Absorbable patella nail cable fixing device

Abstract

The absorbable patella nail cable fixing device comprises a hollow bone nail and a cable, and the hollow bone nail is provided with a nail cap, a nail body and a nail point; the cable is provided with a front-end fusion section, and the front-end fusion section extends into the nail body from the nail cap and is fixedly connected with the nail cap and the nail body at the same time; the cable and the hollow bone nail are made of absorbable materials. Patella fixation is achieved, the patella can be absorbed by a human body after being implanted, and harm to a patient is reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of medical devices, and in particular relates to an absorbable patellar nail-cable fixation device. Background Art

[0002] Patellar fracture is a common intra-articular fracture, accounting for about 1% of total fracture injuries, with an incidence rate of 13.5 / 100,000 person-years. Patellar fracture destroys the integrity of the patellofemoral joint, resulting in affected knee joint function, and most require surgical treatment. The purpose of the operation is to repair 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 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 needle withdrawal remain high, and it is difficult to carry out percutaneous minimally invasive fixation based on the traditional fixation design concept. Problems such as long recovery time 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 in advance due to local complications.

[0003] The mainstream technology for fixing patellar fractures is the tension band technique. Although this technology has been continuously improved over the past few decades, the results of clinical case reports show that its clinical effect is not ideal. With the continuous development of biomechanical research and treatment concepts, domestic and foreign scholars have tried to avoid risks by improving surgical procedures, inventing new instruments, and mechanical navigation.

[0004] There is a hollow nail cable locking system for patellar fracture in the prior art, which includes a hollow screw, a fastening screw and a pulling cable, one end of the fastening screw is screwed to the hollow screw, and the other end of the fastening screw is fixedly connected to the pulling cable; wherein the hollow screw and the fastening screw are both made of metal, and the pulling cable is a cable made of metal steel cable or composite material. This hollow nail cable locking system needs to be removed from the body later, which will cause certain damage to the patient; moreover, due to the material, this hollow nail cable locking system cannot be absorbed by the human body, which will cause local complications and needs to be removed before treatment, affecting the treatment effect. Summary of the invention

[0005] In view of the above analysis, an embodiment of the present invention aims to provide a patella absorbable nail cable fixation device to solve one or more of the above problems existing in the prior art.

[0006] The object of the present invention is achieved in that:

[0007] A patella absorbable nail cable fixing device, comprising:

[0008] A hollow bone screw, wherein the hollow bone screw has a screw cap, a screw body and a screw tip;

[0009] A cable, wherein the cable has a front fusion section, wherein the front fusion 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;

[0010] Wherein, the cables and hollow bone screws are both made of absorbable materials.

[0011] Furthermore, the front fusion section is fixedly connected to the nail cap and the nail body by injection molding.

[0012] Furthermore, the axial length of the nail cap is L1, the axial length of the nail body is L2, the length of the front braided segment is L3, and L3>L1;

[0013] Preferably, L3=L1+(0.8-1.0)×L2.

[0014] Furthermore, the hollow bone screw has a central channel, and the central channel runs through the nail cap, the nail body and the nail tip;

[0015] Preferably, the front fusion section is fixed in the channel wall of the central channel.

[0016] Furthermore, the front end fusion section is a hollow cylindrical structure; or, the front end fusion section includes a plurality of scattered single wires, and the plurality of scattered single wires are evenly distributed in the channel wall of the central channel.

[0017] Furthermore, the front end fusion section is a cylindrical hollow tube structure; the front end fusion section includes a front end braiding section, and the front end braiding section is a grid structure braided by multiple single wires.

[0018] Furthermore, the front end braided section is a cylindrical hollow tube structure; the front end braided section is a grid structure woven 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 thickness of the side wall of the nail body is 1.3-1.5 mm;

[0020] Preferably, 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 .

[0021] Furthermore, the mesh density on the front braided section gradually increases from the nail tip to the nail cap.

[0022] Furthermore, the cable also has a rear end braided segment, which is formed by spirally winding a plurality of single wires, and the rear end braided segment is braided to transition with the front end braided segment.

[0023] Further, it includes an operating hook configured to pass the cable through human tissue along the outer contour of the skeleton;

[0024] Preferably, the operating hook is made of absorbable material, and the operating hook is fixedly connected to the rear end braided segment by injection molding.

[0025] Furthermore, the operating hook is curved, and the arc bending angle of the operating hook fits the outer surface of the bone.

[0026] Furthermore, both the nail cap and the nail body are provided with external threads.

[0027] Furthermore, a first axial groove is provided on the external thread of the nail cap, and the first axial groove axially spans 1-2 threads close to the end of the nail body; a second axial groove is provided on the external thread on the nail body, and the second axial groove axially spans 3-5 threads close to the end of the nail cap; and the first axial groove and the second axial groove are both V-shaped axial grooves as a whole.

[0028] Furthermore, the straight line where the V-shaped tip of the first axial groove and the axis of the hollow bone screw are located in a first plane, the straight line where the V-shaped tip of the second axial groove and the axis of the hollow bone screw are located in a second plane, and the angle between the first plane and the second plane is 45°-90°.

[0029] Furthermore, the first axial groove and the second axial groove are both inclined V-shaped axial grooves as a whole, and the notches of the two axial grooves face the screw-up direction of the external threads on the nail cap and the nail body.

[0030] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0031] a) The patella absorbable nail-cable fixation device provided by the present invention comprises a hollow bone nail and a cable made of absorbable materials, which can be absorbed by the human body after implantation, and no surgery is required to remove the nail or cable, thereby reducing harm to the patient.

[0032] b) In the absorbable patellar nail-cable fixing device provided by the present invention, the cable and the hollow bone screw are fixedly connected by injection molding. The front end fusion section of the cable has a certain length, and the front end fusion section is integrated into the side wall of the hollow bone screw, forming an integrated structure with the side wall of the hollow bone screw, which 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.

[0033] c) The absorbable patella nail-cable fixing device provided by the present invention has a hollow bone screw with an external thread on its nail cap. Compared with the traditional hollow bone screw with only 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.

[0034] d) In the absorbable patellar nail-cable fixing device provided by the present invention, the external threads of the hollow bone nail cap and the nail body are both provided with axial grooves, and the axial grooves at the two positions are staggered. Such a structural arrangement can increase the self-tapping force when screwing into the bone, reduce the resistance, make it more convenient to screw into the bone, and prevent bone splitting during the screwing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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.

[0036] Figure 1 A schematic diagram of the structure of the absorbable patellar nail-cable fixing device provided by the present invention;

[0037] Figure 2 A schematic diagram of the disassembly of the various parts of the absorbable patellar nail-cable fixing device provided by the present invention;

[0038] Figure 3 A schematic structural diagram of the front end braided section of the cable provided by the present invention;

[0039] Figure 4 A partial cross-sectional schematic diagram of the patella absorbable nail-cable fixing device provided by the present invention;

[0040] Figure 5 A schematic diagram of the partial structure of the hollow bone screw provided by the present invention.

[0041] Reference numerals:

[0042] 1. Hollow bone screw; 11. Nail cap; 111. First axial groove; 12. Nail body; 121. Second axial groove; 13. Nail tip; 14. Center channel; 2. Cable; 21. Front braided section; 22. Rear braided section; 3. Operation hook. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described in combination 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 the present disclosure and the features in the embodiments can be combined, separated, interchanged and / or rearranged with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0044] In the accompanying drawings, the size and relative size of components may be exaggerated for clarity and / or descriptive purposes. When the exemplary embodiments may be implemented differently, a specific process sequence may be performed in a different order than described. For example, two successively described processes may be performed substantially simultaneously or in an order opposite to the order described. In addition, the same reference numerals represent the same components.

[0045] The terms used here are for the purpose of describing specific embodiments, and are not intended to be restrictive. As used here, 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, it is explained that there are stated features, integral bodies, steps, operations, parts, assemblies and / or their groups, but it is not excluded that there are or add one or more other features, integral bodies, steps, operations, parts, assemblies and / or their groups. It should also be noted that, as used here, 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.

[0046] Example 1

[0047] A specific embodiment of the present invention, as Figures 1 to 5 As shown, a patella absorbable nail cable fixing device is disclosed, comprising:

[0048] A hollow bone screw 1, wherein the hollow bone screw 1 comprises a screw cap 11, a screw body 12 and a screw tip 13;

[0049] A cable 2, wherein the cable 2 has a front fusion section, wherein the front fusion section extends from the nail cap 11 into the nail body 12 and is fixedly connected to the nail cap 11 and the nail body 12;

[0050] Wherein, the cable 2 and the hollow bone screw 1 are both made of absorbable materials.

[0051] 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 in 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 in 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.

[0052] Exemplarily, the front fusion section of the cable 2 is a hollow cylindrical structure with a mesh formed by weaving multiple single wires. Next, the front fusion section of the cable 2 is a hollow cylindrical structure with a mesh as an example for detailed description. Specifically, the front fusion section of the cable 2 is a front braided section 21, that is, the cable 2 has a front braided section 21, and the front braided section 21 is a hollow cylindrical structure, and the front braided section 21 extends from the nail cap 11 to the nail body 12, and is fixedly connected to the nail cap 11 and the nail body 12 at the same time;

[0053] 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.

[0054] 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 between the cable 2 and the hollow bone screw 1 better.

[0055] In one of the optional embodiments, the front braided section 21 of the cable 2 is connected to the hollow bone screw 1 by one-piece injection molding. Specifically, the front braided section 21 is fixedly connected to the screw cap 11 and the screw body 12 by one-piece injection molding. Since the front braided section 21 at the front of the cable 2 has a certain length, the front braided section 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, and is integrated 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, and the treatment effect is better. There is no need to remove the screw at a later stage, which reduces the harm to the patient.

[0056] 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.

[0057] Due to the difference in material properties, if the hollow bone screw 1 is made of absorbable material as a whole, its hardness is much lower than that of metal bone screws, and 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 a part of the fusion layer with the nail cap 11 and the nail body 12, that is, the front end braided segment 21 is used as a part of the side wall of the hollow bone screw 1, which can increase the overall hardness of the nail body 12 to a hardness that meets the treatment of patellar fractures; in addition, such a structural setting can also avoid local damage to the absorbable hollow bone screw 1 caused by excessive tension of the cable 2, especially avoid the cable 2 and the nail cap 11 from being pulled apart at the connection, thereby ensuring the therapeutic effect of the fixation device.

[0058] 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 absorbent nail cable fixing device.

[0059] In this embodiment, the cable 2 further has a rear end braided segment 22 , which is formed by spirally winding a plurality of single wires, and the rear end braided segment 22 is braided to transition with the front end braided segment 21 .

[0060] In this embodiment, the patella absorbable nail cable system fixing device further includes an operating hook 3, which is fixedly connected to the rear end braided segment 22 and is configured to pass the cable 2 through human tissue along the outer contour of the skeleton. The operating hook 3 is also made of an absorbable material, and the operating hook 3 is fixedly connected to the rear end braided segment 22 by injection molding, and the rear end braided segment 22 extends into at least a portion of the operating hook 3, that is, a section of the rear end braided segment 22 is integrated into the operating hook 3 as a part of the operating hook 3, which can improve the connection stability between the rear end braided segment 22 and the operating hook 3.

[0061] In one of the optional embodiments, 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 the outer surface of the skeleton better and can smoothly complete the threading operation.

[0062] In this embodiment, the screw cap 11 of the hollow bone screw 1 is provided with external threads, and the screw body 12 of the hollow bone screw 1 is also provided with external threads. This structural setting can make the hollow bone screw 1 more smoothly screwed into the patella, and prevent bone splitting caused by the screwing process.

[0063] Furthermore, a first axial groove 111 is provided on the external thread of the nail cap 11, and the first axial groove 111 axially spans 1-2 threads near the end of the nail body 12; a second axial groove 121 is provided on the external thread of the nail body 12, and the second axial groove 121 axially spans 3-5 threads near the end of the nail cap 11; and the first axial groove 111 and the second axial groove 121 are both V-shaped axial grooves as a whole, that is, when viewed from one axial side to the other side of the hollow bone screw 1, the first axial groove 111 and the second axial groove 121 are V-shaped axial grooves. The axial groove 121 is V-shaped; and the straight line where the V-shaped tip of the first axial groove 111 and the axis of the hollow bone screw 1 are located in the first plane, and the straight line where the V-shaped tip of the second axial groove 121 and the axis of the hollow bone screw 1 are located in the second plane, and the angle between the first plane and the second plane is 45°-90°; further, the first axial groove 111 and the second axial groove 121 are both inclined V-shaped axial grooves as a whole, and the notches of the two axial grooves face the screw-up direction of the external threads on the nail cap 11 and the nail body 12. By setting the axial grooves with the above structural parameters on the nail cap 11 and the nail body 12, the self-tapping force can be increased when screwing into the bone, the resistance can be reduced, and it is more convenient to screw into the bone, preventing bone splitting during the screwing process.

[0064] 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 while reducing adverse effects on the human body after the operation is completed.

[0065] 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 the patella absorbable nail cable fixation device, the cable 2 is first woven, and the length of the front braided segment 21 of the cable 2 and the mesh density and other parameters are determined according to the size parameters of the hollow bone screw 1; after the cable 2 is woven, 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 part of the rear braided segment of the cable 2 extends into the second cavity, and liquid absorbable material is injected into the first cavity and the second cavity. After solidification, the patella absorbable nail cable fixation device is obtained.

[0066] When using the patella absorbable nail-cable fixation device, firstly a Kirschner wire is inserted into the bone to be fixed, and then a hollow bone screw 1 is sleeved on the Kirschner wire and screwed into a predetermined position in the bone.

[0067] Compared with the prior art, the absorbable patellar nail-cable fixing device provided in this embodiment has the following beneficial effects:

[0068] 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, thus reducing harm to patients.

[0069] 2. The cable and the hollow bone screw are formed by injection molding. The front fusion section of the cable has a certain length, and the front fusion section is integrated into the side wall of the hollow bone screw, forming an integrated structure with the side wall of the hollow bone screw, which 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.

[0070] 3. The screw 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 screw body, it can be implanted into the patella more smoothly and has better stability after implantation into the patella.

[0071] 4. Axial grooves are arranged on the external threads of the hollow bone screw cap and the external threads on the screw body, and the axial grooves at the two locations are staggered. Such a structural setting can increase the self-tapping force when screwing into the bone, reduce the resistance, make it more convenient to screw into the bone, and prevent bone splitting during the screwing process.

[0072] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only the specific implementation method of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A patella absorbable nail cable fixation device, characterized in that: include: A hollow bone screw (1), wherein the hollow bone screw (1) comprises a screw cap (11), a screw body (12) and a screw tip (13); A cable (2), the cable (2) having a front fusion section, the front fusion section extending from the nail cap (11) into the nail body (12), and fixedly connected to the nail cap (11) and the nail body (12); Wherein, the cable (2) and the hollow bone screw (1) are both made of absorbable materials.

2. The absorbable patellar nail cable fixing device according to claim 1, characterized in that: The front fusion section is fixedly connected to the nail cap (11) and the nail body (12) by injection molding.

3. The absorbable nail cable fixing device for patella according to claim 1, 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 fusion section is L3, and L3>L1; Preferably, L3=L1+(0.8-1.0)×L2.

4. The absorbable patellar nail cable fixing device according to claim 3, characterized in that: The hollow bone screw (1) has a central channel (14), and the central channel (14) passes through the screw cap (11), the screw body (12) and the screw tip (13); Preferably, the front fusion section is fixed in the channel wall of the central channel (14).

5. The absorbable nail cable fixing device for patella according to claim 4, characterized in that: The front fusion section is a hollow cylindrical structure; or, The front fusion section comprises a plurality of scattered single wires, and the plurality of scattered single wires are evenly distributed in the channel wall of the central channel (14).

6. The absorbable nail cable fixing device for patella according to claim 5, characterized in that: The front fusion section is a cylindrical hollow tube structure; the front fusion section comprises a front braided section (21), and the front braided section (21) is a grid-like structure braided from a plurality of single wires; Preferably, the mesh density on the front braided section (21) gradually increases from the nail tip (13) toward the nail cap (11).

7. The absorbable nail cable fixing device for patella according to claim 1, characterized in that: The cable (2) further comprises a rear end braided section (22), wherein the rear end braided section (22) is formed by spirally winding a plurality of single wires, and the rear end braided section (22) is braided to transition with the front end braided section (21).

8. The absorbable nail cable fixing device for patella according to claim 7, characterized in that: It also includes an operating hook (3) configured to pass the cable (2) through human tissue along the outer contour of the skeleton; Preferably, the operating hook (3) is made of absorbable material, and the operating hook (3) is fixedly connected to the rear end braided section (22) by injection molding.

9. The absorbable nail cable fixing device for patella according to claim 8, characterized in that: The operating hook (3) is curved, and the arc-shaped bending angle of the operating hook (3) fits the outer surface of the bone.

10. The absorbable nail cable fixing device for patella according to claim 1, characterized in that: The nail cap (11) and the nail body (12) are both provided with external threads.

Images