JP2561401B2 - Metal artificial vertebral body - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal artificial vertebral body used as a substitute for a lesioned vertebral body in the medical field of orthopedics.

[0002]

2. Description of the Related Art When a lesion or abnormality occurs in a vertebral body such as a cervical vertebra, a thoracic spine, or a lumbar spine, which is a main constituent of a spinal column, the lesioned vertebral body is conventionally excised by an operation, and an artificial vertebral body is inserted as a substitute. The healthy vertebral bodies are connected to each other through the artificial vertebral bodies. As such an artificial vertebral body, conventionally,
For example, the ceramics sintered bodies shown in FIGS. 12 and 13 are mainly used. In the figure, reference numeral 11 denotes an artificial vertebral body made of a ceramic sintered body, which is inserted and arranged in a portion where the lesion vertebral body is removed to connect the healthy vertebral bodies 12, 12. In the case of FIG. 12, the artificial vertebral body 11 is integrated with the upper and lower healthy vertebral bodies 12, 12 by using the connecting rod 13 and the bolt 14. In the case of FIG. 13, the healthy vertebral body 1
2 is provided with a recess 12a, and the artificial vertebral body 11 is formed in the recess 12a.
Both ends 11a of the artificial vertebral body 11 are inserted.
The artificial vertebral body 11 is integrated with the healthy vertebral body 12 by filling the adhesive filling opening 11b and the recess 12a with the bone cement 15.

[0003]

However, in the case of the above-mentioned conventional artificial vertebral body, it is necessary to prepare a large number of artificial vertebral bodies having different sizes. That is, the normal height of the vertebral body (normal interval between healthy vertebral bodies) is unknown until the actual surgery is performed, and the normal height of the vertebral body varies depending on individual differences among patients. It is necessary to prepare several tens of different artificial vertebral bodies, which is a problem in that it is troublesome in manufacturing and management. Further, since it is made of ceramics, there is a problem that it is easily broken during handling.

The present invention has been made in view of the above conventional problems, and an object thereof is to provide an artificial vertebral body capable of treating all vertebral bodies with a small number and not cracking during handling or use. I am trying.

[0005]

SUMMARY OF THE INVENTION The present invention is a metallic artificial vertebral body for connecting adjacent healthy vertebral bodies placed in a portion where a vertebral body having a lesion is removed, and a tubular outer vertebral canal. And a tubular inner vertebral canal whose axial length is variably inserted into the outer vertebral canal, and the side walls of the outer vertebral canal and the inner vertebral canal are filled with an adhesive that communicates with the inside of the canal. The opening is formed, and the end wall is formed with an embedding portion having a notch-shaped escape portion in side view, which communicates with the inside of the cylinder. Here, as the structure that makes the axial length variable in the present invention, for example, as described in claim 2, a structure in which the inner vertebral canal is screwed into the outer vertebral canal can be adopted. Further, as the metal for the artificial vertebral body, a metal that is harmless in the living body or has little harm is used. For example, stainless steel, Co-Cr alloys, pure titanium and titanium-based alloys, pure zirconium and zirconium-based alloys, pure tantalum and tantalum-based alloys are suitable.

[0006]

In order to connect healthy vertebral bodies using the metal artificial vertebral bodies according to the present invention, the lesion vertebral bodies are surgically removed, and the height of the artificial vertebral bodies is adjusted to a normal interval between the healthy vertebral bodies. The artificial vertebral body and the healthy vertebral body are set so that the embedded portion is inserted into the concave portion of the adjacent healthy vertebral body at a position where the lesioned vertebral body between the healthy vertebral bodies is removed. And are fixed with an adhesive such as bone cement. As described above, the artificial vertebral body of the present invention has a structure capable of adjusting the height thereof, and therefore, in actual surgery, the artificial vertebral body can be adjusted to a height corresponding to a normal interval between healthy vertebral bodies. And as a result,
A small number of artificial vertebral bodies can handle all vertebral bodies with individual differences. Further, the artificial vertebral body can be set only by inserting the embedded portion into the concave portion of the adjacent healthy vertebral body, and the operation time can be shortened as compared with, for example, fixing with a pin or the like. Further, since the adhesive is locked in the notch-shaped relief portion, the artificial vertebral body is prevented from turning, and the presence of the embedded portion itself prevents the artificial vertebral body from being displaced or dropped. Moreover, since the artificial vertebral body of the present invention is made of metal, there is no risk of cracking during handling or use.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 8 are views for explaining a metal artificial vertebral body according to a first embodiment of the present invention. In FIG. 1, 1
Is an artificial vertebral body made of stainless steel, for example,
This is the outer vertebra 2 and the inner vertebra 3 screwed into it.
It consists of and. The outer vertebral cylinder 2 is formed by integrally forming an embedded portion 2b having a smaller diameter than the upper surface of a cylindrical main body portion 2a, and a step 2c serving as a positioning stopper at the time of attachment between living body vertebral bodies at a boundary between the both portions. Are formed. A pair of arc-shaped escape portions 2d are cut out in the side wall of the embedded portion 2b. A female screw 2 is provided on the inner surface of the main body 2a.
e is formed, and a U-shaped slit-shaped outer opening 2f for filling the adhesive is formed on the side wall thereof.

The inner vertebral cylinder 3 is formed by integrally forming an embedding portion 3b having a slightly smaller diameter than the lower surface of a cylindrical main body portion 3a, and a flange portion 3c is formed at the boundary between the both portions. The lower surface of the flange portion 3c shown in the figure serves as a positioning stopper. A pair of arc-shaped escape portions 3d are cut out on the side wall of the embedded portion 3b. A male screw 3e is formed on the outer surface of the main body 3a, and a U-shaped slit-shaped inner opening 3f for filling the adhesive is formed on the side wall thereof. The outer opening 2f and the inner opening 3f do not necessarily have to be slit-shaped, and any shape, size, or the like may be used as long as the adhesive can be filled.

Here, the artificial vertebral body 1 of the present embodiment is for cervical spine,
It can be used for both thoracic and lumbar vertebrae and lumbar vertebrae, and its diameter and height adjustment ranges are set as follows. For the cervical spine, the diameter is 17 mm and the height is 19 to 30 mm. For the thoracic lumbar spine, the diameter is 23 mm and the height is 30 to 45 mm. For the lumbar spine, the diameter is 26 mm and the height is 40 to 60 mm.

Next, the function and effect of this embodiment will be described. In order to treat the lesioned vertebral body portion using the artificial vertebral body 1 of the present embodiment, as shown in FIG. 8, the lesioned vertebral body 7 having the lesioned portion 7a is surgically excised, and healthy vertebral bodies 8, 8 are obtained. A normal interval between them is measured, and a joint recess 8a is formed in the healthy vertebral body 8 (see FIGS. 8A and 8B). Next, the screwing amount of the inner vertebral body 3 is adjusted so that the dimension between the lower surface of the step 2c of the artificial vertebral body 1 to the lower surface of the flange portion 3c becomes the normal interval between the sound vertebral bodies 8, 8, and this is embedded in the embedding portion 2b 3b is set between the healthy vertebral bodies 8 and 8 so that 3b is inserted in the above-mentioned joint recess 8a (see FIG. 8 (c)). In this case, the outer opening 2f of the outer vertebral canal 2 and the inner opening 3f of the inner vertebral canal 3 do not necessarily have to be exactly aligned as shown in the drawing, but may be aligned to such an extent that the filling of the adhesive is not hindered. good. Finally, bone cement 9 as an adhesive is filled from the outer and inner openings 2f and 3f of the artificial vertebral body 1 to the inside of the artificial vertebral body 1 and the joint recessed portion 8a of the healthy vertebral body 8 (Fig. 8 ( d)).

As described above, in this embodiment, since the artificial vertebral body 1 is composed of the outer vertebral body 2 and the inner vertebral body 3 screwed into the outer vertebral body 2, the height of the artificial vertebral body 1 is set to the healthy vertebral bodies 8, 8. It can be adjusted according to the normal interval between them, therefore, by preparing a small number of artificial vertebral bodies 1 of different sizes, it is possible to handle all vertebral bodies, and the quantity to be prepared is smaller than that of conventional artificial vertebral bodies. It is easy to manufacture and manage. In addition, the embedded portion 2b,
The artificial vertebral body 1 can be set only by inserting 3b into the concave portion 8a of the adjacent healthy vertebral body 8, and the operation time can be shortened as compared with, for example, fixing with artificial pins. Notch-shaped relief 2
By locking the adhesive 9 to d and 3d, the artificial vertebral body 1 can be prevented from turning, and the presence of the embedded portions 2b and 3b can prevent the artificial vertebral body 1 from slipping and falling off. Further, since the artificial vertebral body 1 is made of metal, there is no problem of cracking during handling unlike the conventional ceramic sintered body.

9 to 11 are views for explaining the second embodiment of the present invention. This embodiment is an example in which an artificial vertebral body is composed of three parts. In the figure, 11 is an artificial vertebral body composed of an outer vertebral canal 12 and a pair of inner vertebral canals 13, 13 '. The outer vertebral cylinder 12 has an outer opening 12b formed in a main body 12a formed of an octagonal cylinder, and has a left female screw 1 on the inner surface.
2c and a right female screw 12d are formed. Further, the inner vertebral cylinders 13 and 13 'are formed by integrally forming an embedding portion 13b having a slightly smaller diameter than the end surface of a cylindrical body portion 13a, and an octagonal flange portion 13c is formed at the boundary between the both portions. The side surface of the embedded portion 13b of the flange portion 13c serves as a positioning stopper. A pair of arc-shaped escape portions 13d are cut out on the side wall of the embedded portion 13b.
A U-shaped slit-shaped inner opening 13g for filling the adhesive is formed on the side wall of the main body 13a. A right male screw 13e is formed on the outer surface of the inner vertebral column 13 and a left male screw 13f is formed on the outer surface of the inner vertebral column 13 '.

Also in this embodiment, the same effect as that of the first embodiment can be obtained. Further, in this embodiment, the outer vertebral canal 12
And the pair of inner vertebrae 13 and 13 'constitute the artificial vertebral body 11, and these parts were connected by the left and right screws. Therefore, when adjusting the height dimension, the outer vertebra 12 It only needs to be turned to the left or right, so that the size can be adjusted while it is set between healthy vertebral bodies, and it is easier to handle.

In the first and second embodiments, the screwing type is adopted as the structure for adjusting the height of the artificial vertebral body, but the adjusting structure of the present invention is not limited to the screwing type. For example, a structure in which it is slidably inserted, a structure in which positioning is performed at an adjustment position by adding irregularities, or the like can be adopted, and any structure may be used as long as the axial lengths of the outer and inner vertebral canals can be changed. . FIG. 14 shows a modification of the first embodiment described above.
The same reference numerals denote the same or corresponding parts. In this example, a hole 2g is formed on the inner surface of the main body 2a of the outer vertebral column 2 instead of a female screw, and the main body 3a of the inner vertebral column 3 is formed in the hole 2g.
1 is different from FIG. 1 in that it is slidably inserted.
A ring-shaped nut 4 is screwed onto the male screw 3e of the main body 3a. Although not shown in FIG. 14,
Similar to the first embodiment, openings for filling the adhesive are formed in the side walls of the main bodies 2a and 3a, respectively. In this case, when adjusting the height of the artificial vertebral body, it is only necessary to appropriately adjust the tightening amount of the nut 4, so that the height can be easily adjusted.

[0015]

As described above, according to the metal artificial vertebral body of the present invention, the structure in which the inner vertebral cylinder is variably inserted in the outer vertebral cylinder in the axial length thereof is adopted. The height of the vertebral body can be adjusted according to the normal interval between healthy vertebral bodies, all vertebral body treatments can be handled with a small number of artificial vertebral bodies, and there is an effect that the manufacturing and management thereof can be facilitated. Since it is provided, it is easy to set it between the healthy vertebral bodies and the operation time can be shortened, and the artificial vertebral bodies can be prevented from turning, slipping and falling off, and further, cracking during handling can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional front view showing an artificial vertebral body according to a first embodiment of the present invention.

FIG. 2 is a front view of the outer vertebral canal of the first embodiment.

FIG. 3 is a plan view of the outer vertebral canal of the first embodiment.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a front view of the medial vertebral canal of the first embodiment.

FIG. 6 is a bottom view of the medial vertebral canal of the first embodiment.

7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is a diagram showing a procedure of vertebral body treatment using the artificial vertebral body of the first embodiment.

FIG. 9 is an exploded perspective view of an artificial vertebral body according to a second embodiment of the present invention.

FIG. 10 is a side view of the artificial vertebral body of the second embodiment.

FIG. 11 is a sectional side view of the artificial vertebral body of the second embodiment.

FIG. 12 is a schematic diagram showing a connected state of vertebral bodies using a conventional artificial vertebral body.

FIG. 13 is a schematic diagram showing a connected state of vertebral bodies using a conventional artificial vertebral body.

FIG. 14 is a diagram showing a modification of the first embodiment (FIG. 1).

[Explanation of Codes] 1,11 Artificial vertebral body 2,12 Outer vertebral canal 2f, 12f Outer opening for adhesive filling 3,13,13 'Inner vertebral canal 3f, 13f Inner opening for adhesive filling

Claims (2)

(57) [Claims] 1. A metal artificial vertebral body for connecting adjacent healthy vertebral bodies, which is arranged in a portion where a vertebral body having a lesion is removed, and has a tubular outer vertebral canal and an outer vertebral canal in the outer vertebral canal. It is composed of a tubular inner vertebral canal whose length in the axial direction is variably inserted . The lateral wall of the outer vertebral canal and the inner vertebral canal communicate with the inside of the canal.
An opening for filling the adhesive is formed, and the end wall is connected to the inside of the cylinder.
An embedded part is formed that has a notch-shaped escape part in side view.
A metal artificial vertebral body characterized by being 2. The side wall of the outer vertebral canal according to claim 1.
The internal threads formed on the inner surface and the outer surface of the side wall of the inner vertebral canal
Axial length adjusting means consisting of formed male screw and
An artificial vertebral body made of metal.