CN213788020U

CN213788020U - Fusion cage for minimally invasive spine surgery

Info

Publication number: CN213788020U
Application number: CN202021756154.0U
Authority: CN
Inventors: 宋兴华; 陈玉兵; 丁俐文
Original assignee: Jinan University
Current assignee: Jinan University; University of Jinan
Priority date: 2020-08-20
Filing date: 2020-08-20
Publication date: 2021-07-27
Anticipated expiration: 2030-08-20

Abstract

The utility model discloses a fusion cage for minimally invasive spine surgery, which comprises a fusion cage body, a steel plate, fusion cage locking screws, steel plate locking screws and connecting screws; the axes of the fusion cage locking screws, the axes of the steel plate locking screws and the axis of the fusion cage body are all provided with a certain included angle, the two fusion cage locking screws are not on the same plane, are arranged in the fusion cage body in a crossed manner and are respectively fixed on the opposite cortex; and each fusion cage locking screw and the fusion cage body are locked at two positions, so that the longitudinal pressure resistance of the fusion cage is enhanced. The steel plate can rotate relative to the fusion cage body, and the long axis of the steel plate does not exceed the length of the diagonal line of the rear end face of the fusion cage body; the three-dimensional space structure of screw anchoring at different angles in the intervertebral space and double-cortical screw fixing at the side of the vertebral body is completed by the arrangement of the locking screws of the fusion cage and the assistance of the steel plate, so that the implantation of the fusion cage is completed in the channel at one time, and a stable fixing result is achieved.

Description

Fusion cage for minimally invasive spine surgery

Technical Field

The utility model relates to the technical field of medical prosthesis, in particular to a fusion cage for minimally invasive spine surgery.

Background

With the improvement of medical instruments, the spinal minimally invasive surgery industry is developed vigorously, and open spinal fusion surgery with large trauma is needed in the past, and most of the spinal minimally invasive surgery can be completed under a passage in a minimally invasive way. For spinal fusion, how to improve the fusion rate is always a matter of concern.

In clinical work, when lumbar vertebral bodies are unstable and slip, fusion and fixation between the vertebral bodies are needed. The traditional method has the advantages of incision fusion and fixation of a posterior path, a lateral path and an anterior path, large surgical trauma, much bleeding and long time for a patient to lie in bed after surgery. With the improvement of minimally invasive techniques, the decompression and fusion under channel minimally invasive has been fully possible, but often requires percutaneous fixation of additional incisions, which prolongs the operation time. The prior art at present has the following defects:

(1) the spinal endoscopic surgery can complete the discectomy under the spinal endoscopic surgery, the release and decompression of nerve roots and the implantation of an interbody fusion cage, but can not complete the fixation under the same minimally invasive incision.

(2) Operations such as XLIF and OLIF (minimally invasive interbody fusion technique on the right side and the front side) can complete small incisions (about 3-5cm) on the right side and the front side and complete the implantation of the fusion device and the fixation on the lateral side of the vertebral body, but the fixation of the fusion device and a nail rod or a nail plate on the lateral side of the vertebral body are two independent parts, so that the stability and the strength are deficient, and the incision is larger.

(3) When using 2 screws to fix in the fusion cage among the prior art, because the nail tail direct fixation is internal in the vertebra, according to lever principle, the activity degree between the lumbar vertebrae centrum inevitably leads to the huge shearing force of nail pole and nail tail, leads to the fracture, perhaps the screw is not hard up in the centrum, leads to the operation failure.

(4) The fusion cage in the prior art is lack of auxiliary steel plate fixation which is integrated, so that the fixation screw of the fusion cage is easy to withdraw, and the fixation screw is difficult to complete in a minimally invasive incision channel.

Therefore, how to accomplish both decompression and fusion and stable fixation in the passage of a minimally invasive incision is a core problem faced by the prior art.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems existing in the prior art, the utility model provides an interbody fusion cage which is convenient for implantation, fusion, fixation and good stability, which is convenient for, the utility model provides the following technical scheme:

a fusion cage for minimally invasive spine surgery comprises a fusion cage body, a steel plate, two fusion cage locking screws, two steel plate locking screws and a connecting screw for connecting the fusion cage body and the steel plate together; the fusion cage body is a hollow cavity with a conical front end and a cuboid-shaped rear end, a plurality of bone grafting windows are arranged on the side face of the hollow cavity, the conical front end is convenient to load from an operation channel, a central hole is formed in the center of the rear end face, two first fusion cage locking screw holes are symmetrically formed in two sides of the central hole and two corners of the rear end face, and each fusion cage locking screw penetrates through the corresponding first fusion cage locking screw hole and is fixed to the cortex of the vertebral body. The steel plate covers the outside of the rear end face of the fusion cage body and is rectangular, a central hole is also formed in the steel plate, and two steel plate locking screw holes are symmetrically formed in the two sides of the central hole and close to the short edge of the rectangular steel plate; each steel plate locking screw penetrates through the corresponding steel plate locking screw hole and is fixed on the cortical bone of the vertebral body. The fusion cage locking screw and the steel plate locking screw are self-tapping screws and are not on the same plane. The connecting screw connects the cage body and the steel plate together at the central hole.

Because the two fusion cage locking screws are respectively fixed on the centrum cortex, the fusion cage body is pulled towards the intervertebral spaces in different directions, and the fusion cage body is prevented from moving outwards; the steel plate is fixed on the fusion cage body through the central hole, has the function of blocking the fusion cage body from further moving towards the centrum gap, and the connecting screw between the fusion cage body and the steel plate has the function of pulling the fusion cage body outwards; the two steel plate locking screws are fixed on the cortex on both sides of the vertebral body, have high strength, are not in the same plane with the fusion cage locking screws, and limit the mobility of the upper vertebral body and the lower vertebral body through the steel plates. A three-dimensional space structure with the anchoring in the intervertebral space and the double-cortical fixation of the upper and lower centrum is formed. In addition, the steel plate covers the outer side of the locking screw of the fusion cage, and can also prevent the nail from backing.

Further, two pieces of integration ware locking screw also are not in the coplanar, and two pieces of integration ware locking screw axes and integration ware body axis contained angle are the acute angle, and this preferred angle is 20 degrees, when twisting into integration ware locking screw, can realize through the luffing motion of work sleeve, when the ilium position was too high to block, can twist through universal screw.

Furthermore, in order to improve the fixing effect of the fusion device locking screws, the two fusion device locking screws respectively penetrate out of the corresponding first fusion device locking screw holes and are inserted into the opposite cortex in a crossed manner to be fixed, so that crossed fixation is formed, and the fixing effect is better.

Furthermore, in four side surfaces of the cuboid structure at the rear end of the fusion cage body, two side surfaces in contact with the upper vertebral body and the lower vertebral body are in a first preset direction, and the other two opposite side surfaces are in a second preset direction. Two second fusion device locking screw holes are respectively arranged on two side surfaces in the first preset direction; and each fusion device locking screw sequentially passes through the first fusion device locking screw hole and the second fusion device locking screw hole, and is finally respectively inserted into the cortex on the opposite side for fixation. In this state, each fusion cage locking screw and the fusion cage body are locked at two positions, and the functions of supporting and fixing and increasing the pressure resistance can be achieved.

Furthermore, in order to facilitate the fusion cage to be arranged in the operation channel, the rear end face of the fusion cage body can be designed to be square, the end face of the steel plate is designed to be rectangular, and circular arcs are arranged at each corner; in addition, the steel plate can rotate relative to the fusion cage body, and the long axis of the steel plate does not exceed the diagonal line of the rear end face of the fusion cage body; set up the notch near two opposite side midpoints at the fuse ware body rear end face, the purpose of design like this, at the initial state that the operation passageway was packed into to the fuse ware, the steel sheet major axis is rotatory to fuse ware body rear end face diagonal direction, whole fuse ware includes that fuse ware body and steel sheet just can penetrate the operation passageway integratively, after penetrating the operation passageway, before the fixed steel sheet locking screw, need to turn 45 degrees with the relative fuse ware body of steel sheet, the steel sheet major axis is grown out fuse ware body rear end face this moment, there is steel sheet locking screw at the position of growing out, because the notch has been established near two opposite side midpoints at the rear end face of fuse ware body again, so steel sheet locking screw just can be fixed in the offside cortex through this notch.

Furthermore, bone grafting windows can be arranged on four side surfaces of the fusion cage body, for example, two bone grafting windows are respectively arranged on two side surfaces in the first preset direction, two bone grafting windows are respectively arranged on two side surfaces in the second preset direction, the bone grafting windows on the four side surfaces are internally communicated to form bone grafting spaces, and the bone grafting spaces are not only communicated with the upper vertebral body and the lower vertebral body, but also communicated with the side surfaces, so that the growth of blood circulation can be increased, and the fusion rate is increased.

Furthermore, in order to prevent the fusion cage from moving and separating towards the opening direction of the operation wound after being installed, the side surface of the fusion cage body is also provided with an anti-slip part, the anti-slip part is a plurality of bulges inclining towards the rear end of the fusion cage body, and the inclining direction can avoid that the bulges and the vertebral endplate tissues generate overlarge friction to cause secondary injury to the human body when the fusion cage is installed. Preferably, the anti-slip parts may be provided on both side surfaces of the fusion cage body corresponding to the first preset direction.

Furthermore, the included angle between the axis of the two steel plate locking screws and the axis of the fusion device body is an acute angle, and the preferred angle is 20 degrees.

To sum up, the utility model discloses mainly there is following outstanding beneficial effect:

1. this patent has adopted and has set up the steel sheet outside fusing the ware body, and the steel sheet passes through steel sheet locking screw, fuses the ware body through fusing ware locking screw, follows different angles respectively, fixes on the centrum cortex on different planes, has formed the solid space structure that the inside anchoring of intervertebral space, the two cortex of upper and lower centrum are fixed for stability and intensity improve greatly.

2. In this patent, every piece of integration ware locking screw has two lockings with the integration ware body for holding power between integration ware locking screw and the integration ware increases, has improved the vertical compressive capacity that fuses the ware, and stability is better.

3. This patent covers the steel sheet in the fusion cage locking screw outside, not only can accomplish the operation in a minimal access incision passageway, has still played and has avoided the fusion cage locking screw to appear moving back the problem of nail.

4. The steel plate and the special design of the shape and the structure of the rear end face of the fusion cage body and the two can rotate by 45 degrees relatively, so that the steel plate and the fusion cage can pass through the working sleeve simultaneously, and the working channel cannot be excessively increased.

5. The anti-slip part which inclines towards the rear end of the fusion body is arranged on the side face of the fusion device body, so that the situation that when the fusion device is installed, the secondary injury to a human body is caused by overlarge friction generated between the convex anti-slip part and a vertebral endplate tissue can be avoided, and the fusion device can be effectively prevented from moving and breaking away from the opening direction of an operation wound after the fusion device is installed.

6. All bone grafting windows are communicated inside the fusion cage. Therefore, the bone grafting in the fusion cage can be ensured to be contacted with the upper surface and the lower surface of the vertebral body and the side surface of the fusion cage to the maximum extent, which is beneficial to the growth of blood circulation and promotes the fusion of bones.

Drawings

Fig. 1 is a schematic perspective view of a normal working state of a fusion cage for minimally invasive spine surgery according to an embodiment of the present invention.

Fig. 2 is a rear view of the normal working state of the fusion cage for minimally invasive spine surgery according to the embodiment of the present invention.

Fig. 3a is a side view of a fusion cage body according to an embodiment of the present invention in a first predetermined direction.

Fig. 3b is a side view of a second preset orientation of the fusion cage body according to an embodiment of the present invention.

Fig. 4 is an assembly view (first preset orientation) of the cage body and cage locking screw according to an embodiment of the present invention.

Fig. 5a is a view showing the mutual positions of the rear end face and the steel plate of the fusion cage body according to the embodiment of the present invention. (in this case, the long end of the steel plate is in the same direction as the diagonal of the rear end face of the fusion cage body)

Fig. 5b is a view showing the mutual positions of the rear end face and the steel plate of the fusion cage body according to the embodiment of the present invention. (position diagram when the Steel plate is rotated 45 degrees)

Fig. 6 is a schematic view of the operation state of the embodiment of the present invention.

Fig. 7 is a schematic diagram illustrating an embodiment of the present invention.

In the figure:

1 is a fusion cage body, 11 is a first fusion cage locking screw hole, 12 is a second fusion cage locking screw hole, 13 is a bone grafting window, 14 is an anti-skid part, and 15 is a notch; 2 is a steel plate, 21 is a steel plate locking screw hole; 3 is a fusion cage locking screw; 4 is a steel plate locking screw; 5 is a connecting screw; 6 is an operation channel; and 7 is a vertebral cone.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Fig. 1 to 2 are schematic perspective views of the embodiment of the present invention viewed from different directions in a normal operating state. The fusion cage for minimally invasive spine surgery comprises a fusion cage body 1, a steel plate 2, two fusion cage locking screws 3, two steel plate locking screws 4 and a connecting screw 5 which connects the fusion cage body and the steel plate together and is positioned in the center of the steel plate;

fuse ware body 1 is the cavity that the cone is, the rear end is the cuboid structure for a front end, and what fuse ware body 1's front end is the toper and is convenient for pack into from the operation passageway, is equipped with central hole on the rear end face, sets up two first fusion ware locking screw holes 11 in central hole bilateral symmetry, and every piece of fusion ware locking screw 3 passes every first fusion ware locking screw hole 11 that corresponds, and cross fixation is in offside centrum cortex of bone. The rear end surface of the fusion cage body 1 is covered with a rectangular steel plate 2, the middle of the steel plate is also provided with a central hole, and two sides of the central hole are symmetrically provided with two steel plate locking screw holes 21; each steel plate locking screw 4 passes through the corresponding steel plate locking screw hole 21 and is also fixed to the cortical bone of the vertebral body. The fusion cage locking screw 3 and the steel plate locking screw 4 are self-tapping screws and are not in the same plane. The connecting screw 5 respectively passes through the central holes of the fusion device body 1 and the steel plate 2 to connect the two together.

The fusion cage body 1 is provided with four side surfaces, one group of side surfaces which are respectively contacted with the upper vertebral body and the lower vertebral body are called a first preset direction, see fig. 3a, the other group of side surfaces are called a second preset direction, see fig. 3b, each side surface in the first preset direction is respectively provided with one bone grafting window 13, and each side surface in the second preset direction is respectively provided with two bone grafting windows 13; because the fusion cage body 1 is hollow, all the bone grafting windows 13 are communicated to form a bone grafting space, the upper part, the lower part, the left part and the right part of the bone grafting space can be communicated with the vertebral body, the growth of blood circulation is increased, and the fusion rate is improved.

As shown in fig. 1 and 4, the two fusion cage locking screws 3 are not on the same plane, and each fusion cage locking screw 3 passes through the first fusion cage locking hole 11 of the fusion cage body 1 and then is obliquely inserted into the opposite cortex, so that the two fusion cage locking screws 3 are crossed in space (i.e. the axes of the two fusion cage locking screws are out of plane), and a better fixing effect is achieved. In addition, the axis of each cage locking screw and the axis of the cage body are at an acute angle, preferably 20 degrees. Select suitable angle, could guarantee when screwing in fusion cage locking screw 3, can realize through the luffing motion of work sleeve, when the ilium position was too high to have the hindrance, can screw in through universal screw. As shown in fig. 6, the surgical tunnel 6 can be swung between the upper and lower phantom positions in the drawing to screw in the cage lock screw 3 at different angles.

Two second fusion device locking screw holes 11 are respectively arranged on two side surfaces of the fusion device body 1 in the first preset direction; each fusion cage locking screw 3 sequentially passes through the first fusion cage locking screw hole 11 and the second fusion cage locking screw hole 12, and is finally respectively inserted into the opposite cortex for fixation, see fig. 4, in this state, each fusion cage locking screw 3 and the fusion cage body 1 are locked at two positions, and the functions of supporting and fixing and increasing the pressure resistance can be achieved.

In order to facilitate the fusion cage to be arranged in an operation channel, the rear end face of the fusion cage body 1 can be designed to be square, the steel plate 2 can be designed to be rectangular, and each corner position of the steel plate 2 is provided with an arc; in addition, a rotatable connecting screw 5 is arranged between the steel plate and the fusion cage body, so that the steel plate 2 can rotate relative to the fusion cage body 1, and the long axis of the steel plate does not exceed the diagonal line of the rear end face of the fusion cage body; notches 15 are arranged near the middle points of two opposite edges of the rear end surface of the fusion cage body 1. Referring to fig. 5a and 5b, in the initial state when the fusion cage enters the predetermined position from the operation channel, the long axis of the steel plate 2 rotates to be consistent with the diagonal line of the rear end face of the fusion cage body 1, the whole fusion cage including the fusion cage body 1 and the steel plate 2 can be integrally inserted into the operation channel, after the insertion into the operation channel, the steel plate 2 is rotated by 45 degrees relative to the fusion cage body 1, as shown in fig. 5b, the steel plate 2 is longer than the rear end face of the fusion cage body 1, and at the extended position, the steel plate locking screw 4 passes through the notch 15 position and is fixed on the contralateral cortex.

Fig. 7 illustrates the reason why the cross section of the working channel is greatly reduced by providing arcs at four angular positions on the rear end surface of the cage body 1. If there is no arc, the rear end face of the fusion cage body 1 is a square abcd, and the diagonal line thereof is a dotted line ac, at this time, the cross section of the working channel needs to be not smaller than a circle (a dotted line large circle in the drawing) having the dotted line ac as a diameter, and after arcs are provided at four corners of the rear end face of the fusion cage body, the cross section of the working channel needs to be not smaller than a small circle (a solid line small circle in the drawing) having the dotted line ef as a diameter. Therefore, the cross section of the working channel is reduced, the injury to a patient is reduced, and the recovery is easier.

Similarly, it is also effective to design arcs at the four corners of the steel plate 2 (see fig. 5a), and in fig. 5a, it is an optimal choice when two sets of short sides of the steel plate 2 form an approximate semicircle.

In addition, in order to prevent the fusion cage from moving and separating towards the opening direction of the operation wound after being installed, the side surface of the fusion cage body 1 is also provided with an anti-slip part 14, the anti-slip part is a plurality of bulges inclining towards the rear end of the fusion cage body 1, and the inclining direction of the bulges can avoid the secondary damage to the human body caused by overlarge friction generated between the anti-slip part and the tissue of the vertebral end plate when the fusion cage is installed. Preferably, the anti-slip parts 14 may be provided on both sides of the cage body corresponding to the first preset direction (see fig. 3a and 3 b).

The above-mentioned embodiments are only for the convenience of explanation and illustration of the preferred embodiments of the present invention, and in fact, the embodiments of the present invention have many different forms and combinations, which are not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents and all fall within the protection scope of the present invention.

Claims

1. A fusion cage for minimally invasive spine surgery is characterized by comprising a fusion cage body (1), a steel plate (2), two fusion cage locking screws (3), two steel plate locking screws (4) and a connecting screw (5);

the fusion cage body (1) is a hollow cavity with a conical front end and a cuboid rear end, a plurality of bone grafting windows (13) are arranged on the side surface, a central hole is formed in the center of the rear end surface of the fusion cage body (1), two first fusion cage locking screw holes (11) are formed in two symmetrical corners, and each fusion cage locking screw (3) is inserted into the corresponding first fusion cage locking screw hole (11);

the steel plate (2) is rectangular and covers the rear end surface of the fusion device body (1), a central hole is also formed in the center of the steel plate, and two steel plate locking screw holes (21) are symmetrically formed in the positions close to the short edges of the steel plate; each steel plate locking screw (4) is inserted into the corresponding steel plate locking screw hole (21);

the fusion cage locking screw (3) and the steel plate locking screw (4) are self-tapping screws, and the axes of the self-tapping screws and the steel plate locking screws are not on the same plane; the connecting screw (5) penetrates through central holes in the fusion cage body (1) and the steel plate (2) to connect the fusion cage body and the steel plate.

2. The fusion cage for minimally invasive spine surgery according to claim 1, characterized in that the axes of the two fusion cage locking screws (3) are not in the same plane, and the included angle between the axis of each fusion cage locking screw (3) and the axis of the fusion cage body (1) is acute.

3. Cage for minimally invasive spine surgery according to claim 2, characterized in that the axis of each cage locking screw (3) and the axis of the cage body (1) are at an angle of 20 degrees.

4. A cage for minimally invasive spine surgery according to claim 2 or 3, characterized in that the two cage locking screws (3) are fixed crosswise.

5. The fusion cage for minimally invasive spine surgery according to claim 4, characterized in that the rear end of the cage body (1) is of a rectangular parallelepiped structure, two opposite sides of which are in a first preset direction, and the other two opposite sides of which are in a second preset direction; two second fusion device locking screw holes (12) are respectively arranged on two side surfaces of the fusion device body (1) in a first preset direction; each fusion device locking screw (3) sequentially penetrates through the first fusion device locking screw hole (11) and the second fusion device locking screw hole (12).

6. The cage for minimally invasive spine surgery as recited in claim 5, characterized in that the rear end face of the cage body (1) is square, the end face of the steel plate is rectangular, and four corners of the square and the rectangle are provided with circular arcs; the steel plate (2) is rotatably connected to the rear end face of the fusion device body (1), the long axis of the steel plate is not more than the diagonal length of the end face of the fusion device body, and notches (15) are arranged on the rear end face of the fusion device body and in contact with two steel plate locking screws (4).

7. The fusion cage for minimally invasive spine surgery according to claim 5 or 6, characterized in that one bone grafting window (13) is respectively arranged on two sides of the first preset direction and beside the second fusion cage locking screw hole (12) in four sides of the fusion cage body (1), two bone grafting windows (13) are respectively arranged on two sides of the second preset direction, and the bone grafting windows (13) on the four sides are internally communicated.

8. The fusion cage for minimally invasive spine surgery according to claim 7, characterized in that the fusion cage body (1) is further provided with anti-slip parts (14) at the sides, and the anti-slip parts are a plurality of protrusions inclined towards the rear end of the fusion cage body (1).

9. Cage for minimally invasive spine surgery according to claim 8, characterized in that said anti-slip means (14) are provided on two sides of the cage body (1) corresponding to a first preset direction.

10. Cage for minimally invasive spine surgery according to any of claims 1, 2, 3, 5, 6, 8 and 9, characterized in that the axis of the steel plate locking screw (4) and the axis of the cage body (1) are at an angle of 20 degrees.