Exam 5: Prosthetics TransFem ReadGuide/Chart; Sockets, Suspensions

Question 1

Transfemoral Prosthetics Reading Guide:

Contrast the knee disarticulation to the typical TF amputation. (6 points about each)

Answer 1

Transfem

1. Amputation proximal to the anatomical knee joint
2. limb can vary in length
3. RL is likely to be a tapered cylinder- helps with donning/doffing
4. Tapered cylinder shape is more challenging with prosthetic suspension
5. suction suspension may be a good option
6. The shorter the RL, the more difficult socket suspension and knee control is.

Disarticulation

1. Amputation through the center of the anatomical knee joint
2. normal adduction angle for LE is likely preserved
3. longer lever arm
4. bulbous shape due to retention of femur & its condyles- issue for donning/doffing
5. But bulbous shape is good for enhancement of prosthetic suspension
6. distal end of femur tolerated end-bearing pressure

Question 2

Transfemoral Prosthetics Reading Guide:

Features of a transfem (as opposed to a disarticulation) (6)

Answer 2

1. Amputation proximal to the anatomical knee joint
2. limb can vary in length
3. RL is likely to be a tapered cylinder- helps with donning/doffing
4. Tapered cylinder shape is more challenging with prosthetic suspension
5. suction suspension may be a good option
6. The shorter the RL, the more difficult socket suspension and knee control is.

Question 3

Transfemoral Prosthetics Reading Guide:

Featurs of a disarticulation (in contrast to a transfem) (6)

Answer 3

1. Amputation through the center of the anatomical knee joint
2. normal adduction angle for LE is likely preserved
3. longer lever arm
4. bulbous shape due to retention of femur & its condyles- issue for donning/doffing
5. But bulbous shape is good for enhancement of prosthetic suspension
6. distal end of femur tolerated end-bearing pressure

Question 4

Transfemoral Prosthetics Reading Guide:

Describe the relative metabolic cost of ambulation and the functional implications for the elderly TF amputee. (5 points)

Answer 4

1. The shorter the RL, the more energy required in gait.
2. 4 things affecting energy: 1) weight of prosthesis, 2) quality of the socket fit, 3) accuracy of alignment of prosthesis, 4) functional characteristics of prosthetic components
3. Increased energy expenditure= more O2 consumed, increased HR/BP, reduction in comfortable self selected walking speed.
4. High energy need of short RL means that elderly will be limited community ambulators- may require AD and restricted to flat terrain
5. Bilat elderly transfem may opt for a WC for ambulation

Question 5

Transfemoral Reading Guide

4 things affecting energy:

Answer 5

4 things affecting energy:

1. weight of prosthesis,
2. quality of the socket fit,
3. accuracy of alignment of prosthesis,
4. functional characteristics of prosthetic components

Question 6

Transfemoral Reading Guide

How does increased inergy expenditure affect self-selected walking speed?

Answer 6

Increased energy expenditure= more O2 consumed, increased HR/BP, reduction in comfortable self selected walking speed.

Question 7

Transfemoral Reading Guide

Describe the functional implications for the elderly TF amputee.

• Short residual limb
• bilateral amputation

Answer 7

1. High energy need of short RL means that elderly will be limited community ambulators- may require AD and restricted to flat terrain
2. Bilat elderly transfem may opt for a WC for ambulation

Question 8

Transfemoral Reading Guide

What is a Quadirilateral Socket? (7-9)

Answer 8

• Looks squarish
• Remained the socket of choice until the mid-1980s.
• Has four distinct walls
• Two Primary functions
  
  1. provide for weight bearing during the stance phase of gait a
  2. allow the hip and thigh muscles to function at maximum potential during the stance phase
• A flat posterior shelf, the ischial seat, is the primary weight bearing surface for the ischium and gluteal muscles.
• Anterior wall contours create a posterior directed force at the anatomical Scarpa’s triangle, which is intended to stabilize the ischium on its prosthetic seate
• The socket is narrower in its anterior-posterior dimension than its medial-lateral dimension.

The quadrilateral socket is designed for transfemoral (above knee) amputees. The weight bearing in this socket is primarily on the ischium and the gluteal musculature (buttocks). This combination of bone and muscle rests on the posterior brim (back edge) of the socket which creates a wide seat parallel to the ground. This socket can be held in place on the residual limb with suction, a Silesian or TES belt, or by the use of a soft insert with a suspension locking mechanism. This design aids in ease of sitting and, in comparison to the ischial containment socket, is more successful on long, firm residual limbs. (http://www.plor.net/downloads/resources/prosthetics/transfemoral-amputation-and-knee-disarticulation/Prosthetics.QuadrilateralSocket.pdf)

Question 9

What is an Ischial Containment Socket? (7-10)

Answer 9

• newer
• Analogous to the TSB transtib socket.
• It is much better than the quadrilateral socket
• Trim line contains the the ischial tuberosity and creates boney lock that provides mediolateral stability and reduces the likelihood of socket rotation.
• When compared to the quad socket, the most obvious difference is the narrow medial-lateral dimension that is highly contoured around the ischial -ramal complex
• Developed out of the ideas of Ivan Long and John Sabolich. Long believed that by aligning the distal femur over the center of the knee and through the center of the foot, the wearer of the prosthesis could bring their residual limb into a normal anatomical position and walk more naturally. Sabolich expanded on Long’s ideas to make the contoured anterior trochanteric-controlled alignment method which maintains an adducted position and controls socket rotation by containing the ischial tuberosity within the contours of the socket.
  
  • Long’s socket design was part of a frontal plane alignment procedure that became known as “ Long’s Line.”
  • His ideas were expanded on by John Sabolich to make the contoured anterior trochanteric-controlled alignment method (CAT-CAM) socket.
  • Since the CAT-CAM a series of designs have developed that have become known as ischial containment or Ischial-ramal containment sockets (ICS)
• Compared to quad: Narrowed medial-lateral dimension and increased the anteroposterior dimension. The narrow medial-lateral walls better supported the femur to prevent lateral shifting of the socket during stance. The larger anteroposterior dimension allowed better muscle function because there was additional room for muscles to contract.

Question 10

Transfemoral Reading Guide: Contrast the quadrilateral socket to the ischial containment socket for:

• Dimensions
• Weight Bearing
• Femur Position
• Gait
• Energy Expenditure
• Comfort
• Medial-Lateral Pelvic Stability

Answer 10

• Dimensions-
  
  • The quadrilateral socket is narrower in its anterior-posterior dimension than its medial-lateral dimension. It is wider in its medial-lateral dimension, which caused an abnormal abduction angle of the femur. (allows the socket to displace laterally during midstance, thus increasing pressure to the perineal tissues and decreasing the efficiency of the glute med muscle).
  • The ICS has a narrower mediolateral dimension and larger anteroposterior dimension to support the femur and prevent lateral shifting of the socket during weight bearing. The bigger anteroposterior socket dimension also enhances muscle function by producing more room to accommodate contraction than was possible with the AP dimensions of the quad socket
• Weight-bearing-
  
  • quad socket- a flat posterior shelf, the ischial seat, is the primary WB surface for the ischium and gluteal muscles
  • ICS - more like total surface bearing. There is no ischial seat and weight bearing occurs predominantly on the soft tissues of the thigh, gluteal region, and medial aspect of the ischium. (pg 671-672; third edition)
• Femur position-
  
  • Quadrilateral has wider mediolateral walls which abducted the leg more than was ideal and contributed to a wide based gait and a Trendelenburg gait where the individual leaned toward their prosthetic side for compensation.
  • ICS is more narrow mediolaterally and allows more anterior posterior room. This means the femur is in a more natural adducted position. The lateral socket wall is contoured in adduction, with additional pressure against the posterior shaft of the femur for added stability and rotational control.
  • It is debated that femur position is affected by surgery, not the socket. (however, there were pictures in the book and it seemed generally accepted that the ICS keeps the femur in more natural alignment, as opposed to the abnormally abducted resting position in the quad socket)
• Gait
  
  • The ICS results in a more natural gait because of better femoral alignment and less likelihood of socket rotation. There is less need for compensation for a wide based gait (see medial-lateral pelvic stability)
  • Energy expenditure
  • ICS is is more efficient because it allows a more natural gait which uses less energy than the quad socket. (see medial-lateral pelvic stability)
• Comfort
  
  • Chart says there is more area for pressure distribution in the ICS compared to the quadrilateral, so the ICS is more comfortable than the quadrilateral
  • Other reasons I imagine the ICS socket is more comfortable are as follows: It more closely resembles the shape of a thigh. The brim of the socket captures more of the adductor muscle complex than does the quad socket and prevents pinching in the case of an adductor roll. It reduces socket rotation on the limb, increase the efficiency of gait, and distributes weight more evenly (pg 671, third edition).
• Medial-lateral pelvic stability- (see “Pelvic Stability” pg 669 of third edition)
  
  • The design of a quad socket primarily applies stabilizing forces in the anteroposterior plane so that there is little to keep the femur from drifting laterally within the socket.
    
    • Consequently, the pelvis drops when the intact limb is in swing phase. To compensate, the prosthetic wearer often leans tor lurches laterally towards the prosthetic side. This strategy improves swing clearance but also results in a wide-based, energy taxing gait. Because the femur is held in an abnormally abducted position, circumduction of the prosthesis during swing is likely to occur.
  • ICS has a narrower medial-lateral dimension than the Quad socket and is highly contoured to match the unique shape of the user’s residual limb,
  • ICS provides better mediolateral stability (which is a common problem for transfem amputees, especially those with short residual limbs, or who have developed flexion, abduction, and external rotation contractures.
  • In contrast to the quad socket, the IRC socket attempts to hold the femur in its normal adducted position during stance with an upward and medially directed force along the length of the lateral femur. This strategy enhances prosthetic wearer’s ability to maintain a level pelvis and improves the quality of functional gait.

Question 11

Transfemoral Reading Guide: Contrast the quadrilateral socket to the ischial containment socket for:

• Dimensions

Answer 11

Dimensions-

• The quadrilateral socket is narrower in its anterior-posterior dimension than its medial-lateral dimension. It is wider in its medial-lateral dimension, which caused an abnormal abduction angle of the femur. (allows the socket to displace laterally during midstance, thus increasing pressure to the perineal tissues and decreasing the efficiency of the glute med muscle).
• The ICS has a narrower mediolateral dimension and larger anteroposterior dimension to support the femur and prevent lateral shifting of the socket during weight bearing. The bigger anteroposterior socket dimension also enhances muscle function by producing more room to accommodate contraction than was possible with the AP dimensions of the quad socket

Question 12

Transfemoral Reading Guide: Contrast the quadrilateral socket to the ischial containment socket for:

• Weight Bearing

Answer 12

Weight-bearing-

quad socket- a flat posterior shelf, the ischial seat, is the primary WB surface for the ischium and gluteal muscles

ICS - more like total surface bearing. There is no ischial seat and weight bearing occurs predominantly on the soft tissues of the thigh, gluteal region, and medial aspect of the ischium. (pg 671-672; third edition)

Question 13

Transfemoral Reading Guide: Contrast the quadrilateral socket to the ischial containment socket for:

• Femur Position

Answer 13

Femur position-

• Quadrilateral has wider mediolateral walls which abducted the leg more than was ideal and contributed to a wide based gait and a Trendelenburg gait where the individual leaned toward their prosthetic side for compensation.
• ICS is more narrow mediolaterally and allows more anterior posterior room. This means the femur is in a more natural adducted position. The lateral socket wall is contoured in adduction, with additional pressure against the posterior shaft of the femur for added stability and rotational control.
• It is debated that femur position is affected by surgery, not the socket. (however, there were pictures in the book and it seemed generally accepted that the ICS keeps the femur in more natural alignment, as opposed to the abnormally abducted resting position in the quad socket)

Question 14

Transfemoral Reading Guide: Contrast the quadrilateral socket to the ischial containment socket for:

• Gait

Answer 14

Gait

The ICS results in a more natural gait because of better femoral alignment and less likelihood of socket rotation. There is less need for compensation for a wide based gait (see medial-lateral pelvic stability)

Question 15

Transfemoral Reading Guide: Contrast the quadrilateral socket to the ischial containment socket for:

• Energy Expenditure

Answer 15

Energy expenditure

ICS is is more efficient because it allows a more natural gait which uses less energy than the quad socket. (see medial-lateral pelvic stability)

Question 16

Transfemoral Reading Guide: Contrast the quadrilateral socket to the ischial containment socket for:

• Comfort

Answer 16

Comfort

• Chart says there is more area for pressure distribution in the ICS compared to the quadrilateral, so the ICS is more comfortable than the quadrilateral
• imagine the ICS socket is more comfortable. It more closely resembles the shape of a thigh. The brim of the socket captures more of the adductor muscle complex than does the quad socket and prevents pinching in the case of an adductor roll. It reduces socket rotation on the limb, increase the efficiency of gait, and distributes weight more evenly (pg 671, third edition).

Question 17

Transfemoral Reading Guide: Contrast the quadrilateral socket to the ischial containment socket for:

• Medial-Lateral Pelvic Stability

Answer 17

Medial-lateral pelvic stability- (see “Pelvic Stability” pg 669 of third edition)

• The design of a quad socket primarily applies stabilizing forces in the anteroposterior plane so that there is little to keep the femur from drifting laterally within the socket.
  
  • Consequently, the pelvis drops when the intact limb is in swing phase. To compensate, the prosthetic wearer often leans tor lurches laterally towards the prosthetic side. This strategy improves swing clearance but also results in a wide-based, energy taxing gait. Because the femur is held in an abnormally abducted position, circumduction of the prosthesis during swing is likely to occur.
• ICS has a narrower medial-lateral dimension than the Quad socket and is highly contoured to match the unique shape of the user’s residual limb,
• ICS provides better mediolateral stability (which is a common problem for transfem amputees, especially those with short residual limbs, or who have developed flexion, abduction, and external rotation contractures.
• In contrast to the quad socket, the IRC socket attempts to hold the femur in its normal adducted position during stance with an upward and medially directed force along the length of the lateral femur. This strategy enhances prosthetic wearer’s ability to maintain a level pelvis and improves the quality of functional gait.

Question 18

Transfemoral Reading Guide

Contrast the rigid and flexible socket. (features, advantages, disadvantages)

Answer 18

Rigid socket

• Features
  
  • consists of a resin-laminated or thermoformed plastic socket that is intended to
  • have an intimate, total contact fit over the entire surface of the residual limb
  • Prosthetic socks are often worn as a soft interface between the socket and residual limb
• Advantages
  
  • Socket is durable, easy to clean, and often less bulky and expensive to produce than flexible sockets
• Disadvantage
  
  • More difficult to adjust the fit of the rigid socket,
    
    • especially for pt. with bony or
    • sensitive residual limbs

Flexible Socket

• Features
  
  • A FS is vacuum formed using any number of flexible thermoplastic materials
  • Encased in a rigid frame, which provides support during WB and helps to maintain socket shape.
• Advantages
  
  • Accommodates to change in muscle shape during contraction and can be easily modified after initial fabrication to provide relief for bony prominences
  • May also be more comfortable to wear, especially in sitting, because there are no hard ridges at the brim to impinge on the groin
  • They are especially useful if suction suspension is desired
• Disadvantage
  
  • less durable
  • more bulky to wear (requires a socket and a frame)
  • more expensive to produce

Question 19

Transfemoral Reading Guide: rigid socket (contrasted to flexible socket)

• Features (3)
• Advantages (3)
• Disadvantages (1-3)

Answer 19

Rigid socket

• Features
  
  • consists of a resin-laminated or thermoformed plastic socket that is intended to
  • have an intimate, total contact fit over the entire surface of the residual limb
  • Prosthetic socks are often worn as a soft interface between the socket and residual limb
• Advantages
  
  • Socket is durable,
  • easy to clean, and
  • often less bulky and expensive to produce than flexible sockets
• Disadvantage
  
  • More difficult to adjust the fit of the rigid socket,
    
    • especially for pt. with bony or
    • sensitive residual limbs

Question 20

Transfemoral Reading Guide: flexible socket (contrasted to rigid socket)

Features (2)

Advantages (3)

Disadvantages (3)

Answer 20

Flexible Socket

• Features
  
  • A FS is vacuum formed using any number of flexible thermoplastic materials
  • Encased in a rigid frame, which provides support during WB and helps to maintain socket shape.
• Advantages
  
  • Accommodates to change in muscle shape during contraction and can be easily modified after initial fabrication to provide relief for bony prominences
  • May also be more comfortable to wear, especially in sitting, because there are no hard ridges at the brim to impinge on the groin
  • They are especially useful if suction suspension is desired
• Disadvantage
  
  • less durable
  • more bulky to wear (requires a socket and a frame)
  • more expensive to produce

Question 21

How does the flexible socket fit into the grand scheme of things? (where would we find it used?)

Answer 21

A flexible socket is usually incorporated into one of the more modern socket designs (TSB for transtibial and ICS for transfemoral). It enhances total surface bearing

Question 22

Describe Pull-in Suction:

• what is it?
• Steps for donning? (3-7)
• Indications (2)
• Advantages (2)
• Disadvantages (3)

Answer 22

Pull-in suction (same as Traditional Pull-in suction)

What is it?

• use negative air pressure, skin to socket contact, and muscle tension to hold the socket onto the limb
• Only creates a negative pressure differential when prosthesis is in swing phase (because of passive expulsion valve)

Steps for Donning

• Can be donned in several ways ways
  
  1. donning sock (cotton stockinette or similar material)
  2. Donning sleeve (parachute nylon or similar material)
  3. elastic bandage to pull the residual limb into the socket
  4. add a lubricant to the skin (e.g. powder) to facilitate the residual limb sliding into the socket
     
     • The liquid powder dries quickly, and suction is achieved.
• Once the limb is well seated in the socket, the sock, sleeve, or elastic wrap is pulled through the valve housing at the distal socket, the air and expulsion valve is then screwed back into place
• The air-expulsion valve is then “burped” by pushing or pulling the valve button, to release any trapped air.

Indications:

1. Requires mature residual limb
2. Requires good stand bal & dexterity to don

Advantages:

1. Additional benefits -Wearer often reports enhanced prosthetic control and a better proprioceptive sense of the prosthesis during walking

Disadvantages

1. Difficult to maintain suction if edema fluctuates
   
   • Requires mature residual limb
2. The high shearing forces associated with donning a suction socket
   
   • may preclude its use for patients with fragile or sensitive skin, painful trigger points, or significant scarring or adhesions.
3. must have considerable agility and balance on the part of the wearer

Question 23

Describe Pull-in Suction:

what is it?

Answer 23

Pull-in suction (same as Traditional Pull-in suction)

What is it?

• use negative air pressure, skin to socket contact, and muscle tension to hold the socket onto the limb
• Only creates a negative pressure differential when prosthesis is in swing phase (because of passive expulsion valve)

Question 24

Describe Pull-in Suction:

• Steps for donning? (3-7)

Answer 24

Steps for Donning

1. Can be donned in several ways ways
   
   • donning sock (cotton stockinette or similar material)
   • Donning sleeve (parachute nylon or similar material)
   • elastic bandage to pull the residual limb into the socket
   • add a lubricant to the skin (e.g. powder) to facilitate the residual limb sliding into the socket
     
     • The liquid powder dries quickly, and suction is achieved.
2. Once the limb is well seated in the socket, the sock, sleeve, or elastic wrap is pulled through the valve housing at the distal socket, the air and expulsion valve is then screwed back into place
3. The air-expulsion valve is then “burped” by pushing or pulling the valve button, to release any trapped air.

Question 25

Describe Pull-in Suction:

• Indications (2)

Answer 25

Indications:

1. Requires mature residual limb
2. Requires good stand bal & dexterity to don

Question 26

Describe Pull-in Suction:

• Advantages (2)

Answer 26

Advantages:

• Additional benefits -Wearer often reports
  
  1. enhanced prosthetic control and a
  2. better proprioceptive sense of the prosthesis during walking

Question 27

Describe Pull-in Suction:

• Disadvantages (3)

Answer 27

Disadvantages

1. Difficult to maintain suction if edema fluctuates
   
   • Requires mature residual limb
2. The high shearing forces associated with donning a suction socket
   
   • may preclude its use for patients with fragile or sensitive skin, painful trigger points, or significant scarring or adhesions.
3. must have considerable agility and balance on the part of the wearer

Question 28

Roll-On suspension liners are incorporated in the following types of suspensions (4)

Answer 28

Included in the following:

1. shuttle lock system,
2. lanyard system,
3. cushion liner with air expulsion valve, and
4. A type of liner is also used in elevated vacuum (as a wicked liner)

Question 29

T/F

Roll-on liners can be worn against the skin

Question 30

true

They are usually worn against the skin

(exception may be if they have a “liner liner” [a type of sheath])

Question 31

What are the three materials that roll-on liners can be made from (and what does Dr. Mincer usually call them)?

Answer 31

1. silicone
2. urethane
3. elastomer

Dr. Mincer sometimes refers to roll-on liners as a silicone liner (or something that includes silicone, might be pull-on silicone liner, or roll-on silicone liner)

Question 32

How is a roll-on liner donned?

Answer 32

Don by turning inside out and then rolling on

(some of the vidoes showed putting alcohol on the outside of the liner to help it roll on, then alcohol evaporated. I think someone using VASS used ointment on the residual limb before applying the liner)

Question 33

Four advantages (including one major advantage) of roll-on liner

Answer 33

1. Major advantage: significant reduction in friction and shear
2. Donning procedure is simple, and can be accomplished while seated
3. Useful for individuals with short RL
4. Useful for individuals with discomfort using traditional pull-in suction method

Question 34

Four disadvantages in using a roll-on liner

Answer 34

1. Expense and durability
   
   • become worn or torn
   • replace 2-3 times a year
2. Increase skin temp and perspiration
3. Rashes or skin irritation
4. Must clean daily (to prevent buildup of perspiration and bacteria)

Question 35

how often do gel liners usually need to be replaced?

Answer 35

replace 2-3 times a year

Question 36

TF Shuttle-lock or Lanyard suspension

• What is it?
• Donning procedure
• Indications (1)
• Advantages (2)
• Disadvantages (2)

Answer 36

What is it?/Donning Procedure

• TF Sockets and suspension chart: “Gel liner with pin or cable, similar to TT”
• Shuttle lock system is called a locking liner- has an external distal cap where a serrated pin screw stick out. Pin screw is intended to go into shuttle lock at the bottom of the socket. To remove, a button must be pressed to release lock
  
  • I have a note that Dr. Mincer said they are seldom used anymore due to common mechanical failure that caused the prosthesis to get stuck on the RL
    
    • Vacuum suction has largely replaced the shuttle-lock
    • But the chart says they are widely used - emailed Dr. mincer to ask about this.
• Lanyard uses locking liner but with a lanyard (strap or cord) attached to the distal cap and threaded through lateral opening in socket. The this is routed through the distal socket to pull the RL into the socket. The lanyard is then attached to the external lateral aspect of the socket using velcro. Many designs also have an additional loop attached to the liner proximally (could have a ski-boot like strap proximally)

Indications (1)

• Used to be Widely used
  
  • Used to be widely used (esp lanyard now, instead of pin and shuttle because of the mechanical problems) but in the past year or two vacuum assisted has moved to the front

Advantages (2)

1. Comfortable due to cushion
2. Secure

Disadvantages (2)

1. Pin can have mechanical problems
2. Traction on skin

Question 37

TF Shuttle-lock or Lanyard suspension

• What is it?

Answer 37

What is it?/Donning Procedure

• TF Sockets and suspension chart: “Gel liner with pin or cable, similar to TT”
• Shuttle lock system is called a locking liner- has an external distal cap where a serrated pin screw stick out. Pin screw is intended to go into shuttle lock at the bottom of the socket. To remove, a button must be pressed to release lock
  
  • I have a note that Dr. Mincer said they are seldom used anymore due to common mechanical failure that caused the prosthesis to get stuck on the RL
    
    • Vacuum suction has largely replaced the shuttle-lock
    • But the chart says they are widely used - emailed Dr. mincer to ask about this.
• Lanyard uses locking liner but with a lanyard (strap or cord) attached to the distal cap and threaded through lateral opening in socket. The this is routed through the distal socket to pull the RL into the socket. The lanyard is then attached to the external lateral aspect of the socket using velcro. Many designs also have an additional loop attached to the liner proximally (could have a ski-boot like strap proximally)

Question 38

TF Shuttle-lock or Lanyard suspension

• Donning procedure

Answer 38

What is it?/Donning Procedure

• TF Sockets and suspension chart: “Gel liner with pin or cable, similar to TT”
• Shuttle lock system is called a locking liner- has an external distal cap where a serrated pin screw stick out. Pin screw is intended to go into shuttle lock at the bottom of the socket. To remove, a button must be pressed to release lock
  
  • I have a note that Dr. Mincer said they are seldom used anymore due to common mechanical failure that caused the prosthesis to get stuck on the RL
    
    • Vacuum suction has largely replaced the shuttle-lock
    • But the chart says they are widely used - emailed Dr. mincer to ask about this.
• Lanyard uses locking liner but with a lanyard (strap or cord) attached to the distal cap and threaded through lateral opening in socket. The this is routed through the distal socket to pull the RL into the socket. The lanyard is then attached to the external lateral aspect of the socket using velcro. Many designs also have an additional loop attached to the liner proximally (could have a ski-boot like strap proximally)

Question 39

TF Shuttle-lock or Lanyard suspension

• Indications (1)

Answer 39

Indications (1)

• Used to be Widely used
  
  • Used to be widely used (esp lanyard now, instead of pin and shuttle because of the mechanical problems) but in the past year or two vacuum assisted has moved to the front

Question 40

TF Shuttle-lock or Lanyard suspension

• Advantages (2)

Answer 40

Advantages (2)

1. Comfortable due to cushion
2. Secure

Question 41

TF Shuttle-lock or Lanyard suspension

• Disadvantages (2)

Answer 41

Disadvantages (2)

1. Pin can have mechanical problems
2. Traction on skin

Question 42

What are three types of TF suction suspension? (and a very brief description of each - a few words)

Answer 42

1. Traditional Suction
   
   1. (bare skin to socket wall)
2. Roll-on Silicone liner (chart) / Suction via cushion liner and valve (reading guide)
   
   • Generally referred to as cushion liner (from book?)
   • (gel liner between skin and socket wall, but no pin)
3. Elevated Vacuum (similar to VASS, Dr. Mincer heasitantly said we could think of them as the same category)
   
   • Similar to roll-on liner suction but with a pump applied after donning

Question 43

alternate names for roll-on sillicone liner (as listed in the chart)

Answer 43

1. Roll-on Silicone liner (chart)
2. Suction via cushion liner and valve (reading guide)
3. Generally referred to as cushion liner (from book?)

Question 44

Suction via cushion liner and valve

• What is it?
• Donning procedure?
• Indications (2)
• Advantages (3)
• Disadvantages (3)

Answer 44

What is it?

• Called Suction via cushion liner and valve in reading guide, Referred to roll-on sillicone liner in chart, and Generally referred to as cushion liner (from book)
• gel liner between skin and socket wall, but no pin
• Similar to the traditional skin suction socket method mentioned previously (but with a liner)

Donning Procedure

• After the liner is donned on the RL, it is pushed into the socket, creating a negative pressure environment by expelling air through the expulsion valve. (usually step on it to get air out)

Indications:

• Requires
  
  • good standing balance and
  • dexterity to don (same as traditional suction)

Advantages (3)

1. Easier to don than traditional suction
2. More energy efficient gait
3. More cushion

Disadvantages (3)

1. Liners need frequent replacement
2. ­heat & perspiration
3. Difficult to maintain suction if edema fluctuates

Question 45

Suction via cushion liner and valve

• What is it?

Answer 45

What is it?

• Called Suction via cushion liner and valve in reading guide, Referred to roll-on sillicone liner in chart, and Generally referred to as cushion liner (from book)
• gel liner between skin and socket wall, but no pin
• Similar to the traditional skin suction socket method mentioned previously (but with a liner)

Question 46

Suction via cushion liner and valve

• Donning procedure?

Answer 46

Donning Procedure

• After the liner is donned on the RL, it is pushed into the socket, creating a negative pressure environment by expelling air through the expulsion valve (usually step on it to get air out).

Question 47

Suction via cushion liner and valve

• Indications (2)

Answer 47

Indications:

• Requires
  
  • good standing balance and
  • dexterity to don (same as traditional suction)

Question 48

Suction via cushion liner and valve

• Advantages (3)

Answer 48

Advantages (3)

1. Easier to don than traditional suction
2. More energy efficient gait
3. More cushion

Question 49

Suction via cushion liner and valve

• Disadvantages (3)

Answer 49

Disadvantages (3)

1. Liners need frequent replacement
2. ­heat & perspiration
3. Difficult to maintain suction if edema fluctuates

Question 50

Elevated Vacuum

• What is it?
• Donning procedure
• Indications (1)
• Advantages (4)
• Disadvantages (2)

Answer 50

What is it?

• Not the same as suction suspension.
• Like suction suspension in that it uses a difference in atmospheric pressure to suspend and secure the socket to the residual limb
  
  • Suction suspension creates negative pressure only during prosthesis unloading (swing phase)
  • Vacuum creates negative pressure at all times (does not depend on limb position)
• A vacuum pump creates negative pressure to remove air from a sealed environment between the total surface bearing socket and a wicked-liner
• Similar to roll-on liner suction but with a pump applied after donning

Donning procedure

• Don like suction suspension via cushion liner (roll-on silicone liner) but use external (vacuum) pump to create suction while seated instead of with one-way valve with weight bearing.

Indications (1)

• none listed.

Advantages (4)

1. Can be donned in sitting
2. Less volume fluctuation
3. Better RL circulation
4. Virtually eliminates pistoning

Disadvantages (2)

1. Liners need frequent replacement
2. ­increased heat and perspiration

Question 51

Elevated Vacuum

• What is it?

Answer 51

What is it?

• Not the same as suction suspension.
• Like suction suspension in that it uses a difference in atmospheric pressure to suspend and secure the socket to the residual limb
  
  • Suction suspension creates negative pressure only during prosthesis unloading (swing phase)
  • Vacuum creates negative pressure at all times (does not depend on limb position)
• A vacuum pump creates negative pressure to remove air from a sealed environment between the total surface bearing socket and a wicked-liner
• Similar to roll-on liner suction but with a pump applied after donning

Question 52

Elevated Vacuum

• Donning procedure

Answer 52

Donning procedure

• Don like suction suspension via cushion liner (roll-on silicone liner) but use external (vacuum) pump to create suction while seated instead of with one-way valve with weight bearing.

Question 53

Elevated Vacuum

• Indications (1)

Answer 53

Indications (1)

• in the past year or two vacuum assisted has moved to the front (most commonly used suspension system) in place of pin and shuttle or lanyard suspension

Question 54

Elevated Vacuum

• Advantages (4)

Answer 54

Advantages (4)

1. Can be donned in sitting
2. Less volume fluctuation
3. Better RL circulation
4. Virtually eliminates pistoning

Question 55

Elevated Vacuum

• Disadvantages (2)

Answer 55

Disadvantages (2)

1. Liners need frequent replacement
2. ­increased heat and perspiration

Question 56

Two types of soft belts (TF suspensions)

Answer 56

Total Elastic Suspension (TES)

Silesian belt

Question 57

Silesian Belt

• What is it?
• Indications (2)
• Advantages (1)
• Disadvantages (1)

Answer 57

What is it?

• Usually made from leather or lightweight webbing
• Is attached to the lateral aspect of the socket, encircles the pelvis, then runs through a loop or buckle on the anterior of the socket

Indications

1. Used as auxiliary suspension with suction
2. May provide adequate suspension for individuals with long residual limbs who are not expected to be vigorous ambulators the SB (as a sole suspension)

Advantages

• Better control of rotation than TES

Disadvantages

• the problem with using this as the sole means of suspension lies with its inability to control residual limb rotation within the socket

Question 58

Silesian Belt

• What is it?

Answer 58

What is it?

• Usually made from leather or lightweight webbing
• Is attached to the lateral aspect of the socket, encircles the pelvis, then runs through a loop or buckle on the anterior of the socket

Question 59

Silesian Belt

• Indications (2)

Answer 59

Indications

1. Used as auxiliary suspension with suction
2. May provide adequate suspension for individuals with long residual limbs who are not expected to be vigorous ambulators the SB (as a sole suspension)

Question 60

Silesian Belt

• Advantages (1)

Answer 60

Advantages

• Better control of rotation than TES

Question 61

Silesian Belt

• Disadvantages (1)

Answer 61

Disadvantages

• the problem with using this as the sole means of suspension lies with its inability to control residual limb rotation within the socket

Question 62

Total Elastic Suspension

• What is it?
• Indications (4)
• Advantages (3)
• Disadvantages (3)

Answer 62

What is it?

• Neoprene, like transtibial sleeve suspension but anchors around pelvis
• reminds me of the sleeve suspension from transtib
• Typically made of elastic neoprene material (like a wet suit)
• Distal sleeve of TES belt fits snugly around the proximal half of the ghigh section of the prosthesis. The neoprene belt encircles the waist and attaches in front with velcro

Indications (4)

• Used as auxiliary suspension with suction (same as Silesian belt)
  
  • excellent auxiliary suspension system
    
    • could be when playing sports or engaging in high activity
• often chosen for
  
  1. recent amputee with RL that has not matured to stable size
  2. older pt’s who are unable to use the pull-in suction or roll-on liners because of UE weakness or pain
  3. those with easily irritated skin or adhesions who cannot tolerate suction

Advantages (3)

1. Easy to don
2. Comfortable to wear
3. Excellent auxiliary suspension system

Disadvantages (3)

1. major disadvantage: limited durability, especially for active ambulators
2. major disadvantage: tendency to retain heat
3. Cannot control residual limb rotation adequately within the socket (even worse than silesian belt)

Question 63

Total Elastic Suspension

• What is it?

Answer 63

What is it?

• Neoprene, like transtibial sleeve suspension but anchors around pelvis
• reminds me of the sleeve suspension from transtib
• Typically made of elastic neoprene material (like a wet suit)
• Distal sleeve of TES belt fits snugly around the proximal half of the ghigh section of the prosthesis. The neoprene belt encircles the waist and attaches in front with velcro

Question 64

Total Elastic Suspension

• Indications (4)

Answer 64

Indications (4)

• Used as auxiliary suspension with suction (same as Silesian belt)
  
  • excellent auxiliary suspension system
    
    • could be when playing sports or engaging in high activity
• often chosen for
  
  1. recent amputee with RL that has not matured to stable size
  2. older pt’s who are unable to use the pull-in suction or roll-on liners because of UE weakness or pain
  3. those with easily irritated skin or adhesions who cannot tolerate suction

Question 65

Total Elastic Suspension

• Advantages (3)

Answer 65

Advantages (3)

1. Easy to don
2. Comfortable to wear
3. Excellent auxiliary suspension system

Question 66

Total Elastic Suspension

• Disadvantages (3)

Answer 66

Disadvantages (3)

1. major disadvantage: limited durability, especially for active ambulators
2. major disadvantage: tendency to retain heat
3. Cannot control residual limb rotation adequately within the socket (even worse than silesian belt)

Question 67

What is the only TF suspension that provides ML stability?

Answer 67

Pelvic band and hip joint

Question 68

Pelvic Band and hip joint

• What is it?
• Indications (1-3)
• Advantages (2)
• Disadvantages (4)

Answer 68

What is it?

• Pelvic belt is made of leather and attached to the prosthesis by means of a metal hip joint. Recently lighter weight plastic materials have been used as an alternative to the metal joint
• Joint should be positioned just superior and anterior to the greater trochanter

Indications (1-3)

• Short, weak, unstable RL
  
  • Traditionally the suspension of choice for those with short RLs

Advantages (2)

1. No need for suction
2. Adds ML hip stability

Disadvantages (4)

1. Heavy
2. Cosmesis (bulkiness under clothing)
3. No movement in frontal plane allowed
4. problematic in sitting (uncomfortable)

*** Picture of pelvic belt is on the left (the right is a silesian belt)

Question 69

Pelvic Band and hip joint

• What is it?

Answer 69

What is it?

• Pelvic belt is made of leather and attached to the prosthesis by means of a metal hip joint. Recently lighter weight plastic materials have been used as an alternative to the metal joint
• Joint should be positioned just superior and anterior to the greater trochanter

*** Picture of pelvic belt is on the left (the right is a silesian belt)

Question 70

Pelvic Band and hip joint

• Indications (1-3)

Answer 70

Indications (1-3)

• Short, weak, unstable RL
  
  • Traditionally the suspension of choice for those with short RLs

*** Picture of pelvic belt is on the left (the right is a silesian belt)

Question 71

Pelvic Band and hip joint

• Advantages (2)

Answer 71

Advantages (2)

1. No need for suction
2. Adds ML hip stability

*** Picture of pelvic belt is on the left (the right is a silesian belt)

Question 72

Pelvic Band and hip joint

• Disadvantages (4)

Answer 72

Disadvantages (4)

1. Heavy
2. Cosmesis (bulkiness under clothing)
3. No movement in frontal plane allowed
4. problematic in sitting (uncomfortable)

*** Picture of pelvic belt is on the left (the right is a silesian belt)

Question 73

TF Sockets and Suspensions Chart:

Quadrilateral Socket

• Indications (1)
• Advantages (1)
• Disadvantages (3)

Answer 73

Indications (1)

• Long time users of this socket (outdated, but some may be attached to their socket or it may work well for them)

Advantages (1)

• none listed

Disadvantages (3)

• Often results in compensated trendellenburg gait
• increased pressure on ischeial tuberosity
• less area for pressure distribution so less comfortable

Question 74

TF Sockets and Suspensions Chart:

Ischial Containment Socket

• Indications (1)
• Advantages (3)
• Disadvantages (1)

Answer 74

Indications (1)

• Virtually all new wearers (it is the modern up-to-date socket)

Advantages (3)

• more femoral stability in frontal plane results in
  
  1. results in mechanical advantage for abductors
     
     • results in less trendelenburg gait

Disadvantages (1)

• Very high trimlines