Cutting system

Abstract

To provide a cutting system capable of highly accurately and quickly processing a block body into a triangular or wedge shape without performing a scribing operation on a block body.SOLUTION: A cutting system comprises a gripping device 1 for gripping a block body 4, a cradle 24 including a processing blade 2, and a guide mechanism 3 for movably holding the gripping device 1 with respect to the cradle 24. The gripping device 1 includes a bottom part 9 having a bottom surface 9a in contact with a first surface 5 of the block body 4, a first reference member 10 having a first reference surface 10a in contact with a second surface 6 of the block body 4, a second reference member 11 having a second reference surface 11a in contact with a third surface 7 of the block body 4 or a point on the third surface 7, and a shaft member 12, serving as a rotation support for rotatably supporting the first reference surface 10a, with an axis extending perpendicularly to the bottom surface 9a used as a rotation center.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a cutting system, and more particularly to a cutting system suitable for cutting artificial bone to be filled in a gap of an opening part in osteotomy, for example.

Background Art

[0002] <8000009>In knees deformed by osteoarthritis or the like, cases are sometimes seen where only the cartilage on one side is painful because the burden on the knee is concentrated on one side.

[0003] Peri-knee osteotomy is a surgery that corrects the alignment of the knee by making incisions in the tibia or femur and opening or closing the bone, and shifting the position where the load is applied to a painless part. There are various surgical methods, and one of them is a method of opening and correcting the bone with the tip of the incision made in the bone as the rotation axis.

[0004] In this method, after alignment correction, a gap occurs in the opened part of the bone. Therefore, in addition to fixing with a metal plate and screws to maintain the corrected position, an artificial bone is filled in the gap to reinforce it.

[0005] The shape of this gap varies depending on the bone morphology and the amount of correction. In order to appropriately maintain the amount of correction and promote early fusion between the artificial bone and the bone, it is necessary to fill an artificial bone that matches the gap generated after bone cutting and contacts the bone over a wide range.

[0006] The artificial bone is cut during surgery and adjusted to a shape that matches the gap part. Conventionally, for example, the tools described in Patent Document 1 below are known as the tools used at this time.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

[0008] The shape of the artificial bone to be implanted in the osteotomy site is determined by creating a preoperative plan based on X-ray information to determine the appropriate amount of correction, measuring the bone correction angle and the distance from the bone end to the center of rotation, or by measuring the angle of the opening, the opening width, and the distance from the correction center of the width measurement point during the actual correction during surgery. The correction angle and opening width during surgery can be measured with a goniometer, calipers, or ruler, and the distance from the center of rotation can be calculated from the amount of wire or other materials inserted.

[0009] When processing artificial bone using the jig described in Patent Document 1, it is necessary to mark the cutting position using a skin pen or the like to achieve the shape determined by the above method, and then make fine adjustments so that the processing blade passes along the marked line.

[0010] Therefore, even if the shape of the artificial bone to be processed is optimal, errors can occur due to differences in the accuracy of the marked lines, differences in the perception of which position on the line is appropriate for the cutting tool to pass through, and the precision of the operation to place the artificial bone in the area where the cutting tool passes. Furthermore, performing this operation carefully can lead to an extension of the surgery time.

[0011] In view of the above, the present invention aims to provide a cutting system that can process a block into a triangular or wedge shape with high precision and speed without performing a scoring operation on the block. [Means for solving the problem]

[0012] To achieve this objective, the present invention provides a cutting system for cutting a block body having a first surface, a second surface, and a third surface that intersect each other, using a cutting tool, comprising: a gripping device for gripping the block body; a support base on which the cutting tool is provided; and a guide mechanism for holding the gripping device so as to be movable relative to the support base, wherein the gripping device comprises: a bottom having a bottom surface in contact with the first surface of the block body; a first reference member having a first reference surface in contact with the second surface of the block body; and the third surface of the block body or a point on the third surface. The gripping device has a second reference member having a second reference surface in contact with it, and a rotating support part that rotatably supports the first reference surface with an axis extending perpendicular to the bottom surface as the center of rotation, the first reference member having a support receiving part connected to the rotating support part, the second reference member being connected to the first reference member and configured to move relative to the axis along the first reference member, and the gripping device moves relative to the processing cutting tool on the support base to process the first surface of the gripped block body in a manner that divides it.

[0013] According to the present invention, by fixing the block body to the bottom with a gripping device, rotating the first reference member around an axis extending perpendicular to the bottom surface as the center of rotation, and setting the angle between the first reference surface of the first reference member and the cutting direction by the cutting tool to a desired angle, the block body can be processed into a triangular or wedge shape with high precision and speed without performing a scoring operation on the block body.

[0014] Furthermore, in the present invention, the gripping device has a top plate facing the bottom surface of the bottom, and is configured to fix the block body by contacting the top plate with the block body, thereby connecting the top plate and the bottom surface. The top plate allows the block body to be firmly fixed by sandwiching it with the bottom.

[0015] Furthermore, the top plate is divided into two sections that straddle the passage of the cutting tool. This prevents interference between the top plate and the cutting tool as it passes through.

[0016] Furthermore, in the present invention, a rod portion with the aforementioned shaft as its central axis can be used as the rotational support portion of the gripping device.

[0017] Furthermore, in the present invention, a substantially arc-shaped rail centered on the axis can be used as the rotation support portion of the gripping device.

[0018] Furthermore, in the present invention, the rotating support portion and the support receiving portion are supported by a first support column extending parallel to the bottom surface of the bottom portion and a second support column extending perpendicularly upward with respect to the bottom surface of the bottom portion, and are positioned above the block body on the bottom portion without intersecting. This prevents interference between the rotating support portion and the support receiving portion and the machining tool.

[0019] Furthermore, in the present invention, it is preferable to have an angle display unit that displays the angle between the first reference member and the passage portion of the processing tool. This allows the angle display unit to be easily checked when setting the block body, enabling smooth operation.

[0020] Furthermore, in the present invention, it is preferable to have a length display section that indicates the distance between the second reference surface of the second reference member and the axis. This allows the length display section to be easily checked when setting the block body, enabling smooth operation.

[0021] Furthermore, the present invention is characterized in that the shaft is located on the passage portion of the cutting tool. This allows for high-precision machining of block bodies.

[0022] Furthermore, the present invention is characterized in that the shaft is located on the side surface of the machining tool or on a surface in contact with the side surface. This allows for even higher precision machining of the block body, taking into account the thickness of the machining tool. [Brief explanation of the drawing]

[0023] [Figure 1] Side view showing the schematic configuration of an embodiment of the present invention. [Figure 2] Perspective view of the block body. [Figure 3] FIG. 3A is a plan view of the gripping device, and FIG. 3B is a side view of FIG. 3A. [Figure 4] FIG. 4A is an explanatory plan view of the main part of the gripping device, and FIG. 4B is a side view of FIG. 4A. [Figure 5] Plan view of the receiving base. [Figure 6] Explanatory drawing showing the state after osteotomy around the knee joint. [Figure 7] Explanatory plan view of the usage state of the main part of the gripping device. [Figure 8] FIG. 8A is a plan view showing the operation of the cutting system, FIG. 8B is a plan view showing the subsequent operation of FIG. 8A, and FIG. 8C is an explanatory drawing showing the state of the artificial bone on the gripping device of FIG. 8B. [Figure 9] FIG. 9A is a plan view of the cut surface of the tibia after osteotomy, and FIG. 9B is a drawing showing the state of filling with the artificial bone. [Figure 10] FIG. 10A is a plan view of the gripping device of another embodiment, and FIG. 10B is a side view of FIG. 10A. [Figure 11] FIG. 11A is a plan view of the gripping device of another embodiment, and FIG. 11B is a side view of FIG. 11A. [Figure 12] Plan view of a modification of FIG. 10. [Figure 13] Plan view showing an example of the scale provided on the bottom surface of the bottom.

Mode for Carrying Out the Invention

[0024] An embodiment of the present invention will be described based on the drawings. As shown in FIGURE 1, the cutting system of this embodiment includes a gripping device 1 for gripping a block body, a cutting tool 2 for cutting the block body, and a guide mechanism 3 for guiding the movement of the gripping device 1.

[0025] In this embodiment, the block body 4 to be processed is a rectangular thick plate material, as shown in Figure 2. The cutting system of this embodiment cuts out artificial bone from the block body 4 to fill the gap created by cutting and opening the bone during osteotomy. In this embodiment, the wide surface corresponding to the flat surface of the block body 4 is designated as the first surface 5, the thickness surface on the long side is designated as the second surface 6, and the thickness surface on the short side is designated as the third surface 7.

[0026] The block body 4 used as artificial bone is preferably made of ceramics, and in particular, bioceramics such as alumina, zirconia, calcium phosphate compounds, and calcium carbonate compounds are preferred. Ceramic blocks are easy to process. However, the block body 4 is not limited to these materials and may be formed from harvested bone or other materials.

[0027] Next, the configuration of the cutting system of this embodiment will be described. As shown in Figures 3A and 3B, the gripping device 1 comprises a top plate 8, a bottom 9, a first reference member 10, and a second reference member 11.

[0028] Figure 3A is a plan view of the gripping device 1 with its top surface covered by the top plate 8, while Figure 4A is an explanatory plan view in which the top plate 8 has been removed for ease of explanation, exposing the main components of the gripping device 1.

[0029] As shown in Figure 4A, the bottom portion 9 is formed as a long rectangle in plan view, with its flat upper surface being the bottom surface 9a that contacts the first surface 5 of the block body 4. That is, the block body 4 is placed on the bottom portion 9 of the gripping device 1. A slit extending along the longitudinal direction is formed in the center of the bottom portion 9. This slit is provided as a passage portion 9b for the processing tool 2 to pass through.

[0030] As shown in Figure 4A, the first reference member 10 is formed in a shape that extends in the longitudinal direction of the bottom portion 9 and has a first reference surface 10a on one side that is in contact with the second surface of the block body. The base end of the first reference member 10 is pivotally attached to a rod-shaped shaft member 12 so as to be rotatable, and its tip points to the inner surface of the curved arc member 13. The shaft member 12 is supported by a support receiving portion 14.

[0031] The arc member 13 is provided with an angle indicator 15 that shows the angle of the first reference surface 10a with respect to the passage portion 9b of the machining tool 2. In this embodiment, the arc member 13 is shown with the angle indicator 15, but it is not limited to this. For example, although not shown, the angle indicator 15 may be displayed directly on the bottom surface 9a of the bottom portion 9.

[0032] The center of the shaft member 12 is the axis of the rotating first reference member 10, and the shaft member 12 is the rod portion and corresponds to the rotation support portion in this invention.

[0033] The shaft member 12 can fix the rotation of the first reference member 10 at a desired position (a desired angle with respect to the passage portion 9b of the cutting tool 2) by rotating the grip portion 16. Although not shown in the figures, the tip side of the first reference member 10 may be guided by an arc member 13. In this configuration, the angle of the first reference surface 10a can be set to a desired angle without providing the shaft member 12. In this configuration, the arc member corresponds to the rail of the present invention.

[0034] Furthermore, as shown in Figure 4B, the shaft member 12 is supported by the first support column 17 and the second support column 18 together with the support receiving portion 14.

[0035] The first support column 17 extends parallel to the bottom surface 9a of the base 9, and the second support column 18 extends vertically upward relative to the bottom surface 9a of the base 9. The first support column 17 supports the shaft member 12 on the passage portion 9b of the cutting tool 2 in a plan view. The second support column 18 extends downward from a position shifted to one side and intersecting the shaft member 12, and its lower end is connected to the base end of the first reference member 10.

[0036] In this way, the first support column 17 and the second support column 18 support the shaft member 12 at a position higher than the block body 4 placed on the bottom 9, and the first reference member 10 is supported at a position shifted to one side of the passage portion 9b of the processing tool 2 (see Figure 4A).

[0037] As shown in Figure 4A, the second reference member 11 is connected to the first reference member 10 and has a second reference surface 11a on one side that is in contact with the third surface 7 of the block body 4 or a point on the third surface 7.

[0038] The second reference member 11 is provided so as to be movable along the longitudinal direction of the first reference member 10 and is equipped with a rod-shaped operating part 19 that extends laterally outward from the bottom 9.

[0039] The operating unit 19 can slide the second reference member 11 along the longitudinal direction of the first reference member 10, and by rotating the operating unit 19, the second reference member 11 can be fixed at a desired position along the longitudinal direction of the first reference member 10.

[0040] Preferably, the operating section 19 is formed to extend outward beyond one lateral edge of the bottom 9, so that the operating section 19 can be operated without the bottom 9 getting in the way.

[0041] Furthermore, the first reference member 10 is provided with a length indicator 20 that shows the distance from the center of the shaft member 12 to the second reference surface 11a.

[0042] As shown in Figure 3B, the top plate 8 is positioned above the bottom surface 9a of the bottom portion 9 and is provided parallel to and opposite the bottom surface 9a of the bottom portion 9. The top plate 8 grips and fixes the block body 4 by sandwiching it between itself and the bottom surface 9a.

[0043] As shown in Figure 3A, the top plate 8 is provided in pairs on both sides of the bottom 9 via a slit (a passage 9b for the cutting tool 2 to pass through) formed in the bottom 9, and each of them is provided at the tip of the bottom 9 via a hinge 21 so as to be able to swing upright. This allows the top plate 8 to swing upright on only one side to expose the first reference member 10 and the second reference member 11.

[0044] The top plate 8 may be in direct contact with the block body 4, but a resin such as silicone rubber (not shown) may be provided in the contact area with the block body 4. This prevents damage to the block body 4 and allows it to be gripped even if each surface of the block body 4 has irregularities.

[0045] Furthermore, the top plate 8 has notches 22 formed at positions corresponding to the shaft member 12, the support receiving portion 14, and the first support column 17, thereby preventing the top plate 8 from interfering with the shaft member 12 and the support receiving portion 14.

[0046] The first reference member 10 and the second reference member 11 are formed so that their height is lower than that of the top plate 8, thereby enabling the block body 4 to be securely gripped by the top plate 8 and the bottom 9.

[0047] Furthermore, it is preferable that the gripping device 1 be provided with a rod-shaped handle 23. This makes it easier to move the device on the guide mechanism 3, which will be described later.

[0048] As shown in Figure 5, the cutting tool 2 and the guide mechanism 3 are integrally connected by the support base 24. For the sake of explanation, Figure 5 is a plan view with the gripping device removed from the state shown in Figure 1.

[0049] The cutting tool 2 is attached to the tip of a rotating shaft 26 that extends from a drive unit 25 supported on a support base 24. The cutting tool 2 used in this embodiment is, for example, a circular saw used in orthopedic surgeries such as open reduction and internal fixation of fractures, artificial joint replacement, and ligament repair.

[0050] The guide mechanism 3 comprises a pair of parallel straight rails 27. The cutting tool 2 is positioned in the center of both straight rails 27, and the axis of the rotation shaft 26 is set to be perpendicular to the longitudinal direction of both straight rails 27. The two straight rails 27 then slide and guide the gripping device 1.

[0051] Next, as an example, we will explain the processing steps using the cutting system of this embodiment, using artificial bone for knee osteotomy.

[0052] As shown in Figure 6, the dimensions of the artificial bone corresponding to the gap W formed by correction after osteotomy are determined. Specifically, the osteotomy length (base dimension X) and the angle (correction angle θ) when the gap W is corrected with its end P as the center of rotation are determined.

[0053] If the correction angle θ is unknown, the correction angle θ can be calculated using the base dimension X and the opening width dimension Z. If the base dimension X is unknown, the base dimension X can be calculated using the correction angle θ and the opening width dimension Z.

[0054] Next, as shown in Figure 7, the first reference member 10 of the gripping device 1 is rotated, and the first reference member 10 is fixed when the angle of the first reference surface 10a matches the correction angle θ. The angle of the first reference surface 10a can be easily confirmed by the angle indicator 15 of the arc member 13.

[0055] Similarly, the second reference member 11 is slid and fixed in place when the position of the second reference surface 11a matches the base dimension X. The position dimension of the second reference surface 11a can be easily confirmed by the length indicator 20 of the first reference member 10.

[0056] Next, the block body 4 is placed on the bottom 9. At this time, the second surface 6 of the block body 4 is brought into contact with the first reference surface 10a of the first reference member 10, and a part of the third surface 7 of the block body 4 (the end on the corner side) is brought into contact with the second reference surface 11a of the second reference member 11.

[0057] Next, the top plate 8 is closed and the gripping device 1, which is gripping the block body 4, is set on the upstream side of the guide mechanism 3 (initial position separated from the cutting tool 2), as shown in Figure 8A.

[0058] Then, as shown in Figure 8B, with the cutting tool 2 rotating, the gripping device 1 on the guide mechanism 3 is slid downstream guided by the straight rail 27. As a result, the block body 4 passes through the cutting tool 2, and artificial bone 4a cut from the block body 4 is obtained, as shown in Figure 8C with the top plate 8 removed.

[0059] By the way, to further explain the usage of the gripping device 1 with reference to Figure 7, if the base dimension X is smaller than the length dimension of the second face 6 of the block body 4, the artificial bone cut from the block body 4 will be triangular, and if the base dimension X is larger than the length dimension of the second face 6 of the block body 4, the artificial bone cut from the block body 4 will be quadrilateral.

[0060] In this case, since the taller end is the end of the bone, it is possible to obtain an artificial bone with a shape suitable for filling in the area near the cortical bone.

[0061] Furthermore, as shown in Figure 9A, the tibial cross-sectional shape formed by periprosthetic osteotomy is approximately triangular in plan view, so the base dimension X differs depending on the measurement position (see the dimensions indicated by symbols X1, X2, and X3 in the figure). Although the correction angle θ does not change depending on the measurement position, the opening width dimension Z also differs because the base dimension X is different.

[0062] In such cases, referring to Figure 7, the position of the second reference plane 11a is set to a position larger than the base dimension X, and the second reference member 11 is fixed there. This makes it possible to create a slightly longer artificial bone 4a, as shown in Figure 9B, and by excising the protruding portion 4b after implantation, it becomes possible to properly implant the artificial bone 4a up to the end of the bone shown by the dashed line in the figure.

[0063] As described above, by using a cutting system equipped with a gripping device 1, marking on the block material is unnecessary, and highly accurate artificial bone 4a can be obtained quickly.

[0064] In this embodiment, we have described the processing of artificial bone when filling gaps that occur during bone correction. However, by using the cutting system of the present invention, triangles and quadrilaterals having two opposing faces at any angle can be obtained, and these can be used to process graft materials for various cases.

[0065] Furthermore, the cutting system of the present invention is preferably formed by selectively using metal materials such as stainless steel, titanium, or titanium alloy for each part. It is also preferable that a part of it be made of a resin such as silicone rubber.

[0066] Furthermore, various types of cutting tools can be used in the cutting system of the present invention, including manual, electric, and pneumatic types. However, when using a rotary blade, a blade with a diameter of 25 mm or more and 40 mm or less is desirable. If the diameter of the rotary blade is less than 25 mm, uncut material will remain in the thickness direction, and if it is greater than 40 mm, the blade may protrude excessively and interfere with the work during processing.

[0067] Furthermore, a preferred positional relationship between the top plate of the gripping device and the cutting tool in the cutting system of the present invention is to set it so that the cutting tool does not protrude from the top plate.

[0068] Furthermore, when the cutting system of the present invention is used for processing grafts for artificial bone in bone correction surgery, the adjustment range and reading range of the angle between the path of the processing blade corresponding to the correction angle after osteotomy and the first reference surface may be 2° to 25°, and more preferably 3° to 15°. The adjustment range and reading range from the axis of the first reference member corresponding to the base dimension after osteotomy to the second reference surface may be 30mm to 90mm, and more preferably 40mm to 75mm. This makes the cutting system compact and suitable for use in the surgical field.

[0069] On the other hand, when the block material consists of a rectangular parallelepiped, by setting the angle between the path of the processing tool and the first reference plane to 90°, the block material can be accurately divided into multiple rectangular parallelepipeds, and multiple artificial bones can be created using multiple blocks divided from a single block as material.

[0070] Furthermore, if the width of the surface of the second reference surface of the second reference member that contacts the third surface of the block material is large, it will interfere with the passage of the cutting tool. Therefore, the width of this part should be 0.5 mm to 6 mm, preferably 2.5 mm to 4.5 mm. This ensures sufficient contact area with the block body and allows the block material to be securely fixed.

[0071] Furthermore, in order to define the fixing position of the block body, it is preferable to set the angle at which the first reference plane and the second reference plane intersect to match the angle at which the first face and the second face of the block body intersect.

[0072] Another embodiment, the simplest gripping device, is shown in Figures 10A and 10B. This device comprises a base 9, a first reference member 10, and a second reference member 11. However, since a shaft member 12 is present at the end of the section 9b through which the cutting tool passes, the artificial bone that can be created from the block is rectangular.

[0073] Therefore, as shown in Figures 11A and 11B, interference between the machining tool and the shaft member 12 can also be prevented by adopting a configuration in which the shaft member 12 is offset below the passage portion 9b of the machining tool 2, and the machining tool moves above the bottom portion 9.

[0074] Furthermore, as shown in Figure 12, a scale 28 may be provided on the second reference member 11. This allows the first reference member 10 and the second reference member 11 to be adjusted according to the opening width after bone cutting by checking the scale 28.

[0075] The scale 28 can be rotated via the pivot 29 to a position away from the passage portion 9b, or it can be detachably mounted to prevent interference with the cutting tool.

[0076] Furthermore, as shown in Figure 13, a scale 30 indicating the distance from the passing portion 9b may be provided on the bottom surface 9a of the bottom portion 9. This also allows the first reference member 10 and the second reference member 11 to be easily and accurately adjusted according to the opening width dimension after bone cutting. [Explanation of symbols]

[0077] 1...Gripping device 2… Cutting tools 3… Guide mechanism 4…Block letters 5…Front page 6…Second side 7…Third side 8... Tabletop 9...Bottom 9a…Bottom surface 9b…passing section 10…First reference member 10a...First reference plane 11…Second reference member 11a...Second reference plane 12…Shaft member (rotation support part, rod part) 14…Support receiving part 17…First support 18…Second support 24...Support stand

Claims

1. A cutting system for cutting a block body having a first surface, a second surface, and a third surface that intersect with each other using a processing blade, a gripping device that grips the block body, a receiving stand on which the cutting tool is provided, and a guide mechanism that holds the gripping device so as to be movable relative to the receiving stand, The gripping device includes a bottom having a bottom surface in contact with the first surface of the block body, a first reference member having a first reference surface in contact with the second surface of the block body, a second reference member having a second reference surface in contact with the third surface of the block body or a point on the third surface, and a rotation support part that rotatably supports the first reference surface around an axis extending perpendicular to the bottom surface, the first reference member has a support receiving portion connected to the rotation support portion, the second reference member is connected to the first reference member and configured for relative movement along the first reference member toward the axis; A cutting system characterized in that the gripping device moves relative to the processing blade of the receiving table, thereby processing the first surface of the gripped block body so as to divide it.

2. the gripping device has a top plate facing the bottom surface of the bottom portion, 2. The cutting system according to claim 1, wherein the top plate is configured to abut against the block body, thereby fixing the block body between the top plate and the bottom surface.

3. 3. The cutting system according to claim 2, wherein the top plate is divided into two parts across the passage of the cutting tool.

4. 4. The cutting system according to claim 1, wherein the rotation support portion of the gripping device is made of a rod portion having the shaft as a central axis.

5. 5. The cutting system according to claim 1, wherein the rotation support portion of the gripping device is formed of a rail having a substantially arcuate shape centered on the axis.

6. The cutting system according to any one of claims 1 to 5, characterized in that the rotation support portion and the support receiving portion are supported by a first support pillar extending parallel to the bottom surface portion of the bottom portion and a second support pillar extending upward perpendicular to the bottom surface portion of the bottom portion, and are positioned at an upper position that does not intersect with the block body on the bottom portion.

7. The cutting system according to any one of claims 1 to 6, wherein the shaft is present on a passage portion of the processing blade.

8. 8. The cutting system according to claim 1, wherein the shaft is located on a side surface of the cutting tool or on a surface in contact with the side surface.

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