JP2022053563A - Percutaneous full endoscope cage insertion assisting tool - Google Patents

Abstract

To provide an elongate tool capable of being inserted into an external cylinder of a percutaneous full endoscope, the tool having a structure whose rigidity is also secured, the tool assisting insertion of a cage between centra through a Kambin triangle while securely protecting nerves.SOLUTION: Each of two tools has an L-shaped sectional form having one side whose external surface has a partially circular shape incrassated outwardly and has a continuous uneven surface processed for slip resistance on the hand side. With the two tools combined so that depressions of L-shaped sectional forms face each other, handling of cages larger than an external cylinder and having various sizes is enabled.SELECTED DRAWING: Figure 5

Description

The present invention relates to an instrument for assisting cage insertion, which is used in lumbar interbody fusion surgery using a percutaneous total endoscope.

There is a method using a percutaneous total endoscope for the spine in minimally invasive spinal surgery. The percutaneous total endoscope 900 is a long and narrow cylinder with an outer diameter of about 6 mm to less than 7 mm, and the main body part 901, which is the part to be inserted into the body as shown in FIGS. 1 and 2, is a lens barrel 902 in it. The light source path 903, the perfusion channel 904, and the working lumen 905 are integrally configured. A cylindrical outer cylinder 906 having an outer diameter of about 7 mm to 8 mm is inserted into the body through the skin incision portion S, the main body portion 901 is inserted into the cylindrical outer cylinder 906, and water is perfused from the outside to the perfusion channel 904 to wash the object. , The image from the connected camera is projected on a monitor and mirrored, and the vertebral bone L and the like are operated with an instrument such as a forceps or a drill 907 inserted into the working lumen 905.

Lumbar intervertebral fusion surgery, which is performed for lumbar spondylolisthesis and lumbar disc degeneration, is generally surgery for interbody bone grafting and posterior screw fixation, as shown in Fig. 3. In intervertebral bone grafting, most of the intervertebral disc of the intervertebral IB is excised, a box-shaped spacer called cage 910 (Fig. 4) is inserted into the space, and the cage is filled with bone tissue for transplantation. In addition, bone grafts are also performed around the cage. The purpose of inserting the cage is to prevent the gap between the intervertebral disc-removed intervertebral discs from collapsing and to prevent the bone tissue transplanted there from being crushed, and to stabilize the intervertebral discs for bone fusion. It is to make the situation favorable to. Posterior screw fixation is to immobilize adjacent vertebral bodies with a screw 911 inserted into the vertebral body B from the back surface and a bar 912 attached to the screw 911. Lumbar interbody fusion relieves the symptoms by bone fusion between the vertebral bodies.

Conventionally, in intervertebral bone grafting, the vertebra L behind the nerve is excised to expose the site called the Kambin triangle (see FIG. 8), which is the site surrounded by the cranio-caudal vertebral body B and the nerve N. After that, intervertebral disc excision and cage insertion were performed via that. This operation around the nerve causes postoperative complications due to nerve injury and hematoma, and there is a problem that the surgical invasion becomes large. Therefore, by using a percutaneous total endoscope, since the instrument has a small diameter, it is possible to safely reach the Kambin triangle without performing a large osteotomy, and the intervertebral disc can be excised. However, there is a problem at the stage of inserting the cage after that. Since the commonly used cage is larger than the outer cylinder, the cage cannot be inserted through the outer cylinder. If the cage is inserted after removing the outer cylinder, there is a risk that the cage will hit the nerve and cause injury. Therefore, in order to enable the safe insertion of the cage percutaneously, we developed the percutaneous interbody fusion PELIF method. This instrument is a form of cage insertion assisting instrument used in the PELIF method.

There are various cage sizes, and the appropriate size varies depending on the patient, but it is desirable to insert a cage as large as possible. On the other hand, the space between the vertebral bodies is often narrow. When inserting the cage, a strong force is applied to the cage insertion assisting device because it is driven with a hammer to widen the narrowing space between the vertebral bodies. Rigidity is also required so that plastic deformation does not occur.

JP-A-2020-22553

Title of the paper "Results of percutaneous lumbar interbody fusion (PELIF)" Journal of Spine Research Vol. 8, No. 7, Page1317-1320. 2017

The cage insertion assist device is an elongated device that can be inserted into the outer cylinder of a percutaneous total endoscope, yet has a structure that ensures rigidity, and the cage is passed through the Kambin triangle while reliably protecting the nerves. It must be an instrument that can be inserted between the vertebral bodies. It is larger than the outer cylinder and can accommodate cages of various sizes.

The cage insertion assisting devices 100 and 110 of the present invention are elongated devices that can be inserted into an outer cylinder for a percutaneous total endoscope, and the cross-sectional shape is L-shaped and the outer surface on one side thereof is a partial circular shape. It is thickened toward you. On the outer surface of the hand side P of the cage insertion assisting device, there is a continuous uneven surface processed to prevent slipping. This cage insertion assist device (large) 100 is the same type as the slightly smaller size (small) 110, and is used by being arranged in a "" shape.

In the operation, the outer tube 906 is inserted into the intervertebral body IB from the posterolateral side of the lumbar region via the Kambin triangle, a percutaneous total endoscope is inserted into the vertebral body, and the intervertebral disc is excised, as shown in FIG. Insert the large and small pairs of the cage insertion assisting devices 100 and 110 into the outer cylinder in a "" -shaped arrangement, and remove the outer cylinder while pressing the tip with a stick so that it is inside the intervertebral disc. do. As shown in FIG. 7, the outer surface of the cage insertion assisting device (large) is directed to the outside of the head, and the two sides of the outside of the head of the cage 910 are applied to the two sides of the inner surface. The cage insertion assisting device (small) should also be placed face-to-face with the cage. Grasp the cage insertion aid by hand and push the cage with a push rod. The cage is guided and inserted between the vertebral bodies while sliding on the inner surface of the cage insertion assisting device.

As shown in FIG. 8, the nerve N runs on the cranial side of the Kambin triangle, which is the cage insertion part, and the cage insertion assisting device 100 covers the cranial lateral corner of the cage 910 to separate the nerves. It is possible to avoid scratch damage to nerves due to the corners of the cage when the cage is inserted. And even if the cage is large in size, it can accommodate various cage sizes because it is surrounded by instruments with a "" -shaped arrangement and is guided between the vertebral bodies without coming off.

In addition, as shown in FIG. 8, the conditions required for the cage insertion assist device are that the cranio-caudal side of the interbody IB is almost flat, and the outer surfaces of the cranial and caudal sides of the cage insertion assist device are flat. There is. As shown in Fig. 4, since the cage has an almost square pillar shape, the inner surface of the cage insertion assisting device must be L-shaped to cover and fit the corners of the cage. In addition, the ability to insert into the outer tube for a percutaneous total endoscope is necessary for the safe insertion of cage insertion aids. The two sides of the L-shape, one on the head side and the other on the outside, should be as long as possible to cover the nerves with a margin, but on the other hand, it is desirable to have as much thickness as possible to ensure rigidity. The above shape is the best to satisfy the above conditions.

When driving the cage with a push rod, if the cage insertion assisting device is dragged along with the cage and pushed into the intervertebral space, the cage insertion assisting device cannot be removed, but the P outer surface on the hand side of the cage insertion assisting device is continuous. The uneven surface increases the friction with the gripped hand and makes it difficult for the cage insertion aid to be pulled in.

Part of a percutaneous total endoscope and outer tube during posterior spinal surgery. Percutaneous total endoscope and perspective view of the tip of the outer cylinder. Schematic diagram of the side of lumbar interbody fusion. Perspective view of the cage. Rear view of the cage insertion assisting device when it is inserted into the outer cylinder by combining the size. Large and small perspective views of cage insertion aids. Rear view with cage insertion assisting device when inserting cage. Diagram of the lumbar spine and surrounding tissues when the cage is inserted (viewed from behind in the insertion direction). Perspective view of cage insertion aid and remover.

An embodiment of the present invention will be described with reference to FIGS. 5 to 9. The cage insertion assist device (large) 100 is an elongated device that can be inserted into the outer cylinder 906 for percutaneous total endoscopy, and has a total length of about 200 mm, its cross-sectional shape is L-shaped, and its two sides are long. It is about 4 mm and about 5 mm, respectively, and the outer surface of one of the two sides, whichever is shorter, has a partial circular shape and is thickened outward.
The same type as above, but the two sides of the cross section are slightly shorter, and the total length is the same. The cage insertion assist device (small) 110 is paired.
The outer surface of the hand side P of the cage insertion assisting devices 100 and 110 has a continuous uneven surface processed to prevent slipping. There are holes 101 (hidden and invisible in FIG. 9) and 111 on the hand side of the cage insertion assisting device, and when the cage insertion assisting device is removed, the removal device 120 with the hook 121 is used to fill the holes 101 and 111. Hook it and hit it with a hammer to remove it.

S Skin incision L Vertebra dorsal B Vertebra IB Intervertebral CE Cranial CA Caudal ME Medial LA Lateral D Tiptic P Hand N Nerve

Claims (1)

An instrument intended to assist in inserting a cage in lumbar interbody fusion. It is an elongated instrument that can be inserted into the outer cylinder for percutaneous total endoscopy, and its cross-sectional shape is L-shaped on one side. The outer surface is partially circular and thickened outward.
The outer surface on the hand side of this device has a continuous uneven surface processed to prevent slipping.
Another cage insertion assisting instrument is that it can surround the cage by using a pair of instruments of similar shape that are rotated 180 degrees around the long axis.

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