US4932969A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Joint endoprosthesis
Assignee: Zimmer GmbH
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Filing: 1987-12-17
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Granted: 1990-06-12
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Expires: 2007-12-17
Abstract
Abstract The joint endoprosthesis is formed of a compressible elastic hollow body which is disposed between two anchoring elements. The hollow body defines a closed cavity which is filled with an incompressible fluid medium. Compressive loadings near the edges of the endoprosthesis cause a displacement of the liquid into relieved regions of the prosthesis so as to avoid tensile forces from occurring in the anchoring of the prosthesis to the bones.
Inventors
- 👤 Otto Frey
- 👤 Rudolf Koch
- 👤 Heinrich M. F. Planck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:28
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/44; A61F2/442; A61F2/441; A61F2/30721; A61F2/30724; A61F2002/30001; A61F2002/30316; A61F2002/30329; A61F2002/30535; A61F2002/30581; A61F2002/30586; A61F2002/30593; A61F2/30767; A61F2/30771; A61F2002/30772; A61F2002/30777; A61F2002/30784; A61F2002/30785; A61F2002/30789; A61F2/30907; A61F2002/30909; A61F2002/30915; A61F2002/30929; A61F2/3094; A61F2002/30971; A61F2220/00; A61F2220/0025; A61F2310/00; A61F2310/00389; A61F2310/00395; A61F2310/00407
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
86 words
A joint endoprosthesis comprising an elastic compressible hollow body having a plurality of partitions defining a plurality of cavities therein and passage openings in said partitions communicating said cavities; an incompressible body-compatible fluid medium filling said, said medium being selected from the group consisting of physiological sodium chloride and silicon oil and being free to move from cavity to cavity to effect liquid equalization between stressed and unstressed cavities during stressing; and anchoring elements on said body for securing said body between and to two bones.
Claim 2
Dependent Claim
86 words
A joint endoprosthesis comprising an elastic compressible hollow body having a plurality of partitions defining a plurality of cavities therein and passage openings in said partitions communicating said cavities; an incompressible body-compatible fluid medium filling said, said medium being selected from the group consisting of physiological sodium chloride and silicon oil and being free to move from cavity to cavity to effect liquid equalization between stressed and unstressed cavities during stressing; and anchoring elements on said body for securing said body between and to two bones.
Claim 3
Dependent Claim
18 words
A joint endoprosthesis as set forth in claim 1 wherein each anchoring element is a multi-layer metal grid.
Claim 4
Dependent Claim
20 words
A joint endoprosthesis as set forth in claim 1 which further comprises a circumferentially disposed reinforcing means in said body.
Claim 5
Dependent Claim
23 words
A joint endoprosthesis as set forth in claim 1 wherein said body is a toroidal ring and said cavities include an annular cavity.
Claim 6
Dependent Claim
22 words
A joint endoprosthesis as set forth in claim 4 which further comprises a pair of contoured shells matingly receiving said body therebetween.
Claim 7
Dependent Claim
121 words
An intervertebral endoprosthesis for implantation between two vertebral bodies comprising an elastic compressible hollow body having a plurality of partitions defining a plurality of cavities therein and passage openings in said partitions communicating said cavities therein; an incompressible body-compatible fluid medium filling said cavities to render said body at least approximately incompressible in an axial direction thereof wherein under a decentralized load said fluid medium is free to move from cavity to cavity to effect liquid equalization between stressed and unstressed cavities during stressing whereby said fluid medium shifts to a load remote region of said body for expansion thereof to reduce tensile stresses thereat; and anchoring elements on said body for securing said body between and to two vertebral bodies.
Claim 8
Dependent Claim
121 words
An intervertebral endoprosthesis for implantation between two vertebral bodies comprising an elastic compressible hollow body having a plurality of partitions defining a plurality of cavities therein and passage openings in said partitions communicating said cavities therein; an incompressible body-compatible fluid medium filling said cavities to render said body at least approximately incompressible in an axial direction thereof wherein under a decentralized load said fluid medium is free to move from cavity to cavity to effect liquid equalization between stressed and unstressed cavities during stressing whereby said fluid medium shifts to a load remote region of said body for expansion thereof to reduce tensile stresses thereat; and anchoring elements on said body for securing said body between and to two vertebral bodies.
Claim 9
Dependent Claim
19 words
An endoprosthesis as set forth in claim 6 which further comprises a circumferentially disposed reinforcing means in said body.
Claim 10
Dependent Claim
41 words
An endoprosthesis as set forth in claim 6 wherein said body is a toroidal ring and said cavities include an annular cavity and a flow cavity bridging said annular cavity and communicating therewith for diametric flow of said fluid medium therethrough.
Claim 11
Dependent Claim
16 words
An endoprosthesis as set forth in claim 6 wherein said fluid medium is a salt solution.
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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) | 1993-06-11 | 1993-12-11 | 1994-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-11 | 1997-12-11 | 1998-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-11 | 2001-12-11 | 2002-06-12 | $7700.00 | Window Closed / Lapsed |