US5480445A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interlocking tibial prosthesis
Assignee: Zimmer Inc
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Filing: 1994-06-09
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Granted: 1996-01-02
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Expires: 2014-06-09
Abstract
Abstract A tibial knee prosthesis having a plastic or polyethylene prosthesis body comprising an articulating surface and medullary stem. An intermediate metal plate locks on to the medullary stem and fits between the articulating surface and a resected proximal surface of the tibia. A distal surface of the plate may be provided with a porous coating adjacent the proximal resected surface of the tibia, to encourage bone ingrowth and fixation.
Inventors
- 👤 Brian D. Burkinshaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:10
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/38; A61F2/389; A61F2/30767; A61F2002/30001; A61F2002/30108; A61F2002/3011; A61F2002/30159; A61F2002/30179; A61F2002/30316; A61F2002/30329; A61F2002/30331; A61F2002/30362; A61F2002/30364; A61F2002/30367; A61F2002/30476; A61F2002/305; A61F2002/30535; A61F2002/30594; A61F2/30771; A61F2002/30795; A61F2002/308; A61F2002/30878; A61F2002/30884; A61F2220/00; A61F2220/0025; A61F2220/0033; A61F2230/00; A61F2230/0002; A61F2230/0028; A61F2230/0058; A61F2310/00; A61F2310/00005; A61F2310/00011; A61F2310/00179
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
164 words
A tibial component of a knee prosthesis comprising a body and a support plate, said body having a proximal plate adapted to lie near a proximal resected surface on a patient's tibia, said plate having a distal surface and an articulating surface forming a medial condyle compartment and a lateral condyle compartment and a central stem integral with said plate adapted to be inserted into a prepared cavity in the medullar canal of the patient, said stem having at least one peripheral slot adjacent and parallel to said distal surface for fastening said support plate to said body, and said support plate having a proximal surface adapted to fit against said distal surface of said proximal plate, an affixation surface adapted to fit against said proximal resected surface on the patient's tibia, a central opening through which the stem fits, and at least one peripheral tab extending into said central opening for engaging said slot whereby said support plate is attached to said body.
Claim 2
Dependent Claim
164 words
A tibial component of a knee prosthesis comprising a body and a support plate, said body having a proximal plate adapted to lie near a proximal resected surface on a patient's tibia, said plate having a distal surface and an articulating surface forming a medial condyle compartment and a lateral condyle compartment and a central stem integral with said plate adapted to be inserted into a prepared cavity in the medullar canal of the patient, said stem having at least one peripheral slot adjacent and parallel to said distal surface for fastening said support plate to said body, and said support plate having a proximal surface adapted to fit against said distal surface of said proximal plate, an affixation surface adapted to fit against said proximal resected surface on the patient's tibia, a central opening through which the stem fits, and at least one peripheral tab extending into said central opening for engaging said slot whereby said support plate is attached to said body.
Claim 3
Dependent Claim
20 words
The tibial component according to claim 1 wherein said body is formed entirely from a single piece of biocompatible polymer.
Claim 4
Dependent Claim
17 words
The tibial component according to claim 2 wherein said support plate is comprised substantially completely of metal.
Claim 5
Dependent Claim
47 words
The tibial component according to claim 1 wherein said at least one slot comprises at least two slots located radially opposite each other across said stem and wherein said at least one tab comprise at least two tabs located radially opposite each other across said central opening.
Claim 6
Dependent Claim
73 words
The tibial component according to claim 4 wherein the stem has a cruciate cross-section with four orthogonal extensions, each extension having a slot at a base thereof adjacent said distal surface of said proximal plate, and said central opening has a corresponding cruciate perimeter forming four orthogonal openings, each opening subtending an arc equal to at least twice the arc subtended by an associated extension, and each opening having a tab extending thereinto.
Claim 7
Dependent Claim
18 words
The tibial component according to claim 5 wherein said body is formed substantially entirely from a biocompatible polymer.
Claim 8
Dependent Claim
16 words
The tibial component according to claim 6 wherein said polymer is ultra high molecular weight polyethylene.
Claim 9
Dependent Claim
17 words
The tibial component according to claim 6 wherein said support plate is comprised substantially completely of metal.
Claim 10
Dependent Claim
19 words
The tibial component according to claim 8 wherein the support plate has a porous coating on said affixation surface.
Claim 11
Dependent Claim
25 words
The tibial component according to claim 1 further comprising means for locking said tab into said slot by inhibiting reverse rotation of said support plate.
Claim 12
Dependent Claim
47 words
The tibial component according to claim 10 wherein said at least one slot comprises at least two slots located radially opposite each other across said stem and wherein said at least one tab comprise at least two tabs located radially opposite each other across said central opening.
Claim 13
Dependent Claim
73 words
The tibial component according to claim 11 wherein the stem has a cruciate cross-section with four orthogonal extensions, each extension having a slot at a base thereof adjacent said distal surface of said proximal plate, and said central opening has a corresponding cruciate perimeter forming four orthogonal openings, each opening subtending an arc equal to at least twice the arc subtended by an associated extension, and each opening having a tab extending thereinto.
Claim 14
Dependent Claim
18 words
The tibial component according to claim 12 wherein said body is formed substantially entirely from a biocompatible polymer.
Claim 15
Dependent Claim
16 words
The tibial component according to claim 13 wherein said polymer is ultra high molecular weight polyethylene.
Claim 16
Dependent Claim
17 words
The tibial component according to claim 13 wherein said support plate is comprised substantially completely of metal.
Claim 17
Dependent Claim
19 words
The tibial component according to claim 15 wherein the support plate has a porous coating on said affixation surface.
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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 |