JP2020175197A - Plate for fixing bone - Google Patents

Abstract

To provide a plate for fixing at least partially separated bone.SOLUTION: A plate of the present invention is a plate for fixing a bone including a bone defective part, a proximal bone part, and a distal bone part. The plate of the present invention comprises: a first end corresponding to the proximal bone part; a second end corresponding to the distal bone part; and a first curved surface along an approximately circumferential direction of the bone. The plate has a shape along a surface of a tibial crest of a tibia. The plate of the present invention is mainly for high tibial osteotomy and may be mounted on an inside tibial crest of the tibia.SELECTED DRAWING: Figure 1A

Description

The present invention relates to plates for fixing bones that are at least partially separated.

Conventionally, high tibial osteotomy (HTO) using a substantially flat T-shaped plate has been known (see, for example, Patent Document 1).

Special Table No. 2017-511194

The present inventors have found a plate having excellent fixation, less burden on bone, and a shape (typically having a curved surface) capable of dispersing the stress generated in the plate.

Since the shape of the plate created by the present inventors has a shape that matches the medial tibial crest, in the osteotomy using the plate of the present invention, the plate has an osteotomy step and an appropriate insert. After the step of insertion, it is applied to the medial tibial crest and the separated bone is fixed. Compared to the conventional T-shaped plate, which is applied to the proximal anterior medial aspect of the tibia where a relatively wide plane is continuous due to shape restrictions, the support strength is dramatically strengthened and the postoperative course is also improved. It is good.

The present invention provides, for example,:
(Item 1)
A plate for fixing bones that are at least partially separated, said bone having a bone defect, a proximal bone and a distal bone.
The first end corresponding to the proximal bone and
The second end corresponding to the distal bone and
It is provided with a first curved surface along the substantially circumferential direction of the bone.
The plate is a plate having a shape along the surface of the convex surface of the bone.
(Item 2)
The plate of item 1, wherein the convex surface of the bone is the medial tibial crest of the tibia.
(Item 3)
Item 1 or 2 that the first curved surface has at least a first curvature at the first end and a second curvature at the second end that is greater than the first curvature. The plate described in.
(Item 4)
The plate comprises at least one fixation portion for fixing the plate to the bone, and the at least one fixation portion includes a first fixation portion arranged in close proximity to the first end portion. The first fixing portion and / or the second fixing portion is arranged along the substantially circumferential direction, including a second fixing portion arranged in the vicinity of the second end portion. The plate according to any one of items 1 to 3.
(Item 5)
The plate according to item 4, wherein the at least one fixing portion includes a hole for inserting a bone screw.
(Item 6)
The plate according to any one of items 1 to 5, wherein the plate has a shape extending in a substantially circumferential direction in a fan shape from the second end portion toward the first end portion.
(Item 7)
A kit for fixing bones that are at least partially separated, said kit.
The plate according to any one of items 1 to 6 and
With at least one bone screw for fixing the plate to the bone,
A kit comprising the plate and a second plate having a mirror image-like shape.
(Item 8)
Item 7. The kit according to item 7 for high tibial osteotomy.
(Item 9)
A set of plates according to any one of items 1 to 6.
The set of plates comprises at least a first plate and a second plate.
The first plate has a shape along the convex surface of the first bone.
The second plate is a set of plates having a shape along the convex surface of the second bone, which is different from the first bone.
(Item 10)
The set of plates according to item 9, wherein the set of plates comprises different plates in at least one parameter of size, curvature, thickness, and number of holes.

According to the present invention, it is possible to provide plates and kits for fixing bones that are at least partially separated. In one embodiment, the shape of the plate created by the present inventors has a shape that matches the medial tibial crest. Therefore, in the osteotomy using the plate of the present invention, the plate is subjected to the osteotomy step. After the step of inserting the appropriate insert, it is applied to the medial tibial crest and the separated bone is fixed. Compared to the conventional T-shaped plate, which is applied to the proximal anterior medial aspect of the tibia where a relatively wide plane is continuous due to shape restrictions, the support strength is dramatically strengthened and the postoperative course is also improved. It is good.

A medial perspective view showing an example of the form of a plate of the present invention for fixing bones that are at least partially separated. A lateral perspective view showing an example of the form of a plate of the present invention for fixing bones that are at least partially separated. FIG. 5 is a plan view showing an example of the form of the plate of the present invention for fixing bones that are at least partially separated. FIG. 5 is a side view showing an example of the form of the plate of the present invention for fixing bones that are at least partially separated. The figure which shows an example of the state after the high tibial osteotomy in which the plate 100 was fixed to the tibia. Sectional view of the tibia including the medial tibial crest. The figure which shows the deformation example of the shape of a plate. The figure which shows an example of the appearance of the plate 100. The figure which shows the comparison (surface only) of the stress generated in the plate when the compressive force is applied to the knee joint with the plate attached to the wedge-shaped notch (bone defect part) of the tibia. The figure which shows the comparison (front surface and back surface) of the stress generated in the plate when the compression force is applied to the knee joint with the plate attached to the wedge-shaped notch (bone defect part) of the tibia. The figure which shows the comparison of the stress generated on the surface of a plate and a bone when a turning force is applied to a knee joint with a plate attached to a wedge-shaped notch (bone defect part) of a tibia. The figure which shows the example which applied the plate 100 to the fracture treatment of the proximal part of the knee joint surface on the tibial side.

Hereinafter, the present invention will be described with reference to an example of the best mode. Throughout the specification, it should be understood that the singular representation also includes its plural concept, unless otherwise stated. Therefore, it should be understood that singular articles (eg, "a", "an", "the", etc. in English) also include the concept of their plural, unless otherwise noted. It should also be understood that the terms used herein are used in the meaning commonly used in the art unless otherwise noted. Thus, unless otherwise defined, all terminology and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs. In the event of inconsistency, the description herein takes precedence (including definitions).

Hereinafter, terms used in the present specification are defined.

With respect to bone, the term "medial" refers to the side of the human body closer to the longitudinal central axis (spine).

With respect to bone, the term "outer" refers to the side of the human body farther from the longitudinal central axis (spine).

The term "proximal" refers to a portion of the limb that is closer to the trunk and a plate that is located closer to the trunk of the limb when worn.

The term "distal" refers to a portion of the limb that is farther from the trunk and a plate that is located farther from the trunk of the limb when worn.

The term "proximal bone portion of bone defect" refers to a bone portion adjacent to the bone defect portion and proximal to the bone defect portion.

The term "distal bone portion of bone defect" refers to a bone portion adjacent to the bone defect portion and distal to the bone defect portion.

The term "metal biocompatible material" refers to a metal material having biocompatibility.

The term "high tibial osteotomy" (HTO) refers to surgery to normalize the alignment of the femur or tibia by making an incision in the proximal tibia. Normalizing the alignment of the femur or tibia includes, for example, changing the lower limbs from the O-leg state to the slightly X-leg state.

The plate of the present invention has a shape along the convex surface of the bone (eg, the medial tibial crest). The medial tibial ridge usually contains the portion of the cut surface of the osteotomy that has the greatest distance.

The proximal anterior medial aspect of the tibia is the site that extends from the central part of the tibia to the relatively flat surface of the anterior medial proximal part, unlike the portion of the cut surface of the osteotomy that has the greatest distance. The plates of the invention are configured to be capable of being placed to support a portion of the proximal anterior medial aspect of the tibia, a portion of the posterior surface of the tibia, and the medial tibial ridge between them. .. The plate of the present invention differs from the conventional plate in this respect because the conventional typical plate is arranged so as to support only the proximal anterior medial aspect of the tibia.

The "height" of the plate is the maximum axial length of the plate.

The term "about" refers to ± 10% of the value indicated, unless otherwise stated.

The phrase "at least partially separated bone" refers to any condition of bone that is not originally separated and that is separated from each other, including bone that is intentionally separated (eg, in surgery). Also includes bones that are unintentionally separated (eg, due to an accident or congenitally).

A preferred embodiment of the present invention will be described below. The embodiments provided below are provided for a better understanding of the invention and the scope of the invention should not be limited to the following description. Therefore, it is clear that a person skilled in the art can appropriately make modifications within the scope of the present invention in consideration of the description in the present specification. In addition, the following embodiments of the present invention may be used alone or in combination thereof.

1. 1. Plates for Fixing At least Partially Separated Bones The present invention relates to plates for fixing at least partially separated bones. The bones that are at least partially separated in the present invention may be bones that are intentionally separated by surgery, or may be unintentionally separated by congenital or accident. Typically, the plate of the present invention is intended for bone that is partially separated by intentionally creating a defect in the bone by surgery, and is a bone portion proximal to the bone defect. It may support from the bone defect to the distal bone. Typically, the plates of the invention can be for high tibial osteotomy (HTO).

FIG. 1A is an internal perspective view showing an example of the form of the plate of the present invention for fixing bones that are at least partially separated. FIG. 1B is an external perspective view showing an example of the form of the plate of the present invention for fixing bones that are at least partially separated. FIG. 1C is a plan view showing an example of the form of the plate of the present invention for fixing bones that are at least partially separated. FIG. 1D is a side view showing an example of the form of the plate of the present invention for fixing bones that are at least partially separated.

As illustrated in FIGS. 1A-1D, the plate 100 has end 101 (ie, the proximal end of the plate 100) and end 102 (ie, the distal end of the plate 100) along the approximately axial direction of the bone. ) And the curved surface 103. The end 101 side of the plate 100 supports the proximal bone of the bone defect. The portion that supports the proximal bone portion of the bone defect is referred to as the proximal portion of the plate 100 (proximal portion 105 in FIG. 1A). The end 102 side of the plate 100 supports the distal bone of the bone defect. The portion that supports the distal bone portion of the bone defect is referred to as the distal portion of the plate 100 (distal portion 106 in FIG. 1A).

The curved surface 103 is curved so as to have a first curvature in the circumferential direction at the end 101, and is curved so as to have a second curvature in the circumferential direction at the end 102. The curved surface 103 may be configured such that the curvature changes in a complex manner from the end 101 to the end 102. The curved surface 103 may be configured such that the curvature changes continuously from the end 101 to the end 102. The first radius of curvature of the curved surface 103 is often different from, but may be the same as, the second radius of curvature of the curved surface 103. Typically, the second radius of curvature is smaller than the first radius of curvature, preferably the first radius of curvature is about 1.3-5 times the second radius of curvature.

The radius of curvature of the first curvature of the curved surface 103 is about 1 to 250 mm, preferably about 10 to 40 mm. This makes it possible to reduce the gap between the bone surface with which the plate 100 contacts and the plate 100, and to increase the fixing force. Since the measured value of the radius of curvature of the Japanese tibia adjacent to the end 101 of the plate 100 when fixed is about 22 to 26 mm, the radius of curvature of the first curvature of the curved surface 103 is about 20 to 30 mm. More preferably. The value of the radius of curvature of the first curvature may be the average value of the radius of curvature of the entire end 101.

The radius of curvature of the second curvature of the curved surface 103 is about 1 to 100 mm, preferably about 5 to 40 mm. This makes it possible to reduce the gap between the bone surface with which the plate 100 contacts and the plate 100, and to increase the fixing force. Since the measured value of the radius of curvature of the Japanese tibia adjacent to the end 102 of the plate 100 when fixed is about 9.5 to 12 mm, the radius of curvature of the second curvature of the curved surface 103 is about 8 to. It is more preferably 15 mm. The value of the radius of curvature of the second curvature may be the average value of the radius of curvature of the entire end 102.

The plate 100 has a first length in the substantially circumferential direction at the end 101 and a second length in the substantially circumferential direction at the end 102. The second length may be different from or the same as the first length. Preferably, the second length of the end 102 is smaller than, but not limited to, the first length of the end 101. As a result, the plate 100 has a shape that expands in the substantially circumferential direction in a fan shape from the end 102 to the end 101. Therefore, the plate 100 can be fixed so as to wrap around the portion of the bone to be fixed. The "shape that expands in the substantially circumferential direction in a fan shape" is not only a shape that expands in a substantially fan shape in a substantially circumferential direction, but also that the edge portion does not slightly expand from the end 102 to the end 101. However, when about 70% or more of both axial edges extend from the end 102 to the end 101 as a whole, it is referred to as "a fan-shaped extension in the substantially circumferential direction" in the present specification. Note (see FIGS. 1A and 1B). When the second length is the same as the first length, the plate 100 has a shape formed by bending a rectangular flat plate, and the silhouette in front view is a fan shape.

The plate 100 has a shape along the bone surface including the medial tibial crest. The front view shape of the plate 100 can take, for example, various shapes shown below (for example, an inverted trapezoidal shape, a rectangular shape, and a shape having a portion protruding from the side side). That is, the front view shape of the plate 100 is arbitrarily redesigned according to the position and number of screws for fixing the plate 100 to the bone, and / or the range in which the plate 100 should support the bone surface. It is possible.

By having a first curvature and a second curvature as described above, the plate 100 of the present invention has a first curvature on the bone surface proximal to the bone defect at the medial tibial crest of the tibia. The proximal 105 can efficiently support the bone surface distal to the bone defect with the distal 106 having a second curvature. This makes it possible to distribute the load applied to the plate to the proximal and distal parts of the plate without exerting a load on the bone defect. This makes it possible to reduce the risk of deformation and breakage of the plate and burden on the bone.

The surface of the curved surface 103 is not, in detail, a surface close to a flat plate (having a constant curvature) like a conventional plate, but a plurality of small surfaces having various sizes and shapes so as to be continuous over the entire curved surface 103. It may be composed of uneven surfaces. With such a plurality of small curved surfaces, it is possible to achieve a shape that is more fitted to the bone having a complicated three-dimensional shape.

Based on the distribution of curvature and length of the curved surface along the convex surface of the bone (eg, the tibial crest of the tibia), statistical techniques are used to typify the shape of the plate, including the curvature and length of the curved surface. It is possible to do.

As an example of categorizing the shape of the plate, the present inventors have conducted extensive studies on the first curvature and the second curvature of the curved surface 103 along the convex surface of the bone (for example, the tibial ridge of the tibia). , A bimodal normal distribution curve (that is, a normal distribution curve having two maximum values) was statistically obtained with the curvature of the curved surface and the number of patients as axes. The first maximum value corresponds to a bone having a small radius of curvature of the convex surface of the bone (that is, a sharp-shaped bone), and the second maximum value corresponds to a bone having a large radius of curvature of the convex surface of the bone (that is, a round shape). Corresponds to the bone). Based on this result, the present inventors prepared four types of general-purpose models of the plate 100 shown below. These four types of general-purpose models can have a symmetrical shape (that is, a mirror surface structure having the same shape on the left and right) with respect to the axial central axis of the plate. By utilizing these four types of general-purpose models, it is possible to apply the plate 100 of the present invention to most patients.
-First type: A plate having a shape along the convex surface of the bone whose radius of curvature is the first maximum value-Second type: A plate having a shape mirror image of the first type plate-Third Type: A plate having a shape along the convex surface of the bone whose radius of curvature is the second maximum value ・ Fourth type: A plate having a shape mirror image of the second type plate

The combination of the first type and the third type, or the combination of the second type and the fourth type may be used as a kit. Alternatively, a combination of the first type and the second type, or a combination of the third type and the fourth type may be used as a kit so as to be used when operating both feet at the same time. .. It should be noted that each of these combinations may include a set of a plurality of sizes.

As described above, the curved surface 103 has a first curvature and a second curvature in the circumferential direction, but may or may not be curved in the axial direction. For example, in one embodiment, the curved surface 103 further has a third curvature curvature between the proximal 105 and the distal 106 to support the bone defect proximal bone of the bone. You may. Typically, the curved surface 103 has a curvature of a third curvature in the vicinity of the proximal portion 105 so that it is convex inward when attached to the bone. The radius of curvature of the third curvature is about 1 to 160 mm, preferably about 10 to 40 mm. This makes it possible to effectively receive the load of the proximal bone of the bone defect at the proximal portion of the plate, disperse the stress, and / or increase the fixation force. However, the proximal 105 does not necessarily have to be curved and the proximal 105 may be flat. The value of the radius of curvature of the third curvature may be the average value of the radius of curvature in the vicinity of the proximal portion 105.

The curved surface 103 further has a third curvature curvature between the proximal 105 and the distal 106, followed by a fourth curvature curvature to support the bone defect distal bone. You may. Typically, in the vicinity of the distal portion 106 of the third curvature, it has an inwardly convex curvature when attached to the bone. The curved surface 103 may have an outwardly convex curve at the connection between the third curve and the fourth curve. The radius of curvature of the fourth curvature is about 5-60 mm, preferably about 14-35 mm. This makes it possible to efficiently receive the load from the proximal portion in the distal portion, disperse the stress, and / or increase the fixing force. However, the distal 106 may not necessarily be curved and the distal 106 may be flat. The value of the radius of curvature of the fourth curvature may be the average value of the radius of curvature between the proximal portion 105 and the distal portion 106 (typically, in the vicinity of the distal portion 106).

Further, in the curved surface 103, an intermediate portion may be provided between the portion having the third curvature and the portion having the fourth curvature. Typically, the middle part can be the part that traverses the bone defect. The intermediate portion is formed according to the third curvature and the fourth curvature, and is often convex in design, but may be concave or flat, which is the original function of the plate 100. (That is, the fixing force of the plate 100) is not lost.

Further, the curved surface 103 may be curved so as to further have a fifth curvature (see FIG. 1D) in the vicinity of the end portion 101 to more sufficiently support the bone defect proximal bone portion of the bone. The radius of curvature of the fifth curvature of the curved surface 104 is about 5 to 50 mm, preferably about 10 to 30 mm. Thereby, it is possible to further strengthen the support of the bone defect proximal bone portion of the bone by the plate 100, and thus it is possible to enhance the stability of the plate 100.

The plate 100 of the present invention further comprises at least one fixation portion for fixing the plate 100 to the bone. The fixation portion of the plate 100 is a surface that comes into contact with the bone, and the plate 100 can be fixed to the bone using, for example, a bone screw or a titanium screw. In addition, at least one fixing portion of the plate 100 of the present invention includes a hole for inserting a bone screw or a titanium screw. By inserting a bone screw or a titanium screw into the bone through the hole, the plate 100 can be fixed to the bone at at least one fixing part. In the present specification, the “bone screw” means a screw made of a biocompatible material and having a thread.

The plate 100 may further comprise a fixed portion at a proximal portion 105 located in close proximity to the end 101 and a distal portion 106 located close to the end 102, respectively. In the example shown in FIGS. 1A-1D, the fixation is a plurality of holes 107 for inserting a plurality of bone screws, respectively, located in the proximal portion 105 and the distal portion 106 of the plate 100. In the example shown in FIGS. 1A to 1D, the holes 107 in the proximal portion 105 and the distal portion 106 are respectively arranged along the substantially circumferential direction. As a result, the screw insertion position is not limited as compared with the conventional plate having a substantially flat surface, so that a sufficient number of holes necessary for fixing can be arranged. As a result, it is not necessary to insert a bone screw around the bone defect to be protected, and the burden on the bone can be reduced. Further, in the plate 100 of the present invention, since the rigidity of the curved plate is higher than that of the conventional plate, sufficient fixing strength can be exhibited by using a smaller number of holes and bone screws.

Further, in the plate 100 of the present invention, since the plurality of holes 107 are provided in the three-dimensional three-dimensional shape provided with the curved surface 103, the plurality of bone screws can be formed into the bone through the plurality of holes 107 of the plate 100. It is inserted in a direction (ie, so that the insertion directions of the plurality of bone screws are not in the same plane), whereby the plate 100 is fixed to the bone. This also contributes to the use of a smaller number of holes and bone screws to provide sufficient fixation strength. As described above, it is desirable that the plurality of holes are configured so that the directions of the plurality of holes are not present in the same plane in order to increase the fixing force. Also, the length of each of the plurality of bone threads is determined by whether or not the cortical bone facing the plurality of holes 107 and the bone screw contact (or penetrate) (that is, the length of the bone screw). Is greater than the distance from the hole to the opposing cortical bone) and / or the degree of penetration when the cortical bone facing the multiple holes 107 and the bone screw penetrate). You may. The lengths of the plurality of bone screws may be the same, at least a part of them may be the same, or all of them may be different.

Also, the diameter and number of holes can vary, for example, depending on geometric or clinical conditions. There are at least two holes in each of the proximal and distal regions, for example. Alternatively, combinations of (number of holes in the proximal part, number of holes in the distal part) are, for example, (2,2), (3,3), (4,4), (3,2), ( 4, 2), (4, 3), etc., but not limited to these. Preferably, the number of holes in the proximal region is greater than the number of holes in the distal region. The diameter of the hole is preferably about 3 to 10 mm, more preferably about 5 to 7 mm.

The plate 100 of the present invention is configured to direct the bone screw in a specific direction so that the bone screw can effectively exert a fixing force. The specific direction in which the bone screw faces may differ depending on the attachment position of the bone screw. Further, the plate 100 of the present invention is configured so that it can be integrated with the bone screw via a locking mechanism (not shown) for fixing the bone screw to the plate 100.

The plate 100 of the present invention has a smaller axial length (for example, about one-third of the axial length of the conventional plate) as compared with a substantially flat conventional plate (T-shaped plate). It can be fixed to the bone. This is because, as described above, the plate 100 has a fan-shaped shape that expands in the substantially circumferential direction so as to wrap the portion to be fixed of the bone.

The height of the plate 100 is about 30 to 70 mm, preferably about 30 to 60 mm, and more preferably about 40 to 50 mm. (Height of plate 100) = (Height of bone defect) + (Height of plate portion supporting proximal bone defect) + (Height of plate portion supporting distal bone defect) The height of the bone defect is typically about 10 to 20 mm, and the height of the plate portion that supports the proximal bone of the bone defect and the distal bone of the bone defect is about 10. It can be ~ 25 mm, or about 10-20 mm, preferably about 10-15 mm. Since a plurality of bone screws can be arranged in the circumferential direction near the end 101 and the end 102 of the plate 100, the plate 100 is designed to be shorter in height as compared with the conventional plate. It is possible. This makes it possible to make the incision width and incision length for placing the plate 100 in the bone smaller and less invasive as compared with the conventional T-shaped plate. Further, even when the height of the plate 100 is reduced and the thickness of the plate 100 in the radial direction is made thinner, the plurality of bone screws are arranged on the plate 100 in the circumferential direction, so that the plate 100 It is possible to increase the rigidity of the screw and increase the fixing force. When the height of the plate 100 of the present invention is about 30 to 50 mm, it is possible to easily attach the plate 100 to the affected area. The width of the plate 100 in the circumferential direction is at least about 30 mm, preferably about 30 mm so that the rigidity of the plate 100 can be increased and a plurality of bone screws can be arranged on the plate 100 in the same plane in the circumferential direction. , Approximately 40-50 mm. The circumferential width of the plate 100 may be shorter than the height of the plate 100 (the length of the plate 100 forming a rectangle or the length of the plate 100 forming a fan shape), or the height of the plate 100. They may have the same length (the length of the plate 100 forming a square).

The thickness of the plate 100 is determined based on various parameters. Specifically, the radial thickness of the plate 100 is about 1 to 5 mm, preferably about 2 to 3 mm. An example of various parameters is the value of the stress generated in the plate due to the external force acting on the tibia, and the thickness of the plate 100 is determined by using a numerical simulation and the stress value is the threshold value (for example, the plate 100). Allowable strength value of) can be determined to be less than or equal to. Another example of the various parameters is the value of the stress generated in the plate due to the bone screw, and the thickness of the plate 100 can be determined so that the stress due to the bone screw does not deform the plate 100. If the thickness of the plate 100 is too large (for example, larger than 5 mm), the strength of the plate 100 is high, but it is clinically difficult to place it on the patient's bone (for example, the tibia), and the thickness of the plate 100 is high. If is too small (eg, less than 1 mm), it is clinically easier to place on the patient's bone (eg, tibia), while the strength of the plate 100 is low.

The above-mentioned numerical values may be appropriately changed beyond the above-mentioned range depending on mechanical or clinical reasons, or reasons caused by differences in bone morphology depending on gender or race. Therefore, the overall shape, size, various curvatures, number of holes, thickness, etc. of the plate 100 are also based on various parameters (eg, values indicating how much stress generated in the plate is dispersed). , Threshold determination and the like.

The plate of the present invention is preferably made of a metal biocompatible material (eg, made of titanium, titanium alloy, cobalt-chromium alloy), but the present invention is not limited thereto. The material of the plate of the present invention is arbitrary as long as it is a biocompatible material having strength for fixing bone. The plate 100 of the present invention is, for example, a plate used in high tibial osteotomy.

The method for manufacturing the plate 100 is arbitrary. The plate 100 may be manufactured, for example, by using a 3D additive manufacturing method to fit the shape of an individual bone, may be formed by plastic deformation such as plate bending, or may be bent. It may be manufactured by machining finish with a cutting tool (for example, a ball end mill) using a plate-shaped element.

For example, when manufacturing the plate 100 to fit the shape of an individual bone using 3D additive manufacturing, the plate 100 is manufactured, for example, by the following procedure:
Step 1: Take a CT image of the part of the patient's tibia where the wedge-shaped osteotomy is performed.
Step 2: Acquire a three-dimensional image of the patient's tibia based on the captured CT image.
Step 3: On the acquired 3D image, determine the opening angle of the incision in which a normal alignment of the femur or tibia can be obtained by making a wedge-shaped incision in the proximal tibia. After determining the opening angle of the incision, the proximal tibia is maintained in a wedge-shaped incision at the determined opening angle on the three-dimensional image.
Step 4: Create a three-dimensional curved surface that fits the tibial surface across the wedge-shaped incision.
Step 5: Generate a three-dimensional image of the plate 100 based on the generated three-dimensional curved surface. Specifically, a thickness (for example, 3 mm is described below) is added to the generated three-dimensional curved surface, and on the three-dimensional curved surface having a thickness of 3 mm, the proximal tibia and the distal tibia are separated from each other. The position of the hole to be arranged is determined, and the hole is provided at the determined position on the three-dimensional curved surface having a thickness of 3 mm.
Step 6: Convert the generated 3D image of the plate 100 into an STL file.
Step 7: Based on the converted STL file, a titanium alloy plate 100 is manufactured using a laminated molding apparatus.
Step 8: The manufactured plate 100 is polished using a polishing device so as to remove the incompletely melted titanium particles adhering to the surface of the manufactured plate 100.

Alternatively, instead of steps 6 to 8 described above, in step 6', the plate 100 is machined by machining the material using CAD / CAM dedicated software based on the generated three-dimensional image of the plate 100. May be manufactured.

A plurality of representative plates among the plurality of plates manufactured in this manner may be constructed as a set of plates. A typical set of plates comprises a curved surface that fits into a bone (eg, tibia) having a different characteristic shape. The number of plates included in a representative set of plurality of plates can be any integer of 2 or more, such as, but not limited to 9, 16, 25, and the like. For example, when preparing three different sizes and three different curvatures for each size, nine types of plate sets can be prepared.

Which plate of a representative set of plates is applied to a patient can be determined, for example, by contact rate analysis to determine the contact rate between the contact surface of the plate and the surface of the bone, and / or the plate. It may be determined by performing a stress analysis in advance to analyze the magnitude and position of the stress applied to the bone screw for fixing and the plate. For example, a scanning device capable of scanning a patient's bone (eg, tibia) scans the patient's bone (eg, tibial), acquires scanning data of the patient's bone (eg, tibial), and scans the device. The scanning data of the patient's bone is transmitted to the server device configured to be able to communicate with the server device, and the server device refers to the database section connected to the server device and is stored in the database section. Of the plates included in a representative set of plates, the patient's bones, based on information about each of the multiple plates (eg, the parameters described above for plate 100) and scan data of the patient's bones. By specifying the plate having the highest contact rate with the patient as the plate to be applied to the patient, the plate to be applied to the patient may be specified from a set of a plurality of representative plates. In the above-mentioned contact rate analysis, it is assumed that the plate and the bone are in "contact" when the distance between the contact surface of the plate and the surface of the bone is equal to or less than a predetermined distance. The predetermined distance is, for example, 0.7 mm, 0.5 mm, and 0.3 mm, but is not limited thereto.

Further, in order to promote bone fusion in the bone defect portion, a calcium phosphate-based ceramic block (for example, β-TCP) may be supplemented in the bone defect portion.

FIG. 2A shows an example of the state after high tibial osteotomy in which the plate 100 is fixed to the tibia. FIG. 2B is a cross-sectional view of the tibia including the medial tibial crest.

A bone defect is formed in the bone so that the alignment of the bone becomes normal, and the plate 100 has a bone defect proximal bone portion (proximal bone portion of the separated bone) and a bone defect portion of the bone. And the bone defect of the bone and the distal bone (distal bone of the separated bone) are fixed and configured to maintain the normal state of bone alignment.

The plate 100 is configured to have a shape along the surface (convex surface) of a bone (eg, tibia). For example, if the bone is tibia, the plate 100 has a shape along the surface of the tibial crest of the tibia. The "shape along the surface of the bone" excludes the surface of the bone excluding the defect and the portion corresponding to the defect on the curved surface 103 of the plate when the bone is applied to the intended fixation site of the bone. It means that the distance from the portion is 5 mm or less over 90% or more of the area of the curved surface 103 (excluding the portion corresponding to the defective portion). For example, a plate having "a shape along the surface including the medial tibial ridge of the tibia" has a distance between the inner surface (curved surface) of the plate and the surface of the bone when the plate is applied to the medial tibial ridge. , Excluding the part corresponding to the bone defect, it means that it is 5 mm or less over 90% or more of the inner surface.

In the example shown in FIG. 2A, the plate 100 follows the surface of the tibial crest on the medial side of the tibia, unlike conventional plates (T-shaped plates) that are placed on a substantially plane of the proximal anterior medial aspect of the tibia. It is configured so that it can be placed on the medial tibial crest (posterior medial tibia). More specifically, with reference to FIG. 2B, the plate 100 is a portion of the substantially flat proximal anterior medial aspect of the tibia, a portion of the substantially flat posterior surface of the tibia, and the convex medial tibia between them. It is configured so that it can be arranged to support the ridge. The plate 100 of the present invention differs from the conventional plate in this respect because the conventional typical plate is arranged so as to support only the proximal anterior medial aspect of the tibia. The fact that the plate 100 can be placed on the posterior medial side of the tibia makes it possible to three-dimensionally support the posterior medial tibia to which the greatest load is applied after osteotomy, as compared with the conventional flat plate type plate. Can also have advantages. Further, by supporting the posterior medial side of the tibia to which the maximum load is applied, stress is not generated in the bone defect portion (or the filler filled in the bone defect portion), and the stability of the plate 100 and the affected portion can be improved. It is possible. Further, in one embodiment, the plate 100 is more rigid than the conventional substantially flat plate (T-shaped plate) due to having a shape along the surface of the tibial crest on the medial side of the tibia. It has the strength to withstand bending and twisting. Further, since the dimensions of the plate 100 (for example, width, height, outer shape) can be determined according to the dimensions (for example, size, surface shape) of the affected part of the patient, the shape of the plate 100. High degree of freedom in design.

In some cases, the conventional plate placed on the anterior medial side of the tibia cannot support the load on the posterior tibia and the inclination on the posterior tibia becomes too large. On the other hand, in the plate 100 of the present invention, the plate Since 100 is placed along the surface of the tibial ridge posterior to the tibia, such cases can be reduced.

FIG. 3 shows a modified example of the shape of the plate.

FIG. 3A shows an example in which the size of the lower part of the plate is increased. In the example shown in FIG. 3 (a), the tibia has medial condyle of tibia (ie, proximal bone defect) 1, medial tibial ridge (ie, distal bone defect) 2, and bone defect. 3 and. In the example shown in FIG. 3 (a), the plate 100 has a concave surface inward along the tibial surface, has a width across the tibial ridge 4, and connects the upper 1 and the lower 2 so as to connect. Have been placed. The proximal portion of the plate (ie, the proximal portion 105) is provided with three holes 107, and the distal portion of the plate (ie, the distal portion 106) is bordered by the longitudinal axis of the plate. There are two holes 107 on each side. By fixing the plate to the tibia through a locking mechanism (not shown) through the hole 107, the plate is fixed to the tibia with a high fixation force. It is possible to increase the number of holes 107 by deforming the plate.

FIG. 3B shows an example in which the plate thickness is reduced and the protrusion 108 is provided only around the hole 107. By providing the protruding portion 108 only around the hole 107, a locking mechanism (not shown) can be provided in the hole 107. From the viewpoint of strength, the plate thickness is preferably 1 mm or more.

2. Surgery and treatment using a plate As a surgical procedure using the plate 100 of the present invention, "an incision is provided posteriorly (for example, near the medial tibial ridge) than the conventional (proximal anterior medial aspect of the tibia). Any osteotomy that meets at least the condition of "" can be adopted.

As an example of the surgical procedure using the plate 100 of the present invention, the open wedge HTO or osteosynthesis for fracture of the proximal tibial osteotomy is adopted. Regardless of the technique
A) The step of making an incision in the skin to expose the tibia,
B) Steps to perform osteotomy at the appropriate part of the tibia,
C) If necessary, after confirming that the angle is obtained based on the information obtained by X-ray or the like, an artificial bone is inserted (prosthesis), and then the bone separated by the plate and the bone screw of the present invention. Includes the step of fixing the D) and the step of merging the incised surface.

Here, in step C), where the conventional plate was applied and fixed to the proximal anterior medial aspect of the tibia, the plate of the present invention is applied and fixed to the medial tibial crest.

Alternatively, pre-analysis (eg, preoperatively) may be used to place on the patient's bone the plate that best fits the patient's bone, selected from a set of representative plates. .. More specifically, by scanning the patient's bone (eg, tibia) with a scanning device capable of scanning the patient's bone (eg, tibia), the patient's bone (eg, tibia) Contact rate analysis is taken to obtain a CT image and use the CT image of the patient's bone to calculate the contact rate between the surface of the patient's bone and the surface of the plates contained in a representative set of multiple plates. The plate with the highest contact rate with the surface of the patient's bone (that is, the plate with the highest contact with the surface of the patient's bone) is selected from among a plurality of typical plates, and is rearward than before. In any osteotomy in which an incision is provided, the skin or the like may be incised to expose the tibia, the necessary osteotomy of the tibia may be performed, and a selected plate may be placed in the bone of the patient. In the above-mentioned contact rate analysis, it is assumed that the plate and the bone are in "contact" when the distance between the contact surface of the plate and the surface of the bone is equal to or less than a predetermined distance. The predetermined distance is, for example, 0.7 mm, 0.5 mm, and 0.3 mm, but is not limited thereto.

An example of a typical set of plates described above is nine plates 100. Each of the nine plates 100 is determined by a combination of plate sizes (enlarged size, reference size, reduced size) and a combination of curvatures of the curved surfaces of the plates (curvature A, reference curvature, curvature B). It can be a thing. Here, the enlarged size refers to a size obtained by enlarging the standard size with a fixed aspect ratio (for example, 110% enlargement), and the reduced size refers to a size obtained by enlarging the standard size with a fixed aspect ratio (for example, 90% reduction). , Curvature A means a curvature smaller than the reference curvature, and curvature B means a curvature larger than the reference curvature. For example, a plate with curvature A can have a shape along the convex surface of the first bone (eg, the tibia of the first patient), and a plate with curvature can have a second bone (eg, first). It can have a shape along the convex surface of the tibia of 2 patients).

The parameters for determining each plate of the set of nine plates 100 are not limited to the size of the plate and the curvature of the curved surface of the plate. For example, in addition to the size of the plate and the curvature of the curved surface of the plate, or in place of the size of the plate and the curvature of the curved surface of the plate, the thickness of the plate, the weight of the plate, the position of the holes, the size of the holes, the holes. The number of plates and the like may be set as parameters for determining each plate of a set of nine plates 100.

3. 3. Kit The present invention also provides a kit for fixing bones that are at least partially separated. The kit of the present invention includes the plate 100 described above and at least one bone screw for fixing the plate 100 to the bone. The kit of the present invention may include a first plate and a second plate having a mirror image relationship with the first plate. The kit of the present invention may further include a locking mechanism for integrating at least one bone screw and the plate 100.

The present invention has been described above with reference to preferred embodiments for ease of understanding. Hereinafter, the present invention will be described based on examples, but the above description and the following examples are provided for purposes of illustration only and not for the purpose of limiting the present invention. Therefore, the scope of the present invention is not limited to the embodiments and examples specifically described in the present specification, but is limited only by the scope of claims.

FIG. 4 shows an example of the appearance of the plate 100.

The plate designer determines the shape of the wedge to be excised from the proximal tibia from the patient's lower limb radiograph so that the knee joint surface is close to normal, and then the tibia is based on the image of the proximal knee. The outer shape of the plate to be attached to the site including the medial tibial ridge was determined. In this example, the designer then hypothesized that the thickness of the plate was 3 mm, and determined on CAD a three-dimensional shape having a curved surface having the same shape as the tibial surface shape around the attachment site. In this embodiment, the plate was manufactured by laminated modeling based on this three-dimensional shape. The laminated molding device used was Eosint M270, and titanium powder having a particle size of 45 μm or less was used as a raw material for the plate. Further, the setting conditions of the laminated modeling apparatus were that the laser light output was 150 W, the laser light scanning speed was 200 mm / s, and the laser light scanning interval was 120 μm. After removing the titanium particles adhering to the formed plate surface, the surface of the plate 100 was polished using a barrel polishing device. Then, as shown in FIG. 4, the machine is machined so as to provide three holes 107 in the proximal portion of the plate and two holes 107 in the distal portion of the plate in the direction of insertion into the tibia. Was done.

In the example shown in FIG. 4, the plate 100 has a three-dimensional and axially short shape corresponding to the posterior medial bone shape with reference to the tibial 3DCT of a patient with knee osteoarthritis, and the tibial medial tibia. It has a curved surface along the tibial surface including the ridge, and has a shape with a larger curvature as it approaches the articular surface (that is, the proximal bone part of the bone defect), and both sides of the wedge-shaped bone defect part are used with multiple bone screws. It is characterized in that it can be fixed.

Holes for inserting bone screws were provided on both sides of the tibial crest. As a result, the fixing force of the plate can be dispersed, and the fixing force of the plate can be applied from both sides across the ridgeline of the tibial ridge. In addition, the insertion directions of the plurality of bone screws are provided so as not to exist in the same plane in order to increase the fixing force. Since the plate of this embodiment was provided with a locking mechanism (not shown) for fixing the bone screw to the plate, after the plate was fixed to the bone, the plurality of bone screws were integrated with the plate. Therefore, the insertion directions of the plurality of bone screws do not change.

Two FEM (finite element method) analysis experiments comparing the conventional T-shaped plate and the plate 100 of the present invention will be described below.
(1) Experiment to verify the deformation and stress generated in the plate when compressive force is applied to the knee joint with the plate attached to the wedge-shaped incision (bone defect) of the tibia (2) Tibial wedge-shaped An experiment to verify the deformation and stress generated in the plate when a turning force is applied to the knee joint with the plate attached to the notch.

FIG. 5 shows a comparison (surface only) of the stresses generated on the plate when a compressive force is applied to the knee joint with the plate attached to the wedge-shaped notch of the tibia. FIG. 6 shows a comparison (front and back) of stresses generated on a plate when a compressive force is applied to the knee joint with the plate attached to the wedge-shaped notch of the tibia. FIG. 7 shows a comparison of the stresses generated on the plate when a turning force is applied to the knee joint with the plate attached to the wedge-shaped notch of the tibia.

The analysis software "mechanical finder" was used for the FEM analysis. Moreover, the material of the assumed plate is pure titanium. In addition, various dimensions and analysis conditions of the conventional plate used in the experiment and the plate 100 of the present invention are as shown below.

As a result of the experiment, the following became clear.

(1) Compressive force application experiment-Stress generated in the plate: In the conventional plate, the stress generated in the plate due to the compressive force on the knee joint is concentrated in one place, while in the plate of the present invention, the compressive force on the knee joint is concentrated. Dissipated the stress generated in the plate and relaxed the stress concentration.
-Stress generated in the bone: With the conventional plate, the displacement amount of the bone in the fixed part can be small, but the displacement amount of the bone in the non-fixed part is large. As a result, in the conventional plate, there was a place where the stress on the bone due to the compressive force on the knee joint was concentrated. On the other hand, in the plate of the present invention, the total displacement of the bone is larger than that of the conventional plate (about 0.02 mm), but the displacement of the bone does not increase only in a certain place. As a result, in the plate of the present invention, stress concentration on the bone was relaxed.

(2) Swinging force application experiment-Stress generated in the plate: In the conventional plate, the stress is concentrated in the hole due to swirling, whereas in the plate of the present invention, the stress generated in the plate due to the swirling force to the knee joint is dispersed. Stress concentration was relaxed. The stress applied to the posterior bone screw was greater than the stress applied to the anterior bone screw.
-Stress generated in bone: In the conventional plate, there were places where the amount of bone displacement was large and places where the amount of bone displacement was small, and stress concentration was also observed in certain places. On the other hand, in the plate of the present invention, the overall displacement of the bone was more uniform than that of the conventional plate, and the concentration of stress generated in the bone was relaxed.

Consideration Since a conventional plate has a plate shape with a width of 16 mm and a thickness of 3 mm and a length of 100 mm, when a compressive force is generated on the plate, the plate is bent and the torsional force is increased. It twists without resisting. As a result, stress was concentrated in one place.

On the other hand, since the plate of the present invention is wide and curved along the surface of the tibia, the plate has high rigidity and is not easily deformed. Therefore, it is considered that the plate of the present invention has excellent strength in a state of being fixed to the bone even if the plate alone is used, and a fixing force higher than that of the conventional plate can be obtained with respect to the vertical compressive force and the turning force. In addition, it is possible to provide a highly durable and stable plate by making a part of the bone screw (that is, the bone screw to which a larger stress is applied) a bone screw having higher strength than the other bone screw. it can.

In addition, the plate of the present invention has a shorter plate length (that is, longitudinal length) as compared with a conventional plate that requires an opening of about 11 cm, so that the wound is smaller than the conventional plate. It is possible to operate at (for example, about 4 cm to about 5 cm). In fact, the plate of the present invention could be placed in the affected area through an opening about about half that of a conventional plate.

From the above, according to the plate 100 of the present invention, there are clinical advantages in the following points.
-By arranging the plate 100 on the posterior medial side where stress is most applied mechanically, it is possible to achieve stability of the bone defect portion, and therefore, it is possible to achieve early rehabilitation.
-Because the plate 100 has a shape along the posterior medial tibial ridge of the tibia, stress is not concentrated on the plate 100 and therefore the plate 100 is conventional with an axial length of one-third that of a conventional plate. Has a fixing force higher than that of the plate.
-Since the height of the plate 100 is small, it is possible to perform small skin incision and minimally invasive surgery, and as a result, it is possible to relieve the patient's pain and to achieve early getting out of bed and early rehabilitation by rehabilitation. ..
-Since the plate 100 is installed on the posterior medial tibial ridge over the bone defect, it is possible to prevent excessive posterior tilting of the tibial articular surface.
• Because the plate 100 is placed on the posterior medial tibial crest, the patient is less likely to touch the plate 100 subcutaneously and therefore less likely to feel pain.

(Application to other than high tibial osteotomy (HTO))
It will be described below that the plate 100 of the present invention can be more effectively applied to the treatment of fractures in the proximal part of the knee joint surface on the tibial side.

FIG. 8 shows an example in which the plate 100 is applied to the treatment of a fracture in the proximal part of the knee joint surface on the tibial side.

FIG. 8A shows a case in which the fracture line extends posteriorly and medially to the tibia. FIG. 8B shows an example in which the plate 100 is applied to the state shown in FIG. 8A.

In the case where the fracture line extends to the posterior medial side of the tibia as shown in FIG. 8A, a plate 100 that matches the outer shape of the proximal bone portion of the bone defect is manufactured by using the laminated molding method. As shown in FIG. 8B, the plate 100 can integrally grip the tibia and the fractured bone fragment, and the tibia and the fractured portion can be screwed together by using a bone screw. It can be integrated with a bone fragment. As a result, it is possible to reduce the labor during surgery, and it is possible to accurately restore the proximal tibia and secure the joint surface.

In the above-described embodiment, the application of the plate 100 of the present invention to human (patient) bone has been described, but the present invention is not limited thereto. The plate 100 of the present invention can be applied to the bones of any mammal.

(Set of plate 100)
As an example of the above-mentioned representative set of a plurality of plates, nine plates 100 of the present invention may be constructed as one set. The nine plates 100 may be determined, for example, by a combination of the size of the plate with respect to the reference plate shown in FIGS. 1A-1D and the curvature of the curved surface of the plate. That is, each of the nine plates 100 is determined by the combination of the plate size combination (enlarged size, reference size, reduced size) and the curvature of the curved surface of the plate (curvature A, reference curvature, curvature B). Can be. Here, the enlarged size refers to a size obtained by enlarging the standard size with a fixed aspect ratio (for example, 110% enlargement), and the reduced size refers to a size obtained by enlarging the standard size with a fixed aspect ratio (for example, 90% reduction). , Curvature A means a curvature smaller than the reference curvature, and curvature B means a curvature larger than the reference curvature. For example, a plate with curvature A can have a shape along the convex surface of the first bone (eg, the tibia of the first patient), and a plate with curvature can have a second bone (eg, first). It can have a shape along the convex surface of the tibia of 2 patients). By providing (eg, for sale) nine plates 100 composed of a combination of such plate size and curvature of the curved surface of the plate, bones having different convex shapes of different patients (eg, for sale). The plate that best fits the tibia) can be identified from the set of nine plates 100.

The parameters for determining each plate of the set of nine plates 100 are not limited to the size of the plate and the curvature of the curved surface of the plate. For example, in addition to the size of the plate and the curvature of the curved surface of the plate, or instead of the size of the plate and the curvature of the curved surface of the plate, the weight of the plate, the position of the holes, the size of the holes, the number of holes, etc. It may be set as a parameter for determining each plate of a set of nine plates 100.

(Selection of the optimum plate by analysis)
For example, pre-analysis (eg, preoperatively) may be used to select a plate that fits the patient's bone from a set of representative plates. More specifically, by scanning the patient's bone (eg, tibia) with a scanning device capable of scanning the patient's bone (eg, tibia), the patient's bone (eg, tibia) Contact rate analysis is taken to obtain a CT image and use the CT image of the patient's bone to calculate the contact rate between the surface of the patient's bone and the surface of the plates contained in a typical set of plates. The plate having the highest contact rate with the surface of the patient's bone (that is, the plate having the highest contact with the surface of the patient's bone) may be selected from a plurality of typical plates. The high contact rate between the surface of the bone and the surface of the plate is significant because the fixing force of the plate is increased. In the above-mentioned contact rate analysis, it is assumed that the plate and the bone are in "contact" when the distance between the contact surface of the plate and the surface of the bone is equal to or less than a predetermined distance. The predetermined distance is, for example, 0.7 mm, 0.5 mm, and 0.3 mm, but is not limited thereto.

The contact rate analysis described above can be performed, for example, in the following procedure:
A) The surface of the plate on the tibial side is the tibial surface, and the area of the tibial surface is calculated as the tibial surface area;
B) Calculate the area of the plate surface near the tibial surface as the contact area;
C) The contact rate is calculated as a 100% fraction with the contact area as the numerator and the tibia surface area as the denominator.

The present invention is useful as providing plates, kits and the like for fixing bones that are at least partially separated.

100 Plate 101 End 102 End 103 Curved surface 104 Curved surface 105 Proximal 106 Distal 107 Hole 108 Protruding

Claims (10)

A plate for fixing bones that are at least partially separated, said bone having a bone defect, a proximal bone and a distal bone, the plate.
The first end corresponding to the proximal bone and
The second end corresponding to the distal bone and
It is provided with a first curved surface along the substantially circumferential direction of the bone.
The plate is a plate having a shape along the surface of the convex surface of the bone. The plate of claim 1, wherein the convex surface of the bone is the medial tibial crest of the tibia. Claim 1 or claim 1, wherein the first curved surface has at least a first curvature at the first end and a second curvature at the second end that is greater than the first curvature. 2. The plate according to 2. The plate comprises at least one fixation portion for fixing the plate to the bone, and the at least one fixation portion includes a first fixation portion arranged in close proximity to the first end portion. The first fixing portion and / or the second fixing portion is arranged along the substantially circumferential direction, including a second fixing portion arranged in the vicinity of the second end portion. The plate according to any one of claims 1 to 3. The plate according to claim 4, wherein the at least one fixing portion includes a hole for inserting a bone screw. The plate according to any one of claims 1 to 5, wherein the plate has a shape extending in a substantially circumferential direction in a fan shape from the second end portion toward the first end portion. A kit for fixing bones that are at least partially separated, said kit.
The plate according to any one of claims 1 to 6,
With at least one bone screw for fixing the plate to the bone,
A kit comprising the plate and a second plate having a mirror image-like shape. The kit according to claim 7, for high tibial osteotomy. A set of plates according to any one of claims 1 to 6.
The set of plates comprises at least a first plate and a second plate.
The first plate has a shape along the convex surface of the first bone.
The second plate is a set of plates having a shape along the convex surface of the second bone, which is different from the first bone. The set of plates according to claim 9, wherein the set of plates comprises different plates in at least one parameter of size, curvature, thickness, and number of holes.