Note: Descriptions are shown in the official language in which they were submitted.
AMPUTAT I ON APPARATUS
BACKGROUND OF THE INVENTION
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This invention relhtes, in general, to prosthes~s
which are externally attachable to severed or amputated
limbs and, more specifically, to apparatus for use in
attaching prostheses to limbs.
It is common to attach a prosthesis or artificial
limb externally onto a limb of an individual which has been
amputated or otherwise severed in order to provide a measure
of use of the l;mb to the individual. Typically, a strap
and harness assembly is utili~ed which engages the stump of
the limb. During use of the weight bearing limb, such as a
leg or arm, forces are ~enerated which are transmitted
through the prosthesis directly to the flesh surrounding the
stump. Since it is difficult to insure a secure, non-slip
engagement between the prosthesis and the stump, the forces
generated during use of the prosthesis create movement of
the prosthesis relative to the stump which results in irri-
tation of the flesh surrounding the stump and discomfort to
the wearer which makes it difficult, if not impossible, to
effectively use the prosthesis in a normal manner.
One solution to the above-listed problems is set
forth in U S Patent Number 3,947,897. In this device, a
socket is inserted directly into a cavity of the bone at the
end of the stump. The prosthesis is contoured to the shape
of the stump and includes a lock pin insertable within the
socket for releasably mounting the prosthesis to the socket
and stump.
As shown in U.S. Patent Numbers 2,578,019 and
3,186,006, it has nlso proposed to employ cushions or pnds
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which are disposed between the end of the stump and the
prosthesis to absorb and ~ushion some of the forces and
pressures transmitted from the prosthesis to the stump.
While the abovc-described devices reduce to a cer-
tain extent some of the forces transmitted to the stump and
thereby ease some of the discomfort typically encountered
with the use of a prosthesis, such devices fail to evenly
distribllte the forces over the entire end of the stump such
that directional forces still cause pressures to be exerted
on the stump resulting in discomfort to the user.
Thus, it would be desirable to provide an amputa-
tion apparatus which overcomes the problems of previously
devised devices for use with a prosthesis attached exter-
nally to a severed or amputated limb. It would also be
desirable to provide an nmputation apparatus which evenly
distributes the forces exerted by the prosthesis over the
end of the stump to reduce the discomfort caused by such
forces. Finally, it would be desirable to provide an ampu-
tation apparatus which is available in a variety of sizes
for use on different size individuals, from adults to
children, and also to allow for bone and/or flesh growth and
changes in the shape and size of the limb itself.
The present invention is an amputation apparatus
for use with an external prosthesis attachable to the end of
a severed limb or stump. The amputation apparatus includes
a cap having first and second ends, with a cavity formed in
the first end and a boss or projection extending outwardly
from the second end. The cavity in the first end of the cap
is insertable over the end of the bone in the stump and
secured thoreto, prefer~bly by use o~ a bio-compQtible
ndhesive.
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~ plate has a top and bottom surface, with a cavity
formed in the top surface which is interconnectable with the
plug or boss on the cap. A bio-compatible adhesive is uti-
lized to secure the interconnected plug and cavity together
so as to securel~ mount the plate on the cap. The plate is
shaped with nn outer periphery, either circular or oval in
configuration, which has a substantially greater radius than
the radius of the outer periphery of the cap.
With the plate securely mounted on the cap, a loose
strip of skin or skin and muscle is pulled over and wrapped
about the bottom surface of the plate and sutured to the
opposite side of the stump. A cinch strap is secured about
the stump above the plate~ A bandage basket is also mounted
over the stump during the healing of the skin tissue.
In an alternate embodiment, the amputation appara-
tus of the present invention is adapted for use on pre-adult
individuals in which subsequent bone and tissue growth will
occur. In this embodiment, the amputation apparatus is
removably secured to a mesh member which is sutured to the
muscle proximal the end of the stump. In this manner, the
cap and plate assembly may be removed and replaced with a
larger size cap and plate assembly when bone and tissue
growth occurs.
The arnputation apparatus of the present invention
overcomes many of the problems encountered with previously
devised apparatus and methods for attaching prosthesis to
stumps. The amputation apparatus of the present invention
uniquely distributes forces and pressures transmitted from
the prosthesis during its use to the stump in an equnl
30 manrler OVel' the entire bottom surface of the stump.
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Furthermore9 the amputation apparatus distributes body
weight pressure evenly across the stump thus preventing
internal stump damage caused by limb and/or body weight
pressure being borne solely on the bone end. The plate and
cap prevent contact between the bone end and the surrounding
tissue thereby preventing tissue damage caused by grinding
of the bone end into the tissue. This provides greater com-
fort for the user of the prosthesis and prevents irritation
of the flesh surrounding the stump during use of the
prosthesis.
The various features, advantages and other uses of
the present invention will become more apparent by referring
to the following detailed description and drawing in which:
Figure 1 is an exploded, perspective view of an
amputation apparatus constructed in accordance with the
teachings of the present invention;
Figure 2 is a side elevational view of another
embodiment of the plate utilized in the amputation apparatus
of the present invention;
Figure 3 is a side elevational view of yet another
embodiment of the plate utilized in the amputation apparatus
of the present invention;
Figure 4 is a perspective view of the bottom of the
plate utilized in the amputation apparatus of the present
invention showing the construction of the spaced ribs;
Figure 5 is an exploded, partially sectioned view
showing the mounting of the amputation apparatus of the pre-
sent invention externally on the end of the stump; and
Figure 6 is a partial, exploded view showing the
mounting of nnother embodiment of the amputation apparatus
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of the present invention on the end of a stump of a
pre-adult.
Throughout the following description and drawing,
~n identicnl reference number is used to refer to the same
component shown in multiple figures of the drawing.
Referring now to the drawing, there is illustrated
an amputation apparatus 10 which is used with a prosthesis
mountable externally on the end of a stump of a severed or
amputated limb to evenly distribute forces transmitted by
the prosthesis across the stump and internally through the
bone end.
As shown in Figure 1, the amputation apparatus 10
includes a cap 12 and a plate 14. The cap is formed of a
body member constructed of a neutral, bio-compatible
material. The cap 12 typically has a circular cross-section
and is formed with first and second portions 16 and 18,
respectivel~, having different cross-sections or diameters.
The cap 12 is also provided with first and second opposed
ends 20 and 22, respectively.
A recess or internal cavity 24 is formed in the
first end 20 of the first portion 16 of the cap 12. The
cavity 24 extends partially through the first portion 16 of
the cap 12, as shown in Figure 1 and, preferably, has a cir-
cular cross-section.
The second portion 18 of the cap 12, which has a
smaller diameter or cross-section than that of the first
portion 16 of the cap 12, defines a boss or projection which
extends outward from the end of the first portion 16 of the
cap 12. The outor end of the second portion or boss 18
d~finos tho socond end 22 of tho cap 12.
The cap 12 of the present invention may be formed
in a vuriety of sizes corresponding to minimal O.D., so as
to enable its use on a variety of different sized indivi-
duals and to allow removal and exchange of the cap 12 for
bone and tissue growth during the life of the user.
Furthermore, the boss 18 and cavity 24 may have different
diameters than that illustrated in Figure I to accomodate
varying plate sizes, described hereafter, as well as dif-
ferent stump diameters.
As shown in Figure 1, a plurality of elevator mem-
bers 26 are removably insertable within the cavity 24 within
the cap 12. The elevator members 26 are circular discs
having a cross-section equal to the cross-section of the
cavity 24. Any number of elevators 26 may be inserted
within the cavity 24 in the cap 12 to permit variation in
the attachment of the cap 20 on the end of the bone of the
stump, as described and illustrated hereafter.
The amputation apparatus 10 of the present inven-
tion also includes a plate 14 in the form of a thin body
formed of a neutral, bio-compatible material. The plate 14
is formed with opposed, top and bottom surfaces 3~ and 32,
respectively. Preferably, the plate has a cup-like con-
figuration including an upwardly extending side wall 34.
Preferably, the side wall 34 is formed with rounded or
smooth corners to prevent tissue damage when the plate 14 is
mounted on the end of a stump of a severed or amputated leg.
As shown in Figure 1, the radial extent of the
periphery of the plate 14 is substantially greater than the
corresponding radial extent of the periphery of the cnp 12
such that thc side wall 34 of the plate 14 e~tends a
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substantial radial distance outward beyond the outer
peripheral surface of the cap 12 so as to define a large
weight bearing surface. The plate 14 may be formed in any
desired conf igurAt ion, although circular or oval con-
figurations are preferred.
A cavity or recess 36 is formed in the plate 14 and
has a diameter which mates with the boss 18 on the cap 12 so
as to snugly be inserted over the periphery of the boss 18.
In the embodiments shown in Figures 1 and 2, a
second boss or projection 3~ is formed integrally with and
extends upward from the top surface 30 of the plate 1~ above
the upper end of the side wall 34. The internal cavity 36
is formed within the boss 38 and, in one embodiment shown in
Figure 1, extends through a portion of the depth of the boss
38. In a second embodiment illustrated in Figure 2, the
internal cavity 36' extends through the entire length of the
boss 38 into the interior of the plate 14. Alternate}y, as
shown in Figure 3, the boss 38' may extend upward only a
portion of the height of the side wall 34 of the plate 14.
As shown in Figures 1-4, rib means 40 are formed on
the plate 14. The rib means 40 functions to provide a
holding surface for the surrounding skin and tissue after
the plate 14 is installed upon an end of a stump to securely
hold the plate 14 in position on the end of the stump and to
provide space for post-operative tissue swelling.
In a preferred embodiment, the rib means 40 com-
prises a plurality of concentric, annular ribs, such as ribs
41, 42 and 43, which are integrally formed on the plate 14.
As shown in Figures 1-4, the ribs 41, 42 nnd 43 comprises
corrug~tions formed in the plate 1~ which encircle the boss
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38. Alternately, the rib means 40 may comprise a plurality
of annular flanges mounted on the top and/or bottom surfaces
30 and 32 of the plate 14.
As shown in Figure 5, the amputation apparatus 10
of the present invention is adapted to be disposed over and
connected to the end of the bone 50 located at the end of a
stump 52 of a severed or amputated limb. The cap 12 is
inserled directl~ over the end of the exteriorally
extending, exposed portion of the bone 50 with the internal
cavity 24 formed in the first end 20 of the cap 12 snugly
engaging the bone 50.
Securing means, such as a bio-compatible adhesive,
is disposed between the mating surfaces of the cavity 24 and
the bone 50 so as to securely mount the cap 12 of the end of
the bone 50.
The plate 14 is then mounted directly on the out-
wardly extending plug or boss 18 on the cap 12. In so
doing, the internal cavity 36 on the plate 14 is disposed
directly over the plug or boss 18 on the cap 12 and secured
theretc by a suitable adhesive. In this way, the cap 12 and
plate 14 are securely mounted on the bone 50.
Prior to the installation of the amputation appara-
tus 10 of the present invention on the end of a bone on a
stump, the stump 50 is prepared for attachment of the ampu-
tation apparatus 10. An incision is made through the skin
which is separated from the muscles and peeled back to a
point approximately two times the diameter of the plate 14
above the end of the bone 50. The muscles are then excised
around the bone 50 and the bone erld itself is cleaned. The
cap 12 i8 thcn mounted in position and bonded to the end of
the bone 50. Next, the plate 1~ is securely mounted to the
cap 12, as described above.
The skin 54 from one side of the stump 52 is then
brought down and across the bottom surface 32 of the plate
14 and up to the opposed side 56 of the stump 52. The skin
portion 54 may be selected from either the front or back of
the stump 52, as well as from either the left or right sides
of the stump 52.
A cinch strap 57 in the form of an elongated strip
member is secured about the stump 52 above the plate 14.
The cinch strap 57 draws the skin in around the bone 50 and
the cap area, as shown in phantom in Figure 5, to f~cilitate
the attachment of an external device or prosthesis. Any
excess skin folds created by the cinching may be surgically
excised to further enhance the fit of an external device
and/or prosthesis.
As shown in Figure 5, a bandage basket 66 con-
taining bandages or to hold bandages, not shown, disposed
about the stump 52 is then mounted over the end of the stump
52. The bandage basket 66 is formed of a flexible, large-
opening, weaved container having an open top end 68. The
configuration or cross-section of the bandage basket 68 is
compatible with that of the plate 14 and may be either cir-
cular or oval in cross-section. Two flexible hanger straps
70 and 72 mounted on the basket 66 are criss-crossed in front
of the basket 66 and interconnected by means of a pin 'l4
attached to the bandage basket 66, to securely hold the
basket 66 in position on the stump 52 during the skin and
tissue healing process.
After the skin has properly healed, the bandage
basket 66 and cinch strap 57 are removed from the stump 52
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and a suitable prosthesis or other external device, not
shown, can then be mounted on the stump 52.
During use of the prosthesis, the plate 14, which
defines a large weight bearing surface at the end of the
bone 50 of the stump 52, will evenly distribute forces
transmitted by the prosthesis over the entire bottom surface
of the bone 50 and the stump 52~ This has the effect of
equally distributing such forces so as to prevent any inter-
nal or external directional forces from being urged on the
stump 52 which could cause discomfort to the user.
Referring now to Figure 6, there is illustrated an
alternate embodiment of the amputation apparatus of the pre-
sent invention. In this embodiment, the amputation appara-
tus 80 is shown mounted on the end of the stump of a pre-
adult individual in which future bone and tissue growth will
occur. The amputation apparatus 80 includes a member 82
formed of a mesh-like material which is sutured to the
muscle surrounding the end of the stump. An outer layer 85
is provided on the mesh member 82 and includes a hole pat-
tern 84 which provides a location for sutures used to attach
the mesh member 82 to the muscle.
The mesh member 82 includes a lower centrallg
located depending portion 86 which is adapted to releasably
receive the cap thereon, as described hereafter.
The amputation apparatus 80 also includes a cap 88
and a plate 90. The cap 90 is formed of a su;tab}e bio-
compatible metallic material and has a circular cross-
section with a first recess or cavity 92 formed at an upper
end. A layer of a compressable material 9~ is disposed
interiorally within the fir~t recess 92 nnd is ndnpted to
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surround and engage the end of the bone of the stump. A
boss or projection 96 is formed on the second end of the cap
88 for receiving the plate 90 thereon, in the same manner as
described and illustrated above for the amputation apparatus
10.
The plate assembly 90 is identically formed as that
illustrated in Figure 1 such that a detailed description
wil} not now be provided. It will be understood, however,
that the plate 90 is secured to the boss 96 on the cap 88 bg
means of an adhesive as described above.
The cap 88 is releasably secured to the bottom end
86 of the mesh member 82 by means of a cable connector 98
which is releasably insertable into arcuate~ depending
figures 100 formed at the upper end of the cap 88.
Insertion of the cable connector 98 within the interior of
the depending figures 100 secures the cap 88 to the
depending end 86 of the mesh member 82 to thereby securely
and releasably mount the amputation apparatus 80 of the pre-
sent invention on the end of the bone of the stump. When
bone and tissue growth occurs the cable 98 may be removed so
as to detach the plate 90 and cap 88 from the end of the
bone of the stump and allow the installation of a larger
sized cap and plate assembly.
In summary7 there has been disclosed a unigue ampu-
tation apparatus which evenly distributes internal and
external forces across the entire bottom surface of the
stump. The amputation apparatus of the present invention is
easily installed and secured on the end of the bone in the
stump. The amputation npparatus of the present invention
may, also, be provided in a variety of sizes so RS to ennble
its application on many different sized individuals, a5 well
as replacement to allow for bone and tissue growth.
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