Prosthesis Flashcards
artificial substitute designed to replace a missing limb or body part
Prosthesis
Goals of Prosthesis
Stability
Energy efficiency
Ease of movement
Appearance of normal gait
UE Prosthesis
Body powered or Conventional
External powered or Electric
Passive or Cosmetic
patient uses his/her own residual limb, strength, ROM
Body powered or Conventional
Components of Body Powered or Conventional
Suspension
Socket
Terminal Device
Interposing joints
Control Cable System
interface between residual limb & prosthesis
Socket
Types of Socket (UE Prosthesis)
Dual walled
3-walled
Muenster
fabricated from the custom mold of residual limb (primary interface)
Inner Socket
fabricated to have a normal appearance/contour of the missing body part
Outer Socket
socket commonly seen in pediatric patients
3-Walled
socket commonly seen in very short below elbow amputation
Muenster
holds the residual limb to the prosthesis (socket)
Suspension
Types of Suspension (UE Prosthesis)
Harness-based
Self-suspending sockets
Suction
MC Suspension (UE)
Figure of 8 Strap
Figure of 8 Strap (intact & prosthetic side)
Intact side: harness loops around the axilla
Prosthetic side: anterior strap
indirectly attached to the socket using Y-strap and triceps pad
Transradial
anterior strap directly attached to the socket
Transhumeral
Purpose of shoulder saddle strap with chest strap
Heavy lifting
bony configuration allows suspension
(+) socks
Self-suspending socket
Criteria in using Suction-suspension socket
Good tissue envelope
(-) Scarring
water based/lubricant
creates suction within socket
One Air-Valve Suction
the sleeve rolled onto the residual limb and inserted into the socket to mate the mechanical lock
Silicon Gel Sleeve with Distal Pin Attachment
links the movement of shoulder and humerus to activate the terminal device
Control Cable Mechanism
Motions affecting Control Cable Mechanism
Scapular abduction
Shoulder abduction
Shoulder depression
Elbow flexion
Types of Control Cable Mechanism
Single control or Bowden cables
Dual-Control cable system
replacement for the hand
Terminal Device
Types of Terminal Device
Hooks
Functional/Active hands
Cosmetic/Passive hands
Specialized terminal device
Mechanism of Hooks
Lateral prehension
3 point chuck action
MC used Terminal Device
Functional/Active Terminal Device
MC Active Terminal Device
Voluntary opening
Mechanism of Voluntary opening
Opening: Cable system
Closing: Spring/Plugs
Prehensile strength of Voluntary opening
5-10lbs
Prehensile strength of Voluntary closing
20-25 lbs
Terminal device passively positioned by the patient; less function
Passive/Cosmetic Hand
Elbow unit mechanism
5-130 deg elbow flexion
(-) Full elbow extension
connects the terminal device to prosthesis
Wrist Unit
Types of Wrist Unit
Friction control wrist unit
Lock wrist unit
Wrist flexion unit
for quick changing of terminal device
Quick Disconnect Option
uses small electric motors incorporated to the prosthesis
Externally powered
Control System (Externally powered)
Myoelectrical
Switches
Types of Myoelectrical
Dual-electrode
Single site control
provides passive positioning; lightweight
should match the skin color/texture of intact side
Cosmetic Prosthesis
Post op Care for Transradial Amputation
Rigid Removable Dressing
Initial fitting for UE Prosthesis
3-6 months post-op
until definite prosthesis is prescribed
every 2-6 months
initial routine follow up with a new amputation
within 4-6 weeks after receiving prosthesis
life period of UE Prosthesis
3-5 years
Goals of LE Prosthesis
COsmesis
MObility
Durability
Stability
Components of Transtibial Prosthesis
FOot ankle assembly
Socket
Suspension element
SHank
substitute for the anatomic foot
Foot Ankle Assembly
directly attached to the shank
(-) joint motion
Non-Articulated
weight supporting structure (FAA)
Keel
MC prescribed Foot Ankle Assembly
SACH
Parts of SACH
Keel - firm
Heel - soft
Belting - distal end of keel to end of toes
if heel is too soft
excessive PF; knee flexion
if heel is to firm
excessive DF; knee extension
purpose of belting
prevents toe dropping during swing phase
SACH is common in
K1-K2 walkers
Parts of SAFE
Rigid block
Keel (flexible)
Long plantar ligament band
Energy storing FAA
STEN
Seattle
Carbon Copy II
Quantum
Flex walk
Flex foot
Parts of STEN
3 wooden keel
2 rubber plugs
transfer of WB over the foot compresses the plugs then permits recoil
STEN
earliest energy-storing foot to be commercially available
Seattle
Shape of Keel in Seattle Foot
C-shaped
transfer of WB over the foot bends the keel
stored energy returned during late stance -> forward propulsion
Seattle
lighter, most expensive, stronger FAA
Carbon Copy II
fxn of upper plate (keel)
high impact activities (jumping & running)
fxn of lower plate (keel)
last half of stance phase
Flex walk keel
from MTP joint to heel section
Flex foot keel
from MTP joint to bottom of socket
Energy-storing foot (HEAVY)
SAFE
STEN
Seattle
Energy-storing foot (LIGHT)
Quantum
Carbon Copy II
Energy-storing foot (MEDIOLAT STABILITY)
SAFE
SACH
Quantum
Carbon Copy II
K0
non ambulatory
K1
household ambulator
K2
limited community ambulator
K3
community ambulator
K4
high impact activities
Articulated foot types
Single axis
Multiple axis
PF Bumper
15 def PF only
DF Stop
only 5 deg DF
replacement for the amputated leg
maintains the connection b/w socket & foot
Shank
Exoskeletal
Crustacean Leg
Endoskeletal
Central Support/Pylon
Types of Socket
PTB
Hard Socket
ISNY PTB Socket
composed of thin, flexible thermoplastic PTB socket
ISNY PTB Socket
ISNY PTB Socket covers the
Patellar tendon
Medial flare
Popliteal area
Types of Suspension System
Cuff suspension
Supracondylar System
Suprapatellar System
Thigh Corset
attached to the medial & lateral wall
prevents Genu Recurvatum
Cuff Suspension
mediolateral wall is higher than PTB socket
Supracondylar system
high anterior wall covers the entire patella
Suprapatellar System
oldest form of suspension
Thigh Corset
exerts upward pull to assist in suspension
Elastic Belt
Pressure Tolerant areas
Patellar Tendon
Pretibial muscle
Posterodistal residual limb
Popliteal fossa
Distal end, medial flare lateral tibia
Tibia & fibular shaft
Pressure Sensitive areas
Anterior crest of tibia
Anterior tibia
Hamstrings tendon
Fibular head & neck
Peroneal, Fibular nerve
Components of Transfemoral Prosthesis
FAA
Knee assembly
Socket
Suspension
Shank
Types of Knee axis
Single axis
Polycentric
Types of Friction
Constant Friction
Variable Friction
Fluid Control
control the movement of shank
Friction
if there is no friction
inc knee flexion during early swing phase
abrupt stop with noisy impact during extension
MC type of Friction
Constant Friction
same amount of resistance during swing phase
(+) screw
Constant Friction
Initial & Terminal Swing friction
increase friction
Midswing friction
decrease friction
cadence dependent; simulates normal gait pattern
Fluid Control
controls the heel rise, accelerates shank, replaces the function of quads
Extension Aid
extension lever upper end
knee block
extension level lower end
extension bias spring
(+) harness/strap attached to anterior socket
“Kick strap”
Types of Braking & Locking Mechanism
Weight activated friction brake
Manual lock
Types of LE Socket
Quadrilateral
Ischial Containment
Quadrilateral WB
Ischial tuberosity
Ischial Containment WB
Ischiopubic Ramus
Mechanism of Weight Activated Friction Brake
WB on prosthesis during 20-25 knee flexion -> Automatic locking mechanism
Mechanism of Manual lock
Locking during knee extension during sit to stand
Types of LE Suspension
Suction
Partial suction with Auxillary suspension
Silesian bandage
Pelvic belt
suspension recommended for younger & active patients
Suction
use suction with socks
there is no intimate fit between socket and residual limb
Partial Suction
webbing band around the torso
Silesian Bandage
leather strap with rigid metal band
Pelvic Belt
Energy Expenditure: Wheelchair
9%
Energy Expenditure: Crutches
60%
Energy Expenditure: Single BK
10-40%
Energy Expenditure: Double BK
41%
Energy Expenditure: Single AK
65%
Energy Expenditure: Double AK
100%
Energy Expenditure: Single BK + Single AK
75%
UE Prosthesis Length
3-5 inches
UE Prosthesis Stump/Flap
Fishmouth
UE Prosthesis Shape
Any
BK Prosthesis Length
5-7 inches
BK Prosthesis Stump/Flap
Burgess
BK Prosthesis Shape
Cylindrical
AK Prosthesis Length
> 10 inches
AK Prosthesis Stump/Flap
Fishmouth
AK Prosthesis Shape
Conical