JP5961774B1 - Osteosynthesis - Google Patents

Abstract

An osteosynthesis device 1 as an example of an osteosynthesis device to which the present invention is applied includes an intramedullary nail 2, a set screw 3, and an end cap 4. Moreover, the lag screw 5 and the sub pin 6 are inserted in the intramedullary nail 2 as an engaging member engaged with a bone fragment. The end cap 4 has a protruding portion 27, a tapered portion 28, a thread groove portion 29, and a head portion 30. The protruding portion 27 has a diameter that can be inserted into the through hole 24 of the set screw 3, and the tip thereof is formed in a hemispherical shape. This hemispherical portion comes into contact with the cylindrical outer peripheral surface of the sub-pin 6 and fixes the sub-pin.

Description

  The present invention relates to a bone connector. More specifically, the present invention relates to a bone connector that is excellent in handling at the time of use and can sufficiently suppress the rotation of bone fragments at a treatment site.

  2. Description of the Related Art Conventionally, bone joint devices that combine intramedullary nails and lag screws have been used in the field of fracture treatment. The intramedullary nail is inserted along the longitudinal direction of the bone to be treated, and is used particularly for the treatment of femoral fractures and the like.

  A bone joint that combines an intramedullary nail and a lag screw is subject to a load due to daily activities after treatment, etc., and may rotate due to the rotational force applied to the bone piece and the lag screw engaged with the bone piece. . As a result, cases have been reported in which bone fragments are separated again or the adhesion of fracture sites is delayed.

  As a proposal for avoiding such a symptom, a subpin attached to the intramedullary nail in a direction substantially parallel to the lag screw is used in combination. The sub-pin is a sharp rod-like member, and the pointed tip enters the cancellous material in the bone to make it difficult for the bone fragment and the lag screw to rotate.

  There is also a structure in which a groove is formed along the longitudinal direction on the outer peripheral surface of the lag screw and rotation is suppressed by using a control member fitted to the groove. The control member has a protrusion that fits into the groove of the lag screw, and is disposed inside the intramedullary nail to fit into the groove of the lag screw.

  By fitting the protrusion of the control member and the groove of the lag screw, the lag screw is restricted from rotating around the longitudinal direction as the central axis.

  The degree of fixing by this control member is adjusted using a separate adjustment member. For example, there is a configuration in which an adjustment member is attached to the inside of the intramedullary nail and above the control member so as to contact the control member. The penetration depth of the adjusting member into the intramedullary nail is adjusted, and the fixing degree of the control member with respect to the lag screw is varied depending on the penetration depth.

  However, in the structure using the sub-pin as described above, the fixing degree by the control member of the lag screw can be adjusted, but the sub-pin is not fixed. Therefore, a structure for controlling the fixing degree of the sub-pin has not been adopted.

  If the fixing of the sub-pin is insufficient, the sub-pin inserted into the bone rotates and slides back and forth in the longitudinal direction. In particular, a case has been reported in which the subpin moves to the distal direction side and breaks through the bone head.

  Under such circumstances, there exists a bone joint device that attempts to simultaneously control a plurality of engaging members that engage with bone fragments such as a lag screw and a sub-pin. For example, a bone joint device described in Patent Document 1 has been proposed. ing.

  As shown in FIGS. 12A and 12B, the osteosynthesis device 100 described in Patent Document 1 includes an intramedullary nail body 101, a control member 102, and a cap 103. A plurality of holes are provided in the intramedullary nail body 101, and the main lag screw 104 and the auxiliary lag screw 105 are inserted therein.

  The control member 102 has a protruding portion 106 at the tip, and the protruding portion 106 is fitted into the groove 107 of the main lag screw 104 so that rotation is suppressed. The control member 102 is pushed downward by the movement of the cap 103 attached to the inner peripheral surface of the intramedullary nail body 101 with a screw structure.

  The control member 102 has an overhanging portion 108, and the region of the inner peripheral surface of the intramedullary nail body 101 facing this is a recess 109 whose diameter decreases downward. As the cap 103 moves, the control member 102 is pushed downward while the overhanging portion 108 and the depression 109 generate contact drag. Then, the interval between the cracks 110 of the control member 102 becomes narrower.

  When the interval between the cracks 110 becomes narrow, the insertion passage 111 through which the sub lag screw 105 is inserted becomes narrow, and the inner wall surface of the insertion passage 111 comes into contact with the sub lag screw 105. Finally, the contact pressure of the insertion passage 111 regulates the sliding and rotation of the auxiliary lag screw 105. That is, in the bone fastener 100, the control member 102 fixes the main lag screw 104 and the sub lag screw 105 simultaneously.

JP 2009-153939 A

  However, in the bone joint device described in Patent Document 1, the fixing degree of both the main lag screw and the auxiliary lag screw is adjusted by a control member and a cap for adjusting the control member. If the control member is loosened, both engaging members may rotate or slide.

  Further, the control member is affected by both the load applied to the main lag screw and the load applied to the sub lag screw. That is, due to the patient's operation after the operation, a load is applied to both the main lag screw and the auxiliary lag screw, and vibrations from both engagement members are transmitted to the control member, so that the control member is more likely to loosen. ing.

  Further, the fixing of the auxiliary lag screw is gradually generated from the generation of the contact drag between the overhang portion and the depression accompanying the pressing of the control member to the narrowing of the crack of the control member. Since the movement of the control member does not directly fix the sub-pin, it is expected that the fixing of the sub-pin is insufficient.

  Further, in the conventional bone joint, a member called an end cap that closes the through hole of the intramedullary nail is attached to the upper side of the control member. Depending on the direction in which the bone fastener is handled, the control member may fall out from the inside of the intramedullary nail before the end cap is attached.

  Furthermore, a conventional bone joint has a structure in which a control member is attached to the inner peripheral surface of an intramedullary nail with a screw structure, and the control member is rotated to adjust the advance and retreat of the intramedullary nail in the longitudinal direction. The control member is accommodated in the intramedullary nail and used for use. However, the control member may enter deep inside the intramedullary nail and reach the end of the screw structure due to the vibration of transportation before use.

  At this time, an operation of pulling up the control member to a predetermined height position using a dedicated driver for rotating the control member is generated, which increases labor during the operation. Separately, a silicon stopper member is attached and removed before use. However, it is necessary to prepare the stopper member, and it takes time and effort to remove the stopper member.

  In addition, depending on the method of use, the control member is completely tightened in order to control the movement of the lag screw in the rotational direction and allow the movement to the rear end side in the longitudinal direction to allow “fixing that allows sliding”. In some cases, the position is set back by a quarter of a turn in the loosening direction. At this time, it is important that the control member does not advance and retract more than necessary in the through-hole of the intramedullary nail and keeps a slightly loosened position.

  The present invention was devised in view of the above points, and provides an osteosynthesis device that is excellent in handling at the time of use and that can sufficiently suppress rotation of a bone fragment at a treatment site. It is the purpose.

  In order to achieve the above object, the osteosynthesis device of the present invention is a first tubular body in which a first through hole is formed, and a first pin hole communicated with the first through hole. A second pin hole located on the opposite side of the first pin hole of the first cylindrical body and coaxially and communicating with the first through hole, and below the first pin hole. A first screw hole located substantially parallel to the first pin hole and communicating with the first through hole; and a position opposite to and coaxial with the first screw hole of the first cylindrical body. And an intramedullary nail in which a second screw hole communicating with the first through hole is formed, and a second cylindrical body that can be accommodated inside the intramedullary nail and has a second through hole formed therein. A third pin hole communicating with the second through-hole, and a second pin located opposite to and coaxial with the third pin hole of the second cylindrical body. A first control member formed with a fourth pin hole communicating with the through-hole, and a fitting formed on one end side of the first control member and projecting in one end direction of the first control member A first fixing portion that is located on the other end side of the first control member and that can fix the first control member to the intramedullary nail; The first through hole is closed at the end opposite to the first screw hole and the second screw hole as viewed from the first pin hole and the second pin hole of the inner nail. A second control member, a second fixing member provided on the second control member and capable of fixing the second control member to the intramedullary nail, and protruding from the second control member A protrusion that can be inserted into the second through-hole from the other end of the first control member, and the first fixing portion on the inner peripheral surface of the intramedullary nail is fixed. The first fixing portion has a gap between the first inner peripheral region to be fixed and the second inner peripheral region to which the second fixing portion of the inner peripheral surface of the intramedullary nail is fixed. And the second fixing portion is fixed to the inner peripheral surface of the intramedullary nail with a screw structure, and the region between the first inner peripheral region and the second inner peripheral region of the intramedullary nail is It is a 1st hollow part formed so that an internal diameter may be larger than the internal diameter of the said 1st inner peripheral area | region and the 2nd inner peripheral area | region, It is a ring shape which has the cut | interruption which can surround a part of said protrusion part. And a retaining ring portion that is positioned with a predetermined clearance between the first control member and fills the first recess portion and fits into the first recess portion. Yes.

  Here, when the intramedullary nail is the first cylindrical body in which the first through-hole is formed, it becomes possible to put another member inside the first through-hole. That is, the first control member and the second control member can be accommodated.

  The intramedullary nail is connected to the first pin hole communicating with the first through hole and the first pin hole of the first cylindrical body opposite to the first pin hole and coaxially. By forming the second pin hole, the engaging member to the bone fragment can be inserted through the first pin hole and the second pin hole. The engaging member here includes, for example, known sub-pins and sub-lag screws.

  The intramedullary nail includes a first screw hole located substantially parallel to the first pin hole below the first pin hole and communicating with the first through hole, and a first cylindrical body first. The main screw is inserted into the first screw hole and the second screw hole by forming a second screw hole which is located on the opposite side of the screw hole and coaxially and communicates with the first through hole. It becomes possible.

  Further, since the first control member can be accommodated inside the intramedullary nail, the first control member can be arranged inside the intramedullary nail.

  Further, the first control member is a second cylindrical body that can be accommodated inside the intramedullary nail and has a second through-hole formed therein, so that the first control member is arranged inside the intramedullary nail, Furthermore, it becomes possible to put another member inside the first control member. That is, the protruding portion can be inserted.

  The first control member has a third pin hole communicating with the second through hole, and a second through hole located on the opposite side and coaxial with the third pin hole of the second cylindrical body. By forming the fourth pin hole communicating with the third pin hole, the engaging member to the bone fragment can be inserted into the third pin hole and the fourth pin hole. The engaging member here includes, for example, known sub-pins and sub-lag screws. The third pin hole corresponds to the first pin hole of the first control member, and the fourth pin hole corresponds to the second pin hole of the first control member. In addition, the linear positions in the third pin hole and the fourth pin hole are those in which a known sub-pin or the like can be inserted straight and the sub-pin or the like can be disposed in a substantially parallel positional relationship with the lag screw. If it is enough.

  Further, the first control member is positioned on one end side of the first control member, and the first control member is inserted into the first screw hole of the intramedullary nail by a fitting convex portion that protrudes toward the one end of the first control member. And it can be set as the fixing tool of the member inserted in a 2nd screw hole. That is, for example, when the main lag screw is inserted into the first screw hole and the second screw hole, the fitting convex portion is fitted into the groove formed in the longitudinal direction on the outer peripheral surface of the main lag screw. The first control member regulates the rotational movement of the main lag screw.

  In addition, the first control member can be fixed to the intramedullary nail by a first fixing portion that is located on the other end side of the first control member and can fix the first control member to the intramedullary nail. .

  In addition, the first nail is located on the inner side of the intramedullary nail and at the end opposite to the first screw hole and the second screw hole as viewed from the first pin hole and the second pin hole of the intramedullary nail. The second control member that closes the through hole can prevent foreign matter from entering the first through hole of the intramedullary nail while disposing the first control member inside the intramedullary nail.

  Further, the second control member can be fixed to the intramedullary nail by a second fixing portion provided on the second control member and capable of fixing the second control member to the intramedullary nail.

  In addition, a first inner peripheral region to which the first fixing portion of the inner peripheral surface of the intramedullary nail is fixed, and a second inner peripheral region to which the second fixing portion of the inner peripheral surface of the intramedullary nail is fixed The first control member is not excessively fixed to the intramedullary nail, and the first control member is less likely to be unremovable. For example, when the intramedullary nail is made of titanium, if the length of the fixing part such as a screw structure is long, the fixing member may be too bite and cannot be separated. By setting a discontinuous fixing portion with a gap between the first inner peripheral region and the second inner peripheral region, it is possible to prevent excessive entrapment.

  The first fixing portion and the second fixing portion are fixed to the inner peripheral surface of the intramedullary nail with a screw structure, so that the first control member and the second control member are rotated and the intramedullary nail is rotated. Can be fixed to. In addition, the rotation operation in the screw structure at this time can be performed by, for example, a combination of a polygonal driver and a fitting hole fitted therein.

  In addition, the area between the first inner peripheral area and the second inner peripheral area of the intramedullary nail is a first inner diameter formed larger than the inner diameter of the first inner peripheral area and the second inner peripheral area. And is a ring shape having a slit that can surround a part of the projecting portion, and is located with a predetermined clearance between the first control member, and fills the first recess. By providing the retaining ring portion that fits into the recessed portion, it is possible to prevent the first control member from falling off via the retaining ring portion. That is, when the first control member and the retaining ring portion are accommodated in the intramedullary nail and the second control member is not attached, the first control member rotates and comes out of the first through hole. Even if it moves in the direction, it will come into contact with the retaining ring portion located in the first recess and cannot move beyond that. In addition, it is possible to sufficiently tighten the second control member with the screw structure in the direction of the first control member while preventing the first control member from falling off at the retaining ring portion. That is, since the thread groove on the inner peripheral surface of the intramedullary nail is temporarily interrupted at the position of the first recess portion, and the retaining ring portion is disposed in the recess portion, the retaining ring portion is disposed on the continuous thread groove. Then, the screwing of the second control member, which is insufficient, can be sufficiently performed. As a result, the fixing of the second control member to the intramedullary nail, the fixing of the sub-pin by the second control member and the protrusion, and the prevention of the loosening of the first control member are ensured.

  The first fixing portion has an outer diameter that is substantially the same as the inner diameter of the first inner peripheral region, and is a substantially donut with a cross section viewed from the short direction side of the first control member. And the first control member has a first fitting part that can be installed in the first control member, and the first control member has a second fitting part that can be installed in the first fitting part, When the outer diameter of at least a part of the first fitting portion is larger than the inner diameter of the corresponding region of the second fitting portion, the first fitting portion and the first fitting portion The tightening margin is generated between the two fitting portions. As a result, when the first fixing portion rotates with respect to the first inner peripheral region, that is, the first fixing portion and the first control member advance and retract with respect to the first through hole of the intramedullary nail. In this case, a frictional resistance force is generated between the first fitting portion and the second fitting portion, and the first fixing portion is difficult to rotate with respect to the intramedullary nail with a weak force such as vibration. . That is, the positions of the first fixing portion and the first control member in the through-hole of the intramedullary nail are easily held. Thereby, it becomes a structure in which excessive insertion and loosening of the first control member are unlikely to occur.

  Further, when the protruding portion has a length that reaches the region between the tip end of the second through hole and the third pin hole and the fourth pin hole, the second control member is It is possible to provide a fixture for a member inserted into the pin hole to the fourth pin hole. That is, for example, when the sub pin is inserted into the first pin hole to the fourth pin hole, the projecting portion is brought into contact with the outer peripheral surface of the sub pin and fixed with the pressure, and the second control member slides the sub pin. It regulates the movement and rotation.

  Further, when the protruding portion has a length where the tip is located on the other end side of the first control member from the region sandwiched between the third pin hole and the fourth pin hole of the second through hole. Can make the member constituted by the second control member and the protruding portion compact. That is, for example, it can be used when a bone is joined with an intramedullary nail and a lag screw without using a sub-pin together.

  Further, when the first fixing portion is rotatably mounted with respect to the first control member, the first pin hole and the second pin hole of the intramedullary nail and the first control member It is easy to align the positions of the third pin hole and the fourth pin hole. That is, for example, when the first fixing portion is fitted and rotated with a dedicated driver, the first control member moves forward and backward to the first through hole of the intramedullary nail without rotating. The first control member can be fixed at a predetermined position of the intramedullary nail while the positions of the pin hole and the fourth pin hole are hardly changed.

  The first fixing portion is rotatably mounted with respect to the first control member, and the first control member includes an inner peripheral surface thereof, the first fixing portion, the third pin hole, and the fourth pin. When a thread groove is formed in a region between the holes, only the first control member can be advanced and retracted with respect to the intramedullary nail. That is, for example, even when the first fixing portion and the first control member are separated and cannot be used as they are, a dedicated screwdriver is fitted into the screw groove of the first control member to It can be taken out from the inner nail. As a result, the fixed state of the lag screw by the first control member can be released.

  In addition, six grooves having a substantially hexagonal cross section when viewed from the short direction side of the first control member along the longitudinal direction of the first control member are formed on the inner peripheral surface of the first fixing portion. In such a case, the rotation operation of the first fixed portion can be performed more reliably, and usability can be improved. Here, a dedicated hexagonal screwdriver that fits into the six grooves is used. For example, the driver is less likely to slip with respect to the first fixed portion than in a case where the screwdriver is fitted on two surfaces. It will be a thing.

  The first fixing portion has a first fitting portion whose outer diameter is substantially the same as the inner diameter of the first inner peripheral region, and which can be housed in the first control member. A slit penetrating from the inner peripheral surface of the two through holes to the outer peripheral surface of the first fixing portion, and a second recess positioned from the inner peripheral surface of the second through hole toward the outer peripheral surface of the first fixing portion. And the first control member has a second fitting portion that can house the first fitting portion, and the protruding portion can be fitted into the second recess and the protruding portion of the protruding portion. In the case of having a tapered portion whose diameter decreases in the direction, the first control member can be made difficult to loosen. That is, the taper portion of the protruding portion comes into contact with the second recess portion of the first fixing portion, so that the slit portion of the first fixing portion spreads, and the contact pressure is uniformly applied to the first fixing portion. It will be a thing. As a result, the pressure of contact between the first fixing portion and the inner peripheral surface of the intramedullary nail increases, and the first control member can be made difficult to loosen. Further, the lower the second control member is fixed, the more difficult it is to loosen the first control member.

  In addition, the first fixed portion has a first fitting portion whose outer diameter is formed larger than the inner diameter of the first inner peripheral region and has elasticity, and can be installed in the first control member. When a slit penetrating from the inner peripheral surface of the second through hole to the outer peripheral surface of the first fixing portion is formed, when the first fixing portion and the first control member are inserted into the intramedullary nail A resistance force is generated between the first fixing portion and the first inner peripheral region, and the positions of the first fixing portion and the first control member in the through-hole of the intramedullary nail are easily maintained. More specifically, the outer diameter of the first fixing portion is larger than the first inner peripheral region before being inserted into the intramedullary nail, but when inserted into the intramedullary nail, due to the size of the diameter, The distance between the slit portions is reduced by contact with the first inner peripheral region, and the outer diameter of the first fixing portion is reduced. As a result, an urging force is generated in the first fixing portion to return to the original outer diameter due to elasticity, and the first fixing portion pushes the first inner peripheral region of the intramedullary nail and Become. In addition, the magnitude | size of the resistance force produced between a 1st fixing | fixed part and a 1st inner peripheral area | region is the screw structure to the intramedullary nail of the 1st fixing | fixed part and 1st control member by a separate attachment tool. It is not a big force that prevents insertion and removal by For example, what is necessary is just to produce the resistance force of the grade which the 1st fixing | fixed part does not rotate arbitrarily with respect to slight external forces, such as an external vibration.

  From the above viewpoint, for example, before inserting the first fixing portion and the first control member into the intramedullary nail, a process of expanding the slit of the first fixing portion with a dedicated jig is performed. A method in which the outer diameter of the fixing portion is slightly larger than that of the first inner peripheral region can be employed.

  In addition, when the outer diameter of at least a part of the first fitting portion is larger than the inner diameter of the corresponding region of the second fitting portion, the first fitting portion And a second fitting part are tightened. As a result, when the first fixing portion rotates with respect to the first inner peripheral region, that is, the first fixing portion and the first control member advance and retract with respect to the first through hole of the intramedullary nail. In this case, a frictional resistance force is generated between the first fitting portion and the second fitting portion, and the first fixing portion is difficult to rotate with respect to the intramedullary nail with a weak force such as vibration. . That is, the positions of the first fixing portion and the first control member in the through-hole of the intramedullary nail are easily held. Thereby, it becomes a structure in which excessive insertion and loosening of the first control member are unlikely to occur.

  Further, when the protruding portion has a length that reaches the region sandwiched between the third pin hole and the fourth pin hole of the second through hole, the second control member is moved to the first control member. It is possible to provide a fixture for a member inserted into the pin hole to the fourth pin hole. That is, for example, when the sub pin is inserted into the first pin hole to the fourth pin hole, the projecting portion is brought into contact with the outer peripheral surface of the sub pin and fixed with the pressure, and the second control member slides the sub pin. It regulates the movement and rotation.

  Further, when the protrusion has a length located at the other end side of the first control member from the region sandwiched between the third pin hole and the fourth pin hole of the second through hole. Can make the member constituted by the second control member and the protruding portion compact. That is, for example, it can be used when a bone is joined with an intramedullary nail and a lag screw without using a sub-pin together.

  The osteosynthesis device according to the present invention is excellent in handleability at the time of use, and can sufficiently suppress the rotation of the bone fragment at the treatment site.

FIG. 2 is a side sectional view and a partially enlarged view of the bone joint device according to the first embodiment of the present invention. It is the schematic front view (b) which shows the schematic front view (a) of an end cap, and the structure of another end cap. It is the schematic sectional view (a) of the intramedullary nail and the schematic view (b) which looked at the intramedullary nail from the near side of the insertion direction of a lag screw. It is a schematic sectional drawing which shows the shape of the other intramedullary nail. It is the schematic (a) of a subpin, and the schematic (b) of a lag screw. Sectional view seen from the side of the set screw, side schematic view of the set screw and washer (a), schematic view of the washer (b), schematic view of the head side of the set screw (c), and body side of the set screw A schematic diagram (d) is shown. It is sectional drawing (a) of a trunk | drum, sectional drawing (b) of a head, and schematic (c) of a head. It is the schematic which shows the other shape of a washer. Sectional view and side schematic view of set screw and washer (a), schematic view of washer (b), schematic view of head side of set screw in the second embodiment of the present invention (C) and the schematic view (d) of the fuselage side of the set screw are shown. It is sectional drawing (a) of a trunk | drum, sectional drawing (b) of a head, and schematic (c) of a head. It is the schematic which shows the structure of the nail | claw part in a head and CC line. It is the figure (a) which showed the cross-sectional shape of the conventional bone joint tool, and the figure (b) which showed the cross-sectional shape of the state which looked at the figure from the side surface.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings for understanding of the present invention.
FIG. 1 is a side sectional view and a partially enlarged view of a bone joint device according to an embodiment of the present invention. In addition, the structure of this invention is not limited to the content shown below, It can change suitably.

  As shown in FIG. 1, an osteosynthesis device 1, which is an example of an osteosynthesis device to which the present invention is applied, includes an intramedullary nail 2, a set screw 3, and an end cap 4. Moreover, the lag screw 5 and the sub pin 6 are inserted in the intramedullary nail 2 as an engaging member engaged with a bone fragment. Each of the osteosynthesis tools 1 is formed of a metal member that can be used in a surgical operation.

  The intramedullary nail 2 is a member that connects the bone fragments so that the bone fragments are not displaced and fused or separated before the fractured site is healed. Moreover, it is a member holding engagement members, such as the lag screw 5, in bone.

  In the intramedullary nail 2, a pin hole 7 and a pin hole 8, a screw hole 9 and a screw hole 10 are formed, and a lag screw 5 and a sub pin 6 are inserted respectively. The lag screw 5 bites into the sponge in the bone to be treated (not shown) to generate a resistance force in the anterior-posterior direction, thereby preventing the head from falling off and preventing the rotation.

  A male screw 11 is formed on the outer peripheral surface of the tip of the lag screw 5, and this male screw 11 becomes a portion that bites into the intraosseous sponge. A screw groove 12 is formed on the outer peripheral surface of the body portion of the lag screw 5 along the longitudinal direction.

  The screw groove 12 is a portion that fits into a protruding piece 13 at the tip of the set screw 3 to be described later. A plurality of screw grooves 12 are formed at regular intervals on the circumference of the outer peripheral surface of the body portion of the lag screw 5.

  The sub-pin 6 is a sharp rod body, and the tip portion easily enters the sponge in the bone to be treated, and is located in the bone without forming a large hole in the bone. It is positioned substantially parallel to the lag screw 5 in the bone, and suppresses the rotation of the bone head.

  The sub pin 6 is formed shorter than the lag screw 5. Moreover, the trunk | drum part is formed in the column shape.

  At the lower end of the intramedullary nail 2, a lateral stop hole (not shown) is formed, and a lateral stop screw is inserted at the lower end position to fix the intramedullary nail 2 in the bone.

  As shown in FIG. 1, a through hole 14 is formed in the axial center of the intramedullary nail 2. A part of the lag screw 5 and the sub pin 6 described above is located in the through hole 14. A set screw 3, a washer 16 and an end cap 4 are attached inside the through hole 14.

  The set screw 3 is a member that is fixed to the inner peripheral surface of the intramedullary nail 2 and suppresses the rotation of the lag screw 5. A protruding piece 13 is formed at the tip of the set screw 3 and is fitted to the screw groove 12 of the lag screw 5.

  Further, the set screw 3 is formed with a pin hole 18 and a pin hole 19, and is located on the same straight line as the pin hole 7 and the pin hole 8 of the intramedullary nail 2 described above, and is a portion into which the sub pin 6 is inserted. ing.

  The set screw 3 has a projecting portion 20 having a large diameter, and a thread groove 21 is formed on the outer peripheral surface thereof. The screw groove 21 is fitted to the screw groove 22 on the inner peripheral surface of the intramedullary nail 2, and the set screw 3 is fixed to the intramedullary nail 2 with a screw structure. Further, the overhang portion 20 is fitted to the step 23 of the intramedullary nail 2.

  A through hole 24 is formed in the center of the set screw 3 in the longitudinal direction. The through hole 24 is a part into which a part of the end cap 4 is inserted.

  A slit substantially parallel to the through hole 24 is formed on the inner peripheral surface of the overhang portion 20 of the set screw 3. The shape of the slit will be described later.

  Here, the shapes of the pin hole 18 and the pin hole 19 of the set screw 3 are not particularly limited, and it is sufficient if the sub pin 6 can be inserted straight and is positioned substantially parallel to the lag screw 5. is there.

  A washer 16 is disposed above the set screw 3. The washer 16 serves as a member that prevents the set screw 3 from falling out of the through hole 14. The washer 16 is a ring-shaped member having a cut, and has a diameter capable of surrounding a part of the end cap 4.

  The washer 16 is disposed in a recess 25 on the inner peripheral surface of the intramedullary nail 2. The depression 25 is formed slightly larger than the washer 16, and the washer 16 is fitted with a margin.

  On the inner peripheral surface of the intramedullary nail 2, a recess 25 is positioned between a screw groove 22 for fixing the set screw 3 and a screw groove 26 for fixing an end cap, which will be described later. That is, on the inner peripheral surface of the intramedullary nail 2, screw grooves are formed discontinuously.

  An end cap 4 is attached above the set screw 3 and the washer 16. The end cap 4 is a member that is fixed to the inner peripheral surface of the intramedullary nail 2 and closes the through hole 14. Further, the protruding portion 27 of the end cap 4 is a portion for fixing the sub-pin 6 inserted into the intramedullary nail 2.

  The end cap 4 has a protruding portion 27, a tapered portion 28, a thread groove portion 29, and a head portion 30. The protruding portion 27 has a diameter that can be inserted into the through hole 24 of the set screw 3, and the tip thereof is formed in a hemispherical shape. This hemispherical portion comes into contact with the cylindrical outer peripheral surface of the sub-pin 6 and fixes the sub-pin 6.

  The screw groove portion 29 has a screw groove formed on the outer peripheral surface thereof, and is fitted to the screw groove 26 on the inner peripheral surface of the intramedullary nail 2, and the end cap 4 is fixed to the intramedullary nail 2 with a screw structure. Further, the head 30 is formed with a driver hole on the inner side, and becomes a portion where the driver is fitted when the end cap 4 is attached. A hole that fits with the driver is also formed on the inner periphery of the overhang portion 20 of the set screw 3.

  In the screw groove 22 and the screw groove 26 of the intramedullary nail 2, the screw groove 22 is formed longer than the screw groove 26. More specifically, the screw groove 22 has a length of 5.8 mm and the screw groove 26 has a length of 4 mm.

  Here, the tip of the protruding portion 27 of the end cap 4 is not necessarily formed in a hemispherical shape. For example, when a screw groove similar to a lag screw is formed on the outer peripheral surface of the sub-pin, the tip of the protruding portion 27 of the end cap 4 can be a protruding piece that fits into the screw groove.

  Further, the screw groove 22 and the screw groove 26 of the intramedullary nail 2 do not necessarily need to be formed longer than the screw groove 26. Further, the length of the screw groove 22 is not limited to 5.8 mm, and the length of the screw groove 26 is not limited to 4 mm. However, it is preferable that the screw groove 22 is formed longer than the screw groove 26 in the screw groove 22 and the screw groove 26 of the intramedullary nail 2 because the fixing degree of the set screw can be increased.

  Each structural member of the above-described bone connecting device 1 will be described with reference to the drawings.

  FIG. 2: is a schematic front view (a) of an end cap, and a schematic front view (b) which shows the structure of another end cap.

  As described above, the end cap 4 includes the protruding portion 27, the tapered portion 28, the screw groove portion 29, and the head portion 30. The area of the thread groove 29 has the largest diameter, and is fixed to the inner peripheral surface of the intramedullary nail 2 at this position and closes the through hole 14.

  An end cap 31 as shown in FIG. 2B may be used. The end cap 31 is formed with a short protrusion 32 and is attached to the intramedullary nail 2 when the sub-pin is not used together or when the sub-pin is not fixed. The structure of the bone fastener using the end cap 31 shown in FIG. 2B will be described later.

  FIG. 3 is a schematic cross-sectional view (a) of the intramedullary nail and a schematic view (b) of the intramedullary nail viewed from the front side in the insertion direction of the lag screw. FIG. 4 is a schematic cross-sectional view showing the shape of another intramedullary nail.

  As shown in FIG. 3 (a), the intramedullary nail 2 has a through hole 14 formed in the longitudinal direction, and holes for insertion of the lag screw 5 and the sub pin 6 are formed in communication therewith. In addition, a lateral stop hole 33 and a lateral stop hole 34 are formed at the lower end of the intramedullary nail 2, and a lateral stop screw is inserted.

  Further, a screw groove 22 for fixing the set screw 3 and a screw groove 26 for fixing the end cap are formed on the inner peripheral surface of the intramedullary nail 2.

  As shown in FIG. 3B, the pin hole 7 and the pin hole 8 for inserting the sub-pin, and the screw hole 9 and the screw hole 10 for inserting the lag screw have a shape in a range in which the sub-pin and the lag screw can be inserted. It has become a thing.

  The intramedullary nail 41 shown in FIG. 4 has a shape in which the lower side is bent about 4 ° with respect to the central axis on the upper side. More specifically, it may be difficult to insert an intramedullary nail straight along the central axis of the femur, which may cause a new fracture. Therefore, the above-described shape is employed so that the intramedullary nail can be inserted from the top of the greater trochanter of the femur rather than on the central axis of the femur. The set screw 3 and the end cap 4 described above can also be used for such an intramedullary nail 41.

  FIG. 5 shows a schematic diagram (a) of the sub-pin and a schematic diagram (b) of the lag screw.

  As shown in FIG. 5 (a), the sub-pin 6 is a sharp rod-like body, and a hole used for insertion into the intramedullary nail is formed at the opposite end. Moreover, as shown in FIG.5 (b), the lag screw 5 has the external thread 11 formed in the outer peripheral surface of the front-end | tip. A screw groove 12 is formed on the outer peripheral surface. 5A and 5B are diagrams in which each engagement member is viewed from the end opposite to the insertion direction.

  FIG. 6 is a cross-sectional view of the set screw viewed from the side, a schematic side view of the set screw and washer (a), a schematic view of the washer (b), a schematic view of the head side of the set screw (c), and a set. A schematic diagram (d) of the body side of the screw is shown.

  As is clear from FIGS. 6A to 6D, the set screw 3 includes a head portion 35 and a body portion 36. The head portion 35 has a fitting piece 37, and the fitting piece 37 is attached to the fitting groove 38 of the body portion 36 so as not to be separated with respect to a certain force. The head portion 35 is attached to the body portion 36 so as to be rotatable. That is, although the separation in the longitudinal direction is restricted by the fitting piece 37 and the fitting groove 38, rotation about the longitudinal direction is possible.

  Since the head portion 35 is rotatable with respect to the body portion 36, when the set screw 3 is inserted into the through hole 14 of the intramedullary nail 2, the positions of the pin hole 18 and the pin hole 19 are changed. Instead, only the head 35 can be rotated and screwed to the inner peripheral surface of the intramedullary nail 2.

  Further, as is clear from FIG. 6C, the head 35 is formed with a slit 39 and a slit 40. The slit 39 is obtained by partially cutting the head 35 from the inner peripheral surface side to the outer peripheral surface side of the head 35. The slit 40 is narrower than the slit 39 and is formed so as to penetrate from the inner peripheral surface of the head 35 to the outer peripheral surface.

  Further, the outer diameter of the head portion 35 is processed so as to change before and after the head portion 35 and the body portion 36 are integrated. Specifically, the slit 40 is slightly expanded to increase the outer diameter of the head 35.

  First, before the head portion 35 and the body portion 36 are integrated, the outer diameter of the head portion 35 is substantially the same as that of the screw groove 22 of the intramedullary nail 2. That is, the head 35 is rotated with almost no resistance by rotating the head 35 with a dedicated mounting tool, and the outer diameter of the set screw 3 can change the position on the inner peripheral surface of the through hole 14. ing.

  The head 35 is press-fitted into the body portion 36 with a dedicated tool, and the fitting piece 37 is fitted into the fitting groove 38. After that, a wedge-shaped exclusive tool is inserted into the slit 40 and the slit 40 is slightly expanded. After machining, the slit 40 is expanded with the tool removed, and the outer diameter of the head 35 is increased accordingly.

  After processing, the size of the outer diameter of the head 35 is slightly larger than the size of the inner peripheral surface at the position of the screw groove 22 of the intramedullary nail 2. Since the head portion 35 is formed of an elastic metal, when the external force acts in the direction in which the slit distance of the slit 40 is shortened, that is, in the direction in which the outer diameter of the head portion 35 is reduced, the original outer diameter An urging force is generated to return to the size of.

  Since the size of the outer diameter of the head 35 is slightly larger than the size of the inner peripheral surface at the position of the screw groove 22 of the intramedullary nail 2, the set screw 3 is inserted into the through hole 14 of the intramedullary nail 2. When inserting, the above-mentioned urging force is generated. The urging force acts as a force in the direction in which the head portion 35 pushes the screw groove 22, and becomes a resistance force generated between the head portion 35 and the inner peripheral surface of the intramedullary nail 2. As a result, the head 35 can be made difficult to rotate after the set screw 3 is inserted into the intramedullary nail 2. That is, the position of the set screw 3 on the inner peripheral surface of the intramedullary nail 2 is easily maintained.

  A more detailed structure will be described with reference to FIGS. 7 (a), the relationship between the inner diameter φDA at the position 55 in the fitting groove 38 of the body portion 36 and the outer diameter φDB at the position 56 of the head 35 shown in FIG. The frictional resistance between the body 35 and the body portion 36 is different. Since the frictional resistance between the head 35 and the torso 36 is increased, the head 35 is difficult to rotate, and as a result, the position of the set screw 3 on the inner peripheral surface of the intramedullary nail 2 is easily maintained. It will be a thing.

  As described above, by increasing the outer diameter φDB at the position 56, the frictional resistance between the head portion 35 and the body portion 36 can be increased. For example, as shown in FIGS. 7B and 7C, the fitting piece 37 of the head portion 35 has four claw portions 57, but the number and thickness of the claw portions 57 (symbol t1). The elasticity of the claw portion 57 is increased by adjusting the length (symbol h1). By increasing the elasticity of the claw portion 57, the outer diameter φDB of the portion of the head 35 that contacts the body portion 36 becomes larger, and the frictional resistance can be increased. The adjustment of the claw portion will be described later.

  In the first embodiment of the present invention, both the structure of φDA> φDB and the structure of φDA <φDB can be adopted as the relationship between φDA and φDB. From the point of increasing the frictional resistance, A structure of φDA <φDB is preferably adopted.

  Further, the concave portions 58 of the fitting groove 38 of the body portion 36 and the tip shapes of the claw portions 57 of the head portion 35 are shaped so as to easily advance only in the direction in which the claw portion 57 is housed in the fitting groove 38. . In other words, the movement of the claw portion 57 in the direction in which the claw portion 57 is pulled out from the concave portion 58, that is, the direction in which the head portion 35 is pulled out from the body portion 36 is restricted by the catch of the concave portion 58 and the claw portion 57. Thereby, the fitting state of the head 35 and the trunk | drum 36 will be hold | maintained.

  As shown in FIG. 6B, the washer 16 has a cut. This cut is provided so that the washer advances along the thread lead angle of the spiral of the screw structure portion on the inner peripheral surface of the intramedullary nail 2.

  FIG. 8A and FIG. 8B show other shapes of washers that can be used in the present invention. In addition to the washer 16 shown in FIG. 6B, a washer 59 having a substantially circular outer shape and a washer 60 having a substantially flat shape near the cut can be used.

  The specific function in the state which inserted the lag screw and the sub pin in the bone joining tool demonstrated so far is demonstrated.

  First, two types of fixing modes for the lag screw will be described. There are two types of fixing of the lag screw: “static fixing” and “fixing that allows sliding”. Both are common in that the rotation of the lag screw is suppressed, but two different fixation modes are used properly depending on the fracture case.

  “Static fixation” is to fix both the movement of the lag screw in the turning direction and the movement toward the rear end side in the longitudinal direction called sliding.

  “Fixing that allows sliding” means that the movement of the lag screw in the rotational direction is controlled and the movement toward the rear end side in the longitudinal direction is allowed.

  In fixing a lag screw with a normal set screw, after tightening the set screw until it becomes non-rotatable in the screw structure, in order to allow the lag screw to move in the longitudinal direction, the set screw is loosened by a quarter. Rotate back and “fixed to allow sliding”. By loosening, a slight clearance is generated between the tip of the set screw and the screw groove of the lag screw, and the rotation of the lag screw is restricted, but the movement in the longitudinal direction is allowed.

  If the set screw is tightened until it becomes non-rotatable due to the screw structure, the movement of the lag screw in the rotating direction and sliding are controlled, and the lag screw becomes “static fixation” which is firmly fixed.

  When “fixing that allows sliding” is performed, the lag screw engaged with the head of the bone moves to fill the gap between the fractures and promote bone fusion. Therefore, this fixing is also an important fixing mode.

  Thus, it is desirable that both “static fixation” and “fixing that allows sliding” can be performed in a bone joint that uses a lag screw. However, since “fixing that allows sliding” involves an operation of loosening the set screw, an external force or the like may act to loosen the set screw so that the rotation of the lag screw cannot be regulated.

  In the first embodiment of the present invention, with the structure of the set screw 3, the slit 40 is slightly widened to increase the outer diameter of the head 35, and the elastic force of the head 35 is inserted into the intramedullary nail 2. By using this, the position of the set screw on the inner peripheral surface of the intramedullary nail 2 can be easily maintained. In addition, since a frictional force is generated against the rotation of the head 35 between the head 35 and the body portion 36 by adopting a structure having a relationship of φDA <φDB, the inner peripheral surface of the intramedullary nail 2 The position of the set screw in is easy to hold. That is, it is easy to hold the position where the set screw is returned by a quarter of a turn in the direction of loosening, which is in a “fixed state that allows sliding”.

  Further, the end cap 4 can be fixed by the screw structure because the washer 16 is fitted in the recess 25 with a sufficient margin. Therefore, the fixing force of the sub pin is secured.

  Here, as another embodiment of the bone joint device to which the present invention is applied, a structure in which loosening of the set screw 3 is suppressed by an end cap 31 as shown in FIG. In this case, the rotation of the set screw is suppressed by the end cap when the sub pin is not used or the sub pin is not fixed. Further, the regulation of the rotation of the lag screw is the same as that of the first embodiment.

  Specifically, the end cap 31 is inserted into the inner peripheral surface of the head portion 35 of the set screw 3, and the insertion stops in the middle of the tapered portion 66 of the end cap 31. At this time, the tapered portion 66 bites into the slit 39 of the head portion 35. When the taper portion 66 bites into the slit 39, a force is applied in the direction in which the outer diameter of the head 35 expands. However, the presence of the slit 40 increases the diameter of the head 35 and prevents the set screw 3 from being loosened. Can be. That is, the rotation of the set screw 3 with respect to the intramedullary nail 2 is suppressed.

  Next, a second embodiment of the present invention will be described. In the following embodiments of the present invention, members similar to those described above will be described using the same reference numerals.

  In the second embodiment of the present invention, the structure of the set screw is different from that of the first embodiment described above. In more detail, the structure of the head part and the trunk | drum part which comprise a set screw differs from 1st Embodiment. Hereinafter, the structure will be described.

  The osteosynthesis device according to the second embodiment of the present invention includes an intramedullary nail 2, a set screw 42, and an end cap 4. Moreover, the lag screw 5 and the sub pin 6 are inserted in the intramedullary nail 2 as an engaging member engaged with a bone fragment.

  In the intramedullary nail 2, a pin hole 7 and a pin hole 8, a screw hole 9 and a screw hole 10 are formed, and a lag screw 5 and a sub pin 6 are inserted respectively.

  A male screw 11 is formed on the outer peripheral surface of the tip of the lag screw 5, and this male screw 11 becomes a portion that bites into the intraosseous sponge. A screw groove 12 is formed on the outer peripheral surface of the body portion of the lag screw 5 along the longitudinal direction.

  The screw groove 12 is a portion that fits into a protruding piece 43 at the tip of a set screw 42 described later. A plurality of screw grooves 12 are formed at regular intervals on the circumference of the outer peripheral surface of the body portion of the lag screw 5.

  The sub-pin 6 is a sharp rod body, and the tip portion easily enters the sponge in the bone to be treated, and is located in the bone without forming a large hole in the bone. It is positioned substantially parallel to the lag screw 5 in the bone, and suppresses the rotation of the bone head.

  The sub pin 6 is formed shorter than the lag screw 5. Moreover, the trunk | drum part is formed in the column shape.

  At the lower end of the intramedullary nail 2, a lateral stop hole (not shown) is formed, and a lateral stop screw is inserted at the lower end position to fix the intramedullary nail 2 in the bone.

  A through hole 14 is formed in the axial center of the intramedullary nail 2. A part of the lag screw 5 and the sub pin 6 described above is located in the through hole 14. A set screw 42, a washer 16, and an end cap 4 are attached inside the through hole 14.

  The end cap 4 is attached above the set screw 42 and the washer 16. The end cap 4 is a member that is fixed to the inner peripheral surface of the intramedullary nail 2 and closes the through hole 14. Further, the protruding portion 27 of the end cap 4 is a portion for fixing the sub-pin 6 inserted into the intramedullary nail 2.

  The end cap 4 has a protruding portion 27, a tapered portion 28, a thread groove portion 29, and a head portion 30. The protruding portion 27 has a diameter that can be inserted into the through hole 24 of the set screw 3, and the tip thereof is formed in a hemispherical shape. This hemispherical portion comes into contact with the cylindrical outer peripheral surface of the sub-pin 6 and fixes the sub-pin 6.

  The screw groove portion 29 has a screw groove formed on the outer peripheral surface thereof, and is fitted to the screw groove 26 on the inner peripheral surface of the intramedullary nail 2, and the end cap 4 is fixed to the intramedullary nail 2 with a screw structure. Further, the head 30 is formed with a driver hole on the inner side, and becomes a portion where the driver is fitted when the end cap 4 is attached.

  In the screw groove 22 and the screw groove 26 of the intramedullary nail 2, the screw groove 22 is formed longer than the screw groove 26. More specifically, the screw groove 22 has a length of 5.8 mm and the screw groove 26 has a length of 4 mm.

  Here, the tip of the protruding portion 27 of the end cap 4 is not necessarily formed in a hemispherical shape. For example, when a screw groove similar to a lag screw is formed on the outer peripheral surface of the sub-pin, the tip of the protruding portion 27 of the end cap 4 can be a protruding piece that fits into the screw groove.

  Further, the end cap 4 as shown in FIG. 2A is not necessarily used. For example, an end cap 31 as shown in FIG. 2B may be used. The end cap 31 is formed with a short protrusion 32 and is attached to the intramedullary nail 2 when the sub-pin is not used together or when the sub-pin is not fixed.

  Further, the screw groove 22 and the screw groove 26 of the intramedullary nail 2 do not necessarily need to be formed longer than the screw groove 26. Further, the length of the screw groove 22 is not limited to 5.8 mm, and the length of the screw groove 26 is not limited to 4 mm. However, it is preferable that the screw groove 22 is formed longer than the screw groove 26 in the screw groove 22 and the screw groove 26 of the intramedullary nail 2 because the fixing degree of the set screw can be increased.

The structure of the set screw 42 will be described with reference to FIG.
FIG. 9 is a cross-sectional view seen from the side of a set screw according to the second embodiment of the present invention, a schematic side view of the set screw and washer (a), a schematic view of the washer (b), and a head of the set screw. The schematic diagram (c) of the side and the schematic diagram (d) of the fuselage side of the set screw are shown.

  As shown in FIGS. 9A to 9D, the set screw 42 includes a head portion 44 and a body portion 45. The head 44 has a fitting piece 46, and the fitting piece 46 is attached to the fitting groove 47 of the body portion 45 so as not to be separated with respect to a certain force. The head 44 is attached to the body 45 so as to be rotatable. That is, the separation in the longitudinal direction is restricted by the fitting piece 46 and the fitting groove 47, but rotation about the longitudinal direction is possible. 9A is a cross-sectional view, and the lower view is a schematic view.

  Since the head portion 44 is rotatable with respect to the body portion 45, the positions of the pin hole 48 and the pin hole 49 described later are changed when the set screw 42 is inserted into the through hole 14 of the intramedullary nail 2. Without doing so, only the head 44 can be rotated and screwed to the inner peripheral surface of the intramedullary nail 2.

  The set screw 42 is a member that is fixed to the inner peripheral surface of the intramedullary nail 2 and suppresses the rotation of the lag screw 5. A protruding piece 43 is formed at the tip of the set screw 42 and is fitted to the screw groove 12 of the lag screw 5.

  Further, the set screw 42 is formed with a pin hole 48 and a pin hole 49, which are located on the same straight line as the pin hole 7 and the pin hole 8 of the intramedullary nail 2 described above and into which the sub pin 6 is inserted. ing.

  Here, the set screw 42 is not necessarily formed of the head portion 44 and the body portion 45, and the head portion 44 does not have to be attached to the body portion 45 so as to be rotatable. For example, a structure in which the head portion and the trunk portion are integrated without being separated may be employed. However, as described above, the set screw 42 is attached to a desired position without changing the positions of the pin hole 48 and the pin hole 49, and there is no need to align the pin holes. The body portion 45 is preferably configured such that the head portion 44 is rotatably attached to the body portion 45.

  Further, the shapes of the pin hole 48 and the pin hole 49 of the set screw 42 are not particularly limited, and it is sufficient if the sub pin 6 can be inserted straight and is positioned substantially parallel to the lag screw 5. .

  The set screw 42 has a projecting portion 50 having a large diameter, and a thread groove 51 is formed on the outer peripheral surface thereof. The screw groove 51 is fitted to the screw groove 22 on the inner peripheral surface of the intramedullary nail 2, and the set screw 42 is fixed to the intramedullary nail 2 by a screw structure. Further, the overhanging portion 50 is fitted to the step 23 of the intramedullary nail 2.

  A through hole 52 is formed at the center of the set screw 42 in the longitudinal direction. The through hole 52 is a portion into which a part of the end cap 4 is inserted.

  Further, a part of the through hole 52 of the body part 45 is tapped so that a groove part 53 is provided. The groove 53 is a place that can be fitted with a dedicated driver, and when a large external force acts on the head 44 and the body 45 of the set screw 42 and the head 44 and the body 45 are separated, The body part 45 can be removed from the inside of the intramedullary nail 2.

  That is, the fixed state of the lag screw 5 by the set screw 42 can be released. A groove 54 is also formed on the inner peripheral surface of the head 44, and this groove 54 is used during normal use. That is, rotation of the set screw 42 in which the head portion 44 and the body portion 45 are integrated with respect to the intramedullary nail 2 is performed by fitting and rotation of the groove portion 54 and the dedicated driver.

  As shown in the lower figure of FIG. 9A, the washer 16 is disposed above the set screw 42. The washer 16 is a member that prevents the set screw 42 from falling off the through hole 14. As shown in FIG. 9B, the washer 16 is a ring-shaped member having a cut, and is formed to have a diameter that can partially surround the end cap 4.

  Further, the washer 16 is disposed in a recess 25 on the inner peripheral surface of the intramedullary nail 2 (see FIG. 1). The depression 25 is formed slightly larger than the washer 16, and the washer 16 is fitted with a margin.

  On the inner peripheral surface of the intramedullary nail 2, a recess 25 is located between the screw groove 22 for fixing the set screw 42 and the screw groove 26 for fixing the end cap. That is, on the inner peripheral surface of the intramedullary nail 2, screw grooves are formed discontinuously.

  Moreover, as shown in FIG.9 (c), the head 44 is formed in the substantially donut shape by the cross sectional view of the transversal direction. That is, unlike the head portion 35 of the first embodiment described above, the head portion 44 is not formed with slits 39 and slits 40 and has a continuous shape.

  A more detailed structure will be described with reference to FIGS. 10 (a) to 10 (c) and FIG. The size of the inner diameter φDA at the position 61 in the fitting groove 47 of the body 45 shown in FIG. 10A and the outer diameter φDB at the position 62 of the head 44 shown in FIG. 10B is φDA <φDB. It is formed to become. As described above, by increasing the outer diameter φDB, the frictional resistance between the head portion 44 and the body portion 45 is increased, and the head portion 44 can be made difficult to rotate. As a result, the position of the set screw 42 on the inner peripheral surface of the intramedullary nail 2 can be easily maintained.

  The set screw 42 is different from the set screw 3 described above in the structure of the claw portion 63 of the head 44. First, the head 44 of the set screw 42 has six claw portions 63. Further, the thickness (reference symbol t2) of the claw portion 63 is formed thinner than the thickness (reference symbol t1) of the claw portion 57 described above. Further, the length of the claw portion 63 (symbol h2) is longer than the length of the claw portion 57 (symbol h1) described above.

  That is, the claw part 63 has a longer structure than the claw part 57, with an increased number of claws and a reduced thickness. Thereby, the elasticity of the claw part 63 further increases, and the frictional resistance between the head part 44 and the body part 45 can be increased. Further, since the elastic force is improved, the claw portion 63 is unlikely to sag when the head portion 44 and the body portion 45 are integrated, that is, when the claw portion 63 is press-fitted into the fitting groove 47. be able to.

  Further, the concave portions 64 of the fitting groove 47 of the body portion 45 and the tip shapes of the claw portions 63 of the head portion 44 are shaped so as to easily advance and advance only in the direction in which the claw portion 63 is housed in the fitting groove 47. . In other words, the movement of the claw part 63 in the direction in which the claw part 63 is pulled out from the concave part 64, that is, the direction in which the head part 44 comes out of the body part 45 is restricted by the catch of the concave part 64 and the claw part 63. Thereby, the fitting state of the head 44 and the trunk | drum 45 will be hold | maintained.

  In FIG. 11, the diagram on the left side is a schematic diagram of the head 44, and the diagram on the right side is a cross-sectional view taken along line CC. The twelve corner portions 65 of the claw 63 of the head 44 shown in the right side of FIG. 11 are chamfered. Thereby, it has the structure which reduces the sliding galling in the contact location of the trunk | drum 45 and the nail | claw part 63. FIG.

  The groove portion 54 of the head portion 44 has a substantially hexagonal shape in cross section, and is formed in the longitudinal direction along the through hole 52 of the head portion 44. This part is a part that fits with a dedicated hexagon driver, and is a part that causes the set screw 42 to rotate.

  Here, it is not always necessary that the groove 54 has a substantially hexagonal cross section, and it is sufficient if the set screw 42 can be rotated. However, it is preferable that the groove portion 54 is composed of six grooves having a substantially hexagonal cross section because the set screw can be more reliably rotated with less difficulty in sliding with the driver.

  FIG. 9D shows the structure of the body portion 45. As described above, the groove portion 53 is formed in the body portion 45. The present invention can also employ the structure of the second embodiment as described above.

  As described above, in the second embodiment of the present invention, a frictional resistance force is more easily generated between the head and the body of the set screw, and the set on the inner peripheral surface of the intramedullary nail is performed. The position of the screw is easier to hold. In addition, in the state where the "fixing that allows sliding" set screw is returned by a quarter of a turn, the position of the set screw is more easily held.

  As described above, the osteosynthesis device of the present invention is excellent in handleability at the time of use, and can sufficiently suppress the rotation of the bone fragment at the treatment site.

DESCRIPTION OF SYMBOLS 1 Bone joint tool 2 Intramedullary nail 3 Set screw 4 End cap 5 Lag screw 6 Sub pin 7 Pin hole 8 Pin hole 9 Screw hole 10 Screw hole 11 Male screw 12 Screw groove 13 Projection piece 14 Through hole 16 Washer 18 Pin hole 19 Pin Hole 20 Overhang portion 21 Screw groove 22 Screw groove 23 Step 24 Through hole 25 Depression 26 Screw groove 27 Projection portion 28 Taper portion 29 Screw groove portion 30 Head portion 31 End cap 32 Projection portion 33 Side stop hole 34 Side stop hole 35 Head portion 36 body part 37 fitting piece 38 fitting groove 39 slit 40 slit 41 intramedullary nail 42 set screw 43 protruding piece 44 head 45 body part 46 fitting piece 47 fitting groove 48 pin hole 49 pin hole 50 overhanging part 51 Screw groove 52 Through-hole 53 Groove part 54 Groove part 55 Position 56 Position 57 Claw part 58 concave portion 59 washer 60 washer 61 position 62 position 63 claw portion 64 concave portion 65 corner 66 taper portion

Claims (11)

A first cylindrical body having a first through hole, a first pin hole communicating with the first through hole, and the first pin hole of the first cylindrical body. A second pin hole located on the opposite side and coaxially and communicating with the first through hole, and below the first pin hole and positioned substantially parallel to the first pin hole and the first through hole. A first screw hole that communicates with the hole and a second screw hole that communicates with the first through hole and is located on the opposite side of the first cylindrical body and coaxially with the first screw hole are formed. An intramedullary nail,
A second cylindrical body that can be accommodated inside the intramedullary nail and has a second through hole, a third pin hole that communicates with the second through hole, and the second cylinder A first control member having a fourth pin hole formed on the opposite side of the third pin hole of the rod-like body and coaxially and communicating with the second through hole;
A fitting projection formed on one end side of the first control member and projecting in the one end direction of the first control member;
A first fixing portion located on the other end side of the first control member and capable of fixing the first control member to the intramedullary nail;
It is located inside the intramedullary nail and at the end opposite to the first screw hole and the second screw hole as viewed from the first pin hole and the second pin hole of the intramedullary nail. A second control member for closing the first through hole;
A second fixing portion provided on the second control member and capable of fixing the second control member to the intramedullary nail;
A protrusion that protrudes from the second control member and can be inserted into the second through-hole from the other end of the first control member;
A first inner peripheral region to which the first fixing portion of the inner peripheral surface of the intramedullary nail is fixed, and a second inner portion to which the second fixing portion of the inner peripheral surface of the intramedullary nail is fixed. With a gap between the surrounding area,
The first fixing portion and the second fixing portion are fixed to the inner peripheral surface of the intramedullary nail with a screw structure,
A region between the first inner peripheral region and the second inner peripheral region of the intramedullary nail is formed so that an inner diameter thereof is larger than inner diameters of the first inner peripheral region and the second inner peripheral region. A first indentation,
It has a ring shape having a cut that can surround a part of the protruding portion, and is located with a predetermined clearance between the first control member, and the first depression is filled to the same extent. A bone joint having a retaining ring portion that fits into the hollow portion of 1. The first fixed portion has an outer diameter that is substantially the same as the inner diameter of the first inner peripheral region, and the cross section viewed from the short direction side of the first control member is substantially continuous. A donut-shaped and having a first fitting portion that can be installed in the first control member;
The first control member has a second fitting portion that can house the first fitting portion,
The osteosynthesis tool according to claim 1, wherein an outer diameter of at least a part of the first fitting portion is formed larger than an inner diameter of a corresponding region of the second fitting portion. 3. The bone according to claim 1, wherein the protrusion has a length so that a tip thereof reaches a region sandwiched between the third pin hole and the fourth pin hole of the second through hole. Joiner. The protrusion has a length at which the tip is positioned on the other end side of the first control member from a region sandwiched between the third pin hole and the fourth pin hole of the second through hole. The osteosynthesis device according to claim 1 or 2. The first fixing portion is rotatably mounted with respect to the first control member,
The first control member has a thread groove formed in an inner peripheral surface thereof and a region between the first fixing portion and the third pin hole and the fourth pin hole. The bone joint device according to claim 2, claim 3 or claim 4. The first fixing portion has six grooves having a substantially hexagonal cross section as viewed from the short direction side of the first control member along the longitudinal direction of the first control member on the inner peripheral surface thereof. The osteosynthesis tool according to claim 1, claim 2, claim 3, claim 4 or claim 5. The first fixed portion has a first fitting portion whose outer diameter is substantially the same as the inner diameter of the first inner peripheral region, and can be installed in the first control member. A slit penetrating from the inner peripheral surface of the second through hole to the outer peripheral surface of the first fixing portion, and positioned from the inner peripheral surface of the second through hole toward the outer peripheral surface of the first fixing portion. A second depression is formed,
The first control member has a second fitting portion that can house the first fitting portion,
The bone connector according to claim 1, wherein the protrusion includes a tapered portion that can be fitted into the second depression and has a diameter that decreases in a protrusion direction of the protrusion. The first fixing portion has a first fitting portion that has an outer diameter larger than an inner diameter of the first inner peripheral region and has elasticity, and can be fitted in the first control member. A slit penetrating from the inner peripheral surface of the second through hole to the outer peripheral surface of the first fixing portion, and from the inner peripheral surface of the second through hole toward the outer peripheral surface of the first fixing portion. A second indentation located is formed,
The first control member has a second fitting portion that can house the first fitting portion,
The bone connector according to claim 1, wherein the protrusion includes a tapered portion that can be fitted into the second depression and has a diameter that decreases in a protrusion direction of the protrusion. The magnitude | size of the outer diameter of at least one part of the said 1st fitting part was formed more largely than the magnitude | size of the internal diameter of the area | region corresponding to a said 2nd fitting part. Bone joint. The projecting portion has a length such that a tip thereof reaches a region sandwiched between the third pin hole and the fourth pin hole of the second through hole. The bone joint device according to 1. The protrusion has a length at which the tip is positioned on the other end side of the first control member from a region sandwiched between the third pin hole and the fourth pin hole of the second through hole. The bone joint device according to claim 7, claim 8 or claim 9.

Images