Integrated magnetically driven bidirectional intramedullary nail

Abstract

The embodiment of the application provides a one-piece magnetic driving bidirectional intramedullary nail, and belongs to the technical field of orthopedic implant medical instruments. The bidirectional intramedullary nail comprises a sleeve, a one-piece pipe section with a through hole; a telescopic unit composed of a magnetic driving part, a speed reduction part, an extension part and a bushing which are sequentially connected in the sleeve, and the telescopic unit comprises a first telescopic unit and a second telescopic unit which are symmetrically arranged in the sleeve along the axial direction of the middle plane; a limiting part arranged on the inner wall of the sleeve, at least three limiting parts are arranged on the first telescopic unit and the second telescopic unit respectively, and the limiting parts are used for limiting the positions of the magnetic driving part, the speed reduction part and the extension part in the axial direction; the part of the bushing in the sleeve limits the position of the extension part in the circumferential direction through a key groove structure, and the part of the bushing outside the sleeve is fixedly arranged together with the end part of the sleeve to form a terminal limiting part. The bidirectional intramedullary nail can realize bidirectional extension or contraction of two ends under variable load to complete various bone reconstruction processes.

Description

Technical Field

[0001] This invention relates to the technical field of orthopedic implantable medical devices, and in particular to an integrated magnetically driven bidirectional intramedullary nail. Background Technology

[0002] Limb lengthening, bone healing, and bone reconstruction surgeries are commonly used for the treatment and rehabilitation of conditions such as limb length discrepancy, pathological short stature, nonunion, and bone defects. These procedures involve a long treatment and rehabilitation period, requiring patients to wear traction devices for an extended period to provide space for bone growth.

[0003] Currently, treatment primarily employs fixed or adjustable external fixation metal braces, whose main structure is located outside the patient's body, forming a three-dimensional frame around the fracture site. This maintains the stability and position of the fracture site while allowing for controlled traction. However, these brace structures have several drawbacks. For example, the brace requires radial drilling through the skin around the fracture site and long-term fixation, posing a very high risk of infection during the patient's treatment and rehabilitation period, potentially leading to complications such as knee flexion contractures. Furthermore, the wearing process can interfere with surrounding nerves and soft tissues. Additionally, patient comfort during treatment and rehabilitation is poor, and nursing care is challenging.

[0004] Improved internal fixation limb reconstruction devices (existing intramedullary nails) generally use magnetic drive. Although they effectively improve patient comfort and reduce infection risk during treatment and rehabilitation compared to external fixation devices, these intramedullary nails have problems such as easy structural breakage, difficulty in disinfection, and insufficient driving force due to structural strength limitations.

[0005] In view of this, there is a need to propose a novel integrated magnetically driven bidirectional intramedullary nail to solve all or part of the above problems. Summary of the Invention

[0006] To address at least one of the aforementioned problems and deficiencies in the prior art, embodiments of the present invention provide an integrated magnetically driven bidirectional intramedullary nail. By symmetrically arranging two sets of magnetically driven telescopic units within the sleeve of the bidirectional intramedullary nail along its central plane and by correspondingly providing multi-level limiting portions on the inner wall of the sleeve, simultaneous bidirectional lengthening or contraction at both ends under external magnetic field excitation is achieved to complete the bone lengthening and bone transport treatment process. The technical solution is as follows:

[0007] According to one aspect of the present invention, an integrated magnetically driven bidirectional intramedullary nail is provided. The bidirectional intramedullary nail comprises:

[0008] A sleeve is a one-piece pipe section with a through hole;

[0009] The telescopic unit consists of a magnetic drive section, a deceleration section, an extension section and a bushing connected in sequence inside the sleeve. The telescopic unit includes a first telescopic unit and a second telescopic unit symmetrically arranged inside the sleeve along the central plane in the axial direction.

[0010] A limiting part is provided on the inner wall of the sleeve. At least three levels of limiting parts are respectively provided in the first telescopic unit and the second telescopic unit. The at least three levels of limiting parts are used to limit the position of the magnetic drive part, the deceleration part and the extension part in the axial direction.

[0011] The portion of the bushing located inside the sleeve defines the circumferential position of the extension by a keyway structure, while the portion located outside the sleeve is fixedly mounted together with the end of the sleeve to form an end limiting portion.

[0012] In some embodiments, preferably, the deceleration section of the first telescopic unit is set to a first preset deceleration ratio by means of a decelerator, and the deceleration section of the second telescopic unit is set to a second preset deceleration ratio by means of a decelerator, wherein the ratio of the first preset deceleration ratio to the second preset deceleration ratio is different.

[0013] In some embodiments, preferably, the first maximum extension length of the extension portion of the first telescopic unit is different from the second maximum extension length of the extension portion of the second telescopic unit; when the extension portion of the first telescopic unit extends, the extension portion of the second telescopic unit compresses, or when the extension portion of the first telescopic unit compresses, the extension portion of the second telescopic unit extends.

[0014] In some embodiments, specifically within the telescopic unit, the magnetic drive section includes an integrally assembled magnetic drive bearing assembly and a magnetic drive rotating shaft. The reduction section includes an integrally assembled reducer bearing assembly, an output shaft, and a reducer housing. The extension section includes an integrally assembled lead screw bearing assembly, a lead screw, and an extension rod. The output end of the magnetic drive section is connected to the input end of the reduction section, and the output end of the reduction section is connected to the extension section, pushing or pulling the extension section axially under the action of magnetic drive force.

[0015] In some embodiments, alternatively, the first telescopic unit and the second telescopic unit share the same magnetic drive part, which outputs different magnetic drive forces to drive the extension parts of the first telescopic unit and the extension parts of the second telescopic unit to extend and retract.

[0016] In some embodiments, alternatively, a first magnetic drive unit is provided in the first telescopic unit to drive the extension of the first telescopic unit to extend and retract, while a second magnetic drive unit is provided in the second telescopic unit to drive the extension of the second telescopic unit to extend and retract.

[0017] In some embodiments, specifically, the bushing of the telescopic unit is inserted into the sleeve from the end of the sleeve and fitted onto the outside of the extension. A limiting flange is provided at one end of the bushing that is located outside the sleeve, and at least one sealing ring is fitted onto the outer side of the bushing near the limiting flange. When the bushing is assembled into the sleeve, the limiting flange abuts against and is fixed to the end of the sleeve, and the interior of the bidirectional intramedullary nail is completely sealed by the at least one sealing ring.

[0018] In some embodiments, specifically, at least three levels of limiting portions are provided, which sequentially include a first limiting portion, a second limiting portion, and a third limiting portion along the middle to the end of the sleeve. The first limiting portion is located on the side of the magnetic drive unit away from its output end, and limits its axial position when the magnetic drive unit is assembled into the sleeve. The second limiting portion is located on the side of the input end of the deceleration unit, and limits its axial position when the deceleration unit is assembled into the sleeve. The third limiting portion is located on the side of the input end of the extension unit, and limits its axial position when the extension unit is assembled into the sleeve.

[0019] In some embodiments, preferably, one end of the bushing disposed inside the sleeve abuts against the third limiting portion to define the axial position of the lead screw bearing assembly of the extension.

[0020] In some embodiments, the bidirectional intramedullary nail further includes at least one first end screw-in hole, at least one second end screw-in hole, and at least one central screw-in hole. The first end screw-in hole is located at the end of the output end of the extension of the first telescopic unit and is used to fix a bone segment at one end by screwing. The second end screw-in hole is located at the end of the output end of the extension of the second telescopic unit and is used to fix a bone segment at the other end by screwing. The central screw-in hole is located in the middle of the sleeve and is used to fix a bone segment in the middle by screwing.

[0021] In some embodiments, preferably, the bidirectional intramedullary nail further includes a locking screw for fixing the bone segment, the locking screw comprising a front self-tapping head, a middle smooth post, and a rear threaded post connected in sequence. The front self-tapping head has a tapered guide structure with self-tapping threads on its surface. The diameter of the middle smooth post is equal to the maximum outer diameter of the front self-tapping head. The rear threaded post includes a first thread located near the middle smooth post and a second thread located at the rear end of the first thread, the pitch of the first thread being smaller than the pitch of the second thread.

[0022] The integrated magnetically driven bidirectional intramedullary nail provided by the embodiments of the present invention has at least one or a portion of the following advantages:

[0023] (1) By symmetrically setting two sets of telescopic units along the central plane in the sleeve, the proximal and distal ends can be lengthened or contracted simultaneously under the excitation of an external magnetic field, so as to realize the bone lengthening and bone transport treatment process in the medullary cavity.

[0024] (2) Through the integrated design of the sleeve and two telescopic units, the bidirectional intramedullary nail can be completely placed inside the medullary cavity without open wounds or other auxiliary structures, effectively avoiding soft tissue irritation and wound infection during treatment.

[0025] (3) By setting two independent telescopic units in the sleeve, differentiated treatment operations can be performed on the proximal and distal bones respectively, such as different telescopic processes, telescopic speeds, and screw rotation directions for the proximal and distal bones.

[0026] (4) By setting multi-level limiting parts on the inner wall of the sleeve of the bidirectional intramedullary nail, the integrated magnetic drive part, deceleration part, extension part and bushing can be automatically limited one by one when they are installed into the sleeve. This can effectively and evenly distribute the load generated during the operation of the bidirectional intramedullary nail, avoid stress concentration, help to further improve the magnetic drive output power, and make it suitable for more orthopedic treatment and rehabilitation scenarios by adjusting the external magnetic field.

[0027] (5) The multi-stage limiting part in the sleeve, combined with the end limiting of the bushing, can effectively improve the overall structural rigidity and fatigue strength of the bidirectional intramedullary nail, and prevent deformation or breakage caused by long-term use.

[0028] (6) By extending the length of the bushing so that it can abut against the limiting part used to limit the extension part when it is inserted into the sleeve, it can provide support for the sleeve after most of the extension part extends out of the sleeve, thereby improving the stiffness of the sleeve and preventing breakage.

[0029] (7) By setting matching keyway structures on the inner wall of the bushing and the outer wall of the extension, the position of the extension in the circumferential direction can be locked to prevent the extension from rotating in the circumferential direction when the bidirectional intramedullary nail is working. At the same time, the limiting eaves and sealing ring at the bottom of the bushing can be used to seal the bidirectional intramedullary nail as a whole.

[0030] (8) The assembly convenience of intramedullary nails can be improved by the multi-level limiting part in the sleeve. At the same time, the specific structure of the multi-level limiting part can be customized to match the specific structure of the two telescopic units. Various types of bidirectional intramedullary nail structures are commonly used. Attached Figure Description

[0031] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:

[0032] Figure 1This is a schematic diagram of the structure of a bidirectional intramedullary nail according to an embodiment of the present invention;

[0033] Figure 2 for Figure 1 A cross-sectional view of one internal structure of a bidirectional intramedullary nail is shown.

[0034] Figure 3 for Figure 1 A cross-sectional view of another internal structure of the bidirectional intramedullary nail is shown.

[0035] Figure 4 for Figure 1 and Figure 3 The diagram shows a structural schematic of a telescopic unit of a bidirectional intramedullary nail.

[0036] Figure 5 This is a schematic diagram of the structure of the bushing of a bidirectional intramedullary nail according to an embodiment of the present invention;

[0037] Figures 6a-6d Schematic diagrams illustrating the intraosseous implantation status of bidirectional intramedullary nails in different scenarios;

[0038] Figure 7 This is a schematic diagram of the locking screw structure of one embodiment of a bidirectional intramedullary nail. Detailed Implementation

[0039] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof.

[0040] It should also be understood that although the terms "first," "second," "third," etc., may be used in the following embodiments of the present invention to describe a component comprising two or more of the same component, these components should not be limited to these terms, which are only used to distinguish each component from one another. Furthermore, descriptions indicating orientation such as "upper," "lower," "left," "right," "top," and "bottom" are merely illustrative of the relative positions of components and should not be construed as a limitation of the present invention.

[0041] The present invention provides an integrated magnetically driven bidirectional intramedullary nail. By symmetrically arranging two sets of magnetically driven telescopic units in the central plane within the integrated sleeve of the bidirectional intramedullary nail and by setting multi-level limiting parts on the inner wall of the sleeve, it is possible to simultaneously extend or contract both ends in both directions under the excitation of an external magnetic field to complete various treatment processes such as bone lengthening and bone transport.

[0042] See Figure 1The diagram illustrates the product structure of a bidirectional intramedullary nail 100 according to one embodiment. Figure 2 and Figure 3 Two specific internal structures of the bidirectional intramedullary nail according to the present invention are shown respectively.

[0043] Combination Figures 1-3 As shown, the bidirectional intramedullary nail 100 mainly consists of an external, integral sleeve 10 and two independently operating telescopic units 20 (a first telescopic unit 21 and a second telescopic unit 22). Specifically, the sleeve 10 is an integral tube segment with a through hole for accommodating the telescopic units 20. The telescopic units 20 include a first telescopic unit 21 and a second telescopic unit 22 symmetrically arranged inside the sleeve 10 along the central plane of the bidirectional intramedullary nail 100 in the axial direction. Figure 3 Taking the first telescopic unit 21 on one side of the internal structure shown as an example, it consists of a magnetic drive part 211, a deceleration part 212, an extension part 213 and a bushing 214 connected in sequence inside the sleeve 10.

[0044] Furthermore, a multi-stage limiting part is also provided on the inner wall of the sleeve 10 (see details). Figure 4 As described below, at least three levels of limiting portions are respectively provided in the first telescopic unit 21 and the second telescopic unit 22. These at least three levels of limiting portions are used to respectively limit the axial positions of the corresponding magnetic drive portion 211, deceleration portion 212 and extension portion 213 of the first telescopic unit 21. Similarly, the second telescopic unit 22 is also provided in a similar manner.

[0045] Furthermore, the portion of the bushing (e.g., bushing 214 of the first telescopic unit 21) located inside the sleeve 10 is connected via a keyway structure (see details). Figure 5 The specific structure of the bushing 214 defines the extension (e.g., the extension 213 of the first telescopic unit 21) in a circumferential position, and the portion of the extension located outside the sleeve 10 is fixedly disposed together with the end of the sleeve 10 to form an end limiting portion.

[0046] The bidirectional intramedullary nail 100 described above has two sets of symmetrical and independently operating telescopic units 20, allowing each telescopic unit 20 to perform bone traction treatment in its respective direction. Furthermore, by using an external magnetic field generator and adjusting the magnetic field parameters, differentiated operation of the two telescopic units can be achieved.

[0047] In one example, preferably, the deceleration section 212 of the first telescopic unit 21 adjusts and sets a first preset deceleration ratio through its internal reducer. Simultaneously, the deceleration section 222 of the second telescopic unit 22 adjusts and sets a second preset deceleration ratio through its internal reducer. When the ratio of the first preset deceleration ratio to the second preset deceleration ratio is different, differentiated drive outputs can be achieved for the two telescopic units, providing drive loads with different telescopic speeds.

[0048] In one example, preferably, the first maximum extension length of the extension portion 213 of the first telescopic unit 21 (e.g., the maximum extendable length that the lead screw inside the extension portion 213 can push the extension rod from the initial position to the farthest extension position by a threaded connection) is different from the second maximum extension length of the extension portion 223 of the second telescopic unit 22, thereby achieving differentiated output of extension length.

[0049] For example, the extension lengths of the two different extension portions 213 and 223 at both ends can be adjusted by setting specific mating structures, such as the lead screw thread and the extension push rod. For example, the extension length can be adjusted by designing different thread lengths or pitches on the lead screw threads.

[0050] In one example, preferably, when the extension portion 213 of the first telescopic unit 21 extends, the extension portion 223 of the second telescopic unit 22 compresses, or when the extension portion 213 of the first telescopic unit 21 compresses, the extension portion 223 of the second telescopic unit 22 extends, thereby achieving differentiated output of stretching action on the skeleton.

[0051] For example, the opposite extension and retraction directions can also be achieved by adjusting the screw thread direction in different extensions 213 and 223 respectively.

[0052] The above-described differentiated drawing structures are merely illustrative examples and should not be construed as a limitation of the present invention by those skilled in the art.

[0053] In one example, such as Figure 2 The bidirectional intramedullary nail 100a shown can alternatively have the first telescopic unit 21 and the second telescopic unit 22 share the same magnetic drive section 221a, which outputs different magnetic drive forces to drive the extension section 213 of the first telescopic unit 21 and the extension section 223 of the second telescopic unit 22 to extend and retract.

[0054] In one example, such as Figure 3The bidirectional intramedullary nail 100b shown can alternatively have a first magnetic drive unit (i.e., magnetic drive unit 211) provided in the first telescopic unit 21 to drive the extension 213 of the first telescopic unit 21 to telescopically extend and retract, and a second magnetic drive unit 221b provided in the second telescopic unit 22 to drive the extension 223 of the second telescopic unit 22 to telescopically extend and retract.

[0055] See Figure 4 The diagram shows the specific structure of the telescopic unit 20 inside the sleeve 10 in one embodiment (the first telescopic unit 21 is taken as an example, and the second telescopic unit 22 is similarly and symmetrically arranged with respect to the first telescopic unit 21).

[0056] In one example, specifically, combining Figure 3 and Figure 4 As shown, the magnetic drive unit 211 of the first telescopic unit 21 includes an integrally assembled magnetic drive rotating shaft 2111 and a magnetic drive bearing assembly 2112. The deceleration unit 212 includes an integrally assembled reducer bearing assembly, an output shaft, and a reducer housing (not shown). The extension unit 213 includes an integrally assembled lead screw 2131, an extension rod 2132, and a lead screw bearing assembly 2133. The output end of the magnetic drive unit 211 is connected to the input end of the deceleration unit 212, and the output end of the deceleration unit 212 is connected to the extension unit 213, pushing or pulling the extension unit 213 axially under the action of magnetic drive force.

[0057] Similarly, in the second telescopic unit 22, the extension section 223 includes an integrally assembled lead screw 2231, extension rod 2232, and lead screw bearing assembly 2233. The output end of the magnetic drive section 221b is connected to the input end of the deceleration section 222, and the output end of the deceleration section 222 is connected to the extension section 223, pushing or pulling the extension section 223 axially under the action of magnetic drive force.

[0058] After the bidirectional intramedullary nail 100 (the same applies to bidirectional intramedullary nail 100a and bidirectional intramedullary nail 100b) is implanted into the bone, the extensions 213 and 223 extending from both ends of the sleeve 10 can be extended axially for bone lengthening, bone traction and other treatment and rehabilitation operations, or compressed for bone connection, bone closure and other treatment and rehabilitation operations.

[0059] For example, such as Figure 4 As shown, the fixed assembly method of the magnetic drive bearing assembly 2112 and the magnetic drive rotating shaft 2111 in the magnetic drive unit 211 can be selected and assembled according to the existing accessory design. Figure 4 Three exemplary designs (a, b, and c) for the magnetic drive unit 211 are given. The magnetic drive rotation shaft 2111 can be designed as a single, through-structure component. It can also be a separate design. Alternatively, it can be a wraparound design fixed to the housing of the magnetic drive unit 211. Furthermore, during assembly, the end of the magnetic drive unit 211 furthest from the output end ( Figure 4 The uppermost part is limited and fixed by the limiting part (first limiting part 11).

[0060] Alternatively, a limiting shoulder structure 2113 can be added to the magnetic drive unit 211. This limiting shoulder structure 2113 can be integrated with the magnetic drive bearing assembly 2112 and / or the magnetic drive rotating shaft 2111. A structure such as an elastic retaining ring can also be used as the limiting shoulder structure 2113. The limiting shoulder structure 2113 can effectively ensure that there is no relative displacement between the internal components of the magnetic drive unit 211, reducing energy transfer losses.

[0061] For example, the reducer housing of the reduction unit 212 contacts the inner wall of the sleeve 10 and is limited and fixed by a limiting part (second limiting part 12) inside the sleeve 10. The output shaft of the reduction unit 212 is fixedly connected to the lead screw 2131 of the extension unit 213. For example, the output shaft of the reduction unit 212 and the lead screw 2131 of the extension unit 213 are integrally machined, which helps the reduction unit 212 to directly drive the lead screw 2131 to rotate to push or pull back the extension rod 2132 that cooperates with the lead screw 2131.

[0062] For example, other connection and transmission methods may also be used between the deceleration part 212 and the extension part 213, such as interference fit, welding or threaded fit.

[0063] For example, the reduction unit 212 can significantly increase the transmitted torque while transmitting the torque from the magnetic drive unit 211. For example, a multi-stage planetary gear reducer can be used to increase the transmitted torque; preferably, at least three planetary gears are connected in series.

[0064] For example, the lead screw bearing assembly 2133 of the extension 213 can also be configured to cooperate with the lead screw shoulder structure (not shown) and abut against and limit the third limiting part 13 inside the sleeve 10. The outer surface of the lead screw 2131 and the inner surface of the extension rod 2132 are connected by a coupling thread (not shown) to form a lead screw-nut motion attachment, which causes the rotational motion of the lead screw 2131 to drive the extension rod 2132 to produce axial linear motion relative to the sleeve 10.

[0065] For example, a sealing cavity may be provided on the extension rod 2132, and a silicone rubber sealing material is assembled in the sealing cavity to ensure the sealing of the internal parts of the cavity.

[0066] For example, the coupling thread between the lead screw 2131 and the extension rod 2132 may use lubricating oil to reduce friction, or the coupling thread may be made of a material with a low coefficient of friction to reduce friction.

[0067] The above-described specific structural configurations of the magnetic drive section, deceleration section, and extension section connected in series inside the telescopic unit 20 are merely illustrative examples. Those skilled in the art can make adaptive designs according to the actual structural and functional requirements of the intramedullary nail, and should not be construed as a limitation of the present invention.

[0068] In one example, specifically, such as Figure 4 As shown, at least three levels of limiting portions are provided, which sequentially include a first limiting portion 11, a second limiting portion 12, and a third limiting portion 13 along the middle to the end of the sleeve 10. The first limiting portion 11 is located on the side of the magnetic drive portion 211 away from its output end, and when the magnetic drive portion 211 is assembled and enters the sleeve 10, the first limiting portion 11 limits its axial position. The second limiting portion 12 is located on the side of the input end of the deceleration portion 212, and when the deceleration portion 212 is assembled and enters the sleeve 10, the second limiting portion 12 limits its axial position. The third limiting portion 13 is located on the side of the input end of the extension portion 213, and when the extension portion 213 is assembled and enters the sleeve 10, the third limiting portion 13 limits its axial position.

[0069] In one example, preferably, the first limiting part 11, the second limiting part 12 and the third limiting part 13 are boss structures provided on the inner wall of the sleeve 10 and protruding towards the axis.

[0070] For example, a boss structure is provided on the inner wall of the sleeve 10. Its specific position, number, and shape can be matched and adjusted according to the specific external shape and dimensions of the magnetic drive unit 211, the deceleration unit 212, and the extension unit 213. In the assembly process of existing intramedullary nails, due to the large number of internal assembly components, minor axial assembly position errors often occur at the connection points of internally connected parts, leading to error accumulation and overall structural failure. Therefore, the design of multi-level limiting parts can effectively avoid error accumulation and stress concentration.

[0071] For example, when multiple sets of thrust bearings or rolling bearings are connected in series inside, for example, the magnetic drive section 211 or the extension section 213, the number of corresponding limiting portions can be increased on the inner wall of the sleeve 10 to match the positions of these bearing sets. For example Figure 4 The example shows the specific configuration of three different bearing mating structures, A, B and C, at the input end of the extension 213. Correspondingly, the third limiting part 13 used to limit its axial position can also have different numbers or different fitting shapes.

[0072] For example, when the shape of the deceleration part 212 has a non-smooth cylindrical surface design, the shape of the boss structure of the corresponding second limiting part 12 needs to be changed. For example, a circumferential non-uniform thickness design, such as a hexagonal or quadrilateral cross-sectional shape, can be adopted to match the actual shape of the deceleration part 212.

[0073] See Figure 5 The diagram illustrates the specific structure of a bushing for a bidirectional intramedullary nail 100 in one embodiment.

[0074] In one example, specifically taking the first telescopic unit 21 in the telescopic unit 20 as an example, the bushing 214 of the first telescopic unit 21 is inserted from the end of the sleeve 10, disposed inside the sleeve 10, and sleeved on the outside of the extension 213.

[0075] In one example, the bushing 214 is further provided with a limiting eave 2141 at one end outside the sleeve 10, and at least one sealing ring 2142 is provided on the outer side of the bushing 214 near the limiting eave 2141. When the bushing 214 is installed into the sleeve 10, the limiting eave 2141 abuts against and is fixed to the end of the sleeve 10, and the interior of the bidirectional intramedullary nail 100 is sealed as a whole by the at least one sealing ring 2142.

[0076] In one example, preferably, a limiting key 2143 is provided on the inner wall of the bushing 214, and a limiting groove (not shown) is provided on the surface of the extension rod 2132 of the extension portion 213 to cooperate with the limiting key 2143. This can effectively limit the circumferential movement of the extension rod 2132 and prevent the circumferential rotation of the extension rod 2132 during the operation of the bidirectional intramedullary nail 100.

[0077] With the above configuration, the structure of bushing 214 can effectively reduce the risk of breakage at the thinnest part of sleeve 10, that is, fill the axial portion of the cavity left by extension rod 2132 after it extends out of sleeve 10.

[0078] In one example, preferably, one end of the bushing 214 disposed inside the sleeve 10 abuts against the third limiting portion 13 to define the axial position of the lead screw bearing assembly 2133 of the extension portion 213.

[0079] For example, the specific structure of the limiting flange 2141 at the end of the bushing 214 exposed above the sleeve 10 can be varied. For example, a boss-shaped structure with a groove, or a flange structure with a spring, etc.

[0080] For example, the limiting flange 2141 of the bushing 214 can also adopt an interference fit, a locking fit, or a toothed structure, which can further prevent the bushing 214 from being dislodged by the movement of the extension rod 2132.

[0081] For example, after the bushing 214 is inserted into the sleeve 10, it fits tightly against the inner wall of the sleeve 10. By cooperating with the third limiting part 13 on the inner wall of the sleeve 10, the axial assembly position of the lead screw bearing assembly 2133 of the extension part 213 can be further defined.

[0082] The aforementioned integrated bidirectional intramedullary nail 100 has been experimentally verified to effectively average the workload and provide bidirectional differentiated traction, thereby further increasing the magnetic drive load and enabling its application in more treatment scenarios. For example, during load compression, the multi-level axial limiting fixation prevents slippage of the core transmission components due to increased load. Furthermore, the bidirectional differentiated traction can be used in various bone treatment procedures.

[0083] by Figure 3 Taking two sets of telescopic units 20 arranged in a completely symmetrical manner as an example, after the magnetic drive part, deceleration part, extension part and bushing are connected in series on both sides, the whole unit is placed into the inside of the sleeve 10 and can be automatically limited by the corresponding multi-level limiting parts and the bushings at both ends to complete the assembly.

[0084] The multi-stage limiting mechanism is a complementary design, working in conjunction with core transmission components such as bushings, bearing structures in the magnetic drive section, and reducers in the reduction section. On one hand, it improves the ease of assembly of the bidirectional intramedullary nail 100, thereby enhancing assembly accuracy and limiting reliability. On the other hand, it effectively distributes the working load, avoiding stress concentration and improving the overall rigidity of the bidirectional intramedullary nail 100. It also facilitates a low-cost sterilization process.

[0085] The bushings are located at both ends of the sleeve 10. On the one hand, they can provide structural sealing, and on the other hand, they provide end positioning for the assembly of the internal core transmission components of the bidirectional intramedullary nail 100, thus forming the final stage end limiting part.

[0086] See Figures 6a-6d The images illustrate different structures and states in which the bidirectional intramedullary nail 100 is implanted into the bone. Because the bidirectional intramedullary nail 100 has the function of simultaneously and differentially tractioning the bone in both directions, it can be used in, for example... Figure 6a The scenario of traction bone healing between the upper and lower bone segments can also be used in, for example... Figures 6b-6d A scene depicting the traction and healing of the upper, middle, and lower segments of the skeleton.

[0087] In one example, specifically, the bidirectional intramedullary nail 100 further includes at least one first end nailing through hole 2134, at least one second end nailing through hole 2234, and at least one middle nailing hole 14.

[0088] The first end screw-in hole 2134 is located at the end of the output end of the extension 213 of the first telescopic unit 21, for fixing a bone segment at one end by screwing. The number of first end screw-in holes 2134 can be set according to the requirements of bone treatment, for example, one, two or more. Similarly, the second end screw-in hole 2234 is located at the end of the output end of the extension 223 of the second telescopic unit 22, for fixing a bone segment at the other end by screwing. For example, in... Figures 6a-6c Two through holes are provided at each of the two ends.

[0089] A central screw-in hole 14 is located in the middle of the sleeve 10 for fixing the central bone segment by screwing. The number of central screw-in holes 14 can be set according to the requirements of bone treatment, such as one, two, or more. For example, in... Figure 6b , Figure 6d A through hole was set in it. Figure 6c Two recessed positioning holes for fixing screws are provided in the middle. The screw hole 14 in the middle is mainly used for transporting the middle bone segment during bone transport surgery.

[0090] For example, in order to adapt to the inclined structure of the bone segments at both ends, especially the structure of the upper bone segment, a nailing sleeve 15 can be fitted onto the protruding end of the upper extension (the extension 223 of the second telescopic unit 22) to fit the structural direction of the upper bone segment and to cooperate in setting an inclined nailing through hole to facilitate the stable fixation of the upper bone segment.

[0091] See Figure 7 The diagram illustrates the specific structure of a locking screw 200 that mates with a first end nailing through-hole 2134, a second end nailing through-hole 2234, and a middle nailing hole 14 on a bidirectional intramedullary nail 100.

[0092] The locking screw 200 serves two main functions. First, it provides transverse fixation (perpendicular to the axial direction of the bidirectional intramedullary nail 100) to inhibit rotational displacement between the intramedullary nail 100 and the bone, enhancing the overall stability of the implanted structure. Second, it applies pressure fixation to fracture fragments, creating temporary mechanical support in the fracture area and fostering a favorable mechanical environment for callus formation. In clinical applications, the locking screw 200 functions both as an anti-rotation device to limit abnormal movement of the bidirectional intramedullary nail 100 and as a fixation device for bone fragments, similar to a bone screw.

[0093] In one example, preferably, the locking pin 200 includes a front self-tapping head 210, a middle smooth post 220, and a rear threaded post 230 connected in sequence. The front self-tapping head 210 has a tapered guide structure with self-tapping threads on its surface. The diameter of the middle smooth post 220 is equal to the maximum outer diameter of the front self-tapping head 210. The rear threaded post 230 includes a first thread 231 located near the middle smooth post 220 and a second thread 232 located at the rear end of the first thread 231, wherein the pitch of the first thread 231 is smaller than the pitch of the second thread 232.

[0094] For example, the pitch of the self-tapping thread of the front-end self-tapping head 210 is preferably 0.8-1.2 mm, and the depth of the self-tapping thread is preferably 0.3-0.5 mm; the radius of the rounded corner of the self-tapping thread is 0.2-0.5 mm. The front-end self-tapping head 210 can automatically tap into the bone during implantation without pre-drilling, which helps to improve surgical precision and efficiency.

[0095] For example, the length of the intermediate smooth post 220 is 1-3 mm longer than the length of the central nailing hole 14 of the bidirectional intramedullary nail 100, and the outer diameter of the intermediate smooth post 220 is 0.05-0.15 mm smaller than the diameter of the central nailing hole 14. The surface of the intermediate smooth post 220 is smooth and without threads, which facilitates its smooth passage through the central nailing hole 14 of the bidirectional intramedullary nail 100 during implantation, achieving initial positioning.

[0096] For example, the connection between the front self-tapping head 210 and the middle smooth post 220 is also provided with a rounded corner, which can reduce stress concentration and prevent the locking pin 200 from breaking at this point.

[0097] For example, on the surface of the end threaded post 230, the first thread 231 is a close-pitch thread, preferably with a pitch of 0.5-0.8 mm. The second thread 232 is a wide-pitch thread, preferably with a pitch of 1.0-1.5 mm. The head of the locking pin 200 ( Figure 7 The right end of the screw also features an internal hexagonal countersunk hole and an anti-dislodgement device. The close-pitch thread engages tightly with cortical bone, providing reliable fixation. Simultaneously, the sparse-pitch thread is suitable for cancellous bone fixation. This dual-segment thread structure design better adapts to different bone types, enhancing the overall stability of the locking screw 200 and the bidirectional intramedullary nail 100.

[0098] The integrated magnetically driven bidirectional intramedullary nail provided by the embodiments of the present invention has at least one or a portion of the following advantages:

[0099] (1) By symmetrically setting two sets of telescopic units along the central plane in the sleeve, the proximal and distal ends can be lengthened or contracted simultaneously under the excitation of an external magnetic field, so as to realize the bone lengthening and bone transport treatment process in the medullary cavity.

[0100] (2) Through the integrated design of the sleeve and two telescopic units, the bidirectional intramedullary nail can be completely placed inside the medullary cavity without open wounds or other auxiliary structures, effectively avoiding soft tissue irritation and wound infection during treatment.

[0101] (3) By setting two independent telescopic units in the sleeve, differentiated treatment operations can be performed on the proximal and distal bones respectively, such as different telescopic processes, telescopic speeds, and screw rotation directions for the proximal and distal bones.

[0102] (4) By setting multi-level limiting parts on the inner wall of the sleeve of the bidirectional intramedullary nail, the integrated magnetic drive part, deceleration part, extension part and bushing can be automatically limited one by one when they are installed into the sleeve. This can effectively and evenly distribute the load generated during the operation of the bidirectional intramedullary nail, avoid stress concentration, help to further improve the magnetic drive output power, and make it suitable for more orthopedic treatment and rehabilitation scenarios by adjusting the external magnetic field.

[0103] (5) The multi-stage limiting part in the sleeve, together with the end limiting of the bushing, can effectively improve the overall structural rigidity and fatigue strength of the bidirectional intramedullary nail, and prevent deformation or breakage caused by long-term use.

[0104] (6) By extending the length of the bushing so that it can abut against the limiting part used to limit the extension part when it is inserted into the sleeve, it can provide support for the sleeve after most of the extension part extends out of the sleeve, thereby improving the stiffness of the sleeve and preventing breakage.

[0105] (7) By setting matching keyway structures on the inner wall of the bushing and the outer wall of the extension, the position of the extension in the circumferential direction can be locked to prevent the extension from rotating in the circumferential direction when the bidirectional intramedullary nail is working. At the same time, the limiting eaves and sealing ring at the bottom of the bushing can be used to seal the bidirectional intramedullary nail as a whole.

[0106] (8) The assembly convenience of intramedullary nails can be improved by the multi-level limiting part in the sleeve. At the same time, the specific structure of the multi-level limiting part can be customized to match the specific structure of the two telescopic units. Various types of bidirectional intramedullary nail structures are commonly used.

[0107] While some embodiments of the present general inventive concept have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. A one-piece magnetically driven bidirectional intramedullary nail, characterized in that, The bidirectional intramedullary nail includes: Sleeve, wherein the sleeve is an integral pipe section with a through hole; The telescopic unit includes a first telescopic unit and a second telescopic unit that are independently operated and symmetrically arranged inside the sleeve along the central plane in the axial direction. Each of the first telescopic unit and the second telescopic unit independently includes a magnetic drive part, a deceleration part, an extension part and a bushing that are sequentially connected in series inside the sleeve. The limiting part is disposed on the inner wall of the sleeve. At least three levels of limiting parts are respectively provided at the installation positions of the first telescopic unit and the second telescopic unit. The at least three levels of limiting parts are used to limit the axial positions of the corresponding magnetic drive part, the deceleration part and the extension part and to uniformly distribute the load generated during the operation of the bidirectional intramedullary nail. The portion of the bushing located inside the sleeve defines the circumferential position of the extension by a keyway structure, while the portion located outside the sleeve is fixedly disposed together with the end of the sleeve to form an end limiting portion.

2. The bidirectional intramedullary nail according to claim 1, characterized in that, The deceleration section of the first telescopic unit is adjusted to set a first preset deceleration ratio via a reducer. The deceleration section of the second telescopic unit is adjusted to a second preset deceleration ratio via a reducer. The ratio of the first preset reduction ratio to the second preset reduction ratio is different.

3. The bidirectional intramedullary nail according to claim 2, characterized in that, The first maximum extension length of the extension portion of the first telescopic unit is different from the second maximum extension length of the extension portion of the second telescopic unit; When the extension portion of the first telescopic unit extends, the extension portion of the second telescopic unit compresses, or When the extension of the first telescopic unit is compressed, the extension of the second telescopic unit is extended.

4. The bidirectional intramedullary nail according to any one of claims 1-3, characterized in that, Inside the telescopic unit, The magnetic drive unit includes an integrally assembled magnetic drive bearing assembly and a magnetic drive rotating shaft. The reduction unit includes an integrally assembled reducer bearing assembly, output shaft, and reducer housing; The extension includes an integrally assembled lead screw bearing assembly, lead screw, and extension rod; The output end of the magnetic drive unit is connected to the input end of the deceleration unit, and the output end of the deceleration unit is connected to the extension unit. Under the action of magnetic drive force, the extension unit is pushed or pulled back along the axial direction.

5. The bidirectional intramedullary nail according to claim 4, characterized in that, The first telescopic unit and the second telescopic unit share the same magnetic drive unit. This same magnetic drive unit outputs different magnetic drive forces to drive the extensions of the first telescopic unit and the second telescopic unit to extend and retract, respectively. A first magnetic drive unit is provided in the first telescopic unit to drive the extension of the first telescopic unit to extend and retract, and a second magnetic drive unit is provided in the second telescopic unit to drive the extension of the second telescopic unit to extend and retract.

6. The bidirectional intramedullary nail according to any one of claims 1-3, characterized in that, The bushing of the telescopic unit is inserted into the inside of the sleeve from the end of the sleeve and sleeved on the outside of the extension; The bushing is provided with a limiting flange at one end outside the sleeve. At least one sealing ring is fitted on the outer side of the bushing near the limiting eaves. When the bushing is installed into the sleeve, the limiting flange abuts against and fixes the end of the sleeve, and the interior of the bidirectional intramedullary nail is sealed as a whole by the at least one sealing ring.

7. The bidirectional intramedullary nail according to claim 6, characterized in that, The at least three-level limiting portion is provided, and the three-level limiting portion includes a first limiting portion, a second limiting portion, and a third limiting portion sequentially from the middle to the end of the sleeve, wherein... The first limiting part is disposed on the side of the magnetic drive part away from the output end, and when the magnetic drive part is assembled into the inside of the sleeve, the first limiting part limits its axial position. The second limiting part is disposed on one side of the input end of the deceleration part, and when the deceleration part is assembled into the inside of the sleeve, the second limiting part limits its axial position. The third limiting part is disposed on one side of the input end of the extension part, and when the extension part is assembled into the inside of the sleeve, the third limiting part limits its axial position.

8. The bidirectional intramedullary nail according to claim 7, characterized in that, The bushing, located inside the sleeve, abuts against the third limiting portion to define the axial position of the lead screw bearing assembly of the extension.

9. The bidirectional intramedullary nail according to claim 7, characterized in that, The bidirectional intramedullary nail further includes at least one first end screw-through hole, at least one second end screw-through hole, and at least one middle screw-through hole; The first end nailing through hole is located at the end of the output end of the extension of the first telescopic unit, and is used to fix the bone segment at one end by nailing. The second end nailing through hole is located at the end of the output end of the extension of the second telescopic unit, and is used to fix the bone segment at the other end by nailing. The central nailing hole is located in the middle of the sleeve and is used to fix the central bone segment by nailing.

10. The bidirectional intramedullary nail according to claim 9, characterized in that, The bidirectional intramedullary nail also includes locking screws for fixing bone segments. The locking pin includes a front self-tapping head, a middle smooth post, and an end threaded post connected together in sequence; The front-end self-tapping head has a tapered guide structure and its surface is provided with self-tapping threads; The diameter of the intermediate smooth column is equal to the maximum outer diameter of the front self-tapping head; The end threaded post includes a first thread located near the intermediate smooth post and a second thread located at the rear end of the first thread, wherein the pitch of the first thread is smaller than the pitch of the second thread.

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