Silicone-Only
Suspension (SOS) with
Socket-Loc and the
Ring for the Lower
Limb
Louis J. Haberman, CPO
ABSTRACT
This article discusses the previous and
current uses of silicone liners with the
Silicone-Only Suspension (SOS) technique. This technique has been enhanced by the use of injection-molded
silicone liners, Socket-Loc (patent
pending), and the Ring. Previously reported problems with SOS included unwanted internal socket rotation and intermittent loss of suction suspension.
Socket-Loc and the Ring have eliminated these difficulties while retaining the
many advantages of the SOS technique.
Introduction
The search continues for the best method to attach human limb substitutes.
Prostheses by their nature are wholly
unnatural to the body. The single most
important element in integrating the
anomalous prosthesis with a person is
to offer a superior means of attachment.
Suction suspension has proven to be
the best vehicle for integrating a person
with a prosthesis (1). Traditional suction sockets provide excellent suspension but rely heavily upon significant
soft tissue compression and skin-to-plastic adherence. Suction sockets of
this variety at times will cause discomfort, skin irritation and/or skin breakdown.
Applying these systems is arduous.
Good balance, proprioception and upper-limb strength are required to use
them so suction sockets most often
have been reserved for younger adults.
However, it is unacceptable to preclude geriatric amputees, the largest
amputee group, as recipients of suction
technology.
If traditional suction socket technology were easier to manage, it undoubtedly would have much broader applications. The development of the Silicone-Only Suspension (SOS) system in
1991 was spurred by these limitations
and restrictions.
Haberman, Bedotto and Colodney
(2) suggested an alternative to traditional suction socket designs by using a
silicone liner as a protective blister on
the residuum prior to entering the suction socket (see Figure 1
, Figure 2
, and Figure 3
).
Nivea? cream was applied to the outer aspect of the liner and as a lubricant/
sealant.
This suction system had applications
beyond the "healthy" patient. Older,
less vibrant individuals were capable of
donning and doffing their SOS prostheses unassisted. The soft tissue was
neither torqued nor excessively compressed within the liner/socket. The silicone liner protected the residuum
from undesirable socket friction and/or
socket shear forces.
Two problems remained with the
SOS design in some instances despite
its many advantages and increased applicability: intermittent suction loss
and internal socket rotation.
This article will discuss the solutions
found for both problems. The revamped SOS technique, the author
suggests, offers wide applicability for
the transfemoral (above-knee), transtibial (below-knee), transhumeral
(above-elbow) and transradial (below-elbow) amputation levels.
SOS System ElementsInjection-Molded Silicone Liners
The earliest silicone liners were constructed of fabric impregnated with silicone (3). Earlier uses of the SOS technique employed this type of liner.
These liners remain in wide use today.
They are relatively inelastic, thin-walled and lack durability and squashiness. Injection-molded silicone liners, as
described by Koniuk (4), became commercially available to the practitioner in
1990 (see Figure 4
). The advantages of
these liners over the laminated versions
are profound in that they offer increased
flexibility, durability and variable thickness and squashiness.
Commercially purchased injection-molded silicone (IMS) liners improved the SOS technique's suction
suspension for transfemoral and upperlimb amputees. However, the IMS liners also permitted more frequent internal socket rotation. Both of these
changes were attributable to the fabric-free, very smooth finish characteristic
of IMS liners.
Of further concern was the tapered/
cone-shape indicative of prefabricated
IMS liners. The amputated limb is neither tapered nor cone shaped but rather
irregular and highly contoured. This disparity results in decreased uniformity of
liner thickness and uneven compression
that may compromise suction and cause
discomfort. Prefabricated IMS liners
also tend to bridge when rolled over the
proximal socket margin.
Custom Injection-Molded Silicone
Liners
Custom-fabricating IMS liners is costly
and labor intensive. The original, unmodified cast model is substantially reduced (10-20 percent circumferentially). A uniformly thick spacer is then
placed over the reduced model. Depending on the model's shape, a one-,
two- or three-piece mold is constructed
over the model and spacer, and keyed
to maintain all the elements in alignment (seeFigure 5
).
The mold, when cured, is removed,
and the spacer is discarded (see Figure
6
). The mold is reapplied over the
model and secured with alignment keys
(see Figure 7
). A uniform space now
exists between the outer model and the
inner mold due to the removal of the
spacer.
After much preparation, the liquid silicone is injected through the mold to fill
the void created by the eliminated spacer (see Figure 8
). Custom-fabricating
IMS liners to the patient's anatomical
shape maintains appropriate liner thickness and compression. Proximal bridging is eliminated by proper liner contouring. Excellent silicone suction also is
achieved with custom fabrication.
Despite these improvements, rotational instability and intermittent suction loss were still problems. An auxiliary waist belt suspension was considered and quickly abandoned. Such additional encumbrances, it was felt,
would diminish the adoption of this
technology. A self-contained solution
to rotational instability and suction loss
was found.
The Button, Version 1
Silicone's adhesive nature is advantageous because the material never rotates, shifts or displaces when properly
fit to the residuum. Assuming the IMS
liner functions as a relatively unyielding and stable component, it was modified to correct these deficiencies. A
projection or button contiguous with
the rest of the liner was added (see
Figure 9
). A corresponding hole was
added to the socket (see Figure 10
).
This modification of the original design
secured the IMS liner to the socket.
The interlocking connection provided a mechanical attachment between
the socket and liner that served as a
rotational stop and enhanced suspension (see Figure 11
). For lack of a better term, the author has chosen to call
this projection "The Button."
To create the Button, an additional
mold was designed and strategically installed onto the existing outer mold.
This mold extension fills with silicone
during the injection-molding process,
thus creating a continuous, one-piece
LMH Button Liner (patent pending).
The IMS Button Liner performed well
for approximately five months until
tearing was observed at the button base
(see Figure 12
). It was clear that the
unyielding, hard edges of the Surlyn ?
hole were responsible for the cleaving.
There also were problems with air escaping through the Button hole in the
suction socket. Reducing the hole diameter diminished but did not eliminate air passage through the aperture.
A protective device, easily installed
and constructed of a similar material,
was required to maintain the suction
seal and to ensure the continued integrity of the Button.
Socket-Loc, Version 1
Socket-Loc is a high-strength silicone
grommet that snaps into a predrilled
hole in the socket (see Figure 13
and
Figure 14
). The author suggests using Surlyn
or Sofalyn as the socket material although more flexible thermoplastics
may be employed. Post-molded shrinkage of Surlyn and Sofalyn, characteristic of thermoplastics, may actually facilitate a better-fitting socket. Optiflex? another socket thermoplastic,
is too flexible for this application unless
it is supported and stabilized with a
properly, designed frame. Optiflex also
will discolor from the Nivea? cream.
The IMS Button Liner meshes the
Socket-Loc during the donning process. The wearer must gently nudge the
Button into the aperture in Socket-Loc
using Nivea cream as a lubricant (see
Figure 15
and Figure 16
).
The silicone-to-silicone contact creates a complete air seal. The silicone
construction of Socket-Loc is firm yet
yields enough to prevent cleaving of
the Button. Once donned, the prosthesis will not rotate nor displace (even if
volumetric reduction of the limb occurs).
The wearer must learn to apply the
IMS Button Liner in a consistent manner. Placing the Button on the residuum is crucial to the proper orientation
of the prosthesis. An incorrectly applied IMS Button Liner must be reapplied to establish accurate prosthetic
rotation. The patient, in most cases,
will learn to don the liner with precision and dispatch within days.
The author determined the most logical placement of the Button to be approximately 2.5 cm to 5 cm (1 to 2 inches) anterior and 5 cm to 7.6 cm (2 to 3
inches) proximal to the greater trochanter (see Figure 17). The anatomic
area must be firm so that a constant
outwardly directed pressure will be applied to Socket-Loc. This area also
must be easily accessible to the patient
for manipulation of the Button into the
Socket-Loc aperture.
The aperture in the center of Socket Loc is for acceptance of the Button (see
Figure 18
). The Button, for all practical
purposes, can be placed anywhere on
the IMS liner the prosthetist chooses.
A template is employed for precisely
sizing the socket aperture for acceptance of Socket-Loc. Light sanding
around the aperture is required, and a
thin bead of Dow Corning #732 Silicone Adhesive must be applied inside
Socket-Loc's clevis prior to snapping in
place. The best bond is achieved with
an overnight cure.
The Ring
Usually after three to six months the
grommet's silicone seal fatigues due to
the intermittent stresses of donning
and doffing the Button and the continued stress of ambulation. The weakened seal permits air to pass between
the grommet and the socket wall. It
was recognized that a redesign of
Socket-Loc would be required.
Of more immediate concern was correcting the loss of suction suspension.
Based on the author's experience, Hypobaric systems design and Carl Casper's TEC? Liner (5), a Ring or band
of silicone was applied over the IMS
Button Liner then lubricated with Vas
eline? and placed into the socket. The
Ring maintained a positive seal. Air
still leaked around the grommet but
did not interfere with suction suspension. The Button remained for rotational stability. Subsequently, the Ring
was incorporated into the IMS Button
Liner (see Figure 19
). The best location
of the Ring was mid-limb for the transfemoral amputation level.
Ring depth became an important
consideration In all cases, the Ring
thickness is at least equal to, if not
greater than', 6 mm (1/4-inch). Flaccid
limbs require an increased Ring thickness of 10mm (3/8-inch) for appropriate
suction suspension while firmer residua
require 6 mm (1/4-inch) or less. Excessive thickness, in either limb type, will
compromise skin integrity at the level
of the Ring. Insufficient Ring depth
will not maintain the suction seal.
Ring width is fairly consistent at 4 cm
(1 9/16-inch). In some situations, the
Ring was placed in anatomically undercut regions and widened to enhance
socket and liner symmetry (see Figure
20
).
The Ring ensured suction suspension remained positive with or without
Socket-Loc. Socket-Loc was used only
for rotational stability.
The Button and Socket-Loc, Version 2
The first version of Socket-Loc (see
Figure 21
) had deficiencies that complicated the fitting process. The silicone
seal failed around the grommet, allowing air to compromise the suction suspension.
The fixed nature of the Socket-Loc
installation did not allow for variations
in donning the IMS Button Liner. For
example, the Button could assume various vertical heights on the residuum as
a consequence of the wearer's donning
technique. A vigorously applied IMS
Button Liner might achieve an end location 10 mm (3/8-inch) higher than the
Socket-Loc aperture. Also, manipulating the Button into the aperture was
difficult for several individuals. Although Socket-Loc Version 1 presented fitting difficulties, it did show that a
mechanical silicone stop would achieve
its desired result in maintaining rotational stability.
Socket-Loc Version 2 (hereafter
Socket-Loc) eliminated the aforementioned deficiencies of Socket-Loc Version 1 (see Figure 22
and Figure 23
). The Button was reconfigured from its inverted
cone shape into an inverted rectangle.
The rectangle assumed a vertical orientation on the IMS liner. The rectangle
had a 10-degree taper as it approached
its insertion into the IMS liner (see Figure 24
and Figure 25
).
A vertical channel or trough (hereafter Socket-Loc) is incorporated into
the socket to accept the new rectangular Button. Its position is determined
during the check socket fitting. The
check socket is applied over the IMS
Button Liner several times to establish
the location of the new rectangular
Button.
The Socket-Loc is made longer than
the Button. It extends beyond the Button, proximally and distally, approximately 13 mm (1/2-inch) (see Figure
26
). The extended Socket-Loc allows
for variations in donning technique
that often will place the Button in various vertical locations. The Button engages the Socket-Loc easily. Air loss
no longer occurs because the Socket-Loc is now a closed system since the
grommet and its aperture have been
eliminated.
The tapered Button and Socket-Loc
interlock with one another, much like
puzzle pieces. With these changes, the
Button and Socket-Loc Version 2 has
achieved its goal of providing a self-contained system that offers suction
suspension, rotational stability and
maximum protection of the residuum.
The Silicone
Dozens of silicones are available today
from several suppliers. When choosing
a silicone for manufacturing a prosthetic liner, make sure the silicone is of the
highest quality. Only platinum-based
curing silicones should be used for liner
fabrication. Medical grade silicones for
outer body use are unnecessary, according to many experts in the silicone
industry (6). Properly cured, high-quality (nonmedical) silicones will not,
in any way, be harmful to the patient.
There are silicones with properties that
range from the extremely soft to the extremely hard. For use in prosthetic liners, and particularly in the IMS Button
Liner, prosthetists should use a high tear
strength, high-grade silicone exhibiting
flexibility and high elasticity.
Many silicones were evaluated for
use in the IMS Button Liner. Most silicones lacked adequate tear strength
when they were appropriately soft and
flexible. Overly firm silicones were uncomfortable and difficult to don. Exceedingly thick (10 + mm or 3/8-inch)
liners, despite the material (silicone,
urethane), became uncomfortable for
some patients with complaints of
numbness or "pins and needles." The
silicone finally chosen for these prosthetic liners has met the aforementioned requirements and is now commercially available.'
The Valve
Standard thermoplastic suction valves
(push or pull) have performed adequately in the SOS system. As discussed in the previous article (2), an
autoexpulsion valve provided the most
safety and convenience. Initial performance with these valves was good,
but within weeks problems occurred
with variations in air flow. The valves,
it appears, were unable to maintain the
proper adjustment or would fail outright.
The author and a colleague (7) decided to design an autoexpulsion valve
(nonadjustable) to use with the SOS
system. Examining existing leak-rate
valve technology provided insight for a
new, reliable design. The Lyn Valve ?
(see Figure 27
) is preadjusted by patient weight so it was possible to give
the Lyn Valve a much more substantive spring and bladder than other adjustable leak-rate valves. Initially, consideration was given to designing three
weight classes:
- Size 1 120 lbs. and under
- Size 2 = 120 to 200 lbs.
- Size 3 = 200 lbs. or greater
All three valve types were produced
and evaluated. Clinical trials indicated
that the size 2 valve worked properly
for all three weight classes despite earlier assumption. The Lyn Valve 2 is
now the valve of choice for the SOS
system. This valve also has been used
with non-SOS suction systems with excellent results.
SOS with Socket-Loc for the
Transfemoral AmputeeProceduresImpression Procedure for IMS Button
Liner
The cast impression procedure for the
IMS Button Liner is in all respects
identical to the current standards of
practice employed by certified practitioners. Give special consideration to
extending the impression proximally.
This extension will allow for a higher-walled IMS Button Liner that can be
rolled over the socket brim for greater
comfort.
Fabrication of the IMS Button Liner
A great disadvantage of the SOS with
Socket-Loc is that it is not easily fabricated. The fabrication of the IMS Button Liner is laborious and costly. Extensive experience with injection-molding procedures is required. Special equipment and proper lab design
are helpful to the process, and the
proper silicone must be chosen for this
specific application.
Certainly, any practitioner may attempt this fabrication and probably
should do so, at some time, for this and
many other applications. For now,
however, the practitioner who is not
skilled in this process should order the
IMS Button Liner from the manufacturer. To make custom IMS Button
Liners, use the method described earlier in this article.
Double Casting
Over time, double casting has replaced
all other casting techniques for SOS
systems. This technique implies that
the cast impression (for the definitive
socket) is taken over the residuum and
the injection-molded liner (see Figure 28
). This has proven to be the best method for creating the most accurate impression.
Apply the IMS Button Liner, making certain the liner is snug and gap-free. The proximal liner is left long initially; if it interferes with cast-taking, trim the liner at 1-inch intervals until the interference is manageable. Let 2 inches of excess silicone remain proximally. Apply Saran Wrap over the injection mold or the IMS Button Liner.
Elastic plaster-of paris bandage is applied next. A small opening is retained at the most distal end of the plaster wrap to permit air to enter the cast impression for easier removal. Clean the liner with soap and water and replace onto the cast model while storing to prevent wrinkles.
On many occasions, the patient has retained the liner after the double-casting (impression) procedure to gently acclimate the pationent to compression and to protect the limb when it's not in a prosthesis. The liner also has been used as a mild shrinker during this
phase of fabrication.
Cast Modification
Much has been written about cast reductions for liners and sockets. Charts,
tables and other scientific measures
have been created to guide the prosthetist through the cast modification process (8). The author uses neither limb
measurements (excepting linear) nor
tables for cast modifications.
The cast model is the most accurate
patient measurement obtainable. It is
the truest reflection of the residuum
shape because it is made under containment, compression and traction.
The prosthetist's skill, clinical experience and artistic involvement are the
best methods available for proper cast
modification.
Using check sockets will allow prosthetists to explore and develop a greater awareness of their own artistry and
intuitiveness while ultimately providing patients with the best sockets available. (For those preferring actual numbers, see Figure 29
.)
Socket Fitting
Using clear check sockets is suggested.
These sockets may be draped or preferably, blister molded. A suction valve
should be installed to evaluate suction
suspension properly. Coat the outer aspect (Button side) of the liner with Nivea or Vaseline and turn inside-out to
apply. Roll on the IMS Button Liner,
making certain the liner is uniformly
snug. Orient the IMS Button Liner so
that it is placed 2.5 cm to 5 cm (1 to 2
inches) anterior to the trochanter. The
height of the Button already is determined.
The liner's proximal trimline is left
high; if it interferes with the application of the socket, trim the liner 2.5 cm
(1 inch) at a time and reapply the socket. It is suggested that no less than 5 cm
(2 inches) of silicone be retained proximally for adequate coverage and overlap of the socket trimline.
Initially, the socket may be donned
while seated. It is necessary to stand
and bear weight on the socket to full)
engage it and the liner. The Lyn Valve
will expel any remaining trapped air
without pushing the valve button. Be
sure the socket is properly oriented to
its configuration and the residuum. Do
not rotate the socket to place the Button at some preconceived location.
After the socket has been situated
properly, examine the Button location.
If it is too anterior/posterior, remove
the socket and liner and reapply the
liner in a more correct position.
Once liner and socket integration
has occurred, locate the Button (now
compressed) at the proximal lateral aspect of the socket. Draw an outline of
the Button with a permanent marker.
Cut through the outline with a cast saw.
Smooth and lightly polish the edges of
the rectangular opening. Reapply the
check socket, as before, but attempt to
guide
toward the opening. When the liner is
seated fully within the socket, the Button should be aligned with the hole and
gently nudged through it if necessary.
Next, determine if adequate suction
suspension is present. The SOS socket
with the Ring and Socket-Loc should
easily suspend loads exceeding 23 kg
(50 lbs.) (see Figure 30
). It may be unwise to test for these higher levels of
suspension capacity because loads of
this magnitude may cause joint or ligament injury.
Troubleshooting
Table 1
provides a list of fitting problems encountered and possible solutions found during the development
and evolution of this technique.
SOS with Socket-Lee for the Transtibial
Amputee
Preliminary work has begun to incorporate this technology into treatments
for the very large transtibial amputee
population. Many types of quality suspension systems exist for this level.
However, due to the successes of SOS
with Socket-Loc at other levels, it followed that this technology should be
made available for patient and prosthetist consideration.
A Socket-Loc smaller than the transfemoral had to be constructed. Initial
research indicates that two Socket-Locs
should be used. A high-walled, supracondylar socket is required for locating
and installing the Socket-Locs. The optimum locations for installation appear to
be the proximal posterior aspects of the
medial and lateral condyles.
The Lyn Valve or Pee Wee Valve
(see Figure 31
) is placed at a convenient medial distal location. Nivea
cream is applied to the external aspect
of the liner to facilitate donning and
enhance the suction seal. No Pelite
or similar liner is present. As is always
the case with SOS, the residuum is protected from the unpleasantness of the
socket and the negative atmosphere.
Of greatest concern are the more
pronounced volumetric fluctuations of
the residuum common to transtibial
amputees. Significant volumetric reductions would result in suction loss
and improper limb retention within the
socket. Suspension is still retained as a
consequence of Socket-Loc. However,
limb penetration and end-bearing complicate the use of this technology because there is no Pelite insert to modify, and adding socks would result in the
complete loss of suction suspension.
Two solutions for volumetric
(shrinkage) changes are being explored:
- The use of thin-walled IMS liners
(hereafter IMS socks) with holes
placed over the Buttons. These liners
would function as residual limb socks.
Nivea would not be applied over the
IMS Button Liner in the event of
shrinkage. The IMS sock would be
rolled onto it instead, and only then
would Nivea be applied. In this manner, the patient could adjust for shrinkage while still retaining suction suspension. The holes in the IMS sock allow
for a mechanical attachment to the
IMS Button Liner. Due to specific
Socket-Loc tolerances, it is surmised
that a maximum of two IMS socks
could be used. Redesign of the Button
would be required for the application
of more IMS socks.
- Using IMS Button Liners with internal' bladders, strategically located,
for appropriate distribution of increased contact pressures when inflated for 'accommodation of shrinkage. A
liner such as this would offer wearers
the aforementioned advantages of the
SOS system as well as uncompromising
suspension and adjustability. Developing custom-designed liners of this complexity is costly and time consuming.
For these reasons, the author has thus
far been unable to produce a working
prototype. It is hoped that such a device can be realized soon and presented
in this journal.
SOS with Socket-Loc for the
Upper-Limb Amputee
Considerable time was spent developing SOS systems for various upperlimb amputation levels while simultaneously developing the new SOS system for the lower limb. The difficulties
of one-handed liner application for
unilateral upper-limb amputees have
made application of the SOS system in
this population more difficult.
Infants, children, and young and mature adults (see Figure 32
, Figure 33
, Figure 34
, and Figure 35
) already
have been provided with this newer
technology. Myoelectric prosthetic
wearers also have been converted to
the SOS system with Socket-Loc and
the Ring. The results of this effort,
though mixed, have been favorable.
Due to the necessary limit of this article, this portion and further portions of
this investigation will be presented in a
future JPO.
Discussion
Forty-eight patients used this technique: 23 males, 18 females and seven
children (see Table 2
). Collectively, 27
patients used IMS liners (injection-molded), and the remaining 21 used
the IMS Button Liners (see Table 3
).
These figures are expected to change
because many of the IMS liner wearers
requested the Socket-Loc and Button
be added to their present designs. As
this chart does not distinguish device
types, only liner types, a disproportionate, larger IMS liner group appears. A more accurate assessment of
this event is captured in Table 4
.
Acceptance of the SOS system was
extraordinarily high with either the
[MS liner or IMS Button Liner. The
durability, improved suction and cushioning effect of the injection-molded
liners as compared with the previous
silicone-impregnated fabric liners were
viewed as highly favorable by the patients. There were three rejections (see
Table 5
).
A 58-year-old female transfemoral
amputee perceived pain in the distal
residuum when wearing the prosthesis.
The residual limb was redundant 10 cm
(4 inches) and was compressed distally
as a consequence of wearing the IMS
liner. Many solutions were explored to
alleviate this pain, including multiple
socket configurations, distal air chambers and variable thickness liners.
It is noteworthy that this individual's
existing prosthetic design distended the
redundancy. This elongated configuration, though normally inappropriate,
reduced the patient's discomfort. X-rays and physician consultations pointed to an unremarkable diagnosis. The
phenomenon of pain was clinically recognized to occur as a consequence of
mild distal compression.
The final solution for prosthetic acceptance required a traditional ischial
containment socket with a slightly
elongated distal end. On follow-up
some months later, a palpable mass
was detected at the most distal aspect
of the residuum. It was suggested to the
patient and physician to obtain a Magnetic Resonance Image (MRI) of the
limb. A ping-pong-ball-sized neuroma
was found and subsequently left untreated at the patient's discretion.
Two very active male transfemoral
amputees, both 40 years old, rejected
the SOS system due to inconvenience.
One individual did not like applying
Nivea or Vaseline over the IMS liner in
the morning when dressing because he
felt it was "messy." The other wearer
disliked reapplying a lubricant to the
liner during the day if the prosthesis
was removed for any reason.
Excepting the three rejections noted, the SOS system with either the IMS
liner or IMS Button Liner has proven
remarkably successful for lower-limb
applications. All patients previously fit
with laminated silicone liners greatly
preferred the IMS liners (either type)
with the exception of one patient. The
SOS system has demonstrated applicability to all age groups and various amputation levels. The Button and
Socket-Loc have been shown to rate
the highest level of acceptance and desirability based on the wearers' experiences with laminated and IMS liners.
Summary
A much improved Silicone-Only-Suspension (SOS) system has been described. The use of the Button, the
Ring, IMS and IMS Button Liners offers wearers significantly improved
comfort, durability and suspension.
The development and implementation
of the original Socket-Loc identified
design flaws that initiated appropriate
change. Prior rotational and suction-loss problems have been eliminated.
Socket-Loc (version 2) offers uncomplicated donning for patients and easier fitting and fabrication assignments
for prosthetists. The SOS system has
been applied successfully to patients of
all ages. Two new suction valves have
been described that facilitate convenience, reliability and cosmesis with
SOS and other suspension alternatives.
Continued development of this technique is expected to produce an adjustable SOS transtibial design.
Acknowledgments
An article of this size and diversity can occur only with the generous help of others.
My sincerest appreciation is offered to my
partner Robert A. Bedotto, CPO, LPT, the
most talented practitioner I have known.
My thanks also to the dedicated individuals in my employ who arrive early, leave
late and never know the time of day. They
are Arthur Sirdofsky, GPO, and professional photographer; Cathy Leone, artist
and moldmaker; Tom Fehl, CPO; John
Mitchell, RA(P); Peter Buffington, GO;
Lucille Mensch; Patrick Rohaley; Lois
Warner; Diane Chrisman; and Lisa Hallock.
I appreciate the continued support and
encouragement of The Rehabilitation Institute at Morristown Memorial Hospital
(RIMM); its physicians, therapists and administrators have all contributed to this effort.
My wife, Lynn B. Haberman, LPT, deserves recognition for her support and patience during the many long nights and
weekends. I am certain her critique of this
article and the insights she has offered have
enhanced its readability.
Finally, I wish to acknowledge the contributions of Wayne Koniuk, CP. The concept
of injection molding was explained to me
over dinner in San Diego in 1991. I hope
our profession will come to recognize
Wayne Koniuk for his many contributions
to the field.
LOUIS J. HABERMAN, CPO, is president of Garden State Orthoaedic Center, Oakland, N.J., adn Garden State Alliance Orthopedic Services, Inc., Morristown, N.J. He also is director of prosthetics and orthotics at The Rehabilitation Institute at Morristown Memorial Hospital, (201) 538-7039.
References:
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Some experience with prosthetic problems
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- Haberman U, Bedotto RA, Golodney EJ.. Silicone-only suspension (SOS) for
the above-knee amputee. J of Pros and
Orth Winter 1992; 4:2:76-85.
- Fillauer CE, Pritham CH, Fillauer
KD. Evolution and development of the silicone suction socket (3s) for below-knee
prostheses. J of Pros and Orth 1989; 1:2:92103.
- Koniuk W. A pure silicone BK socket
liner. Presentation at the annual meeting of
the American Academy of Orthotists and
Prosthetists, San Francisco, Calif. Winter
1986.
- Casper C. Informal discussion, National AOPA Meeting, Orlando, Fla. 1991.
- Howard B. Dow Corning Corp., Midland, Mich. Telephone conversation, January 1993.
- Bogue D. Design engineer, Boonton,
N.J.
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