Zero-incisura cervical interbody fusion cage

Abstract

The utility model relates to the technical field of medical instruments, in particular to a zero-incisura cervical interbody fusion cage which comprises a fusion body. The titanium alloy fixing plate is fixedly arranged at the end part of the fusion body; a limiting nail channel is formed in the titanium alloy fixing plate; the titanium alloy screw is a double-pitch screw matched with the limiting screw channel; in addition, the thread pitch of the titanium alloy screw close to the screw head of the titanium alloy screw is smaller than the thread pitch of the titanium alloy screw away from the screw head of the titanium alloy screw, so that the screw is prevented from loosening and sliding in the limiting screw channel. The cervical interbody fusion cage can effectively solve the problems that according to a cervical interbody fusion cage in the prior art, medical staff need to place plates and screws respectively, operation is tedious, and the screws are prone to loosening and shifting due to the fact that the screws are not firmly fixed.

Description

Technical Field

[0001] The utility model relates to the technical field of cervical intervertebral fusion devices, in particular to a zero-profile cervical intervertebral fusion device. Background Art

[0002] Anterior cervical fixation and fusion is a commonly used surgical method for treating cervical degenerative diseases. This type of surgery has low trauma and good results. The main purpose of the surgery is to decompress the nerves and achieve restabilization of the cervical spine. Good and reliable intervertebral fusion is a necessary condition for achieving cervical stability.

[0003] In current clinical practice, intervertebral fusion is usually achieved by implanting an intervertebral fusion device. However, the cervical intervertebral fusion device in the prior art needs to be fixed in combination with a screw plate system. The plate and screw placement operations are cumbersome, and there is a possibility of damage to the surrounding anatomical structures of the cervical spine. There is also a risk of screw loosening and displacement, and a risk of postoperative mechanical complications. Therefore, those skilled in the art are in urgent need of a new cervical intervertebral fusion device to solve the cumbersome plate and screw placement operations of the cervical intervertebral fusion device, as well as the safety hazards of screw loosening and displacement. Utility Model Content

[0004] Therefore, the technical problem to be solved by the present invention is how to solve the problem that the medical staff need to place the plate and the screw separately in the existing cervical intervertebral fusion device, which is cumbersome to operate, and the screws are not firmly fixed, which is easy to loosen and shift. To this end, the present invention provides a zero-notch cervical intervertebral fusion device, including:

[0005] Fusion;

[0006] A titanium alloy fixing plate is fixedly arranged at the end position of the fusion body; a limited position nail channel is provided on the titanium alloy fixing plate;

[0007] The titanium alloy screw is a double-pitch screw adapted to the limiting nail channel; and the thread pitch of the titanium alloy screw near the nail head position is smaller than the thread pitch away from the nail head position, thereby preventing the screw from loosening or slipping in the limiting nail channel.

[0008] Optionally, two groups of the limiting nail channels are provided on the titanium alloy fixing plate;

[0009] The inner inclination angle α of the limiting nail track is 45°±2.5°; the fore-aft inclination angle β of the limiting nail track is 40°±5°.

[0010] Optionally, a tolerance gap is provided between the limiting screw channel and the titanium alloy screw to adjust the screw angle of the titanium alloy screw and increase the shear force between the zero-profile cervical interbody fusion cage and the vertebral body.

[0011] Optionally, the upper and lower surfaces of the zero-profile cervical interbody fusion cage are coated with a hydroxyapatite coating for promoting osteogenesis.

[0012] Optionally, the fusion body is made of polyetheretherketone, a fusion cavity is opened at the center of the fusion body, and the fusion cavity is fixedly connected to the titanium alloy fixing plate.

[0013] Optionally, a bone cement channel is provided in the titanium alloy screw, and a plurality of bone cement through holes for discharging bone cement are also provided in the circumferential direction of the outer peripheral wall of the titanium alloy screw;

[0014] The bone cement is driven to enter the bone cement channel and diffuse into the cancellous bone around the titanium alloy screw through the bone cement through hole to increase the screw holding force.

[0015] Optionally, a hexagonal hole is provided at the tail end of the titanium alloy screw, and the hexagonal hole is communicated with the bone cement channel.

[0016] Optionally, the length of the limiting nail channel is 10 mm to 20 mm to achieve locking and fixation of the titanium alloy screw.

[0017] The technical solution of the utility model has the following advantages:

[0018] 1. The zero-profile cervical intervertebral fusion device provided by the utility model comprises:

[0019] Fusion;

[0020] A titanium alloy fixing plate is fixedly arranged at the end position of the fusion body; a limited position nail channel is provided on the titanium alloy fixing plate;

[0021] The titanium alloy screw is a double-pitch screw adapted to the limiting nail channel; and the thread pitch of the titanium alloy screw near the nail head position is smaller than the thread pitch away from the nail head position, thereby preventing the screw from loosening or slipping in the limiting nail channel.

[0022] In the utility model, the fusion body and the titanium alloy fixing plate are integrated together, thereby avoiding the cumbersome plate and screw placement operations of medical personnel during the operation. In addition, the limit screw channel is set on the titanium alloy fixing plate and fixedly connected with the titanium alloy screw, which can effectively improve the structural strength of the cervical intervertebral fusion cage without affecting the structure of the fusion body.

[0023] In addition, in order to avoid the potential safety hazards of screw loosening and displacement of titanium alloy screws, the titanium alloy screw is designed as a double-pitch screw in the utility model. Because the pitches of the distal and proximal ends of the titanium alloy screws are different, the screws can be prevented from loosening and sliding, and the screws can be accurately screwed into the vertebral body through the pedicles, and the screws can have the best fixing strength in the bone or in the bone with a harder cortical outer area and a softer cancellous inner area, and the screw stress can be decomposed to the greatest extent, and the pull-out resistance can be enhanced, so as to reduce the difficulty of surgical operation and improve the treatment effect.

[0024] 2. The zero-profile cervical intervertebral fusion device provided by the utility model has two groups of the limiting nail channels arranged on the titanium alloy fixation plate; the inner inclination angle of the limiting nail channel α=45°±2.5°; the fore-aft inclination angle of the limiting nail channel β=40°±5°.

[0025] In the utility model, the limiting screw channel of the zero-profile cervical interbody fusion device has an increased screw inclination angle, which can greatly increase the length of the inserted screws, increase the shear force of the fusion device extraction, better achieve cervical spine stability, increase the fusion rate, reduce the risk of screw displacement and loosening, and reduce complications related to internal fixation.

[0026] At the same time, because the limiting screw channel has an increased screw inclination angle, it can effectively reduce the problem of mandibular blocking affecting screw placement during upper cervical spine operations, reduce the situation of sternum blocking screw placement during lower cervical spine operations, expand the operating range of screw placement, and improve the problem of mandibular and sternal blocking the screw placement path and difficulty in screw placement during screw placement in the head and caudal cervical vertebrae, thereby reducing the difficulty of screw placement operations.

[0027] 3. The zero-profile cervical intervertebral fusion device provided by the utility model has a fault-tolerant gap between the limiting screw channel and the titanium alloy screw to adjust the screw angle of the titanium alloy screw and increase the shear force between the zero-profile cervical intervertebral fusion device and the vertebral body.

[0028] In the present invention, a fault tolerance gap is set between the limit screw channel and the titanium alloy screw, and the above-mentioned fault tolerance gap makes the limit screw channel have a certain fault tolerance rate, so as to adjust the screw angle within the preset allowable range, and increase the shear force between the fusion device and the vertebral body to prevent the problem of internal fixation loosening.

[0029] 4. The zero-profile cervical intervertebral fusion device provided by the utility model has a hydroxyapatite coating on the upper and lower surfaces thereof for promoting osteogenesis.

[0030] In the present invention, a hydroxyapatite coating is applied on the surface of the zero-profile cervical intervertebral fusion device. The coating has an osteogenesis effect, helps to improve the success rate of fusion between the intervertebral fusion device and the vertebral bony endplate, and reduces the risk of complications such as postoperative fusion device displacement and fusion failure.

[0031] 5. The zero-profile cervical intervertebral fusion device provided by the utility model has a bone cement channel arranged inside the titanium alloy screw, and a plurality of bone cement through holes for discharging bone cement are also arranged in the circumferential direction of the outer wall of the titanium alloy screw;

[0032] The bone cement is driven to enter the bone cement channel and diffuse into the cancellous bone around the titanium alloy screw through the bone cement through hole to increase the screw holding force.

[0033] In the utility model, a bone cement channel is provided inside the titanium alloy screw, and a bone cement through hole is provided on the outer peripheral wall of the titanium alloy screw. After the operator completes the screw placement work, the bone cement is passed into the bone cement channel, and the bone cement in the bone cement channel diffuses into the cancellous bone around the screw through the bone cement through hole, thereby increasing the screw holding force for osteoporosis patients, preventing the screw from shifting and being pulled out, and reducing the risk of related complications.

[0034] 6. In the zero-profile cervical intervertebral fusion device provided by the utility model, the tail end of the titanium alloy screw is provided with a hexagonal hole, and the hexagonal hole is communicated with the bone cement channel.

[0035] In the utility model, by connecting the hexagonal hole at the tail end of the titanium alloy screw with the bone cement channel, it is possible to achieve a tight connection with the tail end of the titanium alloy screw through the matching bone cement sleeve and the push rod, and then inject bone cement into the titanium alloy screw, and the bone cement enters the bone cement channel at the center of the screw. The bone cement channel is connected to a plurality of bone cement through holes arranged on the peripheral wall of the titanium alloy screw and along its circumferential direction, which can effectively ensure that the bone cement is evenly dispersed inside the vertebral body where the screw is placed.

[0036] 7. The zero-profile cervical intervertebral fusion device provided by the utility model has a length of the limiting screw channel of 8 mm to 20 mm, so as to achieve locking and fixation of the titanium alloy screws, reduce the probability of screw pull-out, and improve the fusion rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A front view of the zero-profile cervical interbody fusion device provided by the utility model;

[0039] Figure 2 A rear view of the zero-profile cervical interbody fusion device provided by the utility model;

[0040] Figure 3 A side view of the zero-profile cervical intervertebral fusion device provided by the utility model;

[0041] Figure 4 A bottom view of the zero-profile cervical intervertebral fusion device provided by the utility model;

[0042] Figure 5 This is a schematic diagram of the longitudinal cross-section structure of the titanium alloy screw provided by the utility model;

[0043] Figure 6 This is a top view of the titanium alloy screw provided by the utility model.

[0044] Description of reference numerals:

[0045] 1-fusion body; 2-titanium alloy fixation plate; 3-limiting screw channel; 4-fusion cavity; 5-titanium alloy screw; 6-bone cement channel; 7-bone cement through hole. DETAILED DESCRIPTION

[0046] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0047] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0048] Example 1

[0049] See also Figure 1 , Figure 2 and Figure 4 , Figure 1 A front view of a zero-profile cervical intervertebral fusion cage in an embodiment of the present invention is shown. Figure 2 A rear view of a zero-profile cervical interbody fusion cage in an embodiment of the present invention is shown. Figure 4 A bottom view of a zero-profile cervical interbody fusion cage in an embodiment of the present invention is shown.

[0050] A zero-profile cervical interbody fusion cage, comprising:

[0051] A fusion body 1, wherein the fusion body 1 is made of polyetheretherketone, a fusion cavity 4 is provided at the center of the fusion body 1, and the fusion cavity 4 is fixedly connected to a titanium alloy fixing plate 2;

[0052] The titanium alloy fixing plate 2 is fixedly arranged at the end position of the fusion body 1; the titanium alloy fixing plate 2 is provided with two groups of the limiting nail channels 3; Figure 1 As shown, the inclination angle of the limiting nail channel 3 is α=45°; Figure 3 As shown, the fore-aft inclination angle β of the limiting nail channel 3 is 40°. In addition, in order to achieve the locking and fixing of the titanium alloy screw 5, the length of the limiting nail channel 3 is set to 15 mm;

[0053] The titanium alloy screw is a double-pitch screw that is compatible with the limiting nail channel 3; and the thread pitch of the titanium alloy screw 5 close to the nail head position of the titanium alloy screw 5 is smaller than the thread pitch away from the nail head position, thereby preventing the screw from loosening or slipping in the limiting nail channel 3.

[0054] In the present application, in order to adjust the screw angle of the titanium alloy screw 5 and increase the shear force between the zero-profile cervical intervertebral fusion device and the vertebral body, a fault-tolerant gap is provided between the limiting screw channel 3 and the titanium alloy screw 5 .

[0055] In this application, in order to improve the success rate of fusion between the intervertebral fusion cage and the vertebral bony endplate and reduce the risk of complications such as postoperative fusion cage displacement and fusion failure, the upper and lower surfaces of the zero-profile cervical intervertebral fusion cage are coated with hydroxyapatite coatings for promoting osteogenesis.

[0056] See also Figure 5 and Figure 6 , Figure 5 A schematic diagram of the longitudinal cross-section structure of a titanium alloy screw in an embodiment of the present invention is shown. Figure 6 A top view of a titanium alloy screw in an embodiment of the present invention is shown.

[0057] A bone cement channel 6 is provided in the titanium alloy screw 5, and a plurality of bone cement through holes 7 for discharging bone cement are also provided in the circumferential direction of the outer wall of the titanium alloy screw 5; the bone cement is driven to enter the bone cement channel 6, and diffuses into the cancellous bone around the titanium alloy screw 5 through the bone cement through holes 7 to increase the screw holding force. In addition, a hexagonal hole is provided at the tail end of the titanium alloy screw 5, and the hexagonal hole is connected to the bone cement channel 6. Through the matching bone cement sleeve and push rod, it is tightly connected to the tail end of the titanium alloy screw 5, and then bone cement is injected into the titanium alloy screw 5, and the bone cement enters the bone cement channel 6 at the center of the screw. The bone cement channel 6 is connected to the plurality of bone cement through holes 7 provided on the circumferential wall of the titanium alloy screw 5 and along its circumferential direction, which can effectively ensure that the bone cement is evenly dispersed inside the vertebral body where the screw is placed.

[0058] Of course, this embodiment does not specifically limit the specific angles of the inclination angle α of the limiting nail channel 3 and the fore-and-aft inclination angle β of the limiting nail channel 3. In other embodiments, the inclination angle α of the limiting nail channel 3 is 41.5° or 47.5°; the fore-and-aft inclination angle β of the limiting nail channel 3 is 35° or 45°.

[0059] Of course, this embodiment does not specifically limit whether a gap is set between the limiting nail channel 3 and the titanium alloy screw 5 and the size of the gap. In other embodiments, the above-mentioned fault-tolerant gap is not set between the limiting nail channel 3 and the titanium alloy screw 5.

[0060] Of course, this embodiment does not specifically limit whether the surface of the zero-profile cervical interbody fusion cage is coated with hydroxyapatite coating. In other embodiments, the upper and lower surfaces of the zero-profile cervical interbody fusion cage are not coated with the above-mentioned hydroxyapatite coating.

[0061] Of course, this embodiment does not specifically limit the length of the limiting nail channel 3. In other embodiments, the length of the limiting nail channel 3 can be 10 mm or 20 mm to achieve locking and fixing of the titanium alloy screw 5.

[0062] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A zero-profile cervical interbody fusion cage, characterized in that: include: Fusion (1); A titanium alloy fixing plate (2) is fixedly arranged at the end position of the fusion body (1); a limited position nail channel (3) is provided on the titanium alloy fixing plate (2); The titanium alloy screw is a double-pitch screw compatible with the limiting nail channel (3); and the thread pitch of the titanium alloy screw (5) close to the nail head position of the titanium alloy screw (5) is smaller than the thread pitch away from the nail head position, thereby preventing the screw from loosening or slipping in the limiting nail channel (3).

2. The zero-profile cervical interbody fusion cage according to claim 1, characterized in that: Two groups of the limiting nail channels (3) are arranged on the titanium alloy fixing plate (2); The inner inclination angle α of the limiting nail path (3) is 45°±2.5°; the fore-aft inclination angle β of the limiting nail path (3) is 40°±5°.

3. The zero-profile cervical interbody fusion cage according to claim 1, characterized in that: A fault-tolerant gap is provided between the limiting screw channel (3) and the titanium alloy screw (5) so as to adjust the screw angle of the titanium alloy screw (5) and increase the shear force between the zero-profile cervical intervertebral fusion device and the vertebral body.

4. The zero-profile cervical interbody fusion cage according to claim 1, characterized in that: The upper and lower surfaces of the zero-profile cervical interbody fusion cage are coated with a hydroxyapatite coating for promoting osteogenesis.

5. The zero-profile cervical interbody fusion cage according to claim 1, characterized in that: The fusion body (1) is made of polyetheretherketone, and a fusion cavity (4) is provided at the center of the fusion body (1), and the fusion cavity (4) is fixedly connected to the titanium alloy fixing plate (2).

6. The zero-profile cervical interbody fusion cage according to claim 1, characterized in that: A bone cement channel (6) is provided in the titanium alloy screw (5), and a plurality of bone cement through holes (7) for discharging bone cement are also provided in the circumferential direction of the outer wall of the titanium alloy screw (5); The bone cement is driven into the bone cement channel (6) and diffuses into the cancellous bone around the titanium alloy screw (5) through the bone cement through hole (7) to increase the screw holding force.

7. The zero-profile cervical interbody fusion cage according to claim 6, characterized in that: The tail end of the titanium alloy screw (5) is provided with a hexagonal hole, and the hexagonal hole is connected to the bone cement channel (6).

8. The zero-profile cervical interbody fusion cage according to claim 1, characterized in that: The length of the limiting nail channel (3) is 10 mm to 20 mm, so as to achieve locking and fixing of the titanium alloy screw (5).

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