WO2023033051A1

WO2023033051A1 - Puncture probe

Info

Publication number: WO2023033051A1
Application number: PCT/JP2022/032785
Authority: WO
Inventors: 航太渡邉; 守雄松本; 敏也鎌田; 幸一川島; 英明黒金
Original assignee: 慶應義塾; 株式会社鎌田スプリング; さいたま商工会議所
Priority date: 2021-08-31
Filing date: 2022-08-31
Publication date: 2023-03-09
Also published as: JP2023035206A; JP7211582B1

Abstract

In order to provide a probe that does not break off within a vertebra and allows easy monitoring of the situation within the vertebra, a probe (1) includes a cylindrical shaft portion (10) that penetrates the inside of a bone and a grip portion (20) that can be grabbed by an operator, wherein the shaft portion (10) is formed of material (SUS304) for springs and includes a narrow portion (11) consisting of grooves (12) provided at regular intervals on an outer circumference of a tip portion of the shaft portion (10). A surface of the shaft portion (10) is provided with markings (14) every 10 mm from a tip, and a painted portion (15) is provided in a section 20-30 mm from the tip. When the probe (1) is inserted into a vertebra (30) and further inserted in a state in which a tip of the probe (1) is in contact with an inner wall of a cortical bone (31) at a pedicle (33), the shaft portion (10) becomes deformed due to plastic deformation, and when the probe (1) is pulled out, the shaft portion (10) remains deformed, allowing the internal condition and shape of the vertebra (30) to be recognized.

Description

puncture probe

The present invention relates to a puncture probe that can be used for scoliosis surgery, etc., in which a corrective device is installed in the spine.

Conventionally, in scoliosis surgery or the like in which a corrective device is installed in the spine, a procedure is performed in which a pedicle screw is screwed into the vertebrae to fix it, and the corrective device is connected to the pedicle screw to correct the spine. there is

When screwing the pedicle screw into the vertebrae, a prepared hole and tap are formed in the vertebrae in advance, and then the pedicle screw is screwed in. By providing a pilot hole in the vertebra in this way, the pedicle screw can be screwed in at a precise position and angle.

Conventionally, when drilling this pilot hole, a probe with a spherical tip and a flexible shaft (see Non-Patent Document 1) is used. The probe described in Non-Patent Document 1 has a ball portion with a spherical tip, a tapered shaft portion that gradually tapers toward the tip, and a grip portion provided behind the shaft portion. have. The shaft portion is flexible.

The pedicles and vertebral bodies (or vertebrae) are cortical bone with a hard surface and relatively soft cancellous bone inside. For this reason, when drilling the pilot hole, as described in Non-Patent Document 1, an opening is provided in the cortical bone using a bone drill, and the distal end of the probe is inserted through this opening. Insert the tip into the cancellous bone while gently tapping the end with a hammer. Such a procedure can drill a pilot hole in the vertebrae.

Since the probe has a flexible shaft portion, when the ball portion at the tip contacts the inner wall of the cortical bone when the probe is inserted into the cancellous bone, the ball portion is guided by the inner wall of the cortical bone. The shaft part is deformed. In this probe, when the shaft portion is deformed, the deformed state is maintained. Therefore, when the probe is pulled out from the vertebrae, the structure inside the vertebrae can be grasped to some extent from the degree of bending of the shaft portion.

JP 2015-19782 A

By the procedure disclosed in Non-Patent Document 1, it is possible to make a pilot hole in the vertebrae and grasp the internal structure of the vertebrae. Since the shaft portion near the portion is thin, there is a risk that the shaft portion will break if an excessive load is applied.

In addition, as this type of probe, there is one described in Patent Document 1, but the probe itself is made of a hard material and does not deform even when it is punctured into the vertebrae. Therefore, the probe described in Patent Literature 1 cannot grasp the structure within the vertebrae.

In addition, although the probe described in Patent Document 1 has a scale on the side, when the probe is punctured into the vertebrae, it is not possible to know where the tip of the probe is positioned between the cortical bone and the cancellous bone. Therefore, how far to insert the probe depends largely on the intuition of the operator.

An object of the present invention is to improve a puncture probe that can be used for scoliosis surgery or the like in which an orthodontic device is installed in the spine. It is an object of the present invention to provide a probe that makes it easy to grasp the position of the tip of a probe.

In order to achieve the above object, the probe of the present invention is a probe capable of penetrating the inside of a bone having cancellous bone inside the cortical bone, comprising a cylindrical shaft portion and a shaft portion which are connected to each other for surgical operation. a grip portion that can be gripped by a person, and the shaft portion is formed of a spring material, holds the grip portion, and applies a force to the tip of the shaft portion in a direction perpendicular to the axial direction of the shaft portion. When bent, the amount of return after bending by a length of 1/4 of the length of the shaft portion is 75% or more and 85% or less.

In the probe of the present invention, the shaft portion is cylindrical and made of a spring material, so unlike the probe of Non-Patent Document 1, it does not have a tapered portion, so breakage can be prevented. . In addition, when the shaft portion is bent by applying force to the tip in a direction perpendicular to the axial direction, the return amount after being bent by 1/4 of the length of the shaft portion is 75%. It has a physical property of 85% or less. In this way, the shaft part has appropriate flexibility and undergoes plastic deformation under certain conditions.

With this configuration, when the shaft portion is inserted into the bone and comes into contact with the wall surface of the pedicle, etc., and a predetermined external force is applied, plastic deformation occurs and the bone bends. It can be taken out, and the internal shape of the bone such as the pedicle can be confirmed with respect to the insertion angle of the shaft portion.

Further, in the probe of the present invention, it is preferable that the material of the shaft portion is SUS304 and the tensile strength is in the range of 1130 N/mm ² or more and 1470 N/mm ² or less. If the tensile strength is less than 1130 N/mm ² , the shaft portion will be too soft during use of the probe, making it difficult to insert the probe into cancellous bone. If the tensile strength exceeds 1470 N/mm ² , the amount of plastic deformation decreases, making it difficult to grasp the internal structure of the bone.

Further, in the probe of the present invention, a constricted portion formed by one or a plurality of grooves recessed over the entire circumference may be provided on the outer peripheral surface of the shaft portion near the tip portion. When the shaft portion is inserted into the bone and finally contacts or catches the anterior cortex, the operator can feel the constricted portion with his or her hand holding the grip portion.

Further, in the probe of the present invention, the surface of at least one of the shaft portion and the grip portion may be blasted. If the surface of the shaft is blasted, feedback can be obtained during insertion of the shaft into the vertebrae. When the surface of the grip portion is blasted, the grip portion is prevented from slipping.

Further, in the probe of the present invention, the shaft portion has a plurality of markings provided at equal intervals from the tip toward the grip portion on the outer peripheral surface, and a filled portion in which the space between adjacent specific markings is filled is provided. may be

According to this configuration, the marking is not just a scale, but a solid part that serves as a conspicuous mark, so the amount of insertion of the shaft part can be easily grasped during the procedure. In addition, by preparing different locations for this painted-out portion according to the procedure, it is possible to select a position that is easy to see during the procedure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a probe that is an example of an embodiment of the present invention, (A) is an overall side view, (B) is an enlarged view of a tip portion, and (C) is a cross-sectional view taken along line CC in (A). FIG. 5 is an explanatory diagram showing a state in which the degree of plastic deformation of the probe of the present embodiment is being checked; FIG. 4 is an explanatory diagram showing an example of use of the probe of the present embodiment, where (A) is an explanatory diagram showing a state in which the shaft portion of the probe is inserted into the bone, and (B) is an explanatory diagram showing a state in which the shaft portion is inserted into the bone; (C) is an explanatory view showing the state in which the probe is pulled out from the bone and the pedicle screw is screwed into the prepared hole made by the probe.

Next, a probe 1 that is an embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. As shown in FIGS. 1(A) and 3, the probe 1 of the present embodiment is capable of penetrating the inside of a vertebra 30, which is a bone having cancellous bone 32 inside cortical bone 31, and can penetrate the inside of the bone. and a grip portion 20 which is connected to the shaft portion 10 and which can be gripped by the operator.

As shown in FIGS. 1(A) to 1(C), the shaft portion 10 has a columnar shape, and the length from the tip to the boundary portion with the grip portion 20 is set to 60 mm. Further, the shaft portion 10 is provided with a constricted portion 11 in which grooves 12 are provided at regular intervals on the outer peripheral surface near the tip portion. Note that the length of the shaft portion 10 can be arbitrarily changed according to the procedure.

Further, as shown in FIG. 2, the shaft portion 10 was subjected to a bending test in which the grip portion 20 was held and a force was applied to the tip of the shaft portion 10 in a direction perpendicular to its axial direction (in an arc) to bend it. In fact, it is formed so that the amount of return when bent by a length of 15 mm, which is 1/4 of the length of the shaft portion 10 of 60 mm, is 75% or more and 85% or less. In this embodiment, as an example, the return amount is set to 79.1%.

In this embodiment, the material of the shaft portion 10 is stainless steel SUS304, which is a spring material. The tensile strength of stainless steel in this embodiment is 1190 N/mm ² .

The inventors of the present application conducted daily research on a probe that does not break in the technique of fixing a pedicle screw to a vertebra and allows easy grasping of the shape inside the vertebra. It has been found that SUS304, which is a material for steel, is suitable. It was also confirmed that among SUS304, a tensile strength in the range of 1130 N/mm ² or more and 1470 N/mm ² or less is suitable for this procedure.

Furthermore, regarding the extent of plastic deformation of the shaft portion 10, a member having a return amount of 75% to 85% or less in the above bending test was suitable for this procedure. In actual procedures, the amount of deflection is often less than 1/4 of the length of the shaft portion 10. I took a method to make it work.

Further, in the probe 1 of the present embodiment, the tip of the shaft portion 10 has a substantially hemispherical shape as shown in FIG. . The tip may be spherically shaped.

The constricted portion 11 is formed by providing two (plurality) recessed grooves 12 along the entire circumference of the outer peripheral surface of the cylindrical shaft portion 10 from the distal end toward the proximal end. A protrusion 13 is formed by the groove 12 in the constricted portion 11 . The projections 13 are formed at a total of two locations, one at the tip of the shaft portion 10 and one between the two grooves 12 . In this embodiment, the groove 12 and the protrusion 13 are formed so that the length in the axial direction is the same length A. As shown in FIG.

In this embodiment, the outer diameter B of the shaft portion 10 is 1.6 mm, and the outer diameter C of the groove 12 is 1.3 mm. The outer diameter C of the groove 12 is formed to be 75 to 85% of the outer diameter of the shaft portion 10, and is about 81% in this embodiment.

Although the number of grooves 12 is two in this embodiment, it may be one, or three or more. The shape of the groove 12 may be such that the bottom is flat when viewed from the side, as in the present embodiment, or it may be arc-shaped or V-shaped. At that time, it is necessary to secure strength so that the groove 12 does not cause breakage of the shaft portion 10 .

In addition, as shown in FIG. 1(A), the shaft portion 10 is provided with markings 14 every 10 mm (even intervals) from the tip toward the grip portion 20 . This marking 14 has a black painted portion 15 between adjacent specific markings 14 20 mm to 30 mm from the tip. Each marking 14 except for the painted portion 15 has a scale indicating the length from the tip with numbers (1 to 5). This marking 14 is performed by a technique called electrolytic marking (etching).

The outer surface of the shaft portion 10 is blasted except for the constricted portion 11 from the tip, and non-slip unevenness (not shown) is formed on the surface. This provides feedback when inserting the shaft portion 10 into the vertebrae.

As shown in FIG. 1(A), the grip part 20 has a hexagonal column shape and is provided with a tapered part 21 so as to taper at the tip. The outer surface of the grip part 20 is subjected to blasting, and non-slip unevenness (not shown) is formed on the surface. This prevents the grip portion 20 from slipping during the procedure, and makes it easier for the operator to apply force to the shaft portion 10 . In this embodiment, SUS303 is used as the material of the grip portion 20 .

In this embodiment, the shaft portion 10 and the grip portion 20 form an insertion hole 23 (see FIG. 1C) into which the proximal end portion of the shaft portion 10 is inserted at the distal end portion of the grip portion 20. The proximal end portion of the shaft portion 10 is inserted into the hole 23, and the periphery thereof is press-worked with an arc-shaped mold (not shown) to form the caulked portion 22 for joining.

As shown in FIG. 1(C), the crimped portion 22 is crimped by press working at six locations, and recessed portions are formed at six locations by machining with a mold (not shown). In this manner, the grip portion 20 and the shaft portion 10 are firmly coupled by performing press working at a plurality of locations with an arc-shaped press. The grip portion 20 and the shaft portion 10 may be joined together by welding or press-fitting, such as so-called shrink-fitting, cooling-fitting, bonding with an adhesive, screw tightening, brazing, or soldering. you can go

Next, a usage example of the probe 1 of this embodiment will be described with reference to FIG. The probe 1 of this embodiment can be used to verify the insertion angle and the insertion depth when the pedicle screw 40 is installed in the vertebra 30 .

The vertebrae 30 have a hard cortical bone 31 and a relatively soft cancellous bone 32, and the narrowed portion of the vertebrae 30 is a pedicle 33. Also, in FIG. 3(A), the portion where the distal end of the shaft portion 10 of the probe 1 is inserted is referred to as an insertion portion 34, and the portion of the cortical bone 31 below the vertebrae 30 is referred to as an anterior cortex 35 in the figure.

First, as shown in FIG. 3(A), the distal end of the shaft portion 10 of the probe 1 is inserted into the vertebrae 30 from the insertion portion 34 . At that time, an incision is made in the patient's back in advance, and an opening is provided in the cortical bone 31 of the vertebrae 30 at the insertion position of the probe 1 . Since the cortical bone 31 of the vertebrae 30 is hard and the cancellous bone 32 therein is relatively soft, the grip portion 20 does not move when the constricted portion 11 of the shaft portion 10 passes through the boundary portion between the cortical bone 31 and the cancellous bone 32 . You can check the feeling with the operator's hand holding it.

Even if the tip of the shaft portion 10 abuts against the inner wall of the cortical bone 31 of the pedicle 33 , the further advancement of the shaft portion 10 causes the shaft portion 10 to bend and pass through the pedicle 33 . and advance inside the cancellous bone 32 .

Next, as shown in FIG. 3B, when the shaft portion 10 is further advanced into the vertebrae 30, the shaft portion 10 advances while bending, and the distal end portion of the shaft portion 10 is positioned inside the anterior cortex 35. abut. At this time, the operator can confirm that the distal end portion of the shaft portion 10 has come into contact with the inner side of the anterior cortex 35 by feeling transmitted to the grip portion 20 .

On the other hand, depending on the patient, the anterior cortex 35 may be weak, in which case the tip of the shaft portion 10 may penetrate the anterior cortex 35 . In this case, since the feeling when the constricted portion 11 passes through the hole formed in the anterior cortex 35 is transmitted to the operator through the grip portion 20, the operator feels that the tip portion of the shaft portion 10 has penetrated the anterior cortex 35. can be confirmed.

The operator confirms the amount of insertion of the shaft part 10 into the vertebrae 30 at the time of confirming that the shaft part 10 abuts on the inner side of the anterior cortex 35 or penetrates the anterior cortex 35 . At this time, since the shaft portion 10 is provided with the marking 14, the painted portion 15, and the scale, the operator can easily confirm the amount of insertion of the shaft portion 10 into the vertebrae 30. FIG.

In particular, the painted portion 15 allows the operator to sense the position of the surface of the insertion portion 34 of the vertebra 30 . According to the feeling of the operator, the amount of insertion can be confirmed more quickly than, for example, when fine graduations are provided. In addition, when the skill level of the operator is high, the insertion amount can be accurately grasped without fine scales.

From this state, the probe 1 is pulled out from the vertebrae 30 as shown in FIG. 3(C). In the probe 1 of this embodiment, the shaft portion 10 is plastically deformed, so the deformed shaft portion 10 maintains its deformed state. The operator can select the length of the pedicle screw 40 by grasping the degree of bending of the shaft portion 10 .

Also, the appropriate length of the pedicle screw 40 should be selected according to the positions of the surfaces of the marking 14 and the painted portion 15 and the insertion portion 34 when the tip of the shaft portion 10 abuts or penetrates the anterior cortex 35 . can be done.

After that, the operator inserts the selected pedicle screw 40 into the vertebra 30 as shown in FIG. 3(C). Since the insertion amount of the pedicle screw 40 can be grasped by inserting the probe 1 , the operator can accurately insert the pedicle screw 40 into the vertebra 30 .

In each of the above-described embodiments, the material of the shaft portion 10 is SUS304, and the material of the grip portion 20 is SUS303. For example, materials other than stainless steel, steel, titanium, or titanium alloys that can be used in surgery can be used. At that time, the diameter of the shaft portion 10 can be appropriately changed and adjusted depending on each material.

In addition, although the length of the shaft portion 10 is set to 60 mm in the above embodiment, it can be changed as appropriate according to the procedure. As for the diameter of the shaft portion 10, the outer diameter B of the shaft portion 10 is set to 1.6 mm, but this diameter can also be appropriately changed according to the procedure.

In addition, the marking 14 may be made of paint or the like that reacts to radiation so that it can be visually recognized not only by the naked eye but also by a radiation measuring device (for example, a C-arm type fluorescence inspection device). Further, the position of the specific marking 14 that becomes the painted-out portion 15 is not limited to the above embodiment, and can be any position.

Reference Signs List 1 Probe 10 Shaft portion 11 Constricted portion 12 Groove 13 Projection 14 Marking 15 Painted portion 20 Grip portion 21 Tapered portion 22 Crimped portion 23 Insertion hole 30 Vertebral bone 31 Cortical bone 32 Cancellous bone 33... pedicle 34... insertion part 35... anterior cortex 40... pedicle screw

Claims

A probe capable of penetrating into bone having cancellous bone within cortical bone, comprising:
a cylindrical shaft;
A grip part that is connected to the shaft part and can be gripped by an operator,
The shaft portion is made of a material for a spring, and when the grip portion is held and the tip of the shaft portion is bent by applying a force in a direction perpendicular to the axial direction of the shaft portion,
A probe having a return amount of 75% or more and 85% or less after being bent by a length of 1/4 of the length of the shaft portion.
A probe according to claim 1,
The probe, wherein the material of the shaft portion is SUS304, and the tensile strength is in the range of 1130 N/mm 2 or more and 1470 N/mm 2 or less.
The probe according to claim 1 or 2,
A probe, wherein a constricted portion formed by one or a plurality of grooves recessed over the entire circumference is provided on the outer peripheral surface of the shaft portion near the tip portion.
A probe according to claim 1,
A probe, wherein a surface of at least one of the shaft portion and the grip portion is blasted.
A probe according to claim 1,
A probe characterized in that the shaft portion has a plurality of markings provided at equal intervals from the tip toward the grip portion on the outer peripheral surface, and a filled portion in which the spaces between adjacent specific markings are filled. .