Metallic additive manufacturing matching long bone implant prosthesis

Abstract

The application discloses a metal additive manufacturing matching type long bone implant prosthesis and relates to the technical field of implant prostheses.The implant prosthesis comprises a main body, one end of the main body is fixedly connected with an intramedullary fixation rod, one side of the intramedullary fixation rod is uniformly provided with a positioning groove, the other side of the intramedullary fixation rod is provided with a screw hole, the other end of the main body is provided with a matching interface, the outside of the intramedullary fixation rod is sleeved with a 3D printing porous structure, one side of the 3D printing porous structure is mounted on the outer wall of the main body, the inside of the main body is provided with a threaded hole and a clasp groove, the threaded hole and the clasp groove are in communication, and the threaded hole is arranged on one side of the matching interface.The modular matching design realizes flexible matching of bone defects of different lengths, two main bodies are clamped through end face butt joint, reliable connection is realized through transverse locking of cooperating bolts, different specifications of main bodies can be selected according to the specific length of bone defects of patients to realize combination, and the requirement of clinical emergency and limited period operation is met.

Description

Technical Field

[0001] This invention relates to the field of implant prosthesis technology, specifically a metal additive manufacturing matching long segment bone implant prosthesis. Background Technology

[0002] Long-segment bone defects are a common and complex condition in orthopedic clinics, often caused by bone tumor resection, severe trauma, osteomyelitis, or nonunion. The defect length usually exceeds 1.5 times the diameter of the bone shaft, making satisfactory repair difficult through autologous or allogeneic bone grafts. In recent years, with the rapid development of metal additive manufacturing technology, 3D-printed personalized bone implants have gradually become an important means of reconstructing long-segment bone defects. By layering medical-grade metal materials such as titanium alloys, precise matching with the patient's bone defect morphology can be achieved. At the same time, the porous structure design promotes bone integration, providing a new solution for the repair of large-segment bone defects.

[0003] Existing 3D-printed long-segment bone implants still have shortcomings in actual clinical applications. On the one hand, integrated custom-made implants need to be designed and manufactured individually for each patient, resulting in long production cycles, high costs, and difficulty in mass production, which cannot meet the needs of emergency or time-limited surgeries. On the other hand, the fixation methods are mostly single intramedullary fixation or single bone plate fixation, and the initial stability and long-term biological fixation effect need to be improved. The incidence of postoperative complications such as implant loosening and subsidence is relatively high. Summary of the Invention

[0004] The purpose of this invention is to provide a metal additive manufacturing matching long segment bone implant prosthesis to solve the problems raised in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: The implantable prosthesis includes a main body, one end of which is fixedly connected to an intramedullary fixation rod. A positioning groove is uniformly formed on one side of the intramedullary fixation rod, and a screw hole is formed on the other side. An assembly interface is formed at the other end of the main body. A 3D-printed porous structure is fitted onto the outside of the intramedullary fixation rod. One side of the 3D-printed porous structure is installed on the outer wall of the main body. A threaded hole and a retaining ring groove are formed inside the main body. The threaded hole and the retaining ring groove are connected. The threaded hole is located on one side of the assembly interface, and a connecting structure is installed on the inner wall of the retaining ring groove.

[0006] As a preferred technical solution, the connection structure includes a retaining ring and a bolt. The retaining ring is installed on the inner wall of the retaining ring groove, and a bolt is provided on one side of the retaining ring. The outer wall of the bolt is threaded into a threaded hole.

[0007] As a preferred technical solution, the connection structure further includes a damping pin, a damping pin hole is provided on one side of the bolt, a damping pin is installed on the inner wall of the damping pin hole, and one side of the damping pin is threaded into the threaded hole.

[0008] As a preferred technical solution, the assembly interface is a symmetrical concave-convex mating structure, and the end face of the assembly interface is provided with grooves and protrusions, which are alternately distributed along the circumference of the end face.

[0009] As a preferred technical solution, a bone fixation plate is installed on the outer wall of the main body. The bone fixation plate is a straight bone fixation plate with several screw holes, and screws are threaded into the inner wall of the screw holes.

[0010] As a preferred technical solution, a bone fixation plate is installed on the outer wall of the main body. The bone fixation plate is an anatomical bone fixation plate, which is in the shape of a curved plate. Several screw holes are opened on the anatomical bone fixation plate, and screws are threaded into the inner wall of the screw holes.

[0011] As a preferred technical solution, the intramedullary fixation rod is a tapered rod, and the outer diameter of the tapered rod gradually decreases from the end closest to the main body to the distal end.

[0012] As a preferred technical solution, the 3D printed porous structure includes a bone contact area and a load-bearing area, wherein the bone contact area is located on the outer surface of the main body and the intramedullary fixation rod.

[0013] As a preferred technical solution, the load-bearing area is located in the middle section of the main body, and the 3D printed porous structure surrounds and covers the connection end face between the intramedullary fixation rod and the main body.

[0014] As a preferred technical solution, the inner sidewall of the retaining ring is provided with a guide slope, and the head of the bolt is provided with a conical surface, with the guide slope and the conical surface being arranged opposite to each other.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention achieves flexible matching of bone defects of different lengths through modular assembly design. The two main bodies are connected and locked together by symmetrical concave and convex assembly interfaces on the end faces, and a reliable connection is achieved by lateral locking with bolts. Different specifications of main bodies can be selected and combined according to the specific length of the patient's bone defect, eliminating the need for patients to customize a whole prosthesis, thus meeting the needs of clinical emergency and time-limited surgery.

[0016] 2. This invention optimizes osseointegration and mechanical load-bearing capacity through a 3D-printed porous structure with a zoned design. The porous structure in the bone contact area is located on the outer surface of the main body and the intramedullary fixation rod, and the pore structure adapts to the bone ingrowth requirements, providing space for the ingrowth of new bone tissue. The porous structure in the load-bearing area is located in the middle section of the main body, ensuring the overall mechanical load-bearing capacity of the prosthesis. The intramedullary fixation rod adopts a tapered rod design with surface positioning grooves, which can achieve good initial press-fit stability during implantation. The porous structure surrounds and covers the connecting end face, dispersing stress, reducing stress shielding effect, and reducing bone resorption around the prosthesis.

[0017] 3. This invention provides a dual fixation method of intramedullary fixation and cortical bone plate fixation. The intramedullary fixation rod is inserted into the medullary cavity to provide central fixation. At the same time, a straight bone fixation plate or an anatomical bone fixation plate can be installed according to clinical needs. External fixation of the cortical bone is achieved by screws and the patient's remaining bone, which improves the initial stability and anti-rotation ability of the prosthesis. The two fixation plates are suitable for the repair needs of bone defects in different locations and shapes, thus expanding the scope of application. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the main structure of the present invention; Figure 2 This is a front view of the present invention. Figure 3 This is a side view of the present invention; Figure 4 This is a schematic diagram of the first partial cross-sectional structure of the present invention; Figure 5 This is an exploded view of the present invention; Figure 6 This is a schematic diagram of the first partial structure of the present invention; Figure 7 This is a schematic diagram of the second partial structure of the present invention; Figure 8 yes Figure 2 A schematic diagram of the third local structure.

[0019] In the diagram: 1. Main body; 2. Intramedullary fixation rod; 3. Threaded hole; 4. Straight bone fixation plate; 5. Assembly interface; 6. Anatomical bone fixation plate; 7. 3D printed porous structure; 8. Bolt; 9. Damping pin hole; 10. Damping pin; 11. Positioning groove; 12. Screw; 13. Screw hole; 14. Snap ring; 15. Snap ring groove. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1: As Figure 1 , 5 As shown, this invention provides a technical solution for manufacturing a matching long-segment bone implant prosthesis using metal additive manufacturing. The implant prosthesis includes a main body 1, with an intramedullary fixation rod 2 fixedly connected to one end. Positioning grooves 11 are evenly distributed on one side of the intramedullary fixation rod 2, and screw holes 13 are formed on the other side. An assembly interface 5 is formed at the other end of the main body 1. A 3D-printed porous structure 7 is fitted over the intramedullary fixation rod 2, with one side of the 3D-printed porous structure 7 mounted on the outer wall of the main body 1. Threaded holes 3 and retaining ring grooves 15 are formed inside the main body 1, and the threaded holes 3 and retaining ring grooves 15 are connected. The threaded hole 3 is located on one side of the assembly interface 5. The inner wall of the retaining ring groove 15 is equipped with a connecting structure. The intramedullary fixation rod 2 is a tapered rod. The outer diameter of the tapered rod gradually decreases from the end near the main body 1 to the distal end. The 3D printed porous structure 7 includes a bone contact area and a load-bearing area. The bone contact area is located on the outer surface of the main body 1 and the intramedullary fixation rod 2. The load-bearing area is located in the middle section of the main body 1. The 3D printed porous structure 7 surrounds and covers the connection end face between the intramedullary fixation rod 2 and the main body 1. The inner side wall of the retaining ring 14 is provided with a guide slope. The head of the bolt 8 is provided with a tapered surface. The guide slope and the tapered surface are set opposite to each other. The two main bodies 1 serve as the load-bearing components of the prosthesis, integrally molded from medical-grade titanium alloy using metal additive manufacturing technology. Each main body 1 has an intramedullary fixation rod 2 at one end and an assembly interface 5 at the other end. The two main bodies 1 are connected and assembled through the assembly interface 5 to accommodate bone defect repair needs of different lengths. The intramedullary fixation rod 2 is coaxially arranged with the main body 1 and has an overall conical rod structure. The outer diameter gradually decreases from the root near the main body 1 to the distal end, facilitating insertion into the patient's medullary cavity for press-fit fixation. Multiple positioning grooves 11 are evenly opened along the axial direction on the surface of the intramedullary fixation rod 2. During implantation, the positioning grooves 11 interlock with the bone protrusions on the inner wall of the medullary cavity to prevent the prosthesis from rotating. The screw hole 13 on the other side of the intramedullary fixation rod 2 can be used to insert locking screws as needed to further enhance the fixation effect. The 3D-printed porous structure 7, connected to the main body 1 and the intramedullary fixation rod 2, is divided into two functional zones: a bone contact area and a load-bearing area. The bone contact area is distributed on the outer surface of the main body 1 and the intramedullary fixation rod 2, with pore size and porosity adapted to the bone tissue ingrowth requirements, providing a scaffold for new bone ingrowth and achieving biointegration of the prosthesis with the host bone. The load-bearing area is distributed in the middle load-bearing part of the main body 1, maintaining high strength while ensuring a certain porosity to meet the load-bearing requirements of the load-bearing part. The 3D-printed porous structure 7 surrounds and covers the connection end face between the intramedullary fixation rod 2 and the main body 1, dispersing stress concentration in this part and reducing stress shielding effect. The threaded hole 3 inside the main body 1 is arranged radially and communicates with the retaining ring groove 15 for installing the connection structure to achieve locking and fixation between the two main bodies 1.

[0022] like Figure 4 , Figure 5 As shown, the connection structure includes a retaining ring 14 and a bolt 8. The retaining ring 14 is installed on the inner wall of the retaining ring groove 15, and the bolt 8 is provided on one side of the retaining ring 14. The outer wall of the bolt 8 is threaded into the threaded hole 3. The connection structure also includes a damping pin 10. A damping pin hole 9 is opened on one side of the bolt 8. The damping pin 10 is installed on the inner wall of the damping pin hole 9. One side of the damping pin 10 is threaded into the threaded hole 3. The assembly interface 5 is a symmetrical concave-convex fit structure. The end face of the assembly interface 5 is provided with grooves and protrusions, and the grooves and protrusions are alternately distributed along the circumferential direction of the end face. The assembly interface 5 is located on the mating end face of the main body 1, adopting a symmetrical concave-convex fit structure. The end face has alternating grooves and protrusions distributed circumferentially. When the two main bodies 1 are mated, the protrusion of one main body is embedded into the groove of the other main body, forming a circumferential fit to transmit torque, preventing relative rotation between the two main bodies, and ensuring the overall stability after mating. The connecting structure is used to lock and fix the two mated main bodies 1. The bolt 8 is screwed into the threaded hole 3 from the side of the main body 1. The shank of the bolt 8 passes laterally through the junction of the assembly interface 5 of the two main bodies 1, locking the two main bodies 1 in series. The retaining ring 14 is installed in the retaining ring groove 15 and sleeved on the outer periphery of the bolt 8. The guide on the inner side of the retaining ring 14 The inclined surface and the conical surface of the bolt head cooperate with each other. The deeper the bolt 8 is screwed in, the more the conical surface compresses the guide inclined surface, causing the retaining ring 14 to expand outward. The outer wall of the retaining ring 14 fits tightly with the inner wall of the retaining ring groove 15, forming a tightening fixation to prevent the bolt 8 from loosening and unscrewing. The damping pin 10 is installed in the damping pin hole 9 inside the bolt 8. The outer end of the damping pin 10 is threaded to the inner wall of the threaded hole 3. Through the thread friction between the damping pin 10 and the threaded hole 3, the anti-loosening ability of the bolt 8 is further increased, preventing the prosthesis from loosening under long-term physiological load. At the same time, the damping pin 10 can absorb some vibration energy, reduce the impact of stress concentration on the connection part, and improve the fatigue life of the connection structure.

[0023] Example 2: Compared with Example 1, the main difference is that a straight bone fixation plate 4 is installed on the outer wall of the main body 1.

[0024] like Figure 5 , Figure 6 As shown, a bone fixation plate is installed on the outer wall of the main body 1. The bone fixation plate is a straight bone fixation plate 4. Several screw holes 13 are opened on the straight bone fixation plate 4, and screws 12 are threaded into the inner wall of the screw holes 13. The straight bone fixation plate 4 is a flat, elongated plate structure that is fixed to the outer wall of the main body 1 by screws 12. It is suitable for repairing long bone defects in the bone shaft. Multiple screw holes 13 are evenly opened along the length of the straight bone fixation plate 4. The screws 12 pass through the screw holes 13 and are screwed into the remaining cortical bone of the patient, fixing the prosthesis to the host bone from the outside. Together with the intramedullary fixation of the intramedullary fixation rod 2, it forms a dual fixation system of inside and outside, which improves the overall stability of the prosthesis and its anti-rotation and anti-subsidence capabilities. The installation position and the number of screws can be adjusted as needed to meet the fixation requirements of different scenarios.

[0025] Example 3: Compared with Examples 1 and 2, the main difference is that the outer wall of the main body 1 is fitted with an anatomical bone fixation plate 6.

[0026] like Figure 2 , Figure 3 , Figure 7 , Figure 8As shown, a bone fixation plate is installed on the outer wall of the main body 1. The bone fixation plate is an anatomical bone fixation plate 6. The anatomical bone fixation plate 6 is in the shape of a curved plate. Several screw holes 13 are opened on the anatomical bone fixation plate 6. Screws 12 are threaded into the inner wall of the screw holes 13. The anatomical bone fixation plate 6 is a curved plate structure designed according to the anatomical morphology of the human skeleton. Its curvature matches the curvature of the bone surface, allowing for better conformation to the bone surface. It is suitable for repairing bone defects near the metaphysis or joints. The anatomical bone fixation plate 6 has multiple screw holes 13 evenly distributed on its surface, which are fixed to the patient's remaining bone through screws 12. The anatomical design makes the fixation plate more closely contact the bone surface, resulting in a more reliable fixation effect, while reducing irritation and compression to surrounding soft tissues. Two different shapes of bone fixation plates are available, allowing the prosthesis to be adapted to the repair of long bone defects of different locations and shapes, thus expanding the scope of clinical application.

[0027] It should be noted that the fracture site can be directly connected using the symmetrically arranged main body 1, or either Embodiment 1 or Embodiment 2 can be selected. Depending on the bone defect condition of different patients, six combinations can be achieved: neither of the two symmetrically arranged main bodies 1 has a bone fixation plate; one of the two symmetrically arranged main bodies 1 has no bone fixation plate and the other has a straight bone fixation plate 4; one of the two symmetrically arranged main bodies 1 has no bone fixation plate and the other has an anatomical bone fixation plate 6; both of the two symmetrically arranged main bodies 1 have a straight bone fixation plate 4; one of the two symmetrically arranged main bodies 1 has a straight bone fixation plate 4 and the other has an anatomical bone fixation plate 6; and both of the two symmetrically arranged main bodies 1 have an anatomical bone fixation plate 6. Through these combinations, adaptive connections can be achieved for various bone defect conditions.

[0028] The working principle of this invention is as follows: Before use, according to the length and shape of the patient's bone defect, select a suitable main body 1 for assembly; the two main bodies 1 are connected to each other through the assembly interface 5 opened on their respective end faces, so that the assembly interface 5 of the two main bodies 1 are engaged; after the two main bodies 1 are connected, the bolt 8 is screwed into the threaded hole 3 from one side of the main body 1, and the shank of the bolt 8 passes through the junction of the assembly interface 5 of the two main bodies 1, locking and fixing the two main bodies 1; when the bolt 8 is screwed in, the retaining ring 14 in the retaining ring groove 15 is sleeved on the outer peripheral side wall of the bolt 8, and the damping pin 10 is installed in the damping pin hole 9 inside the bolt 8, and the damping pin 10 abuts against the inner wall of the threaded hole 3; Next, the intramedullary fixation rod 2 is inserted into the medullary cavity of the patient's bone shaft. The intramedullary fixation rod 2 is a tapered rod, and the positioning groove 11 on the outer sidewall of the intramedullary fixation rod 2 fits into the bone protrusion on the inner wall of the medullary cavity. The 3D-printed porous structure 7 is set on the outer wall of the main body 1 and the outside of the intramedullary fixation rod 2, and the 3D-printed porous structure 7 surrounds and covers the connection end face between the intramedullary fixation rod 2 and the main body 1. Depending on clinical needs, the outer wall of the main body 1 can be equipped with a combination of two types of bone fixation plates: straight bone fixation plate 4, anatomical bone fixation plate 6, and no bone fixation plate. After combination, in the part without bone fixation plate, the main body 1 only cooperates with the medullary cavity through the intramedullary fixation rod 2; in the part with straight bone fixation plate 4, the straight bone fixation plate 4 is fixed to the patient's remaining bone through the screw hole 13 on it by screw 12; in the part with anatomical bone fixation plate 6, the anatomical bone fixation plate 6 is fixed to the patient's remaining bone through the screw hole 13 on it by screw 12, thus completing the bone fixation connection.

[0029] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A metal additive manufacturing matching long-segment bone implant prosthesis, characterized in that: The implant includes a main body (1), one end of which is fixedly connected to an intramedullary fixation rod (2). A positioning groove (11) is evenly provided on one side of the intramedullary fixation rod (2), and a screw hole (13) is provided on the other side of the intramedullary fixation rod (2). An assembly interface (5) is provided at the other end of the main body (1). A 3D printed porous structure (7) is sleeved on the outside of the intramedullary fixation rod (2). One side of the 3D printed porous structure (7) is installed on the outer wall of the main body (1). A threaded hole (3) and a retaining ring groove (15) are provided inside the main body (1). The threaded hole (3) and the retaining ring groove (15) are connected. The threaded hole (3) is located on one side of the assembly interface (5). A connecting structure is installed on the inner wall of the retaining ring groove (15).

2. The metal additive manufacturing matching long segment bone implant prosthesis according to claim 1, characterized in that: The connection structure includes a retaining ring (14) and a bolt (8). The retaining ring (14) is installed on the inner wall of the retaining ring groove (15). A bolt (8) is provided on one side of the retaining ring (14). The outer wall of the bolt (8) is threaded into the threaded hole (3).

3. The metal additive manufacturing matching long segment bone implant prosthesis according to claim 2, characterized in that: The connection structure also includes a damping pin (10), a damping pin hole (9) is provided on one side of the bolt (8), a damping pin (10) is installed on the inner wall of the damping pin hole (9), and one side of the damping pin (10) is threaded into the threaded hole (3).

4. The metal additive manufacturing matching long segment bone implant prosthesis according to claim 1, characterized in that: The assembly interface (5) is a symmetrical concave-convex mating structure. The end face of the assembly interface (5) is provided with grooves and protrusions, and the grooves and protrusions are alternately distributed along the circumference of the end face.

5. The metal additive manufacturing matching long segment bone implant prosthesis according to claim 1, characterized in that: The outer wall of the main body (1) is fitted with a bone fixation plate, which is a straight bone fixation plate (4). The straight bone fixation plate (4) has several screw holes (13), and screws (12) are threaded into the inner wall of the screw holes (13).

6. The metal additive manufacturing matching long segment bone implant prosthesis according to claim 1, characterized in that: The outer wall of the main body (1) is fitted with a bone fixation plate, which is an anatomical bone fixation plate (6). The anatomical bone fixation plate (6) is in the shape of a curved plate. Several screw holes (13) are provided on the anatomical bone fixation plate (6), and screws (12) are threaded into the inner wall of the screw holes (13).

7. A metal additive manufacturing matching long-segment bone implant prosthesis according to claim 1, characterized in that: The intramedullary fixation rod (2) is a tapered rod, and the outer diameter of the tapered rod gradually decreases from the end closest to the main body (1) to the distal end.

8. A metal additive manufacturing matching long-segment bone implant prosthesis according to claim 1, characterized in that: The 3D printed porous structure (7) includes a bone contact area and a load-bearing area, wherein the bone contact area is located on the outer surface of the main body (1) and the intramedullary fixation rod (2).

9. A metal additive manufacturing matching long-segment bone implant prosthesis according to claim 8, characterized in that: The load-bearing area is located in the middle section of the main body (1), and the 3D printed porous structure (7) surrounds and covers the connection end face between the intramedullary fixation rod (2) and the main body (1).

10. A metal additive manufacturing matching long-segment bone implant prosthesis according to claim 2, characterized in that: The inner wall of the retaining ring (14) is provided with a guide slope, and the head of the bolt (8) is provided with a conical surface. The guide slope and the conical surface are arranged opposite to each other.

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