Patent US4851008A successfully refreshed from Google Patents.
US4851008A
Expired / Lapsed
US
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Bone implant prosthesis with substantially stress-free outer surface
Assignee: Wright Medical Technology Inc
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Filing: 1988-02-01
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Granted: 1989-07-25
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Expires: 2008-02-01
Abstract
Abstract A bone implant prosthesis having an outer stress-free surface and a subsurface carried generally beneath and parallel to the outer surface for bearing tensile stresses. The prosthesis of the invention includes a plurality of slots undercutting the outer surface of the prosthesis thus forming a stress bearing subsurface to free the outer surface from being subjected to substantial stresses. The stress-free outer surface is readily adaptable to receive a porous coating to enhance bone ingrowth without decreasing the stress resistance characteristics of the prosthesis.
Inventors
- 👤 Wesley Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:07
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/30767; A61F2/30771; A61F2/32; A61F2/36; A61F2/3662; A61F2/3672; A61F2002/30001; A61F2002/30108; A61F2002/3011; A61F2002/30159; A61F2002/30172; A61F2002/30199; A61F2002/30289; A61F2002/30316; A61F2002/30535; A61F2002/30594; A61F2002/30795; A61F2002/30807; A61F2002/30808; A61F2002/3082; A61F2/3609; A61F2002/3625; A61F2002/3631; A61F2230/00; A61F2230/0002; A61F2230/0028; A61F2230/0052; A61F2230/0063; A61F2230/0091
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
63 words
A bone implant prosthesis comprising a body portion having an outer surface containing stress concentration sites, and a series of elongated generally parallel slots formed through the outer surface, the slots having widened floor portions defining a stress-bearing discontinuous smooth subsurface spaced beneath the outer surface, the slots rendering the outer surface of the prosthesis essentially free of tensile stresses when in use.
Claim 2
Dependent Claim
63 words
A bone implant prosthesis comprising a body portion having an outer surface containing stress concentration sites, and a series of elongated generally parallel slots formed through the outer surface, the slots having widened floor portions defining a stress-bearing discontinuous smooth subsurface spaced beneath the outer surface, the slots rendering the outer surface of the prosthesis essentially free of tensile stresses when in use.
Claim 3
Dependent Claim
20 words
The bone implant prosthesis of claim 1 wherein the outer stress-free surface carries a porous coating to enhance bone ingrowth.
Claim 4
Dependent Claim
19 words
The bone implant prosthesis of claim 1 wherein the sub-surface is substantially smooth and free of stress concentration sites.
Claim 5
Dependent Claim
28 words
The prosthesis of claim 1 in which the slots are sized to prevent adjacent outer surface portions thereof from contacting one another when the prosthesis is in use.
Claim 6
Dependent Claim
79 words
A bone implant prosthesis comprising a body portion adapted to encounter bone and having an outer surface containing stress concentration sites, the body portion having formed therein a series of elongated generally "T"-shaped slots, the cross bar portions of adjacent T-shaped slots cooperating to define a stress-bearing, discontinuous smooth subsurface generally parallel to and spaced beneath the outer surface of the prosthesis, said slots rendering the outer surface of the prosthesis essentially free of tensile stresses when in use.
Claim 7
Dependent Claim
79 words
A bone implant prosthesis comprising a body portion adapted to encounter bone and having an outer surface containing stress concentration sites, the body portion having formed therein a series of elongated generally "T"-shaped slots, the cross bar portions of adjacent T-shaped slots cooperating to define a stress-bearing, discontinuous smooth subsurface generally parallel to and spaced beneath the outer surface of the prosthesis, said slots rendering the outer surface of the prosthesis essentially free of tensile stresses when in use.
Claim 8
Dependent Claim
78 words
A bone implant prosthesis comprising a body portion formed as an integral unit and having a porous outer surface to promote bone growth therein, the body portion being provided with a series of elongated generally parallel spaced slots extending through the outer surface, the slots having widened portions spaced beneath the outer surface together defining a smooth discontinuous stress-bearing subsurface, the slots rendering the porous outer surface essentially free of tensile stresses developed during use of the prosthesis.
Claim 9
Dependent Claim
78 words
A bone implant prosthesis comprising a body portion formed as an integral unit and having a porous outer surface to promote bone growth therein, the body portion being provided with a series of elongated generally parallel spaced slots extending through the outer surface, the slots having widened portions spaced beneath the outer surface together defining a smooth discontinuous stress-bearing subsurface, the slots rendering the porous outer surface essentially free of tensile stresses developed during use of the prosthesis.
Claim 10
Dependent Claim
26 words
The prosthesis of claim 6 in which the slots are generally "T" shaped with the cross bar of the T forming the floor of each slot.
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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) | 1992-07-24 | 1993-01-23 | 1993-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-24 | 1997-01-23 | 1997-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-24 | 2001-01-23 | 2001-07-25 | $7700.00 | Window Closed / Lapsed |