Device for cutting a patella and method therefor
First Claim
1. A device for attachment to an everted patella for providing a horizontally level cutting surface for an oscillating saw used to cut off cartilage of the articular surface of the patella and a layer of bone of desired thickness for subsequent insertion into the patella of a prosthesis, said device comprising:
- a first attaching means for removable attachment to a portion of a patella;
a first leg extension having a first end mounting said first attaching means, and a second end remote from said first end;
a second attaching means for removable attachment to another portion of a patella different from that portion to which the first attaching means is attached;
a second leg extension having a first end mounting said second attaching means and a second end remote from said first end;
said first and second attaching means being mounted to their respective leg extensions such that they are spaced from each other to define therebetween a space in which is received a patella for attachment to said first and second attaching means;
a cutting support surface means fixedly connected to said second ends of said first and second leg extensions to thereby space said cutting support surface means from said first ends of said leg extensions and, therefore, to space said cutting support surface means from said first and second attaching means, said cutting support surface means defining a guide surface upon which is supportable an oscillating saw used to cut a patella in a cutting plane parallel to said cutting support surface means;
and a placement aid means mountable over said cutting support surface means for allowing the attachment of said first and second attaching means to a patella a desired distance below the articular surface of the patella, said placement aid means having an projecting positioning surface portion that at one end thereof is supportable by the articular surface of the everted patella, and means connected to the other end of said projecting surface portion for spacing said projecting surface portion from said cutting support surface means, whereby after attachment of said first and second attaching means to the everted patella after the distance from the articular surface thereto has been determined by said placement aid means, said placement aid means is removed to expose a cutting surface for an oscillating saw which cutting surface is positioned below the articular surface a desired distance to cut off the desired amount of cartilage and bone.
0 Assignments
0 Petitions
Accused Products
Abstract
A device is disclosed for cutting a portion of a patella during knee surgery in which the articular surface of the patella along with a portion of the bone of the patella is cut away for implantation of a prosthesis. The device disclosed provides a fixed clamping member and an adjustable clamping member which clamp the patella and space from the patella a support surface for an oscillating saw used in the cutting of the patella. The precise plane of cut is provided by the use of a placement aid which is used according to the method of the present invention. The placement aid positions the support surface a precise depth below the articular surface of the patella during the clamping procedure, which clamping procedure also horizontally levels the support surface and the device so that all cuts through the patella are made in a perfectly horizontal plane. Spacers are also provided which are mountable over the support surface and are used to allow for progressively deeper cuts to be made in the patella through parallel horizontal planes of cut by allowing interchange of one spacer for another of less thickness. Each spacer has its own flat surface that allows support of the oscillating saw thereon for cutting through the patella during that particular cut as defined by the thickness of the spacer used.
-
Citations
27 Claims
-
1. A device for attachment to an everted patella for providing a horizontally level cutting surface for an oscillating saw used to cut off cartilage of the articular surface of the patella and a layer of bone of desired thickness for subsequent insertion into the patella of a prosthesis, said device comprising:
-
a first attaching means for removable attachment to a portion of a patella; a first leg extension having a first end mounting said first attaching means, and a second end remote from said first end; a second attaching means for removable attachment to another portion of a patella different from that portion to which the first attaching means is attached; a second leg extension having a first end mounting said second attaching means and a second end remote from said first end;
said first and second attaching means being mounted to their respective leg extensions such that they are spaced from each other to define therebetween a space in which is received a patella for attachment to said first and second attaching means;a cutting support surface means fixedly connected to said second ends of said first and second leg extensions to thereby space said cutting support surface means from said first ends of said leg extensions and, therefore, to space said cutting support surface means from said first and second attaching means, said cutting support surface means defining a guide surface upon which is supportable an oscillating saw used to cut a patella in a cutting plane parallel to said cutting support surface means; and a placement aid means mountable over said cutting support surface means for allowing the attachment of said first and second attaching means to a patella a desired distance below the articular surface of the patella, said placement aid means having an projecting positioning surface portion that at one end thereof is supportable by the articular surface of the everted patella, and means connected to the other end of said projecting surface portion for spacing said projecting surface portion from said cutting support surface means, whereby after attachment of said first and second attaching means to the everted patella after the distance from the articular surface thereto has been determined by said placement aid means, said placement aid means is removed to expose a cutting surface for an oscillating saw which cutting surface is positioned below the articular surface a desired distance to cut off the desired amount of cartilage and bone. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A method for preparing the cutting of an everted patella in a horizontal plane of cut parallel to the articular surface of the patella for removing the cartilage and part of the bone of the patella for subsequent insertion of a prosthesis thereto, in which there is provided a device having a first attaching means and a second attaching means oppositely disposed to the first attaching means, and a cutting support surface spaced from and connected to the first and second attaching means for suport and movement therewith to provide a cutting surface for an oscillating saw used to cut the patella at a desired depth below the flat articular surface, said method comprising the steps of:
-
(a) affixing the first attaching means of the device to a portion of the patella at a depth below the flat articular surface which portion is below the part of the patella through which the oscillating saw is to cut the patella substantially parallel to the flat articular surface; (b) levelling the device and its cutting support surface along with the patella articular surface in a horizontal plane; and (c) affixing the second attaching means of the device after said step of levelling the device and cutting suport surface at a portion of the patella substantially diametrically opposite to that portion to which the first attaching means is affixed;
whereby the cutting support surface is readied for an oscillating saw to cut the patella at a desired depth thereof in a horizontal plane. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
-
-
21. A method for cutting off a portion of an everted patella to remove the cartilage thereof and a portion of the bone thereof, comprising the steps of:
-
(a) firmly holding the everted patella at location below the plane of cut; (b) mounting a support surface for an oscillating saw to the everted patella in front thereof opposite the portion of the patella where it is firmly held;
such that the support surface is positioned below the articular surface of the patella a desired depth;(c) positioning the everted patella and the support surface in a horizontal plane, said step of positioning comprising the levelling the support surface in a horizontal plane; (d) supporting the oscillating saw on the support surface at the desired depth below the articular surface; and (e) cutting through the patella in a horizontal plane to cut off a portion of the patella including the layer of cartilage and part of the bone thereof, whereby a horizontally level cut is made through the patella. - View Dependent Claims (22, 23, 24, 25, 26, 27)
-
Specification