Vacuum Casting Responses

Vacuum Casting Responses

John T. Brinkmann, CPO

10/16/1999

Here are the responses I received a while back in answer to my question
regarding the use of vacuum pressure casting systems:

Good question! I have been vaccum casting the last several BK's,
thinking it
was a good idea. I have had some good successes and like the idea in
principal. However, recently I used a custom TEC liner on a pt with a
conical
limb. I think the vaccum process elongated the TEC liner and ended up
giving
me too long of a distal end and distal edema eventually started to
appear. I
just spoke with another practioner who had a similar problem.

So.....I am not sure yet.
_________________________

I do like the concept of a very light vacuum to accurately define the
bony
prominences in the trans tibial amputation, but in my experience
(several
years ago), the socket ends up pretty snug. I have only done it without
any
socks. Next time I try it, I'll do it over a sock to capture the shape
and
attain the volume to accommodate a sock in the finished socket.

________________________

I have little experience with vacuum casting but I can offer you this
fact.

If you vacuum 'cast' any shape you will only 'conform' to that shape,
but
never 'influence' it. The question has to be 'is the 'shape' you are
going
to cast the shape you want, because that is what you will get?'

This is the big difference between vacuum casting and pressure casting.

With pressure casting you will 'influence' the shape. Personally, I
prefer
pressure casting as a concept because I believe the 'passive' shape of
the
residual limb is not the shape I want. So I influence that shape by
applying pressure.

I think this point is often over-looked, but is very important when folk

start to compare the two.

Hope you find this informative.
_______________________

I found vacuum casting beneficial for BK patients that had redundant
tissue. The vacuum tended to firm up the tissue.

 Presently I stick to hand casting or a CAD system.
_______________________

I have had remarkable success with vacuum casting TSB sockets, and use
it at
all times when using a viscous material either for comfort or
suspension.
How much compression varies greatly depending on application.
_______________________

John, I recently took the TEC class here in Minnesota and purchased one
of
their vacuum pumps for casting. I have been pleased with my casts so
far, I
have used it for TEC products as well as Iceross liners and sockets.
Cast
mods are minimal, they come out very smooth. Just vacuum the plaster on
the
limb and let it set up. Contact them for a list of classes they offer.
My
patients were impressed by how good the sockets felt when they were fit.

Socket adjustments were minimal also. It works for me.
________________________

Thanx to all who took the time to respond with their insights.

John T. Brinkmann, CPO