Absorbable nail cable system for patella fixation

Abstract

The utility model relates to an absorbable nail cable system for patella fixation, which comprises a hollow bone nail and a cable, and the cable and the hollow bone nail are both made of absorbable materials; the front end of the cable is fixedly connected with the hollow bone nail in an injection molding mode. The hollow bone nail and the cable are both made of absorbable materials and can be absorbed by a human body after being implanted, and harm to a patient is reduced; the cable and the hollow bone nail are fixedly connected in an injection molding mode, the front end weaving section at the front end of the cable is integrated into the side wall of the hollow bone nail and is integrated with the side wall of the hollow bone nail, it is guaranteed that the hollow bone nail has enough hardness, and the connection stability between the cable and the hollow bone nail is improved.

Description

Technical Field

[0001] The present application belongs to the field of medical device technology, and in particular relates to an absorbable nail cable system for patella fixation. Background Art

[0002] Patellar fracture is a common intra-articular fracture. Patellar fracture destroys the integrity of the patellofemoral joint, resulting in affected knee joint function, and most cases require surgical treatment. The purpose of the surgery is to restore the flatness of the patellar surface and firmly fix it to meet the needs of early functional rehabilitation of the knee joint. There are many surgical methods for patellar fractures. The mainstream is still the open reduction and Kirschner wire tension band fixation proposed by the AO organization in the 1950s. However, postoperative complications such as pain around the incision and pin withdrawal remain high. In addition, it is difficult to carry out percutaneous minimally invasive fixation based on the traditional fixation design concept. The long recovery time and other problems greatly increase the perioperative risk. According to statistical studies, about 47% of patients have symptoms caused by internal fixation stimulation, and 15% of patients have to remove the internal fixation early due to local complications.

[0003] The mainstream technique for patellar fracture fixation is the tension band technique. Despite decades of development and continuous refinement, clinical case reports indicate suboptimal clinical results. With the continuous advancement of biomechanical research and treatment concepts, domestic and international scholars have attempted to mitigate risks through improved surgical procedures, new instruments, and robotic navigation.

[0004] A conventional hollow nail-cable locking system for patellar fractures includes a hollow screw, a set screw, and a pull cable. One end of the set screw is threadedly connected to the hollow screw, while the other end of the set screw is fixedly connected to the pull cable. Both the hollow screw and the set screw are made of metal, while the pull cable is made of a metal steel cable or a composite material. This hollow nail-cable locking system requires removal from the body later, which can cause some damage to the patient. Furthermore, due to its material, this hollow nail-cable locking system cannot be absorbed by the body, which can cause local complications and require prior removal, compromising the treatment effect. Utility Model Content

[0005] In view of the above analysis, the embodiments of the present invention are intended to provide an absorbable nail-cable system for patella fixation, so as to solve one or more of the above problems existing in the prior art.

[0006] The purpose of this utility model is achieved in this way:

[0007] An absorbable nail-cable system for patella fixation comprises a hollow bone screw and a cable, both of which are made of absorbable material; the front end of the cable is fixedly connected to the hollow bone screw by injection molding.

[0008] Furthermore, it also includes an operating hook, which is made of absorbable material and is fixedly connected to the rear end of the cable by injection molding.

[0009] Furthermore, the hollow bone screw has a nail cap, a nail body, a nail tip and a central channel running through the nail cap, the nail body and the nail tip.

[0010] Furthermore, the front end of the cable has a front fusion section;

[0011] The front end fusion section is a hollow cylindrical structure; or, the front end fusion section includes a plurality of scattered single lines.

[0012] Furthermore,

[0013] Furthermore, the front fusion section of the cable is a front braided section, and the front braided section is fixed in the channel wall of the central channel.

[0014] Furthermore, the front braided section is a hollow cylindrical structure, and the front braided section extends from the nail cap into the nail body, and is fixedly connected to the nail cap and the nail body at the same time.

[0015] Furthermore, the axial length of the nail cap is L1, the axial length of the nail body is L2, the length of the front end braided segment is L3, and L3>L1.

[0016] Furthermore, L3=L1+(0.8-1.0)×L2.

[0017] Furthermore, the front end braided section is a cylindrical hollow tube structure.

[0018] Furthermore, the front braided section is a grid-like structure braided from multiple single wires.

[0019] Furthermore, the length of the nail body is 12-80 mm, the length of the nail cap is 3-8 mm, the diameter of the central channel is 1.2-1.5 mm; the side wall thickness of the nail body is 1.3-1.5 mm; the diameter of the single wire of the front braided segment is 0.1-0.5 mm, the diameter of the front braided segment is 2-3 mm, and the area of ​​a single mesh on the front braided segment is 1-2 mm. 2 .

[0020] Compared to existing technologies, the absorbable nail-cable system for patellar fixation provided by this utility model features a hollow bone screw and cable made of absorbable materials. After implantation, the cable is absorbed by the body, eliminating the need for surgical removal and minimizing harm to the patient. The cable is fixedly connected to the hollow bone screw using injection molding. The front fusion section of the cable is of a certain length and integrated into the side wall of the hollow bone screw, forming an integrated structure. This not only ensures sufficient rigidity for the hollow bone screw but also enhances the stability of the connection between the cable and the hollow bone screw. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this specification. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1 A schematic structural diagram of the absorbable nail-cable system for patella fixation provided by the present invention;

[0023] Figure 2 A schematic structural diagram of the front end braided section of the cable provided by the present invention;

[0024] Figure 3 This is a partial cross-sectional schematic diagram of the absorbable nail-cable system for patella fixation provided by the present invention.

[0025] Reference numerals:

[0026] 1. Hollow bone screw; 11. Nail cap; 12. Nail body; 13. Nail tip; 14. Center channel; 2. Cable; 21. Front braided section; 22. Back braided section; 3. Operating hook. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. It should be noted that, in the absence of conflict, the embodiments in this disclosure and the features in the embodiments can be combined, separated, interchanged and / or rearranged with each other. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0028] In the accompanying drawings, the sizes and relative sizes of components may be exaggerated for clarity and / or descriptive purposes. When the exemplary embodiments can be implemented differently, the specific process sequence may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously or in a reverse order from the described order. In addition, the same reference numerals represent the same components.

[0029] The terms used herein are for the purpose of describing specific embodiments and are not intended to be restrictive. As used herein, unless the context clearly indicates otherwise, the singular forms "one (kind, person)" and "said (the)" are also intended to include plural forms. In addition, when the terms "comprise" and / or "include" and their variations are used in this specification, the features, integral bodies, steps, operations, parts, assemblies and / or their groups stated are explained, but the presence or addition of one or more other features, integral bodies, steps, operations, parts, assemblies and / or their groups is not excluded. It should also be noted that, as used herein, the terms "substantially", "approximately" and other similar terms are used as approximate terms and not as degree terms, so that they are used to explain the inherent deviations of the measured values, calculated values ​​and / or the values ​​provided that will be recognized by those of ordinary skill in the art.

[0030] Example 1

[0031] A specific embodiment of the present invention is as follows Figures 1 to 3 As shown, an absorbable nail cable system for patella fixation is disclosed, comprising:

[0032] A hollow bone screw 1, comprising a screw cap 11, a screw body 12 and a screw tip 13;

[0033] A cable 2 having a front fusion section extending from the nail cap 11 into the nail body 12 and fixedly connected to both the nail cap 11 and the nail body 12;

[0034] Wherein, the cable 2 and the hollow bone screw 1 are both made of absorbable materials.

[0035] It should be noted that the front-end fusion section of the cable 2 can be a plurality of scattered single wires, and the plurality of scattered single wires are evenly fused into the side walls of the nail cap 11 and the nail body 12; or, it can be a hollow cylindrical structure with a mesh woven from a plurality of single wires; or, it can be a pre-injection-molded hollow cylindrical structure without a mesh; or, it can be a strip structure, or a grid structure. It is understandable that the front-end fusion section of the cable 2 of the present application can also adopt other forms, as long as at least a part of the front end of the cable 2 is fused into the nail cap and the nail body, it falls within the scope of protection of the present application. Therefore, the front-end fusion section of the cable 2 of the present application includes but is not limited to the above-mentioned structural forms, and front-end fusion sections of various shapes and structures fall within the scope of protection of the present application.

[0036] Exemplarily, the front fusion section of the cable 2 is a hollow cylindrical structure with a mesh formed by braiding multiple single wires. Next, the example of the front fusion section of the cable 2 being a hollow cylindrical structure with a mesh is described in detail. Specifically, the front fusion section of the cable 2 is a front braided section 21. In other words, the cable 2 has a front braided section 21, which is a hollow cylindrical structure. The front braided section 21 extends from the nail cap 11 into the nail body 12 and is fixedly connected to both the nail cap 11 and the nail body 12.

[0037] In this embodiment, the axial length of the nail cap 11 is L1, the axial length of the nail body 12 is L2, the length of the front braided section 21 of the cable 2 is L3, and L3>L1. Preferably, L3=L1+(0.8-1.0)×L2.

[0038] In this embodiment, the hollow bone screw 1 has a central channel 14, which passes through the nail cap 11, the nail body 12 and the nail tip 13. The front end braided segment 21 of the cable 2 is located between the inner wall and the outer wall of the central channel 14. The front end braided segment 21 of the cable 2 is fixed in the channel wall of the central channel 14, that is, the front end braided segment 21 of the cable 2 extends from the side wall of the nail cap 11 to the side wall of the nail body 12, and is fixed to the nail cap 11 and the nail body 12. The front end braided segment 21 of the cable 2 is located in the side walls of the nail cap 11 and the nail body 12, which can not only improve the hardness of the hollow bone screw 1, but also make the connection stability of the cable 2 and the hollow bone screw 1 better.

[0039] In one optional embodiment, the front braided segment 21 of the cable 2 is connected to the hollow bone screw 1 by integral injection molding. Specifically, the front braided segment 21 is fixedly connected to the screw cap 11 and the screw body 12 by integral injection molding. Because the front braided segment 21 at the front of the cable 2 has a certain length, the front braided segment 21 is not connected to the hollow bone screw 1 only at the screw cap 11, but extends all the way into the screw body 12 of the hollow bone screw 1, forming an integral structure with the side wall of the hollow bone screw 1. This not only ensures that the hollow bone screw 1 has sufficient hardness, but also makes the connection between the cable 2 and the hollow bone screw 1 more stable, improves the treatment effect, and eliminates the need to remove the screw later, reducing harm to the patient.

[0040] In this embodiment, the front braided section 21 is a cylindrical hollow tube structure. The front braided section 21 of the cylindrical hollow tube structure is a grid structure formed by weaving multiple single wires, that is, the tube wall of the front braided section 21 is a grid structure. Since the hollow bone screw 1 has different sizes, the length of the nail body 12 of the hollow bone screw 1 is 12-80mm, the length of the nail cap 11 is 3-8mm, the maximum diameter of the external thread on the nail body 12 is 4-5mm, and the diameter of the central channel 14 is 1.2-1.5mm, such as 1.3mm; the side wall thickness of the nail body 12 is 1.3-1.5mm, such as 1.45mm; the parameters of the front braided section 21 are: the diameter of the single wire is 0.1-0.5mm, the diameter of the front braided section 21 of the cylindrical hollow tube structure is 2-3mm, and the area of ​​a single mesh on the front braided section 21 is 1-2mm 2 The above parameter combination can make the hollow bone screw 1 have a sufficiently large hardness, and the connection between the cable 2 and the hollow bone screw 1 is more stable.

[0041] Due to differences in material properties, if the entire hollow bone screw 1 is directly made of absorbable material, its hardness is much lower than that of a metal bone screw. The front end braided segment 21 of the cable 2 is extended from the nail cap 11 to the nail body 12 by injection molding, and is fused with the nail cap 11 and the nail body 12 as a part of the layer, that is, the front end braided segment 21 serves as a part of the side wall of the hollow bone screw 1. This can increase the overall hardness of the nail body 12 to a hardness that meets the requirements for treating patellar fractures. In addition, such a structural setting can also prevent local damage to the hollow bone screw 1 made of absorbable material due to excessive tension on the cable 2, especially prevent the cable 2 from being pulled apart at the connection between the nail cap 11, thereby ensuring the therapeutic effect of the absorbable nail-cable system.

[0042] In one of the optional embodiments, the mesh density on the front braided segment 21 gradually increases from the nail tip 13 to the nail cap 11, that is, the mesh density near the nail tip 13 is smaller than the mesh density near the nail cap 11, that is, the mesh size near the nail cap 11 is smaller, and the mesh size near the nail tip 13 is larger. In this way, when the cable 2 is subjected to stress, the front braided segment can exert a more balanced tension on the entire nail body 12, thereby preventing local stress concentration from causing damage to the connection with the nail body 12 or the nail cap 11, and improving the working stability of the absorbable nail cable system.

[0043] In this embodiment, the cable 2 further includes a rear end braided segment 22 , which is formed by spirally winding a plurality of single wires. The rear end braided segment 22 is braided to transition with the front end braided segment 21 .

[0044] In this embodiment, the absorbable nail-cable system for patellar fixation further includes an operating hook 3, which is fixedly connected to the rear braided segment 22 and configured to guide the cable 2 along the outer contour of the bone through human tissue. The operating hook 3 is also made of an absorbable material and is fixedly connected to the rear braided segment 22 by injection molding. The rear braided segment 22 extends into at least a portion of the operating hook 3. In other words, a portion of the rear braided segment 22 is integrated into the operating hook 3, becoming part of the operating hook 3. This improves the stability of the connection between the rear braided segment 22 and the operating hook 3.

[0045] In one optional embodiment, the operating hook 3 is curved. For example, the arc bending angle of the operating hook 3 can be set to 30 degrees. The curved operating hook 3 fits better with the outer surface of the skeleton and can smoothly complete the threading operation.

[0046] In this embodiment, the cap 11 of the hollow bone screw 1 is provided with an external thread, and the body 12 of the hollow bone screw 1 is also provided with an external thread. This structural arrangement enables the hollow bone screw 1 to be screwed into the patella more smoothly, preventing bone splitting during the screwing process.

[0047] In this embodiment, the absorbable material includes but is not limited to absorbable polylactic acid composite materials and absorbable polycaprolactone and other medical materials with certain hardness, plasticity and degradability, which can achieve good fixation effect after the operation while reducing adverse effects on the human body.

[0048] It should be noted that the injection mold used is compatible with the outer contours of the hollow bone screw 1 and the operating hook 3. The injection mold includes a first cavity for injection molding the hollow bone screw 1 and a second cavity for injection molding the operating hook 3. When preparing an absorbable nail cable system for patellar fixation, the cable 2 is first braided. The length of the front braided segment 21 of the cable 2 and the mesh density and other parameters are determined based on the size parameters of the hollow bone screw 1. After the cable 2 is braided, the cable 2 is loaded into the injection mold so that the front braided segment 21 of the cable 2 extends into the first cavity and a portion of the rear braided segment of the cable 2 extends into the second cavity. Liquid absorbable material is injected into the first and second cavities. After solidification and molding, the absorbable nail cable system for patellar fixation is obtained.

[0049] When using the absorbable nail-cable system for patella fixation of this embodiment, a Kirschner wire is first driven into the bone to be fixed, and the hollow bone screw 1 is sleeved onto the Kirschner wire and screwed into a predetermined position in the bone.

[0050] Compared with the prior art, the absorbable nail-cable system for patella fixation provided in this embodiment has the following beneficial effects:

[0051] 1. Hollow bone screws and cables are made of absorbable materials and can be absorbed by the human body after implantation. There is no need for surgery to remove them, which reduces harm to patients.

[0052] 2. The cable and the hollow bone screw are integrally formed by injection molding. The front braided section of the cable front end has a certain length and is integrated into the side wall of the hollow bone screw. This not only ensures that the hollow bone screw has sufficient hardness, but also improves the connection stability between the cable and the hollow bone screw.

[0053] 3. The nail cap of the hollow bone screw is provided with an external thread. Compared with the traditional hollow bone screw which only has an external thread on the nail body, it can be implanted into the patella more smoothly and has better stability after implantation into the patella.

[0054] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of this application. It should be understood that the above description is only the specific implementation methods of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. An absorbable nail cable system for patella fixation, characterized in that: It comprises a hollow bone screw (1) and a cable (2), wherein the cable (2) and the hollow bone screw (1) are both made of absorbable material; the front end of the cable (2) is fixedly connected to the hollow bone screw (1) by injection molding.

2. The absorbable nail cable system for patella fixation according to claim 1, characterized in that: It also includes an operating hook (3), which is made of absorbable material. The operating hook (3) is fixedly connected to the rear end of the cable (2) by injection molding.

3. The absorbable nail cable system for patella fixation according to claim 1, characterized in that: The hollow bone screw (1) comprises a screw cap (11), a screw body (12), a screw tip (13), and a central channel (14) passing through the screw cap (11), the screw body (12), and the screw tip (13).

4. The absorbable nail cable system for patella fixation according to claim 3, characterized in that: The front end of the cable (2) has a front fusion section; The front end fusion section is a hollow cylindrical structure; or, the front end fusion section includes a plurality of scattered single lines.

5. The absorbable nail cable system for patella fixation according to claim 4, characterized in that: The front fusion section of the cable (2) is a front braided section (21), and the front braided section (21) is fixed in the channel wall of the central channel (14).

6. The absorbable nail cable system for patella fixation according to claim 5, characterized in that: The axial length of the nail cap (11) is L1, the axial length of the nail body (12) is L2, the length of the front braided section (21) is L3, and L3>L1.

7. The absorbable nail cable system for patella fixation according to claim 6, characterized in that: L3=L1+(0.8~1.0)×L2.

8. The absorbable nail cable system for patella fixation according to claim 7, characterized in that: The front end braiding section (21) is a cylindrical hollow tube structure.

9. The absorbable nail cable system for patella fixation according to claim 8, characterized in that: The front braided section (21) is a grid-like structure braided from multiple single wires.

10. The absorbable nail cable system for patella fixation according to claim 9, characterized in that: The length of the nail body (12) is 12-80 mm, the length of the nail cap (11) is 3-8 mm, the diameter of the central channel (14) is 1.2-1.5 mm; the side wall thickness of the nail body (12) is 1.3-1.5 mm; The diameter of the single wire of the front braided section (21) is 0.1-0.5 mm, the diameter of the front braided section (21) is 2-3 mm, and the area of ​​a single mesh on the front braided section (21) is 1-2 mm. 2 .

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