An angle that can open the interbody fusion device

Abstract

This invention discloses an angle-expandable intervertebral fusion device, comprising: a first support plate for supporting a first part of the vertebral body; a second support plate for supporting a second part of the vertebral body; a proximal wedge located between the first and second support plates, with the proximal ends of the first and second support plates respectively rotatably connected to the proximal wedge; a distal wedge located between the first and second support plates, slidably connected to the first and second support plates; and a drive mechanism, the distal end of which is located within the distal wedge, and the proximal end of which is rotatably connected to the proximal wedge. The fusion device of this invention has a very small initial volume, allowing for easy implantation into the diseased intervertebral space, reducing damage to the vertebral structure and soft tissues, and eliminating the need for excessive expansion of adjacent vertebral height. After implantation into the intervertebral space, the distal end of the drive fusion device is gradually expanded until the patient's lumbar spine conforms to the physiological curve of the human body.

Description

Technical Field

[0001] This invention belongs to the field of spinal implant technology, and particularly relates to an interbody fusion device with an angle-expandable design. Background Technology

[0002] In orthopedic clinics, spinal degeneration is common, including intervertebral disc degeneration, spinal stenosis, spondylolisthesis, and compression of the spinal cord or nerve roots. Surgical treatment is often required to completely relieve the compression, restore the physiological curvature of the spine, and ensure spinal stability.

[0003] Spinal fusion is a basic technique for treating the above-mentioned spinal diseases, used to establish and maintain spinal stability. Interbody fusion is the ideal procedure in spinal fusion that conforms to spinal biomechanics, and the fusion device is a commonly used instrument in interbody fusion.

[0004] With the development of minimally invasive surgical techniques, traditional intervertebral fusion cages can no longer meet the needs of minimally invasive surgery. Establishing a working channel through a minimally invasive approach, and achieving a fusion rate no lower than that of open surgery while minimizing damage to surrounding tissues, is the premise of minimally invasive intervertebral fusion. Because the intervertebral angle between L4 and L5, and between L5 and the sacrum, is between 10° and 20°, surgeons may not know the precise height of the fusion cage required during the procedure. Surgeons need to repeatedly try inserting the cage into the intervertebral space, and may also need to stretch the adjacent vertebrae too much, leading to muscle and nerve strain during the operation, and consequently, postoperative lumbar muscle pain and functional impairment. Summary of the Invention

[0005] The purpose of this invention is to provide an angle-expandable intervertebral fusion device with a small initial volume, which can be easily implanted into the diseased intervertebral space, reducing damage to the vertebral bone structure and soft tissue, without excessively expanding the height of adjacent vertebrae, and after implantation into the intervertebral space, driving the distal end of the fusion device to gradually expand until the patient's lumbar spine conforms to the curvature of the human body.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] An angle-openable interbody fusion device includes:

[0008] The first support plate is used to support the first part of the vertebral body;

[0009] The second support plate is used to support the second part of the vertebral body;

[0010] A proximal wedge is located between the first support plate and the second support plate, and the proximal ends of the first support plate and the second support plate are respectively rotatably connected to the proximal wedge.

[0011] A distal wedge is located between the first support plate and the second support plate, and the distal wedge is slidably connected to the first support plate and the second support plate;

[0012] A drive mechanism, wherein the distal end of the drive mechanism is located within the distal wedge, and the proximal end is rotatably connected to the proximal wedge;

[0013] An external tool rotates the drive mechanism, which drives the distal wedge to move along the axial direction of the drive mechanism. The distal wedge opens or closes the distal ends of the first and second support plates.

[0014] When the distal wedge moves between the first support plate and the second support plate, the distal wedge can rotate.

[0015] The distal wedge includes a first distal wedge and a second distal wedge, which are rotatably connected.

[0016] When the distal wedge moves along the axial direction of the drive mechanism, the first distal wedge and the second distal wedge rotate relative to each other.

[0017] The first distal wedge and the second distal wedge are rotatably connected by a first pin.

[0018] A first driving inclined surface is provided on the first distal wedge, and a second driving inclined surface is provided on the second distal wedge. The first driving inclined surface slides in cooperation with the first inclined surface of the first support plate, and the second driving inclined surface slides in cooperation with the second inclined surface of the second support plate.

[0019] A first guide block is provided on the first driving inclined surface, and a second guide block is provided on the second driving inclined surface. The first support plate has a first guide groove that slides with the first guide block, and the second support plate has a second guide groove that slides with the second guide block; or

[0020] The first driving inclined surface is provided with a first guide groove, the second driving inclined surface is provided with a second guide groove, the first support plate is provided with a first guide block that slides in cooperation with the first guide groove, and the second support plate is provided with a second guide block that slides in cooperation with the second guide groove.

[0021] At least one of the first support plate and the second support plate has a sidewall that extends toward the other support plate to form a guide portion. At least one of the first support plate and the second support plate has a third guide groove on its sidewall, and the guide portion slides in conjunction with the third guide groove.

[0022] The first support plate has guide portions on both sides, and the second support plate has third guide grooves on both sides that slide in cooperation with the guide portions of the first support plate.

[0023] One side arm of the first support plate has a guide portion, and the other side arm has a third guide groove. One side arm of the second support plate has a third guide groove that slides in cooperation with the guide portion of the first support plate, and the other side wall has a guide portion that slides in cooperation with the third guide groove of the first support plate.

[0024] The sides of the guide section and the third guide groove are both arcs centered on the rotation centers of the first support plate and the second support plate.

[0025] The sides of the guide section and the third guide groove are perpendicular to the axis of the drive mechanism.

[0026] The distal ends of the first and second support plates are both wedge-shaped. The distal ends of the first and second support plates are the first to be inserted into the intervertebral disc space. Designing this end into a wedge shape makes it easier for the fusion device to be inserted into the intervertebral disc space of patients with intervertebral disc disease, while minimizing damage to the surrounding anatomical structures.

[0027] Both the first and second support plates have anti-movement grooves on their bone fusion surfaces to prevent the fusion device from sliding after being implanted into the intervertebral space.

[0028] Both the first support plate and the second support plate are rotatably connected to the proximal wedge block via a second pin.

[0029] The sidewalls of the first support plate and the second support plate are provided with limiting holes. The second pin passes through the limiting hole and is rotatably connected to the proximal wedge. The limiting hole cooperates with the second pin to prevent the first support plate and the second support plate from opening at too large an angle.

[0030] The upper surface of the proximal wedge has a first support surface, the lower surface has a second support surface, the side of the proximal wedge extends to both sides to form a side ear, and the outer surface of the side ear is a third support surface;

[0031] The first and third support surfaces are used to bear the pressure of the first support plate, and the second and third support surfaces are used to bear the pressure of the second support plate and cooperate with the rotation of the first and second support plates.

[0032] The side ear portion is provided with a clamping groove that engages with the gripping hook of the gripper.

[0033] The driving mechanism includes a hollow sleeve and a threaded rod. The inner surface of the hollow sleeve has an internal thread, and the outer surface of the threaded rod has an external thread. The internal thread and the external thread are threadedly connected.

[0034] The proximal end of the hollow sleeve is rotatably connected to the proximal end wedge;

[0035] The threaded rod has a distal head and a threaded portion, the threaded portion being connected to the internal thread of the hollow sleeve, the distal wedge having a third groove, the distal head being located within the third groove and cooperating with the distal wedge to drive the distal wedge to move.

[0036] In one embodiment of the distal head, the distal head includes a flat surface and an arc surface, the arc surface is located on the upper and lower surfaces of the distal head, the flat surface is located on both sides of the distal head, and the distal head smoothly transitions to the threaded portion of the threaded rod.

[0037] The arc surface mates with the third inclined surface within the third groove, and the third inclined surface is a plane.

[0038] Another embodiment of the distal head: the surface of the distal head is a cylindrical surface, and the cylindrical surface smoothly transitions to the two sides of the distal head. The threaded rod also includes a non-threaded portion, and the non-threaded portion smoothly transitions to the distal head with a chamfer.

[0039] The cylindrical surface mates with the third inclined surface within the third groove, and the third inclined surface is an arc surface.

[0040] The driving mechanism further includes a limiting ring and a proximal head located on the proximal wedge. The proximal head includes a first annular groove, and the limiting ring is sleeved in the first annular groove to restrict the axial movement of the driving mechanism.

[0041] The drive mechanism includes a self-locking part to prevent the drive mechanism from rotating on its own.

[0042] The self-locking part includes a first groove and a pawl. Along the circumference of the drive mechanism, a plurality of the first grooves are provided on the outer surface of the proximal head to form a proximal tooth shape. The pawl is provided in the proximal wedge at a position that engages with the proximal tooth shape. The pawl and the proximal tooth shape engage to form a ratchet assembly for limiting the rotation of the drive mechanism.

[0043] A second groove is provided at the position where the proximal wedge mates with the first groove, and the pawl is installed in the second groove to provide space for elastic deformation of the pawl.

[0044] The second groove is provided on the proximal end face of the proximal wedge, and a stop block is provided in the direction of the proximal end of the second groove to prevent the pawl from falling off.

[0045] The fusion device can be opened at an angle of 0°-20°.

[0046] Because the present invention adopts the above technical solution, it has the following advantages and positive effects compared with the prior art:

[0047] The fusion cage provided by this invention is in a closed state during implantation. The fusion cage is relatively small in size. After implantation into the patient's intervertebral space, a tool-driven mechanism rotates, driving the distal wedge to move axially along the mechanism. This gradually moves the distal ends of the first and second support plates away from each other, increasing the height of the distal end of the fusion cage and gradually restoring the angle of the intervertebral space to the patient, thereby restoring the physiological curve of the spine. Therefore, it eliminates the need for surgeons to repeatedly insert the fusion cage into the intervertebral space using trial molding, reducing damage to surrounding anatomical structures and shortening surgical time. It also eliminates the need to excessively widen the distance between adjacent vertebrae, reducing excessive traction on muscles, nerves, and the dural sac during surgery, as is common with traditional fusion cages. Consequently, postoperative complications such as lumbar muscle pain and functional impairment are eliminated, improving patient comfort. Attached Figure Description

[0048] Figure 1 The angle of this embodiment of the invention can be used to open the closed state of the interbody fusion device;

[0049] Figure 2 The angle of the interbody fusion device can be opened in the following embodiment of the invention.

[0050] Figure 3 This is a partial cross-sectional view of the interbody fusion device that can be opened at an angle according to an embodiment of the present invention;

[0051] Figure 4 An exploded view of the interbody fusion device that can be opened at an angle according to an embodiment of the present invention;

[0052] Figure 5 This is a structural diagram of the distal wedge block according to an embodiment of the present invention;

[0053] Figure 6 The first distal wedge structure of this embodiment of the invention Figure 1 ;

[0054] Figure 7 The first distal wedge structure of this embodiment of the invention Figure 2 ;

[0055] Figure 8 The first distal wedge structure of this embodiment of the invention Figure 3 ;

[0056] Figure 9 The first distal wedge structure of this embodiment of the invention Figure 4 ;

[0057] Figure 10 The preferred embodiment of the first support plate of the present invention is as follows: Figure 1 ;

[0058] Figure 11 The preferred embodiment of the first support plate of the present invention is as follows: Figure 2 ;

[0059] Figure 12 The preferred embodiment of the first support plate of the present invention is as follows: Figure 3 ;

[0060] Figure 13 The structure of the second support plate in the embodiment of the present invention is preferred. Figure 1 ;

[0061] Figure 14 The structure of the second support plate in the embodiment of the present invention is preferred. Figure 2 ;

[0062] Figure 15 The structure of the second support plate in the embodiment of the present invention is preferred. Figure 3 ;

[0063] Figure 16 This is the structure of the first support plate or the second support plate in a second embodiment of the present invention. Figure 1 ;

[0064] Figure 17 This is the structure of the first support plate or the second support plate in a second embodiment of the present invention. Figure 2 ;

[0065] Figure 18 This is the structure of the first support plate or the second support plate in a second embodiment of the present invention. Figure 3 ;

[0066] Figure 19 for Figure 18 Enlarged view of section A;

[0067] Figure 20 The structure of the hollow sleeve in the first embodiment of the present invention Figure 1 ;

[0068] Figure 21 The structure of the hollow sleeve in the first embodiment of the present invention Figure 2 ;

[0069] Figure 22 This is a structural diagram of a second embodiment of the hollow sleeve of the present invention;

[0070] Figure 23 This is a structural diagram of a first embodiment of the threaded rod of the present invention;

[0071] Figure 24This is a structural diagram of a second embodiment of the threaded rod of the present invention;

[0072] Figure 25 The structure of the proximal wedge in an embodiment of the present invention Figure 1 ;

[0073] Figure 26 The structure of the proximal wedge in an embodiment of the present invention Figure 2 ;

[0074] Figure 27 The structure of the proximal wedge in an embodiment of the present invention Figure 3 ;

[0075] Figure 28 This is a front view of the proximal end face of the fusion device according to an embodiment of the present invention;

[0076] Figure 29 This is a cross-sectional view of the fusion device in an open state according to an embodiment of the present invention;

[0077] Figure 30 This is a structural diagram of the second distal wedge block according to an embodiment of the present invention. Detailed Implementation

[0078] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a more detailed account of an angle-openable interbody fusion device and spinal fusion system proposed in this invention. The advantages and features of the invention will become clearer from the following description. Obviously, the described embodiments are only some, not all, of the embodiments of the invention. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0079] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0080] It should be noted that similar labels in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0081] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0082] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted.

[0083] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0084] In the description of this application, "proximal end" refers to the end closer to the operator, and "distal end" refers to the end farther away from the operator.

[0085] See Figure 1-4 and Figure 29 This embodiment provides an angle-openable interbody fusion device suitable for interbody fusion surgery, especially in minimally invasive surgery. It includes a first support plate 1, a second support plate 2, a proximal wedge 3 and a distal wedge 4 located between the first support plate 1 and the second support plate 2, and a drive mechanism 5. The proximal ends of the first support plate 1 and the second support plate 2 are rotatably connected to the proximal wedge 3, respectively. The distal wedge 4 is slidably connected to the first support plate 1 and the second support plate 2. The proximal end of the drive mechanism 5 is axially rotatably connected to the proximal wedge 3, and the distal end is located within the distal wedge 4. The distal end of the drive mechanism 5 is used to push the distal wedge 4 to move. An external tool (generally a screwdriver in interbody fusion surgery) rotates the drive mechanism 5, causing the drive mechanism 5 to drive the distal wedge 4 to move along the axial direction of the drive mechanism 5, thus opening or closing the distal ends of the first support plate 1 and the second support plate 2.

[0086] The fusion device of this embodiment is implanted into the patient's intervertebral space in the closed state, where its volume is relatively small. After implantation, a screwdriver is used to rotate the drive mechanism 5. The drive mechanism 5 drives the distal wedge 4 to move along the axial direction of the drive mechanism 5. The distal ends of the first support plate 1 and the second support plate 2 move away from each other, thereby increasing the height of the distal end of the fusion device and achieving the purpose of restoring the physiological curve of the patient's spine. Therefore, after implantation, the fusion device of this embodiment can be adjusted to the desired intervertebral space angle without the need for the surgeon to repeatedly insert the device into the intervertebral space using a trial mold, reducing damage to the surrounding anatomical structures and shortening the operation time. At the same time, it does not require excessively widening the distance between adjacent vertebrae, reducing excessive traction on muscles, nerves, and dural sac during surgery as is done with traditional fusion devices. Therefore, postoperative sequelae such as lumbar muscle pain and functional impairment are eliminated, improving the patient's postoperative comfort.

[0087] like Figure 5-8 As shown, the fusion unit includes a distal wedge 4. During the opening process, the distal wedge 4 moves between the first support plate 1 and the second support plate 2 along the axis of the drive mechanism 5. To ensure the mechanical stability of the fusion unit, the distal wedge 4 rotates on an axis perpendicular to the axis of the drive mechanism 5 while moving. Figure 5-8 As shown, the distal wedge 4 includes a first distal wedge 401 and a second distal wedge 402. The first distal wedge 401 and the second distal wedge 402 are rotatably connected by a first pin 6. In this embodiment, the first distal wedge 401 and the second distal wedge 402 are designed with the same structure. Taking the first distal wedge 401 as an example, the following is a detailed description: The first distal wedge 401 includes a main body, a first support block 4014 and a second support block 4015. The main body includes a driving inclined surface and a limiting surface that contact the first support plate 1 and the second support plate 2. The driving inclined surface slides with the first support plate 1 and the second support plate 2 to drive and open the first support plate 1 and the second support plate 2. The limiting surface cooperates with the first support plate 1 and the second support plate 2 when they are closed, and has a terminating function when they are closed. The third groove 4018, formed by the first support block 4014, the second support block 4015, and the main body, is used to accommodate the distal end of the drive mechanism 5. Both the first support block 4014 and the second support block 4015 are provided with first through holes 4017. The first pin 6 passes through the first through hole 4017, realizing the rotatable connection between the first distal wedge 401 and the second distal wedge 402. In this embodiment, to reduce costs, the first support block 4014 and the second support block 4015 are designed eccentrically, so that the first distal wedge 401 and the second distal wedge 402 can be designed with the same structure. Of course, the first support block 4014 and the second support block 4015 can also be designed symmetrically; no limitation is made here.

[0088] See Figure 7 and Figure 30The driving inclined surface includes a first driving inclined surface 4012 and a second driving inclined surface 4022. The first driving inclined surface 4012 is located on the first distal wedge 401, and the second driving inclined surface 4022 is located on the second distal wedge 402. The first driving inclined surface 4012 is slidably engaged with the first inclined surface 1003 of the first support plate 1, and the second driving inclined surface 4022 is slidably engaged with the second inclined surface 2003 of the second support plate 2. During the movement of the distal wedge 4, the first driving inclined surface 4012 and the first inclined surface 1003 always maintain surface-to-surface contact, and the second driving inclined surface 4022 and the second inclined surface 2003 always maintain surface-to-surface contact. Thus, during the movement of the distal wedge 4, the first driving inclined surface 4012 drives the first support plate 1 to open, and the second driving inclined surface 4022 drives the second support plate 2 to open.

[0089] To maintain the stability of the distal wedge 4 during movement, a guide block and a guide groove are provided between the distal wedge 4 and the first support plate 1 and the second support plate 2. The guide block is embedded in the guide groove to achieve a guiding function. The guide groove is a dovetail groove, and the guide block is a dovetail structure that slides with the dovetail groove; or the guide groove is a concave groove, and the guide block is a convex structure that slides with the concave groove. It should be noted that the guide block and guide groove can also be other sliding fit structures, which are not listed in this embodiment.

[0090] The following lists the installation of guide grooves and guide blocks at the distal wedge 4, the first support plate 1, and the second support plate 2:

[0091] First implementation method: such as Figure 8 , 11 As shown in 14 and 30, a first guide block 4016 is provided on the first driving inclined surface 4012, a second guide block 4026 is provided on the second driving inclined surface 4022, a first support plate 1 is provided with a first guide groove 1001 that slides with the first guide block 4016, and a second support plate 2 is provided with a second guide groove 2001 that slides with the second guide block 4026.

[0092] The second implementation: a first guide groove 1001 is provided on the first driving inclined surface 4012, a second guide groove 2001 is provided on the second driving inclined surface 4022, a first support plate 1 is provided with a first guide block 4016 that slides with the first guide groove 1001, and a second support plate 2 is provided with a second guide block 4026 that slides with the second guide groove 2001.

[0093] Of course, the first driving inclined surface can also have both a first guide block and a first guide groove, and the first support plate 1 can also have both a first guide block and a first guide groove. The second driving inclined surface and the second support plate can also be configured as described above or as in the first or second implementation method. No restrictions are imposed here.

[0094] like Figure 7 , 30 As shown, the limiting surface includes a first limiting surface 4013 and a second limiting surface 4023. The first limiting surface 4013 is located on the first distal wedge 401, and the second limiting surface 4023 is located on the second distal wedge 402. The first limiting surface 4013 engages with the first support plate 1 when closed, and the second limiting surface 4023 engages with the second support plate 2 when closed.

[0095] The preferred embodiment of the distal wedge 4 has been described above. This invention also includes a configuration where the distal wedge 4 can expand the first support plate 1 and the second support plate 2 even when it is moving. In this embodiment, the preferred embodiment where the distal wedge 4 is rotatable provides a more compact fit between the distal wedge 4 and the first support plate 1 and the second support plate 2, resulting in more stable mechanical performance. The advantages of the preferred embodiment are illustrated using the first guide block 4016 and the first guide groove 1001 as examples. In actual simulations, it was found that when the first guide block 4016 is slidably fitted within the first guide groove 1001, a large gap exists within the first guide groove 1001, meaning the first guide block 4016 does not completely fill the first guide groove 1001, leading to instability in the entire fusion device. Therefore, to make the fit between the distal wedge 4 and the first support plate 1 and the second support plate 2 tighter, this embodiment, based on the above, finds that designing the distal wedge 4 to be rotatable during movement solves the aforementioned stability problem. Therefore, the preferred embodiment is one where the distal wedge 4 is rotatable, with the first guide block 4016... The first guide groove 1001 is more compactly fitted, and the force received by the first guide block 4016 and the first guide groove 1001 is transferred to the first pin 6. During the movement of the distal wedge 4, the first support plate 1 and the second support plate 2 maintain surface-to-surface contact with the distal wedge 4, which makes the fusion device more stable in the lateral direction and smaller in size.

[0096] like Figure 10 and Figure 14 As shown, the first support plate 1 in the fusion device supports the first part of the vertebral body, and the second support plate 2 supports the second part of the vertebral body. Both the first and second support plates have bone fusion surfaces that contact adjacent vertebral bodies. Anti-movement grooves 1009 and 2009 are provided on the bone fusion surfaces to prevent the fusion device from sliding or spontaneously exiting the intervertebral space after implantation. The anti-movement grooves 1009 and 2009 can be toothed as shown in the figure, or they can be created by other treatment methods (e.g., sandblasting) to produce a rough or uneven surface on the bone contact surface to promote bone growth.

[0097] like Figure 4 , 10As shown in -15 and 28, the proximal ends of the first support plate 1 and the second support plate 2 are rotatably connected to the proximal wedge 3, respectively. They can be rotatably connected to the proximal wedge 3 via a second pin 7. The second pin 7 passes through the limiting holes 1005 and 2005 of the first support plate 1 and the second support plate 2 and the pin hole 308 on the proximal wedge 3, so that the first support plate 1 and the second support plate 2 can be rotatably connected to the proximal wedge 3. The first support plate 1 and the second support plate 2 can rotate relative to the proximal wedge 3 by the push of the distal wedge 4. The limiting holes 1005 and 2005 and the pin hole 308 are located at the proximal end of the entire fusion device. Therefore, after the distal ends of the first support plate 1 and the second support plate 2 rotate in a direction away from each other, the height of the distal end of the fusion device increases, thereby restoring a more natural lordosis curvature of a specific segment of the lumbar spine.

[0098] In addition to connecting the second pin 7, the limiting holes 1005 and 2005 also restrict the first support plate 1 and the second support plate 2 from being overly spread. In this embodiment, the limiting holes 1005 and 2005 are similar to waist-shaped holes, and the straight part in the waist-shaped hole is also designed as an arc shape to ensure the rotation of the first support plate 1 and the second support plate 2.

[0099] Both the first support plate 1 and the second support plate 2 feature a central hollow design, with bone graft windows 1010 and 2010 for implanting bone fillers to facilitate rapid fusion with adjacent vertebral bodies. The distal ends of both the first support plate 1 and the second support plate 2 are designed in a wedge shape 1008 and 2008 to help the fusion device insert into the collapsed intervertebral disc space in patients with degenerative disc disease, while minimizing damage to surrounding anatomical structures.

[0100] In order for the first support plate 1 and the second support plate 2 to serve a guiding function during the expansion of the fusion device, such as Figure 9-12 As shown, a guide portion 1004 is formed by extending the side wall of at least one of the first support plate 1 and the second support plate 2 toward the other support plate. A third guide groove 2004 is provided on the side wall of at least one of the first support plate 1 and the second support plate 2. The guide portion 1004 and the third guide groove 2004 are slidably engaged.

[0101] See Figure 10-18 As shown, specifically, both the first support plate 1 and the second support plate 2 include first sidewalls 1011 and 2011, and second sidewalls 1012 and 2012, a guide portion 1004, and a third guide groove 2004. In one first embodiment, the first support plate 1 and the second support plate 2 are designed with the same structure, such as... Figure 16-18As shown, the first sidewalls 1011' and 2011' have guide portions 1004', and the second sidewalls 1012' and 2012' have third guide grooves 2004'. The third guide grooves 2004' and guide portions 1004' play a longitudinal guiding role during the opening process, and this embodiment saves processing costs on the types of workpieces. In some alternative embodiments, such as Figure 17-19 As shown, the third guide groove 2004' includes a first wall 20041', a second wall 20042', and a third wall 20043'. The side wall of the guide portion 1004 has a protrusion 10041'. The first wall 20041', the second wall 20042', and the third wall 20043' form a groove to accommodate the protrusion 10041'. The guide portion 1004 and the third guide groove 2004, which are used in this way, can slide together to achieve both longitudinal and lateral guiding functions, thus avoiding the problem of shaking during the opening process.

[0102] In alternative embodiments, such as Figure 10-15 In the illustrated implementation, the first sidewall 1011 and the second sidewall 1012 of the first support plate 1 have guide portions 1004, and the first sidewall 2011 and the second sidewall 2012 of the second support plate 2 have third guide grooves 2004, or the first sidewall 1011 and the second sidewall 1012 of the first support plate 1 have third guide grooves 2004, and the first sidewall 2011 and the second sidewall 2012 of the second support plate 2 have guide portions 1004. This can also achieve longitudinal and lateral guiding functions, solve the swaying problem during the opening process, and at the same time reduce processing costs without weakening the strength of the second support plate 2. There are many ways to achieve the guiding function during the opening process. For example, both sidewalls (inner sidewalls or outer sidewalls) of the first support plate 1 and the second support plate 2 can extend towards each other to form an extension column and an extension wall. The extension wall includes a groove to accommodate the extension column, which is not limited here.

[0103] In this embodiment, the side surfaces of the guide portions 1004, 1004' and the third guide grooves 2004, 2004' are preferably arcs centered on the rotation centers of the first support plate 1 and the second support plate 2. Specifically, the guide portion 1004 and the third guide groove 2004 are described below. Figure 10-15The guide portion 1004 includes a first side surface 10044, and the third guide groove 2004, which slides with the guide portion 1004, has a second side surface 20044. The first side surface 10044 and the second side surface 20044 are surfaces perpendicular to the axis of the drive mechanism 5. The first side surface 10044 and the second side surface 20044 slide with each other to ensure that the first support plate 1 and the second support plate 2 are stably engaged in the axial direction of the drive mechanism 5 during the opening process of the fusion device. In order to make the first support plate 1 and the second support plate 2 more compactly engaged during the opening process, the first side surface 10044 and the second side surface 20044 are arc surfaces, and the arc surfaces are centered on the rotation center of the first support plate 1 and the second support plate 2.

[0104] In this embodiment, the first support plate 1 and the second support plate 2 are identical in structure except for the guide portion 1004 and the third guide groove 2004. The surfaces of the first support plate 1 and the second support plate 2 facing each other are their inner surfaces. The inner surface of the first support plate 1 has a first inclined surface 1003 that slides with the first proximal wedge 3, and the inner surface of the second support plate 2 has a second inclined surface 2003 that slides with the second proximal wedge 3. The front end of the inner surface of the first support plate 1 has a fourth groove 1002, and the front end of the inner surface of the second support plate 2 has a fifth groove 2002. When the fusion device is in the closed state, the fourth groove 1002 and the fifth groove 2002 are used to accommodate the distal wedge 4.

[0105] See Figure 4 20-24, the fusion unit also includes a drive mechanism 5, which comprises a hollow sleeve 501 and a threaded rod 502, connected by threads. The drive mechanism 5 can also have other structures, such as an integral structure, or a drive mechanism with its distal end threadedly connected to a distal wedge, etc., which will not be listed here. Even in a split structure, except... Figure 4 In addition to the structure shown, it can also be: a threaded rod 502 connected to the proximal wedge 3, and a hollow sleeve 501 cooperating with the distal wedge 4. Considering that the drive mechanism 5 cooperates with the third groove 4018 of the distal wedge 4, if the two implementations achieve the same strength, this embodiment is the preferred implementation. The diameter of the hollow sleeve 501 can be reduced, thereby reducing the size of the distal end of the drive mechanism 5, and thus reducing the volume of the distal wedge 4, so that the volume of the entire fusion device will also be smaller. Therefore, in this embodiment, it is preferred to select the threaded rod 502 to cooperate with the distal wedge 4, and the hollow sleeve 501 to cooperate with the proximal wedge 3.

[0106] See details Figure 20-22The hollow sleeve 501 includes a proximal head 5017. The distal portion of the hollow sleeve is hollow along the axial direction, and the inner surface of the hollow structure has an internal thread 5015. The proximal head 5017 is rotatably connected to the proximal wedge 3. The proximal head 5017 of the hollow sleeve 501 is provided with a socket 5013 for connecting to a screwdriver or other mechanisms (such as a slotted or Phillips head screwdriver head or Torx screwdriver hole, etc.). To facilitate screwdriver insertion into the socket, a chamfer 5014 is provided around the socket. The screwdriver acts on the drive mechanism 5, and the drive mechanism 5 rotates relative to the proximal wedge 3. To prevent the hollow sleeve 501 from moving axially relative to the proximal wedge 3, a limiting ring 8 is provided at the mating position of the proximal wedge 3 and the drive mechanism 5. The proximal head 5017 is provided with a first annular groove 5011, and the limiting ring 8 is fitted within the first annular groove 5011 to restrict the axial movement of the drive mechanism 5. For ease of installation, the limiting ring 8 can be a C-shaped ring with elasticity. The proximal head 5017 also has a fixing step 5016, which cooperates with the proximal wedge 3 to fix the point of application of tensile force during the opening process.

[0107] After the fusion cage is implanted into the lumbar intervertebral disc and the patient resumes normal activity, the implant will be subjected to forces and strains that cause the drive mechanism 5 to retract, resulting in the fusion cage contracting and a smaller opening angle. Although the threaded structure has a certain self-locking capability, in order to further prevent the drive mechanism 5 from rotating and causing a change in the opening angle, a self-locking part is provided at the position where the proximal head 5017 engages with the proximal wedge. The self-locking part includes a pawl. Specifically, along the circumference of the drive mechanism 5, multiple first grooves 5012 are provided on the outer surface of the proximal head 5017, forming a proximal tooth shape. The proximal surface of the proximal head 5017 forms a proximal tooth surface. A pawl 9 is provided in the proximal wedge 3 at a position that mates with the proximal tooth shape. The pawl 9 and the proximal tooth shape mate to form a ratchet assembly. In this way, the pawl 9 presses against the proximal tooth surface of the drive mechanism 5, thereby enabling the drive mechanism 5 to rotate clockwise or counterclockwise. A certain rotational force is required for rotation, so that after the fusion device is implanted into the vertebral body and expanded, the drive structure 5 cannot rotate when no sufficient external force is applied to the drive mechanism 5. That is, the first support plate 1 and the second support plate 2 can remain self-locking and not collapse. The first groove 5012 is located in the part between the end face of the proximal head 5017 and the first annular groove 5011. The first groove 5012 can connect from the end face of the proximal head 5017 to the first annular groove 5011. Figure 20 ), or not connected ( Figure 19 Considering processing costs and difficulty, non-connected systems are preferred.

[0108] The pawl 9 is an elastically deformable element. It can be integrated with or become part of the proximal wedge 3, and can bend relative to the proximal wedge 3 and the drive mechanism 5. This allows the proximal end of the drive mechanism 5 to produce a ratchet-like effect in one direction. When the drive mechanism 5 attempts to rotate, the bend of the pawl 9 is restricted by the engagement between the pawl 9 and the proximal surface of the drive mechanism 5. Specifically: see... Figure 28 A second groove 305 is provided at the mating position of the first groove 5012 on the proximal head 5017 of the hollow sleeve 501 with the proximal wedge 3. The pawl 9 is installed within the second groove 305, providing space for elastic deformation. The second groove 305 is located on the proximal end face of the proximal wedge 3, and a stop block 306 is provided in the direction of the proximal end of the second groove 305 to prevent the pawl 9 from falling off. (See reference...) Figure 28 The pawl 9 has a protrusion 901 embedded in the first groove 5012. The protrusion 901 engages with the proximal teeth of the drive mechanism 5 to form a meshing ratchet assembly. Due to the proximal teeth and proximal tooth surface formed by the first groove 5012, the drive mechanism can only rotate when an external force is applied to the protrusion 901, allowing it to move along the proximal tooth surface, so that the fusion assembly is opened by the pawl 9. If the drive mechanism 5 is moved in the opposite direction, the pawl 9 will not move radially. Thus, the pawl 9 can limit or prevent the drive mechanism 5 from rotating in the opposite direction (to prevent the fusion assembly from collapsing). Therefore, the pawl 9 can prevent the drive mechanism 5 from accidentally disengaging and the fusion assembly from loosening or shrinking. However, if the torque applied to the proximal head 5017 of the drive mechanism 5 is large enough, the proximal head 5017 can rotate in the opposite direction (causing the fusion assembly to collapse). The pawl 9 may comprise any suitable elastic material that allows bending or deflection and can return to its initial state. The second groove 305 provides space for the pawl 9 to elastically deform. To allow the pawl 9 to be fitted into the second groove 305, the pawl 9 also includes a support portion 902, which is supported within a support groove 304 in the second groove 305, providing support for the pawl 9. To prevent the pawl 9 from dislodging from the second groove 305, a stop block 306 is provided on the side of the pawl 9 facing the proximal end of the fusion device, confining the pawl 9 within the second groove 306.

[0109] See Figure 23-24In a first embodiment of the threaded rod 502: the threaded rod 502 includes a distal head 5027, and the outer surface of the proximal portion of the threaded rod 502 has an external thread 5025. The distal head 5027 is located in a third groove 4018 within the distal wedge 4. The distal head 5027 and the external thread 5025 are partially arc-shaped transitions 5024. The distal portion of the hollow sleeve 501 is threadedly connected to the proximal portion of the threaded rod 502. The distal head 5027 has a second through hole 5022 through which the first pin 6 passes. The distal head 5027 also has a flat surface 5021 and an arc surface 5023 that mate with the distal wedge 4. The flat surface 5021 mates with the first support block 4014 and the second support block 4015, and the arc surface 5023 mates with the third inclined surface 4011 within the third groove 4018.

[0110] Threaded rod 502 can also be as follows Figure 24 The second embodiment shown also includes a distal head 5027' and a threaded portion 5025', as well as a non-threaded portion 5026' connecting the distal head 5027' and the threaded portion 5025'. The distal head 5027' has a second through hole 5022' through which the first pin 6 passes. The distal head 5027' is generally cylindrical in shape, with a smooth cylindrical surface 5023'. The side 5021' of the distal head 5027' smoothly transitions to the cylindrical surface 5023'. The non-threaded portion 5026' of the threaded rod 502 and the distal head 5027 require a smooth chamfer 5024' transition. The third inclined surface 4011' that mates with the cylindrical surface 5023' must be an arc surface. Figure 9 ).

[0111] See Figure 25-27 The proximal wedge 3 is used to support the first support plate 1 and the second support plate 2, and to cooperate with the proximal end of the drive mechanism 5. The upper surface of the proximal wedge 3 has a first support surface 303, the lower surface has a second support surface 312, and the side of the proximal wedge 3 extends to both sides to form a side ear 311. The outer surface of the side ear 311 is a third support surface 302.

[0112] See Figure 11 The proximal end of the first support plate 1 has a first bearing surface 1007 and a second bearing surface 1006, see reference. Figure 13 The proximal end of the second support plate 2 has a third bearing surface 2007 and a fourth bearing surface 2006. The first support surface 303 cooperates with the first bearing surface 1007, and the third support surface 302 cooperates with the second bearing surface 1006, so that the first support plate 1 rotates around the proximal wedge 3. The second support surface 312 cooperates with the third bearing surface 2007, and the third support surface 302 cooperates with the fourth bearing surface 2006, so that the second support plate 2 rotates around the proximal wedge 3.

[0113] The first support surface 303 and the third support surface 302 are used to bear the pressure of the first support plate 1, and the second support surface 312 and the third support surface 302 are used to bear the pressure of the second support plate 2, and cooperate with the rotation of the first support plate 1 and the second support plate 2.

[0114] The lateral ear portion 311 is provided with a clamping groove 301 that cooperates with the gripping hook of the reamer. The reamer is clamped in the clamping groove 301, and the fusion device is implanted into the collapsed intervertebral disc space of the patient.

[0115] The proximal wedge 3 has a third through hole 307 through which the drive mechanism 5 passes. The third through hole 307 has a second annular groove 310 that mates with the limiting ring 8. After the drive mechanism 5 is installed on the proximal wedge 3, the limiting ring 8 is embedded in the second annular groove 310. The diameter of the limiting ring 8 is larger than the diameter of the proximal head 5017, thereby limiting the axial movement of the drive mechanism 5.

[0116] The proximal wedge 3 has a step groove 309 that mates with the fixed step 5016 on the proximal head 5017, providing a supporting force.

[0117] The fusion device in this embodiment is mainly used between L4 and L5 and between L5 and sacrum. The opening angle of the fusion device is 0°-20°. The surgeon can gradually open it to a 20° oblique lordosis or lordosis angle according to the patient's clinical needs.

[0118] The expandable fusion device provided in this embodiment includes a first support plate 1, a second support plate 2, a proximal wedge 3, a distal wedge 4, and a drive mechanism 5. In the initial state, the distal wedge 4 is located within the fourth groove 1002 and the fifth groove 2002, and both the first support plate 1 and the second support plate 2 are parallel to the horizontal plane. At this time, the fusion device is in a closed state. When the fusion device is implanted into the patient and needs to be expanded, a screwdriver is inserted into the port 5013 on the proximal end face of the drive mechanism 5, and the hollow sleeve 501 is rotated, causing the threaded rod 502 to move. This moves the distal wedge 4 along the axial direction of the drive mechanism 5, while simultaneously rotating the distal wedge 4 around the first pin 6. This causes the distal ends of the first support plate 1 and the second support plate 2 to expand synchronously, increasing the distal end height and thus expanding the fusion device. Surgeons can gradually open the intervertebral space to the appropriate angle according to the patient's clinical needs, without the need for repeated insertion of the intervertebral space by the surgeon to test the mold, which reduces damage to the surrounding anatomical structures and shortens the operation time. At the same time, it does not require opening the distance between adjacent vertebrae too high, which reduces the excessive traction on muscles, nerves and dural sac during the operation when implanting traditional fusion devices. Therefore, there are no sequelae such as lumbar muscle pain and functional impairment after the operation, which improves the patient's postoperative comfort.

[0119] Furthermore, during the opening process, the distal wedge 4 has a sliding fit with the first support plate 1 and the second support plate 2, while the proximal wedge 3 has a support surface that supports the first support plate 1 and the second support plate 2. A self-locking part is further provided in the fit between the drive mechanism 5 and the proximal wedge 3 to prevent the drive mechanism 5 from rotating. All components form an organic whole, cooperating and restraining each other, resulting in high structural stability and resistance to deformation. Simultaneously, the distal wedge 4 can rotate, making the sliding fit between the distal wedge 4 and the first support plate 1 and the second support plate 2 more compact. The first distal wedge 401 and the first support plate 1, and the second distal wedge 402 and the second support plate 2, are always in planar contact. When the fusion device is opened to its maximum position, the structural stability and strength of the fusion device are guaranteed, ensuring safe and reliable use.

[0120] The fusion device shown in this embodiment can be used in PLIF (posterior interbody fusion) surgery, which can be used as an open surgery or a minimally invasive surgery. However, the fusion device of the present invention can also be used in TLIF (translumbar interbody fusion) surgery, which requires adaptive modifications to the structure. However, the inventive concept is the same and it is also within the scope of the present invention.

[0121] This embodiment describes multiple implementations of each component, mainly focusing on the differences between each implementation, without repeating any identical settings.

[0122] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. An angularly distractible intervertebral cage, comprising: include: The first support plate is used to support the first part of the vertebral body; The second support plate is used to support the second part of the vertebral body; A proximal wedge is located between the first support plate and the second support plate, and the proximal ends of the first support plate and the second support plate are respectively rotatably connected to the proximal wedge. A distal wedge is located between the first support plate and the second support plate, and the distal wedge is slidably connected to the first support plate and the second support plate; A drive mechanism, wherein the distal end of the drive mechanism is located within the distal wedge, and the proximal end is rotatably connected to the proximal wedge; An external tool rotates the drive mechanism, which drives the distal wedge to move along the axial direction of the drive mechanism, thereby opening or closing the distal ends of the first and second support plates. During the movement of the distal wedge between the first support plate and the second support plate, the distal wedge is rotatable; The distal wedge includes a first distal wedge and a second distal wedge, which are rotatably connected. When the distal wedge moves along the axial direction of the drive mechanism, the first distal wedge and the second distal wedge rotate relative to each other. A first driving inclined surface is provided on the first distal wedge, and a second driving inclined surface is provided on the second distal wedge. The first driving inclined surface slides in cooperation with the first inclined surface of the first support plate, and the second driving inclined surface slides in cooperation with the second inclined surface of the second support plate.

2. The angularly distractible interbody fusion cage of claim 1, wherein, The first distal wedge and the second distal wedge are rotatably connected by a first pin.

3. The angularly distractible interbody fusion cage of claim 1, wherein, A first guide block is provided on the first driving inclined surface, and a second guide block is provided on the second driving inclined surface. The first support plate has a first guide groove that slides with the first guide block, and the second support plate has a second guide groove that slides with the second guide block; or The first driving inclined surface is provided with a first guide groove, the second driving inclined surface is provided with a second guide groove, the first support plate is provided with a first guide block that slides in cooperation with the first guide groove, and the second support plate is provided with a second guide block that slides in cooperation with the second guide groove.

4. The interbody fusion cage with an angle that can be opened according to claim 1, characterized in that, At least one of the first support plate and the second support plate has a sidewall that extends toward the other support plate to form a guide portion. At least one of the first support plate and the second support plate has a third guide groove on its sidewall, and the guide portion slides in conjunction with the third guide groove.

5. The interbody fusion cage with an angle that can be opened according to claim 4, characterized in that, The first support plate has guide portions on both sides, and the second support plate has third guide grooves on both sides that slide in cooperation with the guide portions of the first support plate.

6. The interbody fusion cage with an angle that can be opened according to claim 4, characterized in that, One side arm of the first support plate has a guide portion, and the other side arm has a third guide groove. One side arm of the second support plate has a third guide groove that slides in cooperation with the guide portion of the first support plate, and the other side wall has a guide portion that slides in cooperation with the third guide groove of the first support plate.

7. The angle-openable interbody fusion cage according to any one of claims 4-6, characterized in that, The sides of the guide section and the third guide groove are both arcs centered on the rotation centers of the first support plate and the second support plate. The sides of the guide section and the third guide groove are perpendicular to the axis of the drive mechanism.

8. The interbody fusion device with an angle that can be opened according to claim 1, characterized in that, Both the first support plate and the second support plate are rotatably connected to the proximal wedge block via a second pin.

9. The interbody fusion device with an angle that can be opened according to claim 8, characterized in that, The sidewalls of the first support plate and the second support plate are provided with limiting holes. The second pin passes through the limiting hole and is rotatably connected to the proximal wedge. The limiting hole cooperates with the second pin to prevent the first support plate and the second support plate from opening at too large an angle.

10. The interbody fusion device with an angle that can be opened according to claim 1, characterized in that, The upper surface of the proximal wedge has a first support surface, the lower surface has a second support surface, the side of the proximal wedge extends to both sides to form a side ear, and the outer surface of the side ear is a third support surface; The first and third support surfaces are used to bear the pressure of the first support plate, and the second and third support surfaces are used to bear the pressure of the second support plate, and cooperate with the rotation of the first and second support plates.

11. The angle-openable interbody fusion device according to claim 10, characterized in that, The side ear portion is provided with a clamping groove that engages with the gripping hook of the gripper.

12. The angle-openable interbody fusion device according to claim 1, characterized in that, The drive mechanism includes a hollow sleeve with an internal threaded surface and a threaded rod, the internal threaded surface being connected to the external threaded surface of the threaded rod.

13. The angle-openable interbody fusion device according to claim 12, characterized in that, The proximal end of the hollow sleeve is rotatably connected to the proximal end wedge; The threaded rod includes a distal head, and the distal wedge has a third groove. The distal head is located in the third groove and cooperates with the distal wedge to drive the distal wedge to move.

14. The angle-openable interbody fusion device according to claim 13, characterized in that, The distal head includes a flat surface and an arc surface, the arc surface being located on the upper and lower surfaces of the distal head, and the flat surface being located on both sides of the distal head; The arc surface mates with the third inclined surface within the third groove, and the third inclined surface is a plane.

15. The angle-openable interbody fusion device according to claim 13, characterized in that, The surface of the distal head is a cylindrical surface; The cylindrical surface mates with the third inclined surface within the third groove, and the third inclined surface is an arc surface.

16. The interbody fusion cage that can be opened at the angle according to claim 1 or 12, characterized in that, The drive mechanism further includes a limiting ring and a proximal head that cooperates with the proximal wedge. The proximal head includes a first annular groove, and the limiting ring is sleeved in the first annular groove to limit the axial movement of the drive mechanism.

17. The angle-openable interbody fusion device according to claim 16, characterized in that, The drive mechanism includes a self-locking part for limiting the rotation of the drive mechanism.

18. The angle-openable interbody fusion device according to claim 17, characterized in that, The self-locking part includes a first groove and a pawl. Along the circumference of the drive mechanism, a plurality of the first grooves are provided on the outer surface of the proximal head to form a proximal tooth shape. The pawl is provided in the proximal wedge at a position that engages with the proximal tooth shape. The pawl and the proximal tooth shape engage to form a ratchet assembly for limiting the rotation of the drive mechanism.

19. The angle-openable interbody fusion device according to claim 18, characterized in that, A second groove is provided at the position where the proximal wedge mates with the first groove, and the pawl is installed in the second groove to provide space for elastic deformation of the pawl.

20. The angle-openable interbody fusion device according to claim 19, characterized in that, The second groove is provided on the proximal end face of the proximal wedge, and a stop block is provided in the direction of the proximal end of the second groove to prevent the pawl from falling off.

21. The angle-openable interbody fusion device according to claim 1, characterized in that, The fusion device can be opened at an angle of 0°-20°.

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