Expandable vertebral body fusion device

Abstract

An expandable vertebral body device includes a base assembly having ends that can be moved relative to each other by adjusting a first end adjustment mechanism. A plurality of movable plates are movably disposed on the base assembly, and when the ends move relative to each other, they can move at least longitudinally relative to the base assembly. Each end is provided with a pair of longitudinal guide elements and may also have a pair of transverse guide elements. Each movable plate includes a longitudinal guide that can move along the corresponding longitudinal guide element and may also have a transverse guide that can move along the corresponding transverse guide element. When the ends are brought closer together by adjustment of the adjustment mechanism, if the guide rail moves along the corresponding guide element, the movable plate moves outward from the longitudinal axis of the base assembly.

Description

Technical Field

[0001] The present invention relates to a medical device implanted in a patient's spine to adjust or maintain the distance between vertebrae, and in particular to an expandable cone device. Background Art

[0002] Expandable devices are known for adjusting or maintaining the relative position of adjacent vertebrae in a patient, such as those described in U.S. Patents Nos. 8,940,048, 8,105,382, and 8,894,712, and U.S. Publication No. US-2019-0388232. Summary of the Invention

[0003] The present invention provides an expandable vertebral body device, comprising:

[0004] A base assembly includes a first end portion and a second end portion, wherein the first end portion and the second end portion can be moved relative to each other by adjusting an adjustment mechanism of the first end portion;

[0005] a plurality of movable panels movably disposed on the base assembly and movable at least longitudinally relative to the base assembly when the first end portion and the second end portion are moved relative to each other;

[0006] Wherein, a longitudinal guide channel is provided in the central area of the upper side and the lower side of the first end portion and the second end portion respectively;

[0007] Wherein, each end of the plurality of movable plates is provided with at least one longitudinal guide element, and each longitudinal guide element is movably accommodated in a longitudinal guide channel corresponding to the first end and the second end; and

[0008] When the first end and the second end are brought closer together by adjusting the adjusting mechanism, the longitudinal guide element moves along the corresponding longitudinal guide channel, and the movable plate can move at least longitudinally outward from the longitudinal axis of the base assembly.

[0009] It should be noted that the longitudinal axis of the base assembly refers to the central axis of the base assembly in the direction connecting the first end and the second end; the "longitudinal movement" in "when the first end and the second end move relative to each other, they can at least move longitudinally relative to the base assembly" refers to movement in the vertical direction relative to the longitudinal axis of the base assembly.

[0010] In some embodiments, each of the longitudinal guide channels is located between an outer longitudinal slope of the main body portion of the corresponding first end or second end and an inner slope of a longitudinal positioning element protruding from the main body portion of the corresponding first end or second end.

[0011] In some embodiments, at least one transverse guide channel is respectively provided on the laterally opposite sides of the first end and the second end, and transverse guide elements are respectively provided at both ends of each of the multiple movable panels, and each transverse guide element is movable in a corresponding transverse guide channel in the first end and the second end.

[0012] In some embodiments, the transverse guide channel extends parallel to the longitudinal axis of the base assembly, and when the longitudinal guide element moves along the corresponding longitudinal guide channel and the transverse guide element moves along the corresponding transverse guide channel, the movable plate can move longitudinally outward from the longitudinal axis of the base assembly.

[0013] It should be noted that the “longitudinal axis of the base assembly” refers to the central axis of the base assembly in the direction connecting the first end and the second end.

[0014] In some embodiments, the plurality of movable plates include an upper plate and a lower plate.

[0015] In some embodiments, each of the longitudinal guide channels is located between the external longitudinal inclined surface of the corresponding first end or second end main body portion and the internal inclined surface of the longitudinal positioning element protruding from the main body portion of the corresponding first end or second end, and the transverse guide channel is located between the external transverse inclined surface of the corresponding first end or second end main body portion and the internal inclined surface of the transverse positioning element protruding from the main body portion of the corresponding first end or second end.

[0016] In some embodiments, when the adjustment mechanism is adjusted to bring the first end and the second end closer together, the inner slope of the longitudinal positioning element moves along the outer surface of the longitudinal guide element, and the inner slope of the transverse positioning element moves along the outer surface of the transverse guide element.

[0017] In some embodiments, when the adjustment mechanism is adjusted to move the first end and the second end away, the outer longitudinal slope of the end body portion moves along the inner surface of the longitudinal guide element, and the outer transverse slope of the end body portion moves along the inner surface of the transverse guide element.

[0018] In some embodiments, the transverse guide channel forms a certain angle relative to the longitudinal axis of the base assembly, and when the longitudinal guide element moves along the corresponding longitudinal guide channel and the transverse guide element moves along the corresponding transverse guide channel, the movable plate can move longitudinally and transversely outward from the longitudinal axis of the base assembly.

[0019] In some embodiments, the multiple movable plates include a first group of plates and a second group of plates, respectively, wherein each group of plates includes an upper plate and a lower plate, respectively. When the adjustment mechanism is adjusted to bring the first end and the second end closer together, the first group of plates is separated laterally from the second group of plates, and the upper plate is separated longitudinally from the lower plate.

[0020] In some embodiments, the upper plate is movably connected to the lower plate by a longitudinal connector, which maintains the upper plate and the lower plate in the first and second sets of plates in transverse alignment while allowing the upper plate and the lower plate to move longitudinally relative to each other.

[0021] In some embodiments, the plurality of movable plates include a first upper plate, a second upper plate, a first lower plate, and a second lower plate.

[0022] In some embodiments, the longitudinal guide elements at both ends of the first upper plate and the second upper plate can be movably accommodated in the longitudinal guide channels corresponding to the upper sides of the first end and the second end, and the longitudinal guide elements at both ends of the first lower plate and the second lower plate can be movably accommodated in the longitudinal guide channels corresponding to the lower sides of the first end and the second end.

[0023] In some embodiments, the lateral guide elements at both ends of the first upper plate and the first lower plate can be movably accommodated in the lateral guide channels of the first lateral side corresponding to the first end and the second end, and the lateral guide elements at both ends of the second upper plate and the second lower plate can be movably accommodated in the lateral guide channels of the second lateral side corresponding to the first and second ends.

[0024] In some embodiments, the first upper plate is movably connected to the first lower plate by a first longitudinal connecting element, which is used to maintain the first upper plate and the first lower plate in transverse alignment while allowing the first upper plate and the first lower plate to move longitudinally relative to each other.

[0025] In some embodiments, when the adjustment mechanism is adjusted to move the first end and the second end away from each other, the longitudinal guide element moves along the corresponding longitudinal guide channel, and the transverse guide element moves along the corresponding transverse guide channel, causing the movable plate to move inward toward the longitudinal axis of the base assembly.

[0026] In some embodiments, the adjustment mechanism includes a drive shaft that is threadedly engaged with the threaded shaft at the second end, and adjustment of the adjustment mechanism causes the drive shaft to be rotationally driven.

[0027] In some embodiments, the drive shaft comprises a hollow shaft having an internally threaded surface that threadably engages an externally threaded surface of the threaded shaft at the second end.

[0028] In some embodiments, the distal end of the threaded shaft at the second end portion is received in the non-threaded region of the hollow shaft and expands outward to prevent the drive shaft from being separated from the threaded shaft at the second end portion.

[0029] In some embodiments, the first end of the base assembly includes a ratchet element that engages a toothed surface of the drive shaft to allow the drive shaft to rotate in a direction that moves the first and second ends closer together and restricts rotation in an opposite direction.

[0030] In some embodiments, the ratchet element includes a spring element disposed in a groove in the first end portion, the groove providing clearance for the spring element to move along the toothed surface when the drive shaft rotates in a rotational direction that causes the first and second ends to approach each other.

[0031] In some embodiments, the threaded shaft and the second end portion are an integral structure, or the threaded shaft is disposed in and retained in the hole of the second end portion.

[0032] In some embodiments, the threaded shaft is non-rotatably mounted in the hole of the second end portion via a locking ring or a C-ring; or, one end of the threaded shaft located in the hole of the second end portion is non-circular.

[0033] The present invention also provides an expandable vertebral body device, comprising:

[0034] a base assembly comprising a first end portion and a second end portion, wherein the first end portion and the second end portion are movable relative to each other by adjusting an adjustment mechanism of the first end portion;

[0035] a plurality of movable panels movably disposed on the base assembly, the movable panels being movable at least longitudinally relative to the base assembly when the first end portion and the second end portion are moved relative to each other;

[0036] The first end portion and the second end portion each include a pair of longitudinal guide elements located at upper and lower sides of the respective end portions, and a pair of transverse guide elements located at opposite transverse sides of the respective end portions;

[0037] The plurality of movable panels each include a longitudinal guide surface along which the longitudinal guide member moves; the plurality of movable panels each include a transverse guide surface along which the transverse guide member moves;

[0038] When the adjustment mechanism is adjusted to bring the first end and the second end closer together, the guide element moves along the corresponding guide surface, and the movable plate can move longitudinally at least outward from the longitudinal axis of the base assembly.

[0039] In some embodiments, the multiple movable plates include a first group of plates and a second group of plates, respectively. The first group of plates and the second group of plates both include an upper plate and a lower plate. When the first end and the second end are brought closer together by adjusting the adjustment mechanism, the first group of plates and the second group of plates will be separated laterally, and the upper plate and the lower plate will be separated longitudinally.

[0040] In some embodiments, the upper plate is movably connected to the lower plate by a longitudinal connector that maintains the upper plate and the lower plate in transverse alignment while allowing the upper plate and the lower plate to move longitudinally relative to each other.

[0041] In some embodiments, when the adjustment mechanism is adjusted to separate the first end and the second end, the guide element moves along the corresponding guide surface to move the movable plate inwardly toward the longitudinal axis of the base assembly.

[0042] In some embodiments, the longitudinal guiding elements on the upper and lower sides of the first end and the second end form a longitudinal guiding channel, which can movably accommodate the longitudinal guiding elements on the corresponding movable plate, and the longitudinal guiding elements of the movable plate include corresponding longitudinal guiding surfaces; the transverse guiding elements on the upper and lower sides of the first end and the second end form a transverse guiding channel, which can movably accommodate the transverse guiding elements on the corresponding movable plate, and the transverse guiding elements on the movable plate include corresponding transverse guiding surfaces.

[0043] In some embodiments, the upper and lower sides of the first end and the second end are inclined surfaces, the longitudinal guide element is arranged parallel to the inclined surfaces and connected to the inclined surfaces through a connecting portion, and a longitudinal guide channel is formed between the longitudinal guide element and the inclined surfaces.

[0044] In some embodiments, sliding groove structures are provided at both side edges of the upper and lower inclined surfaces of the first end and the second end to form the transverse guide channel.

[0045] In some embodiments, the adjustment mechanism includes a drive shaft, which is threadedly engaged with the threaded shaft at the second end, and the drive shaft can be rotationally driven by adjusting the adjustment mechanism.

[0046] In some embodiments, the drive shaft comprises a hollow shaft having an internally threaded surface that threadably engages an externally threaded surface of the threaded shaft at the second end.

[0047] In some embodiments, the drive shaft has at least one through-hole, and when the expandable vertebral body device is implanted in a patient and at least partially expanded, bone growth material can enter the patient through the hollow shaft and the at least one through-hole.

[0048] In some embodiments, the first end of the base assembly includes a ratchet element that engages with a toothed surface of the drive shaft to allow the drive shaft to rotate in a direction that moves the first and second ends toward each other and restricts rotation in an opposite direction.

[0049] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0050] The expandable cone device provided by this invention is suitable for minimally invasive surgery. It allows for access to the vertebral body with a smaller size, eliminating the need to expand adjacent vertebrae too far apart. This reduces the excessive intraoperative traction on muscles, nerves, and the dura mater during traditional fusion cage implantation, which can lead to postoperative lumbar muscle pain and dysfunction. The expansion size can be adjusted as needed, eliminating the need for repeated insertion of a trial mold into the intervertebral space, minimizing damage to surrounding anatomical structures and shortening surgical time. The device is quick and easy to operate, and its integrated automatic locking function allows the surgeon to gradually expand the intervertebral height to the appropriate level based on the patient's clinical needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The above and other features and advantages of the present invention will be more clearly understood through the following detailed description in conjunction with the accompanying drawings, in which:

[0052] Figure 1 A perspective view of an expandable intervertebral body fusion cage or intervertebral body device is shown. The cage / intervertebral body device comprises a plurality of plates movably mounted on a base assembly. The plates are movable laterally and longitudinally relative to the base assembly according to the principles described herein. The illustration shows the expanded intervertebral body fusion cage or intervertebral body device in a collapsed state.

[0053] Figure 2 yes Figure 1 Another view of the device shown, shown in the expanded state;

[0054] Figure 3 yes Figure 1 A schematic diagram of the device from another perspective, shown in a retracted state;

[0055] Figure 4 yes Figure 2 A schematic diagram of the device from another perspective, shown in an expanded state;

[0056] Figure 5 This is an exploded perspective view of the device;

[0057] Figure 6 is with Figure 1 A similar diagram, but with the upper and lower plates on one side removed to show more detail;

[0058] Figure 7 is with Figure 2A similar diagram, but with the upper and lower plates on one side removed to show more detail;

[0059] Figure 8 is with Figure 6 A similar schematic, but with the upper plate removed to show more detail;

[0060] Figure 9 is an enlarged partial cross-sectional view of the device;

[0061] Figure 10A and 10B Shown is a view of the device in a collapsed state;

[0062] Figure 11A and 11B The device is shown in an expanded state;

[0063] Figure 12 It is another type of expandable vertebral device, and the device is shown in the collapsed state.

[0064] Figure 13 yes Figure 12 Another schematic diagram of the device shown, shown in an expanded state;

[0065] Figure 14 yes Figure 12 Another perspective view of the device shown, with one end removed to show more detail;

[0066] Figure 15 yes Figure 14 an end view of the device shown;

[0067] Figure 16 yes Figure 12 perspective and cross-sectional views of the illustrated apparatus;

[0068] Figure 17 is a side view of a plate of the device;

[0069] Figure 18 yes Figure 17 Another perspective of the plate shown;

[0070] Figure 19 and 20 This is a perspective view of the tail end of the device;

[0071] Figure 21 yes Figure 19 and Figure 20 Medial view of the caudal end shown;

[0072] Figure 22 It is a perspective view of the device, with some plates removed to show more details;

[0073] Figure 23 is a perspective view of the longitudinally and transversely expandable and contractible vertebral fusion cage or vertebral body device, shown in a contracted state;

[0074] Figure 24 is another perspective view of the longitudinally and transversely expandable and retractable cage or device for expanding intervertebral body fusion device, shown in an expanded state;

[0075] Figure 25 yes Figure 23 A side view of the device in a collapsed state;

[0076] Figure 26 yes Figure 24 A side view of the device in an expanded state;

[0077] Figure 27 and 28 yes Figure 23 Contralateral end view of the device in the retracted state;

[0078] Figure 29 and 30 yes Figure 24 Contralateral end view of the device in the expanded state;

[0079] Figure 31 yes Figure 23 A top view of the device in a retracted state;

[0080] Figure 32 yes Figure 24 A top view of the device in an expanded state;

[0081] Figure 33 is a side elevational view of a longitudinally expandable intervertebral fusion cage, the intervertebral fusion cage shown having an upper plate and a lower plate that can be moved relative to each other by an adjustment mechanism;

[0082] Figure 34 yes Figure 33 A top view of the longitudinally expandable intervertebral fusion cage is shown;

[0083] Figure 35 yes Figure 33 An end view of the longitudinally expandable intervertebral body fusion cage is shown;

[0084] Figure 36 yes Figure 33 An exploded view of the longitudinally expandable intervertebral fusion cage is shown;

[0085] Figure 37 yes Figure 33 Another exploded view of the longitudinally expandable intervertebral body fusion cage is shown with other components removed. DETAILED DESCRIPTION

[0086] The embodiments will now be described more fully with reference to the accompanying drawings. The embodiments are provided to ensure that the present application is more in-depth and will clearly convey the scope of the present application to those of ordinary skill in the art. This disclosure sets forth specific details, such as examples of specific components, devices, and methods, to facilitate the reader's comprehensive understanding of the configurations involved in this information disclosure. It will be apparent to those of ordinary skill in the art that the specific details need not be adopted, that the embodiments may be embodied in many different forms, and that the specific details and embodiments should not be construed as limiting the scope of the invention.

[0087] like Figures 1 to 4 As shown, a vertebral fusion cage or vertebral device (10) includes a plurality of plates or elements (12), which can be adjusted longitudinally and transversely relative to a base assembly (14) by adjusting the adjustment mechanism of the base assembly. The adjustment mechanism can be operated to move the first end (18) of the base assembly relative to the second end (20) of the base assembly, thereby causing the plates or elements (12) to move outwardly away from the central axis of the base assembly during device expansion, or to move the plates or elements (12) inwardly toward the central axis of the base assembly during device contraction, wherein the central axis of the base assembly is the longitudinal axis of the base assembly located in the direction connecting the first end and the second end, as described below.

[0088] In the illustrated embodiment, the adjustment mechanism includes a rotatable drive shaft (16) rotatably disposed at a first end portion (18) of the base assembly and rotatably engaged or threadedly engaged with a threaded shaft (30) at a second end portion (20) of the base assembly, wherein the base assembly central axis / the longitudinal axis of the base assembly is coaxially disposed with the drive shaft.

[0089] When the drive shaft (16) is rotated in one direction, the distance between the first end (18) and the second end (20) of the base assembly is shortened, thereby causing the plate (12) to move outward, away from the center axis or longitudinal axis of the base assembly, as described below. If the drive shaft (16) is rotated in the opposite direction, the distance between the first end (18) and the second end (20) of the base assembly is shortened, thereby causing the plate (12) to move inward, toward the center axis or longitudinal axis of the base assembly, as described below. The plate (12) includes four plates (22, 24, 26, 28) that are movable relative to each other and the base assembly.

[0090] like Figure 5As shown, the base assembly (14) includes a first end portion (18), a second end portion (20) and a drive shaft (16), wherein the drive shaft (16) is threadedly engaged with a threaded shaft (30) of the second end portion (20) through a hole at the first end portion (18). The drive shaft 16 is rotatably disposed on the first end portion (18) and longitudinally fixed therein, so that the drive shaft (16) can rotate relative to the first end portion (18) but will not move longitudinally relative to the first end portion (18) along the central axis. Figure 5 and 9 As shown, a locking ring or C-ring (32) is provided at the head (16a) of the drive shaft (16) and is located in a groove in the head (16a) and in a groove in the channel or hole of the first end (18), thereby fixing the shaft to the first end (18) while allowing the shaft to rotate relative to the first end (18). Therefore, if the drive shaft (16) rotates, the second end (20) will move relative to the first end (18), thereby achieving expansion and contraction of the intervertebral fusion cage or intervertebral device.

[0091] The drive shaft (16) comprises a hollow shaft with an internal thread, which is engaged with a threaded shaft (30) with an external thread. A through hole (16b) is provided on the top of the drive shaft (16) so that bone growth material (or bone filler) can be introduced into the hollow shaft (after the device is placed in an appropriate position in the patient's spine and partially expanded), so that the bone growth material can flow to an appropriate position in the patient's body through the through hole.

[0092] The first end portion (18) of the base assembly includes a ratchet pawl or ratchet element (34) that can engage with a gear on the head portion (16a) of the drive shaft (16). The ratchet pawl compresses the proximal tooth surface of the drive shaft through the ratchet pawl, thereby allowing the drive shaft (16) to rotate clockwise or counterclockwise, and a certain rotational force is required for rotation, so that when no external force is applied to the drive shaft (16) after expansion, each plate remains self-locked and does not collapse. The ratchet element (34) includes a flexible element that can be integrated with or become a part of the first end portion (18) and can bend relative to the main body of the first end portion (18) and the drive shaft (16), thereby allowing the drive shaft head to produce a ratchet-like effect in one direction. When the drive shaft attempts to rotate in the opposite direction, the element is restricted from bending by the end of the flexible element and / or the gear on the drive shaft head. Thus, when the device is extended to the expanded state, the drive shaft cannot easily rotate in the opposite direction to cause the device to retract after the device has been extended to the desired state, thereby maintaining the device in the set state while limiting or substantially preventing the drive shaft from accidentally retracting in the opposite direction. If sufficient torque is applied to the drive shaft head, the ratchet element allows the drive shaft head to rotate in the opposite direction, thereby adjusting the device to the compressed or retracted state if necessary to pull the plate toward the central axis of the base assembly.

[0093] like Figure 5 and 6 As shown, the first end portion (18) of the base assembly includes a longitudinal expansion ramp (18a) and a transverse expansion ramp (18b), which engage with the ramps on the corresponding panels. A longitudinal positioning element (18c) is also provided on the longitudinal expansion ramp (18a) of the first end portion (18), and a transverse positioning element (18d) is provided on the transverse expansion ramp (18b). The second end portion (20) includes a longitudinal expansion ramp (20a) and a transverse expansion ramp (20b), which engage with the ramps on the corresponding panels. A longitudinal positioning element (20c) is also provided on the longitudinal expansion ramp (20a) of the second end portion (20), and a transverse positioning element (20d) is provided on the transverse expansion ramp (20b).

[0094] like Figure 5 As shown, the positioning elements (18c, 18d, 20c, 20d) are inclined or angled elements that are spaced apart from the corresponding expansion ramps (18a, 18b, 20a, 20b). The expansion ramps and the surfaces facing the corresponding positioning elements form an angled gap or channel, that is, a longitudinal guide channel and a transverse guide channel for accommodating and guiding the panels therein. The angled surfaces of the positioning elements are parallel to the angled inclined surfaces of the ends, and the panels include guide elements with corresponding surfaces (described below), so that the panels can move along the surfaces during expansion and contraction of the device.

[0095] The plate (12) comprises a first set of plates and a second set of plates, wherein the first set of plates comprises a first upper plate and a first lower plate, and the second set of plates comprises a second upper plate and a second lower plate. Figure 5 As shown, the first upper plate is a convex end plate (22), the first lower plate is a concave end plate (24), the second upper plate is a concave end plate (28), and the second lower plate is a convex end plate (26).

[0096] Each plate has an outer surface (12a) for contacting the vertebra. The convex endplates (22, 26) include a protrusion (22a, 26a) extending from the plate and movably sliding into a recess (24a, 28a) of the concave endplates (24, 28). In the illustrated embodiment, the sets of plates are inverted so that the convex endplates (22) of one set of plates (22, 24) are positioned over the corresponding concave endplates (24), and the concave endplates (28) of the other set of plates (26, 28) are positioned over the corresponding convex endplates (26).

[0097] Each plate body is provided with a pair of channels at both ends, including a longitudinal positioning element guide channel (12b) and a transverse positioning element guide channel (12c). During the expansion and contraction of the device, the longitudinal positioning element guide channel (12b) can accommodate and guide the corresponding portion of the corresponding longitudinal positioning element. Similarly, during the expansion and contraction of the device, the transverse positioning element guide channel (12c) can accommodate and guide the corresponding portion of the corresponding transverse positioning element.

[0098] Each plate includes a longitudinal expansion ramp (12d) and a transverse expansion ramp (12e), which cooperate with the corresponding longitudinal expansion ramps (18a, 20a) and transverse expansion ramps (18b, 20b) on the first end and the second end (18, 20) of the base assembly. During the expansion process of the device, the longitudinal expansion ramps (18a, 20a) and the transverse expansion ramps (18b, 20b) on the first end and the second end (18, 20) cooperate with the longitudinal expansion ramps (12d) and the transverse expansion ramps (12e) on the corresponding plate to expand the device longitudinally and transversely, and the positioning elements (18c, 20c, 18d, 20d) move along the channel to make the plate close to the end (that is, to prevent the plate from moving out of the range allowed by the ramps 18a, 20a, 18b, 20b and the positioning elements 18c, 20c, 18d, 20d). During expansion or contraction of the device, the positioning elements (18c, 20c, 18d, 20d) move along the channel, thereby pulling the panels toward the central axis of the base assembly.

[0099] The boundaries of the longitudinal positioning element guide channel (12b) are formed by the inclined surface of the base portion of the plate body, and the side and corresponding angled surfaces or inclined surfaces of the longitudinal guiding element or member (12f) extending from the base portion of the plate body. The longitudinal guiding element or member (12f) is movable and is located between the opposite and parallel surfaces of the corresponding longitudinal positioning elements (18c, 20c) and the inclined rails (18a, 20a) of the corresponding ends (18, 20). During the expansion of the device, the inclined surfaces (18a, 20a) engage with the corresponding surfaces of the longitudinal guiding element or member (12f), forcing the plates apart, while during the contraction of the device, the inclined surfaces of the positioning elements (18c, 20c) engage with the opposite side surfaces of the longitudinal guiding element or member (12f), forcing the plates closer together.

[0100] Similarly, the boundaries of the transverse positioning element guide channel (12c) are formed by the inclined surface of the base portion of the plate body, and the side and corresponding angled surfaces or inclined surfaces of the transverse guiding element or member (12g) extending from the plate. The transverse guiding element or member (12g) is movably accommodated between the opposite and parallel surfaces of the corresponding transverse positioning element (18d, 20d) and the inclined surfaces (18b, 20b) on the corresponding end (18, 20). During the expansion of the device, the inclined surfaces (18b, 20b) engage with the corresponding surfaces (12e) of the transverse guiding element or member (12g), forcing the plates apart, while during the contraction of the device, the inclined surfaces of the positioning elements (18d, 20d) engage with the opposite side surfaces of the transverse guiding element or member (12g), forcing the plates closer together. The first upper plate is a convex end plate (22), the first lower plate is a concave end plate (24), the second upper plate is a concave end plate (28), and the second lower plate is a convex end plate (26).

[0101] The device (10) is implanted in the patient's body so that the upper surface (12a) of the convex end plate (22) and the concave end plate (28) are located at one vertebral body, and the lower surface (12a) of the concave end plate (24) and the convex end plate (26) are located at another vertebral body, and the device is located in the intervertebral space between the vertebral bodies. The device can be placed in an appropriate position in the intervertebral space by an instrument, and the base assembly can be provided with a connection or holding element or groove (12h) so that the instrument can grasp the device and move it to a specified position. After the device is placed in an appropriate position in the intervertebral space, the threaded drive shaft can be driven to rotate (such as by a hexagonal wrench or other suitable driving means) to pull the first end (18) and the second end (20) closer to each other, so that the plates move longitudinally and transversely until the device expands to the desired extent and contacts the upper and lower vertebral bodies.

[0102] By comparison Figure 1 and Figure 2 , Figure 3 and Figure 4 ,as well as Figure 6 and Figure 7It can be seen that when the second end portion (20) of the base assembly is pulled toward the first end portion (18) of the base assembly, the inclined or angled end portion (12d) of the panel moves along the longitudinally extending ramps (18a, 20a), causing the panel to move longitudinally, while the longitudinal positioning elements (18c, 20c) move along the channel (12b) (i.e., when the longitudinal guide elements (12f) of each panel move along the space or channel between the opposing surfaces of the ramps (18a, 20a) and the positioning elements (18c, 20c)). In this process, the inclined or angled surface (12e) of the panel guide element (12g) moves along the transversely extending ramps (18b, 20b), causing the panel to move laterally, while the transverse positioning elements (18d, 20d) move along the channel (12c) (i.e., when the transverse guide elements (12g) move along the space or channel between the opposing surfaces of the ramps (18b, 20b) and the positioning elements (18d, 20d)). During this process, the protrusions (22a, 26a) move relative to the recesses (24a, 28a) within the recesses, thereby achieving longitudinal expansion or separation of the panels while maintaining transverse alignment of the panels, bringing the panels together laterally. The longitudinal positioning elements (18c, 20c) are sufficiently wide that, when the panels are laterally expanded or moved outward from the base assembly, a portion of the longitudinal positioning elements can remain within the channel (12b), and the longitudinal guide elements (12f) remain within the space or channel between the ramps (18a, 20a) and the opposing surfaces of the positioning elements (18c, 20c). Similarly, the transverse positioning elements (18d, 20d) are sufficiently wide that, when the panels are longitudinally expanded or moved upward / downward from the base assembly, a portion of the transverse positioning elements can remain within the channel (12c), and the transverse guide elements (12g) remain within the space or channel between the ramps (18b, 20b) and the opposing surfaces of the positioning elements (18d, 20d). When the base assembly is retracted (the drive shaft rotates in the opposite direction), the positioning elements (18c, 20c, 18d, 20d) can pull the plate back toward the center axis of the base assembly, and the protrusions (22a, 26a) move relative to the recesses in the recesses (24a, 28a), and the control device is retracted or retracted.

[0103] Thus, during expansion and contraction of the device, the ramps and locating elements of the base assembly engage the channels and ramps of the corresponding panels, thereby causing the four panels to move longitudinally and laterally relative to the base assembly in a controlled manner, while also moving relative to each other, and the panels themselves interacting to move laterally together and longitudinally apart.

[0104] Although shown as an integral ratchet plate or ratchet arm or ratchet element (34), the intervertebral fusion device may be equipped with a spring element that engages with the toothed end of the drive shaft to allow the drive shaft to rotate in one direction (relative to the end) and to limit or prevent the shaft from rotating in the opposite direction. Figure 12-16As shown, a telescopic vertebral fusion cage or vertebral device (110) includes ends (118, 120) having a drive shaft (116) with a head (116a) having a gear or protrusion. Figure 23-32 Another expandable vertebral body device (110') is shown, wherein components are similar or identical and are numbered the same as those in the figure. Figure 12-22 Similarly, the end portion (118) includes a groove or channel (136) in which a spring element (134) is located, the spring element having a tooth or protrusion that meshes with the geared shaft head (116a).

[0105] like Figure 14-16 As can be clearly seen, the groove in the end portion (118) secures the spring element in position in the head portion (116a) and allows the central portion of the spring element (134) to be radially ( Figure 14-16 upwards), when the shaft moves in a certain direction (such as Figure 15 When the shaft portion (116) is rotated in the clockwise direction (in the middle), the gear or protrusion of the spring element can move along the inclined tooth surface of the head (116a) of the shaft portion (116) to expand the vertebral fusion cage under the action of the ratchet. Due to the shape of the gear of the head (116a), when this part of the shaft attempts to rotate in the opposite direction, the spring element will not move radially, so that the spring element can limit or prevent the shaft from rotating in the opposite direction (to prevent the vertebral fusion cage from collapsing). Therefore, the spring element can prevent accidental withdrawal of the shaft and loosening or shrinking of the vertebral fusion cage, but if the torque applied to the shaft head is large enough, the shaft head can rotate in the opposite direction (causing the vertebral fusion cage to collapse). The spring element (134) can include any suitable elastic material that allows bending or deflection and can return to its original state.

[0106] The expandable vertebral body device (110) is similar to the device (10) discussed above and includes opposing ends (118, 120) and a plurality of plates (112), including upper plates (122, 128) and lower plates (124, 126), which are movably disposed at the ends (118, 120) and are capable of contracting as the ends move away from or toward each other (see FIG. Figure 12 ) and extensions (see Figure 13 During this movement, the longitudinal guide elements or members (112f) of each upper and lower plate move along the upper and lower inclined surfaces (118a, 120a) (i.e., the longitudinal guide surfaces) at the end and move between the inclined surfaces (118a, 120a) and the corresponding upper and lower positioning elements (118c, 120c) in a similar manner as the device 10 discussed above. Similarly, during expansion or contraction, the transverse guide elements (112g) ( Figure 13 、 17The upper plates (122, 128) and their corresponding lower plates (124, 126) move laterally during expansion and contraction, through the engagement of the inclined surfaces and longitudinal connectors (122a, 124a and 126a, 128a), and between the opposing surfaces of the inclined surfaces (118b, 120b) and the corresponding lateral positioning elements (118d, 120d), similar to the movement of the device 10 discussed above.

[0107] Therefore, when the ends are brought together to expand the intervertebral fusion cage, the upper and lower inclined surfaces (118a, 120a) of the ends and the corresponding inclined outer surfaces of the longitudinal upper and lower positioning elements (118c, 120c) cooperate with the inclined surface of the longitudinal guide element (112f) and the inclined surface of the plate (for example, the inclined surface (118a) contacts and moves along the inclined surface (112d) of the longitudinal guide element (112f)), causing the plate to move longitudinally outward (upward and downward), while the side inclined surfaces (118b, 120b) of the ends engage with the inner inclined surface (112e) of the transverse guide element (112g), causing the plate to move laterally outward. Similarly, when the ends move away from each other to shrink the intervertebral fusion cage, the inner bevels (surfaces opposite to and separated from the bevels of the ends) of the longitudinal or upper and lower positioning elements (118c, 120c) cooperate with the inner bevels (surfaces opposite to and separated from the bevels of the plate body) of the longitudinal guide element (112f) to move the plate longitudinally inward (downward and upward), while the inner surfaces (surfaces opposite to and separated from the side bevels (118b, 120b) of the lateral positioning elements (118d, 120d)) cooperate with the outer bevels of the lateral guide element (112g) to move the plate laterally inward.

[0108] The ends (118, 120) are movable relative to each other by a rotatable drive shaft (116), which is movably disposed at the first end (118) of the base assembly, and the drive shaft is retained and radially constrained by a locking ring (132) located at a circumferential channel or groove formed in the longitudinal channel of the end and at a circumferential channel or groove formed around the head of the drive shaft, such as Figure 16As shown. The drive shaft (116) is rotatably engaged with, or threadedly engaged with, a threaded shaft (130) at the second end (120) of the base assembly. When the drive shaft (116) is rotated in one direction, the ends or wedges (118, 120) of the base assembly are pulled toward each other, causing the plates (122, 124, 126, 128) to move outward, away from the center or longitudinal axis of the base assembly. When the drive shaft is rotated in the opposite direction, the ends (118, 120) of the base assembly are moved away from each other, causing the plates to move inward, toward the center or longitudinal axis of the base assembly, as described below.

[0109] like Figure 16 As shown, the drive shaft (116) enters through a hole in the proximal end portion (118) and is threadedly engaged with the threaded shaft (130), which enters through a hole in the distal end portion (120) and is fixed to the end by a locking ring (133). The drive shaft (116) is rotatably arranged in the proximal end portion (118) and is longitudinally fixed therein by a locking ring or C-ring (132). The locking ring or C-ring (132) is arranged at the head (116a) of the shaft (116) and is located in a groove in the shaft head and a channel or groove in the proximal end portion (118) to fix the drive shaft to the proximal end portion while allowing the shaft to rotate relative to the proximal end portion. Another threaded shaft (130) is disposed at the distal end (120) and is longitudinally secured therein by a locking ring or C-shaped ring (133) disposed at the head or end (130a) of the threaded shaft (130) and positioned within a groove at the end of the shaft and within a groove in the channel or hole of the distal end (120) to secure the shaft to the distal end and restrict rotation of the shaft relative to the distal end. Optionally, as Figure 28 and 30 As shown, the head or end (130a') of the threaded shaft may also be non-circular and located at the end of the end portion (120) so as to be non-rotatably disposed at the end portion (or alternatively, the drive shaft may be integrally formed with the end portion).

[0110] The drive shaft (116) comprises a hollow shaft having an internal thread that engages with an external thread of a threaded shaft (130). The threaded end of the threaded shaft (130) engages with the thread of the threaded hollow end of the drive shaft (116), so that when the drive shaft (116) rotates, it moves along the threaded shaft (130), and the distal end moves relative to the proximal end, thereby achieving expansion and contraction of the vertebral fusion cage or vertebral device. Figure 16As shown, the internal thread (116c) of the drive shaft (116) ends at a certain distance from the shaft end, and the rest of the drive shaft (116) is unthreaded. The threaded portion (130b) of the threaded shaft (130) is threadedly connected to the hollow shaft (116), and the end (flared end 130c) of the threaded shaft (130) is radially expanded outward, so that the threaded shaft (130) has a larger diameter unthreaded end. The flared end (130c) can limit or prevent the drive shaft (116) from separating from the threaded shaft (130) because the flared end cannot pass through the internal thread (116c) portion of the drive shaft (116). Therefore, the flared end (130c) can limit the separation of the drive shaft and the end of the threaded shaft when the device is retracted, thereby preventing the device from being disassembled. The flared end of the threaded shaft (130) is formed after the threaded shaft is assembled, for example, by inserting a flared mandrel into the head (116a) of the drive shaft (116) and impacting the end of the threaded shaft (130).

[0111] Thus, through the interaction between the end portions and the plate ramps, the multiple plates of the interbody fusion cage can achieve longitudinal and / or lateral expansion. For example, an end portion or plate may include an inclined or angled element, which may include one or more inclined or angled surfaces, that interacts with one or more inclined or angled surfaces of another end portion or plate. Thus, when the end portion moves relative to the plates (e.g., when the end portions move toward each other), the interaction between the inclined or angled surfaces causes the plates to move outward both laterally and longitudinally, thereby achieving expansion of the interbody fusion cage. The plates can be retracted through the interaction between the inclined or angled element / surface of the end portion and another inclined or angled element / surface of the plate. Alternatively, expansion of the interbody fusion cage is achieved solely through the interaction of the corresponding inclined or angled surfaces (when the end portions move toward each other), while retraction of the interbody fusion cage can be achieved by any other suitable means. Thus, the end portion may include angled surfaces or ramps that interact with corresponding angled surfaces or ramps of the plate, thereby achieving longitudinal and lateral expansion of the interbody fusion cage as the end portion moves along the plate.

[0112] The guide elements and guide channels ensure that the plates and intervertebral fusion cage achieve the desired longitudinal and lateral expansion. The guide elements and guide channels form angles relative to the longitudinal axis of the end portion and the cage. For example, the greater the angle of the longitudinal guide channel and longitudinal guide element relative to the longitudinal axis, the greater the longitudinal movement of the plate when the end portion moves relative to each other. Similarly, the greater the angle of the transverse guide channel and transverse guide element relative to the longitudinal axis, the greater the lateral movement of the plate when the end portion moves relative to each other.

[0113] Alternatively, the transverse guide channels and transverse guide elements may be generally parallel to the longitudinal axis of the expandable cage, such that when the longitudinal guide elements move along the longitudinal guide channels (and the transverse guide elements move along the transverse guide channels), the plates may only move longitudinally relative to the ends. In such an arrangement, the upper plates may be connected together or form a single upper plate, and the lower plates may be connected together or form a single lower plate.

[0114] Therefore, the longitudinal guide element and the longitudinal guide channel can form a certain angle relative to the longitudinal axis of the expansion mechanism, which angle is greater than zero, for example, between about 15 degrees and 45 degrees, or about 30 degrees. The transverse guide element and the transverse guide channel can form any suitable angle, depending on the transverse expansion amplitude required for the specific vertebral fusion application environment. For example, the transverse guide element and the transverse guide channel can form a zero degree angle relative to the longitudinal axis of the expansion device (for a vertebral fusion device configuration that only allows longitudinal expansion), or form an angle greater than zero degree relative to the longitudinal axis of the expansion device, for example, between about 5 degrees and 30 degrees, or about 15 degrees (the amplitude of the lateral expansion is less than the amplitude of the longitudinal expansion).

[0115] Optionally, the expandable and retractable cage is longitudinally expanded by moving the longitudinal guide elements of the upper and lower plates along the angled channels or inclined channels at the ends without the transverse guide elements or transverse guide channels. Figures 33-37 As shown, the vertebral fusion cage (210) that can be longitudinally expanded and contracted includes end portions (218, 220), which are threadedly engaged with another threaded shaft of the end portion (220) by a threaded shaft (216) of the end portion (218), thereby achieving relative movement with each other, so that when the end portion moves, the upper plate (222) and the lower plate (224) are driven to move longitudinally. Similar to the vertebral fusion cages (10, 110, 110') discussed above, the end portions (218, 220) include upper and lower inclined surfaces (218a, 220a) and upper and lower positioning elements (218c, 220c) (channels are formed on both sides of the positioning elements and between the opposing surfaces of the inclined surfaces (218a, 220a) and the corresponding upper and lower positioning elements (218c, 220c)). The upper / lower plates (222, 224) include a pair of guide elements (212f) located between the channels at both ends of the positioning elements and the inclined surfaces (218a, 220a) and the corresponding upper and lower positioning elements (218c, 220c), and can also move along the above-mentioned space so as to longitudinally separate the end plates when the end portions (218, 220) approach each other.

[0116] The ends (218, 220) are mounted on corresponding threaded shafts (216, 230), with the threaded shaft (230) being threaded into a threaded receiver or shaft (216) so that when the threaded shaft (216) is rotated, the ends can be moved closer or further apart, similar to the movement described above. The threaded shaft (230) is fixedly disposed on the end (220), while the threaded shaft (216) (having a drivable head (216a) is rotatably disposed on the end (218) and passes through the end. In the illustrated embodiment, the end (218) includes a pair of channels that pass through the end transversely or crosswise and intersect with the longitudinal channel of the threaded shaft (216). The threaded shaft is inserted into the longitudinal channel of the end until a circumferential channel or groove (216d) formed on the head around the threaded shaft (216) is located at the channel, whereupon a pair of fixing pins (219) are inserted into the transverse channel and partially enter the groove (216d), thereby longitudinally fixing the threaded shaft (216) to the end (218) while allowing the threaded shaft (216) to rotate within the end (218). The length of the pin is limited so that the pin does not extend into the channel formed between the opposing surfaces of the inclined surfaces (218a, 220a) and the corresponding upper and lower positioning elements (218c, 220c) when inserted into the transverse channel.

[0117] The above description is for illustrative and descriptive purposes only. It is not intended to be exhaustive and does not affect the scope of this disclosure. Elements or functions of a particular configuration are generally not limited to that configuration, but, where appropriate, may be interchangeable and used in a selected configuration even if not specifically shown or described. Similarly, many aspects are subject to modification. Such modifications should not be considered a departure from the disclosure, and all such modifications are intended to be included within the scope of this disclosure.

Claims

1. An expandable vertebral body device, characterized in that: include: a base assembly including a first end portion and a second end portion, wherein the two ends are movable relative to each other by adjusting an adjustment mechanism of the first end portion; a plurality of movable panels movably disposed on the base assembly and movable at least longitudinally relative to the base assembly when the first end portion and the second end portion are moved relative to each other; Wherein, a longitudinal guide channel is provided in the central area of the upper side and the lower side of the first end portion and the second end portion respectively; Wherein, each of the plurality of movable panels is provided with at least one longitudinal guide element at its end, and each longitudinal guide element is movably accommodated in a longitudinal guide channel corresponding to the first end and the second end; at least one transverse guide channel is provided on each of the transverse opposite sides of the first end and the second end, and each of the plurality of movable panels is provided with a transverse guide element at its two ends, and each transverse guide element is movably located in a corresponding transverse guide channel in the first end and the second end; and, When the first end and the second end are brought closer together by adjusting the adjustment mechanism, the longitudinal guide element moves along the corresponding longitudinal guide channel, and the transverse guide element moves along the corresponding transverse guide channel, and the movable plate can move at least longitudinally outward from the longitudinal axis of the base assembly.

2. The expandable vertebral body device according to claim 1, characterized in that: Each of the longitudinal guide channels is located between an outer longitudinal inclined surface of the corresponding first end portion or second end portion main body portion and an inner inclined surface of a longitudinal positioning element protruding from the corresponding first end portion or second end portion main body portion.

3. The expandable vertebral body device according to claim 1, wherein: The transverse guide channel extends parallel to the longitudinal axis of the base assembly.

4. The expandable vertebral body device according to claim 1, wherein: The plurality of movable plates include an upper plate and a lower plate.

5. The expandable vertebral body device according to claim 1, wherein: Each of the longitudinal guide channels is located between the external longitudinal inclined surface of the corresponding first end or second end main body part and the internal inclined surface of the longitudinal positioning element protruding from the main body part of the corresponding first end or second end, and the transverse guide channel is located between the external transverse inclined surface of the corresponding first end or second end main body part and the internal inclined surface of the transverse positioning element protruding from the main body part of the corresponding first end or second end.

6. The expandable vertebral body device according to claim 5, wherein: When the adjustment mechanism is adjusted to bring the first end and the second end closer together, the inner slope of the longitudinal positioning element moves along the outer surface of the longitudinal guide element, and the inner slope of the transverse positioning element moves along the outer surface of the transverse guide element.

7. The expandable vertebral body device according to claim 6, wherein: When the adjustment mechanism is adjusted to move the first end and the second end away from each other, the outer longitudinal slope of the end body portion moves along the inner surface of the longitudinal guide element, and the outer transverse slope of the end body portion moves along the inner surface of the transverse guide element.

8. The expandable vertebral body device according to claim 1, wherein: The transverse guide channel forms a certain angle relative to the longitudinal axis of the base assembly, and when the longitudinal guide element moves along the corresponding longitudinal guide channel and the transverse guide element moves along the corresponding transverse guide channel, the movable plate can move longitudinally and transversely outward from the longitudinal axis of the base assembly.

9. The expandable vertebral body device according to claim 8, wherein: The multiple movable plates include a first group of plates and a second group of plates, respectively, wherein each group of plates includes an upper plate and a lower plate, respectively. When the adjustment mechanism is adjusted to bring the first end and the second end closer together, the first group of plates is separated laterally from the second group of plates, and the upper plate is separated longitudinally from the lower plate.

10. The expandable vertebral body device according to claim 9, wherein: The upper and lower plates are movably connected by longitudinal connectors that maintain transverse alignment of the upper and lower plates in the first and second sets of plates while allowing longitudinal movement of the upper and lower plates relative to each other.

11. The expandable vertebral body device according to claim 8, wherein: The plurality of movable plates include a first upper plate, a second upper plate, a first lower plate and a second lower plate.

12. The expandable vertebral body device according to claim 11, wherein: The longitudinal guide elements at both ends of the first upper plate and the second upper plate can be movably accommodated in the longitudinal guide channels corresponding to the upper sides of the first end and the second end, and the longitudinal guide elements at both ends of the first lower plate and the second lower plate can be movably accommodated in the longitudinal guide channels corresponding to the lower sides of the first end and the second end.

13. The expandable vertebral body device according to claim 12, wherein: The lateral guide elements at both ends of the first upper plate and the first lower plate are movably accommodated in the lateral guide channels of the first lateral side corresponding to the first end and the second end, and the lateral guide elements at both ends of the second upper plate and the second lower plate are movably accommodated in the lateral guide channels of the second lateral side corresponding to the first end or the second end.

14. The expandable vertebral body device according to claim 13, wherein: The first upper plate is movably connected to the first lower plate by a first longitudinal connecting element, which is used to maintain the first upper plate and the first lower plate in transverse alignment while allowing the first upper plate and the first lower plate to move longitudinally relative to each other.

15. The expandable vertebral body device according to claim 8, wherein: When the adjustment mechanism is adjusted to move the first end and the second end away from each other, the longitudinal guide element moves along the corresponding longitudinal guide channel, and the transverse guide element moves along the corresponding transverse guide channel, so that the movable plate moves inward toward the longitudinal axis of the base assembly.

16. The expandable vertebral body device according to claim 1, wherein: The adjustment mechanism includes a drive shaft that is threadedly engaged with the threaded shaft at the second end, and adjustment of the adjustment mechanism realizes rotational driving of the drive shaft.

17. The expandable vertebral body device according to claim 16, wherein: The drive shaft includes a hollow shaft having an internal threaded surface that threadably engages an external threaded surface of the threaded shaft at the second end.

18. The expandable vertebral body device according to claim 17, wherein: The end of the threaded shaft at the second end is accommodated in the non-threaded area of the hollow shaft and expands outward to prevent the driving shaft from being separated from the threaded shaft at the second end.

19. The expandable vertebral body device according to claim 16, wherein: The first end of the base assembly includes a ratchet element that engages with a toothed surface of the drive shaft to allow the drive shaft to rotate in a direction that brings the first and second ends closer together and restricts rotation in an opposite direction.

20. The expandable vertebral body device according to claim 19, wherein The ratchet element includes a spring element disposed in a groove of the first end portion, the groove providing clearance for the spring element to move along the toothed surface when the drive shaft rotates in a rotation direction that brings the first end portion and the second end portion closer together.

21. The expandable vertebral body device according to claim 16, wherein: The threaded shaft and the second end portion are an integral structure, or the threaded shaft is disposed in a hole in the second end portion and retained in the hole.

22. The expandable vertebral body device according to claim 21, wherein: The threaded shaft is non-rotatably mounted in the hole of the second end portion via a locking ring or a C-ring; Alternatively, the end of the threaded shaft located in the hole of the second end portion is non-circular.

23. An expandable vertebral body device, characterized in that: Include: a base assembly comprising a first end portion and a second end portion, wherein the first end portion and the second end portion are movable relative to each other by adjusting an adjustment mechanism of the first end portion; a plurality of movable panels movably disposed on the base assembly, the movable panels being movable at least longitudinally relative to the base assembly when the first end portion and the second end portion are moved relative to each other; The first end portion and the second end portion each include a pair of longitudinal guide elements located at upper and lower sides of the respective end portions, and a pair of transverse guide elements located at opposite transverse sides of the respective end portions; The plurality of movable panels each include a longitudinal guide surface along which the longitudinal guide member moves; the plurality of movable panels each include a transverse guide surface along which the transverse guide member moves; When the adjustment mechanism is adjusted to bring the first end and the second end closer together, the guide element moves along the corresponding guide surface, and the movable plate can move longitudinally at least outward from the longitudinal axis of the base assembly.

24. The expandable vertebral body device according to claim 23, wherein: The multiple movable plates include a first group of plates and a second group of plates, respectively. The first group of plates and the second group of plates both include an upper plate and a lower plate. When the first end and the second end are brought closer together by adjusting the adjustment mechanism, the first group of plates and the second group of plates will be separated horizontally, and the upper plate and the lower plate will be separated longitudinally.

25. The expandable vertebral body device according to claim 24, wherein: The upper plate and the lower plate are movably connected by a longitudinal connector, which maintains the upper plate and the lower plate in transverse alignment while allowing the upper plate and the lower plate to move longitudinally relative to each other.

26. The expandable vertebral body device according to claim 23, wherein: When the adjustment mechanism is adjusted to move the first end and the second end away from each other, the guide element moves along the corresponding guide surface to move the movable plate inwardly toward the longitudinal axis of the base assembly.

27. The expandable vertebral body device according to claim 23, wherein: The longitudinal guide elements on the upper and lower sides of the first end and the second end form a longitudinal guide channel, which can movably accommodate the longitudinal guide elements on the corresponding movable plate, and the longitudinal guide elements of the movable plate include corresponding longitudinal guide surfaces; the transverse guide elements on the upper and lower sides of the first end and the second end form a transverse guide channel, which can movably accommodate the transverse guide elements on the corresponding movable plate, and the transverse guide elements on the movable plate include corresponding transverse guide surfaces.

28. The expandable vertebral body device according to claim 27, wherein: The upper and lower sides of the first end and the second end are inclined surfaces. The longitudinal guiding element is arranged parallel to the inclined surfaces and is connected to the inclined surfaces through a connecting portion. A longitudinal guiding channel is formed between the longitudinal guiding element and the inclined surfaces.

29. The expandable vertebral body device according to claim 28, wherein: Slide groove structures are provided at both side edges of the upper and lower inclined surfaces of the first end and the second end to form the transverse guide channel.

30. The expandable vertebral body device according to claim 23, wherein The adjustment mechanism includes a driving shaft, which is threadedly engaged with the threaded shaft at the second end. The driving shaft can be rotationally driven by adjusting the adjustment mechanism.

31. The expandable vertebral body device according to claim 30, wherein: The drive shaft includes a hollow shaft having an internal threaded surface that threadably engages an external threaded surface of the threaded shaft at the second end.

32. The expandable vertebral body device according to claim 31, wherein: The drive shaft has at least one through-hole, and when the expandable vertebral body device is implanted in the patient and at least partially expanded, bone growth material can enter the patient through the hollow shaft and the at least one through-hole.

33. The expandable vertebral body device according to claim 32, wherein: The first end portion of the base assembly includes a ratchet element that engages with a toothed surface of the drive shaft to allow the drive shaft to rotate in a direction in which the first and second ends approach each other and restrict rotation in an opposite direction.

34. The expandable vertebral body device according to claim 30, wherein: The threaded shaft and the second end portion are an integral structure, or the threaded shaft is disposed in a hole in the second end portion and retained in the hole.

35. The expandable vertebral body device according to claim 34, wherein: The threaded shaft is non-rotatably mounted in the hole of the second end portion via a locking ring or a C-ring; Alternatively, the end of the threaded shaft located in the hole of the second end portion is non-circular.

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