Patent EP0941719A2 successfully refreshed from Google Patents.
EP0941719A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Four compartment knee
Assignee: Bristol Myers Squibb Co
•
Filing: 1999-03-09
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Granted: —
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Expires: 2019-03-09
Abstract
Abstract A femoral knee implant includes a fourth compartment of articulation. The superior posterior articulating surface is achieved by first increasing the thickness of the superior posterior condylar portion ofthe femoral component to widen the superior posterior edge of the posterior condyle. Second, the newly created surface at the superior posterior condyle is smoothly rounded to provide an articular surface with no sharp changes in the surface contours. In one embodiment, the fourth articular compartment of this invention is provided in a one piece femoral design. In another embodiment, it is provided as a modular addition to an existing prior art femoral component. In another embodiment, the fourth compartment is combined with a posterior stabilized (PS) TKR design that includes a tibial post and cooperating femoral cam characterized by low engagement of the cam on the spine.
Inventors
- 👤 John Insall
- 👤 Mark Heldreth
- 👤 Vince Webster
- 👤 Steve Zawadski
- 👤 Roy Yoshikazu Hori
- 👤 Kyoko Ohkuni
- 👤 Audrey Beckman
- 👤 William Rohr
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 21:02
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/38; A61F2/3859; A61F2/3886; A61F2/30721; A61F2/30734; A61F2002/30736
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
134 words
A prosthetic knee implant including: a tibial component comprising a tibial articular surface; and a femoral component comprising arcuate medial and lateral condyles joined together
to form a patellar flange, each of the medial and lateral condyles including a
distal condyle, a posterior condyle, and a superior condyle, the superior
aspects of the posterior condyles being extended toward the anterior flange
and the superior condyles being formed on the superior aspect such that the
patellar flange, the distal condyles, the posterior condyles, and the superior
condyles define a smooth articular surface extending around the exterior of
the implant for articulation with the tibial articular surface, the superior
condyles extending the articular surface back toward the patellar flange to
accommodate flexion of the femoral component relative to the tibial
component of at least 160 degrees.
Claim 2
Dependent Claim
83 words
The knee implant of claim 1 wherein the femoral component further includes a hollow
interior bordered by an anterior box surface opposite the patellar flange, distal box
surfaces opposite the distal condyles, and posterior box surfaces opposite the
posterior condyles, the anterior and distal box surfaces being joined by an anterior
chamfer box surface, the distal and posterior box surfaces being joined by a posterior
chamfer box surface, the included angle between the distal and posterior box surfaces
being less than 90 degrees.
Claim 3
Dependent Claim
90 words
The knee implant of claim 1 wherein the femoral component further includes a hollow
interior bordered by an anterior box surface opposite the patellar flange, distal box
surfaces opposite the distal condyles, and posterior box surfaces opposite the
posterior condyles, the anterior and distal box surfaces being joined by an anterior
chamfer box surface, the distal and posterior box surfaces being joined by a posterior
chamfer box surface, the distal condyles having a tangent at their most prominent
distal point, the distal box surface diverging posteriorly away from the tangent.
Claim 4
Dependent Claim
107 words
The knee implant of claim 1 wherein the tibial component includes a spine extending
from the tibial articular surface, the spine having a top surface furthest from the tibial
articular surface and an articular surface, and the femoral component includes a cam
between the superior posterior condyles, the cam having an articular surface, the cam
articular surface contacting the spine articular surface at varying vertical locations as
the femoral and tibial components are flexed relative to one another beyond 90
degrees, the distance from the contact between the cam and spine articular surfaces
to the spine top surface being greater at 130 degrees than at 90 degrees.
Claim 5
Dependent Claim
39 words
The knee implant of claim 4 wherein the distance from the contact between the cam
and spine articular surfaces to the spine top surface is approximately the same for
angles of flexion from 130 to 160 degrees of flexion.
Claim 6
Dependent Claim
78 words
The knee implant of claim 1 wherein the tibial component includes a spine extending
from the tibial articular surface, the spine having a top surface furthest from the tibial
articular surface and the spine having a spine articular surface, the femoral component
includes a cam between the superior posterior condyles, the cam has a non-cylindrical
articular surface with a first spine contacting portion and a second spine contacting
portion located further posteriorly than the first spine contacting portion.
Claim 7
Dependent Claim
74 words
The knee implant of claim 6 wherein the first spine contacting portion has a first radius
defining a first circle and the second spine contacting portion has a second radius defining a
second circle, the first spine contacting portion being an arc of the first circle and the second
spine contacting portion being an arc of the second circle, the second spine contact portion
extending further posteriorly than the perimeter of the first circle.
Claim 8
Dependent Claim
28 words
The knee implant of claim 6 wherein the cam articular surface has a curved surface
whose radius increases from the first contact portion to the second contact portion.
Claim 9
Dependent Claim
43 words
The knee implant of claim 6 wherein the first spine contact portion has a radius and
the second spine contact portion has a radius, the radius of the second spine contact portion
being larger than the radius of the first spine contact portion.
Claim 10
Dependent Claim
38 words
The knee implant of claim 9 wherein the cam has a third spine contacting portion
located further posteriorly than the second spine contacting portion and having a third
radius, the third radius being smaller than the second radius.
Claim 11
Dependent Claim
19 words
The knee implant of claim 10 wherein the third spine contacting portion extends
posteriorly further than the posterior condyles.
Claim 12
Dependent Claim
92 words
A module for use with a femoral knee implant having an interior box and an articular
surface for articulation with a tibial surface, the module comprising a back surface and a top
surface, the back surface being shaped to seat against a portion of the box, the top surface
being shaped to form an extension of the articular surface, the top surface blending
functionally with the articular surface to allow further articulation of the femoral implant on
the tibial surface when the back surface is seated on a portion of the box.
Claim 13
Dependent Claim
103 words
A femoral knee implant for articulation with a tibial surface, the femoral knee implant
comprising: an articular surface for articulation with the tibial surface; a box defining the interior surfaces of the implant; and a module comprising a back surface and a top surface, the back surface being shaped
to seat against a portion of the box, the top surface being shaped to form an
extension of the articular surface, the top surface blending functionally with
the articular surface to allow further articulation of the femoral implant on the
tibial surface when the back surface is seated on a portion of the box.
Claim 14
Dependent Claim
108 words
The femoral knee implant of claim 13 further comprising arcuate medial and lateral
condyles joined together to form a patellar flange, each of the medial and lateral condyles
including a distal condyle and a posterior condyle, the patellar flange, the distal condyles, and
the posterior condyles defining the articular surface extending around the exterior of the
implant, each posterior condyle including an apex at its highest point, the articular surface
terminating at the apexes of the posterior condyles, the articular surface being defined by a
radius R near the apexes, the top surface blending with the radius R to form a functionally
smooth continuation of the articular surface.
References Cited (Backward Citations)
No citation records indexed.
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