An intramedullary fixation device for tubular bone fractures and methods of use thereof

Abstract

The application discloses an intramedullary fixation device for tubular bone fracture, which comprises an intramedullary nail, an anchoring structure, an adjusting mechanism and an angle locking mechanism; the intramedullary nail is used for implanting into a bone marrow cavity to provide a fracture fixation support; the anchoring structure is movably arranged on the intramedullary nail, and the anchoring structure is provided with at least one anchoring wing, and the anchoring wing has multiple unfolding angles; the adjusting mechanism is in transmission connection with the anchoring structure, and the adjusting mechanism is used for driving each anchoring wing to switch between different unfolding angles; the angle locking mechanism is linked with the adjusting mechanism, and the angle locking mechanism is provided with multiple preset unfolding angle gears, and the angle locking mechanism is used for locking the anchoring wing at a target unfolding angle. The application solves the problem that the existing intramedullary nail cannot be graded and adjusted after implantation.

Description

Technical Field

[0001] This invention relates to the field of intramedullary fixation devices, and more particularly to an intramedullary fixation device for tubular bone fractures and its method of use. Background Technology

[0002] Tubular bone fractures are among the most common types of fractures in clinical practice, with particularly high incidences in the hands, forearms, and feet. Currently, commonly used internal fixation methods include mini-plates, Kirschner wires, and intramedullary nails. Mini-plates require extensive soft tissue dissection, significantly disrupting blood supply to the fracture ends; while Kirschner wires are simple to use, they have weak anti-rotation and anti-displacement capabilities, making reliable fixation difficult; traditional intramedullary nails rely primarily on interference fit between the nail and the medullary cavity or end cap compression for locking, resulting in a relatively simple locking mechanism.

[0003] However, once the aforementioned internal fixation method is implanted, its locking state remains fixed and cannot be adjusted according to the fracture healing process. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide an intramedullary fixation device for tubular bone fractures and its method of use, so as to solve the problem that the locking force cannot be adjusted in stages after implantation of existing intramedullary nails.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] An intramedullary fixation device for tubular bone fractures, comprising:

[0007] Intramedullary nail, which is used to be implanted into the medullary cavity to provide fracture fixation support;

[0008] An anchoring structure, which is movably disposed on the intramedullary nail, the anchoring structure having at least one anchoring wing, the anchoring wing having multiple deployment angles;

[0009] An adjustment mechanism is connected to the anchoring structure in a transmission manner, and the adjustment mechanism is used to drive each of the anchoring wings to switch between different deployment angles;

[0010] An angle locking mechanism is linked to the adjustment mechanism. The angle locking mechanism has multiple preset deployment angle positions and is used to lock the anchoring wing at the target deployment angle.

[0011] Furthermore, the intramedullary nail is provided with an operating cavity and a guide channel; the operating cavity extends along the axial direction of the intramedullary nail, and the guide channel penetrates the side wall of the intramedullary nail for the anchoring wing to pass through and limit the swing angle of the anchoring wing; the anchoring structure also includes an operating rod, which is axially slidably disposed in the operating cavity, and the anchoring wing is hinged to the operating rod and driven by the operating rod and limited by the guide channel to switch the deployment angle.

[0012] Furthermore, the adjustment mechanism includes a first threaded structure and a second threaded structure. The first threaded structure is disposed on the operating rod, and the second threaded structure is rotatably disposed on the intramedullary nail. The second threaded structure is threadedly engaged with the first threaded structure of the operating rod, so that when the second threaded structure rotates, it drives the operating rod to move along the operating cavity.

[0013] Furthermore, the intramedullary nail is provided with an axial limiting structure, and the second threaded structure is provided with a limiting block, which is slidably fitted to the axial limiting structure.

[0014] Furthermore, the angle locking mechanism includes a positioning element; the second threaded structure is provided with a first positioning hole; the intramedullary nail is provided with a plurality of second positioning holes spaced apart along its circumference, each second positioning hole corresponding to the deployment angle of one of the anchoring wings; when the second threaded structure rotates, the first positioning hole can selectively align with and communicate with one of the second positioning holes to form a locking channel; the positioning element is pluggably inserted into the locking channel to lock the relative position of the second threaded structure and the intramedullary nail.

[0015] Furthermore, the second positioning hole has three parts, namely a first position hole, a second position hole, and a third position hole; the first position hole corresponds to the anchor wing swinging 60°-90°, and is used to drive the anchor wing to a fully deployed state; the second position hole corresponds to the anchor wing swinging 30°-50°, and is used to drive the anchor wing to a partially deployed state; the third position hole corresponds to the anchor wing swinging 0°, and is used to drive the anchor wing to a fully retracted state.

[0016] Furthermore, the second threaded structure is provided with a clamping structure for rotating in conjunction with an external tool.

[0017] Furthermore, the surface of the anchoring wing is provided with a serrated structure, which is used to increase the anchoring force with the bone marrow cavity wall.

[0018] A method of using an intramedullary fixation device for tubular bone fractures includes the following steps:

[0019] During the preparation phase, the adjustment mechanism is adjusted to fully retract the anchoring wing, and then locked by the angle locking mechanism.

[0020] During the implantation phase, the adjustment mechanism is adjusted to fully deploy the anchoring wing, which is then locked by the angle locking mechanism.

[0021] During the healing phase, the adjustment mechanism is adjusted to gradually retract the anchoring wing, which is then locked by the angle locking mechanism.

[0022] During the removal phase, the adjustment mechanism is adjusted to fully retract the anchoring wing, and the intramedullary nail is removed.

[0023] Furthermore, the preparation stage includes: rotating the second threaded structure to align the first positioning hole with the third position hole, and inserting the positioning member into the aligned hole;

[0024] The implantation stage includes: implanting the intramedullary nail into the medullary cavity, so that the intramedullary nail crosses the fracture line; pulling out the positioning element, rotating the second threaded structure to align the first positioning hole with the first position hole, and re-inserting the positioning element to fully deploy the anchoring wing and anchor it to the medullary cavity wall;

[0025] The healing stage includes: removing the positioning component according to the healing situation, rotating the second threaded structure to align the first positioning hole with the second position hole, re-inserting the positioning component, and gradually retracting the anchoring wing to allow the bone to gradually bear the stress.

[0026] The removal stage includes pulling out the positioning element, rotating the second threaded structure to align the first positioning hole with the third position hole, re-inserting the positioning element to fully retract the anchoring wing, and removing the intramedullary nail.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. Based on the intramedullary nail implanted into the medullary cavity to provide fracture fixation support, and with the help of movable anchoring structures, the initial positioning and stable support of the intramedullary nail in the medullary cavity are achieved.

[0029] 2. Based on the transmission connection between the adjustment mechanism and the anchoring structure, the adjustment mechanism drives the anchoring wing to switch between different deployment angles, so that the anchoring wing can select the corresponding deployment angle according to the fracture healing process, and realize the gradual adjustment from rigid fixation to partial fixation.

[0030] 3. Based on the linkage between the angle locking mechanism and the adjustment mechanism, the angle locking mechanism has multiple preset deployment angle positions and locks the anchoring wing at the target deployment angle to ensure that the anchoring wing maintains a stable deployment state at each stage of fracture healing and avoids fixation failure due to accidental loosening. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of an intramedullary fixation device for tubular bone fractures according to the present invention;

[0032] Figure 2 for Figure 1 A cross-sectional view of the structural schematic diagram shown;

[0033] Figure 3 for Figure 2 A magnified view of point A shown below;

[0034] Figure 4 for Figure 2 A magnified view of point B shown.

[0035] In the diagram: 1. Intramedullary nail; 101. Operating cavity; 102. Guide channel; 103. Axial limiting structure; 104. Second positioning hole; 2. Anchoring structure; 201. Anchoring wing; 202. Serrated structure; 203. Operating rod; 3. Adjustment mechanism; 301. First threaded structure; 302. Second threaded structure; 303. Limiting block; 304. First positioning hole; 305. Clamping structure; 6. Positioning component. Detailed Implementation

[0036] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0037] It should be noted that when an element is described as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is described as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementations.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] See Figures 1-4 A preferred embodiment of the present invention is described below:

[0040] An intramedullary fixation device for tubular bone fractures includes: an intramedullary nail 1, an anchoring structure 2, an adjustment mechanism 3, and an angle locking mechanism. The intramedullary nail 1 is implanted into the medullary cavity to provide fracture fixation support. The anchoring structure 2 is movably mounted on the intramedullary nail 1 and has at least one anchoring wing 201 with multiple deployment angles. The adjustment mechanism 3 is driven by the anchoring structure 2 and is used to switch the anchoring wings 201 between different deployment angles. The angle locking mechanism is linked to the adjustment mechanism 3 and has multiple preset deployment angle positions. The angle locking mechanism is used to lock the anchoring wings 201 at the target deployment angle. After the intramedullary nail 1 is implanted into the medullary cavity, the adjustment mechanism 3 drives the anchoring wings 201 to switch between different deployment angles, and the angle locking mechanism locks the anchoring wings 201 at the target deployment angle to adapt to the fixation needs at different stages of fracture healing.

[0041] The doctor rotates the adjustment mechanism 3 using an external tool. The adjustment mechanism 3 can be threaded, thereby driving the anchoring structure 2 to move axially. During the movement, the anchoring wing 201 is limited by the side wall of the intramedullary nail 1, changing its deployment angle. When the anchoring wing 201 reaches the target deployment angle, the angle locking mechanism locks the adjustment mechanism 3 in the corresponding position, maintaining the anchoring wing 201 at that deployment angle. If further adjustment is needed, the angle lock must be released first, and the adjustment mechanism 3 must be rotated again to the new target angle before locking it again.

[0042] It is understandable that the intramedullary nail 1, implanted within the medullary cavity, provides fracture fixation support, and, in conjunction with the movable anchoring structure 2, achieves initial positioning and stable support of the intramedullary nail 1 within the medullary cavity. Based on the transmission connection between the adjustment mechanism 3 and the anchoring structure 2, the adjustment mechanism 3 drives the anchoring wing 201 to switch between different deployment angles, allowing the anchoring wing 201 to select the appropriate deployment angle according to the fracture healing process, achieving a gradual adjustment from rigid fixation to partial fixation. Based on the linkage between the angle locking mechanism and the adjustment mechanism 3, the angle locking mechanism has multiple preset deployment angle settings and locks the anchoring wing 201 at the target deployment angle, ensuring that the anchoring wing 201 maintains a stable deployment state at each stage of fracture healing, preventing fixation failure due to accidental loosening.

[0043] In this embodiment, the adjustment mechanism 3 adopts a threaded transmission structure. The doctor clamps the clamping structure 305 of the second threaded structure 302 with an external tool and rotates it. The second threaded structure 302 rotates relative to the intramedullary nail 1, driving the operating rod 203 to move axially through the threaded engagement. The operating rod 203 drives the anchoring wing 201 to move along the guide channel 102. The anchoring wing 201 is limited by the side wall of the guide channel 102, changing its deployment angle. When the anchoring wing 201 reaches the target deployment angle, the positioning member 6 is inserted into the locking channel formed by the alignment of the first positioning hole 304 and the corresponding second positioning hole 104, locking the relative position of the second threaded structure 302 and the intramedullary nail 1, so that the anchoring wing 201 maintains the current deployment angle. This method requires a small incision on the body surface to expose the adjustment mechanism 3 for operation and is suitable for routine surgical scenarios.

[0044] In addition, the intramedullary nail 1 can be made of titanium alloy, cobalt-chromium-molybdenum alloy, or nickel-titanium shape memory alloy. Titanium alloy and cobalt-chromium-molybdenum alloy are suitable for conventional fixation, while shape memory alloy can achieve self-expansion. The surface of the operating rod 203 can be coated with a DLC coating to reduce friction between structures. The number of anchoring wings 201 can be selected from two to six depending on the fracture type. Two wings are suitable for simple fractures, three wings for complex fractures, four wings for severe comminuted fractures, five or six wings for osteoporotic patients, circular wings for osteoporosis, and V-shaped wings for oblique fractures. The adjustment mechanism 3 can be operated manually, mechanically, or pneumatically. Manual operation is achieved through external tools, while mechanical locking provides position feedback through a locking structure. The surface of the anchoring wings 201 can be provided with a serrated structure 202, a hydroxyapatite coating, or an antibacterial coating to enhance anchoring force. The surface of the operating lever 203 can also be equipped with depth scale lines along the axial direction to indicate the current deployment angle of the anchoring wing 201. The adjustment mechanism 3 is also equipped with a ratchet-type limiting structure. When the anchoring wing 201 rotates to each preset deployment angle, the limiting structure emits a corresponding "click" sound and tactile feedback to indicate to the operator that it is in place. The proximal end of the operating lever 203 is equipped with a standard tool interface; if the operating lever breaks, a special extractor can be screwed into this interface to remove the remaining lever. The proximal end of the intramedullary nail 1 is equipped with a countersunk structure. After the adjustment mechanism 3 and the angle locking mechanism are locked, the height of its top end is lower than the outer surface of the intramedullary nail to avoid postoperative soft tissue irritation. The outer diameter and length of the intramedullary nail 1 can be selected according to different locations such as metacarpals, phalanges, toe bones, ulna, and radius. Among them, the intramedullary nail 1 with an outer diameter greater than 1.5 mm retains the threaded adjustment mechanism, while the intramedullary nail 1 with an outer diameter less than or equal to 1.5 mm can adopt a push-tube type or a flexible self-opening structure.

[0045] Preferably, the intramedullary nail 1 has an operating cavity 101 and a guide channel 102. The operating cavity 101 extends axially along the intramedullary nail 1, and the guide channel 102 penetrates the sidewall of the intramedullary nail 1 to allow the anchoring wing 201 to pass through and to limit the swing angle of the anchoring wing 201. The anchoring structure 2 also includes an operating rod 203, which is axially slidably disposed within the operating cavity 101. The anchoring wing 201 is hinged to the operating rod 203 and is driven by the operating rod 203 and limited by the guide channel 102 to switch the deployment angle. When the operating rod 203 moves axially along the operating cavity 101, it drives the anchoring wing 201 to slide along the guide channel 102. During the sliding process, the anchoring wing 201 is limited by the sidewall of the guide channel 102 and is forced to swing around the hinge point.

[0046] When the operating lever 203 moves axially along the operating cavity 101, it causes the anchoring wing 201 to slide along the guide channel 102. During the sliding process, the anchoring wing 201 abuts against the side wall of the guide channel 102 and swings around the hinge point due to the limitation of the side wall. When the operating lever 203 moves to the distal end, the anchoring wing 201 slides to the distal end, and the side wall of the guide channel 102 presses against the anchoring wing 201, forcing the anchoring wing 201 to unfold outward; when the operating lever 203 moves to the proximal end, the anchoring wing 201 slides to the proximal end, and the side wall of the guide channel 102 presses against the anchoring wing 201, forcing the anchoring wing 201 to retract inward. By controlling the axial displacement of the operating lever 203, the anchoring wing 201 can be switched to different preset unfolding angles.

[0047] The intramedullary nail 1 is a hollow tube with an axially extending operating cavity 101 inside and a guide channel 102 on its side wall. An operating rod 203 is axially slidably mounted within the operating cavity 101. An anchoring wing 201 is hinged to the distal end of the operating rod 203. The anchoring wing 201 passes through the guide channel 102 via a sealing structure and can slide along the guide channel 102. The side wall of the guide channel 102 abuts against the surface of the anchoring wing 201. A linear bearing can also be installed between the operating rod 203 and the intramedullary nail 1 to reduce sliding friction, and an O-ring can be added to prevent body fluid from seeping into the intramedullary nail 1. The guide channel 102 can also be designed with an arc-shaped side wall to accommodate the swing trajectory of the anchoring wing 201. A torsion spring can also be added at the hinge point between the anchoring wing 201 and the operating rod 203 to provide a retraction and repositioning force.

[0048] Preferably, the adjusting mechanism 3 includes a first threaded structure 301 and a second threaded structure 302. The first threaded structure 301 is disposed on the operating rod 203, and the second threaded structure 302 is rotatably disposed on the intramedullary nail 1. The second threaded structure 302 is threadedly engaged with the first threaded structure 301 of the operating rod 203, so that when the second threaded structure 302 rotates, it drives the operating rod 203 to move along the operating cavity 101. When the second threaded structure 302 rotates, the rotational motion is converted into axial movement of the operating rod 203 through the threaded engagement of the first threaded structure 301 and the second threaded structure 302, thereby driving the anchoring wing 201 to switch its deployment angle.

[0049] An external tool clamps and rotates the clamping structure 305 of the second threaded structure 302. The second threaded structure 302, constrained by the axial limiting structure 103, maintains its axial position and only rotates circumferentially. The second threaded structure 302 drives the operating rod 203 to move axially along the operating cavity 101 via threaded engagement. When the second threaded structure 302 rotates in the first direction, the operating rod 203 moves distally, causing the anchoring wing 201 to unfold outwards; when the second threaded structure 302 rotates in the second direction, the operating rod 203 moves proximally, causing the anchoring wing 201 to retract inwards. By controlling the rotation direction and number of rotations of the second threaded structure 302, the operating rod 203 can be moved to the target position, causing the anchoring wing 201 to switch to the corresponding preset unfolding angle.

[0050] The proximal end of the operating lever 203 is provided with a first threaded structure 301, and a second threaded structure 302 is rotatably mounted on the proximal end of the intramedullary nail 1. The second threaded structure 302 has an internal thread on its inner wall, which engages with the first threaded structure 301 of the operating lever 203. The outer wall of the second threaded structure 302 is provided with a clamping structure 305 for external tools to clamp and rotate. The proximal end of the intramedullary nail 1 is provided with an axial limiting structure 103, and the second threaded structure 302 is provided with a limiting block 303. The limiting block 303 is slidably fitted into the axial limiting structure 103, so that the second threaded structure 302 maintains its axial position during rotation. A rolling bearing can also be provided between the second threaded structure 302 and the intramedullary nail 1 to reduce rotational friction. The first threaded structure 301 and the second threaded structure 302 can also use trapezoidal or rectangular threads to increase transmission efficiency. The clamping structure 305 can also be designed as an internal hexagonal hole, an external hexagonal head, or a cross-groove to accommodate different tools.

[0051] Preferably, the intramedullary nail 1 is provided with an axial limiting structure 103, and the second threaded structure 302 is provided with a limiting block 303, which can be slidably fitted to the axial limiting structure 103.

[0052] An axial limiting structure 103 is provided on the proximal inner wall of the intramedullary nail 1. The axial limiting structure 103 is either an axially distributed groove or an annular limiting step. A limiting block 303 is provided on the outer wall of the second thread structure 302. The limiting block 303 matches the axial limiting structure 103 and is slidably fitted therein. The axial limiting structure 103 can also be designed as an annular groove continuously distributed circumferentially, with the limiting block 303 correspondingly configured as an annular flange; the axial limiting structure 103 can also adopt a multi-segmented groove, with the limiting block 303 correspondingly configured as multiple circumferentially distributed protrusions. A thrust bearing can also be provided between the second thread structure 302 and the intramedullary nail 1 to reduce axial friction during rotation.

[0053] When an external tool drives the second threaded structure 302 to rotate, the limiting block 303 slides within the axial limiting structure 103. The axial limiting structure 103 forms an axial constraint on the limiting block 303, preventing the second threaded structure 302 from moving axially. Under the combined action of the limiting block 303 and the axial limiting structure 103, the second threaded structure 302 maintains a fixed axial position and only rotates circumferentially. The second threaded structure 302 transmits the rotational motion to the operating rod 203 through the threaded engagement, driving the operating rod 203 to move axially, thereby adjusting the deployment angle of the anchoring wing 201.

[0054] Preferably, the angle locking mechanism includes a positioning element 6; a first positioning hole 304 is provided on the second threaded structure 302; a plurality of second positioning holes 104 are provided on the intramedullary nail 1 at intervals along its circumference, each second positioning hole 104 corresponding to the deployment angle of an anchoring wing 201; when the second threaded structure 302 rotates, the first positioning hole 304 can selectively align with and communicate with one of the second positioning holes 104 to form a locking channel; the positioning element 6 is pluggably inserted into the locking channel to lock the relative position of the second threaded structure 302 and the intramedullary nail 1. The positioning element 6 is inserted into the locking channel formed by the alignment of the first positioning hole 304 and the second positioning hole 104 to lock the relative position of the second threaded structure 302 and the intramedullary nail 1, so that the anchoring wing 201 is maintained at the target deployment angle.

[0055] The outer wall of the second threaded structure 302 is provided with a first positioning hole 304. Multiple second positioning holes 104 are distributed circumferentially at intervals on the proximal sidewall of the intramedullary nail 1. Each second positioning hole 104 corresponds to a preset deployment angle of the anchoring wing 201. The first positioning hole 304 and the second positioning hole 104 have the same diameter. When the second threaded structure 302 rotates to the target position, the first positioning hole 304 aligns with and connects to the corresponding second positioning hole 104, forming a locking channel. The positioning element 6 is a cylindrical pin or elastic pin made of a high-toughness medical alloy, and its outer diameter matches the inner diameter of the locking channel. The positioning element 6 can also be designed as a threaded pin, with an internal thread corresponding to the inner wall of the locking channel. The second positioning holes 104 can also be distributed at equal angles circumferentially, with the included angle between adjacent second positioning holes 104 corresponding to the gradient of the deployment angle of the anchoring wing 201.

[0056] When the second threaded structure 302 rotates to the target position, the first positioning hole 304 aligns with the second positioning hole 104 corresponding to the preset deployment angle, forming a through locking channel. The positioning member 6 is inserted into the locking channel, passing through both the first positioning hole 304 and the second positioning hole 104, thus constraining the relative rotation of the second threaded structure 302 and the intramedullary nail 1. Under the locking action of the positioning member 6, the second threaded structure 302 cannot rotate, the axial position of the operating rod 203 is fixed, and the anchoring wing 201 remains at the current deployment angle. To switch to another deployment angle, remove the positioning member 6, rotate the second threaded structure 302 to the new target position, align the first positioning hole 304 with the other second positioning hole 104, and reinsert the positioning member 6 to complete the locking.

[0057] In addition, a snap-fit ​​structure is provided between the second threaded structure 302 and the intramedullary nail 1. The snap-fit ​​structure includes multiple snap-fit ​​protrusions distributed circumferentially and corresponding snap-fit ​​grooves. Each snap-fit ​​protrusion and snap-fit ​​groove corresponds to a preset unfolding angle. When the second threaded structure 302 rotates, the snap-fit ​​protrusions slide into the snap-fit ​​grooves in sequence to generate tactile feedback and sound, which facilitates the alignment of the first positioning hole 304 with the target second positioning hole 104.

[0058] Preferably, the second positioning hole 104 has three holes, namely a first position hole, a second position hole, and a third position hole; the first position hole corresponds to the anchor wing 201 swinging 60°-90°, used to drive the anchor wing 201 to the fully deployed state; the second position hole corresponds to the anchor wing 201 swinging 30°-50°, used to drive the anchor wing 201 to the partially deployed state; the third position hole corresponds to the anchor wing 201 swinging 0°, used to drive the anchor wing 201 to the fully retracted state. The three position holes correspond to different swing angles of the anchor wing 201. By selecting different second positioning holes 104 to align with the first positioning hole 304, the anchor wing 201 can be locked in the fully deployed, partially deployed, or fully retracted state.

[0059] The intramedullary nail 1 has three second positioning holes 104, namely a first position hole, a second position hole, and a third position hole, which are distributed circumferentially around the intramedullary nail 1. The first position hole corresponds to the anchor wing 201 swinging 60° to 90°, at which time the anchor wing 201 is in a fully deployed state; the second position hole corresponds to the anchor wing 201 swinging 30° to 50°, at which time the anchor wing 201 is in a partially deployed state; the third position hole corresponds to the anchor wing 201 swinging 0°, at which time the anchor wing 201 is in a fully retracted state. The circumferential spacing of the three position holes is determined by the conversion of the thread lead of the second thread structure 302 and the operating rod 203, so that when the second thread structure 302 rotates to each position hole, the operating rod 203 moves to the corresponding axial position. The three position holes have the same diameter, which is consistent with the diameter of the first positioning hole 304. Four or five position holes can also be provided to provide more deployment angle options.

[0060] When the anchoring wing 201 needs to be fully extended, rotate the second threaded structure 302 to align the first positioning hole 304 with the first position hole, insert the positioning piece 6 to lock it in place. At this time, the anchoring wing 201 swings 60° to 90°, forming the maximum anchoring area with the medullary cavity wall. When the fracture enters the mid-healing stage and the locking force needs to be reduced, pull out the positioning piece 6, rotate the second threaded structure 302 to align the first positioning hole 304 with the second position hole, and reinsert the positioning piece 6 to lock it in place. At this time, the anchoring wing 201 swings 30° to 50°, the anchoring area decreases, and the locking force is partially released. When the fracture has fully healed and the intramedullary nail 1 needs to be removed, rotate the second threaded structure 302 to align the first positioning hole 304 with the third position hole, insert the positioning piece 6 to lock it in place. At this time, the anchoring wing 201 swings 0° and is completely retracted within the outer diameter range of the intramedullary nail 1, allowing the intramedullary nail 1 to be easily removed.

[0061] Preferably, the surface of the anchoring wing 201 is provided with a serrated structure 202, which is used to increase the anchoring force with the medullary cavity wall. When the anchoring wing 201 is deployed, the serrated structure 202 embeds into the medullary cavity wall, increasing the friction and anchoring force between the anchoring wing 201 and the bone cortex, and preventing the intramedullary nail 1 from rotating or shifting.

[0062] When the anchoring wing 201 deploys and contacts the medullary cavity wall, the tips of the serrated structure 202 embed into the cortical bone of the medullary cavity wall under the deployment force of the anchoring wing 201. Multiple tips embed simultaneously, forming multi-point anchoring, significantly increasing the contact area and friction between the anchoring wing 201 and the cortical bone. When the intramedullary nail 1 is subjected to rotational or axial tension, the serrated structure 202 provides resistance, preventing the intramedullary nail 1 from rotating or dislodging. After fracture healing, when the anchoring wing 201 retracts, the serrated structure 202 withdraws from the cortical bone without affecting the removal of the intramedullary nail 1.

[0063] The outer surface of the anchoring wing 201 is provided with a serrated structure 202, which extends along the length of the anchoring wing 201 and consists of multiple continuously arranged tooth tips and grooves. The tooth tips of the serrated structure 202 are inclined towards the deployment direction of the anchoring wing 201, making it easier for the tooth tips to embed into the bone cortex when the anchoring wing 201 is deployed. The serrated structure 202 can also adopt a barbed structure, that is, the tooth tips are inclined towards the proximal end of the anchoring wing 201 to enhance the pull-out resistance. The surface of the anchoring wing 201 can also be coated with a hydroxyapatite coating or a titanium coating, which, in conjunction with the serrated structure 202, further promotes osseointegration. The distal end of the anchoring wing 201 can also be provided with a pointed cutting edge for cutting into the bone cortex when deployed.

[0064] Preferably, the second threaded structure 302 is provided with a clamping structure 305, which is used to rotate in conjunction with an external tool.

[0065] The proximal end face or outer wall of the second threaded structure 302 is provided with a clamping structure 305, which matches the shape of the external tool. The clamping structure 305 can be in the form of an internal hexagonal hole, located at the center of the end face of the second threaded structure 302, for inserting and rotating an internal hexagonal wrench; it can also be in the form of an external hexagonal head, located at the proximal end of the second threaded structure 302, for clamping a socket wrench; or it can be in the form of a cross-shaped or flat slot for screwdrivers to rotate. The clamping structure 305 can also be designed as a polygonal countersunk hole, a Torx-shaped hole, or a square hole to accommodate different types of external tools. The outer wall of the second threaded structure 302 can also be knurled or textured for manual gripping and rotation by the doctor.

[0066] When adjusting the deployment angle of the anchoring wing 201, the doctor selects an external tool that matches the clamping structure 305 and mates the tool with the clamping structure 305. When the external tool is rotated, the clamping structure 305 transmits torque to the second threaded structure 302, driving the second threaded structure 302 to rotate. The second threaded structure 302, through threaded engagement, drives the operating rod 203 to move axially, switching the anchoring wing 201 to the target deployment angle. After adjustment, the external tool is removed; the clamping structure 305 does not participate in locking but only serves as a drive interface. When further adjustment is needed, the external tool is re-mated for repeated operation.

[0067] A method for using an intramedullary fixation device for tubular bone fractures includes the following steps: In the preparation stage, adjusting the adjustment mechanism 3 to fully retract the anchor wings 201 and locking them using the angle locking mechanism; in the implantation stage, adjusting the mechanism 3 to fully extend the anchor wings 201 and locking them using the angle locking mechanism; in the healing stage, adjusting the mechanism 3 to gradually retract the anchor wings 201 and locking them using the angle locking mechanism; and in the removal stage, adjusting the mechanism 3 to fully retract the anchor wings 201 and removing the intramedullary nail 1. By adjusting the extension angle of the anchor wings 201 in stages, the intramedullary nail 1 provides matching fixation strength at different stages of fracture healing, achieving progressive mechanical support from rigid fixation to complete release.

[0068] The method of use applies to the aforementioned intramedullary fixation device, which includes an intramedullary nail 1, an anchoring structure 2, an adjustment mechanism 3, and an angle locking mechanism. The intramedullary nail 1 is a hollow tube with a guide channel 102 on its side wall. The anchoring structure 2 includes an operating rod 203 and an anchoring wing 201 hinged to the distal end of the operating rod 203. The operating rod 203 is axially slidably fitted into the intramedullary nail 1, and the anchoring wing 201 passes through the guide channel 102. The adjustment mechanism 3 includes a first threaded structure 301 and a second threaded structure 302, and the operating rod 203 is driven to move axially by rotating the second threaded structure 302. The angle locking mechanism includes a positioning element 6 and multiple second positioning holes 104 for locking the position of the adjustment mechanism 3.

[0069] In the preparation phase, the doctor rotates the second threaded structure 302, causing the operating rod 203 to move proximally. This causes the anchoring wing 201 to slide proximally along the guide channel 102, where it is completely retracted within the outer diameter range of the intramedullary nail 1 by the side wall of the guide channel 102. The positioning element 6 is then inserted into the corresponding second positioning hole 104 for locking. At this point, the intramedullary nail 1 can be successfully implanted into the medullary cavity. In the implantation phase, the positioning element 6 is removed, and the second threaded structure 302 is rotated in the opposite direction, causing the operating rod 203 to move distally. The anchoring wing 201 slides distally along the guide channel 102 and extends outward to its maximum angle, anchoring against the medullary cavity wall. The positioning element 6 is then inserted for locking, achieving strong fixation. In the healing phase, depending on the fracture healing progress, the positioning element 6 is removed, and the second threaded structure 302 is rotated to gradually move the operating rod 203 proximally. The anchoring wing 201 retracts step by step, and the positioning element 6 is inserted for locking after each adjustment to the target angle, gradually reducing the locking force and allowing the bone to gradually bear the stress. During the removal phase, after the anchoring wing 201 is fully retracted, it is inserted into the positioning piece 6 for locking. The extractor is then screwed into the threaded hole near the proximal end of the intramedullary nail 1, and the intramedullary nail 1 is pulled out as a whole. In addition, the healing phase can be equipped with multiple positions. By switching to different positions in sequence, the anchoring wing 201 is retracted step by step, and the locking force is released in stages.

[0070] Preferably, the preparation stage includes: rotating the second threaded structure 302 to align the first positioning hole 304 with the third position hole, and inserting the positioning member 6 into the aligned hole; the implantation stage includes: implanting the intramedullary nail 1 into the medullary cavity, so that the intramedullary nail 1 crosses the fracture line; removing the positioning member 6, and reinserting the positioning member 6 to fully extend the anchoring wing 201 and anchor it to the medullary cavity wall; the healing stage includes: removing the positioning member 6 according to the healing situation, rotating the second threaded structure 302 to align the first positioning hole 304 with the second position hole, reinserting the positioning member 6 to gradually retract the anchoring wing 201 so that the bone can gradually bear the stress; the removal stage includes: removing the positioning member 6, rotating the second threaded structure 302 to align the first positioning hole 304 with the third position hole, reinserting the positioning member 6 to fully retract the anchoring wing 201, and removing the intramedullary nail 1. By aligning the first positioning hole 304 with the three position holes in sequence, the anchoring wing 201 can complete the entire operation cycle from fully retracted to fully extended, and then gradually retracted to fully retracted.

[0071] In the preparation stage, the second threaded structure 302 is rotated to align the first positioning hole 304 with the third position hole, and the positioning element 6 is inserted. The anchoring wing 201 is fully retracted, allowing the intramedullary nail 1 to be successfully implanted. In the implantation stage, the intramedullary nail 1 is implanted into the medullary cavity, with the locking part crossing the fracture line. The positioning element 6 is removed, the second threaded structure 302 is rotated to align the first positioning hole 304 with the first position hole, and the positioning element 6 is reinserted. The anchoring wing 201, pushed by the operating rod 203, extends outward along the guide channel 102 to its maximum angle, anchoring itself to the medullary cavity wall. In the healing stage, depending on the fracture healing progress, the positioning element 6 is removed, the second threaded structure 302 is rotated to align the first positioning hole 304 with the second position hole, and the positioning element 6 is reinserted. The anchoring wing 201 partially retracts, reducing the locking force by 30% to 50%, and the bone begins to gradually bear stress. If further release of the locking force is required, this operation can be repeated to further retract the anchoring wing 201. During the removal phase, pull out the positioning element 6, rotate the second threaded structure 302 to align the first positioning hole 304 with the third position hole, reinsert the positioning element 6, fully retract the anchoring wing 201, and use the extractor to pull out the intramedullary nail 1 as a whole.

[0072] In summary, this invention comprises an intramedullary nail 1, an anchoring structure 2, an adjustment mechanism 3, and an angle locking mechanism. The intramedullary nail 1 is a hollow tube with an internal operating cavity 101 and a guide channel 102 on its sidewall, used for implantation into the medullary cavity to provide fracture fixation support. The anchoring structure 2 includes an operating rod 203 and an anchoring wing 201 hinged to the distal end of the operating rod 203. The operating rod 203 is axially slidably mounted within the operating cavity 101, and the anchoring wing 201 passes through the guide channel 102, its deployment angle changing due to the limitation imposed by the sidewall of the guide channel 102. The adjustment mechanism 3 includes a first threaded structure 301 located proximal to the operating rod 203 and a second threaded structure 302 rotatably mounted proximal to the intramedullary nail 1. The second threaded structure 302 is threadedly engaged with the first threaded structure 301. Rotating the second threaded structure 302 drives the operating rod 203 to move axially, thereby switching the deployment angle of the anchoring wing 201. The angle locking mechanism includes a positioning element 6, a first positioning hole 304 on the second threaded structure 302, and multiple second positioning holes 104 spaced circumferentially on the intramedullary nail 1. Each second positioning hole 104 corresponds to a preset deployment angle of the anchoring wing 201. When the second threaded structure 302 rotates to the target position, the first positioning hole 304 aligns with the corresponding second positioning hole 104, and the positioning element 6 is inserted into the locking channel to lock the anchoring wing 201 at the current deployment angle. This invention achieves progressive mechanical support from rigid fixation to complete release during fracture healing through multiple preset deployment angles.

[0073] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0074] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0075] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An intramedullary fixation device for tubular bone fractures, characterized in that, include: Intramedullary nail (1), said intramedullary nail (1) is used to be implanted into the medullary cavity to provide fracture fixation support; An anchoring structure (2) is movably disposed on the intramedullary nail (1), and the anchoring structure (2) is provided with at least one anchoring wing (201) having multiple deployment angles; Adjustment mechanism (3), the adjustment mechanism (3) is connected to the anchoring structure (2) in a transmission manner, the adjustment mechanism (3) is used to drive each of the anchoring wings (201) to switch between different deployment angles; Angle locking mechanism, which is linked with the adjustment mechanism (3), has multiple preset deployment angle positions and is used to lock the anchor wing (201) at the target deployment angle.

2. The intramedullary fixation device for tubular bone fractures according to claim 1, characterized in that, The intramedullary nail (1) is provided with an operating cavity (101) and a guide channel (102); the operating cavity (101) extends along the axial direction of the intramedullary nail (1), and the guide channel (102) penetrates the side wall of the intramedullary nail (1) for the anchoring wing (201) to pass through and limit the swing angle of the anchoring wing (201); the anchoring structure (2) also includes an operating rod (203), the operating rod (203) is axially slidably disposed in the operating cavity (101), the anchoring wing (201) is hinged to the operating rod (203), and is driven by the operating rod (203) and limited by the guide channel (102) to switch the deployment angle.

3. The intramedullary fixation device for tubular bone fractures according to claim 2, characterized in that, The adjustment mechanism (3) includes a first threaded structure (301) and a second threaded structure (302). The first threaded structure (301) is disposed on the operating rod (203), and the second threaded structure (302) is rotatably disposed on the intramedullary nail (1). The second threaded structure (302) is threadedly engaged with the first threaded structure (301) of the operating rod (203) so that when the second threaded structure (302) rotates, it drives the operating rod (203) to move along the operating cavity (101).

4. The intramedullary fixation device for tubular bone fractures according to claim 3, characterized in that, The intramedullary nail (1) is provided with an axial limiting structure (103), and the second threaded structure (302) is provided with a limiting block (303), which is slidably fitted to the axial limiting structure (103).

5. The intramedullary fixation device for tubular bone fractures according to claim 3, characterized in that, The angle locking mechanism includes a positioning element (6); the second threaded structure (302) is provided with a first positioning hole (304); the intramedullary nail (1) is provided with a plurality of second positioning holes (104) distributed circumferentially, each of the second positioning holes (104) corresponding to the unfolding angle of one of the anchoring wings (201); when the second threaded structure (302) rotates, the first positioning hole (304) can selectively align with and communicate with one of the second positioning holes (104) to form a locking channel; the positioning element (6) can be inserted and removed into the locking channel to lock the relative position of the second threaded structure (302) and the intramedullary nail (1).

6. The intramedullary fixation device for tubular bone fractures according to claim 5, characterized in that, The second positioning hole (104) has three holes, namely a first position hole, a second position hole and a third position hole; the first position hole corresponds to the anchor wing (201) swinging 60°-90°, which is used to drive the anchor wing (201) to be in a fully deployed state; the second position hole corresponds to the anchor wing (201) swinging 30°-50°, which is used to drive the anchor wing (201) to be in a partially deployed state; the third position hole corresponds to the anchor wing (201) swinging 0°, which is used to drive the anchor wing (201) to be in a fully retracted state.

7. The intramedullary fixation device for tubular bone fractures according to claim 3, characterized in that, The second threaded structure (302) is provided with a clamping structure (305), which is used to rotate in conjunction with an external tool.

8. The intramedullary fixation device for tubular bone fractures according to claim 1, characterized in that, The surface of the anchoring wing (201) is provided with a serrated structure (202), which is used to increase the anchoring force with the wall of the medullary cavity.

9. A method of using an intramedullary fixation device for tubular bone fractures, comprising the intramedullary fixation device for tubular bone fractures as described in any one of claims 1 to 8, characterized in that, Includes the following steps: During the preparation phase, the adjustment mechanism (3) is adjusted to fully retract the anchoring wing (201) and lock it using the angle locking mechanism. During the implantation phase, the adjustment mechanism (3) is adjusted to fully deploy the anchoring wing (201) and lock it using the angle locking mechanism; During the healing phase, the adjustment mechanism (3) is adjusted to gradually retract the anchoring wing (201) and lock it through the angle locking mechanism; During the removal phase, the adjustment mechanism (3) is adjusted to fully retract the anchoring wing (201) and the intramedullary nail (1) is removed.

10. The method of using an intramedullary fixation device for tubular bone fractures according to claim 9, characterized in that, Includes the following steps: Preparation stage: Rotate the second threaded structure (302) to align the first positioning hole (304) with the third position hole, and insert the positioning member (6) into the aligned hole; The implantation stage includes: implanting the intramedullary nail (1) into the medullary cavity, so that the intramedullary nail (1) crosses the fracture line; Pull out the positioning element (6), rotate the second threaded structure (302) to align the first positioning hole (304) with the first position hole, reinsert the positioning element (6) to fully unfold the anchoring wing (201) and anchor it to the bone marrow cavity wall; Healing stage: According to the healing situation, pull out the positioning piece (6), rotate the second thread structure (302) to align the first positioning hole (304) with the second position hole, reinsert the positioning piece (6) to gradually retract the anchoring wing (201) so that the bone can gradually bear the stress. Removal stage: Pull out the positioning element (6), rotate the second threaded structure (302) to align the first positioning hole (304) with the third position hole, reinsert the positioning element (6) to fully retract the anchoring wing (201), and remove the intramedullary nail (1).

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