Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_921_Библиотеки_им_академика_М_И_Перельмана
.pdf
Section 2: Upper Limb
Figure 24
both body -powered and myoelec tric prostheses. A, Both sys tems allow full elbow range of m otion
and retain forearm rotation. B, Elec tric hands provide greater grip f orce and a more natural appearance than voluntary-opening split hooks. This patient nds both sets of prostheses valuable and
can match the most appropriate design with a particular activity.
transradial and wrist disarticulation levels. For the blind bilateral transradial
amputee, sensation is required for function. In these patients, surgical intervention (such as a Krukenberg procedure
or a toe transfer to the forearm [Vilkki
procedure]) is indicated to produce a
limb with manipulative capabilities24
(Figure 25).
Photographs of a patient with bilateral wrist disarticulations who was tted with
useful dynamic positioning of the prosthesis in space25 (Figure 26). Surgical
lengthening using bone allograft, which
allows for improved function resulting
from a longer residual limb, has been
beneficial for managing short transhumeral amputations26 (Figu re 27).
As with a transradial prosthesis, independent donning of the transhumeral
prosthesis is a primary goal. Donning
Transhumeral Level
Body-powered systems appear to offer
the best results for the patient with a
bilateral transhumeral amputation.
However, electric terminal devices and
elbows provide greater forces and can be
worn on the nondominant side to complement the function of a dominant side
body-powered prosthesis. The ability to
easily and securely position the prosthesis in space becomes more critical as
physiologic joints are lost. Positive locking wrists and humeral rotators should
be considered for these patients. Because
of the loss of glenohumeral rotation in
the transhumeral prosthesis, it may be
beneficial for the surgeon to perform an
angulation osteotomy to enhance the
independence is almost always achieved
when body position control is used, but
it may be compromised when myoelectric control is used because of the
need for skin-to-electrode contact and
the difficulty in donning these systems.
In the experience of this chapter’s author, nearly all bilateral arm amputees
with one or both amputations at the
transhumeral level prefer a body-powered prosthesis on the transhumeral side
that incorporates a four-function forearm
set-up over myoelectric or other hybrid
control options. Nevertheless, electric
control of one or more components may
be advantageous for some individuals if
the requisite force and/or excursion for
body-powered control are unavailable.
Figure 25
transradial amputee who underwent a Krukenberg procedure on the left hand and a Vilkki
procedure on th e right hand. These procedures
provided the patient with sensate limbs with a
variety of gripping options.
Photograph of a b lind, bilateral
New suspension/control systems, such
as those with high consistency rubber
silicone suction sockets with myoelectric
interface capabilities4 and other electrically controlled input options under
development, may necessitate the incorporation of these newer technologies
into bilateral fitting practice if they offer
functional advantages for the user.
Shoulder Disarticulation
When fitting a patient with a bilateral
shoulder disarticulation, it is advisable
to start with as simple a prosthetic system as possible. Often, only the dominant side is fit initially. The complexity
of the control system should be kept to
a minimum, starting perhaps with only
an activated terminal device and elbow.
As the patient becomes familiar with the
use of the prosthesis, wrist function can
be added, followed by humeral rotation
and a locking shoulder joint. The prosthesis for the nondominant side can be
fitted after the user has gained confidence in using the dominant-side prosthesis. Complexity on the nondominant
side can be staged in a similar fashion as
used for the dominant-side prosthesis.
In general, the dominant-side prosthesis
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
312
Chapter 24: Bilateral Upper Limb Prostheses
Figure 26
al/shoulder disarticulation amputee who beneted from an angulation osteotomy on his
right limb that facilitates physiologic humeral
rotation, which improves rotational stability
and provides added positioning control of the
prosthesis.
Photograph of a transhumer-
of the bilateral pair is configured with
mechanical, cable-actuated components
(similar to the four-function set-up),
whereas the nondominant-side prosthesis incorporates either all-electric or
hybrid components to provide complementary functions.1 When possible, the
electric prosthesis should use dedicated
variable speed control of the prehensile
device, the wrist, and the elbow.
Summary
Successful rehabilitation of a patient
with a bilateral arm amputation is best
achieved with a team approach. Bilateral arm amputees, especially those with
high-level loss, will benefit greatly from
prosthetic intervention and other assistive technologies, including automobile
modification, communication devices,
self-care devices, and nonprosthetic
manipulation devices that serve to augment the functions of the user. Each bilateral arm amputee must be treated as
a unique individual. The needs, goals,
and desires of the individual should be
the focus of the rehabilitation team. The
fitting methods and philosophies presented in this chapter should serve only
as a guide for successful prosthetic rehabilitation. Variations to this approach
will be required based on the particular
unique presentation of the individual
being treated and his or her expressed
preferences for particular prosthetic
options.
Experience has shown that careful
attention to socket fitting, ease of use
of the control system, and minimized
prosthesis weight are critical aspects in
successful rehabilitation. Proven desirable features of a successful prosthesis
are comfort, aesthetics, feedback, donning independence, control reliability,
Figure 27
with bilateral transhumeral amputations who
underwent surgical bone lengthening with
allograft on his left limb to improve function
by providing a longer lever to allow better
prosthesis control and stability. A, Because the
patient had a very short left residual limb, he
was initially tted with a prosthesis only on his
dominant right side. Photographs show the left
limb after allograft transplantation (B) and a fter
tting with bilateral body-powered prostheses
(C).
Photographs of a patient
variable speed control, and locking
joints. Clinical fitting protocol is driven by the availability of contemporary
components and the control strategies
for their operation. As new components and control schemes emerge, they
should be objectively evaluated. New
possibilities should be explored in the
light of what is possible and should not
be limited by what has previously been
done. Despite the many shortcomings of
state-of-the-art arm prostheses, bilateral
amputees often make good use of these
tools as they strive to achieve functional
independence.
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
313
Section 2: Upper Limb
References
1. Uellendahl JE, Heckathorne CW:
Creative prosthetic solutions for the
person with bilateral upper extremity
amputations, in Atkins D, Meier R,
eds: Functional Restoration of Adults
and Children With Upper Extremity
Amputation. New York, NY, Demos
Medical Publishing, 2004, pp 225-237.
2. Uellendahl JE, Heelan JR: Prosthetic
management of the upper limb decient child, in Alexander M, Molnar
G, eds: Physical Medicine and Reha-
bilitation: State of the Art Reviews.
Philadelphia, PA, Hanley & Belfus,
2000; vol 14, no 2, p 232.
3. Malone JM, Fleming LL, Roberson J,
et al: Immediate, early, and late postsurgical management of upper-limb
amputation. J Rehabil Res Dev
1984;21(1):33-41. Medline
4. Uellendahl JE, Mandacina S, Ramdial
S: Custom silicone sockets for myoelectric prostheses. J Prosthet Orthot
2006;18(2):35-40. DOI
5. Billock JN: e Northwestern University supracondylar suspension technique for below elbow amputations.
Orthot Prosthet 1972;26(4):16 -23.
6. Sauter WF, Naumann S, Milner M: A
three-quarter type below-elbow socket for myoelectric prostheses. Prosthet
Orthot Int 1986;10(2):79-82. Medline
7. McLaurin CA, Sauter WF, Dolan
CM, Hartmann GR: Fabrication
procedures for the open-shoulder
above-elbow socket. Artif Limbs
1969;13(2):46-54. Medline
8. Bush G: Powered Upper Extremity
Prosthetics Programme: Above Elbow
Fittings. Hugh MacMillan Rehabilita-
tion Centre, Rehabilitation Engineering Department Annual Report.
1990;35-37.
9. Farnsworth T, Uellendahl J, Mikosz
MJ, Miller L, Petersen B: Shoulder region socket considerations. J Prosthet
Orthot 2008;20(3):93-106. DOI
10. Uellendahl JE: Upper extremity
myoelectric prosthetics. Phys Med
Rehabil Clin N Am 2000;11(3):639-
652. Medline
11. Uellendahl J, Heckathorne C: Prosthetic Component Control Schemes
for Bilateral Above-Elbow Prostheses.
Proceedings of the Myoelectric Control
Symposium, University of New Brunswick, 1993, pp 3-5.
12. Ivko JJ: Independence through
humeral rotation in the conventional transhumeral prosthetic design.
J Prosthet Orthot 1999;11(1):20-22.
DOI
13. Heckathorne CW: Manipulation
in unstructured environments: Extended physiological proprioception,
position control, and arm prostheses. Proceedings of the International
Conference on Rehabilitation Robotics.
Piscataway, NJ, Institute of Electrical
and Electronic Engineers, 1990,
pp 25-40.
14. Childress DS: Control of limb
prostheses, in Bowker JH, Michael
JW, eds: Atlas of Limb Prosthetics:
Surgical, Prosthetic, and Rehabilitation Principles. St. Louis, Mosby-Year
Book, 1992, pp 175-198.
15. Simpson DC: e choice of control
system for the multi-movement
prosthesis: Extended physiological
proprioception, in Herberts P, et al,
eds: e Control of Upper Extremity
Prostheses and Orthoses. Springeld,
IL, Charles C omas Publishers,
1974, pp 146-150.
16. Doubler JA, Childress DS: Design and
evaluation of a prosthesis control system based on the concept of extended
physiological proprioception. J Reha-
bil Res Dev 1984;21(1):19-31. Medline
17. Heckathorne C, Childress D, Grahn
E, Strysik J, Uellendahl J: E.P.P. control of an electric hand by exteriorized
forearm tendons. Proceedings of the
Eighth World Congress of the International Society for Prosthetics and
Orthotics, Brussels, Belgium, ISPO,
1995, p 101.
18. Heckathorne CW, Uellendahl J, Childress DS: Application of a force-actuated position-servo controller 8
for electric elbows. Proceedings of the
Seventh World Congress of the International Society for Prosthetics and
Orthotics. Brussels, Belgium, ISPO,
1992, p 315.
19. Carlson L, Veatch B, Frey D: Eciency of prosthetic cable and housing.
J Prosthet Orthot 1995;7(3):96-99. DOI
20. Kuiken TA, Li G, Lock BA, et al:
Targeted muscle reinnervation for
real-time myoelectric control of
multifunction articial arms. JAMA
2009;301(6):619-628. Medline DOI
21. Kuiken TA, Dumanian GA, Lipschutz
RD, Miller LA, Stubbleeld KA: e
use of targeted muscle reinnervation
for improved myoelectric prosthesis
control in a bilateral shoulder disarticulation amputee. Prosthet Orthot
Int 2004;28(3):245-253. Medline
22. Hudgins B, Parker P, Scott RN: A
new strategy for multifunction myoelectric control. IEEE Trans Biomed
Eng 1993;40(1):82-94. Medline DOI
23. Simon AM, Lock BA, Stubbleeld
KA: Patient training for functional
use of pattern recognition-controlled prostheses. J Prosthet Orthot
2012;24(2):56-64. Medline DOI
24. Vilkki SK: Free toe transfer to the
forearm stump following wrist
amputation: A current alternative to
the Krukenberg operation]. Handchir
Mikrochir Plast Chir 1985;17(2):92-97.
Medline
25. Marquardt E, Ne G: e angulation
osteotomy of above-elbow stumps.
Clin Orthop Relat Res 1974;104:232-
238. Medline DOI
26. Wilkins RM, Brown WC: Allogra
transplantation to lengthen trans-humeral amputation limbs. Confer-
ence Proceedings of the 12th World
Congress of International Society for
Prosthetics and Orthotics. Brussels,
Belgium, ISPO, 2007, p 310.
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
314
Chapter 25
Upper Limb Provisional Prostheses
Chris Lake, L/CPO, FAAOP
Abstract
Although it is not a new concept, the regular and thoughtful use of provisional prostheses
(also described as trial and preparatory prostheses) can enhance meaningful prosthetic
use, reduce the likelihood of rejection, and place the individual with an upper limb amputation in the center of the prosthetic care model. e information gleaned from the tting
stage presents a clearer prediction of the eventual prosthetic outcome. e expanding and
increasingly complex choices of prosthetic components coupled with the increased desire by
third-party payers for assurances that the recommended course of treatment will be successful
have made provisional ttings increasingly more important. e provisional tting can
form the basis for a case-specic outcome-based protocol that will provide that evidence.
Keywords: improved clinical upper limb prosthetic outcomes;
preparatory upper limb prosthesis; provisional prosthesis; trial upper
limb prosthesis; upper limb amputee
Introduction
Powerful clinical tools are available to
the prosthetist. Although it is not a new
concept, regular and thoughtful use of
one of these tools–provisional prostheses–can enhance meaningful use
of prosthetic devices, reduce the likelihood of rejection, and place the individual with an upper limb amputation in
the center of the care model. The fitting
stages of the provisional prosthesis allow
the prosthetist to verify that the correct
course of treatment is being pursued to
provide optimal care for a given patient.
The information gleaned through these
processes creates a clearer prediction of
the eventual prosthetic outcome.
Terminology
The term provisional prosthesis has
variable applications. In some instances, it is synonymous with a preparatory prosthesis, a prosthesis designed
to withstand early prosthetic endeavors
Mr. Lake serves as an unpaid consultant to Innite Biomedical Technologies, Liberating Technologies, Ottobock, Ripple, and ToughWare Prosthetics.
for an extended period of time while allowing the prosthetist to closely monitor
the maturation process of the residual
limb.1 In this preparatory phase, a provisional prosthesis allows verification
and fine-tuning of prosthetic recommendations and increases the likelihood of a successful outcome through
a patient-centered approach, consistent
prosthetic attention, and adaptations to
long-term residual limb response that
can result in a better and more comfortable fit.
Alternatively, the same term can be
applied to a trial prosthesis, which is
intended to allow testing of the performance, qualities, and/or suitability of a
specific prosthetic design and/or component for an individual with a legacy
upper limb amputation.2 In this application, a provisional prosthesis used in
the early stages of a new course of prosthetic management can provide casespecific evidence to support or dispute
a particular prosthetic recommendation and can be a strong predictor of
longer-term outcomes. The information
provided can help members of the rehabilitation team, including the referring
physician, prosthetist, and therapist, to
meaningfully and productively adjust
the course of prosthetic management at
an early point in the process.
Whether used during the early preparatory phase of prosthetic rehabilitation or as a diagnostic trial device when
exploring a new prosthetic design variation, provisional prostheses determine
an individual’s general candidacy for a
definitive upper limb prosthesis, serve
as case-specific evidence to evaluate
prosthetic recommendations, and provide evidence-based support to justify
third-party payer authorization of the
expenses associated with definitive
prosthetic care.
Rationale
The use of provisional prostheses in
lower limb prosthetic management dates
back to the 1930s.3 In contrast, the use
of upper limb provisional prostheses is
more recent, with the bulk of the literature emerging in the late 1980s and early 1990s.
of upper limb prostheses is challenging,
requiring an analysis of the suitability of
the device in vocational requirements,
avocational interests, familial relationships, and basic activities of daily living.
The elements of a satisfactory outcome
are unique for every individual and depend on attaining a complex array of
upper limb functions and appearances.
As such, a thorough assessment of the
prosthesis may require usage outside of
the prosthetic facility in the user’s native
1,2,4
The functional assessment
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
315
Section 2: Upper Limb
Tab le 1
environment. Provisional prostheses facilitate this type of assessment.
the quality of upper limb prosthetic
care by helping to generate objective
and quantifiable information that leads
to case-specific, evidence-based recommendations.5 A trial fitting is a practical alternative in assessing intangible
Critical Elements of Patient-centered Upper Limb Prosthetic Care
Element Considerations
Fitting the prosthesis The prosthesis is ne-tuned throughout the process. The
Follow-up care This care is performed at least weekly throughout the
Repair and maintenance During the provisional phase, routine prosthesis main-
Information acquisition/
training
Information provided During the provisional phase, the patient is provided with
Use of multiple
prostheses
Setting the level of
patient expectations
Providing profes sional
knowledge and
experience
denitive device is not delivered until optimal socket
interface, component selection, and alignment have
been determined.
process. The patient is a key collaborator and learns to
identify events and sensations that signal the need for
evaluation. Progress is assessed during follow-up care,
and prosthetic recommendations may be modied or
completely changed.
tenance and repair can be discussed. For example, the
patient may learn how to lubricate and clean a terminal
device.
The occupational therapy aspect of provisional manage-
ment provides the patient with the opportunity to train
on the use of new devices as they are delivered and to
identify and treat both sound and aected limb issues as
they occur.
information on prosthetic technology and the available
prosthetic options. Rejection of a prosthesis is less likely
if the patient has the opportunity to assess dierent
types of components, designs, and socket interfaces
throughout the process.
Provisional ttings allow the use of multiple prosthetic
options so that the patient can assess and determine
which prosthesis, terminal device, and/or design is best
suited to specic activities.
A patient may have unrealistic expectations regarding an
upper limb prosthesis. The provisional management
phase allows the clinician to continually assess and set
realistic expectations. The prosthetics course can be
adjusted to accommodate feasible expectations, and
a psychologist and/or counselors can help the patient
cope with unrealistic prosthetic goals.
The prosthetist and therapist should have a good, com-
prehensive knowledge of all the elements of prosthetic
management. Continued training and education on
related topics will allow the healthcare team to provide
the patient with the best available prosthetic options
and adjust the provisional management phase as
needed.
variables such as patient motivation,
body image, and expectations. Mea-
Provisional prostheses can improve
surable criteria, including skin condition, weight tolerance, upper limb
strength, and the signal strength of
targeted remnant muscles, also can be
assessed. These and other variables are
better assessed when the user/patient
can actually experience the benefits and
drawbacks of a prosthesis rather than
speculating about its value.4 Provisional
fittings can help determine the optimal
prosthetic solutions for an individual
amputee through the assessment of various components. As the residual limb
matures, the transparent socket-frame
interface of a provisional fitting gives
clinicians a clear view of the evolving
dynamics of the limb-prosthesis interface; thus, meaningful and effective
adjustments are easier to accomplish at
an earlier stage.2 Planning and fitting
a provisional prosthesis also make the
user the focus of a patient-centered approach, with his or her values and needs
integrated into the process
6-9
(Table 1).
The likelihood of clinical success increases when users are actively involved
in decision-making processes.10 Meier
and Atkins11 emphasized the necessity
of allowing amputees to make decisions
regarding their lives and needs.
Clinical Application
Although the early course of provisional
prosthetic care focuses on determining
the general candidacy of the patient for
upper limb prosthetic management,
subsequent adjustments and prostheses focus on ensuring continued success
while carefully monitoring the patient
as his or her residual limb matures
and/or responds to prosthetic care.
During these processes, patients are able
to evaluate and determine the most appropriate components to address their
specific needs. In addition, the prosthetist can address the immediate softtissue response as edema subsides in the
residual limb. As usage continues, the
customary long-term tissue response of
overall residual limb atrophy with regional muscle hypertrophy and global
edema reduction may require repeated
adjustments of the prosthesis to allow
uninterrupted function. Electrodes, for
example, may need to be relocated as the
remnant muscles become more conditioned to prosthetic use. Similarly, adjustments to the prosthetic suspension
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
316
Chapter 25: Upper Limb Provisional Prostheses
Figure 1
prosthesis with exible inner sockets and berglass casting tape frames. Heavy-duty mailing
tubes help provide support for the casting
process.
Photograph of a provisional
system are frequently indicated. The
adaptable design considerations that
characterize these fittings reduce the lag
time between fit issues and appropriate
adjustments. This creates a state of flow
between the patient and the clinician
and can engender energy and excitement about the gains being made while
fostering a deeper patient commitment
to the prosthetic course of treatment.
Fitting and Component
Considerations
The components used for provisional
prostheses are generally the same as
those used in definitive prosthetic management. In trial applications, some of
these components may be rented (for
long-term assessment) or loaned (for
short-term or in-office trials) from
various manufacturers. In preparatory
applications, components are generally
definitively obtained. Most importantly,
a provisional prosthesis must be adjustable so that the clinician can keep
pace with the changes of the dynamic
residual limb. Thus, provisional and
definitive prostheses may differ in construction techniques and preparation of
components.
Figure 2
use require transparent thermoplastics. Inner sockets and outer frames can be fabricated with traditional fabrication procedures. Photograph of a transparent provisional prosthesis.
Given the expeditious nature of provisional fittings, the use of flexible thermoplastics for inner sockets is generally
preferred. For temporary applications,
alignment can be approximated using
The need for visual inspection associated with provisional prostheses for long-term
positive model throughout the fabrication process is questionable, a bivalve
thermoplastic duplication should be
made, preferably of clear check socket
material (Figure 5).
heavy-duty cardboard tubing, which
is then covered by fiberglass casting
tape (Figure 1). The patient’s skin and
surroundings are protected from the
rough finish of the fiberglass by applying a self-adhering, thin, elastic support
wrap to the outside of the provisional
device. Fiberglass casting tape usually
suffices for trial frames because of the
expected short-term duration of use. In
contrast, some provisional prostheses
need to provide long-term ease in adjustment and inspection. For this role,
transparent thermoplastic is a better
Alignment and Residual
Limb Considerations
Provisional fittings have many benefits,
with alignment of the prosthesis and re-
sidual limb response being the most ev-
ident. Alignment includes not only the
angle at which a terminal device or other
components are oriented in relationship
to the socket but also the placement of
the components and features through-
out the prosthetic space. Alignment and
residual limb considerations are relevant
in all types of prostheses.
frame material (Figure 2).
Provisional prostheses should be easily adjustable without affecting the continuity of prosthetic usage. The socket
interfaces and frames should be adjusted
and/or re-formed on site so the patient
has continued access to prosthesis use.
This is accomplished by forming inner
sockets from materials that can be reformed on modified models (Figure 3).
When necessary, frames and some inner sockets can be drape molded with a
nonadhering seam that allows them to
be spread open on the model for easy
removal and reapplication (Figure 4).
This technique also maintains the original model of the socket interface and/
or frame so the clinician can go back to
the original model and make changes
as appropriate. If preservation of the
Passive Prostheses
The provisional passive prosthesis helps
define the placement and specifications
of component alignment as well as the
length of the prosthesis. Many times, an
individual who requests a passive prosthesis is sensitive to prosthetic weight.
With a provisional prosthesis, the length
and the alignment angle can be investigated and fine-tuned before definitive fabrication to provide the lightest
perceived weight. Also, the pronation/
supination angle can be more readily
defined. For individuals who will not
be using a friction- or flexible-type of
wrist unit, this particular rotational
alignment is critical. With a proper
pronation/ supination angle, the passive
prosthesis evolves from a device that is
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
317
Section 2: Upper Limb
Figure 3
modied is indicated by the circle. B, The positive model is reduced as appropriate. C, The test socket is placed back on the model and the rectied
area (circle) is inspected. D, The test socket is heated in the area that will be re-formed. Baby powder is sprinkled on the heated plastic to keep the
thermoforming nylon and vacuum bag from melting and/or sticking to the hot plastic. E, Thermoforming nylon is placed over the model and tied o
to inuence a vacuum over the entire model. F, A vacuum bag is placed over the positive model and tied o accordingly. G, The vacuum bag is pulled
on the model and the model is allowed to cool appropriately. H, The vacuum bag and nylon are removed and the modied area (circle) is inspected
to verify that the desired results have been achieved.
Photographs demonstrating remodeling of exible inner sockets. A, The test socket is placed on the positive model. The area to be
aesthetic in nature to one that is a functional assistive tool for the individual’s
sound-side arm.
Body-Powered Prostheses
The fitting of a provisional bodypowered prosthesis will allow evaluation of long-term tissue loading with
terminal device actuation. As an individual uses a body-powered prosthesis,
Figure 4
the protective lm remains on the material when heating, the material is not welded together.
Photograph of a f rame that can be spread op en on a model to allow eas y removal and reapplicati on.
Inner socket and frames can be drape molded with a nonadhering seam. Because
his or her residual limb will adapt to
these forces. As tissues in the middle
and proximal parts of the residual limb
begin to atrophy under loading, more
pressure will be realized at the distal
end. A translucent, provisional prosthesis allows observation and adjustment
of these tissue changes in a precise and
efficient manner.
This stage of prosthetic management
also permits a thorough investigation
of different cable routing methods and
reaction forces and helps to ensure
the most energy-efficient and biome-
Figure 5
sheets of clear check socket material around a positive model. Because the protective lm remains
on the material when heating, the two sections are removable and not welded together.
Photograph of a bivalve thermoplastic duplication made by thermoforming two
chanically stable transition to a definitive body-powered prosthesis. In
addition, the location and orientation of
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
318
mechanical release levers, such as those
encountered in quick-disconnect wrist
units and remote elbow and shoulder
locking mechanisms, can be refined to
the user’s preferences. Segment lengths
and mechanical joint positions and
alignments also can be experienced
and refined during the provisional stage.
Externally Powered
Provisional Prostheses
Provisional fitting of an externally
powered prosthesis provides benefits
in component selection, alignment,
and placement. These aspects set the
starting point for the functionality and
perceived weight of the prosthesis. An
extended course of use with a provisional prosthesis also allows the clinician to monitor the muscular changes
and soft-tissue responses in the residual
limb. The prosthetic socket acts as the
foundation of the prosthesis and can be
undermined by residual limb atrophy
and/or hypertrophic muscular response.
The dynamic residual limb by its nature requires continued adjustment of
the more static socket. The clinician
should expect this interplay between
the evolving human limb and the adjustable man-made interface to continue
for an extended time. For best results,
this intensive adjustment stage should
be maintained until the patient’s residual limb size has remained stable with
continued use of the prosthesis.
The clinician also should be observant of electrode positioning. As the residual limb matures with myoelectric
prosthesis use, the residual muscle becomes more toned, and optimal myosite
positioning can change. Over time, the
patient should become more adept at
maintaining myosignals, and the residual muscles will likely strengthen at
different rates. The patient should be
educated on how the prosthesis should
react so that he or she can identify myosite imbalance and the need for adjustments. Educating patients provides
them with confidence and a feeling of
Chapter 25: Upper Limb Provisional Prostheses
Figure 6
Photographs of t ask-specic upper lim b provisional (A) and deni tive (B) prostheses.
control. Along with electrode position
and contact, the location of any additional electrical switches can be refined
as needed. As with body-powered de
vices, segment lengths and mechanical
joint positions and alignments can be
experienced and refined during the provisional stage.
Hybrid Provisional Prostheses
The fitting of a provisional prosthesis
is of particular value with hybrid prostheses. Most hybrid prostheses combine
a body-powered elbow with an externally powered hand (and sometimes
an externally powered wrist); therefore, provisional fittings can offer several unique benefits. For example, the
clinician can make better decisions regarding placement of the battery and the
charging hardware. Placing this hardware proximal to the elbow will lower
the perceived weight of the prosthesis.
This perceived weight can be further
reduced by positioning the elbow joint
more proximally.
A provisional prosthesis also allows
patients to experience the nuances of
different component placements so they
-
can decide what is best for their particular circumstances. For example, placing
the elbow joint in a slightly more superior position than the anatomic elbow
joint on the sound side will usually result in more natural bilateral function
in a seated position. The carrying angle
of the elbow and flexion-extension angle of the prosthesis are also considered
during this phase.
Task-Specific Provisional
Prostheses
As the name implies, a task-specific provisional prosthesis has a very defined
design and provides the opportunity
to assess different designs for individualized tasks such as swimming, participating in specific sports (such as
basketball or golf), and customized
vocational applications. For example,
a task-specific provisional prosthesis was fabricated for a patient with a
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
319
Section 2: Upper Limb
Figure 7
or have a built-in adapter (third device from the left). The two devices on the lef t were used for the
patient in Figure 6. The Quick Disconnect Myo-Electric Wrist Adapter (Texas Assistive Devices) is
shown in the fore ground. These t ypes of adapters pe rmit assessment of multip le prosthetic options
through a common i nterface-fram e assembly, and they essentially allow a p rovisional prosthesis to
function as several separate devices.
partial hand amputation that entailed
resection of digits two, three, four, and
five at the proximal metacarpal region
and preservation of an intact thumb
with very limited motion (Figure 6).
To return to work as a tank fabricator,
the patient had to be capable of safely
handling large sheets of metal and operating hydraulic presses to shape the
metal. Through the defined provisional
stage, a prosthesis was created with a
quick- disconnect wrist that attached to
a voluntary opening hook with adjustable tension and a range of common and
job-specific tools (Figure 7). Although
the patient’s thumb had limited motion,
Photograph of terminal devices that can be used with a quick-disconnect adapter
sound-side influence, electromyographic strength and endurance, and weight
tolerance, cannot be accurately assessed
without the individual’s experience and
practical use of the recommended prosthetic designs.
Upper limb prosthetic management
can occur as a process with several
phases that allows assessments and
revisions to the recommended prosthetic course. Changes should be made
in provisional prostheses based on the
patient’s feedback and experiences to
ensure that the definitive prosthesis will
provide a good outcome that combines
comfort, ease of use, and function.
he was able to generate approximately
2 pounds of pinch force against a
well-positioned opposition post. This
feature allowed him to handle paperwork and perform other fine pinch tasks
in which his limited thumb force and
sensation were still beneficial.
Summary
An individual’s meaningful use of a
prosthesis can be enhanced with an accurately executed course of provisional
prosthetic management. Variables, in-
References
1. Supan TJ: Transparent preparatory prostheses for upper limb
amputations. Clin Prosthet Orthot
1987;11(1):45-48.
2. Sears HH, Andrew JT, Jacobsen SC:
Experience with the Utah arm, hand,
and terminal device, in Atkins DJ,
Meier RH III, eds: Comprehensive
Management of the Upper Limb
Amputee. New York, NY, Springer-
Verlag, 1989, pp 194-209. DOI
cluding patient motivation, body image,
3. Sullivan JE: e aer-care of amputation stumps. Surg Clin North Am
1938;18:433-440.
4. Sears HH: Approaches to prescription of body-powered and myoelectric prostheses. Phys Med Rehabil
Clin N Am 1991;2(2):361-371.
5. Brenner CD, Brenner JK: e use of
preparator y/evaluation/training prostheses in developing evidence-based
practice in upper limb prosthetics.
J Prosthet Orthot 2008;20(3):70-82.
DOI
6. Biddiss E, Chau T: Upper-limb
prosthetics: Critical factors in
device abandonment. Am J Phys
Med Rehabil 2007;86(12):977-987.
Medline DOI
7. Meier RH, Esquenazi A: Prosthetic
prescription, in Meier RH, Atkins DJ,
eds: Functional Restoration of Adults
and Children With Upper Extremity Amputation. New York, NY,
Demos Medical Publishing, 2004, pp
159-164.
8. Soltanian H, de Bese G, Beasley RW:
Passive hand prostheses. Hand Clin
2003;19(1):177-183. Medline DOI
9. Michael JW: Externally powered
prostheses for the adult transradial
and wrist disarticulation amputee, in
Meier RH, Atkins DJ, eds: Functional
Restoration of Adults and Children
With Upper Extremity Amputation.
New York, NY, Demos Medical Publishing, 2004, pp 187-197.
10. Meier RH, Esquenazi A: Rehabilitation planning for the upper extremity
amputee, in Meier RH, Atkins DJ,
eds: Functional Restoration of Adults
and Children With Upper Extremity
Amputation. New York, NY, Demos
Medical Publishing, 2004, pp 55-61.
11. Meier RH, Atkins DJ: Postoperative
and preprosthetic preparation, in
Meier RH, Atkins DJ, eds: Functional
Restoration of Adults and Children
With Upper Extremity Amputation.
New York, NY, Demos Medical Publishing, 2004, pp 135-138.
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
320
Chapter 26
Silicone Interface Options in Upper Limb Prostheses
Elaine N. Uellendahl, BA, CP
Abstract
High consistency rubber silicone as an upper limb socket material is benecial for use at all
amputation levels. is material increases comfort, provides auxiliary suspension through
suction, and improves range of motion because of its elasticity.
Keywords: high consistency rubber silicone; interface; prosthetic
socket; silicone
Introduction
Silicone is a synthetic chemical compound made from the commonly occurring element silicon. It has been used
as an interface material in prosthetic
sockets for the past several decades.
The material characteristics of silicone
are conducive to optimal outcomes, including its high tensile strength, low
compression set (ability to return to its
original shape after being compressed
for a period of time), and high tear resistance.1 Silicone offers good biocompatibility and is characterized as nontoxic
and biologically inert. In addition, silicone does not support bacterial or fungal growth.
In the field of prosthetics, the most
traditionally familiar use of silicone as
an interface material is the manufacture
of roll-on liners. Such liners are generally made using liquid silicone rubber.
Another type of silicone, high consistency rubber (HCR) silicone, is used as
a socket material.
Unique among materials routinely
used for prosthetic interfaces, silicone is
an elastic material that can be stretched
to several times its size and still return
to its original dimension. Elasticity
coupled with flexibility help improve
Ms. Uellendahl or an immediate family member is a paid employee of New Touch Prosthetics and
has stock or stock options held in New Touch Prosthetics.
1
range of motion and reduce edge pressure, resulting in greater comfort and
functionality for patients. This improves
functional outcomes by allowing a patient to wear his or her prosthesis for
longer periods and with greater comfort
and increased range of motion.
2
High Consistency
Rubber Silicone
Fabrication Processes and Variants
HCR silicone interfaces are made by
applying uncured silicone, a clay-like
material, to a dehydrated plaster model.
The HCR silicone is prepared by adding an appropriate percentage of catalyst
and/or inhibitor. Although HCR silicone
check sockets are typically unpigmented
and remain transparent for diagnostic
fittings, definitive sockets can have custom pigmentation to match the patient’s
skin or another desired color. A two-roll
mill is used to mix the ingredients and
make a sheet of silicone (Figure 1). The
thickness of the silicone is controlled
with the bite or spacing between the
rollers. Successive layers of silicone can
be added between sequential periods of
oven curing to create channels for wires,
to embed electrodes, or for the application of zippers. The shore, or hardness,
Figure 1
used to mix the components of silicone and
control the thickness.
of silicone can be used to vary the elasticity of a socket, with a midshore silicone most often used. Because silicone
interfaces that have lower, more elastic
shores do not retain their shape as well
as those with higher shores and have
decreased tear strength, silicone materials with lower shore measurements are
usually applied only in selected areas.
In addition to the comfort properties
of silicone, another crucial advantage of
the material is its versatility in design.
If the patient has a residual limb with
a bulbous distal end, a zipper can be
added in the silicone interface to aid in
donning and doffing the prosthesis.3
Anchors can be embedded to attach to
supportive frames or straps. The thickness of the silicone can be selectively
varied, and gel pads can be sandwiched
between layers of silicone to provide
additional padding and protection for
especially sensitive or scarred areas.
In an electronic prosthesis, necessary
Photograph of a two-roll mill
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
321
Соседние файлы в папке Библиотека им академика М.И. Перельмана