US5480452A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Femoral prosthesis with wedge having opposed tapers
Assignee: Zimmer Inc
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Filing: 1993-10-21
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Granted: 1996-01-02
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Expires: 2013-10-21
Abstract
Abstract A prosthesis having a proximal portion of a stem formed as a wedge having opposed tapers such that prostheses can be thrust into a medullary canal and achieve fixation without unduly stressing the cortical bone remaining in the femur. Ribs secure the prosthesis against medial-lateral motion. Simultaneously, a degree of flexibility is provided in an anterior-posterior direction. A slotted distal portion of the stem is flared to enhance fixation distally.
Inventors
- 👤 Aaron A. Hofmann
- 👤 James E. Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:17
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/32; A61F2/36; A61F2/3662; A61F2/30767; A61F2/30721; A61F2/30734; A61F2/367; A61F2/3676; A61F2002/30001; A61F2002/30316; A61F2002/30317; A61F2002/30322; A61F2002/30329; A61F2002/30476; A61F2002/30515; A61F2002/30535; A61F2002/30579; A61F2002/30594; A61F2/30771; A61F2002/30878; A61F2002/30879; A61F2/3609; A61F2002/3625; A61F2002/3631; A61F2220/00; A61F2220/0025; A61F2250/00; A61F2250/0014; A61F2250/0026; A61F2310/00; A61F2310/00389; A61F2310/00395; A61F2310/00407
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
207 words
An implantable prosthesis comprising an articulating head; and a stem connected to said articulating head for attaching said prosthesis to a bone of a patient, said stem having at least one anterior-posterior side adapted to lie substantially in an anterior-posterior plane when said prosthesis is implanted in a patient and at least one medial-lateral side adapted to lie substantially in a medial-lateral plane when said prosthesis is implanted in a patient, means on said at least one anterior-posterior side for resisting motion in anterior-posterior directions, said means on said anterior-posterior side comprising anterior-posterior porous fixation means in an anterior-posterior proximal portion; and anterior-posterior immediate fixation means in an anterior-posterior distal portion, said immediate fixation means providing decreasing resistance to anterior-posterior motion from a proximal end of said anterior-posterior distal portion to a distal end of said first distal portion, and means on said at least one medial-lateral side for resisting motion in medial-lateral directions, said means on said medial-lateral side comprising medial-lateral porous fixation means in a medial-lateral proximal portion; medial-lateral immediate fixation means in a medial-lateral distal portion, said immediate fixation means providing increasing resistance to medial-lateral motion from a proximal end of said medial-lateral distal portion to a distal end of said medial-lateral distal portion.
Claim 2
Dependent Claim
207 words
An implantable prosthesis comprising an articulating head; and a stem connected to said articulating head for attaching said prosthesis to a bone of a patient, said stem having at least one anterior-posterior side adapted to lie substantially in an anterior-posterior plane when said prosthesis is implanted in a patient and at least one medial-lateral side adapted to lie substantially in a medial-lateral plane when said prosthesis is implanted in a patient, means on said at least one anterior-posterior side for resisting motion in anterior-posterior directions, said means on said anterior-posterior side comprising anterior-posterior porous fixation means in an anterior-posterior proximal portion; and anterior-posterior immediate fixation means in an anterior-posterior distal portion, said immediate fixation means providing decreasing resistance to anterior-posterior motion from a proximal end of said anterior-posterior distal portion to a distal end of said first distal portion, and means on said at least one medial-lateral side for resisting motion in medial-lateral directions, said means on said medial-lateral side comprising medial-lateral porous fixation means in a medial-lateral proximal portion; medial-lateral immediate fixation means in a medial-lateral distal portion, said immediate fixation means providing increasing resistance to medial-lateral motion from a proximal end of said medial-lateral distal portion to a distal end of said medial-lateral distal portion.
Claim 3
Dependent Claim
54 words
The implantable prosthesis according to claim 1 wherein said anterior-posterior immediate fixation means comprise a series of adjacent zones, each zone providing relatively decreasing resistance to anterior-posterior motion from a first zone adjacent said proximal end of said anterior-posterior distal portion to a last zone adjacent said distal end of said anterior-posterior distal portion.
Claim 4
Dependent Claim
53 words
The implantable prosthesis according to claim 1 further comprising a wedge structure with opposed tapers integrally affixed on at least one side of said stem, said wedge structure having a first tapered surface commencing adjacent said side distally and rising away from said side proximally and which is broad distally and narrow proximally.
Claim 5
Dependent Claim
15 words
The implantable prosthesis according to claim 3 wherein said first tapered surface is a plane.
Claim 6
Dependent Claim
16 words
The implantable prosthesis according to claim 4 wherein said second and third tapered surfaces are planes.
Claim 7
Dependent Claim
107 words
The implantable prosthesis according to claim 3 wherein the wedge structure further comprises a second tapered surface between said first tapered surface and said side of said stem, said second tapered surface forming a first junction between said second surface and said side and a third tapered surface between said first tapered surface and said side of said stem, said third tapered surface forming a second junction between said third tapered surface and said side, said first and second junctions being spaced apart from each other a distal distance at least the distal breadth of said first surface and a proximal distance greater than said distal distance.
Claim 8
Dependent Claim
104 words
The implantable prosthesis according to claim 2 wherein said first zone has a ridge extending longitudinally along said anterior-posterior side of said prosthesis in a said first zone, substantially adjacent said anterior-posterior proximal portion, said ridge extending from a proximal end to a distal end of said first zone; and wherein said distal zone has a slot extending in a medial-lateral plane in said distal zone, and wherein said anterior-posterior portion further comprises an intermediate zone between said first zone and said distal zone, said intermediate zone having a second ridge with chamfered anterior and posterior edges extending longitudinally in said second intermediate zone.
Claim 9
Dependent Claim
12 words
The implantable prosthesis according to claim 7 wherein the slot is flared.
Claim 10
Dependent Claim
21 words
The implantable prosthesis according to claim 8 wherein said at least one anterior-posterior side is a lateral side of said stem.
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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) | 1999-01-01 | 1999-07-03 | 2000-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-01 | 2003-07-03 | 2004-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-01 | 2007-07-03 | 2008-01-02 | $7700.00 | Window Closed / Lapsed |