Patent GB2139097A successfully refreshed from Google Patents.
GB2139097A
Expired / Lapsed
GB
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Implantable joint prosthesis
Assignee: Individual
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Filing: 1984-05-08
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Granted: —
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Expires: 2004-05-08
Abstract
Abstract A prosthesis including a load receiving surface for receiving a load applied to the prosthesis, a first surface provided with interlocking means for interlocking fixation of a first bone portion and for transferring a portion of the applied load to the first bone portion, and a second surface which is smooth to cause an increase in the portion of the applied load applied to the first bone portion to increase the stress produced therein thereby substantially reducing stress shielding in the first bone portion and resorption of bone therein. <IMAGE>
Inventors
- 👤 Frederick F Buechel
- 👤 Michael J Pappas
Bibliographic Details
Application Number
—
Jurisdiction
GB
Data Source
google_patents
Last Synchronized
2026-11-08 21:11
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/40; A61F2/4003; A61F2/32; A61F2/36; A61F2/3601; A61F2/3603; A61F2/30767; A61F2/3662; A61F2/367; A61F2/3676; A61F2002/30001; A61F2002/30316; A61F2002/30317; A61F2002/30322; A61F2/30771; A61F2002/30878; A61F2/3609; A61F2002/3611; A61F2002/3625; A61F2002/3631; A61F2002/4007; A61F2/4014; A61F2002/4018; A61F2/4059; A61F2002/4062; A61F2002/4077; A61F2/46; A61F2002/4631; A61F2250/00; A61F2250/0014; A61F2250/0026; A61F2310/00; A61F2310/00005; A61F2310/00011; A61F2310/00017; A61F2310/00023; A61F2310/00029; A61F2310/00389; A61F2310/00395; A61F2310/00407; A61F2310/00413; A61F2310/00592
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
239 words
In a prosthesis for interlocking fixation to a
bone, wherein the prosthesis includes a load receiv
ing surface for having a load applied thereto, a first
predetermined surface in interlocking fixation with a
first bone portion and for transferring a first portion
of said load to said first bone portion producing
stress therein, a second predetermined surface in
interlocking fixation with a second bone portion and fortransferring a second portion of said load to said
second bone portion, said first predetermined sur
face and said first bone portion respectively near
said load receiving surface and said second prede
termined surface and said second bone portion,
whereby stress shielding is produced in said first
bone portion due to said interlocking fixation be
tween said second pre-determined surface and said
second bone portion which reduces said first portion
of said load transferred to said first bone portion by
said first predetermined surface,
WHEREIN THE IMPROVEMENT COMPRISES::
said second predetermined surface being smooth
to substantially eliminate said interlocking fixation
between said second predetermined surface and
said second bone portion thereby reducing the
portion of said applied load transferred to said
second bone portion by said second predetermined
surface thereby increasing the portion of said ap
plied load transferred to said first bone portion by
said first predetermined surface thereby increasing
said stress produced in said first bone portion to
substantially reduce said stress shielding therein
and resorption of said first bone portion.
Claim 2
Dependent Claim
239 words
In a prosthesis for interlocking fixation to a
bone, wherein the prosthesis includes a load receiv
ing surface for having a load applied thereto, a first
predetermined surface in interlocking fixation with a
first bone portion and for transferring a first portion
of said load to said first bone portion producing
stress therein, a second predetermined surface in
interlocking fixation with a second bone portion and fortransferring a second portion of said load to said
second bone portion, said first predetermined sur
face and said first bone portion respectively near
said load receiving surface and said second prede
termined surface and said second bone portion,
whereby stress shielding is produced in said first
bone portion due to said interlocking fixation be
tween said second pre-determined surface and said
second bone portion which reduces said first portion
of said load transferred to said first bone portion by
said first predetermined surface,
WHEREIN THE IMPROVEMENT COMPRISES::
said second predetermined surface being smooth
to substantially eliminate said interlocking fixation
between said second predetermined surface and
said second bone portion thereby reducing the
portion of said applied load transferred to said
second bone portion by said second predetermined
surface thereby increasing the portion of said ap
plied load transferred to said first bone portion by
said first predetermined surface thereby increasing
said stress produced in said first bone portion to
substantially reduce said stress shielding therein
and resorption of said first bone portion.
Claim 3
Dependent Claim
131 words
A prosthesis according to Claim 1 wherein
said prosthesis is a surface replacement prosthesis
and wherein said load receiving surface is an
exterior surface for replacing an articular surface of
the bone, and wherein said first predetermined
surface is a porous coated upper interior prosthetic
surface of predetermined shape for direct bone
ingrowth interlocking fixation of said prosthesis to
said bone and wherein said second predetermined
surface is the smooth outer surface of a member extending outwardly from said interior surface and
which smooth outer surface is for preventing inter
locking fixation between said prosthesis and said
bone, said member also for providing initial and
secondary fixation of said prosthesis to said bone,
for aligning said prosthesis with said bone and for providing fracture resistance of said bone across said member.
Claim 4
Dependent Claim
78 words
A prosthesis according according to Claim 5 wherein said surface replacement prosthesis is a hip surface replacement prosthesis, wherein said exterior surface is smooth and spherical and wherein said porous-coated upper interior surface is defined by a flat central portion continuing into a spherical portion concentric with said smooth spherical ex teriorsurface and continuing into a cylindrical portion and wherein said member is a longitudinally extending stem extending from said interior surface perpendicular to said flat central portion.
Claim 5
Dependent Claim
75 words
A prosthesis according to Claim 5 wherein said prosthesis is a humeral surface replacement prosthesis wherein said exterior surface is spherical and smooth and wherein said interior surface is defined by a flat central portion continuing into a spherical portion concentric with said smooth spherical exterior surface and continuing into a cylindrical portion and wherein said member is a longitudinally extending stem extending from the interior of the prosthesis perpendicular to said flat central portion.
Claim 6
Dependent Claim
107 words
A prosthesis according to Claim 1 wherein said prosthesis is a femoral stem prosthesis having a spherical head at its upper portion for replacing the articular surface of the femur and said spherical head providing said load receiving surface, said femoral stem prosthesis having a downwardly extending stem for implantation to the intramedullary canal of the femur, wherein said first predetermined surface is a porous coated upper portion of said stem for direct bone ingrowth interlocking fixation between said prosthesis and said femur and wherein said second predetermined surface is a smooth lower portion of said stem for preventing interlocking fixation between said prosthesis and said bone.
Claim 7
Dependent Claim
107 words
A prosthesis according to Claim 1 wherein said prosthes is a humeral stem prosthesis having a spherical head at its upper portion for replacing the articular surface of the humerus and said spherical head providing said load receiving surface, said humeral stem prosthesis having a downwardly extending stem for implantation to the intramedullary canal of the humerus, wherein said first predetermined surface is a porous coated upper portion of said stem for direct bone ingrowth interlocking fixation between said prosthesis and said humerus and wherein said second predetermined surface is a smooth lower portion of said stem for preventing interlocking fixation between said prosthesis and said bone.
Claim 8
Dependent Claim
97 words
A prosthesis for implantation into a bone, comprising:
a first portion and a stem, said first porion providing a cavity and said stem being tapered for driving implantation into the bone to wedge a bone portion into the cavity to provide at least initial fixation of the prosthesis to the bone and to place the wedged bone portion in a state of compression, said stem being smooth to substantially prevent inter
locking fixation between said stem and said bone which in combination with said bone portion being
in said state of compression substantially eliminates stress shielding thereof.
Claim 9
Dependent Claim
97 words
A prosthesis for implantation into a bone, comprising:
a first portion and a stem, said first porion providing a cavity and said stem being tapered for driving implantation into the bone to wedge a bone portion into the cavity to provide at least initial fixation of the prosthesis to the bone and to place the wedged bone portion in a state of compression, said stem being smooth to substantially prevent inter
locking fixation between said stem and said bone which in combination with said bone portion being
in said state of compression substantially eliminates stress shielding thereof.
Claim 10
Dependent Claim
70 words
A prosthesis according to Claim 7 wherein said bone is provided with a hole, wherein said first portion is provided with a generally concave interior surface, wherein said tapered stem extends generally centrally from said concave interior surface, wherein said cavity is generally annular and resides between the upper portion of the tapered wedge and said concave interior surface, said tapered wedge being larger in diameter than said bone hole.
Claim 11
Dependent Claim
20 words
A prosthesis according to Claim 8 wherein said first portion is generally cap shaped having a generally spherical outer surface.
Claim 12
Dependent Claim
15 words
A prosthesis according to Claim 9 wherein said prosthesis is a femoral surface replacement prosthesis.
Claim 13
Dependent Claim
15 words
A prosthesis according to Claim 9 wherein said prosthesis is a humeral surface replacement prosthesis.
Claim 14
Dependent Claim
31 words
A prosthesis substantially as herein described with reference to Figures 3A, 3B and 3C,
Figures 4A and 4B, Figure 5, Figure 6, Figure 7, or
Figure 8 of the accompanying drawings.
Claim 15
Dependent Claim
31 words
A prosthesis substantially as herein described with reference to Figures 3A, 3B and 3C,
Figures 4A and 4B, Figure 5, Figure 6, Figure 7, or
Figure 8 of the accompanying drawings.
References Cited (Backward Citations)
EP0038902A2
Cited
EP0094743A1
Cited
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