Bone broach

Abstract

To provide a bone broach that can broach a bone hole and can position a hole for an instrument at the same time.SOLUTION: A phalange broach 10 includes: a body 11 having a first surface 20 perpendicular to a first direction; a broach blade 14 extending in the first direction from the first surface 20 of the body 11; a shaft 15 extending from the body 11 in a second direction opposite to the first direction; and a first through-hole 12 and a second through-hole 13 formed in the body 11, extending along the first direction, and opening in the first surface 20.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a bone broach used for broaching in total joint replacement surgery. [Background technology]

[0002] As an example of an instrument for drilling holes in bones during total joint replacement surgery, Patent Document 1 discloses a drilling tool with a cylindrical blade formed at the lower end of a pipe and a handle at the upper end of the pipe. The drilling tool is used to drill a reference hole for an alignment guide in the femur. The cylindrical blade is placed on a reference mark on the distal end of the femur, and the handle is struck with a hammer or other striking tool to drill the reference hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2003-153915 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when an implant is fixed to a bone, a bone hole is formed, but when forming multiple bone holes, it is necessary to form the other bone holes using one bone hole as a reference. For example, while positioning and holding a guide member on the end face of the bone at the reference hole, further holes are drilled in the end face of the bone along the guide member, but such a procedure requires the practitioner to be skilled.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide a bone broach that can form another bone hole in an appropriate position based on one bone hole when placing an implant in a bone. [Means for solving the problem]

[0006] (1) The bone broach of the present invention comprises a body having a plane perpendicular to a first direction, a broach blade extending from the plane of the body in the first direction, a shaft extending from the body in a second direction opposite to the first direction, and a through hole formed in the body, extending along the first direction and opening into the plane.

[0007] The practitioner can broach the hole in the bone by inserting the broach blade into the hole in the bone and rotating it by holding the shank. After that, the practitioner can grasp the main body with the flat surface abutting the end face of the bone, making it easy to position the main body relative to the bone. While grasping and positioning the main body relative to the bone, the practitioner can further drill a hole in the bone through the through-hole of the main body.

[0008] (2) The shank may be aligned along the rotation axis of the broach blade.

[0009] The broach blade can be easily rotated around the rotation axis.

[0010] (3) The main body may have a positioning mark on the outer peripheral surface that intersects with the plane.

[0011] The body can be easily positioned relative to the bone by aligning the markings on the bone with the markings on the body.

[0012] (4) The through-hole may be plural.

[0013] (5) The main body may be a columnar body that is elongated along the first direction.

[0014] The practitioner can easily grasp the main body.

[0015] (6) The minimum dimension of the outer shape of the main body in a transverse direction intersecting with the axis of the shaft portion is greater than the maximum dimension of the outer shape of the shaft portion in the transverse direction.

[0016] It is easy for the practitioner to align the mark with the mark.

[0017] 3. The bone brooch according to claim 1, wherein the bone brooch is a brooch for a phalange. [Effects of the Invention]

[0018] According to the present invention, when placing an implant in a bone, one bone hole can be used as a reference to form another bone hole at an appropriate position. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view showing an example of a phalangeal broach 10 according to this embodiment, together with a middle phalange 51 on the proximal interphalangeal joint side. [Figure 2] FIG. 2 is a perspective view showing an example of a phalangeal broach 10 according to this embodiment. [Figure 3] FIG. 3 is a front view of the phalangeal broach 10 shown in FIG. [Figure 4] FIG. 4 is a view of the phalange broach 10 shown in FIG. 2 as seen from the left. [Figure 5] FIG. 5 is a diagram for explaining the procedure for cutting the bone hole 53 with the phalangeal broach 10. As shown in FIG. [Figure 6] FIG. 6 is a diagram for explaining the procedure for aligning the mark 30 with the mark 66. In FIG. [Figure 7] Figure 7(a) is a diagram for explaining the procedure for drilling holes in the cutting surface 52, and Figure 7(b) is a diagram showing the state in which a first hole 57 and a second hole 58 have been drilled in the cutting surface 52. [Figure 8] FIG. 8 is a diagram showing a state in which the middle phalanx side implant 60 has been temporarily placed. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings as appropriate. Note that the embodiment described below is merely an example of the present invention, and it goes without saying that the embodiment of the present invention can be appropriately modified without departing from the spirit and scope of the present invention.

[0021] In the following description, as shown in FIG. 1 , the direction toward the tip of the broach blade 14 is defined as the front, the direction toward the base end as the rear, and the direction along the center line 24 (an example of a rotation axis) of the broach blade 14 is defined as the front-rear direction 1. The direction toward which the upper surface 26 of the main body 11 faces is defined as the upward direction, the direction toward which the lower surface 27 faces is defined as the downward direction, and a direction perpendicular to the front-rear direction 1 and perpendicular to the upper surface 26 and the lower surface 27 is defined as the up-down direction 2. When viewed from behind along the center line 24 of the broach blade 14, the direction toward the left is defined as the leftward direction, and the direction toward the right is defined as the rightward direction. The direction perpendicular to the front-rear direction 1 and the up-down direction 2 is defined as the leftward direction.

[0022] As shown in FIG. 1, a phalangeal broach 10 (an example of a bone broach) broaches a phalange. The phalangeal broach 10 is used, for example, in artificial finger joint replacement surgery. Artificial finger joint replacement surgery is a treatment performed when the head of a finger joint and the glenoid cavity where the head slides can no longer perform their original joint function due to osteoarthritis, rheumatoid arthritis, or the like. In artificial finger joint replacement surgery, an implant (only the implant on the middle phalange 51 side is shown in FIG. 8) made of metal such as titanium alloy or cobalt-chromium alloy or resin is placed.

[0023] The phalangeal broach 10 is made of metal such as stainless steel. In this embodiment, the phalangeal broach 10 is used to broach a bone hole 53 drilled in a cutting surface 52 of the glenoid cavity of the middle phalanx 51. As shown in FIG. 2 , the phalangeal broach 10 has a main body 11, a first through hole 12 (an example of a through hole), a second through hole 13 (an example of a through hole), a broach blade 14, and a shaft 15.

[0024] As shown in Figures 2 and 3, the main body 11 is a columnar body extending in the front-rear direction 1, and has a substantially trapezoidal cross-sectional outer shape in the up-down direction 2 and the left-right direction 3 (an example of an intersecting direction). The main body 11 is a slender columnar body whose length in the front-rear direction 1 is longer than its lengths in the up-down direction 2 and the left-right direction 3. The main body 11 has a first surface 20 (an example of a flat surface) facing forward, a second surface 21 (see Figure 1) facing rearward, and an outer peripheral surface 22 that intersects with the first surface 20 and the second surface 21. The first surface 20 and the second surface 21 each have a substantially trapezoidal outer shape. The first surface 20 and the second surface 21 are parallel flat surfaces.

[0025] As shown in Figures 1, 2, and 3, the outer peripheral surface 22 includes a flat upper surface 26 facing upward, a flat lower surface 27 facing downward, a flat left surface 28 facing diagonally upward and left, and a flat right surface 29 facing diagonally upward and right. The upper surface 26 is parallel to the lower surface 27 and is smaller than the lower surface 27 when viewed in the up-down direction 2. The upper surface 26 is connected to the left surface 28 and the right surface 29 by curved surfaces. The lower surface 27 is connected to the left surface 28 and the right surface 29 by curved surfaces. The distance between the upper surface 26 and the lower surface 27 is smaller than the distance between the left surface 28 and the right surface 29 in the left-right direction 3.

[0026] 1 and 2, a triangular mark 30 is marked on the top surface 26. The mark 30 is located at the front end of the top surface 26 and at the center of the top surface 26 in the left-right direction 3. The apex of the triangle in the mark 30 faces forward.

[0027] 2 and 3, a first through hole 12 and a second through hole 13 (hereinafter also referred to as the through holes 12 and 13) are formed in the main body 11. The through holes 12 and 13 function as guides for drilling a first hole 57 (see FIG. 7(b)) and a second hole 58 (see FIG. 7(b)) in the cutting surface 52 of the middle phalanx 51.

[0028] Each of the through holes 12, 13 has a circular shape when viewed in the front-rear direction 1, and penetrates the main body 11 in the front-rear direction 1. As shown by the dashed dotted line in FIG. 2, the axis 31 of the first through hole 12 and the axis 32 of the second through hole 13 are aligned along the front-rear direction 1. The axis 31 is spaced leftward and downward from the center line 24 of the broach blade 14 (shown by the two-dot chain line in FIG. 2). The axis 32 is spaced rightward and downward from the center line 24 of the broach blade 14.

[0029] The first through hole 12 opens to the first surface 20 and the second surface 21. The periphery of the opening of the first through hole 12 in the second surface 21 is chamfered. The second through hole 13 opens to the first surface 20 and the second surface 21. The periphery of the opening of the second through hole 13 in the second surface 21 is chamfered.

[0030] A broach blade 14 is located on the first surface 20 of the main body 11. The broach blade 14 broaches the bone hole 53. As shown in Figures 2 and 4, the broach blade 14 extends forward from the first surface 20 (an example of a first direction). The broach blade 14 has a generally diamond-shaped cross section and has a cutting edge 35 at its tip. The broach blade 14 has a center line 24 that runs along the anterior-posterior direction 1. The center line 24 passes through the intersection of the diagonals of the diamond and extends along the anterior-posterior direction 1. The broach blade 14 is shorter than the main body 11 in the anterior-posterior direction 1. The broach blade 14 has a tapered cross section that gradually becomes smaller moving forward from the main body 11. The cutting edge 35 is a quadrangular pyramid shape, with the apex located at the front end.

[0031] As shown in Figures 1 and 4, the shank 15 is located on the second surface 21. The shank 15 is the part that is gripped by the practitioner when the phalangeal broach 10 is rotated. The shank 15 has a generally columnar shape and extends rearward (an example of the second direction) from the second surface 21. The central axis of the shank 15 is coaxial with the center line 24. The length of the shank 15 in the front-to-rear direction 1 is longer than the length of the main body 11 in the front-to-rear direction 1.

[0032] The shank 15 has a first portion 37 that is continuous with the second surface 21, and a second portion 38 that extends rearward from the first portion 37. The first portion 37 and the second portion 38 are located on the center line 24 of the broach blade 14 along the front-to-rear direction 1. The first portion 37 is generally cylindrical. The second portion 38 has a cylindrical outer peripheral surface that is processed into a plurality of corrugated patterns that extend in the front-to-rear direction 1. The outer diameter of the second portion 38 is smaller than the distance between the upper surface 26 and the lower surface 27 of the main body 11.

[0033] [Procedure using the phalange broach 10] In this embodiment, a procedure for placing an implant 60 on the middle phalanx side of the proximal interphalangeal joint will be described. Specifically, an incision is made near the proximal interphalangeal joint, and the middle phalanx 51 is folded upward relative to the proximal phalanx to expose the glenoid cavity of the middle phalanx 51. At this time, the collateral ligament is located between the proximal end of the middle phalanx 51 and the distal end of the proximal phalanx. For ease of explanation, FIGS. 5 to 8 show the middle phalanx 51 with the dorsal side facing upward and the proximal end facing backward.

[0034] First, although not shown, a guide member is used to insert a steel wire 62 into the bone shaft of the middle phalanx 51, and the cutting surface 52 of the glenoid cavity is cut with a bone cutting tool so as to be flat.

[0035] Thereafter, as shown in FIG. 5 , the bone hole 53 in the middle phalanx 51 is expanded to a predetermined size with the phalangeal broach 10, and the first through hole 12 and the second through hole 13 of the phalangeal broach 10 are positioned on the cutting surface 52. Specifically, the practitioner removes the steel wire 62 from the middle phalanx 51 and inserts the broach blade 14 of the phalangeal broach 10 into the bone hole 53. The practitioner applies a forward load while gripping the shank 15 and rotating the phalangeal broach 10 by hand (see FIG. 5 ). At this time, the practitioner may also apply a load by gripping the main body 11. The practitioner drills the bone hole 53 until the first surface 20 abuts against the cutting surface 52. As a result, the bone hole 53 is expanded to a diameter large enough to fit the stem 67 of the middle phalanx-side implant 60 shown in FIG. 8 .

[0036] As shown in FIG. 6 , the practitioner grasps the body 11 while keeping the first surface 20 in contact with the cutting surface 52, and aligns the mark 30 on the body 11 with the mark 66 on the middle phalanx 51. At this time, the body 11 is easy to grasp because the outer dimensions of its cross section in the up-down direction 2 and the left-right direction 3 are larger than those of the shaft portion 15. The mark 66 is a line drawn with a skin pen or the like and is drawn on the upper end of the dorsal side of the middle phalanx 51. This positions the first through-hole 12 and the second through-hole 13 at a predetermined distance from the bone hole 53. This predetermined distance is the same as the distance between the stem 67 of the middle phalanx side implant 60 and the first pin 68 (see FIG. 8 ). The stem 67 is a pin that is fitted into the bone hole 53 when the middle phalanx side implant 60 is placed on the cutting surface 52. The first pin 68 is a pin that is fitted into the first hole 57 so that the middle phalanx side implant 60 does not shift in the rotational direction around the stem 67 as an axis. The predetermined dimension is also the same as the dimension of the separation between the stem 67 and the second pin (not shown). The second pin is a pin that is fitted into the second hole 58 so that the middle phalanx side implant 60 does not shift in the rotational direction around the stem 67 as an axis. The practitioner can drill the first hole 57 and the second hole 58 at accurate positions that correspond to the positions of the first pin 68 and the second pin of the middle phalanx side implant 60.

[0037] Next, as shown in FIG. 7(a), a steel wire 62 is inserted through the first through hole 12, and then the steel wire 62 is inserted through the second through hole 13. The steel wire 62 inserted through the first through hole 12 and the second through hole 13 is driven into the positions of the cutting surface 52 where the first through hole 12 and the second through hole 13 are positioned. Even if the steel wire 62 is inserted offset from the axes 31 and 32 of the through holes 12 and 13, it abuts against the chamfered portions and is guided into the through holes 12 and 13. As a result, as shown in FIG. 7(b), a first hole 57 is drilled at a position lower and shifted to the left on the cutting surface 52, and a second hole 58 is drilled at a position lower and shifted to the right.

[0038] Once the first hole 57 and the second hole 58 have been drilled, trials (not shown) simulating the middle phalanx side implant 60 and the proximal phalanx side implant (not shown) are temporarily placed to check whether the bone holes are properly formed and whether they slide properly. After proper bone hole formation and sliding are confirmed, the middle phalanx side implant 60 and the proximal phalanx side implant are placed, and the movement of the proximal interphalangeal joint is confirmed. If there are no problems, the incision is closed and the artificial finger joint replacement surgery is completed.

[0039] [Effects of this embodiment] The practitioner grips the shank 15 and rotates the phalangeal broach 10. This causes the broach blade 14 to expand the bone hole 53, performing broaching. After broaching, the practitioner can easily position the phalangeal broach 10 relative to the phalange while gripping the body 11 with the first surface 20 abutting against the cutting surface 52 of the phalange. The practitioner can drill a first hole 57 and a second hole 58 for an instrument in the phalange through the first through-hole 12 and the second through-hole 13 of the body 11 positioned relative to the phalange.

[0040] Since the shank 15 is aligned along the center line 24 of the broach blade 14, the practitioner can easily rotate the broach blade around the center line 24.

[0041] The practitioner can accurately position the positions of the first hole 57 and the second hole 58 on the cutting surface 52 by abutting the first surface 20 against the cutting surface 52 of the phalange and aligning the mark 30 with the mark 66 on the phalange.

[0042] Since the middle phalanx side implant 60 is fixed to the cutting surface 52 by multiple pins, including the stem 67, the first pin 68, and the second pin, the middle phalanx side implant 60 placed on the phalange can be more reliably prevented from shifting in the rotational direction than when it is fixed by a single pin.

[0043] The practitioner can securely grasp the phalange broach 10 by the body 11. This allows the practitioner to apply a large load to the broach blade 14 during work.

[0044] The practitioner does not need to perform the work of positioning the first hole 57 and the second hole 58 for drilling into the phalanges. In addition, since no new jigs or the like are required for this positioning, the work can be done easily without becoming complicated.

[0045] Since the main body 11 is thicker than the shank 15, the practitioner can rotate the phalangeal broach 10 with a greater force than when gripping the shank 15. This makes it easier for the practitioner to align the mark 30 with the mark 66.

[0046] [Variations] In the above-described embodiment, the central axis of the shank 15 is located on an extension of the center line 24, but this configuration is not limiting. The central axis of the shank 15 may be parallel to the center line 24 and may be located at a position that is not on an extension of the center line 24. For example, the shank 15 may be located between the first through hole 12 and the second through hole 13 or at the center of the second surface 21 in the up-down direction 2 and the left-right direction 3. The shank 15 may also extend from the second surface 21 in a direction inclined with respect to the center line 24. In other words, the shank 15 may be located at a position on the second surface 21 that does not overlap with the first through hole 12 and the second through hole 13.

[0047] In the above-described embodiment, the axis 31 of the first through hole 12 and the axis 32 of the second through hole 13 are described as being along the front-rear direction 1. More specifically, the axis 31 and the axis 32 may be slightly inclined with respect to the front-rear direction 1 or may be parallel to the front-rear direction 1.

[0048] In the above embodiment, the case where the mark 30 is marked on the top surface 26 of the main body 11 has been described as an example, but the present invention is not limited to this configuration. The main body 11 may not have the mark 30 marked on it, and may be positioned on the middle phalanx 51 based on the external shape of the main body 11, for example.

[0049] In the above embodiment, the case where the triangular mark 30 is marked on the top surface 26 of the main body 11 has been described as an example, but this is not limiting. The mark 30 may have a shape other than a triangle, such as an arrow or a line extending in the front-rear direction 1.

[0050] In the above embodiment, the phalangeal broach 10 has been described as having two through holes, the first through hole 12 and the second through hole 13, in addition to the bone hole 53, as an example, but the present invention is not limited to this configuration. In the case where only the bone hole 53 and the first hole 57 are formed in the cutting surface 52, the phalangeal broach 10 may have only the first through hole 12 in addition to the bone hole 53. In the case where the bone hole 53, the first hole 57, the second hole 58, and an additional hole are formed in the cutting surface 52, the phalangeal broach 10 may have three or more through holes in addition to the bone hole 53.

[0051] In the above-described embodiment, the main body 11 is longer in the front-rear direction 1 than in the up-down direction 2 and the left-right direction 3, but this is not limiting. The main body 11 may be longer in the up-down direction 2 or the left-right direction 3 than in the front-rear direction 1, or the dimensions in the up-down direction 2 and the left-right direction 3 may be longer than the dimension in the up-down direction 2.

[0052] In the above embodiment, the case where the outer peripheral surface 22 of the main body 11 is connected by a curved surface has been described as an example, but this configuration is not limited thereto. The main body 11 may have a shape in which the outer peripheral surface 22 is not curved, such as a triangular prism or a square prism. The main body 11 may be any shape that can be gripped by a practitioner so as to generate sufficient torque to cut bone and rotate it.

[0053] In the above embodiment, the broach blade 14 is integrally formed with the main body 11, but the present invention is not limited to this configuration. The broach blade 14 may be detachable from the main body 11.

[0054] In the above embodiment, the cross-sectional shape of the broach blade 14 is described as being approximately diamond-shaped, but this configuration is not limiting. For example, the cross-sectional shape of the broach blade 14 may be triangular, or may have a threaded shape. The broach blade 14 is only required to be able to cut the bone hole 53 in the depth direction and radial direction so that the stem 67 can be fitted therein.

[0055] In the above embodiment, the shaft 15 has been described as having a corrugated outer circumferential surface, but this is not a limitation. The outer circumferential surface of the shaft 15 may be knurled or blasted, for example, as long as it can prevent slippage when the practitioner applies rotational force.

[0056] In the above-described embodiment, the case where the shaft portion 15 extends rearward from the second surface 21 has been described as an example. More specifically, the shaft portion 15 may be detachable from the main body 11, or may be formed integrally with the main body 11.

[0057] In the above-described embodiment, an example was given in which the shaft portion 15 has a first portion 37 that is continuous with the second surface 21 and a second portion 38 that extends rearward from the first portion 37. However, the second portion 38 may be detachable from the first portion 37, or may be integral with the first portion 37.

[0058] In the above-described embodiment, the first through hole 12 and the second through hole 13 have chamfered portions on the periphery of their rear ends. However, the configuration of each through hole 12, 13 is not limited to this. For example, each through hole 12, 13 may also have a chamfered portion at its front end that connects to the first surface 20. Alternatively, each through hole 12, 13 may not have a chamfered portion.

[0059] In the above embodiment, the broach blade 14 is shorter than the main body 11 in the front-to-rear direction 1, but this is not limiting. The dimension of the broach blade 14 in the front-to-rear direction 1 may be greater than or the same as the main body 11.

[0060] In the above embodiment, the bone broach is used in artificial finger joint replacement surgery for the middle phalanx 51, but the present invention is not limited to this configuration. The bone broach may be used for phalanges other than the middle phalanx 51 of the finger joint. The bone broach may also be used in artificial joint replacement surgery for the shoulder joint, hip joint, knee joint, or the like.

[0061] In the above embodiment, the mark 66 for aligning the mark 30 on the main body 11 is provided on the upper end of the dorsal side of the middle phalanx 51, but the present invention is not limited to this configuration. The mark 66 may also be provided on the cutting surface 52.

[0062] In the above embodiment, the case where the distance between the stem 67 and the first pin 68 is the same as the distance between the stem 67 and the second pin has been described as an example, but this is not limiting. The distance between the stem 67 and the second pin may be different from the distance between the stem 67 and the first pin 68. [Explanation of symbols]

[0063] 10. Phalange brooch (bone brooch) 11. Main unit 12... First through hole (through hole) 13 Second through hole (through hole) 14 Broach blade 15 Shaft 20...1st surface (plane) 22...Outer surface 24 Center line (axis of rotation) 30 marks 57...1st hole 58...2nd hole

Claims

1. a body having a plane perpendicular to the first orientation; a broach blade extending from the plane of the body in the first direction; a shaft portion extending from the body in a second direction opposite to the first direction; a through hole formed in the body, extending along the first direction and opening onto the plane.

2. 2. The bone broach of claim 1, wherein said shank is aligned with an axis of rotation of said broach blade.

3. 3. The bone broach according to claim 1, wherein the body has a positioning mark on an outer peripheral surface thereof that intersects with the plane.

4. 3. The bone broach according to claim 1, wherein the through-hole is a plurality of holes.

5. 3. The bone broach according to claim 1, wherein the main body is a columnar body elongated along the first direction.

6. 3. The bone broach according to claim 1, wherein the minimum dimension of the outer shape of the body in a direction intersecting the axis of the shank is greater than the maximum dimension of the outer shape of the shank in the direction intersecting the axis of the shank.

7. 3. The bone broach according to claim 1, wherein the bone broach is a broach for a phalange.

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