Prosthetics

Question 1

Major causes for prosthesis

Answer 1

• Amputation
• PVD
• Trauma
• Malignancy & congenital deficiency (Dwarfism)
• High population of diabetes (over the age of 60)
• Trauma for young adults/adolescents

Question 2

Partial foot and Syme’s prosthesis purpose

Answer 2

• Restore function of gait

- Simulate missing foot

Question 3

Transtibial Prosthesis

Answer 3

• Below Knee
• Tibia and fibula are cut through
• Common site for amputations

Question 4

Foot Ankle assemblies for transtibial prosthesis (Prosthetic Feet)

Answer 4

• General outline of patient’s feet
• Heel contact (absorbs shock)
• Plantar Flexes (early stance)
• Simulates MTP hyperextension (late Stance)
• Neutral (During swing)

Question 5

Foot Ankle assemblies for transtibial prosthesis

Nonarticulated feet

Answer 5

• No space between foot and shank

Question 6

SACH Foot

Answer 6

• Nonarticulated
• Solid Ankle cushion
• Very common
• Least Expensive
• No energy storage

Question 7

Safe Foot

Answer 7

• Nonarticulated
• Stationary attachment flexible endoskeleton, more comparable to subtalor joint
• Energy storing/releasing/or dynamic feet
• recoils late stance and returns energy

Question 8

Articulated Feet

Answer 8

• joined by metal bolt, or cable can loosen over time and cause noise

Question 9

Single Axis

Answer 9

• Articulated
• most common
• shock absorbed at rear in front
• Reduces plantar flexion force
• Controls dorsiflexion
• No medial/lateral/ or tansversal motion

Question 10

Multiple Axis

Answer 10

• Articulated
• moves in all planes
• Can reduce pressure of limb
• Less durable over time

Question 11

Rotator and Shock Absorber

Answer 11

• Absorber
• Shear stress reduced by rotator
  a. Placed above prosthetic
  b. Works in transverse plane
• Vertical impact reduced by shock absorber
  a. Decrease slide, reducing chaffing
• For active patients

Question 12

Shank

Answer 12

• The central core of the prosthesis to which the socket, joints and foot are attached

Question 13

Endoskeletal

Answer 13

• Modular Shank
• Strength/Support is provided by pylon tubes
• Light weight
• Provides good alignment capabilities
• Components can be changed easily
• Requires a soft cover for cosmesis (not durable)

Question 14

Exoskeletal

Answer 14

• Shank
• Strength is provided by the outer cosmetic shell of the prosthesis
• Very durable
• Heavier then endodkeletal

Question 15

Transtibial Socket

Answer 15

• The custom shaped receptacle at the proximal end of a prosthesis which holds the residual limb

Question 16

Patellar Tendon Bearing Socket

Answer 16

• PTB

- Total contact with the anterior identation to increase weight bearing on the patellar tendon

Question 17

Computer aided design

Answer 17

• Computer manufactured
• Transtibial Socket
• Molded by electric carver

Question 18

Lined Socket

Answer 18

• Ply of material designed to insulated the exterior of the prosthesis while preserving the interior contours
• Reduces chaffing
• May increase skin temp
• At 15 ply prosthesist alters or replaces socket

Question 19

Unlined Socket

Answer 19

• Hand Socket
• Usually for a patient whose limb has stabilized
• Easier to clean
• Can be more difficult to alter

Question 20

Suspension for Transtibial Prosthesis

Answer 20

• Needed to hold prosthesis during non-impact movement
• Cuff Varients
• Brim Variants
• Distal Attachment
• Thigh Corset

Question 21

Cuff Variants

Answer 21

• Sypracondylar Cuff most common
• Wraps thigh above condyles with straps
• Waist belt and fort strap may be used in addition (Intended for pt’s that engage in activites that increase the time the prosthesis does not hit the ground ie: jumping / ladder climbing)

Question 22

Brim Variants

Answer 22

• No straps are used
• Medial and lateral hulls of the socket extend above the femoral condyles
• A medial wedge is incorporated in the liner or inserted after donning
• Good for LESS ACTIVE pt’s
• Difficult to fabricate / not easily adjustable

Question 23

Distal Attacment

Answer 23

• Transtibial Distal Pin Attachment
• Use of distal metal pin with silicon sheath
• Pin holds prosthesis during swing
• Other types include Vacuum-assisted and osseointegration with pin implantation into distal bone

Question 24

Thigh Corset

Answer 24

• Metal Hinges attach to prosthesis
• Plastic corset hugs the thigh
• Good for pt’s with sensitive skin

Question 25

Transferoral Prosthesis

Answer 25

- Between femoral condyles and greater trochanter - Above Knee - Contains foot-ankle assembly, shank, knee unit, socket, and suspension device

Question 26

Foot-Ankle and Shanks

Answer 26

- Single axis foot more frequently used - Can fit any foot, depends on pt - Usually less energy produced during toe-off - Endoskeletal shank more common (improved appearance)

Question 27

Knee Units

Answer 27

- Axis system - Single axis hinge - Polycentric linkage - Friction Mechanisms - Manual Lock - Friction Brake - Hydraulic or Pneumatic - Microprocessor Controlled - Extension Aid

Question 28

Polycentric Linkage

Answer 28

- Provides improved control during swing and through pivoting bars that increased stability during stance - Creates an extension movement during stance to lock the knee in extension

Question 29

Friction Mechanisms

Answer 29

- Constant Friction: clamps hold bolt around knee | - Variable Friction: High friction at swing, reduced at midswing, and increased again at late swing

Question 30

Manual Lock

Answer 30

- Rod slides into receptacle - Patient releases with an unlocking lever - Will not flex when locked - Good for patients with decreased balance

Question 31

Friction Brake

Answer 31

- Weight bearing lock | - Locks the knee in any position during weight bearing

Question 32

Hydraulic or Pneumatic

Answer 32

- Friction to control swing adjusts with speed of movement | - May include stumble recovery, rapid flexion, causes knee to lock

Question 33

Microprocessor Controlled

Answer 33

- Sensors provide dynamic control of knee friction and locking

Question 34

Extension aid

Answer 34

- Assists knee swing-though

Question 35

Socket for Transfemoral Prosthesis

Answer 35

- Quadrilateral Socket | - Cat-Cam Socket

Question 36

Quadilateral Socket

Answer 36

- older design | - Weight bearing on ischial tuberosity (pt sits on ischial shelf)

Question 37

Cat-Cam Socket

Answer 37

- Contoured Adducted Trochanteric-Controlled Alignment Method - Also called Ishial Containment Socket - Narrow medial-lateral dimension - Stability is provided by bony lock on ischium - More comfortable

Question 38

Transfemoral Suspensions

Answer 38

- Suction - Waist belt, pelvic band and hip joint - Silesian belt - Osseous Integration

Question 39

Suction

Answer 39

- Most common - Donned with a pull sock though vavle hole - Cant use socks to adjust for size changes in residual limb

Question 40

Waist belt, pelvic band and hip joint

Answer 40

- Cumbersome - uncommon

Question 41

Silesian Belt

Answer 41

- Belt around opposite pelvis | - Usually used as auxiliary suspension

Question 42

Osseous Integratoin

Answer 42

- Metal post in femur | - Less Common