EP4079396B1 - Device for producing bone cement - Google Patents

Description

The invention relates to a device for providing a bone cement dough from two starting components, comprising a hollow cylindrical cartridge with an interior, wherein a bone cement powder is stored as the first starting component in a front part of the interior and a container containing a monomer liquid is stored as the second starting component in a rear part of the interior, wherein a discharge piston which is axially movable in the interior is arranged between the bone cement powder and the container and a delivery piston which is axially movable in the interior is arranged on the side of the container opposite the discharge piston, the rear part and the front part of the interior being connected to one another in a fluid-conducting manner via a conduit and through By advancing the delivery piston in the direction of the discharge piston, the container is to be opened by disintegrating into a large number of container sections, so that the monomer liquid can flow into the rear part of the interior.

The invention further relates to a method for providing a bone cement dough from two starting components using such a device.

Background of the invention

Significant efforts are being made to demonstrate devices and methods for providing bone cement by means of which bone cement dough can be provided easily, safely and quickly. An important aspect when providing bone cement dough is to avoid air pockets in the bone cement. To avoid this, a large number of vacuum cementing systems have been described, of which the following are examples: US 6,033,105 A , US 5,624,184 A , US 4,671,263 A , US 4,973,168 A , US 5,100,241 A , WO 99/67015 A1 , EP 1020167 A2 , US 5,586,821 A , EP 1016452 A2 , DE 3640279 A1 , WO 94/26403 A1 , EP 1005901 A2 , EP 1886647 A1 , US 5,344,232 A .

There is a desire in the market to simplify the provision of bone cement dough. A further development consists in the development of cementing systems in which both starting components are stored in separate areas of the mixing systems and are only mixed together in the cementing system immediately before the cementing application. Such closed, so-called full-prepacked systems, are mentioned in the following documents: EP 0 692 229 A1 , DE 10 2009 031 178 B3 , US 5,997,544 A , US 6,709,149 B1 , DE 698 12 726 T2 , EP 0 796 653 A2 , US 5,588,745 A .

In the EP 3 320 870 A1 A full prepack system is described, in which the container filled with monomer liquid is stored axially behind the bone cement powder within a cartridge. A discharge piston is arranged between the bone cement powder and the container. In order to provide the bone cement dough, a delivery piston, which is arranged on a side of the container opposite the discharge piston, is advanced in the direction of the discharge piston, which results in the container being opened by at least partially bursting the container into container sections. The monomer liquid emerging from the container is conveyed into the bone cement powder by continuing to advance the delivery piston, forming the bone cement dough. The container is compressed further and further, sometimes with further fragmentation of the container sections, until maximum compression is achieved. It has proven to be disadvantageous that a portion of the monomer liquid remains between the container sections, which is not available for forming the bone cement dough. This proportion can vary from application to application, so that the bone cement dough provided with the device described has varying mixing ratios of bone cement powder to monomer liquid and thus varying properties, such as viscosity and curing times. This makes application difficult for the surgeon. In addition, when the bone cement dough is discharged from the device, there can be a time-delayed delivery or "injection" of monomer liquid remaining between the container sections into the already formed bone cement dough, so that in particular the part of the bone cement dough facing the container sections has a larger proportion of monomer liquid to bone cement powder as the part of the bone cement dough facing away from the container sections and therefore the properties of the bone cement dough change in the course of discharge. The bone cement dough facing the container is "diluted" by the amount of monomer liquid subsequently introduced and has a lower viscosity than the bone cement dough initially discharged from the device.

In the EP 3 403 716 A1 , which discloses the preamble of claim 1, a full prepack system is described, wherein the container filled with monomer liquid is stored axially behind the bone cement powder within a cartridge. A discharge piston is arranged between the bone cement powder and the container. In order to provide the bone cement dough, a delivery piston, which is arranged on a side of the container opposite the discharge piston, is advanced in the direction of the discharge piston, which results in the container being opened by at least partially bursting the container into container sections. The container is there partially covered by foam, which serves as transport security and shock protection.

Tasks

An object of the present invention is to at least partially overcome one or more of the disadvantages resulting from the prior art.

In particular, the invention is based on the aim of providing devices which can provide a bone cement dough simply, safely, quickly and with a constant mixing ratio of bone cement powder and monomer liquid. The device should enable the monomer liquid to be conveyed as completely as possible into the bone cement powder, so that as little monomer liquid as possible remains between the container sections.

The device is intended to provide the bone cement without mechanical mixing of the starting components. The device should also be designed in such a way that the user does not have to carry out any assembly steps. The device should be able to provide the bone cement without an externally applied vacuum. The device should be able to discharge the bone cement provided. The device should be able to discharge the provided bone cement without any modifications. The device should be able to provide and discharge the bone cement without any modifications and without external equipment, such as hoses, vacuum sources or squeezing devices. The device should be able to be operated with as few steps as possible in order to minimize sources of error by the user.

It is a further object of the invention to provide a method with which bone cement can be provided from two starting components, by means of which at least some of the tasks already described are at least partially solved.

Preferred embodiments of the invention

A contribution to at least partial fulfillment of at least one of the aforementioned tasks is made by the features of the independent claims. The dependent ones Claims provide preferred embodiments that contribute to at least partial fulfillment of at least one of the tasks.

• eine hohlzylinderförmige Kartusche mit einem Innenraum, wobei in einem vorderen Teil des Innenraums ein Knochenzementpulver als erste Ausgangskomponente und in einem hinteren Teil des Innenraums ein Behälter enthaltend eine Monomerflüssigkeit als zweite Ausgangskomponente lagert,
• wobei zwischen dem Knochenzementpulver und dem Behälter ein axial im Innenraum beweglicher Austragskolben und auf der dem Austragskolben gegenüberliegenden Seite des Behälters ein axial im Innenraum beweglicher Förderkolben angeordnet ist, wobei der hintere Teil und der vordere Teil des Innenraums über ein Leitungsmittel fluidleitend miteinander verbunden sind und durch Vortreiben des Förderkolbens in Richtung des Austragskolbens der Behälter durch Zerfall in eine Vielzahl an Behälterteilstücken zu öffnen ist, so dass die Monomerflüssigkeit in den hinteren Teil des Innenraums fließbar ist,
• wobei
• im hinteren Teil des Innenraums ein volumenstabiles Verdrängungsmittel angeordnet ist, welches ausgestaltet ist, mit fortschreitendem Vortreiben des Förderkolbens in Richtung des Austragskolbens die Behälterteilstücke unter Verdrängung der Monomerflüssigkeit zwischen den Behälterteilstücken zu umschließen um die Monomerflüssigkeit aus dem hinteren Teil über das Leitungsmittel in den vorderen Teil des Innenraums zu fördern,
• dadurch gekennzeichnet, dass
• das Verdrängungsmittel ein Hartfett und/oder ein Wachs mit einem Schmelzpunkt von mindestens 40 °C umfasst.

A first embodiment of the invention is a device for providing a bone cement dough from two starting components

• a hollow cylindrical cartridge with an interior, wherein a bone cement powder is stored as the first starting component in a front part of the interior and a container containing a monomer liquid is stored as the second starting component in a rear part of the interior,
• wherein a discharge piston which is axially movable in the interior is arranged between the bone cement powder and the container and a delivery piston which is axially movable in the interior is arranged on the side of the container opposite the discharge piston, the rear part and the front part of the interior being connected to one another in a fluid-conducting manner via a conduit and through By advancing the delivery piston in the direction of the discharge piston, the container is to be opened by breaking it down into a large number of container sections, so that the monomer liquid can flow into the rear part of the interior,
• where
• A volume-stable displacement means is arranged in the rear part of the interior, which is designed to enclose the container sections while displacing the monomer liquid between the container sections as the delivery piston progresses in the direction of the discharge piston in order to move the monomer liquid from the rear part via the line means into the front part of the to promote interior space,
• characterized in that
• the displacing agent comprises a hard fat and/or a wax with a melting point of at least 40 °C.

• eine hohlzylinderförmige Kartusche mit einem Innenraum, wobei in einem vorderen Teil des Innenraums ein Knochenzementpulver als erste Ausgangskomponente und in einem hinteren Teil des Innenraums ein Behälter enthaltend eine Monomerflüssigkeit als zweite Ausgangskomponente lagert,
• wobei zwischen dem Knochenzementpulver und dem Behälter ein axial im Innenraum beweglicher Austragskolben und auf der dem Austragskolben gegenüberliegenden Seite des Behälters ein axial im Innenraum beweglicher Förderkolben angeordnet ist, wobei der hintere Teil und der vordere Teil des Innenraums über ein Leitungsmittel fluidleitend miteinander verbunden sind und durch Vortreiben des Förderkolbens in Richtung des Austragskolbens der Behälter durch Zerfall in eine Vielzahl an Behälterteilstücken zu öffnen ist, so dass die Monomerflüssigkeit in den hinteren Teil des Innenraums fließbar ist,
• wobei
• im hinteren Teil des Innenraums ein volumenstabiles Verdrängungsmittel angeordnet ist, welches ausgestaltet ist, mit fortschreitendem Vortreiben des Förderkolbens in Richtung des Austragskolbens die Behälterteilstücke unter Verdrängung der Monomerflüssigkeit zwischen den Behälterteilstücken zu umschließen um die Monomerflüssigkeit aus dem hinteren Teil über das Leitungsmittel in den vorderen Teil des Innenraums zu fördern,
• dadurch gekennzeichnet, dass
• das Verdrängungsmittel eine Vielzahl, dies bedeutet mindestens zwei, von Partikeln mit einer Shore A Härte von kleiner oder gleich 80, bevorzugt von kleiner oder gleich 50, weiter bevorzugt von kleiner oder gleich 30, umfasst.

A second embodiment of the invention is a device for providing a bone cement dough from two starting components

• a hollow cylindrical cartridge with an interior, wherein a bone cement powder is stored as the first starting component in a front part of the interior and a container containing a monomer liquid is stored as the second starting component in a rear part of the interior,
• wherein a discharge piston which is axially movable in the interior is arranged between the bone cement powder and the container and a delivery piston which is axially movable in the interior is arranged on the side of the container opposite the discharge piston, the rear part and the front part of the interior being fluid-conducting to one another via a conduit are connected and by advancing the delivery piston in the direction of the discharge piston, the container can be opened by disintegrating into a large number of container sections, so that the monomer liquid can flow into the rear part of the interior,
• where
• A volume-stable displacement means is arranged in the rear part of the interior, which is designed to enclose the container sections while displacing the monomer liquid between the container sections as the delivery piston progresses in the direction of the discharge piston in order to move the monomer liquid from the rear part via the line means into the front part of the to promote interior space,
• characterized in that
• the displacement agent comprises a plurality, this means at least two, of particles with a Shore A hardness of less than or equal to 80, preferably less than or equal to 50, more preferably less than or equal to 30.

In one embodiment of the device, the large number of particles of the displacement agent are spherical, in particular spherical or ovoid. This embodiment is a third embodiment of the invention, which preferably depends on the second embodiment of the invention.

In one embodiment of the device, the particles of the displacement agent are made of silicone rubber, natural rubber, polyurethane-polyester rubber, polybutadiene-styrene rubber or mixtures of these substances. This embodiment is a fourth embodiment of the invention, which preferably depends on the second or third embodiment of the invention.

In one embodiment of the device, the particles of the displacement agent have a diameter in a range from 1 mm to 3.5 mm, preferably in a range from 1.3 mm to 3.0 mm, more preferably in a range from 1.5 mm to 2.5 mm, on. This embodiment is a fifth embodiment of the invention, which preferably depends on the second, third or fourth embodiments of the invention.

• eine hohlzylinderförmige Kartusche mit einem Innenraum, wobei in einem vorderen Teil des Innenraums ein Knochenzementpulver als erste Ausgangskomponente und in einem hinteren Teil des Innenraums ein Behälter enthaltend eine Monomerflüssigkeit als zweite Ausgangskomponente lagert,
• wobei zwischen dem Knochenzementpulver und dem Behälter ein axial im Innenraum beweglicher Austragskolben und auf der dem Austragskolben gegenüberliegenden Seite des Behälters ein axial im Innenraum beweglicher Förderkolben angeordnet ist, wobei der hintere Teil und der vordere Teil des Innenraums über ein Leitungsmittel fluidleitend miteinander verbunden sind und durch Vortreiben des Förderkolbens in Richtung des Austragskolbens der Behälter durch Zerfall in eine Vielzahl an Behälterteilstücken zu öffnen ist, so dass die Monomerflüssigkeit in den hinteren Teil des Innenraums fließbar ist,
• wobei
• im hinteren Teil des Innenraums ein volumenstabiles Verdrängungsmittel angeordnet ist, welches ausgestaltet ist, mit fortschreitendem Vortreiben des Förderkolbens in Richtung des Austragskolbens die Behälterteilstücke unter Verdrängung der Monomerflüssigkeit zwischen den Behälterteilstücken zu umschließen um die Monomerflüssigkeit aus dem hinteren Teil über das Leitungsmittel in den vorderen Teil des Innenraums zu fördern,
• dadurch gekennzeichnet, dass
• das Verdrängungsmittel eine Paste beinhaltend einen pulverförmigen Feststoff und eine Flüssigkeit umfasst.

A sixth embodiment of the invention is a device for providing a bone cement dough from two starting components

• a hollow cylindrical cartridge with an interior, wherein in a front part of the interior a bone cement powder as the first starting component and in a rear Part of the interior stores a container containing a monomer liquid as a second starting component,
• wherein a discharge piston which is axially movable in the interior is arranged between the bone cement powder and the container and a delivery piston which is axially movable in the interior is arranged on the side of the container opposite the discharge piston, the rear part and the front part of the interior being connected to one another in a fluid-conducting manner via a conduit and through By advancing the delivery piston in the direction of the discharge piston, the container is to be opened by breaking it down into a large number of container sections, so that the monomer liquid can flow into the rear part of the interior,
• where
• A volume-stable displacement means is arranged in the rear part of the interior, which is designed to enclose the container sections while displacing the monomer liquid between the container sections as the delivery piston progresses in the direction of the discharge piston in order to move the monomer liquid from the rear part via the line means into the front part of the to promote interior space,
• characterized in that
• the displacement agent comprises a paste containing a powdery solid and a liquid.

In one embodiment of the device, the displacement agent comprises propane-1,2,3-triol as a liquid and silicon dioxide as a solid. This embodiment is a seventh embodiment of the invention, which preferably depends on the sixth embodiment of the invention.

In one embodiment of the device, the silicon dioxide comprises fumed silicon dioxide, precipitated silicon dioxide or a mixture of fumed and precipitated silicon dioxide. This embodiment is an eighth embodiment of the invention, which preferably depends on the seventh embodiment of the invention.

In one embodiment of the device, the displacement agent occupies a displacement agent volume which corresponds to at least a total volume of the container sections. This embodiment is a ninth embodiment of the invention, which preferably depends on one of the previous embodiments of the invention.

In one embodiment of the device, the displacement means is at least partially arranged between the container and the delivery piston. This embodiment is a tenth embodiment of the invention, which preferably depends on one of the previous embodiments of the invention.

In one embodiment of the device, the displacement means is at least partially arranged radially around the container. This embodiment is an eleventh embodiment of the invention, which preferably depends on one of the previous embodiments of the invention.

In one embodiment of the device, the displacing agent is essentially insoluble in the monomer liquid at room temperature, i.e. in the range from 15°C to 30°C. This embodiment is a twelfth embodiment of the invention, which preferably depends on the first, second or sixth embodiments of the invention.

1. a. Vortreiben des Förderkolbens in Richtung des Austragskolbens unter Zerfall des Behälters in eine Vielzahl an Behälterteilstücken,
2. b. Zusammenschieben der Behälterteilstücke durch fortgesetztes Vortreiben des Förderkolbens,
3. c. Verdrängen der Monomerflüssigkeit zwischen den Behälterteilstücken durch das Verdrängungsmittel unter Fördern der Monomerflüssigkeit in den vorderen Teil des Innenraums zum Ausbilden des Knochenzementteiges.

A thirteenth embodiment of the invention is a method for providing a bone cement dough from two starting components by means of a device according to one of the preceding embodiments, comprising the following steps:

1. a. Advancing the delivery piston in the direction of the discharge piston, with the container disintegrating into a large number of container sections,
2. b. Pushing the container sections together by continuously driving the delivery piston,
3. c. Displacing the monomer liquid between the container sections by the displacing means while conveying the monomer liquid into the front part of the interior to form the bone cement dough.

In one embodiment of the method, the device is inserted into a discharge device to advance the delivery piston. This embodiment is a fourteenth embodiment of the invention, which preferably depends on the fourteenth embodiment of the invention.

In one embodiment of the method, the monomer liquid is distributed in the bone cement powder using a hydrophilic additive. This embodiment is one fifteenth embodiment of the invention, which preferably depends on the fourteenth or fifteenth embodiment of the invention.

General

In this description, range information also includes the values mentioned as limits. A specification of the type "in the range from X to Y" with respect to a quantity A therefore means that A can take on the values X, Y and values between X and Y. One-sided limited areas of the type "up to Y" for a size A mean correspondingly as a value Y and smaller than Y.

Some of the features described are linked to the term “substantially”. The term "essentially" is to be understood as meaning that under real conditions and manufacturing techniques, a mathematically exact interpretation of terms such as "superposition", "vertical", "diameter" or "parallelism" can never be given exactly, but only within certain manufacturing error tolerances can. For example, "substantially parallel axes" include an angle of 85 degrees to 95 degrees to each other and "substantially equal volumes" include a deviation of up to 5% by volume. A “device consisting essentially of plastic” includes, for example, a plastic content of ≥95 to ≤100% by weight. A “substantially complete filling of a volume B” includes, for example, a filling of ≥95 to ≤100% by volume of the total volume of B.

Detailed description

• eine hohlzylinderförmige Kartusche mit einem Innenraum, wobei in einem vorderen Teil des Innenraums ein Knochenzementpulver als erste Ausgangskomponente und in einem hinteren Teil des Innenraums ein Behälter enthaltend eine Monomerflüssigkeit als zweite Ausgangskomponente lagert,
• wobei zwischen dem Knochenzementpulver und dem Behälter ein axial im Innenraum beweglicher Austragskolben und auf der dem Austragskolben gegenüberliegenden Seite des Behälters ein axial im Innenraum beweglicher Förderkolben angeordnet ist, wobei der hintere Teil und der vordere Teil des Innenraums über ein Leitungsmittel fluidleitend miteinander verbunden sind und durch Vortreiben des Förderkolbens in Richtung des Austragskolbens der Behälter durch Zerfall in eine Vielzahl an Behälterteilstücken zu öffnen ist, so dass die Monomerflüssigkeit in den hinteren Teil des Innenraums fließbar ist.

The invention relates to a device for providing a bone cement dough comprising two starting components

• a hollow cylindrical cartridge with an interior, wherein a bone cement powder is stored as the first starting component in a front part of the interior and a container containing a monomer liquid is stored as the second starting component in a rear part of the interior,
• wherein a discharge piston which is axially movable in the interior is arranged between the bone cement powder and the container and a delivery piston which is axially movable in the interior is arranged on the side of the container opposite the discharge piston, the rear part and the front part of the interior being connected to one another in a fluid-conducting manner via a conduit and through By advancing the delivery piston in the direction of the discharge piston, the container is to be opened by disintegrating into a large number of container sections, so that the monomer liquid can flow into the rear part of the interior.

In order to overcome the above-mentioned disadvantages in the prior art, it is provided according to the invention that a volume-stable displacement means is arranged in the rear part of the interior, which is designed to enclose the container sections while displacing the monomer liquid between the container sections as the delivery piston progresses in the direction of the discharge piston to convey the monomer liquid from the rear part via the conduit to the front part of the interior.

The displacement means thus fills an intermediate space between the container sections, which after opening the container and possible further fragmentation of the container sections into smaller container sections is filled with the monomer liquid and / or a gas, such as air or nitrogen, and displaces the monomer liquid present there. Since the rear part of the interior is closed in a fluid-tight manner by the delivery piston on a side opposite the line means, the monomer liquid is fed into the bone cement powder via the line means with continued advancement of the delivery piston, and thus also with continued filling of the space between the container sections by the displacement agent front part of the interior promoted. The device thus ensures almost complete mixing of bone cement powder and monomer liquid, which allows bone cement dough with a consistent bone cement dough composition to be prepared easily, quickly and safely.

The device has a hollow cylindrical cartridge. A hollow cylindrical cartridge is to be understood as meaning a tube-like container which has an interior and a cartridge wall surrounding the interior. The cross section of the cartridge can take any shape. Due to the simple production and the safer use of the device, the cross section, and preferably also the cross section of the interior, is circular. This allows easy handling for the user and, due to the absence of edges, reduces the risk of moving parts becoming wedged within the device. According to the invention, the cartridge can consist of a wide variety of materials or combinations of materials. For example, the device can be made of plastic. The plastic is preferably a transparent plastic, since in this way the user can visually check that the device is functioning properly during use.

A discharge piston that is axially movable in the interior is arranged between the bone cement powder and the container. The discharge piston serves to spatially separate the container and bone cement powder, so that neither bone cement powder is transferred from the front part of the interior to the rear part of the interior, nor the container or container sections after opening the container, from the rear part of the interior to the front part of the interior can reach. The latter in particular prevents bone cement dough interspersed with container sections, which could pose health risks for the patient and impair proper discharge of the bone cement dough from the device. The discharge piston continues to serve to discharge the provided bone cement dough from the device. For this purpose, the discharge piston can be moved from its original position towards a discharge opening of the device. The discharge opening is preferably located on a side of the bone cement powder that is axially opposite the discharge piston.

The device has a delivery piston that is axially movable in the interior. The delivery piston is arranged on the side of the container axially opposite the discharge piston within the device. By propelling, that is, by a relative movement of the delivery piston in the direction of the discharge piston, which shortens the distance between the delivery piston and the discharge piston within the interior, the container opens. Opening of the container occurs when the distance between the delivery piston and the discharge piston is reduced such that the container is subjected to a resulting force that is greater than the structural integrity of the container. As a result, the container breaks down into a large number, that is to say at least two, of container sections, so that a monomer liquid can escape from the interior of the container into the rear part of the interior of the cartridge. A continued advancement of the delivery piston in the direction of the discharge piston leads, in particular with the cooperation of the displacement means, to the monomer liquid being conveyed from the rear part of the interior of the device via the line means into the front part of the interior of the device. This brings bone cement powder and monomer liquid into contact, forming a bone cement dough.

A container containing a monomer liquid is stored within the rear part of the interior of the device. Such a container is understood to mean a storage option that can store the monomer liquid in a hermetically sealed and sterile manner and can be destroyed by manual force. Examples of containers containing the monomer liquid are Glass ampoules, plastic ampoules and plastic bags. Glass ampoules are preferred due to their ability to be easily sterilized and easily opened by manual force.

The device has a conduit through which the rear part and the front part of the interior are connected in a fluid-conducting manner. Fluid-conducting means that the rear part and the front part of the interior are connected so that they are permeable to liquids, in particular the monomer liquid, and to gases. In order to prevent bone cement powder from getting from the front part into the rear part of the interior and the container, or the container sections, from the rear part into the front part of the interior via the conduit, the conduit is preferably equipped with a filter medium, in particular one Pore disk, for example made of sintered polypropylene particles, made of cellulose felt or made of cardboard, can be arranged, which makes the conduit impermeable to solids. In a variant of the device, at least one passage is provided as a line means in the discharge piston and/or between the discharge piston and the inner wall of the interior, through which the rear part and the front part of the interior are connected to one another in a fluid-conducting manner. A filter that is impermeable to the bone cement powder and permeable to the monomer liquid and gases, for example a pore disk, for example made of sintered polypropylene particles, made of cellulose felt or made of cardboard, can be arranged in or at one or both ends of the at least one feedthrough. In a further variant of the device, the line means is one or more lines which is or are arranged on the outside of the cartridge or in the cartridge wall and which connects or connects the rear part and the front part of the interior through passages in the cartridge wall or through openings. The discharge piston is bypassed in this variant.

By advancing the delivery piston in the direction of the discharge piston, it is achieved that the monomer liquid within the interior of the cartridge can be transferred via the conduit from the rear part of the interior to the front part of the interior, in which the bone cement powder is located.

A variant of the device is designed so that continued advancement of the delivery piston in the direction of the discharge piston after the monomer liquid has been conveyed from the rear part of the interior into the front part of the interior causes the discharge piston to advance in the direction of the discharge opening of the device. In this way, the bone cement dough provided by mixing bone cement powder and monomer liquid can be discharged from the device through the discharge opening become. This ensures in a simple manner that the bone cement dough can be expelled from the cartridge with the same drive that is also used to open the container and to convey the monomer liquid, namely with the unidirectionally driven delivery piston.

In order to prevent unwanted advancement of the discharge piston in the direction of the discharge opening, a locking means can be arranged on the discharge piston, so that the discharge piston can lock between the front part and the rear part of the interior with the cartridge, in particular with the cartridge wall, this locking by the forces occurring when the container is opened and a pressure exerted on the monomer liquid by the delivery piston, or by the delivery piston and displacement means, when the monomer liquid is conveyed into the front part of the interior cannot be released, but by direct pressure from the delivery piston or delivery piston , displacement means and any container sections located in between, pressure acting on the discharge piston can be released.

The locking means ensures that the container can first be opened by advancing the delivery piston and the monomer liquid flowing out from it is released with the delivery piston, or with the delivery piston in interaction with the displacement means, then into the front part of the interior of the cartridge, i.e. into the bone cement powder , can be pressed, with the discharge piston maintaining its original position relative to the cartridge and the interior. Only after the monomer liquid has largely been pressed into the bone cement powder, and thus the bone cement dough is in the front part of the interior of the cartridge, can the bone cement dough then be pressed out of the front part of the cartridge using the discharge piston. The force to release the detent is therefore greater than the force required to open the container and convey the monomer liquid via the conduit into the front part of the interior.

When opened, the container breaks down into a large number of container sections, allowing the monomer liquid to flow into the rear part of the interior of the cartridge. The opening occurs by advancing the delivery piston in the direction of the discharge piston. As a result of continued advancement, the container sections created when the container is opened can in turn break into a large number of smaller container sections. If the delivery piston has been moved far enough in the direction of the discharge piston, the monomer liquid begins to be delivered from the rear part of the interior via the conduit into the front part of the interior with the formation of the bone cement dough. A complete advancement of the delivery piston, so that delivery piston and discharge piston touch each other directly, can be prevented due to the container sections, especially if the opposite sides of the discharge piston and delivery piston are designed to be flat. The container sections can break down into smaller and smaller container sections as the delivery piston and discharge piston move closer together, but there will always be a gap between the backs of the container sections, which is filled with the monomer liquid and/or gas present in the interior. In order to convey the monomer liquid remaining in the gap as completely as possible into the front part of the interior, a volume-stable displacement means is arranged in the rear part of the interior.

A volume-stable displacement agent is to be understood as meaning a plastically and/or elastically deformable material. The displacement agent comprises in particular a solid and/or a flowable substance with a higher viscosity than the monomer liquid. According to the invention, a material is to be regarded as volume-stable if it is under the pressure conditions of up to 0.5 kN/cm ² that arise when using the device, in particular when opening the container, when conveying the monomer liquid and, preferably, when discharging the bone cement dough provided the device causes no or only an insignificant change in volume of the displacement agent. Gases, for example, are not stable in volume when pressure is applied. The displacement means is suitable for enclosing the container sections under the pressure conditions acting when conveying the monomer liquid from the rear part of the interior into the front part of the interior in such a way that monomer liquid present in the space between the container sections is conveyed through the line means into the front part of the interior in order to be available for the formation of the bone cement dough without being conveyed into the front part of the interior. For this purpose, the displacement agent can contain at least a portion of a solid and/or the displacement agent has such a high viscosity that conveying into the front part of the interior through the conduit, in particular through a conduit equipped with a filter agent, such as a pore disk, is impossible the pressure conditions used are omitted. The displacement agent fills the space between the container sections as completely as possible, so that the monomer liquid is displaced as completely as possible from the space.

In order to prevent contamination of the monomer liquid by the displacing agent, it is preferred that the displacing agent is essentially insoluble in the monomer liquid, in particular in methyl methacrylate, at room temperature (15 to 30 ° C). In particular, it is preferred that the displacing agent is soluble with a maximum of 10 g in 1 liter of methyl methacrylate with a contact time with the methyl methacrylate of 120 seconds. Preferably the displacing agent does not dissolve at all in the monomer liquid, especially in methyl methacrylate.

The displacing agent comprises a hard fat and/or a wax with a melting point of at least 40° C. or a plurality of particles with a Shore A hardness of less than or equal to 80 or a paste containing a powdery solid and a liquid.

One embodiment of the device is characterized in that the displacement agent comprises a hard fat and/or a wax with a melting point of at least 40 ° C. The displacement agent can therefore be a hard fat (adpes solidus, for example the hard fat CAS 67701-26-2 ) with a melting point of at least 40 °C, a wax with a melting point of at least 40 °C or a mixture of a hard fat with a melting point of at least 40 °C and a wax with a melting point of at least 40 °C. According to the invention, paraffins, such as Fischer-Tropsch waxes ( CAS 8002-74-2 ), amide waxes ( CAS 110-30-5 ) or waxy fatty acid esters of natural origin, such as beeswax ( CAS 18012-89-3 ), understood. The waxes can be used in their pure form or using plasticizers, for example from the group of fatty acid isopropyl esters or liquid paraffins. The hard fats can be used in pure form or with the addition of other compounds, such as glycerol tripalmate, glycerol trilaurate or glycerol tristearate. By adding glycerol trifatty acid esters that melt above 40 °C, the melting point of the hard fat can be increased.

One embodiment of the device is characterized in that the displacement agent comprises a large number of particles with a Shore A hardness of less than or equal to 80, preferably less than or equal to 50, more preferably less than or equal to 30. The determination of the Shore A hardness of a given material is known to those skilled in the art. Such particles can penetrate into the space between the container sections and are soft enough that when the delivery piston is advanced in the direction of the discharge piston prevailing pressure conditions, an elastic and/or plastic deformation of the particles takes place, so that the particles compact while displacing the cavity between the individual particles. This allows the monomer liquid to be displaced as completely as possible from the space between the container sections while conveying the monomer liquid via the conduit into the front part of the interior. In addition, the container sections are surrounded as completely as possible, since the particles “nestle” to them.

The particles can have different shapes. Due to the better flowability and the associated better penetration into the space between the container sections, a spherical particle shape is preferred. For example, the particles can have a spherical or ovoid particle shape.

The particles can comprise different materials or consist of different materials as long as they have a Shore A hardness of less than or equal to 80, preferably less than or equal to 50, more preferably less than or equal to 30.

One embodiment of the device is characterized in that the particles are made of silicone rubber, natural rubber, polybutadiene-styrene rubber and/or polyurethane-polyester rubber. The particles can consist entirely or at least partially of the materials mentioned. If the particles only partially consist of the materials mentioned, it is preferred that the materials mentioned are arranged on a surface of the particles, so that the aforementioned compression of the particles can take place when the delivery piston is advanced in the direction of the discharge piston.

The particles can have different diameters.

One embodiment of the device is characterized in that the particles have a diameter in a range from 1 to 3.5 mm, preferably from 1.2 to 3.0 mm, more preferably from 1.5 to 2.5 mm. The diameter of the particles refers to the D50 value. Particles with these diameters allow easy introduction into the space between the container sections. In addition, such particles can be compacted well by the pressure conditions prevailing when the delivery piston is advanced in the direction of the discharge piston in order to achieve the most complete displacement of the monomer liquid from the space between the container sections.

One embodiment of the device is characterized in that the displacement agent comprises a paste containing a powdery solid and a liquid.

A variety of different materials are suitable as powdery solids, as long as they can be brought into a paste-like form using a liquid and possibly other additives, such as binders such as cellulose, wetting agents and/or thixotropic agents. In one embodiment, the powdery solid comprises the above-described particles with a Shore A hardness of less than or equal to 80, preferably less than or equal to 50, more preferably less than or equal to 30, or consists of these particles. In a further embodiment, the powdery solid comprises a material which has a greater hardness than the particles described above.

The powdery solid preferably has solid particles with a diameter in a range from 1 to 3.5 mm, preferably from 1.2 to 3.0 mm, more preferably from 1.5 to 2.5 mm. The diameter of the particles refers to the D50 value. Solid particles with these diameters allow the paste to be easily introduced into the space between the container sections.

A variety of different liquids of organic or inorganic nature can be used as liquid. Examples of organic liquids include alcohols, particularly polyalcohols such as glycerin, hydrocarbons and aromatic solvents. Examples of inorganic liquids include water and aqueous solutions.

One embodiment of the device is characterized in that the paste comprises propane-1,2,3-triol (glycerin) as a liquid and silicon dioxide as a powdery solid. In a variant of the embodiment, the paste consists of silicon dioxide and propane-1,2,3-triol. An advantage of propane-1,2,3-triol is that it is non-toxic to the human body and has a high boiling point.

The silicon dioxide can have different shapes and/or properties.

One embodiment of the device is characterized in that the silicon dioxide comprises or consists of fumed silicon dioxide (fumed silica), precipitated silicon dioxide or a mixture of fumed and precipitated silicon dioxide.

One advantage is that pasty displacing agents can be produced particularly easily from these types of silicon dioxide due to the respective high BET surfaces.

The displacement agent can occupy different volume proportions of the interior, in particular the rear part of the interior.

One embodiment of the device is characterized in that the displacement agent occupies a displacement agent volume which corresponds to at least a total volume of the container sections. The total volume of the container sections corresponds to the volumes of all container sections into which the container collapses when the delivery piston is opened or advanced. The total volume of the container sections therefore corresponds to a volume which, through the wall of the container, or through the walls of the container sections, itself, i.e. does not correspond to the space enclosed by the container. The displacement agent preferably has a displacement agent volume which corresponds to at least 1.5 times, more preferably at least 2 times, most preferably at least 2.5 times the total volume of the container sections. In this way, it is possible to enclose the container sections as completely as possible by the displacement means and thus to convey the monomer liquid as completely as possible from the space between the container sections into the front part of the interior. So that the interior of the cartridge and thus the device itself does not have to be made too large and therefore too unwieldy, it is preferred that the displacement agent volume does not correspond to more than 6 times the total volume of the container sections.

The displacement means can be arranged at different locations within the rear part of the interior of the cartridge.

One embodiment of the device is characterized in that the displacement means is at least partially arranged between the container and the delivery piston. For example, at least 10% by volume, preferably at least 25% by volume, more preferably at least 50% by volume of the displacement agent can be arranged between the container and the delivery piston. An advantage here is that such an arrangement allows the displacement means to be easily pushed into the container sections as the delivery piston continues to advance in the direction of the discharge piston, since the displacement means is already pushed in the direction of the container due to its spatial arrangement. A further advantage is that the displacement means arranged in this way allows the monomer liquid to be displaced in a targeted manner in the direction of the line means.

One embodiment of the device is characterized in that the displacement means is at least partially arranged radially around the container. An advantage here is that the displacement means thereby exerts a stabilizing, holding effect on the container, so that it can be stored safely and with a reduced risk of accidental breakage within the rear part of the interior of the cartridge. In one embodiment, the displacement means extends around the entire radial circumference of the container and thus surrounds the container in a sleeve-like manner. In a further embodiment, the displacement means does not extend completely around the entire radial circumference of the container, but rather only surrounds the container, for example, on 50% of the radial circumference. In the aforementioned embodiments, the displacement element can extend over the entire length of the container or only over one or more partial lengths of the container.

In one embodiment, the delivery piston has a receptacle which is open in the direction of the container and in which the displacement means is arranged. Preferably, the container is partially inserted into the receptacle with an axial end pointing in the direction of the delivery piston, so that the displacement means at least partially encloses this axial end of the container. As a result, the container is radially surrounded by the displacement means at least at this axial end and is therefore spatially fixed. Preferably, the container is only inserted into the receptacle to such an extent that displacement means is also arranged between the container and the delivery piston. One advantage is that the container is secured in this way by the displacement means within the interior of the cartridge in such a way that the risk of accidental breakage of the container, for example due to jerky movements of the device, is reduced.

Preferably, no displacement means is arranged between the container and the discharge piston within the rear part of the interior of the cartridge, so that the monomer liquid does not have to be conveyed through or past the displacement means through the line means into the front part of the interior of the cartridge. This allows the monomer liquid to be pumped into the bone cement powder with as little effort as possible by the user of the device.

1. a. Vortreiben des Förderkolbens in Richtung des Austragskolbens unter Zerfall des Behälters in eine Vielzahl an Behälterteilstücken,
2. b. Zusammenschieben der Behälterteilstücke durch fortgesetztes Vortreiben des Förderkolbens,
3. c. Verdrängen der Monomerflüssigkeit zwischen den Behälterteilstücken durch das Verdrängungsmittel unter Fördern der Monomerflüssigkeit in den vorderen Teil des Innenraums zum Ausbilden des Knochenzementteiges.

A further subject of the invention relates to a method for providing a bone cement dough from two starting components by means of a device, in particular by means of a device according to one of the preceding embodiments, comprising the following steps:

1. a. Advancing the delivery piston in the direction of the discharge piston, with the container disintegrating into a large number of container sections,
2. b. Pushing the container sections together by continuously driving the delivery piston,
3. c. Displacing the monomer liquid between the container sections by the displacing means while conveying the monomer liquid into the front part of the interior to form the bone cement dough.

Depending on the container used, for example when using a glass ampoule as a container, when the container sections created when the container is opened are pushed together, the container sections, or at least one or more of the initial container sections, can be further fragmented into further, smaller container sections. Regardless of this further fragmentation, a space will always remain between the container sections, in which at least part of the monomer liquid remains. If the container sections cannot be pushed together any further by further advancing the delivery piston in the direction of the discharge piston, the displacement means stored in the rear part of the interior is introduced into the space between the container sections at this point at the latest. The displacement means will accommodate the container sections by enclosing them and thereby displace the monomer liquid remaining in the gap from the gap. The displacement means is preferably designed in such a way that it essentially cannot absorb the monomer liquid. Since the rear part of the interior is closed at one axial end by the delivery piston, the only path left for the monomer liquid is through the conduit into the front part of the interior. There it comes into contact with the bone cement powder to form the bone cement dough.

The delivery piston can be advanced into the cartridge in the direction of the discharge piston in different ways. For example, a user of the device can advance the delivery piston manually, in particular by applying force to a rod or axle. In a further embodiment, the cartridge and the delivery piston together form a thread, via which the delivery piston can be screwed into the cartridge in the direction of the discharge piston. The cartridge preferably has an internal thread and the delivery piston has an external thread, which interact positively and/or non-positively to enable the delivery piston to be advanced.

In a further embodiment of the method, the delivery piston is advanced using a mechanical aid.

One embodiment of the method is characterized in that to advance the delivery piston, the device is inserted into a discharge device, in particular a discharge gun for bone cement dough. Dispensing guns for bone cement dough are known to those skilled in the art.

When the monomer liquid is conveyed from the rear part to the front part of the interior, the formation of the bone cement dough from the two starting components begins. This is preferably done with the two starting components mixed as evenly as possible in order to obtain a bone cement dough that is as homogeneous as possible. The two components can be mixed in different ways. In one embodiment of the method, the mixing takes place with the active participation of the user of the device, for example by shaking the device or by actuating a mixing element in the front part of the interior, in particular a stirrer.

One embodiment of the method is characterized in that the monomer liquid is distributed in the bone cement powder with the aid of a hydrophilic additive. An advantage is that this occurs without active involvement of the user of the device, which avoids possible errors by the user during mixing. A possible error is that the user does not mix the entire length of the front portion of the interior, so that portions of the bone cement powder are not wetted with monomer fluid. A further advantage is that the device can thereby be designed more simply and with fewer moving components, which reduces both the risk of malfunctions and the manufacturing costs of the device.

The device according to the invention is characterized in that it provides a bone cement dough from two starting components. A bone cement dough is a substance that is suitable in the field of medical technology to create a stable connection between artificial joints, such as hip and knee joints, and bone material. Hardening turns a bone cement dough into a bone cement. These are preferred Bone cements include polymethyl methacrylate bone cements (PMMA bone cements). PMMA bone cements have long been used in medical applications and go back to the work of Sir Charnley (cf. Charnley, J. Anchorage of the femoral head prosthesis of the shaft of the femur. J. Bone Joint Surg. 1960; 42, 28-30 .). PMMA bone cements can be produced from a bone cement powder as the first starting component and a monomer liquid as the second starting component. If the composition is suitable, the two starting components can be stored separately from one another. When the two starting components come into contact, a plastically deformable bone cement dough is created due to the swelling of the polymer components of the bone cement powder. Polymerization of the monomer is initiated by radicals. As the polymerization of the monomer progresses, the viscosity of the bone cement dough increases until it hardens completely.

A bone cement powder is understood to mean a powder which comprises at least one particulate polymethyl methacrylate and/or one particulate polymethyl methacrylate copolymer. Examples of copolymers are styrene and/or methyl acrylate. In one embodiment, the bone cement powder may additionally comprise a hydrophilic additive which supports the distribution of the monomer liquid within the bone cement powder. In a further embodiment, the bone cement powder can additionally comprise an initiator, which initiates the polymerization. In a further embodiment, the bone cement powder can additionally comprise an X-ray opaque. In yet another embodiment, the bone cement powder can additionally comprise pharmaceutically active substances, such as antibiotics.

The bone cement powder preferably comprises, as a hydrophilic additive, at least one particulate polymethyl methacrylate and/or a particulate polymethyl methacrylate copolymer, an initiator and an X-ray opaque or consists of these components. More preferably, the bone cement powder comprises at least one particulate polymethyl methacrylate and/or a particulate polymethyl methacrylate copolymer, an initiator, an X-ray opaque and a hydrophilic additive or consists of these components. Most preferably, the bone cement powder comprises or consists of at least one particulate polymethyl methacrylate and/or a particulate polymethyl methacrylate copolymer, an initiator, a radiopaque, a hydrophilic additive and an antibiotic.

According to the invention, the particle size of the particulate polymethyl methacrylate and/or the particulate polymethyl methacrylate copolymer of the bone cement powder can correspond to the sieve fraction of less than 150 μm, preferably less than 100 μm.

According to the invention, the hydrophilic additive can be designed to be particulate and/or fibrous. In a further embodiment, the hydrophilic additive can be slightly soluble, preferably insoluble, in methyl methacrylate. In a further embodiment, the hydrophilic additive can have an absorption capacity of at least 0.6 g of methyl methacrylate per gram of hydrophilic additive. In a further embodiment, the hydrophilic additive can have a chemical substance with at least one OH group. It can preferably be provided that the hydrophilic additive has covalently bonded OH groups on its surface. Examples of such preferred hydrophilic additives can be additives selected from the group comprising cellulose, oxycellulose, starch, titanium dioxide and silicon dioxide, with fumed silicon dioxide being particularly preferred. In one embodiment, the particle size of the hydrophilic additive of the sieve fraction can correspond to less than 100 μm, preferably less than 50 μm and most preferably less than 10 μm. The hydrophilic additive can be contained in an amount of 0.1 to 2.5% by weight based on the total weight of the bone cement powder.

According to the invention, the initiator can contain dibenzoyl peroxide or consist of dibenzoyl peroxide.

According to the invention, a radiopaque is understood to mean a substance which allows the bone cement to be made visible on x-ray diagnostic images. Examples of radiopaques may include barium sulfate, zirconia and calcium carbonate. According to the invention, the pharmaceutically active substance can comprise one or more antibiotics and optionally added co-factors for the one or more antibiotics. The pharmaceutically active substance preferably consists of one or more antibiotics and optionally added co-factors for the one or more antibiotics. Examples of antibiotics include gentamicin, clindamycin and vancomycin. According to the invention, the monomer liquid can comprise the monomer methyl methacrylate or consist of methyl methacrylate. In one embodiment, the monomer liquid comprises, in addition to the monomer, an activator dissolved therein, such as N,N-dimethyl-p-toluidine, or consists of methyl methacrylate and N,N-dimethyl-p-toluidine.

The features disclosed for the device are also disclosed for the method and vice versa.

characters

The invention is further illustrated by way of example below using figures. The invention is not limited to the figures.

Fig. 1

einen schematischen Querschnitt einer Vorrichtung zum Bereitstellen eines Knochenzementteigs,

Fig. 2

einen schematischen Querschnitt der Vorrichtung aus Figur 1 nach einem beginnenden Vortreiben eines Förderkolbens in Richtung eines Austragskolbens,

Fig. 3

einen schematischen Querschnitt der Vorrichtung aus den Figuren 1 und 2 nach einem Öffnen eines Behälters 300,

Fig. 4

einen schematischen Querschnitt der Vorrichtung aus den Figuren 1 bis 3 beim beginnenden Fördern einer Monomerflüssigkeit,

Fig. 5

einen schematischen Querschnitt der Vorrichtung aus den Figuren 1 bis 4 nach erfolgtem Fördern der Monomerflüssigkeit, und

Fig. 6

einen schematischen Querschnitt der Vorrichtung aus den Figuren 1 bis 5 beim Austragen des Knochenzementteigs.

Show it

Fig. 1

a schematic cross section of a device for providing a bone cement dough,

Fig. 2

a schematic cross section of the device Figure 1 after a delivery piston begins to advance in the direction of a discharge piston,

Fig. 3

a schematic cross section of the device from the Figures 1 and 2 after opening a container 300,

Fig. 4

a schematic cross section of the device from the Figures 1 to 3 when starting to pump a monomer liquid,

Fig. 5

a schematic cross section of the device from the Figures 1 to 4 after the monomer liquid has been conveyed, and

Fig. 6

a schematic cross section of the device from the Figures 1 to 5 when discharging the bone cement dough.

Description of the characters

Figure 1 shows a schematic cross section of an exemplary embodiment of a device 100 for providing a bone cement dough in an initial state. The device 100 is in one piece, but is made up of several components. The device 100 is constructed like a tube and includes a hollow cylindrical cartridge 200 with an interior 210. In a front part 220 of the interior 210 there is a bone cement powder 400 as a first starting component and in a rear part 230 of the interior 210 there is a container 300 in the form of a glass ampoule containing a monomer liquid 350 stored as the second starting component of the bone cement dough. The bone cement powder 400 contains particulate polymethyl methacrylate as the main component and a hydrophilic additive with which the monomer liquid 350 can be distributed in the bone cement powder 400.

The front part 220 and the rear part 230 of the interior 210 are separated by a discharge piston 250 that is movable axially in the interior 210. The discharge piston 250 is designed to be impermeable to solids, so that no bone cement powder 400 comes from the front Part 210 into the rear part 230 of the interior 210 and the container 300 cannot get from the rear part 230 to the front part 220 of the interior 210.

The discharge piston 250 has a line means 260 in the form of several passages through which there is a fluid-conducting connection between the front part 220 and the rear part 230. The line means 260 is formed as part of the discharge piston 250 in the embodiment of the device 100 shown. In further embodiments, not shown, the line means 260 can be formed separately from the discharge piston 250, for example as a tubular line outside the cartridge. The conduit 260 is closed by a pore disk 265 that is impermeable to solids and highly viscous liquids, such as hard fats, waxes, pastes or bone cement doughs, but which allows the monomer liquid 350 to be conveyed easily from the rear part 230 into the front part 220 of the interior 210. In the embodiment of the device 100 shown, the pore disk 265 is arranged on the end of the conduit 260 facing the front part 220 of the interior 210. In further embodiments, not shown, the pore disk 265, or other means, is arranged on the end of the conduit 260 facing the rear part 230 or at both ends of the conduit 260. An advantage of a pore disk arranged as shown is that the bone cement dough forming in the front part 220 of the interior 210 cannot clog the conduit 260.

On the side of the container 300 opposite the discharge piston 250, a delivery piston 270 which is axially movable within the interior 210 is arranged. The delivery piston 270 closes a back of the interior 210 of the cartridge 200.

So that monomer liquid 350 that has escaped from the container 300 is not pressed past the discharge piston 250 into the front part 220 of the interior 210, two radially circumferential sealing rings 255 made of rubber are provided on the discharge piston 250, with which the discharge piston 250 is sealed against the wall of the interior 210 . Likewise, two radially circumferential sealing rings 275 are provided on the delivery piston 270, with which the monomer liquid 350 is prevented from escaping past the delivery piston 270 and out of the device 100. The sealing effect of the sealing rings 275 on the delivery piston 270 must be sufficient, even if the delivery piston 270 exerts such great pressure on the monomer liquid 350 that it flows through the conduit 270 and the pore disk 265 from the rear part 230 into the front part 220 of the interior 210 is pressed in.

The device also has a discharge opening 280, which delimits the area of the front part 220 of the interior 210 of the cartridge 200 facing away from the discharge piston 250.

In the initial state of the device 100, the discharge opening 280 is closed by a closure cap 281 with a stopper 285, so that no bone cement powder 400 can escape from the cartridge 200.

A displacement means 500 is stored within the rear part 230 of the interior 210. In the embodiment shown, the displacement means 500 is arranged within a receptacle 271 of the delivery piston 270 in the initial state of the device 100. The displacement means 500 arranged in this way surrounds a part of the container 300, in particular a container head 310 in the form of a glass ampoule head, both axially in the direction of the delivery piston 270 and radially. The container 300 is thereby fixed within the rear part 230 of the interior 210 by means of the discharge piston 250 and the displacement means 500 in such a way that the risk of accidental opening of the container 300, for example due to a shaking movement of the device 100, is reduced. The type of arrangement shown is particularly suitable for displacement means 500, which are present as a compact, plastically deformable body, for example in the form of a hard fat, as a wax or in a pasty form.

In the embodiment shown, the device 100 is inserted into a discharge device 700 (not shown completely). The discharge device comprises an internal thread 710, which interacts positively and/or non-positively with an external thread 110 of the device 100 and thus connects the device 100 and the discharge device 700 to one another, and a plunger 720. In further embodiments, not shown, the device 100 and the discharge device 700 are not via a thread, but via a different type of connection can be connected in a positive and/or non-positive manner, in particular via a bayonet lock or a plug connection. The delivery piston 270 can be advanced axially in the interior 210 in the direction of the discharge piston 250 by means of the plunger 720 in the direction of the discharge piston 250.

Figure 2 shows the device Figure 1 , where compared to Figure 1 the delivery piston 270 is advanced in the direction of the discharge piston 250 by means of the plunger 720 of the discharge device 700 until contact between the container 300 and the delivery piston 270 has come about. The container 300, in particular the container head 310, was further received into the receptacle 271 of the delivery piston 270, while at the same time part of the displacement means 500 was pushed out of the receptacle 271. The position of the discharge piston 250 is compared to Figure 1 essentially unchanged. In the state of the device 100 shown, the distance between the delivery piston 270 and the discharge piston 250 essentially corresponds to the length of the container 300.

Figure 3 shows the device 100 from the Figures 1 and 2 , where compared to Figure 2 the delivery piston 270 is advanced further in the direction of the discharge piston 250 by means of the plunger 720 of the discharge device 700. By advancing the delivery piston 270, the structural integrity of the container 300 was destroyed, causing it to break down into a large number of container sections 300a and the monomer liquid 350 to leak from the interior of the container 300 into the rear part 230 of the interior 210. Some of the container sections 300a are at least partially enclosed by the displacement means 500, so that no monomer liquid 350 can be found between them. Monomer liquid 350 can be found between other container sections 300a that are not enclosed by the displacement means 500. The monomer liquid is arranged between the displacement means 500 and the discharge piston 250 within the rear part 230 of the interior 210.

Figure 4 shows the device 100 from the Figures 1 to 3 , where compared to Figure 3 the delivery piston 270 is advanced further in the direction of the discharge piston 250. Due to the resulting reduced distance from delivery piston 270 to discharge piston 250, the in Figure 3 The container sections 300a shown at least partially burst into further, smaller container sections 300a. The displacement means 500 encloses in comparison to Figure 3 a larger proportion of container sections 300a, whereby the monomer liquid 350 was displaced between these container sections 300a. The delivery piston 270 is pushed so far into the cartridge 200 that the monomer liquid 260 has penetrated into the conduit 260.

Figure 5 shows the device 100 from the Figures 1 to 4 , where compared to Figure 4 the delivery piston 270 is advanced further in the direction of the discharge piston 250. As a result of the propulsion, the container sections 300a are essentially completely enclosed by the displacement means 500 and the monomer liquid 350 is removed from the Figures 1 to 4 essentially completely conveyed via the conduit 260 from the rear part 230 into the front part 220 of the interior 210, whereby the bone cement powder 400 from the Figures 1 to 4 and the monomer liquid 350, a bone cement dough 450 was formed and provided in the front part 220 of the interior 210. In support of this, the bone cement powder 400 has an additive with which it is possible to introduce the monomer liquid 350 onto a base area of the front part 220 of the interior 210 and still achieve a complete distribution of the monomer liquid 350 in the bone cement powder 400. The pore disk 260 prevents the displacing agent 500 from being conveyed into the bone cement dough 450 Forming the bone cement dough 450 from monomer liquid 350 and bone cement powder 400, the volume of the original bone cement powder 400 increased due to swelling of the bone cement powder 400, as a result of which the plug 285 was partially expelled from the closure cap 281.

Figure 6 shows the device 100 from the Figures 1 to 5 , where compared to Figure 5 the delivery piston 270 together with the discharge piston 250 was advanced in the direction of the discharge opening 281 of the device 100. The advancement resulted in the bone cement dough 450 being partially discharged from the device 100. In order to carry out the dispensing in a targeted manner, the closure cap 281 is made of the Figures 1 to 5 replaced by a discharge snorkel 730 (only partially shown). In further embodiments, not shown, the bone cement dough is dispensed without a discharge snorkel 730, for example by simply removing the stopper 285 or the stopper 285 and the closure cap 281 from the Figures 1 to 5 discharged from the device 100.

Figure 7 shows a method 600 for providing a bone cement dough 450 from two starting components using the device 100 according to Figures 1 to 6 comprising method steps 610 to 630 and optionally 640.

In a step 610, the delivery piston 270 is pushed into the cartridge 200 in the direction of the discharge piston 250. If the distance between the delivery piston 270 and the discharge piston 250 decreases below a length of the container 300, it breaks into at least two container sections 300a, so that the monomer liquid 350 can flow out into the rear part 230 of the interior 210. The discharge piston 250 remains essentially in the same position within the interior 210.

In a step 620, continued advancement of the delivery piston 270 in the direction of the discharge piston 250 results in a compression of the initial container sections 300a. The compression can cause the initial container sections 300a to break down into smaller container sections 300a depending on the distance between the delivery piston 270 and the discharge piston 250.

At the latest when the volume of the rear part 230 of the interior 210 is reduced below the volume of the monomer liquid 350, the monomer liquid 350 begins to be pumped via the line means 260 into the front part 220 of the interior 210 while the bone cement dough 450 begins to form.

In a step 630, the monomer liquid between the container sections 300a is displaced by the displacement means 500 while the delivery piston 270 continues to advance in the direction of the discharge piston 250. For this purpose, the delivery piston 270 moves the displacement means 500 under pressure into a space between the container sections 300a, so that the displacement means 500 encloses the container sections 300a as much as possible and the monomer liquid 350 from the space between the container sections 300a via the line means 260 into the front part 220 of the interior 210 is funded.

For this purpose, the displacement means 500 has a volume which can, if possible, fill the entire space between the container sections 300a, so that as much as possible of the monomer liquid 350 can be conveyed into the front part 220 of the interior and is available there to form the bone cement dough.

In an optional step 640, the bone cement dough 450 is discharged from the device 100 through a discharge opening 280 in the front part 220 of the interior 210 by continued advancement 610 of the delivery piston 270. For this purpose, the delivery piston 270 overcomes a force holding the discharge piston 250, so that the delivery piston 270 and the discharge piston 250 are moved together in the direction of the discharge opening 280 within the interior 210 and the bone cement dough 450 is discharged.

As a result, the container 300 is opened, the monomer liquid 350 is conveyed as completely as possible into the front part 220 of the interior 210 with the cooperation of the displacement agent 500 and optionally the bone cement dough 450 provided thereby is discharged with a unidirectional linear movement of the delivery piston 270 in the interior 210 of the cartridge 200.

In order to provide a bone cement dough 450 with as few air inclusions as possible, the device 100 is preferably held during steps 610 to 630 so that the discharge piston 250 is arranged spatially above the delivery piston 270. Gas present there, such as air or a protective gas, in particular nitrogen or argon, is first conveyed from the rear part 230 of the interior 210 via the line means 260 into the front part 220 of the interior 210 before the monomer liquid 350 is conveyed sets in. In this way, gas inclusions in the bone cement powder 400 are displaced by the monomer liquid 350 and no further gas is introduced after the formation of the bone cement dough 450 has begun.

The advancement 610 of the delivery piston 270 can be done by manual force exerted by a user of the device 100. In a preferred embodiment of the method 600, for advancing 610, the device 100 is inserted into a discharge device 700 and the delivery piston 270 is advanced by actuating the discharge device 700, for example a discharge gun. This makes it easier for the user to use the device 100.

Reference symbols

100

contraption

110

External thread

200

hollow cylindrical cartridge

210

Interior of the cartridge

220

front part of the interior

230

rear part of the interior

250

Discharge piston

255

Discharge piston sealing rings

260

Conduit means

265

Pore disk

270

delivery piston

271

Recording

275

Sealing rings of the delivery piston

280

discharge opening

281

Cap

285

Plug

300

container

300a

Container sections

310

container head

350

Monomer liquid

400

Bone cement powder

450

Bone cement dough

500

Displacement agent

600

Method for providing a bone cement dough

610

Advance

620

Push together

630

Push away

700

Discharge facility

710

inner thread

720

Pestle

730

Discharge snorkel

Claims (15)

1. A device (100) for providing a bone cement paste (450) consisting of two starting components, comprising

   a hollow cylindrical cartridge (200) having an interior (210), a bone cement powder (400) as the first starting component being stored in a front part (220) of the interior (210) and a container (300) containing a monomer liquid (350) as the second starting component being stored in a rear part (230) of the interior (210),

   a dispensing plunger (250) which is axially movable in the interior (210) being arranged between the bone cement powder (400) and the container (300) and a delivery plunger (270) which is axially movable in the interior (210) being arranged on the side of the container (300) opposite the dispensing plunger (250), the rear part (230) and the front part (220) of the interior (210) being fluidically connected to one another via a conduit means (260), and, by advancing the delivery plunger (270) in the direction of the dispensing plunger (250), the container (300) being openable by disintegration into a plurality of container parts (300a), so that the monomer liquid (350) can flow into the rear part (230) of the interior (210),

   a volume-stable displacement means (500) being arranged in the rear part (230) of the interior (210), which displacement means is designed, by progressively advancing the delivery plunger (270) in the direction of the dispensing plunger (250), to surround the container parts (300a) with displacement of the monomer liquid between the container parts (300a), in order to convey the monomer liquid (350) from the rear part (230) into the front part (220) of the interior (210) via the conduit means (260),

   characterized in that

   the displacement means (500) comprises a hard fat and/or a wax having a melting point of at least 40°C.
2. A device (100) for providing a bone cement paste (450) consisting of two starting components, comprising

   a hollow cylindrical cartridge (200) having an interior (210), a bone cement powder (400) as the first starting component being stored in a front part (220) of the interior (210) and a container (300) containing a monomer liquid (350) as the second starting component being stored in a rear part (230) of the interior (210),

   a dispensing plunger (250) which is axially movable in the interior (210) being arranged between the bone cement powder (400) and the container (300) and a delivery plunger (270) which is axially movable in the interior (210) being arranged on the side of the container (300) opposite the dispensing plunger (250), the rear part (230) and the front part (220) of the interior (210) being fluidically connected to one another via a conduit means (260), and, by advancing the delivery plunger (270) in the direction of the dispensing plunger (250), the container (300) being openable by disintegration into a plurality of container parts (300a), so that the monomer liquid (350) can flow into the rear part (230) of the interior (210),

   a volume-stable displacement means (500) being arranged in the rear part (230) of the interior (210), which displacement means is designed, by progressively advancing the delivery plunger (270) in the direction of the dispensing plunger (250), to surround the container parts (300a) with displacement of the monomer liquid between the container parts (300a), in order to convey the monomer liquid (350) from the rear part (230) into the front part (220) of the interior (210) via the conduit means (260),

   characterized in that

   the displacement means (500) comprises a plurality of particles having a Shore A hardness of less than or equal to 80.
3. The device (100) according to claim 2, wherein the particles are spherical, in particular globular or ovoid.
4. The device (100) according to either claim 2 or claim 3, wherein the particles are formed from silicone rubber, natural rubber, polybutadiene-styrene rubber, and/or polyurethane-polyester rubber.
5. The device (100) according to any of claims 2 to 4, wherein the particles have a diameter in a range of 1 to 3.5 mm.
6. A device (100) for providing a bone cement paste (450) consisting of two starting components, comprising

   a hollow cylindrical cartridge (200) having an interior (210), a bone cement powder (400) as the first starting component being stored in a front part (220) of the interior (210) and a container (300) containing a monomer liquid (350) as the second starting component being stored in a rear part (230) of the interior (210),

   a dispensing plunger (250) which is axially movable in the interior (210) being arranged between the bone cement powder (400) and the container (300) and a delivery plunger (270) which is axially movable in the interior (210) being arranged on the side of the container (300) opposite the dispensing plunger (250), the rear part (230) and the front part (220) of the interior (210) being fluidically connected to one another via a conduit means (260), and, by advancing the delivery plunger (270) in the direction of the dispensing plunger (250), the container (300) being openable by disintegration into a plurality of container parts (300a), so that the monomer liquid (350) can flow into the rear part (230) of the interior (210),

   a volume-stable displacement means (500) being arranged in the rear part (230) of the interior (210), which displacement means is designed, by progressively advancing the delivery plunger (270) in the direction of the dispensing plunger (250), to surround the container parts (300a) with displacement of the monomer liquid between the container parts (300a), in order to convey the monomer liquid (350) from the rear part (230) into the front part (220) of the interior (210) via the conduit means (260),

   characterized in that

   the displacement means (500) comprises a paste containing a powdered solid and a liquid.
7. The device (100) according to claim 6, wherein the liquid comprises propane-1,2,3-triol and the solid comprises silica.
8. The device (100) according to claim 7, wherein the silica comprises pyrogenic silica and/or precipitated silica.
9. The device (100) according to any of the preceding claims, wherein the displacement means (500) occupies a displacement means volume which corresponds to at least a total volume of the container parts (300a).
10. The device (100) according to any of the preceding claims, wherein the displacement means (500) is arranged at least in part between the container (300) and the delivery plunger (270).
11. The device (100) according to any of the preceding claims, wherein the displacement means (500) is arranged at least in part radially around the container (300).
12. The device (100) according to claim 1, claim 2 or claim 6, wherein the displacement means (500) is substantially insoluble in the monomer liquid (350) at room temperature.
13. A method (600) for providing a bone cement paste (450) consisting of two starting components by means of a device (100) according to any of the preceding claims, comprising the following steps:

    a. advancing (610) the delivery plunger (270) in the direction of the dispensing plunger (250), with disintegration of the container (300) into a plurality of container parts (300a),

    b. pushing together (620) the container parts (300a) by continued advancement (610) of the delivery plunger (270),

    c. displacing (630) the monomer liquid (350) between the container parts (300a) by the displacement means (500) while conveying the monomer liquid (350) into the front part (220) of the interior (210) to form the bone cement dough (450).
14. The method (600) according to claim 13, wherein the device (100) is inserted into a dispensing apparatus (700) in order to advance (610) the delivery plunger (270).
15. The method (600) according to either claim 13 or claim 14, wherein the monomer liquid (350) is distributed in the bone cement powder (400) by means of a hydrophilic additive.

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