Pelvic brittle fracture bionic hollow screw manufactured based on 3D printing technology

Abstract

The utility model discloses a pelvic brittle fracture bionic hollow screw manufactured based on the 3D printing technology. The pelvic brittle fracture bionic hollow screw manufactured based on the 3D printing technology comprises a screw body, and the screw body comprises a screw tail, a supporting part and a screw head; a thread, a diversion trench and a microporous structure are arranged on the supporting part; the micropore structure comprises a plurality of point position sets spirally arranged on the supporting part, and the difference between every two adjacent point position sets is one fourth of the circumference. According to the pelvic brittle fracture bionic hollow screw manufactured based on the 3D printing technology, the screw body manufactured through the D printing technology is arranged, a micro-pore structure distributed in a topological configuration mode can be conveniently arranged on the screw body, bone cement can be conveniently spread around the screw body in a more dispersed mode through the micro-pore structure, and therefore the bone cement can be more evenly distributed on the periphery of the screw body. And the micropore structure is beneficial to bone tissue growth, so that the long-term stability of the screw is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of orthopedic medical devices, in particular to a bionic hollow screw for pelvic fragility fractures manufactured based on 3D printing technology. Background Art

[0002] With the progress of population aging, fragility pelvic fractures are characterized by "three highs", namely high incidence, high mortality, and high loss rate of independent mobility. Currently, surgical treatment is recommended for fragility pelvic fractures, especially minimally invasive internal fixation technology is the first choice. However, due to severe osteoporosis in elderly patients, the failure rate increases.

[0003] Generally, a hollow screw channel or bone cement injection around the screw can be used to improve the immediate stability of fixation. However, after the conventional screw is injected with bone cement, the bone cement dispersion is poor, resulting in little improvement in the screw stability, and thus the fixation effect of the screw is not significantly improved.

[0004] Therefore, it is necessary to provide a bionic hollow screw for pelvic fragility fractures manufactured based on 3D printing technology to solve the above technical problems. Summary of the Utility Model

[0005] In view of the above situation, to overcome the defects of the prior art, the utility model provides a bionic hollow screw for pelvic fragility fractures manufactured based on 3D printing technology, which can improve the dispersion of bone cement and the stability of the screw.

[0006] To achieve the above purpose, the technical scheme adopted by the utility model is as follows:

[0007] A bionic hollow screw for pelvic fragility fractures manufactured based on 3D printing technology includes: a screw body manufactured by 3D printing technology, the screw body includes a screw tail, a support part, and a screw head; the support part is provided with threads, flow guide grooves, and micropore structures, and the number of flow guide grooves is three; the micropore structure includes multiple point groups spirally arranged on the support part, and adjacent two point groups differ by a quarter of a circumference, and each point group includes three through holes evenly distributed on one-third of the circumference of the support part, and the flow guide grooves are connected to the through holes.

[0008] Preferably, the aperture of the through hole gradually increases from the screw tail to the screw head direction, and the aperture of the through hole is 200 - 500 μm.

[0009] Preferably, the through hole is inclined, and the inclination angle is 45 ± 5 degrees.

[0010] Preferably, the screw head is designed with a flared opening.

[0011] Preferably, a hexagonal groove is opened at the end of the screw tail.

[0012] Preferably, the through hole is circular or elliptical.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] (1) By arranging the screw body manufactured by 3D printing technology, the microporous structure with topological configuration distribution can be conveniently arranged on the screw body. By using the microporous structure, the bone cement can be more conveniently and dispersedly distributed around the screw body, improving the immediate stability of the screw. The microporous structure is beneficial to bone tissue growth, thereby improving the long-term stability of the screw;

[0015] (2) By arranging the inclined through holes, the bone cement can flow out of the central hole conveniently;

[0016] (3) By arranging the nail head with a flared design, the possibility of bone cement backflow can be effectively reduced;

[0017] (4) By opening a hexagonal groove at the end of the nail tail, the bionic hollow screw can be fixed at the end of the screwdriver, making it more convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 FIG. is a schematic structural view of the bionic hollow screw for pelvic fragility fracture manufactured based on 3D printing technology provided by the utility model;

[0019] Figure 2 is Figure 1 The front view structural schematic diagram of the bionic hollow screw for pelvic fragility fracture manufactured based on 3D printing technology shown in;

[0020] Figure 3 is Figure 1 The side view structural schematic diagram of the bionic hollow screw for pelvic fragility fracture manufactured based on 3D printing technology shown in;

[0021] Figure 4 is Figure 1 The partial cross-sectional structural schematic diagram of the bionic hollow screw for pelvic fragility fracture manufactured based on 3D printing technology shown in;

[0022] Figure 5 is Figure 1 The distribution position schematic diagram of the through holes in the bionic hollow screw for pelvic fragility fracture manufactured based on 3D printing technology shown in.

[0023] Wherein, the names corresponding to the reference numerals are: 1 - nail tail, 2 - support part, 3 - nail head, 4 - central hole, 5 - hexagonal groove, 6 - through hole, 7 - diversion groove. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following further describes the utility model with reference to the drawings and embodiments. The implementation manners of the utility model include but are not limited to the following embodiments.

[0025] Example 1:

[0026] As Figures 1-5 shown, the bionic hollow screw for pelvic fragility fracture manufactured based on 3D printing technology provided by the present utility model includes: a screw body manufactured by 3D printing technology, and medical materials such as titanium alloy can be used for the material. The screw body includes a screw tail 1, a support part 2, and a screw head 3. A central hole 4 with a diameter of 2.5 mm is provided on the screw body 1. The screw tail 1 is 5 mm long and has a maximum diameter of 7.5 mm. The support part 2 has a diameter of 7.3 mm (this data is designed according to the patient's preoperative CT image data, and the specific value of the diameter can be adjusted according to the surgical needs). A full thread or a half thread is provided on the outside thereof, and the thread pitch is 2 mm. A diversion groove 7 is provided on the support part 2. There are three diversion grooves 7, and the diversion grooves 7 are spirally arranged. In order to improve the dispersion of bone cement, a microporous structure with a topological configuration is provided on the support part 2. The microporous structure includes a plurality of through holes 6 spirally arranged along the support part 2. The through holes 6 are circular or elliptical. In this embodiment, the elliptical shape is taken as an example for illustration. Specifically, three through holes 6 are a point group and are arranged in a topological configuration along the surface of the support part 2. Every 90 degrees of rotation, a group of through holes 6 is provided. The three through holes 6 in each point group are distributed on the 120-degree circumference of the support part 2 (see Figure 5As shown in the figure, the diversion groove 7 is connected to a part of the through holes 6. The inner side of the through holes 6 communicates with the central hole 4, so that the central hole 4 communicates with the outside through the through holes 6. The aperture of the through holes 6 gradually increases from the nail tail 1 to the nail head 3. The aperture of the through holes 6 is 200 - 500 μm. The aperture of the through holes 6 near the nail tail 1 is 200 - 300 μm, and the aperture of the through holes 6 near the nail head 3 is 400 - 500 μm, so that the porosity on the surface of the support part 2 reaches a change range of 60% - 75%. That is, at the position near the nail tail 1, the porosity is 60 ± 3%, and at the position near the nail head 3, the porosity can reach 75 ± 3%. During use, using 3D printing technology, combined with the patient's CT data (slice thickness 0.625 mm), body mass index, and Singh index (osteoporosis grading), a personalized customized bionic hollow screw is automatically generated and printed to meet the fixation needs of patients with brittle pelvic fractures. Under the guidance of intraoperative imaging or a navigation system, a 2.5 mm diameter pelvic hollow screw guide needle is inserted. According to the fracture type and fixation requirements, a semi-threaded or fully threaded hollow nail is selected. Drill holes are made using a drill bit according to bone mass or not. A matching screwdriver is fixed to the nail tail 1, and under the control of a power screwdriver or a manual screwdriver, the hollow nail is screwed into the specified position of the pelvic bone. Then, under the guidance of the guide needle, a bone cement injector is screwed in, and the bone cement injector is fixed to the nail tail 1. With the assistance of the bone cement injector, an appropriate amount of bone cement is pushed into the central hole 4. The bone cement advances along the central hole 4 to fill the entire central hole 4, and then enters the diversion groove 7 and the outside of the hollow nail through the through holes 6. The bone cement can flow along the diversion groove 7, thereby improving the dispersion of the bone cement, enabling the bone cement to better fill the gap between the hollow nail and the bone, improving the immediate stability of the hollow nail. In addition, the through holes 6 with a microporous structure are more conducive to the growth of bone tissue into them, so as to obtain long-term stability. This kind of microporous structure causes less change in the overall stress of the hollow nail 1 compared with the traditional large-diameter side holes, and the stress of the hollow nail 1 can be more concentrated.

[0027] By setting a screw body manufactured using 3D printing technology, a microporous structure with a topological configuration distribution can be conveniently set on the screw body. Using the microporous structure, the bone cement can be more conveniently and dispersedly distributed around the screw body, improving the immediate stability of the screw. The microporous structure is conducive to the growth of bone tissue, thereby improving the long-term stability of the screw.

[0028] Example 2:

[0029] As Figure 4 shown, the through holes 6 are inclined, and the inclination angle is 45 ± 5 degrees, that is, the axial angle between the through holes 6 and the support part 2 is 45 ± 3 degrees. During use, the bone cement in the central hole 4 is discharged outward through the inclined through holes 6, so that the flow direction of the bone cement forms an inclined angle of about 45 degrees with the bone, thereby reducing the flow resistance of the bone cement and making the bone cement easier to flow out.

[0030] By setting the inclined through-hole 6, it is convenient for the bone cement to flow out from the central hole 4.

[0031] Embodiment 3:

[0032] As Figures 1-2 shown, the outer side of the nail head 3 is a self-tapping screw design, and its opening is a flared design with a smaller inner diameter and a larger outer diameter. After the bone cement flows out from the nail head 3, it fills the gap between the nail head 3 and the bone. Because the inner opening of the nail head 3 is small and there is more bone cement outside, blocking at the nail head 3, its flow resistance is greater, making it difficult for the outer bone cement to flow back from the nail head 3 into the central hole 4.

[0033] By setting the nail head 3 with a flared design, the possibility of bone cement backflow can be effectively reduced.

[0034] Embodiment 4:

[0035] As Figure 3 shown, a hexagonal groove 5 is opened at the end of the nail tail 1. During use, a screwdriver matching the hexagonal groove 5 is inserted into the hexagonal groove 5, and then the bionic hollow screw can be fixed at the end of the screwdriver, which is convenient for installing the hollow screw at the surgical position.

[0036] By opening the hexagonal groove 5 at the end of the nail tail 1, the bionic hollow screw can be fixed at the end of the screwdriver, making it more convenient to use.

[0037] Working principle: During use, with 3D printing technology, combined with the patient's CT data (slice thickness 0.625mm), body mass index, and Singh index (osteoporosis grading), a personalized customized bionic hollow screw is automatically generated and printed to meet the fixation needs of patients with brittle pelvic fractures. Under the guidance of intraoperative imaging or a navigation system, a pelvic hollow screw guide pin with a diameter of 2.5mm is inserted. According to the fracture type and fixation requirements, a semi-threaded or fully-threaded hollow nail is selected. A drill bit is used / not used for opening a hole according to the bone mass. A matching screwdriver is fixed to the nail tail 1, and under the control of a power screwdriver or a manual screwdriver, the hollow nail is screwed into the designated position of the pelvic bone. Then, under the guidance of the guide pin, a bone cement injector is screwed in and fixed to the nail tail 1. With the assistance of the bone cement injector, an appropriate amount of bone cement is pushed into the central hole 4. The bone cement advances along the central hole 4 to fill the entire central hole 4, and then enters the diversion groove 7 and the outside of the hollow nail through the through-hole 6. The bone cement can flow along the diversion groove

Claims

1. A bionic hollow screw for pelvic fragility fractures manufactured based on 3D printing technology, characterized in that, Comprising: A screw body, the screw body including a nail tail (1), a support portion (2) and a nail head (3); The support portion (2) is provided with threads, a diversion groove (7) and a microporous structure; The microporous structure includes a plurality of point groups spirally arranged on the support portion (2), and two adjacent point groups differ by a quarter of a circumference; The point group includes three through holes (6) evenly distributed on one-third of the circumference of the support portion (2), and the diversion groove (7) is connected to the through hole (6).

2. The bionic hollow screw for pelvic fragility fractures manufactured based on 3D printing technology according to claim 1, wherein, The number of the diversion grooves (7) is three.

3. A bionic hollow screw for pelvic fragility fractures manufactured based on 3D printing technology according to claim 1, characterized in that, The aperture of the through hole (6) gradually increases from the nail tail (1) towards the nail head (3), and the range is 200 - 500 μm.

4. A bionic hollow screw for pelvic fragility fractures manufactured based on 3D printing technology according to claim 1, characterized in that, The through hole (6) is inclined, and the inclination angle is 45 ± 5 degrees.

5. A bionic hollow screw for pelvic fragility fractures manufactured based on 3D printing technology according to claim 1, characterized in that, The nail head (3) is designed with a flared opening.

6. The bionic hollow screw for pelvic fragility fracture manufactured based on 3D printing technology according to claim 1, wherein, A hexagonal groove (5) is opened at the end of the nail tail (1).

7. A bionic hollow screw for pelvic fragility fractures manufactured based on 3D printing technology according to claim 1, characterized in that, The through hole (6) is circular or oval.

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