Chapter 11 Prosthetics Flashcards
What is a Prosthesis?
it is an artificial device that replaces a missing body part, which may be lost through trauma, disease or a congenital disorder.
its aim is to restore the normal function of missing body parts
Why is availability of lower limb prostheses important?
1) Diabetes account for > 60% of lower limb amputations as diabetics loses nerve functions on the foot
When injured, the person does not realized and it leads to necrosis of the foot
What are the Types of Lower limb Amputations/Prostheses?
1) Transtibial (Below Knee)
2) Transfemoral (Above Knee)
3) Hip Disarticulation (Hemipelvectomy)
What are the basic components of Transtibial Prostheses?
1) Socket
2) Shank
3) Foot
What is the Socket Design that all Transtibial Prostheses needs?
Patellar Tendon Bearing Socket (PTB Socket)
What is the features of a PTB Socket?
1) Patellar Bar (the indentation at the patellar ligament)
2) Medial tibial flare (the protrusion of the lateral side of the socket)
What does the Patellar bar do?
it helps align the knee at ~ 5 degree flexion which allows the bar to act as a weight bearing surface and prevent discomfort
What does the Medial flare do?
It helps to bear the load of the body weight.
It also eliminates the pressure on sensitive areas of the limb such as the tibial and fibular remnants (shin bones)
What is a Shank?
1) a tube of aluminum alloy or titanium
2) attaches at the proximal end and the foot is attached to the distal end via an adapter
3) There is foam to match the amputee’s legs and a thin flesh colored polyester cover to make it look as real and possible
What is the most commonly used Prosthetic foot?
Solid Ankle Cushion Heel (SACH)
What is SACH?
1) it is a compressible covering material where the heel is made of flexible foam plastic which is softer than the rest of the foot
2) allows foot motion in all directions by compression of parts of foot
3) cushion heel can come with different degrees of compressibility depending on the patient
What is the Advantages of SACH foot? NLGQM
1) No moving parts
2) Little maintenance
3) Good appearance
4) Quiet when using
5) Manufacturability for different shoe heel height
What is the disadvantage of SACH foot?
Limited range of dorsiflexion and plantar flexion
What are the gait deviations of amputees from normal individuals?
1) The lack of ability to plantarflex at the end of the stance phase means that no power can be use to help push off, hence the foot has to lift off the ground sooner (shortening the actual length of the leg cause u never use the front part of the foot)
2) The tendency of them to have lateral bending of the trunk towards the supporting foot (because if the CG is farther from support side the body will fall down to the unsupported side)
What are the ideal features of Prosthesis?
1) It needs to have consideration for weight versus function and balance them out
2) A balance of features to reduce excessive stress, wear and tear and inefficient gait but also low cost
3) Meet the individual’s needs and goals
