JP4351372B2 - Bone flap fixation washer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a washer used in a device for fixing a bone flap that seals a craniotomy site to a skull, and more particularly, to a washer used in a device for fixing an artificial bone flap.
[0002]
[Prior art]
When returning the autologous bone flap removed by craniotomy to the original site or reducing the craniotomy site using an artificial bone flap, it is necessary to fix the bone flap to the skull.
[0003]
FIG. 5 shows an example of a conventional bone flap fixing device. The bone flap fixing device 11 is of a type in which a bone is sandwiched between a metal plate 12 with a pin shaft 14 and a metal plate 13 that passes through the pin shaft 14. Engaging teeth 15 are provided on the periphery of the opposing surface of one or both of the metal plates 12 and 13. The bone flap fixing device 11 can finally fix the metal disc 13 to the pin shaft 14 by using a tool of a type that cuts the pin shaft 14 and simultaneously crushes the cut end to form a predetermined shape. The time required for the fixing work is very short, the operation is simple, and a sufficient fixing force can be obtained.
[0004]
[Problems to be solved by the invention]
However, although the conventional bone flap fixing device is effectively used for fixing autologous bone, it is not used for fixing artificial bone flap. The reason is that when the above-mentioned fixing device is used for fixing an artificial bone flap, when the artificial bone valve is made of a material having low toughness such as alumina ceramics, the opposing surfaces of the artificial bone valve and the metal plate are in direct contact with each other at the time of fixing. This is because there is a risk of breakage due to stress. In addition, as a result of sliding of the artificial bone flap and the metal disk due to the micro-movement associated with the movement of the jawbone, metal wear powder harmful to the living body is generated.
[0005]
The present invention has been made in view of such problems of the prior art, and an object of the present invention is to enable the bone flap fixing device to be effectively used for an artificial bone flap.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problem, a bone flap fixing device of the present invention includes a first metal plate with a shaft and a second metal plate that faces the first metal plate and is inserted through the shaft. A bone flap fixing device, wherein at least one of the opposing surfaces of the first metal disc and the second metal disc is provided with a disc-like body made of a polymer material stable to a living body. The body includes a small hole penetrating in the thickness direction and a split communicating with the small hole from a peripheral surface , and teeth are provided on at least one peripheral edge of the first metal disk and the second metal disk. Provided, and the teeth engage with the disc body .
[0007]
In a certain embodiment, the said board-like body is each provided in the surface where a 1st metal board and a 2nd metal plate oppose.
[0008]
In one embodiment, it is for an artificial bone flap.
[0009]
In one embodiment, a cylindrical protrusion portion coaxial with the small hole is provided around the small hole in the disk-shaped body.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0016]
1 is an exploded perspective view of a bone valve fixing device washer (hereinafter abbreviated as a washer) and a bone valve fixing device using the same according to the present invention, and FIG. 2 is an assembled perspective view of the bone valve fixing device of FIG. FIG. 3 is an explanatory diagram of a use state, and FIG. 4 is an explanatory diagram of a use state of a bone flap fixing device using a washer according to another embodiment. In these drawings, reference numeral 1 is a washer, 2 is a small hole, 3 is split, 11 is a bone flap fixing device, 12 and 13 are metal plates, and 14 is a pin shaft.
[0017]
The washer 1 includes a small hole 2 penetrating in a thickness direction of a disk-shaped body made of a polymer material safe for a living body, and a split 3 communicating with the small hole 2 from a peripheral surface of the disk-shaped body.
[0018]
Further, one or both washers 1 are provided with a cylindrical protrusion 4 coaxial with the small hole 2 around the small hole 2 on one side of the surface where the small hole 2 of the plate-like body opens. The width of the split 3 provided in the washer 1 is smaller than the diameter of the small hole 2, thereby preventing the washer 1 from being easily detached from the pin shaft 14 of the bone flap fixing device 11 described later. is doing.
[0019]
The polymer material constituting the washer 1 is a substance that is very stable in the living body and is generally called “polymer biomaterial”, that is, silicone, polyethylene, polyolefin-based material, and the like. It is preferable to use it. According to such a configuration, since the polymer material is very stable in the living body, even if it is taken into the living body as fine wear powder, it is not harmful to the living body.
[0020]
The size of the washer 1 is approximately φ10 to 25 mm, and the size is determined according to the size of the bone flap fixing device to be used. Moreover, the thickness of the washer 1 should just be about 0.5 mm.
[0021]
Next, the bone flap fixing device 11 to which the washer 1 is attached is of a type in which a bone is sandwiched between a metal plate 12 with a pin shaft 14 and a metal plate 13 through which the pin shaft 14 is inserted. Engaging teeth 15 are provided on the periphery of the opposing surface of one or both of the metal plates 12 and 13. The bone flap fixing device 11 can finally fix the metal plate 13 to the pin shaft 14 using a tool of a type that cuts the pin shaft 14 and simultaneously crushes the cut end to form a predetermined shape.
[0022]
As described above, the washer 1 has the small hole 2 and the split 3 communicating with the small hole 2, so that the washer 1 is attached to the pin shaft 14 from the direction orthogonal to the pin shaft 14 using the split 3. Can do. As shown in FIG. 2, the washer 1 is mounted on the opposing surface side of the metal plates 12 and 13 in the bone flap fixing device 11.
[0023]
As shown in the explanatory view of the state of use in FIG. 3, the bone flap fixing device 11 equipped with the washer 1 is damaged by the fixing stress due to the direct contact between the opposed surfaces of the artificial bone valve S and the metal plates 12 and 13. To prevent things. Further, as a function of the cylindrical protrusion 4 provided in the washer 1, direct contact between the pin shaft 14 of the bone flap fixing device 11 and the artificial bone valve S can be prevented.
[0024]
Next, as another embodiment of the washer 1, as shown in FIG. 4, in the washer 1, a thick portion 5 may be appropriately provided on one of the surfaces where the small holes of the disk-shaped body are opened. As shown in the figure, for example, about half of the washer 1 is a thickened portion 5, and the thickened portion 5 absorbs the difference in thickness between the skull B and the artificial bone flap S, and the metal of the bone flap fixing device 11 is absorbed. The boards 12 and 13 can be kept in parallel positions without being relatively inclined. As a result, the skull B and the artificial bone flap S can be clamped with a stable fixed state and a large fixing force.
[0025]
As mentioned above, although embodiment of this invention was illustrated, this invention is not limited to these embodiment, Unless it deviates from the essence of invention, it can be set as arbitrary forms.
[0026]
【The invention's effect】
As described above, the present invention includes a small hole that penetrates the thickness direction of a disk-shaped body made of a polymer material that is safe for living bodies and a split that communicates with the small hole from the peripheral surface of the disk-shaped body. The artificial bone flap and the metal disc can be mounted on the opposite surface side of the metal disc in the type of bone fixing device in which the bone is clamped by the metal disc with the pin shaft and the metal disc inserted through the pin shaft using the split. It is possible to prevent the opposing surfaces of the glass from being in direct contact with each other and being damaged by a fixing stress.
[0027]
Therefore, by using the washer, when fixing an artificial bone flap, which is a feature of a bone flap fixing device that clamps bone with a metal disc with a pin shaft and a metal disc inserted through the pin shaft, it is fixed. The time required for the work is very short, the operation is simple, and a sufficient fixing force can be obtained.
[0028]
Further, since the washer can be attached to the pin shaft very easily by splitting, the bone flap fixing device can be easily changed to a self bone flap or an artificial bone flap.
[0029]
Furthermore, the washer according to the present invention can prevent direct contact between the pin shaft of the bone flap fixing device and the artificial bone valve when a cylindrical projection coaxial with the small hole is provided.
[0030]
Moreover, the washer of this invention can fix an artificial bone flap stably, even when the thickness of a bone and an artificial bone flap differs remarkably when a thick part is provided in the said board-shaped body.
[0031]
Furthermore, when the washer of the present invention uses a silicone, polyethylene, or polyolefin-based polymer material as the polymer material constituting the washer, these polymer materials are extremely stable in the living body, and therefore, fine wear. Even if it is taken into the living body as a powder, it is not harmful to the living body.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a washer of the present invention and a bone flap fixing device using the same.
2 is an assembled perspective view of the bone flap fixing device of FIG. 1; FIG.
FIG. 3 is an explanatory diagram of a use state of the bone flap fixing device of FIG. 1;
FIG. 4 is an explanatory diagram of a use state of a bone flap fixing device using a washer according to another embodiment of the present invention.
FIG. 5 is a perspective view of a bone flap fixing device used to fix an autologous bone flap.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Washer 2 Small hole 3 Split 4 Cylindrical protrusion 5 Thick part 11 Bone flap fixing device 12 Metal plate 13 Metal plate 14 Pin shaft 15 Teeth S Artificial bone flap B Skull

Claims (4)

A bone flap fixing device comprising a first metal disk with a shaft and a second metal plate facing the first metal disk and inserted through the shaft,
At least one of the opposing surfaces of the first metal disk and the second metal disk is provided with a disk-shaped body made of a polymer material that is stable to a living body,
The disk-shaped body includes a small hole penetrating in the thickness direction and a split communicating with the small hole from a peripheral surface ,
A bone flap fixing device , wherein teeth are provided on a peripheral edge of at least one of the first metal disc and the second metal disc, and the teeth engage with the disc-like body .   The bone flap fixing device according to claim 1, wherein the disc-like body is provided on each of opposing surfaces of the first metal disc and the second metal plate.   The bone flap fixing device according to claim 1 or 2, which is used for an artificial bone flap.   The bone flap fixing device according to any one of claims 1 to 3, wherein a cylindrical protrusion portion coaxial with the small hole is provided around the small hole.

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