The invention relates to a device for the filling of a plurality of syringes according to the preamble of claim 1 and a method for the filling of a plurality of syringes according to the preamble of claim 6.

Vertebroplasty is an effective treatment option for osteoporotic v@rte.bxal fractures and vertebral body augmentation. Various injectable biαmaterials like Polymethylmethacrylate (PMMA) - a autopolymerising two-component system - or Calcium Phosphate (CaP) cements - a hydraulic cement hardening by the action of water as known e.g. from WO2004/000374 - are currently used as reinforcement materials together with appropriate cement injection instrumentations.

The device according to the invention is related to the instrumentation used for vertebroplasty. In order to perform vertebroplasty, a cement mixing device is needed to mix the cement components and an application device to inject the cement through a cannula over the pedicles into the vertebral body. An adequate mixing device for a surgical cement is described in PCT/WO03/084445. A possible injection syringe to be attached on a cannula is the subject International Patent Application PCT/CH04/00067, not yet published. An adequate cannula for injection of bone cements into vertebral bodies is described in WO0202033.

The success of the whole clinical procedure is time-dependent and handling steps by the surgical teams should be reduced to the minimum. After mixing of a cement, various working times including injection are available according to the chemical consistency of the used material before hardening of the cements. Due to hardening properties of the cements over time, injection-dependent handling steps (filling of injection syringes with mixed cement, injection of cement through cannula) are directly effected by the cement behavior and may alter the surgical procedure.

Two procedures are currently used to transfer a mixed cement into the vertebra: (1 ) the mixing device containing the mixed cement (e.g. cartridge, syringe) is connected directly to a cannula over an injection system (injection gun, tubing system, screw-in device); (2) the mixed cement contained in a mixing device (e.g. cartridge, syringe) is manually transferred to single portion syringes that are one after the other filled and connected to the cannula for cement injection. The last mentioned procedure (2) is preferred by the surgeon because it allows to apply the cement in small doses and to better control the injection force needed to augment the vertebra.

Besides the more difficult handling of these two procedures, they exhibit the following further drawbacks: a) with the current injection systems (injection gun, tubing system, screw-in device) it is very difficult to feel directly the pressure that is applied to the injection system and therefore to feel how the cement is injected into the bony structure of the vertebra. This may lead to an overpressure in the vertebral body followed by cement leakage out the vertebral body or to fat embolism due to over-displacement of the bone marrow inside the vertebral bone structure; and b) the mixing of the cement in a bowl and transfer to single syringes with a spatula is a "primitive" and messy procedure. Furthermore, PMMA cements are very odorous and therefore a closed system of cement mixing and dispensing is preferred.

On this point, the invention intends to provide remedial measures. The invention is based on the objective of providing a device allowing the use of single syringes for the application of cement into the vertebral body having the advantages of better feeling of the injection and of step by step injection. The aim of the invention is the increase of the handling properties of cement portioning after the mixing procedure.

The invention solves the posed problem with a device for the filling of a plurality of syringes that displays the features of claim 1 , as well as with a method for the filling of a plurality of syringes that displays the features of claim 6.

The main advantage of the device according to the invention is the time gain of the syringe filling (one shot = all syringes filled) instead of filling one by one with a spatula. Furthermore, the system is a closed system and does not expose the surgeon to evaporation of the odorous PMMA cement.

The present invention allows to simplify the last mentioned procedure (2) of mixed cement transfer into single syringes. In order to fill a cement into all single syringes at the same time and reduce the manual steps thereof, the device according to the invention is used for the dispensing of freshly mixed surgical cement into cement syringes. A varying number of little injection syringes is mounted on the device according o the invention by Luer lock or similar connection systems. The mixing device containing the freshly mixed cement is then connected to the dispensing device according to the invention by Luer lock or similar connection systems and by one shut the cement can be transferred into all syringes simultaneously. During this straight¬ forward procedure there is almost no time loss where the cement properties can alter and lead to intermediate hardening of the surgical cement.

Preferably, the injectable substance is a hardenable cement, particularly a surgical cement, e.g. a hydraulic cement or a two-component autopolymerising cement.

Furthermore, the discharge of the syringes may be effected sequentially. Therewith it is possible to prepare exact doses of surgical cement in the syringes.

The advantages achieved by the invention are essentially to be seen in the fact that, thanks to the device according to the invention:

- the surgical cement may be prepared in one mixing device; - exact doses of surgical cement may be prepared; - easy handling of the device; - the cleanness of the cement application may be improved; and - a rapid preparation of exact doses and application of surgical cement is possible.

In the preferred embodiment each adapting means is configured as male or female Luer-lock adapter. Therewith, common syringes with Luer-lock connectors may be used. Preferably, the dispensing member is realized as a longitudinal tube having a peripheral wall, a first end and a second end with a feed opening at the first end while the outlet openings are arranged axially spaced apart from each other and penetrating the peripheral wall transversely to the longitudinal axis.

In another embodiment the cavity within the dispensing member is provided with a discharge opening allowing prepared doses of injectable substances in each syringe to be discharged sequentially through the discharge opening.

In a further embodiment the dispensing member is provided with a separate valve for each outlet opening.

In yet another embodiment the device comprises a filling device, e.g. a mixing apparatus with a mixing chamber of a volume V or a large syringe with an injection volume V.

In a further embodiment the device additionally comprises a plurality of syringes being provided with an injection volume v whereby the ratio of v : V ranges between 0.2 and 0.5, preferably between 0.1 and 0.2. It is intended that the filling device has a cement volume V of 20ml, resp. 15-2OmI. However, this volume V may be divided in sub- volumes (e.g. V/2 & V/2) in order to use 2 syringes according to claim 8. It is intended to use small syringes with a cement volume v of 2ml each. The small volume v allows good feeling of the injection process and better control of the injected total volume by the surgeon.

In another embodiment the valves are configures as three-way valves. Therewith, the dispensing member offers the advantage that the syringes may be simultaneously or sequentially filled by feeding the injectable substance through the feed opening.

Additional advantageous embodiments of the invention are characterized in the subclaims.

The invention and additional configurations of the invention are explained in even more detail with reference to the partially schematic illustration of several embodiments. Shown are:

Fig. 1 a lateral view on one embodiment of the device according to the invention; and

Fig. 2 a lateral view on the embodiment of Fig. 1 during filling one of the syringes.

Fig. 1 and 2 show an embodiment of the device 1 where a tube like dispensing member 2 is provided with a longitudinal axis 9 and a coaxial cavity 3. The dispensing member 2 is realized through a longitudinal tube with a peripheral wall 12, whereby the cavity 3 is provided with a feed opening 4 at the first end 10 of the dispensing member 2 and a discharge opening 13 at the second end 11 of the dispensing member 2 as well as five outlet openings 5 being arranged sequentially and transversely to the longitudinal axis 9. The outlet openings 5 are arranged axially spaced apart from each other and penetrate the peripheral wall 12 transversely to the longitudinal axis. The feed opening 4 and the discharge opening 13 are arranged parallel to the longitudinal axis 9. Furthermore, the first end 10 of the dispensing member 2 is provided with first adapting means 6 for being joined e.g. with a mixing apparatus or another filling device 16. The first adapting means 6 are here configured as a female Luer-lock adapter. Another female Luer-lock adapter is situated at the second end 11 of the dispensing member 2. At each outlet opening 5 a second adapting means 7 is attached which is here configured as female Luer-lock adapter being engageable with a complementary third adapting means 7, e.g. a male Luer-lock adapter at the outlet of the syringes 14. Furthermore, the dispensing member 2 is provided with a valve 8 at each outlet opening 5 allowing each outlet opening 5 to be opened or closed separately.

Fig. 1 depicts all valves 8 at the outlet openings 5 in an open position and the syringes 14 with their pistons in their forward positions such allowing a simultaneous filling of the syringes 14 with a freshly mixed, injectable substance. The substance may be filled into the cavity 3 from filling device 16, e.g. another syringe which is connected to the first adapting means 6 at the first end 10 of the dispensing member 2. The discharge opening 13 is sealed by means of a sealing cap 17. An exemplary positioning of the valves for sequential filling of the syringes 14 is shown in Fig. 2. The two syringes 14 next to the feed opening 4 are already filled so that their corresponding valve 8a; 8b are in their open position allowing the substance being fed through the feed opening 4 to flow into the cavity 3 until the third valve 8c which is in a position allowing the substance only to flow through the third outlet opening 5 and subsequently into the connected third syringe 14.

Preferred materials for the dispensing member 2 are medical grade transparent polymers. The flow of the cements through the dispensing member 2 should be visible.

There is no cleaning of the dispensing member 2 required because it is a disposable part. After cement hardening it is not possible to reuse the device.

The discharge opening 13 has no specific meaning for this invention. A possible meaning could be used as a connection for a 6th syringe or as outlet for superfluous cement.

As the dispensing member 2 shown on the picture is already available on the market for haematological use, it can be imagined e.g. that the blood flow is given between opening 4 and opening 13. The side openings 5 could be used for drug delivery or to take blood samples. But this is not the intended use of this invention.