Timely Neuropathy Testing
SPLINTING WITH THERMOPLASTIC
CLEAR VISION
REVEALS™
J Bell Krotoski, 2007
Both the coated and uncoated materials of CLEAR VISION
REVEALS™
when hot have a good memory, and if left immersed in hot water will return to
their original shape. This is desirable when one does not like a design or fit
and wants to start over quickly with no added material expense, or a splint
needs to be adjusted for changes in patient status and remolded.
It stands to reason that whatever splinting material is
used for external support and rebalancing of hand biomechanics needs to be that
most suited for fit, coverage, ease of fabrication, and strength. For
pre-formed splints that come in sizes, greater elasticity is sometimes helpful.
For a wide variety of custom-made splints moldability of the material during
fabrication becomes important, and the ability of the material to be slightly
stretched where needed and not return to its original shape. Uncoated
CLEAR VISION
REVEALS™
,
uncoated Aquaplast, or similar clone material (that turns clear when hot) has
distinct advantages over coated materials for splinting but has to be understood
and used for its unique properties. There is a necessary “learning curve” for
correct use of the uncoated material and it cannot be treated like other similar
coated material.
Details of Technique
1. Estimated size for a finger, hand based, or forearm
based splint can cut with a paper cutter. The pattern can be estimated, or
drawn on the material lightly with a ballpoint pen.
2. Heat the material can with a standard splint heat pan.
Use a liner in the pan to keep the material from sticking. The temperature of
the water should be just under boiling, if the water in the pan boils then
reduce the heat for the water. Water can be alternatively heated in a microwave
until it boils and used after it stops boiling for softening the immersed
material.
3. The opaqueness or translucency of the material signals
the degree of softening. Like sugar melting, as crystals tend to melt the
material heats and becomes clear, and in the reverse to reform as the material
becomes cooler like taffy candy.
4. Avoid heating the material
to clear for cutting out the splint pattern, or it will be too soft and
elastic. Cut the splint design out of the material when in the pan it
becomes opaque. Cutting while the material is opaque allows good control on
cutting edges preventing unnecessary reshaping for sharp edges later. Cutting
while the material is opaque prevents unwanted stretching and elongation of the
material.
5 . Immerse the material in the hot water until it becomes
clear once the pattern is cut.
Avoid having the pattern fold
over on itself in the pan as it will adhere to another piece of the
material and try to bond – don’t panic – so long as it is under water (unless
the pan is too hot) a gentle tug will separate the material again.
6. Remove an edge of the material first either with tongs
or by lifting the edge of the Teflon pan liner with tongs. When the material is
still clear but cool enough to be safely handled, carefully lift the material
from the water, and cradle the material to prevent unwanted stretching. The
material can be removed with the Teflon sheet, or placed on a Teflon sheet
outside of the pan if desired but this is often not necessary.
Once clear the material can be quickly immersed in room
temperature water to make it less sticky if the material seems too sticky.
7. If the material folds over on itself where not desired
when out of water, simply return it to the pan and separate under water.
Do not try to pull apart out of water!
8. If the material seems too hot or sticky, it can be
controlled by being immersed for an instant in another pan of room temperature
water to change its surface temperature without affecting the transparence and
its moldability overall.
9. The material should be allowed to cool slightly, but
not to become opaque (if it becomes cool too quickly and begins to become opaque
before being applied to the patient simply return it to the pan). Allowing the
material to cool slightly before being applied to the patient reduces the time
it take for the material to harden on the patient.
10. The time required for cooling and becoming hard allows
enough molding time for the splint in most cases,
11. When the material is applied to the patient it is
draped over the area desired for coverage by
the splint. Often the patient being splinted places his elbow on a table where
the hand assumes a functional position, and if needed a towel supports the
patient’s forearm.
12. The uncoated thermoplastic will adhere slightly to the
skin while heated, the heat transfer to the skin can be warmer to the skin than
non adherent (coated), so use caution when first
applying to a hand or body part, particularly one with fragile skin.
13. Once the splint maintains its shape, it can be loosened
slightly to allow a little air between the material and the skin and will speed
cooling.
14. Once heated, the splint will
take less time to be reheated until it is cooled completely. If
immersed too quickly in cool water for cooling, the
formed splint may shrink slightly, so it is best to let the material
cool while on the hand or other body part, and then be removed for final cooling
at room temperature.
15. To speed up cooling of the material for attaching
outriggers, etc, immerse a couple of minutes in cool water.
Advantages of “sticky” uncoated
-
Since the thermoplastic will adhere slightly to the skin while heated,
an exact and conforming shape can be made for the splint that fits the hand
or part splinted.
-
Since the thermoplastic will adhere slightly to the skin, usually
only one therapist is required to make a splint.
-
Since the thermoplastic will adhere slightly, the therapist has
two hands free to mold and shape.
-
Since the thermoplastic will adhere slightly, the therapist can
trim the material if necessary.
-
Since the material will adhere slightly, the mold follows the
normal curves of the hand, is improved biomechanically, and increases the
strength of the splint.
-
Since the thermoplastic will adhere slightly, every adjustment of
the splint for fit can often be made on the first mold, saving time.
-
Since the material is clear while warm, areas of ischemic pressure
can be seen and eliminated.
-
Since the material is clear while warm, areas of prominence such
as over the extensor tendons at MP joints can be relieved.
-
Since the material is clear while warm, skin creases where joints
move can be seen exactly while the splint is molded to restrict or remove
restriction to thumb, finger, or other joint movement.
-
Since the material is clear while warm, the splint is efficient
with material and covers only what has to be covered for support, allowing
removal of unnecessary material, or folding for comfort.
-
Since the material is clear while warm, exact folding of the
material at creases and edges movement increases comfort and strength of the
splint.
Final Touches
1. A final professional looking finish of the splint
surface and edges can be achieved. Once the splint is thoroughly cooled, it can
be immersed in hot water completely, or in sections to allow just the edges of
the splint to become translucent and shaped without affecting the body of the
splint.
2. A small dot of Vasoline rubbed over the thermoplastic
before it is immersed will allow excellent smoothing of the splint surface and
polishing of edges. Little time is required to make a perfect finish.
Remolding part of a
finished splint:
Since the crystals melt and
become opaque with increasing temperature of the material, control on the degree
of softening can be made by slowly immersing the part to be remodeled in hot
water, and gradually increasing the depth the splint is immersed and degree of
softening (The part immersed first will be the softest). Remolding a part of a
splint can be done in this way but requires this special consideration to assure
that the splint is not immersed where only a portion becomes clear with it’s
adjacent section remaining hard and completely opaque thus creating a hard
edge in the material.
A dry heat gun can also be
used to reheat only a part of the splint, if desired. For this the part to be
heated is only waved over the hear gun for short periods. The splint crystals
will continue to melt when taken away form the heat gun for a short period, so
the heating is controlled by exposing the splint part to the heat quickly,
observing the degree of opaqueness or translucency that results, and repeating
until the desired degree of heating is achieved.
Using the properties of the thermoplastic
material for modular parts:
A unique property of the
thermoplastic material is that it will adhere while hot – but not when cool.
This makes it possible to mold a splint section in a first stage and let it
cool, then mold a second stage of the splint and allow it to attach to the first
stage in a perfect bond and alignment until the second stage is cooled. When
cooled – which can be speeded in time by immersing in cold water – the parts can
gently be broken in their sections. This is particularly helpful, for instance,
when a wrist hinge splint is made, and it is important to have the hand base
perfectly align with the forearm base.
Even when both sections of
a splint are hot, the sections when cool will generally brake apart. This can
allow for a splint where an extended tongue of the material can be used as a
flap or strap, as when wrapping a thin piece of thermoplastic around a finger
when making a finger gutter type splint, or a volar and dorsal “sandwich”
splint.
At any time when desired,
the bond can be made permanent by heating until tacky both contact
surfaces to be adhered, and gently pressing these together (not completely clear
to avoid changing shape).
Attaching Outriggers
Metal outriggers,
prosthetic, parts can be attached easily to the thermoplastic material as the
uncoated material sticks well and conforms well to the metal. See Bonding
Thermoplastic.
Combining Coated and
Uncoated Material
Coated and uncoated
material can be combined in splint designs with a few considerations. While both
the uncoated and coated material are available in various degrees of elasticity,
the coated of the same degree of elasticity may seem more elastic as it tends to
pull away from the skin as it cools and tries to return to its original shape.
The uncoated material with the same degree of elasticity will seem to have less
elasticity and tendency to return to its original shape as it adheres to the
skin and holds its shape. Therapists should experiment with samples to see which
they can more easily use once they know and become familiar with properties of
the materials. A suggestion would be to start with a material in the mid range,
and more or less elastic or stretchy than desired move on to what seems to work
best in their hands.
For those therapists who want to primarily use the coated
material, once shaped, it can be treated for re-molding as the above. It can
also be made to adhere as above by scratching the surface to disturb the coating
where bonding is desired. It does not stick as well to metal parts, and may come
apart more easily. Keeping some of the uncoated material for bonding of parts
may be a reasonable solution. Or making one section of a splint with uncoated
material, and another section with coated may be another solution. There is also
an Ultra Coated version for those who do not want any degree of adhesion and
beginning splint fabricators.
Timely Neuropathy Testing.com J Bell Krotoski, 2007
