Screw assembly and positioning tool thereof

Abstract

The invention provides a screw assembly and a positioning tool thereof. The screw assembly comprises a screw piece, a screw base and a positioning piece. The screw piece comprises a screw body and a screw ball head; the ball head top face of the screw ball head is a plane, and the upper portion of the screw ball head is provided with an orientation face. A seat body deflection groove is formed in the bottom surface of the nail seat; a concave part is arranged at the bottom of the positioning piece and comprises a guide surface, a positioning surface and a concave ball socket; the guide surface is obliquely arranged relative to the axial direction of the positioning piece; two sides of the positioning surface are respectively connected with the guide surface and the concave ball socket; and the positioning piece is inserted into the seat body mounting hole. The screw assembly is simple in structure, the orthopedic effect can be stabilized and fixed, smooth transition of stress between the two ends of an internal fixation system and the adjacent spines can be achieved, and occurrence of near-end bordering kyphosis is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a screw assembly and a positioning tool thereof. Background Art

[0002] like Figure 1 As shown, for spinal deformity, the current common surgical plan is: insert pedicle screws 2 into the deformed vertebra 1, and then connect the adjacent vertebra 1 through a fixation rod 3, so as to establish a strong internal fixation system and complete spinal correction. Many experts believe that the strong internal fixation of the posterior spine increases the stress at both ends of the internal fixation, that is, the stress between the vertebrae at both ends of the internal fixation system and the adjacent segment vertebrae that are not fixed changes sharply, which leads to the accelerated degeneration of the adjacent segment intervertebral disc and causes the formation of proximal junctional kyphosis.

[0003] Since the spinal stress at both ends of the internal fixation system is relatively large, if a pedicle universal screw is used to connect the spine at the end of the internal fixation system with the adjacent segmental spine that has not been internally fixed, the locking force of the pedicle universal screw cannot achieve a stable fixation and correction effect, and the angle of the pedicle universal screw is easily lost, thus losing the correction ability.

[0004] How to design a connection structure that can achieve a smooth transition of stress from both ends of the internal fixation system to adjacent vertebrae and stably fix the orthopedic effect of the internal fixation system is a problem that technicians in this field need to solve. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the technical problem solved by the present invention is to provide a screw assembly and a positioning tool thereof that can achieve a smooth transition of stress from both ends of an internal fixation system to adjacent vertebrae and can stably fix the corrective effect of the internal fixation system.

[0006] To achieve the above-mentioned object and other related objects, the present invention provides a screw assembly, including: a screw member, a nail seat and a positioning member;

[0007] The screw member comprises a screw body and a screw ball head connected to the upper end of the screw body; the screw ball head is a spherical structure, the top surface of the screw ball head is a plane, the upper part of the screw ball head has an orientation surface, and the upper end of the orientation surface is connected to the top surface of the ball head;

[0008] A seat body mounting groove is provided on the top surface of the nail seat, and the seat body mounting groove passes through the radial direction of the nail seat; a seat body mounting hole is also provided on the top surface of the nail seat; a seat body ball socket is provided at the bottom of the nail seat; a seat body bottom hole is provided on the bottom surface of the nail seat, and a seat body deflection groove is provided on the bottom surface of the nail seat; the groove bottom surface of the seat body deflection groove is inclined relative to the axial direction of the nail seat, the seat body deflection groove is connected with the seat body mounting hole, and the seat body deflection groove is connected with the outside of the nail seat;

[0009] The outer side surface of the positioning member is clearance-matched with the mounting hole of the seat body; a recessed portion is provided at the bottom of the positioning member, and the recessed portion includes a guide surface, a positioning surface and a recessed ball socket; the guide surface is inclined relative to the axial direction of the positioning member, and the two sides of the positioning surface are respectively connected to the guide surface and the recessed ball socket;

[0010] The positioning member is inserted into the mounting hole of the seat body, and the recessed portion of the positioning member and the ball socket of the seat body of the nail seat form a ball head receiving portion for the ball head of the screw to be placed; the screw body passes through the bottom hole of the seat body;

[0011] When the screw body of the screw component is placed in the seat deflection groove, the screw body can rotate around the central axis of the nail seat in the seat deflection groove, the guide surface of the positioning member can contact the top surface of the screw ball head, and the positioning surface of the positioning member can contact the orientation surface of the screw ball head.

[0012] Preferably, the vertical plane passing through the central axis of the nail seat and parallel to the through direction of the seat body mounting groove is the middle plane of the seat body; the nail seat is a structure symmetrically arranged with the middle plane of the seat body as the central axis.

[0013] Preferably, an upper positioning groove and a lower positioning groove are provided on the outer side surface of the positioning member, the upper positioning groove is located directly above the lower positioning groove, and a limiting boss is formed between the upper positioning groove and the lower positioning groove; a seat body convex portion is provided in the seat body mounting hole of the nail seat; when the limiting boss of the positioning member moves to the bottom of the seat body convex portion of the nail seat, the seat body convex portion of the nail seat blocks the limiting boss of the positioning member.

[0014] Preferably, a rod installation groove is provided on the top surface of the positioning member, and the rod installation groove includes a first rod groove and a second rod groove arranged sequentially along the radial direction of the positioning member, and the sizes of the vertical cross-sections of the first rod groove and the second rod groove increase sequentially from the inside to the outside.

[0015] As described above, a screw assembly of the present invention has the following beneficial effects:

[0016] When the screw assembly is in use, the screw body of the screw member sequentially passes through the vertebra at the end of the internal fixation system and the vertebra of the vertebra adjacent to the end, then the fixing rod is installed in the nail seat, and then the screw plug is installed in the mounting hole of the seat body, thereby realizing a smooth transition from the internal fixation system to the adjacent segment; because when the screw assembly is not locked, the positioning member can move up and down along the central axis direction of the nail seat, and the positioning member can also rotate around the central axis of the nail seat, and when the screw body of the screw member is placed in the deflection groove of the seat body, the screw body can rotate around the central axis of the nail seat in the deflection groove of the seat body, so the screw member and the nail seat can rotate relatively, so that the screw assembly has flexibility; when the screw assembly is locked, the guide surface of the positioning member first contacts with the top surface of the ball head of the screw ball head, the positioning member moves downward, and the positioning surface of the positioning member contacts with the orientation surface of the screw ball head, thereby ensuring that the screw member can be stably at a specific angle, so that the screw assembly can maintain the stability of the orthopedic effect of the internal fixation system;

[0017] The screw assembly has a simple structure and can not only stabilize the fixation correction effect, but also achieve a smooth transition of stress from both ends of the internal fixation system to adjacent vertebrae, effectively reducing the occurrence of proximal junctional kyphosis.

[0018] The present invention also relates to a positioning tool for a screw assembly, which is used to install the screw assembly; the positioning tool comprises: a screw placement guide plate component, a guide pin and a drill bit;

[0019] The nail placement guide plate component includes a base plate, a guide cylinder, a connecting rod and a handle; the handle, the connecting rod and the base plate are connected in sequence from top to bottom, the upper end of the handle is provided with a vertical positioning through hole, and the vertical positioning through hole penetrates to the lower surface of the base plate; the lower end of the guide cylinder is connected to the upper surface of the base plate, the upper end of the guide cylinder is provided with a guide through hole, and the lower end of the guide through hole penetrates to the lower surface of the base plate;

[0020] The length direction of the handle is perpendicular to the axial direction of the connecting rod, and the vertical plane passing through the central axis of the connecting rod and parallel to the length direction of the handle is the middle plane of the nail placement guide assembly; the angle between the central axis of the guide cylinder and the central axis of the connecting rod is the second guide angle; when the screw body of the screw member is inserted into the seat body deflection groove, and the central axis of the screw member is located in the middle plane of the seat body of the nail seat, the angle value of the angle between the central axis of the nail seat and the central axis of the screw member is equal to the angle value of the second guide angle;

[0021] The transverse plane perpendicular to the central axis of the connecting rod is the reference plane of the nail placement guide assembly, and the angle formed by the projection of the central axis of the guide cylinder and the middle plane of the nail placement guide assembly on the reference plane of the nail placement guide assembly is the first guide angle; when the screw body of the screw member is placed in the seat body deflection groove, the angle range of the screw body rotating around the central axis of the nail seat in the seat body deflection groove is twice the angle value of the first guide angle;

[0022] The guide pin is inserted into the vertical positioning through hole, and the drill bit is inserted into the guide through hole.

[0023] Preferably, positioning feet are provided on the lower surface of the base plate.

[0024] As described above, a positioning tool of the present invention has the following beneficial effects:

[0025] When the positioning tool is in use, the guide pin can be inserted into the vertical positioning through hole on the handle, the nail placement guide plate component is placed on the surface of the spine, and after the handle of the nail placement guide plate component is adjusted to be parallel to the spinous process of the spine, the nail placement guide plate component is fixed; then the guide pin is taken out, and the drill bit is inserted into the guide through hole to drill; the screw component is implanted along the hole drilled by the drill bit; the first guide angle and the second guide angle are set so that after the screw component is installed by the positioning tool, when the nail seat rotates relative to the screw component, the deflection angle of the screw component is in the seat body deflection groove, and the screw component can be stably locked; the positioning tool has a simple structure and is convenient for locating the installation position of the screw component. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The diagram shows the structure of an existing internal fixation system installed on the spine.

[0027] Figure 2 Shown is a schematic three-dimensional structure diagram of the screw assembly of this embodiment.

[0028] Figure 3 The screw body of the screw assembly of this embodiment is shown as a schematic diagram of the structure in which the screw body is placed in the deflection groove of the seat body, the guide surface of the positioning member contacts the top surface of the ball head of the screw, and the positioning surface of the positioning member contacts the orientation surface of the screw ball head.

[0029] Figure 4 It shows a schematic diagram of the structure when the screw body of the screw assembly of this embodiment is not inserted into the deflection groove of the seat body, the guide surface of the positioning member is not in contact with the top surface of the ball head of the screw ball head, and the positioning surface of the positioning member is not in contact with the orientation surface of the screw ball head.

[0030] Figure 5 The figure shows the cross-sectional structure of the screw assembly of this embodiment when the positioning piece is inserted into the screw seat.

[0031] Figure 6 The diagram shows the bottom structure of the screw assembly of this embodiment when the positioning piece is inserted into the screw seat.

[0032] Figure 7 It is a schematic diagram of the cross-sectional three-dimensional structure when the guide surface of the positioning member of the screw assembly of this embodiment contacts the top surface of the ball head of the screw ball head, and the positioning surface of the positioning member contacts the orientation surface of the screw ball head.

[0033] Figure 8 Shown is a schematic diagram of the three-dimensional structure of the screw assembly of this embodiment when it is exploded.

[0034] Fig. 9 Shown is a top three-dimensional structural schematic diagram of a nail seat of the screw assembly of this embodiment.

[0035] Fig.10 Shown is a schematic cross-sectional structure diagram of a screw seat of the screw assembly of this embodiment.

[0036] Fig.11 Shown is a schematic diagram of the bottom three-dimensional structure of the nail seat of the screw assembly of this embodiment.

[0037] Fig.12 Shown is a schematic cross-sectional structure diagram of a positioning member of the screw assembly of this embodiment.

[0038] Fig.13 Shown is a top three-dimensional structural schematic diagram of a positioning member of the screw assembly of this embodiment.

[0039] Fig.14 Shown is a schematic three-dimensional structure diagram of a screw member of the screw assembly of this embodiment.

[0040] Fig.15 It is a schematic diagram showing the structure of the internal fixation system of this embodiment installed on the spine.

[0041] Fig.16 It is a schematic diagram of the three-dimensional structure of the internal fixation system of this embodiment installed on the spine.

[0042] Fig.17 It is a structural schematic diagram showing the angle between the projection of the central axis of the screw member on the base body reference plane and the central axis of the nail seat when the screw body of the screw assembly of this embodiment moves to any extreme position.

[0043] Fig.18 Shown is a structural schematic diagram of the angle between the center axis of the nail seat and the center axis of the screw member when the screw body of the screw member of the screw assembly of this embodiment is placed in the seat deflection groove and the center axis of the screw member is located in the middle plane of the seat of the nail seat.

[0044] Fig.19Shown is a schematic diagram of the three-dimensional structure of the positioning tool of this embodiment.

[0045] Fig. 20 Display as Fig.19 Schematic diagram of the enlarged structure at B.

[0046] Fig.21 Shown is a schematic diagram of the three-dimensional structure of the positioning tool of this embodiment when it is exploded.

[0047] Fig. 22 Shown is a schematic structural diagram of the first guide angle of this embodiment.

[0048] Fig.23 Shown is a schematic structural diagram of the second guide angle of this embodiment.

[0049] Fig.24 It is a schematic diagram of the three-dimensional structure of the guide needle installed on the spine of this embodiment when it passes through the vertical positioning through hole on the handle.

[0050] Fig.25 It is a schematic diagram of the three-dimensional structure of the nail placement guide plate component of the positioning tool of this embodiment placed on the spine.

[0051] Fig.26 Shown is a schematic diagram of the three-dimensional structure of the nail placing guide component of the positioning tool of this embodiment after the direction is adjusted.

[0052] Fig. 27 The diagram shows a three-dimensional structure of the drill bit of the positioning tool of this embodiment drilling a hole in the spine.

[0053] Fig.28 The diagram shows a three-dimensional structure of the drill bit of the positioning tool of this embodiment adjusting the drilling depth on the spine.

[0054] Fig.29 It is a three-dimensional structural schematic diagram showing the screw member of this embodiment installed on the spine.

[0055] Description of Figure Numbers

[0056] 1. Spine

[0057] 2 Pedicle screws

[0058] 3 Fixing rod

[0059] 100 Screws

[0060] 110 Screw body

[0061] 120 Screw ball head

[0062] 121 Ball head top surface

[0063] 122 Orientation Surface

[0064] 130 Nail Neck

[0065] 200 Nail holder

[0066] 210 seat mounting slot

[0067] 220 Seat mounting hole

[0068] 221 Threaded part

[0069] 230 Seat Ball Socket

[0070] 240 base hole

[0071] 250 Seat deflection slot

[0072] 251 Deflection slot upper through hole

[0073] 252 Deflection slot lower through hole

[0074] 253 Groove bottom

[0075] 260 Base body convex part

[0076] 300 Positioning parts

[0077] 310 Depression

[0078] 311 Guide surface

[0079] 312 Positioning surface

[0080] 313 Concave ball socket

[0081] 321 Upper positioning slot

[0082] 322 Lower positioning slot

[0083] 323 Limiting boss

[0084] 330 Rod mounting slot

[0085] 331 First Rod Slot

[0086] 332 Second rod slot

[0087] 400 Nail guide parts

[0088] 410 Base Plate

[0089] 411 Positioning feet

[0090] 420 Guide Cylinder

[0091] 421 Guide hole

[0092] 430 Connecting rod

[0093] 440 handle

[0094] 441 vertical positioning through hole

[0095] 500 Guide Needle

[0096] 600 Drill Bit

[0097] 700 Pedicle Screw

[0098] 800 Fixing rod

[0099] 900 Screw plug

[0100] 10. Spine

[0101] S1 Seat midplane

[0102] S2 seat body reference plane

[0103] S3 Guide plate middle plane

[0104] S4 Guide plate reference plane

[0105] L1 Centerline of the nail base

[0106] L2 Centerline of connecting rod

[0107] L3 Centerline of screw

[0108] L4 Centerline of guide tube DETAILED DESCRIPTION

[0109] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0110] Please refer to the attached drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the attached drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0111] like Figures 2 to 18As shown, the screw assembly of this embodiment includes: a screw member 100, a screw seat 200 and a positioning member 300;

[0112] The screw component 100 includes a screw body 110 and a screw ball head 120 connected to the upper end of the screw body 110; the screw ball head 120 is a spherical structure, the ball head top surface 121 of the screw ball head 120 is a plane, the ball head top surface 121 is perpendicular to the axial direction of the screw component 100, and the upper part of the screw ball head 120 has an orientation surface 122, and the upper end of the orientation surface 122 is connected to the ball head top surface 121;

[0113] A seat body mounting groove 210 is provided on the top surface of the nail seat 200, and the seat body mounting groove 210 penetrates along the radial direction of the nail seat 200; a seat body mounting hole 220 is also provided on the top surface of the nail seat 200; a seat body ball socket 230 is provided at the bottom of the nail seat 200; a seat body bottom hole 240 is provided on the bottom surface of the nail seat 200, and a seat body deflection groove 250 is provided on the bottom surface of the nail seat 200; the groove bottom surface 253 of the seat body deflection groove 250 is inclined relative to the axial direction of the nail seat 200, the seat body deflection groove 250 is connected with the seat body mounting hole 220, and the seat body deflection groove 250 is connected with the outside of the nail seat 200;

[0114] The outer side surface of the positioning member 300 is clearance-matched with the seat body mounting hole 220; a recessed portion 310 is provided at the bottom of the positioning member 300, and the recessed portion 310 includes a guide surface 311, a positioning surface 312 and a recessed ball socket 313; the guide surface 311 is inclined relative to the axial direction of the positioning member 300, and the two sides of the positioning surface 312 are respectively connected to the guide surface 311 and the recessed ball socket 313;

[0115] The positioning member 300 is inserted into the seat body mounting hole 220. The recessed portion 310 of the positioning member 300 and the seat body ball socket 230 of the nail seat 200 form a ball head receiving portion for the screw ball head 120 to be placed. The screw body 110 passes through the seat body bottom hole 240.

[0116] When the screw body 110 of the screw component 100 is placed in the seat deflection groove 250, the screw body 110 can rotate around the central axis L1 of the nail seat 200 in the seat deflection groove 250, the guide surface 311 of the positioning member 300 can contact the ball head top surface 121 of the screw ball head 120, and the positioning surface 312 of the positioning member 300 can contact the orientation surface 122 of the screw ball head 120.

[0117] When the screw assembly is used, the screw body 110 of the screw member 100 sequentially passes through the vertebra 10 at the end where the internal fixation system is set and the vertebra 10 at the adjacent segment to the vertebra 10 at the end, then the fixing rod 800 is installed in the screw seat 200, and then the screw plug 900 is installed in the seat body installation hole 220. After the screw plug 900 is locked, the screw assembly is in a locked state, thereby achieving a smooth transition from the internal fixation system to the adjacent segment.

[0118] When the screw assembly is not locked, the positioning member 300 can move up and down along the central axis L1 of the nail seat 200, and the positioning member 300 can also rotate around the central axis L1 of the nail seat 200. When the screw body 110 of the screw member 100 is placed in the seat body deflection groove 250, the screw body 110 can rotate around the central axis L1 of the nail seat 200 in the seat body deflection groove 250, so the screw member 100 and the nail seat 200 can rotate relative to each other, so that the screw assembly has flexibility;

[0119] When the screw assembly is locked, the guide surface 311 of the positioning member 300 is arranged opposite to the seat body deflection groove 250, that is, the guide surface 311 of the positioning member 300 and the seat body deflection groove 250 are respectively located on both sides of the central axis L1 of the nail seat 200, and the guide surface 311 of the positioning member 300 first contacts with the ball head top surface 121 of the screw ball head 120. Since the guide surface 311 of the positioning member 300 is inclined relative to the axial direction of the positioning member 300, when the positioning member 300 moves downward, the ball head top surface 121 guides the positioning member 300; the positioning surface 312 of the positioning member 300 contacts with the orientation surface 122 of the screw ball head 120, the screw ball head 120 is received in the ball head receiving portion, and the seat body ball socket 230 and the recessed ball socket 313 are both in contact with the screw ball head 120, thereby ensuring that the screw member 100 can be stably at a specific angle, and the screw assembly can maintain the stability of the orthopedic effect of the internal fixation system;

[0120] Since the pedicle screws used in the internal fixation system in the prior art are mainly installed in the pedicles, the pedicles are mainly composed of cortical bone, and the connecting part between the screw member 100 and the adjacent vertebra 10 in this embodiment is mainly cancellous bone, the connection strength between the screw member 100 and the adjacent vertebra 10 in this embodiment is relatively weak, and a smooth transition of stress from both ends of the internal fixation system to the adjacent vertebra 10 can be achieved, which can effectively reduce the occurrence of proximal junctional kyphosis.

[0121] In order to make the structure of the nail seat 200 more compact, the seat body deflection groove 250 is provided with an upper deflection groove through-hole 251 and a lower deflection groove through-hole 252. The upper deflection groove through-hole 251 connects the seat body deflection groove 250 with the seat body mounting hole 220, and the lower deflection groove through-hole 252 connects the seat body deflection groove 250 with the outside of the nail seat 200.

[0122] The screw assembly has a simple structure, which can not only stabilize the fixation correction effect, but also realize the smooth transition of stress from both ends of the internal fixation system to the adjacent vertebrae 10, effectively reducing the stress at both ends of the spinal internal fixation system and effectively reducing the occurrence of proximal junctional kyphosis.

[0123] The seat body ball socket 230 is for the screw ball head 120 to be placed in, and the structure of the seat body ball socket 230 matches the structure of the screw ball head 120; the seat body mounting groove 210 is a U-shaped groove for installing the fixing rod 800; a threaded portion 221 is provided in the seat body mounting hole 220; the setting of the seat body deflection groove 250 enables the screw component 100 to deflect at a larger angle in the seat body deflection groove 250.

[0124] The vertical plane passing through the center axis L1 of the nail seat 200 and parallel to the through direction of the seat body installation groove 210 is the seat body middle plane S1; the nail seat 200 is a structure symmetrically arranged with the seat body middle plane S1 as the center axis plane. This structure facilitates the processing of the nail seat 200 and makes the structure of the screw assembly more compact.

[0125] The transverse plane perpendicular to the central axis L1 of the nail seat 200 is the seat body reference plane S2; since the nail seat 200 is a structure symmetrically arranged with the middle plane S1 of the seat body as the central axis plane, the seat body deflection groove 250 in the nail seat 200 is a structure symmetrically arranged with the middle plane S1 of the seat body as the central axis plane, and when the screw body 110 rotates around the central axis L1 of the nail seat 200 in the seat body deflection groove 250, the screw body 110 can deflect to two symmetrical extreme positions; when the screw body 110 moves to any extreme position, the angle formed by the projection of the middle plane S1 of the seat body and the central axis L3 of the screw member 100 on the seat body reference plane S2 is angle a. When the screw body 110 of the screw member 100 is placed in the seat body deflection groove 250, the angle range value of the screw body 110 rotating around the central axis L1 of the nail seat 200 in the seat body deflection groove 250 is the value of two angles a. This structure enables two screw members 100 to be symmetrically implanted on the left and right sides of the spinous process of the spine when two screw members 100 are used.

[0126] When the screw body 110 of the screw component 100 is inserted into the seat deflection groove 250 and the central axis L3 of the screw component 100 is in the middle plane S1 of the seat body of the nail seat 200, the angle between the central axis L1 of the nail seat 200 and the central axis L3 of the screw component 100 is angle b. Even if the screw body 110 is in the seat deflection groove 250 and rotates around the central axis L1 of the nail seat 200, the angle of angle b remains unchanged. That is to say, when the screw assembly is locked, the angle of angle b is the angle at which the screw component 100 is stably fixed when the screw body 110 of the screw component 100 is inserted into the seat deflection groove 250.

[0127] The orientation surface 122 is a conical side surface, and the size of the cross section of the conical side surface increases from top to bottom. The structure of the orientation surface 122 can not only enable the screw ball head 120 to stably rotate in the screw seat 200 when the screw member 100 rotates around the central axis L1 of the screw seat 200 in the seat body deflection groove 250; but also enable the positioning surface 312 of the positioning member 300 to stably contact the orientation surface 122 of the screw ball head 120 after the screw assembly is locked. The positioning surface 312 of the positioning member 300 cooperates with the orientation surface 122 of the screw ball head 120, and the positioning member 300 is used to stably press the screw ball head 120.

[0128] In this embodiment, the positioning surface 312 of the positioning member 300 is a conical inner side surface having the same structure as the orientation surface 122 of the screw ball head 120, which enables the positioning surface 312 to fit with the orientation surface 122 of the screw ball head 120. The concave ball socket 313 cooperates with the screw ball head 120. The positioning member 300 is an annular structure.

[0129] An upper positioning groove 321 and a lower positioning groove 322 are provided on the outer side of the positioning member 300, the upper positioning groove 321 is located directly above the lower positioning groove 322, and a limiting boss 323 is formed between the upper positioning groove 321 and the lower positioning groove 322; a seat body convex portion 260 is provided in the seat body mounting hole 220 of the nail seat 200; when the limiting boss 323 of the positioning member 300 moves below the seat body convex portion 260 of the nail seat 200, the seat body convex portion 260 of the nail seat 200 blocks the limiting boss 323 of the positioning member 300. The setting of the limiting boss 323 is used to limit the positioning member 300 from being moved out of the nail seat 200. In this embodiment, there are two upper positioning grooves 321 and two lower positioning grooves 322. The two upper positioning grooves 321 are arranged opposite to each other, and the two lower positioning grooves 322 are arranged opposite to each other. Then, the two limiting bosses 323 are arranged opposite to each other, and the two seat body protrusions 260 of the nail seat 200 are also arranged opposite to each other.

[0130] A rod body installation groove 330 is provided on the top surface of the positioning member 300. The rod body installation groove 330 includes a first rod groove 331 and a second rod groove 332 which are sequentially arranged along the radial direction of the positioning member 300. The vertical cross-section of the first rod groove 331 and the vertical cross-section of the second rod groove 332 are both increased from the inside to the outside. The structure of the first rod groove 331 and the second rod groove 332 enables the fixing rod 800 placed in the rod body installation groove 330 to swing. When the nail seat 200 and the screw member 100 are relatively deflected, the positioning member 300 can achieve good contact with the fixing rod 800.

[0131] The screw body 110 and the screw ball head 120 are connected via a screw neck 130 . The screw body 110 is provided with an external thread. The diameter of the screw neck 130 is smaller than the diameter of the bottom hole 240 of the seat body, so that the screw body 110 can deflect in the bottom hole 240 of the seat body.

[0132] The internal fixation system of this embodiment includes multiple pedicle screws 700, two fixing rods 800, multiple screw plugs 900 and four screw assemblies; pedicle screws 700 are respectively installed on the left and right sides of each vertebra 10, two screw assemblies are respectively installed on the proximal vertebra 10, and each screw member 100 is connected to the vertebra 10 adjacent to the end vertebra 10; one of the fixing rods 800 is installed on all the pedicle screws 700 and screw assemblies on the left side of the vertebra 10, and the other fixing rod 800 is respectively installed on all the pedicle screws 700 and screw assemblies on the right side of the vertebra 10; a screw plug 900 is installed in each pedicle screw 700 and screw assembly, and the screw plug 900 presses the fixing rod 800 to complete the locking of the screw assembly and the pedicle screw 700.

[0133] like Figures 19 to 29 As shown, the positioning tool of this embodiment is used to install the screw assembly; the positioning tool includes: a screw guide plate component 400, a guide pin 500 and a drill bit 600;

[0134] The nail placement guide plate component 400 includes a bottom plate 410, a guide cylinder 420, a connecting rod 430 and a handle 440; the handle 440, the connecting rod 430 and the bottom plate 410 are sequentially connected from top to bottom, the upper end of the handle 440 is provided with a vertical positioning through hole 441, and the vertical positioning through hole 441 penetrates to the lower surface of the bottom plate 410; the lower end of the guide cylinder 420 is connected to the upper surface of the bottom plate 410, the upper end of the guide cylinder 420 is provided with a guide through hole 421, and the lower end of the guide through hole 421 penetrates to the lower surface of the bottom plate 410;

[0135] The length direction of the handle 440 is perpendicular to the axial direction of the connecting rod 430, and the vertical plane passing through the central axis L2 of the connecting rod 430 and parallel to the length direction of the handle 440 is the middle plane S3 of the nail guide assembly; the angle between the central axis L4 of the guide cylinder 420 and the central axis L2 of the connecting rod 430 is the second guide angle; when the screw body 110 of the screw member 100 is placed in the seat body deflection groove 250, and the central axis L3 of the screw member 100 is in the middle plane S1 of the seat body of the nail seat 200, the angle value of the angle between the central axis L1 of the nail seat 200 and the central axis L3 of the screw member 100 is equal to the angle value of the second guide angle; the length direction of the handle 440 is Fig.19 A direction in the middle;

[0136] The transverse plane perpendicular to the central axis L2 of the connecting rod 430 is the reference plane S4 of the nail placement guide assembly, and the angle formed by the projection of the central axis L4 of the guide cylinder 420 and the middle plane S3 of the nail placement guide assembly on the reference plane S4 of the nail placement guide assembly is the first guide angle; when the screw body 110 of the screw member 100 is placed in the seat body deflection groove 250, the angle range value of the screw body 110 rotating around the central axis L1 of the nail seat 200 in the seat body deflection groove 250 is twice the angle value of the first guide angle;

[0137] The vertical positioning through hole 441 is for the guide pin 500 to be inserted, and the guide through hole 421 is for the drill bit 600 to be inserted.

[0138] When the positioning tool is in use, the guide needle 500 can be inserted into the vertical positioning through hole 441 on the handle 440, and the nail placement guide plate component 400 is placed on the surface of the spine 10. After adjusting the handle 440 of the nail placement guide plate component 400 to be parallel to the spinous process of the spine 10, the nail placement guide plate component 400 is fixed; then the guide needle 500 is taken out, and the drill bit 600 is inserted into the guide through hole 421 to drill; the screw component 100 is implanted along the hole drilled by the drill bit 600.

[0139] The first guide angle is angle c, the second guide angle is angle d, the angle value of angle c is equal to the angle value of angle a, and the angle value of angle d is equal to the angle value of angle b. This is so that after the screw component 100 is installed by the positioning tool, when the nail seat 200 rotates relative to the screw component 100, the deflection angle of the screw component 100 is in the seat deflection groove 250, and the screw component 100 can be stably locked; the positioning tool has a simple structure and is convenient for positioning the installation position of the screw component 100.

[0140] A positioning foot 411 is provided on the lower surface of the base plate 410. The positioning foot 411 is provided for positioning on the surface of the vertebra. The positioning foot 411 is a structure with a pointed head at the lower end so that the base plate 410 can be stably fixed on the vertebra.

[0141] The positioning and implantation process of the screw body 110 of the screw member 100 includes the following steps:

[0142] 1) The guide needle 500 passes through the vertical positioning through hole 441 on the handle 440 and is positioned on the surface of the spine 10 by the operator based on experience;

[0143] 2) placing the nail placement guide member 400 on the surface of the spine 10;

[0144] 3) adjusting the handle 440 of the nail placement guide plate component 400 so that the nail placement guide plate component 400 is parallel to the spinous process of the vertebra 10, and fixing the nail placement guide plate component 400;

[0145] 4) Take out the guide pin 500, insert the drill bit 600 into the guide hole, and drill;

[0146] 5) Determine the depth of the drill bit 600 entering the adjacent vertebra 10 according to the size and relative position of the vertebra 10;

[0147] 6) The screw body 110 is implanted along the drilled hole, and the subsequent operations are exactly the same as those of the existing internal fixation system.

[0148] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A screw assembly, characterized in that: include: A screw member (100), a screw seat (200) and a positioning member (300); The screw component (100) comprises a screw body (110) and a screw ball head (120) connected to the upper end of the screw body (110); the screw ball head (120) is a spherical structure, the ball head top surface (121) of the screw ball head (120) is a plane, the upper part of the screw ball head (120) has an orientation surface (122), and the upper end of the orientation surface (122) is connected to the ball head top surface (121); The top surface of the nail seat (200) is provided with a seat body mounting groove (210), and the seat body mounting groove (210) is penetrated along the radial direction of the nail seat (200); the top surface of the nail seat (200) is also provided with a seat body mounting hole (220); the bottom of the nail seat (200) is provided with a seat body ball socket (230); the bottom surface of the nail seat (200) is provided with a seat body bottom hole (240), and the bottom surface of the nail seat (200) is provided with a seat body deflection groove (250); the groove bottom surface (253) of the seat body deflection groove (250) is inclined relative to the axial direction of the nail seat (200), the seat body deflection groove (250) is connected with the seat body mounting hole (220), and the seat body deflection groove (250) is connected with the outside of the nail seat (200); The outer side surface of the positioning member (300) and the seat body mounting hole (220) are clearance-fitted; a recessed portion (310) is provided at the bottom of the positioning member (300), and the recessed portion (310) comprises a guide surface (311), a positioning surface (312) and a recessed ball socket (313); the guide surface (311) is inclined relative to the axial direction of the positioning member (300), and the two sides of the positioning surface (312) are respectively connected to the guide surface (311) and the recessed ball socket (313); The positioning member (300) is inserted into the seat body mounting hole (220), and the recessed portion (310) of the positioning member (300) and the seat body ball socket (230) of the nail seat (200) form a ball head receiving portion for the screw ball head (120) to be placed therein; The screw body (110) passes through the bottom hole (240) of the seat body; When the screw body (110) of the screw member (100) is placed in the seat body deflection groove (250), the screw body (110) can rotate in the seat body deflection groove (250) around the central axis of the nail seat (200), the guide surface (311) of the positioning member (300) can contact the ball head top surface (121) of the screw ball head (120), and the positioning surface (312) of the positioning member (300) can contact the orientation surface (122) of the screw ball head (120).

2. The screw assembly according to claim 1, characterized in that: The vertical plane passing through the central axis of the nail seat (200) and parallel to the through direction of the seat body mounting groove (210) is the seat body middle plane; the nail seat (200) is a structure symmetrically arranged with the seat body middle plane as the central axis.

3. The screw assembly according to claim 1 or 2, characterized in that: An upper positioning groove (321) and a lower positioning groove (322) are provided on the outer side surface of the positioning member (300); the upper positioning groove (321) is located directly above the lower positioning groove (322); a limiting boss (323) is formed between the upper positioning groove (321) and the lower positioning groove (322); a seat body convex portion (260) is provided in the seat body mounting hole (220) of the nail seat (200); when the limiting boss (323) of the positioning member (300) moves to the bottom of the seat body convex portion (260) of the nail seat (200), the seat body convex portion (260) of the nail seat (200) blocks the limiting boss (323) of the positioning member (300).

4. The screw assembly according to claim 1 or 2, characterized in that: A rod installation groove (330) is provided on the top surface of the positioning member (300), and the rod installation groove (330) comprises a first rod groove (331) and a second rod groove (332) which are sequentially arranged along the radial direction of the positioning member (300), and the sizes of the vertical cross-sections of the first rod groove (331) and the second rod groove (332) increase sequentially from the inside to the outside.

5. A positioning tool for a screw assembly, characterized in that: Used for installing the screw assembly according to any one of claims 2 to 4; The positioning tool comprises: a nail placement guide plate component (400), a guide pin (500) and a drill bit (600); The nail placement guide plate component (400) comprises a base plate (410), a guide cylinder (420), a connecting rod (430) and a handle (440); the handle (440), the connecting rod (430) and the base plate (410) are sequentially connected from top to bottom, the upper end of the handle (440) is provided with a vertical positioning through hole (441), and the vertical positioning through hole (441) penetrates to the lower surface of the base plate (410); the lower end of the guide cylinder (420) is connected to the upper surface of the base plate (410), the upper end of the guide cylinder (420) is provided with a guide through hole (421), and the lower end of the guide through hole (421) penetrates to the lower surface of the base plate (410); The length direction of the handle (440) is perpendicular to the axial direction of the connecting rod (430); the vertical plane passing through the central axis of the connecting rod (430) and parallel to the length direction of the handle (440) is the middle plane of the nail guide plate component; the angle between the central axis of the guide cylinder (420) and the central axis of the connecting rod (430) is the second guide angle; when the screw body (110) of the screw component (100) is inserted into the seat deflection groove (250) and the central axis of the screw component (100) is located in the middle plane of the seat of the nail seat (200), the angle value of the angle between the central axis of the nail seat (200) and the central axis of the screw component (100) is equal to the angle value of the second guide angle; A transverse plane perpendicular to the central axis of the connecting rod (430) is a reference plane of the nail placing guide plate component, and an angle formed by the projection of the central axis of the guide cylinder (420) and the middle plane of the nail placing guide plate component on the reference plane of the nail placing guide plate component is a first guide angle; when the screw body (110) of the screw component (100) is inserted into the seat body deflection groove (250), the angle range value of the screw body (110) rotating around the central axis of the nail seat (200) in the seat body deflection groove (250) is twice the angle value of the first guide angle; The vertical positioning through hole (441) is for the guide pin (500) to be inserted, and the guide through hole (421) is for the drill bit (600) to be inserted.

6. The positioning tool for the screw assembly according to claim 5, characterized in that: Positioning feet (411) are provided on the lower surface of the bottom plate (410).

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