Thread form for bone screw
阅读说明:本技术 用于骨螺钉的螺纹形式 (Thread form for bone screw ) 是由 J·威克汉姆 M·达斯 于 2020-04-10 设计创作,主要内容包括:提供了一种包括头部、颈部和轴部的骨螺钉。所述轴部包括第一端、相对的第二端、螺旋状螺纹形式和柄。所述轴部的所述第一端附接到所述颈部,并且所述螺旋状螺纹形式在所述第一端和所述第二端之间围绕所述柄延伸。所述螺纹形式在邻近所述轴部的所述第一端的螺纹终止表面处终止,其中所述螺纹终止表面突然过渡到所述柄中。(A bone screw is provided that includes a head portion, a neck portion, and a shaft portion. The shaft portion includes a first end, an opposite second end, a helical thread form, and a shank. The first end of the shaft portion is attached to the neck portion, and the helical thread form extends around the shank between the first end and the second end. The thread form terminates at a thread termination surface adjacent the first end of the shaft portion, wherein the thread termination surface abruptly transitions into the shank.)
1. A bone screw, comprising:
a trailing end, an opposite leading end, and a central axis extending through the trailing end and the leading end;
a head extending from the trailing end toward the leading end;
a neck attached to the head and extending from the head toward the front end; and
a shaft attached to and extending from the neck to the leading end, the shaft comprising a first end attached to the neck, an opposing second end juxtaposed with the leading end, a helical thread form, and a shank, the helical thread form extending around the shank between the first end and the second end;
Wherein the thread form terminates at a thread termination surface adjacent the first end of the shaft portion, and wherein the thread termination surface abruptly transitions into the shank within less than half a turn of the shaft portion.
2. The bone screw of claim 1 wherein said helical thread includes a first major diameter in a direction perpendicular to said central axis, said first major diameter being adjacent said thread termination surface, said thread termination surface extending inwardly from said first major diameter to said shank.
3. The bone screw of claim 2 wherein said thread termination surface comprises a first surface portion and a second surface portion, said first surface portion extending from said first major diameter to said second surface portion, and said second surface portion transitioning into said shank.
4. The bone screw of claim 3 wherein said first surface portion comprises a flat surface portion and said second surface portion comprises a curved surface portion.
5. The bone screw of claim 2 wherein said thread form includes a face facing said head and said face includes a relief cut adjacent said thread stop surface.
6. The bone screw of claim 2, wherein the thread form comprises a face facing the head, and at least a portion of the face is oriented approximately 90 ° from the central axis of the bone screw.
7. The bone screw of claim 2, wherein the thread form includes a second major diameter in a direction perpendicular to the central axis, the second major diameter being positioned between the first end and the second end of the shaft portion, and the first major diameter being substantially equal to the second major diameter.
8. The bone screw of claim 6, wherein the thread form includes a third major diameter in a direction perpendicular to the central axis, the third major diameter being positioned adjacent the second end of the shaft portion, the first major diameter and the second major diameter each being larger than the third major diameter.
9. The bone screw of claim 1, wherein the head comprises a tool engagement recess, and the bone screw is insertable into bone via the tool engagement recess via a rotational force applied to the recess.
10. A bone screw, comprising:
a trailing end, an opposite leading end, and a central axis extending through the trailing end and the leading end;
A head extending from the trailing end toward the leading end;
a neck attached to the head and extending from the head toward the front end; and
a shaft attached to and extending from the neck to the leading end, the shaft comprising a first end attached to the neck, an opposing second end juxtaposed with the leading end, and a shank extending around the shank between the first end and the second end, a helical thread form continuous around the shank and having a variable height relative to the central axis in a direction perpendicular to the central axis;
wherein the thread form terminates at a thread termination surface adjacent the first end of the shaft portion, and wherein the thread termination surface abruptly transitions into the shank within less than half a turn of the shaft portion.
11. The bone screw of claim 10 wherein said helical thread includes a first major diameter in a direction perpendicular to said central axis, said first major diameter being adjacent said thread termination surface, said thread termination surface extending inwardly from said first major diameter to said shank.
12. The bone screw of claim 11 wherein said thread stop surface comprises a first surface portion and a second surface portion, said first surface portion extending from said first major diameter to said second surface portion, and said second surface portion transitioning into said shank.
13. The bone screw of claim 12 wherein said first surface portion comprises a flat surface portion and said second surface portion comprises a curved surface portion.
14. The bone screw of claim 11 wherein said thread form includes a face facing said head and said face includes a relief cut adjacent said thread stop surface.
15. The bone screw of claim 11, wherein the thread form comprises a face facing the head, and at least a portion of the face is oriented approximately 90 ° from the central axis of the bone screw.
16. The bone screw of claim 11, wherein the thread form includes a second major diameter relative to the central axis in a direction perpendicular to the central axis, the second major diameter being positioned between the first end and the second end of the shaft portion, and the first major diameter being substantially equal to the second major diameter.
17. The bone screw of claim 15, wherein the thread form includes a third major diameter relative to the central axis in a direction perpendicular to the central axis, the third major diameter being positioned adjacent the second end of the shaft portion, the first major diameter and the second major diameter each being larger than the third major diameter.
18. The bone screw of claim 10 wherein said head comprises a tool engagement recess and said bone screw is insertable into bone via said tool engagement recess via a rotational force applied to the recess.
19. A bone screw, comprising:
a trailing end, an opposite leading end, and a central axis extending through the trailing end and the leading end;
a head extending from the trailing end toward the leading end;
a neck attached to the head and extending from the head toward the front end; and
a shaft attached to and extending from the neck to the leading end, the shaft comprising a first end attached to the neck, an opposing second end juxtaposed with the leading end, and a shank extending around the shank between the first end and the second end, a helical thread form continuous around the shank and having a variable height relative to the central axis in a direction perpendicular to the central axis;
Wherein the thread form terminates at a thread termination surface adjacent the first end of the shaft portion, wherein the thread termination surface abruptly transitions into the shank within less than one-half turn of the shaft portion, and wherein the thread form comprises a face facing the head and at least a portion of the face is oriented at approximately 90 ° to the central axis of the bone screw.
20. The bone screw of claim 19 wherein said thread stop surface comprises a substantially flat first surface portion and a substantially curved second surface portion, said first surface portion extending from a first major diameter to said second surface portion, and said second surface portion transitioning to said shank, said first surface portion and said second surface portion.
Technical Field
The present technology relates generally to thread forms for bone screws.
Background
Conventional thread forms used on conventional bone screws typically include angled faces to facilitate thread termination. These angled surfaces are provided on the thread form adjacent the trailing end of a conventional bone screw. The closer the angled face is to 90 degrees from the central axis of a conventional bone screw, the more turns of the thread form are possible. However, there is at least one significant tradeoff to modifying the angled faces in such a manner. The angled face is thinner closer to the neck of the bone screw as the angled face approaches the central axis by 90 °, and the thread form is thinner as it spirals downward from the angled face toward the neck. Accordingly, there is a need for a thread form that limits portions of the thread form from inadvertently thinning while also serving to maximize the number of turns of the thread form.
Disclosure of Invention
The disclosed technology relates generally to thread forms for bone screws incorporating thread stop surfaces.
In one aspect, the present disclosure provides a bone screw including a trailing end, an opposite leading end, and a central axis extending through the trailing end and the leading end; a head extending from a trailing end toward a leading end; a neck attached to the head and extending from the head towards the front end; and a shaft attached to and extending from the neck to a leading end, the shaft comprising a first end attached to the neck, an opposing second end juxtaposed with the leading end, a helical thread form, and a shank, the helical thread form extending around the shank between the first and second ends; and wherein the thread form terminates at a thread termination surface adjacent the first end of the shaft portion, wherein the thread termination surface abruptly transitions into the shank within less than half a turn of the shaft portion.
In another aspect, the present disclosure provides a bone screw including a trailing end, an opposite leading end, and a central axis extending through the trailing end and the leading end; a head extending from a trailing end toward a leading end; a neck attached to the head and extending from the head towards the front end; and a shaft attached to and extending from the neck to a front end, the shaft comprising a first end attached to the neck, an opposing second end juxtaposed with the front end, a helical thread form extending around the shank between the first end and the second end, and a shank, the helical thread being continuous around the shank and having a variable height relative to the central axis in a direction perpendicular to the central axis; wherein the thread form terminates at a thread terminating surface adjacent the first end of the shaft portion, and wherein the thread terminating surface abruptly transitions into the shank within less than one-half turn of the shaft portion.
In yet another aspect, the present disclosure provides a bone screw including a trailing end, an opposite leading end, and a central axis extending through the trailing end and the leading end; a head extending from a trailing end toward a leading end; a neck attached to the head and extending from the head towards the front end; and a shaft attached to and extending from the neck to a front end, the shaft comprising a first end attached to the neck, an opposing second end juxtaposed with the front end, a helical thread form extending around the shank between the first end and the second end, and a shank, the helical thread being continuous around the shank and having a variable height relative to the central axis in a direction perpendicular to the central axis; wherein the thread form terminates at a thread termination surface adjacent the first end of the shaft portion, wherein the thread termination surface abruptly transitions into the shank within less than one-half turn of the shaft portion, and wherein the thread form includes a face facing the head, and at least a portion of the face is oriented at about 90 ° to a central axis of the bone screw.
The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims.
Drawings
FIG. 1 is a side view illustrating a bone screw of the prior art;
fig. 2 is a side view illustrating a blank for forming the prior art bone screw of fig. 1.
FIG. 3 is a side perspective view illustrating a blank used in an embodiment of manufacturing a bone screw;
FIG. 4 is a side perspective view illustrating a modified blank for use in an embodiment of manufacturing a bone screw;
FIG. 5 is a side cross-sectional view of the modified blank of FIG. 4;
FIG. 6 is a side perspective view illustrating an embodiment of a bone made using the blank of FIG. 3 and the modified blank of FIG. 4;
FIG. 7 is a side view of a receiver received on the bone screw of FIG. 6;
FIG. 8 is an enlarged side view of FIG. 7; and
fig. 9 is a top plan view of the bone screw and receiver of fig. 7 positioned relative to a vertebra of a patient.
Detailed Description
A prior art bone screw 10 that can be used as a cervical lateral mass screw is depicted in fig. 1. The bone screw 10 is used to penetrate tissue, such as bone, and may be used in association with a receiver R (fig. 7-9). For example, receiver R may be the receiver disclosed in U.S. serial No. 15/843,938, which is incorporated herein by reference in its entirety.
As depicted in fig. 1, the bone screw 10 includes a
The bone screw 10 is formed from a blank 30 depicted in fig. 2. The blank 30 includes a head portion 32, a neck portion 34, and a
The
Thread form 26 is formed by the manufacturing process applied to
Thus, the variable major diameter of thread form 26 relative to central axis a1 increases along
As depicted in fig. 2, the angled face 52 (formed by a portion of the first portion 44) is at an angle X of approximately 67 ° from the central axis a 1. The closer the portion of
A bone screw according to an embodiment of the present disclosure is indicated generally by the
Unlike the bone screw 10, the
As discussed above, the manufacturing process may be applied to the blank 62 (fig. 3) to form a modified blank 64 (fig. 4 and 5), and the
The body portion 106 includes a first end 110 adjacent the neck 104 and a second end 112 corresponding to the front end 82 of the
The modified blank 64 may be formed by a manufacturing process applied to the blank 62. Similar to blank 62, modified blank 64 includes a head portion 102, a neck portion 104, a body portion 106, and a central axis a 3. To form the modified blank 64, a portion of the body portion 106 of the blank 62 may be removed in the manufacturing process to form the cavity 130. For example, a cutting and/or grinding process may be used to remove material from the blank 62 to form the cavity 130 of the blank 64. The cavity 130 includes a surface 132, and the first and
As discussed above,
As discussed above, the abrupt transition provided by
As depicted in fig. 7-9, receiver R may be received on head 72 and
Various combinations of bone screws 60 and receivers R may be similarly positioned along the spinal column, and an instrument such as a surgical rod (not shown) may be attached to an adjacent receiver R of the combination of bone screws 60 and receivers R to facilitate correction of spinal abnormalities. The pivotal and rotational movement of the receiver R relative to the head 72 allows the receiver R to be adjusted to accommodate the placement of the surgical rod. Further, the extent of the pivotal movement is increased by using the
It should be understood that the various aspects disclosed herein may be combined in different combinations than those specifically presented in the description and drawings. It will also be understood that, depending on the example, some acts or events in any of the processes or methods described herein can be performed in a different order, may be added, merged, or left out entirely (e.g., not all described acts or events are necessary to implement the described techniques). Additionally, although certain aspects of the disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of the disclosure may be performed by a combination of units or modules associated with, for example, a medical device.
- 上一篇:一种医用注射器针头装配设备
- 下一篇:外科手术器械和方法