Absorbable rib fixation pin

Abstract

The utility model discloses a kind of absorbable rib fixation nails, made of high molecular absorbable material integrated, including shank part and the clamping portion of both ends of shank part, clamping portion is equipped with bifurcation structure with opening towards non-connection shank part one end, at least one branch outside of bifurcation structure is equipped with inverted tooth structure, inverted tooth structure end is conical or triangular, the width of bifurcation structure is greater than the width of shank part.The utility model can be made into nail body by absorbable material, clamping portion end bifurcation, inverted tooth structure can be fixed after being expanded in marrow cavity and increasing friction, wide conical end is easily placed into marrow cavity and can play anti-rotation, anti-removal effect, fixed firm and not easy to displace, without suture reinforcement to prevent affecting periosteal blood supply and nerve compression, after fracture healing, fixation nail can be degraded and absorbed, without secondary operation removal, after absorption, chest CT, MRI examination has no influence, more promotional, can better improve the user's use experience.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to an absorbable rib fixation nail. Background Technology

[0002] Rib fractures are the most common type of chest trauma, accounting for over 60% of all chest injuries. Treatment methods for rib fractures are varied, broadly categorized into conservative and surgical approaches. For rib fractures with poor alignment, especially in patients with flail chest who have not undergone anatomical reduction, surgical internal fixation is often necessary.

[0003] There are currently various methods for internal fixation of rib fractures, such as Kirschner wire fixation, steel wire, ceramic nails and rib plates, steel wire binding fixation, shape memory alloy circumferential fixation, and absorbable rib nail internal fixation.

[0004] When using rib plates, a suitable plate must be selected based on the shape of the rib, and the plate must be pre-shaped according to the curvature of the rib. The plate is then placed on the lateral surface of both ends of the fracture and fixed to the fracture site with screws. The disadvantages of plate fixation include the possibility of displacement and breakage, and significant foreign body sensation in the patient.

[0005] Wire fixation requires drilling holes in the ribs at both ends of the fracture to allow the wire to pass through. The wire is then threaded through the holes and wrapped around the fracture site to secure the fracture ends. The wire is tightened to ensure a firm fixation, and then any excess is cut off. Post-operative activity may cause the wire to loosen, requiring further surgery for fixation. The wire can also cause damage to surrounding soft tissues.

[0006] The first step in rib claw fixation is to select a rib claw of appropriate size and place it at both ends of the fracture. The fracture ends are then secured using a locking device on the claw. However, rib claw fixation can also be unstable, and the claw may compress intercostal nerves and blood vessels, causing pain to the patient.

[0007] Currently, rib claws are commonly used in surgery to fix rib fractures. However, rib claws have drawbacks such as insufficient fixation and a tendency to shift. Furthermore, rib claw fixation under laparoscopy can lead to extensive adhesions with pleural contents postoperatively, making removal extremely difficult. This not only affects the blood supply to the periosteum and fracture healing but also compresses the intercostal nerves located at the lower edge of the rib, causing postoperative pain. If the fixation device is located on the lateral side of the rib, it can also result in uneven fixation sites, affecting aesthetics.

[0008] Internal fixation with absorbable rib screws for rib fractures is a minimally invasive method that eliminates the need for secondary surgery and has been widely accepted by clinicians. However, existing rib screws also have drawbacks such as poor anti-rotation, easy displacement, and difficulty in laparoscopic surgery. In summary, existing rib screws, due to one or more of these design deficiencies, cannot fully meet clinical needs, thus affecting the overall quality of rib fracture treatment.

[0009] Therefore, there is a need to provide an absorbable rib fixation screw to solve the above problems. Utility Model Content

[0010] In order to solve the above-mentioned problems in the prior art, this application discloses an absorbable rib fixation nail, which is integrally molded from a polymer absorbable material and includes a nail body and snap-fit ​​parts symmetrically disposed at both ends of the nail body;

[0011] The snap-fit ​​part has a forked structure with an opening facing the end that is not connected to the nail body. At least one branch of the forked structure has a reverse tooth structure on its outer side. The end of the reverse tooth structure is conical or triangular. The width of the fork of the forked structure is greater than the width of the nail body.

[0012] Furthermore, the nail body has an arc-shaped structure, and the snap-fit ​​portion is correspondingly located at both ends of the arc-shaped structure and is set at an angle so that the nail body can adapt to the curvature of the rib after installation.

[0013] Furthermore, the total length of the arc-shaped fixing pin is 20mm-70mm.

[0014] Furthermore, the nail body is provided with a guide groove, which extends from the nail body to the fork opening of the snap-fit ​​portion.

[0015] Furthermore, the top view width of the nail body and the snap-fit ​​part is 2mm-20mm, and the fork width of the forked structure is 3mm-30mm.

[0016] Furthermore, the nail body is provided with at least one through hole, and at least one through hole is located in the middle section of the nail body.

[0017] Furthermore, a connecting portion is provided between the nail body and the snap-fit ​​portion, and the cross-section of the connecting portion is larger than the cross-section of the nail body.

[0018] Furthermore, the absorbable polymer material is polylactic acid.

[0019] The absorbable rib fixation nail provided in this application has at least the following beneficial effects:

[0020] This application utilizes a one-piece molded nail body made of absorbable polymer material with a toothed structure on both ends and a bifurcated structure at the end. This allows it to expand within the rib medullary cavity, and the wide end provides anti-rotation. The tapered design of the insertion end facilitates the placement of the fractured bone fragment into the rib medullary cavity. The toothed design increases friction with the inner surface of the medullary cavity, preventing the fixation nail from slipping out. The fractured bone fragment is securely fixed and not easily displaced, eliminating the need for suture reinforcement. Sutures will not affect the blood supply to the periosteum, thus preventing impact on fracture healing and avoiding compression of the intercostal nerves at the lower edge of the rib, which could cause postoperative pain. After the fractured bone fragment heals, the biodegradable rib fixation nail gradually degrades and is absorbed, eliminating the need for a second surgery. After absorption, it has no impact on chest CT or MRI examinations, making it more widely applicable and significantly improving the user experience. Attached Figure Description

[0021] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 : A schematic front view of the fixing nail involved in the embodiment of this application;

[0023] Figure 2 : A top view of the fixing nail involved in the embodiment of this application;

[0024] Figure 3 : A bottom view of the fixing nail involved in the embodiment of this application;

[0025] Figure 4 : A side view of the fixing nail involved in the embodiment of this application;

[0026] Figure 5 : A three-dimensional schematic diagram of the fixing nail involved in the embodiments of this application;

[0027] In the diagram: 1-nail body; 11-through hole; 12-guide groove; 13-arc-shaped structure;

[0028] 2-Snap-fit ​​part; 21-Forked structure; 211-Forked opening; 22-Reverse tooth structure;

[0029] 3-Connecting part; Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0031] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. In the description of the present invention, it should be understood that the terms "upper," "lower," "top," "bottom," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the present invention described herein can be implemented in orders other than those illustrated or described herein.

[0032] Please refer to Figure 1-5 As shown, an absorbable rib fixation nail is integrally molded from a polymer absorbable material. It includes a nail body 1 and symmetrically arranged locking portions 2 at both ends of the nail body 1. In this embodiment, the end of the locking portion 2 that is not connected to the nail body 1 is preferably conical, trapezoidal, or any shape that facilitates insertion of the locking portion 2 into the medullary cavity of the rib. The locking portion 2 has a bifurcated structure 21 with its opening facing the end of the non-connected nail body 1. At least one branch of the bifurcated structure 21 has a reverse tooth structure 22 on its outer side. This toothed design increases friction with the inner surface of the medullary cavity, preventing the fixation nail from slipping out. Combined with the high-strength bifurcated structure 21, the fixation nail is elastically fixed within the medullary cavity, while also making the overall surface of the rib fixation nail aesthetically pleasing and simple. For the same purpose, the end of the reverse tooth structure 22 is conical or triangular, and the width of the bifurcation of the bifurcated structure 21 is greater than the width of the nail body 1. The wide bifurcated structure 21 can play a role in anti-rotation and preventing dislodgement. Of course, in order to increase the resistance to rotation, the nail body 1, the snap-fit ​​part 2, and the toothed structure 22 can all be selectively designed as prisms, that is, their cross-sections are polygonal.

[0033] Based on the above technical solution, the rib fixation nail is made of a polymer absorbable material. Polylactic acid (PLA) is the preferred absorbable polymer. PLA is an important biomedical polymer material with excellent biocompatibility and bioabsorbability, and has been widely used in internal fixation of fractures, tissue engineering scaffolds, surgical sutures, and controlled drug release systems. PLA is typically synthesized using the ring-opening polymerization of lactide. Based on different optical activities, lactide is classified into D-lactide, L-lactide, and DL-lactide, and their ring-opening polymerization products are correspondingly poly-D-lactic acid, poly-L-lactic acid (PLLA), and poly-DL-lactic acid. PLLA is an important biodegradable polymer material, characterized by being non-toxic, non-irritating, biodegradable and absorbable, high in strength, highly malleable, and easy to process. The degradation period is 2–12 months. The degradation period can be altered by adding different modifiers. PLLA is enzymatically decomposed in vivo, ultimately forming carbon dioxide and water, exhibiting good biocompatibility.

[0034] Furthermore, the nail body 1 has an arc-shaped structure 13, and the locking parts 2 are correspondingly located at both ends of the arc-shaped structure 13 and set at an angle, so that the nail body can adapt to the curvature of the rib after installation. Specifically, combined with the characteristics of high polymer absorbable materials that are non-toxic, non-irritating, biodegradable and absorbable, high in strength, good in plasticity, and easy to process and shape, it can make the fracture ends firmly fixed and not easily displaced, and adapt to the curvature of the rib. The surgical operation is simple, it can conform to the shape of the rib, and the patient has no foreign body sensation after surgery.

[0035] In an optional embodiment, the total length of the arc-shaped fixing pin can be selected as 20mm-70mm.

[0036] Based on this, the nail body 1 is preferably provided with a guide groove 12. The guide groove 12 extends from the nail body 1 to the fork 211 of the locking part 2. The guide groove 12 can not only increase the overall strength of the nail body, but also guide the bone marrow to cover the entire nail body. After the nail body is implanted into the rib, as the fracture heals, the newly grown cancellous bone will grow into the guide groove 12 to fix the entire nail body.

[0037] Furthermore, the top view width of both the nail body 1 and the snap-fit ​​part 2 is preferably 2mm-20mm, and the fork width of the forked structure 21 is 3mm-30mm.

[0038] To increase structural stability and prevent the nail from coming out, a connecting part 3 is provided between the nail body 1 and the snap-fit ​​part 2. The cross-section of the connecting part 3 is larger than the cross-section of the nail body 1. After the nail is inserted, the wide connecting part 3 can play the role of anti-rotation and anti-detachment.

[0039] Furthermore, the nail body 1 is provided with at least one through hole 11, and the at least one through hole 11 is located in the middle section of the nail body 1. After the nail body is implanted into the rib, as the fracture heals, the newly grown cancellous bone will grow into the through hole 11 to fix the rib fixation nail.

[0040] The absorbable rib fixation nail provided in this application has at least the following beneficial effects:

[0041] 1. Compared with existing rib fixation nails, this nail body is integrally molded using a polymer absorbable material. The bifurcated structure of the locking part allows the nail body to be elastically fixed within the medullary cavity. Furthermore, its wide end can play an anti-rotation role, providing good anti-rotation effect. The tapered design of the insertion end facilitates the placement of the fractured bone ends into the medullary cavity of the rib.

[0042] 2. At the same time, the inverted tooth structure on the outer side of the bifurcated structure can open up the medullary cavity to prevent movement, increase the friction with the inner surface of the medullary cavity, and prevent the fixation nail from slipping out. The operation is simple, the fracture ends are not easy to shift or rotate, no sutures are needed to reinforce the fracture ends, the sutures will not affect the blood supply of the periosteum and thus not affect the fracture healing, and will not cause the intercostal nerves at the lower edge of the rib to be compressed, causing postoperative pain.

[0043] 3. The reinforcement of the connecting part, the guide groove, the through hole and the light guide the long bone, etc., are conducive to the healing of the fractured bone after surgery. In addition, the overall arc structure of the nail can fit the shape of the rib, and the patient does not have a foreign body sensation after surgery. This application is more scalable.

[0044] 4. Polylactic acid (PLLA) is used as an absorbable polymer material, especially its cyclopolymer product, poly-L-lactic acid (PLLA), which is non-toxic, non-irritating, biodegradable, absorbable, high-strength, highly malleable, and easy to process and mold. Its hardness and elastic modulus match those of normal bone, so it will not cause adjacent bone resorption. It does not limit the application of MRI examinations in the later stages of the disease. There are no artifacts in the postoperative imaging. It has good biocompatibility and will not induce tissue allergic reactions or bone autolysis when implanted in the body for a long time. After the fracture ends heal, the biodegradable rib fixation nail can be gradually degraded and absorbed without the need for a second surgery to remove it.

[0045] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application.

Claims

1. An absorbable rib fixation nail, characterized in that: The rib fixation nail is integrally molded from a polymer absorbable material and includes a nail body and snap-fit ​​parts symmetrically arranged at both ends of the nail body; The snap-fit ​​part has a forked structure with an opening facing the end that is not connected to the nail body. At least one branch of the forked structure has a reverse tooth structure on its outer side. The end of the reverse tooth structure is conical or triangular. The width of the fork of the forked structure is greater than the width of the nail body.

2. The absorbable rib fixation nail according to claim 1, characterized in that, The nail body has an arc-shaped structure, and the corresponding snap-fit ​​parts are located at both ends of the arc-shaped structure and are set at an angle so that the nail body can adapt to the curvature of the rib after installation.

3. The absorbable rib fixation nail according to claim 2, characterized in that, The total length of the arc-shaped fixing pin is 20mm-70mm.

4. The absorbable rib fixation nail according to claim 1, characterized in that, The nail body is provided with a guide groove, which extends from the nail body to the fork opening of the snap-fit ​​portion.

5. The absorbable rib fixation nail according to claim 1, characterized in that, The top view width of the nail body and the snap-fit ​​part is 2mm-20mm, and the fork width of the forked structure is 3mm-30mm.

6. The absorbable rib fixation nail according to claim 1, characterized in that, The nail body is provided with at least one through hole, and at least one through hole is located in the middle section of the nail body.

7. The absorbable rib fixation nail according to claim 1, characterized in that, A connecting portion is also provided between the nail body and the snap-fit ​​portion, and the cross-section of the connecting portion is larger than the cross-section of the nail body.

8. The absorbable rib fixation nail according to claim 1, characterized in that, The absorbable polymer material is polylactic acid.

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