US4312079A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Femur head cap for endoprosthesis
Assignee: Feldmuehle AG
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Filing: 1980-03-31
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Granted: 1982-01-26
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Expires: 2000-03-31
Abstract
Abstract A femur head cap for endoprosthesis possessing a spherical shape and having a recess for partially receiving the femur head, the recess being open toward the neck of the femur. The cap is advantageous in that it can be firmly anchored to avoid rotation and tilting without the use of bone cement and further allows for simple resection to be performed so that supply of blood to the bone is not impaired.
Inventors
- 👤 Erhard Dorre
- 👤 Peter Prussner
- 👤 Ludwig Zichner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:31
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/16; A61B17/1662; A61B17/1664; A61B17/1668; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/32; A61F2/36; A61F2/3601; A61F2/3603; A61F2/30767; A61F2/30771; A61F2002/3082; A61F2002/30878; A61F2002/30879; A61F2/3094; A61F2002/30968; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00185; A61F2310/00203
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
49 words
A femur head cap for an endoprosthesis, having an essentially spherical shape, and a cylindrical recess for partially receiving the femur, said recess being open toward the neck of the femur and the longitudinal axis of the recess extending essentially parallel with the longitudinal center axis of the femur.
Claim 2
Dependent Claim
49 words
A femur head cap for an endoprosthesis, having an essentially spherical shape, and a cylindrical recess for partially receiving the femur, said recess being open toward the neck of the femur and the longitudinal axis of the recess extending essentially parallel with the longitudinal center axis of the femur.
Claim 3
Dependent Claim
53 words
A femur head cap for an endoprosthesis, having an essentially spherical shape, and a recess for partially receiving the femur, said recess being a truncated cone which is open toward the neck of the femur and the longitudinal axis of the recess extending essentially parallel with the longitudinal center axis of the femur.
Claim 4
Dependent Claim
53 words
A femur head cap for an endoprosthesis, having an essentially spherical shape, and a recess for partially receiving the femur, said recess being a truncated cone which is open toward the neck of the femur and the longitudinal axis of the recess extending essentially parallel with the longitudinal center axis of the femur.
Claim 5
Dependent Claim
62 words
A femur head cap for an endoprosthesis, having an essentially spherical shape, and a recess for partially receiving the femur, said recess being open toward the neck of the femur and the longitudinal axis of the recess extending essentially parallel with the longitudinal center axis of the femur wherein the opening of the recess has a smaller inner width than said recess.
Claim 6
Dependent Claim
62 words
A femur head cap for an endoprosthesis, having an essentially spherical shape, and a recess for partially receiving the femur, said recess being open toward the neck of the femur and the longitudinal axis of the recess extending essentially parallel with the longitudinal center axis of the femur wherein the opening of the recess has a smaller inner width than said recess.
Claim 7
Dependent Claim
26 words
The femur head cap of claim 1, 2 or 3, wherein the cap is connected to the femur head stump by means of a force fit.
Claim 8
Dependent Claim
28 words
The femur head cap of claim 1, 2 or 3, wherein the recess is provided with grooves or ribs extending parallel to the center axis of the recess.
Claim 9
Dependent Claim
29 words
The femur head cap of claim 1, 2 or 3, wherein the recess is provided with grooves or ribs which contact only the side portion of the femur head.
Claim 10
Dependent Claim
17 words
The femur head cap of claim 1, 2 or 3, wherein the recess has a rough surface.
Claim 11
Dependent Claim
27 words
The femur head cap of claim 1, 2 or 3, wherein the surface of the recess is provided with pores whose size is greater than 80 micron.
Claim 12
Dependent Claim
21 words
The femur head cap of claim 1, 2 or 3, wherein the femur head cap consists of extremely pure oxide ceramics.
Claim 13
Dependent Claim
122 words
The femur head cap of claim 1, 2 or 3, consisting of a sintered aluminum oxide with a density equal to or greater than 3.92 g/cm 3 , a porosity equal to or less than 2%, a water absorption equal to or less than 0.01%, a purity equal to or greater than 99.7% Al 2 O 3 , a Vickers pyramid hardness (P=2 M) equal to or greater than 22,000 N/mm 2 , an average grain size equal to or smaller than 10 micron, an average bending strength equal to or greater than 300 N/mm 2 , a compressive strength equal to or greater than 4,000 N/mm 2 and a tensile strength of equal to or greater than 160 N/mm 2 .
Claim 14
Dependent Claim
30 words
The femur head cap of claim 1, 2 or 3 wherein the recess is provided with grooves or ribs extending perpendicular to the center of the axis of the recess.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-01-25 | 1985-07-27 | 1986-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-25 | 1989-07-27 | 1990-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-25 | 1993-07-27 | 1994-01-26 | $7700.00 | Window Closed / Lapsed |