Magnetic driving force screw for femoral neck fracture

Abstract

The invention discloses a magnetic driving force screw for femoral neck fracture, and relates to the technical field of medical instruments. The sleeve is arranged in the shell, and the sleeve is fixedly connected with the shell; the extension rod is arranged in the sleeve, the extension rod is in circumferential limiting connection with the sleeve, and one end of the extension rod extends out of the shell; the transmission assembly is arranged in the shell and comprises a screw rod, a speed reducer and a permanent magnet, one end of the screw rod is inserted into the extension rod and is in threaded connection with the extension rod, the other end of the screw rod is in circumferential limiting connection with a first transmission shaft of the speed reducer, a second transmission shaft of the speed reducer is fixedly connected with the permanent magnet, and the permanent magnet is in axial limiting connection with the shell; the permanent magnet is used for being controlled by an external magnetic field to rotate in the circumferential direction to drive the screw to rotate, so that the extension rod axially moves in the sleeve, and the tightness of the two ends of the bone at the fracture position is adjusted. According to the design, noninvasive adjustment is achieved through magnetic driving, secondary trauma can be reduced, and treatment safety and convenience are improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a magnetically driven screw for femoral neck fractures. Background Technology

[0002] Femoral neck fractures are a common type of fracture in clinical practice, especially prevalent among the elderly, accounting for 3.6% of all fractures and nearly half of all hip fractures. Furthermore, with the increasing aging of the population, its incidence is rising annually. Although advancements in medical imaging technology, internal fixation materials and designs, treatment concepts, and surgical techniques have significantly improved the treatment outcomes of femoral neck fractures, the incidence of complications such as poor fracture reduction, nonunion, and avascular necrosis of the femoral head remains high, particularly among younger patients, who face a more significant risk of femoral head necrosis and nonunion. These complications not only affect fracture healing but can also lead to femoral head collapse, severely reducing patients' quality of life.

[0003] In traditional techniques, fixation using three hollow screws inserted into the femoral neck suffers from problems such as femoral neck shortening, weak fixation strength, and screw loosening and failure, requiring further surgery for repair. Similarly, fixation using proximal femoral intramedullary nails also faces challenges such as femoral neck shortening, inability to adjust femoral neck length in a timely manner, lack of effective mechanical stimulation, and the inability to promote fracture healing through dynamic stretching and compression of the fracture ends. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, the present invention provides a magnetically driven force screw for femoral neck fractures.

[0005] To achieve the above objectives, the present invention provides a magnetically driven screw for femoral neck fractures, comprising: A housing for insertion into the femoral neck, the housing having a receiving space; A sleeve is disposed inside the outer casing, and the sleeve is fixedly connected to the outer casing; An extension rod is disposed inside the sleeve, and the extension rod is circumferentially limited to the sleeve, with one end of the extension rod extending out of the outer shell; A transmission assembly is disposed within the housing. The transmission assembly includes a screw, a reducer, and a permanent magnet. One end of the screw is inserted into the extension rod and threadedly connected to the extension rod. The other end of the screw is circumferentially limited and connected to the first transmission shaft of the reducer. The second transmission shaft of the reducer is fixedly connected to the permanent magnet. The permanent magnet is axially limited and connected to the housing. The permanent magnet is used to rotate circumferentially under the control of an external magnetic field, so as to drive the screw to rotate, so that the extension rod can move axially within the sleeve, thereby adjusting the tightness of the two ends of the bone at the fracture site.

[0006] Preferably, the screw includes a first threaded portion and a first limiting portion that are fixedly connected. The first threaded portion is used to be inserted into the extension rod and threadedly connected to the extension rod. The diameter of the first limiting portion is larger than the diameter of the first threaded portion. The end face of the first limiting portion that is connected to the first threaded portion abuts against the extension rod. A first slot is provided at the end of the first limiting portion away from the first threaded portion. The first slot is used for inserting the first drive shaft. The first slot and the first drive shaft are connected by a coupling to transmit torque.

[0007] Preferably, a second groove is provided on the circumferential sidewall of the extension rod, and a second boss is provided on the inner wall of the sleeve; The extension rod includes an axially arranged first end and a second end. The first end is used to insert into the sleeve and extend into the housing. The first end is also used for inserting the screw. The second end extends out of the sleeve and the housing. The second groove extends to the second end of the extension rod. The axial length of the second boss is adapted to the axial length of the sleeve. When the sleeve is fitted with the extension rod, the second boss is inserted into the second groove to make the extension rod circumferentially limited to the sleeve. When the screw rotates, the extension rod moves axially within the sleeve.

[0008] Preferably, a second limiting part is provided at one end of the sleeve, the diameter of the second limiting part is larger than the diameter of the outer shell, and the end of the sleeve away from the second limiting part is used to insert into the outer shell; The sleeve is threadedly connected to the outer shell to axially limit the sleeve and the outer shell. The threads between the sleeve and the outer shell and between the screw and the extension rod are opposite in direction to ensure that the sleeve and the outer shell are circumferentially limited when the screw rotates and causes the extension rod to rotate.

[0009] Preferably, the permanent magnet has a through hole at its axial center, and the second drive shaft of the reducer is inserted into the first through hole through one end of the permanent magnet and fixedly connected to the permanent magnet. A connecting rod is provided inside the housing, and a second slot is provided at the end of the receiving space inside the housing. The connecting rod has a third end and a fourth end. The third end is used to insert into the first through hole and is fixedly connected to the permanent magnet. The fourth end is used to insert into the second slot. A third slot is also provided on the second slot. The third slot is located between the second slot and the receiving space. The diameter of the third slot is larger than that of the second slot. The third slot is used for the installation of a deep groove ball bearing. When the fourth end is inserted into the second slot, the deep groove ball bearing is sleeved on the fourth end. When the permanent magnet rotates, the deep groove ball bearing is used to bear the radial force of the connecting rod.

[0010] Preferably, the first end of the extension rod extends out of the sleeve and abuts against the inner wall of the housing. A sealing ring mounting groove is provided on the circumferential side wall of the first end. The sealing ring mounting groove is used to install a sealing ring, and the sealing ring is used to make the extension rod and the inner wall of the housing movably seal.

[0011] Preferably, a third boss is provided on the circumferential sidewall of the first limiting part, and a thrust ball bearing is sleeved on the first limiting part, wherein the thrust ball bearing is located on the side of the third boss away from the first threaded part; The thrust ball bearing abuts against the third boss and the reducer at both axial ends to withstand the axial force of the reducer.

[0012] Preferably, a thrust ring is provided between the thrust ball bearing and the reducer, with the two axial ends of the thrust ring abutting against the thrust ball bearing and the reducer respectively, and the thrust ring is used to enhance the axial limiting between the reducer and the screw.

[0013] Preferably, a threaded cap is provided at the second end of the extension rod, the second end of the extension rod is used to insert the threaded cap, a second through hole is provided on the circumferential sidewall of the extension rod, and a third through hole is provided on the circumferential sidewall of the threaded cap. The second through hole and the third through hole are used to insert a first pin so that the threaded cap is fixedly connected to the extension rod. The circumferential sidewall of the threaded cap is provided with threads.

[0014] Preferably, a fourth through hole is provided on the circumferential sidewall of the outer shell. The fourth through hole is located at the end of the outer shell away from the threaded cap. The fourth through hole is used for the insertion of a bone screw to restrict the movement of the outer shell.

[0015] Based on this, the beneficial effects of the present invention are as follows: This invention implants the outer shell into the femoral neck from one side of the fracture, allowing the end of the extension rod to extend to the other side of the fracture. An external magnetic field (with a matching external drive coil) drives the permanent magnet to rotate, which is then converted into axial extension and retraction of the extension rod via a reducer and screw. This achieves non-invasive locking and loosening adjustment at both ends of the fracture. Compared with traditional techniques, the fixation force and femoral neck length can be dynamically adjusted without secondary invasive operations. Furthermore, if necessary, tensile-compression mechanical loading can be applied to the fracture ends to stimulate fracture healing, significantly reducing patient trauma and surgical risks, while also reducing the economic cost of repeated treatments and improving treatment convenience and patient compliance. Attached Figure Description

[0016] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This schematic diagram illustrates the structure of a magnetically driven force screw according to one embodiment of the present invention. Figure 2 A schematic cross-sectional view of a magnetically driven force screw according to one embodiment of the present invention; Figure 3 This illustration represents one embodiment of the present invention. Figure 2 Enlarged view of point A in the middle; Figure 4 This illustration represents one embodiment of the present invention. Figure 2 Enlarged view of point B in the middle; Figure 5 This is a schematic diagram illustrating the installation of the extension rod, sleeve, and housing according to one embodiment of the present invention. Figure 6 This illustration represents one embodiment of the present invention. Figure 2 Enlarged view of point C in the middle; Figure 7 This illustration represents one embodiment of the present invention. Figure 2 Enlarged view of point D in the middle; Figure 8 The diagram illustrates the usage state of a magnetically driven force screw according to one embodiment of the present invention. Explanation of reference numerals in the attached drawings: 10-outer shell, 101-accommodating space, 102-connecting rod, 1021-third end, 1022-fourth end, 103-second slot, 1031-third slot, 104-fourth through hole, 105-fourth slot; 20-Sleeve, 201-Second boss, 202-Second limiting part; 30-Extension rod, 301-Second groove, 302-First end, 303-Second end, 3031-Second through hole, 304-Sealing ring mounting groove, 305-Threaded cap, 3051-Third through hole; 40-Transmission assembly, 401-Screw, 4011-First threaded part, 4012-First limiting part, 40121-First slot, 40122-Third boss, 402-Reducer, 4021-First drive shaft, 4022-Second drive shaft, 403-Permanent magnet, 4031-First through hole; 501 - Deep groove ball bearing, 502 - Thrust ball bearing, 503 - Thrust ring, 601 - Second pin, 602 - Bone plate, 603 - Third pin. Detailed Implementation

[0017] 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, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a," "the," and "the" as used in the embodiments of this application are also intended to include the plural forms unless the context clearly indicates otherwise.

[0019] It should be understood that although the terms first, second, third, etc., may be used to describe related structures in the embodiments of this application, these related structures should not be limited to these terms. These terms are only used to distinguish related structures from each other.

[0020] Depending on the context, the word "if" as used here can be interpreted as "when" or "when". Similarly, depending on the context, the phrase "if determined" can be interpreted as "when determined" or "when (the condition or event of the statement) is detected".

[0021] It should be noted that the directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should also be understood that when it is mentioned that an element is formed "upper" or "lower" of another element, it can not only be formed directly "upper" or "lower" of the other element, but also indirectly "upper" or "lower" of the other element through an intermediate element.

[0022] Figure 1 This schematic diagram illustrates the structure of a magnetically driven force screw according to one embodiment of the present invention. Figure 2 A schematic cross-sectional view of a magnetically driven screw according to one embodiment of the present invention is shown, such as... Figure 1 , 2 As shown, the present invention provides a magnetically driven force screw for femoral neck fractures, the solution of which includes: The outer casing 10 is for insertion into the femoral neck, and the outer casing 10 has a receiving space 101; Sleeve 20 is disposed inside housing 10 and is fixedly connected to housing 10; An extension rod 30 is disposed inside the sleeve 20. The extension rod 30 is circumferentially limited to the sleeve 20, and one end of the extension rod 30 extends out of the outer shell 10. The transmission assembly 40 is disposed inside the housing 10. The transmission assembly 40 includes a screw 401, a reducer 402 and a permanent magnet 403. One end of the screw 401 is inserted into the extension rod 30 and threadedly connected to the extension rod 30. The other end of the screw 401 is circumferentially limited and connected to the first transmission shaft 4021 of the reducer 402. The second transmission shaft 4022 of the reducer 402 is fixedly connected to the permanent magnet 403. The permanent magnet 403 is axially limited and connected to the housing 10. The permanent magnet 403 is used to rotate circumferentially under the control of an external magnetic field, so as to drive the screw 401 to rotate, so that the extension rod 30 can move axially within the sleeve 20, thereby adjusting the tightness of the two ends of the bone at the fracture site.

[0023] With this configuration, when the permanent magnet 403 rotates under the control of an external magnetic field, since the permanent magnet 403 is connected to the second drive shaft 4022 of the reducer 402, the reducer 402 is controlled to rotate synchronously. Through the deceleration effect inside the reducer 402, the first speed at the second drive shaft 4022 is reduced to the second speed at the first drive shaft 4021. One end of the screw 401 is circumferentially limited to the first drive shaft 4021, so that the screw 401 rotates synchronously at the second speed. The other end of the screw 401 is inserted into the extension rod 30 and threadedly connected to the extension rod 30. The extension rod 30 is circumferentially limited to the sleeve 20, and the sleeve 20 is fixedly connected to the outer shell 10, thereby realizing the axial movement of the extension rod 30 within the sleeve 20.

[0024] During installation, the outer shell 10 is inserted into the femoral neck from one side of the femoral neck fracture, and the end of the extension rod 30 is inserted into the other side of the femoral neck fracture. When the extension rod 30 moves in extension and retraction, the two sides of the femoral neck fracture move closer or further apart, thereby adjusting the tightness of the two sides of the femoral neck fracture. Once the two sides of the femoral neck fracture are locked, if they become loose later, the permanent magnet 403 can be rotated by an external magnetic field to achieve non-invasive remote adjustment without the need for surgery, thus reducing bone damage.

[0025] Meanwhile, the reducer 402 can reduce the rotational speed of the high-speed, uncontrollable permanent magnet 403. The lower speed can prevent the extension rod 30 from being overextended or overcontracted, thus achieving controllable adjustment and improving control accuracy.

[0026] Furthermore, Figure 3 This illustration represents one embodiment of the present invention. Figure 2 Enlarged view of point A in the middle. Figure 4 This illustration represents one embodiment of the present invention. Figure 2 Enlarged view at point B in the middle. Figure 5 This schematic diagram illustrates the installation of the extension rod, sleeve, and housing according to one embodiment of the present invention, as shown below. Figure 3-5 As shown: The screw 401 includes a first threaded portion 4011 and a first limiting portion 4012 that are fixedly connected. The first threaded portion 4011 is used to insert into the extension rod 30 and is threadedly connected to the extension rod 30. The diameter of the first limiting portion 4012 is larger than the diameter of the first threaded portion 4011. The end face of the first limiting portion 4012 that is connected to the first threaded portion 4011 abuts against the extension rod 30. A first slot 40121 is provided at one end of the first limiting part 4012 away from the first threaded part 4011. The first slot 40121 is used for the insertion of the first drive shaft 4021. The first slot 40121 and the first drive shaft 4021 are connected by a coupling (not shown in the figure) to transmit torque.

[0027] With this configuration, the axial movement of the extension rod 30 can be limited by the first limiting part 4012 abutting against the extension rod 30, thus preventing it from retracting excessively.

[0028] Furthermore, such as Figure 5 As shown, a second groove 301 is provided on the circumferential side wall of the extension rod 30, and a second boss 201 is provided on the inner wall of the sleeve 20; The extension rod 30 includes a first end 302 and a second end 303. The first end 302 is used to insert into the sleeve 20 and extend into the housing 10. The first end 302 is used to insert the screw 401. The second end 303 extends out of the sleeve 20 and the housing 10. The second groove 301 extends to the second end 303 of the extension rod 30. The axial length of the second boss 201 is adapted to the circumferential length of the sleeve 20. When the sleeve 20 is fitted with the extension rod 30, the second boss 201 is inserted into the second groove 301 so that the extension rod 30 is circumferentially limited and connected to the sleeve 20. When the screw 401 rotates, the extension rod 30 moves axially within the sleeve 20.

[0029] Specifically, during installation, the first end 302 of the extension rod 30 is inserted into the housing 10, and the sleeve 20 is fitted onto the second end 303 of the extension rod 30, so that the second protrusion 201 of the sleeve 20 corresponds to the second groove 301. By inserting the second protrusion 201 into the second groove 301, the sleeve 20 is pushed axially towards the first end 302 until the sleeve 20 contacts the housing 10, and then the sleeve 20 is fixedly connected to the housing 10.

[0030] With this configuration, the circumferential limiting connection between the sidewall of the second groove 301 and the sidewall of the second boss 201 is achieved through mutual abutment. As a result, when the screw 401 rotates, the extension rod 30 will not rotate with it. Through the action of the thread, the extension rod 30 slides along the second boss 201, thereby realizing the extension and retraction of the extension rod 30.

[0031] Furthermore, a second limiting part 202 is provided at one end of the sleeve 20. The diameter of the second limiting part 202 is larger than the diameter of the outer shell 10. The end of the sleeve 20 away from the second limiting part 202 is used to insert into the outer shell 10. By setting the second limiting part 202, it is possible to prevent the sleeve 20 from being overly inserted into the outer shell 10 during installation and thus being unable to be removed. At the same time, the setting of the second limiting part 202 also makes it easy to remove and disassemble it.

[0032] The sleeve 20 is threadedly connected to the outer shell 10, and the sleeve 20 is installed on the outer shell 10 by rotation. At the same time, the thread setting can realize the axial limitation of the sleeve 20 and the outer shell 10. The threads between the sleeve 20 and the outer shell 10 and between the screw 401 and the extension rod 30 have opposite directions. With this setting, when the permanent magnet 403 rotates to control the rotation of the screw 401 with the thread direction between the screw 401 and the extension rod 30, the screw 401 will give the extension rod 30 a rotational tendency in the same direction. Since the sleeve 20 and the extension rod 30 are circumferentially limited, the sleeve 20 also has a rotational tendency in the same direction. However, the sleeve 20 and the outer shell 10 have opposite directions of rotation, so the sleeve 20 cannot rotate relative to the outer shell 10. Thus, the extension rod 30 can move axially within the sleeve 20 by fixing the sleeve 20.

[0033] Furthermore, such as Figure 4 As shown, the first end 302 of the extension rod 30 extends out of the sleeve 20 and abuts against the inner wall of the housing 10. A sealing ring mounting groove 304 is provided on the circumferential side wall of the first end 302. The sealing ring mounting groove 304 is used to install a sealing ring (not shown in the figure). The sealing ring is used to make the extension rod 30 and the inner wall of the housing 10 movably seal, so as to prevent debris from entering the housing 10 along the gap between the extension rod 30 and the communication 20 when the extension rod 30 moves, and to prevent debris from blocking and affecting the axial movement of the extension rod 30.

[0034] Furthermore, Figure 6This illustration represents one embodiment of the present invention. Figure 2 Enlarged view of point C, as shown Figure 2 , 6 As shown: A first through hole 4031 is provided through the axial center of the permanent magnet 403. The second transmission shaft 4022 of the reducer 402 is inserted into the first through hole 4031 through one end of the permanent magnet 403 and is fixedly connected to the permanent magnet 403 to realize the transmission connection between the permanent magnet 403 and the reducer 402. A connecting rod 102 is provided inside the housing 10, and a second slot 103 is provided at the end of the receiving space 101 of the housing 10. The connecting rod 102 has a third end 1021 and a fourth end 1022. The third end 1021 is used to insert into the first through hole 4031 and is fixedly connected to the permanent magnet 403. The fourth end 1022 is used to insert into the second slot 103. A third slot 1031 is also provided on the second slot 103. The third slot 1031 is located between the second slot 103 and the receiving space 101. The diameter of the third slot 1031 is larger than that of the second slot 103. The third slot 1031 is used for the installation of the deep groove ball bearing 501. When the fourth end 1022 is inserted into the second slot 103, the deep groove ball bearing 501 is sleeved on the fourth end 1022. When the permanent magnet 403 rotates, the deep groove ball bearing 501 is used to bear the radial force of the connecting rod 102. Through the connecting rod 102, it further assists in supporting the permanent magnet 403, providing a fulcrum for its rotation, reducing friction with the inner wall of the outer casing 10, and improving the overall service life.

[0035] Furthermore, such as Figure 3 , 4 As shown, a third boss 40122 is provided on the circumferential sidewall of the first limiting part 4012, and a thrust ball bearing 502 is sleeved on the first limiting part 4012. The thrust ball bearing 502 is located on the side of the third boss 40122 away from the first threaded part 4011. The thrust ball bearing 502 abuts against the third boss 40122 and the reducer 402 at both axial ends to withstand the axial force of the reducer 402.

[0036] The thrust ball bearing 502 is designed to precisely distribute and bear the forces generated during the operation of the device, while reducing wear between components, ensuring transmission efficiency, and improving the service life of each component.

[0037] Meanwhile, a thrust ring 503 is also provided between the thrust ball bearing 502 and the reducer 402. The two axial ends of the thrust ring 503 abut against the thrust ball bearing 502 and the reducer 402 respectively. The thrust ring 503 is used to enhance the axial limit between the reducer 402 and the screw 401, making the structure more compact and enhancing the fixing effect between the two.

[0038] Optionally, the outer wall of the thrust ring 503 can be provided with threads, and correspondingly, the inner wall of the housing 10 can also be provided with threads. The two are connected by threads, which can further realize the axial limit of the reducer 402.

[0039] Furthermore, Figure 7 This illustration represents one embodiment of the present invention. Figure 2 Enlarged view of point D, as shown Figure 7 As shown, a threaded cap 305 is provided on the second end 303 of the extension rod 30. The second end 303 of the extension rod 30 is used to insert the threaded cap 305. A second through hole 3031 is provided on the circumferential sidewall of the extension rod 30, and a third through hole 3051 is provided on the axial sidewall of the threaded cap 305. The second through hole 3031 and the third through hole 3051 are used for the first pin (not shown in the figure) so that the threaded cap 305 is fixedly connected to the extension rod 30. The circumferential sidewall of the threaded cap 305 is provided with threads. During installation, by controlling the rotation of the outer shell 10, and by the circumferential limiting of the outer shell 10 and the sleeve 20, and the circumferential limiting of the sleeve 20 and the extension rod 30, the extension rod 30 can be rotated synchronously and further screwed into the femoral neck through the threads of the threaded cap 305, so as to realize the connection between the screw and the fixation.

[0040] Furthermore, Figure 8 This diagram illustrates the usage state of a magnetically driven force screw according to one embodiment of the present invention, as shown below. Figure 2 , 8 As shown, a fourth through hole 104 is provided on the circumferential side wall of the outer shell 10. The fourth through hole 104 is located at the end of the outer shell 10 away from the threaded cap 305. The fourth through hole 104 is used for the insertion of a bone screw (not shown in the figure). When the magnetically driven screw is implanted into the femoral neck and the outer shell 10 has been rotated or moved axially, the screw is fixed to the femoral neck by implanting the bone screw and inserting it into the fourth through hole 104 to prevent it from shaking or loosening.

[0041] Meanwhile, the magnetic drive screw of the present invention can be used alone to achieve fixation through bone screws, or it can be used in conjunction with a bone plate. A fourth slot 105 is provided at the end of the outer shell 10 away from the threaded cap 305. The fourth slot 105 is used for the insertion of the second pin 601. The second pin 601 is threadedly connected to the fourth slot 105. After the screw and femoral neck are installed, a bone plate 602 is additionally provided. The second pin 601 is inserted into the bone plate 602 and then into the fourth slot 105. A third pin 603 is additionally provided. It is inserted into the bone plate 602 and screwed into the femoral shaft and femoral neck, which can further strengthen the fixed connection between the screw and the femoral neck.

[0042] In summary, in the field of femoral neck fracture bone healing, this invention controls the extension rod 30 to extend and retract via an external magnetic field, enabling non-invasive adjustment. This solves the problem of secondary trauma to the bone caused by the need for secondary surgery in traditional techniques. Postoperative adjustment via external magnetic drive can significantly reduce postoperative recovery costs, improve surgical safety and rehabilitation efficiency, and alleviate the burden on patients.

[0043] The above description is merely a preferred embodiment of this application. Those skilled in the art should understand that the scope of disclosure in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A magnetically driven screw for femoral neck fractures, characterized in that, include: A housing for insertion into the femoral neck, the housing having a receiving space; A sleeve is disposed inside the outer casing, and the sleeve is fixedly connected to the outer casing; An extension rod is disposed inside the sleeve, and the extension rod is circumferentially limited to the sleeve, with one end of the extension rod extending out of the outer shell; A transmission assembly is disposed within the housing. The transmission assembly includes a screw, a reducer, and a permanent magnet. One end of the screw is inserted into the extension rod and threadedly connected to the extension rod. The other end of the screw is circumferentially limited and connected to the first transmission shaft of the reducer. The second transmission shaft of the reducer is fixedly connected to the permanent magnet. The permanent magnet is axially limited and connected to the housing. The permanent magnet is used to rotate circumferentially under the control of an external magnetic field, so as to drive the screw to rotate, so that the extension rod can move axially within the sleeve, thereby adjusting the tightness of the two ends of the bone at the fracture site.

2. The magnetically driven screw for femoral neck fracture according to claim 1, characterized in that, The screw includes a first threaded portion and a first limiting portion that are fixedly connected. The first threaded portion is used to be inserted into the extension rod and threadedly connected to the extension rod. The diameter of the first limiting portion is larger than the diameter of the first threaded portion. The end face of the first limiting portion connected to the first threaded portion abuts against the extension rod. A first slot is provided at the end of the first limiting portion away from the first threaded portion. The first slot is used for inserting the first drive shaft. The first slot and the first drive shaft are connected by a coupling to transmit torque.

3. The magnetically driven screw for femoral neck fracture according to claim 2, characterized in that, A second groove is provided on the circumferential sidewall of the extension rod, and a second boss is provided on the inner wall of the sleeve; The extension rod includes an axially arranged first end and a second end. The first end is used to insert into the sleeve and extend into the housing. The first end is also used for inserting the screw. The second end extends out of the sleeve and the housing. The second groove extends to the second end of the extension rod. The axial length of the second boss is adapted to the axial length of the sleeve. When the sleeve is fitted with the extension rod, the second boss is inserted into the second groove to make the extension rod circumferentially limited to the sleeve. When the screw rotates, the extension rod moves axially within the sleeve.

4. The magnetically driven screw for femoral neck fracture according to claim 1, characterized in that, A second limiting part is provided at one end of the sleeve, the diameter of the second limiting part is larger than the diameter of the outer shell, and the end of the sleeve away from the second limiting part is used to insert into the outer shell; The sleeve is threadedly connected to the outer shell to axially limit the sleeve and the outer shell. The threads between the sleeve and the outer shell and between the screw and the extension rod are opposite in direction to ensure that the sleeve and the outer shell are circumferentially limited when the screw rotates and causes the extension rod to rotate.

5. The magnetically driven screw for femoral neck fracture according to claim 1, characterized in that, The permanent magnet has a through hole at its axial center. The second drive shaft of the reducer is inserted into the first through hole through one end of the permanent magnet and is fixedly connected to the permanent magnet. A connecting rod is provided inside the housing, and a second slot is provided at the end of the receiving space inside the housing. The connecting rod has a third end and a fourth end. The third end is used to insert into the first through hole and is fixedly connected to the permanent magnet. The fourth end is used to insert into the second slot. A third slot is also provided on the second slot. The third slot is located between the second slot and the receiving space. The diameter of the third slot is larger than that of the second slot. The third slot is used for the installation of a deep groove ball bearing. When the fourth end is inserted into the second slot, the deep groove ball bearing is sleeved on the fourth end. When the permanent magnet rotates, the deep groove ball bearing is used to bear the radial force of the connecting rod.

6. The magnetically driven screw for femoral neck fracture according to claim 3, characterized in that, The first end of the extension rod extends out of the sleeve and abuts against the inner wall of the housing. A sealing ring mounting groove is provided on the circumferential side wall of the first end. The sealing ring mounting groove is used to install a sealing ring, and the sealing ring is used to make the extension rod and the inner wall of the housing movably seal.

7. The magnetically driven screw for femoral neck fracture according to claim 2, characterized in that, A third boss is provided on the circumferential sidewall of the first limiting part, and a thrust ball bearing is sleeved on the first limiting part. The thrust ball bearing is located on the side of the third boss away from the first threaded part. The thrust ball bearing abuts against the third boss and the reducer at both axial ends to withstand the axial force of the reducer.

8. The magnetically driven screw for femoral neck fracture according to claim 7, characterized in that, A thrust ring is provided between the thrust ball bearing and the reducer. The two axial ends of the thrust ring abut against the thrust ball bearing and the reducer, respectively. The thrust ring is used to enhance the axial limiting between the reducer and the screw.

9. A magnetically driven screw for femoral neck fractures according to claim 3, characterized in that, A threaded cap is provided at the second end of the extension rod, and the second end of the extension rod is used to insert the threaded cap. A second through hole is provided on the circumferential sidewall of the extension rod, and a third through hole is provided on the circumferential sidewall of the threaded cap. The second through hole and the third through hole are used to insert a first pin so that the threaded cap is fixedly connected to the extension rod. The circumferential sidewall of the threaded cap is provided with threads.

10. A magnetically driven screw for femoral neck fractures according to claim 9, characterized in that, A fourth through hole is provided on the circumferential sidewall of the outer shell. The fourth through hole is located at the end of the outer shell away from the threaded cap. The fourth through hole is used for the insertion of a bone screw to restrict the movement of the outer shell.

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