Dynamic implant fixation plate

Abstract

To provide a fixation plate capable of reducing origination of stress shielding and enabling an increase in load in an implant site, and an implant corresponding to the fixation plate.SOLUTION: A dynamic implant fixation plate 10 and an implant 20 configured to accept the disclosed fixation plate 10 can provide means that fixes the implant 20 with respect to one or more planes and enables movement relative to one or more planes, in some aspects.SELECTED DRAWING: Figure 2

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application was filed on July 2, 2018, which is incorporated herein by reference in its entirety. This application claims the benefit of U.S. Provisional Application No. 62 / 703,562, filed on the 6th. [Technical field]

[0002] The present invention relates to medical implants, and more particularly to a method for providing a medical implant using a fixation plate. Regarding. [Background technology]

[0003] Medical implants can be placed in a fixed location within the body by a variety of means. For example, a bone fusion implant may be secured to a patient's bone using a bone screw. Summary of the Invention [Means for solving the problem]

[0004] Disclosed herein is a dynamic implant fixation plate (hereinafter referred to as the "fixation plate"). In some embodiments, the fixation plate is attached to the implant after implantation. In some embodiments, the plate may be movable relative to the plate. The base may rotate or move relative to the implant and / or the patient tissue after implantation. In some embodiments, the fixation plate can be moved after implantation. As used herein, a graft may be used to provide axial compression to the graft. The term "tissue" includes, but is not limited to, muscle tissue, epithelial tissue, connective tissue, nerve tissue, It refers to any type of biological, natural or synthetic tissue, including bone tissue and bone structures.

[0005] In the embodiment of the fixation plate presented herein, the fixation plate is The implant can be attached with at least one degree of freedom. As used in this specification, the term "degree of freedom" means a small degree of movement. In addition, the fixation plate is attached to the first bone and / or or a second bone, each attachment having at least one degree of freedom. In some embodiments, the fixture plate has one or more degrees of freedom relative to the attachment point. and attaching it to the implant and / or tissue. The fixation plate may be attached to the first bone and / or the second bone with a conical degree of freedom. can be done.

[0006] Some embodiments of the fixation plate have screw holes with a concave profile and screw heads. A thread having a convex profile that corresponds to the concave profile of the screw hole, as viewed from the end facing the threads. The bone is attached to the patient's bone using a bone screw with a convex screw head and a concave The use of a screw hole having a conical profile can provide fixation with at least a conical degree of freedom. The bone screw head fits into the screw hole of the fixation plate with a clearance fit greater than zero. The clearance fit may be such that in some embodiments the clearance fit allows for a certain amount of translational movement. and prevents binding between the bone screw head and the screw hole of the fixation plate. It is possible.

[0007] The fixation plate is attached to the implant using a fastening means with at least one degree of freedom. Some embodiments of the fixation plate may be provided with a certain amount of and the fixation plate, implant and / or fastening means A fastening means having a clearance fit greater than zero that can prevent contact between the Some fastening means that can be used include, but are not limited to, quarter turn fastenings. There are fasteners, screws, etc.

[0008] The fixation plate is a bone fusion implant that fixes the implant to one or more bone structures. The actuator can be configured for use in a vehicle with at least one degree of freedom. When using a car for installation, the fixation plate is attached so that the axis of the implant is aligned with the first bone. does not significantly impede axial compression of the implant in a direction between the first bone and the second bone. Some embodiments have at least a conical free end that allows for more than purely axial loading. Use degrees.

[0009] The fixation plate disclosed herein is desired to avoid stress shielding for the implant. It can be used in situations where there is a need for a rigid attachment between the implant and the patient's bone. This allows new bone growth and shields existing bone from stress, resulting in increased bone growth. The fixation plates disclosed herein are designed to reduce the load on the bone and can weaken the bone and potentially cause bone loss. The implant does not support the load, but transfers it to the implant, and the elasticity and footprint of the implant are compensated for. Determine the amount of axial compression that can be tolerated at the site of compression.

[0010] Despite allowing axial movement, the fixation plate disclosed in the present invention does not allow lateral or The implant provides adequate axial stability for new bone growth. When using implants that provide stability, it is important to ensure adequate stability in non-axial directions. This can result in new bone growth. [Brief description of the drawings]

[0011] [Figure 1A] FIG. 1 is an isometric perspective view of a single modified rhombic dodecahedral unit cell containing a fully modified rhombic dodecahedral structure along with radial struts with portions of adjacent unit cells. [Figure 1B] FIG. 1 is a side view of a single modified rhombic dodecahedral unit cell showing the interconnection topology when viewed from the side. [Figure 1C] FIG. 13 is a side view of a single modified rhombic dodecahedral unit cell measuring its central void using the longest dimension measurement method. [Figure 1D] FIG. 13 is a side view of a single modified rhombic dodecahedral unit cell with interconnects being measured using the longest dimension metrology method. [Figure 1E] FIG. 13 is a side view of the central void of a modified rhombic dodecahedral unit cell being measured using the longest sphere measurement method. [Figure 1F] FIG. 13 is a cross-sectional view of an interconnect being measured using the longest sphere measurement method. [Figure 1G] FIG. 1 is an isometric view of a single radial dodecahedral rhombic unit cell. [Figure 1H] FIG. 1 is a side view of a single radial dodecahedral rhombic unit cell. [Figure 1I] FIG. 13 is an isometric view of an example of a single node and single strut combination that can be used in a radial dodecahedral rhombus unit cell. [Figure 1J] FIG. 13 is a side view of an example of a single node and single strut combination that can be used in a radial dodecahedral rhombus unit cell. [Figure 1K] FIG. 13 is a side view of a corner of a volume defining the combination boundary of a single node and single strut combination configured for use in a lattice having an elastic modulus of about 3 GPa. [Figure 1L] FIG. 13 is a side view of a corner of a volume defining the combination boundary of a single node and single strut combination configured for use in a lattice having an elastic modulus of about 4 GPa. [Figure 1M] FIG. 13 is a side view of a corner of a volume defining the combination boundary of a single node and single strut combination configured for use in a lattice having an elastic modulus of about 10 GPa. [Figure 1N] FIG. 13 is a side view of the combination of a single node and two adjacent struts viewed from a corner of the volume defining the combination boundary and lateral separation angle. [Figure 1O] FIG. 1 is an isometric view of a sub-unit cell consisting of a single node and four struts. [Figure 1P] FIG. 1 is an isometric view of a stacked configuration of two sub-unit cells, with the upper sub-unit cell inverted on top of the lower sub-unit cell. [Figure 1Q] FIG. 1 is an isometric view of eight sub-unit cells stacked together to form a single unit cell. [Figure 1R] FIG. 2 is a side view of a bone fixation plate, bone screws and implants. [Diagram 2] FIG. 1 is an isometric view of a bone fixation plate, bone screws and implants. [Diagram 3] FIG. 1 is an isometric view of a bone fixation plate and implant. [Figure 4] FIG. 2 is a side view of a bone fixation plate and implant. [Figure 4A] FIG. 1 is a side view of a bone fixation plate and two bone screws with hidden features shown in dashed lines. [Diagram 5] FIG. 2 is a side cross-sectional view of a bone fixation plate and implant. [Figure 6] FIG. 2 is a rear view of the bone fixation plate and implant. [Figure 7] FIG. 13 is a rear view of the implant receiving the bone fixation plate. [Figure 8] FIG. 2 is a side cross-sectional view of a bone fixation plate and implant. [Figure 9] FIG. 1 illustrates an isometric cross-sectional view of an implant configured to receive a bone fixation plate. [Figure 10] FIG. 13 is a top cross-sectional view of an implant configured to receive a bone fixation plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In many situations, it is desirable to use implants that allow bone attachment or osseointegration over time. Furthermore, in many situations, it is desirable to have the ability to attach or integrate with living tissue. It is preferable to use implants that allow bone attachment or osseointegration. Examples of implants that may be used include, but are not limited to, cervical, lumbar, and thoracic interbody fusion implants. Runt, Vertebral body replacement, Osteotomy wedge, Dental implant, Bone stem, Acetabular cup, Head These include opercular-facial plating, bone replacement and fracture plating. In many applications, Additionally, it is desirable to apply stress to increase the strength of the new bone growth. According to the study, bones adapt to the stresses applied to them, and as a result bones grow stronger under stress. Longer and less stressed bones become weaker.

[0013] In some aspects, the systems and methods described herein provide for bone integration and proper stressing. Implants configured for imparted new bone growth stimulation can be envisioned. Many of the exemplary implants of the invention are particularly well suited for providing strong bone attachment throughout the implant body. and / or bone growth. Whether the invention is desirable only for the implant or throughout the entire implant, Ming has developed a unique lattice structure that allows mechanical spacing, a scaffold that supports new bone growth, and the elastic modulus at which new bone growth can be loaded with physiological forces. Therefore, the present invention provides a method for providing a more reliable attachment and / or stronger bone structure after implant osseointegration. This provides implants that grow stronger and healthier bones for new bones.

[0014] The exemplary embodiments of the invention presented herein may comprise, in whole or in part, a grating. As used herein, a grid may be defined as a grid having one or more interconnected apertures. refers to a three-dimensional material that allows fluid communication from one location to another through openings. By original material is meant a material that fills a three dimensional space (i.e., has height, width and length). A lattice is a set of interconnected structures that contain a variety of repeating geometric shapes or repeating random shapes. This can be accomplished by many means of constructing a material with openings. An opening is any area within the boundary of a three-dimensional material that is free of material. Within the dimensional boundary there is a volume of material and a volume that is free of that material.

[0015] The material that provides the lattice structure is called the primary material. The lattice structure may be used to provide structural support for any purpose. It does not necessarily mean a structure, but rather a configuration of openings and interconnections that form a grid. The openings in the grid can be empty, filled with a gaseous fluid, filled with a liquid fluid, or filled with a solid. The interconnects to the openings may be filled or partially filled with fluid and / or solid. Interconnects are areas that are free of primary material and connect at least two locations to each other. , can be configured to allow fluid to pass from one location to another.

[0016] Lattice refers to the ratio between the primary material volume and the void volume, which is the percentile for a given three-dimensional material. The void volume can be defined by the volume density expressed as a percentage. The void volume is the difference between the volume of the material boundary and the primary material volume. It may consist of a volume of joints and / or a volume of other materials. For example, 30% A dense lattice is one that, for a given volume, contains 30% by volume of primary material and 70% by volume of voids. A lattice with a 90% volume density is one that is made up of 90% by volume of the primary material. , and 10% by volume of voids. In three-dimensional materials with a volume density of less than 50%, The volume of the primary material is less than the void volume. When bulk density refers to void volume, the void is The implant need not remain in place, but may be fully or partially fluid or can be filled with a solid.

[0017] Lattice structures consisting of repeating geometric patterns can be described using the properties of the repeating unit cells. A unit cell in a repeating geometric lattice is a three-dimensional shape that can be repeated to form the lattice. The repeating unit cells are arranged in a lattice structure or pattern over all or a portion of the lattice structure. Each unit cell can refer to a number of identical unit cells repeated in a volume. The spot consists of a certain material and a certain void volume, or in other words, a spot volume density. The volume density can cover as few partial unit cells as possible, or multiple unit cells. In most situations the spot volume density corresponds to the material volume density, but locally the spot volume There are situations where it is desirable to increase or decrease density.

[0018] The unit cells can be configured in many volumetric shapes containing various types of structures. A unit cell is a defined space that limits the size of a lattice structure or other type of structure within the unit cell. In some embodiments, the unit cell can be defined by, but is not limited to, However, they are classified according to volume shape, including cubic volume, rectangular volume, hexahedral volume, and amorphous volume. The volume of the unit cell is defined based on a number of faces that meet at the corners. In embodiments where the volume of the unit cell is a cube, a rectangular solid, or a hexahedron, The volume of a unit cell can have six faces and eight corners, with the corners being three A unit cell is defined as a set of surfaces that are interconnected in some or all areas. Interconnected, non-interconnected in some or all areas, non-interconnected in some or all areas Uniform size in all areas, or uniform size in some or all areas Some of the techniques described herein that use repeating geometric patterns may be used. In some embodiments, the unit cell defines an edge of the unit cell and also has nodes around the unit cell. The unit cell can be defined by a number of struts connected at the ends. The unit cells can share some struts between more than one unit cell, which allows adjacent The two unit cells share a common planar wall defined by struts common to both lattices. Some implementations described herein use repeating geometric patterns. In this embodiment, the unit cell is formed by a node and a number of struts extending radially from the node. It can be defined as follows.

[0019] This application describes exemplary embodiments using volumetric density, but is not limited to lattice size. Other metrics including size, strut size or stiffness may also be used to describe the strut. The size can be defined in a number of ways, including but not limited to strut length and strut diameter. Cut.

[0020] Repeated geometric patterns can provide predictable properties for implants. Many repeating geometric shapes are useful for use in lattice structures, including but not limited to rhombic structures. Shape: Dodecahedron, diamond, dodecahedron, square, pentagon, hexagon, octagon, scutet ( sctet (trunic) struts, truncated (trunic) octagons, diagonal struts, other known geometric structures, and each geometric structure Rounded, reinforced, weakened, or simplified versions of geometric shapes can be used as a unit cell of a lattice containing

[0021] The lattice may be incorporated into the implant as a structural or non-structural component. A lattice used for structural purposes is herein referred to as a structural It may be referred to as a structural lattice, a load-bearing lattice, or a stress-applying lattice. In this context, a structural lattice, a load-bearing lattice or a stress-applying lattice may simply be referred to as a lattice. Repeating geometric unit cells, especially the rhombic dodecahedron, are theoretically capable of being constructed due to their strength-to-weight ratio. Suitable for use in structural grids. Improves the practical strength and fatigue resistance of rhombic dodecahedral grids. To achieve this, the present invention in some embodiments uses posts having rectangular or circular cross sections. Rather than using a conventional spur, the struts include modified struts made of triangular segments. Some embodiments modify the angles that define the rhombic faces of a rhombic dodecahedron to improve the elastic modulus and The use of triangular segments provides a theoretical advantage over the rhombic dodecahedral lattice. This results in a lattice with highly predictable print characteristics that approximate the intensity values ​​of

[0022] In structural lattice applications, the strength and elastic modulus of the lattice can be approximated by the bulk density. When the volume density increases, the strength and elastic modulus increase. Compared to other porous structures The lattice of the present invention is a rhombic dodecahedral lattice, a modified rhombic dodecahedral lattice or a radial dodecahedral lattice. Due to the ability to take advantage of the high strength-to-weight ratio of the rhomboidal unit cell, It has higher strength and modulus of elasticity.

[0023] As used herein, the term "elastic modulus" refers to the elastic modulus of a material or the elastic modulus of a material. The elastic modulus can refer to either the effective modulus of elasticity or the product of the elastic deformation in response to stress. The material volume is determined by the material's elastic modulus and the material's resistance to the force. The effective modulus of elasticity can be determined by compressing the material volume. and by treating it as a homogeneous material for the purposes of calculating the effective modulus. The term "elastic modulus" as used herein refers to the elastic modulus of a material or the effective volume of a material. The term may refer to both the elastic modulus and the thickness of the material.

[0024] When configured to provide support for bone or tissue growth, the lattice may be referred to as a scaffold. The lattice can control the size of the openings and interconnects that are placed within the three-dimensional material. The scaffold can be configured to provide support for bone or tissue growth. When used on the surface of an implant, it provides an osseointegrative surface that allows adjacent bone to attach to the implant. The scaffold also allows bone to grow further than mere surface attachment. The scaffold intended for surface attachment can be configured to provide a pathway through which the In the specification, this is referred to as a superficial scaffold. A superficial scaffold does not extend deep into the implant but does not extend through the entire volume of the implant. The surface attachment may be one or more unit cells that do not extend over the entire surface area. Scaffolds that are intended to support growth beyond the tissue are referred to herein as bulk scaffolds. may also be included in the implant as a structural or non-structural component. Scaffolding used in structural applications is referred to herein as structural scaffolding, load-bearing scaffolding, and They may be called supporting or stress-applying scaffolds. In some cases, they may be called structural, load-bearing, or A supporting or stress-applying scaffold may simply be referred to as a scaffold. The use of "scaffolds" refers to materials that are designed to provide bone or tissue growth support. , it is possible to refer to materials that are not lattices.

[0025] The scaffolds described herein promote the attachment or growth of various types of tissues found in living organisms. As mentioned above, some embodiments of the scaffold can be used to promote bone attachment and The scaffold may further be configured to promote the growth of other areas of tissue, such as a fibrous composition. In some embodiments, the adhesive layer may be configured to promote adhesion or growth on the surface of the adhesive layer. Thus, the scaffold can be configured to promote attachment or growth of multiple types of tissue. Some embodiments of the scaffold are configured to be implanted adjacent to or against living tissue. Near the living tissue means that there are no other layers, materials or coatings between the scaffold and any living tissue. This includes the situation in which the ting is located.

[0026] In some embodiments, the present invention provides larger apertures and reciprocal apertures than previously known. A bulk scaffold with connections is used. Osteon (bone unit) is a straight line from about 100 μm. The researchers theorized that osteon bundles produce the strongest form of new bone growth. A bone is considered to be sufficiently solid when it has a diameter greater than 3 mm; Thus, osteon bundles with diameters roughly equal to half of that value grow larger when grown within the scaffold. It is theorized that this results in greater strength. Osteon growth occurs in irregular shapes, leading to osteon fracture. It is also theorized that area predicts its strength. Cylindrical osteon growths of 3 mm diameter has a cross-sectional area of ​​about 7 square millimeters, and a cylindrical osteon growth with a diameter of 1.5 mm A cross-sectional area of ​​about 1.8 square millimeters. A cross-sectional area of ​​at least 1.8 square millimeters. Irregularly shaped osteons with can be done.

[0027] Many of those skilled in the art would consider a pore size of 300 to 900 μm in diameter or width and a pore side of 600 μm. It has been shown that the ideal pores or openings provide the best scaffold for bone growth. , some embodiments of the present invention are within the known range of 1.0 to 15. 0 times the diameter or width, resulting in a 0.07 mm 2 ~145mm 2 In some embodiments, the openings and interconnects are In the examples, the diameter is between 100 μm and 300 μm, inclusive. Pores or openings having a width may be beneficial. Some examples are in the known range of 1.0 to 5.0. The present invention includes apertures and interconnects having diameters on the order of twice that of previously known apertures and interconnects. The use of large apertures and interconnections allows for the integration of all osteons and solid bone tissue throughout the bulk scaffold. In some embodiments, the implant is adapted to form a vascularized structure for new load-bearing bone growth. These pores are about 3 mm or 7 mm in diameter. 2 In another embodiment, the cross-sectional area of ​​the The pores are 1.5 mm or approximately 1.75 mm in diameter. 2 The cross-sectional area of ​​the conventionally known small diameter Using only the same diameter openings and interconnects allows the smaller diameter openings to be distributed throughout the bulk scaffold. It is theorized that this limits the vascularization capacity of the scaffold, thereby restricting the penetration of new bone growth into the bulk of the scaffold. It is being done.

[0028] A related structure to the lattice is the closed-cell material. A closed-cell material is a three-dimensional material with a boundary between the Although similar to a lattice in that it has openings trapped within it, closed cell materials generally There are no interconnections between locations via openings or other pores. The closed cell structure allows for a number of methods This can be achieved, for example, by using some cell packing or solid walls between the struts of the unit cells. This can be achieved by using a closed cell structure, also known as a cytoplasmic structure. It is possible to have a material that is a lattice in one portion and a closed cell material in another portion. It is possible to have a closed cell material that is a grid with only a few interconnections between the openings. Although this disclosure focuses on lattices, the structures described herein may and the method can be readily adapted for use in closed cell structures within the inventive concept.

[0029] The gratings used in the present invention can be produced from a wide range of materials and processes. When used as a scaffold for bone growth, the lattice can be bonded directly to the material or to a biomaterial. The implant is made of a biocompatible material that can be attached to bone by either an active surface treatment or a biocompatible material. In one embodiment, the scaffold is comprised of an implantable metal. The implantable metal may be , including but not limited to, zirconium, stainless steel (316 and 316L), tantalum, nickel rolls, cobalt, chromium alloys, titanium and tungsten, and their alloys. Implantable metal-composed scaffolds are produced using additive metal fabrication or 3D printing processes. Suitable manufacturing processes include, but are not limited to, direct metal laser sintering, selective Selective laser sintering, selective laser melting, electron beam melting, laminated object manufacturing and fingering There is a positive energy deposition.

[0030] In another embodiment, the grid of the present invention is an implantable metal having a bioactive coating. Bioactive coatings include, but are not limited to, coatings that promote bone growth. coating, antithrombogenic coating, antibacterial coating, hydrophobic or hydrophilic coating, Coatings that promote bone growth include blood-resistant, super-blood-resistant, and blood-philic coatings. Examples include, but are not limited to, calcium phosphate, hydroxyapatite ("HA"), silicates Glass, stem cell derivative, bone morphogenetic protein, titanium plasma spray, titanium beads and titanium mesh. Antithrombogenic coatings include, but are not limited to, low molecular weight fluorosuccinic acid (FBA) and titanium mesh. Antimicrobial coatings include, but are not limited to, silver, organosilanized Superhemophobic coatings include fluorinated nano-titanium. There is a tube.

[0031] In another embodiment, the lattice is made from a titanium alloy with an optional bioactive coating. In particular, Ti6Al4V ELI forgings (American Society for Testing and Materials (“ASTM”) F136) are used as scaffolding. A particularly suitable titanium alloy. Ti6Al4V ELI forgings are the industry standard titanium alloys used for medical purposes. Titanium alloys, but other titanium alloys include, but are not limited to, unalloyed titanium (ASTM F67) , Ti6Al4V standard grade (ASTM F1472), Ti6Al7Nb forgings (ASTM 1295), Ti5Al2.5Fe forgings ( British Standards Institute / International Organization for Standardization Part 10), CP and Ti6Al4V standard grade powders (ASTM F1 580), Ti6A13Nb13Zr forgings (ASTM 1713), low modulus Ti-24Nb-41Zr-8Sn and Ti-12Mo6Zr2F e forgings (ASTM 1813), and these other titanium alloys are suitable for various embodiments of the present invention. It may be true.

[0032] Titanium alloys are suitable scaffold materials because they are biocompatible and allow bone attachment. Various surface treatments can be applied to titanium alloys to increase or decrease the level of bone attachment. Bone adheres to uniformly polished titanium, but textured titanium enhances bone attachment. Methods to improve bone attachment to titanium include forging or milling processes, sanding, and can be produced by the use of laser blasting, acid etching and bioactive coatings. Titanium produced with 3D printing processes such as additive metal fabrication or direct metal laser sintering The parts are designed to reduce surface stress risers, normalize surface topography, and remove surface oxides. The grafts were then treated in an acid bath to improve the surface roughness and porosity of the grafts while maintaining the surface roughness and porosity required to promote bone attachment. It can be processed.

[0033] In addition, titanium or other alloys may be used with heparin, heparin sulfate (HS), glycosaminoglycans, Glycan (GAG), chondroitin-4-sulfate (C4S), chondroitin-6-sulfate ( C6S), hyaluronic acid (HY), and other proteolytic enzymes in the presence or absence of aqueous calcium solutions. Such treatments are typically performed when the material is in a pre-manufactured form (often a powder). ) or can be performed subsequently during fabrication of the structure.

[0034] Various structures, materials, surface treatments and coatings have been described, but repeated modifications Modified rhombic dodecahedron (MRDD) unit cell is used. The lattice provides a favorable combination of stiffness, strength, fatigue resistance, and conditions for bone ingrowth. In some embodiments, the repeating MRDD lattice may be made of titanium or The general rhombic dodecahedron (hereinafter referred to as RDD) is made of titanium alloy. A diamond shaped rhombus has, by definition, 12 sides. When repeated in a lattice ,An RDD unit cell consists of 24 struts, which meet at 14 vertices. The struts define 12 planar faces of the structure, and at the center of each face is a unit cell. Openings or interconnects are provided that allow flow from the interior to the exterior of the unit cell.

[0035] An embodiment B10 of the MRDD unit cell used in the present invention is shown in Figures 1A-1E. FIG. 1 is an isometric perspective view of a single MRDD unit cell B10, with radial alignment with portions of adjacent unit cells; Figure 1B shows a single MRDD unit cell B 10, showing the interconnection topology as viewed from the side. The top or bottom view of the MRDD unit cell B10 is almost identical to the side view shown in FIG. The RDD has different structural features and design methods from the general RDD shape. Each face is an identical rhombus with an acute angle of 70.5° and an obtuse angle of 109.5°. The shape of the rhomboid surface in the RDD does not change even if the size of the unit cell or the diameter of the struts changes. This means that the struts are indexed based on their axes and each This is because it passes through the centers or apexes of 14 nodes.

[0036] In some embodiments of the MRDD, each node defines a boundary and terminates at a strut. The MRDD or MRD is contained within a fixed volume that provides a fixed point in space for the The fixed volume containing the sub-unit cell of D may be, but is not limited to, a cubic volume, a rectangular prism volume, a hexahedral volume, The shape of the sphere can be of various shapes, including a square or amorphous volume. Some examples include six sided spheres. and eight corners, where the corners are defined where three faces meet. A fixed volume is used. The orientation of the struts is such that the center of the nodal surface at the proximal end and the distal end of the volume are Each node can be based on the corner closest to the node face in the More specifically, it is a square bipyramid (ie, a pyramid joined by a horizontal plane and an inverted pyramid). More preferably, each node located at the center of the rectangular parallelepiped volume is parallel to the surface of the rectangular parallelepiped volume. A rectangular plane, with six vertices, each of which is as close as possible to each of the six faces of the rectangular volume. The volume is centered with respect to the node location. means positioning the nodes approximately equal distances from opposite walls of the volume. In some embodiments, the nodes have a volume density of 100 percent, and in other embodiments, the nodes have a volume density of 100 percent. In some embodiments, the nodes may have a volume density of less than 100 percent. Each face of the cone can be a triangle, and each face provides a connection point for the support.

[0037] The strut is further formed of an octahedron having six nearly identical elongated faces and two end elongated portions. The elongated surface may have a first interior angle of angle A and a second interior angle of angle B, The end face can be an isosceles triangle with angle C greater than angle A. and the second interior angle is D, and angle D is greater than angle C. Preferably, angle C is greater than angle A.

[0038] The strut direction of each strut is the line or vector that defines the orientation of the strut and is the plane of each nodal surface. The MRDD and In the radial dodecahedral rhombus structure, the support direction is the center of the support end face, the center of mass along the support or by using a line connecting the outer edges or outer faces of the slender portion of the support. When the line connecting the centers of the end faces of the supports is used to determine the support direction, the line is Approximately parallel to the bottom surface or edge of the support. Use a line extending along the center of mass of the support. When defining the support direction, the line shall not be approximately parallel to the bottom surface or bottom edge of the support. The octahedral nodes of the MRDD can be adjusted to change the origin and size of the supports. However, the ends of the struts are The corners of the fixed volume formed around the nodes are locked, which allows the angle to be adjusted to each node face. The degree of melting changes as the volume density changes. In Fig. 1A, the dimensions of the fixed volume formed around each node do not change. Dash-dotted lines are drawn between the corners of the position cell B10 to indicate the boundary of the cube B11. In the MRDD unit cell at A, the height B12, width B13 and depth B14 of the unit cell is approximately the same as the area defined by the cube of B11.

[0039] In some embodiments, the strut direction is determined by the center of the node and the It can intersect at the corner of the rectangular volume closest to the node surface. The support direction of the support is the direction that intersects with the corner of the rectangular volume that is closest to the node surface to which the support is fixed. In some embodiments, the surface is defined by the faces of a rectangular parallelepiped or a hexahedron. The reference plane is used to describe the support direction of the support. When the support direction of the support is defined as the reference plane, it can be between 0° and 90° from the reference plane. When the angle is determined based on the above, it is preferably 8° to 30° from the reference plane.

[0040] The strut direction is oriented relative to the variable joint surface at one end and the fixed point at the distal end. By labelling, the resulting MRDD unit cell has a rhombus-shaped surface. It allows for smaller acute angles and larger obtuse angles than a typical RDD. The diamond shaped surface may have two substantially identical opposed acute angles and two substantially identical opposed obtuse angles. In some embodiments, the acute angle is less than 70.5° and the obtuse angle is less than 109. In some embodiments, the acute angle is between 0° and 55° and the obtuse angle is greater than 5°. Between 125° and 180°. In some embodiments, the acute angle is between 8° and 60°. The obtuse angle is between 120° and 172°. The reduction in the acute angle is due to the transition from an obtuse corner to a more obtuse corner. The reduction in acute angles and the increase in obtuse angles increase the fatigue resistance of the In addition, the struts increase the shear strength of the MRDD and also increase its fatigue resistance. By changing the corner angle from that of the general RDD, the shear load was increased in some of the supports. The rhombus corner angle is almost the same as that of the general RDD. By changing from , the overall deflection caused by the compressive load is further reduced and the Increases fatigue strength by resisting deflection in the

[0041] When positioned toward the center of the lattice structure, the 12 interconnects in the unit cell are 1 It connects to two different adjacent unit cells, resulting in a continuous path through the lattice. The size of the central cavity and interconnects can be defined using the longest dimension method described above. Using the longest dimension method, the central cavity shall be measured along the longest dimension shown in Figure 1C. In FIG. 1C, the longest dimension is labeled as distance AA. The distance AA can be in the vertical or horizontal direction (in this case, the direction is in the plane of the drawing). ), and in this embodiment are nearly identical. The interconnects are on the sides of the unit cells, It can be defined by the longest measurement when viewed from the top or bottom. The longest dimension is coded as distance AB. Distance AB can be in the vertical or horizontal direction. (In this case, the direction is based on the paper direction of the drawing.) The figure in Figure 1D is a side view, In this embodiment, the unit cell looks nearly identical when viewed from the top or bottom.

[0042] The size of the central cavity and interconnects may alternatively be determined by the largest sphere method described herein. Using this maximum sphere method, the central cavity can be defined as It can be defined by the diameter of the largest sphere that can fit within the central cavity. is an example of using the maximum sphere method to determine the size of the central cavity in a sphere having a diameter of BA. The interconnects are generally diamond shaped and their size may alternatively be determined by the size of the interconnects drawn within the apertures. The length and width of the three circles defining the side surface can be determined by the size of the length and width of the three circles defining the side surface. The first circle BB1 ​​is drawn at the center of the aperture, which fits without intersecting the support. The second circle BB2 and the third circle BB3 are tangent to the first circle BB1, and It is drawn to be the largest diameter circle that can fit onto the support without intersecting it. The diameter is the width of the interconnection, and the sum of all three diameters of circles BB1, BB2, and BB3 is This measurement represents the length of the interconnect. Eliminate sharp corners in the opening. In some cases, to limit additive manufacturing processes, It is beneficial to eliminate the sharp corners of the diamond shaped openings from the calculated size of the interconnect. For example, if an SLS machine has a resolution of 12 μm, which is accurate to within 5 μm, The bone may be rounded off by the SLS machine and may not be available for bone growth. This measurement system can be used when designing gratings that are to be manufactured with less accurate additive process equipment. It may be beneficial to use a stem to better approximate the size of the interconnect.

[0043] Using an alternative measurement method in some embodiments, the width of the interconnect is approximately 600 μm. and the length of the interconnect is about 300 μm. The use of pores of known size provides openings for bone growth and is approximately 1.8 mm square. This provides a surface area of ​​1 / 4 millimeter, allowing for high strength bone growth. In an alternative embodiment, the cross-sectional area of ​​the pore is 1.0 to 15.0 times the cross-sectional area of ​​the pore having a diameter of 300 μm. Another embodiment includes a pore cross section having a diameter of 900 μm. The interconnect may have a cross-sectional area of ​​1.0 to 15.0 times the product.

[0044] The MRDD unit cell further comprises at least two sets of substantially uniform pores or In some embodiments, the first pore set has the advantage of providing a set of aperture sizes. The first set of pores has a width of about 200 μm to about 900 μm, and the second set of pores has a width of about 1 / 2 the width of the first set of pores. In some embodiments, the first set of pores supports osteoblast growth. and the second set of pores may be configured to promote osteon in-growth. The pores sized to promote osteoblast growth are between approximately 100μm and 900μm in size. In some embodiments, the range of values ​​that can be used to stimulate osteoblast growth is Pores sized to promote osteon growth can have widths of over 900 μm. The pores of the facilitating size have widths that include values ​​between about 100 μm and 13.5 mm. In some embodiments, the pores may be sized to promote osteon growth. It may have a width greater than .5mm.

[0045] In some embodiments, a number of substantially uniform larger pores and a number of substantially uniform smaller pores. It is beneficial to include a large number of pores that are smaller than the number of larger pores, in which case the number of larger pores is greater than the number of smaller pores. For example, some embodiments may be selected based on the ratio of 1 Some embodiments have 1 large pore for every 25 small pores. In some embodiments, the large pores are spaced apart from each other. The number of holes and small holes is selected based on the percentage of the total number of holes in the lattice structure. For example, some embodiments may have large pores that are between 4 percent and 6 percent of the total number of pores. 50 percent of the total number of pores, and small pores make up 50 percent to 96 percent of the total number of pores. More preferably, some embodiments have large pores that make up 8 percent of the total number of pores. The pores are 87 to 92 percent of the total number of pores. The disclosed lattice comprised of two sets of substantially uniform pore sizes can include: It is believed that this provides a lattice structure that simultaneously promotes the growth of osteoblasts and osteons.

[0046] The MRDD unit cell may further comprise an interconnection when viewed from the side, top, or bottom of the unit cell. The MRDD unit cell can be defined by the size of the part. 1D has the same appearance as that in the side view shown in FIG. When viewed from the outside, the MRDD unit cell has a distinct diamond shape with nearly right angles. Four interconnects are shown. The area at each interconnect is the area in the plane of each interconnect. It is smaller when viewed from the side rather than perpendicular to the The area seen from the direction of the bone represents the area available for bone growth in that direction. In some embodiments, the thickness of the interconnect when viewed from the top, bottom, or side. It is desirable to index the unit cell and lattice properties based on area.

[0047] In some embodiments of the lattice structures described herein, the central cavity is equal to or greater than the length of the interconnects. is greater than the width. The size of each interconnect may be approximately the same in a repeating MRDD structure. Therefore, the resulting grating must consist of at least two distinctly sized apertures. In some embodiments, the diameter of the central cavity can be equal to or larger than the length of the interconnect. In some embodiments, the diameter of the central cavity is preferably about twice the diameter of the interconnect. It is preferable that the length of the slit is about four times the length of the slit.

[0048] In some embodiments, there is a relationship between the diameter of the central cavity and the length or width of the interconnect. The ratio can be varied to produce a structural grid of particular strength. In the present invention, the ratio between the diameter of the central cavity and the length or width of the interconnection is There is a relationship that increases as it increases.

[0049] Furthermore, a repeating radial dodecahedral rhombus (hereinafter referred to as "RDDR") unit cell is used. The lattice exhibits a favorable combination of stiffness, strength, fatigue resistance, and conditions for bone ingrowth. In some embodiments, the repeating RDDR grating can be made of titanium or a titanium alloy. FIG. 1G is an isometric view of a single RDDR unit cell B20 that contains the complete RDDR structure. FIG. 1H is a side view of a single RDDR unit cell B20, showing the mutual arrangement as viewed from the side. The top and bottom views of the RDDR unit cell B20 are shown in FIG. It is almost identical to the figure.

[0050] As used herein, the RDDR unit cell B20 is a unit cell that includes radial struts and their mirror images. It is a three-dimensional shape consisting of a central node with struts forming 12 diamond-shaped structures. The nodes are preferably octahedral, more particularly square bipyramids (i.e., square bipyramids joined by a horizontal plane). Each face of the node is a triangle, and six triangular elements are fixed to each face. A support consisting of a rectangular facet and two end faces. The central axis of each support is in the plane of each nodal face. The central axis may be perpendicular or non-perpendicular to the shaped surface. The RDDR further comprises a central node having one support attached to each side. This results in a square bipyramidal node with eight struts attached. do.

[0051] Examples of node and strut combinations are shown in Figures 1I-1M. Figure 1I shows a single strut B31. FIG. 1 is an isometric view of a single attached node B30. Node B30 is connected to node B30 and any The two vertices face the top and bottom surfaces of the volume B32 that defines the boundary of the attachment column B31. The node B30 is a square bipyramid oriented as follows: the horizontal corners of the node B30 are connected to the sides of the volume B32. The support B31 is oriented so as to be positioned at the point closest to the node B30. The corners of the volume B32 that define the boundaries of the node B30 and any attachment struts B31 from the surface of the In FIG. 1I, the central axis of the support forms an angle of 45° above the horizontal plane. , the planar surface of the node forms an angle of 45° above the horizontal plane.

[0052] FIG. 1I shows a detail of the octahedral support B31, with the dashed and dotted lines showing the hidden edge of the support. 31 is an octahedron having an elongated portion with six generally similar elongated faces and two end faces. The elongated surfaces B31a, B31b, B31c, B31d, B31e and B31f of the support B31 are , which define the outer surface of the elongated, somewhat cylindrical surface of the strut. c, B31d, B31e, and B31f are the first interior angle (angle A) and the second interior angle ( The support B31 is an isosceles triangle having an angle B, where angle B is greater than angle A. , the end faces B31f and B31g are In a substantially similar manner, it has a first interior angle (angle C) and a second interior angle (angle D), where angle D is greater than angle C. It is an isosceles triangle. The elongated faces B31a, B31b, B31c, B31d, B31e and B Comparing the interior angles of end faces B31f and B31g, angle C is larger than angle A. stomach.

[0053] FIG. 1J is a side view of node B30 and strut B31 bounded by volume B32. In this side view, the height of the node B30 compared to the height of the cube B32 is easily comparable. Figures 1K-1M show the structure of the node as viewed from a corner of a volume rather than a wall or face. FIG. 1 is a side view of a combination of a support and a strut, which reduces the volume density of the resulting unit cell. 1I-1J to change the angle. The height is increased relative to the height of volume B132. The ends of the pillars B131 are connected to the volume B13 Since the support B131 is fixed at the corner position of the two, the support B131 is attached in a non-orthogonal manner. The angle of the support B131 from the horizontal plane must be changed. The combination of the node B130 and the support B131, which has an angle of 20.6°, has an elastic modulus of approximately 3 GPa. This is suitable for a lattice structure that

[0054] In FIG. 1L, the height of the node B230 relative to the height of the cube B232 is The ratio of the nodes B230 and the struts B231 is increased to a ratio higher than that of the conventional combination. The combination is suitable for a lattice structure having an elastic modulus of about 4 GPa. As the height increases, the angle between pillar B231 and the horizontal plane decreases to approximately 18.8°. As the height of the nodes B230 increases, the size of the nodes also increases, thereby increasing the support. The size of pillar B231 is increased. The end of pillar B231 is fixed to the corner of volume B232. As the size of the distal end increases to accommodate the increased size of the nodal surface, the length As the size of the nodes and struts increases, The bulk density increases as does the elastic modulus. In Figure 1M, the results for the height of cube B332 are The height of the node B330 is increased from the ratio in FIG. 1M to the node B330 and the support B3 Thirty-one combinations were generated, and these combinations were used for a lattice structure with an elastic modulus of approximately 10 GPa. In this configuration, the angle between the support B331 and the horizontal plane is approximately 12.4 1° and the volume density is increased over the previous example. can be replicated and / or mirrored to produce unit cells of appropriate size and properties. For example, the angle between the support and the horizontal plane is 12.3 percent volumetric density and approximately 3 The angle can be increased to 25.8° to yield a lattice with an elastic modulus of 0.00 MPa. For clarity, a single node and strut are shown in the example, however, multiple struts may be attached to each node. The resulting unit cell can be attached to a substrate.

[0055] Adjacent struts extending from adjacent node faces in the upper or lower halves of the node are The lateral separation angle defined by the angle from the horizontal plane and the angle between the support directions of adjacent supports is In the MRDD and RDDR structures, adjacent columns have the closest The outer edges or faces of the elongated portions are adjacently extending. The lateral separation angles described herein are generally and between the outer edges or faces of the elongated portion of the strut that extends closest to the associated adjacent strut. In some embodiments, the angle is determined by the center of the strut end face and the center of mass of the strut. The lateral separation angle defined by a line extending between the line defined by the adjacent supports is This can be used in conjunction with similar calculations for columns.

[0056] The lateral separation angle is the angle between the closest faces or edges of a post to an adjacent post. The lateral separation angle is the distance between the nearest edges of the posts to the nearest edges of the adjacent posts. The smallest angle can be measured in a plane containing the edges of both supports. The separation angle is further defined as the distance between the nearest faces of the struts relative to the nearest faces of the adjacent struts. It can be measured as the smallest angle between the two support faces at right angles. In embodiments where there are no strut edges or faces that are spaced apart, the lateral separation angle is the closest to the adjacent struts. Measured as the angle between the closest points of one support to the nearest point For a unit cell in a cubic volume, the angle of the support from the horizontal plane decreases. As the angle increases, the lateral separation angle approaches 90°. For a unit cell in a cubic volume, As the strut angle from the horizontal plane increases, the lateral separation angle approaches 180°. In some embodiments, it is preferred to have a lateral separation angle greater than 109.5°. In some embodiments, it is preferred to have a lateral separation angle of less than 109.5°. In some embodiments, angles between about 108° and about 156° and between these values In some embodiments, the lateral separation angle is preferably between about 111° and about 1 More preferably, the lateral separation angles are between and including 56°. In some embodiments, angles between about 108° and about 120° and between these values More preferably, the lateral separation angle includes about 111° to about 120°. More preferably, the lateral separation angle is between and including about 120°. In some embodiments, the angle is between about 128° and about 156°. More preferably, the two adjacent struts B431 and B432 have a lateral separation angle of 15 degrees. A cubic section of a single node B430 to which B434 are attached and a lateral separation angle B443 is identified. 1 is a side view of the corner of the body B432. The lateral separation angle B443, when measured to the nearest edge, is about 116°.

[0057] In some embodiments, the unit cell is comprised of multiple sub-unit cells that are secured together. FIG. 1O illustrates an isometric view of an exemplary sub-unit cell consisting of a single node and four struts. FIG. A16 shows a top sub-unit cell flipped over and fixed on top of the bottom sub-unit cell. FIG. 1Q is an isometric view of two sub-unit cells in a stacked configuration. FIG. 1 is an isometric view of eight sub-unit cells stacked together to form a

[0058] In FIG. 1O, a node B530 has two vertices that are the top and bottom of a cubic volume B532. In some embodiments, the volume B532 is a square bipyramid oriented to face the is a rectangular prism volume, a hexahedral volume, an irregular volume, or has one or more non-orthogonal sides The vertices are the points where the four upper faces meet, and the points where the four lower faces meet. The node B530 is the point where the horizontal vertices of the cubic volume B53 The support B531 is oriented so as to face the side surface of the node B530 at its base end. The cubic volume B 532 is secured to the underside of the cubic volume B 532 and extends at its ends to the nearest corners of the cubic volume B 532. The ends of the struts B531 are sized to adjust the properties of the subunit cells. The volume of the cube B 532 can remain fixed even if the volume is changed.

[0059] The support B53 is fixed to the lower surface of the node B530 opposite to the surface to which the support B531 is fixed. The base end of the support B534 is fixed to the joint B530. The support pillar B535 extends to the nearest corner of the stack B532. The upper node B530 is fixed to the support B531 and is oriented at about 90° to the side from the surface of the node B530. The support B535 is fixed to the surface of the cubic volume B532 at its end. Extends to the nearest corner. Node B on the opposite side to the surface to which the support B535 is fixed The base end of the support B536 is fixed to the node B530 on the upper surface of the support B530. 6 extends at its extremities to the nearest corners of cubic volume B 532 .

[0060] In some embodiments, the struts B531 and B534-B536 have triangular faces. The support surface to be fixed to the surface of the node 530 is determined based on the size and orientation of the surface of the node 530. The supports fixed to the nearest corners of the cube B532 can be approximately the same as those used for the cube B532. The column surface is fixed to the node 530 and is approximately the same size as the column surface oriented in a substantially parallel plane. The remaining six faces are the first interior angle and the second interior angle that is larger than the first interior angle. Six approximately equal isosceles triangles with two interior angles. Isosceles triangles are fixed along their long edges to adjacent inverted nearly identical isosceles triangles. The grooves may be formed in a generally cylindrical shape with triangular ends.

[0061] When forming the sub-unit cell B540, the support B531 and B534 to B536 are fixed to the sub-unit cell B540. It may be beneficial to add eight nodes B538 to each corner of the cube B532. When replicating the sub-unit cell B540, the eight nodes B538 attached to the ends of each support are , ,combined with 8 nodes from adjacent sub-unit cells, located between the struts of the adjacent sub-unit cells. This forms a nodule.

[0062] FIG. A16 shows a second 50 mm thick plate for forming a quarter unit cell B560 for use in some embodiments. The first sub-unit cell B540 is fixed to the sub-unit cell B640. B640 is a square bipyramid with two vertices facing the top and bottom of a cubic volume. The support B635 has a square bipyramidal node B630 oriented in such a way that the support B635 faces the base end. It is fixed to the underside of the node B630 and extends to the nearest corner of the cubic volume at its end. The support B636 is fixed to the lower surface of the joint B630 on the opposite side to the surface to which the support B635 is fixed. The base end of the support B636 is fixed to the node B630. The support B636 is fixed at its base end to the support B635. The upper node B630 is fixed to a surface of the upper node B630 that is oriented approximately 90° to the side from the surface of the node B630 to which the The struts B634 extend at their ends to the nearest corners of the cubic volume. The support B634 is fixed to the upper surface of the node B630 on the opposite side to the surface to which the support B634 is fixed. The base end of the support B631 is fixed to the node B630. It extends to the nearest corner of the body volume.

[0063] The first sub-unit cell B540 is used as a reference point in the embodiment of FIG. A16. However, the second sub-unit cell B640 or other points can also be used as reference points. After the first sub-unit cell B540 is fixed in place, the second sub-unit cell B640 is The second sub-unit cell B640 is replicated so that it is substantially similar to the first sub-unit cell. The first sub-unit cell B 540 rotates about its central axis before being fixed to the top of the first sub-unit cell B 540. At 16, the second sub-unit cell B640 is flipped over to obtain the correct rotation, but the center axis of the second sub-unit cell B640 is rotated. Other rotations around the second sub-unit cell B 640 can achieve the same results. The first sub-unit cell B540 forms a quarter unit cell B560, and the quarter unit cell B560 The cells replicate and attach laterally to other quarter unit cells to form a complete unit cell. This can be done.

[0064] Alternatively, a complete unit cell may be formed by combining a first group of four substantially similar sub-unit cells. By fixing the plates to the sides, they form a square, rectangle or quadrilateral when viewed from above. Four nearly identical subunits rotated around their central axes can be The second group of holes is arranged to form a square, rectangle or quadrilateral when viewed from above. The second group of sub-unit cells can be laterally secured to one another. before rotating them about their central axis or after fixing them together to obtain the same result. After this, the second group can be inverted to the first group to form a complete unit cell. The hose is fixed to the top of the loop.

[0065] FIG. 1Q shows a complete unit cell formed by replicating the sub-unit cell B540 of FIG. 1O. 1 is an example of a sub-unit cell B770. For clarity, the boundaries of sub-unit cell B540 are defined. Identification of cube B532, node B530, and pillars B531 and B534-B536 The complete unit cell B770 of FIG. 1Q can be fabricated using the methods described above or within the concept of the present invention. The above-mentioned modifications can be used.

[0066] Each strut extending from a node for a given unit cell extends radially from the node. The length and angle of the two ends of the two conductors may be substantially the same so that the two ends of the two conductors form substantially the same length and angle with respect to the horizontal plane. At the end of each strut, the struts are spaced apart so that the struts extending from the node face form diamond-shaped openings. The struts can be non-orthogonal to the node surface, so that the two shapes A diamond shape appears. In this form, the first group of four diamonds are oriented in a vertical plane. The acute angles of the first group of diamonds are the angles of the struts relative to the horizontal plane. The obtuse angle is equal to 180 less the acute angle. In this embodiment, a second group of eight diamonds extends radially, and a third group of eight diamonds extends radially. A portion of the two groups is the lateral spacing angle between adjacent struts defining the first group of four. The acute angles of the second group of diamonds are included within the adjacent Approximately the same as the lateral separation angle between the posts, the obtuse angle being 180 less the acute angle The properties of a scaffold can be described by its surface area per volume. For a solid cube of 1.0 mm x 1.0 mm x 1.0 mm, its surface area is 6 square mm. The 1.0 cubic mm structure is made of a grid structure other than 100 percent volumetric density material. When the volume density of the scaffold is increased, the surface area per volume increases considerably. As the surface area per volume increases, so does the surface area per volume. In some embodiments, 30. A scaffold with a volume density of 1 percent has a surface area of ​​27.4 square millimeters per cubic millimeter. In some embodiments, when the volumetric density is reduced to 27.0 percent, the lattice has a surface area of ​​26.0 square millimeters per cubic millimeter and a volume density of 24.0 percent. If the surface area is reduced to 0.01 mm, the grid will have a surface area of ​​24.6 mm2 per cubic mm. .

[0067] The MRDD and RDDR structures described herein further provide particularly high performance for a given volumetric density. When used as a lattice or scaffold, it has the advantage of being able to achieve a suitable modulus and Implants with low volume density can be obtained, which is advantageous for bone ingrowth. The available implant volume is increased.

[0068] Table 1 below shows a number of exemplary lattice configurations at various lattice design moduli. The estimated actual elastic modulus is given for each example, which is the calculated elastic modulus of the lattice after it has gone through the manufacturing process. The lattice structures and implants described herein may be in several embodiments. The elastic modulus is designed to be the design modulus in the present embodiment and the approximate actual elastic modulus in other embodiments. One advantage of the lattice structures disclosed herein is that the approximate actual modulus of elasticity previously obtained can be During testing, one embodiment of the lattice exhibited a 4. The lattice was designed for a design modulus of 0 GPa. Under testing, the lattice achieved an actual modulus of 3.1 GPa. The actual modulus was within 77 percent of the design modulus.

[0069] For each lattice design modulus, the ratio of design modulus to volume density, the ratio of surface area to volume density, mm 2 The unit surface area ratio, the ratio of surface area to lattice design modulus, is given.

[0070] [Table 1]

[0071] In some embodiments described herein, the required strut thickness is calculated from the desired elastic modulus. Using the following equation, the strut thickness required to achieve a particular modulus can be calculated: , can be calculated for several MRDD and RDDR structures. Strut Thickness = (-0.0035 (E^2)) + (0.0696 E) + 0.4603

[0072] In the above equation, "E" is the modulus of elasticity. The modulus of elasticity is the required force to obtain its value. You can choose to determine the strut thickness or use a pre-selected strut thickness to calculate. The pole thickness is expressed in mm and represents the pole diameter. This pole thickness is determined by the preselected Calculate or select using a preselected modulus of elasticity to determine the modulus of elasticity for the strut thickness. It is possible.

[0073] In some embodiments, the unit cells are arranged in one or more layers to form a lattice with anisotropic properties. When the unit cell is elongated, it generally has a length of 10 mm. The elastic modulus in the direction perpendicular to the direction decreases. The elastic modulus in the elongated direction increases. In a direction perpendicular to the direction of new bone growth contained within the joints, openings and central cavity (if any) It is desirable to elongate the cells in a direction perpendicular to the desired direction of reduced modulus. By increasing the thickness, the shear strength in the elongate direction is increased, which is important when designing structural scaffolds. Co-varying the overall stiffness of the scaffold can provide a desirable set of qualities. The effect can be increased or decreased to allow for one or more directional changes.

[0074] In some embodiments, the sub-unit cells have a height that is proportional to the height of the volume that defines the sub-unit cell. The height of the nodes can be controlled to design the shape of the slits. The amount of heat generated can affect the final properties and appearance of the lattice structure. Increasing the height of the section increases the strut thickness, increases the volume density, increases the strength, and Increasing the node height increases the node width, which increases the elastic modulus of the resulting lattice. is held constant in some embodiments and allowed to vary in other embodiments. can be done.

[0075] In some embodiments, the sub-unit cells have a volume that defines the sub-unit cell. It can be designed by controlling the volume of the nodes. can affect the final properties and appearance of the lattice structure. Increasing the volume increases the strut thickness, increases the volume density, increases the strength, and When the volume of the nodes is increased, the width or height of the nodes is increased. The thickness may be held constant in some embodiments.

[0076] Table 2 below shows a number of exemplary lattice configurations at various lattice design moduli. The estimated actual elastic modulus is given for each example, which is the calculated elastic modulus of the lattice after it has gone through the manufacturing process. The lattice structures and implants described herein may be in several embodiments. The elastic modulus is designed to be the design modulus in the present embodiment and the approximate actual elastic modulus in other embodiments. For each lattice design modulus, the lattice estimated modulus, the node height, the volume density, the node volume of the grid, ratio of node height to volume density, ratio of node height to lattice design modulus, and volume density to The ratio of nodal volumes is given.

[0077] [Table 2]

[0078] Some embodiments of the disclosed lattice structures have a thermal resistance in the range between 0.375 GPa and 4.0 GPa. It is particularly useful when the elastic modulus is provided at values ​​including those in More preferably, the elastic modulus is in the range of 2.5 GPa to 4.0 GPa, including these values. In some embodiments, the lattice structure has a thickness between 5 percent and 40 percent. In some embodiments, the lattice structure has a volume density that includes these values ​​in the range. The volume density of these values ​​is within the range of 30% to 38%. There is a lattice structure having the following structure.

[0079] The lattice structures disclosed herein are particularly robust to the low bulk density and low modulus ranges. Some embodiments of the lattice structure have load and fatigue properties of 5,000, Static and dynamic loads of up to 10,000 cycles between 300 and 15,000 N and between these values Some embodiments have a shear yield load and a compression yield load that include 5 at 5 Hz. Static and dynamic loads of 300 to 15,000 N and up to 1,000,000 cycles Some embodiments have compressive shear strengths and axial loads inclusive of these values. Static and dynamic loads of 300 to 15,000 N for up to 5,000,000 cycles Some embodiments have a shear strength and axial load between and including these values. It has a torsional yield load of up to 1000 MPa.

[0080] In one embodiment, the grid structure of the present invention has a thickness between 32 percent and 38 percent. and volume density inclusive of these values, elastic modulus inclusive of 2.5GPa to 4GPa and these values, 300 to 5,000,000 cycles of static and dynamic loading at 5 Hz and 5 Hz. 15000N and axial loads between and including these values. A first set of substantially uniform openings having a width of about 200 μm to 900 μm and a second set of a second set of substantially uniform openings having a width of about 1 to 15 times the width of the opening of the first set; The number of openings in the second set is in a ratio of about 1:8 to 1:12 to the number of openings in the first set. Establish a system.

[0081] Constructs according to the present disclosure may be used in applications where osseointegration is not required or desired. may also benefit from the inclusion of a growth-inhibiting coating or skin on the structure. The lattices described herein provide structural support without providing a scaffold for bone growth. This can be used as a temporary measure that is intended to be removed after a period of time. This may be desirable when used in a medical implant or device.

[0082] First Example of a Fixation Plate 10 Configured for Use in a Temporary Implant 20 Exemplary embodiments are disclosed herein. The fixation plate may be used in a variety of applications, including but not limited to bone fusion implants. Designed to work with multiple types of implants, including vertebral and interbody fusion implants In some embodiments, the implant 20 may be a cervical stand-alone implant. In some embodiments, the implant is a catheter-sealed implant (hereinafter referred to as a CSA). The plant 20 is a lumbar interbody fusion stand-alone type (hereinafter referred to as "ALIF-SA") In some embodiments, the implant 20 is a posterior pathway lumbar spinal implant. It is a PLIF (prosthetic interbody fusion) implant. In some embodiments, The implant 20 is a transforaminal lumbar interbody fusion (hereinafter referred to as "TLIF") implant. In some embodiments, the implant 20 is a PLIF or TLI implant. In some embodiments, the implant 20 is a vertebral body replacement type ( In some embodiments, the implant is a varicose graft (VBR). In some embodiments, the implant 20 is an osteotomy wedge. Ankle fusion spacer implant. In some embodiments, implant 20 The fibrous structure is configured for tissue attachment, including but not limited to bone structures and connective tissue. In some embodiments, the implant 20 is configured to allow tissue ingrowth. The tissues include, but are not limited to, bone structure and connective tissue.

[0083] The fixation plate 10 is adapted to and / or support the implant after implantation. In some embodiments, the device may be configured to allow movement relative to the patient's tissue. The fixation plate is designed to compress the implant axially after implantation. In the embodiment of the fixation plate presented, the fixation plate is The implant is inserted so that the plate has at least one degree of freedom relative to the implant. Further, the fixation plate can be attached to the first bone and / or the second bone. Each attachment can have at least one degree of freedom. In an embodiment, the fixation plate is attached to the implant and / or tissue and each attachment point In some embodiments, the material can be attached to the substrate with more than one degree of freedom. In the present invention, the fixation plate is attached to the first bone and / or the second bone with a conical degree of freedom. This can be done.

[0084] Some embodiments of the fixation plate have screw holes with a concave contour and a concave ring in the screw hole. corresponding to the contour of the screw head, when viewed from the side of the end of the screw head facing the threaded portion A bone screw with a screw head is used to attach the bone to the patient's bone. The use of a concave contoured screw hole can result in fixation with at least a conical degree of freedom. The bone screw heads are secured to the screw holes of the fixation plate with a clearance fit greater than zero. In a sense, this clearance fit provides a certain amount of translation and also This can prevent jamming between the head and the screw hole of the fixing plate. The clearance fit used in this document is for conditions where there is a positive difference between the dimensions of the mating components. For example, a clearance fit refers to the diameter of a screw head being exactly the same as the diameter of a corresponding screw hole. It exists when the diameter is smaller than the

[0085] The fixation plate is designed to be attached to the implant in at least one degree of freedom using fastening means. Some embodiments of the fixation plate include a fixation plate and an implant. A fastening means having a clearance fit between the fastening means and the base is used. The use of the means may in some sense be a combination of or between fixation plates, implants and / or fastening means. Several types of suction cups can be used to provide a certain amount of translational movement and prevent pinching. Fastening means include, but are not limited to, quarter turn fasteners, screws, etc. The clearance fit for the fastener provides multiple translation directions in the axial and / or radial directions. It is possible.

[0086] The number of degrees of freedom that arise between two given components can be the result of multiple factors. These factors include, but are not limited to, design freedom, manufacturing tolerance freedom, or clearance fit freedom. This specification focuses on design freedom and, in some embodiments, intentional clearances. Focus on the degree of freedom of fit. However, of course, manufacturing tolerances can be measured and and / or create devices with the required degrees of freedom, as well as measure and use them. .

[0087] FIG. 1R is a side view of a fixation plate 10 rotatably attached to an implant. Although bone screws 30 are depicted, the fixation plate 10 is configured for use with two bone screws. In FIG. 1R, the fixation plate 10 is in a locked position relative to the implant 20. The locking positions used in the fine print shall be such that one element is locked relative to the other in at least one plane. Note that the object is fixed but has a degree of freedom of movement in at least one plane. In this embodiment, the fixation plate 10 is fixed to the implant 20 in the front-to-back direction. However, it is free to rotate around the axis in the front to rear direction. Although shown in the drawings in exemplary orientation, no limitation as to use or configuration is intended. In the drawings used, the posterior part of the implant 20 is adapted to receive the fixation plate 10. The anterior portion of the implant 20 is opposite to the posterior portion. The contralateral end of the implant. The portion of the implant between the anterior and posterior ends of the implant 20. The top to bottom direction of the implant 20 is referred to as the axial or compression direction. The exemplary fixation plate 10 and implant 20 are described in the axial and compression directions. It is designed for situations where the orientation is approximately the same, but does not have to be the same or similar.

[0088] FIG. 2 is an isometric view of the fixation plate 10, implant 20 and bone screw 30 in a locked position. The fixation plate 10 is implanted around an axis in the front-to-back direction. The fixation plate 10 and the implant 20 can be configured to rotate relative to each other. 0 is the angle of rotation between the implant 20 and the bone screw 30. The amount of axial compression permitted by the fixation plate 10 may be limited by the implant. The bone screws 30 may be adjusted based on the placement of the bone screws 30 relative to the implant 20. As one moves axially away from the implant 20, the amount of axial compression permitted decreases up to a given point. The amount of axial compression increases with the embedding of a particular length of the fixation plate 10 between the screw holes 11. The angle of the fixation plate 10 relative to the implant 20 after insertion can be estimated. For example, a fixation plate 10 having 10 mm spacing between screw hole centers would be suitable for implant 2. 50° angle to implant 20 than 45° angle to 0 The implantation with a 1 mm diameter allows for greater axial compression.

[0089] In some embodiments, the fixation plate 10 passes through the central axis of the implant 20. The implant 2 is aligned based on the orientation of a line drawn between the centers of the screw holes 11 relative to the plane of the implant 2. In some embodiments, the fixation plate 10 is oriented toward the axis 14 in the unlocked position. The implant 20 is oriented at an angle between -45° and 45° inclusive. In some embodiments, the fixation plate 10 is secured to the implant 20 in the locked position. In some embodiments, the angle is between 10° and 90° inclusive. In the locked position, the fixation plate 10 is at an angle between -10° and -90° relative to the implant 20. and points in the direction that contains those values.

[0090] 3 and 4 show the relationship between the fixation plate 10 and the implant 20 in the locked position. FIG. 1 is an additional explanatory diagram showing the locking position of the locking mechanism. Only one locking position is shown, but it should be understood that the locking position can be fixed. The fixed plate 10 may be more flexible than the implant 20 in this and other embodiments. can be rotated less.

[0091] FIG. 4A is a side view of fixation plate 10 and bone screw 30 showing hidden features in dashed lines. In some embodiments, the bone screw 30 has varying diameters that correspond to the varying diameters of the screw holes 11. In some embodiments, the screw may have a screw head 31 having a diameter that corresponds to the diameter of the screw. The head 31 has a convex contour when viewed from the side of the end of the screw head facing the threaded portion 32. In some embodiments, the screw hole 11 can be formed by a convex ring of the screw head 31. The implant may have a concave contour corresponding to the contour of the implant.

[0092] By using a screw head 31 with a convex profile and a screw hole 11 with a concave profile , a fixation having at least 40 conical degrees of freedom can be produced. The screw head 31 has a convex profile and the screw head 32 has a concave profile to provide a secure fit. Although the use of screw holes 11 has been disclosed herein, it will be appreciated that any other fastening device having similar characteristics may be used. Other methods exist in the prior art to obtain the conical degree of freedom of 0°. In some embodiments, the conical degree of freedom is in the range of 10° to 70°. In some embodiments, the conical degree of freedom is in the range of 20° to 40°. In some embodiments, the conical degree of freedom is in the range of 25° to 35°. In the above state, the conical degrees of freedom are in the range of 28° to 32°. The conical degree of freedom is approximately 30°.

[0093] The use of a screw head 31 having a convex profile and a screw hole 11 having a concave profile further Fixation with an infinite number of degrees of freedom can be achieved. 30 is threaded into the tissue segment such that there is a clearance fit 50 between the screw head 31 and the screw hole 11. The clearance fit 50 is the clearance fit between the screw head 31 of the fixing plate 10 and the , allowing for some design freedom and rotation along a certain amount in the direction of the clearance fit 50. In some embodiments, a clearance fit between the screw head 31 and the screw hole 11 is greater than zero. 50 is recommended to prevent biting.

[0094] In some embodiments, the screw hole 11 is circular and has a smooth inner surface, and the screw hole 11 is The screw holes 11 may be of a single diameter or a special shape. The screw hole 11 and the bone screw 30 may have a diameter taper to accommodate the bone screw 30. The bone screws 30 may optionally include anti-rotation features to inhibit rotation of the fixation plate 10 relative to the bone screws 30. It can be configured to do so.

[0095] FIG. 5 is a cross-sectional side view of fixation plate 10 and implant 20 in an unlocked position. The fixation plate 10 is further adapted to fit within the attachment port 22 of the implant 20. In some embodiments, the cylindrical member 12 and the mounting The mounting port 22 may further utilize partial relative rotation of the cylindrical member 12 or the mounting port 22. and inserting the pin, wedge, or tip against a surface configured to receive the pin, wedge, or tip. Or it has a 1 / 4 locking mechanism that engages the tip.

[0096] In the exemplary embodiment, the attachment port 22 further comprises an outer portion 23 and an inner portion 24. In some embodiments, the outer portion 23 is cylindrical. The outer portion 24 has a smaller diameter than the inner portion 24. The outer portion 24 is made of the material of the cylindrical member 12. One or two areas where material is being removed radially, corresponding to areas where material is being added radially. The material being added or removed may be added to the device. This may refer to the process during the design or manufacture of a device in which material is added. refers to a single continuous piece of material, and the device from which material is removed refers to the device being manufactured. It is possible.

[0097] FIG. 6 is a rear view of the fixation plate 10 and implant 20 in the unlocked position. In some embodiments, a tool for applying torque to the fixation plate 10 during implantation. An engagement area 13 may be provided on the fixing plate 10. Corresponding to the tool engagement area 13 The fixation plate 10 can be rotated using a tool having an extension that extends through the fixation plate 10 .

[0098] FIG. 7 is a rear view of an implant 20 configured to receive a fixation plate 10. In the exemplary embodiment, the cylindrical member 12 further includes opposing radially protruding portions. In this embodiment, the implant 20 has two pins 14 that extend from the attachment points. In the outer portion 23 of the port 22, two notches 25 extend radially in opposite directions. It is configured to receive pin 14. Of course, the disclosure of the pin and notch The configuration described above allows the fixation plate 10 to be attached to the implant 20 in an unlocked and locked position. This is just one way of allowing the placement of fewer than two may use more pins 14, or may use less than or more than two notches 25, and may use more than two pins 14. are spaced apart on cylindrical member 12 at intervals other than about 180°, and notches 25 are spaced apart at intervals other than about 180°. Distances other than 80° can be spaced apart on the outer portion of the mounting ports 22 .

[0099] FIG. 8 is a side cross-sectional view of the fixation plate 10 and implant 20 in a locked position. In this locked position, pins 24 projecting radially from cylindrical member 12 are The pin 24 provides a surface area that exceeds the diameter of the outer portion 23 of the mounting port 22. providing a surface that may be smaller than the diameter of the inner portion 24 and a fixing plate 10 allows unhindered rotation relative to the implant 20. The inner portion 24 is generally Although shown as cylindrical with approximately equal diameters, in some embodiments, the inner The portion 24 can be non-cylindrical or have a variable diameter. The inner portion 24 further comprises at least one pin 24 having a diameter smaller than the distance between the ends of the pins 24. In some embodiments, the inner portion 24 includes an area of ​​variable diameter. Further, the pins 24 may be spaced apart from each other to produce a local area having a diameter smaller than the distance between the ends of the pins 24. At least one area of ​​added material is included. The area is smaller than the distance between the ends of the pins 24. The use of a smaller diameter area reduces the rotation of the fixation plate 10 relative to the implant 20. This can cause a stop.

[0100] FIG. 9 is an isometric cross-sectional view of an implant configured to receive a fixation plate. FIG. 10 is a top cross-sectional view of an implant configured to receive a fixation plate. These figures use mounting port 22, outer portion 23, inner portion 24 and notch 25. 13 provides additional diagrams of an example configuration.

[0101] What has been described thus far is a fixation plate and a device adapted to receive the disclosed fixation plate. In the present disclosure, only exemplary embodiments of the present invention are described. Although shown and described, the present invention is capable of use in various other combinations and environments. It is understood that modifications or variations are possible within the scope of the inventive concept as expressed herein. I want to be.

Claims

1. an implant configured for implantation within a body and including at least one side; an elongated plate selectively and rotatably secured to the side of the implant; 1. A medical implant system comprising: The elongated plate is configured to receive one or more fasteners therethrough. A medical implant system having a plurality of apertures.

2. 2. The medical implant system of claim 1, wherein the plurality of openings are The medical implant system is further configured to rotate about a

3. 10. The medical implant system of claim 1, wherein the plurality of openings further comprises a first a smooth annular shape having a diameter, the fastener further comprising a smooth annular shape having a second diameter. a medical implant having a head with a generally annular shape, the second diameter being smaller than the first diameter. system.

4. 2. The medical implant system of claim 1, The implant further has an anterior-posterior direction, a lateral direction, and an axial direction; The elongated plate is adapted to allow at least one degree of freedom for the implant. The medical implant system is configured as follows.

5. 5. The medical implant system of claim 4, wherein the elongated plate further comprises: a fixed position in an anterior-posterior direction relative to the implant; A medical implant system configured to rotate about an axis in a front-to-back direction. 。

6. 10. The medical implant system of claim 1, wherein the implant further comprises: a forward direction, a rearward direction, a lateral direction, and an axial direction; The elongated plate is adapted to allow at least one degree of freedom for the implant. The medical implant system is configured as follows.

7. 7. The medical implant system of claim 6, wherein the self-insertion mechanism is adapted to receive the implant. The medical implant system, wherein the degree of freedom further includes an axial direction.

8. 10. The medical implant system of claim 1, wherein the elongated plate further comprises: a quarter turn fastener extending toward the side of the implant; The implant further comprises a quarter turn fastener located on the elongated plate. The medical implant system has a corresponding opening.

9. 10. The medical implant system of claim 1, wherein the elongated plate further comprises: The implant is fixed to be translatable in all directions, and the implant is fixed to be translatable in all directions.

13. A medical implant system, comprising: a medical implant system that is freely rotatable in at least one direction.

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