Pedicle screw

Abstract

The pedicle screw comprises a screw rod and a spherical head connected with the rear end of the screw rod, the interior of the screw rod is hollow, and a hole channel coaxial with the screw rod is formed; a first threaded section and a second threaded section are sequentially arranged outside the screw rod in the direction from the rear end to the front end of the screw rod; the thread pitch of the first thread section is smaller than that of the second thread section; and a plurality of side wall concave holes communicated with the pore passages are formed in the side wall of the screw rod between adjacent threads of the second thread section and are used for enabling bone debris to enter the pore passages. According to the spinal column screw, the side wall concave hole is formed, so that when the screw is screwed into a spinal column, bone chippings can be automatically drawn into the hole channel, the bone chippings and bones loaded in the hole channel form protein contact, bone growth is further promoted, and the problem that the screw is loosened for a patient after a spinal column operation is solved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of medical devices, and in particular, to a pedicle screw. Background Art

[0002] Osteoporosis is a disease characterized by decreased bone density and deterioration of bone microstructure, resulting in fragile bones and prone to fractures; it is a common disease in the elderly. Screws used in spinal surgery, also known as spinal screws or pedicle screws, are important internal fixation devices used in spinal stabilization and correction surgery. However, the loosening rate of screws after spinal surgery in osteoporotic patients is as high as 60%, while the loosening rate of screws after spinal surgery in non-osteoporotic patients is approximately 1-10%.

[0003] Currently, some researchers have made improvements to the screw itself, (1) increasing the diameter of the screw, changing the thread spacing, or expanding the screw, but this improvement is limited by the anatomical structure of the vertebral bone; (2) optimizing the screw insertion route to allow the screw to pass through areas with higher bone density as much as possible, but its effectiveness cannot be determined when used in patients with osteoporosis; (3) strengthening the screw track and bone cement perfusion technology, but this can easily cause bone cement embolism - pulmonary embolism after treatment.

[0004] Therefore, the problem of screw loosening after existing spinal surgery still needs further research. Summary of the invention

[0005] The purpose of the present disclosure is to provide a pedicle screw that can effectively solve the problem of screw loosening faced by patients after spinal surgery.

[0006] In order to achieve the above-mentioned object, the present disclosure provides a pedicle screw, comprising a screw rod and a spherical head connected to the rear end of the screw rod, wherein the interior of the screw rod is hollow and forms a channel coaxial with the screw rod; A first thread segment and a second thread segment are sequentially included on the outside of the screw and in a direction from the rear end to the front end of the screw; the thread pitch of the first thread segment is smaller than the thread pitch of the second thread segment; A plurality of side wall concave holes communicating with the channel are arranged on the side wall of the screw rod between adjacent threads of the second thread segment, so as to allow bone debris to enter the channel.

[0007] Optionally, the threads of the first thread segment and the second thread segment independently rotate clockwise in a direction from the front end to the rear end of the screw.

[0008] Optionally, along the direction of thread rotation from the front end to the rear end of the screw and along the second thread segment, each of the side wall concave holes includes a first side wall and a second side wall in sequence; the angle between the second side wall and a perpendicular line from any point on the side away from the screw axis to the screw axis is 5-30°.

[0009] Optionally, the vertical distance from any point on the side of the first side wall away from the screw axis to the screw axis is R 1 , the vertical distance from any point on the side of the second side wall away from the screw axis to the screw axis is R 2 , R 2 With R 1 The difference between them is 0.05-1.0mm.

[0010] Optionally, the number of the plurality of side wall concave holes is 3-8.

[0011] Optionally, along the direction of thread rotation from the front end to the rear end of the screw and along the second thread segment, a first side wall concave hole, a second side wall concave hole, a third side wall concave hole, a fourth side wall concave hole, a fifth side wall concave hole and a sixth side wall concave hole are sequentially arranged on the side wall of the screw between adjacent threads.

[0012] Optionally, the first side wall concave hole and the sixth side wall concave hole are arranged toward the same side; The second side wall concave hole and the fifth side wall concave hole face the same side and face opposite to the first side wall concave hole and the sixth side wall concave hole; The third side wall concave hole is oriented opposite to the fourth side wall concave hole, and is oriented differently from the first side wall concave hole, the second side wall concave hole, the fifth side wall concave hole, and the sixth side wall concave hole.

[0013] Optionally, the length of the second thread segment is 1 / 3-3 / 4 of the length of the screw.

[0014] Optionally, bone morphogenetic protein is added into the pores.

[0015] Through the above technical solution, the present disclosure sets a concave hole on the side wall, so that when the screw is screwed into the spine, bone debris can be automatically rolled into the hole, and contact with the bone morphogenetic protein loaded in the hole. The bone morphogenetic protein can promote bone growth into the screw on the one hand, and improve the vertebral bone density on the other hand, thereby increasing the stability between the screw and the vertebral body; thus effectively solving the problem of screw loosening faced by patients after spinal surgery. Other features and advantages of the present disclosure will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 It is a schematic diagram of the structure of the screw disclosed in the present invention.

[0017] Figure 2 It is a structural schematic diagram of one side of the second threaded section of the screw disclosed in the present invention.

[0018] Figure 3 It is a cross-sectional view of the concave hole on the side wall of the screw disclosed in the present invention.

[0019] Description of Reference Numerals 1 screw; 2 first thread segment; 3 second thread segment; 4 concave hole in the side wall; 5 second side wall; 6 First side wall; 7 Channel. DETAILED DESCRIPTION

[0020] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0021] In the present disclosure, unless otherwise specified, directional words such as "inside" and "outside" refer to the contour of the screw of the present disclosure itself; the terms "first", "second", "third", "fourth", "fifth", "sixth" and the like used in the present disclosure are to distinguish one element from another and have no order or importance.

[0022] In the present disclosure, the “front end of the screw” refers to the tip of the screw; the “rear end of the screw” refers to the end of the screw connected to the spherical head. The “direction of rotation of the threads of the second thread segment” refers to the direction in which the threads of the second thread segment spiral upward along the screw from the front end to the rear end of the screw. In the present disclosure, the threads of the second thread segment rotate clockwise from the front end to the rear end of the screw.

[0023] like Figure 1-3 As shown, the present disclosure provides a pedicle screw, comprising a screw rod 1 and a spherical head connected to the rear end of the screw rod 1, wherein the interior of the screw rod 1 is hollow and forms a channel 7 coaxial with the screw rod 1; A first thread segment 2 and a second thread segment 3 are sequentially included outside the screw 1 and in a direction from the rear end to the front end of the screw 1; the thread pitch of the first thread segment 2 is smaller than the thread pitch of the second thread segment 3; A plurality of side wall concave holes 4 communicating with the channel 7 are arranged on the side wall of the screw rod between adjacent threads of the second thread segment 3 , so as to allow bone debris to enter the channel 7 .

[0024] The present invention provides a concave hole on the side wall so that the screw can automatically roll bone debris into the hole when it is screwed into the spine, so that the bone debris can come into contact with the bone morphogenetic protein loaded in the hole, further promoting bone growth, thereby solving the problem of screw loosening faced by patients after spinal surgery.

[0025] In the present disclosure, the aperture of the channel can be the same from the rear end to the front end of the screw, that is, the channel is cylindrical; the aperture of the channel can be different from the rear end to the front end of the screw, for example, the channel can be conical or inverted truncated cone-shaped. Bone morphogenetic protein can be loaded in the channel, for example, rhBMP-2.

[0026] According to the present disclosure, the threads of the first thread segment 2 and the second thread segment 3 are independently rotated clockwise in the direction from the front end to the rear end of the screw 1 .

[0027] Furthermore, if Figure 3 As shown, along the direction of thread rotation from the front end to the rear end of the screw 1 and along the second thread segment 3, each of the side wall concave holes 4 includes a first side wall 6 and a second side wall 5 in sequence; the angle between the second side wall 5 and a perpendicular line from any point on the side away from the screw axis to the screw axis and the second side wall 5 is 5-30°, preferably 10°.

[0028] In the present disclosure, the second side wall is arranged to automatically scrape bone debris into the hole during the screw is screwed into the bone, which is conducive to contact with the bone morphogenetic protein in the hole, thereby promoting bone growth and effectively solving the problem of screw loosening faced by patients after spinal surgery. The arrangement of the first side wall is not specifically limited.

[0029] Furthermore, if Figure 3 As shown, the vertical distance from any point on the side of the first side wall 6 away from the screw axis to the screw axis is R 1 The vertical distance from any point on the side of the second side wall 5 away from the screw axis to the screw axis is R 2 , R 2 With R 1 The difference between them is 0.05-1.0 mm, preferably 0.1 mm.

[0030] In the present disclosure, R 2 With R 1 The difference between 2 Minus R 1 ", by limiting R 2 With R 1The difference between the two can further ensure that bone debris can be scraped into the hole more easily when the screw is screwed into the bone.

[0031] According to the present disclosure, the number of the plurality of side wall concave holes 4 may be 3 to 8. For example, the number of the plurality of side wall concave holes may be 6.

[0032] Furthermore, when the number of the side wall concave holes is 6, as Figure 2 and Figure 3 As shown, along the front end to the rear end of the screw 1 and along the direction of thread rotation of the second thread segment 3, a first side wall concave hole, a second side wall concave hole, a third side wall concave hole, a fourth side wall concave hole, a fifth side wall concave hole and a sixth side wall concave hole are sequentially arranged on the side wall of the screw between adjacent threads.

[0033] Furthermore, the first side wall concave hole and the sixth side wall concave hole are arranged to face the same side; the second side wall concave hole and the fifth side wall concave hole face the same side, and are opposite to the first side wall concave hole and the sixth side wall concave hole; the third side wall concave hole faces the opposite direction to the fourth side wall concave hole, and is different from the first side wall concave hole, the second side wall concave hole, the fifth side wall concave hole and the sixth side wall concave hole. In the present disclosure, concave holes are arranged in four directions, so that bone can grow into the screw in four directions, the screw stability is provided in four directions, the front end of the screw and the second threaded section are better stabilized, and the phenomenon of the screw "cutting" the vertebral body can be effectively avoided.

[0034] According to the present disclosure, the length of the second threaded segment 3 is 1 / 3-3 / 4 of the length of the screw rod 1; the total length of the screw can be set according to the patient's spinal structure, for example, it can be 35mm, 40mm, 45mm and 50mm.

[0035] According to the present disclosure, the thread pitch of the first thread segment may be 2 mm; and the thread pitch of the second thread segment may be 4 mm.

[0036] In the present disclosure, the material of the screw may be titanium alloy.

[0037] In the present disclosure, bone morphogenetic protein is added to the hole 7. The bone morphogenetic protein in the hole helps promote bone growth into the screw, which can improve the vertebral bone density, thereby increasing the stability between the screw and the vertebral body, thereby effectively solving the problem of screw loosening faced by patients after spinal surgery.

[0038] In a specific embodiment of the present disclosure, Figure 1-3As shown, a pedicle screw is made of titanium alloy, and the total length of the screw is 35mm; it includes a screw and a spherical head connected to the rear end of the screw, the interior of the screw is hollow and forms a channel coaxial with the screw; the screw includes a first thread segment and a second thread segment in sequence on the outside of the screw and in the direction from the rear end to the front end of the screw, and the length of the second thread segment is 12.5mm; the thread pitch (2mm) of the first thread segment is smaller than the thread pitch (4mm) of the second thread segment; a plurality of side wall concave holes connected to the channel are arranged on the side wall of the screw between adjacent threads of the second thread segment, so as to allow bone debris to enter the channel. From the front end to the rear end of the screw and in the direction of the thread rotation of the second thread segment, each side wall concave hole includes a first side wall and a second side wall in sequence; the angle between the perpendicular line from any point on the side of the first side wall away from the screw axis to the screw axis and the first side wall is 10°; the angle between the perpendicular line from any point on the side of the second side wall away from the screw axis to the screw axis and the second side wall is 10°. The vertical distance from any point on the side of the first side wall away from the screw axis to the screw axis is R 1 The vertical distance from any point on the side of the second side wall away from the screw axis to the screw axis is R 2 , R 2 With R 1 The difference between them is 0.1mm. Along the front end to the rear end of the screw and along the direction of thread rotation of the second thread segment, a first side wall concave hole, a second side wall concave hole, a third side wall concave hole, a fourth side wall concave hole, a fifth side wall concave hole and a sixth side wall concave hole are sequentially arranged on the side wall of the screw between adjacent threads. The first side wall concave hole and the sixth side wall concave hole are arranged facing the same side; the second side wall concave hole and the fifth side wall concave hole face the same side and are opposite to the first side wall concave hole and the sixth side wall concave hole; the third side wall concave hole faces opposite to the fourth side wall concave hole and is different from the first side wall concave hole, the second side wall concave hole, the fifth side wall concave hole and the sixth side wall concave hole. Bone morphogenetic protein is added to the channel.

[0039] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0040] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0041] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A pedicle screw, comprising a screw rod (1) and a spherical head connected to the rear end of the screw rod (1), characterized in that: The interior of the screw (1) is hollow and forms a channel (7) coaxial with the screw (1); A first thread segment (2) and a second thread segment (3) are sequentially included on the outside of the screw (1) and in the direction from the rear end to the front end of the screw (1); the thread pitch of the first thread segment (2) is smaller than the thread pitch of the second thread segment (3); A plurality of side wall concave holes (4) communicating with the channel (7) are provided on the side wall of the screw rod between adjacent threads of the second thread section (3) for allowing bone debris to enter the channel (7).

2. The screw according to claim 1, characterized in that The threads of the first thread segment (2) and the second thread segment (3) independently rotate clockwise in the direction from the front end to the rear end of the screw rod (1).

3. The screw according to claim 2, characterized in that: In the direction of rotation from the front end to the rear end of the screw rod (1) and along the thread of the second thread segment (3), each of the side wall concave holes (4) comprises a first side wall (6) and a second side wall (5) in sequence; The angle between a perpendicular line from any point on the side of the second side wall (5) away from the screw axis to the screw axis and the second side wall (5) is 5-30°.

4. The screw according to claim 3, characterized in that The vertical distance from any point on the side of the first side wall (6) away from the screw axis to the screw axis is R1, and the vertical distance from any point on the side of the second side wall (5) away from the screw axis to the screw axis is R2, and the difference between R2 and R1 is 0.05-1.0 mm.

5. The screw according to claim 4, characterized in that The number of the plurality of side wall concave holes (4) is 3 to 8.

6. The screw according to claim 5, characterized in that A first side wall concave hole, a second side wall concave hole, a third side wall concave hole, a fourth side wall concave hole, a fifth side wall concave hole and a sixth side wall concave hole are sequentially arranged on the side wall of the screw between adjacent threads along the direction of thread rotation from the front end to the rear end of the screw (1) and along the second thread segment (3).

7. The screw according to claim 6, characterized in that The first side wall concave hole and the sixth side wall concave hole are arranged toward the same side; The second side wall concave hole and the fifth side wall concave hole face the same side and face opposite to the first side wall concave hole and the sixth side wall concave hole; The third side wall concave hole is oriented opposite to the fourth side wall concave hole, and is oriented differently from the first side wall concave hole, the second side wall concave hole, the fifth side wall concave hole, and the sixth side wall concave hole.

8. The screw according to claim 1, characterized in that The length of the second thread segment (3) is 1 / 3-3 / 4 of the length of the screw rod (1).

9. The screw according to claim 1, characterized in that: Bone morphogenetic protein is added into the pore (7).

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