Re: Knee Disarticulation Socket

Re: Knee Disarticulation Socket

sarah day

4/14/2007

Dear Members,

I would like to thank everyone who responded to my question about
fabricating silicone end bearing pads for knee disarticulation amputees.

Here are the responses;

�You can make them from two part silicone foam and RTV or you can make
them from straight silicone. SPS foam A2370 plus straight RTV silicone.
Or Otto Bock silicone gel material

�SPS use to carry a two part foam for distal pads that you mixed and
poured into the socket and then dawned the socket and the foam would
conform to the residual. You have to drill a weep hole to allow the excess
to run out. Not sure if it is still available.

�The key to any end bearing pad is to make sure that there is no lip in the
final lamination. Thus, you must fabricate the final (laminated) socket
without the end pad, and add it afterwards. The easiest way I have found to
do this is to manufacture a check-socket with the pad, and then remove the
pad before filling in the check socket. Then, add plaster to smooth the
edges of the lip, so a nice smooth transition is there.
Hope this helps. I just dislike seeing edges between pads and the socket
that are in weight bearing areas...

�We use a elastic plaster cast, and layup a single layer of nylon with
the end sewn and make a funnel from a cup or x-ray film then pour fillaur
two part silicone into funnel and let it set up. Once it is set you can
trim the silicone with a scissors and grind it with care on a wire
wheel.

�I think you can use PVC monomet with DOp as plasticazer . You heat them and
pure to this area. It has very good form abilty and shock absorption.

�Otto Bock in Minn. has always been helpful. Normally you would do a distal
endcap and laminate over that. You would have to talk to them re: the seam
between the laminate and the silicone, and the silicone
durometer/soft/med/etc.


�Try UCO Quick-sil 1-800-541-4030


�Give a call to the good folks at Velocity Labs www.velocity-labs.com


�I have had success with the Ohio Willow Wood Alpha Caps. They are pre made
and tend to wear well.


�I have used a silicone putty very successfully for this type of
application.

�Leave your socket 1/4 inch (6mm) long and fill the void with this material.
  It forms perfectly under weight bearing. If you have far too much, your
patient will tell you they're end bearing. If you have just a minor amount
too much, somewhere on the periphery of the proximal edge the transition
will not feather out but rather, it will roll and be rounded. If you have
too little, it will not complete the contour.

�This product is available from Fillauer in Chattanooga, TN. It is sold in
one pound bricks.


�We have a lot of experience fabricating KD liners and sockets. Are you
familiar
with the KD socket used in the Netherlands? Basically, it consists of a
short
KD liner (superior to condyles) and an open frame socket consisting of a
closed
distal portion a strut upward to a circumferential band which is cut and
adjustable with a velcro closure.
Another method is to use a 3/4 length socket and a section of sealing
sleeve.


�Aliginate is a fine method to capture contours, but I find that it does not
capture the deformation of the shape in proper end loading.

�I try to manage the proximal volume with tubegauze sewed at the end,
suspended
in a ring with a Berkely transfemoral fixture. Elastic suspenders is
probably
fine. I wrap with rigid plaster distally (elastc doesn't deform properly).
Then
end bear to what is comfortable on somewhat compressible foam like FlexFoot
foam on a casting stand. I then wrap proximally to manage the proximal
volume. It is important to flatten the adductor area and femoral shaft since
the tendancy for the knee disartic socket is to rotate laterally about the
fulcrum at the distal end.

�otto bock do some eb pads, not sure if there is one big enough for a KD,
ohio williow wood do one too I have used it with a gel liner, there were
always problems keeping it in the same position. I'm sure TEC in the states
can make a custom one.


�I recently had TEC (Otto Bock) make a custom end pad for a very active KD
patient which worked quite well. You have to cast for the pad and send it
for fabrication. Then cast the patient wearing the pad for the socket.


Thank you all once again,

Sarah Day
BSc(Hons), MBAPO, SR ProsOrth

_________________________________________________________________
Message offline contacts without any fire risk!
<URL Redacted>