Hollow screw cable fixing device for patella fracture

Abstract

The utility model relates to a hollow nail cable fixing device for patella fracture. The hollow nail cable fixing device comprises a hollow bone nail, a cable and an operation hook, the hollow bone nail is provided with a center channel, a nail cap and a nail body, wherein the nail cap and the nail body are integrally formed, and the center channel penetrates through the nail cap and the nail body. The cable is provided with a first connecting end and a second connecting end, and the first connecting end is connected with the nail cap; the operation hook is fixedly connected with the second connecting end and is configured to enable a cable to penetrate through the human tissue along the outer contour of the skeleton; wherein a first external thread is arranged on the peripheral surface of the nail cap, and a second external thread is arranged on the peripheral surface of the nail body. The patella implant can be implanted into the patella more smoothly.

Description

Technical Field

[0001] The present application belongs to the field of medical device technology, and specifically relates to a hollow nail cable fixation device for patellar fractures. Background Art

[0002] Patellar fractures are common intra-articular fractures that disrupt the integrity of the patellofemoral joint, impairing knee function and often requiring surgical treatment. There are many surgical options for patellar fractures, with the mainstream being open reduction and Kirschner wire tension band fixation, proposed by the AO in the 1950s. However, postoperative complications such as pain around the incision and pin withdrawal remain high. Furthermore, traditional fixation design concepts make percutaneous minimally invasive fixation difficult, and prolonged recovery times significantly increase perioperative risks.

[0003] The mainstream technology for fixing patellar fractures is the tension band technique. Although this technology has been continuously improved after decades of development, the results of clinical case reports show that its clinical effect is not ideal. In the prior art, there is a hollow nail cable locking system, which includes a hollow screw and a traction cable. The traction cable is connected to the nail cap. The hollow screw has a nail cap and a nail body. The size of the nail cap is larger than the size of the nail body. The outer surface of the nail cap and the outer surface of the nail body are smoothly transitioned, and only the tail end of the nail body is provided with an external thread; however, because the size of the nail cap is larger than the size of the nail body, there is a large resistance during the implantation of the hollow screw into the patella, the implantation process is not smooth, and bone splitting is likely to occur at the contact position between the nail cap and the bone, thereby affecting the treatment effect. Utility Model Content

[0004] In view of the above analysis, the embodiments of the present invention are intended to provide a hollow nail-cable fixation device for patellar fractures, so as to solve one or more of the above problems existing in the prior art.

[0005] The purpose of this utility model is achieved in this way:

[0006] A hollow nail-cable fixation device for patellar fracture, comprising:

[0007] A hollow bone screw having a central channel and an integrally formed screw cap and screw body, wherein the central channel passes through the screw cap and the screw body;

[0008] a cable having a first connection end and a second connection end, wherein the first connection end is connected to the nail cap;

[0009] an operating hook, the operating hook being fixedly connected to the second connecting end and configured to pass the cable through human tissue along the outer contour of the skeleton;

[0010] Wherein, a first external thread is provided on the outer circumference of the nail cap, and a second external thread is provided on the outer circumference of the nail body.

[0011] Furthermore, the first connection end of the cable is detachably connected to the nail cap via a conversion screw; or the first connection end of the cable is welded or integrally formed with the nail cap.

[0012] Furthermore, a fastening external thread is provided at the first end of the adapter screw, and an internal thread compatible with the fastening external thread is provided in the central channel located at one end of the nail cap. The first end of the adapter screw is threadedly connected to the nail cap through the internal thread, and the second end of the adapter screw is fixedly connected to the first connecting end of the cable.

[0013] Furthermore, an elastic locking mechanism is provided on the nail cap, and the elastic locking mechanism is provided on the side wall of the nail cap, and is configured to clamp the tail end of the adapter screw after the adapter screw is installed in place.

[0014] Furthermore, the first external thread is provided with a first axial groove, and the second external thread is provided with a second axial groove.

[0015] Furthermore, the first axial groove and the second axial groove are both V-shaped axial grooves as a whole.

[0016] Furthermore, the straight line where the V-shaped tip of the first axial groove is located 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 is located and the axis of the hollow bone screw are located in a second plane; the angle between the first plane and the second plane is 45°-90°.

[0017] Furthermore, the V-shaped axial groove is an inclined V-shaped structure, and the notches of the two V-shaped axial grooves face the rotational ascending directions of the first external thread and the second external thread respectively.

[0018] Furthermore, the first axial groove axially spans 1-2 threads close to one end of the nail body; the second axial groove axially spans 3-5 threads close to one end of the nail cap.

[0019] Furthermore, the axial outer end surface of the nail cap is provided with a keyway; the central channel passes through the bottom surface of the keyway; the axial outer end of the nail cap also has an outer hexagonal column structure, the size of the outer hexagonal column structure is smaller than the outer diameter of the nail cap.

[0020] Furthermore, the hollow bone screw and the adapter screw are both metal screws, and the cable is a braided metal steel cable.

[0021] Furthermore, the nail body has a polished rod section and a threaded section, and the polished rod section is located between the threaded section and the nail cap.

[0022] Compared with the prior art, the hollow nail-cable fixing device for patellar fracture provided by the present invention has at least one of the following beneficial effects:

[0023] 1. The cap of the hollow bone screw is provided with an external thread, which can be more smoothly implanted into the patella compared with the traditional hollow bone screw which only has an external thread on the screw body.

[0024] 2. Axial grooves are provided on both the external threads of the hollow bone screw cap and the external threads of the screw body, and the axial grooves at the two locations are staggered. This structural setting can increase the self-tapping force when screwing into the bone, reduce the resistance, make it easier to screw into the bone, and prevent bone splitting during the screwing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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.

[0026] Figure 1 This is a schematic structural diagram of the hollow nail-cable fixing device for patellar fracture provided by the present invention;

[0027] Figure 2 This is a disassembled schematic diagram of the hollow nail-cable fixation device for patellar fracture provided by the present invention;

[0028] Figure 3 A partial cross-sectional schematic diagram of a hollow nail-cable fixing device for patellar fracture provided by the present invention;

[0029] Figure 4 A schematic structural diagram of a first type of hollow bone nail of the hollow nail-cable fixation device for patellar fracture provided by the present invention;

[0030] Figure 5 A schematic cross-sectional view of a hollow nail-cable fixation device for patellar fractures provided by the present invention and provided with a second type of hollow bone nail;

[0031] Figure 6 A schematic structural diagram of a second type of hollow bone nail of the hollow nail-cable fixation device for patellar fracture provided by the present invention.

[0032] Reference numerals:

[0033] 1. Hollow bone screw; 11. Nail cap; 111. First axial groove; 112. Keyway; 113. Mounting hole; 114. External hexagonal column structure; 12. Nail body; 121. Second axial groove; 122. Polished rod section; 123. Threaded section; 14. Center channel;

[0034] 2. Cables;

[0035] 3. Operation hook;

[0036] 4. Adapter screws;

[0037] 5. Elastic locking mechanism; 51. Externally threaded tube; 52. Spring; 53. Ball. DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] 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.

[0041] Example 1

[0042] A specific embodiment of the present invention is as follows Figures 1 to 4 As shown, a hollow nail cable fixing device for patellar fracture is disclosed, comprising:

[0043] A hollow bone screw 1 having a central channel 14 and an integrally formed cap 11 and body 12, wherein the central channel 14 extends through the cap 11 and body 12; the body 12 having a polished rod section 122 and a threaded section 123, wherein the polished rod section 122 is located between the threaded section 123 and the cap 11;

[0044] A cable 2, the cable 2 having a first connection end and a second connection end, the first connection end being connected to the nail cap 11;

[0045] an operating hook 3, the operating hook 3 being fixedly connected to the second connection end and configured to pass the cable 2 through human tissue along the outer contour of the skeleton;

[0046] The outer circumference of the screw cap 11 is provided with a first external thread, i.e., the external thread of the threaded section 123 is the first external thread; the outer circumference of the screw body 12 is provided with a second external thread. The provision of external threads on the screw cap 11 allows 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 cable 2 and the hollow bone screw 1 may be connected in a detachable manner, or in a welding or integrally formed manner.

[0048] When the first connecting end of the cable 2 is welded or integrally formed with the nail cap, the entire hollow nail cable fixing device can be understood as a semi-hollow structure, that is, the hollow bone nail part at the front end is hollow, and the cable part at the rear end is solid.

[0049] In the embodiment where the cable 2 and the nail cap 11 are detachably connected, the first connection end of the cable 2 is detachably connected to the nail cap via an adapter screw. Specifically, the first end of the adapter screw 4 is provided with a fastening external thread, and the central channel 14 at one end of the nail cap 11 is provided with an internal thread that matches the fastening external thread. The first end of the adapter screw 4 is threadedly connected to the nail cap 11 via the internal thread; the second end of the adapter screw 4 is fixedly connected to the first connection end of the cable 2.

[0050] Optionally, the adapter screw 4 is integrally formed with the cable 2, enabling the cable 2 and the adapter screw 4 to form an integrated structure. After the adapter screw 4 is installed in the hollow bone screw 1, the cable 2 is prevented from loosening or slipping, and the nail and cable can interact with each other, thereby greatly improving stability. Of course, it is understood that the cable 2 can also be fixed to the adapter screw 4 by welding or clamping.

[0051] In one optional embodiment, Figures 5 and 6As shown, the nail cap 11 may also be provided with an elastic locking mechanism 5, which is disposed on the side wall of the nail cap 11 and is configured to clamp the tail end of the adapter screw 4 after the adapter screw 4 is installed. The elastic locking mechanism 5 has an extended state and a compressed state. During the installation of the adapter screw 4, the elastic locking mechanism 5 is in a compressed state, being squeezed and compressed by the adapter screw 4; before and after the adapter screw 4 is installed, the elastic locking mechanism 5 is in an extended state. Optionally, a mounting hole 113 is provided on the side wall of the nail cap 11, and the mounting hole 113 is connected to the internal space of the nail cap 11. The elastic locking mechanism 5 is installed in the mounting hole 113. The front end of the elastic locking mechanism 5 can extend from the mounting hole 113 into the central channel 14 within the range of the nail cap 11, and can also be retracted into the mounting hole 113. Exemplarily, the mounting hole 113 on the side wall of the nail cap 11 is a screw hole, and the elastic locking mechanism 5 includes an externally threaded tube 51, a spring 52 and a ball 53. The externally threaded tube 51 is installed in the mounting hole 113, and the ball 53 and the spring 52 are installed in the externally threaded tube 51. The first end of the spring 52 abuts the bottom wall surface of the first end of the externally threaded tube 51, and the other end of the spring 52 abuts the ball 53; the second end of the externally threaded tube 51 is open, and the size of the opening of the second end is smaller than the diameter of the ball 53. A part of the ball 53 can extend out of the second end opening of the externally threaded tube 51, and the position of the second end of the externally threaded tube 51 in the central channel 14 within the range of the nail cap 11 does not affect the installation of the adapter screw 4. When the ball 53 extends out of the second end opening, it can clamp the tail end of the adapter screw 4, thereby preventing the adapter screw 4 from falling off.

[0052] In one optional embodiment, a protruding latching portion is provided on the outer wall of the adapter screw 4 near the cable 2, and an arc-shaped latching slot is provided on the inner threaded side wall of the central channel 14 at one end of the nut 11. The notch of the arc-shaped latching slot is located at the edge of the channel opening of the central channel 14 on the bottom surface of the keyway 112. The arc-shaped latching slot extends in an arc-shaped trajectory in the side wall of the nail cap toward the nail body, and the curvature of the arc-shaped trajectory corresponds to the rotational arc of the external thread of the adapter screw 4. When the adapter screw 4 is screwed into the central channel 14, the latching portion rotates with the adapter screw 4 and gradually approaches the notch of the arc-shaped latching slot. When the adapter screw 4 is screwed into place, the latching portion can be locked into the notch of the latching slot and move along the arc-shaped trajectory defined by the latching slot to the innermost end of the latching slot, completing the installation of the adapter screw 4. The above structure is simple to set up and can prevent the adapter screw 4 from falling out without additional equipment. Even if the threads of the adapter screw 4 fail, it will not easily fall out, thereby improving the working reliability of the fixing device. In order to install the adapter screw 4 more accurately, a first mark is provided on the adapter screw 4 and a second mark is provided on the nail cap 11. When starting to install the adapter screw 4, it is necessary to align the first mark and the second mark first, and then start to screw and install the adapter screw after alignment, so that the card part can just be inserted into the slot of the card slot.

[0053] 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.

[0054] To facilitate smoother screwing of the hollow bone screw into the patella, a first axial groove 111 is provided on the first external thread, and a second axial groove 121 is provided on the second external thread. Both the first axial groove 111 and the second axial groove 121 are V-shaped axial grooves. 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.

[0055] In one optional embodiment, the straight line where the V-shaped tip of the first axial groove 111 is located and the axis of the hollow bone screw 1 are located in a first plane; the straight line where the V-shaped tip of the second axial groove 121 is located and the axis of the hollow bone screw 1 are located in a second plane; and the angle between the first plane and the second plane is 45°-90°.

[0056] Furthermore, the first axial groove 111 and the second axial groove 121 are both inclined V-shaped axial grooves, and the notches of the two axial grooves face the direction of the external threads on the nail cap 11 and the nail body 12. In other words, the V-shaped axial groove is an inclined V-shaped structure, and the notches of the two V-shaped axial grooves face the direction of the first external thread and the second external thread, respectively.

[0057] Furthermore, the first axial groove 111 axially spans 1-2 threads close to one end of the nail body 12 ; the second axial groove 121 axially spans 3-5 threads close to one end of the nail cap 11 .

[0058] In summary, 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 can be screwed into the bone more conveniently, preventing bone splitting during the screwing process.

[0059] In this embodiment, the axial outer end surface of the nail cap 11 is provided with a keyway 112, wherein the keyway 112 can be a cross groove, a plum blossom groove or a polygonal groove; the central channel 14 passes through the bottom surface of the keyway 112, and the keyway 112 is configured to use a tool to screw the hollow bone screw 1 into the patella to complete the initial operation of the surgery.

[0060] When screwing the hollow bone screw into the bone, the keyway 112 can be used to smoothly insert the screw. However, when the hollow bone screw needs to be removed later, the keyway 112 may fail due to improper operation during the screwing process, making it difficult to remove the hollow bone screw. Based on this, in one optional method of this embodiment, Figures 5 and 6As shown, the outer axial end of the cap 11 further includes an outer hexagonal column structure 114. The outer hexagonal column structure 114 is smaller than the outer diameter of the cap 11 and is coaxially arranged with the cap 11. The keyway 112 is provided on the outer hexagonal column structure 114, and the two are coaxial. This structural arrangement allows for more reliable removal of the hollow bone screw 1 by using the outer hexagonal column structure 114 in conjunction with a corresponding tool if the keyway 112 fails.

[0061] In this embodiment, the hollow bone screw 1 and the adapter screw 4 are both metal nails, or made of other hard materials, and the hardness and other parameters of the hollow bone screws can meet the requirements; the cable 2 can be a braided metal steel cable, or made of a composite polymer material.

[0062] When using the hollow nail-cable fixation device for patellar fractures, a Kirschner wire is first driven into the bone to be fixed. A hollow bone screw 1 is then placed over the Kirschner wire and screwed into the bone at the predetermined position. After reduction, there is no need for cannulated drilling or secondary screw insertion, which can cause fracture displacement and minimize bone loss. Open reduction is also unnecessary, facilitating early recovery after bone surgery. After the Kirschner wire is removed, an adapter screw 4 securely connects the cable 2 to the hollow bone screw 1, further improving the success rate and effectiveness of the surgery.

[0063] Compared with the prior art, the hollow nail-cable fixation device for patellar fracture provided in this embodiment has the following beneficial effects:

[0064] 1. 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, the hollow bone screw can be implanted into the patella more smoothly and has better stability after implantation.

[0065] 2. Axial grooves are provided 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. This structural setting can increase the self-tapping force when screwing into the bone, reduce the resistance, make it easier to screw into the bone, and prevent bone splitting during the screwing process.

[0066] 3. Through the combined design structure of hollow bone screws, adapter screws and cables, there is no need for secondary screw insertion after one-time installation, which will not cause bone loss. In addition, the hollow screw can be used to guide the positioning of the guide needle, eliminating the need for incision, reduction and re-finding of the screw tunnel, thereby improving the success rate and effectiveness of the operation and reducing damage to the patella.

[0067] 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. A hollow nail cable fixing device for patellar fracture, characterized in that: include: A hollow bone screw (1), the hollow bone screw (1) having a central channel (14) and an integrally formed nail cap (11) and a nail body (12), wherein the central channel (14) passes through the nail cap (11) and the nail body (12); A cable (2), the cable (2) having a first connection end and a second connection end, the first connection end being connected to the nail cap (11); an operating hook (3), the operating hook (3) being fixedly connected to the second connection end and configured to pass the cable (2) through human tissue along the outer contour of the skeleton; Wherein, a first external thread is provided on the outer peripheral surface of the nail cap (11), and a second external thread is provided on the outer peripheral surface of the nail body (12).

2. The hollow nail cable fixing device for patellar fracture according to claim 1, characterized in that: The first connection end of the cable (2) is detachably connected to the nail cap (11) via a conversion screw (4); Alternatively, the first connection end of the cable (2) and the nail cap (11) are welded or integrally formed.

3. The hollow nail cable fixing device for patellar fracture according to claim 2, characterized in that: The nail cap (11) is provided with an elastic locking mechanism, which is arranged on the side wall of the nail cap (11) and is configured to clamp the tail end of the adapter screw (4) after the adapter screw (4) is installed in place.

4. The hollow nail cable fixing device for patellar fracture according to claim 1, characterized in that: The first external thread is provided with a first axial groove (111), and the second external thread is provided with a second axial groove (121); the first axial groove (111) and the second axial groove (121) are both V-shaped axial grooves as a whole.

5. The hollow nail cable fixing device for patellar fracture according to claim 4, characterized in that: The straight line where the V-shaped tip of the first axial groove (111) is located and the axis of the hollow bone screw (1) are located in a first plane; the straight line where the V-shaped tip of the second axial groove (121) is located and the axis of the hollow bone screw (1) are located in a second plane; the angle between the first plane and the second plane is 45°-90°.

6. The hollow nail cable fixing device for patellar fracture according to claim 4, characterized in that: The V-shaped axial groove is an inclined V-shaped structure, and the notches of the two V-shaped axial grooves face the rotational ascending directions of the first external thread and the second external thread respectively.

7. The hollow nail cable fixing device for patellar fracture according to any one of claims 4 to 6, characterized in that: The first axial groove (111) axially spans 1-2 threads close to one end of the nail body (12); The second axial groove (121) axially spans 3-5 threads close to one end of the nail cap (11).

8. The hollow nail cable fixing device for patellar fracture according to claim 1, characterized in that: The axial outer end surface of the nail cap (11) is provided with a keyway (112); the axial outer end of the nail cap (11) is also provided with an outer hexagonal column structure.

9. The hollow nail cable fixing device for patellar fracture according to claim 7, characterized in that: The hollow bone screw (1) and the adapter screw (4) are both metal nails, and the cable (2) is a braided metal steel cable.

10. The hollow nail cable fixing device for patellar fracture according to claim 1, characterized in that: The nail body (12) comprises a polished rod section (122) and a threaded section (123), wherein the polished rod section (122) is located between the threaded section (123) and the nail cap (11).

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