4. Upper Limb Prosthetics Flashcards

1
Q

Mention disability rating for UL amputation ๐Ÿ”‘๐Ÿ”‘ EXAM 2019

A
  1. Thumb 23% (50% of one hand)
  2. One Hand 45%
  3. Upper limb 50%

Braddom 6th Edition Chapter 9 Table 9.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When do you name (x) upper amputee as short or long? ๐Ÿ”‘๐Ÿ”‘

A

๐Ÿ’ก Lower Limb 90-50-20 & 60-35-0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Wrist Disarticulation Pros & Cons. Whats ur advice? ๐Ÿ”‘๐Ÿ”‘ Dr. Jamal

A

Pros

  • Spares distal radial ulnar articulation to preserve full forearm supination and pronation.

Cons

  • Extremely long residual limb
  • Needs special thin wrist unit is used along with terminal device (TD)
  • Poor cosmesis

Advice

  • Any wrist disarticulation = less options and poor cosmesis
  • Drawbacks often outweigh the advantages in the long run
  • Below-elbow amputation may be a more appropriate amputation level.

Cuccurollo 4th Edition Chapter 6 P&O pg466

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Transradial Amputation Pros & Cons. Mention 3 Levels. ๐Ÿ”‘๐Ÿ”‘ What is the minimal length? Dr. Jamal

A

Pros:

  • High level of functional recovery (Longer = More Strength & Supination)

Levels

Long: Residual limb length of 55% to 90%

Retains 60 degrees to 120 degrees of supination and pronation.

Optimal body-powered prosthetic restoration to perform physically demanding work.

Good cosmesis with enough space for electronic components

Short: Residual limb length of 35% to 55%

Limited wrist suspension and elbow ROM and flexion strength

Very short: Residual limb length <35%

Retains <60 degrees

Ulna 1.5 to 2 inches long is able to preserve the elbow joint

Cuccurollo 4th Edition Chapter 6 P&O pg466

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Elbow Disarticulation Pros & Cons.

A

Pros

  • Reduction in surgery time and blood loss
  • Improved prosthetic self-suspension
  • Allows greater lifting, pulling, and pushing power compared to above-elbow amputation.
  • No risk of bone spur or heterotopic bone formation at the elbow disarticulation level

Cons:

  • Limitations in externally powered elbow mechanisms at this level of amputation
  • Poor cosmetic appearance

Cuccurollo 4th Edition Chapter 6 P&O pg467

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Transhumeral Amputation. Mention 3 Levels ๐Ÿ”‘๐Ÿ”‘

A

1. Standard transhumeral

Residual limb length of 50% to 90% (best control and function)

2. Short transhumeral

Residual limb length of 30% to 50%

3. Humeral neck

Residual limb length of <30% (shoulder disarticulation)

Cuccurollo 4th Edition Chapter 6 P&O pg467

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Shoulder Disarticulation Pros & Cons. Whats ur advice?

A

No Pros

Cons

  1. Most difficult to fit with a functional prosthesis
  2. Suspension is difficult to maintain.

Advice

  • Better option is to provide a passive, cosmetic prosthesis (shoulder cap)
  • Ultralight passive prosthesis.

Cuccurollo 4th Edition Chapter 6 P&O pg467

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What requirements must an amputee meet before fitting a permanent prosthesis? ๐Ÿ”‘

A
  1. Stump must be edema and pain free
  2. Adequate strength and ROM
  3. Adequate cognitive ability

PMR Secrets 3rd Edition Chapter 35 pg285 q12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Mention 4 functional grips ๐Ÿ”‘๐Ÿ”‘

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Passive Prosthesis. Advantages & Disadvantages.

A

Advantages

  1. Lighter
  2. Best cosmesis
  3. Less harnessing

Disadvantages

  1. High cost if custom made
  2. Least function
  3. Low-cost glove stains easily

Cuccurollo 4th Edition Chapter 6 P&O pg468-469

DeLisa 5th Edition Chapter 74 U & LL Prosthetics pg2036 Table 74.6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Body powered Prosthesis. Types, Advantages & Disadvantages. ๐Ÿ”‘๐Ÿ”‘ Dr. Jamal & Abdulrazaq

A
  1. Voluntary opening (Advantage)
    • Device maintained in closed position by rubber bands or tension springs
    • The amputee uses cable-control harness powered by proximal muscles to open the terminal devices against the force of the rubber bands or spring.
    • To grasp, patient releases the opened terminal device on an object; the rubber bands or spring provide the prehensile force.
    • Each rubber band provides about 1 lb. of pinch force
    • To control the amount of prehensile force, the patient must generate a continued opening force
  2. Voluntary closing (Disdvantage)
    • Prolonged prehension (grip) requires constant pull on the harness
    • Terminal device remains awkwardly open when not in use

Advantages

  1. Moderate cost
  2. Moderately lightweight
  3. Most durable
  4. Highest sensory feedback
  5. Variety of prehensors available for various activities

Disadvantages

  1. Most body movement to operate
  2. Increased energy expenditure
  3. Most harnessing
  4. Least satisfactory appearance

Cuccurollo 4th Edition Chapter 6 P&O pg468-469

DeLisa 5th Edition Chapter 74 U & LL Prosthetics pg2036 Table 74.6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

List 4 Advantages of hooks. ๐Ÿ”‘

A

๐Ÿ’ก Fits labor worker with low income.

  1. Ability to grasp small objects
  2. Durability
  3. Efficiency
  4. Lower maintenance and repair cost
  5. Lighter weight
  6. Resist heat more than artificial hand
  7. Basic grasp function

Braddom 6th Edition

Chapter 6 UL Prosthetics pg167 Box 9.12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Battery powered Prosthesis. Types, Advantages & Disadvantages.

A
  1. Myoelectric-controlled
    • Use surface electrodes placed on the muscles of the residual limb
  2. Microswitch-controlled
    • Push-button switch or a pullswitch to activate the TD

Advantages

  1. Moderate or no harnessing
  2. Least body movement to operate
  3. Moderate cosmesis
  4. More function-proximal areas
  5. Stronger grasp in some cases

Disadvantages

  1. Most expensive
  2. Most maintenance
  3. Limited sensory feedback
  4. Extended therapy time

Reasons

  1. Generate a pinch force greater than that of body-powered controlled hooks (up to 25 lb)
  2. Allow for more precise control

Cuccurollo 4th Edition Chapter 6 P&O pg468-469

DeLisa 5th Edition Chapter 74 U & LL Prosthetics pg2036 Table 74.6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Wrist Units. Function & Types of Locking Mechanism ๐Ÿ”‘๐Ÿ”‘

A

๐Ÿ’ก Do not add components unnecessarily: They increase weight and cost, and can break and need frequent repair.

WRIST UNITS

  1. Attach terminal device
  2. Allow supination pronation
  3. Allow flexion

LOCKING MECHANISM

  1. Friction lock
    • Made from compressed rubber
    • Hold it in a selected position by friction from a compressed rubber washer
  2. Mechanical lock
    • Adjusted by manual rotation and lock
    • Prevents unwanted rotation of the terminal device in the wrist unit when a heavy object is grasped.
    • Able to add flexion for activities of daily living [ADLs]
  3. Electric wrist rotator units

WIRST FLEXION UNIT

  1. Allows manual positioning of the terminal device in either the straight or the flexed position for improved ADL functions.

Cuccurollo 4th Edition Chapter 6 P&O pg469

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Components of Transradial (Below-Elbow) Amputation Prostheses. 6 marks ๐Ÿ”‘๐Ÿ”‘

A
  1. Terminal devices + control cable #1
  2. Wrist units
  3. Socket
  4. Elbow hinge
  5. Upper arm cuff/pad
  6. Harness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How to operate terminal device in UL prosthesis

A
  1. Shoulder flexion
  2. Shoulder abduction
  3. Scapular Retraction โ€œElbowingโ€
17
Q

Types of sockets for transradial amputation

A

1. Split socket

  • Socket encloses the forearm as a shell which is separated during flexion
  • Used for very short residual limbs.

2. Muenster โ€œAnterior-Posteriorโ€

  • Position of pre-flexion
  • Encloses the olecranon and the epicondyle of the humerus.
  • Figure-9 harness (light weight) for control purposes only

3. Northwestern โ€œMedio-Lateralโ€

  • Medial-lateral compression of the arm above the epicondyles
  • Less restrictive anterior-posterior compression

4. TRAC socket

  • Both anterior-posterior and medial-lateral compression
  • More aggressive contouring of the limb to maximize load-tolerant areas

Cuccurollo 4th Edition Chapter 6 P&O pg470

18
Q

Name the three basic types of below elbow hinges. What are the indications? ๐Ÿ”‘๐Ÿ”‘

A

1. FLEXIABLE

  • Long below elbow amputee is required
  • Allow flexion, supination and pronation

2. RIGID

  • Short transradial amputations, more stability is needed.
  • Allows flexion only
  1. Single Axis (one joint-pivot): Provide M-L stability and hyperextension stop
  2. Double Axis (two joints-pivot, polycentric)
  3. Set up Hinge: Very short transradial amputation, takes twice the force (energy cost doubles)

3. FIXED/LOCKED

  • Significant elbow flexor weakness

Cuccurollo 4th Edition Chapter 6 P&O pg470

PMR Secrets 3rd Edition Chapter 35 pg288

19
Q

Under which condition is a Mรผnster suspension is most often prescribed ๐Ÿ”‘ Explain the advantages the epicondyle suspension prosthesis (Mรผnster-type)

A

Very short transradial amputation, the socket is set at 30 degree elbow flexion

PMR Secrets 3rd Edition Chapter 35 pg287 q23

20
Q

List 3 types of suspension in transhumeral prostheses and advantages and disadvantages

A

SELF SUSPENDING

  1. Muenster & Northwestern
    • Ease of use
    • Cons
    • Limited lifting capacity
    • Reduced elbow flexion
    • Poor cosmesis

HARNESS

  1. Figure-9
    • Light duty activies
    • Allow terminal device control cable only
  2. Figure-8
    • Normal duty activities
    • Simple, durable, adjustable
    • Allow dual control cable (elbow & terminal device)
  3. Shoulder saddle and chest strap
    • Greater lifting ability
    • More comfortable than figure-8
    • Difficult to adjust in women because straps cross breasts.
    • Reduced control compared to figure-8 harness

SUCTION

  1. Suction socket with air valve
    • Good soft-tissue cover
    • Secure suspension
    • Elimination of suspension straps
    • Requires stable residual volume
    • Harder to don
  2. Gel sleeve with locking pin
    • Compromised limbs with scarring or impaired skin integrity
    • Accommodate limb volume change with socks
    • Reduced skin shear
    • Greater cleaning and hygiene requirements.
    • Can be uncomfortable in hot climates

DeLisa 5th Edition Chapter 74 U & LL Prosthetics pg2037 Table 74.7

21
Q

Transradial amputation - give 3 common self-suspending systems for a prosthesis ๐Ÿ”‘

A
  1. Muenster
  2. Northwestern
  3. OttoBock
22
Q

Supra-condylar trans-radial socket / Self-suspending socket Advantages, Disadvantages.

A

Humeral epicondyles and the posterior olecranon

Advantage

  • Simple donning on and off
  • Durable
  • Less expensive
  • Light weight
  • Shorter stumps can be fitted

Disadvantage

  • Limited lifting capacity (Suspension is relatively poor)
  • Poor cosmesis
  • Decreased elbow flexion (Munster type)
  • Socket pressures may cause discomfort

DeLisa 5th Edition Chapter 74 UL & LL Prosthetics pg2037 Table 74.7

23
Q

Benefits of Harness Suspension 2 marks. List 3 types and their advantages and disadvantages 3 marks.

A

BENIFITS

  1. Suspend the prosthesis from the shoulder so the socket is held firmly on the residual limb
  2. Utilize body motions as sources of power or force
  3. Transmit this force via a cable system to operate the TD.

1. FIGURE-9 HARNESS

  • Only for controlling the TD
  • Self-suspended transradial socket
  • Lighter and provides a greater freedom and comfort

2. FIGURE-8 HARNESS

  • Transradial, Transhumeral
  • Normal duty activities
  • Simple, durable, adjustable
  • Axillary pressure reduces discomfort

3. CHEST STRAP WITH SHOULDER SADDLE

  • Greater lifting ability
  • More comfortable than figure-8
  • Difficult to adjust
  • Reduced control compared to figure-8 harness

Cuccurollo 4th Edition Chapter 6 P&O pg471

24
Q

The suspension system for a conventional upper extremity prosthesis can be either a figure of 8 or figure of 9 harness. What is the single most important factor when choosing the figure of 8 system instead of the figure of 9 system?๐Ÿ”‘๐Ÿ”‘MOCK

A

Most Important Factor

The figure of 8 system allows the user to carry more weight thus resists displacement of the socket on the residual limb when the prosthesis is subjected to heavy lifting.

Reference: Atlas of Amputations and Limb Deficiencies third edition page 133

Other Factor

Figure of 8 allow for dual control cable system for terminal device and elbow control, while figure of 9 allow for terminal device control only.

Dr. Maitham

25
Q

How much weight can typically be lifted with the upper limb fitted with a prosthesis?

A

Transradial amputation can typically lift 20-30 lb

Transhumeral amputation can be expected to lift 10-15 Ib.

PMR Secrets 3rd Edition Chapter 35 pg289 q28

26
Q

Types of control cable and how to use them

A

Single-control cable system (Bowden cable system)

Prosthesis: Transradial

  • Single purpose, to operate the terminal device only.

Dual-control cable system

Prosthesis: Transhumeral, one cable with two function

  • Flex the elbow unit when the elbow is unlocked
  • Operate the terminal device when the elbow is locked
27
Q

Elbow disarticulation is more desirable in two cases

A
  1. Growing child as epiphysis is preserved and bony overgrowth is prevented.
  2. Functional advantages for the bilateral upper limb amputee
28
Q

Components of Transhumeral (Above-Elbow) Prostheses. 7 marks

A

BELOW ELBOW

  1. Terminal devices + control cable #1
  2. Wrist units
  3. Socket
  4. Elbow hinge
  5. Upper arm cuff/pad
  6. Harness & Control System

ABOVE ELBOW

  1. Terminal devices + control cable
  2. Wrist units
  3. Forearm unit
  4. Elbow unit + control cable
  5. Upper arm unit
  6. Socket
  7. Harness & Control System

Cuccurollo 4th Edition Chapter 6 P&O pg472

29
Q

Mention 4 main categories of upper limb prosthetic systems. Prior to prescribing prosthesis, what would think about?

A
  1. Passive system
  2. Body-powered system
  3. Externally powered system
  4. Hybrid system

Braddom 6th Edition Chapter 9 Box 9.8

30
Q

Transhumeral socket

A

Double-wall construction, with the inner wall providing a snug, total-contact fit and the outer shell providing appropriate length and shape.

Lateral socket wall extends to the acromion

Medial socket wall is flattened below the axilla to help prevent inadvertent socket rotation

Cuccurollo 4th Edition Chapter 6 P&O pg472

31
Q

Elbow unit for transhumeral prosthesis. Types & Indications. 2 marks.

A

1. External (outside) locking elbow

Elbow disarticulations

  • Amputee < 4 cm above the olecranon
  • Not enough space for an internal locking mechanism

2. Internal (inside) locking elbow

Transhumeral and shoulder prostheses

  • Amputee > 4 cm above the olecranon
  • Greater mechanical durability
  • Spring assist for elbow flexion may be provided
  • Cosmetically more appealing

Cuccurollo 4th Edition Chapter 6 P&O pg473

32
Q

Suspension in transhumeral prosthesis. Benefits & Types

A

BENEFITS OF HARNESS

  1. Transmit power to flex the prosthetic forearm
  2. Lock and unlock the elbow unit
  3. Operate the terminal device.

TYPE OF HARNESS

  • Figure-8 and chest strap (medium to heavy weight) is most frequently used for transhumeral prostheses
  • Remember, figure-9 for terminal device cable control only, no harness

Cuccurollo 4th Edition Chapter 6 P&O pg473-474

33
Q

Control system for transhumeral prosthesis. Types and Pros & Cons.

A

๐Ÿ’ก Hybrid control systems may combine body-powered and myoelectric control in the above elbow or shoulder prosthesis

  1. Body-Powered Control Systems
  2. Myoelectric Control Systems
    • Electrical signal produced by voluntary activation of the residual muscles is detected by surface electrodes incorporated into the prosthetic socket.
    • Open terminal device: Wrist extensors (ECR & ECU) or Triceps โ†’ Say Hi
    • Close terminal device: Wrist flexors (FCR & FCU) or Biceps โ†’ Flex the Grip
  3. Electric Switches

Cuccurollo 4th Edition Chapter 6 P&O pg473-474

34
Q

Explain how to flex and extend the arm for transhumeral amputee.

A
  1. When the elbow is extended and unlocked, flexing the shoulder (humeral flexion; assisted by biscapular abduction) transmits force to the forearm lever loop flexing the elbow to the desired level.
  2. If the amputee wishes to use the terminal device at this point, first, he or she locks the elbow (by doing shoulder depression, extension, and abductionโ€”โ€œdown, back, outโ€).
  3. Then, the patient can operate the terminal device by continuation of the control motion โ‡’ shoulder flexion and biscapular abduction
  4. The same combination of shoulder movements are done to lock or unlock the elbow (shoulder depression, extension, and abduction). The elbow extends by gravity when unlocked.
35
Q

Body-powered prosthesis. 4 Advantages and 4 disadvantages

A

Advantages

  1. Lower initial cost
  2. Lighter
  3. Easier to repair
  4. More durable
  5. Higher sensory feedback

Disadvantages

  1. Mechanical appearance
  2. Difficult to use (Needs higher skill)
  3. Dependent on motor strength

Cuccurollo 4th Eidtion Chapter 6 P&O pg475 Table 6-8

Braddom 6th Edition Chapter 9 UL Prosthetics pg167 Table 9.3

36
Q

Myoelectric prosthesis. 4 Advantages and 4 Disadvantages ๐Ÿ”‘๐Ÿ”‘ Leak 21

A

Advantages

  1. Better cosmesis
  2. Less harnessing
  3. Stronger grasp force (More function-proximal areas)
  4. Battery powered, doesnโ€™t depend on motor strength
  5. Least body movement to operate

Disadvantages

  1. More expensive
  2. Heavier
  3. Decreased durability
  4. Daily recharging of batteries
  5. Higher repair cost
  6. Increased energy expenditure
  7. Dependence on battery life

Cuccurollo 4th Eidtion Chapter 6 P&O pg475 Table 6-8

Braddom 6th Edition Chapter 9 UL Prosthetics pg167 Table 9.3