EP0359457A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A prosthesis
Assignee: Individual
•
Filing: 1989-09-05
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Granted: —
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Expires: 2009-09-05
Abstract
Abstract A prosthesis, eg the femoral component of an artificial hip joint, comprising a proximal portion (1) which is shaped to fit within the medullary canal of the metaphysis of the bone and a distal portion (2) shaped to fit withn the medullary canal of the diaphysis of the bone. The proximal and distal portions (1,2) are separately formed and fit together by means of a shaft (8) on the distal portion (2) which slides within a hole (7) in the proximal portion (1). The two portions (1,2) may thus be independently selected to provide the desired fit within the bone. Movement of the proximal portion (1) on the stem (8) of the distal portion (2) prevents the latter being forced into a wedge fit with the diaphysis when load is applied to the proximal portion (1). Load transfer between the proximal portion (1) and the metaphysis is thus maintained so avoiding bone resorption.
Inventors
- 👤 Peter David Mclardy-Smith
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 06:36
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/32; A61F2/36; A61F2/3662; A61F2/367; A61F2/3672; A61F2002/30001; A61F2002/30316; A61F2002/30329; A61F2002/30331; A61F2002/30354; A61F2002/30535; A61F2002/30604; A61F2002/30616; A61F2002/30667; A61F2002/307; A61F2/3609; A61F2002/3625; A61F2002/3631; A61F2002/365; A61F2002/3678; A61F2002/3694; A61F2220/00; A61F2220/0025; A61F2220/0033; A61F2250/00; A61F2250/0058; A61F2250/0081
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
80 words
A prosthesis for implantation in a bone comprising a proximal portion (1) shaped to fit within the medullary canal of the metaphysis of the bone and to project from the end of the bone and a distal portion (2) shaped to fit within the medullary canal of the diaphysis of the bone, the proximal and distal portions (1,2) being separately formed and arranged to fit together so they may be independently selected to provide the optimum fit within the bone.
Claim 2
Dependent Claim
80 words
A prosthesis for implantation in a bone comprising a proximal portion (1) shaped to fit within the medullary canal of the metaphysis of the bone and to project from the end of the bone and a distal portion (2) shaped to fit within the medullary canal of the diaphysis of the bone, the proximal and distal portions (1,2) being separately formed and arranged to fit together so they may be independently selected to provide the optimum fit within the bone.
Claim 3
Dependent Claim
35 words
A prosthesis as claimed in claim 1 in which the proximal portion (1) has a neck (4) and means for attaching a head portion (5), eg the ball of a ball and socket joint, thereto.
Claim 4
Dependent Claim
44 words
A prosthesis as claimed in claim 1 or 2 in which the proximal and distal portions (1,2) are arranged such that, when fitted together, they can move relative to each other in a direction which, in use, corresponds to the length of the bone.
Claim 5
Dependent Claim
27 words
A prosthesis as claimed in claim 3 in which up to 5mm of movement is permitted between the proximal and distal portions (1,2) in the said direction.
Claim 6
Dependent Claim
40 words
A prosthesis as claimed in any preceding claim in which the proximal and distal portions (1,2) are arranged to fit together by means of a stem (8) on one portion which fits within a hole (7) in the other portion.
Claim 7
Dependent Claim
22 words
A prosthesis as claimed in claim 3 and 5 in which the stem (8) is a sliding fit within the hole (7).
Claim 8
Dependent Claim
18 words
A prosthesis as claimed in any preceding claim which comprises the femoral component of an artificial hip joint.
Claim 9
Dependent Claim
27 words
A plurality of proximal and distal portions (1,2) of different sizes which may be interchangeably fitted together to provide a prosthesis as claimed in any preceding claim.
Claim 10
Dependent Claim
76 words
A method of implanting a prosthesis as claimed in claim 1 within a bone comprising the steps of: selecting proximal and distal portions (1,2) to provide the desired fit within the bone and implanting the prosthesis with the two portions (1,2) fitted together such that the proximal portion (1) fits within the medullary canal of the metaphysis of the bone and the distal portion (2) fits within the medullary canal of the diaphysis of the bone.
Claim 11
Dependent Claim
74 words
A method as claimed in claim 9 using a prosthesis as claimed in claim 3 in which movement is permitted between the proximal and distal portions (1,2) in a direction corresponding to the length of the bone such that, following implantation, should the proximal portion (1) move within the metaphysis when load is applied to the prosthesis such movement is permitted without forcing the distal portion (2) into a wedge fit with the diaphysis.
References Cited (Backward Citations)
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