Patent US4978359A successfully refreshed from Google Patents.
US4978359A
Expired / Lapsed
US
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Prosthesis shaft
Assignee: Thera Patent GmbH and Co KG Gesellschaft fuer Industrielle Schutzrechte
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Filing: 1989-04-27
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Granted: 1990-12-18
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Expires: 2009-04-27
Abstract
Abstract For anchoring a prosthesis within a bone by means of a bone cement (32), prothesis shaft has a surface which is formed by the surfaces of a plurality of spheres (23 . . . 25) partially penetrating each other and having radii which decrease from the proximal towards the distal shaft end. The transitional zones between adjacent spheres (23 . . . 25) are concavely rounded. This shape is especially suited for use with a glass ionomer-type bone cement, because the shaft exerts substantially only compressive forces on the cement, whereas tensile and notch stresses, with respect to which this kind of cement exhibits little resistance, are largely avoided.
Inventors
- 👤 Klaus Wilhelm
- 👤 Johann Bauer
- 👤 Werner Schmitt
- 👤 Wolf-Dietrich Herold
- 👤 Peter Koran
- 👤 Erich Wanek
- 👤 Oswald Gasser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:35
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/32; A61F2/36; A61F2/3662; A61F2/3609; A61F2002/3625; A61F2002/3631
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
102 words
An implantable prosthesis comprising; an elongated shaft having a center line along its length, said shaft having opposite proximal and distal ends and configured for insertion into a cavity formed in a bone, the shaft having an outer surface formed by convex surfaces of a plurality of aligned spheres, said spheres having their centers disposed substantially along the center line of the shaft, the convex surfaces of adjacent spheres partially intersecting each other to form rounded concave transitional zones between the adjacent convex surfaces, wherein the radii of the spheres decrease from the proximal end to the distal end of the shaft.
Claim 2
Dependent Claim
102 words
An implantable prosthesis comprising; an elongated shaft having a center line along its length, said shaft having opposite proximal and distal ends and configured for insertion into a cavity formed in a bone, the shaft having an outer surface formed by convex surfaces of a plurality of aligned spheres, said spheres having their centers disposed substantially along the center line of the shaft, the convex surfaces of adjacent spheres partially intersecting each other to form rounded concave transitional zones between the adjacent convex surfaces, wherein the radii of the spheres decrease from the proximal end to the distal end of the shaft.
Claim 3
Dependent Claim
22 words
The prosthesis of claim 1, wherein the centers of the spheres lie along the shaft and outside of the respective transitional zones.
Claim 4
Dependent Claim
21 words
The prosthesis of claim 1, wherein at least one sphere is flattened to prevent rotation of the shaft within the cavity.
Claim 5
Dependent Claim
95 words
An implantable prosthesis comprising; an elongated shaft having a center line along its length, said shaft having opposite proximal and distal ends and configured for insertion into a cavity formed in a bone, the shaft having an outer surface formed by convex surfaces of adjacent spheres of a plurality of aligned spheres, said spheres having their centers disposed substantially along the center line of the shaft, the convex surfaces partially intersecting each other to form rounded concave transitional zones between the adjacent convex surfaces, wherein the shaft includes at least one portion of non-circular cross-section.
Claim 6
Dependent Claim
95 words
An implantable prosthesis comprising; an elongated shaft having a center line along its length, said shaft having opposite proximal and distal ends and configured for insertion into a cavity formed in a bone, the shaft having an outer surface formed by convex surfaces of adjacent spheres of a plurality of aligned spheres, said spheres having their centers disposed substantially along the center line of the shaft, the convex surfaces partially intersecting each other to form rounded concave transitional zones between the adjacent convex surfaces, wherein the shaft includes at least one portion of non-circular cross-section.
Claim 7
Dependent Claim
22 words
The prosthesis of claim 4, wherein the centers of the spheres lie along the shaft and outside of the respective transitional zones.
Claim 8
Dependent Claim
23 words
The prosthesis of claim 4, wherein the radii of the spheres decrease from the proximal end to the distal end of the shaft.
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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) | 1993-12-17 | 1994-06-18 | 1994-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-17 | 1998-06-18 | 1998-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-17 | 2002-06-18 | 2002-12-18 | $7700.00 | Window Closed / Lapsed |