JP6502161B2 - Bone cement - Google Patents

Description

  The present invention relates to a bone graft material inserted into cancellous bone in order to join split bones.

  In surgical fields such as orthopedics, plastic surgery, thoracic surgery, and brain surgery, when bones are divided by incision etc., a pin-shaped osteosynthesis material is inserted into the cancellous bone exposed on the divided surface of the bone and divided. Bones are joined (see, for example, Patent Document 1).

  As shown in FIG. 15 (a), when the sternum 100 is divided by a midline sternum incision, a dividing surface 101 is formed along the longitudinal direction of the sternum 100. As shown in FIG. 15 (b), approximately half of each of the plurality of bone joints 200 is inserted into one cancellous bone 110 of the divided sternum 100, and the remaining portion of each bone joint 200 is divided. By being inserted into the other cancellous bone 110 of the sternum 100, the sternum 100 is joined by a plurality of bone cements 200.

Patent No. 2969217

  However, even if a plurality of bone cements 200 are inserted into the cancellous bone 110, the division surface 101 may be dislocated during the time 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, the cancellous bone 110 can not support the force applied to the bone cement 200 when the force is applied to the sternum 100, as shown in FIG. It is considered that the posture of the bone joint material 200 with respect to the cancellous bone 110 is changed as exemplified by the two-dot chain line in FIG. Here, the case where the sternum 100 is divided by dissection is referred to as an example, but when bones other than the sternum 100 are divided by dissection and various reasons including the sternum 100 due to reasons other than dissection The same problem may occur when the bone of the bone is divided.

  An object of the present invention is a bone joint material which is hard to move in bone even if it is used in a patient with a low density of trabecular bone in the intrathecal cavity due to osteoporosis etc. It is to provide.

[1] One embodiment of the bone cement according to the present invention is a bone cement insertable into cancellous bone of divided bone, wherein said bone cement comprises a thermoplastic polymer and bioresorbable bioceramic particles It is made of a composite material, the bone joint material has a longitudinal component and a latitudinal component, the longitudinal component is formed along the dividing surface of the bone, and the latitudinal component is the dividing of the bone. It is formed to intersect with the surface, and has a plurality of peaks and a plurality of valleys aligned in the longitudinal direction in a side view seen from the Y direction with the longitudinal direction component as the X direction and the transverse direction component as the Y direction. The shape of the side view is a wave shape by alternately forming the peaks and the valleys adjacent to each other .

When the divided bones are joined by this bone joint material, it is confirmed by the test that displacement of the divided surface of the bone is less likely to occur compared to the case where the divided bones are joined by the pin-shaped bone joint material It was done. Since this bone joint material is inserted into cancellous bone so that the longitudinal direction is along the bone division plane, the division plane may be deviated as compared with the case where a pin-shaped bone joint material is used. It is thought that it is mainly affected that the shearing force is strongly received by the present bone joint material. In addition, when the bone joint material has a longitudinal component, the bone joint material becomes difficult to shift after the bone joint material is inserted into the cancellous bone of the bone. In addition, since cancellous bone intrudes into the recess formed by the wave shape, the position of the bone cement relative to the bone is unlikely to shift due to the anchoring effect.

[2] According to an example of the bone bonding material, at least one protrusion protruding in the lateral direction of the bone bonding material is provided.
According to this bone joint material, since a sharp part is formed by a projection, insertion resistance when bone joint material is inserted in cancellous bone is reduced. Therefore, the bone graft material can be smoothly inserted into the cancellous bone without forming a pilot hole in the cancellous bone.

[3] According to an example of the bone bonding material, a plurality of the protrusions are formed to protrude to one side and the other in the short direction of the bone bonding material.
This bone cement reduces insertion resistance when inserted into cancellous bone. In addition, since the cancellous bone enters between the plurality of projections in each of the one and the other of the divided bones, the position of the bone cement relative to the bone is less likely to shift due to the anchor effect.

[4] According to an example of the bone bonding material, the plurality of projections are formed in line in the longitudinal direction of the bone bonding material.
According to this bone cement, insertion resistance when inserted into cancellous bone is further reduced. In addition, since cancellous bone enters between the plurality of projections, the position of the bone cement relative to the bone is unlikely to shift due to the anchoring effect.

[5] According to an example of the bone bonding material, the shape of the protrusion in plan view is a plane shape.
According to this bone joint material, the shear force to cause the separation surface to be displaced is strongly received by the projection, so that the separation surface of the bone is unlikely to be displaced.

[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 bone joint material, since the tip of the projection is formed sharper, the insertion resistance when the bone joint material is inserted into cancellous bone is further reduced. For this reason, the bone cement can be more smoothly inserted into the cancellous bone without forming a pilot hole in the cancellous bone.

[ 7 ] According to an example of the bone jointing material, the thickness of the lateral side of the bone jointing material becomes thinner toward the lateral edge of the bone jointing material.
According to this bone cement, since the shape in the lateral direction is a tapered shape, insertion resistance when the bone cement is inserted into cancellous bone is reduced. Therefore, the bone graft material can be smoothly inserted into the cancellous bone without forming a pilot hole in the cancellous bone.

[ 8 ] According to an example of the bone cement, it has a shape that can be inserted into cancellous bone of the sternum.
The sternum is frequently affected by breathing and daily activities. When a bone cement having a longitudinal component along the parting surface of the sternum is used for such a part, the bone bonding material strongly receives shear force to cause the parting surface to slip, so the parting It is easy to keep the parting plane of the sternum stable until the restored sternum is restored.

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

[ 10 ] According to an example of the bone bonding material, the dimension in the longitudinal direction of the bone bonding material is included in the range of 20 mm to 90 mm.
When the dimension in the longitudinal direction is 20 mm or more, the divided surface of the sternum is more difficult to shift. When the longitudinal dimension is 90 mm or less, when the bone cement is inserted into the cancellous bone of the divided sternum, the bone cement does not easily come in contact with the cortical bone, and the insertability of the bone cement is further enhanced.

[ 11 ] According to an example of the bone bonding material, the dimension in the short direction of the bone bonding material is included in the 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 cancellous bone is further reduced. When the dimension in the lateral direction is 40 mm or less, the possibility that the projection is strongly pressed against the cortical bone is reduced when the bone cement is inserted into the cancellous bone of the divided sternum.

[ 12 ] According to an example of the bone bonding material, the dimension in the thickness direction which is a direction orthogonal to the longitudinal direction of the bone bonding material 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 divided surface of the sternum is less likely to be displaced. When the dimension in the thickness direction is 6.0 mm or less, when the bone cement is inserted into the cancellous bone of the divided sternum, the bone cement does not easily come in contact with the cortical bone, and the insertability of the bone cement is further enhanced.

[ 13 ] According to an example of the bone bonding material, the thickness of the bone bonding material is included in the range of 0.3 mm to 3.0 mm.
When the plate thickness is 0.3 mm or more, when the bone joint material is inserted into cancellous bone, the bone joint material is less likely to be deformed, and the insertability of the bone joint material 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 reduced, and the bone in which the bone bonding material is inserted is likely to be maintained in a good state.

  According to the above-mentioned bone cement, even if it is used for a patient with a low density of trabecular bone in the intrathecal space due to osteoporosis etc., it is hard to move in the bone, and the division surface of the bone is unlikely to shift.

These are top views of the bone bonding material of embodiment. Is a plan view of the strip. FIG. 2 is a side view of the bone bonding material of FIG. These are top views of a part of bone-connection material of a modification. These are figures regarding the sternum in which the bone-connection material of FIG. 1 was inserted. These are tables showing characteristic data of Samples 1 to 5. Is a graph showing the results of the insertion test using samples 1 and 2. Is a graph showing the results of shear test using Samples 1 and 2. Is a graph showing the results of the insertion test using samples 1 and 3. Is a graph showing the results of shear test using Samples 1 and 3. Is a graph showing the results of the insertion test using samples 3 and 4. Is a graph showing the results of shear test using samples 3 and 4. Is a graph showing the results of the insertion test using samples 3 and 5. Is a graph showing the results of shear test using samples 3 and 5. Is a graph which shows the result of the shear test using samples 1-6. These are perspective views of the bone bonding material of a 1st modification. These are perspective views of the bone bonding material of a 2nd modification. These are perspective views of the bone bonding material of a 3rd modification. Is a figure regarding the sternum to which the conventional bone cement was inserted.

(Embodiment)
FIG. 1 is an example of a bone cement 10 used for joining a sternum that has undergone a midline sternum incision. Fig.5 (a) is a front view of the sternum 100 in which the bone cement 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 in the middle of the sternum, they are divided into a first hemisternal bone 100A and a second hemisternal bone 100B as shown in FIG. 5 (a). As shown in FIG. 5 (b), the cancellous bone 110 is exposed at the split surfaces 101 of the first half sternum 100A of the sternum handle 100X and the first half sternum 100A of the sternum body 100Y. The second half chest 100B of the stalks 100X and the second half chest 100B of the sternum 100Y have the same condition. The bone joint material 10 is cut out from the strip 1 shown in FIG. 2 in accordance with the length of the dividing surface 101 in the dividing direction SC of the sternum 100.

  One example of a material constituting the bone bonding material 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 bioresorbability. is there. An example of high strength implant material is disclosed, for example, in Japanese Patent No. 3239127.

  Examples of bioceramics having surface bioactivity include calcined or uncalcined hydroxyapatite, β-TCP, bioglass-based or crystallized glass-based biomedical glass, and any one of diopside or those Or a mixture of two or more of them.

  Among them, calcined or uncalcined hydroxyapatite, bioglass based bioglass, ceravital, crystallized glass based AW glass ceramics, crystallized glass based biobelit-1, β-crystallised glass, and diop It is believed that the side is more suitable for the bone cement 10.

  Moreover, if it is bioabsorbable bioceramics, not only bioceramics having surface bioactivity, but also bioceramics not having surface bioactivity can be used. As the polymer, a biocompatible crystalline or non-crystalline polymer can be used. Furthermore, since a polymer having biodegradability is absorbed by the living body, a surgery for removing the bone cement 10 after bone fusion is unnecessary, and it is more preferable as a material of the bone cement 10. In general, crystalline polymers have higher mechanical strength than non-crystalline polymers. For this reason, the material of the bone cement 10 can be appropriately selected in consideration of the strength required for each target site into which the bone cement 10 is inserted. Examples of thermoplastic polymers having biodegradability and absorption include polylactic acid and various polylactic acid copolymers. An example of a polylactic acid copolymer is lactic acid-glycolic acid copolymer.

  As shown in FIG. 1, the shape of the bone joint material 10 in a plan view is a band shape having a longitudinal component which is a component of the longitudinal direction X and a latitudinal component which is a component of the latitudinal direction Y Are formed along the dividing surface 101 of the sternum 100 shown in FIG. 5 (a). The first longitudinal end 11 which is one end in the longitudinal direction X of the bone joint material 10 and the second longitudinal end 12 which is the other end have flat end faces. The first side 13 which is one side of the bone bonding material 10 in the short direction Y and the second side 14 which is the other side each have a plurality of projections 15.

  The plurality of projections 15 project in the short direction Y with respect to the center line of the bone joint material 10 along the longitudinal direction X, and are formed in the longitudinal direction X in each of the side portions 13 and 14. The shape of the protrusion 15 in plan view is a planar shape. The projections 15 of the corresponding first side 13 in the longitudinal direction X and the projections 15 of the second side 14 form a set of projections 15 which project in opposite directions in the transverse direction Y. doing.

  The dimension from the root to the tip of the projection 15 (hereinafter referred to as “projection height PL”) corresponds to the base of the projection 15 and the other projection 15 of one of the projections 15 constituting the set of the projections 15 in the bone joint material 10 It is shorter than the dimension of the part between the root. The pitch of the adjacent protrusions 15 in the longitudinal direction X (hereinafter, referred to as “inter-projector distance PP”) is approximately equal to the protrusion height PL.

  A wave shape is formed on each of the side portions 13 and 14 by the plurality of protrusions 15 aligned in the longitudinal direction X in a 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 the protrusions 15 formed on each side 13 and 14 is six. In addition, the shape of the protrusion 15 can be changed into a protrusion shape as is shown by FIG. 4, for example.

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

  The dimensions of each part of the bone cement 10 shown in FIGS. 1 and 3 preferably fall within the following range. The preferred range of the dimension in the longitudinal direction X (hereinafter "longitudinal dimension L") is 20 mm to 90 mm. The preferred range of the dimension in the short direction Y (hereinafter referred to as the “short dimension W”) is 15 mm to 40 mm. A preferred range of the dimension in the thickness direction Z (hereinafter referred to as “thickness dimension H”) which 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 preferably longer than the center-to-center distance (hereinafter, “intercostal distance RD”) of the rib notch 130 adjacent to the dividing direction SC of the sternum 100 in FIG. 5A. The preferable range of the plate thickness T of the bone bonding material 10 is 0.3 mm to 3.0 mm. In one example, the longitudinal 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. Note that the distance between ribs RI is approximately equal to the distance between centers of ribs adjacent in the dividing direction SC.

The procedure for joining the sternum 100 will be described with reference to FIG.
The divided sternum 100 is joined, for example, in the following procedure. First, the first bone graft material 10 is inserted into the cancellous bone 110 of the first half 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 13 and the second side 14 of the first bone cement 10 is inserted into the cancellous bone 110 in which the pilot hole is not formed. And the right side portion of the first bone cement 10 is pushed into the cancellous bone 110 until the length in the lateral direction Y of the right side portion of the first bone cement 10 in the cancellous bone 110 reaches a predetermined length Be

  Next, the right side portion of the second bone cement 10 is inserted into the cancellous bone 110 of the first half sternum 100A of the stalks 100X by the same procedure as described above. When the first bone joint material 10 and the second bone joint material 10 are respectively inserted into the cancellous bone 110, the first bone joint material 10 and the second bone joint 10 in the longitudinal direction of the first half bone 100A. A predetermined distance is formed between the bonding material 10 and the bonding material 10. The longitudinal dimension L of the second bone cement 10 is shorter than the longitudinal dimension L of the first bone cement 10 since the length of the sternum handle 100X in the dividing direction SC is shorter than the length of the sternum 100Y. Is preferred.

  Next, the dividing surface 101 of the second half chest 100B is aligned with the dividing surface 101 of the first half chest 100A. At this time, the left side portion of the first bone joint material 10 and the left side portion of the second bone joint material 10 are respectively inserted into the cancellous bone 110 of the second half sternum 100B. Through these procedures, the sternum 100 is joined by the two bone joints 10 as shown in FIG. 5 (a).

The actions and effects obtained by the bone cement 10 will be described.
The bone joint material 10 is inserted into the cancellous bone 110 so that the longitudinal direction X thereof is along the dividing surface 101 of the sternum 100. For this reason, when a shear force in the vertical or longitudinal direction to cause the dividing surface 101 to shift is applied to the sternum 100, as compared with the case where the sternum 100 is joined by the pin-shaped bone joint material, The shear force is strongly received by the bone joint material 10. For this reason, even when the density of trabeculae of the cancellous bone 110 is low, the division surface 101 does not easily shift.

  Further, when compared with the pin-shaped bone jointing material 200 shown in FIG. 15 (a), the following effects can be obtained. When a shear force is applied to the divided surface 101 of the sternum 100 into which the pin-shaped bone joint material 200 is inserted, the bone joint as shown by a two-dot chain line in plan view of the sternum 100 shown in FIG. The material 200 may rotate relative to the sternum 100. On the other hand, in the bone cement 10 according to the embodiment, the longitudinal component of the bone cement 10 along the dividing surface 101 is longer than the lateral component of the bone cement 10 intersecting the dividing surface 101 of the sternum 100. It is hard to rotate with respect to the sternum 100 when a shearing force is applied to the parting surface 101 of.

According to the bone cement 10, the following effects can be obtained.
(1) A plurality of projections 15 are formed on each side portion 13, 14. According to this configuration, when the bone cement 10 is inserted into the cancellous bone 110 of the first half sternum 100A or the second half sternum 100B, the sharp portion of the protrusion 15 first contacts the cancellous bone 110. The insertion amount of the projection 15 into the cancellous bone 110 gradually increases. For this reason, the insertion resistance when the bone joint material 10 is inserted into the cancellous bone 110 is not applied at one time, but dispersed at the time of insertion, which facilitates the insertion. In addition, since the cancellous bone 110 enters between the plurality of projections 15 in a state in which the bone joint material 10 is sufficiently inserted into the cancellous bone 110, the position of the bone joint material 10 with respect to the sternum 100 is unlikely to shift due to the anchoring effect.

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

  (3) When the density of trabeculae in the intrathecal space of the sternum 100 is low due to osteoporosis or the like, the trabeculae show uneven distribution in a cross section which is a cross section orthogonal to the longitudinal direction of the sternum 100. The density of trabeculae is lower the closer to the central part of cancellous bone 110 which is the central part of the cross section, and the density of trabecular bone is higher the closer to cortical bone 120. When bone joint material 10 having a wave shape in side view is used for joining of such a sternum 100, not only the central portion of cancellous bone 110 with low density of trabecular bone but also high density of trabecular bone Since the bone cement 10 is also inserted into a portion near the cortical bone 120, the sternum 100 is firmly fixed by the bone cement 10, and the stability of the sternum 100 is enhanced.

  (4) The force acts on the sternum 100 frequently due to the action of breathing and daily life. When the bone joint material 10 having the longitudinal direction X along the dividing surface 101 of the sternum 100 is used for such a portion, the shearing force to cause the dividing surface 101 to be shifted is stronger by the bone joint material 10 As it is received, the dividing surface 101 of the sternum 100 is likely to be kept stable until the divided sternum 100 is restored.

  (5) The longitudinal dimension L of the bone joint material 10 is equal to or greater than the distance between rib ribs RD. According to this configuration, the parting surface 101 of the sternum 100 is less likely to be displaced than in the case where the longitudinal dimension L is less than the distance between the ribs RD. The reason is considered as follows. As shown in FIG. 5A, the width of the sternum 100 is narrow in the valley portion between the radial incisions 130, so the protrusion 15 of the bone cement 10 inserted into the sternum 100 is a portion near the cortical bone 120. To reach. The portion near the cortical bone 120 is high in strength due to the high density of trabeculae as described above. For this reason, the protrusion 15 which reached the part near the cortical bone 120 is firmly supported, and the bone cement 10 does not easily move with respect to the sternum 100. For this reason, the bone joint material 10 is hard to rotate around the axis along the longitudinal direction of the body.

  (6) The longitudinal dimension L of the bone joint material 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 less likely to be displaced. When the bone joint material 10 is inserted into the cancellous bone 110 of the first half sternum 100A or the second half sternum 100B when the longitudinal dimension L is 90 mm or less, the bone joint material 10 does not easily hit the cortical bone 120, and the bone is joined The insertability of the material 10 is further enhanced.

  (7) The short dimension W of the bone joint material 10 is included in the range of 15 mm to 40 mm. When the short dimension W is 15 mm or more, the divided surface 101 of the sternum 100 is less likely to be displaced because the area of the bone joint material 10 which receives the shear force acting on the sternum 100 is large. When the short dimension W is 40 mm or less, the protrusion 15 may be strongly pressed against the cortical bone 120 when the bone cement 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 joint material 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 parting surface 101 of the sternum 100 joined by the bone joint material 10 is further less likely to be displaced. When the thickness dimension H is 6.0 mm or less, when the bone cement 10 is inserted into the cancellous bone 110 of the first half sternum 100A or the second half sternum 100B, the bone cement 10 does not easily hit the cortical bone 120 The insertability of the bone cement 10 is further enhanced.

  (9) The plate thickness T of the bone joint material 10 is included in the range of 0.3 mm to 3.0 mm. When the thickness T is 0.3 mm or more, when the bone joint material 10 is inserted into the cancellous bone 110, the bone joint material 10 is less likely to be deformed, and the insertability of the bone joint material 10 is further enhanced. When the thickness T is 3.0 mm or less, the amount of the bone bonding material 10, which is a foreign body to the human body, is reduced to be inserted into the sternum 100, so the chest 100 with the bone bonding material 10 inserted is maintained in a good state. Cheap.

(Example)
The inventor of the present application has carried out an insertion test for confirming the relationship between the characteristic specifications of the bone cement 10 and the insertability of the bone cement 10 into cancellous bone, and the characteristic specifications of the bone cement 10. A shear test was conducted to confirm the relationship between the and the shear strength of the bone joint material 10. The characteristic specifications of the bone joint material 10 are the thickness dimension H, the number of the protrusions 15, the protrusion height PL, the shape of the protrusions 15, the distance PP between protrusions, and the longitudinal dimension L. Samples 1 to 5 shown in FIG. 6 were used in this test. The sample 1 is the bone bonding material 10 exemplified in the above embodiment. The "triangle" described in the column of "the shape of a protrusion" of FIG. 6 means the triangle shape of the protrusion 15 shown by FIG. 1 etc., and the "protrusion" means the protrusion shape shown by FIG.

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

  The test machine used is autograph AG-20 kNXD (manufactured by Shimadzu Corporation). The insertion test was performed in the following procedure. First, the sternum model was set on the fixture of the tester, and the sample was set on the movable fixture of the tester. Next, the movable jig was moved at a constant speed with respect to the fixed jig so that the projection 15 of the sample was inserted into the cancellous bone cell block. Next, the movable jig was stopped when the length (hereinafter, “insertion displacement”) of the bone joint material 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. The predetermined insertion displacements are four types of 3 mm, 5.25 mm, 9.0 mm, and 11 mm. The tester detected the 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, in addition to samples 1 to 5, sample 6 was also used. The sample 6 is a pin-type bone bonding material 200 shown in FIG. The bone joint 200 has a thickness of 3.0 mm and a longitudinal dimension of 45.5 mm. The sternum model and tester used are similar to the insertion test. However, in the shear test, two sternum models were used. The shear test was performed in the following procedure. First, the sample was inserted into the cancellous 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 insertion displacement of the sample for each sternum model is substantially identical. These operations constitute a sternum model in which the divided surfaces are joined by the sample. Next, one sternum model was set to the fixing jig of the testing machine, and the other sternum model was set to 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 shear force was applied to the sample. Next, the movable jig was stopped when the amount of movement of the movable jig with respect to the fixed jig (hereinafter, “shear displacement”) reached a predetermined shear displacement. The moving speed of the movable jig is 10 mm / min. The predetermined shear displacement is four types of 0.5 mm, 1.0 mm, 1.5 mm, and 3.0 mm. The tester detected the 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 contrasting the results of the insertion test for samples 1 and 2. FIG. 7B is a graph contrasting the shear test results for 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 joint material 10 becomes higher and the shear strength decreases. The insertability of the bone joint material 10 is considered to be related to the increase in sharpness of the tip of the protrusion 15 as the thickness dimension H becomes longer. The shear strength is considered to be related to the area under shear load becoming smaller as the thickness dimension H becomes longer.

  FIG. 8A is a graph contrasting the results of the insertion test for samples 1 and 3. FIG. 8B is a graph contrasting the shear test results for 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 joint material 10 increases and the shear strength does not show a significant change with respect to the change in the number of the protrusions 15.

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

  FIG. 10A is a graph contrasting the results of the insertion test for samples 3 and 5. FIG. 10B is a graph contrasting the shear test results for Samples 3 and 5. From these test results, it can be confirmed that the insertability of the bone joint material 10 is enhanced and the shear strength is reduced when the shape of the protrusion 15 is a protrusion as compared with the case of a triangular shape. The insertability of the bone joint material 10 is considered to be related to the fact that the tip end of the projection 15 having the projection shape is sharper than the tip end of the projection 15 having the triangular shape. With regard to the shear strength, it is considered that when the tip of the projection 15 is in the form of a protrusion, the area receiving the shear load is smaller than in the case where the tip of the projection 15 is in the shape of a triangle. .

  As shown by the results of the insertion test and the shear test, the insertability is improved as the sharpness of the tip of the projection 15 is increased, and the shear strength is improved as the surface area of the bone joint material 10 is increased. Based on this relationship, it is obtained by the bone cement 10 by selecting the specific contents of the characteristic items of the bone cement 10 according to the type of bone to be joined and the condition of the bone such as the bone density. It is believed that the effect of

  FIG. 11 is a graph contrasting the shear test results for Samples 1-6. From this test result, it can be confirmed that the shear strength of the bone joint material 10 is higher than the shear strength of the pin-type bone joint material 200 when the shear displacement is 1.5 mm and 3.0 mm. The tendency is more pronounced when the shear displacement is 3.0 mm. These test results are considered to be related to the fact that the bone joint material 10 has a larger area subjected to a shear load as compared with the pin-type bone joint material 200.

(Modification)
The description of the above embodiment is an illustration of possible forms of the bone bonding material according to the present invention, and is not intended to limit the form. The bone bonding material according to the present invention may take a form in which, for example, the modification of the embodiment described below, and at least two modifications not inconsistent with each other are combined, in addition to the above-described embodiment.

The shape of the side portion of the bone cement 10 can be arbitrarily changed.
FIG. 12 shows a first modification in which the shape of the side portion of the bone cement 10 is changed. The bone cement 10 of this modification includes a pin 16 formed at the first longitudinal end 11 and a pin 16 formed at the second longitudinal end 12. Each pin 16 protrudes in one and the other of the transverse direction Y with respect to the center line of the bone joint material 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 bone bonding material 10 of this modification is provided with a pin 16 having substantially the same shape as the two pins 16 shown in the first modification at an intermediate portion in the longitudinal direction X.

  FIG. 14 shows a third modification in which the shape of the side portion of the bone joint material 10 is changed. The bone bonding material 10 of this modification has a configuration in which all the protrusions 15 are omitted from the bone bonding material 10 of the embodiment shown in FIG. 1. In the fourth modification, the shape in a side view of the bone bonding material 10 of the third modification is changed from a wave shape to a flat shape. In the fifth modification, in the third modification or the fourth modification, the thickness of the first side 13 and the second side 14 of the bone cement 10 toward the edge in the short direction Y T becomes thinner. 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 latitudinal direction Y, A fifth modification of the bone bonding material 10 is obtained. According to this configuration, insertion resistance when the bone cement 10 is inserted into the cancellous bone 110 is reduced. When the bone bonding material 10 includes the pins 16 as in the first and second modifications, the number can be changed to one or four or more.

The shape of the protrusion 15 in a 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 cement 10 in a plan view can be arbitrarily changed. An example of the shape in plan view is a triangular shape, a trapezoidal shape, a rhombus shape, an oval shape, and an oval shape. When the bone joint material 10 does not include the projections 15, the above-described shapes are formed by the edge of the bone joint material 10, and when the bone joint material 10 includes a plurality of projections 15, the tip of each projection 15 described above Each shape is formed.

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

  The shape of the bone cement 10 in a side view can be arbitrarily changed. An example of the shape of the side view is a triangular wave, a sawtooth wave, a rectangular wave, and wave shapes similar to these, and wave shapes having irregular changes. In another example, the shape in side view is not a wave shape but a flat 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 short direction Y.

  -In bone joint material 10 of an embodiment, although thickness dimension H in each mountain 10A is set up uniformly, thickness dimension H can be set up for every mountain 10A. In one example, two types of ridges 10A having different thickness dimensions H are alternately formed in the longitudinal direction X of the bone cement 10. In another example, the plurality of peaks 10A are formed such that the thickness dimension H gradually increases from one side of the first longitudinal end 11 to the other side of the second longitudinal end 12. In yet another example, the thickness dimension H is gradually increased or decreased from the first longitudinal end 11 and the second longitudinal end 12 toward the central portion in the longitudinal direction X of the bone cement 10. A mountain 10A is formed.

  The shape of the band 1 in side view can be arbitrarily changed. In one example, the first mountain 10A and the second mountain 10A having different thickness dimensions H are formed in one band 1 (see FIG. 2). An example of the height of the first mountain 10A is 3 mm, and an example of the height of the second mountain 10A is 5 mm. The band 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 bone cements 10 having different thickness dimensions H from one band 1, ie, bone cements 10 including one or more first piles 10A, and one or more bone cements 10 The bone cement 10 including the second mountain 10A can be cut out. Further, by cutting the band 1 so as to include the boundary between the first portion and the second portion in the band 1, one or more of the first peaks 10A and one or more of the second peaks 10A. Can be cut out. Therefore, the thickness dimension H of the bone cement 10 can be selected in accordance with the shape of the sternum 100 and the like for each patient. An example of the use form which selects thickness dimension H is shown below.

  The thickness of the cancellous bone 110, which is the thickness of the medullary cavity, may differ from each other in the upper and lower portions 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 . If it is one bone joint material 10 containing the 1st pile 10A and the 2nd pile 10A, it can insert over the upper part and the lower part of such a sternum 100. As shown in FIG. In that case, the first mountain 10A is inserted under the sternum 100 which is a thin portion of the cancellous bone 110, and the second mountain 10A is inserted into the upper portion of the sternum 100 which is a thick portion of the cancellous bone 110. Therefore, the bone cement 10 can be easily inserted into the sternum 100, and 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 can be Such force is strongly received by the cortical bone 120.

The thickness T of the projection 15 can be arbitrarily changed. In one example, the thickness T of the protrusion 15 decreases as it goes from the root of the protrusion 15 to the tip.
The longitudinal dimension L of the bone joint material 10 can be arbitrarily changed. In one example, the longitudinal dimension L is less than the distance between ribs RD. In another example, the longitudinal dimension L is greater than the distance between ribs RD.

-In the above-mentioned embodiment, although bone attachment material 10 is cut out from band object 1, bone attachment material 10 can take the form separately formed.
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 bone joints 10 inserted into the cancellous bone 110 of the sternum 100Y can be arbitrarily changed. In one example, two or three bone cements 10 are inserted into cancellous bone 110 of sternum body 100Y. In addition, the number of bone joints 10 to be inserted into the cancellous bone 110 of the stalks 100X can be similarly changed.

  -Although the example in which the bone cement 10 was inserted in each of the cancellous bone 110 of sternum stoma 100X and the cancellous bone 110 of sternum body 100Y is shown in the said embodiment, insertion of the bone cement 10 to 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 stalks 100X and the cancellous bone 110 of the sternal body 100Y. For example, when the bone cement 10 is inserted into the cancellous bone 110 of the sternum body 100Y and the bone cement 10 is not inserted into the cancellous bone 110 of the sternum 100X, the bone cement 10 of the bone cement 10 inserted The number can be arbitrarily selected. In a preferred example, the number is one or two. When two bone cements 10 are inserted into the cancellous bone 110 of the sternum body 100Y, compared with the case where one bone cement 10 is inserted into the cancellous bone 110 of the sternum body 100Y, the bone cement 10 Preferably, the longitudinal dimension L of the One example is approximately half of the longitudinal dimension L of the bone cement 10 when one bone cement 10 is inserted into the cancellous bone 110 of the sternum body 100Y.

  -Although the example in which the same number of bone cements 10 were inserted in each of cancellous bone 110 of sternum stoma 100X and cancellous bone 110 of sternum body 100Y is shown in the said embodiment, the bone inserted in each cancellous bone 110 The relationship of the number of bonding members 10 can be arbitrarily changed. In one example, the number of bone joints 10 inserted into the cancellous bone 110 of the stalks 100X and the number of bone joints 10 inserted into the cancellous bone 110 of the sternum 100Y are different from each other. In a preferred example, the number of bone joints 10 inserted into the cancellous bone 110 of the sternum body 100Y is greater than the number of bone joints 10 inserted into the cancellous bone 110 of the sternum stoma 100X. For example, the number of the former is two, and the number of the latter is one.

  -Although the example in which the same kind of bone cement 10 was inserted in each of cancellous bone 110 of sternum stoma 100X and cancellous bone 110 of sternum body 100Y is shown in the above-mentioned embodiment, the bone inserted in each cancellous bone 110 The relationship between the types of bonding material 10 can be arbitrarily changed. In one example, the bone cement 10 is inserted into one of the cancellous bone 110 of the stalks 100X and the cancellous bone 110 of the sternum 100 Y, and another type of bone cement other than the bone cement 10 is inserted into the other. An example of another type of bone cement is bone cement 200 shown in FIG. The number of bone joints 10 and other types of bone joints inserted into each cancellous bone 110 can be arbitrarily selected.

  The bone cement 10 can also be used to join bones other than the sternum.

Reference Signs List 10: bone joint material 11: first longitudinal end 12: second longitudinal end 13: first side 14: second side 15: projection 100: sternum 101: dividing surface 110: cancellous bone X: Longitudinal direction Y: Transverse direction Z: Thickness direction SC: Division direction RD: Distance between ribs L: Longitudinal dimension W: Transverse dimension H: Thickness dimension T: Sheet thickness

Claims (13)

An osteosynthesis material that can be inserted into cancellous bone of divided bones,
The bone bonding material is composed of a composite material of a thermoplastic polymer and bioabsorbable bioceramic particles,
The bone cement has a longitudinal component and a latitudinal component, the longitudinal component being formed along the dividing surface of the bone, and the lateral component intersecting the dividing surface of the bone Formed
When the longitudinal component is in the X direction and the lateral component is in the Y direction, it has a plurality of peaks and valleys aligned in the longitudinal direction in a side view as viewed from the Y direction, and the peaks and valleys are alternately adjacent A bone bonding material having a corrugated shape in the side view by being formed to fit . The bone joint material according to claim 1, further comprising at least one protrusion protruding in the lateral direction of the bone joint material. The bone joint material according to claim 2, wherein a plurality of the protrusions are formed to protrude to one side and the other side in the short direction of the bone joint material. The bone joint material according to claim 2 or 3, wherein a plurality of the projections are formed in the longitudinal direction of the bone joint material. The bone joint material according to any one of claims 2 to 4, wherein a shape of the protrusion in a plan view is a plane shape. The bone bonding 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 joint material according to claim 1, wherein a thickness of a lateral side of the bone joint material decreases toward a lateral edge of the bone joint material. The bone graft material according to any one of claims 1 to 7, which has a shape that can be inserted into cancellous bone of a sternum. The bone joint material according to claim 8, wherein the dimension in the longitudinal direction of the bone joint material is equal to or greater than the distance between ribs. The bone joint material according to claim 8 or 9, wherein a dimension in a longitudinal direction of the bone joint material is included in a range of 20 mm to 90 mm. The bone joint material according to any one of claims 8 to 10, wherein the dimension in the short direction of the bone joint material is included in a range of 15 mm to 40 mm. The bone joint material according to any one of claims 8 to 11, wherein a dimension in a thickness direction which is a direction orthogonal to the longitudinal direction of the bone joint material in a side view is included in a range of 0.5 mm to 6.0 mm. . The bone bonding material according to any one of claims 8 to 12, wherein a thickness of the bone bonding material is included in a range of 0.3 mm to 3.0 mm.