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 4
pattern, with the proximal ex tent of the ap at the level of the humeral epicondyles and the distal extent 3 cm distal to the tip of the olecranon. C, The
anterior skin ap is elevated to show the lacer tus brosus and underlying f orearm musculature prior to d ivision. D, The exor-pronator mass is released
from the medial epicondyle and reected to e xpose the median nerve. E, The released brachial artery is shown. F, The released biceps, brachialis, and
collateral ligaments are shown. G, The completed elbow disarticulation is shown.
It is important to ensure that an
angulation osteotomy does not shorten total humeral length substantially
more than intended. For the osteotomy
to have maximal benefit, the starting
length of the humerus must extend to
the metaphyseal flare or farther (Fig-
ure 6). An anterior closing-wedge
osteotomy is preferred, with the distal
segment at least 5 cm in length. The use
of a contoured 3.5-mm reconstruction
plate at a 70° angle is preferred to the
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
252
Photographs showing a cadaver elbow disarticulation. A and B, Equal anterior and posterior skin aps are fashioned in a sh-mouth
original Marquardt technique because
the final desired angle of osteotomy
is easier to obtain and maintain when
a plate is used rather than a screw or
Kirschner wire (Figures 7 and 8).
and posterior skin flaps are made in a
fish-mouth fashion. The length of the
flaps should be half the diameter of the
brachium at that level. The condition
of the soft-tissue envelope will dictate
the final configuration of the skin and
Surgical Technique
As in an elbow disarticulation, a sterile tourniquet should be used on the
brachium if the humeral length allows. Beginning at the level of the intended bone resection, equal anterior
muscle flaps.
The brachial artery and the brachial
and cephalic veins are double ligated
using 2-0 silk suture. The smaller veins
and vessels can be ligated with clips or
ties. The major peripheral nerves should
Chapter 20: Elbow Disarticulation and Transhumeral Amputation: Surgical Management
Figure 5
elbow disarticulation.
Figure 6
long transhum eral amputation befo re an angulation osteotomy.
AP radiograph of a completed
Preoperative AP radiograph of a
be resected using gentle traction neurectomies. Nerve transfers can be considered for targeted muscle reinnervation,
either immediately (in a pristine wound
setting) or soon after the initial procedure, to improve future myoelectric
prosthetic control and reduce neuroma
15 -17
pain.
The muscles in the anterior compartment of the brachium should be
divided at least 2 cm distal to the intended bone resection level. The insertion of the triceps tendon is freed
from the olecranon; the triceps fascia
and muscle are preserved. The triceps
is mobilized proximal to the level of the
planned bone resection. Electrocautery
is used to score the periosteum circumferentially at the level of the planned
Figure 7
otomy with a 3.5-mm stainless steel reconstruction plate, which was bent to approximately 70°.
Note that the osteotomy was made at least 5 cm from the end of the residual humerus to allow
for an appropriate fulcrum for suspension of a prosthesis. B, Intraoperative photograph showing
completed xation of the osteotomy site with the reconstruction plate.
Figure 8
osteotomy.
bone resection. The bone is divided at
this level using a sagittal power saw or
Gigli manual saw. The bone ends are
smoothed with a rasp or saw. Myodesis
is done using two holes drilled into the
anterior cortex of the humerus with a
2.0-mm drill bit just proximal to the
level of the bone resection. Two No. 2
polyester nonabsorbable sutures are
used to bring the triceps anteriorly over
A, Intraoperative photograph showing provisional xation of a closing wedge oste-
AP (A) and lateral (B) radiographs showing a humerus after an angulation
the end of the residual humerus and secure it through the drill holes. A suture
anchor can be used as an alternative
(Figure 9). The anterior musculature
is secured to the fascia of the triceps
that was brought over the end of the
humerus, using size 0 polyglycolic-acid suture, thus securing the proximal
musculature and further padding any
remaining bony prominences.
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
253
Section 2: Upper Limb
Figure 9
after a transhumeral amputation. A metallic anchor in the distal humerus was used for
myodesis.
AP radiograph of a humerus
Before closure, the tourniquet is deflated, and meticulous hemostasis is
obtained. The skin flaps are trimmed,
and subcutaneous tissue is closed using
2-0 polyglycolic-acid suture and staples
or monofilament suture for the skin. A
bulky soft dressing is applied over the
distal humerus in a figure-of-8 fashion,
using a sterile, woven six-ply gauze bandage and elastic wrap, and is left in place
for 3 days. A drain is not routinely used
but can be considered for an amputation
within the zone of initial injury.
Rehabilitation
After an elbow disarticulation or transhumeral amputation, the use of an indwelling pain catheter is recommended
for control of postoperative pain. The
patient typically is hospitalized 2 to 3
days for pain control. The postoperative dressing is changed before discharge, and the staples or sutures are
removed at 2 weeks. At this point, a
formal stump shrinker is applied, and
by 4 weeks the patient is fitted with
the initial body-powered prosthesis. It
is critical for the initial fitting to take
place as soon as the condition of the soft
tissues allows. Wright et al10 and Robinson et al18 found a positive relationship
between early fitting and the patient’s
sustained use of a prosthesis. Patients
who underwent unilateral transhumeral
amputation were least likely to use a
prosthesis. During the early phases of
prosthetic fitting and rehabilitation, it
is critical for the patient to have both
social and peer support for dealing with
the loss of the limb.
19
Managing Complications
Infection and wound-related complications such as dehiscence and scar
sensitivity are the most common complications after definitive closure, and
they necessitate additional surgical
intervention. Many complications are
directly related to the amount of initial
traumatic contamination and energy impact on the soft tissue. The treatment for
a deep infection or abscess is débridement and irrigation. Wound dehiscence
or scar sensitivity can be managed by
revision primary closure or excision of
the painful scar, respectively.
A postoperative infection or wound
complication can occur after any surgical procedure, but phantom limb pain,
residual limb pain, neuroma pain, and
heterotopic ossification occur relatively
often in patients who have undergone
amputation. More than 50% of these patients are affected by phantom limb pain
at some point during the rehabilitation
process.11 Pain after upper limb amputation does not always impair functional
use of a prosthesis.
Discomfort while wearing a prosthesis is the most common reason for
reoperation to treat neuroma pain and
heterotopic ossification. Excessive pressure on sensitive neuromas or bony
prominence while the limb is in the
prosthetic socket may prevent the patient
from wearing or using the prosthesis.
Neuromas are inevitable after resection
of peripheral nerves, but thoughtful
4
traction neurectomy and possibly targeted muscle reinnervation can reduce
the risk of symptomatic neuromas.
16-20
Summary
The ultimate upper limb amputation
level usually is dictated by the initial
injury. In choosing a definitive amputation level, careful consideration must
be given to bone length and, more importantly, the condition of the soft-tissue
envelope. Modern prosthetic techniques
allow the patient to be fitted with a prosthesis at any humeral amputation level.
In most patients, maintaining the maxi
mal possible humeral length is desirable.
Maintaining the humeral epicondyles
allows rotational control at the elbow
disarticulation level and allows better
suspension of the prosthesis. The disadvantages of limited elbow component
options and an undesirable cosmetic appearance at the elbow disarticulation
level can be overcome through humeral
shortening. Another attractive option is
a distal humeral angulation osteotomy
that maintains the epicondyles. An amputation level at least 3 to 5 cm proximal
to the native elbow center of rotation increases the number of options for elbow
components and maintains the benefits
of the epicondyles.
Aside from infection, discomfort
related to prosthetic wear is the most
common reason for revision surgery after definitive amputation. Most causes
of uncomfortable prosthetic wear are related to suspension issues at the residual
limb–socket interface, leading to pain
from pressure spots. Painful scars, inadequately padded bony prominences, heterotopic ossification–related discomfort,
and neuromas are common. Although
humeral length is of paramount importance in surgical decision making,
the importance of adequate padding of
distal bone ends and appropriate peripheral nerve management, regardless
of the amputation level, should not be
overlooked in the interest of achieving
an optimal functional outcome.
-
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
254
Chapter 20: Elbow Disarticulation and Transhumeral Amputation: Surgical Management
References
1. Atroshi I, Rosberg HE: Epidemiology
of amputations and severe injuries of
the hand. Hand Clin 2001;17(3):343350, vii. Medline
2. Freeland AE, Psonak R: Traumatic
below-elbow amputations. Orthope-
dics 2007;30(2):120-126. Medline
3. Beltran MJ, Kirk KL, Hsu JR:
Minimally invasive shortening
humeral osteotomy to salvage a
through-elbow amputation. Mil Med
2010;175(9):693-696. Medline DOI
4. Tintle SM, Baechler MF, Nanos GP
III, Forsberg JA, Potter BK: Traumatic and trauma-related amputations: Part II. Upper extremity
and future directions. J Bone Joint
Surg Am 2010;92(18):2934-2945.
Medline DOI
5. Cleveland KB: Amputations of the
upper extremity, in Canale TS, Beaty
JH, eds: Campbell’s Operative Ortho-
paedics. Philadelphia, PA, Elsevier-Mosby, 2013, pp 662-664. DOI
6. Alekberov C, Karatosun V, Baran O,
Günal I: Lengthening of congenital
below-elbow amputation stumps
by the Ilizarov technique. J Bone
Joint Surg Br 2000;82(2):239-241.
Medline DOI
7. Baccarani A, Follmar KE, De Santis
G, et al: Free vascularized tissue
transfer to preserve upper extremity
amputation levels. Plast Reconstr Surg
2007;120(4):971-981. Medline DOI
8. Marquardt E, Ne G: e angulation
osteotomy of above-elbow stumps.
Clin Orthop Relat Res 1974;104:232-
238. Medline DOI
9. Schnur D, Meier RH III: Amputation
surgery. Phys Med Rehabil Clin N Am
2014;25(1):35-43. Medline DOI
10. Wright TW, Hagen AD, Wood MB:
Prosthetic usage in major upper extremity amputations. J Hand Surg Am
1995;20(4):619-622. Medline DOI
11. Tintle SM, Baechler MF, Nanos GP,
Forsberg JA, Potter BK: Reoperations
following combat-related upper-extremity amputations. J Bone Joint
Surg Am 2012;94(16):e1191-e1196.
Medline DOI
12. Hutchinson DT: e quest for the
bionic arm. J Am Acad Orthop Surg
2014;22(6):346-351. Medline DOI
13. Kung TA, Bueno RA, Alkhalefah
GK, Langhals NB, Urbanchek MG,
Cederna PS: Innovations in prosthetic interfaces for the upper extremity.
Plast Reconstr Surg 2013;132(6):1515-
1523. Medline DOI
14. González-Fernández M: Development of upper limb prostheses:
Current progress and areas for
growth. Arch Phys Med Rehabil
2014;95(6):1013-1014. Medline DOI
15. Cheesborough JE, Souza JM, Dumanian GA, Bueno RA Jr: Targeted
muscle reinnervation in the initial
management of traumatic upper extremity amputation injury. Hand (N
Y) 2014;9(2):253-257. Medline DOI
16. Souza JM, Cheesborough JE, Ko JH,
Cho MS, Kuiken TA, Dumanian
GA: Targeted muscle reinnervation:
A novel approach to postamputation neuroma pain. Clin Orthop
Relat Res 2014;472(10):2984-2990.
Medline DOI
17. Dumanian GA, Ko JH, O’Shaughnessy KD, Kim PS, Wilson CJ, Kuiken TA: Targeted reinnervation for
transhumeral amputees: Current surgical technique and update on results.
Plast Reconstr Surg 2009;124(3):863-
869. Medline DOI
18. Robinson KP, Andrews BG, Vitali M:
Immediate operative tting of upper
limb prosthesis at the time of amputation. Br J Surg 1975;62(8):634-637.
Medline DOI
19. Williams RM, Ehde DM, Smith DG,
Czerniecki JM, Homan AJ, Robinson LR: A two-year longitudinal
study of social support following amputation. Disabil Rehabil 20 04;26(14-
15):8 62-874. Medline DOI
20. Pet MA, Ko JH, Friedly JL, Mourad
PD, Smith DG: Does targeted
nerve implantation reduce neuroma pain in amputees? Clin Orthop
Relat Res 2014;472(10):2991-3001.
Medline DOI
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
255
Chapter 21
Elbow Disarticulation and Transhumeral
Amputation: Prosthetic Management and Design
Gerald E. Stark, MSEM, CPO/L, FAAOP
Abstract
e transhumeral prosthesis can present tting challenges for the prosthetist because of the
underlying musculoskeletal anatomy of the residual limb as well as the variety of components and control options. e prosthetist must also balance the functional expectations
of the prosthesis with the added goals associated with comfort and appearance. Oen,
alternative socket designs are necessary to meet the needs of the individual patient. A
clinical knowledge of loading characteristics, volumetric considerations, control options,
postoperative management, and the fabrication of the interface is necessary in developing
a comprehensive prosthetic care plan for a patient using a transhumeral prosthesis.
Keywords: above-elbow; amputation; arm prosthesis; dynamic
socket; elbow disarticulation; prosthetics; transhumeral
Introduction
The transhumeral socket interface presents several unique prosthetic challenges.1 As with other levels of prosthetic
interface design, it must provide adequate proximal musculoskeletal stability
while managing the distal volume of the
residual limb. These objectives must be
accomplished even though the transhumeral prosthesis is suspended from
a highly mobile proximal skeletal joint,
with its own weight distracting it distally. The triaxial stability and coupling
of the interface to the residual limb is
further influenced by the interaction of
the upper limb harness design and by
the choice of control system used. For
example, body-powered systems with
laterally mounted control cables may
inadvertently pull an interface into external rotation if the socket is loose or
does not have adequate posterior proximal support. In many instances, an
otherwise well-made interface may not
Mr. Stark or an immediate family member is an employee of Ottobock.
provide adequate comfort or suspension
if the harness does not fit well.
Similar to the transfemoral level
where the prosthetic socket is often
based on the volumetric containment of
the dynamically moving soft tissue, the
transhumeral level must also encompass
the tissue around the shaft of a humerus
that is generally too narrow to provide
the distal skeletal substructure needed
to fully stabilize and maintain the position of the prosthesis. As a result, both
actuation and external loads create force
couples within the socket that must be
anticipated and managed. In the sagittal
plane, the interface has the tendency to
be pulled into extension as loads on the
forearm cause the socket to rotate forward. This places additional localized
loads on the anterior distal area of the
limb. In the frontal plane, patients with
a high degree of glenohumeral abduction may experience increased lateraldistal loading if the arm is not properly
aligned. In the absence of adequate soft
tissue, these areas can be vulnerable
to painful socket pressures. However,
when managing patients with excessive
redundant tissue, management of the
soft tissue is equally important because
the rigid skeletal structures are deeper
and more difficult to load. The various
possible levels of transhumeral amputation provide additional challenges, with
longer amputations requiring accommodation of the humeral condyles, and
proximal-level amputations requiring
greater proximal loading.
The prosthetist may be further challenged by a lack of any widely accepted, consistent clinical protocols for
impression taking and modification
techniques. In many instances, because
of the relative rarity of transhumeral
amputations, the clinician has not had
sufficient experience to build a clinical
reference for managing these patients.
All of these factors make the transhumeral interface design more challenging to manage and may contribute to the
low prosthesis acceptance rate (range,
27% to 61%) in individuals treated by
practitioners unfamiliar with the transhumeral fitting level.
uting to prosthesis acceptance include
the amputation level, functional expectations, the comfort level and cosmetic
needs of the patient, and the available
peer and professional support.
other levels of upper limb involvement,
ultimate acceptance of prosthesis use by
transhumeral amputees is based on the
ability to achieve their desired functional goals within their comfort tolerance. It
is critical that prosthetists are aware of
2-5
Factors contrib-
3,6
As with
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
257
Section 2: Upper Limb
Figure 1
wearing a typical elbow disarticulation prosthesis with outside hinges.
Photograph of an individual
the process, components, concepts, and
expected outcome for each prosthesis to
ensure that their patients have the best
chance of success.
6
Related Amputation Types
Although this chapter focuses on the
prosthetic management of transhumeral
amputations, related amputations are
also briefly described. In certain instances of limb paralysis, such as a brachial plexus injury, patients may elect
transhumeral amputation and fusion
of the glenohumeral joint, with 20° abduction, 30° flexion, and 40° of internal
rotation.7 In this elective amputation,
all prosthetic elbow componentry can
be accommodated if the humerus is
amputated 100 mm (3.94 inches) from
the tip of the olecranon.
amputation offers a more functional
solution than a flail arm, the decision
to amputate is very difficult and must
be treated with great sensitivity because
it involves the removal of an arm that
appears normal.
An elbow disarticulation (throughelbow amputation) has several advantages, including maximizing the length
8,9
Although
Figure 2
length. A, Location of the cut lines on the humerus. B, Reduced length with removal of the bone
segment. (Reproduced from Daly WK: Elbow disarticulation and transhumeral amputation: Prosthetic management, in Smith DG, Michael JW, Bowker JH, eds: Atlas of Amputations and Limb De-
ciencies: Surgical, Prosthetic, and Rehabilitation Principles, ed 3. Rosemont, IL, American Academy of
Orthopaedic Surgeons, 2004, pp 243-249.)
of the mechanical lever arm, minimizing
disruption to soft tissues, providing a
load-tolerant distal end, and permitting
distal supracondylar suspension.
However, the major disadvantage is that
the prosthetic elbow center is ideally
located more proximal than the distal
end of the limb, necessitating the use of
elbow hinges that are laminated outside
of the interface rather than mounted beneath it as in a transhumeral presentation
(Figure 1). Cosmetically, this increases
the distal mediolateral dimension at the
elbow joint. Functionally, it restricts the
number of componentry options and
shortens the prosthetic forearm.
Elbow disarticulation is often used
in pediatric amputations because it reduces bony overgrowth by preserving
Illustrations of the de Luccia and Marino osteotomy procedure to reduce humeral
length discrepancy is not noticeable in
adulthood. This creates a load-tolerant
residual limb capable of self-suspension
10,11
at a transhumeral limb length.
Less frequently used variants of
transhumeral amputation have also
been described,
9,10,12,13
including an osteotomy procedure described by de Luccia
and Marino14 in which a bony section of
the diaphysis is removed to place the hu
meral epicondyles more proximally (Fig-
ure 2). In another variation, Marquardt
and Neff12 described an angulation osteotomy that fixes the distal humeral shaft
length at 45° (Figure 3). This procedure
is most often used to treat patients with
bilateral amputation or those desiring a
more secure coupling with the transhumeral interface.
9,10,13
the epiphyseal growth plates. As the
child ages, growth of the ipsilateral
humerus can be surgically restricted to
shorten the arm over time so that the
Soft-Tissue Considerations
Most transhumeral amputations involve
the use of anterior-posterior flaps for
-
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
258
Chapter 21: Elbow Disarticulation and Transhumeral Amputation: Prosthetic Management and Design
Figure 3
angulation achieved with an anterior closing
wedge osteotomy. (Reproduced with permission from Marquardt E, Ne G: The angulation
osteotomy of above elbow stumps. Clin Orthop
Relat Res 1974;104:232-238.)
Radiograph of a Marquardt
closure, with a myodesis of the biceps
and triceps muscles to the distal humerus to preserve stability and main
tain alignment.10 Additional myoplasty
is performed to preserve the soft-tissue
padding and muscular balance of the
residual limb. Myoplasty provides good
distal padding, but it may make it difficult for the patient to differentiate the
independent myoelectric signals during
initial training.
Although the muscle bellies of the
biceps and triceps are initially in the
original longitudinal position, there
is a tendency for them to migrate medially, which alters the position of the
electromyographic (EMG) sites as the
limb matures. It is important to recheck
and adjust EMG sites to maintain correct
positioning. If the muscle bellies release
from the myodesis or myoplasty, muscle bunching may occur, with the muscle belly migrating proximally during
contraction. This can create problems
Figure 4
dividual who was treated with an innervated
pectoralis transfer for the purpose of maintaining an active electromyographic control site
for a possible future myoelectrically controlled
prosthesis. (Reproduced from Andrew JT: Prosthetic principles, in Bowker JH, Michael JW, eds:
Atlas of Limb Prosthetics: Surgical, Prosthetic,
and Rehabilitation Principles, ed 2. St. Louis,
MO, Mosby-Year Book, 1992, pp 255-264.)
Clinical photograph of an in-
in volume management and the placement of myoelectrodes as the muscle
dynamically contracts. This internal
movement can also cause release of the
proximal seal within suction sockets,
-
which allows air to enter into the socket and eliminates the negative pressure
environment necessary for suspension.
Because most of the muscle structures are left intact, these concerns are
less common with elbow disarticulation.
However, some surgical reduction of
distal soft-tissue bulk may be preferred
because it allows the transverse geometry of the distal humerus to provide
greater suspension and rotational control. Excessive distal redundant tissue
can prevent a tight fit and impede control of the prosthesis.
8
Muscle transfers and targeted muscle reinnervation techniques can be
used to provide additional EMG sites
for external power activation. Transfer of an innervated latissimus dorsi, a
gracilis, or a pectoralis muscle can be
used to create useful EMG sites if none
are available
15 -17
(Figure 4). Targeted
muscle reinnervation repositions existing nerves to the remaining muscle
groups that have been separated. Some
patients who have undergone such procedures have achieved surprising levels
of control complexity in combination
with sophisticated pattern recognition
control systems.
18
Postoperative Prosthetic
Management
It is commonly accepted that early
prosthetic fitting results in greater acceptance of an upper limb prosthesis.
The 30 days after surgery are often referred to as the golden period for prosthetic fitting.19 It is thought that if fitting
occurs beyond this period, the patient
will have adapted to some degree, becoming reliant on unilateral activation
strategies.19 Early management of the
amputation results in volume reduction
and pain attenuation by enclosing the
residual limb in a more rigid dressing or
a flexible liner.20 Early prosthetic fitting
also may have a psychological benefit
because the patient can begin to incorporate the proprioception or kinesthetic
awareness of the prosthesis into his or
her body image.
Elastic shrinker socks or bandages can be used to initially shape and
reduce the distal soft-tissue volume.
Subsequently, a basic upper limb prosthesis can be constructed of endoskeletal componentry and attached to a rigid
dressing or preparatory socket to begin
training in prosthesis control. After the
shape and volume of the distal limb stabilize, a more definitive interface can be
made (Figure 5). As the limb undergoes
volumetric changes, the use of an adjustable harness will assist in maintaining
suspension.
During the postoperative phase,
the rehabilitation team should meet to
establish immediate, short-term, and
long-term goals.
prosthesis allows the patient to become
accustomed to the loading characteristics, control movements, weight, and
21,22
The preparatory
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
259
Section 2: Upper Limb
operation of a prosthesis.
21,22
The prosthetist should involve the patient and
his or her support group in all phases
of prosthesis development. The patient
who is informed about recommendations and who actively participates in
decisions regarding his or her prosthesis
will typically establish a greater sense
of ownership and dedication to the
process.
21,22
The value of immediate psychological counseling and peer visits during
the early postoperative phase should not
be underestimated because the upper
limb plays a vital role in function and
human social interaction. A peer who
Figure 5
immediate postoperative prosthesis, with a
frame constr ucted of berglass cast ing tape, an
adjustable cable length, a gure-of-8 harness,
and a split-housing dual-control cable system.
Photograph of a transhumeral
has experienced upper limb loss can
help the new amputee establish realistic expectations and prepare for future
challenges that may aid in long-term
prosthesis acceptance and use.
22
Transhumeral Interface
Considerations
Historically, transhumeral interfaces fit
rather loosely about the residual limb,
and heavy socks were used to increase
anatomic loading.21 After donning with
a thick sock, the residual limb was
simply pushed into the loose fitting
socket, and few anatomic characteristics or contours were considered.21
Subsequently, the half-and-half socket,
which is characterized by an open proximolateral deltoid area and the use of a
flexible band over the shoulder, offered
an improvement in musculoskeletal and
volumetric control.23 The integrated saddle design, described by McLaurin et
al24 in 1969, served as a forerunner to
more modern designs that use extended
deltopectoral and infraspinous wings to
help support the weight of the limb. The
above-elbow suction socket described
by Pentland and Wasileif25 suggested
that suction suspension could be used
to support the transhumeral limb and
minimize the need for extra harnessing.26 The Utah dynamic socket, described by Andrew,8 introduced several
fitting objectives based on the anatomy
of the transhumeral limb (Figure 6).
These principles are valuable, not only
for externally powered arms as originally proposed, but also for stability in
body-powered systems. Although other
authors have introduced design nuances, several common goals have persisted
in all of the design variations.
25-27
Prosthetic transhumeral interface fitting is influenced by the following six
factors: (1) the length of the humerus,
(2) the thickness and condition of the
subcutaneous skin, (3) the shape of
limb, (4) the condition of underlying
musculature and skeletal substructure,
(5) the load tolerance of the patient, and
(6) the range of motion of the glenohumeral and sternoclavicular joints.
8,9
The consideration of these attributes
helps formulate which features of the
interface design are emphasized to a
greater or lesser extent.
The length and condition of the
humerus, which acts as the functional
lever arm, determines the amount of
load that the patient can support, especially during glenohumeral flexion
Figure 6
sion controls rotational instability while minimizing harnessing. ML = mediolateral. (Reproduced from Andrew JT: Prosthetic principles, in Bowker
JH, Michael JW, eds: Atlas of Limb Prosthetics: Surgical, Prosthetic, and Rehabilitation Principles, ed 2. St. Louis, MO, Mosby-Year Book, 1992, pp 255-264.)
Atlas of Amputations and Limb Deciencies, Fourth Edition © 2016 American Academy of Orthopaedic Surgeons
260
Illustrations of the Utah Dynamic Socket. A, The socket improves comfort by providing a better t. B, Anteroposterior (AP) compres-
Chapter 21: Elbow Disarticulation and Transhumeral Amputation: Prosthetic Management and Design
Figure 7
B, Push-in socket design.
Photographs of patients wearing dierent socket designs. A, Pull-in socket design.
and abduction. The condition of the
cut end of the humerus is of particular
importance because it is the distal point
of contact in the interface. A suitable
amount of distal relief will allow comfortable loading of the more proximal
humeral shaft rather than the cut end.
In some instances, when humeral length
is short, bone-lengthening procedures
have been used to increase the available
gradient of loading.
As is the case with transfemoral designs, the transhumeral interface design
must be able to manage the distal volume of the interface while maintaining
an intimate proximal musculoskeletal
fit. The volume of the distal limb can be
evaluated for general compressibility and
firmness. The subcutaneous tissue and
overlying skin also can be assessed by
lightly pinching the tissue at the midhumeral level. These qualitative measures
can be used to determine the amount of
tension or circumferential reductions be
low the anatomic measure that are necessary for a pull-in–type socket design.
Typically, a greater amount of tension is
necessary if the distal limb has a greater
amount of compressibility and subcutaneous thickness.
A major consideration in the selection of the transhumeral interface design is the choice between a pull-in or
push-in design (Figure 7). Historically,
a push-in design has been used because
of its ease of construction and relatively
loose fit22 (Figure 8). The patient simply pushes the residual limb into the
interface after donning the harness in an
overhead sweater or lateral coat fashion.
This is possible because the interface
fits loosely over the limb with a thick
wool sock.22 Because the shape of the
residual limb is not intimately captured, a substantial amount of movement, termed bell clapping, is possible
within the interface. As a result, much
of the excursion and movement needed
for body-powered control is lost, especially with shorter residual limb lengths.
However, if the push-in interface design
is tightened excessively, the patient may
experience proximal “hammocking” in
which the tissue of the residual limb is
pushed proximally and gathers at the
top of the interface causing soft-tissue
tension and pain over the distal end.22
Push-in designs are popular with
shorter limb lengths in which the
-
volume of the distal tissue does not
need to be strictly managed. In addition, push-in designs are preferred
for elbow disarticulations when the
distal skeletal substructure allows for
comfortable insertion (there is not excessive redundant tissue) and distal
suspension alternatives are used. More
modern push-in designs or those with
a tighter fit typically use an evaporative
lubricant, such as a gel hand sanitizer
or water-based ultrasound gel, to allow
easier insertion.
Figure 8
with a transhumeral prosthesis with a push-in
interface d esign. Donning involves pushing th e
residual limb into the interface, usuall y with the
aid of a prosthetic sock. The interface must be
made loose to allow easy donning.
Photograph of an individual
With the advent of externally powered prostheses, a more intimate socket
fit was needed to gain a more consistent
position for the myoelectrodes over the
surface of the residual limb because
they detect muscle activity. The pull-in
design uses the suspension techniques
derived from transfemoral fitting in
which the residual limb, without an interface cushioning sock, is pulled into
a socket with a smaller circumference
than the anatomic limb (Figure 9). This
allows an intimate and consistent “skin
fit” that is necessary for myoelectric
control, as well as partial suction suspension when using an external suction
valve that is applied after donning. Another advantage of the pull-in design is
that physical movement of the residual
limb is well-captured, which allows for
lower proximal trim lines, greater axilla
comfort, and improved range of motion. For these reasons, some individuals who use body-powered prostheses
may also benefit from the use of pull-in
designs.
© 2016 American Academy of Orthopaedic Surgeons Atlas of Amputations and Limb Deciencies, Fourth Edition
261
Соседние файлы в папке Библиотека им академика М.И. Перельмана