Biomedical degradable pure magnesium screw

Abstract

The invention discloses a biomedical degradable pure magnesium screw, and belongs to the technical field of screws for fracture. The device comprises a fixing screw, and a telescopic assembly and an energy storage assembly are arranged in the fixing screw. And the fixing screws are used for connecting fracture sections. The telescopic assembly can protrude out of the side face of the fixing screw. The energy storage assembly can provide force for the telescopic assembly to protrude the fixing screw in a delayed mode, so that the telescopic assembly can automatically stretch out. The fixing screw and the telescopic assembly are made of pure magnesium materials with the purity not lower than 99.99 wt.%. And the energy storage assembly is made of a material which can be absorbed by a human body. By arranging the telescopic assembly, the telescopic assembly can protrude from the side face of the fixing screw, the telescopic assembly fixedly protrudes from the side face, the firmness of the fixing screw is improved, and meanwhile the fixing screw can be prevented from spinning. Thus, the length of the fixing screw is reduced, a good fixing effect can be achieved, and the sections are firmly connected.

Description

Technical Field

[0001] The invention relates to the technical field of screws for fractures, and in particular to a biomedical degradable pure magnesium screw. Background Art

[0002] A fracture is a complete or partial break in a bone or bone structure. There are two types of fractures: stable fractures and unstable fractures. Among them, a stable fracture is one in which the fracture ends are not easily displaced or are not easily displaced again after reduction, such as a crack fracture, greenstick fracture, transverse fracture, compression fracture, impacted fracture, etc. An unstable fracture is one in which the fracture ends are easily displaced or are easily displaced again after reduction, such as an oblique fracture, spiral fracture, comminuted fracture, etc.

[0003] Since the fracture ends of unstable fractures are prone to displacement when subjected to external forces, it is difficult to maintain the stability of the fracture ends by external fixation alone. In order to ensure smooth fracture healing and recovery of limb function, it is usually necessary to insert screws for internal fixation to provide more reliable stability and prevent the fracture ends from displacing again.

[0004] Usually the screws are fixed perpendicular to the cross section. Figure 1 Taking oblique fracture as an example, the bone after fracture forms upper broken bone 100 and lower broken bone 500. The cross sections of the upper broken bone 100 and the lower broken bone 500 are first spliced ​​together and then fixed with screws. Before connecting the screws, it is necessary to drill the corresponding screw holes with an electric drill, and then screw in the screws. According to the distribution position of the drill holes, the first screw hole 200, the second screw hole 300, the third screw hole 400 and the fourth screw hole 600 are commonly used. Among them, the first screw hole 200 and the second screw hole 300 are mainly used to fix the outer position of the broken bone, and the third screw hole 400 is used to fix the middle position of the broken bone. When the width of the bone is wider, the third screw hole 400 needs to be set to increase the stability of the fixation. However, the screw hole length of the third screw hole 400 is longer, which will damage more normal bones, and requires a longer long screw. The long screw will also produce stress shielding, which is not conducive to bone recovery. In order to overcome the disadvantages of the third screw hole 400, a fourth screw hole 600 is provided. The fourth screw hole 600 is a blind hole opened in the cross section of the upper bone fragment 100 and the lower bone fragment 500, and then the two ends of the screw are respectively inserted into the blind holes on the cross sections of both sides. The fourth screw hole 600 does not need to destroy too much normal bone, and the screw in the fourth screw hole 600 can fix the upper bone fragment 100 and the lower bone fragment 500. However, the screw in the fourth screw hole 600 only connects the upper bone fragment 100 and the lower bone fragment 500 by plugging. The screw in the fourth screw hole 600 is easy to be misplaced during rotation, deviating from the original fixing point, causing the cross sections of the upper bone fragment 100 and the lower bone fragment 500 to deviate, which is not conducive to cross-section healing. Summary of the invention

[0005] In view of the above-mentioned shortcomings, the present invention provides a biomedical degradable pure magnesium screw, which can reduce and prevent the screw from loosening and rotating, and is helpful for the recovery of fracture patients.

[0006] The present invention protects a biomedical degradable pure magnesium screw, comprising a fixing screw, wherein a telescopic component and an energy storage component are provided in the fixing screw; The fixing screw is used to connect the fractured sections; The telescopic assembly can protrude from the side of the fixing screw; The energy storage component can provide the telescopic component with a force that delays the protrusion of the fixing screw, so that the telescopic component can automatically extend; The fixing screw and the telescopic component are both made of pure magnesium with a purity of not less than 99.99wt.%; the energy storage component is an elastic material that can be absorbed by the human body.

[0007] Furthermore, the fixing screw comprises a screw body, a hollow cavity is provided in the screw body, and the telescopic assembly is arranged in the hollow cavity; A telescopic channel is also provided in the screw body. The telescopic channel is radially arranged in the side wall of the screw body. The telescopic channel is communicated with the hollow cavity so that the telescopic assembly can extend from the telescopic channel.

[0008] Furthermore, a plurality of strip-shaped cavities are provided in the side wall of the screw body, and the plurality of strip-shaped cavities are distributed along the circumferential direction; Each of the strip-shaped cavities is a closed cavity extending along the vertical direction.

[0009] Furthermore, adjacent strip-shaped cavities are connected via connecting channels.

[0010] Furthermore, a convex portion is provided on the side wall surface of the screw body, and the convex portion forms an external thread; The top surface of the screw body is provided with a slot.

[0011] Furthermore, the telescopic assembly comprises a rotatable rotating rod and a slider sleeved on the rotating rod, and the slider can move along the axial direction of the rotating rod; The slider is hinged to one end of the connecting rod, and the other end of the connecting rod is hinged to the fixing block; The rotating rod is provided with a clamping piece, and the energy storage assembly can be clamped with the clamping piece to drive the rotating rod to rotate.

[0012] Furthermore, a notch is provided on the top side wall of the rotating rod, and the engaging member is the notch; The top surface of the rotating rod is provided with a transverse groove.

[0013] Further, the energy storage assembly comprises an elastic member and a base, one end of the elastic member is fixed on the fixing screw, and the other end of the elastic member is a free end, and the free end can be engaged with the engaging member; The elastic member can be deformed; The base can fix the deformed elastic member.

[0014] Furthermore, the elastic member is a spring, and a hook is provided on the free end of the spring; the spring is made of pure magnesium with a purity of not less than 99.99wt.%.

[0015] Furthermore, the base is an ice cube.

[0016] Beneficial effects: The present invention provides a telescopic component, which can protrude from the side of the fixing screw. The telescopic component protrudes from the side and abuts against the hole wall of the screw hole, that is, the bone, thereby increasing the firmness of the fixing screw and preventing the fixing screw from spinning. This can achieve a good fixing effect and make the cross section firmly connected. By providing an energy storage component, the fixing screw can be directly applied to the cross section, that is, the fourth screw hole. After the fixing screw is placed in the fourth screw hole, the energy storage component provides a delayed force to the telescopic component, so that the telescopic component extends, achieves fixation, and prevents the cross section from moving. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] in: Figure 1 It is a schematic diagram of an oblique fracture in the background technology of the present invention; Figure 2 This is a schematic diagram of the overall structure of a biomedical degradable pure magnesium screw in one embodiment of the present invention; Figure 3 A top view of a biomedical degradable pure magnesium screw according to an embodiment of the present invention; Figure 4 for Figure 3 Cross-section in the AA direction; Figure 5 A partial cross-sectional view of a biomedical degradable pure magnesium screw in one embodiment of the present invention; Figure 6 This is a front view of a biomedical degradable pure magnesium screw in one embodiment of the present invention; Figure 7 for Figure 6Cross-section in CC direction; Figure 8 A top view of a biomedical degradable pure magnesium screw in another embodiment of the present invention; Fig. 9 for Figure 8 Cross-section in the middle DD direction; Fig.10 is a cross-sectional view of a fixing screw in another embodiment of the present invention; Fig.11 It is a schematic diagram of the overall structure of a telescopic assembly in one embodiment of the present invention; Fig.12 It is a schematic diagram of the overall structure of an energy storage assembly in one embodiment of the present invention; In the figure, 1, fixing screw; 11, screw body; 12, strip cavity; 13, connecting channel; 14, raised portion; 15, bottom groove; 16, hollow cavity; 161, central cavity; 162, side cavity; 17, telescopic channel; 18, top groove; 19, straight groove; 2. telescopic assembly; 21. rotating rod; 211. notch; 212. transverse groove; 22. slider; 23. connecting rod; 24. fixing block; 3. Energy storage component; 31. Spring; 311. Hook; 32. Base; 100, upper bone fragment; 200, first screw hole; 300, second screw hole; 400, third screw hole; 500, lower bone fragment; 600, fourth screw hole. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Figure 1 Taking the oblique fracture of the leg bone as an example, the upper broken bone 100 and the lower broken bone 500 are spliced ​​together, and then screw holes are drilled and screws are inserted into the screw holes. The screw holes cannot be directly seen from the outside, so the first screw hole 200, the second screw hole 300, the third screw hole 400 and the fourth screw hole 600 are indicated by dotted lines.

[0021] refer to Figure 1 to Figure 12 The present invention protects a biomedical degradable pure magnesium screw, which includes a fixing screw 1, in which a telescopic component 2 and an energy storage component 3 are arranged.

[0022] The fixing screw 1 is used to connect the fractured sections. The fixing screw 1 has the same function as the conventional fracture screws, which are perpendicular to the sections to connect and fix the sections. Figure 1 The fourth screw hole 600 is located in the middle to connect the upper bone fragments 100 and the lower bone fragments 500.

[0023] The telescopic component 2 can protrude from the side of the fixing screw 1. The purpose of the telescopic component 2 protruding from the fixing screw 1 is to prevent the fixing screw 1 from spinning and fix the cross section from different angles.

[0024] The energy storage component 3 can provide the telescopic component 2 with a force to protrude the fixing screw 1, so that the telescopic component 2 can automatically extend; The fixing screw 1 and the telescopic component 2 are made of pure magnesium with a purity of not less than 99.99wt.%; the energy storage component 3 is made of a material that can be absorbed by the human body. The absorbable material can be a degradable metal, such as pure magnesium material, or water, inorganic salts and other substances that can be absorbed by the human body.

[0025] The present invention provides a telescopic component 2, which can protrude from the side of the fixing screw 1. The telescopic component 2 protrudes from the side and abuts against the hole wall of the fourth screw hole 600, that is, the bone, thereby increasing the firmness of the fixing screw 1 and preventing the fixing screw 1 from spinning. In this way, a good fixing effect can be achieved, and the cross section can be firmly connected. By providing an energy storage component 3, the fixing screw 1 can be directly applied to the cross section, that is, Figure 1 The fourth screw hole 600 in the bone. After the two ends of the fixing screw 1 are respectively inserted into the blind holes on the upper broken bone 100 and the lower broken bone 500, the cross-sections of the upper broken bone 100 and the lower broken bone 500 are aligned. After that, the energy storage component 3 provides a delayed force to the telescopic component 2, so that the telescopic component 2 is extended to achieve fixation and prevent the cross-section from moving. There are two purposes for setting the energy storage component 3. The first purpose is to drive the telescopic component 2 to extend, because after the fixing screw 1 is placed in the fourth screw hole 600 and the cross-sections of the upper broken bone 100 and the lower broken bone 500 are aligned, the fixing screw 1 is already inside the bone, and the doctor cannot operate from the outside. The energy storage component 3 can replace the doctor to drive the telescopic component 2 to extend, so that the fixing screw 1 is firmly set in the screw hole of the fourth screw hole 600. The second purpose is to delay the release of the driving force to ensure that the doctor places the fixing screw 1 in the screw hole, and then releases the driving force to extend the telescopic component 2. Of course, the time for the energy storage component 3 to delay the release of the force is within a certain known time range, and the doctor can place the fixing screw 1 within this time.

[0026] By selecting the fixing screw 1 and telescopic component 2 made of pure magnesium material, magnesium is one of the essential elements of the human body and is involved in many physiological processes of the human body, such as cell metabolism, energy transfer and bone mineralization. The magnesium ions released by the pure magnesium screw after degradation in the body can be absorbed and utilized by the human body, and will not cause immune rejection or other harmful physiological reactions. The elastic modulus of pure magnesium screws is about 41-45GPa, which is closer to the elastic modulus of human bone tissue (15-40GPa). It can better realize stress transmission during fracture healing, reduce the occurrence of stress shielding, avoid complications such as osteoporosis, bone resorption and implant loosening caused by stress shielding, and is conducive to bone tissue healing and remodeling at the fracture site.

[0027] refer to Figure 4 , Figure 5 , Figure 6 , Fig. 9 Fig.10 In a specific embodiment, the fixing screw 1 includes a screw body 11, a hollow cavity 16 is provided in the screw body 11, and a telescopic assembly 2 is provided in the hollow cavity 16. The axis of the hollow cavity 16 coincides with the axis of the screw body 11.

[0028] The screw body 11 is further provided with a telescopic channel 17, which is radially arranged in the side wall of the screw body 11, and is communicated with the hollow cavity 16, so that the telescopic assembly 2 can be extended from the telescopic channel 17. Specifically, the telescopic channel 17 is arranged in the side wall between the hollow cavity 16 and the outer surface of the screw body 11. The axis of the telescopic channel 17 is perpendicular to the axis of the hollow cavity 16.

[0029] By providing the telescopic channel 17 , part of the telescopic component 2 can be extended along the radial direction of the screw body 11 , and the extended part of the telescopic component 2 abuts against the wall of the screw hole to prevent the screw body 11 from spinning.

[0030] refer to Figure 4 or Fig. 9 In a specific embodiment, a plurality of strip-shaped cavities 12 are provided in the side wall of the screw body 11, and the plurality of strip-shaped cavities 12 are distributed along the circumferential direction; each strip-shaped cavity 12 is a closed cavity extending along the vertical direction.

[0031] The strip cavity 12 provided in this embodiment has three functions. The first function is to reduce the elastic modulus of the screw body 11. The elastic modulus of a pure magnesium screw is about 41~45GPa. Although it is close to the elastic modulus of human bone tissue of 15~40GPa, it is still higher than the elastic modulus of human cancellous bone. By providing a plurality of strip cavities 12, the elastic modulus of the screw body 11 can be effectively reduced, so that the elastic modulus of the screw body 11 is close to the elastic modulus of human bone tissue, which is conducive to the recovery of the fracture position. The second function is to enhance the stability of fixation. Existing pure magnesium screws loosen during the degradation process. In this embodiment, by providing a strip cavity 12, after the outer surface of the screw body 11 is degraded, a hollow structure is formed at the strip cavity 12, and the surrounding bone tissue gradually grows into the hollow structure, which can further enhance the bonding force between the screw and the bone tissue and improve the long-term stability of the fixation. The third function is to promote the growth of bone tissue. The strip cavity 12 provides more space and channels for the growth of bone tissue, which is conducive to the migration, proliferation and differentiation of surrounding bone cells, accelerates the growth of bone tissue on the surface and inside of the screw body 11, and makes the screw body 11 and bone tissue better integrated together to form a stronger bone-screw complex, thus promoting the healing of fractures. At the same time, certain ions or products released by the degradable material during the degradation process, such as magnesium ions and alkaline microenvironment, may also have the effect of stimulating bone cell activity and promoting bone formation.

[0032] In a specific embodiment, individual strip cavities 12 are filled with bone support materials. A degradable porous composite scaffold material for bone transplantation with application number 201610025098.5 can be added. The material has a natural bone mineral three-dimensional interconnected mesh microstructure and good mechanical strength. At the same time, whiskers with a large aspect ratio grow in the mesh, which can increase the specific surface area of ​​the material, relatively adjust the micropore diameter and improve cell adhesion, and also have good degradability. It can better restore the fracture position. A degradable porous scaffold material for guiding bone tissue regeneration and repair with application number 200810058677.5 can also be added. The material is a multifunctional material that can promote and induce bone tissue repair, antibacterial, and has an adjustable degradation rate in the body. Setting this material can adjust different degradation rates according to different stages of bone recovery, which can provide support and have a certain degradation rate. A drug-loaded bone repair internal fixation material with application number 202110785442.1 can also be added. This material can achieve sustained release of drugs without affecting the morphology and properties of the material.

[0033] refer to Figure 4 , Figure 5 , Figure 7 , Fig. 9 or Fig.10In a specific embodiment, adjacent strip-shaped cavities 12 are connected through connecting channels 13. By providing connecting channels 13, the connectivity of adjacent strip-shaped cavities 12 is increased. The irregularity of the hollow structure is increased. Bone tissue can grow into the connecting channels 13, thereby increasing firmness.

[0034] refer to Figure 2 , Figure 5 , Figure 6 or Fig.10 In a specific embodiment, a protrusion 14 is provided on the side wall surface of the screw body 11, and the protrusion 14 forms an external thread. The position of the external thread is set according to actual needs. Figure 2 For example, the external thread can be provided at the bottom of the screw body 11, and no thread is provided at the top of the screw body 11. In this way, when the screw body 11 is placed at the position of the fourth screw hole 600, the bottom end of the screw body 11 can be screwed into one side section, the top end of the screw body 11 can be inserted into the other side section, and then the telescopic component 2 is extended to fix it. Of course, the external thread can also be provided on the entire side of the screw body 11, and it can be provided more densely or more sparsely according to actual needs. A straight groove 19 is provided on the top surface of the screw body 11. The purpose of the straight groove 19 is to screw the screw body 11 so that the screw body 11 can enter the screw hole.

[0035] In this embodiment, the protrusions 14 are arranged at different positions to form different thread forms, which can be applied to fracture sections at different positions and in different states, making the screw fixation more secure.

[0036] refer to Figure 4 , Figure 5 , Fig. 9 or Fig.11 In a specific embodiment, the telescopic assembly 2 includes a rotatable rotating rod 21 and a slider 22 sleeved on the rotating rod 21, and the slider 22 can move along the axial direction of the rotating rod 21. The rotating rod 21 is composed of a cylindrical top block and a screw-shaped rod body, the body is an externally threaded rod, and the slider 22 has an internally threaded hole. The rotating rod 21 can drive the slider 22 to rise or fall when it rotates.

[0037] The slider 22 is hinged to one end of the connecting rod 23, and the other end of the connecting rod 23 is hinged to the fixing block 24. Fig.11 , the connecting rod 23 can move slightly in the vertical direction and lock in the horizontal direction to achieve hinged connection. In this way, it can be ensured that the slider 22 can pull or push the fixed block 24 when moving along the vertical direction. Among them, the fixed block 24 is composed of a cylindrical body and a conical fixed end to form a bullet-shaped shape. The cylindrical body is connected to the connecting rod 23, and the fixed end can protrude from the screw body 11. The conical fixed end can abut against the wall of the screw hole, so that the screw body 11 is firmly set in the screw hole to prevent the screw body 11 from spinning.

[0038] The rotating rod 21 is provided with a clamping piece, and the energy storage assembly 3 can be clamped with the clamping piece to drive the rotating rod 21 to rotate. In this embodiment, by providing the clamping piece, the energy storage assembly 3 can transmit force to the rotating rod 21, so that the rotating rod 21 rotates, and then the slider 22 pushes the fixing block 24 to protrude from the screw body 11.

[0039] refer to Fig. 9 and Fig.10 In a specific embodiment, a top groove 18 is provided on the top surface of the screw body 11 , and the top groove 18 is used to accommodate the top block of the rotating rod 21 and the energy storage assembly 3 .

[0040] A bottom groove 15 is provided on the bottom surface of the hollow cavity 16. The inner wall of the bottom groove 15 is a smooth inner wall. The bottom groove 15 is used to accommodate the bottom end of the rotating rod 21 so that the rotating rod 21 can rotate relative to the bottom groove 15. In this way, the rotating rod 21 can stably rotate around its own axis without the rotating rod 21 itself rising or falling. Fig.10 , the hollow cavity 16 includes a central cavity 161 and a side cavity 162. Among them, the axis of the central cavity 161 coincides with the axis of the screw body 11. The side cavity 162 is opened on the side wall of the central cavity 161. The side cavity 162 is provided to accommodate the fixed block 24, so that the fixed block 24 can be fitted in the side cavity 162 when it is retracted; secondly, it is for limiting. When the fixed block 24 is extended, the side cavity 162 can assist in limiting the extension trajectory of the fixed block 24, so that the fixed block 24 can be accurately extended from the telescopic channel 17. Since the movement amplitude of the fixed block 24 is large, in order to ensure that the fixed block 24 can be smoothly extended, a chamfer is provided at one end of the telescopic channel 17 close to the hollow cavity 16.

[0041] refer to Fig.11 In a specific embodiment, a notch 211 is provided on the top side wall of the rotating rod 21, and the engaging member is the notch 211. Specifically, a notch 211 is provided on the side wall of the top block of the rotating rod 21. By providing the notch 211 on the side wall of the top block, it is convenient to directly convert the force provided by the energy storage assembly 3 into a tangential force, so that the rotating rod 21 can rotate and the slider 22 can rise to push the fixed block 24 out of the telescopic channel 17.

[0042] The top surface of the rotating rod 21 is provided with a transverse groove 212. The transverse groove 212 has two functions. The first function is to manually apply external force to make the fixed block 24 extend. Figure 1In this embodiment, rotating the rotating rod 21 clockwise can extend the fixed block 24, and rotating the rotating rod 21 counterclockwise can retract the fixed block 24. When the fixing screw 1 is placed at the position of the first screw hole 200, a clockwise rotation force can be manually applied through the transverse groove 212 to extend the fixed block 24. The second function is to store energy for the energy storage component 3. Rotating the rotating rod 21 counterclockwise can store energy for the energy storage component 3, and the fixing screw 1 enters the human body and releases force, causing the rotating rod 21 to rotate clockwise.

[0043] refer to Figure 2 and Fig.12 In a specific embodiment, the energy storage assembly 3 includes an elastic member and a base 32, one end of the elastic member is fixed to the fixing screw 1, and the other end of the elastic member is a free end, which can be engaged with the engaging member. Specifically, one end of the elastic member is fixed to the side wall of the top groove 18, and the free end of the elastic member is connected to the notch 211.

[0044] The elastic member can be deformed and can be selected as a spring, a spring, a spring, etc.

[0045] The base 32 can fix the deformed elastic member. The base 32 can be an ice cube. First, the free end of the elastic member is pulled to deform the elastic member to store energy, and then the deformed elastic member is immersed in liquid water to freeze into an ice cube as the base 32. At this time, the elastic member is also fixed. After the ice cubes are absorbed, the elastic member releases its force, pulling the rotating rod 21 to rotate.

[0046] This embodiment is convenient for energy storage by setting the elastic member, and has high stability and low failure rate. By setting the base 32, any state of the elastic member can be selected for fixation, and corresponding energy storage can be performed according to the actual fracture situation to complete the extension of the fixing member 24.

[0047] refer to Fig.12 In a specific embodiment, the elastic member is a spring 31, and a hook 311 is provided on the free end of the spring 31; the spring 31 is made of pure magnesium with a purity of not less than 99.99wt.%. The spring 31 can be selected with different lengths and widths according to actual needs.

[0048] The embodiment has the advantage of providing the spring 31, which is in the shape of a disk and has a circumferential elastic force, which is more conducive to the rotation of the rotating rod 21. One end of the spring 31 is fixed to the inner wall of the top groove 18, and the free end of the spring 31 can be rotated to store energy.

[0049] refer to Fig. 9 , Fig.10 and Fig.12In a specific embodiment, the base 32 is preferably an ice cube. The ice cube is an ice cube frozen by sterile physiological saline. In actual use, the hook 311 of the spring 31 is engaged with the notch 211. Then, the rotating rod 21 is twisted with a screwdriver to pull the spring 31 to store energy, and the screwdriver is fixed externally. Finally, after pouring physiological saline into the top groove 18, it is frozen in a sterile environment to form ice cubes. The ice cube serves as the base 32, and the ice cube can fix the spring 31 well. After the base 32 is taken out, the screwdriver is removed, and the fixing screw 1 can be used for the fracture site.

[0050] Of course, it should be noted that, considering the energy loss, the extension length of the fixing block 24 is set with a margin, for example, Fig. 9 When the middle spring 31 is not charged, the fixing block 24 is fully extended. When the spring 31 is charged and then released, the fixing block 24 can be extended a little bit to contact the bone. Fig. 9 For example, assuming that the fully extended length of the fixing block 24 is 20 mm, after the screwdriver turns the rotating rod 21, pulls the spring 31 to store energy, and then releases it, the extended length of the fixing block 24 may be 12 mm, and it can also work at this time. Therefore, this embodiment is feasible.

[0051] In addition, the hook 311 and the notch 211 are detachably connected. The hook 311 and the notch 211 can be separated first, and then the rotating rod 21 is twisted so that the fixing block 24 is about to extend from the side wall of the screw body 11, and finally the hook 311 is connected to the notch 211 to form an ice cube base.

[0052] The diameter of the top block of the rotating rod 21 is the same as the inner diameter of the hollow cavity 16 or the diameter of the top block of the rotating rod 21 is slightly smaller than the inner diameter of the hollow cavity 16. In this way, physiological saline does not enter or only enters a small part of the hollow cavity 16, and auxiliary fixation is achieved after being frozen into ice cubes.

[0053] The base 32 in this embodiment is an ice cube, which has a strong fixing force and can effectively fix the spring 31. After the fixing screw 1 is placed in the fracture, the body temperature of the person can melt the ice cube, so that the elastic force of the spring 31 is released, so as to pull the rotating rod 21 to rotate. The ice cube has the advantages of fast melting speed and harmlessness to the human body. Moreover, the melting of the ice cube can achieve delayed release of the elastic force of the spring 31. In addition, the melting time of a specific volume of ice cube is within a measurable range, so that the doctor can place the fixing screw 1 according to the melting time of the ice cube to prevent the telescopic component 2 from extending too early.

[0054] Considering that water will corrode when in contact with the magnesium screw body 11, a waterproof layer can be provided on the inner surface of the top groove 18, and the waterproof layer can prevent or reduce water from directly contacting the magnesium nail body 11. Among them, the waterproof layer can be made of polylactic acid (PLA) or polyglycolic acid (PGA). Polylactic acid (PLA) is a biodegradable thermoplastic polyester. In the natural environment or in the human body, polylactic acid can be gradually degraded into carbon dioxide and water through hydrolysis and enzymolysis, and finally absorbed or excreted by the body through metabolism of the organism, and will not cause long-term environmental pollution and residual problems in the body like traditional plastics. Polyglycolic acid (PGA) has excellent biodegradability. Polyglycolic acid can be enzymolyzed or hydrolyzed into carbon dioxide and water in the body, and finally excreted from the body, and will not leave long-term harmful residues in the environment or the human body, which gives it great advantages in the fields of biomedicine and environmental protection.

[0055] The fixing screw 1 of the present invention can be applied to multiple positions. Figure 1 For example, the fixing screw 1 can be set at the position of the fourth screw hole 600. In this way, the energy storage component 2 needs to store energy. After the fixing screw 1 is placed at the position of the fourth screw hole 600, the fixing block 24 can be extended with a delay to prevent the fixing screw 1 from rotating, so that the fixing screw 1 can firmly connect the upper bone fragments 100 and the lower bone fragments 500. Of course, the fixing screw 1 can also be set at the position of the first screw hole 200 in the figure like an ordinary screw. At this time, there is no need for the energy storage component 3 to store energy. First, screw the fixing screw 1 into the bone, and then screw the rotating rod 21 through the transverse groove 212 to extend the fixing block 24 to prevent rotation.

[0056] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A biomedical degradable pure magnesium screw, characterized in that: It comprises a fixing screw (1), wherein a telescopic component (2) and an energy storage component (3) are arranged inside the fixing screw (1); The fixing screw (1) is used to connect the fractured sections; The telescopic assembly (2) can protrude from the side of the fixing screw (1); The energy storage component (3) can provide the telescopic component (2) with a force that delays the protrusion of the fixing screw (1), so that the telescopic component (2) can automatically extend; The fixing screw (1) and the telescopic component (2) are both made of pure magnesium with a purity of not less than 99.99 wt.%; the energy storage component (3) is an elastic material that can be absorbed by the human body.

2. The biomedical degradable pure magnesium screw according to claim 1, characterized in that: The fixing screw (1) comprises a screw body (11), a hollow cavity (16) is provided in the screw body (11), and the telescopic assembly (2) is arranged in the hollow cavity (16); A telescopic channel (17) is also provided in the screw body (11). The telescopic channel (17) is radially arranged in the side wall of the screw body (11). The telescopic channel (17) is communicated with the hollow cavity (16), so that the telescopic assembly (2) can extend from the telescopic channel (17).

3. The biomedical degradable pure magnesium screw according to claim 2, characterized in that: A plurality of strip-shaped cavities (12) are provided in the side wall of the screw body (11), and the plurality of strip-shaped cavities (12) are distributed along the circumferential direction; Each of the strip-shaped cavities (12) is a closed cavity extending in a vertical direction.

4. The biomedical degradable pure magnesium screw according to claim 3, characterized in that: Adjacent strip-shaped cavities (12) are connected via connecting channels (13).

5. The biomedical degradable pure magnesium screw according to claim 2, characterized in that: A protrusion (14) is provided on the side wall surface of the screw body (11), and the protrusion (14) forms an external thread; The top surface of the screw body (11) is provided with a slot (19).

6. The biomedical degradable pure magnesium screw according to claim 1, characterized in that: The telescopic assembly (2) comprises a rotatable rotating rod (21) and a slider (22) sleeved on the rotating rod (21), wherein the slider (22) is movable along the axial direction of the rotating rod (21); The sliding block (22) is hinged to one end of a connecting rod (23), and the other end of the connecting rod (23) is hinged to a fixing block (24); The rotating rod (21) is provided with a clamping piece, and the energy storage assembly (3) can be clamped with the clamping piece to drive the rotating rod (21) to rotate.

7. The biomedical degradable pure magnesium screw according to claim 6, characterized in that: A notch (211) is provided on the top side wall of the rotating rod (21), and the engaging member is the notch (211); The top surface of the rotating rod (21) is provided with a transverse groove (212).

8. The biomedical degradable pure magnesium screw according to claim 6, characterized in that: The energy storage component (3) comprises an elastic member and a base (32), one end of the elastic member is fixed to the fixing screw (1), and the other end of the elastic member is a free end, and the free end can be engaged with the engaging member; The elastic member can be deformed; The base (32) can fix the deformed elastic member.

9. The biomedical degradable pure magnesium screw according to claim 8, characterized in that: The elastic member is a spring (31), and a hook (311) is provided on the free end of the spring (31); the spring (31) is made of pure magnesium with a purity of not less than 99.99 wt.%.

10. The biomedical degradable pure magnesium screw according to claim 8, characterized in that: The base (32) is an ice cube.

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