Bone surgical instrument

Abstract

An object of the present invention is to provide a bone surgical instrument that can perform arcuate osteotomy correctly and simply and has high versatility. The bone surgical instrument (1) includes: a central portion (2) positioned at a specific point of the bone; a guiding portion (3) having a slit (4) extending in the circumferential direction around an axis (I) passing through the central portion (2), the slit (4) penetrating the guiding portion (3) in a direction parallel to the axis (I), and the guiding portion guiding an osteotome inserted into the slit (4) in the circumferential direction around the axis (I); and a fixing portion (6) fixed to the bone using a fixing member.

Description

Technical Field

[0001] The present invention relates to an instrument for bone surgery, and particularly to an instrument used as a guide for guiding an osteotome in osteotomy. Background Art

[0002] Currently, as a treatment method for medial knee joint pain, medial open high tibial osteotomy (HTO) and medial open subtrochanteric osteotomy (DTO) for correcting the linearity of the knee are known. As Figure 7 shown, in HTO, osteotomy is performed on the proximal side of the trochanter B, and in DTO, osteotomy is performed on the distal side of the trochanter B.

[0003] In HTO, the deformative knee osteoarthritis (OA) of the patellofemoral joint (PF) caused by the lowering of the position of the patella C becomes a problem. Different from HTO, in DTO, the position of the patella C does not change before and after the surgery. Therefore, compared with HTO, DTO has the advantage that the PFOA caused by the lowering of the position of the patella C is less likely to deteriorate after the surgery. On the other hand, the postoperative bone instability caused by the patellar tendon D stretching the bone end of the tibia A and the accompanying delay in bone healing become the problems of DTO.

[0004] As another method of osteotomy of the tibia, a method of osteotomizing the tibia in an arc shape has been proposed (for example, refer to Non-Patent Document 1). By the arc-shaped osteotomy, the contact area of the osteotomy site is increased, and thus acceleration of bone healing can be expected.

[0005] Furthermore, as another method of osteotomy of the tibia, Distal Tibia Tuberosity Arc Osteotomy (DTAO) of osteotomizing the distal part of the trochanter in an arc shape has been proposed. Different from the method of Non-Patent Document 1 in which the tibia is separated and disconnected at a position more distal than the trochanter, in DTAO, the distal part of the trochanter is osteotomized in the anteroposterior direction until midway to maintain the continuity between the bone end and the bone shaft of the tibia.

[0006] Prior Art Documents

[0007] Non-Patent Documents

[0008] Non-Patent Document 1: Kenichi Tajitani and three others, "Usefulness of Citieffe arch chisel in high tibial osteotomy for bone healing", Journal of the China-Shikoku Orthopaedic Society, China-Shikoku Orthopaedic Society, April 15, 2000, Vol. 12, No. 1, p. 111-116 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] As one of the problems of the method of Non-Patent Document 1, it can be cited that the osteotomy operation is very complicated. In Non-Patent Document 1, while hitting a bow chisel with a hammer, the tibia is osteotomized in an arc shape with the bow chisel. In this method, when osteotomizing the vicinity of the trochanter in an arc shape in DTAO, since the cortical bone under the trochanter is hard, it is difficult to correctly osteotomize the trochanter along the arc-shaped line, and it is difficult to maintain the continuity of the bone due to the load generated by hitting the bow chisel on the bone. When unevenness occurs on the osteotomy surface of the trochanter, the contact area becomes smaller, or an uneven load is applied to the bone due to forcing the osteotomy surface to contact the adjacent bone surface, which may increase the instability of the bone.

[0011] The present invention has been completed in view of the above circumstances, and an object thereof is to provide a bone surgical instrument that can correctly and simply perform arc-shaped osteotomy and has high versatility.

[0012] Means for Solving the Problem

[0013] In order to achieve the above object, the present invention provides the following means.

[0014] One aspect of the present invention is a bone surgical instrument that guides an osteotome in the circumferential direction around a specific point of a bone, and includes: a central portion positioned at the specific point; a guiding portion having a slit extending in the circumferential direction around an axis passing through the central portion, the slit penetrating the guiding portion in a direction parallel to the axis, and the guiding portion guiding the osteotome inserted into the slit in the circumferential direction around the axis; and a fixing portion fixed to the bone using a fixing member.

[0015] According to this aspect, the central portion is positioned at a specific point of the bone, the guiding portion is arranged on the bone so that the slit is located at the position where osteotomy should be performed, and the fixing portion is fixed to the bone using a fixing member so that the bone surgical instrument does not move relative to the bone. In this state, the slit extends in the circumferential direction around the specific point. Therefore, while moving the osteotome along the guidance of the slit and performing osteotomy with the osteotome, arc-shaped or substantially arc-shaped osteotomy can be correctly and simply performed.

[0016] Moreover, since the bone surgical instrument can be combined with various osteotomes thinner than the width of the slit, a bone surgical instrument with high versatility can be provided.

[0017] In the above aspect, the bone surgical instrument may also be used to osteotomize the distal end portion of the trochanter of the tibia in an arc shape or a substantially arc shape.

[0018] That is, by positioning the central portion at the articulation point of the bone end of the tibia, the distal end of the trochanter can be correctly and simply osteotomized along an arc-shaped or substantially arc-shaped line centered on the articulation point.

[0019] In the above-described manner, the guiding portion may also have a thickness such that the protruding amount of the tip of the osteotome from the slit is equal to or less than a predetermined amount.

[0020] The protruding amount of the tip of the osteotome from the slit is limited by the thickness of the guiding portion. According to the above structure, since the protruding amount of the tip from the slit is limited to a predetermined amount or less, over-osteotomy in the direction parallel to the axis can be prevented.

[0021] In the above-described manner, the central portion may also have a pin hole that penetrates the central portion in the direction parallel to the axis.

[0022] In osteotomy, a pin serving as a reference for position and direction is sometimes inserted at a specific point of the bone. The central portion is positioned at the specific point by the pin passing through the pin hole, and the depth direction of the slit is parallel to the long axis direction of the pin. Therefore, an osteotomy surface parallel to the long axis of the pin can be formed.

[0023] In the above-described manner, the fixing portion may also be provided on the opposite side of the central portion with respect to the guiding portion.

[0024] According to this structure, when osteotomy is performed along a plane intersecting the axis passing through the central portion with the bone surgical instrument disposed on the bone, interference between the cutting instrument and the fixing member can be prevented.

[0025] In the above-described manner, the width of the slit may also be 0.5 mm to 1.5 mm larger than the thickness of the osteotome.

[0026] According to this structure, when the osteotome is inserted into the slit, a proper space margin is formed inside the slit. Thereby, the vibration of the osteotome during cutting can be reduced, and interference between the osteotome and the inner surface of the slit can be prevented.

[0027] In the above-described manner, it may also be that, when viewed from above in the direction along the axis, the outer shape of the guiding portion is similar or substantially similar to the shape of the slit, and the wall thickness of the edge portion of the guiding portion surrounding the slit is 1 mm to 5 mm.

[0028] According to this structure, under X-ray fluoroscopy, the position of the slit can be correctly grasped based on the image of the guiding portion. Therefore, in osteotomy along a plane intersecting the axis passing through the central portion until the position of the slit, over-osteotomy beyond the position of the slit can be prevented.

[0029] In the above-described manner, a contact surface that contacts the surface of the bone may also be provided on one side in the direction along the above-described axis, and the contact surface is a concave surface that conforms to the shape of the surface of the bone.

[0030] The surface of the bone on which the bone surgical instrument is disposed is a convex curved surface. According to the above structure, the bone surgical instrument is disposed on the bone in such a manner that the concave surface contacts the surface of the bone, so that the bone surgical instrument can be positioned more stably with respect to the bone, and the vibration of the bone surgical instrument during osteotomy can be reduced.

[0031] In the above-described manner, a support column portion that connects the central portion and the guide portion to each other may also be provided, and the support column portion extends in a direction that intersects the above-described axis between the central portion and the circumferential center of the guide portion.

[0032] According to this structure, when viewed from above in the direction along the axis passing through the central portion, the bone surgical instrument has a substantially T-shaped configuration that is symmetric with respect to the support column portion. With such a configuration, it is possible to prevent the bone surgical instrument disposed on the bone from tilting, and the bone surgical instrument can be disposed more stably with respect to the bone.

[0033] In the above-described manner, the slit may also extend along an arc having a constant radius of curvature.

[0034] After osteotomy is performed along the guidance of the arc-shaped slit, a gap corresponding to the thickness of the osteotome is formed along the arc-shaped osteotomy line. According to the above structure, the distance between a specific point and the osteotomy line is the same throughout the entire length of the osteotomy line. Therefore, it is possible to maintain the width of the gap constant while rotating the bone fragment including the specific point around the specific point. That is, the two bone surfaces facing each other with the gap therebetween do not interfere with each other during rotation, and the bone fragment can be easily rotated.

[0035] In the above-described manner, the slit may also extend along a curve whose radius of curvature gradually decreases in the circumferential direction around the above-described axis.

[0036] According to this structure, since the distance between the central portion and the slit gradually decreases in the circumferential direction from one end of the slit to the other end, the distance between the specific point and the osteotomy line also gradually decreases from one end of the osteotomy line to the other end. Therefore, as the bone fragment including the specific point is rotated around the specific point, the gap gradually narrows. Thus, after the bone is corrected by using the rotation of the bone fragment, the compression and deformation of the bone required to bring the two bone surfaces facing each other with the gap therebetween into contact with each other can be reduced.

[0037] In the above-described manner, the slit may also be composed of a plurality of straight portions that are continuous with each other in the circumferential direction around the above-described axis, and the plurality of straight portions extend along the tangent direction or substantially tangent direction of a circle centered on the above-described axis.

[0038] According to this structure, even an osteotome of the type that can move on a parallel plane can be easily guided by the slit.

[0039] In the above manner, it may also be that the triangle with the two ends of each of the above straight portions and the above central portion as vertices is a right triangle with the above straight portion as the base, and the opposite side of one right triangle and the hypotenuse of another right triangle adjacent to this one right triangle are shared.

[0040] According to this structure, by using a plurality of right triangles continuously arranged in the circumferential direction around the central portion, it is possible to easily design the shape of a slit composed of a plurality of straight portions and having a gradually decreasing radius of curvature.

[0041] In the above manner, it may also be that when the central portion is displaced by a predetermined angle in the circumferential direction around the above axis, the distance between the central portion and the slit is shortened by a predetermined length.

[0042] According to this structure, when a bone fragment including a specific point is rotated by a predetermined angle, the gap becomes narrower by a predetermined length each time. Therefore, by designing the predetermined angle and the predetermined length according to the thickness of the osteotome and the correction angle of the bone fragment including the specific point, it can be easily designed that the width of the gap after rotation becomes a desired size.

[0043] In the above manner, the distance between the central portion and the slit may also be 45 mm to 65 mm.

[0044] According to this structure, in the osteotomy at the distal end of the trochanter, it is possible to prevent the arc-shaped or substantially arc-shaped osteotomy line from interfering with the patellar tendon. And it is possible to ensure a sufficient width for the osteotomy portion of the trochanter located on the more proximal side than the osteotomy line, and it is possible to easily insert a bone screw for fixing the osteotomy portion into the osteotomy portion.

[0045] In the above manner, it may also include a movable portion connected to the above guiding portion in a manner that can move in the circumferential direction around the above axis. The movable portion has a guiding hole that penetrates in a direction parallel to the radial direction orthogonal to the above axis, guides a guide wire or a guiding sleeve for inserting the guide wire toward the above axis, and the outer peripheral surface of the guide wire passing through the guiding hole is disposed at a position away from the above axis in an offset direction orthogonal to the above axis and the central axis of the guiding hole.

[0046] In the above manner, the movable portion may also include a second guiding portion for guiding the osteotome along a plane orthogonal to the above axis.

[0047] The effects of the invention are as follows.

[0048] According to the present invention, there is an effect of being able to provide a bone surgical instrument that can perform arc-shaped osteotomy correctly and simply and has high versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1A is a top view of an instrument for bone surgery according to an embodiment of the present invention.

[0050] Figure 1B is Figure 1A a side view of the instrument for bone surgery.

[0051] Figure 2 is a diagram for explaining the operation sequence of DTAO of the instrument for bone surgery using Figure 1A and Figure 1B .

[0052] Figure 3 is a diagram for explaining the operation sequence of DTAO of the instrument for bone surgery using Figure 1A and Figure 1B .

[0053] Figure 4 is a diagram for explaining the operation sequence of DTAO of the instrument for bone surgery using Figure 1A and Figure 1B .

[0054] Figure 5 is a perspective view of a modified example of the instrument for bone surgery in FIG. 1.

[0055] Figure 6 is a top view of another modified example of the instrument for bone surgery in FIG. 1.

[0056] Figure 7 is a diagram for explaining HTO and DTO.

[0057] Figure 8A is a top view of an instrument for bone surgery according to another embodiment of the present invention.

[0058] Figure 8B is a side view of the instrument for bone surgery Figure 8A viewed in the direction along the central axis of the guide hole.

[0059] Figure 8C is a perspective view showing an example of a connection structure connecting a movable part and a guide part Figure 8A of the instrument for bone surgery.

[0060] Figure 9A is a top view of an instrument for bone surgery according to another embodiment of the present invention.

[0061] Figure 9B is Figure 9A a perspective view of an example of a second part of the movable part in the instrument for bone surgery.

[0062] Figure 9C isFigure 9A Another perspective view of a second part of a movable part in an orthopedic surgical instrument.

[0063] Figure 9D is Figure 9A Another perspective view of a second part of a movable part in an orthopedic surgical instrument.

[0064] Figure 10 A side view showing a state in which a guide sleeve and a guide wire are inserted into a guide hole in the second part. DETAILED DESCRIPTION

[0065] Hereinafter, an orthopedic surgical instrument according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0066] The orthopedic surgical instrument 1 of the present embodiment is used for osteotomy along an arc-shaped or substantially arc-shaped line extending in the circumferential direction of a specific point on the radius bone. In the present embodiment, as an example of osteotomy, DTAO (Distal Tibia Tuberosity Arc Osteotomy) for osteotomizing the tuberosity B of the tibia A substantially in an L shape will be described. The orthopedic surgical instrument 1 is not limited to DTAO and can also be applied to any other osteotomy.

[0067] As Figure 4 shown, DTAO osteotomizes the distal end portion of the tuberosity B along an arc-shaped or substantially arc-shaped line centered on the open hinge point H, and in this regard, it is different from the medial open HTO and DTO. Figure 4 Shows the corrected state generated by rotating the bone end portion A1 and the osteotomized portion of the tuberosity B together around the hinge point H.

[0068] In DTAO, the rear of the tuberosity B is osteotomized parallel to the tibia axis, and the distal end portion of the tuberosity B is osteotomized perpendicular to the tibia axis. Thus, as the osteotomy surface, the lower surface E (see Figure 3 .) of the rear of the tuberosity B and the side surface F of the distal end portion of the tuberosity B are formed. Here, the osteotomy of the distal end portion of the tuberosity B is performed along an arc-shaped or substantially arc-shaped line centered on the hinge point H, and the side surface F becomes a convex surface curved around an axis passing through the hinge point H in the front-rear direction of the tibia A.

[0069] Next, the tibia A is osteotomized from the medial side of the tibia A toward the hinge point H to form an osteotomy line L.

[0070] In the accompanying drawings for reference, the right side of the tibia A is the medial side, the left side of the tibia A is the lateral side, and the direction perpendicular to the paper surface is the front-rear direction.

[0071] Next, the osteotomy part of the bone end part A1 and the trochanter part B is rotated around the hinge point H by the correction angle θ, and the osteotomy line L is opened to correct the deformation of the tibia A. At this time, the side surface F slides along the concave surface G of the bone shaft part A2.

[0072] Next, artificial bone or autologous bone is transplanted into the opening part.

[0073] Next, while applying pressure to the osteotomy part of the trochanter part B so that the lower surface E and the side surface F are in contact with the adjacent bone surface, the osteotomy part of the trochanter part B is fixed to the rear bone A2 with bone screws or the like.

[0074] In this way, in the case of DTAO, the osteotomy part of the trochanter part B is in contact with the adjacent bone surface at the lower surface E and the side surface F, and compared with HTO and DTO, the number and contact area of the contact surfaces of the osteotomy part are increased. Therefore, DTAO is excellent in terms of improving the stability of the bone, enabling early bone healing of the osteotomy part, and improving the fixation strength.

[0075] The bone surgical instrument 1 is a guiding device that guides an osteotome used to form the side surface F along an arc-shaped or substantially arc-shaped line. As Figure 1A and Figure 1B shown, the bone surgical instrument 1 includes a central part 2, a guiding part 3 having a slit 4, a support part 5 that connects the central part 2 and the guiding part 3 to each other, and a fixing part 6 that is fixed to the tibia A using a fixing member.

[0076] Figure 1A is a top view of the bone surgical instrument 1 observed in the direction along a predetermined axis I passing through the central part 2, Figure 1B is observed from the right side Figure 1A of the bone surgical instrument 1 side view.

[0077] The central part 2, the guiding part 3, the support part 5, and the fixing part 6 are all formed integrally, and thus, the bone surgical instrument 1 is composed of a single component.

[0078] Considering the wear of the cutting instrument, the bone surgical instrument 1 is preferably formed of stainless steel, titanium, or a titanium alloy.

[0079] The central part 2 is a part positioned at the hinge point (specific point) H of the tibia A, and has a pin hole 2a that penetrates the central part 2 in a direction parallel to the axis I. As Figure 2 and Figure 3 shown, in DTAO, the hinge pin P1 is inserted at the hinge point H and along the anteroposterior direction of the tibia A. The pin hole 2a is coaxial or substantially coaxial with the axis I, and has an inner diameter slightly larger than the outer diameter of the hinge pin P1. By passing the hinge pin P1 through the pin hole 2a, the central part 2 can be positioned at the hinge point H in such a manner that the axis I coincides or substantially coincides with the long axis of the hinge pin P1.

[0080] The guiding portion 3 is arc-shaped, extends circumferentially around the axis I, and has a constant radius of curvature throughout its entire length. The slit 4 is arc-shaped, extends circumferentially around the axis I, and has a constant radius of curvature throughout its entire length. Therefore, when viewed from above in the direction along the axis I, the outer shape of the guiding portion 3 is similar or substantially similar to the shape of the slit 4.

[0081] The slit 4 penetrates the guiding portion 3 in a direction parallel to the axis I. The thickness t of the guiding portion 3 in the direction parallel to the axis I, that is, the depth of the slit 4, is smaller than the length of the osteotome, and the tip of the osteotome penetrating the slit 4 protrudes from the slit 4.

[0082] The wall thickness d of the edge portion of the guiding portion 3 surrounding the slit 4 is substantially uniform throughout the entire circumference. From the viewpoints of the slender structure of the guiding portion 3 and the visibility of the guiding portion 3 in the X-ray fluoroscopic image formed thereby, the wall thickness d is preferably 1 mm to 5 mm.

[0083] The distance r between the central portion 2 in the radial direction orthogonal to the axis I and the slit 4, that is, the radius of curvature of the slit 4, is preferably 45 mm to 65 mm. The distance r corresponds to the distance between the hinge point H and the side surface F. By setting the distance r within the above range, it is possible to prevent the osteotomy line of the side surface F from interfering with the patellar tendon D. Also, it is possible to ensure a sufficient width for the osteotomy portion of the trochanteric portion B located closer to the distal end side than the side surface F, and after correction, it is possible to insert a bone screw for fixing the osteotomy portion into the osteotomy portion. When the distance r is larger than 65 mm, the osteotomy line of the side surface F approaches the diaphysis and the cortical bone becomes larger, making osteotomy difficult.

[0084] The distance from the hinge point H to the distal end portion of the trochanteric portion B where the side surface F should be formed varies among individuals. Therefore, it is preferable to prepare a plurality of bone surgical instruments 1 having different distances r so that an appropriate-sized bone surgical instrument 1 can be selected for each patient.

[0085] The strut portion 5 extends linearly in the radial direction orthogonal to the axis I between the central portion 2 and the circumferential center of the guiding portion 3. Therefore, when viewed from above in the direction along the axis I, the bone surgical instrument 1 has a substantially T-shaped configuration that is symmetric with respect to the strut portion 5.

[0086] The fixing portion 6 has a fixing hole 6a that penetrates the fixing portion 6 in a direction parallel to the axis I. In a state where the central portion 2 is positioned at the hinge point H by the hinge pin P1, the fixing pin P2 is inserted into the tibia A through the fixing hole 6a, so that the bone surgical instrument 1 can be fixed to the tibia A without moving in the direction orthogonal to the axis I. The fixing portion 6 is located on the opposite side of the central portion 2 with respect to the guiding portion 3, and in the case of the Figure 1A bone surgical instrument 1, the fixing portion 6 is located on the extension line of the strut portion 5.

[0087] One or more fixing holes 5a identical to the fixing hole 6a may also be provided in the support portion 5 so that the surgical staff can change or select the fixing position of the bone surgical instrument 1 using the fixing pin P2. In Figure 1A this example, the support portion 5 has seven fixing holes 5a arranged at intervals in the length direction of the support portion 5. When the plurality of fixing holes 5a are arranged at equal intervals, the plurality of fixing holes 5a can be used as scales. That is, after positioning the central portion 2 at the hinge point H and arranging the bone surgical instrument 1 on the tibia A, based on the positional relationship between the distal end portion of the trochanter B and the plurality of fixing holes 5a, a bone surgical instrument 1 of a smaller appropriate size can be selected.

[0088] The sizes of the guide portion 3 and the slit 4 are designed according to the size of the osteotome used to form the side surface F. The osteotome is a general osteotome such as a thin saw blade.

[0089] Specifically, the thickness t of the guide portion 3 is designed according to the length of the osteotome so that the protruding amount of the front end of the osteotome protruding from the slit 4 is below a predetermined amount. For example, the thickness t is preferably 5 mm to 25 mm smaller than the length of the osteotome.

[0090] Moreover, in order to prevent the osteotome from shaking in the slit 4, the width w of the slit 4 in the radial direction orthogonal to the axis I is preferably 0.5 mm to 1.5 mm larger than the thickness of the osteotome.

[0091] In a preferred example, the thickness of the osteotome is 0.3 mm to 0.8 mm, the width is 5 mm to 15 mm, and the length is about 15 mm to 45 mm. When the thickness and width of the osteotome are too large, the amount of bone cutting becomes more. As a result, in order to bring the osteotomy surface into contact with the adjacent bone surface, a larger pressing force is required, and the load applied to the bone becomes larger. Moreover, when the width of the osteotome is too large, it is difficult to perform osteotomy for a complex shape. When the length of the osteotome is too large, the osteotome is likely to bend due to the load during bone cutting, and when the length of the osteotome is too small, the bone cannot be cut to a sufficient depth.

[0092] Considering the above-mentioned size of the osteotome, in order to ensure the guiding property of the guide portion 3 for the osteotome and the amount of bone cutting, the thickness t of the guide portion 3 is preferably 10 mm to 25 mm. Moreover, the width w of the slit 4 is preferably 1 mm to 2 mm.

[0093] Figure 1A and Figure 1B the bone surgical instrument 1 of

[0094] Next, an example of DTAO using the bone surgical instrument 1 will be described.

[0095] First, as Figure 2 shown, as preparation for osteotomy, the guide wire GW and the hinge pin P1 are inserted into the tibia A. Specifically, the guide wire GW is inserted into the tibia A from the medial side toward the hinge point H. The hinge point H is set near the outer edge of the tibia A. Two guide wires GW arranged in the anterior-posterior direction of the tibia A may be inserted into the tibia A in parallel. Next, the hinge pin P1 is inserted into the hinge point H in the anterior-posterior direction of the tibia A.

[0096] Next, as Figure 3 shown, the bone surgical instrument 1 is arranged on the tibia A. Specifically, by passing the hinge pin P1 through the pin hole 2a, the central portion 2 is positioned at the hinge point H, and it is confirmed that the slit 4 is located at the distal end of the trochanter B. When the slit 4 is not located at the distal end of the trochanter B, the size of the bone surgical instrument 1 is changed so that the slit 4 is located at the distal end of the trochanter B. Then, the fixing portion 6 is fixed to the tibia A by inserting the fixing pin P2 into the tibia A in the anterior-posterior direction through the fixing hole 6a.

[0097] Next, a bone saw is inserted into the tibia A from the medial side, and osteotomy is performed on the posterior side of the trochanter B parallel to the tibial axis. In Figure 3 , the region between the shaded guide wire GW and the guiding portion 3 is the osteotomized region. Thus, as the first osteotomy surface, the lower surface E is formed between the guide wire GW and the guiding portion 3. At this time, an electric or pneumatic bone saw may also be used.

[0098] While observing the guide wire GW, the bone surgical instrument 1, and the bone saw in the X-ray fluoroscopic image of the tibia A in the anterior-posterior direction, the osteotomy of the lower surface E is performed. That is, the surgeon can perform osteotomy using the guide wire GW and the guiding portion 3 as markers for the boundary of the range to be osteotomized. In particular, since the outer shape of the guiding portion 3 is similar or substantially similar to that of the slit 4, the surgeon can correctly grasp the position of the slit 4 from the outer shape of the guiding portion 3. Therefore, it is possible to prevent over-osteotomy beyond the later-formed side surface F.

[0099] Moreover, the fixing portion 6 is located on the opposite side of the central portion 2 with respect to the guiding portion 3. Therefore, when osteotomy is performed on the posterior side of the trochanter B, it is possible to prevent the bone saw from interfering with the fixing pin P2 passing through the fixing hole 6a.

[0100] Next, using the bone surgical instrument 1, osteotomy is performed on the distal end of the trochanter B in the anteroposterior direction. That is, the osteotome is inserted into the slit 4, and while moving the osteotome circumferentially within the slit 4, osteotomy of the trochanter B is performed. As a result, as the second osteotomy surface, a side surface F is formed at the distal end of the trochanter B. The side surface F is a convex surface that is curved in an arc shape around the long axis of the hinge pin P1. A gap with a width corresponding to the thickness of the osteotome is formed between the side surface F of the trochanter B and the concave surface G of the bone end portion A1.

[0101] Next, the tibia A is osteotomized from the inside toward the outside along the guide wire GW. As a result, a third osteotomy surface is formed along the osteotomy line L.

[0102] Next, as Figure 4 shown, the bone surgical instrument 1 is removed from the tibia A, and the osteotomized portion of the bone end portion A1 and the trochanter B is rotated by an angle θ around the hinge point H with respect to the diaphysis A2. As a result, the alignment of the tibia A is corrected, and the load applied to the tibia A is transferred from the inside to the outside.

[0103] Since the slit 4 has a constant radius of curvature, the side surface F and the concave surface G are curved surfaces with a constant radius of curvature centered on the hinge point H, respectively. Therefore, regardless of the rotation angle of the osteotomized portion around the hinge point H, the width of the gap is maintained constant. That is, the side surface F always slides along the concave surface G while maintaining a constant distance from the concave surface G, preventing interference between the side surface F and the concave surface G. As a result, the osteotomized portion can be easily rotated around the hinge point H.

[0104] Next, artificial bone or autologous bone is transplanted into the open portion in the osteotomy line L.

[0105] Next, while applying compression to the osteotomized portion in the anteroposterior direction and the direction of the tibia axis so that the lower surface E and the side surface F are in contact with the adjacent bone surfaces, the osteotomized portion is fixed to the posterior bone with bone screws or the like.

[0106] Thus, according to the present embodiment, in the osteotomy of the distal end of the trochanter B, the osteotome is guided by the arc-shaped slit 4 whose center is located at the hinge point H. Therefore, the trochanter B can be accurately and simply osteotomized in an arc shape centered on the hinge point H.

[0107] Moreover, the bone surgical instrument 1 can be combined with various osteotomes having a thickness smaller than the width w of the slit 4, and a bone surgical instrument 1 with high versatility can be provided.

[0108] As a method of performing osteotomy in an arc shape, there is a method of using an arc-shaped chisel or a method of using an electric bone saw that is movable in an arc shape. However, in the case of using a chisel, an impact generated by hitting the chisel with a hammer is applied to the tibia A, and it is sometimes difficult to maintain the continuity between the bone end portion A1 and the bone shaft portion A2. In the case of using an electric bone saw, it is difficult to align the rotation center of the bone saw with the hinge point H.

[0109] In contrast, according to the present embodiment, an excessive load is not applied to the tibia A, and osteotomy can be performed in a state where the central portion 2, which is the rotation center of the osteotomy knife, is aligned with the hinge point H.

[0110] In the present embodiment, the contact surface of the bone surgical instrument 1 that contacts the surface of the tibia A can be a flat surface as shown in Figure 1B However, it can also be a concave surface (contact surface) 7 that matches the shape of the surface of the tibia A as shown in Figure 5 . In the bone surgical instrument 10 shown in Figure 5 , a fixing portion 6 is provided at the connecting portion between the guiding portion 3 and the support portion 5.

[0111] The concave surface 7 is formed on the end surface of the bone surgical instrument 10 on one side in the direction along the axis I, for example, on the end surface of the guiding portion 3. The front surface of the tibia A on which the bone surgical instrument 10 is disposed is a convex curved surface. By disposing the bone surgical instrument 10 on the tibia A with the concave surface 7 along the surface of the tibia A, the position and posture of the bone surgical instrument 10 relative to the tibia A can be made more stable, and the vibration of the bone surgical instrument 10 during osteotomy can be reduced.

[0112] In the present embodiment, the slit 4 is provided to extend along an arc having a constant radius of curvature. However, alternatively, the slit 4 may extend along a curve in which the radius of curvature, that is, the distance r, gradually decreases from one end to the other end.

[0113] And, in the present embodiment, the slit 4 is provided to be smoothly curved throughout its entire length. However, alternatively, as shown in Figure 5 and Figure 6 , it is composed of a plurality of straight portions 4a that are circumferentially continuous and extend along the tangential direction or substantially tangential direction of a circle centered on the axis I.

[0114] In the Figure 6 bone surgical instrument 20, the slit 4 is composed of a plurality of straight portions 4a, and the distance r between the central portion 2 and the slit 4 gradually shortens from one end to the other end of the slit 4. In the case of the bone surgical instrument 20 for DTAO, one end of the slit 4 is disposed on the outside of the tibia A, and the other end of the slit 4 is disposed on the inside of the tibia A.

[0115] As shown in Figure 6As shown, the triangle with the two ends of each straight portion 4a and the central portion 2 as vertices can also be a right triangle with the straight portion 4a as the base. Each right triangle has a hypotenuse, a base sandwiching the right angle, and an opposite side. The hypotenuse and the opposite side extend radially from the axis I. The opposite side of one right triangle and the hypotenuse of another right triangle adjacent to one right triangle are shared and have the same length. Therefore, the slit 4 is formed by the bases of a plurality of right triangles continuously arranged around the axis I. In each right triangle, the length L1 of the opposite side is smaller than the length L2 of the hypotenuse. Therefore Figure 6 in Figure 6 , the length of the side of the right triangle, that is, the distance r, gradually becomes shorter from the left side to the right side.

[0116] If an osteotome is guided along such a slit 4, osteotomy surfaces F and G are formed whose distances from the hinge point H gradually decrease from the outside to the inside of the tibia A. Therefore, during correction, as the osteotomy part rotates inward, the gap between the side surface F and the concave surface G becomes narrower. That is, since there is a sufficient width of the gap between the side surface F and the concave surface G at the initial stage of rotation, the osteotomy part can rotate without interfering with the concave surface G. Further, since the gap becomes narrower at the end of rotation, less compression and deformation of the osteotomy part required for the side surface F to contact the concave surface G are sufficient, and the burden on the tibia A can be reduced.

[0117] Moreover, when the apex angles α of the central portions 2 of the plurality of right triangles are equal to each other, the width of the gap after correction becomes uniform over the entire length. Therefore, the side surface F and the concave surface G can be uniformly contacted by pressing in the direction along the tibia axis, and local concentration of load on the tibia A after correction can be prevented.

[0118] Moreover, since the slit 4 is formed by the straight portions 4a, when an osteotome that moves on a parallel plane is used, interference between the osteotome and the inner surface of the slit 4 can be prevented.

[0119] In another example of the slit 4 where the distance r gradually becomes shorter in the circumferential direction, the slit 4 can also be designed such that when it is displaced by a predetermined angle θ' in the circumferential direction around the axis I, the distance r between the central portion 2 and the slit 4 is shortened by a predetermined length Δr.

[0120] In this case, when the osteotomy part is rotated by a predetermined angle θ' around the hinge point H, the width of the gap is narrowed by the length Δr. Therefore, when the predetermined angle θ' is equal to the correction angle θ and the length Δr is equal to the width of the gap between the side surface F and the concave surface G generated by osteotomy, after the osteotomy part is rotated by the correction angle θ, the side surface F and the concave surface G come into contact with each other and the gap disappears. That is, after correction, the side surface F and the concave surface G can be contacted without imposing a burden on the tibia A.

[0121] In the above-described embodiment, the support portion 5 is provided to connect the central portion 2 and the center of the guide portion 3 to each other. Alternatively, however, the central portion 2 and other positions of the guide portion 3 may be connected to each other. For example, as shown in Figure 5 the support portion 5 may connect the central portion 2 and one end portion of the guide portion 3 to each other.

[0122] In the above-described embodiment, as shown in Figures 8A to 8C the bone surgical instrument 1 may further include a movable portion 8 that is connected to the guide portion 3 so as to be movable in the circumferential direction around the axis I. The movable portion 8 is a member for guiding the guide wire GW such that the guide wire GW is disposed in a predetermined positional relationship with respect to the hinge pin P1 inserted into the pin hole 2a. The movable portion 8 can also be applied to the bone surgical instruments 10 and 20.

[0123] The movable portion 8 has a first portion 81 connected to the guide portion 3 and a second portion 82 connected to the first portion 81.

[0124] The first portion 81 can move circumferentially along the outer surface of the guide portion 3. Figure 8C An example of the connection structure connecting the first portion 81 and the guide portion 3 is shown. In Figure 8C the guide portion 3 has a guide rail portion 3a protruding radially outward on the outer surface on the radially outer side. The first portion 81 is a substantially C-shaped ring-shaped member that surrounds the guide portion 3 and moves along the guide rail portion 3a. When the guide rail portion 3a is provided at the center in the thickness direction of the guide portion 3, the bone surgical instrument 1 can be used for both the left foot and the right foot by mounting the first portion 81 on the guide portion 3 upside down. The movable portion 8 may also have a screw 8a for temporarily fixing the first portion 81 with respect to the guide portion 3.

[0125] The connection structure is not limited to the above-described structure and can be arbitrarily changed as long as the position of the first portion 81 with respect to the guide portion 3 is stable in the vertical direction and the radial direction and the first portion 81 can move circumferentially with respect to the guide portion 3. The vertical direction is the direction parallel to the axis I.

[0126] The second portion 82 is disposed on the side opposite to the central portion 2 with respect to the guide portion 3. The second portion 82 has at least one guide hole 9 that guides the guide wire GW toward the axis I side in a direction parallel to the radial direction. The guide hole 9 is located on one side (lower side) in the vertical direction with respect to the guide portion 3 and penetrates the second portion 82 in a direction parallel to the radial direction. A plurality of guide holes 9 may be arranged in a line in the vertical direction so that a plurality of guide wires GW can be inserted into the tibia A simultaneously.

[0127] By using the pin hole 2a and the guide hole 9, the hinge pin P1 can be inserted into a predetermined position with respect to the guide wire GW already inserted into the tibia A, or the guide wire GW can be inserted into a predetermined position with respect to the hinge pin P1 already inserted into the tibia A.

[0128] The central axis K of the guide hole 9 is offset relative to the radial axis J in a direction orthogonal to both the axis I and the central axis K. The radial axis J is a radial axis passing through the axis I and parallel to the central axis K. The offset amount by which the central axis K is offset from the radial axis J is designed such that the distance Δd is approximately equal to the thickness of the osteotome, preferably the distance Δd is greater than 0 mm and 2 mm or less. The distance Δd is the distance in the offset direction from the axis I to the outer peripheral surface of the guide wire GW passing through the guide hole 9. When performing osteotomy of the osteotomy line L, the osteotome is inserted along the outer peripheral surface of the guide wire GW. By disposing the guide wire GW at a position away from the axis I corresponding to the thickness of the osteotome, the rotation center of the osteotomy can be correctly aligned with the hinge point H.

[0129] It can also be as Figures 9A to 9D shown, the second part 82 further includes a second guide portion 11 that guides the osteotome along a plane orthogonal to the axis I when performing osteotomy of the lower surface E. Figures 9A to 9C The second guide portion 11 of [] is a flat surface extending along a plane orthogonal to the axis I. Figure 9D The second guide portion 11 of [] is a flat slit extending along a plane orthogonal to the axis I. The flat surface and the slit have a width wider than the width of the osteotome. Considering the positional relationship among the front surface of the tibia A, the osteotome, and the guide wire GW, the second guide portion 11 is disposed in the vertical direction between the guide portion 3 and the guide hole 9 and extends from the guide hole 9 toward the fixing portion 6 side. When performing osteotomy of the lower surface E, by moving the osteotome along the second guide portion 11, the lower surface E can be formed perpendicular to the axis I and the hinge pin P1. When the lower surface E is inclined with respect to the hinge pin P1, it is possible that one of the hinge portion and the trochanter B becomes too thin. By providing the second guide portion 11, such an adverse situation can be prevented.

[0130] The guide hole 9 and the second guide portion 11 can also be movable relative to the guide portion 3 in the vertical direction. For example, it can be such that the second part 82 includes a first member connected to the first part 81 and a second member having the guide hole 9 and the second guide portion 11, and the second member is connected to the first member in a manner movable in the vertical direction relative to the first member. According to this structure, by adjusting the position of the second guide portion 11 in a direction parallel to the axis I, the position of the lower surface E and the thickness of the trochanter B can be adjusted.

[0131] It can also be as Figure 9B shown, the second part 82 has a flat guide slit 12 that is externally tangent to the guide hole 9 and extends in the vertical direction as a third guide portion for guiding the osteotome when performing osteotomy of the osteotomy line L. By inserting the osteotome into the tibia A via the guide slit 12, the tibia A can be osteotomized in parallel with the guide wire GW while maintaining the state in which the bone surgical instrument 1 is disposed on the tibia A.

[0132] As Figure 10 shown, when inserting the guide wire GW into the tibia A, a tubular guide sleeve GS for inserting the guide wire GW is sometimes used. Therefore, the guide hole 9 may also have an inner diameter slightly larger than the outer diameter of the guide sleeve GS to guide the guide sleeve GS.

[0133] When the guide hole 9 guides the guide sleeve GS, it may also be as Figure 9C and Figure 9D shown, the second part 82 has a slit 13, which has a width larger than the diameter of the guide wire GW and extends parallel to the guide hole 9.

[0134] The slit 13 is formed on the lower side of the guide hole 9 at the lowermost position and extends throughout the entire length of the guide hole 9, connecting the guide hole 9 to the outside of the second part 82. When a plurality of guide holes 9 are provided, all the guide holes 9 communicate in the vertical direction, and the guide wire GW can move between the guide hole 9 at the uppermost position and the guide hole 9 at the lowermost position in the vertical direction. By providing the slit 13, it is possible to remove the bone surgical instrument 1 upward from the tibia A while maintaining the state of inserting the hinge pin P1 and the guide wire GW into the tibia A. That is, after pulling out the guide sleeve GS from the guide hole 9, the entire bone surgical instrument 1 is moved upward, so that the guide wire GW can be pulled out from the guide hole 9 via the slit 13, and the hinge pin P1 can be pulled out from the pin hole 2a.

[0135] In Figures 8A to 9D it, the second part 82 is connected to the first part 81 in such a manner that it can linearly move in a direction parallel to the central axis K. In one example, the second part 82 has a slider 82a extending parallel to the central axis K, and the slider 82a is supported by the first part 81 in such a manner that it can move in its longitudinal direction. Thus, the second part 82 can be arranged as close as possible to the bone surface, and the guide wire GW can be inserted into the tibia A and osteotomy can be performed using an osteotome without play in the second part 82.

[0136] A positioning mechanism for positioning the second part 82 relative to the first part 81 may also be provided. For example, a ball plug (not shown) may be provided on the first part 81, and a plurality of holes 82b arranged in a row for receiving the ball plug may be provided on the slider 82a. In order to temporarily fix the second part 82 to the first part 81 with a stronger force, fixing members such as fixing screws may also be provided.

[0137] The second part 82 may also be fixed relative to the first part 81. In this case, the movable part 8 does not necessarily have to be composed of two parts 81 and 82, and may also be composed of a single component.

[0138] Reference Signs

[0139] 1, 10, 20 - bone surgical instruments, 2 - central part, 2a - pin hole, 3 - guiding part, 4 - slit, 5 - strut part, 6 - fixing part, 6a - fixing hole, 7 - contact surface, concave surface, 8 - movable part, 9 - guiding hole, 11 - second guiding part, A - tibia, B - tuberosity, GW - guide wire, H - hinge point (specific point), I - axis, P2 - fixing pin (fixing component).

Claims

1. An instrument for bone surgery, which guides an osteotome circumferentially around a specific point of a bone, characterized in that, Comprising: A central part, which is positioned at the above-mentioned specific point and shows the center of the slit; A guiding part, which has the above-mentioned slit in an arc shape or a substantially arc shape extending in the circumferential direction around the axis passing through the central part, the slit penetrates the guiding part in the direction parallel to the axis, and the guiding part guides the osteotome inserted into the slit in the circumferential direction around the axis; A fixing part, which fixes the guiding part to the bone using a fixing member; The central part has a pin hole penetrating the central part in the direction parallel to the axis.

2. The bone surgical instrument according to claim 1, characterized in that: The bone surgical instrument is used for osteotomy of the distal part of the tuberosity of the tibia.

3. The bone surgical instrument according to claim 1, characterized in that: The guiding part has a thickness such that the protruding amount of the front end of the osteotome from the slit is below a predetermined amount.

4. The bone surgical instrument according to any one of claims 1 to 3, characterized in that: The fixing part is provided on the opposite side of the central part with respect to the guiding part.

5. The bone surgical instrument according to any one of claims 1 to 3, characterized in that: The width of the slit is 0.5 mm to 1.5 mm larger than the thickness of the osteotome.

6. The bone surgical instrument according to any one of claims 1 to 3, characterized in that: When viewed from above in the direction along the axis, the outer shape of the guiding part is similar or substantially similar to the shape of the slit; The wall thickness of the edge part of the guiding part surrounding the slit is 1 mm to 5 mm.

7. The bone surgical instrument according to any one of claims 1 to 3, characterized in that: On one side in the direction along the axis, there is a contact surface in contact with the surface of the bone; This contact surface is a concave surface conforming to the shape of the surface of the bone.

8. The bone surgical instrument according to any one of claims 1 to 3, characterized in that: It comprises a pillar part connecting the central part and the guiding part to each other; This pillar part extends between the center of the circumferential direction of the central part and the guiding part and in the direction intersecting the axis.

9. The bone surgical instrument according to any one of claims 1 to 3, characterized in that: The slit extends along an arc with a constant radius of curvature.

10. The bone surgical instrument according to any one of claims 1 to 3, characterized in that: The slit extends along a curve with a radius of curvature gradually decreasing in the circumferential direction around the axis.

11. The bone surgical instrument according to claim 10, characterized in that: The slit is composed of a plurality of straight parts continuously connected to each other in the circumferential direction around the axis, and the plurality of straight parts respectively extend in the tangential direction or substantially tangential direction of the circumference centered on the axis.

12. The bone surgical instrument according to claim 11, characterized in that: The triangle with the two ends of each straight part and the central part as vertices is a right triangle with the straight part as the base; The opposite side of one right triangle and the hypotenuse of another right triangle adjacent to this one right triangle are shared.

13. The bone surgical instrument according to claim 10, wherein when displaced by a predetermined angle in the circumferential direction around the axis, the distance between the central portion and the slit is shortened by a predetermined length.

14. The bone surgical instrument according to any one of claims 1 to 3, wherein the distance between the central portion and the slit is 45 mm to 65 mm.

15. The bone surgical instrument according to any one of claims 1 to 3, wherein it includes a movable portion connected to the guiding portion so as to be movable in the circumferential direction around the axis, the movable portion has a guiding hole that penetrates in a direction parallel to the radial direction orthogonal to the axis, and guides a guide wire or a guiding sleeve for inserting the guide wire toward the axis, the outer peripheral surface of the guide wire passing through the guiding hole is disposed at a position away from the axis in an offset direction orthogonal to the axis and the central axis of the guiding hole.

16. The bone surgical instrument according to claim 15, wherein the movable portion includes a second guiding portion that guides the osteotome along a plane orthogonal to the axis.

Images