Expansion screw capable of injecting bone cement and injection method thereof

Abstract

The present invention provides an expansion screw capable of injecting bone cement and an injection method thereof, belonging to the technical field of bone cement injection. The invention comprises a screw head, one end of the screw head is fixedly connected with a threaded rod, the other end is provided with a hexagonal slot, a through injection hole is provided at the center of the screw head, an injection head connected with the injection hole is fixedly connected with the surface of the hexagonal slot, the threaded rod comprises an integrally connected threaded section and an expansion section, one end of the threaded section is provided with an elastic groove connected with a silicone sealing ring, and a sealing structure is fixedly connected with the bottom of the elastic groove. The present invention can inject bone cement directly through the screw head and the threaded rod after being fixed with the expansion screw, and the bone cement enters the patient's bone through the injection structure inside the threaded rod, which can effectively relieve the pressure of the injected bone cement, thereby avoiding excessive pressure of the injected bone cement, which may cause secondary injury to the fracture site.

Description

Technical Field

[0001] The invention relates to the technical field of bone cement injection, and in particular to an expansion screw capable of injecting bone cement and an injection method thereof. Background Art

[0002] Bone cement is a medical material used to treat fractures and osteoporosis, also known as bone cement vertebroplasty. It is usually used to treat vertebral fractures or vertebral collapse caused by osteoporosis. Bone cement reinforces the vertebral body by injecting a specific type of resin or cement into the vertebral body, thereby relieving pain and restoring the stability of the vertebral body.

[0003] A bone cement screw is a device used to treat fractures. It is a screw made of titanium alloy or stainless steel. The screw is inserted into the bone, and a special needle is used to inject bone cement into the bone tissue around the screw to enhance the stability of the fracture.

[0004] When an elderly patient has a fracture, bone cement is generally injected to fix the fracture. However, bone cement screws are prone to falling off and loosening after the operation. When the bone cement is injected into the bone cement syringe, the bone cement injection pressure is prone to being too high, causing secondary injury to the patient. At the same time, the connection with the bone cement syringe is relatively cumbersome. Therefore, the present invention provides an expansion screw that can be injected with bone cement and an injection method thereof to meet the needs. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an expansion screw that can be injected with bone cement and an injection method thereof to solve the problem that when fractures occur in elderly patients, bone cement is generally injected for fixation, the bone cement screws are prone to fall off and the screws are loose after the operation, and when the bone cement is injected by the bone cement syringe, the bone cement injection pressure is prone to be too high, causing secondary injuries to the patient. At the same time, the connection is relatively cumbersome when adapting to the bone cement syringe.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A bone cement-injectable expansion screw comprises a screw head, one end of the screw head is fixedly connected to a threaded rod, the other end is provided with a hexagonal groove, a penetrating injection hole is provided at the center of the screw head, an injection head connected to the injection hole is fixedly connected to the surface of the hexagonal groove, the threaded rod comprises an integrally connected threaded section and an expansion section, one end of the threaded section is provided with an elastic groove connected to a silicone sealing ring, a sealing structure is fixedly connected to the bottom of the elastic groove, a plurality of groups of expansion limit plates distributed in an array with the expansion section as the axis are fixedly connected to the outer wall of the expansion section, and every two mutually symmetrical expansion limit plates form a group; an injection structure for connecting the injection head to the expansion limit plates is also included.

[0008] Optionally, the injection structure includes a first connecting groove opened at one end of the elastic groove, the expansion section is provided with an annular expansion groove on the inner side close to the expansion limit piece, and four second connecting grooves connected to each other are opened between the first connecting groove and the expansion groove.

[0009] Optionally, the expansion limit piece includes a weakened section and a limiting section connected to each other, the weakened section is integrally connected to the outer wall of the expansion section, the inner wall of the expansion limit piece gradually changes from thin to thick from the weakened section to the limiting section, the expansion groove and the inner wall on the corresponding side of the expansion limit piece are arc-shaped expansion heads, the limiting sections of each group of two expansion limit pieces are spaced 1 mm apart, and the spacing between each two groups of expansion limit pieces is 1 mm. A weakened groove is provided on the outer wall at the connection between the weakened section and the expansion section, a plurality of reinforcing ribs are fixedly connected to the inner wall of the first connecting groove, the two ends of the second connecting groove are V-shaped notches, and the four second connecting grooves are distributed at 90° to each other.

[0010] Optionally, a fastening groove is provided on the outer wall of the expansion limiting piece, and a fastening piece is fixedly connected to the inner surface of the fastening groove.

[0011] Optionally, the fastening sheet includes a first mesh sheet and a second mesh sheet which are fixed in turn on the surface of the fastening groove, the first mesh sheet and the second mesh sheet are respectively fixed at 1 / 3 and 2 / 3 depth positions of the fastening groove, and the surfaces of the first mesh sheet and the second mesh sheet are provided with a plurality of fastening openings of the same specifications, and the fastening openings on the first mesh sheet and the second mesh sheet are staggered with each other.

[0012] Optionally, the sealing structure includes an elastic sheet fixed to one end of the elastic groove, a sealing hemisphere is fixedly connected to the top surface of the elastic sheet, a sealing groove is opened on the surface of the screw head on one side close to the threaded rod, a silicone sealing ring is nested and connected to the inner surface wall of the sealing groove, and the screw head and the threaded rod are fixedly connected by the silicone sealing ring and the sealing hemisphere.

[0013] Optionally, the elastic sheet includes a connected plane segment, an arc segment and a supporting segment, the plane segment is a cross-shaped structure, the four ports of the plane segment are connected to the supporting segment, one end of the supporting segment is connected to the arc segment, the arc segment is fixedly connected to the bottom of the elastic groove, and the bottom of the sealing hemisphere is provided with a limit adapter groove matched with the plane segment, and the plane segment is nested in the limit adapter groove.

[0014] Optionally, a sliding ring is provided on the inner surface wall of the injection head, support rods are fixedly connected to both sides of one end of the sliding ring, an extrusion plate is fixedly connected to the bottom end of the support rod, and an extrusion structure for adapting to the sliding of the sliding ring is also included.

[0015] Optionally, the extrusion structure includes sliding plates fixed on both sides of the top of the sliding ring, the outer wall of the injection head is provided with a sliding opening corresponding to the sliding plate, the outer wall of the injection head is provided with a sliding groove near the bottom of the sliding opening, and the sliding plate passes through the sliding opening and extends to the surface of the sliding groove.

[0016] The present invention also provides a method for injecting an expansion screw capable of injecting bone cement, comprising the following steps:

[0017] S1. First, make a hole on the patient's bone where the bone cement needs to be injected;

[0018] S2, inserting the expansion section of the threaded rod into the pre-punched hole, and then inserting the expansion section into the threaded section, inserting a screwdriver into the hexagonal slot to screw the remaining threaded section into the hole, and screwing the entire threaded section into the hole;

[0019] S3, screwing the injection head of the bone cement syringe with prepared bone cement into the injection head on the screw head, the injection head will continuously drive the slide to move toward the bottom of the hexagonal groove until the injection head is screwed to a suitable position, the displacement of the slide will drive the sliding ring to move downward, and then drive the extrusion plate on the support rod to squeeze the sealing hemisphere, so that a gap appears between the sealing hemisphere and the silicone sealing ring, so that the bone cement can be injected into the first connecting groove;

[0020] S4, bone cement enters the expansion groove from the inside of the first connecting groove through the second connecting groove, and the bone cement entering the expansion groove gradually fills the expansion groove. Under the action of the expansion head, the bone cement inside the expansion groove is squeezed from the middle position of the expansion head to the upper and lower sides of the expansion groove, and the weakened section is deformed. The bone cement will slowly squeeze the limiting section to the outside and expand it. The expanded expansion limiting piece will be limited in position during the solidification of the bone cement, so that the expansion section of the threaded rod is stably limited in the solidified bone cement package;

[0021] S5. After the bone cement injected by the bone cement syringe reaches the target amount, the injection head is removed.

[0022] Compared with the prior art, the present invention has at least the following beneficial effects:

[0023] In the above scheme, after fixation with the expansion screw, bone cement can be injected directly through the screw head and the threaded rod. The bone cement enters the patient's bone through the injection structure inside the threaded rod, which can effectively relieve the pressure of the injected bone cement, avoiding excessive pressure of the injected bone cement, which may cause secondary injury to the fracture site.

[0024] By setting up a sealing structure, the sealing structure can be opened during injection in conjunction with the bone cement syringe, and automatically closed after the injection is completed, thereby avoiding the overflow of bone cement and preventing external tissue fluid from entering the injection structure.

[0025] By setting an expansion limit plate, the expansion limit plate can be deformed during the injection process of bone cement. The expanded limit plate will be limited in position during the solidification of the bone cement, so that the expansion section of the threaded rod can be stably restricted in the solidified bone cement package, achieving expansion limitation and preventing the threaded rod from deviating and loosening. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable those skilled in the relevant art to make and use the present disclosure.

[0027] Figure 1 It is a schematic diagram of the stereoscopic structure of an expansion screw that can be injected with bone cement from a first-person perspective;

[0028] Figure 2 A schematic diagram of the stereoscopic structure of an expansion screw that can be injected with bone cement from a second perspective;

[0029] Figure 3 It is a schematic diagram of the cutaway three-dimensional structure of an expansion screw that can be injected with bone cement;

[0030] Figure 4 for Figure 2 A in the middle is an enlarged schematic diagram of the three-dimensional structure;

[0031] Figure 5 for Figure 3 The enlarged three-dimensional structure diagram at B in the middle;

[0032] Figure 6 A schematic diagram of the enlarged structure of the injection head and the sliding ring assembly;

[0033] Figure 7 This is a schematic diagram of the exploded three-dimensional structure of the injection head and the sliding ring;

[0034] Figure 8 A schematic diagram of a multi-view stereoscopic magnified structure for assembling a sealing hemisphere and an elastic sheet;

[0035] Fig. 9 It is a three-dimensional enlarged structural schematic diagram of the fastening plate;

[0036] Fig.10 It is a schematic diagram of the enlarged three-dimensional structure of the fastening plate.

[0037] [Reference Signs]

[0038] 1. Screw head; 11. Hexagonal groove; 12. Injection hole; 13. Silicone sealing ring; 2. Threaded rod; 21. Threaded section; 211. Elastic groove; 212. First connecting groove; 2121. Reinforcement rib; 213. Second connecting groove; 22. Expansion section; 221. Expansion limit plate; 2211. Weakened section; 2212. Limit section; 222. Fastening groove; 223. Weakened groove; 224. Expansion groove; 2241. Expansion head; 3. Injection head; 31. Sliding port; 32. Sliding groove; 4. Sliding ring; 41. Sliding plate; 42. Support rod; 43. Extrusion plate; 5. Sealing hemisphere; 51. Limiting adapter groove; 6. Elastic plate; 61. Plane section; 62. Arc section; 63. Support section; 7. Fastening plate; 71. First mesh; 72. Second mesh; 73. Fastening port.

[0039] As shown in the figure, in order to clearly implement the structure of the embodiment of the present invention, specific structures and devices are marked in the figure, but this is only for illustrative purposes and is not intended to limit the present invention to the specific structure, device and environment. According to specific needs, ordinary technicians in this field can adjust or modify these devices and environments, and the adjustments or modifications made are still included in the scope of the attached claims. DETAILED DESCRIPTION

[0040] The following is a detailed description of an expansion screw capable of injecting bone cement and an injection method thereof provided by the present invention in conjunction with the accompanying drawings and specific embodiments. At the same time, it is explained here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternatives to implement some known technologies; and the accompanying drawings are only for a more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0041] It should be noted that the references to "one embodiment", "embodiment", "exemplary embodiments", "some embodiments" and the like in the specification indicate that the embodiments described may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, when a specific feature, structure or characteristic is described in conjunction with an embodiment, it should be within the knowledge of a person skilled in the art to implement such feature, structure or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0042] In general, a term can be understood, at least in part, from its use in context. For example, depending, at least in part, on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense. Additionally, the term "based on" can be understood as not necessarily intended to convey an exclusive set of factors, but can instead, depending, at least in part, on the context, allow for the presence of other factors that are not necessarily explicitly described.

[0043] It will be understood that the meaning of “on,” “over,” and “above” in this disclosure should be interpreted in the broadest manner, so that “on” means not only “directly on” something, but also includes the meaning of being “on” something with intervening features or layers therebetween, and “on” or “over” means not only “on” or “above” something, but also includes the meaning of being “on” or “above” something with no intervening features or layers therebetween.

[0044] Additionally, spatially relative terms such as "under," "beneath," "lower," "above," "upper," and the like may be used herein for descriptive convenience to describe the relationship of one element or feature to another element or features, as shown in the accompanying drawings. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. The device may be oriented in other ways, and the spatially relative descriptors used herein may be similarly interpreted accordingly.

[0045] like Figures 1 to 3 As shown, an embodiment of the present invention provides an expansion screw that can be injected with bone cement, including a screw head 1, one end of the screw head 1 is fixedly connected to a threaded rod 2, the other end is provided with a hexagonal groove 11, a through injection hole 12 is provided at the center of the screw head 1, the surface of the hexagonal groove 11 is fixedly connected to an injection head 3 connected to the injection hole 12, the outer wall of the injection head 3 is provided with a thread, which can be adapted to the injection head of an external bone cement syringe, so that the bone cement syringe can be directly detachably connected to the screw head 1 through the injection head 3, and the threaded rod 2 is provided at the center of the screw head 1. It includes an integrally connected threaded section 21 and an expansion section 22, the outer ring diameter of the expansion section 22 is smaller than the outer ring diameter of the threaded section 21, one end of the threaded section 21 is provided with an elastic groove 211 connected to the silicone sealing ring 13, the bottom of the elastic groove 211 is fixedly connected with a sealing structure, the outer wall of the expansion section 22 is fixedly connected with a plurality of groups of expansion limit plates 221 distributed in an array with the expansion section 22 as the axis, and each two mutually symmetrical expansion limit plates 221 form a group; it also includes an injection structure for connecting the injection head 3 with the expansion limit plate 221.

[0046] When the fracture site of the patient needs to be fixed and bone cement is injected, first a hole is made on the patient's bone where the bone cement needs to be injected. After the hole is drilled, the fracture site is fixed with expansion screws and titanium alloy steel plates. When installing the expansion screw, first insert the expansion section 22 of the threaded rod 2 into the pre-opened hole. Then, when inserting it to the threaded section 21, insert the screwdriver into the hexagonal groove 11 to screw the remaining threaded section 21 into the hole, and then screw the injection head of the bone cement syringe with the prepared bone cement into the injection head 3 on the screw head 1. The injected bone cement squeezes the sealing structure open under the pressure of the bone cement syringe, so that the bone cement can enter the first connecting groove 212. The bone cement that enters the first connecting groove 212 enters the expansion groove 224 from the injection structure under the continuous pressure of the bone cement syringe. Since the spacing between the expansion limit plates 221 is small, the bone cement will first fill the expansion groove 224. After being filled, the bone cement will relieve the pressure on several adjacent expansion limit plates 221. During the pressure relief process, the expansion limit plates 221 will be squeezed and expanded until the outflow of bone cement is equal to the pressure between the bone cement syringe and the expansion limit plate. The bone cement flowing out of the gap between the pieces 221 will slowly fill into the bone. Through X-ray irradiation, the injection volume of the bone cement is monitored in real time until the injection volume requirement is reached. After the injection, the bone cement solidifies, and the expanded expansion limit piece 221 is further limited and fixed, thereby preventing the threaded rod 2 from loosening. The patient's fracture position can be effectively fixed by the expansion screw, and the injected bone cement can be prevented from seeping from the fracture site into the surrounding tissue. At the same time, after fixation, the bone cement can be directly injected through the screw head 1 and the threaded rod 2. The bone cement enters the patient's bone through the injection structure inside the threaded rod 2, which can effectively relieve the pressure of the injected bone cement and avoid excessive pressure of the injected bone cement, which causes secondary injury to the fracture site. The sealing structure can be opened in conjunction with the bone cement syringe during injection, and automatically closed after the injection is completed, which can avoid the overflow of bone cement and prevent external tissue fluid from entering the injection structure.

[0047] like Figures 3 to 5As shown, the injection structure includes a first connecting groove 212 opened at one end of the elastic groove 211, an annular expansion groove 224 is opened on the inner side of the expansion section 22 near the expansion limit piece 221, four second connecting grooves 213 connected to each other are opened between the first connecting groove 212 and the expansion groove 224, the expansion limit piece 221 includes a weakened section 2211 and a limit section 2212 connected to each other, the weakened section 2211 is integrally connected to the outer wall of the expansion section 22, the inner wall of the expansion limit piece 221 gradually changes from thin to thick from the weakened section 2211 to the limit section 2212, and the expansion groove 224 is connected to the expansion limit piece 221 on the corresponding side. The inner wall is an arc-shaped expansion head 2241, the limiting sections 2212 of each group of two expansion limiting pieces 221 are spaced 1 mm apart, and the spacing between each two groups of expansion limiting pieces 221 is 1 mm. A weakening groove 223 is provided on the outer wall at the connection between the weakened section 2211 and the expansion section 22, and a plurality of reinforcing ribs 2121 are fixedly connected to the inner wall of the first connecting groove 212. The reinforcing ribs 2121 can strengthen the strength of the inner wall of the first connecting groove 212 to prevent the threaded section 21 from being broken by force during the twisting process. The two ends of the second connecting groove 213 are V-shaped notches, and the four second connecting grooves 213 are distributed at 90° to each other.

[0048] The bone cement enters the expansion groove 224 from the inside of the first connecting groove 212 through the second connecting groove 213. The bone cement entering the expansion groove 224 will gradually fill the expansion groove 224. After the bone cement fills the expansion groove 224, under the continuous squeezing of the bone cement inside the second connecting groove 213, it will receive a force in the direction of the second connecting groove 213. Since the expansion limit piece 221 faces the expansion head 2241, which is arc-shaped, the bone cement inside the expansion groove 224 is moved from the middle position of the expansion head 2241 to the expansion head 2241 under the action of the expansion head 2241. The upper and lower sides of the expansion groove 224 are squeezed, and at the same time, the weakened section 2211 of the expansion limit piece 221 is only 0.5mm, and a weakened groove 223 is opened on the outer wall. Therefore, under the squeezing pressure of the bone cement inside the expansion groove 224, the weakened section 2211 is deformed, and the bone cement will slowly squeeze the limit section 2212 outward and expand. The expanded expansion limit piece 221 will be limited in position during the solidification of the bone cement, so that the expansion section 22 of the threaded rod 2 is stably limited in the solidified bone cement package, realizing expansion limitation, and preventing the threaded rod 2 from deviating and loosening.

[0049] like Figure 4 , Fig. 9 and Fig.10As shown, the outer wall of the expansion limit piece 221 is provided with a fastening groove 222, and the inner surface of the fastening groove 222 is fixedly connected with a fastening piece 7, and the fastening piece 7 includes a first mesh piece 71 and a second mesh piece 72 fixed to the surface of the fastening groove 222 in sequence, and the first mesh piece 71 and the second mesh piece 72 are respectively fixed at 1 / 3 and 2 / 3 depth positions of the fastening groove 222, and the surfaces of the first mesh piece 71 and the second mesh piece 72 are provided with a plurality of fastening openings 73 of the same specifications, and the fastening openings 73 on the first mesh piece 71 and the second mesh piece 72 are The openings 73 are staggered with each other; when the bone cement overflowing the expansion section 22 enters the bone, it will gradually fill the bone and wrap the outside of the expansion section 22 at the same time. The bone cement wrapping the expansion section 22 will flow from the fastening groove 222 into the first mesh 71 and the second mesh 72, and then fill the entire fastening groove 222. Since the fastening openings 73 on the first mesh 71 and the second mesh 72 are staggered with each other, the solidified bone cement can be more tightly and firmly attached to the fastening groove 222, further limiting and fixing the expansion limit plate 221.

[0050] like Figure 3 and Figure 8 As shown, the sealing structure includes an elastic sheet 6 fixed to one end of the elastic groove 211, a sealing hemisphere 5 is fixedly connected to the top surface of the elastic sheet 6, a sealing groove is provided on the surface of the side of the screw head 1 close to the threaded rod 2, a silicone sealing ring 13 is nested and connected to the inner surface wall of the sealing groove, the screw head 1 and the threaded rod 2 are fixedly connected by the silicone sealing ring 13 and the sealing hemisphere 5, the elastic sheet 6 includes a plane section 61, an arc section 62 and a supporting section 63 connected to each other, the plane section 61 is a cross-shaped structure, four ports of the plane section 61 are connected to the supporting section 63, one end of the supporting section 63 is connected to the arc section 62, the thickness of the arc section 62 gradually becomes thicker from the middle to the two ends, the arc section 62 is fixedly connected to the bottom of the elastic groove 211, a limiting adapter groove 51 matched with the plane section 61 is provided at the bottom of the sealing hemisphere 5, and the plane section 61 is nested and installed in the limiting adapter groove 51.

[0051] The injection head 3, injection hole 12, sealing groove and elastic groove 211 are interconnected, the inner ring diameter of the silicone sealing ring 13 is consistent with the inner ring diameter of the injection head 3 and the injection hole 12, and the diameter of the sealing hemisphere 5 is consistent with the diameter of the elastic groove 211. When the screw head 1 and the threaded rod 2 are connected, the sealing hemisphere 5 will be squeezed toward the silicone sealing ring 13 under the elastic force of the elastic sheet 6, so that the screw head 1 and the threaded rod 2 are sealed through the silicone sealing ring 13 and the sealing hemisphere 5. The plane section 61 of the elastic sheet 6 is adapted to the limiting adapter groove 51, so that the elastic sheet 6 will not be offset during the process of squeezing the sealing hemisphere 5. At the same time, the deformation of the arc section 62 provides elastic force, so that the pressure of the elastic sheet 6 on the sealing hemisphere 5 is more uniform. At the same time, the elastic sheet 6 is integrally die-cast by a steel plate, and the manufacturing process is simple.

[0052] like Figure 3 , Figure 6 and Figure 7 As shown, the inner surface wall of the injection head 3 is provided with a sliding ring 4, and support rods 42 are fixedly connected to both sides of one end of the sliding ring 4, and an extrusion plate 43 is fixedly connected to the bottom end of the support rod 42, and also includes an extrusion structure for adapting the sliding of the sliding ring 4, and the extrusion structure includes slides 41 fixed to both sides of the top of the sliding ring 4, and the outer surface wall of the injection head 3 is provided with a sliding port 31 corresponding to the slide 41, and the outer surface wall of the injection head 3 is provided with a slide groove 32 near the bottom of the sliding port 31, one end of the slide 41 is a U-shaped structure adapted to the sliding port 31, and the other end is an L-shaped structure perpendicular to the slide groove 32, and the slide 41 passes through the sliding port 31 and extends on the surface of the slide groove 32; the outer ring diameter of the sliding ring 4 is consistent with the inner ring diameter of the injection head 3, the sliding ring 4 is nested in the inner surface wall of the injection head 3, and the extrusion plate 43 is connected to the sealing hemisphere 5 The surface is connected. In the initial position, the distance between the L-shaped end of the slide 41 and the bottom surface of the hexagonal groove 11 is consistent with the height of the sliding port 31. Therefore, when the injection head of the external bone cement syringe is screwed into the injection head 3, the bottom of the injection head will contact the L-shaped end of the slide 41 during the screwing-in process. Continuing to screw in the injection head will continue to drive the slide 41 to move toward the bottom of the hexagonal groove 11 until the injection head is screwed in properly. The displacement of the slide 41 will drive the sliding ring 4 to move downward, and then drive the extrusion plate 43 on the support rod 42 to squeeze the sealing hemisphere 5, so that a gap appears between the sealing hemisphere 5 and the silicone sealing ring 13, so that bone cement can be injected. When the injection head of the bone cement syringe is screwed out, the sealing hemisphere 5 will fit and seal with the silicone sealing ring 13 again under the action of the elastic sheet 6, and at the same time restore the slide 41 to its initial position.

[0053] The present invention also provides a method for injecting an expansion screw capable of injecting bone cement, comprising the following steps:

[0054] S1. First, make a hole on the patient's bone where the bone cement needs to be injected;

[0055] S2. Insert the expansion section 22 of the threaded rod 2 into the pre-punched hole, and then insert it to the threaded section 21, insert a screwdriver into the hexagonal slot 11 to screw the remaining threaded section 21 into the hole, and screw the entire threaded section 21 into the hole.

[0056] S3. Screw the injection head of the bone cement syringe with prepared bone cement into the injection head 3 on the screw head 1. The injection head will continue to drive the slide 41 to move toward the bottom of the hexagonal groove 11 until the injection head is screwed to a suitable position. The displacement of the slide 41 will drive the sliding ring 4 to move downward, and then drive the extrusion plate 43 on the support rod 42 to squeeze the sealing hemisphere 5, so that a gap appears between the sealing hemisphere 5 and the silicone sealing ring 13, so that the bone cement can be injected into the first connecting groove 212.

[0057] S4. Bone cement enters the expansion groove 224 from the inside of the first connecting groove 212 through the second connecting groove 213. The bone cement entering the expansion groove 224 will gradually fill the expansion groove 224. Under the action of the expansion head 2241, the bone cement inside the expansion groove 224 is squeezed from the middle position of the expansion head 2241 to the upper and lower sides of the expansion groove 224, and the weakened section 2211 is deformed. The bone cement will slowly squeeze the limiting section 2212 to the outside and expand it. The expanded expansion limiting piece 221 will be limited in position during the solidification of the bone cement, so that the expansion section 22 of the threaded rod 2 is stably confined in the solidified bone cement package.

[0058] S5. After the bone cement injected by the bone cement syringe reaches the target amount, the injection head is removed.

[0059] The technical solution provided by the present invention can directly inject bone cement through the screw head and the threaded rod after fixation with the expansion screw, without the need to drill holes in the patient's bone again. The bone cement enters the patient's bone through the injection structure inside the threaded rod, and the injection structure can effectively relieve the pressure of the injected bone cement, thereby avoiding excessive pressure of the injected bone cement, which may cause secondary injury to the fracture site.

[0060] By setting up a sealing structure, the sealing structure can be opened during injection in conjunction with the bone cement syringe, and automatically closed after the injection is completed, thereby avoiding the overflow of bone cement and preventing external tissue fluid from entering the injection structure.

[0061] By setting an expansion limit plate, the expansion limit plate can be deformed during the injection process of bone cement. The expanded limit plate will be limited in position during the solidification of the bone cement, so that the expansion section of the threaded rod can be stably restricted in the solidified bone cement package, achieving expansion limitation and preventing the threaded rod from deviating and loosening.

[0062] The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention. In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, in order to avoid unnecessary confusion about the essence of the present invention, well-known methods, processes, procedures, components and circuits are not described in detail.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An expansion screw capable of being injected with bone cement, characterized in that: It comprises a screw head, one end of which is fixedly connected to a threaded rod, the other end of which is provided with a hexagonal slot, and a through injection hole is provided at the center of the screw head; The surface of the hexagonal groove is fixedly connected with an injection head connected with the injection hole, the threaded rod includes a threaded section and an expansion section connected in one piece, one end of the threaded section is provided with an elastic groove connected with a silicone sealing ring, the bottom of the elastic groove is fixedly connected with a sealing structure, and the outer wall of the expansion section is fixedly connected with a plurality of groups of expansion limit pieces distributed in an array with the expansion section as the axis, and each two mutually symmetrical expansion limit pieces form a group; Also included is an injection structure for connecting the injection head with the expansion limiter; The injection structure comprises a first connecting groove opened at one end of the elastic groove, an annular expansion groove is opened on the inner side of the expansion section close to the expansion limit piece, and four second connecting grooves connected to each other are opened between the first connecting groove and the expansion groove; The expansion limit piece includes a weakened section and a limit section connected to each other, the weakened section is integrally connected to the outer wall of the expansion section, the inner wall of the expansion limit piece gradually changes from thin to thick from the weakened section to the limit section, the inner wall of the corresponding side of the expansion groove and the expansion limit piece is an arc-shaped expansion head, a weakened groove is provided on the outer wall at the connection between the weakened section and the expansion section, a plurality of reinforcing ribs are fixedly connected to the inner wall of the first connecting groove, the two ends of the second connecting groove are V-shaped notches, and the four second connecting grooves are distributed at 90° to each other.

2. The bone cement injectable expansion screw according to claim 1, characterized in that: The spacing between the limiting sections of each group of two expansion limiting pieces is 1 mm, and the spacing between each group of two expansion limiting pieces is 1 mm.

3. The bone cement injectable expansion screw according to claim 1, characterized in that: The outer wall of the expansion limiting piece is provided with a fastening groove, and the inner surface of the fastening groove is fixedly connected with a fastening piece.

4. The bone cement injectable expansion screw according to claim 3, characterized in that: The fastening sheet includes a first mesh sheet and a second mesh sheet which are fixed in turn on the surface of a fastening groove, the first mesh sheet and the second mesh sheet are respectively fixed at 1 / 3 and 2 / 3 depth positions of the fastening groove, the surfaces of the first mesh sheet and the second mesh sheet are both provided with a plurality of fastening openings of the same specifications, and the fastening openings on the first mesh sheet and the second mesh sheet are staggered with each other.

5. The bone cement injectable expansion screw according to claim 1, characterized in that: The sealing structure includes an elastic sheet fixed to one end of the elastic groove, a sealing hemisphere is fixedly connected to the top surface of the elastic sheet, a sealing groove is provided on the surface of the screw head on one side close to the threaded rod, a silicone sealing ring is nested and connected to the inner surface wall of the sealing groove, and the screw head and the threaded rod are fixedly connected by the silicone sealing ring and the sealing hemisphere.

6. The expansion screw capable of injecting bone cement according to claim 5, characterized in that: The elastic sheet includes a connected plane section, an arc section and a supporting section. The plane section is a cross-shaped structure. The four ports of the plane section are connected to the supporting section. One end of the supporting section is connected to the arc section. The arc section is fixedly connected to the bottom of the elastic groove. The bottom of the sealing hemisphere is provided with a limit adapter groove that matches the plane section, and the plane section is nested in the limit adapter groove.

7. The expansion screw capable of injecting bone cement according to claim 1, characterized in that: The inner surface wall of the injection head is provided with a sliding ring, and support rods are fixedly connected to both sides of one end of the sliding ring. The bottom end of the support rod is fixedly connected to an extrusion plate, and also includes an extrusion structure for adapting to the sliding of the sliding ring.

8. The expansion screw capable of injecting bone cement according to claim 7, characterized in that: The extrusion structure includes sliding plates fixed on both sides of the top of the sliding ring, the outer wall of the injection head is provided with a sliding opening corresponding to the sliding plates, the outer wall of the injection head is provided with a sliding groove near the bottom of the sliding opening, and the sliding plate passes through the sliding opening and extends to the surface of the sliding groove.

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