Degradable orthopedic screw in-situ replacer

Abstract

The invention provides a degradable orthopedic screw in-situ replacer, and belongs to the technical field of orthopedic screw replacement. Comprising a replacement screw, a screw rod and a screw cap, the screw rod and the screw cap form the replacement screw, a hollow cavity is formed in the center of the replacement screw, a rapid dissolving supporting mechanism is fixedly embedded in the hollow cavity, a thread part is arranged at one end of the screw rod, and a dissolving groove communicated with the hollow cavity is formed in the other end of the screw rod; a mounting groove extending into the screw rod is formed in the side wall of the nut, an anti-falling piece is fixedly embedded in the mounting groove, the replacement screw comprises a magnesium alloy base material and a degradable outer-layer coating film fixed to the outer side of the magnesium alloy base material, and a stearic acid lipophilic layer is arranged between the magnesium alloy base material and the degradable outer-layer coating film. And a magnesium oxide layer is arranged on the outer side of the degradable outer coating film. The dissolution speed of the replacement screw in the human body is increased, and the problem that the dissolution speed of the replacement screw is too low, so that bone growth is affected is solved.

Description

Technical Field

[0001] The invention relates to the technical field of orthopedic screw replacement, and in particular to a degradable orthopedic screw in-situ replacer. Background Art

[0002] In orthopedic surgery, screws are often used to fix fracture sites to promote healing and stability. However, the removal of the screws may increase the risk of fractures at the nail hole, especially in elderly patients. This risk mainly stems from the following factors: Slow healing of nail holes: After the screws are removed, the bone needs time to heal the nail holes. However, due to osteoporosis and weakened healing ability in the elderly, the nail holes may heal slowly, increasing the risk of fractures; Formation of a sclerotic layer: Long-term screw compression may cause a sclerotic layer to form around the nail channel. This sclerotic layer will hinder the normal bone healing process and cause the nail holes to not heal for a long time. Osteoporosis: The elderly are often accompanied by osteoporosis, which leads to reduced bone strength, further increasing the possibility of fractures around the nail holes. Mechanical stress concentration: Due to changes in materials and structures, the nail hole location will become a stress concentration point, making it more likely to fracture under the action of external forces.

[0003] Chinese patent 201810531155.6 discloses a hook-type orthopedic screw, including a screw body, the screw body including a ball head and a screw part, the screw part having a hollow mounting cavity, the hollow mounting cavity being provided with a hook-type component capable of preventing the screw from moving, the hook-type component including a hook stop plate, a swivel pin and a spreading screw, the hook stop plates being a pair, fixed in the middle of the hollow mounting cavity, the two hook stop plates being connected by a swivel pin, and the two hook stop plates being able to rotate around the swivel pin, the spreading screw being correspondingly arranged above the hook stop plates, the top of the spreading screw being movably connected to the ball head, and the bottom end being against the two hook stop plates. The hook-type orthopedic screw is effectively combined with a special hook stop plate, a spreading screw and a screw part, which greatly improves the firmness of the screw when fixed to the bone surface, prevents the screw from loosening, moving, rotating, and nailing back during use, thereby ensuring the safety and reliability of the operation and reducing the pain of the patient.

[0004] Although the above technical solution can ensure the stability of orthopedic screws after being fixed in the human body, the screws need to be solid in design to achieve the positioning in the above technical solution. However, the screws need to be removed from the human body after use, which can easily cause secondary damage to the human body. At present, in order to replace traditional orthopedic screws, magnesium alloys are usually used to make screws. Magnesium alloys will be slowly absorbed in the human body, so there is no need to remove the screws. However, the recovery period of human orthopedics is generally between three months and six months, and the absorption rate of magnesium alloy screws is much slower than that of orthopedics. Therefore, the remaining screws will hinder the growth of bones, and the volume of the screws will decrease during the dissolution and absorption process, which is prone to loosening and falling off. Therefore, the present application provides a degradable orthopedic screw in situ replacer to meet the needs. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an in situ biodegradable orthopedic screw replacer to solve the existing problem that the recovery period of human orthopedics is generally between three months and six months, and the absorption rate of magnesium alloy screws is much slower than the recovery rate of orthopedics. Therefore, the residual screws will hinder the growth of bones, and the volume of the screws will decrease during the dissolution and absorption process, making them prone to loosening and falling off.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A degradable orthopedic screw in-situ replacer comprises a replacement screw and a screw rod and a nut constituting the replacement screw. A hollow cavity is provided at the center of the replacement screw, a quick-dissolving support mechanism is embedded and fixed in the hollow cavity, a threaded portion is provided at one end of the screw rod, and a dissolving groove connected to the hollow cavity is provided at the other end of the screw rod, a mounting groove extending into the screw rod is provided on the side wall of the nut, and an anti-slip component is embedded and fixed in the mounting groove.

[0008] Optionally, the replacement screw includes a magnesium alloy substrate and a degradable outer coating fixed on the outside of the magnesium alloy substrate, a stearic acid lipophilic layer is arranged between the magnesium alloy substrate and the degradable outer coating, and a magnesium oxide layer is arranged on the outside of the degradable outer coating.

[0009] Optionally, a tightening groove is formed on the side wall of the nut, and protrusions fixed to the inner wall of the installation groove are provided at both ends of the nut.

[0010] Optionally, the anti-slip component includes a connecting plate and an anti-slip portion and a fastening portion fixed at both ends of the connecting plate, and the anti-slip portion is obliquely arranged on the outer wall of the screw.

[0011] Optionally, the fastening portion is inserted into the nut, and a positioning hole larger than one-half of the structure is opened on the outer wall of the fastening portion, and the protrusion is spherical and snap-fitted into the positioning hole.

[0012] Optionally, the rapid dissolving support mechanism includes a load-bearing rod and a first supporting blade fixed to the outer wall of the load-bearing rod in a ring array, and both ends of the load-bearing rod are fixedly connected to the inner wall of the hollow cavity.

[0013] Optionally, a protrusion is fixed to the side walls of the plurality of first supporting blades, and the protrusion is tightly connected to the inner wall of the nut.

[0014] Optionally, the fast dissolving support mechanism includes support frames arranged in a ring array, both ends of the support frames are fixedly connected to the inner wall of the hollow cavity, and a honeycomb hole is opened at the center of the support frame.

[0015] Optionally, the fast-dissolving support mechanism includes a positioning rod and second support blades equidistantly fixed to the outer wall of the positioning rod, and the positioning rod is fixedly connected to the inner wall of the hollow cavity.

[0016] Optionally, the plurality of second supporting blades are all in a circular structure and are fixed to the inner wall of the hollow cavity, and the plurality of second supporting blades are all provided with through holes in a ring array.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] In the above scheme, a hollow cavity is opened in the replacement screw, the dissolving groove on the screw is connected to the hollow cavity, and the fast-dissolving support mechanism in the hollow cavity supports the outer shell of the replacement screw, so that the replacement screw maintains high strength. The body fluid dissolves the fast-dissolving support mechanism in the hollow cavity along the dissolving groove, so that the fast-dissolving support mechanism and the replacement screw are dissolved synchronously, thereby improving the dissolution rate of the replacement screw in the human body and avoiding the problem of the replacement screw dissolving too slowly and affecting bone growth.

[0019] A mounting groove for inserting the screw is opened on the side wall of the nut, and a protrusion is fixed on the inner wall of the mounting groove. After the replacement screw is fixed, the connecting plate and the fastening part are inserted into the mounting groove, and the anti-slip part on the connecting plate is protruded on the outer wall of the screw. At the same time, the protrusion is snapped into the positioning hole to keep the connecting plate fixed. The anti-slip part and the nut are in contact with the inner and outer walls of the bone respectively, so that the replacement screw is kept fixed in the orthopedics. The thickness of the anti-slip part and the connecting plate is much larger than the rapid dissolving support mechanism, and its dissolution speed is lower than the rapid dissolving support mechanism, which improves the stability of the replacement screw during the dissolution process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, further serve to explain the principles of the invention and to enable those skilled in the relevant art to make and use the invention.

[0021] Figure 1 This is a schematic diagram of the three-dimensional structure of a degradable orthopedic screw in situ replacement device;

[0022] Figure 2 This is a schematic diagram of the internal structure of the replacement screw;

[0023] Figure 3 It is a schematic diagram of the cross-sectional structure of the replacement screw;

[0024] Figure 4 This is a structural schematic diagram of the first embodiment of replacing the screw;

[0025] Figure 5 This is a schematic diagram of the structure of the second embodiment of replacing the screw;

[0026] Figure 6 It is a structural schematic diagram of the third embodiment of replacing the screw.

[0027] [Reference Signs]

[0028] 1. Replacement screw; 2. Threaded part; 3. Screw; 4. Nut; 5. Tightening groove; 6. Dissolving groove; 7. Degradable outer coating; 8. Stearic acid lipophilic layer; 9. Magnesium oxide layer; 10. Bump; 11. Anti-slip part; 12. Positioning hole; 13. Fastening part; 14. Connecting plate; 15. Installation groove; 16. Load-bearing rod; 17. Raised part; 18. First supporting blade; 19. Support frame; 20. Honeycomb hole; 21. Positioning rod; 22. Through hole; 23. Second supporting blade; 24. Hollow cavity.

[0029] As shown in the figure, in order to clearly implement the structure of the embodiment of the present invention, specific structures and devices are marked in the figure, but this is only for illustrative purposes and is not intended to limit the present invention to the specific structure, device and environment. According to specific needs, ordinary technicians in this field can adjust or modify these devices and environments. DETAILED DESCRIPTION

[0030] The following is a detailed description of a degradable orthopedic screw in-situ replacement device provided by the present invention in conjunction with the accompanying drawings and specific embodiments. At the same time, it is explained here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternatives to implement some known technologies; and the accompanying drawings are only for a more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0031] It should be noted that the references to "one embodiment", "embodiment", "exemplary embodiments", "some embodiments" and the like in the specification indicate that the embodiments described may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, when a specific feature, structure or characteristic is described in conjunction with an embodiment, it should be within the knowledge of a person skilled in the art to implement such feature, structure or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0032] In general, a term can be understood, at least in part, from its use in context. For example, depending, at least in part, on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense. Additionally, the term "based on" can be understood as not necessarily intended to convey an exclusive set of factors, but can instead, depending, at least in part, on the context, allow for the presence of other factors that are not necessarily explicitly described.

[0033] It will be understood that the meanings of “on,” “over,” and “above” in the present invention should be interpreted in the broadest manner, so that “on” not only means “directly on” something, but also includes the meaning of being “on” something with intervening features or layers therebetween, and “on” or “over” not only means “on” or “above” something, but also includes the meaning of being “on” or “above” something with no intervening features or layers therebetween.

[0034] Additionally, spatially relative terms such as "under," "beneath," "lower," "above," "upper," and the like may be used herein for descriptive convenience to describe the relationship of one element or feature to another element or features, as shown in the accompanying drawings. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. The device may be oriented in other ways, and the spatially relative descriptors used herein may be similarly interpreted accordingly.

[0035] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides an in-situ replacer for a degradable orthopedic screw, comprising a replacement screw 1 and a screw rod 3 and a nut 4 constituting the replacement screw 1. A hollow cavity 24 is provided at the center of the replacement screw 1, and a quick-dissolving support mechanism is embedded and fixed in the hollow cavity 24. A threaded portion 2 is provided at one end of the screw rod 3, and a dissolving groove 6 connected to the hollow cavity 24 is provided at the other end of the screw rod 3. A mounting groove 15 extending into the screw rod 3 is provided on the side wall of the nut 4, and an anti-slip component is embedded and fixed in the mounting groove 15.

[0036] The replacement screw 1 includes a magnesium alloy substrate and a degradable outer coating 7 fixed on the outside of the magnesium alloy substrate. A stearic acid lipophilic layer 8 is arranged between the magnesium alloy substrate and the degradable outer coating 7. A magnesium oxide layer 9 is arranged on the outside of the degradable outer coating 7. The stearic acid lipophilic layer 8 is located between the metal substrate and the degradable polymer film as an adhesive layer to enhance the adhesion between the two and optimize the mechanical properties of the overall structure. Stearic acid is widely used due to its good adhesion and biocompatibility. The magnesium oxide layer 9 generates a chemical conversion film such as a magnesium oxide layer 9 with a thickness of several nanometers on the surface of the metal substrate through chemical conversion treatment, which can significantly improve the corrosion resistance and mechanical properties of the material. This film can also serve as a base for subsequent coating layers to enhance the stability of the overall structure.

[0037] The components of the replacement screw 1 include: magnesium (Mg): 70-80% (basic component, providing main mechanical properties and degradation properties), zinc (Zn): 5-15% (improving strength and corrosion resistance, promoting tissue repair); rare earth elements (RE): 1-3% (optimizing mechanical properties and corrosion resistance); manganese (Mn) / zirconium (Zr): 0.5-1% each (refining grains, improving strength and toughness); calcium (Ca): 0.5-2% (increasing biological activity and promoting bone integration); silver (Ag) / silicon (Si) (optional): added in appropriate amounts according to specific needs to enhance antibacterial properties or improve processing properties.

[0038] like Figure 3 As shown, the side wall of the nut 4 is provided with a tightening groove 5, and both ends of the nut 4 are provided with a protrusion 10 fixed to the inner wall of the installation groove 15, the anti-slip part includes a connecting plate 14 and an anti-slip part 11 and a fastening part 13 fixed at both ends of the connecting plate 14, the anti-slip part 11 is obliquely arranged on the outer wall of the screw 3, the fastening part 13 is inserted into the nut 4, and the outer wall of the fastening part 13 is provided with a positioning hole 12 larger than one-half of the structure, the protrusion 10 is spherical and snap-fitted into the positioning hole 12, and the connection is fixed after the replacement screw 1 is fixed. The connecting plate 14 and the fastening part 13 are inserted into the installation groove 15, and the anti-slip part 11 on the connecting plate 14 is protruded from the outer wall of the screw 3. At the same time, the protrusion 10 is clamped in the positioning hole 12 to keep the connecting plate 14 fixed. The anti-slip part 11 and the nut 4 are in contact with the inner and outer walls of the bone respectively, so that the replacement screw 1 is kept fixed in the orthopedics. The thickness of the anti-slip part 11 and the connecting plate 14 is much larger than the rapid dissolution support mechanism, and its dissolution speed is lower than the rapid dissolution support mechanism, which improves the stability of the replacement screw 1 during the dissolution process.

[0039] like Figures 4 to 6As shown, the rapid dissolving support mechanism includes a load-bearing rod 16 and first support blades 18 fixed in a circular array on the outer wall of the load-bearing rod 16. Both ends of the load-bearing rod 16 are fixedly connected to the inner wall of the hollow cavity 24. The side walls of the plurality of first support blades 18 are fixed with protrusions 17, and the protrusions 17 are tightly connected to the inner wall of the nut 4. The dissolving grooves 6 in a circular array are connected to the plurality of first support blades 18, so that the plurality of first support blades 18 are dissolved synchronously.

[0040] The fast dissolving support mechanism includes a support frame 19 arranged in a ring array, both ends of the support frame 19 are fixedly connected to the inner wall of the hollow cavity 24, and a honeycomb hole 20 is opened at the center position of the support frame 19. The body fluid dissolves the outer wall of the support frame 19 along the dissolving groove 6, and dissolves on the inner wall of the honeycomb hole 20 after dissolving holes.

[0041] The fast-dissolving support mechanism includes a positioning rod 21 and second support blades 23 equidistantly fixed on the outer wall of the positioning rod 21. The positioning rod 21 is fixedly connected to the inner wall of the hollow cavity 24. The multiple second support blades 23 are all circular in structure and fixed to the inner wall of the hollow cavity 24. The multiple second support blades 23 are all provided with through holes 22 in a ring array. The multiple second support blades 23 are synchronously dissolved through the dissolving groove 6 and the through holes 22. The fast-dissolving support mechanism in the hollow cavity 24 supports the outer shell of the replacement screw 1, so that the replacement screw 1 maintains high strength. The body fluid dissolves the fast-dissolving support mechanism in the hollow cavity 24 along the dissolving groove 6, so that the fast-dissolving support mechanism and the replacement screw 1 are dissolved synchronously, thereby improving the dissolution speed of the replacement screw 1 in the human body.

[0042] The workflow of the technical solution of the present invention is as follows:

[0043] The dissolving groove 6 on the screw 3 is connected with the hollow cavity 24, and the quick dissolving support mechanism in the hollow cavity 24 supports the shell of the replacement screw 1, so that the replacement screw 1 maintains high strength, and the body fluid dissolves the quick dissolving support mechanism in the hollow cavity 24 along the dissolving groove 6, so that the quick dissolving support mechanism and the replacement screw 1 are dissolved synchronously, thereby improving the dissolution speed of the replacement screw 1 in the human body, and a protrusion 10 is fixed on the inner wall of the installation groove 15. After the replacement screw 1 is fixed, the connecting plate 14 and the fastening part 13 are inserted into the installation groove 15, and the anti-slip part 11 on the connecting plate 14 is protruded from the outer wall of the screw 3, and the protrusion 10 is clamped in the positioning hole 12 to keep the connecting plate 14 fixed, and the anti-slip part 11 and the nut 4 are in contact with the inner and outer walls of the bone respectively, so that the replacement screw 1 is fixed in the orthopedics, and the thickness of the anti-slip part 11 and the connecting plate 14 is much greater than the quick dissolving support mechanism, and its dissolution speed is lower than the quick dissolving support mechanism, thereby improving the stability of the replacement screw 1 during the dissolution process.

[0044] The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention. In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, in order to avoid unnecessary confusion about the essence of the present invention, well-known methods, processes, procedures, components and circuits are not described in detail.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A degradable orthopedic screw in situ replacer, characterized in that: It includes a replacement screw and a screw rod and a nut constituting the replacement screw. A hollow cavity is opened at the center position of the replacement screw, a quick dissolving support mechanism is embedded and fixed in the hollow cavity, a threaded portion is arranged at one end of the screw rod, and a dissolving groove connected to the hollow cavity is opened at the other end of the screw rod, a mounting groove extending into the screw rod is opened on the side wall of the nut, and an anti-slip component is embedded and fixed in the mounting groove.

2. The degradable orthopedic screw in situ replacer according to claim 1, characterized in that: The replacement screw includes a magnesium alloy substrate and a degradable outer coating fixed on the outside of the magnesium alloy substrate, a stearic acid lipophilic layer is arranged between the magnesium alloy substrate and the degradable outer coating, and a magnesium oxide layer is arranged on the outside of the degradable outer coating.

3. The degradable orthopedic screw in situ replacer according to claim 1, characterized in that: The side wall of the nut is provided with a tightening groove, and both ends of the nut are provided with protrusions fixed on the inner wall of the installation groove.

4. The degradable orthopedic screw in situ replacer according to claim 3, characterized in that: The anti-slipping member comprises a connecting plate and an anti-slipping portion and a fastening portion fixed at two ends of the connecting plate, and the anti-slipping portion is obliquely arranged on the outer wall of the screw rod.

5. The degradable orthopedic screw in situ replacer according to claim 4, characterized in that: The fastening part is inserted into the nut, and a positioning hole larger than one-half of the structure is opened on the outer wall of the fastening part. The protrusion is in a spherical structure and is inserted into the positioning hole.

6. The degradable orthopedic screw in situ replacer according to any one of claims 1 to 5, characterized in that: The fast dissolving support mechanism comprises a load-bearing rod and a first supporting blade fixed to the outer wall of the load-bearing rod in a ring array, and both ends of the load-bearing rod are fixedly connected to the inner wall of the hollow cavity.

7. The degradable orthopedic screw in situ replacer according to claim 6, characterized in that: The side walls of the plurality of first supporting blades are all fixed with a protrusion, and the protrusion is tightly connected to the inner wall of the nut.

8. The degradable orthopedic screw in situ replacer according to any one of claims 1 to 5, characterized in that: The fast dissolving support mechanism comprises a support frame arranged in a ring array, both ends of the support frame are fixedly connected to the inner wall of the hollow cavity, and a honeycomb hole is opened at the center of the support frame.

9. The degradable orthopedic screw in situ replacer according to any one of claims 1 to 5, characterized in that: The fast dissolving support mechanism comprises a positioning rod and second support blades fixed at equal distances on the outer wall of the positioning rod, and the positioning rod is fixedly connected to the inner wall of the hollow cavity.

10. The degradable orthopedic screw in situ replacer according to claim 9, characterized in that: The plurality of second supporting blades are all in a circular structure and are fixed to the inner wall of the hollow cavity, and the plurality of second supporting blades are all provided with through holes in a ring array.

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