105A may be mounted directly to the table T, be located next to the table T on a floor platform (not shown), mounted on a floor-to-ceiling pole, or mounted on a wall or ceiling of an operating room. The floor platform may be fixed or moveable. In one particular embodiment, the robotic arm 105A is mounted on a floor-to-ceiling pole located between the patient's legs or feet. In some embodiments, the End Effector 105B may include a suture holder or a stapler to assist in closing wounds. Further, in the case of two robotic arms 105A, the surgical computer 150 can drive the robotic arms 105A to work together to suture the wound at closure. Alternatively, the surgical computer 150 can drive one or more robotic arms 105A to staple the wound at closure.

The Effector Platform 105 can include a Limb Positioner 105C for positioning the patient's limbs during surgery. One example of a Limb Positioner 105C is the SMITH AND NEPHEW SPIDER2 system. The Limb Positioner 105C may be operated manually by the surgeon or alternatively change limb positions based on instructions received from the Surgical Computer 150 (described below). While one Limb Positioner 105C is illustrated in FIG. 1, in some embodiments there may be multiple devices. As examples, there may be one Limb Positioner 105C on each side of the operating table T or two devices on one side of the table T. The Limb Positioner 105C may be mounted directly to the table T, be located next to the table T on a floor platform (not shown), mounted on a pole, or mounted on a wall or ceiling of an operating room. In some embodiments, the Limb Positioner 105C can be used in non-conventional ways, such as a retractor or specific bone holder. The Limb Positioner 105C may include, as examples, an ankle boot, a soft tissue clamp, a bone clamp, or a soft-tissue retractor spoon, such as a hooked, curved, or angled blade. In some embodiments, the Limb Positioner 105C may include a suture holder to assist in closing wounds.

The Effector Platform 105 may include tools, such as a screwdriver, light or laser, to indicate an axis or plane, bubble level, pin driver, pin puller, plane checker, pointer, finger, or some combination thereof.

Resection Equipment 110 (not shown in FIG. 1) performs bone or tissue resection using, for example, mechanical, ultrasonic, or laser techniques. Examples of Resection Equipment 110 include drilling devices, burring devices, oscillatory sawing devices, vibratory impaction devices, reamers, ultrasonic bone cutting devices, radio frequency ablation devices, reciprocating devices (such as a rasp or broach), and laser ablation systems. In some embodiments, the Resection Equipment 110 is held and operated by the surgeon during surgery. In other embodiments, the Effector Platform 105 may be used to hold the Resection Equipment 110 during use.

The Effector Platform 105 also can include a cutting guide or jig 105D that is used to guide saws or drills used to resect tissue during surgery. Such cutting guides 105D can be formed integrally as part of the Effector Platform 105 or Robotic Arm 105A, or cutting guides can be separate structures that can be matingly and/or removably attached to the Effector Platform 105 or Robotic Arm 105A. The Effector Platform 105 or Robotic Arm 105A can be controlled by the CASS 100 to position a cutting guide or jig 105D adjacent to the patient's anatomy in accordance with a pre-operatively or intraoperatively developed surgical plan such that the cutting guide or jig will produce a precise bone cut in accordance with the surgical plan.

The Tracking System 115 uses one or more sensors to collect real-time position data that locates the patient's anatomy and surgical instruments. For example, for TKA procedures, the Tracking System may provide a location and orientation of the End Effector 105B during the procedure. In addition to positional data, data from the Tracking System 115 also can be used to infer velocity/acceleration of anatomy/instrumentation, which 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 may be inferred based on the position and orientation of the Tracking System 115 and a known relationship in three-dimensional space between the Tracking System 115 and the End Effector 105B. Various types of tracking systems may be used in various embodiments of the present invention including, without limitation, Infrared (IR) tracking systems, electromagnetic (EM) tracking systems, video or image based tracking systems, and ultrasound registration and tracking systems. Using the data provided by the tracking system 115, the surgical computer 150 can detect objects and prevent collision. For example, the surgical computer 150 can prevent the Robotic Arm 105A and/or the End Effector 105B from colliding with soft tissue.

Any suitable tracking system can be used for tracking surgical objects and patient anatomy in the surgical theatre. For example, a combination of IR and visible light cameras can be used in an array. Various illumination sources, such as an IR LED light source, can illuminate the scene allowing three-dimensional imaging to occur. In some embodiments, this can include stereoscopic, tri-scopic, quad-scopic, etc. imaging. In addition to the camera array, which in some embodiments is affixed to a cart, additional cameras can be placed throughout the surgical theatre. For example, handheld tools or headsets worn by operators/surgeons can include imaging capability that communicates images back to a central processor to correlate those images with images captured by the camera array. This can give a more robust image of the environment for modeling using multiple perspectives. Furthermore, some imaging devices may be of suitable resolution or have a suitable perspective on the scene to pick up information stored in quick response (QR) codes or barcodes. This can be helpful in identifying specific objects not manually registered with the system. In some embodiments, the camera may be mounted on the Robotic Arm 105A.

Although, as discussed herein, the majority of tracking and/or navigation techniques utilize image-based tracking systems (e.g., IR tracking systems, video or image based tracking systems, etc.). However, electromagnetic (EM) based tracking systems are becoming more common for a variety of reasons. For example, implantation of standard optical trackers requires tissue resection (e.g., down to the cortex) as well as subsequent drilling and driving of cortical pins. Additionally, because optical trackers require a direct line of sight with a tracking system, the placement of such trackers may need to be far from the surgical site to ensure they do not restrict the movement of a surgeon or medical professional.

Generally, EM based tracking devices include one or more wire coils and a reference field generator. The one or more wire coils may be energized (e.g., via a wired or wireless power supply). Once energized, the coil creates an electromagnetic field that can be detected and measured (e.g., by the reference field generator or an additional device) in a manner that allows for the location and orientation of the one or more wire coils to be determined. As should be understood by someone of ordinary skill in the art, a single coil, such as is shown in FIG. 2, is limited to detecting five (5) total degrees-of-freedom (DOF). For example, sensor 200 may be able to track/determine movement in the X, Y, or Z direction, as well as rotation around the Y-axis 202 or Z-axis 201. However, because of the electromagnetic properties of a coil, it is not possible to properly track rotational movement around the X axis.

Accordingly, in most electromagnetic tracking applications, a three coil system, such as that shown in FIG. 3A is used to enable tracking in all six degrees of freedom that are possible for a rigid body moving in a three-dimensional space (i.e., forward/backward 310, up/down 320, left/right 330, roll 340, pitch 350, and yaw 360). However, the inclusion of two additional coils and the 90° offset angles at which they are positioned may require the tracking device to be much larger. Alternatively, as one of skill in the art would know, less than three full coils may be used to track all 6DOF. In some EM based tracking devices, two coils may be affixed to each other, such as is shown in FIG. 3B. Because the two coils 301B and 302B are rigidly affixed to each other, not perfectly parallel, and have locations that are known relative to each other, it is possible to determine the sixth degree of freedom 303B with this arrangement.

Although the use of two affixed coils (e.g., 301B and 302B) allows for EM based tracking in 6DOF, the sensor device is substantially larger in diameter than a single coil because of the additional coil. Thus, the practical application of using an EM based tracking system in a surgical environment may require tissue resection and drilling of a portion of the patient bone to allow for insertion of a EM tracker. Alternatively, in some embodiments, it may be possible to implant/insert a single coil, or 5DOF EM tracking device, into a patient bone using only a pin (e.g., without the need to drill or carve out substantial bone).

Thus, as described herein, a solution is needed for which the use of an EM tracking system can be restricted to devices small enough to be inserted/embedded using a small diameter needle or pin (i.e., without the need to create a new incision or large diameter opening in the bone). Accordingly, in some embodiments, a second 5DOF sensor, which is not attached to the first, and thus has a small diameter, may be used to track all 6DOF. Referring now to FIG. 3C, in some embodiments, two 5DOF EM sensors (e.g., 301C and 302C) may be inserted into the patient (e.g., in a patient bone) at different locations and with different angular orientations (e.g., angle 303C is non-zero).

Referring now to FIG. 4, an example embodiment is shown in which a first 5DOF EM sensor 401 and a second 5DOF EM sensor 402 are inserted into the patient bone 403 using a standard hollow needle 405 that is typical in most OR(s). In a further embodiment, the first sensor 401 and the second sensor 402 may have an angle offset of “a” 404. In some embodiments, it may be necessary for the offset angle “a” 404 to be greater than a predetermined value (e.g., a minimum angle of 0.50°, 0.75°, etc.). This minimum value may, in some embodiments, be determined by the CASS and provided to the surgeon or medical professional during the surgical plan. In some embodiments, a minimum value may be based on one or more factors, such as, for example, the orientation accuracy of the tracking system, a distance between the first and second EM sensors. The location of the field generator, a location of the field detector, a type of EM sensor, a quality of the EM sensor, patient anatomy, and the like.

Accordingly, as discussed herein, in some embodiments, a pin/needle (e.g., a cannulated mounting needle, etc.) may be used to insert one or more EM sensors. Generally, the pin/needle would be a disposable component, while the sensors themselves may be reusable. However, it should be understood that this is only one potential system, and that various other systems may be used in which the pin/needle and/or EM sensors are independently disposable or reusable. In a further embodiment, the EM sensors may be affixed to the mounting needle/pin (e.g., using a luer-lock fitting or the like), which can allow for quick assembly and disassembly. In additional embodiments, the EM sensors may utilize an alternative sleeve and/or anchor system that allows for minimally invasive placement of the sensors.

In another embodiment, the above systems may allow for a multi-sensor navigation system that can detect and correct for field distortions that plague electromagnetic tracking systems. It should be understood that field distortions may result from movement of any ferromagnetic materials within the reference field. Thus, as one of ordinary skill in the art would know, a typical OR has a large number of devices (e.g., an operating table, LCD displays, lighting equipment, imaging systems, surgical instruments, etc.) that may cause interference. Furthermore, field distortions are notoriously difficult to detect. The use of multiple EM sensors enables the system to detect field distortions accurately, and/or to warn a user that the current position measurements may not be accurate. Because the sensors are rigidly fixed to the bony anatomy (e.g., via the pin/needle), relative measurement of sensor positions (X, Y, Z) may be used to detect field distortions. By way of non-limiting example, in some embodiments, after the EM sensors are fixed to the bone, the relative distance between the two sensors is known and should remain constant. Thus, any change in this distance could indicate the presence of a field distortion.

In some embodiments, specific objects can be manually registered by a surgeon with the system preoperatively or intraoperatively. For example, by interacting with a user interface, a surgeon may identify the starting location for 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, a processor may track that tool or bone as it moves through the environment in a three-dimensional model.

In some embodiments, certain markers, such as fiducial marks that identify individuals, important tools, or bones in the theater 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 flash a pattern that conveys a unique identifier to the source of that pattern, providing a dynamic identification mark. Similarly, one or two dimensional optical codes (barcode, QR code, etc.) can be affixed to objects in the theater to provide passive identification that can occur based on image analysis. If these codes are placed asymmetrically on an object, they also can be used to determine an orientation of an object by comparing the location of the identifier with the extents of an object in an image. For example, a QR code may be placed in a corner of a tool tray, allowing the orientation and identity of that tray to be tracked. Other tracking modalities are explained throughout. For example, in some embodiments, augmented reality headsets can be worn by surgeons and other staff to provide additional camera angles and tracking capabilities.

In addition to optical tracking, certain features of objects can be tracked by registering physical properties of the object and associating them with objects that can be tracked, such as fiducial marks fixed to a tool or bone. For example, a surgeon may perform a manual registration process whereby a tracked tool and a tracked bone can be manipulated relative to one another. By impinging the tip of the tool against the surface of the bone, a three-dimensional surface can be mapped for that bone that is associated with a position and orientation relative to the frame of reference of that fiducial mark. By optically tracking the position and orientation (pose) of the fiducial mark associated with that bone, a model of that surface can be tracked with an environment through extrapolation.

The registration process that registers the CASS 100 to the relevant anatomy of the patient also can involve the use of anatomical landmarks, such as landmarks on a bone or cartilage. For example, the CASS 100 can include a 3D model of the relevant bone or joint and the surgeon can intraoperatively collect data regarding the location of bony landmarks on the patient's actual bone using a probe that is connected to the CASS. Bony landmarks can include, for example, the medial malleolus and lateral malleolus, 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 bony landmarks collected by the surgeon with the probe with 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 without pre-operative image data by using location data of bony landmarks and the bone surface that are collected by the surgeon using a CASS probe or other means. The registration process also can include determining various axes of a joint. For example, for a 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 spiral direction (i.e., circumduction) so the CASS can determine where the center of the hip joint is located.

A Tissue Navigation System 120 (not shown in FIG. 1) provides the surgeon with intraoperative, real-time visualization for the patient's bone, cartilage, muscle, nervous, and/or vascular tissues surrounding the surgical area. Examples of systems that may be employed for tissue navigation include fluorescent imaging systems and ultrasound systems.

The Display 125 provides graphical user interfaces (GUIs) that display images collected by the Tissue Navigation System 120 as well other information relevant to the surgery. For example, in one embodiment, the Display 125 overlays image information collected from various modalities (e.g., CT, MRI, X-ray, fluorescent, ultrasound, etc.) collected pre-operatively or intra-operatively to give the surgeon various views of the patient's anatomy as well as real-time conditions. The Display 125 may 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 may, for example, overlay pre-operative image data on the patient or provide surgical planning suggestions. Various example uses of the AR HMD 155 in surgical procedures are detailed in the sections that follow.

Surgical Computer 150 provides control instructions to various components of the CASS 100, collects data from those components, and provides general processing for various data needed during surgery. In some embodiments, the Surgical Computer 150 is a general purpose computer. In other embodiments, the Surgical Computer 150 may be a parallel computing platform that uses multiple central processing units (CPUs) or graphics processing units (GPU) to perform processing. In some embodiments, the Surgical Computer 150 is connected to a remote server over one or more computer networks (e.g., the Internet). The remote server can be used, for example, for storage of data or execution of computationally intensive processing tasks.

Various techniques generally known in the art can be used for connecting the Surgical Computer 150 to the other components of the CASS 100. Moreover, the computers can connect to the Surgical Computer 150 using a mix of technologies. For example, the End Effector 105B may connect to the Surgical Computer 150 over a wired (i.e., serial) connection. The Tracking System 115, Tissue Navigation System 120, and Display 125 can similarly be connected to the Surgical Computer 150 using wired connections. Alternatively, the Tracking System 115, Tissue Navigation System 120, and Display 125 may connect to the Surgical Computer 150 using wireless technologies such as, without limitation, Wi-Fi, Bluetooth, Near Field Communication (NFC), or ZigBee.

Powered Impaction and Acetabular Reamer Devices

Part of the flexibility of the CASS design described above with respect to FIG. 1 is that additional or alternative devices can be added to the CASS 100 as necessary to support particular surgical procedures. For example, in the context of hip surgeries, the CASS 100 may include a powered impaction device. Impaction devices are designed to repeatedly apply an impaction force that the surgeon can use to perform activities such as implant alignment. For example, within a total hip arthroplasty (THA), a surgeon will often insert a prosthetic acetabular cup into the implant host's acetabulum using an impaction device. Although impaction devices can be manual in nature (e.g., operated by the surgeon striking an impactor with a mallet), powered impaction devices are generally easier and quicker to use in the surgical setting. Powered impaction devices may be powered, for example, using a battery attached to the device. Various attachment pieces may be connected to the powered impaction device to allow the impaction force to be directed in various ways as needed during surgery. Also, in the context of hip surgeries, the CASS 100 may include a powered, robotically controlled end effector to ream the acetabulum to accommodate an acetabular cup implant.

In a robotically-assisted THA, the patient's anatomy can be registered to the CASS 100 using CT or other image data, the identification of anatomical landmarks, tracker arrays attached to the patient's bones, and one or more cameras. Tracker arrays can be mounted on the iliac crest using clamps and/or bone pins and such trackers can be mounted externally through the skin or internally (either posterolaterally or anterolaterally) through the incision made to perform the THA. For a THA, the CASS 100 can utilize one or more femoral cortical screws inserted into the proximal femur as checkpoints to aid in the registration process. The CASS 100 also can utilize one or more checkpoint screws inserted into the pelvis as additional checkpoints to aid in the registration process. Femoral tracker arrays can be secured to or mounted in the femoral cortical screws. The CASS 100 can employ steps where the registration is verified using a probe that the surgeon precisely places on key areas of the proximal femur and pelvis identified for the surgeon on the display 125. Trackers can be located on the robotic arm 105A or end effector 105B to register the arm and/or end effector to the CASS 100. The verification step also can utilize proximal and distal femoral checkpoints. The CASS 100 can utilize color prompts or other prompts to inform the surgeon that the registration process for the relevant bones and the robotic arm 105A or end effector 105B has been verified to a certain degree of accuracy (e.g., within 1 mm).

For a THA, the CASS 100 can include a broach tracking option using femoral arrays to allow the surgeon to intraoperatively capture the broach position and orientation and calculate hip length and offset values for the patient. Based on information provided about the patient's hip joint and the planned implant position and orientation after broach tracking is completed, the surgeon can make modifications or adjustments to the surgical plan.

For a robotically-assisted THA, the CASS 100 can include one or more powered reamers connected or attached to a robotic arm 105A or end effector 105B that prepares the pelvic bone to receive an acetabular implant according to a surgical plan. The robotic arm 105A and/or end effector 105B can inform the surgeon and/or control the power of the reamer to ensure that the acetabulum is being resected (reamed) in accordance with the surgical plan. For example, if the surgeon attempts to resect bone outside of the boundary of the bone to be resected in accordance with the surgical plan, the CASS 100 can power off the reamer or instruct the surgeon to power off the reamer. The CASS 100 can provide the surgeon with an option to turn off or disengage the robotic control of the reamer. The display 125 can depict the progress of the bone being resected (reamed) as compared to the surgical plan using different colors. The surgeon can view the display of the bone being resected (reamed) to guide the reamer to complete the reaming in accordance with the surgical plan. The CASS 100 can provide visual or audible prompts to the surgeon to warn the surgeon that resections are being made that are not in accordance with the surgical plan.

Following reaming, the CASS 100 can employ a manual or powered impactor that is attached or connected to the robotic arm 105A or end effector 105B to impact trial implants and final implants into the acetabulum. The robotic arm 105A and/or end effector 105B can be used to guide the impactor to impact the trial and final implants into the acetabulum in accordance with the surgical plan. The CASS 100 can cause the position and orientation of the trial and final implants vis-à-vis the bone to be displayed to inform the surgeon as to how the trial and final implant's orientation and position compare to the surgical plan, and the display 125 can show the implant's position and orientation as the surgeon manipulates the leg and hip. The CASS 100 can provide the surgeon with the option of re-planning and re-doing the reaming and implant impaction by preparing a new surgical plan if the surgeon is not satisfied with the original implant position and orientation.

Preoperatively, the CASS 100 can develop a proposed surgical plan based on a three dimensional model of the hip joint and other information specific to the patient, such as the mechanical and anatomical axes of the leg bones, the epicondylar axis, the femoral neck axis, the dimensions (e.g., length) of the femur and hip, the midline axis of the hip joint, the ASIS axis of the hip joint, and the location of anatomical landmarks such as the lesser trochanter landmarks, the distal landmark, and the center of rotation of the hip joint. The CASS-developed surgical plan can provide a recommended optimal implant size and implant position and orientation based on the three dimensional model of the hip joint and other information specific to the patient. The CASS-developed surgical plan can include proposed details on offset values, inclination and anteversion values, center of rotation, cup size, medialization values, superior-inferior fit values, femoral stem sizing and length.

For a THA, the CASS-developed surgical plan can be viewed preoperatively and intraoperatively, and the surgeon can modify CASS-developed surgical plan preoperatively or intraoperatively. The CASS-developed surgical plan can display the planned resection to the hip joint and superimpose the planned implants onto the hip joint based on the planned resections. The CASS 100 can provide the surgeon with options for different surgical workflows that will be displayed to the surgeon based on a surgeon's preference. For example, the surgeon can choose from different workflows based on the number and types of anatomical landmarks that are checked and captured and/or the location and number of tracker arrays used in the registration process.

According to some embodiments, a powered impaction device used with the CASS 100 may operate with a variety of different settings. In some embodiments, the surgeon adjusts settings through a manual switch or other physical mechanism on the powered impaction device. In other embodiments, a digital interface may be used that allows setting entry, for example, via a touchscreen on the powered impaction device. Such a digital interface may allow the available settings to vary based, for example, on the type of attachment piece connected to the power attachment device. In some embodiments, rather than adjusting the settings on the powered impaction device itself, the settings can be changed through communication with a robot or other computer system within the CASS 100. Such connections may be established using, for example, a Bluetooth or Wi-Fi networking module on the powered impaction device. In another embodiment, the impaction device and end pieces may contain features that allow the impaction device to be aware of what end piece (cup impactor, broach handle, etc.) is attached with no action required by the surgeon, and adjust the settings accordingly. This may be achieved, for example, through a QR code, barcode, RFID tag, or other method.

Examples of the settings that may be used include cup impaction settings (e.g., single direction, specified frequency range, specified force and/or energy range); broach impaction settings (e.g., dual direction/oscillating at a specified frequency range, specified force and/or energy range); femoral head impaction settings (e.g., single direction/single blow at a specified force or energy); and stem impaction settings (e.g., single direction at specified frequency with a specified force or energy). Additionally, in some embodiments, the powered impaction device includes settings related to acetabular liner impaction (e.g., single direction/single blow at a specified force or energy). There may be a plurality of settings for each type of liner such as poly, ceramic, oxinium, or other materials. Furthermore, the powered impaction device may offer settings for different bone quality based on preoperative testing/imaging/knowledge and/or intraoperative assessment by surgeon. In some embodiments, the powered impactor device may have a dual function. For example, the powered impactor device not only could provide reciprocating motion to provide an impact force, but also could provide reciprocating motion for a broach or rasp.

In some embodiments, the powered impaction device includes feedback sensors that gather data during instrument use and send data to a computing device, such as a controller within the device or the Surgical Computer 150. This computing device can then record the data for later analysis and use. Examples of the data that may be collected include, without limitation, sound waves, the predetermined resonance frequency of each instrument, reaction force or rebound energy from patient bone, location of the device with respect to imaging (e.g., fluoro, CT, ultrasound, MRI, etc.) registered bony anatomy, and/or external strain gauges on bones.

Once the data is collected, the computing device may execute one or more algorithms in real-time or near real-time to aid the surgeon in performing the surgical procedure. For example, in some embodiments, the computing device uses the collected data to derive information such as the proper final broach size (femur); when the stem is fully seated (femur side); or when the cup is seated (depth and/or orientation) for a THA. Once the information is known, it may be displayed for the surgeon's review, or it may be used to activate haptics or other feedback mechanisms to guide the surgical procedure.

Additionally, the data derived from the aforementioned algorithms may be used to drive operation of the device. For example, during insertion of a prosthetic acetabular cup with a powered impaction device, the device may automatically extend an impaction head (e.g., an end effector) moving the implant into the proper location, or turn the power off to the device once the implant is fully seated. In one embodiment, the derived information may be used to automatically adjust settings for quality of bone where the powered impaction device should use less power to mitigate femoral/acetabular/pelvic fracture or damage to surrounding tissues.

Robotic Arm

In some embodiments, the CASS 100 includes a robotic arm 105A that serves as an interface to stabilize and hold a variety of instruments used during the surgical procedure. For example, in the context of a hip surgery, these instruments may include, without limitation, retractors, a sagittal or reciprocating saw, the reamer handle, the cup impactor, the broach handle, and the stem inserter. The robotic arm 105A may have multiple degrees of freedom (like a Spider device), and have the ability to be locked in place (e.g., by a press of a button, voice activation, a surgeon removing a hand from the robotic arm, or other method).

In some embodiments, movement of the robotic arm 105A may be effectuated by use of a control panel built into the robotic arm system. For example, a display screen may include one or more input sources, such as physical buttons or a user interface having one or more icons, that direct movement of the robotic arm 105A. The surgeon or other healthcare professional may engage with the one or more input sources to position the robotic arm 105A when performing a surgical procedure.

A tool or an end effector 105B attached or integrated into a robotic arm 105A may include, without limitation, a burring device, a scalpel, a cutting device, a retractor, a joint tensioning device, or the like. In embodiments in which an end effector 105B is used, the end effector may 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 in which a tool is used, the tool may be secured at a distal end of the robotic arm 105A, but motor control operation may reside within the tool itself.

The robotic arm 105A may be motorized internally to both stabilize the robotic arm, thereby preventing it from falling and hitting the patient, surgical table, surgical staff, etc., and to allow the surgeon to move the robotic arm without having to fully support 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 active at once. The position and the lock status of the robotic arm 105A may be tracked, for example, by a controller or the Surgical Computer 150.

In some embodiments, the robotic arm 105A can be moved by hand (e.g., by the surgeon) or with internal motors into its ideal position and orientation for the task being performed. In some embodiments, the robotic arm 105A may be enabled to operate in a “free” mode that allows the surgeon to position the arm into a desired position without being restricted. While in the free mode, the position and orientation of the robotic arm 105A may still be tracked as described above. In one embodiment, certain degrees of freedom can be selectively released upon input from user (e.g., surgeon) during specified portions of the surgical plan tracked by the Surgical Computer 150. Designs in which a robotic arm 105A is internally powered through hydraulics or motors or provides resistance to external manual motion through similar means can be described as powered robotic arms, while arms that are manually manipulated without power feedback, but which may be manually or automatically locked in place, may be described as passive robotic arms.

A robotic arm 105A or end effector 105B can include a trigger or other means to control the power of a saw or drill. Engagement of the trigger or other means by the surgeon can cause the robotic arm 105A or end effector 105B to transition from a motorized alignment mode to a mode where the saw or drill is engaged and powered on. Additionally, the CASS 100 can include a foot pedal (not shown) that causes the system to perform certain functions when activated. For example, the surgeon can activate the foot pedal to instruct the CASS 100 to place the robotic arm 105A or end effector 105B in an automatic mode that brings the robotic arm or end effector into the proper position with respect to the patient's anatomy in order to perform the necessary resections. The CASS 100 also can place the robotic arm 105A or end effector 105B in a collaborative mode that allows the surgeon to manually manipulate and position the robotic arm or end effector into a particular location. The collaborative mode can be configured to allow the surgeon to move the robotic arm 105A or end effector 105B medially or laterally, while restricting movement in other directions. As discussed, the robotic arm 105A or end effector 105B can include a cutting device (saw, drill, and burr) or a cutting guide or jig 105D that will guide a cutting device. In other embodiments, movement of the robotic arm 105A or robotically controlled end effector 105B can be controlled entirely by the CASS 100 without any, or with only minimal, assistance or input from a surgeon or other medical professional. In still other embodiments, the movement of the robotic arm 105A or robotically controlled end effector 105B can be controlled remotely by a surgeon or other medical professional using a control mechanism separate from the robotic arm or robotically controlled end effector device, for example using a joystick or interactive monitor or display control device.

The examples below describe uses of the robotic device in the context of a hip surgery; however, it should be understood that the robotic arm may have other applications for surgical procedures involving knees, shoulders, etc. One example of use of a robotic arm in the context of forming an anterior cruciate ligament (ACL) graft tunnel is described in WIPO Publication No. WO 2020/047051, filed Aug. 28, 2019, entitled “Robotic Assisted Ligament Graft Placement and Tensioning,” the entirety of which is incorporated herein by reference.

A robotic arm 105A may be used for holding the retractor. For example in one embodiment, the robotic arm 105A may be moved into the desired position by the surgeon. At that point, the robotic arm 105A may lock into place. In some embodiments, the robotic arm 105A is provided with data regarding the patient's position, such that if the patient moves, the robotic arm can adjust the retractor position accordingly. In some embodiments, multiple robotic arms may be used, thereby allowing multiple retractors to be held or for more than one activity to be performed simultaneously (e.g., retractor holding & reaming).

The robotic arm 105A may also be used to help stabilize the surgeon's hand while making a femoral neck cut. In this application, control of the robotic arm 105A may impose certain restrictions to prevent soft tissue damage from occurring. For example, in one embodiment, the Surgical Computer 150 tracks the position of the robotic arm 105A as it operates. If the tracked location approaches an area where tissue damage is predicted, a command may be sent to the robotic arm 105A causing it to stop. Alternatively, where the robotic arm 105A is automatically controlled by the Surgical Computer 150, the Surgical Computer may ensure that the robotic arm is not provided with any instructions that cause it to enter areas where soft tissue damage is likely to occur. The Surgical Computer 150 may impose certain restrictions on the surgeon to prevent the surgeon from reaming too far into the medial wall of the acetabulum or reaming at an incorrect angle or orientation.

In some embodiments, the robotic arm 105A may be used to hold a cup impactor at a desired angle or orientation during cup impaction. When the final position has been achieved, the robotic arm 105A may prevent any further seating to prevent damage to the pelvis.

The surgeon may use the robotic arm 105A to position the broach handle at the desired position and allow the surgeon to impact the broach into the femoral canal at the desired orientation. In some embodiments, once the Surgical Computer 150 receives feedback that the broach is fully seated, the robotic arm 105A may restrict the handle to prevent further advancement of the broach.

The robotic arm 105A may also be used for resurfacing applications. For example, the robotic arm 105A may stabilize the surgeon while using traditional instrumentation and provide certain restrictions or limitations to allow for proper placement of implant components (e.g., guide wire placement, chamfer cutter, sleeve cutter, plan cutter, etc.). Where only a burr is employed, the robotic arm 105A may stabilize the surgeon's handpiece and may impose restrictions on the handpiece to prevent the surgeon from removing unintended bone in contravention of the surgical plan.

The robotic arm 105A may be a passive arm. As an example, the robotic arm 105A may be a CIRQ robot arm available from Brainlab AG. CIRQ is a registered trademark of Brainlab AG, Olof-Palme-Str. 9 81829, Munchen, FED REP of GERMANY. In one particular embodiment, the robotic arm 105A is an intelligent holding arm as disclosed in U.S. patent application Ser. No. 15/525,585 to Krinninger et al., U.S. patent application Ser. No. 15/561,042 to Nowatschin et al., U.S. patent application Ser. No. 15/561,048 to Nowatschin et al., and U.S. Pat. No. 10,342,636 to Nowatschin et al., the entire contents of each of which is herein incorporated by reference.

Surgical Procedure Data Generation and Collection

The various services that are provided by medical professionals to treat a clinical condition are collectively referred to as an “episode of care.” For a particular surgical intervention the episode of care can include three phases: pre-operative, intra-operative, and post-operative. During each phase, data is collected or generated that can be used to analyze the episode of care in order to understand various features of the procedure and identify patterns that may be used, for example, in training models to make decisions with minimal human intervention. The data collected over the episode of care may be stored at the Surgical Computer 150 or the Surgical Data Server 180 as a complete dataset. Thus, for each episode of care, a dataset exists that comprises all of the data collectively pre-operatively about the patient, all of the data collected or stored by the CASS 100 intra-operatively, and any post-operative data provided by the patient or by a healthcare professional monitoring the patient.

As explained in further detail, the data collected during the episode of care may be used to enhance performance of the surgical procedure or to provide a holistic understanding of the surgical procedure and the patient outcomes. For example, in some embodiments, the data collected over the episode of care may be used to generate a surgical plan. In one embodiment, a high-level, pre-operative plan is refined intra-operatively as data is collected during surgery. In this way, the surgical plan can be viewed as dynamically changing in real-time or near real-time as new data is collected by the components of the CASS 100. In other embodiments, pre-operative images or other input data may be used to develop a robust plan preoperatively that is simply executed during surgery. In this case, the data collected by the CASS 100 during surgery may be used to make recommendations that ensure that the surgeon stays within the pre-operative surgical plan. For example, if the surgeon is unsure how to achieve a certain prescribed cut or implant alignment, the Surgical Computer 150 can be queried for a recommendation. In still other embodiments, the pre-operative and intra-operative planning approaches can be combined such that a robust pre-operative plan can be dynamically modified, as necessary or desired, during the surgical procedure. In some embodiments, a biomechanics-based model of patient anatomy contributes simulation data to be considered by the CASS 100 in developing preoperative, intraoperative, and post-operative/rehabilitation procedures to optimize implant performance outcomes for the patient.

Aside from changing the surgical procedure itself, the data gathered during the episode of care may be used as an input to other procedures ancillary to the surgery. For example, in some embodiments, implants can be designed using episode of care data. Example data-driven techniques for designing, sizing, and fitting implants are described in U.S. patent application Ser. No. 13/814,531 filed Aug. 15, 2011 and entitled “Systems and Methods for Optimizing Parameters for Orthopaedic Procedures”; U.S. patent application Ser. No. 14/232,958 filed Jul. 20, 2012 and entitled “Systems and Methods for Optimizing Fit of an Implant to Anatomy”; and U.S. patent application Ser. No. 12/234,444 filed Sep. 19, 2008 and entitled “Operatively Tuning Implants for Increased Performance,” the entire contents of each of which are hereby incorporated by reference into this patent application.

Furthermore, the data can be used for educational, training, or research purposes. For example, using the network-based approach described below in FIG. 5C, other doctors or students can remotely view surgeries in interfaces that allow them to selectively view data as it is collected from the various components of the CASS 100. After the surgical procedure, similar interfaces may be used to “playback” a surgery for training or other educational purposes, or to identify the source of any issues or complications with the procedure.

Data acquired during the pre-operative phase generally includes all information collected or generated prior to the surgery. Thus, for example, information about the patient may be acquired from a patient intake form or electronic medical record (EMR). Examples of patient information that may be collected include, without limitation, patient demographics, diagnoses, medical histories, progress notes, vital signs, medical history information, allergies, and lab results. The pre-operative data may also include images related to the anatomical area of interest. These images may be captured, for example, using Magnetic Resonance Imaging (MRI), Computed Tomography (CT), X-ray, ultrasound, or any other modality known in the art. The pre-operative data may also comprise quality of life data captured from the patient. For example, in one embodiment, pre-surgery patients use a mobile application (“app”) to answer questionnaires regarding their current quality of life. In some embodiments, preoperative data used by the CASS 100 includes demographic, anthropometric, cultural, or other specific traits about a patient that can coincide with activity levels and specific patient activities to customize the surgical plan to the patient. For example, certain cultures or demographics may be more likely to use a toilet that requires squatting on a daily basis.

FIGS. 5A and 5B provide examples of data that may be acquired during the intra-operative phase of an episode of care. These examples are based on the various components of the CASS 100 described above with reference to FIG. 1; however, it should be understood that other types of data may be used based on the types of equipment used during surgery and their use.

FIG. 5A shows examples of some of the control instructions that the Surgical Computer 150 provides to other components of the CASS 100, according to some embodiments. Note that the example of FIG. 5A assumes that the components of the Effector Platform 105 are each controlled directly by the Surgical Computer 150. In embodiments where a component is manually controlled by the Surgeon 111, instructions may be provided on the Display 125 or AR HMD 155 instructing the Surgeon 111 how to move the component.

The various components included in the Effector Platform 105 are controlled by the Surgical Computer 150 providing position commands that instruct the component where to move within a coordinate system. In some embodiments, the Surgical Computer 150 provides the Effector Platform 105 with instructions defining how to react when a component of the Effector Platform 105 deviates from a surgical plan. These commands are referenced in FIG. 5A as “haptic” commands. For example, the End Effector 105B may provide a force to resist movement outside of an area where resection is planned. Other commands that may be used by the Effector Platform 105 include vibration and audio cues.

In some embodiments, the end effectors 105B of the robotic arm 105A are operatively coupled with cutting guide 105D. In response to an anatomical model of the surgical scene, the robotic arm 105A can move the end effectors 105B and the cutting guide 105D into position to match the location of the femoral or tibial cut to be performed in accordance with the surgical plan. This can reduce the likelihood of error, allowing the vision system and a processor utilizing that vision system to implement the surgical plan to place a cutting guide 105D at the precise location and orientation relative to the tibia or femur to align a cutting slot of the cutting guide with the cut to be performed according to the surgical plan. Then, a surgeon can use any suitable tool, such as an oscillating or rotating saw or drill to perform the cut (or drill a hole) with perfect placement and orientation because the tool is mechanically limited by the features of the cutting guide 105D. In some embodiments, the cutting guide 105D may include one or more pin holes that are used by a surgeon to drill and screw or pin the cutting guide into place before performing a resection of the patient tissue using the cutting guide. This can free the robotic arm 105A or ensure that the cutting guide 105D is fully affixed without moving relative to the bone to be resected. For example, this procedure can be used to make the first distal cut of the femur during a total knee arthroplasty. In some embodiments, where the arthroplasty is a hip arthroplasty, cutting guide 105D can be fixed to the femoral head or the acetabulum for the respective hip arthroplasty resection. It should be understood that any arthroplasty that utilizes precise cuts can use the robotic arm 105A and/or cutting guide 105D in this manner.

The Resection Equipment 110 is provided with a variety of commands to perform bone or tissue operations. As with the Effector Platform 105, position information may be provided to the Resection Equipment 110 to specify where it should be located when performing resection. Other commands provided to the Resection Equipment 110 may be dependent on the type of resection equipment. For example, for a mechanical or ultrasonic resection tool, the commands may specify the speed and frequency of the tool. For Radiofrequency Ablation (RFA) and other laser ablation tools, the commands may specify intensity and pulse duration.

Some components of the CASS 100 do not need to be directly controlled by the Surgical Computer 150; rather, the Surgical Computer 150 only needs to activate the component, which then executes software locally specifying the manner in which to collect data and provide it to the Surgical Computer 150. In the example of FIG. 5A, there are two components that are operated in this manner: the Tracking System 115 and the Tissue Navigation System 120.

The Surgical Computer 150 provides the Display 125 with any visualization that is needed by the Surgeon 111 during surgery. For monitors, the Surgical Computer 150 may provide instructions for displaying images, GUIs, etc. using techniques known in the art. The display 125 can include various portions of the workflow of a surgical plan. During the registration process, for example, the display 125 can show a preoperatively constructed 3D bone model and depict the locations of the probe as the surgeon uses the probe to collect locations of anatomical landmarks on the patient. The display 125 can include information about the surgical target area. For example, in connection with a TKA, the display 125 can depict the mechanical and anatomical axes of the femur and tibia. The display 125 can depict varus and valgus angles for the knee joint based on a surgical plan, and the CASS 100 can depict how such angles will be affected if contemplated revisions to the surgical plan are made. Accordingly, the display 125 is an interactive interface that can dynamically update and display how changes to the surgical plan would impact the procedure and the final position and orientation of implants installed on bone.

As the workflow progresses to preparation of bone cuts or resections, the display 125 can depict the planned or recommended bone cuts before any cuts are performed. The surgeon 111 can manipulate the image display to provide different anatomical perspectives of the target area and can have the option to alter or revise the planned bone cuts based on intraoperative evaluation of the patient. The display 125 can depict how the chosen implants would be installed on the bone if the planned bone cuts are performed. If the surgeon 111 choses to change the previously planned bone cuts, the display 125 can depict how the revised bone cuts would change the position and orientation of the implant when installed on the bone.

The display 125 can provide the surgeon 111 with a variety of data and information about the patient, the planned surgical intervention, and the implants. Various patient-specific information can be displayed, including real-time data concerning the patient's health such as heart rate, blood pressure, etc. The display 125 also can include information about the anatomy of the surgical target region including the location of landmarks, the current state of the anatomy (e.g., whether any resections have been made, the depth and angles of planned and executed bone cuts), and future states of the anatomy as the surgical plan progresses. The display 125 also can provide or depict additional information about the surgical target region. For a TKA, the display 125 can provide information about the gaps (e.g., gap balancing) between the femur and tibia and how such gaps will change if the planned surgical plan is carried out. For a TKA, the display 125 can provide additional relevant information about the knee joint such as data about the joint's tension (e.g., ligament laxity) and information concerning rotation and alignment of the joint. The display 125 can depict how the planned implants' locations and positions will affect the patient as the knee joint is flexed. The display 125 can depict how the use of different implants or the use of different sizes of the same implant will affect the surgical plan and preview how such implants will be positioned on the bone. The CASS 100 can provide such information for each of the planned bone resections in a TKA or THA. In a TKA, the CASS 100 can provide robotic control for one or more of the planned bone resections. For example, the CASS 100 can provide robotic control only for the initial distal femur cut, and the surgeon 111 can manually perform other resections (anterior, posterior and chamfer cuts) using conventional means, such as a 4-in-1 cutting guide or jig 105D.

The display 125 can employ different colors to inform the surgeon of the status of the surgical plan. For example, un-resected bone can be displayed in a first color, resected bone can be displayed in a second color, and planned resections can be displayed in a third color. Implants can be superimposed onto the bone in the display 125, and implant colors can change or correspond to different types or sizes of implants.

The information and options depicted on the display 125 can vary depending on the type of surgical procedure being performed. Further, the surgeon 111 can request or select a particular surgical workflow display that matches or is consistent with his or her surgical plan preferences. For example, for a surgeon 111 who typically performs the tibial cuts before the femoral cuts in a TKA, the display 125 and associated workflow can be adapted to take this preference into account. The surgeon 111 also can preselect that certain steps be included or deleted from the standard surgical workflow display. For example, if a surgeon 111 uses resection measurements to finalize an implant plan but does not analyze ligament gap balancing when finalizing the implant plan, the surgical workflow display can be organized into modules, and the surgeon can select which modules to display and the order in which the modules are provided based on the surgeon's preferences or the circumstances of a particular surgery. Modules directed to ligament and gap balancing, for example, can include pre- and post-resection ligament/gap balancing, and the surgeon 111 can select which modules to include in their default surgical plan workflow depending on whether they perform such ligament and gap balancing before or after (or both) bone resections are performed.

For more specialized display equipment, such as AR HMDs, the Surgical Computer 150 may provide images, text, etc. using the data format supported by the equipment. For example, if the Display 125 is a holography device such as the Microsoft HoloLens™ or Magic Leap One™, the Surgical Computer 150 may use the HoloLens Application Program Interface (API) to send commands specifying the position and content of holograms displayed in the field of view of the Surgeon 111.

In some embodiments, one or more surgical planning models may be incorporated into the CASS 100 and used in the development of the surgical plans provided to the surgeon 111. The term “surgical planning model” refers to software that simulates the biomechanics performance of anatomy under various scenarios to determine the optimal way to perform cutting and other surgical activities. For example, for knee replacement surgeries, the surgical planning model can measure parameters for functional activities, such as deep knee bends, gait, etc., and select cut locations on the knee to optimize implant placement. One example of a surgical planning model is the LIFEMOD™ simulation software from SMITH AND NEPHEW, INC. In some embodiments, the Surgical Computer 150 includes computing architecture that allows full execution of the surgical planning model during surgery (e.g., a GPU-based parallel processing environment). In other embodiments, the Surgical Computer 150 may be connected over a network to a remote computer that allows such execution, such as a Surgical Data Server 180 (see FIG. 5C). As an alternative to full execution of the surgical planning model, in some embodiments, a set of transfer functions are derived that simplify the mathematical operations captured by the model into one or more predictor equations. Then, rather than execute the full simulation during surgery, the predictor equations are used. Further details on the use of transfer functions are described in WIPO Publication No. 2020/037308, filed Aug. 19, 2019, entitled “Patient Specific Surgical Method and System,” the entirety of which is incorporated herein by reference.

FIG. 5B shows examples of some of the types of data that can be provided to the Surgical Computer 150 from the various components of the CASS 100. In some embodiments, the components may stream data to the Surgical Computer 150 in real-time or near real-time during surgery. In other embodiments, the components may queue data and send it to the Surgical Computer 150 at set intervals (e.g., every second). Data may be communicated using any format known in the art. Thus, in some embodiments, the components all transmit data to the Surgical Computer 150 in a common format. In other embodiments, each component may use a different data format, and the Surgical Computer 150 is configured with one or more software applications that enable translation of the data.

In general, the Surgical Computer 150 may serve as the central point where CASS data is collected. The exact content of the data will vary depending on the source. For example, each component of the Effector Platform 105 provides a measured position to the Surgical Computer 150. Thus, by comparing the measured position to a position originally specified by the Surgical Computer 150 (see FIG. 5B), the Surgical Computer can identify deviations that take place during surgery.

The Resection Equipment 110 can send various types of data to the Surgical Computer 150 depending on the type of equipment used. Example data types that may be sent include the measured torque, audio signatures, and measured displacement values. Similarly, the Tracking Technology 115 can provide different types of data depending on the tracking methodology employed. Example tracking data types include position values for tracked items (e.g., anatomy, tools, etc.), ultrasound images, and surface or landmark collection points or axes. The Tissue Navigation System 120 provides the Surgical Computer 150 with anatomic locations, shapes, etc. as the system operates.

Although the Display 125 generally is used for outputting data for presentation to the user, it may also provide data to the Surgical Computer 150. For example, for embodiments where a monitor is used as part of the Display 125, the Surgeon 111 may interact with a GUI to provide inputs which are sent to the Surgical Computer 150 for further processing. For AR applications, the measured position and displacement of the HMD may be sent to the Surgical Computer 150 so that it can update the presented view as needed.

During the post-operative phase of the episode of care, various types of data can be collected to quantify the overall improvement or deterioration in the patient's condition as a result of the surgery. The data can take the form of, for example, self-reported information reported by patients via questionnaires. For example, in the context of a knee replacement surgery, functional status can be measured with an Oxford Knee Score questionnaire, and the post-operative quality of life can be measured with a EQ5D-5L questionnaire. Other examples in the context of a hip replacement surgery may include the Oxford Hip Score, Harris Hip Score, and WOMAC (Western Ontario and McMaster Universities Osteoarthritis index). Such questionnaires can be administered, for example, by a healthcare professional directly in a clinical setting or using a mobile app that allows the patient to respond to questions directly. In some embodiments, the patient may be outfitted with one or more wearable devices that collect data relevant to the surgery. For example, following a knee surgery, the patient may be outfitted with a knee brace that includes sensors that monitor knee positioning, flexibility, etc. This information can be collected and transferred to the patient's mobile device for review by the surgeon to evaluate the outcome of the surgery and address any issues. In some embodiments, one or more cameras can capture and record the motion of a patient's body segments during specified activities postoperatively. This motion capture can be compared to a biomechanics model to better understand the functionality of the patient's joints and better predict progress in recovery and identify any possible revisions that may be needed.

The post-operative stage of the episode of care can continue over the entire life of a patient. For example, in some embodiments, the Surgical Computer 150 or other components comprising the CASS 100 can continue to receive and collect data relevant to a surgical procedure after the procedure has been performed. This data may include, for example, images, answers to questions, “normal” patient data (e.g., blood type, blood pressure, conditions, medications, etc.), biometric data (e.g., gait, etc.), and objective and subjective data about specific issues (e.g., knee or hip joint pain). This data may be explicitly provided to the Surgical Computer 150 or other CASS component by the patient or the patient's physician(s). Alternatively or additionally, the Surgical Computer 150 or other CASS component can monitor the patient's EMR and retrieve relevant information as it becomes available. This longitudinal view of the patient's recovery allows the Surgical Computer 150 or other CASS component to provide a more objective analysis of the patient's outcome to measure and track success or lack of success for a given procedure. For example, a condition experienced by a patient long after the surgical procedure can be linked back to the surgery through a regression analysis of various data items collected during the episode of care. This analysis can be further enhanced by performing the analysis on groups of patients that had similar procedures and/or have similar anatomies.

In some embodiments, data is collected at a central location to provide for easier analysis and use. Data can be manually collected from various CASS components in some instances. For example, a portable storage device (e.g., USB stick) can be attached to the Surgical Computer 150 into order to retrieve data collected during surgery. The data can then be transferred, for example, via a desktop computer to the centralized storage. Alternatively, in some embodiments, the Surgical Computer 150 is connected directly to the centralized storage via a Network 175 as shown in FIG. 5C.

FIG. 5C illustrates a “cloud-based” implementation in which the Surgical Computer 150 is connected to a Surgical Data Server 180 via a Network 175. This Network 175 may be, for example, a private intranet or the Internet. In addition to the data from the Surgical Computer 150, other sources can transfer relevant data to the Surgical Data Server 180. The example of FIG. 5C shows 3 additional data sources: the Patient 160, Healthcare Professional(s) 165, and an EMR Database 170. Thus, the Patient 160 can send pre-operative and post-operative data to the Surgical Data Server 180, for example, using a mobile app. The Healthcare Professional(s) 165 includes the surgeon and his or her staff as well as any other professionals working with Patient 160 (e.g., a personal physician, a rehabilitation specialist, etc.). It should also be noted that the EMR Database 170 may be used for both pre-operative and post-operative data. For example, assuming that the Patient 160 has given adequate permissions, the Surgical Data Server 180 may collect the EMR of the Patient pre-surgery. Then, the Surgical Data Server 180 may continue to monitor the EMR for any updates post-surgery.

At the Surgical Data Server 180, an Episode of Care Database 185 is used to store the various data collected over a patient's episode of care. The Episode of Care Database 185 may be implemented using any technique known in the art. For example, in some embodiments, a SQL-based database may be used where all of the various data items are structured in a manner that allows them to be readily incorporated in two SQL's collection of rows and columns. However, in other embodiments a No-SQL database may be employed to allow for unstructured data, while providing the ability to rapidly process and respond to queries. As is understood in the art, the term “No-SQL” is used to define a class of data stores that are non-relational in their design. Various types of No-SQL databases may generally be grouped according to their underlying data model. These groupings may include databases that use column-based data models (e.g., Cassandra), document-based data models (e.g., MongoDB), key-value based data models (e.g., Redis), and/or graph-based data models (e.g., Allego). Any type of No-SQL database may be used to implement the various embodiments described herein and, in some embodiments, the different types of databases may support the Episode of Care Database 185.

Data can be transferred between the various data sources and the Surgical Data Server 180 using any data format and transfer technique known in the art. It should be noted that the architecture shown in FIG. 5C allows transmission from the data source to the Surgical Data Server 180, as well as retrieval of data from the Surgical Data Server 180 by the data sources. For example, as explained in detail below, in some embodiments, the Surgical Computer 150 may use data from past surgeries, machine learning models, etc. to help guide the surgical procedure.

In some embodiments, the Surgical Computer 150 or the Surgical Data Server 180 may execute a de-identification process to ensure that data stored in the Episode of Care Database 185 meets Health Insurance Portability and Accountability Act (HIPAA) standards or other requirements mandated by law. HIPAA provides a list of certain identifiers that must be removed from data during de-identification. The aforementioned de-identification process can scan for these identifiers in data that is transferred to the Episode of Care Database 185 for storage. For example, in one embodiment, the Surgical Computer 150 executes the de-identification process just prior to initiating transfer of a particular data item or set of data items to the Surgical Data Server 180. In some embodiments, a unique identifier is assigned to data from a particular episode of care to allow for re-identification of the data if necessary.

Although FIGS. 5A-5C discuss data collection in the context of a single episode of care, it should be understood that the general concept can be extended to data collection from multiple episodes of care. For example, surgical data may be collected over an entire episode of care each time a surgery is performed with the CASS 100 and stored at the Surgical Computer 150 or at the Surgical Data Server 180. As explained in further detail below, a robust database of episode of care data allows the generation of optimized values, measurements, distances, or other parameters and other recommendations related to the surgical procedure. In some embodiments, the various datasets are indexed in the database or other storage medium in a manner that allows for rapid retrieval of relevant information during the surgical procedure. For example, in one embodiment, a patient-centric set of indices may be used so that data pertaining to a particular patient or a set of patients similar to a particular patient can be readily extracted. This concept can be similarly applied to surgeons, implant characteristics, CASS component versions, etc.

Further details of the management of episode of care data is described in U.S. Patent Application No. 62/783,858 filed Dec. 21, 2018 and entitled “Methods and Systems for Providing an Episode of Care,” the entirety of which is incorporated herein by reference.

Open Versus Closed Digital Ecosystems

In some embodiments, the CASS 100 is designed to operate as a self-contained or “closed” digital ecosystem. Each component of the CASS 100 is specifically designed to be used in the closed ecosystem, and data is generally not accessible to devices outside of the digital ecosystem. For example, in some embodiments, each component includes software or firmware that implements proprietary protocols for activities such as communication, storage, security, etc. The concept of a closed digital ecosystem may be desirable for a company that wants to control all components of the CASS 100 to ensure that certain compatibility, security, and reliability standards are met. For example, the CASS 100 can be designed such that a new component cannot be used with the CASS unless it is certified by the company.

In other embodiments, the CASS 100 is designed to operate as an “open” digital ecosystem. In these embodiments, components may be produced by a variety of different companies according to standards for activities, such as communication, storage, and security. Thus, by using these standards, any company can freely build an independent, compliant component of the CASS platform. Data may be transferred between components using publicly available application programming interfaces (APIs) and open, shareable data formats.

To illustrate one type of recommendation that may be performed with the CASS 100, a technique for optimizing surgical parameters is disclosed below. The term “optimization” in this context means selection of parameters that are optimal based on certain specified criteria. In an extreme case, optimization can refer to selecting optimal parameter(s) based on data from the entire episode of care, including any pre-operative data, the state of CASS data at a given point in time, and post-operative goals. Moreover, optimization may be performed using historical data, such as data generated during past surgeries involving, for example, the same surgeon, past patients with physical characteristics similar to the current patient, or the like.

The optimized parameters may depend on the portion of the patient's anatomy to be operated on. For example, for knee surgeries, the surgical parameters may include positioning information for the femoral and tibial component including, without limitation, rotational alignment (e.g., varus/valgus rotation, external rotation, flexion rotation for the femoral component, posterior slope of the tibial component), resection depths (e.g., varus knee, valgus knee), and implant type, size and position. The positioning information may further include surgical parameters for the combined implant, such as overall limb alignment, combined tibiofemoral hyperextension, and combined tibiofemoral resection. Additional examples of parameters that could be optimized for a given TKA femoral implant by the CASS 100 include the following:

Exemplary

Parameter
Reference
Recommendation (s)

Size
Posterior
The largest sized

implant that does not

overhang

medial/lateral bone

edges or overhang the

anterior femur.

A size that does not

result in overstuffing

the patella femoral

joint

Implant Position -
Medial/lateral cortical
Center the implant

Medial Lateral
bone edges
evenly between the

medial/lateral cortical

bone edges

Resection Depth -
Distal and posterior
6 mm of bone

Varus Knee
lateral

Resection Depth -
Distal and posterior
7 mm of bone

Valgus Knee
medial

Rotation -
Mechanical Axis
1° varus

Varus/Valgus

Rotation - External
Transepicondylar
1° external from the

Axis
transepicondylar axis

Rotation - Flexion
Mechanical Axis
3° flexed

Additional examples of parameters that could be optimized for a given TKA tibial implant by the CASS 100 include the following:

Exemplary

Parameter
Reference
Recommendation (s)

Size
Posterior
The largest sized

implant that does not

overhang the medial,

lateral, anterior, and

posterior tibial edges

Implant Position
Medial/lateral and
Center the implant

anterior/posterior
evenly between the

cortical bone edges
medial/lateral and

anterior/posterior

cortical bone edges

Resection Depth -
Lateral/Medial
4 mm of bone

Varus Knee

Resection Depth -
Lateral/Medial
5 mm of bone

Valgus Knee

Rotation -
Mechanical Axis
1° valgus

Varus/Valgus

Rotation - External
Tibial Anterior
1° external from the

Posterior Axis
tibial anterior paxis

Posterior Slope
Mechanical Axis
3° posterior slope

For hip surgeries, the surgical parameters may comprise femoral neck resection location and angle, cup inclination angle, cup anteversion angle, cup depth, femoral stem design, femoral stem size, fit of the femoral stem within the canal, femoral offset, leg length, and femoral version of the implant.

Shoulder parameters may include, without limitation, humeral resection depth/angle, humeral stem version, humeral offset, glenoid version and inclination, as well as reverse shoulder parameters such as humeral resection depth/angle, humeral stem version, Glenoid tilt/version, glenosphere orientation, glenosphere offset and offset direction.

Various conventional techniques exist for optimizing surgical parameters. However, these techniques are typically computationally intensive and, thus, parameters often need to be determined pre-operatively. As a result, the surgeon is limited in his or her ability to make modifications to optimized parameters based on issues that may arise during surgery. Moreover, conventional optimization techniques typically operate in a “black box” manner with little or no explanation regarding recommended parameter values. Thus, if the surgeon decides to deviate from a recommended parameter value, the surgeon typically does so without a full understanding of the effect of that deviation on the rest of the surgical workflow, or the impact of the deviation on the patient's post-surgery quality of life.

Operative Patient Care System

The general concepts of optimization may be extended to the entire episode of care using an Operative Patient Care System 620 that uses the surgical data, and other data from the Patient 605 and Healthcare Professionals 630 to optimize outcomes and patient satisfaction as depicted in FIG. 6.

Conventionally, pre-operative diagnosis, pre-operative surgical planning, intra-operative execution of a prescribed plan, and post-operative management of total joint arthroplasty are based on individual experience, published literature, and training knowledge bases of surgeons (ultimately, tribal knowledge of individual surgeons and their ‘network’ of peers and journal publications) and their native ability to make accurate intra-operative tactile discernment of “balance” and accurate manual execution of planar resections using guides and visual cues. This existing knowledge base and execution is limited with respect to the outcomes optimization offered to patients needing care. For example, limits exist with respect to accurately diagnosing a patient to the proper, least-invasive prescribed care; aligning dynamic patient, healthcare economic, and surgeon preferences with patient-desired outcomes; executing a surgical plan resulting in proper bone alignment and balance, etc.; and receiving data from disconnected sources having different biases that are difficult to reconcile into a holistic patient framework. Accordingly, a data-driven tool that more accurately models anatomical response and guides the surgical plan can improve the existing approach.

The Operative Patient Care System 620 is designed to utilize patient specific data, surgeon data, healthcare facility data, and historical outcome data to develop an algorithm that suggests or recommends an optimal overall treatment plan for the patient's entire episode of care (preoperative, operative, and postoperative) based on a desired clinical outcome. For example, in one embodiment, the Operative Patient Care System 620 tracks adherence to the suggested or recommended plan, and adapts the plan based on patient/care provider performance. Once the surgical treatment plan is complete, collected data is logged by the Operative Patient Care System 620 in a historical database. This database is accessible for future patients and the development of future treatment plans. In addition to utilizing statistical and mathematical models, simulation tools (e.g., LIFEMOD®) can be used to simulate outcomes, alignment, kinematics, etc. based on a preliminary or proposed surgical plan, and reconfigure the preliminary or proposed plan to achieve desired or optimal results according to a patient's profile or a surgeon's preferences. The Operative Patient Care System 620 ensures that each patient is receiving personalized surgical and rehabilitative care, thereby improving the chance of successful clinical outcomes and lessening the economic burden on the facility associated with near-term revision.

In some embodiments, the Operative Patient Care System 620 employs a data collecting and management method to provide a detailed surgical case plan with distinct steps that are monitored and/or executed using a CASS 100. The performance of the user(s) is calculated at the completion of each step and can be used to suggest changes to the subsequent steps of the case plan. Case plan generation relies on a series of input data that is stored on a local or cloud-storage database. Input data can be related to both the current patient undergoing treatment and historical data from patients who have received similar treatment(s).

A Patient 605 provides inputs such as Current Patient Data 610 and Historical Patient Data 615 to the Operative Patient Care System 620. Various methods generally known in the art may be used to gather such inputs from the Patient 605. For example, in some embodiments, the Patient 605 fills out a paper or digital survey that is parsed by the Operative Patient Care System 620 to extract patient data. In other embodiments, the Operative Patient Care System 620 may extract patient data from existing information sources, such as electronic medical records (EMRs), health history files, and payer/provider historical files. In still other embodiments, the Operative Patient Care System 620 may provide an application program interface (API) that allows the external data source to push data to the Operative Patient Care System. For example, the Patient 605 may have a mobile phone, wearable device, or other mobile device that collects data (e.g., heart rate, pain or discomfort levels, exercise or activity levels, or patient-submitted responses to the patient's adherence with any number of pre-operative plan criteria or conditions) and provides that data to the Operative Patient Care System 620. Similarly, the Patient 605 may have a digital application on his or her mobile or wearable device that enables data to be collected and transmitted to the Operative Patient Care System 620.

Current Patient Data 610 can include, but is not limited to, activity level, preexisting conditions, comorbidities, prehab performance, health and fitness level, pre-operative expectation level (relating to hospital, surgery, and recovery), a Metropolitan Statistical Area (MSA) driven score, genetic background, prior injuries (sports, trauma, etc.), previous joint arthroplasty, previous trauma procedures, previous sports medicine procedures, treatment of the contralateral joint or limb, gait or biomechanical information (back and ankle issues), levels of pain or discomfort, care infrastructure information (payer coverage type, home health care infrastructure level, etc.), and an indication of the expected ideal outcome of the procedure.

Historical Patient Data 615 can include, but is not limited to, activity level, preexisting conditions, comorbidities, prehab performance, health and fitness level, pre-operative expectation level (relating to hospital, surgery, and recovery), a MSA driven score, genetic background, prior injuries (sports, trauma, etc.), previous joint arthroplasty, previous trauma procedures, previous sports medicine procedures, treatment of the contralateral joint or limb, gait or biomechanical information (back and ankle issues), levels or pain or discomfort, care infrastructure information (payer coverage type, home health care infrastructure level, etc.), expected ideal outcome of the procedure, actual outcome of the procedure (patient reported outcomes [PROs], survivorship of implants, pain levels, activity levels, etc.), sizes of implants used, position/orientation/alignment of implants used, soft-tissue balance achieved, etc.

Healthcare Professional(s) 630 conducting the procedure or treatment may provide various types of data 625 to the Operative Patient Care System 620. This Healthcare Professional Data 625 may include, for example, a description of a known or preferred surgical technique (e.g., Cruciate Retaining (CR) vs Posterior Stabilized (PS), up- vs down-sizing, tourniquet vs tourniquet-less, femoral stem style, preferred approach for THA, etc.), the level of training of the Healthcare Professional(s) 630 (e.g., years in practice, fellowship trained, where they trained, whose techniques they emulate), previous success level including historical data (outcomes, patient satisfaction), and the expected ideal outcome with respect to range of motion, days of recovery, and survivorship of the device. The Healthcare Professional Data 625 can be captured, for example, with paper or digital surveys provided to the Healthcare Professional 630, via inputs to a mobile application by the Healthcare Professional, or by extracting relevant data from EMRs. In addition, the CASS 100 may provide data such as profile data (e.g., a Patient Specific Knee Instrument Profile) or historical logs describing use of the CASS during surgery.

Information pertaining to the facility where the procedure or treatment will be conducted may be included in the input data. This data can include, without limitation, the following: Ambulatory Surgery Center (ASC) vs hospital, facility trauma level, Comprehensive Care for Joint Replacement Program (CJR) or bundle candidacy, a MSA driven score, community vs metro, academic vs non-academic, postoperative network access (Skilled Nursing Facility [SNF] only, Home Health, etc.), availability of medical professionals, implant availability, and availability of surgical equipment.

These facility inputs can be captured by, for example and without limitation, Surveys (Paper/Digital), Surgery Scheduling Tools (e.g., apps, Websites, Electronic Medical Records [EMRs], etc.), Databases of Hospital Information (on the Internet), etc. Input data relating to the associated healthcare economy including, but not limited to, the socioeconomic profile of the patient, the expected level of reimbursement the patient will receive, and if the treatment is patient specific may also be captured.

These healthcare economic inputs can be captured by, for example and without limitation, Surveys (Paper/Digital), Direct Payer Information, Databases of Socioeconomic status (on the Internet with zip code), etc. Finally, data derived from simulation of the procedure is captured. Simulation inputs include implant size, position, and orientation. Simulation can be conducted with custom or commercially available anatomical modeling software programs (e.g., LIFEMOD®, AnyBody, or OpenSIM). It is noted that the data inputs described above may not be available for every patient, and the treatment plan will be generated using the data that is available.

Prior to surgery, the Patient Data 610, 615 and Healthcare Professional Data 625 may be captured and stored in a cloud-based or online database (e.g., the Surgical Data Server 180 shown in FIG. 5C). Information relevant to the procedure is supplied to a computing system via wireless data transfer or manually with the use of portable media storage. The computing system is configured to generate a case plan for use with a CASS 100. Case plan generation will be described hereinafter. It is noted that the system has access to historical data from previous patients undergoing treatment, including implant size, placement, and orientation as generated by a computer-assisted, patient-specific knee instrument (PSKI) selection system, or automatically by the CASS 100 itself. To achieve this, case log data is uploaded to the historical database by a surgical sales rep or case engineer using an online portal. In some embodiments, data transfer to the online database is wireless and automated.

Historical data sets from the online database are used as inputs to a machine learning model such as, for example, a recurrent neural network (RNN) or other form of artificial neural network. As is generally understood in the art, an artificial neural network functions similar to a biologic neural network and is comprised of a series of nodes and connections. The machine learning model is trained to predict one or more values based on the input data. For the sections that follow, it is assumed that the machine learning model is trained to generate predictor equations. These predictor equations may be optimized to determine the optimal size, position, and orientation of the implants to achieve the best outcome or satisfaction level.

Once the procedure is complete, all patient data and available outcome data, including the implant size, position and orientation determined by the CASS 100, are collected and stored in the historical database. Any subsequent calculation of the target equation via the RNN will include the data from the previous patient in this manner, allowing for continuous improvement of the system.

In addition to, or as an alternative to determining implant positioning, in some embodiments, the predictor equation and associated optimization can be used to generate the resection planes for use with a PSKI system. When used with a PSKI system, the predictor equation computation and optimization are completed prior to surgery. Patient anatomy is estimated using medical image data (x-ray, CT, MRI). Global optimization of the predictor equation can provide an ideal size and position of the implant components. Boolean intersection of the implant components and patient anatomy is defined as the resection volume. PSKI can be produced to remove the optimized resection envelope. In this embodiment, the surgeon cannot alter the surgical plan intraoperatively.

The surgeon may choose to alter the surgical case plan at any time prior to or during the procedure. If the surgeon elects to deviate from the surgical case plan, the altered size, position, and/or orientation of the component(s) is locked, and the global optimization is refreshed based on the new size, position, and/or orientation of the component(s) (using the techniques previously described) to find the new ideal position of the other component(s) and the corresponding resections needed to be performed to achieve the newly optimized size, position and/or orientation of the component(s). For example, if the surgeon determines that the size, position and/or orientation of the femoral implant in a TKA needs to be updated or modified intraoperatively, the femoral implant position is locked relative to the anatomy, and the new optimal position of the tibia will be calculated (via global optimization) considering the surgeon's changes to the femoral implant size, position and/or orientation. Furthermore, if the surgical system used to implement the case plan is robotically assisted (e.g., as with NAVIO® or the MAKO Rio), bone removal and bone morphology during the surgery can be monitored in real time. If the resections made during the procedure deviate from the surgical plan, the subsequent placement of additional components may be optimized by the processor taking into account the actual resections that have already been made.

FIG. 7A illustrates how the Operative Patient Care System 620 may be adapted for performing case plan matching services. In this example, data is captured relating to the current patient 610 and is compared to all or portions of a historical database of patient data and associated outcomes 615. For example, the surgeon may elect to compare the plan for the current patient against a subset of the historical database. Data in the historical database can be filtered to include, for example, only data sets with favorable outcomes, data sets corresponding to historical surgeries of patients with profiles that are the same or similar to the current patient profile, data sets corresponding to a particular surgeon, data sets corresponding to a particular element of the surgical plan (e.g., only surgeries where a particular ligament is retained), or any other criteria selected by the surgeon or medical professional. If, for example, the current patient data matches or is correlated with that of a previous patient who experienced a good outcome, the case plan from the previous patient can be accessed and adapted or adopted for use with the current patient. The predictor equation may be used in conjunction with an intra-operative algorithm that identifies or determines the actions associated with the case plan. Based on the relevant and/or preselected information from the historical database, the intra-operative algorithm determines a series of recommended actions for the surgeon to perform. Each execution of the algorithm produces the next action in the case plan. If the surgeon performs the action, the results are evaluated. The results of the surgeon's performing the action are used to refine and update inputs to the intra-operative algorithm for generating the next step in the case plan. Once the case plan has been fully executed all data associated with the case plan, including any deviations performed from the recommended actions by the surgeon, are stored in the database of historical data. In some embodiments, the system utilizes preoperative, intraoperative, or postoperative modules in a piecewise fashion, as opposed to the entire continuum of care. In other words, caregivers can prescribe any permutation or combination of treatment modules including the use of a single module. These concepts are illustrated in FIG. 7B and can be applied to any type of surgery utilizing the CASS 100.

Surgery Process Display

As noted above with respect to FIGS. 1 and 5A-5C, the various components of the CASS 100 generate detailed data records during surgery. The CASS 100 can track and record various actions and activities of the surgeon during each step of the surgery and compare actual activity to the pre-operative or intraoperative surgical plan. In some embodiments, a software tool may be employed to process this data into a format where the surgery can be effectively “played-back.” For example, in one embodiment, one or more GUIs may be used that depict all of the information presented on the Display 125 during surgery. This can be supplemented with graphs and images that depict the data collected by different tools. For example, a GUI that provides a visual depiction of the knee during tissue resection may provide the measured torque and displacement of the resection equipment adjacent to the visual depiction to better provide an understanding of any deviations that occurred from the planned resection area. The ability to review a playback of the surgical plan or toggle between different phases of the actual surgery vs. the surgical plan could provide benefits to the surgeon and/or surgical staff, allowing such persons to identify any deficiencies or challenging phases of a surgery so that they can be modified in future surgeries. Similarly, in academic settings, the aforementioned GUIs can be used as a teaching tool for training future surgeons and/or surgical staff. Additionally, because the data set effectively records many elements of the surgeon's activity, it may also be used for other reasons (e.g., legal or compliance reasons) as evidence of correct or incorrect performance of a particular surgical procedure.

Over time, as more and more surgical data is collected, a rich library of data may be acquired that describes surgical procedures performed for various types of anatomy (knee, shoulder, hip, etc.) by different surgeons for different patients. Moreover, information such as implant type and dimension, patient demographics, etc. can further be used to enhance the overall dataset. Once the dataset has been established, it may be used to train a machine learning model (e.g., RNN) to make predictions of how surgery will proceed based on the current state of the CASS 100.

Training of the machine learning model can be performed as follows. The overall state of the CASS 100 can be sampled over a plurality of time periods for the duration of the surgery. The machine learning model can then be trained to translate a current state at a first time period to a future state at a different time period. By analyzing the entire state of the CASS 100 rather than the individual data items, any causal effects of interactions between different components of the CASS 100 can be captured. In some embodiments, a plurality of machine learning models may be used rather than a single model. In some embodiments, the machine learning model may be trained not only with the state of the CASS 100, but also with patient data (e.g., captured from an EMR) and an identification of members of the surgical staff. This allows the model to make predictions with even greater specificity. Moreover, it allows surgeons to selectively make predictions based only on their own surgical experiences if desired.

In some embodiments, predictions or recommendations made by the aforementioned machine learning models can be directly integrated into the surgical workflow. For example, in some embodiments, the Surgical Computer 150 may execute the machine learning model in the background making predictions or recommendations for upcoming actions or surgical conditions. A plurality of states can thus be predicted or recommended for each period. For example, the Surgical Computer 150 may predict or recommend the state for the next 5 minutes in 30 second increments. Using this information, the surgeon can utilize a “process display” view of the surgery that allows visualization of the future state. For example, FIG. 7C depicts a series of images that may be displayed to the surgeon depicting the implant placement interface. The surgeon can cycle through these images, for example, by entering a particular time into the display 125 of the CASS 100 or instructing the system to advance or rewind the display in a specific time increment using a tactile, oral, or other instruction. In one embodiment, the process display can be presented in the upper portion of the surgeon's field of view in the AR HMD. In some embodiments, the process display can be updated in real-time. For example, as the surgeon moves resection tools around the planned resection area, the process display can be updated so that the surgeon can see how his or her actions are affecting the other factors of the surgery.

In some embodiments, rather than simply using the current state of the CASS 100 as an input to the machine learning model, the inputs to the model may include a planned future state. For example, the surgeon may indicate that he or she is planning to make a particular bone resection of the knee joint. This indication may be entered manually into the Surgical Computer 150 or the surgeon may verbally provide the indication. The Surgical Computer 150 can then produce a film strip showing the predicted effect of the cut on the surgery. Such a film strip can depict over specific time increments how the surgery will be affected, including, for example, changes in the patient's anatomy, changes to implant position and orientation, and changes regarding surgical intervention and instrumentation, if the contemplated course of action were to be performed. A surgeon or medical professional can invoke or request this type of film strip at any point in the surgery to preview how a contemplated course of action would affect the surgical plan if the contemplated action were to be carried out.

It should be further noted that, with a sufficiently trained machine learning model and robotic CASS, various elements of the surgery can be automated such that the surgeon only needs to be minimally involved, for example, by only providing approval for various steps of the surgery. For example, robotic control using arms or other means can be gradually integrated into the surgical workflow over time with the surgeon slowly becoming less and less involved with manual interaction versus robot operation. The machine learning model in this case can learn what robotic commands are required to achieve certain states of the CASS-implemented plan. Eventually, the machine learning model may be used to produce a film strip or similar view or display that predicts and can preview the entire surgery from an initial state. For example, an initial state may be defined that includes the patient information, the surgical plan, implant characteristics, and surgeon preferences. Based on this information, the surgeon could preview an entire surgery to confirm that the CASS-recommended plan meets the surgeon's expectations and/or requirements. Moreover, because the output of the machine learning model is the state of the CASS 100 itself, commands can be derived to control the components of the CASS to achieve each predicted state. In the extreme case, the entire surgery could thus be automated based on just the initial state information.

Using the Point Probe to Acquire High-Resolution of Key Areas During Hip Surgeries

Use of the point probe is described in U.S. patent application Ser. No. 14/955,742 entitled “Systems and Methods for Planning and Performing Image Free Implant Revision Surgery,” the entirety of which is incorporated herein by reference. Briefly, an optically tracked point probe may be used to map the actual surface of the target bone that needs a new implant. Mapping is performed after removal of the defective or worn-out implant, as well as after removal of any diseased or otherwise unwanted bone. A plurality of points is collected on the bone surfaces by brushing or scraping the entirety of the remaining bone with the tip of the point probe. This is referred to as tracing or “painting” the bone. The collected points are used to create a three-dimensional model or surface map of the bone surfaces in the computerized planning system. The created 3D model of the remaining bone is then used as the basis for planning the procedure and necessary implant sizes. An alternative technique that uses X-rays to determine a 3D model is described in U.S. patent application Ser. No. 16/387,151, filed Apr. 17, 2019 and entitled “Three-Dimensional Selective Bone Matching” and U.S. patent application Ser. No. 16/789,930, filed Feb. 13, 2020 and entitled “Three-Dimensional Selective Bone Matching,” the entirety of each of which is incorporated herein by reference.

For hip applications, the point probe painting can be used to acquire high resolution data in key areas such as the acetabular rim and acetabular fossa. This can allow a surgeon to obtain a detailed view before beginning to ream. For example, in one embodiment, the point probe may be used to identify the floor (fossa) of the acetabulum. As is well understood in the art, in hip surgeries, it is important to ensure that the floor of the acetabulum is not compromised during reaming so as to avoid destruction of the medial wall. If the medial wall were inadvertently destroyed, the surgery would require the additional step of bone grafting. With this in mind, the information from the point probe can be used to provide operating guidelines to the acetabular reamer during surgical procedures. For example, the acetabular reamer may be configured to provide haptic feedback to the surgeon when he or she reaches the floor or otherwise deviates from the surgical plan. Alternatively, the CASS 100 may automatically stop the reamer when the floor is reached or when the reamer is within a threshold distance.

As an additional safeguard, the thickness of the area between the acetabulum and the medial wall could be estimated. For example, once the acetabular rim and acetabular fossa has been painted and registered to the pre-operative 3D model, the thickness can readily be estimated by comparing the location of the surface of the acetabulum to the location of the medial wall. Using this knowledge, the CASS 100 may provide alerts or other responses in the event that any surgical activity is predicted to protrude through the acetabular wall while reaming.

The point probe may also be used to collect high resolution data of common reference points used in orienting the 3D model to the patient. For example, for pelvic plane landmarks like the ASIS and the pubic symphysis, the surgeon may use the point probe to paint the bone to represent a true pelvic plane. Given a more complete view of these landmarks, the registration software has more information to orient the 3D model.

The point probe may also be used to collect high-resolution data describing the proximal femoral reference point that could be used to increase the accuracy of implant placement. For example, the relationship between the tip of the Greater Trochanter (GT) and the center of the femoral head is commonly used as reference point to align the femoral component during hip arthroplasty. The alignment is highly dependent on proper location of the GT; thus, in some embodiments, the point probe is used to paint the GT to provide a high-resolution view of the area. Similarly, in some embodiments, it may be useful to have a high-resolution view of the Lesser Trochanter (LT). For example, during hip arthroplasty, the Dorr Classification helps to select a stem that will maximize the ability of achieving a press-fit during surgery to prevent micromotion of femoral components post-surgery and ensure optimal bony ingrowth. As is generated understood in the art, the Dorr Classification measures the ratio between the canal width at the LT and the canal width 10 cm below the LT. The accuracy of the classification is highly dependent on the correct location of the relevant anatomy. Thus, it may be advantageous to paint the LT to provide a high-resolution view of the area.

In some embodiments, the point probe is used to paint the femoral neck to provide high-resolution data that allows the surgeon to better understand where to make the neck cut. The navigation system can then guide the surgeon as they perform the neck cut. For example, as understood in the art, the femoral neck angle is measured by placing one line down the center of the femoral shaft and a second line down the center of the femoral neck. Thus, a high-resolution view of the femoral neck (and possibly the femoral shaft as well) would provide a more accurate calculation of the femoral neck angle.

High-resolution femoral head neck data also could be used for a navigated resurfacing procedure where the software/hardware aids the surgeon in preparing the proximal femur and placing the femoral component. As is generally understood in the art, during hip resurfacing, the femoral head and neck are not removed; rather, the head is trimmed and capped with a smooth metal covering. In this case, it would be advantageous for the surgeon to paint the femoral head and cap so that an accurate assessment of their respective geometries can be understood and used to guide trimming and placement of the femoral component.

Registration of Pre-Operative Data to Patient Anatomy Using the Point Probe

As noted above, in some embodiments, a 3D model is developed during the pre-operative stage based on 2D or 3D images of the anatomical area of interest. In such embodiments, registration between the 3D model and the surgical site is performed prior to the surgical procedure. The registered 3D model may be used to track and measure the patient's anatomy and surgical tools intraoperatively.

During the surgical procedure, landmarks are acquired to facilitate registration of this pre-operative 3D model to the patient's anatomy. For knee procedures, these points could comprise the femoral head center, distal femoral axis point, medial and lateral epicondyles, medial and lateral malleolus, proximal tibial mechanical axis point, and tibial A/P direction. For hip procedures these points could comprise the anterior superior iliac spine (ASIS), the pubic symphysis, points along the acetabular rim and within the hemisphere, the greater trochanter (GT), and the lesser trochanter (LT).

In a revision surgery, the surgeon may paint certain areas that contain anatomical defects to allow for better visualization and navigation of implant insertion. These defects can be identified based on analysis of the pre-operative images. For example, in one embodiment, each pre-operative image is compared to a library of images showing “healthy” anatomy (i.e., without defects). Any significant deviations between the patient's images and the healthy images can be flagged as a potential defect. Then, during surgery, the surgeon can be warned of the possible defect via a visual alert on the display 125 of the CASS 100. The surgeon can then paint the area to provide further detail regarding the potential defect to the Surgical Computer 150.

In some embodiments, the surgeon may use a non-contact method for registration of bony anatomy intra-incision. For example, in one embodiment, laser scanning is employed for registration. A laser stripe is projected over the anatomical area of interest and the height variations of the area are detected as changes in the line. Other non-contact optical methods, such as white light interferometry or ultrasound, may alternatively be used for surface height measurement or to register the anatomy. For example, ultrasound technology may be beneficial where there is soft tissue between the registration point and the bone being registered (e.g., ASIS, pubic symphysis in hip surgeries), thereby providing for a more accurate definition of anatomic planes.

Tensioner Tool with Digital Force and Displacement Sensing

As discussed herein, certain surgeries, such as joint reconstruction procedures, often utilize tensioner tools to apply a force to the surface of a bone of the joint in order to assess the joint tension/laxity. As generally described herein, application of a force to the surface of the bone of the joint results in a force applied to the joint, which may cause a distraction of the joint. A surgeon may prefer to perform the assessment at multiple points along the range of motion of the joint. Ideally, the distraction force and distraction distance may be measured and the assessment can be performed pre-operatively as well as intraoperatively. In some cases, data from the application of a plurality of discrete quantities of force and/or application of force at a plurality of locations may assist in providing a more complete assessment.

Referring now to FIGS. 8A-8E, several views of an example embodiment of a tensioner tool are illustrated. The tensioner tool 800 may further be incorporated as part of a CASS (e.g., CASS 100 shown in FIG. 1). The tensioner tool 800 comprises a first arm 805A and a second arm 805B coupled by a pivot 820 located along the length of the arms 805. The first arm 805A comprises a handle portion 810A at the proximal end and an insertion tip 815A at the distal end. Similarly, the second arm 805B comprises a handle portion 810B at the proximal end and an insertion tip 815B at the distal end. As shown in FIG. 8A, the pivot 820 that joins the arms 805A-B is located between the handle portion 810A-B and the insertion tip 815A-B on each respective arm. In order to form the pivot 820, each arm may include a hole extending orthogonal to the longitudinal axis of the arm. The holes are aligned and a pivot pin is placed therethrough (most clearly shown in FIGS. 8B and 8D), thus coupling the arms 805A-B while permitting pivotal movement about the pivot pin.

The tensioner tool 800 may be moved between a closed configuration and an open configuration by pivotal movement of the arms 805A-B about the pivot 820. The pivot 820 is configured to allow manual separation of the insertion tips 815A-B by applying force to the handle portions 810A-B of the arms 805A-B. In the closed configuration, the insertion tips 815A-B are relatively proximate to another. For example, as depicted in FIGS. 8A-8B and 8E, the arms 805A-B are positioned such that the insertion tips 815A-B abut one another. In some embodiments, the insertion tips 815A-B may be spaced apart (i.e., separated by a non-zero distance) even in the closed configuration. In the open configuration, the insertion tips 815A-B are relatively spaced from one another (i.e., separated by a greater distance than in the closed configuration). For example, as demonstrated in FIG. 8C, the arms 805A-B may be pivoted about the pivot 820 to separate the insertion tips 815A-B. Applying a force to the handle portions 810A-B may result in the arms 805A-B pivoting to switch the tensioner tool 800 from the closed configuration to the open configuration.

As shown in FIG. 8B, in an embodiment the tensioner tool 800 comprises one or more force sensors 825 located upon the handle portion 810A of the first arm 805A to measure the force applied to the handle portion 810A. The one or more force sensors 825 are located proximally of the pivot 820. For example, as shown in FIG. 8B, the force sensor 825 may be adjacent to the pivot 820. In some embodiments, the force sensor 825 may be further spaced from the pivot 820. In some embodiments, the force sensor 825 may be placed in additional or alternative locations upon one or more of the arms 805A-B, e.g., the handle portions 810A-B or on a portion of the arms 805A-B distal of the pivot 820. In some embodiments, the tensioner tool 800 includes an array of force sensors 825 to measure the applied force. In such embodiments, several measured forces may be averaged to provide a more accurate force value. Additional locations and arrangements of force sensors 825 will be apparent to one having an ordinary level of skill in the art.

In some embodiments, the one or more force sensors 825 comprise one or more strain gauges. In some embodiments, the one or more strain gauges may have a Wheatstone bridge configuration. However, other types of force sensors 825 could alternatively or additionally be utilized. For example, the one or more force sensors 825 may include any type of pressure sensors, piezoresistive sensors, torque sensors, or load sensors. Other sensors capable of being used with the tensioner tool 800 will be apparent to one having an ordinary level of skill in the art. Additional locations and/or arrangements of force sensors 825 may also be provided. In some embodiments, an array of force sensors 825 may be utilized. In some embodiments, the force sensor 825 or array of force sensors may be positioned on one or both of the insertion tips 815A-B. For example, one or more force sensors 825 may be integrally formed on the contact surface of an insertion tip 815 or provided on a thin, flexible, substantially planar substrate (e.g., a film) affixed to the contact surface by embedding, adhering, heat-sealing, or any other method known to one having ordinary skill in the art. The array of force sensors 825 may be configured to entirely or substantially cover the contact surface of the insertion tip 815 which will contact and apply force to a surface of one or more bones of the joint. In other words, the array of force sensors 825 may be shaped and sized based on the insertion tip 815A-B so as to cover a footprint of the insertion tip or a contacting portion of the footprint.

In some embodiments, a force sensor 825 may be located upon one of the arms, such as 805A, and the arm may include one or more concentration features configured to concentrate stress forces at the location of the force sensor 825. For example, the one or more concentration features may include holes, grooves, notches, fillets, or other irregularities in the design of the arm that concentrates the stress forces resulting from a force applied at the handle portion 810A.

Referring again to FIG. 8B, the tensioner tool 800 may comprise one or more positional sensors 830 located upon at least one of the arms 805A with a known spatial relationship with respect to the insertion tips 815A-B. The one or more positional sensors 830 are configured to measure a separation between the arm 805A in order to facilitate calculation of a tip distance between the insertion tips 815A-B (i.e., a distraction distance during distraction of a joint). In some embodiments, force measurements from the force sensors may additionally be utilized in the distraction distance calculations (e.g., as a calibration factor). In some embodiments, where high loads are applied, the tensioner tool 800 may experience bending at various locations, thus affecting the geometry of the tensioner tool 800 in a manner that affects the relationship of the separation measured by the positional sensors 830 to distraction distance. As such, the force measurements may be utilized to estimate any deformation of the tensioner tool 800 and account for the deformation in the distraction distance calculations. Additionally, the one or more positional sensors 830 may be located anywhere along the arms 805A-B. As shown in FIG. 8B, in some embodiments a positional sensor 830 may be adjacent to the pivot 820. In some embodiments, a positional sensor 830 may be spaced further from the pivot 820. In some embodiments, one or more positional sensors 830 may be placed in additional or alternative locations upon the arms 805A-B, e.g., the handle portions 810A-B or on a portion of the arms distal from the pivot 820. In some embodiments, the one or more positional sensors 830 may be embedded in or otherwise coupled to the insertion tips 815A-B. In some embodiments, the tensioner tool 800 includes an array of positional sensors 830 to measure a separation between the arms 805A-B at multiple locations with known spatial relationships with the insertions tips 815A-B. In such embodiments, several measured separation distances may be utilized to more accurately calculate the distraction distance. Additional locations and arrangements of positional sensors 830 will be apparent to one having an ordinary level of skill in the art.

In some embodiments, the one or more positional sensors 830 comprise one or more Hall effect sensors. The Hall effect sensors may be positioned on an inner face of one of the arms 805A-B in order to measure a separation of the arms. As shown in FIG. 8B, a magnet 835 may be attached or embedded to the arm 805B opposing the Hall effect sensor 830 such that the magnitude of an emitted magnetic field as measured by the Hall effect sensor 830 correlates to a separation distance of the arms 805. In some embodiments, the magnet 835 may be positioned on the second arm 805B at a position along the longitudinal axis of the second arm matching a position of the Hall effect sensor 830 on the first arm 805A such that the magnet 835 directly opposes the Hall effect sensor. In some embodiments, the magnet 835 may be offset from a position along the longitudinal axis of the second arm 805B that matches the position of the Hall effect sensor 830 on the first arm 805A. In some embodiments, the Hall effect sensor 830 is located on the second arm 805B, and the magnet 835 is located on the first arm 805A. In some embodiments, the position of the magnet 835 with respect to the Hall effect sensor 830 is fixed such that the positional relationship is known (i.e., in the closed configuration, the magnet 835 is positioned at a known distance from the Hall effect sensor 830). In some embodiments, the magnet 835 is removable and/or adjustable in position. In such cases, the positional relationship of the magnet 835 to the Hall effect sensor 830 is determined by a computing device or provided thereto by input, calibration, sensing, or other methods known to one having an ordinary level of skill in the art. Other types of positional sensors 830 could alternatively or additionally be utilized. In some embodiments, the one or more positional sensors 830 may include a potentiometer, an encoder, and/or a proximity sensor located along the length of one of the arms 805A-B. In some embodiments, the one or more positional sensors 830 may be positioned on an inner face of one of the arms 805A-B in order to face the opposing arm 805A-B to measure a separation therebetween. However, additional configurations of positional sensors 830 may be utilized as would be known to one having an ordinary level of skill in the art. In some embodiments, the one or more position sensors 830 may include other types of sensors with appropriate arrangements and modifications as would be apparent based on the teachings herein.

Referring once again to FIG. 8B, the tensioner tool 800 may comprise sensing electronics 840, which include additional electronic components needed to capture the force data and separation data from the one or more force sensors 825 and the one or more positional sensors 830. In some embodiments, the sensing electronics 840 include a processor. The processor may receive force data including applied force measurements from the one or more force sensors 825 and separation data including separation distance measurements from the one or more positional sensors 830. In some embodiments, the processor utilizes the force data and the separation data to perform calculations. In some embodiments, the sensing electronics 840 can include a highly integrated microcontroller device with a variety of on-board hardware functions, such as signal amplifiers, analog to digital converters, digital to analog converters, serial buses, general purpose I/O pins, RAM, and ROM, or configurable hardware logic configured to process the force data and separation data. As shown in FIG. 8B, some or all of the sensing electronics may be housed on a printed circuit board (PCB). In this example, the sensing electronics 840 may be coupled to a display interface located on one of the handles, such as 810A, or elsewhere on the tensioner tool 800 to display information derived from the force data and the separation data (e.g., distraction force and distraction distance), such that the tensioner tool 800 can act as a standalone device. Examples of the calculations that may be performed by the processor and information that may be displayed on the display interface of the tensioner tool are described in greater detail with respect to the system of FIG. 11.

In some embodiments, the tensioner tool 800 may additionally or alternatively include communication electronics (not shown) configured to transmit the signals to an external computing device (e.g. the surgical computer 150 of the CASS 100) to perform calculations as described herein. For example, the tensioner tool 800 may comprise a communication interface such as a port or adapter that may be mated with a complementary interfacing component of the external computing device. In some embodiments, the communication interface is a USB port configured to provide wired connection to the surgical computer 150, although other communication protocols using other types and/or numbers of communication interfaces can be employed. In additional embodiments, the communication interface may comprise a wireless transmission system such that the electronic communication with the external computing device is wireless. The communication interface may comprise one or more standard wireless communication protocols, including but not limited to Bluetooth, WiFi, Zigbee, or broadband cellular network communication. The communication interface is coupled to the sensing electronics 840 by a bus or other communication link to receive the data from the one or more sensors 825/830. In this example, the communication interface operatively couples and communicates between the sensing electronics 840 of the tensioner tool and other computing devices. The force data and the separation data may be sent via the communication interface for remote processing.

In some embodiments, the tensioner tool 800 comprises a power source. For example, an on-board power source such as a battery may be included in communication with the sensing electronics 840. In some embodiments, the tensioner tool 800 comprises a power interface such as a port or adapter that may be mated with a complementary interfacing component of an external power source in order to provide power to the tensioner tool 800. In some embodiments, the power interface is a USB port configured to provide wired connection to a power source, although other types and/or numbers of power interfaces can be employed. In some embodiments, a single interface may be utilized as a communication interface and a power interface. For example, a USB port may provide wired connection to an external computing device, which provides power to and receives signals from the tensioner tool 800.

In some embodiments, the tensioner tool 800 may include one or more buttons or other means of controlling the function of the processor, display, and sensing electronics. In some embodiments, the tensioner tool 800 comprises a power button for turning the electronic components of the tool on and off. In some embodiments, the tensioner tool 800 comprises a display button to alter the display readout. For example, the display button may be pressed one or more times to cycle through different display options. In some embodiments, the display button may cycle through different output units in which the calculated measurements are displayed. In some embodiments, the display button may cycle through different parameters or measurements to be displayed. In some embodiments, the tensioner tool 800 comprises a calibration button such as a “zero out” or “tare” button in order to reset the measurements to zero to account for and cancel out any existing force and/or separation sensed by the tensioner tool 800. In some embodiments, this feature may be utilized to account for any “noise” being sensed by the sensors. In some embodiments, this feature may be utilized to display a differential reading between two measurements.

Referring now to FIG. 8D, the insertion tips 815A-B are described in greater detail. In some embodiments, the insertion tips 815A-B extend from the distal ends of the arms 805A-B in a direction parallel to the rotational axis of the pivot 820 so as to be “side-facing” tips as shown. The distal portions of the insertion tips 815A-B form a contact surface for interfacing with the bones of the patient. As shown in FIG. 8D, the insertion tips 815A-B may taper distally, forming a slim profile and a minimal thickness at the free end. In some embodiments, the insertion tips 815A-B may be distinct from one another in their shape and design. For example, insertion tip 815A may have a two-pronged design adapted to engage and lift the femur during distraction, while insertion tip 815B may have a one-pronged design. The two-pronged design for engaging the femur may allow the insertion tip 815A to cradle a condyle of the femur and self-center upon the condyle by sliding along the surface of the condyle as the insertion tip is placed and/or retracted. Accordingly, tensioning across a plurality of measurements may be performed with at more consistent location. Further, the insertion tips 815A-B may be configured to nest together to further minimize the effective thickness of the tensioner tool 800 at the point of insertion. As most clearly shown in FIGS. 8B and 8D, the underside of insertion tip 815A may be configured to mate and nest with insertion tip 815B to align the free ends. Insertion tip 815A may also have a curved shape such that the free ends are substantially aligned in the same plane in the closed configuration as shown in FIG. 8B, thereby minimizing the effective thickness at the free end. The slim, tapering profile facilitates insertion of the tensioner tool 800 into the limited space between the bones of a joint, especially in the pre-operative stages prior to performing bone resections.

In some embodiments, the insertion tips 815A-B may be configured to grip the bone surfaces in order to mitigate shifting of the tensioner tool 800 during tensioning. For example, as shown in FIG. 8B, the insertion tip 815B comprises a rough or textured lower surface for gripping a bone of the joint (e.g., a tibia). In some embodiments, a gripping material may be provided on one or more surfaces of the insertion tips 815A-B to accomplish the same. Additional or alternative means for gripping the bone surface may be implemented as would be known to one having an ordinary level of skill in the art.

The insertion tips 815A-B may be selectively detachable from the arms 805A-B. In some embodiments, the arms 805A-B include a mating portion at their distal ends. For example, as shown in FIG. 8D, each arm 805A-B includes a receptacle such as a through-hole at the distal end. Each of the insertion tips 815A-B comprises a complementary mating portion at the proximal end configured to mate with the mating portion of the arms 805A-B. For example, the insertion tips 815A-B are depicted as having a shaft or stem portion configured to mate with the receptacles of the arms 805A-B. The mating portions may lock together in a variety of manners, such as an interference fit, a snap-fit mechanism, or other manners known to one having an ordinary level of skill in the art. In some embodiments, the mating portions lock together in a specific orientation to ensure that the insertion tips 815A-B are oriented properly with respect to the arms 805A-B. In some embodiments, the insertion tips 815A-B may be adjustable. For example, the shaft portions of the insertion tips 815A-B may lock with the receptacles of the arms 805A-B in a manner that allows free rotation of the insertion tip 815A-B about the axis of the shaft portion without separating from the arm. In some embodiments, where the insertion tips 815A-B are distinct from one another, the mating portions thereof may also be unique to mate specifically with the corresponding arm 805A-B. The mating portions may have unique shapes, sizes, keying features, or other characteristics corresponding to the mating portion of the corresponding arm 805A-B.

In some embodiments, the insertion tips 815A-B may be designed to couple with the arms 805A-B in a plurality of positions. For example, in some embodiments, the insertion tips 815A-B extend in a direction parallel to the rotational axis of the pivot 820. As shown in FIG. 8D, the through-holes of the arms 805A-B extend substantially parallel to the pivot 820 such that the insertion tips 815A-B are inserted within the through-holes at a first side and extend away from the arms in a first direction. The mating portions may be configured such that the insertion tips 815A-B may also be inserted within the through-holes at a second side, opposite the first side, such that the insertion tips 815A-B extend away from the arms 805A-B in a second direction, which is opposite the first direction. The multiple configurations allow for convenient use of the tensioner tool in multiple joints, e.g., both left and right knees of a patient, as further described with respect to FIG. 10. When the insertion tips 815A-B are inserted in any of the plurality of positions, the distance between the insertion tips and the pivot 820 remains fixed (as shown in FIG. 8E) such that the position of the insertion tips does not affect the calculation of distraction force and distraction distance. As such, the tensioner tool 800 does not require re-calibration upon re-configuration of the insertion tips 815A-B.

As shown and described, the insertion tips 815A-B may be designed as a pair adapted for use together with the tensioner tool 800. In some embodiments, a plurality of pairs of insertion tips 815A-B may be provided for use with the tensioner tool 800. The pairs of insertion tips 815A-B may be of a variety of types, each type having a unique shape, size, and/or design. Based on a particular application, a suitable pair of insertion tips 815A-B may be coupled with the arms 805A-B for distraction. For example, in some cases, the most accurate and clinically useful data may be obtained by filling the entire gap between the bones of the joint with the insertion tips 815A-B prior to distraction. The tapering profile of the insertion tips 815A-B is configured to be inserted until the gap between the bones is filled. However, the gap between the bones of a joint may vary from joint to joint and from patient to patient. Accordingly, in some embodiments, the insertion tips 815A-B may be provided in a variety of sizes and/or thicknesses. Each pair of insertion tips 815A-B may have a thickness at the free end selected from 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, and any individual values or ranges between values therein. As such, in each case, a clinician may select the pair of insertion tips 815A-B having the appropriate thickness to fill the entire gap between the bones of the joint. Additionally, the increasing thickness of the insertion tips 815A-B towards the proximal end may be provided for by a variety of slopes. While one example of the slope is demonstrated in FIGS. 8A-8D, the slope may be gentler or steeper as desired. In some embodiments, pairs of insertion tips 815A-B having a variety of slopes are provided such that a suitable pair of insertion tips 815A-B may be selected to best fit the contours of the bones.

Further, the pairs of insertion tips 815A-B may include a variety of different shapes, sizes, and designs. For example, in some embodiments, insertions tips 815A-B may be provided in a plurality of sizes to accommodate anatomies of varying sizes. In some embodiments, a first pair of insertion tips 815A-B may be provided in a first size for an average sized anatomy, a second pair of insertion tips 815A-B may be provided in a second size having a smaller contact surface than the first size for a below average sized anatomy, and a third pair of insertion tips 815A-B may be provided in a third size having a larger contact surface than the first size for an above average sized anatomy. In some embodiments, each insertion tip size may additionally or alternatively provide varying spacing between the prongs of the insertion tips 815A-B. A greater or lesser number of sizes of insertion tips 815 may be provided in order to efficiently provide suitable insertion tips for different anatomy size ranges. In some embodiments, the anatomy size comprises the overall size of the femur and/or the tibia of a patient. In some embodiments, the anatomy size comprises the size of the particular condyle, condyles, or other anatomical features with which the insertion tip is configured to interface. In another example, insertion tips 815 may be provided in a plurality of shapes or designs for interfacing with different features of bones. In some embodiments, the plurality of pairs of insertion tips 815 comprises a first pair of insertion tips with a first design configured to interface with the medial condyles of a knee joint (i.e., inserted in the medial compartment) and a second pair of insertion tips with a second design configured to interface with the lateral condyles of a knee joint (i.e., inserted in the lateral compartment). In some embodiments, the plurality of pairs of insertion tips 815 additionally or alternatively comprises a third pair of insertion tips with a third design configured to interface with both the medial and lateral condyles simultaneously (i.e., inserted in both the medial and lateral compartments). In another example, insertion tips 815 may be provided in a plurality of shapes or designs for different stages of an operation. In some embodiments, the plurality of pairs of insertion tips 815 comprises a first pair of insertion tips having a first shape or design configured to interface with the bones prior to bone resection (e.g., pre-operatively) and a second pair of insertion tips having a second shape or design configured to interface with the bones after one or more resections. In another example, insertion tips of a variety of designs configured for insertion into different joints (e.g., knee, shoulder, an elbow, ankle, hip, and the like) in order to facilitate use of the tensioner tool with different joints.

In some embodiments, the various shapes, sizes, and designs of the insertion tips 815A-B does not affect the distance between the insertion tips and the pivot 820. Since this distance remains fixed (as shown in FIG. 8E), the type of the insertion tips 815A-B does not affect the calculation of distraction force and distraction distance. As such, the tensioner tool 800 does not require re-calibration upon replacement of the insertion tips 815A-B.

In some embodiments, the insertion tips 815A-B are disposable and/or configured for one-time use. In some embodiments, the insertion tips 815A-B are re-usable. In some embodiments, the insertion tips 815A-B are configured for sterilizing or autoclaving. In some embodiments, the insertion tips 815A-B are configured to be placed within a sleeve during use such that the insertion tips 815 do not directly contact the patient or other elements of the surgical environment, thereby maintaining sterility. In some embodiments, the insertion tips 815A-B may be customized with a patient-specific size, shape, design, or other features as described herein for interfacing with a surface of the patient's operative joint in a consistent and predictable manner.

Referring now to FIGS. 9A-9B, several views of another example embodiment of a tensioner tool are illustrated. The tensioner tool 900 may further be incorporated within a CASS (e.g., CASS 100 shown in FIG. 1). The tensioner tool 900 comprises a first arm 905A and a second arm 905B coupled by a pivot 920 located along the length of the arms 905. The first arm 905A comprises a handle portion 910A at the proximal end and an insertion tip 915A formed as a two-pronged tip at the distal end. The two-pronged design for engaging the femur may allow the insertion tip 915A to cradle a condyle of the femur and self-center upon the condyle by sliding along the surface of the condyle as the insertion tip is placed and/or retracted. Accordingly, tensioning across a plurality of measurements may be performed with at more consistent location. Similarly, the second arm 905B comprises a handle portion 910B at the proximal end and an insertion tip 915B formed as a one-pronged tip at the distal end. In some embodiments, the insertion tips 915A-B may be integrally formed with the tensioner tool 900 and may be oriented in the same plane as the handles 910A-B so as to be “front-facing” tips as shown in FIG. 9A. The pivot 920 that joins the arms 905A-B is located between the handle portions 910A-B and the insertion tips 915A-B on the respective arms 905A-B. In some embodiments, the arms 905A-B may include a loading arm and a flexing arm. For example, as shown in FIG. 9A, the first arm 905A may be formed as a flexing arm having a predetermined amount of flexibility, and the second arm 905B may be formed as a loading arm having relatively little flexibility compared to the first arm 905A. In other embodiments, the first arm 905A may be a loading arm, and the second arm 905B may be a flexing arm. In some embodiments, the arms 905A-B may have a similar design and similar degree of flexibility (e.g., as shown and described with respect to tensioner tool 800). In order to form the pivot 920, the first arm 905A may include two parallel flanges 935 with through holes formed therein. The second arm 905B includes at least one protrusion extending through a through hole in order to form the pivot joint. In another embodiment, each arm 905 may include a hole extending orthogonal to the longitudinal axis of the arm. The holes are aligned and a pivot pin is placed therethrough, thus coupling the arms 905 while permitting pivotal movement about the pivot pin (e.g., as shown and described with respect to tensioner tool 800). The tensioner tool 900 may be moved between a closed configuration and an open configuration by pivotal movement of the arms 905A-B about the pivot 920. The pivot 920 is configured to allow manual separation of the insertion tips 915A-B by applying force to the handle portions 910A-B of the arms 905A-B. Similar to the embodiment of FIG. 8, the insertion tips 915A-B can be moved from a closed configuration to an open configuration when force is applied at the handle portions 910A-B.

As shown in FIG. 9B, in an embodiment the tensioner tool 900 comprises one or more force sensors 925 located upon the first arm 905A to measure the force applied to the handle portion 910A. In some embodiments, the one or more force sensors 925 are located distally of the pivot 920. For example, as shown in FIG. 9B, the one or more force sensors 925 may be adjacent to the prongs of the insertion tip 915A. However, a force sensor 925 may be placed in additional or alternative locations upon the arms as described herein. In some embodiments, the tensioner tool 900 includes an array of force sensors 925 which may be utilized to provide additional information and accuracy as described herein. Additional locations and arrangements of force sensors 925 will be apparent to one having an ordinary level of skill in the art. In some embodiments, the one or more force sensors 925 comprise one or more strain gauges. However, any types of force sensors could alternatively or additionally be utilized with the tensioner tool 900. In some embodiments, the arm 905A may include one or more concentration features configured to concentrate stress forces at the location(s) of the one or more force sensors 925. For example, the one or more concentration features may include holes, grooves, notches, fillets, or other irregularities in the design of the arm 905A-B that concentrates the stress forces resulting from a force applied at the handle portion 910A-B.

Referring again to FIG. 9A, the tensioner tool 900 comprises one or more positional sensors 930 in order to facilitate calculation of a tip distance between the insertion tips 915A-B (i.e., a distraction distance during distraction of a joint). As shown in FIG. 9A, the positional sensor 930 may be contained within the joint of pivot 920 and configured to measure a rotational displacement at the pivot. The pivot 920 has a known spatial relationship with the distal end of the tensioner tool. As such, the distraction distance at the insertion tips 915A-B may be calculated according to the equation:

$distraction distance = \sqrt{L_{P 1}^{2} + L_{P 2}^{2} - 2 L_{P 1} L_{P 2} \cos (θ_{rot})}$

where L_P1is a first prong length (i.e., the length of the first arm 905A from the pivot 920 to the insertion tip 915A), L_P2is a second prong length (i.e., the length of the second arm 905B from the pivot 920 to the insertion tip 915B), and θ_rotis the angular displacement measured by the positional sensor 930 at the pivot 920.

In some embodiments, the one or more positional sensors 930 comprise one or more rotary encoders. The rotary encoder may be inserted within the pivot 920 in order to measure rotational displacement. Other types of rotational sensors could alternatively or additionally be utilized. In some embodiments, the one or more positional sensors 930 may include a rotary potentiometer. In some embodiments, the one or more positional sensors 930 may include an orientation sensor located along the length of the arms. For example, the one or more positional sensors 930 may comprise an inertial measurement unit configured to measure a change in the orientation of the arms. In some embodiments, the tensioner tool 900 includes a plurality of positional sensors 930 at the pivot 920 to more accurately calculate the distraction distance. In some embodiments, the one or more positional sensors 930 further include one or more sensors configured to measure a separation distance at a location along the arms 905A-B, as shown and described with respect to FIG. 8. Additional locations and arrangements of positional sensors 930 will be apparent to one having an ordinary level of skill in the art. In some embodiments, the positional sensors 930 may be removable from the tensioner tool 900. For example, as shown in FIG. 9A, the rotary encoder 930 may be removable from the pivot 920. In some embodiments, the positional sensor 930 may be designed as a disposable component. In some embodiments, the positional sensor 930 may be designed as a reusable component which may be removed and replaced in the pivot 920 to facilitate sterilization and calibration procedures. In some embodiments, the positional sensor 930 may be embedded and/or integrally formed with the tensioner tool 900.

Referring once again to FIG. 9A, the tensioner tool 900 may comprise sensing electronics 940, which include additional electronic components needed to capture the force data and separation data from the one or more force sensors 925 and the one or more positional sensors 930. In some embodiments, the sensing electronics 940 include a processor. The processor may receive force data including applied force measurements from the one or more force sensors 925 and separation data including rotational displacement measurements from the one or more positional sensors 930. In some embodiments, the processor utilizes the force data and the separation data to perform calculations. Various additional components which may be included in the sensing electronics 940 are described and depicted fully with respect to tensioner tool 800 (i.e., sensing electronics 840). As shown in FIG. 9A, the sensing electronics 940 may be coupled to a display interface 945 located on one of the handles 910 or elsewhere on the tensioner tool 900 to display information derived from the force data and the separation data (e.g., distraction force and distraction distance), such that the tensioner tool 900 can act as a standalone device. Examples of the calculations that may be performed by the processor and information that may be displayed on the display interface of the tensioner tool are described in greater detail with respect to the system of FIG. 11. In some embodiments, the tensioner tool 900 may include one or more buttons or other means of controlling the function of the processor, display, and sensing electronics. The tensioner tool 900 may comprise a power button, a display button, and/or a calibration button such as a “zero out” or “tare” button as fully described herein.

In some embodiments, the tensioner tool 900 may additionally or alternatively include communication electronics configured to transmit the signals to an external computing device (e.g. the surgical computer 150 of the CASS 100) to perform calculations as described herein. The communication electronics may comprise any of the various embodiments described and discussed with respect to tensioner tool 800. For example, the tensioner tool 900 may comprise a communication interface such as a port or adapter to provide wired connection to the external computing device. In another example, the communication interface comprises a wireless transmission system for wireless communication with the external computing device. The force data and the separation data may be sent via the communication interface for remote processing.

In some embodiments, the tensioner tool 900 comprises a power source. For example, an on-board power source such as a battery may be included in communication with the sensing electronics 940. In some embodiments, the tensioner tool 900 comprises a power interface such as those described with respect to tensioner tool 800. In some embodiments, a single interface may be utilized as a communication interface and a power interface.

In some embodiments, tensioner tools may comprise a reusable component configured to sterilization (e.g., by autoclave) and a disposable component configured for one-time use and disposal. Referring now to FIGS. 15A-15B, several views of an illustrative tensioner tool 1500 with reusable and disposable components is depicted in according with an embodiment. The tensioner tool 1500 may be substantially similar to the tensioner tool 900 of FIG. 9 and may include any of the components, features, and characteristics described with respect to the tensioner tool 900, except as discussed herein. As shown, a reusable component 1505 comprises the first arm, the second arm, and the pivot of the tensioner tool. The reusable component 1505 may also comprise the force sensors and/or positional sensors located on the first arm and/or second arm. A disposable component 1510 may comprise the sensing electronics and/or the communication electronics (e.g., as described with respect to the tensioner tool 900) and may be configured to mate with the reusable component 1505 to operably communicate with the force sensors and/or positional sensors of the reusable component 1505. For example, electrical connectors of the reusable component 1505 and the disposable component 1510 may be mated to permit electrical communication by the force sensors and/or positional sensors with the sensing electronics and/or the communication electronics. Furthermore, the reusable component 1505 and the disposable component 1510 may comprise complementary mating features to secure or lock the disposable component 1510 to the reusable component 1505 in a removable manner. For example, the complementary features may include a protruding tab configured to mate with a corresponding recess and/or a protruding ridge configured to mate with a corresponding groove as shown in FIG. 15B. Accordingly, the components of the disposable component 1510 may receive measurements from the components of the reusable component 1505 and may be perform calculations based on the measurements and/or transmit the measurements to an external computing device (e.g. the surgical computer 150 of the CASS 100) as described.

The tensioner tool 1500 may be advantageous because the reusable component 1505 contains only components that are suited for sterilization via autoclave without degrading the capabilities of the tensioner tool 1500 and/or the accuracy of measurements and calculations performed therewith. Furthermore, because the disposable component 1510 is intended for one-time use, the components thereof may be limited to reduce the cost of manufacture. The disposable component 1510 may also promote cyber security. For example, while the tensioner tool 1500 is depicted as being configured for wired communication via a cable, the tensioner tool 1500 may configured for wireless communication, e.g., a Bluetooth transmission, by inclusion of a wireless communication interface and/or electronics as described herein. Wireless communication relies on a strong cybersecurity platform to eliminate vulnerabilities that may compromise patient data or prevent opportunities for hacking. Cybersecurity may vary between hospitals and/or facilities. However, the use of Bluetooth transmission by a one-time use, disposable component 1510, there is a significant reduction of the opportunity and likelihood that data may be compromised. Accordingly, the tensioner tool 1500 promotes secured transmission of patient data.

FIG. 10 depicts a tensioner tool inserted in a knee joint in accordance with an embodiment. A tensioner tool 1000 (e.g., tensioner 800 of FIG. 8) is inserted between the femur and the tibia of a knee joint. The insertion tips of the tensioner tool 1000 may be sized and shaped to be inserted between one condyle of a femur and one corresponding condyle of a tibia. In an embodiment, the insertion tips of the tensioner tool 1000 may be inserted in the medial compartment of a knee joint. However, the insertions ends may be sized and shaped to be inserted between lateral condyles, between both condyles individually, between both condyles simultaneously, and/or additional features of the femur and tibia. When inserted, applying a force to a handle of the tensioner tool 1000 may cause a distraction force at a contact surface upon the bones, i.e., a surface of the insertion tips in contact with the bones. The applied force may be sensed and registered by the force sensors. Further, the distraction force may cause the femur and the tibia to separate, resulting in pivoting of the arms of the tensioner tool. A separation measurements (e.g. a separation distance at a position along the arms and/or a rotational displacement) may be sensed and registered by the positional sensors. Each sensor may communicate signals indicative of the measurements to on-board sensing electronics of the tensioner tool 1000 and/or directly to an external device via a communication interface (e.g., a wired connection or a wireless transmission system) to perform calculations as described herein. The tensioner tool 1000 may include an on-board power source or a wired connection to receive power. In some embodiments, a single wired connection and/or interface may be utilized for communication and power.

As described with respect to FIG. 8, the insertion tips may be designed to couple with the arms in multiple configurations allow for convenient use of the tensioner tool in multiple joints, e.g., both left and right knees of a patient. For example, as shown in FIG. 10, the insertion tips may be inserted at the first side of the tensioner tool for use in tensioning a patient's left knee with the arms oriented medially. The insertion tips may be also be inserted at the second side for use in tensioning a patient's right knee joint with the arms similarly oriented medially. This orientation allows the patella to be reverted to the native position during tensioning, thus providing a more natural position of the joint and more accurate distraction measurements.

While FIG. 10 depicts the use of the tensioner tool 1000 with the knee joint in flexion, the tensioner tool 1000 may also be used with the knee joint in extension. In some embodiments, the tensioner tool 1000 may be utilized to capture data at each of a plurality of positions along the range of motion of the knee joint. In some embodiments, the knee joint may be moved through the range of motion with the tensioner tool 1000 inserted in order to capture data at a plurality of positions. Additionally, while FIG. 10 depicts the tensioner tool 1000 in use on native condyles, the tensioner tool 1000 may also be used intraoperatively after one or more bone cuts. In some embodiments, the tensioner tool 1000 may be used after cutting one or more of the distal femur and the proximal tibia, e.g., to assess the medial and collateral ligaments under tensioning and/or assess a suitable prosthesis thickness. For example, a distraction distance may be utilized to determine the suitable prosthesis thickness In some embodiments, the tensioner tool 1000 may be used after prosthesis implantation in order to assess postoperative distraction force and data. In some embodiments, the tensioner tool 1000 may be used before bone cuts, after one or more bone cuts, and/or after prosthesis implantation in order to compare distraction force and/or distraction distance at each stage.

Referring now to FIG. 11, a block diagram of an illustrative system for tensioning a joint during a surgical procedure in accordance with an embodiment is depicted. As shown in FIG. 11, the system 1100 may include a computing device 1105 and a tensioner tool 1110. In some embodiments, the system 1100 is a surgical system or a robotic surgical system. The tensioner tool 1110 may be any of the embodiments depicted and/or described herein (e.g., tensioner tool 800 of FIG. 8 or tensioner tool 900 of FIG. 9). The tensioner tool 1110 is in electronic communication with computing device 1105 so as to relay signals from the sensors (e.g., force sensors and positional sensors) to the computing device 1105. In some embodiments, the computing device is an on-board processor of the tensioner tool 1110 (e.g., as part of the sensing electronics 840 of the tensioner tool 800). In some embodiments, the computing device 1105 is an external computing device such as a tablet computer, mobile device, the computing device of a CASS, or other types of computing or data processing systems as described herein. In some embodiments, electronic communication between the tensioner tool 1100 and the computing device 1105 may be wired. In additional embodiments, electronic communication between the tensioner tool 1100 and the computing device 1105 may be through a wireless transmission system.

The computing device 1105 receives, via the electronic communication, signals from the force sensors indicative of force measurements registered by each individual force sensor (i.e., force data). Similarly, the computing device 1105 receives signals from the positional sensors indicative of separation distance measurements and/or rotational displacement measurements registered by each individual positional sensor (i.e., separation distance data). The computing device 1105 utilizes known parameters related to the sensors to perform various calculations. In some embodiments, the computing device 1105 may utilize the force data in conjunction with the known properties and geometry of the tensioner tool 1110 to calculate the distraction force at the insertion tips. Where a plurality of force sensors are utilized, the computing device 1105 may calculate a distraction force based on the force data from each individual force sensor and average the calculated distraction forces to obtain an improved approximation of the distraction force. In some embodiments, the computing device 1105 may utilize the separation data in conjunction with the known properties and geometry of the tensioner tool 1110 to calculate the distraction distance at the insertion tips. In some embodiments, the force data may be utilized as a calibration factor in the distraction distance calculations. For example, where high loads are applied, the tensioner tool 1110 may experience bending at various locations, thus affecting the geometry of the tensioner tool 1110 in a manner not accounted for in the separation data. In other words, the bending of the tensioner tool 1110 affects the relationship between the separation data and the distraction distance. As such, the force data may be utilized to estimate any deformation of the tensioner tool 1110 and account for the deformation in the distraction distance calculations. Where a plurality of positional sensors are utilized, the computing device 1105 may calculate a distraction distance based on the separation data from each individual positional sensor and average the calculated distraction distances to obtain an improved approximation of the distraction distance. The known properties and geometry for the calculations may include the distance between the force sensor and the pivot, the distance between the positional sensor and the pivot, the distance between the pivot and the insertion tips, the angle formed by each arm at the pivot, the angle between the handles in the closed configuration, the material properties of the tensioner tool 1110 (e.g., modulus of elasticity), and additional properties of the tensioner tool 1110 as would be known to one having an ordinary level of skill in the art. Further, it is understood that any or all of the described calculations and information could alternatively be performed and provided on-board by a processor of a standalone tensioner tool as described with respect to FIG. 8.

Referring again to FIG. 11, the system 1100 may include one or more displays 1115 in wired or wireless electronic communication with the computing device 1105. The one or more displays 1115 may display, for example, information pertaining to the distraction force and distraction distance. In an embodiment, the one or more displays 1115 may include a digital display. Any of the collected or calculated data described herein may be displayed to a user in real-time on the one or more displays 1115. For example, a total magnitude and direction of the distraction force, a distraction distance, and/or a distraction profile may be indicated to a user on a display 1115 as feedback to the user. Further, additional information or data may be indicated on a display 1115. In some instances, the computing device 1105 may have additional information such as a pre-determined force value or range of force values (i.e., target force values) known to provide useful assessment of a patient's joint. As such, the system 1100 may prompt a user via a display 1115 to apply a greater or lesser force in order to reach the target force to obtain useful measurements such as distraction distance. In some embodiments, the appropriate amount or range of force may be pre-determined for all patients. In other embodiments, the appropriate amount or range of force may be adjusted based on various factors, such as one or more contemplated post-operative activities and patient demographics including but not limited to weight, height, size, and age. The system 1100 may also prompt the user to apply less force if an excessive applied force may result in damage to the patient or a component of the system 1100. In additional embodiments, the computing device 1105 may have a pre-determined distraction distance value or range of values (i.e., target distance values) known to provide useful assessment of a patient's joint. As such, the system 1100 may prompt a user via a display 1115 to adjust the distraction distance (greater or lesser) in order to reach the target distance to obtain useful measurements such as distraction force. The appropriate target distance may be pre-determined for all patients or calculated and adjusted based on any of the parameters described above with respect to a target force. The system 1100 may also prompt the user to decrease distraction distance if an excessive distance may result in damage to the patient or a component of the system 1100.

The feedback with respect to the distraction force or distraction distance may be provided in a variety of manners. In some embodiments, the visual feedback indication may include a first color, such as green, if more force or separation should be applied, and a second color, such as red, if less force or separation should be applied. In some embodiments, feedback information for the direction may include an arrow or other visual indication identifying that the user should alter the direction in which the force or separation is applied. In some embodiments, a visual indication identifying a location at which the tensioner tool 1110 should be positioned in order to apply an appropriate magnitude and direction of distraction for a given application may be provided via the display 1115. In further embodiments, the system 1100 may prompt collection of measurements at specific positions along the range of motion of the joint. The system 1100 may additionally prompt collection of measurements at specific locations within the joint (e.g., medial compartment, lateral compartment, etc.). In some embodiments, the measurements may be associated by a user with a particular location within the joint and/or position along the range of motion before or after data collection via a user interface as described herein. In still further embodiments, the computing device 1105 may identify unexpected results and prompt the user to assess one or more components of the system. For example, where the computing device 1105 obtains measurements which do not comport with an expected range of credible measurements, the display 1115 may prompt a user to examine the tensioner tool 1110 as well as connections of the components because the unexpected results may be indicative of a faulty or damaged component, improper assembly of one or more components of the system 1100, and the like. Alternate or additional information may be provided to the user within the scope of this disclosure as will be apparent to those of ordinary skill in the art. In some embodiments, the display 1115 may be an augmented reality headset worn by a user. In some embodiments, the system 1100 may provide additional feedback, such as suggested implant size, suggested amount of tissue release, estimated post-operative tension, estimated varus/valgus alignment, and the like. Further, it is understood that any information that may be displayed on an external display 1115 may additionally or alternatively be displayed on an on-board display interface of the tensioner tool and vice versa. In other embodiments, other manners of feedback may additionally or alternatively be utilized, such as auditory signals. An auditory signal or other feedback may be emitted from a component of the system 1100 or, in the case of a standalone tensioner tool, from the tensioner tool itself (e.g., a sound emitting component communicating with the sensing electronics).

In some embodiments, the computing device 1105 is a WiFi- or broadband cellular-enabled device. The computing device 1105 may communicate collected and/or calculated data to one or more destinations. For example, the data may be communicated to a local storage unit, a remote computer, a remote database, a server, and/or a cloud network. In some embodiments, the computing device 1105 transmits the data to a WiFi- or cellular-enabled device via another wired or wireless communication means and the WiFi- or cellular-enabled device in turn relays the data to the one or more destinations. For example, the WiFi- or cellular-enabled device may be a tablet computer, mobile device, laptop computer, desktop computer, or other data processing system as described herein. In some embodiments, the computing device 1105 and/or the display 1115 may be integrated into the WiFi- or cellular-enabled device. For example, a tablet computer or mobile device may receive measurement data from the tensioner tool 1110 and perform calculations via a local processor 1105. In some embodiments, the system 1100 comprises multiple such WiFi- or cellular-enabled devices, each having a computing device 1105 and a display 1115 such that the tensioner tool 1110 may communicate data with any of the interfaces. In some embodiments, data may be shared or synced across the devices by wired or wireless communication.

In some embodiments, where an external device is utilized (e.g., a tablet computer or mobile device as described herein), a software application on the external device may be utilized to display to a user the distraction forces, distraction distances, distraction profiles, and any other information provided to or determined by the computing device 1105 and/or provided to the display 1115. In some embodiments, a user interface of the external device may be utilized to receive user input and/or perform further calculations. For example, the display 1115 and user interface of such an external device may be utilized during data collection to associate measurements with a particular location within the joint and/or position along the range of motion. In some embodiments, one or more measurements taken after bone resection (e.g., separation distance) may be recorded and utilized to determine a suitable implant thickness. For example, the tensioner tool may record a total distance between the bones at a desired tension in order to identify the required implant thickness. In some embodiments, additional input may be received through the user interface. For example, an implant type, family, and/or size may be selected through the user interface. The computing device 1105 may utilize the dimensions and other information associated with the selected implant to perform further calculations. For example, based on the implant information, the computing device 1105 may calculate and report a tension and/or varus/valgus alignment of the post-operative knee. In some embodiments, the user may select a plurality of implants and compare the calculated post-operative data for each of the implants through the user interface. In some embodiments, the computing device 1105 may perform the calculations for a plurality of implants and identify one or more suggested implants for the user to review and/or compare.

Systems utilizing a software application on a tablet, mobile device, or other smart device may be particularly advantageous because use of the tensioner tool 1110 may not be dependent on a specific computer-assisted surgical system (e.g., CASS 100 of FIG. 1). Rather, while the tool may be compatible with the CASS 100, the tensioner tool 110 may also be used with any other surgical system and/or used independently to obtain the distraction forces, distraction distances, distraction profiles, recommendations for a surgical plan, and any other information related to the joint, which may be provided to the user by the software application.

In some embodiments, the tensioner tool 1110 may require calibration prior to data collection. In some embodiments, the calibration comprises collecting force data in response to the application of one or more known quantities of force. The computing device 1105 may utilize the collected data to determine the precise relationship between the quantified measurements from the force sensors and the applied force. In some embodiments, the calibration comprises collecting separation data in response to one or more known separation distances between the arms of the tensioner tool 1110 along a length thereof. The computing device 1105 may utilize the collected data to determine the precise relationship between the quantified measurements from the positional sensors and the separation of the arms. In some embodiments, calibration is performed prior to obtaining a first measurement. In some embodiments, certain changes to the system or the tensioner tool do not affect calculations and thus re-calibration is not required thereafter. For example, as described, repositioning the insertion tips from a first side to a second side of the tensioner tool may not require re-calibration. Further, replacing one type of insertion tip with another type of insertion tip may not require re-calibration. In some embodiments, certain changes to the system or the tensioner tool require re-calibration of the tensioner tool. For example, where a sensor is removed, re-positioned, or replaced, re-calibration may be required. In some embodiments, where a Hall effect sensor and magnet are utilized for collecting separation data, re-calibration may be required if a magnet is removed, re-positioned, or replaced. In some embodiments, the system 1100 may prompt a user to calibrate and/or re-calibrate the tensioner tool 1110 at appropriate times.

Referring once again to FIG. 11, additional or optional features of the system 1100 are depicted in broken lines. In some embodiments, the robotic surgical system 1100 may additionally comprise a tracking system 1120 in wired or wireless electronic communication with the computing device 1105. In an embodiment, the tracking system 1120 is configured to be attached to one or more portions of the patient's anatomy into which the tensioner tool 1110 is inserted to improve the detail of the measurements obtained using the tensioner tool. In an embodiment, the tracking system 1120 includes one or more patient trackers 1125 (e.g., optical tracking arrays). The one or more patient trackers 1125 can be attached to one or more of the patient's tibia and femur. In an embodiment, the one or more patient trackers 1125 may be attached to each of the patient's tibia and femur and may be configured to record one or more location data points that may be indicative of the relative orientation of the tibia and femur as the tensioner tool 1110 is inserted between the patient's tibia and femur and moved, for example, as a force is applied to the handle of the tensioner tool. In an embodiment, the relative orientation of the tibia and femur includes the locations of the tibia and femur. In an embodiment, the relative orientation of the tibia and femur includes the distance between the tibia and femur. In an embodiment, the relative orientation of the tibia and femur includes the angle between the tibia and femur relative to one or more of the distal-proximal axis, the anterior-posterior axis, and the medial-lateral axis. In an embodiment, the relative orientation of the tibia and femur includes a flexion angle of the tibia and femur.

Further, the patient trackers 1125 of the tracking system 1120 may facilitate additional calculations by the computing device 1105. For example, the computing device 1105 may receive information from the tracking system 1120 regarding the flexion and/or extension of the joint, and thus associate each set of distraction measurements (e.g., distraction force and distraction distance) with a discrete position along the range of the motion of the joint. Measurements may be collected at a plurality of discrete positions to create a distraction profile with respect to the range of motion of the joint.

In further embodiments, the tracking system 1120 includes one or more tool trackers 1130 (e.g., optical tracking arrays). The one or more tool trackers 1130 are configured to record one or more location data points indicating one or more of the location, the orientation, and the motion of the tensioner tool 1110 and provide at least one of these data points to the computing device 1105. The one or more tool trackers 1130 can be attached to the tensioner tool 1110 and may be configured to record one or more location data points that may be indicative of the relative position, orientation, and motion of the tensioner tool 1110. In conjunction with one or more patient trackers 1125, the tracking system 1120 and the computing device 1105 may determine the location, orientation, and motion of the tensioner tool 1110 with respect to the patient anatomy based on the known dimensions and geometry of the tensioner tool 1110 with respect to the tool trackers 1130. Further, the tool trackers 1130 of the tracking system 1120 may facilitate additional calculations by the computing device 1105. For example, the computing device 1105 may receive information from the tracking system 1120 regarding the location and orientation of the tensioner tool 1110 with respect to the patient anatomy. The computing device 1105, based on known parameters related to the tensioner tool 1110 and the patient anatomy, can approximate contact points on the bones of the joint.

The system 1100 may include more or fewer components in certain examples. For example, the system 1100 may not include a display 1115, a patient tracking system 1120, and/or one or both of patient trackers 1125 and tool trackers 1130. In some embodiments, the display 1115 is integrated into the tensioner tool 1110 as an on-board display interface. In some embodiments, both an on-board display interface 1115 and an external display 1115 may be included.

FIG. 12 depicts a flow diagram 1200 of an illustrative method of tensioning a joint during a surgical procedure in accordance with an embodiment. As shown in FIG. 12, a tensioner tool (e.g., tensioner tool 800 of FIG. 8) is inserted 1205 into a portion of a joint, a force is applied 1210 to a handle portion of the tensioner tool, force data and separation data from one or more locations of the tensioner tool are received 1215 by a computing device, and the distraction force and distraction distance at a contact surface of the joint are calculated 1220. In some embodiments, the joint may be a knee. However, the tensioner tool may be inserted 1205 into other joints, such as a shoulder, an elbow, an ankle, a hip, or the like, within the scope of this disclosure. The tensioner tool to be inserted may include any of the embodiments described further herein. In some embodiments, separation data comprises separation distance at one or more locations along the arms of the tensioner tool. In some embodiments, separation data additionally or alternatively comprises rotational displacement at the pivot of the tensioner tool. In some embodiments, the method described may be performed prior to any resection of bone in order to determine a natural tension of the joint. In some embodiments, the method described may additionally or alternatively be performed after resection of the bone and/or implantation, e.g., to compare the post-operative joint tension to a previously measured natural tension.

In an example, the method comprises making an incision to access the bones of a knee joint, inserting the tensioner tool between the condyles of the distal femur and proximal tibia, and applying a force to measure distraction force and distraction distance. The method may further comprise removing the tensioner tool, placing surgical instruments, performing bone cuts, and implanting the joint prosthesis. The method may further comprise re-inserting the tensioner tool between the condyles of the prosthetic joint and applying a force to measure distraction force and distraction distance. The distraction information of the native joint and the implanted prosthetic joint may be compared as described herein and thereafter the incision may be closed.

In another example, the method comprises making an incision to access the bones of a knee joint, placing surgical instruments, and performing one or more bone cuts. The method may further comprise inserting the tensioner tool femur and tibia and applying a force to measure distraction force and distraction distance. In some embodiments, the tensioner tool may be utilized after the one or more bone cuts to assess medial and collateral ligaments and/or determine a desired prosthesis thickness. For example, the medial and collateral ligaments may be assessed under a distraction force and distance to identify a suitable prosthesis. For example, the distraction distance may be utilized to identify a suitable prosthesis thickness. The method may further comprise removing the tensioner tool, performing one or more additional bone cuts, and implanting the joint prosthesis. The method may further comprise re-inserting the tensioner tool between the condyles of the prosthetic joint and applying a force to measure distraction force and distraction distance. The distraction information of intraoperative joint and the implanted prosthetic joint may be compared as described herein and thereafter the incision may be closed. The examples provided are intended as non-limiting in nature and additional embodiments are contemplated. In some embodiments, distraction of the joint may be measured for the native joint (i.e., prior to any bone cuts), after at least one bone cut, and after prosthesis implantation (i.e., after all bone cuts and placement of the prosthesis).

In a further embodiment, the device may further include one or more tool trackers configured to record one or more location, orientation, and motion data points as the device is moved. These data points may be indicative of the motion of the tensioner tool or one or more components thereof as described herein. In a further embodiment, one or more patient trackers may be attached to the portion of the joint before applying a force 1210. The patient trackers may be configured to record one or more location, orientation, and motion data points as the tensioner tool is moved that may be indicative of the portion of the joint. The location, orientation, and motion data points from the tool trackers and the patient trackers may be received by a computing device, including a robotic surgical system or a surgical system, and used to account for the location of the tensioner tool with respect to the joint, in order to facilitate more accurate measurement of the applied force as well as additional calculations with respect to the distraction as described herein. For example, in some embodiments, the computing device determines approximate contact points of the tensioner tool with the bones in order to ensure a degree of consistency across several distraction measurements (e.g., pre-operative measurements and post-operative measurements) and/or account for discrepancies therein. In some embodiments, the joint may be moved through a range of motion, and a force may be applied at one or more discrete positions. Measurements may be collected at each discrete position to create a distraction profile with respect to the range of motion of the joint.

The devices, systems, and methods as described herein are not intended to be limited in terms of the particular embodiments described, which are intended only as illustrations of various features. Many modifications and variations to the devices, systems, and methods can be made without departing from their spirit and scope, as will be apparent to those skilled in the art.

While the tensioner tools are described and depicted as pivoting plier-type tools, additional configurations are contemplated herein. While the illustrated tensioner tools 800 and 900 are described as including a pair of stacked arms, other arrangements of the arms are possible. In some embodiments, the arms may be arranged in a scissors-type configuration. The arms may cross at the pivot such that a first arm is arranged above a second arm proximally of the pivot and arranged below the second arm distally of the pivot. Further, while the illustrated tensioner tools 800 and 900 are described as including pivotally coupled arms, other types of coupling are possible. In some embodiments, the joint may be a linearly displacing joint. In some embodiments, the joint between the arms may comprise a sliding lever mechanism or another linearly displacing mechanism. Additionally, while the illustrated tensioner tools 800 and 900 are configured to separate the insertion tips by applying a force at the handles to move the handle portions toward one another, other arrangements and configurations are possible. In some embodiments, the insertion tips may be separated by applying a force at the handle portions to move the handle portions away from one another. For example, the tensioner tool may comprise two arms arranged in a scissors-type configuration with a linearly displacing joint. A force may be applied at the handles by squeezing the handle portions toward one another to cause the insertion tips on the distal portions of the arms to separate. Accordingly, the tensioner tool could be utilized to distract the bones of a joint as described herein. In another example, the tensioner tool may comprise two arms arranged in a scissors-type configuration with a pivoting joint. A force may be applied at the handles to spread the handle portions away from one another to cause the insertion tips to separate. Accordingly, the tensioner tool could be utilized to distract the bones of a joint as described herein. In another example, the tensioner tool may comprise two arms arranged in a pliers-type stacked configuration with a linearly displacing joint. A force may be applied at the handles to spread the handle portions away from one another to cause the insertion tips to separate. Accordingly, the tensioner tool could be utilized to distract the bones of a joint as described herein. In some embodiments, such as any of the described and depicted configurations, the arms may be biased in the open configuration. For example, biasing members such as springs may be utilized to bias the arms into an open configuration. Accordingly, the arms may be switched to the closed configuration under an applied for at the handle portions. Upon partial or total release of the applied force, the arms may separate once again to tension the joint.

In any of the described embodiments, the joint between the arms of the tensioner tool (e.g., pivot or linearly displacing mechanism) may include a locking mechanism to maintain a set separation between the arms. In some embodiments, the locking mechanism may be a ratchet mechanism. By locking a separation of the arms, a surgeon can free her hands in order to assess the joint by feel or perform other tasks while maintaining a set distraction force and distance between the bones of the joint. Particularly, in embodiments where the tensioner tool is utilized after one or more bone resections as described herein, the locking mechanism is advantageous for assessing the bones and ligaments and/or determining a desired prosthesis thickness. In some embodiments, assessment may be performed at a plurality of locked positions of the arms to determine an optimal prosthesis thickness.

While the tensioner tools are described and depicted as including two arms, in some embodiments the tensioner tool may comprise a single arm (e.g., a tensioning fork). The single arm tensioner tool may be inserted within a joint and, utilizing a portion of the bone as a fulcrum, pivot the tensioner tool under an applied force at the handle portion in order to tension the joint. A strain gauge or force sensor along the arm may be utilized to measure an applied force and calculate a distraction force as described. Additionally, the tensioner tool may include an inertial measurement unit (IMU) to measure a change in the orientation of the device and calculate a distraction distance. Other sensors capable of detecting a change in orientation may also be utilized.

In embodiments, where tension is applied at the medial and lateral compartments simultaneously, additional functions and measurements may be provided for. In some embodiments, the tensioner tool may include separately movable medial insertion tips and lateral insertion tips, thereby allowing each compartment to be distracted individually. In some embodiments, the tensioner tool may include lower insertion tips for both compartments and separate movable upper insertion tips for each compartment, thereby allowing each compartment to be distracted individually. In some embodiments, separate arms may be provided for distraction of each compartment. In some embodiments, the separate arms have a joint handle portion such that both compartments are distracted under a single applied force. In some embodiments, the separate arms have separate handle portions to allow separate applied forced to each compartment. In such embodiments, additional sensors are utilized to collect additional measurements. For example, sensors may be included at an interface between the medial and lateral arms or insertion tips of each compartment. In some embodiments, the sensors measure an angle between the medial and lateral arms or insertion tips (i.e., alignment data). In some embodiments, the measurements may be relevant to additional calculations such as varus/valgus alignment.

While the insertion tips are described and depicted as abutting one another in the closed configuration, additional configurations are contemplated herein. In some embodiments, the insertion tips may be spaced by a predetermined distance in the closed configuration and spaced by a distance greater than the predetermined distance in the open configuration. In some embodiments, the space between the insertion tips in the closed configuration varies. For example, where removable insertion tips are utilized, the space may vary based on the dimensions and design of each pair of insertion tips. In some embodiments, the distance between the insertion tips in the closed configuration is extraneous to the distraction calculations and thus not precisely known or recorded. In other embodiments, the distance is known, measured, and/or input by a user for use in certain calculations. Further, while the insertion tips are described as filling an entire space between the bones of the joint when inserted in the closed position, in some embodiments the insertion tips may not fill the entire space. For example, the insertion tips may not be thick enough to contact both a tibia and a femur of a knee joint upon insertion. As such, the separation of the insertion tips may not directly correlate to distraction distance in all cases. In such embodiments, the computing device may utilize force feedback to identify when the arms have been separated sufficiently to contact both bones. For example, the contact forces of the insertion tips with the bones may provide sufficient force feedback for this purpose. By collecting separation data at this position and again during distraction, a change in the separation may be utilized to determine distraction distance as described herein.

While several arrangements of sensors are described and depicted, additional or alternative arrangements of sensors are possible as would be known to one having an ordinary level of skill in the art. In some embodiments, where both arms permit a degree of flexing under an applied force, force sensors may be included on each arm and utilized together to calculate a total applied force. In other embodiments, a first arm is configured as substantially rigid, and a second arm is relatively flexible such that substantially all flexing occurs in the second arm under an applied force. In some embodiments, one or more force sensors may be included at the joint of the arms in addition to or as an alternative to force sensors along the length of the arms as described herein. For example, where the joint is a pivoting joint, a rotational force sensor may be contained within the pivot and/or inserted therein. In some embodiments, the rotational force sensor comprises a torque load cell that measures a joint displacement load at the pivot under an applied force at the handle portions. However, other types of rotational force sensors known to one having an ordinary level of skill in the art are contemplated herein. In another example, where the joint is a linearly displacing joint, a linear force sensor may be contained within the linear displacement mechanism of the joint. In some embodiments, the linear force sensor may comprise a strain gauge that measures a force at the joint as the arms are slidably separated under an applied force at the handle portions. However, other types of linear force sensors known to one having an ordinary level of skill in the art are contemplated herein. Further, while positional sensors arranged on the arms and positional sensors located at the joint are described herein, additional arrangements and variations are possible. For example, where the joint is a linearly displacing joint, a linear positional sensor may be contained within the linear displacement mechanism of the joint. In some embodiments, the linear force sensor comprises a resistive position sensor on an inner surface of the joint (e.g., an inner surface of the sliding arm) that measures a joint displacement at the joint under an applied force at the handle portions. However, other types of linear positional sensors known to one having an ordinary level of skill in the art are contemplated herein.

It should also be understood that modifications to the arrangement, configuration, and/or types of sensors may result in a corresponding modification to the type of measurements collected and/or the necessary calculations to produce distraction force and distraction distance information. For example, where a rotational force sensor is utilized, different mathematical calculations may be required to arrive at a distraction force than would be necessary with strain gauge sensors arranged along the length of the arms. In another example, where linear position sensors are utilized with a linearly displacing joint, different mathematical calculations may be required to arrive at a distraction distance that would be necessary with a rotary encoder arranged at a pivot joint. Such calculations and modifications thereto would be apparent to one having an ordinary level of skill in the art.

While any of the force sensors and/or positional sensors described herein may be formed integrally with the tensioner tool or permanently affixed thereto, the force sensors and/or positional sensors may also be removable. In some embodiments, the sensors are configured to be removed and re-attached at the same or additional locations. In some embodiments, the sensors are configured to be replaced. In some embodiments, calibration of the tensioner tool may be required after re-attaching or replacing one or more sensors. In some embodiments, one or more of the sensors are designed as disposable and configured for one-time use. In some embodiments, one or more of the sensors are designed for re-use and configured to be sterilized or autoclaved.

In some embodiments, the computing device may receive additional data and/or information. For example, as described herein, the computing device may additionally receive alignment data from sensors configured to measure an angle between the medial and lateral compartments. In some embodiments, the computing device may perform additional calculations with existing and/or additional data. For example, the computing device may utilize alignment data to calculate a varus/valgus alignment of the joint. In some embodiments, the computing device may characterize the tissue properties of the ligaments based on the data. In some embodiments, the computing device may perform patient-specific simulations with respect to one or more parameters related to an implant (e.g., specific types of implants, specific sizes of implants, specific placement of implants) based on the data and/or transmit the data or calculations to a separate computing device for performing such simulations. In some embodiments, the computing device may assess the health of the soft tissue, such as ligaments, based on the data. Any or all of the described functions may be performed and/or supplemented by the computing device of a CASS as described herein. In some embodiments, any or all of the described data and assessments may be stored on a computer-readable medium or transmitted to an external location. For example, in some embodiments, data may be transmitted to a remote database comprising data for a plurality of patients (e.g., from a plurality of physicians and/or healthcare settings). Accordingly, the aggregate data may facilitate improved suggestions for surgical plans (e.g., implant parameter suggestions as described herein) through machine learning.

The tensioner tool may also be configured to communicate with additional or alternative systems. In some embodiments, the tensioner tool may be configured to communicate with a surgical orientation system, e.g., the KneeAlign navigation system from ORTHALIGN, INC. Referring to FIG. 13, a tensioner tool 1305 is illustrated in use in conjunction with such a surgical orientation system 1310. As depicted, the surgical orientation system 1310 may comprise a jig, one or more rods, a cut guide, a computing device, a display, and one or more orientation sensors (e.g., accelerometers). In some embodiments, several components of the surgical orientation system may be integrated into a single unit and/or reversibly coupled to one another. The surgical orientation system 1310 may be utilized by a surgeon to define and record the positions of anatomical landmarks such as the mechanical axis of a bone by adjusting the orientation of the rods to align with the landmarks and recording the orientation of the rods by the orientation sensors. Subsequently, the cut guide may be positioned based on the anatomical landmark positions, and the computing device may provide varus/valgus and/or slope information (e.g., quantitative measurements) as feedback to the surgeon via the display. In some embodiments, the tensioner tool 1305 communicates distraction force and distraction distance measurements to the computing device of the surgical orientation system and the distraction information may be displayed to the surgeon. In some embodiments the tensioner tool 1305 may be utilized to collect distraction information prior to bone resection. Accordingly, the surgeon may utilize the distraction information to determine a suitable cut guide orientation, which may be precisely implemented using the surgical orientation system 1310. In some embodiments, the tensioner tool 1305 may be utilized to collect distraction information after at least one bone cut. Accordingly, the surgeon may utilize the distraction information to determine whether one or more additional cuts are required to achieve the desired post-operative joint characteristics, which may then be further carried out using the surgical orientation system 1310 to orient the cut guide as needed. In some embodiments, the tensioner tool 1305 may be utilized to collect distraction information after prosthesis implantation in order to validate the post-operative joint characteristics. While the surgical orientation system 1310 is depicted as affixed to a tibia, it is contemplated that the tensioner tool 1305 may be utilized with a surgical orientation system affixed to the femur in substantially the same manner as would be understood by one having an ordinary level of skill in the art. Further, the tensioner tool 1305 may be utilized with surgical orientation systems on additional joints such as a shoulder, an elbow, an ankle, a hip, or the like.

In additional embodiments, a computing device (e.g., a computing device 1105 as described with respect to FIG. 11 herein) may receive the distraction information and thereby suggest a suitable surgical plan (e.g., including a cut guide orientation) based on the distraction information. The surgeon may then precisely implement the surgical plan using the surgical orientation system 1310. Further, the distraction information and/or surgical plan information may be displayed to the surgeon on the display of the surgical orientation system 1310. Additional collected and/or calculated information as described herein may be displayed in the same manner. In other embodiments, orientation information may be transmitted by the surgical orientation system 1310 to an external computing device (e.g., computing device 1105 of the system 1100) such that it may be utilized in performing various calculations described herein and/or providing feedback to the surgeon.

In still additional embodiments, the orientation sensor of the surgical orientation system 1310 may be coupled to a bone of the joint (e.g., a tibia or a femur) and the joint may be placed in a pre-determined reference position. Subsequently, measurements from the orientation sensor may be utilized by a computing device (e.g. the computing device of surgical orientation system 1310 and/or computing device 1105) to determine a position of the joint along its range of motion. Tensioner tool 1305 may be utilized to collect distraction information and the computing device may associate the distraction information to the range of motion position. In some embodiments, the tensioner tool 1305 may collect distraction information at multiple discrete range of motion positions and the computing device associates each set of distraction information with the respective range of motion position. In some embodiments, an orientation sensor may be placed on each of multiple bones of the joint (e.g., the tibia and the femur) in order to provide more accurate range of motion information. In some embodiments, multiple orientation sensors may be placed on the same bone in order to provide more accurate range of motion information, e.g., in order to calculate and eliminate sensor drift.

It should also be understood that any designs, functions, or features shown or described with respect to one embodiment may be incorporated into other embodiments, For example, while