Patent Publication Number: US-2021177624-A1

Title: In-situ additive expandable implants

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation in part of U.S. application Ser. No. 16/716,697, filed Dec. 17, 2019, and U.S. application Ser. No. 16/716,771, filed Dec. 17, 2019, and U.S. application Ser. No. 16/907,341, filed Jun. 22, 2020. The contents of each are herein incorporated in their entireties. 
    
    
     FIELD 
     The present technology is related generally to additive-manufacturing systems and processes for forming patient implants in-situ. 
     BACKGROUND 
     Additive-manufacturing processes have been used increasingly to make a wide variety of parts, including medical implants. An example implant is a spinal interbody, or cage. 
     Advances in additive-manufacturing technology and material science have expanded the types and configurations of parts that can be printed, including parts having internal or otherwise intricate features that were not possible before. 
     Conventional additively-manufactured implants may have various shortcomings. 
     Some of the shortcomings may relate to the fact that they are typically pre-manufactured in mass quantities. They are thus not customized, specific to particular patient anatomy, for instance. They are, rather, one-size/shape fits many. 
     Some product lines offer multiple size options. Even so, product geometry may still be somewhat generic. 
     As another shortcoming, conventional parts can be difficult or impossible to implant because of access issues. There may be patient tissue partially blocking the implant from being delivered to the target implant position. Other access related issues may occur from collapsed or partially collapsed adjacent vertebrae that block access to the area between the adjacent vertebrae. 
     As yet another shortcoming, there are undesirable costs related to off-site manufacture. These include cost of packaging, shipping, tracking, storage, and retrieving and preparing for implantation. 
     In some medical procedures, multiple parts may be implanted. In some of these cases, the parts are connected prior to or during surgery to form a construct. In some conventional spinal surgeries, for instance, a construct of pre-manufactured components is assembled to fix adjacent patient vertebrae together, to limit relative movement between the vertebrae. Fixing relative position between select vertebrae alleviates or obviates implications such as nerve impingement or problematic intervertebral contact. Such implications can result from trauma or the intervertebral disc being compromised. The fixation can also cause adjacent vertebrae to fuse, or grow, together. 
     In addition to the mentioned potential shortcomings of pre-made implants, shortcomings specific to implant assemblies may include additional labor associated with fitting and connecting components manually. 
     And no matter the type of conventional implant, there may be a challenge ensuring precise positioning in the patient. 
     A particular challenge with installing mechanically operated expandable implants exists in those situations in which adjacent vertebra of a patient may be collapsed, partially collapsed, and/or damaged such that conventional expandable implants do not fit between the adjacent vertebrae. In these instances, it is challenging to utilize conventionally available mechanically operated implants. 
     Solutions to the above challenges are desired for spinal surgeries, other medical procedures calling for an implant, and other industries involving some sort of device, whether or not referred to as an implant, including outside of the medical industry. 
     SUMMARY 
     The systems and process of the techniques of this disclosure relate generally to additive-manufacturing systems and processes for forming parts or devices in-situ, such as in a patient during surgery. 
     In one aspect, the present disclosure provides for a method for printing a spinal implant in-situ. The method may include positioning, in a first positioning step, a dispensing component within or adjacent to an interbody access space that provides access to an intervertebral disc space defined by a first vertebra and a second vertebra of a patient. The method may also include printing, in a first printing step, a first cage within or adjacent to the interbody access space. The method may also include positioning, in a second positioning step, the first cage in a first position within the intervertebral disc space and adjacent the interbody access space. The method may also include printing, in a second printing step, a second cage within or adjacent to the interbody access space, and positioning, in a third positioning step, the second cage in a second position within the intervertebral disc space and adjacent the interbody access space. In some embodiments, the third positioning step urges the first cage farther into the intervertebral disc space into a third position, and a size of the first cage corresponds to a size of the interbody access space. 
     In another aspect, the present disclosure provides a method for providing an additive-manufacturing system including a robotic subsystem and a controller apparatus having a processor and a non-transitory computer-readable medium storing in-situ-forming instructions, and executing in-situ-forming instructions, to control the robotic subsystem to perform the positioning and printing steps. 
     In another aspect, the present disclosure provides for an additive-manufacturing system further including a provisioning component affecting flow of printing material to or through the dispensing component, and a controller apparatus, in the printing step, controls the provisioning component based on dispensing-component movement data to control a rate at which the printing material is dispensed. 
     In another aspect, the present disclosure provides, each printing step may include depositing a first layer of a first type of printing material and depositing a second layer of a second type of printing material on the first layer. 
     In another aspect, the present disclosure provides, the first cage is wedge-shaped, and, in the third positioning step, the second cage urges the first cage against the first vertebra to adjust an angle of inclination between the first vertebra and the second vertebra. 
     In another aspect, the present disclosure provides a method for printing, in a third printing step, a third cage within or adjacent to the interbody access space, and positioning, in a fourth positioning step, the third cage in a fourth position within the intervertebral disc space and adjacent the interbody access space. In some embodiments, the fourth positioning step urges the first and second cages farther into the intervertebral disc space, and the intervertebral disc space is substantially filled by the first, second, and third cages. 
     In another aspect, the present disclosure provides that in some embodiments the second cage is wedge-shaped, and, in the third positioning step, the second cage urges the first vertebra and second vertebra away from one another to adjust an angle of inclination between the first vertebra and the second vertebra. 
     In another aspect, the present disclosure provides a method for printing, in a third printing step, a third cage within or adjacent to the interbody access space, and positioning, in a fourth positioning step, the third cage in a fourth position within the intervertebral disc space and adjacent the interbody access space. Additionally, in some embodiments the fourth positioning step urges the first and second cages farther into the intervertebral disc space, and the intervertebral disc space is substantially filled by the first, second, and third cages. 
     In another aspect, the present disclosure provides that in some embodiments the third cage is wedge-shaped, and, in the fourth positioning step, the third and second cages urge the first vertebra and second vertebra farther away from one another to further adjust the angle of inclination between the first vertebra and the second vertebra. 
     In another aspect, the present disclosure provides a method for removing the first cage from the intervertebral disc space, and printing, in a third printing step, a third cage within or adjacent to the interbody access space. The method may further include positioning, in a fourth positioning step, the third cage in a fourth position within the intervertebral disc space and adjacent the interbody access space. In some embodiments, the fourth positioning step urges the second cage farther into the intervertebral disc space, and the intervertebral disc space is substantially filled by the second and third cages. 
     In another aspect, the present disclosure provides a spinal implant formed in-situ, within a patient, using a surgical additive-manufacturing system having a dispensing component and configured to form a plurality of cages. The surgical additive-manufacturing system may include a first cage formed by the dispensing component and having a size corresponding to an interbody access space, and a second cage formed by the dispensing component and having a size corresponding to the interbody access space. In some embodiments, the first cage and second cage substantially fill an intervertebral disc space of the patient defined by a first vertebra and a second vertebra. 
     In another aspect, the present disclosure provides that in some embodiments at least one of the first and second cages is wedge-shaped and configured to increase a spacing between the first vertebra and the second vertebra. 
     In another aspect, the present disclosure provides that in some embodiments, at least one of the first and second cages is wedge-shaped and configured to adjust an angle of inclination between the first vertebra and the second vertebra. 
     In another aspect, the present disclosure provides that in some embodiments, a third cage may be formed by the dispensing component and having a size corresponding to the interbody access space, and the first cage is a sacrificial cage formed of a flexible material and configured to be removed and the second and third cages are formed of a rigid material, and the intervertebral disc space is substantially filled by the second, and third cages after the first cage is removed. 
     In another aspect, the present disclosure provides an additive-manufacturing system for printing spinal implants in-situ, within a patient. The additive-manufacturing system may include a robotic subsystem including scanning and imaging equipment configured to scan a patient&#39;s anatomy, and an armature including a dispensing component configured to dispense at least one printing material. The additive-manufacturing system may further include a controller apparatus having a processor and a non-transitory computer-readable medium storing computer-executable instructions configured to, when executed by the processor, cause the controller to control the scanning and imaging equipment to determine a target alignment of a patients spine, and develop in-situ-forming instructions including an in-situ relocation plan based on the target alignment of the patients spine, an interbody access space, and a disc space between adjacent vertebra of the patients spine. The controller may also execute the in-situ-forming instructions to control the armature to dispense the at least one printing material to form at least one interbody cage, the at least one interbody cage corresponding to the interbody access space, and control the armature to position and/or reposition the at least one interbody cage within the disc space. 
     In another aspect, the present disclosure provides that in some embodiments, a provisioning component for affecting a rate of flow of printing material and a type of printing material through the dispensing component may be provided and the controller may be further configured to control the provisioning component on the basis of the in-situ forming instructions. 
     In another aspect, the present disclosure provides that in some embodiments, computer-executable instructions are further configured to, when executed by the processor, cause the controller to form the at least one interbody cage from a plurality of different printing materials. 
     In another aspect, the present disclosure provides that the computer-executable instructions are further configured to, when executed by the processor, cause the controller to form a first interbody cage and a second cage configured to substantially fill the disc space. 
     In another aspect, the present disclosure provides that the computer-executable instructions are further configured to, when executed by the processor, cause the controller to form a first interbody cage and a second interbody cage that are configured to adjust the disc space to correspond with the target alignment. 
     In another aspect, the present disclosure provides that the computer-executable instructions are further configured to, when executed by the processor, cause the controller to form a first interbody cage, a second interbody cage, and a third interbody cage. In some embodiments, the first interbody cage is formed of a flexible material and the second and third interbody cages are formed of a rigid material and the controller is further configured to control the armature to remove the first interbody cage from the disc space after the armature initially positions the first interbody cage within the disc space, and the second and third interbody cages are configured to substantially fill the disc space after the armature removes the first interbody cage from the disc space. 
     The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an axial view a dispensing component of a surgical additive-manufacturing system positioned adjacent a patient vertebra according to a general embodiment of the present disclosure. 
         FIG. 2  is an axial view of a multi-dispensing arrangement, in a first, substrate-dispensing mode, of the additive-manufacturing system, positioned adjacent the patient vertebra according to a first exemplary embodiment of the present disclosure. 
         FIG. 3  is an axial view of another multi-dispensing arrangement, in a second, catalyst-dispensing mode, positioned adjacent the patient vertebra according to the first exemplary embodiment. 
         FIG. 4  is an axial view of a multi-dispensing arrangement, in a first, substrate-dispensing, mode, of the additive-manufacturing system, positioned adjacent the patient vertebra according to a second exemplary embodiment of the present disclosure. 
         FIG. 5  is an axial view of the multi-dispensing arrangement, in a second, catalyst-dispensing, mode, positioned adjacent the patient vertebra according to the second exemplary embodiment. 
         FIG. 6  is an axial view of a multi-dispensing arrangement of the additive-manufacturing system, in a first, substrate-dispensing, mode, depositing substrate material to the patient vertebra according to a third exemplary embodiment of the present disclosure. 
         FIG. 7  is an axial view of the multi-dispensing arrangement, intra-transitional from the first mode to a second, catalyst-dispensing, mode, adjacent the patient vertebra according to the third exemplary embodiment. 
         FIG. 8  is an axial view of the multi-dispensing arrangement, transitioned to in the second, catalyst-dispensing mode. 
         FIG. 9  is an axial view of the multi-dispensing arrangement, in the second, catalyst-dispensing, mode, depositing catalyst to the patient vertebra according to the third exemplary embodiment. 
         FIG. 10  is perspective view of the additive-manufacturing system positioned in theater for use with the patient. 
         FIG. 11  is the axial view of  FIG. 1  with the dispensing component of the additive-manufacturing system being moved toward an in-situ position of the patient. 
         FIG. 12  is the axial view of  FIG. 1  with the dispensing component moved to an example in-situ position of the patient according to a first general embodiment of the present technology. 
         FIG. 13  shows commencement of in-situ formation of a first interbody implant, by the dispensing component, dispensing a first row of a first, substrate, material, to the in-situ position of the patient according to the first general embodiment of the present technology. 
         FIG. 14  shows the dispensing component continuing to dispense the substrate material to the in-situ position of the patient according to the first general embodiment of the present technology. 
         FIG. 15  shows the dispensing component completing depositing of a first row of substrate material at the in-situ position of the patient according to the first general embodiment of the present technology. 
         FIG. 16  shows the example dispensing component dispensing catalyst, over or to the first-row substrate material at the in-situ position of the patient according to the first general embodiment of the present technology. 
         FIG. 17  shows the dispensing component completing the first row of catalyst over the first-row substrate at the in-situ position of the patient according to the first general embodiment of the present technology. 
         FIG. 18  shows the dispensing component dispensing a subsequent row of substrate material to the in-situ position of the patient according to the first general embodiment of the present technology. 
         FIG. 19  shows the dispensing component completing deposit of the subsequent row of substrate material at the in-situ position of the patient according to the first general embodiment of the present technology. 
         FIG. 20  shows the dispensing component depositing catalyst over the subsequent-row substrate material at the in-situ position of the patient according to the first general embodiment of the present technology. 
         FIG. 21  shows an example first layer of the additive in-situ implant completed according to the first general embodiment of the present technology. 
         FIG. 22  shows the dispensing component beginning formation of a subsequent layer of substrate material over the first layer at the in-situ position of the patient according to the first general embodiment of the present technology. 
         FIG. 23  is a lateral view of the first additive in-situ implant formed in-situ adjacent the first patient vertebra and a second, adjacent, vertebra. 
         FIG. 24  is a perspective view showing the dispensing component in another in-situ position according to a second general embodiment of the present technology, which can be effected following execution of the first general embodiment. 
         FIG. 25  shows commencement of in-situ formation of second, additional, additive implant, in the form of an inter-vertebrae plate, at a second in-situ position connected to the first additive in-situ implant, and at the second vertebra of the patient according to the second general embodiment of the present technology. 
         FIG. 26  shows continuation of forming the second additive in-situ implant, including forming the second implant around and in contact with a first bone anchor pre-secured to the second vertebra of the patient according to the second general embodiment of the present technology. 
         FIG. 27  shows continuation of forming the second additive in-situ implant at the second vertebra according to the second general embodiment of the present technology. 
         FIG. 28  shows completing of the second additive in-situ implant at the first vertebra of the patient, including forming the second implant around and in contact with a second bone anchor pre-secured to the first vertebra of the patient according to the second general embodiment of the present technology. 
         FIG. 29  is a lateral view of the dispensing component of the additive-manufacturing system positioned at an example starting position adjacent patient vertebrae according to a third general embodiment of the present disclosure. 
         FIG. 30  is a lateral view of the dispensing component starting to dispense substrate material between the patient vertebrae according to the third general embodiment of the present disclosure. 
         FIG. 31  is a lateral view of the dispensing component repositioned to generally the starting position for commencing depositing of catalyst according between the patient vertebra according to the third general embodiment. 
         FIG. 32  is a lateral view of the dispensing component dispensing catalyst between the patient vertebra according to the third general embodiment. 
         FIG. 33  is a lateral view of the dispensing component continuing to dispense printing material (e.g., substrate and adhesive) between the patient vertebra for forming the interbody implant in-situ according to the third general embodiment. 
         FIG. 34  is a lateral view of the dispensing component continuing to deposit substrate and catalyst, adjacent the interbody portion and the vertebrae to form a facial plate portion connected to the interbody portion, forming in-situ a combined interbody/plate implant according to the third general embodiment. 
         FIG. 35  is a lateral view of the dispensing component depositing printing material facially to and between the vertebrae forming in-situ a plate implant fixing the vertebrae together, according to a fourth general embodiment of the present technology. 
         FIG. 36  is a side view of two adjacent patient vertebrae spaced such that an illustrated interbody implant cannot be readily passed to a desired inter-vertebral position. 
         FIG. 37  shows commencement of in-situ formation of a sixth interbody implant according to a sixth general embodiment of the present technology. 
         FIG. 38  shows continued in-situ formation of the sixth interbody implant. 
         FIG. 39  shows final in-situ steps for forming the sixth interbody implant. 
         FIG. 40  shows the fourth in-situ-formed interbody completed in the patient according to the sixth general embodiment. 
         FIG. 41  shows commencement of in-situ formation of a first component of a sixth, multi-component, interbody implant according to a sixth general embodiment. 
         FIG. 42  shows commencement of additive formation of a second component of the sixth, multi-component, interbody implant according to the sixth general embodiment. 
         FIG. 43  shows the second component of the sixth embodiment of the interbody implant positioned for insertion to an in-situ position adjacent the first component. 
         FIG. 44  shows the second component interbody implant having been forced to a desired position directly adjacent the first component, forming the sixth exemplary interbody according to the sixth general embodiment. 
         FIG. 45  shows a perspective view of an exemplary fiducial screw according to a seventh general embodiment of the present technology. 
         FIG. 46  shows a lateral view of patient vertebrae to be joined. 
         FIG. 47  shows the lateral view of patient vertebrae, each having a fiducial screw of  FIG. 45  anchored to an anterior, e.g., pedical, portion thereof. 
         FIG. 48  is a lateral view of the dispensing component of the additive-manufacturing system positioned at an example starting position adjacent one of the fiducial screws, or at least adjacent one of the patient vertebrae, for commencing depositing printing material for growing a fusion implant in-situ, according to the seventh general embodiment of the present disclosure. 
         FIG. 49  is a lateral view of the dispensing component of the additive-manufacturing system applying substrate material between the vertebrae for in-situ printing the implant, connecting the screws and thereby the vertebrae, according to the seventh general embodiment of the present disclosure. 
         FIG. 50  is a lateral view of the dispensing component of the additive-manufacturing system repositioned to the starting position for applying substrate material between the vertebrae, connecting the screws and thereby the vertebrae, according to the seventh general embodiment of the present disclosure. 
         FIG. 51  is a lateral view of the dispensing component of the additive-manufacturing system applying catalyst, connecting the screws and thereby the vertebrae, according to the seventh general embodiment of the present disclosure. 
         FIG. 52  is a lateral view of the dispensing component of the additive-manufacturing system completing application of printing material, connecting the screws and thereby the vertebrae, to form the in-situ implant, according to the seventh general embodiment of the present disclosure. 
         FIG. 53  shows an oblique perspective view of the printed in-situ implant, connecting the vertebrae, according to the seventh general embodiment of the present disclosure. 
         FIG. 54  shows a lateral view of patient vertebrae to be supported and/or manipulated by an in-situ printed expandable cage. 
         FIG. 55  shows a lateral view of patient vertebrae to be supported by an in-situ printed expandable cage after being manipulated. 
         FIG. 56  is an axial view of a first in-situ printed expandable cage. 
         FIG. 57  is an axial view of the first in-situ printed expandable cage of  FIG. 56  being repositioned in a disc space. 
         FIG. 58  is an axial view of the first in-situ printed expandable cage of  FIG. 57  and a second in-situ printed expandable cage. 
         FIG. 59  is an axial view of the first and second in-situ printed expandable cages of  FIG. 58  after being repositioned in a disc space and a third in-situ printed expandable cage. 
         FIG. 60  is an axial view of a first in-situ printed expandable cage. 
         FIG. 61  is an axial view of the first in-situ printed expandable cage of  FIG. 60  and a second in-situ printed expandable cage. 
         FIG. 62  is an axial view of the first and second in-situ printed expandable cages of  FIG. 61  being repositioned in a disc space. 
         FIG. 63  is an axial view of the first and second in-situ printed expandable cages of  FIG. 62  and a third in-situ printed expandable cage being repositioned in a disc space. 
         FIG. 64  is an axial view a first flexible in-situ printed expandable cage and second and third rigid in-situ printed expandable cages. 
         FIG. 65  is an axial view of a first portion of the first flexible in-situ printed expandable cage of  FIG. 64  being removed through a contralateral opening. 
         FIG. 66  is an axial view of a second portion of the first flexible in-situ printed expandable cage of  FIG. 64  being removed through a contralateral opening. 
         FIG. 67  is an axial view of a third portion of the first flexible in-situ printed expandable cage of  FIG. 64  being removed through a contralateral opening. 
         FIG. 68  is an axial view after the first flexible in-situ printed expandable cage has been completely removed, a third rigid in-situ printed expandable cage has been printed, and the first, second, and third rigid in-situ printed expandable cages have been repositioned in a disc space. 
         FIG. 69  is a posterior view of a pair of adjacent vertebrae and two pairs of in-situ printed expandable cages in a first position. 
         FIG. 70  is a posterior view of the embodiment of  FIG. 69  after the pair of adjacent vertebrae and the two pairs of in-situ printed expandable cages are moved to a second position thereby opening the disc space. 
         FIG. 71  is a posterior view of the embodiment of  FIG. 70  after an additional in-situ printed expandable cage is formed in the opening of the disc space. 
         FIG. 72  is a posterior view of the embodiment of  FIG. 69  after the pair of adjacent vertebrae and the two pairs of in-situ printed expandable cages are moved to third position thereby opening the disc space and adjusting an angle of inclination between the adjacent vertebrae in the coronal plane. 
         FIG. 73  is a posterior view of the embodiment of  FIG. 72  after an additional in-situ printed expandable cage is formed in the opening of the disc space. 
     
    
    
     DETAILED DESCRIPTION 
     While the present technology is described primarily in the context of spinal implants, the technology is not limited to use with spinal surgery, or even to use for medical procedures. The technology can be used for making devices, whether referred to as implants, for other industries, such as construction or automotive, for instance. 
     Descriptions provided herein regarding medical procedures can, thus, be analogized to the other industries. The descriptions are thus to be understood to include inherently disclosure of such other analogous implementations. Descriptions herein of printing a unique component between or adjacent two vertebrae, in ways that cannot be done with a conventional fully pre-made spinal implant—due to access, fit, or geometry challenges, for instance—thus include thereby disclosure of analogous processes for printing non-medical implants at least partially in-situ, for overcoming the similar access, fit, or geometry challenges. The technology can be used readily to connect more than two vertebra (a single-level procedure), in a multi-level procedure connecting any number of vertebra. 
     As another example of analogous interpretation, of disclosure from spinal procedures to other medical procedures and other-industry procedures, elimination of fiscal or labor costs described in connection with spinal- or medical-industry implementation relates to fiscal or labor savings achievable in any other industry in which the technology can be used. 
     Spinal implants are often used to fix together two or more adjacent vertebrae. Fixing relative position between select vertebrae alleviates or obviates implications such as nerve impingement or problematic intervertebral contact. Such implications can result from trauma or the intervertebral disc having become compromised. Though fusing vertebrae together limits patient flexibility, fixing relative position between select vertebrae promotes continued alleviation of said implications. 
     Benefits from using the technology include the ability to custom-make implants, such as spinal implants, that are particular to a subject-patient anatomy. Benefits also include the ability to make patient-specific implants having geometries that are otherwise impossible or prohibitive to make. 
     Advantageous geometries from growing implants in-situ according to the present technology include those that can realize a specific desired final positioning in the patient. These advantages include advantages stemming from obviating challenges in maneuvering a complete pre-manufactured implant into place in the patient. 
     The advantages include allowing or improving issues relating to access, fit, and part placement, including orientation. Regarding access, for instance, the present technology in many implementations allows printing of implants in spaces having clearance challenges making implantation of conventional pre-made implants difficult, prohibitive, or impossible. Fit advantages include the ability to achieve highly accurate positioning and orientation adjacent the patient, such as between or adjacent patient vertebrae. 
     Benefits from the present technology also include obviating or reducing any of various cost factors, such as cost of packaging, shipping, tracking, storage, and retrieving and preparing for implantation. 
     The present technology can also eliminate some or all manual steps involved with conventional implanting, depending on the implementation of the present disclosure employed. 
     As referenced, benefits from the present technology can also include any of those applicable in other industries. These can include any of those referenced herein for spinal or medical implants, such as the ability to grow custom-fit implants, and various cost savings (obviating part-shipping, storage, and tracking, for instance). 
     Another common benefit between medical and other-industry applications can include access, or the ability to deliver parts to a position or orientation that would be difficult or impossible to get the parts to otherwise. 
     An ability to grow implants in-situ also gives an ability to grow the implants to have more than one material, selected and printed in portions of the implant and with geometries determined best suited to perform in the patient as desired. For example, in-situ grown or formed implants may have varying mechanical properties such as strength, ductility, hardness, flexibility, impact resistance, and fracture toughness. Furthermore, disclosed in-situ expandable cages may be anisotropic in that their material properties may vary with orientation. In some applications, in-situ expandable cages may be isotropic in that their material properties may be the same regardless of orientation. 
     In some embodiments, an additional material grown, formed, or added is a bone-growth-promoting material (BGM). The material can also be injected in-situ into the implant, such as when the implant is only partially grown or formed, and the BGM can best be deposited to desired intra-implant positions. 
     The present technology can be implemented with any of various additive-manufacturing techniques. The selected method would be executed at least partially in-situ, adjacent patient tissue, such as one or more vertebrae. 
     Care, in material preparation (e.g., heating) and in some cases material deposition (e.g., location or timing of depositing) should be taken regarding the temperature to which patient tissue is exposed. 
     Materials that must be at higher temperatures for initial application to the in-situ sight, such as metals, should be used strategically, or a different implementation of the present disclosure should be used. In a contemplated embodiment, a first layer or layers of a cooler powder or liquified material is applied before a layer of hotter liquified material, such as metal, is applied carefully over the first layer, and so not in contact with the patient. The amount of heat that would in this case still transfer, through the first layer, to the patient should be considered. In some implementations, the first material should be sufficiently cooled or solidified before the second is introduced, and in any event have sufficient insulative properties. 
     In some embodiments, material, such as powder, is put in place, by a dispensing element, and then materially altered, such as chemically or by heat. Some materials can be effectively melted by chemical treatment. For these embodiments, care should be taken to ensure that patient tissue is not exposed to undesirable affects, including by not limited to undesirable levels of heat. 
     Any of various printing material can be used, including material that are biocompatible, and materials that effect desired activity in the patient, such as materials promoting bone growth on, through, around, or adjacent the in-situ-grown or formed implant. 
     Regarding additive techniques, generally, any suitable printing method may be used. Suitable printing techniques allow generation of the implant in-situ, at least partially in the patient, without injuring the patient undesirably. Example additive techniques include, generally, Stereolithography (SLA), Digital Light Processing (DLP), Fused deposition Modeling (FDM), Selective Laser Sintering (SLS), Selective Laser Melting (SLM), Electronic Beam Melting (EBM), Laminated Object Manufacturing (LOM), and Binder Jetting (BJ). 
     An example in-situ printing technique is now described. In a powder technique, an implant is built at least partially in the patient by laying down a layer of powder in a desired configuration and location adjacent patient tissue (e.g., a patient vertebra). The powder can include a rigid thermoplastic, such as Poly(methyl methacrylate) (PMMA). This layer can be referred to as a substrate. 
     After the substrate is applied, a catalyst is applied to the substrate. Example catalysts include an adhesive, such as a medical-grade glue, a chemical additive, a curing material, or energy, such as heat, electron beams, radiation. 
     This process of printing layers is repeated in locations and amounts, selectively, to grow the desired implant geometry adjacent the patient tissue. 
     In another technique, beads are used. A dispensing component, such as a nozzle, introduces a layer of beads or particles at desired locations and amounts. The same nozzle, or another dispensing instrument, then applies a catalyst, such as an adhesive, curing additive, or energy (e.g., heat to melt) the beads, to convert the state of the beads, such as hardness, rigidity, flexibility, and shape. 
     In a contemplated embodiment, the nozzle includes an energy-applying element, such as a heating element. 
     A polymer, or other material, having a relatively low melting temperature could be used to avoid injuring tissue. 
     In some, fixed-end, embodiments, the system  100 , including one or more dispensing components  110  and any other desired end effector/s, such as the mentioned heat applicators, are configured so that selected end effectors are fixedly attached (i.e., not readily removable/attachable) to robotics armature. 
     The dispensing component  110  may be referred to by a variety of terms, such as nozzle, dispenser, and applicator. 
     In other, modular, embodiments, the system  100 , including one or more dispensing components  110 , and any one or more other desired end effector, can be configured so that the end effectors can be readily attached to and removed from the robotics armature. The armature and the end effectors have mating features, for selective engaging each other, such as mating threads, tab/slot, other interlocking features, the like, or other. The features are for simplicity in the drawings considered illustrated schematically by reference numeral  111 , which can still be a joint allowing relative articulation between the dispensing component  110  (and/or any other end effector) and arms or armature  112 . The connection nodes  111  and arms  112  can include any number of nodes and arms, though either one or multiple are at times described by way of example herein. 
     Any of the system  100  components can be combined into a kit, in manufacture, or for sale or distribution. 
     To genericize descriptions of the various two-step-printing embodiments for simplicity herein, material or particles first laid on patient tissue are referred to as a substrate at times herein. And energy (e.g., heat), adhesive, chemicals, curing additives, etc., applied on the substrate are referred to generally as a catalyst at times herein. In contemplated embodiments, a single printing material is used, or more than one substrate material and/or more than one catalyst are used. 
     To allow desired post-operation motion in the patient, or to allow only a desired motion or motions, the printing material can include a non-rigid material. The material could be gummy, for instance, to form a motion-sparing, or motion-allowing, implant. 
     Turning now to the drawings, and more particularly to the first figure,  FIG. 1  shows schematically a nozzle or dispensing component  110  of a surgical additive-manufacturing system  100  according to various embodiments of the present technology. 
     The component  110  is shown schematically in axial view adjacent a first patient vertebra  120 . The vertebra includes a body  130  having a cortical rim  140  surrounding a cancellous end plate  150 . 
     The dispensing component  110  can take any suitable shape or form. While the dispensing component  110  is shown schematically as a generally conical nozzle in the drawings, the component in various embodiments has other shapes, such as frustro-conical, cylindrical, tubular, prismatic, needle-like, and a non-descript shape, such as one that is ergonomic or custom-shaped to fit a patient-access. The component  110  can be rigid or flexible, of flexible and rigid in various portions. 
     The dispensing component  110  is connected to upstream components of the system  100  by at least one positioning or control arm  112 . In various embodiments, connecting structure  111 , shown schematically in  FIG. 1 , connects the dispensing component  110  and the control arm  112 . Connecting structure  110  can also connect distinct components of the system armature  112 , as shown by way of example in  FIG. 10 . 
     As described further below in connection with  FIG. 10 , the control arm  112  is actuated to position one or more dispensing components  110  as desired for depositing one or more materials in-situ to select locations in the patient. System movements are in various embodiments controlled by robotics. In contemplated embodiments, any or all control-arm movement can be controlled or assisted manually, such as by a surgeon. 
     In a contemplated embodiment, the system  100  is configured to enable a remotely located surgeon to control aspects of the system  100 . The system  100  can be configured, for instance, to allow the surgeon to, from the remote location, control operative characteristics such as position and orientation of the dispensing component  110 , and material-dispensing rates. For this, the computing components  1060  of the controller  1050  are configured to communicate with actuation controls. The remote actuation controls can include those that are (a) mechanical, such as one or more handles, control sticks, the like or other, (b) automated, such as a computer to (b)(i) present images or other data from the patient-theater controller  1050  to the surgeon, and (b)(ii) transfer data indicative of surgeon movements, from the mechanical actuation controls, to the system controller  1050 , for actuating the on-site system components—e.g., pump/s  1040 , robotics  1030 —accordingly. 
     In various embodiments, any or all such remote componentry is a part of the system  100 . 
     The pumps  1040  may be referred to by any of various terminology, such as a provision component, material-supply component, material supply, material-actuating system or subsystem, the like, or other. 
     The control arm  112  can include a single arm, or multiple arms or sub-parts. The control arm  112  can take any suitable shape or form. While the control arm  112  is shown schematically as generally cylindrical in the drawings, the component in various embodiments can have any suitable shape, and be rigid, flexible, or flexible and in various portions. 
     The dispensing component  110  is in various embodiments configured—size, shape, material, etc.—to enable careful delivery of printing material, such as powder, particles, or a stream or thread of material, such as a gel or other liquid or partially or semi-liquid material. Application of material in consistent layers is desired in some implementations, for example. 
     It is desirable for the dispensing component  110  to be configured to dispense precise amounts of printing material—e.g., substrate and catalyst—to specific locations within the patient. 
     Such features of the technology allow in-situ growing, in-situ printing, or in-situ forming of implants having desired strength, and precise intra-patient positioning and geometry. Proper shape, make-up, and positioning ensure that the implant will function in the patient as desired, for instance, and not impinge on areas of the patient that the implant is not intended for. The dispensing component  110  could, for instance, include at least one strain gauge or other device (not shown in detail) for registering or sensing force at the component  110 . While such sensing device is not shown expressly in the drawings, the dispensing component  110  is considered to by its showing include showing the gauge, as they can be generally or fully designed to be seamless, or otherwise on and/or beneath the surface of the component  110  so as not to adversely affect component  110  movement—e.g., so as not to impinge undesirably with patient tissue or any adjacent surgical instrumentation during the surgical procedure. A computing controller  1050 , described further below, can be adapted to control the nozzle partially based on this nozzle gauge output. 
     When the nozzle (gauge) bumps into surrounding anatomy, in dispensing component approach, positioning movement, or printing movement, the nozzle can be moved accordingly to limit or avoid the bumping. In a contemplated embodiment, the gauge is sensitive to detect objects that the nozzle should not contact, before contact. The nozzle can thus be maneuvered to avoid the contact. This can be referred to as a proximity subsystem, a proximity-avoiding subsystem, or the like. In a contemplated embodiment, the system  100  includes a circuit or switch that adjusts nozzle movement to some extent based on the gauge feedback. In this case, the computing controller  1050  can do less or none of the correction based on gauge feedback. 
     In one embodiment, the gauge(s) is configured and used to facilitate registering patient bone quality and adjusting the implant accordingly. For instance, if the gauge senses weak, or relatively weaker bone material adjacent the dispensing component  110 , the system  100  (e.g., computing controller  1050 ) could apply material accordingly, such as in higher volume or in a special configuration to better address the weakness, such as by a configuration that covers more surface area at, in, or adjacent the weak area. The converse can be true. That is, less material or a special configuration can be used when strong bone is detected, such as by using less material, which can save material and time, and so cost, and be less invasive. Custom inner configuration, such as void or channeling, formed custom to adjacent patient tissue condition is mentioned below. 
     The dispensing component  110  can as mentioned include multiple nozzles or other implements, such as an energy-application element, to accomplish the aims of the present technology. 
     For implementations in which multiple materials are applied adjacent patient tissue, the dispensing component  110  can include (A) an arrangement of multiple corresponding dispensing components  110 , or (B) a single dispensing component  110  by which multiple materials can be dispensed selectively. Three exemplary multi-material-dispensing arrangements are described below in connection with  FIGS. 2-3, 4-5, and 6-9 . Although the arrangements are described as multi-material, the one described as a catalyst can as mentioned be other than a material, such as by being an energy, such as heat, electron beam, or radiation. 
     In various embodiments the first material  220   1  is delivered to the first dispensing component  110   1  via a first transport component, such as a conduit, channel, pipe, or tube. And the second material  220   2  is delivered to the second dispensing component  110   2  via a second transport component. Transport components  210   1 ,  210   2  are indicated schematically in  FIGS. 2-10 . 
     Various conduits, channels, and the like are described herein, such as in connection with nozzles, or dispensing components, system arms, etc. While these various elements are in some cases described separately, such as one in the nozzle connected to one in an adjacent arm, the descriptions are meant to include embodiments in which the two adjacent elements can be a single element, including in the claims. A single channel can be used when two connecting channels, or a channel and a transport component, e.g., are described or claimed. 
       FIG. 2  is an axial view of a first exemplary multi-material-dispensing arrangement  200  having at least two dispensing components  110   1 ,  110   2 . The dispensing components  110   1 ,  110   2  are connected by connecting structure  111 . The connecting structure  111  can include any suitable number of connection points or nodes  111   0 ,  111   1 ,  111   2 . Any of the nodes  111   0 ,  111   1 ,  111   2  may be joints, for instance, about which adjacent structure (nozzle and/or arms) can move relative to each other. 
     An entry node  111   0 , for instance allows an entry arm  112   0  to articulate vis-à-vis first and second delivery arms  112   1 ,  112   2 . Or, vice versa—i.e., allow the arms to be controlled to articulate with respect to the entry arm. A first node  111   2  allows the first delivery arm  112   1  to articulate with respect to the first dispensing component  110   1 , and vice versa. And a second node  111   2  allows the second delivery arm  112   2  to articular with respect to the second dispensing component  110   2 , and vice versa. 
     Components upstream of the dispensing component  110  can be referred to as positioning components. The view of  FIG. 2  shows the multi-material-dispensing arrangement in a first mode, wherein the positioning components (e.g., arms  112   0 ,  112   1 ) are arranged so that the first dispensing element  110   1  is positioned to dispense a first printing material  230  in-situ to the patient, and particularly in this example to, or to and adjacent, the end plate  150  of the first vertebra  120 . 
     The first dispensing component  110   1  receives, via at least one transport component  210   1 , a first in-situ implant-growing material  220   1 . 
     The dispensing component  110   1  is maneuvered, by moving the control arms (e.g., arms  112   0 ,  112   1 ) and any connecting components (e.g., connectors  111   0 ,  111   1 ) in any suitable manner for preparing to dispense, and dispensing, the first material  220   1  as desired. The action is indicated by example arrow in  FIG. 2 . 
     The first material  220   1  can as referenced be referred to as a substrate material for some embodiments. The material may include PMMA or another thermoplastic, and be in power form, as mentioned. In a contemplated embodiment, the substrate material is dispensed in any of various other forms, such as liquid, semi-liquid (e.g., gel), slurry, or another form. 
     In a contemplated embodiment, only the first material  220   1  is applied for the first layer, and the second and subsequent layers include the same. 
     As mentioned, in various embodiments, after the first layer, of the first material  220   1 , is applied, a second layer of a second implant-printing or -growing material  220   2  is applied in-situ, as shown in  FIG. 3 . 
     The second dispensing component  110   2  is maneuvered, by moving the control arms (e.g., arms  112   0 ,  112   2 ) and any connecting components (e.g., connectors  111   0 ,  111   2 ) in any suitable manner for preparing to dispense, and dispensing, the second material  220   2 . The action is indicated by example arrow in  FIG. 3 . 
     Transitioning from using the first dispensing component to the second may in some cases require removing the first dispensing component from the patient to make room for inserting the second component. The same is true in these cases for transitioning from the second to the first dispensing component. 
     In a contemplated embodiments, relevant system components, including the dispensing components especially, are sized, shaped, and connected to other system components (e.g., armature  112 , connector/s  111 ) so that the transition can be effected without removing them from the patient fully, or even without removing the dispensing components from the patient at all. 
     In  FIG. 3 , the second dispensing component  110   2  is shown dispensing the second material  220   2 . The second material  220   2  is applied to or on the first material  220   1 . 
     The second dispensing component  110   2  receives, via at least one transport component  210   2 , the second in-situ implant-growing material  220   2 . 
     The system  100  including upstream source and actuation components (e.g., pumps), selectively push or pull the first and second materials  220   1 ,  220   2  through the dispensing components  110   1 ,  110   2 , selectively Upstream components are described further below in connection with  FIG. 10 . 
     The second material  220   2  can as mentioned be a catalyst. An example catalyst is an adhesive, or glue, but is not limited to these. The catalyst can also include an energy, chemical, additive, or other material causing a reaction such as curing for the first material  220   1 . The nozzle or other implement may be configured to apply heat, electrons, photons, lasers, radiation, the like or other, for instance. 
       FIGS. 4 and 5  show a second example multi-material-dispensing arrangement  400  for providing the substrate and catalyst  220   1 ,  220   2 . The arrangement includes any number of connecting structures to which the dispensing components  110   1 ,  110   2  are connected, such as the example connecting structures shown  111   0 ,  111   3 . 
     As in other embodiments, any number of connection structures can be used, of any size, shape, or material, including flexible and/or rigid. First and second transport components  210   1 ,  210   2  deliver the first and second materials  220   1 ,  220   2  to the dispensing components  110   1 , 110   2 . 
     The system  100  including upstream source and actuation components (e.g., pumps, augers, screws, conveyors, etc.), selectively push or pull the first and second materials  220   1 ,  220   2  through the dispensing components  110   1 ,  110   2 . Upstream components are described further below in connection with  FIG. 10 . 
       FIGS. 6-9  show a third example multi-material-dispensing arrangement  600  for dispensing the first and second materials  230 ,  330 . The arrangement  600  includes any number of connecting structures to which a single dispensing component  110   3  are connected, such as the example connecting structures  111   0 ,  111   4  shown. As in the other embodiments described herein, any suitable or desired number of connection structures can be used, of any size, shape, or material, including flexible and/or rigid. 
     The system  100  including upstream source and actuation components (e.g., pumps), selectively push or pull the first and the second materials  220   1 ,  220   2  through the dispensing component  110   3 , selectively. Upstream components are described further below in connection with  FIG. 10 . 
     In contemplated embodiments, any of the system components—such as connecting components  111 , transport components  210 , or upstream source  1020  or actuation components  1030 —include flow-control components (not shown in detail), such as valves, to regulate which material is fed to or through the dispensing component  110   3 , and in some cases by what amount or rate. 
     In various embodiments, either the first or second material  220   1 ,  220   2  is pushed through the transport components  210  at any one time, forcing that material through and out of the dispensing component  110   3  and into the patient. As one of the materials ( 210   1  or  210   2 ) is pushed through the dispensing component  110   3 , a sufficient amount of the other material ( 210   2  or  210   1 ) residing in the dispensing component  110   3  at the time, is forced out of the dispensing component until the material ( 210   1  or  210   2 ) being pushed begins to be dispensed. 
     In a contemplated embodiment (not shown in detail), the dispensing component  110   3  is configured so that when the system  100  changes from a first-material-dispensing mode to a second, the second material need not displace much or any of the first material. In this case, conduits, channels or tubing of the dispensing component  110   3  extend to or adjacent a tip of the dispensing component  110   3 , keeping the material separate, or substantially separate prior to dispensation from the component  110   3 . 
     In a contemplated embodiment, multiple materials, such as a substrate/catalyst mix, are delivered to the patient via the dispensing component  110   3  at the same time. The two materials can be combined in any of various locations, such as at (i) a facility at which the reservoir/s  1020  are filled, (ii) at the surgical facility prior to surgery—out-of-room, at a back table, or in the surgical theater, (iii) in a reservoir ( 1020  or other) in the system base  1010 , (iv) downstream of the reservoirs  1020   1 ,  1020   2 , such as (iv)(a) within the base  1010  or adjacent and outside of the base  1010 , (iv)(b) in any of the armature  112 , such as in, at, or adjacent the base  1010  or dispensing component  110 , (iv)(c) in any part of the nozzle, or (iv)(d) as dispensed (e.g., at a tip of the nozzle or outside of the tip after the materials are dispensed separately from the nozzle). The reservoirs can be referred to by various terms, such as storage, supply, or source. 
     In another contemplated embodiment, only one suitable implant-forming material is delivered from the dispensing component  110 . In this embodiment, there is not a separate application of substrate and catalyst, for instance. 
       FIGS. 6-9  also show example operation.  FIG. 6  shows the first material  220   1  being dispensed. 
       FIG. 7  shows the first material  220   1  continuing to be dispensed from the dispensing component  110   3 , as the second material  220   2  begins to be pushed through the dispensing component  110   3 . At this point, the actuation causing or pushing the second material  220   2 , is thereby acting on the first material  220   1  positioned still in the dispensing component  110   3 . The first material  220   1  at this point is being forced out dispensing element  110   3  by the force of second material  220   2 , which is being pushed through the dispensing component  110   3 . Example movement of the dispensing component  110   3  is again indicated by arrow. 
     In  FIG. 8 , the second material  220   2  has been pushed to the distal end or tip of the dispensing element  110   3 , so that the second material  220   2  can now be dispense from the dispensing component  110   3 . Example movement of the dispensing component  110   3  is again indicated by arrow. 
     In  FIG. 9 , the second material  220   2  is now being dispensed from the dispensing component  110   3 . 
     Components of the system  100  are now described further in connection with  FIG. 10 . 
     The figure provides a perspective view of the additive-manufacturing system  100  positioned in theater for use with the patient  1000 . 
     The dispensing component  110  extends from control arms or armature  112  and connecting components or nodes  111 . The control arms  112 , connecting components  111 , and dispensing component  110  can be configured (numbered, sized, material, etc.) in any of various ways, including any of the ways described herein, such as in connection with  FIGS. 1-9 . 
     The structure of arms  112  may include, for instance, one or more rigid portions  112   5  and one or more flexible portions  112   6 . The flexible and rigid locations can be positioned anywhere along the armature  112 . While it is contemplated that greater dexterity will be useful closer to the end effector/s ( 110 , etc.), flexible portions can be there, other location/s, or both. 
     Any armature portion may be connected by joints  111 , shown schematically, to adjacent system parts, such as other arms or the dispensing component  110 , as shown in  FIG. 10 , or a system base  1010 . 
     The base  1010  includes at least one reservoir  1020 , for holding the additive printing material  120 . The reservoir  1020  is in various embodiments, whether in the base  1010 , positioned adjacent or close to the end effector. 
     The arms  112  include or are connected to components for maneuvering the dispensing component  110  as needed for in-situ forming the additive implants of the present technology. 
     The control arm/s  112 , connecting component/s  111 , and the dispensing component/s  110  are actuated to desired positions for preparing to dispense and dispensing the implant-growing materials in-situ, to select areas adjacent tissue of the patient  1000 . System movements are in various embodiments controlled by suitable robotics. 
     Robotics can include any suitable actuation and control componentry, is indicated schematically by reference numeral  1030 . 
     In various embodiments, the base  1010  includes some or all of the robotics components, including controlling and actuating subsystems (not shown in detail). 
     The robotics equipment  1030  includes, is connected to, or is a part of the arms  112 , for effecting desired arm movement, such as according to a pre-established surgical plan. The plan may be adjusted real-time based on sensing data, from a sensor with the dispensing component  110  or external to the patient. The sensing data may indicate that patient tissue is shaped or becoming shaped or positioned in a manner that was not anticipated by the plan, for instance. And a system controller, described further below, can be configured (e.g., coded) to thus make necessary adjustments to the plan, with or without surgeon or surgical staff intervention. 
     The robotics equipment  1030  can include or be connected to one or more pumps, indicated schematically by reference numeral  1040 . The pumps  1040  are configured and positioned to push printing material  220   1 ,  220   2  selectively from the reservoirs  1020   1 ,  1020   2 . 
     In a contemplated embodiment, the pump/s  1040 , or additional pumps, are positioned upstream of the base  1010 , such as in the robotics armatures  112 , or in, at, or adjacent the dispensing component  110 . If the upstream pump/s are provided in addition to one or more downstream pumps, the upstream pump/s can be referred to as booster pumps, amplifying pumps, or the like. 
     The robotics equipment  1030  includes or is connected to control componentry, such as computing equipment, indicated by reference numeral  1050  in  FIG. 0.10 . 
     Data communication connection between the controller  1050  and the robotics equipment  1030  and pumps  1040  can be wireless or wired, and is indicated by numeral  1080 . 
     Reference numeral  1060  indicates components of the controller  1050 . These can include any suitable automation, computing, or control componentry. Example components include (i) a communications bus, (i) a memory component storing computer-readable data, or instructions, such an in-situ-forming plan, which may be or include computer-aided-design (CAD) data, and (iii) a processor for receiving and executing the stored data to control and/or receive data from system components, such as the pump  1040  and robotics equipment  1030 . 
     The controller  1050  in various implementations controls and/or receives data from one or more pieces of scanning equipment, any of which is considered a part of the system in some embodiments. 
     The memory component, of the computing components  1060  of the controller  1050 , can be referred to by any of a variety of terms, such as a computer-readable medium, computer-readable subsystem, memory, storage, or storage component, and is in various embodiments non-transitory. The memory component may include any format or componentry, such as random-access memory (RAM) and read-only memory (ROM). 
     The controller  1050  can also include or be configured for ready connection to at least one interface for communication into and/or out of the controller  1050 . The interface is indicated schematically by reference numeral  1070 . The interface  1070  can include any available interface equipment, such as visual or audio input/output equipment, keyboard, etc. Visual input-and/or-output equipment can include a touch-sensitive display, such as a display screen showing an image of a portion of the spine of the patient  1000 , rendered from sensing data, such as from sensing equipment  1093 . In various embodiments, the sensing equipment is a part of or connected to the system  100 . Visual components can include wearable visual components, such as one or more AR or VR components, such as at least one helmet, goggle or glasses, or the like, and are considered shown in the figures by the illustrated indication of i/o equipment  1070 . The sensing equipment, whether part of the AR/BR component, or the illustrated remote sensors  1093 , can sense surgeon movement. The system can also include one or more cameras, or visual sensing devices, such as an on-dispensing-component, on-robotic arm, camera, or other selectively positioned camera/s. The visualization equipment and such visual-sensing equipment can be connected to the controller  1050  such that (i) relevant visuals are provided to the surgeon and (ii) surgeon movements, e.g., hand movements, are translated, via the robotics, into movements or other functions of the dispensing component  110 . In a contemplated embodiment, the controller  1050  can have a limited or no role in any of these functions—the wearable visual component can be connected wirelessly to the source visual sensor/s, for instance. As an example other control that the surgeon can influence in this way, outside of dispensing-component movement, a surgeon moving or squeezing her fingers together, such as toward making a fist, can to the extent of squeezing, affect amount and/or rate of dispensing of printing material  220 . 
     The controller  1050  is communicatively connected with various apparatus by wire or wirelessly, all indicated schematically by reference numeral  1080 . Example apparatus include controlled components, such as the pump/s  1040 , robotics components  1030 , and any other apparatus that communicates with the controller  1050 , such as a scanning or imaging machine  1092 . The imaging machine  1092  may include a separate computing system, as shown at left of the view of  FIG. 10 . 
     In contemplated embodiments, any or all actuations, including those for material pumping ( 1020 ), or armature  112  or dispensing component  110  positioning, can be effected or assisted manually, by surgical staff. 
     For some of the embodiments in which the dispensing component  110  is maneuvered manually, it is contemplated that the system  100  could include an actuator, such as a trigger, or button, or depressible portion of the dispensing component  110  or arm  112 . The actuator, indicated schematically by reference numeral  1085  in  FIG. 10 , can also include or be connected to valves or other structure that can affect material flow as desired. 
     The term provision component can be used generally for any system components affecting the provision of printing material or energy to the dispensing component/s  1050  and in-situ location, such as the pumps  1040 , an actuator  1085  causing material flow, a controllable valve affecting flow, or other suitable provisioning element or apparatus. 
     In various embodiments, the controller  1050  may be configured to control the pumps  1040 . Wherever the pumps  1040  are located (in the base, or downstream thereof, e.g.), and whether the dispensing component  110  is controlled by robotics and/or manually by a surgeon, software (part of the automation components  1060 ) of the controller component  1050  can be configured to actuate pumping—i.e., control printing-material feed timing and/or rate, for instance—based on any of various factors. 
     Example factors include (a) the stage, phase, or time of a pre-established plan that the procedure is in, which plan may be programmed in software of the system controller  1050 , such programming including a computer-aided-design (CAD) file, (b) position or orientation of the dispensing component  110 , and (c) movement of the dispensing component  110 . 
     Regarding the latter factor (c), it may be advantageous, for more-consistent, more-evenly, depositing, for instance, to dispense less printing material (lower-rate provision), or less material per time (rate), when the dispensing component  110  is being moved more slowly (robotically or manually), and more material (higher-rate provision) when the dispensing component  110  is moved more quickly. 
     For embodiments in which material feed rate is based on nozzle movement or position, the system  100  could include position- or motion-sensing componentry providing to the controller  1050  nozzle position or motion-indicating data. Data could also indicate arm  112  position or orientation, from sensors in the arms, connected to the arms, or remote sensors (see e.g., sensor  1093 ) in the room sensing navigation components (see e.g., components  1094 ). The remote features  1093 ,  1094  are described further below. 
     Sensing componentry that is in or connected to the armature or dispensing component  110  can also be considered indicated schematically by reference numeral  1085  for simplicity of the drawings. 
     The controller  1050 , and more particularly the memory of the controller components  1060 , can store a wide variety of data. Example datum include programs, patient identification or anatomy data, in-situ printing plans, machine-learning or artificial-intelligence code, or actual surgical procedure information, such as steps performed, results thereof, sensed features of the patient or printing process, etc. Any of the data, such as the surgical plan, can be partially or fully surgeon-created. 
     The system  100  is configured in various embodiments such that the data can be accessed, or generated, by a user, or another controller or computing system, via the controller interface  1070  or communication connection(s)  1080 . Data can be transmitted from or to the controller  1050  by any suitable hardware or method, such as by wire, Bluetooth, Wi-Fi, portable drive, email, or any available communication technology. 
     In some embodiments, the controller  1050 , by the controller components  1060 , controls patient-positioning equipment, such as a surgical-table control system  1090 . The controller  1050  is connected to the table control system  1090  by wire or wirelessly, both indicated by reference numeral  1091 . 
     In a contemplated embodiment, the table control system  1090  is adjusted at least one time during the surgery, after a first stage of the in-situ printing, for improving positioning, spacing, dynamics, or the like, for a subsequent phase of the in-situ printing. 
     In various embodiments, the patient  1000  can be positioned at an angle with respect to horizontal, such as by tiling the table via the table control system  1090 . Doing so may have a benefit of enabling printing on patient tissue (e.g., vertebral body end plate  150 ) while the tissue is positioned or orientated in an advantageous manner. Example advantageous manners can include, for instance, manners that (a) better allow the dispensing component  110  to fit into or be moved within the patient, (b) control, harness, or take advantage of material characteristics, such as to migrate or run when deposited on an angled surface (e.g., some powder or liquid substrates, before a catalyst is applied), and (c) avoid or harness gravity. 
     As referenced above, the control componentry  1050  in contemplated embodiments controls and/or receives information from sensing equipment to facilitate the in-situ implant printing. Example sensing equipment includes the scanning or imaging machine  1092 . The scanning machine  1092  is positioned to obtain images of the patient in preparation for and/or during the in-situ-printing (ISP) procedure. 
     Pre-procedure scanning can include or be part of a registration process and surgical plan. The registration, surgical planning, and registration and plan storage can be performed by the controller  1050  and/or by other computing devices. 
     The surgical plan can be partially or fully surgeon-created. 
     Scanning data can be used by the controller  1050  to recognize and record desired patient position for the surgery, including position of patient anatomy, including injured or compromised areas. Repeated scannings can be performed—one or more prior to the surgery, typically on a day prior to the surgery, and again to prepare for the surgery, day-off, ensuring that the patient is positioned as desired. The registration can include registration data for the patient in multiple positions for the surgical plan, as mentioned above. 
     As mentioned, the system  100  can include or be used with navigation sensing system  1093 . The navigation sensing system  1093  senses targets  1094  affixed to a navigation instrument  1095 , such as a navigated guide, surgical drill, or bone-screw driver. 
     In various embodiments, any of the nav components  1093 ,  1094 ,  1095  are part of the system  100 . 
     Navigation equipment  1095  can be maneuvered for its purpose by the surgeon  1096  and/or by the controller componentry  1050  and robotics  1030 , based on data received from the navigation sensing system  1093 . Regarding robotic control, the nav instrument  1095  could be an end effector, connected to the armature  112 , of the system  100 , for example. Navigation data is used by the controller  1050  or surgeon for positioning the navigation equipment  1095  precisely as needed to execute a surgical maneuver. 
     The maneuver facilitated can include positioning the dispensing component  110  for printing. The dispensing component  110  or distal armature  112  can include the navigation targets  1094  for this, for instance. 
     Whether navigated, embodiments in which robotics equipment is used for surgical functions, outside of printing functions, can include any related surgical procedures. For spinal surgeries, for instance, the system  100  can include or be connected to instruments for distraction or correction. By distraction, the robotics equipment or surgeon would apply appropriate forces to manipulate vertebral bodies as desired or needed, such as to size or shape the intervertebral space (reference, e.g., the space indicated by  3610  in  FIG. 36 ), or to orient one or more vertebra of the spine otherwise as desired. The distraction using robotics could be used specifically to gain access to the disc space, or for correction after the implant is printed. The robotics could, for instance, move the vertebral bodies such that the printed implant (e.g., cage) doesn&#39;t contact one or both of two adjacent endplates initially, and then move the vertebral body/ies to contact cage. As another example, the implant could be printed with protrusions, such as spikes, such that moving the adjacent vertebral body/ies to contact the implant would drive the protrusions into the vertebral body/ies, promoting implant securement in place. Such ‘positive’ (versus ‘negative’, like holes, channels, etc.) features are describe further below. 
     In various embodiments, the surgeon or robotics  1030  moves or otherwise adjusts the implant after it is formed. 
     Some example procedures will now be described further. 
       FIG. 11  is the axial view of  FIG. 1  with the dispensing component  110  of the additive-manufacturing system  100  being moved toward a desired or pre-planned in-situ printing position of the patient  1000  adjacent the patient vertebral body  130 . Dispensing-component movement, shown schematically by arrow  1100 , is in various embodiments controlled by the controller  1050  and the robotics equipment  1030 . 
     The robust fixation between the implant being grown or formed and patient tissue  120 ,  122 , enabled by printing a patient-shaped implant in-situ, may be enhanced by preparing printing features into or on the implant and/or preparing the tissue in a suitable manner, such as by roughening or grooving. 
     The implant features promoting implant-to-tissue adhesion and/or connection can include surface roughening, surface shaping (e.g., teeth, grooves, channels), and surface coating, or physical features that penetrate patient tissues, such as bony surfaces, e.g., vertebral bodies, or features for attaching post-printing devices such as eyelets for inserting screws. The surface features, whether a level of roughness, smoothness, and/or other features, can be configured to promote or control bone growth on, at, or adjacent the implant, or protect adjacent anatomy. Generally, a rougher surface promotes bone growth, while a smoother surface limits affects on adjacent anatomy. 
     The implant of this embodiment, or any embodiment herein, can also be formed to have geometry promoting any of strength, weight, and bone growth. Regarding the latter, the implant can be formed to have at least one hole, recess, or hollow, partially or fully through the implant, for instance, to promote bone growth into or through the implant. 
       FIG. 12  shows the dispensing component  110  moved to an example in-situ position of the patient  1000  according to a first general embodiment of the present technology. The movement is indicated by arrow  400 . 
     Embodiments are referred to as general because they are agnostic to which particular dispensing-component arrangement is used, such the arrangements  200 ,  400 ,  600  of  FIGS. 2-9 . 
       FIG. 13  shows commencement of in-situ formation of a first interbody implant, by the dispensing component  110 , dispensing a first row of a first, substrate material  220   1 , to the in-situ position of the patient  1000 . 
     The dispensing component  110  can, as described include any of those shown and described herein. The dispenser  110 , applying the first material  220   1 , can be, for instance, any of the first-material dispensing nozzles  110   1 ,  110   3  described with the arrangements  200 ,  400 ,  600 . 
       FIG. 14  shows the dispensing component  110  continuing to dispense the substrate material  110   1  to the in-situ position of the patient  1000 . 
       FIG. 15  shows the dispensing component  110  completing dispensing of a first row of substrate material  220   1  at the in-situ position of the patient  1000 . 
       FIG. 16  shows the dispensing component  110  dispensing a catalyst  220   2  over the first-row substrate material  220   1  at the in-situ position of the patient  1000 . The catalyst can as mentioned include any of various applications, such as adhesive, curing material, or energy such as heat, electron beam, or radiation. 
     The dispensing component  110  can again here include any of those shown and described herein. In the view of  FIG. 16 , the dispenser  110 , applying the second material  220   2  can be, for instance, any of the second-material dispensing nozzles  110   2 ,  110   3  described with the arrangements  200 ,  400 ,  600 . 
       FIG. 17  shows the dispensing component  110  completing the first row of catalyst  220   2  over the first-row substrate  220   1  at the in-situ position of the patient  1000 . 
       FIG. 18  shows the dispensing component  110  dispensing a subsequent row of substrate material  220   1  to the in-situ position of the patient. 
       FIG. 19  shows the dispensing component  110  completing dispensing of the subsequent row of substrate  220   1  at the in-situ position of the patient  1000 . 
       FIG. 20  shows the dispensing component  110  dispensing catalyst  220   2  over the subsequent-row substrate material  220   1  at the in-situ position. 
       FIG. 21  shows an example completed first-layer  2100  of the additive in-situ implant. 
     In various embodiments, the printing does not have to be strictly layer-by-layer. A first layer can be started, then a second, then a third, then addition to the first or second before starting the fourth, as an example. 
     In various embodiments components can be moved, by the system  100  (e.g., dispensing component  110  or another end effector) or surgeon, after being formed, to fit or better fit in a desired intra-patient position. 
       FIG. 22  shows the dispensing component  110  beginning a subsequent layer of substrate material  220   1  over the first completed layer  2100  at the in-situ position of the patient  1000 . 
     The process is continued, layer by layer, or portion by portion, to complete the in-situ-printed spinal implant. The particular sort of implant can be referred to as an in-situ-grown or formed interbody or cage. 
       FIG. 23  is a lateral view of the first in-situ-grown or formed implant  2300  formed adjacent the first patient vertebra  120  and a second, adjacent, vertebra  122 . 
     The implant  2300  is grown or formed in-situ to extend from an anterior, end  2310  to a posterior, end  2320 , and from an inferior end, or base,  2330  to a superior end, or top  2340 . The implant  2300  can be printed in-situ to have any desired configuration (e.g., size, geometry), to accomplish needed bodily adjustment, or tissue-position maintenance, during and after the procedure. In the example shown, the in-situ-grown or formed implant  2300  is created to have a height that tapers generally from a maximum anterior height  10  to a minimum posterior height  12 . 
     The height is in various embodiments tapered in the other direction (down from a maximum posterior end), as shown in  FIG. 23 , not consistently tapered (e.g., tapered in one or more portions, but not across the entirety, and perhaps not in the same directly), or not tapered. Counter tapering (down from a maximum posterior) can be useful, for instance, when the patient anatomy or surgical strategy calls for a larger posterior portion, as shown needed in the case of  FIG. 36 .  FIG. 36  is described further below. 
     In the present embodiment, and for any of the embodiments provided, geometry of the in-situ-grown or formed implant  2300  could have any features beneficial for encouraging bone growth on, through, around, or adjacent the implant. In contemplated embodiments, the material may include or be coated with any beneficial material. Example materials include medicinal material, antibiotic material, and bacteria- or virus-resistant or -fighting materials. Materials could be introduced by the dispensing component  110 , as discussed above, or another nozzle or dispensing component. 
     Implant  2300  geometry may be shaped to avoid any remaining bony structures present, such as may occur in a partial osteotomy procedure. In a contemplated embodiment, the printing material includes material configured to affect patient tissue. 
     Implant  2300  geometry may include features that facilitate surgery, such as those that can be used as drill guides or for anatomical holding. As an example of the latter (anatomical holding), the implant  2300  could be shaped to (a) hold back or move a dura of the patient  1000 , (b) shield exiting nerve roots, or (c) block any blood vessel from being injured in surgery. (dura, roots, and vessels not shown in detail) The facilitating features can be temporary, by being removable after they have served their purpose, which can be prior to an end of the printing steps or any time before an end of the procedure. 
     In various embodiments, the system controller  1050  controls other system  100  components to form an implant having geometry corresponding with patient anatomy. The controller  1050  can do this by, for instance, controlling the robotics  1030  and pumps  1040  to form implant pockets or recesses in the implant being formed. Such features can align with, or be offset from, actual patient anatomy, for instance. This may help avoid or limit unwanted implant/anatomy contact. As another potential benefit, printing the implant to have such anatomy-related, or anatomy-customized, features may allow formation of preferred wall thickness or other sizing for the implant, while still allowing the implant to fit in the desired location within the patient  1000 . 
       FIG. 24  is a perspective view showing the dispensing component  110  in another in-situ position adjacent the vertebrae  120 ,  122  of the patient  1000  according to a second general embodiment. A native intervertebral disc of the patient, between the first vertebra  120  and a further inferior vertebra  2430 , is indicated by reference numeral  2430 . 
     The second general embodiment can include, or be effected following execution of, performance of the steps under the first general embodiment described above in connection with  FIGS. 11-23 . The dispensing component  110  can print the interbody  2300  from a posterior approach and/or an anterior approach. The component  110  can be moved from a completing step of dispensing from a posterior approach, to an anterior approach to commence or continue printing the plate component  2500  ( FIGS. 25-28 ), for instance. 
     In a contemplated embodiment, the interbody between the patient vertebrae  120 ,  122  is not in-situ printed or not fully in-situ printed (see, e.g., the embodiment described below in connection with  FIGS. 41-44 ). The interbody there can be pre-manufactured, at a manufacturing facility, for instance. 
     It should be appreciated that, as with the other in-situ-grown or formed implants described herein, the resulting implant  2300  of this embodiment is highly customized to the patient anatomy, being formed adjacent and on or at patient tissue, including but not limited to the vertebrae  120 ,  122  in primary examples. 
     The implant  2300  of this embodiment, or any embodiment herein, can also include interface features to promote printing-material-to-tissue adhesion and/or connection, and/or strengthen the implant. Example interface features include surface roughening, surface shaping (e.g., teeth), and surface coating, or physical features that penetrate patient tissues, such as bony surfaces, e.g., vertebral bodies, or features for attaching post-printing devices such as eyelets for inserting screws. 
       FIG. 24  shows an implant in place, such as the in-situ-grown or formed interbody of  FIG. 23 . The figure also shows anchoring components  2410 ,  2420  affixed to respective anterior faces of the superior and anterior vertebrae  122 ,  120  of the patient  1000 . An example anchoring component, or anchor, is a bone screw. In some embodiments, the anchors include any type of bone screw used conventionally in spinal surgeries. In a contemplated embodiment, the anchor  2410 ,  2420  is customized to facilitate the implant growing or implant qualities (e.g., shape, strength). 
     In various embodiments, the anchors  2410 ,  2420  are printed in place. The technique includes pre-forming bores in the anterior face of the vertebrae  122 ,  120 , and growing the anchors therein, and therefrom. 
     In one embodiment, the anchors are mechanically driven or forced (i.e., by force, twisting, or the like, versus printing) into the bone, such as by use of a driver instrument. The anchor can be a metal screw, for instance. The anchors can be driven or forced by system components (not shown in detail), such as an anchor driver connected to an end of the robotics armature, with, or in a modular embodiment, as a driver end effector selectively instead of the dispensing component being in this case a readily removable end effector. 
     It is contemplated that boring equipment (not shown in detail) for this purpose can be part of the system  100 . One or more boring end effectors can be attached to the robotics armature, such as an additional effector with the nozzles in the views of  FIGS. 2-9 . Or the boring end effector can be connected to the armature selectively, as can in some embodiments the dispensing componentry, as described above. The boring equipment can be part of the kits mentioned above. For purposes of illustration, the boring equipment, whether modular, is considered illustrated by the end effector  110  of  FIG. 24 . 
       FIG. 25  shows commencement of in-situ formation of second, additional, additive implant, in the form of an inter-vertebrae plate at a second in-situ position connected to the first additive in-situ implant and at the second vertebra of the patient according to the second general embodiment of the present technology. While  FIG. 25  is referenced as a commencement of formation, actual commencement can be earlier, depending on the implementation. If the interbody  2310  is printed first, that printing can be considered the commencement, or if the first in-situ printing involves growing the bone anchors  2410 ,  2420 , that printing can be considered the commencement. 
     The additional in-situ-printed implant formation is indicated by numeral  2500 . The extra-interbody portion can be referred to by any of a variety of terms, such as plate, surface portion, or surface connector. 
     In a contemplated embodiment, the pre-formed or pre-existing implant  2300  includes one or more connecting features at an interface  2510  to which the additional in-situ-printed implant  2300  is formed or connects. The connecting interface  2510  is indicated schematically by lead line in  FIG. 25  at a corner formed between the additional in-situ-printed implant  2500  and the pre-implanted interbody  2300 . The connecting interface  2510  however can be at any one or more location where the additional in-situ-printed implant  2500  is formed in contact with the pre-implanted interbody  2300 . Example interface-feature locations include, for instance, the face  2310  of the interbody  2300 , a front-top edge of the interbody, and a front-bottom edge of the interbody. 
     In various, embodiments, the interbody/plate combination is built in the same surgical procedure, or the combination can be created by printing one of the two in a first procedure and the other in connection with the first in a second surgery, such as on a distinct day, month, or year from the first procedure. 
     The first-built implant (e.g., the interbody  2300 ), can be used as a guide for creating the second (e.g., plate  2500 ) intimately connected to the first and patient tissue (e.g., bone), whether the two are built in the same or distinct surgeries. 
     Interface features  2310  can include any of protrusions, roughening, indentations, grooves, hooks, overhanding or underhanging elements, the like, or other, to facilitate robust connection between the interbody  2300  and the additional in-situ-printed implant  2500  being formed in connection to the interbody  2300 . 
     And as in other embodiments described herein, robust fixation between the interbody portion and the patient tissue  120 ,  122 , and between the plate portion and the patient tissue, from printing in-situ, customized to and directly to patient anatomy, can be enhanced by preparing the tissue as desired, such as by roughening or grooving. 
       FIG. 26  shows continued formation of the second additive in-situ implant  2500 , including forming the second implant around and in contact with the first bone anchor  2410 . The in-situ printing may include any of the techniques described herein, including printing with only one material, or printing with two materials. 
     In one of the mentioned embodiments, in which the bone anchor  2410  is printed, the anchor  2410  can be printed in this step, before or with printing of a body of the adjacent additional in-situ-printed implant  2500 . The same is possible in connection with the second bone anchor  2420 , also shown in  FIG. 26  and described further below in connection with  FIG. 28 . 
       FIG. 27  shows continued formation of the second additive in-situ implant  2500  at the second vertebra  122  of the patient  100  according to the second general embodiment of the present technology. 
       FIG. 28  shows completing steps of forming the second additive in-situ implant  2500  at the first vertebra  120  of the patient  100 , including forming the second implant snuggly around a second bone anchor  2420  affixed to the first vertebra, according to the second general embodiment of the present technology. 
     The system  100  moves and prints the additional in-situ printed implant  2500  in various embodiments to have any desired dimensions—e.g., thickness, height, width, and shape. 
     It should be appreciated that, as with the other in-situ-grown or formed implants described herein, the resulting implant  2500  of this embodiment is highly customized to the patient anatomy, being formed adjacent and on or at patient tissue, including but not limited to the vertebrae  120 ,  122  in this example. 
     The implant  2500  of this embodiment, or any embodiment herein, can also include interface features to promote printing-material-to-tissue adhesion and/or connection, and/or strengthen the implant. Example interface features include surface roughening, surface shaping (e.g., teeth), and surface coating. The interface features can include, for instance, eyelets on the plate for receiving bone anchors (e.g., screws), if not pre-anchored 
       FIGS. 29-33  show another technique for forming an interbody implant by in-situ printing. The implant can also be formed to include a plate portion, as shown in  FIG. 33 . 
     Starting with  FIG. 29 , a lateral view is provided, of the dispensing component  1010  of the additive-manufacturing system  100  positioned at an example starting position adjacent the vertebrae  120 ,  122  of the patient  1000 , according to a third general embodiment of the present disclosure. 
       FIG. 30  shows the dispensing component  110  starting to dispense substrate material  220   1  between the patient vertebrae  120 ,  122  according to the third general embodiment of the present disclosure. 
       FIG. 31  shows the dispensing component  110  repositioned to or adjacent the starting position ( FIG. 29 ) for commencing dispensing of the second, catalyst, material  220   2 , according between the patient vertebrae  120 ,  122  according to the third general embodiment. 
       FIG. 32  shows the dispensing component  110  dispensing catalyst material  220   2  to, on, or at the substrate material  220   1 , between the patient vertebrae  120 ,  122 . 
       FIG. 33  is a lateral view of the dispensing component completing printing of material for forming the in-situ-printed implant  3300 , according to the third general embodiment. 
     It should be appreciated that, as with the other in-situ-grown or formed implants described herein, the resulting implant  3300  of this embodiment is highly customized to the patient anatomy, being formed adjacent and on or at patient tissue, including but not limited to the vertebrae  120 ,  122  in this example. 
       FIG. 34  is a lateral view of the dispensing component  110  continuing to dispense substrate  220   1  and catalyst  220   2 , adjacent the previously in-situ grown or formed interbody  3300 , and adjacent and in contact with the vertebrae  120 ,  122  of the patient  1000  to form a facial-plate portion  3400  connected to the interbody portion  3300 , thereby printing in-situ a combined interbody/plate implant  3410 , according to the third general embodiment. 
     While the term facial is used, the term is not limiting for all embodiments. The extra-interbody portion, formed outside of the interbody space and in connection with an exterior surface of at least two vertebrae. The extra-interbody portion can be referred to by any of a variety of terms, such as plate, surface portion, or surface connector. 
     The plate portion can be referred to by any of a variety of terms, such as plate, surface portion, or surface connector. 
     As in other embodiments described herein, robust fixation between the interbody portion  3300  and the patient tissue  120 ,  122 , and between the plate portion and the patient tissue, from printing in-situ, customized to and directly to patient anatomy, can be enhanced by preparing the tissue as desired, such as by roughening or grooving. 
     And, as also described in connection with other embodiments, herein, either or both of two connecting implants  3300 ,  3400 , or portions  3300 ,  3400  of the implant  3410  can be formed to include interface features  2310 , such as protrusions, roughening, indentations, grooves, hooks, overhanding or underhanging elements, the like, or other, to facilitate robust connection between them. 
     The implant  3400  of this embodiment, or any embodiment herein, can also include interface features to promote printing-material-to-tissue adhesion, and/or strengthen the implant. Example interface features include surface roughening, surface shaping (e.g., teeth), and surface coating, or physical features that penetrate patient tissues, such as bony surfaces, e.g., vertebral bodies, or features for attaching post-printing devices such as eyelets for inserting screws. 
       FIG. 35  is a lateral view of the dispensing component  110  positioned by the robotics  1030  and armature  112  of the system  100  for dispensing. The system  100  by way of the dispensing component  110  deposits printing material (e.g., substrate and catalyst) to, or to and between, faces  3510 ,  3520  of the vertebrae  120 ,  122  forming in-situ a plate implant  3500  fixing the vertebrae together, according to a fourth general embodiment of the present technology. 
     The embodiment can include pre-implantation, or in-situ printing of bone anchors (not shown in  FIG. 35 ) to which the plate implant  3500  is grown or formed. Anchor pre-implantation and printing is described above with the embodiment of  FIG. 26 . 
     It should be appreciated that, as with the other in-situ-grown or formed implants described herein, the resulting implant  3500  of this embodiment is highly customized to the patient anatomy, being formed adjacent and on or at patient tissue, including but not limited to the vertebrae  120 ,  122  in this example. 
     And as in other embodiments described, robust fixation between the between the in-situ-grown or formed plate  3500  and the patient tissue, from printing in-situ, customized to and directly to patient anatomy, can be enhanced by preparing the tissue as desired, such as by roughening or grooving. 
     And the implant  3500  of this embodiment, or any embodiment herein, can also include interface features to promote printing-material-to-tissue adhesion and/or connection, and strengthen the implant. Example interface features include surface roughening, surface shaping (e.g., teeth) and surface coating. 
     Some embodiments address issues related to challenging patient-tissue spacing. Sometimes an entry opening to a target implant region of the patient  100  is too small to fit a pre-made implant through. Various techniques of the present disclosure described above can be used to remedy these situations. As other example solutions,  FIGS. 37-40  show a manner of doing so, and  FIGS. 41-44  shows another. 
     As an example of such fitting challenge,  FIG. 36  shows a side view of the patient vertebrae  120 ,  122  spaced such that a pre-printed or otherwise pre-made interbody implant  3600 , sized for a particular interbody space  3610 , cannot be readily passed to position in the space. Anterior interbody spacing  11 , at an opening  3620 , of the patient  1000  is smaller than an entry height  13  of the implant  3600 . 
     As a first of the mentioned solutions for the challenge presented by context of  FIG. 36 ,  FIG. 37  shows commencement of in-situ formation of a fifth interbody implant  3700  according to a fifth general embodiment of the present technology. 
     The dispensing component  110  is sized, shaped, and maneuvered to easily fit through the anterior opening  3620  of  FIG. 36 , and extend into the inter-tissue space  3610  and to a posterior region  3710  between the vertebrae  120 ,  122 . 
       FIG. 38  shows continued in-situ formation of the fifth interbody implant  3700 , posterior-to-anterior by way of example. 
       FIG. 39  shows final in-situ steps completing for forming the fifth interbody implant  3700 . 
       FIG. 40  shows the in-situ-grown or formed interbody  3700  completed in the patient  1000  according to the fifth general embodiment. 
     As in other embodiments described herein, the robust fixation between the interbody portion and the patient tissue  120 ,  122 , and between the in-situ-grown or formed implant  3700  and the patient tissue  120 ,  122 , from printing in-situ, customized to and directly to patient anatomy, can be enhanced by preparing the tissue as desired, such as by roughening or grooving. 
     It should be appreciated that, as with the other in-situ-grown or formed implants described herein, the resulting implant  3700  of this embodiment is highly customized to the patient anatomy, being formed adjacent and on or at patient tissue, including but not limited to the vertebrae  120 ,  122  in this example. 
     The implant  3700  of this embodiment, or any embodiment herein, can also include interface features to promote printing-material-to-anchor adhesion and/or connection, and strengthen the implant. Example interface features include surface roughening, surface shaping (e.g., teeth), and surface coating, or physical features that penetrate patient tissues, such as bony surfaces, e.g., vertebral bodies, or features for attaching post-printing devices such as eyelets for inserting screws. 
     As another solution to the fit challenges indicated by  FIG. 36 ,  FIG. 41  shows commencement of in-situ formation of a first part  4100  of a multi-component, interbody implant, between the vertebrae  120 ,  122  of the patient  1000 , according to a sixth general embodiment. 
       FIG. 42  shows commencement of additive formation of a second part  4200  of the multi-component interbody implant according to the sixth general embodiment. The formation is shown schematically on a table  4210 , such as a prep table in the surgical room. 
     In a contemplated embodiment, the surface on which the second part is grown or formed includes a patient-tissue surface, such as an exterior of vertebra or other bone. 
     In a contemplated embodiment, the second part  4200  is grown or formed at least partially on the first part  4100 . The connection between the two may be slight in various ways, to allow ready relative movement between the parts after the second part is completed (such as to accomplish a final, combined, implant shape, such as shown in  FIG. 44 ) The slight connection may be from printing only one or more small pieces, such as tabs, on the first part  4100 , and printing the second part on the small pieces. 
     The second part  4200  can then be easily pushed in a posterior direction, breaking the small pieces, the reach the final implant shape. Another example of a slight connection can be from a manner in which the second part is printed on the first, such as after a top layer of the first part has cured or solidified by an amount sufficient to enable the second part printed thereon to be easily moved relative to the first, thereby again allowing the subsequent relative movement. 
     The second part is in various embodiments grown or formed real-time by the system  100 , as shown, or is a pre-manufactured component, whether printed. In various embodiments, the second part  4200  is made to have a size and shape corresponding to size and shape of the first part  4100  and to patient anatomy, namely the vertebrae  120 ,  122 . Likewise, the first part  4100  is made to have a size and shape corresponding to size and shape of the second part  4200 , as well as to the patient anatomy. 
       FIG. 43  shows the second part  4200  of the sixth embodiment of the interbody implant positioned for insertion, adjacent the tissue opening  3620 . 
       FIG. 44  shows the second component  4200  forced to a final position shown in  FIG. 44  adjacent the first part  4100 . The movement may cause the second component  4200  wedge between the first part  4100  and the second vertebra  122 , which may slightly push one or both vertebra away from the other. The forcing causes the second part  4200  to, with the first part, substantially fill the inter-tissue space  3610  of the patient  1000  as desired. This forms the multi-component interbody implant in-situ (being grown or formed at least partially in-situ), according to the sixth general embodiment. 
     In a contemplated embodiment, the system  100  applies or is used to apply the force to move the second part  4200  into place. The dispensing component  110  may be used to apply the force, for instance, by motivation of a surgeon or the robotics  1030  controlled by the system controller  1050 . 
     Spacing between the parts  4100 ,  4200  can have any size or dimension, desired, or the parts can be formed and connected so that there is no, or substantially no, space between them. Spacing may be desired in some cases, such as to allow relative movement between the parts  4100 ,  4200  as the patient moves and heals (e.g., inter-vertebral fusing) after the procedure. 
     Either or both of the parts  4100 ,  4200  can have interface features, indicated schematically (by location) by reference numeral  4410 . Interface features  4410  can include any of protrusions, roughening, indentations, grooves, hooks, overhanding or underhanging elements, the like, or other, to facilitate robust connection between the parts  4100 ,  4400 . 
     As another example, the parts  4100 ,  4200  can include matching features that facilitate accurate relative positioning of the two. Or have matching, or geometrically-corresponding, features promoting connection between the two, such as by one being made to have one or more rails and one having one or more corresponding slots to receive the rails. Or, to promote connection between them, and possible to also provide an indication of proper relative positioning, such as by haptic feedback to the system  100  or surgeon maneuvering the second part  4200  into place adjacent the first part  4100 . 
     In various embodiments the second part  4200  can be pre-manufactured. In some cases, the first part  4100  is structured (sized and shaped, for instance) to accommodate (e.g., receive) the second part  4200 . The first part  4100  may be grown or formed to have a recess, hollow, void, or other spacing, for instance, to which the second part  4200  can be connected and/or into which the second part  4200  can be placed. 
     The first part  4100  can be printed after the second part  4200  is implanted. The first part  4100  can be printed in and/or around. The first part  4100 , and thus the combination, would thus be patient-anatomy optimized. Another benefit of these embodiments can be time savings, and cost savings from time and perhaps labor and material savings. 
     The second part when pre-made per these embodiments can have any desired form, including any existing parts for the same or similar purpose—e.g., existing spinal implants. One or more pre-made parts can be included in a set sold or provided to the surgical team. 
     As in other embodiments described, the robust fixation between the interbody parts  4100 ,  4200  and the patient tissue  120 ,  122 , and between the resulting in-situ-grown or formed implant  4400  and the patient tissue  120 ,  122 , from printing in-situ, customized to and directly to patient anatomy, can be enhanced by preparing the tissue as desired, such as by roughening or grooving. 
     The implant  4400  of this embodiment, or any embodiment herein, can also include interface features to promote printing-material-to-anchor adhesion and/or connection, and strengthen the implant. Example interface features include surface roughening, surface shaping (e.g., teeth), and surface coating, or physical features that penetrate patient tissues, such as bony surfaces, e.g., vertebral bodies, or features for attaching post-printing devices such as eyelets for inserting screws. 
     It should be appreciated that, as with the other in-situ-grown or formed implants described herein, the resulting implant  4400  of this embodiment is highly customized to the patient anatomy, being formed adjacent and on or at patient tissue, including but not limited to the vertebrae  120 ,  122  in this example. 
     Turning to a final, seventh, general embodiment of the present disclosure,  FIG. 45  shows a perspective view of an exemplary fiducial bone anchor implant  4500 , such as a bone screw. 
     The bone anchor  4500  can in various implementations be referred to as a fiducial anchor, or fiducial screw, and a function thereof can include an ability to be visualized readily by scanning or imaging equipment based on a characteristic of the implant. 
     Example recognition characteristics include shape of features. The anchor  4500  can also include detectable features, whether for recognition in the sense used here. These can be visible, or not visible to the eye. Examples include bar codes, QR codes, RFID tags, ultraviolet inks, and surface or embedded markers. Markers can include techno-aide (TA) markers, or others having one or more select materials that look or scan/image in a unique way for anchor identification, anchor or anchor-portion recognition, position determination, or orientation determination. 
     In a contemplated embodiment, the recognition features include a material of the implant. 
     An example of the mentioned scanning or imaging equipment is the surround scanner  1092 , or the navigation system  1093 , of  FIG. 10 . 
     The anchor  4500  includes a head  4510 , a shaft  4520 , and at least one thread  4530  for fixing the implant to bone. The head  4510  includes driving features  4540  in various embodiments. The driving features are configured to be engaged by a driver instrument (not shown). An example driving feature is a hex shape, as shown in  FIG. 45 . 
     Any aspect of the anchor implant  4500  can have the fiducial, readily recognizable characteristic(s). The head  4510  is an example. The head  4510  can have any of a variety of unique, or special, fiducial shapes or geometries for the fiducial purpose. In various embodiments, the head  4510  is generally ball-shaped. 
     When having fiducial characteristics, the head  4510  may be referred to as a fiducial head, or fiducial portion of the anchor  4510 . The fiducial head  4510  is in various embodiments configured (e.g., fiducially shaped) and/or constituted (having fiducial material, e.g.) to promote ready recognition by scanning or imaging equipment, such as the surround scanner  1092 , or the navigation system  1093  sensor. 
     The head shape can be unique, or special, by being distinct from conventional screw head shapes, for instance. And the processor of the controller  1050 , executing the instruction stored in the memory of the computing components  1060 , recognizes the distinct shape in the scan data, and with that the position of the head or anchor. 
     Other portions of the screw, such as the shaft  4520  or the thread  4530  thereon, can also have fiducial features, along with or instead of the head, to be highly fiducial. 
     More particularly, the fiducial head  4510 , or any fiducial component of the anchor  4500 , has a specific geometry that software, of the controller  1050  of the system  100  (see e.g.,  FIG. 10 ) is programmed to recognize in scanner or image data. 
     In the case of the fiducial head  4510 , an example geometry can be, for instance, conical, cubical, or cylindrical—such as by including, e.g., a cylindrical post. 
     As another example fiducial geometry, the implant  4500  can have a fiducial characteristic that is not a primary component of the implant, such as the head, shaft or thread of the implant  4500 . Such characteristic can be temporary, by being removable after they have served their purpose, which can be prior to an end of the printing steps or any time before an end of the procedure. 
     An example add-on fiducial characteristic is a protrusion  4550 . The add-on features can be formed with or added to the implant  4500 , such as by printing by the system, which may also print the entire implant  4500 . The protrusion or other fiducial feature can be configured and/or attached to the implant  4500  to be readily removed during the procedure. Removal can include snapping off or pulling off. While surgical staff can effect the removal, in a contemplated embodiment the controller  1050  is configured to, by the processor executing instruction stored in the controller, maneuver an instrument, such as the dispenser  110 , to remove the fiducial feature. 
     The fiducial implant component, such as the fiducial head  4510 , or fiducial add-on feature, such as the protrusion  4550 , can as mentioned include material especially conducive to visualizing. The material is configured to be especially sensed and/or especially recognized by the scanner/imaging equipment and/or by the software of the controller  1050  receiving the image data. Example scanning techniques include x-ray, MRI, and camera. 
     The fiducial anchor  4500  in various embodiments includes interface features to promote engagement of in-situ printing material (see e.g., numeral  220  in  FIGS. 49-53 ) to the anchor  450 . Interface features can also promote printing-material  220 -to-anchor  450  adhesion and/or connection, and strengthen the anchor  4500 . Example interface features include surface roughening, surface shaping (e.g., teeth), and a surface coating. 
       FIG. 46  shows a lateral view of patient vertebrae  120 ,  122  to be fused. 
       FIG. 47  shows the lateral view with bone anchors  4500  anchored into an anterior, pedical, portion of the vertebrae  120 ,  122 . 
     In various embodiments, the anchors  4500  are printed in place. The technique includes pre-forming bores at the anchor locations of the vertebrae  122 ,  120 , and growing the anchors  4500  therein, and therefrom. 
     In one embodiment, the anchors  4500  are mechanically driven (by threading, twisting, or otherwise forcing the anchor) into the bone, such as by a conventional driver instrument (not shown). 
     The anchor  4500  can be a metal screw, for instance. The anchors are in various embodiments driven in by system components (not shown in detail), such as an anchor driver connected to an end of the robotics armature  112 . The driver end effector, in a modular embodiment, is a driver end effector selectively connected to the armature instead of the dispensing component and is readily removable after use. The desired dispensing end effector  110  is then connected to the armature  112  for the printing steps. 
     It is contemplated that boring equipment (not shown in detail) for this purpose can also be part of the system  100 . One or more boring end effectors can be attached to the robotics armature, such as an additional effector with the nozzles in the views of  FIGS. 2-9 . Or the boring end effector can be connected to the armature selectively as a removable end effector. 
     Such additional equipment (driver and boring equipment), whether modular, is considered illustrated by the end effector  110  shown in  FIG. 24  to simplify the drawings. 
       FIG. 48  is a lateral view of the dispensing component  110  of the additive-manufacturing system  100  positioned at an example starting position adjacent one of the fiducial screws  4500 , or at least adjacent one of the patient vertebrae, for commencing deposit of printing material (e.g., substrate and catalyst) for in-situ printing an implant connecting the vertebrae  120 ,  122 , according to the seventh general embodiment of the present disclosure. 
     The starting position can be determined by the controller  1050  based on anchor positioning determined by recognition of the fiducial characteristic of the anchor indicated in scan or image data taken prior to the dispensing component  110  positioning. The controller  1050  then controls the robotics componentry  1030  to position the dispensing component  110  accordingly. 
     In various embodiments, the controller  1050 , also for determining the starting position, recognizes patient anatomy adjacent the implant location. 
     The controller  1050  may incorporate such fiducial implant and/or patient anatomy information into a pre-established in-situ printing plan, or generate the plan based on fiducial implant and/or patient anatomy information. 
       FIG. 49  is a lateral view of the dispensing component  110  of the additive-manufacturing system  100  being moved, by the robotics equipment  1030  or surgeon, and depositing substrate material  220   1  between the vertebrae  120 ,  122  for in-situ printing the connecting implant, connecting the bone anchors  4500  and thereby the vertebrae. 
       FIG. 50  shows the dispensing component  110  of the additive-manufacturing system  100  repositioned to, or adjacent to, the starting position (from  FIG. 45 ) for applying catalyst. 
       FIG. 51  shows the dispensing component  110  of the additive-manufacturing system  100  being moved and applying catalyst  220   2  on, to, or at the substrate material  220   1 , connecting the bone anchors  4500 , and thereby the vertebrae  120 ,  122 . 
       FIG. 52  is a lateral view of the dispensing component  110  of the additive-manufacturing system  100  completing depositing of printing material  220   2 ,  220   1 , connecting the bone anchors  4500 , and thereby the vertebrae  120 ,  122 . 
       FIG. 53  shows an oblique perspective view of the in-situ printed connecting implant  5200 , connecting the vertebrae  120 ,  122 , according to the seventh general embodiment of the present disclosure. 
     Other embodiments of the present technology include in-situ-grown, formed, or in-situ-manufactured expandable cages, expandable implants, additive-manufacturing system for printing spinal implants in-situ, and methods for forming the same. In some embodiments, an in-situ expandable cage may be grown or formed in discrete portions that are positioned and/or re-positioned according to an iterative process. In other embodiments, a plurality of in-situ expandable cages may be sequentially grown or formed and repositioned or otherwise manipulated in order to fill a disc space between adjacent vertebrae and restore, support, or otherwise correct alignment of a patient&#39;s spine. In some embodiments, the plurality of in-situ expandable cages may be coupled together to form a rigid in-situ expandable spinal implant. 
     The term in-situ expandable cage, or in-situ expandable implant is used primarily herein to describe the subject interbody implant  10000 , or discrete components thereof, being formed within a surgical site of a patient and moved into a disc space to thereby expand the disc space. In some embodiments, multiple in-situ expandable cages are grown or formed and fused together and/or positioned adjacent one another and referred to as a single in-situ expandable implant. Exemplary use cases, methods of manufacture, and corresponding illustrations thereof are not meant to be limiting, such as limiting the shape or size of the internal spacing, unless otherwise described expressly in this specification or appended claims. 
       FIGS. 54 and 55  may show lateral views of a patient&#39;s vertebrae to be supported and/or manipulated by an in-situ printed expandable cage and/or a plurality of in-situ printed expandable cages. Exemplary embodiments may be used to correct alignment of a patient&#39;s spine in the coronal or sagittal plane, for example. In some embodiments, a target alignment may be predetermined by data parsing performed by controller  1050  in coordination with scanning data, navigation equipment  1095 , CT-Images, etc. which may assess a patients current spinal alignment and calculate a target alignment. For example, exemplary embodiments may include a robotic subsystem having robotics equipment  1030  scanning and imaging equipment configured to scan a patient&#39;s anatomy. Exemplary embodiments may further include an armature  112  including a dispensing component  110  configured to dispense at least one printing material. The controller apparatus  1050  may include a processor and a non-transitory computer-readable medium. The controller  1050  may be configured to control the scanning and imaging equipment to determine a target alignment of a patients spine, and develop in-situ-forming instructions including an in-situ relocation plan. In some embodiments, the in-situ-forming instructions may be based on the target alignment of the patients spine, an interbody access space which may only partially provide access to a disc space between adjacent vertebra of the patients spine. Controller  1050  may execute the in-situ-forming instructions to thereby control the armature  112  to dispense at least one printing material from dispensing component  110  to form at least one interbody cage having a size that corresponds to the size of the interbody access space. Controller  1050  may further control the armature  112  to position and/or reposition the at least one interbody cage within the disc space. 
     In some embodiments, controller  1050  may include proprietary software, such as, for example, a modified version and/or updated version of Medtronic&#39;s Mazur software platform, for analyzing and pre-operatively defining a geometry within a disc space of a patient. For example, controller  1050  may utilize the Mazur software in coordination with X-Ray Images and/or CT-Images with may be further processed to develop a three dimensional model of the disc space of the patient. In at least one embodiment, the controller  1050  generates a plan for the final three-dimensional geometry of a completed spinal implant. The final three-dimensional geometry of the completed spinal implant may be broken down into various segments or portions by the controller  1050 . For example, an interbody access space may be limited necessitating the final three-dimensional geometry being broken into individual segments. In this way, the controller  1050  may develop an in-situ printing plan. After the controller  1050  has developed the in-situ printing plan the controller may control printing of the various segments or portions as individual in-situ expandable cages, as will be explained in further detail below. 
     In some embodiments, controller  1050  may develop a pre-established in-situ printing plan including a pre-established in-situ relocation plan. Once a target alignment is determined, controller  1050  may also calculate a surgical sequence and/or installation sequence for printing at least one in-situ expandable cage, e.g., in-situ expandable cages of  FIGS. 54-68 . In those embodiments where controller  1050  determines multiple in-situ expandable cages are necessary the installation sequence may involve repositioning or otherwise manipulating at least one in-situ expandable cage before printing and/or repositioning a second in-situ expandable cage. Controller  1050  may also determine that multiple in-situ expandable cages having different shapes such as discs, wedges, etc. should be printed. The multiple cages may be printed sequentially and moved into position and/or repositioned as will be explained in further detail below. 
     In the disclosed embodiment of  FIGS. 54 and 55 , controller  1050  may have determined that two in-situ expandable cages should be printed to correct the particular patient&#39;s spinal alignment. However, it shall be understood that the disclosed embodiment of  FIGS. 54 and 55  is exemplary and that controller  1050  may determine an alternate surgical procedure or in-situ printing plan for other use cases depending solely on the particular variables of the specific patient being treated. In this way, controller  1050  may determine a custom surgical procedure for each particular patient. Similarly, disclosed expandable cages may be printed by any above disclosed technique and with any above disclosed procedure. For example, armature  112  may dispense a dispensing component  110  as previously disclosed hereinabove that may include any sequence of forming an interbody implant via a substrate and/or catalyst such as is, for example, disclosed in  FIGS. 13-22 . 
       FIG. 54  may illustrate the printing and installation of a first in-situ printed expandable cage  10000   a  and a second in-situ printed expandable cage  10000   b . The first in-situ printed expandable cage  10000   a  may be angled or wedge-shaped to some degree as may be determined by controller  1050 . For example, the term wedge-shaped may refer to a shape having a generally triangular cross section. However, it should be understood that the term wedge-shaped does not necessarily require a symmetrical shape and that edges of a wedge-shape may also be arcuate, e.g., some wedge-shapes may have a triangular cross section in the longitudinal direction and have an arc shaped edge portion and or curved/undulating edge portion when viewed from a top down view. Other shapes may be encompassed by this meaning provided they are angled to some degree in at least one direction. 
     Similarly, the second in-situ printed expandable cage  10000   b  may be rectangular, planar, or disc shaped as may be determined by controller  1050 . In the disclosed embodiment, it shall be understood that the desired correction may not be achievable with a single printed cage as may be determined by controller  1050  as explained above. For example, the relevant surgical procedure has a limited interbody access opening necessitating the printing of multiple in-situ printed expandable cages. 
     As illustrated in  FIG. 54 , the first in-situ printed expandable cage  10000   a  is positioned between a first patient vertebra  120  and a second patient vertebra  122 . The second in-situ printed expandable cage  10000   b  may be printed outside of the disc space or partially within the disc space and/or interbody access space depending on the size of the access space and the range of motion of the armature  112  and dispensing component  110 . Subsequently, the second in-situ printed expandable cage  10000   b  may be pushed or inserted into the disc space between the first and second vertebra  120 ,  122 . For example, controller  1050  may recognize that printing of the second in-situ printed expandable cage  10000   b  is complete and use armature  112  to push the second in-situ printed expandable cage  10000   b  into place. In some embodiments, armature may include an additional multi-axis robotic arm that may be used to push or manipulate in-situ printed expandable cages  10000   a ,  10000   b  if required. For example, a six axis telescoping robotic arm (not illustrated) having gripping portions or the like that is controlled or manipulated by controller  1050  and/or a surgeon. In some embodiments, the first in-situ printed expandable cage  10000   a  and second in-situ printed expandable cage  10000   b  may have a linking element configured to secure them together. First and second in-situ printed expandable cages  10000   a ,  10000   b  may be coupled together by a surgeon operably linking them together at any feasible time of the surgical procedure. Alternatively, in-situ printed expandable cages  10000   a ,  10000   b  may be coupled together via the linking element by armature  112  and/or other suitable robotic arm. An advantage to linking first and second in-situ printed expandable cages  10000   a ,  10000   b  is that it may facilitate assembly, positioning, correction, and/or removal by either the surgeon and/or robotic arm. The linking element may be any mechanical fastener, e.g., a hook, a groove and rail system, a screw for fastening the components together, either integral to the two parts or inserted after printing or final placement, or the like. As illustrated by arrows in  FIG. 55 , inserting the second in-situ printed expandable cage  10000   b  into the disc space may cause the first patient vertebra  120  to pivot or rotate towards the left (counterclockwise from the perspective of  FIG. 55 ) because of the wedge like shape of first in-situ expandable cage  10000   a . Thereafter, an alignment of a patient&#39;s spine may be corrected in the sagittal plane, coronal plane, and/or transverse plane. Furthermore, a spacing or height between vertebrae may be increased, or shifted, and/or an angle of inclination between adjacent vertebrae may be adjusted, as will be explained further in conjunction with  FIGS. 69-73 . 
     In some embodiments, armature  112  and/or disclosed robotic arms may be equipped with surgical tools for drilling pilot holes and/or installing self-tapping bone screws between adjacent vertebrae before the installation of first and second in-situ printed expandable cages  10000   a ,  10000   b . For example, bone screws and expansion/contraction devices may be used to mechanically position adjacent vertebrae in an initial desired position before printing. In some embodiments, bone screws may be used to open/enlarge the disc space and or adjust an angle of inclination between adjacent vertebrae. For example, the robotic arm may be equipped with a boring device to create an aperture (or lumen) in a first vertebrae imparting access to the disc space and a pin, rod, or the like may be insert into the aperture and through the disc space to push apart the adjacent vertebrae and enlarge the disc space. For example still, the robotic arm may install a first bone screw on a lateral side surface of a first vertebrae and a second bone screw on a lateral side surface of a second vertebrae and couple the first and second bone screws with an expansion/contraction device such as a turnbuckle or the like to mechanically separate the first and second endplates or bring them closer together. After the adjacent vertebrae are positioned in the initial position, the in-situ expandable cages may be positioned within the disc space consistent with disclosed embodiments herein. Additionally, any installed bone screws and expansion/contraction devices may be removed after the printed material cures and the aperture may be packed with bone growth promoting material to heal or close the aperture. Alternatively, any installed bone screw may remain in the corresponding vertebrae to provide additional support. 
       FIGS. 56-59  illustrate various axial views of a plurality of in-situ printed expandable cages being operably used to fill a disc space, e.g., to provide support between adjacent vertebrae by filling the disc space. As illustrated in  FIG. 56  a first in-situ printed expandable cage  10000   a  may be printed directly within a disc space and/or interbody access space. In some embodiments and surgical scenarios, the armature  112  and dispensing material  110  may only access a portion of the disc space. Accordingly, the first in-situ printed expandable cage  10000   a  may only partially fill the disc space and then, after being printed, may be subsequently moved farther into the disc space. For example, armature  112  may position a tip of nozzle and dispensing components  110  directly within the disc space that is accessible. Optionally, an annulus  10010  may be positioned in the disc space to provide support and further facilitate positioning of various disclosed in-situ printed expandable cages. In some embodiments annulus  10010  may include various fiducial markers that assist controller  1050  with developing in-situ printing instructions. In some embodiments, annulus  10010  may also be formed of printed material having the same or substantially similar properties as disclosed with respect to the in-situ printed expandable cages herein. Furthermore, annulus  10010  may be used to separate adjacent vertebrae, at least partially, and/or otherwise facilitate positioning the vertebra in a desired orientation before printing of various in-situ printed expandable cages. For example, annulus  10010  may be formed of a plurality of discrete and separable components that can be assembled in stages and coupled together to form a finished ring lake shape resembling annulus  10010  of  FIGS. 56-59 . In at least one embodiment, annulus  10010  is formed of several rigid sections having coupling portions on an end thereof and each section is installed independently and coupled to an adjacent section at a corresponding coupling portion. In some embodiments, annulus  10010  is formed of a plurality of discrete sections of printed material that are inclined with respect to the transverse plane of a patient and installed independently to wedge between adjacent vertebrae along a perimeter thereof and open the disc space between adjacent vertebrae (similar to the wedge concepts as explained hereinabove with respect to  FIGS. 54 and 55 ) to a desired position. 
     As illustrated, in the disclosed exemplary embodiment, annulus  10010  includes an aperture  10010   a  and a smooth interior surface that facilitates sliding or otherwise relocating first in-situ printed expandable cage  10000   a  in the disc space. For example, annulus  10010  may have a smooth curved interior surface that facilitates the sliding of a corresponding curved exterior surface of first in-situ printed expandable cage  10000   a . It is also contemplated that in some embodiments annulus  10010  may include a groove, channel, or rail operably coupled to a corresponding portion of first in-situ printed expandable cage  10000   a  such that an orientation of first in-situ printed expandable cage may be maintained and/or adjusted while moving/positioning first in-situ printed expandable cage  10000   a  within the disc space (not illustrated). In some embodiments, annulus  10010  may be printed and have the various grooves, channels, and/or rails inclined in any desirable orientation as may be determined by controller  1050  to execute the surgical procedure. For example, an angled groove may extend along the interior surface of annulus  10010  and be angled in a direction with respect to the extension direction such that when the expandable cage  10000   a  moves farther into the disc space the orientation or angulation of the expandable cage follows the path defined by the angled groove of the annulus. This may be advantageous in some surgical procedures where angular adjustment of a patient&#39;s spine in the coronal plane or sagittal plane is desirable. It shall also be appreciated that an external annulus  10010  may not be required in some surgical procedures because a patient&#39;s natural anatomy, i.e., the annulus fibrosis, may provide sufficient structure. In those embodiments, an opening or a plurality of openings may be formed by a surgeon and/or a robotically operated scalpel, e.g., armature  112  may also be configured to perform incisions and excisions if and when controller  1050  determines that a patients existing annulus fibrosis may provide sufficient structure after performing scanning and imaging as is consistent with previously disclosed embodiments. 
       FIG. 57  is an axial view of the first in-situ printed expandable cage  10000   a  of  FIG. 56  being repositioned in a disc space. As shown in  FIG. 57 , the first in-situ printed expandable cage  10000   a  is moved laterally to the side further into the disc space and away from aperture  10010   a . In some embodiments, aperture  10010   a  may correspond to an interbody access space. In  FIG. 58 , a second in-situ expandable cage  10000   b  is printed. The second in-situ expandable cage  10000   b  may be printed according to the same or substantially the same procedures as explained above with respect to first in-situ printed expandable cage  10000   a.    
     As shown in  FIG. 59 , the first and second in-situ printed expandable cages  10000   a ,  10000   b  may be repositioned laterally in the disc space farther away from aperture  10010   a . For example, robotics equipment  1030  and/or armature  112  may push against (urge or apply a force too) the second in-situ expandable cage  10000   b  which may in turn push against the first in-situ expandable cage  10000   b  thereby repositioning both in-situ expandable cages  10000   a ,  10000   b  farther into the disc space and away from aperture  10010   a . Additionally, in the disclosed embodiment, a third in-situ expandable cage  10000   c  may be printed in the accessible area of the disc space. The third in-situ expandable cage  10000   c  may be printed according to the same or substantially the same procedures as explained above with respect to first and second in-situ expandable cages  10000   a ,  10000   b . As illustrated, first, second, and third in-situ printed expandable cages  10000   a ,  10000   b ,  10000   c  may collectively fill the disc space. It shall be appreciated that any number of in-situ expandable cages  10000   a ,  10000   b ,  10000   c  may be printed and repositioned according to the above exemplary embodiment. 
       FIGS. 60-63  illustrate various axial views of a plurality of in-situ printed expandable cages that may printed and or repositioned according to techniques previously disclosed hereinabove.  FIG. 60  is an axial view of a first in-situ printed expandable cage  10000   a . Similar to previous embodiments, first in-situ printed expandable cage  10000   a  may be printed directly within the disc space between adjacent vertebrae and a size of first in-situ printed expandable cage  10000   a  may correspond to the extent of access to the disc space and/or interbody access space. 
       FIG. 61  is an axial view of the first in-situ printed expandable cage  10000   a  of  FIG. 60  that may be in the same position and orientation and a second in-situ printed expandable cage  10000   b  that may be printed partially within the disc space and partially outside of the disc space. It shall be understood that second in-situ printed expandable cage  10000   b  may be printed fully within or fully outside of the disc space. In this particular embodiment, second in-situ expandable cage  10000   b  may be wedge-shaped. As shown in  FIG. 62  by arrows, a force may be applied to second in-situ expandable cage  10000   b  pushing it into the disc space and thereby urging the first in-situ expandable cage  10000   a  farther into the disc space. In the disclosed embodiment, at least one advantage of the wedge shape of second in-situ expandable cage  10000   b  is that it may facilitate further opening of the disc space in a desired direction and/or orientation and assist in pushing first in-situ expandable cage further into the disc space. Another advantage is that second wedge-shaped in-situ expandable cage  10000   b  may further open and or otherwise increase access to the disc space. In some embodiments, the first in-situ expandable cage  10000   a  may have a groove configured to couple with a corresponding rail of the second in-situ expandable cage  10000   b  to further assist with alignment and or positioning. 
       FIG. 63  is an axial view of a third in-situ expandable cage  10000   c . Third in-situ expandable cage  1000   c  may be the same or substantially similar to the second in-situ expandable cage  1000   b . In this particular embodiment, third in-situ expandable cage  10000   c  is substantially the same as second in-situ expandable cage  1000   b . Third in-situ expandable cage  10000   c  may be printed farther inside of the disc space by virtue of first and second in-situ expandable cages  10000   a ,  10000   b  further opening and/or otherwise enlarging the disc space by being repositioned farther inside of the disc space. Third in-situ expandable cage may also be wedge-shaped and when an external force is applied to third in-situ expandable cage to urge it into the disc space the first and second in-situ expandable cages may move farther into the disc space away from aperture  10010   a  as shown by arrows. In some embodiments, the second in-situ expandable cage  10000   b  may have a groove configured to couple with a corresponding rail of the third in-situ expandable cage  10000   c  to further assist with alignment and or positioning. In this way, the first, second, and third in-situ expandable cages  10000   a ,  10000   b ,  10000   c  may be coupled as a single unitary spinal implant. Additionally, controller  1050  may determine a relevant size, length, and direction of each corresponding groove and rail to further assist with adjusting the disc space to the desired target alignment. 
       FIGS. 64-68  illustrate various axial views of a plurality of in-situ printed expandable cages that may printed and or repositioned according to techniques previously disclosed hereinabove, e.g., by controller  1050  and/or armature  112 . In the embodiment of  FIGS. 64-68 , annulus  10010  may include a first aperture  10010   a  that is the same as or substantially the same as previously disclosed hereinabove. Additionally, annulus  10010  may include a second aperture  10010   b  that may be the same or substantially the same as first aperture  10010   a . In the disclosed embodiment, aperture  10010   b  is slightly smaller than first aperture  10010   a  although in other embodiments aperture  10010   b  may be larger or smaller than first aperture  10010   a.    
       FIG. 64  illustrates a first in-situ expandable cage  10000   a ′, a second in-situ expandable cage  10000   b , and a third in-situ expandable cage  10000   c  filling or at least partially filling a disc space. First in-situ expandable cage  10000   a ′ may be a sacrificial cage that is used to open up the disc space in advance of second and third in-situ expandable cages  10000   b ,  10000   c . For example, first in-situ expandable cage may be formed of a flexible material, such as a smart function polymer or hydrogel material for example. Second and third in-situ expandable cages  10000   b ,  10000   c  may be formed of a rigid material, or at least a material that is relatively more rigid that the material used to form the first in-situ expandable cage  10000   a . However, in some embodiments, all of the in-situ expandable cages  10000   a ,  10000   b ,  10000   c , may be formed of the same material. 
     As illustrated in  FIG. 65 , a first portion of the flexible first in-situ expandable cage  10000   a ′ may be removed from second aperture  10010   b . The first portion of the flexible first in-situ expandable cage  10000   a ′ may be removed by applying a force to third in-situ expandable cage  10000   c  by armature  112  which pushes or forces the first portion of the flexible first in-situ expandable cage  10000   a ′ through second aperture  10010   b . In other embodiments, robotics equipment  1030  such as a multi axis robotic arm may grab an end portion of flexible first in-situ expandable cage  10000   a ′ and pull it out through aperture  10010   b . Additionally, in some embodiments flexible first in-situ expandable cage  10000   a ′ may be printed with retaining means such as hooks, loops, slots, magnetic material, interior netting, fiducial markers, etc. on end portions thereof that may facilitate the removal of flexible first in-situ expandable cage  10000   a ′. For example, robotics equipment  1030  may grab an end portion of retaining means of the flexible first in-situ expandable cage  10000   a ′ and pull the segment out.  FIG. 66  illustrates a second portion of the flexible first in-situ expandable cage  10000   a ′ being removed and  FIG. 67  illustrates a third portion of the flexible first in-situ expandable cage  10000   a ′ being removed. The second and third portions of the flexible first in-situ expandable cage  10000   a ′ may removed in the same or substantially the same way as the first portion of the flexible first in-situ expandable cage  10000   a ′. Although the disclosed embodiment illustrates first in-situ expandable cage  10000   a ′ being removed by way of first through third portions it shall be understood that first in-situ expandable cage  10000   a ′ may be broken down into any number of portions or it may even be removed as a single unit. For example, in some embodiments, the entire first in-situ expandable cage  10000   a ′ may be removed as a single unit in embodiments where first in-situ expandable cage  10000   a ′ is compliant and an appropriately sized opening (i.e., a corresponding opening) is provided for its removal. Furthermore, in some embodiments first in-situ expandable cage may be formed of a porous sponge like material the same as or similar to Gauze Sponges that may absorb bodily fluids and/or push them to the side out of an opening or act as a squeegee sweeping bodily fluids out of a corresponding opening in the annulus  10010 . At least one advantage of a surgical procedure using a sacrificial first in-situ expandable cage to clean the intervertebral disc space is that the chemical curing process of printed material may occur without being impeded, affected and/or contaminated by excess bodily fluids. An additional advantage may be that the curing printing material may not contaminate bodily fluids during the curing process before it has sufficiently cured to its design strength. For example, bodily fluids may not become contaminated due to leeching of materials while the printing material is soft and vice versa. 
       FIG. 68  illustrates the printing of a fourth in-situ expandable cage  10000   d . In some embodiments, printing of the fourth in-situ expandable cage  10000   d  may occur after the removal of the first, second, and third portions of the flexible first in-situ expandable cage  10000   a ′. In other embodiments, printing of the fourth in-situ expandable cage  10000   d  may occur concurrently, at least partially, with the removal of any of the first, second, and third portions of the flexible first in-situ expandable cage  10000   a ′. At least one advantage of printing the fourth in-situ expandable cage  10000   d  concurrently, at least partially, is that it can assist with preventing or otherwise suppressing a collapse of the disc space due to the removal of the first in-situ expandable cage  10000   a ′. In the disclosed embodiment, after the fourth in-situ expandable cage  10000   d  has been printed, robotics equipment  1030  and or armature  112  may apply a force to the fourth in-situ expandable cage  10000   d  to position it within the disc space and position the second and third in-situ expandable cages further into the disc space. 
       FIG. 69  illustrates a posterior view of a pair of adjacent vertebrae  120 ,  122  and a first pair of oppositely inclined in-situ printed expandable cages  10100  and a second pair of oppositely inclined in-situ printed expandable cages  10200  in a first position. In the disclosed embodiment of  FIG. 69 , the first and second pairs of oppositely inclined in-situ printed expandable cages  10100 ,  10200  may be printed by any above disclosed technique and with any above disclosed procedure. For example, armature  112  may dispense a dispensing component  110  as previously disclosed hereinabove that may include any sequence of forming an interbody implant via a substrate and/or catalyst such as is, for example, disclosed in  FIGS. 13-22  and may form in-situ printed expandable cages having wedge like features such as is, for example, disclosed in  FIGS. 56-59 . 
       FIG. 70  is a posterior view of the embodiment of  FIG. 69  after the pair of adjacent vertebrae  120 ,  122  and the first and second pairs of oppositely inclined in-situ printed expandable cages  10100 ,  10200  have been moved to a second position thereby opening the disc space. For example, as illustrated in  FIG. 70 , each central in-situ printed expandable cage of each pair of in-situ printed expandable cages  10100 ,  10200  may be moved by armature  112  towards the outside of the disc space (represented by the two horizontal arrows) to thereby distract (raise) the second vertebrae  122  with respect to the first vertebrae  120  (represented by the vertical arrow). In doing so, a void space may be created within the central portion of the disc space (not labelled). Thereafter, armature  112  and dispensing component  110  may be repositioned for printing within the void space of the central portion of the disc space.  FIG. 71  is a posterior view of the embodiment of  FIG. 70  after a third in-situ printed expandable cage  10300  is formed in the void space within the central portion of the disc space. As illustrated, the third in-situ printed expandable cage  10300  fills the void space to provide additional support between the adjacent vertebrae  120 ,  122 . 
       FIG. 72  is a posterior view of the embodiment of  FIG. 69  after the pair of adjacent vertebrae  120 ,  122  and the first and second pairs of oppositely inclined in-situ printed expandable cages  10100 ,  10200  are moved to a third position thereby opening the disc space and adjusting an angle of inclination between the adjacent vertebrae  120 ,  122  in the coronal plane. As illustrated, the first and second pairs of oppositely inclined in-situ printed expandable cages  10100 ,  10200  have been moved transversely by different amounts to incline the second vertebrae  122  with respect to the first vertebrae  120 . For example, the right most central in-situ printed expandable cage of the first pair of in-situ printed expandable cages  10100  may be moved by armature  112  towards the outside of the disc space (represented by the larger of the two horizontal arrows) and the left most central in-situ printed expandable cage of the second pair of in-situ printed expandable cages  10200  may be moved by armature  112  towards the outside of the disc space (represented by the smaller of the two horizontal arrows) to thereby incline the second vertebrae  122  with respect to the first vertebrae  120  (represented by the curved arrow). In doing so, a void space may be created within the central portion of the disc space (not labelled). Thereafter, armature  112  and dispensing component  110  may be repositioned for printing within the void space of the central portion of the disc space.  FIG. 73  is a posterior view of the embodiment of  FIG. 72  after a third in-situ printed expandable cage  10300  is formed in the void space within the central portion of the disc space. As illustrated, the third in-situ printed expandable cage  10300  fills the void space to provide additional support between the adjacent vertebrae  120 ,  122  to facilitate maintaining vertebrae  120 ,  122  in the inclined position. Therefore, the example embodiment of  FIGS. 72 and 73  may correct the alignment of a patient&#39;s spine in the coronal plane. However, it shall be understood that a substantially similar in-situ additive-manufacturing technique may be used to correct alignment of a patients spine in the sagittal plane. 
     Additional Example Aspects 
     Further regarding protecting the patient during the procedure, as mentioned above, in various embodiments, such as those involving application of chemical and/or heat in implant formation, care should be taken to ensure that patient tissue is not exposed to undesirable affects, including by not limited to undesirable levels of heat. It is also considered that the process could include cold fusing of materials. One example of such includes leveraging a cement reaction. These are other ways to protect the patient from extreme temperatures or conditions. 
     Further regarding customizing implant formation and structure to patient anatomy, as mentioned above, gauge(s) can be used to facilitate registering patient bone quality and adjusting the implant accordingly. For instance, if the gauge senses weak, or relatively weaker bone material adjacent the dispensing component  110 , the system  100  (e.g., computing controller  1050 ) could apply material accordingly, such as in higher volume or in a special configuration to better address the weakness, such as by a configuration that covers more surface area at, in, or adjacent the weak area. And as mentioned the converse can be true. That is, less material or a special configuration can be used when strong bone is detected, such as by using less material, which can save material and time, and so cost, allow more bony ingrowth (because there is less implant to get in the way), and be less invasive. In an additional aspect, the system  100  can in response to gauge recordings or other patient anatomy data (from imaging, etc.), form more or less channeling or voids, to guide bone growth into the implant more selectively, such as by promoting more bone growth in certain areas of the patient/implant. 
     Further regarding positive, or protruding features, as mentioned, the implant could be printed with protrusions, such as spikes, such that moving the adjacent vertebral body/ies to contact the implant would drive the protrusions into the vertebral body/ies, promoting implant securement in place. Along with or instead of spikes, these positive features (versus negative features like channels, holes, etc.) can include, for instance, teeth, ridges, detents, convexities, one-way teeth, the like, or other. As is consistent with this disclosure, lumens may be provided in disclosed in-situ cages for inserting positive features such as screws, pins, turnbuckles, rotary wedges, expandable shims, etc. on an as needed basis. 
     In a contemplated embodiment, positive features and negative features are formed and function together. A channel within an implant according to the present technology could have formed on its wall/s, for instance, a positive feature, such as a protrusion. Such positive feature/s within a negative feature can provide benefits such as promoting stronger bone in-growth to implant connectivity, and stronger resulting implant construct. Conversely, any implant positive feature, such as an outer surface protrusions, could have negative features formed therein, such as dimpling, holes, micro-channels, or the like. Benefits can include improved gripping (implant to patient), or increased bone in-growth to the implant, for example. 
     Any of the features disclosed with respect to any embodiments can be implemented with any of the other embodiments provided herein. Printing-material options described herein according to one or more embodiments can be used for implementing any of the other embodiments, for instance. 
     Any features from one or more embodiments can be implemented with any features described with respect to any other embodiment. 
     It should be understood that various aspects disclosed herein may be combined in combinations other than the combinations presented specifically in the description and the accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in other sequence, added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). 
     Any disclosure or claim herein referencing direction is not meant to limit interpretation of the disclosure, unless the disclosure or claim requires expressly such limitation. Reference, for instance, to depositing material on a vertebral surface is not limited to including printing on top of a generally horizontally disposed vertebral surface, and can include, for instance, printing on a partially or fully vertically disposed vertebral surface, for instance. As another example, references to a top or bottom of a grown or formed implant are not limited to indicating only an upper and a lower surface of the implant in a standing-patient reference frame. 
     Further regarding indications of direction, positioning and movement described in connection with components including but not limited to the dispensing component  110  are not restricted to the positioning and movement shown by way of examples in the figures. Actual positions and movements of the system  100  in use can be determined, pre-procedure or intra-procedure, by the computing controller  1050  and/or the surgeon or other surgical staff, and may differ from the positions and movements described or illustrated. 
     In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules. And aspects described as being performed by multiple modules or units, may be performed by a single module or unit in alternative embodiments. 
     Unless defined specifically otherwise herein, all terms are to be given their broadest possible interpretation including meanings implied from the specification as well as meanings understood by those skilled in the art and/or as defined in dictionaries, treatises, etc. It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless otherwise specified, and that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. 
     It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplification of the various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.