Osteosynthesis system

Abstract

To provide an osteosynthesis system including an osteosynthesis tool and a blade engaging body, for reducing a work burden during surgery.SOLUTION: An osteosynthesis system including a fixture, an osteosynthesis tool, and a blade engaging body, includes a movement / engagement structure between the outer peripheral surface of the osteosynthesis tool and the blade engaging body, the movement / engagement structure engaging the osteosynthesis tool and the blade engaging body around an axis in a mounted state, and allowing the blade engaging body to move in the axial direction between a standby position and a functional position relative to the osteosynthesis tool. The blade engaging body is so configured that when the blade engaging body is disposed at the standby position, an engagement fin does not protrude from the osteosynthesis tool in a mounted state where it does not interfere with introduction of the osteosynthesis tool into the bone, and that when the blade engaging body is disposed at the functional position, the engagement fin protrudes from the osteosynthesis tool in a mounted state where the blade engagement body is engaged with the osteosynthesis tool around the axis.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a bone fixation system.

Background Art

[0002] Conventionally, a bone fixation system including a bone fixation device (lag screw) introduced through a transverse hole of an intramedullary nail has been known. In this bone fixation system, particularly when used to support a femoral neck fracture at the proximal end of the femur, in order to prevent the femoral head into which the bone fixation device is introduced at the center from rotating, in order to enhance the engaging force of the femoral head with respect to the axis of the bone fixation device, it is known to additionally insert a blade engaging body (fork-shaped blade, key ring, blade body).

[0003] Here, the bone fixation device and the blade engaging body are introduced into the bone through a transverse hole penetrating in a direction intersecting the axis of an intramedullary nail (nail) inserted into the medullary cavity of the bone, and may be used in an intramedullary fixation system which is a kind of bone fixation system (for example, see Patent Documents 1-3). Further, the bone fixation device and the blade engaging body may be used in a CHS (compression hip screw) system or the like in a manner of being inserted through a bone plate fixed on the outside of the bone (for example, see Patent Document 4).

[0004] In various bone fixation systems as described above, after the bone fixation device is introduced into the bone, the blade engaging body is inserted along the axis on the outer peripheral surface of the bone fixation device, and finally, the operation is performed in a procedure of attaching the proximal end portion of the blade engaging body to the proximal end portion of the bone fixation device by an attachment member such as a fixing screw. As a result, the engaging fins provided on the blade engaging body protrude around the bone engaging portion of the bone fixation device, so that the engaging force of the bone fixation device with respect to the bone, particularly the resistance to the rotation of the bone around the axis of the bone fixation device, can be enhanced.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] By the way, in the above conventional bone fixation system, it is necessary to sequentially perform three operations: the operation of introducing a bone fixation device through a transverse hole of a fixture such as an intramedullary nail or a bone plate, the operation of inserting a blade engaging body, and the operation of attaching the blade engaging body to the bone fixation device. Alternatively, when introducing the bone fixation device and the blade engaging body, it is necessary to insert the blade engaging body while aligning the key angle position with respect to the transverse hole of the fixture and align the angle position of the bone fixation device after introduction with the blade engaging body. Therefore, there is a problem that the operation during surgery is complicated and time-consuming.

[0007] Therefore, the present invention addresses the above problems, and its object is to reduce the work load during surgery in a bone fixation system including a bone fixation device introduced through a transverse hole of a fixture and a blade engaging body. [Means for Solving the Problems]

[0008] To solve the above problems, the bone fixation system according to the present invention includes a fixture that is installed on a first bone portion and has a detachable locking mechanism for locking a transverse hole directed toward a second bone portion and a member inserted through the transverse hole around an axis, a bone fixation tool that is introduced through the transverse hole toward the second bone portion and has a bone engaging portion provided on a tip side in the axial direction and engaging with the second bone portion and a shaft portion provided on a rear end side in the axial direction, a blade engaging body that is provided on a tip side in the axial direction and has an engaging fin and a support portion provided on a rear end side in the axial direction for integrally supporting the engaging fin and is configured to be attachable to an outer peripheral surface of the bone fixation tool, and a moving engagement structure is provided between the outer peripheral surface of the bone fixation tool and the blade engaging body to engage the bone fixation tool and the blade engaging body around the axis and allow movement in the axial direction between a standby position on the rear end side in the axial direction and a functional position on the tip side in the axial direction of the blade engaging body with respect to the bone fixation tool in a mounted state. The blade engaging body is configured such that when disposed in the standby position in the mounted state, the engaging fin does not protrude from the bone fixation tool in a state that does not prevent introduction of the bone fixation tool and the blade engaging body into the bone through the transverse hole, and the blade engaging body is configured such that when disposed in the functional position in the mounted state, the engaging fin protrudes from the bone fixation tool.

[0009] According to the present invention, when the blade engaging body is disposed at the standby position when mounted on the outer peripheral surface of the bone fixture, the engaging fins do not protrude from the bone fixture in a state that does not prevent introduction into the bone through the transverse hole together with the bone fixture. Therefore, the blade engaging body mounted on the bone fixture at the standby position can be introduced into the bone through the transverse hole of the fixture without any trouble. Then, when the blade engaging body is moved from the standby position to the functional position on the tip side in the axial direction using the moving engagement structure by an external operation, the engaging fins of the blade engaging body protrude from the bone fixture and engage with the intraosseous tissue. Therefore, in the bone joining system according to the present invention, the blade engaging body together with the bone fixture can be introduced into the bone through the transverse hole of the fixture, and after the bone fixture is introduced into the bone, by simply moving the blade engaging body from the standby position to the functional position, since the engaging fins protrude from the bone fixture in a state where the bone fixture and the blade engaging body are engaged around the axis, it becomes possible to enhance the engaging force against the bone, particularly the torsional resistance around the axis.

[0010] In the present invention, it is preferable to have positioning and holding means for holding the blade engaging body at the standby position. According to this, since the blade engaging body is held at the standby position by the positioning and holding means, when introducing the bone fixing device in the mounted state and the blade engaging body into the bone, the blade engaging body mounted on the outer peripheral surface of the bone fixing device may deviate from the standby position due to resistance received during introduction from surrounding tissues, other implants such as intramedullary nails and bone plates, tools, etc. This risk can be reduced. Here, the above-mentioned positioning and holding means may be constituted by an axial engagement structure formed between the bone fixing device and the blade engaging body. In this case, it is desirable that the above-mentioned positioning and holding means is constituted by an engagement structure between an axial step provided on the outer peripheral surface of the bone fixing device and an axial step provided on a portion facing the outer peripheral surface of the blade engaging body. In particular, it is more desirable that the above-mentioned positioning and holding means holds the standby position of the blade engaging body on both the front end side and the rear end side in the axial direction. In this case, as the above-mentioned engagement structure, it is desirable to include both an engagement structure for holding on the front end side in the axial direction and an engagement structure for holding on the rear end side in the axial direction. Further, when further comprising an introduction tool for introducing the bone fixing device in the mounted state and the blade engaging body, the above-mentioned positioning and holding means may be formed between the blade engaging body and the introduction tool. At this time, as the above-mentioned positioning and holding means, it is desirable that the engagement structure is constituted between the introduction tool connected to the bone fixing device and the blade engaging body.

[0011] In the present invention, it is desirable that the movement engagement structure is provided between the outer peripheral surface and the support portion. According to this, by providing the movement engagement structure between the outer peripheral surface of the bone fastener and the support portion of the blade engaging body, it is possible to configure the movement engagement structure in the support portion of the blade engaging body where it is easy to increase the rigidity, so it is facilitated to ensure the rigidity of the movement engagement structure. At this time, it is more desirable that the movement engagement structure includes a guiding structure that guides the movement of the blade engaging body from the standby position to the functional position. According to this, the movement operation of the blade engaging body from the standby position to the functional position can be further facilitated by the movement engagement structure including the guiding structure.

[0012] In the present invention, it is preferable that a longitudinal groove that fits into the engagement fin is provided on the outer peripheral surface of the bone fastener so as to be movable in the axial direction. Here, it is desirable that the longitudinal groove extends in the axial direction and is a guiding groove that guides the engagement fin when the blade engaging body moves from the standby position to the functional position. At this time, it is more desirable that the longitudinal groove has a groove bottom portion that inclines toward the outer peripheral side toward the bone engaging portion, and the engagement fin projects toward the outer peripheral side of the bone engaging portion when the blade engaging body moves from the standby position to the functional position. At this time, it is further desirable that the tip of the engagement fin is disposed on the groove bottom portion when the blade engaging body is disposed at the standby position.

[0013] In the present invention, it is preferable to further include a compression member that engages both the bone fixing device and the blade engaging body from the rear end side in the axial direction and can pull the bone fixing device rearward in the axial direction with respect to the blade engaging body. According to this, since the compression member can pull the bone fixing device rearward in the axial direction with respect to the blade engaging body, reduction can be performed by the compression force of the compression member when a gap occurs in the fracture part. Also, by correcting the position of the bone fixing device in the axial direction, it is possible to adjust the protruding state of the engaging fins of the blade engaging body. Here, it is preferable that a movement limit is set on the front end side in the axial direction of the blade engaging body in the mounted state with respect to the bone fixing device. According to this, by setting the functional position of the blade engaging body to the movement limit with respect to the bone fixing device, an axial force can be applied to the pulling of the bone fixing device with respect to the blade engaging body by the compression member, so that the stability of the assembly composed of the bone fixing device and the blade engaging body can be enhanced. Also, when the compression member is constituted by a compression screw, loosening of the screw can be reduced by the above axial force. Here, it is desirable that the movement limit is constituted by the contact of the leading edge of the support portion continuous with the base portion of the engaging fin and the rear edge of the bone engaging portion. Incidentally, the above compression member can also be used as positioning and holding means for positioning and holding the functional position of the fin engaging body with respect to the bone fixing device.

[0014] In the present invention, it includes an introducing tool connected to the rear part of the bone fixing device, and a pressing tool movably mounted in the axial direction with respect to the introducing tool and capable of pressing the rear part of the blade engaging body. The introducing tool is configured to be able to introduce the bone fixing device and the blade engaging body arranged at the standby position into the bone, and it is preferable that the pressing tool is configured to be able to move the blade engaging body to the functional position by moving it to the front end side in the axial direction.

[0015] In the present invention, the fixture is an intramedullary nail that is inserted into the medullary cavity of a bone and has the transverse hole that penetrates in a direction intersecting the axis. It is preferable that the assembly of the bone fastener and the blade engaging body is configured to be lockable by the locking mechanism. In this case, the intramedullary nail further includes an axial hole communicating with the transverse hole, and it is desirable that the locking mechanism is housed inside the axial hole and is configured to be able to lock the assembly inside the transverse hole. Here, depending on the locking relationship between the locking mechanism and the locked structure, not only can the blade engaging body and the bone fastener be locked around the axis with respect to the intramedullary nail, but they may also be fixed in the axial direction.

[0016] In the present invention, it is preferable that the blade engaging body has a locked structure that is locked around the axis by the locking mechanism within a range disposed inside the transverse hole when it is disposed at the functional position at least in the mounted state with respect to the bone fastener. According to this, since the blade engaging body disposed at the functional position engages around the axis with respect to the bone fastener, when the locked structure of the blade engaging body is locked by the locking mechanism, the bone fastener and the blade engaging body are fixed around the axis with respect to the intramedullary nail. At this time, by providing a locked structure that is locked by the locking mechanism on the blade engaging body, there is no need to provide an opening region in the portion disposed inside the transverse hole of the blade engaging body in order to lock the locking mechanism to the bone fastener as in the conventional structure, so that the rigidity of the entire blade engaging body can be increased. As a result, the support rigidity of the engaging fins can also be improved. Here, it is desirable that the locked structure is provided on the support portion, and it is more desirable that it is an engaging recess (engaging groove) that engages around the axis with respect to the locking tip of the locking mechanism.

Advantages of the Invention

[0017] According to the present invention, in a bone fixation system including a fixture, a bone fastener, and a blade engaging body, by movably mounting the blade engaging body mounted to the bone fastener via a moving engagement structure from a standby position to a functional position, the working burden during surgery can be significantly reduced.

[0018] In particular, by providing positioning and holding means for holding the blade engaging body attached to the bone fixation device in the standby position, when introducing the bone fixation device through the transverse hole of the fixing device together with the blade engaging body, the risk that the blade engaging body attached to the outer peripheral surface of the bone fixation device deviates from the standby position due to resistance received during introduction from the surrounding tissue or the intramedullary nail can be reduced.

Brief Description of the Drawings

[0019]

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Mode for Carrying Out the Invention

[0020] Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, the overall configuration of the bone fixation system 100 according to the present invention will be described. Here, before describing the bone fixation system 100, the conventional bone fixation system 50 will be described with reference to FIG. 20. FIG. 20 shows an intramedullary nail 110 constituting a bone fixation system 50 having a conventional structure, and a bone fixation tool (such as a sleeve-attached lag screw or an extra screw) 120 introduced into the bone through the transverse holes 111 and 112 of the intramedullary nail 110. In the illustrated bone fixation system 50, an intramedullary nail 110 and a bone fixation tool 120 for treating a proximal femoral fracture are shown. The femur B10 has a shaft portion B11 and a proximal portion B12, and in the proximal portion B12, there are a femoral neck portion B13, a femoral head portion B14, a greater trochanter portion B15, and the like.

[0021] The intramedullary nail 110 is provided with axial holes that communicate internally with the transverse holes 111 and 112, and these axial holes open at the proximal end of the intramedullary nail 110. At this proximal end, it is connected to a connection end portion 131a of a target device 131 included in a surgical instrument 130. In this connected state, the intramedullary nail 110 is introduced into the body through an incision and inserted into the medullary cavity through an opening drilled in the greater trochanter portion B15 of the femur B10. The target device 131 is provided with an aiming portion 131b at a position opposing the outside of the patient, and guide sleeves 132 and 133 are attached to the aiming portion 131b. By using an introduction tool such as a T-wrench 137 through these guide sleeves 132, 133, and a holder 136, guide pins 134, 135 and a bone fixation tool 120 are inserted through the transverse holes 111, 112 and introduced into the femoral neck portion B13 and the femoral head portion B14.

[0022] The bone fixation system 100 of the present embodiment includes an intramedullary nail 110 corresponding to the same fixture used in the conventional bone fixation system 50 described above, and various tools used together with the target device 131 and the guide sleeves 132, 133. However, in the bone fixation system 100, instead of the bone fixation tool 120, it includes a bone fixation tool (lag screw) 140 shown in FIG. 7(b) and a blade assembly 150 shown in FIG. 7(a). Note that FIG. 19 shows a T-trench 137 and a central axis 138, which are introduction tools commonly used in the conventional bone fixation system 50, and these are also included in the bone fixation system 100 of the present embodiment. Furthermore, the bone fixation system 100 also includes a compression nut sleeve 139 shown in FIG. 19, which is a pressing tool for pushing the blade assembly 150 from a standby position described later to a functional position after introducing the bone fixation tool 140 and the blade assembly 150. This pressing tool, the compression nut sleeve 139, is coaxially mounted with the aforementioned introduction tools, the T-trench 137 and the central axis 138. In the illustrated example, the compression nut sleeve 139 is mounted on the outer periphery of the T-trench 137 in a manner movable in the axial direction with the T-trench 137 inserted therethrough.

[0023] In the present embodiment, as shown in FIG. 1, in the intramedullary nail 110, a locking mechanism 110L including an operating member (set screw) 114, a holding member (holding nut) 115, and an engaging member (engaging pin) 116 is provided inside the axial hole 113 communicating with the transverse holes 111, 112. Here, the connection end portion 131a of the aforementioned target device 131 is connected to the opening 113a of the axial hole 113 via a connecting bolt or the like (not shown). A female thread is provided on the inner surface of the axial hole 113, and the holding member 115 is screwed onto this female thread. Note that, except for FIG. 20, in FIGS. 1 - 6, FIGS. 10 - 12, FIG. 14, and FIG. 15, only the proximal portion of the intramedullary nail 110 is shown, the distal portion is omitted, and only the contour close to the proximal portion is shown by a dotted line.

[0024] In the locking mechanism 110L, an operating member 114 is screwed onto a holding member 115, and the operating member 114 is configured to move up and down by rotating the operating member 114 with a tool or the like through the opening 113a. Below the operating member 114, an engaging member 116 biased upward by an elastic member such as a coil spring (not shown) in a rotationally locked state is accommodated in the shaft hole 113 so as to be movable up and down. The engaging member 116 is configured to move up and down together with the up and down movement of the operating member 114 by being brought into contact with the lower end of the operating member 114 by the biasing of the elastic member. The engaging member 116 has a locking tip 116a at the lower end for locking a member that protrudes into the transverse hole 111 and is inserted through the transverse hole 111. Further, the engaging member 116 has a slightly vertically elongated insertion hole 116b in a portion disposed inside the transverse hole 112, whereby an osteosynthesis device such as an extra screw can be introduced into the bone through the transverse hole 112. The locking mechanism 110L is configured to be capable of engaging and disengaging a member inserted through the transverse hole 111, such as an assembly of the osteosynthesis device 140 and the blade engaging body 150.

[0025] In this embodiment, main feature points are provided on the bone fastener 140 introduced through the transverse hole 111 of the intramedullary nail 110 and the blade engaging body 150 attached to the bone fastener 140. As shown in FIGS. 7(b) and 8(b), the bone fastener 140 of this embodiment has a bone engaging portion 141 provided on the tip side in the axial direction, a shaft portion 142 provided on the rear end side in the axial direction, and a rear end portion 143 formed at the rear end of the shaft portion 142. The bone engaging portion 141 may be provided with any engaging structure that engages within the bone. In the case of the illustrated example, preferably, it has a screw structure with a tapping screw function. The shaft portion 142 includes a longitudinal groove 142a extending in the axial direction and an engaging rib 142b extending in the axial direction. A plurality of (four in the illustrated example) longitudinal grooves 142a are provided around the axis and are preferably arranged at equal intervals around the axis. The longitudinal groove 142a has a groove structure with a substantially constant depth in the portion formed in the shaft portion 142. However, at the tip portion 142a1 that extends from the shaft portion 142 toward the tip side in the axial direction and reaches the rear portion of the bone engaging portion 141, the groove bottom surface is inclined toward the outer peripheral side toward the tip side in the axial direction so that the depth gradually decreases toward the tip side in the axial direction. Also, a plurality of (four in the illustrated example) engaging ribs 142b are provided around the axis and are preferably arranged at equal intervals around the axis. In the case of the illustrated example, the engaging rib 142b is formed on the outer peripheral surface where the longitudinal groove 142a is not formed, but it is not particularly limited thereto. The bone fastener 140 is provided with a shaft hole (see FIGS. 2 and 4, etc.) through which a guide pin can be inserted. The rear end portion 143 has an end structure including a screwing portion with a female screw formed at the rear end of this shaft hole and a tool engaging portion that can engage with a tool such as a hexagonal hole shape.

[0026] On the one hand, as shown in FIGS. 7(a) and 8(a), the blade assembly 150 includes an engagement fin 151 provided on the tip side in the axial direction, a support portion 152 provided on the rear end side in the axial direction and integrally supporting the engagement fin 151 from behind, and a rear end portion 153 further behind the support portion 152. The engagement fins 151 are preferably provided in a plurality (four in the illustrated example) around the axis. In particular, it is desirable that the plurality of engagement fins 151 are formed at equal intervals and in a rotationally symmetric shape around the axis. The shape of the engagement fin 151 is a rectangular bar extending in the axial direction (more specifically, a rod-shaped body having a planar shape in which a paper or cloth constituting the fan surface of a fan is opened in cross section). The support portion 152 is a cylindrical (more specifically, a circular cylindrical) portion that supports the plurality of engagement fins 151 integrally. An engagement groove (not shown) engageable with the engagement rib 142b is formed on the inner peripheral surface of the support portion 152. This engagement groove is formed so as to extend from the leading edge portion on the leading end side in the axial direction of the support portion 152 toward the rear end side in the axial direction at an angular position adjacent to the base of the engagement fin 151. When the blade assembly 150 is inserted into the bone fastener 140 from the rear to the front in the axial direction so that the engagement groove engages with the engagement rib 142b, the blade assembly 150 engages (fixes) around the axis with respect to the bone fastener 140 and is in a state where it can move (slide) in the axial direction. That is, the engagement rib 142b and the engagement groove constitute at least a part of the above-described moving engagement structure.

[0027] The engagement fin 151 of the blade assembly 150 slides in the axial direction in a state of being fitted into the longitudinal groove 142a of the bone fastener 140 and reaches the tip portion of the longitudinal groove 142a configured to enter the rear end portion of the bone engagement portion 141. By configuring the inner peripheral portion of the engagement fin 151 to have a smaller diameter than the inner peripheral surface of the support portion 152, the radial thickness of the engagement fin 151 can be increased more than the thickness of the support portion 152 to further improve the rigidity, and a guiding action due to the engagement with the longitudinal groove 142a can occur, and the guiding function of the engagement fin 151 toward the tip side in the axial direction can be further stabilized. In this case, the longitudinal groove 142a and the inner peripheral portion of the engagement fin 151 can also function as a part of the above-described moving engagement structure.

[0028] On the other hand, a locked portion (locking structure) 152a is formed on the outer peripheral surface of the support portion 152 of the blade assembly 150. By engaging the locked portion 152a with the locking tip 116a of the locking mechanism 110L, the blade assembly 150 can be locked around the axis with respect to the intramedullary nail 110. At this time, by strongly pressing the locking tip 116a against the inner surface of the locked portion 152a, the blade assembly 150 can be not only locked around the axis but also locked (fixed) in the axial direction. In the illustrated example, the locked portion 152a is constituted by a concave groove extending in the axial direction.

[0029] The rear end portion 153 of the blade assembly 150 has an enlarged edge portion having a slightly larger diameter than the outer peripheral surface of the support portion 152, and has an internal thread 153a for connecting to a removal tool (not shown) and an internal peripheral step 153b (see FIG. 5) that engages with the head portion 161a of the compression member 161 (see FIG. 3), such as a compression screw or a lock cap screw, hereinafter described, to pull back (draw in) the bone fixing tool 140 with respect to the blade assembly 150. The increased thickness of the rear end portion 153 ensures reliable contact by the tip portion 139a of the pressing member (pressing nut sleeve 139) described hereinafter, facilitating the pressing operation and enhancing the rigidity of the support portion 152. Further, although the engaging fins 151 of the blade assembly 150 and the support portion 152 are configured to be insertable (passable) into the transverse hole 111, the rear end portion 153 is configured not to be able to pass through the transverse hole 111 due to the outer diameter dimension of the enlarged edge portion. Thereby, in the case where the locking action of the locking mechanism 110L on the locked portion 152a is disengaged due to an operation error or the like and is in a non-locked state, an accident (complication) such as the blade assembly 150 moving axially forward after the operation and the engaging fin 151 penetrating the bone head portion B14 and protruding into the hip joint can be prevented.

[0030] In the blade engaging body 150, the locked portion 152a is formed at a first angular position around the axis (four positions around the axis in the illustrated example) where the engaging fins 151 are formed, and an engaging groove is formed on the inner peripheral surface that engages with the engaging rib 142b at a second angular position around the axis (four positions around the axis in the illustrated example) between the locked portions 152a. As a result, even if the locked portion 152a is formed in a concave groove shape or the engaging groove is formed, the rigidity of the blade engaging body 150 can be ensured without excessively setting the wall thickness (radial thickness) of the cylindrical support portion 152. Further, by providing the engaging rib 142b, a decrease in the rigidity of the shaft portion 142 of the bone fastener 140 is also suppressed.

[0031] In FIGS. 1 and 2, the blade assembly 150 is mounted on the outer peripheral surface of the bone fastener 140, and the engaging fin 151 is fitted into a longitudinal groove 142a provided at the tip portion 142a1 that extends from the shaft portion 142 of the bone fastener 140 into the rear end portion of the bone engaging portion 141. Here, it is only necessary that at least a part of the thickness of the engaging fin 151 is accommodated inside the longitudinal groove 142a. Therefore, although the entire thickness of the engaging fin 151 may be accommodated within the longitudinal groove 142a, the remaining portion of the thickness may protrude to the outer peripheral side of the longitudinal groove 142a. The positions shown in FIGS. 1 and 2 where the blade assembly 150 is in the mounted state on the outer peripheral surface of the bone fastener 140 at this time are referred to as standby positions. In this standby position, since the engaging fin 151 is fitted into the longitudinal groove 142a, even when the blade assembly 150 is mounted, the bone fastener 140 can be introduced into the bone without hindrance by being substantially integrated with the blade assembly 150. More specifically, in the case of the illustrated example, it is possible to insert the bone fastener 140 and the blade assembly 150 arranged in the standby position through the transverse hole 111 of the intramedullary nail 110. In particular, the assembly of the bone fastener 140 and the blade assembly 150 is not only simply insertable through the transverse hole 111, but it is desirable that it is rotatable around the axis. Further, in the standby position, the engaging fin 151 is mounted in a state where at least a part of its thickness is accommodated in the longitudinal groove 142a provided in the rear portion of the bone engaging portion 141 and the shaft portion 142 over the entire axial direction thereof. That is, since the tip portion 151a of the engaging fin 151 is also accommodated within the tip portion 142a1 of the longitudinal groove 142a, the engaging fin 151 does not protrude to the outer peripheral side of the bone engaging portion 141.

[0032] The bone fastener 140 and the blade assembly 150 mounted on this bone fastener 140 constitute an assembly 100S for bone joining. When the blade assembly 150 is arranged in the above-described standby position, this assembly 100S can be inserted through the transverse hole 111 as described above, and moreover, since the engaging fin 151 does not protrude to the outer peripheral side of the bone engaging portion 141, it can be easily introduced into the bone.

[0033] As described above, the tip portion 142a1 of the longitudinal groove 142a has a groove bottom surface that is inclined toward the outer peripheral side toward the tip side in the axial direction. In accordance with this, the tip portion 151a of the engagement fin 151 has an outer peripheral surface that is inclined toward the inner peripheral side toward the tip side in the axial direction so that the thickness is reduced toward the tip side. As a result, in the blade engaging body 150 disposed at the standby position, the tip portion 151a of the engagement fin 151 is less likely to protrude to the outer peripheral side due to the groove bottom surface, so that it is configured to be less likely to engage with the surrounding tissue during introduction into the bone. Further, in the illustrated example, when the blade engaging body 150 is disposed at the standby position, the tip portion 151a of the engagement fin 151 is located on the tip portion 142a1 having the inclined groove bottom surface of the longitudinal groove 142a. Therefore, as soon as the blade engaging body 150 starts to move from the standby position to the functional position, the engagement fin 151 protrudes to the outer peripheral side. Thus, it is possible to shorten the axial movement stroke of the blade engaging body 150 on the bone fixture 140 while ensuring the protruding amount of the engagement fin 151. Furthermore, in the blade engaging body 150 disposed at the standby position, when the bone fixture 140 is introduced to an assumed depth in the bone through the transverse hole 111 of the intramedullary nail 110, the locked portion 152a is disposed at a position shifted to the outer side of the bone or the outside of the body rather than the inside of the transverse hole 111. As a result, when the blade engaging body 150 is disposed at the functional position described later, the locked portion 152a is likely to be disposed at a position corresponding to the locking tip 116a of the locking mechanism 110L.

[0034] It is preferable that the blade engaging body 150 disposed at the standby position mounted on the bone joint device 140 is provided with positioning and holding means for holding the standby position with respect to the bone joint portion 140. As an example of this positioning and holding means, as shown in FIGS. 12, 13, and 16, a holding convex portion 151b is provided on the inner peripheral surface of the tip portion 151a, and the holding convex portion 151b fits into a holding concave portion 142a2 formed on the groove bottom surface of the tip portion 142a1 of the longitudinal groove 142a, so that the blade engaging body 150 is held so as to be less likely to move in the axial direction. The positioning and holding means provided between the bone joint portion 140 and the blade engaging body 150 is not limited to the illustrated example, and any structure may be used as long as it suppresses relative movement in the axial direction by fitting with each other in the radial direction. For example, the relationship between the convex portion and the concave portion may be configured contrary to the illustrated example, and the fitting position may not be the tip portion 151a of the engaging fin 151 as in the illustrated example, but other portions (especially the inner surface thereof) of the engaging fin 151 of the blade engaging body 150 or the support portion 152 (especially the inner peripheral surface thereof) may be fitted with the bone joint device 140 (especially the outer peripheral surface thereof). Further, in the illustrated example, as shown in the arrow portion of FIG. 16, the corner portion on the tip side in the axial direction of the holding convex portion 151b is chamfered, so that the elastic deformation of the engaging fin 151 facilitates the escape of the holding convex portion 151b to the tip side in the axial direction with respect to the holding concave portion 142a2. As a result, as will be described later, the operation of shifting (pressing) to the tip side in the axial direction when moving the blade engaging body 150 from the standby position to the functional position becomes easy.

[0035] The blade engaging body 150 in the mounted state with respect to the bone fastener 140 configured as described above can shift from the standby position (the position retracted to the rear end side in the axial direction) shown in FIGS. 1 and 2 to the functional position (the position advanced to the front end side in the axial direction) shown in FIGS. 3 and 4. In the case of the illustrated example, the shift from this standby position to the functional position is performed while maintaining the mounted state of the blade engaging body 150 with respect to the bone fastener 140, that is, while maintaining the above-described assembly 100S. In the blade engaging body 150 disposed at the functional position, the engaging fin 151 moves from a state in which at least a part in the thickness direction is accommodated in the longitudinal groove 142a formed from the rear portion of the bone engaging portion 141 to the shaft portion 142, and moves toward the front end side in the axial direction. By being guided by the groove bottom surface provided at the tip portion 142a1 of the longitudinal groove 142a and inclined obliquely outward toward the front, the engaging fin 151 projects obliquely outward from the axial direction toward the front end side in an open manner (expanded manner), protruding further to the outer peripheral side than the outer peripheral position of the bone engaging portion 141. The expanded manner of the engaging fin 151 of the blade engaging body 150 disposed at this functional position is shown in FIGS. 9(a) and (b).

[0036] As shown in FIGS. 3 and 4, in the blade engaging body 150 disposed at the above-described functional position, engaging fins 151 protrude around the bone engaging portion 141 of the introduced bone fastener 140, and are inserted into the bone tissue around the bone engaging portion 141, for example, a reticular bone tissue such as cancellous bone, so that the engagement strength between the bone engaging portion 141 of the bone fastener 140 and the bone can be improved. In particular, through the above-described moving engagement structure, it becomes possible to prevent the rotation of the bone tissue around the axis of the bone fastener 140. This effect is further enhanced by providing a plurality (four in the illustrated example) of engaging fins 151. Further, when the blade engaging body 150 is disposed at the above-described functional position, since the engaged portion 152a of the support portion 152 is disposed in the transverse hole 111 of the intramedullary nail 110, by operating the operating member 114 of the locking mechanism 110L, the locking tip 116a of the engaging member 116 can be engaged with the engaged portion 152a, whereby the intramedullary nail 110 and the blade engaging body 150 can be fixed at least around the axis. Then, due to the above-described moving engagement structure, the bone fastener 140 and the blade engaging body 150 can be fixed around the axis with respect to the intramedullary nail 110, so that the bone portion (for example, the bone head B14 shown in FIG. 20) engaged with the bone engaging portion 141 of the bone fastener 140 and the engaging fins 151 of the blade engaging body 150 can be strongly restricted from rotating with respect to the shaft portion B11 of the femur B10. Note that the bone fastener 140 introduced at an appropriate position within the bone is disposed at a position close to the cortical portion of the femoral neck B13 or the bone head B14, so that it can firmly receive the load due to body weight.

[0037] In the present embodiment, in the blade engaging body 150 disposed at the functional position, the base of the engaging fin 151 and the axial front edge of the support portion 152 are disposed in the vicinity of the rear end of the bone engaging portion 141 of the bone fastener 140, and substantially the entire shaft portion 142 of the bone fastener 140 is covered by the cylindrical support portion 152 of the blade engaging body 150, whereby the rigidity of the blade engaging body 150 itself and the mounting rigidity of the blade engaging body 150 with respect to the bone fastener 140 (particularly, the rigidity of the moving engagement structure around the axis) can be improved without hindering the engagement strength between the bone engaging portion 141 and the bone.

[0038] The transition of the blade assembly 150 from the standby position to the functional position can be achieved by pressing the blade assembly 150 axially toward the distal end with respect to the bone fastener 140. The method of this transition is not particularly limited, but a method of axially pressing the rear portion of the blade assembly 150 with a pressing member is preferred. As an example of this method, as shown in FIGS. 10 and 11, there is a method of pressing the blade assembly 150 (the rear end portion 153 thereof) axially toward the distal end from outside the body through the compression nut sleeve 139 as a pressing member. Here, FIG. 11 shows a state in which the T wrench 137 and the central shaft 138 as introduction tools and the compression nut sleeve 139 as a pressing tool, respectively shown in FIG. 19, are connected to the assembly 100S of the bone fastener 140 and the blade assembly 150. Further, FIG. 10 shows an enlarged view of the intramedullary nail 110 and the assembly 100S of the bone fastener 140 and the blade assembly 150 at this time. FIG. 10 is different from the state shown in FIGS. 1 and 2 in that the assembly 100S is connected to the introduction tool and the pressing tool, but in other respects, it is the same as the state shown in FIGS. 1 and 2 when the blade assembly 150 is arranged at the standby position.

[0039] The assembly 100S of the bone connector 140 and the blade assembly 150 is preliminarily connected to an introduction tool comprising a T-shaped groove 137 and a central axis 138 shown in FIG. 19. And in a state of being connected to this introduction tool, a pressing tool comprising a compression nut sleeve 139 is mounted so as to be axially movable with respect to the introduction tool. The assembly 100S of the bone connector 14 and the blade assembly 150 is introduced into the bone through the transverse hole 111 of the intramedullary nail 110 previously inserted into the intramedullary cavity of the femur B10. At this time, it is preferably introduced using the target device 131 of the surgical instrument 130 shown in FIG. 20. The target device 131 is connected by connecting a connection end 131a to the proximal end of the intramedullary nail 110, and by inserting the above-described introduction tool through a guide sleeve 132 attached to the aiming portion 131b, the assembly 100S of the bone connector 140 and the blade assembly 150 is guided into the bone (transverse hole 111). Actually, the introduction operation of the assembly 100S by the introduction tool is carried out by guiding the assembly 100S, the introduction tools 137, 138 and the pressing tool 139 along the previously inserted guide pin 134.

[0040] The connection structure of the introduction tool to the assembly 100S of the bone fastener 140 and the blade assembly 150 is as follows. The rear end portion 143 of the bone fastener 140 is connected to the T-slot 137 through which the central axis 138 shown in FIG. 19 is inserted. Specifically, the front end portion 137a, which is the tool-side engaging portion of the T-slot 137, is fitted in a state of engaging with the rear end portion 143 of the bone fastener 140 in the rotational direction around the axis. A female screw (not shown) formed in the axial hole opening of the rear end portion 143 is screwed onto the male screw 138a provided at the tip of the central axis 138, and the head portion 138b of the central axis 138 is axially engaged with the rear end portion provided with the gripping portion 137b of the T-slot 137, whereby the T-slot 137 and the central axis 138 are connected and fixed to the bone fastener 140. In this way, with the introduction tool connected to the bone fastener 140, the front end portion 139a of the compression nut sleeve 139, which is a pressing tool through which the introduction tool is inserted, is configured to abut against the rear end portion 153 of the blade assembly 150. Thereby, as shown in FIG. 11, the bone fastener 140, the blade assembly 150, the T-slot 137, the central axis 138, and the compression nut sleeve 139 are assembled. FIG. 14(a) shows the assembly structure at this time with the blade assembly 150 removed, and FIG. 14(c) shows the blade assembly 150 in a cross-sectional view. In the illustrated example, a female screw (not shown) formed on the inner peripheral surface of the compression nut sleeve 139 is screwed with the male screw 137c formed on the outer peripheral surface of the T-slot 137, and the compression nut sleeve 139 is configured to be able to be moved little by little in the axial direction with respect to the T-slot 137 by rotating the compression nut sleeve 139.

[0041] In the above assembly structure, as shown in Fig. 14(b), among the T-shaped wrench 137 in which the front end portion 137a is connected to the rear end portion 143 of the bone fastener 140, an annular groove 137f is formed on the outer peripheral surface of the front end side portion disposed inside the blade engaging body 150, and an elastic retaining ring (C-ring) shaped locking ring 137g is fitted in this annular groove 137f. This locking ring 137g is attached so that it can slightly protrude radially outward from the outer peripheral surface of the T-shaped wrench 137 due to its elasticity, and thus axially engages with the female thread 153a formed on the inner peripheral surface of the rear end portion 153 of the blade engaging body 150. However, since this locking ring 137g is elastically deformable, when it receives a strong operating force in the axial direction, it easily sinks into the annular groove 137f, and the axial locking state with the female thread 153a is released. The axial locking structure between this locking ring 137g and the female thread 153a is an example of the above-described positioning and holding means, and in particular, is an example of one of the positioning and holding means formed between the blade engaging body 150 and the introduction tool connected to the bone fastener 140.

[0042] Note that 137e shown in Fig. 14(d) is a stepped portion provided on the T-shaped wrench 137. This stepped portion 137e is formed at a location that coincides with the rear end portion 153 of the blade engaging body 150 when the front end portion 137a is engaged with the rear end portion 153 of the blade engaging body 150 in the standby position in the above assembly structure. When the T-shaped wrench 137 is inserted into the blade engaging body 150 and connected in a state of being rotationally engaged with the rear end portion 143 of the bone fastener 140 inside the blade engaging body 150, the stepped portion 137e coincides with the rear end portion 153 of the blade engaging body 150. Therefore, by screwing the male thread 138a of the central shaft 138 into the female thread of the rear end portion 143 of the bone joint portion 140 in this state, the bone fastener 140 can be reliably connected in a rotatable state. That is, in the present embodiment, the stepped portion 137e of the introduction tool (T-shaped wrench 137) functions as an indicator (mark) indicating a state in which the front end portion 137a is connected to the rear end portion 143 of the bone fastener 140 without any trouble.

[0043] In the above assembly structure, by rotating the gripping portion 137b of the T-wrench 137, the bone engaging portion 141 of the bone fixture 140 can be introduced into the bone in a manner of screwing it in. However, prior to this introduction operation, the piercing operation of the guide pin 134 and the drilling operation with a reamer are performed. When the bone engaging portion 141 reaches an appropriate position within the bone, the positional relationship between the intramedullary nail 110 and the assembly 100S of the bone fixture 140 and the blade assembly 150 becomes the state shown in FIGS. 1 and 2. At this time, for example, in the case of the fracture treatment of the proximal femur shown in FIG. 20, the tip of the bone engaging portion 141 of the bone fixture 140 reaches a position immediately below the cortical portion of the femoral head B14. Note that since the angular posture around the axis of the assembly 100S of the bone fixture 140 and the blade assembly 150 can be known by the structure such as the posture of the gripping portion 137b of the T-wrench 137 and the marks displayed on the surrounding base portion 137d and the like, thereby, the locked portion 152a provided on the support portion 152 of the blade assembly 150 can be set to be disposed at an angular position facing the locking tip 116a of the locking structure 110L disposed in the axial hole of the intramedullary nail 110.

[0044] Thereafter, from the state shown in FIG. 14(c), as shown in FIG. 15(a), the compression nut sleeve 139 (for example, the knurled portion 139c, the rear end portion 139b, and other portions) is operated to move axially forward with respect to the T-wrench 137 (in the case of the illustrated example, the threaded structure between the T-wrench 137 and the compression nut sleeve 139 is rotated). As a result, the tip portion 139a of the compression nut sleeve 139 presses the rear end portion 153 of the blade engaging body 150. Thereby, while remaining attached to the bone fastener 140, the blade engaging body 150 is moved axially forward. At this time, the locked state between the locking ring 137g and the female thread 153a is released, and the axially holding state by the positioning and holding means is also released. Alternatively, instead of this positioning and holding means, or together with this positioning and holding means, when other positioning and holding means such as the positioning and holding means constituted by the fitting state between the aforementioned holding convex portion 151b and the holding concave portion 142a2 are provided, the axially holding state by that positioning and holding means is also released. In this way, the blade engaging body 150 can be shifted from the standby position to the functional position while remaining attached to the bone fastener 140. In the case of the illustrated example, a plurality of positioning and holding means are provided, but it is sufficient if any one of the positioning and holding means is formed.

[0045] In the blade engaging body 150 that has shifted to the functional position as described above, as described above, the engaging fin 151 protrudes to the outer peripheral side of the bone engaging portion 141 and engages within the bone as described above. At this time, as shown in FIGS. 3, 4, and 17, the functional position in the axial direction where the blade engaging body 150 is disposed is set such that there is a gap G between the rear end position of the bone engaging portion 141 and the axial front edge of the support portion 152 that follows in the circumferential direction of the base portion (root portion) of the engaging fin 151. This gap G means that the blade engaging body 150 can actually move axially forward by the amount of the gap G with respect to the bone fastener 140 more than the illustrated functional position.

[0046] The amount of the gap G at the functional position of the blade assembly 150 is preferably configured to be set in advance depending on the structure and movable range of the compression nut sleeve 139 which is a pressing tool. In the case of the illustrated example, scale markings are provided axially on the base 137d near the gripping tool 137b of the T-slot 137, and by reading the position of the rear end portion 139b of the compression nut sleeve 139 with reference to the scale markings, it is possible to confirm how far in front of the maximum axial movement amount of the blade assembly 150 relative to the bone fastener 140 it is arranged. Thereby, after confirming how much of a gap there is in the axial direction of the bone fastener 140 at the fracture site with an X-ray fluoroscope, the compression nut sleeve 139 is moved to a position in front of the maximum movement amount by a distance approximately corresponding to the gap at the fracture site. Thereby, the axial gap G is set between the bone fastener 140 and the blade assembly 150. Incidentally, the above scale markings may be provided at other locations on the introduction tool or the pressing tool. For example, by forming scale markings on the outer peripheral surface of the compression nut sleeve 139 at a location corresponding to the base of the guide sleeve 132 shown in FIG. 20, it is possible to know how much the compression nut sleeve 139 has been pushed in as the blade assembly 150 moves, by checking at what position of the scale markings the base of the guide sleeve 132 is located.

[0047] Thereafter, as shown in FIGS. 3 and 4, the above-described introduction tool and pressing tool are removed, and the compression member 161 is attached to the rear end portion 153 of the blade engaging body 150. The compression member 161 has a head portion 161a that engages inside the rear end portion 153 of the blade engaging body 150, a male screw 161b that projects from the tip of the head portion 161a and engages with a female screw provided at the opening of the shaft hole of the rear end portion 143 of the bone fastener 140, and a fitting projection 161c that projects from the tip of the male screw 161b and fits into the shaft hole. By inserting and screwing the compression member 161 into the rear end portion 143 of the bone fastener 140, as shown in FIG. 5, the corner portion on the tip side of the head portion 161 of the compression member 161 is locked to the inner circumferential step 153b of the blade engaging body 150 described above, and is inserted into the shaft hole of the bone fastener 140. Therefore, when the gap G exists, within the range of the gap G, the bone fastener 140 can be pulled back toward the rear end side in the axial direction with respect to the blade engaging body 150. At this time, when the blade engaging body 150 is fixed in the axial direction by the locking mechanism 110L with respect to the intramedullary nail 110, the bone fastener 140 is pulled backward in the axial direction with respect to the intramedullary nail 110.

[0048] Accordingly, when there is a fracture line between the diaphyseal part B11 having the medullary cavity in which the intramedullary nail 110 is fixed and the bone part (such as the femoral neck part B13 and the femoral head part B14) with which the bone engaging part 141 of the bone fixing device 140 is engaged, and when there is the above-described gap between the fracture parts, the reduction state that collapsed during the introduction of the above-described bone fixing device 140 and the blade assembly 150 can be restored by pulling back the bone part toward the diaphyseal part B11 to eliminate the gap between the fracture parts and reduce the fracture. The maximum value of the pulling-back amount at this time is the amount of the above-described gap G. FIGS. 5, 6, and 18 show the states of the intramedullary nail 110, the bone fixing device 140, and the blade assembly 150 after the restoration of the reduction state by compression using the compression member 161. In the case of the illustrated example, the above-described gap G is almost eliminated as shown by the arrow part in FIG. 18. At this time, if the gap G is set to be completely eliminated, in the assembly of the bone fixing device 140, the blade assembly 150, and the compression member 161, axial force is generated at the screwed part of the female screw of the rear end part 143 of the bone fixing device 140 and the male screw 161b of the compression member 161 via the blade assembly 150, so that loosening of the screw of the compression member 161 can be prevented.

[0049] In this embodiment, when the blade engaging body 150 is disposed at the functional position, the compression member 161 also functions as a positioning and holding means between the bone fixture 140 and the blade engaging body 150. Here, when only considering the mechanical configuration of the assembly 100S and the compression member 161, the compression member 161 acts as a functional component that only prevents the blade engaging body 150 from moving toward the rear end side in the axial direction with respect to the bone fixture 140. However, when the bone fixture 140 and the blade engaging body 150 are respectively engaged directly or indirectly with both bone portions on both sides of the fracture line in the bone B10, as a result of applying an axial compression force to both bone portions described above, the compression member 161 is placed in a state of receiving the reaction force of the compression force between the bone fixture 140 and the blade engaging body 150. For this reason, the compression member 161 becomes a functional component (axial positioning member) that resists the reaction force. As a result, attaching the compression member 161 to the rear end portion 143 of the bone fixture 140 or the rear end portion 153 of the blade engaging body 150 positions and holds the functional position of the blade engaging body 150 with respect to the bone fixture 140 on both the front end side and the rear end side in the axial direction. Therefore, the compression member 161 and the attachment structure of the bone fixture 140 and the blade engaging body 150 thereto can be understood as a positioning and holding means for positioning and holding the functional position of the blade engaging body 150 with respect to the bone fixture 140.

[0050] In the present embodiment described above, an intramedullary nail (fixing device) 110 includes a detachable locking mechanism 110L that is installed on the first bone portion B11 and locks a transverse hole 111 directed toward the second bone portions B13 and B14 and a member inserted through the transverse hole 111 around an axis. In a bone joining system 100 in which a bone joining tool 140 corresponding to the transverse hole 111 and a blade engaging body 150 are attached to form an assembly 100S, between the outer peripheral surface of the bone joining tool 140 and the blade engaging body 150, in a mounted state of the bone joining tool 140 and the blade engaging body 150, movement engaging structures 142a, 142b, 151, and 152 are provided that engage the bone joining tool 140 and the blade engaging body 150 around the axis and allow axial movement between a standby position on the rear end side in the axial direction and a functional position on the front end side in the axial direction of the blade engaging body 150 with respect to the bone joining tool 140. The blade engaging body 151 is configured such that when disposed at the standby position, the engaging fin 151 does not protrude from the bone joining tool 140 in a state that does not prevent introduction into the bone through the transverse hole 111 of the intramedullary nail 110 together with the bone joining tool 140, and when disposed at the functional position, the engaging fin 151 protrudes from the bone joining tool 140. Thereby, when the blade engaging body 151 is disposed at the standby position on the outer peripheral surface of the bone joining tool 140, the assembly 100S of the bone joining tool 140 and the blade engaging body 150 can be introduced into the bone without trouble without any special alignment. In particular, unlike the conventional structure in which a key ring corresponding to the blade engaging body can be inserted only at a specific angular position with respect to the transverse hole of the intramedullary nail, the assembly 100S can be inserted into the transverse hole 111 of the intramedullary nail 110 without trouble. In particular, in the illustrated example, since the assembly 100S is rotatable with respect to the transverse hole 111 and no setting of the angular position is required, the introduction operation through the transverse hole 111 of the assembly 100S is greatly facilitated.

[0051] Thereafter, when the blade engaging body is moved from the standby position to the functional position by an operation, the engaging fins 151 of the blade engaging body 150 protrude from the bone engaging portion 141 of the bone fixture 140 in a mounted state engaged around the axis of the bone fixture 140 and engage with the bone. Therefore, the blade engaging body 151 can be introduced into the bone together with the bone fixture 140 through the transverse hole. After this introduction, by simply moving the blade engaging body 151 from the standby position to the functional position by an operation, the engaging fins 151 protrude to engage with the bone. Moreover, since the bone fixture 140 and the blade engaging body 150 are originally engaged in the rotational direction by the above-described moving engagement structure, if the assembly 100S is locked around the axis by the locking mechanism, it becomes possible to enhance the engaging force with the bone, particularly the rotational resistance around the axis.

[0052] In addition, the assembly 100S composed of the above-described bone fixture 140 and the blade engaging body 150 has a function similar to that of an implant having a structure in which one or a plurality of hooks stored inside are protruded from the opening and engaged in the bone. These examples are described, for example, in International Publication No. WO2015 / 056328 and International Publication No. WO2015 / 059717. However, in these implants, since it is necessary to incorporate a structure for protruding the hook from the opening, there are problems such as the structure becoming complicated, the manufacturing cost increasing, and the operation during surgery becoming complicated. On the other hand, in the present embodiment, since the blade engaging body 150 is mounted on the outer peripheral surface of the bone fixture 140, the structure is simplified, the manufacturing cost can be suppressed, and furthermore, the operation during surgery is also simplified.

[0053] In particular, when in the mounted state with respect to the bone fastener 140, by having positioning and holding means for holding the blade engaging body 150 in the standby position, the blade engaging body is held in the standby position by the positioning and holding means. Therefore, when introducing the bone fastener in the mounted state and the blade engaging body into the bone, the blade engaging body mounted on the outer peripheral surface of the bone fastener may deviate from the standby position due to resistance received during introduction from surrounding tissues, other implants such as intramedullary nails and bone plates, tools, etc. This risk can be reduced. Here, the positioning and holding means may be constituted by an axial engagement structure 142a2, 151b formed between the bone fastener 140 and the blade engaging body 150. In this case, it is desirable that the positioning and holding means be constituted by an engagement structure between an axial step portion 142a2 provided on the outer peripheral surface of the bone fastener 140 and an axial step portion 151b provided on a portion facing the outer peripheral surface of the blade engaging body 150. In particular, it is more desirable that this engagement structure holds the standby position of the blade engaging body 150 on both the front end side and the rear end side in the axial direction. According to this, since the standby position of the blade engaging body 150 can be held on both sides in the axial direction, it becomes possible to hold the blade engaging body 150 in the standby position regardless of the direction of the external force received. Also, when further comprising introduction tools 137, 138 for introducing the bone fastener in the mounted state and the blade engaging body, the positioning and holding means may be formed between the blade engaging body 150 and the introduction tools 137, 138. At this time, it is desirable that the introduction tools 137, 138 be connected to the bone fastener 140 and the engagement structures 153a, 137f, 137g be formed between the blade engaging body 150 and the introduction tools 137, 138.

[0054] Also, in the present embodiment, between the outer peripheral surface of the bone fastener 140 and the blade engaging body 150, in the mounted state, movement engaging structures 142a, 142b, 151, 152 that engage around the axis and allow axial movement between the standby position and the functional position are provided. Thus, the blade engaging body 150 can be moved from the standby position to the functional position while maintaining the mounted state with respect to the bone fastener 140, facilitating the movement operation of the blade engaging body 150. Here, it is desirable that the above-described movement engaging structure be provided between the outer peripheral surface of the shaft portion 142 of the bone joint portion 140 and the support portion 152 of the blade engaging body 150. According to this, since the movement engaging structures 142b, 152 can be formed in a portion other than the engaging fins 151 that protrude due to the movement from the standby position to the functional position, it is easier to ensure the rigidity of the movement engaging structure. At this time, it is more desirable that the movement engaging structures 142b, 152 include a guiding structure that guides the movement of the blade engaging body 150 from the standby position to the functional position. According to this, the movement operation of the blade engaging body 150 from the standby position to the functional position can be further facilitated by the movement engaging structures 142b, 152 having the guiding structure.

[0055] Furthermore, in the present embodiment, it is preferable that a longitudinal groove 142a that fits into the engagement fin 151 be provided on the outer peripheral surface of the bone fastener 140 so as to be movable in the axial direction. Here, the longitudinal groove 142a preferably extends in the axial direction and is a guide groove that guides the engagement fin 151 when the blade engaging body 150 moves from the standby position to the functional position. At this time, the longitudinal groove 142a preferably has a groove bottom portion that inclines toward the outer peripheral side toward the bone engaging portion 141, and it is more desirable that the engagement fin 151 project outwardly from the outer peripheral side of the bone engaging portion 141 when the blade engaging body 150 moves from the standby position to the functional position. According to this, since the engagement fin 151 is guided to the outer peripheral side of the bone engaging portion 141 by the inclination of the groove bottom portion, the engagement fin 151 can be easily and surely projected from the bone fastener 140. Here, in the present embodiment, since the bone fastener 140 and the blade engaging body 150 are fixed around the axis by the moving engagement structure and the engagement fin 151 is always fitted in the longitudinal groove 142a, it is not necessary to configure the longitudinal groove 142a and the engagement fin 151 to be detachable as in the prior art. Therefore, the operation of adjusting the angular position around the axis between the bone fastener 140 and the blade engaging body 150 can be made unnecessary.

[0056] In addition, in the present embodiment, by further providing a compression member 161 that engages both the bone fastener 140 and the blade engaging body 150 from the rear end side in the axial direction and pulls the bone fastener 140 rearward in the axial direction with respect to the blade engaging body 150, the compression member 161 can pull the bone fastener 140 rearward in the axial direction with respect to the blade engaging body 150. Therefore, when a gap occurs in the fracture portion, reduction can be performed by the compression force of the compression member 151. Here, it is preferable that a movement limit is set on the tip side in the axial direction of the blade engaging body 150 in the mounted state with respect to the bone fastener 140. According to this, by moving the blade engaging body 150 to the movement limit with respect to the bone fastener 140, an axial force can be applied to the pulling of the bone fastener 140 with respect to the blade engaging body 150 by the compression member 161, so that the stability of the assembly 100S composed of the bone fastener 140 and the blade engaging body 150 can be improved. Further, when the compression member 161 is constituted by a compression screw, loosening of the screw can be reduced by the above axial force. Here, it is desirable that the above movement limit is constituted by the contact between the tip edge of the support portion 152 continuous with the base of the engaging fin 151 and the rear edge of the bone engaging portion 141.

[0057] Furthermore, in the present embodiment, introduction tools 137 and 138 connected to the rear portion of the bone fastener 140, and a pressing tool 139 that is mounted movably (e.g., coaxially) in the axial direction with respect to the introduction tools 137 and 138 and can press the rear portion of the blade engaging body 150 are provided. The introduction tools 137 and 138 are configured to be able to introduce the bone fastener 140 and the blade engaging body 150 disposed at the standby position into the bone. The pressing tool 139 is preferably configured to be able to move the blade engaging body to the functional position by moving it toward the tip side in the axial direction. At this time, with the above-described movement engagement structure, the blade engaging body 150 can be shifted from the standby position to the functional position simply by pressing it in the axial direction. Therefore, operations such as removing the introduction tool connected to the rear portion of the bone fastener, attaching the blade engaging body to an insertion tool different from the introduction tool, adjusting the angular position of the blade engaging body, and inserting it into the body, which were performed with the conventional structure, become unnecessary, and the shifting operation can be performed extremely easily. That is, in the present embodiment, the assembly 100S of the bone fastener 140 and the blade engaging body 150 can be introduced only by the introduction tools 137 and 138, and the pressing tool 139 pre-mounted on this introduction tool can realize the shifting operation of the blade engaging body 150 from the standby position to the functional position, so that operations such as tool replacement, angular adjustment of the blade engaging body 150 alone, and insertion operation can be made unnecessary.

[0058] In addition, in the present embodiment, an intramedullary nail 110 is further provided, which is inserted into the medullary cavity of the bone and has a transverse hole 111 penetrating in a direction intersecting the axis. The assembly 100S of the bone fixing device 140 and the blade engaging body 150 arranged in the standby position is configured to be introducible into the bone through the transverse hole 111. The intramedullary nail 110 further includes an axial hole 113 communicating with the transverse hole 111, and by having a locking mechanism 110L configured to be detachable inside the axial hole 113 and inside the transverse hole 111 for the assembly 100S, the introduction into the bone through the transverse hole 111 can be completed without performing adjustment work on the assembly 100S. After that, since the assembly 100S inserted into the transverse hole 111 is locked by the locking mechanism 110L, with respect to the intramedullary nail 110 engaged with the diaphysis B11 which is the first bone part, the bone fixing device 140 and the blade engaging body 150 engaged with the neck B13 and the head B14 of the bone which are the second bone parts can be fixed around the axis with extremely simple operations, so that rotation of the fracture part can be reliably prevented.

[0059] In this case, when the blade engaging body 150 is arranged in the functional position at least in the mounted state with respect to the bone fixing device 140, by having a locked structure 152a locked around the axis by the locking mechanism 110L within the range arranged inside the transverse hole 111, unlike the conventional structure, there is no need to provide an opening region in the portion arranged inside the transverse hole 111 of the blade engaging body 150 in order to lock the locking mechanism 110L to the bone fixing device 140. Therefore, the rigidity of the entire blade engaging body 150 can be increased, and as a result, the support rigidity of the engaging fin 151 can also be improved.

[0060] That is, in the aforementioned conventional structure, in order to fix the bone fixing device to the intramedullary nail by a locking mechanism such as a set screw, it is necessary to engage the locking mechanism with the outer peripheral portion of the bone fixing device through the axial hole that opens in the transverse hole of the intramedullary nail. Therefore, the blade engaging body having a plurality of engaging fins must have a large opening area structure for exposing the outer peripheral portion of the bone fixing device in the transverse hole. As a result, it is difficult to ensure the rigidity of the blade engaging body, and there is a problem that it is difficult to improve the engaging force with the bone, such as enhancing the resistance to rotation by the engaging fins. Further, in order to avoid such a situation, it is necessary to provide a key structure that engages with the transverse hole in the blade engaging body as in other conventional structures. As a result, it is necessary to perform an insertion operation after adjusting the angular position of the blade engaging body in advance, or to adjust the angular position of the engaging fins to match the groove structure of the bone fixing device.

[0061] Therefore, in the present embodiment, by providing the blade engaging body 150 with a locked structure 152a that is locked by the locking mechanism 110L within a range that is disposed inside the transverse hole 111 when disposed at the functional position in the mounted state with respect to the bone fixing device 140, it is possible to eliminate the need to provide an opening for exposing the bone fixing device 140 in the said range. As a result, it has become easier to ensure the rigidity of the blade engaging body 150. Further, it has also been possible to avoid the need for an extra angular position adjustment operation as in other conventional structures.

[0062] Note that the bone fixation system of the present invention is not limited to being configured as an intramedullary fixation system including an intramedullary nail, a bone fixing device, and a blade engaging body as in the above-described embodiment of the illustrated example. It can be applied to various bone fixation systems including a bone fixing device and a blade engaging body. For example, instead of the above intramedullary nail, it can be applied to various systems configured to additionally use a blade engaging body with respect to a bone fixing device in a CHS (Compression Hip Screw) system further including a barrel plate as a fixing device.

[0063] In addition, in the above-described embodiment, a compression screw is illustrated as the compression member 161. However, the compression member according to the present invention is not limited to the above compression screw, and a member having various lock structures such as a fastener structure and a latch structure for applying (maintaining) a compression amount in a state of being engaged in the axial direction with respect to the (rear end portion of the) bone fastener can be used. Also, from this perspective, the compression member and the structure of the rear end portion of the bone fastener or blade engaging body that engages with the compression member can be grasped as positioning and holding means for axially positioning the functional position of the blade engaging body.

Explanation of Reference Numerals

[0064] 100... Bone fixation system, 100S... Assembly, 110... Intramedullary nail, 110L... Locking mechanism, 111, 112... Transverse holes, 113... Axial hole, 113a... Opening, 114... Operating member (operating screw), 115... Holding member (holding nut), 116... Engaging member (engaging pin), 116a... Locking tip, 130... Surgical instrument, 131... Target device, 131a... Connection end portion, 131b... Aiming portion, 132, 133... Guide sleeves, 134, 135... Guide pins, 136... Holder, 137... T wrench, 137a... Tip portion (tool-side engaging portion), 137b... Gripping portion, 137c... Male screw, 137d... Base portion, 137e... Step portion, 137f... Annular groove, 137g... Locking ring, 138... Central axis, 138a... Male screw, 138b... Head portion, 139... Compression nut sleeve, 139a... Tip portion, 139b... Rear end portion, 139c... Knurled portion, 139d... Rear end portion, 140... Bone fastener (lag screw), 141... Bone engaging portion, 142... Shaft portion, 142a... Longitudinal groove, 142a1... Tip portion, 142a2... Holding recess, 142b... Engaging rib, 143... Rear end portion, 150... Blade engaging body, 151... Engaging fin, 151a... Tip portion, 151b... Holding projection, 152... Support portion, 152a... Engaged portion (concave groove), 153... Rear end portion, 153a... Female screw, 153b... Inner peripheral step, 161... Compression member, 161a... Head portion, 161b... Male screw, 161c... Fitting projection

Claims

1. A fixture provided on a first bone portion and having a detachable locking mechanism for locking a transverse hole provided toward a second bone portion and a member inserted through the transverse hole around an axis, and introduced through the transverse hole toward the second bone portion, a bone engaging tool having a bone engaging portion provided on the tip side in the axial direction and engaging with the second bone portion and a shaft portion provided on the rear end side in the axial direction, an engaging fin provided on the tip side in the axial direction, and a support portion provided on the rear end side in the axial direction for integrally supporting the engaging fin, and a blade engaging body configured to be attachable to the outer peripheral surface of the bone engaging tool. Between the outer peripheral surface of the bone engaging tool and the blade engaging body, in a state where the bone engaging tool and the blade engaging body are attached, there is provided a moving engagement structure that engages the bone engaging tool and the blade engaging body around the axis and allows movement in the axial direction between a standby position on the rear end side in the axial direction and a functional position on the front end side in the axial direction of the blade engaging body with respect to the bone engaging tool. The blade engaging body is configured such that when disposed in the standby position in the attached state, the engaging fin does not protrude from the bone engaging tool in a state that does not prevent introduction into the bone through the transverse hole together with the bone engaging tool. Also, the blade engaging body is configured such that when disposed in the functional position in the attached state, the engaging fin protrudes from the bone engaging tool. Bone joining system.

2. Having positioning and holding means for holding the blade engaging body in the standby position. The bone joining system according to Claim 1.

3. The positioning and holding means is constituted by the axial engagement structure formed between the bone engaging tool and the blade engaging body. The bone joining system according to Claim 2.

4. Further comprising an introduction tool for introducing the bone engaging tool and the blade engaging body in the attached state, The positioning and holding means is constituted by the axial engagement structure formed between the introduction tool connected to the bone engaging tool and the blade engaging body. The bone joining system according to Claim 2.

5. The positioning and holding means holds the blade engaging body on both the front end side and the rear end side in the axial direction. The bone joining system according to Claim 2.

6. The moving engagement structure is provided between the outer peripheral surface and the support portion. The bone joining system according to any one of claims 1-5.

7. The movement engagement structure includes a guiding structure for guiding the movement of the blade engaging body from the standby position to the functional position. The bone joining system according to claim 6.

8. On the outer peripheral surface of the bone joining tool, there is provided a longitudinal groove which is a guiding groove that fits into the engaging fin so as to be movable in the axial direction, extends in the axial direction, and guides the engaging fin when the blade engaging body moves from the standby position to the functional position. The bone joining system according to any one of claims 1-5.

9. The longitudinal groove has a groove bottom portion that inclines toward the outer peripheral side toward the bone engaging portion, and projects the engaging fin toward the outer peripheral side of the bone engaging portion when the blade engaging body moves from the standby position to the functional position. The bone joining system according to claim 8.

10. The bone joining tool and the blade engaging body are both engaged from the rear end side in the axial direction, and further include a compression member capable of pulling the bone joining tool rearward in the axial direction with respect to the blade engaging body. The bone joining system according to any one of claims 1-5.

11. It includes an introducing tool connected to the rear portion of the bone joining tool, and a pressing tool that is movably mounted in the axial direction with respect to the introducing tool and can press the rear portion of the blade engaging body. The introducing tool is configured to be able to introduce the bone joining tool and the blade engaging body arranged in the standby position into the bone. The pressing tool is configured to be able to move the blade engaging body to the functional position by moving it to the front end side in the axial direction. The bone joining system according to any one of claims 1-5.

12. The fixing tool is an intramedullary nail that is inserted into the medullary cavity of the bone and has the transverse hole penetrating in a direction intersecting the axis, and the assembly of the bone joining tool and the blade engaging body is configured to be lockable by the locking mechanism. The bone joining system according to any one of claims 1-5.

13. The intramedullary nail further includes an axial hole communicating with the transverse hole. The locking mechanism is housed inside the axial hole and is configured to be able to lock the assembly inside the transverse hole. The bone joining system according to claim 12.

14. The blade engaging body has a locked structure that is locked by the locking mechanism at least when it is arranged in the functional position in the mounted state with respect to the bone joining tool. The bone fixation system according to claim 12.

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