CN220001894U - Bone screw, rod system and tap - Google Patents

Abstract

The application discloses a bone screw, a screw rod system and a screw tap, wherein the bone screw comprises a screw rod and a screw head, the screw head is arranged at a first end of the screw rod, the screw rod comprises a first thread section extending from a second end to the first end, the outer circumferential surface of the first thread section is provided with a first external thread, the outer diameter of one end of the first external thread close to the screw head is larger than the outer diameter of one end of the first external thread far away from the screw head, and an included angle formed by the top line of the first external thread and the central axis of the screw rod is 5-12 degrees; or, the external diameter of the first external thread gradually decreases in the direction from the first end to the second end, and an included angle formed by a tangent line of at least one point of the tooth top line of the first external thread and the central axis of the screw rod is 5-12 degrees, so that the bone screw can be quickly implanted into the screw hole, and the phenomenon of slipping is not easy to occur.

Description

Bone screw, rod system and tap

Technical Field

The application relates to the technical field of medical instruments, in particular to a bone screw, a nail rod system and a screw tap.

Background

In invasive bone surgery, it is often necessary to implant bone screws into the bone of a patient and connect the bone screws with fixation elements such as bone plates, connecting rods, etc. to achieve fixation of the bone. Prior to implantation of a bone screw into a patient's bone, a screw hole is typically formed in the patient's bone, and the bone screw is then threaded into the screw hole by a tool to threadably couple the bone screw to the bone.

However, since the cortical bone of the patient's bone is generally hard, the bone screw is prone to slipping when it is implanted into the screw hole of the bone, resulting in difficulty in initial setting of the bone screw.

Disclosure of Invention

The embodiment of the utility model provides a bone screw, a screw rod system and a screw tap, which aim to solve the problem that when the existing bone screw or screw tap is implanted into a screw hole of a bone of a patient, the bone screw or screw tap is easy to slip, so that initial screw placement of the bone screw or screw tap is difficult.

The embodiment of the utility model provides a bone screw, which comprises a screw rod and a screw head, wherein the screw rod comprises a first end and a second end which are opposite, the screw head is arranged at the first end of the screw rod, the screw rod comprises a first thread section extending from the second end to the first end, the outer periphery of the first thread section is provided with a first external thread, the outer diameter of the first external thread close to one end of the screw head is larger than the outer diameter of the first external thread far away from one end of the screw head, and an included angle formed by the crest line of the first external thread and the central axis of the screw rod is alpha, wherein alpha is more than or equal to 5 degrees and less than or equal to 12 degrees.

The embodiment of the utility model also provides a bone screw, which comprises a screw rod and a screw head, wherein the screw rod comprises a first end and a second end which are opposite, the screw head is arranged at the first end of the screw rod, the screw rod comprises a first thread section extending from the second end to the first end, the outer periphery of the first thread section is provided with a first external thread, the outer diameter of the first external thread is gradually reduced in the direction from the first end to the second end, the tooth crest line of the first external thread comprises a curve section and/or a straight line section, and an included angle formed by a tangent line of at least one point of the curve section and the central axis of the screw rod is theta, wherein theta is more than or equal to 5 degrees and less than or equal to 12 degrees; an included angle formed by the straight line section and the central axis of the screw rod is gamma, wherein gamma is more than or equal to 5 degrees and less than or equal to 12 degrees.

In some embodiments, the length of the first thread segment is greater than or equal to 8mm and the length of the first thread segment is less than or equal to 20mm in a direction from the first end toward the second end.

In some embodiments, the first external thread of the first thread segment is a multi-start thread.

In some embodiments, the first external thread of the first thread segment is a double-start thread; alternatively, the first external thread of the first thread segment is a four-wire thread.

In some embodiments, the screw rod further comprises a second thread section and a third thread section positioned between the first thread section and the screw head, the second thread section and the third thread section are sequentially distributed in the direction from the first thread section to the screw head, the outer circumferential surface of the second thread section is provided with second external threads, the outer circumferential surface of the third thread section is provided with third external threads, and the number of threads of the third external threads is larger than that of the second external threads; the third thread segment includes a transition segment extending from the second thread segment to the screw head, the transition segment having an inner diameter that is the same as an inner diameter of the second thread segment.

In some embodiments, the third threaded section further comprises a reinforcing section extending from the transition section toward the screw head, the reinforcing section having an inner diameter that gradually increases in a direction from the second end toward the first end.

In some embodiments, the outer diameter of the second thread segment and the outer diameter of the third thread segment are the same.

In some embodiments, the second external thread is a double-wire thread and the third external thread is a four-wire thread; at least one thread extends from the second end of the screw shank to an end of the third thread segment adjacent the screw head to form a portion of the first, second and third external threads.

In some embodiments, two threads extend from the second end of the screw shank to an end of the third thread section proximate the screw head to form two threads of the first external thread, two threads of the second external thread, and two threads of the third external thread.

In some embodiments, the bone screw is a pedicle screw.

The embodiment of the application also provides a nail rod system, which comprises:

the screw assembly comprises a screw seat and a bone screw connected with the screw seat, wherein the bone screw comprises a screw rod and a screw head, the screw rod comprises a first end and a second end which are opposite, the screw head is arranged at the first end of the screw rod, the screw rod comprises a first thread section extending from the second end to the first end, the outer circumferential surface of the first thread section is provided with a first external thread, the outer diameter of the first external thread close to one end of the screw head is larger than the outer diameter of the first external thread far away from one end of the screw head, and an included angle formed by the tooth crest line of the first external thread and the central axis of the screw rod is alpha, wherein alpha is more than or equal to 5 degrees and less than 12 degrees; or the outer diameter of the first external thread gradually decreases in the direction from the first end to the second end, the tooth crest line of the first external thread comprises a curve section and/or a straight line section, and an included angle formed by a tangent line of at least one point of the curve section and the central axis of the screw rod is theta, wherein theta is more than or equal to 5 degrees and less than or equal to 12 degrees; an included angle formed by the straight line section and the central axis of the screw rod is gamma, wherein gamma is more than or equal to 5 degrees and less than or equal to 12 degrees;

The connecting rod is used for penetrating through the screw seat;

the screw plug is used for being connected with the screw seat, one end of the screw plug is used for being abutted with the outer peripheral surface of the connecting rod so as to lock the connecting rod, the screw seat and the bone screw together.

The embodiment of the application also provides a tap, which comprises a handle and a conical rod, wherein the handle is arranged at one end of the conical rod, the conical rod comprises a fourth thread section, the fourth thread section extends from one end of the conical rod far away from the handle to the handle, the peripheral surface of the fourth thread section is provided with tapping threads, the outer diameter of the tapping threads is gradually reduced in the direction far away from the handle, and an included angle formed by the tooth crest line of the tapping threads and the central axis of the conical rod is beta, wherein beta is more than or equal to 5 degrees and less than or equal to 12 degrees.

According to the bone screw provided by the embodiment of the application, the first thread section with the first external thread is arranged at the second end of the screw rod, so that the outer diameter of one end of the first external thread close to the screw head is larger than the outer diameter of one end of the first external thread far away from the screw head, and an included angle alpha formed by the tooth crest line of the first external thread and the central axis of the screw rod is 5-12 degrees; or gradually reducing the outer diameter of the first external thread in the direction from the first end to the second end, wherein the tooth crest line of the first external thread comprises a curve section and/or a straight line section, and an included angle theta formed by a tangent line of at least one point of the curve section and the central axis of the screw rod is between 5 and 12 degrees; the included angle gamma formed by the straight line section and the central axis of the screw rod is between 5 and 12 degrees, so that after the second end of the bone screw stretches into a corresponding screw hole, at least half circle of threads of the first external thread are positioned in the screw hole, when no internal thread is arranged in the screw hole, at least two crests on two radial sides of the screw rod are abutted with the inner wall of the screw hole, the crests of the first external thread are cut into the inner wall of the screw hole easily, or when the internal thread is arranged in the screw hole, the first external thread can be quickly screwed into the internal thread of the screw hole, so that the bone screw can be quickly implanted into the screw hole, and the phenomenon of slipping is not easy to occur.

Meanwhile, the screw tap provided by the embodiment of the application has the advantages that the fourth thread section is arranged at one end of the taper rod, which is far away from the handle, so that the outer diameter of the tapping thread of the fourth thread section gradually decreases in the direction, which is far away from the handle, and the included angle formed by the tooth crest line of the tapping thread and the central axis of the taper rod is between 5 degrees and 12 degrees, so that at least half circle of threads of the tapping thread are positioned in the screw hole after one end of the taper rod, which is far away from the handle, of the screw tap extends into the corresponding screw hole, at least two tooth crests positioned at the radial two sides of the taper rod of the tapping thread are abutted with the inner wall of the screw hole, and when the taper rod is screwed by the handle, the tooth crests of the tapping thread of the fourth thread section are relatively easy to cut into the inner wall of the screw hole so as not to easily slip. And when the screw hole is screwed into through the fourth thread section of the screw tap, the internal thread can be tapped into the screw hole, so that when the bone screw is implanted into the screw hole, the external thread of the bone screw can be directly screwed into the internal thread of the screw hole, and the internal thread is not required to be tapped into the screw hole in addition through the external thread of the bone screw, so that the bone screw is implanted into the screw hole more conveniently, and the slipping condition is not easy to occur.

Drawings

The technical solution and other advantageous effects of the present application will be made apparent by the following detailed description of the specific embodiments of the present application with reference to the accompanying drawings.

FIG. 1 is a schematic view of an embodiment of a nail rod system provided by an embodiment of the present application;

FIG. 2 is a cross-sectional view of one embodiment of a screw seat provided in accordance with an embodiment of the present application, taken along the axial direction of the screw seat;

FIG. 3 is a schematic view of one embodiment of a bone screw according to an embodiment of the present application;

FIG. 4 is a cross-sectional view of one embodiment of a bone screw provided in accordance with an embodiment of the present application, taken along the axial direction of the bone screw;

FIG. 5 is a schematic diagram of a prior art bone screw mated with a screw hole in a bone;

fig. 6 is a schematic diagram of the cooperation of a bone screw with a screw hole in a bone according to an embodiment of the present application;

FIG. 7 is a schematic view of a partial construction of another embodiment of a bone screw according to an embodiment of the present application;

FIG. 8 is a schematic view of an embodiment of a tap according to an embodiment of the application;

FIG. 9 is an enlarged view of a portion of the end of the shank of the tap of FIG. 8 distal from the handle.

A nailing rod system 100; a screw assembly 110; a screw seat 111; a mounting hole 1111; an insertion port 1112; a penetrating port 1113; a connecting groove 1114; notch 1115; a bone screw 112; bone screw 112a; a screw shank 1121; screw shank 1121a; a first end 1122; a second end 1123; a second end 1123a; a first threaded section 1124; a first threaded section 1124a; a first external thread 1125; a first external thread 1125a; screw 1125b; a second thread segment 1126; a second external thread 1127; a third thread segment 1128; a third external thread 1129; a transition section 1130; reinforcing section 1131; screw head 1132; a connecting rod 120; a screw plug 130; tap 200; a handle 210; a taper 220; a fourth thread segment 221; tapping thread 2211; a screw-in section 222; a screw thread 2221; junk slots 223; a cutting edge 2231; bone 300; screw holes 310.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to fall within the scope of the application.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

The following disclosure provides many different embodiments, or examples, for implementing different features of the application. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the application. Furthermore, the present application may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present application provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

The embodiment of the application provides a bone screw, a nail rod system and a screw tap. The following will describe in detail.

First, an embodiment of the present application provides a bone screw.

Fig. 1 is a schematic structural view of an embodiment of a nail rod system according to an embodiment of the present application. As shown in fig. 1, the rod system 100 includes a screw assembly 110, a connecting rod 120, and a plug screw 130, wherein the connecting rod 120 is used for connecting with the screw assembly 110, and the plug screw 130 is used for connecting with the screw assembly 110 and the connecting rod 120 to lock the connecting rod 120 and the screw assembly 110 together, thereby preventing the connecting rod 120 from moving relative to the screw assembly 110. Wherein the connecting rod 120 is movable relative to the screw assembly 110 when the screw plug 130 does not lock the connecting rod 120 and the screw assembly 110 together.

With continued reference to fig. 1, the screw assembly 110 includes a screw seat 111, and a bone screw 112 coupled to the screw seat 111, the bone screw 112 for implantation into a pedicle or vertebral body of a patient. The connection rod 120 is used to pass through the screw seat 111 so that the connection rod 120 is connected with the screw assembly 110. The screw plug 130 is used to be connected with the screw seat 111 of the screw assembly 110, and one end of the screw plug 130 is used to abut against the outer circumferential surface of the connecting rod 120 to lock the connecting rod 120, the screw seat 111 and the bone screw 112 together, i.e., to fixedly connect the connecting rod 120 with the screw seat 111 and the bone screw 112 of the screw assembly 110, preventing the connecting rod 120 from moving relative to the screw assembly 110.

Specifically, as shown in fig. 1, 2 and 3, the screw seat 111 is provided with a mounting hole 1111 penetrating therethrough, one end of the mounting hole 1111 (an upper end of the mounting hole 1111 in fig. 2) has an insertion port 1112, and the other end of the mounting hole 1111 (a lower end of the mounting hole 1111 in fig. 2) has a penetrating port 1113. The bone screw 112 includes a screw shaft 1121 and a screw head 1132, the screw shaft 1121 including opposite first and second ends 1122, 1123, the screw head 1132 being disposed at the first end 1122 of the screw shaft 1121. The screw rod 1121 has a diameter smaller than that of the mounting hole 1111 such that the second end 1123 of the screw rod 1121 can be inserted into the mounting hole 1111 from the insertion port 1112 of the mounting hole 1111 and passed out from the passing-out port 1113 of the mounting hole 1111. The screw head 1132 has a diameter smaller than the diameter of the insertion opening 1112 and larger than the diameter of the penetration opening 1113 so that the screw head 1132 can enter from the insertion opening 1112 into the mounting hole 1111 and abut against the inner surface of the mounting hole 1111 without being removed from the penetration opening 1113 of the mounting hole 1111 (i.e., the bone screw 112 as a whole is not removed from under the screw seat 111). Also, screw head 1132 may be rotated within mounting hole 1111 to adjust the angle of inclination of screw shaft 1121 relative to screw seat 111.

The screw seat 111 is further provided with a through connection groove 1114, an extending direction of the connection groove 1114 intersects with an extending direction of the mounting hole 1111, and the connection groove 1114 communicates with the mounting hole 1111. The connection rod 120 passes through the connection groove 1114 in the extending direction of the connection groove 1114 to connect the connection rod 120 with the screw base 111. Wherein screw head 1132 of bone screw 112 is located on the side of connecting rod 120 that faces through-hole 1113.

The screw plug 130 is inserted into the mounting hole 1111 from the insertion hole 1112 of the mounting hole 1111 such that the screw plug 130 is coupled with the screw seat 111 of the screw assembly 110. Further, one end of the screw plug 130 abuts against the outer circumferential surface of the connecting rod 120 on the side away from the head of the bone screw 112 to lock the connecting rod 120. At this time, one end of the screw plug 130 applies a pushing force to the connection rod 120, so that the connection rod 120 and the inner surface of the installation hole 1111 clamp the screw head 1132, preventing the screw head 1132 from rotating in the installation hole 1111, thereby achieving the purpose of fixedly connecting the bone screw 112, the screw seat 111 and the connection rod 120 together.

Wherein, the outer circumference of the screw plug 130 is provided with an external thread, the inner circumference of the installation hole 1111 is provided with an internal thread matching with the external thread of the screw plug 130, and the external thread of the screw plug 130 is connected with the internal thread of the installation hole 1111 by the threads, so that the connection between the screw plug 130 and the screw seat 111 is more stable. Of course, the plug screw 130 and the screw seat 111 may be connected together by a clamping or other manner, and the connecting rod 120 may be locked only by connecting the plug screw 130 with the screw seat 111.

In addition, the connecting groove 1114 of the screw holder 111 is formed with a notch 1115 at a side surface of the screw holder 111 where the insertion port 1112 is opened, so that the connecting rod 120 is placed in the connecting groove 1114 from the notch 1115 of the connecting groove 1114. Of course, the connecting groove 1114 on the screw seat 111 may be a through hole structure penetrating the screw seat 111, and the connecting rod 120 may only need to penetrate the screw seat 111.

In invasive bone surgery, it is often necessary to implant the bone screw 112 into the patient's bone 300 and attach the bone screw 112 to a bone plate, connecting rod 120, or other fixation element for securing the bone 300 to achieve fixation of the bone 300. Prior to implantation of the bone screw 112 into the patient's bone 300, the patient's bone 300 is typically provided with screw holes 310, and the bone screw 112 is then threaded into the screw holes 310 by a tool to threadably couple the bone screw 112 to the bone 300. In the case of a patient's bone 300 where the cortical bone is hard, a screw channel structure may also be tapped into a screw hole 310 in the bone 300 by a tap 200 (shown in fig. 8) to facilitate the external threading of the bone screw 112 into the screw hole 310 along the screw channel structure.

Taking as an example the treatment of diseases such as spinal segmental instability, thoracolumbar fracture dislocation, spinal deformity and the like caused by degenerative diseases by the nail rod system 100: the bone screws 112 can be inserted into different vertebral bodies of a patient after passing through the screw seats 111, then the connecting rod 120 passes through the screw seats 111, the screw plugs 130 are connected to each screw seat 111, after the vertebral bodies implanted with the bone screws 112 are adjusted to proper positions, each screw seat 111 and the bone screws 112 are fixedly connected with the connecting rod 120 through the screw plugs 130, the connecting rod 120 is prevented from moving relative to the bone screws 112, so that the relative positions of the vertebral bodies connected with each bone screw 112 are kept stable, and the purpose of fixing the vertebral columns of the patient is achieved.

As shown in fig. 3, the screw shaft 1121 of the bone screw 112 includes a first threaded section 1124 extending from the second end 1123 toward the first end 1122, the outer circumferential surface of the first threaded section 1124 being provided with a first external thread 1125, and upon implantation of the bone screw 112 into the patient's bone 300, the first external thread 1125 of the first threaded section 1124 is cut into the inner wall of the bone screw 112 corresponding to the screw hole 310 and threadedly engaged with the screw hole 310 by aligning the second end 1123 of the bone screw 112 with the screw hole 310 and then manually or by a tool rotating the bone screw 112 in the screw direction of the first external thread 1125, thereby securing the bone screw 112 with the patient's bone 300.

As shown in fig. 5, the outer diameter of the first threaded section 1124a of the conventional bone screw 112a is substantially constant along the length of the bone screw 112a, and the first threaded section 1124a has an approximately cylindrical configuration. When the second end 1123a of the bone screw 112a is aligned with the screw hole 310, the first external thread of the first thread segment 1124a cannot enter the screw hole 310, usually the first external thread of the first thread segment 1124a abuts against the opening edge of the screw hole 310 at the beginning end of the second end 1123a, and the number of the first external threads of the first thread segment 1124a is smaller at the beginning end of the second end 1123a, so that when the bone screw 112a rotates along the screw direction of the first external thread of the first thread segment 1124a, the first external thread of the first thread segment 1124a is not easy to cut into the inner wall of the screw hole 310 at the beginning end of the second end 1123a, so that the bone screw 112a is easy to slip when being implanted into the screw hole 310, and the initial setting of the bone screw 112a is difficult.

To avoid the above-described problems, in some embodiments, the outer diameter of the end of first external thread 1125 near screw head 1132 is greater than the outer diameter of the end of first external thread 1125 remote from screw head 1132, such that after second end 1123 of bone screw 112 extends into corresponding screw hole 310, at least half of the turns of thread 1125b of first external thread 1125 are located within screw hole 310. Wherein the inner diameter of the screw hole 310 corresponding to the bone screw 112 is smaller than the maximum outer diameter of the first external thread 1125.

In a preferred embodiment, the outer diameter of the first external thread 1125 decreases gradually in the direction from the first end 1122 toward the second end 1123 such that at least half of the turns 1125b of the first external thread 1125 are positioned within the screw hole 310 after the second end 1123 of the bone screw 112 extends into the corresponding screw hole 310.

Compared with the first thread segments 1124a of the existing bone screw 112a, in the embodiment of the application, by making the outer diameter of the first external thread 1125 near one end of the screw head 1132 larger than the outer diameter of the first external thread 1125 far from one end of the screw head 1132, especially when the outer diameter of the first external thread 1125 gradually decreases in the direction from the first end 1122 to the second end 1123, under the condition that the maximum outer diameter of the first thread segments 1124 of the bone screw 112 is unchanged, as shown in fig. 6, the outer diameter of the first thread segments 1124 at the second end 1123 of the bone screw 112 is smaller than that of the first thread segments 1124a of the existing bone screw 112a, so that after the second end 1123 of the bone screw 112 stretches into the corresponding screw hole 310 and abuts against the inner wall of the screw hole 310, at least half of the first external thread 1125b is positioned in the screw hole 310, when no internal thread is arranged in the screw hole 210, the threads 1125b of the first external thread 1125 are positioned at least two tops of the radial sides of the screw rod 112 and at the inner walls of the screw 310, as shown in fig. 6, the first thread segments 1124 are not easily screwed into the screw hole 310, and when the first thread 1125 is not easily screwed into the screw hole 310, the first thread can be easily screwed into the screw hole 112, and the internal thread is easily cut into the screw hole 310 from the inner thread 310, and the inner thread is easily made into the screw hole 310, when the first thread is easily screwed into the screw thread is more easily, and the inner thread is easily, and the inner than the screw threads is easily screwed into the screw threads into the screw thread inner thread threads into the screw threads 310 by the screw threads 310 at the screw threads 1121 at the inner threads and the inner threads 1121 and has is easily when the inner threads and has is made.

Wherein an angle formed by the tooth crest line L1 of the first external thread 1125 and the central axis X1 of the screw shaft 1121 is alpha, and alpha is more than or equal to 5 degrees and less than or equal to 12 degrees. After the second end 1123 of the bone screw 112 extends into the corresponding screw hole 310, at least half-turn of the screw thread 1125b of the first external thread 1125 is located in the screw hole 310, and at least two crests of the screw thread 1125b of the first external thread 1125 located at two radial sides of the screw rod 1121 are abutted against the inner surface of the screw hole 310, so that the screw thread 1125b of the first external thread 1125 of the first thread section 1124 is easier to cut into the inner wall of the screw hole 310, or the first external thread 1125 is easier to screw into the inner thread of the screw hole 310, the bone screw 112 is not easy to slip when being screwed into the screw hole 310, and the initial setting of the bone screw 112 is convenient.

The outer diameter of the first external thread 1125 refers to the nominal diameter of the first external thread 1125, and is also referred to as the large diameter of the first external thread 1125. The crest line L1 of the first external thread 1125 means: a connecting line of points of each crest of the first external thread 1125 on a plane on which the central axis X1 of the bone screw 112 lies.

The crest line L1 of the first male screw 1125 may be a straight line or a curved line. When the crest line L1 of the first external thread 1125 is curved, the angle formed by the crest line L1 of the first external thread 1125 and the central axis X1 of the screw rod 1121 means the angle formed by the tangent line of the crest line L1 and the central axis X1 of the screw rod 1121.

In some embodiments, as shown in FIG. 7, the crest line L1 of the first external thread 1125a may be made to include a curved line segment S1, the tangent to at least one point of the curved line segment S1 forming an angle θ with the central axis X1 of the screw shank 1121a, wherein 5 θ+.ltoreq.θ.ltoreq.12 °. In a preferred embodiment, the tangent to any point of the curved section forms an angle θ with the central axis X1 of the screw shank 1121, where θ is 5+.ltoreq.12 °.

Alternatively, the crest line L1 of the first male screw 1125a includes a straight line segment S2, and the straight line segment S2 forms an angle γ with the central axis X1 of the screw shank 1121a, wherein 5.ltoreq.γ.ltoreq.12 °.

Note that, the crest line L1 of the first external thread 1125 may be entirely linear, or the crest line L1 of the first external thread 1125 may be entirely curved, or the crest line L1 of the first external thread 1125 may be partly curved and partly linear.

The angle formed by the tooth crest line L1 of the first external thread 1125 or a tangent to the tooth crest line L1 and the central axis X1 of the screw shaft 1121 may be specifically 6 °, 10 °, 11 °, or the like. In a preferred embodiment, the included angle formed by the crest line L1 of the first external thread 1125 and the central axis X1 of the screw rod 1121 is 8 °, so that the first external thread 1125 has a larger number of threads 1125b located in the screw hole 310 and has less influence on the structural strength of the bone screw 112, so that the bone screw 112 can be quickly implanted into the patient bone 300 and has better connection stability with the patient bone 300.

The bone screw 112 in the embodiment of the present application may be a hollow bone screw (a through hole penetrating the bone screw 112 in the longitudinal direction of the screw shaft 1121 is provided in the screw shaft 1121 of the bone screw 112) or a solid bone screw (no through hole is provided in the screw shaft 1121 of the bone screw 112).

In some embodiments, the length of the first threaded section 1124 on the screw shaft 1121 is greater than or equal to 8mm in the direction of the first end 1122 of the screw shaft 1121 toward the second end 1123, such that the first threaded section 1124 is of sufficient length to ensure that the first external thread 1125 has at least half a turn of the thread 1125b within the corresponding screw hole 310 while the first external thread 1125 is of sufficient lead such that the first threaded section 1124 of the bone screw 112 can be quickly driven into the screw hole 310 after the thread 1125b of the first external thread 1125 cuts into the inner wall of the screw hole 310, increasing the implantation rate of the bone screw 112. In addition, the length of the first threaded section 1124 is less than or equal to 20mm in the direction of the first end 1122 of the screw shaft 1121 toward the second end 1123 to avoid the length of the first threaded section 1124 being too long, resulting in a reduced length of the external threads on the screw shaft 1121 for threaded connection with the patient's bone 300, thereby reducing the locking force between the bone screw 112 and the patient's bone 300, affecting the stability of the connection of the bone screw 112 to the patient's bone 300.

Wherein, the length of the first thread segments 1124 in the direction from the first end 1122 to the second end 1123 of the screw rod 1121 may be greater than or equal to 8mm and less than or equal to 20mm, so as to ensure that at least half of the threads 1125b of the first external threads 1125 are positioned in the screw hole 310 after the second end 1123 of the bone screw 112 extends into the corresponding screw hole 310, so that the threads 1125b of the first external threads 1125 cut into the inner wall of the screw hole 310, and the first thread segments 1124 of the bone screw 112 can be quickly drilled into the screw hole 310, and meanwhile, the connection between the bone screw 112 and the bone 300 of the patient can be relatively stable.

It should be noted that the length of the first threaded section 1124 on the screw shaft 1121 may be 10mm, 14mm, 18mm, etc. in the direction of the first end 1122 of the screw shaft 1121 toward the second end 1123, depending on the size and type of the bone screw 112. In addition, an included angle formed by the crest line L1 of the first external thread 1125 and the central axis X1 of the screw rod 1121 may be greater than or equal to 5 ° and less than or equal to 12 °, and at the same time, a length of the first thread segments 1124 in a direction from the first end 1122 of the screw rod 1121 toward the second end 1123 may be greater than or equal to 8mm and less than or equal to 20mm, so that the first thread segments 1124 of the bone screw 112 may have a good effect on the anti-slip, the implantation speed, and the connection stability with the bone 300.

In some embodiments, the first external thread 1125 of the first threaded section 1124 of the bone screw 112 is multi-start threads. In the embodiment of the application, the first external thread 1125 of the first thread segment 1124 is made to be multi-thread, so that the second end 1123 of the bone screw 112 has a plurality of thread starting points, and after the first thread segment 1124 extends into the screw hole 310, the first thread segment 1124 has more threads 1125b abutting against the inner wall of the screw hole 310, so that the first thread segment 1124 of the bone screw 112 is easier to cut into the inner wall of the screw hole 310, and slipping is not easy to occur. In addition, by making the first external thread 1125 of the first thread segments 1124 multi-start thread, the lead of each thread will increase with the total number of turns of the thread 1125b of the first thread segments 1124, thereby enabling the first thread segments 1124 of the bone screw 112 to be quickly driven into the screw holes 310, improving the implantation rate of the bone screw 112.

The first external thread 1125 of the first thread segment 1124 of the bone screw 112 includes a plurality of threads, each of which extends helically from the second end 1123 to the first end 1122, and the lead and the helical direction of each of the threads are the same. Alternatively, the thread of the first threaded section 1124 of the bone screw 112 may extend helically from a location between the second end 1123 and the first end 1122 toward the first end 1122.

In some embodiments, the first external thread 1125 of the first threaded section 1124 is a double-start thread. Specifically, the first external thread 1125 of the first thread segment 1124 includes two threads extending helically in the direction of the second end 1123 toward the first end 1122, both threads having the same lead and helical direction. Wherein the two threads are symmetrically disposed about the central axis X1 of the bone screw 112. Therefore, when the two threads of the first thread section 1124 cut into the inner wall of the screw hole 310, the resistance force received by the first thread section 1124 is symmetrically distributed in the radial direction of the bone screw 112, so that the problem that the bone screw 112 is unbalanced in stress and slipping or tilting when the bone screw 112 is drilled into the screw hole 310 due to the fact that only one side thread of the first thread section 1124 of the bone screw 112 cuts into the inner wall of the screw hole 310 is effectively avoided.

In other embodiments, the first external thread 1125 of the first thread segment 1124 may also be four-wire threads, such that the first external thread 1125 has more threads 1125b that abut against the inner wall of the screw hole 310, thereby making it easier for the first external thread 1125 to cut into the inner wall of the screw hole 310. In addition, when the first external thread 1125 is a four-wire thread, the lead of each thread of the first external thread 1125 is greater with the pitch of the first external thread 1125 unchanged, thereby enabling the first thread segments 1124 to be drilled into the screw holes 310 at a faster rate. Specifically, the first external thread 1125 of the first thread segment 1124 includes four threads extending helically in the direction of the second end 1123 toward the first end 1122, the leads and helical directions of the four threads being the same. Wherein the four thread loops are evenly distributed about the central axis X1 of the bone screw 112. Therefore, when the four threads of the first thread section 1124 cut into the inner wall of the screw hole 310, the resistance force received by the first thread section 1124 is uniformly distributed in the radial direction of the bone screw 112, so that the problem that the bone screw 112 is unbalanced in stress and slipping or tilting when the bone screw 112 is drilled into the screw hole 310 due to the fact that only one side thread of the first thread section 1124 of the bone screw 112 cuts into the inner wall of the screw hole 310 is effectively avoided.

As shown in fig. 3 and 4, the screw shaft 1121 of the bone screw 112 further includes a second thread segment 1126 and a third thread segment 1128 between the first thread segment 1124 and the screw head 1132, the second thread segment 1126 and the third thread segment 1128 being sequentially distributed in the direction of the first thread segment 1124 toward the screw head 1132, the outer circumferential surface of the second thread segment 1126 being provided with a second external thread 1127, and the outer circumferential surface of the third thread segment 1128 being provided with a third external thread 1129. After screwing the screw shank 1121 into the screw hole 310, the second external threads 1127 of the second threaded section 1126 and the third external threads 1129 of the third threaded section 1128 of the screw shank 1121 are threadedly coupled to the inner wall of the screw hole 310 to fixedly couple the bone screw 112 to the patient's bone 300.

In some embodiments, the number of threads of the third external thread 1129 is greater than the number of threads of the second external thread 1127. It is understood that the patient's bone 300 generally includes cortical bone at the surface of the bone 300 and cancellous bone at the interior of the bone 300, the cortical bone having a hardness greater than the hardness of the cancellous bone. After the bone screw 112 is screwed into the screw hole 310 of the bone 300, the second external thread 1127 of the second thread 1126 of the screw rod 1121 is screwed with the cancellous bone, the third external thread 1129 of the third thread 1128 is screwed with the cortical bone, and the third external thread 1129 of the third thread 1128 is screwed with the cortical bone by making the number of threads of the third external thread 1129 larger than the number of threads of the second external thread 1127, so that the third external thread 1129 of the third thread 1128 is screwed with the cortical bone more firmly, the extraction force of the bone screw 112 is improved, and the bone screw 112 is connected with the bone 300 of a patient more stably.

In some embodiments, the number of threads of the third external thread 1129 is twice the number of threads of the second external thread 1127. Specifically, the second external thread 1127 is a double-wire thread and the third external thread 1129 is a four-wire thread to optimize the stability of the connection of the bone screw 112 to the patient's bone 300.

As shown in fig. 3, third thread segment 1128 includes a transition section 1130 extending from second thread segment 1126 to screw head 1132. In some embodiments, the inner diameter of the transition section 1130 is the same as the inner diameter of the second threaded section 1126. Thus, abrupt changes in the inner diameter of the junction of the second and third thread segments 1126, 1128 of the bone screw 112 can be avoided, resulting in stress concentration in the bone screw 112 at the junction of the second and third thread segments 1126, 1128, reducing the risk of bending or even breaking at the junction of the second and third thread segments 1126, 1128 during clinical use of the bone screw 112.

The inner diameter of the transition section 1130 refers to the bottom diameter, also referred to as the root diameter, of the third external thread 1129 of the third thread section 1128 at the transition section 1130.

In other embodiments, the inner diameter of the transition section 1130 near one end of the second threaded section 1126 may be the same as the inner diameter of the second threaded section 1126, and the inner diameter of the transition section 1130 gradually increases or decreases in the direction from the second end 1123 to the first end 1122 of the screw shaft 1121, with the inner diameter of the second threaded section 1126 gradually increasing or decreasing to avoid abrupt changes in the inner diameter at the interface of the second and third threaded sections 1126, 1128, resulting in stress concentration in the bone screw 112 at the interface of the second and third threaded sections 1126, 1128.

With continued reference to fig. 3 and 4, the third threaded section 1128 further includes a reinforcing section 1131 extending from the transition section 1130 toward the screw head 1132, the reinforcing section 1131 having an inner diameter that gradually increases in the direction of the second end 1123 of the screw shaft 1121 toward the first end 1122. Thereby, the structural strength of the reinforcement section 1131 of the screw rod 1121 can be improved, the overall strength of the bone screw 112 can be further improved, and the risk of bending and even breaking of the bone screw 112 during clinical use can be reduced.

The inner diameter of the reinforcing section 1131 near one end of the transition section 1130 is the same as the inner diameter of the transition section 1130, so as to avoid abrupt change of the inner diameter at the junction of the transition section 1130 and the reinforcing section 1131 of the bone screw 112, thereby causing the stress of the bone screw 112 to concentrate at the junction of the transition section 1130 and the reinforcing section 1131, and reducing the risk of bending or breaking at the junction of the transition section 1130 and the reinforcing section 1131 of the bone screw 112.

In some embodiments, the outer diameter of the second threaded section 1126 and the outer diameter of the third threaded section 1128 of the bone screw 112 are the same to provide the bone screw 112 with greater structural strength.

In some embodiments, at least one thread extends from the second end 1123 of the screw shank 1121 to an end of the third thread segment 1128 proximate the screw head 1132 to form a portion of the first external thread 1125, the second external thread 1127, and the third external thread 1129.

Thus, at least one complete thread extends from the first thread segment 1124 through the second thread segment 1126 to the third thread segment 1128, and when the thread of the first external thread 1125 of the first thread segment 1124 is cut into the inner wall of the screw hole 310 to form a tack hole, at least one thread of the first external thread 1125 can be directly screwed into the tack hole without being cut into the inner wall of the screw hole 310, so that the second thread segment 1126 of the bone screw 112 can be more easily introduced into the screw hole 310 and screwed with the inner wall of the screw hole 310.

Likewise, at least one of the third external threads 1129 can also be threaded directly into the shank without additional cutting into the interior wall of the screw hole 310, allowing the third threaded section 1128 of the bone screw 112 to more easily enter the screw hole 310 and be threadably coupled to the interior wall of the screw hole 310.

Specifically, there are two threads extending from the second end 1123 of the screw shank 1121 to the end of the third thread segment 1128 adjacent the screw head 1132 to form two threads of the first external thread 1125, two threads of the second external thread 1127, and two threads of the third external thread 1129. The third threaded section 1128 further has two additional threads extending helically along the length of the screw shank 1121 such that the third external thread 1129 of the third threaded section 1128 is a four-wire thread.

In some embodiments, the bone screw 112 is a pedicle screw. Thus, when bone screw 112 is used in rod system 100, pedicle screws are more easily implanted into the spine and are less prone to slipping. Of course, bone screw 112 may also be a screw for other invasive bone surgery, such as: bone screw 112 is a screw used to secure the bone plate to the patient's bone 300.

The embodiment of the application also provides a rod nailing system, which comprises a bone screw, and the specific structure of the bone screw refers to the embodiment, and because the rod nailing system adopts all the technical schemes of all the embodiments, the rod nailing system at least has all the beneficial effects brought by the technical schemes of the embodiments, and the description is omitted herein.

The screw rod system 100 comprises a screw assembly 110, a connecting rod 120 and a screw plug 130, wherein the screw assembly 110 comprises a screw seat 111 and a bone screw 112 connected with the screw seat 111. The connection rod 120 is used to pass through the screw seat 111. The screw plug 130 is used for being connected with the screw seat 111, and one end of the screw plug 130 is abutted against the outer circumferential surface of the connecting rod 120, so that the connecting rod 120 locks the screw seat 111 and the bone screw 112. The structure of the screw seat 111, the connecting rod 120, the plug 130 and the bone screw 112 can be referred to the above embodiments, and will not be described herein.

Before the bone screw 112 is implanted into the screw hole 310 of the patient's bone 300, for the case where the cortical bone of the patient's bone 300 is hard, the tap 200 may be first screwed into the screw hole 310, the tap 200 may have internal threads (also referred to as lanes) pre-cut into the inner wall of the screw hole 310, and then the bone screw 112 may be screwed into the screw hole 310, with external threads on the bone screw 112 entering the internal threads of the screw hole 310, so as to reduce the force required to screw the bone screw 112 into the screw hole 310, and to facilitate implantation of the bone screw 112.

The embodiment of the application also provides a tap. As shown in fig. 8 and 9, the tap 200 includes a handle 210 and a shank 220, the handle 210 being disposed at one end of the shank 220, the shank 220 including a fourth threaded section 221, the fourth threaded section 221 being disposed at an end of the shank 220 remote from the handle 210. The fourth threaded section 221 of the tapered rod 220 can be conveniently screwed into the screw hole 310 by the handle 210, and the internal thread is tapped into the inner wall of the screw hole 310.

A fourth thread segment 221 extends from an end of the taper rod 220 away from the handle 210 toward the handle 210, and an outer circumferential surface of the fourth thread segment 221 is provided with a tapping thread 2211. By inserting a portion of the fourth threaded section 221 into the screw hole 310 and rotating the taper 220 by the handle 210, the tapping thread 2211 of the fourth threaded section 221 is cut into the inner wall of the screw hole 310 and a tack path is formed in the inner wall of the screw hole 310.

Wherein the outer diameter of the tapping thread 2211 gradually decreases in a direction away from the handle 210. The angle formed by the crest line L2 of the tapping thread 2211 and the central axis X2 of the taper rod 220 is beta, wherein beta is more than or equal to 5 degrees and less than or equal to 12 degrees. Therefore, after the end of the taper rod 220 away from the handle 210 extends into the corresponding screw hole 310 and abuts against the inner wall of the screw hole 310, at least half-turn threads of the tapping thread 2211 of the fourth thread section 221 are located in the screw hole 310, and at least two crests of the threads of the tapping thread 2211 located at two radial sides of the screw rod 1121 abut against the inner surface of the screw hole 310, so that the threads of the tapping thread 2211 are easier to cut into the inner wall of the screw hole 310 without slipping, thereby facilitating rapid cutting of the internal threads into the screw hole 310 by the tapping thread 2211 of the tap 200.

When the fourth thread segment 221 of the tap 200 is screwed into the screw hole 310, the internal thread can be tapped into the screw hole 310, so that the external thread of the bone screw 112 can be directly screwed into the internal thread of the screw hole 310 when the bone screw 112 is implanted into the screw hole 310, and the external thread of the bone screw 112 does not need to tap the internal thread into the screw hole 310, so that the bone screw 112 is more conveniently implanted into the screw hole 310 and slipping is not easy to occur.

The outer diameter of the tapping thread 2211 refers to the nominal diameter of the tapping thread 2211, and is also referred to as the large diameter of the tapping thread 2211. The crest line L2 of the tapping thread 2211 means: the crests of the tapping threads 2211 are joined at points on the plane in which the central axis X2 of the shank 220 lies.

The included angle β formed by the crest line L2 of the tapping thread 2211 and the central axis X2 of the taper rod 220 may be specifically 6 °, 10 °, 11 °, and the like. In a preferred embodiment, the angle β formed by the crest L2 of the tapping thread 2211 and the central axis X2 of the shank 220 may be 8 ° so that the tapping thread 2211 has a greater number of threads located in the screw hole 310 and has less impact on the structural strength of the fourth thread segment 221 of the shank 220.

The crest line L2 of the tapping thread 2211 may be a straight line or a curved line. When the crest line L2 of the tapping thread 2211 is curved, the angle formed by the crest line L2 of the tapping thread 2211 and the central axis X2 of the taper rod 220 means the angle formed by the tangent line of the crest line L2 and the central axis X2 of the taper rod 220.

Specifically, the crest line L2 of the tapping thread 2211 includes a curved line segment and/or a straight line segment, and an included angle formed by a tangent line of at least one point of the curved line segment of the crest line L2 and the central axis X2 of the taper rod 220 is 5 ° -12 °; the straight line segment of the tooth crest line L2 forms an angle of 5 ° -12 ° with the central axis X2 of the taper rod 220.

In some embodiments, as shown in fig. 9, the outer circumferential surface of the tapered rod 220 is further provided with a chip groove 223, the chip groove 223 extends from an end of the tapered rod 220 away from the handle 210 toward the handle 210, and the chip groove 223 intersects with the thread of the tapping thread 2211 to intercept the thread of the tapping thread 2211, and a cutting edge 2231 is formed at a section where the thread of the tapping thread 2211 is intercepted, so that the thread of the tapping thread 2211 cuts into an inner wall of the screw hole 310 through the cutting edge 2231, and chips cut off by the tapping thread 2211 are discharged from the screw hole 310 through the chip groove 223.

With continued reference to fig. 9, the taper rod 220 further includes a screwing section 222 extending from an end of the fourth screw section 221 near the handle 210 toward the handle 210, and a screwing thread 2221 is provided on an outer peripheral surface of the screwing section 222. Further cutting of the initially cut lanes of tap threads 2211 can be performed by screwing in threads 2221 to facilitate easier entry of the external threads on the corresponding bone screw 112 into the lanes of the bone screw 112.

The chip groove 223 intersects with the thread of the screw-in thread 2221 to intercept the thread of the screw-in thread 2221 and form a cutting edge 2231 at a cross section of the thread of the screw-in thread 2221 at the thread-intercept position so that the thread of the screw-in thread 2221 cuts into the inner wall of the screw hole 310 through the cutting edge 2231 and chips cut off by the screw-in thread 2221 are discharged from the screw hole 310 through the chip groove 223. Wherein the crest line L3 of the screwing thread 2221 is parallel to the central axis X2 of the taper rod 220.

In some embodiments, the tapping thread 2211 is a double-line thread and is symmetrically disposed about the central axis X2 of the tap 220, so that when two threads of the tapping thread 2211 cut into the inner wall of the screw hole 310, the resistance force applied to the fourth thread segment 221 is symmetrically distributed in the radial direction of the bone screw 112, which effectively avoids the problem that the tap 200 is stressed in an unbalanced manner due to the fact that only one side thread of the fourth thread segment 221 of the tap 200 cuts into the inner wall of the screw hole 310, and thus the fourth thread segment 221 of the tap 200 slips or tilts when drilling into the screw hole 310. The lead angles and leads of the two threads of the tapping thread 2211 are equal.

Likewise, the screwing thread 2221 is a double-thread, and is symmetrically disposed about the central axis X2 of the taper rod 220. The two threads of the screw thread 2221 are connected with the two threads of the tapping thread 2211 in one-to-one correspondence, and the lead angles and leads of the two threads of the screw thread 2221 and the two threads of the tapping thread 2211 are equal.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and for parts of one embodiment that are not described in detail, reference may be made to related descriptions of other embodiments.

The bone screw, the rod system and the tap provided by the embodiment of the application are described in detail, and specific examples are applied to the principle and the implementation of the application, and the description of the above examples is only used for helping to understand the technical scheme and the core idea of the application; those of ordinary skill in the art will appreciate that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.

Claims (12)

1. A bone screw comprising a screw shaft including opposed first and second ends and a screw head disposed at the first end of the screw shaft;

the screw rod comprises a first thread section extending from the second end to the first end, a first external thread is arranged on the outer peripheral surface of the first thread section, the outer diameter of the first external thread close to one end of the screw head is larger than the outer diameter of the first external thread far away from one end of the screw head, and an included angle alpha is formed between the tooth crest line of the first external thread and the central axis of the screw rod, wherein the included angle alpha is more than or equal to 5 degrees and less than or equal to 12 degrees.

2. A bone screw comprising a screw shaft including opposed first and second ends and a screw head disposed at the first end of the screw shaft;

the screw rod comprises a first thread section extending from the second end to the first end, a first external thread is arranged on the outer peripheral surface of the first thread section, the outer diameter of the first external thread gradually decreases in the direction from the first end to the second end, the tooth crest line of the first external thread comprises a curve section and/or a straight line section, and an included angle formed by a tangent line of at least one point of the curve section and the central axis of the screw rod is theta, wherein theta is more than or equal to 5 degrees and less than or equal to 12 degrees; an included angle formed by the straight line section and the central axis of the screw rod is gamma, wherein gamma is more than or equal to 5 degrees and less than or equal to 12 degrees.

3. The bone screw of claim 1 or 2, wherein the length of the first threaded section is greater than or equal to 8mm in a direction from the first end toward the second end, and the length of the first threaded section is less than or equal to 20mm.

4. The bone screw of claim 1 or 2, wherein the first external thread of the first threaded section is a multi-start thread.

5. The bone screw of claim 4, wherein the first external thread of the first threaded section is a double-start thread; alternatively, the first external thread of the first thread segment is a four-wire thread.

6. The bone screw of claim 1 or 2, wherein the screw shank further comprises a second thread section and a third thread section between the first thread section and the screw head, the second thread section and the third thread section being distributed sequentially in the direction of the first thread section towards the screw head;

the outer peripheral surface of the second thread section is provided with second external threads, the outer peripheral surface of the third thread section is provided with third external threads, and the number of threads of the third external threads is larger than that of the second external threads; the third thread segment includes a transition segment extending from the second thread segment to the screw head, the transition segment having an inner diameter that is the same as an inner diameter of the second thread segment.

7. The bone screw of claim 6, wherein the third threaded section further comprises a reinforcing section extending from the transition section toward the screw head, the reinforcing section having an inner diameter that gradually increases in a direction from the second end toward the first end.

8. The bone screw of claim 6, wherein the second external thread is a double-wire thread and the third external thread is a four-wire thread; at least one thread extends from the second end of the screw shank to an end of the third thread segment adjacent the screw head to form a portion of the first, second and third external threads.

9. The bone screw of claim 8, wherein two threads extend from the second end of the screw shank to an end of the third thread segment adjacent the screw head to form two threads of the first external thread, two threads of the second external thread, and two threads of the third external thread.

10. The bone screw of claim 1 or 2, wherein the bone screw is a pedicle screw.

11. A pin system, the pin system comprising:

A screw assembly comprising a screw seat, and a bone screw connected to the screw seat, the bone screw being a bone screw according to any one of claims 1 to 10;

the connecting rod is used for penetrating through the screw seat;

the screw plug is used for being connected with the screw seat, one end of the screw plug is used for being abutted with the outer peripheral surface of the connecting rod so as to lock the connecting rod, the screw seat and the bone screw together.

12. The utility model provides a screw tap, its characterized in that, the screw tap includes handle and awl pole, the handle set up in the one end of awl pole, the awl pole includes fourth screw thread section, fourth screw thread section is from the awl pole is kept away from the one end of handle to the handle extends, the outer peripheral face of fourth screw thread section is equipped with the tapping screw thread, the external diameter of tapping screw thread is in keeping away from the direction of handle gradually reduces, the tip line of tapping screw thread with the contained angle that the central axis of awl pole formed is beta, wherein, is less than or equal to 5 the beta is less than or equal to 12.