Patella fracture fixing device

Abstract

The utility model relates to a patella fracture fixing device, belongs to the technical field of medical instruments, and solves the problem of large patella loss in the prior art. The patella fracture fixing device comprises a hollow screw, one end of the hollow screw is provided with external threads, the other end of the hollow screw is provided with a through hole, and the included angle between the through hole and the axial direction of the hollow screw is an acute angle; one end of the fastening screw is arranged in the through hole in a penetrating manner; and one end of the traction cable is fixedly connected with one end, far away from the through hole, of the fastening screw. According to the patella fixator, a screw does not need to be placed for the second time during patella operation, bone loss cannot be caused, and damage to the patella is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of medical instruments, and in particular relates to a patellar fracture fixing device. Background Art

[0002] The patella is an indispensable part of the knee extension function and bears a load of about 5 times the weight of the human body during knee extension activities. The patella can effectively prevent lateral displacement of the knee joint and resist the forward sliding of the femoral condyle during the human body squatting process. The purpose of treating patellar fractures is to restore the anatomical reduction of the patellar fracture, reduce the defect caused by the patellar fracture, and repair the flatness of the patellar surface, which is conducive to early functional training of the knee joint and reduces the occurrence of complications.

[0003] At present, there are many methods for fixation of patellar fractures, such as suture fixation around the patella, patellar fixation, AO tension band fixation, cohesive patellar fixation, partial or complete patellar resection, Cable-pin system, etc. Among them, the Cable-pin system is a relatively mature and effective treatment option. The system uses semi-threaded cancellous bone compression screws and bone tunnel guide pins at both ends. The compression screws exert pressure when they are driven into the bone, and then use flexible and easy-to-tighten steel cables to achieve binding fixation, which can effectively prevent the compression screws from backing out. However, the Cable-pin system requires hollow drilling to expand the hole and pull out the guide pin during the postoperative reduction process. When the screws are inserted for the second time, the reduction fracture displacement and the inability to find the screw tunnel will occur, resulting in limited bone loss and fixation failure. In addition, because the hollow guide pin cannot be used for guidance, simple patellar fractures also need to be open and reduced, which has the technical problem of large patellar loss. Utility Model Content

[0004] In view of the above analysis, the embodiments of the present invention are intended to provide a patellar fracture fixation device to solve one or more of the above problems existing in the prior art.

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

[0006] A patella fracture fixation device, comprising:

[0007] A hollow screw, one end of which has an external thread and the other end of which has a through hole, wherein the angle between the through hole and the axial direction of the hollow screw is an acute angle;

[0008] A fastening screw, one end of which is inserted into the through hole;

[0009] A pulling cable, one end of which is fixedly connected to an end of the fastening screw away from the through hole.

[0010] Furthermore, it also includes an operating hook, which is fixedly connected to the other end of the pulling cable.

[0011] Furthermore, the operating hook is curved.

[0012] Furthermore, the through hole has an internal thread, and the fastening screw has an external thread matching the internal thread of the through hole.

[0013] Furthermore, the hollow screw has a keyway on its end surface at one end of the through hole, which is used to cooperate with a tool to rotate and drive the hollow screw to be screwed into the patella.

[0014] Furthermore, the hollow screw has a plurality of through holes, and the angle between each through hole and the axial direction of the hollow screw is an acute angle and is different from each other.

[0015] Furthermore, one end of the fastening screw connected to the pulling cable is configured as a right prism, and a radial dimension of the right prism is greater than a diameter of the through hole.

[0016] Furthermore, the hollow screw has a radial dimension of one end of the through hole that is larger than the diameter of the hollow screw.

[0017] Furthermore, the outer surface of the hollow screw at one end of the through hole is provided with an external thread.

[0018] Furthermore, the pulling cable is formed by spirally winding a plurality of steel cables.

[0019] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0020] The patella fracture fixation device provided by the utility model has a combined design structure of a hollow screw, a fastening screw and a traction cable. After a one-time installation, there is no need to insert the screw a second time, and bone loss will not be caused. The hollow screw can be used to guide the positioning of the guide needle, and there is no need for incision reduction and re-searching for the screw placement tunnel, which improves the success rate and effectiveness of the operation and reduces damage to the patella. 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 The structure diagram of the patella fracture fixation device provided by the utility model is as follows Figure 1 ;

[0023] Figure 2A schematic diagram of the structure of the hollow screw provided by the utility model;

[0024] Figure 3 A schematic diagram of the working of the patella fracture fixation device provided by the utility model;

[0025] Figure 4 A schematic diagram of the combination of the fastening screw, the pulling cable and the operating hook provided by the utility model;

[0026] Figure 5 The structure diagram of the patella fracture fixation device provided by the utility model is as follows Figure 2 .

[0027] Reference numerals:

[0028] 1-hollow screw; 101-through hole; 102-key slot; 2-fastening screw; 3-pulling cable; 4-operating hook; 5-connecting piece. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments disclosed in this disclosure can be combined, separated, interchanged and / or rearranged with each other. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0030] 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.

[0031] Example 1

[0032] A specific embodiment of the utility model is as follows Figure 1-3 As shown, a patella fracture fixation device is disclosed, comprising:

[0033] A hollow screw 1 has an external thread at one end and a through hole 101 at the other end, wherein the angle between the through hole 101 and the axial direction of the hollow screw 1 is an acute angle;

[0034] A fastening screw 2, one end of which is inserted into the through hole 101;

[0035] A pulling cable 3 , one end of which is fixedly connected to an end of the fastening screw 2 away from the through hole 101 .

[0036] During implementation, a guide pin is inserted into the inner cavity of the hollow screw 1, and after the hollow screw 1 is guided to reposition the fractured patella, the guide pin is removed; then the fastening screw 2 is inserted into the through hole 101 of the hollow screw 1; and then the pulling cable 3 cooperates with the hollow screw 1 to fix the patella.

[0037] Compared with the prior art, the patellar fracture fixation device provided in this embodiment, through the combined design structure of hollow screws, fastening screws and traction cables, does not require secondary screw insertion after one-time installation, will not cause bone loss, and can use hollow screws to guide the positioning of the guide needle, without the need for incision reduction and re-searching for the screw tunnel, thereby improving the success rate and effectiveness of the operation and reducing damage to the patella.

[0038] In some embodiments, the external thread of the hollow screw 1 includes a single-thread or a multi-thread, and the pitch of the external thread is 1mm-2mm, which can not only ensure a good fixation effect, but also reduce the friction with the bone and reduce damage to the bone.

[0039] In this embodiment, an operating hook 4 is further included, and the operating hook 4 is fixedly connected to the other end of the pulling cable 3; the operating hook 4 is curved.

[0040] Specifically, the operating hook 4 is connected to the free end of the pulling cable 3, and is used to drive the pulling cable 3 to pass through the human tissue along the outer contour of the patella to cooperate with the hollow screw 1 to fix the patella; the operating hook 4 has a certain curvature, such as 30°, to facilitate the operator's use.

[0041] In some embodiments, the hollow screw 1, the fastening screw 2, the pulling cable 3 and the operating hook 4 in the patellar fracture fixation device are set to an even number of the same number; for example, there are two of them, and the two pulling cables 3 are connected to one end of the operating hook 4 and are connected to each other through a connector 5; when using two hollow screws 1 for fixation, the pulling cables 3 connecting the two fastening screws 2 are crossed in an eight-shaped shape to achieve fixation in the lateral direction; at this time, the two hollow screws 1 can be pulled by each other through the pulling cables 3 to complete the pressurized fixation of the patella; wherein the pulling cables 3 are tightened and fixed by a restraint; thereby achieving 270° coverage according to the direction of the bone block.

[0042] In some embodiments, one end of the fastening screw 2 is integrally formed with the pulling cable 3; the pulling cable 3 and the fastening screw 2 can form an integrated structure, and after the fastening screw 2 is installed in the hollow screw 1, the pulling cable 3 is prevented from loosening and slipping, and the nail and cable interact with each other, and the stability can be greatly improved.

[0043] In this embodiment, the through hole 101 has an internal thread, and the fastening screw 2 has an external thread matching the internal thread of the through hole 101 .

[0044] Specifically, an external thread matching the internal thread of the through hole 101 is provided on the surface of the fastening screw 2. After the position of the hollow screw 1 is fixed, one end of the fastening screw 2 provided with the external thread is screwed into the through hole 101, so that the pulling cable 3 connected to the other end of the fastening screw 2 is relatively fixed to the hollow screw 1, so as to reposition and fix the patella.

[0045] In this embodiment, the hollow screw 1 has a keyway 102 on its end surface at one end of the through hole 101, which is used to cooperate with a tool to rotate and drive the hollow screw 1 to screw into the patella.

[0046] Specifically, the keyway 102 can be set to a plum blossom shape or a hexagonal shape, and the depth is within the range of 5mm-8mm, so that the tightening tool can be inserted into the keyway 102, and the hollow screw 1 can be screwed into the patella to complete the initial fixation work.

[0047] In this embodiment, the hollow screw 1 has a plurality of through holes 101 , and the angle between each through hole 101 and the axial direction of the hollow screw 1 is an acute angle and is different from each other.

[0048] Specifically, one end of the hollow screw 1 connected to the fastening screw 2 is circumferentially provided with a plurality of through holes 101, and the angle between each through hole 101 and the axial direction of the hollow screw 1 is in the range of 0-45°, so that the fastening screw 2 can adapt to different needs and cooperate with the hollow screw 1 to better fix the patella.

[0049] In this embodiment, one end of the fastening screw 2 connected to the pulling cable 3 is configured as a right prism, and the radial dimension of the right prism is greater than the diameter of the through hole 101 .

[0050] Exemplarily, the end of the fastening screw 2 connected to the pulling cable 3 can be a triangular prism, a quadrangular prism, a pentagonal prism or a hexagonal prism, which is convenient for screwing the fastening screw 2 into the through hole 101 using a tool. At the same time, it can also limit the screw-in depth of the fastening screw 2 to prevent the fastening screw 2 from escaping from the through hole 101.

[0051] In some embodiments, the hollow screw 1 has a radial dimension at one end of the through hole 101 that is larger than the diameter of the hollow screw 1. That is, the end of the hollow screw 1 that applies pressure has a larger radial dimension, which facilitates screwing the hollow screw 1 into the patella using a tool.

[0052] In some embodiments, the outer surface of one end of the through hole 101 of the hollow screw 1 is provided with external threads, that is, both ends of the hollow screw 1 have external threads, so that both ends of the hollow screw 1 provide a better fixation effect on the patella.

[0053] In this embodiment, the pulling cable 3 is formed by a plurality of steel cables being wound in a spiral manner.

[0054] Specifically, the structure in which multiple steel cables are spirally wound can prevent the steel cables from loosening and separating. Setting a steel cable with a larger cross-sectional area as a structure composed of multiple steel cables with smaller cross-sectional areas can also improve the softness of the pulling cable 3.

[0055] In some embodiments, the materials of the hollow screw 1, the fastening screw 2, the pulling cable 3 and the operating hook 4 may also include absorbable materials, for example, absorbable polylactic acid composite materials and absorbable polycaprolactone and other materials with certain hardness, plasticity and degradability, which can achieve a good fixation effect after the operation is completed while reducing adverse effects on the human body.

[0056] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only the specific implementation method of the utility model and is not used to limit the protection scope of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A patellar fracture fixation device, characterized in that: include: A hollow screw (1) having an external thread at one end and a through hole (101) at the other end, wherein the angle between the through hole (101) and the axial direction of the hollow screw (1) is an acute angle; a fastening screw (2), one end of the fastening screw (2) being inserted into the through hole (101); A pulling cable (3), one end of which is fixedly connected to an end of the fastening screw (2) away from the through hole (101); the end of the fastening screw (2) connected to the pulling cable (3) is configured as a right prism, and the radial dimension of the right prism is greater than the diameter of the through hole (101).

2. The patella fracture fixation device according to claim 1, characterized in that: It also comprises an operating hook (4), wherein the operating hook (4) is fixedly connected to the other end of the pulling cable (3).

3. The patella fracture fixation device according to claim 2, characterized in that: The operating hook (4) is in a curved shape.

4. The patella fracture fixation device according to claim 1, characterized in that: The through hole (101) has an internal thread, and the fastening screw (2) has an external thread matching the internal thread of the through hole (101).

5. The patella fracture fixation device according to claim 1, characterized in that: The hollow screw (1) has a keyway (102) on its end surface at one end of the through hole (101), which is used to cooperate with a tool to rotate and drive the hollow screw (1) to be screwed into the patella.

6. The patella fracture fixation device according to claim 1, characterized in that: The hollow screw (1) has a plurality of through holes (101), and the angle between each through hole (101) and the axial direction of the hollow screw (1) is an acute angle and is different from each other.

7. The patella fracture fixation device according to claim 1, characterized in that: The hollow screw (1) has a radial dimension at one end of the through hole (101) that is greater than the diameter of the hollow screw (1).

8. The patella fracture fixation device according to claim 1, characterized in that: The hollow screw (1) has an outer surface at one end of the through hole (101) provided with an external thread.

9. The patella fracture fixation device according to claim 1, characterized in that: The pulling cable (3) is formed by spirally winding a plurality of steel cables.

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