Intramedullary locking nail assembly

Abstract

The present invention provides an intramedullary locking nail assembly, comprising: a first locking nail; a second locking nail, disposed through a first end of the first locking nail, the axis of the second locking nail being arranged at an angle relative to the axis of the first locking nail; and a third locking nail, disposed through a middle portion of the first locking nail, the axis of the third locking nail being arranged at an angle relative to the axis of the first locking nail, the third locking nail supporting the second locking nail, wherein the second locking nail includes a threaded section, and the third locking nail supports the threaded section, the threaded section including a shank portion and a screw thread disposed on the shank portion, the screw thread being provided with a plurality of first grooves. The technical solution of the present application effectively solves the problem of intramedullary nails protruding outside the femur in related technologies.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to an intramedullary locking nail assembly. Background Art

[0002] Intertrochanteric fractures are typically treated with intramedullary nailing. Currently, intramedullary nailing forms a lever-like structure. However, the stability of this lever-like structure is significantly inferior to the triangular support structure formed by normal bone tissue. Because intramedullary nails are rigid and made of metal, the intramedullary nail system is prone to stress shielding during compression due to the high elastic modulus of the femoral system, which can lead to internal fixation failure or nail protrusion outside the femur. Summary of the Invention

[0003] The main purpose of the present invention is to provide an intramedullary locking nail assembly to solve the problem of intramedullary nail protruding out of the femur in the related art.

[0004] To achieve the above-mentioned objectives, the present invention provides an intramedullary locking nail assembly, comprising: a first locking nail; a second locking nail, which is disposed through a first end of the first locking nail, and the axis of the second locking nail is arranged obliquely relative to the axis of the first locking nail; a third locking nail, which is disposed through a middle portion of the first locking nail, and the axis of the third locking nail is arranged obliquely relative to the axis of the first locking nail, and the third locking nail supports the second locking nail, wherein the second locking nail includes a threaded section, the third locking nail supports the threaded section, the threaded section includes a rod body and screw threads provided on the rod body, and the screw threads are provided with a plurality of first grooves.

[0005] Furthermore, the plurality of first grooves on the same circle of threads are arranged radially.

[0006] Furthermore, the height of the thread of the threaded segment gradually decreases from away from the first locking pin to close to the first locking pin.

[0007] Furthermore, the rod body portion includes a first rod body portion and a second rod body portion, the first rod body portion is a polished rod structure, and a portion of the second rod body portion located between two adjacent screw threads is provided with a plurality of second grooves.

[0008] Furthermore, the axial dimension of the first rod body portion is larger than the axial dimension of the second rod body portion, a first stop groove is provided on the first rod body portion, and a second stop groove connected to the first stop groove is provided on the second rod body portion, and the end of the third locking pin is located in the first stop groove and the second stop groove.

[0009] Furthermore, the end of the third locking nail has a flexible portion; and / or a first flexible layer is provided on the threaded segment.

[0010] Furthermore, a first inclined hole for the third locking nail to pass through is provided in the middle of the first locking nail, the third locking nail includes a first external thread segment, and the first inclined hole is provided with an internal thread that matches the first external thread segment in a conical shape.

[0011] Furthermore, a second axial through hole is provided in the first locking nail, the first inclined hole is connected to the second axial through hole, the second axial through hole separates the first inclined hole to form a first hole section and a second hole section, the third locking nail also includes a first polished rod section and a second polished rod section located at both ends of the first external thread section, the diameter of the second polished rod section is larger than the diameter of the first polished rod section, the first polished rod section passes through the first hole section, and the internal thread is provided on the second hole section; the third locking nail also includes a second external threaded section supporting the second locking nail, and the first polished rod section is located between the second external threaded section and the first external threaded section.

[0012] Furthermore, the first end of the first locking pin is provided with a second inclined hole for the second locking pin to pass through, the angle between the axis of the second inclined hole and the axis of the first locking pin is greater than the angle between the axis of the first inclined hole and the axis of the first locking pin, and a second flexible layer is provided between the second locking pin and the second inclined hole.

[0013] Furthermore, the second inclined hole is a stepped hole, and the second locking nail also includes a third polished rod segment connected to the threaded segment, the third polished rod segment passes through the second inclined hole and has a stepped segment that cooperates with the second inclined hole; an operating groove is provided at one end of the third polished rod segment away from the threaded segment; an operating hole is provided at one end of the third locking nail away from the first external threaded segment; the first locking nail includes a fourth polished rod segment and a fifth polished rod segment connected to the fourth polished rod segment, the outer diameter of the fourth polished rod segment is greater than the outer diameter of the fifth polished rod segment, the third polished rod segment is passed through the first end of the fourth polished rod segment, and the end of the third locking nail provided with the operating hole is located on one side of the second end of the fourth polished rod segment; the intramedullary locking nail assembly also includes a transverse nail passed through the fifth polished rod segment.

[0014] According to the technical solution of the present invention, an intramedullary locking nail assembly includes a first locking nail, a second locking nail, and a third locking nail. The second locking nail is inserted through the first end of the first locking nail, with its axis inclined relative to the axis of the first locking nail. The third locking nail is inserted through the middle of the first locking nail, with its axis inclined relative to the axis of the first locking nail. The third locking nail supports the second locking nail, defining a triangular area between the first, second, and third locking nails. The second locking nail includes a threaded section, and the third locking nail supports the threaded section. The threaded section includes a shaft and screw threads disposed on the shaft, each of which has a plurality of first grooves. During implantation of the intramedullary locking nail assembly into the femur, the first locking nail is driven in, the second locking nail is inserted through the first end of the first locking nail, and the second locking nail applies pressure to the fractured end. The third locking nail is inserted through the middle of the first locking nail, supporting the second locking nail. After implantation, the intramedullary locking nail assembly is subjected to pressure as a whole. When the second locking nail is subjected to force, the threaded section of the second locking nail compresses the bone within the femur as it is screwed in. The screw thread with multiple first grooves makes the screw thread elastic and can produce micro-deformation, which reduces the elastic modulus of the intramedullary locking nail assembly, allowing the screw thread to adapt to the surrounding bone, so that the bone around the screw thread is inserted into the first groove for occlusal locking, reducing stress shielding and effectively preventing further bone cutting and the second locking nail from protruding out of the femur. Therefore, the technical solution of this application can solve the problem of intramedullary nail protrusion outside the femur in related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0016] Figure 1 A perspective schematic diagram showing an intramedullary locking nail assembly according to an embodiment of the present invention being implanted into a femur;

[0017] Figure 2 Shown Figure 1 A schematic front view of an intramedullary locking nail assembly;

[0018] Figure 3 Shown Figure 1 A schematic diagram of the three-dimensional structure of the intramedullary locking nail assembly;

[0019] Figure 4 Shown Figure 3 A schematic cross-sectional view of an intramedullary locking nail assembly;

[0020] Figure 5 Shown Figure 4 An enlarged schematic diagram of point A of the intramedullary locking nail assembly;

[0021] Figure 6 Shown Figure 4 An enlarged schematic diagram of point B of the intramedullary locking nail assembly;

[0022] Figure 7 Shown Figure 4 An enlarged schematic diagram of position C of the intramedullary locking nail assembly;

[0023] Figure 8 Shown Figure 1 A schematic diagram of the three-dimensional structure of the second locking nail of the intramedullary locking nail assembly;

[0024] Figure 9 Shown Figure 8 A schematic front view of a second locking pin;

[0025] Figure 10 Shown Figure 9 a schematic cross-sectional view of a second locking pin;

[0026] Figure 11 Shown Figure 1 A schematic cross-sectional view of a third locking nail of the intramedullary locking nail assembly;

[0027] Figure 12 Shown Figure 1 A schematic front view of a first locking nail of an intramedullary locking nail assembly;

[0028] Figure 13 Shown Figure 12 a schematic cross-sectional view of a first locking pin;

[0029] Figure 14 Shown Figure 1 A schematic cross-sectional view of a second locking nail of the intramedullary locking nail assembly;

[0030] Figure 15 Shown Figure 1 Schematic diagram of the exploded structure of the second locking nail of the intramedullary locking nail assembly.

[0031] The above drawings include the following reference numerals:

[0032] 4. Femur; 10. First locking nail; 11. First inclined hole; 111. First hole segment; 112. Second hole segment; 12. Second inclined hole; 13. Fourth polished rod segment; 14. Fifth polished rod segment; 20. Second locking nail; 21. Threaded segment; 211. First rod portion; 212. Second rod portion; 213. First stop groove; 214. Second stop groove; 215. First flexible layer; 216. Screw thread; 22. First groove; 23. Second groove; 24 , second flexible layer; 25, third polished rod section; 251, operating groove; 30, third locking pin; 31, flexible portion; 32, operating hole; 33, first external threaded section; 34, first polished rod section; 341, first pin section; 342, second pin section; 35, second polished rod section; 36, second external threaded section; 40, airbag; 50, transverse pin; 61, accommodating tube; 62, abutting top; 63, axial groove; 64, axial rib; 65, limiting groove section; 66, limiting ring. DETAILED DESCRIPTION

[0033] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only 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 is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, 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 "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0035] Unless otherwise specifically stated, the relative arrangement of the parts and steps, the numerical expressions and the numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values should be interpreted as being merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0036] like Figures 1 to 8 As shown, the intramedullary locking nail assembly of this embodiment includes: a first locking nail 10, a second locking nail 20, and a third locking nail 30. The second locking nail 20 is disposed through the first end of the first locking nail 10, with the axis of the second locking nail 20 tilted relative to the axis of the first locking nail 10. The third locking nail 30 is disposed through the middle of the first locking nail 10, with the axis of the third locking nail 30 tilted relative to the axis of the first locking nail 10. The third locking nail 30 supports the second locking nail 20, thereby defining a triangular area between the first locking nail 10, the second locking nail 20, and the third locking nail 30. The second locking nail 20 has a first axial through-hole formed therein. The second locking nail 20 includes a threaded section 21, and the third locking nail 30 supports the threaded section 21. The threaded section 21 includes a shank portion and a screw thread 216 disposed thereon. The screw thread 216 has a plurality of first grooves 22 formed therein.

[0037] Using the technical solution of this embodiment, the threaded segment 21 includes a shank portion and screw threads 216 disposed thereon. The screw threads 216 are provided with a plurality of first grooves 22. During implantation of the intramedullary locking nail assembly into the femur, the first locking nail 10 is driven in. The second locking nail 20 is passed through the first end of the first locking nail 10 along a guidewire within the first axial through-hole. The second locking nail 20 applies pressure to the fractured end. The third locking nail 30 is passed through the middle of the first locking nail 10, supporting the second locking nail 20. After implantation, the intramedullary locking nail assembly is subjected to pressure as a whole. When the second locking nail 20 is subjected to force, the threaded section 21 of the second locking nail 20 compresses the bone within the femur as it is screwed in. The screw thread 216, which is provided with multiple first grooves 22, is elastic and can produce slight deformation. This reduces the elastic modulus of the intramedullary locking nail assembly, allowing the screw thread 216 to adapt to the surrounding bone, allowing the bone surrounding the screw thread 216 to be inserted into the first grooves 22 for occlusal locking. This reduces stress shielding and effectively prevents further bone cutting and the second locking nail 20 from protruding out of the femur. Therefore, the technical solution of this embodiment can solve the problem of intramedullary nail protrusion into the femur in related technologies.

[0038] It should be noted that the middle portion of first locking nail 10 refers to the position between the first end and the second end of first locking nail 10. In this embodiment, second locking nail 20 primarily supports the tension trabeculae in the femur, and third locking nail 30 primarily supports the tensile trabeculae in the femur.

[0039] like Figures 8 to 10 As shown, the threaded section 21 of the second locking nail 20 compresses the bone in the femur when it is screwed in. Since the multiple first grooves 22 located on the same circle of screw threads 216 are arranged radially, each first groove 22 is adapted to the embedded bone. The radial arrangement of the multiple first grooves 22 can engage more bone while reducing the elastic modulus of the second locking nail 20, so that the screw threads 216 can effectively adapt to the surrounding bone.

[0040] It should be noted that the radial arrangement of the plurality of first trenches 22 means that the sidewalls of the plurality of first trenches 22 may diverge along a straight line direction or a curved line direction.

[0041] like Figure 4 、 Figures 8 to 10As shown, the height of the screw thread 216 of the threaded segment 21 gradually decreases from away from the first locking nail 10 to closer to the first locking nail 10. Thus, the screw thread 216 of the threaded segment 21 is higher in the portion away from the first locking nail 10, embedding deeper into the bone and providing a better grip. Furthermore, since the screw thread 216 of the threaded segment 21 is lower and stronger in the portion closer to the first locking nail 10, sufficient strength is provided for the portion farther away from the first locking nail 10.

[0042] like Figure 4 、 Figures 8 to 10 As shown, the rod portion includes a first rod portion 211 and a second rod portion 212. The first rod portion 211 is a polished rod structure, and the portion of the second rod portion 212 located between two adjacent screw threads 216 is provided with a plurality of second grooves 23. Thus, when the threaded segment 21 of the second locking nail 20 is screwed into the femur, the polished structure of the first rod portion 211 can reduce the screwing resistance of the threaded segment 211, facilitates screwing of the screw threads 216 on the first rod portion 211 deeper into the bone, and allows more bone to be embedded in the plurality of first grooves 22 and the plurality of second grooves 23. This allows the elastic modulus of the second locking nail 20 to be closer to the elastic modulus of the bone, satisfies the adaptive condition of the screw threads 216 and the surrounding bone, and further prevents bone cutting and the second locking nail 20 from passing out of the femur 4.

[0043] Specifically, the side walls of the plurality of second grooves 23 located on the same circle of thread teeth 216 are parallel to the axis of the rod body.

[0044] like Figure 4 、 Figures 8 to 10 As shown, to better enable the screw thread 216 on the rod body to engage and lock, the axial dimension of the first rod body 211 is greater than the axial dimension of the second rod body 212. A first stop groove 213 is provided on the first rod body 211, and a second stop groove 214 is provided on the second rod body 212, which communicates with the first stop groove 213. The end of the third locking pin 30 is located within the first and second stop grooves 213, 214. The first and second stop grooves 213, 214 respectively constrain the end of the third locking pin 30 on both sides, preventing the third locking pin 30 from misaligning when supporting the second locking pin 20, thereby ensuring that the third locking pin 30 is securely in its supporting position.

[0045] like Figure 3 、 Figure 4 、 Figures 8 to 10As shown, to reduce the load exerted by the second locking pin 20 on the third locking pin 30, the end of the third locking pin 30 is provided with a flexible portion 31. The flexible portion 31 provides a certain buffering effect. To further reduce the load exerted by the second locking pin 20 on the third locking pin 30, a first flexible layer 215 is provided on the threaded section 21. The first flexible layer 215 also provides a certain buffering effect. Thus, the pressure energy exerted on the intramedullary locking pin assembly is stored and dispersed by the flexible portion 31 and the first flexible layer 215. The compression of the flexible portion 31 and the first flexible layer 215 mitigates and reduces the instantaneous load exerted on the intramedullary locking pin assembly, ensuring that the intramedullary locking pin assembly does not experience transient stress concentration, thereby improving the implant stability of the intramedullary locking pin assembly and effectively preventing the second locking pin 20 from protruding. Furthermore, the provision of the flexible portion 31 and the first flexible layer 215 effectively reduces the generation of metal debris particles caused by metal rigidity collisions, thereby reducing the probability of postoperative bone resorption and inflammatory reactions.

[0046] In an embodiment not shown in the figures, the end of the third locking nail has a flexible portion, or a first flexible layer is provided on the threaded section.

[0047] like Figures 4 to 7 and Figure 11 As shown, the center of the first locking pin 10 is provided with a first inclined hole 11 for the third locking pin 30 to pass through. The third locking pin 30 includes a first externally threaded section 33, and the first inclined hole 11 is provided with an internal thread that conically mates with the first externally threaded section 33. Thus, the third locking pin 30 passes obliquely upward along the path formed by the first inclined hole 11 to the center of the first locking pin 10, allowing the end of the third locking pin 30 to smoothly reach the first stop groove 213 and the second stop groove 214, effectively supporting the second locking pin 20. Furthermore, the first externally threaded section 33 conically mates with the internal thread of the first inclined hole 11, securely locking the third locking pin 30 in the center of the first locking pin 10 and preventing it from retreating. Specifically, the internal thread is an internally tapered thread, while the first externally threaded section 33 is an externally tapered thread.

[0048] like Figures 4 to 7 and Figure 11As shown, a second axial through-hole is provided in the first locking nail 10, and the first inclined hole 11 is connected to the second axial through-hole. The first locking nail 10 is driven into the femur 4 along the guide wire in the second axial through-hole. The second axial through-hole divides the first inclined hole 11 to form a first hole section 111 and a second hole section 112. The third locking nail 30 also includes a first polished rod section 34 and a second polished rod section 35 located at both ends of the first externally threaded section 33. To form a tapered shape for the first externally threaded section 33, the diameter of the second polished rod section 35 is larger than the diameter of the first polished rod section 34. The first polished rod section 34 passes through the first hole section 111, and the internal thread is provided in the second hole section 112. The above-mentioned first hole section 111 is a smooth hole. In this way, the first hole section 111 can smoothly guide the third locking nail 30 so that the third locking nail 30 can be smoothly implanted into the femur 4. At the same time, when the end of the third locking nail 30 contacts the bottom wall of the first stop groove 213 and the second stop groove 214, the first external thread section 33 is screwed with the internal thread on the second hole section 112, thereby achieving implantation and reliably locking the third locking nail 30 in the middle of the first locking nail 10.

[0049] like Figures 4 to 7 and Figure 11 As shown, the third locking nail 30 also includes a second externally threaded section 36 that supports the second locking nail 20. The first polished rod section 34 is located between the second externally threaded section 36 and the first externally threaded section 33. The arrangement of the second externally threaded section 36 ensures that the end of the third locking nail 30 is in line contact with the bottom walls of the first and second stop grooves 213, 214. When the second locking nail is deformed by downward pressure, the flexible portion on the end of the third locking nail provides a certain degree of cushioning. The arrangement of the first polished rod section 34 reduces the resistance generated during the screwing of the third locking nail 30 into the femur, ensuring smooth insertion of the third locking nail 30 into the femur 4.

[0050] like Figure 4 、 Figure 14 and Figure 15As shown, the first polished rod segment 34 includes a first nail segment 341 and a second nail segment 342 that movably engages with the first nail segment 341. An airbag 40 is disposed between the second end of the first nail segment 341 and the first end of the second nail segment 342. After implantation of the intramedullary locking nail assembly, the first end of the first nail segment 341 is compressed, and the airbag 40 between the second end of the first nail segment 341 and the first end of the second nail segment 342 is compressed. The second end of the first nail segment 341 gradually approaches the first end of the second nail segment 342, causing the overall length of the third locking nail 30 to gradually decrease. The pressure energy borne by the intramedullary locking nail assembly is stored and dispersed by the airbag 40. The deformation of the airbag 40 slows down and reduces the instantaneous load borne by the intramedullary locking nail assembly, thereby lowering the elastic modulus of the intramedullary locking nail assembly and reducing stress shielding. This effectively reconstructs the "ward triangle" and achieves a stable, supported intramedullary locking nail assembly. This effectively reduces and fixes the patient's femoral head 4, reconstructs the "ward triangle" at the trochanteric region of the femur 4, and effectively distributes stress on the femur 4, preventing the intramedullary locking nail assembly implanted within the femur 4 from being cut outside the femur 4. In this embodiment, the airbag 40 is filled with gas and is preferably ellipsoidal in shape, similar to a capsule. The outer wall of the airbag 40 is constructed from a high-toughness material. The deformation of the airbag 40 mitigates and reduces the instantaneous load on the intramedullary locking nail assembly, allowing the third locking nail 30 to provide a certain degree of elastic support. This imparts elasticity to the intramedullary locking nail assembly, effectively reducing the potential for stress concentration within the intramedullary locking nail assembly and extending its service life. Specifically, the intramedullary locking nail assembly is located at the proximal end of the femur 4. The aforementioned high-toughness material is preferably latex.

[0051] like Figure 4 、 Figure 14 and Figure 15 As shown, the second end of the first nail segment 341 is provided with a housing tube 61 for accommodating the airbag 40. The first end of the second nail segment 342 is provided with an abutment portion 62 that opposes the opening of the housing tube 61 and compresses against the airbag 40. The housing tube 61 facilitates the third locking nail 30 to accommodate the airbag 40, thereby making the third locking nail 30 compact. Simultaneously, the abutment portion 62 compresses the airbag 40, allowing it to switch from an expanded state to a compressed state. The abutment portion 62 may be a platform or a post.

[0052] like Figure 4 、 Figure 14 and Figure 15As shown, during the process of inserting the third locking nail 30 into the middle portion of the first locking nail 10 and screwing it into the femur, to prevent relative rotation between the second nail segment 342 and the first nail segment 341, a first rotation stop is provided on the outer wall of the accommodating tube 61. A second rotation stop is also provided on the first ends of the first and second nail segments 341, 342, located on the side of the abutment portion 62. The second rotation stop engages with the first rotation stop. Thus, due to the rotational engagement of the second rotation stop with the first rotation stop, the first nail segment 341 can rotate along with the second nail segment 342 when the second nail segment 342 is screwed in, allowing the third locking nail 30 to be inserted into the middle portion of the first locking nail 10.

[0053] like Figure 4 、 Figure 14 and Figure 15 As shown, the first anti-rotation portion includes an axial groove 63, and the second anti-rotation portion includes an axial rib 64 that is plugged into the axial groove 63. In this way, when the first nail segment 341 is subjected to force and moves relative to the second nail segment 342, the axial rib 64 can move in the axial groove 63 to play a guiding role. At the same time, the side walls of the axial groove 63 contact the side walls of the axial rib 64 to prevent the first nail segment 341 from rotating relative to the second nail segment 342.

[0054] like Figure 4 、 Figure 14 and Figure 15 As shown, four axial grooves 63 are spaced apart along the circumference of the accommodating tube 61, and four axial ribs 64 are spaced apart along the circumference of the first end of the second nail segment 342. The four axial grooves 63 correspond to the four axial ribs 64. This ensures that when the second nail segment 342 twists the first nail segment 341, the third locking nail 30 has sufficient structural strength, ensuring the structural stability of the third locking nail 30. The number of axial grooves 63 and axial ribs 64 is not limited to four, and can also be one, two, three, five, or more.

[0055] like Figure 4 、 Figure 14 and Figure 15As shown, the accommodating tube 61 is disposed on the second end of the first nail segment 341, a limiting groove section 65 is provided between the accommodating tube 61 and the second end of the first nail segment 341, an axial rib 64 is disposed on the first end of the second nail segment 342, and a limiting ring 66 is provided at the end of the axial rib 64. The limiting ring 66 is disposed within the limiting groove section 65 and is movable along the axial direction of the first nail segment 341 to enable the abutting portion 62 to squeeze or release the airbag 40. The limiting ring 66 is located within the limiting groove section 65 and can limit the range of movement of the first nail segment 341 relative to the second nail segment 342, thereby preventing the first and second nail segments 341 and 342 from disengaging. Specifically, during the movement of the first nail segment 341 relative to the second nail segment 342, when the limiting ring 66 abuts against the side wall of the limiting groove segment 65 close to the first end of the first nail segment 341, the top portion 62 squeezes the airbag 40 so that the airbag 40 can be in a compressed state. When the limiting ring 66 abuts against the side wall of the limiting groove segment 65 away from the first end of the first nail segment 341, the top portion 62 releases the airbag 40 so that the airbag 40 can be in an expanded state.

[0056] To facilitate connection, processing and assembly, the limiting ring 66 and the axial rib 64 are separate structures and are connected by welding, bonding or screwing, and the accommodating cylinder 61 and the first nail segment 341 are separate structures and are connected by welding, bonding or screwing.

[0057] like Figures 4 to 7 and Figure 13 As shown, the first end of the first locking nail 10 is provided with a second inclined hole 12 for passing the second locking nail 20. The angle between the axis of the second inclined hole 12 and the axis of the first locking nail 10 is greater than the angle between the axis of the first inclined hole 11 and the axis of the first locking nail 10. Thus, the second inclined hole 12 is slightly angled upward, ensuring that the second locking nail 20 is implanted close to the upper wall of the femur 4 through the second inclined hole 12. The first inclined hole 11 is more inclined upward, ensuring that the third locking nail 30 is implanted close to the medial wall of the femur 4.

[0058] Because the first locking pin 10 and the second locking pin 20 are in rigid contact, a second flexible layer 24 is positioned between the second locking pin 20 and the second inclined hole 12 to prevent rigid collisions. This second flexible layer 24 can deform under pressure, effectively preventing rigid collisions and reducing the generation of metal debris particles caused by metal-to-metal collisions, thereby reducing the likelihood of postoperative bone resorption and inflammatory reactions. The second flexible layer 24 is embedded into the second inclined hole 12 via injection molding to form a flexible gasket.

[0059] like Figures 4 to 7 and Figure 13As shown, the second inclined hole 12 is a stepped hole. The second locking nail 20 also includes a third polished rod segment 25 connected to the threaded segment 21. The third polished rod segment 25 passes through the second inclined hole 12 and has a stepped segment that mates with the second inclined hole 12. Thus, as the second locking nail 20 is screwed into the femur, the stepped segment engages with the stepped hole stop, preventing further screwing of the second locking nail 20 and providing a position limiter. The provision of the threaded segment 21 facilitates the screwing of the second locking nail 20 into the femur 4.

[0060] like Figures 1 to 4 As shown, an operating groove 251 is provided on the end of the third polished rod segment 25 away from the threaded segment 21. The provision of the operating groove 251 facilitates operation. After the second locking nail 20 is implanted in the femur 4, the second end of the second locking nail 20 can be exposed on the lateral wall of the femur 4, allowing the operating groove 251 on the second end of the second locking nail 20 to also be exposed outside the femur 4. The operating groove 251 can be driven using a screwdriver.

[0061] like Figures 1 to 4 As shown, an operating hole 32 is provided at one end of the third locking nail 30 away from the first externally threaded section 33. The provision of the operating hole 32 facilitates driving the third locking nail 30 for rotation. The operating hole 32 is preferably a hexagonal hole. In this way, an hexagonal wrench can be inserted into the operating hole 32 to drive the third locking nail 30 for rotation, so that the third locking nail 30 can achieve the effect of reducing and pressurizing the fracture end.

[0062] like Figures 1 to 4 As shown, the first locking nail 10 includes a fourth polished rod segment 13 and a fifth polished rod segment 14 connected to the fourth polished rod segment 13. The outer diameter of the fourth polished rod segment 13 is larger than that of the fifth polished rod segment 14. The third polished rod segment 25 is inserted through the first end of the fourth polished rod segment 13, and the end of the third locking nail 30, which is provided with the operation hole 32, is located to one side of the second end of the fourth polished rod segment 13. This ensures that the third locking nail 30 is relatively long, ensuring that after the third locking nail 30 is implanted in the femur 4, the bottom end of the third locking nail 30 is exposed on the outer wall of the femur 4, so that the operation hole 32 at the bottom end of the third locking nail 30 is also exposed outside the femur 4.

[0063] like Figures 1 to 4 、 Figure 12 and Figure 13 As shown, the intramedullary locking nail assembly further includes a transverse nail 50 passing through the fifth polished rod segment 14. The provision of the transverse nail 50 facilitates locking the fifth polished rod segment 14 into the femur, thereby improving the overall structural stability of the intramedullary locking nail assembly.

[0064] In this embodiment, the first locking pin 10, second locking pin 20, and third locking pin 30 are preferably made of a medical titanium alloy. The first flexible layer 215 and second flexible layer 24 are preferably made of a bio-based polycarbonate polyurethane (PCU) material. PCU offers excellent strength, flexibility, and elasticity, allowing for a certain degree of elastic deformation. The flexible portion 31 is preferably made of polyetheretherketone (PEEK), a plastic material with excellent biocompatibility and an elastic modulus close to that of human bone. The flexible portion 31 and third locking pin 30 can be connected by injection molding. The first flexible layer 215 and second locking pin 20 can also be connected by injection molding.

[0065] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0066] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0067] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0068] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An intramedullary locking nail assembly, characterized in that: include: A first locking pin (10), wherein a second axial through hole is provided in the first locking pin (10); A second locking pin (20) is passed through the first end of the first locking pin (10), and the axis of the second locking pin (20) is tilted relative to the axis of the first locking pin (10); A third locking pin (30) is provided through the middle of the first locking pin (10), the axis of the third locking pin (30) is tilted relative to the axis of the first locking pin (10), and the third locking pin (30) supports the second locking pin (20). The second locking pin (20) includes a threaded section (21), the third locking pin (30) supports the threaded section (21), the threaded section (21) includes a rod portion and screw threads (216) provided on the rod portion, and the screw threads (216) are provided with a plurality of first grooves (22); A first inclined hole (11) for the third locking nail (30) to pass through is provided in the middle of the first locking nail (10), the first inclined hole (11) is communicated with the second axial through hole, the second axial through hole separates the first inclined hole (11) to form a first hole section (111) and a second hole section (112), the third locking nail (30) includes a first external thread section (33), the first inclined hole (11) is provided with an internal thread that matches the first external thread section (33) in a conical shape, the internal thread is an internal tapered thread, the first external thread section (33) is an external tapered thread, the internal thread is provided on the second hole section (112), and the first hole section (111) is a smooth hole; The third locking nail (30) further comprises a first polished rod segment (34) and a second polished rod segment (35) located at both ends of the first external thread segment (33); the diameter of the second polished rod segment (35) is larger than the diameter of the first polished rod segment (34); the first polished rod segment (34) passes through the first hole segment (111); the first polished rod segment (34) comprises a first nail segment (341) and a second nail segment (342) movably engaged with the first nail segment (341); an air bag (40) is provided between the second end of the first nail segment (341) and the first end of the second nail segment (342); The second end of the first nail segment (341) is provided with a receiving tube (61) for receiving the airbag (40), and the first end of the second nail segment (342) is provided with a contact portion (62) that is opposite to the mouth of the receiving tube (61) and is pressed and matched with the airbag (40); A first anti-rotation portion is provided on the outer wall of the accommodating cylinder (61), and a second anti-rotation portion is further provided on the first end of the second nail segment (342) and located on the side of the abutting top portion (62), wherein the second anti-rotation portion is anti-rotationally engaged with the first anti-rotation portion; The first anti-rotation portion includes an axial groove (63), and the second anti-rotation portion includes an axial rib (64) plug-fitted with the axial groove (63); The four axial grooves (63) are arranged at intervals along the circumference of the accommodating cylinder (61), and the four axial ribs (64) are arranged at intervals along the circumference of the first end of the second nail segment (342). The four axial grooves (63) and the four axial ribs (64) are arranged in a one-to-one correspondence; The accommodating cylinder (61) is arranged on the second end of the first nail segment (341), and a limiting groove segment (65) is arranged between the accommodating cylinder (61) and the second end of the first nail segment (341). The axial rib (64) is arranged on the first end of the second nail segment (342), and a limiting ring (66) is provided at the end of the axial rib (64). The limiting ring (66) is arranged in the limiting groove segment (65) along the axial direction of the first nail segment (341) so as to allow the abutting top (62) to squeeze or release the airbag (40).

2. The intramedullary locking nail assembly according to claim 1, characterized in that: The plurality of first grooves (22) located on the same circle of threaded teeth (216) are arranged radially.

3. The intramedullary locking nail assembly according to claim 1, characterized in that: The height of the thread (216) of the threaded section (21) gradually decreases in a direction from away from the first locking pin (10) to closer to the first locking pin (10).

4. The intramedullary locking nail assembly according to claim 1, characterized in that: The rod body portion comprises a first rod body portion (211) and a second rod body portion (212); the first rod body portion (211) is a bare rod structure; a portion of the second rod body portion (212) located between two adjacent screw threads (216) is provided with a plurality of second grooves (23).

5. The intramedullary locking nail assembly according to claim 4, characterized in that: The axial dimension of the first rod body portion (211) is greater than the axial dimension of the second rod body portion (212); a first stop groove (213) is provided on the first rod body portion (211); a second stop groove (214) communicating with the first stop groove (213) is provided on the second rod body portion (212); and the end of the third locking pin (30) is located in the first stop groove (213) and the second stop groove (214).

6. The intramedullary locking nail assembly according to claim 1, characterized in that: The end of the third locking nail (30) has a flexible portion (31); and / or a first flexible layer (215) is provided on the threaded section (21).

7. The intramedullary locking nail assembly according to claim 1, characterized in that: The third locking nail (30) further comprises a second external thread segment (36) supporting the second locking nail (20), and the first polished rod segment (34) is located between the second external thread segment (36) and the first external thread segment (33).

8. The intramedullary locking nail assembly according to claim 1, characterized in that: A second inclined hole (12) is provided at the first end of the first locking pin (10) for the second locking pin (20) to pass through, the angle between the axis of the second inclined hole (12) and the axis of the first locking pin (10) being greater than the angle between the axis of the first inclined hole (11) and the axis of the first locking pin (10), and a second flexible layer (24) is provided between the second locking pin (20) and the second inclined hole (12).

9. The intramedullary locking nail assembly according to claim 8, characterized in that: The second inclined hole (12) is a stepped hole, and the second locking nail (20) further includes a third polished rod segment (25) connected to the threaded segment (21), the third polished rod segment (25) passing through the second inclined hole (12) and having a stepped segment that matches the second inclined hole (12); An operating groove (251) is provided at one end of the third polished rod segment (25) away from the threaded segment (21); An operating hole (32) is provided at one end of the third locking nail (30) away from the first external thread section (33); The first locking pin (10) includes a fourth polished rod segment (13) and a fifth polished rod segment (14) connected to the fourth polished rod segment (13), the outer diameter of the fourth polished rod segment (13) is larger than the outer diameter of the fifth polished rod segment (14), the third polished rod segment (25) is passed through the first end of the fourth polished rod segment (13), and the end of the third locking pin (30) provided with the operating hole (32) is located on one side of the second end of the fourth polished rod segment (13); The intramedullary locking nail assembly further comprises a transverse nail (50) penetrating the fifth polished rod segment (14).

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