesis?
an artificial body part, such as a leg, heart, or joint implant
is a prosthesis fxnal or nonfxnal?
can be either, but insurance will likely only cover a fxnal prosthesis
who is a prosthetist?
a person skilled in making or fitting prosthetic devices; specialist in prosthetics
who are the members of the rehab team in amputations?
Patient, physician (physiatrist), nursing, therapists (PT/OT), prosthetist, social worker/case manager, vocational rehab
t/f: the rehab team has to work closely together to achieve the best outcomes
true
what are the steps involved in the amputee/prosthetic process?
ensure proper limb healing
minimize loss of ROM, strength, mobility, and endurance
address psychosocial issues
pre-prosthetic training rehab
eval and prescription
fabrication of prosthesis
deliver/fit prosthesis
rehab/training with prosthesis
monitor fit/fxn of prosthesis
follow-up/adjustments
maintenance/replacements
can we use figure 8 wrapping with the staples/stitches still in?
yup!
which side do we need to be strong with an amputation?
both sides eventually, but the intact limb at first to being using the prosthetic and start WBing
how can we address the psychosocial needs following amputation?
by providing support group resources
what is “pre-prosthetics training” rehab?
rehab before getting a prosthetic that involves avoiding contractures and optimizing strength
t/f: the pt has to have a desire to walk in order for insurance to cover the prosthesis
true
t/f: it is easier to break bad habits early on in rehab then to try to correct them later
true
does recovery speed up or slow down with age and illness?
slows down
what is a common cause of slowed recovery in amputations?
DM
what is the most common type of amputation?
a finger amputation
do finger amputations usually require a prosthesis?
nope
what age group has the highest incidence of amputations?
those over 60 yo > 41-60> younger than 40
what is the most common cause for amputations in those younger than 40 yo?
trauma
why may amputation rates get higher as we age?
bc older people tend to have more comorbidities that put them at a greater infection risks and risk for complications from these infections may result in amputations
a majority of new amputees are male or female?
male (72%)
what is the most common cause for UE/LE amputation?
poor circulation
what are some causes of poor circulation that lead to amputations?
PVD
arteriorsclerosis
DM
other than poor circulation, what are the common causes of UE/LE amputations?
trauma
cancer
congenital
what are common trauma that result in amputations?
MVA
GSW
industrial/farming
do industrial/farming traumas usually result in UE or LE amputations?
UE amputations
what are the goals of prosthetics?
to restore fxnal limb
to decrease pain
to decrease comorbidities
to improve self image
to minimize fxnal limitations
what is the MAIN goal of prosthetics?
to restore fxnal limb for standing, walking, and maybe even running
how does a prosthetic decrease comorbidities?
by allowing the pt to work on their endurance and strength
how can we increase a pt’s self image with a prosthesis?
by using cosmetic covers to hide the hardware and look as normal as possible
what fxnal limitations do we want to minimize with prosthetic use?
loss of ADL, work, and play fxns
t/f: most pts with a prosthetic will return to their PLOF
false, most don’t quite reach their PLOF
what are the two large types of UE prostheses?
body powered
externally powered
is body powered or externally powered UE prostheses more simplistic in control and maintenance?
body powered
which type of UE prosthesis uses the body’s own movt to control the device?
body powered prosthesis
is body powered or externally powered UE prostheses more advanced in control and maintenance?
externally powered
t/f: body powered UE prosthesis can typically be more fxnal than a myoelectric device
true
why do ~50% of pts with a myoelectric (externally powered) UE prothesis discontinue its use?
bc it’s heavy and cumbersome
t/f: the myoelectric UE devices don’t always work perfectly and don’t always give the best dexterity
true
t/f: rehab training is absolutely required for maximum fxnal outcomes with a prosthesis
true
t/f: time to get a prosthesis has no effect on outcomes
false, the longer a pt goes with getting a prosthesis, the less likely they are to ever use one
what are the components of an UE prosthesis?
socket
suspension/interface
control system
elbow
terminal device (hand)
what are the types of UE prosthesis suspensions/interfaces?
pin
harnessing
suction
what type of suspension/interface tends to be the best choice for UE prosthesis? why?
suction bc the sleeve creates suctiona cross the entire limb for good fit
when fitting a harnessing suspection system for UE prosthesis, what position should we put the pt in?
in the most retraction so that they can use pro/retraction to control the device
the elbow in the UE prosthesis can be a ______ system or _____ system
cable, myoelectric
what is the most common terminal device used in an UE prosthesis?
a hook
what is the advantage of a trans-femoral amputation over a knee disarticulation?
it has the ability to attach the knee in a more anatomical position with the prosthesis
what is the advantage of a knee disarticulation over a trans-femoral amputation?
it maintain more of the musculature and WBing
what is a possible downside of the knee disarticulation?
the knee will stick out further when sitting
during the eval for a prosthetic, what should we determine at minimum?
the pt hx
goals
limb condition/sensation/skin integ
limb ROM/strength/ stability/WBing capacity
UE status strength
cognition
residual limb measurements/ cast/scan
environmental barriers
therapy status
t/f: we should make sure the prosthesis is tailored to the pt’s goals
true
if a pt is very unstable in standing, would we give them a really mobile prosthetic foot?
no, we’d give them a more rigid stable foot
why are we worried about a pt’s cognition with prosthetic use?
bc the components can be complex and may requiring maintenance, charging, etc
most users use what interface?
gel liners
is 1 sock ply very thin or very thick? when would it be used?
very thin
used when the limb is very swollen
Is 20 ply very thin or very thick? when would it be used?
very thick
used when the limb is very well maintained and not swollen
what should be done if someone is always using a high sock ply?
call the prosthetist to see about making adjustments to the socket
as the length of the residual limb decreases, what happens?
the mechanical advantage decreases
the surface area for limb WBing decreases
increased limb discomfort and skin irritation
do we usually see endoskeletal or exoskeletal prosthetic components being used? why?
endoskeletal bc they are adjustable
when is maybe the only time we would consider using an exoskeleton over an endoskeleton?
when weight is big barrier
what are the types of suspension in LE prosthesis?
vacuum/suction
lanyard (velcrow)
mechanical (pin)
what are the components of the LE prosthesis?
endo/exoskeleton
socket
suspension
hip joint (hip disarticulation)
knee joint (TFA)
pylon (pipe)
foot
what are the 2 prosthetic socket shapes for a TTA?
PTB (patellar tendon bearing)
TSB (total surface bearing)
what TTA socket has a bar surface for the patellar tendon and is the more traditional socket style?
PTB (patellar tendon bearing)
what TTA socket has less shape and is more rounded with relief for bony areas?
TSB (total surface bearing)
what are the TFA socket types?
quad socket
ischial containment socket
what type of TFA socket is more common?
the ischial containment socket
which type of TFA socket is tight A/P?
quad socket
which type of TFA socket is tight M/L?
ischial containment socket
which type of TFA socket locks on the ischium?
ischial containment socket
what are the types of prosthetic socket interfaces?
sheath/nylon
socks
pelite cushion liners
gel liners
why are sheaths/nylon used as an interface?
for decreased friction, increased comfort, and sweat management
what are pelite cushion liners?
foam liners than can add foam to certain areas for a better fit in the socket
what are the 2 suspension options with a gel liner?
pin/velcrow lock
seal-in lock
order these components in order of donning: gel liner, sock ply, sheath
sheath–>gel liner–>sock ply
what are the LE prosthetic suspicion systems?
straps/belts
sleeve
suction/expulsion valve
elevated vacuum/pump
locking/pin
strap/lanyard
when might a joint corset be used in LE prosthesis?
for jt stability, esp with a really tall individual
what k level doesn’t have the ability/potential to ambulate or transfer safely w/ or w/o assistance and a prosthesis doesn’t enhance their QOL or mobility?
K0
t/f: K0 pts are not eligible for any foot/ankle or knee unit or prosthesis
true
what k level has the ability/potential for to use a prosthesis for transfers or ambulation on level surfaces at a fixed cadence (only walking in the home and PT session)?
K1
what k level is typical of the limited and unlimited household ambulator
K1
what feet are K1 users eligible for?
external keel
SACH feet
single axis ankle/feet
what knees are K1 users eligible for?
single axis knee
constant-friction knee
what k level has the ability/potential for ambulation w/the ability to traverse low-level environmental barriers such as curbs, stairs, or uneven surfaces?
K2
what k level is typical of the limited community ambulator and a good starting place for new amputees?
K2
what feet are K2 users eligible for?
flexible-keel feet
multi-axial ankle/feet
what knees are K2 users eligible for?
single axis
constant-friction knee
what k level has the ability/potential for ambulation with variable cadence (typically walking w/o limitations)?
K3
what k level is typical of the community ambulator who has the ability to traverse most environmental barriers and may have vocational, therapeutic, or exercise activity that demands prosthetic utilization beyond simple locomotion?
K3
what feet are K3 users eligible for?
flex-foot
energy storing feet
multi-axial feet/ankle
dynamic response feet
what knees are K3 users eligible for?
fluid knees
pneumatic knees
microprocessor control knees
what k level has the ability/potential for prosthetic ambulation that exceeds basic ambulation skills, exhibiting high impact, stress, or energy levels (athletes)?
K4
who is automatically put into the k4 level?
children, active adults, athletes, and BL users
what k level is typical of prosthetic demands of the child, active adult, athlete, or BL user?
K4
what feet and knees are K4 users eligible for?
any ankle/foot or knee systems
what are the 3 main functions of the foot and ankle?
shock absorption
WBing stability
progression (propulsion)
t/f: all prosthetic foot/ankle options aid in energy return and shock/torque absorption
false, only some do
how are prosthetic feet chosen?
based on k level, amputation level, age, weight, shoe size, and other needs
what is a SACH (solid ankle cushioned heel) foot?
a wood and rubber foot with good stability and lower fxning
does a SACH foot have energy return?
nope
what is a flexible keel foot?
a stable, lower level foot that is not as stiff as a SACH foot that allows smoother gait and decreased stress on the residual limb
more modern SACH foot
what is a single axis foot/ankle?
an ankle with a hinge that allows PF/DF during WBing and improves knee stability
what foot/ankle is a great option for utilization with new TFA amputees?
single axis foot/ankle
what is a multi-axial foot/ankle?
an ankle with a hinge that allows DF/PF, inversion/eversion with WBing that adapt well to terrain and decreases forces on the socket
what K level is the threshold for more dynamic joints?
K3
what is a dynamic response foot/ankle?
a foot/ankle that returns energy back when walking and decreased stress on the residual limb, allowing for higher impact activities
is fiberglass or carbon more flexible, with less energy storage?
fiberglass
is fiberglass or carbon better for energy return?
carbon
what is the main fxnal issue with a symes amputation?
clearance of the foot
t/f: hydraulic feet are energy absorbing
true
what type of foot option has a wide, solid, lowered BOS, typically for TFA?
BL trans-femoral platforms
t/f: running blades are a good option for running and walking
false, they are very uncomfortable for walking
bc the running blades have no heel, if the pt is not bending their knee in stance, what does it feel like?
like they are going to fall back
t/f: there is greater energy return with a longer foot profile
true
what are the basic fxns of prosthetic knees?
to prevent buckling when standing
to allow flexion for sitting, kneeling, and advancing the leg
microprocessors are typically reserved for what k levels?
K3/K4
what is the TKA line?
the line that should be ~10-15 mm anterior to the knee axis to allow prosthetic knee stability
if the knee is in front of the GT, what happens?
the pt will feel unstable
if the knee is behind of the GT, what happens?
the pt will feel too stable and unable to bend the knee
what are the 2 major categories of knees?
mechanical
computerized
what are the 2 mechanical knees?
single axis
polycentrics (more than one axis)
what type of mechanical knee uses 4/5 axes to create the hinge?
polycentrics
what are the prosthetic knee fxns in gait?
stability in stance
swing phase control
what is “flexion resistance”?
knee control of initial swing flexion
what is “extension resistance”?
knee control of late swing knee extension
what is the stance flexion bumper at the knee?
naturally our knees give us ~5-10 deg flexion to accomodate shock, so this is included in prosthetic knees
what are the K1/2 knees?
single axis knee
polycentric knee
what type of knee is a lightweight, simple hinge that is durable and the least expensive?
single axis knee
what are the types of knee locks?
manual lock
friction brake/weight activated lock
what lock gives us the most stable knee?
manual lock
what lock is used for less active amputees, geriatrics, and as a first knee?
friction brake/weight activated
why is circumduction/vaulting often observed with a manual locking knee?
bc of the fully extended knee
what knee lock is used for unstable or very weak amputees?
manual lock knee
polycentric knees provide stability via ____
geometry
t/f: polycentric knees typically have no true lock
true
what is a benefit to the polycentric knee (esp for a knee disarticulation)?
sitting knee looks more normal bc the hinge can go back a bit so the knee doesn’t stick out
what knees for K3/4 users provide increased resistance as the knee flexes and extends?
pneumatic
hydraulic
microprocessor
a microprocessor knee is typically a ___ axis knee with computer control of hydraulic
single
what are the advantages of the microprocessor knee?
ability to control flexion/ extension, adjusting parameters fasters, less effort to control, increased endurance, improved appearance, increased control on uneven surfaces
what are the big downfalls of the microprocessor knee?
the weight and the cost
t/f: specialized prosthetic knees are seen a lot in sports, but don’t walk well
true
what is osseointegration?
an alternative to socket-based traditional designs of prosthetics where the prosthetic is inserted directly into the bone
what is absolutely critical in osseointegration for the prosthetist?
alignment!!!
why is infection a huge risk with osseointegration?
bc the pt will always have an open wound
what are prosthetic causes of ML knee instability during stance phase with a TTA?
Socket ML too wide
Insufficient sock ply
Trimlines too low
what are patient causes of ML knee instability during stance phase with a TTA?
Ligamentous laxity
Insufficient sock ply
Poor shoewear
what are prosthetic causes of excessive knee flexion at initial contact to midstance with a TTA?
Excess flexion in alignment
Heel is too firm
Foot is DFed
Socket anterior to foot
what are patient causes of excessive knee flexion at initial contact to midstance with a TTA?
Poor muscle strength (quads not firing properly)
Weak hip extensors
Residual limb pain
Shoe change (heel higher=automatically more flexed position)
what are prosthetic causes of excessive lateral (varus) thrust during midstance with a TTA?
ML of socket too wide
Foot too inset (too far under them)
Foot too soft
Trimlines too low
what are patient causes of excessive lateral (varus) thrust during midstance with a TTA?
Ligamentous laxity
Residual limb pain
Insufficient sock ply
what are prosthetic causes of delayed knee flexion in end phase of stance with a TTA?
Excessive PF of foot alignment
Foot anterior in relation to socket
Foot too long (not very common)
what are patient causes of delayed knee flexion in end phase of stance with a TTA?
Residual limb pain
Weak hip flexors
what are prosthetic causes of vaulting in stance phase with a TTA?
Prosthesis too long
Poor suspension (falling off in swing phase)
Improper socket fit
what are patient causes of vaulting in stance phase with a TTA?
Weak hip flexors
Habit
Improper management of volume
what are prosthetic causes of insufficient knee flexion in the swing phase with a TTA?
Excessive layers of materials over the knee (the bunching of materials limits available flexion)
Socket too extended (debateable)
Suspension sleeve tension
what are patient causes of insufficient knee flexion in the swing phase with a TTA?
Weak muscular strength
Fear of bending knee
Poor education
what are prosthetic causes of circumduction in swing phase with a TFA?
Knee swing flexion too stiff (can’t flex the knee)
Prosthesis too long
Socket too extended
Inadequate suspension
High medial brim (too high in the groin)
what are patient causes of circumduction in swing phase with a TFA?
Weak muscular strength-hip flexion (can’t drive the prosthesis fwd with hip flexion)
Fear of bending knee
Poor education (poor gait training, lack of PT)
what are prosthetic causes of heel whip in initial swing phase to mid swing phase with a TFA?
Foot too stiff
Poor alignment of knee rotation (ER=med whip, IR=lat whip)
Improper suspension
No muscle contraction space in the socket (mostly for very muscular individuals)
what are patient causes of heel whip in initial swing phase to mid swing phase with a TFA?
Poor hip flexor strength
Poor volume management (poor fitting socket moves the knee orientation)
Improper donning (pt putting on the prosthesis with rotation)
when the knee with a TFA is externally rotated, what heel whip would we see?
medial heel whip
when the knee with a TFA is internally rotated, what heel whip would we see?
lateral heel whip
what are prosthetic causes of abducted gait in the swing and stance phases of gait with a TFA?
Too long
Medial trim too high (going too far into the groin)
Adductor roll pinching (discomfort in the groin)
Knee locked
Knee flexion too stiff
Knee and foot too far inset
what are patient causes of abducted gait in the swing and stance phases of gait with a TFA?
Fear of bending knee
Weak musculature (adductors)
Improper volume management
what are prosthetic causes of knee instability in the stance phase of gait with a TFA?
Stance control insufficiency/poorly adjusted
Socket posterior to knee
PF motion insufficient at heel strike
Foot set in too much DF (stiff knee drives the knee fwd)
what are patient causes of knee instability in the stance phase of gait with a TFA?
Painful residual limb
Weak hip extensors
Lack of gait training
what are prosthetic causes of vaulting in the stance phase of gait with a TFA?
Prosthesis too long
Prosthesis causing brim pressure during WB (in groin)
Inadequate suspension (falling off)
Prosthetic foot PFed
Knee flexion too stiff
Locked knee
what are patient causes of vaulting in the stance phase of gait with a TFA?
Habit
Fear of catching prosthetic foot during swing
Weak unaffected side glute med
what are prosthetic causes of lateral trunk lean in stance phase with a TFA?
Too short
ML too wide
Medial trimline too high (lean to open up the groin area)
Insufficient socket adduction
what are patient causes of lateral trunk lean in stance phase with a TFA?
Pain-distal femur, pubic ramus
Insufficient limb length
Poor suspension
Weak or contracted hip abductors
what are prosthetic causes of terminal impact during swing phase with a TFA (clunking noise at end of swing)?
Insufficient extension resistance
Extension assist too strong
Too heavy
Soft extension bumpers
what are patient causes of terminal impact during swing phase with a TFA (clunking noise at end of swing)?
Habit
Fear of falling
Prefers audible feedback (when they hear the clunk, they know the knee is extended and they won’t fall)
what happens with the foot is set too far back?
a knee flexion moment
when the foot is not set too far back, but the knee is going into flexion, what should we ask the pt about since the last visit? why?
if the changed their shoes bc a higher heel can cause this effect
what happens if the foot is set too far laterally?
a knee valgus moment
what may the pt do to compensate if their foot is set too far laterally causing a valgus moment?
narrow their BOS or trunk lean towards the prosthesis
what happens if the foot is set too far medially?
a knee varus moment
what may the pt do to compensate is their foot is set too far medially causing a varus moment?
trunk lean away from the prosthesis
what happens if the foot is set too far fwd?
a knee extension moment
t/f: having the foot set too far fwd feels like having a foot that is too long
true
if a pt complaints that walking feels like walking uphill, what may be going on?
the foot may be too far fwd, creating knee extension
if a pt complaints that they feel like they are walking into a hole during gait, what may be going on?
the foot may be too far back, creating knee flexion
what happens if the foot is set with too much toe in?
it drives the knee into varus bc the foot rolls out onto the lateral aspect
how much out toeing is normal?
about 5-7 deg
what happens if the foot is set with too much toe out?
it drives the knee into a valgus moment bc the foot rolls in over the medial aspect
t/f: too much DF and a socket that has too much flexion will look the same and cause the same gait deviations
true
is it easier for pts to compensate for a prosthesis that is too long or too short?
too short
with a TFA, do we make the prosthesis a little shorter?
yes, typically about 1/4 to 1/2 in shorter
with a TTA, do we make the prosthesis a little shorter?
no, we typically aim for pretty equal lengths or sometimes 1/4 in shorter in the beginning to take into account the edema reduction that will occur
how many clicks do we want to hear when donning a pin suspension in sitting b4 standing?
at least 2 clicks
pts should don their prosthesis with about ____ deg knee flexion with a TTA
45
if a pt has BL swelling, what should we be concerned about?
CHF
