Lumbar interbody fusion stent and preparation method and application thereof

Abstract

The invention discloses a lumbar interbody fusion stent, which is used for lumbar interbody bone grafting fusion, and comprises a fusion stent main body and a cushion block with an anatomical adaptive footprint surface, the fusion stent main body is X-shaped on the whole; the cushion block comprises an upper cushion block and a lower cushion block; the upper cushion block and the lower cushion block are detachably mounted on the fusion stent main body. The fusion stent main body is made of a nickel-titanium alloy material; and the cushion block is made of a PEEK material. The invention further discloses a preparation method of the lumbar interbody fusion stent and a bone grafting fusion method applying the lumbar interbody fusion stent. The invention further discloses application of the lumbar interbody fusion stent to bone grafting fusion.

Description

Technical Field

[0001] The present invention belongs to the field of medical devices and relates to a lumbar intervertebral fusion bracket, a bracket preparation method and an application. Background Art

[0002] Lumbar interbody fusion is the most important surgical procedure for restoring lumbar stability and lumbar force alignment. The number of operations has increased year by year in recent years. Regardless of whether the surgical approach is retroperitoneal or anterior intraperitoneal interbody fusion (ALIF), posterior interbody fusion (PLIF), transforaminal interbody fusion (TLIF), lateral transpsoas interbody fusion (XLIF / LLIF / DLIF), or lateral anterior oblique interbody fusion (OLIF), the core technology is to implant an interbody fusion cage and bone / bone substitute materials into the processed target intervertebral space. The fusion cage mainly plays a role in maintaining the height, lordosis and immediate stability of the target intervertebral space to varying degrees through its structural design and material design, while the bone / bone substitute material can induce bony fusion in the target intervertebral space, thereby obtaining long-term stability of the target intervertebral space.

[0003] The most commonly used lumbar intervertebral fusion device in clinical practice at home and abroad is a box-like fusion device. The basic operation method is: pre-fill the bone / bone substitute material in the bone graft groove of the fusion device during the operation, then install the fusion device to the head end of the holder, and implant the fusion device into the target intervertebral space by hitting the tail end of the holder. If necessary, use a punch and a hammer to adjust the direction and position of the fusion device in the intervertebral space by hitting. When the height of the fusion device is greater than the height of the target intervertebral space, the fusion device cannot be implanted. Forced implantation will cause damage to the vertebral endplate, the fusion device will sink into the vertebral body, or cause the fusion device to break. There are even cases where the fusion device / bone graft particles are hit forward to break through the anterior annulus fibrosus and enter the peritoneum due to excessive hitting force; when the height of the fusion device is smaller than the target intervertebral space, although the implantation process is easier, the footprint of the fusion device cannot be in close contact with the vertebral endplate, increasing the risk of the fusion device retreating into the spinal canal or the target intervertebral space not being fused.

[0004] Some manufacturers and surgeons have designed, produced and used a height-adjustable intervertebral fusion device. The height-adjustable intervertebral fusion device is characterized by a small height before entering the intervertebral space, and the height of the device is increased by a mechanical component (rotatable and propulsive support block) after entering the intervertebral space. Although this design achieves the two goals of easy implantation of the device and consistency with the intervertebral space height, it still has shortcomings. On the one hand, since the knob for adjusting the height of the device is located at the rear of the device, the device can only be placed in the front-to-back longitudinal direction, and the mechanical stability in this direction is lower than that of oblique or transverse placement. On the other hand, unlike the hollow box-shaped device (whose bone grafting groove can be filled with bone / bone substitute material), the internal bone grafting of the height-adjustable device will be affected: if bone is pre-grafted in vitro, either the implanted bone / bone substitute material will affect the height adjustment of the device, or the pre-implanted bone / bone substitute material will not be in close contact with the vertebral endplate as the fusion height increases; after this type of device enters the intervertebral space and adjusts its height without pre-grafting bone, the internal bone grafting will also be limited due to the space-occupying effect of its mechanical components. The above-mentioned shortcomings of bone grafting are bound to affect the amount of bone grafting in the target intervertebral space and the final fusion results.

[0005] In addition, due to individual differences in the anatomical morphology of the lumbar vertebral endplates, the above-mentioned box-like fusion devices and height-adjustable intervertebral fusion devices cannot perfectly match the target intervertebral space of most patients in terms of anatomical morphology. As a result, the contact area between the fusion device footprint and the vertebral endplate is small (point contact rather than surface contact), resulting in axial displacement, i.e., fusion device sedimentation (especially when the patient has coexisting osteoporosis), causing intervertebral nonfusion or re-inducing neurological symptoms; and when the sagittal contour of the fusion device is not compatible with the lordosis of the target intervertebral space, it cannot effectively restore and maintain the lordosis of the target intervertebral space, which may cause compensatory malalignment of the adjacent intervertebral disc and accelerate its degeneration, inducing adjacent vertebral disease.

[0006] In order to make the fusion device more compatible with the anatomical morphology of the intervertebral space, some researchers have used 3D printing technology to make personalized intervertebral fusion devices. Although 3D printing technology can well solve the problem of shape adaptation between the fusion device footprint and the vertebral endplate, because the final expansion height of the target intervertebral space during the operation cannot be predicted before the operation, the height of the 3D printed fusion device and the target intervertebral space may be inconsistent, making the 3D printed fusion device unusable. Printing multiple fusion devices of different heights for one target intervertebral space will obviously cause waste. Summary of the invention

[0007] In order to solve the deficiencies in the prior art, the main purpose of the present invention is to provide a lumbar intervertebral fusion stent and a stent preparation method.

[0008] The present invention provides a lumbar intervertebral fusion stent, the lumbar intervertebral fusion stent comprising a fusion stent body and a cushion block;

[0009] The fusion stent body is X-shaped as a whole;

[0010] The pad includes an upper pad and a lower pad; the upper pad and the lower pad are detachably mounted on the fusion support body; in addition, other supporting structures such as support pads and support bars can be selected to replace the pads according to actual conditions, and can be detachably mounted on the fusion support body; the pad includes an anatomical adapter and a connecting portion, the length a of the anatomical adapter is 10-12 mm, the width b is 6-10 mm, and the minimum thickness is 2 mm; the pad is obtained by personalized 3D printing and / or machining prefabrication, and the specific size is determined according to the actual measurement data of different people;

[0011] The upper pad is used to abut against the lower end plate of the upper vertebral body; the lower pad is used to abut against the upper end plate of the lower vertebral body.

[0012] The fusion stent body is an integrated structure, including two long plates with waist-shaped holes, namely a first long plate and a second long plate, wherein the first long plate and the second long plate are crossed to form an X shape; in a specific usage scenario, the lengths of the first long plate and the second long plate are generally equal;

[0013] The length l of the fusion stent body is 20-40 mm, preferably 26-36 mm, the width of the fusion stent body is substantially consistent with the length a of the cushion block, which is about 10-12 mm, and the height h of the fusion stent body is 6-14 mm; the height of the lumbar intervertebral fusion stent includes the height of the fusion stent body and the thickness of the upper and lower cushion blocks, which is 10-18 mm;

[0014] In a specific embodiment, the length l of the fusion stent body is 26 mm, the width of the fusion stent body is 10 mm, and the height h of the fusion stent body can be selected from one or more of 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, etc.;

[0015] The two ends of the first long board and the second long board are also bent and extended, and are provided with horizontal support parts, namely, an upper support part and a lower support part, which are provided at the ends of the long boards; the thickness of the support parts is uniform, and the upper support part and the lower support part are parallel; the size of the support parts is basically consistent with the size of the pad, that is, the length of the support parts is 10-12mm and the width is 6-10mm. The support parts can be connected to the two ends of the long board in an integrated manner. When the support parts are connected to the two ends of the long board in an integrated manner, additional connecting parts are omitted, making the structure more stable and lighter overall.

[0016] The intersection of the two long plates is thicker and the ends are thinner; the thickness of the supporting portion is uniform.

[0017] Further, the upper pad block is detachably mounted on the upper support portion, and the lower pad block is detachably mounted on the lower support portion.

[0018] The length-to-width ratio of the first long board and the second long board is (3-10):1. Preferably, the length-to-width ratio is (5-8):1.

[0019] The upper support part and the lower support part are respectively provided with one or more slots, and the slots are also provided with slot threads. The shape of the slot can be circular or other shapes, such as regular hexagonal, waist-shaped, etc. When the slot is waist-shaped, the clamping part can be an umbrella-shaped cap, and when the slot is circular, the clamping part can be a semi-umbrella-shaped cap. Different slot shapes use different clamping part shapes to facilitate the installation of the pad.

[0020] The cushion block comprises an anatomical adapting portion and a connecting portion, wherein the shape, size and quantity of the connecting portion match the shape, size and quantity of the slot, and the cushion block is fixedly connected to the upper supporting portion or the lower supporting portion through the connecting portion;

[0021] The thinnest part of the anatomical adaptor is 2 mm, and the surface in contact with the vertebral end plate is called the footprint surface, and the surface of the footprint surface is evenly provided with anti-slip patterns of thorn-like and / or stripe-like structures; the depth c (the distance from the highest point to the lowest point) of the thorn-like and / or stripe-like structures on the anti-slip patterns is 0.2-1 mm, and the distance d between two adjacent thorn-like and / or stripe-like structures is 0.5-1.5 mm;

[0022] The connecting part is fixedly connected to the anatomical adapting part, and the connecting part further comprises a connecting body and a clamping part. The anatomical adapting part, the connecting body and the clamping part are integrally arranged and obtained by 3D printing and / or machining. A connecting thread is also arranged between the connecting body and the clamping part.

[0023] The number of the connectors matches the number of the slots, the size of the connector matches the size of the slots; and the connecting threads match the threads of the slots.

[0024] The cushion block in the present invention can be obtained by prefabricating different common models according to the anatomical morphology type / subtype of the Chinese lumbar end plate, or it can be obtained by personalized optimization design based on the patient's medical imaging data (CT) through 3D printing.

[0025] When the fusion stent body is in the martensitic phase under an ice water environment (at a temperature of about 0° C.), it can be deformed in the up and down directions by clamping with a special clamp / tool ​​to reduce the height, while there is no obvious change in the left and right directions.

[0026] The fusion stent body is a shape memory stent made of nickel-titanium alloy; the footprint surface is made of PEEK. In addition to the above materials, the fusion stent body can also be made of other materials with shape memory function and biocompatibility, which can be selected according to actual needs.

[0027] The nickel-titanium alloy material is a shape memory alloy, and the deformation degree of the fusion stent body is related to the temperature. Specifically, when the temperature is low, the fusion stent body can be clamped by a clamp to reduce the height in the up and down directions, which is conducive to entering the intervertebral space; when returning to normal temperature or under body temperature environment, the fusion stent body can automatically return to its original shape and size.

[0028] In an optional embodiment, when the fusion stent body is in the Martensitic phase when placed in ice water, it can be clamped by a clamp to lower its height in the up and down directions, and when it returns to normal temperature or body temperature, the fusion stent body can automatically return to its original shape and size.

[0029] The present invention also provides a method for preparing the above-mentioned lumbar intervertebral fusion stent, the preparation method comprising the following steps:

[0030] S01. Using nickel-titanium memory alloy to prepare standard parts of X-shaped fusion stent bodies of different sizes that can fit the intervertebral space;

[0031] S02. Prefabricate the pads that match the different types / subtypes of anatomical morphology of the Chinese lumbar endplates by machining, or make the pads that match the anatomical shape of the lumbar endplates of a specific individual by 3D printing;

[0032] S03, assembling the cushion block and the X-shaped fusion stent body into a lumbar intervertebral fusion stent.

[0033] In step S01, the preparation method of the standard parts of the fusion stent body is that the sheet material is prepared into standard parts through the process steps of wire cutting, CNC milling, grinding, thermoforming, first heat treatment (350°C), first polishing (smoothness 3.2), second heat treatment, second polishing (smoothness 0.8), decontamination and cleaning, inspection, laser marking, cleaning, drying (60°C), inspection, and packaging.

[0034] In step S02, the design and preparation of a pad adapted to the anatomical shape of a specific individual lumbar endplate by 3D printing includes the following steps:

[0035] Step S021, reconstructing the patient's vertebral CT image data in three dimensions to obtain a three-dimensional vertebral model; wherein the layer thickness during CT image scanning is ≤1 mm;

[0036] Step S022, importing the model file of the prefabricated lumbar intervertebral fusion stent into the three-dimensional vertebral model in step S021 and placing it at the position to be surgically implanted;

[0037] Step S023, extracting upper and lower vertebral body surfaces that are in direct contact with the pad of the lumbar intervertebral fusion bracket, and regenerating a pad model file by using the upper and lower vertebral body surfaces as the upper surface of the pad;

[0038] Step S024: obtaining a personalized designed cushion block through 3D printing according to the regenerated cushion block model file.

[0039] In step S02, the process of prefabricating the pads adapted to the different types / subtypes of anatomical morphologies of the Chinese lumbar endplates by machining is as follows:

[0040] A five-axis linkage turning and milling compound machine is used for all-round high-precision cutting and manufacturing. During the entire processing process, the gasket is only clamped once, thus ensuring the high-precision matching performance between the gasket and the fusion bracket body. When the gasket and the fusion bracket body are installed together, they can be fully matched and always kept in a pre-tightened state after installation, thus ensuring that the gasket does not loosen. The snap-fit ​​design on the gasket utilizes a reverse hook anti-retraction function, and the sliding front section design facilitates the installation of the gasket into the slot of the fusion bracket body. The advantages of the two designs are that there is no back-out phenomenon after installation.

[0041] The present invention also provides a bone grafting and fusion method using the above-mentioned lumbar intervertebral fusion stent, the method comprising:

[0042] S1. In an ice water environment, when the main body of the lumbar intervertebral fusion stent is in the Martensitic phase, it can be clamped by a clamp to lower the height in the vertical direction. After installing four pads to complete the overall assembly, enter the target intervertebral space through an annulus fiber incision on the target intervertebral space, where the upper and lower cartilage end plates, the inner annulus fiber and the nucleus pulposus tissue have been completely removed;

[0043] S2. Under body temperature, the main body of the lumbar intervertebral fusion stent automatically returns to its original size and shape, and the footprint surface of the upper pad and the footprint surface of the lower pad respectively contact with the lower end plate of the upper vertebral body and the upper end plate of the lower vertebral body in the target intervertebral space to form anatomically adapted contact;

[0044] S3. Compression bone grafting with autologous bone particles obtained by decompression in and around the lumbar intervertebral fusion cage is the main bone grafting and fusion method. For the target intervertebral space of osteoporotic patients, an auxiliary bone grafting and fusion method of pouring a mixture of injectable calcium phosphate / calcium sulfate bone cement and autologous local decompression bone particles can also be adopted to increase the force-bearing area of ​​the vertebral endplate and reduce the risk of cage settlement.

[0045] In an optional embodiment, in step S1, a larger fusion stent may be placed obliquely or laterally in the target intervertebral disc space, or two smaller fusion stents may be placed in parallel in the front-to-back direction.

[0046] In an optional embodiment, the composition ratio of the injectable calcium phosphate / calcium sulfate bone cement and the autologous local decompression bone particles is adjusted according to the patient's lumbar spine bone density to match the elastic modulus of the lumbar vertebrae.

[0047] In an optional embodiment, in step S3, a long-acting antibiotic may be added to the solid-liquid mixture of the injectable calcium phosphate / calcium sulfate bone cement and the autologous local decompression bone particles to prevent possible intervertebral disc infection after lumbar interbody fusion surgery.

[0048] The present invention also provides application of the lumbar intervertebral fusion bracket in bone grafting and fusion.

[0049] The beneficial effects of the present invention include:

[0050] 1) The assembly design of the bracket, the upper pad and the lower pad are detachably arranged on the upper side and the lower side of the fusion bracket body, respectively, the footprint surface on the pad is in contact with the upper end plate and the lower end plate surface of the vertebral body, and the anatomical adaptability of the pad footprint surface can be achieved by prefabrication through machining to make it adapt to the different types / subtypes of anatomical morphology of the lumbar end plates of Chinese people, or by 3D printing to make it adapt to the anatomical shape of the lumbar end plates of a specific individual. With the help of anatomical adaptability, its settlement and displacement in the intervertebral space can be effectively reduced; in addition, the assembly design of the bracket can make up for the surgeon's preoperative measurement error of the target intervertebral space height, and avoid the waste caused by printing multiple prostheses of different heights for one intervertebral space.

[0051] Furthermore, the pad is made of PEEK (polyetheretherketone), which has good toughness and can avoid rigid connection with the upper and lower lumbar vertebrae, reducing the burden on the lumbar vertebrae. In addition, its elastic modulus is close to that of the vertebral bone and is adapted to the shape of the vertebral endplate, making it less likely to sink.

[0052] 2) The main body of the fusion stent is in an X-shape, which has a stronger deformation ability and is more suitable for minimally invasive surgery. It is combined with a detachable pad to provide a sufficiently large area of ​​intervertebral support. The greater the intervertebral support provided, the greater the mechanical stability between the stent and the end plate, and the lower the risk of the fusion stent retreating into the spinal canal.

[0053] In addition, bone grafting can be performed inside and around the ample frame contour of the X-shaped fusion cage body, thereby hopefully reducing the incidence of nonfusion of the target intervertebral disc space.

[0054] 3) The main body of the fusion stent is made of shape memory material, preferably nickel-titanium shape memory alloy. It can be clamped in ice water to produce a certain degree of height reduction, and can automatically restore its original shape at room temperature or body temperature. With the help of the deformability of this lumbar intervertebral stent, the main frame of the selected stent that is consistent with the target intervertebral disc height can be reduced in height and width to a certain extent in the Martensitic phase, thereby facilitating the passage through the narrow fiber ring gap in the cross section and the relatively small intervertebral disc edge in the head and tail direction of the human body, avoiding entering the intervertebral disc by striking like conventional fusion devices, thereby reducing the risk of nerve and blood vessel damage and vertebral endplate damage, and can improve the convenience of implanting prostheses into the intervertebral disc during lumbar intervertebral fusion surgery, especially more suitable for minimally invasive lumbar intervertebral fusion surgery under spinal endoscopy. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0056] Figure 1 It is a schematic structural diagram of the lumbar intervertebral fusion stent of the present invention.

[0057] Figure 2 It is a front view structural schematic diagram of the lumbar intervertebral fusion stent of the present invention.

[0058] Figure 3 It is a structural schematic diagram of a cushion block on a lumbar intervertebral fusion support of the present invention.

[0059] Figure 4 It is a left-side structural schematic diagram of the lumbar intervertebral fusion stent of the present invention.

[0060] Figure 5 It is a schematic diagram of the top view of the lumbar intervertebral fusion stent of the present invention.

[0061] Figure 6 It is a partial size schematic diagram of the lumbar intervertebral fusion stent of the present invention.

[0062] Figure 7 It is a partial size schematic diagram of the lumbar intervertebral fusion stent of the present invention.

[0063] Numbers in the figure: 1-fusion stent body, 2-pad, 11-first long plate, 12-second long plate, 13-upper support part, 14-lower support part, 15-waist-shaped hole, 16-slot, 21-anatomical adapter part, 211-anti-slip groove, 22-connecting part, 221-connector, 222-clamping part, 223-connecting thread. DETAILED DESCRIPTION

[0064] The invention is further described in detail with reference to the following specific embodiments and drawings. The process, conditions, experimental methods, etc. for implementing the present invention, except for the contents specifically mentioned below, are all common knowledge and common common sense in the art and are not particularly limited by the present invention.

[0065] The present invention provides a lumbar intervertebral fusion bracket, which is an assembled shape memory anatomically adapted lumbar intervertebral bracket, which can be used for lumbar intervertebral fusion. The fusion bracket includes a fusion bracket body 1, a pad 2 (including an upper pad and a lower pad), and the upper pad and the lower pad are detachably connected to the upper side and the lower side of the fusion bracket body 1, respectively. The fusion bracket body 1 is made of nickel-titanium memory alloy, and a certain degree of height reduction is produced by clamping in ice water, and the original shape can be automatically restored at room temperature or body temperature. With the help of the deformability of this bracket, the convenience of implanting a prosthesis into the intervertebral space during lumbar intervertebral fusion can be improved, especially more suitable for minimally invasive lumbar intervertebral fusion under spinal endoscopy; secondly, with the help of the anatomical adaptability of this bracket, its settlement and displacement in the intervertebral space can be effectively reduced; in addition, the assembled design of this bracket can make up for the operator's preoperative measurement error of the target intervertebral space height, and avoid the waste caused by printing multiple prostheses of different heights for one intervertebral space.

[0066] Example 1

[0067] This embodiment provides a lumbar intervertebral fusion stent, which includes a fusion stent body 1 and a cushion block 2. Figure 1 As shown;

[0068] The fusion stent body 1 is X-shaped as a whole;

[0069] The cushion block 2 includes an upper cushion block and a lower cushion block; the upper cushion block and the lower cushion block are detachably mounted on the fusion stent body 1; Figure 3 As shown, the spacer 2 includes an anatomical adapting portion 21 and a connecting portion 22. Figure 6 , 7 As shown, the length a of the anatomical adapting portion 2 is 10 mm, the width b of the anatomical adapting portion 2 is 8 mm, and the minimum thickness of the anatomical adapting portion 2 is 2 mm;

[0070] The surface where the spacer contacts the vertebral endplate is the footprint surface;

[0071] The footprint surface of the upper pad is used to abut against the lower end plate of the upper vertebral body; the footprint surface of the lower pad is used to abut against the upper end plate of the lower vertebral body.

[0072] like Figure 2As shown, the fusion stent body 1 is an integrated structure, including two pieces with waist-shaped holes 15 (such as Figure 4 , 5 The long plates as shown in the figure are respectively a first long plate 11 and a second long plate 12, the lengths of the two long plates are the same, and the first long plate 11 and the second long plate 12 cross to form an X shape; the setting of the waist-shaped hole 15 can make the structure of the fusion stent body 1 have a certain elastic deformation ability.

[0073] The two ends of the first long board 11 and the second long board 12 are also bent and extended, and are provided with horizontal support parts, namely, an upper support part 13 and a lower support part 14, which are provided at the ends of the long boards. The support parts are integrally connected to the two ends of the long boards. When the support parts are integrally connected to the two ends of the long boards, additional connecting parts are omitted, making the structure more stable and lighter overall.

[0074] The intersection of the two long plates is thicker and the ends are thinner; the thickness of the supporting portion is uniform.

[0075] The upper pad is detachably mounted on the upper support portion 13 , and the lower pad is detachably mounted on the lower support portion 14 .

[0076] The length-to-width ratios of the first long board 11 and the second long board 12 are both 6:1.

[0077] The upper support portion 13 and the lower support portion 14 are also respectively provided with one or more slots 16, and the slots 16 are also provided with slot threads;

[0078] In this embodiment, the slot 16 is waist-shaped and the engaging portion 222 is an umbrella-shaped cap, which is convenient for the installation of the pad 2 and also has a hook-type anti-retraction function. The sliding front section design facilitates the installation of the pad into the slot of the fusion bracket body, ensuring that there is no retreat after installation.

[0079] like Figure 3 As shown, the cushion block 2 includes an anatomical adapting portion 21 and a connecting portion 22, and the cushion block 2 is fixedly connected to the upper supporting portion 13 or the lower supporting portion 14 via the connecting portion 22;

[0080] The thickness of the anatomical adapting portion 21 is uniform, and the surface in contact with the vertebral end plate is the footprint surface, and thorn-shaped anti-slip patterns 211 are evenly arranged on the footprint surface; the depth c (the distance from the highest point to the lowest point) of the thorn-shaped structure on the anti-slip pattern 211 is 0.4 mm, and the distance d between two adjacent thorn-shaped structures is 0.8 mm. Figure 6 As shown;

[0081] The connecting portion 22 is fixedly connected to the anatomical adapting portion 21, and includes a connecting body 221 and a clamping portion 222. The anatomical adapting portion 21, the connecting body 221, and the clamping portion 222 are integrally arranged and obtained by 3D printing connection and / or machining prefabrication; a connecting thread 223 is also arranged between the connecting body 221 and the clamping portion 222;

[0082] The number of the connecting bodies 221 matches the number of the slots 16 , the size of the connecting bodies 221 matches the size of the slots 16 ; and the connecting threads 223 match the threads of the slots.

[0083] When the fusion stent body 1 is placed in ice water and is in the Martensitic phase, it can be clamped by a clamp to lower its height in the up and down directions.

[0084] The fusion stent body 1 is made of nickel-titanium alloy; the cushion block 2 is made of PEEK; in addition to the above materials, the fusion stent body 1 can also be made of other materials with shape memory function and good biocompatibility, which can be selected according to actual needs.

[0085] The nickel-titanium alloy material is a shape memory alloy with good biocompatibility. The degree of deformation of the fusion stent body 1 is related to the temperature. Specifically, when the temperature is low (in an ice water environment in this embodiment), the fusion stent body 1 can be clamped by a clamp to lower the height; when returning to normal temperature or in a body temperature environment, the fusion stent body 1 with shape memory characteristics can automatically return to its original shape and size.

[0086] In an optional embodiment, when the fusion stent body 1 is placed in ice water and is in the Martensitic phase, it can be clamped by a clamp to lower its height in the vertical direction. When it returns to normal temperature or is in a body temperature environment, the fusion stent body 1 can automatically return to its original shape and size.

[0087] In the present invention, the dimensions of the lumbar intervertebral fusion stent body 1 are as follows: length l is 36 mm, width is 10 mm, height h is 14 mm, Figure 6 shown.

[0088] The present invention also provides a method for preparing the above-mentioned lumbar intervertebral fusion stent, the preparation method comprising the following steps:

[0089] S01. Using nickel-titanium memory alloy to prepare standard parts of X-shaped fusion stent bodies 1 of different sizes that can adapt to the intervertebral space;

[0090] S02, prefabricating a spacer 2 adapted to different types / subtypes of anatomical morphologies of Chinese lumbar endplates by machining, or manufacturing a spacer 2 adapted to the anatomical shape of a specific individual lumbar endplate by 3D printing;

[0091] S03, assembling the cushion block 2 and the X-shaped fusion stent body 1 into a lumbar intervertebral fusion stent.

[0092] In step S01, the preparation method of the standard part of the fusion stent body 1 is that the sheet material is prepared into a standard part after the process steps of wire cutting, CNC milling, grinding, thermoforming, first heat treatment (350°C), first polishing (smoothness 3.2), second heat treatment, second polishing (smoothness 0.8), decontamination and cleaning, inspection, laser marking, cleaning, drying (60°C), inspection, and packaging.

[0093] The present invention also provides a bone grafting and fusion method using the above-mentioned lumbar intervertebral fusion stent, the method comprising:

[0094] S1. In ice water environment, when the lumbar intervertebral fusion cage is in the Martensitic phase, it is clamped by a clamp to slightly lower the height in the upper and lower directions, and after the spacer is installed and the whole is assembled, the target intervertebral space where the upper and lower cartilage end plates, the inner layer of the annulus fibrosus and the nucleus pulposus tissue have been completely removed is entered through an annulus fibrosus incision on the target intervertebral space;

[0095] S2. Under body temperature, the main body of the lumbar intervertebral fusion stent automatically returns to its original size and shape, and the footprint surface of the upper pad and the footprint surface of the lower pad respectively form anatomically adaptive contact with the lower end plate of the upper vertebral body and the upper end plate of the lower vertebral body in the target intervertebral space;

[0096] S3, a bone grafting and fusion method for lumbar interbody fusion surgery that mainly uses autologous bone particles obtained by decompression for bone grafting in and around the lumbar interbody fusion cage, and / or auxiliary pouring of a mixture of injectable calcium phosphate / calcium sulfate bone cement and autologous local decompression bone particles to form a concrete pouring type lumbar interbody fusion.

[0097] In an optional embodiment, in step S1, a larger fusion stent may be placed obliquely or laterally in the target intervertebral disc space, or two smaller fusion stents may be placed in parallel in the front-to-back direction.

[0098] In an optional embodiment, the composition ratio of the injectable calcium phosphate / calcium sulfate bone cement and the autologous local decompression bone particles is adjusted according to the patient's lumbar spine bone density to match the elastic modulus of the lumbar vertebrae.

[0099] In an optional embodiment, in step S3, a long-acting antibiotic may be added to the solid-liquid mixture of the injectable calcium phosphate / calcium sulfate bone cement and the autologous local decompression bone particles to prevent possible intervertebral disc infection after lumbar interbody fusion surgery.

[0100] Example 2

[0101] This embodiment provides a lumbar intervertebral fusion stent, which includes a fusion stent body 1 and a cushion block 2;

[0102] The fusion stent body 1 is X-shaped as a whole;

[0103] The cushion block 2 includes an upper cushion block and a lower cushion block; the upper cushion block and the lower cushion block are detachably mounted on the fusion stent body 1; the cushion block 2 includes an anatomical adapting portion 21 and a connecting portion 22, the length a of the anatomical adapting portion 21 is 11 mm, the width b of the anatomical adapting portion 21 is 7 mm, and the minimum thickness of the anatomical adapting portion 21 is 2 mm;

[0104] The surface where the spacer contacts the vertebral endplate is the footprint surface;

[0105] The footprint surface of the upper pad is used to abut against the lower end plate of the upper vertebral body; the footprint surface of the lower pad is used to abut against the upper end plate of the lower vertebral body.

[0106] The fusion stent body 1 is an integrated structure, including two long plates with waist-shaped holes 15, namely a first long plate 11 and a second long plate 12. The two long plates are of the same length, and the first long plate 11 and the second long plate 12 cross to form an X shape; the setting of the waist-shaped holes 15 can make the structure of the fusion stent have a certain elastic deformation ability.

[0107] Both ends of the first long board 11 and the second long board 12 are bent and extended, and are provided with horizontal support parts, namely, an upper support part 13 and a lower support part 14, which are provided at the ends of the long boards. The support parts are fixedly provided on the long boards in an integrated manner.

[0108] The intersection of the two long plates is thicker and the ends are thinner; the thickness of the supporting portion is uniform.

[0109] The upper pad is detachably mounted on the upper support portion 13 , and the lower pad is detachably mounted on the lower support portion 14 .

[0110] The length-to-width ratio of the first long board 11 and the second long board 12 is 7:1.

[0111] The upper support portion 13 and the lower support portion 14 are also respectively provided with one or more slots 16, and the slots 16 are also provided with slot threads;

[0112] In this embodiment, the slot 16 is circular and the engaging portion 222 is semi-umbrella-shaped, so as to facilitate the installation of the cushion block 2.

[0113] The cushion block 2 includes an anatomical adapting portion 21 and a connecting portion 22, and the cushion block 2 is fixedly connected to the upper supporting portion 13 or the lower supporting portion 14 via the connecting portion 22;

[0114] The anatomical adaptable portion 21 has a uniform thickness, and the surface of the footprint surface is uniformly provided with striped anti-slip patterns 211; the depth of the striped structure on the anti-slip pattern 211 (the distance from the highest point to the lowest point) is 0.5 mm, and the distance between two adjacent striped structures is 1 mm;

[0115] The connecting portion 22 is fixedly connected to the anatomical adapting portion 21, and includes a connecting body 221 and a clamping portion 222. The anatomical adapting portion 21, the connecting body 221, and the clamping portion 222 are integrally arranged and prefabricated by 3D printing and / or machining. A connecting thread 223 is also arranged between the connecting body 221 and the clamping portion 222.

[0116] The number of the connecting bodies 221 matches the number of the slots 16 , the size of the connecting bodies 221 matches the size of the slots 16 ; and the connecting threads 223 match the threads of the slots.

[0117] The fusion stent body 1 is in the Martens phase when in an ice water environment, and can be deformed in the up and down directions to reduce the height by being clamped by a dedicated clamp.

[0118] The fusion stent body 1 is made of nickel-titanium alloy; the cushion block 2 is made of PEEK; in addition to the above materials, the fusion stent body 1 can also be made of other materials with shape memory function, which can be selected according to actual needs.

[0119] The nickel-titanium alloy material is a shape memory alloy with good biocompatibility. The degree of deformation of the fusion stent body 1 is related to the temperature. Specifically, when the temperature is low, the fusion stent body 1 can be lowered in the vertical direction by clamping with a clamp; when the normal temperature or body temperature environment is restored, the fusion stent body 1 can automatically return to its original shape and size.

[0120] In an optional embodiment, the fusion stent body 1 is in a Martens phase in an ice water environment, and can be lowered in the vertical direction by clamping with a clamp. When returning to normal temperature or in a body temperature environment, the fusion stent body 1 with shape memory characteristics automatically returns to its original shape and size.

[0121] In the present invention, the dimensions of the lumbar intervertebral fusion stent body 1 are as follows: length l is 26 mm, width is 10 mm, and height h is 12 mm.

[0122] Example 3

[0123] When preparing the lumbar intervertebral fusion stent of the present invention, the preparation method comprises the following steps:

[0124] S01. Using nickel-titanium memory alloy to prepare standard parts of X-shaped fusion stent bodies 1 of different sizes that can adapt to the intervertebral space;

[0125] S02, a pad 2 prefabricated by machining to match the anatomical morphology of different types / subtypes of Chinese lumbar endplates, or a pad 2 prefabricated by 3D printing to match the anatomical shape of a specific individual lumbar endplate;

[0126] S03, assembling the cushion block 2 and the X-shaped fusion stent body 1 into a lumbar intervertebral fusion stent.

[0127] In step S01, the preparation method of the standard part of the fusion stent body 1 is that the sheet material is prepared into a standard part after the process steps of wire cutting, CNC milling, grinding, thermoforming, first heat treatment (350°C), first polishing (smoothness 3.2), second heat treatment, second polishing (smoothness 0.8), decontamination and cleaning, inspection, laser marking, cleaning, drying (60°C), inspection, and packaging.

[0128] In step S02, the design and preparation of a pad adapted to the anatomical shape of a specific individual lumbar endplate by 3D printing includes the following steps:

[0129] Step S021, reconstructing the patient's vertebral CT image data in three dimensions to obtain a three-dimensional vertebral model; the slice thickness during CT scanning is ≤1mm;

[0130] Step S022, importing the model file of the prefabricated lumbar intervertebral fusion stent into the three-dimensional vertebral model in step S021 and placing it at the position to be surgically implanted;

[0131] Step S023, extracting upper and lower vertebral body surfaces that are in direct contact with the pad of the lumbar intervertebral fusion bracket, and regenerating a pad model file by using the upper and lower vertebral body surfaces as the upper surface of the pad;

[0132] Step S024: obtaining a personalized designed cushion block through 3D printing according to the regenerated cushion block model file.

[0133] Example 4

[0134] The lumbar intervertebral fusion stent of the present invention comprises the following steps when used for bone grafting and fusion:

[0135] S1. Place the main body of the lumbar intervertebral fusion stent to be implanted in an ice water environment. The main body of the lumbar intervertebral fusion stent is in the Martens phase in the ice water environment. Use a matching special clamping tool to clamp and apply force to deform the main body of the fusion stent in the up and down directions to reduce the height. Then install four pads. Then, through an annulus fibrosus fissure incision on the target intervertebral space, place the lumbar intervertebral fusion stent into the target intervertebral space where the upper and lower cartilage end plates, the inner annulus fibrosus and the nucleus pulposus tissue have been completely removed. After the lumbar intervertebral fusion stent enters the target intervertebral space, before returning to its original size and shape, it can be moved in the target intervertebral space to a suitable position considered by the surgeon, that is, it can be adjusted from the front-to-back direction at the time of entry to an oblique or horizontal direction relative to the median sagittal plane of the human body, and can be placed in a relatively forward position in the target intervertebral space.

[0136] S2. Under the action of body temperature, the lumbar intervertebral fusion stent returns to its original size and shape, and the footprint surface of the upper pad and the footprint surface of the lower pad are respectively in contact with the lower end plate of the upper vertebral body and the upper end plate of the lower vertebral body of the target intervertebral space, so that the lumbar intervertebral fusion stent as a whole is tightly supported in the target intervertebral space, and the lumbar intervertebral fusion stent serves as a "reinforced skeleton" of the target intervertebral space;

[0137] S3. Then, the autologous bone particles obtained by decompression are used for bone grafting in and around the lumbar intervertebral fusion bracket, and a mixture of injectable calcium phosphate / calcium sulfate bone cement and autologous local decompression bone particles is poured auxiliaryly. The injectable calcium phosphate / calcium sulfate bone cement and autologous local decompression bone particles correspond to each other as "cement" and "stone" one by one, thus forming a concrete pouring type lumbar intervertebral fusion bone grafting fusion method.

[0138] A shape-memory lumbar interbody fusion stent is used as the "reinforced skeleton" of the intervertebral space, and a mixture of injectable calcium phosphate / calcium sulfate bone cement and autologous local decompression bone particles is poured as "cement" and "stone", forming a lumbar interbody fusion surgery that is different from the previous traditional "prefabricated pre-implanted bone impact" type.

[0139] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0140] The terms "comprising", "containing", "including" or "comprising" used in the embodiments of the present invention indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof. This specification describes exemplary embodiments by reference to idealized exemplary cross-sectional views and / or plan views and / or stereoscopic views. The term "and / or" includes any or all combinations of the associated listed items. When an element is described as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements.

[0141] Similarly, when an element is described as being "on" another element, it can be directly on the other element or there can be an intermediate element. In contrast, the term "directly" means that there are no intermediate elements. In addition, although the terms first, second, third, etc. can be used to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Therefore, without violating the teachings of the present application, an element referred to as a first element in some embodiments may be referred to as a second element in other embodiments. The same reference numerals or reference markers represent the same elements.

[0142] Due to, for example, manufacturing techniques and / or tolerances, there may be deviations from the illustrated shapes. Exemplary embodiments should not be construed as limited to regions of the illustrated shapes, but are intended to include deviations in shapes caused by, for example, manufacturing. The illustrated regions are schematic in nature, and the shapes are not intended to depict the actual shape of a device region and are not intended to limit the scope of the exemplary embodiments.

[0143] The protection content of the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the inventive concept, changes and advantages that can be thought of by those skilled in the art are included in the present invention and are protected by the attached claims.

Claims

1. A lumbar intervertebral fusion stent, characterized in that: The fusion stent comprises a fusion stent body (1) and a cushion block (2); The fusion stent body (1) is X-shaped as a whole; the length of the fusion stent body (1) is 20-40 mm, the width of the fusion stent body (1) is 10-12 mm, and the height of the fusion stent body (1) is 6-14 mm; The cushion block (2) comprises an upper cushion block and a lower cushion block; the upper cushion block and the lower cushion block are detachably mounted on the fusion stent body (1).

2. The lumbar interbody fusion stent according to claim 1, characterized in that: The fusion stent body (1) is an integrated structure, comprising two long plates each having a waist-shaped hole (15), namely a first long plate (11) and a second long plate (12), wherein the first long plate (11) and the second long plate (12) cross to form an X shape; Both ends of the first long plate (11) and the second long plate (12) are bent and extended, and are provided with horizontal support parts, namely an upper support part (13) and a lower support part (14), which are arranged at the ends of the long plates; the thickness of the support parts is uniform, and the upper support part (13) and the lower support part (14) are parallel; and / or, The length-to-width ratios of the first long plate (11) and the second long plate (12) are both (3-10):

1.

3. The lumbar intervertebral fusion stent according to claim 2, characterized in that: The upper pad is detachably mounted on the upper support portion (13), and the lower pad is detachably mounted on the lower support portion (13); the pad (2) is prefabricated by machining or obtained by personalized 3D printing according to the anatomical morphology type / subtype of the Chinese lumbar endplate, and the footprint surface of the pad (2) in contact with the vertebral endplate is adapted to the anatomical morphology or anatomical morphology type / subtype of the vertebral endplate of the specific patient's target intervertebral space.

4. The lumbar interbody fusion stent according to claim 2, characterized in that: The upper support portion (13) and the lower support portion (14) are also respectively provided with one or more slots (16), and the slots (16) are also provided with slot threads.

5. The lumbar intervertebral fusion stent according to claim 4, characterized in that: The cushion block (2) comprises an anatomical adapting portion (21) and a connecting portion (22), and the cushion block (2) is fixedly connected to the upper supporting portion (13) or the lower supporting portion (14) via the connecting portion (22); the anatomical adapting portion (21) has a length of 10-12 mm, a width of 6-10 mm, and a minimum thickness of 2 mm; The surface of the anatomical adaptor (21) in contact with the vertebral endplate is a footprint surface, and the surface of the footprint surface is evenly provided with anti-slip patterns (211) with thorn-like and / or stripe-like structures; the depth of the thorn-like and / or stripe-like structures on the anti-slip patterns (211) is 0.2-1 mm, and the distance between two adjacent thorn-like and / or stripe-like structures is 0.5-1.5 mm; The connecting portion (22) is fixedly connected to the anatomical adapting portion (21), and comprises a connecting body (221) and a clamping portion (222); the anatomical adapting portion (21), the connecting body (221), and the clamping portion (222) are integrally arranged; a connecting thread (223) is further arranged between the connecting body (221) and the clamping portion (222); The number of the connecting bodies (221) matches the number of the slots (16); the size of the connecting bodies (221) matches the size of the slots (16); and the connecting threads (223) match the threads of the slots.

6. The lumbar intervertebral fusion stent according to claim 1, characterized in that: The fusion stent body (1) is in a martensitic phase in an ice water environment and can be deformed in the up and down directions by clamping with a tool, thereby reducing the height.

7. The lumbar interbody fusion stent according to any one of claims 1 to 6, characterized in that: The fusion stent body (1) is made of nickel-titanium alloy; the cushion block (2) is made of PEEK.

8. A method for preparing a lumbar intervertebral fusion stent according to any one of claims 1 to 7, characterized in that: The steps include: S01. Using nickel-titanium memory alloy to prepare standard parts of X-shaped fusion stent bodies (1) of different sizes; S02. Prefabricate a spacer (2) that is compatible with different types / subtypes of anatomical morphologies of Chinese lumbar endplates by machining, or manufacture a spacer (2) that is compatible with the anatomical shape of a specific individual lumbar endplate by 3D printing; S03, assembling the cushion block (2) and the X-shaped fusion bracket body (1) into a lumbar intervertebral fusion bracket.

9. The preparation method according to claim 8, characterized in that: In step S02, the design and preparation of a pad adapted to the anatomical shape of a specific individual lumbar endplate by 3D printing includes the following steps: Step S021, reconstructing the patient's vertebral CT image data in three dimensions to obtain a three-dimensional vertebral model; Step S022, importing the model file of the prefabricated lumbar intervertebral fusion stent into the three-dimensional vertebral model in step S021 and placing it at the position to be surgically implanted; Step S023, extracting upper and lower vertebral body surfaces that are in direct contact with the pad of the lumbar intervertebral fusion bracket, and regenerating a pad model file by using the upper and lower vertebral body surfaces as the upper surface of the pad; Step S024: obtaining a personalized designed cushion block through 3D printing according to the regenerated cushion block model file.

10. A method for bone grafting and fusion using the lumbar intervertebral fusion stent according to any one of claims 1 to 7, characterized in that: The method comprises: S1. In an ice water environment, when the main body of the lumbar intervertebral fusion stent of suitable height is in the Martensitic phase, it can be lowered in the vertical direction, and then a pad with an anatomically adapted footprint surface is installed to form a whole. Then, the target intervertebral space where the upper and lower cartilage end plates, the inner annulus fibrosus and the nucleus pulposus tissue have been completely removed is entered through an annulus fibrosus incision on the target intervertebral space; S2. Under body temperature, the main body of the lumbar intervertebral fusion stent automatically returns to its original size and shape, and the footprint surface of the upper pad and the footprint surface of the lower pad respectively contact with the lower end plate of the upper vertebral body and the upper end plate of the lower vertebral body in the target intervertebral space to form anatomically adapted contact; S3. Compression bone grafting is mainly performed with autologous bone particles obtained by decompression in and around the lumbar interbody fusion scaffold, and / or a fusion method is used to cast a mixture of injectable calcium phosphate / calcium sulfate bone cement and autologous local decompression bone particles to increase the force-bearing area of ​​the vertebral endplate and reduce the risk of scaffold settlement.

11. Use of the lumbar interbody fusion stent according to any one of claims 1 to 7 in bone graft fusion.

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