US5358529A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plastic knee femoral implants
Assignee: Smith and Nephew Inc
•
Filing: 1993-03-05
•
Granted: 1994-10-25
•
Expires: 2013-03-05
Abstract
Abstract A knee prosthesis includes plastic femoral and metallic (or ceramic) tibial components. The plastic femoral knee component articulates against a polished metal (e.g. cobalt alloy, titanium alloy, or stainless steel), or preferably ceramic (e.g. alumina, zirconia, nitride, or boride) patella and tibial components in a total knee implant. The polymer femoral material can be of a polymer such as ultra high molecular weight polyethylene, or a polymer blend or a fiber or particle reinforced polymer, or layered polymers.
Inventors
- 👤 James A. Davidson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:56
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/38; A61F2/30767; A61F2/3094; A61F2/30965; A61F2/3877
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
117 words
A total knee prosthesis comprising: a) a bridged, near-anatomically shaped, bicondylar polymer femoral component having a pair of spaced, generally convex polymeric bearing surface of thickness greater than about six millimeters (6 mm) at articulating surface regions; b) a tibial component with a metallic bearing surface portion that includes concavities that receive the polymeric bearing surface of the femoral component during articulation of the femoral component upon the tibial component; c) a patella component with a metallic bearing surface portion that receives the polymer bearing surface of the femoral component during articulation of the femoral component upon the patella component; and d) a femoral attachment that enables the femoral component to be attached to the patient's femur.
Claim 2
Dependent Claim
117 words
A total knee prosthesis comprising: a) a bridged, near-anatomically shaped, bicondylar polymer femoral component having a pair of spaced, generally convex polymeric bearing surface of thickness greater than about six millimeters (6 mm) at articulating surface regions; b) a tibial component with a metallic bearing surface portion that includes concavities that receive the polymeric bearing surface of the femoral component during articulation of the femoral component upon the tibial component; c) a patella component with a metallic bearing surface portion that receives the polymer bearing surface of the femoral component during articulation of the femoral component upon the patella component; and d) a femoral attachment that enables the femoral component to be attached to the patient's femur.
Claim 3
Dependent Claim
16 words
The knee prosthesis of claim 1 wherein the polymer is an ultra high molecular weight polymer.
Claim 4
Dependent Claim
16 words
The knee prosthesis of claim 1 wherein the polymer is an ultra high molecular weight polyolefin.
Claim 5
Dependent Claim
16 words
The knee prosthesis of claim 1 wherein the polymer is an ultra high molecular weight polyethylene.
Claim 6
Dependent Claim
19 words
The knee prosthesis of claim 1 wherein the tibial and patella components are of a ceramic coated metal material.
Claim 7
Dependent Claim
17 words
The knee prosthesis of claim 1 wherein the tibial and patella components are of a ceramic material.
Claim 8
Dependent Claim
20 words
The knee prosthesis of claim 1 wherein the femoral component has a porous polymer coating portion for promoting bone ingrowth.
Claim 9
Dependent Claim
24 words
The knee prostheses of claim 1 wherein the femoral component contains a porous coated portion for improving bone cement attachment or promoting bone ingrowth.
Claim 10
Dependent Claim
19 words
The knee prosthesis of claim 8 wherein the femoral component has a metal bead coating for promoting bone ingrowth.
Claim 11
Dependent Claim
18 words
The knee prosthesis of claim 8 wherein the femoral component has a mesh coating for promoting bone ingrowth.
Claim 12
Dependent Claim
23 words
The knee prostheses of claim 1 wherein the tibial component contains a textured porous coating for promoting bone cement attachment or bone ingrowth.
Claim 13
Dependent Claim
19 words
The knee prosthesis of claim 11 wherein the tibial component has a metal bead coating for promoting bone ingrowth.
Claim 14
Dependent Claim
18 words
The knee prosthesis of claim 11 wherein the tibial component has a mesh coating for promoting bone ingrowth.
Claim 15
Dependent Claim
26 words
The knee prosthesis of claim 1 comprising a patella component that has a metallic bearing surface that articulates against the polymeric surface of the femoral component.
Claim 16
Dependent Claim
19 words
The knee prosthesis of claim 14 wherein the tibial component and patella component are each of a cobalt alloy.
Claim 17
Dependent Claim
20 words
The knee prosthesis of claim 1 wherein the femoral component has a metallic backing portion opposite the polymeric bearing surface.
Claim 18
Dependent Claim
12 words
The knee prosthesis of claim 16 wherein the backing is partial backing.
Claim 19
Dependent Claim
31 words
The knee prosthesis of claim 16 wherein the backing is a full backing that substantially covers the back side of the femoral component opposite the bearing surface of the femoral component.
Claim 20
Dependent Claim
14 words
The knee prosthesis of claim 1 wherein the polymer is a wear resistant polymer.
Claim 21
Dependent Claim
14 words
The knee prosthesis of claim 1 wherein the polymer is a creep resistant polymer.
Claim 22
Dependent Claim
133 words
A total knee prosthesis comprising: a) a bridged, near-anatomically shaped, bicondylar polymer femoral component having a pair of spaced, generally convex polymeric bearing surfaces of thickness greater than about six millimeters (6 mm) at articulating surface regions; b) a tibial component with a ceramic bearing surface portion that includes concavities that receive the polymeric bearing surface of the femoral component during articulation of the femoral component upon the tibial component; c) a patella component with a ceramic bearing surface portion that receives the polymeric bearing surface of the femoral component during articulation of the femoral component upon the patella component; d) femoral attachment means for enabling the femoral component to be attached to the patient's femur; and e) tibial attachment means for enabling the tibial component to be attached to the patient's tibia.
Claim 23
Dependent Claim
133 words
A total knee prosthesis comprising: a) a bridged, near-anatomically shaped, bicondylar polymer femoral component having a pair of spaced, generally convex polymeric bearing surfaces of thickness greater than about six millimeters (6 mm) at articulating surface regions; b) a tibial component with a ceramic bearing surface portion that includes concavities that receive the polymeric bearing surface of the femoral component during articulation of the femoral component upon the tibial component; c) a patella component with a ceramic bearing surface portion that receives the polymeric bearing surface of the femoral component during articulation of the femoral component upon the patella component; d) femoral attachment means for enabling the femoral component to be attached to the patient's femur; and e) tibial attachment means for enabling the tibial component to be attached to the patient's tibia.
Claim 24
Dependent Claim
20 words
The knee prosthesis of claim 1 wherein the femoral component has a rigid backing portion opposite the polymeric bearing surface.
Claim 25
Dependent Claim
16 words
The knee prosthesis of claim 1 wherein the polymer has a carbon fiber reinforced polymer composite.
Claim 26
Dependent Claim
20 words
The knee prosthesis of claim 21 wherein the polymer of the femoral component is an ultra high molecular weight polymer.
Claim 27
Dependent Claim
20 words
The knee prosthesis of claim 21 wherein the polymer of the femoral component is an ultra high molecular weight polyolefin.
Claim 28
Dependent Claim
20 words
The knee prosthesis of claim 21 wherein the polymer of the femoral component is an ultra high molecular weight polyethylene.
Claim 29
Dependent Claim
19 words
The knee prosthesis of claim 21 wherein the tibial and patella components are of a ceramic coated metal material.
Claim 30
Dependent Claim
18 words
The knee prosthesis of claim 21 wherein the tibial and patella components are entirely of a ceramic material.
Claim 31
Dependent Claim
20 words
The knee prosthesis of claim 21 wherein the femoral component has a porous polymer coating portion for promoting bone ingrowth.
Claim 32
Dependent Claim
24 words
The knee prostheses of claim 21 wherein the femoral component contains a porous coated portion for improving bone cement attachment or promoting bone ingrowth.
Claim 33
Dependent Claim
19 words
The knee prosthesis of claim 30 wherein the femoral component has a metal bead coating for promoting bone ingrowth.
Claim 34
Dependent Claim
18 words
The knee prosthesis of claim 30 wherein the femoral component has a mesh coating for promoting bone ingrowth.
Claim 35
Dependent Claim
23 words
The knee prosthesis of claim 21 wherein the tibial component contains a textured porous coating for promoting bone cement attachment or bone ingrowth.
Claim 36
Dependent Claim
19 words
The knee prosthesis of claim 33 wherein the tibial component has a metal bead coating for promoting bone ingrowth.
Claim 37
Dependent Claim
18 words
The knee prosthesis of claim 33 wherein the tibial component has a mesh coating for promoting bone ingrowth.
Claim 38
Dependent Claim
26 words
The knee prosthesis of claim 21 comprising a patella component that has a metallic bearing surface that articulates against the polymeric surface of the femoral component.
Claim 39
Dependent Claim
19 words
The knee prosthesis of claim 36 wherein the tibial component and patella component are each of a cobalt alloy.
Claim 40
Dependent Claim
20 words
The knee prosthesis of claim 21 wherein the femoral component has a metallic backing portion opposite the polymeric bearing surface.
Claim 41
Dependent Claim
12 words
The knee prosthesis of claim 38 wherein the backing is partial backing.
Claim 42
Dependent Claim
31 words
The knee prosthesis of claim 38 wherein the backing is a full backing that substantially covers the back side of the femoral component opposite the bearing surface of the femoral component.
Claim 43
Dependent Claim
14 words
The knee prosthesis of claim 21 wherein the polymer is a wear resistant polymer.
Claim 44
Dependent Claim
14 words
The knee prosthesis of claim 21 wherein the polymer is a creep resistant polymer.
Claim 45
Dependent Claim
20 words
The knee prosthesis of claim 21 wherein the femoral component has a rigid backing portion opposite the polymeric bearing surface.
Claim 46
Dependent Claim
16 words
The knee prosthesis of claim 21 wherein the polymer has a carbon fiber reinforced polymer composite.
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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) | 1997-10-24 | 1998-04-25 | 1998-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-24 | 2002-04-25 | 2002-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-24 | 2006-04-25 | 2006-10-25 | $7700.00 | Window Closed / Lapsed |