Intramedullary nail mechanism

Abstract

The present invention provides an intramedullary nail mechanism, comprising: a first implant nail; a second implant nail, which is inserted through the first end of the first implant nail and is inclined relative to the first implant nail; a third implant nail, which is inserted through the middle part of the first implant nail and is inclined relative to the first implant nail, wherein the third implant nail comprises a first connecting nail segment and a second connecting nail segment, the first connecting nail segment and the second connecting nail segment can move relative to each other, the first end of the first connecting nail segment is connected to the second implant nail, the second connecting nail segment is inserted through the middle part of the first implant nail, and an elastic buffer structure is arranged between the second end of the first connecting nail segment and the first end of the second connecting nail segment. The technical solution of the present application effectively solves the problem that the intramedullary nail implanted into the femur cuts out of the femur in the related art.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and more particularly, to an intramedullary nail mechanism. Background Art

[0002] For unstable intertrochanteric fractures of the femur, femoral intramedullary nails are usually used for fixation. The first implant nail passes through the femoral medullary cavity, and the eccentricity distance is relatively short. The possibility of postoperative internal fixation failure is relatively small compared to external fixation. The intramedullary nail can be implanted to reconstruct the connection of the intertrochanteric fracture site of the femur, and the limb function of the patient can be restored after fracture healing. However, the current femoral intramedullary nail mechanism still has a relatively high proportion of internal fixation failure in the treatment of unstable intertrochanteric fractures of the femur.

[0003] Research shows that the medial wall, lateral wall, and superior lateral wall of the proximal femur are important structural bases for maintaining the stability of the proximal femur. They are equivalent to the medial side, lateral side, and superior side of the mechanical triangle ("Ward's triangle") in theoretical mechanics analysis. Theoretical analysis shows that the treatment of proximal femoral fractures should take into account the simultaneous reconstruction of the three sides to achieve fracture-end stability and avoid treatment failure.

[0004] Currently, after the intramedullary nail is implanted, a lever structure is formed. When treating unstable intertrochanteric fractures of the femur, it completely replaces the bone tissue to bear the stress during weight-bearing, resulting in stress concentration at the angled part of the internal fixation and poor resistance to oblique shear force in the outer lower direction. The importance of the stable support structure of the "Ward's triangle" formed by the tension trabeculae and compression trabeculae is ignored. The stability of the triangular support structure formed by the normal bone tissue is much better than the lever structure formed by the internal fixation replacing the normal structure. Moreover, all intramedullary nails are rigid structures, and the elastic modulus of the femoral system composed of metal materials is too high for bone quality, resulting in stress shielding during compression and easily causing problems such as the intramedullary nail cutting out of the femur. Summary of the Invention

[0005] The main purpose of the present invention is to provide an intramedullary nail mechanism to solve the problem of the intramedullary nail implanted into the femur cutting out of the femur in the related art.

[0006] To achieve the above object, the present invention provides an intramedullary nail mechanism, including: a first implant nail; a second implant nail, penetrating through the first end of the first implant nail and being inclined relative to the first implant nail; a third implant nail, penetrating through the middle of the first implant nail and being inclined relative to the first implant nail, wherein the third implant nail includes a first connecting nail segment and a second connecting nail segment, the first connecting nail segment and the second connecting nail segment can move relative to each other, the first end of the first connecting nail segment is connected to the second implant nail, the second connecting nail segment penetrates through the middle of the first implant nail, and an elastic buffer structure is provided between the second end of the first connecting nail segment and the first end of the second connecting nail segment.

[0007] Further, the second end of the first connecting pin segment and the first end of the second connecting pin segment are nested and fitted, and an inner hole is provided at the second end of the first connecting pin segment or the first end of the second connecting pin segment, and the elastic buffer structure is located within the inner hole.

[0008] Further, the inner hole is provided at the first end of the second connecting pin segment, the first connecting pin segment passes through the inner hole, the second connecting pin segment has a body portion and a buffer sleeve, the inner hole is provided at the end of the body portion, the buffer sleeve is disposed within the inner hole, and the elastic buffer structure is located between the first connecting pin segment and the bottom wall of the inner hole.

[0009] Further, the buffer sleeve is connected within the inner hole by injection molding, welding, bonding or screwing.

[0010] Further, the elastic buffer structure includes a spring; and / or, the material of the buffer sleeve is biopolycarbonate polyurethane.

[0011] Further, a first anti-rotation portion is provided on the second end of the first connecting pin segment, a second anti-rotation portion is provided on the buffer sleeve, and the first anti-rotation portion and the second anti-rotation portion are in anti-rotation fit.

[0012] Further, the first anti-rotation portion includes an axial groove, and the second anti-rotation portion includes an axial rib that is inserted and fitted with the axial groove.

[0013] Further, the axial dimension of the axial groove is greater than the axial dimension of the axial rib.

[0014] Further, a screw hole is provided on the second implanting nail, the axis of the screw hole is parallel to the axis of the first connecting pin segment, and the first connecting pin segment has a first threaded segment that is screwed and fitted with the screw hole.

[0015] Further, the first connecting pin segment includes a first threaded segment and a first smooth rod segment connected to the first threaded segment; the second connecting pin segment includes a second threaded segment, a second smooth rod segment, and a third threaded segment connected between the second threaded segment and the second smooth rod segment, the outer diameter of the second threaded segment is smaller than the outer diameter of the outer wall of the second smooth rod segment, the elastic buffer structure is disposed between the first smooth rod segment and the second threaded segment, an operation hole is provided at one end of the second smooth rod segment away from the third threaded segment, and one end of the second smooth rod segment away from the third threaded segment forms the second end of the second connecting pin segment; an external thread is provided at the first end of the second implanting nail, an operation groove is provided at the second end of the second implanting nail, and the first end of the first connecting pin segment is connected to the external thread; the first implanting nail includes a first nail segment and a second nail segment connected to the first nail segment, and the outer diameter of the first nail segment is greater than the outer diameter of the second nail segment; the second implanting nail is inserted through the first end of the first nail segment, and the first end and the second end of the second connecting pin segment are respectively located on both sides of the second end of the first nail segment; the intramedullary nail mechanism further includes a transverse nail inserted through the second nail segment.

[0016] Applying the technical solution of the present invention, the intramedullary nail mechanism includes: a first implant nail, a second implant nail and a third implant nail. The second implant nail is inserted through the first end of the first implant nail and is tilted relative to the first implant nail. The third implant nail is inserted through the middle of the first implant nail and is tilted relative to the first implant nail, so that a triangular area is defined between the first implant nail, the second implant nail and the third implant nail. Among them, the third implant nail includes a first connecting nail segment and a second connecting nail segment, the first connecting nail segment and the second connecting nail segment can move relative to each other, the first end of the first connecting nail segment is connected to the second implant nail, the second connecting nail segment is inserted through the middle of the first implant nail, and an elastic buffer structure is provided between the second end of the first connecting nail segment and the first end of the second connecting nail segment. During the process of implanting the intramedullary nail mechanism into the femur, the first implant nail is driven in, the second implant nail is inserted through the first end of the first implant nail, the fracture end is pressurized by the second implant nail, the third implant nail is inserted through the middle of the first implant nail, and the first end of the first connecting nail segment is connected to the second implant nail. After the intramedullary nail mechanism is implanted, the intramedullary nail mechanism is under pressure as a whole, and the pressure is transmitted to the first end of the first connecting nail segment, so that the third implant nail is under pressure, and the elastic buffer structure between the second end of the first connecting nail segment and the first end of the second connecting nail segment is under pressure and in a compressed state, and a damping force is generated on the first connecting nail segment. The second end of the first connecting nail segment gradually approaches the first end of the second connecting nail segment, so that the overall length of the third implant nail gradually decreases, and the pressure energy borne by the intramedullary nail mechanism is stored and dispersed by the elastic buffer structure, ensuring that the intramedullary nail mechanism is balanced in force and better disperses the pressure borne, so that the elastic buffer structure is retracted to slow down and weaken the load borne by the intramedullary nail mechanism instantly, reduce the elastic modulus of the intramedullary nail mechanism, and reduce stress shielding. In this way, the "ward triangle" can be effectively reconstructed, and a stable supporting intramedullary nail mechanism can be realized, which can not only effectively reposition and fix the femoral head of the patient, but also reconstruct the "ward triangle" at the femoral trochanter, and at the same time, the stress borne by the femur can be better dispersed, avoiding the intramedullary nail mechanism implanted in the femur from being cut out of the femur. Therefore, the technical solution of the present application can solve the problem in the related art that the intramedullary nail implanted in the femur is cut out of the femur. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 A perspective schematic diagram showing an intramedullary nail mechanism according to an embodiment of the present invention being implanted into a femur;

[0019] Figure 2 Shows Figure 1 A schematic diagram of the three-dimensional structure of the intramedullary nail mechanism;

[0020] Figure 3 shows a Figure 2 cross-sectional schematic view of the intramedullary nail mechanism;

[0021] Figure 4 shows a Figure 3 magnified schematic view at location A of the intramedullary nail mechanism;

[0022] Figure 5 shows a Figure 2 front view schematic view of the intramedullary nail mechanism;

[0023] Figure 6 shows a Figure 5 cross-sectional schematic view of the intramedullary nail mechanism;

[0024] Figure 7 shows a Figure 2 exploded structural schematic view of the intramedullary nail mechanism;

[0025] Figure 8 shows a Figure 7 three-dimensional structural schematic view of the first connecting nail segment and the buffer sleeve of the intramedullary nail mechanism;

[0026] Figure 9 shows a Figure 7 cross-sectional schematic view of the intramedullary nail mechanism;

[0027] Figure 10 shows a Figure 9 magnified schematic view at location B of the intramedullary nail mechanism;

[0028] Figure 11 shows a Figure 2 three-dimensional structural schematic view of the intramedullary nail mechanism from another angle;

[0029] Figure 12 shows a Figure 2 three-dimensional structural schematic view of the second implant nail of the intramedullary nail mechanism;

[0030] Figure 13 shows a Figure 2 three-dimensional structural schematic view of the second implant nail of the intramedullary nail mechanism from another angle;

[0031] Figure 14 shows a Figure 13 cross-sectional schematic view of the second implant nail;

[0032] Figure 15 shows a Figure 2 front view schematic view of the first implant nail of the intramedullary nail mechanism;

[0033] Figure 16 shows a Figure 2Front view schematic diagram of the second implant nail of the intramedullary nail mechanism.

[0034] Among them, the above-mentioned drawings include the following reference numerals:

[0035] 4. Femur; 10. First implant nail; 11. First nail segment; 12. Second nail segment; 20. Second implant nail; 21. External thread; 22. Operation groove; 23. Screw hole; 211. First rod body part; 212. Second rod body part; 216. Thread; 201. First groove; 202. Second groove; 30. Third implant nail; 31. First connecting nail segment; 311. First smooth rod segment; 312. First threaded segment; 32. Second connecting nail segment; 321. Second threaded segment; 322. Second smooth rod segment; 3221. Operation hole; 323. Third threaded segment; 33. Inner hole; 35. Axial groove; 36. Axial rib; 37. Connecting column; 40. Elastic buffer structure; 41. Spring; 42. Buffer sleeve; 50. Transverse nail. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way constitutes a limitation to the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0037] It should be noted that the terms used here are only for describing specific implementation manners and are not intended to limit the exemplary implementation manners according to the present application. As used here, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprise" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0039] As Figures 1 to 6 shown, the intramedullary nail mechanism of this embodiment includes: a first implant nail 10, a second implant nail 20, and a third implant nail 30. The second implant nail 20 is inserted through the first end of the first implant nail 10 and is inclined relative to the first implant nail 10. The third implant nail 30 is inserted through the middle of the first implant nail 10 and is inclined relative to the first implant nail 10, so as to define a triangular region among the first implant nail 10, the second implant nail 20, and the third implant nail 30. Wherein, the third implant nail 30 includes a first connecting nail segment 31 and a second connecting nail segment 32, the first connecting nail segment 31 and the second connecting nail segment 32 can move relative to each other, the first end of the first connecting nail segment 31 is connected to the second implant nail 20, the second connecting nail segment 32 is inserted through the middle of the first implant nail 10, and an elastic buffer structure 40 is arranged between the second end of the first connecting nail segment 31 and the first end of the second connecting nail segment 32.

[0040] The technical solution of this embodiment is applied to define a triangular area between the first implant nail 10, the second implant nail 20 and the third implant nail 30. The third implant nail 30 includes a first connecting nail segment 31 and a second connecting nail segment 32, and the first connecting nail segment 31 and the second connecting nail segment 32 can move relative to each other. The first end of the first connecting nail segment 31 is connected to the second implant nail 20, and the second connecting nail segment 32 is inserted in the middle of the first implant nail 10. An elastic buffer structure 40 is provided between the second end of the first connecting nail segment 31 and the first end of the second connecting nail segment 32. During the process of implanting the intramedullary nail mechanism into the femur 4, the first implant nail 10 is driven in, the second implant nail 20 is inserted in the first end of the first implant nail 10, and the fracture end is pressurized by the second implant nail 20. The third implant nail 30 is inserted in the middle of the first implant nail 10, and the first end of the first connecting nail segment 31 is connected to the second implant nail 20. After the intramedullary nail mechanism is implanted, the intramedullary nail mechanism as a whole is under pressure, and the pressure is transmitted to the first end of the first connecting nail segment 31, so that the third implant nail 30 is under pressure, and the elastic buffer structure 40 between the second end of the first connecting nail segment 31 and the first end of the second connecting nail segment 32 is under pressure and is in a compressed state, and a damping force is generated on the first connecting nail segment 31. The second end of the first connecting nail segment 31 gradually approaches the first end of the second connecting nail segment 32, so that the overall length of the third implant nail 30 gradually decreases, and the pressure energy borne by the intramedullary nail mechanism is stored and dispersed by the elastic buffer structure 40, ensuring that the force of the intramedullary nail mechanism is balanced and the pressure borne is better dispersed, so that the load borne instantaneously by the intramedullary nail mechanism is slowed down and weakened by the retraction of the elastic buffer structure 40, thereby reducing the elastic modulus of the intramedullary nail mechanism and reducing stress shielding. This can effectively reconstruct the "Ward triangle" and realize a stable supporting intramedullary nail mechanism, which can not only effectively reposition and fix the patient's femoral head, but also reconstruct the "Ward triangle" at the femoral trochanteric site, and at the same time better disperse the stress on the femur, and avoid the intramedullary nail mechanism implanted in the femur from cutting out of the femur. Therefore, the technical solution of this embodiment can solve the problem of the intramedullary nail implanted in the femur cutting out of the femur in the related art.

[0041] It should be noted that the relative movement between the first connecting nail segment 31 and the second connecting nail segment 32 means that one of the first connecting nail segment 31 and the second connecting nail segment 32 is fixed and the other of the first connecting nail segment 31 and the second connecting nail segment 32 is movable; or both the first connecting nail segment 31 and the second connecting nail segment 32 are movable.

[0042] It should be noted that the middle part of the first implant nail 10 refers to the position between the first end of the first implant nail 10 and the second end of the first implant nail 10. The second implant nail 20 of this embodiment mainly supports the tension trabeculae in the femur, and the third implant nail 30 mainly supports the tensile trabeculae in the femur.

[0043] As Figure 3 and Figure 4 shown, during the relative movement of the first connecting pin segment 31 and the second connecting pin segment 32, in order to enable the first connecting pin segment 31 and the second connecting pin segment 32 to move smoothly, the second end of the first connecting pin segment 31 and the first end of the second connecting pin segment 32 are nested and matched. An inner hole 33 is provided at the first end of the second connecting pin segment 32, and the elastic buffer structure 40 is located within the inner hole 33. At the same time, the elastic buffer structure 40 located within the inner hole 33 can limit the elastic buffer structure 40 to prevent the elastic buffer structure 40 from detaching from the first end of the second connecting pin segment 32.

[0044] Of course, in an embodiment not shown in the figure, the second end of the first connecting pin segment and the first end of the second connecting pin segment are nested and matched. An inner hole may be provided at the second end of the first connecting pin segment, and the elastic buffer structure is located within the inner hole.

[0045] As Figures 3 to 11 shown, the inner hole 33 is provided at the first end of the second connecting pin segment 32, and the first connecting pin segment 31 passes through the inner hole 33. The second connecting pin segment 32 has a body portion and a buffer sleeve 42. The inner hole 33 is provided at the end of the body portion, the buffer sleeve 42 is provided within the inner hole 33, and the elastic buffer structure 40 is located between the second end of the first connecting pin segment 31 and the bottom wall of the inner hole 33. In this way, the second end of the first connecting pin segment 31 passes through the buffer sleeve 42. During the relative movement of the first connecting pin segment 31 and the second connecting pin segment 32, on the one hand, the buffer sleeve 42 can buffer the pressure borne by the first connecting pin segment 31, and on the other hand, the outer wall of the buffer sleeve 42 and the second end of the first connecting pin segment 31 can be in guiding cooperation, so that the second end of the first connecting pin segment 31 can move smoothly within the buffer sleeve 42, so that the second end of the first connecting pin segment 31 presses the elastic buffer structure 40 to smoothly transfer the pressure borne by the first connecting pin segment 31 to the elastic buffer structure 40.

[0046] As Figures 3 to 11 shown, in order to ensure the connection strength between the buffer sleeve 42 and the body portion, the buffer sleeve 42 is connected within the inner hole 33 by injection molding. Specifically, in order to ensure the connection effect of the buffer sleeve 42 being injection-molded within the inner hole 33, as Figure 10 and Figure 11 shown, connecting columns 37 are provided on the inner wall of the inner hole 33. During the process of the buffer sleeve 42 being injection-molded and connected within the inner hole 33, the connecting columns 37 melt to fill the gap in the radial direction between the buffer sleeve 42 and the inner hole 33, so as to firmly connect the buffer sleeve 42 and the body portion together.

[0047] In an embodiment not shown in the figure, the buffer sleeve is connected within the inner hole by welding, bonding or screwing.

[0048] AsFigures 1 to 11 As shown, in order to optimize the structural layout simultaneously and facilitate production, manufacturing, and installation, the elastic buffer structure 40 includes a spring 41. The buffer sleeve is made of biopolycarbonate polyurethane (PCU). The biopolycarbonate polyurethane material has good strength, and also has a certain degree of flexibility and elasticity, which can meet a certain amount of elastic deformation. By the deformation of the spring 41, the load instantaneously borne by the intramedullary nail mechanism is slowed down and weakened, enabling the third implanting nail 30 to provide a certain amount of elastic support, making the intramedullary nail mechanism elastic, effectively reducing the possibility of stress concentration in the intramedullary nail mechanism, and prolonging the service life of the intramedullary nail assembly. Specifically, the intramedullary nail mechanism is located at the proximal position of the femur 4, that is, the proximal femur.

[0049] Of course, in other embodiments, the elastic buffer structure includes a spring; or the material of the buffer sleeve is biopolycarbonate polyurethane.

[0050] As Figure 3 、 Figure 4 and Figure 8 shown, a first anti-rotation portion is provided at the second end of the first connecting nail segment 31, and a second anti-rotation portion is provided on the buffer sleeve 42. The first anti-rotation portion and the second anti-rotation portion are in anti-rotation cooperation. In this way, through the anti-rotation cooperation between the second anti-rotation portion and the first anti-rotation portion, when the second connecting nail segment 32 is screwed in, the first connecting nail segment 31 can rotate together with the second connecting nail segment 32, so that the third implanting nail 30 can be inserted through the middle of the first implanting nail 10, and the first end of the first connecting nail segment 31 is connected to the second implanting nail 20.

[0051] As Figure 3 、 Figure 4 and Figure 8 shown, the first anti-rotation portion includes an axial groove 35, and the second anti-rotation portion includes an axial rib 36 that is inserted and matched with the axial groove 35. In this way, when the first connecting nail segment 31 is stressed and moves relative to the second connecting nail segment 32, the axial rib 36 can move within the axial groove 35 to play a guiding role. At the same time, the groove side wall of the axial groove 35 contacts the side wall of the axial rib 36 to prevent the first connecting nail segment 31 from rotating relative to the second connecting nail segment 32.

[0052] As Figure 3 、 Figure 4 and Figure 8 shown, in order to enable the axial rib 36 to move within the axial groove 35, the axial dimension of the axial groove 35 is greater than the axial dimension of the axial rib 36. In this way, the axial rib 36 can slide smoothly along the axial groove 35 to ensure that the axial rib 36 has a certain moving distance.

[0053] As Figure 3 、 Figure 4 and Figure 8As shown, there are four axial grooves 35 circumferentially spaced along the second end of the first connecting nail segment 31, and four axial ribs 36 circumferentially spaced along the first end of the second connecting nail segment 32. The four axial grooves 35 and the four axial ribs 36 are arranged in one-to-one correspondence. This enables the second connecting nail segment 32 to twist the first connecting nail segment 31, such that the third implanting nail 30 has sufficient structural strength to ensure the structural stability of the third implanting nail 30. The number of the axial grooves 35 and the axial ribs 36 may not be limited to four, and may also be one, two, three, five or more.

[0054] As Figure 3 , Figure 4 , Figure 8 , Figures 12 to 14 shown, the third implanting nail 30 is inserted through the middle of the first implanting nail 10. Since the second implanting nail 20 is provided with a screw hole 23, the axis of the screw hole 23 is parallel to the axis of the first connecting nail segment 31. The first connecting nail segment 31 has a first threaded segment 312 that is threadedly engaged with the screw hole 23. In this way, the first end of the first connecting nail segment 31 is smoothly introduced into the screw hole 23 of the second implanting nail 20. As the third implanting nail 30 is continuously screwed in, the first threaded segment 312 can be threadedly connected in the screw hole 23, thereby connecting the first end of the first connecting nail segment 31 to the second implanting nail 20.

[0055] As Figures 1 to 6 , Figures 12 to 14 shown, the first connecting nail segment 31 includes a first threaded segment 312 and a first smooth rod segment 311 connected to the first threaded segment. In this way, the first threaded segment 312 is provided to facilitate screwing the first connecting nail segment 31 into the femur 4 and being threadedly connected in the screw hole 23, ensuring that the first connecting nail segment 31 has reliable implanting stability. The first smooth rod segment 311 is provided to reduce the resistance generated during the process of screwing the first connecting nail segment 31 into the femur 4, enabling the first connecting nail segment 31 to be smoothly screwed into the position connected to the screw hole 23.

[0056] As Figures 2 to 6 shown, the second connecting nail segment 32 includes a second threaded segment 321, a second smooth rod segment 322, and a third threaded segment 323 connected between the second threaded segment 321 and the second smooth rod segment 322. The outer diameter of the second threaded segment 321 is smaller than the outer diameter of the outer wall of the second smooth rod segment 322. An elastic buffer structure 40 is provided between the first smooth rod segment 311 and the second threaded segment 321. In this way, the third threaded segment 323 is provided to facilitate connecting the second connecting nail segment 32 to the first implanting nail 10. The second smooth rod segment 322 is provided to reduce the resistance generated during the process of screwing the second connecting nail segment 32 into the femur 4, enabling the second connecting nail segment 32 to be smoothly screwed into the position where the third threaded segment 323 is connected to the middle of the first implanting nail 10.

[0057] AsFigures 2 to 6 As shown, an operation hole 3221 is provided at one end of the second smooth rod section 322 away from the third threaded section 323. One end of the second smooth rod section 322 away from the third threaded section 323 forms the second end of the second connecting nail section 32. The provision of the operation hole 3221 facilitates driving the rotation of the second smooth rod section 322. The operation hole 3221 is preferably an internal hexagonal hole. In this way, an internal hexagonal wrench can be inserted into the operation hole 3221, and the second connecting nail section 32 can be driven to rotate, so that the third implanting nail 30 can achieve the reduction and compression effect on the fracture end.

[0058] As Figures 2 to 6 shown, an external thread 21 is provided at the first end of the second implanting nail 20. An operation groove 22 is provided at the second end of the second implanting nail 20. The first end of the first connecting nail section 31 is connected to the external thread 21. The provision of the external thread 21 facilitates screwing the second implanting nail 20 into the femur 4. The provision of the operation groove 22 makes the operation convenient. The first end of the first connecting nail section 31 is connected to the external thread 21, enabling bite locking and improving the supporting effect of the third implanting nail 30. After the second implanting nail 20 is implanted into the femur 4, the second end of the second implanting nail 20 can be exposed outside the outer wall of the femur 4, so that the operation groove 22 on the second end of the second implanting nail 20 can also be exposed outside the femur 4. The operation groove 22 can be driven by a screwdriver tool.

[0059] As Figure 3 and Figure 16 shown, the external thread 21 includes a rod body portion and screw teeth 216 provided on the rod body portion. A plurality of first grooves 201 are provided on the screw teeth 216. When the second implanting nail 20 is stressed, the external thread 21 of the second implanting nail 20 compresses the bone mass in the femur during screwing in. The screw teeth 216 provided with a plurality of first grooves 201 make the screw teeth 216 elastic and capable of generating micro-deformation, reducing the elastic modulus of the intramedullary locking nail assembly, enabling the screw teeth 216 to adapt to the surrounding bone mass, so that the bone mass around the screw teeth 216 can be inserted into the first grooves 201 for bite locking, reducing stress shielding, and effectively preventing further bone cutting and the second implanting nail 20 from piercing out of the femur.

[0060] As Figure 3 and Figure 16 shown, when the external thread 21 of the second implanting nail 20 is screwed in, it compresses the bone mass in the femur. Since the plurality of first grooves 201 on the same turn of screw teeth 216 are radially arranged, each first groove 201 is adapted to the embedded bone mass. The radially arranged plurality of first grooves 201 can bite more bone mass while reducing the elastic modulus of the second implanting nail 20, enabling the screw teeth 216 to effectively adapt to the surrounding bone mass.

[0061] It should be noted that the radial arrangement of multiple first grooves 201 means that the side walls of the multiple first grooves 201 can diverge in a straight line direction or in a curved line direction.

[0062] As Figure 3 and Figure 16 shown, the height of the thread 216 of the external thread 21 gradually decreases in the direction from away from the first implanting nail 10 to close to the first implanting nail 10. In this way, the part of the thread 216 of the external thread 21 away from the first implanting nail 10 has a higher thread and is embedded deeper into the bone mass, capable of biting the bone mass. At the same time, since the part of the thread 216 of the external thread 21 close to the first implanting nail 10 has a lower thread and higher strength, it can provide sufficient strength for the part of the thread 216 of the external thread 21 away from the first implanting nail 10.

[0063] As Figure 3 and Figure 16 shown, the rod body part includes a first rod body part 211 and a second rod body part 212. The first rod body part 211 has a smooth rod structure, and a plurality of second grooves 202 are provided in the part of the second rod body part 212 located between two adjacent threads 216. In this way, during the process of the external thread 21 of the second implanting nail 20 screwing in and compressing the bone mass in the femur, since the first rod body part 211 has a smooth rod structure, it can reduce the screwing-in resistance of the external thread 21, facilitating the screwing of the thread 216 on the first rod body part 211 into deeper bone mass. At the same time, it allows more bone mass to be embedded into the multiple first grooves 201 and the multiple second grooves 202, so that the elastic modulus of the second implanting nail 20 is closer to the elastic modulus of the bone mass, meeting the self-adaptive situation of the thread 216 and the surrounding bone mass, and further preventing bone cutting and the second implanting nail 20 from piercing out of the femur 4.

[0064] As Figures 2 to 6 and Figure 15As shown, the first implant nail 10 includes a first nail segment 11 and a second nail segment 12 connected to the first nail segment 11. The outer diameter of the first nail segment 11 is greater than that of the second nail segment 12. The second implant nail 20 is inserted through the first end of the first nail segment 11, and the first end and the second end of the second connecting nail segment 32 are respectively located on both sides of the second end of the first nail segment 11. In this way, the length of the second smooth rod segment 322 is relatively long, ensuring that after the third implant nail 30 is implanted into the femur 4, the second end of the second smooth rod segment 322 can be exposed outside the outer wall of the femur 4, so that the operation hole 3221 on the second smooth rod segment 322 can also be exposed outside the femur 4. And because the outer diameter of the first nail segment 11 is greater than that of the second nail segment 12, the first nail segment 11 has sufficient structural strength, facilitating the setting of the installation positions of the second implant nail 20 and the third implant nail 30 on the first nail segment 11. The intramedullary nail mechanism further includes a transverse nail 50 inserted through the second nail segment 12. The setting of the transverse nail 50 facilitates locking the second nail segment 12 into the femur and improves the overall structural stability of the intramedullary nail mechanism.

[0065] In this embodiment, the first implant nail 10, the second implant nail 20, the body part, the second threaded segment 321, the second smooth rod segment 322, and the third threaded segment 323 of the first connecting nail segment 31 and the second connecting nail segment 32 are preferably made of medical titanium alloy material. In this way, the medical titanium alloy material and the bio-polycarbonate polyurethane material can be connected by injection molding.

[0066] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, so it cannot be understood as a limitation on the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0067] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. can be used here to describe the spatial positional relationship of a device or feature shown in the figure with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0068] In addition, it should be noted that the use of terms such as "first", "second" etc. to limit components is only for the convenience of differentiating the corresponding components. Without additional statements, the above terms have no special meanings, and thus should not be construed as limiting the protection scope of the present invention.

[0069] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An intramedullary nail mechanism, characterized in that Comprising: A first implanting nail (10); A second implanting nail (20), passing through the first end of the first implanting nail (10) and being inclined relative to the first implanting nail (10); A third implanting nail (30), passing through the middle part of the first implanting nail (10) and being inclined relative to the first implanting nail (10), wherein, the third implanting nail (30) includes a first connecting nail segment (31) and a second connecting nail segment (32), the first connecting nail segment (31) and the second connecting nail segment (32) can move relative to each other, the first end of the first connecting nail segment (31) is connected to the second implanting nail (20), the second connecting nail segment (32) is arranged through the middle part of the first implanting nail (10), and an elastic buffer structure (40) is arranged between the second end of the first connecting nail segment (31) and the first end of the second connecting nail segment (32); The second end of the first connecting nail segment (31) and the first end of the second connecting nail segment (32) are nested and matched, an inner hole (33) is arranged at the second end of the first connecting nail segment (31) or the first end of the second connecting nail segment (32), and the elastic buffer structure (40) is located in the inner hole (33); The inner hole (33) is arranged at the first end of the second connecting nail segment (32), the first connecting nail segment (31) is arranged through the inner hole (33), the second connecting nail segment (32) has a body part and a buffer sleeve (42), the inner hole (33) is arranged at the end of the body part, the buffer sleeve (42) is arranged in the inner hole (33), and the elastic buffer structure (40) is located between the first connecting nail segment (31) and the bottom wall of the inner hole (33); The elastic buffer structure (40) includes a spring (41); the material of the buffer sleeve is bio-polycarbonate polyurethane; The buffer sleeve (42) is injection-molded and connected in the inner hole (33), connecting columns (37) are arranged on the inner wall of the inner hole (33), and during the process of injection-molding and connecting the buffer sleeve (42) in the inner hole (33), the connecting columns (37) melt to fill the radial gap between the buffer sleeve (42) and the inner hole (33); A first anti-rotation part is arranged at the second end of the first connecting nail segment (31), a second anti-rotation part is arranged on the buffer sleeve (42), and the first anti-rotation part and the second anti-rotation part are in anti-rotation cooperation.

2. The intramedullary nail mechanism according to claim 1, characterized in that, The first anti-rotation part includes an axial groove (35), and the second anti-rotation part includes an axial rib (36) inserted and matched with the axial groove (35).

3. The intramedullary nail mechanism according to claim 2, wherein, The axial dimension of the axial groove (35) is larger than the axial dimension of the axial rib (36).

4. The intramedullary nail mechanism according to claim 1, characterized in that, A screw hole (23) is arranged on the second implanting nail (20), the axis of the screw hole (23) is parallel to the axis of the first connecting nail segment (31), and the first connecting nail segment (31) has a first threaded segment (312) threadedly engaged with the screw hole (23).

5. The intramedullary nail mechanism according to claim 1, wherein, The first connecting nail segment (31) includes a first threaded segment (312) and a first smooth rod segment (311) connected to the first threaded segment; The second connecting nail segment (32) includes a second threaded segment (321), a second smooth rod segment (322), and a third threaded segment (323) connected between the second threaded segment (321) and the second smooth rod segment (322). The outer diameter of the second threaded segment (321) is smaller than the outer diameter of the outer wall of the second smooth rod segment (322). The elastic buffer structure (40) is arranged between the first smooth rod segment (311) and the second threaded segment (321). An operation hole (3221) is provided at one end of the second smooth rod segment (322) away from the third threaded segment (323). One end of the second smooth rod segment (322) away from the third threaded segment (323) forms the second end of the second connecting nail segment (32); An external thread (21) is provided at the first end of the second implanting nail (20), and an operation groove (22) is provided at the second end of the second implanting nail (20). The first end of the first connecting nail segment (31) is connected to the external thread (21); The first implanting nail (10) includes a first nail segment (11) and a second nail segment (12) connected to the first nail segment (11). The outer diameter of the first nail segment (11) is larger than the outer diameter of the second nail segment (12); The second implanting nail (20) is inserted through the first end of the first nail segment (11). The first end and the second end of the second connecting nail segment (32) are respectively located on both sides of the second end of the first nail segment (11); The intramedullary nail mechanism further includes a transverse nail (50) inserted through the second nail segment (12).

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