JP7160687B2 - self-locking orthopedic screwdriver - Google Patents

Description

The present invention relates to self-locking drivers for the installation, fastening and/or unfastening of orthopedic implants anchored within the tissue of the bone body of a subject.

From EP 2 962 651 a removable driver is known which allows the fixation of bone screws for holding orthopedic implants to bone bodies, more particularly for fixing connectors for spinal implants. be.

The removable driver includes a coupling portion that enables the drive of the rod, the coupling portion being screwed into the tulip-shaped interior of the spinal implant connector, while the distal end portion of the rod is: It cooperates with the head of the pedicle screw.

This type of driver must, on the one hand, maintain the connector and, on the other hand, allow the rotational drive of the fixation screw for fixation within the bony tissue.

It has been found that this type of driver can detach from the connector to be fixed under the action of external resistance, thus inducing misguiding of the implant and embrittlement of the fastening rod.

EP 2962651

The driver according to the present invention aims to solve this problem by proposing a blocking system that can temporarily lock said driver on the implant while anchoring the fixation screw in the bone tissue. there is

A self-locking driver according to the present invention includes a guide tube in which a fastening rod is guided and driven to rotate, and one of the ends of the fastening rod is positioned relative to the bony body of the subject. A socket is provided to allow rotational drive and tightening of the fixation screw that immobilizes the orthopedic implant, said driver cooperating with said guide tube, on the one hand, between the guide tube and the fastening rod. to prevent the orthopedic implant from being unfastened from this guide tube during anchoring screw fastening, while on the outer circumference of the guide tube, locking and/or unlocking the blocking system. and a gripping wheel for driving rotation of said guide tube.

The self-locking driver according to the invention includes a blocking system consisting of a link rod which cooperates with a retractable stop provided in the guide tube depending on the direction of rotation of the link rod. Contains teeth on the circumference.

A self-locking driver in accordance with the present invention includes a retractable stopper having a C-shaped profile that includes an angled profile within the opening.

The self-locking driver according to the invention comprises a retractable stopper internally provided with a flexible blade with one tooth on the inner face directed towards the inside of said guide tube.

A self-locking driver in accordance with the present invention includes a retractable stop having teeth presenting an arcuate profile disposed within a circular profile extension of the inner bore of the guide tube.

The self-locking screwdriver according to the invention comprises a coupling device consisting of an elastically deformable lamellar structure capable of accommodating an internal blind bore on the one hand and a fastening rod on the other hand and preventing its translational movement and rotation, Including a link rod contained within the extension of the tooth.

The self-locking driver according to the present invention includes a torque transmitting pad opposite the retractable stop of the guide tube (3).

A self-locking driver according to the present invention has a first space within which a retractable stopper cooperates, and a second space located opposite the first space and containing a torque transmitting pad therein. including gripping wheels including

The self-locking driver according to the invention includes a cam inside the first space of the gripping wheel, the outer contour of which comes into contact with the beveled contour of the opening of the retractable stopper .

The self-locking driver according to the invention has a first abutment, called a "threading abutment", near the outer bore of the guide tube, and on the opposite side, centered around the guide tube. A second abutment having an internal contour that allows it to define a second abutment, called a "threading abutment", on which the torque transmitting pads are supported, depending on the direction of rotation of the gripping wheel. contains space.

The following description makes it possible to better understand the features that the invention has and the advantages that it can offer, in the light of the accompanying drawings, given as non-limiting examples.

1 is a perspective view illustrating a self-locking driver for placement and fixation of orthopedic implants in accordance with the present invention; FIG. 1 is a side view of a self-locking screwdriver according to the present invention; FIG. 1 is a cross-sectional view of a self-locking screwdriver according to the present invention; FIG. FIG. 3 illustrates the guide tube of the self-locking driver in accordance with the present invention; FIG. 3 illustrates the guide tube of the self-locking driver in accordance with the present invention; FIG. 3 illustrates the guide tube of the self-locking driver in accordance with the present invention; Fig. 3 represents the link rod of the blocking means of the self-locking driver according to the invention; Fig. 3 represents the link rod of the blocking means of the self-locking driver according to the invention; Fig. 3 shows a retractable stop of the blocking means of the self-locking driver according to the invention; Fig. 3 shows a retractable stop of the blocking means of the self-locking driver according to the invention; FIG. 5 is a cross-sectional view illustrating locking and unlocking positions of the blocking means of the self-locking screwdriver according to the present invention; FIG. 5 is a cross-sectional view illustrating locking and unlocking positions of the blocking means of the self-locking screwdriver according to the present invention;

1-3 show a self-locking driver 1 according to the invention comprising a guide tube 3 and a fastening rod 4 cooperating with a U-shaped connector 2a and an anchoring screw 6 of an orthopedic implant 2, respectively.
It is shown.

The fixation screw 6 has a head 6a with a spherical profile supported on the bottom of the U-shaped profile of said connector 2a, said connector in relation to the axis of implantation of said fixation screw 6 into the bone body of the vertebrae Ve. is envisioned to traverse the connector 2a in order to ensure angular and positional freedom of the .

The immobilization of the connector 2a in its final angular position about the axis of the fastening screw 6 is effected upon installation of the link rods at the bottom of the U-profile of said connector, which connector is connected to this Through a fastening screw, not shown, cooperating with a threaded zone 2b provided in the inner upper part of the U-profile of the connector, it is translationally and rotationally immobile with respect to the head 6a of said screw 6. will be blocked.

Being free to move between the connector 2a and the fixing screw 6, the driver 1 should necessarily be immobilized within said connector while allowing a rotational drive of the fixing screw 6.

The self-locking driver 1 comprises a threaded external thread cooperating with an internal threaded zone 2b of the connector 2a in such a way as to ensure immobilisation of said driver 1 within said connector 2a of an orthopedic implant 2. It includes a guide tube 3 with a contour 3a at one end thereof.

At the opposite end of the threaded profile 3a, the guide tube 3 includes a retractable stop 11 on its circumference and a transmission pad 12 along a diametrically opposite direction.

The retractable stop 11 has a C-shaped profile, the opening 11a of which is oriented in the direction of the threaded profile 3a. The retractable stop 11 is obtained by machining the external wall of the guide tube 3 defining flexible blades which guarantee said retractable stop a certain degree of freedom of movement in relation to the longitudinal axis of the guide tube.

The flexible blade 11b of the retractable stop 11 has, on its inner face directed towards the inside of the inner bore 3b of the guide tube 3, an arcuate profile located within the extension of said inner bore's circular profile. includes a tooth 11c having a

A retractable stop 11 and a transmission pad 12 are arranged around the guide tube 3, allowing the retractable stop to move or not depending on its direction of rotation about the tube. It cooperates with gripping wheels 8 .

The gripping wheel 8 comprises a first space 8a inside which the C-shaped profile of the retractable stopper 11 cooperates. Inside the first space 8a is the inclined profile of the opening 11a when the gripping wheel 8 is rotated so that the teeth 11c of the retractable stopper 11 are moved away from or closer to the central longitudinal axis of the guide tube 3. A cam 15 is provided which has an outer contour that contacts 11d (FIGS. 11 and 12).

The gripping wheel 8 is arranged opposite the first space 8a and includes a second space 8b in which torque transmitting pads 12 provided on the circumference of the guide tube 3 are accommodated.

The second space 8b comprises a first abutment 13 called "threaded abutment" near the external bore of the guide tube and on the other side a gripping centering around said guide tube. It has an internal contour that makes it possible to define a second abutment 14, called a "threading abutment", on which the pad 12 rests, depending on the direction of rotation of the wheel 8.

The self-locking driver 1 comprises between the guide tube 3 and the fastening rod 4 a link rod 9 with which said guide tube can be connected to a retaining grip 16 .

Link rod 9 includes on one end and on its circumference a series of teeth 10 having an external contour that is complementary to the external contour of teeth 11 c of retractable stopper 11 .

The link rod 9 comprises a coupling device 17 consisting of an internal blind bore 17a on the one hand and an elastically deformable lamellar structure 17b on the other hand capable of accommodating the fastening rod 4 and preventing its translational movement and rotation. 10 contained within the extension.

The fastening rod 4 has an internal socket provided in the head 6a of the fastening screw 6 to allow rotational driving of the fastening screw 6 when the guide tube 3 is immobilized on the connector 2a. It has a cooperating external socket 5 on the opposite side of the connection with the link rod 9 .

From the above description it can be seen that the placement of the orthopedic implant 2 in the vertebrae Ve is performed in the following manner:
- to position the torque-transmitting pad 12 against a first abutment 13, called "screw-in abutment", such that the torque-transmitting pad 12 transmits rotational torque to the guide tube 3; The gripper 8 is driven to rotate clockwise about the guide tube 3;
- the profile and angle given to the tooth 10 of the link rod 9 and the tooth 11c of the retractable stop 11, respectively, allow the tooth 11c to pop out of said tooth 10 of the link rod 9 during the rotational drive of the guide tube 3; becomes. This direction of rotation is therefore unobstructed and the guide tube 3 can be screwed into the connector 2 a of the implant 2 .
- when the guide tube 3 is completely immobilized in the connector 2a of the implant 2, the fastening rod 4 is rotationally driven via the grip 16 and the link rod 9 for anchoring in the bony body of the vertebrae Ve; A screw 6 is screwed in to fix the implant 2 .

In the case of external friction, e.g. induced by adjacent muscle tissue on the guide tube 3, which induces adverse stresses which may cause said guide tube 3 of the implant 2 to screw out, this guide tube This guide tube actually rotates counterclockwise by means of a blocking system consisting of teeth 11c of retractable stopper 11 which oppose and contact corresponding teeth 10 of link rod 9 which prevent 3 from screwing out of connector 2. It is pointed out that it is restrained so as not to rotate

Similarly, from the above description, it can be seen that the blocking system of the driver 1 is locked so that the guide tube 3 can be screwed out of the connector 2a of the implant 2 after fixation in the bone using the fixation screw 6. It is also known that it can be released.

Unlocking of the blocking system is effected by counterclockwise movement of the gripping wheel 8 about the guide tube 3 .

In fact, the rotational play between the gripping wheel 8 and the guide tube 3 causes the tooth 11c to move from the retractable stop 11 which is lifted during rotation by the cam profile 15 provided in the first space of the gripping wheel 8. making it possible to release

Teeth 11 c are thus released from teeth 10 of link rod 9 .

During the counterclockwise rotation of the gripping wheel 8, the torque transmitting pad 12 simultaneously engages a second abutment, called a "screw abutment", provided in the second space 8b of said wheel. It touches the part 14.

At this time, the rotational torque is transmitted to the guide tube 3, which is screwed out from the connector 2a of the implant 2. FIG.

A blocking system arranged to lock the counterclockwise rotation of the guide tube 3, particularly when the anchoring screw 6 is independent of the connector 2a of the implant 2, is useful for the use of the driver 1 and its penetration into the bone. It is pointed out that it facilitates fastening of the fixing screw 6 .

Furthermore, the above description is given by way of example only and does not in any way limit the scope of the invention, and any substitution of any other equivalents for the above implementation details may depart from the scope of the invention. It should be understood that no

Claims (9)

a guide tube (3), and
A self-locking driver (1) comprising a fastening rod (4) located inside said guide tube (3),
At a first end of said fastening rod (4) is a rotational drive of an anchoring screw (6) for immobilizing the orthopedic implant (2) relative to the bone body of the subject, and said is provided with a socket (5) enabling fastening of the fastening screw (6) to the end of said fastening rod (4),
a blocking system (9, 10 and 11) is provided between said guide tube (3) and said fastening rod (4) ,
A gripping wheel (8) is provided on the outer circumference of said guide tube (3), said gripping wheel (8) for locking and/or unlocking said blocking system (9, 10 and 11) and said Rotating the guide tube (3),
Said blocking system (9, 10 and 11) comprises a link rod (9), said link rod (9) being formed in said guide tube (3) depending on the direction of rotation of said link rod (9). comprising on its periphery a series of teeth (10) cooperating with a retractable stop (11);
Said retractable stopper (11) comprises a flexible blade (11b), said flexible blade (11b) is provided on the inner surface of said flexible blade (11b) and inside said guide tube (3) with one tooth (11c) directed toward
Said orthopedic implant (2) has a U-shaped connector (2a) and said anchoring screw (6) has a head (6a) of spherical profile, said head (6a) (2a), said connector (2a) being prevented from translational and rotational movement with respect to said head (6a) via fastening screws;
said guide tube (3) is threadedly engaged to said orthopedic implant (2),
The blocking system (9, 10 and 11) cooperates with the guide tube (3) to ensure that when the fixation screw (6) is tightened into the bone body, the guide tube (3) Preventing said guide tube (3) from being unfastened from the orthopedic implant (2) by preventing it from rotating opposite to the rotation when threadedly engaged with the orthopedic implant (2). A self-locking screwdriver characterized by: Self-locking screwdriver according to claim 1, characterized in that said retractable stop (11) comprises an oblique profile (11b) and has a C-shape. Self-locking according to claim 1, characterized in that the tooth (11c) has an arcuate profile located in an extension of the circular profile of the internal bore (3b) of the guide tube (3). driver. A connecting device (17) having an internal blind bore (17a) and an elastically deformable lamellar structure (17b) capable of receiving said fastening rod (4) and preventing its translational movement and rotation, said link Self-locking screwdriver according to claim 1, characterized in that a rod (9) comprises a portion axially extending from said series of teeth (10). Self-locking screwdriver according to claim 1, characterized in that said guide tube (3) comprises a torque-transmitting pad (12) facing said retractable stop (11). Said gripping wheel (8) comprises a first space (8a) in which said retractable stopper (11) cooperates and a second space (8a) arranged opposite said first space (8a). 6. The space (8b) of any one of claims 1 to 5, characterized in that it includes a second space (8b) in which a torque transmission pad (12) is accommodated. self-locking screwdriver as described in . A cam (15) is provided inside said first space (8a), the outer contour of said cam coming into contact with the inclined contour (11d) of said retractable stopper (11). 7. A self-locking screwdriver according to claim 6, characterized by: The second space (8b) comprises a first abutment (13) near the outside of the guide tube (3) and a second abutment opposite the first abutment (13). said first abutment (13) depending on the direction of rotation of the gripping wheel (8) about said guide tube (3). 7. A self-locking screwdriver according to claim 6, characterized in that a torque transmission pad (12) is supported on said second abutment. a guide tube (3), and
A self-locking driver (1) comprising a fastening rod (4) located inside said guide tube (3),
At a first end of said fastening rod (4) is a rotational drive of an anchoring screw (6) for immobilizing the orthopedic implant (2) relative to the bone body of the subject, and said is provided with a socket (5) enabling fastening of the fastening screw (6) to the end of said fastening rod (4),
a blocking system (9, 10 and 11) is provided between said guide tube (3) and said fastening rod (4) ,
A gripping wheel (8) is provided on the outer circumference of said guide tube (3), said gripping wheel (8) for locking and/or unlocking said blocking system (9, 10 and 11) and said Rotating the guide tube (3),
Said blocking system (9, 10 and 11) comprises a link rod (9), said link rod (9) being formed in said guide tube (3) depending on the direction of rotation of said link rod (9). comprising on its periphery a series of teeth (10) cooperating with a retractable stop (11);
A connecting device (17) having an internal blind bore (17a) and an elastically deformable lamellar structure (17b) capable of receiving said fastening rod (4) and preventing its translational movement and rotation, said link a rod (9) comprising in a portion axially extending from said series of teeth (10) ,
Said orthopedic implant (2) has a U-shaped connector (2a) and said anchoring screw (6) has a head (6a) of spherical profile, said head (6a) (2a), said connector (2a) being prevented from translational and rotational movement with respect to said head (6a) via fastening screws;
said guide tube (3) is threadedly engaged to said orthopedic implant (2),
The blocking system (9, 10 and 11) cooperates with the guide tube (3) to ensure that when the fixation screw (6) is tightened into the bone body, the guide tube (3) Preventing said guide tube (3) from being unfastened from the orthopedic implant (2) by preventing it from rotating opposite to the rotation when threadedly engaged with the orthopedic implant (2). A self-locking screwdriver characterized by:

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