Bone surgery instrument

Abstract

To provide a bone surgery instrument, when screwing a bone-cutting part forward and backward, capable of firmly gripping a bone to maintain a good pressure contact state and when moving a body part in a longitudinal direction, not damaging the bone and soft tissue.SOLUTION: A bone surgery instrument comprises: a hook-shaped support 10 having a support part 11 including a cylindrical portion on a proximal end side and a plate-shaped receiving part 12 facing the support part on a distal end side; a body section 20 that is formed of a cylindrical body having an outer diameter that can be inserted into the cylindrical portion of the support part and has a flange having an outer diameter that cannot be inserted into the cylindrical portion, on the proximal end side; a reverse movement prevention mechanism 30 that allows the body part supported by the support part to move in a distal direction and prevents it from moving in a proximal direction; and switching means 40 for activating and deactivating the reverse movement prevention mechanism, and when the reverse movement prevention mechanism is deactivated, the body part supported by the support part can move freely in the distal and proximal directions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to bone surgical instruments. [Background technology]

[0002] Osteotomy is performed to improve the symptoms of knee osteoarthritis, and one of the osteotomy techniques is DTO (distal-tuberosity osteotomy). DTO differs from HTO (high tibial osteotomy) in the location of the osteotomy relative to the tuberosity; in DTO, the osteotomy is performed distal to the tuberosity.

[0003] In DTO, when the knee moves, the patellar tendon attached to the proximal tibial fragment pulls on the tuberosity, applying a load in the direction away from the tibia. To minimize the load on the tuberosity, it is important to screw the tuberosity to the distal tibial fragment from anterior to posterior. Because nerves and blood vessels are present posteriorly in the tibia, it is important to place the screw in the appropriate direction in the tibia. To achieve this, a pilot hole must be drilled in the appropriate direction. A drill guide is used to drill the pilot hole.

[0004] As a bone surgical instrument for preventing the tip of a drill that has penetrated bone using a drill guide from being exposed to surrounding tissue, Patent Document 1 below proposes a bone surgical instrument that includes a hook-shaped post having a cylindrical support portion at its base end and a disk-shaped receiving portion at its tip end, and a cylindrical main body that is inserted into the support portion of the post and has a through hole into which a rod-shaped member such as a drill can be inserted, and the receiving portion is configured to receive one end of the rod-shaped member that penetrates the through hole in the main body.

[0005] Figure 12 shows an example of a bone surgical instrument described in Patent Document 1. In the figure, 4 is a support pillar, with a support part 4a disposed on the base end side of the support pillar 4 and a receiving part 3 disposed on the tip side of the support pillar 4. 2 is a main body part, and a pointed part 2b is formed at the tip of the main body part 2 that protrudes toward the receiving part 3 in order to stably grasp a bone.

[0006] A male thread 2c is provided on the outer peripheral surface of the main body 2. Furthermore, a female thread (not shown) that screws into the male thread 2c is formed on the inner peripheral surface of the support portion 4a. Forward rotation of the main body part 2 moves the main body part 2 in a direction approaching the receiving part 3 (towards the distal end), and reverse rotation of the main body part 2 moves the main body part 2 in a direction away from the receiving part 3 (towards the proximal end). When the rotation of the main body part 2 is stopped, the main body part 2 is positioned in the longitudinal direction relative to the support 4, and the distance between the tip of the main body part 2 and the receiving part 3 is fixed. This makes it possible to adjust the distance between the tip of the main body part 2 and the receiving surface 3a according to the thickness of the bone A, and to grasp bones A of various thicknesses using the main body part 2 and the receiving part 3.

[0007] FIG. 13 shows another example of the bone surgery instrument described in Patent Document 1. The bone surgery instrument shown in the figure is provided with a click mechanism for positioning the main body 2 in the longitudinal direction relative to the support part 4a. This click mechanism is formed on the outer peripheral surface (a portion of the circumferential area) of the main body 2 and comprises a plurality of grooves 2d arranged in the longitudinal direction of the main body 2, a protrusion 4c provided on one end of the support 4, and a biasing member 4d. The groove 2d has a shape that restricts movement of the main body 2 only in the direction approaching the receiving portion 3 (toward the distal end). In other words, this click mechanism is a ratchet mechanism (anti-reverse mechanism) that allows movement of the main body 2 only in the distal end direction and prevents movement toward the proximal end. The protrusion 4c is biased by the biasing member 4d toward the main body 2 and fits into the groove 2d. With the protrusion 4c fitted into the groove 2d, the main body 2 is positioned in the longitudinal direction relative to the support portion 4a. When a force of a certain magnitude or more is applied to the main body 2 in the longitudinal direction (toward the tip), the main body 2 moves toward the tip while pressing the protrusion 4c against the biasing force of the biasing member 4d. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2020 / 059405 Summary of the Invention [Problem to be solved by the invention]

[0009] However, with the bone surgical instrument shown in Figure 12, even after the operator rotates the main body 2 in the forward direction and moves it toward the tip, so that the tip (pointed end 2b) of the main body 2 reaches the bone A, the operator tends to further rotate the main body 2 in an attempt to securely grasp the bone A. In such a case, the tip 2b of the main body 2 may damage the bone (tibial tuberosity) A and the soft tissues attached thereto, such as the lateral knee ligament.

[0010] In the bone surgery instrument shown in Figure 13, even if an attempt is made to move the main body part 2 in the base direction to remove it from the support part 4a of the support post 4 after the screw is fastened to the distal bone fragment of the tibia, the protrusion 4c constituting the ratchet mechanism is fitted in the groove 2d, and therefore the main body part 2 cannot be moved in that direction. In this case, if the main body 2 is rotated around the central axis in an attempt to release the engagement between the groove 2d formed in a circumferential region of the outer peripheral surface and the protrusion 4c, the tip 2b of the main body 2 will damage the bone A (tibial tuberosity) and soft tissues such as the lateral knee ligament attached thereto, as described above.

[0011] The present invention has been made based on the above circumstances. The object of the present invention is to provide a bone surgical instrument that, during surgery to screw an osteotomy portion back and forth, can firmly grip the bone with the main body and receiving portion to maintain a good crimped state, and that does not damage the bone or soft tissue with the tip of the main body when the main body is moved toward the tip to increase the crimping force on the bone surface, or when the main body is moved toward the base to loosen the crimping force on the bone surface. [Means for solving the problem]

[0012] (1) The bone surgical instrument of the present invention comprises a hook-shaped support having a support part including a cylindrical portion at a base end (hand side) thereof and a plate-shaped receiving part facing the support part at a tip end thereof; a main body portion that is a cylindrical body having an outer diameter that can be inserted into the cylindrical portion of the support portion and has a flange on a base end side that has an outer diameter that cannot be inserted into the cylindrical portion; a back movement prevention mechanism that allows the main body portion supported by the support portion to move in a distal direction and prevents the main body portion from moving in a proximal direction; a switching means for activating or deactivating the reverse movement prevention mechanism, When the backflow prevention mechanism is released by the switching means, the main body portion supported by the support portion is configured to be able to move freely in the distal and proximal directions.

[0013] In a bone surgical instrument configured as described above, when the backstop mechanism is activated by the switching means, the backstop mechanism prevents the main body portion supported by the support portion from moving toward the proximal end (movement in a direction that would loosen the grip on the bone), so the bone can be firmly clamped between the main body portion and the receiving portion to maintain a good crimped state. Furthermore, when the backstop mechanism is released by the switching means, the main body portion can move freely toward the proximal end, so the main body portion can be separated from the surface of the bone without damaging the bone or soft tissue, and the bone surgical instrument can be easily removed.

[0014] (2) In the bone surgical instrument of the present invention, the back movement prevention mechanism comprises a ratchet mechanism having a plurality of grooves (ratchet teeth) arranged in the longitudinal direction of the main body on the outer circumferential surface of the main body, a protrusion (ratchet pawl) provided on the support part, and a biasing member that biases the protrusion so that the groove and the protrusion fit together, The switching means preferably comprises a switching lever that engages or separates the groove and the protrusion.

[0015] With a bone surgical instrument configured in this manner, the ratchet mechanism, which is a backflow prevention mechanism, can be activated by engaging the groove and protrusion with the switching lever, and the ratchet mechanism can be released by separating the groove and protrusion with the switching lever.

[0016] (3) In the bone surgical instrument of the present invention, the back movement prevention mechanism comprises a locking mechanism of forceps having a first tip portion hooked onto the flange of the main body portion and a second tip portion hooked onto the support portion, the locking mechanism limiting handle operation in a direction in which the tip portions open, The switching means is preferably a means or structure that the forceps has for activating and deactivating the locking mechanism.

[0017] With a bone surgical instrument having such a configuration, the locking mechanism of the forceps can be used as the backstop mechanism. This bone surgical instrument, which uses such forceps to grasp bones, is easy to use for the operator (doctor). Furthermore, forceps equipped with a locking mechanism are provided with means or structure for activating and releasing the locking mechanism, and therefore the means or structure of the forceps can be used as the switching means.

[0018] (4) In the bone surgical instrument of (3) above, it is preferable that the flange and the support part of the main body part have through holes or bottomed holes for hanging the first tip end and the second tip end of the forceps, respectively.

[0019] With a bone surgical instrument configured as described above, the first tip end portion is inserted into and hooked onto a through hole or bottomed hole formed in the flange of the main body portion through the opening on the base end side thereof, and the second tip end portion is inserted into and hooked onto a through hole or bottomed hole formed in the support portion through the opening on the tip end side thereof. By closing the handles of the forceps with the locking mechanism activated, the first tip end portion and the second tip end portion close without moving backward, and thus the main body portion can be moved only in the tip direction relative to the support portion. Furthermore, by releasing the locking mechanism of the forceps, the first tip portion and the second tip portion can be removed from the through hole or bottomed hole, thereby allowing the main body portion to be freely moved in either the tip direction or the base direction.

[0020] (5) In the bone surgical instrument of (4) above, a guide groove extending in the longitudinal direction is formed on one of the outer peripheral surface of the main body portion and the inner peripheral surface of the support portion, and a guide protrusion that can be fitted into the guide groove is formed on the other of the outer peripheral surface of the main body portion and the inner peripheral surface of the support portion, and it is preferable that when the guide groove and the guide protrusion are fitted together, the central axes of the through holes or the bottomed holes are aligned.

[0021] With a bone surgical instrument having such a configuration, the guide groove and the guide protrusion are engaged to prevent the main body supported by the support from rotating around its central axis, thereby reliably preventing the tip (pointed end) of the main body from damaging bones or soft tissues. Furthermore, when the guide groove and the guide protrusion are engaged, the central axes of the two through holes or bottomed holes into which the tip of the forceps is inserted (hooked) coincide, so that the operation of closing the forceps and moving the main body toward the tip (the operation of grasping the bone) can be performed reliably.

[0022] (6) In the bone surgery instruments described in (3) to (5) above, the forceps are preferably ratchet forceps.

[0023] (7) In the bone surgery instruments described above in (3) to (5), the forceps may be provided with a feed screw mechanism as the locking mechanism, which can limit the opening operation of the handles.

[0024] With a bone surgery instrument configured in this manner, by closing the handles of the forceps that make up the instrument and feeding the screw in the direction of closing the handles, the tip of the forceps can be closed without moving backward, and the main body can be moved only in the tip direction. In addition, the locking mechanism (reverse prevention mechanism) can be easily released by feeding the screw in the direction that the handle of the forceps opens.

[0025] (8) A bone surgical instrument according to the present invention comprises: a hook-shaped support having a support portion including a cylindrical portion at a base end thereof and a disk-shaped receiving portion at a tip end thereof, the center of which is on the central axis of the cylindrical portion; a main body portion that is made of a cylindrical body having an outer diameter that can be inserted into the cylindrical portion of the support portion and has a flange on a base end side that has an outer diameter that cannot be inserted into the cylindrical portion, The flange and the support portion of the main body are characterized in that a through hole or a bottomed hole is formed to which each of the tip portions (first tip portion and second tip portion) of the forceps that opens and closes can be attached.

[0026] According to the bone surgery instrument having such a configuration, the object of the present invention can be achieved by combining it with general-purpose forceps having a releasable locking mechanism (reverse movement prevention mechanism). [Effects of the Invention]

[0027] With the bone surgical instrument of the present invention, when performing surgery to fasten a bone resection section with screws back and forth (forming pilot holes and embedding screws, etc.), the backstop mechanism can be activated to firmly grasp the bone with the main body and receiving part, maintaining a good clamping state. After the surgery is completed, the back movement prevention mechanism can be released and the main body can be moved in the proximal direction, thereby loosening the pressure on the bone surface and removing the bone surgery instrument. Furthermore, since the main body can be moved toward the distal end and the proximal end without rotating around the central axis, bones and soft tissues will not be damaged by the distal end (pointed end) of the main body. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a perspective view showing a bone surgical instrument according to a first embodiment of the present invention. FIG. [Figure 2A]1 is a partially cutaway side view showing the bone surgical instrument according to the first embodiment (with the back movement prevention mechanism in operation). FIG. [Figure 2B] 1 is a partially cutaway side view showing the bone surgical instrument according to the first embodiment (with the back movement prevention mechanism released). FIG. [Figure 3] FIG. 10 is a perspective view showing a bone surgical instrument according to a second embodiment of the present invention. [Figure 4A] FIG. 10 is a side view showing the bone surgical instrument according to the second embodiment (with the locking mechanism activated). [Figure 4B] FIG. 10 is a side view showing the bone surgical instrument according to the second embodiment (with the locking mechanism released). [Figure 5] FIG. 10 is an explanatory view showing a support (support portion and receiving portion) constituting the bone surgical instrument of the second embodiment. [Figure 6A] FIG. 10 is an explanatory view showing a main body constituting the bone surgical instrument of the second embodiment. [Figure 6B] FIG. 10 is an explanatory view showing a main body constituting the bone surgical instrument of the second embodiment. [Figure 7] FIG. 10 is an explanatory view showing a ratchet forceps constituting the bone surgical instrument of the second embodiment. [Figure 8A] FIG. 10 is a side view showing the bone surgical instrument according to the third embodiment (with the locking mechanism activated). [Figure 8B] FIG. 10 is a side view showing the bone surgical instrument according to the third embodiment (with the locking mechanism released). [Figure 9] FIG. 10 is an explanatory view showing forceps constituting the bone surgical instrument of the third embodiment. [Figure 10A] FIG. 10 is a perspective view showing a sleeve inserted into the body of the bone surgical instrument. [Figure 10B] FIG. 10 is a perspective view showing a sleeve inserted into the body of the bone surgical instrument. [Figure 11] FIG. 10 is a cross-sectional view showing a state in which a sleeve is inserted into the main body of the bone surgical instrument of the second embodiment. [Figure 12] FIG. 1 is a side view showing an example of a conventional bone surgical instrument. [Figure 13] FIG. 10 is a partially cutaway side view showing another example of a conventional bone surgical instrument. DETAILED DESCRIPTION OF THE INVENTION

[0029] First Embodiment Hereinafter, one embodiment of the bone surgical instrument of the present invention will be described. The bone surgery instrument 100 of this embodiment shown in Figures 1 and 2 (Figures 2A and 2B) is used in surgery to insert implants such as screws or pins into bone, and is suitable for use as a drill guide to guide a drill that drills a pilot hole for the implant in the bone, as well as an implant insertion guide, while compressing the tibial tuberosity in the anterior-posterior direction.

[0030] This bone surgical instrument 100 comprises: a hook-shaped support 10 having a support part 11 including a cylindrical portion at its proximal end and a disk-shaped receiving part 12 at its distal end with its center (center of the circle) located on the central axis of the support part 11 (cylindrical portion); a main body 20 which is a cylinder with an outer diameter that can be inserted into the cylindrical portion of the support part 11 and is open at both ends and has a flange 21 at its proximal end with an outer diameter that cannot be inserted into the cylindrical portion of the support part 11; a backflow prevention mechanism 30 which allows movement of the main body part 20 supported by the support part 11 in the distal direction but prevents movement of the main body part 20 in the proximal direction; and a switching means 40 which activates and releases this backflow prevention mechanism 30, so that when the backflow prevention mechanism 30 is released by the switching means 40, the main body part 20 supported by the support part 11 can freely move in both the distal and proximal directions.

[0031] The bone surgical instrument 100 comprises a support 10, a main body 20, a backstop mechanism 30, and a switching means 40.

[0032] The support 10 constituting the bone surgery instrument 100 is hook-shaped and curved in a substantially U-shape or a substantially C-shape, and is arranged so as to surround approximately half the circumference of the bone. The support 10 has a support part 11 including a cylindrical part at its base end (hand side), and a disk-shaped receiving part 12 at its tip end. The center (center of the circle) of the disk-shaped receiving part 12 is located on the central axis of the support part 11 (cylindrical part). The support 10 may be made of stainless steel, titanium alloy, aluminum alloy, high-strength resin, or the like.

[0033] The support part 11 provided on the base end side of the support column 10 has a cylindrical portion, and movably supports the main body part 20 inserted therein. The support part 11 is formed with a window 114 for reading a scale 24 (described later) displayed on the main body part 20.

[0034] The inner diameter of the cylindrical portion of the support portion 11 is preferably 10 to 22 mm, and a suitable example is 16 mm. The outer diameter of the cylindrical portion of the support part 11 is preferably 13 to 25 mm, and a suitable example is 19 mm.

[0035] The main body 20 constituting the bone surgical instrument 100 is a cylindrical body that has an outer diameter that is substantially the same as (strictly speaking, slightly smaller than) the inner diameter of the cylindrical portion of the support part 11 and is longer than the cylindrical portion. This allows the main body 20 to be inserted (slidable) inside the cylindrical portion of the support part 11.

[0036] Both ends (tip and base ends) of the main body 20 are open, and a through-hole 26 is formed inside. An implant such as a drill, screw or pin for drilling a pilot hole is inserted into the through hole 26 from the opening on the base end side of the main body 20 while it is supported by the support part 11, and is guided longitudinally (towards the tip) along the central axis of the main body 20, extending out from the tip opening of the main body 20.

[0037] A flange 21 is provided on the base end side of the main body 20, having an outer diameter that prevents it from being inserted into the cylindrical portion of the support part 11, i.e., an outer diameter that is larger than the inner diameter of the cylindrical portion. The tip surface (annular tip surface) of the flange 21 abuts against the base end surface (annular base end surface) of the cylindrical portion of the support part 11, so that the main body 20 does not fall off the support part 11. The flange 21 provided on the main body 20 has an internal space in the shape of a hexagonal column.

[0038] The main body 20 is inserted into the cylindrical portion of the support portion 11, and is supported so as to be movable (slidable) in the longitudinal direction of the main body 20. The main body 20 inserted into the cylindrical portion of the support portion 11 can move in the longitudinal direction (tip direction) until the tip surface of the flange 21 abuts against the base end surface of the support portion 11 and stops.

[0039] Four pointed ends 22 protruding toward the tip are formed at 90° intervals at the tip of the main body 20. These pointed ends 22 allow for a more stable grip on the bone, suppress vibration of the drill when forming a pilot hole, and prevent the tip from slipping on the anterior surface of the tibia.

[0040] In addition, four slits 23 extending from the tip toward the base end are formed at 90° intervals at the tip of the main body 20, and the position of an implant or the like inserted into the main body 20 can be visually confirmed through these slits 23 using X-rays.

[0041] A scale 24 is marked on the outer peripheral surface of the main body 20 along the longitudinal direction. The operator can grasp the distance between the tip of the main body 20 and the receiving part 12 by reading the scale 24 through the window 114 of the support part 11 .

[0042] The main body 20 may be made of the same material as the support 10 . The inner diameter of the main body 20 is preferably 6 to 18 mm, and a suitable example is 12 mm. The outer diameter of the main body 20 is preferably 10 to 22 mm, and a suitable example is 16 mm.

[0043] The receiving portion 12 provided at the tip side of the support 10 is a circular plate having its center on the central axis of the cylindrical portion of the support portion 11 (the central axis of the main body portion 20 inserted into the cylindrical portion), and is arranged opposite the tip of the main body portion 20 at a distance in the longitudinal direction of the main body portion 20. The base end surface of the receiving portion 12 is a receiving surface 121 that faces the tip of the main body portion 20, and the receiving portion 12 receives the tip of the drill that extends from the tip opening of the main body portion 20 and penetrates the bone at the receiving surface 121. The receiving portion 12 is formed so that a circular region near the center thereof is thinner than the surrounding annular region, and the receiving surface 121 has a recessed shape in the circular region.

[0044] The diameter of the receiving portion 12 is preferably 9 to 19 mm, and a suitable example is 14 mm. The thickness of the receiving portion 12 (annular region) is preferably 1.4 to 7 mm, and a suitable example is 4.2 mm. The thickness of the receiving portion 12 (thin circular region) is preferably 0.5 to 1.2 mm, and a suitable example is 0.8 mm. By making the thickness of the receiving portion 12 (thin circular region) 1.2 mm or less, X-rays can pass through, and this makes it possible to use X-rays to determine where on the receiving surface 121 (circular region) the tip of the implant inserted into the main body portion 20 will reach (or has reached).

[0045] The distance between the tip end surface of the support portion 11 and the receiving surface 121 of the receiving portion 12 is preferably 56 to 81 mm, and a suitable example is 61 mm. The minimum distance between the tip of the main body 20 supported by the support 11 and the receiving surface 121 of the receiving part 12 (the distance when the base end surface of the support 11 and the tip surface of the flange 21 of the main body 20 are in contact) is preferably 20 to 40 mm, and a suitable example is 30 mm.

[0046] The back movement prevention mechanism 30 in the bone surgical instrument 100 is a mechanism that allows the main body 20 supported by the support part 11 to move toward the tip (in the direction of grasping the bone in cooperation with the receiving part 12) and prevents movement toward the base (in the direction of loosening the grip on the bone).

[0047] This backflow prevention mechanism 30 consists of a ratchet mechanism having a plurality of grooves (ratchet teeth having a shape that limits the movement of the main body portion 20 only in the tip direction) 31 arranged in the longitudinal direction of the main body portion 20 on the outer surface (a portion of the circumferential area) of the main body portion 20, a protrusion (ratchet claw) 32 provided on the support portion 11, and a biasing member 33 that biases the protrusion 32 so that the groove 31 and the protrusion 32 fit together.

[0048] When the protrusion 32 biased by the biasing member 33 is fitted into the groove 31 (when the backflow prevention mechanism is in operation), the main body 20 is positioned relative to the support part 11 in the longitudinal direction. When the backflow prevention mechanism is activated, if a force of a certain magnitude or more is applied to the main body 20 in the distal direction, the main body 20 moves in the distal direction while pressing the protrusion 32 against the biasing force of the biasing member 33. However, even if a force of such magnitude is applied to the main body 20 in the proximal direction, the main body 20 cannot move in the proximal direction.

[0049] The switching means 40 in the bone surgical instrument 100 is a means for switching between an activated state of the backflow prevention mechanism 30 and a released state of the backflow prevention mechanism 30.

[0050] The switching means 40 is made up of a switching lever that engages and separates the groove 31 (ratchet teeth) and the protrusion 32 (ratchet pawl). As shown in FIG. 2A, when the switching means 40 (switching lever) is in the first position shown in the same figure, the groove 31 formed in the main body 20 and the protrusion 32 provided on the support part 11 are engaged, and the backflow prevention mechanism 30 (ratchet mechanism) is activated. As shown in FIG. 2B, when the switching means 40 (switching lever) is moved to the second position shown in the same figure, the protrusion 32 moves away from the groove 31 against the biasing force of the biasing member 33, and the reverse movement prevention mechanism 30 enters a released state.

[0051] When the switching means 40 is moved to the second position and the backflow prevention mechanism 30 is released (the groove 31 and the protrusion 32 are not engaged), the main body portion 20 supported by the support portion 11 can move freely in either the tip direction or the base direction.

[0052] According to the bone surgical instrument 100 of this embodiment, when the switching means 40 (switching lever) is placed in the first position and the back movement prevention mechanism 30 (ratchet mechanism) is activated, the back movement prevention mechanism 30 prevents the main body portion 20 supported by the support portion 11 from moving in the proximal direction (movement in the direction that loosens the grip on the bone), so the main body portion 20 and the receiving portion 12 can firmly grip the surface of the bone and maintain a good crimped state. Furthermore, when the switching means 40 (switching lever) is moved to the second position and the back movement prevention mechanism 30 is released, the main body portion 20 can move freely in the proximal direction, so the main body portion 20 can be separated from the surface of the bone without damaging the bone or soft tissue, and the bone surgical instrument 100 can be easily removed.

[0053] Second Embodiment The bone surgical instrument 200 of this embodiment shown in Figures 3 and 4 (Figures 4A and 4B) comprises: a hook-shaped support post 60 having a support part 61 including a cylindrical part 611 at its base end, and a disk-shaped receiving part 62 at its tip end, the center of which is located on the central axis of the cylindrical part 611; a main body part 70 consisting of a cylindrical body having an outer diameter that can be inserted into the cylindrical part 611 and open at both ends, and having a flange 71 at its base end with an outer diameter that cannot be inserted into the cylindrical part 611; The ratchet forceps 80 is provided with a backflow prevention mechanism (locking mechanism 83 of the ratchet forceps 80) that allows movement of the main body 70 supported by the support part 61 in the distal direction but prevents movement of the main body 70 in the proximal direction, and a switching means (switching lever 84 of the ratchet forceps 80) that activates and deactivates the backflow prevention mechanism, and is configured so that when the backflow prevention mechanism is deactivated by the switching means, the main body 70 supported by the support part 61 can move freely in the distal and proximal directions.

[0054] The bone surgical instrument 200 includes a support 60, a main body 70, a backstop mechanism (a locking mechanism 83 of the ratchet forceps 80), and a switching means (a switching lever 84 of the ratchet forceps 80).

[0055] The support 60 constituting the bone surgical instrument 200 is hook-shaped and curved in a substantially U-shape or a substantially C-shape, and is disposed so as to surround approximately half the circumference of the bone. The support 60 has a support part 61 including a cylindrical part at its base end (hand side), and a disk-shaped receiving part 62 at its tip end. The center of the disk-shaped receiving part 62 is located on the central axis of the support part 61 (cylindrical part).

[0056] The support portion 61 provided on the base end side of the support pillar 60 has a cylindrical portion 611 that movably supports the main body portion 70, and a small-diameter cylindrical portion 612 that is formed integrally with this cylindrical portion 611 and has a central axis parallel to the central axis of the cylindrical portion 611. A through hole 613 is formed inside this small diameter cylindrical portion 612 .

[0057] The cylindrical portion 611 of the support portion 61 is formed with a window 614 for reading a scale 74 (described later) displayed on the main body portion 70. As shown in Figure 5, a guide protrusion 615 is formed on the inner surface of the cylindrical portion 611 of the support part 61, and this guide protrusion 615 can be fitted into a guide groove 75 (described later) formed on the outer surface of the main body part 20. The inner and outer diameters of the cylindrical portion 611 are similar to those of the cylindrical portion of the support part 11 constituting the bone surgical instrument 100 of the first embodiment.

[0058] The main body 70 constituting the bone surgical instrument 200 has an outer diameter that is substantially the same as (strictly speaking, slightly smaller than) the inner diameter of the cylindrical portion 611 of the support portion 61, and is made of a cylindrical body that is longer than the cylindrical portion 611. This allows the main body 70 to be inserted (slidable) inside the cylindrical portion 611 of the support portion 61.

[0059] Both ends (the distal end and the proximal end) of the main body 70 are open, and a through-hole 76 is formed inside. An implant such as a drill, screw or pin for drilling a pilot hole is inserted into the through hole 76 from the opening on the base end side of the main body portion 70 supported by the support portion 61, and is guided longitudinally (towards the tip) along the central axis of the main body portion 70, extending out from the tip opening of the main body portion 70.

[0060] The base end of the main body 70 is provided with a flange 71 having an outer diameter that prevents it from being inserted into the cylindrical portion 611 of the support portion 61 , that is, an outer diameter that is larger than the inner diameter of the cylindrical portion 611 . The tip surface (annular tip surface) of the flange 71 abuts against the base end surface (annular base end surface) of the cylindrical portion 611, so that the main body 70 inserted into the cylindrical portion 611 does not fall out. A flange 71 provided on the main body 70 has an internal space in the shape of a hexagonal column.

[0061] The flange 71 of the main body portion 70 is formed with a small diameter through-hole 713 having a central axis parallel to the central axis of the through-hole 76 of the main body portion 70 .

[0062] The main body 70 inserted into the cylindrical portion 611 is supported by the support portion 61 so as to be movable (slidable) in the longitudinal direction of the main body 70. The main body 70 inserted into the cylindrical portion 611 can move in the longitudinal direction (distal direction) until the distal end surface of the flange 71 abuts against the proximal end surface of the support portion 61 and stops.

[0063] Four pointed ends 72 protruding toward the tip are formed at 90° intervals at the tip of the main body 70. These pointed ends 72 allow for a more stable grip on the bone, suppress vibration of the drill when forming a pilot hole, and prevent the tip from slipping on the anterior surface of the tibia.

[0064] Four slits 73 extending from the tip toward the base end are formed at 90° intervals at the tip of the main body 70. Through these slits 73, the position of the implant inserted into the main body 70 can be visually confirmed using X-rays.

[0065] A scale 74 is marked on the outer peripheral surface of the main body 70 along the longitudinal direction. The operator can grasp the distance between the tip of the main body 70 and the receiving part 62 by reading the scale 74 through the window 614 formed in the cylindrical part 611 of the support part 61 .

[0066] As shown in FIG. 6B, a guide groove 75 extending in the longitudinal direction of the main body portion 70 is formed on the outer peripheral surface of the main body portion 70. This guide groove 75 formed on the outer peripheral surface of the main body 70 and the guide protrusion 615 (see Figure 5) formed on the inner peripheral surface of the cylindrical portion 611 of the support portion 61 are configured so that when the two are fitted together, the central axis of the through hole 613 formed in the small diameter cylindrical portion 612 of the support portion 61 coincides with the central axis of the through hole 713 formed in the flange 71.

[0067] By engaging the guide groove 75 with the guide protrusion 615, the main body 70 inserted into the cylindrical portion 611 is prevented from rotating around its central axis, thereby reliably preventing the tip (pointed end 72) of the main body 70 from damaging bones or soft tissues.

[0068] Furthermore, when the guide groove 75 and the guide protrusion 615 are engaged, the central axis of the through hole 613 formed in the support portion 61 (small diameter cylindrical portion 612) and the central axis of the through hole 713 formed in the flange 71 coincide with each other, so that the tip portions (first tip portion 811 and second tip portion 821) of the ratchet forceps 80 described later can be hooked into these through holes 713, 613 to reliably grasp a bone (this operation will also be described later).

[0069] The preferred inner and outer diameters of the main body 70 are similar to those of the main body 20 constituting the bone surgical instrument 100 of the first embodiment.

[0070] The receiving portion 62 provided at the tip side of the support 60 is disk-shaped with its center on the central axis of the cylindrical portion 611 of the support portion 61 (the central axis of the main body portion 70 inserted into the cylindrical portion 611), and is arranged opposite the tip of the main body portion 70 at a distance in the longitudinal direction of the main body portion 70. The configuration of the receiving portion 62 is similar to that of the receiving portion 12 constituting the bone surgical instrument 100 of the first embodiment.

[0071] The preferred distance between the tip surface of the support portion 61 and the receiving surface 621 of the receiving portion 62, and the preferred minimum distance between the tip of the main body portion 70 inserted into the cylindrical portion 611 of the support portion 61 and the receiving surface 621 of the receiving portion 62 are the same as the distances in the bone surgical instrument 100 of the first embodiment.

[0072] The backflow prevention mechanism in the bone surgical instrument 200 is a mechanism that allows the main body 70, which is inserted into the cylindrical portion 611 of the support portion 61, to move toward the tip (in the direction of grasping the bone in cooperation with the receiving portion 62) and prevents movement toward the base (in the direction of loosening the grip on the bone).

[0073] This backflow prevention mechanism comprises a first tip portion 811 that is hooked onto flange 71 by being inserted into through hole 713 formed in flange 71 of main body 70 from the opening on the base end side thereof, and a second tip portion 821 that is hooked onto support portion 61 by being inserted into through hole 613 formed in small diameter cylindrical portion 612 of support portion 61 from the opening on the tip end side thereof, and is comprised of a locking mechanism 83 of ratchet forceps 80 that is equipped with a locking mechanism 83 that limits operation of the handles (operating portions 812, 822) in the direction in which these tip portions 811, 821 open.

[0074] As shown in FIG. 7, a ratchet forceps 80 constituting a bone surgical instrument 200 includes a first swinging member 81 and a second swinging member 82 swingably connected by a hinge pin P1 at their intersection.

[0075] The first swinging member 81 has a first tip portion (grip portion) 811 and a first operating portion (handle) 812, and a switching lever 84 having a protrusion 831 (ratchet pawl) formed thereon is swingably connected to the first swinging member 81 by a hinge pin P2.

[0076] The second swinging member 82 has a second tip portion (grip portion) 821 and a second operating portion (handle) 822, and an escape portion 833 having grooves 832 (ratchet teeth) formed therein is fixed to the second swinging member 82.

[0077] A groove 832 formed in the escape portion 833 and a protrusion 831 formed on the switching lever 84 constitute a locking mechanism 83 that is a reverse movement prevention mechanism.

[0078] The switching lever 84 is a switching means that the ratchet forceps 80 itself has for switching between a state in which the groove 832 and the protrusion 831 are engaged to activate the locking mechanism 83, and a state in which the groove 832 and the protrusion 831 are separated to release the locking mechanism 83.

[0079] As shown in FIG. 4A, when the switching lever 84 of the ratchet forceps 80 is in the first position shown in the same figure, a groove 832 formed in the escape portion 833 and a protrusion 831 formed on the switching lever 84 are fitted together, and the backflow prevention mechanism (locking mechanism 83) is activated.

[0080] When the locking mechanism 83 is in an activated state, the operation of closing the first operating part 812 and the second operating part 822 (the first tip part 811 and the second tip part 821 are closed) is permitted, but the operation of opening the first operating part 812 and the second operating part 822 (the first tip part 811 and the second tip part 821 are opened) is restricted.

[0081] As shown in FIG. 4B, when the switching lever 84 of the ratchet forceps 80 is in the second position shown in the same figure, the protrusion 831 is separated from the groove 832, and the back movement prevention mechanism (lock mechanism 83) is in the released state.

[0082] When the locking mechanism 83 is in the released state, the first operating part 812 and the second operating part 822 can be freely closed (the first tip part 811 and the second tip part 821 are closed) and opened (the first tip part 811 and the second tip part 821 are opened).

[0083] According to the bone surgical instrument 200 of this embodiment, the first tip portion 811 of the ratchet forceps 80 is inserted into and hooked onto the through hole 713 formed in the flange 71 of the main body 70 from the opening on the base end side thereof, and the second tip portion 821 of the ratchet forceps 80 is inserted into and hooked onto the through hole 613 formed in the support part 61 (small diameter cylindrical part 612) from the opening on the tip side thereof, and the first operating part 812 and the second operating part 822 of the ratchet forceps 80 are closed in a state in which the locking mechanism 83 is operated by the switching lever 84 (the groove 832 is engaged with the protrusion 831), thereby causing the first tip portion 811 and the second tip portion 821 to close without moving backward, thereby narrowing the distance between the flange 71 and the support part 61 in the longitudinal direction of the main body 70 and allowing the main body 70 to be moved only in the tip direction.

[0084] In addition, by releasing the locking mechanism 83 using the switching lever 84 (moving the protrusion 831 away from the groove 832), the first tip portion 811 can be removed from the through hole 713, and the second tip portion 821 can be removed from the through hole 613, making it possible to move the main body portion 70 supported by the support portion 61 in either the tip direction or the base direction.

[0085] The bone surgical instrument 200 of this embodiment, which uses the locking mechanism 83 of the ratchet forceps 80 as a backstop mechanism and performs bone grasping operations using the ratchet forceps 80, is easy to operate for the operator (doctor).

[0086] After osteotomy by DTO, arc cutting, and enlargement of the osteotomized portion, the bone surgical instrument 200 of this embodiment can be used to install an implant (hollow screw) according to the following procedures [1] to [9].

[0087] [1] The support 60 (support part 61 and receiving part 62) is placed around the bone with the receiving surface 621 of the receiving part 62 abutting against the posterior part of the tibia.

[0088] [2] The main body 70 is inserted into the cylindrical portion 611 of the support portion 61, and the tip (pointed end 72) of the main body 70 is brought into contact with the anterior surface of the tibia (tuberous surface portion).

[0089] [3] The first tip portion 811 of the ratchet forceps 80 is inserted into the through hole 713 of the flange 71 of the main body 70 from the opening on the base end side thereof, and the first tip portion 811 is hooked onto the flange 71, and the second tip portion 821 of the ratchet forceps 80 is inserted into the through hole 613 of the support portion 61 (small diameter cylindrical portion 612) from the opening on the tip side thereof, and hooked onto the support portion 61, thereby attaching the ratchet forceps 80 by sandwiching the flange 71 and the support portion 61 between the tip portions 811, 821.

[0090] [4] A force is applied in the direction of closing the first operating part 812 and the second operating part 822 of the ratchet forceps 80 (the direction of closing the first tip part 811 and the second tip part 821). As a result, the tibia is firmly grasped in the anterior-posterior direction by the tip (pointed end part 72) of the main body part 70 and the receiving part 62 (receiving surface 621).

[0091] [5] Insert the sleeve (inner cylinder) 90 into the interior (through-hole) of the main body 70. As shown in Figure 10 (Figures 10A and 10B), this sleeve 90 consists of a cylindrical portion 91 having an outer diameter that allows it to be inserted into the inside of the main body portion 70 and a length that is approximately the same as the cylindrical body of the main body portion 70, a knob portion 92 having an outer diameter that prevents it from being inserted into the inside of the main body portion 70, and an engaging portion 93 (shaped like a hexagonal pillar) that is located between the cylindrical portion 91 and the knob portion 92 and engages with the inner shape of the flange 71 of the main body portion 70. The sleeve 90 has a small diameter through hole 94 formed therein.

[0092] FIG. 11 shows a state in which the sleeve 90 is inserted inside the main body 70 supported by the cylindrical portion 611 of the support 61. As shown in the figure, the tip of the sleeve 90 and the tip of the main body 70 are substantially aligned. Since the engagement portion 93 of the sleeve 90 and the flange 71 are engaged, the sleeve 90 does not rotate inside the main body portion 70 . This prevents the sleeve 90 from rotating together with the guide pin when the guide pin is inserted into the tibia while being rotated using the through-hole 94 of the sleeve 90 as a guide.

[0093] [6] A guide pin is inserted into the through-hole 94 of the sleeve 90, and the portion extending from the tip opening of the main body 70 is passed through the tibia until the tip of the guide pin reaches the posterior part of the tibia.

[0094] [7] After removing the sleeve 90 while leaving the guide pin inside the main body 70, insert a hollow drill into the main body 70 along the guide pin, and after its tip reaches the anterior tibia of the bone, use the hollow drill to form a pilot hole toward the posterior tibia.

[0095] [8] Use a hollow driver to install the implant (washer and hollow screw) along the prepared pilot hole. Here, by setting the inner diameter of the main body portion 70 to a large value (for example, 6 to 18 mm), the washer can be placed on the posterior tibia through the inside of the main body portion 70 (through hole 76) together with the hollow screw.

[0096] [9] Remove the guide pin from inside the main body 70, release the locking mechanism 83 of the ratchet forceps 80, remove the first tip 811 of the ratchet forceps 80 from the through hole 713, remove the second tip 821 from the through hole 613, move the main body 70 toward the base end, and remove the main body 70 and the support 60.

[0097] <Third embodiment> The bone surgical instrument 300 of this embodiment shown in Figure 8 (Figures 8A and 8B) comprises a support 60 (support portion 61 and receiving portion 62) and a main body portion 70 similar to those constituting the bone surgical instrument 200 of the second embodiment, and differs from the second embodiment only in the type of forceps having an anti-reverse mechanism and a switching means.

[0098] As shown in FIG. 9, the forceps 85 constituting the bone surgical instrument 300 of this embodiment comprises a first oscillating member 86 and a second oscillating member 87 which are oscillatably connected at their intersection by a hinge pin 89, the first oscillating member 86 having a first tip portion 861 and a first operating portion 862, and the second oscillating member 87 having a second tip portion 871 and a second operating portion 872.

[0099] This forceps 85 is provided with a locking mechanism, which is a backflow prevention mechanism, and a feed screw mechanism 88, which serves as a switching means, to limit the operation of opening the first operating portion 862 and the second operating portion 872 (opening the first tip portion 861 and the second tip portion 871).

[0100] The feed screw mechanism 88 has one end rotatably connected to the second oscillating member 87 by a hinge pin 883, and is equipped with a screw shaft 881 that passes through the first oscillating member 86 and extends to the other end, and a nut 882 that moves while rotating on this screw shaft 881. The position of the nut 882 on the screw shaft 881 determines the maximum angle at which the first operating portion 862 and the second operating portion 872 can be opened (the maximum angle at which the first tip portion 861 and the second tip portion 871 can be opened).

[0101] 8A , by bringing the nut 882 into contact with the first swinging member 86 of the forceps 85 and moving the nut 882 toward one end while closing the first operating part 862 and the second operating part 872, the first tip portion 861 and the second tip portion 871 of the forceps 85 can be closed without reversing. This narrows the distance between the flange 71 and the support part 61 in the longitudinal direction of the main body portion 70, allowing the main body portion 70 to be moved only in the distal direction.

[0102] Furthermore, as shown in FIG. 8B, by moving the nut 882 toward the other end to open the first operating part 862 and the second operating part 872, and removing the first tip part 811 from the through hole 713 and the second tip part 821 from the through hole 613, the locking mechanism (reverse prevention mechanism) is released, and the main body part 70 can be moved in either the tip direction or the base direction.

[0103] Although the embodiments of the present invention have been described above, the present invention is not limited to these and various modifications are possible. For example, in the bone surgical instrument according to the second embodiment, the support portion 61 of the support post 60 may have a bottomed hole that opens at the tip end instead of the through hole 613, and the flange 71 of the main body portion 70 may have a bottomed hole that opens at the base end instead of the through hole 713. [Explanation of symbols]

[0104] 100 Bone surgery instruments 10 posts 11 Support part 114 Window 12 Receiving part 121 Receiving surface 20 Main body 21 flange 22 Point 23 Slit 24 scales 26 Through hole 30 Reverse movement prevention mechanism 31 groove (ratchet teeth) 32 Protrusion (ratchet claw) 33 biasing member 40 Switching means (switching lever) 200 Bone surgery instruments 60 pillars 61 Support part 611 Cylindrical part 612 Small diameter cylindrical part 613 Through hole 614 Window 615 Guide protrusion 62 Receiving part 621 Receiving surface 70 Main body 71 Flange 713 Through hole 72 Point 73 Slit 74 scales 75 Guide groove 76 Through Hole 80 Ratchet Forceps 81 first swing member 811 1st tip 812 1st operation section 82 second swing member 821 2nd tip 822 2nd operation section 83 Locking mechanism (ratchet mechanism) 831 Protrusion (Ratchet Claw) 832 Groove (ratchet teeth) 833 Gangibu 84 Switching lever P1,P2 hinge pins 300 Bone surgery instruments 85 Forceps 86 First swinging member 861 1st tip 862 1st operation section 87 Second swinging member 871 2nd tip 872 2nd operation section 88 Lead screw mechanism 881 Screw shaft 882 Nut 883 Hinge Pin 89 Hinge pin 90 sleeve 91 Cylindrical part 92 Knob 93 Engagement part 94 Through holes

Claims

1. A hook-shaped support having a support portion including a cylindrical portion on a base end side and a plate-shaped receiving portion facing the support portion on a tip end side; a main body portion that is a cylindrical body having an outer diameter that can be inserted into the cylindrical portion of the support portion and has a flange on a base end side that has an outer diameter that cannot be inserted into the cylindrical portion; a back movement prevention mechanism that allows the main body portion supported by the support portion to move in a distal direction and prevents the main body portion from moving in a proximal direction; a switching means for activating and deactivating the reverse movement prevention mechanism, a first end of the main body supported by the support portion and a second end of the main body supported by the support portion; a second end of the main body supported by the support portion; a second end of the main body supported by the support portion;

2. the backflow prevention mechanism comprises a ratchet mechanism having a plurality of grooves arranged in the longitudinal direction of the main body on the outer circumferential surface of the main body, a protrusion provided on the support part, and a biasing member that biases the protrusion so that the groove and the protrusion fit together, 2. The bone surgical instrument according to claim 1, wherein the switching means comprises a switching lever that engages or separates the groove and the protrusion.

3. the backflow prevention mechanism is a locking mechanism of forceps having a first tip end portion hooked onto the flange of the main body portion and a second tip end portion hooked onto the support portion, the locking mechanism limiting handle operation in a direction in which the tip ends open, 2. The bone surgical instrument according to claim 1, wherein the switching means is a means or structure that the forceps has for activating and releasing the locking mechanism.

4. 4. The bone surgical instrument according to claim 3, wherein the flange and the support portion of the main body are formed with through holes or bottomed holes for receiving the first tip end and the second tip end of the forceps, respectively.

5. A guide groove extending in a longitudinal direction is formed on one of an outer peripheral surface of the main body portion and an inner peripheral surface of the support portion, a guide protrusion that can be fitted into the guide groove is formed on the other of the outer peripheral surface of the main body portion and the inner peripheral surface of the support portion, 5. The bone surgical instrument according to claim 4, wherein when the guide groove and the guide protrusion are fitted together, the central axes of the through hole or the bottomed hole are aligned.

6. 6. A bone surgery instrument according to claim 3, wherein the forceps are ratchet forceps.

7. 6. The bone surgery instrument according to claim 3, wherein the forceps is provided with a feed screw mechanism as the locking mechanism, which can limit the opening operation of the handle.

8. A hook-shaped support having a support portion including a cylindrical portion on a base end side and a disk-shaped receiving portion having a center on the central axis of the cylindrical portion on a tip end side; a main body portion that is made of a cylindrical body having an outer diameter that can be inserted into the cylindrical portion of the support portion and has a flange on a base end side that has an outer diameter that cannot be inserted into the cylindrical portion, a through hole or a bottomed hole formed in the flange and the support portion of the main body, into which the tip end of a pair of forceps that opens and closes can be attached, respectively;

Images