CN111248992A

CN111248992A - Multifunctional screw

Info

Publication number: CN111248992A
Application number: CN202010118963.7A
Authority: CN
Inventors: 许小波; 宁宇航; 陈涛
Original assignee: Zhejiang Decans Medical Instrument Co ltd
Current assignee: Zhejiang Decans Medical Instrument Co ltd
Priority date: 2019-05-05
Filing date: 2020-02-26
Publication date: 2020-06-09

Abstract

The utility model provides a multifunctional screw which is characterized in that, including the head of a nail, rand, the nail body, retaining ring and locking plug screw. Through above-mentioned technical scheme, this patent both can realize multi-functionally through a screw, can also be convenient for operate and install when multi-functional, improves the fastening effect.

Description

Multifunctional screw

Technical Field

This patent belongs to medical instrument technical field, particularly relates to a multi-functional screw.

Background

In the field of orthopedics, the thoracolumbar posterior pedicle screw is an important and commonly used medical instrument. Which functions to fix the vertebral arch system to the spine of the human body. Since the vertebral arch system requires different fixing and connecting elements in different positions, fixing screws, large-angle deflection screws, universal screws and reduction screws have appeared in the prior art. However, these screws are of a wide variety and are prone to operator error during practical operation, with the consequences of incorrect use of different screws being unthinkable. In addition, due to the various types of screws, high requirements are brought to raw material storage during operation, and much inconvenience is brought to use.

There is an urgent need for a screw having multiple functions in the prior art that can simultaneously satisfy the multiple requirements of thoracolumbar posterior pedicle screws. However, since the screw is an important human body fixing component, simply integrating the functions of the screw in the prior art does not satisfy the actual requirements, and therefore, it is necessary to ensure good effects of various operations besides the function integration.

Disclosure of Invention

This patent is just proposed on prior art's basis, and the technical problem that this patent will be solved provides a multifunctional screw, can satisfy various fixed demands on chest lumbar vertebrae way of escape vertebral arch system.

In order to solve the technical problem, the technical scheme provided by the patent comprises:

a multifunctional screw is characterized by comprising a screw cap, a clamping ring, a screw body, a retainer ring and a locking screw plug, wherein the screw cap is integrally cylindrical, the top of the screw cap is provided with a top opening, and the bottom of the screw cap is provided with a bottom opening; the side wall of the cylindrical nail body is provided with two opposite mounting grooves; internal threads are arranged in the inner wall of the nail cap; a ball socket is arranged on the inner wall of the lower part of the nail cap, a through hole is formed at the bottom end of the ball socket and penetrates through the bottom wall of the nail cap, the cross section of the through hole is integrally circular, and an ear groove is outwards arranged at one circular end; the bottom wall of the nail cap is provided with a bevel, and the through hole 18 is at least partially positioned in the bevel; the nail comprises a nail body, wherein the top end of the nail body comprises a ball head, the ball head is integrally accommodated in the ball socket in a spherical shape, and the lower end of the ball head is connected with a screw rod with threads; the lower end of the ball head is provided with ball threads, and the inner surface of the lower part of the nail cap is provided with corresponding nail cap ball threads; the retainer ring comprises a ring body, and a groove is formed in the upper part of the ring body; the lower part of the retainer ring is attached to the outer surface of the ball head; the upper part of the retainer ring is contacted with the lower surface of the locking screw plug; the locking screw plug comprises an outer screw plug and an inner screw plug, and the periphery of the outer screw plug is provided with threads which are matched with the threads on the inner wall of the screw cap; the bottom of the outer plug screw is in contact with the top of the retainer ring, a through hole is formed in the inner plug screw, an internal thread is formed in the inner wall of the through hole, and the internal thread is matched with the inner plug screw. The periphery of the inner plug screw is also provided with an external thread.

Preferably, be provided with the attenuate recess on the lateral wall of the nail cap that the internal thread of nail cap corresponds, the opening orientation of attenuate recess the outside of lateral wall, the cell body is seted up the thickness direction of lateral wall to at slotted local attenuate the lateral wall of nail cap, the tank bottom of attenuate recess is the V type.

Through above-mentioned technical scheme, this patent both can realize multi-functionally through a screw, can also be convenient for operate and install when multi-functional, improves the fastening effect.

Drawings

FIGS. 1 and 2 are schematic structural views of a conventional universal screw;

fig. 3 and 4 are schematic structural views of the multifunctional screw in the embodiment;

FIG. 5 is a schematic view of the cap and body of the multifunctional screw according to the present embodiment;

FIG. 6 is a schematic cross-sectional view of the mating components of the multifunctional screw in this embodiment;

FIG. 7 is a schematic view of the lower end thread of the nut and the lower end thread of the ball as a fixing screw in the multifunctional screw according to the present embodiment;

FIG. 8 is a schematic view of the lower end thread of the nut and the lower end thread of the ball of the multifunctional screw in the present embodiment as a universal screw;

FIGS. 9 and 10 are schematic views of the inclined plane structure of the bottom end of the nail head;

FIG. 11 is a schematic view of the rotation angle of the nail body in the nail head;

FIG. 12 is a schematic view of the collar;

FIG. 13 is an enlarged partial view of the collar engaging the ball head;

FIG. 14 is a schematic view of the mating interface of the screw and instrument;

fig. 15 is a schematic structural diagram of the locked inner plug and outer plug.

FIG. 16 is a schematic view of the hook lock thread configuration;

fig. 17 is a schematic view of the fitting during centering.

Detailed Description

The following detailed description of the embodiments of the present patent application is provided for illustrative purposes only, and should not be construed as limiting the scope of the present patent application.

As shown in fig. 1, the present embodiment provides a multifunctional screw, which includes a nut 1, a collar, a nail body 2, a retainer ring 3 and a locking plug screw 4.

Nail cap

The nail cap 1 is wholly cylindrical, and its top is provided with open-top 11, the bottom is provided with bottom opening 12, be provided with two mounting grooves 13 that set up relatively on the lateral wall of the cylindric nail body, the mounting groove is used for inserting the fixed stick etc the top end opening of mounting groove is followed the upper end of nail cap is opened, the bottom in groove is located the lower part position of nail cap, the bottom in mounting groove presents circular-arcly to laminate with the circular periphery of connective bar.

In this embodiment, an internal thread 14 is provided in the inner wall of the nut, whereby a locking plug screw is screwed into the nut to lock the connecting rod and the shank. In this embodiment for the convenience will the nail cap realizes multi-functionally be provided with attenuate recess 15 on the lateral wall of the nail cap that the internal thread corresponds, the opening orientation of attenuate recess the outside of lateral wall, the cell body is seted up the thickness direction of lateral wall to at slotted local attenuate the lateral wall of nail cap, the tank bottom of attenuate recess is the V type. Can utilize existing nail cap length when needing longer nail cap through the design of above-mentioned attenuate recess, and when needing shorter nail cap V type department will the nail cap cuts because the design of V type, like can utilize the instrument of lever class can with the nail cap rupture, and need not adopt modes such as sawing, the convenience that has improved like this. Furthermore, an inner wall thinning groove corresponding to the groove in the outer wall is formed in the inner wall of the nail cap, the inner wall thinning groove is a flat-bottom groove, and tests show that the inner wall thinning groove and the outer wall thinning groove are matched, so that the inner wall thinning groove can keep the level of the fracture, and the service performance is improved.

Preferably, in the present embodiment, the internal thread 14 may be provided as a hook lock thread 15, that is, an upward detour groove 16 is provided at the outer edge of the thread, and this thread design can ensure that the nut does not open after the screw plug and nut locking process and locking process, which are critical during the rod setting and final locking process, and can greatly reduce the risk of the screw plug falling out of the nut. Meanwhile, the locking force can be vertically loaded through the hook lock thread design, so that the conversion efficiency from the locking torque to the locking force is higher, and the locking performance and stability of the rod are ensured to the maximum extent.

The bottom end of the ball socket penetrates through the bottom wall of the nail cap to form a through hole 18 at the bottom, the through hole 18 is used for extending a screw part of the nail body out of the nail cap, the section of the through hole 18 is overall in a circular arc shape, an ear groove 19 is outwards arranged at one end of the circular arc to provide a large deflection angle in the direction, when the nail body does not enter the ear groove, the universal rotation angle of the nail body is α degrees like a common screw, and when the nail body rotates into the ear groove, the nail body can have a greater deflection angle β degrees in the direction.

The novel large-angle nail cap has the advantages that the bottom end of the nail cap is provided with the inclined plane 110, the through holes 18 are at least partially positioned in the inclined plane 110, and therefore, the ball head nail body can be allowed to deflect at a larger angle.

The technical requirement for nail placement is very high when the pedicle screws are used for fixing, if the U-shaped grooves of the two nails are not parallel, the connecting rod and the U-shaped grooves are changed from surface contact into point contact, stress concentration is formed, and the nails or the rods are easy to break; when more than two vertebral bodies are fixed, the directions of the screw caps are fixed after the pedicle screws on one side are implanted, the U-shaped grooves of the screw caps are not in the same straight line, so that the connecting rod is difficult to place, the risk of stress concentration is also faced, and the screw which is not in the straight line is easy to loosen or break after the U-shaped grooves are strongly combined into the straight line. Therefore, the operation is difficult, and the probability of adverse reaction of the internal fixing system is greatly increased. The universal pedicle screw overcomes the defects, and due to the universal characteristic, namely the nail body and the U-shaped groove of the nail cap can rotate three-dimensionally at a certain angle, the combination of the nail and the rod is very easy. The universal pedicle screw used in the prior art has small universal mobility, and when the universal pedicle screw meets the conditions of overlarge bending angle of the spine or other more complicated diseases, the existing universal screw cannot meet the requirements. The design of the large-angle deflection screw in the specific embodiment can be suitable for the complex diseases, the clinical application range is enlarged, and the operation of doctors is convenient.

Nail body

The structure of the nail body 2 is as shown in the figure, the top end of the nail body comprises a bulb 21 which is integrally spherical, and the lower end of the spherical bulb is connected with a screw rod with threads. This configuration is substantially similar to prior art nail bodies.

However, the universal screw cap of the traditional pedicle screw can flexibly move relative to the screw body without any freedom degree limitation, and the design mode brings the defect that a doctor can not well capture the screw cap in the operation process, so that the rod implanting process becomes complicated, the operation time is prolonged, and the bleeding volume of a patient is increased.

To overcome the above-described drawbacks, in the present embodiment, a collar-placing ring groove, i.e., the collar groove 111, is provided in the inner wall of the nut, and the collar 23 is placed in the collar groove 111. As shown in the figure, the inner diameter of the mounted retainer ring is smaller than the outer diameter of the nail body ball head at the height, so that certain extrusion force can be generated on the nail body ball head, and the nail body is ensured to be relatively stable in any direction. The assembly mode not only ensures that the screw and the screw cap are universal and adjustable, expands the functions of the position and the angle of the screw in the operation, but also is beneficial to the convenient and quick rod placement of a doctor in the operation process.

The structure of the clamping ring is as shown in the figure, the clamping ring is of an arc structure and is made of elastic materials, so that when the clamping ring is extruded, the clamping ring can generate certain elastic force and can be matched with the clamping ring groove in the clamping ring groove.

Furthermore, in the present embodiment, as shown in fig. 7 and 8, the lower end of the ball head of the screw body is designed with a ball thread 22, and the inner end surface of the lower portion of the screw cap is also designed with a corresponding ball thread 24 of the screw cap, when the universal screw needs to be converted into a fixing screw, a special instrument can be used to rotate the screw body, so that the ball threads between the two are matched and locked with each other, the anchoring of the screw body and the screw cap is directly realized, the relative freedom between the two is eliminated, and the universal screw is converted into a fixing screw.

In the nail in-process is planted in the operation, the design of hexagonal or interior hexagonal flower shape groove is usually adopted to the cooperation interface of traditional pedicle of vertebral arch screw and apparatus, because supporting apparatus and interior hexagonal or interior hexagonal flower shape groove between inevitable existence clearance, can make like this to take place eccentric rotation at the pedicle of vertebral arch screw of planting the nail in-process, excessively enlarges the internal screw thread track of vertebra, causes the influence to the implantation of pedicle of vertebral arch screw, leads to the screw to become invalid.

The notch of self-centering design can well solve above-mentioned problem, adopts self-centering design can realize accurate positioning, simultaneously because the tapering is very little, utilizes the principle of frictional force, can transmit certain moment of torsion, is enough to satisfy the rotating moment of torsion of screw. And because the taper fit is adopted, the disassembly is convenient. In the certain range of same tapering, the dismouting that the apparatus can be free avoids traditional apparatus to follow closely the problem that the in-process probably blocked with the screw at last, and clinical use is convenient and fast more, accurate.

Check ring

The retainer ring 3 is structurally shown in the figure and comprises a ring body, a groove is formed in the upper portion of the ring body to accommodate a fixing rod, namely a titanium rod 5, and the lower portion of the retainer ring is attached to the outer surface of the ball head, so that the ball head of the nail body is clamped, and the function of fixing the ball head is achieved.

In the prior art, the retainer ring is usually in contact with a titanium rod, and after the titanium rod is pressed by a screw plug, the pressing force is transmitted to the retainer ring, and then the retainer ring is driven to move downwards to press a ball head of a screw, so that a nail body is fixed. But this design is prone to inadequate clamping due to the number of transfer elements.

In the present embodiment, the retainer ring 3 is in contact with the lower surface of the outer plug 41 of the lock plug screw, and directly receives the force from the lock plug screw. Therefore, the retainer ring is arranged in the notch of the screw cap to play a role of limiting the axial movement of the screw body, so that the screw body can rotate freely and cannot be separated from the screw cap.

Locking screw plug

In the present embodiment, the locking plug screw 4 comprises an outer plug screw 41 and an inner plug screw 42, and the outer plug screw is provided with a screw thread at the periphery thereof, and is matched with the screw thread on the inner wall of the nut, so that the outer plug screw can rotate upwards or downwards in the nut under the driving of a rotating force. In this embodiment, the bottom of the external screw plug 41 contacts with the top of the retainer ring 3, and drives the retainer ring to press down, thereby fixing the axial direction of the nail body. The inside through-hole that is provided with of inside and outside plug screw, be provided with the internal thread on the inner wall of through-hole, the internal thread with interior plug screw 42 cooperates. The outer periphery of the inner plug is also provided with an external thread which is engaged with the internal thread of the outer plug to ascend or descend inside the inner plug, and the lower portion of the inner plug is in contact with a fixing rod 5, typically a titanium rod, provided on the retainer ring to press the titanium rod, thereby fixing the titanium rod to the retainer ring.

Further, a locking relationship may be formed between the outer plug and the inner plug, and a typical locking relationship includes that the internal thread of the outer plug is derived only from the upper inner wall of the outer plug so that the inner plug is locked with the outer plug when the inner plug is screwed to the lowermost end of the thread to form an integral body, and the lower end of the inner plug is protruded from the lower end of the outer plug after the inner plug and the outer plug are locked with each other so that the inner plug and the outer plug are formed as an integral body, and the titanium rod is pressed and fastened by the lower end of the inner plug, so that the entire system can be fixed by only one-step locking.

In this way, the screw plug can be locked in two steps or in one step, so that the selection can be carried out according to different functional occasions.

Application method

The multifunctional screw in the embodiment can be used in the following way:

firstly, a clamping ring is arranged in a clamping ring groove of a nail cap, and the purpose of arranging the clamping ring is to prevent a screw nail body from flexibly rotating in the nail cap; because the screw cap and the screw body of the traditional universal screw are connected by a ball-and-socket hinge mechanism, and a gap exists between the ball head and the screw cap of the screw, after the screw is placed into a vertebral body, the screw cap is inclined towards one side under the action of gravity, so that the titanium rod is not conveniently placed; the design of the clamping ring in the specific embodiment can play a certain limiting role on the movement of the screw body, and the screw body and the clamping ring are in transition fit, namely the screw cap can keep static at any position while rotating freely, so that a titanium rod is conveniently placed. Then, the screw body is arranged in the screw cap, and the screw body has a degree of freedom in the screw cap to realize a certain angle of rotation. And finally, the retainer ring is placed in the notch of the screw cap to play a role in limiting the axial movement of the screw body, so that the screw body can rotate freely and cannot be separated from the screw cap.

In this embodiment, the multifunctional screw may be used for various functions, including, but not limited to, a gimbaled screw, a set screw, a high-angle-deflection screw, a reduction screw, and the like, for example.

In the locking mode used as a universal screw: firstly, placing a screw into a vertebral body, and adjusting a screw cap to a proper position; secondly, placing the titanium rod into the mounting groove of the universal screw cap; secondly, the outer screw plug moves downwards to extrude the retainer ring, the retainer ring extrudes the screw body downwards, the screw body extrudes the inner end face of the lower part of the screw cap, the outer screw plug is locked continuously, and the process is strengthened continuously until the screw plug cannot move downwards; finally, the inner screw plug is screwed into the outer screw plug through the threads of the outer screw plug and is continuously screwed into the inner screw plug downwards, the inner screw plug moves downwards to extrude the titanium rod, the titanium rod extrudes the check ring downwards along with the titanium rod, the process is continuously strengthened, all parts are mutually anchored, and the rod and the nail are connected into a firmly fixed whole.

In the locking mode used as a fixing screw: firstly, adjusting a screw cap to a position coaxial with a screw body; secondly, the outer screw plug moves downwards through the internal thread of the screw cap to extrude the retainer ring, the retainer ring extrudes the screw body downwards, the screw body extrudes the inner end face of the lower part of the screw cap, the outer screw plug is locked continuously, the process is strengthened continuously until the screw plug cannot move downwards, and the screw and the outer screw plug are connected into a whole; secondly, placing the titanium rod into the mounting groove of the universal screw cap; finally, the inner screw plug is screwed into the outer screw plug through the threads of the outer screw plug and is continuously screwed into the inner screw plug downwards, the inner screw plug moves downwards to extrude the titanium rod, the titanium rod extrudes the check ring downwards along with the titanium rod, the process is continuously strengthened, all parts are mutually anchored, and the rod and the nail are connected into a firmly fixed whole.

The process of converting a gimbaled screw to a set screw comprises: firstly, aligning the axes of the nail body and the nail head to ensure the coaxiality, and facilitating the threaded matching of the bottom end of the nail head and the bottom end of the ball head; secondly, the nail body is rotated by using an instrument, so that the threads on the nail body and the nail cap are mutually meshed until the nail body cannot move downwards; when the relative freedom degree between the screw cap and the screw body completely disappears, the screw cap and the screw body are mutually anchored, and the whole screw becomes a whole, namely, the function conversion from the universal screw to the fixing screw is realized.

In the specific embodiment, the ball head of the nail body is provided with a centering groove, the centering groove is a cone body with a large upper part and a small lower part, and the cross section of the cone body can be in various shapes which are convenient to match with a centering screwdriver. Because the accurate positioning can be realized by adopting the centrum with a big top and a small bottom, and simultaneously, because the taper is very small, a certain torque can be transmitted by utilizing the principle of friction force, and the requirement of the rotating torque of the screw can be met. In addition, the taper fit is also convenient to disassemble. In the certain range of same tapering, the dismouting that the apparatus can be free avoids traditional apparatus to follow closely the problem that the in-process probably blocked with the screw at last, and clinical use is convenient and fast more, accurate.

In addition, the traditional matching interface of the pedicle screw and the instrument usually adopts an inner hexagonal or inner hexagonal flower-shaped groove design, so that the effect that the instrument is not easy to slip and has enough torsional strength when being matched with the screw is achieved. Pedicle screws are often of a smaller size, resulting in only small internal hexagonal or hexagonal flower shapes. When the screw is used, the torque force of the screw is transmitted along 60 degrees, the fastening torque force is diffused outwards, and loss is generated. Furthermore, when only six corners are in contact with each other and the tightening torque increases, the force concentrates on the corners of the tool, and the hexagonal inner portion of the tool and the screw head may be broken. The special pattern of the screw with the inner hexagonal flower-shaped groove determines that the design can solve the problem of abrasion and slipping of the inner hexagonal wall, but the torque strength of the instrument in the process of rotating the implant nail is smaller than that of the screw with the inner hexagonal flower-shaped groove due to the smaller diameter of the inscribed circle.

In this embodiment, the interface between the screw and the instrument has the advantages of the inner hexagonal spline groove and the inner hexagonal spline groove compared with the conventional inner hexagonal spline groove or inner hexagonal spline groove. The design of the uniformly distributed lug grooves similar to the inner hexagonal flower-shaped grooves can effectively inherit the advantage of wear resistance, and meanwhile, the small lug grooves are combined with the design of large inner diameter, so that the core rod of the instrument has better strength, and the structural strength of the instrument is greatly improved. To sum up, the novel flower groove design integrally improves the service performance of the instrument.

The present invention is not limited to the above-described embodiments or modifications thereof, and various other modifications, changes, and alterations are possible without departing from the main scope and spirit of the present invention.

Claims

1. The multifunctional screw is characterized by comprising a screw cap, a clamping ring, a screw body, a retainer ring and a locking screw plug, wherein

The nail cap is integrally cylindrical, the top of the nail cap is provided with a top opening, and the bottom of the nail cap is provided with a bottom opening; the side wall of the cylindrical nail body is provided with two opposite mounting grooves; internal threads are arranged in the inner wall of the nail cap; a ball socket is arranged on the inner wall of the lower part of the nail cap, a through hole is formed at the bottom end of the ball socket and penetrates through the bottom wall of the nail cap, the cross section of the through hole is integrally circular, and an ear groove is outwards arranged at one circular end; the bottom wall of the nail cap is provided with a bevel, and the through hole 18 is at least partially positioned in the bevel;

the nail comprises a nail body, wherein the top end of the nail body comprises a ball head, the ball head is integrally accommodated in the ball socket in a spherical shape, and the lower end of the ball head is connected with a screw rod with threads; the lower end of the ball head is provided with ball threads, and the inner surface of the lower part of the nail cap is provided with corresponding nail cap ball threads;

the retainer ring comprises a ring body, and a groove is formed in the upper part of the ring body; the lower part of the retainer ring is attached to the outer surface of the ball head; the upper part of the retainer ring is contacted with the lower surface of the locking screw plug;

the locking screw plug comprises an outer screw plug and an inner screw plug, and the periphery of the outer screw plug is provided with threads which are matched with the threads on the inner wall of the screw cap; the bottom of the outer plug screw is in contact with the top of the retainer ring, a through hole is formed in the inner plug screw, an internal thread is formed in the inner wall of the through hole, and the internal thread is matched with the inner plug screw. The periphery of the inner plug screw is also provided with an external thread.

2. The multifunctional screw of claim 1, wherein an attenuation groove is provided on the outer side wall of the screw cap corresponding to the internal thread of the screw cap, the opening of the attenuation groove faces the outer side of the outer side wall, and the groove body is arranged in the thickness direction of the side wall, so that the side wall of the screw cap is attenuated at the grooved place, and the groove bottom of the attenuation groove is in a V shape.