Metal locking screw and screw plate fixing system

Abstract

The utility model discloses a metal locking screw and a screw plate fixing system, and belongs to the technical field of orthopedic implants, the metal locking screw sequentially comprises a screw head, a screw rod and a screw cap from front to back, the screw rod is provided with external threads, the outer surface of the screw cap is provided with helical teeth extending in the front-back direction, and the screw head is provided with external threads. The helical teeth are formed by a series of teeth arranged along a helical line; the nail cap is provided with a containing hole used for containing medical polylactic acid, and the outer surface of the nail cap is provided with a melting flow hole which is communicated with the containing hole and allows molten medical polylactic acid to flow out. The metal locking screw and the screw plate fixing system are suitable for bone plates made of high polymer materials, the screw can be prevented from being disengaged and cut in the body, and firmness is good.

Description

Technical Field

[0001] The utility model relates to the technical field of orthopedic implants, in particular to a metal locking screw and a nail plate fixing system. Background Art

[0002] Existing bone fixation plates (hereinafter referred to as "bone plates") are mostly made of metal materials, generally stainless steel or titanium alloy materials. For example, utility model patent CN204618382U discloses a clavicle hook bone plate, utility model patent CN216985116U discloses a bone plate, and utility model patent CN214104581U discloses a distal tibia bone plate.

[0003] Research has found that the density of the above metal bone plates is much greater than that of bones, which blocks the fracture line in imaging and cannot clearly reflect the healing state after fracture. Therefore, special polymer bone plates have gradually become a new choice. Polymer bone plates are also fixed with screws, but the screws used with them are prone to dislocation and cutting in the body, and their firmness is poor. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a metal locking screw and nail plate fixing system which is suitable for a polymer material bone plate and can prevent the screw from coming out and being cut in the body and has good firmness.

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0006] On the one hand, a metal locking screw is provided, which comprises a nail head, a nail rod and a nail cap from front to back, the nail rod is provided with an external thread, and the outer surface of the nail cap is provided with spiral teeth extending in the front-to-back direction, and the spiral teeth are formed by a series of teeth arranged along a spiral line;

[0007] The nail cap is provided with a receiving hole for placing the medical polylactic acid, and the outer surface of the nail cap is provided with a melting flow hole connected with the receiving hole for the melted medical polylactic acid to flow out.

[0008] Furthermore, the spiral teeth are tapered and gradually narrow from back to front, and the angle of the tapered teeth is 2°-6°;

[0009] And / or, the pitch of the helical teeth is 1.5 mm-0.2 mm.

[0010] Furthermore, each tooth of the helical teeth is an anti-retraction tooth inclined toward the rotation and withdrawal direction of the metal locking screw.

[0011] Furthermore, the angle between the two oblique sides of the anti-backward tooth is 30°-60°, and one of the oblique sides passes through the radius.

[0012] Furthermore, the included angle between the oblique edges of two adjacent anti-recession teeth crossing the radius is 5°-20°.

[0013] Furthermore, the number of the melt flow holes is at least two and they are evenly arranged along the circumference of the nail cap, and the ratio of the distance between adjacent melt flow holes to the diameter of the nail cap is 1 / 2-1 / 8;

[0014] And / or, the diameter of the melt flow hole is 0.2mm-1mm.

[0015] Furthermore, the nail head is provided with an arc-shaped self-tapping groove;

[0016] And / or, the front end of the nail head is provided with a chamfer, and the radius of the chamfer is 1mm-3mm;

[0017] And / or, the nail head is conical, and the angle of the cone is 30°-50°.

[0018] Furthermore, the pitch of the external thread is greater than the pitch of the helical teeth;

[0019] And / or, the maximum diameter of the external thread is 6mm-2mm;

[0020] And / or, the minimum diameter of the external thread is 5.5 mm-1.5 mm;

[0021] And / or, the pitch of the external thread is 2mm-0.4mm;

[0022] And / or, the diameter of the nail cap is 8mm-2.2mm.

[0023] On the other hand, a nail plate fixing system is provided, comprising a bone plate and the above-mentioned metal locking screw, wherein the material of the bone plate is a polymer material.

[0024] Furthermore, the bone plate is provided with a nail hole for accommodating the metal locking screw, wherein:

[0025] The angle between the axis of the metal locking screw and the axis of the nail hole is 0°-20°;

[0026] And / or, the nail hole is a countersunk hole.

[0027] The utility model has the following beneficial effects:

[0028] The metal locking screw and nail plate fixing system of the utility model is innovatively designed with a new screw structure according to the material characteristics of the polymer material bone plate. Specifically, the nail rod of the metal locking screw is provided with an external thread, and the outer surface of the nail cap is provided with spiral teeth extending in the front-to-back direction. The spiral teeth are formed by a series of teeth arranged along the spiral line. The arrangement of the spiral teeth enables the nail cap to form a nail tail self-tapping structure, which not only facilitates the nail cap to tap into the polymer material bone plate, but also can form a one-time multi-axis angle locking with the polymer material bone plate, which can prevent the screw from coming out and Cutting, good firmness; the nail cap is provided with a receiving hole for placing medical polylactic acid, and the outer surface of the nail cap is provided with a melt flow hole connected to the receiving hole for the melted medical polylactic acid to flow out. Compared with the prior art, due to the setting of the receiving hole and the melt flow hole, the melted medical polylactic acid can flow out from the melt flow hole, and the medical polylactic acid can be further reinforced through the melt flow hole after the screw and the bone plate are locked. It can not only ensure the connection strength between the screw and the bone plate, but also prevent the screw from continuously generating carbon fiber debris in the body after cutting the bone plate, thereby reducing the inflammatory response. The metal locking screw and nail plate fixing system of the utility model is suitable for polymer bone plates, can prevent the screw from falling out and cutting in the body, and has good firmness. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a three-dimensional structural schematic diagram of the metal locking screw of the utility model;

[0030] Figure 2 It is a side view structural schematic diagram of the metal locking screw of the utility model;

[0031] Figure 3 This is a schematic diagram of the use status of the metal locking screw of the utility model;

[0032] Figure 4 for Figure 3 A schematic cross-sectional structure diagram of ;

[0033] Figure 5 It is an enlarged structural schematic diagram of the nail head of the metal locking screw of the utility model;

[0034] Figure 6 It is an enlarged structural schematic diagram of the nail rod of the metal locking screw of the utility model;

[0035] Figure 7 It is an enlarged structural schematic diagram of the nail cap of the metal locking screw of the utility model;

[0036] Figure 8 It is a front structural schematic diagram of the metal locking screw of the utility model. DETAILED DESCRIPTION

[0037] In order to make the technical problems to be solved, technical solutions and advantages of the present invention more clear, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0038] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0039] On the one hand, the utility model provides a metal locking screw 1, such as Figure 1-8 As shown, from front to back, it includes a nail head 11, a nail rod 12 and a nail cap 13, the nail rod 12 is provided with an external thread 121, and the outer surface of the nail cap 13 is provided with spiral teeth 131 extending in the front-to-back direction, and the spiral teeth 131 are formed by a series of teeth arranged along a spiral line;

[0040] The nail cap 13 is provided with a receiving hole 132 for placing the medical polylactic acid 2 , and the outer surface of the nail cap 13 is provided with a melt flow hole 133 which is connected with the receiving hole 132 and allows the melted medical polylactic acid 2 to flow out.

[0041] During the operation, the metal locking screw 1 is held and implanted at the required position and locked with the bone plate 3. After the implantation is completed, the medical polylactic acid 2 is placed in the receiving hole 132 of the metal locking screw 1. The medical polylactic acid 2 solid is liquefied by using a high-temperature ultrasonic head 4. The melted medical polylactic acid 2 flows out from the melting hole 133. After the medical polylactic acid 2 is cooled and solidified, the metal locking screw 1 is reinforced with the bone plate 3 at the melting hole 133 for the second time (see Figure 3-4 ).

[0042] The metal locking screw of the utility model can be specifically a metal multi-axis self-tapping locking screw, wherein the nail rod is provided with an external thread, and the outer surface of the nail cap is provided with spiral teeth extending in the front-to-back direction, and the spiral teeth are formed by a series of teeth arranged along the spiral line. The setting of the spiral teeth enables the nail cap to form a nail tail self-tapping structure, which not only facilitates the nail cap to enter the polymer material bone plate, but also can form a one-time multi-axis angle locking with the polymer material bone plate, which can prevent the screw from coming out and cutting in the body, and has good firmness; the nail cap is provided with a receiving hole for placing medical polylactic acid, and the outer surface of the nail cap is provided with a melting hole connected with the receiving hole for the melted medical polylactic acid to flow out. Compared with the prior art, due to the setting of the receiving hole and the melting hole, the melted medical polylactic acid can flow out from the melting hole, and the medical polylactic acid can be further reinforced through the melting hole after the screw and the bone plate are locked, which can not only ensure the connection strength between the screw and the bone plate, but also prevent the screw from continuously generating carbon fiber debris in the body after cutting the bone plate, thereby reducing the inflammatory response. The metal locking screw of the utility model is suitable for a polymer bone plate and can be locked in cooperation with a (special) polymer bone plate, thereby preventing the screw from coming out and being cut in the body and having good firmness.

[0043] like Figure 7 As shown, the spiral teeth 131 may be tapered from back to front, and the angle γ of the tapered shape may be 2°-6°, such as 3°, 4°, 5°, etc., so as to facilitate the nail cap 13 to better penetrate the polymer bone plate 3. The pitch P2 of the spiral teeth 131 may be 1.5 mm-0.2 mm, such as 0.6 mm, 0.8 mm, 1.2 mm, etc.

[0044] like Figure 8 As shown, each tooth of the spiral tooth 131 can be an anti-retraction tooth inclined in the direction of rotation and withdrawal of the metal locking screw 1, so that after the metal locking screw 1 is locked with the polymer bone plate 3, the metal locking screw 1 can be better prevented from being dislodged and cut in the body, and the firmness is better. Preferably, the angle δ between the two hypotenuses of the anti-retraction tooth is 30°-60°, and one of the hypotenuses passes through the radius. The angle ε between the hypotenuses of two adjacent anti-retraction teeth that pass through the radius can be 5°-20°, for example 8°, 10°, 15°, etc.

[0045] like Figure 7 As shown, the number of melt holes 133 can be at least two and they are evenly arranged along the circumference of the nail cap 13, and the ratio of the distance l1 between adjacent melt holes 133 to the diameter D1 of the nail cap 13 is 1 / 2-1 / 8, so that after the medical polylactic acid 2 is cooled and solidified, it can better prevent the metal locking screw 1 from being dislodged and cut in the body, and the firmness is better. The diameter D2 of the melt hole 133 can be 0.2mm-1mm, such as 0.5mm, 0.8mm, 0.9mm, etc.

[0046] like Figure 1-2As shown, the nail head 11 may be provided with an arc-shaped self-tapping groove 111 (i.e., a nail head arc groove), so that the self-tapping groove 111 and the external thread 121 on the nail rod 12 form a structure with self-cutting ability, which can play a tapping role when the metal locking screw 1 is rotated and implanted, and can ensure that the metal locking screw 1 has a complete nail path when it is tapped into the polymer bone plate 3, and the metal locking screw 1 is tightly combined with the polymer bone plate 3, and is not prone to loosening and cutting problems. The number of self-tapping grooves 111 can be 2-3 and evenly distributed.

[0047] like Figure 5 As shown, the front end of the nail head 11 may be chamfered, and the radius R1 of the chamfer is 1mm-3mm, such as 1.5mm, 1.8mm, 2.5mm, etc. The nail head 11 may be conical, and the angle β of the cone is 30°-50°, such as 35°, 40°, 45°, etc., to facilitate the implantation of the metal locking screw 1.

[0048] like Figure 1-2 As shown, the pitch P1 of the external thread 121 can be greater than the pitch P2 of the spiral teeth 131, that is, there is a pitch difference between the pitch P1 of the external thread 121 and the pitch P2 of the spiral teeth 131, which can produce a resetting and traction effect on the bone. After the metal locking screw 1 and the polymer bone plate 3 are locked, the polymer bone plate 3 and the bone block can be tightly pressed together, and the firmness is good.

[0049] like Figure 6 As shown, the maximum diameter D of the external thread 121 can be 6 mm-2 mm, such as 3 mm, 4 mm, 5 mm, etc. The minimum diameter d of the external thread 121 can be 5.5 mm-1.5 mm, such as 3.5 mm, 4.5 mm, 5 mm, etc. The pitch P1 of the external thread 121 can be 2 mm-0.4 mm, such as 0.8 mm, 1.2 mm, 1.8 mm, etc. Figure 7 As shown, the diameter D1 of the nail cap 13 can be 8 mm-2.2 mm, for example, 3 mm, 5 mm, 7 mm, etc.

[0050] On the other hand, the utility model provides a nail plate fixing system, including a bone plate 3 and the above-mentioned metal locking screw 1, the material of the bone plate 3 is a polymer material (such as carbon fiber, polyetheretherketone, etc.). The structure of the metal locking screw 1 is the same as above and will not be repeated here.

[0051] The nail plate fixing system of the utility model has an external thread on the nail rod of the metal locking screw, and the outer surface of the nail cap is provided with spiral teeth extending in the front-to-back direction, and the spiral teeth are formed by a series of teeth arranged along the spiral line. The setting of the spiral teeth enables the nail cap to form a nail tail self-tapping structure, which not only facilitates the nail cap to enter the polymer material bone plate, but also can form a one-time multi-axis angle locking with the polymer material bone plate, which can prevent the screw from coming out and cutting in the body, and has good firmness; the nail cap is provided with a receiving hole for placing medical polylactic acid, and the outer surface of the nail cap is provided with a melting hole connected with the receiving hole for the melted medical polylactic acid to flow out. Compared with the prior art, due to the setting of the receiving hole and the melting hole, the melted medical polylactic acid can flow out from the melting hole, and the medical polylactic acid can be further reinforced through the melting hole after the screw and the bone plate are locked, which can not only ensure the connection strength between the screw and the bone plate, but also prevent the screw from continuously generating carbon fiber debris in the body after cutting the bone plate, thereby reducing inflammatory response. The screw plate fixing system of the utility model is suitable for a bone plate made of a polymer material, can prevent the screw from coming out and being cut in the body, and has good firmness.

[0052] like Figure 3 As shown, the bone plate 3 may be provided with a nail hole 31 for accommodating the metal locking screw 1, and the angle α between the axis M of the metal locking screw 1 and the axis N of the nail hole 31 may be 0°-20°, that is, the axis M of the metal locking screw 1 may swing within the range of 0°-20° relative to the axis N of the nail hole 31, so as to facilitate the universal implantation of the metal locking screw 1 and the self-tapping locking of the metal locking screw 1 with the polymer bone plate 3. The nail hole 31 may be a countersunk hole to prevent the metal locking screw 1 from protruding out of the polymer bone plate 3 and avoid unnecessary interference with the soft tissue.

[0053] The above is 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 principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A metal locking screw, comprising a nail head, a nail rod and a nail cap from front to back, characterized in that: The nail rod is provided with an external thread, and the outer surface of the nail cap is provided with spiral teeth extending in the front-to-back direction, and the spiral teeth are formed by a series of teeth arranged along a spiral line; The nail cap is provided with a receiving hole for placing the medical polylactic acid, and the outer surface of the nail cap is provided with a melting flow hole connected with the receiving hole for the melted medical polylactic acid to flow out.

2. The metal locking screw according to claim 1, characterized in that: The spiral teeth are tapered and gradually narrow from back to front, and the angle of the tapered teeth is 2°-6°; And / or, the pitch of the helical teeth is 1.5 mm-0.2 mm.

3. The metal locking screw according to claim 1, characterized in that: Each tooth of the helical teeth is an anti-backout tooth inclined toward the rotation backout direction of the metal locking screw.

4. The metal locking screw according to claim 3, characterized in that: The angle between the two bevels of the anti-backward tooth is 30°-60°, and one of the bevels passes through the radius.

5. The metal locking screw according to claim 4, characterized in that: The included angle between the oblique edges of two adjacent anti-recession teeth crossing the radius is 5°-20°.

6. The metal locking screw according to claim 1, characterized in that: The number of the melt flow holes is at least two and they are evenly arranged along the circumference of the nail cap, and the ratio of the distance between adjacent melt flow holes to the diameter of the nail cap is 1 / 2-1 / 8; And / or, the diameter of the melt flow hole is 0.2mm-1mm.

7. The metal locking screw according to claim 1, characterized in that: The nail head is provided with an arc-shaped self-tapping groove; And / or, the front end of the nail head is provided with a chamfer, and the radius of the chamfer is 1mm-3mm; And / or, the nail head is conical, and the angle of the cone is 30°-50°.

8. The metal locking screw according to claim 1, characterized in that: The pitch of the external thread is greater than the pitch of the helical teeth; And / or, the maximum diameter of the external thread is 6mm-2mm; And / or, the minimum diameter of the external thread is 5.5 mm-1.5 mm; And / or, the pitch of the external thread is 2mm-0.4mm; And / or, the diameter of the nail cap is 8mm-2.2mm.

9. A nail plate fixing system, characterized in that: It comprises a bone plate and the metal locking screw according to any one of claims 1 to 8, wherein the material of the bone plate is a polymer material.

10. The nail plate fixing system according to claim 9, characterized in that: The bone plate is provided with a nail hole for accommodating the metal locking screw, wherein: The angle between the axis of the metal locking screw and the axis of the nail hole is 0°-20°; And / or, the nail hole is a countersunk hole.

Images