JP2003220071A - Fixation device for osteosynthesis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixation device for osteosynthesis which is compact and lightweight, needs no special instruments for the attachment, can be attached in a short time, simplifies a surgery, hardly causes cracks and fractures of the bone, hardly affects the performance of a CT scan after the surgery, can fixate the bones in a well-balanced manner by stably contacting between the bones, can be adjusted easily after the fixation, can be used for a slant cutting plane, can fixate the bones regardless of the size and strength of the bone, and can be produced inexpensively. <P>SOLUTION: The fixation device for osteosynthesis includes a pair of tension coil springs 1 which are made by winding a titanium or titanium alloy wire into a coil shape while the wire is contacting closely, have both end parts 2, 3 with the outer diameter larger than that of a middle part 4, have the front ends of both end parts 2, 3 bending at the inner diameter to the inside in the axial direction, and have sharp head parts 5, 6 on the front ends. The bones 11, 12 to be connected are held between the pair of the supporting parts comprising both end parts 2, 3, and the bones are fixated by a resilient force of the tension coil springs. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bone graft fixing device for fixing cut bones such as plug bones to be removed from a skull during a surgical operation in an original position to re-bond them.

[0002]

2. Description of the Related Art In brain surgery, a skull is cut to remove a part thereof, and the removed part is used as a plug bone to be positioned and fixed in the original position after surgery and joined by a self-regenerating function. In this case, a plate made of metal such as titanium or titanium-based alloy, which has excellent biocompatibility, with holes for screws is laid between bones and fixed with bolts, or a metal piece with grip teeth is used. Conventionally, a method of joining the bones and a method of making holes in the bones on both sides along the cut portion and suturing with a loop-shaped steel wire have been conventionally used.

Further, as described in Japanese Patent No. 3011896, the inner surface is concave, the outer surface is convex, teeth are formed in a row along the peripheral edge of the concave side, and a through hole is formed in the center. Using a device consisting of two discs and a pin connecting the two discs, one disc is attached to the shaft of the pin, and with the shaft protruding outward, the skull and plug bone Insert into the inside of the cut, attach another disk from the outside to the pin axis, and then use a riveting tool to press and fix until the teeth of the two disks bite into the bone, or A method of forming a threaded portion on a shaft of a pin and tightening a nut has been known.

[0004]

However, the above conventional method has the following problems.

That is, in the method of bridging a metal plate between bones and fixing it with bolts, it takes time to tighten the bolts, the operation time becomes long, and the plate is thick and heavy. The burden on the patient is heavy.

[0006] Further, in the method of bone-bonding using a metal piece having grip teeth, when the tips of the grip teeth bite into the bone and the affected area is strongly shocked in the post-operative life, the grip teeth are Stress is concentrated on the tip of the bite part, and there is a possibility that the bone may crack or a new fracture may occur from that point.

In the method of suturing with a wire, the contact between bones is unstable and wobbling occurs, and the image obtained by computer tomography after surgery is greatly distorted by the wire, which causes a soft structure of the brain. Accurate grasp becomes difficult.

Furthermore, the method of connecting two discs with a pin and tightening it requires the use of a special tool, and because the pin is not flexible, the cut surface of the bone is inclined. There is a problem that the contact between the bones may become unstable, and after fixation, it takes time to correct when there is an unstable part due to poor overall balance.

The present invention is intended to solve these problems, is small and lightweight, does not require a special tool for installation, can be installed in a short time, can simplify surgery, and can crack bones. And new fractures will not occur, and will not interfere with postoperative computed tomography,
The bones can be stably contacted and fixed in a well-balanced manner, and corrections after fixation are easy, and even when the cut surface of the bone is oblique, it can be fixed stably regardless of the size or strength of the bone. An object of the present invention is to provide a bone anchoring fixture that can be manufactured at low cost.

[0010]

SUMMARY OF THE INVENTION A bone graft fixing device of the present invention comprises a pair of support parts for sandwiching a bone to be joined from both sides of a cut part, and a connecting part for connecting the pair of support parts through a gap between the cut parts. A bone-bonding fixture that is made of a material and is fixed to an original position by sandwiching a cut bone and re-bonded to the original position, wherein the support portion and the connection portion are integrally formed of a spring material having a biocompatibility so as to form a tension coil spring. It is characterized by being formed as.

In this bone joint fixing device, one of the supporting portions constituted by a predetermined portion of the tension coil spring is hooked on both sides of the bone to be joined from one side of the cutting portion, the other supporting portion is pulled, and the connecting portion is connected. With the stretched state, position the other support so that it contacts the bones on both sides from the other side of the cut, and release the pulled support to sandwich the bones on both sides and restore the tension coil spring ( It can be fixed by spring force) and is formed as an integral tension coil spring,
It is small and lightweight, requires no special tools for installation, can be installed in a short time, simplifies surgery, and reduces the burden on doctors and patients. Also, by forming it as an integral tension coil spring,
In particular, it is possible to avoid a structure in which stress is concentrated, and it is possible to prevent cracks and new fractures in the bone. Further, it can be formed in a small size, the number of mounting positions and the number thereof can be limited, and it is possible to prevent a problem in post-operative computer tomography. In addition, since the connecting part is flexible, it is possible to make stable contact between bones and fix them in a well-balanced manner, and it is easy to correct them after fixation, and even if the cut surface of the bone is diagonal, it can respond without inconvenience. , It can be fixed stably regardless of the size and strength of the bone. Further, by forming it as an integral tension coil spring, it can be manufactured at low cost.

Titanium or a titanium-based alloy is particularly suitable as the material for the spring used in this bone joint fixing device. Titanium and titanium-based alloys are spring materials with excellent biocompatibility and do not distort the image obtained by postoperative computer tomography.

In a more specific form of this bone-fixing fixture, the outer diameters of both ends of the tension coil spring are made larger than the outer diameter of the intermediate portion, and the both end portions having a large outer diameter constitute the support portion. , It is preferable that the intermediate portion having a small outer diameter constitutes the connecting portion, and the tip portions of both end portions bend from the inner diameter side of each end portion along the outer diameter of the intermediate portion toward the inner side in the axial direction, It is good that the tip of the bent portion is pointed.

In this way, the fixing device for bone attachment formed as an integral tension coil spring hooks the supporting portion on one end side to the bones on both sides to be joined from one side of the cutting portion and pulls the supporting portion on the other end side. With the connecting part extended, position the support part on the other end so that it contacts the bones on both sides from the other side of the cutting part, and release the tensioned support part so that the bones on both sides are sandwiched. It can be fixed by the restoring force (spring force) of the bent ends, and the tips of the bent end parts that have been subjected to the pointed process pierce the bone and grip the bone to prevent positional displacement and provide a more stable fixation. It will be possible.

The spring material used may have a round or irregular cross section and can be manufactured at low cost.

The bone graft fixing device is particularly suitable as a device for fixing the plug bone removed during the surgical operation to the skull after the operation.

[0017]

DETAILED DESCRIPTION OF THE INVENTION An example of an embodiment of the present invention will be described below with reference to the drawings.

1 to 3 relate to an example of an embodiment of the present invention, FIG. 1 is a plan view (a) and a front view (b) of a bone grafting fixture, and FIG. 2 is a procedure for attaching the bone grafting fixture. And FIG. 3 is an explanatory view of a state in which a bone anchoring fixture is attached.

The bone graft fixing device shown in this example is used for fixing cut bones to their original positions and joining them by a self-regenerating function, such as fixing a plug bone removed during a surgical operation to a skull after the operation. As shown in FIGS. 1 (a) and 1 (b), the integral tension coil spring 1 is a spring material made of titanium (Ti) or a titanium-based alloy, which is a spring material excellent in biocompatibility. A wire having a round cross section is closely wound in a coil shape, and at that time, the outer diameters of two to three turns of the end portions 2 and 3 of the tension coil spring 1 are larger than the outer diameter of the intermediate portion 4 depending on the part. In addition, the tip portions of the both end portions 2 and 3 are bent toward the inner diameter side of the end portions 2 and 3 at the positions facing each other in the radial direction in a plan view, and further, along the outer diameter of the intermediate portion 4, The shape is bent toward the inside of the direction.

At the tip of the bent portion,
It is sharpened in advance and when bent, each end 2, 3
The tip parts 5, 6 at the tip of are directed to the inner side in the axial direction along the outer diameter of the intermediate part 4 and project from the end parts 2, 3 having the larger outer diameter to the inner side in the axial direction by a predetermined dimension. ing.

This tension coil spring 1 (fixture for bone joint)
Is a pair of support parts that sandwich the bone to be joined from both sides of the cutting part, and the middle part 4 is
A connecting portion that connects the pair of support portions is formed through a gap between the cut portions of the bone.

The tension coil spring 1 has, for example, a material (wire) diameter of 0.25 to 0.35 mm, and both ends 2 and 3 serving as support portions have coil outer diameters of 0.7 to 1.0 mm and are connected. The outer diameter of the coil of the intermediate portion 4 serving as the portion is set to 2.0 to 5.0 mm, but is not limited to this, of course. The length of the intermediate portion 4 in the free state (close contact state) is set to be shorter than the thickness of the bones 11 and 12 to be joined. The cross section of the material (wire) may be irregular.

When used, as shown in FIG. 2, the supporting portions constituted by the one end portion 2 of the tension coil spring 1 are abutted at the cutting portions 11a, 12a to join the bone portions 11, 12 on both sides. (For example, the bone 11 is a skull and the bone 12
Is the plug bone removed during surgery. ), The cutting portion 11a,
12a is hooked from one side (the inside of the skull), and the support portion constituted by the other end portion 3 is pulled outward (in the direction of the arrow in FIG. 2) through the gap between the cut portions 11a and 12a, so that one end The tip 5 of the tip of the part 2 has bones 11 and 1
2 extends the intermediate portion 4 (connecting portion) while piercing one side (for example, the skull side), and the other supporting portion (end portion 3) is attached to the bones 11 and 12 on both sides on the other side of the cutting portions 11a and 12a ( Position it so that it contacts from the outside of the skull) and release the pulled support (end 3).

As a result, as shown in FIG. 3, the pointed portion 6 at the tip of the other end 3 pierces the other of the bones 11 and 12 (for example, the plug bone side), and a pair of support portions (end 2). 3) sandwiches the bones 11 and 12 on both sides and fixes them by the restoring force (spring force) of the tension coil spring 1.

The thus fixed bones 11 and 12 are joined with each other over time due to the self-regenerating function.

This fixing tool for bone graft is not only used for fixing the plug bone removed during brain surgery to the original skull, but also for fixing the bone cut during surgery of other parts, or for fracture. When fixing a bone that has been cut with
It can be widely used for fixing cut bones and joining them by a self-regenerating function.

The fixing device for bone attachment can be formed as the extension coil spring 1 integrally as described above, and can be made compact and lightweight. The tension coil spring 1 can be attached in a short time by simply hooking and extending the extension coil spring 1 as described above, without requiring a special tool for attachment. Therefore, the operation can be simplified and the burden on the doctor and the patient can be reduced.

Further, this bone joint fixing device is formed by an integral tension coil spring 1 and a pair of cusps 5 and 6 pierce the bone, but the cusps 5 and 6 have a cone with no peripheral corners. The shape can prevent stress from being generated in the bone such as cracking or new fracture.

Further, this bone joint fixing device can be formed in a small size, and a small number can be arranged at intervals to limit the mounting positions and the number thereof, and titanium and titanium-based alloys can be obtained by computer tomography. Since the image is not distorted, the post-operative computed tomography can be prevented from being disturbed.

Further, in this bone joint fixing device, since the intermediate portion 4 of the tension coil spring 1 constituting the connecting portion is flexible, the bones can be stably contacted and fixed in good balance. Can be easily corrected, and it can cope with the case where the cut surface of the bone is oblique, and can be stably fixed regardless of the size and strength of the bone.

Further, this bone joint fixing device can be manufactured at low cost as the integral coil spring 1.

[0032]

As is clear from the above description, the bone graft fixing device of the present invention has the following effects.

By forming it as an integral tension coil spring, it can be made compact and lightweight, it does not require a special tool for attachment, it can be attached in a short time, the operation can be simplified, and the burden on the doctor and the patient can be reduced. Can be reduced.

By forming it as an integral tension coil spring, it is possible to avoid a structure in which stress is particularly concentrated, and it is possible to prevent cracks or new fractures in the bone.

By forming the coil spring as an integral one, it can be formed in a small size, and the mounting position and the number of the coil springs can be limited.

By forming it as an integral tension coil spring, it is possible to give flexibility to the connecting portion, to make stable contact between the bones, and to fix them in a well-balanced manner. Even if the cut surface of the bone is oblique, it can be coped with without any inconvenience and can be stably fixed regardless of the size and strength of the bone.

By using titanium or a titanium-based alloy as a spring material, excellent biocompatibility,
The image obtained by postoperative computer tomography can be prevented from being distorted.

The outer diameters of both ends of the tension coil spring are made larger than the outer diameter of the intermediate portion, the both end portions having the larger outer diameter constitute the supporting portion, and the intermediate portion having the smaller outer diameter constitutes the connecting portion. As a result, it is possible to provide a bone joint fixing tool that can be stably fixed as the integral tension coil spring with the restoring force (spring force) of the tension coil spring sandwiching both sides of the bone. Further, by adopting a configuration in which the bone is gripped by the tips of which the tip ends of the bent end portions are processed, more stable fixation becomes possible.

It can be inexpensively formed by using a spring material having a circular or irregular cross section.

It is particularly suitable as a device for fixing plug bones removed during surgery to the skull after surgery.

[Brief description of drawings]

FIG. 1 is a plan view (a) and a front view (b) of a bone anchoring fixture according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a procedure for attaching the bone anchoring fixture according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a state in which the bone-attaching fixture according to the embodiment of the present invention is attached.

[Explanation of symbols]

1 tension coil spring A few ends (support) 4 Middle part (connecting part) 5, 6 pointed head 11, 12 bones 11a, 12a cutting part

Claims (6)

[Claims] 1. A pair of support parts that sandwich the bone to be joined from both sides of the cut part, and a connecting part that connects the pair of support parts through a gap between the cut parts, and the original position with the cut bone sandwiched therebetween. A bone joint fixing device for fixing and re-bonding to a bone joint, wherein the supporting portion and the connecting portion are formed as an integral tension coil spring from a biocompatible spring material. 2. The bone anchoring fixture according to claim 1, wherein the spring material is titanium or a titanium-based alloy. 3. The tension coil spring has outer diameters at both ends larger than an outer diameter of an intermediate portion, both end portions having a large outer diameter constitute the support portion, and an intermediate portion having a small outer diameter is the connecting portion. The bone anchoring fixture according to claim 1, which constitutes a part. 4. The tension coil spring is such that the tip portions of both end portions are bent from the inner diameter side of each end portion toward the inner side in the axial direction along the outer diameter of the intermediate portion, and the tip ends of the bent portions are sharpened. The bone anchoring fixture according to claim 3, wherein the head is processed. 5. The bone anchoring fixture according to claim 1, wherein the spring material has a round or irregular cross section. 6. The bone graft fixing device according to claim 1, which is a device for fixing the plug bone removed during the surgical operation to the skull after the operation.