Pressing screw and spine internal fixing device

Abstract

The utility model belongs to the technical field of medical instruments, and discloses a compression screw and a spinal internal fixing device. The pressing screw comprises a screw body and an abutting piece, and threads are arranged on the peripheral face of the screw body. The abutting piece is connected with the screw body in a relatively rotating mode, the surface, facing the screw body, of the abutting piece can abut against one end face, in the axis direction, of the screw body, and a plurality of abutting teeth are arranged on the surface, back to the screw body, of the abutting piece. The abutting teeth are used for abutting against a connecting rod of the spine internal fixing device. According to the compression screw and the spine internal fixing device, the probability that the compression screw and the connecting rod slip can be reduced, the effect and stability of fixing the connecting rod can be improved, and the reliability is high.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, in particular to a compression screw and a spinal internal fixation device. Background Art

[0002] Internal fixation technology uses a spinal reduction device for treatment. The spinal reduction device mainly includes a connecting rod and a pedicle screw. The threaded screw body of the pedicle screw is implanted in the spine and fixed to the spine. The screw seat of the pedicle screw is connected to the connecting rod. By adjusting the distance and angle between the pedicle screws, and then locking the pre-bent and deformed connecting rod and the corresponding pedicle screw, the purpose of corrective treatment is achieved.

[0003] In the prior art, a connecting rod is pressed into the pedicle screw by a compression screw to provide a stable fixing effect. The compression screw has an external thread, and the inner wall of the pedicle screw has an internal thread. The compression screw is threadedly connected to the pedicle screw to achieve the limitation of the connecting rod. When the connecting rod is pressed into the pedicle screw by the compression screw, since the surface of the compression screw that contacts the connecting rod is a smooth surface, the friction between the compression screw and the connecting rod is small, and the installation process is more difficult. The operator needs to apply a large external force to the compression screw, which increases the difficulty and time of the operation and reduces the operating efficiency of the internal fixation technology. In addition, since the surface of the compression screw that contacts the connecting rod is relatively smooth, it is easier to slip with the connecting rod, resulting in the compression screw being unable to effectively fix the connecting rod, thereby affecting the stability and reliability of the spinal internal fixation system. Utility Model Content

[0004] The purpose of the utility model is to provide a compression screw and a spinal internal fixation device to solve the technical problems in the prior art of slippage between the compression screw and the connecting rod and low stability and reliability of the spinal internal fixation system.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] Compression screw, including:

[0007] A screw body, wherein the outer peripheral surface of the screw body has an external thread;

[0008] A pressure piece is connected to the screw body for relative rotation, and the surface of the pressure piece facing the screw body can abut against one end face of the screw body in the axial direction. The surface of the pressure piece facing away from the screw body is provided with a plurality of pressure teeth, and the pressure teeth are used to abut against the connecting rod of the spinal internal fixation device.

[0009] Preferably, the tightening screw also includes a connecting shaft, one end of the connecting shaft is connected to the screw body, the other end of the connecting shaft can rotatably pass through the pressure piece, and the outer peripheral surface of the other end of the connecting shaft is provided with a limiting structure, and the limiting structure is used to limit the upper limit of the distance between the pressure piece and the screw body in the axial direction of the screw body.

[0010] Preferably, the surface of the pressing member facing away from the screw body is provided with a first groove, the bottom wall of the first groove is provided with a through hole, the connecting shaft is passed through the through hole, and the end of the connecting shaft facing away from the screw body is located in the first groove, and the limiting structure is located in the first groove.

[0011] Preferably, there is a gap between the limiting structure and the bottom wall of the first groove.

[0012] Preferably, a second groove is provided on an end surface of the screw body facing away from the pressing member, and the connecting shaft extends along the axial direction of the screw body to the bottom of the second groove.

[0013] Preferably, the pressing member is coaxially arranged with the screw body.

[0014] Preferably, the pressing teeth are cylindrical, conical, prismatic, pyramidal or hemispherical structures; and / or the cross section of the pressing member is circular, elliptical, polygonal or fan-shaped.

[0015] Preferably, the surface of the pressing member facing the screw body is a plane; and / or the surface of the screw body facing the pressing member is a plane.

[0016] The spinal internal fixation device includes a pedicle screw and a connecting rod. The spinal internal fixation device also includes the tightening screw as described above. The connecting rod is arranged in the U-shaped nail seat of the pedicle screw. The tightening screw is arranged in the U-shaped nail seat and is pressed against the connecting rod, and the pressing tooth abuts against the connecting rod.

[0017] Preferably, the surface of the connecting rod used to abut against the pressing tooth is provided with a third groove, and the pressing tooth can be stuck in the third groove.

[0018] The camming mechanism of the present invention is such that the camming mechanism of the present invention is such that the camming mechanism of the present invention is such that the camming mechanism of the present invention is such that the camming mechanism of the present invention is such that the camming mechanism of the present invention is such that the camming mechanism of the present invention is such that the camming mechanism of the present invention is such that the camming mechanism of the present invention is such that the camming mechanism of the present invention is such that the camming mechanism of the present invention is such that the camming mechanism of the present invention is such that the camming mechanism of the present invention is

[0019] Moreover, after the screw body is assembled in place, the screw body will still apply a large force to the pressure piece, so that the pressure teeth on the pressure piece can still be tightly pressed on the connecting rod, avoiding the problem of slipping between the connecting rod and the tightening screw after assembly, so that the tightening screw can effectively fix the connecting rod, thereby improving the stability and reliability of the spinal internal fixation device using the compression screw. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of a compression screw provided by an embodiment of the present utility model;

[0021] Figure 2 This is an exploded view of the compression screw provided by an embodiment of the present utility model;

[0022] Figure 3 is a cross-sectional view of a compression screw provided by an embodiment of the present utility model;

[0023] Figure 4 This utility model Figure 3 The enlarged view of point A is shown;

[0024] Figure 5 It is a cross-sectional view of the pressing member provided by an embodiment of the present utility model;

[0025] Figure 6 It is a top view of the compression screw provided in an embodiment of the utility model.

[0026] In the picture:

[0027] 100. Screw body; 110. External thread; 120. Second groove; 130. First end face; 140. Second end face; 200. Pressing member; 210. Pressing tooth; 220. First groove; 230. Through hole; 300. Connecting shaft; 310. Limiting structure; 400. Gap. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0029] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0030] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0031] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0032] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0033] First, this embodiment provides a compression screw, which is used in a spinal internal fixation device and is used to abut against a connecting rod. It can reduce the probability of slipping between the compression screw and the connecting rod, making it easier for the operator to press the connecting rod into the pedicle screw of the spinal internal fixation device through the compression screw, thereby reducing the difficulty of operation, improving the operating efficiency, and improving the effect and stability of fixing the connecting rod, so as to have higher reliability.

[0034] like Figures 1 to 6 As shown, the compression screw includes a screw body 100 and a pressure member 200. The outer circumference of the screw body 100 has external threads 110 for connection to the pedicle screw. The screw body 100 is cylindrical and includes a first end face 130 and a second end face 140 disposed opposite each other along its axis. The pressure member 200 is located on the side of the first end face 130 facing away from the second end face 140.

[0035] The pressure member 200 in this embodiment is connected to the screw body 100 so as to be relatively rotatable. That is, the pressure member 200 can rotate relative to the screw body 100, or the screw body 100 can also rotate relative to the pressure member 200, so that when the screw body 100 is screwed to the pedicle screw, the pressure member 200 does not rotate with the screw body 100. The surface of the pressure member 200 facing the screw body 100 can abut against an end face (i.e., the first end face 130) of the screw body 100 in the axial direction, so as to transmit external forces applied to the screw body 100 to the pressure member 200. The surface of the pressure member 200 facing away from the screw body 100 is provided with a plurality of pressure teeth 210, which are used to abut against the connecting rod of the spinal internal fixation device to increase the friction between the pressure member 200 and the connecting rod.

[0036] The compression screw provided in this embodiment is connected to the screw body 100 in a relatively rotatable manner, and the pressing teeth 210 of the pressing piece 200 facing away from the screw body 100 abut against the connecting rod, so that when the screw body 100 rotates, the pressing piece 200 will not be driven to rotate. Therefore, the increased friction between the pressing teeth 210 and the connecting rod will not affect the screw connection of the screw body 100 in the pedicle screw, ensuring the normal assembly of the compression screw. The surface of the pressing piece 200 facing the screw body 100 abuts against the first end face 13 of the screw body 100. 0 abutment, so that the external force applied to the screw body 100 can be transmitted to the pressing piece 200, and then to the pressing teeth 210, so that the pressing teeth 210 are pressed on the connecting rod, which increases the friction between the pressing piece 200 and the connecting rod, reduces the probability of slipping between the pressing piece 200 and the connecting rod, and thus reduces the probability of slipping between the tightening screw and the connecting rod, so that the operator does not need to use a large force when pressing the connecting rod into the pedicle screw through the tightening screw, reduces the difficulty of operation during the assembly process, and thus can improve the assembly efficiency.

[0037] Moreover, after the screw body 100 is assembled in place, the screw body 100 will still apply a large force to the pressing piece 200, so that the pressing teeth 210 on the pressing piece 200 can still be tightly pressed on the connecting rod, avoiding the problem of slipping between the connecting rod and the tightening screw after assembly, so that the tightening screw can effectively fix the connecting rod, thereby improving the stability and reliability of the spinal internal fixation device using the tightening screw.

[0038] In some optional embodiments, the pressing member 200 and the pressing tooth 210 are an integrated structure, which improves the integrity of the pressing member 200. Of course, it is understandable that the pressing member 200 and the pressing tooth 210 can also be a separate structure, which is not limited in this embodiment.

[0039] For example, a plurality of pressing teeth 210 are evenly distributed on the surface of the pressing member 200 facing away from the screw body 100 to improve the uniformity of the pressure applied to the connecting rod and further reduce the risk of slippage between the connecting rod and the pressing member 200. In this embodiment, the pressing teeth 210 are distributed over the entire surface of the pressing member 200 facing the connecting rod, thereby fully utilizing the surface of the pressing member 200 facing the connecting rod and increasing the number of pressing teeth 210, thereby increasing the contact area between the pressing member 200 and the connecting rod.

[0040] Alternatively, as Figure 2 As shown, the compression screw further includes a connecting shaft 300. The screw body 100 and the pressure member 200 are connected via the connecting shaft 300. One end of the connecting shaft 300 is connected to the screw body 100. For example, the connecting shaft 300 can be welded to the screw body 100. In some optional embodiments, to enhance the connection strength between the connecting shaft 300 and the screw body 100, the screw body 100 is provided with a through-hole (not shown in the figure), and one end of the connecting shaft 300 is inserted into the through-hole and connected to the wall of the through-hole.

[0041] The other end of the connecting shaft 300 rotatably passes through the pressing member 200. That is, the connecting shaft 300 can rotate, and the pressing member 200 does not rotate with the rotation of the connecting shaft 300. In addition, a limiting structure 310 is provided on the outer circumference of the other end of the connecting shaft 300. The limiting structure 310 is used to limit the upper limit of the distance between the pressing member 200 and the screw body 100 in the axial direction of the screw body 100, thereby achieving the connection between the screw body 100 and the pressing member 200. By limiting the distance between the pressing member 200 and the screw body 100 by the limiting structure 310, it can be ensured that the screw body 100 can transmit external force to the pressing member 200, thereby enabling the pressing member 200 to be better pressed onto the connecting rod.

[0042] In some optional embodiments, the limiting structure 310 is an annular protrusion provided on the outer circumference of the connecting shaft 300 to ensure the limiting effect. Of course, it is understandable that there can also be multiple limiting structures 310, and multiple limiting structures 310 are provided at intervals along the circumference of the connecting shaft 300 to also achieve the limiting effect on the pressing member 200.

[0043] For example, Figure 5 As shown, the surface of the pressing member 200 facing away from the screw body 100 is provided with a first groove 220. The depth of the first groove 220 is aligned with the axis of the screw body 100. The bottom wall of the first groove 220 is provided with a through hole 230. The through hole 230 extends to the surface of the pressing member 200 facing the screw body 100. The connecting shaft 300 is inserted through the through hole 230, so that the other end of the connecting shaft 300 can be positioned in the first groove 220. The retaining structure 310 is positioned in the first groove 220. That is, the retaining structure 310 is connected to the portion of the connecting shaft 300 located in the first groove 220. By providing the first groove 220, the retaining structure 310 and the connecting shaft 300 do not protrude from the surface of the pressing member 200 facing away from the screw body 100, thereby preventing the connection between the pressing teeth 210 and the connecting rod from being affected, thereby improving the functional reliability of the compression screw.

[0044] In some optional embodiments, in order to avoid the screw body 100 and the connecting shaft 300 from generating large friction with the pressing member 200 when the screw body 100 and the connecting shaft 300 rotate, in this embodiment, as shown in FIG. Figure 4 As shown, there is a gap 400 between the limiting structure 310 and the bottom wall of the first groove 220. The gap 400 allows the pressing member 200 to move relative to the connecting shaft 300 in the axial direction of the connecting shaft 300, that is, it can move relative to the limiting structure 310 and the screw body 100. In this way, when the screw body 100 is screwed, the pressing member 200 and the limiting structure 310, as well as the pressing member 200 and the first end face 130, will not be tightly abutted, and thus will not affect the rotation of the screw body 100.

[0045] Before the pressing member 200 contacts the connecting rod, when the screw body 100 is screwed, the pressing member 200 moves under the action of its own gravity, and the bottom wall of the first groove 220 contacts the limiting structure 310. There is a gap between the surface of the pressing member 200 facing the first end face 130 and the first end face 130. At this time, the pressing member 200 can rotate with the limiting structure 310 or can not rotate with the limiting structure 310. When the pressing teeth 210 of the pressing member 200 contact the connecting rod, as the screw body 100 continues to be screwed, the connecting shaft 300 moves relative to the pressing member 200 in the axial direction of the connecting shaft 300 until the surface of the pressing member 200 facing the first end face 130 abuts against the first end face 130. At this time, there is the above-mentioned gap 400 between the bottom wall of the first groove 220 and the limiting structure 310. The pressing member 200 is in a state of abutting against the first end face 130, so that the pressing teeth 210 can closely contact the connecting rod, thereby reducing the probability of the connecting rod sliding relative to the pressing member 200.

[0046] In some optional embodiments, a second groove 120 is provided on the end face of the screw body 100 facing away from the pressing member 200 (i.e., the second end face 140), and the connecting shaft 300 extends along the axial direction of the screw body 100 to the bottom of the second groove 120, so as to facilitate the connection between the connecting shaft 300 and the screw body 100, improve the connection strength between the two, and reduce the manufacturing difficulty of the pressing screw. In this embodiment, the second groove 120 is used to cooperate with a screwing tool to facilitate driving the screw body 100 to rotate. The shape of the second groove 120 can be "rice" shaped, "cross" shaped, flower shaped or other shapes, and this embodiment does not limit this.

[0047] Optionally, in this embodiment, as Figure 3 shown, the pressing member 200 and the screw body 100 are coaxially arranged. For example, the axes of the pressing member 200 and the screw body 100 are L, so that the screw body 100 can evenly transfer the external force to the pressing member 200, thereby ensuring the uniformity of the force exerted by the pressing member 2C on the connecting rod, preventing the pressing member from slipping relative to the connecting rod due to the application point deviating from the axis of the connecting rod, further reducing the operation difficulty in the assembly process, and thus being able to improve the assembly efficiency. It also further effectively fixes the connecting rod, improving the stability and reliability of the spinal internal fixation device using the pressing screw.

[0048] Exemplarily, the surface of the pressing member 200 facing the screw body 100 is a plane, and the surface of the screw body 100 facing the pressing member 200 is a plane, so that the pressing member 200 and the screw body 100 have a large contact area, thereby ensuring the stability and reliability of the screw body 100 transferring the external force to the pressing member 200, and further ensuring the uniform force on the connecting rod.

[0049] In some optional embodiments, there may be an uneven structure on the connecting rod, and the pressing tooth 210 may be placed in the uneven structure to achieve the connection between the connecting rod and the pressing tooth 210, further increasing the friction between the connecting rod and the pressing tooth 210 to prevent relative movement between the two.

[0050] For example, Figure 2 As shown, the pressing tooth 210 is a pyramid ring structure, specifically, the pressing tooth 210 is a triangular pyramid, and one tip of the pressing tooth 210 is set toward the connecting rod and is used to abut against the connecting rod. Specifically, one tip of the pressing tooth 210 can be placed in an uneven structure.

[0051] It is understandable that the pressing tooth 210 may also be a cylindrical structure, a conical structure, a prismatic structure, a hemispherical structure or other shapes, which is not limited in this embodiment.

[0052] In some optional embodiments, such as Figure 2 As shown, the cross section of the pressing member 200 is circular, so that the pressing member 200 can have a larger area for arranging the pressing teeth 210 , thereby allowing a larger number of pressing teeth 210 .

[0053] It is understandable that the cross section of the pressing member 200 may also be elliptical, polygonal, fan-shaped, etc., which is not limited in this embodiment.

[0054] Secondly, this embodiment also provides a spinal internal fixation device that is easy to operate and has high stability.

[0055] Specifically, the spinal internal fixation device includes a pedicle screw (not shown in the figure), a connecting rod (not shown in the figure) and a compression screw. The compression screw is the compression screw in the first aspect.

[0056] The connecting rod is located within the U-shaped seat of the pedicle screw, and the compression screw is located within the U-shaped seat and crimped onto the connecting rod. The U-shaped seat has internal threads, and the external threads 110 of the compression screw are threadedly engaged with the internal threads to connect the compression screw to the U-shaped seat. The pressing teeth 210 abut against the connecting rod to prevent it from shaking.

[0057] The spinal internal fixation device provided in this embodiment has a pressing screw provided with a pressing piece 200, and a pressing tooth 210 is provided on the surface of the pressing piece 200 facing away from the screw body 100. The pressing tooth 210 abuts against the connecting rod, so that the pressing tooth 210 is pressed against the connecting rod, which increases the friction between the pressing piece 200 and the connecting rod, reduces the probability of slipping between the pressing piece 200 and the connecting rod, and further reduces the probability of slipping between the pressing screw and the connecting rod, so that the operator does not need to use a lot of force when pressing the connecting rod into the pedicle screw through the pressing screw, reduces the difficulty of operation during the assembly process, and thus can improve the assembly efficiency.

[0058] Optionally, a third groove is provided on the surface of the connecting rod for contact with the pressing tooth 210, and the pressing tooth 210 can be inserted into the third groove to further prevent the pressing tooth 210 from sliding relative to the connecting rod, thereby ensuring the relative position of the pressing member 200 and the connecting rod, and avoiding the problem of slipping between the connecting rod and the tightening screw after assembly, so that the tightening screw can effectively fix the connecting rod, thereby improving the stability and reliability of the spinal internal fixation device.

[0059] It should be noted that the width and depth of the third groove may be smaller to avoid affecting the structural strength of the connecting rod.

[0060] The spinal internal fixation device provided in this embodiment has a connecting shaft 300 and a pressing member 200 added to the bottom of the screw body 100. The screw body 100 and the pressing member 200 are assembled via the connecting shaft 300. The downward pressure of the compression screw tightly connects the pressing teeth 210 and the connecting rod, preventing the connecting rod from slipping. This ensures that the compression screw can effectively secure the connecting rod, thereby improving the stability and reliability of the spinal internal fixation device.

[0061] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Compression screw, characterized in that, include: A screw body (100), wherein the outer peripheral surface of the screw body (100) has an external thread (110); A pressing member (200) is connected to the screw body (100) in a relatively rotatable manner, and the surface of the pressing member (200) facing the screw body (100) can abut against an end face of the screw body (100) in the axial direction. A plurality of pressing teeth (210) are provided on the surface of the pressing member (200) facing away from the screw body (100), and the pressing teeth (210) are used to abut against a connecting rod of a spinal internal fixation device.

2. The compression screw according to claim 1, wherein: The tightening screw also includes a connecting shaft (300), one end of which is connected to the screw body (100), and the other end of which is rotatably passed through the pressing member (200), and the outer peripheral surface of the other end of the connecting shaft (300) is provided with a limiting structure (310), and the limiting structure (310) is used to limit the upper limit of the distance between the pressing member (200) and the screw body (100) in the axial direction of the screw body (100).

3. The compression screw according to claim 2, wherein: A first groove (220) is provided on the surface of the pressing member (200) facing away from the screw body (100), a through hole (230) is provided on the bottom wall of the first groove (220), the connecting shaft (300) is passed through the through hole (230), and the end of the connecting shaft (300) facing away from the screw body (100) is located in the first groove (220), and the limiting structure (310) is located in the first groove (220).

4. The compression screw according to claim 3, wherein: There is a gap (400) between the limiting structure (310) and the bottom wall of the first groove (220).

5. The compression screw according to claim 2, wherein: A second groove (120) is provided on the end surface of the screw body (100) facing away from the pressing member (200), and the connecting shaft (300) extends along the axial direction of the screw body (100) to the bottom of the second groove (120).

6. The compression screw according to any one of claims 1 to 5, characterized in that: The pressing member (200) is coaxially arranged with the screw body (100).

7. The compression screw according to any one of claims 1 to 5, characterized in that: The pressing teeth (210) are cylindrical, conical, prismatic, pyramidal, or hemispherical structures; and / or the cross section of the pressing member (200) is circular, elliptical, polygonal, or fan-shaped.

8. The compression screw according to claim 1, wherein: The surface of the pressing member (200) facing the screw body (100) is a plane; and / or the surface of the screw body (100) facing the pressing member (200) is a plane.

9. A spinal fixation device comprising a pedicle screw and a connecting rod, characterized in that: The spinal internal fixation device also includes a compression screw as described in any one of claims 1 to 8, the connecting rod is arranged in the U-shaped nail seat of the pedicle screw, the compression screw is arranged in the U-shaped nail seat and pressed against the connecting rod, and the pressing tooth (210) is in contact with the connecting rod.

10. The spinal internal fixation device according to claim 9, characterized in that: A third groove is provided on the surface of the connecting rod for contacting with the pressing tooth (210), and the pressing tooth (210) can be inserted into the third groove.

Images