Intramedullary fixing device for assisting metacarpal bone fracture healing

Abstract

The utility model provides an intramedullary fixing device for assisting metacarpal bone fracture healing. The intramedullary fixing device comprises a marrow nail body, a fixing piece and a fixing screw. The marrow nail body is provided with a first end part and a second end part, and the second end part is inserted into a metacarpal bone; the fixing piece is fixedly connected with the first end part, and more than one threaded hole is formed in the fixing piece; one end of each fixing screw is fixedly installed in the corresponding threaded hole, the other end of each fixing screw is fixedly installed on the metacarpal bone, and the number of the fixing screws is matched with the number of the threaded holes. According to the intramedullary fixing device for assisting metacarpal bone fracture healing, the medullary nail body can be inserted into the metacarpal bone marrow cavity after being drilled through the metacarpal bone base, the split metacarpal bone is fixed through the fixing screws, then the metacarpal bone is fixed through the three-point supporting principle, the fixing effect is more reliable compared with a kirschner wire, and the metacarpal bone fracture healing effect is better. And the problems of tendon irritation caused by fixation of the incision bone fracture plate and increase of postoperative non-healing risk caused by large-range periosteum stripping are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, in particular to an intramedullary fixation device for assisting the healing of metacarpal fractures. Background Art

[0002] Metacarpal fractures are relatively common among hand fractures, and metacarpal neck fractures are particularly common, especially the fifth metacarpal neck fracture. This situation often occurs when an individual strikes a hard object with force, especially with a high incidence rate among boxers, so it is also named "boxer fracture". Such fractures are likely to cause the metacarpal head to shift towards the palm side. If no timely treatment measures are taken, it may lead to malunion or poor healing of the metacarpal bone. In order to restore the normal anatomical shape of the metacarpal head and promote early metacarpophalangeal joint movement, and prevent the functional disorders caused by joint stiffness, the surgical method of implanting internal fixation devices has been proven to be an effective treatment means.

[0003] Currently, the implantation of internal fixation devices for the treatment of metacarpal fractures mainly includes bone plates and Kirschner wires, but each method has its specific limitations. The application of bone plates often requires a large incision on the dorsal side of the hand to expose and fix the fracture, which not only increases the surgical trauma, but also may cause extensive periosteal stripping during the operation and tendon irritation after the operation. Although Kirschner wires can be used to fix metacarpal neck fractures, multiple Kirschner wires need to be cross-fixed to maintain fracture stability, but its stability is relatively poor, and there is a high risk of fracture displacement after the operation.

[0004] In addition, metacarpal neck fractures accompanied by metacarpal head fractures are not uncommon in clinical treatment. At present, such fractures are mostly treated by combining an external fixator with Kirschner wire fixation. During the treatment process of this method, the patient needs to wear the external fixator for a long time, resulting in limited daily life and work, and unable to perform early functional exercises, increasing the risk of tendon adhesion. Summary of the Utility Model

[0005] In view of this, the purpose of the present utility model is to overcome the deficiencies in the prior art and provide an intramedullary fixation device for assisting the healing of metacarpal fractures.

[0006] The present utility model provides the following technical solutions:

[0007] An embodiment of the present application provides an intramedullary fixation device for assisting the healing of metacarpal fractures, including a medullary nail body, a fixing member, and fixing screws. The medullary nail body has a first end and a second end, and the second end is inserted into the metacarpal bone; the fixing member is fixedly connected to the first end, and a threaded hole is provided on the fixing member, and more than one threaded hole is provided; one end of the fixing screw is fixedly installed in the threaded hole, and the other end of the fixing screw is fixedly installed on the metacarpal bone, and the number of the fixing screws is matched with the number of the threaded holes.

[0008] In one embodiment, the intramedullary nail body is a rod structure with a curvature.

[0009] In one embodiment, the fixing member includes a first fixing portion and a second fixing portion. The second fixing portion is fixedly connected to the first end portion. The first fixing portion fixedly connects the second fixing portion. The threaded hole is formed in the first fixing portion. The first fixing portion is a plate structure. The second fixing portion is a trapezoidal block with a gradually changing outer diameter. The large outer diameter end of the second fixing portion is fixedly connected to the first fixing portion, so that a stepped surface is formed between the second fixing portion and the first fixing portion. The small outer diameter end of the second fixing portion is fixedly connected to the first end portion. The small outer diameter end of the second fixing portion is equal in outer diameter to the first end portion, so that an arc-shaped wall surface is formed between the second fixing portion and the first end portion.

[0010] In one embodiment, the axis of at least one of the threaded holes forms an angle with a first direction, and the first direction is perpendicular to the plane where the first fixing portion is located.

[0011] In one embodiment, a part of the inner wall surface of a part of the threaded holes is located on the stepped surface between the second fixing portion and the first fixing portion.

[0012] In one embodiment, a fillet is provided at one end of the first fixing portion away from the second fixing portion.

[0013] In one embodiment, when two or more threaded holes are provided, the axes of at least two of the threaded holes form an angle.

[0014] In one embodiment, when a plurality of threaded holes are provided, the threaded holes are divided into two groups. The two groups of threaded holes are a first hole group and a second hole group respectively. The first hole group is distributed along a first track, and the second hole group is distributed along a second track. The first track is perpendicular to the second track.

[0015] In one embodiment, the axes of the threaded holes in the second hole group form an angle with each other, and the axes of the threaded holes in the second hole group form an angle with the axes of the threaded holes in the first hole group.

[0016] In one embodiment, the fixing screw has a nail head and a nail body. External threads are provided on the nail head and the nail body. The nail head is in threaded engagement with the threaded hole, and the nail body is in threaded engagement with the metacarpal bone.

[0017] The embodiments of the present invention have the following advantages:

[0018] The intramedullary nail body can be inserted into the metacarpal medullary cavity after drilling through the metacarpal base, and the split metacarpal bones are fixed by fixing screws. Then, the metacarpal bones are fixed based on the three-point support principle, which is more reliable than the Kirschner wire fixation and avoids the problems of tendon irritation caused by open plate fixation and increased risk of nonunion due to extensive periosteal stripping.

[0019] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the following provides preferred embodiments and detailed descriptions in conjunction with the accompanying drawings. Brief Description of the Drawings

[0020] To more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present utility model and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0021] Figure 1 A perspective structural view showing a partial structure of one embodiment of the intramedullary fixation device for assisting metacarpal fracture healing provided by the embodiment of the present application;

[0022] Figure 2 A second perspective structural view showing a partial structure of one embodiment of the intramedullary fixation device for assisting metacarpal fracture healing provided by the embodiment of the present application;

[0023] Figure 3 A third perspective structural view showing a partial structure of one embodiment of the intramedullary fixation device for assisting metacarpal fracture healing provided by the embodiment of the present application;

[0024] Figure 4 A fourth perspective structural view showing a partial structure of one embodiment of the intramedullary fixation device for assisting metacarpal fracture healing provided by the embodiment of the present application;

[0025] Figure 5 A fifth perspective structural view showing the fixing screw of one embodiment of the intramedullary fixation device for assisting metacarpal fracture healing provided by the embodiment of the present application.

[0026] Main Element Symbol Description:

[0027] 100 - intramedullary nail body; 110 - first end; 120 - second end;

[0028] 200 - fixing member; 210 - first fixing portion; 220 - second fixing portion;

[0029] 300 - fixing screw;

[0030] 400 - First hole group; 410 - First trajectory; 450 - Second hole group; 460 - Second trajectory. Detailed implementation manners

[0031] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.

[0032] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. On the contrary, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration.

[0033] In the present utility model, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0034] 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 quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, the meaning of "a plurality" is two or more unless otherwise clearly and specifically defined.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of the template herein are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0036] As Figures 1 to 5As shown in the figure, an embodiment of the present application provides an intramedullary fixation device for assisting in the healing of metacarpal fractures, including a medullary nail body 100, a fixing member 200, and a fixing screw 300.

[0037] As Figure 1 shown, the medullary nail body 100 has a first end 110 and a second end 120, and the second end 120 is inserted into the medullary cavity of the metacarpal bone. The medullary nail body 100 is fixedly arranged in the metacarpal bone through the second end 120, and the second end 120 of the medullary nail body 100 is located in the medullary cavity of the metacarpal bone. In one embodiment, the second end 120 of the medullary nail body 100 penetrates through the medullary cavity of the metacarpal bone and then inserts into the inner wall of the metacarpal bone. In another embodiment, the second end 120 of the medullary nail body 100 penetrates from the medullary cavity of the metacarpal bone through the inner wall of the metacarpal bone to the outside of the metacarpal bone.

[0038] As Figure 1 shown, the fixing member 200 is fixedly connected to the first end 110; exemplarily, the fixing member 200 is fixedly connected to the first end 110 by means of welding, clamping, or integral molding.

[0039] As Figure 2 shown, the fixing member 200 is provided with threaded holes, and the number of threaded holes is more than one; after the metacarpal bone is separated, a metacarpal bone main body and several separated metacarpal bone segments separated from the metacarpal bone main body are formed. As Figure 3 shown, one end of the fixing screw 300 is fixedly installed in the threaded hole, and the other end of the fixing screw 300 is fixedly installed on the separated metacarpal bone segment. The separated metacarpal bone segment is fixedly connected to the metacarpal bone main body through the medullary nail body 100 and the fixing screw 300.

[0040] The number of the fixing screws 300 is matched with the number of the threaded holes.

[0041] As Figure 4 shown, exemplarily, four threaded holes are provided, and four fixing screws 300 are correspondingly provided. In another embodiment, one threaded hole is provided, and one fixing screw 300 is correspondingly provided. In another embodiment, five threaded holes are provided, and five fixing screws 300 are correspondingly provided.

[0042] The medullary nail body 100 can be inserted into the medullary cavity of the metacarpal bone after drilling through the metacarpal bone base, and the separated metacarpal bone segments are fixed by the fixing screws 300. Furthermore, the metacarpal bone is fixed by the three-point support principle, which is more reliable than the Kirschner wire fixation effect, and avoids the problems of tendon irritation caused by open bone plate fixation and the increased risk of nonunion after extensive periosteal stripping.

[0043] In addition, metacarpal neck fractures accompanied by metacarpal head fractures are not uncommon in clinical treatment. Currently, external fixators combined with Kirschner wires are mostly used for the treatment of such fractures. During the treatment process, patients need to wear external fixators for a long time, resulting in limited daily life and work, and unable to perform early functional exercises, increasing the risk of tendon adhesion. The combination of the intramedullary nail body 100 and the fixation screw 300 can achieve better fixation effect, and there is no need for extensive incision, and early functional exercises can be carried out. It is a better surgical option with great clinical promotion value and application prospects.

[0044] The installation and use method of the intramedullary fixation device for assisting metacarpal fracture healing provided by the embodiment of the present application: After reducing the fracture under fluoroscopy during the operation, incise the part to be operated, expose the metacarpal head, drill a hole in the metacarpal bone, maintain the fracture reduction and rotate the intramedullary nail body into the metacarpal medullary cavity from the drilled hole under the monitoring of X-ray fluoroscopy until the intramedullary nail body is firmly fixed in the medullary cavity. For patients with metacarpal head fractures, the fracture reduction is also maintained, and a threaded hole is drilled at the fixing part 200 under the monitoring of X-ray fluoroscopy, and a suitable fixing screw 300 is selected and screwed in for fixation.

[0045] As Figures 1 to 3 shown, in one embodiment, the intramedullary nail body 100 is a rod-shaped structure with a curvature. The intramedullary nail body 100 is set as a curved rod-shaped structure with a curvature, which can prevent the intramedullary nail body 100 from slipping out of the metacarpal medullary cavity.

[0046] As Figure 2 shown, in one embodiment, the fixing part 200 includes a first fixing part 210 and a second fixing part 220.

[0047] The second fixing part 220 is fixedly connected to the first end part 110 by welding, integral molding, clamping or bolt connection.

[0048] The first fixing part 210 is fixedly connected to the second fixing part 220 by welding, integral molding, clamping or bolt connection.

[0049] As Figure 2 shown, the first fixing part 210 is a plate-shaped structure, and the threaded hole is opened on the first fixing part 210.

[0050] As Figure 2 shown, the second fixing part 220 is a trapezoidal block with a gradually changing outer diameter. The large outer diameter end of the second fixing part 220 is fixedly connected to the first fixing part 210, so that a stepped surface is formed between the second fixing part 220 and the first fixing part 210.

[0051] The small outer diameter end of the second fixing part 220 is fixedly connected to the first end part 110. The small outer diameter end of the second fixing part 220 has the same outer diameter as the first end part 110, so as to form an arc-shaped wall surface between the second fixing part 220 and the first end part 110, and further form an arc-shaped transition surface between the second fixing part 220 and the first end part 110, preventing stress concentration and improving the connection strength between the second fixing part 220 and the first end part 110.

[0052] As Figure 3 shown, in one embodiment, the axis of at least one threaded hole forms an angle with the first direction, and the first direction is perpendicular to the plane where the first fixing part 210 is located; the axes of the remaining threaded holes are parallel to the first direction. The threaded holes are inclined relative to the first direction, so that the fixing screws 300 installed in the threaded holes are perpendicular to the surface of the split metacarpal bone, improving the connection strength between the fixing screws 300 and the split metacarpal bone.

[0053] Exemplarily, the angle between the axis of the threaded hole and the first direction is in the range of 0° - 45°. Exemplarily, the angle between the axis of the threaded hole and the first direction is 30°. Exemplarily, the angle between the axis of the threaded hole and the first direction is 45°.

[0054] In another embodiment, the angle between the axis of the threaded hole and the first direction is in the range of 45° - 70°. Exemplarily, the angle between the axis of the threaded hole and the first direction is 50°. Exemplarily, the angle between the axis of the threaded hole and the first direction is 70°.

[0055] During use, it is necessary to first determine the number of split metacarpal bones of the patient, then select the number of threaded holes to be opened, and it is necessary to first determine the fracture angle and position of the split metacarpal bones of the patient before selecting the opening angle of the axis of the threaded hole relative to the plane where the first fixing part 210 is located.

[0056] As Figure 2 shown, in one embodiment, a part of the inner wall surface of some threaded holes is located on the step surface between the second fixing part 220 and the first fixing part 210. For the convenience of description, the threaded holes with part of their inner walls located at the step surface are named overlapping threaded holes. Exemplarily, in one embodiment, the overlapping threaded holes form an angle greater than 45° with the first direction, and part of the inner wall surface of the overlapping threaded holes is located on the step surface, which can increase the thickness of the overlapping threaded holes and thus improve the strength of the overlapping threaded holes.

[0057] As Figure 2As shown, in one embodiment, when multiple threaded holes are provided, the threaded holes are equally or unequally divided into two groups. The two groups of threaded holes are respectively a first hole group 400 and a second hole group 450. The first hole group 400 is distributed along a first trajectory 410, and the second hole group 450 is distributed along a second trajectory 460. The first trajectory 410 is perpendicular to the second trajectory 460.

[0058] Exemplarily, four threaded holes are provided. The four threaded holes are equally divided into two groups. The first hole group 400 includes two threaded holes, and the second hole group 450 includes two threaded holes. Exemplarily, as Figure 2 shown, the two threaded holes in the second hole group 450 are coincident threaded holes.

[0059] As Figure 3 and Figure 4 shown, in one embodiment, the axes of the threaded holes in the second hole group 450 form an angle with each other, and the angle is greater than 10° and less than 45°. Also, the axes of the threaded holes in the second hole group 450 form an angle with the axes of the threaded holes in the first hole group 400, and the angle is greater than 10° and less than 45°.

[0060] As Figure 3 and Figure 4 shown, in one embodiment, when more than two threaded holes are provided, the axes of at least two threaded holes form an angle.

[0061] As Figure 5 shown, in one embodiment, the fixing screw 300 has a head and a shank, and external threads are provided on the head and the shank; the head is in threaded engagement with the threaded hole; the shank is in threaded engagement with the metacarpal bone. In another embodiment, the fixing screw 300 has a head and a shank, external threads are provided on the head and the shank, the shank is in threaded engagement with the threaded hole, the shank is in threaded engagement with the metacarpal bone, and the head is in threaded engagement with the step surface between the first fixing portion 210 and the second fixing portion 220.

[0062] In one embodiment, from the first end 110 to the second end 120, the diameter of the intramedullary nail body 100 gradually decreases. As Figure 1 or Figure 3 shown, in another embodiment, the diameter of the intramedullary nail body 100 remains the same from the first end 110 to the second end 120. In another embodiment, a rounded corner is provided at the second end 120. In another embodiment, barbs are provided at the second end 120.

[0063] As Figure 2 shown, in one embodiment, a rounded corner is provided at one end of the first fixing portion 210 away from the second fixing portion 220 to prevent scratching the patient.

[0064] In one embodiment, the intramedullary fixation device for assisting metacarpal fracture healing is made of titanium alloy.

[0065] In all the examples shown and described herein, any specific values should be construed as merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values.

[0066] It should be noted that like reference numerals and letters denote like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0067] The above-described embodiments merely represent several implementation manners of the present utility model. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the present utility model. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model.

Claims

1. An intramedullary fixation device for assisting the healing of metacarpal fractures, characterized in that: include: A medullary nail body (100), the medullary nail body (100) having a first end (110) and a second end (120), the second end (120) being inserted into the metacarpal bone; A fixing member (200), the fixing member (200) being fixedly connected to the first end portion (110), the fixing member (200) being provided with a threaded hole, and more than one threaded hole being provided; A fixing screw (300), one end of which is fixedly mounted in the threaded hole, and the other end of which is fixedly mounted on the metacarpal bone, and the number of the fixing screws (300) matches the number of the threaded holes.

2. The intramedullary fixation device for assisting metacarpal fracture healing according to claim 1, characterized in that: The medullary nail body (100) is a rod structure with an arc.

3. The intramedullary fixation device for assisting metacarpal fracture healing according to claim 2, characterized in that: The fixing member (200) comprises a first fixing portion (210) and a second fixing portion (220), wherein the second fixing portion (220) is fixedly connected to the first end portion (110), the first fixing portion (210) is fixedly connected to the second fixing portion (220), the threaded hole is opened on the first fixing portion (210), the first fixing portion (210) is a plate structure, the second fixing portion (220) is a trapezoidal block with a gradually changing outer diameter, the end with a large outer diameter of the second fixing portion (220) is fixedly connected to the first fixing portion (210), so that a step surface is formed between the second fixing portion (220) and the first fixing portion (210), the end with a small outer diameter of the second fixing portion (220) is fixedly connected to the first end portion (110), the end with a small outer diameter of the second fixing portion (220) is equal to the outer diameter of the first end portion (110), so that an arc-shaped wall surface is formed between the second fixing portion (220) and the first end portion (110).

4. The intramedullary fixation device for assisting metacarpal fracture healing according to claim 3, characterized in that: At least one of the threaded holes has an axis that forms an angle with a first direction, and the first direction is perpendicular to the plane where the first fixing portion (210) is located.

5. The intramedullary fixation device for assisting metacarpal fracture healing according to claim 4, characterized in that: A portion of the inner wall surface of a portion of the threaded hole is located on the step surface between the second fixing portion (220) and the first fixing portion (210).

6. The intramedullary fixation device for assisting metacarpal fracture healing according to claim 5, characterized in that: A rounded corner is provided on an end of the first fixing portion (210) away from the second fixing portion (220).

7. The intramedullary fixation device for assisting metacarpal fracture healing according to any one of claims 1 to 6, characterized in that: When more than two threaded holes are provided, there is an angle between the axes of at least two of the threaded holes.

8. The intramedullary fixation device for assisting metacarpal fracture healing according to claim 7, characterized in that: When a plurality of threaded holes are provided, the threaded holes are divided into two groups, the two groups of threaded holes being respectively a first hole group (400) and a second hole group (450), the first hole group (400) being distributed along a first track (410), the second hole group (450) being distributed along a second track (460), and the first track (410) being perpendicular to the second track (460).

9. The intramedullary fixation device for assisting metacarpal fracture healing according to claim 8, characterized in that: The axes of the threaded holes in the second hole group (450) are at an angle to each other, and the axes of the threaded holes in the second hole group (450) are at an angle to the axes of the threaded holes in the first hole group (400).

10. The intramedullary fixation device for assisting metacarpal fracture healing according to claim 1, characterized in that: The fixing screw (300) comprises a screw cap and a screw body, the screw cap and the screw body are provided with external threads, the screw cap is threadedly matched with the threaded hole, and the screw body is threadedly matched with the metacarpal bone.

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