JP2006230787A - Artificial bone fixing structure and fixing tool used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an artificial bone fixing structure capable of fixing an artificial bone and a living bone by a simple operation, obtaining sufficient fixing force, keeping it, and arbitrarily selecting a fixing position further, and a fixing tool used for the same. <P>SOLUTION: The artificial bone fixing structure is a structure for fixing the artificial bone to the living bone by using the fixing tool. The fixing tool is composed of (a) a screw member screw-fitted to the artificial bone and the living bone and (b) a bridge member fixed at both ends with the screw member for connecting the artificial bone and the living bone. Prior to the screw-fitting of the screw member to the artificial bone, an opening is formed beforehand on the artificial bone, and a buffer member having a cylindrical shape as a whole and a through-hole in the center, an expansion part divided at least into three on the distal end part and a flange part on the rear end part is inserted into the opening and tentatively fixed to the opening. Then, the screw member is screwed into the center through-hole of the buffer member, the expansion part at the distal end is expanded to be larger than an opening diameter and it is fixed to the opening so as not to be detached. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fixing structure for fixing an artificial bone to a defect part of a living bone and a fixing structure used therefor, and in particular, a fixing structure for fixing an artificial bone and a living bone using a screw, and The present invention relates to a fixing jig to be used.

  When a part of a living bone is lost due to self or disease treatment, an artificial bone is used as a substitute member. The artificial bone is made of a ceramic that is hard and has high biosafety.

  When fixing a living bone, screwing with a screw is generally used. Fixing is performed by forming an opening having an appropriate size and depth at a predetermined position of the living bone, and screwing the opening into the opening. Usually, the inner diameter of the opening is slightly smaller than the outer diameter of the screw, and when the screw is screwed in, the inner wall of the opening is slightly cut at the crest of the screw to advance the screw and the living body. The bone can be firmly fixed.

  However, when using an artificial bone, there are some problems in screw fixing by a technique similar to that of a living bone. First, since the material used for the artificial bone is not elastic like a living bone, there is a risk of cracking and breaking while the screw is screwed in. However, the screw may loosen over a long period of time. Next, the artificial bone cutting powder generated by screwing in the screw may have some influence on the living body. In particular, it is considered that the influence of cutting powder cannot be ignored when an artificial bone is fixed to the skull.

Therefore, various fixing methods have been proposed in place of the screw fixing method. In particular, as a method for fixing the skull, the following methods are known.
The first method is a suture fixing method using sutures. A plurality of small openings are formed at positions corresponding to the artificial bone and the living bone, and the corresponding openings are sutured and fixed with sutures such as nylon thread and silk thread.
The second method is an adhesive fixing method in which a gap between an artificial bone and a living bone is bonded using a living body adhesive such as bone cement.

The third method is a clamp fixing method in which two circular metal plates are used for fixing. One metal plate is placed outside the skull and the other metal plate is placed inside the skull, and the metal plates are joined by a post. Since the post is arranged so as to pass through the boundary between the artificial bone and the living bone, the edge of the artificial bone and the living bone are placed between the two metal plates by tightening the post and bringing the metal plate closer to each other. Can be inserted to fix the artificial bone.
Special Table 2000-505323

The fourth method is a metal plate fixing method in which a belt-like metal plate and a screw are used in combination. The artificial bone is formed with a slot through which the metal plate is inserted and an engagement structure portion that engages with one end of the metal plate. The metal plate is fixed to the artificial bone by engaging one end thereof with the engaging structure portion of the artificial bone and inserting the intermediate portion into the slot. The other end of the metal plate extends in the direction of the living bone, and the metal plate is screwed to the surface of the living bone using a screw hole formed at the other end.
JP 2000-135220 A

However, these fixing methods have the following problems.
In the first suture fixing method, the fixing force per place is small depending on the strength of the thread. Therefore, in order to obtain a stable fixation, it is necessary to sew a large number of locations, and accordingly, it is necessary to form a large number of stitching holes, which takes time. In addition, since stitching between bones is a relatively complicated task, stitching at multiple locations increases both the burden on the operator and the burden on the patient due to the extension of the operation time.

  In the second adhesive fixing method, the adhesive is fixed by polymerizing a paste in which the monomer and the polymerization initiator are turbid, but the monomer may remain somewhat even after the fixing is completed. It required strict attention. Further, when the artificial bone needs to be removed and re-fixed by re-operation, it is difficult to completely remove the adhesive attached to the living bone, which may cause a problem at the time of re-fixing.

  In the third clamp fixing method, since the metal plate arranged inside the skull is in direct contact with the dura mater, the dura mater may be damaged by the metal plate during and after the fixing operation. Further, when the thickness of the artificial bone and the living bone are different, there is a problem that a sufficient fixing force cannot be obtained.

  In the fourth metal plate fixing method, a relatively large slot must be formed in accordance with the width of the metal plate, and there is a problem in that the fixing location is limited.

  Therefore, the present invention can fix an artificial bone and a living bone with a simple operation, is suitable for fixing a skull, can be sufficiently fixed and can be sustained, and further has a shape of a living bone. The present invention also provides an artificial bone fixing structure in which a fixing position can be arbitrarily selected and a fixing jig used therefor.

  The present invention is a structure for fixing an artificial bone to a living bone using a fixing jig, and the fixing jig is fixed to both ends of the screw member by screwing the artificial bone and the living bone, And a bridging member for connecting the artificial bone and the living bone. Prior to screwing the screw member onto the artificial bone, an opening is formed in the artificial bone in advance, and a buffer member is inserted into the opening. The buffer member has a cylindrical shape as a whole, has a through hole in the center, and has an inflated portion divided at least at the tip portion and a flange portion at the rear end portion. The buffer member is temporarily fixed by being inserted into the opening of the artificial bone, and the screw-member is screwed into the central through-hole of the buffer member so that the tip inflated portion is expanded from the opening diameter of the artificial bone opening. It is secured to the part.

  The present invention is a fixing jig for use in the artificial bone fixing structure described above, wherein a screw member to be screwed to the artificial bone and the living bone, both ends are fixed by the screw member, and the artificial bone and the living bone are connected. And a buffer member interposed between the artificial bone and a screw member screwed to the artificial bone. The shock-absorbing member has a cylindrical shape as a whole, has a through-hole in the center, has an inflated portion divided at least at the tip portion, and a flange portion at the rear end portion, and has a pre-formed artificial bone opening. By inserting the buffer member into the buffer member, the buffer member can be temporarily fixed to the opening, and then the screw member is screwed into the central through-hole of the buffer member to expand the tip inflating part beyond the opening diameter of the opening. The shock-absorbing member can be secured to the opening.

  In the artificial bone fixing structure of the present invention, the artificial bone and the living bone can be coupled by inserting the buffer member and screwing, so that it is possible to obtain a very simple and stable fixing force. . Since the cutout portion is formed in the bulging portion of the buffer member, when the buffer member is inserted into the artificial bone, the outer diameter of the bulge portion can be slightly reduced to pass through the opening, When the bulging portion protrudes from the opening, the outer diameter of the bulging portion returns to the original size, so that the bulging portion having an outer diameter slightly larger than the inner diameter of the opening engages with the edge of the opening. As a result, since the buffer member does not fall out from the opening of the artificial bone while the artificial bone screw is screwed in, the screwing operation is facilitated, and the artificial bone screw can be fixed after screwing. There is an advantage that can be sure. Further, when the artificial bone is removed by re-operation or the like, it can be easily taken out only by removing the screw.

  Since the artificial bone fixing structure of the present invention can perform the operations of inserting the buffer member and screwing all from the surface side of the skeleton, it is suitable for the skeleton where only the surface side is exposed like a skull. Can be used. In addition, if the length of the screw is appropriately selected, there is no metal member protruding on the back side of the skeleton, so there is no risk of damaging the dura mater, brain, etc. if it is an organ adjacent to the back side of the skeleton, such as a skull. .

  In the artificial bone fixing structure of the present invention, the flange of the cushioning member is usually located on the surface side of the artificial bone, and the bridging member is arranged on the flange and fixed with the screw. Are not in direct contact with each other, and generation of wear powder between the artificial bone and the bridging member can be suppressed.

  Furthermore, a large number of openings for exudate are formed in a normal skull artificial bone, but the artificial bone fixing structure of the present invention can fix the artificial bone using the openings. There is no need to separately form an opening in the artificial bone for fixation, and the fixing position can be determined relatively freely by selecting the opening when actually fixing the artificial bone.

  Since the artificial bone fixing jig of the present invention is suitably used for the artificial bone fixing structure according to the present invention, by using the fixing jig of the present invention, the artificial bone fixing jig can also be used for a procedure for fixing the artificial bone to a part of the skull. Suitable, there is an effect that the artificial bone can be stably fixed in the long term and the fixing position can be selected relatively freely.

  The artificial bone fixing structure of the present invention is a structure for fixing an artificial bone to a living bone using a fixing jig, and the fixing jig includes: (a) a screw member screwed onto the artificial bone and the living bone; (B) the both ends are fixed by a screw member, and a bridging member for connecting the artificial bone and the living bone, and prior to screwing the screw member to the artificial bone, the artificial bone has an opening formed in advance, A buffer member having a cylindrical shape as a whole, a through-hole at the center, an expansion portion divided into at least three at the front end portion, and a flange portion at the rear end portion is inserted into the opening portion. Then, the screw member is screwed into the central through hole of the buffer member, and the tip inflated portion is expanded from the opening diameter to be secured to the opening.

  In this artificial fixing structure, the artificial bone fixing jig of the present invention can be used. The fixing jig includes (a) a screw member that is screwed onto the artificial bone and the living bone, (b) a bridging member that is fixed at both ends by the screw member and connects the artificial bone and the living bone, and (c) the artificial bone. And a screw member that is screwed to the artificial bone, and has a cylindrical shape as a whole, a through hole at the center, and an inflated portion and a rear end portion that are divided into at least three at the tip portion And a buffer member provided with a flange portion, and the buffer member can be temporarily fixed to the opening portion by inserting the buffer member into the pre-formed artificial bone opening portion, and then the screw member is placed in the center of the buffer member. The buffer member can be secured to the opening by being screwed into the through-hole and expanding the tip expansion portion beyond the opening diameter of the opening.

  The artificial bone fixing structure 1 of the present invention is a structure in which an artificial bone 8 and a living bone 9 are connected by an artificial bone fixing jig 11 as shown in FIG. The artificial bone fixing jig 11 includes a bridging member 5 called a plate, screws 31 and 41, and a buffer member 2. The plate 5 inserts the artificial bone screw 31 and the living bone screw 41 into the screw holes 52 formed on both sides thereof, and the artificial bone screw 31 and the living bone screw 41 are respectively inserted into the artificial bone 8 and the living bone. It is fixed by screwing to 9. In the artificial bone 8, the artificial bone screw 31 is fixed via the buffer member 2, and in the living bone 9, the living bone screw 41 is directly screwed in and fixed. The buffer member 2 is inserted into the opening 81 of the artificial bone 8 and is supported inside the opening 81 by the flange portion 21 and the bulging portion 22 of the buffer member 2.

  As shown in FIGS. 2A and 2B, the buffer member 2 includes a cylindrical insertion portion 23, a flange portion 21 formed at one end 231 thereof, and a bulging portion 22 formed at the other end 232. And are integrally formed. The bulging portion side end portion 232 and the bulging portion 22 of the insertion portion 23 are equally divided into four by four cut portions 25, and the outer diameter of the bulging portion 22 is slightly reduced by the stress from the outside. It is possible to reduce to. A through hole 24 is formed in the insertion portion 21 along the longitudinal direction of the insertion portion 23, and both end portions thereof are open to the outside.

  The shape dimension of the insertion portion 23 of the buffer member 2 is determined in accordance with the shape dimension of the opening 81 of the artificial bone 8. In the case where the opening 81 is cylindrical, the insertion portion 23 is preferably cylindrical, and the outer diameter is preferably slightly smaller than the inner diameter of the opening 81, and the insertion portion 23 is formed in the opening 81. Can be inserted smoothly. The length of the insertion portion 23 is preferably about the same as or slightly longer than the thickness of the artificial bone 8, and the buffer member can be prevented from rattling after insertion.

  The flange portion 21 of the buffer member 2 is circular in FIG. 2, but is not limited to this, and can be formed in an arbitrary shape. Since the flange portion 21 has a function of preventing the plate 5 from coming into direct contact with the artificial bone 8, it is preferable that the flange portion 21 is appropriately changed according to the shape of the plate 5. If the thickness 21t of the flange portion 21 is too thick, there is a problem that the plate 5 is lifted or the artificial bone is buried. If it is too thin, the flange portion 21 is compressed after the artificial bone screw 31 is tightened. May come into contact with the artificial bone 8. Therefore, the thickness 21t of the flange portion 21 is preferably set as appropriate in accordance with the thickness and fixing portion of the artificial bone 8 to be fixed and the compressibility of the material to be formed.

  The bulging portion 22 of the buffer member 2 is formed in order to prevent the buffer member 2 from dropping after being inserted into the opening 81 of the artificial bone 8. The bulging portion 22 engages with the rear surface side edge portion of the opening portion 81 by projecting to the back surface side of the opening portion 81. Thereby, it becomes difficult for the buffer member 2 to come out of the opening 81. Therefore, the outer diameter of the bulging portion 22 must be larger than the inner diameter of the opening portion 8. However, if the dimensional difference is too large, it is difficult to allow the bulging portion 22 to be inserted into the opening 8, which is not preferable.

  At least three buffer member 2 cut portions 25 are formed. When the number of the cut portions 25 is two or less, the outer diameter of the bulge portion 22 is difficult to reduce, and it is necessary to push the bulge portion 22 with a relatively strong force when inserting the bulge portion 22 into the opening 81 of the artificial bone 8. This is not preferable because unnecessary stress is applied to the artificial bone 8 and the buffer member 2. In particular, the number of the incisions 25 is preferably 3 to 6, and the buffer member 2 can be easily inserted into the opening 81 of the artificial bone 8, and the bulging part 22 is engaged with the outside of the opening 81 after the insertion. During joining, the inconvenience that the bulging portion 22 contracts with a slight force and comes out of the opening 81 is unlikely to occur. However, depending on the material of the buffer member 2, the number of cut portions can be changed. For example, when the buffer member 2 is formed of a hard material, the bulging portion 22 is less likely to be reduced in diameter. In some cases, it is preferable to form 7 or more.

  The through hole 24 of the buffer member 2 is configured by a curved inner wall 243 that is not threaded. Usually, the inner diameter of the through hole 24 is made smaller than the outer diameter 3d of the artificial bone screw 3. The inner wall 243 of the through hole 24 is formed with a screw groove on the inner wall 243 by screwing the artificial bone screw 3 into the through hole 24. Thereby, the inner wall 243 and the outer surface of the artificial bone screw 3 can be brought into close contact with each other.

  Further, the through hole 24 is preferably reduced in diameter from the inner diameter 241d on the flange portion 21 side toward the inner diameter 242d on the bulge portion side. Since the cut portion 25 is formed in the bulging portion side end portion 232 of the insertion portion 22, the buffer member 2 opens the artificial bone 8 when stress is applied to reduce the diameter of the bulging portion 22 inward. There is a risk of dropping from the portion 81. When the artificial bone screw 3 is screwed into the through-hole 24 by reducing the inner diameter 242d of the through-hole 24 on the bulging portion side, a stress that pushes the bulging portion 22 outward is generated and buffered from the opening 81. It is possible to effectively suppress the member 2 from falling off. Further, it is preferable because the force required for screwing the artificial bone screw 3 can be reduced as compared with the case where the through-hole 24 is entirely reduced in diameter.

  Since the buffer member 2 is used in the body for a long period of time, it must be formed of a material having wear resistance and biosafety. Furthermore, the properties of the material required by the method of using the cushioning member 2 in the present invention are as follows: (1) When the bulging portion 22 is inserted into the opening 81 of the artificial bone 8, the diameter can be reduced, and the bulging portion 22 is opened. (2) When the artificial bone screw 3 is screwed into the through hole 24, the screw 3 can be screwed to form a screw groove on the inner wall 243 of the through hole. And the hardness which can be held to the extent that the screw 3 does not fall off, and (3) when the artificial bone screw 3 is screwed in and the plate 5 compresses the flange portion 21, the thickness 21t of the flange portion 21 does not become extremely small. It has properties such as compression deformation. Ultrahigh molecular weight polyethylene (UHMWPE), which is a currently known plastic with high biological safety, has the above properties and can be preferably used as a material for the buffer member 2.

  As shown in FIG. 3, the artificial bone screw 3 and the living bone screw 4 are different in the shapes of the tip portions 32 and 42 thereof. The tip 41 of the living bone screw 41 is pointed so that the living bone 9 can be screwed in while being threaded. On the other hand, the artificial bone screw 3 is screwed into the through-hole 24 of the buffer member 2 and screwed into the through-hole inner wall 243 of the buffer member 2, so that the distal end portion 31 does not need to be sharp and preferably Is rounded. The artificial bone 8 may be thinner than the living bone, and when a screw having the same tip shape as that of the living bone screw 4 is used, the sharp tip protrudes from the back surface of the artificial bone 8, and the skeleton Risk of damage to internal organs. Therefore, it is preferable that the distal end portion 31 of the artificial bone screw 3 is rounded so that the organ is not damaged even if the distal end portion 31 protrudes from the back surface of the artificial bone 8. In addition, it is preferable that the length of the artificial bone screw 3 is changed in accordance with the thickness of the artificial bone 8 to be used so that the distal end portion 31 does not protrude.

The artificial bone screw 3 and the living bone screw 4 have different tip shapes depending on their use conditions, but they are very small, so it is difficult to identify them by visual recognition of the tip shape. There is a high risk of being misused. Therefore, it is preferable that identification is possible by a method other than visual recognition. For example, a method is conceivable in which the shape and dimensions of the driver grooves formed on the heads 31 and 41 of the screws 3 and 4 are made different so that the screws can be screwed only with dedicated drivers. Actually, since the artificial bone screw 3 and the living bone screw 4 require different torque control at the time of screwing, it is preferable to use dedicated drivers respectively.
The artificial bone screw 3 and the living bone screw 4 have a hardness that can be screwed into the living bone 9 and are made of a material having high biological safety. For example, the artificial bone screw 3 and the living bone screw 4 are made of metal such as titanium or titanium alloy. Is formed.

  The plate 5 that bridges and connects the artificial bone 8 and the living bone 9 can be a microplate used in a known plate system. The microplate is made of a thin plate of titanium or a titanium alloy having high biological safety, and is formed by appropriately arranging a narrow band-shaped bridging portion 51 and a screw hole 52 through which a screw is inserted. There are various types of microplates depending on the arrangement of the bridging portions. For example, an I-type plate in which bridging portions are arranged in a straight line, an L-type plate in which one end of the I-type plate is bent in a right angle direction, a Y-type plate in which one end of the I-type plate is branched, and an I-type plate There are an X-type plate with both ends branched, a □ -type plate with a bridging part joined in a square shape, and a △ -type plate with a bridging part joined in a triangle, and as a modification, around a circular plate with a watermark pattern There is a ○ type with multiple screw holes. Any shape microplate can be suitably used in the present invention.

  The artificial bone fixing structure 1 using the artificial bone fixing jig 11 according to the present invention includes an operation of inserting the buffer member 2 into the opening 81 of the artificial bone 8, an operation of fixing the bridging member 5 to the artificial bone 8, It is formed on the living bone 9 by the bridging member 5 and the operation.

  In the insertion operation of the buffer member 2, the bulging portion 22 and the insertion portion 23 of the buffer member 2 are inserted into the opening 81 of the artificial bone 8 from the artificial bone surface side 85. The outer diameter of the bulging portion 22 of the buffer member 2 is larger than the inner diameter of the opening 81. However, since the cutout portion 25 is formed, the outer diameter of the bulging portion 22 can be reduced, so that the bulging portion 22 can be inserted into the opening 81 relatively easily. The buffer member 2 is inserted until the bulging portion 22 passes through the through hole 81 and protrudes to the back surface side 86 of the artificial bone 8. The bulging portion 22 protruding from the artificial bone back side 86 is released from the stress in the reduced diameter direction and restored to the original outer diameter. Thereby, since the outer diameter of the bulging part 22 becomes larger than the inner diameter of the opening part 81, the bulging part 22 engages with the edge part of the opening part 81. Further, on the artificial bone surface side 85, the flange 21 of the buffer member 2 extends around the opening 81, and the buffer member 2 is further prevented from being inserted into the opening 81. In this way, the buffer member 2 is temporarily fixed inside the opening 81 by the flange 21 and the bulging portion 22. However, since the bulging portion 22 is reduced in diameter by a relatively weak force, there is a risk of the buffer member 2 falling off when used for a long time in this state.

  In the fixing operation of the artificial bone 8 and the bridging member 5, the artificial bone screw 3 is first inserted into one of the screw holes 52 of the plate 5, and then screwed into the through hole 24 of the buffer member 2 from the artificial bone surface side 85. And is screwed to the inner wall 243 of the through hole. When the distal end portion 32 of the artificial bone screw 3 reaches the region where the cut portion 25 is formed, the outer diameter of the bulging portion 22 becomes difficult to reduce, and when the screw 3 is inserted deeper, the expanding portion. 22 cannot be reduced in diameter. Therefore, the buffer member 2 has almost no possibility of falling off from the opening 81 of the artificial bone 8, and a stable binding force can be obtained over a long period of time. The artificial bone screw 3 is fixed to the artificial bone 8 together with the plate 5 by being screwed to the buffer member 2.

  In the operation of fixing the living bone 9 and the bridging member 5, the living bone 9 is inserted into the other screw hole 52 of the plate 5 and screwed into the living bone 9 from its surface side 95. The plate 5 is connected. The position where the living bone screw 4 is screwed to the living bone 9 is determined according to the screw hole 52 of the plate 5 fixed to the artificial bone 8. The screwing of the living bone 9 and the living bone screw 4 is a conventional fixing method. Since the living bone 9 has elasticity, a stable binding force can be obtained over a long period of time. The plate 5 is fixed to the living bone 9 by the living bone screw 4, and the artificial bone 8 and the living bone 9 are connected by the bridging portion 51 of the plate 5.

  The fixation by the artificial bone fixation structure 1 of the present invention extends the fixation of the living bone-living bone by the conventionally known plate system to the fixing of the living bone-artificial bone. The know-how cultivated through the use of the plate system can be passed on as it is.

  FIG. 4 is a perspective view illustrating the state in which the artificial bone is fixed to the skull by the artificial bone fixing structure 1 of the present invention from the surface side of the skull. The artificial bone 8 has a large number of openings 81 for the exudate. The living bone-artificial bone was fixed by the artificial bone fixing jig 11 of the present invention using some of the openings 81 (four in this figure) formed near the outer edge of the artificial bone 8. It is preferable that the number and position of the fixing points are appropriately changed in accordance with the shape, size, and fixing site of the artificial bone 8.

  FIG. 5 is an enlarged view of one of the fixing portions fixed by the artificial bone fixing structure 1 of FIG. In this example, an I-type plate 5 having two screw holes 52 at both ends is used. On the surface side 85 of the artificial bone 8, the flange portion 21 of the buffer member 2 is disposed. In this example, the flange portion 21 was formed in a disk shape having a diameter of about 8 mm. Since the insertion part 23 and the bulging part 22 of the buffer member 2 are located inside the opening 81 of the artificial bone 8 and the back side 86 of the artificial bone 8, they are not shown in the drawing. One end 55 of the plate 5 is arranged on the surface side of the flange portion 21, and the screw hole 52 formed therein is fixed to the artificial bone 8 by the artificial bone screw 3, and the plate 5 and the artificial bone 8 are fixed. And In this example, the artificial bone 8 and the plate 5 are fixed by one artificial bone screw 3, but the opening 81 of the artificial bone 8 is formed at an appropriate position, and the buffer member 2 If the shape of the flange portion is devised, it can be fixed with two screws 3.

  The other end 56 of the plate 5 is disposed on the surface side 95 of the living bone 9, and the screw hole 52 formed therein is fixed to the living bone 9 by the living bone screw 4, and the plate 5 and the living body 9 are fixed. The bone 9 is connected. In this example, the living bone 9 and the plate 5 are fixed by two living bone screws 4 and 4.

  Since the artificial bone fixing structure of the present invention can fix the artificial bone and the living bone using a conventional method of screwing the microplate, a simple operation can provide a reliable fixation over a long period of time, In addition, there is an advantage that there is less risk of inadvertently damaging the internal organs of the skeleton. Furthermore, if an exudate opening conventionally formed in an artificial bone is used, it is not necessary to newly form an opening for fixation in the artificial bone, so for fixing an artificial bone currently used, Can respond immediately.

It is a fragmentary sectional view of the site | part which couple | bonded the living bone and the artificial bone by the artificial bone fixation structure concerning this invention. It is the front view (A) and bottom view (B) of the buffer member contained in the artificial bone fixation structure of this invention. It is the screw for living bones (A) and the screw for artificial bones (B) included in the artificial bone fixing structure of the present invention. It is a perspective view which shows the state which combined the skull and the artificial bone by the artificial bone fixation structure of this invention. FIG. 5 is an enlarged view of a fixing portion by the artificial bone fixing structure shown in FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Artificial bone fixed structure 2 Buffer member 3 Artificial bone screw (screw member)
4 Screw for living bone (screw member)
5 Plate (Bridged member)
DESCRIPTION OF SYMBOLS 8 Artificial bone 9 Living body bone 11 Artificial bone fixing jig 21 Flange part 22 Bulging part 23 Insertion part 24 Through-hole 25 Cutting part 32 Tip part of artificial bone screw 42 Tip part of biological bone screw 51 Plate bridge part 52 Plate screw hole

Claims (8)

It is a structure that fixes an artificial bone to a living bone using a fixing jig,
The fixing jig is
(A) a screw member screwed to an artificial bone and a living bone;
(B) a screw member that is fixed at both ends and includes a bridging member that connects the artificial bone and the living bone;
Prior to screwing the screw member onto the artificial bone, the artificial bone is pre-formed with an opening,
A buffer member having a cylindrical shape as a whole and having a through-hole in the center, an expansion portion divided into at least three ends at the front end portion, and a flange portion at the rear end portion is inserted into the opening portion. An artificial bone fixing structure in which the screw member is screwed into the central through hole of the buffer member and the tip inflated portion is expanded from the opening diameter to prevent the screw member from coming off.   The artificial bone fixing structure according to claim 1, wherein the buffer member is made of ultrahigh molecular weight polyethylene.   The artificial bone fixing structure according to claim 1 or 2, wherein an inner diameter of the through hole of the buffer member is smaller than an outer diameter of the screw member.   The artificial bone fixing structure according to any one of claims 1 to 3, wherein an inner diameter of the through hole of the buffer member is reduced from one end of the insertion portion toward the other end. A fixing jig for fixing an artificial bone to a living bone, the fixing jig,
(A) a screw member screwed to an artificial bone and a living bone;
(B) a bridging member that is fixed at both ends with a screw member and connects the artificial bone and the living bone;
(C) A cushioning member interposed between the artificial bone and a screw member screwed onto the artificial bone, and has a cylindrical shape as a whole, has a through hole in the center, and is expanded at least by 30 at the tip. And a cushioning member provided with a flange portion at the rear end portion,
By inserting the buffer member into the opening of the artificial bone formed in advance, the buffer member can be temporarily fixed to the opening, and then the screw member is screwed into the central through-hole of the buffer member so that the tip inflated portion of the opening is An artificial bone fixing jig that can be fixed to the opening to prevent the buffer member from coming off by expanding the diameter of the opening.   The artificial bone fixing jig according to claim 5, wherein the buffer member is made of ultrahigh molecular weight polyethylene.   The artificial bone fixing jig according to claim 5 or 6, wherein an inner diameter of the through hole is smaller than an outer diameter of the screw member. The artificial bone fixing jig according to any one of claims 5 to 7, wherein an inner diameter of the through hole is reduced from one end of the insertion portion toward the other end.

Images