JP3462716B2 - Spinal canal spacer - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a spacer suitable for use in vertebral canal dilation, in particular, free spinal canal dilation of the pedicle.

[0002]

2. Description of the Related Art The spinal canal (vertebral body) that encloses and protects the spinal cord includes a cervical canal in the neck, a thoracic canal in the chest, and a lumbar canal in the lumbar region. These spinal canals, for example, for diseases such as lumbar spinal canal stenosis and lumbar deformity slip, and for tumor removal,
The canal may become narrower, and spinal canal dilation is performed to widen it. This spinal canal dilation basically treats the vertebral arch of the spinal canal to dilate the vertebral canal, but laminectomy removes all the pedicle and laminoplasty without removal. The latter is further divided into the single-opening type, the spinous process longitudinal splitting type, and the pedicle release type. The free laminar method is a procedure in which a spinal process including a spinous process is separated from the spinal canal and the separated spinal process is rejoined to the spinal canal by some means.

[0003] Conventionally, in this laminoplasty type spinal canal dilatation, it has been attempted to use a biocompatible ceramic block-shaped body as a spacer (compensation material) used to secure a space. However, the conventional products cannot be said to be excellent in connectivity between the spinal canal (outer mass) and the incised vertebral arch, because they easily fall off, require a long operation time. There is also the problem of insufficient decompression in the spinal canal.

[0004]

It is an object of the present invention to provide a spacer for use in vertebral canal dilatation of the free pedicle, which is less likely to fall off the spinal canal (vertebral body) and the incised vertebral arch. The burden on the operator and the patient can be reduced, and the pressure inside the tube can be sufficiently removed.
The purpose is to obtain a spacer that can form a strong laminar formation.

[0005]

SUMMARY OF THE INVENTION The present invention provides a spinal canal dilation space that separates the pedicle containing the spinous process from the spinal canal and inserts it between the sides of the dissected laminae and the remaining lateral mass of the spinal canal. In the sa, the plane portion located between the lateral surface of the dissecting laminae and the lateral mass of the spinal canal, and the medial hook portion projecting toward the center side of the dissecting arch on the inner side of the spinal canal of this plane portion, A lateral hook portion on the outer end side of the spinal canal of the flat portion and protruding in a direction away from the incised pedicle,
It is characterized by having.

The spacer for spinal canal dilation of the present invention may be formed for each of the left and right sides of the incised laminae, but it is preferable that the spacer is rotationally symmetric with respect to the center of the cross section of the plane portion in the longitudinal direction. It is desirable to form such a cross-sectional shape and turn it upside down so that it can be positioned on the left and right sides of the incised lamina in a line symmetrical shape with respect to the cross-sectional centerline of the incised lamina.

The spacer for spinal canal dilation of the present invention is made of biocompatible ceramics. Above all, it is preferably 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-based 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 fluoroapatite, monobasic calcium phosphate, dibasic calcium phosphate, tricalcium phosphate, and phosphoric acid. Tetracalcium and the like can be mentioned, which can be used alone or as a mixture. After drying the slurry of the raw material compound, calcination at 500 to 800 ° C.
Baking at 0 to 1400 ° C., processing the obtained block-shaped body into a desired shape and size, or producing a green compact having a desired shape and size from the powder of the calcium phosphate-based compound, It can be manufactured by firing in the same manner as above.

In the present invention, at least the surface portion of the spacer for spinal canal dilation is made of biocompatible porous ceramics, so that the affinity with surrounding bone tissue is good and the bone tissue into the pores is good. Of bone promotes bone union. The porous ceramics preferably have continuous pores. The pore diameter and the 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, and usable ceramics include calcium phosphate compounds having a Ca / P ratio of 1.0 to 2.0, alumina, titania and zirconia. Among these, calcium phosphate-based compounds are preferable. The method of providing the layer of the porous biocompatible material on the surface of the central portion made of dense ceramics is not particularly limited, and any known method can be adopted, for example,
The thermal spraying method, the sputtering method, the impregnation method, the spray coating method and the like can be mentioned.

The spacer for enlarging the spinal canal of the present invention may be made of biocompatible porous ceramics at least on the surface thereof as described above, but the entire porous ceramics has biocompatibility. Preferably consisting of

[0011]

1 shows an embodiment of a spacer 10 for spinal canal dilation according to the present invention, and FIG. 2 shows insertion of the spacer 10 in a spinal canal dilation procedure of the free pedicle. It shows the state. Spacer 10 for spinal canal dilation has a flat surface 1
A pair of hooks 1 with opposite directions on both ends
2 and 13 are formed to have a uniform Z-shaped cross section. This spacer 10 has a rotationally symmetrical shape with respect to the cross-sectional center X of the flat surface portion 11 in its cross section.
That is, when the spinal canal magnifying surgery spacer 10 is rotated about X, the flat portions 11 overlap each other before and after the rotation, and the hook portions 12 and the hook portions 13 (the hook portion 13 and the hook portion 12 are overlapped with each other). But)
It has a completely overlapping shape. The protruding inner edge of the hook 12 (hook 13) from the flat surface portion 11 forms a right-angled inner edge 12a (13a) that is substantially perpendicular to the flat surface portion 11, and the outer end portion thereof is
An inclined outer edge 12b (13b) gradually approaching the right-angled 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 margin of the bone, and specifically, about 2 mm is preferable.

The spacer 10 for spinal canal dilation is made of biocompatible ceramics as described above. Among them, glass ceramics or Ca / P ratio of 1.0 to 2.
It is preferably composed of a calcium phosphate-based compound of 0.

FIG. 2 shows the spacer 1 for spinal canal dilation described above.
FIG. 3 is a schematic view of a spinal canal dilation method using a 0-type spinal arch release.
A vertebral arch 22 including a spinous process 21 is cut off from the vertebral body 20 having the spinal canal 20a. Between both side surfaces of the cut laminae 22 and the remaining lateral spinal canal (vertebral body) mass 23,
The spacer 10 is inserted along the cutting line (cut margin) s. The spacer 10 is inserted upside down so as to form a line symmetrical shape with respect to the center line of the vertebral arch 22, and both the left and right spacers 10 are located at the inner end of the spinal canal 20a. Hook part 12 (hook part 13) is a detached lamina 2
The inner hook part projecting toward the center of 2 constitutes the spinal canal 20a.
The outer hook portion is configured such that the hook portion 13 (hook portion 12) located on the outer end side of the protrusion protrudes in a direction away from the incised vertebral arch 22.

The right-angled inner edges 12a (13a) of the hooks 12 (hooks 13) located on the inner side are in contact with both inner edges of the incised lamina 22, and the hooks 13 (hooks 12 located on the outer sides). ), The right-angled inner edge 13a (12a) contacts and engages with both outer edges of the cutting line s of the outer mass 23 of the spinal canal and is prevented from falling off. The left and right spacers 10 and the incised laminae 22 thus inserted
The outer spinal canal mass 23 is appropriately sutured.

The size of the spinal canal 20a expanded by inserting the spacer 10 for spinal canal enlargement is equal to that of the spacer 10.
From the right-angled inner edge 12a (13a) of the hook portion 12 (13) of
It can be changed by changing the length H of the inclined outer edge 13b (12b) along the plane portion 11 to the outer end portion.
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, regardless of the size of H, the overall space of the spinal canal dilation spacer 10 is approximately Z.
The V-shaped uniform cross-sectional shape is maintained. The standard value of H is about 5 mm for the lumbar spine and about 3 mm for the cervical spine. The amount of protrusion of the hook portion 12 (hook portion 13) from the flat surface portion 11 is preferably about 1 mm in order to secure the engagement with the bone.

[0016]

The spacer for magnifying the spinal canal of the present invention is less likely to fall off from the incised pedicle and the remaining outer mass of the spinal canal, reducing the burden on the operator and the patient through shortening the operation time. it can. Further, the spinal canal can be sufficiently expanded to sufficiently decompress the inside of the canal, and a strong vertebral arch can be formed.

[Brief description of drawings]

FIG. 1 is a perspective view of a spinal canal dilatation spacer according to an embodiment of the present invention.

FIG. 2 is a horizontal cross-sectional view showing a state in which the spacer for spinal canal dilation of FIG. 1 is inserted between the spinal canal (outer mass) and the incised laminae by the spinal canal dilation of the pedicle free type. Is.

[Explanation of symbols]

10 Spacer for spinal canal dilation 11 Plane 12 13 Hook 12a 13a Right angle inner edge 12b 13b Inclined outer edge 20 vertebral bodies 20a spinal canal 22 Separated arch 23 lateral spinal canal

Continuation of the front page (56) Reference JP-A-5-103801 (JP, A) JP-A-10-179622 (JP, A) Actual opening 2-104019 (JP, U) Actual opening 6-38936 (JP , U) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61F 2/44 A61B 17/56

Claims (4)

(57) [Claims] 1. A spinal canal dilation spacer which separates a pedicle containing a spinous process from a spinal canal and inserts and joins between both side surfaces of the dissected laminae and the remaining outer mass of the spinal canal. In, a flat surface portion located between the lateral surface of the dissected laminae and the lateral mass of the spinal canal, and an inner hook portion projecting toward the central side of the dissected laminae at the inner end side of the spinal canal of this flat surface portion, A spacer for vertebral canal dilation surgery, comprising: 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 pedicle. 2. The spacer according to claim 1, wherein a flat cross-section has a uniform cross-sectional shape that is rotationally symmetric with respect to a cross-sectional center in the lengthwise direction, and the top and bottom are inverted so that the left and right of the incised laminae are inverted. A spacer for intervertebral dilation which is located on the lateral surface of the vertebral body in a line-symmetrical shape with respect to the cross-section centerline of the incised laminae. 3. The spacer according to claim 1 or 2, which is made of biocompatible ceramics and is used for spinal canal dilation. 4. The spacer according to claim 3, wherein the biocompatible ceramic is glass ceramic or Ca /
A spacer for spinal canal dilatation consisting of a calcium phosphate compound having a P ratio of 1.0 to 2.0.