Internal fixation device

Abstract

The present invention provides an internal fixation device, wherein the internal fixation device comprises: a main nail, a limiting mechanism and a connecting cross bar; the main nail comprises a nail tail and a nail rod, the nail tail and the nail rod are integrally formed, a U-shaped groove is provided at one end of the nail tail away from the nail rod, the connecting cross bar is placed in the U-shaped groove, the connecting cross bar is engaged and connected with the nail tail, and the limiting mechanism is slidably connected with the nail tail; the limiting mechanism is used to limit the connecting cross bar in the U-shaped groove. The present invention solves the problem that the internal fixation frame in the prior art has a large irritation to the patient's muscles and skin. The internal fixation device recorded in the present invention, since the nail tail of the main nail does not need to be provided with a thread, the length of the U-shaped groove of the nail tail is slightly longer than the diameter of the connecting cross bar, so that the limiting mechanism can be close to the connecting cross bar, reducing the length of the nail tail, thereby reducing the irritation to the patient's muscles and skin, and can also reduce the patient's discomfort after surgery.

Description

Technical Field

[0001] The present invention relates to the technical field of orthopedic medical instruments, and in particular to an internal fixation device. Background Art

[0002] Minimally invasive anterior pelvic ring internal fixator (MINI) is currently used clinically for brittle anterior pelvic ring injuries in the elderly. The most widely used and effective device in this procedure is called an internal fixator (INFIX). The original intention of the internal fixator is to stabilize the anterior pelvic ring, so anterior pelvic ring injuries, including symphysis pubis separation and pubic ramus fracture, are its best indications. Because the internal fixator is located in the front of the lower abdomen and pelvis, thin patients will experience subjective discomfort, especially for those in a sitting position. Subjective discomfort usually occurs after surgery and affects daily life, but the discomfort disappears after the internal fixator is removed.

[0003] At present, the traditional internal fixator uses an internal screw to press the connecting cross bar between the internal screw and the main nail, so an internal thread is set at the tail of the main nail, which makes the length of the side wall of the tail of the main nail relatively long, causing greater stimulation to the patient's muscles and skin.

[0004] With regard to the problem that the internal fixator in the prior art has a significant irritation to the patient's muscles and skin, no effective solution has been proposed. Summary of the invention

[0005] In view of this, the present invention provides an internal fixation device to solve the problem that the internal fixation frame in the prior art causes great irritation to the patient's muscles and skin.

[0006] To this end, the present invention provides the following technical solution: comprising: a main nail, a limiting mechanism and a connecting cross bar;

[0007] The main nail includes a nail tail portion and a nail rod portion, the nail tail portion and the nail rod portion are integrally formed, a U-shaped groove is provided at one end of the nail tail portion away from the nail rod portion, the connecting cross bar is placed in the U-shaped groove, the connecting cross bar is bite-engaged with the nail tail portion, and the limiting mechanism is slidably connected to the nail tail portion; the limiting mechanism is used to limit the connecting cross bar within the U-shaped groove.

[0008] Optionally, a first engaging tooth is provided at the bottom of the U-shaped groove, and a second engaging tooth matching the first engaging tooth is provided on the connecting cross bar, and the first engaging tooth and the second engaging tooth are engaged with each other.

[0009] Optionally, the limiting mechanism is in an inverted U-shape, including a limiting portion and a supporting portion, two supporting portions are respectively arranged on both sides of the limiting portion, the limiting portion and the supporting portion are integrally formed, and the limiting mechanism is slidably connected to the nail tail portion through a slider and a sliding groove matching the slider; the slider is arranged on one of the inner walls of the two supporting portions and the outer walls of the U-shaped groove, and the sliding groove is arranged on the other of the inner walls of the two supporting portions and the outer walls of the U-shaped groove.

[0010] Optionally, the internal fixation device further comprises an internal screw;

[0011] The limiting portion is provided with a screw hole, the screw hole passes through the limiting portion, the inner screw is fixedly connected to the limiting mechanism through the screw hole, and the connecting cross bar is pressed between the limiting mechanism and the nail tail.

[0012] Optionally, the thread on the nail shaft portion includes a coarse thread and a fine thread, the coarse thread is close to the nail tail portion, and the fine thread is far away from the nail tail portion.

[0013] Optionally, the connecting cross bar includes an elastic portion and a rigid portion, and the elastic portion and the rigid portion are alternately connected.

[0014] Optionally, the elastic part is a spring, and two ends of the spring are respectively fixedly connected to the rigid part.

[0015] The technical solution of the present invention has the following advantages:

[0016] The present invention provides an internal fixation device, which solves the problem of the existing internal fixation frame causing great irritation to the patient's muscles and skin. In the internal fixation device described in the present invention, since the nail tail of the main nail does not need to be provided with a thread, the length of the U-shaped groove at the nail tail can be slightly longer than the diameter of the connecting cross bar, so that the limiting mechanism can be close to the connecting cross bar, reducing the length of the nail tail, thereby reducing the irritation to the patient's muscles and skin. At the same time, in the early stage of the patient's placement of the internal fixation device, the main nail can be retained at the pelvic fracture site, and the other parts can be removed from the patient's body, thereby reducing the patient's postoperative discomfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 is a schematic structural diagram of an internal fixation device according to the present invention;

[0019] Figure 2 is a schematic structural diagram of a main nail according to the present invention;

[0020] Figure 3 is a cross-sectional view of the internal fixing device according to the present invention along the length direction of the connecting cross bar;

[0021] Figure 4 is a schematic structural diagram of a limiting mechanism according to the present invention;

[0022] Figure 5 is a schematic structural diagram of an inner screw according to the present invention;

[0023] Figure 6 2 is a schematic structural diagram of a connecting cross bar according to the present invention.

[0024] In the figure,

[0025] 1. Main nail; 11. Nail tail; 111. U-shaped groove; 112. First meshing tooth; 113. Slide groove; 12. Nail rod; 121. Coarse thread; 122. Fine thread; 2. Limiting mechanism; 21. Limiting part; 211. Screw hole; 22. Support part; 221. Sliding block; 3. Connecting cross bar; 31. Second meshing tooth; 32. Elastic part; 33. Rigid part; 4. Inner screw. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0028] In the present invention, the word "exemplary" is used to mean "used as an example, illustration or description". Any embodiment described as "exemplary" in the present invention is not necessarily to be construed as being preferred or advantageous over other embodiments. The following description is given to enable any technician in the field to implement and use the present invention. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present invention can be implemented without using these specific details. In other instances, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present invention with unnecessary details. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present invention.

[0029] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] The present invention provides an internal fixation device which can be used for postoperative fixation of pelvic injuries, such as postoperative fixation of symphysis pubis separation and postoperative fixation of pubic ramus fracture, as well as spinal injuries. Figure 1 is a schematic diagram of the structure of the internal fixation device according to the present invention, such as Figure 1 As shown, the internal fixation device comprises: a main nail 1, a limiting mechanism 2 and a connecting cross bar 3. Specifically, the connecting cross bar 3 is limited between the main nail 1 and the limiting mechanism 2 by the limiting mechanism 2, wherein a plurality of detachable screws consisting of the main nail 1 and the limiting mechanism 2 can be connected to the connecting cross bar 3 to form an internal fixation device, which is placed in the patient's pelvic or spinal fracture site to effectively fix the fracture site. In addition, the main nail 1 is a low-profile screw, and after the internal fixation device is placed in the patient's fracture site, the main nail 1 and the limiting mechanism 2 can reduce the stimulation to the patient's muscles and skin at the fracture site.

[0031] like Figure 2As shown, the main nail 1 includes a nail tail 11 and a nail rod 12. The nail tail 11 and the nail rod 12 are integrally formed. A U-shaped groove 111 is provided at one end of the nail tail 11 away from the nail rod 12. The connecting cross bar 3 is placed in the U-shaped groove 111. The connecting cross bar 3 is engaged with the nail tail 11. The limiting mechanism 2 is slidably connected with the nail tail 11. The limiting mechanism 2 is used to limit the connecting cross bar 3 in the U-shaped groove 111. Specifically, the length of the side wall of the U-shaped groove is slightly larger than the diameter of the connecting cross bar. After the connecting cross bar 3 is placed on the nail tails 11 of multiple main nails 1, it is engaged with the multiple nail tails 11, so that the connecting cross bar 3 cannot move along the length direction of the connecting cross bar 3. Then, the connecting cross bar 3 is pressed into the U-shaped groove 111 of the nail tail 11 by the limiting mechanism 2 to prevent the connecting cross bar 3 from escaping from the U-shaped groove 111, thereby forming an internal fixing device. After the internal fixation device is placed in the fracture site of the patient, the limiting mechanism 2 and the connecting cross bar 3 can be removed while retaining the main nail 1, thereby reducing the patient's discomfort without affecting the patient's recovery.

[0032] In the prior art, the connecting crossbar is usually limited between the main nail and the inner screw by the main nail and the inner screw. At the same time, because the inner screw needs to be screwed into the tail of the main nail, the length of the side wall of the U-shaped groove of the tail of the main nail must be greater than the sum of the diameter of the connecting crossbar and the thickness of the inner screw, which leads to a relatively long tail of the main nail. After the main nail is inserted into the patient, it will irritate the patient's muscles and skin. In the present application, the main nail 1 can be a low-profile screw, that is, the length of the side wall of the U-shaped groove of the tail of the main nail is slightly greater than the diameter of the connecting crossbar, and then the limiting mechanism 2 is slidably connected to the tail 11 of the main nail 1, so that the height of the tail 11 is relatively low, which reduces the irritation to the muscles and skin after being inserted into the fracture of the patient. At the same time, the limiting mechanism 2 and the main nail 1 are slidably connected, which is convenient for removing the connecting cross bar 3 and the limiting mechanism 2 after surgery, and retaining the main nail 1 at the patient's fracture site. Since the nail tail 11 of the main nail 1 is relatively short, the nail tail 11 has less stimulation to the patient's muscles and skin, thereby solving the problem of the internal fixation frame in the prior art causing greater stimulation to the patient's muscles and skin.

[0033] In some optional embodiments, such as Figure 3As shown, the bottom of the U-shaped groove 111 is provided with a first engaging tooth 112, and the connecting crossbar 3 is provided with a second engaging tooth 31 matching the first engaging tooth 112, and the first engaging tooth 112 and the second engaging tooth 31 are engaged with each other. Specifically, a plurality of continuous rectangular grooves arranged along the length direction of the U-shaped groove 111 are provided at the bottom of the U-shaped groove 111, as the first engaging tooth 112; and a plurality of protrusions that can engage with the first engaging tooth 112 are provided at positions corresponding to the first engaging teeth 112 on the connecting crossbar 3, as the second engaging teeth 31. The first engaging teeth 112 and the second engaging teeth 31 are engaged with each other, so that the connecting crossbar 3 is difficult to move along the length direction of the connecting crossbar 3, and the connecting crossbar 3 is prevented from being separated from the nail tail 11 along the length direction of the connecting crossbar 3. In addition, the first meshing tooth 112 can also be a sawtooth groove, the second meshing tooth 31 can also be a sawtooth protrusion, and the first meshing tooth 112 and the second meshing tooth 31 can mesh with each other. Those skilled in the art should know that the shape and position of the first meshing tooth 112 and the second meshing tooth 31 are not used to limit the present invention, and other shapes and positions are also within the protection scope of the present invention. For example, the first meshing tooth 112 can be a triangular or cylindrical groove, and the second meshing tooth 31 can be a triangular or cylindrical protrusion, etc.; the first meshing tooth 112 can also be set on the side walls on both sides of the U-shaped groove 111, and the second meshing tooth 31 is set at the corresponding position of the connecting cross bar 3.

[0034] To illustrate the limiting mechanism 2, in some optional embodiments, such as Figure 4As shown, the limiting mechanism 2 is in an inverted U shape, including a limiting portion 21 and a supporting portion 22, two supporting portions 22 are respectively arranged on both sides of the limiting portion 21, the limiting portion 21 and the supporting portion 22 are integrally formed, and the limiting mechanism 2 is slidably connected with the nail tail portion 11 through a slider 221 and a slide groove 113 matching the slider 221; the slider 221 is arranged on one of the inner walls of the two supporting portions 22 and the outer wall of the U-shaped groove 111, and the slide groove 113 is arranged on the other of the inner walls of the two supporting portions 22 and the outer wall of the U-shaped groove 111. That is, the slide groove 113 is arranged on the outer wall of the U-shaped groove 111 along the length direction of the U-shaped groove 111, and the sliders 221 matching the slide groove 113 are arranged on the inner walls of the two supporting portions 22; or, the slide groove 113 is arranged on the inner walls of the two supporting portions 22 along the length direction of the U-shaped groove 111, and the sliders 221 matching the slide groove 113 are arranged on the outer wall of the U-shaped groove 111. Specifically, the connecting cross bar 3 is placed in the U-shaped groove 111 of the nail tail 11, and the slider 221 on the limiting mechanism 2 slides into the slide groove 113 on the nail tail 11. The limiting portion 21 on the limiting mechanism 2 covers the notch of the U-shaped groove 111 and presses the connecting cross bar 3, so that the connecting cross bar 3 is difficult to be separated from the nail tail 11 along the length direction of the main nail 1. At the same time, through the action of the slide groove 113 and the slider 221, the limiting mechanism 2 and the main nail 1 are easy to disassemble, and the length of the nail tail 11 is reduced, reducing the stimulation of the internal fixation device on the patient's muscles and skin, and at the same time facilitating the disassembly of the internal fixation device after surgery. In addition, in this embodiment, the slider 221 can be cylindrical, and the slide groove 113 can be a cylindrical groove matching the slider 221. Those skilled in the art should know that the shapes of the slider 221 and the slide groove 113 are not used to limit the present invention, and other types of slider 221 shapes are also within the protection scope of the present invention. For example, the slider 221 can also be a rectangular block, and the slide groove 113 can be a rectangular groove matching the slider 221.

[0035] To illustrate the inner screw 4, in some optional embodiments, as Figure 5 As shown, the internal fixing device also includes an internal screw 4; Figure 4 As shown, the limiting portion 21 is provided with a screw hole 211, which penetrates the limiting portion 21, and the inner screw 4 is fixedly connected to the limiting mechanism 2 through the screw hole 211, and the connecting cross bar 3 is pressed between the limiting mechanism 2 and the nail tail 11. The height of the inner screw 4 does not exceed the thickness of the limiting portion 21. The connecting cross bar 3 is further pressed by the inner screw 4, which can prevent the connecting cross bar 3 from sliding out of the nail tail 11. When only the main nail 1 is retained in the internal fixation device and the rest is taken out, the inner screw 4 is taken out from the screw hole 211, slides out of the limiting mechanism 2, and finally takes out the connecting cross bar 3, reducing the patient's discomfort.

[0036] To illustrate the threads on the nail shank 12, in some optional embodiments, the threads on the nail shank 12 include coarse threads 121 and fine threads 122, the coarse threads 121 are close to the nail tail 11, and the fine threads 122 are far away from the nail tail 11. Specifically, the coarse threads 121 have high strength and good fixing performance; the fine threads 122 have good sealing performance. Under the premise of not taking anti-loosening measures, the anti-loosening performance of the fine threads 122 is better than that of the coarse threads 121, but the strength of the fine threads 122 is low. Therefore, setting the threads on the nail shank 12 as coarse threads 121 and fine threads 122 can effectively enhance the holding force of the main nail 1.

[0037] To illustrate the connecting crossbar 3, in some optional embodiments, such as Figure 6 As shown, the connecting crossbar 3 includes an elastic portion 32 and a rigid portion 33, and the elastic portion 32 and the rigid portion 33 are alternately connected. Specifically, when multiple main nails 1 are connected through the connecting crossbar 3, the main nails 1 are detachably connected to the rigid portion 33 of the connecting crossbar 3. At the same time, the connecting crossbar 3 can be bent by the action of the elastic portion 32 between the two rigid portions 33, and then when the internal fixation device is inserted, the connecting crossbar 3 can be bent by the action of the elastic portion 32, and then the main nails 1 can be nailed into the appropriate position, which can play a better fixing role on the fracture. At the same time, the second engaging teeth 31 can be set on the rigid portion 33.

[0038] To further illustrate the connecting cross bar 3, in some optional embodiments, the elastic portion 32 is a spring, and the two ends of the spring are respectively fixedly connected to the rigid portion 33. The connecting cross bar 3 can be bent by the action of the spring, which facilitates the internal fixation device to fix the fracture. Those skilled in the art should know that the elastic portion 32 being a spring is not used to limit the present invention, and the elastic portion 32 composed of other structures or materials is also within the scope of protection of the present invention, such as a silicone rod and a rod-shaped structure formed by a metal mesh.

[0039] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An internal fixation device, characterized in that: include: A main nail (1), a limiting mechanism (2) and a connecting cross bar (3); The main nail (1) comprises a nail tail portion (11) and a nail rod portion (12); the nail tail portion (11) and the nail rod portion (12) are integrally formed; an end of the nail tail portion (11) away from the nail rod portion (12) is provided with a U-shaped groove (111); the connecting cross bar (3) is placed in the U-shaped groove (111); the connecting cross bar (3) is engaged with the nail tail portion (11); the limiting mechanism (2) is slidably connected to the nail tail portion (11); the limiting mechanism (2) is used to limit the connecting cross bar (3) in the U-shaped groove (111); The limiting mechanism (2) is in an inverted U-shape, comprising a limiting portion (21) and a supporting portion (22), the two supporting portions (22) being respectively arranged on both sides of the limiting portion (21), the limiting portion (21) and the supporting portion (22) being integrally formed, the limiting mechanism (2) being slidably connected to the nail tail portion (11) via a slider (221) and a slide groove (113) matching the slider (221); the slider (221) being arranged on one of the inner walls of the two supporting portions (22) and the outer wall of the U-shaped groove (111), the slide groove (113) being arranged on the other of the inner walls of the two supporting portions (22) and the outer wall of the U-shaped groove (111), Also includes an inner screw (4); The limiting portion (21) is provided with a screw hole (211), the screw hole (211) passes through the limiting portion (21), and the inner screw (4) is fixedly connected to the limiting mechanism (2) through the screw hole (211), so as to press the connecting cross bar (3) between the limiting mechanism (2) and the nail tail (11).

2. The internal fixation device according to claim 1, characterized in that: A first engaging tooth (112) is arranged at the bottom of the U-shaped groove (111), and a second engaging tooth (31) matching the first engaging tooth (112) is arranged on the connecting cross bar (3), and the first engaging tooth (112) and the second engaging tooth (31) are engaged with each other.

3. The internal fixation device according to claim 1, characterized in that: The threads on the nail shank portion (12) comprise coarse threads (121) and fine threads (122), wherein the coarse threads (121) are close to the nail tail portion (11) and the fine threads (122) are far from the nail tail portion (11).

4. The internal fixation device according to claim 1, characterized in that: The connecting cross bar (3) comprises an elastic portion (32) and a rigid portion (33), and the elastic portion (32) and the rigid portion (33) are alternately connected.

5. The internal fixation device according to claim 4, characterized in that: The elastic part (32) is a spring, and two ends of the spring are respectively fixedly connected to the rigid part (33).

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