Femur Broach Base Measuring Tool

Abstract

A system and method for determining the position of a broach tool used in total hip arthroplasty are disclosed herein, where the broach is still positioned within the femoral canal of the patient's femur, and the position is determined after the broach. Also disclosed herein is an example of a broach tool adapter used to attach a tracking array to the broach tool, the adapter having a body shape that mates with the geometric shape of a particular brand of broach tool and having a common slot defined therein for receiving a tracking array such as attaching the tracking array to the broach tool.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 344,086, filed May 20, 2022, with the title "Femoral Broach - Based Measurement Tool", the content of which is hereby incorporated by reference in its entirety.

[0002] This disclosure generally relates to orthopedic procedures, such as total joint replacement surgery, and more particularly to total hip replacement surgery.

Background Art

[0003] Orthopedic procedures for replacing joints, such as knees and hips, are well - known and common in today's society. Such procedures may require the removal or reshaping of a portion of bone to receive an orthopedic implant to replace the original joint. For example, during total hip replacement surgery, the surgeon must broach the patient's femoral canal to receive an implant having a stem portion that is inserted into the femoral canal and a ball portion of a ball - and - socket joint that mates with a socket portion that is implanted into the hip bone.

[0004] Such procedures may be performed with the assistance of a navigation or robotic - assisted surgery platform that can track the position of the patient's femur relative to the operating room or the patient's anatomical structure and provide guidance to the surgeon during the procedure.

[0005] Total joint replacement often includes the ability to predict the range of motion (ROM) of the entire implant construct using femur rotation measurements based on broach and stem data. These capabilities require a robust and accurate connection to the femur component so that the tracking array can be accurately and repeatedly positioned during the surgical workflow. The bylaws of the incision size and exposure to the available anatomical structure present challenges to the solutions placed in the normal operative field, especially for the supine approach.

[0006] Prior art methods supported stem position measurement using tools connected to a stem taper that holds a tracking array. These tools did not measure the orientation of the femoral component and were free to rotate about the taper axis of the femoral stem. This connection style is not suitable for the range of motion function because the orientation of the tracking array must be kept constant relative to the orientation of the femoral component. The orientation of the femoral component was assumed instead of a reliable measurement process.

[0007] Other prior art methods utilize a physical connection to the femur for measuring femoral rotation using multiple pins driven into the proximal and distal femur. These pin insertions can interrupt the workflow and may require additional incisions not present in conventional total hip arthroplasty. The tracking array holder is connected to these pins via a holding clamp device. Additionally, a tracker attached to the broach insertion tool is used for tracking the femoral broach.

[0008] In yet another prior art method, an enhanced femoral workflow uses a custom trial neck with a landmark registration dowel so that a pointer probe can register the orientation and position of a specified femoral component. In addition to the checkpoint screw, this trial neck is used to complete the femoral workflow steps. This prior art method requires preoperative CT and does not support a direct anterior approach for femoral workflow improvement for all stem families. SUMMARY OF THE INVENTION

[0009] The devices and processes described herein provide a combination of tracking array holders that enable a repeatable fixed connection to a device placed within the proximal femur, e.g., within a femoral canal broaching tool. The combination of these instruments consists of a tool attached to the connecting shape of the femoral broach and a tracking array holder attached to the front or side of the proximal femur via a magnetic connection to a screwed plate.

[0010] The disclosed embodiments have two features. The first feature is directed to the broach array, and the femur array can be used in combination to obtain live measurements of femur rotation based on the positioning of the stem taper of the broach tool. The broach array can be attached to the broach tool after completion of the broaching process to measure or otherwise determine the position of the broach tool relative to the anatomical structure of the femur registered by the femur array attached to the femur. Thus, by using the femur array and the broach array together, an improved method of determining the final femur rotation is provided by determining the relative positions of the two arrays.

[0011] The second feature of the embodiments of the present disclosure is directed to providing several different embodiments of broach adapters used to attach the broach array to the broach tool. This enables the use of broach arrays with various broach tools from different manufacturers having different shapes.

[0012] In a first embodiment, a method for measuring the position of a broach tool in a total hip arthroplasty procedure includes attaching a first tracking array to the patient's femur, registering the position of the femur using the tracking array, attaching a second tracking array to the broach tool after broaching the femoral canal, and determining the position of the broach tool relative to the femur based on a comparison of the positions of the first and second tracking arrays.

[0013] In the first embodiment or any other embodiment disclosed herein, the method further includes attaching the first tracking array to the femur via a bonding plate that magnetically engages an attachment plate on a holder for the first tracking array.

[0014] In the first embodiment or any other embodiment disclosed herein, the method further includes enabling the attachment plate to allow for multiple orientations of the first tracking array.

[0015] In the first embodiment or any other embodiment disclosed herein, the method further includes attaching the attachment plate to the proximal femur targeting the greater trochanter.

[0016] In the first embodiment or any other embodiment disclosed herein, the method further includes registering the position of the femur by tracking the first tracking array using a tracking system having one or more sensors for collecting real-time position data, and further includes the software executed on the surgical computer calculating and registering the position of the femur based on the position data.

[0017] In the first embodiment, or any other embodiment disclosed herein, the method further includes attaching a second tracking array to the broach tool by providing a broach adapter attached to the broach tool and attaching the second tracking array to the broach adapter.

[0018] In the first embodiment, or any other embodiment disclosed herein, the method further includes adapting the broach adapter to conform to the geometric shape of the broach tool.

[0019] In the first embodiment or any other embodiment disclosed herein, the method further includes attaching the broach adapter to the broach tool using a spring mechanism.

[0020] In the first embodiment or any other embodiment disclosed herein, the method further includes that the broach adapter includes a slot adapted to receive the proximal end of the tracking array holder.

[0021] In the first embodiment or any other embodiment disclosed herein, the method further includes that the proximal end of the tracking array holder has a spring component thereon with a protrusion that engages a recess defined within the slot of the broach adapter.

[0022] In the first embodiment or any other embodiment disclosed herein, the method further includes that comparing the positions of the first and second tracking arrays involves using a tracking system having one or more sensors to collect real-time position data of the first and second tracking arrays, and calculating the position of the broach tool relative to the registered position of the femur based on the position data.

[0023] In the first embodiment or any other embodiment disclosed herein, the method further includes that calculating the position of the broach tool is performed by software executed on a surgical computer.

[0024] In a second embodiment, an apparatus for adapting a holder for a tracking array to a broach tool includes a body shaped to conform to the geometry of the broach tool, a lever biased by a spring to engage features of the geometry of the broach tool, and a slot defined within the body of the apparatus for receiving the holder for the tracking array.

[0025] In the second embodiment or any other embodiment disclosed herein, the apparatus further includes that the broach tool is disengaged from the body by pivoting the lever to disengage the lever from the features of the geometry of the engaged broach tool.

[0026] In the second embodiment or any other embodiment disclosed herein, the apparatus further includes a holder for the tracking array, and the slot defined within the body is adapted to receive the proximal end of the holder for the tracking array, the proximal end including an arm having a protrusion defined thereon that engages a recess defined within the slot.

[0027] In the second embodiment, or any other embodiment disclosed herein, the apparatus further includes that the distal end of the holder for the tracking array includes a plurality of arms, and at least some of the arms define shoulders to prevent rotation or tilting of the holder relative to the body.

[0028] In the second embodiment, or any other embodiment disclosed herein, the apparatus further includes that the holder of the tracking array is disengaged from the body by bending the arm such that the protrusion is disengaged from the recess defined within the slot.

[0029] In a third embodiment, the system includes a tracking system having one or more sensors, a processor, and software that, when executed by the processor, causes the system to determine the position of the femur by tracking a first tracking array mechanically connected to the femur using the tracking system, collect real-time position data of the first tracking array, determine the position of the broach tool disposed within the femoral canal of the femur by tracking a second tracking array mechanically connected to the broach tool using the tracking system, collect real-time position data of the second tracking array, and calculate the position of the broach tool relative to the femur based on a comparison of the position data representing the positions of the first and second tracking arrays.

[0030] Embodiments of the present disclosure provide a number of advantages. For example, by enabling multiple engagements and disengagements of the tracking array during treatment without the need to re-register the array. Further, various embodiments of the broach adapter are provided for broach tools having different shapes, and all broach adapters have a common interface for receiving a holder of the broach tracking array, such that the broach tracking array can be used with broach tools from different manufacturers.

[0031] At least some further features and advantages of embodiments of the present disclosure, as well as the structure and operation of various examples of embodiments of the present disclosure, are described in detail below with reference to the accompanying drawings.

[0032] By way of example, specific embodiments of the disclosed systems and methods are described herein with reference to the following accompanying drawings.

Brief Description of the Drawings

[0033]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4A

Figure 4B

Figure 4C

Figure 5A

Figure 5B

Figure 5C

Figure 6A

Figure 6B

Figure 6C

Figure 7A

Figure 7B

[0034] Definitions For the purposes of the present disclosure, the term " Implant " is used to refer to an artificial device or structure manufactured to replace or enhance a biological structure. For example, an artificial acetabular cup (implant) is used to replace or enhance a patient's worn or damaged acetabulum in total hip arthroplasty. The term "implant" is generally considered to indicate an artificial structure (as opposed to a transplant), but for the purposes of this specification, an implant may include biological tissue or material implanted to replace or enhance a biological structure.

[0035] Much of the present disclosure refers to surgeons or other medical professionals in specific positions or roles, but nothing in the present disclosure is intended to be limited to specific positions or functions. Surgeons or medical professionals can include any physician, nurse, medical professional, or technician. Any of these terms or positions can be used interchangeably with the users of the systems disclosed herein unless otherwise explicitly mentioned. For example, a reference to a surgeon may, in some embodiments, also apply to a technician or a nurse.

[0036] Detailed Description The systems and methods disclosed herein provide information to a surgeon during the preoperative and intraoperative stages of an arthroplasty procedure to assist the surgeon in planning and performing the surgery to minimize both intraoperative and postoperative negative outcomes for the patient. It should be noted that the disclosed embodiments are described with respect to total hip arthroplasty, but all or some of the disclosed embodiments may be applicable to any arthroplasty procedure.

[0037] The present disclosure is not limited to the specific systems, devices, and methods described. This is because they can vary. The terms used in the description are used for the purpose of describing only specific variations or embodiments and are not intended to limit the scope.

[0038] As used herein, the singular forms "a", "an", and "the" include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. As used herein, the term "comprising" means "including, but not limited to".

[0039] Overview of CASS FIG. 1 provides a diagram of an exemplary computer-assisted surgical system (CASS) 100 according to some embodiments. As will be described in more detail in the following sections, the CASS uses computer, robotics, and imaging technologies to assist a surgeon in performing orthopedic surgeries such as total knee arthroplasty (TKA) or total hip arthroplasty (THA). For example, a surgical navigation system can assist a surgeon in finding a patient's anatomical structure, guiding surgical instruments, and implanting medical devices with a high degree of accuracy. Surgical navigation systems such as the CASS 100 often employ various forms of computing technology to perform a wide range of standard and minimally invasive surgical procedures and techniques. Additionally, these systems enable a surgeon to more accurately plan, track, and navigate the placement of instruments and implants relative to a patient's body, as well as perform pre-operative and intra-operative body imaging.

[0040] The effector platform 105 positions surgical tools with respect to a patient during surgery. The exact components of the effector platform 105 will vary depending on the embodiment employed. For example, for knee surgery, the effector platform 105 may include an end effector 105B that holds a surgical tool or instrument during use. The end effector 105B can be a handheld device or instrument used by a surgeon (e.g., the handpiece or cutting guide or jig of NAVIO®), or alternatively, the end effector 105B can include a device or instrument held or positioned by the robotic arm 105A.

[0041] The effector platform 105 may include a limb positioning device 105C for positioning a patient's limb during surgery. An example of the limb positioning device 105C is the SMITH AND NEPHEW SPIDER2 system. The limb positioning device 105C may be manually operated by a surgeon or, alternatively, may change the limb position based on instructions received from a surgical computer 150 (described below).

[0042] The effector platform 105 may also include a cutting guide or jig 105D used to guide a saw or drill used to excise tissue during surgery. Such a cutting guide 105D can be integrally formed as part of the effector platform 105 or the robotic arm 105A, or the cutting guide can be a separate structure that can be fitted and / or removably attached to the effector platform 105 or the robotic arm 105A. The effector platform 105 or the robotic arm 105A can be controlled by the CASS 100 to position the cutting guide or jig 105D adjacent to a patient's anatomical structure according to a surgical plan developed pre - or intra - operatively, such that the cutting guide or jig will produce an accurate bone cut according to the surgical plan.

[0043] Tracking system 115 uses one or more sensors to collect real-time position data that identifies a patient's anatomical structure and surgical instruments. For example, for a TKA procedure, the tracking system may provide the location and orientation of the end effector 105B during the procedure. In addition to the position data, data from the tracking system 115 can be further used to infer the speed / acceleration of anatomical structures / measurements that can be used for tool control. In some embodiments, the tracking system 115 may use a tracker array attached to the end effector 105B to determine the location and orientation of the end effector 105B. The position of the end effector 105B can be inferred based on the position and orientation of the tracking system 115 and the known relationship in three-dimensional space between the tracking system 115 and the end effector 105B. In various examples of embodiments of the present disclosure, various types of tracking systems may be used, including, but not limited to, infrared (IR) tracking systems, electromagnetic (EM) tracking systems, video or image-based tracking systems, and ultrasonic registration and tracking systems.

[0044] Any suitable tracking system can be used to track the surgical target and the patient's anatomical structure within the surgical space. For example, a combination of an IR camera and a visible light camera can be used in an array. Various illumination sources, such as an IR LED light source, can illuminate the scene to enable three-dimensional imaging. In some embodiments, this may include imaging such as stereoscopic, triscopic, and four-sided viewing. In some embodiments, in addition to a camera array fixed to a cart, additional cameras can be placed throughout the surgical space. For example, a handheld tool or a headset worn by an operator / surgeon can include imaging capabilities that communicate images to a central processor and correlate those images with the images captured by the camera array. This can result in a more robust image of the environment for modeling using multiple viewpoints. Additionally, some imaging devices can have a suitable resolution or have a suitable viewpoint with respect to the scene to capture information stored in a quick response (QR) code or barcode. This can help identify specific objects not manually registered in the system.

[0045] In some embodiments, specific objects can be manually registered in the system preoperatively or intraoperatively by the surgeon. For example, by interacting with a user interface, the surgeon can identify the starting location of a tool or a bone structure. By tracking fiducial marks associated with that tool or bone structure or by using other conventional image tracking modalities, the processor can track the tool or bone in a three-dimensional model as it moves through the environment.

[0046] In some embodiments, certain markers, such as fiducial markers, that identify individuals, important tools, or bones within a space may include passive or active identifiers that can be picked up by a camera or camera array associated with the tracking system. For example, an IR LED can blink a pattern that conveys a unique identifier to the source of that pattern, providing a dynamic identification mark. Similarly, one-dimensional or two-dimensional optical codes (such as barcodes, QR codes, etc.) can be affixed to objects within the space to provide passive identification that can occur based on image analysis. If these codes are asymmetrically arranged on an object, these codes can also be used to determine the orientation of the object by comparing the location of the identifier to the extent of the object in the image. For example, a QR code may be placed at the corner of a tool tray, and the orientation and identifiability of that tray can be tracked. Other tracking modalities are described throughout. For example, in some embodiments, an augmented reality headset can be worn by a surgeon and other staff to provide additional camera angles and tracking capabilities.

[0047] In addition to optical tracking, specific features of an object can be tracked by registering the physical properties of the object and associating them with a trackable object, such as a fiducial marker fixed to a tool or bone. For example, a surgeon can perform a manual registration process where the tracked tool and the tracked bone can be manipulated relative to each other. By pressing the tip of the tool against the surface of the bone, a three-dimensional surface can be mapped relative to that bone, associated with the position and orientation relative to the reference frame of the fiducial marker. By optically tracking the position and orientation (pose) of the fiducial marker associated with the bone, a model of that surface can be tracked along with the environment via extrapolation.

[0048] The registration process of registering the CASS 100 to the relevant anatomical structures of the patient can also involve the use of anatomical landmarks such as landmarks on bone or cartilage. For example, the CASS 100 may include a 3D model of the relevant bone or joint, and the surgeon can use a probe connected to the CASS to collect intraoperative data on the location of bone landmarks on the patient's actual bone. Bone landmarks can include, for example, the medial and lateral condyles, the ends of the proximal femur and distal tibia, and the center of the hip joint. The CASS 100 can compare and register the location data of the bone landmarks collected by the surgeon with the probe to the location data of the same landmarks in the 3D model. Alternatively, the CASS 100 can construct a 3D model of the bone or joint using the location data of the bone landmarks and the bone surface collected by the surgeon using the CASS probe or other means without preoperative image data. The registration process can also include determining the various axes of the joint. For example, for TKA, the surgeon can use the CASS 100 to determine the anatomical and mechanical axes of the femur and tibia. The surgeon and the CASS 100 can identify the center of the hip joint by moving the patient's leg in a helical direction (i.e., circumrotation), thereby allowing the CASS to determine where the center of the hip joint is located.

[0049] The display 125 provides a graphical user interface (GUI) that displays images and other information related to the surgery. For example, the display 125 overlays image information collected from various modalities (e.g., CT, MRI, X-ray, fluorescence, ultrasound, etc.) collected preoperatively or intraoperatively to give the surgeon various views of the patient's anatomical structure and real-time condition. The display 125 can include, for example, one or more computer monitors. As an alternative or supplement to the display 125, one or more members of the surgical staff may wear an augmented reality (AR) head-mounted device (HMD). For example, in FIG. 1, the surgeon 111 is wearing an AR HMD 155 that can, for example, overlay preoperative image data on the patient or provide suggestions for the surgical plan. Various exemplary uses of the AR HMD 155 in surgical procedures are detailed in the following sections.

[0050] The surgical computer 150 provides control instructions for the various components of the CASS 100, collects data from those components, and provides general processing for the various data required during the surgery. In some embodiments, the surgical computer 150 is a general-purpose computer. In other embodiments, the surgical computer 150 can be a parallel computing platform that uses multiple central processing units (CPUs), graphics processing units (GPUs), tensor processing units (TPUs), or multiple computer instances within a cluster to perform processing. In some embodiments, the surgical computer 150 is connected to a remote server via one or more computer networks (e.g., the Internet). The remote server can be used, for example, for data storage or execution of computationally intensive processing tasks.

[0051] To connect the surgical computer 150 to other components of the CASS 100, various techniques generally known in the art can be used. Further, the computer can be connected to the surgical computer 150 using a combination of techniques. For example, the end effector 105B can be connected to the surgical computer 150 via a wired (i.e., serial) connection. The tracking system 115, the tissue navigation system 120, and the display 125 can similarly be connected to the surgical computer 150 using a wired connection. Alternatively, the tracking system 115, the tissue navigation system 120, and the display device 125 can be connected to the surgical computer 150 using wireless techniques such as, but not limited to, Wi-Fi, Bluetooth, Near Field Communication (NFC), or ZigBee.

[0052] In some embodiments, the CASS 100 can include a robotic arm 105A that functions as an interface for stabilizing and holding various instruments used during a surgical procedure. For example, in the context of a hip surgery, these instruments can include, but are not limited to, retractors, sagittal or reciprocating saws, reamer handles, cup impactors, broach handles, and stem inserters. The robotic arm 105A may have multiple degrees of freedom (such as a Spider device) and may have the ability to be locked in place (e.g., by pressing a button, voice activation, the surgeon removing their hand from the robotic arm, or other means).

[0053] In some embodiments, the movement of the robotic arm 105A can be caused by using a control panel incorporated within the robotic arm system. For example, the display screen can include one or more input sources such as physical buttons or a user interface having one or more icons that are direct movements of the robotic arm 105A. A surgeon or other medical practitioner can engage the one or more input sources to position the robotic arm 105A when performing a surgical procedure.

[0054] The tool or end effector 105B attached to or incorporated into the robotic arm 105A may include, but is not limited to, a deburring device, a female die, a cutting device, a retractor, a joint tension device, etc. In embodiments where the end effector 105B is used, the end effector can be positioned at the end of the robotic arm 105A such that any motor control operations are performed within the robotic arm system. In embodiments where a tool is used, the tool may be fixed to the distal end of the robotic arm 105A, but the motor control operations may also be present within the tool itself.

[0055] The robotic arm 105A may be internally motorized to stabilize both robotic arms, thereby preventing the robotic arms from falling onto and hitting the patient, the operating table, the surgical staff, etc., and enabling the surgeon to move the robotic arm without fully supporting its weight. While the surgeon is moving the robotic arm 105A, the robotic arm may provide some resistance to prevent the robotic arm from moving too fast or having too many degrees of freedom activated at once. The position and locked state of the robotic arm 105A can be tracked, for example, by a controller or a surgical computer 150.

[0056] In some embodiments, the robotic arm 105A can be moved by hand (e.g., by a surgeon) or along with the internal motor into its ideal position and orientation for the task being performed. In some embodiments, the robotic arm 105A can be made operable in a "free" mode that allows the surgeon to position the arm at a desired location without being restricted. During the free mode, the position and orientation of the robotic arm 105A can still be tracked as described above. In some embodiments, a degree of freedom can be selectively released upon input from a user (e.g., a surgeon) during a particular portion of a surgical plan being tracked by the surgical computer 150. A design where the robotic arm 105A is internally powered through hydraulic or motors or provides resistance to external manual movement via similar means can be described as a powered robotic arm, while an arm that is manually treated without power feedback but can be locked in place manually or automatically can be described as a passive robotic arm.

[0057] The robotic arm 105A or the end effector 105B may include a trigger or other means for controlling the power of the saw or drill. Engagement of the trigger or other means by the surgeon can shift the robotic arm 105A or the end effector 105B from an electric alignment mode to a mode in which the saw or drill is engaged and the power is on. Further, the CASS 100 may include a foot pedal (not shown) that causes the system to perform a particular function when activated. For example, the surgeon can activate the foot pedal to instruct the CASS 100 to position the robotic arm 105A or the end effector 105B in an automatic mode in which the robotic arm or end effector is brought to an appropriate position relative to the patient's anatomical structure and the necessary resection is performed. The CASS 100 can also position the robotic arm 105A or the end effector 105B in a collaborative mode that allows the surgeon to manually operate the robotic arm or end effector and position it at a particular location. The collaborative mode can be configured to allow the surgeon to move the robotic arm 105A or the end effector 105B inwardly or outwardly while restricting movement in other directions. As discussed, the robotic arm 105A or the end effector 105B may include a cutting device (saw, drill, and bar), or a cutting guide or jig 105D that guides the cutting device. In other embodiments, the movement of the robotic arm 105A or the robot-controlled end effector 105B can be completely controlled by the CASS 100 without or with minimal assistance or input from the surgeon or other medical professional. In yet other embodiments, the movement of the robotic arm 105A or the robot-controlled end effector 105B can be remotely controlled by the surgeon or other medical professional using, for example, a joystick or an interactive monitor or display control device, using a control mechanism separate from the robotic arm or robot-controlled end effector device.

[0058] Description of Examples The first feature of the disclosed embodiment shown in FIG. 2 is directed to a method by which the broach array 202 and the femur array 204 can be used together to determine the positioning of the broach tool 206 within the femoral canal. The femur array 204, which is attached to the femur at various positions depending on the surgical approach used, establishes a reference frame in which the anatomical structure of the femur is registered. The positioning of the broach tool 206 is performed by detecting the positioning of the broach array 202 connected to the broach tool 206 via the broach adapter 208 relative to the reference frame established by the femur array 204.

[0059] In various disclosed embodiments, the femur array 204 and the broach array 202 can be tracked by sensors that are part of the tracking system 115. The tracking system 115 can communicate with a surgical computer 150 that can receive array tracking data from the tracking system 115 and display the position of the broach tool 206 relative to the femoral canal on the display 125. The reference frame can be established by software running on the surgical computer 153 that scans the position of the femur array 204 relative to the operating room and registers the femur anatomical structure. After broaching, the positioning of the femoral broach tool 206 can be calculated by software running on the surgical computer 150 by receiving data indicating the positioning of the broach array 202 that can be compared to the femur anatomical structure to determine the position of the broach tool 206 within the femoral canal. The final positioning of the broach implant (not shown) can be estimated by the determined position of the broach tool 206.

[0060] The broach adapter 208 is configured to mate with the geometry at the top of the broach tool 206. The broach array 202 is connected to the broach adapter 208 via an array holder 210 that mates with slots on the broach adapter 208, as will be described later. The femur array 204 is connected to the femur via an array holder 212 that consists of a plate 214, a magnetically attached bonding plate, which is attached to the femur as will be described later.

[0061] Figures 3A, 3B, 3C, and 3D show various methods of attaching a femur array to a patient's femur according to an embodiment of the present disclosure. Figures 3A, 3B, 3C, and 3D are different ways of orienting an intramedullary plate used to attach a femur array holder and a femur array to the femur. Different surgical approaches, for example, the supine approach shown in Figure 3A and as shown in Figure 3B, the attachment plate 302 may be attached to the femur at different locations. In one approach, the intramedullary plate 302 is placed on the proximal femur targeting the greater trochanter. Small bone opening screws are placed through the central hole of the attachment plate 302 to fully secure the attachment plate 302 to the femur.

[0062] The array holder 304 shown in FIG. 3C uses patching pins and encapsulated magnets to magnetically engage the array holder 304 to the attachment plate 302. The magnetic connection creates a rigid structure that can be left in place while completing the workflow steps necessary to position the femur, break the femoral canal, and seat the femoral implant within the femur. The magnetic connection allows for the removal and reattachment of the array 306 to the same location, avoiding the need to re-register the array 306 each time it is removed. In various embodiments, the attachment plate 302 may have multiple faces that allow for multiple orientations of the array holder 304. For example, the attachment plate may allow for four connection orientations spaced at 90° intervals. Other numbers of orientations are also contemplated as being within the scope of the disclosed embodiments. The specific face to which the array holder 304 is attached is determined and communicated to the software running on the surgical computer 150 to enable correct calculation of the relative position of the orientation of the array holder 304.

[0063] The femoral array 306 can be secured using the wing screw 308 on top of the array holder 304. The position of the array 306 is maintained throughout the surgery to establish a reference for the femoral anteroposterior workflow steps. The array holder 304 can be configured in different ways to accommodate different surgical procedures. For example, FIG. 3D shows a curved array holder 310.

[0064] Total hip arthroplasty can be achieved using femoral implants and broach tools made by different manufacturers. The femoral broaches made by each manufacturer can have different shapes for attaching tools to the upper part of the broach, for example, an impact tool for pushing the broach tool into the femoral canal. Therefore, the second feature of the disclosed embodiment is to provide different broach adapters configured to fit broach tools with different shapes and firmly attach the broach array to the upper part of the femoral broach tool after broaching to determine the positioning of the broach tool relative to the femur. As described above, the position can be determined by tracking the relative positions of the broach array and the femoral array.

[0065] There are three different current examples of the broach adapters disclosed herein for different families of compatible stems. Each broach adapter utilizes a mechanism that latches onto the broach connection geometry located at the proximal end of the broach tool. The mechanism disclosed herein can mimic the function and geometry of a trial neck device. The broach array is connected to the broach adapter via a spring tab mechanism inserted into a unique slot shape common to the broach adapters disclosed herein.

[0066] In the first embodiment, the broach adapter 400 is provided for attaching a broach array to the upper part of an Anthology broach tool manufactured by Smith and Nephew, Inc. The overall contour of the attachment tool, the latching mechanism, and the post-hole shape, in combination with the anti-rotation tab, mimics the neck of the Anthology broach tool. This connection fully secures the broach adapter to the broach tool in its original position within the femoral canal.

[0067] A side view of the broach adapter 400 is shown in FIG. 4A, with the broach adapter 400 attached to a broach "A", which in this case may be, for example, an Anthology broach tool. A cross-sectional view of the broach adapter 400 is shown in FIG. 4B, showing the interconnection between the broach adapter 400 and the broach tool "A". FIG. 4C shows an exploded view of the broach adapter 400. The broach adapter 400 consists of a body 402 that houses a spring-loaded lever 404 pivotally attached to the body 402 via a pin 408. The lower end of the lever 404 includes a latch 412a that engages a notch 412b of the broach tool "A". A spring 406 holds a hook 412a defined on an end of the lever 404 within the slot 412b until the lever pivots about the pivot point to release the broach adapter 400 from the broach tool "A". The spring 406 is held using a pinned latch (not shown). The blind hole in the body 402 allows the broach adapter 400 to seat against a broach tool "A" where the latch 412a fits within the notch 412b. Further, a tab 414a engages a slot 414b defined on the broach "A" to prevent rotation of the broach adapter 400 relative to the broach tool "A". The broach array holder 450 engages the broach adapter 400 by being inserted into the slot 416 using a mechanism described later herein.

[0068] In a second embodiment, a broach adapter 500 is provided for attaching a broach array to the top of a Memphis-based stem family, including, for example, Synergy, Spectron, previous Anthology broaches, and CPCS broaches. The broach adapter 500 is shown in a side view in FIG. 5A, a cross-sectional view in FIG. 5B, and an exploded view in FIG. 5C.

[0069] The broach adapter 500 uses a spring-loaded latch 504 pivotally attached to the body 502 via a pin 508. The spring-loaded latch 504 captures a ball bearing 510a configured to fit into a notch geometry 510b on the broach tool "B". When the spring-loaded latch 504 is actuated, it releases the ball bearing 510a so that the broach tool "B" can move away from the notch 510b defined on the broach tool "B", enabling removal of the broach adapter 500 from the broach tool "B". In combination with the latch mechanism, a cross pin 512a configured to fit into a U-shaped dowel 512b defined on the broach tool "B" restricts rotation of the broach adapter 500 so that it is fully fixed relative to the broach tool "B". Similar to the example shown in FIGS. 4A, 4B, and 4C, the broach array holder is configured to be inserted into a slot 514 identical to the slot 416 defined in the broach adapter 400.

[0070] In a third embodiment, the broach adapter 600, the figures of FIGS. 6A, 6B, and 6C are for attaching a broach array to the top of Polarstem, SL Plus, and SL MIA implants and broach tools. The latch and pocket insert shapes mimic the existing Polarstem connection broach shape shared across the three aforementioned stem families. The spring-loaded latch and unique pocket insert fully secure the broach adapter to the broach tool. The inner slot allows connection of the array holder shaft.

[0071] A side view of the broach adapter 600 is shown in FIG. 6A, with the broach adapter 600 attached to the broach "C". A cross-sectional view of the broach adapter 600 showing the interconnection between the broach adapter 600 and the broach "C" is shown in FIG. 6B. FIG. 6C shows an exploded view of the broach adapter 600. The broach adapter 600 consists of a body 602 that houses a spring lever 604 pivotally attached to the body 602 via a pin 608. The lower end of the lever 604 includes a hook 612a that engages a slot 612b of the broach tool "C". The spring 606 is retained within the body 602 via a pinned latch and holds the hook 612a defined on the end of the lever 604 in the slot 612b until the lever pivots about the pivot point to release the broach adapter 600 from the broach "C". A protrusion 610a defined on the broach adapter 600 engages a recess 610b defined on the broach "C". The broach array holder engages the broach adapter 600 by being inserted into a slot 614 using a mechanism described later in this specification.

[0072] Various embodiments showing a second feature of the embodiments of the present disclosure, the broach adapter, are described. The mechanism for attaching the broach array holder to the broach adapter is common to three embodiments and future embodiments. This is shown in FIGS. 4A, 4B, 4C, 5A, 5B, 5C, 6A, 6B, 6C as reference numerals 416, 514, and 614 respectively. The mechanism for attaching the broach array holder is shown in a top cross-sectional view in FIG. 7A and a side view in FIG. 7B.

[0073] The mechanism consists of a thin metal arm 702 that defines a protrusion 704 thereon that engages with a recess in the broach adapter. Arms 706 and 708 engage with the broach adapter to define shoulders that prevent tilting or rotation of the broach array holder. The protrusion 704 is spring-engaged with the recess in the broach adapter by the arm 702 that acts as a spring mechanism. When the broach array holder is disengaged from the broach adapter via a pulling motion, the arm 702 moves in the direction of arm 706 to disengage the protrusion 704 from the recess defined within the broach adapter. Conversely, the broach array holder can be re-engaged with the broach adapter via a pushing motion that moves the arm 702 in the direction of arm 706 to enable engagement of the protrusion 704 within the recess defined within the broach adapter.

[0074] In the detailed description above, reference is made to the accompanying drawings that form a part hereof. In the drawings, like symbols typically identify like components unless context dictates otherwise. The illustrative embodiments described herein are not intended to be limiting. Other embodiments may be used and other changes may be made without departing from the spirit or scope of the subject matter presented herein. The various features of the present disclosure may generally be arranged, substituted, combined, separated, and designed in a wide variety of different configurations as described herein and shown in the figures, all of which are explicitly contemplated herein.

[0075] Specific examples of broach adapters are described herein. As would be realized by one of ordinary skill in the art, different broach tools having different geometries may be commercially available and would require broach adapters of different designs. However, all broach adapters are constructed of similar mechanisms, namely, they include a common receptacle for receiving a broach array holder and are configured to be readily removable from the broach tool via a spring mechanism. As would further be realized by one of ordinary skill in the art, specific examples of mechanisms for attaching a broach array holder to a broach adapter are described. However, the disclosed examples are not meant to be limited by the specific examples described herein and are intended to include other examples that perform the same function.

[0076] Accordingly, the present disclosure is not intended to be limited to the specific examples described in this application, which are intended as illustrations of various features. As will be apparent to one of ordinary skill in the art, many modifications and variations can be made without departing from the spirit and scope thereof. In addition to those listed herein, functionally equivalent methods and apparatuses within the scope of the present disclosure will be apparent to one of ordinary skill in the art from the foregoing description. It is to be understood that the present disclosure is not limited to the specific methods, reagents, compounds, compositions, or biological systems, but that they may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular examples only and is not intended to be limiting.

Claims

1. A method for measuring the position of a broach tool in total hip arthroplasty, comprising: attaching a first tracking array to the patient's femur; registering the position of the femur using the tracking array; after breaking the femoral canal, attaching a second tracking array to the broach tool; determining the position of the broach tool relative to the femur based on a comparison of the positions of the first and second tracking arrays.

2. The method according to claim 1, wherein the first tracking array is attached to the femur via a mounting plate that magnetically engages a fitting plate on a holder for the first tracking array.

3. The method according to claim 2, wherein the mounting plate allows for multiple orientations of the first tracking array.

4. The method according to claim 2, wherein the mounting plate is attached to the proximal femur targeting the greater trochanter.

5. Registering the position of the femur includes tracking the first tracking array using a tracking system having one or more sensors for collecting real-time position data, and software executed on a surgical computer calculates and registers the position of the femur based on the position data.

6. Attaching the second tracking array to the broach tool includes providing a broach adapter attached to the broach tool and attaching the second tracking array to the broach adapter.

7. The method according to claim 6, wherein the broach adapter is adapted to conform to the geometric shape of the broach tool.

8. The method according to claim 6, wherein the broach adapter is attached to the broach tool using a spring mechanism.

9. The method according to claim 6, wherein the broach adapter includes a slot adapted to receive a proximal end of a tracking array holder.

10. The method according to claim 9, wherein the proximal end of the tracking array holder includes a spring component having a protrusion thereon that engages a recess defined within the slot of the broach adapter.

11. Comparing the positions of the first and second tracking arrays, using a tracking system having one or more sensors to collect real-time position data of the first and second tracking arrays, and calculating the position of the broach tool relative to the registered position of the femur based on the position data, the method according to claim 1.

12. The method according to claim 11, wherein calculating the position of the broach tool is performed by software executed on a surgical computer.

13. An apparatus for adapting a holder for a tracking array to a broach tool, comprising: a body shaped to conform to the geometric shape of the broach tool; a lever biased by a spring to engage features of the geometric shape of the broach tool; and a slot defined within the body of the apparatus for receiving a holder for a tracking array.

14. The device according to claim 13, wherein the broaching tool is disengaged from the body by rotating the lever so as to disengage the lever from the feature of the geometric shape of the broaching tool with which the lever is engaged.

15. further comprising a holder for a tracking array, the slot defined in the body being adapted to receive a proximal end of the holder for the tracking array, the proximal end including an arm having a protrusion defined thereon that engages a recess defined in the slot, according to claim 13 The device described.

16. The distal end of the holder for the tracking array includes a plurality of arms, at least a portion of the arms defining a shoulder to prevent rotation or tilting of the holder relative to the body, according to claim 15 The device described.

17. The device according to claim 15, wherein the holder for the tracking array is disengaged from the body by bending the arm so that the protrusion is disengaged from the recess defined in the slot.

18. A system, a tracking system having one or more sensors, a processor, software for execution on the processor, the system being using the tracking system to track a first tracking array mechanically connected to the femur and collect real-time position data of the first tracking array to determine the position of the femur, using the tracking system to track a second tracking array mechanically connected to the broaching tool and collect real-time position data of the second tracking array to determine the position of the broaching tool disposed within the femoral canal of the femur, A system in which the software calculates the position of the broaching tool relative to the femur based on a comparison of the position data representing the positions of the first and second tracking arrays.

Images