Bionic micro-motion adjustable structure pedicle screw

Abstract

The application relates to a bionic micro-motion adjustable structure pedicle screw, which comprises a screw cap with a U-shaped groove and an assembling hole communicated with the U-shaped groove, a rod transversely arranged in the U-shaped groove, a screw plug assembly with a screw plug and a screw plug base, the screw plug being threadedly connected to the groove of the U-shaped groove, the first end of the screw plug base being rotationally connected with the screw plug, the second end of the screw plug base being capable of abutting against the rod under the screwing driving of the screw plug, and a universal screw body with a screw ball head rotationally arranged in the assembling hole. The contact surface between the screw plug and the screw plug base is a spherical surface, the circumferential freedom degree is not limited, the gradual increase of the friction force between the screw plug base and the rod in the screwing process is effectively avoided, the rod is inclined, the rod has swing allowance in two directions, stress accumulation is reduced, and the screw plug is more suitable for human body movement.

Description

Technical Field

[0001] This application belongs to the field of orthopedic medical device technology, specifically relating to a biomimetic micro-motion adjustable pedicle screw. Background Technology

[0002] In spinal fixation surgery, pedicle screws are commonly used medical devices. However, with existing pedicle screws, during the screw insertion process, movement between the screw plug and the rod is unavoidable, easily causing misalignment between the screw plug or rod and the screw head, leading to screw slippage or dislodgement. Furthermore, after the screw plug is locked in place, the screw-rod system is completely fixed, which does not conform to the body's biological movement patterns, such as normal flexion and extension. Prolonged implantation can lead to stress concentration, resulting in risks such as rod breakage and screw plug dislodgement. Summary of the Invention

[0003] In view of the above analysis, the present invention aims to provide a biomimetic micro-motion adjustable pedicle screw to solve the above-mentioned technical problems existing in the prior art.

[0004] The objective of this invention is achieved as follows:

[0005] A biomimetic micro-motion adjustable pedicle screw includes:

[0006] The nail head has a U-shaped groove and an assembly hole communicating with the U-shaped groove;

[0007] A rod is horizontally disposed within the U-shaped groove;

[0008] A plug assembly has a plug and a plug base; the plug is threaded into the opening of the U-shaped groove; a first end of the plug base is rotatably connected to the plug, and a second end of the plug base can abut against the rod under the helical propulsion of the plug;

[0009] The universal nail body has a screw ball head, which is rotatably disposed within the assembly hole.

[0010] Furthermore, it also includes a retaining ring assembly, which is disposed in the U-shaped groove and located between the screw ball and the rod, wherein the two end faces of the retaining ring assembly are respectively matched with the outer peripheral surfaces of the screw ball and the rod.

[0011] Furthermore, the retaining ring assembly has a retaining ring and a retaining ring base; the first end of the retaining ring base abuts against the screw ball head; the first end of the retaining ring can abut against the rod, and the second end of the retaining ring and the second end of the retaining ring base have a first degree of rotational freedom.

[0012] Furthermore, the first end of the retaining ring is provided with a concave arc surface, at least a portion of which matches the circumferential surface of the rod; the second end of the retaining ring is provided with a rotating part, and the second end of the retaining ring base is provided with a rotating fitting part, wherein the rotating part and the rotating fitting part cooperate to give the retaining ring and the retaining ring base a first degree of rotational freedom.

[0013] Furthermore, one of the rotating part and the rotating mating part is an arc-shaped groove, and the other is an arc-shaped protrusion structure, wherein the protrusion structure is capable of rotating within the arc-shaped groove.

[0014] Furthermore, the opening dimensions at both ends of the concave arc surface along the axial direction of the rod are larger than the waist dimension of the concave arc surface, so that the rod has a rotational margin after being fixed by the retaining ring and the screw plug base.

[0015] Furthermore, the rotation angle of the rotation margin is 1°-6°.

[0016] Furthermore, the first end of the screw plug base is provided with an upwardly convex arc surface, and the screw plug is provided with a first concave space, the inner wall surface of the first concave space being adapted to the upwardly convex arc surface; when the screw plug is spirally pushed forward, the upwardly convex arc surface can rotate 0° around the axis of the screw plug within the first concave space.

[0017] Furthermore, the second end of the screw plug base is provided with a second concave space, and a cylinder is provided on the inner wall of the second concave space, the axis of the cylinder being perpendicular or substantially perpendicular to the rod.

[0018] Furthermore, the lower wall of the U-shaped groove is provided with a convex shaft, the axis of which is parallel to the axis of the cylinder; the retaining ring is provided with an arc-shaped groove that is rotatably connected to the convex shaft.

[0019] Furthermore, the arc-shaped groove is provided on the concave arc surface.

[0020] Furthermore, the screw ball head is installed in the assembly hole by a retaining ring; the assembly hole has a retaining groove on its wall, and the retaining ring is installed in the retaining groove.

[0021] Furthermore, the retaining ring is a superior arc ring, and the central angle of the superior arc ring is 330°-350°.

[0022] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0023] a) The biomimetic micro-motion adjustable pedicle screw provided by the present invention uses a plug assembly comprising two rotatably connected parts, namely, the contact surface between the plug and the plug base is spherical, with no circumferential degree of freedom restriction. During the screwing process, after the plug base contacts the rod, it will not rotate relative to the rod. The plug base moves vertically downward, driving the rod to move downward in a straight line, effectively avoiding the rod's deflection caused by the gradual increase of friction between the plug base and the rod during the screw tightening process.

[0024] b) The biomimetic micro-motion adjustable pedicle screw provided by the present invention allows the rod to have a first degree of rotational freedom by rotating the retaining ring and the retaining ring base. Furthermore, by setting the concave arc surface in contact with the retaining ring to a structure with large openings at both ends and a small opening in the middle, the rod can have a certain rotational margin after the screw plug is tightened. The rod has swing margin in both directions, reducing stress accumulation and making it more adaptable to human movement. The screw has a large diameter and a large swing angle.

[0025] c) The biomimetic micro-motion adjustable pedicle screw provided by this invention has a universal screw body that contacts and matches the spherical surface of the retaining ring, ensuring uniform force distribution and a more stable structure. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings.

[0027] Figure 1 A schematic diagram of the biomimetic micro-motion adjustable pedicle screw provided by the present invention;

[0028] Figure 2 An exploded view of the pedicle screw with a biomimetic micro-motion adjustable structure provided by the present invention;

[0029] Figure 3 A schematic cross-sectional view of the pedicle screw with a biomimetic micro-motion adjustable structure provided by the present invention.

[0030] Figure 4 A schematic diagram of the assembly structure of the screw plug and screw plug base provided by the present invention;

[0031] Figure 5 A schematic diagram of the screw plug provided by the present invention;

[0032] Figure 6 This is a schematic diagram of the structure of the screw plug base provided by the present invention;

[0033] Figure 7 A side view of the screw plug base provided by the present invention;

[0034] Figure 8 A schematic diagram of the cross-sectional structure of the screw plug base provided by the present invention;

[0035] Figure 9 A schematic diagram of the assembly structure of the retaining ring and the retaining ring base provided by the present invention;

[0036] Figure 10 This is a schematic diagram of the structure of the retaining ring provided by the present invention;

[0037] Figure 11 This is a schematic diagram of the structure of the retaining ring base provided by the present invention;

[0038] Figure 12 This is a schematic diagram of the structure of the nail head provided by the present invention;

[0039] Figure 13 A partial structural diagram of the nail head provided by the present invention;

[0040] Figure 14 This is a schematic diagram of the structure of the nail head and retaining ring provided by the present invention;

[0041] Figure 15 This is a schematic diagram of the structure of the retaining ring provided by the present invention;

[0042] Figure 16 A schematic diagram illustrating the state of the rod swinging in the first direction of the retaining ring, as provided by the present invention.

[0043] Figure 17 A schematic diagram showing the state of the rod swinging in the second direction of the retaining ring according to the present invention;

[0044] Figure 18 This is a schematic diagram of the swing state of the universal nail body provided by the present invention.

[0045] Figure label:

[0046] 1-Plug; 11-First concave space; 2-Plug base; 21-Upper convex arc surface; 22-Second concave space; 23-Cylinder; 3-Ring; 4-Retaining ring; 41-Arc groove; 42-Concave arc surface; 43-Rotating part; 5-Retaining ring base; 51-Rotating mating part; 52-Spherical concave surface; 6-Clip ring; 7-Nail head; 71-U-groove; 72-Assembly hole; 73-Protruding shaft; 74-Clip groove; 8-Universal nail body; 81-Screw ball head. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0048] To facilitate understanding of the embodiments of this application, the following will provide further explanation and description with reference to the accompanying drawings and specific embodiments. These embodiments do not constitute a limitation on the embodiments of this application.

[0049] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the term "connected" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0050] Throughout the text, the terms “top,” “bottom,” “above,” “below,” and “on top” refer to the relative positions of components of the device, such as the relative positions of the top and bottom substrates within the device. It is understood that the device is multifunctional and independent of its spatial orientation.

[0051] Example 1

[0052] A specific embodiment of the present invention, such as Figures 1 to 3 As shown, a biomimetic micro-motion adjustable pedicle screw is disclosed, comprising:

[0053] The nail head 7 has a U-shaped groove 71 and an assembly hole 72 communicating with the U-shaped groove 71;

[0054] Rod 3 is horizontally disposed within the U-shaped groove 71;

[0055] A screw plug assembly has a screw plug 1 and a screw plug base 2; the screw plug 1 is threadedly connected to the opening of the U-shaped groove 71; the first end of the screw plug base 2 is rotatably connected to the screw plug 1, and the second end of the screw plug base 2 can abut against the rod 3 under the helical propulsion action of the screw plug 1;

[0056] The universal nail body 8 has a screw ball head 81, which is rotatably disposed in the assembly hole 72.

[0057] Compared with the prior art, the biomimetic micro-motion adjustable pedicle screw provided in this embodiment can rotate 360° between the screw plug base 2 and the screw plug. When the screw plug 1 is tightened, the screw plug base 2 is pushed vertically downward to move the pressure bar 3, so that the screw plug base 2 does not rotate, but only advances in a straight line along the axis of the screw plug 1 and presses the bar 3. This effectively avoids the deflection between the screw plug 1 and the bar 3, thereby preventing the screw plug from skipping or coming loose.

[0058] In this implementation, such as Figure 12 As shown, the U-shaped groove 71 is horizontally arranged on the nail head 7 for passing the rod 3 through; the assembly hole 72 is vertically arranged through and communicates with the U-shaped groove 71 for installing the screw ball head 81 of the universal nail body 8.

[0059] Because existing pedicle screws, after implantation, provide a completely fixed screw-rod system (screw, plug, rod), which does not conform to the body's biological movement patterns, prolonged implantation can lead to risks such as rod breakage and plug dislodgement due to stress concentration. Therefore, the biomimetic micro-motion adjustable pedicle screw of this embodiment also includes a retaining ring assembly. The retaining ring assembly is located within the U-shaped groove 71 and between the screw ball head 81 and the rod 3. The two end faces of the retaining ring assembly respectively match the outer peripheral surfaces of the screw ball head 81 and the rod 3. The retaining ring assembly allows the rod 3 to adaptively rotate or swing with the body's movements after implantation, effectively preventing stress concentration that could lead to rod breakage or plug dislodgement.

[0060] Specifically, such as Figures 9 to 11 The retaining ring assembly has a retaining ring 4 and a retaining ring base 5, which are rotatably connected. The first end of the retaining ring base 5 abuts against the screw ball head 81. The retaining ring 4 is disposed above the retaining ring base 5 and has a degree of rotational freedom relative to the retaining ring base 5. The first end of the retaining ring 4 can abut against the rod 3, and the second end of the retaining ring 4 has a first degree of rotational freedom with respect to the second end of the retaining ring base 5.

[0061] In this embodiment, the ball head portion of the universal nail body 8 and the retaining ring base 5 are fitted together via a spherical surface, ensuring uniform force distribution and a more stable structure. Specifically, the first end of the retaining ring base 5 has a spherical concave surface 52, which contacts and engages with the spherical surface of the screw ball head 81, allowing the screw ball head 81 to rotate within the concave surface 52. Figure 18 A schematic diagram of the oscillating state of the universal joint is shown.

[0062] In one alternative embodiment, the first end of the retaining ring 4 is provided with a concave arc surface 42, at least a portion of which matches the circumferential surface of the rod 3; the second end of the retaining ring 4 is provided with a rotating part 43, and the second end of the retaining ring base 5 is provided with a rotating fitting part 51. The rotating part 43 and the rotating fitting part 51 cooperate to give the retaining ring 4 and the retaining ring base 5 a first degree of rotational freedom.

[0063] Furthermore, one of the rotating part 43 and the rotating mating part 51 is an arc-shaped groove, and the other is an arc-shaped protrusion structure, the protrusion structure being able to rotate within the arc-shaped groove.

[0064] In this embodiment, the opening size at both ends of the concave arc surface 42 along the axial direction of the rod 3 is larger than the waist size of the concave arc surface 42, so that the rod 3 has a rotational margin in the second direction after being fixed by the retaining ring 4 and the screw plug base 2.

[0065] Furthermore, the rotation angle of the second direction rotation margin is 1°-6°, which is more suitable for human activity.

[0066] In this embodiment, the first degree of rotational freedom between the retaining ring 4 and the retaining ring base 5 allows the two ends of the rod 3 to rotate up and down in the first rotational direction; the direction of rotation of the rod 3 as it swings left and right on the concave arc surface 42 is the second rotational direction; the second rotational direction is perpendicular or approximately perpendicular to the first rotational direction, that is, after the rod 3 is fixed by the retaining ring 4 and the screw plug base 2, it can swing up and down along the vertical plane, such as... Figure 16 As shown; it can also swing left and right along the horizontal plane, as... Figure 17 As shown. The above structural design allows rod 3 to swing in both directions, reducing stress accumulation and making it more adaptable to human movement.

[0067] In one alternative embodiment, the structure with large openings at both ends of the concave arc surface 42 can be made by using a cutting surface. That is, the first end of the retaining ring 4 is also provided with multiple cutting surfaces, which intersect with the concave arc surface 42. The cutting surfaces make the openings at both ends of the concave arc surface 42 large and the middle opening small. Due to the presence of the cutting surfaces, the two ends of the rod can swing left and right.

[0068] In this implementation, such as Figures 4 to 8As shown, the screw plug 1 and the screw plug base 2 are rotatably connected via an arc-shaped surface. During the tightening process of the screw plug 1, the screw plug base 2 moves vertically downward after contacting the rod 3. Specifically, the first end of the screw plug base 2 is provided with an upwardly convex arc surface 21, and the screw plug 1 is provided with a first concave space 11. The inner wall of the first concave space 11 is adapted to the upwardly convex arc surface 21. When the screw plug 1 is spirally pushed forward, the upwardly convex arc surface 21 can rotate 360° around the axis of the screw plug 1 within the first concave space 11. By rotating the screw plug 1 and the screw plug base 2 via the arc-shaped surface, the screw plug 1 can rotate around its axis without circumferential degree of freedom, ensuring that during the tightening process of the screw plug 1, the screw plug base 2 moves vertically downward to press the rod 3, thus achieving the purpose of preventing the screw plug 1 and the rod 3 from being misaligned.

[0069] In this embodiment, as Figures 7 to 8 As shown, the second end of the screw plug base 2 is provided with a second concave space 22, and a horizontally placed cylinder 23 is provided on the inner wall of the second concave space 22. The axis of the cylinder 23 is perpendicular or substantially perpendicular to the rod 3. Since the outer circumferential surfaces of the rod 3 and the cylinder 23 are both cylindrical structures, the two cylindrical surfaces make point contact when they intersect, which helps to improve the rotational flexibility of the rod 3.

[0070] In one optional embodiment, the lower wall of the U-shaped groove 71 is provided with a convex shaft 73, the axis of which is parallel to the axis of the cylinder 23; the retaining ring 4 is provided with an arc-shaped groove 41 that is rotatably connected to the convex shaft 73. The arc-shaped groove 41 on the upper part of the retaining ring 4 cooperates with the convex shaft 73 on the side of the nail head 7, which can ensure that after the rod 3 is pressed, there is a certain amount of rotation between the rod 3 and the nail head 7.

[0071] Furthermore, the arc-shaped groove 41 is provided on the concave arc surface 42 to facilitate the rapid assembly of the retaining ring 4.

[0072] In this embodiment, as Figures 12 to 14 As shown, the screw ball head 81 is installed in the assembly hole 72 by a retaining ring 6; the wall of the assembly hole 72 is provided with a retaining groove 74, and the retaining ring 6 is installed in the retaining groove 74, which can prevent the retaining ring 4, the retaining ring base 5, and the screw ball head 81 from coming out, thus improving reliability.

[0073] Furthermore, such as Figure 15 As shown, the retaining ring 6 is a curved ring with a central angle of 330°-350°. Setting the retaining ring 6 as a curved ring facilitates assembly.

[0074] In use, the retaining ring 4, retaining ring base 5, and universal nail body 8 are installed sequentially in a bottom-mounted manner, with the retaining ring 6 installed last. After the screw plug 1 and screw plug base 2 are assembled, the nail head 7 is screwed in. During the tightening process, the screw plug base 2 moves vertically downwards to prevent misalignment between the screw plug 1 and the rod 3. After the screw plug 1 is tightened, the lower part of the retaining ring 4 and the retaining ring base 5 can be connected via an arc track. Figure 16 The direction indicated by the middle arrow is n1, which swings; the side of the retaining ring 4 cooperates with the convex shaft 73 of the nail head 7, and the center of the convex shaft 73 is the swing center of the retaining ring 4, while preventing the retaining ring 4 from coming out; after the screw plug 1 is locked, because the two ends of the concave arc surface 42 of the upper part of the retaining ring 4 have room for movement, the rod 3 has Figure 17 The rotation margin of n2 in the direction indicated by the middle arrow.

[0075] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above description is only a specific embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A biomimetic micro-motion adjustable pedicle screw, characterized in that, include: The nail head (7) has a U-shaped groove (71) and an assembly hole (72) communicating with the U-shaped groove (71); A rod (3) is horizontally disposed within the U-shaped groove (71); A screw plug assembly has a screw plug (1) and a screw plug base (2); the screw plug (1) is threadedly connected to the opening of the U-shaped groove (71); the first end of the screw plug base (2) is rotatably connected to the screw plug (1), and the second end of the screw plug base (2) can abut against the rod (3) under the helical propulsion action of the screw plug (1); The universal nail body 8 has a screw ball head (81), which is rotatably disposed in the assembly hole (72); A retaining ring assembly is disposed within the U-shaped groove (71); the retaining ring assembly has a retaining ring (4) and a retaining ring base (5) rotatably connected, the first end of the retaining ring base (5) abuts against the screw ball head (81), the retaining ring (4) is disposed above the retaining ring base (5), the retaining ring (4) has a rotational degree of freedom relative to the retaining ring base (5), the first end of the retaining ring (4) can abut against the rod (3), and the second end of the retaining ring (4) has a first rotational degree of freedom between the second end of the retaining ring (4) and the second end of the retaining ring base (5); The first end of the retaining ring base (5) is provided with a spherical concave surface (52), the screw ball head (81) is in spherical contact with the screw ball head, and the screw ball head can rotate in the spherical concave surface; The first end of the retaining ring (4) is provided with a concave arc surface (42). At least a part of the concave arc surface (42) matches the circumferential surface of the rod (3). The opening size of the two ends of the concave arc surface (42) along the axial direction of the rod (3) is larger than the waist size of the concave arc surface (42), so that after the rod (3) is fixed by the retaining ring (4) and the screw plug base (2), it has a rotation margin in the second direction. The rotation angle of the second rotation margin is 1°~6°.

2. The biomimetic micro-motion adjustable pedicle screw according to claim 1, characterized in that, The second end of the retaining ring (4) is provided with a rotating part (43), and the second end of the retaining ring base (5) is provided with a rotating fitting part (51). The rotating part (43) and the rotating fitting part (51) cooperate to make the retaining ring (4) and the retaining ring base (5) have a first degree of rotational freedom.

3. The biomimetic micro-motion adjustable pedicle screw according to claim 2, characterized in that, One of the rotating part (43) and the rotating mating part (51) is an arc-shaped groove, and the other is an arc-shaped protrusion structure, wherein the protrusion structure is capable of rotating within the arc-shaped groove.

4. The biomimetic micro-motion adjustable pedicle screw according to claim 1, characterized in that, The first end of the screw plug base (2) is provided with an upper convex arc surface (21), and the screw plug (1) is provided with a first concave space (11). The inner wall surface of the first concave space (11) is adapted to the upper convex arc surface (21). When the screw plug (1) is spirally advanced, the convex arc surface (21) can rotate 360° around the axis of the screw plug (1) within the first concave space (11).

5. The biomimetic micro-motion adjustable pedicle screw according to claim 4, characterized in that, The second end of the screw base (2) is provided with a second concave space (22), and a cylinder (23) is provided on the inner wall of the second concave space (22). The axis of the cylinder (23) is perpendicular or substantially perpendicular to the rod (3).

6. The biomimetic micro-motion adjustable pedicle screw according to claim 5, characterized in that, The lower wall of the U-shaped groove (71) is provided with a convex shaft (73), and the axis of the convex shaft (73) is parallel to the axis of the cylinder (23). The retaining ring (4) is provided with an arc-shaped groove (41) that is rotatably connected to the convex shaft (73).

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