JP2023178659A - Device for in-vivo implantation - Google Patents

Abstract

To provide a device for in-vivo implantation that can be secured with sufficient firmness between bones.SOLUTION: A device 100 for in-vivo implantation to be sandwiched between two opposing bones comprises an elongated main body part 10 having a first contact surface 21 brought into contact with one bone, a second contact surface formed back to back with the first contact surface and brought into contact with the other bone, and a hole portion 23 penetrating from the first contact surface to the second contact surface, where at least one of the first and second contact surfaces is provided such that multiple first teeth 1 are arranged along a longitudinal direction L of the main body part on one side across the hole portion, such that multiple second teeth 2 are arranged along the longitudinal direction L on the other side, and such that a width direction T1 in which the first teeth extend and a width direction T2 in which the second teeth extend are the in-plane direction of the first or second contact surface and are inclined relative to a lateral direction W, which is a direction perpendicular to the longitudinal direction L.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to an in-vivo implantable device that is inserted between opposing bones.

BACKGROUND ART Conventionally, in-vivo implantation devices that are inserted between opposing bones have been known. This type of in-vivo implantable device was fixed to the bone by the tissue emerging from the bone penetrating and bonding to a porous material. For this reason, improved bioimplantable devices have been proposed that utilize significant amounts of porous material but remain cost-effective and maintain the strength required for bioimplantable devices ( For example, see Patent Document 1).

Japanese Patent Application Publication No. 2016-135243

However, in the conventional implantable device described above, since it has a cavity formed in the center so as to pass through the upper surface and the lower surface, the implantable device can be placed between opposing bones. It was difficult to securely fix it between the two. A bone growth promoting substance can be placed in the cavity, but the larger the cavity, the smaller the contact area with the bone, and the lower the fixation force of the in-vivo implantable device.

An object of the present invention is to solve the problems of the conventional techniques described above, and to create a material that can be firmly fixed between bones even if it has cavities or holes that reduce the contact surface with bones. The purpose is to provide devices for implantation in the body.

The present invention provides an in-vivo implantable device to be inserted between opposing bones, including a first contact surface that contacts one bone, and a second contact surface that is formed back to back with the first contact surface. and a hole penetrating from the first contact surface to the second contact surface. At least one of the contact surface and the second contact surface is provided with a plurality of first teeth arranged along the longitudinal direction of the main body on one side of the hole, and , a plurality of second teeth are provided on the other side so as to be arranged along the longitudinal direction, and a width direction in which the first teeth extend and a width direction in which the second teeth extend. is inclined with respect to a lateral direction that is an in-plane direction of the first contact surface or the second contact surface and a direction perpendicular to the longitudinal direction.

In this case, the main body portion has one end in the longitudinal direction formed in a wedge shape, and the first tooth and the second tooth are provided so as to be inclined so that the hole side is closer to the one end. It may be. The first tooth and the second tooth may be provided so as to have an inclination of 10 degrees or more and 25 degrees or less with respect to the lateral direction. The first tooth and the second tooth may be provided so as to have an inclination of 10 degrees or more and 20 degrees or less with respect to the lateral direction. The first tooth and the second tooth may be provided so as to have an inclination of 7.5 degrees or more and 17.5 degrees or less with respect to the lateral direction. The first tooth and the second tooth may be provided so as to have an inclination of 15 degrees with respect to the lateral direction. The first contact surface or the second contact surface is provided such that the third tooth extending in the lateral direction is adjacent to the first tooth and the second tooth, The distance between the third tooth, the first tooth, and the second tooth may be larger at a position closer to the hole.

According to the present invention, it is possible to provide an in-vivo implantation device that can be sufficiently firmly fixed between bones even if it has a cavity or a hole that reduces the contact surface with bones.

FIG. 1 shows a perspective view of an in-vivo implantation device according to an embodiment of the present invention. A schematic diagram showing a state in which an in-vivo implantation device is inserted between vertebrae is shown. FIG. 2 shows a top view of the in-vivo implantation device. FIG. 2 shows a side view of the in-vivo implantation device. FIG. 6 shows a hexagonal view of an in-vivo implantation device in which the angle of the first tooth and the second tooth with respect to the lateral direction is 15°. FIG. 6 is a hexagonal view in which only characteristic tooth portions of the in-vivo implantable device are shown in solid lines, in which the angle of the first tooth and the second tooth with respect to the lateral direction is 15°. Figure 2 schematically shows a longitudinal pull-out test. A lateral pull-out test is schematically shown. 1 shows a top view and a side view of a conventional in-vivo implantable device. The hexagonal view of the in-vivo implantation device according to a modification in which the angle of the first tooth and the second tooth with respect to the lateral direction is 10° is shown. The hexagonal view of the in-vivo implantation device according to a modified example in which the angle of the first tooth and the second tooth with respect to the lateral direction is 20° is shown.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a perspective view of an in-vivo implantable device according to an embodiment of the present invention, and FIG. 2 shows a schematic diagram showing how the in-vivo implantable device is inserted between vertebrae. , FIG. 3 shows a top view of the in-vivo implantable device, FIG. 4 shows a side view of the in-vivo implantable device, and FIG. 5 shows the relationship between the first tooth and the second tooth in the lateral direction. FIG. 6 shows a hexagonal view of an in-vivo implantable device in which the angle is 15°, and FIG. A hexagonal view showing only the typical tooth portions with solid lines is shown.

As shown in FIG. 1, the in-vivo implantation device 100 according to the present embodiment is formed into a substantially rectangular parallelepiped and has a first abutting surface 21 and a second abutting surface 22, which face each other in the vertebrae. This is a spinal implant for interposing a first abutting surface 21 and a second abutting surface 22 between bones so that they are in contact with the bones and are sandwiched therebetween. When inserting the in-vivo implantable device 100 between the vertebrae, as shown in FIG. The instrument 101 is removed in this state.

As shown in FIG. 3, the in-vivo implantable device 100 has an elongated frame (body portion) 10 and a base material 20 that is a fusion portion. The frame 10 and the base material 20 are integrally molded using titanium or a titanium alloy, and are manufactured using a 3D printer.

The frame 10 is formed solid, has a shape in which two side walls 11 and 12, a rear wall 13, and a front wall 14 are combined into a rectangular shape, and a base material 20 is formed inside. .

The base material 20 is exposed from the first contact surface 21 and the second contact surface 22 (see FIG. 1). The base material 20 is provided in a substantially rectangular shape so that its outer periphery is covered by the front wall 14, side walls 11, 12, and rear wall 13 of the frame 10. The base material 20 is made of the same material as the frame 10 and is integrally formed into a net shape.

The pair of side walls 11 and 12 are each formed to have a flat surface and are positioned to face each other. As shown in FIG. 4, these side walls 11 and 12 have an opening 11a having an oval shape extending in the longitudinal direction L from the front wall 14 side to the rear wall 13 side so as to be located in the center of the longitudinal direction L. , 12a are formed.

A flat rear wall 13 is located at the rear of the side walls 11, 12. This rear wall 13 may be formed with a screw hole for attaching an instrument 101 (see FIG. 2).

A front wall 14 provided at the front of the side walls 11 and 12 is formed into a wedge shape projecting in the longitudinal direction L.

As shown in FIG. 3, the first contact surface 21 and the second contact surface 22 have a plurality of first teeth 1 on one side with the hole 23 interposed therebetween along the longitudinal direction L of the frame 10. A plurality of second teeth 2 are provided so as to be arranged along the longitudinal direction L on the other side. The width direction T1 in which the first tooth 1 extends from the hole 23 toward the side wall 11 is in the in-plane direction of the first contact surface 21 and in the lateral direction W, which is a direction perpendicular to the longitudinal direction L. It is tilted by an angle θ1. Similarly, the width direction T2 in which the second tooth 2 extends from the hole 23 toward the side wall 12 is the in-plane direction of the second contact surface 22 and the lateral direction perpendicular to the longitudinal direction L. It is inclined at an angle θ2 with respect to the direction W. In this embodiment, the angle θ1 of the first tooth 1 and the angle θ2 of the second tooth 2 are the same in magnitude. These first teeth 1 and second teeth 2 are provided so as to be inclined so that the closer to the hole 23 the closer the front wall 14 is. In addition, in this embodiment, the angle θ1 of the first tooth 1 and the angle θ2 of the second tooth 2 are 15°.

As shown in FIG. 5, the in-vivo implant device 100 according to the present embodiment preferably has an overall width in the lateral direction W (see FIG. 1) of 6 mm or more and 12 mm or less, and preferably 7 mm or more and 11 mm or less. is more preferable, more preferably 8 mm or more and 10 mm or less, and in this embodiment, the overall width in the lateral direction W is 9 mm. When the overall width is within such a preferable range, the in-vivo implantable device 100 can be fixed sufficiently firmly between bones.

As shown in FIG. 5, the in-vivo implant device 100 according to the present embodiment preferably has an overall length in the longitudinal direction L (see FIG. 1) of 17 mm or more and 29 mm or less, and preferably 19 mm or more and 27 mm or less. More preferably, the length is 21 mm or more and 25 mm or less, and in this embodiment, the overall length in the longitudinal direction L is 23 mm. When the length is within such a preferable range, the in-vivo implantable device 100 can be fixed sufficiently firmly between bones.

As shown in FIG. 6, the heights of the plurality of first teeth 1 and the plurality of second teeth 2 are equal to the height of the first contact surface 21 and the second contact surface 21 in the height direction H (see FIG. 1). It is preferably 0.2 mm or more and 0.8 mm or less, more preferably 0.3 mm or more and 0.7 mm or less, and even more preferably 0.4 mm or more and 0.6 mm or less, based on the contact surface 22. In this embodiment, this height is 0.5 mm. When the height is within such a preferable range, the in-vivo implantable device 100 can be fixed sufficiently firmly between bones.

The plurality of first teeth 1 and the plurality of second teeth 2 each have a distance (tooth pitch) from the apex of one tooth to the apex of the adjacent tooth in the longitudinal direction L (see FIG. 1). It is preferably 1.0 mm or more and 3.0 mm or less. This pitch is more preferably 1.5 mm or more and 2.3 mm or less, and even more preferably 1.8 mm or more and 2.0 mm or less. In this embodiment, this pitch is 1.9 mm. When the distance is within such a preferable range, the in-vivo implantable device 100 can be fixed sufficiently firmly between the bones.

As shown in FIG. 5, the in-vivo implant device 100 according to the present embodiment has a width of the first tooth 1 and the second tooth 2 in the lateral direction W (see FIG. 1) of 1.6 mm or more. It is preferably .4 mm or less, more preferably 1.7 mm or more and 2.3 mm or less, even more preferably 1.8 mm or more and 2.2 mm or less, and 1.9 mm or more and 2.1 mm or less. is even more preferable, and in this embodiment, it is 2.0 mm. The in-vivo implantation device 100 according to the present embodiment has the advantage that even if the width of the first tooth 1 and the second tooth 2 in the lateral direction W is within such a range, the first tooth 1 and the second tooth 2 Because the teeth 2 are angled as described above, it is possible to secure the tooth 2 sufficiently firmly between the bones.

In the in-vivo implant device 100 according to the present embodiment, as shown in FIG. 5, the width of the hole 23 in the lateral direction W (see FIG. 1) is preferably 4.2 mm or more and 5.8 mm or less. , more preferably 4.4 mm or more and 5.6 mm or less, further preferably 4.6 mm or more and 5.4 mm or less, even more preferably 4.8 mm or more and 5.2 mm or less, and this embodiment , it is 5.0 mm. In the in-vivo implantation device 100 according to the present embodiment, even if the width of the hole 23 in the lateral direction W is within such a range, the first tooth 1 and the second tooth 2 have the above-mentioned shape. Due to the angularity, etc., it is possible to secure the bones sufficiently firmly between the bones.

In the in-vivo implant device 100 according to the present embodiment, as shown in FIG. 5, the length of the hole 23 in the longitudinal direction L (see FIG. 1) is preferably 8 mm or more and 16 mm or less, and 9 mm or more. It is more preferably 15 mm or less, even more preferably 10 mm or more and 14 mm or less, even more preferably 11 mm or more and 13 mm or less, and in this embodiment, it is 12 mm. Note that the length of the hole 23 in the longitudinal direction L refers to the longest portion. In the in-vivo implantation device 100 according to the present embodiment, even if the length of the hole 23 in the longitudinal direction L is within such a range, the first tooth 1 and the second tooth 2 have the above-described structure. Due to such an angle, etc., it is possible to fix the bones sufficiently firmly between the bones.

As shown in FIG. 3, on the rear wall 13 side of the first tooth 1 and the second tooth 2, there is a third tooth 3 extending in the lateral direction W. They are provided on the first contact surface 21 and the second contact surface 22 so as to be adjacent to each other. The distance between the third tooth 3, the first tooth 1, and the second tooth 2 increases as the position approaches the hole 23. This allows the in-vivo implantable device 100 to be fixed sufficiently firmly between the devices.

FIG. 7 schematically shows the longitudinal pull-out test, and FIG. 8 schematically shows the transverse pull-out test.
In the pullout test in the longitudinal direction L, as shown in FIG. The maximum load (N) was measured. In this test, "Solid rigid polyurethane foam 15 pcf" (material: polyurethane foam, Grade 15 based on ASTM F1839) manufactured by Soborn Co., Ltd. was used as the simulated bone, and the in-vivo implantation device 100 pcf was used with a pressing load of 100 N. The upper simulated bone was pressed in the direction shown by arrow A so as to sandwich it. In the in-vivo implantation device 100, the shaft 32 passed through the opening 11a of the side wall 11 and the opening 12a of the side wall 12 is pulled out with a wire 33 in the longitudinal direction L as shown by arrow B. The drawing speed is 10 mm/min.

In the pull-out test in the longitudinal direction L, the angles θ1 and θ2 of the first tooth 1 and the second tooth 2 tilted with respect to the lateral direction W are the same, and the angles θ1 and θ2 are set to 0 degrees, 5 degrees, and 10 degrees. The average maximum pullout load (N) was measured when the load was changed to 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, and 40 degrees. A conventional product in which the tooth angle is 0 degrees and the hole is smaller than the in-vivo implant device 100 of this embodiment (therefore, the tooth width is larger than the in-vivo implant device 100 of this embodiment) A similar test was also conducted for Conventional products are indicated as "conventional" in the table below. The structure of the conventional product is shown in Figure 9.

The measurement results of the pull-out test in the longitudinal direction L are shown in Table 1. In this table, only the angles θ1 and θ2 of 15 degrees were measured five times, and the other angles θ1 and θ2 were measured four times.

In the pullout test in the lateral direction W, as shown in FIG. The maximum load (N) was measured. This test was basically conducted based on ASTM F-04.25.02.02, with the exception of changes such as changing the pulling direction to the rear instead of the front. In this test, "Solid rigid polyurethane foam 15 pcf" (material: polyurethane foam, Grade 15 based on ASTM F1839) manufactured by Soborn Corporation was used as the simulated bone, and the in-vivo implantation device 100 pcf was used with a pressing load of 100 N. The upper simulated bone was pressed in the direction shown by arrow A so as to sandwich it. The device 100 for implantation in a living body has a T-shaped member 34 in which a vertical bar 34a and a horizontal bar 34b are integrally assembled in a T-shape. 12 opening 12a (see FIG. 4), the horizontal bar 34b is brought into contact with the side wall 12 from the outside, and the T-shaped member 34 is pulled out in the lateral direction W as shown by arrow C with a wire 35. The drawing speed at this time was 10 mm/min.

In the pullout test in the lateral direction W, the angles θ1 and θ2 of the first tooth 1 and the second tooth 2 tilted with respect to the lateral direction W are the same, and the angles θ1 and θ2 are set to 0 degrees, 5 degrees, and 10 degrees. The average maximum pullout load (N) was measured when the load was changed to 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, and 40 degrees.

The measurement results of the pull-out test in the lateral direction W are shown in Table 2. In this table, all angles θ1 and θ2 were measured four times.

From Tables 1 and 2, the angles θ1 and θ2 of the first tooth 1 and the second tooth 2 with respect to the lateral direction W are preferably 10 degrees or more and 25 degrees or less, more preferably 10 degrees or more and 20 degrees or less. More preferably, it is 7.5 degrees or more and 17.5 degrees or less, and in particular, it is found that 15 degrees is the most preferable because the pull-out load becomes significantly large.

The conventional product has a smaller hole than the in-vivo implantation device 100 of this embodiment, and the teeth are larger than the in-vivo implantation device 100 of this embodiment, so at the same tooth angle of 0 degrees, In both the longitudinal direction L and the lateral direction W, the average maximum pullout load (N) was greater than that of the in-vivo implantable device 100 of this embodiment. However, since conventional products have small pores, they cannot be filled with a large amount or large porous material like the in-vivo implant device 100 of this embodiment, and the pores are relatively large. Although the contact surface is relatively small, the problem of the present invention of exerting a sufficient fixing force against the bone cannot be solved.

The in-vivo implantable device 100 according to the present embodiment has a first abutting surface 21 that abuts one bone positioned to sandwich the in-vivo implantable device 100; An elongated frame 10 having second contact surfaces 22 formed back to back and contacting the other bone, and a hole 23 penetrating from the first contact surface 21 to the second contact surface 22. At least one of the first contact surface 21 and the second contact surface 22 has a plurality of first teeth 1 on one side with the hole 23 interposed therebetween along the longitudinal direction L of the frame 10. A plurality of second teeth 2 are provided so as to be arranged along the longitudinal direction L on the other side, and a plurality of second teeth 2 are provided so as to be arranged along the longitudinal direction L, and the first teeth 1 extend in the width direction T1 and The width direction T2 in which the second tooth 2 extends is an in-plane direction of the first abutting surface 21 or the second abutting surface 22, and is inclined with respect to the lateral direction W. As a result, the in-vivo implantation device 100 has a cavity or a hole that reduces the contact surface with the bone so that the first tooth 1 and the second tooth 2 are difficult to displace with respect to the bone. can also be fixed sufficiently firmly between the bones.

Although the present invention has been described above using the embodiments, the present invention is not limited thereto. For example, in the above embodiment, an in-vivo implantation device is described in which the angle of the first tooth and the second tooth with respect to the lateral direction is 15 degrees, but the present invention is not limited to this. If the device has the same dimensions as the in-vivo implant device 100 according to the above embodiment, and the first tooth and the second tooth are inclined with respect to the lateral direction, for example, as shown in FIG. , the angle of the first tooth and the second tooth with respect to the lateral direction may be 10°, or as shown in FIG. 11, the angle of the first tooth and the second tooth with respect to the lateral direction may be 20°. You can.

W... Lateral direction L... Longitudinal direction T1... Width direction T2... Width direction 1... First tooth 2... Second tooth 3... Third tooth 10... Frame (body part)
DESCRIPTION OF SYMBOLS 11... Side wall 11a... Opening part 12... Side wall 12a... Opening part 13... Rear wall 14... Front wall 20... Base material 21... First contact surface 22... Second contact surface 23... Hole part 30... Simulated bone 31... Simulated bone 32... Shaft 33... Wire 34... T-shaped member 34a... Vertical bar 34b... Horizontal bar 35... Wire 100... In-vivo implantation instrument 101... Instrument

Claims (7)

In an in-vivo implantable device to be inserted between opposing bones,
a first contact surface that contacts one bone;
a second abutting surface formed back to back with the first abutting surface and abutting the other bone;
a hole penetrating from the first contact surface to the second contact surface;
comprising an elongated main body having a
At least one of the first contact surface and the second contact surface is configured such that a plurality of first teeth are arranged along the longitudinal direction of the main body on one side of the hole. and a plurality of second teeth are provided on the other side so as to be arranged along the longitudinal direction,
The width direction in which the first teeth extend and the width direction in which the second teeth extend are in-plane directions of the first contact surface or the second contact surface and the longitudinal direction. An in-vivo implantation device characterized by being inclined with respect to the lateral direction, which is a direction perpendicular to the . The in-vivo implantable device according to claim 1,
The main body portion has one end in the longitudinal direction formed in a wedge shape,
The device for implantation in a living body, wherein the first tooth and the second tooth are provided at an angle so that the hole side is closer to the one end. The in-vivo implantable device according to claim 2,
An instrument for implantation in a living body, wherein the first tooth and the second tooth are provided at an inclination of 10 degrees or more and 25 degrees or less with respect to the lateral direction. The in-vivo implantable device according to claim 3,
The device for implantation in a living body, wherein the first tooth and the second tooth are provided with an inclination of 10 degrees or more and 20 degrees or less with respect to the lateral direction. The in-vivo implantable device according to claim 4,
An in-vivo implantation device, characterized in that the first tooth and the second tooth are provided with an inclination of 7.5 degrees or more and 17.5 degrees or less with respect to the lateral direction. . The in-vivo implantable device according to claim 5,
The device for implantation in a living body, wherein the first tooth and the second tooth are provided at an angle of 15 degrees with respect to the lateral direction. The in-vivo implantable device according to any one of claims 1 to 6,
The first contact surface or the second contact surface is provided such that the third tooth extending in the lateral direction is adjacent to the first tooth and the second tooth, An instrument for implantation in a living body, characterized in that a distance between the third tooth, the first tooth, and the second tooth increases as the position approaches the hole.

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