Bone Plate

Abstract

To provide a plate for bone capable of being freely deformed according to a shape of a bone and a state of a bone fracture state, and properly treating a bone fracture on an end part of a long pipe bone.SOLUTION: A plate 1 for bone comprises: a plate main body part 10 extending in a longitudinal direction; a head part 20 provided on one longitudinal side of the plate main body part 10; and a plurality of tabs 30a, 30b, 40, 50 which is provided on a peripheral edge part of the head part 20. The plurality of tabs comprises: a plurality of first type tabs 30a, 30b which is arranged in a width direction of the head part 20 in parallel; and a second type tab 40 which is provided on a side part of the plurality of first type tabs 30a, 30b. The first type tabs 30a, 30b have a first connection part 32a, 32b which can be deformed and bent. The second type tab 40 has a second connection part 42 which has a cross section smaller than that of the first connection parts 32a, 32b, and can be deformed and bent, and can be deformed and twisted, and extends outward from the head part 20 by the second connection part 42.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to bone plates used in the treatment of fractures of the ends of long bones. [Background technology]

[0002] Human bones that are long (longer than they are wide) are called long bones. These bones have a diaphysis, which makes up the middle part, an epiphysis, which makes up both ends, and a metaphysis, which makes up the part between the diaphysis and the epiphysis. For example, there are two long bones in the lower leg, from the knee to the ankle: the thin one on the outside, the fibula, and the thick one on the inside, the tibia. The tibia, at its distal end closest to the foot, forms the ankle joint with the fibula and talus. Strong external forces applied to the ankle joint can cause a fracture of the distal tibia near the ankle joint. Distal tibia fractures can result in many broken pieces that need to be reattached. In the treatment of fractures of the ends of long bones, including fractures of the distal tibia, bone plates are used that are attached in a bridging manner to the fracture fragments and the bone body to fix them together after the position and orientation of the fracture fragments are restored.

[0003] Patent Document 1 (Japanese Patent No. 5507463) discloses an anterolateral plate for the anterolateral surface of the distal tibia as a bone plate used to treat fractures of the distal tibia, which includes a shaft twisted about a longitudinal axis, a distal head extending only to one side of the shaft and widening relative to the shaft to transition to a lateral extension, and a plurality of distal tabs connected to the distal end of the distal head, each of which includes a screw hole and is connected to the distal end of the head by a deformable bridge. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5507463 Summary of the Invention [Problem to be solved by the invention]

[0005] The shape of bones varies from patient to patient, and the condition of the fracture (such as the position and orientation of the fracture fragments) also varies from case to case. Therefore, in clinical settings, doctors may deform bone plates, which are manufactured in advance with a predetermined shape, to fit the shape of the bone and the condition of the fracture. For example, in the treatment of the distal tibia fracture described above, there is a demand for bone plates that can more appropriately treat the fracture (by restoring the position and orientation of the fracture fragments and maintaining that state) (in other words, bone plates that can be more freely deformed to fit the shape of the bone and the condition of the fracture) in order to reduce, even if only slightly, the functional impairment of the ankle joint and discomfort after healing. Therefore, an object of the present invention is to provide a bone plate used for treating fractures of the ends of long bones, which can be more freely deformed to suit the shape of the bone and the condition of the fractured part, and can more appropriately treat fractures of the ends of long bones. [Means for solving the problem]

[0006] The above objectives are achieved by the following: (1) A bone plate used to treat fractures of the end of a long bone, a plate body portion extending in a longitudinal direction; a head portion located on one side of the plate body portion in the longitudinal direction and wider than the portion of the plate body portion on the one side in the longitudinal direction; and a plurality of tabs provided on a peripheral edge of the head portion, the head portion has a plurality of head portion through-holes into which shanks of bone screws can be inserted; the plurality of tabs include a plurality of first type tabs arranged in parallel in the width direction of the head portion and a plurality of second type tabs located to the sides of the plurality of first type tabs, The first type tab has a first tab body and a bendable And cannot be twisteda first connecting portion, the first connecting portion being provided so as to extend from an end portion on one side in the longitudinal direction of the head portion to one side in the longitudinal direction, a cross-sectional area of ​​the first connection portion is smaller than a cross-sectional area of ​​the first tab body portion, and a width w1 of the first connection portion is larger than a thickness t1 of the first connection portion; The second type tab has a second tab body portion having a second tab through-hole. And, the song and a second connecting portion that is bendable and twistable, and is provided so as to extend outward from the head portion by the second connecting portion. a cross-sectional area of ​​the second connection portion is smaller than a cross-sectional area of ​​the second tab body portion, a width w2 of the second connection portion is larger than a thickness t2 of the second connection portion, a value of a ratio (w2 / t2) of the width w2 of the second connection portion to the thickness t2 of the second connection portion is smaller than a value of a ratio (w1 / t1) of the width w1 of the first connection portion to the thickness t1 of the first connection portion, and the bone plate is made of a titanium alloy, pure titanium, or stainless steel. Bone plates.

[0007] (2) The first tab body portion of the first type tab has a first tab through-hole, The bone plate according to (1) above, wherein the first tab through-hole and the second tab through-hole have the same diameter as the head portion through-hole. (3) The plurality of tabs includes a third type tab provided on a side opposite to a side on which the plurality of first type tabs are provided with the second type tab, The third type tab has a third tab body portion having a third tab through-hole. And, the song Transformable And cannot be twisted and a third connection portion, the third connection portion being provided to extend outward from the head portion in a direction different from that of the first type tab, a cross-sectional area of ​​the third connection portion is smaller than a cross-sectional area of ​​the third tab main body portion, a width w3 of the third connection portion is larger than a thickness t3 of the third connection portion, and a ratio (w3 / t3) of the width w3 of the third connection portion to the thickness t3 of the third connection portion is larger than a ratio (w2 / t2) of the width w2 of the second connection portion to the thickness t2 of the second connection portion, The bone plate according to (1) or (2) above, wherein the third tab through-hole has the same diameter as the head portion through-hole. (4) Two first type tabs are provided. 2 one The aforementioned The first tab body portions of the first type tabs each have a first tab through-hole, and the centers of the two head portion through-holes formed on one side of the head portion in the longitudinal direction are But, 2 one The aforementioned The bone plate according to any one of (1) to (3) above, wherein the first tab through-holes are located between the centers of the first tab through-holes and on the other side in the longitudinal direction. (5) In the state before deformation of the first connecting portion 2 one The aforementionedThe bone plate according to (4) above, wherein the axis extending toward the bone of the first tab through-hole of one of the first type tabs passes between the axes extending toward the bone of the two head portion through-holes formed on one side of the longitudinal direction in the head portion. (6) The first tab body portion of the first type tab has a width that increases toward one side in the longitudinal direction. Rudai The bone plate according to any one of (1) to (5) above, which has a shaped configuration. (7) The bone plate according to any one of (1) to (6) above, wherein the first tab body portion of the first type tab has a first tab through-hole, and the projected area of ​​the outer shape of the first tab body portion is four or more times the projected area of ​​the first tab through-hole in the axial direction of the first tab through-hole. (8) The bone plate according to any one of (1) to (7) above, wherein the bone plate is a bone plate used for treating a fracture of the distal tibia. [Effects of the Invention]

[0008] The bone plate of the present invention comprises a plate body portion extending in the longitudinal direction, a head portion located on one longitudinal side of the plate body portion and wider than the portion of the plate body portion on that longitudinal side, and a plurality of tabs provided on the peripheral edge of the head portion, the plurality of tabs including a plurality of first type tabs arranged in parallel in the width direction of the head portion and a second type tab located to the side of the plurality of first type tabs, the first type tab having a first tab body portion and a first connecting portion that is bendable and deformable, and is provided so as to extend from an end of one longitudinal side of the head portion in one longitudinal direction by the first connecting portion, and the second type tab having a second tab body portion with a second tab through-hole and a second connecting portion that has a smaller cross-sectional area than the first connecting portion and is bendable and twistable, and is provided so as to extend outward from the head portion by the second connecting portion. This allows the bone plate to be more freely deformed to match the shape of the bone and the condition of the fractured portion by appropriately bending and deforming the first connection portion of the first type tab, or by appropriately bending and / or twisting the second connection portion of the second type tab, thereby enabling more appropriate treatment of fractures at the ends of long bones. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view showing an embodiment of a bone plate according to the present invention. [Figure 2] FIG. 2 is a left side view showing an embodiment of the bone plate of the present invention. [Figure 3] FIG. 3 is a right side view showing an embodiment of the bone plate of the present invention. [Figure 4] FIG. 4 is a plan view showing an embodiment of the bone plate of the present invention. [Figure 5] FIG. 5 is a bottom view of an embodiment of the bone plate of the present invention. [Figure 6] FIG. 6 is a rear view of an embodiment of the bone plate of the present invention. [Figure 7] FIG. 7 is an enlarged explanatory view of the cross section AA of FIG. [Figure 8] FIG. 8 is an enlarged explanatory view of the cross section BB in FIG. [Figure 9] FIG. 9 is an enlarged explanatory view of the CC cross section of FIG. [Figure 10] FIG. 10 is an explanatory view showing an example in which the bone plate shown in FIG. 1 is used in the distal part of the tibia. [Figure 11] FIG. 11 is a front view showing an example of a bone screw that can be used with the bone plate shown in FIG. [Figure 12] FIG. 12 is a front view showing another embodiment of the bone plate of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] The bone plate of the present invention will be described with reference to the embodiment shown in the drawings. The bone plate 1 of the present invention is used to treat fractures of the end of a long bone and comprises a plate body 10 extending in the longitudinal direction (vertical direction in FIG. 1 ), a head 20 located on one longitudinal side (upper side in FIG. 1 ) of the plate body 10 and wider than the longitudinal side of the plate body 10, and a plurality of tabs (30, 40, 50) provided on the periphery of the head 20. The head 20 has a plurality of head through-holes 22 into which shanks 71 of bone screws 7, which will be described later, can be inserted. The plurality of tabs (30, 40, 50) comprises a plurality of first-type tabs 30 (30a, 30b) arranged in parallel across the width of the head 20 (horizontal direction in FIG. 1 ) and a second-type tab 40 located to the side of the first-type tabs 30 (30a, 30b) (on the left side of the head 20 in FIG. 1 ). The first type tab 30 (30a, 30b) includes a first tab main body 31 (31a, 31b) and a bendable first connecting portion 32 (32a, 32b), and is provided so as to extend from one end of the head portion 20 in the longitudinal direction toward one side in the longitudinal direction (upward in FIG. 1) by the first connecting portion 32 (32a, 32b). The second type tab 40 includes a second tab main body 41 having a second tab through-hole 43, and a bendable and twistable second connecting portion 42 having a smaller cross-sectional area than the first connecting portion 32 (32a, 32b), and is provided so as to extend outward from the head portion 20 by the second connecting portion 42. The bone plate 1 shown in this example is a bone plate (anterolateral tibial plate) used on the anterior lateral surface of the distal tibia, and is for the left foot (the one for the right foot is symmetrical (except for the direction of the spiral of the female thread portion)). In the following description, one longitudinal direction may be referred to as the distal direction and the other longitudinal direction as the proximal direction, depending on the manner in which the bone plate 1 is used on the distal tibia.

[0011] The plate body 10 of the bone plate 1 extends in the longitudinal direction and constitutes the proximal portion of the bone plate 1. The plate body 10 is primarily placed relative to the diaphysis portion, which constitutes the central portion of a long bone. The plate body 10 is twisted around its longitudinal axis and has an upper surface 11 and a lower surface 12. When the bone plate 1 is in use, the lower surface 12 faces the bone (the side that comes into contact with the bone). The plate body 10 of the bone plate 1 is provided with a fixing hole 13 that is rectangular (elliptical) with rounded corners in a plan view. The fixing hole 13 does not have a female thread on its inner surface. In a typical procedure, the fixing hole 13 and a bone screw (which does not have a threaded portion (male threaded portion) on its head) are used to initially fix the bone plate 1 to the target site (the diaphysis portion of a long bone).

[0012] A plurality of screw holes 14 (two on the proximal side of the fixing holes 13 in this example) are provided around the fixing holes 13 in the plate body 10 for fixing bone screws. A female thread is provided on the inner surface of the screw holes 14. The female thread is formed parallel to the axial direction of the screw holes 14. The female thread can be threaded with a male thread provided on the head of a bone screw (not shown). The bone screw is attached and fixed to the bone plate 1 (plate body 10) by being threaded into the female thread. Furthermore, a plate body through hole 15 is provided on the distal side of the fixing holes 13 in the plate body 10, into which a shank 71 of a bone screw 7 (described later) can be inserted (in other words, the diameter of the plate body through hole 15 is larger than that of the shank 71). In this embodiment, the plate body through hole 15 has the same diameter as a head through hole 22 (described later) (the pilot hole diameter before the female thread is formed is the same). In this embodiment, the inner surface of the plate body through hole 15 is provided with a female thread, which can be engaged or screwed with a male thread provided on the head 72 of the bone screw 7, which will be described later. This allows the same bone screw 7 as that applied to the head through hole 22 to be applied to the plate body through hole 15. Furthermore, as shown in FIG. 1 , in addition to the fixing holes 13 and the screw holes 14, the plate body 10 is formed with a plurality of small holes through which guide pins (thin, pointed metal pins, also known as K-wires or Kirschner wires) can be inserted. This allows the bone plate 1 to be temporarily fixed using the guide pins.

[0013] The distal end of the plate body 10 is provided with a head portion 20 that is wider than the distal portion of the plate body 10. The head portion 20 is primarily positioned at the epiphysis (which may include part of the metaphysis) that constitutes the end of a long bone. In this embodiment, the head portion 20 gradually widens in the distal direction and toward one side in the width direction (the right side in FIG. 1 ). As shown in FIG. 1 , this results in two recesses 23, 23 being formed in the outer shape of the bone plate 1, thereby reducing the area where the bone plate 1 comes into contact with the skin or the like. The head portion 20 has an upper surface 24 and a lower surface 25 that are continuous with the upper surface 11 and the lower surface 12 of the plate body 10, respectively. When the bone plate 1 is in use, the lower surface 25 faces the bone (the side that contacts the bone). As shown in FIG. 4 , the head portion 20 is curved so that it is convex toward the upper surface (the lower side in FIG. 4 ).

[0014] In the bone plate 1, the plate body 10 and the head 20 constitute the base plate of the bone plate 1. In this embodiment, the lower surface (lower surface 12 and lower surface 25) of the base plate of the bone plate 1 is a continuous free-form surface (no geometrically shaped portion) as a whole.

[0015] The head portion 20 has a plurality of (here, five) head portion through-holes 22 into which shanks 71 of bone screws 7 (described later) can be inserted (in other words, the diameters are larger than the shanks 71). In this embodiment, all of the head portion through-holes 22 have the same diameter (the diameter of the pilot holes before the formation of the female threads is the same). In this embodiment, the inner surfaces of the head portion through-holes 22 are provided with female threads that can be engaged or screwed with male threads provided on the heads 72 of the bone screws 7 (described later). This allows the same bone screws 7 to be applied to the plurality of head portion through-holes 22. In addition to the head portion through-holes 22, as shown in FIG. 1 , the head portion 20 also has a plurality of small holes through which guide pins (thin, pointed metal pins, also known as K-wires or Kirschner wires) can be inserted. This makes it possible to use the guide pins to check the insertion mode (position, direction, insertion amount, etc.) of the bone screws 7 inserted into the head portion through-holes 22 and to temporarily fix the fracture fragments.

[0016] A plurality of tabs (30, 40, 50) are provided on the periphery of the head portion 20. In this embodiment, the plurality of tabs (30, 40, 50) include a plurality (two in this example) of first type tabs 30 (hereinafter, in this example, the configuration related to the first type tab 30 provided on the left side in FIG. 1 may be described by adding the suffix "a" to the reference numeral, and the configuration related to the first type tab 30 provided on the right side may be described by adding the suffix "b" to the reference numeral), a second type tab 40, and a third type tab 50.

[0017] The first type tabs 30a, 30b are arranged in parallel in the width direction and extend distally from the distal end of the head portion 20. The first type tabs 30a, 30b have bendable first connecting portions 32a, 32b, and are arranged to extend distally from the distal end of the head portion 20 via the first connecting portions 32a, 32b. The portions of the first type tabs 30a, 30b distal to the first connecting portions 32a, 32b (portions other than the first connecting portions 32a, 32b) form first tab main bodies 31a, 31b.

[0018] The cross-sectional areas of the first connection portions 32a, 32b are smaller than the cross-sectional areas of the first tab main bodies 31a, 31b. More specifically, as shown in FIGS. 1 and 7, the first connection portions 32a, 32b have a narrower width (w1) than the first tab main bodies 31a, 31b. In other words, in the first type tabs 30a, 30b, the first connection portions 32a, 32b have a smaller rigidity than the first tab main bodies 31a, 31b. This allows the first type tabs 30a, 30b to bend and deform in the upper or lower direction of the plate main body 10 and the head portion 20. Note that the thickness (t1) of the first connection portions 32a, 32b may be smaller than the thickness of the first tab main bodies 31a, 31b.

[0019] It is desirable that the first connecting portions 32a, 32b bendable but not twistable (i.e., when a doctor performs surgery, the first type tabs 30a, 30b cannot be twisted around the axis in the extension direction). For example, the width w1 (approximately 2.4 to 2.6 mm in this embodiment) of the first connecting portions 32a, 32b is preferably larger than the thickness t1 (approximately 1.59 to 1.69 mm in this embodiment) of the first connecting portions 32a, 32b, and the ratio of the width w1 to the thickness t1 (w1 / t1) is preferably in the range of 1.5 to 2.0. This allows the first connecting portions 32a, 32b to bendable but not twistable in relation to the second connecting portion 42 described below.

[0020] The first tab main bodies 31 (31a, 31b) are located on the distal side (the extension direction side of the first type tab 30) of the first type tab 30. In this embodiment, as shown in Fig. 1, the first tab main bodies 31a, 31b of the first type tabs 30a, 30b have a generally trapezoidal shape that widens in the distal direction (one side of the longitudinal direction, in other words, toward the epiphysis of the long bone). This allows the first tab main bodies 31a, 31b (particularly the distal side portion where the width of the first tab main bodies 31a, 31b is wider) to appropriately support the fractured portion (particularly the bone at the epiphysis and fracture fragments).

[0021] In this embodiment, the first tab main bodies 31a, 31b of the first type tabs 30a, 30b expand at substantially equal angles on both widthwise sides, but the angles may be different on both widthwise sides. Preferably, the first tab main bodies 31a, 31b of adjacent first type tabs 30a, 30b have opposing sides (the right side of the first tab main body 31a and the left side of the first tab main body 31b) expanding toward the first tab main body 31b, 31a of the adjacent first type tabs 30b, 30a. Preferably, the trapezoidal first type tabs 30a, 30b have a maximum width dimension that is 1.5 times or more the minimum width dimension (here, the width dimension of the base end (the end on the first connection portion 32a, 32b side) of the first type tabs 30a, 30b).

[0022] The first tab main bodies 31a, 31b of the first type tabs 30a, 30b have first tab through-holes 33a, 33b, respectively. In this embodiment, the first tab through-holes 33a, 33b have the same diameter as the head through-hole 22 (the diameter of the pilot hole before the female thread is formed is the same). Furthermore, the first tab through-holes 33a, 33b of the first type tabs 30a, 30b have female threads on their inner surfaces, which can be engaged or threaded with male threads provided on the head 72 of the bone screw 7, which will be described later. This allows the same bone screw 7 used for the head through-hole 22 to be applied to the first tab through-holes 33a, 33b.

[0023] As described above, the first tab main bodies 31a, 31b of the first type tabs 30a, 30b have the first tab through-holes 33a, 33b. Here, in terms of the projected area as viewed in the axial direction of the first tab through-holes 33a, 33b, it is preferable that the projected area of ​​the outer shape of the first tab main bodies 31a, 31b be four or more times the projected area of ​​the first tab through-holes 33a, 33b (area of ​​the pilot holes). This allows the first tab main bodies 31a, 31b to appropriately support the fractured portion (particularly, the bone at the epiphysis or fracture fragments) even when the first tab through-holes 33a, 33b are formed in the first tab main bodies 31a, 31b.

[0024] Specifically, in this embodiment, the projected area of ​​the outer shape of the first tab main body portions 31a and 31b is 55.6 mm 2 The projected area of ​​the first tab through-holes 33a and 33b is 12.1 mm 2 (The pilot hole diameter before forming the female thread is 3.93 mm), and the projected area of ​​the outer shape of first tab main bodies 31a, 31b is 4.6 times the projected area of ​​first tab through-holes 33a, 33b. Note that the projected area of ​​the outer shape of first tab main bodies 31a, 31b is preferably in the range of 4 to 5 times the projected area (area of ​​the pilot hole) of first tab through-holes 33a, 33b.

[0025] The bone plate 1 of this embodiment is provided with two first-type tabs 30 (30a, 30b), and first tab main bodies 31a, 31b of the two first-type tabs 30a, 30b have first tab through-holes 33a, 33b, respectively, and the centers of the two head-portion through-holes 22, 22 formed on the distal side (one side in the longitudinal direction) of the head portion 20 are located between the centers of the two first tab through-holes 33a, 33b and on the proximal side (the other side in the longitudinal direction). Specifically, as shown in Fig. 1 , the centers of the two head-portion through-holes 22, 22 formed on the distal side of the head portion 20 are located between the centers of the two first tab through-holes 33a, 33b in the width direction and are located more proximal than the two first tab through-holes 33a, 33b in the longitudinal direction. This allows the distance between the two first-type tabs 30a, 30b to be increased, increasing the degree of freedom in the shape of the first tab main bodies 31a, 31b. Also, the workability in bending and deforming the first-type tabs 30a, 30b (first connection portions 32a, 32b) is improved.

[0026] In the bone plate 1 of this embodiment, in the state before deformation of the first connection portions 32a, 32b (the state shown in Figure 1), the axis extending toward the bone of the first tab through hole 33b of one of the two first type tabs 30a, 30b (here, the first type tab 30b provided on the right side in Figure 1) passes between the axes extending toward the bone of the two head portion through holes 22, 22 formed on the distal side (one side in the longitudinal direction) of the head portion 20. Specifically, in the longitudinal direction, as shown in Fig. 3, the axis P1 extending toward the bone side of the first tab through-hole 33b is inclined toward the proximal side (the lower side in Fig. 3), and the axes Ph, Ph extending toward the bone side of the two head through-holes 22, 22 formed on the distal side of the head portion 20 (the axes Ph, Ph are substantially overlapping in Fig. 3, so only the axis Ph on the near side in Fig. 3 is shown) are inclined toward the distal side (the upper side in Fig. 3). Furthermore, in the width direction, as shown in Fig. 4, the axis P1 extending toward the bone side of the first tab through-hole 33b is inclined toward the left, and the axes Ph, Ph extending toward the bone side of the two head through-holes 22, 22 formed on the distal side of the head portion 20 are inclined toward the right. Therefore, the axis P1 extending toward the bone side of the first tab through hole 33b passes between the axes Ph, Ph extending toward the bone side of the two head through holes 22, 22 formed on the distal side of the head portion 20. This increases the likelihood of avoiding interference with the bone screw 7 to be inserted into the head through hole 22, even when inserting the bone screw 7 into the first tab through hole 32b of the first type tab 30b depending on the condition of the fractured portion (in treating a fracture of the distal tibia, priority is given to inserting the bone screw 7 into the head through hole 22 of the head portion 20). Furthermore, it becomes possible to use a longer bone screw 7 for the first type tab 30b (first tab through hole 32b), thereby expanding the options for more appropriate treatment of the fractured portion.

[0027] A second-type tab 40 is provided on the side (left portion in FIG. 1 ) of the multiple first-type tabs 30 (30a, 30b). More specifically, in this embodiment, a notch 26 is formed in the side (left portion in FIG. 1 ) of the distal portion of the head portion 20, and the second-type tab 40 is provided to extend from the end surface exposed on the distal side of the notch 26. As a result, the second-type tab 40 is provided so as not to protrude distally beyond the first-type tabs 30 (30a, 30b). The second-type tab 40 includes a second connecting portion 42 that is bendable and twistable, and is provided so as to extend outward (distal and lateral in this case) from the head portion 20 via the second connecting portion 42. Before deformation, the second-type tab 40 preferably protrudes outward (laterally) beyond the side end (left end in FIG. 1 ) of the head portion 20. The portion of the second type tab 40 on the outer side of the second connection portion 42 (the portion on the opposite side from the head portion 20) forms a second tab main body portion 41.

[0028] The cross-sectional area of ​​the second connection portion 42 is smaller than the cross-sectional area of ​​the second tab main body portion 41. More specifically, as shown in FIGS. 1 and 8, the second connection portion 42 has a narrower width (w2) and a thinner thickness (t2) than the second tab main body portion 41. In other words, in the second type tab 40, the second connection portion 42 has a lower rigidity than the second tab main body portion 41. Furthermore, the second connection portion 42 has a smaller cross-sectional area than the first connection portions 32 (32a, 32b). In this embodiment, the width (w2) of the second connection portion 42 is narrower than the width (w1) of the first connection portions 32 (32a, 32b), and the thickness (t2) of the second connection portion 42 is thinner than the thickness (t1) of the first connection portions 32 (32a, 32b). As a result, the second type tab 40 is capable of bending deformation in the upper or lower direction of the plate body 10 and the head 20 at the second connection portion 42, and is also capable of twisting deformation around an axis in the extension direction. The width w2 of the second connection portion 42 (approximately 2.1 to 2.3 mm in this embodiment) is preferably larger than the thickness t2 of the second connection portion 42 (approximately 1.55 to 1.65 mm in this embodiment), and the ratio of the width w2 to the thickness t2 (w2 / t2) is preferably in the range of 1.2 to 1.5. This range improves workability when deforming (especially twisting deformation) the second connection portion 42 and prevents damage to the second connection portion 42. The ratio of the width w2 to the thickness t2 (w2 / t2) of the second connection portion 42 is preferably smaller than the ratio of the width w1 to the thickness t1 (w1 / t1) of the first connection portions 32a and 32b. This clarifies the difference between the first connecting portions 32a, 32b, which are bendable, and the second connecting portion 42, which is bendable and twistable, making it easier for the surgeon to perform surgery. It is preferable to appropriately set the cross-sectional area of ​​the second connecting portion 42 so that it is smaller than the cross-sectional area of ​​the first connecting portion. If the cross-sectional area of ​​the second connecting portion 42 is too large, there is a risk that the entire second type tab 40 will deform before the second connecting portion 42 deforms (especially twists), while if the cross-sectional area is too small, there is a risk that the second connecting portion 42 will be excessively deformed or even break.

[0029] The second tab main body 41 is located on the distal side of the second type tab 40 (the side in the extending direction of the second type tab 40). In this embodiment, as shown in Fig. 1, the second tab main body 41 of the second type tab 40 has a substantially circular shape. This makes it difficult for the outer shape of the second type tab 40 to protrude even when the second connecting portion 42 is deformed, thereby reducing contact between the bone plate 1 including the second type tab 40 and the skin, etc.

[0030] The second tab main body 41 of the second type tab 40 has a second tab through-hole 43. In this embodiment, the second tab through-hole 43 has the same diameter as the head portion through-hole 22 (and the first tab through-holes 33a, 33b) (the pilot hole diameter before the formation of the female thread portion is the same). Furthermore, a female thread portion is provided on the inner surface of the second tab through-hole 43 of the second type tab 40, and this female thread portion can be engaged or screwed with a male thread portion provided on the head 72 of a bone screw 7, which will be described later. This makes it possible to apply the same bone screw 7 used for the head portion through-hole 22 (and the first tab through-holes 33a, 33b) to the second tab through-hole 43.

[0031] By appropriately bending and / or twisting the second connection portion 42 of the second type tab 40, the bone plate 1 can be more freely deformed to fit the shape of the bone (especially the epiphysis of a long bone) and the condition of the fractured portion, thereby enabling more appropriate treatment of fractures at the end of a long bone. 10, when the bone plate 1 is used on the distal portion (the anterior lateral surface of the distal tibia; in FIG. 10, the lower side is the distal side) of the tibia 8 (shown by the dashed line in FIG. 10), the second type tab 40 is located at the anterior lateral end of the tibia 8 (the lower right part in FIG. 10), which has a relatively sharply curved outer shape (small radius of curvature). Here, because the second connecting portion 42 of the second type tab 40 is capable of bending and twisting deformation, the bone fragment in that portion can be more appropriately captured by the bone screw 7.

[0032] The multiple tabs of the bone plate 1 of this embodiment include a third type tab 50 provided on the side opposite to the side of the multiple first type tabs 30 (30a, 30b) on which the second type tabs 40 are provided (the right side in Figure 1), and the third type tab 50 includes a third tab main body 51 having a third tab through hole 53 and a third connection part 52 which has a larger cross-sectional area than the second connection part 42 of the second type tab 40 and is bendable and deformable, and is provided so as to extend outward from the head part 20 and in a direction different from the first type tabs 30 (30a, 30b) by the third connection part 52, and the third tab through hole 53 has the same diameter as the head part through hole 22.

[0033] More specifically, the third type tab 50 is provided on a side of the plurality of first type tabs 30 (30a, 30b), opposite the side of the plurality of first type tabs 30 (30a, 30b) on which the second type tab 40 is provided (the right side in FIG. 1 ). In this embodiment, the third type tab 50 is provided so as to extend outward from a side surface of the distal portion of the head portion 20 (the right side in FIG. 1 ). The third type tab 50 is provided so as to extend in one width direction (the right direction in FIG. 1 ), which is different from the plurality of first type tabs 30 (30a, 30b) that extend in the distal direction. The third type tab 50 includes a bendable third connecting portion 52, and is provided so as to extend outward from the head portion 20 via the third connecting portion 52. The portion of the third type tab 50 outward of the third connecting portion 52 (the portion opposite the head portion 20) forms a third tab main body portion 51.

[0034] The cross-sectional area of ​​the third connection portion 52 is smaller than the cross-sectional area of ​​the third tab main body portion 51. More specifically, as shown in FIGS. 1 and 9, the third connection portion 52 has a narrower width (w3) than the third tab main body portion 51. In other words, in the third type tab 50, the third connection portion 52 has a lower rigidity than the third tab main body portion 51. This allows the third type tab 50 to bend and deform in the third connection portion 52 toward the upper or lower surface of the plate main body portion 10 and the head portion 20. Note that the thickness (t3) of the third connection portion 52 may be smaller than the thickness of the third tab main body portion 51.

[0035] It is desirable that the third connecting portion 52 bendable but not twistable (i.e., when a doctor performs surgery, the third connecting portion 52 cannot be twisted substantially around the axis in the extending direction of the third type tab 50). For example, the width w3 of the third connecting portion 52 (approximately 2.4 to 2.6 mm in this embodiment) is preferably larger than the thickness t3 of the third connecting portion 52 (approximately 1.42 to 1.52 mm in this embodiment), and the ratio of the width w3 to the thickness t3 (w3 / t3) is preferably in the range of 1.5 to 2.0. Furthermore, the ratio of the width w3 to the thickness t3 of the third connecting portion 52 (w3 / t3) is preferably larger than the ratio of the width w2 to the thickness t2 of the second connecting portion 42 (w2 / t2). This allows the third connecting portion 52 to bendable but not substantially twistable relative to the second connecting portion 42.

[0036] In this embodiment, the third type tab 50 is provided so as to extend in one width direction (to the right in FIG. 1) from the side surface (the right surface in FIG. 1) of the distal portion of the head portion 20, and is provided with a bendable third connection portion 52. This allows for relatively free design of the shape of the head portion 20. Specifically, by bending the third type tab 50 upward or downward, interference between the side edge of the bone plate 1 and the bone can be avoided.

[0037] The third tab main body 51 is located on the outer side of the third type tab 50 (the extension direction side of the third type tab 50). In this embodiment, as shown in Fig. 1, the third tab main body 51 of the third type tab 50 has a substantially circular shape. This makes it difficult for the outer shape of the third connection portion 52 to protrude, thereby reducing contact between the bone plate 1 including the third type tab 50 and the skin, etc.

[0038] The third tab main body 51 of the third type tab 50 has a third tab through-hole 53. In this embodiment, the third tab through-hole 53 has the same diameter (the same pilot hole diameter before forming the female thread portion) as the head portion through-hole 22 (as well as the first tab through-holes 33a, 33b, and second tab through-hole 42). Furthermore, a female thread portion is provided on the inner surface of the third tab through-hole 53 of the third type tab 50, and this female thread portion can be engaged or screwed with a male thread portion provided on the head 72 of a bone screw 7, which will be described later. This makes it possible to apply the same bone screw 7 used for the head portion through-hole 22 (as well as the first tab through-holes 33a, 33b, and second tab through-hole 42) to the third tab through-hole 53.

[0039] The material for forming the bone plate 1 is preferably a titanium alloy (specifically, Ti-6Al-4V of JIST7401-2, Ti-6Al-4V ELI of ASTM F-136), pure titanium (specifically, JIST7401-1), stainless steel (specifically, SUS304 and SUS316 of JIS G4303), or the like.

[0040] FIG. 11 shows an example of a bone screw 7 used with a bone plate 1 in treating a fracture of the end of a long bone. As shown in FIG. 11, the bone screw 7 has a shank 71 and a head 72. The shank 71 has a male thread on its outer surface and is capable of passing through the through-holes of the bone plate 1 (the head through-hole 22, the first tab through-holes 33a and 33b, the second tab through-hole 42, and the third tab through-hole 52). The shank 71 is also capable of entering the bone (a pilot hole formed in the target bone).

[0041] The head 72 of the bone screw 7 has a recess (not shown) on the top surface for connecting a turning jig (for example, a screwdriver). The recess is formed in a shape corresponding to the shape of the tip of the turning jig.

[0042] The head 72 of the bone screw 7 has a larger diameter than the shank 71 and is provided with a male thread on its outer surface. The male thread consists of a helical thread (thread) that rotates clockwise in the axial direction in a plan view (when viewed from the head 72 side in the axial direction of the bone screw 7) and forms a so-called right-handed screw. The male thread can be engaged or screwed into the female thread formed on the inner surface of the through-holes (head through-hole 22, first tab through-holes 33a, 33b, second tab through-hole 42, and third tab through-hole 52) of the bone plate 1.

[0043] As with the bone plate 1, the material for forming the bone screw 7 is preferably a titanium alloy (specifically, Ti-6Al-4V of JIST7401-2, Ti-6Al-4V ELI of ASTM F-136), pure titanium (specifically, JIST7401-1), stainless steel (specifically, SUS304 and SUS316 of JIS G4303), etc.

[0044] The bone plate of the present invention is not limited to the above-described embodiment. For example, the first type tab may not have a first tab through-hole. In that case, the first type tab (first tab main body) functions to appropriately support the fractured portion (bone or fracture fragments). Also, the third type tab may not be provided. In that case, another second type tab may be provided on the side opposite to the side of the multiple first type tabs on which the second type tabs are provided in the above-described embodiment. Furthermore, the shapes of the first, second, and third type tabs in the bone plate (e.g., their locations relative to the head portion, the outer shapes of the first, second, and third tab main bodies, and the cross-sectional shapes of the first, second, and third connecting portions) and the shapes of the plate main body and head are not limited to those of the above-described embodiments. For example, as in the bone plate 1a shown in Fig. 12, the longitudinal dimension of the plate main body 10 may be increased depending on the shape of the long bone to be treated with the bone plate and the manner in which the bone plate is fixed to the long bone. The bone plate of the present invention can be used for the bone plate shown in the above-mentioned embodiment (an anterolateral tibial plate used for the anterolateral surface of the distal tibia), as well as for the long bones constituting the lower limbs (fibula, femur, metatarsals, phalanges, etc.) and the long bones constituting the upper limbs (humerus, radius, ulna, metacarpals, phalanges, clavicle, etc.). The long bones targeted by the bone plate of the present invention broadly include human bones that are long (longer than wide). Furthermore, the bone plate of the present invention is used to treat fractures of the end of a long bone, and the end of the long bone to be treated with the bone plate primarily refers to the epiphyseal portion of the long bone, but may also include a part of the metaphysis or a part of the diaphysis in addition to the epiphyseal portion. [Explanation of symbols]

[0045] 1,1a Bone Plate 10 Plate body 20 Head 22 Head through-hole 23 Recess 26 Notch 30, 30a, 30b 1st type tab 31, 31a, 31b First tab body 32, 32a, 32b First connection part 33, 33a, 33b First tab through hole 40 Second Type Tab 41 Second tab body 42 Second connection part 43 Second tab through hole 50 Third Type Tab 51 Third tab main body 52 Third connection part 53 Third tab through hole 7 Bone Screws 71 Shaft 72 Head

Claims

1. A bone plate used to treat fractures of the end of a long bone, comprising: a plate body portion extending in a longitudinal direction; a head portion located on one side of the plate body portion in the longitudinal direction and wider than the portion of the plate body portion on the one side in the longitudinal direction; and a plurality of tabs provided on a peripheral edge of the head portion, the head portion has a plurality of head portion through-holes into which shanks of bone screws can be inserted; the plurality of tabs include a plurality of first type tabs arranged in parallel in a width direction of the head portion and a plurality of second type tabs located on either side of the plurality of first type tabs, the first type tab includes a first tab main body and a first connection portion that is bendable but not twistable, and is provided so as to extend from one end of the head portion in the longitudinal direction to one side by the first connection portion, a cross-sectional area of ​​the first connection portion is smaller than a cross-sectional area of ​​the first tab main body, and a width w1 of the first connection portion is larger than a thickness t1 of the first connection portion, the second type tab comprises a second tab main body portion having a second tab through-hole and a second connecting portion that is bendable and twistable, and extends outward from the head portion by the second connecting portion, a cross-sectional area of ​​the second connecting portion is smaller than a cross-sectional area of ​​the second tab main body portion, a width w2 of the second connecting portion is larger than a thickness t2 of the second connecting portion, and a value of a ratio (w2 / t2) of the width w2 of the second connecting portion to the thickness t2 of the second connecting portion is smaller than a value of a ratio (w1 / t1) of the width w1 of the first connecting portion to the thickness t1 of the first connecting portion, and the bone plate is made of a titanium alloy, pure titanium, or stainless steel.

2. the first tab body portion of the first type tab has a first tab through-hole; The bone plate according to claim 1 , wherein the first tab through-hole and the second tab through-hole have the same diameter as the head portion through-hole.

3. the plurality of tabs includes a third type tab provided on a side opposite to a side on which the plurality of first type tabs are provided with the second type tab, the third type tab includes a third tab main body portion having a third tab through-hole and a third connection portion that is bendable but not twistable, and is provided so as to extend outward from the head portion in a direction different from that of the first type tab by the third connection portion, the cross-sectional area of ​​the third connection portion is smaller than the cross-sectional area of ​​the third tab main body portion, the width w3 of the third connection portion is larger than the thickness t3 of the third connection portion, and the ratio (w3 / t3) of the width w3 of the third connection portion to the thickness t3 of the third connection portion is larger than the value of the ratio (w2 / t2) of the width w2 of the second connection portion to the thickness t2 of the second connection portion, 3. The bone plate according to claim 1, wherein the third tab through-hole has the same diameter as the head through-hole.

4. 4. The bone plate according to claim 1, wherein two first-type tabs are provided, each of the first-type tab main bodies has a first-type tab through-hole, and the centers of the two head-portion through-holes formed on one side of the head portion in the longitudinal direction are positioned between the centers of the two first-type tab through-holes and on the other side of the longitudinal direction.

5. 5. The bone plate according to claim 4, wherein, in a state before deformation of the first connection portion, an axis extending toward the bone of the first tab through hole of one of the two first type tabs passes between axes extending toward the bone of two head portion through holes formed on one side in the longitudinal direction in the head portion.

6. 6. The bone plate according to claim 1, wherein the first tab body of the first type tab has a trapezoidal shape that widens toward one side in the longitudinal direction.

7. 7. The bone plate according to claim 1, wherein the first tab body portion of the first type tab has a first tab through hole, and the projected area of ​​the outer shape of the first tab body portion is four times or more the projected area of ​​the first tab through hole when viewed in the axial direction of the first tab through hole.

8. 8. The bone plate according to claim 1, wherein the bone plate is used for treating a fracture of the distal tibia.

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