Interbody fusion cage with two-way adjustable length and height

Abstract

A guide head and a holding head are arranged at the front end and the rear end of an upper supporting plate and the front end and the rear end of a lower supporting plate respectively, the guide head and the holding head are both in a wedge shape, and the two wedge faces of the guide head and the holding head are in sliding contact fit with the inclined faces of the upper supporting plate and the lower supporting plate respectively. The guiding head and the holding head are driven to be separated and gathered through a thread transmission structure, a nut piece of the thread transmission structure and the guiding head are arranged in a rotation-stopping and movement-stopping mode, a screw piece is matched with the holding head in a rotation-stopping and movement-stopping mode, and the end of a bolt piece is provided with an exposed screwing structure. And a gap which is communicated with the hollow accommodating cavity after the guide head and the holding head are gathered to open the upper supporting plate and the lower supporting plate is formed between the upper supporting plate and the lower supporting plate. An outer frame is not needed, the size is small, lifting can be conducted after implantation, the gap communicated with the hollow containing cavity is formed, the bone can be implanted from the side face after the height is increased, and healing of a diseased part is facilitated.

Description

Technical Field

[0001] The present invention relates to an intervertebral fusion device, and more particularly to an intervertebral fusion device with two-way adjustability of length and height, belonging to a medical device. Background Art

[0002] At present, most conventional thoracolumbar fusion devices are integrated, with anti-slip structures on the upper and lower surfaces, and a cavity in the hollow part for filling bone or artificial bone. During the implantation into the human body, it is necessary to expand the implant channel through bone cutting means such as bone drilling, sawing, and biting. The channel needs to be larger than the cross-section of the fusion device body. Finally, with the help of tools such as a fusion device holding instrument and a bone hammer, the fusion device is violently struck to the working position. Its implantation process is accompanied by huge resistance and impact force, with great resistance during the operation and easy damage to adjacent tissues.

[0003] Therefore, some companies have designed and developed fusion device products with adjustable height. The outer frame of the fusion device itself restricts the upper / lower support plates, and the fusion device is inserted into the working position after being lowered in height by a holding device. For example: A fusion device with adjustable posterior bone grafting height disclosed in the Chinese patent specification with the application number 202111496485.4. This type of fusion device cannot achieve re-bone grafting after implantation and height adjustment; after adjusting the height of the fusion device to the required height through an adjusting device, due to the influence of the outer frame, bone grafting must be carried out through the bone grafting windows on the upper and lower surfaces of the fusion device, and re-bone grafting after implantation and height adjustment cannot be achieved, restricting the growth during the bone recovery process. Moreover, this type of fusion device is restricted by the outer frame, and the length cannot be effectively retracted while the height is adjusted. After implantation, the internal cavity of the fusion device is not easy to fill with bone, which is not conducive to the healing of the diseased part. And because of the existence of the outer frame, the volume of the product is relatively large. Summary of the Invention

[0004] The purpose of the present invention is to provide an intervertebral fusion device with two-way adjustability of length and height, so as to solve the problem in the prior art that re-bone grafting after implantation and height adjustment cannot be achieved, restricting the growth during the bone recovery process.

[0005] In order to solve the above problems, the height-adjustable intervertebral fusion device involved in the present invention adopts the following technical scheme: an intervertebral fusion device with bidirectional adjustable length and height, comprising an upper support plate and a lower support plate that are matched with each other in an upper and lower sliding guide manner, the upper support plate and the lower support plate having a hollow cavity that passes through the upper and lower centers, and the front and rear ends of the upper support plate and the lower support plate are respectively provided with a guide head and a holding head, the guide head and the holding head are both wedge-shaped, the top ends of the guide head and the holding head are opposite, the two wedge surfaces of the guide head and the holding head are respectively in sliding contact with the inclined surfaces of the upper support plate and the lower support plate, and the guide head and the holding head are driven to separate and gather through a threaded transmission structure, the threaded transmission structure comprises a screw member and a nut member that are matched with each other in a threaded manner, the nut member is set to stop rotation and movement with the guide head, the screw member is matched with the holding head for rotation and movement, the end head of the bolt member has an externally exposed screwing structure, and there is a gap between the upper support plate and the lower support plate that is connected to the hollow cavity after the guide head and the holding head are gathered to open the upper support plate and the lower support plate.

[0006] The guide head and the holding head are slidably assembled with the upper support plate and the lower support plate through the cooperation of the dovetail groove and the trapezoidal block, and the two wedge surfaces of the guide head and the holding head are in contact and cooperation with the inclined surfaces of the upper support plate and the lower support plate.

[0007] The upper support plate and the lower support plate are slidably assembled through mutually matching slide bars and slide grooves.

[0008] The upper support plate and the lower support plate have the same structure. The slide bar of the upper support plate is suspended downward in the middle and assembled with the slide groove of the lower support plate, and the slide bar of the lower support plate is suspended upward in the middle and assembled with the slide groove of the upper support plate.

[0009] The nut piece and the screw piece are anti-slipping matched.

[0010] The nut member is integrally arranged with the guide head, and the thread of the nut member is threadedly arranged on the wall of the through hole arranged on the guide head.

[0011] The through hole with internal thread on the guide head is a stepped hole, the internal thread is arranged in the small diameter section of the stepped hole, and the screw rod is matched with the step surface of the stepped hole and the nut to prevent it from falling off through the large diameter shaft ring at the end.

[0012] The fixing sleeve on the screw rod is provided with a limiting sleeve, and the corresponding end of the limiting sleeve is matched with the guide head for limiting.

[0013] The screw rod is matched with the holding head through the nail cap and the limiting sleeve at the end, and the screwing structure is a hexagonal countersunk hole concavely arranged on the nail cap.

[0014] One end of the holding head is pressed on the nail cap of the screw rod, and the other end is pressed on the limiting sleeve through the friction ring.

[0015] The upper support plate and the lower support plate of the present invention are lifted and lowered by gathering and separating the holding head and the guiding head, without the use of an external frame and with a small size. The end of the driving bolt has an exposed screwing structure, so the upper support plate and the lower support plate can be lifted and lowered after being implanted. Moreover, after being lifted, there is a gap between the upper support plate and the lower support plate that is connected to the hollow cavity, so the bone can be implanted from the side after the height is adjusted, which is beneficial to the healing of the diseased part. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the following briefly introduces the drawings required for use in the embodiment: Figure 1 It is a structural schematic diagram of an embodiment of the present invention; Figure 2 for Figure 1 Right view; Figure 3 for Figure 2 AA section view; Figure 4 is a schematic diagram of a three-dimensional structure at the lowest initial height of an embodiment of the present invention; Figure 5 This is a schematic diagram of the three-dimensional structure of the embodiment of the present invention after the highest expansion height; Figure 6 for Figure 1 A schematic diagram of a three-dimensional structure of an upper support plate or a lower support plate in one direction; Figure 7 for Figure 1 A schematic diagram of the three-dimensional structure of the upper support plate or the lower support plate in another direction; Figure 8 for Figure 1 Schematic diagram of the three-dimensional structure of the middle guide head; Figure 9 for Figure 1 Schematic diagram of the three-dimensional structure of the middle handle head.

[0017] Figure 10 for Figure 3 Schematic diagram of the structure of the screw rod.

[0018] Figure 11 for Figure 3 Schematic diagram of the assembly of the middle handle head, screw rod and friction ring. DETAILED DESCRIPTION

[0019] To make the technical objectives, technical solutions, and beneficial effects of the present invention clearer, the technical solutions of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0020] Specific embodiments of the height-adjustable intervertebral fusion device involved in the present invention, in Figures 1 - 9The structure of the upper support plate 1 and the lower support plate 2 is exactly the same. The lower support plate 2 is rotated 180 degrees and buckled with the upper support plate 1. The upper surface of the upper support plate 1 is provided with an anti-slip structure, and the lower surface of the lower support plate 2 is provided with an anti-slip structure. There is a hollow cavity 3 that runs through the upper and lower centers of the upper support plate 1 and the lower support plate 2. It can also be said that there is a large hole in the middle position of the upper and lower support plates. When assembled as a whole, there is a hollow cavity 3. The upper support plate 1 and the lower support plate 2 are matched with the upper and lower sliding guides. The upper support plate 1 and the lower support plate 2 are slidably assembled by the sliding strips 4 and the sliding grooves 5 that cooperate with each other. The middle part of one side of the upper support plate 1 is provided with a sliding strip 4 that overhangs downward, and the other side is provided with a sliding groove 5. The sliding strip 4 of the upper support plate is slidably assembled with the sliding groove 5 of the lower support plate 2. Similarly, the middle part of one side of the lower support plate 2 is provided with a sliding strip 4 that overhangs upward, and the other side is provided with a sliding groove 5. The sliding strip 4 of the lower support plate 2 is slidably assembled with the sliding groove 5 of the upper support plate 1. A guide head 8 and a holding head 9 are respectively provided at the front and rear ends of the upper support plate 1 and the lower support plate 2. The guide head 8 and the holding head 9 are both wedge-shaped, and the top ends of the guide head 8 and the holding head 9 are opposite to each other. The two wedge surfaces of the guide head 8 and the holding head 9 are respectively in sliding contact with the inclined surfaces of the upper support plate 1 and the lower support plate 2. In this way, when the guide head 8 and the holding head 9 are gathered together, the upper and lower support plates will be spread apart. The contact cooperation here is achieved as follows: a first dovetail groove 10 is provided at the lower part of one side of the guide head 8, a second dovetail groove 11 is provided at the upper part of the other side, a first trapezoidal block 12 is convexly provided on the inclined surface of the upper and lower support plates, the first dovetail groove 10 cooperates with the first trapezoidal block 12 of the lower support plate 2, and the second dovetail groove 11 cooperates with the first trapezoidal block 12 of the upper support plate 1, so that the surfaces cannot be separated and are always in contact; similarly, a second trapezoidal block 13 is provided at the middle part of the two wedge surfaces of the holding head 9, and a third dovetail groove 14 is provided at the corresponding position of the upper and lower support plates, and the two second trapezoidal blocks 13 of the holding head are respectively matched with the third dovetail groove 14 of the upper and lower support plates, so that the surfaces cannot be separated and are always in contact. The guide head 8 and the holding head 9 are driven to separate and gather through a threaded transmission structure. In this way, the upper and lower support plates will separate in translation to achieve adjustment in the height direction. When in use, the shape of the bone will not be changed. Moreover, when installed, the upper and lower support plates can be in a gathered state, which is easy to install in the bone. There is no need for strong squeezing, and the damage is small. After installation, the upper and lower support plates can be separated. Adjustment in the length direction is also achieved by gathering and separating the guide head 8 and the holding head 9. After the guide head 8 and the holding head 9 are gathered, the length direction of the entire device is reduced, and the extra space can be used for bone grafting, which is convenient for bone recovery. The size reduction itself is also conducive to the recovery and growth of the bone. The threaded transmission structure here has a screw member 15 and a nut member that are threadedly matched.The nut member is integrally arranged with the guide head 8, and the thread of the nut member is screwed on the wall of the through hole opened on the guide head 8, and the through hole with an internal thread set in the guide head is a stepped hole 16, and the internal thread is set in the small diameter section of the stepped hole 16. The screw member 15 cooperates with the step surface of the stepped hole 16 through the large diameter shaft ring 17 at the end to prevent it from being separated from the nut member, that is, to prevent it from being separated from the guide head. The screw member 15 is matched with the holding head 9 for rotation and displacement, and the assembly relationship between the two is realized as follows: the screw member 15 passes through the through hole on the holding head 9, a limit sleeve 18 is fixedly sleeved on the screw member 15, an arc-shaped groove is opened on the peripheral surface of the screw member 15, and 6 deformation points are provided on the peripheral wall of the limit sleeve 18 corresponding to the arc-shaped groove of the screw member 15, so as to realize the assembly of the two, and a friction ring 6 is also sleeved on the screw member 15, one end of the friction ring 6 is pressed with the limit sleeve 18, and the other end is pressed with the holding head 9, and the holding head 9 is pressed with the nail cap 7 on the end of the screw member 15, so as to realize the rotation and displacement of the screw member 15 and the holding head 9. A concave-convex structure 20 is provided on the end face where the nail cap 7 and the holding head are matched, so as to increase friction and prevent the thread from loosening. At the same time, the corresponding end of the limit sleeve 18 is limitedly matched with the guide head to prevent the guide head and the holding head from being too close. The hexagonal countersunk hole 19 is concavely arranged on the nail cap 7 of the screw rod, and the hexagonal countersunk hole 19 is a screwing structure and is exposed on the outside.

[0021] After the guiding head and the holding head are gathered together to spread the upper support plate and the lower support plate apart, the upper support plate 1 and the lower support plate 2 move away from each other up and down, with a gap therebetween that is connected to the hollow cavity 3 of the two, and bone grafting can be performed through the gap.

[0022] The screw member in the above embodiment is prevented from shifting with the holding head through the nail cap, the limiting sleeve and the friction ring at the end. In other embodiments, the prevented from shifting can also be achieved through other structures.

[0023] The nut member in the above embodiment is integrally provided with the guide head to achieve non-slip and non-rotational cooperation between the two. In other embodiments, this can also be achieved through other assembly structures.

[0024] The knob structure in the above embodiment is a concave hexagonal countersunk hole arranged on the nail cap. In other embodiments, it can also be a screwing structure of other structural forms, such as a slotted hole or a cross hole.

[0025] The guide head and the holding head in the above-mentioned embodiment are slidably assembled with the upper support plate and the lower support plate through the cooperation of the dovetail groove and the trapezoidal block, and the two wedge surfaces of the guide head and the holding head are in contact and cooperation with the inclined surfaces of the upper support plate and the lower support plate. In other embodiments, the contact and cooperation of the wedge surface and the inclined surface can also be maintained by other limiting structures, for example: a tension spring is set between the upper and lower support plates.

[0026] One end of the gripping head in the above embodiments presses against the nail cap of the screw member, and the other end presses against the limiting sleeve through the friction ring. In other embodiments, the gripping head can also directly press against the limiting sleeve.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Any equivalent replacement of the present invention and modifications or partial replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. An intervertebral fusion cage with adjustable length and height, comprising an upper support plate and a lower support plate that slide and guide upward and downward, wherein the upper support plate and the lower support plate have a hollow cavity that passes through the center of the upper support plate and the lower support plate, characterized in that: A guiding head and a holding head are respectively provided at the front and rear ends of the upper support plate and the lower support plate, and the guiding head and the holding head are both wedge-shaped, and the top ends of the guiding head and the holding head are opposite to each other, and the two wedge surfaces of the guiding head and the holding head are respectively in sliding contact with the inclined surfaces of the upper support plate and the lower support plate, and the guiding head and the holding head are driven to separate and gather through a threaded transmission structure, and the threaded transmission structure includes a screw member and a nut member with threaded matching, and the nut member is arranged to stop rotation and movement with the guiding head, and the screw member is matched with the holding head for rotation and movement, and the end head of the bolt member has an exposed screwing structure, and there is a gap between the upper support plate and the lower support plate that is connected to the hollow cavity after the guiding head and the holding head are gathered to spread the upper support plate and the lower support plate apart.

2. The height-adjustable intervertebral fusion cage according to claim 1, characterized in that: The guide head and the holding head are slidably assembled with the upper support plate and the lower support plate through the cooperation of the dovetail groove and the trapezoidal block, and the two wedge surfaces of the guide head and the holding head are in contact and cooperation with the inclined surfaces of the upper support plate and the lower support plate.

3. The height-adjustable intervertebral fusion cage according to claim 2, characterized in that: The upper support plate and the lower support plate are slidably assembled through mutually matching slide bars and slide grooves.

4. The height-adjustable intervertebral fusion cage according to claim 3, characterized in that: The upper support plate and the lower support plate have the same structure. The slide bar of the upper support plate is suspended downward in the middle and assembled with the slide groove of the lower support plate, and the slide bar of the lower support plate is suspended upward in the middle and assembled with the slide groove of the upper support plate.

5. The height-adjustable intervertebral fusion cage according to any one of claims 1 to 4, characterized in that: The nut piece and the screw rod piece are anti-slipping matched.

6. The height-adjustable intervertebral fusion cage according to claim 5, characterized in that: The nut member is integrally arranged with the guide head, and the thread of the nut member is threadedly arranged on the wall of the through hole arranged on the guide head.

7. The height-adjustable intervertebral fusion cage according to claim 6, characterized in that: The through hole with internal thread on the guide head is a stepped hole, the internal thread is arranged in the small diameter section of the stepped hole, and the screw rod is matched with the step surface of the stepped hole and the nut to prevent it from falling off through the large diameter shaft ring at the end.

8. The height-adjustable intervertebral fusion cage according to claim 7, characterized in that: The fixing sleeve on the screw rod is provided with a limiting sleeve, and the corresponding end of the limiting sleeve is matched with the guide head for limiting.

9. The height-adjustable intervertebral fusion cage according to claim 8, characterized in that: The screw rod is matched with the holding head through the nail cap and the limiting sleeve at the end, and the screwing structure is a hexagonal countersunk hole concavely arranged on the nail cap.

10. The height-adjustable intervertebral fusion cage according to claim 9, characterized in that: One end of the holding head is pressed on the nail cap of the screw rod, and the other end is pressed on the limiting sleeve through the friction ring.

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