Degradable orthopedic screw in-situ replacer

Abstract

The application provides a degradable orthopedic screw in-situ replacer, and belongs to the technical field of orthopedic screw replacement. The replacer comprises a replacement screw, a screw rod and a screw cap. A hollow cavity is arranged at the center of the replacement screw. A quick-dissolution support mechanism is fixed in the hollow cavity. The screw rod is provided with a threaded part at one end and a dissolution groove at the other end, which is communicated with the hollow cavity. An installation groove is arranged in the sidewall of the screw cap and extends into the screw rod. A anti-dropping piece is fixed in the installation groove. The replacement screw comprises a magnesium alloy base material and a degradable outer layer coating film fixed on the outer side of the magnesium alloy base material. A stearic acid lipophilic layer is arranged between the magnesium alloy base material and the degradable outer layer coating film. A magnesium oxide layer is arranged on the outer side of the degradable outer layer coating film. The application improves the dissolution speed of the replacement screw in the human body and avoids the problem that the slow dissolution speed of the replacement screw affects the bone growth.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of orthopedic screw replacement, in particular to a degradable orthopedic screw in-situ replacement device. BACKGROUND

[0002] In orthopedic surgery, screws are often used to fix fractured parts to promote healing and stability. However, the removal of screws can increase the risk of fracture at the screw hole site, especially in elderly patients. This risk is mainly due to the following factors: slow healing of the screw hole: after the screw is removed, the bone needs time to heal the screw hole. However, due to osteoporosis and weakened healing ability in the elderly, the healing of the screw hole may be slow, thereby increasing the risk of fracture; formation of hardening layer: long-term screw compression can cause the formation of a hardening layer around the screw channel, which hinders normal bone healing process, making the screw hole not heal for a long time. Osteoporosis: the elderly often have osteoporosis, which reduces the strength of the bone, further increasing the likelihood of fracture around the screw hole. Mechanical stress concentration: the screw hole site becomes a stress concentration point due to changes in material and structure, and is more likely to fracture under external force.

[0003] Chinese patent 201810531155.6 discloses a hook type orthopedic screw, which comprises a screw body, the screw body includes a ball head and a screw part, the screw part has a hollow mounting cavity, the hollow mounting cavity is provided with a hook type assembly capable of preventing the screw from moving, the hook type assembly includes a hook stop piece, a rotary pin and a distraction screw, the hook stop piece is a pair of pieces, fixed in the middle of the hollow mounting cavity, connected by the rotary pin between the two hook stop pieces, and the two hook stop pieces can rotate around the rotary pin, the distraction screw is correspondingly arranged above the hook stop piece, the top end of the distraction screw is movably connected with the ball head, and the bottom end abuts against the two hook stop pieces. The hook type orthopedic screw effectively combines the special hook stop piece, the distraction screw and the screw part, greatly improves the firmness when fixed with the bone surface, prevents the screw from loosening, moving, rotating, backing out and other problems during use, thereby ensuring the safety and reliability of the operation and reducing the pain of the patient.

[0004] The technical scheme can ensure the stability of the orthopedic screw fixed in the human body, but the screw needs to be designed as a solid to realize the positioning in the technical scheme, and the screw needs to be disassembled from the human body after use, which can easily cause secondary injury to the human body, and currently, in order to replace the traditional orthopedic screw, the screw is usually made of magnesium alloy, the magnesium alloy can be slowly absorbed in the human body, so that the screw does not need to be disassembled, however, since the recovery period of the human orthopedic surgery is generally between three months and half a year, and the absorption speed of the magnesium alloy screw is much slower than the recovery speed of the orthopedic surgery, the residual screw can hinder the growth of the bone, and in the process of dissolution and absorption, the volume of the screw becomes smaller, and the screw is prone to looseness and falling, therefore, the application provides a degradable orthopedic screw in-situ replacer to meet the needs. SUMMARY

[0005] The technical problem to be solved by the application is to provide a degradable orthopedic screw in-situ replacer to solve the problem that since the recovery period of the human orthopedic surgery is generally between three months and half a year, and the absorption speed of the magnesium alloy screw is much slower than the recovery speed of the orthopedic surgery, the residual screw can hinder the growth of the bone, and in the process of dissolution and absorption, the volume of the screw becomes smaller, and the screw is prone to looseness and falling.

[0006] To solve the above technical problems, the application provides the following technical scheme:

[0007] A degradable orthopedic screw in-situ replacer, comprising a replacement screw and a screw rod and a screw cap constituting the replacement screw, a hollow cavity is formed at the center position of the replacement screw, a quick-dissolution support mechanism is embedded and fixed in the hollow cavity, a threaded portion is arranged at one end of the screw rod, and a dissolution groove is formed at the other end of the screw rod and communicates with the hollow cavity, a mounting groove is formed in the side wall of the screw cap and extends into the screw rod, and an anti-falling piece is embedded and fixed in the mounting groove.

[0008] Optionally, the replacement screw comprises a magnesium alloy base material and a degradable outer layer coating film fixed outside the magnesium alloy base material, 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 outside the degradable outer layer coating film.

[0009] Optionally, a tightening groove is formed in the side wall of the screw cap, and protrusions are arranged at the inner walls of the mounting grooves at both ends of the screw cap.

[0010] Optionally, the anti-falling piece comprises a connecting plate and anti-falling portions and fastening portions fixed at both ends of the connecting plate, and the anti-falling portions are arranged obliquely on the outer wall of the screw rod.

[0011] Optionally, the fastening part is inserted into the screw cap, and the outer wall of the fastening part is provided with a positioning hole larger than half of the structure, and the protruding block is in spherical structure and is inserted into the positioning hole.

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

[0013] Optionally, the side wall of each of the plurality of first support blades is fixed with a protruding part, and the protruding part is tightly connected with the inner wall of the screw cap.

[0014] Optionally, the fast-dissolving support mechanism comprises a support frame in annular array, both ends of the support frame are fixedly connected with the inner wall of the hollow cavity, and a honeycomb hole is formed at the center position of the support frame.

[0015] Optionally, the fast-dissolving support mechanism comprises a positioning rod and a second support blade fixed at equal intervals on the outer wall of the positioning rod, and the positioning rod is fixedly connected with the inner wall of the hollow cavity.

[0016] Optionally, each of the plurality of second support blades is in circular structure and is fixed to the inner wall of the hollow cavity, and a through hole is formed in annular array on each of the plurality of second support blades.

[0017] Compared with the prior art, the present application has at least the following advantages:

[0018] In the above scheme, the hollow cavity is formed in the replacement screw, the dissolving groove on the screw rod is communicated with the hollow cavity, the fast-dissolving support mechanism in the hollow cavity supports the shell of the replacement screw, so that the replacement screw maintains high strength, and 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, the dissolution speed of the replacement screw in the human body is improved, and the problem that the slow dissolution speed of the replacement screw affects the growth of the bone is avoided.

[0019] The installation groove extending into the screw rod is formed in the side wall of the screw cap, the protruding block is fixed on the inner wall of the installation groove, the connecting plate and the fastening part of the replacement screw are inserted into the installation groove after being fixed, the anti-dropping part on the connecting plate is protrudingly arranged on the outer wall of the screw rod, the protruding block is clamped in the positioning hole to keep the connecting plate fixed, and the anti-dropping part and the screw cap are respectively in contact with the inner side and the outer wall of the bone, so that the replacement screw is kept fixed in the orthopedics department, the thickness of the anti-dropping part and the connecting plate is much larger than that of the fast-dissolving support mechanism, the dissolution speed of the anti-dropping part and the connecting plate is smaller than that of the fast-dissolving support mechanism, and the stability of the replacement screw in the dissolution process is improved. BRIEF DESCRIPTION OF DRAWINGS

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

[0021] Figure 1 Fig. 1 is a perspective view of a replaceable screw;

[0022] Figure 2 Fig. 2 is a sectional view of the replaceable screw;

[0023] Figure 3 Fig. 3 is a sectional view of the replaceable screw;

[0024] Figure 4 Fig. 4 is a perspective view of a first embodiment of the replaceable screw;

[0025] Figure 5 Fig. 5 is a perspective view of a second embodiment of the replaceable screw;

[0026] Figure 6 Fig. 6 is a perspective view of a third embodiment of the replaceable screw.

[0027] [Reference Signs]

[0028] 1, replaceable screw; 2, threaded portion; 3, screw rod; 4, screw cap; 5, tightening groove; 6, dissolving groove; 7, degradable outer coating; 8, stearic acid lipophilic layer; 9, magnesium oxide layer; 10, protrusion; 11, anti-disengagement portion; 12, positioning hole; 13, fastening portion; 14, connecting plate; 15, mounting groove; 16, load-bearing rod; 17, protruding portion; 18, first support blade; 19, support frame; 20, honeycomb hole; 21, positioning rod; 22, through hole; 23, second support blade; 24, hollow cavity.

[0029] As shown in the drawings, in order to clearly show the structure of the embodiments of the present application, specific structures and devices are marked in the drawings, but this is only for the need of illustration and is not intended to limit the present application to the specific structures, devices and environments. Those skilled in the art can adjust or modify these devices and environments according to specific needs. DETAILED DESCRIPTION

[0030] A replaceable screw in situ replacer according to the present application is described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and other alternative ways can also be used by those skilled in the art to implement them; and the drawings are only used to more specifically describe the embodiments and are not intended to specifically limit the present application.

[0031] It should be noted that references in the specification to "one embodiment," "an embodiment," "exemplary embodiments," "some embodiments," etc. indicate that the described embodiments may include specific features, structures, or characteristics, but not necessarily every embodiment will include such specific features, structures, or characteristics. Furthermore, when specific features, structures, or characteristics are described in conjunction with an embodiment, it is within the knowledge of persons skilled in the relevant art to implement such features, structures, or characteristics in conjunction with other embodiments (whether or not explicitly described).

[0032] In general, terms can be understood, at least in part, from their 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” means not only “directly on” something but also includes the meaning of being “on” something with intervening features or layers, and “on” or “above” means not only “on” or “above” something but also includes the meaning of being “on” or “above” something with no intervening features or layers.

[0034] Additionally, spatially relative terms such as "below," "beneath," "lower," "above," and "upper" may be used herein for descriptive convenience to describe the relationship of one element or feature to another element or features, as illustrated 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 should be similarly interpreted accordingly.

[0035] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a degradable orthopedic screw in situ replacer, 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 fast-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 comprises a magnesium alloy base material and a degradable outer layer coating 7 fixed outside the magnesium alloy base material, and a stearic acid lipophilic layer 8 is arranged between the magnesium alloy base material and the degradable outer layer coating 7, and a magnesium oxide layer 9 is arranged outside the degradable outer layer coating 7, the stearic acid lipophilic layer 8 is arranged as an adhesive layer between the metal base and the degradable polymer film, so as to enhance the adhesion between the two and optimize the mechanical properties of the overall structure, and the stearic acid is widely used due to its good adhesion and biocompatibility; the magnesium oxide layer 9 generates a chemical conversion film such as the magnesium oxide layer 9 on the surface of the metal base with a thickness of several nanometers, which can significantly improve the corrosion resistance and mechanical properties of the material. This layer of film can also serve as a substrate for subsequent coating layers, enhancing 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 performance), 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): each 0.5-1% (refining grains, improving strength and toughness); calcium (Ca): 0.5-2% (increasing biological activity, 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] As shown in Figure 3 The side wall of the nut 4 is provided with a tightening groove 5, and the two ends of the nut 4 are provided with protrusions 10 fixed in the inner wall of the mounting groove 15, the anti-disengagement part includes a connecting plate 14 and anti-disengagement parts 11 and fastening parts 13 fixed at both ends of the connecting plate 14, the anti-disengagement parts 11 are inclinedly arranged on the outer wall of the screw rod 3, the fastening parts 13 are snugly inserted into the nut 4, and the outer wall of the fastening parts 13 is provided with a positioning hole 12 larger than one-half of the structure, the protrusions 10 are in spherical structure and are snugly clamped in the positioning hole 12, the connecting plate 14 and the fastening parts 13 are inserted into the mounting groove 15 after the replacement screw 1 is fixed, and the anti-disengagement parts 11 on the connecting plate 14 are protrudingly arranged on the outer wall of the screw rod 3, while the protrusions 10 are clamped in the positioning hole 12 to keep the connecting plate 14 fixed, the anti-disengagement parts 11 and the nut 4 are in contact with the inner side and the outer wall of the bone respectively, so that the replacement screw 1 is kept fixed in the orthopedics department, and the thickness of the anti-disengagement parts 11 and the connecting plate 14 is much larger than that of the fast-dissolving support mechanism, and the dissolution speed is smaller than that of the fast-dissolving support mechanism, thereby improving the stability of the replacement screw 1 during the dissolution process.

[0039] As shown in Figures 4 to 6As shown, the fast-dissolving support mechanism includes a load-bearing rod 16 and a first support blade 18 fixed in an annular array on the outer wall of the load-bearing rod 16, both ends of the load-bearing rod 16 are fixedly connected with the inner wall of the hollow cavity 24, the side wall of the plurality of first support blades 18 is fixed with a protruding portion 17, the protruding portion 17 is tightly connected with the inner wall of the screw cap 4, the annular array of the dissolving groove 6 is communicated with 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 an annular array, both ends of the support frame 19 are fixedly connected with the inner wall of the hollow cavity 24, and a honeycomb hole 20 is formed 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 the inner wall of the honeycomb hole 20 after the hole is dissolved.

[0041] The fast-dissolving support mechanism includes a positioning rod 21 and a second support blade 23 fixed at equal intervals on the outer wall of the positioning rod 21, the positioning rod 21 is fixedly connected with the inner wall of the hollow cavity 24, the plurality of second support blades 23 are fixed with the inner wall of the hollow cavity 24 in a circular structure, and a through hole 22 is formed in an annular array on the plurality of second support blades 23, the plurality of second support blades 23 are dissolved synchronously through the dissolving groove 6 and the through hole 22, the fast-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, 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, and the dissolution speed of the replacement screw 1 in the human body is improved.

[0042] The working process of the technical scheme of the present application is as follows:

[0043] The dissolving groove 6 on the screw rod 3 is communicated with the hollow cavity 24, the fast-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, 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, and the dissolution speed of the replacement screw 1 in the human body is improved, the protruding block 10 is fixed on the inner wall of the installation groove 15, the replacement screw 1 is inserted into the installation groove 15 after being fixed, and the anti-dropping portion 11 on the connecting plate 14 is protrudingly arranged on the outer wall of the screw rod 3, at the same time, the protruding block 10 is clamped in the positioning hole 12 to make the connecting plate 14 remain fixed, the anti-dropping portion 11 and the screw cap 4 are respectively contacted with the inner side and the outer wall of the bone, so that the replacement screw 1 remains fixed in the orthopedics department, the thickness of the anti-dropping portion 11 and the connecting plate 14 is much greater than that of the fast-dissolving support mechanism, the dissolution speed thereof is less than that of the fast-dissolving support mechanism, and the stability of the replacement screw 1 in the dissolution process is improved.

[0044] The present application encompasses any alternatives, modifications, equivalent methods and solutions made to the essence and scope of the present application. In order to make the public have a thorough understanding of the present application, specific details are described in the following preferred embodiments of the present application, and the present application can also be fully understood without the description of these details to those skilled in the art. In addition, in order to avoid unnecessary confusion to the essence of the present application, well-known methods, processes, procedures, elements and circuits, etc. are not described in detail.

[0045] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can also be made, which should be considered as the protection scope of the present application.

Claims

1. A degradable orthopedic screw in-situ replacer, characterized in that, The application relates to a replacement screw which comprises a screw rod and a screw cap, a hollow cavity is formed in the center of the replacement screw, a quick-dissolving supporting mechanism is embedded in the hollow cavity, a threaded part is arranged at one end of the screw rod, a dissolving groove is formed in the other end of the screw rod and communicates with the hollow cavity, an installation groove is formed in the side wall of the screw cap, and an anti-falling piece is embedded in the installation groove. The anti-falling piece comprises a connecting plate and anti-falling parts fixed at the two ends of the connecting plate, and the anti-falling parts are arranged obliquely on the outer wall of the screw rod. The anti-falling parts and the screw cap are in contact with the inner side and the outer wall of the bone respectively, so that the replacement screw is fixed in the bone, the thickness of the anti-falling parts and the connecting plate is greater than that of the quick-dissolving supporting mechanism, and the dissolving speed of the anti-falling parts and the connecting plate is smaller than that of the quick-dissolving supporting mechanism.

2. The degradable orthopedic screw in-situ replacer of claim 1, wherein, The replacement screw comprises a magnesium alloy base material and a degradable outer layer coating film fixed on the outer side of the magnesium alloy base material, 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 layer coating film.

3. The degradable orthopedic screw in-situ replacer of claim 1, wherein, The side wall of the screw cap is provided with a screwing groove, and the two ends of the screw cap are provided with protrusions fixed on the inner wall of the installation groove.

4. The degradable orthopedic screw in-situ replacer of claim 3, wherein, The anti-falling piece further comprises a fastening part which is inserted into the screw cap in a matching way, the outer wall of the fastening part is provided with a positioning hole which is greater than one half of the structure, and the protrusions are in spherical structure and are matched and clamped in the positioning hole.

5. The degradable orthopedic screw in-situ replacer according to any one of claims 1-4, characterized in that, The quick-dissolving supporting mechanism comprises a bearing rod and first supporting blades which are fixed on the outer wall of the bearing rod in a ring array, and the two ends of the bearing rod are fixedly connected with the inner wall of the hollow cavity.

6. The degradable orthopedic screw in-situ replacer of claim 5, wherein, The side wall of each of the first supporting blades is fixed with a protruding part which is tightly connected with the inner wall of the screw cap.

7. The degradable orthopedic screw in-situ replacer according to any one of claims 1-4, wherein, The quick-dissolving supporting mechanism comprises supporting frames which are arranged in a ring array, the two ends of the supporting frames are fixedly connected with the inner wall of the hollow cavity, and a honeycomb hole is formed in the center of the supporting frames.

8. The degradable orthopedic screw in-situ replacer according to any one of claims 1-4, wherein, The quick-dissolving supporting mechanism comprises a positioning rod and second supporting blades which are fixed on the outer wall of the positioning rod at equal intervals, and the positioning rod is fixedly connected with the inner wall of the hollow cavity.

9. The degradable orthopedic screw in-situ replacer of claim 8, wherein, Each of the second supporting blades is fixed with the inner wall of the hollow cavity in a circular structure, and a through hole is formed in the second supporting blades in a ring array.

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