DEVICE AND METHOD FOR PREPARING BONE CEMENT PASTE

Abstract

A device for preparing a bone cement paste from two starting components, comprising a mixing unit comprising a hollow cylindrical cartridge with an interior, wherein a bone cement powder as a first starting component is stored in the interior, and a cartridge head which seals the interior in terms of fluid conduction at a proximal cartridge end, and a reservoir for a monomer liquid as a second starting component, comprising a conduit which connects the interior of the mixing unit to the reservoir in terms of fluid conduction, wherein the conduit extends through a cartridge head duct of the cartridge head of the mixing unit, and the conduit and the cartridge head duct form a first form closure.

Claims

1. A device for preparing a bone cement paste from two starting components, comprising: a mixing unit comprising a hollow cylindrical cartridge with an interior, wherein a bone cement powder as a first starting component is stored in the interior, and a cartridge head which seals the interior in terms of fluid conduction at a proximal cartridge end, and a reservoir for a monomer liquid as a second starting component, comprising a conduit connecting the interior of the mixing unit to the reservoir in terms of fluid conduction, wherein the conduit extends through a cartridge head duct of the cartridge head of the mixing unit, and the conduit and the cartridge head duct form a first form closure, wherein the reservoir comprises a reservoir container, in which at least one closed, in terms of fluid conduction, ampoule with an ampoule body and an ampoule head is arranged and the monomer liquid is stored in the ampoule, and a cavity in the region of the ampoule head, wherein the cavity is connected to the conduit in terms of fluid conduction and comprises a connection to the ampoule, wherein the ampoule head is arranged at least in regions within the connection, and the reservoir container comprises a deformable region at least in portions so that tilting of the ampoule about a pivot point against the connection is enabled, wherein the connection has a connection diameter which is adapted to the dimensions of the ampoule head such that the ampoule head can be opened, in terms of fluid conduction, when the ampoule is tilted about the pivot point against the connection, and wherein the reservoir comprises a connecting element to connect the reservoir to the mixing unit via a second form closure.

2. The device according to claim 1, wherein the first form closure and the second form closure are designed so as to be reversibly detachable from the mixing unit.

3. The device according to claim 1, wherein the pivot point, the first form closure, and the second form closure form the vertices of a triangle in a side view.

4. The device according to claim 1, wherein the second form closure has a shorter distance from the first form closure than the pivot point.

5. The device according to claim 1, wherein the first form closure, the second form closure, and the pivot point respectively lie on a straight line running parallel to a longitudinal axis of the cartridge, wherein the straight lines have a different straight-line distance from the longitudinal axis of the cartridge.

6. The device according to claim 1, wherein the mixing unit comprises a mixing tube arranged in a cartridge head passage of the cartridge head so as to be axially displaceable within the interior.

7. The device according to claim 6, wherein the second form closure is formed between the connecting element and the mixing tube.

8. The device according to claim 6, wherein a detachable mixing rod is arranged within the mixing tube.

9. The device according to claim 1, wherein a vacuum connection is arranged on the cartridge head, via which vacuum connection the interior can be connected, in terms of fluid conduction, to a negative-pressure source.

10. The device according to claim 1, wherein the conduit is a tube and/or a hose.

11. The device according to claim 10, wherein the conduit is axially displaceable in the cartridge head duct.

12. The device according to claim 10, wherein the conduit extends at least over 70% of an axial interior length of the interior.

13. The device according to claim 1, wherein the connecting element is a clasp.

14. The device according to claim 1, wherein a slider is arranged on the cartridge head in order to seal the cartridge head duct in terms of fluid conduction after removal of the conduit from the cartridge head duct.

15. A method for preparing a bone cement paste from two starting components by means of a device according to claim 1, comprising the steps of: a. opening, in terms of fluid conduction, the at least one ampoule by tilting the ampoule, stored in the reservoir container, about the pivot point against the connection, b. flowing of the monomer liquid from the at least one ampoule into the cavity, c. conveying the monomer liquid from the cavity into the interior via the conduit, d. detaching the second form closure, e. detaching the first form closure by pulling the conduit out of the cartridge head duct, f. sealing, in terms of fluid conduction, the cartridge head duct, g. mixing bone cement powder and monomer liquid.

Description

FIGURES

[0132] In the following, the invention is illustrated further, by way of example, by figures. The invention is not limited to the figures.

[0133] Shown are:

[0134] FIG. 1 a schematic longitudinal section of a device for preparing a bone cement paste, comprising a mixing unit and a reservoir with two ampoules filled with a monomer liquid,

[0135] FIG. 2 a perspective side view of a portion of the device of FIG. 1,

[0136] FIG. 3 the device of FIGS. 1 and 2, wherein a first form closure, a second form closure, and a pivot point are indicated,

[0137] FIG. 4 the device of FIGS. 1 to 3 given a fluid-conducting opening of the two ampoules,

[0138] FIG. 5 the device of FIGS. 1 to 4 during conveying of the monomer liquid into the mixing unit,

[0139] FIG. 6 the device of FIGS. 1 to 5, wherein the reservoir is separated from the mixing unit and the bone cement paste is prepared in the mixing unit,

[0140] FIG. 7 the device of FIGS. 1 to 6 during discharging of the bone cement paste from the mixing unit, and

[0141] FIG. 8 a flow chart of a method for preparing a bone cement paste.

DESCRIPTION OF THE FIGURES

[0142] FIG. 1 shows a schematic longitudinal section of a side view of an exemplary embodiment of a device 100 for preparing a bone cement paste from two starting components, in an initial state. The device 100 comprises a mixing unit 200 and a reservoir 300, which are connected to one another via two form closures (see also FIG. 3).

[0143] The mixing unit 200 is constructed like a tube and comprises a hollow cylindrical cartridge 210 with an interior 215, in which a bone cement powder 500 is stored as a first starting component. A proximal cartridge end 211 of the cartridge 210 is sealed in terms of fluid conduction with a reversibly detachable cartridge head 220, and a distal cartridge end 212 axially opposite the proximal cartridge end 211 is sealed in terms of fluid conduction with a dispensing piston 280 that can be displaced axially in the interior 215. In the shown embodiment of the device 100, the cartridge 210 and the cartridge head 220 are constructed from two components. In further embodiments (not shown), the cartridge 210 and the cartridge head 220 can be designed in one piece.

[0144] The cartridge head 220 comprises a cartridge head passage 226 through which a mixing tube 230 is introduced into the interior 215 so as to be axially movable. A screw thread 235 on the cartridge head 220 can fix the mixing tube 230 by means of a screwing movement such that the mixing tube 210 is no longer axially displaceable in the interior 215. Arranged within the mixing tube 230 is a mixing rod 240 which is detachably fastened to the mixing tube 230 via a detachable handle 250 at a proximal mixing tube end and is thus movable axially in the interior 215 together with the mixing tube 230. The handle 250 serves for simplified handling of the device 100 by a user in that it facilitates an axial movement of the mixing tube 230 together with the mixing rod 240 within the interior 215. At a distal mixing tube end facing toward the dispensing piston 280, the mixing tube 230 is equipped with a mixing element 245 in the form of a mixing disk which facilitates mixing of the bone cement paste in the interior 215 via an axial displacement of the mixing tube 230 within the interior 215.

[0145] A vacuum connection 260, formed like a tube, is attached to the cartridge head 220, via which vacuum connection the interior 215 can be connected in terms of fluid conduction to a negative-pressure source (not shown).

[0146] The reservoir 300 comprises a tubular reservoir container 320 in which two ampoules 330 are stored next to one another (only one of the ampoules 330 is visible in the shown view; the second ampoule 330 is stored next to the shown ampoule 330, behind the drawing plane). The ampoules 330 comprise an ampoule body 331, an ampoule head 332 facing toward the mixing unit 200, and an ampoule neck 333, which lies between ampoule body 331 and ampoule head 332 and acts as a predetermined breaking point for the ampoules 330. A monomer liquid 510 is stored in the ampoules 330 as a second starting component of the bone cement paste. The ampoule heads 332 of the ampoules 330 are arranged in portions in a connection 350 which connects a cavity 340 of the reservoir 300 to the ampoules 330. The connection 350 has a connection diameter 355 which is approximately 5% larger than a diameter of the ampoule heads, so that the connection 350 is fixed to the ampoule heads 332 against tilting within the drawing plane. The reservoir container 320 comprises a deformable region 325 in the region of a transition from connection 350 to ampoule body 331 in order to enable tilting of the ampoules 330, in particular of the ampoule heads 332, against the connection 350, wherein, in the shown embodiment, tilting is possible in the drawing plane.

[0147] Within the cavity 340, a filter element 345 is arranged in the reservoir 300 so that after the ampoules 330 have been opened in terms of fluid connection, fragments thereof cannot pass via the cavity 340 into the mixing unit 200 but rather are retained on the filter element 345.

[0148] The cavity 340 is connected in terms of fluid conduction via a conduit 310, in the form of a tube, to the interior 215 of the cartridge 210. For this purpose, the conduit 310 extends into the interior 215 via a cartridge head duct 225 of the cartridge head 220. The conduit extends approximately over 80% of an interior length 216 of the interior 215 so that, given the shown orientation of the device 100, the monomer liquid 510 can be conveyed directly into the bone cement powder 500 via the conduit 310 and has a sufficiently large distance from the vacuum connection 260 of the mixing unit so that the risk of the monomer liquid 510 being suctioned out of the conduit 310 via the vacuum connection 260 from the interior 215 is reduced.

[0149] The cartridge head duct 225 and the conduit 310 form a first form closure (cf. also FIG. 3) by which the mixing unit 200 and the reservoir 300 are connected to one another.

[0150] The reservoir 300 furthermore comprises a connecting element 360 in the form of a clasp (cf. also FIG. 2) which is arranged in a collar-like manner around the mixing tube 310 and forms a second form closure (cf. also FIG. 3) between mixing unit 200 and reservoir 300.

[0151] Arranged on the cartridge head 220 is a slider 270 which, after removal of the conduit 310 from the cartridge head duct 225, makes it possible to seal the cartridge head duct 225 in terms of fluid conduction via a displacement in the direction of the mixing tube 230.

[0152] FIG. 2 shows a schematic side view of a portion of the device 100 of FIG. 1. It is visible in FIG. 2 that the connecting element 360 is formed from two clasp notches 361 on an outer surface of the reservoir 300 and a clasp element 362 that can be detached from the two clasp notches 361. The clasp element comprises two protuberances (not shown) which can be inserted into the two clasp notches 261 so that the connecting element 360 can be reversibly closed in a collar-like manner around the mixing tube 230 in order to form the second form closure stably and securely between the mixing unit 200 and the reservoir 300. In the shown embodiment, the two clasp notches 361 and the two protuberances of the clasp element 362 are of triangular design, wherein an outer diameter of the protuberances substantially corresponds to a respective internal diameter of the clasp notches 261.

[0153] FIG. 3 shows the device 100 of FIGS. 1 and 2, wherein the first form closure 400, the second form closure 410, and a pivot point 420 about which, due to the deformable region 325, the ampoules 330 can be pressed by tilting against the connection (cf. FIG. 1) are indicated by filled circles.

[0154] In the shown side view of the device 100, the first form closure 400, the second form closure 410, and the pivot point 420 form a triangle (indicated by connecting lines between the filled circles). When the ampoules 330 are tilted about the pivot point 420 so that the ampoules 330, in particular the ampoule heads 332 (cf. FIG. 1), are pressed against the connection 350 (cf. FIG. 1), the force required in this case for the opening of the ampoules 330 in terms of fluid conduction is distributed to the first form closure 400 and the second form closure 410. An advantageous force distribution is achieved via the arrangement of the first form closure 400, the second form closure 410, and the pivot point 420 in the form of a triangle. In particular, the risk of the conduit 310 buckling or breaking off can thereby be reduced.

[0155] The first form closure 400, the second form closure 410, and the pivot point 420 are arranged relative to one another in such a way that the second form closure 410 has a shorter distance from the first form closure 400 than the pivot point 420. The pivot point 420 and the first form closure 400 are thus spaced farther apart from one another than the first form closure 400 and the second form closure 410. This ensures improved force distribution of the force, required during tilting about the pivot point 420 to open the ampoules 330, onto the two form closures 400, 410 and also, at the same time, ensures an optimally space-saving design of the device 100. The latter in particular facilitates the handling of the device 100 by a user.

[0156] The first form closure 400 lies on a straight line 401 running parallel to a longitudinal axis 213 of the cartridge 210, the second form closure 410 lies on a further straight line 411 running parallel to the longitudinal axis 213 of the cartridge 210, wherein the longitudinal axis 213 and the straight line 411 through the second form closure 410 are substantially congruent, and the pivot point lies on a further straight line 421 lying parallel to the longitudinal axis 213 of the cartridge 210, wherein the straight lines 401, 411, 421 all have a different straight-line distance from the longitudinal axis 213 of the cartridge 210. In the shown embodiment, the straight-line distance between the straight line 421 through the pivot point and the longitudinal axis 213 is greatest, followed by the straight-line distance between the straight line 401 through the first form closure 400, and the longitudinal axis 213. The different straight-line distances improve the force distribution of the force, required during tilting about the pivot point 420 to open the ampoules 330, onto the two form closures 400, 410, and at the same time allow an optimally space-saving design of the device 100. The latter in particular facilitates the handling of the device 100 by a user.

[0157] FIG. 4 shows the device 100 of FIGS. 1 to 3 with ampoules 330 tilted about the pivot point 420 (cf. FIG. 3). For this purpose, the reservoir container 320 was bent at the deformable region 325 so that the ampoule heads 332 were pressed against the connection 250 and the ampoules 330 were opened in terms of fluid conduction in the region of the ampoule necks (cf. FIG. 1). The monomer liquid 510 stored in the ampoules 330 opened in terms of fluid conduction has already partially flowed out of the ampoules 330 into the cavity 340. One of the two ampoule heads 332 is still arranged in portions in the connection 350, while the other of the two ampoule heads 332 has completely passed from the connection 350 into the cavity 3350. The ampoule head 332 that has passed completely into the cavity 340 was captured by the filter element 345 so that said ampoule head or fragments thereof cannot pass to or through the conduit 310. The cavity 340 is dimensioned in such a way that the ampoule heads 332 can be stored so as to be completely rotatable therein, so that monomer liquid 510 that is possibly still present in the ampoule head 332 after the opening of the ampoules 330 can flow out into the cavity 340. This has already occurred in FIG. 4, given the ampoule head 332 arranged completely in the cavity 340. In the shown embodiment of the device 100, the conduit, in particular a diameter of the conduit, is designed such that, due to its surface tension, the monomer liquid 510 cannot flow through the conduit 310 into the interior 215 of the cartridge 210 solely due to the force of gravity. The monomer liquid 510 flowed out of the ampoules 330 therefore collects in the cavity 340 until a user of the device 100 actively intervenes.

[0158] FIG. 5 shows the device 100 of FIGS. 1 to 4 during conveying of the monomer liquid 510 from the reservoir 300, in particular from the cavity 340 of the reservoir 300, into the interior 215 of the cartridge 210 of the mixing unit 200. The monomer liquid 510 has flowed substantially completely from the ampoules 330. In order to convey the monomer liquid 510 through the conduit 310, the vacuum connection 260 has been connected in terms of fluid conduction via a hose 450 to a negative-pressure source 460 in the form of a vacuum pump. Given an active negative-pressure source 460, this generates a negative pressure in the interior 215 and draws the monomer liquid 510 from the reservoir 300 into the mixing unit 200. Due to the axial extension of the conduit 310, the monomer liquid 510 is introduced directly into the bone cement powder 500, which reduces the risk of said monomer liquid being sucked through the vacuum connection 260 into the negative-pressure source 460. The negative pressure in the interior 215 is maintained at least until the monomer liquid 510 is substantially completely transferred into the mixing unit 200.

[0159] FIG. 6 shows the device 100 of FIGS. 1 to 5 with bone cement paste 520 prepared in the interior 215 and with reservoir 300 removed. In order to remove the reservoir 300, the first form closure 400 and the second form closure 410 between mixing unit 200 and reservoir 300 were detached (cf. FIGS. 1 to 5). In order to detach the second form closure 410, the clasp element 362 has been pulled out of the two clasp notches 261 (cf. FIG. 2), and in order to detach the first form closure 400, the conduit 310 has been pulled out of the cartridge head duct 225 (cf. FIGS. 1 to 5). Due to simpler handling, first the second form closure 410 and then the first form closure 400 (cf. FIG. 3) were detached. After removal of the reservoir 300, the cartridge head duct 225 was sealed in terms of fluid conduction by inserting the slider 270, so that the mixing of the bone cement paste 520 can take place with negative pressure applied in the interior 215.

[0160] In order to mix the starting components to prepare the bone cement paste 520, the mixing tube 230 together with the mixing element 245 was repeatedly axially moved up and down in the interior 215.

[0161] After the preparation of the bone cement paste 520, the previously fixed dispensing plunger 280 was detached so that the negative pressure of the negative-pressure source 460 acting in the interior 215 displaces the dispensing plunger 280 in the direction of the cartridge head 220. This allows collection of the bone cement paste 520 in the region of the cartridge head 220, which facilitates later dispensing of said bone cement paste from the device 100.

[0162] FIG. 7 shows the device 100 of FIGS. 1 to 6 during discharging of the bone cement paste 520. For this purpose, the mixing tube 230 was pulled out of the interior 215, through the cartridge head passage 226 until the mixing element 245 rests distally against the cartridge head 220. Furthermore, the detachable handle 250 together with the mixing rod 240 was removed from the mixing tube 230 (cf. FIGS. 1 to 6).

[0163] After removal of the mixing rod 240 from the mixing tube 230 (cf. FIGS. 1 to 6), the mixing tube 230 can serve as a fluid-conducting dispensing spout for the prepared bone cement paste 520. So that the mixing tube 230 is not unintentionally pushed back into the interior 215 during the discharging of the bone cement paste 520, it is reversibly fixed in the cartridge head passage 226 with the screw thread 235.

[0164] The bone cement paste 520 is dispensed from the device 100 by advancing the dispensing plunger 280 in the direction of the cartridge head 220. In order to facilitate the dispensing of the bone cement paste 520 for the user, the advancement of the dispensing plunger 280 happens with the aid of a dispensing aid 550 in the form of a dispensing gun (only partially shown).

[0165] FIG. 8 shows a flow chart of a method 600 for preparing a bone cement paste 520 from two starting components by means of a device 100 according to FIGS. 1 to 7, comprising steps 610 to 670 and preferably also step 680.

[0166] In a step 610, the at least one ampoule 330 in the reservoir 300 is opened in terms of fluid conduction by tilting about the pivot point 420 against the connection 350. The force required for this purpose is distributed onto the two form closures 400, 410 so that buckling of the conduit 310 is prevented.

[0167] In a step 620, the monomer liquid 510 flows from the at least one ampoule 330, opened in terms of fluid conduction in step 610, into the cavity 340 of the reservoir 300. The outflow of the monomer liquid 510 is preferably caused by the force of gravity. During the outflow of the monomer liquid 510, the ampoule head 332, further or other fragments of the at least one ampoule 332 are preferably retained by a filter element 345 in the cavity 340 so that it or they cannot penetrate into the conduit 310.

[0168] In a step 630, the monomer liquid 510 is conveyed from the cavity 340 via the conduit 310 into the interior 215 of the cartridge 210 and to the bone cement powder 500. In one embodiment, the force of gravity is utilized to convey the monomer liquid 510. In a further embodiment, a negative pressure applied in the interior 215 is used to convey the monomer liquid 510, which negative pressure is preferably provided via a negative-pressure source 460, for example a vacuum pump, connected to the vacuum connection 260. The conveying of the monomer liquid 510 preferably takes place directly into the bone cement powder 500, which can bring about a better mixing capability and, at the same time, reduces or prevents a risk of the monomer liquid 510 being sucked from the interior 215 via the vacuum connection 260 when negative pressure is applied.

[0169] In a step 640, detachment of the second form closure 410 takes place. The connecting element 360 is preferably a clasp so that the clasp element 362 is pulled out of the two clasp notches 361 to detach the second form closure 410.

[0170] In a step 650, detachment of the first form closure 400 takes place by pulling the conduit 310 out of the cartridge head duct 225.

[0171] By detaching 640, 650 the two form closures 400, 410, the reservoir 300 is separated from the mixing unit 200 and can be removed. This facilitates the handling of the mixing unit 200.

[0172] The two form closures 400, 410 can be detached in any order or even simultaneously. In a first alternative, step 640 takes place chronologically before step 650. In a second alternative, step 650 takes place chronologically before step 640.

[0173] Since the conduit 310 is preferably designed as a tube which extends in the interior 215 at least over 70% of the axial interior length 216 of the interior 215, the first alternative is preferred for reasons of simpler handling.

[0174] In a step 660, sealing of the cartridge head duct 225 in terms of fluid conduction takes place, in particular chronologically after the removal of the conduit 310 in step 650. This allows mixing of the bone cement powder 500 and monomer liquid 510 under negative pressure, which can reduce air inclusions in the bone cement paste 520.

[0175] The cartridge head duct 225 is preferably sealed by means of a slider 270.

[0176] In a step 670, a mixing of bone cement powder 500 and monomer liquid 510 takes place in the interior 215 of the cartridge 210 of the mixing unit 200. For this purpose, it is preferred that when negative pressure is applied, in the monomer liquid 510 is mixed with the bone cement powder 500 by means of the mixing rod 230 to form the bone cement paste 520. The mixing rod 240 is preferably detachably connected to the mixing tube 230 so that an axial movement of the mixing rod 240 is transmitted directly to the mixing tube 230. The mixing tube 230 is preferably equipped with the mixing element 245, preferably in the form of a mixing disk, in order to facilitate mixing. By mixing with applied negative pressure, air inclusions are reduced in the prepared bone cement paste 520.

[0177] In order to apply the prepared bone cement paste 520 from the device 100 at a desired location, it is preferred that, in an optional step 680, the mixing rod 240 is detached from the mixing tube 230, preferably by removing the handle 250, and is pulled out of the mixing tube 230. Preferably, before or after the removal of the mixing rod 240 from the mixing tube 230, the mixing tube 230 is pulled out of the cartridge head passage 226 so far that the mixing tube 230 can be used as a dispensing spout for the bone cement paste 520. By advancing the dispensing plunger 280 in the direction of the cartridge head 220, the bone cement paste 520 is discharged from the device 100 through the mixing tube 230. The advancement of the dispensing plunger 280 in the direction of the cartridge head 220 is preferably triggered with the aid of a dispensing aid 550, for example a dispensing gun. This facilitates the use of the device 100 by the user.

REFERENCE SIGNS

[0178] 100 Device [0179] 200 Mixing unit [0180] 210 Hollow cylindrical cartridge [0181] 211 Proximal cartridge end [0182] 212 Distal cartridge end [0183] 213 Longitudinal axis of the cartridge [0184] 215 Interior of the cartridge [0185] 216 Interior length [0186] 220 Cartridge head [0187] 225 Cartridge head duct [0188] 226 Cartridge head passage [0189] 230 Mixing tube [0190] 235 Screw thread [0191] 240 Mixing rod [0192] 245 Mixing element [0193] 250 Handle [0194] 260 Vacuum connection [0195] 270 Slider [0196] 280 Dispensing plunger [0197] 300 Reservoir [0198] 310 Conduit [0199] 320 Reservoir container [0200] 325 Deformable region [0201] 330 Ampoule [0202] 331 Ampoule body [0203] 332 Ampoule head [0204] 333 Ampoule neck [0205] 340 Cavity [0206] 345 Filter element [0207] 350 Connection [0208] 355 Connection diameter [0209] 360 Connecting element [0210] 361 Clasp notches [0211] 362 Clasp element [0212] 400 First form closure [0213] 401 Straight line through first form closure [0214] 410 Second form closure [0215] 411 Straight line through second form closure [0216] 420 Pivot point [0217] 421 Straight line through pivot point [0218] 450 Hose [0219] 460 Negative-pressure source [0220] 500 Bone cement powder [0221] 510 Monomer liquid [0222] 520 Bone cement paste [0223] 550 Dispensing aid [0224] 600 Method [0225] 610 Opening in terms of fluid conduction [0226] 620 Flowing [0227] 630 Conveying [0228] 640 Detaching of second form closure [0229] 650 Detaching of first form closure [0230] 660 Sealing in terms of fluid conduction [0231] 670 Mixing [0232] 680 Dispensing