AMPUTATION & ORTHOSIS

Question 1

•Residual limb: Refers to the remaining part of the limb

Sound limb: Refers to the non-amputated limb

Answer 1

…

Question 2

UPPER EXTREMITY AMPUTATION

Answer 2

•Opposable thumb: most important part of the hand
•Goal is to preserve much of the sensate thumb as possible
•Phalagization
–MCP
–Reconstructive technique in which the web space is deepened between digits to provide more mobile digits
•moving a finger with its nerve and blood supply to the site of the amputated thumb

Question 3

CONGENITAL AMPUTATION

Answer 3

•Amelia: Absence of a limb
•Meromelia: Partial absence of a limb
• Phocomelia: flipperlike appendage attached to the trunk
•Adactyly: Absent metacarpal or metatarsal
•Hemimelia: absence of a half a limb
•Acheiria: Missing hand or foot
Aphalangia: absent finger or toe

Question 4

ISPO Classification system for Congenital Upper Arm Limb Reductions

Answer 4

•Transverse deficiency
–No remaining distal portions
–Transverse level is named after the segment beyond which there is no skeletal portion.
•Longitudinal deficiency
–Some remaining distal portions.
Longitudinal deficiencies name the bones that are affected.

Question 5

AMPUTATIONS PROXIMAL TO THE HAND

Answer 5

•Wrist disarticulation:
–Removal of the radius and ulna to the styloid processes, because there is no benefit to retaining the carpal bones.
– It retains the distal radial-ulnar joint, preserving more forearm rotation.
•Transradial amputation
–Myodesis of the forearm muscles and equal volar and dorsal skin flaps for closure
–Extremely functional, with forearm rotation and strength that is proportional to the length retained
–The shorter the transradial amputation, the more the elbow and humerus are needed for suspension
•Elbow disarticulation
–allows the transfer of humeral rotation to the prosthesis, through the myodesis of the biceps and triceps, and it preserves a stronger lever
•Transhumeral amputations
–Performed at or proximal to the supracondylar level
•Shoulder disarticulations
–Through the glenohumeral disarticulations
Scapulothoracis disarticulations
- Forequarter amputations

Question 6

PRINCIPLES of LIMB SALVAGE & AMPUTATION SURGERY

Answer 6

LIMB SALVAGE
•Become possible because of advances in imaging, reconstructive surgery, microsurgery and cancer treatment
•Optimal skin closure
–Pedicle flaps
•A flap in which a local muscle inclusive of the overlying skin is moved over with its own blood supply to fill a large defect.
–Microvascular free flap
A flap in which the donor is not local and the microvasculature of the donor muscle is anastomosed to the available vessels at the defect site.

Question 7

MANGLED EXTREMITY SYNDROME

Answer 7

•Significant injury to at least ¾ tissue groups
–Skin/soft tissue, nerve, vessel or bone
Poor predictor of amputation or salvage with regard to functional outcome

Question 8

MUSCLE PADDING

Answer 8

•Myodesis
–Suturing of deep muscle layers directly to the periosteum
•Myoplasty:
Superficial antagonistic muscles are sutured together and to the deeper muscle layers

Question 9

NEUROMA FORMATION

Answer 9

•Is the normal and expected consequences of nerve division.
Nerves should be gently withdrawn from the wound, sharply divided and allowed to retract under the cover of soft tissue
•Goal is to locate the ends of incised nerves away from areas of external contact
HAND REPLANTATION
•Effective treatment of the patient and the detached body part requires appropriate early cooling and replantation within the initial 12-hour window.
•The decision to replant is based on evidence that the function and overall well-being of the patient will be better than with a prosthetic device
•Best predictor of success: Serum potassium level
If >6.5 mmol/L, replantation should be avoided

Question 10

COMPOSITE TISSUE ALLOGRAFT

Answer 10

•Described the transplantation of multiple tissues (skin, muscle, bone, cartilage, nerve, tendon, blood vessels) as a functional unit.
•Hand transplantation
Goal is 1) achieve graft survival 2) Useful long term function

Question 11

ACUTE MANAGEMENT

Answer 11

•Preamputation
–The surgical team joins forces with the rehabilitation team to educate and counsel each other and the patient. x
•Acute Post-amputation
•Goals:
1) Promote wound healing
2) Control pain
3) Control edema
4) Prevent contracture
5) Initiate remobilization and preprosthetic training
6) Manage expectations through supportive counseling
7) Continue education
PAIN
•Residual limb pain
–located in the remaining limb and generated from the soft tissue and musculoskeletal components
•Phantom limb pain
pain in the absent limb and is considered neuropathic.

Question 12

DESENSITIZATION TECHNIQUES

Answer 12

•Help to eliminate the hypersensitivity to touch
• Include compression, tapping, massage, and application of different textures.
Performed for 20 to 30 minutes 3 times per day as tolerated by the skin and scar

Question 13

EDEMA CONTROL

Answer 13

•Begins once the last suture or staple is placed by the surgeon.
If there is no contraindication and the surgeon has the appropriate training, an •immediate postoperative rigid dressing (IPORD) can be placed in the operating room.
Reduction of edema leads to earlier wound healing and improved pain control through the reduction of pain mediators in the accumulated “third-spaced fluid.

Question 14

HETEROTROPHIC BONE FORMATION

Answer 14

•Diagnosed with triple phase bone scan
•Goals: Maintain ROM
Surgical intervention not feasible until maturity (12-18 months)

Question 15

PREPROSTHETIC TRAINING

Answer 15

•Begins with the early postsurgical therapy visit and continues until prosthetic fitting is completed
• Prosthetic fabrication and fitting ideally should be completed within 4 to 8 weeks after surgery.
Early prosthetic fitting is important, because prosthetic acceptance declines if fitting is delayed beyond the third postoperative month.

Question 16

SPECIFIC MOVEMENTS

Answer 16

•Scapular abduction: Spreading the scapulae apart alone and in combination with humeral flexion will provide the tension needed on the figure-of-eight harness to open the terminal device.
•Humeral flexion: The residual limb is raised forward to shoulder level and pushed forward while sliding the
scapulae apart as far as possible. This motion also allows the terminal device to open.
Shoulder depression, extension, and abduction: This set of movements operates the body-powered, internal-locking elbow of the transhumeral prosthesis.

Question 17

MAINTENANCE OF ROM

Answer 17

•Elbow flexion/extension: Maintaining full elbow range of motion is critical for the transradial amputee for reaching many body locations.
•Forearm pronation/supination: Maintaining as much forearm pronation and supination as possible is critical for the amputee to be able to position the terminal device as needed without having to manually preposition the wrist unit.
Chest expansion: This motion should be practiced by deep inhalations that expand the chest amputation. Chest expansion is used by those who have transhumeral, shoulder disarticulation, or forequarter amputation.

Question 18

PROSTHESIS FOR THE UE

Answer 18

•Four categories
–Passive system
•primarily cosmetic but also functions as a stabilizer
–Body-powered
uses the patient’s own residual limb or body strength and ROM to control the prosthesis.
–Externally powered
•outside power source, such as a battery, to operate the prosthesis.
–Hybrid System
patient’s own muscle strength and joint movement, as well as an external supply for power

Question 19

PROSTHETIC TERMINOLOGY

Answer 19

•Residual limb: The remaining portion of the amputated limb.
•Excursion: Amount of movement or range of motion that the residual limb can achieve.
•Component: A part of the prosthesis.
•Terminal device: The prosthetic equivalent of the human hand.
•Hinge: A prosthetic component used to assist or replace an anatomic joint.
•Rigid hinge: Stiff/solid arrow movement in only one plane, usually flexion and extension.
•Flexible hinge: Allows movement in multiple planes
•Socket: This part of the prosthesis acts as the interface
Between the residual limb and the prosthetic device as a whole; designed to distribute forces throughout the residual limb.
Prosthetic sock: A prosthetic component, usually cotton, which fits the residual limb like a sock and is worn between
•the socket and liner to account for volume changes (size changes) in the residual limb.
Laminate: A plastic composite usually made with carbon fiber and resin.

Question 20

POWER

Answer 20

•Myoelectrically controlled
–uses muscle contractions as a signal to activate the prosthesis.
•Two-site/two function controlled
–Separate electrodes for paired prosthetic activity such as F/E or P/S
One-site/Two Function: single electrode to control both functions of a paired activity

Question 21

PROSTHETIC TERMINOLOGY

Answer 21

•Gel liner: A prosthetic component made from a silicone gel or similar polymer that rolls onto the residual limb like a sleeve and creates a suction interface between the skin and the socket.
•Mechanical: Designates a moving component.
•Passive: Describes a prosthesis used only for cosmesis rather than function.
Heavy duty: It connotes a prosthetic designed to withstand strong, repetitive forces and rugged conditions.

Question 22

LEVEL SPECIFIC

Answer 22

•Option
– no prosthetic intervention
a passive prosthesis –a body-powered prosthesis
– multiple task-specific prostheses
•Wrist disarticulation
Suspended using the patient’s remaining anatomy, specifically the radial and ulnar styloid processes

Question 23

TRANSRADIAL SOCKET

Answer 23

•Designs:
–Muenster: short transradial amputation
–Northwestern: medial-lateral compression of the arm above the epicondyles and less restrictive anterior-posterior compression; long residual limbs; for bilateral amputees
TRAC (Transradial Anatomically Contoured): oth anterior- posterior and medial-lateral compression for enhanced stability and comfort.

Question 24

ELBOW DISARTICULATION

Answer 24

•Long transhumeral socket
•Includes the residual limb and excludes the acromion, the deltopectoral groove, and the lateral border of the scapula
•Least desirable because of the cosmetic asymmetry
However, preferred in children if amputation is bilateral

Question 25

MEDIUM LENGTH TRANSHUMERAL AMPUTATION

Answer 25

• Trim lines up to the acromion and includes the deltopectoral groove and the lateral border of the scapula.
•SHORT TRANSHUMERAL SOCKET
has trim lines that include the acromion and acromioclavicular joint

Question 26

PROXIMAL THIRD OF THE HUMERUS

Answer 26

•Proximal to the deltoid insertion
•Control is by scapular motion with assistance from the humerus
•Reduction in strength and leverage
Shoulder extension, abduction and extension

Question 27

TERMINAL DEVICES

Answer 27

•Passive Terminal Devices
– Functional terminal devices, such as the child mitt frequently used on an infant’s first prosthesis to facilitate crawling, or the ball-handling terminal device used by the older child and adult
– Cosmetic
•Active Terminal Devices
– Hooks, including prehensor, which are devices that have a thumblike component and a finger component producing a claw or bird’s beak type of function
Artificial hands

Question 28

CABLE OPERATED TERMIANL DEVICES

Answer 28

•Voluntary Opening: Most common
Terminal device is closed at rest –Open the terminal device against the resistive force of rubber bands (hook) or internal springs or cables (hand).
–Relaxation of the muscles allows it to close
–The number of rubber bands determines the amount of prehensile force that is generated.
•Voluntary closing
the terminal device is open at rest. The patient uses the control-cable motion to close the terminal device, grasping the desired object

Question 29

PREHENSILE PATTERNS

Answer 29

•Precision grip (i.e., pincher grip): The pad of the thumb and index finger are in opposition to pick up or pinch a small object (e.g., a small bead, pencil, grain of rice).
•Tripod grip (i.e., palmar grip, three-jaw chuck pinch): The pad of the thumb is against the pads of the index and middle finger.
•Lateral grip (i.e., key pinch): Tips of the fingers and thumb are flexed (e.g., when screwing in a light bulb or turning a doorknob).
•Hook power grip: The distal interphalangeal joint and proximal interphalangeal joint are flexed with the thumb extended (as when carrying a briefcase by the handle).
Spherical grip: Tips of the fingers and thumb are flexed (e.g., when screwing in a light bulb or opening a doorknob).

Question 30

CARLYLE FORMULA

Answer 30

•Bilateral transradial amputee: The formula for the distance from the apex of the lateral epicondyle to thumb tip (forearm) is the patient’s body height × 0.21 (in either English or metric units).
Bilateral transhumeral amputee: The formula for the distance from the acromion to the lateral epicondyle (arm) is the patient’s body height × 0.19.

Question 31

OSSEOINTEGRATION

Answer 31

An emerging surgical technique for direct skeletal attachment of the prosthesis

Question 32

INTRO TO PROSTHETIC USE

Answer 32

•Operational knowledge: Basic vocabulary and knowledge of components, including the ability to communicate malfunctions.
• Maintenance and care: Includes socket inspection, maintenance, cleaning, and adjustments.
• Residual limb care: Includes a wearing schedule to progress to full tolerance (∼8 hr/day) and learning routine daily inspection of the residual limb for irritation.
Controls training: Includes learning to control the individual components for operation. The five motion elements that are primarily used in hand manipulation are reach, grasp, move, position, and release. The therapist uses many objects, such as wooded blocks, cotton swabs, and a sponge in training the individual.

Question 33

LOWER LIMB AMPUTATION

DISABILITY RATING

Answer 33

•Loss of one upper limb: 50%
•Loss of one hand: 45%
•Thumb amputation : 23%
EPIDEMIOLOGY
•The prevalence of individuals living with limb loss is anticipated to continue to increase in the future as a result of a number of factors, including the aging of the overall population with increased life expectancy and an increase in the incidence of DM
•The majority of people with lower limb amputations have acquired their amputations as a result of disease processes
•DM increases the risk of amputation to a greater degree than smoking and hypertension

•DM contributes to 67% of all amputations
•Among people with a lower extremity amputation, smoking cigarettes has been associated with a reamputation risk 25 times that of nonsmokers.
•Transtibial level is the most common major amputation level in the lower extremity,
•Trans-femoral being the second most common.
ENERGY EXPENDITURE

Question 34

Post-operative Care

Answer 34

Minimize edema
•Elastic wraps
•Elastic socks or stockinette
•Shrinker
•Prosthetic elastomeric liners
•Rigid dressings
Residual limb wrapping
•↓ edema and prevent venous stasis 
•Shaping
•Help counteract contractures 
•Provide skin protection
•↓ redundant-tissue problems
•↓ phantom limb discomfort/sensation
Desensitize the residual limb with local pain

Question 35

Pre-prosthetic Program

Answer 35

•Involvement of PT and OT should begin ASAP
•Functional rehabilitation: self-care, bed mobility, transfers, wheelchair skills, ambulation, and patient and family teaching
Proper positioning, initiation of ROM, early mobilization, and evaluation for durable medical equipment and adaptive devices.

Proper Positioning
•Prevent hip & knee contractures
•No pillows under the knee or between the legs
•Avoid dangling residual limb over the side of the bed or wheelchair
–Knee extension board
–Knee immobilizer
Lie prone 10 - 15 mins several times a day or supine while performing hip extension exercises

Strengthening Exercises
•Muscles that oppose the common sites of contracture
Knee & hip extensors
Hip adductors & abductors
•Arm strengthening & conditioning
wrist, elbow extensors & scapular stabilizers
Aerobic exercises

Question 36

RESIDUAL LIMB and SKIN CARE

Answer 36

•The residual limb skin of the amputee is subjected to numerous physical stressors.
•Friction, excessive pressures, humidity, sweating, and stretching are some of the mechanical ones that can create problems.
•Clean with soap and water then pat dry
Shrinker or an ACE wrap should be applied to minimize or decrease swelling.
• Botulinum toxin type B (1750 units) has been shown to reduce RLP, PLP, and sweating, and improve duration of prosthetic use and overall quality of life for up to 3 months •or above
Extras (rotators, covers, etc.)

Question 37

PAIN MANAGEMENT

Answer 37

•Residual limb pain (RLP)
–involves pain that is restricted to the anatomic region of the residual limb
•Phantom limb pain (PLP)
–Pain that is perceived in the portion of the limb that is no longer present
•Phantom limb sensation.
If there is no pain associated with amputated part of the limb, but there still are feelings and sensations in the portion of the limb that is no longer present
•RLP
–Neuropathic
•Neuroma
generally aching, cramping, or shooting with an intermittent, episodic nature
CRPS
–Somatic
including HO, infection, tumor, isch- emia, or arthritic joint changes

Question 38

CONSIDERATIONS IN THE PREPROSTHETHIC

Answer 38

•Begins before the surgery and continues until the 1st fitting and training with the prosthesis
•Starting points on the transfemoral limb can be either the ischial tuberosity or greater trochanter, whereas for the transtibial limb the tibial plateau or tibial tubercle can be used. The end point is either the end of the bone or the distal soft tissue
•TRANSTIBIAL: 3-6 inches from MTP
After surgery, the primary emphasis is on wound care and healing, pain management, edema control, maintaining ROM in joints, initiating strength and mobility exercises, overall residual limb and prosthetic use education, and psychological counseling

Question 39

DERMATOLOGIC

Answer 39

•Folliculitis
Hair root infection resulting from poor hygiene, sweating, poor socket fit, or positioning. It is important to clean the area with antiseptic cleanser, to keep it dry, and to consider administration of oral antibiotics.
•Boils and abscesses should be treated with limited prosthetic use.
•Epidermoid cysts occur when sebaceous glands are plugged by keratin and usually are not apparent until months or years after a prosthesis is worn. They grow up to five centimeters in diameter and may break to discharge purulent fluid. They may require incision and drainage.
•Tinea corporis and tinea cruris mainly results from sweating, they may be confirmed through culture or microscopy and are treated by topical or oral fungicides, as well as by good residual limb and socket hygiene.
•Hyperhidrosis (excessive sweating) of the residual limb is a common problem after amputation. Increased sweating on the residual limb may cause skin maceration, which in turn predisposes the skin to infection by bacteria and fungi and injury by outside forces.
Allergic dermatitis may arise from the detergents used to wash the limb socks, from lotions and topical medications, or from agents used in the prosthetic manufacture. The allergic dermatitis should resolve with cessation of contact with the offending agent.

Question 40

CHOKED STUMP

Answer 40

Brawny edema, induration, and discoloration of the skin of •the distal stump in a circular shape may indicate choking.
•Skin of the distal residual limb becomes darkened due to hemosiderin accumulation.
•Occurs when the residual limb becomes larger and no longer fits in the total contact socket.
•The proximal constriction results in obstruction of the venous outflow, producing edema of the distal residual limb.
•If a gap exists between the skin of the distal stump and the distal socket wall, pressure causes edema fluid to accumulate
•Verrucous hyperplasia is a wartlike skin overgrowth, usually of the residual distal limb, resulting from inadequate socket wall contact with subsequent edema formation.
A chronic choke syndrome may lead to verrucous hyperplasia of the distal residual limb skin.

Question 41

SHAPE

Answer 41

The transfemoral residual limb would evolve into a conical shape, whereas the transtibial one should be more of a cylindrical one

Question 42

CRUTCH BEARING MUSCLES

Answer 42

•Latissimus dorsi 
• Triceps
• Biceps
• Quads 
• Hip Extensors 
 Hip Abductors

Question 43

PROSTHETIC TRAINING

Answer 43

•The first principle for the amputee to understand is that the residual limb will vary in volume, and this requires an adjustment of prosthetic fit through the addition or deletion of socks.
–Prosthetic socks commonly come in one, three, five, and six ply.
–Socket : needs 15 ply or more of socks
If the residual limb volume is stable for 8 to 12 weeks, then the time is appropriate for fitting of the definitive prosthesis, which usually occurs around 6 to 18 months after surgery.

Question 44

PROSTHETIC PRESCRIPTION ESSENTIAL ELEMENTS

Answer 44

•Socket
• Interface
• Suspension
• Pylon/frame
• Foot and ankle
• Knee unit if knee disarticulation or above 
Hip joint if hip disarticulation

Question 45

TRANSFEMORAL AMPUTATION

Answer 45

Quadrilateral socket
•allow for muscle function and to provide a seat for the ischium
•4 Distinct Walls
•For long residual limbs and wide mediolateral diameters
4 Walls of the Quadrilateral Socket
•Lateral wall
– supports the femur and provides a surface for the abductor muscles to fire against
•Medial Wall
–in the line of progression and supports the adductor region.
•Posterior Wall
–angled away from the medial wall to allow for function of the gluteal tissue, which is critical for knee stability.
•Anterior Wall
–contoured to compress the Scarpa’s triangle bounded by the inguinal ligament, the adductor tendon, and the sartorius.
–There is relief built into the shape for function of the rectus femoris.
–Compression of the anterior surface provides the counter force that maintains the ischium on the posterior shelf.

Socket
•serves as the platform for connecting the amputated residual limb to the prosthetic limb
•Transtibial socket
•1. Patellar tendon bearing
–major WB area for the residual limb in this design is at the patellar tendon with a counter force in the popliteal region.
•PTB-Supracondylar/Suprapatellar
–ne. By raising the trim line in the medial-lateral dimension to above the medial condyle, additional stabilizing support for the residual limb is pr vided with added suspension.
•Total surface bearing:
–Designed to globally apply forces throughout the residual limb
There is very little pressure difference between areas and limited relief for bony areas.

Question 46

TRANSFEMORAL SOCKET DESIGN

Answer 46

•Quadrilateral socket
–this socket is rectangular in shape with the medial-lateral dimension being greater than the anterior-posterior dimension
–WB is the ischial tuberosity
•Ischial containments
–most commonly used transfemoral socket design
–Ischial tuberosity inside the trimlines
inclusion of the ischium along with the lateral –femur and pubic ramus prevents excessive abduction of the femur and increases medial-lateral stability during the stance phase of gait
–Short residual limb
–Hip adduciton weakness
Subischial Socket
•proximal trim line of this socket falls distal to the ischial tuberosity
•relies completely on the thigh musculature for weight-bearing
involves an elevated suction socket and requires a patient that is attentive to their prosthetic care

Question 47

PROSTHETIC LIMB SUSPENSION

Answer 47

•Suspension is the technique by which the prosthesis is connected and held onto a person’s residual limb

• Suction suspension
–Creating a proximal seal within an airtight socket environment, suction sockets create a slight negative pressure to hold the prosthesis on to the residual limb
•Elevated vaccum suspension
–derivative of suction suspension facilitated in part by the advent of interface liners
•Pin Lock Suspension
Requires a liner with a distal umbrella of an embedded mesh matrix and a threaded attachment site. A locking pin can then be threaded into that liner, which will then engage into a locking mechanism attached to the prosthetic socket

Question 48

PROSTHETIC LIMB FRAME OPTIONS

Answer 48

•Exoskeletal
–Uses a rigid exterior lamination from the socket down and has a lightweight filler inside
–Pro-vides the potential benefit of added strength for heavier patients.
–Durable and can help protect the prosthesis in harsh environment
Endoskeletal
–uses pipes called pylons to connect the prosthetic components. This construction is lighter weight and more modular.
Shank
•Exoskeletal- for patients that will be working in rugged environment. waterproof
–Heavy, for strong patients
•Endoskeletal- for active or weak, elderly patients
–Easily adjustable
With soft cosmetic cover

Question 49

Components of the Below-Knee Prosthesis

Answer 49

Socket
•Connection between the residual limb & the foot
•Means of comfortable weight acceptance of the residual limb during stance on the prosthetic side
•Create a total contact environment between the residual limb and the socket
SocketsPlug-fit
•Prior to the 1950’s
Wooden socket hollowed out to approximate the shape of the limb and the end of the socket is left open.
Patellar-tendon bearing socket
•Has total contact with the residual limb
•Concentrates force in pressure-tolerant areas and relieves force in pressure-sensitive areas
•Alignment:
•↑ socket flexion loads pressure-tolerant areas
foot is aligned medial to the socket for an external knee varus moment distributing force to the medial tibial flare & fibular shaft
Total Surface-Bearing Socket
•Attempts to globally apply forces throughout the residual limb to more evenly distribute the forces that occur during weight-bearing
•The magnitude of these individual forces is then much ↓ than that of the PTB design because of the ↑ area about which these forces are being applied
•Alignment: ↓ initial flexion, foot is ↓ inset
Suspensions
•Used to secure a transtibial prosthesis on the residual limb
•External
•Integral
•System with a locking mechanism
•Fork straps with waist belt
•Cuff
•Sleeve
•Supracondylar suspension
•Supracondylar-Suprapatellar suspension
•Gel or Elastomeric Liner Suspension
•Suction Suspension
Vacuum suspension systems
Fork straps with waist belt
•Fork straps or Y-strap, is attached to the medial & lateral aspects of the socket with the junction proximal to the patella
•No medial-lateral or anterior-posterior support
•Sole purpose is to suspend the prosthesis securely to the waist belt attachment
Used only when maximum security is required and no other suspension technique is viable (e.g., in obese patients)
Cuff
•Suspension is provided on the proximal border of the patella
•A prominent patella is required
•Contraindicated for obese persons or those with excessive thigh musculature.
•Provides an adequate means of suspension between 0 and 60 degrees of knee flexion, and loosens up after 60 degrees of knee flexion to permit comfortable sitting.
Minimal, medial-lateral or anterior-posterior stability to the knee and has considerable pistoning
Sleeve
•Suspension is provided by an elastic material eg. neoprene, latex, silicone, and urethane.
•Some of these sleeves can provide a vacuum seal inside the socket to provide enhanced suspension via suction.
Often difficult to don, retain heat, and provide minimal to no stability about the knee.
Supracondylar Suspension
•Suspension is provided by compression of medial-lateral dimensions of the prosthesis above the femoral epicondyles
•A supracondylar wedge on the medial aspect
•Easily donned and provides good medial-lateral stability
•Tight lateral grasp, because the iliotibial band does not lend itself to pressure like the medial thigh does. pressure and skin breakdown on the medial epicondyle
Contraindicated for obese patients, those with large distal thigh contours and those with superficial vascular bypass grafts close to the medial femoral condyle
Supracondylar-Suprapatellar Suspension
•Added suspension over the proximal aspect of the patella
•Provides a “stop” to help prevent hyperextension of the knee
Individuals with short residual limbs because the forces are distributed over as large a surface area as possible
Gel or Elastomeric Liner Suspension
•Suction sock suspension - silicone, urethane and mineral oil gel
•Applied inside out so that no air becomes trapped between the distal limb and liner
•Joined to the socket by:
Pin, locking mechanism, release button
Lanyard Excellent suspension, transmits great control of the prosthesis, offers better cushioning of the residual limb, ↓ shear forces on the residual limb, and provides a low-profile appearance Suction Suspension
•Suction using a one-way expulsion valve placed in the distal aspect of the socket
•Used in conjunction with gel liners only, whereas others require both the liner and an outer sleeve.
Used when there are space limitations for the locking mechanism or when engaging the pin proves difficult for the user.
Vacuum Suspension System
•Can actively remove air from the inner socket by a mechanical pump (vertical compression unit built into the pylon) or a powered electric pump
•The user wears a gel liner or a sealing sleeve
Excellent suspension & maintains limb volume slower gait speeds, they are indicated for individuals who are able to ambulate with variable cadence (K3 functional classification level).

Question 50

ANKLE ASSEMBLY

Answer 50

Foot Ankle AssemblySACH feet
•Introduced in 1956; one of the most basic & widely used feet
•Solid ankle cushion heel
•Cushion heel can simulate plantarflexion & absorbs shock
•Keels are not responsive to typical loads that they will encounter
Very durable and inexpensive
Single-Axis Feet
Allows motion in the sagittal plane
Allows PF / DF
PF = stability of ambulation
GRF moves forward under the foot; post to anterior knee knee extension moment
Aids in walking on an incline
DF allows to roll over the keel of the foot more readily
Bumpers that are installed anteriorly and posteriorly
Flexible toe section = bends during push-off, returns to neutral during swing phase Multiaxial Feet
Replicates actions of the anatomic foot
Flexible keel, true mechanical joint axes
Plantar flexion and dorsiflexion, inversion and eversion, and transverse plane motion
Fabricated with the materials necessary to enhance their energy return
Dynamic Response Feet
•Enhance the mobility of the user by using materials that are “energy storing.”
•Materials in the keel of these feet are required to deflect under load and return to their original shape propels the foot and leg forward
•Less energy expenditure
BILATERAL AMPUTEES
•Amputees affected on both limb face additional challenges.
•Can be a result of disease processesor traumatic injury.
Up to 50% of unilateral dysvascular amputees will become bilateral amputees over a 5-year period.