Spacer mould and method for producing hip spacers

Patent metadata

Field	Value
Publication number	US-10399248-B2
Application number	US-201615079096-A
Country	US
Kind code	B2
Filing date	Mar 24, 2016
Priority date	Mar 27, 2015
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A spacer mold and method for producing a hip spacer, the spacer mold comprises a base element ( 1 ), in which a hollow mold is provided as negative image of one side of a femoral stem of the spacer to be generated, whereby a recess connected to the hollow mold is arranged on the proximal end of the hollow mold in the base element. The spacer mold further comprises a semi-spherical insert ( 2 ) comprising a femoral head mold as negative image of one side of a femoral head of the spacer to be generated, whereby the semi-spherical insert ( 2 ) is to be arranged in the recess in the base element ( 1 ). Further, the spacer mold comprises an adapter insert ( 3 ) that is designed as a hollow body that is open on two sides and that is or can be arranged in the recess of the base element ( 1 ) between the semi-spherical insert ( 2 ) and the hollow mold such that the recess exerts a pressure onto the adapter insert ( 3 ) and the semi-spherical insert ( 2 ). Moreover, the spacer mold comprises a punch ( 4 ) that comprises a punch hollow mold in the form of the negative image of the remaining femoral stem and that is arranged on or can be pressed onto the top side of the base element ( 1 ).

First claim

The invention claimed is:

1. A spacer mould for producing a hip spacer, the spacer mould comprising:
a base element having a height defined between a top side and a bottom side, wherein a hollow mould is provided on the top side of the base element as a negative image of one side of a femoral stem of the hip spacer to be generated, wherein a recess is provided on the top side of the base element, arranged on an end of the hollow mould in the base element and connected to the hollow mould, wherein the top side of the base element comprises an inclined surface, adjacent to the hollow mound and the recess, that slopes upwardly from a perimeter of the top side to a perimeter of the hollow mould and a perimeter of the recess;
a semi-spherical insert comprising a femoral head mould as a negative image of one side of a femoral head of the hip spacer to be generated, wherein the semi-spherical insert is arrangeable in the recess of the base element at a side of the recess that is opposite to the hollow mould, such that the femoral head mould is aligned in a direction towards the hollow mould;
an adapter insert designed as a hollow body that is open on two sides and that is arrangeable in the recess of the base element between the semi-spherical insert and the hollow mould such that the recess exerts a pressure onto the adapter insert and the semi-spherical insert when the adapter insert and the semi-spherical insert are inserted into the recess, wherein the hollow body of the adapter insert connects the femoral head mould of the semi-spherical insert to the hollow mould in the base element;
a punch comprising a punch hollow mould in a form of the negative image of another side of the femoral stem and that is at least one of arrangeable and pressable onto a top side of the base element;
a first cutting edge bounding a first connection of the hollow mould of the base element to the punch hollow mould of the punch is arranged on at least one of an edge of the hollow mould of the base element and an edge of the punch hollow mould of the punch; and
a second cutting edge bounding a second connection of the femoral head mould to the opening of the hollow body of the adapter insert is arranged on at least one of an edge of the femoral head mould and an edge of said opening of the hollow body of the adapter insert to the femoral head mould.

2. The spacer mould according to claim 1 , wherein the femoral head mould of the semi-spherical insert comprises a circumferential edge and the semi-spherical insert has an inclined surface around the circumferential edge of the femoral head mould that slopes downwardly from the circumferential edge to an outer perimeter of the inclined surface.

3. The spacer mould according to claim 1 , wherein at least one of: i) the first cutting edge bounds the hollow mould, in its entirety, in the base element, ii) the second cutting edge bounds the femoral head mould, in its entirety, in the semi-spherical insert, and iii) the entire hollow body of the adapter insert, in the connection to the femoral head mould, is bounded by at least one cutting edge of the first and second cutting edges.

4. The spacer mould according to claim 1 , wherein the base element comprises, on the bottom side, a planar support surface or a pedestal for set-up of the spacer mould on a planar support.

5. The spacer mould according to claim 1 , wherein the adapter insert is a two-part adapter insert or a multi-part adapter insert, wherein parts of the adapter insert are attachable to each other or placeable against each other, wherein the first and second cutting edges are provided on the parts of the adapter insert, wherein the first and second cutting edges are arranged on the edges of moulds forming the hollow body that form the connections of the hollow body in the adapter insert.

6. The spacer mould according to claim 1 , wherein the base element is fabricated from plastic material that is elastic such that the semi-spherical insert and the adapter insert are insertable into the recess of the base element.

7. The spacer mould according to claim 1 , wherein the recess of the base element has a circumference that is smaller than a circumference of the semi-spherical insert with the adapter insert contacting against the semi-spherical insert.

8. The spacer mould according to claim 1 , wherein the semi-spherical insert is provided as a single part.

9. The spacer mould according to claim 1 , wherein the width of the semi-spherical insert surrounding the edge of the femoral head mould is between 5 mm and 45 mm.

10. The spacer mould according to claim 1 , wherein ventilation openings are provided in the punch or through-going ventilation openings are provided in the punch hollow mould.

11. The spacer mould according to claim 1 , wherein the spacer mould comprises no filling openings for adding PMMA bone cement.

12. The spacer mould according to claim 1 , wherein the spacer mould comprises at least one insert for at least one of the hollow mould and the punch hollow mould that is insertable into at least one of the hollow mould and the punch hollow mould such that at least one of a size and a shape of the femoral stem of the hip spacer to be generated is varied by means of the at least one insert.

13. A spacer mould for producing a hip spacer, the spacer mould comprising:
a base element, in which a hollow mould is provided as a negative image of one side of a femoral stem of the hip spacer to be generated, wherein a recess is arranged on an end of the hollow mould in the base element and is connected to the hollow mould;
a semi-spherical insert comprising a femoral head mould as a negative image of one side of a femoral head of the hip spacer to be generated, wherein the semi-spherical insert is arrangeable in the recess of the base element at a side of the recess that is opposite to the hollow mould, such that the femoral head mould is aligned in a direction towards the hollow mould;
an adapter insert designed as a hollow body that is open on two sides and that is arrangeable in the recess of the base element between the semi-spherical insert and the hollow mould such that the recess exerts a pressure onto the adapter insert and the semi-spherical insert when the adapter insert and the semi-spherical insert are inserted into the recess, wherein the hollow body of the adapter insert connects the femoral head mould of the semi-spherical insert to the hollow mould in the base element;
a punch that comprises a punch hollow mould in a form of the negative image of another side of the femoral stem and that is at least one of arrangeable and pressable onto a top side of the base element;
a first cutting edge bounding a first connection of the hollow mould of the base element to the punch hollow mould of the punch is arranged on at least one of an edge of the hollow mould of the base element and an edge of the punch hollow mould of the punch; and
a second cutting edge bounding a second connection of the femoral head mould to the opening of the hollow body of the adapter insert is arranged on at least one of an edge of the femoral head mould and an edge of said opening of the hollow body of the adapter insert to the femoral head mould,
wherein the spacer mould comprises no filling openings for adding PMMA bone cement.

Assignees

• Heraeus Medical Gmbh

Inventors

• Wüst Edgar
• Vogt Sebastian

Classifications

• A61F2310/00353

  Bone cement, e.g. polymethylmethacrylate or PMMA · CPC title

• A61F2002/30693

  Air venting means · CPC title

• A61F2002/30672

  temporary · CPC title

• A61F2002/30616

  Sets comprising a plurality of prosthetic parts of different sizes or orientations · CPC title

• A61F2/36

  Femoral heads {; Femoral endoprostheses} · CPC title