Pedicle screw

Abstract

The invention discloses a pedicle screw capable of realizing double-cortical fixation and directional bone cement reinforcement, belongs to the field of vertebra operation equipment, and aims to solve the problem of how to organically combine the double-cortical fixation of a common screw with a bone cement screw reinforcement technology to improve the stability. The pedicle screw comprises a pedicle screw body, wherein the pedicle screw body comprises a first hollow pipe, a second hollow pipe and a third tail end unit; the first hollow tube, the second hollow tube and the third tail end unit are sequentially connected to form a pedicle screw body; and a second sludge outlet channel is arranged in the circumferential direction of the second hollow pipe and is in a strip shape. By the adoption of the hollow pedicle screw, the binding force between the hollow pedicle screw and the bone can be enhanced, the holding force of the bone on the pedicle screw is effectively improved, stability is improved, the force line is corrected, firm fixation is achieved, and the hollow pedicle screw has important influence on improvement of operation quality. Furthermore, directional distribution of the bone cement can be achieved, and unnecessary dispersion is avoided.

Description

Technical Field

[0001] This application relates to the field of orthopedics, particularly to the field of vertebral surgical equipment, specifically a pedicle screw. More specifically, this application provides a pedicle screw capable of achieving bicortical fixation and directional bone cement reinforcement, which effectively improves the patient's surgical experience and has extremely high practical value. Background Technology

[0002] In recent years, with the aging population, the number of elderly people has been increasing, and consequently, the number of osteoporosis patients has also increased. Therefore, an increasing number of spinal osteoporosis-related diseases require surgical treatment.

[0003] Currently, there are two main surgical treatments for osteoporosis-related diseases: one is bicortical fixation using ordinary screws, and the other is reinforcement using hollow cemented screws. How to organically combine these two existing techniques to simultaneously achieve bicortical fixation and cemented screw reinforcement has become an urgent technical problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to address the problem of how to organically combine the bicortical fixation of ordinary screws with bone cement screw reinforcement technology to improve stability, and to provide a pedicle screw. Using this invention, the bonding force between the hollow pedicle screw and the bone can be enhanced, effectively increasing the bone's holding force on the pedicle screw, increasing stability, correcting the force line, and achieving strong fixation, which has a significant impact on improving surgical quality. Furthermore, this application enables the directional distribution of bone cement, avoiding unnecessary diffusion.

[0005] To achieve the above objectives, this application adopts the following technical solution: A pedicle screw includes a pedicle screw body, wherein the pedicle screw body includes a first hollow tube, a second hollow tube, and a third terminal unit; The first hollow tube, the second hollow tube, and the third end unit are connected in sequence to form a pedicle screw body; Threads are respectively provided on the outer wall of the first hollow tube, the outer wall of the second hollow tube, and the outer wall of the third end unit. The threads on the outer wall of the first hollow tube, the threads on the outer wall of the first hollow tube, and the threads on the outer wall of the third end unit are arranged sequentially and cooperate with each other. One end of the second hollow tube is connected to the first hollow tube, and the other end of the second hollow tube is connected to the third end unit; the second hollow tube is provided with a plurality of second mud discharge channels for bone cement to flow out in the circumferential direction, and the second mud discharge channels are strip-shaped; Along the circumferential direction of the second hollow tube, the second mud discharge channel is distributed in N directions of the second hollow tube, and N is a natural number and N=1~6; The inner wall of the first hollow tube and the inner wall of the second hollow tube together form a fluid channel for injecting bone cement. The fluid channel is connected to the second mud outlet channel and the bone cement injected through the fluid channel can flow out to the outside of the second hollow tube through the fluid channel. The third end unit is a third solid tip; or the third end unit includes a third hollow tip and a third plug that cooperates with the third hollow tip, the third hollow tip is provided with a third hollow channel, the third plug is provided in the third hollow channel and the third plug can block the third hollow channel.

[0006] The threads on the outer wall of the first hollow tube, the threads on the outer wall of the first hollow tube, and the threads on the outer wall of the third end unit are integrally formed.

[0007] The first hollow tube has a first channel mark at the end away from the second hollow tube that cooperates with the second sludge discharge channel, and the direction of the second sludge discharge channel can be identified by the first channel mark.

[0008] The first hollow tube and the second hollow tube are both cylindrical.

[0009] The second mud discharge channel is evenly distributed around the pedicle screw body.

[0010] The length of the second mud discharge channel is 2-40 mm. Preferably, the length of the second mud discharge channel is 5-30 mm.

[0011] The width of the second mud discharge channel is 1~3mm.

[0012] The length of the third end unit is 2~10mm.

[0013] The third end unit is a third solid tip. The first hollow tube, the second hollow tube, and the third end unit are connected in sequence and integrally formed. The fluid channel is not connected to the third end unit and the bone cement injected through the fluid channel cannot flow out through the third end unit. Alternatively, the third end unit may include a third hollow tip and a third plug that cooperates with the third hollow tip. The third hollow tip is provided with a third hollow channel. The third plug is disposed in the third hollow channel and can seal the third hollow channel. The third plug and the third hollow tip are detachably connected. The first hollow tube, the second hollow tube, and the third hollow tip are sequentially connected as a whole and are integrally formed.

[0014] The third hollow channel is connected to the fluid channel; the third plug can be sent into the third hollow channel through the fluid channel and, under the action of external force, the third plug is tightly fitted to the third hollow channel to seal the third hollow channel and prevent the bone cement injected through the fluid channel from flowing out through the third end unit.

[0015] The third end unit is a third solid tip, which is nail-shaped or screw-shaped; Alternatively, the third end unit may include a third hollow tip and a third plug that mates with the third hollow tip, wherein the third hollow tip is shaped like a spike or a screw.

[0016] It also includes several second sealing elements that cooperate with the second sludge discharge channel. The second sealing elements can be installed on the second sludge discharge channel and can block the second sludge discharge channel and prevent the bone cement in the fluid channel from flowing out through the blocked second sludge discharge channel.

[0017] It also includes the pedicle screw tail connected to the pedicle screw body.

[0018] The inner wall of the pedicle screw tail is threaded. Attached Figure Description

[0019] The present invention will be described by way of example and with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the pedicle screw structure in Example 1.

[0020] The markings in the diagram are: 1. First hollow tube, 2. Second hollow tube, 3. Third end unit, 4. Second mud discharge channel, 5. Pedicle nail tail. Detailed Implementation

[0021] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0022] Any feature disclosed in this specification, unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is merely one example of a series of equivalent or similar features.

[0023] Existing technologies already include descriptions of hollow pedicle screws. For example, Chinese patent application CN202120408297.0 discloses a pedicle screw comprising a screw seat, a main screw body, and a connecting screw body. The main screw body has a bone cement injection channel and several bone cement holes. Both ends of each bone cement hole communicate with the bone cement injection channel and the outside of the main screw body. The main screw body also has an injection hole that communicates with the bone cement injection channel.

[0024] Chinese patent application CN201810861293.0 discloses an elliptical hollow pedicle screw with side holes. The hollow pedicle screw has a hollow body and a through end. The side holes are distributed in the distal third of the threaded section of the pedicle screw, along a spiral line at 120° intervals. The central axis of the holes is perpendicular to the longitudinal axis of the screw body, and the spacing is equal. The ratio of the minor to major semi-axis of the elliptical side holes is 0.75-0.85. The major axis of the elliptical holes is parallel to the direction of the thread spiral. The size of the elliptical holes increases along the screw depth. This structure allows the elliptical side holes to be as large as possible while ensuring the screw body strength, and also reduces local fluid resistance loss by utilizing the guiding effect of the elliptical holes. The increasing size of the elliptical side holes ensures uniform distribution of bone cement along the screw body direction.

[0025] However, existing hollow pedicle screws cannot simultaneously achieve bicortical fixation and bone cement screw reinforcement.

[0026] Example 1 This embodiment provides a pedicle screw, which includes a pedicle screw body and a pedicle screw tail connected to the pedicle screw body, wherein the inner wall of the pedicle screw tail is provided with threads. In a specific example, the pedicle screw of this application is made of titanium alloy (Ti6Al4V).

[0027] The pedicle screw body includes a first hollow tube, a second hollow tube, and a third end unit; the first hollow tube and the second hollow tube are both cylindrical; in this embodiment, the third end unit adopts a third solid tip. The first hollow tube, the second hollow tube, and the third end unit are sequentially connected and integrally formed to constitute the pedicle screw body. Threads are respectively provided on the outer wall of the first hollow tube, the outer wall of the second hollow tube, and the outer wall of the third end unit; the threads on the outer wall of the first hollow tube, the outer wall of the third end unit, and the outer wall of the third end unit are integrally formed.

[0028] One end of the second hollow tube is connected to the first hollow tube, and the other end of the second hollow tube is connected to the third end unit. The second hollow tube has several second slurry outlet channels arranged circumferentially for the outflow of bone cement; these channels are strip-shaped. The inner walls of the first and second hollow tubes together form a fluid channel for injecting bone cement. This fluid channel communicates with the second slurry outlet channels but not with the third end unit. With this structure, bone cement injected through the fluid channels can flow outwards through the fluid channels to the outside of the second hollow tube, but cannot flow outwards through the third end unit. Furthermore, the length of the second slurry outlet channel is 2-40 mm (preferably 5-30 mm), the width of the second slurry outlet channel is 1-3 mm, and the length of the third end unit is 2-10 mm.

[0029] Along the circumferential direction of the second hollow tube, the second sludge outlet channels are distributed in N directions within the second hollow tube, where N is 1, 2, 3, 4, 5, or 6. Specifically, the distribution direction of the second sludge outlet channels within the second hollow tube can be selected according to actual needs. Furthermore, a first channel mark is provided at the end of the first hollow tube away from the second hollow tube, which cooperates with the second sludge outlet channels; with this structure, the direction of the second sludge outlet channels can be confirmed by the first channel mark; during surgery, the direction of bone cement outflow can be determined by the first channel mark, thereby improving the safety of the surgery.

[0030] In actual use, the direction and number of the second mud discharge channels can be preset. For example, the direction of the second mud discharge channels on the second hollow tube is 1, 2, 3 or 4. When a single direction corresponds to a single second mud discharge channel, the corresponding number of second mud discharge channels is 1, 2, 3 or 4.

[0031] As an alternative, several second sealing elements are also included to cooperate with the second sludge discharge channel. These second sealing elements can be installed on the second sludge discharge channel and can block it, preventing bone cement in the fluid channel from flowing out through the blocked channel. This structure adopts a universal design. Specifically, for example, if there are four directions of the second sludge discharge channel on the second hollow tube, and each direction corresponds to a single second sludge discharge channel, then there are four such channels. When bone cement needs to be discharged in one or more directions, second sealing elements can be installed on the remaining channels to block them, ensuring that at least one direction of the channel remains open, thus achieving directional flow of bone cement (i.e., allowing bone cement to flow out in one or more directions).

[0032] In this embodiment, the third terminal unit employs a third solid tip. In actual use, the third solid tip, the second hollow tube, and the first hollow tube are sequentially drilled into the bone. In this embodiment, the third solid tip blocks one end of the fluid channel, preventing bone cement from flowing out through the third solid tip and allowing it to flow out only through the second drainage channel laterally to the pedicle screw. With this structure, the third solid tip and the second drainage channel cooperate, allowing bone cement to flow out in a predetermined direction by selecting the second drainage channel. Simultaneously, the structural design of the third terminal unit enables the pedicle screw of this application to achieve bicortical fixation, which is impossible in the prior art. Furthermore, this application achieves the dual effects of bicortical fixation and bone cement reinforcement technology, thereby ensuring sufficient postoperative stability, which is impossible in the prior art.

[0033] The procedure for pedicle screw surgery using this embodiment is as follows.

[0034] 1. At room temperature, place 20g of PMMA bone cement powder and 10mL of solvent into a stainless steel bowl and mix strictly according to the powder-to-liquid ratio of 2:1. After the bone cement becomes a paste, put 10ml of the paste into a syringe to complete the preparation of the bone cement.

[0035] 2. First, use a breaker to open the channel at the needle entry point, and then use a tap to tap out the required nail path; at this time, select the corresponding pedicle screw according to the set out direction, and then insert the pedicle screw into the nail path, and adjust and confirm the opening direction of the second mud discharge channel on the pedicle screw through the first channel mark.

[0036] 3. Prepared bone cement is implanted into the fluid channel of the pedicle screw; during the bone cement infusion process, the bone cement flows out through the fluid channel to the outside of the second hollow tube; after the bone cement hardens, the pedicle screw is reinforced. In one surgery, PMMA was used as the bone cement, and the amount of bone cement injected into the pedicle screw was 1.5mL~2mL of PMMA.

[0037] In this embodiment, the direction and number of the second mud discharge channels can be predetermined; alternatively, a universal structure can be adopted (the so-called universal structure refers to the second hollow tube being provided with multiple second mud discharge channels (for example, the second hollow tube being provided with 4 or 6 second mud discharge channels), and the second mud discharge channels are sealed by the second sealing member so that the direction and number of the second mud discharge channels meet the corresponding requirements) to meet the needs of different situations. In this case, at least one second mud discharge channel must be kept unobstructed.

[0038] Example 2 This embodiment provides a pedicle screw that can be used for percutaneous surgical fixation. It includes a pedicle screw body and a pedicle screw tail connected to the pedicle screw body, and the inner wall of the pedicle screw tail is provided with threads.

[0039] The pedicle screw body includes a first hollow tube, a second hollow tube, and a third end unit; the first and second hollow tubes are both cylindrical. In this embodiment, the third end unit includes a third hollow tip and a third plug that mates with the third hollow tip. A third hollow channel is provided inside the third hollow tip, and the third plug and the third hollow tip are detachably connected; the third plug is located inside the third hollow channel and can seal the third hollow channel. In this embodiment, the first hollow tube, the second hollow tube, and the third hollow tip are sequentially connected and integrally formed to constitute the pedicle screw body. Threads are provided on the outer walls of the first hollow tube, the second hollow tube, and the third hollow tip, respectively, and the threads on the outer walls of the first hollow tube, the second hollow tube, and the third hollow tip are sequentially arranged and mutually mating.

[0040] One end of the second hollow tube is connected to the first hollow tube, and the other end of the second hollow tube is connected to the third end unit. The second hollow tube has several second mud-outflow channels arranged circumferentially for bone cement outflow; these second mud-outflow channels are strip-shaped. The inner walls of the first and second hollow tubes together form a fluid channel for injecting bone cement, and this fluid channel communicates with the second mud-outflow channels. In this embodiment, the third hollow channel at the tip of the third hollow tube communicates with the fluid channel. Using this structure, when the third plug in the third end unit is removed, it can be used as a regular screw for bicortical fixation. The surgical fixation procedure using this pedicle screw is as follows.

[0041] 1. Precisely locate the target vertebra using a C-arm X-ray machine or navigation system.

[0042] 2. Make a small incision of about 2mm in the skin, and insert a puncture guide needle percutaneously into the pedicle and vertebral body to establish an implantation channel.

[0043] 3. Insert pedicle screws along the guide pin.

[0044] 4. After the pedicle screws have stabilized, suture the incision. Postoperative imaging confirms the screw position.

[0045] If osteoporosis is discovered during surgery, or the stability of the pedicle screws is poor, and it is decided to temporarily reinforce with bone cement, the solution proposed in this application can be used to seal the third hollow channel with a third plug, thereby preventing the fluid channel from communicating with the third terminal unit, and preventing the bone cement injected through the fluid channel from flowing out through the third terminal unit. When using the structure with the third plug sealing the third hollow channel, the bone cement injected through the fluid channel can flow out to the outside of the second hollow tube, but cannot flow out through the third terminal unit; that is, the fluid channel is not communicating with the third terminal unit. Furthermore, the length of the second mud outlet channel is 2-40 mm, the width of the second mud outlet channel is 1-3 mm, and the length of the third terminal unit is 2-10 mm.

[0046] When the third plug is used to seal the third hollow channel, the complete procedure for surgical fixation using the pedicle screw is as follows.

[0047] 1. Precisely locate the target vertebra using a C-arm X-ray machine or navigation system.

[0048] 2. Make a small incision of about 2mm in the skin, and insert a puncture guide needle percutaneously into the pedicle and vertebral body to establish an implantation channel.

[0049] 3. Insert the pedicle screw along the guide pin. If, at this point, the surgeon discovers osteoporosis at the surgical site and the pedicle screw's stability is poor, necessitating temporary bone cement reinforcement, a third plug is used to seal the third hollow channel, thus preventing the fluid channel from communicating with the third terminal unit. The specific procedure is as follows: After implantation, withdraw the guide pin, insert the third plug into the third hollow channel, and apply external force to ensure a tight fit between the third plug and the third hollow channel, thereby sealing the third hollow channel.

[0050] 4. At room temperature, place 20g of PMMA bone cement powder and 10mL of solvent into a stainless steel bowl and mix strictly according to the powder-to-liquid ratio of 2:1. After the bone cement becomes a paste, put 10ml of the paste into a syringe to complete the preparation of the bone cement.

[0051] 5. The prepared bone cement is implanted into the fluid channel of the pedicle screw; during the bone cement infusion process, the bone cement flows out to the outside of the second hollow tube through the fluid channel; after the bone cement hardens, the pedicle screw reinforcement is completed.

[0052] 6. After the pedicle screws have stabilized, suture the incision. Postoperative imaging confirms the screw position.

[0053] Along the circumferential direction of the second hollow tube, the second sludge outlet channels are distributed in N directions within the second hollow tube, where N is 1, 2, 3, 4, 5, or 6. Specifically, the distribution direction of the second sludge outlet channels within the second hollow tube can be selected according to actual needs. Furthermore, a first channel mark is provided at the end of the first hollow tube away from the second hollow tube, which cooperates with the second sludge outlet channels; with this structure, the direction of the second sludge outlet channels can be confirmed by the first channel mark; during surgery, the direction of bone cement outflow can be determined by the first channel mark, thereby improving the safety of the surgery.

[0054] In actual use, the direction and number of the second mud discharge channels can be preset. For example, the direction of the second mud discharge channels on the second hollow tube is 1, 2, 3 or 4. When a single direction corresponds to a single second mud discharge channel, the corresponding number of second mud discharge channels is 1, 2, 3 or 4.

[0055] As an alternative, several second sealing elements are also included to cooperate with the second sludge discharge channel. These second sealing elements can be installed on the second sludge discharge channel and can block it, preventing bone cement in the fluid channel from flowing out through the blocked channel. This structure adopts a universal design. Specifically, for example, if there are four directions of the second sludge discharge channel on the second hollow tube, and each direction corresponds to a single second sludge discharge channel, then there are four such channels. When bone cement needs to be discharged in one or more directions, second sealing elements can be installed on the remaining channels to block them, ensuring that at least one direction of the channel remains unobstructed, thus enabling the directional flow of bone cement.

[0056] Unlike Embodiment 1, in this embodiment, the third end unit includes a third hollow tip and a third plug that mates with the third hollow tip. A third hollow channel is provided within the third hollow tip, and the third plug is disposed within the third hollow channel, sealing the third hollow channel. In actual use, the third plug can be removed. After the first hollow tube, the second hollow tube, and the third hollow tip are installed, the third plug is inserted into the third hollow channel through a fluid channel, and external force is applied to ensure a tight fit between the third plug and the third hollow channel, thus sealing the third hollow channel. After sealing, bone cement can be injected.

[0057] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A pedicle screw, comprising a pedicle screw body, wherein the pedicle screw body comprises a first hollow tube, a second hollow tube, and a third terminal unit; The first hollow tube, the second hollow tube, and the third end unit are connected in sequence to form a pedicle screw body; Threads are respectively provided on the outer wall of the first hollow tube, the outer wall of the second hollow tube, and the outer wall of the third end unit. The threads on the outer wall of the first hollow tube, the threads on the outer wall of the first hollow tube, and the threads on the outer wall of the third end unit are arranged sequentially and cooperate with each other. Its features are, One end of the second hollow tube is connected to the first hollow tube, and the other end of the second hollow tube is connected to the third end unit; the second hollow tube is provided with a plurality of second mud discharge channels for bone cement to flow out in the circumferential direction, and the second mud discharge channels are strip-shaped; Along the circumferential direction of the second hollow tube, the second mud discharge channel is distributed in N directions of the second hollow tube, and N is a natural number and N=1~6; The inner wall of the first hollow tube and the inner wall of the second hollow tube together form a fluid channel for injecting bone cement. The fluid channel is connected to the second mud outlet channel and the bone cement injected through the fluid channel can flow out to the outside of the second hollow tube through the fluid channel. The third end unit is a third solid tip; or the third end unit includes a third hollow tip and a third plug that cooperates with the third hollow tip, the third hollow tip is provided with a third hollow channel, the third plug is provided in the third hollow channel and the third plug can block the third hollow channel.

2. The pedicle screw according to claim 1, characterized in that, The first hollow tube has a first channel mark at the end away from the second hollow tube that cooperates with the second sludge discharge channel, and the direction of the second sludge discharge channel can be identified by the first channel mark.

3. The pedicle screw according to claim 1 or 2, characterized in that, The third end unit is a third solid tip. The first hollow tube, the second hollow tube, and the third end unit are connected in sequence and integrally formed. The fluid channel is not connected to the third end unit and the bone cement injected through the fluid channel cannot flow out through the third end unit. Alternatively, the third end unit may include a third hollow tip and a third plug that cooperates with the third hollow tip. The third hollow tip is provided with a third hollow channel. The third plug is disposed in the third hollow channel and can seal the third hollow channel. The third plug and the third hollow tip are detachably connected. The first hollow tube, the second hollow tube, and the third hollow tip are sequentially connected as a whole and are integrally formed.

4. The pedicle screw according to claim 3, characterized in that, The third hollow channel is connected to the fluid channel; the third plug can be sent into the third hollow channel through the fluid channel and, under the action of external force, the third plug is tightly fitted to the third hollow channel to seal the third hollow channel and prevent the bone cement injected through the fluid channel from flowing out through the third end unit.

5. The pedicle screw according to any one of claims 1 to 4, characterized in that, It also includes several second sealing elements that cooperate with the second sludge discharge channel. The second sealing elements can be installed on the second sludge discharge channel and can block the second sludge discharge channel and prevent the bone cement in the fluid channel from flowing out through the blocked second sludge discharge channel.

6. The pedicle screw according to any one of claims 1 to 5, characterized in that, It also includes the pedicle screw tail connected to the pedicle screw body.

7. The pedicle screw according to claim 6, characterized in that, The inner wall of the pedicle screw tail is threaded.

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