Vertebral pedicle forcing screw

Abstract

The vertebral pedicle forcing screw comprises an end head part and a screw body which are integrally formed, the end head part and the screw body are provided with shaft cavities which are communicated with each other, and a guide wire can penetrate through the shaft cavities; the screw body comprises a first threaded section, a second threaded section and a conical head which are sequentially arranged in the direction away from the end head, the outer diameter of the first threaded section is larger than that of the second threaded section, and the thread pitch of threads on the first threaded section is smaller than that of threads on the second threaded section. The outer diameter of the conical head is gradually reduced in the direction away from the end head portion, and a spiral blade is arranged on the conical head and spirally extends in the axis direction of the conical head. Due to the fact that the spiral blade is arranged on the conical head, and the outer diameter of the conical head is gradually reduced in the direction away from the end head portion, the conical head can conveniently and smoothly enter the bone, pressurization can be conducted step by step along with gradual screwing-in of the nail body, and the situation of insufficient pressurization force or excessive pressurization is avoided. The stability is high, the holding force is higher, and fracture healing is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of medical auxiliary equipment, in particular to a pedicle compression screw. Background Art

[0002] Hangman fractures, also known as traumatic spondylolisthesis of the axis, are generally considered amenable to conservative treatment for type I Hangman fractures. However, a certain percentage of patients may experience delayed dislocation and even neurological symptoms, leading to the development of a swan neck deformity in the long term. For unstable types II, IIA, and III Hangman fractures, the key to surgical treatment is anatomical reduction of the fracture, maintaining the physiologic curvature and rotational range of motion of the cervical spine, and enabling the patient to resume normal life as soon as possible. The main surgical approaches include anterior, posterior, and combined anterior and posterior approaches. While anterior titanium plate fixation is effective, it is difficult to perform, resulting in not only loss of the C2-3 intervertebral disc but also inability to reposition the separated C2 pedicle, significantly increasing the incidence of malunion. Furthermore, the anterior approach presents complex anatomy, and improper intraoperative manipulation may risk damaging vital structures in the anterior cervical spine, particularly the facial, hypoglossal, and superior laryngeal nerves, as well as the carotid sheath. Axis pedicle lag screw fixation not only achieves immediate anatomical reduction but also preserves normal cervical motion.

[0003] The applicant has discovered at least the following technical issues with existing pedicle lag screws: Existing pedicle lag screws lack stable fixation. They rely solely on pressure to secure the pedicle and lamina behind the fracture, lacking a firm grip. The degree of pressure applied during screw fixation relies heavily on the surgeon's experience, and a single application can result in insufficient or excessive pressure, leading to a relapse of the fracture reduction. Furthermore, existing pedicle lag screws are prone to loosening, resulting in poor fixation. Summary of the Invention

[0004] The present invention aims to provide a pedicle compression screw to solve the technical problem of insufficient or excessive compression of pedicle screws in the prior art. The various technical effects that can be produced by the preferred technical solution among the various technical solutions provided by the present invention are described in detail below.

[0005] To achieve the above objectives, the present invention provides the following technical solutions: The pedicle compression screw provided by the present invention comprises an integrally formed end portion and a screw body, wherein: The end portion and the nail body are provided with a connected axial cavity, and the axial cavity is for a guide wire to pass through; The nail body includes a first thread segment, a second thread segment, and a conical head, which are sequentially arranged in a direction away from the end portion, wherein the outer diameter of the first thread segment is larger than the outer diameter of the second thread segment, and the pitch of the thread on the first thread segment is smaller than the pitch of the thread on the second thread segment; The outer diameter of the conical head gradually decreases in a direction away from the end portion. A spiral blade is provided on the conical head, and the pitch of the spiral blade is smaller than the pitch of the thread on the second thread segment.

[0006] Preferably, the pitch of the spiral blade is smaller than the pitch of the thread on the second thread segment.

[0007] Preferably, an optical axis segment is provided on the nail body, and the optical axis segment is located between the end portion and the first threaded segment. The outer diameter of the optical axis segment is smaller than the first threaded segment and the end portion. An anti-loosening component is sleeved on the optical axis segment, and the anti-loosening component is used to prevent the nail body from loosening.

[0008] Preferably, the anti-loosening assembly includes a first gasket and a second gasket, wherein: A first protruding tooth is provided on the lower surface of the first gasket, and the first protruding tooth is used to contact the bone surface; the inclination direction of the first protruding tooth is opposite to the spiral direction of the first thread segment and the second thread segment; The upper surface of the second gasket is provided with a second protruding tooth, and the second protruding tooth is arranged toward the end portion; the inclination direction of the second protruding tooth is opposite to the inclination direction of the first protruding tooth; The first gasket and the second gasket are in an engaged state and a loose state.

[0009] Preferably, the first protruding teeth are formed in a ring shape around the center of the first gasket, and the second protruding teeth are formed in a ring shape around the center of the second gasket.

[0010] Preferably, the upper surface of the first gasket is provided with a first meshing tooth, and the lower surface of the second gasket is provided with a second meshing tooth. Along the tightening direction of the nail body, the second meshing tooth engages with the first meshing tooth, so that the first gasket and the second gasket are in a meshing state.

[0011] Preferably, the first meshing teeth are formed in a ring shape around the center of the first gasket, and the second meshing teeth are formed in a ring shape around the center of the second gasket.

[0012] Preferably, the diameters of the first gasket and the second gasket are smaller than the outer diameter of the end portion and larger than the outer diameter of the first threaded segment.

[0013] Preferably, the end portion is provided with a hexagonal hole for inserting an auxiliary tool into the hole to tighten the nail body.

[0014] Preferably, the length of the nail body ranges from 20 mm to 36 mm, the length of the first thread segment ranges from 10 mm to 14 mm, and the length of the second thread segment ranges from 5 mm to 8 mm.

[0015] The pedicle compression screw provided by the present invention has the following advantages compared to the prior art: when the screw body is screwed in, the spiral blade provided on the conical head is sharper than the threads of the first and second thread segments, and the outer diameter of the conical head gradually decreases in the direction away from the end head, facilitating smooth entry of the conical head into the bone. As the screw body is gradually screwed in, the second and first thread segments sequentially enter the bone. Since the pitch of the threads on the first thread segment is smaller than the pitch of the threads on the second thread segment, gradual pressure can be applied, avoiding insufficient or excessive pressure. The screw has strong stability and stronger holding force, which is conducive to fracture healing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a schematic diagram of the overall structure of the pedicle compression screw; Figure 2 1. It is a schematic diagram of the structure of the pedicle compression screw and the anti-loosening component; Figure 3 yes Figure 2 A partial enlarged view of point A in the middle; Figure 4 yes Figure 2 A partial enlarged view of point B in the middle.

[0018] In the figure, 1 is the nail body; 11 is the first threaded section; 12 is the second threaded section; 13 is the conical head; 14 is the optical axis section; 2 is the end section; 3 is the spiral blade; 4 is the anti-loosening component; 41 is the first gasket; 411 is the first convex tooth; 412 is the first meshing tooth; 42 is the second gasket; 421 is the second convex tooth; 422 is the second meshing tooth; 5 is the hexagonal hole; 6 is the shaft cavity. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0020] In the description of the present invention, it should be understood that the terms "center," "length," "width," "height," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," and "side" and the like, indicating positions or location relationships, are based on the positions or location relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0021] The embodiment of the present invention provides a pedicle compression screw that can gradually apply pressure to avoid insufficient or excessive pressure; it has strong stability and stronger holding force, which is conducive to fracture healing.

[0022] The following combination Figure 1-Figure 4 The technical solution provided by the present invention is described in more detail.

[0023] See also Figure 1-Figure 4 As shown, the pedicle compression screw provided by the present invention includes an integrally formed end portion 2 and a nail body 1, wherein: the end portion 2 and the nail body 1 are provided with a connected axial cavity, the axial cavity for the guide wire to pass through; the nail body 1 includes a first thread segment 11, a second thread segment 12 and a conical head 13 arranged in sequence along the direction away from the end portion 2, the outer diameter of the first thread segment 11 is greater than the outer diameter of the second thread segment 12, and the pitch of the thread on the first thread segment 11 is smaller than the pitch of the thread on the second thread segment 12; the outer diameter of the conical head 13 gradually decreases in the direction away from the end portion 2, and a spiral blade 3 is provided on the conical head 13, which spirally extends around the axial direction of the conical head 13.

[0024] See also Figure 1 As shown, the pedicle compression screw of this embodiment has an end portion 2, a first threaded segment 11, a second threaded segment 12 and a conical head 13 formed in one piece. The outer diameter of the end portion 2 is larger than the outer diameter of the screw body 1. When the tail cap is screwed onto the broken bone, the pedicle tension fixator is prevented from entering the bone and the problem of excessive pressure is avoided.

[0025] See also Figure 2 and Figure 4As shown, in this embodiment, the pitch of the spiral blade 3 is smaller than the pitch of the thread on the second thread segment 12. A higher pressure is applied to the bone surface, which facilitates the smooth screwing of the cone head 13 into the bone.

[0026] As an alternative embodiment, see Figure 2 As shown, an optical axis segment 14 is provided on the nail body 1, and the optical axis segment 14 is located between the end portion 2 and the first threaded segment 11. The outer diameter of the optical axis segment 14 is smaller than the first threaded segment 11 and the end portion 2. An anti-loosening component 4 is sleeved on the optical axis segment 14, and the anti-loosening component 4 is used to prevent the nail body 1 from loosening.

[0027] The anti-loosening component 4 of this embodiment, the optical axis section 14 located on the nail body 1, can cooperate with the bone surface to prevent the nail body 1 from loosening, improve stability, have a stronger holding force, and be beneficial to fracture healing.

[0028] For details, see Figure 2 and Figure 3 As shown, the anti-loosening assembly 4 of this embodiment includes a first gasket 41 and a second gasket 42. The first gasket 41 has a first protruding tooth 411 disposed on its lower surface for contacting the bone surface. The second gasket 42 has a second protruding tooth 421 disposed on its upper surface, facing the end portion 2. The first gasket 41 and the second gasket 42 can be in an engaged state and a disengaged state. The first protruding tooth 411 is inclined in a direction opposite to the spiral direction of the first and second thread segments 11 and 12, while the second protruding tooth 421 is inclined in a direction opposite to the first protruding tooth 411.

[0029] Because the inclination direction of the first protruding teeth 411 is opposite to the spiral direction of the first thread segment 11 and the second thread segment 12, when the nail body 1 tends to loosen, the first protruding teeth 411 and the bone surface increase friction through the teeth, thereby preventing the nail body 1 from loosening. The second protruding teeth 421 can further form an occlusal relationship with the tail cap mounted on the end portion 2, and the corresponding teeth between the second protruding teeth 421 and the tail cap increase friction, thereby preventing the nail body 1 from loosening.

[0030] As an alternative embodiment, see Figure 2 and Figure 3 As shown, the first protruding teeth 411 are formed in a ring shape around the center of the first gasket 41, and the second protruding teeth 421 are formed in a ring shape around the center of the second gasket 42. The upper surface of the first gasket 41 is provided with first meshing teeth 412, and the lower surface of the second gasket 42 is provided with second meshing teeth 422. In the tightening direction of the nail body 1, the second meshing teeth 422 mesh with the first meshing teeth 412, thereby putting the first gasket 41 and the second gasket 42 into a meshing state. The first meshing teeth 412 are formed in a ring shape around the center of the first gasket 41, and the second meshing teeth 422 are formed in a ring shape around the center of the second gasket 42.

[0031] See also Figure 2 and Figure 3 As shown, when the nail body 1 is screwed into the bone and into place, the first gasket 41 and the second gasket 42 are engaged with the first meshing teeth 412 through the second meshing teeth 422. When the nail body 1 tends to loosen, the friction between the first convex teeth 411 and the bone surface is increased by the teeth; when the end portion 2 is matched with the tail cap or other connecting parts, the second convex teeth 421 can further increase the friction with the tail cap and other connecting parts, thereby preventing the nail body 1 from loosening.

[0032] As an alternative embodiment, see Figure 2 and Figure 3 As shown, the diameters of the first gasket 41 and the second gasket 42 are smaller than the outer diameter of the end portion 2 and larger than the outer diameter of the first threaded section 11. The above structure can prevent the first gasket 41 and the second gasket 42 from detaching from the nail body 1.

[0033] As an optional embodiment, the napkin Figure 1 The end portion 2 is provided with an inner hexagonal hole 5 for inserting an auxiliary tool therein to tighten the nail body 1. The nail body 1 can be screwed with a hexagonal wrench, the center of the inner hexagonal hole 5 coincides with the axis of the nail body 1, and the internal shaft cavity can pass a 1.2 mm guide pin.

[0034] As an optional embodiment, the length of the nail body 1 ranges from 20 mm to 36 mm, the length of the first thread segment 11 ranges from 10 mm to 14 mm, and the length of the second thread segment 12 ranges from 5 mm to 8 mm.

[0035] In this embodiment, the length of the pedicle compression screw ranges from 20 mm to 36 mm, and may be 22 mm, 28 mm, or 32 mm, etc. The pitch of the second thread segment 12 ranges from 1.5 mm to 2.0 mm, and the pitch of the first thread segment 11 ranges from 1 mm to 1.5 mm. The diameter of the second thread segment 12 ranges from 3.5 mm to 4.5 mm, and the diameter of the first thread segment 11 ranges from 4.5 mm to 5.5 mm.

[0036] As shown in the above data, the diameter of the second thread segment 12 can be set to 4 mm, the diameter of the first thread segment 11 can be set to 5 mm, the diameter of the end head 2 can be 6.4 mm, the pitch of the second thread segment 12 is 1.75 mm, and the pitch of the first thread segment 11 is 1.25 mm. In this way, when the first thread segment 11 is also screwed into the broken bone, if it is screwed for another circle, it can produce a 0.5 mm reduction and pressure effect on the fracture end. As the screw is continuously screwed in, the fracture ends are gradually pressurized and brought closer, and the fixed fracture tends to be stable.

[0037] In a specific embodiment of the present application, positioning is performed through a reference frame, three-dimensional scanning is performed to obtain images, and after planning, positioning is performed through the robotic arm of an orthopedic robot, and a guide needle is inserted according to the direction of the guide.

[0038] When the screw is screwed in along the guide pin, the second thread segment 12 advances a greater distance per unit angle of rotation than the first thread segment 11, generating axial tension, which continuously pressurizes the fracture ends until the bone surfaces are aligned. When the pedicle compression screw is screwed in, the conical head 13 and the second thread segment 12 first enter the first fracture fragment, and then enter the second fracture fragment, thus fixing the two fracture fragments together. Continuing to rotate, since the thread diameter of the first thread segment 11 is larger than the thread diameter of the second thread segment 12, the two fracture fragments can be pressurized and fixed, and the locking force is guaranteed. When the end portion 2 is screwed into the broken bone, it prevents the pedicle compression screw from entering the bone, while also avoiding the problem of excessive pressure.

[0039] The pedicle compression screw of this embodiment offers high safety, providing double compression to further reduce the fracture while preventing over-compression of the screw body 1. It also offers high stability and stronger holding force, facilitating fracture healing. Furthermore, robot-assisted navigation allows for more precise, minimally invasive, and safe treatment of Hangman fractures.

[0040] In the description of this specification, specific features, structures or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0041] In the description of this specification, the reference terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0042] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A pedicle compression screw, characterized in that: It includes an integrally formed end portion and a nail body, wherein: The end portion and the nail body are provided with a connected axial cavity, and the axial cavity is for a guide wire to pass through; The nail body includes a first thread segment, a second thread segment, and a conical head, which are sequentially arranged in a direction away from the end portion, wherein the outer diameter of the first thread segment is larger than the outer diameter of the second thread segment, and the pitch of the thread on the first thread segment is smaller than the pitch of the thread on the second thread segment; The outer diameter of the conical head gradually decreases in a direction away from the end portion. The conical head is provided with a spiral blade, and the spiral blade extends spirally around the axis direction of the conical head.

2. The pedicle compression screw according to claim 1, characterized in that: The pitch of the helical blade is smaller than the pitch of the thread on the second thread segment.

3. The pedicle compression screw according to claim 1, characterized in that: An optical axis segment is provided on the nail body, and the optical axis segment is located between the end portion and the first threaded segment. The outer diameter of the optical axis segment is smaller than the first threaded segment and the end portion. An anti-loosening component is sleeved on the optical axis segment, and the anti-loosening component is used to prevent the nail body from loosening.

4. The pedicle compression screw according to claim 3, characterized in that: The anti-loosening assembly includes a first gasket and a second gasket, wherein: A first protruding tooth is provided on the lower surface of the first gasket, and the first protruding tooth is used to contact the bone surface; the inclination direction of the first protruding tooth is opposite to the spiral direction of the first thread segment and the second thread segment; The upper surface of the second gasket is provided with a second protruding tooth, and the second protruding tooth is arranged toward the end portion; the inclination direction of the second protruding tooth is opposite to the inclination direction of the first protruding tooth; The first gasket and the second gasket are in an engaged state and a loose state.

5. The pedicle compression screw according to claim 4, characterized in that: The first protruding teeth are in a ring shape surrounding the center of the first gasket, and the second protruding teeth are in a ring shape surrounding the center of the second gasket.

6. The pedicle compression screw according to claim 4, characterized in that: The upper surface of the first gasket is provided with a first meshing tooth, and the lower surface of the second gasket is provided with a second meshing tooth. Along the tightening direction of the nail body, the second meshing tooth engages with the first meshing tooth, so that the first gasket and the second gasket are in a meshing state.

7. The pedicle compression screw according to claim 6, characterized in that: The first meshing teeth are ring-shaped and surround the center of the first gasket, and the second meshing teeth are ring-shaped and surround the center of the second gasket.

8. The pedicle compression screw according to claim 4, characterized in that: The diameters of the first gasket and the second gasket are smaller than the outer diameter of the end portion and larger than the outer diameter of the first threaded segment.

9. The pedicle compression screw according to claim 1, characterized in that: The end portion is provided with a hexagonal hole for inserting an auxiliary tool into the hole to tighten the nail body.

10. The pedicle compression screw according to claim 1, characterized in that: The length of the nail body ranges from 20 mm to 36 mm, the length of the first thread segment ranges from 10 mm to 14 mm, and the length of the second thread segment ranges from 5 mm to 8 mm.

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