Mike's Lecture Flashcards
Most common place for a sore to develop on a transtibial amputee?
Anterior-Distal Tibia
What are the possible causes for a anterior-distal tibia sore in a transtibial amputee?
- Not enough socks (BIG ONE)
- pt wearing shoes with too high of a heel
- foot placed too posterior
- too much flexion in the socket
- heel of foot is too stiff
- posterior shelf is too shallow
- not enough relief int he socket
What are the 3 goals of post-op care?
- facilitate healing
- reduce edema
- prevent contractures
What is the purpose of the preparatory prosthesis?
- early ambulation
- shape of the residual limb
- cost effective
What are the most common components for a transtibial amputee?
- SACH foot
- Endoskeleton pylon
- PTB socket (with pelite insert)
- Suspension (waist belt/cuff strap, and suspension strap)
Transtibial: pressure TOLERANT areas?
- patella tendon
- medial tibial flare
- medial tibia
- pre-tibial muscles
- shaft of fibula
- gastroc (posteriorly)
Transtibial: pressure SENSITIVE areas?
- tibial tubercle
- tibial crest
- anterior-distal tibia
- fibular head
- peroneal nerve
- distal fibula
- HS tendons (posterior)
For a PTB socket, where does the posterior shelf have to be?
If PTB, then you need a counter-force in back - so posterior shelf has to be just above the patella tendon (pt might not like it - remember mike’s story)
For a total surface bearing socket, where does the posterior shelf have to be?
Total surface bearing posterior shelf can be below patella tendon, because it does not need a counter-force.
Components of a preparatory prosthesis?
- prosthetic socks
- socket suspension
- socket insert
- socket
- pylon
- foot
What contractures are you concerned about forming post-op?
hip flexion and abduction
- could be due to positioning in hospital or muscle imbalance of iliopsoas (hip flex)/HS(hip ext) or glut med (ABD)/gracillis,etc (ADD)
What does a pt’s limb weigh compared to prosthetic?
limb = 8-10 lbs prosthesthesis = 3-4 lbs
What is the duration of the prepatory stage?
- Generally 4-6 months
- When to move on: constant residual limb volume, pt wearing excessive socks –> then you need to consider socket replacement
What are the advantages and disadvantages of exoskeletal prosthesis for a transtibial amputee?
Advantages: - Durable - Lightweight - Cost effective Disadvantages: - Cosmesis - Not alignable - Limited component selection
What are the advantages and disadvantages of endoskeletal prosthesis for a transtibial amputee?
Advantages: - Cosmesis - Alignable - Component selection Disadvantages: - Cost - Durability - Weight
What are the possible socket selections for a transtibial amputee?
- Open end
- Patella Tendon Bearing
- Total Surface Bearing
- Knee joints and Thigh Lacer
What are the possible suspension techniques for a transtibial amputee?
- Waist belt
- Supracondylar Cuff
- Suspension Sleeve
- Supracondylar Wedge
- Suction Suspension
- Pin Suspension
- Sub-Atmospheric Suspension
What are 2 ways suction suspension can be achieved?
- Expulsion valve
2. Suspension sleeve
Sub-Atmospheric suction is created by > ___ kPa vacuum. What does this produce? How does this affect fluid refill?
52 kPa
- This produces a large constant suspension and eliminates pistoning.
- This pulls fluid down into limb and keeps it there, so pt does not have fluid refill at night. However, it can be dangerous, because it makes it possible for awater blister to form.
What are the possible socket liners for a transtibial amputee?
- Hard socket
- Pelite Liner
- Multidurometer
- Gel Liner
What are the possible foot selections for a transtibial amputee?
- SACH
- Single Axis
- Multiaxis
- Flexible Keel
- Energy Storing
What SACH stand for?
Solid Ankle Cushion Heel
What type of prosthetic foot is a SAFE foot? What doe sit stand for?
Flexible Keel
- Stationary Attachment Flexible Endoskeleton
What are some of examples of energy storing feet?
- Seattle Foot
- Carbon Copy II
- FlexWalk
- VSP
- Pathfinder (VSP)
- Flex Foot
What are the stages of prosthetic design?
- Patient Eval
- Impression Technique
- Positive Model Modification
- Socket Fabrication
- Alignment (3 stages)
What are the 3 alignment stages?
- Bench Alignment
- Static Alignment
- Dynamic Alignment
While forming the model how do you create pressure? Create a pocket?
Building up plaster = creates pressure
Shaving down plaster = creates socket
Are waist belts used often in suspension?
Not usually - Odds are we won’t see this, but in elderly pt you might.
Where is the strap on a supracondylar cuff located? what happens over the years that affect this?
- Above the patella
- You can have atrophy over medial femoral condyle over the years
Are you able to change socket designs if you use suspension sleeves?
Yes
What are 2 things that can negate suction suspension?
- Hole is suspension sleeve
- Suspension sleeve not 2-3 inches on thigh
- these both cause air to get in, which cancels out the suction
What is the biggest problems with pin suspension?
Pin allows prosthesis to rotate and pistoning can happen
What are 3 biomechanic objectives?
- Maximize the weight bearing surface
- Maintain M-L stability
- Encourage knee flexion throughout stance phase
How do you maximize the weight bearing surface?
P=F/A
- Increase surface area
The alignment of the prosthesis can have just as much effect on how the socket feels to the pt as the overall socket shape does?
TRUE
Where do you want foot compared to socket to induce a knee flexion moment?
posterior
You want to outset foot slightly to create genu varum?
FALSE - inset foot slightly
What is the prosthetic cause and amputee cause of: Medial Whip?
Prosthetic Cause - ER of knee - tight socket (constriction of glutes when firing) - mis-aligned toe break Amputee Cause - gait habit - socket not put on properly - ER of hip at toe-off/hip flex
What is the prosthetic cause and amputee cause of: Lateral Whip?
Prosthetic Cause - IR of knee - loose socket - mis-aligned toe break Amputee Cause - gait habit - socket not put on properly - IR of hip at toe-off/hip flex
What is the prosthetic cause and amputee cause of: Abducted Gait
Prosthetic Cause - Prosthesis is too long - Medial wall too high - Insufficient femoral stability - Induces medial whip Amputee Cause - Abduction contracture - Poor gait habit, pt insecure and desires wide base in belief it will increase stability
What is the prosthetic cause and amputee cause of: Circumducted Gait
Prosthetic Cause - Long prosthesis - Excessive knee friction - Excessive knee stability Amputee Cause - Lack of confidence in flexing knee - Abduction contraction - Weak hip flexors - Habit (using entire hip and pelvis to initiate gait)
What is the prosthetic cause and amputee cause of: Vaulting
Prosthetic Cause - Long prosthesis - Poor suspension - Excessive plantar flexion - Excessive knee resistance or stability Amputee Cause - Gait habit, fear of catching toe - Weak hip flexors on residual limb - Improper initiation of hip flexors on residual limb
What is the prosthetic cause and amputee cause of: Heel Rise
Prosthetic Cause - inadequate extension aid - insufficient knee friction - improper knee selection Amputee Cause - excessive use of hip flexors, to initiate swing phase, overpowering knee unit
What is the prosthetic cause and amputee cause of: Knee Instability
Prosthetic Cause - excessive dorsiflexion - knee aligned in unstablke position - insufficient socket flexion - mal-alignment Amputee Cause - weak hip extensors - hip flexion contracture
What is the prosthetic cause and amputee cause of: Uneven Timing (Short prosthetic step) - LESS COMMON
Prosthetic Cause - socket pain - weak extensor aid - unstable knee - excessive dorsiflexion - poor suspension Amputee Cause - patient insecurity - weak hip muscles - poor balance
What is the prosthetic cause and amputee cause of: Uneven Timing (Long prosthetic step) - MORE COMMON
Prosthetic Cause - excessive plantarflexion of foot - insufficient intiial socket flexion - long toe lever arm Amputee Cause - flexion contracture - patient insecurity - pain on sound side
What is the prosthetic cause and amputee cause of: Lateral Shift
Prosthetic Cause - prosthetic foot too far inset - excessive socket abduction Amputee Cause - weak hip abductors - narrow gait base
What is the prosthetic cause and amputee cause of: Lateral Trunk Bend
Prosthetic Cause - foot too far outset - ineffective lateral socket containment - high medial wall - aligned in abduction Amputee Cause - inadequate balance - abduction contracture - short residual limb - habit
What is the prosthetic cause and amputee cause of: Toe Drag
Prosthetic Cause - long prosthesis - excessive plantarflexion - excessive knee friction Amputee Cause - weak hip abductors on sound side - poor posture - poor gait habits
If a patient’s prosthesis is too long, what will you see/pt report?
- pt will report LBP
- pt will report they feel like they are walking up a hill
- Noticeable rise and drop of shoulder on effected side
- Reduced swing of the arm on the effected side, exaggerated swing with arm on sound side