Air Pocket Sockets

Air Pocket Sockets

John T. Brinkmann, CPO

9/17/1999

List Members:
I received several responses to my questions about chronic distal end
breakdown, etc. Most were brief, and had to do with affirming need for
appropriate distal contact, use of specific types of liners, and the
need for revision. Two prosthetists suggested joint/corset to relieve
distal weight bearing, and reported good success with that treatment
method. I also received input via a phone call that stressed the need
to address the chronic infection prior to solving the problems with a
different liner or modification method. Thanks to all who took the time
to respond.

I am including the latest message I received, since it deals with the
specific question of air pockets (bladders) in sockets, as well as
covering most of the issues mentioned in the other responses. Thanks,
F.C.

Sincerely:

John T. Brinkmann, CPO

Subject: Air Pocket Sockets
> Date: Tue, 14 Sep 1999 14:39:35 -0500
> From: John T. Brinkmann, CPO < <Email Address Redacted> >
> Organization: Rockford Orthopedic Appliance
> To: <Email Address Redacted>
>
> I am currently seeing a pleasant, responsible, and compliant gentleman

> who has bilat TT (BK) amputations. (Rt: '85; Lt: '91) He is diabetic
> and has very little soft tissue on either residual limb. The distal
> ends of the RLs are very sharp - worse on left side. He has had
> problems with distal end ulceration on both RLs, but the right is
> currently resolved. He had a revision on the rt. side due to bone
> infection - after prolonged ulceration of the distal tibia. I am the
> third prosthetist in several years to work with him.
>
> Many different liners have been tried - pelite and gel, non-locking
and
> locking. I have him in an Alpha Locking liner (6mm, medium,
contoured).
> There are several other options I want to try with him, but would like

> to get your perspective before proceeding any further.
>
> 1. Is it possible that the distal tibia is so sharp that the
ulceration
> will occur regardless of what material the distal RL contacts in the
> socket? Is this suggestion simply a cop-out?
> 2. What are the merits of inflatable pockets in the socket in
> addressing this situation? I have always considered them more
> applicable for larger RLs with greater variations in volume. Any
> experience with the Otto Bock inflatable liner?
> 3. I have had good success with the TEC liner for an extremely
brittle
> diabetic. Is the sharp distal end a contra-indication for use of the
> TEC liner?
>
> Thank you for your consideration of these questions.
>
> Sincerely:
>
> John T. Brinkmann, CPO
>


Dear John:

It is our experience, that total contact sockets with a hydrostatic
pressure builtup almost always work much better than, e.g., PTB-type
sockets with no load bearing at all at the distal end. We have recently
provided a young TT amputee having a very sharp distal end of the tibia
protruding about 1 inch over the rest of the RL with such a total
contact socket. In order to pad the tibia as well as to close the deep
scars that patient also has, we made a distal cup from silicone
according to an alginate impression we took from the distal RL. Over
that, the patient is wearing a standard silicone liner (ICEROSS) with a
locking pin. For about 6 months now, the patient has had no problems
whatsoever. However, this is a young traumatic amputee and this case
might no be comparable to your diabetic patient.

Here, my opinion to your questions:

1. If the ulcers are all closed and the infection you are mentioning
is successfully controlled, I do not believe, that the distal end of the

RL cannot bear any load at all, even if the tibia is sharp. It's
probably a matter of appropriate padding. A custom made distal cup with
1/2 padding made from Shore A 5 or so silicone might be a good
approach. Also, a custom TEC liner might be worth a try.
It is my opinion, that distal ulceration in a BK socket is just as
likely to occur with no load at all at the distal end of the RL as with
too much load because if there is no pressure on the distal RL, blood
circulation is likely to be diminished and localized edemas might break
the skin from inside.
2. Although, my company is the manufacturer of the Pneumatic Volume
Control (PVC) system, which ipos, Niagara Falls, N.Y., is distributing,
I do not suggest the use of any inflatable pockets in the very case you
are discribing where volume variations of the RL do not seem to be the
problem.
We do not have direct experience with the Otto Bock inflatable liner.
However, as far as I understood the Otto Bock concept, that liner has
neither been designed for distal padding nor for volume control. I
think, Otto Bock simply wants to reduce the so called milking effect on
the distal RL. We have heard, that short BK RLs are likely to be pushed
out of the socket when the Otto Bock liner is inflated. For appropriate
distal end load bearing, a non compressible distal padding material
seems to me to make more sense. However, the volume of the socket must
be just right!
3. Yes, the TEC liner might be a good choice (see obove).

Needless to say, the suggestions given are according to our experience
and are our opinion only. There might be other approaches or better
solutions for the particular case mentioned.

I hope, our considerations will help to find the best possible solution
for your patient.

Sincerely:

Felix Carstens
Carstens Orthopaedie- und Medizintechnik GmbH, Germany

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