A device for removing an implant screw from a bone fracture patient

Abstract

The utility model relates to medical auxiliary instrument technical field provides a kind of bone injury patient implant screw's taking-out device, including ring main body, internal fixation assembly and external fixation assembly.The internal fixation assembly includes expansion cylinder and expansion column, the expansion cylinder is set along the inner ring side of ring main body Circumferentially, expansion column can pass through the inner ring of ring main body, and expansion cylinder is expanded tightly.One end of expansion column located outside expansion cylinder is equipped with a rotating head.The external fixation assembly includes tightening cylinder and hoop ring, tightening cylinder is circumferentially arranged at the outer edge of ring main body, hoop ring can be sleeved on tightening cylinder, and tightening cylinder can be tightened.The bone injury patient implant screw's taking-out device proposed in the utility model can greatly improve the friction between it and implant screw, in the process of taking out implant screw, it can effectively avoid the problem of skidding, especially suitable for the case that the internal hexagonal groove of implant screw is rounded, and it is difficult to take out.

Description

Technical Field

[0001] This application relates to the field of medical assistive device technology, and more specifically, to a device for removing implanted screws in patients with bone injuries. Background Technology

[0002] The content in this section provides only background information related to this application and may not constitute prior art.

[0003] Plate and screw internal fixation is widely used in various orthopedic fracture surgeries. However, because most bone screws used clinically are metal-based, they integrate tightly with bone tissue after six months or even years and are corroded by tissue fluid. This causes the grooves on the heads of the commonly used hexagonal bone screws to become smooth due to wear from the first surgery, making some screws slippery and difficult to remove. Plate and screw fixation for fractures has become the most common internal fixation method today, with hexagonal screws being the most frequently used screws in orthopedics. After fracture healing, the plate and screws need to be removed. Because the screws are under significant stress within the body, they often deform, greatly increasing frictional resistance and making removal very difficult, often resulting in slippage. The stress on the screws also makes the threads between the screw tail and the locking hole on the plate more prone to deformation, further increasing the difficulty of removal and significantly raising the chance of slippage during forceful rotation. "Screw stripping" significantly increases the difficulty of removal, prolongs the operation time, increases the chance of infection, and can lead to serious complications such as removal failure or even refracture.

[0004] To address the aforementioned issues, Chinese patent document CN101856265A discloses an orthopedic stripped screw remover. This orthopedic stripped screw remover primarily utilizes a conical rod to expand the hollow cutting head, thereby allowing the expanded cutting head to tightly engage with the screw tail groove. Then, by twisting the handle of the main rod sleeve, the stripped screw can be unscrewed and removed.

[0005] However, the aforementioned related technologies have the following drawbacks: The technical solutions disclosed in the patents mainly utilize the pressure generated by the expansion of the wrench head to increase the resistance with the inner wall of the groove, thereby avoiding the slippage problem caused by insufficient resistance when using a conventional Allen wrench. However, even with increased pressure, if the wrench head is expanded into the groove after stripping occurs, the actual contact area between the wrench head and the side wall of the groove will be very small due to the small size of the groove for the inserted screw tail, resulting in insufficient resistance and thus causing stripping. Summary of the Invention

[0006] In order to solve the above-mentioned technical problems, the purpose of this application is to provide a device for removing implanted screws in patients with bone injuries, which can significantly increase the friction between the device and the implanted screw, and effectively avoid slippage during the removal of the implanted screw. It is especially suitable for situations where the edges of the hexagonal groove of the implanted screw are rounded, making it difficult to remove.

[0007] The objective of this application is achieved through the following technical solution:

[0008] A device for removing implanted screws in patients with bone injuries includes: a ring body, an internal fixation component, and an external fixation component;

[0009] The internal fixation assembly includes an expansion cylinder and an expansion pin. The expansion cylinder is arranged circumferentially along the inner ring side of the ring body, and the expansion pin can pass through the inner ring of the ring body and can expand the expansion cylinder.

[0010] A rotating head is provided at one end of the expansion column located outside the expansion cylinder;

[0011] The external fixing assembly includes a tightening cylinder and a clamping ring. The tightening cylinder is circumferentially disposed at the outer edge of the ring body. The clamping ring can be sleeved on the tightening cylinder and can tighten the tightening cylinder.

[0012] In some possible embodiments, the expansion cylinder is a first conical cylinder structure composed of multiple first expansion plates spliced ​​together, and the diameter of the expansion cylinder decreases sequentially along the extension direction.

[0013] In some possible embodiments, the inner wall of the expansion cylinder is provided with internal threads, and the outer periphery of the expansion column is provided with external threads that match the internal threads, wherein the direction of the external threads is opposite to the direction of the threads of the implanted screw.

[0014] In some possible embodiments, the tightening cylinder is a second conical cylinder structure composed of multiple second tightening plates spliced ​​together, and the diameter of the tightening cylinder increases sequentially along the extension direction.

[0015] In some possible embodiments, the clamping ring is a nut that can be threadedly connected to the tightening cylinder.

[0016] In some possible embodiments, both the outer wall of the expansion cylinder and the inner wall of the tightening cylinder are provided with anti-slip textures.

[0017] In some possible embodiments, the rotating head is a hexagonal nut structure.

[0018] In some possible embodiments, an internal hexagonal locking hole is provided on the end face of the hexagonal nut structure.

[0019] In summary, after adopting the above technical solution, this utility model has at least the following beneficial effects:

[0020] In this application, the internal fixation component is mainly used to increase the friction between the internal fixation component and the inner wall of the recessed groove at the implanted screw head. Simultaneously, the external fixation component is used to increase the friction between the external fixation component and the outer ring sidewall of the implanted screw head. One method involves using an expansion pin inserted into an expansion cylinder to expand the cylinder, increasing the pressure between the expansion cylinder and the inner wall of the recessed groove at the implanted screw head, thus increasing friction. Simultaneously, a clamping ring tightens the clamping cylinder, increasing the pressure between the clamping cylinder and the outer ring wall of the implanted screw head, thereby increasing friction. Therefore, the overall contact area is effectively increased through the clamping cylinder, significantly increasing the friction. This effectively prevents slippage during screw removal, especially useful when the edges of the hexagonal recess of the implanted screw are rounded, making removal difficult. Attached Figure Description

[0021] Figure 1 This is a partial cross-sectional view of an embodiment of this application in an exploded state;

[0022] Figure 2 This is a front cross-sectional view of an embodiment of this application in an exploded state;

[0023] Figure 3 This is an exploded view of an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the installation structure of the ring body in an embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the installation structure of the rotating head in an embodiment of this application.

[0026] Icons: 1-Ring body; 2-Tightening cylinder; 3-Tightening column; 4-Rotating head; 5-Tightening cylinder; 6-Clamping ring; 7-First tightening plate; 8-Second tightening plate; 9-Internal hexagonal socket; 10-Internal thread; 11-External thread; 12-Inserted screw; 13-Groove; 14-Screw head. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Example

[0028] The following is for reference Figures 1 to 4 This application will be described in further detail.

[0029] Reference Figures 1-4 This embodiment provides a device for removing implanted screws in patients with bone injuries. It is mainly used to remove implanted screws 12 from the patient's body. The implanted screw 12 includes a screw rod and a screw head 14, and a groove 13 is provided at the end of the screw head 14.

[0030] The groove 13 at the end of the screw head 14 of the implanted screw 12 is usually a hexagonal groove. Some of the hexagonal grooves of the implanted screw 12 become smooth due to wear during surgery. When removing the screw, some may slip and become difficult to unscrew using a standard hexagonal wrench. The technical solution proposed in this embodiment is mainly applicable to situations where the edges of the hexagonal groove are rounded, making removal difficult.

[0031] The device for removing implanted screws in patients with bone injuries proposed in this embodiment includes: a ring body 1, an internal fixation assembly, and an external fixation assembly. The internal fixation assembly includes a tightening cylinder 2 and a tightening pin 3. The tightening cylinder 2 is arranged circumferentially along the inner ring side of the ring body 1, and the tightening pin 3 can pass through the inner ring of the ring body 1 and tighten the tightening cylinder 2. The aforementioned internal fixation assembly is mainly used to increase the frictional force between the screw and the inner wall of the groove 13 at the screw head 14 of the implanted screw 12. Simultaneously, the external fixation assembly is used to increase the frictional force between the screw and the outer ring sidewall of the screw head 14 of the implanted screw 12. For details, please refer to... Figure 1 , Figure 2 and Figure 3 After fastening the ring body 1 onto the head 14 of the implantation screw 12, the expansion cylinder 2 extends into the groove 13 of the implantation screw 12. The expansion pin 3 passes through the inner ring of the ring body 1 and extends into the expansion cylinder 2. This expands the expansion cylinder 2, which then fits tightly against the inner wall of the groove 13. The pressure generated between the expansion cylinder 2 and the inner wall of the groove 13 increases friction, effectively preventing relative slippage and stripping of the screw when rotating the implantation screw 12.

[0032] Please refer to Figures 1-3 In this embodiment, the external fixation assembly includes a tightening cylinder 5 and a clamping ring 6. The tightening cylinder 5 is circumferentially disposed on the outer edge of the ring body 1. The clamping ring 6 can be fitted onto the tightening cylinder 5 and can tighten the tightening cylinder 5. After the ring body 1 is fastened onto the head 14 of the implanted screw 12, the tightening cylinder 5 will be fitted onto the head 14 of the implanted screw 12. After the tightening cylinder 5 is tightened by the clamping ring 6, the pressure between the tightening cylinder 5 and the outer ring wall of the head 14 of the implanted screw 12 can be increased, thereby increasing the friction between them. Therefore, the friction is greatly increased by increasing the contact area between the tightening cylinder 5 and the side wall of the head 14 of the implanted screw 12. In this way, the slippage problem that occurs during the removal of the implanted screw 12 can also be further avoided.

[0033] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 5 A rotating head 4 is provided at one end of the tensioning column 3 located outside the tensioning cylinder 2. The rotating head 4 is mainly used to facilitate the rotation of the tensioning cylinder 2 using external tools, thereby achieving the purpose of rotating the entire removal device. Since the internal fixation component and the external fixation component are connected to the head 14 of the implanted screw 12, rotating the rotating head 4 will drive the implanted screw 12 to rotate, thereby facilitating the removal of the implanted screw 12.

[0034] It is worth noting that, please refer to Figure 1 , Figure 2 and Figure 4 In this embodiment, the expansion cylinder 2 is a first conical cylindrical structure composed of multiple first expansion plates 7 spliced ​​together, with the diameter of the expansion cylinder 2 decreasing sequentially along the extension direction. Multiple first expansion plates 7 are sequentially spliced ​​around the inner ring edge of the main body 1 to form the first conical cylindrical structure. The actual diameter of one end of the smaller-diameter first conical cylindrical structure is smaller than the diameter of the groove 13 opened on the screw head 14 of the implanted screw 12, thus allowing one end of the smaller-diameter first conical cylindrical structure to easily extend into the groove 13. Specifically, there is a gap between any two adjacent first expansion plates 7, meaning there is no connection between them. Therefore, when the expansion column 3 extends into the expansion cylinder 2, it can easily expand the expansion cylinder 2 without causing significant deformation of the expansion cylinder 2 in the circumferential direction, thereby preventing the frictional force between the expansion cylinder 2 and the inner wall of the groove 13 after expansion.

[0035] It is worth noting that the first conical cylinder structure formed by splicing the first tensioning plates 7 into the tensioning cylinder 2 is merely one implementation method in this embodiment, and is not limited to using the structure described above to achieve the desired effect. In other embodiments, other structures can also be used. For example, in other embodiments, the tensioning cylinder 2 can also be directly adopted as an integrally molded structure. Furthermore, the tensioning cylinder 2 can also adopt a straight cylinder structure. It should be further noted that if the above-mentioned straight cylinder structure is used, the diameter of the tensioning column 3 needs to be larger than the inner diameter of the straight cylinder structure.

[0036] For further details, please refer to... Figure 4 In this embodiment, the tensioning cylinder 2 is composed of four first tensioning plates 7 joined together. In other embodiments, the tensioning cylinder 2 may also be composed of other numbers of first tensioning plates 7 joined together.

[0037] Please refer to Figure 2 and Figure 4In this embodiment, the inner wall of the expansion cylinder 2 is provided with an internal thread 10, and the expansion pin 3 is provided with an external thread 11 that matches the internal thread 10. The direction of rotation of the external thread 11 is opposite to that of the thread of the implanted screw 12. By providing the internal thread 10 on the expansion cylinder 2 and the matching external thread 11 on the expansion pin 3, the expansion pin 3 and the expansion cylinder 2 can be threadedly connected. Thus, by rotating the expansion pin 3, the expansion pin 3 can be inserted into the expansion cylinder 2, and the expansion cylinder 2 can be gradually expanded. Specifically, by rotating the expansion pin 3, its external thread 11 engages with the internal thread 10 of the expansion cylinder 2, pushing the expansion pin 3 to move axially to expand the first expansion piece 7. Without the above-mentioned threaded connection structure, the expansion pin 3 can only be inserted into the expansion cylinder 2 after applying force in the axial direction (for example, the prior art solution disclosed in the patent document in the background of this application adopts the above structure). Force analysis shows that applying force along the axis of the expansion pin 3 indirectly applies force along the axis of the implanted screw 12, causing the screw 12 to interact with the patient's bone in the axial direction, which could potentially lead to further bone injury. However, with the threaded connection method disclosed in this embodiment, the expansion pin 3 applies force in the circumferential direction as it extends into the expansion cylinder 2, thus indirectly causing the implanted screw 12 to rotate. The purpose of this application is to remove the implanted screw 12 by rotation, therefore, it will not cause additional damage to the patient's bone.

[0038] In this embodiment, after rotating the expansion pin 3, the expansion pin 3 can extend into the expansion cylinder 2. Simultaneously, the tangential force generated by this rotation acts on the implanted screw 12, causing the implanted screw 12 to rotate. Since the rotation direction of the external thread 11 is opposite to the thread direction of the implanted screw 12, the rotational tendency of the expansion pin 3 actually helps to loosen the implanted screw 12, making it easier to remove.

[0039] It should be noted that, in this embodiment, the internal thread 10 of the expansion cylinder 2 is actually tapped on the first expansion plate 7 that makes up its structure. The internal thread 10 is tapped in an orderly manner on the first expansion plate 7 and will not affect the engagement of the external thread 11 on the expansion column 3. Furthermore, in this embodiment, the internal thread 10 needs to be able to effectively engage with the external thread 11 even when the first expansion plate 7 is in a parallel state with the expansion column 3 during the expansion process. In this way, the first expansion plate 7 will not affect the thread engagement relationship during the expansion process.

[0040] Specifically, in this embodiment, the inner ring surface of the ring body 1 is also provided with an internal thread (not shown in the figure) that mates with the external thread 11 on the expansion pin 3. This internal thread can also engage with the internal thread 10 on the expansion cylinder 2, allowing the expansion pin 3 to smoothly enter the expansion cylinder 2 along the ring body 1 after rotation. The internal thread on the inner ring surface of the ring body 1 also serves to stabilize the ring, facilitating the engagement of the expansion pin 3 with the internal thread 10 on the expansion cylinder 2 when the expansion pin 3 rotates.

[0041] Please refer to Figure 3 and Figure 4 In this embodiment, the tightening cylinder 5 is a second conical cylindrical structure composed of multiple second tightening plates 8, with the diameter of the tightening cylinder 5 increasing sequentially along the extension direction. Multiple second tightening plates 8 are sequentially spliced ​​around the inner ring edge of the ring body 1 to form the second conical cylindrical structure (this second conical cylindrical structure is different from the first conical cylindrical structure composed of the first tightening plates 7). Unlike the tightening cylinder 2, the tightening cylinder 5 has a larger diameter at the end furthest from the ring body 1. This forms an outwardly opening structure, facilitating its placement on the head 14 of the implanted screw 12. Similarly, the tightening cylinder 5, composed of multiple second tightening plates 8, allows for convenient clamping of the ring 6, with the multiple second tightening plates 8 pressing against the side wall of the head 14 during clamping.

[0042] For further details, please refer to Figures 1-3 In this embodiment, the clamping ring 6 is a nut, which can be threadedly connected to the tightening cylinder 5. The structural principle and technical effect of the nut and tightening cylinder 5 threaded connection are basically the same as those of the tightening column and the expansion cylinder 2. By rotating the nut, the second expansion plate 8 can be tightened, so that the tightened second expansion plate 8 abuts against the outer peripheral wall of the screw head 14 of the implanted screw 12. Similarly, the movement of the nut in the axial direction is accomplished by rotation, which does not actually affect the movement of the implanted screw 12 in the axial direction. Thus, the movement of the implanted screw 12 in the axial direction can be avoided from affecting the patient's bone. Furthermore, in this embodiment, the thread direction of the tightening cylinder 5 is also opposite to that of the thread direction of the implanted screw 12. Thus, when the nut is rotated, the tangential force generated indirectly acts on the implanted screw 12, which will cause the implanted screw 12 to loosen. This also makes it easier to remove the implanted screw 12.

[0043] Similarly, the aforementioned tightening cylinder 5, which is a second conical cylinder structure composed of multiple second tightening plates 8, is merely one implementation method of this embodiment. It is not limited to using the structure described above to achieve the desired effect; other structures can also be used in other embodiments. For example, in other embodiments, the tightening cylinder 5 can also be a one-piece molded structure. Furthermore, the tightening cylinder 5 can also be a straight cylinder structure. In this embodiment, four second tightening plates 8 are used to form the second conical cylinder structure. However, in other embodiments, the number of second tightening plates 8 constituting the tightening cylinder 5 can also be changed.

[0044] In fact, in this embodiment, the internal thread 10 needs to be able to effectively engage with the thread on the corresponding clamping ring 6 when the second tightening plate 8 is in a parallel state with the outer wall of the implanted screw 12 in the axial direction during the tightening process. In this way, the second tightening plate 8 will not affect the thread engagement relationship during the tightening process.

[0045] In some embodiments of this example, the outer wall of the expansion cylinder 2 and the inner wall of the tightening cylinder 5 are provided with anti-slip textures (not shown in the figure). These anti-slip textures can further prevent slippage between the expansion cylinder and the tightening cylinder 5. Specifically, the anti-slip textures can be diagonal patterns or grid patterns, etc.

[0046] Please refer to Figure 5 In this embodiment, the aforementioned rotating head 4 has a hexagonal nut structure. The rotating head 4 with its hexagonal nut structure allows for easy rotation using an external wrench. Specifically, the rotating head 4 is welded to the end of the expansion joint 3, and its hexagonal nut structure is compatible with a standard wrench.

[0047] Furthermore, in this embodiment, an internal hexagonal locking hole 9 is provided on the end face of the hexagonal nut structure. The aforementioned internal hexagonal locking hole 9 can be rotated using an internal hexagonal wrench, thus allowing the rotating head 4 to be rotated using various tools.

[0048] In use, first, place the ring body 1 over the head 14 of the implanted screw 12 to be removed. At this time, the expansion cylinder 2 extends into the groove 13 of the screw head 14. Simultaneously, the tightening cylinder 5 is fitted onto the screw head 14. Then, rotate the rotating head 4 and the nut using an external tool. During this process, the rotating head 4 will drive the expansion column into the expansion cylinder, which will expand the expansion cylinder 2. The expanded expansion cylinder 2 will then tightly abut against the inner wall of the groove 13; while the nut will gradually tighten the tightening cylinder 5, which will then tightly abut against the outer wall of the screw head 14. After completing the above operations, a regular wrench or Allen wrench can be used to continue rotating the rotating head 4, so that the rotating head 4 indirectly rotates and removes the implanted screw 12.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for removing implanted screws in patients with bone injuries, characterized in that: Includes the ring body, internal fixation components, and external fixation components; The internal fixation assembly includes an expansion cylinder and an expansion pin. The expansion cylinder is arranged circumferentially along the inner ring side of the ring body, and the expansion pin can pass through the inner ring of the ring body and can expand the expansion cylinder. A rotating head is provided at one end of the tensioning column located outside the tensioning cylinder; The external fixing assembly includes a tightening cylinder and a clamping ring. The tightening cylinder is circumferentially located at the outer edge of the ring body, and the clamping ring can be fitted onto the tightening cylinder and tighten the tightening cylinder.

2. The device for removing implanted screws in patients with bone injuries according to claim 1, characterized in that: The expansion cylinder is a first conical cylinder structure composed of multiple first expansion plates spliced ​​together, and the diameter of the expansion cylinder decreases sequentially along the extension direction.

3. The device for removing implanted screws in patients with bone injuries according to claim 2, characterized in that: The inner wall of the expansion cylinder is provided with an internal thread, and the outer periphery of the expansion column is provided with an external thread that matches the internal thread. The direction of the external thread is opposite to the direction of the thread of the implanted screw.

4. The device for removing implanted screws in patients with bone injuries according to claim 3, characterized in that: The tightening cylinder is a second conical cylinder structure composed of multiple second tightening plates spliced ​​together, and the diameter of the tightening cylinder increases sequentially along the extension direction.

5. The device for removing implanted screws in patients with bone injuries according to claim 1, characterized in that: The clamping ring is a nut, which can be threadedly connected to the tightening cylinder.

6. The device for removing implanted screws in patients with bone injuries according to claim 1, characterized in that: Both the outer wall of the expansion cylinder and the inner wall of the tightening cylinder are provided with anti-slip textures.

7. The device for removing implanted screws in patients with bone injuries according to claim 1, characterized in that: The rotating head has a hexagonal nut structure.

8. The device for removing implanted screws in patients with bone injuries according to claim 7, characterized in that, The hexagonal nut structure has an internal hexagonal locking hole on its end face.

Images