Vacuum mixing device for bone cement and method for mixing bone cement in said device

Abstract

The application relates to a vacuum mixing device for bone cement, where the monomer is pressed into a mixing container due to the surrounding vacuum and a gas volume present in the monomer container.

Claims

1. A mixing device for preparing bone cement, comprising: a mixing container; a monomer container attached to the mixing container and having first and second telescoping parts, the monomer container being moveable relative to the mixing container, wherein one of the first and second telescoping parts of the monomer container includes at least one catch hook and the other of the first and second telescoping parts of the monomer container includes at least one catch lug for engagement with the respective at least one catch hook such that the monomer container is locked in position relative to the mixing container.

2. The mixing device of claim 1, further comprising a pin for engagement with the monomer container, the pin being disengageable from and removable from the monomer container, wherein, when the pin is engaged with the monomer container, the first telescoping part of the monomer container does not move relative to the second telescoping part of the monomer container, and, upon removal of the pin, the first telescoping part of the monomer container moves relative to the second telescoping part of the monomer container.

3. The mixing device of claim 2, further comprising a monomer vial disposed in the monomer container, wherein upon removal of the pin, the monomer vial slides toward the mixing container and prevents reinsertion of the pin.

4. The mixing device of claim 2, further comprising a monomer vial disposed in the monomer container, wherein the pin includes a shaft and a deflectable tongue extending from the shaft, and wherein, when the pin is engaged with the monomer container, the monomer container rests on the tongue.

5. The mixing device of claim 2, further comprising a cannula attached to the monomer container and configured to pierce a monomer vial when the monomer vial is disposed in the monomer container, wherein when the pin is engaged with the monomer container and the monomer vial is disposed in the monomer container, the pin extends across the monomer container to separate the cannula from the monomer vial.

6. The mixing device of claim 2, wherein the mixing container is connectable to a vacuum source, the mixing device further comprising: a monomer vial disposed in the monomer container and filled at least partially with a volume of gas; and a cannula attached to the monomer container and configured to pierce the monomer vial, wherein when a vacuum is present in the mixing container and the piercing cannula pierces the monomer container, the monomer flows from the monomer container into the mixing container to at least a predefined fill level.

7. The mixing device of claim 6, wherein the at least 20% of the volume of the monomer container is filled with the volume of gas.

8. The mixing device of claim 6, wherein the at least 40% of the volume of the monomer container is filled with the volume of gas.

9. The mixing device of claim 1, wherein the monomer container includes a rod, the monomer container being attached to the mixing container via the rod.

10. The mixing device of claim 9, wherein the monomer container is configured to receive a monomer vial and a channel is disposed in the rod, and wherein monomer from the monomer vial is receivable in the mixing container through the rod.

11. The mixing device of claim 10, further comprising a cannula attached to the monomer container and received in a channel of the rod, the cannula being configured to pierce the monomer vial when the monomer vial is received in the monomer container.

12. The mixing device of claim 9, wherein the mixing container includes a plate, and wherein the rod of the monomer container is guided through the plate, the plate being detachable such that the plate is moveable to expel prepared bone cement.

13. A mixing device for preparing bone cement, comprising: a rod; a mixing container; a monomer container attached to the mixing container via the rod and including first and second telescoping parts, the monomer container and the rod being moveable relative to the mixing container; a cannula attached to the monomer container and having an end received in a channel of the rod, the cannula being configured to pierce a monomer vial when the monomer vial is disposed in the monomer container, wherein when the monomer vial is pierced, monomer flows via the cannula into the mixing container; and a pin for engagement with the monomer container, the pin being disengageable from and removable from the monomer container, wherein, when the pin is engaged with the monomer container, the first telescoping part of the monomer container does not move relative to the second telescoping part of the monomer container, and, upon removal of the pin, the first telescoping part of the monomer container moves relative to the second telescoping part of the monomer container.

14. The mixing device of claim 13, wherein the monomer vial is disposable between the first and second telescoping parts when the monomer vial is disposed in the monomer container and such that when the first telescoping part is telescoped relative to the second telescoping part from a first position to a second position with the monomer vial is disposed in the monomer container, the monomer vial is pushed onto the cannula.

15. The mixing device of claim 13, further comprising the monomer vial disposed in the monomer container, wherein the pin includes a shaft and a deflectable tongue extending from the shaft, and wherein, when the pin is engaged with the monomer container, the monomer container rests on the tongue.

16. The mixing device of claim 13, wherein when the pin is engaged with the monomer container and the monomer vial is disposed in the monomer container, the pin extends across the monomer container to separate the cannula from the monomer vial.

17. The mixing device of claim 13, wherein when the monomer vial is pierced, monomer flows via the cannula into the mixing container, wherein the mixing container includes a plate, and wherein the rod of the monomer container is guided through the plate, the plate being detachable such that the plate is moveable to expel prepared bone cement.

18. A mixing device for preparing bone cement, comprising: a mixing container; a monomer container attached to the mixing container and having first and second telescoping parts, the monomer container being moveable relative to the mixing container; and a pin for engagement with the monomer container, the pin being disengageable from and removable from the monomer container, wherein, when the pin is engaged with the monomer container, the first telescoping part of the monomer container is prevented from moving relative to the second telescoping part of the monomer container, and, upon removal of the pin, the first telescoping part of the monomer container slides relative to the second telescoping part of the monomer container.

19. A mixing device for preparing bone cement, comprising: a rod; a mixing container; a monomer container attached to the mixing container via the rod, the monomer container and the rod being moveable relative to the mixing container; and a cannula attached to the monomer container and having an end received in a channel of the rod, the cannula being configured to pierce a monomer vial when the monomer vial is disposed in the monomer container, wherein when the monomer vial is pierced, monomer flows via the cannula into the mixing container, wherein the mixing container includes a plate, and wherein the rod of the monomer container is guided through the plate, the plate being detachable such that the plate is moveable to expel prepared bone cement.

20. A mixing device for preparing bone cement, comprising: a rod; a mixing container; a monomer container attached to the mixing container via the rod, the monomer container and the rod being moveable relative to the mixing container; a monomer vial disposed in the monomer container; and a cannula attached to the monomer container and having an end received in a channel of the rod, the cannula being configured to pierce the monomer vial, wherein when the monomer vial is pierced, monomer flows via the cannula into the mixing container, wherein the mixing container is connectable to a vacuum source, the monomer vial being filled at least partially with a volume of gas, and wherein when a vacuum is present in the mixing container and the cannula pierces the monomer vial, the monomer flows from the monomer container into the mixing container to at least a predefined fill level.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described in more detail hereafter with reference to the drawings, these being FIG. 1 to FIG. 6, which show schematic views of embodiments of the invention.

(2) FIG. 1 to FIG. 4 show schematic views of an exemplary embodiment of a handle comprising a monomer container for a vacuum mixing device according to the invention.

(3) The entire vacuum mixing device will be described in more detail with reference to FIGS. 5 and 6.

DETAILED DESCRIPTION

(4) FIG. 1 is a schematic view of a monomer container 10 designed as a handle for a mixing blade (not shown). The monomer container 10 has a substantially cylindrical shape and comprises an actuating button 11 for releasing the monomer (not shown).

(5) In order to be able to press the actuating button 11, a safety bolt 12 having a handle 13, which forms a finger hole, is provided, which must be removed first.

(6) After the safety bolt 12 has been removed, the actuating button 11 can be pressed and the monomer flows, with a vacuum in the mixing container, into the mixing container (not shown) via a channel (not shown) that is embedded in the rod 6.

(7) FIG. 2 shows a sectional view of the monomer container 10 shown in FIG. 1 in a starting state, which is to say prior to use.

(8) The monomer container 10 comprises a lower housing part 15 and an upper housing part 16, which is also designed as the actuating button 11.

(9) The housing parts 15, 16 are used to accommodate a commercially available monomer vial 17 made of glass, which is sealed with a membrane 18.

(10) The monomer fills the monomer vial 17 approximately half in this exemplary embodiment. The fill level is predefined by the line 25.

(11) The monomer container 10 further comprises a cannula 19, which is connected to a channel 20 that is embedded in the rod 6.

(12) The cannula 19 and the membrane 18 of the monomer vial 17 are held apart from each other by the safety bolt 12 so that accidental actuation is not possible.

(13) The safety bolt 12 comprises a spring-loaded tongue so as to compensate for manufacturing tolerances of the monomer vial 17.

(14) As soon as the safety bolt 12 has been pulled out, the monomer vial 17 slides into a position in which the safety bolt 12 cannot be re-inserted.

(15) FIG. 3 shows a sectional view of the monomer container 10 after actuation.

(16) When the actuating button is pressed, the upper housing part 16 and the lower housing part 15 are pushed inside each other, whereby the monomer vial 17 is pushed onto the cannula 19 which pierces the membrane 18 so that the monomer can enter the mixing container (not shown) via the channel 20.

(17) Because of the air volume that is present above the fill level 25 and the vacuum that is present in the mixing container, the monomer is emptied to a low residual fill level, which is predefined by the position of the cannula 19.

(18) In order to define an exact position of the cannula 19 relative to the monomer vial 17, a ring 21 is provided in the lower housing part, with the monomer vial 17 being seated on this ring in the actuated state.

(19) FIG. 4 shows a detail view of the head of the monomer container shown in FIG. 3. The engagement of the monomer container will be described in more detail with reference to this figure.

(20) The upper housing part comprises catch hooks 22, which in the actuated state engage beneath catch lugs 23 of the lower housing part. For this purpose, the catch hooks 22 are beveled. It is not possible to pull them apart after engagement.

(21) So as to further increase the protection from manipulation, ribs 24 are provided on the lower housing part, which substantially prevent the use of a tool to push the catch hooks inward from beneath and thus return the monomer vial to the original position.

(22) FIG. 5 is a schematic view of the entire vacuum mixing device.

(23) The monomer container 10 is designed as a handle, which is connected via a rod 6 to a mixing blade (not shown).

(24) The mixing container 2 is preferably already prefilled with the powder.

(25) In order to ensure that the powder does not enter the rod 6, a filter, and more particularly a filter plate, is provided (not shown) at the lower end of the rod.

(26) When the vacuum mixing device 1 is used, a vacuum pump is connected to a vacuum connection 3 on the mixing container 2. A nonwoven fabric (not shown) that is embedded in the vacuum connection prevents bone cement from escaping.

(27) A withdrawal opening, which initially is still screwed to a base 5, is located at the bottom of the mixing container 2.

(28) The user (not shown) first connects the mixing container 2 to the vacuum.

(29) Then, he pulls the safety bolt and pushes the actuating button 11 of the monomer container.

(30) Because of the vacuum, the monomer (not shown) is displaced by the gas trapped in the monomer container 10 and flows via the rod 6 into the mixing container 2. To this end, the rod 6 comprises lateral openings above the mixing blades (not shown).

(31) The user then uses the monomer container 10 as a handle so as to move the mixing blades (not shown) in the mixing container 2 and thus prepare the bone cement.

(32) Thereafter, the user pulls the mixing blade all the way to the top and completely breaks off the rod 6 together with the monomer container 10 at a predetermined breaking point.

(33) Moreover, the user unscrews the base 5, whereby the withdrawal opening is uncovered.

(34) The mixing container 2 can now be utilized as a cartridge for a dosing gun (not shown). To this end, the cover 7 of the mixing container 2, in which the rod 6 is also guided, serves as a plunger. The cover 7 can, for this purpose, be connected to the remaining mixing container 2 so that it detaches at a particular force and can then be pushed forward. The cover can, for example, be pressed into a groove of the cylindrical housing of the mixing container 2.

(35) FIG. 6 shows a further perspective view of a vacuum mixing device 1. In this view, the base (5 in FIG. 5) has already been unscrewed, so that the withdrawal opening 4 is visible.

(36) The invention enables particularly simple and safe handling of bone cement.

(37) The invention is, of course, not limited to a combination of the aforedescribed characteristics, but a person skilled in the art can combine all the features to the extent this is expedient.

LIST OF REFERENCE NUMERALS

(38) 1 Vacuum mixing device

(39) 2 Mixing container

(40) 3 Vacuum connection

(41) 4 Withdrawal opening

(42) 5 Base

(43) 6 Rod

(44) 7 Cover

(45) 10 Monomer container

(46) 11 Actuating button

(47) 12 Safety bolt

(48) 13 Handle

(49) 14 Tongue

(50) 15 Lower housing part

(51) 16 Upper housing part

(52) 17 Monomer vial

(53) 18 Membrane

(54) 19 Cannula

(55) 20 Channel

(56) 21 Ring

(57) 22 Catch hook

(58) 23 Catch lug

(59) 24 Rib

(60) 25 Fill level