4. Upper Limb Prosthetics Flashcards
Mention disability rating for UL amputation ๐๐ EXAM 2019
- Thumb 23% (50% of one hand)
- One Hand 45%
- Upper limb 50%
Braddom 6th Edition Chapter 9 Table 9.5
When do you name (x) upper amputee as short or long? ๐๐
๐ก Lower Limb 90-50-20 & 60-35-0
Wrist Disarticulation Pros & Cons. Whats ur advice? ๐๐ Dr. Jamal
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
Transradial Amputation Pros & Cons. Mention 3 Levels. ๐๐ What is the minimal length? Dr. Jamal
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
Elbow Disarticulation Pros & Cons.
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
Transhumeral Amputation. Mention 3 Levels ๐๐
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
Shoulder Disarticulation Pros & Cons. Whats ur advice?
No Pros
Cons
- Most difficult to fit with a functional prosthesis
- 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
What requirements must an amputee meet before fitting a permanent prosthesis? ๐
- Stump must be edema and pain free
- Adequate strength and ROM
- Adequate cognitive ability
PMR Secrets 3rd Edition Chapter 35 pg285 q12
Mention 4 functional grips ๐๐
Passive Prosthesis. Advantages & Disadvantages.
Advantages
- Lighter
- Best cosmesis
- Less harnessing
Disadvantages
- High cost if custom made
- Least function
- 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
Body powered Prosthesis. Types, Advantages & Disadvantages. ๐๐ Dr. Jamal & Abdulrazaq
-
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
-
Voluntary closing (Disdvantage)
- Prolonged prehension (grip) requires constant pull on the harness
- Terminal device remains awkwardly open when not in use
Advantages
- Moderate cost
- Moderately lightweight
- Most durable
- Highest sensory feedback
- Variety of prehensors available for various activities
Disadvantages
- Most body movement to operate
- Increased energy expenditure
- Most harnessing
- Least satisfactory appearance
Cuccurollo 4th Edition Chapter 6 P&O pg468-469
DeLisa 5th Edition Chapter 74 U & LL Prosthetics pg2036 Table 74.6
List 4 Advantages of hooks. ๐
๐ก Fits labor worker with low income.
- Ability to grasp small objects
- Durability
- Efficiency
- Lower maintenance and repair cost
- Lighter weight
- Resist heat more than artificial hand
- Basic grasp function
Braddom 6th Edition
Chapter 6 UL Prosthetics pg167 Box 9.12
Battery powered Prosthesis. Types, Advantages & Disadvantages.
-
Myoelectric-controlled
- Use surface electrodes placed on the muscles of the residual limb
-
Microswitch-controlled
- Push-button switch or a pullswitch to activate the TD
Advantages
- Moderate or no harnessing
- Least body movement to operate
- Moderate cosmesis
- More function-proximal areas
- Stronger grasp in some cases
Disadvantages
- Most expensive
- Most maintenance
- Limited sensory feedback
- Extended therapy time
Reasons
- Generate a pinch force greater than that of body-powered controlled hooks (up to 25 lb)
- 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
Wrist Units. Function & Types of Locking Mechanism ๐๐
๐ก Do not add components unnecessarily: They increase weight and cost, and can break and need frequent repair.
WRIST UNITS
- Attach terminal device
- Allow supination pronation
- Allow flexion
LOCKING MECHANISM
- Friction lock
- Made from compressed rubber
- Hold it in a selected position by friction from a compressed rubber washer
- 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]
- Electric wrist rotator units
WIRST FLEXION UNIT
- 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
Components of Transradial (Below-Elbow) Amputation Prostheses. 6 marks ๐๐
- Terminal devices + control cable #1
- Wrist units
- Socket
- Elbow hinge
- Upper arm cuff/pad
- Harness
How to operate terminal device in UL prosthesis
- Shoulder flexion
- Shoulder abduction
- Scapular Retraction โElbowingโ
Types of sockets for transradial amputation
1. Split socket
- Socket encloses the forearm as a shell which is separated during flexion
- Used for very short residual limbs.
2. Muenster โAnterior-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 โMedio-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
Name the three basic types of below elbow hinges. What are the indications? ๐๐
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
- Single Axis (one joint-pivot): Provide M-L stability and hyperextension stop
- Double Axis (two joints-pivot, polycentric)
- 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
Under which condition is a Mรผnster suspension is most often prescribed ๐ Explain the advantages the epicondyle suspension prosthesis (Mรผnster-type)
Very short transradial amputation, the socket is set at 30 degree elbow flexion
PMR Secrets 3rd Edition Chapter 35 pg287 q23
List 3 types of suspension in transhumeral prostheses and advantages and disadvantages
SELF SUSPENDING
- Muenster & Northwestern
- Ease of use
- Cons
- Limited lifting capacity
- Reduced elbow flexion
- Poor cosmesis
HARNESS
- Figure-9
- Light duty activies
- Allow terminal device control cable only
- Figure-8
- Normal duty activities
- Simple, durable, adjustable
- Allow dual control cable (elbow & terminal device)
- 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
- Suction socket with air valve
- Good soft-tissue cover
- Secure suspension
- Elimination of suspension straps
- Requires stable residual volume
- Harder to don
- 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
Transradial amputation - give 3 common self-suspending systems for a prosthesis ๐
- Muenster
- Northwestern
- OttoBock
Supra-condylar trans-radial socket / Self-suspending socket Advantages, Disadvantages.
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
Benefits of Harness Suspension 2 marks. List 3 types and their advantages and disadvantages 3 marks.
BENIFITS
- Suspend the prosthesis from the shoulder so the socket is held firmly on the residual limb
- Utilize body motions as sources of power or force
- 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
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?๐๐MOCK
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