CN117257429A

CN117257429A - pedicle screw

Info

Publication number: CN117257429A
Application number: CN202311556066.4A
Authority: CN
Inventors: 肖云锋; 薛明星; 丁涛; 丁贤昌; 陆庭汉
Original assignee: Suzhou And Science & Technology Development Co ltd
Current assignee: Suzhou And Science & Technology Development Co ltd
Priority date: 2023-11-21
Filing date: 2023-11-21
Publication date: 2023-12-22
Anticipated expiration: 2043-11-21
Also published as: CN117257429B

Abstract

The invention provides a pedicle screw, which comprises an outer sheath and a screw rod used for being inserted into the outer sheath, wherein the outer sheath comprises a rod body provided with a first thread part, a through hole formed in the rod body in the radial direction, and at least one anti-falling rod which is arranged in the rod body and can protrude from the rod body in the radial direction, the screw rod is provided with a second thread part, the outer sheath is provided with a first state in which the anti-falling rod is accommodated in the rod body, and a second state in which the screw rod is inserted into the rod body to eject the anti-falling rod in the radial direction, and when the outer sheath is in the second state, one end of the anti-falling rod accommodated in the rod body is clamped between two adjacent screw teeth of the second thread part in the axial direction. According to the pedicle screw, the anti-falling rod and the screw rod capable of pushing out the anti-falling rod outwards in the radial direction are arranged, so that the pedicle screw has a better fixing effect, and even if a patient has osteoporosis, the pedicle screw can be prevented from loosening or falling off.

Description

Pedicle screw

Technical Field

The invention relates to a pedicle screw.

Background

The pedicle screw for posterior fixation of the vertebral column is mainly used for the single-segment and multi-segment posterior internal fixation of lumbar and thoracic vertebral bodies. The indications include: lumbar disc degeneration diseases, scoliosis, rear intervertebral disc excision reduction, spinal canal stenosis, vertebra forward movement, fracture, lumbar vertebra kyphosis deformity, spine tumor, correction of sagittal balance problems, serious kyphosis of thoracic or thoracic lumbar spine, and the like.

Pedicle screws are commonly used as internal fixtures in spinal surgery, and are mainly used for fixing vertebral bodies. The application method comprises the following steps: steel nails are driven into two sides of the pedicle of vertebral arch and are fixed by connecting rods, so as to achieve the purposes of fracture healing, deformity correction, lumbar decompression and the like.

When the traditional pedicle screw meets an osteoporosis patient, the loosening and falling-off conditions of the postoperative pedicle screw are easy to occur, so that the fixation failure is caused, and finally, the fixation failure is caused: pain and discomfort of the waist: pedicle screws stimulate nerve roots, which causes uncomfortable symptoms such as pain, soreness and distention and the like at the waist.

Foreign body sensation: the loosening of the pedicle screw has obvious foreign body sensation.

Reduction in spinal stability: pedicle screw loosening can lead to abnormal spine stabilization structure, and is a common complication of spine surgery.

Nail breakage: the loosening of the pedicle screw can cause stress concentration of the screw after operation, and the risk of breaking the screw is great.

In view of this, there is a need for improvements over existing pedicle screws to address the above-described problems.

Disclosure of Invention

The invention aims to provide a pedicle screw, which solves the problem that the existing pedicle screw is easy to loose and fall off when encountering osteoporosis patients.

In order to achieve the above purpose, the invention provides a pedicle screw, which comprises an outer sheath and a screw rod used for being inserted into the outer sheath, wherein the outer sheath comprises a rod body provided with a first thread part, a through hole formed in the rod body in the radial direction, and at least one anti-falling rod which is arranged in the rod body and can protrude from the rod body in the radial direction, the screw rod is provided with a second thread part, the outer sheath is provided with a first state in which the anti-falling rod is accommodated in the rod body, and a second state in which the screw rod is inserted into the rod body to eject the anti-falling rod in the radial direction, and when the outer sheath is in the second state, one end of the anti-falling rod accommodated in the rod body is clamped between two adjacent screw teeth of the second thread part in the axial direction.

As a further improvement of the invention, the anti-falling rod comprises a rod-shaped anti-falling part and a limiting part arranged at one end of the anti-falling part, wherein the anti-falling part is used for extending out of the through hole, the size of the limiting part is larger than that of the through hole so as to prevent the anti-falling rod from falling out of the through hole, and the limiting part is accommodated in the rod body when the outer sheath is in the second state.

As a further improvement of the invention, the length of the limiting part along the axial direction of the rod body is smaller than or equal to the pitch of the second thread part.

As a further improvement of the invention, the thickness of the limiting part along the radial direction of the rod body is larger than the distance between the second thread part and the inner wall of the rod body when the outer sheath is in the second state.

As a further improvement of the present invention, the anti-drop rod further includes a connection portion connecting the outer sheath and the anti-drop portion when the outer sheath is in the first state, and breaking to allow the anti-drop portion to protrude from the inside of the through hole when the outer sheath is in the second state.

As a further improvement of the invention, the anti-drop rod and the outer sheath are printed by adopting a 3D printing mode.

As a further improvement of the invention, the outer sheath is provided with bone-like micropores.

As a further improvement of the invention, one end of the screw is provided with a guide part, and the guide part is connected with the second thread part and is eccentrically arranged along the axial direction.

As a further improvement of the invention, the through hole is arranged between two adjacent screw teeth of the first screw thread part, and the screw pitch of the second screw thread part is an integral multiple of the screw pitch of the first screw thread part.

As a further improvement of the present invention, the through holes are arranged on the first screw thread portion in an array in the circumferential direction and the axial direction, and each through hole is provided with one of the anti-drop bars.

As a further improvement of the invention, one end of the rod body is provided with an opening for the screw to enter, and the pedicle screw also comprises a U-shaped seat arranged at one end of the rod body, which is provided with the opening, and a connecting rod connected with the U-shaped seat, wherein the connecting plate is connected with the U-shaped seat to shield the opening of the rod body.

As a further improvement of the present invention, the pedicle screw further comprises a ball-type spacer disposed within the U-shaped seat.

As a further improvement of the invention, one end of the screw is provided with a driving port, and the driving port is one of a straight groove, a cross groove, a triangular groove and a hexagonal groove.

The beneficial effects of the invention are as follows: according to the pedicle screw, the anti-falling rod and the screw rod capable of pushing out the anti-falling rod outwards in the radial direction are arranged, so that the pedicle screw has a better fixing effect, and even if a patient has osteoporosis, the pedicle screw can be prevented from loosening or falling off.

Drawings

FIG. 1 is a schematic perspective view of a pedicle screw of the invention;

FIG. 2 is a schematic side elevational view of the pedicle screw of the invention;

FIG. 3 is a schematic cross-sectional view of the sheath and screw of the pedicle screw of the invention;

FIG. 4 is a schematic view of the exploded construction of the sheath and screw of the pedicle screw of the invention in a second condition;

FIG. 5 is a schematic view of the outer sheath of the pedicle screw of the invention in a first condition;

FIG. 6 is a schematic cross-sectional view of the outer sheath of the pedicle screw of the invention in a first condition;

FIG. 7 is a schematic view of the screw of the pedicle screw of the invention;

fig. 8 is a schematic view of the configuration of the U-shaped seat and ball-type washer of the pedicle screw of the invention.

Detailed Description

The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art. In addition, the technical features of the different embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

As shown in fig. 1 to 8, the pedicle screw 100 of the invention comprises an outer sheath 1, a screw rod 2 for inserting the outer sheath 1, a U-shaped seat 3 connected with one end of the outer sheath 1, a connecting rod for connecting with the U-shaped seat 3, and a ball-shaped spacer 4 arranged in the U-shaped seat 3.

Each sheath 1 is internally provided with a screw rod 2, and each connecting rod can be correspondingly connected with a plurality of U-shaped seats 3 of the sheath 1.

As shown in fig. 3 to 6, the sheath 1 includes a rod body 12 formed with a first thread portion 11, a through hole 13 radially formed in the rod body 12, at least one anti-release rod 14 disposed in the rod body 12 and radially protruded from the rod body 12, and a ball head 15 disposed at one end of the rod body 12.

The end of the rod body 12 provided with the ball head 15 is provided with an opening 121 for the screw rod 2 to enter, the other end is conical, the rod body 12 is hollow and is used for accommodating the screw rod 2 and the anti-drop rod 14, and the rod body 12 can be internally provided with a through hole or a blind hole.

The anti-drop rod 14 includes a rod-shaped anti-drop portion 141, a limiting portion 142 disposed at one end of the anti-drop portion 141, and a connecting portion.

As shown in fig. 3 to 4 and 7, the screw 2 is provided with a second thread portion 21, one end of the screw 2 is provided with a guide portion 22, the other end is provided with a driving port 23, and the second thread portion 21 is axially disposed between the guide portion 22 and the driving port 23.

The driving opening 23 is one of a straight slot, a cross slot, a triangular slot and a hexagonal slot. The drive port 23 is used for a user to rotate the screw 2 to access the sheath 1. In practice, the shape is not limited to these, as long as the driving port 23 is provided to drive the screw 2 to rotate.

The sheath 1 has a first state in which the anti-falling rod 14 is accommodated in the rod body 12, and a second state in which the screw 2 is inserted into the rod body 12 to radially eject the anti-falling rod 14, and when the sheath 1 is in the second state, one end of the anti-falling rod 14 accommodated in the rod body 12 is axially clamped between two adjacent screw teeth of the second screw thread portion 21.

In this embodiment, when the sheath 1 is in the first state, the anti-disengagement lever 14 may be fully or partially housed in the rod 12, and in this embodiment, the anti-disengagement lever 14 is partially housed in the rod 12 and does not protrude beyond the major diameter of the first threaded portion 11.

The connection portion connects the outer sheath 1 and the escape prevention portion 141 when the outer sheath 1 is in the first state, and breaks so that the escape prevention portion 141 protrudes from the inside of the through hole 13 when the outer sheath 1 is in the second state.

The guide portion 22 is connected to the second screw portion 21 and is eccentrically disposed in the axial direction. When the screw rod 2 enters the sheath 1, the guiding portion 22 is firstly abutted against the anti-falling rod 14, then the anti-falling rod 14 is clamped between two adjacent screw teeth of the second threaded portion 21, the screw rod 2 is continuously screwed, and the screw rod 2 is radially abutted against the anti-falling rod 14 and pushed out from the through hole 13. The guide portion 22 is eccentrically disposed, so that the length of the anti-falling rod 14 can be guided and pushed out by the guide portion 22 even if the length exceeds half of the inner diameter of the rod body 12, thereby increasing the length of the anti-falling rod 14 and improving the anti-falling effect.

The anti-falling portion 141 is configured to extend from the through hole 13, the size of the limiting portion 142 is larger than the through hole 13 to prevent the anti-falling rod 14 from falling out of the through hole 13, and the limiting portion 142 is accommodated in the rod body 12 when the outer sheath 1 is in the second state.

The end of the anti-falling portion 141, which is far away from the limiting portion 142, is a tip, so that the bone is inserted into the bone more easily in the radial direction, and the anti-falling portion 141 can play a role in preventing the pedicle screw 100 from loosening and falling off after being inserted into the bone.

The length of the limiting portion 142 along the axial direction of the rod body 12 is smaller than or equal to the pitch of the second threaded portion 21, and the thickness of the limiting portion 142 along the radial direction of the rod body 12 is greater than the distance between the second threaded portion 21 and the inner wall of the rod body 12 when the outer sheath 1 is in the second state. That is, the limiting portion 142 is clamped between two adjacent threads of the second threaded portion 21, and the limiting portion 142 can prevent the release preventing rod 14 from being released from the through hole 13, so that the pedicle screw 100 cannot be prevented from loosening or releasing, and can limit the axial position of the screw 2, so as to prevent the screw 2 from being released from the rod body 12.

In addition, the U-shaped seat 3 is disposed at one end of the rod body 12 provided with an opening 121 and is connected with the ball head 15, and the connecting plate is connected with the U-shaped seat 3 to shield the opening 121 of the rod body 12, so as to achieve the effect of preventing the screw 2 from being separated from the rod body 12.

The ball-type gasket 4 covers the ball head 15.

The through hole 13 is disposed between two adjacent threads of the first threaded portion 11, and the pitch of the second threaded portion 21 is an integer multiple of the pitch of the first threaded portion 11, so that it can be ensured that the through hole 13 is disposed between two adjacent threads of the first threaded portion 11, and the anti-falling rod 14 is disposed between two adjacent threads of the second threaded portion 21.

The through holes 13 are arranged on the first threaded portion 11 in an array manner along the circumferential direction and the axial direction, and each through hole 13 is correspondingly provided with one anti-falling rod 14. In this embodiment, four through holes 13 and anti-falling bars 14 are provided in every other set of threads, and the four through holes 13 and the anti-falling bars 14 on the same circle of threads face four different directions of front, rear, left and right.

The anti-drop rod 14 and the outer sheath 1 are printed by adopting a 3D printing mode. Furthermore, the outer sheath 1 is provided with bone-like micropores, one end connected with the U-shaped seat 3 is solid, the bone-like micropores are not provided to improve the structural strength, and one end, which is far away from the U-shaped seat 3 and needs to be inserted into bones, of the outer sheath is printed with bone-like micropores, so that the outer sheath can be better combined with the bones, and the problems of loosening and falling of the pedicle screw 100 after being placed can be solved.

Through 3D printing, it is easier to form bone-like micropores, and it is easier to form a connecting portion, in this embodiment, the connecting portion connects the rod body 12 with the one end of the anti-drop portion 141 that is far away from the limiting portion 142, and the connecting portion can prevent the anti-drop rod 14 from protruding from the through hole 13 when the screw 2 is not inserted into the connecting rod, so that the sheath 1 is not affected to enter the bone.

If the 3D printing technique is not used, the pedicle screw 100 of the invention may be manufactured in other ways, but the difficulty and cost are increased.

In this embodiment, the U-shaped seat 3 and the ball-shaped pad 4 are made of conventional machining and are made of metal materials.

The pedicle screw 100 of the invention is used as follows:

the vertebral arch to be operated is exposed through the appropriate surgical approach, the specific approach to be stapled is determined, typically by cross-method or herringbone crest method, and then the pedicle screw 100 of the appropriate length is placed in the pedicle.

The pedicle screw 100 is placed in the following manner: the outer sheath 1 is placed into a vertebral body through a pedicle to enter a desired position, the screw rod 2 is inserted into the rod body 12, the screw rod 2 is driven to rotate into the rod body 12 by the driving port 23, the anti-falling rod 14 is propped against the guiding part 22, the anti-falling rod 14 is driven to move outwards in the radial direction, the connecting piece is broken, and the anti-falling part 141 is inserted into the vertebral body in the radial direction; the attachment bar is attached to the U-shaped seat 3 of one or more pedicle screws 100, and a simple correction is finally made to the patient, eventually securing the suture incision.

According to the pedicle screw 100, the anti-falling rod 14 and the screw rod 2 capable of pushing the anti-falling rod 14 out in the radial direction are arranged, so that the pedicle screw 100 has a better fixing effect, and even if a patient has osteoporosis, the pedicle screw 100 can be prevented from loosening or falling off. The prepared sheath 1 and the anti-drop rod 14 in a 3D printing mode are low in molding difficulty, low in cost and good in using effect.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. A pedicle screw, characterized in that: the pedicle screw comprises an outer sheath and a screw rod used for being inserted into the outer sheath, the outer sheath comprises a rod body provided with a first threaded part, a through hole formed in the rod body in the radial direction, and at least one anti-falling rod which is arranged in the rod body and can protrude from the rod body in the radial direction, the screw rod is provided with a second threaded part, the outer sheath is provided with a first state that the anti-falling rod is contained in the rod body, the screw rod is inserted into the rod body to enable the anti-falling rod to be in a second state that the anti-falling rod is ejected out in the radial direction, and when the outer sheath is in the second state, one end of the anti-falling rod contained in the rod body is clamped between two adjacent screw teeth of the second threaded part in the axial direction.

2. A pedicle screw as claimed in claim 1, wherein: the anti-falling rod comprises a rod-shaped anti-falling part and a limiting part arranged at one end of the anti-falling part, the anti-falling part is used for extending out of the through hole, the size of the limiting part is larger than that of the through hole so as to prevent the anti-falling rod from being separated from the through hole, and the limiting part is contained in the rod body when the outer sheath is in a second state.

3. A pedicle screw as claimed in claim 2, wherein: the length of the limiting part along the axial direction of the rod body is smaller than or equal to the pitch of the second thread part.

4. A pedicle screw as claimed in claim 2, wherein: the thickness of the limiting part along the radial direction of the rod body is greater than the distance between the second thread part and the inner wall of the rod body when the outer sheath is in the second state.

5. A pedicle screw as claimed in claim 2, wherein: the anti-drop rod further comprises a connecting part, when the outer sheath is in a first state, the connecting part is connected with the outer sheath and the anti-drop part, and when the outer sheath is in a second state, the connecting part is broken to enable the anti-drop part to protrude from the through hole.

6. A pedicle screw as claimed in any one of claims 1-5, wherein: the anti-drop rod and the outer sheath are printed in a 3D printing mode.

7. A pedicle screw as claimed in claim 6, wherein: the sheath is provided with bone-like micropores.

8. A pedicle screw as claimed in any one of claims 1-5, wherein: one end of the screw rod is provided with a guide part, and the guide part is connected with the second threaded part and is eccentrically arranged along the axial direction.

9. A pedicle screw as claimed in claim 1, wherein: the through hole is arranged between two adjacent screw threads of the first screw thread part, and the screw pitch of the second screw thread part is an integral multiple of the screw pitch of the first screw thread part.

10. A pedicle screw as claimed in claim 9, wherein: the through holes are arranged on the first threaded portion in an array mode along the circumferential direction and the axial direction, and each through hole is correspondingly provided with one anti-falling rod.

11. A pedicle screw as claimed in claim 1, wherein: the pedicle screw comprises a rod body, and is characterized in that an opening for the screw to enter is formed in one end of the rod body, a U-shaped seat is arranged at one end of the rod body, which is provided with the opening, and a connecting rod connected with the U-shaped seat, and the connecting plate is connected with the U-shaped seat to cover the opening of the rod body.

12. A pedicle screw as claimed in claim 11, wherein: the pedicle screw further comprises a spherical gasket arranged in the U-shaped seat.

13. A pedicle screw as claimed in claim 1, wherein: one end of the screw rod is provided with a driving port, and the driving port is one of a straight groove, a cross groove, a triangular groove and a hexagonal groove.