Elevated Vacuum Responses
Luci Busch
Description
Collection
Title:
Elevated Vacuum Responses
Creator:
Luci Busch
Date:
9/18/2008
Text:
Dear colleagues,
Listed below is my original post concerning fabrication, connection and
reliability issues with the various elevated vacuum systems and the
responses I received. Thank you to all that responded.
We have been working on integrating the various elevated vacuum systems
into our clinical practice due the documented benefits seen by a broad
spectrum of patients and residual limb types. In doing so we have
noticed a few problems that seem to be inherent across the board no
matter what system we use. One of the more prevalent issues that we are
running into is the somewhat labor intensive socket fabrication and the
consistency in which we are able to receive a socket that does not have
a leak. We have also had problems with sockets developing leaks because
the bond between the socket and fabrication plate has broken. We use a
central fabrication and the technicians have been thoroughly trained in
the fabrication of the Otto Bock VASS socket and OWW Limb Logic
fabrication as well. The lack in reliability and cost of the socket
fabrication, which requires a PETG lining have become an issue. The
systems also do not seem to be very CAD friendly in terms of fabrication
and connecting options. The other issue that we are experiencing is
the frequency in which our patients are putting holes in their sealing
sleeves. We have followed the manufacturer's recommendations to prolong
the life of the sleeves, however it seems like the problem is still
significant. Both the issues I presented obviously cause the systems to
lose vacuum and therefore the fit of the prosthesis is compromised. We
have had patients show up to clinics and appointments with referral
sources without a fully functioning prosthesis and with compromised
suspension.
RESPONSES:
1. Unfortunately, it is these issues which have caused me to be very
conservative as far as when I recommend these types of systems. I have
had the same issues. It is wonderful technology.....when it works
2. There are a few new attachment components that are available from
Prosthetic Design (PDI) that can help you with the socket leak issues
that you have been experiencing. PDI has a version of their shuttle
lock that is designed for use with all the major elevated vacuum systems
as well as a four-hole attachment plate that creates an air tight socket
for use with non-locking liners. The locking mechanism provides for a
secure secondary suspension if the vacuum should fail for any reason.
The components are modular and make for easier diagnosis of socket leaks
and can be transferred if a socket replacement is necessary. Both of
these components will allow for the fabrication of a CAD friendly
thermoplastic socket with European 4-hole attachment pattern. The fact
that you can use a thermoplastic instead of a laminated socket will help
simplify your fabrication, reduce time and cut the cost as well. Use of
a thermoplastic socket may also help prolong the life of the problematic
sealing sleeves by reducing the wear and tear with softer, more rounded
trim lines.
3. I would recommend you take a good look at the new BK and AK 5 ring
Seal In liner. No knee sleeve problems - great knee flexibility and
socket fabrication is not an issue. Easy donning, rotation control and
incredible suspension!
4. We are a central fabrication facility located in Florida that
specializes in high vacuum socket systems. I worked for TEC as the R&D
director during the development of the harmony system and ran into a lot
of the issues you mentioned. We have developed a new plate and valve
system that seals directly to the lamination through the center of the
plate. The valve face is large enough for the limb logic system to seal
to, replacing the OWW plate. This also provides an additional valve
between the socket and any high vacuum system, so, if there is a leak in
the hose or the vacuum system the socket still acts as an expulsion
socket. This plate and valve system is also available for purchase if
you wish to produce the sockets at your facility. This system can also
work as just an expulsion valve. The plates and valves are reusable and
can be easily mounted to a check socket. The sleeves are a different
story anytime something is made soft and flexible you sacrifice
durability we've found making a laminated over- cover is the best way to
protect any sleeve.
More information is available at www.velocity-labs.com
<blocked::outbind://40-00000000F1736D821F9DB148BEE201140539B8A10700CAC6A
572A5D32144BA2BA2BC7DAD15530000000030E30000CAC6A572A5D32144BA2BA2BC7DAD1
553000000283D0E0000/www.velocity-labs.com> in the products section.
5. That inner PETG plastic to be honest is absolutely useless. As long
as you use full suction (20+ psi) when laminating your inner socket you
will not have any leaks from the socket.
As for the suspension sleeve, we are using Sticky Sleeves from Alps
(part# SFS28-6). We tell our patients to start out wearing the
suspension sleeve rather high on their thigh. Then as holes occur,
gently lower the suspension sleeve so that the hole is now on the socket
as opposed to being at the trim lines. Once the hole is moved down on
the socket it will seal again and prolong the life of the sleeve. If the
patient is extremely active, we use the Alpha Flex Sleeve from OWW which
has a Kevlar reinforced knee area. This works well for extreme amputees.
However, we tried this sleeve on lower activity patients in an attempt
to stop holes from developing and that was a bad idea. Because the knee
area is reinforced, there is not much flex to it. So as the patient sat
for most of their day the kevlar pushed on the patella causing severe
pain. Good Luck!!!
6. Use standard CADCAM set-up techniques for the distal adaptor and
fabrication, and then mix a lightweight microballon resin slurry to form
in place the distal contouring for the socket, with your patient wearing
a lubed latex casting balloon. Use a thin tube or other type of air
wick up the posterior aspect to evacuate air as the limb is inserted
into the socket. Drill out a vacuum channel through the formed resin
and you should have a good VASS socket shape.
Regarding beaches in the suspension sleeve, I have found that using at
least a 6mm suspension sleeve is necessary to resist punctures, and if
punctured the 6mm or thicker sleeves tend to self-seal better than the
thinner ones. The use of a gaiter under the sleeve, such as the Otto
Bock gaiter, or better, a cut-off ALPS Clearline suspension sleeve,
helps to prolong the life of the suspension sleeve. Rotate either the
gaiter or the suspension sleeve to a new position if punctured, so that
the hole is not continuous through both the sleeve and the gaiter, and
suction should be restored.
7. I have used traditional harmony pump and now the limblogic.
Limblogic first...The loss of vacuum between socket and plate is solely
a technician fabrication issue. I struggled with it as well. the techs
absolutely need to fab by the book, when they do, it is terrific. if
they scratch up the plate or use masking tape over the hole, cover the
plate with fiberglass wrap during test fitting, or don't seal the hole
with the epoxy, then it will definitely leak....It is so simple casting
and fabricating the limblogic compared to the harmony...standard alpha
reductions. 0 ply fit.... if you use more than a couple ply of sock,
then you lose the value of the system.......We have had great sucess
with AK and BK about 20 each....harmony, pump is good... for the right
person..... i have stopped using them,except for old wearers..too much
labor...too heavy, ... we are switching many over to limblogic....
Sleeves... My most recent limblogic pt. is a vet student... always
crawling on the floor playing with and working with animals.... She has
destroyed every gel sleeve on the market.......literaly she loves the
Daw sleeve for comfort,,,, bock Gaitor sleeve to seal and protect. The
Alpha Flex sleeve is great, but she needs a size 3.5..... they don't
make a 3.5...the 3 is supertight and 4 huge. The alpha flex sleeve
works great for most vacuum systems.. it is a Brand new sleeve. with
reinforced brim protector...but patient cannot kneel on it or any other
gel sleeve with out breakdown/cut... we find that the anterior brim of
the socket is cutting thru the gel at first kneel.......she got so
frustrated that she found a rubber starfish toy and stuck it over the
ant. brim between the brim and the gel liner,.. sandwiched in between.
No breakdown in 3 weeks. so far...I had tried scrap gel from other cut
liners... the scrap gel cut thru quickly as well......So the heavy duty,
yet flexible rubber of the toy starfish is tough enough to prevent
cutting of the sleeve.....possibly use strips of leather or hd rubber to
cover the brim ...pt can just set it against brim to protect..
8. Saw your post and thought I'd respond. This is related to your
question and in the near future maybe helpful to your practice. During
the month of October, I will be presenting at both the New England
Chapter and the NC/SC Chapter AAOP meetings on a product that we've been
developing. Below is the conference schedule for the NC/SC meeting. The
title and details will give you an idea of how this system will work.
We have several patients using this system with excellent results. One
BK amputee, even rode cross country on a bicycle with no failure with
the system.
9. Same problems and issues for years. I know no one that can say that
they have resolved these issues honestly. The fiddle factor with these
systems are very high regardless of the flavor used. Most patients do
not want a high maintenance fake leg. Rarely does a cost benefit
analysis tilt the scales toward elevated vacuum over a suction/
suspension sleeve system.
10. We have been doing BK Harmony prostheses for 3 years and vacuum
AK's this year. We use a single lamination technique to fabricate our
own sockets over a PETG layer and never have a leak through the socket
wall. Sealing sleeves are another matter: we have found none that really
last. Our current favorite is the OWW Alpha Flex Sleeve: with
hand-sanded trim-lines you shouldn't need a gaiter. We're still waiting
for a really good sealing sleeve.
11. I too have had problems with sleeves and leaks but some of the
problems were due to making sure certain things were consistent and that
the use of attachment systems were still problematic if your using
systems other than those with four hole pattern connectors. The most
common problem with the sleeves has been that the top edges of the
sockets had carbon, Kevlar , spectra or fiberglass which can all cause
wear and tear on the sleeve. using the under sleeve like the bock helps
but I've found that the ALPS and the Euro international sleeves seem to
hold up better. The way in which you size the sleeve is also important,
too snug and they wear too fast, too loose and the stretch too fast.
As far as the socket leaks, in most cases the pteg is too thin or when
bonding the lamination to the PTEG inner layer the material had an air
bubble this then causes the separation of the sockets. As far as
fabrication plates breaking that is usually due to thinning of the
lamination and PTEG where they are being prepared for attachment. I have
found that using carbon reinforcing tape over the distal end eliminates
the problem but only if the crisscross is intact. If the tech grinds it
down for attachment they could be cutting right through the
reinforcement. I have found some of the Coyote products helpful in the
bonding of parts. Finally if the leakage and breakage problem is still
happening maybe you should try a different central fabrication company.
Luci Busch, CP
Licensed Prosthetist
Sr. Director of Clinical Services
<Email Address Redacted>
<mailto:<Email Address Redacted>>
High quality lower extremity prosthetics with personalized, unparalleled
patient care.
Dayton Artificial Limb, Inc.
7637 N. Main Street
Dayton, Ohio 45415
Voice 937.898.2200
888.827.0984
Fax 937.898.2234
This email message and its attachments (if any) are intended solely for
the use of the addressee(s) hereof. Access to this email by anyone else
is unauthorized. In addition, this message and the attachments (if any)
may contain information which is confidential, privileged and exempt
from disclosure under applicable law. If you are not the intended
recipient of this message, you are prohibited from reading, disclosing,
reproducing, distributing, disseminating, or otherwise using this
transmission. Delivery of this message to any person other than the
intended recipient is not intended to waive any right or privilege. If
you have received this message in error, please promptly notify the
sender by reply email and immediately delete this message from your
system.
Listed below is my original post concerning fabrication, connection and
reliability issues with the various elevated vacuum systems and the
responses I received. Thank you to all that responded.
We have been working on integrating the various elevated vacuum systems
into our clinical practice due the documented benefits seen by a broad
spectrum of patients and residual limb types. In doing so we have
noticed a few problems that seem to be inherent across the board no
matter what system we use. One of the more prevalent issues that we are
running into is the somewhat labor intensive socket fabrication and the
consistency in which we are able to receive a socket that does not have
a leak. We have also had problems with sockets developing leaks because
the bond between the socket and fabrication plate has broken. We use a
central fabrication and the technicians have been thoroughly trained in
the fabrication of the Otto Bock VASS socket and OWW Limb Logic
fabrication as well. The lack in reliability and cost of the socket
fabrication, which requires a PETG lining have become an issue. The
systems also do not seem to be very CAD friendly in terms of fabrication
and connecting options. The other issue that we are experiencing is
the frequency in which our patients are putting holes in their sealing
sleeves. We have followed the manufacturer's recommendations to prolong
the life of the sleeves, however it seems like the problem is still
significant. Both the issues I presented obviously cause the systems to
lose vacuum and therefore the fit of the prosthesis is compromised. We
have had patients show up to clinics and appointments with referral
sources without a fully functioning prosthesis and with compromised
suspension.
RESPONSES:
1. Unfortunately, it is these issues which have caused me to be very
conservative as far as when I recommend these types of systems. I have
had the same issues. It is wonderful technology.....when it works
2. There are a few new attachment components that are available from
Prosthetic Design (PDI) that can help you with the socket leak issues
that you have been experiencing. PDI has a version of their shuttle
lock that is designed for use with all the major elevated vacuum systems
as well as a four-hole attachment plate that creates an air tight socket
for use with non-locking liners. The locking mechanism provides for a
secure secondary suspension if the vacuum should fail for any reason.
The components are modular and make for easier diagnosis of socket leaks
and can be transferred if a socket replacement is necessary. Both of
these components will allow for the fabrication of a CAD friendly
thermoplastic socket with European 4-hole attachment pattern. The fact
that you can use a thermoplastic instead of a laminated socket will help
simplify your fabrication, reduce time and cut the cost as well. Use of
a thermoplastic socket may also help prolong the life of the problematic
sealing sleeves by reducing the wear and tear with softer, more rounded
trim lines.
3. I would recommend you take a good look at the new BK and AK 5 ring
Seal In liner. No knee sleeve problems - great knee flexibility and
socket fabrication is not an issue. Easy donning, rotation control and
incredible suspension!
4. We are a central fabrication facility located in Florida that
specializes in high vacuum socket systems. I worked for TEC as the R&D
director during the development of the harmony system and ran into a lot
of the issues you mentioned. We have developed a new plate and valve
system that seals directly to the lamination through the center of the
plate. The valve face is large enough for the limb logic system to seal
to, replacing the OWW plate. This also provides an additional valve
between the socket and any high vacuum system, so, if there is a leak in
the hose or the vacuum system the socket still acts as an expulsion
socket. This plate and valve system is also available for purchase if
you wish to produce the sockets at your facility. This system can also
work as just an expulsion valve. The plates and valves are reusable and
can be easily mounted to a check socket. The sleeves are a different
story anytime something is made soft and flexible you sacrifice
durability we've found making a laminated over- cover is the best way to
protect any sleeve.
More information is available at www.velocity-labs.com
<blocked::outbind://40-00000000F1736D821F9DB148BEE201140539B8A10700CAC6A
572A5D32144BA2BA2BC7DAD15530000000030E30000CAC6A572A5D32144BA2BA2BC7DAD1
553000000283D0E0000/www.velocity-labs.com> in the products section.
5. That inner PETG plastic to be honest is absolutely useless. As long
as you use full suction (20+ psi) when laminating your inner socket you
will not have any leaks from the socket.
As for the suspension sleeve, we are using Sticky Sleeves from Alps
(part# SFS28-6). We tell our patients to start out wearing the
suspension sleeve rather high on their thigh. Then as holes occur,
gently lower the suspension sleeve so that the hole is now on the socket
as opposed to being at the trim lines. Once the hole is moved down on
the socket it will seal again and prolong the life of the sleeve. If the
patient is extremely active, we use the Alpha Flex Sleeve from OWW which
has a Kevlar reinforced knee area. This works well for extreme amputees.
However, we tried this sleeve on lower activity patients in an attempt
to stop holes from developing and that was a bad idea. Because the knee
area is reinforced, there is not much flex to it. So as the patient sat
for most of their day the kevlar pushed on the patella causing severe
pain. Good Luck!!!
6. Use standard CADCAM set-up techniques for the distal adaptor and
fabrication, and then mix a lightweight microballon resin slurry to form
in place the distal contouring for the socket, with your patient wearing
a lubed latex casting balloon. Use a thin tube or other type of air
wick up the posterior aspect to evacuate air as the limb is inserted
into the socket. Drill out a vacuum channel through the formed resin
and you should have a good VASS socket shape.
Regarding beaches in the suspension sleeve, I have found that using at
least a 6mm suspension sleeve is necessary to resist punctures, and if
punctured the 6mm or thicker sleeves tend to self-seal better than the
thinner ones. The use of a gaiter under the sleeve, such as the Otto
Bock gaiter, or better, a cut-off ALPS Clearline suspension sleeve,
helps to prolong the life of the suspension sleeve. Rotate either the
gaiter or the suspension sleeve to a new position if punctured, so that
the hole is not continuous through both the sleeve and the gaiter, and
suction should be restored.
7. I have used traditional harmony pump and now the limblogic.
Limblogic first...The loss of vacuum between socket and plate is solely
a technician fabrication issue. I struggled with it as well. the techs
absolutely need to fab by the book, when they do, it is terrific. if
they scratch up the plate or use masking tape over the hole, cover the
plate with fiberglass wrap during test fitting, or don't seal the hole
with the epoxy, then it will definitely leak....It is so simple casting
and fabricating the limblogic compared to the harmony...standard alpha
reductions. 0 ply fit.... if you use more than a couple ply of sock,
then you lose the value of the system.......We have had great sucess
with AK and BK about 20 each....harmony, pump is good... for the right
person..... i have stopped using them,except for old wearers..too much
labor...too heavy, ... we are switching many over to limblogic....
Sleeves... My most recent limblogic pt. is a vet student... always
crawling on the floor playing with and working with animals.... She has
destroyed every gel sleeve on the market.......literaly she loves the
Daw sleeve for comfort,,,, bock Gaitor sleeve to seal and protect. The
Alpha Flex sleeve is great, but she needs a size 3.5..... they don't
make a 3.5...the 3 is supertight and 4 huge. The alpha flex sleeve
works great for most vacuum systems.. it is a Brand new sleeve. with
reinforced brim protector...but patient cannot kneel on it or any other
gel sleeve with out breakdown/cut... we find that the anterior brim of
the socket is cutting thru the gel at first kneel.......she got so
frustrated that she found a rubber starfish toy and stuck it over the
ant. brim between the brim and the gel liner,.. sandwiched in between.
No breakdown in 3 weeks. so far...I had tried scrap gel from other cut
liners... the scrap gel cut thru quickly as well......So the heavy duty,
yet flexible rubber of the toy starfish is tough enough to prevent
cutting of the sleeve.....possibly use strips of leather or hd rubber to
cover the brim ...pt can just set it against brim to protect..
8. Saw your post and thought I'd respond. This is related to your
question and in the near future maybe helpful to your practice. During
the month of October, I will be presenting at both the New England
Chapter and the NC/SC Chapter AAOP meetings on a product that we've been
developing. Below is the conference schedule for the NC/SC meeting. The
title and details will give you an idea of how this system will work.
We have several patients using this system with excellent results. One
BK amputee, even rode cross country on a bicycle with no failure with
the system.
9. Same problems and issues for years. I know no one that can say that
they have resolved these issues honestly. The fiddle factor with these
systems are very high regardless of the flavor used. Most patients do
not want a high maintenance fake leg. Rarely does a cost benefit
analysis tilt the scales toward elevated vacuum over a suction/
suspension sleeve system.
10. We have been doing BK Harmony prostheses for 3 years and vacuum
AK's this year. We use a single lamination technique to fabricate our
own sockets over a PETG layer and never have a leak through the socket
wall. Sealing sleeves are another matter: we have found none that really
last. Our current favorite is the OWW Alpha Flex Sleeve: with
hand-sanded trim-lines you shouldn't need a gaiter. We're still waiting
for a really good sealing sleeve.
11. I too have had problems with sleeves and leaks but some of the
problems were due to making sure certain things were consistent and that
the use of attachment systems were still problematic if your using
systems other than those with four hole pattern connectors. The most
common problem with the sleeves has been that the top edges of the
sockets had carbon, Kevlar , spectra or fiberglass which can all cause
wear and tear on the sleeve. using the under sleeve like the bock helps
but I've found that the ALPS and the Euro international sleeves seem to
hold up better. The way in which you size the sleeve is also important,
too snug and they wear too fast, too loose and the stretch too fast.
As far as the socket leaks, in most cases the pteg is too thin or when
bonding the lamination to the PTEG inner layer the material had an air
bubble this then causes the separation of the sockets. As far as
fabrication plates breaking that is usually due to thinning of the
lamination and PTEG where they are being prepared for attachment. I have
found that using carbon reinforcing tape over the distal end eliminates
the problem but only if the crisscross is intact. If the tech grinds it
down for attachment they could be cutting right through the
reinforcement. I have found some of the Coyote products helpful in the
bonding of parts. Finally if the leakage and breakage problem is still
happening maybe you should try a different central fabrication company.
Luci Busch, CP
Licensed Prosthetist
Sr. Director of Clinical Services
<Email Address Redacted>
<mailto:<Email Address Redacted>>
High quality lower extremity prosthetics with personalized, unparalleled
patient care.
Dayton Artificial Limb, Inc.
7637 N. Main Street
Dayton, Ohio 45415
Voice 937.898.2200
888.827.0984
Fax 937.898.2234
This email message and its attachments (if any) are intended solely for
the use of the addressee(s) hereof. Access to this email by anyone else
is unauthorized. In addition, this message and the attachments (if any)
may contain information which is confidential, privileged and exempt
from disclosure under applicable law. If you are not the intended
recipient of this message, you are prohibited from reading, disclosing,
reproducing, distributing, disseminating, or otherwise using this
transmission. Delivery of this message to any person other than the
intended recipient is not intended to waive any right or privilege. If
you have received this message in error, please promptly notify the
sender by reply email and immediately delete this message from your
system.
Citation
Luci Busch, “Elevated Vacuum Responses,” Digital Resource Foundation for Orthotics and Prosthetics, accessed November 1, 2024, https://library.drfop.org/items/show/229484.
