CN218943475U

CN218943475U - Cross locking screw and system

Info

Publication number: CN218943475U
Application number: CN202221843296.XU
Authority: CN
Inventors: 刘桂奇; 张统; 张晓永; 赵军
Original assignee: First Medical Center of PLA General Hospital
Current assignee: First Medical Center of PLA General Hospital
Priority date: 2022-07-18
Filing date: 2022-07-18
Publication date: 2023-05-02
Anticipated expiration: 2032-07-18

Abstract

The utility model discloses a cross locking screw and a system, which belong to the technical field of orthopedic implants, wherein the cross locking screw comprises a first screw and a second screw, the tail part of the first screw is provided with an instrument driving part, the instrument driving part is provided with a transverse through hole for the second screw to pass through, the instrument driving part is flat and has the thickness smaller than or equal to the outer diameter of the rod part of the first screw, the end surfaces at two sides of the instrument driving part are used as instrument driving surfaces, and the second screw comprises a nail rod for passing through the transverse through hole and a nail cap positioned at the tail part of the nail rod and fixedly connected in the transverse through hole. The cross locking screw and the system are suitable for large-angle included angles, can meet clinical requirements, greatly reduce the volume of the instrument driving part, can not protrude out of the bone surface too much after being implanted into a human body, and are not easy to cause soft tissue injury.

Description

Cross locking screw and system

Technical Field

The utility model relates to the technical field of orthopedic implants, in particular to a cross locking screw and a system.

Background

Fractures are common diseases of people, and common fracture types are femur neck fracture, radius neck fracture and the like. Especially in relation to age, fractures are common in the elderly and should be treated as early as possible once found. For the vast majority of fracture patients, internal fixation is preferred. The existing internal fixation modes are mainly divided into two types: screw systems and steel plate systems. These internal fixation systems rely on screws implanted in the bone marrow cavity for fixation; because a single screw is easy to loosen, a cross locking screw is formed, namely two screws are cross fixed (such as Chinese patent 202110698658.4 and 201620528780.1), so that the screw is self-locked, and the firmness of the internal fixing system is improved.

The existing cross locking screw mainly comprises two screws, wherein an inclined nail channel for the other screw to pass through is arranged on an instrument driving part (most of hexagonal columns) of one screw. The inventor finds in the research process that the existing cross locking screw is only suitable for small-angle included angles (namely less than or equal to 60 degrees), is not suitable for large-angle included angles, cannot meet clinical requirements, has a large volume of an instrument driving part, protrudes out of a bone surface after being implanted into a human body, and is easy to cause soft tissue injury.

Disclosure of Invention

The utility model aims to solve the technical problem of providing a cross locking screw and a system which are suitable for large-angle included angles and small in size.

In order to solve the technical problems, the utility model provides the following technical scheme:

in one aspect, a cross locking screw is provided, including first screw and second screw, the afterbody of first screw is equipped with the apparatus drive portion, be equipped with on the apparatus drive portion and supply the horizontal through-hole that the second screw passed, the apparatus drive portion is platykurtic and thickness less than or equal to the external diameter of the shank portion of first screw, the both sides terminal surface of apparatus drive portion is used as the apparatus driving face, the second screw is including being used for passing the nail pole of horizontal through-hole and being located the nail pole afterbody is used for fixed connection to be in the nail cap in the horizontal through-hole.

Further, the transverse through hole is provided with an internal thread, and the nut of the second screw is provided with an external thread matched with the internal thread.

Further, the nut of the second screw is tapered from the tail part of the second screw to the head part of the second screw, and the transverse through hole is a tapered hole which is adaptive to the nut;

and/or the thread pitch on the nut of the second screw is smaller than the thread pitch on the shank of the second screw.

Further, an included angle between the axis of the transverse through hole and the axis of the first screw is 70-110 degrees.

Further, the instrument driving part is in a circular ring shape.

In another aspect, a cross-locking system is provided, comprising the cross-locking screw described above, and a holder for holding and driving a first screw of the cross-locking screws.

Further, the gripping device comprises a T-shaped handle, a gripping driving part is arranged at the front end of the T-shaped handle, and a slot matched with the instrument driving part of the first screw is arranged on the end face of the gripping driving part.

Further, the tail end of one side end face of the instrument driving part is provided with a vertical U-shaped positioning groove, and the inner side wall of one side of the groove is provided with a positioning convex rib matched with the U-shaped positioning groove.

Furthermore, screw avoiding grooves for avoiding the second screws are formed in the front end of the holding driving part on the two side walls of the groove.

Further, the tail end of one side end face of the instrument driving part is provided with a positioning hole, a vertical rod part of the T-shaped handle is internally provided with a positioning rod installation channel which extends into the holding driving part and is communicated with the slot, the positioning rod installation channel is internally hinged with a positioning rod, the front end of the positioning rod is provided with a positioning protrusion which extends out of the positioning rod installation channel into the slot and is matched with the positioning hole, a spring used for enabling the positioning protrusion and the positioning hole to keep a matched state is arranged between the rear end of the positioning rod and the side wall of the positioning rod installation channel, and the rear end of the positioning rod is provided with an operation button which extends out of the positioning rod installation channel and is positioned on the outer surface of the vertical rod part of the T-shaped handle.

The utility model has the following beneficial effects:

the cross locking screw and the system are suitable for large-angle included angles, can meet clinical requirements, greatly reduce the volume of the instrument driving part, and can not protrude out of a bone surface too much after being implanted into a human body, and soft tissue injury is not easy to cause compared with the instrument driving part with an outer hexagonal column or an inner hexagonal hole in the prior art.

Drawings

FIG. 1 is a schematic view of the overall construction of the cross-lock system of the present utility model;

FIG. 2 is a schematic view of the structure of a first screw of the cross-locking system of the present utility model, wherein (a) is a front view, (b) is a side sectional view, and (c) is an enlarged view at the instrument drive;

FIG. 3 is a schematic view of a second screw in the cross-locking system of the present utility model, wherein (a) is a front view, (b) is a front cross-sectional view, and (c) is a view in the aft direction;

FIG. 4 is a schematic view of the structure of the holder in the cross-lock system of the present utility model, wherein (a) is a front view and (b) is a perspective view;

fig. 5 is a schematic view showing a modified structure of the cross-locking system of the present utility model, in which (a) is a modified structure of a vertical rod portion of a T-shaped handle of a holder, and (b) is a modified structure of an instrument driving portion of a first screw.

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved more apparent, the following detailed description will be given with reference to the accompanying drawings and specific embodiments.

In one aspect, the present utility model provides a cross locking screw, as shown in fig. 1-3, comprising a first screw 1 and a second screw 2, wherein the tail part of the first screw 1 is provided with an instrument driving part 11, the instrument driving part 11 is provided with a transverse through hole 12 for the second screw 2 to pass through, the instrument driving part 11 is flat and has a thickness less than or equal to the outer diameter of a rod part 13 of the first screw 1, two side end surfaces of the instrument driving part 11 are used as instrument driving surfaces 14, and the second screw 2 comprises a nail rod 21 for passing through the transverse through hole 12 and a nail cap 22 positioned at the tail part of the nail rod 21 and fixedly connected in the transverse through hole 12.

When the screw is used in operation, the first screw 1 is held by the holder 3, a proper screw feeding point is selected to be screwed into one side of a fracture part, after the first screw 1 is screwed into a corresponding position, the second screw 2 is held to enable the screw rod 21 of the second screw to pass through the transverse through hole 12 on the instrument driving part 11 of the first screw 1, a proper screw feeding point is selected to be screwed into a corresponding position, and the screw cap 22 of the second screw 2 is fixedly connected in the transverse through hole 12, so that the implantation of the cross locking screw is completed.

The cross locking screw is suitable for large-angle included angles, can meet clinical requirements, greatly reduces the volume of the instrument driving part, does not protrude out of a bone surface too much after being implanted into a human body, and is not easy to cause soft tissue injury. The utility model is mainly suitable for internal fixation operations, such as femur internal fixation operations, radius internal fixation operations, spine internal fixation operations, and the like.

As shown in fig. 2-3, the transverse through hole 12 may be provided with an internal thread 121, and the nut 22 of the second screw 2 is provided with an external thread 221 matching with the internal thread 121, so that the nut 22 of the second screw 2 gradually approaches and screws into the transverse through hole 12 during screwing of the second screw 2, so as to lock the first screw 1 and the second screw 2. At this time, since the screw shaft 21 and the nut 22 of the second screw 2 are provided with threads, they are also called double-threaded screws. The tail end of the nut 22 of the second screw 2 is provided with an instrument operation hole (specifically, a plum blossom hole 23), and the second screw 2 can be manually held and screwed by a plum blossom spanner.

Further, the nut 22 of the second screw 2 may be tapered from the tail to the head of the second screw 2, and the transverse through hole 12 is a tapered hole adapted to the nut 22, so as to enhance the locking effect and improve the firmness between the first screw 1 and the second screw 2. The pitch of the threads on the nut 22 of the second screw 2 is preferably smaller than the pitch of the threads on the shank 21 of the second screw 2.

As shown in fig. 2 (b), the included angle α between the axis of the transverse through hole 12 and the axis of the first screw 1 may be 70-110 degrees, preferably 80-100 degrees, and specifically may be 80 degrees, 85 degrees, 90 degrees, 95 degrees, 100 degrees, etc. to satisfy clinical requirements. The thickness H of the instrument driving portion 11 is preferably 1/2 to 3/4 of the outer diameter of the shaft portion 13 of the first screw 1 to minimize the volume occupation while securing the strength of the instrument driving portion 11. The instrument driving portion 11 is preferably circular in shape to reduce the volume and prevent soft tissue damage. In addition, the head of the first screw 1 may be provided with a first cutting edge 17; the head of the second screw 2 may be provided with a second cutting edge 24 to facilitate screwing.

In another aspect, the present utility model provides a cross-locking system, as shown in fig. 1-5, comprising a cross-locking screw as described above, and a holder 3 for holding and driving a first screw 1 of the cross-locking screws. Since the cross locking screw is constructed as above, it will not be described in detail herein.

The cross locking system is suitable for large-angle included angles, can meet clinical requirements, greatly reduces the volume of the instrument driving part of the first screw of the cross locking screw, does not protrude out of a bone surface too much after being implanted into a human body, and is not easy to cause soft tissue injury.

As shown in fig. 1 and 4, the gripper 3 may include a T-shaped handle 31, where a gripping driving portion 32 is disposed at a front end of the T-shaped handle 31, and a slot 33 for matching with the instrument driving portion 11 of the first screw 1 is disposed on an end surface of the gripping driving portion 32, so as to facilitate gripping and feeding (driving and screwing in), and meanwhile, the T-shaped handle 31 may provide a larger torque force, so that the staple taking is more labor-saving, and the locking effect is improved. The depth of the slot 33 is preferably equal to or greater than the height of the instrument driver 11, i.e., the grip driver 32 wraps around the instrument driver 11 to improve the stability and robustness therebetween.

Further, the tail end of one side end face (i.e. one of the instrument driving faces 14) of the instrument driving portion 11 may be provided with a vertical U-shaped positioning groove 15, and a positioning rib 34 (U-shaped positioning rib) matched with the U-shaped positioning groove 15 is provided on an inner side wall of one side of the slot 33, so that the positioning rib 34 is matched with the positioning groove 15, and the holder 3 can be prevented from being separated from the instrument driving portion 11 in the transverse direction, so as to facilitate holding and stapling.

As shown in fig. 1, the front end of the holding driving part 32 may be provided with screw avoiding grooves 35 (not shown in fig. 4 b) for avoiding the second screw 2 on both side walls of the groove 33, so that after the first screw 1 is screwed into place using the holder 3, the second screw 2 can be implanted without removing the holder 3 due to the screw avoiding grooves 35.

In an improved embodiment, as shown in fig. 5, a positioning hole 16 may be formed at the tail end of one side end face (i.e. one of the instrument driving faces 14) of the instrument driving portion 11, a positioning rod mounting channel 36 extending into the holding driving portion 32 and communicating with the slot 33 is formed in the vertical rod portion of the T-shaped handle 31, a positioning rod 37 is hinged in the positioning rod mounting channel 36 (specifically, the middle part of the positioning rod 37 may be hinged in the positioning rod mounting channel 36 and may be hinged by a pin 371), a positioning protrusion 38 extending out of the positioning rod mounting channel 36 into the slot 33 and matching with the positioning hole 16 is formed at the front end of the positioning rod 37, a spring 39 for keeping the positioning protrusion 38 and the positioning hole 16 in a matching state is formed between the rear end of the positioning rod 37 and the side wall of the positioning rod mounting channel 36, and an operation button 30 extending out of the positioning rod mounting channel 36 and located on the outer surface of the vertical rod portion of the T-shaped handle 31 is formed at the rear end of the positioning rod 37.

When the device is unlocked, the operation button 30 is pressed, the positioning rod 37 rotates along the pin 371 under the action of the operation button 30, the spring 39 is compressed under the stress, and the positioning protrusion 38 is separated from the positioning hole 16, so that the device can be unlocked or smoothly docked with the device driving part 11; when the locking is realized, the operation button 30 is released, the spring 39 is relaxed, the positioning rod 37 rotates along the pin 371 under the action of the elastic force of the spring 39, and the positioning protrusion 38 falls into the positioning hole 16.

While the foregoing is directed to the preferred embodiments of the present utility model, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present utility model, and such modifications and adaptations are intended to be comprehended within the scope of the present utility model.

Claims

1. The utility model provides a cross locking screw, includes first screw and second screw, the afterbody of first screw is equipped with the apparatus drive portion, its characterized in that, be equipped with on the apparatus drive portion and supply the horizontal through-hole that the second screw passed, the apparatus drive portion is platykurtic and thickness less than or equal to the external diameter of the pole portion of first screw, the both sides terminal surface of apparatus drive portion is used as the apparatus driving surface, the second screw is including being used for passing the nail pole of horizontal through-hole and being located the nail pole afterbody is used for fixed connection to be in the nail cap in the horizontal through-hole.

2. The cross locking screw as claimed in claim 1, wherein the transverse through hole is provided with an internal thread, and the nut of the second screw is provided with an external thread which mates with the internal thread.

3. The cross locking screw of claim 2, wherein the nut of the second screw is tapered from the tail of the second screw to the head, and the transverse through hole is a tapered hole adapted to the nut;

4. The cross-locking screw of claim 1, wherein the angle between the axis of the transverse through hole and the axis of the first screw is 70-110 degrees.

5. The cross-locking screw of claim 1, wherein the instrument driver is annular.

6. A cross-locking system comprising the cross-locking screw of any one of claims 1-5 and a driver for driving and driving a first one of the cross-locking screws.

7. The cross-locking system of claim 6, wherein the holder comprises a T-handle having a holding drive at a front end thereof, the holding drive having a slot in an end face thereof for mating with the instrument drive of the first screw.

8. The cross locking system according to claim 7, wherein a vertical U-shaped positioning groove is formed at the tail end of one side end face of the instrument driving part, and a positioning rib matched with the U-shaped positioning groove is formed on the inner side wall of one side of the groove.

9. The cross locking system of claim 7, wherein the front end of the holding driving part is provided with screw avoiding grooves for avoiding the second screw on both side walls of the groove.

10. The cross locking system according to claim 7, wherein a positioning hole is formed in the tail end of one side end face of the instrument driving part, a positioning rod installation channel which extends into the holding driving part and is communicated with the slot is formed in the vertical rod part of the T-shaped handle, a positioning rod is hinged in the positioning rod installation channel, a positioning protrusion which extends out of the positioning rod installation channel into the slot and is matched with the positioning hole is arranged at the front end of the positioning rod, a spring for enabling the positioning protrusion and the positioning hole to be kept in a matched state is arranged between the rear end of the positioning rod and the side wall of the positioning rod installation channel, and an operation button which extends out of the positioning rod installation channel and is positioned on the outer surface of the vertical rod part of the T-shaped handle is arranged at the rear end of the positioning rod.