Patent Description:
Spinal pathologies and disorders such as scoliosis and other curvature abnormalities, kyphosis, degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, tumor, and fracture may result from factors including trauma, disease and degenerative conditions caused by injury and aging. Spinal disorders typically result in symptoms including deformity, pain, nerve damage, and partial or complete loss of mobility.

Non-surgical treatments, such as medication, rehabilitation and exercise can be effective, however, may fail to relieve the symptoms associated with these disorders. Surgical treatment of these spinal disorders includes correction, fusion, fixation, discectomy, laminectomy and implantable prosthetics. As part of these surgical treatments, spinal constructs including bone fasteners are often used to provide stability to a treated region. Such bone fasteners are traditionally manufactured using a medical machining technique. This disclosure describes an improvement over these prior technologies.

<CIT> discloses a method for manufacturing a bone pin for connection to a bone, particularly for fixing an implant to a bone, the bone pin having an implant contacting part arranged to contact the implant in connected situation and a bone contacting part arranged to engage the bone in connected situation, wherein the method comprises the steps of: - providing bone information which is indicative for the bone which the bone contacting part is arranged to engage; - providing a bone contacting part which is customized on the basis of the bone information for engaging said bone; - providing an implant contacting part; and - assembling the bone contacting part and the implant contacting part for manufacturing the pin.

<CIT> provides a bone screw or bone anchor, such as a threaded pedicle screw or the like, incorporating a porous surface for enhancing bony fixation, ingrowth, and purchase when implanted in bone. Preferably, this porous surface covers at least a portion of the threads of the bone screw or bone anchor. The porous surface is formed by a conventional or novel additive manufacturing process, such as three-dimensional (3D) printing or the like, optionally as well as a prior and/or subsequent machining process. The porous surface may include novel needle-like protrusions and/or lattice structures, and/or any other protruding/depressed features, whether regular or irregular.

According to <CIT>, a bone screw includes a main body having a proximal end and a distal end. The main body extends along a longitudinal axis. The main body has an externally threaded surface that includes at least one helically extending thread having a minor diameter and a major diameter, which major diameter is greater than the minor diameter. The thread includes at least two flank surfaces extending between the minor diameter and the major diameter. The minor diameter of the thread defines a central portion of the main body. The thread may include at least one aperture that extends along an aperture axis through the thread between the flank surfaces.

The invention provides a bone fastener according to claim <NUM> and a method for fabricating a bone fastener according to claim <NUM>.

The exemplary embodiments of a surgical system and related methods of use disclosed are discussed in terms of medical devices for the treatment of musculoskeletal disorders and more particularly, in terms of a spinal implant system having spinal implants manufactured by a method including a plurality of manufacturing techniques. In some embodiments, the spinal implant system includes a spinal implant comprising a bone screw including a hybrid medical device. In some embodiments, the spinal implant is manufactured via a traditional manufacturing technique and an additive manufacturing technique.

In some embodiments, the spinal implant system of the present disclosure comprises a spinal implant, surgical instrument and/or medical device having a hybrid configuration that combines a manufacturing method, such as, for example, one or more traditional manufacturing features and materials and a manufacturing method, such as, for example, one or more additive manufacturing features and materials. In some embodiments, additive manufacturing includes <NUM>-D printing. In some embodiments, additive manufacturing includes fused deposition modeling, selective laser sintering, direct metal laser sintering, selective laser melting, electron beam melting, layered object manufacturing and stereolithography. In some embodiments, additive manufacturing includes rapid prototyping, desktop manufacturing, direct manufacturing, direct digital manufacturing, digital fabrication, instant manufacturing and on-demand manufacturing.

In some embodiments, the spinal implant system of the present disclosure comprises a spinal implant, such as, for example, a bone screw manufactured by combining traditional manufacturing methods and additive manufacturing methods. In some embodiments, the bone screw is manufactured by applying additive manufacturing material in areas where the bone screw can benefit from materials and properties of additive manufacturing. In some embodiments, traditional materials are utilized where the benefits of these materials, such as physical properties and cost, are superior to those resulting from additive manufacturing features and materials.

In some embodiments, the bone screw is manufactured by combining traditional manufacturing methods and additive manufacturing such that a distal end of the bone screw is manufactured by additive manufacturing while a proximal end is manufactured by traditional methods and materials, such as, for example, subtractive manufacturing. In some embodiments, the proximal end is manufactured by wrought or from other materials that have enhanced physical properties relative to additive materials. In some embodiments, the distal end of the screw is subjected to higher loads and the physical properties of traditional materials offer benefits in performance and cost when compared to additive materials. In some embodiments, utilizing additive manufacturing to create the distal end of the bone screw can provide a bone in-growth surface along with complex internal and external features.

In some embodiments, the surgical system of the present disclosure comprises combining traditional manufacturing methods and materials with additive manufacturing to fabricate a spinal implant, such as, for example, a hybrid bone screw that facilitates bony fixation, ingrowth and purchase with tissue. In some embodiments, the hybrid bone screw provides improvement in stability of the bone screw when the distal end is engaged with tissue. In some embodiments, the bone screw is disposable with tissue in a cantilever configuration that supports a load on the hybrid bone screw in an even distribution. For example, a proximal portion of a bone screw fabricated from a traditional manufacturing method can include strength and stability features for supporting a load, for example, connection with a spinal rod. A distal portion of the bone screw fabricated from an additive manufacturing method can include fixation, ingrowth and porosity features, for example, to facilitate purchase with tissue. In some embodiments, applications of the present hybrid manufacturing technique employed for producing surgical instruments allows additive features to be added to a surgical instrument such that the surgical instrument includes selected features and/or features with complex internal geometry.

In some embodiments, the proximal end is manufactured by a traditional manufacturing method that employs a lathe, Swiss lathe, mill turning, whirling, grinding and/or roll forming. In some embodiments, the proximal end is disposed with a part, such as, for example, a build plate in connection with an additive forming technique. In some embodiments, the plate includes one or a plurality of openings configured for disposal of the proximal end. In some embodiments, the openings are threaded to facilitate connection of the proximal end with the plate. In some embodiments, the threaded surface is utilized to control thread orientation and timing of deposition and/or heating. In some embodiments, the openings are selectively shaped to facilitate connection with the proximal end. In some embodiments, the plate includes cavities, such as, for example, pockets that are selectively shaped to facilitate connection with the proximal end. In some embodiments, a distal face of the proximal end is engaged with one of the openings such that the distal face is disposed in a flush orientation with a surface of the plate. In some embodiments, the proximal end is disposed perpendicular to the plate. In some embodiments, the proximal end may be disposed in various orientations relative to the plate.

In some embodiments, the method of manufacturing the distal end includes a step of connecting the proximal end with the plate. In some embodiments, the method of manufacturing the distal end includes the step of providing a heat source to heat a powder deposited on the distal face of the proximal end. In some embodiments, the method of manufacturing the distal end includes the step of leveling the powder to a consistent thickness. In some embodiments, the method of manufacturing the distal end includes the step of melting the powder. In some embodiments, the method of manufacturing the distal end includes the step of translating the plate, such as, for example, in a downward direction to facilitate applying additional layers of the powder. In some embodiments, the method of manufacturing includes the step of disengaging the bone screw, such as, for example, by unscrewing the bone screw from the plate.

In some embodiments, the surgical system of the present disclosure comprises a threaded pedicle screw including a porous portion for enhancing bony fixation, ingrowth and purchase when implanted in bone. In some embodiments, the porous portion is manufactured on a distal surface of a proximal portion. In some embodiments, the porous portion is formed by <NUM>-D printing. In some embodiments, the proximal portion of the bone screw is substantively manufactured and the distal portion is additively manufactured. In some embodiments, the distal portion may include needle-like protrusions and/or lattice structures, and/or protruding/depressed features, whether regular or irregular. In some embodiments, the materials utilized to manufacture the bone screw include stainless steel, titanium, cobalt-chromium, polymers, silicone, biologics and/or tissue. In some embodiments, the bone screw can be manufactured using wrought, forged, metal injection molded, roll formed, injection molded and/or machined materials, as described herein. In some embodiments, the distal portion is manufactured by additive manufacturing and connected with the proximal portion. In some embodiments, the distal portion is manufactured by additive manufacturing and mechanically attached with the proximal portion by, for example, welding, threading, adhesives and/or staking.

In some embodiments, the spinal implants, surgical instruments and/or medical devices of the present disclosure may be employed to treat spinal disorders such as, for example, degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, scoliosis and other curvature abnormalities, kyphosis, tumor and fractures. In some embodiments, the spinal implants, surgical instruments and/or medical devices of the present disclosure may be employed with other osteal and bone related applications, including those associated with diagnostics and therapeutics. In some embodiments, the spinal implants, surgical instruments and/or medical devices of the present disclosure may be alternatively employed in a surgical treatment with a patient in a prone or supine position, and/or employ various surgical approaches to the spine, including anterior, posterior, posterior mid-line, lateral, postero-lateral, and/or antero-lateral approaches, and in other body regions such as maxillofacial and extremities. The spinal implants, surgical instruments and/or medical devices of the present disclosure may also be alternatively employed with procedures for treating the lumbar, cervical, thoracic, sacral and pelvic regions of a spinal column. The spinal implants, surgical instruments and/or medical devices of the present disclosure may also be used on animals, bone models and other non-living substrates, such as, for example, in training, testing and demonstration.

The present disclosure may be understood more readily by reference to the following detailed description of the embodiments taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this application is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting. In some embodiments, as used in the specification and including the appended claims, the singular forms "a," "an," and "the" include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" or "approximately" one particular value and/or to "about" or "approximately" another particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It is also understood that all spatial references, such as, for example, horizontal, vertical, top, upper, lower, bottom, left and right, are for illustrative purposes only and can be varied within the scope of the disclosure. For example, the references "upper" and "lower" are relative and used only in the context to the other, and are not necessarily "superior" and "inferior".

As used in the specification and including the appended claims, "treating" or "treatment" of a disease or condition refers to performing a procedure that may include administering one or more drugs to a patient (human, normal or otherwise or other mammal), employing implantable devices, and/or employing instruments that treat the disease, such as, for example, microdiscectomy instruments used to remove portions bulging or herniated discs and/or bone spurs, in an effort to alleviate signs or symptoms of the disease or condition. Alleviation can occur prior to signs or symptoms of the disease or condition appearing, as well as after their appearance. Thus, treating or treatment includes preventing or prevention of disease or undesirable condition (e.g., preventing the disease from occurring in a patient, who may be predisposed to the disease but has not yet been diagnosed as having it). In addition, treating or treatment does not require complete alleviation of signs or symptoms, does not require a cure, and specifically includes procedures that have only a marginal effect on the patient. Treatment can include inhibiting the disease, e.g., arresting its development, or relieving the disease, e.g., causing regression of the disease. For example, treatment can include reducing acute or chronic inflammation; alleviating pain and mitigating and inducing regrowth of new ligament, bone and other tissues; as an adjunct in surgery; and/or any repair procedure. Also, as used in the specification and including the appended claims, the term "tissue" includes soft tissue, ligaments, tendons, cartilage and/or bone unless specifically referred to otherwise.

The following discussion includes a description of a spinal implant, a method of manufacturing a spinal implant, related components and methods of employing the surgical system in accordance with the principles of the present disclosure. Alternate embodiments are disclosed. Reference is made in detail to the exemplary embodiments of the present disclosure, which are illustrated in the accompanying figures. Turning to <FIG>, there are illustrated components of a spinal implant system <NUM> including spinal implants, surgical instruments and medical devices.

Spinal implant system <NUM> includes a spinal implant, such as, for example, a bone fastener <NUM> that defines a longitudinal axis X1. Bone fastener <NUM> includes an elongated screw shaft <NUM> having a proximal portion <NUM> fabricated by a first manufacturing method and a distal portion <NUM> fabricated by a second manufacturing method to enhance fixation and/or facilitate bone growth, as described herein. In some embodiments, the manufacturing method can include a traditional machining method, such as, for example, subtractive, deformative or transformative manufacturing methods. In some embodiments, the traditional manufacturing method may include cutting, grinding, rolling, forming, molding, casting, forging, extruding, whirling, grinding and/or cold working. In some embodiments, the traditional manufacturing method includes portion <NUM> being formed by a medical machining process. In some embodiments, medical machining processes can include use of computer numerical control (CNC) high speed milling machines, Swiss machining devices, CNC turning with living tooling, wire EDM <NUM>th axis and/or Solid Works™ CAD, and Virtual Gibbs™ solid model rendering. In some embodiments, the manufacturing method for fabricating portion <NUM> includes a finishing process, such as, for example, laser marking, tumble blasting, bead blasting, micro blasting and/or powder blasting.

For example, portion <NUM> is formed by a manufacturing method, which includes feeding a straightened wire W into a machine that cuts wire W at a designated length to form a screw blank, as shown in <FIG>, and die cuts a head of the screw blank into a selected configuration, as shown in <FIG>. Portion <NUM> is manufactured to include a head <NUM> and a portion of screw shaft <NUM>. Portion <NUM> extends between an end <NUM> and an end <NUM>. End <NUM> includes head <NUM>.

Portion <NUM> includes threads <NUM>, which are fabricated by traditional machining methods, as described herein. Threads <NUM> extend along all or a portion of portion <NUM>. Threads <NUM> are oriented with portion <NUM> and disposed for engagement with tissue. In some embodiments, threads <NUM> include a fine, closely-spaced configuration and/or shallow configuration to facilitate and/or enhance engagement with tissue. In some embodiments, threads <NUM> include a smaller pitch or more thread turns per axial distance to provide a stronger fixation with tissue and/or resist loosening from tissue. In some embodiments, threads <NUM> include a greater pitch and an increased lead between thread turns. In some embodiments, threads <NUM> are continuous along portion <NUM>. In some embodiments, threads <NUM> are continuous along shaft <NUM> via a second manufacturing method, as described herein. In some embodiments, threads <NUM> may be intermittent, staggered, discontinuous and/or may include a single thread turn or a plurality of discrete threads. In some embodiments, other penetrating elements may be located on and/or manufactured with portion <NUM>, such as, for example, a nail configuration, barbs, expanding elements, raised elements, ribs, and/or spikes to facilitate engagement of portion <NUM> with tissue.

End <NUM> includes a surface <NUM> that defines a distal face <NUM>. In some embodiments, surface <NUM> may be disposed along a length of portion <NUM> or at a distalmost surface of portion <NUM>. In some embodiments, distal face <NUM> extends perpendicular to axis X1, as shown in <FIG>. In some embodiments, distal face <NUM> may be disposed in various orientations relative to axis X1, such as, for example, transverse and/or at angular orientations, such as acute or obtuse. In one embodiment, as shown in <FIG>, distal face <NUM> is disposed at an acute angular orientation relative to axis X1.

Distal face <NUM> is configured for providing a fabrication platform for forming portion <NUM> thereon with an additive manufacturing method, as described herein. Distal face <NUM> has a substantially planar configuration for material deposition and/or heating during an additive manufacturing process for fabricating portion <NUM> onto distal face <NUM>. In some embodiments, all or only a portion of distal face <NUM> may have alternate surface configurations, such as, for example, angled, irregular, uniform, non-uniform, offset, staggered, tapered, arcuate, undulating, mesh, porous, semi-porous, dimpled, pointed and/or textured. In some embodiments, distal face <NUM> may include a nail configuration, barbs, expanding elements, raised elements, ribs, and/or spikes to provide a fabrication platform for forming portion <NUM> thereon with an additive manufacturing method, as described herein. In some embodiments, all or only a portion of distal face <NUM> may have alternate cross section configurations, such as, for example, oval, oblong triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, and/or tapered.

Portion <NUM> is fabricated with a second manufacturing method by disposing a material M onto distal face <NUM>, as described herein. Portion <NUM> is configured for fabrication on distal face <NUM> such that portion <NUM> is fused with surface <NUM>. Portion <NUM> is formed on distal face <NUM> by an additive manufacturing method. In some embodiments, portion <NUM> is fabricated by depositing material M onto distal face <NUM> one layer at a time, as described herein.

In some embodiments, additive manufacturing includes <NUM>-D printing, as described herein. In some embodiments, additive manufacturing includes fused deposition modeling, selective laser sintering, direct metal laser sintering, selective laser melting, electron beam melting, layered object manufacturing and stereolithography. In some embodiments, additive manufacturing includes rapid prototyping, desktop manufacturing, direct manufacturing, direct digital manufacturing, digital fabrication, instant manufacturing or on-demand manufacturing. In some embodiments, portion <NUM> is manufactured by additive manufacturing, as described herein, and mechanically attached with surface <NUM> by, for example, welding, threading, adhesives and/or staking.

In one embodiment, as shown in <FIG>, one or more manufacturing methods for fabricating distal portion <NUM>, proximal portion <NUM> and/or other components of bone fastener <NUM> include imaging patient anatomy with imaging techniques, such as, for example, x-ray, fluoroscopy, computed tomography (CT), magnetic resonance imaging (MRI), surgical navigation, and/or acquirable <NUM>-D or <NUM>-D images of patient anatomy. Selected configuration parameters of distal portion <NUM>, proximal portion <NUM> and/or other components of bone fastener <NUM> are collected, calculated and/or determined. Such configuration parameters can include one or more of patient anatomy imaging, surgical treatment, historical patient data, statistical data, treatment algorithms, implant material, implant dimensions, porosity and/or manufacturing method. In some embodiments, the configuration parameters can include implant material and porosity of distal portion <NUM> determined based on patient anatomy and the surgical treatment. In some embodiments, the implant material includes a selected porosity P of distal portion <NUM>, as described herein. In some embodiments, the selected configuration parameters of distal portion <NUM>, proximal portion <NUM> and/or other components of bone fastener <NUM> are patient specific. In some embodiments, the selected configuration parameters of distal portion <NUM>, proximal portion <NUM> and/or other components of bone fastener <NUM> are based on generic or standard configurations and/or sizes and not patient specific. In some embodiments, the selected configuration parameters of distal portion <NUM>, proximal portion <NUM> and/or other components of bone fastener <NUM> are based on one or more configurations and/or sizes of components of a kit of spinal implant system <NUM> and not patient specific.

For example, based on one or more selected configuration parameters, as described herein, a digital rendering and/or data of a selected distal portion <NUM>, proximal portion <NUM> and/or other components of bone fastener <NUM>, which can include a <NUM>-D or a <NUM>-D digital model and/or image, is collected, calculated and/or determined, and generated for display from a graphical user interface, as described herein, and/or storage on a database attached to a computer and a processor (not shown), as described herein. In some embodiments, the computer provides the ability to display, via a monitor, as well as save, digitally manipulate, or print a hard copy of the digital rendering and/or data. In some embodiments, a selected distal portion <NUM>, proximal portion <NUM> and/or other components of bone fastener <NUM> can be designed virtually in the computer with a CAD/CAM program, which is on a computer display. In some embodiments, the processor may execute codes stored in a computer-readable memory medium to execute one or more instructions of the computer, for example, to transmit instructions to an additive manufacturing device, such as, for example, a <NUM>-D printer. In some embodiments, the database and/or computer-readable medium may include RAM, ROM, EPROM, magnetic, optical, digital, electromagnetic, flash drive and/or semiconductor technology. In some embodiments, the processor can instruct motors (not shown) that control movement and rotation of spinal implant system <NUM> components, for example, a build plate <NUM>, distal face <NUM> and/or laser emitting devices, as described herein.

In some embodiments, the components of spinal implant system <NUM> can include one or more computer systems. In some embodiments, the components of spinal implant system <NUM> can include computers and/or servers of a network having a plurality of computers linked to each other over the network, Wi-Fi, Internet, comprise computers connected via a cloud network or in a data drop box. In some embodiments, the graphical user interface may include one or more display devices, for example, CRT, LCD, PDAs, WebTV terminals, set-top boxes, cellular phones, screen phones, smart phones, iPhone, iPad, tablet, wired or wireless communication devices.

Portion <NUM> is fabricated with threads <NUM> by a first manufacturing method, as described herein. Portion <NUM> is connected with a part, such as, for example, a build plate <NUM> in connection with an additive forming process and a second manufacturing method for fabricating distal portion <NUM>. Build plate <NUM> is selectively configured for fabricating a selectively configured distal portion <NUM>, as described herein, and disposed with a working chamber <NUM> of a powder bed additive manufacturing apparatus <NUM>, as shown in <FIG> and <FIG>. An enclosure <NUM> of apparatus <NUM> defines working chamber <NUM>.

Apparatus <NUM> includes a heating device, such as, for example, a laser device <NUM> disposed with working chamber <NUM> that fuses material M, which includes a powder, as described herein, in a slice by slice, layer by layer formation of portion <NUM> onto distal face <NUM>. In some embodiments, laser device <NUM> includes an interactive laser and optics system that produces a laser beam scanned over a layer of material M powder disposed on build plate <NUM> to selectively heat the powder according to instructions received from the computer and processor based on the digital rendering and/or data of the selected configuration of portion <NUM>. Laser device <NUM> heats a thin layer of material M powder in accordance with slice data based on the digital rendering and/or data to fabricate portion <NUM>, layer by layer, via an additive manufacturing technique. See, for example, the additive and three dimensional manufacturing systems and methods described in <CIT> and <CIT>.

In some embodiments, apparatus <NUM> includes a radiation source that melts and solidifies material M disposed with distal face <NUM> into a desired three-dimensional shape based on the selected configuration parameters, as described herein. In some embodiments, the radiation source includes laser device <NUM>, which comprises a carbon dioxide laser. In some embodiments, laser device <NUM> may include a beam of any wavelength of visible light or UV light. In some embodiments, apparatus <NUM> emits alternative forms of radiation, such as, for example, microwave, ultrasound or radio frequency radiation. In some embodiments, laser device <NUM> is configured to be focused on a portion of distal face <NUM> to sinter material M deposited thereon, as shown in <FIG>. In some embodiments, laser device <NUM> emits a beam having a diameter between about <NUM> and about <NUM>. In some embodiments, the diameter of the beam may be between about <NUM> and about <NUM>. In some embodiments, the diameter of the beam is adjustable to customize the intensity of the sintering.

Build plate <NUM> includes a surface <NUM> that defines one or a plurality of openings <NUM>. Each opening <NUM> is configured for disposal of proximal portion <NUM> to orient distal face <NUM> as a fabrication platform for forming portion <NUM> thereon with an additive manufacturing method, as described herein. The portions of surface <NUM> that define openings <NUM> are threaded with surface <NUM> to facilitate connection with portion <NUM>. Portion <NUM> is threaded with openings <NUM>, as shown in <FIG>. Distal face <NUM> is disposed with opening <NUM> in a flush orientation with surface <NUM>, as shown in <FIG>, to orient distal face <NUM> for selective laser melting with a powder bed process by apparatus <NUM>.

In some embodiments, openings <NUM> are oriented with plate <NUM> to control thread orientation and timing of deposition and/or heating of material M with distal face <NUM> to fabricate portion <NUM> in accordance with selected configuration parameters, as described herein. Surface <NUM> is threaded with surface <NUM> and distal face <NUM> is disposed with opening <NUM> in a perpendicular orientation relative to surface <NUM> and axis X1, as shown in <FIG>. In some embodiments, distal face <NUM> may be disposed with opening <NUM> in various orientations relative to surface <NUM>, such as, for example, transverse and/or at angular orientations, such as acute or obtuse. In one embodiment, as shown in <FIG>, surface <NUM> is threaded with surface <NUM> and distal face <NUM> is disposed with opening <NUM> at an acute angular orientation relative to axis X1. In some embodiments, portion <NUM> may be disposed with opening <NUM> in alternate connection configurations, such as, for example, friction fit, pressure fit, locking protrusion/recess, locking keyway and/or adhesive.

In some embodiments, surface <NUM> includes pockets (not shown) disposed adjacent openings <NUM> that are selectively shaped to form selective configurations of portion <NUM>, as described herein. In some embodiment plate <NUM> may be substantially non-conductive. In some embodiments, plate <NUM> may be ceramic, glass or non-metallic. In some embodiments, plate <NUM> may be formed of an electrical insulating material that is operable to prevent an external heat control mechanism from heating plate <NUM> to a sintering temperature of material M that is utilized to form the layers.

Build plate <NUM> is mounted with a platform <NUM> of apparatus <NUM> such that build plate <NUM> can be moved relative to enclosure <NUM> in one or more directions to generate distal portion <NUM> onto distal face <NUM>, layer by layer, based on the digital rendering and/or data. In some embodiments, build plate <NUM> can be translated vertically, horizontally or diagonally, rotated, pivoted, raised and/or lowered to generate distal portion <NUM>. In some embodiments, build plate <NUM> can be moved relative to enclosure <NUM> slidably, continuously, incrementally, intermittently, automatically, manually, selectively and/or via computer/processor control. In some embodiments, apparatus <NUM> comprises an additive manufacturing device that employs selective laser melting with a powder bed process to create 3D objects. See, for example, the Lasertec <NUM> SLM additive manufacturing machine manufactured by DMG MORI Co. located at <NUM>-<NUM>-<NUM> Meieki, Nakamura-ku, Nagoya City <NUM>-<NUM>, Japan.

In some embodiments, apparatus <NUM> is connected with one or more computer systems, processors and databases, as described herein, to receive commands and instructions for creating distal portion <NUM> onto distal face <NUM> by selective laser melting with a powder bed process by apparatus <NUM>. For example, the commands and instructions are based on the one or more selected configuration parameters of a selected distal portion <NUM> generated for display from a graphical user interface and/or stored on a database, as described herein. In some embodiments, apparatus <NUM> and/or the one or more computer systems can include a keyboard to input commands and instructions. In some embodiments, the processor receives the instructions and directs apparatus <NUM> to fabricate portion <NUM> based on the received instructions.

Material M powder is introduced in working chamber <NUM>. Apparatus <NUM> includes a coating arm (not shown) that translates within working chamber <NUM> to deposit layers of material M powder along a planar surface <NUM> of plate <NUM>. In some embodiments, the coating arm includes a blade that executes a displacement motion to sweep and/or deposit material M powder across distal face <NUM> and surface <NUM>. In some embodiments, material M is introduced over the entire cross section of working chamber <NUM>. Material M is leveled by the blade to a uniform and/or consistent thickness according to the selected configuration parameters, as described herein. In some embodiments, a powder bed is formed around portion <NUM> by excess powder accumulated during manufacture of each layer of portion <NUM>. In some embodiments, the powder bed is configured as a support material during fabrication of portion <NUM> as the part being constructed is surrounded by un-sintered powder at all times. In some embodiments, material M may include, such as, for example, stainless steel, titanium, cobalt-chromium, polymers, silicone, biologics and/or tissue. In some embodiments, a layer volume of material M powder may be, such as, for example, <NUM>×<NUM>×<NUM>. In some embodiments, a cartridge-type supply/collection system for material M is provided to facilitate powder delivery and recycling.

Laser device <NUM> focuses a laser beam to a layer M1 of material M powder disposed with surface <NUM>, as shown in <FIG>. Laser device <NUM> heats, melts and/or softens layer M1 to selectively heat material M powder according to instructions received from the computer and processor based on the digital rendering and/or data of the selected configuration to produce a layer of portion <NUM>, as shown in <FIG>. Laser device <NUM> articulates relative to plate <NUM> such that the supplied beam is focused on the selected portions of material M deposited on distal face <NUM>. The beam is focused onto portions of material M on distal face <NUM> to melt or sinter material M into a desired shape based on the selected configuration parameters. Platform <NUM> moves plate <NUM> relative to enclosure <NUM>, as described herein, for example, vertically downward to translate portion <NUM> during fabrication of the successive layers of portion <NUM> according to instructions received from the computer and processor.

After one layer of portion <NUM> is melted, plate <NUM> and the fabricated layer of portion <NUM> is translated vertically downward to align the fabricated layer such that the blade moves across surface <NUM> to sweep and/or deposit another layer M2 of material M powder across the prior fabricated layer on distal face <NUM> and plate <NUM> for melting, as shown in <FIG>. Layer M2 is leveled by the blade to a thickness according to the selected configuration parameters, as described herein. Laser device <NUM> heats, melts and/or softens layer M2 to selectively heat material M powder to produce a successive layer of portion <NUM> according to instructions received from the computer and processor.

Portion <NUM> is built up layer by layer and the melting process is repeated slice by slice, layer by layer, until the final layer of material M is melted and portion <NUM> is complete, as shown in <FIG>. Portion <NUM> is formed on distal face <NUM> to extend between an end <NUM> and end <NUM> according to instructions received from the computer and processor, and end <NUM> is fused with surface <NUM>. End <NUM> includes a distal tip <NUM>. In some embodiments, material M is subjected to direct metal laser sintering (DMLS®), selective laser sintering (SLS), fused deposition modeling (FDM), or fused filament fabrication (FFF), or stereolithography (SLA).

Portion <NUM> is fabricated according to instructions received from the computer and processor based on the digital rendering and/or data of the selected configuration, via the additive manufacturing process described herein to include a thread <NUM> that extends between end <NUM> and distal tip <NUM>. Thread <NUM> is formed layer by layer by fabrication of portion <NUM>, as described herein. Thread <NUM> is fabricated to extend along all or a portion of portion <NUM>. In some embodiments, thread <NUM> is fabricated to include a fine, closely-spaced and/or shallow configuration to facilitate and/or enhance engagement with tissue. In some embodiments, thread <NUM> is fabricated to include a greater pitch and an increased lead between thread turns than thread <NUM>, as shown in <FIG>. In some embodiments, thread <NUM> is fabricated to include a smaller pitch or more thread turns per axial distance than thread <NUM> to provide a stronger fixation with tissue and/or resist loosening from tissue. In some embodiments, thread <NUM> is fabricated to be continuous along portion <NUM>. In some embodiments, thread <NUM> is fabricated to be continuous along portion <NUM>. In some embodiments, thread <NUM> is fabricated to be intermittent, staggered, discontinuous and/or may include a single thread turn or a plurality of discrete threads. In some embodiments, portion <NUM> is fabricated to include penetrating elements, such as, for example, a nail configuration, barbs, expanding elements, raised elements, ribs, and/or spikes. In some embodiments, thread <NUM> is fabricated to be self-tapping or intermittent at distal tip <NUM>. In some embodiments, distal tip <NUM> may be rounded. In some embodiments, distal tip <NUM> may be self-drilling.

Bone fastener <NUM> is disengaged from plate <NUM> upon fabrication of portion <NUM> via an additive manufacturing method, as described herein. For example, portion <NUM> is removed from opening <NUM> of plate <NUM> such that surface <NUM> is unthreaded from surface <NUM>. In some embodiments, portion <NUM> is subjected to a finishing process, such as, for example, laser marking, tumble blasting, bead blasting, micro blasting and/or powder blasting. In some embodiments, the additive manufacturing method may include a <NUM>-D printing head. In some embodiments, the additive manufacturing method may include a temperature control unit such as, for example, a heating or cooling unit to control a temperature of distal face <NUM>. In some embodiments, the computer and processor provide instructions for coordination of simultaneous and/or ordered movement of plate <NUM>, distal face <NUM>, laser device <NUM>, components of apparatus <NUM> and/or introduction and layering of material M powder.

In some embodiments, portion <NUM> is fabricated in a configuration having a porosity P via the additive manufacturing method, as described herein. In some embodiments, portion <NUM> is fabricated having a porosity P with a porogen that is spheroidal, cuboidal, rectangular, elongated, tubular, fibrous, disc-shaped, platelet-shaped, polygonal or a mixture thereof. In some embodiments, a porosity of portion <NUM> is based on a plurality of macropores, micropores, nanopores structures and/or a combination thereof.

In some embodiments, the porogen is configured to diffuse, dissolve, and/or degrade after implantation into portion <NUM> leaving a pore. The porogen may be a gas (e.g., carbon dioxide, nitrogen, argon or air), liquid (e.g., water, blood lymph, plasma, serum or marrow), or solid (e.g., crystalline salt, sugar). The porogen may be a watersoluble chemical compound such as a carbohydrate (e.g., polydextrose, dextran), salt, polymer (e.g., polyvinyl pyrrolidone), protein (e.g., gelatin), pharmaceutical agent (e.g., antibiotics), or a small molecule. In other aspects, the porous implant includes as a porogen polysaccharides comprising cellulose, starch, amylose, dextran, poly(dextrose), glycogen, poly(vinylpyrollidone), pullulan, poly(glycolide), poly(lactide), and/or poly(lactide-co-glycolide). In other aspects, the useful porogens include without limitaions hydroxyapatite or polyethylene oxide, polylactic acid, polycaprolactone. Peptides, proteins of fifty amino acids or less or a parathyroid hormone are also useful porogens.

In some embodiments, the porous configuration of portion <NUM> can exhibit high degrees of porosity over a wide range of effective pore sizes. In some embodiments, the porous configuration of portion <NUM> may have, at once, macroporosity, mesoporosity, microporosity and nanoporosity. Macroporosity is characterized by pore diameters greater than about <NUM> microns. Mesoporosity is characterized by pore diameters between about <NUM> microns about <NUM> microns; and microporosity occurs when pores have diameters below about <NUM> microns. Microporous implants have pores of diameters below <NUM> microns, <NUM> microns, <NUM> microns, <NUM> microns, <NUM> microns, <NUM> microns, <NUM> microns, <NUM> microns, and 1micron. Nanoporosity of nanopores is characterized by pore diameters of about <NUM> and below.

In some embodiments, portion <NUM> is fabricated with a material having a porosity P that is created by an additive manufacturing method, as described herein, of a polymer material, for example, a polymer, onto a bed of particles which are not soluble in the polymer and which can be subsequently leached by a non-solvent for the polymer. In this case, the polymer which forms portion <NUM> is printed onto a bed of particles such as salt, sugar, or polyethylene oxide. After the additive manufacturing method is complete, portion <NUM> is removed from the powder bed and placed in a non-solvent for the implant material which will dissolve the particles. For example, polylactic acid in chloroform could be <NUM>-D printed onto a bed of sugar particles, and the sugar can subsequently be leached with water.

In some embodiments, portion <NUM> is fabricated with a material having a porosity P that is created by an additive manufacturing method, as described herein, by printing a solution containing an implant material onto a heated bed of polymer. An example is <NUM>-D printing polylactic acid in chloroform onto a bed of PLA particles heated to <NUM>° C. The boiling point of chloroform is <NUM>° C, and it will thus boil on hitting the particle bed, causing a foam to form. This method of creating porosity is similar to <NUM>-D printing a solution containing the implant material onto a bed containing a foaming agent, which is another way of achieving porosity.

In some embodiments, bone fastener <NUM> includes an implant receiver (not shown) connectable with head <NUM>. In some embodiments, bone fastener <NUM> can include various configurations, such as, for example, a posted screw, a pedicle screw, a bolt, a bone screw for a lateral plate, an interbody screw, a uni-axial screw, a fixed angle screw, a multi-axial screw, a side loading screw, a sagittal adjusting screw, a transverse sagittal adjusting screw, an awl tip, a dual rod multi-axial screw, midline lumbar fusion screw and/or a sacral bone screw. In some embodiments, the implant receiver can be attached by manual engagement and/or non-instrumented assembly, which may include a practitioner, surgeon and/or medical staff grasping the implant receiver and shaft <NUM> and forcibly snap or pop fitting the components together. In some embodiments, spinal implant system <NUM> comprises a kit including a plurality of bone fasteners <NUM> of varying configuration, as described herein. In some embodiments, bone fastener <NUM> is selected from the kit and employed with a treatment at the surgical site.

In one embodiment, as shown in <FIG>, portion <NUM> is fabricated with an additive manufacturing method, as described herein, to define a passageway <NUM> such that portion <NUM> includes a cannulated configuration and a plurality of lateral fenestrations <NUM> in communication with passageway <NUM>. In some embodiments, portion <NUM> may be fabricated with a traditional manufacturing method, as described herein, to similarly define a portion of passageway <NUM> and fenestrations in communication with passageway <NUM>. According to the invention, as shown in <FIG>, portion <NUM> is fabricated with an additive manufacturing method, as described herein, to include an expanding barb <NUM> having rotatable arms <NUM> that pivot outwardly to facilitate engagement with tissue.

Claim 1:
A bone fastener (<NUM>) comprising:
a screw shaft (<NUM>) including a proximal portion (<NUM>) and a distal portion (<NUM>),
the proximal portion (<NUM>) being formed by a first manufacturing method and defining a distal face (<NUM>),
the distal portion (<NUM>) being formed onto the distal face (<NUM>) by a second manufacturing method,
wherein the second manufacturing method includes an additive manufacturing method,
wherein the first manufacturing method includes cutting, grinding, rolling, forming, molding, casting, forging, extruding and/or cold working, and
wherein the distal portion (<NUM>) is fabricated with said additive manufacturing method to include an expanding barb (<NUM>) having rotatable arms (<NUM>) configured to pivot outwardly to facilitate engagement with tissue.