A Prosthetic Guide to Comfort and Stability
Making the Right Decision
A prosthesis, whether it is transtibial (below the knee), transfemoral
(above the knee) or upper extremity, must have the proper
components to accommodate your needs or lifestyle. Many different
and technologically advanced components are available today.
However, components can not provide enhanced function if they
are not matched properly for your type of amputation or current
level of function. Technologically advanced components will
not function as intended, if you do not have the proper fit
or alignment. If you already have had a prosthesis or you
are being fit for the first time, it is essential that you
receive a thorough evaluation. This provides essential information
on your residual muscle strength, length of residual limb
(critical for choosing compatible componentry), and all other
details that help make a proper choice for you.
What to look for in a Prosthesis
When doing research on getting a new prosthesis, you may find that
it is difficult on determining why there are differences in price.
If you look at a finished prosthesis closely, you might not be
able to tell why one is more expensive. But if you knew what was
incorporated into each, and what function it provided you, you
might conclude that quality and added function might provide you
with a better and happier lifestyle. This is value. Most people
will invest a lot of time and research before buying a new automobile,
as they want what will suit them best. However many people forget
that their most important form of transportation is walking!
Comfort
Your prosthesis must be comfortable or else wearing it will be
a burden, or you might not wear it at all. Comfort comes from:
1) a proper mold 2) mold modifications (measured and anatomical
design of your plaster mold) 3) proper socket fabrication (the
socket is what the stump/residual limb fits into), which is the
final step of producing the socket from the final corrected mold.
The primary reasons for an uncomfortable socket fit are: a mold
incorrectly taken, incorrectly modified, or a combination of both.
Medio-lateral stability (side to side stability) is extremely
important in all socket fits. Without that stability you will
have a residual limb that moves from side to side in the socket,
causing discomfort and undermining function. In a lower extremity
prosthesis, this will adversely affect alignment of the prosthesis,
thereby resulting in a loss of stability.
Suspension
There are many different types of suspension designs. Suspension
is what holds the prosthesis onto the residual limb/stump (residual
limb is the modern term for stump, however many patients still
refer to their amputation as their stump). We specialize in locking-silicone
suction suspension. Our patients have had wonderful success with
it, both with lower and upper extremity amputations. It provides
great comfort, excellent locking suspension, and a great degree
of stability. However, the mold must be casted and modified correctly,
otherwise the results can be compromised. Whether for below the
knee, above the knee, or the upper extremity, locking-silicone
liners provide a very high degree of comfort, stability, and safety.
The locking-silicone suction liner is a component made of materials
such as silicone, thermoplastic elastomers, or urethane. They
need to be chosen carefully and properly for your needs and for
your skin.
Alignment and Gait
A prosthesis must be correctly aligned to produce a natural looking or what
we like to call a cosmetic gait. We have had patients come
to us with existing artificial limbs, and sometimes they are
very concerned about other people noticing that they wear
a prosthesis.
Many times we have heard the complaint, "I wish the leg looked more real, because sometimes people stare at me when I come walking down the street". Most of the time it is not really what the prosthesis looks like that is noticeable, but an "uncosmetic gait" that attracts attention to how one is walking. Uncosmetic gait can be due to improper alignment. Alignment is the proper angular relationship between the stump, socket , artificial foot, and for the above knee amputee of most importance is the alignment of the prosthetic knee. Prosthetic components must be precisely aligned. Proper alignment increases stability, comfort, function and endurance. For new wearers, a prosthesis may be properly aligned at the time they receive the device, but increased skill in walking and balance, routinely require alignment changes to accommodate the improved function.
Therefore, it is very important to have a prosthesis that allows these alignment changes, to maximize your function and stability, which will produce a more natural and cosmetic gait.
Materials - What is the Prosthesis made of?
If you look at two different finished artificial limbs, can you tell what
materials went into their fabrication? In particular the materials
of the prosthetic socket?
Just by looking it is impossible to tell, especially if the socket has a cosmetic finish with a pigment . One of the most advanced materials in socket fabrication today is carbon graphite. But all carbon graphites are not alike. Some are strictly unidirectional. Some are not high modulus graphite. These are the least expensive. We only use high modulus multi-directional carbon graphite, which is the strongest and best quality graphite.
Graphite sockets: The idea of making a carbon graphite socket is to provide the patient with a socket that is light in weight, thin in design, extremely strong and durable. Sockets made with inferior graphite and resin are not as strong or durable. Unfortunately we have seen too many new patients come in with graphite sockets that were too flexible where it needed to be rigid in its structure, and the socket cracked.
Cosmesis
When the artificial limb is completed, after you have gone through
trial fittings and final alignment, and final fit, the cosmetic
stage will begin. Not all patients want a cosmetic finish. Some
prefer a technological type look, where all the componentry is
exposed. Other factors might be that they participate in sports
and want the prosthesis to be as light in weight as possible.
But many people do want a cosmetic finish. There are many different
types of finishes to complete a prosthesis. One of the more popular
finishes is to apply a rubberized skin over the shaped prosthesis.
The color is carefully matched to the patients own preference.
Cosmetics are very personal, and something the patient can decide
upon after discussing all of the different options.
WARRANTY
ORTHO REHAB DESIGNS warrants its custom-made lower limb
prosthetics and orthotics to be free of material defects for a
period of 1 year from the date of final delivery. Ortho Rehab
Designs will replace any device whose structure is defective without
cost within the warranty period. Components are subject to the
warranty provided by the manufacturer of that component.
