JP2001079024A - Vertebral-arch spacer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertebral-arch spacer which securely re-fixes a vertebral arch which has been amputated and separated in osteogenetic vertebral canal dilation operations, etc. SOLUTION: A vertebral-arch spacer 1A possesses an insertion part 2A which is inserted into the amputated part of the vertebral arch, a first projection part 4 and a second projection part 5 which are formed as monolithic flanges on the insertion part 2A, and a penetrating hole 6A formed on the insertion part 2A. In the vertebral arch spacer 1A, the line L1 which links the peaks of the first projection part 4 and the second projection part 5 is tilted against the normal L2 of a first approximal surface 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lamine spacer.

[0002]

2. Description of the Related Art Generally, as one of surgical procedures for spinal diseases such as spinal canal stenosis and ossification of the posterior longitudinal ligament, there is a technique called osteogenic spinal canal enlargement. This is a method of enlarging a stenotic or deformed spinal canal by dividing a part of a vertebra and then reshaping the vertebra using a bone filling material such as a spacer.

FIG. 7 is a view showing a state in which a vertebra is reformed using a conventional spacer. As shown in the figure, the spacer 100 has a bead shape. The spacer 100 is used by being inserted into a cut portion of the vertebral arch 91.

[0004] However, the spinous process lumbar 911 re-immobilized after osteogenic spinal canal enlargement was not stable. This is a spacer 1 having a shape as shown in FIG.
When 00 is used, the fixing is performed only by the thread 92, and the fixing using the fixing plate cannot be performed.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lamine spacer which can reliably re-fix a lamine which has been cut and separated by osteogenic spinal canal enlargement or the like.

[0006]

This and other objects are achieved by the present invention which is defined below as (1) to (12).

(1) A lamine spacer which is used by being installed at a cut portion formed by cutting a vertebra, wherein an insertion portion is inserted into the cut portion of the vertebra, and The insertion portion is wider than the insertion portion and has a widened portion that engages with the vertebral arch. The planar shape of the insertion portion has a substantially square shape, and the lamine spacer is installed on the affected part. The lamine spacer is characterized in that the surface that will be located on the outer surface side of the vertebrae when inclined is inclined with respect to the normal line of the surface that abuts the cut surface of the vertebral side. As a result, the vertebrae that have been cut and separated by the osteogenic spinal canal enlargement or the like can be securely fixed to the vertebrae.

(2) The lamine spacer according to (1), wherein the widened portion has a protrusion that engages at least one of a vertebral arch or a spinous process vertebra. As a result, the vertebral arch cut and separated by osteogenic spinal canal enlargement or the like can be stably and reliably re-fixed to the vertebra.

(3) A lamine spacer used by being installed on a cut portion formed by cutting a vertebra, wherein an interposition portion inserted into the cut portion of the vertebra and a vertebra on the vertebrae side are provided. And a second protrusion engaging with a spinal process-side vertebral arch cut and separated from the vertebrae, wherein the planar shape of the insertion portion is substantially square. And a side surface corresponding to a pair of opposing sides of a quadrilateral is a first contact surface that abuts a cut surface of the vertebral arch on the vertebral side, and a vertebra cut and separated from the vertebrae, respectively. A second abutment surface that abuts on a cutting surface of the bow is formed, and a line connecting the top of the first projection and the top of the second projection is a line of the first abutment surface. A lamine spacer characterized by being inclined with respect to the normal. As a result, the vertebral arch cut and separated by osteogenic spinal canal enlargement or the like can be re-fixed to the vertebrae in a stable and reliable manner.

(4) The first protrusion is formed at an end of the first contact surface so as to be continuous with the first contact surface, and the second protrusion is formed by the second protrusion. The lamine spacer according to the above (3), which is formed at an end of the second contact surface so as to protrude continuously from the second contact surface. In this way, the vertebrae cut and separated by osteogenic spinal canal enlargement, etc.
Further, it is possible to stably and surely fix again.

(5) The lamine spacer according to (3) or (4), wherein the first contact surface and the second contact surface are substantially parallel. As a result, it is possible to prevent a local load from being applied to the lamine and the lamine spacer, and it is possible to suitably prevent damage to the lamine and the lamine spacer.

(6) The lamine spacer according to any one of the above (1) to (5), wherein the insertion portion is provided with fixing means for fixing the lamine spacer to an affected part. This facilitates the fixation of the lamine spacer to the cut portion of the lamine.

(7) The lamine spacer according to (6), wherein the fixing means is a through hole. This makes it easier to fix the lamine spacer to the cut part of the lamine.

(8) The lamine spacer according to any one of the above (1) to (7), comprising a ceramic material as a constituent material. Thereby, a lamine spacer excellent in workability can be obtained.

(9) The lamine spacer according to (8), wherein the ceramic material comprises a calcium phosphate compound. Thus, a lamine spacer having excellent biocompatibility can be obtained.

(10) The lamine spacer according to (9), wherein the calcium phosphate compound has a Ca / P ratio of 1.0 to 2.0. Thereby, a lamine spacer having more excellent biocompatibility can be obtained.

(11) The above (9) or (1), wherein the calcium phosphate compound is hydroxyapatite.
The lamine spacer according to 0). This makes it possible to obtain a lamine spacer having particularly excellent biocompatibility.

(12) The porosity of the ceramic is 0
The lamine spacer according to any one of the above (8) to (11), which is 70% or less. This promotes the fusion of the lamine spacer to the bone tissue.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings. FIG. 1 is a perspective view showing a first embodiment of a lamine spacer according to the present invention.
FIG. 2 is a plan view of the lamine spacer shown in FIG.

As shown in these figures, a lamine spacer 1A is formed adjacent to an insertion portion 2A inserted into a cut portion of a vertebra, and is wider than the insertion portion 2A. And a through-hole 6A formed in the insertion portion 2A. The widened portion 7 has a first protruding portion 4 and a second protruding portion 5.

The lamine spacer 1A is inserted and installed in a cut part (affected part) 115 of the lamine 11 formed by cutting the lamine 11 by osteogenic spinal canal enlargement or the like (FIG. 3, FIG. 3). (See FIG. 4). Hereinafter, for convenience of explanation, of the cut vertebrae 11, the vertebrae 11 on the vertebra 10 (vertebral body) side are the vertebral side vertebrae 111, and the vertebrae 11 on the spinous process 12 side separated from the vertebrae 10 are the spine. It is referred to as the process side lamine 112. The cut surface of the vertebral-side lamine 111 is called a vertebra-side cut surface 116, and the cut surface of the spinous process-side lamine 112 is called a spinous process-side cut surface 117.

The insertion portion 2A is a portion that forms a main portion of the lamine spacer 1A. The insertion portion 2A has a substantially trapezoidal (square) shape in plan view, and has a constant length L. In the insertion portion 2A, end surfaces forming a pair of parallel sides of a trapezoid in plan view abut on the vertebra-side cut surface 116 and the spinous process-side cut surface 117, respectively. Of the end surfaces of the insertion portion 2A, the end surface that contacts the vertebra-side cut surface 116 is the first contact surface 2A.
1 and an end surface that abuts on the spinous process side cut surface 117 is referred to as a second abutment surface 22.

Hereinafter, for convenience of explanation, the lamine spacer 1A will be described.
The spinal canal 1
The end face of the insertion portion 2A located on the third side (the inner surface side of the lamine 11, that is, the center of the human body) is located on the distal end face 24 and the side opposite to the spinal canal 13 (the outer surface side of the lamine 11, that is, the body surface side). The end face of the inserted portion 2A is referred to as a base end face 23. The distal end surface 24 and the proximal end surface 23 are inclined at a predetermined angle with respect to the normal L2 of the first contact surface 21 (are non-parallel), and the distance between the distal end surface 24 and the proximal end surface 23 is the first contact surface. It gradually decreases from the contact surface 21 side to the second contact surface 22 side. As a result, when the lamine spacer 1A is placed on the cutting portion 115, the inner surface, the distal end surface 24, and the spinous process side lamine 1 of the vertebral lamine 111 are removed.
The inner surface of 12 is close to a continuous surface (continuous shape). A widened portion 7 is formed integrally with the insertion portion 2A at an end of the insertion portion 2A on the base end surface 23 side. Such widening portion 7
, A first protrusion 4 and a second protrusion 5 are formed.

The first protruding portion 4 is formed so as to protrude adjacent to an end of the first contact surface 21 on the base end surface 23 side, and can be engaged with the vertebral vertebral arch 111. This first protrusion 4
It has a convex curved surface, and the cross-sectional area of the first projection 4 near the tip of the first projection 4 gradually decreases toward the tip.

The first projection 4 has a shape that is continuous with the first contact surface 21. That is, the side surface 41 of the first protrusion 4 forms a surface that is continuous with the first contact surface 21.
Therefore, the boundary portion 42 between the side surface 41 and the first contact surface 21
Is rounded (with R). The distal side surface 411 of the side surface 41 abuts on a corner or the outer surface of the vertebral lamine 111 near the vertebral cut surface 116.
In addition, the side surface 41 of the first protrusion 4 forms a surface that is continuous with the base end surface 23. As a result, the strength of the lamine spacer 1A is improved, and chipping or the like is suitably prevented.

The length of the first protrusion 4 (the length in the direction perpendicular to the plane of the paper in FIG. 2) and the length L of the insertion portion 2A are substantially the same. For this reason, the upper surface 25 of the insertion portion 2A and the upper surface 43 of the first protrusion 4 are located on the same plane. Similarly, the bottom surface 26 of the insertion portion 2A and the bottom surface 44 of the first protrusion 4 are located on the same plane.

The second protrusion 5 is formed so as to protrude adjacent to the end of the second contact surface 22 on the base end surface 23 side, and can engage with the spinous process side vertebral arch 112. This second protrusion 5
Has a convex curved surface, and the cross-sectional area of the second protrusion 5 near the tip of the second protrusion 5 gradually decreases toward the tip.

The second protrusion 5 has a shape that is continuous with the second contact surface 22. That is, the side surface 51 of the second protrusion 5 forms a surface that is continuous with the second contact surface 22.
Therefore, the boundary 52 between the side surface 51 and the second contact surface 22
Is rounded (with R). The distal side surface 511 of the side surface 51 abuts on the corner or lateral surface of the spinous process side vertebral arch 112 near the spinous process side cut surface 117. In addition, the side surface 51 of the second protrusion 5 is a surface that is continuous with the base end surface 23. Thereby, the lamine spacer 1
The strength of A is improved, and chipping or the like is suitably prevented.

The length of the second protruding portion 5 (the length in the direction perpendicular to the paper surface of FIG. 2) and the length L of the insertion portion 2A are substantially the same. For this reason, the upper surface 25 of the insertion portion 2A and the upper surface 53 of the second projecting portion 5 are located on the same plane. Similarly, the bottom surface 26 of the insertion portion 2A and the bottom surface 54 of the second projecting portion 5 are located on the same plane.

It is preferable that the planar shape of the first projecting portion 4 (plan view shape) and the planar shape of the second projecting portion 5 are different. As a result, the shapes of the first projection 4 and the second projection 5 are changed to the vertebral-side vertebral arch 111 and the spinous process-side vertebral arch 112.
, Respectively, can be suitable.

In such a lamine spacer 1A, the first
Line L1 connecting the top of the protrusion 4 and the top of the second protrusion 5
Is inclined at a predetermined angle with respect to the normal L2 of the first contact surface 21 (the base end surface 23 is also inclined at a predetermined angle with respect to the normal L2). Such a lamine spacer 1A is
1, for example, the line L <b> 1 (and the proximal end surface 23) substantially coincides with the longitudinal direction of the vertebral arch 11 (substantially parallel to the outer surface of the vertebral arch 11), and the first abutment surface 21.
The second contact surface 22 is inclined at a predetermined angle from the cross section of the vertebral arch 11.

The angle α between the line L1 and the normal L2 (or the angle between the base end face 23 and the normal L2) is 1 to 80.
Degree is preferable, and about 10-45 degree is preferable. As a result, the effects described later can be more effectively obtained.

The insertion portion 2A penetrates from the upper surface 25 to the bottom surface 26 of the insertion portion 2A at a position near the base end surface 23 near an intermediate portion between the first contact surface 21 and the second contact surface 22. A through-hole (fixing means) 6A is formed. The cross-sectional shape of the through hole 6A is, for example, circular. By inserting a thread (linear body) or the like into the through hole 6A, for example, as shown in FIG.
4. As shown in FIG.
9 can be fixed. As a result, the lamine spacer 1A is securely installed and fixed to the cut portion (operative portion) 115 of the lamine 11. Note that a plurality of through holes 6A may be provided. In this case, each hole is preferably formed along a direction parallel to the line L1. Thereby, it becomes possible to fix the lamine spacer 1A more stably.

In the insertion portion 2A, the 2
One corner is chamfered. That is, the first contact surface 21 and the distal end surface 24 form a continuous surface.
The contact surface 22 and the tip surface 24 form a continuous surface. Thereby, in the lamine spacer 1A, the chipping of the corners is suitably prevented.

The width of the lamine spacer 1A (first contact surface 21)
W, thickness (average distance from the base end surface 23 to the distal end surface 25) T, length L, and the size of the first protrusion 4 and the second protrusion 5 (the distance between the first protrusion 4 and the second protrusion 5). The height) is appropriately determined according to the patient's case and the like. For example, when the patient suffers from ossification of the posterior longitudinal ligament and needs to greatly expand the spinal canal, the width W of the lamine spacer 1A is made relatively large. Also, for example, in the case of treatment of a spinal cord tumor, the width W of the lamine spacer 1A may be relatively small.

It is preferable that such a lamine spacer 1A be made of a ceramic material. Since the ceramic material is excellent in workability, it is easy to adjust the shape, size, and the like by cutting using a lathe, a drill, or the like.

Examples of the ceramic material include various ceramic materials, and bioceramics such as alumina, zirconia, and calcium phosphate are particularly preferable. Among them, a calcium phosphate compound has excellent biocompatibility, so that the lamine spacer 1A
Is particularly preferred as a constituent material of

Examples of the calcium phosphate compound include apatites such as hydroxyapatite, fluorapatite, and carbonate apatite, dicalcium phosphate, tricalcium phosphate, tetracalcium phosphate, and octacalcium phosphate. Species or a mixture of two or more can be used. Among these calcium phosphate compounds, those having a Ca / P ratio of 1.0 to 2.0 are preferably used.

Of these calcium phosphate compounds, hydroxyapatite is more preferred. Hydroxyapatite has an excellent biocompatibility because it has a structure similar to that of the inorganic main component of bone. When producing the lamine spacer 1A, the hydroxyapatite particles as the raw material are more preferably calcined at 500 to 1000 ° C. The activity of the hydroxyapatite particles calcined at such a temperature is suppressed to some extent, so that sintering unevenness due to rapid progress of sintering or the like is suppressed, and a sintered body having no unevenness in strength can be obtained.

In the present invention, the porosity of the ceramic is 0 to 0.
It is preferably 70%, more preferably 30 to 50%. By setting the porosity in this range, good biocompatibility can be exhibited while maintaining strength, and osteogenesis due to osteoconduction can be promoted.

As a constituent material of the lamine spacer 1A of the present invention, in addition to the above-mentioned ceramic material, a composite material of the ceramic material and a metal material having low biological harm such as titanium can be used.

Such a lamine spacer 1A is applied to a general surgical technique such as osteogenic spinal canal enlargement.
An example of the osteogenic spinal canal enlargement operation will be described below in detail with reference to FIGS. The following operation involves two vertebrae 1
1, respectively (see FIG. 3).

First, the vertebral arch 11 is cut at a position close to the vertebra 10, and the vertebral arch 11 on the spinous process 12 side, that is, the spinous process side vertebral arch 112 is separated. At this time, the vertebra-side cut surface 116 and the spinous process-side cut surface 117 are shaped as necessary. Next, the lamine spacer 1A is installed in the cut portion 115 of the lamine 11. At this time, the first contact surface 21 is connected to the vertebra-side cut surface 11.
6 and the first protrusion 4 is engaged with the vertebral side vertebral arch 111. At this time, the lamine spacer 1A is positioned such that the distal end surface 25 is located on the side of the spinal canal 17 (the center of the body).
Is installed.

Next, the spinous process side cut surface 117 is brought into contact with the second contact surface 22, and the second protrusion 5 is attached to the spinous process side vertebral arch 1.
12, and the separated spinous process side vertebral arch 112 is placed in the body again. As a result, the cutting portion 115 of the lamine
In other words, the vertebral lamine 111 and the spinous process lamine 112
And the lamine spacer 1A is interposed and installed.

Next, the fixing plate 19 is applied to the cut portion 115 of the vertebral arch 11 from the body surface side, and the fixing plate 19 is screwed to the vertebral arch 11 with screws 191. Further, a thread (linear body) 17 is passed through the through hole 6A, and the lamine spacer 1A
Is fixed to the fixing plate 19 and fixed. As a result, the lamine spacer 1A is securely installed and fixed to the affected part.

As shown in FIGS. 3 and 4, the first contact surface 21 and the vertebra-side cut surface 116, and the second contact surface 22 and the spinous process-side cut surface 117 are in surface contact with each other. And the first
The protrusion 4 engages with the vertebral lamine 111, and the second protrusion 5 engages with the spinous process lamine 112. For this reason, according to the present invention, the spinous process lamine 1 is provided via the lamine spacer 1A.
12 can be securely fixed to the vertebra 10. Moreover, since the first protrusion 4 is engaged with the vertebral lamine 111 and the second protrusion 5 is engaged with the spinous process lamine 112, respectively, Is properly prevented from shifting.

Furthermore, in the lamine spacer 1A, the first
The contact surface 21 and the second contact surface 22 are inclined at a predetermined angle from the cross section of the vertebral arch 11. For this reason, the first contact surface 21
And the contact area between the vertebra-side cut surface 116 and the second contact surface 22 and the spinous process-side cut surface 117 are increased,
The fixation of the spinous process side lamine 112 is more secure.

In addition, according to the lamine spacer 1A of the present invention, the contact area between the first contact surface 21 and the vertebra-side cut surface 116, and the contact between the second contact surface 22 and the spinous process-side cut surface 117. Since the area increases and the lamine spacer 1A hardly shifts at the affected part, the fixing plate 19 can be used. As a result, the spinous process side vertebral arch 112 is more reliably fixed to the vertebra 10. In addition to this, according to the present invention, the lamine spacer 1A can be securely fixed to the fixing plate 19. Therefore, the lamine spacer 1
A fixation stability of A is increased, and concomitantly
The stability of the fixation of 12 is also increased.

In addition, the first contact surface 21 and the second contact surface 22
When the external force is applied from the spinous process 12 side to the vertebra 10 side, the external force is uniformly applied to the entire second contact surface 22 and first contact surface 21 of the lamine spacer 1A. To join. For this reason, it is prevented that a high load is locally applied to the vertebra 11 or a part of the lamine spacer 1A.

Since the lamine spacer 1A of the present invention has the above advantages, the lamine spacer 1A of the present invention is provided.
When osteogenic spinal canal enlargement is performed using, the vertebrae that have been cut and re-fixed will maintain fixation reliably after surgery and have high stability. Thus, according to the present invention, after surgery, the patient's lamine is reliably fixed for a long period of time.

FIG. 5 is a perspective view showing a second embodiment of the lamine spacer of the present invention. FIG. 6 is a plan view of the lamine spacer shown in FIG. Hereinafter, the lamine spacer 1B will be described focusing on the differences from the lamine spacer 1A.

The insertion portion 2B of the lamine spacer 1B has a substantially parallelogram (square) in plan view.
4 and the base end surface 23 are inclined at a predetermined angle with respect to the normal line of the first contact surface 21. Near the center of the insertion portion 2B,
A through hole (fixing means) 6B penetrating from the upper surface 25 to the bottom surface 26 of the insertion portion 2B is formed. The cross-sectional shape of the through hole 6B is, for example, elliptical.

[0053]

EXAMPLE A hydroxyapatite slurry (Ca / P ratio = 1.67) was prepared from a calcium hydroxide slurry and a phosphoric acid aqueous solution by a known wet synthesis method. This was dried by a spray heat drying method, and then calcined at 700 ° C. in an atmospheric furnace to obtain a spherical powder. Next, the obtained spherical powder of hydroxyapatite and an aqueous solution of a polymer compound were mixed and stirred, and the mixture was dried to obtain a block of hydroxyapatite.

From this block, the shrinkage after sintering was calculated, and a lath, a drill or the like was used to produce a molded body having a desired lamine spacer shape. Put this molded body in an electric furnace,
By sintering at 200 ° C. for 4 hours, FIGS.
Lamine spacers of various shapes shown in FIG. 6 were produced.

The lamine spacer manufactured in this embodiment is:
Width W: 2.6 mm, length L: 6 mm, thickness T: 4.5 mm, height of the first protrusion: 1.3 mm, height of the second protrusion: 1.3
mm, angle α (and angle between base end face and normal L2): 3
0 °. The porosity of hydroxyapatite was 40%.

Using these lamine spacers, osteogenic spinal canal enlargement was performed on several patients with spinal canal stenosis in the manner described above.

As a result, the spinal canal that had been stenotic in all patients could be enlarged to a shape similar to a normal spinal canal. In addition, the operation of resecuring the cut and separated vertebrae during the operation can be easily performed, and the operation time can be greatly reduced. The postoperative course was good, and even after a long time after the operation, no displacement of the vertebral arch or the vertebral arch spacer was confirmed, and the spinal canal maintained a good enlarged state. In addition, the lamine spacer quickly fused with the vertebral arch, the physiological reconstruction was performed extremely well, and nerve root palsy and kyphosis were not confirmed.

[0058]

As described above, according to the present invention, osteogenic spinal canal enlargement can be performed smoothly. Further, according to the present invention, it becomes possible to stably and reliably re-fix a vertebra, which has been cut and separated by osteogenic spinal canal enlargement or the like, to a vertebra.

Therefore, it is possible to reliably perform an osteogenic spinal canal enlargement and the like, and to more reliably treat a spinal disease patient such as spinal canal stenosis and ossification of the posterior longitudinal ligament. In addition, the patient can maintain a good condition after the operation, and the complications caused by the displacement of the vertebral arch and the vertebral arch spacer can be suitably suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a lamine spacer according to the present invention.

FIG. 2 is a plan view of the lamine spacer shown in FIG.

FIG. 3 is a view showing a use state of the lamine spacer of the present invention.

FIG. 4 is an enlarged view of the vicinity of a cut portion of the vertebra shown in FIG. 3;

FIG. 5 is a perspective view showing a second embodiment of a lamine spacer according to the present invention.

6 is a plan view of the lamine spacer shown in FIG.

FIG. 7 is a view showing a use state of a conventional spacer.

[Explanation of symbols]

 1A, 1B Lumbar spacer 2A, 2B Interposed part 21 First contact surface 22 Second contact surface 23 Base end surface 24 Tip surface 25 Top surface 26 Bottom surface 4 First protrusion 41 Side surface 411 Front side surface 42 Boundary portion 43 Top surface 44 bottom surface 5 second protruding portion 51 side surface 511 distal side surface 52 boundary portion 53 top surface 54 bottom surface 6A, 6B through-hole 7 widening portion 10 vertebra 11 vertebral arch 111 vertebral vertebral arch 112 spinous process vertebral arch 115 cutting portion 116 vertebral side Cut surface 117 Spinous process side cut surface 12 Spinous process 13 Spinal canal 17 Thread 19 Fixing plate 191 Screw L1 Line L2 Normal α Angle L Length T Thickness W Width 100 Spacer 91 Laminerium 911 Spine lamineus 92 Thread

Claims (12)

[Claims] 1. A lamine spacer which is used by being installed at a cut portion formed by cutting a vertebra, wherein an interposition portion is inserted into the cut portion of the vertebra, and is adjacent to the interposition portion. The insertion part is wider than the insertion part and has a widened part that engages with the vertebral arch. The planar shape of the insertion part is substantially square, and the lamine spacer is installed at the affected part. A lamine spacer which is characterized in that the surface which is sometimes located on the outer surface side of the vertebra is inclined with respect to the normal to the surface abutting the cut surface of the vertebral side. 2. The lamine spacer according to claim 1, wherein the widened portion has a protrusion that engages at least one of a vertebral arch or a spinous process arch. 3. A lamine spacer used by being installed at a cut portion formed by cutting a vertebra, wherein an interposition portion inserted into the cut portion of the vertebra and a vertebra-side vertebra are provided. A first protruding portion to be engaged; and a second protruding portion to be engaged with a vertebral arch on a spinous process cut and separated from a vertebra. The planar shape of the insertion portion has a substantially square shape. A first abutting surface having side surfaces corresponding to a pair of opposing sides of a square abutting on a cut surface of the vertebrae-side vertebra, respectively, and a vertebrae cut and separated from the vertebrae A second abutting surface that abuts the cut surface of the first projection, and a line connecting the top of the first projection and the top of the second projection is a modulus of the first abutment. A lamine spacer characterized by being inclined with respect to a line. 4. The first projection is formed at an end of the first contact surface so as to be continuous with the first contact surface,
4. The lamine spacer according to claim 3, wherein the second protrusion is formed at an end of the second contact surface so as to be continuous with the second contact surface. 5. 5. The first contact surface and the second contact surface,
The lamine spacer according to claim 3 or 4, which is substantially parallel. 6. The lamine spacer according to claim 1, wherein the insertion portion is provided with fixing means for fixing the lamine spacer to an affected part. 7. The fixing means according to claim 6, wherein said fixing means is a through hole.
5. The lamine spacer according to claim 1. 8. The lamine spacer according to claim 1, wherein the constituent material is a ceramic material. 9. The lamine spacer according to claim 8, wherein the ceramic material comprises a calcium phosphate compound. 10. The calcium phosphate compound is Ca
The lamine spacer according to claim 9, wherein the / P ratio is 1.0 to 2.0. 11. The lamine spacer according to claim 9, wherein the calcium phosphate compound is hydroxyapatite. 12. The ceramic having a porosity of 0 to 70.
%. The lamine spacer according to claim 8, wherein