TECHNICAL FORUM--The Use of Silicone
Suspension Sleeves
with Myoelectric
Fittings
Youssef Salam, MSME, CP
ABSTRACT
The use of silicone sleeves is very common in lower-extremity prosthetics (1,2,3). These sleeves, whether custom fabricated or off-the-shelf provide suction suspension when
used with a shuttle lock b system (see Figure 1
). The use of
these suspension methods for upper-extremity myoelectric
prosthetics is described here.
Introduction
Until recently, conventional suspension methods were
used in favor of silicone sleeves in upper-extremity fittings.
Harnesses were used with body-powered prostheses and
will continue to be used because transmitting power requires harnesses. Myoelectric prostheses, however, eliminate the need for harnesses and employ other suspension
options, such as direct-suction suspension for transhumeral amputations and supracondylar suspension for
transradial amputations. Silicone suspension sleeves add a
new method of suspension.
This technical forum describes a technique for using
silicone suspension sleeves with myoelectric fittings. In
addition to providing suspension, these sleeves:
- allow lower trimlines for increased range-of-motion
- allow fitting of heavily scarred residual limbs
- allow more proximal placement of electrodes, if needed, without fear of breaking suction (as occurs with use of
transhumeral sockets)
Casting
A proper size ICEROSS sleeve, or comparable, is rolled
over the transradial or transhumeral residual limb. Bony
prominences are marked on the sleeve with
washable markers. (Or
one can use a casting
balloon on top of the
sleeve.) The impression is then taken in
the regular fashion.
Higher trimlines can
still be achieved for
shorter residual limbs
or for additional support or control.
Diagnostic Socket
The positive mold is
modified as usual, and
a clear diagnostic socket is fabricated with
the shuttle lock attachment connected distally. This can be done by
placing the shuttle lock
on the model before
vacuum-forming the plastic. Next, testing for myoelectric
sites is completed, and the residual limb is marked at these
sites.
Two electrode dummies, such as the Otto Bock 13E83
blue electrode pattern, are secured to the residual limb over
the myosites by tape or snug elastic band. The ICEROSS
sleeve is then rolled over the residual limb on top of the
electrode dummies. Care should be taken not to
move the dummies while
donning the sleeve. The
sleeve is marked over the
site of the dummies. The
procedure of donning
the sleeve should be repeated to assure consistency.
Afterwards, two holes
are cut in the sleeve at
the marked electrode
sites. It is a good practice
to cut small holes at first
to ensure the holes are
accurately placed over
the electrode sites. The
sleeve is then re-applied
on the residual limb.
Holes made in the
sleeve should coincide
with the electrode sites
marked on the skin (see
Figure 2
). Application of the sleeve over the residual limb
should be repeated to double-check the accuracy of the
hole placement. If the holes in the sleeve do not coincide
with the marked myoelectric sites, the holes can be enlarged (see Figure 3
). Next, a clear diagnostic socket is
donned and checked for fit.
Rubbing alcohol is sprayed on the sleeve for easier donning. Adjustments are made to the socket, and the myoelectric sites are transferred to the diagnostic socket. The
normal prosthetic fabrication procedure can now be followed. Diagnostic myoelectric control can be achieved by
cutting two holes in the clear diagnostic socket corresponding to the marked myoelectric site, then the two electrodes
of the myotester can be taped to the outside of the diagnostic socket over the cut holes. Skin usually bulges through
the silicone sleeve holes to make direct contact with the
electrodes. The myoelectric control test follows.
Trimming the Sleeve
The silicone sleeve is marked at least one inch proximal to
the socket's brim all the way around. The sleeve is marked
at the biceps tendon to create a reference point. The sleeve
is then trimmed at an angle leaving more material posteriorly than anteriorly, allowing more flexion of the residual
limb.
The patient needs to practice donning the sleeve by
aligning the mark on the sleeve with the bottom of the
biceps tendon. Myoelectric control is tested again before
diagnostic fitting is completed.
With a transhumeral amputation, a mark corresponding
to the acromion process is made. The sleeve is cut lower
medially at the axilla, and the patient practices donning the
sleeve to match the mark on it with the acromion process.
One site control can be achieved by following the same
procedure on one side only. Electrode sites should be
optimized before holes are cut in the sleeve to assure continuity of myocontrol in case of minor slippage or inaccurate
donning of the sleeve.
Once the diagnostic fitting is finished, the definitive
prosthesis is fabricated following normal procedures. The
shuttle attachment placement should be duplicated in the
definitive prosthesis. Using such a suspension system requires additional room distal to the socket. A compact
shuttle lock system that requires about 18-mm (3/4-inch) of
space distal to the socket is available through Fillauer.
Using floating electrodes, such as the Otto Bock 13E84 1
flexible mounting set or comparable, assures continued
contact with the skin throughout the full range of motion.
YOUSSEF SALAM, MSME, CP, is the supervisor and lead instructor of the P&O training program at the American University of Beirut Medical Center, P.O. Box 11-0236, Beirut, Lebanon.
References:
- Kristinsson 0. The ICEROSS concept: a discussion of a
philosophy. Prosthetics and Orthotics International 1993;
17: 1:49-55.
- Fillauer CE, Pritham CH, Fillauer KD. Evolution and development of the silicone suction socket (3S) for below-knee
prostheses. JPO 1989; 1:2:92-103.
- Wall M. Silicone BK sockets. Indications and acceptance.
Proceedings of 7th World Congress of the ISPO, Chicago, USA,
1992: 42.
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