CN112743045A

CN112743045A - Magnesium screw for bone tissue fixation and preparation method thereof

Info

Publication number: CN112743045A
Application number: CN202011598350.4A
Authority: CN
Inventors: 李扬德; 李扬立德
Original assignee: Dongguan Lide Biological Medical Co ltd
Current assignee: Dongguan Lide Biological Medical Co ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-05-04
Anticipated expiration: 2040-12-29
Also published as: CN112743045B

Abstract

The invention discloses a magnesium screw for bone tissue fixation and a preparation method thereof, wherein a concave-convex mould is adopted to prepare the magnesium screw, the concave-convex mould comprises a concave mould and a forming convex mould, the magnesium screw is provided with a groove, and the preparation steps comprise: (1) heating the metal magnesium material to form a liquid or semi-solid metal magnesium material; (2) one end of the forming male die extends into the die cavity for a certain depth, and the other end of the forming male die is connected with a high-frequency vibration device; (3) filling the die cavity with the liquid or semi-solid magnesium metal material; (4) starting the high-frequency vibration device, wherein the vibration frequency is 100-15 KHz, and after working for a certain time, closing the high-frequency vibration device; (5) and cooling for a period of time, taking out the forming male die, and taking out the magnesium screw from the die cavity. According to the magnesium screw, the magnesium screw with excellent density and mechanical property is prepared from the metal magnesium material by adopting the concave-convex mould and the high-frequency vibration device, the corrosion resistance is good, the degradation rate is slow after the magnesium screw is implanted into a human body, the method is simple, the cost is lower, and the mass production can be realized.

Description

Magnesium screw for bone tissue fixation and preparation method thereof

Technical Field

The invention relates to the field of medical screw products, in particular to a magnesium screw for fixing bone tissues and a preparation method thereof.

Background

In the clinical practice of surgery, operations such as bone grafting, joint fusion, joint fixation, and orthopedic surgery are often used for the treatment of diseases such as bone fracture and bone repair, and a fixation method is generally used in the operation. At present, metal fixing screws (stainless steel materials, titanium alloy materials and the like) are mostly adopted for clinical fracture internal fixation, and the metal fixing screws have high mechanical properties, but are not degradable and can not be absorbed by human bodies, so that a secondary operation is needed to take out a fixed object after fracture healing of a patient, and secondary pain and economic burden of the patient are increased.

The magnesium or magnesium alloy has good mechanical compatibility and biocompatibility, and is an ideal biomedical material. Therefore, biomedical magnesium alloys are receiving more and more attention from biomaterial workers worldwide. The pure magnesium material does not contain silicon, when the magnesium material is used for preparing magnesium orthopedic screws, the preparation mode is limited, casting technology is not generally adopted, and even if the magnesium orthopedic screws are adopted, the magnesium oxide formed by oxidation is loose and porous and has poor protection performance due to high chemical activity and low standard electrode potential, so that the magnesium orthopedic screws are generally prepared by adopting an extrusion process, but the mass production is difficult to realize by the extrusion process.

Therefore, there is a need to develop a magnesium screw for bone tissue fixation and a method for preparing the same to solve the above-mentioned drawbacks.

Disclosure of Invention

One of the purposes of the invention is to provide a preparation method of a magnesium screw for bone tissue fixation, which adopts a concave-convex mould to prepare a magnesium screw with compact structure and good mechanical property from a metal magnesium material, has good corrosion resistance, is slow in degradation rate after being implanted into a human body, has simple process and lower cost, and can realize mass production.

The invention also aims to provide the magnesium screw for fixing the bone tissue prepared by the method.

In order to achieve the purpose, the invention discloses a method for preparing a magnesium screw for bone tissue fixation, which adopts a concave-convex die to prepare the magnesium screw, wherein the concave-convex die comprises a concave die and a forming convex die, and the concave die is provided with an open conical die cavity; the magnesium screw is provided with a first end and a second end, a groove is concavely arranged along the direction from the first end to the second end,

the preparation method comprises the following steps:

(1) providing a metal magnesium material, and heating the metal magnesium material to form a liquid or semi-solid metal magnesium material;

(2) extending one end of the forming male die into the die cavity for a certain depth, and connecting the other end of the forming male die with a high-frequency vibration device;

(3) filling the die cavity with the liquid or semi-solid magnesium metal material;

(4) starting the high-frequency vibration device, wherein the vibration frequency is 100-15 KHz, and after working for a certain time, closing the high-frequency vibration device;

(5) and cooling for a period of time, taking out the forming male die, and taking out the magnesium screw from the die cavity.

Compared with the prior art, the preparation method of the magnesium screw for bone tissue fixation adopts the concave-convex mould and prepares the magnesium screw from the metal magnesium material by means of the high-frequency vibration device, the method is simple, the cost is lower, and mass production can be realized. In the preparation process, the density of the magnesium screw is improved under the action of the high-frequency vibration device, and the magnesium screw has good mechanical property and corrosion resistance and is slow in degradation rate after being implanted into a human body. Meanwhile, the magnesium screw is not easy to break when screwed into the bone due to the forming convex die which is used for forming the groove, so that the safety performance of the magnesium screw can be improved.

Preferably, the vibration frequency is 500 to 15KHz, and more preferably, the vibration frequency is 1KHz to 10 KHz.

Preferably, the depth of the forming convex mold extending into the mold cavity is less than or equal to 4/5 of the depth of the mold cavity.

Preferably, in the step (1), the heating method is any one selected from the group consisting of high-frequency heating, heating tube heating, electron beam heating, laser heating and steam heating.

Preferably, in the step (5), the cooling mode is that a cooling pipeline is arranged on the concave-convex mould, and water, oil or steam is filled in the pipeline.

Preferably, the magnesium metal material comprises the following components in percentage by weight: 99.98-99.99% of magnesium, 0.002-0.004%, 0.003-0.006% of Ca0.002-0.004%, and 0.003-0.006% of Mn0.003-0.006%.

Preferably, the cross section of the forming male die is polygonal.

Preferably, the cross section of the forming male die is of a trilateral, quadrilateral, pentagonal or hexagonal structure.

Preferably, the cross section of the groove is polygonal, such as a trilateral, quadrilateral, pentagonal or hexagonal structure.

Preferably, the magnesium screw is subjected to numerical control machining to form a thread.

Preferably, the inner wall of the mold cavity is provided with a concave-convex structure for forming threads.

Preferably, in the step (4), the high-frequency vibration device continues to add part of the liquid magnesium metal material into the die cavity during operation.

Correspondingly, the application also provides a magnesium screw for bone tissue fixation, which is prepared by adopting the preparation method of the magnesium screw for bone tissue fixation.

Drawings

FIG. 1 is a schematic view showing a connection relationship between a male and female mold and a high-frequency vibration device according to the present invention.

Figure 2 is a top view of the forming punch of figure 1.

Figure 3 is a top view of another embodiment of the forming punch shown in figure 2.

Fig. 4 is a magnesium screw manufactured using the concave-convex mold and the high-frequency vibration device of fig. 1.

Fig. 5 is a structural schematic diagram of the magnesium screw of fig. 4 which is processed into threads by adopting a numerical control processing technology.

Fig. 6 is a sectional view of the magnesium screw shown in fig. 5.

FIG. 7 is a schematic structural diagram of another embodiment of the connection relationship between the male and female molds and the high frequency vibration device according to the present invention.

FIG. 8 is a top view of an embodiment of a female mold in the male and female molds of the invention.

Description of the symbols:

the die comprises a concave-convex die 10, a concave die 11, a die cavity 111, a concave-convex structure 113, a forming convex die 13, a water pipe channel 14, a left die 15, a right die 16, a high-frequency vibration device 20, a magnesium screw 30, a first end 31, a second end 33, a groove 35 and threads 37.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 6, in the method for preparing a magnesium screw 30 for bone tissue fixation according to the present invention, a concave-convex mold 10 is used to prepare the magnesium screw 30, the concave-convex mold 10 includes a concave mold 11 and a forming convex mold 13, the concave mold 11 has an open tapered mold cavity 111; the magnesium screw 30 has a first end 31 and a second end 33, the second end 33 having a tip, and a groove 35 recessed along the first end 31 in a direction toward the second end 33.

The preparation of the magnesium screw 30 for bone tissue fixation includes:

(2) extending one end of the forming male die 13 into the die cavity 111 for a certain depth, and connecting the other end of the forming male die 13 with a high-frequency vibration device 20;

(3) filling the die cavity 111 with the liquid or semi-solid magnesium metal material;

(4) starting the high-frequency vibration device 20, wherein the vibration frequency is 100-15 KHz, and after working for a certain time, closing the high-frequency vibration device 20;

(5) after cooling for a while, the forming punch 13 is removed, and the magnesium screw 30 is removed from the cavity 111.

Preferably, the magnesium metal material comprises the following components in percentage by weight: 99.98-99.99% of magnesium, 0.002-0.004%, 0.003-0.006% of Ca0.002-0.004%, and 0.003-0.006% of Mn0.003-0.006%. Wherein the heating mode is selected from any one of high-frequency heating, heating tube heating, electron beam heating, laser heating and steam heating. Further, in the step (4), during the operation of the high-frequency vibration device 20, part of the liquid magnesium metal material is continuously added into the mold cavity 111, so as to further improve the compactness of the magnesium screw 30. In the step (5), the cooling mode is that a cooling pipeline is arranged on the concave-convex mould 10, and water, oil or steam is filled in the pipeline.

Specifically, fig. 1 shows a schematic structural diagram of a connection relationship between the concave-convex mold 10 and the high-frequency vibration device 20. The male and female mold 10 includes a female mold 11 and a forming male mold 13, and the female mold 11 has an open cavity 111 with a tapered shape, that is, the tip of the tapered structure of the cavity 111 corresponds to the tip of the magnesium screw 30. The female die 11 may be integrally formed and then opened with the cavity 111. Of course, for the convenience of later taking out the magnesium screw 30, referring to fig. 8, the female die 11 includes a left die 15 and a right die 16 connected with each other, the left die 15 and the right die 16 are detachably connected, the left die 15 and the right die 16 are closed to form the die cavity 111, and in step (5), the left die 15 and the right die 16 are disassembled, and the magnesium screw 30 is taken out from the die cavity 111. One end of the forming male die 13 extends into the die cavity 111 for a certain depth, the other end of the forming male die 13 is connected with the high-frequency vibration device 20, and the high-frequency vibration device 20 can drive the forming male die 13 to perform high-frequency vibration, that is, the forming male die 13 is driven to perform high-frequency vibration under the action of the high-frequency vibration device 20, so that the metal magnesium materials are more compact and more uniform in arrangement, the looseness is reduced, the corrosion resistance is improved, and the degradation rate of the metal magnesium materials can be reduced. It should also be noted that in a preferred embodiment, a water pipe 14 is provided in the female mold 11, and the water pipe 14 is filled with a liquid, such as water, for heat dissipation. Preferably, the high-frequency technology is performed on the female die 11 so as to further melt the semi-solid metal magnesium material, which is beneficial to production, the vibration frequency is 100-15 KHz, preferably 1 KHz-10 KHz, and simultaneously, the magnesium rod can be directly placed in the die cavity 111, and the high-frequency technology is performed on the female die 11 so as to melt the magnesium rod to form the semi-solid metal magnesium material.

Referring to fig. 1, since the forming punch 13 needs to extend into the cavity 111, the radial width of the forming punch 13 is smaller than that of the cavity 111, and the specific size of the forming punch 13 may be determined according to the groove 35 of the magnesium screw 30, which is not limited herein. Preferably, the depth of the molding punch 13 extending into the cavity 111 is less than or equal to 4/5 of the depth of the cavity 111, so that the depth of the groove 35 is less than or equal to 4/5 of the length of the magnesium screw 30, when the fracture of the patient is fixed, since the tightening device can be inserted into the groove 35 to work, the fracture is not easy to break when screwing into the bone, the safety performance is improved, and the degradation is uniform. Preferably, the cross section of the forming male die 13 is polygonal, the polygonal structure is arranged to facilitate rotation, the use is convenient and fast for a user, and the rotation process is stable. For example, the cross section of the forming punch 13 is a polygon, such as a triangle, a quadrangle (refer to fig. 2), a pentagon or a hexagon (refer to fig. 3), but not limited thereto. Since the groove 35 is formed by the forming punch 13 and has the same structure as the forming punch 13, the cross section of the groove 35 has a triangular, quadrangular, pentagonal or hexagonal structure. In this embodiment, the shape of the groove 35 is a quadrangle, but not limited thereto.

Referring to fig. 4-5, the magnesium screw 30 shown in fig. 2 is obtained without threads 37 (as shown in fig. 4) by means of the cooperation of the female die 11 and the molding male die 13, and the magnesium screw 30 can be used as a pin. If the magnesium screw 30 is required to be further provided with the thread 37 structure, the magnesium screw 30 can be machined to form the thread 3733 (refer to fig. 5) by using a numerical control machining technology, and the machining technology for the thread 37 is not described in detail herein. Referring to fig. 7, in order to reduce the manufacturing process and reduce the cost, a concave-convex structure 113 for forming the thread 37 may be disposed on the inner wall of the cavity 111, and the concave-convex structure 113 is disposed corresponding to the structure of the required thread 37, i.e., the thread 37 may be formed by the concave-convex structure 113 in the process of manufacturing the magnesium screw 30 by using the concave die 11 and the molding convex die 13. That is, in the process of the high-frequency vibration device 20 driving the forming punch 13 to act on the liquid magnesium metal material in the cavity 111, the thread 37 is formed by the concave-convex structure 113 in the process of preparing the magnesium screw 30 by using the concave die 11 and the forming punch 13. The specific size of the concave-convex structure 113 is not limited herein.

Compared with the prior art, the preparation method of the magnesium screw 30 for bone tissue fixation adopts the concave-convex mould 10 and prepares the magnesium screw 30 from the metal magnesium material by means of the high-frequency vibration device 20, and has the advantages of simple method, low cost and capability of realizing mass production. In the preparation process, the density of the magnesium screw 30 is improved through the action of the high-frequency vibration device 20, and the magnesium screw has good mechanical property and corrosion resistance and is slow in degradation rate after being implanted into a human body. Meanwhile, the magnesium screw 30 is provided with the groove 35 due to the action of the forming male die 13, so that the magnesium screw is not easy to break when screwed into a bone, and the safety performance of the magnesium screw can be improved.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, therefore, the present invention is not limited by the appended claims.

Claims

1. The preparation method of the magnesium screw for bone tissue fixation is characterized in that a concave-convex mold is adopted to prepare the magnesium screw, the concave-convex mold comprises a concave mold and a forming convex mold, and the concave mold is provided with an open conical mold cavity; the magnesium screw is provided with a first end and a second end, a groove is concavely arranged along the direction from the first end to the second end,

the preparation method comprises the following steps:

2. The method for preparing a magnesium screw for bone tissue fixation according to claim 1, wherein the depth of the molding punch protruding into the cavity is 4/5 times or less.

3. The method of preparing a magnesium screw for bone tissue fixation according to claim 1, wherein in the step (1), the heating means is any one selected from the group consisting of high frequency heating, heat-generating tube heating, electron beam heating, laser heating and steam heating.

4. The method of preparing a magnesium screw for bone tissue fixation according to claim 4, wherein the cooling in step (5) is performed by providing a cooling channel in the concave-convex mold, the channel containing water, oil or steam.

5. The method of preparing a magnesium screw for bone tissue fixation according to claim 1, wherein the cross-section of the molding punch is polygonal.

6. The method of preparing a magnesium screw for bone tissue fixation according to claim 1, wherein the cross-section of the groove is polygonal.

7. The method of preparing a magnesium screw for bone tissue fixation according to claim 1, wherein the magnesium screw is subjected to numerical control machining to form a thread.

8. The method of manufacturing a magnesium screw for bone tissue fixation according to claim 1, wherein a concave-convex structure for forming a thread is provided on an inner wall of the cavity.

9. The method for preparing a magnesium screw for bone tissue fixation according to claim 1, wherein in the step (4), the high frequency vibration device continues to add a portion of the liquid magnesium metal material into the cavity during operation.

10. A magnesium screw for bone tissue fixation, which is produced by the method for producing a magnesium screw for bone tissue fixation according to any one of claims 1 to 9.