JPH1033656A - Pyramid fixing member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an artificial pyramid fixing member, by which, at the time of fixing a pyramid at a lesion, a part of whole of a pyramid fixing member is replaced with one's own bone with the passage of time. SOLUTION: This is a pyramid fixing member 11 for fixing a pyramid of a lesion, and the member has a structure which is formed by bio-absorbing material having a bone formation-inducing ability, and obtained by compounding a porous body 3 and a dense body 12. Thus, after operation, while the mechanical strength is held by the dense body, with the passage of time, the porous body is replaced with one's own bone, so that long-term strength can be secured, and as it is not necessary to incise one's won bone, an invasion is low, the safety is high, and it is possible to recover from one's illness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing member used for fixing a diseased vertebral body in a surgical procedure performed for a spinal disease such as a herniated disc or spondylolisthesis.

[0002]

2. Description of the Related Art When fixing a diseased vertebral body from the front of a human body, there are the following three methods for fixing members and methods. A method in which autologous bones in the body, such as the iliac bones, are collected in advance, and the autologous bones are inserted between vertebral bodies and fixed by bone fusion obtained over time after the operation. A method of inserting a bioactive material such as hydroxyapatite (hereinafter, referred to as HAP) or crystallized glass on which HAP crystals are precipitated between vertebral bodies, and fixing the bone by bone fusion obtained over time after the operation. . Although it is biologically inactive, it has excellent compatibility with bone and has high mechanical strength. Insert a metallic material such as titanium or a fixing member made of carbon fiber between the vertebral bodies, and perform mechanical occlusion and treatment. A method in which bone is fixed by close contact of bone over time. When the diseased vertebral body is fixed from the back of the human body, there are a method of pressing the space between the spinous processes with a metal device to fix the diseased vertebral body in a bridge shape, and a method of fixing the vertebral body in a bridge shape with a plate and a screw.

[0003]

Among the above materials, in the method of performing treatment from the front, in the method of using autogenous bone shown in (1), bone for transplantation is collected from the iliac bone or the like, so that normal parts are invaded. This has the disadvantage of adding extra pain to the patient. Furthermore, sufficient strength cannot be obtained for the initial fixation immediately after the operation using the autologous bone alone, so that long-term rest is required, and leaving the bed slowly. HA shown in
The method using an artificial material such as P is less invasive than the above, but has excellent osteoconductivity, but has poor mechanical strength, so it is impossible to use it for a vertebral body that receives a load. . In the method using a structural material for a living body such as titanium or carbon fiber shown in the above, the fixation members themselves have no osteoconductivity, so that when used alone, bone formation is slow, and in order to accelerate bone formation, autogenous bone formation is required. Transplantation must be combined. In addition, in the method performed from behind, there is a possibility that there is a possibility of occurrence of complications in terms of long-term reliability, for example, the screw may move and damage the spinal cord, and the ideal method is I can't say.

The present invention has been made in view of the above-mentioned problems, and uses autogenous bone by giving a part or the whole of a vertebral body fixing member the property of being replaced with autogenous bone over time. It is an object of the present invention to provide an artificial vertebral body fixing member capable of fixing at or above the same level.

[0005]

According to the present invention, there is provided a vertebral body fixing member for fixing a diseased vertebral body, wherein a porous body and a dense body made of a bioabsorbable material having osteoconductive ability are combined. It was a structure.

[0006] With such a configuration, immediately after the treatment, the initial mechanical strength is maintained on the dense body having no pores, and the porous body on which the action of cells related to bone metabolism is susceptible to the passage of time over time. Then, new blood vessels in the pores, resorption of material, formation of bone, etc. occur, and are replaced by autologous bone, which can maintain mechanical strength. In this way, by using the bioresorbable material having osteoconductivity for the vertebral body fixing member, the entire vertebral body fixing member can be replaced with autologous bone which is a bone tissue of a living body.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> An embodiment of the present invention will be described below with reference to the drawings.

(Construction) FIGS. 1 to 3 relate to a first embodiment of the present invention. FIG. 1 is an overall view of a vertebral body fixing member, and FIG. 2 (a) is a state immediately after the treatment, FIG. 2 (b) is an intermediate state after the treatment, FIG. 2 (c) is an explanatory view showing a state after a long time after the treatment, and FIG. It is the whole figure which shows the modification of a body fixing member.

As shown in FIG. 1, a vertebral body fixing member 11 of the first embodiment has a dense body portion 12 and a porous body portion 13 which are fixed in a laminated state. The dense body portion 12 is made of β-tricalcium phosphate (hereinafter, β-tricalcium phosphate), which is a bioabsorbable material having osteoconductive ability.
TCP) and have mechanical strength, but the rate of progress of bone formation and autogenous bone replacement is slow. The porous body portion 13 is a porous body made of β-TCP similarly to the dense body portion 12, and has a high bone formation and autogenous bone replacement progress rate. From this porous part, bone formation and autogenous bone replacement progress early and coalesce with the vertebral body.

(Operation) As shown in FIG. 2, the vertebral body fixing member 11 having the above-described structure is loaded with the load of the vertebral body 14 (vertical direction in FIG. 2) and the vertebral body fixing member 11 is stacked. Figure 2 shows that immediately after the treatment,
As shown in FIG. 2A, the initial strength is maintained in the dense body portion 12, and in the medium term, as shown in FIG.
Then, the autogenous bone replacement proceeds, and the autogenous bone increases the strength.
Further, as time elapses, the replacement of the dense body portion 12 with the autogenous bone progresses, and in the future, as shown in FIG. 2C, the entire vertebral body fixing member 11 becomes the bone tissue of the living body.

(Effect) By using this vertebral body fixing member, vertebral body fixation equivalent to the case of using the autogenous bone can be performed without collecting the autogenous bone.

In this embodiment, the shape and the state of lamination of the vertebral body fixing members have been described with reference to FIG. 1. However, the vertebral body fixing members may be, for example, circular as shown in FIG. 3
As shown in (b), three layers may be used, and further, the dense body 12 and the porous body 13 may have more laminated states or other arbitrary shapes.

Regarding the shape, when performing a vertebral body fixation treatment endoscopically, from the viewpoint of ease of insertion and miniaturization of the instrument to make it less invasive, a shape such as a cylindrical shape or a disc shape is used. It is preferable that

The β-TCP used as the material of the dense body portion 12 and the porous body portion 13 is a calcium phosphate compound which is an inorganic component of bone and has excellent osteoconductivity similarly to the aforementioned HAP. It has excellent bioabsorbability that is not available.

[0015] The β-TCP porous body can be quickly replaced with autologous bone, and the strength of ^the dense body is as follows ^:
Experiments have confirmed that the compression direction is about 1300 kg / cm ² . Generally, the compressive strength required as a vertebral body fixing member is considered to be about 180 kg / cm ^2, so that a dense β-TCP body has sufficient strength.

Further, when a complex is obtained by adding an appropriate amount of HAP to β-TCP, the strength is further improved. For example, β
-When about 10 wt% of HAP is added to TCP, the mechanical strength can be improved by about 20% without affecting the absorbability to the living body. A composite of β-TCP and alumina or silica can also improve the mechanical strength. Therefore, the material of the dense body portion 12 and the porous body portion 13 of the vertebral body fixing member 11 described in the present embodiment can be replaced with the above-described complex, in which case the mechanical strength is further increased. The effect is obtained.

The dense body portion 12 and the porous body portion 13 are provided with bone-inducing BMP (Bone Morphogenetic Protein:
Bone forming factor) and TGF-β (Transforming Growth Fact)
or-β: tissue growth factor) and the like to which an appropriate amount is added, the speed of replacement with autologous bone is further accelerated, and earlier healing becomes possible.

<Second Embodiment> (Configuration) FIG. 4 relates to a second embodiment of the present invention.
(A) is an overall view of a vertebral body fixing member, and (b) is a cross-sectional view of the vertebral body fixing member.

As shown in FIG. 4, the vertebral body fixing member 21 of the second embodiment has a dense body portion 22 and a porous body portion 23 which are fused by a polylactic acid layer 24 in a laminated state. The dense body portion 22 is made of β-TCP, which is a bioabsorbable material having an osteoconductive ability.
The composite containing about 10 wt% of AP, the porous body portion 23 is composed of a composite of porous granules of β-TCP and polylactic acid. Then, a space between the dense body portion 22 and the porous body portion 23 is fused with a polylactic acid layer 24.

(Operation) The operation of the vertebral body fixing member 21 thus configured is the same as that of the first embodiment. Further, since the polylactic acid layer 24 is decomposed and absorbed in the body, it does not affect the human body.

(Effect) The effect of using this vertebral body fixing member is the same as the effect of the first embodiment, except that the polylactic acid layer 24
, The dense body 22 and the porous body 23 can be manufactured in different steps, and can contain different materials. In particular, when a composite body of a dense body and a porous body of ceramics such as calcium phosphate is manufactured integrally, distortion may occur at the interface, and the strength of the dense body portion may be inferior to the strength of the dense body alone. If the dense body and the porous body are manufactured in separate processes, the original strength of the dense body can be maintained.
Therefore, it can be a composite of any composition depending on the purpose of use, for example, to increase the strength of only the dense body portion without deteriorating the biological activity of the porous body, or to reduce the strength of the dense body Thus, the initial mechanical strength and the rate of replacement with autologous bone can be controlled, for example, by improving the biological activity of only the porous body portion without increasing the bioactivity.

The material of the dense body portion 22 and the porous body portion 23 may be composed of only β-TCP as in the first embodiment. Further, if the polylactic acid layer 24 is a biodegradable substance, the effect does not change even if, for example, polyglycol, a copolymer of polylactic acid and polyglycolic acid, collagen, chitin, or the like is used.

<Third Embodiment> (Configuration) FIG. 5 relates to a third embodiment of the present invention.
5A is an overall view of a vertebral body fixing member, FIG. 5B is a front view of the vertebral body fixing member, and FIG. 5C is a side view of the vertebral body fixing member.

As shown in FIG. 5, the vertebral body fixing member 31 of the third embodiment differs from the vertebral body fixing member 11 of the first embodiment only in the surface shape of the dense body portion 32. That is, the dense body portion 32 made of β-TCP, which is a bioabsorbable material, and the porous body portion 13 also made of β-TCP are fixed in a laminated state, and the surface of the dense body portion 32 is engaged with the vertebral body. A plurality of triangular pyramidal or quadrangular pyramidal projections are formed.

(Operation) The operation of the vertebral body fixing member 31 thus configured is the same as that of the first embodiment, except that the vertebral body fixing member 31 is moved between the vertebral bodies 14 as shown in FIG. When inserted, the plurality of protrusions 33 on the surface of the dense body 32 and the vertebral body side are more likely to bite.

(Effect) The effect of using the vertebral body fixing member 31 is that, in addition to the effect of the first embodiment, the fixation immediately after the treatment is improved by the occlusion of the convex portion 33 and the vertebral body side. ,
It is possible to leave the bed earlier.

The convex portion 33 of the vertebral body fixing member 31 is limited to a triangular pyramid or a quadrangular pyramid as long as it can be inserted between the vertebral bodies and has a shape suitable for occlusal engagement with the vertebral body. Instead, for example, the protrusion may be a cylindrical or hemispherical protrusion.

<Fourth Embodiment> (Configuration) FIG. 6 relates to a fourth embodiment of the present invention.
7A is an overall view of a vertebral body fixing member, and FIG. 6B is a cross-sectional view of the vertebral body fixing member.

As shown in FIG. 6, the vertebral body fixing member 41 of the fourth embodiment differs from the vertebral body fixing member 11 of the first embodiment in that a screw 43 and a projecting member 44 are added to a dense body portion 42. different. That is, the dense body portion 42 made of β-TCP, which is a bioabsorbable material, and the porous body portion 13 also made of β-TCP are fixed in a laminated state, and inside the dense body portion 42, FIG. ), A titanium screw 43 having a tapered tip with a small diameter, and a titanium protrusion projecting outward from a side surface of the dense body portion 42 in contact with the vertebral body in conjunction with the screwing operation of the screw 43. A member 44 is incorporated.

(Operation) The operation of the vertebral body fixing member 41 thus configured is the same as that of the first embodiment, except that the vertebral body fixing member 41 is moved between the vertebral bodies 14 as shown in FIG. After the insertion, when the screw 43 of the dense body portion 42 is screwed in, the protruding member 44 protrudes toward the vertebral body 14 and interlocks with this.

(Effect) The effect of using the vertebral body fixing member 41 is the same as that of the first embodiment.
Is inserted between the vertebral bodies 14 and then the screws 43 of the dense body 42 are inserted.
When the screw is screwed in, the protruding member 44 protrudes toward the vertebral body 14 and interlocks with it, so that the vertebral body fixing member 41 can be securely fixed to the vertebral body 14, so that it can be securely fixed and held immediately after the operation.

The configuration of the present embodiment can also be used for a vertebral body fixing member or the like whose main body is made of a structural material for living body such as titanium or carbon fiber.

The materials of the screw 43 and the projecting member 44 are as follows.
The material is not limited to the titanium material, but may be any material having an excellent affinity for bone and excellent mechanical strength, for example, β-TC
P or a material such as a titanium alloy, and the number thereof may be plural. Furthermore, if the materials of the screw 43 and the protruding member 44 are formed of β-TCP described above,
In the long term, all of the vertebral body fixing members 41 can be replaced with autologous bones, which is more preferable for the human body.

<Fifth Embodiment> (Structure) FIGS. 7 and 8 relate to a fifth embodiment of the present invention.
7A is an overall view of a vertebral body fixing member, FIG. 7B is a cross-sectional view of the vertebral body fixing member, FIG. 7C is a front view of the vertebral body fixing member,
FIG. 8 is an explanatory view showing a state in which the vertebral body fixing member of the present embodiment has been subjected to a surgical operation.

As shown in FIG. 7, the vertebral body fixing member 51 according to the fifth embodiment has β in a hollow portion of a cylindrical body 52 made of titanium.
-The structure is filled with a porous body 53 made of TCP. Further, a screw portion 54 is formed on the outer peripheral surface of the cylindrical body 52, and a plurality of windows 55 communicating the porous body 53 and the outer peripheral portion are formed in the valley portion of the screw portion 54.

(Operation) The operation of the vertebral body fixing member 51 thus configured is such that when the vertebral body fixing member 51 is inserted between the vertebral bodies 14 as shown in FIG. The occlusion of the vertebral body 14 strengthens the initial fixation immediately after the operation. After a certain period of time has passed, the internal porous body 53 is replaced with autologous bone, so that more firm fixation can be performed.

(Effect) The effect of the use of the vertebral body fixing member 51 is that the fixation immediately after the treatment is strong, and the porous body 53 is replaced with the autogenous bone with the passage of time, so that the fixation can be surely held. This allows early leaving of the bed.

It should be noted that, as shown in FIG.
At least one reinforcing member 57 made of a titanium material or a dense material is provided inside 3a to increase the strength of the vertebral body fixing member 56, or between the porous body 53 and the main body 59 as shown in FIG. , A dense body 52b made of β-TCP may be provided, or a combination of each may be provided.

The screw portions 54 and 54b may be formed of, for example, a plurality of protrusions, instead of being screw-shaped, as long as the vertebral body fixing member 51 can be inserted between the vertebral bodies 14 with rotation. Further, the cylindrical body 52 having a hollow portion is not limited to a titanium material, but is formed of β-TCP in order to improve strength.
Or, as in the fourth embodiment, a structural material for a living body such as a titanium alloy or carbon fiber may be used, or any combination thereof may be used.

<Sixth Embodiment> (Configuration) FIGS. 10 and 11 relate to a sixth embodiment of the present invention, and FIG. 10A is a front view of a vertebral body fixing member, and FIG.
FIG. 11B is a side view of the vertebral body fixing member, and FIG. 11 is an explanatory view showing a state in which the vertebral body fixing member of the present embodiment has been treated.

The vertebral body fixing member 61 of the sixth embodiment is shown in FIG.
As shown in the figure, a dense body 62 made of β-TCP and a porous body 63 made of β-TCP are also fixed in a laminated state. Part of both surfaces that come into contact with the vertebral body has a shape in which the side surface of the cylindrical body protrudes about the center line 64 as a central axis, and a plurality of connecting members 65 that connect adjacent dense bodies to the surface are formed. It is shaped.

(Operation) As shown in FIG. 11, the operation of the vertebral body fixing member 61 thus configured is such that the vertebral body fixing member 61 is inserted between the vertebral bodies which have been previously cut into a cylindrical shape. After the operation, the strength between the vertebral bodies is maintained by the dense body 62, and the porous body 63 is replaced with autologous bone over time.

(Effect) The effect of using the vertebral body fixing member 61 is, in addition to the effect of the first embodiment, a vertebral body fixing member 61 obtained by cutting the vertebral body fixing member 61 into a cylindrical shape because both surfaces protrude in a cylindrical shape. It can be inserted smoothly between the bodies, and rotation and displacement can be prevented immediately after the treatment. Further, since the outer diameter of the vertebral body fixing member 61 is close to a cylindrical shape, it can be easily inserted endoscopically, and the incision of a minimum size can be performed when the vertebral body fixing member 61 is inserted into the body. It is possible to quickly get out of bed and recover with minimal invasion of the human body.

Although the cylindrical projection has been described on both surfaces, it may be provided on one surface only, or a plurality of cylindrical surfaces may be provided on one surface. Further, the effect is not changed even if one connecting member 65 is not provided.

As described above in detail in each embodiment, the shape of the vertebral body fixing member, the number of laminated layers of the dense body and the porous body, the material, and the like are arbitrarily set without departing from the gist of the present invention. Combinations are possible.

[Appendix] As described in detail above, according to the embodiment of the present invention, the following configuration can be obtained.
[Supplementary Note 1] A vertebral body fixing member for fixing a diseased vertebral body, comprising a bioabsorbable material having osteoconductive ability.
A vertebral body fixing member having a structure in which a porous body and a dense body are combined.

[Supplementary Note 2] A vertebral body fixing member for fixing a diseased vertebral body is a structure made of a porous body and a dense body made of a bioabsorbable material having osteoconductive ability. A vertebral body fixing member, wherein the body is an autogenous bone replacement promoting material, and the dense body is a mechanical strength retaining material for a vertebral body.

[Supplementary Note 3] The vertebral body fixing member according to Supplementary Notes 1 or 2, wherein the porous body portion and the dense body portion have at least one layer in a direction parallel to a main load direction. It is fixed with.

[Supplementary Note 4] In the vertebral body fixing member according to Supplementary note 3, the porous body and the dense body are joined with a biodegradable polymer, collagen, or chitin.

[Supplementary Note 5] The vertebral body fixing member according to any one of Supplementary notes 1 to 4, wherein the porous body portion comprises porous granules made of an osteoconductive bioabsorbable material, a biodegradable polymer,
Alternatively, it is composed of a complex of collagen or chitin.

[Supplementary Note 6] The vertebral body fixing member according to any one of Supplementary Notes 1 to 5, wherein a convex portion is provided on at least one of the surfaces of the dense body portion that comes into contact with the vertebral body.

[Supplementary Note 7] The vertebral body fixing member according to any one of Supplementary Notes 1 to 5, wherein at least one of the surfaces of the dense body contacting the vertebral body is provided with a protrusion formed by a side surface of a cylindrical body.

[Supplementary Note 8] The vertebral body fixing member according to Supplementary Notes 1 to 7, wherein the porous body portion contains a substance having osteoinductive ability.

[Supplementary Note 9] The vertebral body fixing member according to Supplementary note 1 or 2, wherein the vertebral body fixing member includes an operating means,
At least one protruding member that protrudes from the contact surface with the vertebral body by the operation of the operating means is incorporated.

[Supplementary note 10] The vertebral body fixing member according to Supplementary note 1 or 2, wherein the dense body portion has a convex portion on an outer peripheral portion.
Or it has a screw part.

[Supplementary Note 11] The vertebral body fixing member according to Supplementary note 1 or 2, wherein the dense body has a hollow portion communicating with the outside, and the hollow portion is filled with the porous body.

[Supplementary Note 12] In a vertebral body fixing member for fixing a vertebral body of a diseased part, a hollow portion communicating with the outside is provided in a main body made of a structural material for bones having osteophilicity, and osteoconductive in the hollow portion. A vertebral body fixing member filled with a porous body made of a bioabsorbable material having a function.

[0058]

As described above, according to the vertebral body fixing member of the present invention, a vertebral body fixing member in which a dense body portion that maintains initial strength and a porous body portion that can be easily replaced with autologous bones is combined. Since autologous bone collection is not required, it is minimally invasive, and is replaced with autologous bone over time while maintaining the mechanical strength immediately after the procedure, ensuring high safety and enabling early ambulation. It is.

[0059]

[Brief description of the drawings]

FIG. 1 is an overall view showing a vertebral body fixing member according to a first embodiment of the present invention.

FIG. 2 relates to a first embodiment of the present invention, and FIG.
2A is an explanatory diagram showing a state immediately after the treatment, FIG. 2B is an explanatory diagram showing a state at an intermediate stage after the treatment, and FIG.

FIG. 3 is an overall view showing a modified example of the vertebral body fixing member according to the first embodiment of the present invention.

FIG. 4 relates to a second embodiment of the present invention,
(A) is an overall view of a vertebral body fixing member, and (b) is a cross-sectional view of the vertebral body fixing member.

FIG. 5 relates to a third embodiment of the present invention;
5A is an overall view of a vertebral body fixing member, FIG. 5B is a front view of the vertebral body fixing member, and FIG. 5C is a side view of the vertebral body fixing member.

FIG. 6 relates to a fourth embodiment of the present invention.
7A is an overall view of a vertebral body fixing member, and FIG. 6B is a cross-sectional view of the vertebral body fixing member.

FIG. 7 relates to a fifth embodiment of the present invention.
7A is an overall view of a vertebral body fixing member, FIG. 7B is a cross-sectional view of the vertebral body fixing member, and FIG. 7C is a front view of the vertebral body fixing member.

FIG. 8 relates to a fifth embodiment of the present invention, and is an explanatory view showing a state in which a vertebral body fixing member according to the present embodiment has been operated.

FIG. 9 is a side view showing a modified example of the present embodiment according to the fifth embodiment of the present invention.

FIG. 10 relates to a sixth embodiment of the present invention. FIG. 10 (a) is a front view of a vertebral body fixing member, and FIG. 10 (b) is a side view of the vertebral body fixing member.

FIG. 11 is an explanatory view showing a state in which a vertebral body fixing member according to the present embodiment has been treated according to a sixth embodiment of the present invention.

[Explanation of symbols]

11, 21, 31, 41, 51, 56, 58, 61 Vertebral body fixing member 12, 22, 32, 42, 52b, 62 Dense body part 13, 23, 53, 53a, 63 Porous body part 14 Vertebral body 24 poly Lactic acid 33 Convex part 43 Screw 44 Projecting member 52 Cylindrical body 54 Screw part 55 Window 57 Reinforcing member 59 Main body 64 Center line 65 Connecting member

Claims (1)

[Claims] A vertebral body fixing member for fixing a diseased vertebral body, comprising a bioabsorbable material having osteoconductive ability.
A vertebral body fixing member having a structure in which a porous body and a dense body are combined.