US5314482A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Femoral component, tool and method
Assignee: BTG International Ltd
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Filing: 1991-11-08
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Granted: 1994-05-24
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Expires: 2011-11-08
Abstract
Abstract A prosthetic femoral component (40) for the knee joint has a body (41,42) defined between elongate articulation and securement surfaces (43; 44,45), the articulation surface (43) being convexly spherically shaped and the securement surface having major and minor areas at opposite end portions, the major area (44) being essentially concavely spherically concentric with the articulation surface to form a shell body part (41), and the minor area (45) being essentially planar extending chordally of the articulation surface. A bone-penetrating pin (46) preferably extends radially from the major securement surface area in a direction parallel to the longitudinal direction of the neighbouring minor area. A related surgical tool (50) for shaping the femoral condyle has a rotary cutter (52) to provide a cut bone surface complementing the component major area, and a guide spigot (53) projecting adjustably coaxially within the cutter.
Inventors
- 👤 John W. Goodfellow
- 👤 John J. O'Connor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:24
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/16; A61B17/1662; A61B17/1675; A61B17/1637; A61B17/17; A61B17/1739; A61B17/1764; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/38; A61F2/3859; A61F2002/3895
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
157 words
A method of preparing a femoral condyle for securement thereto of a prosthetic component having a bone engaging concave surface configured for fixation to the bone of said condyle, said surface having at least a major area shaped as a concave segment curved in each of three-dimensions thereby substantially defining a surface of revolution about an axis therethrough, which method comprises exposing said condyle, locating the condyle in a position of flexion with its posterior portion immediately adjacent the tibia, forming in the inferior portion of the condyle a bore which is axially parallel to the longitudinal axis of the femur and located radially at a first predetermined spacing from the tibia in said position of flexion, forming a condyle to a shape substantially complementary to said surface of revolution, and locating said complementary shape coaxially with said bore and at a second predetermined spacing from the tibia in a position of full extension for said condyle.
Claim 2
Independent Claim
157 words
A method of preparing a femoral condyle for securement thereto of a prosthetic component having a bone engaging concave surface configured for fixation to the bone of said condyle, said surface having at least a major area shaped as a concave segment curved in each of three-dimensions thereby substantially defining a surface of revolution about an axis therethrough, which method comprises exposing said condyle, locating the condyle in a position of flexion with its posterior portion immediately adjacent the tibia, forming in the inferior portion of the condyle a bore which is axially parallel to the longitudinal axis of the femur and located radially at a first predetermined spacing from the tibia in said position of flexion, forming a condyle to a shape substantially complementary to said surface of revolution, and locating said complementary shape coaxially with said bore and at a second predetermined spacing from the tibia in a position of full extension for said condyle.
Claim 3
Dependent Claim
18 words
A method according to claim 1 wherein said first predetermined spacing and second predetermined spacing are substantially equal.
Claim 4
Dependent Claim
90 words
A prosthetic femoral component for the knee joint, comprising: a body having a bearing surface and a bone engaging surface in back-to-back disposition; said bearing surface being of three-dimensionally curved convex shape to serve a condylar articulation function; said bone engaging surface being concave configured for fixation to the bone of a femur; and said bone engaging surface having a major concave segment curved in each of three-dimensions thereby substantially defining a surface of revolution about an axis therethrough, and a substantially planar minor segment extending parallel to said axis.
Claim 5
Dependent Claim
90 words
A prosthetic femoral component for the knee joint, comprising: a body having a bearing surface and a bone engaging surface in back-to-back disposition; said bearing surface being of three-dimensionally curved convex shape to serve a condylar articulation function; said bone engaging surface being concave configured for fixation to the bone of a femur; and said bone engaging surface having a major concave segment curved in each of three-dimensions thereby substantially defining a surface of revolution about an axis therethrough, and a substantially planar minor segment extending parallel to said axis.
Claim 6
Dependent Claim
38 words
A component according to claim 3, wherein said body is elongated and has first and second opposite, mutually adjoining end portions and said major and minor segments each extending over a respective end portion of said elongated body.
Claim 7
Dependent Claim
21 words
A component according to claim 1 wherein at least one of said bearing surface and said major segment is spherically shaped.
Claim 8
Dependent Claim
23 words
A component according to claim 5 wherein both of said bearing surface and said major area are spherically shaped in mutually concentric manner.
Claim 9
Dependent Claim
21 words
A component according to claim 3 wherein said body has an elongate member projecting from said major segment along said axis.
Claim 10
Dependent Claim
17 words
A component according to claim 7 wherein said member is generally cylindrical, having a substantially circular cross-section.
Claim 11
Dependent Claim
22 words
A component according to claim 7 wherein said member projects from said major segment a distance within the perimeter of said body.
Claim 12
Dependent Claim
148 words
A prosthetic femoral component for the knee joint, comprising: an elongated body having a bearing surface and a bone engaging surface in back-to-back disposition and having first and second opposite, mutually adjoining end portions; said bearing surface being of convex spherical shape to serve a condylar articulation function; said bone engaging surface being concave configured for fixation to the bone of a femoral condyle, and having major and minor segments extending over a respective end portion of said elongated body; said major segment being curved in each of three dimensions so as to be of concave substantially spherical shape concentric with said convex spherical shape; said minor segment being of substantially plane shape extending as a chord of said convex spherical shape; and said major segment having an elongated member projecting therefrom along a common radius of said convex and concave spherical shapes parallel with said minor segment.
Claim 13
Dependent Claim
148 words
A prosthetic femoral component for the knee joint, comprising: an elongated body having a bearing surface and a bone engaging surface in back-to-back disposition and having first and second opposite, mutually adjoining end portions; said bearing surface being of convex spherical shape to serve a condylar articulation function; said bone engaging surface being concave configured for fixation to the bone of a femoral condyle, and having major and minor segments extending over a respective end portion of said elongated body; said major segment being curved in each of three dimensions so as to be of concave substantially spherical shape concentric with said convex spherical shape; said minor segment being of substantially plane shape extending as a chord of said convex spherical shape; and said major segment having an elongated member projecting therefrom along a common radius of said convex and concave spherical shapes parallel with said minor segment.
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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) | 1997-05-23 | 1997-11-22 | 1998-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-23 | 2001-11-22 | 2002-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-23 | 2005-11-22 | 2006-05-24 | $7700.00 | Window Closed / Lapsed |