Device for mixing and injecting a composition, in particular a bone cement

Abstract

The invention relates to a device (100) for mixing and injecting a composition comprising: A reservoir (200) defining an internal chamber (204), and having a threaded opening (206); A piston assembly (600) comprising a threaded rod (610), a handle (650) and a piston head (630), the threaded rod (610): cooperating with the threaded opening (206) of the reservoir (200), having an open longitudinal internal channel (613); the piston head (630): being arranged in the internal chamber (204), having a through orifice (632) in continuity with the longitudinal internal channel; A mixing assembly (400) comprising a rod (410), a handle (450) and a mixing paddle (430), the rod (410) extending into the longitudinal internal channel of the threaded rod and into the through orifice of the piston head. piston, the mixing vane being arranged in the internal chamber (204). Figure for the abbreviation: Figure 1

Description

Title of the invention: Device for mixing and injecting a composition, in particular a bone cement Technical field of the invention

[0001] The present invention relates to a device for mixing and injecting a composition.

[0002] The object of the invention finds a particularly advantageous application in the field of bone surgery. The composition is a bone cement, specifically designed to ensure bone reconstruction. Previous technique

[0003] In many fields, it may be necessary for components, of the same phase or of different phases, to be mixed shortly before their use, for example because the composition obtained is unstable or because the composition obtained solidifies in a relatively short time.

[0004] In the building sector, for example, it is known to inject a composition into cracks in building walls in order to seal them. The composition, of the adhesive type, is generally fast-setting.

[0005] In the medical field, more specifically, it is known to use the injection of a composition, commonly called bone cement, into a bone to be treated in order to consolidate it. Surgical operations using this technique, such as vertebroplasty, vertebroplasty, and arthroplasty, are used to treat trauma, such as a bone fracture, or bone degradation due to disease. It is also known to use bone cement injections, for example, for the placement of implants, such as hip joints.

[0006] Conventional bone cements are composed of two components, generally a powder and a liquid, which are mixed to obtain a homogeneous composition in the form of a paste of varying thickness. Bone cements also set rapidly, generally within about fifteen minutes. It is therefore important to mix the components and inject the bone cement into the area to be treated within a relatively short time.

[0007] Some devices have been developed to allow for the mixing of the components constituting the bone cement and for others the injection of the bone cement obtained into the bone to be treated.

[0008] However, these devices have many drawbacks. Some devices prove to be complex to manufacture, particularly because they are composed of many parts to be assembled, and their use consequently requires The operator has to handle a great deal of equipment. Other devices are large and / or quite heavy, making them difficult to manipulate. Furthermore, the operator must handle several devices: one for mixing the components and another for injecting the bone cement. Handling these multiple devices in succession results in a significant loss of time, especially since the bone cement sets quickly. This also lengthens the operating time, and consequently the anesthesia time. The storage and recycling of these devices also presents a significant challenge.

[0009] Finally, not all devices on the market are suitable for bone cements of the pasty or even very pasty type, i.e., those with high viscosity. High viscosity is defined as a viscosity of at least 80 MPa·s. Some devices for mixing components are unable to mix components to obtain such a bone cement, while many devices for injecting bone cement are unable to inject such a very pasty bone cement. Presentation of the invention

[0010] The present invention aims to remedy the aforementioned drawbacks.

[0011] To this end, the present invention proposes a device for mixing and injecting a composition, referred to as the device, comprising: - a reservoir comprising a cylindrical wall, a first end and a second end, delimiting an internal chamber, and with a longitudinal axis,

[0012] the reservoir comprising, at its first end, a threaded opening,

[0013] the reservoir having, at its second end, an outlet orifice, - a piston assembly comprising a threaded rod, a handle located at one end of the threaded rod and a piston head located at the other end of the threaded rod,

[0014] the threaded rod: • cooperating with the threaded opening of the reservoir, • extending along the longitudinal axis of the reservoir, • comprising an internal longitudinal channel opening at its two longitudinal ends,

[0015] the piston head: • being arranged within the internal chamber of the tank, • having a cross-section with a shape complementary to the shape of the cross-section of the cylindrical wall of the tank, • comprising a through-hole in continuity with the internal channel of the threaded rod, • a mixing assembly comprising a shaft, a handle located at one end of the shaft and a mixing paddle located at the other end of the shaft,

[0016] the rod of the mixer assembly extending into the internal longitudinal channel of the threaded rod and into the through orifice of the piston head of the piston assembly,

[0017] the mixing paddle being arranged in the internal chamber of the tank.

[0018] The mixing assembly is designed to allow an operator to mix the components previously introduced into the internal chamber of the tank in order to obtain the composition. The piston assembly is designed to allow the operator to transfer the composition obtained in the internal chamber of the tank, after the components have been mixed by the mixing assembly, out of said internal chamber, via the outlet port. The mixing assembly is used during a phase known as the mixing phase. The piston assembly is used during a phase known as the injection phase. During the mixing phase, the piston head of the piston assembly is positioned at the first end of the tank. The operator manipulates only the handle of the mixing assembly, applying a translational movement to the assembly. This translational movement moves the mixing paddle within the tank's internal chamber, between the first and second ends. The movement of the mixing paddle within the internal chamber allows the components to be blended until the desired composition is achieved.

[0019] During the injection phase, the operator only manipulates the handle of the piston assembly and rotates it to screw the threaded rod into the tapped opening of the reservoir, causing the piston head to move in translation towards the second end of the reservoir, pushing the resulting composition through the outlet orifice of the reservoir.

[0020] The device according to the invention thus advantageously allows both the mixing of the components constituting the composition, via the mixing assembly, and on the other hand the injection of the composition, via the piston assembly.

[0021] Because the mixing assembly is nested within the piston assembly, the device according to the invention is compact, particularly for storage before use.

[0022] Due to its few constituent parts, the device according to the invention requires less handling by the operator and is easy to use. The operator This saves time compared to using existing devices, and allows the use of fast-setting cements.

[0023] Thanks to the engagement of the threaded rod of the piston assembly in the threaded opening of the reservoir, the device according to the invention advantageously allows the composition to be easily injected, even when it is of a pasty type, i.e. a composition with a high viscosity, without breaking.

[0024] The composition may be obtained, without limitation, from the mixture of: - a powder and a liquid, or - of two liquids, - of two gels, - of a gel and a liquid.

[0025] The device according to the invention can be used in many fields of application, such as, for example, the building sector. Thus, the device allows the mixing and injection of a composition into cracks in building walls in order to seal them.

[0026] The device according to the invention is particularly suitable for use in medical settings, especially for bone surgery procedures such as vertebroplasty, vertebroplasty, and arthroplasty, aimed at strengthening a bone or vertebra. The fact that the device can mix and inject a paste-like bone cement has the advantage of reducing operating time, and therefore anesthesia time, thus decreasing risks for patients. Furthermore, the use of a paste-like bone cement reduces the risk of bone cement leaching into the patient's body.

[0027] According to particular embodiments, the invention further meets the following characteristics, implemented separately or in each of their technically operative combinations.

[0028] In particular embodiments, to allow the introduction of components into the internal chamber of the tank, the tank is made in two removable parts, a first part comprising the threaded opening of the tank and a second part comprising the outlet orifice of the tank, the first part forming a cover for the second part.

[0029] In particular embodiments, to allow the introduction of the constituent components of the composition into the internal chamber of the tank, the tank has an orifice made in the cylindrical wall.

[0030] In particular embodiments, the stem of the mixing assembly is an elongated body, smooth on the outside, and has a cross-section whose shape is complementary to the shape of the cross-section of the longitudinal internal channel of the threaded stem of the piston assembly. The handle of the mixing assembly is fixed attached to the rod of the mixing assembly. The operator must then apply a translational movement, along the longitudinal axis, and a rotational movement, around the longitudinal axis, to the handle of the mixing assembly to move the mixing paddle in translation and rotation.

[0031] By "solidarity," it is understood that the parts are joined to each other by a connection allowing relative movement of one part with respect to the other. By "fixed solidarity," it is understood that the parts are mutually connected in a fixed manner, that is to say, relative movement between them is impossible.

[0032] In particular embodiments, the internal longitudinal channel of the threaded rod of the piston assembly has an internal helical rib. The rod of the mixing assembly is an elongated body with an external helical groove, said external helical groove cooperating with the internal helical rib of the internal longitudinal channel of the threaded rod of the piston assembly. The handle of the mixing assembly is integral with the rod of the mixing assembly. The operator then only needs to apply a translational movement, along the longitudinal axis, to the handle of the mixing assembly to move the mixing paddle of the mixing assembly in translation and rotation.The engagement of the helical groove of the rod in the helical rib of the internal longitudinal channel of the threaded rod causes the rod to translate and rotate, and consequently the mixing paddle in the tank to translate and rotate.

[0033] In particular embodiments, to prevent the mixing paddle from moving in the internal chamber of the tank during the injection phase, the mixing paddle is fixedly attached to the piston head during said injection phase.

[0034] In particular embodiments, to make the mixing paddle and the piston head fixedly joined, the mixing paddle of the mixing assembly includes a sleeve, and the piston head of the piston assembly includes a housing suitable for receiving the sleeve by fitting.

[0035] In particular embodiments, to prevent the mixing assembly rod from hindering the operator's movements during the injection phase, the mixing assembly rod is removable.

[0036] In particular embodiments, the mixing assembly rod has a thread at its second longitudinal end. The mixing paddle sleeve has a central tapped cavity. The thread in the rod and the tapped cavity in the central cavity cooperate. The mixing assembly rod can thus be unscrewed from the mixing paddle and extracted from the piston assembly and therefore from the device.

[0037] In particular embodiments, to prevent the mixing assembly's rod from hindering the operator's movements during the injection phase, the stem of the mixing assembly has a zone of weakness which can initiate the breakage of said stem.

[0038] In particular embodiments, to facilitate the operator's gripping of the device, the device includes a gripping element, such as a handle. In specific embodiments, said gripping element may be formed by two half-shells joined together, surrounding the reservoir at the level of its cylindrical wall. The first and second ends of the reservoir are not enclosed by the two half-shells. In particular embodiments, said gripping member may be formed by two half-shells assembled together, surrounding the reservoir, at least at the level of its first end, and a portion of the threaded rod of the piston assembly. Brief description of the figures

[0039] The invention will be better understood upon reading the following description, given by way of non-limiting example, and made with reference to the following figures:

[0040] Fig. 1 illustrates a cross-sectional view of an example of a device for mixing and injecting a composition according to the invention;

[0041] Fig. 2 represents two variants of an example of a reservoir of the device for mixing and injecting a composition;

[0042] Fig. 3 represents two further examples of the device's reservoir for mixing and injecting a composition;

[0043] Fig. 4 represents a perspective view of part of a piston assembly of the device for mixing and injecting a composition;

[0044] Fig. 5 illustrates a perspective view of an example of a piston head of the piston assembly of the device for mixing and injecting a composition;

[0045] Fig. 6 is a front view of the piston head of the piston assembly of the device for mixing and injecting a composition;

[0046] Fig. 7 is a perspective view of an example of a mixing assembly of the device for mixing and injecting a composition;

[0047] The [Fig.8] is a perspective view of part of a mixing assembly of the device for mixing and injecting a composition;

[0048] Fig. 9 represents a cross-sectional view of the device for mixing and injecting a composition from Fig. 1, during a mixing phase;

[0049] Fig. 10 represents a cross-sectional view of the device for mixing and injecting a composition of Fig. 1, prior to an injection phase;

[0050] Fig. 11 represents a cross-sectional view of the device for mixing and injecting a composition of Fig. 1, during the injection phase;

[0051] Fig. 12 represents a cross-sectional view of an alternative embodiment of the device for mixing and injecting a composition.

[0052] In these figures, identical numerical references from one figure to another designate identical or analogous elements. Furthermore, for reasons of clarity, the drawings are not to scale unless otherwise stated. Description of the implementation methods

[0053] The invention relates to a device for mixing and injecting a composition according to the invention.

[0054] In the remainder of the description, the device for mixing and injecting a composition will simply be referred to as device 100.

[0055] The invention is described in the particular context of one of its preferred fields of application in which the device 100 is intended to be used in a medical setting, in particular for bone surgery operations, such as cementoplasty, vertebroplasty, arthroplasty, in order to consolidate a bone or a vertebra.

[0056] The device according to the invention advantageously allows both the receiving of the constituent components of the desired composition, called bone cement, the mixing of said components in order to obtain the bone cement, and the injection of the bone cement.

[0057] Bone cement used during surgical operations is generally obtained, without limitation, from the mixture of a powder and a liquid.

[0058] In one embodiment, the powder is a polymethyl methacrylate (PMMA) powder and the liquid contains methyl methacrylate (MMA) molecules.

[0059] The bone cement resulting from the mixing process is generally in the form of a paste of varying thickness. The resulting bone cement exhibits suitable mechanical and chemical properties and is biocompatible.

[0060] The preparation of such a bone cement is within the capabilities of a person skilled in the art.

[0061] Fig. 1 illustrates an example of device 100 according to the invention.

[0062] The device 100 includes a reservoir 200.

[0063] The reservoir 200 has the shape of a hollow cylindrical body, preferably with a circular cross-section. The reservoir 200 comprises a cylindrical wall 203, a first end 201, a second end 202, and has a longitudinal axis Z. The reservoir 200 delimits an internal chamber 204 into which components can be introduced for mixing in order to form bone cement.

[0064] The reservoir 200 has, at its second end 202, an outlet orifice 207. The outlet orifice 207 is also in communication with the internal chamber 204 of the reservoir 200. Preferably, the reservoir 200 has, at its second end 202, a wall 205 comprising the outlet 207, as illustrated in [Fig. 1]. The outlet 207 may be equipped with a connector (not shown) suitable for cooperating with a complementary connector of another medical device, such as a trocar, cannula, or needle, to transfer the bone cement to the area to be treated. The connector may, for example, be of the Luer Lock type.

[0065] The outlet port 207 can be fitted with a cover (not shown) to prevent bone cement from flowing through the outlet port 207 during the mixing of the components in the internal chamber 204 of the tank 200.

[0066] The reservoir 200 has, at its first end 201, a threaded opening 206. The threading of the opening is internal, that is to say, it is made inside the opening. The threading of the opening is not shown in Figures 1, 9-11.

[0067] The threaded opening 206 is in communication with the internal chamber 204 of the reservoir 200. The threaded opening 206 is centered on the longitudinal axis Z of the reservoir 200. The threaded opening 206 can form all or part of the first end 201 of the tank 200. In the example in view a) of [Fig. 3], the tank 200 has, at its first end 201, a wall comprising the threaded opening 206. In the example in view b) of [Fig. 3], the threaded opening 206 is formed along the entire first end 201 of the tank 200. The threading of the opening is then carried out on an internal surface 209 of the cylindrical wall 203 of the tank 200.

[0068] The reservoir 200 can be made in one piece, as illustrated in views a) and b) of [Fig. 3]. Preferably, the reservoir 200 has an orifice 208 formed in the cylindrical wall 203 of the reservoir 200, for introducing the components into the internal chamber 204 of the reservoir 200. Said orifice 208 can be equipped with a connector (not shown) suitable for cooperating with a complementary connector of another medical device, such as a syringe or a funnel, for transferring the components constituting the bone cement into the internal chamber 204 of the reservoir 200. The connector can, for example, be of the Luer-Lock type. Port 208 can be fitted with a cover (not shown) to prevent bone cement from flowing through port 208 during the mixing of components in the internal chamber 204 of the tank 200.

[0069] The reservoir 200 can be made in two removable parts 210, 220, as illustrated in view a) of [Fig. 2], to allow the introduction of components into the internal chamber 204 of the reservoir 200. For example, a first part 210 may include the threaded opening 206 of the reservoir and a second part 220 may include the outlet 207 of the tank. The first part 210 can, for example, form a cover for the second part 220. The two parts 210, 220 are joined together by reversible connecting means, for example a threaded connection 230. The first part 210, respectively the second part 220, includes a thread, respectively a tapped hole, or vice versa, the thread and tapped hole cooperating so that the two parts 210, 220 can be assembled or disassembled. The reservoir 200, made of two removable parts 210, 220, may further include the orifice 208 formed in the cylindrical wall 203 of the reservoir 200, for introducing the components into the internal chamber 204 of the reservoir 200, as illustrated in view b) of [Fig. 3]. The second part 220 may, for example, include the orifice 208. Said orifice 208 may be equipped with a connector (not shown) suitable for cooperating with a complementary connector of another medical device, such as a syringe or a funnel, for transferring the components constituting the bone cement into the internal chamber 204 of the reservoir 200. The connector may, for example, be of the Luer-Lock type. Port 208 can be fitted with a cover (not shown) to prevent bone cement from flowing through port 208 during the mixing of components in the internal chamber 204 of the tank 200.

[0070] The tank 200 can be made of a transparent material, for example glass or polycarbonate, to allow an operator to view the contents of the tank 200.

[0071] The device 100 further comprises a mixer assembly 400 and a piston assembly 600.

[0072] The mixing assembly 400 is designed to allow the operator to mix the components previously introduced into the internal chamber 204 of the tank 200 in order to obtain bone cement. The mixing assembly 400 of the device 100 is intended to be used during a phase, referred to as the mixing phase, as will be described later.

[0073] The piston assembly 600, for its part, allows the operator to transfer the bone cement obtained in the internal chamber 204 of the reservoir 200 out of said internal chamber 204, via the outlet 207. The piston assembly 600 of the device 100 is intended to be used during a phase, referred to as the injection phase, as will be described later. It is clear from the description that the injection phase is carried out after the mixing phase.

[0074] The piston assembly 600 includes a threaded rod 610, a piston head 630 and a handle 650, as illustrated in Figures 1, 4 to 6.

[0075] The thread of the threaded rod 610 is an external thread, that is to say a thread made at the level of an external surface of the threaded rod 610, as illustrated in [Fig.4]. The threaded rod 610 cooperates with the tapped opening 206 of the reservoir 200. The threaded rod 610 thus has a longitudinal axis coaxial with the longitudinal axis Z of the reservoir 200. The threaded rod 610 extends between two longitudinal ends 611, 612. A first longitudinal end 611 is intended to move outside the internal chamber 204 of the tank 200 and a second longitudinal end 612 is intended to move within said internal chamber 204. The threaded rod 610 is a hollow threaded rod 610, that is to say that it includes an internal longitudinal channel 613 opening at its two longitudinal ends 611, 612.

[0076] The handle 650 of the piston assembly 600 has a through cavity (not shown in the figures) in the extension of the internal longitudinal channel 613.

[0077] The piston head 630 of the piston assembly 600 is arranged at the second longitudinal end 612 of the threaded rod 610. The piston head 630 is arranged in the internal chamber 204 of the reservoir 200 and is configured to be movable in translation, along the longitudinal axis Z of the reservoir 200, between the first end 201 and the second end 202 of the reservoir 200.

[0078] The threaded rod 610 thus has a length at least sufficient for the piston head 630 to move between the two ends 201, 202 of the reservoir 200.

[0079] The piston head 630 is fixedly attached to the threaded rod 610.

[0080] In this description, the term "solid" will refer to parts joined to one another. The other is joined by a connection allowing relative movement of one part with respect to the other. We will designate as "fixedly joined" parts that are mutually linked in a fixed manner, that is to say, that relative movement between them is impossible.

[0081] The piston head 630 is in the form of a solid piece. It has a cross-section complementary to the cross-section of the cylindrical wall 203 of the reservoir 200. Thus, when the cylindrical wall 203 of the reservoir 200 has a circular cross-section, the piston head 630 has the form of a disc with a diameter substantially equal to the internal diameter of the cylindrical wall 203 of the reservoir 200.

[0082] A sealing gasket (not shown) can for example be disposed at the periphery of the piston head 630 in order to fill the space between said periphery of the piston head 630 and the cylindrical wall 203 of the reservoir 200 and thus ensure the seal between the piston head 630 and the cylindrical wall 203 of the reservoir 200.

[0083] The piston head 630 has a through orifice 632 (figures 5 and 6) arranged in continuity with the longitudinal internal channel 613 of the threaded rod 610.

[0084] The handle 650 of the piston assembly 600 is arranged at the first longitudinal end 611 of the threaded rod 610 and is intended for the manipulation of the piston assembly 600 by the operator. The handle 650 is fixedly attached to the threaded rod 610. The handle 650 is arranged so as not to obstruct access to the internal longitudinal channel 613 of the threaded rod 610.

[0085] To use the piston assembly 600, the operator manipulates the handle 650 of the piston assembly 600 by applying a rotation around the longitudinal axis Z. Depending on the direction of rotation of said handle 650, the piston head 630 moves in translation within the reservoir 200, moving away from or towards the first end 201 of said reservoir 200. Thus, when the handle 650 of the piston assembly 600 is operated by the operator in a first direction of rotation, called the tightening direction, for example clockwise, the threaded rod 610 is driven to rotate about its longitudinal axis and causes, on the one hand, the translation, along the longitudinal axis Z, of the piston head 630 towards the second end 202 of the reservoir 200, and on the other hand, the rotation of the piston head about the longitudinal axis Z. When the handle 650 of the piston assembly 600 is operated by the operator in a second direction of rotation, called the loosening direction, that is to say counterclockwise, the threaded rod 610 is driven to rotate about its longitudinal axis and causes, on the one hand, the translation of the piston head 630 towards the first end 201 of the reservoir 200 and on the other part of the rotation of the piston head around the longitudinal axis Z.

[0086] The mixing assembly 400 comprises a rod 410, a mixing paddle 430 and a handle 450, as illustrated in Figures 1 and 7.

[0087] The rod 410 passes through the first end 201 of the reservoir 200 at the level of the threaded opening 206 of the reservoir 200. The rod 410 extends between two longitudinal ends 411,412. A first longitudinal end 411 is intended to move out of the internal chamber 204 of the reservoir 200 and a second longitudinal end 412 is intended to move in the internal chamber 204 of the reservoir 200.

[0088] The mixing paddle 430 is arranged at the second longitudinal end 412 of the rod 410. The mixing paddle 430 is arranged in the internal chamber 204 of the tank 200 and is configured to be mobile on the one hand in translation between the first end 201 and the second end 202 of the tank 200 and on the other hand in rotation around the longitudinal axis Z.

[0089] In a preferred embodiment, as illustrated in Figures 1, 7 and 8, the mixing paddle 430 comprises a plurality of blades 431. Each blade 431 extends from the second longitudinal end 412 of the shaft 410 towards the cylindrical wall 203 of the 200 reservoir. In the non-limiting example of [Fig.8], there are six blades 431, and they have a curved shape.

[0090] In an alternative embodiment (not shown), the mixing palette 430 is in the form of a perforated disc.

[0091] The handle 450 of the mixing assembly 400 is arranged, for its part, at the level of the first longitudinal end 411 of the rod 410 and is intended for the manipulation of the mixing assembly 400 by the operator.

[0092] According to the invention, the mixer assembly 400 is nested within the piston assembly 600. More specifically, the rod 410 of the mixer assembly 400 extends into the internal longitudinal channel 613 of the threaded rod 610 and into the through orifice 632 of the piston head 630 of the piston assembly 600.

[0093] The piston head 630 of the piston assembly 600 is thus arranged, in the internal chamber 204 of the tank 200, between the first end 201 of the tank 200 and the mixing paddle 430 of the mixer assembly 400.

[0094] The handle 650 of the piston assembly 600 is arranged, outside the reservoir 200, between the first end 201 of the reservoir 200 and the handle 450 of the mixer assembly 400.

[0095] The rod 410 of the mixer assembly 400 moves in translation along the longitudinal axis Z and in rotation about said longitudinal axis in the internal longitudinal channel 613 of the threaded rod 610 of the piston assembly 600 and in the through orifice 632 of the piston head 630 of the piston assembly 600.

[0096] The rod 410 of the mixing assembly 400 advantageously has sufficient length so that, when the piston head 630 of the piston assembly 600 is at the level of the first end 201 of the tank 200, the operator can manipulate the handle 450 of the mixing assembly 400 so that the mixing paddle 430 of the mixing assembly 400 can move in the internal chamber 204 of the tank 200, between the piston head 630 and the second end 202 of the tank 200, as illustrated in [Fig.1], 9 and 10.

[0097] The rod 410 of the mixer assembly 400 thus has a length corresponding at least to the length of the reservoir 200 and to the length of the threaded rod 610 of the piston assembly 600.

[0098] In a first embodiment of the device 100, as illustrated in [Fig. 1], the rod 410 of the mixer assembly 400 is an elongated body with a smooth external appearance. It has a cross-sectional shape complementary to the cross-sectional shape of the internal longitudinal channel 613 of the threaded rod 610 of the piston assembly 600 and of the through orifice 632 of the piston head 630 of the piston assembly 600. Thus, in this first embodiment, the internal longitudinal channel 613 of the threaded rod 610 of the piston assembly 600 allows the rod 410 of the mixer assembly 400 to be guided in translation along the longitudinal axis Z, while allowing its rotation around said longitudinal axis. The handle 450 of the mixer assembly 400 is, for its part, fixedly attached to the rod 410 of the mixer assembly 400. In this first version, the operator must apply a translational movement, along the longitudinal axis Z, and a rotational movement, around the longitudinal axis Z, to the handle 450 of the mixer assembly 400 to move the mixing paddle 430 in translation and rotation.

[0099] In a second version (not shown) of the device 100, the rod 410 of the mixer assembly 400 is an elongated body with an external helical groove, i.e., a helical groove formed on an external surface of the elongated body. The internal longitudinal channel 613 of the threaded rod 610 of the piston assembly 600 has an internal helical rib. The external helical groove of the rod 410 of the mixer assembly 400 cooperates with the internal helical groove of the internal longitudinal channel 613 of the threaded rod 610 of the piston assembly 600. When the through cavity of the handle 650 of the piston assembly 600 has a cross-section equal to the cross-section of the internal longitudinal channel 613 of the threaded rod 610 of the piston assembly 600, said through cavity has an internal helical rib in the extension of the internal helical rib of the internal longitudinal channel 613.When the through cavity of the handle 650 of the piston assembly 600 has a diameter greater than the diameter of the internal longitudinal channel 613 of the threaded rod 610 of the piston assembly 600, said through cavity does not have an internal helical rib in the extension of the internal helical rib of the internal longitudinal channel 613. It is also possible that the elongated body of the rod 410 of the mixer assembly 400 has an external helical rib, that is, a helical rib formed on an external surface of the elongated body. The internal longitudinal channel 613 of the threaded rod 610 of the piston assembly 600, on the other hand, has an internal helical groove. The handle 450 of the mixer assembly 400 is fixed to the rod 410 of the mixer assembly 400. A connecting element between the handle 450 and the rod 410 of the mixer assembly 400 allows the rod 410 of the mixer assembly 400 to move in rotation around the longitudinal axis Z relative to the handle 450. In this second version, the operator only needs to apply a translational movement, along the longitudinal axis Z, to the handle 450 of the mixing assembly 400 to move the mixing paddle 430 in translation and rotation. of the mixing assembly 400. The engagement of the helical groove of the rod 410 in the helical rib of the internal longitudinal channel 613 of the threaded rod 610 causes the rod 410 to move in translation and rotation, and consequently the mixing paddle 430 to move in the tank 200.

[0100] In a third version (not shown) of the device 100, the rod 410 of the mixer assembly 400 is an elongated body with an external helical groove. The internal longitudinal channel 613 of the threaded rod 610 of the piston assembly 600 has a smooth surface and a larger cross-section than the rod 410 of the mixer assembly 400. The through-hole of the handle 650 of the piston assembly 600 has a smaller cross-section than the internal longitudinal channel 613 of the threaded rod 610 of the piston assembly 600 and has an internal helical rib. The external helical groove of the rod 410 of the mixer assembly 400 cooperates with the internal helical rib of the through-hole of the handle 650 of the piston assembly. The handle 450 of the mixer assembly 400 is fixed to the rod 410 of the mixer assembly 400. A linking element between the handle 450 and the rod 410 of the mixer assembly 400 allows the rod 410 of the mixer assembly 400 to move in rotation around the longitudinal axis Z relative to the handle 450 of the mixer assembly 400. In this third version, the operator only needs to apply a translational movement, along the longitudinal axis Z, to the handle 450 of the mixing assembly 400 to move the mixing paddle 430 of the mixing assembly 400 in translation and rotation. The engagement of the helical groove of the rod 410 in the helical rib of the through cavity of the handle 650 of the piston assembly 600 causes the rod 410 of the mixing assembly 400 to move in translation and rotation, and consequently the mixing paddle 430 in the tank 200 to move in translation and rotation.

[0101] In one embodiment of the invention, to prevent the mixing paddle 430 from moving in the internal chamber 204 of the reservoir 200 during the injection phase, the mixing paddle 430 can be fixed onto the piston head 630. The mixing paddle is preferably fixed onto the piston head so as to simultaneously obstruct the through orifice 632 of the piston head 630.

[0102] In a preferred embodiment, the mixing paddle 430 can be attached to the piston head 630 by push-fitting, snap-fitting, or screwing. In the non-limiting example shown in Figures 5, 6, and 8, the mixing paddle 430 has an axially extending sleeve 432, and the piston head 630 has a housing 634 adapted to receive the sleeve 432 by push-fitting. The housing 634 has a shape and dimensions adapted for a rigid fit with the sleeve 432. In the example shown in Figures 5, 6, and 8, the housing 634 of the piston head 630 is coaxial with the through-hole 632 of the piston head 630 and larger than the through-hole 632. The housing 634 may, for example, be square, as shown in Figures 5 and 6. The sleeve 432 of the mixing paddle 430 is a central sleeve with an external shape complementary to the shape of the housing 634 of the piston head 630. The blades 431 of the mixing paddle 430 are fixedly attached to the sleeve 432. To attach the mixing paddle 430 to the piston head 630 by fitting it, the operator simply pulls on the rod 410 of the mixing assembly 400 until it that the sleeve 432 engages in the housing 634 until it is fitted together. The mixing paddle sleeve thus simultaneously seals the through orifice 632 of the piston head 630.

[0103] In one embodiment of the invention, to prevent the rod 410 of the mixing assembly 400 from hindering the movements of the operator when he is in the injection phase, the rod 410 of the mixing assembly 400 can be removable. In one embodiment, the rod 410 of the mixer assembly 400 is removable at the second longitudinal end 412. In one embodiment, as illustrated in [Fig. 8], the rod 410 of the mixing assembly 400 has, at its second longitudinal end 412, a thread 413, and the sleeve 432 of the mixing paddle 430 has a central tapped cavity 433. The thread 413 of the rod 410 and the tapped hole of the central cavity 433 cooperate. When the operator wishes to remove the rod 410 from the device 100, the operator must first attach the mixing paddle 430 to the piston head 630, making the mixing paddle 430 permanently fixed to the piston head 630. Then, the operator can unscrew the rod 410. When the thread 413 of the rod 410 is out of the tapped hole in the central cavity 433 of the sleeve 432, the operator can extract the rod 410 from the internal longitudinal channel 613 of the threaded rod 610 of the piston assembly 600.

[0104] Alternatively, to prevent the rod 410 of the mixer assembly 400 from hindering the movements of the operator when he is in the injection phase, the rod 410 can be broken. In one embodiment, as illustrated in [Fig.10], the rod 410 of the mixer assembly 400 may have a zone of weakness 415 allowing the breakage of said rod to begin. The term "zone of weakness" refers to a zone of mechanical weakening of the rod 410. In one embodiment, as illustrated in [Fig. 10], the zone of weakness 415 may be a zone of reduced thickness. In another embodiment (not shown), the area of ​​weakness can be a notch. Preferably, as illustrated in [Fig. 10], the area of ​​weakness 415 is made on the rod 410, on a portion located at the handle 650 of the piston assembly 600, when the piston head 630 and the mixing vane 430 are both at the first end 201 of the tank 200. The rupture of the fragility zone 415 is preferentially achieved by a manual action on the part of the operator.

[0105] In one embodiment of the invention, illustrated in [Fig. 12], to facilitate the handling of the device 100 by the operator, said device includes a gripping member 800, of the handle type. In one embodiment of the gripping member (not shown in the figures), said gripping member is formed by two half-shells joined together, enclosing the reservoir 200 at its cylindrical wall 203. The first and second ends 201, 202 of the reservoir 200 are not enclosed by the two half-shells. In this embodiment, the components are introduced either through the opening 208 in the cylindrical wall 203 or through the first end 201 of the reservoir 200, when the reservoir is in two removable parts 210, 220, as illustrated [Fig. 2]. In another embodiment, illustrated by [Fig. 12], the gripping member is formed by two half-shells assembled together, enclosing the reservoir 200, at least at its first end 201, and a portion of the threaded rod 610 of the piston assembly 600. Each half-shell may have a recess which, when the two half-shells are assembled, forms a threaded hole cooperating with the thread of the threaded rod 610 of the piston assembly 600. In this other embodiment, the components are preferably introduced through the orifice 208 of the cylindrical wall 203, as illustrated in [Fig. 12]. Device 100 Operation

[0106] An example of the operation of device 100 is now described.

[0107] In a preliminary phase, the components are introduced into the internal chamber 204 of the tank.

[0108] The piston head 630 of the piston assembly 600 and the mixing paddle 430 of the mixer assembly 400 are each placed towards the first end 201 of the tank 200.

[0109] In one embodiment, when the tank 200 has two removable parts 210, 220, as illustrated in view a) of [Fig. 2], the operator disassembles the two parts 210, 220 by unscrewing them. He then inserts the components in the second part 220, then reassemble the two parts 210, 220 to close the tank 200, screwing the two parts together.

[0110] In another example of implementation, when the tank 200 has, at the level of its cylindrical wall 203, an orifice 208, as illustrated in view b) of [Fig.2] and views a) and b) of [Fig.3], the operator introduces the components through this orifice 208.

[0111] Once the components have been introduced into the internal chamber 204 of the tank, the mixing phase can begin.

[0112] The operator grasps the handle 450 of the mixing assembly 400 and applies a translational movement, and possibly a rotational movement depending on the version of the device 100, to the mixing assembly 400 to move the mixing paddle 430 in translation and rotation in the internal chamber 204 of the tank 200, between the first end 210 and the second end 220 of said tank, as illustrated in Figures 1 and 9. The movement of the mixing paddle 430 in the internal chamber 204 of the tank 200 thus makes it possible to mix the components together until the formation of the bone cement.

[0113] The piston head 630 of the piston assembly 600 remained in position, at the level of the first end 201 of the reservoir 200, throughout the mixing phase.

[0114] When the mixing phase is complete, the operator brings the mixing paddle 430 back to the first end 201 of the tank 200 and then fixes the mixing paddle 430 with the piston head 630 of the piston assembly 600 to make them fixedly joined.

[0115] In one embodiment example, the operator pulls on the handle 450 of the mixing assembly 400 until the sleeve 432 of the mixing paddle 430 fits into the housing 634 of the piston head 630 of the piston assembly 600, as illustrated in [Fig. 10].

[0116] When the mixing paddle 430 is fixedly attached to the piston head 630 of the piston assembly 600, the operator can, depending on the variant of the device, either break the rod 410 of the mixing assembly 400, at its area of ​​weakness 415, or unscrew the rod 410 of the mixing assembly 400 from the sleeve 432 of the mixing paddle 430.

[0117] The injection phase can then begin. The operator grasps the handle 650 of the piston assembly 600 and turns it clockwise to screw the threaded rod into the tapped opening of the reservoir, causing the piston head 630 and the mixing paddle 430 to move in translation towards the second end 202 of the reservoir 200, pushing the bone cement obtained through the outlet orifice 207 of the reservoir 200.

[0118] Thanks to the engagement of the threaded rod 630 of the piston assembly 600 in the threaded opening 206 of the reservoir 200, the device 100 advantageously allows the bone cement to be easily injected, even when it has a high viscosity, without breaking.

[0119] The above description clearly illustrates that, through its various characteristics and their advantages, the present invention achieves the objectives it had set for itself. In particular, it provides a device that allows both the mixing of components to obtain a composition, and its injection, with high pressure, without excessive handling by the operator.

[0120] Although the invention has been described in the context of use in the medical field, this does not preclude its use in other fields of application. For example, it is conceivable to use the device in the construction industry for repairing cracks.

Claims

Demands

1. Device (100) for mixing and injecting a composition comprising: - a reservoir (200) comprising a cylindrical wall (203), a first end (201) and a second end (202), delimiting an internal chamber (204), and with longitudinal axis (Z), the reservoir comprising, at its first end (201), a threaded opening (206), the reservoir having, at its second end (202), an outlet orifice (207), - a piston assembly (600) comprising a threaded rod (610), a handle (650) located at a first end (611) of the threaded rod and a piston head (630) located at a second end (612) of the threaded rod, the threaded rod (610): • cooperating with the threaded opening (206) of the reservoir (200), • extending along the longitudinal axis (Z) of the reservoir (200), • comprising an internal longitudinal channel (613) opening at its two longitudinal ends (611, 612), the piston head (630): • being arranged in the internal chamber (204) of the reservoir (200), • having a cross-section with a shape complementary to the shape of the cross-section of the cylindrical wall (203) of the tank (200), • comprising a through orifice (632) in continuity with the internal longitudinal channel (613) of the threaded rod (610), • a mixing assembly (400) comprising a shaft (410), a handle (450) located at a first end (411) of the shaft and a mixing paddle (430) located at a second end (612) of the shaft, the rod (410) of the mixer assembly (400) extending into the internal longitudinal channel (613) of the threaded rod (610) and into the through orifice (632) of the piston head (630) of the piston assembly (600), the mixing paddle (430) being arranged in the internal chamber (204) of the tank (200).

2. Device (100) according to claim 1 in which the reservoir is made in two removable parts (210, 220) a first part (210) comprising the threaded opening (206) of the reservoir (200) and a second part (220) comprising the outlet orifice (207) of the reservoir (200), the first part (210) forming a cover for the second part (220).

3. Device (100) according to any one of the preceding claims in which the tank (200) has an orifice (208) made in the cylindrical wall (203) for the introduction of the constituent components of the composition into the internal chamber (204) of the tank (200).

4. Device (100) according to any one of the preceding claims wherein the rod (410) of the mixer assembly (400) is an elongated body, smooth on the outside, and has a cross-section of shape complementary to the shape of the cross-section of the internal longitudinal channel (613) of the threaded rod (610) of the piston assembly (600).

5. Device (100) according to any one of claims 1 to 3 in which: - the internal longitudinal channel (613) of the threaded rod (610) of the piston assembly (600) has an internal helical rib, - the rod (410) of the mixer assembly (400) is an elongated body, having an external helical groove, said external helical groove cooperating with the internal helical rib of the internal longitudinal channel (613) of the threaded rod (610) of the piston assembly (600).

6. Device (100) according to any one of the preceding claims wherein the mixing paddle (430) of the mixer assembly (400) is fixedly attached to the piston head (630) during an injection phase.

7. Device (100) according to the preceding claim, wherein the mixing paddle (430) of the mixer assembly (400) comprises a

8.

9.

10. sleeve (432), and the piston head (630) of the piston assembly (600) has a housing (634) suitable for receiving the sleeve (432) by insertion. Device (100) according to any one of the preceding claims wherein the rod (410) of the mixer assembly (400) is removable. Device (100) according to any one of the preceding claims in which the rod (410) of the mixer assembly (400) has a zone of weakness (415) enabling the breakage of said rod to begin. Device (100) according to any one of the preceding claims comprising a gripping member (800), of the handle type.

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