Week 9 Lower Extremity Prosthetics

Question 1

What is a socket?

Answer 1

where the residual limb inserts

Question 2

What is a Pylon?

Answer 2

area below the socket

Question 3

What is the most common cause for LE amputation?

Answer 3

Dysvacular (PVD, DM2)

Question 4

True/False of persons with diabetes who have lower extremity amputation up to 55% will require amputation of the second leg within 2-3 years.

Answer 4

true

Question 5

True/false nearly 50% of the individuals who have an amputation due to vascular disease will die within 5 years

Answer 5

true

Question 6

Should prosthesis be viewed as a tool/ assistive device

Answer 6

yes

Question 7

What is a K level and how many are there?

Answer 7

individual with an amputation functional level
4 levels to describe function

Question 8

does not have the ability or potential to ambulate or transfer with or without assistance and the prosthesis does not enhance their quality of life or mobility

Answer 8

Level 0

Question 9

Has the ability or potential to use prosthesis for transfers or ambulation on level surfaces at fixed cadence. Typical of the limited and unlimited household ambulator

Answer 9

Level 1

Question 10

Has the ability or potential for ambulation with the ability to traverse low level environmental barriers such as curbs, stairs or uneven surfaces. Typical of the limited community ambulator

Answer 10

Level 2

Question 11

Has the ability or potential for ambulation with variable cadence. typical of the community ambulator who has the ability to transverse most environmental barriers and may have vocational, therapeutic or exercise activity that demands prosthetic utilization beyond simple locomotion

Answer 11

level 3

Question 12

Has the ability or potential for prosthetic ambulation that exceeds basic ambulation skills, exhibiting high impact, stress, energy levels. Typical of the prosthetic demands of the child active adult or athlete

Answer 12

level 4

Question 13

What are some immediate post op concerns?

Answer 13

healing
compression/limb shaping
contraction prevention
prevent scar adhesion
preserve or regain strength and stamina

Question 14

What doe a rigid removable dressing do?

Answer 14

contracture prevention
fall prevention

Question 15

what does a shrinker do? and when do you fit a patient with one

Answer 15

6 weeks post op
control edema
phantom pain/sensation management
compression/limb shaping

Question 16

What are the 4 LE prostheses levels

Answer 16

hip disarticulation
transfemoral
transtibial
trans metatarsal

Question 17

Gel liner rolled onto residuum
connecting pin at distal end of liner
locking mechanism incorporated into socket

Answer 17

Pin locking liner

Question 18

What level is most common for a pin locking liner

Answer 18

Transtibial

Question 19

Advantages
Disadvantages to a pin locking liner

Answer 19

advantage: simple easy to maintain
suspension is seen, felt and heard by patient
ease of donning and doffing
liner protects skin from shear and pressure

Disadvantage: pistoning can occur
distal pulling

Question 20

gel liner rolled onto residuum
lanyard connected at distal end of liner
lanyard exit port and velcro anchor incorporated into socket

Answer 20

lanyard

Question 21

what is the common level for a lanyard

Answer 21

transfemoral

Question 22

What are advantages/disadvantaged to a lanyard

Answer 22

advantages: easy to maintain
suspension is seen and felt by the patient
ease of don doff
patient can forcefully pull limb into the socket
liner protects skin from shear and pressure
helps reduce rotation
disadvantage: pistoling can occur
distal pulling

Question 23

gel liner rolled onto residuum
knee sleeve extends from socket to thigh section

Answer 23

sleeve suspension

Question 24

what level is the sleeve suspension used at

Answer 24

only transtibial

Question 25

what are some advantages/disadvantages of sleeve suspension

Answer 25

advantages: simple, easy to maintain ease of donning and doffing liner protects skin from shear and pressure reduce rotation disadvantage: multiple layers of material restricts the knee pistoning can occur

Question 26

gel liner rolled onto residuum sealing gaskets on external surface of liner create an airtight seal agains the interior socket wall one way expulsion valve in socket wall

Answer 26

sealing liner

Question 27

What level is the sealing liner used?

Answer 27

both transtibial and transfemoral

Question 28

what are the advantages/disadvantages to the sealing liner

Answer 28

advantages: liner protects skin from shear and pressure reduce rotation reduce pistoning disadvantage: difficult to don doff difficult to manage volume fluctuations

Question 29

patients uses a donning sleeve or pull sock to pull the residual limb soft tissue into the socket one way expulsion valve in socket wall

Answer 29

skin fit suction

Question 30

what are the advantages/disadvantages to the skin fit suction

Answer 30

advantages: reduced rotation reduced pistoning disadvantages: difficult to don and doff difficult to manage volume fluctuations difficult fitting process

Question 31

What level are suction fit used at

Answer 31

transfemoral only

Question 32

liner is rolled onto the residuum pump mechanism actively evacuates air from the socket maintaining a vacuum environment within the socket knee sleeve extends from socket to thigh creating an airtight seal

Answer 32

elevated vacuum

Question 33

what are the advantages/disadvantages to elevated vacuum

Answer 33

advantages: most solid and secure option solidification of soft tissues eliminates rotation and pistoning encourages circulation in limb reduces or eliminates volume fluctuations disadvantages: very difficult to don and doff multiple layers of material restricts knee flexion more maintenance is required

Question 34

what level is a elevated suction used for

Answer 34

transfemoral and transtibial

Question 35

Typical for a K1 who is very limited or only transfering locking mechanism engages manually or automatically upon full extension user must manually disengage lock to sit

Answer 35

manual lock knees

Question 36

advantages/disadvantages to a manual lock knee

Answer 36

advantages: lightweight low cost certainty and security of locking mechanism disadvantage: no transition from stance phase to swing phase necessitates gait deviations to ambulate

Question 37

Typical for k1-k2 patients braking mechanism engages automatically under load brake disengages automatically when unloaded

Answer 37

stance brake knees

Question 38

Advantages/ disadvantages to stance brake knees

Answer 38

A: light to moderate weight certainty and security of stance brake braking mechanism is typically adjustable less effort needed for patient to control knee in stance disadvantage: necessitates slight gait deviation to ambulate

Question 39

available for k2-k4 patients constructed of a series of linkages design brings the center of rotation proximal and posterior= stability

Answer 39

polycentric knees

Question 40

Advantages/disadvantages to polycentric knees

Answer 40

advantages: inherent stability smooth transition from stance to swing imitates normal knee- better clearance in swing stance flexion is possible disadvantages: patient must control knee in stance- glute activation

Question 41

available for k3 - k4 patients can be single axis or polycentric hydraulic unit provides resistance in stance phase/swing phase

Answer 41

Hydraulic knees

Question 42

advantages/disadvantages hydraulic knees

Answer 42

A: good stance phase stability variation of resistance in stance and swing possible very smooth gait stance flexion is possible D: heavy increased maintenance

Question 43

available for k3-k4 patients haydraulic unit provides resistance in stance and swing hydraulic unit valves are controlled by an onboard programmable processor

Answer 43

microprocessor hydraulic knees

Question 44

advantages/disadvantages for microprocessor hydraulic knees

Answer 44

a: same as hydraulic knees less energy and concentration required by patient d: same as hydraulic knees increased maintenance has to be changed risk of water damage

Question 45

typically for k1-k2 patients rigid wood or plastic core. foam or rubber exterior various durometer materials in heel simulate eccentric plantar flexion

Answer 45

solid cushion ankle

Question 46

advantage/disadvantage to solid ankle cushion heel

Answer 46

A: light weight low maintenance low cost D: unresponsive poor compliance

Question 47

Typical for k2-k3 patients composite or carbon fiber keel compressible heel simulated foot articulation, plantarflexion and dorsi various flexibility categories corresponding to patient weight and activity

Answer 47

flexible keel

Question 48

advantages/disadvantages to flexible keel

Answer 48

a: light weight low maintenance low cost smoother gait some are multiaxial disadvantages: minimal energy return

Question 49

typical for k3- k4 patients series of composite or carbon fiber keels/blades/struts simulated foot articulation, plantarflexion and dorsiflexion various flexibility categories corresponding to patients weight and activity

Answer 49

dynamic response

Question 50

advantages/disadvantages to dynamic response

Answer 50

advantages: very smooth gait mulitaxial energy stored and returned minor torque and shock absorption disadvantage: increased weight high cost

Question 51

typically for k3- k4+ patients series of composite or carbon fiber keels/blades/struts keels designed to flex under high impact simulated foot articulation, PF, DF various flexiability categories corresponding to patient weight and activity

Answer 51

vertical shock

Question 52

advantages/disadvantages to vertical shock

Answer 52

advantages: max energy return max torque and shock absorption max compliance d: max cost

Question 53

true/false every human is in constant sate of volume fluctuations

Answer 53

true

Question 54

true/false socks are used to manage fluid fluctuations during the day

Answer 54

true

Question 55

failure to address volume changes can lead to what

Answer 55

skin breakdown pressure on bony prominences height discrepancy instability socket rotation loss of suspension

Question 56

gait deviation: excessive flexion moment at the knee

Answer 56

prosthetic cause: heel to firm foot too dorsiflexed patient: knee flexion contracture weak knee extensors

Question 57

gait deviation: excessive extension moment at the knee

Answer 57

prosthetic cause: heel to soft foot too plantarflexed

Question 58

gait deviation: uneven step length uneven timing

Answer 58

pain (socket) pain (OA) poor balance fear

Question 59

gait deviation: lateral trunk bend

Answer 59

prosthetic cause: lack of lateral femoral support prosthesis too short Patient: weak abductors

Question 60

gait deviation: abducted gait

Answer 60

prosthetic cause: prosthesis too long pressure on socket Patient: abduction contracture fear, habit

Question 61

gait deviation: circumduction or vaulting

Answer 61

prosthesis: too long knee flexion resistance too high patient: abduction contracture fear of toe clearance habit

Question 62

Gait deviation: knee instability

Answer 62

prosthesis: knee too far anterior heel too firm Patient cause: weak hip extensors

Question 63

Gait deviation: lumbar lordosis

Answer 63

prostheis: insufficient socket flexion patient cause: hip flexion contracture weak hip extensors

Question 64

gait deviation: uneven timing

Answer 64

prosthesis: pain knee flexion resistance too low patient cause: muscle weakness poor balance fear