The present invention relates to an implant fusion device and a method of manufacturing an implant fusion device. More particularly an orthopedic or dental implant or fastener configured to be implanted between adjacent vertebrae or within a gap in a bone or between bones, the device having improved osteoinductive features on exterior surfaces wherein the device is fabricated using 3D printing. This invention may be applicable to any implant device that contacts or interacts with bone.
Surgical implantation of interbody cages is typically used to provide support along the spinal column in cases where a portion of the patient's intervertebral anatomy has become weakened, diseased, or destroyed. Such support systems are also commonly used following a discectomy, where an intervertebral disc is surgically removed.
Most commonly, existing support systems typically operate by inhibiting normal movement between the adjacent vertebrae, thereby stabilizing these vertebrae at fixed positions relative to one another, with the mechanical body of the supporting structure providing the needed support along the patient's spinal column. Such supporting systems are typically made of stainless steel, titanium, titanium alloy, polymer (e.g., an organic polymer thermoplastic such as polyether ether ketone (PEEK)), carbon fiber, or ceramic and they are designed to permanently remain within the patient's body.
It is beneficial, in addition to fixation, to try to stimulate bone growth between the adjacent vertebrae. To do so, spine surgeons often use bone graft material in addition to fixation devices. Bone graft doesn't heal or fuse the spine immediately; instead, bone graft provides a foundation or scaffold for the patient's body to grow new bone. Bone graft can stimulate new bone production. When new bone grows and solidifies, fusion occurs. Although instrumentation (e.g., screws, rods) is often used for initial stabilization (post-operative), it is the healing of bone that welds vertebrae together to create long-term stability. There are two general types of bone grafts: real bone and bone graft substitutes. Real bone can come from the patient (autograft) or from a donor bone (allograft). Also used in these types of surgery are bone substitute, osteoinductive agents, stem cell products, bone morphogenic proteins, and bone cement.
There is a need for improved systems and methods for spinal fusion devices and other implant devices that interact with bone. Ideally, the spinal fusion implant device has features that facilitate new bone growth to achieve fusion of the adjacent vertebrae.
As used herein and in the claims:
3D printing, or additive manufacturing, is the construction of a three-dimensional object from a CAD model or a digital 3D model. The term “3D printing” can refer to a variety of processes in which material is deposited, joined or solidified under computer control to create a three-dimensional object, with material being added together, typically layer by layer.
Laser modifications can include laser etching, engraving, or any other use of a laser to change or treat a surface of an implant device or any other surface.
Nanotechnology is the engineering of functional systems at the nanometer scale. This covers both current work and concepts that are more advanced. In its original sense, nanotechnology refers to the projected ability to construct items from the bottom up, using techniques and tools being developed today to make complete, high-performance products. Alternatively, nanostructure may be developed through subtractive processes.
Cortical or compact bone can be distinguished macroscopically from cancellous or trabecular bone. Cortical bone is a dense tissue that contains less than 10% soft tissue. Cancellous or spongy bone is made up of trabeculae, shaped as interconnected plates or rods and arced structures interspersed between voids in the mineral structure that contain blood cells in the marrow space which represents more than 75% of the cancellous bone volume.
Microtechnology/Laser Micro Machining: Although similar in concept to traditional machining operations, laser micro machining (laser micromachining) is capable of creating extremely small features—generally under 1 mm, and in some cases only a few microns in size—with a high degree of repeatability and without causing significant structural damage to the surrounding material.
Micron (μm) Microns, also known as micrometers (represented as μm) are a length of measurement equal to one millionth of a meter. (1,000 μm is equal to 1 mm.)
Nanotechnology: One nanometer (nm) is one billionth, or 10-9, of a meter. By comparison, typical carbon-carbon bond lengths, or the spacing between these atoms in a molecule, are in the range 0.12-0.15 nm, and a DNA double-helix has a diameter around 2 nm. On the other hand, the smallest cellular life-forms, the bacteria of the genus Mycoplasma, are around 200 nm in length. By convention, nanotechnology is taken as the scale range 1 to 100 nm following the definition used by the National Nanotechnology Initiative in the US. The lower limit is set by the size of atoms (hydrogen has the smallest atoms, which are approximately a quarter of a nm kinetic diameter) since nanotechnology must build its devices from atoms and molecules. The upper limit is more or less arbitrary but is around the size below which the phenomena not observed in larger structures start to become apparent and can be made use of in the nano device. These new phenomena make nanotechnology distinct from devices which are merely miniaturized versions of an equivalent macroscopic device; such devices are on a larger scale and come under the description of microtechnology.
Trabecular bone is a highly porous (typically 75-95%) form of bone tissue that is organized into a network of interconnected rods and plates and arcs called trabeculae which surround pores that are filled with cellular bone marrow.
The present invention according to a first embodiment is a method of making a spinal implant fusion device having the steps of: fabricating an implant body structure using 3D printing to create the implant body structure; additively building the body structure having a superior load bearing surface and an inferior load bearing surface and a wall structure; and wherein the body structure has at least a portion of the body structure having a plurality of interconnected struts forming porous walls with openings or passages extending inwardly from an exterior surface to a depth of 1.0 mm or greater forming a porous portion with a void volume to solid mass volume mimicking trabecular bone. Alternatively, the 3D printed structure may be completely or substantially solid with a surface structure comprised of the interconnected arcs that are raised, or created like troughs that appear to be cut into the surface but were created through 3D printing.
The average or nominal ratio of void volume to mass volume in the porous portion is in the range of 65 percent or more, preferably 75 percent replicating that of trabecular bone in an adult male. The struts of the porous walls are curved or arch shaped with openings communicating with adjacent walls. The porous portion of the implant body structure extends at least partially across the implant body structure exterior surfaces forming conduits for fluid passage throughout the device. The curved or arch shaped struts of the walls create a load bearing capacity to withstand vertical loads without collapsing. The implant fusion device has the superior load bearing surface and the inferior load bearing surface having nano nanometer-scale features resulting from laser etching. In addition to load bearing surfaces, other surfaces of an implant may be laser etched as well. The etching created through a subtractive laser process. Alternatively, the 3D printed structure may be solid or relatively solid with a 3D printed surface structure that mimics trabecular bone structure as described above, with a laser etched subtractive process then applied that results in a nanotechnology level of surface which is biologically active for the induction of bone formation and growth.
In a second embodiment, a method of making a spinal implant fusion device has the steps of: providing a 3D printed implant body structure; and subsequent subtractive laser etching which results in nanometer-level structure on at least a portion of a surface or surfaces of the implant body structure, the nanometer structure creating new bone growth attachment features to enhance osteoinductivity of the spinal implant or orthopedic fusion device.
The laser etched nanometer structural features are made into a network of features in either a random pattern or an organized pattern. The laser etching is formed by emitting laser beams unobstructed to the surfaces of the implant. The method of making a spinal implant fusion device or other orthopedic or bone implant further has the step of moving a laser about the implant body structure to create the network of features or the method has the step of moving the implant body structure about a laser to create the network of features.
The present invention also has the combination of 3D printing and laser etching in a method of making a spinal implant fusion device or orthopedic or bone device having the steps of: fabricating an implant body structure using 3D printing to create the implant body structure; additively building the body structure having a superior load bearing surface and an inferior load bearing surface and a wall structure; wherein the body structure has at least a portion of the body structure having a plurality of interconnected struts forming porous walls with openings extending inwardly from an exterior surface to a depth of 1.0 mm or greater forming a porous portion with a void volume to solid mass volume mimicking trabecular bone; and laser etching nano channels on at least a portion of the exterior surface or surfaces of the implant body structure, the nano channels creating new bone growth attachment features to enhance osteoinductivity of the spinal implant fusion device.
The method of making a spinal implant device or orthopedic device or bone implant device wherein the structure is produced through a 3D printing additive process, which is then further processed with a laser etching technology that results in a nanotechnology structure at the surface that facilitates bone attachment and growth. The 3D printing additive process creates a structure at the implant surface that mimics trabecular bone structure.
The spinal implant device or orthopedic device or bone implant device can be produced through a 3D printing additive process in a biocompatible material or materials that is further processed through a subtractive laser etching process that results in a surface or surfaces with nanometer-level structural elements. The 3D printing additive process results in surface features that mimic trabecular bone structure.
The invention will be described by way of example and with reference to the accompanying drawings in which:
With reference to
As shown in
As shown, the exemplary embodiment is merely example of configurations that can be employed to make the present invention. Any number of shapes can be used in this configuration and can be any number of polygonal shapes of various shapes and sizes as long as they are sufficient to support the load between the adjacent vertebral bodies to make a proper implant fusion device.
For example, the cube shape in
With reference to
Optionally, this porous structure of interconnected struts 26 can be made to extend throughout the implant body structure if so desired. In practice, it has been found that the depth of the surfaces mimicking the trabecular bone of at least 1 mm in depth is ideal for new bone formation and therefore the 3D manufacturing of the implant can be made simpler and less expensively by limiting the depth to 1 mm or greater. Additionally, the superior 14 and inferior 16 surface should have the porous trabecular features, but the side walls could be solid as an optional way to manufacture the implant.
With reference to
In
With reference to
Laser modifications can be made using the exemplary methods and settings described herein. The laser modifications can be made on the unthreaded, threaded or both portions of the screw. Different treatment areas or options can be 4 of 8 surfaces or 6 of 12 surfaces as shown in
The method of making a spinal implant device or orthopedic device or bone implant device according to the present invention made by 3D printing and a post process with a laser etching process resulting in nanometer scale of surface structure that is biologically active in inducing bone growth. In addition, a 3D printing orthopedic or spinal device in which a surface pattern mimicking trabecular bone with arching structure mimicking trabecular bone formation that is created through the 3D printing process that either appears raised from the surface or recessed into the surface, either way it is made through the additive manufacturing process. Further, laser etched surface results in a nanometer scale structure that is active in bone growth formation. The laser etching results in a nanometer scale surface structure because the heat of the laser does not cause a significant melt at the surface that would remove material from the ablation from the nanometer scale of the structure rather than the laser heating it up so that it sears the surface through melting.
These and other aspects of the present invention are believed to greatly enhance the ability of the present device made by 3D printing and laser etching to provide an improved implant fusion device.
Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims.
The present invention is a continuation in part of co-pending U.S. application Ser. No. 18/339,577 entitled “Implant Fusion Device And Method Of Manufacturing” filed on Feb. 28, 2020.
Number | Date | Country | |
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63354748 | Jun 2022 | US |
Number | Date | Country | |
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Parent | 18339577 | Jun 2023 | US |
Child | 18488575 | US |