Prosthesis (i.e. – artificial body members) – parts thereof – or ai – Implantable prosthesis – Bone
Reexamination Certificate
1999-06-01
2001-06-05
Mancene, Gene (Department: 3732)
Prosthesis (i.e., artificial body members), parts thereof, or ai
Implantable prosthesis
Bone
Reexamination Certificate
active
06241772
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a plugging and centralising device for locating the stem of a prosthesis.
2. Description of the Prior Art
When using cement to locate the stem of a prosthesis in an medullary canal it is usual to plug the lower end of the canal to prevent cement extending along it beyond the stem of the prosthesis.
Such plugs are well known, for example as shown in GB 2 017 503 which shows a plug with ranks of resilient lugs which jam against the side wall of the cavity to prevent the bone cement from escaping downwards. Another type of plug is shown in GB 2 047 541 which has a mid-portion which serves as a seal against the walls of the canal and an upper portion which is open ended to define a recess formed by a series of petals which are intended to prevent extrusion of the plug back out of the open canal. Another plug is show in U.S. Pat. No. 5,766,178 which has deformable flanges.
It is also known to provide a centraliser for the distal end of the stem of a prosthesis, for example as shown in U.S. Pat. No. 5,092,892 in which there are resiliently deformable fins which engage the wall of the canal and an annular body portion which locates the tip end of the stem of the prosthesis. Another type of centraliser is shown in GB 1 409 053 which has an annular base member with a number of spring members extending therefrom. The annular portion receives the free end of the stem and slides only part way along it and the spring members act to centraliser the stem in the canal.
Plugs and centralisers are frequently used together.
SUMMARY OF THE INVENTION
The present invention is intended to provide a single device which will act as a plug and a centraliser or guide and which is easy to manufacture and use.
According to the present invention a device for plugging the medullary canal of a bone to prevent the passage of locating cement and for centralising or guiding the stem of a prosthesis comprises a main body portion adapted to engage the wall of the canal to act as a plug and having a centralising or guide opening to receive the stem of the prosthesis.
Thus, this device can replace the combination of known types of plugs and centralisers.
In one preferred embodiment the centralising or guide opening is adapted to engage and locate the stem at a position between up to one half of its length from its distal end.
In another alternative embodiment the centralising or guide opening is adapted to engage and locate the distal end of the stem of the prosthesis.
The opening may be constructed to extend through the main body portion and be adapted to allow the stem, when in place, to protrude beyond it.
In another construction the main body portion can include a cup, the open end of which provides the opening, the open end being adapted to engage the stem and the cup being deep enough to accept subsequent further inward movement of the stem.
The open end or ends of the opening can be reinforced.
The device can be made from any convenient material, for example metal but is preferably made from a synthetic material, for example polymethylmethacrylate (PMMA).
In any case, the material used is preferably resilient.
REFERENCES:
patent: 3712301 (1973-01-01), Sarnoff
patent: 3793650 (1974-02-01), Ling et al.
patent: 3982613 (1976-09-01), Wood
patent: 4067333 (1978-01-01), Reinhardt et al.
patent: 4753657 (1988-06-01), Lee et al.
patent: 4783192 (1988-11-01), Wroblewski et al.
patent: 5002580 (1991-03-01), Noble et al.
patent: 5057101 (1991-10-01), Dorr et al.
patent: 5092892 (1992-03-01), Ashby
patent: 5108437 (1992-04-01), Kenna
patent: 5171289 (1992-12-01), Tornier
patent: 5658351 (1997-08-01), Dudasik et al.
patent: 5725500 (1998-03-01), Micheler
patent: 5766178 (1998-06-01), Michielli et al.
patent: 5984968 (1999-11-01), Park
patent: 5997581 (1999-12-01), Khalili
patent: 2 017 503 (1979-10-01), None
patent: 2 047 541 (1980-12-01), None
Gie Graham Allan
Ling Robin Sydney Mackwood
Pichon Denis
Storer John Andrew
Timperley Andrew John
Benoist Girard SAS
Lerner David Littenberg Krumholz & Mentlik LLP
Mancene Gene
Robert Eduardo C.
LandOfFree
Plugging and centralized device for locating the stem of a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Plugging and centralized device for locating the stem of a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plugging and centralized device for locating the stem of a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2538086