Integrated Injection Implementation Method and Device of Injectable Bone Substitute in Vertebroplasty

Abstract

An integrated injection implementation method and device of an injectable bone substitute in vertebroplasty, belonging to the field of medical devices. A shape memory alloy guide needle is inserted into a hollow tube for thermal pre - shaping, and the two are integrally and synchronously pushed into the vertebral body. Under the guidance of the shape memory alloy guide needle, the hollow tube rapidly rebounds to its original curvature through internal stress, forming the boundary of the filling space for the injectable bone substitute or acting as a boundary fence for the filling space; the injectable bone substitute is injected through the hollow tube to the designated position; at the designated part in the vertebral body, the injectable bone substitute fills the hollow tube and the filling space surrounded by it. It enables the injection area of the injectable bone substitute to be programmable, and integrates multiple steps such as puncture, distraction, injection of implants and bone cement, and shaping in vertebroplasty; all steps are carried out synchronously, greatly optimizing the operation process, shortening the operation time, and reducing the operation difficulty. It can be widely used in the design and manufacturing fields of orthopedic implant injection devices.

Description

Technical Field

[0001] The present invention belongs to the field of surgical instruments, devices or methods, and in particular to a method and device for injecting and shaping a bone substitute into a vertebral body. Background Art

[0002] Percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) have been used clinically for many years, and the main clinical problems are:

[0003] 1) Uncertainty in the bone cement injection area.

[0004] In traditional balloon surgery, the injected bone cement has no boundary constraints, is freely diffused and filled, and has poor controllability. Therefore, it is difficult to accurately calculate the injection volume before surgery. Too little injection will make it difficult to achieve the molding effect, while too much injection will cause the risk of leakage.

[0005] 2) High probability of complications caused by bone cement leakage.

[0006] When there is micro-damage to the outer cortical bone of the vertebral body, leakage is inevitable. Once it leaks into the spinal canal and intervertebral foramen, it is likely to cause neurological symptoms. Leakage into the veins will cause pulmonary embolism and endanger life.

[0007] 3) The mechanical bearing effect is poor.

[0008] Because the injected bone cement is diffuse and has no fixed spatial structure, it cannot form the maximum load in the vertical direction. Improper spatial distribution of bone cement causes the bone cement to be subjected to uneven force, making it easy to break, which in turn leads to secondary collapse of the vertebral body and requires repair surgery.

[0009] 4) In traditional PKP, vertebral distraction and bone cement injection need to be performed in steps, which are cumbersome. Most operations, such as the degree of distraction, the amount of bone cement injected, and the injection rate, need to be judged based on the operator's experience. The tolerance is low, the repeatability is poor, and extremely high operating skills are required.

[0010] How to plan and define the injection molding area of ​​bone cement before the operation, reduce or avoid bone cement leakage, and integrate vertebral distraction and bone cement injection, reduce the requirements or dependence on the operator's operating proficiency, and make the injected bone cement have better mechanical bearing effect, is a technical problem that we have been trying to solve in actual work. Summary of the invention

[0011] The technical problem to be solved by the present invention is to provide an integrated injection implementation method and device for an injectable bone substitute in vertebroplasty. A linear shape memory alloy guide needle is inserted into a biocompatible polymer hollow tube, and thermal pre - shaping is performed. Then, the two are integrally and synchronously pushed into the vertebral body. Under the guidance of the shape memory alloy guide needle, the biocompatible polymer hollow tube rapidly rebounds to its original curvature through internal stress, thereby forming the boundary of the filling space for the injectable bone substitute or serving as a boundary fence for the filling space. Then, the injectable bone substitute is injected through the hollow tube to a specified position. Further, at a specified part within the vertebral body, the injectable bone substitute fills the biocompatible polymer hollow tube and the filling space surrounded by it. This makes the injection area of the injectable bone substitute programmable, integrating multiple steps such as puncture, distraction, injection of implants and bone cement, and shaping in vertebroplasty. All steps are carried out synchronously, greatly optimizing the operation process, shortening the operation time, and reducing the operation difficulty.

[0012] The technical solution of the present invention is: to provide an integrated injection implementation method for an injectable bone substitute in vertebroplasty, characterized in that:

[0013] 1) Perform pre - bending pretreatment on the biocompatible polymer hollow tube and seal its front end;

[0014] 2) Insert a linear shape memory alloy guide needle into the biocompatible polymer hollow tube, with the shape memory alloy guide needle forming the "needle core" of the biocompatible polymer hollow tube, making the two into an integral structure;

[0015] 3) Perform thermal pre - shaping on the biocompatible polymer hollow tube with the inserted needle core to form a required pre - defined structural shape;

[0016] 4) Use a pushing and driving device with a puncture sleeve at least including a straight - tube - shaped section to forcibly push the biocompatible polymer hollow tube with the pre - defined structural shape and the shape memory alloy guide needle into the vertebral body in a linear structural form synchronously;

[0017] 5) At a specified part within the vertebral body, after the biocompatible polymer hollow tube is separated from the straight - tube - shaped puncture sleeve, under the guidance of the shape memory alloy guide needle, it rapidly rebounds to its original curvature through internal stress and is consistent with the pre - defined structural shape;

[0018] 6) Continue to push the biocompatible polymer hollow tube and the shape memory alloy guide needle synchronously;

[0019] 7) Under the guidance of the shape memory alloy guide needle, the biocompatible polymer hollow tube continues to form a pre - defined structural shape at a specified part within the vertebral body until it completely conforms to the required shape or height, and the vertebral body is distracted to the required interval;

[0020] 8) Withdraw the shape memory alloy needle from the biocompatible polymer hollow tube;

[0021] 9) Inject the injectable bone substitute into the biocompatible polymer hollow tube;

[0022] 10) Guided and restricted by the biocompatible polymer hollow tube, the injectable bone substitute is continuously injected into the designated site within the vertebral body;

[0023] 11) At the designated site within the vertebral body, the injectable bone substitute fills the biocompatible polymer hollow tube, or the injectable bone substitute fills the biocompatible polymer hollow tube and the filling space surrounded by it;

[0024] 12) Cut off the biocompatible polymer hollow tube that extends beyond the outside of the vertebral body or the required length;

[0025] 13) The injectable bone substitute forms a three-dimensional filling body at the designated site within the vertebral body;

[0026] 14) After the three-dimensionally filled injectable bone substitute solidifies, it forms a load-bearing bone substitute that has the same or similar strength as the vertebral body at the location;

[0027] The integrated injection implementation method described above realizes the moldability planning and controllability of the injectable bone substitute by pushing / injecting the biocompatible polymer hollow tube with the shape memory alloy guide needle acting as the "needle core" to the designated site within the vertebral body to form the boundary of the filling space or act as the boundary fence of the filling space, eliminating the leakage risk of the injectable bone substitute, and then integrating multiple steps of puncture, distraction, injection of implants and injectable bone substitute, molding, and solidification in vertebroplasty; thereby optimizing the operation process, shortening the operation time, and reducing the operation difficulty.

[0028] Specifically, the injectable bone substitute at least includes injectable bone cement, CPC, or gel.

[0029] The moldability planning and controllability of the injectable bone substitute at least include the moldability planning of the injection area of the injectable bone substitute, the controllability of the implantation position of the injectable bone substitute, the controllability of the injection volume of the injectable bone substitute, the controllability of the distraction / molding effect of the injectable bone substitute, and the controllability of the mechanical support of the injectable bone substitute.

[0030] The predetermined structural shape at least includes a helical coil structure.

[0031] Further, a pre-bending pretreatment is performed on the biocompatible polymer hollow tube, including processing / setting annular, serpentine or helical cutting grooves on the outer surface of the biocompatible polymer hollow tube to facilitate the thermal pre-forming and the restoration of the predetermined structural shape of the biocompatible polymer hollow tube.

[0032] The technical solution of the present invention also provides an integrated injection device for an injectable bone substitute in vertebroplasty, characterized in that:

[0033] The integrated injection device at least includes a pushing drive device, a biocompatible polymer hollow tube and a linear shape memory alloy guide needle;

[0034] The pushing drive device has a straight tubular puncture sleeve;

[0035] The shape memory alloy guide needle is arranged through the biocompatible polymer hollow tube;

[0036] The front end of the biocompatible polymer hollow tube is closed;

[0037] Wherein, the pushing drive device is used to push the biocompatible polymer hollow tube and the shape memory alloy guide needle to a specified position inside the vertebra;

[0038] The shape memory alloy guide needle is used to guide the bending of the biocompatible polymer hollow tube, discharge most of the air in the hollow tube, and can prevent the biocompatible polymer hollow tube from squeezing the injection channel when bending, maintaining a good injection channel for the injectable bone substitute;

[0039] The biocompatible polymer hollow tube constitutes the boundary or boundary fence of the injection channel of the injectable bone substitute and the filling space of the injectable bone substitute.

[0040] Further, after the biocompatible polymer hollow tube and the shape memory alloy guide needle that have been thermally pre-formed are pre-shaped, they are placed into the pushing drive device; the puncture sleeve of the pushing drive device is inserted to a specified position inside the required vertebra; the pushing drive device, by means of the puncture sleeve, continuously and synchronously sends out the pre-shaped biocompatible polymer hollow tube and the shape memory alloy guide needle integrally; under the forced restraint and guidance of the straight tubular puncture sleeve, the pre-shaped biocompatible polymer hollow tube and the shape memory alloy guide needle are sent to a specified position inside the vertebra in a straight tube / linear shape; after leaving the straight tubular puncture sleeve, the biocompatible polymer hollow tube rebounds rapidly to its original curvature under the guidance of the shape memory alloy guide needle, and is restored / kept consistent with the shape after thermal pre-forming.

[0041] The integrated injection device described above continuously and synchronously pushes a biocompatible polymer hollow tube and a shape memory alloy guide needle, thereby forming an injectable bone substitute filling space in the vertebral body that is the same as or similar to the shape of the biocompatible polymer hollow tube after thermal pre - shaping.

[0042] Furthermore, on one side of the biocompatible polymer hollow tube, a plurality of side holes are provided; when the biocompatible polymer hollow tube is thermally pre - shaped, the side holes face the inside of the filling space surrounded by the biocompatible polymer hollow tube; through pushing / injecting, the injectable bone substitute fills the internal space of the biocompatible polymer hollow tube; or, through pushing / injecting, the injectable bone substitute passes through the biocompatible polymer hollow tube with a multi - side - hole structure and fills the biocompatible polymer hollow tube and the three - dimensional filling space it encloses.

[0043] The technical solution of the present invention also provides an integrated injection device for an injectable bone substitute in vertebroplasty, characterized in that:

[0044] The integrated injection device includes a pushing drive device, a flexible shaft tube, a head drill bit, and a linear shape memory alloy guide needle; the head drill bit is arranged at the head end of the flexible shaft tube; the tail end of the flexible shaft tube is connected to the pushing drive device; the linear shape memory alloy guide needle penetrates through the flexible shaft tube; the pushing drive device has a straight tubular puncture sleeve; the shape memory alloy guide needle is used to guide the bending of the flexible shaft tube.

[0045] Among them, the pushing drive device drives the head drill bit to rotate through the flexible shaft tube, and along the path guided by the shape memory alloy guide needle, pushes the flexible shaft tube, the head drill bit, and the shape memory alloy guide needle to a specified position inside the vertebral body; at the same time, the pushing drive device continuously and synchronously sends out the flexible shaft tube, the shape memory alloy guide needle, and the head drill bit integrally by means of the puncture sleeve.

[0046] The flexible shaft tube constitutes the injection channel of the injectable bone substitute and the boundary or boundary fence of the injectable bone substitute filling space.

[0047] The integrated injection device continuously excavates a spiral bone tunnel for accommodating the flexible shaft tube in the vertebral body in the mode of shield tunneling.

[0048] Specifically, insert the shape memory alloy guide needle into the flexible shaft tube, after thermal pre - shaping, place it into the pushing drive device; insert the puncture sleeve of the pushing drive device to a specified position inside the required vertebral body; the pushing drive device continuously and synchronously sends out the thermally pre - shaped flexible shaft tube and the shape memory alloy guide needle integrally by means of the puncture sleeve.

[0049] Under the forced restraint and guidance of a straight tubular puncture sleeve, the flexible soft shaft tube and the shape memory alloy guide needle after thermal pre - shaping are sent to a specified position inside the vertebral body in a straight tube / linear shape; the pushing and driving device drives the head drill to rotate through the flexible soft shaft tube, forming a shield tunneling mode; after leaving the straight tubular puncture sleeve, the flexible soft shaft tube rebounds rapidly to its original curvature under the guidance of the shape memory alloy guide needle, and is restored / kept consistent with the shape after thermal pre - shaping.

[0050] The head drill mentioned above creates a spiral - shaped bone tunnel inside the vertebral body under the guidance of the shape memory alloy guide needle; the flexible soft shaft tube forms a space for filling injectable bone substitute inside the vertebral body that is the same as or similar to the shape of the shape memory alloy guide needle after thermal pre - shaping along the spiral - shaped bone tunnel under the guidance of the shape memory alloy guide needle.

[0051] Furthermore, the flexible soft shaft tube includes a four - layer structure. Its outer layer is a degradable polymer tube; after the bone tunnel tunneling is completed, it remains in the vertebral body, and then an injectable bone substitute is injected into it; its middle layer is a wear - resistant tube, and the outer diameter of the wear - resistant tube is equal to the inner diameter of the outer layer tube; after the bone tunnel tunneling is completed, the wear - resistant tube, the inner driving shaft, the shape memory alloy guide needle and the puncture sleeve are all pulled out together; its inner layer is a flexible rotating shaft for driving the drill to rotate, and the diameter of the flexible rotating shaft is half of that of the wear - resistant tube, forming a hollow pipeline between the two for discharging bone debris; after the bone tunnel tunneling is completed, the flexible rotating shaft, the inner driving shaft, the shape memory alloy guide needle and the puncture sleeve are all pulled out together; inside the flexible rotating shaft, there is a hollow central axis layer, and the central axis layer is the hollow structure inside the flexible driving shaft, and its diameter is large enough for the shape memory alloy guide needle to freely pass through.

[0052] Among them, the gap between the outer layer and the middle layer forms an annular tubular structure for providing a discharge channel for the bone debris drilled out by the drill.

[0053] Even further, the shape of the shape memory alloy guide needle after thermal pre - shaping at least includes a spiral - shaped structure; on the outer surface of the biocompatible polymer hollow tube or the flexible soft shaft tube, there are annular, snake - shaped or spiral - shaped grooves.

[0054] Compared with the prior art, the advantages of the present invention are:

[0055] 1. Through an injectable instrument / implant (i.e., the aforementioned biocompatible polymer hollow tube or flexible soft shaft tube), a definite space for filling injectable bone substitute is formed inside the vertebral body, making the injection area of the injectable bone substitute have planability. Through the pre - established spatial structure before surgery, the injection amount of bone cement can be calculated.

[0056] 2. Through the spatial structure and dosage of the injectable bone substitute, the mechanical effect it bears can be accurately known, ensuring the consistency of the mechanical properties inside and outside the implanted object.

[0057] 3. Avoid and eliminate the leakage risk of injectable bone substitutes through the fence structure formed by the injectable device / implant, and avoid various complications caused thereby;

[0058] 4. Puncture, tunneling and forming of bone tunnels, and injection of injectable bone substitutes can all be completed at one time, simplifying the operation steps and raising vertebroplasty from an empirical operation to a digital, mechanized, standard and quantifiable level. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 is a schematic flow chart of the method of the present invention;

[0060] Figure 2 is a schematic structural diagram of the biocompatible polymer hollow tube of the present invention;

[0061] Figure 3 is a schematic structural diagram of a biocompatible polymer hollow tube with grooves on the periphery;

[0062] Figure 4 is a schematic structural diagram of a helical biocompatible polymer hollow tube;

[0063] Figure 5 is a schematic structural diagram of a helical biocompatible polymer hollow tube with grooves;

[0064] Figure 6 is a schematic structural diagram of the pushing drive device;

[0065] Figure 7 is a schematic diagram of the working process of the pushing drive device;

[0066] Figure 8 is a schematic diagram of the synchronous puncture of the biocompatible polymer hollow tube and the shape memory alloy guide needle of the present invention;

[0067] Figure 9 is a schematic diagram of the shape memory alloy needle starting to bend into a helix;

[0068] Figure 10 is a schematic diagram after the biocompatible polymer hollow tube completes the entire bending process;

[0069] Figure 11 is a schematic diagram of the structural shape of the shape memory alloy needle in the filling space;

[0070] Figure 12 is a schematic diagram of withdrawing the shape memory alloy needle;

[0071] Figure 13 Schematic diagram of starting to inject bone cement;

[0072] Figure 14It is a schematic diagram when the bone cement completely fills the biocompatible polymer hollow tube and has not yet overflowed from the side holes;

[0073] Figure 15 It is a schematic diagram when the bone cement completely fills the biocompatible polymer hollow tube and overflows from the side holes;

[0074] Figure 16 It is a schematic diagram of the structure of the shield drill bit and its flexible rotating shaft;

[0075] Figure 17 It is a schematic diagram of the structure of the flexible shaft tube;

[0076] Figure 18 It is a schematic cross-sectional structure diagram of the flexible shaft tube;

[0077] Figure 19 It is Figure 18 The partial enlarged structure diagram of part A of;

[0078] Figure 20 It is a schematic diagram when the biocompatible polymer hollow tube punctures to the injection starting point;

[0079] Figure 21 It is a schematic diagram when the drill bit reaches the starting point of the pedicle;

[0080] Figure 22 It is a schematic diagram when the guide wire guides the flexible drill bit to simultaneously excavate the bone tunnel;

[0081] Figure 23 It is a schematic diagram when the bone tunnel excavation is completed;

[0082] Figure 24 It is a schematic diagram when the bone cement filling is completed.

[0083] In the figure, 0 is the vertebral body, 1 is the biocompatible polymer hollow tube, 1A is the spiral tube, 2 is the closed end, 3 is the inner hole, 4 is the cutting groove, 5 is the shape memory alloy guide pin, 6 is the puncture sleeve, 6A is the puncture needle, 7 is the pushing drive device, 8 is the injectable bone substitute, 9 is the bone substitute, 10 is the drive handle, 11 is the drive shaft, 12 is the belt, 13A is the driving roller, 13B is the driven roller, 14 is the injectable spiral tube bin, 20 is the head drill bit, 21 is the degradable tube, 22 is the wear-resistant tube, 23 is the flexible rotating shaft, 24 is the hollow core layer, 25 is the annular tube. Specific implementation mode

[0084] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0085] Figure 1 Among them, the technical solution of the present invention provides an integrated injection implementation method of an injectable bone substitute in vertebral body forming, and its inventive point lies in:

[0086] A biocompatible polymer hollow tube (abbreviated as hollow tube or tube) 1 is pre-bent and its front end is sealed to form a closed end 2;

[0087] Insert a linear memory alloy guide needle 5 into the biocompatible polymer hollow tube, and the memory alloy guide needle constitutes the "needle core" of the hollow tube, so that the two become an integrated structure;

[0088] Thermally preforming the biocompatible polymer hollow tube with the needle core inserted therein to form a desired predetermined structural shape;

[0089] A pushing drive device including at least one straight tube segment of the puncture sleeve 6 is used to force the biocompatible polymer hollow tube of a predetermined structure and the memory alloy guide needle to be synchronously pushed into the vertebral body in a straight structure under the action of the puncture sleeve;

[0090] At the designated position in the vertebral body, the biocompatible polymer hollow tube, after being separated from the straight tube segment puncture sleeve, is guided by the memory alloy guide needle and quickly rebounds to the original curvature through internal stress, keeping consistent with the predetermined structural shape;

[0091] Continue to push the biocompatible polymer hollow tube and memory alloy guide needle simultaneously;

[0092] Under the guidance of the memory alloy guide needle, the biocompatible polymer hollow tube continues to bend at the designated position in the vertebral body to form a predetermined structural shape until it fully meets the required shape or height, and expands the vertebral body to the required interval;

[0093] Extracting the memory alloy needle from the biocompatible polymer hollow tube;

[0094] injecting an injectable bone substitute 8 into the biocompatible polymer hollow tube;

[0095] Through the guidance and restriction of the biocompatible polymer hollow tube, the injectable bone substitute is continuously injected into the designated location in the vertebral body;

[0096] At a designated location in the vertebral body, the injectable bone substitute fills the biocompatible polymer hollow tube, or the injectable bone substitute fills the biocompatible polymer hollow tube and the filling space surrounded by it;

[0097] The injectable bone substitute forms a three-dimensional filling body at the designated location within the vertebral body;

[0098] After solidification, the three-dimensionally filled injectable bone substitute forms a pressure-bearing bone substitute with the same or similar strength as the vertebral body at the location;

[0099] The described integrated injection implementation method realizes the moldability and controllability of injectable bone substitutes by pushing / injecting a biocompatible polymer hollow tube with a shape memory alloy guide needle acting as the "needle core" to a designated position within the vertebral body, forming the boundary of the filling space or acting as the boundary fence of the filling space, eliminating the leakage risk of injectable bone substitutes, and then integrally realizing multiple steps of puncture, distraction, injection of implants and injectable bone substitutes, molding, and curing in vertebroplasty; thereby optimizing the operation process, shortening the operation time, and reducing the operation difficulty.

[0100] It should be noted that the technical solution involved in the present invention belongs to orthopedic implants and corresponding supporting tools. More specifically, it relates to a molding method and device for an injectable bone substitute (also known as injectable bone cement, abbreviated as bone cement), and does not belong to the methods for diagnosing and treating diseases.

[0101] In the technical solution of the present invention, the biocompatible polymer hollow tube can be made of one of PEEK (poly-ether-ether-ketone, polyetheretherketone resin), PLGA (poly(lactic-co-glycolic acid, copolymer of glycolic acid and lactic acid)), PCL (Polycaprolactone, polycaprolactone), PGA (Polyglycolic acid, polyglycolic acid), or PLA (polylactic acid, polylactic acid).

[0102] The moldability and controllability of the injectable bone substitute at least include the moldability of the injection area of the injectable bone substitute, the controllability of the implantation position of the injectable bone substitute, the controllability of the injection volume of the injectable bone substitute, the controllability of the distraction / molding effect of the injectable bone substitute, and the controllability of the mechanical support of the injectable bone substitute.

[0103] The predetermined structural shape in the technical solution of the present invention at least includes a helical coiled tube structure.

[0104] In addition, although the technical solution of this patent is described with injectable bone substitutes, it is applicable to, including but not limited to, injectable bone cement, CPC (Calcium Phosphate Cement, calcium phosphate bone cement), gels, etc.; this technical solution is not only applicable to the commonly used bone substitutes at the present stage, but also applicable to future injectable bone materials with better performance with the progress of materials science.

[0105] Although the technical solution of this patent is described with a helical molding area, this method can achieve various injection molding structures other than helical shapes and can construct any spatial shape according to clinical needs.

[0106] Obviously, the technical solution of this patent integrates multiple steps in vertebroplasty, such as puncture, distraction, injection of implants and bone cement, and shaping; multiple steps are carried out synchronously, greatly optimizing the operation process, shortening the operation time, and reducing the operation difficulty.

[0107] Example:

[0108] Example 1:

[0109] 1. Preparation of materials:

[0110] a) Select PEEK thin-walled pipe as the biocompatible polymer hollow tube:

[0111] The outer diameter of the pipe is about 4 mm and the thickness is about 1.5 mm.

[0112] b) Pretreatment of PEEK pipe pre-bending:

[0113] i. Seal the starting end or the first end of the biocompatible polymer hollow tube 1 (i.e., the end first injected into the vertebra 0), and form a closed end 2 at its front end (as shown in Figure 2 ).

[0114] ii. Drill holes on the inner side of the pipe to form inner holes 3. The hole diameter of the inner holes matches the flow of bone cement, about 2 mm. Since the starting end is sealed, after the bone cement is injected into the pipe, it can be injected into the inner space of the spiral pipe through the inner holes.

[0115] iii. Make a circular cut or a serpentine cut on the surface of the pipe, and form a ring-shaped, serpentine-shaped or spiral-shaped cut groove 4 on the outer surface of the pipe (see Figure 3 ).

[0116] The cutting method and depth need to ensure that the pipe wall is not damaged and bone cement leakage will not occur.

[0117] c) Insert a shape memory alloy guide pin 5 into the hollow tube:

[0118] There are two purposes for inserting the shape memory alloy guide pin. One is that when bending in the vertebra, the shape memory alloy bends into a spiral shape to guide the shaping of the biocompatible polymer hollow tube; the other is to discharge most of the air in the hollow tube to reduce thrombus formation; the third is to maintain a good bone cement injection channel to prevent the biocompatible polymer hollow tube from squeezing the injection channel when bending.

[0119] d.) Perform thermal pre-shaping on the biocompatible polymer hollow tube inserted with the needle core:

[0120] i. On the premise that the surface tension of the biocompatible polymer hollow tube is reduced by annular / snake-shaped cutting and inner holes, the biocompatible polymer hollow tube is pre-bent into a spiral structure (as shown in Figure 4 , Figure 5 , hereinafter referred to as the spiral tube) by a heat setting method; the outer diameter of the spiral tube 1A is adjustable and can be prefabricated into different specifications according to needs;

[0121] ii. The spiral tube after thermoforming is a disc-shaped structure, and the spiral tube after thermoforming must be in the elastic region of the material to ensure complete rebound after being straightened.

[0122] Actual operation implementation process:

[0123] a) Injection of PEEK spiral into the vertebral body:

[0124] i. Load the "whole disc" spiral tube 1A into the injectable spiral tube magazine 14 of the injection gun (i.e., the former pushing drive device 7), and load the closed starting end into the gun chamber (see Figure 6 , Figure 7 ).

[0125] ii. Connect the gun chamber of the injection gun to the puncture sleeve 6. The inner diameter of the puncture sleeve is tolerance-matched with the outer diameter of the spiral tube (i.e., the aforementioned biocompatible polymer hollow tube); then insert the shape memory alloy guide needle into the biocompatible polymer hollow tube from the "muzzle" to form a biocompatible polymer hollow tube with a "needle core".

[0126] iii. Through the drive of the injection gun, the spiral biocompatible polymer hollow tube and the shape memory alloy guide needle can be slowly injected (or pushed) into the vertebral body synchronously and integrally.

[0127] iv. The PEEK tube after thermal pre-setting, because it is in the elastic region of the material, is only temporarily forced to be straightened when passing through the puncture sleeve of the injection needle; once the pre-set PEEK tube passes through the puncture sleeve of the injection needle, under the guidance of the shape memory alloy guide needle, it quickly rebounds to its original curvature through internal stress and remains consistent with the previously pre-set shape (i.e., spiral tube shape).

[0128] b) Injection of bone cement:

[0129] i. After the injection of the PEEK spiral tube (also known as the injectable spiral tube) is completed, the injection gun replaces the "magazine" for loading the object to be injected and loads the mixed injectable bone cement.

[0130] ii. Within the curing allowable time of the injectable bone cement, a certain amount of bone cement (which can be calculated in advance according to the size and dimensions of the prefabricated spiral tube) is injected into the PEEK tube by operating or controlling the injection gun.

[0131] iii. The amount of bone cement needs to be carefully measured, including the volume inside the hollow tube and the hollow area inside the space enclosed by the spiral tube. Ensure that the bone cement can fill all the predetermined areas.

[0132] c) Injection gun structure (see Figure 6 , Figure 7 shown):

[0133] i. After the driving handle 10 is pressed, it drives the driving shaft 11, which is transmitted through the belt 12 to transfer the power to the two lower driving rollers 13A (connected by a belt).

[0134] ii. The two upper rollers 13B are driven rollers and do not directly provide power.

[0135] iii. The distance between the upper and lower rollers is adjustable and is consistent with the outer diameter of the spiral tube. The detachable spiral tube is temporarily straightened and then squeezed into the puncture sleeve.

[0136] iv. The injectable spiral tube magazine 14 is a detachable structure and can be loaded with spiral tubes of different specifications according to needs. Similar to the "magazine" structure of a firearm, it will not be elaborated here.

[0137] It should be noted that the pushing and driving device in the technical solution of the present invention is not limited to Figure 6 , Figure 7 the pistol-like structure shown; those skilled in the art can, after understanding and mastering the idea of solving problems of the present invention, completely adopt other similar devices with pushing and injection functions to realize the pushing of the PEEK spiral tube and the injection of bone cement, which will not be elaborated here.

[0138] For the implementation diagram of the injection / pushing step, see Figures 8 to 15 shown.

[0139] Step 1: The biocompatible polymer hollow tube 1 and the shape memory alloy guiding needle 5 are synchronously injected / pushed;

[0140] Figure 8 shows that the hollow tube 1 after being injected / pushed out of the puncture sleeve forms a spiral (coiled tube) structure in the vertebral body 0 under the guidance and action of the shape memory alloy guiding needle 5.

[0141] Figure 9 focuses on showing the shape of the shape memory alloy guiding needle 5 in the hollow tube and its guiding effect on the shaping of the biocompatible polymer hollow tube.

[0142] Step 2: Under the guidance of the shape memory alloy needle, the injection / pushing of the biocompatible polymer hollow tube is completed;

[0143] Figure 10 focuses on showing the hollow tube that has formed the spiral tube 1A in the vertebral body 0.

[0144] Figure 11 The shape of the shape memory alloy guiding needle and its guiding effect on the forming of the biocompatible polymer hollow tube are highlighted. To highlight the shape of the shape memory alloy guiding needle, the biocompatible polymer hollow tube itself is de-emphasized.

[0145] Step 3: Withdraw the shape memory alloy needle from the biocompatible polymer hollow tube;

[0146] Figure 12 It is highlighted that the shape memory alloy needle 5 is withdrawn from the biocompatible polymer hollow tube 1 in the direction shown by the arrow in the figure, so that only the hollow spiral tube 1A with a spiral structure formed in the vertebral body remains in the vertebral body 0. The spiral tube constitutes the boundary of the filling space for the injectable bone substitute or acts as the boundary fence for the filling space.

[0147] Step 4: Inject bone cement into the biocompatible polymer hollow tube.

[0148] Figure 13 It is highlighted that the spiral tube 1A with a hollow and spiral structure formed in the vertebral body remains in the vertebral body, and the injectable bone substitute 8 injected through the biocompatible polymer hollow tube 1.

[0149] At this time, the injectable bone substitute only enters and fills part of the inner space of the spiral tube, and the inner space of the remaining spiral tube is still in an unfilled state.

[0150] Figure 14 It is highlighted that the injectable bone substitute 8 has completely filled the spiral hollow tube and has not overflowed from the inner hole of the hollow tube.

[0151] Figure 15 It is highlighted that the injectable bone substitute 8 has completely filled the inner space of the hollow tube 1 and has overflowed from the inner hole.

[0152] At this time, the injectable bone substitute forms a three-dimensional filling body at the designated position in the vertebral body. When the injectable bone substitute solidifies, it can form a load-bearing bone substitute 9 with the same or similar strength as the vertebral body at the location.

[0153] Obviously, the aforementioned spiral hollow tube constitutes the injection channel for the injectable bone substitute and the boundary or boundary fence of the filling space for the injectable bone substitute.

[0154] In the above figures, when the biocompatible polymer hollow tube is labeled as 1, the emphasis is on its being a hollow tubular structure. When the helical biocompatible polymer hollow tube is labeled as 1A, the emphasis is on its being a helical coiled tube structure. To highlight the hollow property of the helical tube, there are also cases where the helical tube part is labeled as 1.

[0155] After the operations of the above steps, the technical solution of the present invention adopts an integrated injection implementation method. By pushing / injecting the biocompatible polymer hollow tube with a shape memory alloy guide needle acting as a "needle core" to a specified position within the vertebral body, it forms the boundary of the space for the injectable bone substitute or acts as the boundary fence for the filling space, thereby realizing the moldability and controllability of the injectable bone substitute, eliminating the leakage risk of the injectable bone substitute, and further integrating multiple steps such as puncture, distraction, injection of bone substitute, molding, and curing of the injectable bone substitute during vertebroplasty; thus optimizing the operation process, shortening the operation time, and reducing the operation difficulty.

[0156] Example 2:

[0157] Basic idea for solving the problem:

[0158] Combining the basic principles of a tunnel shield machine / tunnel boring machine and a flexible shaft drill, continuously excavate a helical tunnel within the vertebral body; then withdraw the drill bit from the flexible shaft tube, while leaving the degradable part of the flexible shaft tube in the tunnel, and finally inject bone cement into the degradable flexible shaft tube to complete the bone cement shield of the helical tunnel.

[0159] Specifically, the implementation process is as follows:

[0160] 1) Flexible shield system guided by a shape memory alloy guide needle (also known as a guide wire):

[0161] a. This system is jointly composed of a head drill bit 20 (as shown in Figure 16 ), a middle flexible shaft tube, and a tail drive device (not shown in the figure).

[0162] b. The flexible shaft tube part is divided into four layers in total: the outer layer is a degradable tube 21, the middle layer is a wear-resistant tube 22, the inner layer is a flexible rotating shaft 23 for driving the drill bit to rotate, and a hollow central axis layer 24 inside the rotating shaft (as shown in Figures 17 to 18 ).

[0163] c. The gap between the outer layer and the middle layer of the flexible shaft tube can form an annular tube 25, providing an output channel for the bone debris drilled by the drill bit (as shown in Figure 18 , Figure 19 ).

[0164] d. The function of the guide wire (i.e., the aforementioned shape memory alloy guide pin 5) is to guide the drill bit to travel along a predetermined route, such as spiraling up or down, or any other arbitrary path.

[0165] 2) Shield implementation process:

[0166] a. Flexible shield system:

[0167] i. The drill bit 20 is integrally connected to the flexible rotating shaft 23, and the drill bit is exposed outside the degradable tube 21 for drilling and tunneling in the vertebral bone. The flexible shaft tube is formed by being wrapped layer by layer with the aforementioned four-layer tubular structure.

[0168] ii. Outer layer tube: It is a degradable polymer tube. After the bone tunnel tunneling is completed, it remains in the vertebral body, and then bone cement is injected into it.

[0169] iii. Middle layer tube: It is a wear-resistant tube. Its outer diameter is equal to the inner diameter of the outer layer tube and is closely attached to the outer layer tube. It prevents the rotating shaft from wearing the outer degradable tube during the drilling process. After the bone tunnel tunneling is completed, it is pulled out together with the inner driving shaft, guide wire, and puncture needle.

[0170] iv. Inner layer tube: It is the flexible rotating shaft 23 for driving the drill bit to rotate. Its diameter is about half of that of the middle layer tube, and a hollow annular pipe 25 is formed between the two for discharging bone debris. After the bone tunnel tunneling is completed, it is pulled out together with the flexible rotating shaft for inner layer driving, guide wire, and puncture sleeve.

[0171] v. Axial layer: It is a hollow structure inside the flexible driving shaft, and its size allows the puncture needle or guide wire to pass through freely.

[0172] b. With the assistance of X-ray, using the method in Example 1, the puncture sleeve 6 and the puncture needle 6A therein are pushed through the skin to reach the injection starting point (see Figure 20 as shown).

[0173] c. After the puncture needle is withdrawn from the puncture sleeve, a guide wire is inserted. The flexible shield system passes through the hollow tube of its axial layer, penetrates into the puncture sleeve, and reaches the injection starting point of the pedicle (see Figure 21 as shown).

[0174] The drive motor of the flexible rotating shaft (not shown in the figure) is turned on. The flexible shaft tube is guided by the guide wire 5 and simultaneously implements bone tunnel tunneling (see Figure 22 as shown); the bone debris discharged by the shield is discharged through the annular pipe between the middle and inner layers.

[0175] The situation after the bone tunnel tunneling is completed can be seen in Figure 23 as shown.

[0176] d. After tunnel excavation is completed, the outer layer of the flexible shaft tube (degradable tube) is retained in the vertebral body, and the guide wire, the drill bit and the connected rotating shaft, and the middle layer wear-resistant tube in the flexible shaft tube are pulled out in sequence.

[0177] e. After unloading the driving device (motor) at the tail of the flexible shaft tube, install the injectable bone substitute injection gun to the tail of the outer degradable tube; the injectable bone substitute includes but is not limited to bone cement and PMMA (polymethylmethacrylate).

[0178] f. Inject the injectable bone substitute 8 into the degradable tube until the injectable bone substitute fills the entire degradable tube 21, and the bone tunnel is completely filled with the injectable bone substitute (such as bone cement, etc.) (see Figure 24 ).

[0179] g. Complete the vertebral body bone cement shield (bone tunneling) structure (bone cement filling). When the injectable bone substitute is solidified, the remaining structure in the vertebral body is the outer layer (degradable tube) and the bone substitute inside it.

[0180] As shown above. In the technical solution of the present invention, there are two implementation devices as follows:

[0181] 1) For osteoporosis or severe bone loss of vertebral cancellous bone, and when the mechanical bearing requirements are high, there is no need to drill a bone tunnel after distraction.

[0182] At this time, the bone cement reinforced spiral tube double injection system given in Example 1 can be used. This solution uses a larger amount of bone cement to assist in the reinforcement of the peek material outer tube, which can form a stronger vertebral reinforcement and load-bearing effect.

[0183] 2) When osteoporosis or bone loss and destruction of the vertebral cancellous bone is acceptable and the mechanical bearing requirements are acceptable, this technical solution requires drilling a bone tunnel in the target vertebra after spreading two adjacent vertebrae apart.

[0184] At this time, the flexible bone cement shield system guided by the guide wire in Example 2 can be used. This solution integrates the excavation of the bone tunnel and the injection of bone cement through convenient operation.

[0185] The beneficial effects of the technical solution of the present invention are as follows:

[0186] 1) Minimally invasive percutaneous injection / push-in:

[0187] Whether it is the spiral tube double injection system reinforced with bone cement or the flexible bone cement shield system guided by a guide wire, both can be completed through percutaneous minimally invasive injection.

[0188] 2) Molding can be planned:

[0189] In the above two methods, the structure, shape, and size of the injection area can be customized preoperatively according to imaging findings, and can be perfectly formed according to the predefined spatial shape during the operation, which is consistent with the in vitro plan.

[0190] 3) Controllable shaping:

[0191] a) Controllable implantation position: According to the degree of vertebral body compression damage, the damaged area is evaluated; the area to be expanded (the relatively intact area of the upper and lower cortical bones) is accurately positioned without affecting the remaining areas.

[0192] b) Controllable injection volume: The implantation is limited to a specific area. The injection volume of the bone cement required can be accurately calculated; various complications caused by bone cement leakage and the uncontrollable mechanical support effect are perfectly solved.

[0193] c) Controllable expansion (shaping) effect: According to the damage conditions of the adjacent segment intervertebral discs and endplates, a reduction plan is formulated preoperatively; by selecting the most suitable peek screw body model, the expected expansion / reduction effect can be accurately achieved.

[0194] d) Controllable mechanical support: The injected peek screw body has a closed structure. Through the void reserved for the bone cement inside, the dosage and diffusion path of the bone cement can be strictly restricted, and the composite support system of the two can achieve the same mechanical strength as the in vitro simulation.

[0195] 4) Flexible implementation methods can be selected:

[0196] a) The double-injection system of the bone cement-reinforced spiral tube can be used for vertebroplasty that requires stronger mechanical support.

[0197] b) The flexible bone cement shield system guided by a guide wire can be used for vertebroplasty that requires more convenient and integrated operation.

[0198] The technical solution of the present invention is to push / inject a degradable hollow tube with a shape memory alloy guide needle acting as the "needle core" to a specified position in the vertebral body, forming the boundary of the bone cement filling space or acting as the boundary fence of the filling space; at the specified position in the vertebral body, a bone substitute can be injected to fill the biocompatible polymer hollow tube and the filling space surrounded by it. It makes the bone cement injection area programmable and integrates multiple operations such as puncture, expansion, injection of implants and bone cement, and shaping in vertebroplasty.

[0199] The present invention can be widely used in the design and manufacturing fields of orthopedic implant injection devices.

Claims

1. An integrated injection device for an injectable bone substitute in vertebroplasty, characterized in that: The integrated injection device at least includes a pushing drive device, a biocompatible polymer hollow tube, and a linear shape memory alloy guide needle; The pushing drive device has a straight tubular puncture sleeve. Under the action of the puncture sleeve, the biocompatible polymer hollow tube and the linear shape memory alloy guide needle are forced to be pushed into the vertebra synchronously in a linear structural form; In the biocompatible polymer hollow tube, a shape memory alloy guide needle is arranged, and the shape memory alloy guide needle constitutes the "needle core" of the biocompatible polymer hollow tube, making the two into an integrated structure; The front end of the biocompatible polymer hollow tube is hermetically arranged; Among them, the pushing drive device is used to push the biocompatible polymer hollow tube and the shape memory alloy guide needle to a specified position inside the vertebra; The shape memory alloy guide needle is used to guide the bending of the biocompatible polymer hollow tube, discharge most of the air in the hollow tube, and can prevent the biocompatible polymer hollow tube from squeezing the injection channel when bending, maintaining a good injection channel for the injectable bone substitute; The biocompatible polymer hollow tube constitutes the boundary or boundary fence of the injection channel of the injectable bone substitute and the filling space of the injectable bone substitute; For the integrated injection device, a linear shape memory alloy guide needle is inserted into the biocompatible polymer hollow tube, and thermal pre-forming is carried out. The two are integrally and synchronously pushed into the vertebra. Under the guidance of the shape memory alloy guide needle, the biocompatible polymer hollow tube quickly rebounds to its original curvature through internal stress, and then constitutes the boundary of the filling space of the injectable bone substitute or serves as the boundary fence of the filling space; then the injectable bone substitute is injected through the hollow tube to the specified position; furthermore, at the specified part in the vertebra, the injectable bone substitute fills the biocompatible polymer hollow tube and the filling space surrounded by it; enabling the injectable bone substitute injection area to have plannability, and integrating multiple operations such as puncture, distraction, injection of implants and bone cement, and shaping in vertebroplasty; all steps are carried out synchronously, optimizing the operation process, shortening the operation time, and reducing the operation difficulty.

2. The integrated injection device of the injectable bone substitute according to claim 1 in vertebroplasty, characterized in that After thermal pre-forming, the biocompatible polymer hollow tube and the shape memory alloy guide needle are pre-formed and then placed into the pushing drive device; Insert the puncture sleeve of the pushing drive device to the specified position inside the required vertebra; The pushing drive device, with the help of the puncture sleeve, continuously and synchronously sends out the pre-formed biocompatible polymer hollow tube and the shape memory alloy guide needle integrally; Under the forced restraint and guidance of the straight tubular puncture sleeve, the pre-formed biocompatible polymer hollow tube and the shape memory alloy guide needle are sent to the specified position inside the vertebra in a straight line; After leaving the straight tubular puncture sleeve, the biocompatible polymer hollow tube quickly rebounds to its original curvature through internal stress under the guidance of the shape memory alloy guide needle, restoring or maintaining the same shape as after thermal pre-forming; The integrated injection device described above continuously and synchronously pushes the biocompatible polymer hollow tube and the shape memory alloy guide needle, thereby forming an injectable bone substitute filling space in the vertebral body that is the same as or similar to the shape of the biocompatible polymer hollow tube after thermal pre - shaping.

3. The integrated injection device for injectable bone substitute in vertebral body forming according to claim 1, characterized in that a plurality of side holes are provided on one side of the biocompatible polymer hollow tube; When the biocompatible polymer hollow tube is thermally pre - shaped, the side holes face the inside of the filling space surrounded by the biocompatible polymer hollow tube; Through pushing or injection, the injectable bone substitute fills the internal space of the biocompatible polymer hollow tube; Alternatively, through pushing or injection, the injectable bone substitute passes through the biocompatible polymer hollow tube with a multi - side - hole structure and fills the biocompatible polymer hollow tube and the three - dimensional filling space surrounded by it.

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