CN114376699A

CN114376699A - Bone screw

Info

Publication number: CN114376699A
Application number: CN202111140281.7A
Authority: CN
Inventors: 赖弘基; 黄信华
Original assignee: Botai Shengyi Co ltd
Current assignee: Botai Shengyi Co ltd
Priority date: 2020-10-05
Filing date: 2021-09-28
Publication date: 2022-04-22
Also published as: TW202214189A; TWI775172B

Abstract

A bone screw comprises a shank and a head. The nail pole includes tip section, and is formed in the first screw thread section of tip section one end, the tip section have the tip, by the tip extends and a plurality of cutting edges of equiangular interval range, and be formed at respectively a plurality of back knife face of cutting edge rear side, the tip is the circular arc terminal surface, the definition respectively the cutting plane of any point on the cutting edge with correspond press from both sides a back bevel angle between the back knife face, the nail pole be formed with by the tip extends to a plurality of chip grooves of first screw thread section, each the chip groove is the heliciform. A head is formed at an end of the first threaded section opposite the tip section, the head including a second threaded section. Thereby enabling the tip section to function as a drilling hole. The end part is an arc end surface, so that other tissues can be prevented from being punctured.

Description

Bone screw

Technical Field

The present invention relates to a surgical instrument, and more particularly to a self-drilling and self-tapping bone screw for implantation in a bone.

Background

When a bone plate is fixed to a fractured bone by a plurality of bone screws, the screwing operation of the bone screws is performed in sequence. To effect the screwing of the respective bone screw, a guide sleeve is first locked to the bone plate, and a drill is then inserted into the guide sleeve and guided through it to drill a hole in the bone. Then, whether the depth of the drilled hole on the bone is in accordance with the requirement is measured. Finally, a self-tapping type bone screw is arranged in the bone plate in a penetrating mode and locked into the bone corresponding to the drilling position of the bone, and therefore the screwing operation of the single bone screw is completed.

Since the screwing operation of each bone screw can be completed through the above-mentioned multiple operation steps, and each two adjacent bone screws can only be implemented within a range of angles with a small difference, a long operation time is required.

In addition, self-drilling and self-tapping screws are used to replace the self-tapping screws, thereby eliminating the above-mentioned steps. However, such self-drilling and self-tapping bone screws have a sharp tip, and therefore, the tip is easily damaged by other tissues after penetrating the bone.

Disclosure of Invention

It is, therefore, an object of the present invention to provide a bone screw that overcomes at least one of the shortcomings of the background art.

The invention aims to solve the technical problems and solves the background technical problems by adopting the following technical scheme, the bone screw provided by the invention comprises a screw rod and a screw head, the screw rod comprises a tip section and a first thread section formed at one end of the tip section, the tip section is provided with an end part, a plurality of cutting edges which extend from the end part and are arranged at equal angle intervals, and a plurality of rear tool faces which are respectively formed at the rear sides of the cutting edges, the end part is an arc end face, a rear oblique angle is formed between a cutting plane at any point on each cutting edge and the corresponding rear tool face, the screw rod is provided with a plurality of chip grooves which extend from the end part to the first thread section, each chip groove is in a spiral shape, the screw head is formed at one end of the first thread section opposite to the tip section, and the screw head comprises a second thread section.

In the bone screw, each flank surface is an arc surface connected with the end part.

According to the bone screw, the number of the cutting edges is three, every two adjacent cutting edges are separated by an angle, and the angle is 120 degrees.

The bone screw has an overall length defined by the shank and the head, the number of the chip flutes is three, and the length of each chip flute extending from the end to the first thread section is between one fourth of the overall length and one half of the overall length.

The invention has the beneficial effects that: the tip section can play a role of drilling into the bone smoothly by virtue of the design of the cutting edge and the back bevel. Due to the design that the chip grooves extend from the end part to the first thread section, bone chips generated by the tip section in the drilling process and the first thread section in the tapping process can be discharged into the chip grooves and stored in the chip grooves. By means of the design mode that the end part is an arc end surface and each rear cutter surface is an arc surface, other tissues on the side surface of the bone can be prevented from being punctured.

Drawings

FIG. 1 is a front view of an embodiment of the bone screw of the present invention illustrating the relationship between a shank and a head;

FIG. 2 is a side view of the embodiment illustrating the relationship between an end, cutting edges, relief surfaces, and flutes;

FIG. 3 is a fragmentary cross-sectional view of a tip section of the embodiment;

FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 1; and

fig. 5 is a schematic view of the embodiment locking a bone plate to a bone.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and examples.

Before the present invention is described in detail, it should be noted that in the following description, like elements are represented by like reference numerals.

Referring to fig. 1, in one embodiment of the bone screw 100 of the present invention, the bone screw 100 is a self-drilling and self-tapping bone screw and includes a shank 1 and a head 2.

Referring to fig. 1, 2 and 3, the nail shank 1 includes a tip section 11 and a first threaded section 12 formed at one end of the tip section 11. The tip section 11 has an end 111, a plurality of cutting edges 112, and a plurality of relief surfaces 113. The end 111 of this embodiment is a circular end. The cutting blades 112 extend from the end 111 and are arranged at equal angular intervals. In the present embodiment, the number of the cutting edges 112 and the number of the flank surfaces 113 are three, and each two adjacent cutting edges 112 are separated by an angle a, where the angle a is 120 degrees. The flank surfaces 113 are formed behind the cutting edges 112, respectively, and each flank surface 113 is an arc surface connected to the end portion 111. A back bevel angle θ is formed between a cutting plane P defining any point on each cutting edge 112 and the corresponding flank surface 113, and the back bevel angle θ in this embodiment is, for example, between 0 degree and 5 degrees.

Referring to fig. 1, 2 and 4, the nail shank 1 is formed with a plurality of chip flutes 13 extending from the end 111 to the first thread section 12, and each chip flute 13 is helical. The number of flutes 13 in this embodiment is three, for example. The head 2 is formed at an end of the first thread section 12 opposite the tip section 11, the head 2 comprising a second thread section 21. The stud 2 is formed with a blind hole 22 for insertion of a screwdriver. The bone screw 100 has an overall length L defined by the shank 1 and the head 2, and a length D of each chip groove 13 extending from the end 111 to the first threaded section 12 is between one quarter of the overall length L and one half of the overall length L.

Referring to fig. 1, 2 and 5, to lock a bone plate 3 to a bone 4 by the bone screw 100, the tip section 11 of the shank 1 is inserted through a screw hole 31 of the bone plate 3 and drilled into a lateral surface 41 of the bone 4. Due to the design of the cutting edge 112 and the back bevel θ (as shown in fig. 3), the resistance of the tip section 11 when screwing into the bone 4 can be greatly reduced, so that the tip section 11 can smoothly drill into the bone 4. The first thread segments 12 are then threaded into the bone 4 and locked into the bone 4. In this embodiment, the cutting effect of cutting the bone 4 can be improved by setting the number of the cutting edges 112 to three. Of course, in other embodiments of the present embodiment, the number of the cutting edges 112 may be two or more than three, and is not limited to the number disclosed in the present embodiment.

Due to the design of the chip flutes 13 extending from the end 111 to the first thread segments 12, bone chips produced by the tip section 11 during drilling and the first thread segments 12 during tapping can be discharged into the chip flutes 13 and stored therein. Furthermore, by means of the design manner that the length D of each chip groove 13 extending from the end 111 to the first thread section 12 is between one fourth of the total length L and one half of the total length L, it can be ensured that after the first thread section 12 is completely tapped into the bone 4, bone fragments can be completely accumulated and contained in the chip groove 13, thereby avoiding waste of the bone fragments and preventing the bone fragments from being discharged randomly to cause environmental pollution. In the present embodiment, the three chip pockets 13 are provided to increase the capacity of accommodating bone fragments. Of course, in other embodiments of this embodiment, the number of the chip flutes 13 may be two or three or more, and is not limited to the number disclosed in this embodiment.

Finally, when the second threaded section 21 of the stud 2 is threadedly engaged in the threaded hole 31 of the bone plate 3, the bone screw 100 locks the bone plate 3 to the side 41 of the bone 4. In this case, the end 111 of the tip section 11 or the end 111 and a portion of each flank surface 113 protrude a short distance from the other side surface 42 of the bone 4, and fig. 5 illustrates an example in which the end 111 and a portion of each flank surface 113 protrude from the side surface 42 of the bone 4, and the design in which the end 111 is a circular arc end surface and each flank surface 113 is a circular arc surface can prevent the end 111 or each flank surface 113 from pricking other tissues at the side surface 42 of the bone 4.

In summary, in the bone screw 100 of the present embodiment, the tip section 11 can smoothly drill the hole in the bone 4 by the design of the cutting edge 112 and the back bevel angle θ. Due to the design of the chip flutes 13 extending from the end 111 to the first thread segments 12, bone chips produced by the tip section 11 during drilling and the first thread segments 12 during tapping can be discharged into the chip flutes 13 and stored therein. By the design of the end 111 being an arc end surface and the flank surfaces 113 being arc surfaces, other tissues on the side surface 42 of the bone 4 can be prevented from being punctured, and the object of the present invention can be achieved.

Claims

1. A bone screw, characterized by:

the bone screw comprises a screw rod and a screw head, wherein the screw rod comprises a tip section and a first thread section formed at one end of the tip section, the tip section is provided with an end part, a plurality of cutting edges which extend from the end part and are arranged at equal angles at intervals, and a plurality of rear tool faces formed at the rear sides of the cutting edges respectively, the end part is an arc end face, a rear oblique angle is clamped between a cutting plane at any point on each cutting edge and the corresponding rear tool face, the screw rod is provided with a plurality of chip grooves extending from the end part to the first thread section, each chip groove is in a spiral shape, the screw head is formed at one end opposite to the tip section of the first thread section, and the screw head comprises a second thread section.

2. The bone screw of claim 1, wherein: each rear cutter face is an arc surface connected with the end part.

3. The bone screw of claim 1, wherein: the quantity of cutting edge is three, every two adjacent interval angle between the cutting edge, the angle is 120 degrees.

4. The bone screw of claim 2, wherein: the quantity of cutting edge is three, every two adjacent interval angle between the cutting edge, the angle is 120 degrees.

5. The bone screw according to any one of claims 1 to 4, wherein: the bone screw has an overall length defined by the shank and the head, the number of the chip flutes is three, and the length of each chip flute extending from the end portion to the first thread section is between one quarter of the overall length and one half of the overall length.