Locking screw and bone lamella fixing system

Abstract

The utility model discloses a locking screw and a bone lamella fixing system and belongs to the technical field of orthopedic implants, the locking screw is made of metal materials and sequentially comprises a screw head, a screw rod and a screw cap from front to back, the screw rod comprises a small-diameter section serving as a main body and a large-diameter section located behind the small-diameter section, the small-diameter section is provided with external threads, and the large-diameter section is provided with external threads. The outer surface of the large-diameter section is provided with spiral teeth extending in the front-back direction, and the spiral teeth are formed by a series of teeth arranged along a spiral line. The locking screw and the bone 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 locking screw and bone 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 locking screw and bone 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 locking screw is provided, which is made of metal and includes, from front to back, a nail head, a nail rod and a nail cap, the nail rod includes a small diameter section as a main body and a large diameter section located behind the small diameter section, the small diameter section is provided with an external thread, and the outer surface of the large diameter section 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] Furthermore, the spiral teeth are tapered and gradually narrow from back to front, and the angle of the tapered teeth is 2°-6°;

[0008] And / or, the pitch of the helical teeth is 1.5 mm-0.2 mm.

[0009] Furthermore, each tooth of the helical teeth is an anti-retraction tooth inclined toward the rotation withdrawal direction of the locking screw.

[0010] 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.

[0011] Furthermore, the included angle between the oblique edges of two adjacent anti-recession teeth crossing the radius is 5°-20°.

[0012] Furthermore, the nail head is provided with an arc-shaped self-tapping groove;

[0013] And / or, the front end of the nail head is provided with a chamfer, and the radius of the chamfer is 1mm-3mm;

[0014] And / or, the nail head is conical, and the angle of the cone is 30°-50°.

[0015] Furthermore, the pitch of the external thread is greater than the pitch of the helical teeth;

[0016] And / or, the maximum diameter of the external thread is 6mm-2mm;

[0017] And / or, the minimum diameter of the external thread is 5.5 mm-1.5 mm;

[0018] And / or, the pitch of the external thread is 2mm-0.4mm.

[0019] Furthermore, the nail cap is stepped, wherein:

[0020] The maximum diameter of the nail cap is 10mm-3mm;

[0021] And / or, the minimum diameter of the nail cap is 8mm-2.2mm.

[0022] On the other hand, a bone plate fixing system is provided, comprising a bone plate and the above-mentioned locking screw, wherein the bone plate is made of a polymer material.

[0023] Furthermore, the bone plate is provided with a nail hole for accommodating the locking screw, wherein:

[0024] The angle between the axis of the locking screw and the axis of the nail hole is 0°-20°;

[0025] And / or, the nail hole is a countersunk hole.

[0026] The utility model has the following beneficial effects:

[0027] The locking screw and bone plate fixing system of the utility model innovatively designs a new screw structure according to the material characteristics of the polymer bone plate. Specifically, the nail rod of the locking screw includes a small diameter section as a main body and a large diameter section located behind the small diameter section. The small diameter section is provided with an external thread, and the outer surface of the large diameter section 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 large diameter section of the nail rod to form a nail tail self-tapping structure, which not only facilitates the large diameter section to penetrate into the polymer bone plate, but also can form a one-time multi-axis angle locking with the polymer bone plate. It is suitable for polymer bone plates, can prevent the screws from falling out and cutting in the body, and has good firmness. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a three-dimensional structural schematic diagram of the locking screw of the utility model;

[0029] Figure 2 It is a side view structural schematic diagram of the locking screw of the utility model;

[0030] Figure 3 This is a schematic diagram of the locking screw of the utility model in use;

[0031] Figure 4 It is an enlarged structural schematic diagram of the nail head of the locking screw of the utility model;

[0032] Figure 5 It is an enlarged structural schematic diagram of the nail rod of the locking screw of the utility model;

[0033] Figure 6 It is an enlarged structural schematic diagram of the nail cap of the locking screw of the utility model;

[0034] Figure 7 It is a front structural schematic diagram of the locking screw of the utility model. DETAILED DESCRIPTION

[0035] 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.

[0036] 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.

[0037] On the one hand, the utility model provides a locking screw 1, such as Figure 1-7 As shown, the locking screw 1 is made of metal, and includes a nail head 11, a nail rod 12 and a nail cap 13 from front to back. The nail rod 12 includes a small diameter section 122 as a main body and a large diameter section 123 located behind the small diameter section 122 (for matching with the nail hole 21 on the bone plate 2). The small diameter section 122 is provided with an external thread 121, and the outer surface of the large diameter section 123 is provided with spiral teeth 124 extending in the front-to-back direction, and the spiral teeth 124 are formed by a series of teeth arranged along a spiral line.

[0038] During use, the locking screw 1 is held and the screw head 11 of the locking screw 1 is screwed into the bone plate 2 along the pre-planned screw path and driven into the bone. The spiral teeth 124 gradually approach the bone plate 2 and lock with the bone plate 2, and the implantation is completed (see Figure 3 ).

[0039] The locking screw of the utility model can specifically be a metal multi-axis self-tapping locking screw, whose nail rod includes a small diameter section as a main body and a large diameter section located behind the small diameter section, the small diameter section is provided with an external thread, and the outer surface of the large diameter section 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 arrangement of the spiral teeth enables the large diameter section of the nail rod to form a nail tail self-tapping structure, which not only facilitates the large diameter section to penetrate into the polymer material bone plate, but also can form a one-time multi-axis angle locking with the polymer material bone plate. It is suitable for (special) polymer material bone plates, can prevent the screws from falling out and cutting in the body, and has good firmness.

[0040] like Figure 6 As shown, the spiral teeth 124 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 2. The pitch P2 of the spiral teeth 124 may be 1.5 mm-0.2 mm, such as 0.6 mm, 0.8 mm, 1.2 mm, etc.

[0041] like Figure 7 As shown, each tooth of the spiral tooth 124 can be an anti-retraction tooth inclined in the direction of rotation and withdrawal of the locking screw 1, so that after the locking screw 1 and the polymer bone plate 2 are locked, the 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°, such as 8°, 10°, 15°, etc.

[0042] like Figure 1-2 As 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 locking screw 1 is rotated and implanted, and can ensure that the locking screw 1 has a complete nail path when it is tapped into the polymer bone plate 2, and the locking screw 1 is tightly combined with the polymer bone plate 2, and is not prone to loosening and cutting problems. The number of self-tapping grooves 111 can be 2-3 and evenly distributed.

[0043] like Figure 4As 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 locking screw 1.

[0044] 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 124, that is, there is a pitch difference between the pitch P1 of the external thread 121 and the pitch P2 of the spiral teeth 124, which can produce a resetting and traction effect on the bone. After the locking screw 1 and the polymer bone plate 2 are locked, the polymer bone plate 2 and the bone block can be tightly pressed together, and the firmness is good.

[0045] like Figure 5 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.

[0046] like Figure 6 As shown, the nail cap 13 may be stepped, and the maximum diameter D1 of the nail cap 13 may be 10 mm-3 mm, such as 5 mm, 6 mm, 8 mm, etc. The minimum diameter D2 of the nail cap 13 may be 8 mm-2.2 mm, such as 3 mm, 5 mm, 7 mm, etc.

[0047] On the other hand, the utility model provides a bone plate fixing system, comprising a bone plate 2 and the above-mentioned locking screw 1, wherein the bone plate 2 is made of a polymer material (such as carbon fiber, polyetheretherketone, etc.). The structure of the locking screw 1 is the same as above and will not be repeated here.

[0048] The bone plate fixing system of the utility model has a nail rod of a locking screw comprising a small diameter section as a main body and a large diameter section located behind the small diameter section, the small diameter section is provided with an external thread, the outer surface of the large diameter section is provided with spiral teeth extending in the front-to-back direction, the spiral teeth being formed by a series of teeth arranged along a spiral line, the arrangement of the spiral teeth enables the large diameter section of the nail rod to form a nail tail self-tapping structure, which not only facilitates the large diameter section to penetrate into the polymer material bone plate, but also can form a one-time multi-axis angle locking with the polymer material bone plate, is suitable for (special) polymer material bone plates, can prevent the screws from falling out and being cut in the body, and has good firmness.

[0049] like Figure 3As shown, the bone plate 2 may be provided with a nail hole 21 for accommodating the locking screw 1, and the angle α between the axis M of the locking screw 1 and the axis N of the nail hole 21 may be 0°-20°, that is, the axis M of the locking screw 1 may swing within the range of 0°-20° relative to the axis N of the nail hole 21, so as to facilitate the universal implantation of the locking screw 1 and the self-tapping locking of the locking screw 1 with the polymer bone plate 2. The nail hole 21 may be a countersunk hole to prevent the locking screw 1 from protruding out of the polymer bone plate 2 and avoid unnecessary interference with the soft tissue.

[0050] 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 locking screw, which is made of metal and comprises a nail head, a nail rod and a nail cap from front to back, characterized in that: The nail rod includes a small diameter section as a main body and a large diameter section located behind the small diameter section. The small diameter section is provided with an external thread, and the outer surface of the large diameter section is provided with spiral teeth extending in the front-to-back direction. The spiral teeth are formed by a series of teeth arranged along a spiral line.

2. The 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 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 locking screw.

4. The 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 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 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°.

7. The 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.

8. The locking screw according to claim 1, characterized in that The nail cap is in a step shape, wherein: The maximum diameter of the nail cap is 10mm-3mm; And / or, the minimum diameter of the nail cap is 8mm-2.2mm.

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

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

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