DEVICE AND METHOD FOR PRODUCING HIP SPACERS

Abstract

The invention relates to a casting mold for producing a hip joint spacer, which comprises a head element comprising an upper shell and a lower shell, optionally a neck element, and a stem element, which comprises an upper shell and a lower shell, wherein the casting mold has a latching element, and an upper shell and a lower shell of the head element and/or of the stem element can be connected to one another by means of the latching element.

Claims

1. A casting mold for producing a joint spacer, comprising a head element, which comprises an upper shell and a lower shell, and a stem element, which comprises an upper shell and a lower shell, wherein the casting mold comprises a latching element, and an upper shell and a lower shell of the head element and/or of the stem element can be connected to one another by means of the latching element.

2. The casting mold according to claim 1, further comprising a form-fitting connecting element, wherein an upper shell and a lower shell of the head element and/or of the stem element can be connected to one another by means of the form-fitting connecting element.

3. The casting mold according to claim 1, wherein the latching element is designed as a tab.

4. The casting mold according to claim 1, wherein the head element and/or the stem element comprise(s) a plurality of similar latching elements.

5. The casting mold according to claim 1, wherein the latching element is arranged and configured to define a cavity for receiving excess bone cement dough in a completely assembled state of the casting mold.

6. The casting mold according to claim 1, which further comprises a neck element, which can be connected to the head element and to the stem element.

7. The casting mold according to claim 6, wherein the neck element further comprises a rib, which is arranged parallel to the central axis of the neck element, wherein the rib is arranged and configured to engage in a structure which is complementary to the rib and which is arranged on the head element or the stem element.

8. The casting mold according to claim 6, wherein the neck element comprises a slot arranged parallel to the central axis of the neck element and configured to enable the neck element to be bent apart or pressed together.

9. The casting mold according to claim 6, wherein the neck element is designed and configured to be combined with a pre-assembled head element and/or a pre-assembled stem element to create a completely joined state of the casting mold.

10. The casting mold according to claim 1, wherein the stem element comprises a lever element arranged and configured to move the upper shell and the lower shell of the stem element apart in order to release a latching element and/or connecting element arranged on the stem element.

11. The casting mold according to claim 1, wherein the upper shell and/or the lower shell of the head element are of multipart design.

12. The casting mold according to claim 11, wherein the latching element is designed as a tab and is arranged on the head element, and wherein the tab further comprises a fastening element arranged to engage in a structure of the head element that is complementary to the fastening element in order to hold together the multipart upper shell and/or lower shell of the head element.

13. A kit for producing a hip joint spacer, comprising the casting mold according to claim 1 and a metal core configured to be introduced into the stem element.

14. The kit according to claim 13, wherein the metal core comprises a plurality of wing elements in order to centrally align the metal core within the stem element.

15. A kit for producing a spacer, comprising the casting mold according to claim 1, wherein the kit comprises a plurality of head elements, neck elements and/or stem elements in different sizes, which can preferably be combined with one another as desired.

Description

FIGURES

[0089] FIG. 1 shows an embodiment of the invention by way of example. A casting mold 100 comprises a head element 110 formed from an upper shell 120 and a lower shell 130. The upper shell 120 and the lower shell 130 are held together by means of a latching element 101. In the example shown in FIG. 1, six latching elements in the form of tabs, which are each designed as snap hooks, are attached to the upper shell 120. The casting mold 100 further comprises a stem clement 150 which is formed, similarly to the head element, from an upper shell and a lower shell. Similar to the head element, the stem element 150 also comprises latching elements 101 which are designed as tabs with snap hooks and hold the upper shell and the lower shell of the stem element 150 together in a form-fitting manner. Furthermore, a lever element 151 is arranged at the distal part of the stem element 150 to enable disassembly of the stem element by the lever element 151 being used to push the upper shell and the lower shell of the stem element apart. This facilitates a simpler removal of the spacer produced using the casting mold.

[0090] A neck element 140 is arranged between the head element 120 and the stem element 150, which neck element 140 connects the head clement 120 to the stem element 150.

[0091] FIG. 2 shows a cross section through a casting mold according to the invention in the region of the head element. The upper shell 120 comprises a latching element 101 which is designed here as a tab-like snap hook. The latching element holds the upper shell 120 and lower shell 130 together by means of a form-fitting connection.

[0092] In addition to the latching element 101, the upper shell 120 is connected to the lower shell 130 via a connecting clement 102, which is embodied here as a pair of mutually engaging ribs, which are arranged in each case on the upper shell 120 and lower shell 130.

[0093] FIG. 3 shows a cross section through a casting mold according to the invention in the region of the stem element. Similarly as shown in FIG. 2 for the head element, the stem clement also comprises a latching element 101 which is also designed as a tab-like snap hook. A plurality of such latching elements can be provided on both sides of the stem element, for example at the peripheral edge of the upper shell or the lower shell of the stem element. In addition, as shown in FIG. 2 for the head element, connecting elements 102 are also available for the stem clement, which, independently of the latching element 101, connect the upper shell to the lower shell of the stem clement. In the example shown here, the connecting elements 102 are mutually engaging ribs on the upper shell and the lower shell of the stem element.

[0094] FIG. 4 shows an exploded drawing of a casting mold according to the invention, and a joint spacer 400 arranged therein, which can be produced using the casting mold. A snap hook is arranged as a latching element 101 on the upper shell 120 of the head clement 110. In the example shown here, the lower shell 130 of the head element 110 has a two-part design, wherein the two parts of the lower shell 130 can be connected to one another with the aid of a further latching clement 171, which is designed as a snap hook, and additionally with the aid of a further connecting element 172, which in this example is designed as a tongue and groove according to the tongue and groove connection principle.

[0095] Furthermore, a neck element 140 is provided, which in each case is connected in a form-fitting manner to the head clement 110 and the stem element 150. The neck element 140 here has the shape of a slotted ring, and comprises two ribs 190 arranged in parallel, which in each case are arranged parallel to the ring axis of the neck clement 140. In the example shown here, the ring clement 140 comprises two pairs of such ribs arranged opposite each other on the outside of the ring element. The two parts of the lower shell 130 of the head element 110 each comprise structures which are complementary to said ribs 191 and which facilitate a form-fitting connection of the head clement 110 to the ring element 140. In the example shown here, the rib pairs 190 can be inserted into the structures 191, similar to those that are known, for example, from cable lugs.

[0096] FIG. 5 shows an isometric view of a casting mold according to the invention. The head clement 110 comprises a plurality of latching elements designed as tabs 101, which connect the upper shell 120 to the lower shell 130 of the head element with the aid of a snap hook. In addition, further connecting elements are attached on some of the tabs 103 and engage in complementary structures 104 attached to the lower shell 130 of the head element. The connecting elements 103 connect the upper shell 120 to the lower shell 130 of the head element. The connection of the connecting elements 103 to the complementary structures 104 in this example is designed as a tongue and groove according to the tongue and groove connection principle, which in this case prevents the lateral rotation of the upper shell 120 with respect to the lower shell 130.

[0097] The head clement also comprises openings 500 which serve for venting when the casting mold is filled with bone cement dough. Such openings can also be provided on the stem clement 150.

[0098] The stem clement 150 has latching elements 101 designed as tabs which define a cavity 180 between these tabs and the wall of the stem element 150. This cavity 180 can optionally receive bone cement dough leaking between the upper shell 160 and the lower shell 170 without said dough reaching the hand of the user of the casting mold.

[0099] FIG. 6a shows a spacer that can be produced using a casting mold described herein after the head element and the stem element have been removed. The neck element 140 is still remaining on the spacer 400. The neck element 140 comprises a slot 141 which interrupts the wall of the neck clement. This allows deformation of the neck clement 140. Furthermore, the neck clement 140 comprises a stop 142 arranged laterally circumferentially and orthogonally to the ring axis of the neck element 140. The stop 142 is arranged and configured to define, during assembly of the casting mold 140, a desired distance between the neck element and head element 110 or between the neck element 140 and the stem element 150.

[0100] FIG. 6b shows how, by bending the neck element 140 apart, it can be removed from the spacer 400.

[0101] FIG. 7a shows a step of assembling a casting mold according to the invention. A

[0102] neck element 140 is inserted into a head clement 110, wherein the upper shell 120 and the lower shell 130 of the head clement are already connected. Ribs 190 arranged on the neck element are inserted into complementary structures 191 arranged on the head clement 110.

[0103] FIG. 7b shows a step of assembling a casting mold according to the invention. The neck clement has a stop 142. The neck clement 140 is inserted into the head element 110, wherein the stop 142 limits the depth of the insertion.

[0104] FIG. 8a shows a further step of assembling a casting mold according to the invention. A suitable dispensing device is used to introduce bone cement dough 300 into the stem element 150, the upper shell and lower shell of which are connected to one another, until the interior thereof is completely filled with bone cement dough.

[0105] FIG. 8b shows a step of assembling a casting mold according to the invention. A metal core 200 comprising a plurality of wing elements 210, is introduced into the stem element already filled with bone cement dough 150. The wing elements 210 are arranged and configured to facilitate a centered arrangement of the metal core 200 within the stem element 150.

[0106] FIG. 9 shows a step of assembling a casting mold according to the invention. A dispensing device is used to introduce bone cement dough 300 into the head element, while the upper shell and the lower shell of the head element are already connected to one another, and the head element is connected to the neck element 140 as described above.

[0107] FIG. 10 shows a further step of assembling a casting mold according to the invention. After the steps described above have been carried out, the stem element 150 filled with bone cement dough and provided with a metal core 210 is inserted into the neck element 140, which in turn is connected to the head element. The head element is likewise already filled with bone cement dough.

LIST OF REFERENCE SIGNS

[0108] 100 Casting mold [0109] 101 Latching element [0110] 102 Connecting element [0111] 103 Fastening element [0112] 104 Structure which is complementary to the fastening element 103 [0113] 110 Head element [0114] 120 Upper shell of the head element [0115] 130 Lower shell of the head element [0116] 140 Neck element [0117] 141 Slot [0118] 142 Stop [0119] 150 Stem element [0120] 151 Lever element [0121] 160 Upper shell of the stem element [0122] 170 Lower shell of the stem element [0123] 171 Further latching element [0124] 172 Further connecting element [0125] 180 Cavity [0126] 190 Rib [0127] 191 Structure which is complementary to the rib 190 [0128] 200 Metal core [0129] 210 Wing element [0130] 300 Bone cement dough [0131] 400 Spacer [0132] 500 Opening