Prosthetics Flashcards
What does IPOP stand for?
Immediate Post-Op Prosthesis
What does RRD stand for?
Removable Rigid Dressing
Purpose of the preparatory prosthesis?
to provide early ambulation, shape the residual limb, and be cost effective
What are the material options for the socket of a preparatory prosthesis?
it can be laminated or polypropylene
Is a pylon endoskeletal or exoskeletal?
endoskeletal
What is the purpose of the socks?
the purpose is to provide stability while in the prosthetic
How long does the preparatory stage normally last?
between 4 and 6 months
What will happen to the limb during the preparatory stage? What can be done in relation to fitting?
it will continue to decrease in size due to atrophy of the residual tissue. Extra socks can be added to made up for the loss or socket replacement
What are the advantages/disadvantages of an exoskeletal prosthesis
Advantages: it is durable; lightweight; and cheap
Disadvantages: it isn’t cosmetically pleasing, limited part options, and not alignable
What are the advantages/disadvantages of an endoskeletal prosthesis?
Advantages: cosmetics, component options, alignable
Disadvantages: not as durable, heavy, expensive
What are the various socket design options for trans-tibial prosthetics?
open end; patella tendon bearing; total surface bearing; knee joint and thigh lacer
What are some of the ways in which a trans-tibial prosthetic can be suspended?
waist belt; suspension sleeve; suction; pin; supracondylar cuff or wedge; sub-atmospheric
How does suction suspension work?
through utilization of an expulsion valve to expel extra air and a suspension sleeve to seal
What form of suspension has a large constant suspension and eliminated positioning?
Sub-Atmospheric
What are the different types of socket liners?
hard; pelite; multi-durometer; gel
What does SACH stand for?
Solid-Ankle-Cushion-Heel
What is a SAFE foot?
Stationary Attachment Flexible Endoskeleton; this foot is flexible.
What are energy storing feet?
Oscar Pistorius
What are the various levels of ability/potential for an amputee?
K0: cant walk even w/prosthesis K1: in home and even surface walking K2: community ambulation K3: various cadences available K4: highly active (athlete)
What is a Symes amputation?
an amputation through the ankle joint leaving the fat pad of the heel as the residual limb.
What are some disadvantages to a syme’s amputation?
can’t weight bear; not many prosthetic options;
would be better to do transtibial
What is the most common place for a sore to develop on the trans-tibial amputee? Why?
Anterior-Distal Tibia (it is bone, rotation or the prosthesis, and forces on that area)
What are the stages of prosthesis design?
Patient eval.; impression technique; positive model modification; socket fabrication; alignment stages (bench, static, and dynamic)
What are the objective of prosthetic fitting?
to maximize weight bearing surface; maintain M-L stability; encourage knee flexion throughout stance phase
What is the formula for pressure?
Pressure = Force/Area
What are the pressure tolerant areas of the tibia?
patella tendon; medial tibial flare; medial tibia; pre-tibial muscles; shaft of fibula; posterior gastrocnemius
What are the pressure sensitive areas on the tibia?
tibial tuercle; tibial crest; Anterior-Distal Tibia; distal fibula; hamstring tendons; fibular head; peroneal nerve
What is done to compensate for pressure sensitive areas?
we build up over them to help relieve pressure
ex: a shelf for the hamstring tendons (at or above patellar tendon)
What effect does socket flexion have?
the greater the flexion of the socket the greater the pressure on the front
What is the landmark for measuring height?
the patellar tendon
What is a problem with void in a vacuum type prosthetic?
it will suck the limb down into the residual space even if it is too big to fit
What is the purpose of socks?
positioning of the limb
What is the purpose of a sleeve?
suspension
Why are socks added throughout the day?
because when a prosthetic is worn all day the residual limb size will fluctuate requiring addition of socks
Should a new amputee wear their prosthetic all day?
No; can take up to a month to reach that point
What is the purpose of proper suspension?
to provide comfort, control, and proprioception
What type of contractures are common for trans-tibial amputees?
Knee/hip flexion contractures
What type of contractures are common for transfemoral amputations?
need to worry about hip flexion and abduction contractures
What is the purpose of a shrinker sock?
to help reduce edema
What are the various components for a transfemoral prosthetic?
Socket; End pad; Suspension
What is crucial to gait for a transfemoral prosthetic?
the ability to maintain knee extension during gait
What is the purpose of the preparatory stage?
to allow for a stable limb volume to be obtained;
helps prevent wearing of excessive socks and socket replacement due to improper fit
What types of materials must be used if placed over a prosthetic for cosmetics?
those that will not interfere with the prosthetic knee
(generally a soft foam)
What are the various socket design options for a definitive trans-femoral prosthetic?
plug fit-open end; quadrilateral; ischial containment
Who invented the ischial containment socket design?
Ivan Long
What are the suspension options for a trans-femoral prosthetic?
TES belt; silesian bandage; hip joint; pelvic band; pelvic belt; suction
What is a downside to a TES belt?
is elastic so it will stretch during gait potentially causing deviations. (may be better as a secondary suspension incase primary fails)
What is a downside to the silesian bandage?
it has a tendency to IR the limb
What is the most stable suspension type for a trans-femoral posthetic?
suction
What is a problem with the pin type suction?
it want to come off the limb so it end up pulling and can cause a fluid fill tissue build up
How does an ICEROSS Seal in liner work?
has a ring that needs to remain in contact with the wall of the prosthetic in order to maintain the seal.
What are the advantages/disadvantages to a single vs. multi ring ICEROSS?
a single ring has the potential to have socks added to it while a multi does not.
a multi ring will maintain suction if a ring fail, but a single ring will lose it
What are the different foot types for a definitive prothesis?
SACH; Single Axis; Multiaxis; Flexible Keel; Energy Storing
What type of feet are used of knee stability is a concern?
a foot that allows the ground reaction force to get ahead of the knee as quickly as possible (allows for maintaining of extension)
What are the different types of prosthetic knees?
single axis; manual locking; weight activated locking; polycentric; pneumatic; hydraulic; MPK (Microprocessor Knee)
What is the difference between a pneumatic and hydraulic?
pneumatic operates with air while a hydraulic operates with water
What population are hydraulic knee prosthetics meant for?
those that walk at multiple speed with various cadences
What does a posterior offset of a knee prosthetic help with?
knee extension due to line of ground reaction force
What knee prosthetic has an on board computer?
Otto Bock C-Leg (processes information at a speed of 50x per second)
What are the various sources of input for the on-board computer in an Otto Bock C-Leg
An ankle stress gauge; knee ankle position; and knee motion
What is the most common place for a sore to develop on the transfemoral amputee?
the lateral-distal femur (it gets pushed to the lateral wall)
What knee type is most common for new amputees?
a safety knee
What is the most common gait deviation in a trans-femoral amputee?
a step to gait pattern due to distrust of the prosthetic (want to get “off” it asap)
What are the biomechanical objectives for a trans-femoral prosthetic?
M-L femoral stabilization (femur wants to move laterally); maintain knee extension during stance phase; allow normal stride length on sound side
What role does knee flexion play at the pelvis?
it allows for the pelvis to dip
What does TKA stand for in relation to prosthetics?
Trochanter/Knee/Ankle
What is the purpose of the TKA?
helps to identify the alignment between the center of socket weight line, the rotation point of the knee and the functional rotation point of the ankle/foot
How do Otto Bock C-Legs do with stair?
they perform very well due to the constant adjustments made by the computer
What effects can alignment have on a prosthesis?
can greatly effect both the comfort and stability of the prosthesis
What should be considered about a prosthetic foot in relation to alignment?
foot length; heel durometer; and heel height
What should be considered about a prosthetic knee in relation to alignment?
functional level of the amputee; sound side strength; and strength of the upper extremity
Why is TKA alignment so important?
it promotes knee stability
What does socket flexion in a trans-femoral prosthetic allows for?
an even stride length
What causes a medial whip?
Prosthetic: ER of Knee; tight socket; mis-aligned toe break
Amputee: gait habit, socket not on right; ER of hip at toe off
What causes lateral whip?
Prosthetic: IR of the knee; loose socket; mis-aligned toe break
Amputee: gait habit, socket not on right; IR of hip at toe off
What causes an ABducted gait?
Prosthetic: too long; medial wall too high; poor femoral stability;
Amputee: Abduction contracture; insecurity by patient requiring wider BOS
What causes a circumducted gait?
Prosthetic: long prosthesis; excessive knee friction; excessive knee stability
Amputee: lack of knee flexing confidence; abduction contracture; weak hip flexors; habit
What causes vaulting?
prosthetic: too long; poor suspension; excessive PF; excessive knee resistance
amputee: fear of to catching; poor hip flexor initiation
What causes heel rise?
Prosthetic: inadequate extension aid; insufficient knee friction; improper knee selection
Amputee: excessive hip flexor use
What causes knee instability?
Prosthetic: excessive DF; poor TKA alignment; insufficient socket flexion; mal-alignment of foot
Amputee: weak hip extensors; hip flexion contracture
What causes uneven timing what a short prosthetic step?
Prosthetic: pain; weak extension aid; unstable knee; excessive DF; poor suspension
Amputee: insecurity; weak hip muscles; poor balance
What causes uneven timing with a long prosthetic step?
Prosthetic: excessive PF; insufficient initial socket flexion
Amputee: flexion contracture; patient insecurity; pain on sound side
What causes a lateral shift?
Prosthetic: foot too far inset; excessive socket ABD
Amputee: weak hip Abductors; narrow gait base
What causes a lateral trunk bend?
Prosthetic: foot outset too far; ineffective lateral socket containment; high medial wall; aligned in abduction
Amputee: inadequate balance; abduction contracture; short residual limb
What causes a toe drag?
Prosthetic: long prosthesis; excessive PF or knee friction
Amputee: weak hip abductors on sound side; poor posture; poor gait habits
What are signs that a patients prosthesis is too long?
patient reports LBP; feels like walking uphill; noticeable rise and drop of shoulder on effected side; reduced arm swing on effected side and increased on sound
What are the four factors that contribute to gait deviations?
the patient; prosthetic alignment; socket fit;
rehab teamwork can resolve these
What knee types prevent heel rise?
pneumatic and hydraulic
