JP2016209339A - Bone bonding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bone bonding material which is less likely to move in the bone and prevents a divided surface of the bone from being easily displaced, even when being used for patients having a low density of trabecula in the medullary cavity due to the osteoporosis or the like.SOLUTION: A bone bonding material 10 can be inserted into the cancellous bone 110 of the divided sternum 100, and has a longitudinal component and a lateral component, where the longitudinal component is formed along the divided surface 101 of the sternum 100 and the lateral component is so formed as to cross the divided surface 101 of the sternum 100.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an osteosynthesis material that is inserted into cancellous bone to join divided bones.

  In the surgical field such as orthopedics, plastic surgery, thoracic surgery, and brain surgery, when a bone is divided by an incision or the like, a pin-shaped bone bonding material is inserted into the cancellous bone exposed on the bone splitting surface and divided. Bone is joined (for example, refer to Patent Document 1).

  As shown in FIG. 15A, when the sternum 100 is divided by a median sternum incision, a dividing surface 101 is formed along the longitudinal direction of the sternum 100. As shown in FIG. 15B, approximately half of each of the plurality of osteosynthesis materials 200 was inserted into one cancellous bone 110 of the divided sternal 100, and the remaining portion of each osteosynthesis material 200 was divided. By inserting into the other cancellous bone 110 of the sternum 100, the sternum 100 is joined by a plurality of osteosynthesis materials 200.

Japanese Patent No. 2969217

  However, even if a plurality of osteosynthesis materials 200 are inserted into the cancellous bone 110, the split surface 101 may be displaced during the period until the sternum 100 is restored. This is because when the trabecular density of the cancellous bone 110 is low due to osteoporosis or the like, when the force is applied to the sternum 100, the cancellous bone 110 cannot fully support the force applied to the bone bonding material 200. FIG. ), It is considered that the posture of the bone cement 200 with respect to the cancellous bone 110 changes as exemplified by a two-dot chain line. In addition, although the subject is mentioned here in the case where the sternum 100 is divided | segmented by incision as an example, when various bones other than the sternum 100 are divided | segmented by incision, and various reasons including the sternum 100 for reasons other than incision The same problem may occur when the bone of the bone is divided.

  An object of the present invention is to provide an osteosynthesis material that is difficult to move in the bone and is less likely to be displaced in the bone splitting surface even when used in a patient with low trabecular density in the medullary cavity for reasons such as osteoporosis. Is to provide.

  [1] One form of the osteosynthesis material according to the present invention is an osteosynthesis material that can be inserted into a cancellous bone of a divided bone, and the osteosynthesis material has a longitudinal component and a transverse component, The longitudinal direction component is formed so as to follow the bone splitting surface, and the short direction component is formed so as to intersect the bone splitting surface.

  Tests confirm that when split bones are joined with this bone joint material, bone split surfaces are less likely to be displaced than when split bones are joined with pin-shaped bone joint materials. It was done. This is because the main bone bonding material is inserted into the cancellous bone so that the longitudinal direction is along the bone dividing surface, so that the dividing surface is displaced as compared with the case where a pin-shaped bone bonding material is used. It is considered that the shearing force is strongly influenced by the present bone bonding material. In addition, since the osteosynthesis has a longitudinal component, the osteosynthesis is not easily displaced after the osteosynthesis is inserted into the cancellous bone.

[2] According to an example of the osteosynthesis material, the osteosynthesis material includes at least one projection protruding in a short direction of the osteosynthesis material.
According to this osteosynthesis, since a sharp part is formed by the protrusion, the insertion resistance when the osteosynthesis is inserted into the cancellous bone is reduced. For this reason, it is possible to smoothly insert the osteosynthesis into the cancellous bone without forming a pilot hole in the cancellous bone.

[3] According to an example of the osteosynthesis material, the plurality of protrusions are formed so as to project to one side and the other side in the short direction of the osteosynthesis material.
According to this bone bonding material, insertion resistance when inserted into cancellous bone is reduced. Further, since the cancellous bone enters between the plurality of protrusions in each of one and the other of the divided bones, the position of the bone bonding material with respect to the bone is more difficult to shift due to the anchor effect.

[4] According to an example of the osteosynthesis material, the plurality of protrusions are formed side by side in the longitudinal direction of the osteosynthesis material.
According to this bone bonding material, insertion resistance when inserted into cancellous bone is further reduced. Further, since the cancellous bone enters between the plurality of protrusions, the position of the bone bonding material with respect to the bone is difficult to shift due to the anchor effect.

[5] According to an example of the bone cement, the shape of the protrusion in a plan view is a surface shape.
According to this bone bonding material, since the shearing force that causes a shift in the split surface is strongly received by the protrusion, the split surface of the bone is not easily shifted.

[6] According to an example of the bone bonding material, the thickness of the protrusion becomes thinner toward the tip of the protrusion.
According to this osteosynthesis, since the tip of the protrusion is formed more sharply, the insertion resistance when the osteosynthesis is inserted into the cancellous bone is further reduced. For this reason, it is possible to more smoothly insert the osteosynthesis into the cancellous bone without forming a pilot hole in the cancellous bone.

[7] According to the example of the bone cement, the shape in the side view is a wave shape.
According to this osteosynthesis, since the cancellous bone enters the recess formed by the wave shape, the position of the osteosynthesis with respect to the bone is difficult to shift due to the anchor effect.

[8] According to an example of the osteosynthesis material, the thickness of the side portion in the transversal direction of the osteosynthesis material becomes thinner toward the edge in the transversal direction of the osteosynthesis material.
According to this osteosynthesis, since the shape in the lateral direction is a tapered shape, the insertion resistance when the osteosynthesis is inserted into the cancellous bone is reduced. For this reason, it is possible to smoothly insert the osteosynthesis into the cancellous bone without forming a pilot hole in the cancellous bone.

[9] According to an example of the bone bonding material, the bone bonding material has a shape that can be inserted into the cancellous bone of the sternum.
The sternum is frequently acted on by breathing and daily activities. For such a part, when an osteosynthesis having a longitudinal component along the split surface of the sternum is used, a shearing force that causes a shift in the split surface is strongly received by the osteosynthesis, so The split surface of the sternum is likely to be kept stable until the sternum is restored.

[10] According to an example of the osteosynthesis, the longitudinal dimension of the osteosynthesis is equal to or greater than the intercostal distance.
According to this bone bonding material, it was confirmed by a test that the dividing surface of the sternum is less likely to be displaced than when the longitudinal dimension is less than the intercostal distance. This is considered to be mainly due to the fact that when force is applied to the osteosynthesis, the force is received by the ribs adjacent in the vertical direction.

[11] According to an example of the osteosynthesis, the longitudinal dimension of the osteosynthesis is included in a range of 20 mm to 90 mm.
When the longitudinal dimension is 20 mm or more, the dividing surface of the sternum is more difficult to shift. When the dimension in the longitudinal direction is 90 mm or less, when the osteosynthesis is inserted into the cancellous bone of the divided sternum, the osteosynthesis is unlikely to hit the cortical bone, and the insertability of the osteosynthesis is further enhanced.

[12] According to an example of the osteosynthesis, the dimension in the short direction of the osteosynthesis is included in a range of 15 mm to 40 mm.
When the dimension in the short direction is 15 mm or more, the insertion resistance when the bone cement is inserted into the cancellous bone is further reduced. When the dimension in the short direction is 40 mm or less, the possibility that the protrusion is strongly pressed against the cortical bone when the osteosynthesis material is inserted into the cancellous bone of the divided sternum is reduced.

[13] According to an example of the osteosynthesis, the dimension in the thickness direction, which is a direction orthogonal to the longitudinal direction of the osteosynthesis, in a side view is included in the range of 0.5 mm to 6.0 mm.
When the dimension in the thickness direction is 0.5 mm or more, the dividing surface of the sternum is more difficult to shift. When the dimension in the thickness direction is 6.0 mm or less, when the osteosynthesis material is inserted into the cancellous bone of the divided sternum, the osteosynthesis material hardly hits the cortical bone, and the insertability of the osteosynthesis material is further improved.

[14] According to an example of the osteosynthesis material, the thickness of the osteosynthesis material is included in a range of 0.3 mm to 3.0 mm.
When the plate thickness is 0.3 mm or more, since the osteosynthesis is not easily deformed when the osteosynthesis is inserted into the cancellous bone, the insertability of the osteosynthesis is further enhanced. When the plate thickness is 3.0 mm or less, the amount of bone bonding material, which is a foreign substance to the human body, is suppressed from being inserted into the bone, so that the bone into which the bone bonding material has been inserted is easily kept in a good state.

  According to the above-mentioned osteosynthesis, even if it is used for a patient with low trabecular density in the medullary cavity for reasons such as osteoporosis, it is difficult to move in the bone and displacement of the bone splitting surface is difficult to occur.

FIG. 3 is a plan view of the bone cement of the embodiment. FIG. 3 is a plan view of a belt-like body. FIG. 2 is a side view of the bone cement of FIG. 1. FIG. 5 is a plan view of a part of the osteosynthesis material according to a modification. FIG. 2 is a diagram relating to a sternum in which the bone cement of FIG. 1 has been inserted. Is a table showing characteristic specifications of Samples 1-5. These are graphs showing the results of insertion tests using samples 1 and 2. These are graphs showing the results of a shear test using Samples 1 and 2. These are graphs showing the results of insertion tests using samples 1 and 3. These are graphs showing the results of a shear test using Samples 1 and 3. These are graphs showing the results of insertion tests using Samples 3 and 4. These are graphs showing the results of a shear test using Samples 3 and 4. These are graphs showing the results of insertion tests using Samples 3 and 5. These are graphs showing the results of a shear test using Samples 3 and 5. These are graphs showing the results of shear tests using samples 1-6. FIG. 5 is a perspective view of an osteosynthesis material according to a first modification. These are perspective views of the osteosynthesis material of the 2nd modification. These are the perspective views of the osteosynthesis of a 3rd modification. These are the figures regarding the sternum in which the conventional osteosynthesis was inserted.

(Embodiment)
FIG. 1 is an example of an osteosynthesis material 10 used to join a sternum that has been cut through a median sternum. Fig.5 (a) is a front view of the sternum 100 in which the bone joining material 10 was inserted, FIG.5 (b) is sectional drawing of the 5b-5b line | wire of Fig.5 (a).

  When the sternum handle 100X and the sternum body 100Y constituting the sternum 100 are incised through the median sternum, as shown in FIG. 5A, the sternal pattern 100X and the second sternum 100B are divided. As shown in FIG. 5 (b), the cancellous bone 110 is exposed on the dividing surfaces 101 of the first half sternum 100A of the sternum 100X and the first half sternum 100A of the sternum body 100Y. The second half sternum 100B of the sternum 100X and the second half sternum 100B of the sternum body 100Y have the same state. The bone cement 10 is cut out from the band 1 shown in FIG. 2 according to the length of the dividing surface 101 in the dividing direction SC of the sternum 100.

  An example of the material constituting the bone cement 10 is a high-strength implant material including a particle-reinforced composite material in which a bioresorbable bioceramic having surface bioactivity is mixed with a thermoplastic polymer having biodegradability. is there. An example of a high-strength implant material is disclosed in, for example, Japanese Patent No. 3239127.

  An example of bioceramics having surface bioactivity is any one of sintered or unfired hydroxyapatite, β-TCP, bioglass-based or crystallized glass-based biological glass, and diopside, or those It is a mixture of two or more of the above.

  Among them, calcined or unfired hydroxyapatite, bioglass bioglass, cerabital, crystallized glass AW glass ceramics, crystallized glass bioberit-1, β-crystallized glass, and diop It is considered that the side is more suitable for the bone cement 10.

  Moreover, as long as it is a bioabsorbable bioceramic, not only a bioceramic having surface bioactivity but also a bioceramic having no surface bioactivity can be used. As the polymer, a crystalline polymer or an amorphous polymer having biocompatibility can be used. Furthermore, since the polymer having biodegradability is absorbed by the living body, an operation for removing the bone bonding material 10 after bone fusion is unnecessary, and it is more preferable as a material for the bone bonding material 10. In general, a crystalline polymer has higher mechanical strength than an amorphous polymer. For this reason, the material of the bone bonding material 10 can be appropriately selected in consideration of the strength required for each target site into which the bone bonding material 10 is inserted. Examples of the thermoplastic polymer having biodegradability and absorbability include polylactic acid or various polylactic acid copolymers. An example of a polylactic acid copolymer is a lactic acid-glycolic acid copolymer.

  As shown in FIG. 1, the shape of the bone cement 10 in a plan view is a band shape having a longitudinal component that is a component in the longitudinal direction X and a transverse component that is a component in the lateral direction Y, and the longitudinal direction X Is formed along the dividing surface 101 of the sternum 100 shown in FIG. The first longitudinal end portion 11 that is one end portion in the longitudinal direction X of the bone cement 10 and the second longitudinal end portion 12 that is the other end portion have flat end surfaces. The first side portion 13 that is one side portion in the short direction Y of the bone cement 10 and the second side portion 14 that is the other side portion each have a plurality of protrusions 15.

  The plurality of protrusions 15 project in the lateral direction Y with respect to the center line of the bone cement 10 along the longitudinal direction X, and are formed side by side in the longitudinal direction X at each of the side portions 13 and 14. The shape of the protrusion 15 in plan view is a surface shape. The protrusion 15 of the first side 13 and the protrusion 15 of the second side 14 corresponding to each other in the longitudinal direction X form a set of protrusions 15 that protrude in opposite directions in the lateral direction Y. doing.

  The dimension from the root to the tip of the protrusion 15 (hereinafter referred to as “protrusion height PL”) is determined based on the root of one protrusion 15 and the other protrusion 15 constituting the set of protrusions 15 in the bone joining material 10. It is shorter than the dimension of the part between the roots. The pitch of the protrusions 15 adjacent in the longitudinal direction X (hereinafter referred to as “protrusion distance PP”) is approximately equal to the protrusion height PL.

  Waveforms are formed on the side portions 13 and 14 by a plurality of protrusions 15 arranged in the longitudinal direction X in plan view. According to the illustrated example, the shape of the protrusions 15 in a plan view is a triangular shape, and the number of protrusions 15 formed on each of the side parts 13 and 14 is six. The shape of the protrusion 15 can be changed to a protrusion shape as shown in FIG. 4, for example.

  The shape of the bone cement 10 in a side view is a wave shape, and an example thereof is a sine wave shape as shown in FIG. That is, the bone cement 10 includes a plurality of peaks 10A arranged in the longitudinal direction X in a side view and a plurality of valleys 10B formed between the peaks 10A adjacent in the longitudinal direction X.

  It is preferable that the dimension of each site | part of the osteosynthesis 10 shown by FIG. 1 and FIG. 3 is contained in the following range. A preferable range of the dimension in the longitudinal direction X (hereinafter referred to as “longitudinal dimension L”) is 20 mm to 90 mm. A preferable range of the dimension in the short direction Y (hereinafter, “short dimension W”) is 15 mm to 40 mm. A preferable range of the dimension in the thickness direction Z (hereinafter referred to as “thickness dimension H”) that is a direction orthogonal to the longitudinal direction X in a side view is 0.5 mm to 6.0 mm. The longitudinal dimension L is further preferably longer than the center-to-center distance (hereinafter referred to as “inter-radial distance RD”) of the radial notch 130 adjacent in the dividing direction SC of the sternum 100 in FIG. A preferable range of the plate thickness T of the bone cement 10 is 0.3 mm to 3.0 mm. In one example, the long dimension L is 45.5 mm, the short dimension W is 22.5 mm, the thickness dimension H is 3.0 mm, and the plate thickness is 0.7 mm. In addition, the distance RD between ribs is substantially equal to the distance between the centers of the ribs adjacent to each other in the dividing direction SC.

A procedure for joining the sternum 100 will be described with reference to FIG.
The divided sternum 100 is joined by the following procedure, for example. First, the first osteosynthesis material 10 is inserted into the cancellous bone 110 of the first semi-sternum 100A of the sternum body 100Y. At this time, the right side portion of the protrusion 15 formed on one of the first side portion 13 and the second side portion 14 of the first osteosynthesis material 10 is inserted into the cancellous bone 110 in which no pilot hole is formed. The right portion of the first bone bonding material 10 is pushed into the cancellous bone 110 until the length in the short direction Y of the right portion of the first bone bonding material 10 in the cancellous bone 110 reaches a predetermined length. It is.

  Next, the right portion of the second osteosynthesis material 10 is inserted into the cancellous bone 110 of the first semi-sternal 100A of the sternum 100X by the same procedure as described above. When the first osteosynthesis material 10 and the second osteosynthesis material 10 are respectively inserted into the cancellous bone 110, the first osteosynthesis material 10 and the second bone in the longitudinal direction of the first hemisternum 100A. A predetermined space is formed between the bonding material 10. Since the length of the sternum handle 100X in the dividing direction SC is shorter than the length of the sternum body 100Y, the longitudinal dimension L of the second osteosynthesis material 10 is shorter than the longitudinal dimension L of the first osteosynthesis material 10. Is preferred.

  Next, the dividing surface 101 of the second semi-sternal 100B is aligned with the dividing surface 101 of the first semi-sternal 100A. At this time, the left side portion of the first osteosynthesis material 10 and the left side portion of the second osteosynthesis material 10 are inserted into the cancellous bone 110 of the second hemisternum 100B. By passing through these procedures, the sternum 100 is joined by the two bone joining materials 10 as shown in FIG.

Actions and effects obtained by the bone cement 10 will be described.
The osteosynthesis material 10 is inserted into the cancellous bone 110 such that the longitudinal direction X is along the dividing surface 101 of the sternum 100. Therefore, when a vertical or anteroposterior shear force is applied to the sternum 100 to cause a shift in the dividing surface 101, compared to the case where the sternum 100 is joined by a pin-shaped bone joint material, The shearing force is strongly received by the bone cement 10. For this reason, even when the density of the trabecular bone of the cancellous bone 110 is low, the split surface 101 is not easily displaced.

  Moreover, the following effects are acquired when compared with the pin-shaped osteosynthesis 200 shown in FIG. When a shearing force is applied to the dividing surface 101 of the sternum 100 in which the pin-shaped osteosynthesis 200 has been inserted, the osteosynthesis is shown in the plan view of the sternum 100 shown in FIG. The material 200 may rotate with respect to the sternum 100. On the other hand, the osteosynthesis material 10 of the embodiment has a longer longitudinal component of the osteosynthesis material 10 along the dividing surface 101 than the transversal component of the osteosynthesis material 10 that intersects the dividing surface 101 of the sternum 100, and thus the sternum 100 When a shearing force is applied to the split surface 101, it is difficult to rotate with respect to the sternum 100.

According to the bone bonding material 10, the following effects are further obtained.
(1) A plurality of protrusions 15 are formed on the side portions 13 and 14. According to this configuration, when the bone cement 10 is inserted into the cancellous bone 110 of the first hemisternum 100A or the second hemisternum 100B, the sharp portion of the protrusion 15 first contacts the cancellous bone 110. The insertion amount of the protrusion 15 into the cancellous bone 110 gradually increases. For this reason, since the insertion resistance when the bone joining material 10 is inserted into the cancellous bone 110 is not temporarily applied but is dispersed at the time of insertion, the insertion is facilitated. In addition, since the cancellous bone 110 enters between the plurality of protrusions 15 in a state where the osteosynthesis material 10 is sufficiently inserted into the cancellous bone 110, the position of the osteosynthesis material 10 with respect to the sternum 100 is unlikely to shift due to the anchor effect.

  (2) The shape of the bone bonding material 10 in a side view is a wave shape. According to this configuration, the cancellous bone 110 enters the valley 10B, which is a recess formed between the adjacent peaks 10A in the longitudinal direction X. Therefore, the position of the bone bonding material 10 with respect to the sternum 100 is difficult to shift due to the anchor effect.

  (3) When the density of the trabecular bone in the medullary cavity of the sternum 100 is low due to reasons such as osteoporosis, the trabecular bone has a non-uniform distribution in a cross section perpendicular to the longitudinal direction of the sternum 100. The density of the trabecular bone decreases as it approaches the central portion of the cancellous bone 110, which is the central portion of the cross section, and the density of the trabecular bone increases as it approaches the cortical bone 120. When the osteosynthesis material 10 having a wave shape in the side view is used for joining the sternum 100, not only the central portion of the cancellous bone 110 having a low trabecular density but also a portion having a high trabecular density. Since the bone joining material 10 is also inserted into the portion near the cortical bone 120, the sternum 100 is firmly fixed by the bone joining material 10, and the stability of the sternum 100 is enhanced.

  (4) The sternum 100 is frequently subjected to force due to breathing and daily activities. When the bone bonding material 10 having the longitudinal direction X along the dividing surface 101 of the sternum 100 is used for such a portion, the bone bonding material 10 has a stronger shearing force to cause the dividing surface 101 to shift. Therefore, it is easy to keep the dividing surface 101 of the sternum 100 in a stable state until the divided sternum 100 is restored.

  (5) The longitudinal dimension L of the bone cement 10 is greater than or equal to the intercostal distance RD. According to this configuration, the dividing surface 101 of the sternum 100 is less likely to be displaced than when the longitudinal dimension L is less than the intercostal distance RD. The reason is considered as follows. As shown in FIG. 5A, since the width of the sternum 100 is narrow in the valley portion between the rib notches 130, the protrusion 15 of the osteosynthesis material 10 inserted into the sternum 100 is located in a portion near the cortical bone 120. To reach. Since the density of the trabecular bone is high as described above, the portion near the cortical bone 120 has high strength. For this reason, the protrusion 15 that has reached the portion near the cortical bone 120 is firmly supported, and the bone cement 10 is difficult to move relative to the sternum 100. For this reason, it is difficult for the bone cement 10 to rotate around an axis along the longitudinal direction of the body.

  (6) The longitudinal dimension L of the bone cement 10 is included in the range of 20 mm to 90 mm. When the longitudinal dimension L is 20 mm or more, the dividing surface 101 of the sternum 100 is more difficult to shift. When the longitudinal dimension L is 90 mm or less, when the osteosynthesis material 10 is inserted into the cancellous bone 110 of the first hemisternum 100A or the second hemisternum 100B, the osteosynthesis material 10 hardly hits the cortical bone 120, and the osteosynthesis The insertability of the material 10 is further improved.

  (7) The short dimension W of the bone cement 10 is included in the range of 15 mm to 40 mm. When the short dimension W is 15 mm or more, since the area of the bone bonding material 10 that receives the shearing force acting on the sternum 100 is large, the dividing surface 101 of the sternum 100 is more difficult to shift. When the short dimension W is 40 mm or less, the protrusion 15 may be strongly pressed against the cortical bone 120 when the osteosynthesis material 10 is inserted into the cancellous bone 110 of the first half sternum 100A or the second half sternum 100B. Is reduced.

  (8) The thickness dimension H of the bone cement 10 is included in the range of 0.5 mm to 6.0 mm. When the thickness dimension H is 0.5 mm or more, the split surface 101 of the sternum 100 joined by the bone cement 10 is more difficult to shift. When the thickness dimension H is 6.0 mm or less, the osteosynthesis material 10 is unlikely to hit the cortical bone 120 when the osteosynthesis material 10 is inserted into the cancellous bone 110 of the first half sternum 100A or the second half sternum 100B. In addition, the insertability of the bone cement 10 is further enhanced.

  (9) The plate thickness T of the bone cement 10 is included in the range of 0.3 mm to 3.0 mm. When the plate thickness T is 0.3 mm or more, since the osteosynthesis material 10 is not easily deformed when the osteosynthesis material 10 is inserted into the cancellous bone 110, the insertability of the osteosynthesis material 10 is further enhanced. When the plate thickness T is 3.0 mm or less, since the amount of the bone bonding material 10 that is a foreign substance to the human body is inserted into the sternum 100 is suppressed, the sternum 100 into which the bone bonding material 10 has been inserted is kept in a good state. Cheap.

(Example)
The inventor of the present application has an insertion test for confirming the relationship between the characteristic specifications of the osteosynthesis material 10 and the insertability of the osteosynthesis material 10 into cancellous bone, and the characteristics of the osteosynthesis material 10. And a shear test for confirming the relationship between the shear strength of the bone cement 10. Characteristic specifications of the bone cement 10 are a thickness dimension H, the number of protrusions 15, a protrusion height PL, a shape of the protrusions 15, a distance PP between protrusions, and a longitudinal dimension L. In this test, samples 1 to 5 shown in FIG. 6 were used. The sample 1 is the bone cement 10 exemplified in the above embodiment. “Triangle” described in the column of “projection shape” in FIG. 6 means the triangular shape of the protrusion 15 shown in FIG. 1 and the like, and “projection” means the projection shape shown in FIG.

  The conditions for the insertion test will be described. In the insertion test, a sternum model formed by a cancellous bone cell type block and an epoxy sheet was used. Epoxy sheets are an alternative material for cortical bone. Two epoxy sheets are overlapped and bonded, one of them is bonded to the surface of the cancellous bone cell block, another two epoxy sheets are overlapped and bonded, and one of them is the back of the cancellous bone cell block A sternum model was formed by bonding to the bone. The surface where the cancellous bone cell type block is exposed in the sternum model corresponds to the dividing surface 101 of the sternum 100. The cancellous bone cell block has a width dimension of 40 mm, a depth dimension of 60 mm, and a height dimension of 20 mm. The mass of the cancellous bone cell type block is 0.12 g / cc.

  The tester used was Autograph AG-20kNXD (manufactured by Shimadzu Corporation). The insertion test was performed according to the following procedure. First, the sternum model was set on the fixed jig of the testing machine, and the sample was set on the movable jig of the testing machine. Next, the movable jig was moved at a constant speed with respect to the fixed jig so that the protrusion 15 of the sample was inserted into the cancellous bone cell type block. Next, the movable jig was stopped when the length (hereinafter referred to as “insertion displacement”) of the bone cement 10 inserted into the cancellous bone cell type block reached a predetermined insertion displacement. The moving speed of the movable jig is 10 mm / min. There are four predetermined insertion displacements: 3 mm, 5.25 mm, 9.0 mm, and 11 mm. The testing machine detected a load (hereinafter referred to as “insertion load”) applied to the movable jig when the insertion displacement was a predetermined insertion displacement.

  The conditions of the shear test will be described. In the shear test, Sample 6 was used in addition to Samples 1-5. Sample 6 is a pin-type osteosynthesis 200 shown in FIG. The thickness of the bone cement 200 is 3.0 mm, and the longitudinal dimension is 45.5 mm. The sternum model and testing machine used are the same as in the insertion test. However, two sternum models were used in the shear test. The shear test was performed by the following procedure. First, the sample was inserted into the cancellous bone cell type block of one sternum model. Next, the cancellous bone cell type block of the other sternum model was inserted into the sample. The sample insertion displacement for each sternum model is substantially the same. By these operations, a sternum model in which the divided surfaces are joined by the sample is configured. Next, one sternum model was set on the fixed jig of the testing machine, and the other sternum model was set on the movable jig of the testing machine. Next, the movable jig was moved at a constant speed with respect to the fixed jig so that a shearing force was applied to the sample. Next, the movable jig was stopped when the amount of movement of the movable jig relative to the fixed jig (hereinafter referred to as “shear displacement”) reached a predetermined shear displacement. The moving speed of the movable jig is 10 mm / min. There are four types of predetermined shear displacements: 0.5 mm, 1.0 mm, 1.5 mm, and 3.0 mm. The test machine detected a load (hereinafter referred to as “shear load”) applied to the movable jig at the time when the insertion displacement was a predetermined shear displacement.

  FIG. 7A is a graph comparing the results of insertion tests on samples 1 and 2. FIG. 7B is a graph comparing the results of shear tests on samples 1 and 2. From these test results, it can be confirmed that as the thickness dimension H becomes longer, the insertability of the bone cement 10 becomes higher and the shear strength decreases. It is considered that the insertability of the bone bonding material 10 is related to the sharpness of the distal end portion of the protrusion 15 increasing as the thickness dimension H increases. Regarding the shear strength, it is considered that the area subjected to the shear load becomes narrower as the thickness dimension H becomes longer.

  FIG. 8A is a graph comparing the results of the insertion test on samples 1 and 3. FIG. 8B is a graph comparing the results of shear tests on samples 1 and 3. From these test results, it can be confirmed that as the number of the protrusions 15 decreases, the insertability of the bone bonding material 10 increases, and the shear strength does not show a significant change with respect to the change in the number of protrusions 15.

  FIG. 9A is a graph comparing the results of insertion tests on samples 3 and 4. FIG. 9B is a graph comparing the shear test results for Samples 3 and 4. From these test results, it can be confirmed that as the projection height PL becomes longer, the insertability of the bone bonding material 10 becomes higher, and the shear strength does not show a significant change with respect to the change in the projection height PL. It is considered that the insertability of the bone bonding material 10 is related to the sharpness of the tip of the protrusion 15 increasing as the protrusion height PL increases.

  FIG. 10A is a graph comparing the results of insertion tests on samples 3 and 5. FIG. 10B is a graph comparing the results of the shear test for Samples 3 and 5. From these test results, it can be confirmed that when the shape of the protrusion 15 is a protrusion shape, the insertability of the osteosynthesis material 10 is improved and the shear strength is reduced as compared with a triangular shape. It is considered that the insertability of the bone bonding material 10 is related to the fact that the tip of the protrusion 15 having a protrusion shape is sharper than the tip of the protrusion 15 having a triangular shape. Regarding the shear strength, it is considered that when the tip of the protrusion 15 has a protruding shape, the area under which the shear load is received becomes narrower than when the tip of the protrusion 15 has a triangular shape. .

  As shown from the results of the insertion test and the shear test, the insertability improves as the sharpness of the tip of the protrusion 15 increases, and the shear strength improves as the surface area of the bone cement 10 increases. Based on this relationship, it is obtained by the osteosynthesis material 10 by selecting the specific contents of the characteristic features of the osteosynthesis material 10 according to the bone state such as the type of bone to be joined and the bone density. It is thought that the effect obtained is further enhanced.

  FIG. 11 is a graph comparing the results of the shear test on Samples 1-6. From this test result, it can be confirmed that when the shear displacement is 1.5 mm and 3.0 mm, the shear strength of the osteosynthesis 10 is higher than the shear strength of the pin-type osteosynthesis 200. When the shear displacement is 3.0 mm, this tendency appears more remarkably. These test results are considered to be related to the fact that the bone bonding material 10 has a larger area to receive a shear load than the pin-type bone bonding material 200.

(Modification)
The description regarding the said embodiment is an illustration of the form which the osteosynthesis according to this invention can take, and it does not intend restrict | limiting the form. In addition to the above-described embodiment, the bone joining material according to the present invention can take a form in which, for example, the following modification example shown below and at least two modification examples that do not contradict each other are combined.

-The shape of the side part of the osteosynthesis 10 can be changed arbitrarily.
FIG. 12 shows a first modification in which the shape of the side portion of the bone cement 10 is changed. The osteosynthesis 10 according to this modification includes a pin 16 formed on the first longitudinal end portion 11 and a pin 16 formed on the second longitudinal end portion 12. Each pin 16 protrudes in one and the other in the lateral direction Y with respect to the center line of the bone cement 10 along the longitudinal direction X.

  FIG. 13 shows a second modification in which the shape of the side portion of the bone cement 10 is changed. The osteosynthesis material 10 of this modification is provided with pins 16 having substantially the same shape as these pins 16 in the intermediate portion in the longitudinal direction X in addition to the two pins 16 shown in the first modification.

  FIG. 14 shows a third modification in which the shape of the side portion of the bone cement 10 is changed. The osteosynthesis material 10 of this modification has a configuration in which all the protrusions 15 are omitted from the osteosynthesis material 10 of the embodiment shown in FIG. In the fourth modified example, the shape of the side view of the osteosynthesis material 10 of the third modified example is changed from a wave shape to a flat plate shape. In the fifth modification, in the third modification or the fourth modification, the plate thicknesses of the first side portion 13 and the second side portion 14 of the osteosynthesis material 10 toward the edge in the lateral direction Y. T becomes thin. That is, by changing the third modification or the fourth modification so that the first side 13 and the second side 14 have a tapered shape in the cross section along the lateral direction Y, Thus, the osteosynthesis 10 according to the fifth modification is obtained. According to this configuration, insertion resistance when the bone bonding material 10 is inserted into the cancellous bone 110 is reduced. In addition, when the osteosynthesis 10 is provided with the pin 16 like the 1st modification and the 2nd modification, the number can be changed to either 1 or 4 or more.

-The shape of the projection 15 in plan view can be arbitrarily changed. An example of the shape of the protrusion 15 is a rectangle, a semicircle, and a trapezoid.
-The shape of the bone joining material 10 in planar view can be changed arbitrarily. Examples of the shape in plan view are a triangular shape, a trapezoidal shape, a rhombus shape, an elliptical shape, and an oval shape. When the bone bonding material 10 does not include the protrusions 15, the shapes are formed by the edges of the bone bonding material 10, and when the bone bonding material 10 includes the plurality of protrusions 15, the distal ends of the protrusions 15 Each shape is formed.

  In another example relating to the shape of the protrusion 15 in plan view, the shape of the bone cement 10 in plan view is asymmetric with respect to the center line in the longitudinal direction X. In yet another example, the shape of the bone cement 10 in plan view is asymmetric with respect to the center line in the lateral direction Y.

  -The shape of the bone joining material 10 in side view can be changed arbitrarily. An example of the shape of the side view is a triangular wave, a sawtooth wave, a rectangular wave, a wave shape similar to these, and a wave shape having irregular changes. In another example, the shape of the side view is not a wave shape but a flat plate shape. In yet another example, the shape of the bone cement 10 in a side view is asymmetric with respect to the center line in the lateral direction Y.

  -In the bone joining material 10 of embodiment, although the thickness dimension H in each peak 10A is set constant, the thickness dimension H can be set for every peak 10A. In one example, two types of peaks 10 </ b> A having different thickness dimensions H are alternately formed in the longitudinal direction X of the osteosynthesis material 10. In another example, the plurality of peaks 10 </ b> A are formed such that the thickness dimension H gradually increases from one of the first longitudinal end 11 and the second longitudinal end 12 toward the other. In yet another example, a plurality of thickness dimensions H are gradually increased or decreased from the first longitudinal end portion 11 and the second longitudinal end portion 12 toward the central portion in the longitudinal direction X of the bone cement 10. A mountain 10A is formed.

  -The shape of the strip 1 in a side view can be arbitrarily changed. In one example, a first peak 10A and a second peak 10A having different thickness dimensions H are formed on one strip 1 (see FIG. 2). An example of the height of the first peak 10A is 3 mm, and an example of the height of the second peak 10A is 5 mm. The strip 1 includes a first portion in which a plurality of first peaks 10A are continuously formed, and a second portion in which a plurality of second peaks 10A are continuously formed. The first portion and the second portion are alternately formed in the longitudinal direction of the strip 1.

  According to this configuration, two types of osteosynthesis materials 10 having different thickness dimensions H from one band 1, that is, an osteosynthesis material 10 including one or more first peaks 10 </ b> A, and one or more The bone cement 10 including the second mountain 10A can be cut out. In addition, by cutting the strip 1 so as to include the boundary between the first portion and the second portion of the strip 1, one or more first peaks 10A and one or more second peaks 10A. Can be cut out. For this reason, the thickness dimension H of the bone cement 10 can be selected according to the shape of the sternum 100 for each patient. An example of a usage pattern for selecting the thickness dimension H is shown below.

  The thickness of the cancellous bone 110, which is the thickness of the medullary cavity, is different from each other in the upper part and the lower part of the sternum 100, and the thickness of the lower cancellous bone 110 may be thinner than the thickness of the upper cancellous bone 110. . One osteosynthesis material 10 including the first peak 10A and the second peak 10A can be inserted across the upper and lower parts of the sternum 100. In that case, the first mountain 10A is inserted into the lower part of the sternum 100, which is the thin part of the cancellous bone 110, and the second mountain 10A is inserted into the upper part of the sternum 100, which is the thick part of the cancellous bone 110. Therefore, it is easy to insert the bone cement 10 into the sternum 100. When the bone cement 10 is inserted into the sternum 100, the bone cement 10 reaches a portion close to the cortical bone 120, and the bone cement 10 Such force is strongly received by the cortical bone 120.

-The plate | board thickness T of the protrusion 15 can be changed arbitrarily. In one example, the plate thickness T of the protrusion 15 decreases from the root of the protrusion 15 toward the tip.
-The longitudinal dimension L of the bone cement 10 can be arbitrarily changed. In one example, the longitudinal dimension L is shorter than the intercostal distance RD. In another example, the longitudinal dimension L is longer than the intercostal distance RD.

-In the said embodiment, although the osteosynthesis 10 is cut out from the strip | belt shaped object 1, the osteosynthesis 10 can take the form formed separately.
The method for inserting the bone cement 10 into the cancellous bone 110 can be arbitrarily changed. In one example, a pilot hole is formed in the cancellous bone 110, and the bone cement 10 is inserted into the pilot hole.

  -The number of the osteosynthesis 10 inserted in the cancellous bone 110 of the sternum body 100Y can be changed arbitrarily. In one example, two or three osteosynthesis materials 10 are inserted into the cancellous bone 110 of the sternum body 100Y. The number of osteosynthesis materials 10 inserted into the cancellous bone 110 of the sternum pattern 100X can be similarly changed.

  In the above embodiment, an example is shown in which the bone cement 10 is inserted into each of the cancellous bone 110 of the sternum pattern 100X and the cancellous bone 110 of the sternum body 100Y, but the insertion of the bone cement 10 into each cancellous bone 110 is shown. The form can be arbitrarily changed. In one example, the bone cement 10 is inserted into only one of the cancellous bone 110 of the sternum pattern 100X and the cancellous bone 110 of the sternum body 100Y. For example, when the bone joining material 10 is inserted into the cancellous bone 110 of the sternum body 100Y and the bone joining material 10 is not inserted into the cancellous bone 110 of the sternum pattern 100X, the bone joining material 10 to be inserted into the cancellous bone 110 of the sternum body 100Y. The number can be arbitrarily selected. In a preferred example, the number is one or two. When two bone joining materials 10 are inserted into the cancellous bone 110 of the sternum body 100Y, the bone joining material 10 is compared with a case where one bone joining material 10 is inserted into the cancellous bone 110 of the sternum body 100Y. It is preferable that the longitudinal dimension L is short. One example thereof is approximately half of the longitudinal dimension L of the osteosynthesis material 10 when one osteosynthesis material 10 is inserted into the cancellous bone 110 of the sternum body 100Y.

  In the above embodiment, an example is shown in which the same number of bone cements 10 are inserted into the cancellous bone 110 of the sternum pattern 100X and the cancellous bone 110 of the sternum body 100Y, but the bone inserted into each cancellous bone 110 The relationship of the number of the bonding materials 10 can be arbitrarily changed. In one example, the number of osteosynthesis materials 10 inserted into the cancellous bone 110 of the sternum pattern 100X and the number of osteosynthesis materials 10 inserted into the cancellous bone 110 of the sternum body 100Y are different from each other. In a preferred example, the number of osteosynthesis materials 10 inserted into the cancellous bone 110 of the sternum body 100Y is larger than the number of osteosynthesis materials 10 inserted into the cancellous bone 110 of the sternum pattern 100X. For example, the number of the former is two and the number of the latter is one.

  In the above embodiment, an example is shown in which the same type of osteosynthesis material 10 is inserted into each of the cancellous bone 110 of the sternum pattern 100X and the cancellous bone 110 of the sternum body 100Y, but the bone inserted into each cancellous bone 110 The type relationship of the bonding material 10 can be arbitrarily changed. In one example, the osteosynthesis material 10 is inserted into one of the cancellous bone 110 of the sternum 100X and the cancellous bone 110 of the sternal body 100Y, and another type of osteosynthesis material is inserted into the other. One example of another type of osteosynthesis is the osteosynthesis 200 shown in FIG. The number of osteosynthesis materials 10 inserted into each cancellous bone 110 and other types of osteosynthesis materials can be arbitrarily selected.

  The osteosynthesis material 10 can also be used to join bones other than the sternum.

DESCRIPTION OF SYMBOLS 10: Bone bonding material 11: 1st longitudinal end part 12: 2nd longitudinal end part 13: 1st side part 14: 2nd side part 15: Protrusion 100: Sternum 101: Split surface 110: Sponge bone X: Longitudinal direction Y: Short direction Z: Thickness direction SC: Dividing direction RD: Distance between ribs L: Longitudinal dimension W: Short dimension H: Thickness dimension T: Plate thickness

Claims (14)

An osteosynthesis material that can be inserted into the cancellous bone of a divided bone,
The osteosynthesis has a longitudinal component and a transverse component, the longitudinal component is formed along the bone splitting surface, and the transverse component intersects the bone splitting surface. The formed bone cement. The osteosynthesis material according to claim 1, further comprising at least one protrusion protruding in a short direction of the osteosynthesis material. The bone bonding material according to claim 2, wherein the plurality of protrusions are formed so as to protrude in one and the other in the short direction of the bone bonding material. The osteosynthesis material according to claim 2 or 3, wherein the plurality of protrusions are formed side by side in the longitudinal direction of the osteosynthesis material. The osteosynthesis material according to any one of claims 2 to 4, wherein the shape of the protrusion in a plan view is a surface shape. The osteosynthesis material according to any one of claims 2 to 5, wherein the thickness of the protrusion becomes thinner toward the tip of the protrusion. The bone bonding material according to any one of claims 1 to 6, wherein the shape in a side view is a wave shape. The osteosynthesis material according to claim 1, wherein a thickness of a side portion in the transversal direction of the osteosynthesis material becomes thinner toward an edge in the transversal direction of the osteosynthesis material. The osteosynthesis material according to any one of claims 1 to 8, which has a shape that can be inserted into the cancellous bone of the sternum. The osteosynthesis material according to claim 9, wherein a dimension in a longitudinal direction of the osteosynthesis material is not less than a distance between ribs. The osteosynthesis material according to claim 9 or 10, wherein a dimension in a longitudinal direction of the osteosynthesis material is included in a range of 20 mm to 90 mm. The osteosynthesis material according to any one of claims 9 to 11, wherein a dimension in a short direction of the osteosynthesis material is included in a range of 15 mm to 40 mm. The osteosynthesis material according to any one of claims 9 to 12, wherein a dimension in a thickness direction which is a direction orthogonal to a longitudinal direction of the osteosynthesis material in a side view is included in a range of 0.5 mm to 6.0 mm. . The osteosynthesis material as described in any one of Claims 9-13 in which the plate | board thickness of the said osteosynthesis material is contained in the range of 0.3 mm-3.0 mm.