Medical screw for bone holding

Abstract

The utility model discloses a medical screw for bone holding, which comprises an anti-rotation pressurizing screw and a lag screw, and the anti-rotation pressurizing screw and the lag screw are respectively provided with thread structures which are mutually twisted; the thread structure of the head of the anti-rotation pressurizing nail is a bone thread, and the thread structure of the tail of the anti-rotation pressurizing nail is a trapezoidal thick thread. According to the scheme, the thread structure of the head of the anti-rotation pressurizing nail is changed into the bone thread with the sharp periphery from a trapezoidal thick thread with a trapezoidal section, so that when the anti-rotation pressurizing nail is screwed into a fixing hole in a bone, the anti-rotation pressurizing nail can automatically drill into the bone of a human body through the bone thread, and certain holding force is exerted on the bone. Meanwhile, the lag screw is twisted with the threads on the surface of the anti-rotation pressurizing nail through the threads on the surface of the lag screw, and the lag screw can move in the axial direction of the anti-rotation pressurizing nail when screwed. The anti-rotation pressurizing nail in the scheme is simple to improve and high in practicability, and can be popularized and used on a large scale under the condition that extra medical cost is not increased.

Description

Technical Field

[0001] The utility model belongs to the field of medical technology, and in particular relates to a medical screw used for bone gripping. Background Art

[0002] When treating fractures, screws are often needed to assist in fixing the fracture site. Figure 1 It is a double-nail threaded twisted design, with two nails combined together and a non-circular cross-section, which can prevent the axis of rotation between the femoral head and the tension screw to maintain a stable fracture site.

[0003] For example, in the patent with publication number CN201668489U, two screws include an anti-rotation compression nail and a tension screw, which can be twisted together and interact with each other through the thread structure on their surfaces. Figure 3 as shown in . Figure 2 The fixing steel plate is provided with a stepped hole for installing screws, and the tail of the anti-rotation compression nail has a cylindrical surface without threads. When the cylindrical surface fits in the stepped hole, continuing to screw can drive the tension screw to move axially toward the head of the anti-rotation compression nail, thereby exerting pressure between the broken bones.

[0004] As mentioned above, the anti-rotation compression nail only plays an anti-rotation and compression role, and the thread on the anti-rotation compression nail is a trapezoidal thick thread, which is not suitable for holding the cancellous bone in the sacral neck. When facing elderly patients with osteoporosis, only the tension screw can hold the bone, and the holding force is weak. Utility Model Content

[0005] In order to solve the technical problem that the anti-rotation compression nail in the background technology cannot hold the bone, the purpose of the utility model is to provide a medical screw for bone holding, which can solve the above problem.

[0006] The technical solution to achieve the purpose of the utility model is: a medical screw for bone gripping, comprising an anti-rotation pressure nail and a tension screw, the anti-rotation pressure nail and the tension screw respectively having mutually twisted thread structures; the head thread structure of the anti-rotation pressure nail is a bone thread, and the tail thread structure of the anti-rotation pressure nail is a trapezoidal thick thread.

[0007] In this solution, the thread structure of the head of the anti-rotation compression nail is changed from a trapezoidal thick thread with a trapezoidal cross section to a bone thread with a sharp outer periphery, so that when the anti-rotation compression nail is screwed into the fixing hole in the bone, it can rely on the bone thread to drill into the human bone by itself, so that it has a certain holding force on the bone. At the same time, the tension screw relies on the thread on its surface to be twisted with the thread on the surface of the anti-rotation compression nail, and screwing the tension screw can also move axially along the anti-rotation compression nail. In addition, the anti-rotation compression nail in this solution is simple to improve and has strong practicality, and can be promoted and used on a large scale without increasing additional medical costs.

[0008] Furthermore, the middle part of the anti-rotation pressurizing nail has a vacant section, and there is no thread structure at the position of the vacant section, so it is convenient to process the threads at both ends of the vacant section.

[0009] Furthermore, the bone thread on the anti-rotation compression nail and the trapezoidal thick thread are located on the same spiral line, which is not only easy to process, but also the thread structure on the tension screw is continuous and can be smoothly twisted with the thread structure on the anti-rotation compression nail, facilitating the forward and backward movement of the tension screw after being twisted.

[0010] Furthermore, the tails of the anti-rotation pressure nail and the tension screw are provided with threaded holes, so as to facilitate the use of other tools for screwing at a later time.

[0011] Furthermore, during conventional installation, it is necessary to use a bottom hole drill to first open the installation hole in the bone, and then install the medical screw, and the cross-sectional diameter of the bottom hole drill is the same as the cross-sectional diameter of the anti-rotation pressure nail (i.e., the distance between the threaded tooth tops at both ends of the cross section of the anti-rotation pressure nail). The bottom hole drill in this solution is a step drill, that is, the cross-sectional diameter of the front half of the bottom hole drill is smaller than the cross-sectional diameter of the rear half, and the cross-sectional size of the front half of the bottom hole drill is smaller than the cross-sectional diameter of the anti-rotation pressure nail (i.e., the distance between the threaded tooth tops at both ends of the cross section of the anti-rotation pressure nail). In this way, the installation hole is preset, which is convenient for the rapid installation of the medical screw, and the bone thread of the head of the anti-rotation pressure nail can be screwed into the bone in the human bone by relying on its own characteristics, thereby increasing the holding force of the anti-rotation pressure nail on the bone.

[0012] By adopting the above technical solution, the utility model has the following beneficial effects:

[0013] (1) The traditional anti-rotation compression nail head trapezoidal thick thread is changed to bone thread, which can be screwed into the bone to increase the holding force on the bone;

[0014] (2) A vacant section is provided in the middle of the anti-rotation compression nail to facilitate the processing of the trapezoidal thick threads and bone threads on both sides thereof;

[0015] (3) The thread structures at the front and rear ends of the anti-rotation compression nail are located on the same spiral line and do not affect the axial movement of the tension screw. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the content of the utility model easier to understand, the utility model is further described in detail according to specific embodiments and in conjunction with the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the utility model of using a Chinese medicine screw to fix a steel plate to a bone fracture site;

[0018] Figure 2 It is a schematic diagram of the steel plate in the utility model;

[0019] Figure 3 This is a schematic diagram of the structure of a traditional medical screw in the utility model;

[0020] Figure 4 This is a schematic diagram of the structure of a traditional anti-rotation pressure nail in the utility model;

[0021] Figure 5 This is a schematic diagram of the structure of the improved anti-rotation pressure nail in the utility model;

[0022] Figure 6 This is a schematic diagram of the improved medical screw structure in the utility model;

[0023] Figure 7 This is a schematic diagram of the bottom hole drill in the utility model;

[0024] Figure 8 This is a schematic diagram of the bottom hole drill in the utility model being improved into a step drill.

[0025] The numbers in the attached drawings are: 1 anti-rotation compression nail; 2 tension screw; 3 steel plate; 4 bone thread; 5 trapezoidal thick thread; 6 vacant segment; 7 threaded hole; 8 bottom hole drill; 9 step drill; 10 bone. DETAILED DESCRIPTION

[0026] Example:

[0027] like Figure 4-Figure 7As shown, this embodiment provides a medical screw for bone gripping, including an anti-rotation pressure nail 1 and a tension screw 2, wherein the anti-rotation pressure nail 1 and the tension screw 2 respectively have mutually twisted thread structures; the head thread structure of the anti-rotation pressure nail 1 is a bone thread 4, and the tail thread structure of the anti-rotation pressure nail 1 is a trapezoidal thick thread 5. In this scheme, the thread structure of the head of the anti-rotation pressure nail 1 is changed from a trapezoidal thick thread 5 with a trapezoidal cross section to a bone thread 4 with a sharp periphery, so that when the anti-rotation pressure nail 1 is screwed into the fixing hole in the bone 10, it can rely on the bone thread 4 to drill into the human bone 10 by itself, so that it has a certain gripping force on the bone 10. At the same time, the tension screw 2 relies on the thread on its surface to be twisted with the surface thread of the anti-rotation pressure nail 1, and the tension screw 2 can also be axially moved along the anti-rotation pressure nail 1 when it is screwed. In addition, the anti-rotation pressure nail 1 in this scheme is simple to improve and has strong practicality, and can be promoted and used on a large scale without increasing additional medical costs.

[0028] Preferably, the middle portion of the anti-rotation pressurized nail 1 has a vacant section 6 , and there is no thread structure at the position of the vacant section 6 , so that it is convenient to process the threads at both ends of the vacant section 6 .

[0029] Preferably, the bone thread 4 and the trapezoidal thick thread 5 on the anti-rotation compression nail 1 are located on the same spiral line, which is not only convenient for processing, but also the thread structure on the tension screw 2 is continuous and can be smoothly twisted with the thread structure on the anti-rotation compression nail 1, facilitating the forward and backward movement of the tension screw 2 after being screwed.

[0030] Preferably, the tails of the anti-rotation pressure nail 1 and the tension screw 2 have threaded holes 7 to facilitate screwing with other tools later.

[0031] like Figure 8 As shown, during conventional installation, it is necessary to use a bottom hole drill 8 to first open a mounting hole in the bone 10, and then install the medical screw, and the cross-sectional diameter of the bottom hole drill 8 is the same as the cross-sectional diameter of the anti-rotation pressure nail 1 (i.e., the distance between the thread tops at both ends of the cross section of the anti-rotation pressure nail 1). The bottom hole drill 8 in this solution is a step drill 9, that is, the cross-sectional diameter of the front half of the bottom hole drill 8 is smaller than the cross-sectional diameter of the rear half, and the cross-sectional size of the front half of the bottom hole drill 8 is smaller than the cross-sectional diameter of the anti-rotation pressure nail 1 (i.e., the distance between the thread tops at both ends of the cross section of the anti-rotation pressure nail 1). In this way, the mounting hole is preset, which is convenient for the rapid installation of the medical screw, and the bone thread 4 at the head of the anti-rotation pressure nail 1 can be screwed into the bone 10 by relying on its own characteristics, thereby increasing the holding force of the anti-rotation pressure nail 1 on the bone 10.

[0032] Working principle: When in use, first use the step drill 9 to open a mounting hole in the bone 10, then the head of the anti-rotation compression nail 1 continues to be screwed into the bone 10 in the mounting hole by relying on its own bone thread 4, and then the tension bolt is screwed and installed in place.

[0033] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A medical screw for bone gripping, characterized in that: The invention comprises an anti-rotation pressure nail (1) and a tension screw (2), wherein the anti-rotation pressure nail (1) and the tension screw (2) respectively have mutually twisted thread structures; the head thread structure of the anti-rotation pressure nail (1) is a bone thread (4), and the tail thread structure of the anti-rotation pressure nail (1) is a trapezoidal thick thread (5).

2. A medical screw for bone gripping according to claim 1, characterized in that: The middle part of the anti-rotation pressure nail (1) has a vacant section (6), and there is no thread structure at the position of the vacant section (6).

3. A medical screw for bone gripping according to claim 2, characterized in that: The bone thread (4) and the trapezoidal thick thread (5) on the anti-rotation compression nail (1) are located on the same spiral line.

4. The medical screw for bone gripping according to claim 1, characterized in that: The tails of the anti-rotation pressure nail (1) and the tension screw (2) are provided with threaded holes (7).

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