US3925824A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Endoprosthetic bone joint devices
Assignee: National Research Development Corp UK
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Filing: 1974-05-09
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Granted: 1975-12-16
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Expires: 1994-05-09
Abstract
Abstract A hip joint prosthesis is provided with a socket member for the acetabular cavity and a cap member for the femoral head, both members being formed with grooves for fixation to exposed cancellous bone in association with gap-filling medium. The cap member has a major-spherical-segment outer bearing surface, and a coaxial cylindrical inner fixation surface with axial and circumferential grooves to receive said medium. The socket member has a spherically shaped inner bearing surface of not more than hemispherical extent to articulate with the cap member, and an outer fixation surface of hemispherical shape with coaxial annular grooves to receive said medium. The socket and cap members can be respectively of metal and plastics material, in which case the socket is of relatively thin, regular hemispherical form; or these materials can be reversed in which case the socket bearing surface is of minor-spherical-segment shape and can be eccentric to its fixation surface to provide greater thickness remote from its mouth.
Inventors
- 👤 Michael Alexander Reyk Freeman
- 👤 Sydney Alan Vasey Swanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:11
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/32; A61F2/36; A61F2/3601; A61F2/3603; A61F2/34; A61F2/30767; A61F2/30771; A61F2002/3082; A61F2002/30827; A61F2002/30828
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
173 words
An endoprosthetic hip joint device comprising: an acetabular component in the form of a socket member having an inner bearing surface concavely spherically shaped to not more than hemispherical extent, and a hemispherically shaped outer fixation surface formed with a shallow relieved configuration, said socket member being formed of metal with its inner and outer surfaces both being substantially hemispherical and concentrically located to define a thin uniform thickness therebetween, and a femoral component in the form of a cap member having an outer bearing surface of convex majorspherical-segment shape in complementary, mutually articulatory engagement with said inner bearing surface, and a concave inner fixation surface of generally cylindrical shape coaxial with the axis of symmetry of said outer bearing surface and formed with a shallow relieved configuration, said cap member being formed of a plastic material of significantly greater thickness between its respective inner and outer surfaces than said acetabular component; both of said fixation surfaces having relieved formations for receiving gap-filling medium in respective direct securement with the acetabulum and femur.
Claim 2
Dependent Claim
173 words
An endoprosthetic hip joint device comprising: an acetabular component in the form of a socket member having an inner bearing surface concavely spherically shaped to not more than hemispherical extent, and a hemispherically shaped outer fixation surface formed with a shallow relieved configuration, said socket member being formed of metal with its inner and outer surfaces both being substantially hemispherical and concentrically located to define a thin uniform thickness therebetween, and a femoral component in the form of a cap member having an outer bearing surface of convex majorspherical-segment shape in complementary, mutually articulatory engagement with said inner bearing surface, and a concave inner fixation surface of generally cylindrical shape coaxial with the axis of symmetry of said outer bearing surface and formed with a shallow relieved configuration, said cap member being formed of a plastic material of significantly greater thickness between its respective inner and outer surfaces than said acetabular component; both of said fixation surfaces having relieved formations for receiving gap-filling medium in respective direct securement with the acetabulum and femur.
Claim 3
Dependent Claim
184 words
An endoprosthetic hip joint device comprising: an acetabular component in the form of a socket member having an inner bearing surface concavely spherically shaped to not more than hemispherical extent, and a hemispherically shaped outer fixation surface formed with a shallow relieved configuration, said inner bearing surface being of a minor spherical segment shape coaxial with said outer fixation surface, but having its spherical center displaced from that of said outer fixation surface to provide said socket member with the greatest thickness remote from its mouth, said socket member being formed of an integral plastic material; and a femoral component in the form of a cap member having an outer bearing surface of convex majorspherical-segment shape in complementary mutually articulatory engagement with said inner bearing surface, and a concave inner fixation surface of generally cylindrical shape coaxial with the axis of symmetry of said outer bearing surface and formed with a shallow relieved configuration, said cap member being formed of a metal material; both of said fixation surfaces having relieved formations to receive gap-filling medium in respective direct securement with the acetabulum and femur.
Claim 4
Dependent Claim
184 words
An endoprosthetic hip joint device comprising: an acetabular component in the form of a socket member having an inner bearing surface concavely spherically shaped to not more than hemispherical extent, and a hemispherically shaped outer fixation surface formed with a shallow relieved configuration, said inner bearing surface being of a minor spherical segment shape coaxial with said outer fixation surface, but having its spherical center displaced from that of said outer fixation surface to provide said socket member with the greatest thickness remote from its mouth, said socket member being formed of an integral plastic material; and a femoral component in the form of a cap member having an outer bearing surface of convex majorspherical-segment shape in complementary mutually articulatory engagement with said inner bearing surface, and a concave inner fixation surface of generally cylindrical shape coaxial with the axis of symmetry of said outer bearing surface and formed with a shallow relieved configuration, said cap member being formed of a metal material; both of said fixation surfaces having relieved formations to receive gap-filling medium in respective direct securement with the acetabulum and femur.
Claim 5
Dependent Claim
18 words
A device according to claim 2 wherein said displacement of spherical centres is in the associated coaxial direction.
Claim 6
Dependent Claim
162 words
An endoprosthetic hip joint device comprising: an acetabular component in the form of a socket member of integral metal construction having an inner bearing surface and outer fixation surface, which surfaces are of concentric substantially hemispherical shape defining a thin thickness theretween, and said outer fixation surface having a shallow relieved formation to receive gap-filling medium in securement with the acetabulum; and a femoral component in the form of a cap member of integral plastics material construction having an outer bearing surface of major-spherical-segment shape in mutual articulatory engagement with said inner bearing surface, and an inner fixation surface of substantially cylindrical shape coaxial with the axis of symmetry of said outer bearing surface, said outer bearing and inner fixation surfaces defining a significantly greater thickness therebetween for said cap member than said socket member, and said inner fixation surface having grooves in the axial and circumferential directions of its cylindrical shape to receive gap-filling medium in direct securement with the femur.
Claim 7
Dependent Claim
162 words
An endoprosthetic hip joint device comprising: an acetabular component in the form of a socket member of integral metal construction having an inner bearing surface and outer fixation surface, which surfaces are of concentric substantially hemispherical shape defining a thin thickness theretween, and said outer fixation surface having a shallow relieved formation to receive gap-filling medium in securement with the acetabulum; and a femoral component in the form of a cap member of integral plastics material construction having an outer bearing surface of major-spherical-segment shape in mutual articulatory engagement with said inner bearing surface, and an inner fixation surface of substantially cylindrical shape coaxial with the axis of symmetry of said outer bearing surface, said outer bearing and inner fixation surfaces defining a significantly greater thickness therebetween for said cap member than said socket member, and said inner fixation surface having grooves in the axial and circumferential directions of its cylindrical shape to receive gap-filling medium in direct securement with the femur.
Claim 8
Dependent Claim
152 words
An endoprosthetic hip joint device comprising: an acetabular component in the form of a socket member of integral plastic construction having an inner bearing surface of minor-spherical-segment shape and an outer fixation surface of hEmispherical shape, said inner bearing and outer fixation surfaces having coaxial axes of symmetry, but eccentrically disposed respective spherical centres to provide greater thickness between such surfaces remote from their peripheral edges, and said outer fixation surface having a shallow relieved formation to receive gap-filling medium in securement with the acetabulum; and a femoral component in the form of a cap member of integral metal construction having an outer bearing surface of major-spherical-segment shape in mutual articulatory engagement with said inner bearing surface, and an inner fixation surface of generally cylindrical shape, said inner fixation surface having grooves in the axial and circumferential directions of its cylindrical shape to receive gap-filling medium in direct securement with the femur.
Claim 9
Dependent Claim
152 words
An endoprosthetic hip joint device comprising: an acetabular component in the form of a socket member of integral plastic construction having an inner bearing surface of minor-spherical-segment shape and an outer fixation surface of hEmispherical shape, said inner bearing and outer fixation surfaces having coaxial axes of symmetry, but eccentrically disposed respective spherical centres to provide greater thickness between such surfaces remote from their peripheral edges, and said outer fixation surface having a shallow relieved formation to receive gap-filling medium in securement with the acetabulum; and a femoral component in the form of a cap member of integral metal construction having an outer bearing surface of major-spherical-segment shape in mutual articulatory engagement with said inner bearing surface, and an inner fixation surface of generally cylindrical shape, said inner fixation surface having grooves in the axial and circumferential directions of its cylindrical shape to receive gap-filling medium in direct securement with the femur.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |