JP2010099293A - Bone anchor unit for vertebral column fixation and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the complication of a structure by reducing the number of components, and to prevent the structure of a part to be engaged with a vertebra in a bone engaging member from being restricted in relation with the dimension configuration of a housing member. <P>SOLUTION: The bone anchor unit 1 for vertebral column fixation includes the bone engaging member 11 to be engaged with the vertebra 100, a housing member 13 provided with an opening 14 on one end side and an opening 15 on the other end side, and an insert member 12 disposed on the inner side of the housing member 13 and provided with a rod seat part 21. In a state wherein a head part 11b provided on the end part on the other end side in the bone engaging member 11 is inserted from the opening 14 on one opening side, an end part 19 on one side in the housing member 13 is latched on the head part 11b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention includes a bone anchor unit for spinal fixation that fixes a spine by holding a rod member that has at least a rod-like portion and is arranged along the spinal column and is engaged with the spine, and It relates to the manufacturing method.

  Conventionally, using a bone anchor unit for spinal fixation that is arranged in an engaged state with respect to the vertebrae such as the cervical vertebra, the thoracic vertebra, and the lumbar vertebra and has a rod-like portion and holds a rod member arranged along the spinal column Surgery to fix the spine is being performed. As bone fixing units for spinal fixation used in such operations, those disclosed in Patent Documents 1 to 9 are known.

  The bone anchor units for spinal fixation disclosed in Patent Literature 1 to Patent Literature 7 are each provided with a bone engaging member, a housing member, and an insert member. The bone engaging member is configured as a screw type in which one end side is screwed and engaged with the vertebra of the spine. The housing member is provided with openings on one end side, which is a side disposed near the spine, and on the other end side, which is a side disposed away from the spine, and the one end side opening and the other end side opening are provided. It is configured to communicate. The insert member is arranged inside the housing member and is configured to contact the head on the other end of the bone engaging member and to contact the rod-shaped portion described above. The bone engaging member is inserted into the other end side opening of the housing member from one end side thereof, and the one end side of the bone engaging member is disposed so as to protrude from the one end side opening of the housing member. Moreover, the rod-shaped part of an insert member and a rod member is also inserted from the other end side opening of a housing member. In this state, the rod member is held by the bone anchor unit for spinal fixation by attaching a fixing member that engages with the other end of the housing member and presses and fixes the rod-shaped portion against the insert member. The spine is fixed. In the bone anchor unit for spinal fixation disclosed in Patent Documents 1 to 6, the bone engaging member is inserted from the opening on the other end side of the housing member, and the head of the bone engaging member is one end side of the housing member. It is configured to be locked directly and to be prevented from coming off. On the other hand, in the bone anchor unit for spinal fixation disclosed in Patent Document 7, the bone engaging member inserted from the opening on the other end side of the housing member is locked to the housing member via the insert member to prevent the bone engaging member from coming off. It is configured to be.

  In the bone anchor unit for spinal fixation disclosed in Patent Literature 8 or Patent Literature 9, in addition to the bone engaging member, the housing member, and the insert member, the bone engaging member is prevented from coming off from one end side opening of the housing member. A ring-shaped member is further provided. In the spinal fixation bone anchor unit disclosed in Patent Literature 8 or Patent Literature 9, the bone engaging member is inserted into the opening on the one end side of the housing member from the head provided on the other end side. The ring-shaped member is also inserted into the housing member from the one end side opening together with the head of the bone engaging member. The ring-shaped member is formed in a state in which a part thereof in the circumferential direction is cut away, and once the diameter of the ring-shaped member is reduced and inserted into one end side opening of the housing member, the diameter is increased. Thus, the ring-shaped member is attached so as to be partially fitted into the groove inside the housing member. Thereby, the head of the bone engaging member is locked to the ring-shaped member, and the bone engaging member is prevented from coming off from the housing member.

Japanese Patent No. 2510476 Japanese Patent No. 3497512 Special table 2001-501109 gazette Special table 2001-501110 gazette JP-T-2001-506907 US Patent Application Publication No. 2006 / 0293664A1 Japanese Patent No. 3792287 Special table 2003-508109 gazette Special table 2003-502676

  In the bone anchor unit for spinal fixation disclosed in Patent Literature 1 to Patent Literature 7, since it is composed of three parts, a bone engaging member, a housing member, and an insert member, the number of parts can be reduced. There is an advantage that the structure can be easily simplified. However, in these bone anchoring units for spinal fixation, the bone engaging member is inserted into the other end side opening of the housing member from one end side thereof, and the one end side of the bone engaging member protrudes from the one end side opening of the housing member. Be placed. For this reason, the structure on one end side that engages with the vertebra in the bone engaging member needs to be formed to be smaller than the diameter dimension of the head on the other end side and to be able to penetrate the housing member. . On the other hand, the housing member is required to be smaller because of the limitation of the arrangement space in the human body. For this reason, there exists a problem that the structure of the one end side in a bone engaging member receives a restriction | limiting largely by the relationship with the dimension structure of a housing member.

  On the other hand, in the spinal fixation bone anchor unit disclosed in Patent Document 8 or Patent Document 9, the bone engaging member is inserted into the opening on one end side of the housing member from the head provided on the other end side. For this reason, it can prevent that the structure of the one end side in a bone engaging member receives restrictions by the relationship with the dimension structure of a housing member. However, in these bone anchoring units for spinal fixation, in addition to the bone engaging member, the housing member, and the insert member, as described above, a ring-shaped member for preventing the bone engaging member from coming off is further required. For this reason, there is a problem that the number of parts increases and the structure is likely to be complicated. Further, a special structure for attaching the ring-shaped member needs to be formed on the housing member, and the structure of the housing member is likely to be complicated. Further, since a process of inserting a ring-shaped member on one end side of the housing member together with the bone engaging member and attaching the ring-shaped member to the inside of the housing member is required, the number of steps is increased and the manufacturing process is complicated. There is a problem of becoming.

  In view of the above situation, the present invention can reduce the number of parts and suppress the complexity of the structure, and the structure of the portion of the bone engaging member that engages with the vertebra is related to the dimensional configuration of the housing member. An object of the present invention is to provide a spinal fixation bone anchor unit capable of preventing the restriction and to provide a method for manufacturing the spinal fixation bone anchor unit.

  To achieve the above object, a bone anchor unit for spinal fixation according to the first invention has a rod-shaped portion having at least a rod-like portion and is arranged in a state of being engaged with the spine. The present invention relates to a bone anchor unit for spinal fixation that fixes the spine. The spinal fixation bone anchor unit according to the first aspect of the present invention includes a bone engaging member that engages at one end with the vertebra of the spine, one end opening that opens at one end, and one end that opens at the other end. An opening on the other end side communicating with the side opening, and a head provided on the other end of the bone engaging member is inserted into the opening on the one end side with respect to the head. A housing member whose one end is locked, and an inner side of the housing member, at least a part of which is in contact with the head and at least a part of which is in contact with the rod-shaped part. An insert member provided on the other end side of the rod seat, the bone engaging member engages with a vertebra, and the rod-shaped portion of the rod member inserted from the other end side opening is Arranged to contact the rod seat A fixing member that engages with the other end side of the housing member and presses and fixes the rod-shaped portion against the insert member is fixed to hold the rod member and fix the spine. Features.

  According to this invention, the bone anchor unit for spinal fixation is composed of three parts, a bone engaging member, a housing member, and an insert member, and there is no need to provide a ring-shaped member for retaining the bone engaging member. . For this reason, the number of parts can be reduced, and the structure can be simplified. And since there is no ring-shaped member, it is not necessary to provide a special structure in a housing member, and complication of the structure of a housing member can be suppressed. Moreover, since there is no ring-shaped member as described above, it is possible to prevent an increase in man-hours caused by attaching the ring-shaped member. In this spinal fixation bone anchor unit, the bone engaging member is inserted into the opening on the one end side of the housing member from the head portion provided on the other end side, and at the end portion on one end side of the housing member in this head portion. The housing member is locked to prevent the housing member from coming off. For this reason, it can prevent that the structure of the one end side engaged with the vertebra in a bone engaging member receives restrictions with respect to the dimension structure of the housing member in which size reduction is requested | required. Conversely, this eliminates the need to enlarge the housing member in accordance with the structure of the one end side of the bone engaging member, so that it is possible to easily achieve downsizing of the housing member that has a large restriction on the arrangement space in the human body. Can do.

  Therefore, according to the present invention, it is possible to reduce the number of parts and suppress the complexity of the structure, and the structure of the portion of the bone engaging member that engages with the vertebra is restricted by the relationship with the dimensional configuration of the housing member. It is possible to provide a bone anchor unit for spinal fixation that can be prevented.

  The bone anchor unit for spinal fixation according to the second aspect of the present invention is the bone anchor unit for spinal fixation of the first aspect, wherein the end of one end side of the housing member is the inner side after the head is inserted from the opening on the one end side. The end of the one end side is locked to the head by being caulked.

  According to the present invention, after the head portion of the bone engaging member is inserted from the opening on the one end side of the housing member, the end portion on one end side of the housing member is caulked inward to be locked with the head portion of the bone engaging member. The bone engaging member is prevented from coming off. For this reason, the head of the bone engaging member inserted from the one end side opening with respect to the housing member can be easily locked by caulking. Therefore, it is possible to reduce the number of parts and to suppress the complexity of the structure, and to prevent the structure of the portion of the bone engaging member that engages with the vertebra from being restricted due to the dimensional configuration of the housing member. The bone anchor unit for spinal fixation that can be realized can be easily realized by providing a caulking portion on the housing member.

  A bone anchor unit for spinal fixation according to a third aspect of the present invention is the bone anchor unit for spinal fixation according to the second aspect of the present invention, wherein the end on one end side is caulked inward on the inner periphery of the end on one end side of the housing member. A head-facing concave portion formed so as to be recessed at a position facing the periphery of the head when the head is pressed.

  According to the present invention, a head-facing concave portion that is recessed at a position facing the periphery of the head of the bone engaging member when crimped is formed on the inner periphery of the end portion on one end side of the housing member. For this reason, it can be easily caulked with a smaller load at a position facing the head of the bone engaging member, and the above-mentioned head-facing concave portion and the periphery of the head of the bone engaging member can be more easily brought into contact with each other. Can be made. Thereby, at the time of caulking, the edge part of the one end side of a housing member can be efficiently crimped | bonded to the head of a bone engaging member.

  The bone anchor unit for spinal fixation according to a fourth aspect of the present invention is the bone anchor unit for spinal fixation according to the third aspect of the present invention, wherein the concave portion facing the head is crimped inward on one end of the housing member. It is provided as a curved surface portion that abuts along the periphery of the head.

  According to the present invention, the head-facing concave portion is provided as a curved surface portion that comes into contact with the periphery of the head of the bone engaging member when crimped. For this reason, during caulking, a wider contact area can be secured easily between the curved surface portion and the periphery of the head of the bone engaging member with a smaller load. Thereby, at the time of caulking, the end of the one end side of the housing member can be more efficiently crimped to the head of the bone engaging member.

  The bone anchor unit for spinal fixation according to a fifth aspect of the present invention is the bone anchor unit for spinal fixation according to any one of the first to fourth aspects of the invention, wherein the rod seat portion is a part of the outer periphery of the rod-shaped portion that abuts. The insert member is formed in a groove shape having a concave surface curved along the outer periphery, and a convex portion is provided on the outer periphery of the insert member so as to protrude outward. A recessed portion that is recessed at the periphery and engages with the protruding portion, and an open portion that communicates with the recessed portion and is opened at at least one of the outer periphery and one end of the housing member. And a recess having the following features.

  According to the present invention, since the rod seat portion is formed in a groove shape having a concave surface curved along the outer periphery of the rod-shaped portion, the rod member can be stably supported with respect to the insert member. For this reason, in the spinal fixation bone anchor unit, the rod member can be held more stably and firmly. In the insert member of the bone anchor unit for spinal fixation disclosed in Patent Documents 5 to 7, the rod seat portion is formed in a groove shape having a recessed surface along the outer periphery of the rod-shaped portion.

  However, in the bone anchor unit for spinal fixation disclosed in Patent Document 5, a mechanism for positioning the insert member inside the housing member is not particularly provided, and the concave surface of the rod seat portion is suitable for the rod-shaped portion. It is difficult to fit in. Further, in the bone anchor unit for spinal fixation disclosed in Patent Document 6, a spring protrusion having a fine and complicated shape is formed on the outer periphery of the insert member, and the spring protrusion is locked to a through hole formed in the housing member. Thus, the insert member is configured to be positioned inside the housing member. However, in this bone anchor unit for spinal fixation, although the insert member can be positioned, it is necessary to process a fine and complicated shape on the outer periphery of the insert member. And it is necessary to arrange | position an insert member inside a housing member, adjusting the position of the above-mentioned fine spring projection part and a through-hole, and the problem that arrangement | positioning in an inside of a housing member requires an effort There is also. Further, in the bone anchor unit for spinal fixation disclosed in Patent Document 7, a hole-like thinned portion is formed in a part of the wall portion of the housing member, and a recess is formed at a corresponding position on the outer periphery of the insert member. The hole is provided, and the thinned portion is configured to be positioned by crimping from the outside to the hole on the outer periphery of the insert member. However, in this bone anchor unit for spinal fixation, although the insert member can be positioned, it is necessary to process a special shape for crimping into the housing member. There is a risk of deformation to the part. And it is necessary to arrange the insert member inside the housing member while adjusting the position of the thinned portion and the outer peripheral hole of the insert member, and it takes time to arrange the insert member in the housing member. There is also a problem.

  On the other hand, according to the bone anchor unit for spinal fixation of the fifth invention, the convex portion is formed on the outer periphery of the insert member, and the concave portion having the concave portion is formed on the inner periphery of the housing member. And the open part which is open | released on the outer side of a housing member and is connected to a recessed part is formed in the recessed part. For this reason, when inserting and arrange | positioning an insert member inside a housing member, a convex part can be easily engaged with a recessed part, confirming from the outer side of a housing member via an open part. Thereby, the operation | work which positions an insert member inside a housing member can be performed easily, and there is no possibility that a housing member may deform | transform. And since it is only necessary to form a convex part on the outer periphery of the insert member and form a concave part on the inner periphery of the housing member, a mechanism for positioning the insert member in the housing member can be formed with a simple structure. it can. Therefore, according to the present invention, in the bone anchor unit for spinal fixation that can achieve the effects of the first invention, the rod member can be more stably and firmly held, and the insert member in the housing member can be held firmly. The positioning mechanism can be formed with a simple structure, and the positioning of the insert member can be easily performed.

  A bone anchor unit for spinal fixation according to a sixth aspect of the invention is the bone anchor unit for spinal fixation according to the fifth aspect of the invention, wherein the insert member extends toward one end side or the other end side on the outer peripheral side and bends inward. And a flexible portion formed with the convex portion on the tip side is provided, and the concave portion is formed so that the open portion is opened on the outer periphery of the housing member, After the housing member is provided as a through hole that communicates the inner and outer peripheral sides of the housing member, the insert member is inserted into the housing member from the opening on the one end side, and the flexible portion is bent inward. The convex portion engages with the concave portion after elastic recovery.

  According to the present invention, in the insert member, by providing a flexible portion that extends in a cantilevered manner with respect to the main body portion and has a convex portion formed on the distal end side, the convex portion is formed into a concave portion by utilizing elastic recovery force. The configuration to be engaged can be realized with a simple structure. And also in a housing member, the recessed part of a simple structure is realizable as a through-hole which connects an inner peripheral side and an outer peripheral side. Thereby, the mechanism for positioning the insert member within the housing member can be formed with a very simple structure. And after inserting an insert member from one end side opening of a housing member and bending a flexible part inside, while confirming from the outside of a housing member through the recessed part of a through-hole, a flexible part is elastically recovered. The convex portion can be easily engaged with the concave portion. Thereby, the operation | work which positions an insert member inside a housing member can be performed very easily. Further, it is possible to realize a positioning mechanism in which the housing member is not deformed.

  The bone anchor unit for spinal fixation according to a seventh aspect of the present invention is the bone anchor unit for spinal fixation according to the fifth aspect of the invention, wherein the recess is formed such that the open portion is opened at an end on one end side of the housing member. The recessed portion is formed in a groove shape extending from one end side toward the other end side on the inner periphery of the housing member, and the insert member moves while the convex portion slides against the concave portion and moves. The housing member is inserted from the one end side opening.

  According to the present invention, it is only necessary to form a convex portion on the outer periphery of the insert member and form a groove-shaped concave portion on the inner periphery of the housing member. Therefore, the mechanism for positioning the insert member in the housing member is very It can be formed with a simple structure. Then, the insert member is inserted into the housing member from one end side opening while the convex portion slides and moves with respect to the groove-shaped concave portion opened to the outside in the housing member. For this reason, the operation of positioning the insert member on the inner side of the housing member can be performed very easily only by sliding the convex portion and the groove-shaped concave portion while sliding from the outer side of the housing member. Further, it is possible to realize a positioning mechanism in which the housing member is not deformed.

  The bone anchor unit for spinal fixation according to an eighth aspect of the present invention is the bone anchor unit for spinal fixation according to any one of the first to seventh aspects of the present invention, wherein the bone engaging member is engaged with the vertebra at one end side. A screw portion is formed to be joined.

  According to the present invention, even in a bone anchor unit for spinal fixation that includes a bone engaging member that is screwed into and engaged with a vertebra by a screw portion on one end side, the number of parts can be reduced and the complexity of the structure can be suppressed. In addition, the structure of the portion of the bone engaging member that engages with the vertebra can be prevented from being restricted due to the dimensional configuration of the housing member.

  The bone anchor unit for spinal fixation according to a ninth aspect of the present invention is the bone anchor unit for spinal fixation according to the eighth aspect of the invention, wherein the diameter of the outermost peripheral portion of the screw part is perpendicular to the axial direction of the screw part. It is characterized by being larger than the maximum diameter dimension of the part.

  According to this invention, the bone engaging member is formed such that the diameter dimension of the outermost peripheral part of the screw part is larger than the maximum diameter dimension of the head part. For this reason, since the screw part which is inserted from the opening on one end side with respect to the housing member and is not restricted by the relationship with the dimensional configuration of the housing member can be formed large, the strength of the screw part can be improved and the damage can be suppressed. The bond strength to the vertebra can also be improved.

  The bone anchor unit for spinal fixation according to the tenth aspect of the present invention is the bone anchor unit for spinal fixation according to the eighth aspect or the ninth aspect, wherein the diameter of the outermost peripheral portion of the screw portion is one end of the housing member. Is larger than the minimum diameter dimension of the opening on the one end side locked to the head.

  According to this invention, the bone engaging member is formed such that the diameter dimension of the outermost peripheral portion of the screw portion is larger than the minimum diameter dimension of the opening on the one end side of the housing member. For this reason, since the screw part which is inserted from the opening on one end side with respect to the housing member and is not restricted by the relationship with the dimensional configuration of the housing member can be formed large, the strength of the screw part can be improved and the damage can be suppressed. The bond strength to the vertebra can also be improved. In addition, regardless of the size of the screw portion, the dimension of the housing member in the radial direction can be reduced, and the housing member can be reduced in size.

  In addition, a method for manufacturing a bone anchor unit for spinal fixation according to an eleventh aspect of the present invention for achieving the above-described object includes a rod member having at least a rod-shaped portion and disposed along the spinal column, and a spine. The present invention relates to a method for manufacturing a bone anchor unit for spinal fixation that manufactures a bone anchor unit for spinal fixation that fixes the spine by being placed in an engaged state. The bone anchor unit for spinal fixation according to the eleventh aspect of the present invention includes a bone engaging member forming step for forming a bone engaging member that engages one end side with the vertebra of the spine, and at least one of the rod-shaped portions. Forming an insert member provided with a rod seat portion against which the portion abuts, an insert member forming step, one end side opening opened at one end side, and opening at the other end side communicating with the one end side opening and the rod An opening at the other end into which the rod-shaped portion of the member is inserted, and a fixing member that presses and fixes the rod-shaped portion against the rod seat portion of the insert member is engaged with the other end side. A housing member forming step for forming a housing member to be attached, an insert member arranging step for arranging the insert member inside the housing member, and the bone A head provided at the other end of the joint member is inserted into the housing member from the opening on the one end side so as to be able to contact at least part of one end side of the insert member, and one end of the housing member And a caulking step of locking the end on the one end side with respect to the head by caulking the end on the side inward.

  According to this invention, a bone anchor unit for spinal fixation, which is composed of three parts of a bone engaging member, a housing member, and an insert member and does not require the provision of a ring-shaped member for retaining the bone engaging member, is manufactured. can do. For this reason, the number of parts can be reduced, and a bone anchor unit for spinal fixation with a simplified structure can be manufactured. And since there is no ring-shaped member, it is not necessary to provide a special structure in a housing member, and complication of the structure of a housing member can be suppressed. Moreover, since there is no ring-shaped member as described above, it is possible to prevent an increase in man-hours caused by attaching the ring-shaped member. In this method of manufacturing a bone anchor unit for spinal fixation, after the head of the bone engaging member is inserted from the opening on the one end side of the housing member, the end portion on the one end side of the housing member is caulked inward to engage the bone anchor. The bone engaging member is locked with the head of the combined member, and the bone engaging member is prevented from coming off. For this reason, it can prevent that the structure of the one end side engaged with the vertebra in a bone engaging member receives restrictions with respect to the dimension structure of the housing member in which size reduction is requested | required. Conversely, this eliminates the need to enlarge the housing member in accordance with the structure of the one end side of the bone engaging member, so that it is possible to easily achieve downsizing of the housing member that has a large restriction on the arrangement space in the human body. Can do. Moreover, the head of the bone engaging member inserted from the one end side opening with respect to the housing member can be easily locked by caulking.

  Therefore, according to the present invention, it is possible to reduce the number of parts and suppress the complexity of the structure, and the structure of the portion of the bone engaging member that engages with the vertebra is restricted by the dimensional configuration of the housing member. It is possible to manufacture a bone anchor unit for spinal fixation that can prevent this.

  A spinal fixation bone anchor unit manufacturing method according to a twelfth aspect of the present invention is the spinal fixation bone anchor unit manufacturing method of the eleventh aspect of the present invention, wherein in the insert member forming step, the outer periphery of the insert member faces outward. In the housing member forming step, a protruding convex portion is formed, and the rod seat portion is formed in a groove shape having a concave surface curved along a part of the outer periphery of the rod-shaped portion that abuts. A recessed portion is formed so as to be recessed in the inner periphery of the housing member, and an open portion is formed which communicates with the recessed portion and is opened to at least one of the outer periphery and one end of the housing member. In the insert member arranging step, the insert member is formed in the housing with the convex portion engaged with the concave portion. Characterized in that it is arranged inside the wood.

  According to the present invention, the rod seat portion is formed in a groove shape having a concave surface curved along the outer periphery of the rod-shaped portion. For this reason, in the spinal fixation bone anchor unit manufactured by this manufacturing method, the rod member can be stably supported with respect to the insert member, and the rod member can be more stably and firmly held. . According to the method for manufacturing a bone anchor unit for spinal fixation, a convex portion is formed on the outer periphery of the insert member, a concave portion having a concave portion is formed on the inner periphery of the housing member, and the outer portion of the housing member is further formed in the concave portion. An open portion that is opened to communicate with the recessed portion is formed. For this reason, when the insert member is inserted and arranged inside the housing member in the insert member arranging step, the convex portion is easily engaged with the concave portion while checking from the outside of the housing member through the open portion. be able to. Thereby, the operation | work which positions an insert member inside a housing member can be performed easily, and there is no possibility that a housing member may deform | transform. And since it is only necessary to form a convex part on the outer periphery of the insert member and form a concave part on the inner periphery of the housing member, a mechanism for positioning the insert member in the housing member can be formed with a simple structure. it can. Therefore, according to the present invention, the spinal fixation bone anchor unit capable of holding the rod member more stably and firmly is manufactured in the spinal fixation bone anchor unit manufacturing method capable of producing the effect of the tenth invention. can do. In the present invention, a mechanism for positioning the insert member in the housing member can be formed with a simple structure, and the insert member can be positioned easily.

  According to the present invention, it is possible to reduce the number of parts and suppress the complexity of the structure, and the structure of the portion of the bone engaging member that engages with the vertebra is restricted by the dimensional configuration of the housing member. It is possible to provide a bone anchor unit for spinal fixation that can prevent the above, and a method for manufacturing the bone anchor unit for spinal fixation.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is a spinal fixation bone anchor unit for fixing a spine by holding a rod member arranged along the spine having at least a rod-like portion and engaging with the spine. And a method of manufacturing the spinal fixation bone anchor unit can be widely applied.

(First embodiment)
FIG. 1 is a diagram illustrating a state in which the spinal fixation bone anchor unit 1 according to the first embodiment of the present invention is used to fix the spine 100 constituting the spinal column 100. In FIG. 1, only members such as the spine 100 which is a thoracic vertebra and a bone anchor unit 1 for spinal fixation (hereinafter simply referred to as “bone anchor unit 1”) are illustrated. As shown in FIG. 1, in the operation of fixing the spine 100, a plurality of bone anchor units 1 are arranged in a state of being engaged with the vertebra 100a of the spine 100, respectively. Then, a rod member 101 formed in a round bar shape having a rod-shaped portion 101 a is disposed along the spinal column 100 and held by each bone anchor unit 1. For example, the rod members 101 are arranged on both sides of the spinal column 100, and the rod members 101 are connected by a connector 102. A plurality of wires 103 are wound around one of the rod members 101 and the spine 100, and by tightening the wires 103, a correction force in the direction along the rod member 101 is applied to the spine 100. In the present embodiment, the rod member 101 is configured to have the rod-shaped portion 101a over the entire length in the longitudinal direction, but this need not be the case. The rod member is not limited to a form having a rod-like portion over the entire length, and may have a rod-like portion partially. For example, a rod-like member having a plate-like plate portion on both ends is provided with a rod-like portion. A portion may be provided.

  Next, the spinal fixation bone anchor unit 1 according to this embodiment will be described. FIG. 2 is a front view (FIG. 2A) and a side view (FIG. 2B) showing the bone anchor unit 1. 3 is a cross-sectional view taken along line AA in FIG. 2A (FIG. 3A) and a cross-sectional view taken along line BB in FIG. 2B (FIG. 3B). is there. 4 is a cross-sectional view of the bone anchor unit 1 showing a state in which the rod member 101 is held, and is a cross-sectional view (FIG. 4A) showing a cross-section corresponding to FIG. It is sectional drawing (FIG.4 (b)) which shows the cross section corresponding to b). FIG. 5 is an exploded perspective view of the bone anchor unit 1. 3B shows the rod member 101 together, and FIGS. 4 and 5 show the rod member 101 and the fixing nut (fixing member) 104 together. As shown in FIGS. 2 to 5, the bone anchor unit 1 is configured to include three parts: a bone screw 11, an insert member 12, and a housing member 13. In the operation of fixing the spine 100, the rod member 101 and the fixing nut 104 are used. In the following description, in each member, the side disposed near or in the spine 100 is defined as one end side, and the side disposed away from the spine 100 is defined as the other end side.

  FIG. 6 is a front view (FIG. 6A) and a cross-sectional view (FIG. 6B) of the bone screw 11. The bone screw 11 has a screw portion 11a formed on one end side and a head portion 11b formed on an end portion on the other end side. The screw part 11a is provided as a male screw part that is screwed into and engaged with the vertebra 100a. The head portion 11b is formed so that a flat surface is formed at the top of the head and the outer periphery forms a part of a spherical surface, and is provided integrally with the other end side of the screw portion 11a. As a result, the bone screw 11 constitutes a bone engaging member whose one end engages with the vertebra 100a of the spine 100.

  FIG. 7 is a perspective view of the housing member 13 and is a perspective view showing the housing member 13 with its orientation changed in FIGS. 7 (a) and 7 (b). 8 is a plan view (FIG. 8A), a front view (FIG. 8B), a side view (FIG. 8C), and a bottom view (FIG. 8D) of the housing member 13. . 9 is a cross-sectional view taken along the line CC in FIG. 8B (FIG. 9A), and a cross-sectional view taken along the line D-D in FIG. 8C. 7 to 9 show the housing member 13 in a state before being assembled as the bone anchor unit 1.

  As shown in FIGS. 7 to 9, the housing member 13 is formed in a cylindrical shape having a structure in which the other end side is divided into two branches, and one end side opening 14 opened at one end side and the other end opened at the other end side. A side opening 15 is provided. The one end side opening 14 and the other end side opening 15 communicate with each other inside the hollow of the housing member 13. The one end side opening 14 is formed as a hole opening in a circular shape at an end portion on one end side of the housing member 13. On the other hand, the other end side opening 15 is formed so as to open from the end portion on the other end side of the housing member 13 to each of the side portions facing each other. By forming such an opening 15 on the other end side, a bifurcated portion 20 having a bifurcated shape is provided on the other end side of the housing member 13. In addition, between the forked part 20 in the other end side opening 15, it is comprised as an area | region arrange | positioned so that the rod-shaped part 101a of the rod member 101 may penetrate, and the part which the forked part 20 continues is a rod-shaped part. It is formed in a semicircular shape corresponding to the outer periphery of 101a.

  The housing member 13 is formed with a through-hole 18 in each of the bifurcated portions 20 for holding the bone anchor unit 1 with the housing member 13 by a predetermined instrument during the operation of fixing the spine 100. Yes. Further, an internal thread portion 16 that is screwed into a fixing nut 104 (see FIGS. 4 and 5) for fixing the rod-shaped portion 101 a is formed on the inner periphery of the bifurcated portion 20 of the housing member 13. As shown in FIG. 9, the female screw portion 16 has a cross-sectional shape of a screw groove (a cross-sectional shape in a plane including the spiral center of the female screw portion 16) inclined outward from one end side to the other end side. It is formed to tilt. The fixing nut 104 shown in FIGS. 4 and 5 is formed as a male screw member formed with a screw thread to be screwed into the female screw portion 16, and is inserted from the other end side opening 15 to be attached to the housing member 13. It is configured to be engaged with the female screw portion 16 on the other end side. As described above, the thread groove of the female thread portion 16 and the thread of the fixing nut 104 are formed so as to incline outward from one end side toward the other end side. The fixing nut 104 to be fixed is more firmly fixed to the housing member 13.

  Further, as shown in FIGS. 7 and 9, the housing member 13 is provided with a recess 17 having a recessed portion 17a and an open portion 17b. The recessed portion 17 a is formed in a groove shape extending from one end side toward the other end side on the inner periphery of the housing member 13. In addition, this recessed part 17a is comprised so that the convex part 22 of the insert member 12 mentioned later may engage. The open portion 17b communicates with the recessed portion 17a and is formed so as to open toward the outside at the end portion 19 on one end side of the housing member 13.

  As shown in FIGS. 3 and 4, the housing member 13 has an end 19 on one end side of the head 11b with the head 11b of the bone screw 11 inserted through the one end opening 14. It is configured to stop. And in this housing 13, after the head part 11b is inserted from the one end side opening 14, the end part 19 on one end side is locked to the head part 11b by crimping the end part 19 on one end side inward. Is configured to do. As shown in FIGS. 3, 4, and 9, the inner periphery of the end portion 19 on the one end side of the housing member 13 is arranged around the head 11 b when the end portion 19 on the one end side is caulked inward. A curved surface portion 19a is formed so as to be in contact with each other. In the present embodiment, the curved surface portion 19a is a head-facing concave portion formed so as to be recessed at a position facing the periphery of the head portion 11b when the end portion 19 on one end side is caulked inward. Is provided. 3, the diameter dimension Ra of the outermost peripheral portion of the screw portion 11a of the bone screw 11 is such that the end portion 19 on one end side of the housing member 13 is locked to the head portion 11b. It is formed to be larger than the minimum diameter dimension Rb.

  10 is a plan view of the insert member 12 (FIG. 10A), a front view (FIG. 10B), and a cross-sectional view taken along line E-E in FIG. 10A (FIG. 10C). It is. As shown in FIG. 3 to FIG. 5 and FIG. 10, the insert member 12 is disposed inside the housing member 13, one end abuts against the head 11 b of the bone screw 11, and the rod-shaped portion of the rod member 101. A rod seat 21 that abuts on 101a is provided on the other end side. The rod seat portion 21 is formed in a groove shape having a concave surface 21a (see FIG. 10) that is curved along a part of the outer periphery of the rod-shaped portion 101a that abuts. On the other hand, a head contact surface 23 that forms a part of a substantially spherical surface along the outer shape of the head 11b is formed in a portion that contacts the head 11b on one end side of the insert member 12. Further, the outer periphery of the insert member 12 is provided with a convex portion 22 formed so as to protrude outward. When the insert member 12 is arranged inside the housing member 13, the convex portion 22 is inserted into the housing member 13 from the one end side opening 14 while being in sliding contact with the concave portion 17 of the housing member 13. Will be. As a result, the insert member 12 is positioned at a predetermined position inside the housing member 13. When the rod member 101 is inserted between the bifurcated portion 20 in the other end side opening 15 of the housing member 13, the rod-shaped portion 101 a of the insert member 12 with respect to the recessed surface 21 a of the rod seat portion 21. The outer periphery is supported so as to fit properly.

  In the operation for fixing the spine 100, the bone anchor unit 1 assembled in the state shown in FIG. 2 and FIG. 3A is used. The operator first screws the bone screw 11 into the vertebra 100a of the spine 100. To engage. Then, the rod-shaped portion 101 a of the rod member 101 is inserted from the opening 15 on the other end side of the housing member 13, and the rod-shaped portion 101 a is disposed so as to contact the recessed surface 21 a of the rod seat portion 21 of the insert member 12. To do. In this state, as shown well in FIG. 4, the fixing nut 104, which is a fixing member of the present embodiment, is attached by being screwed and engaged with the female screw portion 16 on the other end side of the housing member 13. With this fixing nut 104, the rod-shaped portion 101a is pressed against the rod seat portion 21 of the insert member 12 and fixed. As a result, the rod member 101 is held by the bone anchor unit 1 and the spine 100 is fixed.

  Next, the manufacturing method of the bone anchor unit 1, that is, the manufacturing method of the bone anchor unit for spinal fixation according to the embodiment of the present invention will be described. FIG. 11 is a process diagram showing a method for manufacturing a bone anchor unit for spinal fixation according to this embodiment (hereinafter referred to as “method for manufacturing bone anchor unit 1”). As shown in FIG. 11, the method for manufacturing the bone anchor unit 1 includes a bone engaging member forming step S101, an insert member forming step S102, a housing member forming step S103, an insert member arranging step S104, and a caulking step S105. ing. In addition, in FIG. 11, although the bone engaging member formation process S101, the insert member formation process S102, and the housing member formation process S103 are illustrated in order, these each process (S101, S012, S103) is illustrated. The order may be arbitrarily changed, may be performed in parallel at the same time, and may be performed in any order and timing.

  In the bone engaging member forming step S101, one end side of the rod-shaped member is threaded to form the screw portion 11a and the head portion 11b is processed to the other end side. A bone screw 11 is formed. In the insert member forming step S102, for example, a head contact surface 23 is formed on one end side of a hollow cylindrical member in which a convex portion 22 protruding outward is formed on the outer periphery, and a groove is formed on the other end side. The insert member 12 is formed by forming the concave surface 21 a of the rod-shaped rod seat 21. In the housing member forming step S103, a groove-shaped recess 17 having a recessed portion 17a that is recessed on the inner periphery on one end side and an open portion 17b that is open to the end portion 19 on one end side is formed on the hollow cylindrical member. It is formed. Further, the other end side opening 15 forming the bifurcated portion 20 is processed on the other end side of the member, and the through holes 18 are further processed in the bifurcated portion 20 respectively. Then, the inner thread on the other end side of the member in which the one end side opening 14 and the other end side opening 15 are thus formed is subjected to threading of the female screw portion 16 into which the fixing nut 104 is screwed, and the housing Member 12 is formed.

  In the insert member arrangement step S <b> 104, the insert member 12 is inserted from the one end side opening 14 of the housing member 13 while the convex portion 22 of the insert member 12 moves in sliding contact with the concave portion 17 of the housing member 13. The insert member 12 is disposed inside the housing member 13 with the convex portion 22 engaged with the concave portion 17.

  In the caulking step S105, the head portion 11b of the bone screw 11 is inserted from the one end side opening 14 of the housing member 13 in which the insert member 12 is disposed inside. At this time, the head portion 11 b is disposed so as to fit into and abut on the head contact surface 23 of the insert member 12. In this state, the end 19 on one end of the housing member 13 is caulked inward, so that the end 19 on one end is locked to the head 11 b of the bone screw 11. In addition, as a method of caulking the end portion 19 on one end side of the housing member 13, for example, a roller is disposed in contact with the outer periphery of the end portion 19 on one end side, and the end on one end side is rotated while rotating the roller. A roller molding method can be performed in which the roller 19 is moved while being pressed along the circumferential direction with respect to the outer periphery of the portion 19. Further, an assembly in which the insert member 12 and the head 11b of the bone screw 11 are arranged inside the housing member 13 is attached to a predetermined rotation support mechanism, and a predetermined end is attached to the end 19 on one end side while rotating the assembly. You may perform the method of pressing and crimping a tool. Further, a mold that abuts on the above-described assembly at the end 19 on one end of the housing member 13 is used, and the end 19 on one end can be deformed inward by pressing the assembly against this mold. A method of tightening may be performed. By completing this caulking step S105, the manufacture of the bone anchor unit 1 is completed, and the rod member 101 and the fixing nut 104 are used in an operation for fixing the spine 100.

  According to the bone anchor unit 1 described above, the bone anchor unit 1 is composed of three parts, the bone screw 11, the housing member 12, and the insert member 13, and is provided with a ring-shaped member for retaining the bone screw 11. There is no need. For this reason, the number of parts can be reduced, and the structure can be simplified. And since there is no ring-shaped member, it is not necessary to provide a special structure in the housing member 13, and complication of the structure of the housing member 13 can be suppressed. Moreover, since there is no ring-shaped member as described above, it is possible to prevent an increase in man-hours caused by attaching the ring-shaped member. In the bone anchor unit 1, the bone screw 11 is inserted into the opening 14 on the one end side of the housing member 13 from the head portion 11b provided on the other end side, and the end on the one end side of the housing member 13 in the head portion 11b. It is latched by the part 19 and is prevented from coming off from the housing member 13. For this reason, it can prevent that the structure of the one end side engaged with the vertebra 100a in the bone screw 11 receives restrictions with respect to the dimension structure of the housing member 13 in which size reduction is requested | required. Conversely, this eliminates the need to increase the size of the housing member 13 in accordance with the structure on one end side of the bone screw 11, thereby easily achieving downsizing of the housing member 13, which places great restrictions on the arrangement space in the human body. be able to.

  Therefore, according to the bone anchor unit 1, it is possible to reduce the number of parts and suppress the complexity of the structure, and the structure of the portion of the bone screw 11 that engages with the vertebra 100 a is restricted by the relationship with the dimensional configuration of the housing member 13. Can be prevented.

  Further, according to the bone anchor unit 1, after the head portion 11 b of the bone screw 11 is inserted from the one end side opening 14 of the housing member 13, the end portion 19 on the one end side of the housing member 13 is caulked inward, and the bone screw 11. The bone screw 11 is prevented from coming off. For this reason, the head 11b of the bone screw 11 inserted from the one end side opening 14 with respect to the housing member 13 can be easily locked by caulking.

  Further, according to the bone anchor unit 1, the housing member 13 is recessed on the inner periphery of the end portion 19 on the one end side at a position facing the periphery of the head 11b of the bone screw 11 when the housing member 13 is caulked. A curved surface portion 19a that abuts along the periphery is formed as a head-facing concave portion. For this reason, it can be easily caulked with a smaller load at a position facing the head 11b of the bone screw 11, and the curved portion 19a and the periphery of the head 11b can be more easily brought into contact with each other. Further, since the head-facing concave portion is provided as the curved surface portion 19a, it is easily wider between the curved surface portion 19a and the periphery of the head 11b of the bone screw 11 during caulking with a smaller load. A contact area can be ensured. Thereby, the end 19 on one end side of the housing member 13 can be efficiently crimped to the head 11 b of the bone screw 11 during caulking.

  Further, according to the bone anchor unit 1, the rod seat portion 21 is formed in a groove shape having the concave surface 21a curved along the outer periphery of the rod-shaped portion 101a, so that the rod member 101 is more stably and firmly secured. Can be held. And according to this bone anchor unit 1, when inserting and arrange | positioning the insert member 12 inside the housing member 13, confirming from the outer side of the housing member 13 via the open part 17b, the convex part 22 is made into the recessed part 17. Can be easily engaged. Thereby, the operation | work which positions the insert member 12 inside the housing member 13 can be performed easily, and there is no possibility that the housing member 13 may deform | transform. In the present embodiment, the concave portion 17 is formed in a groove shape opened to the outside, and the convex portion 22 and the concave portion 17 are simply slidably contacted while confirming from the outside of the housing member 13. The operation of positioning the insert member 12 on the inside can be performed very easily. And since the convex part 22 is formed in the outer periphery of the insert member 13, and the recessed part 17 which has the groove-shaped recessed part 17a in the inner periphery of the housing member 13 only needs to be formed, the insert member 12 in the housing member 13 is formed. The positioning mechanism can be formed with a very simple structure.

  Further, according to the bone anchor unit 1, the bone screw 11 is formed such that the diameter dimension Ra of the outermost peripheral portion of the screw portion 11 a is larger than the minimum diameter dimension Rb of the one end side opening 14 of the housing member 13. For this reason, since the screw part 11a which is inserted from the one end side opening 14 with respect to the housing member 13 and is not restricted by the relationship with the dimensional configuration of the housing member 13 can be formed large, the strength of the screw part 11a is improved and breakage occurs. Can be suppressed, and the bonding strength to the vertebra 100a can be improved. Moreover, the dimension of the radial direction of the housing member 13 can be made small irrespective of the magnitude | size of the screw part 11a, and size reduction of the housing member 13 can be achieved.

  Moreover, according to the manufacturing method of the bone anchor unit 1 demonstrated above, it is necessary to provide a ring-shaped member for preventing the bone screw 11 from being composed of three parts, the bone screw 11, the housing member 13, and the insert member 12. It is possible to manufacture a bone anchor unit 1 having no gap. For this reason, the number of parts can be reduced, and the bone anchor unit 1 with a simplified structure can be manufactured. Further, since there is no ring-shaped member, it is possible to prevent an increase in man-hours caused by attaching the ring-shaped member. And in the manufacturing method of the bone anchor unit 1, after the head part 11b of the bone screw 11 is inserted from the one end side opening 14 of the housing member 13, the edge part 19 of the one end side of the housing member 13 is caulked inside, and a bone is carried out. Locking with the head 11b of the screw 11 prevents the bone screw 11 from coming off. For this reason, it can prevent that the structure of the one end side engaged with the vertebra 100a in the bone screw 11 receives restrictions with respect to the dimension structure of the housing member 13 in which size reduction is requested | required, and conversely, There is no need to increase the size of the housing member 13 in accordance with the structure of one end of the screw 11, and the housing member 13 can be easily downsized. Moreover, according to the manufacturing method of the bone anchor unit 1, the head 11b of the bone screw 11 inserted from the one end side opening 14 with respect to the housing member 13 can be easily locked by caulking.

  Therefore, according to the manufacturing method of the bone anchor unit 1, it is possible to reduce the number of parts and suppress the complexity of the structure, and the structure of the portion of the bone screw 11 that engages with the vertebra 100 a is related to the dimensional configuration of the housing member 13. Thus, it is possible to manufacture the bone anchor unit 1 that can prevent the restriction.

  Moreover, according to the manufacturing method of the bone anchor unit 1, since the groove-shaped rod seat part 21 which has the concave surface 21a curved along the outer periphery of the rod-shaped part 101a in the insert member 12, the rod member 101 is formed. The bone anchor unit 1 that can be held more stably and firmly can be manufactured. And according to the manufacturing method of the bone anchor unit 1, when inserting and arrange | positioning the insert member 12 inside the housing member 13 in insert member arrangement | positioning process S104, it confirms from the outside of the housing member 13 via the open part 17b. However, the convex portion 22 can be easily engaged with the concave portion 17. Thereby, the operation | work which positions the insert member 12 inside the housing member 13 can be performed easily, and there is no possibility that the housing member 13 may deform | transform. And since the convex part 22 should just be formed in the outer periphery of the insert member 12, and the recessed part 17 should be formed in the inner periphery of the housing member 13, the mechanism for positioning of the insert member 12 in the housing member 13 is simple. Can be formed with a structure.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 12 is a cross-sectional view showing a spinal fixation bone anchor unit 2 (hereinafter simply referred to as “bone anchor unit 2”) according to a second embodiment of the present invention. The bone anchor unit 2 is used in the same manner as the bone anchor unit 1 of the first embodiment, and is manufactured by a manufacturing method similar to the manufacturing method of the bone anchor unit 1. The bone anchor unit 2 is configured in the same manner as the bone anchor unit 1 of the first embodiment, and includes a bone screw 11, an insert member 12, and a housing member 13. However, the bone anchor unit 2 is different from the first embodiment in the dimensional configuration of the screw portion 11a and the head portion 11b of the bone screw 11. In the following, the same components as those in the first embodiment are denoted by the same reference numerals in the drawings, the description thereof is omitted, and components different from those in the first embodiment will be described.

  As shown in FIG. 12, in the bone screw 11 of the bone anchor unit 2, the diameter dimension Ra of the outermost peripheral part of the screw part 11a is the maximum diameter dimension Rc of the head part 11b in the direction perpendicular to the axial direction of the screw part 11a. It is formed so as to be larger. For this reason, according to the bone anchor unit 2, since the screw part 11a which is inserted from the one end side opening 14 with respect to the housing member 13 and is not restricted by the dimensional configuration of the housing member 13 can be formed large, the screw part 11a It is possible to suppress the breakage by improving the strength of the vertebrae, and to improve the strength of bonding to the vertebrae.

(Third embodiment)
Next, a third embodiment of the present invention will be described. The bone anchor unit for spinal fixation according to the third embodiment (hereinafter simply referred to as “bone anchor unit of the third embodiment”) is used in the same manner as the bone anchor unit 1 of the first embodiment. And the bone anchor unit of 3rd Embodiment is comprised similarly to the bone anchor unit 1 of 1st Embodiment, and is provided with the bone screw, the insert member, and the housing member. However, the bone anchor unit of the third embodiment is different from the first embodiment in the mechanism for positioning the insert member in the housing member. In the following, the same components as those in the first embodiment are denoted by the same reference numerals in the drawings, the description thereof is omitted, and components different from those in the first embodiment will be described.

  In the bone anchor unit of the third embodiment, the bone screw similar to the bone screw 11 of the first embodiment, the housing member 33 shown in FIGS. 13 to 15, and the insert member 32 shown in FIGS. 16 and 17 are included. Is provided. FIG. 13 is a perspective view of the housing member 33, and is a perspective view showing the orientation changed in FIGS. 13 (a) and 13 (b). FIG. 14 is a plan view (FIG. 14A), a front view (FIG. 14B), and a side view (FIG. 14C) of the housing member 33. 15 is a cross-sectional view taken along line FF in FIG. 14B (FIG. 15A) and a cross-sectional view taken along line GG in FIG. 14C (FIG. 15B). . 13 to 15 show the housing member 33 in a state before being assembled as the bone anchor unit of the third embodiment.

  As shown in FIGS. 13 to 15, the housing member 33 is provided with one end side opening 14, the other end side opening 15, a female screw portion 16, a bifurcated portion 20, and the like, similarly to the housing member 13 of the first embodiment. ing. However, the housing member 33 is provided with a recess 34 in a form different from that of the recess 17 of the first embodiment. The concave portion 34 is provided as a circular through hole that communicates the inner peripheral side and the outer peripheral side in each of the forked portions 20 of the housing member 33. And the part opened inside in the recessed part 34 comprises the recessed part 34a formed in the inner periphery of the housing member 33 at the recessed part. On the other hand, the portion of the concave portion 34 that opens to the outside constitutes an open portion 34 b that communicates with the concave portion 34 a and is open at the outer periphery of the housing member 33. The concave portion 34 is also configured to be used as a through hole for holding the bone anchor unit of the third embodiment by a predetermined instrument in the housing member 33 during the operation of fixing the spine. In this housing member 33 as well as the housing member 13 of the first embodiment, after the head of the bone screw is inserted from one end side, the end portion 19 on one end side of the housing member 33 is caulked inward. Thus, the end 19 on one end side of the head is configured to be locked.

  FIG. 16 is a perspective view of the insert member 32. 17 is a plan view of the insert member 32 (FIG. 17 (a)), a front view (FIG. 17 (b)), a side view (FIG. 17 (c)), and HH in FIG. 17 (a). FIG. 18 is a cross-sectional view taken along the line arrow (FIG. As shown in FIGS. 16 and 17, the insert member 32 is provided with a rod seat portion 21 having a recessed surface 21a, a head contact surface 23, and the like, like the insert member 12 of the first embodiment. 33 is disposed inside. However, unlike the insert member 12 of the first embodiment, the insert member 32 is provided with a flexible portion 35, and engages with a recessed portion 34 a of the recessed portion 34 in the housing member 33 on the distal end side of the flexible portion 35. A convex portion 36 is provided.

  A pair of the flexible portions 35 are provided at positions facing each other across the rod seat portion 21, and each piece toward the other end side on the outer peripheral side of the insert member 32 with respect to the main body portion provided with the rod seat portion 21. It is formed to extend like a hand. In addition, a tapered surface is provided on the inner side of each flexible portion 35 so as to incline outward toward the other end side which is the front end side. Thereby, each flexible part 35 is formed so that thickness may become thin toward the front end side, and rigidity may become small, and it is formed so that elastic deformation is possible so that it may bend at least inside. Further, the convex portions 36 that engage with the concave portions 34 of the housing member 33 are formed so as to protrude outward on the outer periphery of the distal end side of each flexible portion 35.

  When the insert member 32 is disposed inside the housing member 33, the insert member 32 is flexible from one end side (that is, flexible) with the position of the convex portion 36 corresponding to the position of the concave portion 34 in the circumferential direction of the housing member 33. The housing member 33 is inserted into the one end side opening 14 (from the front end side of the portion 35). When the insert member 32 is inserted from the one end side opening 14, first, since the convex portion 36 interferes with the inner periphery of the housing member 33, the flexible portion 35 bends inward. When the insert member 32 is further inserted toward the other end side from the one end side opening 14, the flexible portion 35 is elastically recovered after being bent inward, and the convex portion 36 is engaged with the concave portion 34. Become. As a result, the insert member 32 is positioned at a predetermined position inside the housing member 33. When the rod member is inserted between the bifurcated portion 20 in the other end side opening 15 of the housing member 33, the outer periphery of the rod-shaped portion with respect to the recessed surface 21 a of the rod seat portion 21 in the insert member 32 is It will be supported to fit properly.

  In addition, the bone anchor unit of 3rd Embodiment is manufactured by the manufacturing method similar to the manufacturing method of the bone anchor unit 1 of 1st Embodiment. However, in the method for manufacturing the bone anchor unit of the third embodiment, in the housing member forming step, the housing member 33 provided with the concave portion 34 as a circular through hole is formed, and in the insert member forming step, it protrudes toward the distal end side. The insert member 32 including the flexible portion 35 provided with the portion 36 is formed.

  According to the bone anchor unit of the third embodiment described above, as with the bone anchor unit 1 of the first embodiment, it is possible to reduce the number of parts and suppress the complexity of the structure, and to engage the vertebra in the bone screw. It is possible to prevent the structure of the portion to be restricted from being restricted by the relationship with the dimensional configuration of the housing member 33.

  Further, according to the bone anchor unit of the third embodiment, the insert member 32 is provided with the flexible portion 35 that extends in a cantilevered manner with respect to the main body portion and has the convex portion 36 formed on the distal end side. A configuration in which the convex portion 36 is engaged with the concave portion 34 using the recovery force can be realized with a simple structure. Also in the housing member 33, the concave portion 34 having a simple structure can be realized as a through hole that communicates the inner peripheral side and the outer peripheral side. Thereby, the mechanism for positioning the insert member 32 in the housing member 33 can be formed with a very simple structure. And after inserting the insert member 32 from the one end side opening 14 of the housing member 33 and bending the flexible part 35 inside, while confirming from the outer side of the housing member 33 through the recessed part 34 of a through-hole, it is flexible. The portion 35 can be elastically recovered and the convex portion 36 can be easily engaged with the concave portion 34. Thereby, the operation | work which positions the insert member 32 inside the housing member 33 can be performed very easily. Further, it is possible to realize a positioning mechanism in which the housing member 33 is not deformed.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. FIG. 18 is an exploded perspective view showing a spinal fixation bone anchor unit 4 (hereinafter simply referred to as “bone anchor unit 4”) according to a fourth embodiment of the present invention. Similar to the bone anchor unit 1 of the first embodiment, the bone anchor unit 4 holds the rod member 101 arranged along the spinal column and is arranged in an engaged state with the spine to fix the spine. Used in And the bone anchor unit 4 is provided with the bone engaging member, the insert member 12, and the housing member 13 similarly to the bone anchor unit 1 of 1st Embodiment. However, the bone anchor unit 4 is different from the first embodiment in that the bone engaging member is configured not as a bone screw but as a bone hook 41. Hereinafter, the same reference numerals in the drawings denote the same components as those in the first embodiment, and a description thereof will be omitted, and a bone hook 41 different from that in the first embodiment will be described.

  As shown in FIG. 18, the bone hook 41 which is a bone engaging member has a hook portion 41a formed on one end side and a head portion 41b formed on the end portion on the other end side. The head 41b is formed in the same manner as the head 11b of the bone screw 11 of the first embodiment. And after the head part 41b is inserted from the one end side opening 14 of the housing member 13, the edge part 19 of the one end side in the housing member 13 is crimped inside, and the edge part 19 of the one end side is compared with the head part 41b. It is configured to lock. On the other hand, the hook portion 41a is formed in a claw shape that engages with the vertebra of the spine while sandwiching the vertebra. The hook portion 41a is formed with a size larger than the head portion 41b as a whole.

  In the operation of fixing the spine, the insert member 12 is disposed inside the housing member 13 and the head 41b of the bone hook 41 is assembled in a state where the head portion 41b is crimped to the end portion 19 on one end side of the housing member 13. An anchor unit 4 is used. The surgeon first engages the bone hook 41 with the vertebra of the spine by being sandwiched by the hook portion 41a. Thereafter, as in the first embodiment, the rod-shaped portion 101a of the rod member 101 is inserted from the other end side opening 15 of the housing member 13, and this rod-shaped portion 101a is inserted into the rod seat portion 21 of the insert member 12. It arrange | positions so that it may contact | abut to the concave surface 21a. In this state, the fixing nut 104 is screwed and attached to the female screw portion 16 on the other end side of the housing member 13, and the rod-shaped portion 101a is pressed against the rod seat portion 21 and fixed. As a result, the rod member 101 is held by the bone anchor unit 4 and the spine 100 is fixed.

  In addition, the bone anchor unit 4 is manufactured by the manufacturing method similar to the manufacturing method of the bone anchor unit 1 of 1st Embodiment. However, in the manufacturing method of the bone anchor unit 4, the bone hook 41 provided with the hook portion 41a is formed in the bone engaging member forming step.

  Also in the bone anchor unit 4 demonstrated above, there can exist an effect similar to the bone anchor unit 1 of 1st Embodiment. That is, according to the bone anchor unit 1, the bone anchor unit 1 can be composed of three parts, ie, the bone hook 41, the insert member 12, and the housing member 13, and the number of parts can be reduced to prevent the structure from being complicated. And according to the bone anchor unit 4, it can prevent that the structure of the part engaged with the vertebra in the bone hook 41 receives restrictions with respect to the dimension structure of the housing member 13. FIG.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, the following modifications may be made.

(1) A plurality of slits may be formed at one end of the housing member so that the housing member can be easily caulked. In addition, a claw portion that is bent at the end portion on one end side of the housing member is formed, and the claw portion is bent after the head portion of the bone engagement member is inserted from the opening on the one end side. However, the end of one end of the housing member may be locked. Further, the head-facing concave portion provided on the inner periphery of the end portion on the one end side of the housing member may not be provided as a curved surface portion, and may be variously provided such as a groove-like portion or a hollow-like portion. The shape can be selected.

(2) About the structure of the one end side in a bone engaging member, you may engage with a spine with structures other than a screw part and a hook part. For example, a double screw structure, a bone cement injection structure, or a structure using a spring is provided on one end side of the bone engaging member, so that one end side of the bone engaging member is embedded in the vertebra and then the vertebra The size of the portion existing inside the vertebra may be enlarged and engaged with the vertebra.

(3) The insert member is not necessarily inserted into the housing member from the one end side opening, but may be inserted from the other end side opening. Moreover, you may implement by changing a shape and a position suitably about the convex part of an insert member, and the recessed part of a housing member. A plurality of convex portions and concave portions may be provided. Moreover, in 3rd Embodiment, about the flexible part provided in an insert member, not only what extends toward the other end side from the main-body part of an insert member but it is formed so that it may extend toward one end side. There may be.

(4) The housing member may not be configured to engage with a fixing member formed as a nut member on the inner peripheral side, but may be configured to engage with a fixing member other than the nut member or engaged on the outer peripheral side. It may be configured to.

  The present invention includes a bone anchor unit for spinal fixation that fixes a spine by holding a rod member that has at least a rod-like portion and is arranged along the spinal column and is engaged with the spine, and As its manufacturing method, it can be widely applied.

It is a figure showing the state where the bone anchor unit for spinal fixation concerning a 1st embodiment of the present invention is used in order to fix the spine. It is the front view and side view of a bone anchor unit for spinal fixation shown in FIG. It is sectional drawing of the bone anchor unit for spinal fixation shown in FIG. It is sectional drawing which shows the state holding the rod member of the bone anchor unit for spinal fixation shown in FIG. It is a disassembled perspective view of the bone anchor unit for spinal fixation shown in FIG. It is the front view and sectional drawing of a bone screw in the bone anchor unit for spinal fixation shown in FIG. It is a perspective view of the housing member in the bone anchor unit for spinal fixation shown in FIG. FIG. 8 is a plan view, a front view, a side view, and a bottom view of the housing member shown in FIG. 7. It is sectional drawing of the housing member shown in FIG. It is the top view, front view, and sectional drawing of an insert member in the bone anchor unit for spinal fixation shown in FIG. It is process drawing which shows the manufacturing method of the bone anchor unit for spinal fixation shown in FIG. It is sectional drawing of the bone anchor unit for spinal fixation which concerns on 2nd Embodiment of this invention. It is a perspective view of the housing member in the bone anchor unit for spinal fixation concerning a 3rd embodiment of the present invention. FIG. 14 is a plan view, a front view, and a side view of the housing member shown in FIG. 13. It is sectional drawing of the housing member shown in FIG. It is a perspective view of the insert member in the bone anchor unit for spinal fixation concerning a 3rd embodiment of the present invention. FIG. 17 is a plan view, a front view, a side view, and a cross-sectional view of the insert member shown in FIG. 16. It is a disassembled perspective view of the bone anchor unit for spinal fixation concerning 4th Embodiment of this invention.

Explanation of symbols

1 Bone anchor unit for spinal fixation 11 Bone screw (bone engaging member)
12 Insert member 13 Housing member 14 One end side opening 15 Other end side opening 19 One end side end 21 Rod seat portion 100 Spine 100a Vertebral bone 101 Rod member 101a Rod-shaped portion 104 Fixing nut (fixing member)

Claims (12)

A bone anchor unit for spinal fixation that fixes a spine by holding a rod member that is arranged along the spinal column with at least a rod-shaped portion and that is arranged in a state of being engaged with the spine,
A bone engaging member engaged at one end side with respect to the vertebra of the spine;
A head provided at one end side opening at one end side and a second end side opening opened at the other end side and communicating with the one end side opening, and provided at the other end side end portion of the bone engaging member In a state where the portion is inserted from the one end side opening, the housing member that the end portion on one end side is locked to the head,
An insert member disposed on the inner side of the housing member, wherein at least part of one end abuts against the head, and a rod seat part at least part abuts against the rod-like part is provided on the other end side; ,
With
The bone engaging member is engaged with a vertebra, and the rod-like portion of the rod member inserted from the other end side opening is disposed so as to contact the rod seat portion, and the other end side of the housing member A spinal fixation bone characterized by holding the rod member and fixing the spine by attaching a fixing member that engages with and inserts the rod-shaped portion against the insert member. Anchor unit. The bone anchor unit for spinal fixation according to claim 1,
After the head is inserted from the opening on the one end side, the end on the one end side of the housing member is caulked inward so that the end on the one end side is locked to the head. A bone anchor unit for spinal fixation. The bone anchor unit for spinal fixation according to claim 2,
A head-facing concave portion formed on the inner periphery of the end portion on one end side of the housing member so as to be recessed at a position facing the periphery of the head portion when the end portion on the one end side is caulked inward. A bone anchor unit for spinal fixation, comprising: The bone anchor unit for spinal fixation according to claim 3,
The head-facing concave portion is provided as a curved portion that abuts along the periphery of the head when an end on one end side of the housing member is crimped inward. Bone anchor unit for fixation. The bone anchor unit for spinal fixation according to any one of claims 1 to 4,
The rod seat portion is formed in a groove shape having a concave surface curved along a part of the outer periphery of the rod-shaped portion that comes into contact,
The outer periphery of the insert member is provided with a convex portion formed so as to protrude outward,
The housing member is formed with a recess on the inner periphery of the housing member and engages with the protrusion, and communicates with the recess and at least one of an outer periphery and an end on one end side of the housing member. A bone anchor unit for spinal fixation, characterized in that a recess having an open portion formed to be opened on one side is provided. The bone anchor unit for spinal fixation according to claim 5,
The insert member is provided with a flexible portion that is elastically deformable so as to extend toward one end side or the other end side on the outer peripheral side and bend toward the inside, and has the convex portion formed on the tip end side. And
The recess is formed so that the open portion is opened at the outer periphery of the housing member, and is provided as a through hole that communicates the inner peripheral side and the outer peripheral side of the housing member;
The insert member is inserted into the housing member from the opening on the one end side, and elastically recovers after the flexible portion is bent inward so that the convex portion engages with the concave portion. Bone anchor unit for spinal fixation. The bone anchor unit for spinal fixation according to claim 5,
The concave portion is formed so that the open portion is opened at an end portion on one end side of the housing member, and the concave portion is formed in a groove shape extending from one end side toward the other end side in the inner periphery of the housing member. Formed,
The bone anchor unit for spinal fixation, wherein the insert member is inserted from the opening on the one end side with respect to the housing member while the convex portion is moved in sliding contact with the concave portion. The bone anchor unit for spinal fixation according to any one of claims 1 to 7,
A bone anchor unit for spinal fixation, wherein the bone engaging member is formed with a screw portion that is engaged with and engaged with a vertebra on one end side. The bone anchor unit for spinal fixation according to claim 8,
A bone anchor unit for spinal fixation, wherein a diameter dimension of an outermost peripheral part of the screw part is larger than a maximum diameter dimension of the head in a direction perpendicular to an axial direction of the screw part. The bone anchor unit for spinal fixation according to claim 8 or 9,
The spinal fixation bone, wherein a diameter dimension of an outermost peripheral part of the screw part is larger than a minimum diameter dimension of the one end side opening in which an end part on one end side of the housing member is locked to the head part. Anchor unit. Spinal fixation for manufacturing a bone anchor unit for spinal fixation that holds a rod member arranged along the spinal column with at least a rod-shaped portion and that is arranged in engagement with the spine to fix the spine. A method for manufacturing a bone anchor unit for
A bone engaging member forming step of forming a bone engaging member engaged at one end side with respect to the vertebra of the spine;
An insert member forming step of forming an insert member provided with a rod seat part at least partially contacting the rod-shaped part;
One end side opening that opens on one end side, and the other end side opening that opens on the other end side and communicates with the one end side opening and into which the rod-shaped portion of the rod member is inserted. Forming a housing member that is attached so that a fixing member that presses and fixes the shaped portion against the rod seat portion of the insert member is engaged with the other end side; and
An insert member arranging step of arranging the insert member inside the housing member;
The head provided at the other end of the bone engaging member is inserted into the housing member from the opening on the one end so as to be able to contact at least part of one end of the insert member, and the housing A caulking step of locking the end on one end side with respect to the head by caulking the end on one end side of the member;
A method for manufacturing a bone anchor unit for spinal fixation, comprising: A method for producing a bone anchor unit for spinal fixation according to claim 11,
In the insert member forming step, a convex portion projecting outward is formed on the outer periphery of the insert member, and the rod seat portion extends along a part of the outer periphery of the rod-shaped portion that comes into contact. Formed into a groove shape having a curved concave surface,
In the housing member forming step, a recessed portion is formed so as to be recessed in the inner periphery of the housing member, and communicates with the recessed portion and opens to at least one of an outer periphery and one end side end of the housing member. An open part is formed,
In the insert member arranging step, the insert member is arranged inside the housing member in a state where the convex portion is engaged with the concave portion, and the method for producing a bone anchor unit for spinal fixation,

Images