BKA / gel liner problem: RESPONSES

BKA / gel liner problem: RESPONSES

Paul Rieth

2/28/2006

Listservers,

Thank you for the replies. The original inquiry is listed below,
followed by the responses. No names will be listed, as my post was done
before Paul Prusakowski requested that names be kept in the summary of
responses. I had mentioned that I would not post names.

Inquiry:
36 y/o male, 260 lbs, level 2, left mid-length BKA

History: Patient initially did well with 6mm Alpha with pin.
Atrophy
ensued, leaving pronounced demarcation of the lateral and
lateral/distal
 borders of tibia. Scar tissue and adhesions present on
anterior/distal
and anterior/distal/lateral tibia. No invaginations. A cut in the
liner resulted at the level of the anterior/distal/lateral and lateral
tibial borders. I attributed it to a poorly fitting socket. He
was
re-casted for a 2nd socket, this time using a 6mm Cushion Dermoliner.
(Patient wanted to get away from the tackiness of the Alpha, stating
it irritated the scar tissue and his thigh.) Check socket revealed
total contact. A new socket was made. One week later, a cut in the
liner in the same locations.

Any ideas? I'd like to keep patient in some sort of gel interface due
to the scar tissue and adhesions, but I will try about anything.

Responses:

--I've run into that a few times, usually what I've found out is that
there is a traction occurring proximal to the area of liner tear,
resulting
in an elongation of the boney structure into the gel causing it to
tear. Try
to increase the pressure at the tear site and below that same area.
Reevaluate the proximal pressure to make sure there adequate but not
constricting socket reduction causing the initial hammock effect. I may
be
all wet, but, it could be the reason it is happening.

--a simple way to determine socket fit problems resulting in liner
tearing is this, if the liner tears longitudinally it is a result of
lack of contact, if the tears are horizontal it is the result of too
much contact. Also, I have not had good luck with Alpha liners due to
their inherant stretching that results in socket rotation, excessive
perspiration and excessive pistoning. I have the best luck with the
Iceross comfort plus, in the areas of scarring or adhesions instruct the
Patient to apply A&D ointment.

--IN a socket we made with similar problems, I incorporated pelite
right into
my socket over the area that was cutting the liner. I laminated it in
with
epoxy resin. I place my pad with feathered edges on top of the PVA and
them
do my normal layup. It worked out pretty well and saved a lot of
liners. It
gives slightly under the pressure.

--My suggestion would be take to your cast without a
liner...preferably 3 stage technique. Modify as for a conventional
PTB and build up the distal end.Lay up the type of liner you intend
to use over the modified cast and fabricate a clear test socket.You
 can expect to cut the liner so use an old one of correct size.
Dynamically align the socket with the patient wearing the correct
liner and using a sleeve suspension or (Fillauer type) skewer and
distal ring. Follow the procedures for alginating a total contact
socket.
It's an old method but may help.Further info can be reviewed by
 searching oandp website for total contact PTB sockets.

--Could your patient have had volume change after the check socket fit,
resulting in pistoning or excessive pull and stress on diatal end of
liner. You could refit previous check socket or I have been having
excellent results with cushion liners fit with suction suspension
(instead of locks). Just a thought.

--Are you fitting the patient with any socks are sheaths?
Does he do a lot of kneeling? Did you modify the socket like a TC or
PTB?
Does the patient use a suspension sleeve like a JUZO to reduce
stretching
and mild pistoning? These are all things to be checked before remaking
the
socket again. The area of tearing is usually seen in patients who kneel
or
work wear they will lean along that area like on a ladder or in a
warehouse
when moving pallets or when kneeling like a roofer, plumber , carpenter
etc.
In most cases by using a gel pad and relief in that area reduce the
chance
for tearing.
One other problem occurs when the patient is not donning his sleeves
properly and catches his pin on the gel after doing this a few times
the gel
will split.

--Some thoughts...I have found the Harmony to be good for these problem
limbs...however, fit must be PERFECT...and I have not yet found the
perfect system for modifying the VASS socket...so if you go that route,
be ready for extensive fittings and possibly multipe test sockets.
Another option would be a polyethylene locking system: Measure over the
liner of your choice, modify to provide pretibial compression/protect
the tibial borders, and have 3/32 polyethylene pulled over the mold.
Then, don the PE over the liner at a second appointment and the locking
liner of your choice (I like the Bock 6Y70, Iceross would do well
also)over the PE. Fiberglass wrap this over shrink wrap (wrap in a
shuttle lock placed in alignment) to protect the locking liner and have
a polypro frame made from the mold you get from the fiberglass. In this
way, you get shuttle lock simplicity with the polyethylene as an
insulating layer to protect the limb from external stresses. A bit
laborious, but certainly limb-friendly, eliminating the
pistoning/elongation forces from direct locking liner/skin interface.

--How about making a temporary walking socket from Otto Bock
thermolyn.
Its somewhat transparent. Or laminated if you prefer. Build a relief
into the socket by way of an Ossur or Medipro padding kit. They make
different shapes to use over odd shaped areas of a limb. You will use
a
dummy pad to create the impression into the socket. You replace it
with
a more durable adhesive pad included in the kits once the socket is
made. I would not think the limb is causing the tears or cuts. More
likely fingernails. But who knows.

--Otto Bock's (formerly TEC) urethane liner products with non-stick
interior surface; try pre-fabricated Profile or custom liner as
necessary. Don't be afraid to apply loads of non-dissipating lube
(A&D,
Vaseline jelly, etc.). If thigh isn't especially conical and may
accommodate suction-type sleeve, try dumping pin and using expulsion.
Can't think of single rationale for any liner to stick to skin.

--For problem patients such as this one I have always has success with
Otto
Bock custom TEC liners with non-stick coating in the inside. I have
stopped using Alpha Liners. I have a very long history of using them.
I have no regrets using other liners.

--I would suggest using a distal gel cup first then the gel liner over
that. That way if any cuts develop they will be in the easily
replaceable gel cup not in the liner itself.

--Does he leave the liner reflected inside-out when he cleans the liner
and
lets it dry? I haven't seen cuts develop that quickly, but I'm willing
to
bet Ossur will take the liner back. Verify his distal circumference
fits in
the liner size you've fitted him with, also.