Transfemoral Considerations Flashcards
1
Q
TF Amputation and Energy Expenditure
A
- weight of prosthesis
- quality or socket
- accuracy alignment prosthesis
- fucntional characteristics of the prosth components
- on average: TF AMPUTATION (double amount of energy when walking 1/2 as fast, they need more rest breaks, more encouragement)
*
2
Q
Biomechanics - Length/ROM
A
- ROM - arthritis in hip
- Length - hip flexion contractures
- surface area
- RL condition/Surgical techniques - myodesis/myoplasty
*
3
Q
Funding Complications with TF amputations
A
- Medicare K Levels
- prescription factors K level mediates knee and foot componentry
- other design criteria
4
Q
Quadrilateral Socket Design
A
MORE MEDIAL/LATERAL WIDTH - TOTAL CONTACT
Posterior wall and brim
- wall - flat, slants ant to provide initial flex 15 deg, countoured to hamstrings
- brim - horizontal parallel to floor, seat for ischial tuberosity
Medial Wall and Brim
- wall - relief channel ant.med for add long, high to prevent add roll, prevents medial mvmnt of limb in socket
- brim - same height as post brim SHOULD NOT press on pubic ramus
Anterior Wall
- 2.5 in higher than medial wall-counter pressure for post wall
- SCARPAS BULGE = maintains ischial tub on ishcial seat by providing counter pressure (scarpas triangle = satrorius, inguinal lig, add long)
Lateral Wall
- higher than ant, inclines medially as it goes distally, set in 10 deg adduction
Easier to DON/DOFF
5
Q
NOrmal Shape Normal Alignment NSNA
AKA Iscial Containment
A
- More Anterior/Posterior Width
- Ischial Tuberosity is contained w/in socket
- lateral wall is higher and contains greater trochanter
- Lateral wall set in 10-15 deg ADD
- made with laminate hard socket interface
- also known as: ischial containment, CAT CAM, Sabolich socket, Hanger Comfortflex
- some contain both ischium and ramus therefor creating a boney lock with the femur
- CAT CAM = flexible socket, harder don
- Sabolich = rot stab & side/side control, comfortable
- Hanger = contoured to lock the pubic ramus and ischium within socket, harder to don
6
Q
Endoskeleton Design Critera TF
A
- vast componentry options
- post fabircation adjustability
- light weight
- more anatomical/soft/cosmetic with outer shell
7
Q
Exoskeleton Design TF
A
- traditional hard finish fabricated method
- durability/heavy
- limited componentry
- non-adjustable
8
Q
Suction Pull-In Suspension for TF
A
- Best primary suspension if possible
- provides greatest feedback - no sock is worn
- DIFFICULT TO DON
- Not indicated for individuals with:
- fluctuating volume
- heart conditions
- balance problems
9
Q
Roll on Suspension Liner
A
- shuttle lock or pin system
- lanyard system - cord pulls residual limb into socket and then attaches to external aspect of socket
- cushion liner - with air expulsive valve - sometimes vaccumm suspension
10
Q
Suction: Roll on silicone liner with shuttle cock and lanyard
A
- liners now being used for TF applications
- used with pts who have difficulty donning a traditional suction suspension
- extra guidance needed to get pin in shuttle
- lanyard used to solve this problem
- HAND DEXTERITY is important
- makes socket longer than normal
11
Q
Suction: Roll on Seal in Liner
A
- provides a suction socket
- easier to don than traditional true suction
- relatively new and have had good results
- has an air expulsion valve in socket to create negative pressure
12
Q
suction: roll on liner with coyote summit suspension
A
- relatively new
- prevents rotation in the socket**
- easy to apply
- works like a ski boot lock
13
Q
Silesian Band or Belt
A
- a webbing belt used as auxillary suspension
- does not control rotation in the socket
- simple
- made of cotton/dacron webbing
- relatively low profile
- DOES NOT CONTROL ROTATION WELL
14
Q
Total Elastic Suspension TES belt
A
- Another type of auxillary suspension
- very simple to use
- sort of bulky
- Moderate rotation control
- prosthesis may telescope
15
Q
Osseointegration
A
Advantages
- less feling of weight
- more control of prosthesis
- no persperation, pain from socket
- easy don/doff
Disadvantages
- 2 surgeries req’d (fixed to skeleton, re-expose and implant fixture)
- long rehab period
- deep infection risk
- rejection - amp at higher level
16
Q
Knees - Axis
Single Axis
A
- simple
- low maintenance
- single speed
- swing phase control
- not appropriate for some one who does not have good muscular control of knee**
17
Q
Knees - Axis
PolyCentric
A
- multiple centers of rotation
- provides added stability during stance**
- indicated for anyone with especially long residual limbs as well as those with less hip extensor strength/control
18
Q
Knees - Swing Resistance
A
Constant Friction
- single speed ambulator K1 or K2
Fluid Resistance
- hydraulic or air
- variable speed ambulators K3 or K4
- permits swing phase that more closely simulates normal gait
- increased weight, higher maintenance and higher cost
- may be less responsive in cold weather
19
Q
Other Features of Knees
A
- extension assist = at terminal swing
- stance control = locked, friction brake activated, mechanical, hydraulic
- computer controlled
- rotator
- torque absorber
20
Q
Single Axis Constant Friction Knee
A
- uses weight activated friction brake
- restricts more flexion when wt is put on 15-20 deg of flexion
- for K1 or K2
- up to 220lbs
- comes in child size
21
Q
SNS Stance and Swing Control Knee
A
- provides increasing resistance to flexion as knee flexes more and more to prevent falling in stance
- in swing, as knee is flexed more than 20 deg the foot is lifted and the knee extends
22
Q
Computer Controlled Hydra Knee
(C-Leg)
A
- intelligent knee by endolite
- rheo knee
- controls resistance to flexion and extension
- does not provide acive flexion/ extension
23
Q
Rotator Knee
A
located proximal to knee joint
allow pt to sit with legs crossed
24
Q
Torque Absorber
A
may be specific unit on shank or integral with foot
absorbs torque and thereby decreases shear force at RL/Socket Interface
25
Q
TF and Foot Prosthesis
A
- K0 = Non Ambulator - no coverage
- K1 = Household ambulator
- SACH, Constant friction knee
- K2 = limited community ambulator
- flexible keel foot, constant friction knee
- K3 = unlimited community ambulator
- dynamic response foot, fluid friction knee
- K4 = high activity
- dynamic response foot, fluid friction knee
26
Q
Knee Disarticulation Designs
A
advantage:
- end bearing RL
- self suspending
- long lever arm
- less surgically traumatic
disadvantage:
- component limitations
- cosmetic concerns
27
Q
Transfemoral Biomechanics
A
- must provide ML stability of pelvis during mid stance on prosthetic side - lateral wall of socket ADD
- provide AP stability of prosthetic knee between heel contact and heel off
- socket aligned in flexion approx 5-10 deg of flexion
- knee joint posteiror to TKA line
- TKA line = trochanteric knee ankle
- TKA line - socket forward of knee, knee posterior to trochanter and ankle if drop a plumb line - causes extensor moment = stabilization during stance
28
Q
Hip Disarticulation Endoskeletal Prosthesis
A
- pts can walk unassisted but with noticable deviations
- suspension socket that encompasses the waist to contain LE for providing more support to the lower kinetic chain
- requires A LOT of gait training in order to learn proper method of hip, knee, ankle control
29
Q
Bilateral Amputees
A
- limbs shorter so easier to control
- begin to train with stubbies
- lowers COM
- makes it easier to learn - start getting control and balance for gait
