JPH10179622A - Vertebral implant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce time required for vertebral arch plastic operation of a spine, by providing a fixing means to fix a plate to be placed so as to bridge a bone prosthesis mounted between an ablated part or a cut-up part of an ablated part of a vertebral arch part of the vertebra and the bone prosthesis on the plate. SOLUTION: When this vertebral implant is to be mounted on a cervical vertebra 1, a bone prosthesis 11 is mounted on an ablation part 6 from which a vertebral arch is ablated and a plate 12 is placed to bridge the ablated part 6 of the cervical vertebra 1 by inserting a screw 13 into a hole in the plate 12, and a lock nut 13a is screwed with a screw 13 of the bone prosthesis 11 protruded from the plate 12 to complete the mounting. In this case, pins 15, 15 protruded from the bone prosthesis 11 are engaged with the ablated part 6 of the cervical vertebra 1 to retain the prosthesis 11 on a prescribed position on the cervical vertebra 1, and an engaging part 16 equipped on the plate 12 is engaged with the cervical vertebra 1 to fix the prosthesis 11 on the prescribed position without slipping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spinal implant used for laminoplasty of a cervical vertebra, for example.

[0002]

2. Description of the Related Art The human vertebral column is composed of a sacrum and a sacral fusion of seven cervical vertebrae, twelve thoracic vertebrae, five lumbar vertebrae and five sacral vertebrae. As shown in FIG. 5, a normal cervical vertebra 1 has a portion 2 through which a vertebral canal passes and a vertebral hole 3 through which a nerve passes, and a spinous process 4a is formed in a vertebral arch 4 adjacent to the vertebral hole 3. The vertebral arch 4 has a structure that does not affect nerves passing through the vertebral foramen 3. By the way, when an abnormality occurs in the normal cervical vertebra 1, the cervical vertebra 1 has a vertebral arch 4 indicated by a dotted line extending in the direction of the vertebral hole 3 as shown in FIG. It will compress the nerves passing through 3 and affect motor function. The overhang portion 5 of the vertebral arch 4 is the vertebral foramen 3
Laminoplasty is known as a treatment for compressing the nerve passing through the ligament.

[0003] The above-mentioned laminoplasty procedure includes a method in which the vertebral arch 4 and the overhanging portion 5 of the cervical vertebra 1 are resected so that the overhanging portion does not compress a nerve passing through the vertebral foramen 3, and a spinous process. There is a method in which the overhanging portion 5 does not compress the nerve passing through the vertebral foramen 3 by excision of the vertebral arch 4 by cutting off the 4a.

In a laminectomy operation for resecting the vertebral arch 4 of the cervical vertebra 1, as shown in FIG. 7, the vertebral column 4 of the cervical vertebra 1 is resected, and the resected portion 6 is shown in FIG. 8. The bone prosthesis 7 is attached, the bone prosthesis 7 is sutured to the cervical vertebra 1 with a thread, and the bone prosthesis 7 is used as a part of the vertebral arch 4 of the cervical vertebra 1.

[0005] In the laminectomy operation for cutting the vertebral arch 4 of the cervical vertebra 1, as shown in FIG. 9, the spinous process 4 a is excised, and the spinous process 4 a is excised using a surgery storm (not shown). Cut 9a and cuts 9b, 9 at both ends
10 is provided as shown in FIG. 10, and the lamine portions 4b, 4b divided by the cut 9a are cut and raised along the cuts 9b, and between the cut and raised portions 4b, 4b, as shown in FIG. 7 is attached, and the bone replacement piece 7 is sutured to the cut and raised portions 4b, 4b of the vertebral arch 4 with a thread.
Is used as a part of the vertebral arch 4 of the cervical vertebra 1.

[0006]

The bone graft used for the cervical vertebral laminoplasty is shaped to fit between the resected portion of the cervical vertebra or the cut and raised portion of the vertebra. However, the bone prosthesis is expensive because it is a ceramic molded product. Moreover, since the fixation of the bone prosthesis to the cervical vertebrae is performed by thread suture means, this operation requires skill and considerable time. .

[0007] The present invention has been made in view of the above points, and has as its object to provide a spinal implant that can reduce the time required for vertebral laminoplasty.

[0008]

SUMMARY OF THE INVENTION A spinal implant of the present invention includes a resection portion formed by resection of a vertebral vertebrae, or a bone replacement piece mounted between cut and raised portions of the vertebral portion; It comprises a plate arranged to bridge the resected portion of the vertebrae and fixing means for fixing the bone replacement piece to the plate.

In the spinal implant of the present invention, a pin is provided on the surface of the bone prosthesis in contact with the vertebrae to ensure the fixation of the bone prosthesis to the vertebrae, or the locking portion is provided on the surface of the plate in contact with the vertebrae. The plate can be fixed at a predetermined position on the vertebrae of the vertebrae.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, FIG.
The same members as those in FIG. 6 are denoted by the same reference numerals.

FIG. 1 shows an example in which a spinal implant according to the present invention is applied to a cervical vertebra laminoplasty procedure.
A spinal implant 10 is attached to the resected portion 6 of the vertebral arch 4 of the cervical vertebra 1.

As shown in FIG. 2, the spinal implant 10 includes a bone replacement piece 11 attached to a resection portion 6 formed by resection of the cervical vertebra 1 and a resection portion 6 of the cervical vertebra 1. It comprises a plate 12 arranged so as to bridge, and a fixing means 13 for fixing the bone replacement piece 11 to the plate.

The bone replacement piece 11 is made of stainless steel (SUS
316) or a titanium alloy as a material, a fan-shaped main body 14 formed into a shape corresponding to the shape of the resected portion 6 of the cervical vertebra 1, and pins 15 protruding from both sides of the main body 14. , 15. A screw 13 is provided on the large-diameter surface of the main body 14 so as to protrude outward. A lock nut 13a is screwed onto the screw 13.

The plate 12 is made of stainless steel (SUS
316 series) or a titanium alloy thin plate is formed into an arc shape, and the locking portions 16 such as saw teeth are formed on both end surfaces.
Are formed. The locking portion 16 prevents the plate 12 from slipping and fixes the plate 12 at a predetermined position of the cervical vertebra 1. Screw 1 is located at the center of plate 12
A hole 17 through which 3 passes is formed.

Next, the operation will be described. To attach the spinal implant 10 to the cervical vertebra 1, a bone replacement piece 11 is attached to a resection 6 formed by resection of the vertebral arch of the cervical vertebra 1, and the plate 12 is inserted into a hole 17 formed in the plate 12. The cut portion 6 of the cervical vertebra 1 is arranged so as to bridge so that the screw 13 of the piece 11 passes therethrough, and the lock nut 13 a is screwed onto the screw 13 of the bone replacement piece 11 protruding from the plate 12. In this case, the pins 15, 15 projecting from the bone replacement piece 11 are locked to the resected portion 6 of the cervical vertebra 1, so that the bone replacement piece 11 is held at a predetermined position of the cervical vertebra 1 and Since the locking portion 16 provided on the plate 12 is locked to the cervical vertebra 1, the plate 12 is fixed at a predetermined position without slipping after being fixed.

FIGS. 3 and 4 show another embodiment of the present invention. The spinal implant 10 used in this embodiment has the same structure as the spinal implant shown in FIG. Reference numeral 11 denotes a shape fitted into a space formed between the cut and raised portions 4b of the vertebral arch 4 of the cervical vertebra 1.

To attach the spinal implant 10 to the cervical vertebra 1, the bone replacement piece 11 is mounted between the cut-and-raised portions 4 b and 4 b of the vertebral arch 4 of the cervical vertebra 1, and the plate 12 is provided with a hole 17 in the plate 12. The cut-and-raised portion 4 of the vertebral arch 4 of the cervical vertebra 1
This is performed by arranging b and 4b so as to bridge, and screwing a lock nut 13a to a screw 13 of the bone replacement piece 11 protruding from the plate 12.

In the above embodiment, the spinal implant is applied to the cervical vertebra, but the spinal implant can be applied to the thoracic vertebra and the lumbar vertebra.

In the above embodiment, the bone replacement piece 11
Although a screw and a lock nut are used as fixing means for fixing the bone filling piece to the plate 12, a fixing means such as a snub bin may be used as long as the bone replacement piece 11 can be fixed to the plate 12 without loosening.

[0020]

As described above, according to the present invention, the operation time of the laminoplasty of the vertebra can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a spinal implant according to the present invention attached to a cervical vertebra.

FIG. 2 is a perspective view showing a state before a spinal implant according to the present invention is attached to a cervical vertebra.

FIG. 3 is a view corresponding to FIG. 1 of another embodiment of the spinal implant according to the present invention;

FIG. 4 is a view corresponding to FIG. 2 of another embodiment of the spinal implant according to the present invention.

FIG. 5 shows a normal cervical vertebra.

FIG. 6 shows an abnormal cervical vertebra.

FIG. 7 is a diagram showing a state in which a vertebral arch portion has been resected from an abnormal cervical vertebra.

FIG. 8 shows a conventional cervical laminoplasty procedure.

FIG. 9 is a diagram showing a state in which a spinous process has been removed from an abnormal cervical vertebra.

FIG. 10 is a diagram showing a state in which cuts and cuts are made in the vertebral part of an abnormal cervical vertebra from which spinous processes have been resected.

FIG. 11 is a diagram showing a state in which a vertebral arch of an abnormal cervical vertebra from which spinous processes have been resected is cut and raised.

FIG. 12 is a diagram showing a conventional cervical laminoplasty procedure.

[Explanation of symbols]

 Reference Signs List 1 cervical vertebra 4 vertebra 4 vertebral arch part 4a spinous process 4b cut-and-raised part 6 resected part 10 spinal implant 11 bone filling piece 12 plate 13 fixing means 15 pin

Claims (5)

[Claims] 1. A bone replacement piece attached between a resection portion formed by resection of a vertebral vertebrae or a cut-and-raised portion of a vertebral portion, and a resection portion or resection portion of a vertebral vertebra. A spinal implant having a plate positioned to bridge the raised portion and a securing means for securing the bone augment to the plate. 2. The spinal implant according to claim 1, wherein a pin is provided on a surface of the bone replacement piece in contact with the vertebrae. 3. The spinal implant according to claim 1, wherein a locking portion is provided on a surface of the plate in contact with the vertebrae. 4. The spinal implant according to claim 1, wherein the fixing means is a screw means. 5. The spinal implant according to claim 1, wherein the fixing means is a snap pin means.