JPH0324170Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates only to surgical applications used for preparing a graft base in posterior approach lumbar interbody fusion.

Conventional techniques and their problems Posterior interbody fusion, known as a treatment for lumbar disc herniation and spondylolisthesis, involves the operation of scraping the upper and lower bony endplates of the affected disc flat and parallel. ing. This operation is extremely difficult and requires skill because it takes a narrow entry path between the nerve root and the articular process. There is also a risk of nerve damage due to nerve root traction.

The purpose of this invention is to provide a surgical device that allows the above-mentioned operations to be performed easily and safely.

Means for solving the problem The surgical chisel according to this invention has a rectangular cross-sectional shape at the cutting edge, and two
A shallow groove is formed by leaving the cutting edge on the side.

Embodiment FIGS. 1 to 3 show a first embodiment of this invention.

The surgical chisel 1 of the first embodiment is a straight type chisel having a straight line as a whole. The handle 10 and neck 11 of this chisel 1 have a circular cross-sectional shape, the cutting edge portion 12 has a rectangular cross-sectional shape, and the neck 11 is slightly thinner than the other parts. A shallow circular groove 14 is formed on the distal end surface of the cutting edge portion 12, leaving the cutting edges 13 on two opposing upper and lower sides. Also, both side surfaces 1 perpendicular to the cutting edge 13 of the cutting edge portion 12
A groove 15 is formed in 2a that reaches the groove 14 on the distal end surface.

4 to 6 show a second embodiment of this invention.

The surgical chisel 2 of the second embodiment is of a curved type, and only the cutting edge portion 12 is curved in a plane parallel to the cutting edge 13. The rest is the same as in the first embodiment, and the same parts are given the same reference numerals.

FIG. 7 shows a third embodiment of this invention.

The surgical chisel 3 of the third embodiment is also of a curved type, and the cutting edge portion 12 is more curved than that of the second embodiment. The rest is the same as that of the second embodiment, and the same parts are given the same reference numerals.

The above three types of chisels 1, 2, and 3 can be used alone, but the three types of chisels 1, 2, and 3 in which the mutual spacing of the pair of cutting edges 13 is equal to each other are used as a set. It is preferable to do so. In this way, the bony endplates in front of the spinal column can be resected flatly and parallelly from the rear of the spinal column without damaging the cauda equina nerve and nerve roots that pass through the spinal canal. can do.

That is, first, the linear chisel 1 of the first embodiment
The right and left sides of the bony endplate 18 are excised from between the nerve root 16 and the articular process 17 using a (see FIG. 8).
Next, using the curved chisel 2 of the second embodiment, the anterior part of the bony endplate 18 is excised (see FIG. 9). Finally, the curved chisel 3 of the third embodiment is used to cut out the posterior part of the bony endplate 18 (see FIG. 10). In addition, in FIGS. 8 to 10, 19 indicates a nerve root retractor, and the parts A, surrounded by chain lines,
B and C show the bony endplate resection area.

Through the series of operations described above, it was possible to resect almost the entire bony endplate 18 in front of the nerve root 16 in a flat and parallel manner while minimizing traction on the nerve root 16.
This operation is extremely simple and does not require any skill.
Further, the shavings are removed from both sides 12 of the cutting edge portion 12.
It is removed through groove 15 of a.

Note that by preparing only a plurality of pairs of cutting blades 13 with different mutual spacings, it is possible to easily deal with changes in the height of the intervertebral space to be operated.

Effects of the invention Since the surgical chisel according to this invention has the above-mentioned configuration, posterior approach interbody fusion surgery can be performed extremely easily.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the first embodiment of this invention for surgical use only, Fig. 2 is an enlarged side view of the cutting edge portion of Fig. 1, and Fig. 3 is a sectional view taken along the line shown in Fig. 2. , FIG. 4 is a perspective view of the second embodiment of this invention for surgical use only, FIG. 5 is an enlarged side view of the cutting edge of FIG. 4, and FIG. 6 is a cross-section taken along the line shown in FIG. Fig. 7 is a drawing corresponding to Fig. 6 showing a third embodiment of this invention, and Figs. 8, 9, and 10 are plan views showing in order the states of each of the above embodiments used only for surgery. , FIG. 11 is a sectional view taken along the line XI-XI in FIG. 1, 2, 3... only for surgical use, 12... cutting edge portion, 13... cutting edge, 14... groove, 15... groove.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) Only for surgical use, where the cross-sectional shape of the cutting edge portion is rectangular, and a shallow groove is formed on the distal end surface of the cutting edge portion, leaving cutting edges on two opposing sides. (2) The surgical tool as set forth in claim 1 of the utility model registration claim, wherein a groove reaching the groove on the tip surface is formed on the side surface perpendicular to the cutting edge of the cutting edge portion. (3) Only for surgical use as set forth in claim 1 or 2 of the utility model registration claim, in which the cutting edge portion is linear. (4) Only for surgical use according to claim 1 or 2 of the utility model registration claim, in which the cutting edge portion is curved in a plane parallel to the cutting edge.