A universal pedicle screw

Abstract

The present invention relates to a universal pedicle screw, comprising a screw seat, a bone screw, and an intermediate body. The screw seat has a U-shaped groove at one end and a through hole at the other end, wherein the through hole has an angled structure at the end away from the U-shaped groove. The bone screw comprises a screw body and a pair of C-shaped hemispherical rings, which are detachably mounted on the head of the screw body. The intermediate body is disposed within the screw seat. The screw body penetrates the screw seat from the end where the through hole is located and cooperates with the C-shaped hemispherical rings located within the through hole. The present invention has a simple structure, is easy to assemble, has an unrestricted screw body diameter, and has a large swing angle, thus meeting the requirements of pedicle screws in special surgical situations.

Description

Technical Field

[0001] The invention belongs to the technical field of orthopedic medical instruments, and in particular relates to a universal pedicle screw. Background Art

[0002] The pedicle screws currently used for posterior spinal screw-rod fixation surgery are mainly uniaxial pedicle screws and universal pedicle screws. Universal pedicle screws are the most commonly used in clinical practice because they facilitate the installation of connecting rods during surgery. Currently, universal screws mostly use a top-loading process, that is, the bone screw is installed from the end where the U-shaped groove of the screw seat is located. In order to ensure that the bone screw does not fall out from under the screw seat and to ensure the strength of the screw seat, the bottom hole of the bone screw under the screw seat is not designed to be too large. As a result, the diameter of the bone screw in this assembly is not very large, the diameter size is limited, and the swing angle of the bone screw is generally less than 25°. The above characteristics have led to the universal screw being unable to meet some special needs in clinical practice. For example, the fixation of the sacroiliac joint during spinal correction surgery requires screws with large deflection angles and thick diameters. Summary of the Invention

[0003] The purpose of the present invention is to provide a universal pedicle screw to solve the problem of limited diameter of bone screws.

[0004] A universal pedicle screw of the present invention is achieved as follows:

[0005] A universal pedicle screw, comprising

[0006] A screw seat, wherein one end of the screw seat has a U-shaped groove and the other end has a through hole, and the end of the through hole away from the U-shaped groove is an angled structure;

[0007] A bone screw comprising a screw body and a pair of C-shaped hemispherical rings, wherein the C-shaped hemispherical rings are detachably mounted on the head of the screw body;

[0008] an intermediate body, the intermediate body being disposed in the screw seat;

[0009] The nail body penetrates into the screw seat from the end where the through hole of the screw seat is located and cooperates with the C-shaped hemispherical ring located in the through hole.

[0010] Furthermore, a mounting portion is provided on the top of the nail body, a conical step is provided on the mounting portion, and a conical groove matching the conical step is provided on the inner annular surface of the C-shaped hemispherical ring.

[0011] Furthermore, the outer diameter of the upper end of the tapered step is smaller than the outer diameter of the lower end thereof.

[0012] Furthermore, an annular inner groove is provided on the inner wall of the end portion of the through hole facing the U-shaped groove, and the end away from the U-shaped groove is an angled hole.

[0013] Furthermore, the deflection angle between the axial direction of the angled hole and the axial direction of the screw seat is 7°-23°.

[0014] Further preferably, the deflection angle α is 15°.

[0015] Furthermore, the inner diameter of the bottom of the angled hole is larger than the outer diameter of the mounting portion, and smaller than the outer diameter of the ball head formed by the two C-shaped hemispherical rings.

[0016] Furthermore, the intermediate body is an annular structure, and a C-shaped groove is provided on the top thereof.

[0017] Furthermore, a limiting step is provided on the top outer ring surface of the C-shaped hemispherical ring, and the limiting step cooperates with the bottom of the intermediate body.

[0018] Furthermore, rivet holes are provided on both side outer walls of the screw seat, and recesses corresponding to the rivet holes are provided on both side outer walls of the intermediate body.

[0019] Furthermore, the inner walls on both sides of the U-shaped groove are concave arc surfaces, and internal threads are provided on the inner walls.

[0020] After adopting the above technical solution, the present invention has the following beneficial effects:

[0021] (1) The nail body and ball head of the bone screw of the present invention adopt a split design, which allows the nail body to be installed from the end where the screw seat through hole is located, and the ball head composed of a pair of C-shaped hemispherical rings is used to lock it in the screw seat. The assembly is convenient and simple, and the diameter of the nail body is not limited, which can meet the needs of bone screws of different specifications.

[0022] (2) The present invention is provided with an angled structure, which can increase the swing angle of the bone screw. The swing angle in the angled direction can be increased to 50°, which can well meet the fixation of the sacroiliac joint, thereby increasing the application range of the pedicle screw. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings and examples.

[0024] Figure 1 1 is a structural diagram of a universal pedicle screw according to a preferred embodiment of the present invention;

[0025] Figure 2 is an exploded view of a universal pedicle screw according to a preferred embodiment of the present invention;

[0026] Figure 3 is a cross-sectional view of a sagittal plane of a universal pedicle screw according to a preferred embodiment of the present invention;

[0027] Figure 4 yes Figure 3 Enlarged view of part A;

[0028] Figure 5 is a cross-sectional view of a universal pedicle screw in a horizontal plane according to a preferred embodiment of the present invention;

[0029] Figure 6 yes Figure 5 Enlarged view of part B;

[0030] Figure 7 is a cross-sectional view in the horizontal direction of the screw head of a universal pedicle screw according to a preferred embodiment of the present invention;

[0031] Figure 8 1 is a structural diagram of a universal pedicle screw body according to a preferred embodiment of the present invention;

[0032] Figure 9 1. It is a structural diagram of a C-shaped hemispherical ring of a universal pedicle screw according to a preferred embodiment of the present invention;

[0033] Figure 10 1 is a structural diagram of an intermediate body of a universal pedicle screw according to a preferred embodiment of the present invention;

[0034] Figure 11 is a cross-sectional view in the horizontal plane of a universal pedicle screw in a large-angle swing state according to a preferred embodiment of the present invention;

[0035] In the figure: screw seat 1, U-shaped groove 11, through hole 12, inner groove 13, angled hole 14, rivet hole 15, internal thread 16, bone screw 2, nail body 21, C-shaped hemispherical ring 22, mounting portion 23, tapered step 24, tapered groove 25, limiting step 26, upper step 27, intermediate body 3, C-shaped groove 31, spherical surface 32, countersunk groove 33. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0038] like Figure 1-11As shown, a universal pedicle screw includes a screw seat 1, a bone screw 2 and an intermediate body 3. One end of the screw seat 1 has a U-shaped groove 11 and the other end has a through hole 12. The end of the through hole 12 away from the U-shaped groove 11 is an angled structure; the bone screw 2 includes a nail body 21 and a pair of C-shaped hemispherical rings 22, and the C-shaped hemispherical rings 22 are detachably mounted on the head of the nail body 21; the intermediate body 3 is arranged in the screw seat 1; the nail body 21 penetrates into the screw seat 1 from the end where the through hole 12 of the screw seat 1 is located and cooperates with the C-shaped hemispherical rings 22 located in the through hole 12.

[0039] In order to achieve the cooperation between the C-shaped hemispherical ring 22 and the nail body 21, a mounting portion 23 is provided on the top of the nail body 21, and a conical step 24 is provided on the mounting portion 23. A conical groove 25 that cooperates with the conical step 24 is provided on the inner ring surface of the C-shaped hemispherical ring 22.

[0040] Specifically, the two C-shaped hemispherical rings 22 are relatively clamped on the outside of the mounting portion 23, and the conical step 24 is clamped into the conical groove 25, and the two C-shaped hemispherical rings 22 form a ball head structure.

[0041] In order to prevent the nail body 21 from falling out of the C-shaped hemispherical ring 22, the outer diameter of the upper end of the tapered step 24 is smaller than the outer diameter of the lower end thereof.

[0042] Since the conical groove 25 cooperates with the conical step 24, the inner diameter of the bottom of the conical groove 25 is larger than the inner diameter of its top. The conical groove 25 can confine the conical step 24 therein, preventing the nail body 21 from separating from the C-shaped hemispherical ring 22, thereby preventing the nail body 21 from falling off the screw seat 1, and ensuring the stability of the connection between the bone screw 2 and the screw seat 1.

[0043] And due to the setting of the tapered groove 25 and the tapered step 24, when the pedicle screw is assembled, the nail body 21 can directly stretch the two C-shaped hemispherical rings 22 when it is installed from below the C-shaped hemispherical ring 22. After the nail body 21 is installed in place, the C-shaped hemispherical ring 22 will automatically be clamped on the outside of the mounting portion 23 of the nail body 21, thereby realizing rapid assembly of the nail body 21 and the C-shaped hemispherical ring, and improving the assembly efficiency of the pedicle screw.

[0044] In order to facilitate the matching between the C-shaped hemispherical ring 22 and the nail body 21 , an annular inner groove 13 is provided on the inner wall of the end portion of the through hole 12 facing the U-shaped groove 11 .

[0045] Preferably, the inner diameter of the through hole 12 at the inner groove 13 is larger than the outer diameter of the ball head formed by the two C-shaped hemispherical rings 22 .

[0046] When matching the C-shaped hemispherical ring 22 with the nail body 21, the two C-shaped hemispherical rings 22 can be placed relative to each other in the inner groove 13 first, and the mounting portion 23 of the nail body 21 is inserted from the bottom of the through hole 12. As the mounting portion 23 is inserted, the two C-shaped hemispherical rings 22 are separated. When the mounting portion 23 is located between the two C-shaped hemispherical rings 22, the conical grooves 25 of the two C-shaped hemispherical rings 22 and the conical steps 24 on the mounting portion 23 will automatically engage. Then the intermediate body 3 is installed on the screw seat 1, and the rivet hole 15 on the screw seat 1 is riveted using a riveting tool so that the intermediate body 3 cannot be separated from the screw seat 1, thereby completing the assembly of the pedicle screw.

[0047] In addition, the setting of the inner groove 13 can also facilitate the ball head composed of the two C-shaped hemispherical rings 22 to follow the rotation of the nail body 21, and the ball head can also rotate in the angled hole 14 without falling off from the bottom of the angled hole 14.

[0048] In order to adjust the swing angle of the bone screw 2 , one end of the through hole 12 away from the U-shaped groove 11 is an angled hole 14 .

[0049] In order to increase the swing deflection angle of the bone screw 2, the deflection angle α between the axial direction of the deflection hole 14 and the axial direction of the screw seat 1 is 7°-23°.

[0050] Preferably, the deflection angle α is 15°, which can meet the large deflection angle required by most clinical situations and can reduce the processing difficulty accordingly.

[0051] Specifically, the swing angle of the bone screw 2 toward its deflection direction can be increased to 50°, and the swing angle toward the opposite direction of the deflection angle can also reach 10°, thereby meeting the special requirements for pedicle screws with large deflection angles.

[0052] The direction and angle of the deflection angle can be selected according to the specific use situation. In this embodiment, the deflection angle is located in the horizontal plane direction.

[0053] The function of the two C-shaped hemispherical rings 22 is to drive the nail body 21 to swing, and can also be used to connect the nail body 21 with the screw seat 1. In order to facilitate the installation of the C-shaped hemispherical rings 22, the nail body 21 and the screw seat 1, the bottom inner diameter of the angled hole 14 is larger than the outer diameter of the mounting portion 23, and smaller than the outer diameter of the ball head formed by the two C-shaped hemispherical rings 22.

[0054] Specifically, the outer diameter of the mounting portion 23 is smaller than the inner diameter of the angled hole 14, which can facilitate the installation of the nail body 21 into the screw seat 1 from the bottom of the through hole 12, and the diameter of the ball head composed of the two C-shaped hemispherical rings 22 is larger than the inner diameter of the angled hole 14, preventing the C-shaped hemispherical rings 22 from falling off from the bottom of the through hole 12, thereby ensuring a stable connection between the nail body 21 and the screw seat 1.

[0055] In order to facilitate the installation of the connecting rod, the intermediate body 3 is an annular structure, and a C-shaped groove 31 is provided on the top thereof.

[0056] When the pedicle screw is connected to the connecting rod, in order to ensure the fit between it and the connecting rod, a C-shaped groove 31 is provided to fit with the outer ring surface of the connecting rod. During installation, the connecting rod is placed in the C-shaped groove 31 to ensure that the force on each fitting part is uniform.

[0057] In order to achieve the matching between the C-shaped hemispherical ring 22 and the intermediate body 3 , a limiting step 26 is provided on the top outer ring surface of the C-shaped hemispherical ring 22 , and the limiting step 26 matches the limiting step 26 at the bottom of the intermediate body 3 .

[0058] Specifically, a spherical surface 32 is provided at the bottom of the inner ring surface of the intermediate body 3, and the inner diameter of the top end of the spherical surface 32 is smaller than the inner diameter of its bottom end, and the two C-shaped hemispherical rings 22 are ringed on the outside of the mounting part 23 of the nail body 21, and the top of the mounting part 23 and the top of the C-shaped hemispherical ring 22 extend into the interior of the intermediate body 3 and cooperate with the spherical surface 32.

[0059] Specifically, the top outer ring of the mounting portion 23 is provided with an upper step 27. The four steps formed by the upper surface of the mounting portion 23, the upper step 27, the upper surface of the C-shaped hemispherical ring 22 and the limiting step 26 are located within the same spherical surface 32 at the bottom of the intermediate body 3. During assembly, the position of the intermediate body 3 is simultaneously restricted so that the recessed groove 33 on the side of the intermediate body 3 is in the riveted position.

[0060] During clinical surgery, when the pedicle screw is locked, the four-step arrangement consisting of the upper surface of the mounting portion 23, the upper step 27, the upper surface of the C-shaped hemispherical ring 22, and the limiting step 26 can ensure that the intermediate body 3 firmly holds the bone screw 2, so that the bone screw 2 has sufficient strength to support the biological load of the vertebral body and prevent the loss of vertebral height due to loose locking of the bone screw 2.

[0061] In order to prevent the intermediate body 3 from falling off from the screw seat 1 , rivet holes 15 are provided on both side outer walls of the screw seat 1 , and recesses 33 corresponding to the rivet holes 15 are provided on both side outer walls of the intermediate body 3 .

[0062] Preferably, the rivet hole 15 is a blind hole.

[0063] Specifically, the rivet hole 15 on the screw seat 1 is punched by a riveting tool, so that the inner wall of the rivet hole 15 is deformed inward to form an inner protrusion, and the inner protrusion is fitted into the recess 33 of the intermediate body 3, thereby preventing the intermediate body from falling out.

[0064] In order to facilitate the fixing of the connecting rod, the inner walls on both sides of the U-shaped groove 11 are concave arc surfaces, and the inner walls are provided with internal threads 16.

[0065] The connecting rod is inserted into the U-shaped groove 11 of the screw seat 1 and placed in the C-shaped groove 31 of the intermediate body 3. Then, a locking screw is screwed into the top of the U-shaped groove 11 to cooperate with the internal thread 16 to fix the connecting rod.

[0066] When assembling the pedicle screw, first, the two C-shaped hemispherical rings 22 are installed in the inner grooves 13 of the screw seat 1 in sequence, and then the mounting portion 23 of the nail body 21 is installed in the screw seat 1 from bottom to top from the bottom of the through hole 12 and penetrated between the two C-shaped hemispherical rings 22, and the C-shaped hemispherical rings 22 are clamped in the periphery of the mounting portion 23, so that the tapered grooves 25 of the C-shaped hemispherical rings 22 and the tapered steps 24 on the mounting portion 23 cooperate well, and then the intermediate body 3 is installed from the top of the screw seat 1, and the bottom of the intermediate body 3 is clamped on the step at the top of the C-shaped hemispherical ring 22. After confirming that the assembly is correct, the rivet hole 15 on the screw seat 1 is punched using a riveting tool, so that the inner wall of the rivet hole 15 is deformed to form an inner bulge, which is matched in the sinking groove 33 of the intermediate body 3 to prevent the intermediate body 3 from coming out of the screw seat 1, thereby completing the assembly of the entire pedicle screw.

[0067] The overall structure of the present invention is simple and easy to assemble. The diameter of the nail body 21 can be selected as needed without size restrictions. In addition, the design of the angled hole 14 can increase the swing angle of the bone screw 2. The direction and size of the swing angle can be selected as needed. When in use, the various parts cooperate well, the force is evenly distributed, and the structure is stable. It is suitable for use in special occasions such as sacroiliac joint fixation surgery.

[0068] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A universal pedicle screw, characterized in that: include A screw seat (1), wherein one end of the screw seat (1) has a U-shaped groove (11), and the other end has a through hole (12), and the end of the through hole (12) away from the U-shaped groove (11) is an angled structure; A bone screw (2), comprising a nail body (21) and a pair of C-shaped hemispherical rings (22), wherein the C-shaped hemispherical rings (22) are detachably mounted on the head of the nail body (21); An intermediate body (3), the intermediate body (3) being arranged in the screw seat (1); The nail body (21) penetrates into the screw seat (1) from the end where the through hole (12) of the screw seat (1) is located and cooperates with the C-shaped hemispherical ring (22) located in the through hole (12); An annular inner groove (13) is provided on the inner wall of the end portion of the through hole (12) facing the U-shaped groove (11), and an angled hole (14) is provided at the end away from the U-shaped groove (11); The deflection angle α between the axial direction of the angled hole (14) and the axial direction of the screw seat is 15°; The angled hole (14) is a through hole with a constricted neck; The top of the nail body (21) is provided with a mounting portion (23), the mounting portion (23) is provided with a conical step (24), and the inner annular surface of the C-shaped hemispherical ring (22) is provided with a conical groove (25) that cooperates with the conical step (24); The outer diameter of the upper end of the conical step (24) is smaller than the outer diameter of the lower end thereof; The inner diameter of the bottom of the angled hole (14) is larger than the outer diameter of the mounting portion (23) and smaller than the outer diameter of the ball head formed by the two C-shaped hemispherical rings (22); The upper part of the neck portion of the angled hole is a trumpet-shaped hole with a larger inner diameter at the top and a smaller inner diameter at the bottom, while the lower part of the neck portion of the angled hole is a trumpet-shaped hole with a smaller inner diameter at the top and a larger inner diameter at the bottom. A limiting step (26) is provided on the top outer ring surface of the C-shaped hemispherical ring (22), and the limiting step (26) cooperates with the bottom of the intermediate body (3); A spherical surface is provided at the bottom of the inner ring surface of the intermediate body. The inner diameter of the top end of the spherical surface is smaller than the inner diameter of the bottom end. Two C-shaped hemispherical rings surround the outside of the mounting portion of the nail body. The top of the mounting portion and the top of the C-shaped hemispherical ring extend into the interior of the intermediate body and cooperate with the spherical surface. Riveting holes (15) are provided on both side outer walls of the screw seat (1), and recessed grooves (33) corresponding to the riveting holes (15) are provided on both side outer walls of the intermediate body (3); The top outer ring of the mounting portion is provided with an upper step. The four steps formed by the upper surface of the mounting portion, the upper step, the upper surface of the C-shaped hemispherical ring and the limiting step are located in the same spherical surface of the bottom of the intermediate body. During assembly, the position of the intermediate body is restricted at the same time so that the recessed groove on the side of the intermediate body is in the riveted position.

2. The universal pedicle screw according to claim 1, characterized in that: The intermediate body (3) is an annular structure, and a C-shaped groove (31) is provided on the top thereof.

3. The universal pedicle screw according to claim 1, characterized in that: The inner walls on both sides of the U-shaped groove (11) are concave arc surfaces, and internal threads (16) are provided on the inner walls.

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