Apparatus and method for measuring intervertebral loads - Patent Application 20070122997

Abstract

This embodiment provides an adjustable cage template for determining a cage for use in a spine procedure. The adjustable cage template may include an upper cage template, a lower cage template, and a control support. The configuration of the cage template may be altered, and sensors may measure forces applied to the cage template during the alteration. The alteration of the cage template may include rotation of the upper cage template relative to the lower cage template, vertical movement of the upper cage template relative to the lower cage template, or both rotation and vertical movement of the upper and lower cage templates. Information related to the measurements from the sensors may be output to determine whether the current configuration of the cage template is optimal, and a final cage template for the spine procedure may be selected based at least in part on the output information.

Description

[Technical Field]

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 440,183, filed January 20, 2023, entitled "Devices and Methods for Measuring Intervertebral Loading," the contents of which are incorporated herein by reference in their entirety. [Background technology]

[0002] The present application discloses systems and methods for performing spinal fusion procedures, and more particularly, for measuring intervertebral loads during placement of medical devices in the spine.

[0003] Intervertebral body spacers are commonly used in the spine. Intervertebral body spacers, also known as cages, are medical devices that can be used for intervertebral body fusion of the spine. For example, these medical devices can be used in skeletally mature patients who have undergone at least six months of non-surgical treatment. They are designed for use with allografts, consisting of cancellous bone and / or corticocancellous bone grafts and / or autogenous bone grafts, to promote fusion. In practice, one device is used per intervertebral body space. These devices are intended for use in the treatment of degenerative disc disease (DDD) associated with up to grade I spondylolisthesis at one or two consecutive levels in the lumbar spine, from L2 to S1. DDD is defined as discogenic low back pain with confirmed disc degeneration confirmed by medical history and radiological examination. However, intervertebral body space devices may also be designed for use at other levels of the spine, such as the cervical spine.

[0004] Subsidence is a complication of spinal fusion surgery, resulting in a loss of vertical height in the intervertebral space before complete fusion (e.g., two levels or two vertebrae have been fused). During fusion, surgeons attempt to restore vertical height using intervertebral spacers or cages. However, two forces prevent full restoration of height. First, when autogenous or allogeneic bone is used within the disc space, compression forces are applied to the bone by gravity or the use of posterior fixation, causing the vertebral body to "compress" against the bone graft. Based on a concept known as Wolff's Law, bone can remodel under compressive forces. Therefore, most surgeons apply a slight load to the bone graft. This load can reduce the effective vertical height of the surgical level. Further subsidence of the intervertebral cage into the cortical bone at the cage-vertebral body interface can further reduce effective height because the cage has stiffer material properties than the surrounding bone structure, causing the bone to yield. Most surgeons believe that this subsidence and "settlement" due to the weight of the graft occurs, and that the loss of intervertebral space height is compensated for by other vertebral anatomy as the patient heals. However, excessive loss of height can lead to nonfusion of the bone graft, cage fracture, or symptoms of adjacent vertebral disease.

[0005] One cause of subsidence is "excessive traction" that occurs when surgeons select an implant that fits the disc space and restores the appropriate height through trial insertion. However, currently available trial insertion procedures attempt to seat the implant in a way that places excessive traction forces on the vertebral endplates. This occurs when surgeons intentionally select an implant that is larger than the final try-in size that fit, or when they select an implant with additional features, such as teeth or a roughened, porous surface, compared to the try-in implant. As a result, surgeons force the final implant into the endplates, weakening the underlying bone through excessive traction forces, essentially causing subsidence. Therefore, while current techniques are capable of inserting an intervertebral cage into the appropriate space between two vertebrae, they suffer from drawbacks related to subsidence, which can reduce the clinical success of the fusion process.

[0006] U.S. Patent No. 9,839,374 (hereinafter, the "'374 Patent"), entitled "Spinal Load and Position Detection System and Method," describes a load balancing and alignment system using a spinal instrument with an electronic assembly and a sensor-equipped head. The system reports vertebral body conditions such as force, pressure, direction, and edge load, and also provides a GUI that shows the position of the spinal instrument relative to the vertebral bodies when the instrument is positioned in the intervertebral space. However, the '374 Patent does not describe using the electronic assembly and sensor-equipped head to determine the appropriate implant size for intervertebral spacers, such as cages used in spinal fusion procedures. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Patent No. 9,839,374 Summary of the Invention [Problem to be solved by the invention]

[0008] This embodiment provides an adjustable cage template for determining the cage to use in spinal surgery. [Means for solving the problem]

[0009] The adjustable cage template can include an upper cage template, a lower cage template, and a control support. The configuration of the cage template can be altered, and sensors can measure forces applied to the cage template during alterations of the cage template configuration. Altering the cage template can include rotating the upper cage template relative to the lower cage template, vertically translating the upper cage template relative to the lower cage template, or both rotating and vertically translating the upper and lower cage templates. Information regarding the measurements from the sensors can be output to determine whether the current configuration of the cage template is optimal, and a final cage template for the spine surgery can be selected based at least in part on the output information.

[0010] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the following detailed description may be better understood. Additional features and advantages will be described hereinafter which form the subject matter of the claims. Those skilled in the art will appreciate that the conception and specific embodiments disclosed may readily be utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present application. Those skilled in the art will also appreciate that such equivalent constructions do not depart from the spirit and scope of the present application as set forth in the appended claims. The novel features believed characteristic of the embodiments described herein, both their organization and method of operation, together with further objects and advantages, will be better understood by reference to the following description in conjunction with the accompanying drawings. It is to be expressly understood, however, that each figure is provided for the purpose of illustration and description only and is not intended to define the limitations of the present embodiments.

[0011] For a more detailed understanding, please refer to the following description taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a block diagram of a system for determining an optimal cage in a spinal fusion procedure, according to aspects of the present disclosure. [Figure 2A] FIG. 1 is a block diagram illustrating an exemplary embodiment for determining an optimal cage for a spinal fusion procedure, according to aspects of the present disclosure. [Figure 2B] FIG. 1 is a block diagram illustrating an exemplary embodiment for determining an optimal cage for a spinal fusion procedure, according to aspects of the present disclosure. [Figure 2C] FIG. 1 is a block diagram illustrating an exemplary embodiment for determining an optimal cage for a spinal fusion procedure, according to aspects of the present disclosure. [Figure 3A] FIG. 1 is a block diagram illustrating an exemplary sizing tool, according to aspects of the present disclosure. [Figure 3B] 1 is a block diagram illustrating exemplary features of a cage template, according to aspects of the present disclosure. FIG. [Figure 3C] 1 is a block diagram illustrating exemplary features of a cage template, according to aspects of the present disclosure. FIG. [Figure 3D] 1 is a block diagram illustrating exemplary features of a cage template, according to aspects of the present disclosure. FIG. [Figure 3E] 1 is a block diagram illustrating exemplary features of a cage template, according to aspects of the present disclosure. FIG. [Figure 3F] 1 is a block diagram illustrating exemplary features of a cage template, according to aspects of the present disclosure. FIG. [Figure 3G] 1 is a block diagram illustrating exemplary features of a cage template, according to aspects of the present disclosure. FIG. [Figure 3H] 1 is a block diagram illustrating exemplary features of a cage template, according to aspects of the present disclosure. FIG. [Figure 4A] 10A-10C illustrate various views of a cage template and mechanical interface for cage sizing, according to an aspect of the present disclosure. [Figure 4B] 10A-10C illustrate various views of a cage template and mechanical interface for cage sizing, according to an aspect of the present disclosure. [Figure 4C]10A-10C illustrate various views of a cage template and mechanical interface for cage sizing, according to an aspect of the present disclosure. [Figure 4D] 10A-10C illustrate various views of a cage template and mechanical interface for cage sizing, according to an aspect of the present disclosure. [Figure 5] 1 is an image of a cage template according to an aspect of the present disclosure. [Figure 6A] 10A-10C are block diagrams illustrating further aspects of a cage and a cage template according to aspects of the present disclosure. [Figure 6B] 10A-10C are block diagrams illustrating further aspects of a cage and a cage template according to aspects of the present disclosure. [Figure 6C] 10A-10C are block diagrams illustrating further aspects of a cage and a cage template according to aspects of the present disclosure. [Figure 6D] 10A-10C are block diagrams illustrating further aspects of a cage and a cage template according to aspects of the present disclosure. [Figure 6E] 10A-10C are block diagrams illustrating further aspects of a cage and a cage template according to aspects of the present disclosure. [Figure 6F] 10A-10C are block diagrams illustrating further aspects of a cage and a cage template according to aspects of the present disclosure. [Figure 6G] 10A-10C are block diagrams illustrating further aspects of a cage and a cage template according to aspects of the present disclosure. [Figure 6H] 10A-10C are block diagrams illustrating further aspects of a cage and a cage template according to aspects of the present disclosure. [Figure 6I] 10A-10C are block diagrams illustrating further aspects of a cage and a cage template according to aspects of the present disclosure. [Figure 7] FIG. 1 is a flow diagram of an exemplary method for determining an optimal cage for a spinal fusion procedure, according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] (Detailed explanation) Referring to FIG. 1 , a block diagram of a system for determining intervertebral loads associated with placement of a medical device on the spine according to an embodiment of the present disclosure is shown as system 100. As described in more detail below, system 100 may be utilized to determine intervertebral loads associated with placement of a medical device on the spine, such as an optimal cage for use in a spinal fusion procedure. The optimal cage may be determined to provide adequate support across a particular bony structure (e.g., a bony structure rather than a cartilaginous structure) and have dimensions appropriate for the space between two different vertebral body segments. Exemplary details regarding such optimization are described in more detail below with reference to FIGS. 2A-6I.

[0014] As shown in FIG. 1 , system 100 includes a sizing tool 110 having a housing 112, one or more mechanical systems 114, one or more cages (e.g., one or more intervertebral body spacers or cages), one or more sensors 118, input / output (I / O) devices 120, and one or more communication interfaces 122. The housing 112 may be formed from a metal, such as titanium, aluminum, stainless steel, or other metal suitable for medical applications. In one embodiment, the housing 112 may be formed from a non-metallic material, such as a plastic, suitable for use in medical procedures. Forming the housing 112 from a metallic material facilitates sterilization (e.g., autoclaving) of the sizing tool 110, although any suitable sterilizable material may be utilized for the housing 112 (or other components of the sizing tool 110). Additionally or alternatively, the sizing tool 110 may be fabricated as a disposable device suitable for use in a single surgical procedure and then discarded.

[0015] The mechanical system 114 may be configured to manipulate one or more cages 116 in a sizing and placement procedure that may be performed prior to performing a spinal fusion procedure. For example, the mechanical system 114 may include gears, drive shafts, transmission gears, and other mechanisms to rotate, translate, or otherwise move one or more cages 116 into different positions to determine the optimal cage for a particular spinal procedure. See Figures 2A-2E for an example of determining the optimal cage for a spinal fusion procedure. Figures 2A-3C show vertebral segments 202, 204 with an intervertebral spacer or cage 222 positioned in the space between each vertebral segment 202, 204.

[0016] In FIG. 2A , the cage 222 is tapered (e.g., from left to right in FIG. 2A ), and while the left portion of FIG. 2A is properly sized (e.g., supporting both vertebrae 202, 204), a gap 224 exists between the tapered end of the cage 222 and the vertebrae 202, 204. In this situation, subsidence can occur because the two vertebrae 202, 204 are not fully supported, resulting in improper compression forces between the vertebrae 202, 204 and the cage 222. In other words, in FIG. 2A , the cage 222 has the proper height, at least with respect to the left end of the cage 222 ( FIG. 2A ), but the gap 224 exists because the lordotic angle of the cage 222 is improper. Similarly, in FIG. 2B , a gap 224 exists between the cage 222 and the vertebra 202 (on the right side of the figure) due to a mismatch in the lordotic angle between the bottom of the vertebra 202 and the top surface of the cage 222. Thus, the cage 222 shown in Figure 2B is a poor implant choice due to the mismatched lordotic angle. In contrast, Figure 2C shows cage 222 with the appropriate implant height and lordotic angle, making it the optimal cage choice for a particular spinal procedure.

[0017] As is evident from the foregoing description, selecting a cage configured with an appropriate size and shape can play a critical role in the success of a spinal fusion procedure. The sizing tool 110 can be used to determine the appropriate size and shape of the cage for a particular spinal procedure. For example, the cage 116 can include a cage and cage end plates. The cage corresponds to an intervertebral device suitable for use in performing a spinal procedure, such as a spinal fusion procedure, and the cage end plates can correspond to a measuring device configured to measure the size and dimensions of the intervertebral space. This allows for the identification of a cage of the appropriate size and dimensions for the intervertebral space targeted in the medical procedure. For example, the cage end plates can be attached to the sizing tool 110 and manipulated via the mechanical system 114 to adjust the lordotic angle of the cage end plates to match the lordotic angle of the intervertebral space. For example, the cage end plates can include upper and lower plates that can be manipulated via the mechanical system. Such manipulation can include moving the upper and lower plates apart or toward each other while maintaining them parallel or substantially parallel to increase the set intervertebral height. This manipulation may also include adjusting the angle of the upper and / or lower plates relative to one another, such as increasing the lordotic angle of the upper plate, the lordotic angle of the lower plate, or both. Exemplary movements and manipulations that may be achieved using the mechanical systems and cage end plates disclosed herein are described in more detail below.

[0018] The sensors 118 are configured to measure the forces applied to the cage template from the upper and lower vertebrae, which can be used to determine whether the cage having the size and dimensions of the cage endplate provides adequate compression. The sensors 118 can also quantify the distribution of the compressive force, for example, determining whether the compressive force is evenly distributed across the surface of the cage endplate, which indicates that the compressive force can be evenly distributed across the surface of the cage corresponding to the cage endplate configuration. As described in more detail below, the one or more sensors 118 can include pressure sensors, strain gauges, or other types of sensors configured to measure the forces applied to the cage endplate. Furthermore, the sensors 118 can include other types of sensors, such as sensors configured to measure the forces applied to the cage endplates, as well as sensors configured to measure the magnitude of the forces applied by the mechanical system 114 when manipulating the cage endplate configuration.

[0019] Input / output device 120 may provide support for transmitting measurements from sensor 118 to a remote device, shown in Figure 1 as computing device 140. As shown in Figure 1, computing device 140 may include one or more processors 142, memory 144, one or more communication interfaces 150, and one or more input / output devices 152. Memory 144 may include random access memory (RAM) devices, read-only memory (ROM) devices, erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), one or more hard disk drives (HDDs), one or more solid state drives (SSDs), flash memory devices, network accessible storage (NAS) devices, or other memory devices configured to store data persistently or non-persistently. Software configured to facilitate the operation and functionality of computing device 140 may be stored in memory 144 as instructions 146 that, when executed by one or more processors 142, may cause the one or more processors 142 to perform operations associated with computing device 140 as described herein, such as displaying data acquired by one or more sensors 118. One or more databases 148 may also be stored in memory 140. For example, sensor data acquired by sensors 118 of a sizing tool may be stored in database 148.The one or more communication interfaces 150 may be configured to communicatively connect the computing device 140 to the sizing tool 110 via a wired communication link, or via a wired or wireless communication link via the one or more networks 130, or via a wired or wireless communication link established in accordance with one or more communication protocols or standards (e.g., an Ethernet protocol, a Transmission Control Protocol / Internet Protocol (TCP / IP) Institute of Electrical and Electronics Engineers (IEEE) 802.11 protocol, an IEEE 802.16 protocol, a third-generation (3G) communication standard, a fourth-generation (4G) / Long Term Evolution (LTE) communication standard, a fifth-generation (5G) communication standard, etc.). The one or more input / output devices 152 may include one or more display devices, a keyboard, a stylus, one or more touchscreens, a mouse, a trackpad, a camera, one or more speakers, a haptic feedback device, or other types of devices that enable a user to receive information from or provide information to the computing device 140.

[0020] In one embodiment, the measurements may be taken by a sensor and transmitted over a set of wires, hi another or alternative embodiment, the measurements may be taken by sensor 118 and transmitted over one or more networks to computing device 140 via a wireless communication link.

[0021] As an illustrative example, FIG. 3A shows a block diagram of an exemplary sizing tool according to an embodiment of the present disclosure, depicted as sizing tool 300. As shown in FIG. 3A, sizing tool 300 includes a housing having a body 330. Body 300 may include one or more mechanical system interfaces, depicted in FIG. 3A as mechanical system interfaces 310, 320. Mechanical system interfaces 310, 320 may be configured to enable manipulation and configuration of a cage template 340 attached to a distal end 340 of sizing tool 300. As described above, cage template 340 may include a sensor 360 that may be communicatively connected to computing device 140 via a wired or wireless connection. In the example shown in FIG. 3A, a wired connection is shown, with wire 362 running longitudinally through body 330 of sizing tool 300 from sensor 360 to computing device 140. It should be noted that a single continuous wire need not be used, and one or more extensions or connectors can be used to connect sensor 360 to computing device 140, if desired. For example, a portion of wire 362 can be hardwired within body 330, and a connector can be provided at the distal end of the sizing tool, i.e., near where cage template 340 is coupled to sizing tool 300. Similarly, a connector can be provided at the proximal end of sizing tool 300 to allow a wire or cable to be connected to computing device 140. In another or alternative embodiment, a longitudinal through-hole can be provided for routing wire 362, and one or more extensions can be connected to wire 362 after it exits the proximal end of sizing tool 300 (left side of FIG. 3A ). It should be noted that the above exemplary configurations are provided by way of illustration and not limitation, and that other configurations and arrangements can be utilized in accordance with the concepts described herein.

[0022] The computing device 140 may be configured to present one or more graphical user interfaces to allow the surgeon to view the sensor data and determine whether the proper cage template configuration has been achieved. For example, as described above, the sensor data acquired by the sensor 360 may be used to determine whether pressure or force is evenly distributed across the surface of the cage template 340. If the force is not evenly distributed, one or more mechanical interfaces 310, 320 of the sizing tool 300 may be manipulated to change the configuration of the cage template 340. As the configuration of the cage template 340 changes, the forces measured by the sensor 360 also change, allowing the surgeon to evaluate different configurations of the cage template 340 to find one that provides the optimal force distribution. In another aspect, the computing device 140 may display color-coded guidance when excessive pressure or force is measured, indicating that placing the cage in that position poses a high risk of subsidence, as described in more detail below. Exemplary configuration changes and manipulations that may be provided by one or more mechanical interfaces of the sizing tool according to aspects of the present disclosure are described in more detail below.

[0023] As briefly described above, one or more mechanical interfaces 310, 320 can be used to alter the configuration of the cage template. By way of non-limiting example, the cage interface 310 can be configured to facilitate movement of the upper plate, the lower plate, or both the upper and lower plates of the cage template. For illustrative purposes, with reference to FIGS. 3B-3H, block diagrams illustrating exemplary features of a cage template according to an embodiment of the present disclosure are shown. As shown in FIGS. 3C-3F, a cage template according to the present disclosure can include an upper cage template 342 and a lower cage template 348. As shown in FIGS. 3D-3F, a cage template can include an upper cage template 342 and a lower cage template 348. As shown in FIG. 3B, the upper cage template 342 and the lower cage template 348 can include sensors (e.g., sensor 360 in FIG. 3A) located on the periphery of the cage template 340 (shown as sensors 360A-360D). Locating sensors near the periphery and corners of the upper and lower plates of the cage template is beneficial in that it indicates whether forces are evenly distributed across the surfaces of upper cage template 342 and lower cage template 348. However, it should be noted that other configurations of sensors and cage templates are contemplated herein, as described in more detail with reference to FIGS. 6A-6I. As shown in FIG. 4B, portions of the upper and lower cage templates may be provided with recesses for locating sensors 360A-360D. The recesses may also include space for routing wires (e.g., wire 362 in FIGS. 3A and 3B) without compressing or damaging them when changing the configuration of the cage template.

[0024] 3C , upper cage template 342 may be supported by control support 344, and lower cage template 348 may be supported by control support 346. Control supports 344, 346 may be in mechanical communication with one or more mechanical systems 350 (e.g., one or more of mechanical systems 114 of FIG. 1 ) and interface with one or more mechanical interfaces 310, 320 of sizing tool 300 to facilitate changing the configuration of cage template 340. For example, in FIG. 3D , upper cage template 342 and lower cage template 348 may be moved in the direction indicated by arrow 302, such that upper cage template 342 moves vertically away from lower cage template 348, and lower cage template 348 moves vertically away from upper cage template 342. Note that in the exemplary change in cage configuration shown in FIG. 3D , upper cage template 342 and lower cage template 348 may be maintained parallel to one another during movement. However, the parallelism of the plates may change slightly as compressive forces are applied, such as when the upper and lower cage templates 342, 348 reach and begin to press against the associated vertebral segments. Additionally, while the above description refers to simultaneous movement of both the upper and lower cage templates, in one embodiment, the mechanical system 350 and control supports 344, 346 may be configured to limit movement to only the upper cage template 342 or only the lower cage template 348, as desired.

[0025] In addition to moving the upper and lower cage templates 342 and 348 as shown in FIG. 3D , other types of movements and changes to the configuration of the cage template 340 can be effected via the sizing tool 300 and cage template manipulation mechanical system (e.g., mechanical interfaces 310, 320 and control supports 344, 346). For example, in FIG. 3E , the proximal ends (left side of FIG. 3E ) of the upper and lower cage templates 242 and 248 can be rotated away from each other, while the distal ends of the upper and lower cage templates 242 and 248 remain close to each other. As shown in FIG. 3E , such movement creates an angle (θ) relative to the orientation of the upper and lower cage templates 342 and 348. In one embodiment, the control supports 344, 346 can be configured to limit the angle (θ), for example, limiting the angle (θ) to X° to Y°. In one embodiment, the angle (θ) (e.g., lordosis angle) can be in the range of 3° to 30°. In one embodiment, the angle (θ) may range from 7° to 20°. In one embodiment, the angle (θ) may range from 5° to 15°. In one embodiment, the angle (θ) may range from 9° to 22°. In one embodiment, the cage template may be limited to a threshold angle range achievable by the concepts described herein. In such cases, multiple cage templates may be provided that provide different portions of the potential angle range, e.g., in 3-5 degree increments, to cover the full range of potential angles (θ) in a particular region of the spine. Similar to the example of FIG. 3D, FIG. 3E shows both the upper and lower cage templates moving in response to manipulation of either machine interface 310, 320; however, in one embodiment, one of the upper and lower cage plates may be held relatively horizontal while the other is altered to generate the angle (θ).

[0026] As can be seen from the exemplary configuration changes shown in FIGS. 3D and 3E , the sizing tool's mechanical systems (e.g., mechanical interfaces 310, 320) and corresponding elements of the cage template (e.g., mechanical system 350 and control supports 344, 346) can enable various changes to the cage template configuration. In one embodiment, the sizing tool's mechanical interfaces 310, 320 can accommodate any of the operations or configuration changes shown in FIGS. 3D and 3E . For example, the mechanical interface 310 can be configured to rotate about the longitudinal axis of the body 330 to move the upper cage template 242 and / or the lower cage template 248 as shown in FIG. 3D . The mechanical interface 320 can also be configured to rotate about the longitudinal axis of the body 330 to change the configuration of the upper cage template 242 and / or the lower cage template 248 as shown in FIG. 3E . It should be noted that rotation of the mechanical interfaces 310, 320 can be used to reversibly change the configuration of the cage template and determine the optimal configuration. For example, if the mechanical interfaces 310, 320 are rotated in a first direction to determine the optimal configuration, the configuration change can be reversed by rotating the mechanical interfaces 310, 320 in the opposite direction, which may allow the sizing tool and cage template to be more easily removed from the patient. In one embodiment, markers can be placed on the exterior surface of the body 330 or other portions of the sizing tool to allow the surgeon to determine the final configuration of the cage template. Once the final configuration is determined, the surgeon can remove the sizing tool and cage template and partially or fully reverse the configuration change to return the cage template to its final configuration based on the markings recorded when the final configuration was identified. This allows the surgeon to compare the final configuration to one or more cages and identify the cage that matches or most closely matches the final configuration of the cage template.In additional or alternative embodiments, a table may be provided that includes configuration information based on markings on body 330 (or other portions of the sizing tool) and identifies one or more cage templates that most closely resemble the final configuration. For example, in Table 1 below, cage configuration information is shown in the left column and includes configuration X for machine interface 310 and configuration Y for machine interface 320. Thus, cage A may be selected from the kit if the markings on the cage template when it reaches its final configuration correspond to (X1, Y1). Similarly, cage B may be selected from the kit if the markings on the cage template when it reaches its final configuration correspond to (X2, Y2). And cage C may be selected from the kit if the markings on the cage template when it reaches its final configuration correspond to (X3, Y3).

[0027] [Table 1]

[0028] In one embodiment, a mechanical interface of a sizing tool according to the concepts described herein may be configured to provide incremental movements of the interface used to manipulate the cage configuration, for example, to provide a series of slidable teeth, as shown in FIG. 3I. The mechanical interface rotates, transitioning from state 370 to state 372 to state 374. Upon reaching state 374, the slidable teeth may come to rest between opposing teeth, producing a clicking sound. This clicking sound indicates that a single incremental movement has been achieved, and markers on body 330 or elsewhere on the sizing tool may track the number of incremental movements made during manipulation of the cage template configuration. For example, in Table 1 above, X corresponds to the number of clicks or incremental movements of mechanical interface 310, and Y corresponds to the number of clicks or incremental movements of mechanical interface 320. Thus, X corresponds to the final configuration. i , Y iIf is known, the surgeon can set the machine interface 310, 320 to X i , Y i The cage template can be returned to its final configuration by manipulating the

[0029] In one embodiment, multiple different cage template configuration changes can be applied simultaneously (e.g., by manipulating both interfaces 310, 320), as shown in Figure 3F. Figure 3F illustrates the movement of upper cage template 342 and lower cage template 348 as described with reference to Figure 3D, and the formation of angle (θ) as described with reference to Figure 3E. Note that additional movements, changes, and modifications to the cage template configuration can also be provided in accordance with the concepts described herein.

[0030] It should be noted that the sizing tool 300 can provide similar translation and configuration changes in different ways depending on the type of cage provided and the procedure used for cage insertion. For example, spinal fusion can be performed via a lateral approach (e.g., inserting the cage through an incision on the side of the patient's torso), an anterior approach (e.g., inserting the cage through an incision on the front of the patient's abdomen), or a posterior approach (e.g., inserting the cage through an incision on the patient's back). For a lateral approach, the sizing tool 300 and cage template 340 can be positioned as shown in FIG. 3G , and for anterior and posterior approaches, the sizing tool 300 and cage template 340 can be positioned as shown in FIG. 3H . It should be noted that while FIGS. 3G and 3H may appear to be simple rotations of each other, the mechanical systems can be configured differently to provide similar translations in these two configurations. For example, in FIG. 3G , the mechanical system of the sizing tool and cage template is configured to generate an angle (θ) that rotates the upper and / or lower cage templates parallel to the insertion direction. This is similar to the configuration shown in Figure 3E, except in this case, mechanical system 350 is positioned behind (from the perspective of Figure 3E) cage template 340. On the other hand, if an anterior or posterior approach is utilized, the angle (θ) may be formed perpendicular to the insertion direction shown in Figure 3H. Thus, there may be different sizing tools with different mechanical system configurations depending on the type of approach used in performing a particular spinal fusion procedure.

[0031] Once the appropriate configuration of the cage template has been determined (e.g., a configuration that distributes forces evenly across the upper and lower surfaces of the cage template based on sensor data), the sizing tool 300 and cage template 340 can be removed from the patient's body, and a cage with a configuration that closely matches or is equivalent to the final configuration of the cage template can be selected. For example, the sizing tool 300 can be part of a kit containing various cages for implantation into the patient. The cages in the kit may have different lordotic angles, heights, or other characteristics. After the appropriate configuration of the cage template has been identified, a sizing procedure in accordance with the concepts described herein can be used to reference the cages in the kit and identify a cage with a configuration that matches or is closest to the configuration of the cage template. Once the appropriate cage is selected, it can be inserted into the space between the patient's vertebral segments to aid in spinal fixation. For example, in the example shown in Figures 2A-2C, the selected cage may correspond to cage 222 shown in Figure 2C, rather than the cage shown in Figures 2A and 2B. If a satisfactory configuration is not achieved by manipulating the initial cage template, select a different cage template in the kit or a new kit containing a different cage template and repeat the configuration steps above to see if a more suitable cage configuration can be identified. If the sizing steps above do not identify the optimal cage, the closest-fitting cage from the kit may be selected.

[0032] Based on the sizing and configuration techniques described herein, an appropriately sized cage can be selected to evenly distribute compressive forces, thereby minimizing the potential for subsidence and promoting improved spinal fusion procedures. It should also be noted that the potential for subsidence can be minimized using other techniques. For example, the techniques described in PCT / US22 / 49515, filed April 11, 2023, entitled "Method and Apparatus for Reducing Human Vertebral Body Subsidence Using Variable Surface Area Interbody Cages Correlated to Localized Bone Density Measurements," can be used to select an initial cage template based on bone characteristics. This patent, the contents of which are incorporated herein by reference, provides information regarding the size and shape of a candidate cage that will support and be supported by the dense bone of a spinal segment, further reducing the potential for subsidence. Therefore, it should be appreciated that an initial candidate cage template can be selected based on the bone characteristics of the relevant vertebral segment, and then the sizing and configuration techniques described herein can be used to determine the optimal configuration of the cage ultimately used in the spinal fusion procedure. In one embodiment, after the cage is inserted into the space between the vertebral segments, one or more bone screws can be used to secure the cage in place.

[0033] 4A-4D, various views of a cage template and mechanical interfaces for performing cage sizing according to embodiments of the present disclosure are shown. In particular, FIG. 4A shows a front view of the distal end of a cage template according to the present disclosure, FIG. 4B shows a perspective view of a cage template according to the present disclosure, FIG. 4C shows a side view of a cage template according to the present disclosure, and FIG. 4D shows top and bottom views of a cage template according to the present disclosure. As shown in FIGS. 4A-4D, the cage template can include an upper cage template 410, a lower cage template 412, control supports 420, 422, and an extension housing 440, which are used to prevent disassembly of the mechanical system when the cage template is placed in its initial insertion configuration (i.e., shortest and least lordotic). Similarly, the cage template includes mechanical systems 430, 432, 434, 436 configured to interface with the mechanical systems of a sizing tool to facilitate manipulation and deformation of the cage template. As a non-limiting example, the cage template mechanical system may include a drive shaft 436, a gear 432, and a support member 434. The drive shaft 430 may have a hexagonal head 430 configured to mate with a corresponding interface on the sizing tool body, such as an interface that is mechanically coupled to either of mechanical interfaces 310, 320 in FIG. 3A. The drive shaft is threaded such that rotation of the sizing tool body mechanical interface (e.g., mechanical interface 310 or 320) rotates the drive shaft 436. Rotation of the drive shaft 436 rotates the gear 432, which interacts with the control supports 420, 422 to effect movement and manipulation of the cage template configurations described above.

[0034] To further illustrate exemplary mechanical systems and mechanisms for manipulating and transforming the cage template configuration, FIG. 5 shows an image of a cage template according to an embodiment of the present disclosure. As shown in FIG. 5, the cage template includes an upper cage template 510 and a lower cage template 512, and control supports 514 and 516. The control supports 514 and 516 are provided with guide slots 504 and 506 and a central slot 508, and a pin 502 can be disposed within each slot 504, 506, and 508. As described above, when the drive shaft 436 is rotated in a first direction indicated by arrow 520, the upper cage template 510 and the lower cage template 512 can move. During such movement, the pin 502 within the slots 504 and 506 can control the generation of the angle θ, as described above with reference to FIGS. 3E-3F. Similarly, the pin 502 within the slot 508 can control the movement of the upper and lower cage templates, as described above with reference to FIGS. 3D and 3F. Additionally, reversing the rotational direction of drive shaft 436 to direction 522 can reverse the movement of the upper and lower cage templates. In one embodiment, when drive shaft 436 rotates in a first direction, support members 434 advance in direction 520, and when rotated in the opposite direction, they retreat in direction 522. Advancement of support members 434 effects movement and manipulation of upper and lower cage plates 510, 512, while guide slots 504, 506, 508 can limit the range of movement and manipulation. In one embodiment, multiple drive shafts and support members 434 can be provided to perform different types of movement and manipulation on upper and lower cage plates 510, 512, as described above. For example, the first drive shaft and support member 434 may be configured to control the movement of the upper cage plate 510 and the lower cage plate 512 as described with reference to FIG. 3D, and the second drive shaft and support member 434 may be configured to control the formation of the angle θ relative to the upper cage plate 510 and the lower cage plate 512 as described above with reference to FIG. 3E.

[0035] While exemplary details regarding cages and cage templates have been described, it should be understood that these exemplary cages and cage templates are provided for purposes of illustrating the concepts disclosed herein, and that the sizing tools and techniques described herein can be utilized with any of a variety of cages and other medical devices used in spinal surgery. For example, FIGS. 6A-6I are block diagrams illustrating additional cage embodiments to which the sizing and configuration techniques described above can be applied. FIG. 6A illustrates a cage 610 including a central opening 612 and sensors 614 positioned on either side of the opening. Similarly, FIG. 6B is a block diagram of a cage 620 having two openings 622 positioned at the longitudinal edges of the cage 620 and one sensor 624 positioned between the two openings 622, and FIG. 6C is a block diagram of a cage 630 having a central opening 632 and four sensors 634 positioned at the corners of the cage 630. As is apparent from FIGS. 6A and 6B, it should be understood that cage templates according to the present disclosure are not limited to the four sensors described in FIG. 3B, but can utilize one or more sensors to determine optimal cage configurations.

[0036] 6D-6F, block diagrams illustrating lateral profiles achievable using the sizing and construction techniques described herein are shown. In particular, FIG. 6D illustrates a cage profile 640 in which the upper and lower cage templates are maintained substantially parallel to one another, FIG. 6E illustrates a cage profile 650 in which the upper and lower cage templates are manipulated to form an angle (θ), and FIG. 6F illustrates a cage profile 660 in which only the upper cage template is manipulated to form an angle (θ). As can be seen from FIGS. 6D-6F, the above-described manipulations and modifications, including the simultaneous use of multiple modifications as described above with reference to FIG. 3F, enable the creation of a variety of cage profiles, providing a robust capability for determining the appropriate cage size for a particular spinal procedure, patient anatomy, and connection characteristics.

[0037] Referring to Figures 6D and 6H, block diagrams illustrating further embodiments of cage templates according to embodiments of the present disclosure are shown. In particular, Figures 6G and 6H illustrate a cage template 670 having a central opening 672. The cage 670 is also shown to have a length 674, a height 676, and a width 678. As noted above, the height 676 of the cage template 670 can be varied, such as by increasing or decreasing the height 676, using the movements described with reference to Figure 3D. Similarly, the height 676 of the cage template 670 can also be adjusted to provide a non-uniform height by forming an angle (θ) as described with reference to Figure 6E. Furthermore, the height 676 can also be adjusted to provide a non-uniform height by combining the movements described with reference to Figures 3D and 3F with the movements described with reference to Figures 3E and 3F, such that the height of the cage template 670 is increased or decreased.

[0038] FIG. 6I shows a block diagram of a cage having teeth on at least the upper or lower surface. In particular, FIG. 6I shows a cage 680 having teeth 682 on its upper surface. The teeth 682 may be provided to hold the cage 680 in place or to promote bone growth in the spinal segment into which the cage 680 is inserted. In one embodiment, the cage template may be designed to approximate the full height of the cage 680, taking into account the presence of the teeth 682, such that the height of the cage template is equal to or approximately equal to the height of the cage 680. However, in this case, the cage template may be toothless to facilitate insertion and removal of the sizing tool and the cage template.

[0039] 7, a flow diagram of an exemplary method for determining the appropriate size of a medical implant for use in a spinal procedure involving two vertebral segments is shown as method 700. As described above, the medical implant sized using method 700 may be a cage for a spinal fusion procedure. Method 700 may be performed using the exemplary cage template described with reference to FIGS. 1-6I to determine the appropriate size of the medical implant.

[0040] At step 710, method 700 includes, with the cage template positioned between two vertebral segments, modifying the configuration of the cage template positioned at the distal end of the sizing tool with a sizing tool. In one embodiment, the cage template can be modified as described with reference to FIGS. 3C-3F. As described above, the modification can be configured to change the curvature angle, height, or both of the cage template. In one embodiment, the modification of the cage template configuration can be performed using one or more mechanical interfaces of the sizing tool, such as mechanical interfaces 310, 320 of FIG. 3A.

[0041] At step 720, method 700 includes measuring forces applied to the cage template from at least one of the two vertebral segments using a plurality of sensors in the cage template during the reconfiguration of the cage template. In one embodiment, the sensors can be embedded or positioned in the top and bottom of the cage template, such as the recesses shown in FIG. 4B. At step 730, method 700 includes outputting, by one or more processors, information related to the forces applied to the cage template during the reconfiguration. As described above, the sensors in the cage template can be in wired or wireless communication with one or more remote devices, such as computing device 140 of FIG. 1, to provide sensor data and measurements to the remote devices for display. For example, the computing device can be configured to receive measurements from the sensors in the cage template and present the sensor information on a display device (e.g., a monitor). The sensor measurements can be displayed as raw data (e.g., force or pressure measurements). Additionally or alternatively, information derived from the sensor measurements can be generated and displayed by the computing device. For example, a graphical user interface can display one or more color-coded indicators to indicate the pressure or force applied to the cage template during the reconfiguration. By way of non-limiting example, red may indicate excessive pressure or force, yellow may indicate caution (e.g., risk of hyperextension), and green may indicate adequate pressure or force. Other types of information may also be displayed to provide real-time feedback regarding the pressure being applied during cage template configuration adjustment. For example, an image of a cage template may be displayed, and color-coded indicators or other information may be displayed on the image to indicate the pressure or force being applied to each region of the upper or lower cage template (e.g., adequate pressure, excessive pressure, or insufficient pressure in each portion of the upper or lower cage template).

[0042] In step 740, method 700 includes determining a cage to be used in the spinal surgery involving two vertebral segments based on the final configuration of the cage template. As described above, based on the sensor data measurements and the manipulation of the cage template, the surgeon can determine an optimal cage configuration. An optimal cage configuration is one that has an appropriate lordosis angle and / or height and applies an appropriate force to the cage template. As an example, an optimal cage configuration may apply a relatively high force to all or part of the periphery of the cage template (where stronger or harder bone may be located) and some force near the implantation window (e.g., the opening of the cage or cage template). Applying a higher force where hard bone masses are present and a lower force where soft bone masses are present can reduce or eliminate the risk of subsidence and improve the clinical outcome of the spinal surgery. As described above, the final configuration of the cage template can be determined, at least in part, based on the configuration modification and information about the force applied to the cage template during the modification. In one embodiment, the remote computing device can be configured to display the final configuration of the cage template and / or the optimal cage to be used in the spinal surgery. For example, the computing device may use the sensor measurement data and information related to the cage template in use to identify the optimal cage (eg, using a look-up table or other techniques).

[0043] In one embodiment, method 700 may include selecting a different cage template if it is determined that an optimal configuration cannot be achieved using the cage template. In this case, the reconfiguration, measurement, output, and determination steps 710-740 may be repeated using a different cage template. For example, the initial cage template may have a first height range, and a different cage template may have a second height range that is larger or smaller than the first height range. The first height range corresponds to a range of cage template heights that can be achieved by reconfiguring the initial cage template, and the second height range corresponds to a range of heights that can be achieved by reconfiguring the different cage template. If the initial cage template does not provide sufficient pressure or force, method 700 may use a different cage template with a wider height range to evaluate whether increased height provides adequate force or pressure. A similar approach can be applied if the lordotic angle needs to be changed. For example, the initial cage template has a first lordotic angle range, and the different cage template has a second lordotic angle range that is greater than or less than the first lordotic angle range, where the first lordotic angle range corresponds to a range of lordotic angles that can be achieved by reconfiguring the initial cage template, and the second lordotic angle range corresponds to a range of lordotic angles that can be achieved by reconfiguring the different cage template. Note that a cage template with the same height but a different lordotic angle can be used, such as when the height is correct but the angle is not correct in the initial cage template.

[0044] Clause 1: A cage template mechanically coupleable to a distal end of a body, the cage template including: an upper cage template; a lower cage template; a first sensor corresponding to the upper cage template; a second sensor corresponding to the lower cage template; and a first control support and a second control support coupled to the upper cage template and the lower cage template, respectively, wherein the upper cage template and the lower cage template are movable relative to each other to change a configuration of the cage template. In one embodiment, the upper cage template and the lower cage template are movable relative to each other to change a configuration of the cage template, as described with reference to Figures 1-6I above.

[0045] Clause 2: A system comprising: a cage template mechanically coupleable to a distal end of a body, the cage template including: an upper cage template; a lower cage template; a first sensor corresponding to the upper cage template; a second sensor corresponding to the lower cage template; and first and second control supports coupled to the upper and lower cage templates, respectively; and a sizing tool comprising: an elongated body having a proximal end and a distal end; means for transmitting mechanical forces to the first and second control supports to change a configuration of the cage template when the cage template is positioned between two vertebral segments, the first sensor configured to measure a first force applied to the upper cage template by at least one of the two vertebral segments during the change in configuration of the cage template, and the second sensor configured to measure a second force applied to the lower cage template by at least one of the two vertebral segments during the change in configuration of the cage template; and means for outputting the first force and the second force.

[0046] Clause 3: The system described in clause 1, wherein the cage template has an opening corresponding to the implantation window.

[0047] Clause 4: The system described in Clause 1, wherein the cage template has a third sensor corresponding to the upper cage template, and the first sensor and the third sensor are positioned at opposite positions across an opening in the cage template.

[0048] Clause 5: The system described in Clause 3, wherein the cage template has a fourth sensor corresponding to the lower cage template, and the second sensor and the fourth sensor are positioned on opposite sides of an opening in the cage template.

[0049] Clause 6: The system described in Clause 1, further comprising a plurality of additional sensors, the plurality of additional sensors including a first sensor set corresponding to the upper cage template and a second sensor set corresponding to the lower cage template, the first sensor set being positioned on the periphery of the upper cage template and the second sensor set being positioned on the periphery of the lower cage template.

[0050] Clause 7: The system described in Clause 5, wherein the plurality of additional sensors includes a third sensor set corresponding to the upper cage template and a fourth sensor set corresponding to the lower cage template, the third sensor set being arranged around a central opening of the cage template, and the fourth sensor set being arranged around a central opening of the cage template.

[0051] Clause 8. The system of clause 1, wherein altering the configuration of the cage template includes vertically moving the upper cage template relative to the lower cage template.

[0052] Clause 9: The system of clause 1, wherein changing the configuration of the cage template includes rotating the upper cage template vertically relative to the lower cage template.

[0053] Clause 10: The system described in Clause 1, wherein changing the configuration of the cage template includes vertically moving the upper cage template relative to the lower cage template and rotating the upper cage template relative to the lower cage template.

[0054] Clause 11: The system described in Clause 1, further comprising means for tracking the configuration of a cage template, wherein the final configuration of the cage template is configured to approximate a cage sized for use in a spinal surgery involving the two vertebral segments.

[0055] Clause 12: A method for determining a sized cage for use in a spinal surgery involving two vertebral segments, the method comprising the steps of: altering, with a sizing tool, a configuration of a cage template disposed at a distal end of the sizing tool while the cage template is positioned between the two vertebral segments, the alteration being configured to change a lordosis angle of the cage template, a height of the cage template, or both; and measuring, with a plurality of sensors on the cage template, forces exerted on the cage template by at least one of the two vertebral segments during the alteration of the cage template configuration; outputting, by one or more processors, information related to forces applied to the cage template during the configuration change; and determining a cage to be used in a spinal surgery involving the two vertebral segments based on a final configuration of the cage template, wherein the final configuration of the cage template is based at least in part on the changes and the information related to forces applied to the cage template during the changes.

[0056] Clause 13: The method described in Clause 12, wherein the cage template includes an upper cage template and a lower cage template, and the plurality of sensors includes at least one sensor associated with the upper cage template and at least one sensor associated with the lower cage template.

[0057] Clause 14: The method of clause 13, wherein the lordosis angle of the cage template is changed by rotating the upper cage template and the lower cage template relative to each other.

[0058] Clause 15: The method of clause 13, wherein the height of the cage template is changed by vertically moving the upper cage template and the lower cage template.

[0059] Clause 16: The method described in Clause 12, comprising selecting another cage template in response to determining that the optimal configuration of the cage template cannot be achieved using the cage template, and the modifying, measuring, outputting and determining steps are repeated using the other cage template.

[0060] Clause 17: The method described in Clause 16, wherein the cage template has a first height range and the other cage template has a second height range greater than or less than the first height range, the first height range corresponding to the height range of the cage template that can be realized by the cage template through the modification, and the second height range corresponding to the height range of the cage template that can be realized by the other cage template through the modification.

[0061] Clause 18: The method described in Clause 16, wherein the cage template has a first lordosis angle range, and the other cage template has a second lordosis angle range that is greater than or less than the first lordosis angle range, the first lordosis angle range corresponding to the range of lordosis angles that can be achieved by the cage template through the modification, and the second lordosis angle range corresponding to the range of lordosis angles that can be achieved by the other cage template through the modification.

[0062] Clause 19: A spinal surgery kit, the kit comprising: an upper cage template; a lower cage template; a first sensor corresponding to the upper cage template; a second sensor corresponding to the lower cage template; and a first control support and a second control support coupled to the upper cage template and the lower cage template, respectively, wherein the configuration of the cage template is adjustable to change the height of the cage template, the lordosis angle of the cage template, or both.

[0063] Clause 20: The kit described in Clause 19, wherein the kit further comprises a sizing tool, the sizing tool including an elongated body having a proximal end and a distal end; and means for transmitting mechanical force to the first control support and the second control support to change the height of the cage template, the lordosis angle of the cage template, or both, when the cage template is positioned between two vertebrae.

[0064] Clause 21: A method as described in either clause 19 or 20, wherein the first sensor is configured to measure a first force applied to the upper cage template by at least one of two vertebral segments during configuration change of the cage template, and the second sensor is configured to measure a second force applied to the lower cage template by at least one of two vertebral segments during configuration change of the cage template.

[0065] Clause 22: The method of any of clauses 19 to 21, wherein the method further comprises a plurality of cages having different heights, different lordotic angles, or both.

[0066] Clause 23: The method of any of clauses 19 to 22, further comprising one or more additional cage templates.

[0067] It should be understood that the present systems, kits, devices and methods are not limited to the particular forms disclosed, but rather the invention is intended to cover all combinations, modifications, equivalents and alternatives falling within the scope of the claims.

[0068] No claim should be construed as including means-plus-function or step-plus-function limitations unless the claim is expressly limited using the phrase "means for" or "step for."

[0069] The term "coupled" is defined to mean connected, although not necessarily directly, and not necessarily mechanically connected.

[0070] In the claims and / or specification, the words "a" or "an" used in conjunction with "comprising" can mean "one," but are also consistent with "one or more" or "at least one." The word "about" generally means ±5% of the stated value. The word "or" in the claims is used to mean "and / or" unless explicitly referring to alternatives only or where the alternatives are mutually exclusive. Note that this disclosure supports definitions that refer only to alternatives and "and / or."

[0071] The terms "comprise" (and all forms of "comprise," such as "comprises" and "comprising"), "have" (and all forms of "have," such as "has" and "having"), "include" (and all forms of "include," such as "includes" and "including"), and "contain" (and all forms of "contain," such as "contains" and "containing") are open-ended linking verbs. Consequently, a method or apparatus that "has," "includes," or "contains" one or more steps or elements has those one or more steps or elements, but is not limited to having only those one or more elements. Similarly, a method step or apparatus element that "has," "includes," or "contains" one or more features has those one or more features, but is not limited to having only those one or more features. Furthermore, a device or structure that is configured in a particular way is configured in at least that way, but may also be configured in ways not listed.

[0072] In the foregoing Detailed Description, for the purpose of brevity, various features are grouped together in multiple embodiments. This method of disclosure is not to be interpreted as reflecting an intention that the disclosed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may lie in fewer than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as an independent embodiment.

[0073] Although the embodiments and advantages of the present disclosure have been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the spirit and scope of the present disclosure, as defined by the appended claims. Moreover, the scope of the present disclosure is not intended to be limited to the particular embodiments of the processes, machines, manufacture, compositions of matter, means, methods, and steps described herein. As will be readily apparent from this disclosure to those skilled in the art, any currently existing or later-developed processes, machines, manufactures, compositions of matter, means, methods, or steps that perform substantially the same function or achieve substantially the same results as the corresponding embodiments described herein can be utilized in accordance with the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufactures, compositions of matter, means, methods, or steps.

Claims

1. 1. A system, comprising: a cage template mechanically coupleable to a distal end of a body, said cage template comprising: Upper cage template; Lower cage template; a first sensor corresponding to the upper cage template; a second sensor corresponding to the lower cage template; and a first control support and a second control support coupled to the upper cage template and the lower cage template, respectively; a cage template including: A sizing tool, comprising: an elongate body having a proximal end and a distal end; a means for transmitting a mechanical force to the first control support and the second control support to change a configuration of the cage template when the cage template is positioned between two vertebral segments, the first sensor being configured to measure a first force applied to the upper cage template by at least one of the two vertebral segments during the change in configuration of the cage template, and the second sensor being configured to measure a second force applied to the lower cage template by at least one of the two vertebral segments during the change in configuration of the cage template; and means for outputting the first force and the second force; a sizing tool, A system comprising:

2. The system of claim 1 , wherein the cage template has an opening corresponding to an implantation window.

3. 2. The system of claim 1, wherein the cage template has a third sensor corresponding to the upper cage template, and the first sensor and the third sensor are positioned on opposite sides of an opening in the cage template.

4. 4. The system of claim 3, wherein the cage template has a fourth sensor corresponding to the lower cage template, and the second sensor and the fourth sensor are positioned on opposite sides of an opening in the cage template.

5. 10. The system of claim 1, the system further comprising a plurality of additional sensors; the plurality of additional sensors includes a first set of sensors corresponding to the upper cage template and a second set of sensors corresponding to the lower cage template; the first set of sensors is positioned on a periphery of the upper cage template; the second set of sensors is disposed on a periphery of the lower cage template.

6. the plurality of additional sensors includes a third set of sensors corresponding to the upper cage template and a fourth set of sensors corresponding to the lower cage template; the third set of sensors is positioned around a central opening of the cage template; The system of claim 5 , wherein the fourth set of sensors is positioned around a central opening of the cage template.

7. The system of claim 1 , wherein changing the configuration of the cage template comprises vertically moving the upper cage template relative to the lower cage template.

8. The system of claim 1 , wherein changing the configuration of the cage template includes vertically rotating the upper cage template relative to the lower cage template.

9. 2. The system of claim 1, wherein changing the configuration of the cage template includes vertically moving the upper cage template relative to the lower cage template and rotating the upper cage template relative to the lower cage template.

10. further comprising means for tracking the configuration of the cage template; 10. The system of claim 1, wherein the final configuration of the cage template is configured to approximate a cage sized for use in a spinal surgery involving the two vertebral segments.

11. 1. A method for determining a cage sized for use in a spinal procedure involving two vertebral segments, the method comprising: modifying a configuration of the cage template located at a distal end of the sizing tool while the cage template is positioned between the two vertebral segments with a sizing tool, the modification is configured to change the lordotic angle of the cage template, the height of the cage template, or both; measuring, with a plurality of sensors in the cage template, forces exerted on the cage template by at least one of the two vertebral segments during reconfiguration of the cage template; outputting, by one or more processors, information related to forces applied to the cage template during the modification; and determining a cage to be used in a spinal surgery for the two vertebral segments based on the final configuration of the cage template; a final configuration of the cage template based at least in part on the modification and information related to forces applied to the cage template during the modification; A method comprising:

12. the cage template includes an upper cage template and a lower cage template; The method of claim 11 , wherein the plurality of sensors includes at least one sensor associated with the upper cage template and at least one sensor associated with the lower cage template.

13. The method of claim 12 , wherein the lordosis angle of the cage template is changed by rotating the upper and lower cage templates relative to each other.

14. The method of claim 12 , wherein the height of the cage template is changed by vertically moving the upper cage template and the lower cage template.

15. selecting another cage template in response to determining that an optimal configuration of the cage template cannot be achieved using the cage template; The method of claim 11 , wherein the modifying, measuring, outputting, and determining steps are repeated with the other cage template.

16. the cage template has a first height range; the other cage template has a second height range that is greater than or less than the first height range; the first height range corresponds to a height range of the cage template that can be achieved by the cage template through the modification; The method of claim 15 , wherein the second height range corresponds to a height range of a cage template that can be achieved by the other cage template through the modification.

17. the cage template has a first lordotic angle range; the other cage template has a second lordotic angle range that is greater than or less than the first lordotic angle range; the first lordotic angle range corresponds to a range of lordotic angles achievable by the cage template through the modification; The method of claim 15 , wherein the second lordotic angle range corresponds to a range of lordotic angles achievable by the other cage template through the modification.

18. 1. A spinal surgery kit, comprising:

1. A cage template comprising: Upper cage template; Lower cage template; a first sensor corresponding to the upper cage template; a second sensor corresponding to the lower cage template; and a first control support and a second control support coupled to the upper cage template and the lower cage template, respectively; a cage template, wherein the configuration of the cage template is adjustable to change the height of the cage template, the lordotic angle of the cage template, or both.

19. 19. The kit of claim 18, comprising:

1. A sizing tool comprising: an elongate body having a proximal end and a distal end; and means for transmitting a mechanical force to the first control support and the second control support to change the height of the cage template, the lordosis angle of the cage template, or both when the cage template is positioned between two vertebrae; Sizing tools, including The kit further comprises:

20. the first sensor is configured to measure a first force applied to the upper cage template by at least one of two vertebral segments during a reconfiguration of the cage template; 20. The kit of claim 19, wherein the second sensor is configured to measure a second force applied to the lower cage template by at least one of two vertebral segments during reconfiguration of the cage template.

21. 20. The kit of claim 19, further comprising a plurality of cages having different heights, different lordotic angles, or both.

22. 20. The kit of claim 19, further comprising one or more additional cage templates.

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