Connecting rod for spinal posterior internal fixation system

Abstract

The utility model relates to the technical field of orthopedic internal fixers, and particularly discloses a connecting rod for a spinal posterior internal fixation system, which comprises a rod body, and the cross section of the rod body is in a major arc shape, so that a plane part is formed on the side surface of the rod body. In the spine posterior internal fixation operation, the screw plug abuts against the plane portion of the connecting rod, the connecting rod does not generate angular displacement in the U-shaped groove and does not generate axial displacement easily, and the overall stability of a pedicle screw-rod system is remarkably improved; the main body part of the connecting rod still tends to be cylindrical, so that the advantages of high strength, flexibility in installation, capability of pre-bending and the like of a round rod are reserved, and the connecting rod can be particularly matched with an existing pedicle screw for use; due to the fact that the size of the plane portion and the opposite side of the plane portion is smaller than the diameter of the arc portion, on the premise that the connecting rod is stably fixed, the length of the screw cap can be properly reduced, the size of the pedicle screw rod system in the front-back direction after installation is reduced, operation wounds can be reduced, and postoperative recovery is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of orthopedic internal fixators, and in particular to a connecting rod used in posterior spinal internal fixation. Background Art

[0002] Posterior spinal fixation is generally performed by implanting a pedicle screw-rod system in the posterior spine to restore the originally abnormally positioned spine to its normal position, thereby treating spinal diseases. This surgery is mostly used to treat severe scoliosis, kyphosis and other diseases. It can also be used for surgical treatment of spinal tumors, fractures and other diseases.

[0003] At present, the commonly used pedicle screw-rod system in clinical practice is mainly composed of pedicle screws, screw plugs and connecting rods, such as Figure 1 As shown, a nail cap 2 is provided at the rear end of the pedicle screw 1, and a U-shaped groove 5 is provided on the nail cap 2. The nail cap 2 and the screw plug 4 can be threadedly matched to lock the connecting rod in the U-shaped groove, thereby realizing the fixed connection between the pedicle screw and the connecting rod. The connecting rod is cylindrical, so it is also called round rod 3, which highlights certain shortcomings in the application of internal fixation: on the one hand, the round rod 3 is cylindrical and has a smooth surface. The pedicle screw 1 is fixedly connected with the round rod 3 by means of the screw plug 4, which is difficult to maintain stability for a long time, and is prone to rotation angle displacement during the postoperative recovery period, affecting the treatment effect. If the looseness is serious, it needs to be treated again; on the other hand, the nail cap 2 and the screw plug 4 are threadedly matched to lock the round rod 3. In order to ensure sufficient locking force, the nail cap 2 and the screw plug 4 need to have a sufficient matching length, so that the constructed pedicle screw rod system is larger in the front-to-back direction, which increases the surgical trauma to a certain extent and is not conducive to postoperative recovery. Summary of the invention

[0004] In order to overcome the aforementioned technical problems existing in the prior art, the technical purpose of the utility model is to provide a connecting rod for a posterior spinal internal fixation system which can be used in conjunction with the existing pedicle screws to significantly improve the stability of the pedicle screw-rod system and reduce injury trauma to a certain extent.

[0005] In order to achieve the above technical purpose, the utility model adopts the following technical solutions:

[0006] A connecting rod for a posterior spinal internal fixation system comprises a rod body, wherein the cross section of the rod body is in a major arc shape, so that a plane portion is formed on the side of the rod body.

[0007] Furthermore, positioning holes are provided at both ends of the rod body.

[0008] Furthermore, the rod body is made of titanium alloy material.

[0009] Compared with the prior art, the connecting rod for the posterior spinal internal fixation system disclosed in the utility model has the following technical effects:

[0010] Although the connecting rod for the posterior spinal internal fixation system has a flat portion, its main body is still cylindrical, retaining the advantages of a round rod such as high strength and flexible installation, and in particular, can be used in conjunction with existing pedicle screws like a round rod.

[0011] In posterior spinal fixation, when connecting the connecting rod and the pedicle screw, the angle of the connecting rod in the U-shaped groove is adjusted so that the screw plug contacts the flat part thereof, so that the connecting rod does not undergo angular displacement. At the same time, the flat part increases the contact area between the connecting rod and the nut, making it difficult for the connecting rod to undergo axial displacement, thereby significantly improving the overall stability of the pedicle screw-rod system.

[0012] The connecting rod used in the posterior spinal internal fixation system has a special shape. The size of the flat part and its opposite side is smaller than the diameter of the arc part. When the connecting rod is connected to the pedicle screw, the screw plug and the flat part abut against each other. Based on this layout, the length of the screw cap can be appropriately reduced, thereby reducing the size of the pedicle screw-rod system in the anterior-posterior direction after installation, which can reduce surgical trauma to a certain extent and facilitate postoperative recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the matching state of the round rod and the pedicle screw.

[0014] Figure 2 It is a structural schematic diagram of the connecting rod in the utility model.

[0015] Figure 3 It is a schematic diagram of the matching state of the connecting rod and the pedicle screw in the utility model.

[0016] Figure 4 The figure is a size comparison diagram of the connecting rod and the original round rod in the utility model after being connected with the pedicle screw respectively.

[0017] In the figure, 1, pedicle screw, 2, screw cap, 3, round rod, 4, screw plug, 5, U-shaped groove, 6, rod body, 7, positioning hole, 8, flat part. DETAILED DESCRIPTION

[0018] In the drawings of the specification, Figure 2 The specific structure of the connecting rod for the posterior spinal internal fixation system is shown. Figure 3 The matching mode of the connecting rod and the pedicle screw is shown.

[0019] See also Figure 2 As shown, the connecting rod for the posterior spinal internal fixation system disclosed in the utility model includes a rod body 6, which is made of titanium alloy material. The cross section of the rod body 6 is in a major arc shape, so that a flat portion 8 is formed on the side of the rod body 6.

[0020] See also Figure 3 As shown, in the posterior spinal fixation, when connecting the connecting rod and the pedicle screw 1, the connecting rod is placed in the U-shaped groove 5 and the angle is adjusted so that the flat portion 8 of the connecting rod is opposite to the screw plug 4, thereby ensuring that the connecting rod will not undergo angular displacement after the screw plug 4 is tightened. At the same time, the flat portion 8 increases the contact area between the connecting rod and the screw plug 4, making it difficult for the connecting rod to undergo axial displacement, thereby significantly improving the overall stability of the pedicle screw 1 rod system.

[0021] Although the connecting rod for the posterior spinal fixation system has a flat portion 8, its main body is still cylindrical, retaining the advantages of a round rod such as high strength, flexible installation and pre-bending. In particular, it can be used in conjunction with the existing pedicle screw 1 like a round rod.

[0022] See also Figure 4 As shown, the connecting rod used in the present posterior spinal internal fixation system has a special shape, the dimension D1 of the flat portion 8 and its opposite side is smaller than the diameter R1 of the arc portion, and the screw plug 4 abuts against the flat portion 8 when the connecting rod is connected to the pedicle screw 1. Based on this layout, compared with the existing round rod 3 placement method, while ensuring stable fixation of the connecting rod, the length of the nail cap 2 can be appropriately reduced, thereby reducing the size of the pedicle screw 1 rod system in the anterior-posterior direction after installation, which can reduce surgical trauma to a certain extent and facilitate postoperative recovery.

[0023] like Figure 2 , 3 As shown, in the posterior spinal fixation surgery, the planar portion 8 of the connecting rod is directly opposite to the screw plug 4, which is the basis for achieving the aforementioned technical effect. In order to facilitate the adjustment of the angle of the connecting rod during the operation, positioning holes 7 are respectively provided at both ends of the rod body 6, and the positioning holes 7 are preferably opened on the planar portion 8; thus, after the connecting rod is placed in the U-shaped groove 5, a tool such as a probe is inserted into the positioning hole 7, and the connecting rod can be conveniently rotated and adjusted.

Claims

1. A connecting rod for a posterior spinal internal fixation system, comprising a rod body, characterized in that: The cross section of the rod body is in the shape of a major arc, so that a flat surface is formed on the side of the rod body; positioning holes are provided at both ends of the rod body.

2. The connecting rod for the posterior spinal internal fixation system according to claim 1, characterized in that: The rod body is made of titanium alloy material.

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