JPH114840A - Vertebral canal expanding operation spacer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance falling-off resistance, and shorten operation time by arranging an inside hook part and an outside hook part mutually projecting to the opposite side in a vertebral canal expanding operation spacer which separates a vertebral arch containing a spine from a vertebral canal and is inserted between both side surfaces of this vertebral arch and a vertebral canal outside lump. SOLUTION: A vertebral arch 22 containing a spine 21 is separated from a vertebral body 20 having a vertebral canal, and a spacer 10 is interposed along its cutting line (a cutting margin) (s) between both side surfaces of this separated vertebral arch 22 and a vertebral canal (vertebral body) outside lump 23 of a residual part. A spacer 10 used for such a vertebral canal expanding operation is formed into a uniform cross-sectional shape of a cross-sectional almost Z shape so that a pair of hook parts 12 and 13 are respectively formed in both end parts of flat parts 11 by setting the directions inversely. In this spacer 10, the projecting inside edges from the plane parts 11 of the hook parts 12 and 13 are formed as the right-angled inside edges 12a and 13a being an almost right angle to the plane parts 11, and outside end parts are formed as the inclined outside edges gradually approaching these right-angled inside edges 12a and 13a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spacer suitable for use in spinal canal augmentation, in particular, a laminectomy spinal canal enlargement.

[0002]

2. Description of the Related Art The vertebral canals (vertebral bodies) that contain and protect the spinal cord include the cervical cervical vertebra, the thoracic thoracic vertebra, and the lumbar lumbar vertebra. These spinal canals, for example, for diseases such as lumbar spinal canal stenosis and lumbar deformity slip, for tumor removal,
The canal may become narrow, and spinal canal enlargement is performed to widen it. This spinal canal enlargement basically involves treating the vertebral arch of the spinal canal to enlarge the diameter of the spinal canal. The latter is further divided into one-sided type, spinous process split type, and lamine free type. Laminectomy is a technique in which a vertebral arch, including spinous processes, is separated from the spinal canal and the separated vertebral arch is rejoined to the spinal canal by some means.

[0003] Conventionally, in this spinal canal enlargement of the lamine type, attempts have been made to use a block made of biocompatible ceramics as a spacer (supplementing material) used for securing space. However, the conventional products are easy to fall off, require a long operation time, and cannot be said to have excellent connectivity between the spinal canal (outer mass) and the dissected vertebral arch. There is also a problem that the pressure in the spinal canal is insufficiently decompressed.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a spacer for use in a laminoplasty spinal canal augmentation, which is less likely to fall off from the spinal canal (vertebral body) and the dissected vertebral arch. The burden on the surgeon and the patient can be reduced, the pressure inside the tube can be sufficiently reduced,
An object of the present invention is to obtain a spacer capable of obtaining a strong laminoplasty.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a spinal canal dilatation swab for separating a vertebrae including spinous processes from a spinal canal and for inserting the vertebrae between the lateral sides of the dissected vertebra and the remaining lateral spinal canal mass. In (c), a plane portion located between the side surface of the dissected lamine and the outer canal of the spinal canal, and an inner hook portion protruding toward the center of the dissected lamine on the inner end side of the spinal canal of this flat portion, An outer hook portion on the outer end side of the spinal canal of the flat portion and protruding in a direction away from the incised lamineum,
It is characterized by having.

The spacer for dilatation of the vertebral canal of the present invention may be formed for each of the left and right sides of the incised vertebral arch. However, preferably, the spacer is rotationally symmetric with respect to the longitudinal center of the plane portion. It is desirable that the cross section be formed in a similar cross-sectional shape and be turned upside down so as to be positioned on the left and right sides of the incised vertebra in a line-symmetrical shape with respect to the cross-sectional center line of the incised vertebra.

[0007] The spinal canal enlargement spacer of the present invention is made of biocompatible ceramics. Above all, it is preferable to be composed of glass ceramics or a calcium phosphate compound having a Ca / P ratio of 1.0 to 2.0. Examples of the calcium phosphate compound having a Ca / P ratio of 1.0 to 2.0 that can be used in the present invention include various apatites such as hydroxyapatite and fluorapatite, calcium monophosphate, dicalcium phosphate, tricalcium phosphate, and phosphoric acid. Tetracalcium and the like can be mentioned, and these can be used alone or as a mixture. After drying the raw material compound slurry, calcining at 500 to 800 ° C.
It is fired at 0 to 1400 ° C., and the obtained block-shaped body is processed into a desired shape and dimensions, or a green compact having a desired shape and dimensions is prepared from the powder of the calcium phosphate-based compound. It can be manufactured by firing in the same manner as described above.

In the present invention, by forming at least the surface of the spacer for spinal canal enlargement from a porous ceramic having biocompatibility, it has a good affinity for the surrounding bone tissue, and the bone tissue enters the pores. Invasion promotes bone fusion. The porous ceramic preferably has continuous pores. The pore diameter and porosity are not particularly limited, but usually the pore diameter is preferably 1 to 600 μm, and the porosity is 0 to 60%, preferably 15 to 50%.

The central portion may be composed of dense or porous ceramics. Examples of usable ceramics include calcium phosphate compounds having a Ca / P ratio of 1.0 to 2.0, alumina, titania, zirconia and the like. Among these, a calcium phosphate compound is preferred. There is no particular limitation on the method of providing a layer of a porous biocompatible material on the surface of the central portion made of dense ceramics, and any known method can be adopted.
Examples include a thermal spraying method, a sputtering method, an impregnation method, and a spray coating method.

The spacer for dilatation of the spinal canal of the present invention may have at least the surface portion made of a porous ceramic having biocompatibility as described above, but the entire porous ceramic having biocompatibility may be used. It preferably comprises

[0011]

FIG. 1 shows an embodiment of a spinal canal enlargement spacer 10 according to the present invention, and FIG. 2 shows the insertion of the present spacer 10 in a laminectomy spinal canal enlargement operation. The state is shown. The spacer 10 for spinal canal enlargement is a flat part 1
1 and a pair of hooks 1 in opposite directions, respectively.
2 and 13 are formed, and have a uniform Z-shaped cross section. The spacer 10 has a rotationally symmetrical shape with respect to the cross-sectional center X of the plane portion 11 in the cross section.
That is, when the spacer 10 for spinal canal enlargement is rotated around X, not only the plane portions 11 overlap before and after rotation, but also the hook portion 13 is attached to the hook portion 12 (the hook portion 12 is attached to the hook portion 13). But)
It has a completely overlapping shape. An inner edge of the hook portion 12 (hook portion 13) protruding from the flat portion 11 forms a right-angle inner edge 12a (13a) substantially perpendicular to the flat portion 11, and an outer end portion has
An inclined outer edge 12b (13b) gradually approaching the right-angle inner edge 12a (13a) is formed. The inclined outer edge 12b (13b) corresponds to the shape of the spinal canal 20a of the vertebral body 20. The thickness of the flat portion 11 corresponds to the cutting allowance of the bone, and specifically, is preferably about 2 mm.

As described above, the spinal canal enlargement spacer 10 is made of biocompatible ceramics. Among them, glass ceramics or a Ca / P ratio of 1.0 to 2.
It is preferred to be composed of 0 calcium phosphate compound.

FIG. 2 shows a spacer 1 for the above-mentioned spinal canal enlargement.
FIG. 2 is a schematic diagram of a lamine free spinal canal enlargement using a No. 0.
A vertebral arch 22 including spinous processes 21 is cut off from a vertebral body 20 having a spinal canal 20a. Between both side surfaces of the dissected vertebral arch 22 and the remaining spinal canal (vertebral body) outer mass 23,
The spacer 10 is inserted along the cutting line (cutting margin) s. The spacer 10 is inserted upside down so as to form a line-symmetric shape with respect to the center line of the vertebral arch 22. Both the left and right spacers 10 are positioned at the inner end of the spinal canal 20a. The hook 12 (the hook 13) is separated from the vertebral arch 2
2 constitutes an inner hook portion projecting toward the center of the spinal canal 20a.
The outer hook portion is configured such that the hook portion 13 (the hook portion 12) located on the outer end side of the protruding portion protrudes in a direction away from the incision vertebral arch 22.

The right-angle inner edge 12a (13a) of the hook portion 12 (hook portion 13) located on the inside contacts and engages with both inside edges of the dissected vertebral arch 22, and the hook portion 13 (hook portion 12) located on the outside. ), The inner edges 13a (12a) of the right angles are in contact with and engaged with both outer edges of the cutting line s of the spinal canal outer mass 23, thereby preventing the spinal canal from falling off. The left and right spacers 10 and the dissected vertebrae 22 thus inserted are inserted.
And the spinal canal outer mass 23 is sutured appropriately.

The size of the spinal canal 20a that is enlarged by inserting the spinal canal enlargement spacer 10 is determined by the spacer 10
From the right-angle inner edge 12a (13a) of the hook 12 (13)
This can be changed by changing the length H that reaches the outer end of the inclined outer edge 13b (12b) along the plane portion 11.
That is, if H is reduced, the spinal canal 20a formed by the spacer 10 becomes larger, and if H is increased, it becomes relatively small. However, irrespective of the magnitude of H, the overall Z of the spinal canal enlargement spacer 10 is approximately Z.
The U-shaped uniform cross-sectional shape is maintained. H is preferably about 5 mm for the lumbar vertebra and about 3 mm for the cervical vertebra. The protrusion of the hook portion 12 (the hook portion 13) from the flat portion 11 is preferably about 1 mm in order to secure engagement with the bone.

[0016]

EFFECTS OF THE INVENTION The spacer for dilatation of the spinal canal according to the present invention is less likely to fall off from the dissected lamine and the remaining mass outside the spinal canal, thereby reducing the burden on the operator and the patient by shortening the operation time. it can. In addition, the spinal canal can be sufficiently enlarged to sufficiently remove pressure from the canal, and a strong vertebral arch can be formed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a spacer for spinal canal enlargement showing one embodiment of the present invention.

FIG. 2 is a horizontal cross-sectional view showing a state in which the spacer for spinal canal enlargement of FIG. 1 is inserted between a spinal canal (lateral mass) and an isolated lamine by a lamine free spinal canal enlargement. It is.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Spine for spinal canal enlargement 11 Plane part 12 13 Hook part 12a 13a Right angle inner edge 12b 13b Inclined outer edge 20 Vertebral body 20a Spinal canal 22 Dissecting vertebral arch 23 Outer spinal canal mass

Claims (4)

[Claims] The present invention relates to a spinal canal dilatation spacer which is separated from a spinal canal including a spinous process, and inserted and connected between both sides of the dissected vertebra and the remaining lateral spinal canal mass. In the flat part located between the side surface of the above-mentioned laminectomy and the outer mass of the spinal canal, the inner hook part protruding toward the center side of the separation lamine at the inner end side of the spinal canal of this flat part, An outer hook portion protruding in a direction away from the incised lamine on the outer end side of the spinal canal of the flat portion, wherein a spacer for spinal canal enlargement is provided. 2. The spacer according to claim 1, wherein the spacer has a uniform cross-sectional shape that is rotationally symmetric with respect to a cross-sectional center in a longitudinal direction of the plane portion, and is turned upside down so that the left and right sides of the dissected vertebral arch. A spacer for intervertebral augmentation, which is located on the side surface of the vertebrae in a line-symmetrical shape with respect to the center line of the section of the dissected lamine. 3. The spacer according to claim 1, wherein the spacer is made of biocompatible ceramics for spinal canal enlargement. 4. The spacer according to claim 3, wherein the biocompatible ceramic is glass ceramic or Ca /
A spacer for spinal canal enlargement comprising a calcium phosphate compound having a P ratio of 1.0 to 2.0.