JPH11290337A - Guide wire piercing auxiliary tool for vertebra fixing operation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely direct the piercing of a guide wire by fixing a position fixing part where a guide wire piercing auxiliary tool is arranged on the pedicle of arch of the vertebra and fixing the position so as to permit a lead part for guiding a wire piercing direction to be abutted on the piercing point of the center part of a lower joint projection. SOLUTION: The position fixing part constituting the guide wire piercing auxiliary tool (auxiliary tool in the following) 1 fixes the auxiliary tool 1 to the proper position of a bone to be operated and the lead part 4 holds a guide wire to be pierced into the prescribed part of the bone to be operated. A connecting part 3 fixes the parts 2 and 4 at its both ends in order to hold the parts 4 and 2 in prescribed correlative position relation. An operator grips a grip part 7, fixes the lower end of the part 2 of the tool 1 at the prescribed part of the bone, abuts the tip of the part 4 (the tip of a guide tube 41 at the side of the bone) on the bone to be operated and pierces the wire into the bone at a prescribed angle. Then, a screw is externally fitted onto the guide wire, an intervertebral joint is penetrated, the screw is embedded and vertebra is surely fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guidewire insertion aid for screw implantation in spinal fusion.
More specifically, for inserting a guide wire used in an operation such as an atlantoaxial fixation by the Margel method performed for the treatment of atlantoaxial instability into an appropriate direction and position. For tools.

[0002]

BACKGROUND OF THE INVENTION Atlas axis instability is a disease caused mostly by rheumatoid arthritis, trauma, and the like. Cervical pain, range of motion of the neck due to subluxation and instability of the atlas axis joint. It can lead to restriction, paralysis of the extremities due to spinal cord compression, and even the possibility of sudden death. As a surgical method for this disease, a method of fixing the atlantoaxial vertebra is generally used, and a method of interlaminar bone grafting and fixation by Brooks, McGraw et al. Has conventionally been adopted. In these methods, the atlas and the axial vertebra are deployed from the posterior to expose the vertebral arch, and a bone is implanted and fixed between the vertebrae. Although these methods have relatively good results, they have a large burden on patients in that they require long-term external fixation after surgery due to insufficient fixation force. Even if the fixation is applied, there is a problem in various points such as postoperative correction loss, bone healing at an unnatural position with misalignment, unsuccessful fusion and false joints, etc. And it is by no means a satisfactory method.

[0003] The method proposed by Margel to overcome the disadvantages of such prior art methods, in addition to the interlaminar bone graft fixation described above,
A screw is penetrated and implanted in the atlanto-vertebral joint to further firmly fix the atlanto-axial vertebra. Sufficient fixation is achieved by this method, thereby avoiding the need for long term post fixation external fixation, and reducing the incidence of false joints and the potential for loss of correction.

[0004]

SUMMARY OF THE INVENTION However, Margel
The technique requires skill in the surgical procedure, and a particularly difficult point is the insertion of screws. That is, the screw is inserted in the correct direction without damaging both the vertebral artery existing on the outside of the atlanto-axial joint and the spinal cord running inward, and penetrates through the atlanto-axial joint to obtain a good fixation state. Then, it is necessary to embed the screw to an appropriate depth. In this method, the guide wire is inserted under X-ray fluoroscopy before the screw is inserted. However, the guide path of the guide wire is not visible, and the guide direction cannot be specified. It is difficult. Improper guidewire access can result in bleeding due to vertebral artery injury, damage to the spinal cord that can be fatal, and failure to secure with screws. When the bone tissue is weakened or softened, if the insertion of the wire is unsuccessful, the wire may not be inserted again to embed the screw. Therefore, although it is clear that good results can be obtained by the Margel method, at present the method has not been widely practiced.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an auxiliary tool which can surely orient the insertion of a guide wire for screw embedding in the Margel method.

[0006]

SUMMARY OF THE INVENTION The present invention has been accomplished as a result of intensive studies to achieve the above object, and is a guide wire insertion aid for screw implantation in spinal fusion. A stereotactic portion for installing the guidewire insertion assisting tool on the pedicle, and a guidewire guide direction which is disposed while maintaining a predetermined relative positional relationship with the stereotactic portion. And a lead portion for performing the operation.

The tip of the stereotaxic portion on the vertebra abutment side is placed on a pedicle of the vertebra, at a predetermined location adjacent to the center of the posterior edge of the facet joint,
Then, by holding the guide wire insertion tip of the lead part so that the guide wire is inserted from the center of the lower joint process, insert the guide wire to penetrate the lower joint process and the pedicle facet joint. A guide wire is inserted in an appropriate direction up to the upper vertebra.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

A guide wire insertion assisting tool 1 (hereinafter, referred to as an assisting tool 1) shown in FIG. 1 includes a localization section 2, a lead section 4, and a connecting section 3.

The stereotactic portion 2 is used to fix the assisting tool 1 at an appropriate position on the bone to be treated at the time of treatment.
Is for holding a guide wire 5 inserted into a predetermined part of the bone to be treated. The connecting portion 3 is for holding the lead portion 4 in a predetermined relative positional relationship with respect to the localization portion 2. Both ends 3 and 4 are fixed to both ends of the connecting portion 3.

On the upper surface of the connecting portion 3, a grip 7 for gripping by a practitioner is provided. The practitioner grasps the gripping portion to fix the lower end of the stereotactic portion 2 of the assisting tool 1 to a predetermined site of the bone to be treated, and at the same time, to the tip of the lead portion 4 (specifically, the tip of the guide tube 41 described later on the side of the bone to be treated) ) Abuts the treated bone,
Then, the guide wire 5 is inserted into the treatment bone at a predetermined angle. Thereafter, the screw 6 is externally fitted to the guide wire 5 and penetrated through the facet joint to embed the screw 6, so that the vertebra can be reliably fixed. In addition, as shown in FIG. 1, if the connecting portion 3 is provided so as to form an arc with the localization portion 2, the field of view is less likely to be obstructed or hindered during the treatment. A handle 71 is attached to the upper end of the grip 7 so that a practitioner can easily grip the assisting tool 1.

The stereotactic portion 2 shown in FIGS. 1 to 3 has a tapered vertebra abutment-side tip portion 23 and a stepped shape for preventing the tip portion 23 from being implanted into the bone to an excessive depth. A stopper 21 is provided.

The stopper 21 plays an important role in preventing the stereotactic portion 2 from being inserted deep into the bone, especially when the bone tissue is embrittled or softened. It is. By stopping the embedding of the stereotactic portion 2 with the stopper 21, the vertical position of insertion of the guide wire 5 from the lead portion 4 can be determined. The stopper 21 is useful even if it is formed by providing a flange as shown in FIG.

The screwing structure 22 shown in FIG.
By adjusting the vertical position of the tip of the stereotaxic part 2 by rotating the screw in, to adapt to various parts of the spine,
Then, it becomes possible to fix the assisting tool 1 corresponding to various bone shapes of the subject. That is, when the vertical position of the stereotactic portion 2 is adjusted, a lead portion 4 described later is adjusted to the outer shape of the bone.
Of the guide tube 41 and the lower end of the localization section 2 (stopper 21)
), Or the position of the insertion tip of the guide wire 5 can be changed according to the type of bone. However, the size and shape of the vertebra to be applied are relatively constant with little individual difference, and a specific site (eg, atlantoaxial vertebra) where the necessity of appropriate adjustment does not arise
In the case where the use of a screw is intended, the screwing structure 2 is particularly used.
Alternatively, the length of the localization portion 2 may be fixed as an integral structure without providing the localization portion 2.

The predetermined portion 12 on the pedicle 19 to which the stereotactic portion 2 is to be fixed is shown in FIG.
This is a central portion adjacent to the posterior edge 11 of the atlantoaxial joint 10 as shown in FIG.

Next, the lead portion 4 has a hollow guide tube 41 into which the guide wire 5 penetrates, which is attached so as to be displaceable back and forth in the guide tube outer tube 43 by a fixing screw 42 for position determination. is there. And this lead part 4
Are arranged so as to be inclined with respect to the longitudinal direction of the stereotactic portion 2 in order to insert the guide wire 5 at an appropriate angle (indicated by θ (insertion angle) in FIG. 1) with respect to the vertebrae. . These members 41 to 43 may be integrally formed, and the hollow cylindrical portion may not be displaced. However, if the guide tube 41 can be displaced, the guide tube 41 is displaced when the tip of the lead portion is held such that the insertion point 14 of the guide wire 5 from the lead portion 4 is at the center of the lower joint protrusion 13. Since the tip of the lever can be brought into contact with the center of the lower joint projection 13, the auxiliary tool 1 can be stably held.

Although not shown, the lead portion 4 is attached so as to be rotatable in the vertical direction (within the plane along the longitudinal direction of the localization portion 2) around the joint portion with the connecting portion 3,
The insertion angle θ may be arbitrarily changeable by making the angle of inclination relative to the longitudinal direction of the localization section 2 variable. In this way, it is possible to adjust the assisting device 1 to adapt to various parts of the spine and to adapt to various bone shapes of the subject. This is realized, for example, by introducing a known mechanism such as a gear structure or a screwing structure into a joint portion between the connecting portion 3 and the lead portion 4.

The predetermined relative positional relationship between the stereotactic portion 2 and the lead portion 4 provided by the connecting portion 3 is such that when the stereotactic portion 2 is set at the predetermined site 12 on the pedicle 19, The positional relationship is such that the guide wire 5 is inserted in an appropriate direction from the guide wire insertion tip (guide tube tip). That is, the guide wire 5 is connected to the lower joint protrusion 13.
From the central insertion point 14 through the inferior articular process 13 and the atlantoaxial joint 10 to the atlantic vertebra, substantially parallel to the angle of the inferior articular process 13 to the posterior edge 18 of the vertebral body and to the atlantoaxial vertebra. The lead portion 4 is disposed so as to be inclined with respect to the longitudinal direction of the stereotactic portion 2 so as to be able to penetrate substantially the center of the joint 10. Specifically, in the case of the assisting tool 1 applied at the atlantoaxial, the insertion path of the guide wire 5 is 5 to 10 mm, preferably about 7 mm from the stopper 21 at the distal end of the stereotactic portion 2.
The angle (indicated by θ (insertion angle) in FIG. 1, θ) formed between the guide wire 5 and a plane perpendicular to the longitudinal direction of the stereotactic portion 2 is oriented downward (shown in FIG. 1, h). 3
The angle may be 5 to 50 degrees, preferably 40 to 45 degrees.

Note that h and θ are determined before operation by X-ray or CT.
The preferred numerical value can be set by measuring the angle of the inferior joint process 13 with respect to the posterior edge 18 of the vertebral body and the cross-sectional size of the facet joint 10 and confirming the shape of the portion to be treated. That is, the insertion angle θ of the guide wire 5 is preferably substantially parallel to the angle (inclination angle, shown by α in FIG. 5A) of the inferior articular protrusion 13 with respect to the posterior edge 18 of the vertebral body. In order to pass almost the center of the facet joint, h is set to the front-rear diameter of the facet joint (FIG. 5 (b), Xa
Alternatively, the value may be set to a value approximate to 1/2 of Xb).

Next, with reference to FIGS. 2 and 4, a method for embedding the screw 6 by using the auxiliary tool 1 for fixation of the atlantoaxial vertebra will be described.

First, as shown in FIG. 2A, the distal end 23 of the stereotactic portion 2 of the assisting device 1 is fixed to a predetermined portion 12 on the pedicle near the center of the posterior edge 11 of the atlanto-vertebral joint 10. I do. At this time, the distal end portion 23 is embedded in the bone until the stopper 21 reaches the surface of the pedicle 19. Then, the distal end of the hollow guide tube 41 of the lead portion 4 is brought into contact with the center of the lower joint protrusion 13, and the guide wire 5 is held so as to be inserted from the center of the lower joint protrusion 13. The guide wire 5 is inserted from the guide tube 41 while maintaining the state in which the stereotactic portion 2 and the lead portion 4 are fixed as described above and the stereotactic portion 2 stands upright with respect to the posterior edge 18 of the vertebral body. By using the assisting tool 1 in this manner, the guide tube 41 penetrates through approximately the center of the subaxial joint process 13 and the atlantoaxial joint 10 to the atlantic vertebra (FIG. 2).
As shown in (b)), the direction for inserting the guide wire and the insertion position can be determined. Guide wire 5
Is conventionally used in this technology, and has a sharp tip, and can be started from the guide tube 41 or inserted using an electric motor or the like. Next, the screw 6 is buried in the bone along the inserted guide wire 5 by a standard method (see FIG. 4). That is, a screw 6 having a hollow structure in which a groove to be screwed into a bone is carved around the guide wire 5 is externally fitted to the guide wire 5.
The screw 6 is buried in the bone along the insertion path. Therefore,
The screw 6 can be reliably embedded through the facet joint.

The material constituting the auxiliary tool 1 is preferably stainless steel, titanium, or the like, since it can be subjected to dry heat, high-pressure sterilization, etc., and has an appropriate specific gravity and sufficient rust prevention, rigidity and strength. As the guide wire 5 and the screw 6, those conventionally used, such as those made of stainless steel or titanium, can be used as they are. The screw 6 is particularly suitable for compatibility with a living body,
Those made of titanium are preferred.

After the guide wire 5 is inserted using the auxiliary tool 1 of the present invention, the inserted guide wire 5 is pulled out instead of the screw 6 being buried, and is drawn along the formed insertion path. A vertebral osteosynthesis or fixation can also be achieved by implanting pins. As this pin, a pin conventionally used in the technical field may be applied, and titanium or the like may be made of the same material as the screw 6. Use in such procedures is also contemplated in the present invention.

[0024]

EXAMPLES [Experimental example] In order to select an appropriate size and outer shape as a guide wire insertion aid used for fixation of the atlanto-axial vertebra, the axial vertebra in a sagittal vertebra cross-section of 52 adults was selected. Inclination angle of lower joint process to posterior edge of vertebral body (Fig. 5
(A) and α) are measured by X-ray side images, and the size of the atlanto-axial joint, that is, the front and rear diameters (Xa and Xb) on both the left and right sides of the joint (FIG. 5B) and the lateral diameter (FIG. 5
(B), Ya and Yb) were measured on CT, and these statistical processes were performed. Table 1 shows the results.

[0025]

[Table 1]

From these results, when the guidewire insertion aid is used for fixation of the atlantoaxial vertebra, the insertion angle θ of the guidewire from the guide portion is 35 to 50 degrees, preferably 40 to 50 degrees.
45 degrees, and the stopper 21 at the tip of the stereotactic portion 2
It has been found that the shape should be such that the guide wire can be inserted 5 to 10 mm below.

[Example] The guidewire insertion aid of the present invention was used for the Margel method for five cases of atlantoaxial instability. The guidewire insertion aid was adjusted so that the guidewire reached 44.7 degrees at an insertion angle of 7 mm below the stopper at the tip of the stereotactic portion.

At the time of the operation, for each of the left and right atlantoaxial vertebrae,
As described above, the stereotactic portion of the guidewire insertion assisting tool is installed at a predetermined position in the center of the posterior edge of the atlantoaxial vertebra, so that the guidewire insertion point from the lead portion is located at the center of the lower joint process,
A guide wire was inserted through the guide tube of the lead. Next, a screw was embedded along the inserted guide wire. The bone grafting was performed according to a conventional method.

The age, sex, disease name, inclination angle of the sub-axial joint process, and the anterior-posterior diameter of the left and right atlanto-axial joints of the five subjects are shown in Table 2 below.

[0030]

[Table 2]

In all cases, the procedure was successfully completed in a short time without damaging the vertebral artery or spinal cord, and without causing extra bleeding, etc. As a result, the screw was moved from the center of the inferior joint process to the axial spine. It was securely implanted through the pedicle and atlantoaxial joint (see FIG. 4). No postoperative complications associated with the use of the guidewire insertion aid of the present invention were observed at all in any of the subjects, and the Margel
Good results were achieved with the method, and there was no need for long-term external fixation after surgery.

[0032]

As described above, the guidewire insertion aid for screw implantation in spinal fusion according to the present invention allows a guidewire to be inserted through a vertebral joint and into an appropriate direction of a vertebra, Spinal fixation by embedding screws can be performed easily and quickly without depending on the skill level or intuition of the practitioner. At this time, occurrence of bleeding and spinal cord injury can be significantly suppressed, and in some cases, it is possible to avoid the necessity of performing the operation under fluoroscopy.

Further, the length of the stereotactic portion of the guide wire insertion assisting device can be adjusted, and the angle of insertion from the lead portion can be changed, so that the device can be adjusted to adapt to various parts of the spine. And various bone shapes of the subject.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view of a guidewire insertion aid 1 according to an embodiment of the present invention.

FIGS. 2A and 2B are a perspective view showing a use state of the guide wire insertion assisting tool 1 shown in FIG. 1 in an annulus vertebra and a perspective view showing an embedded state of a screw 5 after guide wire insertion. .

FIGS. 3A and 3B are a partial cross-sectional view of a screwing structure 22 of a localization unit 2 having an adjustable length and a side view showing a flange-shaped stopper 21 provided at a distal end of the localization unit 2; is there.

FIG. 4 is a schematic view showing a state in which a guide wire is inserted into a human atlantoaxial vertebra using the guide wire insertion aid 1 of the present invention, and a screw 6 is embedded.

FIGS. 5A and 5B are a cross-sectional view showing the inclination angle α of the subaxial axle of the human atlas vertebra with respect to the posterior edge of the vertebral body, and a transverse cross-sectional view of the atlas articular surface of the atlas.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Guide wire insertion assistance tool 2 ... Orientation part 3 ... Connection part 4 ... Lead part 5 ... Guide wire 6 ... Screw 7 ... Grip part 10 ... Intervertebral joint 11 ... Atlanto-vertebra joint posterior edge 12 ... Predetermined part 13 ... Inferior joint process 14 ... insertion point 18 ... vertebral body posterior edge 19 ... pedicle 21 ... stopper 22 ... screw structure 23 ... vertebra abutment side tip 41 ... guide tube 42 ... fixing screw for position determination 43 ... guide tube Outer cylinder 71 ... handle

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[Procedure amendment]

[Submission date] April 8, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006] The present invention, which was accomplished intensive result of extensive studies to achieve the above object, the rear
A guidewire insertion aid for screw implantation in spinal fusion by deployment, a stereotactic portion for installing the guidewire insertion assisting tool on a pedicle, and a predetermined relative positional relationship with the stereotactic portion A lead portion for guiding the guide wire insertion direction , wherein the stereotactic portion is fixed at a predetermined position on the pedicle,
Position the end so that it abuts the insertion point in the center of the lower joint process
In this way, the guide wire is moved from the insertion point to the posterior edge of the vertebral body.
Approaching almost parallel to the angle of the inferior joint process,
Phase so that it is properly oriented to penetrate the center
The localization part and the lead part are arranged in a positional relationship .

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

The stereotactic portion 2 is used to fix the assisting tool 1 at an appropriate position on the bone to be treated at the time of treatment.
Is for holding a guide wire 5 inserted into a predetermined part of the bone to be treated. The connecting portion 3 is for holding the lead portion 4 in a predetermined relative positional relationship with the localization portion 2, and both 2 and 4 are fixed to both ends of the connecting portion 3.

Claims (5)

[Claims] 1. A guide wire insertion aid for screw implantation in spinal fusion surgery, comprising: a stereotactic portion for installing the guide wire insertion assist device on a pedicle; A guide wire insertion aid, comprising: a lead portion for guiding a guide wire insertion direction, which is provided while maintaining a relative positional relationship. 2. The guide wire insertion assisting tool according to claim 1, wherein the tip of the stereotactic portion is movable up and down. 3. The guidewire insertion aid according to claim 1, wherein a guidewire insertion tip of the lead portion is displaceable in a longitudinal direction. 4. The guidewire insertion aid according to claim 1, wherein an angle formed between the lead portion and a vertical surface with respect to a longitudinal direction of the stereotactic portion can be changed. 5. The guidewire insertion aid according to claim 1, wherein a stopper is provided at a tip of the stereotaxic portion on the vertebra abutment side.