Device and method for producing knee spacer components

0001The invention relates to a device for producing a knee spacer component of a knee spacer, that is to say a femur component or a tibia component, by hardening bone cement dough. The knee spacer or the tibia component and the femur component are provided as temporary placeholders to temporarily replace a knee joint or part of a knee joint comprising an articulating surface of the knee joint in the medical field of application. The tibia component and the femur component are preferably suitable and provided for the temporary replacement of a knee joint. The invention also relates to a method for producing a knee spacer component of a knee spacer, that is to say a femur component or a tibia component, with such a device. The invention thus relates to a device and a method for producing knee spacer components. The device is intended for the production of knee spacer components by the OR staff before the knee spacer is inserted, that is, before the actual operation. The term knee spacer components is understood to mean the tibia component and the femur component of articulating knee spacers.

0002Knee joint endoprostheses are being implanted on a large scale around the world. Unfortunately, it happens in a small percentage that knee joint endoprostheses are colonized by microbial germs, especially Gram-positive bacteria and Gram-negative bacteria and, to a very small extent, by yeasts and fungi. These microbial germs, mainly typical skin germs such as Staphylococcus aureus and Staphylococcus epidermidis, can get into the patient during a surgical operation (OP). In addition, it is also possible for microbial germs to reach hematogenous joint endoprostheses. When joint endoprostheses are colonized with microbial germs, the surrounding bone and soft tissue is also infected and damaged by the microbial germs.

0003The state of the art are primarily two treatment methods for infected joint endoprostheses, the one-stage septic revision and the two-stage septic revision. In the case of a one-step revision, the infected joint endoprosthesis is first removed within an operation , then radically debrided and then a revision joint endoprosthesis is implanted.

0004In the case of two-stage septic revisions, the infected knee joint endoprosthesis is first removed in a first operation, then it is debrided and then a knee spacer is implanted. A knee spacer has a tibia component and a femur component and is basically modeled on knee joint endoprostheses in shape and size. The tibia component has a shaft and a tibia plateau, the tibia plateau forming a sliding surface or rolling surface of the knee joint and the shaft being able to be anchored in the tibia. The femoral component has a shaft for anchoring in the femur and two condyles for rolling on the tibial plateau. The tibial component and the femoral component are anchored to the respective bone with bone cement, for example anchored to the distal femur or in the femoral canal for the femoral component and anchored to the proximal tibia or in the tibial canal for the tibial component with the shaft. The knee spacer remains in the patient for up to several weeks until the inflammation has subsided and the clinical markers of inflammation have receded. The knee spacer is then removed in a second operation and, after renewed debridement, a revision knee joint endoprosthesis is implanted.

0005In the case of knee spacer components, antibiotics are added to the cement powder before the actual knee spacer production. With this antibiotically modified bone cement powder, a bone cement dough is then produced by admixing monomer liquid and knee spacer components are cast from this bone cement dough, which then harden by polymerization with the aid of the monomer liquid added to the cement powder. The bone cement dough essentially includes the antibiotics. The antibiotic particles in the areas close to the surface are released when exposed to body fluids such as wound exudate. The release of active ingredients is initially highest and then decreases over the course of several days.

0006In the <patcit id="pcit0001" dnum="WO2016205077A1"><text>WO 2016/205077 A1</text></patcit> and the <patcit id="pcit0002" dnum="US8900322B2"><text>US 8 900 322 B2</text></patcit> describes knee spacers with a rinsing function. It is also known to use knee spacers equipped with antibiotics. Knee spacers, PMMA bone cement powder, antibiotics and monomer liquid can be manufactured, for example with a spacer shape, such as those in the patents<patcit id="pcit0003" dnum="DE102015104704B4"><text>DE 10 2015 104 704 B4</text></patcit>, <patcit id="pcit0004" dnum="US7789646B2"><text>US 7 789 646 B2</text></patcit>, <patcit id="pcit0005" dnum="US8801983B2"><text>US 8 801 983 B2</text></patcit> or <patcit id="pcit0006" dnum="EP2617393B1"><text>EP 2 617 393 B1</text></patcit> are described. On the other hand, it is also common to use knee spacers that are industrially prefabricated from bone cement.

0007The patent <patcit id="pcit0007" dnum="EP2931180B1"><text>EP 2 931 180 B1</text></patcit> discloses a cement mold for making a tibial component of a knee spacer suitable for the delivery of antibiotics. The patent<patcit id="pcit0008" dnum="EP3143963B1"><text>EP 3 143 963 B1</text></patcit> discloses a three-part spacer mold, with a tibia spacer mold, a femur spacer mold and a third mold for producing a component that fills an intramedullary canal.

0008From the <patcit id="pcit0009" dnum="US10071511B2"><text>US 10 071 511 B2</text></patcit> molds for the production of tibia components of knee spacers are known. With these casting molds, tibia components of different heights can be manufactured. The casting mold consists of a lower part and an upper part, which form a cavity into which a polymethyl methacrylate bone cement paste can be pressed via a port. The height of the tibial component to be cast is defined by a locking mechanism with teeth, which defines the distance between the lower part and the upper part of the casting mold.

0009A similar concept is from the <patcit id="pcit0010" dnum="US9433506B2"><text>US 9 433 506 B2</text></patcit> known that claims a shape for a knee spacer. The casting mold contains a port that is present as a shaft in the intramedullary space after removal from the mold. The casting mold is filled through the port with the aid of a cement cartridge.

0010The object of the present invention is therefore to overcome the disadvantages of the prior art. In particular, the object of the invention is to develop an inexpensive device for producing a knee spacer component of a knee spacer by hardening bone cement paste and in the development of a simple and inexpensive process for producing a knee spacer component of a knee spacer by hardening bone cement paste, with which from medical staff in the operating room using bone cement paste, in particular from polymethyl methacrylate bone cement, one-piece knee spacer components, ie tibia components and femur components, can be produced. Tibial components and femoral components have a similar structure. They consist of a shaft and a head or a plateau.

0011The object of the invention is also to develop a device with which knee spacer components can be produced intraoperatively by medical staff using bone cement dough, in particular polymethyl methacrylate bone cement dough (PMMA bone cement dough). The basic structure of the device to be developed should in principle be the same for the tibia component and for the femur component of knee spacers. The device should therefore be suitable in a first variant for producing the tibia component and in a second variant for producing the femoral component of knee spacers. It should be possible to produce the knee spacer components of the knee spacer both with polymethyl methacrylate bone cement dough of normal viscosity and with high viscosity.

0012To completely fill a casting mold with a highly viscous bone cement paste, a high pressure is required. The device to be developed should therefore be designed in such a way that (polymethyl methacrylate) bone cement paste can be pressed into the device from a bone cement cartridge. When using bone cement dough that is not highly viscous, the bone cement dough must not flow out of the sprue after the casting mold has been completely filled. For this purpose, it is necessary to design the casting mold in such a way that even low-viscosity bone cement dough is reliably prevented from leaking out of the casting mold during the separation of the casting mold from the bone cement cartridge. This closure should be possible without the need for openings for complex valves in the wall of the casting mold. Openings in the wall of the casting mold can lead to leakage of the casting mold if the bone cement paste is pressed into the casting mold under high pressure. Furthermore, the sprue area of ​​the casting mold should be designed in such a way that on the one hand the casting mold can be easily filled with bone cement paste and on the other hand the sprue residues can easily be removed after the bone cement paste has hardened.

0013Furthermore, in one embodiment of the device, it should be possible to manufacture knee spacer components without the use of bone cement cartridges with (polymethyl methacrylate) bone cement dough which is mixed manually in suitable mixing bowls.

0014The objects of the invention are achieved by a device for producing a knee spacer component by hardening bone cement dough, the knee spacer component being provided in the medical field to temporarily replace part of a knee joint comprising an articulating surface of the knee joint, having the device a mold for molding the knee spacer component from bone cement dough; a valve seat which is connected to the casting mold, wherein the valve seat has a partially closed head side with at least one first passage, the at least one first passage opening into the casting mold; a valve body which is rotatably mounted against the valve seat and which has a sealing surface, the sealing surface being oriented in the direction of the partially closed head side of the valve seat, with at least one second passage being arranged in the sealing surface; wherein the valve seat and the valve body together form a valve, wherein the valve can be reversibly transferred into an open position and reversibly into a closed position by rotating the valve body against the valve seat, wherein in the open position of the valve the at least one first passage of the valve seat and the at least one second passage of the valve body are at least partially one above the other and provide a connection through the valve that is permeable to bone cement dough, with the at least one first passage of the valve seat in the closed position of the valve is covered by the sealing surface of the valve body, wherein the casting mold is closed in a liquid-tight manner in the closed position of the valve for bone cement dough. Liquid-tight means that the non-hardened, i.e. fluid, bone cement paste and preferably also a liquid monomer liquid as the starting component of the bone cement cannot flow out or penetrate through the connection at the connection.

0015For bone cement dough, covered means that the bone cement dough is prevented from flowing in the valve at least to such an extent that it cannot flow through the valve before it hardens. For this purpose, it is sufficient for bone cement dough with normal viscosity if the bone cement dough cannot flow in a straight line through the valve and the free line cross-sections are smaller than 1 mm. Bone cement doughs are viscous or highly viscous fluids, as indicated by the addition of "dough". The viscosity of a bone cement dough is at least 10 Pa s, which corresponds to the viscosity of liquid honey. In addition, the bone cement paste hardens within a few minutes, so that it is no longer possible to penetrate it. It can preferably be provided that the bone cement paste has a viscosity of at least 10 Pa s.

0016A bone cement dough or a fluid bone cement dough is to be understood as a mixed (that is, ready-to-use) bone cement dough that has a viscous consistency. The viscosity of a bone cement preferably corresponds to that of honey or has an even more viscous, higher viscosity when hot. The terms fluid bone cement and bone cement dough are used synonymously.

0017The casting mold is preferably hollow on the inside.

0018It can be provided that the sealing surface is closed except for the at least one second passage.

0019It can preferably also be provided that the casting mold has an interior space that simulates a negative shape of a tibial plateau or of condyles.

0020It can also be provided that the valve seat is connected to a casting mold wall of the casting mold in a liquid-impermeable manner.

0021Furthermore, it can be provided that the valve seat is designed as a disk, in particular as a flat disk, on one end face of a cavity delimited by the casting mold.

0022It can preferably also be provided that the valve seat and the valve body are in the form of a hollow cylinder.

0023It can also be provided that the casting mold is in two or more parts, with the parts of the casting mold preferably being slidable into one another. The casting mold is particularly preferably in two parts.

0024The mold should have a pressure of 10 N / cm² withstand in order to be able to use highly viscous bone cement.

0025In the present patent application, the direction designations "proximal", "distal" and "lateral" as well as the plane designations "sagittal plane", "frontal plane" and "transverse plane" are used in relation to the knee spacer, the knee spacer components and the casting mold, as this would be understood as the main anatomical direction or as a body plane in the state used in the patient. "Proximal" means towards the center of the body and "distal" means away from the center of the body.

0026The shaft is intended for connection to a bone (in the case of tibial components with the tibia and in the case of femoral components with the femur) and is preferably insertable for this purpose into a proximal or distal end of the prepared bone or into the bone canal .

0027It can preferably be provided that the device for producing a knee spacer component of a knee spacer is suitable for the application of at least one antibiotic and / or antimycotic active ingredient.

0028The knee spacer component is preferably manufactured in one piece from a biocompatible bone cement paste, such as polymethyl methacrylate (PMMA), with the PMMA particularly preferably containing at least one antibiotic and / or antimycotic that can be removed from the PMMA.

0029It can preferably be provided that the partially closed head side of the valve seat and the sealing surface of the valve body are disks or are disk-shaped.

0030It can preferably be provided that the valve seat delimits the casting mold.

0031The terms “open state” and “closed state” of the valve or of the valve body relative to the valve seat and the terms “open position” and “closed position” of the valve or of the valve body relative to the valve seat are used synonymously.

0032It can be provided that the valve seat is connected to the casting mold in a non-rotatable manner with respect to the casting mold, preferably the valve seat is firmly and / or rigidly connected to the casting mold or is made in one piece with the casting mold.

0033In this way, a seal or a liquid-tight connection between the valve seat and the casting mold can be achieved in a structurally simple and thus inexpensive manner.

0034Furthermore, it can be provided that the valve can be operated manually, preferably manually operated manually from outside the device, with the valve body particularly preferably being manually rotatable against the valve seat and the valve being rotated from the closed position to the open position and from the open position can be converted into the closed position.

0035As a result, the valve of the device can be conveniently operated from the outside in order to change a bone cement cartridge or to loosen it.

0036Furthermore, it can be provided that the at least one first passage of the valve seat is covered with the sealing surface of the valve body in the closed position of the valve, with the partially closed head side of the valve seat and the sealing surface of the valve body preferably being a maximum of 2 mm apart, particularly preferred are spaced apart from one another by a maximum of 1 mm, very particularly preferably spaced apart from one another by a maximum of 0.5 mm.

0037This can ensure that the bone cement dough (the fluid bone cement) filled into the casting mold cannot be pushed out of the casting mold through the valve again when the valve is closed. If the bone cement dough with these thicknesses or with these cross-sections hardens in the area of ​​the sprue, it can easily be broken off or cut through manually after the hardening of the spacer and does not have to be separated with a saw. Therefore, sprues with such thicknesses are harmless, as they do not significantly slow down the operation of the operating theater.

0038According to a preferred development of the present invention, it can be provided that the valve body is mounted rotatably about an axis of rotation against the valve seat, the axis of rotation running perpendicular to the sealing surface of the valve body or the axis of rotation running along an axis of rotational symmetry of the sealing surface of the valve body.

0039This ensures that the bone cement dough flowing through the valve can be cut off or twisted off from the valve body by the rotation. This enables a smooth cut surface and little effort when shearing. Furthermore, a rotation of the bone cement cartridge can also be used to shear off the bone cement paste. It is preferred that the axis of rotation runs along the axis of rotational symmetry of the sealing surface of the valve body. If the axis of rotation runs perpendicular to the sealing surface of the valve body, the valve can be constructed in the manner of a tap (for example for beer).

0040It can also be provided that the valve body has a connection for the liquid-tight connection of a bone cement cartridge or a handle of the device or is permanently connected to such a connection.

0041Furthermore, it can be provided that the valve body has the connection for the liquid-tight connection of a bone cement cartridge or is permanently connected to such a connection.

0042As a result, the valve body can be operated with the aid of a connected bone cement cartridge or operated with the handle.

0043It can be provided that the device has an adapter element which is or can be connected to a bone cement cartridge, the adapter element being detachably and positively connected or connectable to the connector so that an interior of a bone cement cartridge is permeable to the bone cement dough via the adapter element at least one second passage is connected or connectable in the valve body.

0044This ensures that the bone cement dough can be poured from the bone cement cartridge into the casting mold through the valve in its open position without any problems.

0045Furthermore, it can be provided that the connection for the liquid-tight connection of a bone cement cartridge or a handle piece comprises an internal thread in the valve body or an external thread on the valve body, wherein an adapter element of the bone cement cartridge or on the bone cement cartridge preferably has a mating thread matching the internal thread or the external thread or the handle of the device has a mating thread matching the internal thread or the external thread.

0046On the one hand, this enables a stable and liquid-tight connection to be established at the connection and, on the other hand, the rotation during the screwing movement can be used to turn the valve body against the valve seat at the beginning or after the end of the screwing movement and thus the valve from the open to the closed state to transfer or to transfer the valve from the closed to the open state.

0047By using suitable threads, an additional safety function of the device can be achieved in that a bone cement cartridge or the handle can only be loosened when the valve is closed and the valve can only be opened when the bone cement cartridge or handle is connected.

0048It can be provided that the internal thread in the valve body or the external thread on the valve body is a right-hand thread and the valve can be transferred from the closed to the open position by turning the valve body in the same direction and the valve can be transferred from the open to the open position by turning the valve body in the opposite direction closed position is transferable or the internal thread in the valve body or the external thread on the valve body is a left-hand thread and the valve can be transferred from the closed to the open position by turning the valve body in the same direction and the valve can be transferred from the open to the closed position by turning the valve body in the opposite direction or the internal thread of the valve seat and the internal thread and the external thread of the valve body are all left-hand threads or all right-hand threads, with an external thread of an adapter element or an external thread of the handle for the liquid-tight connection of a bone cement cartridge to the connection preferably also having the same direction of rotation.

0049These measures also aim to ensure that the valve closes automatically when the bone cement cartridge or the handle is unscrewed and the valve is automatically opened when the bone cement cartridge or the handle is screwed in.

0050It can also be provided that the valve body is mounted rotatably about an axis of rotation against the valve seat, the axis of rotation being oriented in the direction of the at least one first passage.

0051It can also be provided that the valve body can be rotated by an angle of a maximum of 280 ° against the valve seat, preferably by a maximum of 180 °, particularly preferably by a maximum of 100 ° against the valve seat, very particularly preferably by up to 90 ° against rotates the valve seat.

0052Preferably, two passages each can be arranged in the valve seat and in the valve body, two passages preferably being arranged offset by 180 ° around the center point of disks of the valve seat and the valve body, the disks being the partially closed head side of the valve seat and the sealing surface of the valve body form.

0053Furthermore, it can be provided that the device has a bone cement cartridge for mixing bone cement starting components and for discharging mixed bone cement dough out of the bone cement cartridge, preferably a bone cement cartridge for mixing polymethyl methacrylate bone cement starting components and for discharging mixed polymethyl methacrylate dough from the bone cement acrylate dough Has bone cement cartridge out, wherein the bone cement cartridge particularly preferably contains the bone cement starting components for the production of the bone cement dough in regions which are separate from one another.

0054This further completes the device, since the device can then also be used to provide the bone cement dough that is filled into the casting mold for shaping the knee spacer component of the knee spacer.

0055As an alternative to the bone cement cartridge, it can also be provided that the device has a monomer liquid container containing monomer liquid, a bone cement powder (preferably a packaged bone cement powder) and a mixing cup for the manual production and mixing of a bone cement dough from the monomer liquid and the bone cement powder, the device particularly preferably also having a mixing spatula having.

0056It can also be provided that the device has a handle that can be connected to the valve body and with which the valve body can be rotated against the valve seat, the handle preferably having a cavity for receiving bone cement dough, which is connected to the at least one second passage in a liquid-permeable manner is.

0057This allows the valve to be manually transferred from the closed to the open state with the aid of the handle.

0058It can preferably also be provided that the sum of all free openings of the at least one first passage in the closed head side is at most as large as the closed surface of the head side and that the sum of all free openings of the at least one second passage in the sealing surface is at most as large like the closed surface of the sealing surface.

0059This ensures that the valve can be closed in a stable manner that is impermeable to the bone cement paste by rotating the valve body against the valve seat.

0060It can also be provided that the valve seat has an internal thread on the inside and the valve body has a matching external thread on the outside, so that the valve body can be screwed into the valve seat.

0061This measure enables a high sealing effect to be achieved at the connection between the valve body and the valve seat. In addition, the valve can be assembled easily and inexpensively.

0062It can also be provided that the casting mold has a trough-shaped shape with a cavity and a stamp, the stamp being insertable or inserted into the cavity of the trough-shaped form and the stamp being axially displaceable in the cavity, and preferably the trough-shaped form having a cavity floor having, wherein the cavity floor forms the contour of one or more articulating sliding surfaces of the knee spacer component.

0063As a result, the knee spacer component can be shaped by pressing the bone cement paste in the casting mold with the aid of the punch. In addition, this opens up the possibility of setting the height of the knee spacer component in a variable manner.

0064It can advantageously be provided that the underside of the stamp is concave. This allows air to escape from the casting mold in the direction of a gap between the punch and the mold.

0065It can be provided that the valve seat is arranged in the punch, preferably at the end of a part of the punch that forms a shaft of the knee spacer component.

0066This allows excess bone cement paste to be pressed out of the casting mold when the stamp is pressed in by the stamp. This allows the height of the knee spacer component to be adjusted.

0067A shaft or a shaft shape is not necessary. The knee spacer component can also be designed without a shaft. The valve or sprue or casting can be arranged directly on the plane on one side of the tibia platform.

0068It can preferably also be provided that the at least one first passage in the partially closed head side has the same size and shape as the at least one second passage in the sealing surface.

0069It can also preferably be provided that the at least one first leadthrough in the partially closed head side are two first leadthroughs and the at least one second leadthrough in the sealing surface are two second leadthroughs, The two first passages are preferably arranged in oppositely arranged circular segment quarters with respect to the axis of rotation of the valve body in the valve seat and the two second passages are arranged in oppositely arranged circular segment quarters with respect to the rotational axis of the valve body in the sealing surface.

0070These two measures can provide a sufficient flow cross section for the viscous bone cement paste and one-sided loads on the valve can be avoided, which could otherwise lead to a leak in the valve.

0071The present invention also proposes that a collar be arranged on the sealing surface of the valve body, which is supported on an edge of the valve seat, or a collar is arranged on the partially closed head side of the valve seat, which is supported on an edge of the valve body.

0072In this way, stable guidance of the valve body on the valve seat can be achieved. Furthermore, the position of the at least one second passage for a given thread length of the valve body with respect to the at least one first passage can thereby be defined exactly.

0073Furthermore, it can be provided that a handle is fastened or can be fastened to the valve body, which has at least one radial extension with respect to the axis of rotation of the valve body, wherein the handle is preferably fastened or can be fastened to a side of the valve body opposite the sealing surface, with each other being particularly preferred the valve body can be rotated a maximum of 90 ° against the valve seat.

0074This means that the valve can easily be operated manually from the outside. With this handle, the valve body can be rotated from the open position to the closed position of the valve.

0075Furthermore, it can be provided that the valve body and the valve seat are made of plastic, in particular made of thermoplastic plastic, the valve seat preferably being made in one piece with the casting mold.

0076As a result, the valve and thus the device can be manufactured inexpensively and as a hygienic disposable product.

0077It can preferably also be provided that a locking element is arranged on the sealing surface of the valve body and a counter-locking element is arranged on the head side of the valve seat, wherein the locking element can be brought into engagement with the counter-locking element, wherein the locking element is positioned on the valve body so that it can rotate or turning the valve body out of the valve seat is limited to a maximum angle of 90 °, when the valve body is maximally inserted or screwed into the valve seat.

0078This ensures that the valve body is not rotated more than 90 ° against the valve seat when it is engaged. This can prevent the valve body from being rotated too far out of the valve seat and thereby creating an excessively large gap between the valve body and the valve seat and the valve from becoming permeable to the bone cement paste even in a closed position.

0079Furthermore, it can be provided that the casting mold is in two parts or in several parts, with a gap being present between at least two of the parts of the assembled casting mold through which air or gas can escape from the interior of the casting mold.

0080This prevents air pockets from remaining in the casting mold, which could impair the surface of the knee spacer component made from the bone cement dough.

0081It can also be provided that the device has a collecting container, the valve being connected or connectable to the collecting container on the side facing away from the casting mold for receiving excess bone cement dough emerging from the casting mold through the valve in the open position, or the valve being integrally connected with the collecting container is carried out.

0082This can prevent escaping bone cement paste from soiling and contaminating the operating room.

0083The objects on which the present invention is based are also achieved by a method for producing a knee spacer component for the temporary replacement of part of a knee joint comprising an articulating surface of the knee joint, the method being carried out with a device according to the invention, the method having the following chronological steps:<ol id="ol0001" compact="compact"><li>A) fluid-tight connection of a bone cement cartridge to the device;</li><li>B) pressing bone cement dough from the bone cement cartridge through the valve in the open position into the casting mold;</li><li>C) rotating the valve body against the valve seat and thereby transferring the valve into the closed position and shearing off the bone cement paste at the at least one first passage in the partially closed head side of the valve seat by rotating the valve body against the valve seat;</li><li>D) releasing the bone cement cartridge from the casting mold;</li><li>E) hardening of the bone cement paste in the casting mold; and</li><li>F) Removing the so shaped and cured knee spacer component from the casting mold.</li></ol>

0084The knee spacer is intended for medical applications. The method according to the invention does not include the implantation in a patient, but only the shaping of the knee spacer. After step F), the knee spacer can be deburred, smoothed, ground, cleaned, polished and / or roughened in areas.

0085To remove the molded and cured knee spacer from the casting mold in step F), the casting mold can be opened after step E).

0086According to the invention, it can be provided that the casting mold has a trough-shaped shape and a stamp. As a result, the knee spacer component can be shaped by pressure from the punch in order to obtain a sliding surface that is as smooth as possible and free of imperfections.

0087It can preferably be provided that the punch is pressed into the trough-shaped form in order to form the knee spacer component. For this purpose, it can particularly preferably be provided that the stamp is pressed into the trough-shaped form after step B) and particularly preferably before step C). In this way, part of the bone cement paste can be pressed out of the casting mold again through the valve.

0088It can be provided that the following intermediate steps take place after step D) and before step E):<ul id="ul0001" list-style="none" compact="compact"><li>D2) fluid-tight connection of a new bone cement cartridge to the device, bone cement dough or starting components for the production of the bone cement dough being or being contained in the new bone cement cartridge;</li><li>D3) rotating the valve body against the valve seat and thereby transferring the valve into the open position;</li><li>D4) pressing the bone cement paste from the new bone cement cartridge through the valve in the open position into the casting mold;</li><li>D5) rotating the valve body against the valve seat and thereby transferring the valve into the closed position and shearing off the bone cement paste at the at least one first passage in the partially closed head side of the valve seat by rotating the valve body against the valve seat; and</li><li>D6) releasing the new bone cement cartridge from the casting mold;</li></ul>steps D2) to D6) are preferably repeated once or several times with new bone cement cartridges each containing bone cement dough or its starting components until the casting mold is filled with bone cement dough completely or as required.

0089In this way, a casting mold with a large volume can be filled with several bone cement cartridges containing small volumes of the bone cement dough. This is advantageous, for example, for the production of large-volume knee spacers.

0090Furthermore, it can be provided that for the liquid-tight connection of the bone cement cartridge and / or the new bone cement cartridge, this is connected to a connection on the valve body of the device, wherein the bone cement cartridge or the new bone cement cartridge is screwed or screwed into the connection and, in order to detach the bone cement cartridge and / or the new bone cement cartridge from the connection, the bone cement cartridge or the new bone cement cartridge is screwed or unscrewed from the connection, and / or In addition to the screwing, the bone cement cartridge can be connected to the valve body with a bayonet lock, for example.

0091By screwing or screwing the bone cement cartridge into the valve body, a liquid-tight connection can be provided between the valve body and the bone cement cartridge. In addition, a rotation of the valve body against the valve seat can also take place or be induced by the rotation.

0092It can also be provided that the bone cement dough is pressed in from the bone cement cartridge or the new bone cement cartridge by pressing a piston into an interior space of the bone cement cartridge.

0093As a result, the bone cement dough can be pressed into the casting mold in a simple manner from the bone cement cartridge through the opened valve.

0094It can also be provided that the valve body is rotated against the valve seat by screwing the valve body in the valve seat or by manually rotating the valve body against the valve seat, the manual rotation preferably being carried out by operating a handle that is connected to the valve body .

0095This allows the valve to be operated easily by the user.

0096Furthermore, it can be provided that the casting mold has a trough-shaped shape and a punch, the punch being pressed into the trough-shaped shape before step E) and the knee spacer component being formed from the bone cement dough in the casting mold, whereby, when the punch is pressed into the trough-shaped mold, part of the bone cement dough is pressed out of the casting mold through the valve in the open position, and particularly preferably the part of the bone cement dough is pressed into a collecting container which is connected to the at least one second passage of the valve is.

0097This allows a knee spacer component with a variable height to be formed. In addition, the shaping inner surface of the casting mold can also be completely wetted with bone cement dough by pressing the punch in order to obtain a complete knee spacer component without any defects.

0098It should be noted here that the valve no longer has to be the same valve through which the bone cement paste was poured into the casting mold. When removing the bone cement cartridge, the valve body can also be removed and a handle piece with a new valve body can be inserted into the valve seat, so that the valve seat on the casting mold and the valve body of the handle piece form a new valve, but which is similar to the valve that from the Valve seat of the casting mold and the valve body for connecting the bone cement cartridge is constructed.

0099The objects on which the present invention is based are also achieved by a method for producing a knee spacer component for the temporary replacement of part of a knee joint comprising an articulating surface of the knee joint, the method being carried out with a device according to the invention, the method having the following chronological steps:<ol id="ol0002" compact="compact"><li>A) making a bone cement paste;</li><li>B) pouring a mixed bone cement paste into the casting mold;</li><li>C) compressing the casting mold and thereby pushing a portion of the bone cement paste out of the casting mold through the valve in the open position;</li><li>D) rotating the valve body against the valve seat and thereby transferring the valve into the closed position and shearing off the bone cement paste at the at least one first passage in the partially closed head side of the valve seat by rotating the valve body against the valve seat;</li><li>E) hardening of the bone cement paste in the casting mold; and</li><li>F) Removing the so shaped and cured knee spacer component from the casting mold.</li></ol>

0100The knee spacer is intended for medical applications. The method according to the invention does not include the implantation in a patient, but only the shaping of the knee spacer. After step F), the knee spacer can be deburred, smoothed, ground, cleaned, polished and / or roughened in areas.

0101It can be provided that a step B1) takes place between steps B) and C): B1) closing the casting mold except for the valve.

0102This ensures that the bone cement paste can only emerge from the casting mold through the valve.

0103Furthermore, it can be provided that the casting mold has a trough-shaped shape and a punch, the punch being pressed into the trough-shaped shape in step C) and thereby the knee spacer component being formed from the bone cement dough in the casting mold, preferably when the punch is pressed in into the trough-shaped mold part of the bone cement paste is pressed out of the casting mold through the valve in the open position.

0104This allows a knee spacer component with a variable height to be formed. In addition, the shaping inner surface of the casting mold can also be completely wetted with bone cement dough by pressing the punch in order to obtain a complete knee spacer component without any defects.

0105It can also be provided that before step B) the bone cement dough in the bone cement cartridge is mixed from a monomer liquid and from a cement powder, preferably before step D3), preferably before step D2), the bone cement dough in the new bone cement cartridge from a monomer liquid and from mixed with a cement powder.

0106This means that a freshly mixed bone cement dough can be used to produce the knee spacer. PMMA bone cement dough, in particular, is difficult or impossible to store in a mixed state for periods of more than a few minutes. In addition, pharmaceutical active ingredients suitable for treatment, such as antibiotics and antimycotics, can also be added to the bone cement dough shortly before the production of the knee spacer.

0107Furthermore, it can be provided that the valve body is rotated against the valve seat by screwing the valve body in the valve seat or by manually rotating the valve body against the valve seat, the manual rotation preferably being carried out by operating a handle on the valve body.

0108This allows the device to be operated in a simple manner.

0109The invention is based on the surprising finding that a valve body rotatable in a valve seat makes it possible to provide a device with a casting mold in which the sprue or casting with the valve body can be sheared off or largely sheared off and at the same time the casting mold can be closed or closed in this way to constrict the remaining channels at least so far that the bone cement dough can be kept under pressure in the casting mold, to press against the inside of the casting mold, at the same time preventing bone cement paste from being pushed out of the casting mold through the opening again or further. The device also makes it possible to fill the casting mold with the contents of several bone cement cartridges one after the other without the bone cement paste being able to flow out of the casting mold again through the opening. This makes it possible to produce knee spacers or knee spacer components with a large volume even with bone cement cartridges which provide only small volumes of the bone cement. A stamping of the knee spacer component can also be used to adjust the height of the knee spacer component and to press the bone cement dough against the shaping surfaces in the casting mold, with excess bone cement dough being pushed out of the casting mold through the open valve, the resulting Cast with the valve body can be sheared or largely sheared off before the bone cement paste hardens.

0110Bone cement dough, in particular bone cement dough that is not highly viscous, cannot flow out of the casting mold through the closure or the closed valve. This prevents the formation of defects in the knee spacer or in the knee spacer components as a result of the leakage of bone cement paste. Furthermore, the measures according to the invention separate the remainder of the bone cement paste (sprue) still in the bone cement cartridge and / or the bone cement paste (cast) pressed out of the casting mold from the bone cement paste in the casting mold. After the hardening of the bone cement paste has ended, it is therefore no longer necessary to separate the sprue or the cast mechanically, for example by sawing. Any remaining thin connections can easily be broken off or cut off. This reduces the amount of work and time required for the OR staff.

0111The sprue or the casting of the knee spacer component is formed by the opening with the valve seat and the valve body. By rotating the valve body with respect to the valve seat from the open position to the closed position of the valve, the casting mold is closed so as to be impermeable to bone cement paste. This means that the sprue / casting formed from the valve seat and the valve body, or the parts giving shape to the casting / casting, have a valve function at the same time. Complex additional valves are not necessary.

0112The manual rotation of the valve body against the valve seat can take place by means of a handle on the valve body. The rotation can advantageously also take place in that when the bone cement cartridge is unscrewed, the valve body is also rotated by the bone cement cartridge. In this case, however, it is necessary for a stop to limit the rotary movement of the valve body with respect to the valve seat so that the closure can take place safely and so that the valve body cannot be completely unscrewed from the valve seat.

0113In order to fill the casting mold, a counter pressure should be applied by the user. The casting mold can be filled with bone cement dough until the desired height of the knee spacer component is set in the casting mold. The punch of the casting mold can be pushed out of the trough-shaped shape of the casting mold, the more bone cement paste is filled into the casting mold. To do this, the user must maintain pressure on the casting mold via the stamp. Trapped air can escape from the gap between the punch and the trough-shaped mold. When the desired height of the knee spacer component in the mold is reached, the user can simply stop pressing more bone cement paste into the mold.

0114Alternatively, the bone cement dough can be filled into the casting mold in excess and the height is adjusted by compressing the casting mold after filling the bone cement dough until the desired height of the knee spacer component is reached in the casting mold. For this purpose, the stamp (for example with the handle) can be pressed deeply into the trough-shaped form until the desired height of the knee spacer component is set. Excess bone cement dough that flows out can flow away through the open valve. The excess bone cement paste is preferably taken up in a collecting container. The collecting container can be arranged in the handle with which the plunger and the valve are operated.

0115The height of the knee spacer component can be infinitely adjusted in this way. A detent or fastening means for adjusting the height on the casting mold are consequently not required for adjusting the height of the knee spacer component with the device according to the invention and the method according to the invention.

0116The parts of the casting mold also do not have to be attached to one another in a pressure-tight manner. No clips, screws or other fasteners are required to fasten the parts of the mold together or to take up pressure. As a result, these parts cannot get lost in the operating room and therefore cannot disrupt the course of an operation.

0117According to the invention, it is preferred that an internal thread or parts of an internal thread are arranged on the inside of a hollow cylinder-shaped valve body, the internal thread being reversibly connectable by screwing to the external thread of a cartridge head of a bone cement cartridge. With this device, knee spacer components can be produced in such a way that first a polymethyl methacrylate bone cement dough is made from cement powder and monomer liquid in a bone cement cartridge by mixing, that in a second step the bone cement cartridge is screwed into the valve body, the valve or the valve body is turned to the open position, that in a third step a die of the casting mold with the valve seat, the valve body and with the bone cement cartridge is pushed into a trough-shaped mold of the casting mold until the desired height above the bottom of the trough-shaped mold is reached, that in a fourth step the polymethyl methacrylate bone cement dough from the bone cement cartridge is pressed into the cavity of the casting mold under the punch with a discharge device until the desired fill level is reached under the punch, the air from the cavity of the casting mold via a space between the trough-shaped mold and the stamp escapes that in a fifth step the bone cement cartridge is screwed out of the valve body, the valve or the valve body being rotated into the closed position opposite the valve seat, whereby the polymethyl methacrylate bone cement paste in the cavity of the casting mold is separated from excess polymethyl methacrylate bone cement paste in the valve body, so that in a sixth step after the polymethyl methacrylate bone cement paste has hardened, the stamp is removed the trough-shaped form is pulled out, wherein the knee spacer component is detached from the die, and in a seventh step the knee spacer component is removed from the casting mold or the trough-shaped form of the casting mold.

0118It saves time and labor that the knee spacer component does not contain a cast or cast made of excess polymethyl methacrylate bone cement that has to be separated mechanically.

0119In a second embodiment variant, the valve body is designed as a hollow cylinder, on whose narrow side opposite the sealing surface a handle is arranged. The device is handled in such a way that, in a first step, polymethyl methacrylate bone cement powder is mixed with monomer liquid in a mixing bowl or in a bone cement cartridge to form a homogeneous polymethyl methacrylate bone cement paste, so that in a second step, an excess of bone cement paste compared to the volume the knee spacer component to be produced by casting, Injection or with a spatula is introduced into a trough-shaped form of the casting mold that, in a third step, a plunger of the casting mold with the valve seat and the valve body is inserted into the cavity of the casting mold, the valve or the valve body opposite the valve seat by turning the handle is rotated into the open position so that in a fourth step the punch is pressed with the handle in the direction of the bottom of the trough-shaped mold, until the desired height of the bone cement dough is reached in the casting mold, the excess bone cement dough passing through the valve seat and the valve body (or through the at least one first passage in the valve seat and through the at least one second passage in the valve body) that in a fifth step the The handle on the valve body is rotated that the valve or the valve body is moved into the closed position opposite the valve seat, whereby the excess polymethyl methacrylate bone cement paste in the valve body is separated from the polymethyl methacrylate bone cement paste in the cavity of the casting mold, that in a seventh step the polymethyl methacrylate bone cement paste hardens in the casting mold in an eighth step the stamp is pulled out of the trough-shaped form, wherein the punch separates from the cured knee spacer component and that in a ninth step the knee spacer component is removed from the casting mold or the trough-shaped form of the casting mold.

0120It saves time and work that the knee spacer component does not have a cast of excess polymethyl methacrylate bone cement that has to be separated in a mechanically complex manner. It is also advantageous if the underside of the plunger is concave so that the air is guided in the direction of the valve seat and is discharged through the valve seat and the valve body from the cavity of the casting mold.

0121A knee spacer produced with the device or the knee spacer components can advantageously be used in the context of two-stage septic revisions in which there is an infection with two or more microbial germs and in particular with problematic germs.

0122An exemplary device according to the invention can be composed of<ul id="ul0002" list-style="none" compact="compact"><li>a) a trough-shaped form as part of the casting mold, the trough-shaped form having a cavity, the cavity floor having the contour of one or more articulating sliding surfaces,</li><li>b) a punch as part of the casting mold, which is axially displaceable in the cavity of the trough-shaped mold, wherein the punch contains the opening which connects the bottom of the punch facing the cavity bottom of the trough-shaped mold with the opposite top side of the punch in a liquid-permeable manner,</li><li>c) a dimensionally stable hollow cylinder-shaped valve seat,</li><li>c1) which is arranged in the opening of the ram so that it cannot rotate,</li><li>c2) wherein the valve seat is designed as a disk on its head side, in which the at least one first passage is arranged, which connects the underside of the stamp to the top of the stamp in a liquid-permeable manner, the area of ​​the at least one first passage only a maximum of 50 percent of the disc surface of the valve seat, and</li><li>c3) wherein the valve seat has an internal thread on the inside,</li><li>d) a dimensionally stable, hollow cylinder-shaped valve body,</li><li>d1) which has an external thread on the outside of the hollow cylinder which can be screwed to the internal thread of the valve seat,</li><li>d2) the valve body being designed as a disc on its sealing surface facing the cavity of the trough-shaped shape, which has at least one second passage, the area of ​​the at least one second passage only taking up a maximum of 50 percent of the disc surface of the valve body, and</li><li>d4) wherein the at least one second passage has approximately the same size and shape as the at least one first passage of the valve seat,</li><li>d5) the valve body being rotated into an open position when it is screwed into the valve seat, so that the at least one second passage lies above the at least one first passage and a fluid-permeable connection is established between the interior of the casting mold and the environment and rotated into a closed position can be so that the at least one second passage does not cover or cover the at least one first passage, and</li><li>e) that polymethyl methacrylate bone cement dough introduced into the cavity of the trough-shaped mold is delimited by the underside of the punch and that excess polymethyl methacrylate bone cement dough is arranged in the cavity of the valve body, whereby, by rotating the valve body into the closed position, the excess polymethyl methacrylate bone cement paste is separated or sheared off or largely sheared off from the polymethyl methacrylate bone cement paste in the cavity of the casting mold.</li></ul>

0123After the pressing of the bone cement paste into the cavity of the casting mold has ended, the valve body is manually rotated so that the at least one second passage of the valve body is no longer above the at least one first passage of the dimensionally stable valve seat. As a result, the cavity of the casting mold is closed in a liquid-impermeable manner. Even a bone cement paste that is not highly viscous cannot flow out of the casting mold as a result.

0124An exemplary method according to the invention for the production of knee spacers with the device according to the invention can comprise the following successive steps:<ul id="ul0003" list-style="none" compact="compact"><li>a) providing the casting mold and the trough-shaped shape of the casting mold,</li><li>b) Mixing the bone cement powder with the monomer liquid in a bone cement cartridge until a homogeneous bone cement dough has formed,</li><li>c) Liquid-permeable connection of the bone cement cartridge to the casting mold or to the valve on the casting mold by screwing the adapter element into an internal thread of the valve body, the valve body being rotated into the open position,</li><li>d) Pressing the bone cement paste from the bone cement cartridge into the casting mold with the aid of an extrusion device, the bone cement paste displacing the air in the cavity of the casting mold and preferably the displaced air escaping through a gap between the trough-shaped mold and the punch from the cavity of the casting mold into the environment ,</li><li>e) Unscrewing the bone cement cartridge from the valve body, the valve body being rotated from the open position into the closed position of the valve, whereby the at least one first passage and the at least one second passage no longer stand on top of each other, so that no bone cement paste from the cavity of the casting mold can escape through the valve into the environment,</li><li>f) Separating the bone cement cartridge from the casting mold</li><li>g) hardening of the bone cement paste in the casting mold,</li><li>h) opening the casting mold after the bone cement paste has hardened by removing the stamp from the trough-shaped mold and</li><li>i) Removal of the knee spacer component.</li></ul>

0125An alternative exemplary method according to the invention for the production of knee spacers with the device according to the invention can comprise the following successive steps:<ul id="ul0004" list-style="none" compact="compact"><li>a) providing the casting mold and the trough-shaped shape of the casting mold,</li><li>b) Mixing a bone cement powder with a monomer liquid until a bone cement dough has formed (for example in a mixing bowl or in a bone cement cartridge),</li><li>c) Filling the bone cement paste into the trough-shaped form,</li><li>d) if necessary, opening the valve by turning the valve body against the valve seat into the open position,</li><li>e) inserting a die of the casting mold with the valve in the open position into the cavity of the trough-shaped mold,</li><li>f) Pressing a die of the casting mold in the direction of the cavity bottom of the trough-shaped mold until the desired height of the knee spacer component is reached, while at the same time displacing the air and the excess polymethyl methacrylate bone cement paste through the valve seat and the valve body in the open position into a cavity of the Valve body,</li><li>g) After the desired filling level of the polymethyl methacrylate bone cement dough has been reached, manually turning the valve body against the valve seat into the closed position so that the excess polymethyl methacrylate bone cement dough is separated from the polymethyl methacrylate bone cement dough in the cavity of the casting mold,</li><li>h) hardening of the bone cement paste in the casting mold,</li><li>i) opening the casting mold after the bone cement paste has hardened by removing the stamp from the trough-shaped mold and</li><li>i) Removal of the knee spacer component.</li></ul>

0126In the following, further exemplary embodiments of the invention are explained on the basis of thirty-three schematically illustrated figures, without, however, restricting the invention. It shows:<ul id="ul0005" list-style="none"><li><figref idref="f0001">Figure 1</figref>: a schematic perspective cross-sectional view of an exemplary first device according to the invention for producing a tibial component with an open valve;</li><li><figref idref="f0002">Figure 2</figref>: a schematic external view of the parts of the first device according to the invention <figref idref="f0001">Figure 1</figref>;</li><li><figref idref="f0003">Figure 3</figref>: a schematic perspective external view of the first device according to the invention according to the <figref idref="f0001">Figures 1</figref> and <figref idref="f0002">2</figref> with inserted stamp;</li><li><figref idref="f0004">Figure 4</figref>: a schematic perspective external view of the first device according to the invention according to the <figref idref="f0001 f0002 f0003">Figures 1 to 3</figref> with inserted stamp;</li><li><figref idref="f0005">Figure 5</figref>: a schematic perspective cross-sectional view of the first device according to the invention with the valve closed;</li><li><figref idref="f0006">Figure 6</figref>: a schematic perspective cross-sectional view of the first device according to the invention with an open valve during the molding of the tibial component;</li><li><figref idref="f0007">Figure 7</figref>: a schematic perspective cross-sectional view of the first device according to the invention with an open valve during the shaping of the tibia component, the cutting plane opposite <figref idref="f0006">Figure 6</figref> is rotated by 90 °;</li><li><figref idref="f0008">Figure 8</figref>: a schematic cross-sectional view of the first device according to the invention with an open valve and bone cement cartridge connected to the casting mold;</li><li><figref idref="f0009">Figure 9</figref>: a schematic cross-sectional view of the first device according to the invention with a closed valve with a bone cement cartridge detached from the casting mold;</li><li><figref idref="f0010">Figure 10</figref>: a schematic cross-sectional view of the first device according to the invention with an open valve and a handle connected to the casting mold during the molding of a tibial component;</li><li><figref idref="f0011">Figure 11</figref>: a schematic perspective view of an exemplary second device according to the invention for producing a femoral component;</li><li><figref idref="f0012">Figure 12</figref>: a schematic perspective cross-sectional view through the parts of the second device according to the invention <figref idref="f0011">Figure 11</figref> with a femoral component manufactured therewith;</li><li><figref idref="f0013">Figure 13</figref>: the filling of bone cement paste into part of the casting mold of the second device according to the invention;</li><li><figref idref="f0014">Figure 14</figref>: a schematic perspective external view of the parts of the second device according to the invention before the shaping of the femoral component;</li><li><figref idref="f0015">Figure 15</figref>: a schematic perspective cross-sectional view of the closed second device according to the invention according to the <figref idref="f0011 f0012 f0013 f0014">Figures 11 to 14</figref> and the femoral component contained therein;</li><li><figref idref="f0016">Figure 16</figref>: a perspective view of a femoral component, which with a second device according to the invention according to the <figref idref="f0011 f0012 f0013 f0014 f0015">Figures 11 to 15</figref> was produced;</li><li><figref idref="f0017">Figure 17</figref>: a schematic perspective external view of an exemplary third device according to the invention for producing a tibia component;</li><li><figref idref="f0018">Figure 18</figref>: a schematic perspective cross-sectional view of the third device according to the invention with the valve closed;</li><li><figref idref="f0019">Figure 19</figref>: a schematic perspective cross-sectional view of the third device according to the invention with an open valve and an inserted punch;</li><li><figref idref="f0020">Figure 20</figref>: a schematic perspective cross-sectional view of the third device according to the invention according to the <figref idref="f0017 f0018 f0019">Figures 17 to 19</figref> during molding of a tibial component;</li><li><figref idref="f0021">Figure 21</figref>: a schematic perspective cross-sectional view of the third device according to the invention according to the <figref idref="f0017 f0018 f0019 f0020">Figures 17 to 20</figref> after molding the tibia component;</li><li><figref idref="f0022">Figure 22</figref>: a perspective view of a tibial component of bone cement residue, which is produced with a third device according to the invention according to FIGS <figref idref="f0017 f0018 f0019 f0020 f0021">Figures 17 to 21</figref> was made, along with a bone cement residue;</li><li><figref idref="f0023">Figure 23</figref>: a schematic perspective view of a valve for a device according to the invention in the open state;</li><li><figref idref="f0024">Figure 24</figref>: a schematic perspective partial cross-sectional view of the valve according to FIG <figref idref="f0023">Figure 23</figref> when open;</li><li><figref idref="f0025">Figure 25</figref>: a schematic perspective cross-sectional view through the valve according to FIG</li><li><figref idref="f0023">Figures 23</figref> and <figref idref="f0024">24</figref> when open;</li><li><figref idref="f0026">Figure 26</figref>: a schematic perspective view of the valve according to FIG <figref idref="f0023 f0024 f0025">Figures 23 to 25</figref> when closed;</li><li><figref idref="f0027">Figure 27</figref>: a schematic perspective partial cross-sectional view of the valve according to FIG</li><li><figref idref="f0023 f0024 f0025 f0026">Figures 23 to 26</figref> when closed;</li><li><figref idref="f0028">Figure 28</figref>: a schematic perspective cross-sectional view of the valve according to FIG</li><li><figref idref="f0023 f0024 f0025 f0026 f0027">Figures 23 to 27</figref> when closed;</li><li><figref idref="f0029">Figure 29</figref>: a schematic cross-sectional view of the valve according to FIGS <figref idref="f0022 f0023 f0024 f0025 f0026 f0027">Figures 22 to 27</figref> when closed;</li><li><figref idref="f0030">Figure 30</figref>: a schematic perspective external view of an exemplary fourth device according to the invention for producing a tibia component;</li><li><figref idref="f0031">Figure 31</figref>: a schematic perspective external view of the fourth device according to the invention with an inserted punch;</li><li><figref idref="f0032">Figure 32</figref>: a schematic perspective external view of the fourth device according to the invention with an inserted punch; and</li><li><figref idref="f0033">Figure 33</figref>: a schematic perspective cross-sectional view of the fourth device according to the invention according to the <figref idref="f0030 f0031 f0032">Figures 30 to 32</figref> after shaping the tibia component.</li></ul>

0127In the <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008 f0009 f0010">Figures 1 to 10</figref> Figures of a first embodiment of a device according to the invention for producing knee spacer components of a knee spacer and parts thereof are shown in different views.

0128The first device according to the invention is suitable and intended for producing a tibial component of a knee spacer. The device comprises a mold which is composed of two parts. The casting mold can have a trough-shaped mold 1 and a punch 2. The punch 2 can be inserted into the trough-shaped mold 1 and can be pushed into the trough-shaped mold 1 and preferably also pulled out again. The trough-shaped form 1 can be manufactured inexpensively from plastic film. The plastic film can have several layers. An opening for bone cement dough 50 to flow through can be formed on one side of the punch 2, which opening can be delimited by a cylindrical wall of the punch 2. A valve seat 3 can be arranged in this opening. The valve seat 3 can be firmly connected to the die 2 of the casting mold or even be made in one piece, as in the<figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008 f0009 f0010">Figures 1 to 10</figref> is shown.

0129The valve seat 3 can be designed as a hollow cylinder, which is closed on a head side 4 aligned in the direction of the opening in the punch 2 with the exception of two first passages 5. The two first passages 5 can have a quarter-circle shape and can preferably be rotated or offset from one another by 180 ° with respect to the cylinder axis of the valve seat 3. A valve body 6 which can be axially rotated relative to the valve seat 3 can be arranged in the interior of the valve seat 3. The valve body 6 can have a sealing surface 7 or surface oriented in the direction of the head side 4 of the valve seat 3. The valve body 6 can be constructed as a stepped hollow cylinder, the front part of which can be screwed or inserted into the valve seat 3.

0130Two second passages 8 can be arranged in the sealing surface 7. The two second passages 8 can be shaped like the first passages 5 in the shape of a quarter circle and can preferably be arranged rotated by 180 ° with respect to the cylinder axis of the valve body 6 with respect to one another. The valve seat 3 and the valve body 6 together form a valve of the device. An adapter element 9 for the liquid-tight connection of a bone cement cartridge 10 can be screwed into the valve body 6. The bone cement cartridge 10 and the adapter element 9 can be part of the device according to the invention. The valve body 6 can be formed on its open side, which faces away from the sealing surface 7, as a connection 11 for connecting the adapter element 9.

0131The bone cement cartridge 10 can have a discharge opening 12 on its front side for discharging the bone cement dough 50 from the bone cement cartridge 10. The discharge opening 12 of the bone cement cartridge 10 can be arranged in the front of a discharge tube 13 of the bone cement cartridge 10. The discharge opening 12 can also be arranged in the adapter element 9 and delimited by it. The adapter element 9 can close the bone cement cartridge 10 on its front side up to the discharge opening 12 and optionally up to a vacuum connection 44, wherein the discharge tube 13 can protrude through the adapter element 9.

0132The device may have a handle 14 which forms a handle 16 at one end (see FIG <figref idref="f0002">Figures 2</figref>, <figref idref="f0004">4</figref>, <figref idref="f0006">6</figref>, <figref idref="f0007">7</figref> and <figref idref="f0010">10</figref>). At the opposite end of the handle 14, a valve body 18 with an external thread 19 can be arranged. The valve body 18 of the handle 14 can be arranged in the valve seat 3 and axially rotatable relative to the valve seat 3 (see<figref idref="f0006">Figures 6</figref>, <figref idref="f0007">7</figref> and <figref idref="f0010">10</figref>). The valve body 18 of the handle 14 can have a sealing surface or surface oriented in the direction of the head side 4 of the valve seat 3. The valve body 18 can be screwed or inserted into the valve seat 3.

0133Two second passages 21 of the handle 14 can be arranged in the sealing surface. The two second passages 21 can be shaped like the first passages 5 in the shape of a quarter circle and can preferably be arranged rotated by 180 ° with respect to the cylinder axis of the valve body 18 of the handle 14. The valve seat 18 of the handle 14 and the valve body 6 together also form a valve of the device. The handle 14 can be designed in the inner hollow. The cavity in the interior of the handle 14 can be connected to the two second passages 21 of the handle 14. As a result, the cavity inside the handle can form a collecting container for receiving excess bone cement dough 50, the excess bone cement dough 50 being able to flow from the casting mold through the two second passages 21 into the collecting container when the valve formed by the valve body 18 and the valve seat 3 is in an open position, in which the two first passages 5 in the valve seat 3 for the bone cement dough 50 are connected to the two second passages 21 of the handle 14 in a liquid-permeable manner or are arranged one above the other.

0134The punch 2 can be pushed into the trough-shaped mold 1. By inserting the stamp 2 into the trough-shaped mold 1, the casting mold can be closed to the outside. A gap for venting the interior of the casting mold can be present between the trough-shaped mold 1 and the punch 2 when they are nested into one another (in the<figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008 f0009 f0010">Figures 1 to 10</figref> not to be seen). Air or gas can escape from the interior of the closed casting mold through the gap when a bone cement paste 50 is poured into the casting mold.

0135The valve seat 3 can have an internal thread 20 on its inside. The external thread 19 of the handle 14 fits the internal thread 20 of the valve seat 3, so that the valve body 18 of the handle 14 can be screwed into the valve seat 3.

0136On the front half of the valve body 6 facing the sealing surface 7, the valve body 6 can have an external thread 22 on its outside that matches the internal thread 20 of the valve seat 3. The valve body 6 can be screwed with its external thread 22 into the internal thread 20 of the valve seat 3.

0137By screwing the valve body 6 into the valve seat 3 up to the stop, the first leadthroughs 5 and the second leadthroughs 8 can be brought into overlap with one another. Likewise, by screwing the valve body 18 of the handle 14 into the valve seat 3 up to the stop, the first leadthroughs 5 and the second leadthroughs 21 can be brought into overlap with one another. The valve is then in the open state. In this open state, a bone cement dough 50 can flow through the first passages 5 and through the second passages 8 from the bone cement cartridge 10 into the casting mold, or a bone cement dough 50 in this open state can flow through the first passages 5 and through the second passages 21 of the handle 14 flow from the casting mold into the collecting container in the handle 14.

0138By a quarter turn (by 90 °) of the valve body 6 or the valve body 18 against the valve seat 3, i.e. by screwing the valve body 6 or the valve body 18 out of the valve seat 3, the first passages 5 and the second passages 8 or the second Bushings 21 are offset against each other, so that the sealing surface 7 of the valve body 6 covers the first passages 5 of the valve seat 3 and the closed areas of the head side 4 of the valve seat 3 covers the second passages 8 of the valve body 6 or the second passages 21 of the valve body 18. The valve is then in the closed state. Due to the small stroke of the valve body 6 or the valve body 18 against the valve seat 3 with a quarter turn, the gap between the valve body 6 or the valve body 18 and the valve seat 3 is so narrow (less than 1 mm wide) that a normal and first quite a highly viscous bone cement dough 50 cannot penetrate through the gap. This is particularly true because the bone cement dough 50 in the gap is deflected by 90 ° from its actual flow direction.

0139In the rear of the valve body 6, an internal thread 24 can be arranged in connection 11. The adapter element 9 has an external thread 26 that matches the internal thread 24 on its front side. The adapter element 9 can thus be screwed into the connection 11 of the valve body 6. In this way, a liquid-tight connection between the bone cement cartridge 10 and the valve body 6 and thus in the casting mold can be produced.

0140The internal thread 20 of the valve seat 3, the external thread 19 of the valve body 18 of the handle 14, the external thread 22 of the valve body 6, the internal thread 24 of the valve body 6 and the external thread 26 of the adapter element 9 can all have the same direction of rotation, that is, all of these Threads are right-hand thread or left-hand thread. As a result, the valve can be opened by screwing the adapter element 9 into the connection 11 and turning the adapter element 9 further in the same direction. At the same time, the valve body 6 also seals against the valve seat 3. The valve can also be opened by screwing the handle 14 into the valve seat 3. At the same time, the valve body 18 also seals against the valve seat 3.

0141The adapter element 9 can be or be connected to a counter-catch 30 on a cylindrical wall of the bone cement cartridge 10 via a latching means 28 on the adapter element 9. A circumferential seal 48 can be provided for sealing, which seals the cylindrical wall of the bone cement cartridge 10 against the adapter element 9.

0142The mold may have a bottom plate 32 for molding a sliding surface of a knee spacer component (not shown) formed with the mold. In the present case, this can be a tibial plateau. The base plate 32 can form the base or the bottom of the trough-shaped mold 1. The punch 2 can be pushed into the trough-shaped mold 1 in the direction of the base plate 32. As a result, a bone cement dough 50 filled into the casting mold can be pressed against the base plate 32 of the trough-shaped mold 1. Furthermore, the casting mold and in particular the punch 2 of the casting mold can have a shaped shaft part 34 for molding a shaft of a tibia component.

0143A handle 38 can be connected to the valve body 6. The valve body 6 can be rotated manually with the handle 38 in the valve seat 3.

0144A vacuum connection 44 can be arranged in the adapter element 9, with which an interior space of the bone cement cartridge 10, in which the bone cement dough 50 is mixed, can be evacuated. This allows the bone cement dough 50 to be mixed under vacuum.

0145A piston 46 for driving the bone cement dough 50 out of the bone cement cartridge 10 through the valve body 6 and the valve seat 3 into the casting mold 1 can be arranged in the cylindrical interior of the bone cement cartridge 10. For this purpose, the piston 46 can have a cylindrical shape on its outside and be sealed against the cylindrical interior space by means of two circumferential seals 54. By advancing the piston 46, the bone cement dough 50 can be pressed out of the discharge opening 12 of the bone cement cartridge 10 into or through the opened valve consisting of the valve body 6 and the valve seat 3.

0146A pore disk 52 can be arranged in the adapter element 9. The pore disk 52 is impermeable to the bone cement dough 50 and its starting components. The vacuum connection 44 can be covered by the pore disk 52. This prevents a bone cement powder from being able to penetrate into the vacuum connection 44 as the starting component of the bone cement paste 50.

0147The sequence of a method according to the invention can be based on <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008 f0009 f0010">Figures 1 to 10</figref> will be explained with reference to the first device according to the invention. A bone cement dough 50 can be mixed in the bone cement cartridge 10 under vacuum. The bone cement cartridge 10 with the adapter element 9 can then be screwed into the connection 11 of the valve body 6. When the adapter element 9 is screwed in, the valve can be moved into the open position by screwing the valve body 6 into the valve seat 3 as far as it will go. This situation is in the<figref idref="f0001">Figures 1</figref>, <figref idref="f0003">3</figref> and <figref idref="f0008">8</figref> shown.

0148Then, by advancing the piston 46, the bone cement dough 50 is pressed out of the bone cement cartridge 10 through the valve and through the first passages 5 and second passages 8, which are in congruence, into the casting mold. The punch 2 can be pressed out of the trough-shaped mold 1. In order to form the knee spacer component by pressing the bone cement dough 50 against the inner walls of the casting mold, the user should maintain pressure on the punch 2 via the bone cement cartridge 10 while pressing in the bone cement dough 50. By closing the valve by manually operating the handle 38 and thereby turning the valve body 6 a quarter turn against the valve seat 3, a new bone cement cartridge 10 can be attached in between if the volume of the bone cement dough 50 of a single bone cement cartridge 10 is not sufficient for the casting mold to be sufficient to fill. The bone cement dough 50 contained in the casting mold cannot flow out again because the first passages 5 and the second passages 8 are covered in the closed position of the valve and the gap between them is not sufficient to allow the viscous bone cement dough 50 to flow through.

0149At some point the casting mold will be sufficiently filled with the bone cement paste 50. Air or gas from the casting mold can escape from the casting mold through the gap between the trough-shaped mold 1 and the punch 2. When the desired height of the knee spacer component is reached by pushing the punch 2 just the right amount out of the trough-shaped mold, the valve can remain closed and the bone cement paste 50 can harden in the casting mold in order to produce the knee spacer component. By closing the valve with the handle 38, the bone cement dough 50 is sheared off or cut off. The bone cement cartridge 10 can be unscrewed and removed.

0150Any remaining thin connections tear or break off easily. This situation is in<figref idref="f0005">Figure 5</figref> and <figref idref="f0009">Figure 9</figref> shown.

0151If excess bone cement dough 50 has been filled into the casting mold or the height of the knee spacer component is too great, the handle 14 can be screwed into the internal thread 20 of the valve seat 3 in order to set the desired height of the knee spacer component to be produced. The valve body 18 also forms a new valve with the valve seat 3. By screwing in the handle 14 up to the stop, the valve is brought into the open position. This situation is in the <figref idref="f0006">Figures 6</figref> and <figref idref="f0007">7</figref> shown.

0152By reducing the height of the interior of the casting mold by pushing the punch 2 into the trough-shaped mold 1, part of the bone cement paste 50 is pressed out of the casting mold and through the two first passages 5 and the two second passages 21 into the collecting container of the handle 14 . This is in<figref idref="f0010">Figure 10</figref> shown. The handle 14 is now rotated a quarter turn (90 °) and thus rotated the two second openings 21 against the two first openings 5 ​​and thus the valve is closed. The bone cement dough 50 is sheared off or largely sheared off in the valve.

0153In this state, the bone cement dough 50 can be hardened in the casting mold. The tibial component thus formed is then removed from the casting mold. A casting caused by the valve seat 3 and the first passages 5 can be cut off and removed. The surface of the tibia component can be polished and / or coated, for example with antibiotics.

0154Instead of a casting mold for molding a tibia component, a casting mold can also easily be used for molding a femur component.

0155In the <figref idref="f0011 f0012 f0013 f0014 f0015">Figures 11 to 15</figref> Figures of a second exemplary embodiment of a device according to the invention for producing a knee spacer component 110 in the form of a femur component for a knee spacer and parts of the device are shown in different views. the<figref idref="f0016">Figure 16</figref> shows the knee spacer component 110, which was produced with such a second device according to the invention, as a result of a method according to the invention, the method steps of which are chronologically shown in FIG <figref idref="f0013 f0014 f0015 f0016">Figures 13 to 16</figref> are shown.

0156The second device according to the invention is suitable and intended for producing a femoral component of a knee spacer. The device comprises a mold which is composed of two parts. The casting mold can have a trough-shaped shape 61 and a punch 62. The punch 62 can be inserted into the trough-shaped form 61 and can be pushed into the trough-shaped form 61 and preferably also pulled out again. The trough-shaped form 61 can be manufactured inexpensively from plastic film. The plastic film can have several layers. An opening for bone cement dough 51 to flow through can be formed on one side of the punch 62, which opening can be delimited by a cylindrical wall of the punch 62. A valve seat 63 can be arranged in this opening. The valve seat 63 can be firmly connected to the die 62 of the casting mold or even be made in one piece, as in the <figref idref="f0011 f0012 f0013 f0014 f0015">Figures 11 to 15</figref> is shown.

0157The valve seat 63 can be designed as a hollow cylinder, which is closed on a head side 64 oriented in the direction of the opening in the punch 62 with the exception of two first passages 65. The two first passages 65 can have a quarter-circle shape and can preferably be rotated or offset from one another by 180 ° with respect to the cylinder axis of the valve seat 63.

0158In the interior of the valve seat 63, a valve body 78 which can be axially rotated relative to the valve seat 63 can be or will be arranged. The valve body 78 can have a sealing surface 67 or surface which is oriented in the direction of the head side 64 of the valve seat 63 and which can be delimited by a locking pin 82 for closing the two first passages 65.

0159Two second passages 68 can be arranged in the valve body 78. The two second passages 68 can be shaped like the first passages 65 in the shape of a quarter circle and can preferably be arranged rotated by 180 ° with respect to the cylinder axis of the valve body 78 with respect to one another. The valve seat 63 and the valve body 78 together form a valve of the device.

0160The device may have a handle 74 that forms a handle 76 at one end (see FIG <figref idref="f0011">Figures 11</figref>, <figref idref="f0012">12</figref>, <figref idref="f0014">14</figref> and <figref idref="f0015">15</figref>). At the opposite end of the handle 74, the valve body 78 can be arranged with an external thread 79. The valve body 78 can be arranged in the valve seat 63 and axially rotatable against the valve seat 63 by means of the handle 74 (see<figref idref="f0014">Figures 14</figref> and <figref idref="f0015">15</figref>). The valve body 78 can have the locking pin 82 which is aligned in the direction of the head side 64 of the valve seat 63 and which forms the sealing surface 67 of the valve body 78. The valve body 78 can be screwed or inserted into the valve seat 63.

0161The handle 74 can be implemented in the inner hollow. The cavity in the interior of the handle 74 can be connected to the two second passages 68 of the handle 74. As a result, the cavity in the interior of the handle can form a collecting container for receiving excess bone cement 117, the excess bone cement dough 51 being able to flow from the casting mold through the two second passages 68 into the collecting container when the valve formed by the valve body 78 and the valve seat 63 is in an open position, in which the two first passages 65 in the valve seat 63 for the bone cement paste 51 are connected to the two second passages 68 in a liquid-permeable manner or are arranged one above the other.

0162The punch 62 can be pushed into the trough-shaped mold 61. By inserting the punch 62 into the trough-shaped mold 61, the casting mold can be closed to the outside. A gap for venting the interior of the casting mold can be present between the trough-shaped mold 61 and the punch 62 in the nested state (in the<figref idref="f0011 f0012 f0013 f0014 f0015">Figures 11 to 15</figref> not to be seen). Air or gas can escape from the interior of the closed casting mold through the gap when a bone cement paste 51 is poured into the casting mold.

0163The valve seat 63 can have an internal thread 80 on its inside. The external thread 79 of the handle piece 74 fits the internal thread 80 of the valve seat 63, so that the valve body 78 can be screwed into the valve seat 63.

0164By screwing the valve body 78 into the valve seat 63 up to the stop, the first passages 65 and the second passages 68 can be brought into overlap with one another. The valve is then in the open state. In this open state, a bone cement dough 51 can flow through the first passages 65 and through the second passages 68 from the casting mold into the collecting container in the handle 74.

0165By a quarter turn (by 90 °) of the valve body 78 against the valve seat 63, i.e. by screwing the valve body 78 out of the valve seat 63, the first passages 65 and the second passages 68 can be offset from one another, so that the sealing surface 67 of the valve body 78 covers the first passages 65 of the valve seat 63 and the closed areas of the head side 64 of the valve seat 63 covers the second passages 68 of the valve body 78. The valve is then in the closed state. Due to the small stroke of the valve body 78 against the valve seat 63 with a quarter turn, the gap between the valve body 78 and the valve seat 63 is so narrow (less than 1 mm wide) that a normal and even more highly viscous bone cement paste 51 cannot penetrate the Gap can penetrate. This is particularly true because the bone cement dough 51 is deflected in the gap from its actual flow direction by 90 °.

0166The internal thread 80 of the valve seat 63 and the external thread 79 of the valve body 78 can all have the same direction of rotation, that is to say that all of these threads are right-hand threads or left-hand threads. As a result, the valve can be opened by screwing the handle 74 into the valve seat 63. At the same time, the valve body 78 seals against the valve seat 63.

0167The mold may have a bottom plate 92 for molding a sliding surface of a knee spacer component 110 formed with the mold. In the present case, this can be a sliding surface 112 of structures of the femoral component that simulate the condyles of a femur (see<figref idref="f0016">Figure 16</figref>). The knee spacer component 110 can also have a shaft 114 and a cast 116 on the shaft 114. The base plate 92 can form the base or the bottom of the trough-shaped form 61. The punch 62 can be pushed into the trough-shaped mold 61 in the direction of the base plate 92. As a result, a bone cement dough 51 filled into the casting mold can be pressed against the base plate 92 of the trough-shaped mold 61. Furthermore, the casting mold and in particular the die 62 of the casting mold can have a shaped shaft part 94 for shaping the shaft 114 of the knee spacer component 110.

0168The bone cement dough 51 can be placed in a mixing cup 70 (see FIG <figref idref="f0011">Figures 11</figref> and <figref idref="f0013">13</figref>) can be mixed. For this purpose, the device can have a monomer liquid container 72 containing monomer liquid and a bone cement powder container 73 containing bone cement powder. The bone cement dough 51 can be mixed in the mixing cup 70 from the bone cement powder and the monomer liquid. To mix the bone cement paste 51 in the mixing cup 70, the device can have a spatula 75 or some other mixing tool. The monomer liquid container 72 can be a glass ampoule. The mixing cup 70 can have a spout 77 for pouring out the bone cement paste 51. The mixed bone cement dough 51 can be filled from the mixing cup 70 via the spout 77 of the mixing cup 70 into the trough-shaped mold 61 (see FIG<figref idref="f0013">Figure 13</figref>).

0169Alternatively, a bone cement cartridge for producing and filling a bone cement dough into the trough-shaped mold 61 or into the casting mold analogous to the first exemplary embodiment according to FIGS <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008 f0009 f0010">Figures 1 to 10</figref> be applied.

0170The sequence of a method according to the invention is described below with reference to FIG <figref idref="f0013 f0014 f0015 f0016">Figures 13 to 16</figref> explained with reference to the second device according to the invention. A bone cement dough 51 can be mixed in the mixing cup 70. For this purpose, the bone cement powder from the bone cement powder container 73 and the monomer liquid from the monomer liquid container 72 are filled into the mixing cup 70 and mixed there with the spatula 75 or another aid until the bone cement paste 51 is obtained. The bone cement dough 51 mixed in this way is then filled from the mixing cup 70 via the spout 77 into the trough-shaped mold 61 (see FIG <figref idref="f0013">Figure 13</figref>).

0171To set the desired height of the knee spacer component 110 to be produced, the handle 74 can now be screwed into the internal thread 80 of the valve seat 63. The valve body 78 forms a valve with the valve seat 63. By screwing in the handle 74 up to the stop, the valve is brought into the open position. This situation is in<figref idref="f0014">Figure 14</figref> shown.

0172By reducing the height of the interior of the casting mold by pushing the punch 62 into the trough-shaped mold 61, part of the bone cement paste 51 is pressed out of the casting mold and through the two first passages 65 and the two second passages 68 into the collecting container of the handle 74 . This is in<figref idref="f0015">Figure 15</figref> shown. The handle 74 is now rotated a quarter turn (90 °) and thus rotated the two second openings 68 against the two first openings 65 and thus the valve is closed. The bone cement paste 51 is sheared off or largely sheared off in the valve. In this way, the excess bone cement 117 contained in the collecting container of the handle 74 can be removed from the knee spacer component 110 or the bone cement dough 51 forming the knee spacer component 110 in the casting mold.

0173In this state, the bone cement paste 51 can be hardened in the casting mold. The knee spacer component 110 formed in this way is then removed from the casting mold (see FIG<figref idref="f0016">Figure 16</figref>). A cast 116 caused by the valve seat 63 and the first passages 65 can be cut off and removed. The surface of the knee spacer component 110 can be polished and / or coated, for example with antibiotics.

0174Instead of a casting mold for molding a femoral component, a casting mold can also easily be used for molding a tibial component.

0175In the <figref idref="f0017 f0018 f0019 f0020 f0021">Figures 17 to 21</figref> Figures of a third embodiment of a device according to the invention for producing a knee spacer component 210 in the form of a tibia component for a knee spacer and parts of the device are shown in different views. the<figref idref="f0022">Figure 22</figref> shows the knee spacer component 210 and a removed excess bone cement 271, which was produced with such a third device according to the invention, as a result of a method according to the invention, the method steps of which are chronologically shown in FIG <figref idref="f0013 f0014 f0015 f0016">Figures 13 to 16</figref> are shown.

0176The third device according to the invention is suitable and intended for producing a tibial component of a knee spacer. The device comprises a mold which is composed of two parts. The casting mold can have a trough-shaped mold 161 and a punch 162. The punch 162 can be inserted into the trough-shaped form 161 and can be pushed into the trough-shaped form 161 and preferably also pulled out again. The trough-shaped form 161 can be manufactured inexpensively from plastic film. The plastic film can have several layers. An opening for bone cement dough to flow through (not shown) can be formed on one side of the punch 162, which opening can be delimited by a cylindrical wall of the punch 162. A valve seat 163 can be arranged in this opening. The valve seat 163 can be firmly connected to the die 162 of the casting mold or even be made in one piece, as in FIG <figref idref="f0017 f0018 f0019 f0020 f0021">Figures 17 to 21</figref> is shown.

0177The valve seat 163 can be designed as a hollow cylinder, which is closed on a head side 164 oriented in the direction of the opening in the punch 162 except for two first passages 165. The two first passages 165 can have a quarter-circle shape and can preferably be rotated or offset from one another by 180 ° with respect to the cylinder axis of the valve seat 163.

0178In the interior of the valve seat 163, a valve body 178 which can be axially rotated relative to the valve seat 163 can be or will be arranged. The valve body 178 can have a sealing surface 167 or surface which is oriented in the direction of the head side 164 of the valve seat 163 and which can be suitable for closing the two first passages 165.

0179Two second passages 168 can be arranged in the valve body 178. The two second passages 168 can be shaped like the first passages 165 in the shape of a quarter circle and can preferably be arranged rotated by 180 ° with respect to the cylinder axis of the valve body 178. The valve seat 163 and the valve body 178 together form a valve of the device.

0180The device may have a handle 174 that forms a handle 176 at one end (see FIG <figref idref="f0017 f0018 f0019 f0020 f0021">Figures 17 to 21</figref>). At the opposite end of the handle 174, the valve body 178 can be arranged with an external thread 179. The valve body 178 can be arranged in the valve seat 163 and axially rotatable relative to the valve seat 163 by means of the handle 174 (see<figref idref="f0018 f0019 f0020 f0021">Figures 18 to 21</figref>). The valve body 178 can be screwed or inserted into the valve seat 163.

0181The handle 174 can be implemented in the inner hollow. The cavity in the interior of the handle 174 can be connected to the two second passages 168 of the handle 174. As a result, the cavity in the interior of the handle can form a collecting container for receiving excess bone cement 217, the excess bone cement paste from the casting mold being able to flow through the two second passages 168 into the collecting container when the valve formed by the valve body 178 and the valve seat 163 is in is in an open position, in which the two first passages 165 in the valve seat 163 for the bone cement dough are connected to the two second passages 168 in a liquid-permeable manner or are arranged one above the other.

0182The punch 162 can be pushed into the trough-shaped mold 161. By inserting the stamp 162 into the trough-shaped mold 161, the casting mold can be closed to the outside. A gap for venting the interior of the casting mold can be present between the trough-shaped mold 161 and the punch 162 in the nested state (in the<figref idref="f0017 f0018 f0019 f0020 f0021">Figures 17 to 21</figref> not to be seen). Air or gas can escape from the interior of the closed casting mold through the gap when a bone cement paste is poured into the casting mold.

0183The valve seat 163 can have an internal thread 180 on its inside. The external thread 179 of the handle 174 fits the internal thread 180 of the valve seat 163, so that the valve body 178 can be screwed into the valve seat 163.

0184By screwing the valve body 178 into the valve seat 163 up to the stop, the first leadthroughs 165 and the second leadthroughs 168 can be brought into overlap with one another. The valve is then in the open state. In this open state, a bone cement dough can flow through the first passages 165 and through the second passages 168 from the casting mold into the collecting container in the handle 174.

0185By a quarter turn (by 90 °) of the valve body 178 against the valve seat 163, i.e. by screwing the valve body 178 out of the valve seat 163, the first passages 165 and the second passages 168 can be offset from one another, so that the sealing surface 167 of the valve body 178 covers the first passages 165 of the valve seat 163 and the closed areas of the head side 164 of the valve seat 163 covers the second passages 168 of the valve body 178. The valve is then in the closed state. Due to the small stroke of the valve body 178 against the valve seat 163 with a quarter turn, the gap between the valve body 178 and the valve seat 163 is so narrow (less than 1 mm wide) that a normal and even more highly viscous bone cement paste cannot pass through the gap can penetrate. This is particularly true because the bone cement paste in the gap is deflected by 90 ° from its actual direction of flow.

0186The internal thread 180 of the valve seat 163 and the external thread 179 of the valve body 178 can all have the same direction of rotation, that is to say that all of these threads are right-hand threads or left-hand threads. As a result, the valve can be opened by screwing the handle 174 into the valve seat 163. At the same time, the valve body 178 seals against the valve seat 163.

0187The mold may have a bottom plate 192 for molding a sliding surface of a knee spacer component 210 formed with the mold. In the present case, this can be a sliding surface 212 of a tibial plateau of a tibial component (see<figref idref="f0022">Figure 22</figref>). The knee spacer component 210 can also have a shaft 214 and a cast 216 on the shaft 214. The base plate 192 can form the base or the bottom of the trough-shaped mold 161. The punch 162 can be pushed into the trough-shaped mold 161 in the direction of the base plate 192. As a result, a bone cement dough filled into the casting mold can be pressed against the base plate 192 of the trough-shaped mold 161. Furthermore, the casting mold and in particular the die 162 of the casting mold can have a shaped shaft part 194 for shaping the shaft 214 of the knee spacer component 210.

0188The sequence of a method according to the invention is described below with reference to FIG <figref idref="f0017 f0018 f0019 f0020 f0021 f0022">Figures 17 to 22</figref> explained with reference to the third device according to the invention. A bone cement dough is filled in the trough-shaped mold 161.

0189To set the desired height of the knee spacer component 210 to be produced, the handle 174 can now be screwed into the internal thread 180 of the valve seat 163. The valve body 178 forms a valve with the valve seat 163. This situation is in<figref idref="f0018">Figure 18</figref> shown. By screwing the handle 174 in as far as it will go, the valve is brought into the open position (see<figref idref="f0019">Figure 19</figref>).

0190By reducing the height of the interior of the casting mold by pushing the punch 162 into the trough-shaped mold 161, part of the bone cement paste is pressed out of the casting mold and through the two first passages 165 and the two second passages 168 into the collecting container of the handle 174. This is in<figref idref="f0020">Figure 20</figref> shown. The handle 174 is now rotated a quarter turn (90 °) and thus rotated the two second openings 168 against the two first openings 165 and thus the valve is closed. The bone cement paste in the valve is sheared off or largely sheared off. In this way, the excess bone cement 217 contained in the collecting container of the handle 174 can be removed from the knee spacer component 210 or the bone cement dough forming the knee spacer component 210 in the casting mold.

0191In this state, the bone cement paste can be hardened in the casting mold. The knee spacer component 210 thus formed is then removed from the casting mold (see FIG<figref idref="f0022">Figure 22</figref>). A cast 216 caused by the valve seat 163 and the first passages 165 can be cut off and removed. The surface of the knee spacer component 210 can be polished and / or coated, for example with antibiotics.

0192Instead of a casting mold for molding a tibia component, a casting mold can also easily be used for molding a femur component.

0193the <figref idref="f0023 f0024 f0025 f0026 f0027 f0028 f0029">Figures 23 to 29</figref> show a valve for a device according to the invention for producing a knee spacer in the open position (<figref idref="f0023 f0024 f0025">Figures 23 to 25</figref>) and in closed position (<figref idref="f0026 f0027 f0028 f0029">Figures 26 to 29</figref>). The valve corresponds to the valves of the first device according to the invention according to the<figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008 f0009 f0010">Figures 1 to 10</figref>, the second device according to the invention after the <figref idref="f0011 f0012 f0013 f0014 f0015">Figures 11 to 15</figref> and the third device according to the invention according to the <figref idref="f0017 f0018 f0019 f0020 f0021">Figures 17 to 21</figref>, but can also be used with other molds to produce other knee spacers and knee spacer components.

0194The valve has a valve seat 263 which can be arranged in a casting mold (not shown) or made in one piece with a casting mold (not shown). The valve seat 263 can, however, also be firmly connected to part of the casting mold in some other way or also be embodied in one piece with the casting mold or part of the casting mold.

0195The valve seat 263 can be designed as a hollow cylinder which is closed on a head side 264 except for two first passages 265. The two first passages 265 can have a quarter-circle shape and can preferably be arranged rotated by 180 ° with respect to the cylinder axis of the valve seat 263 with respect to one another. A valve body 266 which can be axially rotated relative to the valve seat 263 can be arranged in the interior of the valve seat 263. The valve body 266 can have a sealing surface 267 or surface oriented in the direction of the head side 264 of the valve seat 263. The valve body 266 can be constructed as a stepped hollow cylinder, the front part of which can be screwed or inserted into the valve seat 263.

0196Two second passages 268 can be arranged in the sealing surface 267. The two second passages 268 can be shaped like the first passages 265 in the shape of a quarter circle and can preferably be rotated or offset from one another by 180 ° with respect to the cylinder axis of the valve body 266. The valve seat 263 and the valve body 266 together form the valve of a device according to the invention. A handle (not shown) or an adapter element (not shown) for the fluid-tight connection of a bone cement cartridge (not shown) can be screwed into the valve body 266. The valve body 266 can be shaped on its open side, which faces away from the sealing surface 267, as a connection 271 for connecting the handle piece or an adapter element.

0197The valve seat 263 can have an internal thread 280 on its inside. On the front half of the valve body 266 facing the sealing surface 267, the valve body 266 can have, on its outside, an external thread 282 that matches the internal thread 280 of the valve seat 263. The valve body 266 can be screwed with its external thread 282 into the internal thread 280 of the valve seat 263.

0198By screwing the valve body 266 into the valve seat 263 up to the stop, the first passages 265 and the second passages 268 can be brought into overlap with one another. The valve is then in the open state. A bone cement dough can in this open state (see<figref idref="f0023 f0024 f0025">Figures 23 to 25</figref>) flow through the first feedthroughs 265 and through the second feedthroughs 268. By a quarter turn (by 90 °) of the valve body 266 against the valve seat 263, that is, by screwing the valve body 266 out of the valve seat 263, the first passages 265 and the second passages 268 can be offset from one another, so that the sealing surface 267 of the valve body 266 covers the first passages 265 of the valve seat 263 and the closed areas of the head side 264 of the valve seat 263 covers the second passages 268 of the valve body 266. The valve is then in the closed state (see<figref idref="f0026 f0027 f0028 f0029">Figures 26 to 29</figref>). Due to the small stroke of the valve body 266 against the valve seat 263 with a quarter turn, the gap 320 created between the valve body 266 and the valve seat 263 is so narrow (less than 1 mm wide) that a normal and even more highly viscous bone cement paste cannot penetrate the Can penetrate gap 320 (see<figref idref="f0029">Figure 29</figref>). This is particularly true because the bone cement dough in the gap 320 is deflected by 90 ° from its actual direction of flow.

0199In the rear of the valve body 266, an internal thread 284 can be arranged in connection 271. A handle (not shown) or an adapter element (not shown) can thus be screwed into the connection 271 of the valve body 266. The internal thread 280 of the valve seat 263, the external thread 282 of the valve body 266 and the internal thread 284 of the valve body 266 can all have the same direction of rotation, that is to say that all of these threads are right-hand threads or left-hand threads. As a result, the valve can be opened by screwing a handle or an adapter element into the connection 271 and turning the handle or the adapter element further in the same direction. At the same time, the valve body 266 also seals against the valve seat 263.

0200Furthermore, a handle 298 can be arranged on the valve body 266. The valve body 266 can be rotated with the handle 298 in the valve seat 263. As a result, the valve can be manually transferred from the outside from the open state to the closed state or from the closed state to the open state with the aid of the handle 298, even if a bone cement cartridge is connected to the connection 271.

0201In the <figref idref="f0030 f0031 f0032 f0033">Figures 30 to 33</figref> Figures of a fourth embodiment of a device according to the invention for producing a knee spacer component 410 in the form of a tibia component for a knee spacer and parts of the device are shown in different views. the<figref idref="f0033">Figure 33</figref> shows, inter alia, the knee spacer component 410, which was produced with such a fourth device according to the invention, as the result of a method according to the invention, the method steps of which are chronologically shown in FIG <figref idref="f0030 f0031 f0032 f0033">Figures 30 to 33</figref> are shown.

0202The fourth device according to the invention is suitable and intended for producing a tibial component of a knee spacer. The device comprises a mold which is composed of two parts. The casting mold can have a trough-shaped mold 361 and a punch 362. The punch 362 can be inserted into the trough-shaped form 361 and can be pushed into the trough-shaped form 361 and preferably also pulled out again. The trough-shaped form 361 can be manufactured inexpensively from plastic film. The plastic film can have several layers. On one side of the punch 362, an opening for the flow of bone cement paste (not shown) can be formed, which opening can be delimited by a cylindrical wall of the punch 362. A valve seat 363 can be arranged in this opening. The valve seat 363 can be firmly connected to the die 362 of the casting mold or can even be made in one piece, as is the case in FIG <figref idref="f0030 f0031 f0032 f0033">Figures 30 to 33</figref> is shown.

0203The valve seat 363 can be designed as a hollow cylinder, which is closed on a head side 364 aligned in the direction of the opening in the punch 362 with the exception of two first passages 365. The two first passages 365 can have a quarter-circle shape and can preferably be rotated or offset from one another by 180 ° with respect to the cylinder axis of the valve seat 363.

0204In the interior of the valve seat 363, a valve body 178 that is axially rotatable relative to the valve seat 363 can be or will be arranged. The valve body 178 can have a sealing surface 167 or surface which is oriented in the direction of the head side 364 of the valve seat 363 and which can be suitable for closing the two first passages 365.

0205Two second passages 168 can be arranged in the valve body 178. The two second passages 168 can be shaped like the first passages 365 in the shape of a quarter circle and can preferably be arranged rotated by 180 ° with respect to the cylinder axis of the valve body 178. The valve seat 363 and the valve body 178 together form a valve of the device.

0206The device may have a handle 174 that forms a handle 176 at one end (see FIG <figref idref="f0030 f0031 f0032 f0033">Figures 30 to 33</figref>). The handle 174 of the fourth embodiment according to the<figref idref="f0030 f0031 f0032 f0033">Figures 30 to 33</figref> is the same as the handle 174 of the third embodiment according to the <figref idref="f0017 f0018 f0019 f0020 f0021">Figures 17 to 21</figref> executed. The same reference numbers have therefore been used. At the opposite end of the handle 174, the valve body 178 can have an external thread 179. The valve body 178 can be or will be arranged in the valve seat 363 and axially rotatable relative to the valve seat 363 by means of the handle 174 (see FIG<figref idref="f0031">Figures 31</figref> and <figref idref="f0032">32</figref>). The valve body 178 can be screwed or plugged into the valve seat 363.

0207The handle 174 can be implemented in the inner hollow. The cavity in the interior of the handle 174 can be connected to the two second passages 168 of the handle 174. As a result, the cavity in the interior of the handle can form a collecting container for receiving excess bone cement, with the excess bone cement dough flowing out of the casting mold through the two second passages 168 into the collecting container when the valve formed by the valve body 178 and the valve seat 363 is in one is in the open position, in which the two first passages 365 in the valve seat 363 for the bone cement dough are connected to the two second passages 168 in a liquid-permeable manner or are arranged one above the other.

0208The punch 362 can be pushed into the trough-shaped mold 361. By inserting the stamp 362 into the trough-shaped mold 361, the casting mold can be closed to the outside. Between the trough-shaped mold 361 and the punch 362, when they are inserted one into the other, there can be a gap for venting the interior of the casting mold (in the<figref idref="f0030 f0031 f0032 f0033">Figures 30 to 33</figref> not to be seen). Air or gas can escape from the interior of the closed casting mold through the gap when a bone cement paste is poured into the casting mold.

0209The valve seat 363 can have an internal thread 380 on its inside. The external thread 179 of the handle 174 fits the internal thread 380 of the valve seat 363 so that the valve body 178 can be screwed into the valve seat 363.

0210By screwing the valve body 178 into the valve seat 363 up to the stop, the first passages 365 and the second passages 168 can be brought into overlap with one another. The valve is then in the open state. In this open state, a bone cement dough can flow through the first passages 365 and through the second passages 168 from the casting mold into the collecting container in the handle 174.

0211The first passages 365 and the second passages 168 can be offset from one another by a quarter turn (by 90 °) of the valve body 178 against the valve seat 363, i.e. by screwing the valve body 178 out of the valve seat 363, so that the sealing surface 167 of the valve body 178 covers the first passages 365 of the valve seat 363 and the closed areas of the head side 364 of the valve seat 363 covers the second passages 168 of the valve body 178. The valve is then in the closed state. Due to the small stroke of the valve body 178 against the valve seat 363 with a quarter turn, the gap created between the valve body 178 and the valve seat 363 is so narrow (less than 1 mm wide) that a normal and even more highly viscous bone cement paste cannot pass through the gap can penetrate. This is particularly true because the bone cement paste in the gap is deflected by 90 ° from its actual direction of flow.

0212The internal thread 380 of the valve seat 363 and the external thread 179 of the valve body 178 can all have the same direction of rotation, that is to say that all of these threads are right-hand threads or left-hand threads. As a result, the valve can be opened by screwing the handle 174 into the valve seat 363. At the same time, the valve body 178 seals against the valve seat 363.

0213The mold may have a bottom plate 392 for forming a sliding surface of a knee spacer component 410 formed with the mold. In the present case, this can be a sliding surface of a tibial plateau of a tibial component (see<figref idref="f0033">Figure 33</figref>). The knee spacer component 410 may include a cast 416. the knee spacer component 410 according to the fourth exemplary embodiment, in contrast to the other exemplary embodiments 1 to 3, does not have a shaft. The base plate 392 can form the base or the bottom of the trough-shaped form 361. The punch 362 can be pushed into the trough-shaped mold 361 in the direction of the base plate 392. As a result, a bone cement dough filled into the casting mold can be pressed against the base plate 392 of the trough-shaped mold 361.

0214The sequence of a method according to the invention runs analogously to the methods of exemplary embodiments two and three explained by way of example.

0215The bone cement dough can be placed in a mixing cup 70 (see <figref idref="f0030">Figure 30</figref>) can be mixed. For this purpose, the device can have a monomer liquid container 72 containing monomer liquid and a bone cement powder container 73 containing bone cement powder. The bone cement dough can be mixed in the mixing cup 70 from the bone cement powder and the monomer liquid. In order to mix the bone cement paste in the mixing cup 70, the device may have a spatula 75 or some other mixing tool. The monomer liquid container 72 can be a glass ampoule. The mixing cup 70 can have a spout 77 for pouring out the bone cement paste. The mixed bone cement dough can be filled from the mixing cup 70 via the spout 77 of the mixing cup 70 into the trough-shaped mold 361.

0216Alternatively, a bone cement cartridge can also be used for producing and filling a bone cement dough into the trough-shaped mold 361 or into the casting mold analogously to the first exemplary embodiment according to FIG <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008 f0009 f0010">Figures 1 to 10</figref> be applied.

0217Instead of a casting mold for molding a tibia component, a casting mold can also easily be used for molding a femur component.

0218The features of the invention disclosed in the preceding description and in the claims, figures and exemplary embodiments can be essential both individually and in any combination for the implementation of the invention in its various embodiments.

List of reference symbols

0219<dl id="dl0001" compact="compact"><dt>1, 61, 161, 361</dt><dd>Trough-shaped mold / casting mold</dd><dt>2, 62, 162, 362</dt><dd>Stamp / mold</dd><dt>3, 63, 163, 263, 363</dt><dd>Valve seat</dd><dt>4, 64, 164, 264, 364</dt><dd>Head side</dd><dt>5, 65, 165, 265, 365</dt><dd>execution</dd><dt>6, 266</dt><dd>Valve body</dd><dt>7, 67, 167, 267</dt><dd>Sealing surface</dd><dt>8, 68, 168, 268</dt><dd>execution</dd><dt>9</dt><dd>Adapter element</dd><dt>10</dt><dd>Bone cement cartridge</dd><dt>11, 271</dt><dd>connection</dd><dt>12</dt><dd>Discharge opening</dd><dt>13</dt><dd>Discharge pipe</dd><dt>14, 74, 174</dt><dd>Handle</dd><dt>15</dt><dd>mixer</dd><dt>16, 76, 176</dt><dd>handle</dd><dt>17</dt><dd>poetry</dd><dt>18, 78, 178</dt><dd>Valve body</dd><dt>19, 79, 179</dt><dd>External thread</dd><dt>20, 80, 180, 280, 380</dt><dd>inner thread</dd><dt>21</dt><dd>execution</dd><dt>22, 182, 282</dt><dd>External thread</dd><dt>24, 184, 284</dt><dd>inner thread</dd><dt>26</dt><dd>External thread</dd><dt>28</dt><dd>Locking means</dd><dt>30</dt><dd>Counter-locking</dd><dt>32, 92, 192, 392</dt><dd>Base plate for forming a sliding surface</dd><dt>34, 94, 194</dt><dd>Shank molding</dd><dt>38, 298</dt><dd>Handle</dd><dt>44</dt><dd>Vacuum connection</dd><dt>46</dt><dd>Pistons</dd><dt>48</dt><dd>poetry</dd><dt>50, 51</dt><dd>Bone cement dough</dd><dt>52</dt><dd>Pore ​​disk</dd><dt>54</dt><dd>poetry</dd><dt>70</dt><dd>Mixing cup</dd><dt>72</dt><dd>Monomer liquid container</dd><dt>73</dt><dd>Bone cement powder container</dd><dt>75</dt><dd>spatula</dd><dt>77</dt><dd>grommet</dd><dt>82</dt><dd>Locking pin</dd><dt>110</dt><dd>Knee Spacer Component / Femur Component</dd><dt>112,212</dt><dd>Sliding surface</dd><dt>114,214</dt><dd>shaft</dd><dt>116,216,416</dt><dd>Cast</dd><dt>117, 217</dt><dd>Excess bone cement</dd><dt>210, 410</dt><dd>Knee Spacer Component / Tibial Component</dd><dt>316</dt><dd>head Start</dd><dt>320</dt><dd>gap</dd></dl>