EP0135319A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Knee prosthesis
Assignee: Arthroplasty Research & Development Pty Ltd
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Filing: 1984-07-30
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Granted: —
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Expires: 2004-07-30
Abstract
Abstract A knee prosthesis which comprises a femoral component and a tibial component, for use in a procedure involving removal of the cruciate ligaments, each component extending across the width of the joint, the femoral component presenting a pair of bearing convexities separated by a groove and curving posteriorly and upwardly for flexion, the tibial component comprising a coacting pair of bearing concavities separated by a dome, and presented as a bearing pad or pads supported on a base, the skeleto-prosthetic interface of each component presenting one or more keying element(s) adapted to penetrate the bone.
Inventors
- 👤 Charl Johannes Grobbelaar
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 09:15
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/38; A61F2/3886
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
95 words
A knee prosthesis which comprises a femoral component and a tibial component, for use in a procedure involving removal of the cruciate ligaments, each component extending across the width of the joint, the femoral component presenting a pair of bearing convexities separated by a groove and curving posteriorly and upwardly for flexion, the tibial component comprising a coacting pair of bearing concavities separated by a dome, and presented as a bearing pad or pads supported on a base, the skeleto-prosthetic interface of each component presenting one or more keying element(s) adapted to penetrate the bone.
Claim 2
Dependent Claim
95 words
A knee prosthesis which comprises a femoral component and a tibial component, for use in a procedure involving removal of the cruciate ligaments, each component extending across the width of the joint, the femoral component presenting a pair of bearing convexities separated by a groove and curving posteriorly and upwardly for flexion, the tibial component comprising a coacting pair of bearing concavities separated by a dome, and presented as a bearing pad or pads supported on a base, the skeleto-prosthetic interface of each component presenting one or more keying element(s) adapted to penetrate the bone.
Claim 3
Dependent Claim
36 words
A knee prosthesis as claimed in claim 1, in which the keying elements are narrow and deep, their short dimensions extending transversely in the joint and their longer dimensions extending posteriorly and anteriorly in the joint.
Claim 4
Dependent Claim
40 words
A knee prosthesis as claimed in eiher one of claims 1 or 2, in which the tibial component comprises a bearing pad locked in an adjustable position on a base, the base carrying the keying elements and supporting the pad.
Claim 5
Dependent Claim
30 words
A knee prosthesis as claimed in claim 3, in which the pad is selected from materials giving particularly suitable properties as a bearing surface in coaction with the femoral component.
Claim 6
Dependent Claim
55 words
A knee prosthesis as claimed in claim 4, in which the pad is furthermore selected from materials which will show a suitable degree of plastic flow under compressive forces in use so as to flow into locking or gripping serrations or other formations over a period of time to enhance attachment to the base plate.
Claim 7
Dependent Claim
42 words
A knee prosthesis as claimed in any one of claims 3 to 5, in which the base has undercut keyways or grooves into which matching formations of the bearing pad can be slid so as to key the pad onto the base.
Claim 8
Dependent Claim
37 words
A knee prosthesis as claimed in claim 6, in which there is further provision for screw insertion to lock the bearing pad in position in such keyways or grooves to provide security of placement of the bad.
Claim 9
Dependent Claim
50 words
A knee prosthesis as claimed in claim 7, in which the pad and base are adopted to facilitate the relative positions of the bearing pad and base in which the former is locked or secured with respect to the latter being adjustable within a suitable range during the operative procedure.
Claim 10
Dependent Claim
34 words
A knee prosthesis as claimed in any one of claims 1 to 8, in which the dome is provided with multilateral symmetry about a vertical axis passing through the centre of the tibial component.
Claim 11
Dependent Claim
25 words
A knee prosthesis as claimed in any one of claims 1 to 9, in which the skeleto-prosthetic interfaces are coated with a biologically inert material.
Claim 12
Dependent Claim
16 words
A knee prosthesis as claimed in claim 10, in which the coating material is a ceramic.
Claim 13
Dependent Claim
24 words
A knee prosthesis as claimed in either one of claims 10 or 11, in which the coating is provided with a coarse surface finish.
Claim 14
Dependent Claim
30 words
A knee prosthesis as claimed in any one of claims 10 to 12, in which the bearing surfaces are provided in a non-porous ceramic of fine grain and high polish.
Claim 15
Dependent Claim
35 words
A knee prosthesis as claimed in any one of claims 1 to 13, in which the posterior portion has the groove removed into an opening which separates the two bearing convexities in the posterior region.
Claim 16
Dependent Claim
40 words
A knee prosthesis as claimed in any one of claims 1 to 14, in which the bearing convexities have surfaces which, in transverse vertical planes are flat and inclined to the horizontal at an angle of between 0° and 30°.
Claim 17
Dependent Claim
38 words
A knee prosthesis as claimed in any one of claims 1 to 15, in which the anterior portion presents a high polished and somewhat hollowed surface which leads into the groove as a bearing surface for the patella.
Claim 18
Dependent Claim
31 words
A knee prosthesis as claimed in any one of claims 3 to 16, in which a set of alternative bearing pads of varying thickness are provided in combination with the prosthesis.
Claim 19
Dependent Claim
29 words
A knee prosthesis as claimed in any one of claims 1 to 17, which requires no more than a two centimetre gap to be opened up at the joint.
Claim 20
Dependent Claim
14 words
A knee prosthesis substantially as herein described and as illustrated in the accompanying drawings.
Claim 21
Dependent Claim
14 words
A knee prosthesis substantially as herein described and as illustrated in the accompanying drawings.
References Cited (Backward Citations)
No citation records indexed.
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