WO2011083357A1

WO2011083357A1 - Devices, methods and systems for mixing and dispensing flowable material

Info

Publication number: WO2011083357A1
Application number: PCT/IB2010/000306
Authority: WO
Inventors: Anne-Laure Dorey; Cécile VIENNEY
Original assignee: Vexim Sas
Priority date: 2010-01-08
Filing date: 2010-01-08
Publication date: 2011-07-14
Also published as: TW201200115A

Abstract

Devices, methods and systems for mixing and dispensing flowable material are disclosed. The device may include a mixing container with a distal end, a proximal end, a first handle located at the proximal end and a tube portion having an opening at the distal end for receiving one or more components of flowable material, a piston with a bore for dispensing flowable material, a nut having two threaded portions with threads oriented in the same direction and a second handle fitting movably over the nut and engaged with the piston. The methods may be implemented by adding one or more flowable material components to the mixing container, connecting the mixing container to the nut, mixing the components to form flowable material and dispensing the flowable material via the piston by rotating the mixing container relative to a handle fitted movably over the nut and engaged with the piston.

Description

DEVICES, METHODS AND SYSTEMS FOR

MIXING AND DISPENSING FLOWABLE MATERIAL

FIELD

[0001] Devices, methods and systems for mixing and dispensing flowable material are described herein. In particular, a mixing and dispensing device that can, according to some embodiments, mix one or more components to create flowable material and dispense accurate, controlled amounts of the flowable material to an injection site is provided. More particularly, a mixing and dispensing device that accurately and controllably dispenses bone cement by moving a piston in a direction opposite to the direction of flow of the bone cement out of the device, and methods for improving bone cement dispensing accuracy, are described herein.

BACKGROUND

[0002] For many decades, physicians have widely-used biological, injectable materials to assist in securing bodily implants, such as hip and knee prosthetic devices, and remodeling bone defects. One type of such material commonly used in a variety of arthroplasty, vertebroplasty and, more recently, kyphoplasty procedures is bone cement. While the term "cement" implies a gluing function, bone cement primarily acts to fill small openings and voids in spongy bone skeleton and hollows on uneven surfaces between a prosthetic implant and the bone to prevent motion between the two. The term "bone cement" typically refers to a composition containing a copolymer powder based on methacrylate (PMMA), where the powder also contains an initiator (di-benzoyl peroxide), and a liquid monomer methylmethacrylate (MMA), where the liquid also contains the activator N,N-dimethyl-p- toluidine. The powder polymer comprises small particles of pre-polymerized polymethylmethacrylate. When mixed together, the powder polymer and liquid monomer polymerize and ultimately form "bone cement." [0003] Polymerization of bone cement occurs rapidly. Following the initial chemical reaction, bone cement viscosity changes from a runny liquid to a doughy state to, ultimately, a hard brittle material in a matter of minutes. Bone cement is thus typically applied within three to four minutes after the start of mixing, although this period may be extended by adding certain other chemicals. To that end, typically bone cement is most often prepared in the operating room during surgery and immediately applied to the targeted site.

[0004] Bone cement is conventionally formed in one apparatus and then transferred to a separate apparatus for delivery to an injection site. Transferring the bone cement from one device to another has drawbacks. First, those working with the bone cement are exposed to toxic monomer vapors emitted from the chemical reaction that occurs during polymerization. Also, transferring the bone cement to a separate container may result in spilling or contaminating the bone cement. Having to perform the transfer step also requires additional time and allows the bone cement to become more viscous and, thus, harder to deliver, i.e., requiring higher delivery pressure to force the cement through a delivery tube and injection needle. Mixing and dispensing the bone cement in a single device would eliminate these issues.

[0005] It is also beneficial to dispense the bone cement to the injection site in precise, highly- controlled amounts. Achieving an even layer of cement between the bone surface and the implant is highly important in surgical operations. Overfilling the injection site may cause bone cement to seep into the body, particularly the blood stream, and inflict serious and even fatal bodily harm. Thus, it is important that the flow of bone cement to an injection site stops the moment that the operator of the dispensing device stops activating the device. This is often difficult, however, because bone cement is a viscous material having a strong inertia effect such that when the dispensing system stops, a small amount of bone cement continues to flow to the injection site.

[0006] It is also important that the physician be able to observe the flow of the bone cement into the injection site. Constant image guidance during the operation is commonly achieved using x-ray (e.g., fluoroscopy). Images are captured at multiple angles and used throughout the procedure. To avoid exposure to x-ray radiation, a physician should be positioned remotely from the injection site and x-ray emissions. This may be accomplished using separate dispensing and injection devices connected by a long tubular conduit. [0007] While known prior art devices may address some of the aforementioned issues associated with mixing and dispensing bone cement, such devices are often large in size, structurally complex, involve long mixing and dispensing times and are more burdensome to operate. For example, U.S. Patent No. 6,547,432 to Coffeen et al. discloses a device for mixing and dispensing bone cement using a mixing phase, a transfer phase and a delivery phase. Coffeen et al. discloses a mechanism containing long threaded portions providing two-stage advancement in the same direction. The components of the bone cement are mixed and the bone cement is formed in a chamber. The mixture is then transferred from the chamber to a delivery cartridge by rotating a transfer mechanism to advance a piston through the chamber to urge the mixture into the delivery cartridge. The mixture is then delivered by further rotating the transfer mechanism to advance a plunger through the piston into the delivery cartridge in the same direction. One disadvantage of the mechanism used in Coffeen et al. is that it contains numerous components to manufacture and assemble and necessitates an elongated size because the advancement stages occur in the same direction. Such a mechanism also likely requires additional operator time to transfer the bone cement from the chamber to the piston.

[0008] It would therefore be advantageous to provide devices, methods and systems for mixing and dispensing a flowable material, such as bone cement, that are simple and cost- effective to manufacture and provide for easy and ergonomic operation. It would further be advantageous if such devices were at least partially reusable, compact in size and provided controlled dispensing of the flowable material to an injection site, with little (if any) residual flowable material left behind in the device following operation. It would also be advantageous if such devices were able to prevent the flow of any additional amount of flowable material to an injection site after a physician stops operating the device. It would be advantageous as well if such devices allowed operators to inject the flowable material remotely to avoid exposure to radiation, prevented exposure of harmful monomer fumes to operators and provided quick reduction of the mixing chamber to decrease risk of setting and increase dispensing time. SUMMARY

[0009] Embodiments of mixing and dispensing devices, as well as corresponding methods and systems, are described herein. These embodiments provide for improved mixing and dispensing of biological flowable materials, including without limitation bone cement. According to some embodiments, the disclosed devices and/or systems are simple and compact in size, cost-effective to manufacture and ergonomically advantageous in the operating room. For example, according to some embodiments, dispensing flowable material involves one continuous turning movement by the operator. The disclosed mixing and dispensing devices (and corresponding methods and systems) according to some embodiments can also be used remotely from the injection site to avoid radiation exposure to the device operator. Mixing and dispensing according to some embodiments may be performed in a single device to eliminate (i) the need to use separate mixing and dispensing devices, (ii) the time required to perform the transfer step and (iii) the risk of spilling and contaminating the flowable material during the transfer step.

[0010] Some embodiments described herein rapidly reduce the volume of a mixing chamber of the mixing and dispensing devices after mixing to provide an operator with more time for dispensing flowable material. Some embodiments described herein also provide for controlled dispensing of the flowable material to the injection site to avoid overfilling. Some embodiments are specifically directed to preventing the flow of any additional amount of flowable material to an injection site immediately after the operator has stopped the dispensing operation. Moreover, in some embodiments, screw threads may be employed to convert rotational movement into linear movement to activate embodiments of the mixing and dispensing devices and controllably dispense flowable material. Advantageously, the dispensing speed may be adjusted by using different thread pitches. In addition, the size of the bore used for dispensing flowable material may be varied to control dispensing and also prevent large amounts of flowable material from remaining in the device following operation.

[0011] Some embodiments of the device may comprise a plurality of components, and more particularly, may include four primary components for mixing and dispensing:

• a mixing container having a distal end, a proximal end, a first handle located at the proximal end and a tube portion having an opening at the distal end for receiving one or more components of the flowable material; a piston having a bore for dispensing the flowable material;

• a nut (which may also be referred to as an intermediate nut) having first and second threaded portions, wherein the threads of the first and second threaded portions are oriented in the same direction; and

• a second handle configured to fit movably over the nut and engage with the piston.

[0012] Some embodiments of the device may also include a mixing container that includes a threaded portion configured to engage with one of the first and second threaded portions of the nut. The piston may similarly have a threaded portion that engages with at least one of the first and second threaded portions of the nut. In some embodiments, the threads of the piston's threaded portion may be oriented in the same direction as the threads of the mixing container's threaded portion. Moreover, the piston may have a plunger at its proximal end and a seal thereon, both of which may be sized to fit within the tube portion of the mixing container in sealing relationship. The mixing container and the nut may also rotate together in the same direction when the mixing container is at least substantially threaded with the nut.

[0013] The device according to some embodiments may include a translation stop that prevents linear movement between the nut and the second handle and/or a rotation stop that prevents rotational movement between the piston and the second handle.

[0014] In some embodiments, the mixing container and the nut may be configured to rotate within the second handle relative to the second handle and rotate about the piston relative to the piston. Rotating the mixing container while holding the second handle substantially stationary may cause the piston to translate linearly within the mixing container toward the proximal end of the mixing container. Furthermore, rotating the mixing container while holding the second handle substantially stationary may cause the nut to rotate with the mixing container and linearly move the piston relative to the nut toward the proximal end of the mixing container. As a result of such movement of the piston into the mixing container, the flowable material in the mixing container may be displaced from the mixing container into the bore of the piston and flow through the bore in a direction opposite to the direction of translation of the piston. In some embodiments, the device may include a breakable pin that prevents movement between the nut and the second handle before the dispensing operation. Some device embodiments may also include a plug insertable into the piston's bore. The plug may extend through the piston's bore to further support an agitator positioned movably on the plug within the mixing container for improved mixing of the flowable material. In some embodiments of the mixing and dispensing device, the preferred flowable material is bone cement.

[0015] In some embodiments of the device, the mixing container and the nut may move together linearly between a first position and a second position relative to the second handle after the mixing container is at least substantially threaded with the nut. In certain embodiments, moving the mixing container and the nut together linearly relative to the second handle from the second position to the first position substantially prevents the flow of additional flowable material to an injection site after the dispensing operation has been stopped. The nut, in particular, may contain multiple components, including a sleeve having one of the first and second threaded portions and being movable between the first position and the second position relative to the second handle, and a tube fitting movably within the sleeve and containing the other of the first and second threaded portions. According to some embodiments, moving the sleeve from the second position to the first position substantially prevents the flow of additional flowable material to an injection site after the dispensing operation has been stopped. Certain device aspects include moving the sleeve from the first position to the second position by moving the mixing container in a linear direction toward the distal end of the second handle. Furthermore, in some embodiments, the sleeve may be moved automatically from the second position to the first position by an elastic force.

[0016] Other device embodiments for mixing and dispensing flowable material may include a mixing container having a distal end, a proximal end, a first handle located at the proximal end and a tube portion having an opening at the distal end for receiving one or more components of the flowable material, a piston having a bore for dispensing the flowable material, a nut having a sleeve, a tube and first and second threaded portions, wherein the sleeve contains one of the first and second threaded portions and the tube contains the other, the threads of the first and second threaded portions being oriented in the same direction, and a second handle fitting movably over the nut and engaged with the piston. In some embodiments, moving the sleeve between the first position and the second position relative to the second handle and the tube substantially prevents the flow of additional flowable material to an injection site after the dispensing operation has been stopped. [0017] Embodiments of a mixing container well suited for mixing and dispensing flowable material are also described herein. The mixing container may comprise a substantially cylindrical body having a distal end and a proximal end. In some embodiments, a handle may be located toward the proximal end for rotating the mixing container. The mixing container, according to some embodiments, may include a threaded portion. In some embodiments, the threaded portion may be located toward the distal end for threading the mixing container into another body having corresponding threads. The substantially cylindrical body of the mixing container, according to some embodiments, may include a hollowed-out portion that extends from the distal end toward the proximal end. Furthermore, the threaded portion may be located on the outside surface of the mixing container, the inside surface of a hollowed-out portion of the mixing container or both, depending on the desired configurations and/or application. Moreover, in some embodiments, the handle may contain one or more recesses for gripping the mixing container. In some embodiments, the threaded portion may extend along the substantially cylindrical body from the distal end toward the proximal end. Some embodiments of the mixing container may include a groove that traverses the threaded portion helically. The groove may be configured in a variety of different ways depending on the embodiment. For example, the groove may have a square, triangular or trapezoidal shape. Furthermore, the threaded portion, according to some embodiments, may comprise screw threads, wherein the screw threads have relatively large thread pitch or relatively small thread pitch.

[0018] Embodiments of a piston for mixing and dispensing flowable material are also described herein. The piston may include, according to some embodiments, a substantially cylindrical shaft having a proximal end and a distal end. In some embodiments, a plunger- shaped portion may be located toward the proximal end of the substantially cylindrical shaft. The plunger-shaped portion may, additionally, in some embodiments, have a channel containing a seal. According to some embodiments, the plunger-shaped portion may be funnel-shaped. In some embodiments, a threaded portion may also be located on an external surface of the substantially cylindrical shaft. The threaded portion may be positioned toward the proximal end of the substantially cylindrical shaft in some embodiments. The threaded portion may extend along a portion of the shaft or the entire shaft. The threaded portion may further contain external screw threads extending helically along the substantially cylindrical shaft. In some embodiments, the threads of the threaded portion may have relatively small thread pitch or relatively large thread pitch. Moreover, the threads of the threaded portion may be single, double or triple start and/or may be right-handed or left-handed, depending on the desired functionality and/or application.

[0019] Some embodiments of the piston may also contain a bore extending through the substantially cylindrical shaft. In some embodiments, the bore may extend through the entire length of the piston along the central axis of the piston. In some embodiments, the bore is suited particularly well for dispensing flowable material. The bore may be substantially cylindrical, according to some embodiments, and have a cross-sectional area that is relatively small compared to the cross-sectional area of the substantially cylindrical shaft. In some embodiments, the piston may further include a channel extending in the axial direction along the external surface of the substantially cylindrical shaft. The channel may be engaged with, according to some embodiments, other bodies to hold the piston substantially stationary relative to other bodies. Some embodiments of the piston may include a connection tip located toward the distal end. The connection tip may be engaged with a tube, syringe or other device for delivering flowable material from the piston. In some embodiments, engagement means may include a press fit or luer-lock connection.

[0020] Embodiments of a nut for mixing and dispensing flowable material are also described herein. In some embodiments, the nut may include a substantially cylindrical main body having a distal end and a proximal end. The main body, according to some embodiments, may have one or more interior portions, wherein one interior portion may be formed by an internal cylinder positioned within the substantially cylindrical main body. Another interior portion, according to some embodiments, may be located within the internal cylinder. In some embodiments, the internal cylinder may contain a first threaded portion. Similarly, some embodiments of the nut may also contain a second threaded portion. The first threaded portion, according to some embodiments, may extend along at least a portion of the internal cylinder. The second threaded portion, in some embodiments, may extend along at least a portion of an interior surface of the nut. In some embodiments, the first threaded portion may include a ridge helically traversing an interior portion of the nut. The first threaded portion and/or the second threaded portion may contain screw threads in certain embodiments. Some embodiments of the nut may include the first threaded portion having threads oriented in the same direction as the threads contained on the second threaded portion. In some embodiments, the second threaded portion contains threads having small thread pitch relative to the thread pitch of threads contained in the first threaded portion. The threads of the first threaded portion and/or the second threaded portion may be single, double, or triple start, according to some embodiments, as well as right-handed and/or left-handed.

[0021] In some embodiments of the nut, the internal cylinder may extend from the distal end of the substantially cylindrical main body toward the proximal end. Moreover, the internal cylinder may form a hollow tube in some embodiments and have a proximal opening and a distal opening and extend through the entire length of the nut. The nut may further include a flange, according to some embodiments, having a channel for receiving another body.

[0022] In some embodiments, the nut may comprise an assembly of multiple components, including a sleeve, a tube, a spring (i.e., an elastic element) and an o-ring. The sleeve may contain one of the first and second threaded portions of the nut and the tube may contain the other, according to some embodiments. Furthermore, in certain preferred embodiments, the threads of the first and second threaded portions may be oriented in the same direction. The sleeve and the tube may be generally cylindrical in shape and the tube may be sized to fit movably within the sleeve. The sleeve and the tube, in some embodiments, may each have engagement means for engaging with each other. The sleeve preferably contains a channel, which may optionally contain one or more holes for receiving a breakable pin. In some embodiments, the tube may also be provided with an o-ring to form a sealing relationship between the outer surface of the tube and the inner surface of the sleeve.

[0023] Method aspects of the present disclosure, according to the some embodiments, may include mixing and dispensing flowable material by adding one or more components of the flowable material to a mixing container having a distal end and a proximal end, engaging a portion of the distal end of the mixing container with a preliminary assembly. The preliminary assembly may include a piston having a bore for dispensing flowable material, a nut having a first and second threaded portion, wherein the threads of the first and second threaded portions are oriented in the same direction and a handle fitting movably over the nut and engaged with the piston. The mixing container and preliminary assembly together may form a main assembly having a sealed cavity for mixing one or more components of the flowable material, wherein the method, according to some embodiments, may include moving the main assembly to sufficiently mix the one or more components to create the flowable material and dispensing the flowable material through the bore of the piston by rotating the mixing container relative to the handle. [0024] The method aspects disclosed herein may further, according to some embodiments, include at least substantially threading the mixing container with the nut after the flowable material is created to force the mixing container and nut to rotate together in the direction that the mixing container was threaded with the nut. Certain method embodiments may further comprise a mixing container having a threaded portion that engages with one of the threaded portions of the nut and/or a piston having a threaded portion that engages with one of the threaded portions of the nut, wherein the threads of the piston's threaded portion are oriented in the same direction as the threads of the mixing container's threaded portion. In certain method embodiments, the piston may have a plunger and a seal sized to fit within the tube portion of the mixing container in a sealing relationship.

[0025] According to some embodiments, the method of dispensing may include rotating the mixing container relative to the handle to cause the piston to translate linearly toward the proximal end of the mixing container. Similarly, some methods may involve rotating the mixing container relative to the handle to rotate the nut with the mixing container and linearly translate the piston relative to the nut toward the proximal end of the mixing container. In such embodiments, the flowable material in the sealed cavity of the main assembly is displaced from the sealed cavity into the bore of the piston and flows through the bore in a direction opposite to the direction of translation of the piston. In some method embodiments, a plug may be inserted into the piston's bore before mixing the one or more components of flowable material. The plug may be a rod extending at least substantially through the piston's bore, according to some embodiments. In addition, some embodiments may have an agitator positioned movably on the rod and within the sealed cavity to provide for improved mixing by agitating the one or more components of flowable material when the main assembly is moved. In some method embodiments of the mixing and dispensing device, the preferred flowable material is bone cement.

[0026] In some method embodiments, after the dispensing operation has been stopped, the mixing container may be rotated relative to the handle in a direction opposite to the direction of rotation used for dispensing the flowable material. In such embodiments, rotating the mixing container in the opposite direction substantially prevents the flow of additional flowable material to an injection site. Furthermore, the nut employed in some method embodiments may include a sleeve having one of the first and second threaded portions and being movable between a first position and a second position relative to the handle, and a tube fitting movably within the sleeve and containing the other of the first and second threaded portion. In some embodiments, moving the sleeve from the second position to the first position substantially prevents the flow of additional flowable material to an injection site after dispensing has stopped.

[0027] Some method aspects may also involve moving the mixing container and a sleeve of the nut in a linear direction from a first position to a second position, maintaining the mixing container and the sleeve in the second position while dispensing the flowable material and/or moving the mixing container and the sleeve from the second position to the first position immediately after dispensing, wherein moving the sleeve from the second position to the first position substantially prevents the flow of additional flowable material to an injection site after dispensing has stopped. In some embodiments, the mixing container and the sleeve may be moved automatically from the second position to the first position by an elastic force.

[0028] According to some embodiments, a system is provided which may include a mixing and dispensing device and a conduit for receiving the dispensed flowable material from the mixing and dispensing device and transporting the flowable material to an injection device for injection. In some embodiments, the mixing and dispensing device may be located remotely from the injection site during mixing, dispensing and injection of the flowable material. Furthermore, the mixing and dispensing device may include a mixing container with a distal end, a proximal end, a first handle located at the distal end and a tube/cylindrical portion with an opening at the proximal end for receiving one or more components of the flowable material, a piston with a bore for dispensing the flowable material, a nut having a first and second threaded portion, wherein the threads of the first and second threaded portions are oriented in the same direction, and a second handle fitting movably over the nut and engaged with the piston.

[0029] The foregoing and other features, aspects and advantages of the disclosed embodiments, along with the claimed embodiments themselves, will be more apparent from the accompanying figures, detailed description and claims. BRIEF DESCRIPTION OF THE FIGURES

[0030] FIG. 1 is a perspective view of a mixing and dispensing device according to some embodiments described herein.

[0031] FIG. 2 is a perspective view of a mixing container according to some embodiments described herein.

[0032] FIG. 3 is a perspective view of a piston according to some embodiments described herein.

[0033] FIG. 4 is a perspective view of a nut according to some embodiments described herein.

[0034] FIG. 5 is a perspective view of a handle (e.g., an outer handle) according to some embodiments described herein.

[0035] FIG. 6 is a cross-sectional, perspective view of a preliminary assembly having a translation stop and a rotation stop according to some embodiments described herein.

[0036] FIG. 7 is a cross-sectional, perspective view of a preliminary assembly having a breakable pin according to some embodiments described herein.

[0037] FIG. 8 is a perspective view of a mixing container receiving powder polymer and liquid monomer according to some embodiments described herein.

[0038] FIG. 9 is a cross-sectional, perspective view of a main assembly prior to or during the mixing operation according to some embodiments described herein.

[0039] FIG. 10 is a cross-sectional, perspective view of a main assembly having the mixing container at least substantially threaded with the nut according to some embodiments described herein.

[0040] FIG. 11 is a cross-sectional, perspective view of the main assembly during the dispensing operation according to some embodiments described herein.

[0041] FIG. 12 is a cross-sectional, perspective view of the main assembly according to some embodiments described herein. [0042] FIG. 13 is a perspective view of a sleeve of the nut according to some embodiments described herein.

[0043] FIG. 14 is a perspective view of a tube of the nut according to some embodiments described herein.

[0044] FIG. 15 is a perspective view of the nut according to some embodiments described herein.

[0045] FIG. 16 is a cross-sectional, perspective view of the nut according to some embodiments described herein.

[0046] FIG. 17 is a cross-sectional, perspective view of a preliminary assembly according to some embodiments described herein.

[0047] FIG. 18 is a cross-sectional, perspective view of a main assembly according to some embodiments described herein.

[0048] FIG. 19 is a cross-sectional, perspective view of a main assembly according to some embodiments described herein.

DETAILED DESCRIPTION

[0049] FIG. 1 shows an embodiment of a device 1 comprising a mixing container 2, piston 10, nut 20 and handle 30 according to the present invention. Any and all of the components of device 1 may be transparent to allow an operator to view the mixing and dispensing of flowable material within device 1. Alternatively, any and all of the components may be opaque. Device 1 may be any suitable size depending on the volume and delivery pressure requirements.

[0050] FIG. 2 shows an embodiment of mixing container 2 that is generally cylindrical in shape and may comprise any suitable material, including without limitation, plastics or metals, for accomplishing a required or desired functionality. Mixing container 2 has a distal end 3 (shown in FIG. 2) and a proximal end 4. In some embodiments, distal end 3 may have a handle 5. Handle 5 may be any suitable shape, including without limitation, a knob or a T- shaped handle, and may include recesses 9 (which may also be ribs or other protrusions) to aid in gripping. Mixing container 2 may also comprise a cylindrical portion 6 (e.g., "tube portion") and a threaded portion 7 located toward the proximal end 4. The threaded portion 7 may be an extension of tube portion 6. In some embodiments, tube portion 6 is preferably hollow. The extent to which tube portion 6 is hollow, however, is discretionary and depends on how large of a mixing container 2 is required or desired. Tube portion 6 may therefore have walls of one thickness or another, and the hollow portion of tube portion 6 may extend substantially to the distal end 3 of mixing container 2.

[0051] In some embodiments, the threaded portion 7, which is preferably formed toward the proximal end 4 of mixing container 2, may extend along tube portion 6 toward distal end 3 as needed. Threaded portion 7 may also comprise any known thread type or other helical or mating design that results in linear movement (e.g., rotational movement of threads). For example, FIG. 2 shows threaded portion 7 having a groove 8 rather than screw threads per se, wherein groove 8 traverses threaded portion 7 helically. Groove 8 (or any other threads contained on threaded portion 7) may be any suitable shape, including without limitation, square, triangular or trapezoidal and may be in the form of any suitable thread type, including without limitation, a sharp V, unified, Whitworth, square, acme, worm buttress, knuckle or dardelet.

[0052] Basic thread concepts are incorporated herein and will be understood by one of ordinary skill in the relevant art. Matched thread pairs are typically described as male and female, whether external or internal. For example, a conventional screw has external male threads and its match hole has internal female threads. Threaded portion 7 shown in FIG. 2 shows an external female thread formed by groove 8 that corresponds to an internal male thread formed by ridge 25 of threaded portion 50 of nut 20. (see FIG. 4). As used herein, the term "pitch" refers to the distance from the peak of one thread to the next. The pitch also relates to the number of threads per axial distance. Pitch is measured from the front edge of one thread to the front edge of the next thread. The pitch may be relatively large (i.e., a coarse thread) or relatively small (i.e., a fine thread). A larger pitch has fewer threads per axial distance than a small pitch, which as more threads per axial distance. As one having ordinary skill in the art will understand, the larger the pitch, the greater the linear movement per rotation. [0053] Groove 8 depicted in FIG. 2 shows a relatively large pitch, providing greater linear movement resulting from less rotational movement. Threads may also be right-handed (as shown in FIG. 2) or left-handed. Groove 8 shown in FIG. 2 is right-handed. The right- handed form of groove 8 will advance mixing container 2 into a threaded hole having a matching or corresponding grooved-pattern when turned clockwise. A left-handed form of groove 8 would advance mixing container 2 into a threaded hole having a matching or corresponding grooved-pattern when turned counterclockwise. Threads may also be single- start, double-start or triple-start. "Single-start," by way of example, refers to a single thread being wrapped around a shank, such that one turn advances the screw the width of one thread. FIG. 2 shows groove 8 as a "single-start."

[0054] FIG. 3 shows an embodiment of piston 10. Piston 10 is generally cylindrical in shape and may comprise any suitable material, including without limitation, plastics or metals for accomplishing the functionality thereof. Piston 10 includes shaft 11, proximal end 12 and distal end 13. Proximal end 12, according to some embodiments, comprises a plunger 14 having a channel 15. Plunger 14 is preferably funnel-shaped and converges into a central bore 17 located along the central axis of piston 10, as shown in FIGS. 6, 7 and 9-11. Channel 15 may receive an o-ring 48 {see FIGS. 1, 6, 7 and 9-11) or any other object suitable for providing a sealing relationship with an adjacent surface. The diameter of plunger 14 relative to the inner diameter of tube portion 6 of mixing container 2 may be such that when piston 10 is positioned within tube portion 6, o-ring 48 provides a sealing relationship between plunger 14 and the inside of tube portion 6 and plunger 14.

[0055] Piston 10 may have a threaded portion 16. Referring to FIG. 3, threaded portion 16 may be positioned toward proximal end 12 and may comprise, without limitation, external threads extended helically along shaft 11 {e.g., screw threads). Threaded portion 16 may extend along shaft 11 to the extent necessary for a particular application. FIG. 3 shows threaded portion 16 having threads with relatively small pitch (i.e., a fine thread), although the pitch may vary depending upon the requirements and needs of a particular application. In some embodiments, the pitch of the threads of threaded portion 16 may be relatively small to achieve slower linear advancement of piston 10 when rotated within nut 20, which may have corresponding threads for threaded engagement there between {see FIGS. 6, 7 and 9-11). As discussed above with respect to threaded portion 7, the threads of threaded portion 16 may comprise any suitable thread form and may be single-start, double-start or triple-start, for _J example. The threads of threaded portion 16 may be right-handed or left-handed. In some embodiments, the orientation of the threads of threaded portion 16 is the same orientation as the threads of threaded portion 7 of mixing container 2. For example, if the threads of threaded portion 7 are right-handed, the threads of threaded portion 16 will be right-handed. When threaded portions 7 and 16 have threads oriented in the same direction, device 1 provides for a compact mechanism that efficiently dispenses flowable material by moving piston 10 into mixing container 2 in a single continuous rotating motion.

[0056] Piston 10 also preferably includes bore 17 that extends axially through the entire length of piston 10, and preferably along the central axis of piston 10. Flowable material, including without limitation bone cement, may be dispensed through bore 17. Bore 17 may extend through the cylindrical center of piston 10 or be offset from the cylindrical center. Bore 17 may also be any suitable size, depending on the desired needs (e.g., pressure, flow of material therethrough). In some embodiments, as shown in FIG. 3, bore 17 may be relatively small in size to avoid wasting material by leaving large amounts of material in bore 17 after a dispensing operation. Furthermore, according to some embodiments, a plug 52 may be inserted in bore 17, as shown in FIG. 12. Such configurations are described below in more detail in the context of the entire assembly of device 1.

[0057] Piston 10 may also include a channel 19 extending axially along shaft 11 (see FIGS. 1, 6 and 1 1). Channel 19 may be used for receiving a rotation stop 42 (see FIGS. 6 and 11). As explained in more detail below, rotation stop 42 engages channel 19 and rotation stop hole 36 of handle 30 to prevent rotational movement between piston 10 and handle 30 relative to each other. In some embodiments, distal end 13 of piston 10 comprises a connection tip 18. Connection tip 18 may be used to connect a tube, syringe or other device to piston 10 for delivery of dispensed flowable material to an injection device and, ultimately, an injection site. Connection means may include without limitation threads, a press fit, a luer-lock connection or combinations thereof, for example.

[0058] FIG. 4 shows an embodiment of nut 20, hereinafter referred to as intermediate nut 20. Intermediate nut 20 may have a generally cylindrical shape and comprise any suitable material including without limitation plastics or metals for accomplishing the functionality of the element. According to some embodiments, intermediate nut 20 comprises a body 21 having a proximal end 22, a distal end 23 and a hollow interior. In some embodiments, the intermediate nut 20 may have an interior surface 51 , wherein at least a portion of the interior surface 51 has a threaded portion 50 comprising a ridge 25. In some embodiments, ridge 25 may helically traverse interior surface 51. Intermediate nut 20 may also have an internal cylinder 24 for receiving piston 10. In preferred embodiments, internal cylinder 24 contains a threaded portion 26 with threads that correspond to the threads of threaded portion 16 on piston 10. In some embodiments, ridge 25 may correspond to groove 8 in threaded portion 7 of mixing container 2. As a result, mixing container 2 may be advanced into intermediate nut 20 (or intermediate nut 20 may be advanced onto mixing container 2) by rotating mixing container 2 and intermediate nut 20 relative to each other.

[0059] It is noted that one of ordinary skill in the art will appreciate that threaded portions 7 and 50 are not limited to the structures illustrated in the figures (namely, groove 8 and ridge 25) but may also comprise more traditional screw threads. Indeed, a skilled artisan will understand that a variety of mechanical systems (e.g., matching screw threads or matching ridge/groove configuration) may be used to convert rotational movement into linear movement or force. A skilled artisan will also understand that varying the pitch or configuration of such mechanical systems will vary the rate of conversion of rotation to linear movement (e.g., a larger pitch will provide greater linear advancement per a single rotation).

[0060] Referring still to FIG. 4, internal cylinder 24 preferably originates at or adjacent distal end 23 within the interior of body 21 of intermediate nut 20. Internal cylinder 24 extends axially within body 21 from distal end 23 toward proximal end 22. Internal cylinder 24 preferably includes the threaded portion 26, which may extend along at least a portion of the interior of internal cylinder 24 as shown in FIG. 4 to the extent necessary for a particular application. FIG. 4 shows threaded portion 26 having threads with relatively small pitch (i.e., a fine thread), however any suitable thread pitch may of course be employed depending upon the application. The threads of threaded portion 26 may comprise any suitable thread form and may be single-start, double-start or triple-start, for example. The threads of threaded portion 26 may be right-handed or left-handed, male or female. In some embodiments, the threads of threaded portion 26 will match the threads of threaded portion 16 of piston 10 such that piston 10 and intermediate nut 20 are threadably engageable, as shown in FIGS. 6, 7 and 9-11. In some embodiments, the pitch of threaded portion 26 (and threaded portion 16) are small so as to achieve slower, more controlled linear advancement of piston 10 within internal cylinder structure 24 and, in turn, more controlled dispensing of flowable material from device 1, as explained more fully below. In some embodiments, the orientation of the threads of threaded portion 26 is the same as the orientation of the threads of threaded portions 7 and 50. For example, if the threads of threaded portions 7 and 50 are right-handed, the threads of threaded portion 26 will be right-handed. As explained more fully herein below, using threads oriented in the same direction provides for a compact mechanism that efficiently dispenses flowable material by moving piston 10 into mixing container 2 in a single continuous rotating motion.

[0061] As shown in FIG. 4, intermediate nut 20 may include a flange 27 with a channel 28. Flange 27 and channel 28 may receive one or more translation stops 41, as shown in FIGS. 6 and 1 1, to prevent intermediate nut 20 from moving linearly, (i.e., in the axial direction) relative to handle 30, to avoid separation between intermediate nut 20 and handle 30. Translation stop(s) 41 are preferably movable through channel 28 and therefore, at least in some embodiments, do not prevent intermediate nut 20 from rotating relative to handle 30. In some embodiments, intermediate nut 20 may also comprise a breakable pin hole 29 for receiving a breakable pin 43. (see FIGS. 7 and 9). Breakable pin 43 may act as a safety device for preventing rotation of intermediate nut 20 (and mixing container 2) relative to piston 10 and handle 30 absent a sufficient force to break pin 43. When the operator is ready to dispense, sufficient force to break pin 43 may be applied. Breakable pin 43 may be made from a variety of suitable materials, any one of which have favorable mechanical properties (i.e., an appropriate shear modulus) such that the pin will cleanly shear without plastic deformation when a sufficient amount of force is applied.

[0062] Furthermore, in some embodiments, intermediate nut 20 may alternatively have one or more individual holes (e.g., openings) instead of a single channel 28, for receiving one or more translation stops 41. In such embodiments, one or more translation stops 41 may be used to prevent both linear and rotation movement between intermediate nut 20 and handle 30. Furthermore, in such embodiments, it is possible for translation stop(s) 41 to perform dual functions. That is, one or more translation stops 41 may (i) prevent axial movement between intermediate nut 20 and handle 30 and also (ii) act as a breakable pin 43 to prevent rotational movement between intermediate nut 20 and handle 30.

[0063] FIG. 5 shows an embodiment of handle 30. Handle 30 is generally cylindrical in shape and may comprise any suitable material, including without limitation, plastics or metals. Handle 30 comprises a body 31 having a proximal end 32 and a distal end 33. Body 31 may also have gripping portions 34, which may be recesses or protrusions, one or more translation stop holes 35 and preferably include at least one rotation stop hole 36. Handle 30 may include a proximal opening 37 for receiving intermediate nut 20. FIG. 5 also shows that proximal opening 37 may have a ledge 38 that abuts flange 27 of intermediate nut 20. Handle 30 may also have a distal opening 39 (see FIGS. 6, 7, and 9-1 1) for receiving and rotabably supporting piston 10.

[0064] As shown in FIG. 6, a preliminary assembly 40 is provided according to some embodiments. Preliminary assembly 40 may comprise piston 10, intermediate nut 20 and handle 30. In some embodiments, threaded portion 16 of piston 10 matches threaded portion 26 of intermediate nut 20. Piston 10 may thus be threaded into internal cylinder 24 of intermediate nut 20. Piston 10 may be fully threaded into internal cylinder 24 until plunger 14 contacts structure 24. (see FIG. 7). Handle 30 preferably slides over intermediate nut 20 such that ledge 38 abuts against flange 27. The fit between intermediate nut 20 and handle 30 may be a close contact fit but not a press fit. The two parts, according to some embodiments, move relative to each other when assembled.

[0065] One or more translation stop(s) 41 may be inserted into the one or more translation stop opening(s) 35 at proximal end 32 of handle 30. The translation stop(s) 41 may be press fitted into hole(s) 35 to prevent stop(s) 41 from falling out of device 1. Translation stop(s) 41 may extend into channel 28 of intermediate nut 20, as shown in FIG. 6. In some embodiments, translation stop(s) 41 may be freely movable within channel 28. Translation stop(s) 41, although shown as uniform cylinders, may be any suitable shape. Translation stop(s) 41 may also be of any suitable material to provide sufficient rigidness and not plastically deform under stress. When translation stop(s) 41 are serving also as a breakable pin, the material used may be one that has an appropriate shear modulus to withstand a certain amount of force but cleanly shear once the applied force surpasses a certain value. With translation stop(s) 41 in place, intermediate nut 20 and handle 30 are no longer able to move linearly relative to each other.

[0066] A rotation stop 42 may be inserted into rotation stop hole 36 at distal end 33 of handle 30 until so that extends into channel 19 of piston 10. Rotation stop 42 is preferably inserted after piston 10 is threaded (preferably fully threaded) into internal cylinder 24 of intermediate nut 20. Otherwise, rotation stop 42 may stop piston 10 from rotating and prevent full insertion of piston 10 into internal cylinder 24. Rotation stop 42 is preferably made of a suitable material to withstand breakage during operation, so as to prevent piston 10 from rotating relative to handle 30. Suitable materials for rotation stop 42 may include without limitation plastics or metals. FIG. 6 shows the rotation stop 42 as a cylinder; however, rotation stop 42 may be any suitable shape as long as it performs the requisite function of preventing rotation of piston 10 relative to handle 30. Rotation stop 42 may also have a tapered tip, as shown in FIG. 6.

[0067] FIG. 7 shows another embodiment of the mixing and dispensing device 1. In this embodiment, a breakable pin 43 is inserted into breakable pin opening 44 {see FIG. 10) of handle 30 and breakable pin hole 29 {see FIG. 10) of intermediate nut 20. As explained above, breakable pin 43 may be made of any suitable material that has an appropriate shear modulus to cleanly break when an applied force reaches a certain value. Breakable pin 43 preferably fits snugly {e.g., a press fit) into either or both of breakable pin hole 44 of handle 30 and breakable pin hole 29 of intermediate nut 20 to prevent breakable pin 43 from falling out of device 1. The purpose of breakable pin 43, according to some embodiments, is to prevent intermediate nut 20 from rotating relative to the handle 30 any time before dispensing. Once pin 43 is broken, intermediate nut 20 may rotate relative to handle 30. According to some embodiments, while pin 43 is shown as being positioned toward the distal end of device 1, pin 43 may be placed anywhere on device 1, as long as pin 43 achieves its purpose and does not interfere with at least some and preferably all of the other structures or functions of device 1.

[0068] According to some embodiments, mixing and dispensing device 1 may operate as follows. Mixing container 2 may be filled with appropriate components for making flowable material for injection into an injection area {e.g., site), as shown in FIG. 8. For illustration purposes only, and without intending to limit the scope of this disclosure, the following method aspects will hereinafter be described in terms of "bone cement." One of ordinary skill in the relevant art will understand, however, that any biological flowable material may be used with the embodiments described herein. The injection site is typically a location within the human body which generally requires percutaneous delivery. Bone cement is typically made from mixing together a powder polymer and a liquid monomer. The powder substance consists of small particles of pre-polymerized polymethylmethacrylate (PMMA). The liquid monomer consists of methylmethacrylate. When the two components are mixed, often in the presence of a catalyst, polymerization occurs and fuses the powder polymer particles into solid material. To this end, mixing container 2 may be filled with a powder polymer and liquid monomer. In some embodiments, a catalyst, or any other desired ingredient, may be added as well. Alternatively, mixing container 2 may be filled with premixed bone cement or mixing container 2 may contain only the powder polymer, thus requiring only the addition of the liquid monomer, or vice versa.

[0069] As shown in FIG. 9, mixing container 2 containing one or more components 45 (e.g., a powder polymer and liquid monomer combination) may then be connected to preliminary assembly 40 to form a main assembly 46 by engaging groove 8 of threaded portion 7 of mixing container 2 with ridge 25 of intermediate nut 20. Mixing container 2 is preferably rotated so that a sufficient amount of groove 8 is engaged with ridge 25 so that mixing container 2 is engaged with preliminary assembly 40 to prevent mixing container 2 and intermediate nut 20 from separating. The engagement between threaded portion 7 and threaded portion 50 is preferably sufficient to enable a sealing relationship between o-ring 48 of plunger 14 and the inside surface of tube portion 6 of mixing container 2. This sealing engagement preferably forms a sealed cavity 47 within which the one or more components 45 can be mixed and bone cement ultimately formed. In some embodiments, once there is sufficient sealing engagement between mixing container 2 and intermediate nut 20, the main assembly 46 may be manually moved (e.g., shaken, rotated or swirled) with sufficient force and for sufficient time to efficiently mix the one or more components 45 and thereby form the bone cement. Preferably, the main assembly 46 is sufficiently moved so that the powder polymer and liquid monomer components 45 begin to polymerize and homogenous bone cement is ultimately formed.

[0070] Following the mixing step, mixing container 2 is preferably further threaded (preferably the rest of the way) into intermediate nut 20 as shown in FIG. 10 (bone cement is not shown in FIG. 10). For example, contact between proximal end 4 of mixing container 2 and bottom face 49 of intermediate nut 20 may indicate that mixing container 2 is sufficiently (e.g., fully) threaded. At this point, according to some embodiments, mixing container 2 and intermediate nut 20 can only move together in the direction that mixing container 2 is threaded into the intermediate nut 20. For example, if groove 8 and ridge 25 have right- handed threads, the mixing container 2 and intermediate nut 20 will move together as a single unit in a clockwise direction. If groove 8 and ridge 25 have left-handed threads, the mixing container 2 and intermediate nut 20 move together as a single unit in the counterclockwise direction. Threading may be easily accomplished by holding handle 30 with one hand and turning mixing container 2 via handle 5 with the other hand. Notably, breakable pin 43 (see FIG. 9), or in some embodiments translation stop(s) 41, will prevent intermediate nut 20 from rotating relative to handle 30 while mixing container 2 is threaded into intermediate nut 20.

[0071] Threading mixing container 2 sufficiently more (e.g., the remaining distance) into intermediate nut 20 also reduces sealed cavity 47. In some embodiments, such as those illustrated herein, the pitch or helical angle of groove 8 and ridge 25 may be large, causing rapid advancement of mixing container 2 into intermediate nut 20 and, thus, rapidly reducing the volume of sealed cavity 47. In some embodiments, this is beneficial because bone cement viscosity increases with time. After the bone cement is formed in the mixing step, it is important to dispense the bone cement while the bone cement is still at a relatively low viscosity. A rapid reduction of the sealed cavity 47 allows more time for slower, controlled dispensing of the bone cement into the injection site.

[0072] After reducing sealed cavity 47, dispensing may begin, as shown in FIG. 11. At this stage, the operator may hold handle 30 (via gripping portions 34) in one hand and handle 5 of mixing container 2 in the other. In some embodiments, because mixing container 2 is sufficiently threaded (e.g., fully threaded or bottomed out) in intermediate nut 20, the two components will rotate together. Rotating mixing container 2 and intermediate nut 20 together, (i.e., in the direction that mixing container 2 was threaded into intermediate nut 20), while holding handle 30 rotationally stationary relative thereto, creates a torque between handle 30 and the mixing container 2/intermediate nut 20 assembly, according to some embodiments. This torque will apply a shear force to breakable pin 43 (shown in FIGS. 7 and 9). When sufficient force is applied, pin 43 (shown in FIGS. 7 and 9) will snap to allow the mixing container 2/intermediate nut 20 assembly to rotate relative to handle 30. Because of rotation stop 42, however, piston 10 remains stationary with handle 30 as intermediate nut 20 (via rotation of handle 5) rotates around it. When the threads of threaded portion 16 of piston 10 and threaded portion 26 of intermediate nut 20 are oriented in the same direction as the orientation of groove 8 and ridge 25 of mixing container 2 and intermediate nut 20 (e.g., when groove 8 and ridge 25 are right-handed and threaded portions 16 and 26 are also right- handed), piston 10 will move linearly into tube portion 6 of mixing container 2 where the bone cement is located. As a result, sealed cavity 47 is reduced even further and the bone cement is displaced out of sealed cavity 47 through bore 17 of piston 10 in the opposite direction. [0073] In some embodiments, by using threads with relatively small pitch for threaded portion 16 and 26, plunger 14 of piston 10 can be slowly and controllably advanced into sealed cavity 47 to dispense precise, deliberate amounts of bone cement through bore 17. The dispensing speed and force can be varied by the operator and/or the choice of threads used for threaded portions 16 and 26. Moreover, according to such embodiments, the operator need not change the direction of rotation of mixing container 2. The reduction of sealed cavity 47 and dispensing of the bone cement can be accomplished in one continuous motion.

[0074] In some embodiments, mixing and dispensing device 1 may further include a plug 52 that may be inserted into bore 17 of piston 10. Plug 52, according to some embodiments, may be in the form of a rod and extend partially or fully through bore 17 and into sealed cavity 47. FIG. 12 shows one possible configuration. Plug 52 may have a wide- variety of cross-sectional shapes, including without limitation circular, oval, square or triangular. In some embodiments, the cross- sectional shape of bore 17 and plug 52 may match. Furthermore, plug 52, regardless of cross-sectional shape, may fit tightly or loosely within bore 17. To this end, plug 52 may be movable in bore 17 in some embodiments or, in other embodiments, substantially stationary. Where plug 52 fits tightly within bore 17, plug 52 may serve as an obstruction to prevent the leakage of any flowable material before and/or during the mixing process from the bore 17. In some embodiments, plug 52 may be any suitable material, including without limitation plastics or metals, and may also be rigid and/or flexible in nature. Plug 52 may be inserted into bore 17 as part of preliminary assembly 40 before connection of the mixing container 2, according to some embodiments. Plug 52 may also be inserted into bore 17 as part of the main assembly 46 after mixing container 2 and preliminary assembly 40 are connected.

[0075] Some embodiments disclose an agitator 53 which may be positioned on plug 52. FIG. 12 also shows an example of this configuration. Agitator 53 may be any suitable size but preferably sized to fit within the hollowed portion of tube portion 6. Agitator 53 may be any suitable shape, including without limitation star-shaped, circular, oval or square. Agitator 53 may also, in some embodiments, be made from any suitable material, including without limitation plastics or metals. Agitator 53 is preferably positioned on plug 52 before the main assembly 46 is formed (i.e., before the mixing container 2 is connected to the preliminary assembly 40). When mixing container 2 is connected to preliminary assembly 40 to form main assembly 46, according to some embodiments, agitator 53 may be positioned on plug 52 so as to be within sealed cavity 47 with the powder polymer and liquid monomer combination 45. Agitator 53 may be positioned loosely or tightly on plug 52. In those embodiments where agitator 53 is positioned loosely (e.g., movably), agitator 53 may move along plug 52 within the sealed cavity 47. Thus, according to such embodiments, when the main assembly 46 is moved (e.g., shaken, rotated, swirled, etc.), the agitator 53 is caused to move along plug 52. Advantageously, movement of agitator 53 (e.g., back and forth) within sealed cavity 47 leads to improved mixing of the powder polymer and liquid monomer combination 45 and quicker formation of the flowable material (e.g., bone cement).

[0076] Another aspect of some embodiments of the present invention is directed to overcoming the inertia effect inherent in flowing bone cement to prevent additional amounts of cement from being delivered to an injection site when operation of the device ceases. Substantially preventing the flow of any additional bone cement to an injection site after a physician stops operating the device can be achieved by creating a cavity (e.g., a pocket, vacuum or pressure differential) between the bone cement remaining in the mixing chamber (e.g., within sealed cavity 47) and the proximal end 12 of the piston 10 (e.g., the plunger 14). According to embodiments described herein, this cavity can be created by moving the mixing container 2 in reverse, i.e., backing it out of the preliminary assembly 40. Because there is high pressure created within the mixing chamber during dispensing, moving the mixing container 2 in the opposite direction creates a sudden drop in pressure that forms a cavity within the bone cement adjacent to the proximal end 12 of the piston 10. The mixing container 2 can be moved backwardly out of the preliminary assembly 40 either manually or automatically, depending on the desired configuration and/or application.

[0077] The mixing container 2 can be manually reversed out of the preliminary assembly 40 by rotating the mixing container 2 in the direction opposite to the direction that the mixing container 2 was rotated into the preliminary assembly 40. For example, if the mixing container 2 was rotated clockwise (right-handed thread) into the preliminary assembly 40, then the operator would rotate the mixing container 2 counterclockwise to move the mixing container 2 out of the preliminary assembly 40. The amount of rotation may be, for example, 90 degrees or whatever amount is sufficient to create a cavity and prevent the continued flow of bone cement to the injection site. [0078] In some embodiments, the mixing container 2 may be reversed out of the preliminary assembly 40 automatically. FIGS. 13-20 show some exemplary embodiments according to the present invention that provide this "automatic" functionality. These exemplary embodiments may employ an intermediate nut 120 having multiple components, including without limitation a sleeve 130, tube 150, spring 160 and o-ring 170.

[0079] FIG. 13 shows an embodiment of sleeve 130 having a proximal end 131 and a distal end 132. Sleeve 130 may be generally cylindrical in shape with an outer surface 133 and an inner surface 134. In some embodiments, the outer surface 133 may have a threaded portion

135 and the inner surface 134 may be smooth to allow inserted objects to slide and/or rotate therein. While FIG. 13 shows threaded portion 135 traversing a majority of the length of sleeve 130, threaded portion 135 is not so limited and indeed may traverse only a small portion of the length of sleeve 130, according to some embodiments contemplated herein. Threaded portion 135 may also comprise any known thread type or other helical design. For example, FIG. 13 shows a preferred embodiment of threaded portion 135 having a groove

136 rather than screw threads per se. Groove 136 may be any suitable shape, including without limitation, square, triangular or trapezoidal. The pitch (explained above) of groove 136 may be relatively large (to provide greater linear movement per rotation) or relatively small (to provide less linear movement per rotation). The threads of threaded portion 135, including groove 136, may be oriented as right-handed or left-handed threads, depending on the desired configuration and/or application. Some embodiments of sleeve 130 may also have a channel 137 formed by a proximal wall 138 and distal wall 139. The dimensions of channel 137 may vary depending on the particular application and desired functionality. As explained in more detail below, channel 137 has a width w that may directly effect the formation of the cavity by dictating the amount of linear movement of the mixing container. In certain embodiments, channel 137 may also contain one or more holes 140. The distal end 132 of sleeve 130 may also have engagement means 141 that may be in the form of one or more castle teeth, as shown in FIG. 13, or any other shape or formation that achieves the desired engaging functionality.

[0080] FIG. 14 shows an embodiment of tube 150 having a proximal end 151 and a distal end 152. Tube 150 may be generally cylindrical in shape with an outer surface 153 and a piston tube interior 158 having an inner surface 154. In some embodiments, a majority of outer surface 153 may be substantially smooth to enable tube 150 to slide and/or rotate within other components, such as sleeve 130. In some embodiments, the inner surface 154 may have a threaded portion 155. Threaded portion 155 may traverse the entire length of tube 150 or some portion less than that, depending on the desired configuration and/or application. The threads of threaded portion 155 may be right-handed or left-handed, coarse or fine and comprise any known thread type or other helical design, according to various embodiments. The pitch of the threads of threaded portion 155 may be relatively large (to provide greater linear movement per rotation) or relatively small (to provide less linear movement per rotation). The tube 150 may also have a proximal channel 156, according to some embodiments. An o-ring 170 may be positioned in proximal channel 156 to provide a sealing relationship between outer surface 153 and inner surface 134 of sleeve 130, as shown in FIGS. 16-19. Some embodiments of the tube 150 may also have a distal channel 157 for receiving one or more translation stops 344. The distal end 152 may also have engagement means 159 that may be in the form of one or more notches, as shown in FIG. 14, or any other shape or formation that achieves the desired engaging functionality. In some embodiments, engagement means 141 and 159 may be complementary and engage with one another, e.g., the castle teeth on sleeve 130 may fit into the notches on tube 150. Furthermore, both engagement means 141 and 159 may be dimensioned such that engagement means 141 are able to move linearly relative to engagement means 159, or vice versa, and still maintain engagement with one another. As explained in more detail below, this allows the sleeve 130 to move between a "first position" and a "second position" relative to tube 150 to prevent the flow of additional flowable material to an injection site after the dispensing operation stops.

[0081] FIG. 15 shows an embodiment of the intermediate nut 120 comprising the sleeve 130, tube 150, spring 160 and o-ring 170 (not shown). FIG. 16 shows a cross-sectional view of the intermediate nut 120 shown in FIG. 15. According to some embodiments, the intermediate nut 120 may be assembled by first positioning spring 160 on tube 150 and placing o-ring 170 in proximal channel 156. In some embodiments, spring 160 may be made of an elastic material that is compressible or, in other embodiments, may be an elastic washer, a spring washer or a cup washer. The "tube 150/spring 160/o-ring 170" assembly may then be inserted into sleeve 130, as shown for example in FIGS. 15 and 16.

[0082] Referring to FIG. 17, intermediate nut 120 may then be assembled with other device components, including an outer handle 330 (hereinafter "handle") and a piston 370, to form preliminary assembly 240 according to the present invention. Handle 330 may be generally cylindrical in shape with a distal end 331 and a proximal end 332. Handle 330 may also have a distal opening 333 to provide for the insertion of piston 370 and a proximal opening 334 to allow for insertion of intermediate nut 120. Piston 370 may also be generally cylindrical in shape with a distal end 371 and a proximal end 372. Proximal end 372, according to some embodiments, may comprise a plunger (not shown). The plunger may include a funnel- shaped proximal end, which converges into a central bore and contains an o-ring that forms a sealing relationship with inner surface 154 of tube 150. In some embodiments, piston 370 may have a threaded portion 375, which may be positioned anywhere along piston 370, including along the entire length of piston 370, depending on the desired configuration and/or application. The threads of threaded portion 375 may have relatively small pitch (i.e., a fine thread) or relatively large pitch (i.e., a coarse thread). The threads of threaded portion 375 may be right-handed or left-handed. In some embodiments, the orientation of the threads of threaded portion 375 may be the same as the threads of threaded portion 135 of sleeve 130. When these threads are oriented in the same direction (e.g., both right-handed), the device provides for a compact mechanism that efficiently dispenses flowable material by moving piston 370 into tube 150 when the device is operated. Piston 370 may also include a bore 377 that extends axially through piston 370. Furthermore, as explained above with respect to piston 10, an axial channel (not shown) may be formed in piston 370 for receiving a rotation stop (not shown). The rotation stop may be inserted within a hole in handle 330 and extend into the axial channel on piston 370 to prevent piston 370 from rotating relative to the handle 330. The material and various configurations for the rotation stop may be those which are described above for rotation stop 42.

[0083] In some embodiments, the preliminary assembly 240 may also include a breakable pin (not shown). The breakable pin may be inserted into an opening in handle 330 (similar to opening 44 in handle 30) and an opening in intermediate nut 120 (similar to hole 29 in intermediate nut 20). The breakable pin may be made of any suitable material that has an appropriate shear modulus to cleanly break when an applied force reaches a certain value. The breakable pin preferably fits snugly (e.g., a press fit) into either or both of the openings in handle 330 and intermediate nut 120 to prevent the breakable pin from falling out. The breakable pin, as described above, may prevent intermediate nut 120 from rotating relative to the handle 330 prior to dispensing, e.g., during the mixing step and/or when the mixing chamber (e.g., sealed cavity 47) is being reduced. When the breakable pin is broken, intermediate nut 120 may rotate relative to handle 330. [0084] The preliminary assembly 240 may have one or more translation stops, according to some embodiments. First, one or more translation stops 344 may extend between handle 330 and tube 150 to allow tube 150 to rotate relative to handle 330 but prevent tube 150 from moving linearly relative to handle 330. The one or more stops 344 may be circular or any other shape that achieves the desired functionality. In some embodiments, one or more stops 344 may extend through hole 335 in handle 330 into distal channel 157 of tube 150, as shown in FIG. 17.

[0085] Preliminary assembly 240 may also include one or more translation stops 346 that extend between handle 330 and sleeve 130 to allow sleeve 130 to rotate relative to handle 330 but restrict the linear movement of sleeve 130 relative to handle 330. One or more stops 346 may extend through hole 336 in handle 330 and into channel 137 of sleeve 130, according to some embodiments and as shown in FIGS. 17-19. One or more stops 346 preferably slide within channel 137 to allow sleeve 130 to rotate relative to handle 330. Furthermore, the width w of channel 137 is preferably greater than the diameter or width of the one or more stops 346 to allow a degree of linear movement between sleeve 130 and handle 330 and tube 150. One or more stops 346 may be circular or any other shape that achieves the desired functionalities disclosed herein.

[0086] Notably, in some device embodiments, one or more stops 346 may also serve as the breakable pin, whereby the one or more stops 346 may be inserted into one or more holes 138 in channel 137, as shown in FIG. 17. To this end, the one or more stops 346 function to prevent linear movement and rotation between sleeve 130 and handle 330 prior to dispensing. When an appropriate force is applied, the one or more stops 346 will shear and allow sleeve 130 to move relative to handle 330.

[0087] FIG. 18 shows preliminary assembly 240 joined to a mixing container 110 according to some embodiments. Mixing container 110 is structurally similar to mixing container 2 discussed above, wherein embodiments thereof have a distal end 111, proximal end 112, handle 115, tube 1 16 and threaded portion 117. The location of threaded portion 117 on mixing container 1 10, however, is located on the inside of tube 1 16. In some embodiments, threaded portion 117 is preferably formed toward the distal end 1 1 1 of mixing container 110 and may extend along the inside of tube 116 to the extent needed. Like threaded portion 7 of mixing container 2, threaded portion 117 may comprise any known thread type or other helical design. In certain embodiments, threaded portion 117 may have a ridge 118, rather than screw threads per se, that corresponds with groove 136 of threaded portion 135 of sleeve 130. Ridge 118 may also traverse the threaded portion 1 17 helically. Ridge 118 may be any suitable shape but preferably one that corresponds with groove 136.

[0088] The embodiments described above with reference to FIGS. 13-18 generally operate as follows to automatically overcome the inertia effect of flowing bone cement when device operation is stopped. Flowable material (e.g. , bone cement) may first be formed using one or more components 45 according to the methods described above with reference to FIGS. 8 and 9. Mixing container 110 may specifically contain the one or more components 45. To mix the components, mixing container 110 may be connected to preliminary assembly 240 to form a main assembly 250 by engaging ridge 118 with groove 136. Mixing container 110 is preferably rotated so that a sufficient amount of ridge 118 is engaged with groove 136. In some embodiments, the ridge 118 may be threaded only partially into groove 136 to provide a mixing chamber within which the one or more components 45 can be mixed to form bone cement (see FIG. 9). As discussed above, some embodiments may contain an agitator 53 positioned on a plug 52 (see FIG. 12) and within the mixing chamber. Agitator 53 may be positioned loosely or tightly on the plug 52. In those embodiments where agitator 53 is positioned loosely (e.g., movably), agitator 53 may move along the plug 52 within the sealed cavity 247 when the main assembly 250 is moved (e.g., shaken, rotated or swirled). Advantageously, movement of agitator 53 (e.g., back and forth) within sealed cavity 247 leads to improved mixing of the powder polymer and liquid monomer combination 45 and quicker formation of the flowable material (e.g., bone cement).

[0089] After mixing, mixing container 110 is at least substantially threaded onto the sleeve 130. In some embodiments, mixing container 110 is fully threaded onto sleeve 130 so that distal end 1 11 contacts proximal wall 138 of channel 137, as shown in FIG. 18. According to some embodiments, when mixing container 110 is at least substantially threaded onto sleeve 130, sleeve 130 and tube 150 may project substantially into tube 116 and cause the bone cement to flow into tube 150, as shown in FIGS. 18 and 19.

[0090] FIG. 18 shows an embodiment of main assembly 250 ready to be operated, i.e., mixing container 110 is fully threaded with sleeve 130. Persons having ordinary skill in the relevant art will understand that when mixing container 110 is fully threaded onto sleeve 130, it cannot advance any further in a linear direction and thus forces sleeve 130 to rotate with it. As a result, in some embodiments, the breakable pin (e.g., one or more stops 346) is first broken by rotating mixing container 110 relative to handle 330 in the same direction that mixing container 110 was threaded onto sleeve 130. Tube 150 also rotates with sleeve 130 because of the engagement of engagement means 141 and 159.

[0091] After the breakable pin is broken, sleeve 130 is free to rotate relative to handle 330 and translate relative to handle 330 and tube 150 by a distance equal to the width w (e.g., 1.5 mm or 2mm) of channel 137. An example of this configuration is shown in FIG. 18 and may be referred to as the "first position." The "first position" is maintained due to spring 160 forcing sleeve 130 away from distal end 331 of handle 330. Sleeve 130 is held with handle 330 against the force of the spring 160, however, because of one or more stops 346 contacting distal wall 139 of channel 137. In some embodiments of the "first position," engagement means 141 and 159 are engaged to enable sleeve 130 to rotate piston 150 but are not fully mated, such that a gap 320 exists there between.

[0092] At this point, an operator may linearly move sleeve 130 by an amount no greater than that permitted by the width w (e.g., 1.5 mm or 2mm) of channel 137, and/or the dimensions of engagement means 141 or 159, by pushing mixing container 110 toward distal end 132 of sleeve 130. The new position of mixing container 110 may be referred to as the "second position." An example of this configuration is shown in FIG. 19. In some embodiments, sleeve 130 may be moved so as to completely eliminate gap 320 and fully mate engagement means 141 and 159. In some embodiments, sleeve 130 may be moved until one or more translation stops 346 contact proximal wall 138 and/or engagement means 141 and 159 are fully mated.

[0093] Following this linear movement, mixing container 110 may be rotated to dispense bone cement. Upon rotating mixing container 1 10, sleeve 130 and tube 150 also rotate. Because piston 370 cannot rotate due to rotation stop, it is forced to move linearly into tube 150 when tube 150 rotates due to threaded portion 155 being engaged with threaded portion 375. One skilled in the art will understand that when the orientation of the threads of threaded portions 155 and 375 is the same as that of the threads of threaded portions 135 and 117, piston 370 will advance into tube 150. As explained above, advancing piston 370 into tube 150 and/or tube 116 displaces the bone cement into bore 377 of piston 370 in a direction opposite to the direction that piston 370 is advancing. [0094] In the device embodiments described above, when an operator is finished dispensing bone cement, or otherwise wants to stop dispensing bone cement, the operator may simply release mixing container 1 10. Upon release, spring 160 automatically pushes sleeve 130 back the "first position" from the "second position." Mixing container 1 10 may also move with sleeve 130. This reverse movement of mixing container 1 10 and sleeve 130 caused by the spring 160 creates a cavity (e.g., a suction or vacuum) between the bone cement and proximal end 372 of the drilled piston 370, as explained above. The formation of this cavity immediately stops the flow of bone cement by creating a pressure differential causing bone cement to flow backwards into the cavity rather than continue to flow forward toward the injection site. Accordingly, automatically moving the mixing container 1 10 and sleeve 130 from the "first position" to the "second position" overcomes the inertia effect inherent in the flow of the bone cement and substantially prevents additional flowable material from flowing to injection site after the dispensing operation has been stopped.

[0095] According to some embodiments, a system for delivering the dispensed flowable material into the injection site may include: (i) the mixing and dispensing device 1, (ii) a suitable injection device, including without limitation a syringe, cannula or other injection device, for percutaneously delivering flowable material to a targeted injection site within the body and (iii) a conduit that connects device 1 and the suitable injection device. The conduit may, for example, be a tube of length sufficient to place the operator remotely away from the injection site to avoid exposure to x-ray radiation employed throughout the procedure.

[0096] Any and all articles, patents, patent applications, and publications referred to anywhere in the subject application are herein incorporated by reference in their entirety.

[0097] Example embodiments of the devices, systems and methods have been described herein. As noted elsewhere, these embodiments have been described for illustrative purposes only and are not limiting. Other embodiments are possible and are covered by the invention. Such embodiments will be apparent to persons of ordinary skill in the relevant art(s) based on the teachings contained herein. Thus, the breadth and scope of the disclosure should not be limited by any of the above-described embodiments but should be defined only in accordance with the following claims and their equivalents.

Claims

What is claimed is:

1. A device for mixing and dispensing flowable material, the device comprising: a mixing container having a distal end, a proximal end, a first handle located at the proximal end and a tube portion having an opening at the distal end for receiving one or more components of the flowable material; a piston having a bore for dispensing the flowable material; a nut having first and second threaded portions, wherein the threads of the first and second threaded portions are oriented in the same direction; and a second handle fitting movably over the nut and engaged with the piston.

2. The device of claim 1, wherein the mixing container further comprises a threaded portion having threads that mate with the threads of one of the first or second threaded portions of the nut.

3. The device of claim 1, wherein the piston further comprises a plunger having a seal and fitting within the tube portion of the mixing container.

4. The device of claim 2, wherein the piston further comprises a threaded portion having threads that mate with the threads of one of the first and second threaded portions of the nut, wherein such threads of the piston's threaded portion and the mixing container's threaded portion are oriented in the same direction.

5. The device of claim 2, wherein the mixing container and the nut rotate together in the same direction when the mixing container is at least substantially threaded with the nut.

6. The device of claim 1, wherein a translation stop prevents linear movement between the nut and the second handle.

7. The device of claim 1, wherein a rotation stop prevents rotational movement between the piston and the second handle.

8. The device of claim 1, wherein rotating the mixing container relative to the second handle results in linear movement of the piston within the mixing container toward the proximal end of the mixing container.

9. The device of claim 1, wherein rotating the mixing container relative to the second handle results in the rotation of the nut with the mixing container and linear movement of the piston relative to the nut toward the proximal end of the mixing container to cause the flowable material in the mixing container to be displaced from the mixing container into the bore of the piston and flow through the bore in a direction opposite to the direction of linear movement of the piston.

10. The device of claim 1, wherein the mixing container and nut rotate within the second handle relative to the second handle and rotate about the piston relative to the piston.

11. The device of claim 1, further comprising a breakable pin that prevents movement between the nut and the second handle.

12. The device of claim 1, further comprising a plug insertable into the bore of the piston.

13. The device of claim 12, wherein the plug is a rod extending through the piston's bore and into the tube portion of the mixing container to support an agitator positioned within the mixing container.

14. The device of claim 1, wherein the flowable material is bone cement.

15. The device of claim 1, wherein the mixing container and the nut may be linearly moved together between a first position and a second position relative to the second handle after the mixing container is at least substantially threaded with the nut.

16. The device of claim 15, wherein linearly moving the mixing container and the nut together relative to the second handle from the second position to the first position substantially prevents the flow of additional flowable material to an injection site after the dispensing operation has stopped.

17. The device of claim 1, the nut further comprising: a sleeve containing one of the first and second threaded portions, the sleeve being movable between a first position and a second position relative to the second handle; and a tube fitting movably within the sleeve and containing the other of the first and second threaded portions, wherein moving the sleeve from the second position to the first position substantially prevents the flow of additional flowable material to an injection site after the dispensing operation has been stopped.

18. The device of claim 17, wherein the sleeve is moved from the first position to the second position by moving the mixing container in a linear direction toward the distal end of the second handle.

19. The device of claim 17, wherein the sleeve is moved automatically from the second position to the first position by an elastic force.

20. A method for mixing and dispensing flowable material, the method comprising: adding one or more components of flowable material to a mixing container having a distal end and a proximal end; engaging a portion of the distal end of the mixing container with a preliminary assembly to form a main assembly, the main assembly providing a sealed cavity for mixing the one or more components of flowable material, the preliminary assembly including: a piston having a bore for dispensing the flowable material; a nut having a first and a second threaded portion, wherein the threads of the first and second threaded portions are oriented in the same direction; and a handle fitting movably over the nut and engaged with the piston; moving the main assembly to sufficiently mix the one or more components to create the flowable material; and dispensing the flowable material through the bore of the piston by rotating the mixing container relative to the handle.

21. The method of claim 20, wherein after the flowable material is created, the mixing container is threaded with the nut to force the mixing container and the nut to rotate together in the direction that the mixing container was threaded with the nut.

22. The method of claim 20, wherein the mixing container further comprises a threaded portion having threads that mate with the threads of one of the first and second threaded portions of the nut.

23. The method of claim 20, wherein the piston further comprises a plunger having a seal and fitting within the tube portion of the mixing container.

24. The method of claim 22, wherein the piston further comprises a threaded portion having threads that mate with the threads of one of the first and second threaded portions of the nut, wherein such threads of the piston's threaded portion and the mixing container's threaded portion are oriented in the same direction.

25. The method of claim 20, wherein rotating the mixing container relative to the handle results in linear movement of the piston toward the proximal end of the mixing container.

26. The method of claim 20, wherein rotating the mixing container relative to the handle results in rotation of the nut with the mixing container and linear movement of the piston toward the proximal end of the mixing container relative to the nut to cause the flowable material in the sealed cavity of the main assembly to be displaced from the sealed cavity into the bore of the piston and flow through the bore in a direction opposite to the direction of linear movement of the piston.

27. The method of claim 20, the method further comprising inserting a plug into the piston's bore before moving the main assembly to sufficiently mix the one or more components and subsequently removing the plug from the piston's bore.

28. The method of claim 27, wherein the plug is a rod extending at least substantially through the piston's bore.

29. The method of claim 20, wherein a rod is positioned in the piston's bore and extends into the sealed cavity to support an agitator movable along the rod for mixing the one or more components of the flowable material.

30. The method of claim 20, wherein the flowable material is bone cement.

31. The method of claim 20, the method further comprising rotating the mixing container relative to the handle after the dispensing operation has been stopped in a direction opposite to the direction of rotation used for dispensing the flowable material, wherein such rotation in the opposite direction prevents the flow of additional flowable material to an injection site.

32. The method of claim 20, wherein the nut further comprises: a sleeve containing one of the first and second threaded portions, the sleeve being movable between a first position and a second position relative to the handle; and a tube fitting movably within the sleeve and containing the other of the first and second threaded portions, wherein moving the sleeve from the second position to the first position substantially prevents the flow of additional flowable material to an injection site after the dispensing operation has been stopped.

The method of claim 20, the method further comprising: moving the mixing container and a sleeve of the nut in a linear direction from a first position to a second position; maintaining the mixing container and the sleeve in the second position while dispensing the flowable material; and moving the mixing container and the sleeve from the second position to the first position immediately after dispensing, wherein moving the sleeve from the second position to the first position substantially prevents the flow of additional flowable material to an injection site after the dispensing operation has been stopped.

The method of claim 33, wherein the mixing container and the sleeve are automatically from the second position to the first position by an elastic force.

A device for mixing and dispensing flowable material, the device comprising: a mixing container having a distal end, a proximal end, a first handle located at the proximal end and a tube portion having an opening at the distal end for receiving one or more components of the flowable material; a piston having a bore for dispensing the flowable material; a nut having a sleeve, a tube and first and second threaded portions, wherein the sleeve contains one of the first and second threaded portions and the tube contains the other, the threads of the first and second threaded portions being oriented in the same direction; and a second handle fitting movably over the nut and engaged with the piston, wherein the sleeve is movable between a first position and a second position relative to the second handle and the tube to substantially prevent the flow of additional flowable material to an injection site after the dispensing operation has been stopped.

36. A system for mixing and dispensing flowable material to an injection site, the system comprising: a mixing and dispensing device having a mixing container with a distal end, a proximal end, a first handle located at the proximal end and a tube portion with an opening at the distal end for receiving one or more components of flowable material, a piston with a bore for dispensing the flowable material, a nut having a first and a second threaded portion, wherein the threads of the first and second threaded portions are oriented in the same direction and a second handle fitting movably over the nut and engaged with the piston; and a conduit for receiving the flowable material dispensed from the mixing and dispensing device and transporting the flowable material to an injection device for injection.

37. The system of claim 36, wherein the mixing and dispensing device is located remotely from the injection site during mixing, dispensing and injection of the flowable material.