Crimping forceps

Abstract

To enable realization of crimping forceps capable of accommodating temporary fixation of surgical instruments having various sizes of openings.SOLUTION: The crimping forceps comprise a first arm section 111 extending from the proximal end to the distal end, and a second arm section 112 extending from the proximal end to the distal end and connected to the first arm section 111 at an intermediate connection point 115. The first arm section 111 and the second arm section 112 pivot between an approach position and a separated position, where a first fixing end portion 120 and a second fixing end portion 130 face each other in proximity in the approach position and are apart in the separated position. The first fixing end portion 120 includes a spherical portion 121 and a protruding portion 122 projecting from the spherical portion 121 toward the second fixing end portion 130. The protruding portion 122 has a maximum outer diameter smaller than the maximum outer diameter of the spherical portion 121.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to crimping forceps, and more particularly to crimping forceps used for temporarily fixing bone plates or surgical instruments for fixing bones or the like. [Background technology]

[0002] When treating a fracture, the fracture site may be fixed using a bone plate and screws. The bone plate is properly positioned on the bone at the fracture site, temporarily fixed to prevent movement, and then connected to the bone with screws.

[0003] Crimping forceps are used to temporarily fix bone plates. Some crimping forceps have a spherical tip that can be inserted into an opening formed in the bone plate for inserting a screw. The bone plate can be stabilized by inserting the tip into the opening and applying pressure. It has also been studied to make the tip spherical so that it can be partially inserted into the opening of the bone plate to grip it without slipping (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2017-524435 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the size of the spherical tip and the diameter of the opening are approximately the same, a problem occurs in which the tip becomes stuck in the opening and cannot be removed. While the problem of the tip becoming stuck can be avoided by making the tip size sufficiently larger than the size of the largest opening, the tip barely penetrates into a small opening, making alignment difficult and prone to slippage, resulting in an insufficient hold. Conversely, the problem of the tip becoming stuck can also be avoided by making the tip size sufficiently smaller than the diameter of the smallest opening, but in this case the bone plate will move. When a bone plate or surgical instrument has multiple openings of different sizes, existing designs require the use of multiple crimping forceps with different tip sizes to accommodate each opening.

[0006] Similar problems can occur not only with bone plates, but also with various surgical instruments that temporarily fix bones or body surfaces.

[0007] The present disclosure aims to realize a crimping forceps that is less likely to have the problem of the tip becoming stuck in the through-hole and that can be used to temporarily fix bone plates or surgical instruments having openings of various sizes. [Means for solving the problem]

[0008] One aspect of the crimping forceps disclosed herein comprises a first arm portion extending from a base end to a tip end, and a second arm portion extending from the base end to the tip end and connected to the first arm portion at an intermediate connection point, the first arm portion having a first fixing end formed at the tip, and the second arm portion having a second fixing end formed at the tip, the first arm portion and the second arm portion pivoting between a close position in which the first fixing end and the second fixing end face each other and are close to each other, and a separated position in which they are separated, the first fixing end having a spherical portion and a protruding portion protruding from the spherical portion toward the second fixing end, the protruding portion having a maximum outer diameter smaller than the maximum outer diameter of the spherical portion.

[0009] According to one aspect of the crimping forceps, it is possible to accommodate bone plates and other surgical instruments with openings of various sizes, while making it difficult for the tip to become stuck in the opening and become unable to be removed. In addition, since the protrusion allows positioning and the spherical portion allows pressure, alignment is easy and misalignment is unlikely to occur.

[0010] In one embodiment of the crimping forceps, the protrusions can be cylindrical. This configuration facilitates insertion of the protrusions into the openings where the bolts are secured. Furthermore, the axis of the protrusions can be aligned with the axis of the openings into which the protrusions are inserted, allowing the crimping forceps to be rotated horizontally, facilitating alignment of bone plates and avoiding interference with other surgical instruments.

[0011] In one embodiment of the crimping forceps, the extension of the central axis of the protrusion can pass through the center of the spherical portion. This configuration makes it easier to align the first fixing end with the opening. It also allows the spherical portion to firmly press against the outer edge of the opening when the protrusion is inserted into the opening.

[0012] In one aspect of the crimping forceps, the central axis of the protrusion can be aligned with the central axis of the tip of the first arm. This configuration allows the arms to apply a pressing force to the surgical instrument, such as a bone plate, from a direction nearly perpendicular to the bone plate, thereby achieving a more secure temporary fixation.

[0013] In one aspect of the crimping forceps, the protrusions can be dome-shaped with a height equal to or greater than the maximum radius. This configuration makes it less likely for the protrusions to become stuck in the opening, even if the opening is a counterbore. Furthermore, because rotation in a direction that misaligns the axis of the protrusions with the axis of the inserted opening is permitted to a certain extent, force can be applied to the opening even when the forceps is tilted, facilitating stable temporary fixation.

[0014] In one aspect of the crimping forceps, the angle between a tangent to the spherical portion and a tangent to the protrusion at the boundary between the spherical portion and the protrusion can be 90° or greater. This configuration makes it difficult for the protrusion to get stuck in the pilot hole of the countersunk hole.

[0015] In one embodiment of the crimping forceps, the first fixing end can be adapted to abut a bone plate or surgical instrument placed on a patient's bone, and the second fixing end can be adapted to abut a surface of the patient's body opposite the bone plate or surgical instrument. This configuration facilitates temporary fixation of the bone plate or other surgical instrument.

[0016] In one aspect of the crimping forceps, the bone plate or surgical instrument has a bolt fixing portion having a pilot hole and an upper hole formed on the surface side of the pilot hole and having a larger diameter than the pilot hole, and the first fixing end can be configured to be in at least one of a state in which the protruding portion abuts against the opening edge on the surface side of the pilot hole and a state in which the spherical portion abuts against the opening edge on the surface side of the upper hole when aligned with the bolt fixing portion. This configuration makes it less likely that the protruding portion will become stuck in the bolt fixing portion and become unable to be removed.

[0017] In one aspect of the crimping forceps, the forceps can be rotatable about the central axis of the protrusion when the first fixing end abuts against a surgical instrument placed on a patient's bone and the second fixing end abuts against the surface of the patient's body opposite the surgical instrument. This configuration allows the forceps to be rotated while lightly pressing against a bone plate, etc., making it easier to align the bone plate and avoid interference with other surgical instruments. [Effects of the Invention]

[0018] The crimping forceps of the present disclosure are less likely to have the problem of the tip portion becoming stuck in the through-hole, and can be used to temporarily fix bone plates or surgical instruments having openings of various sizes. [Brief explanation of the drawings]

[0019] [Figure 1]FIG. 1 is a side view of one embodiment of a crimping forceps. [Figure 2] FIG. 2 is an enlarged side view of a first fixing end portion of the crimping forceps according to one embodiment. [Figure 3] FIG. 10 is a side view showing a modified example of the first fixing end portion. [Figure 4] FIG. 10 is a partial cross-sectional view showing an example of insertion into a countersunk hole. DETAILED DESCRIPTION OF THE INVENTION

[0020] The crimping forceps of one embodiment can press and temporarily fix a bone plate or other surgical instrument against a patient's bone or body surface. As shown in Fig. 1, the crimping forceps of one embodiment has a first arm portion 111 and a second arm portion 112 connected to each other at an intermediate connection point 115. A first fixing end portion 120 is formed at the tip of the first arm portion 111, and a finger hole 151 and a finger hook 153 are formed at the base end. A second fixing end portion 130 is formed at the tip of the second arm portion 112, and a finger hole 152 is formed at the base end.

[0021] The first arm portion 111 and the second arm portion 112 pivot about a connecting point 115 between a close position where their tip ends are close to each other and a separated position where they are separated from each other. Furthermore, the ratchet portion 117 allows the first arm portion 111 and the second arm portion 112 to be releasably held at any position between the close position and the separated position.

[0022] In the approach position, the first fixing end 120 and the second fixing end 130 face each other. Therefore, a bone plate can be sandwiched and pressed between the first fixing end 120 and the second fixing end 130. For example, the bone plate can be placed on the bone at the treatment site of the patient, the first fixing end 120 abutting against the bone plate, and the second fixing end 130 abutting against the patient's skin on the side opposite the bone plate, thereby temporarily fixing the bone plate to the treatment site. During temporary fixation, the first arm portion 111 and the second arm portion 112 are pivoted to adjust the distance between the first fixing end 120 and the second fixing end 130, and the ratchet portion 117 holds them in a position where an appropriate pressing force can be applied.

[0023] As shown enlarged in Figure 2, the first fixing end 120 has a spherical portion 121 and a protruding portion 122 that protrudes from the spherical portion 121 toward the second fixing end 130. The protruding portion 122 is formed so that its maximum outer diameter is smaller than that of the spherical portion 121. Almost the entire protruding portion 122 can be inserted into an opening that is a bolt fixing portion provided in the bone plate. The spherical portion 121, which has an outer diameter larger than that of the protruding portion 122, stops at the entrance of the opening and is not inserted into the opening, or only partially inserted.

[0024] Because only a portion of the spherical portion 121 is inserted into the opening, it can firmly press against the bone plate around the opening, allowing the bone plate to be firmly temporarily fixed. Furthermore, because the protruding portion 122, which has a small outer diameter, is inserted into the opening and functions as a guide, even if the spherical portion 121 is barely inserted into the opening of the bone plate, it is possible to prevent slippage or misalignment when holding the bone plate. Because the proximal end portion of the protruding portion 122 is the spherical portion 121, a curved surface abuts against the edge of the opening of the bone plate. The curved abutment surface has the advantage of being able to uniformly press against the outer edge of the opening of the bone plate, even when the first fixing end portion 120 does not abut perpendicularly against the bone plate, compared to when the abutment surface is flat. Furthermore, because only a portion of the spherical portion 121 is inserted into the opening, it is less likely that the spherical portion 121 will get stuck in the opening and become stuck.

[0025] The maximum outer diameters of spherical portion 121 and protruding portion 122 can be appropriately selected depending on the size of the opening of the bone plate to be used. In the case of a bone plate used for arm fractures, the diameter of the opening is about 3 mm, and the maximum outer diameter of protruding portion 122 is preferably 90% or less of the diameter of the opening. The thickness of the bone plate is about 3 mm, and the length of the protruding portion is preferably 90% or less of the thickness of the bone plate.

[0026] The shape of the protrusion 122 is not particularly limited, but since the openings that serve as the bolt fixing portions of the bone plate are usually circular, it is preferable that the protrusion be cylindrical or have a truncated cone shape with slightly inclined sides that taper to a point. A cylindrical or truncated cone shape can also be used for openings other than circular, such as elongated holes. The opening is not limited to the bolt fixing portion.

[0027] It is preferable that the extension line of the central axis of the cylindrical or truncated cone-shaped protrusion 122 passes through the center of the spherical portion 121. This makes it easy to align the first fixing end portion 120, and also enables the spherical portion 121 to firmly press against the outer edge of the opening of the bone plate when the protrusion 122 is inserted into the opening.

[0028] In this embodiment, the first arm portion 111 has a curved portion 124 that is curved so that it temporarily separates from the second arm portion 112 on the tip side of the connection point 115 and then the tip portion approaches the second arm portion 112 again. A constricted portion 125 that is thinner than the other parts of the curved portion 124 and the spherical portion 121 is formed at the tip of the curved portion 124, and the first fixing end portion 120 is connected to the first arm portion 111 via the constricted portion 125.

[0029] By forming the curved portion 124, a space is created between the first arm portion 111 and the second arm portion 112, so that the first arm portion 111 does not interfere with the patient's body and the first fixing end portion 120 can be easily brought close to the surgical site where the bone plate is to be fixed. Furthermore, by providing the constricted portion 125, interference with the bone plate and surgical instruments can be avoided, so the three-dimensional range of motion in which the crimping forceps can be tilted can be expanded. Note that the curved portion 124 and the constricted portion 125 may be provided as needed, and may also be omitted.

[0030] It is preferable that the extension of the central axis of the protruding portion 122 passes through the center of the spherical portion 121 and coincides with the central axis of the tip of the curved portion 124. This allows the pressing force of the arm to be applied to the bone plate from a direction nearly perpendicular to the bone plate, thereby achieving more secure temporary fixation. When a constricted portion 125 is provided, it is preferable that the central axis of the extension of the central axis of the protruding portion 122 coincides with the central axis of the constricted portion 125. If there is no constricted portion, it is preferable that the tip of the curved portion, approximately 5.5 to 6.5 mm long, be straight, and that its central axis coincide with the center of the spherical portion. It is also preferable that the direction in which the plane (median plane) that is symmetrical when the curved portion 124 is viewed from above coincides with the central axis.

[0031] In this embodiment, the second fixing end 130 is disk-shaped, and in the approach position, the main surface of the disk faces the first fixing end 120. In the approach position, the main surface of the disk is preferably nearly perpendicular to the central axis of the protruding portion 122. By making the angle nearly perpendicular, it becomes easier to press the bone plate. However, it may be slightly inclined, taking into consideration the shape of the treatment site, etc. The second fixing end 130 is not limited to a disk shape, but it is preferable that the second fixing end 130 has a shape that presses over a relatively wide area so as to minimize pain to the patient's skin.

[0032] The opening 210 of the bone plate 200, such as the bolt fixing portion, may be a so-called countersunk hole in which a pilot hole 212 and an upper hole 211 with a larger diameter than the pilot hole 212 are formed on the surface side. The cylindrical or truncated cone-shaped protrusion 122 can also be used for such a countersunk hole. When the opening 210 is a countersunk hole, a dome-shaped protrusion 122A as shown in FIG. 3 is also useful.

[0033] By making the maximum outer diameter of spherical portion 121 larger than the diameter of upper hole 211 and making the maximum outer diameter of dome-shaped protruding portion 122A smaller than the diameter of upper hole 211, protruding portion 122A is inserted into the upper hole, making it possible to temporarily fix spherical portion 121 while guiding the position thereof. Furthermore, by preventing spherical portion 121 from entering upper hole 211, the depth to which first fixing end portion 120 as a whole is inserted into opening 210 can be limited, making it less likely that protruding portion 122A will become too deeply stuck in lower hole 212 and become unable to be removed.

[0034] In this case, it is preferable that the angle formed between a tangent to spherical portion 121 and a tangent to protrusion 122A at the boundary between spherical portion 121 and dome-shaped protrusion 122A is 90° or more. In this case, as shown in Fig. 4, spherical portion 121 abuts against opening edge (edge) 215 on the surface of upper hole 211, and the vicinity of the boundary between spherical portion 121 and dome-shaped protrusion 122A is more likely to abut against opening edge (edge ​​between lower hole 212 and upper hole 215) 216 on the surface side of lower hole 212. This makes it more unlikely that protrusion 122A will become deeply stuck in lower hole 212 and become unable to be removed.

[0035] The protrusion 122A is preferably hemispherical or larger. In this case, the height of the protrusion 122A is greater than the maximum radius. Therefore, if the outer diameter of the protrusion 122A is sufficiently smaller than the lower hole 212, the depth of insertion into the opening can be increased, limiting the range of motion and improving stability. Furthermore, if the outer diameter of the protrusion 122A is sufficiently larger than the lower hole 212, the protrusion 122A abuts against the end of the lower hole 212, increasing the contact area of ​​the protrusion 122A and increasing the three-dimensional range of motion. When the protrusion 122A is hemispherical or larger, it is preferable to smoothly connect the spherical portion 121 and the protrusion 122A to prevent a deep constriction. This makes it less likely that the protrusion 122A will get stuck in the lower hole. The protrusion 122A may also be dome-shaped, less than a hemisphere, with a height smaller than the maximum radius.

[0036] When the protrusion 122 is cylindrical or truncated cone-shaped, the central axis of the protrusion 122 and the central axis of the opening in the bone plate are maintained in a state where they are approximately aligned when the spherical portion 121 is lightly pressed against the surface of the bone plate. Therefore, the bone plate can be rotated horizontally with some freedom around the central axis of the opening into which the protrusion 122 is inserted. Meanwhile, three-dimensional movement, such as tilting the central axis of the protrusion 122 away from the central axis of the opening, is significantly restricted. This allows for fine adjustment of the position of the bone plate while preventing significant misalignment.

[0037] In the case of the dome-shaped protrusion 122A, horizontal rotation about the opening into which the protrusion 122A is inserted can be performed with some freedom, as in the case of the cylindrical or truncated cone-shaped protrusion 122. In addition, the range of three-dimensional movement, such as tilting the axis of the opening, is greater than in the case of the cylindrical or truncated cone-shaped protrusion 122. When inserting and fixing a bolt obliquely relative to the main surface of a bone plate, using a crimping forceps having the dome-shaped protrusion 122A increases the degree of freedom in positioning.

[0038] In this embodiment, ratchet portion 117 is provided closer to the base end than the connection point of first arm portion 111, and is formed by a toothed plate portion 171 extending toward second arm portion 112, and a pawl portion 172 provided on second arm portion 112 and releasably engaging with the teeth of toothed plate portion 171. Ratchet portion 117 is not limited to this configuration, and various other configurations can be adopted.

[0039] The first arm portion 111 and the second arm portion 112 can be formed from various materials that can ensure the required strength. For example, they can be formed from stainless steel or the like. The first arm portion 111 and the second arm portion 112 can each be formed as a single unit, or they can be formed by combining multiple parts. For example, the curved portion 124 of the first arm portion 111 can be formed separately from the base end and then combined. In this way, the curved portion 124 can be replaced with one having a shape more suitable for temporary fixation. Furthermore, the first fixing end portion 120 can also be made replaceable. The second arm portion 112 can also be formed as a single unit or by combining multiple parts.

[0040] Although an example has been shown in which finger holes and finger hooks are provided at the base ends of first arm portion 111 and second arm portion 112, the shapes are not limited to this and various shapes that are easy to grip can be adopted.

[0041] In the present embodiment and modified examples, an example has been shown in which the surgical instrument is a bone plate, but the crimping forceps of the present disclosure are also useful for temporarily fixing surgical instruments other than bone plates. [Industrial Applicability]

[0042] The crimping forceps of the present disclosure are capable of temporarily fixing surgical instruments having openings of various sizes and are useful in the medical field. [Explanation of symbols]

[0043] 111 First arm 112 Second arm 115 connection point 117 Ratchet section 120 first fixing end 121 Sphere 122 Protrusion 122A Protrusion 124 curved section 125 Waist 130 second fixing end 151 finger hole 152 finger hole 153 Finger rest 171 Toothed plate part 172 Pawl 200 bone plates 210 Opening 211 Upper hole 212 Pre-hole 215 Opening edge 216 Opening edge

Claims

1. a first arm portion extending from a base end to a tip end; a second arm portion extending from a base end to a tip end and connected to the first arm portion at an intermediate connection point; the first arm portion has a first fixing end portion formed at a tip thereof, the second arm portion has a second fixing end portion formed at a tip thereof, the first arm portion and the second arm portion pivot between a close position in which the first fixing end portion and the second fixing end portion are opposed to each other and close to each other, and a separate position in which the first fixing end portion and the second fixing end portion are separated from each other; the first fixing end portion has a spherical portion and a protruding portion protruding from the spherical portion toward the second fixing end portion, The maximum outer diameter of the protrusion is smaller than the maximum outer diameter of the spherical portion.

2. The crimping forceps of claim 1 , wherein the protrusion is cylindrical.

3. The crimping forceps according to claim 2 , wherein an extension line of the central axis of the protrusion passes through the center of the spherical portion.

4. The crimping forceps according to claim 3 , wherein a central axis of the protrusion coincides with a central axis of the tip of the first arm portion.

5. The crimping forceps according to claim 1 , wherein the protrusions are dome-shaped with a height equal to or greater than the maximum radius.

6. The crimping forceps according to claim 5, wherein an angle formed between a tangent to the spherical portion and a tangent to the protrusion at a boundary between the spherical portion and the protrusion is 90° or greater.

7. the first fixation end abuts against a bone plate or a surgical instrument placed on a patient's bone; The crimping forceps according to claim 1 , wherein the second fixing end abuts against a surface of the patient's body opposite the bone plate or the surgical instrument.

8. the bone plate or the surgical instrument has a bolt fixing portion having a pilot hole and an upper hole formed on a surface side of the pilot hole and having a larger diameter than the pilot hole, 8. The crimping forceps according to claim 7, wherein when the first fixing end is aligned with the bolt fixing portion, the first fixing end is in at least one of a state in which the protruding portion abuts against an opening edge on a front surface side of the lower hole and a state in which the spherical portion abuts against an opening edge on a front surface side of the upper hole.

9. 2. The crimping forceps according to claim 1, wherein the crimping forceps is rotatable about a central axis of the protrusion when the first fixing end abuts against a bone plate or a surgical instrument placed on a bone of a patient and the second fixing end abuts against a surface of the patient's body opposite the surgical instrument.

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