JP2002282287A - Spinous projection spacer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spacer having good fixability (compatibility) and capable of shortening the operation time in cervical vertebra spinous projection longitudinal division method vertebral arch forming operation used in curing cervical spondylosis myelopathy, cervical vertebral canal stricture, or cervicale posterior longitudinal ligament osteosis. SOLUTION: In this spinous projection spacer, the body part having sides contacting longitudinally divided spinous projection at both ends has an arch-like shape, and an angle made between both sides is 50 to 80 degrees.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to cervical spondylotic myelopathy,
During cervical spinal canal stenosis or ossification of the posterior longitudinal ligament of the cervical vertebra during cervical spine spinal process laminoplasty, the spinous processes are sandwiched between the spinous processes enlarged after longitudinal splitting and enlarged. The present invention relates to a spinous process spacer for holding a position.

[0002]

2. Description of the Related Art Surgical treatment is one of the treatments for diseases such as ossification of the posterior longitudinal ligament of the cervical spine and cervical spondylotic myelopathy. There are mainly two types of surgical methods. That is, one of the left and right vertebrae is split vertically, the other side is formed by forming a gutter in the other side, and the vertebral arch is opened to one side. Split laminoplasty. The present inventors have considered that there are fewer complications such as nerve root disorders, and have performed cervical spinous process vertical split laminoplasty. In this method, after deploying the cervical vertebra from the posterior side, a gutter is made in both facet joints, the tip of the spinous process is excised, and the spinous process is split vertically. Then, in the expanded part, autologous bone or allogeneic bone such as bone collected from the iliac bone or resected spinous process tip bone is processed and implanted, or using trapezoidal or arcuate ceramic spinous process spacers It is sandwiched between vertically split spinous processes and fastened and fixed with wires, silk thread, synthetic thread, etc., to enlarge the spinal canal of the cervical spine. This allows
The pressure on the spinal cord compressed by the narrow spinal canal can be reduced. However, this method divides the spinous process, and when it is enlarged, the cranial side and the caudal side do not expand equally, and the cranial side opens wider than the caudal side, and there is a difficulty that the spacer holding this expansion is unstable. .

[0003]

However, when performing bone transplantation, it is necessary to collect bone fragments from autologous bone before transplantation, and in particular, collection from the iliac bone involves a secondary invasion of damaging healthy parts. I will be forced. In this case, it is not always possible to obtain a sufficient amount of bone for the treatment, and furthermore, it takes time to process the bone for transplantation, so that there is a problem that the operation time is prolonged and the amount of bleeding is increased.

On the other hand, when the existing spinous process spacer made of ceramic is used, the problem of implanted bone can be solved, but the adhesion to the surface of the vertically split spinous process is insufficient, and the fixability is poor. There is. In other words, when the spinous process is divided vertically, not only the back side (spinous process tip than the spinous process base) opens more widely than the spinal canal, but also the cranial side opens more widely between the caudal side and the cranial side. That's why. However, conventional spacers have not sufficiently considered these points. In addition, since the manner in which the split spines are opened varies considerably from person to person, it is difficult to create a shape that matches the constitution of each individual patient, which further enhances the close contact (compatibility) of the spinous processes with the split surface. Making it difficult. Therefore, it has been considered difficult to produce a spinous process spacer having a shape common to all patients.

Therefore, in the existing spinous process spacer made of ceramic, it was necessary to fasten and fix it with a wire, silk thread, synthetic thread or the like when fixing. However, even if a wire, a silk thread, or a synthetic thread is used, the fixing property is insufficient because the adhesion due to the shape is not sufficient. Even more, it has been considered impossible to fix spinous process spacers without wires, silk, or synthetic threads.

[0006] Furthermore, since the surgical field is narrow in this type of operation, when using a conventional spacer, wires, silk thread,
It is not easy to pass the synthetic thread through the hole of the spinous process that has been split vertically and further through the spacer, and it takes a lot of time. In addition, it takes a considerably long time to fix 5 to 6 spacers used at a time in a normal operation, which causes a problem that the operation time is prolonged and the amount of bleeding is increased.

[0007] If the initial fixation of the spacer to the vertically split spinous process is poor, the spinous process is absorbed by the movement of the spacer, and the fixation of the spacer is further deteriorated. In addition, the wire, silk thread and synthetic thread used for fixing are moved by the movement of the spacer,
It may be severed and the spacer may fall into the spinal canal as a result.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in cervical laminoplasty and the like, to provide a spacer which has good fixability (compatibility) and can reduce the operation time. To provide.

[0009]

The spinous process spacer according to the present invention is a spinous process spacer having a body portion having an arcuate shape at both ends and having a side surface in contact with a vertically split spinous process, wherein an angle formed by both side surfaces is provided. 50-80 degrees. By setting the angle between both sides at 50 to 80 degrees, the compatibility with the cross section of the vertically split spinous process can be improved.

Further, the angle between the two side surfaces is 55 to 7
More preferably, it is 5 degrees. Further, it is preferable that columnar protrusions are formed on both side surfaces. This allows
After being inserted into the fixing hole of the vertically split spinous process, it is possible to slightly rotate the spinous process, and it is possible to obtain compatibility with the vertically split surface of the spinous process. In other words, by slightly rotating the spacer so that the spinal canal surface faces the caudal side (that is, the back surface faces the cranial side), the distance between the vertical cross sections between the split spinous processes is reduced. The head is larger on the caudal side than the caudal side, and the suitability is better. The degree of opening between the spinal canal and the back, and the degree of opening between the head and the tail can be finely adjusted by adjusting the degree of rotation.

It is preferable that the projection made of the same material as that of the main body portion extends substantially vertically from the side surface. Thereby, the stability of the spinous process with the longitudinally split surface can be further obtained. Further, it is preferable that the projection has a columnar shape. This makes it easier to rotate the spinous process to obtain compatibility with the longitudinally split surface.

[0012] In this type of operation, the operation field is narrow, and the spacer itself becomes longer only at its protruding portion. Therefore, it is not easy to insert the spacer. However, if the length of the projection is shortened, the protrusion easily comes off. To solve this problem,
That is, the length of the projection is preferably 2.5 to 5.5 mm in order to facilitate insertion and prevent dislodgment, and more preferably, it is just as long as penetrating the fixing hole, that is, 3.5 mm. 〜4.5 mm. Further, the diameter of the projection is more preferably 1 to 3 mm. With this length, the strength of the projection can be secured.

The vertical length of the side surface is 4 to 8 mm,
The horizontal length is preferably 4 to 8 mm, and more preferably the vertical length is 6 mm and the horizontal length is 6 mm.
Thereby, it is possible to easily rotate the spinous process to obtain the suitability of the longitudinally split surface, and to further ensure the strength of the spinous process spacer.

It is preferable that the length of the main body portion in the direction perpendicular to the spinal canal on the back side is 16 to 23 mm. Further, the length in the vertical direction with respect to the spinal canal on the back side of the main body portion is 1
It is preferably from 8 to 22 mm.

In the spinous process spacer of the present invention, it is not particularly necessary to fasten and fix with a wire, a silk thread, a synthetic thread or the like when fixing, but it does not matter at all if fixing with these.

[0016]

Embodiments of the present invention will be described below in detail. FIG. 1 shows a preferred embodiment of the present invention. In the figure, reference numeral 1 denotes a spacer, which is composed of a main body portion 11 having side surfaces 111 and 112 in contact with the vertical split surface of the spinous process, and protrusions 12 and 13 formed substantially in the center of the side surfaces 111 and 112. Become. The angle between the side surfaces 111 and 112 may be appropriately selected in the range of 50 to 80 degrees.
When this angle is out of the above range, it is difficult to bring the vertically split surface of the spinous process into close contact with the spacer.

The body portion 11 preferably has an arcuate shape for reasons of preventing compression of the spinal canal. Further, it is preferable that the angle formed by the head-side surface 113 and the back-side surface 114 of the main body portion 11 is chamfered. That is, since this portion projects to the head side during rotation, when the patient bends the head backward, the adjacent spacer does not come into contact with the corner. Also the head side surface 113
It is preferable that the corner formed by the surface 115 on the side of the spinal canal is also chamfered. In other words, this portion projects toward the spinal canal during rotation, so that the corner does not compress the spinal cord.

The projections 12 and 13 are desirably formed perpendicular to the side surfaces 111 and 112. this is,
When the spacer 1 is rotated to bring the side surfaces 111 and 112 into close contact with the vertical split surface of the spinous process, the projections 12 and 13 become vertical to the vertical split surface of the spinous process, and good fixation is obtained. is there. If the projections 12 and 13 are formed in a columnar shape,
In addition to facilitating the rotation of the spacer 1, the protrusions 12,
The space between the spinous process into which the 13 is inserted and the fixing hole can be minimized, and the fixability can be further improved.

The spacer having the above-mentioned structure includes tricalcium phosphate, a composite material of tricalcium phosphate and hydroxyapatite, ceramic materials such as alumina, zirconia, hydroxyapatite, calcium phosphate and tetracalcium phosphate, calcium phosphate glass, calcium phosphate glass. Any material can be used as long as it has good biocompatibility, such as bioactive glass materials such as crystallized glass, high biocompatible organic compounds such as high density polyethylene (HDPE), and metallic materials such as titanium. It is. Among them, especially hydroxyapatite, calcium phosphate, tetracalcium phosphate, calcium phosphate glass,
It is preferable to form the spacer with a bioactive material such as a calcium phosphate crystallized glass, since direct bonding with natural bone becomes possible.

Next, a method of using the spacer of the present invention will be described.
This will be described with reference to FIG. First, the side grooves 21 and 22 are
After the formation of the spinous process, the spinous process is longitudinally split and enlarged. Next, a fixing hole is formed at a substantially central portion of the vertically split spinous processes 31 and 32. Subsequently, the protrusion 1 of the spacer 1 is inserted into the fixing hole thus formed.
Insert 2 and 13. Thereafter, the spacer 1 is slightly rotated so that the surface 114 on the spinal canal side faces the caudal side (that is, the back surface 116 faces the cranial side), so that the side surface 111 of the spacer 1 Contact 112 closely.

After the operation, the spacer placed between the spinous processes is pressed from both sides so that the vertically split spinous processes tend to close. Due to the pressing force and the presence of the projections 111 and 112, the spacer 1 of the present invention is firmly fixed between the spinous processes.

[0022]

The use of the spinous process spacer of the present invention eliminates the need for bone extraction. Moreover, it can be in close contact with the vertically split surface of the vertically split spinous process, and is excellent in fixability. Further, unlike the conventional spacer, the time for fastening with a wire, silk thread, synthetic thread, or the like is not required. Therefore,
The time required for the operation can be greatly reduced, and as a result, the amount of bleeding can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a spinous process spacer of the present invention, wherein (a) is a plan view of the spacer and (b)
Shows a front view, and (c) shows a side view.

FIG. 2 is an explanatory view showing a use state of a spinous process spacer of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spinous process spacer 11 Main body part 111,112 Side surface 12,13 Projection 113 Head side surface of main body part 114 Back side surface of main body part 115 Surface of main body part on spinal canal side

Claims (12)

[Claims] 1. A spinous process spacer having an arcuate body portion having a side surface at both ends in contact with a vertically split spinous process, wherein an angle formed by both side surfaces is 50 to 80 degrees. 2. The spinous process spacer according to claim 1, wherein the angle formed by the both side surfaces is 55 to 75 degrees. 3. The spinous process spacer according to claim 1, wherein a protrusion is formed on each side surface. 4. A projection made of the same material as the main body portion extends substantially vertically from the side surface.
4. The spinous process spacer according to any one of items 3 to 3. 5. The spinous process spacer according to claim 1, wherein the protrusion has a columnar shape. 6. The spinous process spacer according to claim 1, wherein the length of the protrusion is 2.5 to 5.5 mm. 7. The spinous process spacer according to claim 1, wherein the length of the protrusion is 3.5 to 4.5 mm. 8. The spinous process spacer according to claim 1, wherein the diameter of the protrusion is 1 to 3 mm. 9. The spinous process spacer according to claim 1, wherein the length of the side surface is 4 to 8 mm and the width is 4 to 8 mm. 10. The spinous process spacer according to claim 1, wherein the side surface has a vertical length of 5 to 7 mm and a horizontal length of 5 to 7 mm. 11. The spinous process spacer according to claim 1, wherein the length of the main body portion in a direction perpendicular to the spinal canal on the back side is 16 to 23 mm. 12. The spinous process spacer according to claim 1, wherein a length of the main body portion in a direction perpendicular to the spinal canal on the back side is 18 to 22 mm.