JP7237683B2 - rod inserter - Google Patents

Description

The present disclosure relates to rod inserters. Specifically, it relates to rod inserters for holding spinal fixation rods.

Conventionally, various rod inserters for holding spinal fixation rods have been proposed (see Patent Documents 1 and 2, for example).

Japanese Patent Publication No. 2008-505740 U.S. Patent Application Publication No. 2014/0074106

One of the problems of the present disclosure is to provide a rod inserter that can be disassembled.

A rod inserter of the present disclosure is for holding a spinal fixation rod, and includes a first elongated member, a tubular grip portion positioned on the rear end side of the first elongated member, a first member including a passageway extending from a distal end of the first elongate member toward the grip; and a second elongate member configured to move along the passageway of the first member. a second member including a member; a rod-shaped third member that is engaged with the rear end side of the second member and inserted through the grip; and the grip that surrounds the third member. a cylindrical lock knob partly inserted through the grip portion and rotatably locked to the grip portion with a central axis parallel to the longitudinal direction of the grip portion. The distal end portion of the first member and the distal end portion of the second member can cooperate with each other to form a grasping portion that grasps the spinal fixation rod. The third member can take three positions with respect to the first member: a gripping position where the gripping portion grips the spinal fixation rod, a release position where the grip is released, and a pushing position. . The lock knob is at a first position with respect to the grip portion when the third member is at the gripping position and the release position, and is at the grip portion when the third member is at the pushed position. can assume a second position with respect to Then, when the lock knob is at the second position, it is possible to release the interlocking of each member.

Disassembly is possible with the rod inserter of the present disclosure.

FIG. 12 is a side view of a rod inserter in accordance with an embodiment of the present disclosure; It is the side view which looked at the rod inserter shown in FIG. 1 from A1 direction. 3 is an enlarged cross-sectional view along line BB shown in FIG. 2; FIG. FIG. 2 is an exploded perspective view of the rod inserter shown in FIG. 1; 5 is an enlarged perspective view of the lock knob of the rod inserter shown in FIG. 4 as seen from another direction; FIG. FIG. 4 is a side view showing a gripping position (first position of the lock knob) of the third member in the rod inserter shown in FIG. 1; FIG. 7 is a partially cutaway side view of the rod inserter shown in FIG. 6 as viewed from direction A2; 8 is an enlarged view of the periphery of the grip portion in the rod inserter shown in FIG. 7; FIG. FIG. 3 is a partially cutaway side view showing the release position (first position of the lock knob) of the third member in the rod inserter shown in FIG. 1; FIG. 10 is an enlarged side view of the periphery of the grip portion in the rod inserter shown in FIG. 9 as seen from direction A3, and is a view corresponding to FIG. 8 ; FIG. 3 is a partially cutaway side view showing a pushing position (second position of the lock knob) of the third member in the rod inserter shown in FIG. 1 ; FIG. 12 is an enlarged side view of the periphery of the grip portion in the rod inserter shown in FIG. 11 as seen from direction A4, and is a view corresponding to FIG. 8 ;

Hereinafter, rod inserters according to embodiments of the present disclosure will be described in detail with reference to the drawings. However, for convenience of explanation, the drawings referred to below show only the configurations necessary for explaining the embodiments in a simplified manner. Accordingly, rod inserters of the present disclosure may comprise any configuration not shown in the referenced figures. In addition, the dimensions of the configuration in the drawings do not faithfully represent the dimensions and dimensional ratios of the actual configuration.

A rod inserter 1 shown in FIGS. 1 and 6 is for holding a spinal fixation rod 100 (hereinafter sometimes referred to as "rod 100"). In other words, the rod inserter 1 is for a PPS (Percutaneous Pedicle Screw) procedure in a PS (Pedicle Screw) method. The rod inserter 1 can grip the rod 100 with a slide mechanism and can be disassembled. The configuration of the rod inserter 1 will be specifically described below.

The rod inserter 1 has a first member 2, a second member 3, a third member 4 and a lock knob 5, as shown in FIGS. 1-4.

As shown in FIG. 4, the first member 2 includes a first elongated member 21, a cylindrical grip portion 22 located on the side of the rear end 21b of the first elongated member 21, and a first and a passageway 23 extending from the distal end 21a side of the elongated member 21 toward the grip portion 22. Note that the first elongated member 21, the grip portion 22 and the passage 23 may be integrally formed or may be configured as separate members. The grip portion 22 illustrated in FIG. 4 is cylindrical, but is not limited to this.

The second member 3 comprises a second elongated member 31 configured to move along the passageway 23 of the first member 2 . The second elongated member 31 illustrated in FIG. 1 is configured to slide relative to the first elongated member 21 . A slide mechanism for gripping the rod 100 is configured by the first elongated member 21 and the second elongated member 31 .

The third member 4 is a rod-shaped member that is engaged with the rear end 3b side of the second member 3 and inserted through the grip portion 22, as shown in FIGS. The second member 3 illustrated in FIG. 4 includes a first locking portion 32 located on the side of its rear end 3b, and the third member 4 is located on the side of its tip 4a and has a first includes a second locking portion 41 that can be locked to the locking portion 32 of the second locking portion 41 . Then, as shown in FIG. 3 , the third member 4 is inserted through the grip portion 22 while the second locking portion 41 is locked to the first locking portion 32 .

In addition, although the third member 4 illustrated in FIG. 4 has a cylindrical shape, it is not limited thereto. The rear end 4b side of the third member 4 can be exposed from the rear end 22b of the grip portion 22, and can function as a button portion when the third member 4 is moved.

As shown in FIGS. 3 and 4, the lock knob 5 is partially inserted into the grip portion 22 so as to surround the third member 4, and is centered in a direction parallel to the major axis S1 direction (longitudinal direction) of the grip portion 22. It is a cylindrical member that is rotatably locked to the grip portion 22 as the shaft S2.

Although the lock knob 5 illustrated in FIG. 4 is cylindrical, it is not limited to this. The lock knob 5 illustrated in FIG. 4 also includes a flange portion 51 positioned on the rear end 5b side of the lock knob 5 . The flange portion 51 has an outer diameter larger than the inner diameter of the grip portion 22 and can function as a locking portion for the grip portion 22 .

Here, as shown in FIGS. 1 and 6, the distal end portion 24 of the first member 2 and the distal end portion 33 of the second member 3 can cooperate with each other to form a gripping portion 6 that grips the rod 100. be. The tip portion is a portion corresponding to the tip, and may mean a region near the tip.

With respect to the first member 2, the third member 4 has a gripping position P1 (see FIGS. 6 to 8) where the gripping portion 6 grips the rod 100, and a release position P2 (FIGS. 9 and 8) where the grip is released. 10) and the pushed position P3 (see FIGS. 11 and 12).

The lock knob 5 is at the first position P4 (see FIGS. 6 to 10) with respect to the grip portion 22 when the third member 4 is at the gripping position P1 and the release position P2, and the third member 4 is pushed. When in the position P3, the grip portion 22 can assume a second position P5 (see FIGS. 11 and 12). Then, when the lock knob 5 is at the second position P5, it is possible to release the interlocking of each member (the first member 2, the second member 3, the third member 4 and the lock knob 5).

According to the above-described configuration, since each member constituting the rod inserter 1 can be disassembled, for example, each disassembled member can be washed, and the rod inserter 1 can be kept clean. . In addition, since the lock knob 5 is in the first position P4 when the rod 100 is gripped or released, it is possible to prevent unintended release of the interlocking of each member while the rod inserter 1 is in use. can do.

The second position P5 illustrated in FIGS. 11 and 12 is obtained by rotating the lock knob 5 from the first position P4 by 45° with respect to the central axis S2. It is not limited to this.

The lock knob 5 may include a crank-shaped groove 52 passing through the lock knob 5 in the thickness direction, as shown in FIGS. 4 and 5 . The groove 52 illustrated in FIG. 5 is connected to a first portion 521 extending in a direction parallel to the central axis S2 in order from the rear end 5b side of the lock knob 5, and the first portion 521. It includes a second portion 522 extending in a direction perpendicular to S2 and a third portion 523 connected to the second portion 522 and extending in a direction parallel to the central axis S2.

As shown in FIGS. 3 and 4, the third member 4 may include a through hole 42 radially penetrating the third member 4 . Moreover, the rod inserter 1 may further have a pin 7 inserted through the through hole 42 so that the end portion 7a is exposed. The end portion 7 a of the pin 7 exposed from the through hole 42 may be movable along the crank-shaped groove 52 in the lock knob 5 .

Movement of the end 7 a of the pin 7 corresponds to movement of the third member 4 . When the third member 4 takes the gripping position P1, the end portion 7a is located on the side of the rear end 521b of the first portion 521 in the groove 52 (see FIGS. 5 and 8). Further, when the third member 4 takes the release position P2, the end portion 7a is located on the side of the tip 521a of the first portion 521 (see FIGS. 5 and 10). Then, when the third member 4 takes the pushed position P3, the end portion 7a is located on the side of the tip 523a of the third portion 523 (see FIGS. 5 and 12).

When the end portion 7a is located on the side of the tip 523a of the third portion 523, the first locking portion 32 (the rear end 3b of the second member 3) and the second locking portion 41 (the third A tip 4 a ) of the member 4 is pushed out of the grip portion 22 . As a result, the interlocking of the second member 3 and the third member 4 is released. Further, since the lock knob 5 can be pulled out from the rear end 22b side of the grip portion 22, the interlocking of the first member 2, the third member 4 and the lock knob 5 is also released.

The pin 7 may be omitted by providing a convex portion corresponding to the end portion 7a of the pin 7 on the outer peripheral portion of the third member 4 . In this case, the number of parts of the rod inserter 1 can be reduced.

The rod inserter 1 may further have a spring member 8 as shown in FIG. The spring member 8 is located inside the grip portion 22 and between the third member 4 and the lock knob 5, as shown in FIG. 4 may be activated. When these configurations are satisfied, when the third member 4 is pushed toward the second member 3, the third member 4 is pushed back by the spring member 8, so that the third member 4 is held at the gripping position P1. and the release position P2, the operability is high. Further, the lock knob 5 cannot be moved to the second position P5 unless the third member 4 is pushed. Therefore, malfunction can be prevented.

The spring member 8 may be locked on the tip 4a side of the through hole 42 in the third member 4 . The third member 4 exemplified in FIGS. 3 and 4 includes a stepped portion 43 located closer to the tip 4 a than the through hole 42 and having an outer diameter larger than the inner diameter of the spring member 8 . Then, the spring member 8 is locked to the stepped portion 43 .

The second member 3 may further include a stopper 34 having an outer diameter larger than the inner diameter of the grip portion 22, as shown in FIGS. When such a configuration is satisfied, it is possible to prevent the region of the second member 3 located closer to the tip 3 a than the stopper 34 from moving into the grip portion 22 . The stopper 34 illustrated in FIGS. 3 and 4 is located closer to the distal end 3 a than the first engaging portion 32 .

As shown in FIG. 7 , the thickness W of the gripping portion 6 may be the same as the diameter of the rod 100 . When such a configuration is met, there is a great deal of freedom in threading the rod 100 through the head of the pedicle screw. Specifically, the rod 100 is inserted through the head of the pedicle screw, which is a substantially U-shaped portion when viewed from the front. If the thickness W of the gripping portion 6 is the same as the diameter of the rod 100, the gripping portion 6 can enter the head together with the rod 100 without interfering with the head. expensive.

It should be noted that the thickness W of the gripping portion 6 may be substantially the same as the diameter of the rod 100, and there may be a slight difference between the two dimensions as long as the effect is obtained. The thickness W of the grip portion 6 is the dimension of the grip portion 6 in the direction perpendicular to the longitudinal direction of the first member 2 (second member 3).

Lock knob 5 may include external threads located on its outer periphery. The position of the male screw may be, for example, the outer peripheral portion on the side of the distal end 5 a from the flange portion 51 . Moreover, the grip portion 22 may include a female thread that is positioned on its inner peripheral surface and that can be screwed onto the male thread. When these configurations are satisfied, when the lock knob 5 is rotated, the second elongated member 31 can be moved along the passage 23 so that the space in the grip portion 6 becomes narrower, so that the grip force on the rod 100 is increased. can be raised.

Examples of the material of the rod inserter 1 described above include, but are not limited to, stainless steel. The material of each member constituting the rod inserter 1 may be the same as or different from each other.

DESCRIPTION OF SYMBOLS 1... Rod inserter 2... 1st member 21... 1st elongate member 21a... Tip 21b... Rear end 22... Grip part S1... Long shaft 22b. Rear end 23 Passage 24 Tip 3 Second member 3a Tip 3b Rear end 31 Second elongated member 32 First locking portion 33 tip 34 stopper 4 third member 4a tip 4b rear end 41 second locking portion 42 through hole 43 Step portion 5 Lock knob 5a Front end 5b Rear end S2 Center shaft 51 Flange portion 52 Groove 521 First portion
521a tip
521b... rear end 522... second part 523... third part
523a... Tip 6... Grasping portion 7... Pin 7a... End 8... Spring member P1... Gripping position P2... Release position P3... Push position P4... First position P5 Second position 100 Spinal fixation rod

Claims (5)

A rod inserter for holding a spinal fixation rod, comprising:
a first member including a cylindrical grip located on the rear end side;
a second member configured to move along the longitudinal direction of the first member;
a third member engaged with the rear end side of the second member and inserted through the grip portion;
a cylindrical lock knob partially inserted into the grip so as to surround the third member and rotatably locked to the grip ;
a pin passing through the third member and the lock knob ;
With the rotation of the lock knob, the third member moves to a gripping position for gripping the spinal fixation rod , a release position for releasing the grip, and a position behind the second member relative to the first member. It can take three positions, a pushing position where the third member pushes the second member to a position where the end and the tip of the third member are pushed out from the grip ,
A rod inserter wherein, when said third member is in said pushed position , said first member, said second member, and said third member are allowed to release from interlocking. 2. The rod inserter of claim 1, wherein the lock knob includes a crank-like groove extending through the thickness of the lock knob. the third member includes a through-hole radially penetrating the third member;
The pin is inserted through the through hole so that the end is exposed,
3. The rod inserter of claim 2, wherein the end exposed from the through hole is movable along the groove. 3. The spring member further comprises a spring member located inside the grip portion and between the third member and the lock knob and biasing the third member outward from a rear end of the lock knob. 4. A rod inserter according to any one of 1 to 3. The lock knob is at a first position with respect to the grip portion when the third member is at the gripping position and the release position, and is at the grip portion when the third member is at the pushed position. A rod inserter according to any one of claims 1 to 4, capable of assuming a second position with respect to.

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