Exam 5: Prosthetics TransTib ReadGuide/Lecture/Chart, Intro, Sockets Flashcards
Why is it important to individualize prosthetic prescriptions?
One size does not fit all: the ideal prosthesis for one person may be completely useless to another.
It is only with careful consideration of the person’s complete profile that the clinical team can recommend the components and design that will lead to the most optimal prosthetic outcomes.
How does an individual’s functional potential relate to prosthetic prescription?
There are K-Levels from CMS which is a hierarchical system to classify the functional potential of persons with lower limb amputations. Each functional level uses the phrase “has the ability or potential” in the description, because individuals cannot reach their full potential until their prosthesis is provided and rehabilitation has been successful
For certain benefits to be covered under Medicare, the individual must be certified by his or her prosthetist and MD with the appropriate K-level (to prevent prescription of prosthesis with costly components that person will not be able to manage or use effectively).
What are K-levels?
There are K-Levels from CMS which is a hierarchical system to classify the functional potential of persons with lower limb amputations. Each functional level uses the phrase “has the ability or potential” in the description, because individuals cannot reach their full potential until their prosthesis is provided and rehabilitation has been successful
For certain benefits to be covered under Medicare, the individual must be certified by his or her prosthetist and MD with the appropriate K-level (to prevent prescription of prosthesis with costly components that person will not be able to manage or use effectively).
How many K Levels are there and what are thier names?
5 Levels
- K0
- K1
- K2
- K3
- K4
K0
The patient does not have the ability or potential to ambulate or transfer safely with or without assistance and a prosthesis does not enhance quality of life or mobility
K1
The patient has the ability or potential to use a prosthesis for transfers or ambulation on level surfaces at fixed cadence. Typical of the limited and unlimited household ambulator..
K2
The patient has the ability or potential for ambulation with the ability to traverse low-level environmental barriers such as curbs, stairs, or uneven surfaces. Typical of the limited community ambulator.
K3
The patient has the ability or potential for ambulation with variable cadence. Typical of the community ambulator who has the ability to transverse most environmental barriers and may have vocational, therapeutic, or exercise activity that demands prosthetic utilization beyond simple locomotion.
K4
The patient has the ability or potential for prosthetic ambulation that exceeds basic ambulation skills, exhibiting high impact, stress, or energy levels. Typical of the prosthetic demands of the child, active adult, or athlete.
What is the relationship between prostatic weight and design, and weight and energy expenditure?
Prosthetic design is often a compromise of weight versus function.
Increased weight leads to increased energy expenditure and premature fatigue.
However, exclusion of features that the person will need on a regular basis (but may be heavy) may lead to excessive stresses on the limb, premature component wear or breakdown, and inefficient gait.
What does RRD stand for?
Ridgid removeable dressing
What does IPOP stand for?
Immediate postoperative prosthesis
It is an prosthesis made immediately after surgery to help with edema and contracture control as well as early ambulation. I think the socket is usually made out of plaster and custom made.
True/False: wrapping a residual limb postoperatively with an elastic bandage is superior to using a RRD (that’s why we learned it last semseter with Dr. Bringman)
False:
It has ben shown that RRDs provide more favorable outcomes than elastic bandages when used to control postop edema and provide protection to the surgical site.
*We likely learned how to wrap a residual limb with the elastice bandage because it is cheaper (common) and requires practice to learn how to put it on?
What are three good things an RRD does?
- keeps the knee in full extension to prevent contracture
- protects the limb from exterior trauma
- controls swelling through total contact
Describe at least three advantages of the IPOP over the traditional approach of waiting for healing to take place and then fit a prosthesis weeks or months later.
- Includes serving the same purpose as the RRD
- Provides more favorable outcomes than elastic bandages when used to control postop edema and provide protection to the surgical site.
- keeps the knee in full extension to prevent contracture
- protects the limb from exterior trauma
- controls swelling through total contact
- Provides more favorable outcomes than elastic bandages when used to control postop edema and provide protection to the surgical site.
- Allows supported weight bearing for early mobility
How much weight bearing should be allowed through an IPOP?
It is important to note that weight bearing while in an IPOP should be at the level of TTWB. FWB is discouraged as there is generally not enough area to distribute the full body weight in a manner that the skin will tolerate for extended periods of time.
An assistive device should be used
How are IPOPs able to allow weight bearing without hurting the incision?
IPOP sockets are desined to allow some weight-bearing forces direct to the medial tibial flare and patellar tendon because these structures are far from the surgical site and are not likely to be impacted by post-operative edema.
If they are so great, why doesn’t everyone recieve an IPOP?
- IPOP may not be used due to excessive soft tissue damage or delayed wound healing
- I’m thinking that they are also expensive and require specialized equipment and training to fabricate and use (basically a prosthetist has to make them?)
What is the next best thing to the IPOP for achieving residual limb management and how does it work?
(also, what is it made of?)
- a RRD can be used- it can have a custom-molded plaster socket with a prefabricated plastic collar
- RRD helps by- keeping knee in full extension to prevent contracture, protects the limb from exterior trauma, controls the swelling through total contact
What are the two main types of TT (transtibial) sockets?
- Patellar Tendon-Bearing Socket (PTB Socket)
- older; rarely used
- Has a very deep patellar bar
- designed to strategically load the limb in areas that are more pressure tolerant, namely the patellar tendon and medial tibial flare, and to relieve the tissue over bony prominences like the tibial crest and head of the fibula. In most cases, this eliminated the need for proximal WB
- Total Surface-Bearing Socket
- newer; mostly replaced PTB (considered the standard now)
- Less contouring around the patella
- tries to distribute the WB load over the entire surface of the limb (even places that have been traditionally thought as pressure intolerant)
In PTB
What are the two main weight-bearing surfaces?
patellar tendon and medial tibial flare
In the PTB
What is the height of the posterior trimline? Why?
posterior wall is just proximal to the patellar bar to stabilize the limb in the anteroposterior direction and to prevent the limb from sliding too far down into the socket; should be lower on the medial side to accommodate the insertion of the medial hamstring during knee flexion
In the PTB
What residual limb complication results if the patient does NOT have total contact inside the socket?
Swelling of the non-contact areas
What was the goal of the PTB socket?
goal of PTBS- to increase surface area on residuum to eliminate the need for the knee joint and thigh corset (they socket it replaced)
sockets: What is “total contact”?
“total contact”- should be no void or air pockets
Describe the alignment of the PTB socket, what type of material is inside the socket, and any particular stability features
- Socket is aligned in approximately 5 degrees of knee flexion, which allows the bar to act as a weight bearing surface within the socket.
- (Gets its name from the use of a patellar “bar” that is built into the socket at the level of the center of the patellar ligament, midway between the patella dn the tibial tubercle)
- distal end of the socket with complaint foam material for WB- necessary to control distal edema
- medial and lateral walls extend up to level of adductor tubercle to provide level arm for ML stability
What looks like an interesting place to visit in Milledgevill, Georgia?
Old Governor’s Mansion
What is a big difference between the TSB socket and the PTB socket?
TSB socket tries to distribute the WB load over the entire surface of the limb (even places that have been traditionally thought as pressure intolerant). The PTB socket tries to distribute weight only to the tibial plateu and patellar tendon.
How does the Total Surface Bearing Socket work and what needs to be taken into consideration?
- strategic compression of soft tissue and relief of bony prominences- direct more force into area of the limb that can be tolerated
- force changes through gait cycle- dynamic pattern must be anticipated so as to use those forces to design the relief for pressure intolerant areas; large forces= tissue compression which need more relief; need to consider density and structure of the tissue being compressed
- Flexible inner socket is often paired/part-of this socket? (totally confused about this - emailed Dr. Mincer to help me understand how the flexible inner socket fits in the grand scheme of sockets)
What is the usual skin interface material used in the TSB socket?
Gel liners are a key component of TSB sockets
- Gel liner could be worn directly against the skin
- “Liner liner” could be worn against the skin under the gel liner.
- True/False: gel liners can be worn against the skin
- True/False: gel liners are always worn one way
- True
- Gel liner could be worn directly against the skin
- False
- “Liner liner” could be worn against the skin under the gel liner
List four functions of the prosthetic sock.
- Help accommodate changes in volume of the residual limb (probably the most important)
- (provides the individual with a method to control socket fit)
- Help cushion the forces applied to the residual limb during ambulation
- shock absorption
- shear forces
- Wick moisture that might accumulate during wear away from the skin
- Some have silver fibers in the sock to enhance antimicrobial properties
“provides the individual with a method to control socket fit”
“provides shock absorption, decrease the shear forces on the limb, and wick away moisture”
How would a flexible inner socket function with a particular type of socket to provide weight distribution?
Additional Questions:
- What is it?
- Who is it useful for?
- Who is it not good for for?
Pretty confused about this question from the reading guide. Emailed Dr. Mincer about it.
Here is what I had about it before:
- Incarnation of PTB (patellar tendon-bearing) theory (direct weight bearing into specific areas of the limb and away from others).
- Made with material that stretches upon application of force. A rigid frame is built around the inner socket, corresponding to areas of the residual limb where weight bearing is desirable. (I think this is the particular type of socket she is asking about? a PTB socket?)
- Results in socket that flexes away from forces in non-pressure tolerant areas, but remains rigid in the force-tolerant areas.
- useful for a person with particular boney prominences and those with severe localized sensitivity
- not for- residual limbs with adherent scarring
- I think the picture is a type of flexible inner socket.
How does a locking liner work?
There is a small locking pin in the distal end of the gel liner that locks into the socket to suspend the prosthesis.
(as opposed to a “cusion liner” that has no pin)
Somewhere that looks nice to visit in Guyana
Kaieteur National Park
It has Kaieteur Falls, which is the world’s largest single-drop waterfall by volume (according to wikipedia)
What is a pylon?
In a endoskeletal prosthesis, it is the bar that connects the socket to the foot.
Like endoskeleton version of a shank
TransTib Prosthetics: What is a shank?
The part of a exoskeltal prosthesis that connects the socket to the foot.
Like the exoskeleton version of a pylon
(picture is of a corbon exoskeleton)
What is the Heel Effect?
If you raise the heel, the pylon or shank will follow
(because there is little to no movement at the ankle joint)
If you raise the toes, the pylon or shank will follow and rock posterior, but this is less common (but think about climbing a hill)
Picture is of an orthosis, but the effect is the same in this case. Pretend the orthosis has no joint (is a solid orthosis), and you get the idea.
Somewhere that looks interesting to visit in Portland, Maine
Portland Museum of Art
