Height Adjustable Spinal Fusion Cage

Abstract

This spinal fusion cage is inserted between vertebrae at a minimum height and can be adjusted in height while inserted. Its fixation strength is improved by bone screws inserted through the end plates, allowing a single cage to replace cages with a certain range of heights. This reduces the number of products that manufacturers must produce and reduces inventory. Furthermore, unlike conventional cages with preset heights at fixed intervals, this cage's height is linearly adjusted according to the spacing of the patient's vertebrae, allowing surgery to be performed at the optimal height for the patient's condition.

Description

[Technical field]

[0001] The present invention relates to a height-adjustable spinal fusion cage, and more particularly, to a spinal fusion cage that can be inserted between vertebral bodies at a minimum height and has an adjustable height while inserted, and in particular, has improved fixation strength by bone screws inserted through end plates. [Background technology]

[0002] The vertebral body is made up of 32 to 35 vertebrae that make up the torso and the intervertebral disks between the vertebrae, and is the central part of the human body that connects the skull at the top and the pelvis at the bottom.

[0003] The spine consists of seven cervical vertebrae, 12 thoracic vertebrae, five lumbar vertebrae, five sacrum vertebrae, and three to five coccyx vertebrae. In adults, five sacral vertebrae are fused to form one sacrum, and three to five coccyx vertebrae are fused to form one coccyx.

[0004] Spinal fusion has long been one of the treatment methods for serious spinal diseases. Spinal fusion is a surgical procedure that removes the intervertebral disc and inserts a cage to fuse the adjacent vertebrae together.

[0005] When spinal fusion is performed on the lumbar spine, it can be classified into posterior lumbar interbody fusion (PLIF), transformational lumbar interbody fusion (TLIF), lateral lateral lumbar interbody fusion (LLIF), oblique lumbar interbody fusion (OLIF), anterior lumbar interbody fusion (ALIF), etc., depending on the direction of cage insertion.

[0006] Posterior interbody fusion (PLIF) involves making an incision along the centerline of the spine, opening it to expose the entire vertebral body, removing part of the posterior side of the vertebra, removing the disc, and inserting a PLIF cage.

[0007] Posterior interbody fusion (PLIF) is the oldest spinal fusion procedure and is a necessary method when fusing two or three joints. However, it has the disadvantages of a high possibility of adhesions occurring to nerves, ligaments, and muscles during the surgery, a long healing time due to the large incision area, and serious aftereffects in some people.

[0008] The PLIF cage consists of a pair of small cages placed on either side of the bone and is the smallest of all cages used in spinal fusion surgery.

[0009] Transverse foraminal lumbar fusion (TLIF) is a surgical method in which small incisions are made along both sides of the spinal muscles to expose the vertebral body to a minimum extent, and then the spinal joint area is removed in the direction of the neural foramen and a TLIF cage is inserted. This surgical technique has the advantages of less bleeding and shorter surgery time, so it is suitable for surgery on one joint, but if surgery is required on multiple areas, a PLIF operation must be performed. Most TLIF cages are arc-shaped, so they are inserted into the vertebral body and rotated so that the bulging part of the TLIF cage faces the ventral side. The TLIF cage is larger than the PLIF cage, but its support area is smaller than the LLIF cage or ALIF cage, which will be explained later.

[0010] Anterior lumbar interbody fusion (ALIF) has many advantages, such as quick recovery and no worries about adhesions, but it has the disadvantage of requiring highly skilled techniques to perform the procedure by making an incision on the front (ventral side) and approaching the spine while turning over the internal organs. The ALIF cage has the advantage of having the largest support area of ​​all spinal fusion cages.

[0011] Among such ALIF cages, an integrated cage with holes through which screws can be inserted and fixed into the vertebral body to prevent the cage from coming off after surgery has been disclosed (Patent Document 3: US2014-0277487A).

[0012] Patent documents 1-2: US9585762 and US2019-0133782A disclose a free-standing ALIF cage with adjustable height. However, Patent document 1: US9585762 adjusts the height using a vertical ratchet 302, and is characterized by essentially adjusting the angle rather than the height. Patent document 2: US2019-0133782A adjusts the height, but has a problem of being difficult to manufacture due to its very complicated structure. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] US9585762 [Patent Document 2] US2019-0133782A [Patent Document 3] US2014-0277487A Summary of the Invention [Problem to be solved by the invention]

[0014] The present invention has been devised to solve the above-mentioned problems, and aims to provide a spinal fusion cage that can be inserted between vertebral bodies at a minimum height, can adjust the height while inserted, and can stably support the movement of a pair of end plates. [Means for solving the problem]

[0015] In order to achieve the above-mentioned object, the present invention provides a spinal fusion cage comprising: a first endplate and a second endplate for contacting adjacent vertebrae; a distal moving block connected to distal portions of the first endplate and the second endplate so as to be movable relative to the distal moving block; a proximal moving block connected to proximal portions of the first endplate and the second endplate so as to be movable relative to the distal moving block; an adjustment member capable of adjusting the distance between the proximal moving block and the distal moving block by rotating the adjustment member; and vertical guide members disposed on the first endplate and the second endplate and formed to support loads in the length direction or width direction of the first endplate and the second endplate, wherein the distal moving block and the proximal moving block are formed with block sliders, and the first and second endplates are formed with plate sliders that slide relative to the block sliders, and the distance in the width direction of the block slider of the distal moving block from the axis of the adjustment member is longer than the distance in the width direction of the block slider of the distal moving block from the axis of the adjustment member.

[0016] A block auxiliary slider is disposed around the end moving block, and the first and end plates are formed with plate auxiliary sliders that slide on the auxiliary block slider.

[0017] The block auxiliary slider is characterized in that it is disposed at an end in the width direction of the terminal moving block.

[0018] The block auxiliary slider is disposed in a direction opposite to the block slider.

[0019] The adjustment member may have a threaded portion at one end that is threadedly coupled to the distal moving block, and a rotation support seat at the other end that is fixed rotatably relative to the proximal moving block, and the rotation support member may be positioned at the rotation support seat through the proximal moving block.

[0020] In addition, the vertical guide portion includes a first vertical guide formed in a thickness direction of the first end plate or the second end plate, and a second vertical guide formed in the thickness direction of the first end plate or the second end plate and performing a sliding motion with the first vertical guide, and two pairs of the vertical guides are arranged, one pair of the vertical guides is arranged on one side of the width direction of the first end plate and the second end plate, and the other pair of the vertical guides is arranged on the other side of the width direction of the first end plate and the second end plate.

[0021] The first vertical guide may be a pillar protruding in a thickness direction of the first or second end plate, and the second vertical guide may have a channel surrounding a portion of an outer surface of the pillar.

[0022] The channel is also characterized in that it is formed by a first groove portion that is recessed in the width direction of the first or second end plate, and a second groove portion that is formed by an extension portion that protrudes from the groove portion in the thickness direction of the first or second end plate.

[0023] The pillar may be provided with a receiving portion around the pillar for receiving the extension portion.

[0024] The first groove portion is formed to be recessed by a first groove wall disposed on the proximal side, a second groove wall disposed on the distal side spaced apart from the first groove wall, and a third groove wall connecting the first groove wall and the second groove wall.

[0025] The width direction thickness of the pillar is the same as the width direction depth of the first groove portion, and the length direction thickness of the pillar is the same as the length direction distance between the first groove wall and the second groove wall.

[0026] The second groove portion is formed by an extension portion consisting of a first extension wall protruding in a thickness direction of the first or second end plate and positioned on the proximal side, a second extension wall protruding in the thickness direction of the first or second end plate and positioned on the distal side, and a third extension wall protruding in the thickness direction of the first or second end plate connecting the first extension wall and the second extension wall, wherein the first extension wall forms a plane with the first groove wall, the second extension wall forms a plane with the second groove wall, and the third extension wall forms a plane with the third groove wall.

[0027] The second groove portion has a width direction depth smaller than a width direction depth of the first groove portion.

[0028] In addition, a guide groove for guiding the insertion of the pillar is formed around the first groove portion.

[0029] The sum of the lengthwise thicknesses of the first extension wall and the second extension wall is greater than or equal to the lengthwise thickness of the pillar.

[0030] The third extension wall has a widthwise thickness equal to that of the pillar.

[0031] The first and second end plates each have a through hole formed in a side thereof.

[0032] The first or second end plate may further include a center groove disposed at a proximal end thereof.

[0033] The proximal moving block may be provided with a cover member.

[0034] The cover member may include a cover plate that covers the center groove, and a cover bolt that penetrates the cover plate and is fixed to the proximal moving block.

[0035] The cover plate is also characterized in that a gripping groove is formed in the cover plate for gripping.

[0036] The proximal moving block may further include a bone screw inserted through a bone screw hole formed in the first end plate and the second end plate; and a locking member fastened to the proximal moving block to prevent the bone screw from coming off.

[0037] The locking member may include a locking plate that covers the bone screw, and a locking bolt that passes through the locking plate and is fixed to the proximal moving block, and the proximal moving block may be provided with a locking bolt fastening portion at a front end of the adjustment member to which the locking bolt may be coupled.

[0038] The lock plate may have a lock protrusion at a rear end thereof protruding toward the bone screw.

[0039] The lock bolt is characterized in that it comes into contact with and biases the adjustment member when coupled. Effect of the Invention

[0040] The present invention can replace cages having a certain range of heights with one cage. Therefore, the number of products that manufacturers must produce is reduced, and inventory can be reduced. Also, unlike the conventional cages with a preset height at a certain interval, the height is linearly adjusted according to the interval between the vertebrae of the patient, so surgery can be performed at the optimal height according to the patient's condition.

[0041] In addition, because the cage is inserted at the minimum height, it reduces the burden of having to separately produce test inserts to match the existing appropriate vertebral spacing, and it also reduces the trouble for doctors who have to secure insertion space by sequentially inserting multiple test inserts. [Brief description of the drawings]

[0042] [Figure 1] FIG. 2 is a perspective view of the front surface of a spinal fusion cage according to the present invention in a minimum height state, as viewed from above. [Diagram 2] FIG. 2 is a top-down perspective view of the rear of the spinal fusion cage of FIG. [Diagram 3] FIG. 2 is a perspective view of the front surface of the first embodiment in the maximum height state as viewed from above. [Figure 4] FIG. 4 is a top-down perspective view of the rear of the spinal fusion cage of FIG. [Diagram 5] FIG. 4 is a top front perspective view of the spinal fusion cage in the state of FIG. 3 with a cover plate attached. [Figure 6] FIG. 4 is a front, top perspective view of the spinal fusion cage of FIG. 3 with bone screws inserted around the center groove. [Figure 7] FIG. 7 is a front, upper perspective view of the spinal fusion cage in the state of FIG. 6 with a cover plate attached. [Figure 8] FIG. 2 is an exploded perspective view of the front surface of the spinal fusion cage of Example 1, viewed from above. [Figure 9] FIG. 2 is an exploded perspective view of the rear surface of the spinal fusion cage of Example 1 as viewed from above. [Figure 10]4 is a perspective view of the front surface of the first end plate according to the first embodiment as viewed from above. FIG. [Figure 11] 8 is a perspective view of the rear surface of the first end plate of FIG. 7 as viewed from below. FIG. [Figure 12] 4 is a perspective view of the front surface of the second end plate of the first embodiment as viewed from above. FIG. [Figure 13] 13 is a perspective view of the rear surface of the second end plate of FIG. 12 as viewed from below. FIG. [Figure 14] 13 is a partial enlarged view of the vertical guide of the second end plate of FIG. 12. FIG. [Figure 15] FIG. 2 is a perspective view of the front surface of the proximal moving block of the first embodiment, seen from above. [Figure 16] FIG. 16 is a top perspective view of the rear face of the proximal movement block of FIG. [Figure 17] This is an oblique view of the front surface of the end moving block of Example 1 seen from above. [Figure 18] FIG. 18 is a top-down perspective view of the rear face of the distal moving block of FIG. 17; [Figure 19] FIG. 2 is a perspective view of an adjustment member according to the first embodiment. [Figure 20] FIG. 2 is an exploded perspective view of the cover member of the first embodiment. [Figure 21] FIG. 2 is a perspective view of the screw of Example 1. [Figure 22] From the upper side of the front of the embodiment of the spinal fusion cage according to the second embodiment of the present invention in the lowest height state [Figure 23] FIG. 2 is a top-down perspective view of the rear of the spinal fusion cage of FIG. [Figure 24] FIG. 11 is a perspective view of the front surface of the second embodiment in the maximum height state as viewed from above. [Diagram 25] FIG. 4 is a top-down perspective view of the rear of the spinal fusion cage of FIG. [Figure 26] FIG. 11 is an exploded perspective view of the front of the spinal fusion cage of Example 2, viewed from above. [Figure 27] FIG. 11 is an exploded perspective view of the rear surface of the spinal fusion cage of Example 2, viewed from above. [Figure 28]FIG. 13 is a perspective view of the lock plate of the spinal fusion cage of the second embodiment being coupled. [Figure 29] FIG. 11 is a perspective view of the front surface of the first end plate of the second embodiment as viewed from above. [Diagram 30] 30 is a perspective view of the rear surface of the first end plate of FIG. 29 viewed from below. FIG. [Diagram 31] FIG. 11 is a perspective view of the front surface of the second end plate of the second embodiment as viewed from above. [Diagram 32] 32 is a perspective view of the rear surface of the second end plate of FIG. 31 as viewed from below. FIG. [Diagram 33] 32 is a partial enlarged view of the second end plate of FIG. 31. FIG. [Diagram 34] FIG. 11 is a perspective view of the front surface of the proximal moving block of the second embodiment, seen from above. [Diagram 35] FIG. 35 is a top, rear perspective view of the proximal movement block of FIG. 34. [Diagram 36] This is an oblique view of the front surface of the end moving block of Example 2, seen from above. [Figure 37] FIG. 37 is a top-down perspective view of the rear face of the distal moving block of FIG. 36; [Figure 38] FIG. 11 is a perspective view of an adjustment member according to a second embodiment. [Figure 39] FIG. 11 is a perspective view of the front surface of the lock plate of the second embodiment as viewed from above. [Diagram 40] FIG. 40 is a perspective view of the rear surface of the lock plate of FIG. 39 as seen from above. [Diagram 41] FIG. 11 is a perspective view of the front surface of the lock bolt of the second embodiment as viewed from above. [Diagram 42] FIG. 1 is a perspective view of a bone screw according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] Hereinafter, the present invention will be described with reference to the drawings in which preferred embodiments are attached. In the following drawings, when reference numerals are used to designate components, the same reference numerals are used as much as possible even if the same components are displayed in different drawings, and detailed descriptions of known functions and configurations that are considered to be likely to unnecessarily obscure the gist of the present invention will be omitted.

[0044] The directions used in the following description are defined. The distal direction is the direction in which the spinal fusion cage is inserted, and the proximal direction is the opposite direction to the distal direction. The length direction refers to the direction on an imaginary straight line connecting the distal direction and the proximal direction. The thickness direction refers to the thickness direction of the endplate, i.e., the imaginary straight line direction toward the upper and lower vertebrae. The width direction refers to the direction perpendicular to both the length direction and the thickness direction, and refers to the horizontal direction of the endplate.

[0045] Figures 1 to 9 show an entire spinal fusion cage 100 according to a first embodiment, and Figures 8 to 21 show each component of the spinal fusion cage 100. Figures 22 to 28 show an entire spinal fusion cage 300 according to a second embodiment, and Figures 29 to 42 show each component of the spinal fusion cage 300.

[0046] The spinal fusion cage 100 of the first embodiment and the spinal fusion cage 300 of the second embodiment are the same except for the parts related to the bone screws. Therefore, the spinal fusion cage 100 of the first embodiment and the spinal fusion cage 300 of the second embodiment will be described at the same time, and then the differences will be described.

[0047] The spinal fusion cage 100, 300 includes a first end plate 102, 302 and a second end plate 104, 304 arranged to face each other vertically, a distal moving block 108, 308 and a proximal moving block 106, 306 arranged between the first end plate 102, 302 and the second end plate 104, 304 and moved depending on the distance between the first end plate 102, 302 and the second end plate 104, 304, and an adjustment member 110, 310 that penetrates the proximal moving block 106, 306 and connects to the distal moving block 108, 308.

[0048] The vertical guide portions are disposed on the first end plates 102, 302 and the second end plates 104, 304 and are formed to support loads in the length direction or width direction of the first end plates 102, 302 and the second end plates 104, 304.

[0049] The first end plate 102, 302 and the second end plate 104, 304 have a first plate body 122, 322 and a second plate body 146, 346 having teeth on the surface that contacts the vertebral body. The teeth are formed to prevent the vertebral body from coming off, and can be deformed in various ways. In addition, the first plate body 122, 322 and the second plate body 146, 346 have a first window 145, 345 and a second window 172, 372 formed in the center thereof for inserting a bone graft.

[0050] 10 and 11 or 29 and 30, the first plate body 122, 322 is formed with a proximal moving block seat 130, 330 in the proximal direction along the length direction, and a distal moving block seat 138, 338 in the distal direction. A plate inclined portion 128, 328 is formed extending to the proximal moving block seat 130, 330, and a pair of plate sliders 132, 332 are formed facing each other on both sides of the plate inclined portion 128, 328.

[0051] Similarly, as shown in Figures 12 and 13 or Figures 31 and 32, the second plate body 146, 346 is formed with a proximal moving block seat 156, 356 in the proximal direction along the length direction, and a distal moving block seat 164, 364 in the distal direction. A plate inclined portion 154, 354 is formed extending from the proximal moving block seat 156, 356, and a pair of plate sliders 158, 358 are formed facing each other on both sides of the plate inclined portion 154, 354.

[0052] Plate inclined portions 139, 165, 339, 365 are formed around the end moving block seats 138, 156, 338, 356. The plate inclined portions 139, 165, 339, 365 are formed on both ends of the end moving block seats 138, 164, 338, 364, and plate sliders 142, 168, 342, 368 are formed on the outer sides of the plate inclined portions 139, 165, 339, 365. In addition, plate auxiliary sliders 144, 170, 344, 370 may be formed on the outer sides of the plate sliders 142, 168, 342, 368 to face the plate sliders 142, 168, 342, 368.

[0053] When the spinal fusion cage 100, 300 is used in ALIF, the first end plate 102, 302 and the second end plate 104, 304 are formed to be thicker on the proximal side than on the distal side due to the structure of the spine. Therefore, when a load is applied in the thickness direction, width direction, or length direction, the flow of stress may be concentrated on the distal side where the thickness is relatively thin. Therefore, it is preferable to add the plate auxiliary slider 144, 170, 344, 370 to make the stress distribution uniform.

[0054] The plate sliders 132, 158, 332, 358 formed in the proximal portion and the plate sliders 142, 168, 342, 368 formed in the distal portion are formed to be inclined in a direction approaching the center of the first plate body 122, 322 or the second plate body 146, 346 as they go in the thickness direction from the surface of the first plate body 122, 322.

[0055] In addition, plate auxiliary supports 133, 157, 333, 357 are formed around the outer periphery in the width direction of the plate slider 132, 158, 332, 358 formed in the proximal portion. The plate auxiliary supports 133, 157, 333, 357 and the block auxiliary supports 181, 381 of the proximal moving block 106 increase the support area, so that the load can be transmitted more stably.

[0056] In addition, reinforcing ramp seats 140, 166, 340, 366 are formed extending to the seats 138, 164, 338, 364 of the end moving blocks. The reinforcing ramp seats 140, 166, 340, 366 can accommodate reinforcing ramps 200, 400, which will be described below, and prevent the reinforcing ramps 200, 300 from being interfered with by the first plate body 122, 322 or the second plate body 146, 346 when the end moving blocks 108, 308 move.

[0057] Also, first side holes 123, 323 and second side holes 153, 353 are formed on the sides of the first plate body 122, 322 and the second plate body 146, 346, respectively. The first side holes 123, 323 and the second side holes 153, 353 connect the internal space of the spinal fusion cage 100, 300 to the periphery, and when an osteogenic material is charged into the inside of the spinal fusion cage 100, 300, the osteogenic material can be discharged to the outside, thereby connecting the inside and outside of the spinal fusion cage 100, 300.

[0058] The plate sliders 132, 158, 332, 358 disposed in the proximal direction and the plate sliders 142, 168, 342, 368 disposed in the distal direction have different widthwise distances from the axis of the adjustment members 110, 310. That is, the widthwise distance of the plate sliders 132, 158, 332, 358 disposed in the proximal direction from the axis of the adjustment members 110, 310 is longer than the widthwise distance of the plate sliders 142, 168, 342, 368 disposed in the distal direction from the axis of the adjustment members 100, 300.

[0059] This feature is particularly important in cases where the width is long, such as ALIF, because the proximal moving block 106, 306 supporting the adjustment member 110, 310 must have a small width relative to the axis of the adjustment member 110, 310 in order to ensure a large space around the proximal moving block 106, 306. Therefore, as shown in Fig. 3 or Fig. 24, when the height of the spinal fusion cage 100, 300 is increased, it is convenient to insert additional osteogenic material around the proximal moving block 106, 306 into the internal space of the spinal fusion cage 100, 300, and the amount of insertion can be increased.

[0060] On the contrary, as shown in Fig. 2 or 23, the spinal fusion cage 100, 300 must be formed with no gap in the distal direction because it is inserted between the vertebrae bodies with the height at a minimum. Therefore, the width of the distal moving block 108, 308 is formed to be approximately the same as the width of the distal side of the first end plate 102, 302 and the distal side of the second end plate 104, 304.

[0061] At this time, since the proximal moving block 106, 306 has a small width relative to the axis of the adjusting member 110, 310, the block slider 180, 380 has a small width relative to the axis of the adjusting member 110, 310. In order to complement the stability of the structure, the block slider 204, 504 formed on the distal moving block 108, 308 is formed at both ends of the distal moving block 108, 308 so as to increase the width relative to the axis of the adjusting member 110, 310 as much as possible. Therefore, the proximal block slider 180, 380 and the distal block slider 204, 404 may be formed in a trapezoid shape that is generally narrow on the proximal side and long on the distal side.

[0062] As shown in Figures 15 and 16 or 34 and 35, the proximal moving block 106, 306 has a block inclined portion 174, 374 formed on the proximal side centering on a proximal connecting pipe 190, 390 having an adjustment member hole 188, 388 into which the adjustment member 110, 310 is inserted and supported. Block sliders 180, 380 slidably coupled to plate sliders 132, 158, 332, 358 formed on the first and second end plates 102, 104, 302, 304 are disposed on both sides of the block inclined portion 174. The adjustment member holes 188, 388 have support portions 184, 384 that contact and support the adjustment members 110, 310, and support steps 186, 386 formed on the distal end of the support portions 184, 384 to prevent the adjustment members 110, 310 from coming off.

[0063] Also, pin holes 178, 378 are formed on the side of the proximal moving block 106, 306 to prevent the proximal side of the adjustment member 110, 310 located at the support portion 184, 384 from coming off. Also, instrument seats 176, 376 are formed on the side of the proximal moving block 106, 306 so that an instrument can fix the spinal fusion cage 100, 300. Also, bolt fastening portions 182, 382 are formed proximal to the region where the adjustment member 110, 310 is inserted, to which an instrument or another implant such as a plate can be connected.

[0064] As shown in Figures 17 and 18 or 36 and 37, the terminal moving block 108, 308 is formed with a terminal connection tube 198, 398 having a moving block threaded portion 202, 402 at the center, which is threadedly coupled with the adjustment member 110, 310, and has wings 196, 396 on both sides of the terminal connection tube 198, 398. Block inclined portions 194, 394 are formed on the wings 196, 396, and block sliders 204, 404 are disposed on both sides of the wings 196, 396. Block auxiliary sliders 206, 406 are formed on the outer sides of the block sliders 204, 404. The block sliders 204, 404 and the block sub-sliders 206, 406 are slidingly coupled to the plate sliders 142, 168, 342, 368 and plate sub-sliders 144, 170, 344, 370 of the first and second end plates 102, 104, 302, 304, respectively.

[0065] The distal moving block 108, 308 has a distal wall 192, 392 for easy insertion between vertebral bodies, and the distal wall 192, 392 is integral with the block inclined portion 194, 394. When the height is at its lowest, the distal wall 192, 392 contacts the end of the first end plate 102, 302 and the end of the second end plate 104, 304 to form a single insertion portion as a whole. In particular, distal bent surfaces 208, 408 are formed on both sides of the distal wall 192, 392 to further facilitate insertion.

[0066] A reinforcing slope 200, 400 is formed at the center of the distal moving block 108, 308, and serves to strengthen the load supported by the block slider 204, 404 and the block auxiliary slider 206, 406. As described above, the reinforcing slope 200, 400 is inserted into the reinforcing slope seats 140, 166, 340, 366 of the first end plate 102, 302 and the second end plate 104, 304, and is stably positioned.

[0067] The distal moving block 108, 308 and the proximal moving block 106, 306 have a generally wedge-like structure that biases the first endplate 102, 302 and the second endplate 104, 304 up and down.

[0068] The adjustment member 110, 310 may have a substantially bolt-shaped shape as shown in Fig. 19 or 38. That is, the adjustment member 110, 310 has an adjustment member support surface 210, 410 and an adjustment screw portion 214, 314. A connection portion 212, 412 may be formed between the adjustment member support surface 210, 410 and the adjustment screw portion 214, 414. A pin seat 218, 418 is formed on the proximal side of the adjustment member support surface 210, 410, and a tool groove 216, 416 is formed at the center thereof to provide a driving force to the adjustment member 110, 310. The adjustment screw portion 214, 414 is a male screw, but a detailed illustration is omitted in the drawings.

[0069] The adjustment member support surface 210, 410 is in contact with the support portion 184 of the distal moving block 108, 308 and is rotatably supported. The adjustment screw portion 214, 414 is screw-coupled with the moving block screw portion 202, 402 of the adjustment member 110, 310. The moving block screw portion 202, 402 is an internal screw, but detailed illustration is omitted in the drawings. And, since the distal margin surface of the adjustment member support surface 210, 410 contacts the support step 186, 386, the adjustment member 110, 310 does not come off in the distal direction from the distal moving block 108, 308. Also, since the pin member 118, 318 is inserted into the pin seat 218, 418 and positioned in the pin seat 218, 418, the adjustment member 110, 310 does not come off in the proximal direction from the distal moving block 108, 308.

[0070] As a result, the adjustment members 120, 320 can rotate in the correct position within the adjustment members 110, 310.

[0071] As shown in Figures 10 and 11, the vertical guide portion comprises a first vertical guide formed in the thickness direction of the first end plate 102, 302 or the second end plate 122, 322, and a second vertical guide formed in the thickness direction of the first end plate 102, 302 or the second end plate 122, 322 and performing a sliding motion with the first vertical guide.

[0072] Two pairs of vertical guides are arranged, one pair of the vertical guides is arranged on one side of the first end plate 102, 302 and the second end plate 122, 322 in the width direction, and the other pair of the vertical guides is arranged on the other side of the first end plate 102, 302 and the second end plate 122, 322 in the width direction. That is, the following three cases occur. The first is a case where first vertical guides are installed on both sides of the first end plate 102, 302, and second vertical guides are installed on both sides of the second end plate 122, 322. The second is a case where second vertical guides are installed on both sides of the first end plate 102, 302, and first vertical guides are installed on both sides of the second end plate 122, 322. The third case is where a first vertical guide and a second vertical guide are installed on both sides of the first end plates 102 and 302, respectively, and a second vertical guide and a first vertical guide are installed on both sides of the second end plates 122 and 322 so as to correspond to the first end plates 102 and 302. Hereinafter, the first case will be described as an example.

[0073] The first vertical guide is a post 124,324 that protrudes in the thickness direction of the first end plate 102,302, and the second vertical guide has a channel 150,350 that surrounds a portion of the outer surface of the post 124,324.

[0074] The receiving portions 126, 326 are formed around the pillars 124, 324. The receiving portions 126, 326 are spaces for receiving the extensions 148, 348 described below, and first receiving grooves 1261, 3261 are formed on the proximal side, and second receiving grooves 1262, 3262 are formed on the distal side.

[0075] The channel 150, 350 is formed by a first groove portion disposed to be recessed in the width direction of the second end plate 104, 304, and a second groove portion formed by an extension portion 148, 348 protruding in the thickness direction of the second end plate 104, 304 from the first groove portion.

[0076] Here, the extension 148 of the first embodiment has a guide portion 147 formed at an upper end thereof so that the extension 148 can be easily inserted into the receiving portion 126. Also, the extension 348 of the second embodiment has a cut-off portion 349 formed in a proximal direction. The cut-off portion 349 is formed to prevent the bone screw 320 from interfering with the extension 348 when it is inserted.

[0077] As shown in FIG. 14, the first groove portion is formed to be recessed by a first groove wall 1491, 3491 arranged on the proximal side, a second groove wall 1492, 3492 arranged on the distal side spaced apart from the first groove wall 1491, 3491, and a third groove wall 1493, 3493 connecting the first groove wall 1491, 3491 and the second groove wall 1492, 3492.

[0078] The second groove portion is formed by extension portions 148, 348 consisting of a first extension wall 1511, 3511 protruding in the thickness direction of the second end plate 104, 304 and positioned on the proximal side, a second extension wall 1512, 3512 protruding in the thickness direction of the second end plate 104, 304 and positioned on the distal side, and a third extension wall 1513, 3513 protruding in the thickness direction of the second end plate 104, 304 and connecting the first extension wall 1511, 3511 and the second extension wall 1512, 3512.

[0079] Therefore, the first groove portion and the second groove portion form a groove having a substantially U-shape. The first extension wall 1511, 3511 is flat with the first groove wall 1491, 3491, the second extension wall 1512, 3512 is flat with the second groove wall 1492, 3492, and the third extension wall 1513, 3513 is flat with the third groove wall 1493, 3493. As a result, the first groove portion and the second groove portion form channels 150, 350 as a whole, and the pillars 124, 324 can perform a sliding motion with respect to the channels 150, 350.

[0080] The width direction depth of the second groove portion is smaller than the width direction depth of the first groove portion. In this case, the width direction thickness of the pillars 120, 324 is the same as the width direction depth of the first groove portion, and the length direction thickness of the pillars 124, 324 is formed to be the same as the length direction distance between the first groove walls 1491, 3491 and the second groove walls 1492, 3492.

[0081] Therefore, when the pillars 124, 324 are inserted into the channels 150, 350, the first groove portion surrounds two longitudinal faces and one widthwise face of the pillars 124, 324, whereas the second groove portion surrounds one widthwise face of the pillars 124, 324 entirely but only partially surrounds two longitudinal faces.

[0082] In order to support a force applied in the length direction, it is preferable that the sum of the lengthwise thicknesses of the first extension walls 1511, 3511 and the second extension walls 1512, 3512 is equal to or greater than the lengthwise thickness of the pillars. Also, in order to maximize the force applied in the width direction, it is preferable that the widthwise thickness of the third extension walls 1513, 3513 is equal to the widthwise thickness of the pillars 124, 324.

[0083] Guide grooves 152, 352 are formed around the first groove portion to guide the insertion of the pillars 124, 324, so that the pillars 124, 324 are naturally guided toward the first groove portion when the spinal fusion cages 100, 300 are assembled or raised and then lowered.

[0084] Next, other structures of the spinal fusion cage 100 of the first embodiment and the spinal fusion cage 300 of the second embodiment will be described.

[0085] In the spinal fusion cage 100 of the first embodiment, a center groove 155 is formed in the proximal portion of the first end plate 102 or the second end plate 104. In the first embodiment, the center groove 155 is formed only in the second end plate 104.

[0086] The center groove 155 is formed in the first plate body 122 or the second plate body 146 at the proximal portion to prevent the spinal fusion cage 100 from coming off in the opposite direction to the insertion direction after the spinal fusion cage 100 is inserted between the vertebral bodies. As shown in Fig. 6, the bone screw 120 is inserted into the center groove 155 and inserted into the vertebral body. The bone screw 120 includes a threaded portion 240, a screw head 236 formed on one side of the threaded portion 240, and a tool groove 238 formed in the screw head 236 to be coupled with a tool such as a screwdriver.

[0087] 7, a cover plate 112 is installed on the proximal moving block 106 to cover the bone screw 120. The cover plate 112 can also be used without the bone screw 120 installed as shown in FIG. 5. This prevents the proximal moving block 106 and the center groove 155 from being exposed, and in particular, when the cover plate 112 is fixed, the cover bolt 114 is directly fastened to the bolt fastening portion 182 formed on the proximal moving block 106, preventing the adjustment member 110 from loosening. More specifically, when the cover bolt 114 is locked and comes into contact with the adjustment member 110, the cover bolt 114 functions as a lock nut for the adjustment member 110.

[0088] The cover plate 112 and the cover bolts 114 are as shown in FIG.

[0089] The cover plate 112 is formed with a bolt seat 224 to which the cover bolt 114 is attached, and a fixing ring seat 226 to which a fixing ring 116 is attached, which is installed to prevent the cover bolt 114 from coming off the cover plate 112. The cover plate body 220 of the cover plate 112 is formed with a tool seat 228 to grip the cover plate 112 with a tool. In the first embodiment, the tool seat 228 may be formed in the form of a groove recessed on both sides of the cover plate body 220.

[0090] In addition, the cover plate body 220 has an extension 222 that can cover the center groove 155 and extends toward the first end plate 102 or the second end plate 104 .

[0091] The cover bolt 114 has a cover bolt threaded portion 234 that is threadedly coupled to the bolt fastening portion 182 of the proximal moving block 106, and a cover bolt head 230 formed at a position facing the cover bolt 234. A fixing ring support portion 235 is formed between the cover bolt head 230 and the cover bolt threaded portion 234 so as to be recessed.

[0092] As shown in Figures 29 to 32, the spinal fusion cage 300 of embodiment 2 has bone screw holes 334, 360 formed in the first end plate 302 and the second end plate 304, respectively, and bone screws 320 are inserted through the bone screw holes 334, 360 and installed in the vertebral bodies.

[0093] The bone screw holes 334, 360 are formed to be inclined in the length direction and may also be formed to be inclined in the width direction. Guide surfaces 336, 362 are formed around the bone screw holes 334, 360 to guide the bone screw 320 toward the bone screw holes 334, 360. The bone screw 320 includes a threaded portion 440 having a screw thread formed thereon, a screw head 436 formed on one side of the threaded portion 440, and a tool groove 438 formed in the screw head 436 to be coupled with a tool such as a driver.

[0094] In order to prevent the bone screw 320 from coming off, the spinal fusion cage 100 of the second embodiment additionally includes a locking member.

[0095] The locking member may include a locking plate 312 that covers the bone screw 320 and a locking bolt 314 that passes through the locking plate 312 and is fixed to the proximal movement block 306, as shown in Figures 27 and 28.

[0096] 39 and 40, the lock plate 312 has a generally plate-shaped lock plate body 420, and cover parts 422 extending to both sides of the lock plate body 420 may be formed to be slightly curved in order to cover the lock bolt 414. The lock plate body 420 is formed with an instrument seat 428, and in the second embodiment, the instrument seat 428 is a hole penetrating both sides of the cover part 422.

[0097] In addition, a lock bolt seat 424 is formed in the center of the lock plate body 420 to receive the lock bolt 114. A fixing ring seat 426 to receive the fixing ring 316 is disposed around the lock bolt seat 422.

[0098] The lock bolt 114 may be screwed to a bolt fastening portion 382 to which the lock bolt 314 can be coupled, at a front end of the adjustment member 310 of the proximal moving block 306. When the lock bolt 314 is fastened to the proximal moving block 306 and comes into contact with the adjustment member 310, the lock bolt 314 presses the adjustment member 310 and simultaneously generates frictional force at the contact area. As a result, the adjustment member 310 has an advantage that the frictional force increases at the threaded area, and the adjustment member 310 does not loosen even when a load, especially a repeated load, is applied to the first end plate 302 and the second end plate 304.

[0099] The lock bolt 314 includes a lock bolt head 430 that can be attached to the lock bolt seat 424, a lock screw portion 434 having a thread that is fastened to the bolt fastening portion 382, ​​and a tool groove 432 to which a tool is coupled. In particular, a ring groove can be disposed in the lock bolt 314, and a fixing ring 316 can be inserted into the ring groove so that the lock bolt 314 does not come off from the lock plate 312.

[0100] The spinal fusion cages 100 and 300 are constructed as described above, and the method of operating the spinal fusion cage 100 will be described below.

[0101] First, a surgical path to the vertebrae is secured using surgical instruments, and the target disk is removed. Then, the spinal fusion cage 100, 300 is inserted between the vertebrae from which the disk has been removed while holding the spinal fusion cage 100 with a cage holder (not shown).

[0102] Thereafter, an instrument such as a screwdriver is inserted into the tool grooves 216, 416 of the adjustment members 110, 310 and rotated in one direction to bring the proximal moving blocks 106, 306 and the distal moving blocks 108, 308 closer to each other, thereby moving the first end plates 102, 302 and the second end plates 104, 304 away from each other.

[0103] In the case of the first embodiment, the bone screw 120 is set in the center groove 155. In the case of the second embodiment, the bone screw 320 is set through the bone screw holes 334 and 360.

[0104] Thereafter, in the case of the first embodiment, the cover plate 112 is attached to the proximal movement block 106 by the cover bolt 114. In the case of the second embodiment, the lock plate 312 is attached to the proximal movement block 306 by the lock bolt 314.

[0105] In the event that the spinal fusion cage 100, 300 is inserted incorrectly or is to be removed for reoperation, the spinal fusion cage 100, 300 is removed by following the above-described surgical procedure in reverse order.

[0106] That is, the cover bolt 114 or the lock bolt 314 is loosened to separate the cover plate 112 or the lock plate 312 from the proximal moving block 106, 306. Then, while holding the spinal fusion cage 100, 300 with a cage holder (not shown), an instrument such as a screwdriver is inserted into the adjustment member 110, 310 and rotated in the other direction to increase the distance between the proximal moving block 106, 306 and the distal moving block 108, thereby decreasing the distance between the first end plate 102, 302 and the second end plate 104, 304 and decreasing the overall height, thereby allowing the cage to be detached from the vertebral body.

[0107] As described above, the present invention has been described with reference to a preferred embodiment. However, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention as set forth in the following claims. Possible industrial applications

[0108] The present invention has the advantages that one cage can accommodate a certain range of heights, thereby reducing inventory and production burdens, and that repetitive tasks during surgery can be reduced, reducing the burden on doctors, and that surgery time can be reduced, reducing blood loss and significantly shortening patient recovery time, and therefore can be widely used in the relevant fields. [Explanation of symbols]

[0109] 100: Spinal fusion cage 102: First end plate 104: 2nd end plate 106: Proximal mobile block 108: Terminal moving block 110: Adjustment member 112: Cover plate 114: Cover bolt 116: Fixing ring 118: Pin component 120: Bone screw 122: First plate body 123: First side hall 124: Pillar 126: Storage unit 128, 139, 154, 165: Plate inclination 130, 156: Seat of proximal mobile block 132, 142, 158, 168: Plate slider 133, 157: Plate auxiliary support part 138, 164: Terminal moving block seats 140, 166: Reinforced inclined seat 144, 170: Plate auxiliary slider 145: First window 146: 2nd plate body 147: Information Department 148: Extension 150:Channel 152: Guide groove 153: 2nd side hall 155: Center groove 172: Second window 174, 194: Block inclination section 176: Instrument seat 178: Pinhole 180, 204: Block slider 181: Block auxiliary support part 182: Bolt fastening part 184: Support part 186: Support stage 188: Adjustment component hole 190: Proximal connecting tube 192: End wall 196: Wings 198: Terminal connection tube 200: Reinforced inclined section 202: Moving block screw part 206: Block auxiliary slider 208: Terminal curved surface 210: Adjustment screw fixing part 212: Adjustment screw support 214: Adjustment screw part 216: Tool groove 218:Pin's seat 220: Cover plate body 222: Extension part 224: Bolt's seat 226: Fixed ring seat 228: Instrument seat 230: Cover bolt head 232: Tool groove 234: Cover bolt thread 235: Fixed ring support 236: Bone screw head 238: Tool groove 240: Bone screw thread 1261: First storage ditch 1262: Second storage groove 1491: First ditch wall 1492: Second ditch wall 1493: 3rd Ditch Wall 1511:1st extension wall 1512:Second extension wall 1513: Third extension wall 300: Spinal fusion cage 302: 1st end plate 304: 2nd end plate 306: Proximal transfer block 308: Terminal moving block 310: Adjustment member 312: Lock plate 314: Rock bolt 316: Fixing ring 318: Pin parts 320: Bone screw 322: First plate body 323: First side hall 324: Pillar 326: Storage unit 328, 339, 354, 365: Plate inclination 330, 356: Seat of proximal mobile block 332, 342, 358, 368: Plate sliders 333, 357: Plate auxiliary support 334, 360: Bone screw holes 336, 362: Guide surface 338, 364: Terminal moving block seats 340, 366: Reinforced inclined seat 344, 370: Plate auxiliary slider 345: First window 346: 2nd plate body 348: Extension 349: Cut-off section 350:Channel 352: Guide groove 353: 2nd side hall 372: Second window 374, 394: Block inclination section 376: Instrument seat 378: Pinhole 380, 404: Block slider 381: Block auxiliary support part 382: Bolt fastening part 384: Support part 386: Support stage 388: Adjustment component hole 390: Proximal connecting tube 392: End wall 398: Terminal connection tube 400: Reinforced slope 402: Moving block screw part 406: Block auxiliary slider 408: Terminal curved surface 410: Adjustment screw fixing part 412: Adjustment screw support 414: Adjustment screw part 416: Tool groove 418:Pin's seat 420: Cover plate body 422: Wing part 424: Bolt's seat 426: Fixed ring seat 428: Instrument seat 430: Cover bolt head 432: Tool groove 434: Cover bolt thread 435: Fixed ring support 3261: First storage ditch 3262: Second storage ditch 3491: First trench wall 3492: Second groove wall 3493: 3rd ditch wall 3511: 1st extension wall 3512:Second extension wall 3513: Third extension wall

Claims

1. 1. A spinal fusion cage for anterior vertebral fusion, comprising: a first endplate and a second endplate contacting adjacent vertebral bodies; and a terminal moving block connected to terminal portions of the first end plate and the second end plate so as to be movable relative to each other; a proximal movement block coupled to proximal portions of the first end plate and the second end plate so as to be movable relative to each other; an adjustment member capable of adjusting the distance between the proximal moving block and the distal moving block by rotating to adjust the distance between the distal moving block and the proximal moving block; a vertical guide portion disposed on the first end plate and the second end plate and configured to support a load in a length direction or a width direction of the first end plate and the second end plate, The distal moving block and the proximal moving block are formed with block sliders; The first and second end plates are provided with plate sliders that slide relative to the block sliders, a distance in a width direction of the block slider of the distal moving block from the axis of the adjustment member is longer than a distance in a width direction of the block slider of the proximal moving block from the axis of the adjustment member; A center groove is disposed in the proximal end of the first or second end plate. A spinal fusion cage comprising:

2. 2. The spinal fusion cage according to claim 1, wherein a block auxiliary slider is disposed around the distal moving block, and the first and second end plates are formed with plate auxiliary sliders that slide on the block auxiliary slider.

3. The spinal fusion cage according to claim 2 , wherein the block auxiliary slider is disposed at an end in a width direction of the distal moving block.

4. The spinal fusion cage according to claim 2 , wherein the block auxiliary slider is disposed in a direction opposite to the block slider.

5. 2. The spinal fusion cage of claim 1, wherein the adjustment member has a threaded portion at one end that threadably couples with the distal moving block and a rotation support seat at the other end that is rotatably fixed to the proximal moving block, and the rotation support member is positioned at the rotation support seat through the proximal moving block.

6. the vertical guide portion includes a first vertical guide formed in a thickness direction of the first end plate or the second end plate, and a second vertical guide formed in a thickness direction of the first end plate or the second end plate and sliding with the first vertical guide, The vertical guide portion is arranged in two pairs, one pair of the vertical guide portions is disposed on one side of the first end plate and the second end plate in a width direction, The other pair of vertical guide portions is disposed on the other side of the first end plate and the second end plate in the width direction.

10. The spinal fusion cage of claim 1.

7. 7. The spinal fusion cage of claim 6, wherein the first vertical guide is a post protruding in a thickness direction of the first or second end plate, and the second vertical guide has a channel surrounding a portion of an outer surface of the post.

8. The channel is formed by a first groove portion disposed so as to be recessed in the width direction of the first or second end plate, and a second groove portion formed by an extension portion protruding from the first or second end plate in the thickness direction of the first or second end plate.

8. The spinal fusion cage of claim 7.

9. A receiving portion is formed around the pillar to receive the extension portion.

9. The spinal fusion cage of claim 8.

10. The first groove portion is formed to be recessed by a first groove wall disposed on a proximal side, a second groove wall disposed on a distal side apart from the first groove wall, and a third groove wall connecting the first groove wall and the second groove wall.

9. The spinal fusion cage of claim 8.

11. The width direction thickness of the pillar is the same as the width direction depth of the first groove portion, and the length direction thickness of the pillar is the same as the length direction distance between the first groove wall and the second groove wall.

11. The spinal fusion cage of claim 10.

12. The second groove portion is formed by an extension portion including a first extension wall that protrudes in a thickness direction of the first or second end plate and is disposed on a proximal side, a second extension wall that protrudes in the thickness direction of the first or second end plate and is disposed on a distal side, and a third extension wall that protrudes in the thickness direction of the first or second end plate and connects the first extension wall and the second extension wall, the first extension wall being planar with the first groove wall, the second extension wall being planar with the second groove wall, and the third extension wall being planar with the third groove wall.

11. The spinal fusion cage of claim 10.

13. The width direction depth of the second groove portion is smaller than the width direction depth of the first groove portion.

13. The spinal fusion cage of claim 12.

14. A guide groove for guiding the insertion of the pillar is formed around the first groove portion.

9. The spinal fusion cage of claim 8.

15. The sum of the longitudinal thicknesses of the first extension wall and the second extension wall is equal to or greater than the longitudinal thickness of the column.

13. The spinal fusion cage of claim 12.

16. The width direction thickness of the third extension wall is the same as the width direction thickness of the column.

13. The spinal fusion cage of claim 12.

17. Through holes are disposed on the sides of the first and second end plates.

10. The spinal fusion cage of claim 1.

18. A cover member is provided on the proximal moving block.

10. The spinal fusion cage of claim 1.

19. The cover member includes a cover plate that covers the center groove, and a cover bolt that penetrates the cover plate and is fixed to the proximal moving block.

20. The spinal fusion cage of claim 18.

20. The cover plate is provided with an extension that covers the center groove.

20. The spinal fusion cage of claim 19.

21. A spinal fusion cage for anterior vertebral fusion, comprising: a first endplate and a second endplate contacting adjacent vertebral bodies; and a terminal moving block connected to terminal portions of the first end plate and the second end plate so as to be movable relative to each other; a proximal movement block coupled to proximal portions of the first end plate and the second end plate so as to be movable relative to each other; an adjustment member capable of adjusting the distance between the proximal moving block and the distal moving block by rotating to adjust the distance between the distal moving block and the proximal moving block; a vertical guide portion disposed on the first end plate and the second end plate and configured to support a load in a length direction or a width direction of the first end plate and the second end plate, The distal moving block and the proximal moving block are formed with block sliders; The first and second end plates are provided with plate sliders that slide relative to the block sliders, a distance in a width direction of the block slider of the distal moving block from the axis of the adjustment member is longer than a distance in a width direction of the block slider of the proximal moving block from the axis of the adjustment member; bone screws inserted through bone screw holes formed in the first end plate and the second end plate; and a locking member fastened to the proximal translation block to prevent backout of the bone screw; the locking member includes a locking plate that covers the bone screw, and a locking bolt that passes through the locking plate and is fixed to the proximal moving block, and the proximal moving block is provided with a locking bolt fastening portion to which the locking bolt can be coupled at a front end of the adjustment member; A spinal fusion cage, wherein the lock plate is formed with a seat for an instrument penetrating the lock plate in the anterior-posterior direction.

22. The lock bolt contacts and biases the adjustment member when connected.

22. The spinal fusion cage of claim 21.

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