TWI679004B - Easy-to-screw compression magnesium alloy screw having double screw threads - Google Patents

Abstract

The invention relates to an easily screwed double-threaded countersunk head pressurized magnesium alloy nail, which is made of a magnesium alloy and the surface is treated with a passivation step, including: a first thread segment, and a screw connected to the first end by one end. A threaded section and a second threaded section are connected to the other end of the screw. The first threaded section is provided with an operating hole, and the diameter of the first threaded section is larger than the diameter of the second threaded section. The magnesium alloy is Contains magnesium (Mg), zinc (Zn), zirconium (Zr), and calcium (Ca).

Description

Easy to screw into double thread countersunk head pressurized magnesium alloy nail

The invention relates to an easily screwed double-threaded countersunk head pressurized magnesium alloy nail including a cutting edge angle design, which is made of a magnesium alloy and the surface is treated with a passivation step. The first thread section and the second thread section are used for Used to connect and fix bone tissue at the fracture site.

In the past, in the treatment of fractures, a fixed bracket or bone nail was set outside the broken bone to fixedly connect the outside of the broken bone and allow the broken bone to grow; however, the fixed bracket or nail provided outside the bone still had contact with the skin or bone. It is not easy to take care of the wound, and it may cause the wounded person to have foreign body sensation and the inconvenience of movement. The intramedullary nail is a type of steel nail fixed in the bone marrow cavity of broken bones. Attach and fix broken bones to prevent bone rotation or shortening. The use of intramedullary nails produces smaller wounds and does not damage soft tissues to a large extent. Furthermore, intramedullary nails can help share the negative gravity of broken bones. The intramedullary nail has at least one thread to be screwed into the bone marrow, and the other end may be a nail head or provided with a second thread. For example, the invention patent No. TW I468145 (B) of the Republic of China relates to a headless compression screw with an integrated compression relief device, which includes a bone screw, a mounting device and a driving tool; the bone screw includes a The front end of the first threaded portion, a rear end of the second threaded portion, an unthreaded middle portion, and a longitudinal shaft; the mounting device has a distal end portion with an internal thread, and the internal thread and the second threaded portion of the bone screw Engagement; the driving tool system includes an engagement portion, and the engagement portion engages a receiving portion of the bone screw to rotate the bone screw. In addition, the Republic of China Patent No. TW M459839 (U) is a new type of patent. It is a bone screw structure. It is attached to the surface of a hollow bone nail to disjoint first and second threaded parts. The pitch of the second threaded part and the second threaded part are designed so that the gradually reduced pitch can provide good compression effect when engaging the bone; while the pitch changes, the second threaded part adjacent to the tail end of the bone nail body is changed The depth of the thread (thread) is gradually reduced, and the propulsion effect of the bone screw is assisted by a cone-like structure, thereby generating a higher thrust to restore the bone.

However, in addition to the structural design, the material or surface treatment of the medical material or bone screw is also very important, which also has an important impact on the characteristics of the medical material or bone screw; for example, Chinese Patent No. CN103826668 (B) Invention Patent Is about a method for producing medical implants using magnesium alloys; magnesium alloys used to make implants contain at least 80% by weight magnesium, especially at least 90%; magnesium alloys also contain 2.5 to 5% by weight Mixed rare earth metal containing neodymium, 1.5 to 5% by weight of hafnium, 0.1 to 2.5% by weight of zirconium, 0.1 to 0.8% by weight of zinc, and aluminum not exceeding 0.5% by weight; however, in this invention patent The content of rare earth elements is too high, and the toxicity of rare earth elements accumulates in the human body, and there are still high-risk doubts about the safety of the human body.

Today, the inventor is in view of the inadequacies of the existing bone nails in actual implementation, so he is a tireless spirit, supplemented by his rich professional knowledge and years of practical experience to develop the invention.

The invention provides an easily screwed double-threaded countersunk head pressurized magnesium alloy nail, which is made of a magnesium alloy and the surface is treated with a passivation step, including: a first thread segment, and a screw connected to the first thread at one end. And a second threaded segment connected to the other end of the screw, the first threaded segment is provided with an operating hole, and the diameter of the first threaded segment is greater than the diameter of the second threaded segment, wherein the magnesium alloy system contains Magnesium (Mg), zinc (Zn), zirconium (Zr) and calcium (Ca).

In one embodiment of the present invention, the first thread segment is provided with a plurality of first threads, and the second thread segment is provided with a plurality of second threads. The pitch of the plurality of first threads is smaller than the plurality of second threads. Of the pitch.

In one embodiment of the present invention, the magnesium alloy includes 4-6 wt% zinc, 0.2-0.6 wt% zirconium, 0.05-0.2 wt% calcium, and magnesium in the remaining weight percentage.

In one embodiment of the present invention, the passivation step is to process the easily screwed double-threaded countersunk head pressurized magnesium alloy nail in a nitrogen-containing atmosphere at 360 to 420 ° C for 2 to 4 hours, so as to easily screw into the double-threaded countersunk head A magnesium zinc oxide layer is formed on the surface of the pressed magnesium alloy nail.

In an embodiment of the present invention, at least a first edge is provided at the connection point between the screw and the first threaded section, and at least a second edge angle is provided at the other end of the connection end of the second threaded section and the screw.

In one embodiment of the present invention, the plurality of first threads are one of a triangular thread, a stepped thread or a serrated thread, and the plurality of second threads are a triangular thread or a ladder. Either thread or serrated thread.

In an embodiment of the present invention, a guide tube is provided inside the screw, and a hollow section is provided inside the second threaded section. One end of the guide tube is connected with the operation hole of the first threaded section. The other end of the pipe is interconnected with the hollow section of the second threaded section, wherein the inner diameter of the guide pipe and the hollow section is between 1.0 mm and 1.5 mm.

In one embodiment of the present invention, the guide pipe is a circular pipe or a polygonal pipe.

In this way, the double-threaded countersunk head pressurized magnesium alloy nail of the present invention has a double-threaded design, so that the present invention has a better compression effect on the fracture surface locked in the bone tissue, and the countersunk design can reduce foreign body sensation and Soft tissue interference; the hollow design makes the invention suitable for fine-needle anterior surgery. A thin needle is first penetrated through the affected part, and then the easy-screw double-threaded buried pressure magnesium alloy nail sleeve is placed outside the thin needle, and it is smooth. Use a fine needle to screw into the affected area. After the easy-screw double-threaded countersunk head pressurized magnesium alloy nail is fully screwed into the affected area, remove the fine needle to complete the fixation. The magnesium alloy material used is light in weight but similar in rigidity to human bones. It has high stability and good biocompatibility.

The purpose of the present invention and its structural and functional advantages will be explained based on the structure shown in the following drawings, in conjunction with specific embodiments, so that the reviewing committee can have a deeper and more specific understanding of the present invention.

The invention relates to a screwable double-threaded countersunk head pressurized magnesium alloy nail, which is made of a magnesium alloy and the surface is treated with a passivation step. In one embodiment of the present invention, it is used to manufacture the screwable double-threaded screw of the present case. The magnesium alloy material of the countersink pressurized magnesium alloy nails contains 4-6 wt% zinc, 0.2-0.6 wt% zirconium, 0.05-0.2 wt% calcium, and the remaining weight percentage of magnesium. In addition, the surface passivation step is performed on the surface. Easy-screw double-threaded countersunk head pressurized magnesium alloy nails are treated in a nitrogen-containing atmosphere by steaming at 360 ~ 420 ° C for 2 ~ 4 hours. Zinc layer.

Please refer to the first and second figures. The easy-screw double-threaded countersunk head pressurized magnesium alloy nail of the present invention includes a first thread segment (1), and a screw (2) is connected to the first thread segment (1) with one end. And a second threaded section (3) is connected to the other end of the screw (2); an operation hole (11) is provided in the first threaded section (1), and the diameter of the first threaded section (1) is larger than the second The diameter of the thread segment (3), in which the magnesium alloy system includes magnesium (Mg), zinc (Zn), zirconium (Zr) and calcium (Ca); the first thread segment (1) is provided with a plurality of first threads (12) ), And the second thread segment (3) is provided with a plurality of second threads (31), the pitch of the plurality of first threads (12) is smaller than the pitch of the plurality of second threads (31); in an embodiment The plurality of first threads (12) and the plurality of second threads (31) are one of a triangular thread, a stepped thread or a serrated thread.

Because the pitch of the plurality of first threads (12) of the first thread segment (1) is small, a large force is required when screwing into the place to be fixed. Therefore, the first thread segment (1) and the screw (2) The number of junctions is provided with at least a first cutting edge angle (13), so that the first thread segment (1) can be easily screwed into the position to be fixed, which has a labor-saving effect, and the first cutting edge angle (13) also prevents easy rotation in this case. The double-threaded countersunk head pressurized magnesium alloy nail reverses unscrewing during locking; in the embodiment of the first and second figures of this case, the first edge angle (13) presents a wing-like structure and has everything Edge area. A lead angle structure (21) is provided at the connection between the screw (2) and the first thread segment (1), and the lead angle structure (21) can strengthen the connection structure between the first thread segment (1) and the screw (2). In addition, the other end of the connecting end of the second thread segment (3) and the screw (2) is provided with at least a second cutting edge angle (32) to assist the second thread segment (3) to be screwed into the position to be fixed. In the embodiment shown in the figures and the second figure, the second cutting edge (32) of the present case has a tip portion and an oblique cutting edge portion. As the surface of the screwed magnesium alloy nail with easy screwing into the double-threaded countersunk head in this case is passivated and covered with a zinc-magnesium oxide layer, it can reduce the frictional force when screwing into the part to be fixed and screw it into the to-be-fixed with a small torque. The location.

In addition, a guide tube (22) is provided inside the screw (2) of the present invention which is easily screwed into a double-threaded countersunk head pressurized magnesium alloy nail, and one end of the guide tube (22) and the operation hole (11) are mutually connected, and the guide tube ( 22) The other end is internally connected with a hollow section (33) of the second thread section (3); the inner diameter of the guide tube (22) and the hollow section (33) is between 1.0 mm and 1.5 mm. The guide tube (22) may be a circular tube or a polygonal tube.

Please refer to the third figure. In use, the case is first screwed into the second threaded section (3) of the double-threaded countersunk head pressurized magnesium alloy nail and locked into the bone tissue (4) to be fixed. Double-threaded countersunk head pressurized magnesium alloy nail is locked in; please refer to FIG. 4 again, the easy-screwable dual-threaded countersunk head pressurized magnesium alloy nail can be completely locked into the bone tissue, and the first thread section (1) thereof can be completely embedded in the bone. Within organization (4). In addition, the screwed double-threaded countersunk head pressurized magnesium alloy nails in this case are biodegradable magnesium alloy nails, which will gradually decompose within 3 months after being implanted into the bone tissue (4); The screw thread part of the nail will first generate an ion reaction and degrade first. After the degradation, the surface of the thread part that was originally smooth will become dimples and the friction will increase, making it easier to loosen or withdraw; and the first edge angle ( 13) If it is degraded, the phenomenon that the screwed magnesium alloy nail easily screwed into the double-threaded countersunk head in the present case is reversed and unscrewed can be further reduced.

In summary, compared with the prior art, the easy-screw double-threaded countersunk head pressurized magnesium alloy nail of the present invention has the following advantages:

1. The double-threaded countersunk head pressurized magnesium alloy nail of the present invention has a first threaded section and a second threaded section. The design of the double thread makes the invention have a better compression effect on the fracture surface locked in the bone tissue. In order to effectively assist the recovery of bone tissue; in addition, after the locking is completed, the end face of the threaded section does not protrude from the bone surface, but presents a smooth state with the bone surface. This countersunk design can reduce foreign body sensation and soft tissue interference.

2. The invention is an easy-to-screw double-threaded countersunk head pressurized magnesium alloy nail, which is a hollow design pressure nail suitable for fine-needle anterior surgery; in addition, the invention can also be directly applied to fractures of fingers or toes without the need for a spinal cord. For nails or bone plates.

3. The invention is easy to screw into a double-threaded countersunk head pressurized magnesium alloy nail, which is made of magnesium alloy, is light in weight and rigid, is similar to human bone, and is not easy to deform, has high stability, corrosion resistance, and good biocompatibility; In addition, the zinc element contained in the easy-screw double-threaded countersunk head pressurized magnesium alloy nail also has important functions for the human body and is an essential element. Therefore, after the magnesium alloy nail is implanted and degraded, the components contained in the magnesium alloy nail are important to the human body. With low toxicity, it has high safety in the manufacture of medical materials.

In summary, the easy-screw double-threaded countersunk head pressurized magnesium alloy nail of the present invention can indeed achieve the expected use effect through the above-disclosed embodiment, and the present invention has not been disclosed before the application. Fully in line with the provisions and requirements of the Patent Law. I filed an application for an invention patent in accordance with the law, and I urge you to examine it and grant the patent.

However, the illustrations and descriptions disclosed above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Anyone who is familiar with the technology, according to the characteristic scope of the present invention, makes other Equivalent changes or modifications should be regarded as not departing from the design scope of the present invention.

(1) ‧‧‧First thread section

(11) ‧‧‧Operation hole

(12) ‧‧‧First screw

(13) ‧‧‧First Blade Angle

(2) ‧‧‧Screw

(21) ‧‧‧Lead angle structure

(22) ‧‧‧Guide tube

(3) ‧‧‧Second thread section

(31) ‧‧‧Second screw

(32) ‧‧‧Second Blade Angle

(33) ‧‧‧Hollow section

(4) ‧‧‧ Bone Tissue

The first picture: the three-dimensional schematic diagram of this case easy to screw double-thread countersunk head pressurized magnesium alloy nail.

The second picture: a cross-sectional view of the case with a screwed double-threaded countersunk head pressurized magnesium alloy nail.

The third picture: the schematic diagram of the action of the screwed double-threaded countersunk head pressurized magnesium alloy nail in this case (1).

Figure 4: Schematic diagram of the action of a double-threaded countersunk head pressurized magnesium alloy nail in this case (2).

Claims (7)

An easily screwed double-threaded countersunk head pressurized magnesium alloy nail is made of a magnesium alloy and the surface is treated with a passivation step, including: a first thread segment, a screw connected to the first thread segment with one end, and A second threaded segment is connected to the other end of the screw, an operating hole is provided in the first threaded segment, and a diameter of the first threaded segment is greater than a diameter of the second threaded segment, wherein the magnesium alloy system contains 4 to 6 wt. % Zinc (Zn), 0.2 ~ 0.6wt% zirconium (Zr), 0.05 ~ 0.2wt% calcium (Ca), and the remaining weight percentage of magnesium (Mg), wherein the passivation step is the easy screwing into the double thread The countersunk head pressurized magnesium alloy nail is treated at 360 to 420 ° C for 2 to 4 hours in a nitrogen-containing atmosphere, so that a magnesium oxide zinc layer is formed on the surface of the easily screwed double-threaded countersunk head pressurized magnesium alloy nail. The easy-screw double-threaded countersunk head pressurized magnesium alloy nail according to item 1 of the scope of the patent application, wherein the first thread segment is provided with a plurality of first threads and the second thread segment is provided with a plurality of second threads. The pitch of the plurality of first threads is smaller than the pitch of the plurality of second threads. The easy-screw double-thread countersunk head pressurized magnesium alloy nail according to item 1 of the scope of the patent application, wherein at least one first cutting edge angle is provided at the connection between the screw and the first thread section, and the at least first cutting edge system is To prevent the easily screwed double-thread countersunk head pressurized magnesium alloy nail from rotating backward. According to the easy-screw double-threaded countersunk head pressurized magnesium alloy nail described in item 1 of the scope of the patent application, the second thread segment and the other end of the connecting end of the screw are provided with at least a second edge angle. The easy-screw double-threaded countersunk head pressurized magnesium alloy nail according to item 2 of the scope of the patent application, wherein each of the plurality of first threads is one of a triangular thread, a stepped thread or a serrated thread Each of the plurality of second threads is one of a triangular thread, a stepped thread, or a serrated thread. According to item 1 of the scope of the patent application, the screw-in double-thread countersunk head pressurized magnesium alloy nail is provided with a guide tube inside the screw, and a hollow section is provided inside the second thread section, and one end of the guide tube is connected with the The operation holes of the first threaded section penetrate each other, and the other end of the guide tube and the hollow section of the second threaded section communicate with each other, wherein the inner diameter of the guide tube and the hollow section is between 1.0 mm and 1.5 mm. The easy-screw double-threaded countersunk head pressurized magnesium alloy nail according to item 6 of the patent application scope, wherein the guide pipe is a circular pipe or a polygonal pipe.