U.S. patent number 3,813,699 [Application Number 05/323,828] was granted by the patent office on 1974-06-04 for prosthetic hip joint.
Invention is credited to Richard P. Giliberty.
United States Patent |
3,813,699 |
Giliberty |
June 4, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
PROSTHETIC HIP JOINT
Abstract
A prosthetic device and more particularly a hip-joint prosthesis
having a fully assembled composite structure of a femoral head,
neck and shank to be positioned in and on the femur, a cup for
positioning in the acetabulum for relative articulation therein to
closely approximate the anatomical function of the natural femur
head and acetabulum joint with the femoral head and cup being
connected with each other to restrain their separation, but to
permit their relative movement.
Inventors: |
Giliberty; Richard P.
(Manhasset, NY) |
Family
ID: |
23260901 |
Appl.
No.: |
05/323,828 |
Filed: |
January 15, 1973 |
Current U.S.
Class: |
623/22.17 |
Current CPC
Class: |
A61F
2/32 (20130101); A61F 2310/00029 (20130101); A61F
2002/3466 (20130101); A61F 2002/3233 (20130101); A61F
2002/3493 (20130101); A61F 2002/3611 (20130101); A61F
2002/3208 (20130101); A61F 2002/3625 (20130101); A61F
2002/3631 (20130101); A61F 2/36 (20130101) |
Current International
Class: |
A61F
2/32 (20060101); A61F 2/00 (20060101); A61F
2/34 (20060101); A61F 2/36 (20060101); A61f
001/24 () |
Field of
Search: |
;3/1
;128/92C,92CA,92R |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1,047,640 |
|
Jul 1953 |
|
FR |
|
1,215,737 |
|
Dec 1970 |
|
GB |
|
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Frinks; Ronald L.
Attorney, Agent or Firm: Bauer & Amer
Claims
What is claimed is:
1. A hip-joint prosthesis comprising a replacement member having a
substantially spherical head for placement in articulating relation
to an acetabulum opening,
an inner cup fabricated of material of low frictional resistance
having a substantially spherical wall bounding a chamber of a
corresponding substantially spherical shape and size in relation to
that of said head and disposed in covering relation thereover so as
to permit initial articulating traverses of comparatively large
extent between said head and said inner cup substantially
duplicating the movements of the femur head relative to the
acetabulum,
and an outer cup fabricated of a metal alloy which is inert when
disposed in live body tissue, said outer cup being disposed in
covering fixed relation over said inner cup and having an unbroken,
continuously smooth outer spherical cup surface free of radial
projections and interruptions for allowing substantially universal
articulating traverses within the acetabulum opening.
2. A hip-joint prosthesis as defined in claim 1 wherein said outer
and inner cups have an annular wall section bounding the opening
into said chamber thereof which is adpated to holdingly engage said
spherical head against withdrawing movement therefrom.
3. A hip-joint prosthesis as defined in claim 2 wherein said
fabrication material of said inner cup is a resilient plastic, such
that the assembly of said metal outer cup and said inner plastic
cup is adapted to snap in place over said spherical head.
4. A hip-joint prosthesis as defined in claim 3 wherein said inner
cup is a polyethylene.
5. In a prosthesis for replacing at least part of a body joint
comprising, in combination,
a substantially spherical head member for placement in articulating
relation in a joint opening,
a socket for said head,
said socket having a continuously smooth unbroken outer
substantially spherical surface, free of radial projections and
interruptions for allowing substantially universal articulating
traverses within the joint opening,
said socket and head including cooperating means connecting said
socket to and about said head for relative movement but to prevent
relative separation thereof,
and a low friction liner between said head and socket to permit
relative movement between said head and socket and including means
to connect the same to said head to prevent the relative separation
thereof.
6. In a prosthesis as defined in claim 5 wherein said liner is
fabricated of a material having a low friction surface.
7. In a prosthesis as defined in claim 6 wherein said cooperating
means connecting said socket, liner and head comprises interfitting
substantially spherical shapes permitting the insertion of said
liner within said socket and said head within said liner.
8. In a prosthesis as defined in claim 7 wherein said fabrication
material of said liner is a resilient plastic such that the
assembly of said socket and said liner is adapted to snap in place
over said head.
9. In a prosthesis as defined in claim 8 wherein said liner is
polyethylene.
10. A hip-joint prosthesis comprising a femur stem, a femur
configured head, and a neck narrower than said stem and head
intermediate the same to connect said head and stem together,
a cup having an unbroken, continuously smooth outer surface free of
projections and interruptions for insertion into and for allowing
substantially universal traverses within an acetabulum opening,
a liner of inert low-friction material retained in said cup against
removal therefrom,
said liner having a socket defined therein,
said head being movable within and relative to said socket,
said socket having a smooth surface shaped to correspond with that
of said head and said socket terminating in narrowed opening
engageable with and about said head adjacent said narrower neck to
restrain the withdrawal of said head from said socket through said
opening.
Description
BACKGROUND OF THE INVENTION
Since arthroplasty was first introduced in about 1827, many
surgical procedures have been attempted to produce the ideal
pseudarthosis. These encompassed attempts to create artificial
joints which would closely meet the anatomical function of the
pre-existing diseased part and still be relatively painless. Such
recent attempts are exemplified by United States Letters Patent to
Scales et al U.S. Pat. No. 3,584,318, Haboush U.S. Pat. No.
2,668,531 and U.S. Pat. No. 3,067,740.
Prior attempts at the creation of artificial joints have included
the provision of artificial femur heads and acetabulum sockets
replacing the originals. Unfortunately, erosion and arthritis that
sometimes takes place between the artificial insert and the body
causes a mal relationship that produces new and additional
problems. To overcome such problems, attempts have been made to
cover the acetabulum with protective cups or shields which have
been fastened to the acetabulum by pins, glue or other securing
means.
The surgical procedures are complicated, time consuming and often
performed at different times and require approximately 2 to 3 hours
to perform during which the mortality or morbidity rate is high.
Oftentimes the functioning of the resultant joint still does not
permit a smooth movement between the head and the secured
acetabulum to any great extent especially after a reasonable period
of time.
SUMMARY OF THE INVENTION
The present invention is directed to a prosthetic device and more
particularly to a hip-joint prosthesis although not specifically
limited thereto.
An object of the invention is to provide a prosthesis that may be
substituted for and to take the place of the natural anatomic
structure and perform the same functions in substantially the same
manner as such replaced structures were intended to perform.
Another object of the invention is to provide a prosthesis which is
a composite of essentially non-separable parts capable of
substantially frictionless articulation. In carrying out the above,
an object and feature of the invention resides in the composite
arrangement of detailed structures which enable a smooth cup to be
inserted into relative articulating contact with the acetabulum
while a femur head is retained within the cup and permitted
substantially frictionless articulation relative to the cup.
Still a further object is to provide a prosthesis of assembled
details that may be installed and substituted for the related
anatomy in a single surgical procedure, in a fraction of the time
required for prior similar surgical procedures to thereby reduce
the mortality an morbidity rate.
It is another object of the present invention to provide an
improved hip-joint prosthesis overcoming the shortcomings of the
prior art. Specifically, it is an object to provide an artificial
hip-joint prosthetic device in which a cup is utilized for touching
and articulating engagement with the acetabulum, thereby avoiding
the pinning, gluing and other securing means that have been
utilized and taught in the prior art. Further, the femur head is
permitted relative substantially frictionless articulation within
the cup while the head and the cup are restrained from relative
separation, thereby permitting the surgical procedure to be
accomplished all at one time and enabling alternate articulation
between the head and the cup in the event the cup and the
acetabulum should for some reason become restricted in their
articulation.
The above description, as well as further objects, features and
advantages of the present invention, will be more fully appreciated
by reference to the following detailed description of a presently
preferred, but nonetheless illustrative, embodiment in accordance
with the present invention, when taken in conjunction with the
accompanying drawings, wherein:
FIG. 1 is a partial perspective view illustrating the prosthetic
device as applied to the hip joint according to the teaching of the
present invention;
FIG. 2 is an isolated front elevational view, on an enlarged scale,
of the prosthetic device in its unassembled condition; and
FIG. 3 is a partial front elevational view, similar to FIG. 2,
illustrating the prosthetic device in its assembled condition.
Referring to the drawing, the composite prosthetic device there
shown is generally identified by the numeral 10. Throughout the
description, reference will be made to the use of the prosthesis 10
in connection with a hip 12 and more particularly to the acetabulum
socket 14. This description should not constitute a limitation upon
the scope of the invention. The reference of the prosthetic device
10 for use in connection with the hip is merely to enable a simple
and easy explanation of the invention. Obviously, the invention may
be applied to other body parts and is equally applicable in
veterinary uses.
The prosthetic device 10 comprises a femoral insert adapted to take
the place of the damaged or diseased femur head. The insert is
generally identified by the numeral 16 and comprises a stem 18 that
is adapted to be forced into the femur after the natural head of
the femur has been removed. The stem 18 is provided with an
enlarged stop or positioning shoulder 20 that merges with a
narrowed neck 22 that extends between the stem 18 and a substitute
head 24. Because the narrowed neck 22 is intermediate the stem and
the head 24, it joins the two parts together to form a single
structure. The overall femur insert structure 16 may be made of any
well known metallic material that is inert and that is commonly or
conventionally utilized for these purposes. The specific nature or
composition of such material forms no part of this invention,
although Vitallium has been conventionally employed for such
purposes.
The head 24 is substantially spherical in shape narrowing toward
the neck 22, beyond its diametral line 26. The overall femur insert
16 may be made as a unitary, nonseparable structure which may be
cast, machined or forged if desired, the method of construction
being immaterial for the purposes of the present invention.
Cooperating with the femur insert 16 is a universally movable
acetabulum insert cup generally identified by the numeral 28. The
acetabulum cup 28 is formed as a unitary structure and comprises an
outer cup member or liner 30 and an inner cup or liner 32. The
elements 30 and 32 are joined together either by lamination, gluing
or any other convenient securing means to form the unitary overall
acetabulum insert cup structure 28. The outer cup or liner 30 is
made of a highly polished, inert metal, such as Vitallium. Its
outer surface, being highly polished, free of radial projections
and interruptions is essentially and substantially spherical in
shape to enable the same to be moved substantially universally
within a corresponding opening or socket that may be subsequently
provided at the acetabulum socket 14. The inner liner 32 is bonded
or adhered throughout its surface adjacent to and in engagement
with the outer liner 30 so that they form a unitary structure
incapable of relative separation or movement. The means for
accommodating or enabling such relative securement between the
liners 30 and 32 forms no part of the present invention.
The inner liner 32 is composed of a material having low frictional
resistance and apparent high lubricating characteristics. Such
materials as silicone, polyethylene and polyfluroethylene are
inert, resilient plastics that may be machined, molded and shaped
congruent to that of the interior surface of the outer cup or liner
30. The interior of the inner cup or liner 32 thus presents a very
smooth essentially spherical surface 34 of high lubricity and,
therefore, low substantially frictionless engagement with the
highly polished surface of the femur head 24 when the femur head 24
is inserted into the acetabulum insert cup structure 28 as seen in
FIG. 3. Thus, the interface established between the head 24 and the
lubricating liner 32 provides a universal joint having very low,
substantially frictionless characteristics.
Both cup or liner members 30 and 32 extend beyond a diametral line
36 defining the substantially and essentially spherical shape of
the interior of the cup structure 28. The extension of the overall
cup structure 28 beyond the diametral line 36 includes both the
outer cup 30 as at 38 and the inner cup 32 as at 40. The inner cup
32 is narrowed at the extension 40 such as is shown by the wall 42
to form a constricted opening 44 which defines an entranceway into
the interior of the acetabulum insert cup structure 28. The
bounding outer wall 38 prevents the inner wall from resiliently
expanding but does not inhibit the wall 42 from yielding to enable
the insertion of the head 24 into and out of the cup 32.
In practice, the cup structure 28 is formed independently of the
femur insert 16. However, before use, the femur insert head 24 is
positioned within the cup structure 28 so that both elements are
connected together against relative separation for use as a unitary
or composite prosthetic device 10. In this connection although the
opening 44 of the acetabulum insert cup structure 28 is narrower in
diameter than the widest diameter extending across the diametral
line 26 of the head 24, the nature of the silicone liner wall 42 is
such that the same yields slightly under pressure, restricted by
the wall 38, and thus upon the application of lengthwise pressure,
the cup and the head 24 may be joined together by forcing the head
24 through the opening 44 bordered by the wall 42 and then into the
confines of the socket defined by the surface 34. The head is
retained within the socket of the inner cup liner 32 because of the
constricted size of the opening 44 and the insert 16 and the cup
structure 28 are restrained and normally prevented from relative
accidental subsequent separation. Obviously, a surgeon may separate
the two structures 16 and 28 should he find the same necessary, but
in normal use the composite of the inserts 16 and 28 form a unitary
prosthetic device 10.
The connection of the two inserts 16 and 28 is illustrated in FIG.
3. It should be obvious to those skilled in the art that the
connection formed between the highly polished, smooth metallic head
24 and that of the surface 34 of the acetabulum insert cup
structure 28 permits substantially frictionless universal movement
between the femur stem and the acetabulum if and when the outer
surface of the outer cup or liner 30 is positioned within the
acetabulum socket 14 and restricted or restrained from movement
relative thereto. Such relative movement between the head 24 and
the surface 34 is enhanced and facilitated in a substantially
frictionless manner because the inner liner 32 is formed of a very
smooth, high lubricity material.
In practice, the femur stem 18 is inserted by being pressed into
the femur 46 as seen in FIG. 1 after the natural femur head has
been removed. The stem is inserted as deep as the shoulder 20 will
permit. Thereafter, the acetabulum socket 14 is reamed or shaped by
the surgeon to conform it substantially congruent to that of the
outer highly polished surface of the outer liner or cup 30, which
is then placed within such shaped socket. All of this is performed
in single operation without the need to pin, glue, bolt or
otherwise secure the cup 30 to the acetabulum. The operation is
quite simple and can be performed in a single procedure reducing
mortality and morbidity to a very low rate.
When the surgical procedure is completed, the acetabulum insert cup
structure 28 is permitted relative universal movement with respect
to the acetabulum socket 14 which has been shaped thereto. It is
recognized that the body tends to reject the prostethic device 10
in some instances, in other instances disease and erosion as well
as the accumulation of cartilage and other body accumulations may
restrict the continued free movements of the femur 46 relative to
the hip 12 at the interface between the outer surface of the outer
cup 30 and the socket 14. In such instances, a secondary or
alternate movement is permitted at the interface between the head
24 and the highly lubricated surface 34. Hence, in spite of the
fact that the acetabulum insert cup structure 38 may subsequently
become locked, or restricted and perhaps even totally immovable
relative to the acetabulum socket 14 at the interface therebetween,
continued, unrestricted, substantially universal movement of the
femur 46 is permitted between the head 24 and the lubricating liner
32.
The interface movement between the head 24 or femur 46 and the
liner 32 or hip 12 is of such nature as to last substantially
indefinitely. With the prosthesis 10 surgically positioned as
described, forces of motion of the hip 12 are divided over large
surface areas. When the stress is greater than that able to be
absorbed by the interface between the head 24 and liner 32, such
forces are further distributed by motion afforded by the interface
between the outer smooth surface of the cup 30 and the acetabulum
socket 14.
What has been provided is a unique prosthetic device that may be
applied in a single surgical procedure, within a relatively short
time and which will permit its continued use without securing the
same to the acetabulum. And even long after the body may erode or
produce constrictions to movement that might normally occur at the
interface between the acetabulum 14 and the acetabulum insert cup
structure 28, movement is enabled at the interface of the cup 28
with the head 24.
While there have been shown and described and pointed out the
fundamental novel features of the invention as applied to a
preferred embodiment thereof, it will be understood that various
omissions and substitutions and changes in the form and details of
the device illustrated and in its operation may be made by those
skilled in the art without departing from the spirit of the
invention. It is the intention, therefore, to be limited only as
indicated by the scope of the claims appended thereto.
* * * * *