Implants with navigation fiducials

Abstract

To provide a system for manufacturing and using an implant for correcting a defect of a bone structure.SOLUTION: The implant includes a first surface comprising a shape configured to interface with a surface of the bone structure. In some examples, the implant includes a second surface opposite the first surface and substantially conformal to the shape of the first surface, the second surface comprising three or more point features on the second surface, wherein the three or more point features comprise a first point feature, a second point feature, and a third point feature that form nodes of a triangle, and each of the three or more point features is recessed below the second surface.SELECTED DRAWING: Figure 5D

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 031,888, filed May 29, 2020, the entirety of which is hereby incorporated by reference as if fully set forth below and for all applicable purposes. [Background technology]

[0002] Field of the Disclosure FIELD OF THE INVENTION This application relates to methods and apparatus for manufacturing and using implants that use navigation fiducials.

[0003] Description of Related Art Trauma, tumor resection, congenital anomalies, and other defects can result in the loss of bone tissue or otherwise disrupt bone structures, such as the complex and relatively thin bone structure that surrounds and supports the human eye. For example, such defects in the orbital wall, particularly the orbital floor, can cause the eyeball to move away from its natural position, potentially resulting in blurred vision, an aesthetically displeasing appearance, and in some cases, an inability to fully close the eyelids. These defects present challenging intra-bone repair and fixation problems in reconstructive and trauma surgery.

[0004] In some embodiments, implants can be used for internal repair of defects and fixation of fractures. Typically, implants can be in the form of a thin plate. Implants can be manufactured flat or pre-bent into a specific shape and can be shaped intraoperatively to fit an individual patient's anatomy. In some embodiments, implants can have a patient-specific form, where the shape, circumference, and surface contours are designed to match an individual patient's anatomy. Patient-specific implants generally provide a better fit to the patient's anatomy and easier implantation due to reduced intraoperative formation. Summary of the Invention [Problem to be solved by the invention]

[0005] However, as is typical in orbital implant surgery, and many other surgeries, the shape and accessibility of anatomical structures such as the eye socket may result in certain areas of the implant being located beneath soft tissue (e.g., the eyeball) upon implantation, thereby obscuring these areas from view. In one example, during surgery, if placement of the implant to restore the original position of the eyeball is not achieved initially, the surgeon may need to remove and reshape the implant, or even remove and reshape certain areas of the eye socket with implant material, resulting in a lengthy, trial-and-error surgery.

[0006] Restoring the eye's original position as closely as possible is important not only for aesthetic reasons, but also to avoid blurred vision. Therefore, it is important to increase the chances of a near-natural initial repositioning of the eye. In view of these and other considerations, devices and methods are described herein that improve the chances of successful implantation of an implant. [Means for solving the problem]

[0007] Certain aspects relate to (e.g., orbital) implants for correcting defects in (e.g., orbital) bone structures. The implant includes a first surface including a shape configured to interface with a surface of the bone structure (e.g., the floor and / or rim of the orbital bone structure). The implant also includes a second surface opposite the first surface and substantially conforming to the shape of the first surface, the second surface including three or more point features on the second surface, the three or more point features including a first point feature, a second point feature, and a third point feature that form nodes of a triangle, each of the three or more point features being recessed below the second surface.

[0008]

[0003] Certain aspects relate to a method for correcting a defect in a bony structure, including positioning a first surface of an implant over the defect in the bony structure, the first surface including a shape configured to interface with a surface of the bony structure (e.g., the floor and / or rim of an orbital bony structure), and a second surface opposite the first surface and substantially conforming to the shape of the first surface, the second surface including three or more point features, the three or more point features including a first point feature, a second point feature, and a third point feature that form nodes of a triangle, each of the three or more point features being at least one of raised above the second surface or recessed below the second surface. The method also includes tracing a stylus of a navigation system along the second surface until the stylus is received by each of the three or more point features to compare one or more of (i) the shape of the implant to a planned shape of the implant, or (ii) the position of the implant in the patient to a planned position of the implant in the patient.

[0009] Some aspects are directed to a method for generating an implant for correcting a defect in a bone structure. The method includes accepting an implant design, the design indicating the shape, size, and position of the implant relative to a corresponding build area in an additive manufacturing device. The implant design includes a first surface including a shape configured to interface with a surface of the bone structure (e.g., the floor and / or rim of an orbital bone structure) and a second surface that is opposite the first surface and substantially conforms to the shape of the first surface. The second surface includes three or more point features thereon, the three or more point features including a first point feature, a second point feature, and a third point feature that form nodes of a triangle. Each of the three or more point features is at least one of raised above or recessed below the second surface. The method also includes causing fabrication of the implant using additive manufacturing. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 illustrates an example of a suitable computing environment for embodiments of three-dimensional (3D) object design, build simulation, and manufacturing. [Figure 2] FIG. 2 is a functional block diagram illustrating an embodiment of the computer of FIG. [Figure 3] FIG. 3 is a diagram illustrating a process for manufacturing a 3D object or device. [Figure 4A] FIG. 4A illustrates an exemplary additive manufacturing apparatus for generating a 3D object. [Figure 4B] FIG. 4B illustrates a recoating mechanism (eg, a leveling drum / roller) that may be used in place of the recoating mechanism of FIG. 4A. [Figure 5A] FIG. 5A shows an exemplary orbital implant placed on the orbital floor of a patient's right eye socket. [Figure 5B] FIG. 5B shows an exemplary orbital implant placed on the orbital floor of a patient's right eye socket. [Figure 5C] FIG. 5C shows an exemplary orbital implant placed on the orbital floor of a patient's right eye socket. [Figure 5D] FIG. 5D shows an exemplary orbital implant placed on the orbital floor of a patient's right eye socket. [Figure 5E] FIG. 5E shows an exemplary orbital implant placed on the orbital floor of a patient's right eye socket. [Figure 6A] FIG. 6A illustrates an example pre-fabricated orbital implant and the same implant in a bent configuration for implantation, according to an embodiment of the present disclosure. [Figure 6B] FIG. 6B illustrates an example pre-fabricated orbital implant and the same implant in a bent configuration for implantation, according to an embodiment of the present disclosure. [Figure 7] FIG. 7 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 8]FIG. 8 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 9] FIG. 9 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 10] FIG. 10 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 11] FIG. 11 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 12] FIG. 12 illustrates a patient-specific orbital implant according to an aspect of the present disclosure. [Figure 13] FIG. 13 illustrates a patient-specific orbital implant according to an aspect of the present disclosure. [Figure 14] FIG. 14 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 15] FIG. 15 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 16] FIG. 16 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 17] FIG. 17 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 18] FIG. 18 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 19] FIG. 19 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 20] FIG. 20 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 21] FIG. 21 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 22] FIG. 22 illustrates a patient-specific orbital implant according to an aspect of the present disclosure. [Figure 23] FIG. 23 illustrates a patient-specific orbital implant according to an embodiment of the present disclosure. [Figure 24] FIG. 24 illustrates various embodiments of raised ridges according to aspects of the present disclosure. [Figure 25] FIG. 25 is a flow diagram illustrating an example operation using an optical implant. [Figure 26] FIG. 26 is a schematic diagram showing a conceptual embodiment of a navigation system. DETAILED DESCRIPTION OF THE INVENTION

[0011] The devices and methods disclosed herein include techniques for creating implants with navigational fiducials and for using the implants for improved surgical implantation and defect resolution procedures. While aspects of the present disclosure are exemplified with orbital implants, those skilled in the art will readily understand that they also apply to other types of implants, particularly implants that are partially or completely hidden from view during introduction into a patient's body or that can be shaped to better fit the patient's anatomy. In certain aspects, orbital implants include thin plates (sometimes perforated) or meshes. Features of the present disclosure may be discussed with respect to specific embodiments and figures below, but all embodiments of the present disclosure may include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be described as having particular advantageous features, one or more of such features may also be used in accordance with various other embodiments described herein. Similarly, while exemplary embodiments may be described below as device, instrument, or method embodiments, it should be understood that such exemplary embodiments may be implemented with a variety of devices, instruments, and methods. Unless explicitly stated otherwise, all method steps disclosed herein may be performed entirely by a computing device, partially by a computing device, or partially or completely by a skilled user, such as a medical professional or a non-medical professional such as a technician. Accordingly, the word "specialist" refers to such a skilled medical or non-medical user. For example, all method steps described for implant design and manufacture, including, but not limited to, image segmentation, defect reconstruction, implant design, implant bending, and implant manufacture, may be performed entirely by a computing device, partially by a computing device, or partially or completely by a skilled user, such as a medical professional or a non-medical professional such as a technician.

[0012] In this disclosure, the terms "distal" and "proximal" in the context of an implant refer to a location relative to the professional placing the implant when the implant is in its planned position relative to the patient's anatomy. For example, the distal edge of the implant is the edge that is farthest from the professional when the implant is in its planned, implanted position. In this disclosure, the terms "anterior" and "posterior" in the context of an implant refer to a location relative to the patient's anatomy when the implant is in its planned, implanted position. For example, the anterior edge of the implant is the edge that is most anterior to the patient when the implant is in its planned, implanted position.

[0013] In certain aspects, the orbital implant can be designed on a computer system using any suitable computer-aided design (CAD) software and / or any suitable system for designing, simulating, and / or manufacturing 3D objects. Referring to FIG. 1 , an example of a computer suitable for 3D object design, build simulation, and manufacturing embodiments is shown. The environment includes a system 100. The system 100 includes one or more computers 102a-102d, which may be, for example, any workstation, server, or other computing device capable of processing information. In some embodiments, each of the computers 102a-102d can be connected to a network 105 (e.g., the Internet) by any suitable communications technology (e.g., Internet Protocol). Thus, the computers 102a-102d can send and receive information (e.g., software, digital representations of three-dimensional (3D) objects, commands or instructions for operating additive manufacturing equipment, etc.) between each other via the network 105.

[0014] System 100 further includes one or more additive manufacturing devices (e.g., 3D printers) 106a-106b. As shown, additive manufacturing device 106a is directly connected to computer 102d (and with computer 102d connected to computers 102a-102c via network 105), and additive manufacturing device 106b is connected to computers 102a-102d via network 105. Thus, one skilled in the art will understand that additive manufacturing device 106 may be directly connected to computer 102, connected to computer 102 via network 105, and / or connected to another computer 102 and computer 102 via network 105.

[0015] It should be noted that while the system 100 is described with respect to a network and one or more computers, the techniques described herein also apply to a single computer 102 that may be directly connected to an additive manufacturing device 106.

[0016] 2 shows a functional block diagram of one embodiment of the computer of FIG. 1. Computer 102a includes a processor 210 in data communication with memory 220, input devices 230, and output devices 240. In some embodiments, the processor is also in data communication with an optional network interface card 260. Although described separately, it should be understood that the functional blocks described with respect to computer 102a need not be separate structural elements. For example, processor 210 and memory 220 can be embodied on a single chip.

[0017] The processor 210 may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any suitable combination thereof designed to perform the functions described herein. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0018] The processor 210 may be coupled to read information from or write information to memory 220 via one or more buses. The processor may additionally or alternatively include memory, such as processor registers. The memory 220 may include a processor cache, including a multi-level hierarchical cache, where different levels have different capacities and access speeds. The memory 220 may also include random access memory (RAM), other volatile storage, or non-volatile storage. The storage may include a hard drive, flash memory, etc.

[0019] The processor 210 may also be coupled to input devices 230 and output devices 240 for receiving input from and providing output to a user of the computer 102a, respectively. Suitable input devices include, but are not limited to, a keyboard, buttons, keys, switches, a pointing device, a mouse, a joystick, a remote control, an infrared detector, a barcode reader, a scanner, a video camera (e.g., which may be coupled to video processing software to detect hand gestures or facial gestures), a motion detector, or a microphone (e.g., which may be coupled to audio processing software to detect voice commands). Suitable output devices include, but are not limited to, visual output devices, including displays and printers; audio output devices, including speakers, headphones, earphones, and alarms; additive manufacturing devices; and haptic output devices.

[0020] Processor 210 may further be coupled to network interface card 260. Network interface card 260 prepares data generated by processor 210 for transmission over a network according to one or more data transmission protocols. Network interface card 260 also decodes data received over the network according to one or more data transmission protocols. Network interface card 260 may include a transmitter, a receiver, or both. In other embodiments, the transmitter and receiver may be two separate components. Network interface card 260 may be implemented as a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any suitable combination thereof designed to perform the functions described herein.

[0021] FIG. 3 illustrates a process 300 for manufacturing a 3D object or device. As illustrated, in step 305, a digital representation of the object is designed using a computer, such as computer 102a. For example, two-dimensional (2D) or 3D data may be input into computer 102a to assist in the design of the digital representation of the 3D object. Proceeding to step 310, information corresponding to the 3D object is transmitted from computer 102a to an additive manufacturing device, such as additive manufacturing device 106, which initiates a manufacturing process to generate the 3D object according to the received information. In step 315, additive manufacturing device 106 continues to manufacture the 3D object using an appropriate material, such as a polymer or metal powder. Further, in step 320, the 3D object is generated.

[0022] 4A illustrates an example additive manufacturing apparatus 400 for producing a 3D object. In this example, the additive manufacturing apparatus 400 is a laser sintering apparatus. The laser sintering apparatus 400 can be used to produce one or more 3D objects layer-by-layer. The laser sintering apparatus 400 can utilize a powder (e.g., metal, polymer, etc.), such as powder 414, to build an object one at a time as part of a building process.

[0023] Successive powder layers are spread on top of each other, for example, using a recoating mechanism 415A (e.g., a recoating blade). The recoating mechanism 415A deposits powder for a layer as it moves across the build zone, for example, in the direction shown, or in the reverse direction if the recoating mechanism 415A is starting on the other side of the build zone, for example, for another layer of the build. After deposition, a computer-controlled carbon dioxide (CO) laser beam scans the surface, selectively bonding together powder particles in corresponding cross sections of the product. In some embodiments, the laser scanning device 412 is an X-axis and Y-axis movable infrared laser source. Thus, the laser source can be moved along the X-axis and along the Y-axis to direct its beam to specific locations in the top layer of powder. Alternatively, in some embodiments, the laser scanning device 412 may include a laser scanner that receives a laser beam from a stationary laser source and deflects it on a movable mirror to direct the beam to a specified location within the work zone of the device. During laser exposure, the powder rises above the material (e.g., glass, polymer, metal) transition point, after which adjacent particles flow together to create the 3D object. The apparatus 400 may also optionally include a radiant heater (e.g., infrared lamp) and / or atmospheric control equipment 416. A radiant heater may be used to preheat the powder between recoating a new powder layer and scanning that layer. In some embodiments, the radiant heater may be omitted. An atmospheric control equipment may be used throughout the process to avoid undesirable conditions, such as powder oxidation.

[0024] In some other embodiments, such as shown with respect to FIG. 4B , a recoating mechanism 415B (e.g., a leveling drum / roller) may be used instead of recoating mechanism 415A. Thus, powder may be dispensed using one or more movable pistons 418(a) and 418(b) that push powder from powder containers 428(a) and 428(b) into a reservoir 426 that holds the compacted object 424. The reservoir depth is also controlled by movable piston 420, which increases the depth of reservoir 426 by moving downward as additional powder moves from powder containers 428(a) and 428(b) into reservoir 426. Recoating mechanism 415B pushes or rolls powder from powder containers 428(a) and 428(b) into reservoir 426. Similar to the embodiment shown in FIG. 4A , the embodiment of FIG. 4B may use only a radiant heater 416 to preheat the powder between layer recoating and scanning.

[0025] [Example of orbital implant] 5A-5E illustrate various stages in implanting an orbital implant in a patient.

[0026] FIG. 5A shows an example of a computer-generated three-dimensional (3D) model of a defect 508 in the orbital floor of a patient's right eye socket 500. A skilled user may generate a model of the defect 508 to better model the ideal placement and shape of an implant. For example, FIG. 5B shows an example of the model of FIG. 5A in which the healthy anatomical surface surrounding the defect 508 is aligned with a reconstructed anatomical surface 510 (e.g., the reconstructed anatomical surface 510 is a mirror image of the patient's orbital floor in the left orbit). This model of the desired bone structure may be used to generate a physical model of the desired bone structure (e.g., by additive manufacturing), which may serve as a bending form for pre-bending a pre-fabricated implant, or which may be used to design and manufacture a patient-specific implant.

[0027] FIG. 5C illustrates one embodiment of a model prefabricated orbital implant 520 placed over an orbital floor defect 508 in a patient's right eye socket 500. Here, the 3D models of FIGS. 5A and 5B provide a basis for determining the extent to which portions of the prefabricated orbital implant 520 should be bent or reshaped to best mimic the healthy anatomical surface 510 of FIG. 5B. The prefabricated orbital implant 520 includes three extensions 512 configured to be attached to the rim 506 of the orbital skeleton by fixation elements, such as screws. The 3D model of the bent or reshaped prefabricated implant can be used to design and fabricate a bending mold, as shown in FIG. 5E. FIG. 5E illustrates an example bending mold 550 for pre- or intraoperative bending of a prefabricated implant.

[0028] Figure 5D illustrates one embodiment of a model patient-specific orbital implant 502 placed on the orbital floor 504 of a patient's right eye socket 500 and attached to the rim 506 of the orbital bony structure, where the 3D model of Figures 5A and 5B provides a basis for designing the shape of the patient-specific orbital implant to best mimic the healthy anatomical surface 510 of Figure 5B.

[0029] As described above, the patient-specific orbital implant 502 may be designed based on information about the patient's orbital bone structure. Such information may be found in images, for example, from a computed tomography (CT) scan, a magnetic resonance imaging (MRI) scan, an ultrasound image, or other suitable medical imaging modality. Using the information in these medical images, a virtual 3D model of the patient's orbital bone structure can be developed (e.g., by Materialize Mimics software) through a process called "segmentation." Using CAD software, the orbital implant 502 may be specifically designed to fit with a portion of the patient's orbital bone structure to eliminate the structural defect. The orbital implant 502 may then be manufactured using additive manufacturing techniques, such as implant laser sintering or implant laser melting, described above, using any suitable material, such as titanium, titanium alloys, stainless steel, polyetheretherketone (PEEK), etc.

[0030] In some embodiments, defects in the orbital bone structure may prevent a specialist from developing a 3D model that accurately models the desired bone structure. In such cases, the specialist can instead model the contralateral orbital bone structure if that side is intact. Thus, a mirror image of at least a portion of the virtual 3D model including the contralateral eye socket may be aligned with the healthy tissue surrounding the defect and used as a template for the design of the orbital implant 502. Alternatively, a statistical shape model (SSM) of the orbital bone structure may be used to model the orbital bone structure based on the healthy or intact tissue and / or bone surrounding the defect. For example, the SSM may be constructed based on dividing or segmenting a digital image or a stack of digital images into multiple segments (e.g., sets of pixels or voxels). Segmentation then transforms the representation of the image into a relatively easier to analyze, such as a three-dimensional model, such as a wireframe model or surface model, encompassing one or more of such sets of pixels or voxels. In some embodiments, the digital image is analyzed to locate objects and / or boundaries, such as an anatomical region of interest. In this case, the anatomical region of interest can include the orbital bone structure. Based on a statistical analysis of the training set (e.g., the number of such three-dimensional models from a sample of the population), an SSM can be created. The SSM is a three-dimensional deformable representation that encodes the correlation between shape variations among members of the training set, which is assumed to represent the entire population. The SSM is characterized by a vector of limited length. By assigning values ​​to the coordinates of this vector, the SSM can be deformed to match the shape variations found in the training set. Once the SSM is created based on the training set of intact orbital bone, the SSM can be adapted to healthy or intact tissue and / or bone surrounding the defect. An example SSM thus obtained can include a portion spanning the defect and exhibit a shape representative of tissue without the defect. It can therefore be used to model the desired bone structure (i.e., reconstruct the defect). The desired bone structure can be used as a template for designing the orbital implant 502.The advantage of such a process is that it increases the likelihood that the eye will be pushed back into place, which is one of the main advantages of the patient-specific orbital implant 502. In some embodiments, the present disclosure relates to methods such as those described above for designing and / or manufacturing any of the patient-specific implants described below.

[0031] Preoperative planning can transfer many of the advantages of a patient-specific orbital implant 502 to a prefabricated implant (see, e.g., prefabricated orbital implant 600, described in more detail below in Figures 6A and 6B). For example, data about the patient's bony anatomy may be obtained from medical imaging (step 1) and used to develop (step 2) the 3D model (see, e.g., Figure 5A) described above (e.g., a model of the orbital bone structure). A target shape for the eye-facing surface of the orbital implant can then be designed (step 3) using the 3D model, a contralateral mirror image, and / or SSM to model the desired anatomy described above. The target shape may then be offset toward the bone over a distance equal to the implant's thickness. The target shape or resulting offset target surface can then be aligned (step 4) with a 3D model of the patient's bony structure surrounding the defect to obtain a 3D model of the desired bony structure (see, e.g., Figure 5B) to serve as a bending mold. This bending mold, i.e., a physical model of the desired bone structure, can be fabricated from the 3D model using additive manufacturing techniques in any suitable material, such as polyamide (step 5). A skilled user, such as a surgeon or a non-medical professional, such as a technician or engineer, can then use this mold to select the most appropriate type and size of pre-fabricated implant (e.g., see FIG. 6A) and bend (step 6—see FIG. 5C) the selected implant configuration to fit the patient's anatomy and target shape. In some embodiments, the present disclosure relates to kits of such bending molds and pre-fabricated implants. In some embodiments, the present disclosure relates to the above-described methods for designing and / or fabricating a physical model of the desired bone structure to serve as a bending mold as described above and / or for selecting and / or bending a pre-fabricated implant.

[0032] In some embodiments, the bending of a selected pre-fabricated orbital implant may be first simulated using a 3D model of the selected pre-fabricated implant and a 3D model of the patient's bone structure. The bending may be simulated so that the eye-facing surface of the orbital implant closely follows the shape of the subject and the bone-facing surface of the implant seats well in the bone structure surrounding or adjacent to the defect (see, e.g., FIG. 5C ). The simulated bending may allow a medical professional or a non-medical professional, such as a technician or engineer, to select an appropriate location for the implant. This may ensure that fixation points (e.g., attachment points where the orbital implant attaches to bone tissue) are in locations with good bone stock and that the implant is not in a location that could disturb or damage delicate anatomical features such as nerves. The simulated bending may allow the expert to ensure that the defect is adequately covered and that there is little or no excess implant material. In some embodiments, simulating the bending of the orbital implant may include selecting the most appropriate implant type, shape, and / or size from a library.

[0033] In some embodiments, the resulting shape of the virtual bent orbital implant can be used to generate an instruction set for a sheet metal bending machine configured to bend the implant according to the instructions. Alternatively, the resulting shape can be used to design a bending mold (see, for example, FIG. 5E ) that mates with either the eye-facing surface or the bone-facing surface of the simulated bend of the implant. For example, the bending mold can have any shape suitable for easy manipulation, such as a prismatic shape with a flat lower surface, and can have an upper surface configured to mate with either the eye-facing surface or the bone-facing surface of the virtual bent implant. The bending mold can include markings to outline the bent implant, or protrusions 552 to be received in one or more perforations in the implant or notches along the edge of the implant, such as mesh openings or any openings for receiving fixation elements. The bending mold can be manufactured from the design using any suitable material, such as polyamide, using additive manufacturing as described above. A skilled user can then bend the implant, using any markings and protrusions as an aid, until it fits into the bending mold (see FIG. 5E). The bent implant may then optionally be shipped to the hospital along with the mold. Alternatively, the mold may be shipped to the hospital along with the unbent implant. A surgeon or technician can then bend the implant, using any markings and protrusions as an aid, until it fits into the bending mold. In some aspects, the present disclosure relates to kits of such bending molds and pre-fabricated implants, either in their original state or in a pre-bent state. In some aspects, the present disclosure relates to the above-described methods for selecting and / or virtually bending a pre-fabricated implant, for providing a bending mold, and / or for bending a pre-fabricated implant.

[0034] Whether orbital implants are directly manufactured to a patient-specific shape or are prefabricated and bent according to preoperative planning procedures, accurate positioning of the patient's implant is important to restore the natural position of the eye. The shape and accessibility of the eye socket are such that orbital implants can often only be secured to the bone on one side of the implant, typically along the proximal edge of the implant. Small deviations from the planned position along this edge can lead to larger deviations along the eye-facing surface and the distal edge of the implant. Therefore, in some cases, a navigation system can be used during the surgical procedure to verify the position of the orbital implant relative to the patient's anatomy and compare this position to one or more of the planned positions or shapes of the planned target implant.

[0035] The surgical navigation system (see, e.g., FIG. 26 ) (i) loads (e.g., onto the electronic processing device 2606) and displays (e.g., on the display unit 2602) images or image feeds from intraoperative imaging equipment (e.g., digital / film cameras, radiography, magnetic resonance imaging (MRI), computed tomography (CT), fluoroscopy, ultrasound, echocardiography, nuclear medicine such as positron emission tomography (PET)), (ii) loads (e.g., onto the electronic processing device 2606) and displays (e.g., on the display unit 2602) a preoperatively generated virtual 3D model of the patient's anatomy, (iii) loads (e.g., onto the electronic processing device 2606) and displays (e.g., on the display unit 2602) a preoperatively generated virtual 3D model of any hardware, such as an implant, and (iv) tracks the location and orientation of instruments (e.g., using an infrared sensor 2610) and displays the coordinates of the navigation system. (v) using a tracked instrument, such as a probe or stylus (e.g., stylus 2608), to sweep the surface of an anatomical structure or certain anatomical landmarks to determine their position within the coordinate system of the navigation system, (vi) sweeping the surface of any hardware, such as an implant, or using a tracked instrument, such as a probe or stylus (e.g., stylus 2608), to indicate identifiable features of the hardware (e.g., navigational fiducials), such as points, lines, curves, and contours, to determine their position in the coordinate system of the navigation system, and (vii) establishing a relationship between the loaded virtual 3D model and (a) images or image feeds from intraoperative imaging equipment, and / or (b) establishing a relationship between data collected using the tracked instrument to accurately position the virtual 3D model in the coordinate system of the navigation system. For example, data collected according to (v) may be used to locate the patient in the coordinate system of the navigation system and / or to align the patient's and preoperatively created virtual 3D models of the patient's anatomy to a common coordinate system.For example, a relationship can be established between a "real" coordinate system and a "virtual" coordinate system; one way to do this is by sweeping the surface of the patient's anatomy to establish a correspondence between the patient's anatomy and a loaded preoperatively created virtual 3D model of the patient's anatomy.

[0036] As discussed, a 3D model can be generated from a medical image using topological and geometric information gleaned from the image. In some embodiments, the relationship between the coordinate system of the 3D model and the real coordinate system is established by matching corresponding anatomical landmarks in both the patient and the virtual 3D model. In other embodiments, the relationship between the coordinate system of the 3D model and the real coordinate system is established by generating a trajectory along the axes of the geometric model that matches the same trajectory along the axes of the patient's anatomy and performing a trihedral modeling that moves along the trajectory.

[0037] Once the patient is positioned in the navigation system's coordinate system, any further movement of the patient relative to the navigation system can be tracked by a tracker 2612 rigidly attached to the patient's anatomy 2616, and optionally another tracker 2614 attached to the stylus 2608, and spatial correspondence can be maintained between the actual patient and the virtual 3D model of the anatomy. For example, the information gathered according to (vi) can be used to identify the location of any hardware in the navigation system's coordinate system and / or to bring the hardware and the virtual 3D model created prior to operation of the hardware into a common coordinate system. For example, the same sweeping procedure described above can be performed to establish the relationship between the 3D model of the orbital implant (and corresponding coordinate system) and the actual physical orbital implant.

[0038] Thus, the surgical navigation system can be used to verify the position of an orbital implant during a procedure to introduce the implant into a patient (e.g., a virtual 3D model of the patient's anatomy and a virtual 3D model of the orbital implant (e.g., either a patient-specific form or a pre-fabricated form with or without a planned simulated flexion) in its planned position relative to the virtual 3D model of the patient's anatomy). The virtual 3D model of the patient's anatomy can be used to accurately position the 3D model of the orbital implant in the coordinate system of the navigation system.

[0039] In some embodiments, the professional may use a tracked instrument of the navigation system, such as a probe or stylus, to track specific features of the orbital implant. By tracking the implant features, the positions of these features can be collected, and the positions of the features in the navigation system's coordinate system can be determined and displayed on the navigation system. By locating the actual implant features in the coordinate system, the position of the implant can be compared to the planned position (e.g., the position of a 3D model of the orbital implant relative to a 3D model of the patient's anatomy). The navigation system can measure any deviation between the actual physical position of the implant and the planned position of the implant and report the deviation to the professional, optionally along with instructions on how to correct the position of the implant to match the planned position.

[0040] Thus, by utilizing identifiable features placed at specific locations on the implant to establish the spatial position of the implant, the surgical navigation system can determine the extent to which the planned bending of the optical implant has been achieved and / or the extent to which the position of the optical implant matches the planned position.

[0041] Example Techniques for Making and Using Orbital Implants with Navigational Fiducials 6A illustrates an example pre-fabricated orbital implant 600 according to aspects of the present disclosure. The desired shape of the pre-fabricated implant 600 may be determined either pre-operatively or intra-operatively, and the implant may be bent pre-operatively or intra-operatively to fit the patient's anatomy. While bending the implant, any of the bending molds described above may be used.

[0042] As shown, the prefabricated orbital implant 600 includes linear slots 602 that perforate the implant, or bend locations in the form of constricted connections 604. Such bend locations locally reduce the implant's resistance to deformation while dividing the implant into several main sections 606 (e.g., first main section 606a, second main section 606b, and third main section 606c), where the constricted connections 604 connect a number of holes 608 that can secure the implant 600 to the patient's bone structure.

[0043] The orbital implant 600 also includes a plurality of point features 610 that a professional can use to assess the position of the implant 600 in a coordinate system. For example, the point features 610 may be configured to accept a stylus so that position information can be fed back to a navigation system. In some embodiments, the point features 610 may be positioned on a surface of a section and / or along an edge thereof, such as an edge it shares with an adjacent section. In certain embodiments, the point features 610 may include holes at the ends of the linear slots 602. This may allow a professional using a stylus to trace the linear slots 602 to the point features 610. In some embodiments, the linear slots 602 may be path features that provide stylus position information in addition to the point features 610. FIG. 6B illustrates an example of bending the orbital implant 600 of FIG. 6A, where the implant 600 is bent to mimic the orbital floor of a patient's healthy anatomy.

[0044] By placing the features of the actual implant in the same coordinate system as the patient's anatomy, the position of the implant can be compared to the planned position (e.g., the position of a 3D model of the orbital implant relative to a 3D model of the patient's anatomy). The navigation system can measure any deviations between the actual physical position of the implant (of a function or part) and the planned position of the implant (of a function or part) and report the deviations to the specialist, optionally with instructions on how to modify the position of the implant to match the planned position and / or how to perform additional flexion of the implant to match the planned implant shape. Alternatively, the shape of the desired anatomy can be reconstructed preoperatively as described above (e.g., by utilizing a mirror image of the intact contralateral orbital cavity or an SSM of the intact orbital cavity). By intraoperatively placing features of the implant pre-placed in the patient, the navigation system can compare the positions of these features to the shape of the desired anatomy of the orbit and report the deviations to the specialist, optionally with instructions on how to modify the position of the implant and / or perform additional flexion of the implant to better match the shape of the desired anatomy of the orbit.

[0045] Typically, patient-specific implants are designed specifically for an individual patient and manufactured according to a design developed pre-operatively. While any number of point features can be used, patient-specific implants may require fewer point features compared to off-the-shelf orbital implants because patient-specific implants require less or no adjustment to the implant shape.

[0046] FIG. 7 illustrates a patient-specific orbital implant 700 according to an embodiment of the present disclosure. As shown, the top of the implant 700 is an eye-facing surface 704, and a bone-facing surface 710 is on the opposite side of the implant 700. The bone-facing surface 710 is configured to interface with a portion of the patient's anatomy (e.g., a portion of the floor and / or anterior rim of the orbital cavity). To this end, the bone-facing surface 710 may be partially or entirely shaped to mate with a surface of the patient's anatomy. Holes (e.g., first hole 706 a and second hole 706 b) are provided on the proximal edge of the implant 700 to accommodate screws or other attachment elements configured to secure the implant 700 to the anatomy of the eye socket. The implant 700 includes a raised ridge 708 along the distal edge of the implant 700. The implant 700 also includes three point features (e.g., a first point feature 702a, a second point feature 702b, and a third point feature 702c) in the formation of a non-isosceles triangle in this example. In some examples, the point features may be spread as widely as possible to increase the robustness of the implant location determination.

[0047] In this example, the second point feature 702b and the third point feature 702c take the form of depressions or recesses in the eye-facing surface. These two point features are near the proximal edge of the implant 700 and are therefore easier to reach with a tracked stylus compared to the first point feature 702a, which is closer to the distal edge of the implant 700. Now, when using a navigation system to determine the location of the implant 700, a professional can insert the distal tip of the navigation system's stylus into the point feature 702 and map the location of the implant.

[0048] As described above, the first point feature 702a is located closer to the distal edge of the implant 700 and, therefore, further away from the surgeon implanting the implant 700. During implantation, the distal edge of the implant 700 may be located beneath soft tissue and the eye, which may obscure the first point feature from the surgeon's vision. Therefore, to guide the stylus, the raised ridge 708 is configured to guide the stylus into the first point feature 702a. In this embodiment, the raised ridge 708 has at least one sidewall that is positioned at an angle 2402 from the surface facing the eye. In some embodiments, the angle may be greater than 45° (e.g., an angle between 60° and 90°, see first cross section 2400a of FIG. 24). The height of the raised ridge 708 may be high enough to prevent the tip of a stylus from slipping over the ridge, but low enough so as not to cause irritation to the soft tissue overlying the implant 700 while in an implanted state (e.g., a height of 0.5 mm to 1.5 mm). As described below, the raised ridge 708 may include one or more other shapes and sizes.

[0049] To verify the position of the implant intraoperatively, the surgeon can place the tip of a stylus at the second point feature 702b and the third point feature 702c to indicate the proximal point feature. The surgeon can also trace the tip of the stylus distally across the surface facing the eye until the stylus hits the raised ridge 708. Then, by sliding the stylus laterally along the raised ridge 708, the surgeon can guide the tip of the stylus to the first point feature 702a. Thus, visual access to the distal region of the implant is not necessary.

[0050] The stylus may include a beveled tip, or alternatively, a straight tip. However, a stylus with a straight tip may have difficulty entering a hole or cavity due to the narrow access between the implant and the soft tissue and the resulting sharp angle to the surface facing the eye. Therefore, the stylus may need to be held in a position close to a tangent to the surface (e.g., at an angle between the stylus shaft and the surface of 30 degrees or less). Thus, as shown in FIG. 7 , the first point feature 702a is a wedge-shaped depression that opens toward the proximal side of the implant 700 to accept the stylus. While pushing the tip of the stylus along the raised ridge 708, the surgeon can sense the stylus dropping into the depression. Thus, once in the depression, the surgeon can continue to push the stylus distally to hold the tip of the stylus at the apex of the depression until the stylus contacts the raised ridge 708. It should be noted that any of the point features described herein may include one or more of a dimple, depression, hole, or any other suitable physical marking on the eye-facing surface to indicate that the stylus has reached a particular point or location on the implant. In certain embodiments, at least three point features may be used, as three points may be sufficient to accurately locate the implant in a coordinate system. In certain aspects, the three points form a triangle (such as a non-isosceles triangle) such that each edge length between the points is different, so that each edge can be distinguished to better determine the position and orientation of the implant in the coordinate system.

[0051] FIG. 8 illustrates a patient-specific orbital implant 800 according to an embodiment of the present disclosure. The implant 800 includes several features similar to those shown in FIG. 7, including a first point feature 802a located near the distal edge of the implant 800 and a second point feature 802b and a third point feature 802c near the proximal edge. However, in this example, a raised ridge 808 at the distal end of the implant 800 includes a notch 804 that partially surrounds the first point feature 802a. The notch 804, in addition to the depression in the first point feature 802a, may be configured to indicate to the surgeon that they are manipulating the stylus when the tip of the stylus reaches the first point feature 802a. In some examples, the notch 804 may be used as an alternative to a depression feature. An interruption in the raised ridge 808 may be used as an alternative to the notch 804. For example, the raised ridge 808 may include a gap or notch configured to act as a first point feature, the gap being smaller than the diameter of the tip of the stylus so as to "capture" the stylus.

[0052] FIG. 9 illustrates a patient-specific orbital implant 900 in accordance with an embodiment of the present disclosure. The implant 900 includes several features similar to those shown in FIGS. 7 and 8. Referring to FIGS. 7 and 8, the implant 900 includes a first point feature 902a located near the distal edge of the implant 900, and second and third point features 902b and 902c near the proximal edge. In this example, the implant 900 includes a raised ridge 904 that does not follow the distal edge of the implant 900 but rather follows a V-shaped trajectory. Here, when a surgeon presses a stylus against the raised ridge 904, the stylus is guided toward the apex of the V, where the first point feature 902a is located. The surgeon can sense the change in direction of the raised ridge 904 and know that they have reached the first point feature 902a. When two or more point features are disposed along the raised ridge 904, the trajectory of the raised ridges may be shaped as concave and / or multi-lines, with segments between the point features (e.g., straight raised ridges). The first point feature 902a may optionally include a recessed region to help "capture" the stylus. As in the above examples, the raised ridge may include a notch at least partially surrounding the first point feature 902a, or an interruption in the first point feature 902a.

[0053] FIG. 10 illustrates a patient-specific orbital implant 1000 in accordance with an embodiment of the present disclosure. The implant 1000 includes several features similar to those shown in FIGS. 7-9, which may not be further described for the sake of brevity. In this example, a raised ridge 1004 runs from the third point feature 1002c to the first point feature 1002a, rather than running near the distal edge of the implant 1000 as in previous examples. After pointing the stylus at the third point feature 1002c (e.g., the point feature visible to the surgeon), the surgeon can slide the tip of the stylus along the raised ridge 1004 until it reaches the first point feature 1002a. The raised ridge 1004 has a hook or hockey stick shape that curves around the first point feature 1002a to capture the stylus at the first point feature 1002a and signal the surgeon when the stylus has reached that point feature.

[0054] FIG. 11 illustrates a patient-specific orbital implant 1100 according to an embodiment of the present disclosure. The implant 1100 includes several features similar to those shown in FIGS. 7-11, which may not be further described for the sake of brevity. Here, the implant 1100 includes a raised ridge 1104 that follows a path between a third point feature 1102c and a first point feature 1102a. The raised ridge 1104 also has a second leg that continues from the first point feature 1102a to the second point feature 1102b. Because the raised ridge 1104 is continuous, a stylus can be guided through the entire sequence of point features.

[0055] FIG. 12 illustrates a patient-specific orbital implant 1200 in accordance with an embodiment of the present disclosure. The implant 1200 includes several features similar to those shown in FIGS. 7-11 , which may not be further described for brevity. Here, the implant 1200 includes a raised ridge 1204 for guiding a stylus to one or more point features. However, because the point features are located on one side of the raised ridge 1204, the raised ridge 1204 includes a series of alternating depressions and protrusions 1206 configured to notify the surgeon when the stylus is along the wrong side of the raised ridge 1204 by preventing the stylus from moving and / or advancing along the side of the raised ridge 1204 more difficultly. Such a warning mechanism may be combined with the raised ridge of any of the other embodiments.

[0056] FIG. 13 illustrates a patient-specific orbital implant 1300 in accordance with an embodiment of the present disclosure. The implant 1300 includes several features similar to those shown in FIGS. 7-12, which may not be further described for brevity. Here, a first point feature 1302a is a depression at the apex of a raised ridge 1304. The depression has an elongated shape to receive the tip of a stylus held close to a tangent to the eye-facing surface. The raised ridge 1304 includes a side surface that provides a smooth or gradual transition 1306 from the top of the raised ridge 1304 to the surface of the implant 1300. The smooth transition 1306 prevents the stylus from being guided along the wrong side of the raised ridge and instead allows the stylus to be guided to the correct side without having to lift the stylus off the surface of the implant 1300. Such a smooth transition may be combined with any of the raised ridges of the other embodiments.

[0057] FIG. 14 illustrates a patient-specific orbital implant 1400 in accordance with an embodiment of the present disclosure. The implant 1400 includes several features similar to those shown in FIGS. 7-13, which may not be further described for brevity. Here, the implant has a raised ridge 1406 configured to guide a stylus toward a point feature 1402. In contrast to the previous embodiment, the raised ridge 1406 is positioned inside the triangle formed by the point feature 1402. In this embodiment, the raised ridge 1406 forms a plateau 1406 within the shape of the triangle. However, in some embodiments, the center of the triangle may include a ridge that is the same as the surface of the implant 1300 outside the triangle. The implant 1400 also includes a plurality of perforations 1404 passing through the opposite side of the eye-facing surface. The size of the perforations 1404 may be relatively smaller than the point feature 1402 and / or the stylus to prevent the surgeon from accidentally pointing at the point feature. Note that in this embodiment, there are no perforations 1404 along the path between the point features 1402. This prevents the stylus from getting caught in the perforations or accidentally pointing at the point features 1402. Such perforations 1404 may be combined with any of the other embodiments. The plateau-shaped raised ridges 1406 may also be used without the perforations 1404.

[0058] The following examples demonstrate how the above features can be freely combined and are not intended to limit the scope of the disclosure.

[0059] 15 illustrates a patient-specific orbital implant 1500 according to an embodiment of the present disclosure. The implant 1500 includes several features similar to those shown in FIGS. 7-14, which may not be further described for the sake of brevity. Here, the implant 1500 includes perforations 1504 and raised ridges 1506 configured to guide a stylus between point features 1502.

[0060] 16 illustrates a patient-specific orbital implant 1600 in accordance with an embodiment of the present disclosure. The implant 1600 includes several features similar to those shown in FIGS. 7-15, which may not be further described for the sake of brevity. Here, the implant 1600 includes perforations 1604, raised ridges 1606 configured to guide a stylus between point features 1602. In this example, the first point feature 1602a is a depression, and the second point feature 1602b and the third point feature 1602c are holes or depressions.

[0061] FIG. 17 illustrates a patient-specific orbital implant 1700 according to an embodiment of the present disclosure. The implant 1700 includes several features similar to those shown in FIGS. 7-16 , which may not be further described for brevity. Here, the implant 1700 includes perforations 1704 and a raised ridge 1706 configured to guide a stylus between point features 1702. Because the point features are located on one side of the raised ridge 1706, the raised ridge 1706 includes a series of alternating depressions and protrusions 1708 configured to alert the surgeon to a stylus along the wrong side of the raised ridge 1706 by preventing the stylus from moving and / or by making progression of the stylus along that side of the ridge 1706 more difficult. In this example, the first point feature 1702 a, the second point feature 1702 b, and the third point feature are holes or depressions.

[0062] FIG. 18 illustrates a patient-specific orbital implant 1800 according to an embodiment of the present disclosure. The implant 1800 includes several features similar to those shown in FIGS. 7-17 , which may not be further described for brevity. Here, a first point feature 1802 a is a depression at the apex of a raised ridge 1806. The raised ridge 1806 includes sides that form a smooth transition 1808 from the top of the raised ridge 1806 to the surface of the implant 1800. The smooth transition 1808 allows the stylus to be guided to the correct position without having to lift the stylus off the surface of the implant 1800 if the stylus is guided too far from the point feature.

[0063] 19 is a diagram illustrating a patient-specific orbital implant 1900 according to an embodiment of the present disclosure. The implant 1900 includes several features similar to those shown in FIGS. 7-18, which may not be further described for the sake of brevity. Here, the implant includes a plurality of perforations 1904 and a raised ridge 1906 connecting three point features 1902.

[0064] 20 illustrates a patient-specific orbital implant 2000 according to an embodiment of the present disclosure. The implant 2000 includes several features similar to those shown in FIGS. 7-19, which may not be further described for the sake of brevity. Here, the implant 2000 includes a raised ridge 2004 having a smooth transition 2006 connecting three point features 2002 characterized by depressions.

[0065] 21 illustrates a patient-specific orbital implant 2100 according to an embodiment of the present disclosure. The implant 2100 includes several features similar to those shown in FIGS. 7-20, which may not be further described for the sake of brevity. Here, the implant 2100 includes a raised ridge 2104 having a smooth transition 2106 connecting three point features 2102 characterized by holes.

[0066] 22 is a diagram illustrating a patient-specific orbital implant 2200 according to an embodiment of the present disclosure. The implant 2200 includes several features similar to those shown in FIGS. 7-21, which may not be further described for the sake of brevity. Here, the implant 2200 includes a raised ridge 2204 connecting three point features 2202. The first point feature 2202a is a depression, and the second point feature 2202b and the third point feature 2202c are indentations.

[0067] 23 illustrates a patient-specific orbital implant 2300 according to an embodiment of the present disclosure. The implant 2300 includes several features similar to those shown in FIGS. 7-22, which may not be further described for the sake of brevity. Here, the implant 2300 includes a raised ridge 2304 connecting three point features 2302, each of which is a hole.

[0068] FIG. 24 illustrates six different embodiments of raised ridges that can be used on an optical implant. The first raised ridge 2400a is a "top surface" ridge, meaning that the raised ridge extends along the edge of the implant (see, for example, raised ridges 708 / 808 in FIGS. 7 and 8). The second raised ridge 2400b is wave-shaped and has a recess in the ridge that can better accommodate the tip of a stylus. The third raised ridge 2400c is a raised ridge that is formed away from the edge of the implant (see, for example, the raised ridges in FIGS. 10-13 and 15-23). ​​The fourth raised ridge 2400d is wave-shaped and has a recess in the ridge that can better accommodate the tip of a stylus. The fifth raised ridge 2400e is a plateau-type ridge, as described above in FIG. 14. And the sixth raised ridge 2400f is a raised ridge having a smooth transition from the top of the ridge to the surface of the implant (see, for example, the raised ridges in Figures 18, 20, and 21 having a smooth transition from the ridge to the surface of the implant facing the eye).

[0069] In certain embodiments, raised ridges may replace gutters (e.g., grooves, depressions). Thus, implants according to embodiments herein may have non-planar guiding features that refer to raised ridges and / or grooves. However, raised ridges offer the advantage of not locally weakening the implant. In other words, they do not reduce the implant's mechanical strength or its resistance to deformation. Moreover, as noted above, in the distal region of the implant where stylus guidance is most needed, the stylus may be angled approximately tangentially to the implant's eye-facing surface, which may increase the risk of the stylus tip leaving the gutter or may completely prevent the stylus tip from remaining in and behind the gutter. Therefore, raised ridges may be preferred.

[0070] It is also possible to combine two raised ridges spaced a distance between them to establish a channel for guiding the stylus tip. However, similar to a gutter, in the distal region of the implant, angling of the stylus relative to the implant surface may increase the risk of the stylus tip leaving the channel, or may completely prevent the stylus tip from remaining in and after the channel. Therefore, it may be preferable to provide the implant with a raised ridge or series of raised ridges on only one side of the stylus "path", for example a trajectory or range of trajectories that the tip may be expected to follow on the way to a point feature, or a trajectory that establishes a path feature, such as the distal side.

[0071] 25 is a flowchart illustrating operations 2500 for using an orbital implant according to embodiments disclosed herein. The operations 2500 may be implemented as software components that run on and execute on one or more processors (e.g., electronic processing unit 2606 of FIG. 26) in conjunction with one or more medical devices (e.g., stylus 2608 of FIG. 26).

[0072] In a first block 2501, operation 2500 includes loading a virtual model containing the design or planned shape of an orbital implant into a navigation system and aligning it with a common coordinate system with a real patient. For example, a virtual 3D model of a portion of the patient's anatomy may be loaded, and the virtual model of the implant and the virtual model of the anatomy may be loaded, such that the implant is in its planned position relative to the patient's anatomy. The real patient and the virtual model of the anatomy may then be registered (e.g., aligned with a common coordinate system). For example, a stylus of the navigation system may be used to indicate anatomical landmarks on the patient's anatomy. The positions of these anatomical landmarks may then be aligned with the positions of corresponding anatomical landmarks in the virtual model of the anatomy, while maintaining the relative position of the virtual model of the implant to the virtual model of the anatomy.

[0073] In a second block 2502, the operation 2500 includes a step of positioning a first surface of an orbital implant over a defect in the orbital bone structure, the first surface having a shape configured to interface with the bottom and / or rim of the orbital bone structure, a second surface opposite the first surface and substantially conforming to the shape of the first surface, the second surface including three or more point features on the second surface, the three or more point features including a first point feature, a second point feature, and a third point feature that form nodes of a triangle, each of the three or more point features being at least one of raised above the second surface or recessed below the second surface.

[0074] 5A-5D, the shape of the first surface can roughly mimic the shape of the bottom surface of the structure and / or the edge of the orbital bone structure to allow for more or less stable positioning of the implant on the bone structure. Alternatively, as described above for patient-specific implants, part or all of the shape of the first surface can be designed to closely follow the shape of the bone structure to mate therewith.

[0075] For example, as shown in Figures 6 and 7, the orbital implant 600 / 700 may include a plurality of point features 610 / 702. Specifically, in Figure 6, the point features 610 may be recessed to the extent that they are perforations within the implant 600. In Figure 7, the first point feature 702a is a wedge-shaped depression or indentation below the second surface, while the second point feature 702b and the third point feature 702c are indentations recessed below the second surface.

[0076] In a third block 2504, the operation 2500 includes tracking a stylus of the navigation system along the second surface until the stylus is received by each of the three or more point features to compare one or more of: (i) the shape of the orbital implant to the planned shape of the orbital implant, or (ii) the position of the orbital implant in the patient to the planned position of the orbital implant in the patient. For example, the surgeon may track the stylus along the second surface of the implant (e.g., the facing surface of the eye) and form contact points between the stylus and each of the three or more point features. In this manner, the physical act of sweeping the stylus or making contact between the stylus and the point features provides the navigation system with the locations of those features in the navigation system's coordinate system. In some embodiments, forming contact between the stylus and a point feature, particularly a feature near the distal edge of the implant, may include sliding the stylus distally along the second surface until the tip of the stylus contacts a raised ridge on the implant, and then sliding the tip of the stylus along the raised ridge until the tip of the stylus rests against the point feature.

[0077] In fourth block 2506, operation 2500 may optionally include receiving an indication of a difference between one or more of: (i) the shape of the orbital implant relative to the planned shape of the orbital implant; or (ii) the position of the orbital implant in the patient relative to the planned position of the orbital implant in the patient. For example, once the position of the point feature in the navigation system's coordinate system has been determined, the navigation system may compare the position of the point feature determined by touching the implant with a stylus with the position of the point feature in the virtual 3D model of the implant's planned shape that was brought into the navigation system's coordinate system in first block 2501. The navigation system may then determine any differences, such as a difference between the constellation of point features in the actual implant and the constellation of point features in the virtual 3D model of the implant's planned shape, or a difference—derived from such differences—between the actual implant's shape and the implant's planned shape, and report the differences to the user. In another example, the navigation system can compare the positions of point features determined by touching the implant with a stylus to the positions of point features of a virtual 3D model of the implant relative to a virtual model of the patient's anatomy (e.g., orbital bone structure). In this way, the navigation system can determine the difference between the actual position of the physical implant relative to the patient's anatomy and the planned position of the model of the implant relative to the model of the patient's anatomy.

[0078] In fifth block 2508, the operations 2500 may optionally include adjusting one or more of the orbital implant shape or the orbital implant position during surgery according to the corresponding difference indication. For example, based on the information provided in fourth block 2506, the user may adjust the implant to more closely match the planned model of the implant and / or the position of the implant to the planned position (e.g., virtual position) of the implant.

[0079] 26 is a schematic diagram illustrating a conceptual embodiment of a navigation system 2600 having a stylus 2608. The system 2600 can be used in conjunction with preoperative images from imaging (e.g., computed tomography (CT) scans, 3D and / or 2D fluoroscopy, ultrasound (US) images, magnetic resonance imaging (MRI)), etc., to perform image-guided surgical procedures. The system 2600 includes at least an electronic processing unit 2606, a screen unit 2602, at least one tracked instrument 2608, such as a stylus, and an infrared sensor 2610. The system 2600 further includes one or more trackers (e.g., a rigidly mounted tracker 2612 attached to the patient's anatomy 2616, and optionally another tracker 2614 attached to the stylus 2608). The instrument 2608 and tracker 2612 / 2614 can be easily detected by an infrared sensor 2610, and the navigation system can include markers that allow the instrument 2608 and tracker 2612 / 2614 to be located in space.

[0080] The electronic processing device 2606 may be, for example, a personal computer or the like. The electronic processing device 2606 includes at least a processor and memory (e.g., a non-transitory computer-readable medium). The memory (not shown) may be, for example, random access memory (RAM), a memory buffer, a hard drive, read-only memory (ROM), erasable programmable read-only memory (EPROM), or the like. In some embodiments, the memory of the electronic processing device 2606 stores instructions that cause the processor to perform operations (e.g., operation 2500 of FIG. 25 ) and / or functions related to using personal computer applications, controlling one or more medical devices such as a stylus, displaying and updating images on the screen unit 2602 according to stylus movements, and / or the like.

[0081] The processor (not shown) of the electronic processing device 2606 may be any suitable processing device configured to execute and / or execute a set of instructions or code. For example, the processor may be a general-purpose processor, a central processing unit (CPU), an accelerated processing unit (APU), etc. In some embodiments, the processor of the electronic processing device 2606 may be included in, for example, an application-specific integrated circuit (ASIC). The processor may be configured to execute and / or execute instructions (e.g., operation 2500 shown in FIG. 25 ) or a set of code stored in an associated memory using a personal computer application, a mobile application, an internet web browser, telephone or cellular communication, etc.

[0082] The screen unit 2602 is configured to be in electronic communication with the electronic processing device 2606. The screen 2602 unit may be any suitable screen configured to provide a user interface to the electronic processing device 2606. For example, the screen unit 2602 may be a cathode ray tube (CRT) monitor, a liquid crystal display (LCD) monitor, a light emitting diode (LED) monitor, a head-mounted device, etc. The screen unit 2602 may be configured to provide a user interface for personal computer applications, etc. For example, the screen unit 2602 may be configured to graphically represent medical images of anatomical structures. In some embodiments, the screen unit 2602 may graphically represent the position of one or more medical instruments (e.g., a stylus 2608 and / or any other suitable device) relative to the target tissues (e.g., organs and / or skeleton) of the patient and as the medical instruments are positioned relative to pre-operative images or models of the target tissues. In some embodiments, the processing unit 2606 can be configured to map the movement of the stylus 2608 relative to the pre-operative image of the target tissue, and the screen unit 2602 can graphically represent the virtual position of the stylus 2608 relative to the image of the target tissue. The processing unit 2606 can determine the position of the stylus 2608 relative to the target tissue.

[0083] The electronic processing device 2606 may be configured to electronically communicate with the stylus 2608 (e.g., via a wireless connection, an Ethernet cable, a Universal Serial Bus (USB), a SATA cable, an eSATA cable, etc.). The stylus 2608 may be any suitable instrument configured to be tracked by a tracking system (e.g., optical tracking, or other modality). For example, an infrared light emitting diode (IRED) may be used to map the position of the stylus 2608 in physical space onto a virtual coordinate system and pre-operative images.

[0084] Example Embodiments Example embodiments are described in the following numbered sections, which relate to implants and methods involving implants. Those skilled in the art will readily understand that they may relate to orbital implants or other types of implants.

[0085] (Aspect 1) An implant for correcting a defect in a bone structure, comprising: a first surface including a shape configured to interface with a surface of the bone structure; and a second surface opposite the first surface and substantially conforming to the shape of the first surface, the second surface comprising three or more point features on the second surface, the three or more point features including a first point feature, a second point feature, and a third point feature that form triangular nodes, each of the three or more point features being recessed below the second surface.

[0086] (Aspect 2) An implant described in Aspect 1, wherein at least one of the three or more point features includes a hole that penetrates the implant from the first surface to the second surface.

[0087] (Aspect 3) An implant described in any one of aspects 1 and 2, wherein at least one of the three or more point features includes a recess configured to receive the tip of a stylus at an angle close to a tangent to the second surface.

[0088] (Aspect 4) An implant according to Aspect 3, wherein the depression is a wedge-shaped or elongated depression.

[0089] (Embodiment 5) An implant described in any one of embodiments 1 to 4, further comprising a raised ridge on the second surface that partially surrounds at least one of the three or more point features.

[0090] (Aspect 6) An implant described in Aspect 5, wherein the raised ridge surrounds at least one of the three or more point features distally.

[0091] (Aspect 7) An implant described in either aspect 5 or 6, wherein the raised ridge continues to the distal edge of the second surface.

[0092] (Aspect 8) An implant described in any one of aspects 5 to 7, wherein the raised ridge is at least one of three or more point features, including at least one of a corner, a hook, a notch, or a gap.

[0093] (Aspect 9) An implant as described in Aspect 8, wherein the corner, hook, notch, or gap is configured to receive the tip of a stylus angled substantially tangentially relative to the second surface.

[0094] (Aspect 10) An implant described in any one of aspects 5 to 9, wherein the raised ridge extends from a first point feature of the three or more point features to a second point feature of the three or more point features.

[0095] (Embodiment 11) An implant described in any one of embodiments 5 to 10, further comprising another raised ridge on the second surface, the another raised ridge extending from a second point feature to a third point feature of the three or more point features.

[0096] (Aspect 12) An implant as described in Aspect 11, wherein the raised ridge and the other raised ridge form a continuous ridge on the second surface.

[0097] (Aspect 13) An implant according to any one of aspects 5 to 12, wherein the raised ridge comprises a plurality of protrusions on the sides of the raised ridge.

[0098] (Aspect 14) An implant as described in Aspect 13, wherein the side surface is the distal side of the raised ridge.

[0099] (Embodiment 15) An implant described in any one of embodiments 5 to 14, further comprising a gradual transition on the side of the raised ridge from the top of the raised ridge to the second surface.

[0100] (Aspect 16) An implant as described in Aspect 15, wherein the side surface is the distal side of a raised ridge.

[0101] (Aspect 17) An implant described in any one of aspects 5 to 16, wherein the raised ridge includes a concave surface for receiving the tip of a stylus.

[0102] (Aspect 18) An implant as described in Aspect 17, wherein the concave surface is on the proximal side of the raised ridge.

[0103] (Embodiment 19) An implant described in any one of embodiments 1 to 4, further comprising one or more raised ridges extending along a path between a first point feature of the three or more point features and a second point feature of the three or more point features, each of the one or more raised ridges being located on a first side of the path and not on a second side of the path.

[0104] (Aspect 20) An implant according to Aspect 19, wherein the first side of the pathway is the distal side of the pathway.

[0105] (Embodiment 21) An implant described in any one of embodiments 1 to 20, further comprising a plurality of perforations extending through the implant from the first surface to the second surface.

[0106] (Aspect 22) An implant as described in Aspect 21, wherein the path between a first point feature of the three or more point features and a second point feature of the three or more point features does not include multiple perforations.

[0107] (Aspect 23) A method for correcting a defect in a patient's bone structure, the method comprising: positioning a first surface of an implant over the defect in the bone structure, the first surface including a shape configured to interface with the surface of the bone structure, and a second surface opposite the first surface and substantially conforming to the shape of the first surface, the second surface including three or more point features on the second surface, the three or more point features including a first point feature, a second point feature, and a third point feature that form nodes of a triangle, each of the three or more point features being elevated above the second surface or depressed below the second surface; and tracing a stylus of a navigation system along the second surface until the stylus is received by each of the three or more point features to compare one or more of (i) the shape of the implant to a planned shape of the implant, or (ii) the position of the implant in the patient to a planned position of the implant in the patient.

[0108] (Aspect 24) The method described in aspect 23, further comprising the steps of loading a virtual 3D implant model into a navigation system and aligning the virtual 3D implant model and the bone structure in a common coordinate system.

[0109] (Aspect 25) A method described in any one of aspects 23 and 24, further comprising a step of loading a virtual 3D anatomical model into a navigation system, wherein the step of bringing the virtual 3D implant model and the bone structure into a common coordinate system includes a step of registering the patient's anatomical features with the anatomical features of the virtual 3D anatomical model, and a step of maintaining the relative positions of the virtual 3D implant model and the virtual 3D anatomical model.

[0110] (Aspect 26) A method described in any one of aspects 23 to 25, further comprising a step of receiving an indication of a difference between one or more of: (i) the shape of the implant relative to the virtual 3D implant model, or (ii) the position of the implant in the patient relative to the position of the virtual 3D implant model relative to the patient.

[0111] (Aspect 27) The method described in Aspect 26, further comprising a step of adjusting one or more of the implant shape or implant position during surgery according to the indication of the difference.

[0112] (Embodiment 28) A method described in any one of embodiments 23 to 27, wherein at least one of the three or more point features is configured to accept a stylus tip that is at an angle close to a tangent to the second surface.

[0113] (Aspect 29) A method described in any one of aspects 23 to 28, wherein at least one of the three or more point features includes a wedge-shaped or elongated depression.

[0114] (Aspect 30) A method described in any one of aspects 23 to 29, wherein at least one of the three or more point features is partially surrounded by a raised ridge.

[0115] (Embodiment 31) The method described in embodiment 31, wherein the raised ridge at least partially surrounds at least one of the three or more point features on the distal side of at least one of the three or more point features.

[0116] (Aspect 32) A method described in any of aspects 30 and 31, wherein the raised ridge is at least one of three or more point features for accepting the tip of a stylus of a navigation system, and includes a corner, hook, notch, or gap.

[0117] (Aspect 33) A method described in any of aspects 23 to 32, wherein the implant includes a raised ridge, and the step of tracing the stylus of the navigation system along the second surface until the stylus is received by each of the three point features further includes the steps of sliding the tip of the stylus along the second surface until it hits the raised ridge, and sliding the tip of the stylus along the raised ridge until the tip of the stylus is received by at least one of the three point features.

[0118] (Aspect 34) A method for generating an implant for correcting a defect in a bone structure, the method comprising the steps of receiving a design of the implant indicating the shape, size, and position of the implant relative to a corresponding build area in an additive manufacturing device, and causing manufacture of the implant using additive manufacturing, wherein the design of the implant defines a first surface including a shape configured to interface with a surface of the bone structure, and a second surface opposite the first surface and substantially conforming to the shape of the first surface, the second surface comprising three or more point features on the second surface, the three or more point features comprising a first point feature, a second point feature, and a third point feature that form triangular nodes, each of the three or more point features being at least one of raised above the second surface or recessed below the second surface.

[0119] (Embodiment 35) The method described in embodiment 34, wherein at least one of the three or more point features comprises a hole that penetrates the implant from the first surface to the second surface.

[0120] (Aspect 36) A method described in any of aspects 34 and 35, wherein at least one of the three or more point features includes a recess configured to accept the tip of a stylus at an angle close to a tangent to the second surface.

[0121] (Aspect 37) The method described in Aspect 36, wherein the depression is a wedge-shaped or elongated depression.

[0122] (Embodiment 38) A method described in any of embodiments 34 to 37, wherein the implant design further defines a raised ridge on the second surface that partially surrounds at least one of the three or more point features.

[0123] (Embodiment 39) The method described in embodiment 38, wherein the raised ridge partially surrounds at least one of the three or more point features on the distal side.

[0124] (Aspect 40) A method described in any of aspects 38 and 39, wherein the raised ridge continues to the distal edge of the second surface.

[0125] (Aspect 41) A method described in any of aspects 38 to 40, wherein the raised ridge is at least one of three or more point features, including at least one of a corner, a hook, a notch, or a gap.

[0126] (Aspect 42) The method described in aspect 41, wherein the corner, hook, notch, or gap is configured to accept a tip of a stylus angled substantially tangentially to the second surface.

[0127] (Example 43) A method described in any of Examples 38 to 42, wherein the raised ridge extends from a first point feature of the three or more point features to a second point feature of the three or more point features.

[0128] (Aspect 44) A method described in any one of aspects 38 to 43, wherein the implant design further defines another raised ridge on the second surface, the other raised ridge extending from the second point feature to the third point feature of the three or more point features.

[0129] (Aspect 45) The method described in aspect 44, wherein the raised ridge and other raised ridges form a continuous raised line on the second surface.

[0130] (Aspect 46) A method described in any of aspects 38 to 45, wherein the implant design further defines multiple protrusions on the sides of the raised ridge.

[0131] (Aspect 47) The method described in aspect 46, wherein the side is the distal side of the raised ridge.

[0132] (Embodiment 48) A method described in any of embodiments 38 to 47, wherein the implant design further defines a smooth transition on the side of the raised ridge from the top of the raised ridge to the second surface.

[0133] (Aspect 49) The method described in aspect 48, wherein the side is the distal side of the raised ridge.

[0134] (Embodiment 50) A method described in any of embodiments 34 to 37, wherein the implant design defines one or more raised ridges on one side of a path between a first point feature of the three or more point features and a second point feature of the three or more point features.

[0135] (Embodiment 51) The method described in embodiment 50, wherein one side of the pathway is the distal side of the pathway.

[0136] (Embodiment 52) ​​A method described in any of embodiments 34 to 37, wherein the implant design further defines a raised ridge including a concave surface for receiving the tip of a stylus.

[0137] (Aspect 53) The method described in Aspect 52, wherein the concave surface is on the proximal side of the raised ridge.

[0138] (Embodiment 54) A method described in any of embodiments 34 to 37, wherein the implant design further defines a plurality of perforations extending through the implant from the first surface to the second surface.

[0139] (Aspect 55) The method described in Aspect 54, wherein the implant design does not define any of the multiple perforations along a path between a first point feature of three or more point features and a second point feature of three or more point features.

[0140] (Aspect 56) A method described in any of aspects 34 to 37, further comprising the steps of receiving a digital file containing the implant design and loading the digital file into a navigation system.

[0141] (Aspect 57) The method described in aspect 56, wherein the digital file further includes data indicating the position of each of the three or more point features.

[0142] (Aspect 58) The method described in aspect 57, wherein the data indicating the position is data indicating the planned position of the implant relative to the patient's anatomical structure.

[0143] (Aspect 59) The method described in aspect 58, wherein the data indicating the planned position of the implant includes a virtual 3D representation of at least a portion of the patient's anatomy, and data indicating the position of each of three or more point features of the implant relative to the patient's anatomy.

[0144] [Additional Considerations] Various embodiments disclosed herein provide for the use of computer-controlled devices. Those skilled in the art will readily appreciate that these embodiments can be implemented using many different types of computing devices, including both general-purpose and / or special-purpose computing system environments or configurations. Examples of well-known computing systems, environments, and / or configurations that may be suitable for use in connection with the above-described embodiments may include, but are not limited to, personal computers, server computers, handheld or laptop devices, multiprocessor systems, microprocessor-based systems, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments (e.g., networks, cloud computing systems, etc.) that include any of the above systems or devices, and the like. These devices may include stored instructions that, when executed by a microprocessor within the computing device, cause the computing device to perform specified actions and execute the instructions. As used herein, instructions refer to computer-implemented steps for processing information within a system. Instructions may be implemented in software, firmware, or hardware and may include any type of programmed steps performed by components of the system.

[0145] The microprocessor may be any conventional general-purpose single- or multi-chip microprocessor, such as a Pentium® processor, a Pentium® Pro processor, an 8051 processor, a microprocessor without interlocked pipeline stages (MIPS®) processor, a Power PC® processor, or an Alpha® processor. Additionally, the microprocessor may be any conventional special-purpose microprocessor, such as a digital signal processor or a graphics processor. Microprocessors typically have conventional address lines, conventional data lines, and one or more conventional control lines.

[0146] Aspects and embodiments disclosed herein may be implemented using standard programming or engineering techniques to produce software, firmware, hardware, or any combination thereof. As used herein, the term "article of manufacture" refers to code or logic embodied in hardware or a non-transitory computer-readable medium, such as optical storage devices, and volatile or non-volatile storage devices, or transitory computer-readable media such as signals, carrier waves, etc. Such hardware may include, but is not limited to, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), complex programmable logic devices (CPLDs), programmable logic arrays (PLAs), microprocessors, or other similar processing devices.

Claims

1. 1. An implant for correcting defects in bone structure, said implant comprising: a first surface including a shape configured to interface with a surface of the bone structure; and a second surface opposite the first surface and substantially conforming to the shape of the first surface; The second surface is three or more point features on the second surface; the three or more point features include a first point feature, a second point feature, and a third point feature that form nodes of a triangle, each of the three or more point features being recessed below the second surface; at least one of the three or more point features includes a recess configured to receive a tip of a stylus at a near tangential angle with respect to the second surface; The implant, wherein the depression is a wedge-shaped or elongated depression.

2. The implant of claim 1 , wherein at least one of the three or more point features comprises a hole extending through the implant from the first surface to the second surface.

3. The implant of claim 1 , further comprising a raised ridge on the second surface partially surrounding a most distal point feature of the three or more point features.

4. The implant of claim 3 , wherein the raised ridge distally surrounds the at least one of the three or more point features.

5. 5. The implant of claim 3 or 4, wherein the raised ridge continues to a distal edge of the second surface.

6. 5. The implant of claim 3 or 4, wherein the raised ridge comprises at least one of a corner, a hook, a notch, or a gap at the at least one of the three or more point features.

7. The implant of claim 6 , wherein the corner, hook, notch, or gap is configured to receive a tip of a stylus angled substantially tangentially to the second surface.

8. 5. The implant of claim 3 or 4, wherein the raised ridge extends from a first one of the three or more point features to a second one of the three or more point features.

9. 9. The implant of claim 8, further comprising another raised ridge on the second surface, the other raised ridge extending from the second one of the three or more point features to a third one of the three or more point features.

10. The implant of claim 9 , wherein the raised ridge and the further raised ridge form a continuous ridge on the second surface.

11. 5. The implant of claim 3 or 4, wherein the raised ridge includes a plurality of protrusions on the sides of the raised ridge.

12. The implant of claim 11 , wherein the side surface is a distal side of the raised ridge.

13. 5. The implant of claim 3 or 4, further comprising a gradual transition on a side of the raised ridge from the top of the raised ridge to the second surface.

14. 14. The implant of claim 13, wherein the side surface is a distal side of the raised ridge.

15. 5. An implant according to claim 3 or 4, wherein the raised ridge includes a concave surface for receiving the tip of a stylus.

16. 16. The implant of claim 15, wherein the concave surface is proximal to the raised ridge.

17. 5. The implant of claim 1, further comprising one or more raised ridges extending along a path between a first one of the three or more point features and a second one of the three or more point features, each of the one or more raised ridges being located on a first side of the path and not on a second side of the path.

18. 18. The implant of claim 17, wherein the first side of the passageway is a distal side of the passageway.

19. The implant of any one of claims 1 to 4, further comprising a plurality of perforations extending through the implant from the first surface to the second surface.

20. Between a first point feature of the three or more point features and a second point feature of the three or more point features 20. The implant of claim 19, wherein the pathway does not include the plurality of perforations.

Images