Soft tissue measurement and balancing systems and methods

Abstract

To provide systems and methods for joint replacement.SOLUTION: The systems and methods can include a surgical orientation device and a reference sensor device. The surgical orientation device and orthopedic fixtures can be used to locate the orientation of an axis in the body, to adjust an orientation of one or more cutting planes along a bony surface, to distract a joint, to measure an angle, to orient a cutting guide, to orient a resection guide, to resect the femur, or to otherwise assist in one or more orthopedic procedures.SELECTED DRAWING: Figure 13D

Description

[Technical Field]

[0001] Incorporation by reference of any priority application Any and all applications for which foreign or domestic priority is disclosed in an Application Data Sheet filed with this application, including U.S. Provisional Application No. 62 / 471,177, filed March 14, 2017, are hereby incorporated by reference in their entirety under 37 CFR § 1.57.

[0002] This application is directed to the field of joint replacement, and more particularly to surgical tools and methods for soft tissue balancing. [Background technology]

[0003] Joint replacement procedures, such as knee replacement procedures, are commonly used to replace a patient's joint with one or more artificial joint components. Such procedures often involve making cuts along one or more portions of the patient's bone using one or more systems of surgical tools and devices, including, but not limited to, cutting guides (e.g., cutting blocks) and surgical guides.

[0004] Current systems and methods often use expensive, complex, bulky, and / or heavy computer navigation systems that require one or more computers and three-dimensional imaging to track the spatial location and / or movement of surgical instruments or landmarks within the human body. These systems are generally used to assist a user in determining where in space an instrument or landmark is located and often require significant training, expense, and space.

[0005] Without these complex and expensive systems, simple methods, such as "eyeballing" the alignment of the rod with anatomical features, such as the bones of the leg, are used. These simple methods are not accurate enough to reliably align and position the implant components and the bones to which they are attached. Without precision and reliable positioning, suboptimal placement results, such as poor tissue balancing, can occur. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 8,998,910 [Patent Document 2] U.S. Patent No. 9,339,226 [Patent Document 3] U.S. Patent No. 8,118,815 [Patent Document 4] U.S. Patent Application Publication No. 2014 / 0052149 [Patent Document 5] U.S. Patent Application Publication No. 2016 / 0242934 [Patent Document 6] U.S. Patent Application No. 12 / 509,388 [Patent Document 7] U.S. Application No. 10 / 864085 [Patent Document 8] U.S. Application No. 11 / 182528 [Patent Document 9] U.S. Application No. 12 / 557051 [Patent Document 10] U.S. Application No. 12 / 509388 [Patent Document 11] U.S. Application No. 13 / 011815 [Patent Document 12] U.S. Application No. 13 / 115065 [Patent Document 13] U.S. Application No. 14 / 399046 [Patent Document 14] U.S. Application No. 14 / 401274 [Patent Document 15] U.S. Application No. 13 / 800620 [Patent Document 16] U.S. Application No. 14 / 643864 [Patent Document 17] U.S. Application No. 15 / 550564 Summary of the Invention [Problem to be solved by the invention]

[0007] Thus, there are no devices, systems, and methods that can be used to perform balancing, such as gap balancing and soft tissue balancing, during total knee arthroplasty (TKA). There is a need for a balancing and alignment system that can be integrated to perform both measurement-based resection and balancing. Described herein are devices, systems, and methods for guiding one or more cuts. [Means for solving the problem]

[0008] In some embodiments, an orthopedic system for orienting a cutting plane during a joint replacement procedure is provided. The system may include a tibial baseplate. The system may include a femoral baseplate. The system may include a surgical orientation device coupled to or configured to couple to at least one of the tibial baseplate and the femoral baseplate. The surgical orientation device may include a housing. The surgical orientation device may include an inertial sensor configured to monitor an orientation of the surgical orientation device in a three-dimensional reference coordinate system during distraction of the joint. The inertial sensor may be disposed on or within the housing. The surgical orientation device may include a user interface including a display screen configured to display measurements related to the distraction of the joint.

[0009] In some embodiments, the inertial sensor includes at least one gyroscope sensor, accelerometer sensor, tilt sensor, and / or other similar device or devices configured to measure and / or facilitate the determination of the orientation of the surgical orientation device. In some embodiments, the inertial sensor may be configured to provide measurements referenced to a reference point, line, plane, and / or zero gravity. In some embodiments, the inertial sensor includes a gyroscope sensor configured to detect angular position changes or an accelerometer configured to detect linear position changes. The system may include a drill guide coupled to the tibial baseplate. The system may include a reference sensor device including a camera. In some embodiments, the camera is oriented transverse to a longitudinal axis of a housing of the reference sensor device. In some embodiments, the camera is configured to capture an image of a linear scale of measurements related to knee distraction or otherwise make or confirm measurements related to knee distraction.

[0010] In some embodiments, an orthopedic orientation system for use in a joint procedure is provided. The system may include a tibial baseplate. The system may include a femoral baseplate. The system may include an adjustment device that allows at least one degree of freedom of the femoral baseplate relative to the tibial baseplate when the tibial baseplate is in a fixed position and orientation relative to the tibia. The system may include an adjustment device that allows at least one different additional degree of freedom of the femoral baseplate relative to the tibial baseplate when the tibial baseplate is in a fixed position and orientation relative to the tibia. The system may include a first orienting device configured to be coupled to the femoral baseplate. The first orienting device may include a sensor located within the housing configured to monitor the position and / or orientation of the first orienting device. The first orienting device may include a display configured to notify a user of the position and / or orientation of the first orienting device. The system may include a second orienting device configured to be coupled to the tibial baseplate.

[0011] In some embodiments, the sensor includes a gyroscope sensor to detect angular position changes and / or an accelerometer to detect linear position changes. Alternatively, or additionally, in other embodiments, the sensor may include a gravity sensor, a magnetic sensor, and / or other inertial sensor. In some embodiments, the system is configured to determine the orientation of a mechanical axis of the joint. In some embodiments, the at least one degree of freedom of the femoral baseplate relative to the tibial baseplate includes or is a translation. In some embodiments, the at least one additional degree of freedom of the femoral baseplate relative to the tibial baseplate includes or is a rotation.

[0012] In some embodiments, a method for performing an orthopedic surgical procedure is provided. The method may include coupling a first orienting device including a first inertial sensor to a portion of the knee joint. The method may include coupling a second orienting device including a second inertial sensor to a portion of the knee joint. The method may include collecting inertial sensor outputs from the first or second inertial sensor. The method may include distracting the knee joint. The method may include cutting the femur. The method may include determining, with the first and second orienting devices, a location of a mechanical axis of the leg or a mechanical axis of a bone, such as the femur or tibia, proximate the knee joint. The method may include displaying the inertial sensor outputs from the first or second inertial sensor. The method may include storing the inertial sensor outputs from the first or second inertial sensor. The method may include comparing an inertial sensor output at a first time point and an inertial sensor output at a second time point during the procedure. The method may include calculating, measuring, detecting, and / or collecting a distraction distance. In some embodiments, collecting the distraction distance includes capturing an image. In other embodiments, collecting includes the distraction distance. The method may include inserting one or more pins into the femur. The method may include attaching a cutting block to the one or more pins. The method may include coupling a drill guide to the knee joint.

[0013] In some embodiments, an orthopedic system for orienting a cutting plane during a joint replacement procedure is provided. The system may include a tibial component configured to couple to the tibia. The system may include a guide coupled to the tibial component, the guide configured to guide insertion of a pin into the femur. The system may include a surgical orientation device coupled to or configured to couple to at least one of the tibia or the femur. The surgical orientation device may include a housing. The surgical orientation device may include an inertial sensor configured to monitor an orientation of the surgical orientation device in a three-dimensional reference coordinate system during distraction of the joint. The surgical orientation device may include a user interface including a display screen configured to display measurements related to femoral rotation.

[0014] In some embodiments, an orthopedic system for orienting a cutting plane during a joint replacement procedure is provided. The system may include a tibial member. The system may include a femoral member. The system may include a surgical orientation device coupled to or configured to couple to at least one of the tibial member and the femoral member. The surgical orientation device may include a housing. The surgical orientation device may include an inertial sensor configured to monitor an orientation of the surgical orientation device in a three-dimensional reference coordinate system during distraction of the joint. The surgical orientation device may include a user interface including a display screen configured to display measurements related to the distraction of the joint.

[0015] The system may include a reference sensor device coupled to or configured to couple to at least one of the tibial member and the femoral member. In some embodiments, the surgical orientation device is configured to couple to the femoral member, and the reference sensor device is configured to couple to the tibial member. In some embodiments, the inertial sensor includes one or more gyroscope sensors, accelerometer sensors, tilt sensors, and / or other similar devices configured to measure and / or facilitate determining the orientation of the surgical orientation device. In some embodiments, the inertial sensor may be configured to provide measurements referenced to a reference point, a reference line, a reference plane, and / or zero gravity. In some embodiments, the inertial sensor includes a gyroscope sensor configured to detect angular position changes or an accelerometer configured to detect linear position changes. The system may include a drill guide coupled to the tibial member. The system may include a resection guide coupled to the tibial member. The system may include a reference sensor device including a camera. In some embodiments, the camera is oriented transverse to a longitudinal axis of a housing of the reference sensor device. In some embodiments, the camera is configured to capture images of measurements related to knee distraction. In some embodiments, the measurements include distance measurements corresponding to the distance between the tibia and the femur. In some embodiments, the measurements are set to correspond to measurement markings on the resection guide. In some embodiments, the measurements include distance measurements corresponding to gaps in extension. In some embodiments, the measurements include distance measurements that facilitate a posterior femoral cut. In some embodiments, the measurements include angle measurements corresponding to the angle between the tibia and the femur. In some embodiments, the measurements include angle measurements that facilitate soft tissue release. The system may include a movable interface that stabilizes the orthopedic system against the tibia. In some embodiments, the movable interface is configured to limit insertion of the tibial component within the joint space.The system may include a resection guide.

[0016] In some embodiments, an orthopedic orientation system for use in a joint procedure is provided. The system may include a tibial member. The system may include a femoral member. The system may include an adjustment device that allows at least one degree of freedom of the femoral member relative to the tibial member when the tibial member is in a fixed position and orientation relative to the tibia. In some embodiments, the system may include an adjustment device that allows at least one different additional degree of freedom of the femoral member relative to the tibial member when the tibial member is in a fixed position and orientation relative to the tibia. The system may include a first orienting device configured to be coupled to the femoral member. The first orienting device may include a sensor located within the housing configured to monitor the position and / or orientation of the first orienting device. The first orienting device may include a display configured to notify a user of the position and / or orientation of the first orienting device. The system may include a second orienting device configured to be coupled to the tibial member.

[0017] In some embodiments, the sensor includes a gyroscope sensor that detects angular position changes and / or an accelerometer that detects linear position changes. In some embodiments, the system is configured to determine an orientation of a mechanical axis of the joint. In some embodiments, the at least one degree of freedom of the femoral component relative to the tibial component is translational. In some embodiments, the at least one degree of freedom of the femoral component relative to the tibial component relates to distraction between the femur and the tibia. In some embodiments, the at least one additional degree of freedom of the femoral component relative to the tibial component is rotational. In some embodiments, the adjustment device includes a rounded portion of the post configured to move within a rounded guide portion. In some embodiments, the adjustment device includes a rack and a drive pinion. In some embodiments, the adjustment device includes a pawl and a ratchet. In some embodiments, the adjustment device is configured to apply a force between 150 N and 200 N. In some embodiments, the adjustment device includes a post including a portion having a round or circular cross-section. The system can include a bracket, wherein a longitudinal axis of the first orienting device is offset from a longitudinal axis of the second orienting device when the first orienting device is coupled to the bracket. The system can include a bracket that positions the first orienting device laterally from the second orienting device. In some embodiments, the second orienting device includes a camera configured to capture images of markings related to distraction distance. In some embodiments, the second orienting device includes a camera configured to capture images of a portion of the post of the adjustment device.

[0018] In some embodiments, a method of performing an orthopedic surgical procedure is provided. The method may include coupling a first orienting device comprising a first inertial sensor to a portion of a knee joint. The method may include coupling a second orienting device comprising a second inertial sensor to a portion of the knee joint. The method may include collecting inertial sensor outputs from the first inertial sensor or the second inertial sensor. The method may include distracting the knee joint. The method may include cutting a femur.

[0019] The method may include determining a location of a mechanical axis of a bone adjacent to the knee joint by a first or second orienting device. The method may include displaying an inertial sensor output from the first or second inertial sensor. The method may include storing the inertial sensor output from the first or second inertial sensor. The method may include comparing the inertial sensor output at a first time point and the inertial sensor output at a second time point during the procedure. The method may include collecting a distraction distance. In some embodiments, collecting the distraction distance includes capturing an image. The method may include inserting one or more pins into the femur. The method may include attaching a cutting block to the one or more pins. The method may include coupling a drill guide to the knee joint.

[0020] In some embodiments, a method of performing an orthopedic surgical procedure is provided. The method may include coupling a first orienting device including a first inertial sensor to at least one of a tibial member and a femoral member. The method may include coupling a second orienting device to at least one of the tibial member and the femoral member. The method may include inserting the tibial member and the femoral member into a joint space. The method may include distracting the knee joint. The method may include balancing soft tissue.

[0021] The method may include determining a location of the limb's mechanical axis with a first orienting device and a second orienting device. The method may include displaying the distraction distance on a display of the first orienting device. The method may include displaying the femoral angle on a display of the first orienting device.

[0022] The method may include storing a distraction distance in a memory of the first orienting device. The method may include storing a femoral angle in a memory of the first orienting device. The method may include comparing the distraction distance in extension to the distraction distance in flexion. The method may include collecting the distraction distance. In some embodiments, collecting the distraction distance includes capturing an image. In some embodiments, coupling the first orienting device to a portion of the knee joint includes coupling the first orienting device to a femoral component. In some embodiments, coupling the second orienting device to a portion of the knee joint includes coupling a second orienting device to a tibial component. In some embodiments, distracting the knee joint includes distracting the knee joint in extension. The method may include recording a gap distance in extension. The method may include distracting the knee joint in flexion after recording the gap distance in extension. The method may include aligning the gap distance in extension with a marking on the resection guide. The method may include performing a posterior femoral cut corresponding to the extension gap measurement. In some embodiments, distracting the knee includes distracting the knee in extension, and balancing the soft tissue includes balancing the soft tissue in extension. In some embodiments, balancing the soft tissue includes balancing the soft tissue only in extension. The method may include measuring femoral rotation angles in extension and flexion. The method may include recording femoral rotation angles in flexion.

[0023] In some embodiments, an orthopedic system for orienting a cutting plane during a joint replacement procedure is provided. The system may include a tibial member coupled to the tibia. The system may include a guide coupled to the femoral member. The system may include a surgical orientation device coupled to or configured to couple to at least one of the tibia or the femur. The surgical orientation device may include a housing. The surgical orientation device may include an inertial sensor configured to monitor an orientation of the surgical orientation device in a three-dimensional reference coordinate system during distraction of the joint. The surgical orientation device may include a user interface including a display screen configured to display measurements related to femoral rotation.

[0024] In some embodiments, the guide is configured to guide insertion of a pin into the femur.In some embodiments, the guide is configured to guide a posterior femoral cut.

[0025] These and other features, aspects, and advantages are described below with reference to the drawings, which are intended to illustrate, but not limit, the invention, in which corresponding features in like embodiments are designated by the same reference numerals throughout. [Brief explanation of the drawings]

[0026] [Figure 1A] FIG. 1 is an assembled view of the femoral preparation system. [Figure 1B] FIG. 1 is an assembled view of the femoral preparation system. [Figure 1C] FIG. 1 is an assembled view of the femoral preparation system. [Figure 2A] FIG. 1 is an assembled view of the tibial preparation system. [Figure 2B] FIG. 1 is an assembled view of the tibial preparation system. [Figure 2C] FIG. 1 is an assembled view of the tibial preparation system. [Figure 3A] FIG. 1 illustrates a femoral preparation and knee distraction system. [Figure 3B] FIG. 1 illustrates a femoral preparation and knee distraction system. [Figure 3C] FIG. 1 illustrates a femoral preparation and knee distraction system. [Figure 3D] FIG. 1 illustrates a femoral preparation and knee distraction system. [Figure 3E] FIG. 1 illustrates a femoral preparation and knee distraction system. [Figure 4A] FIG. 3B shows the tibial system of the femoral preparation and knee distraction system of FIG. 3A. [Figure 4B] FIG. 3B shows the tibial system of the femoral preparation and knee distraction system of FIG. 3A. [Figure 5A] FIG. 3B illustrates an actuation system of the femoral preparation and knee distraction system of FIG. 3A. [Figure 5B] FIG. 3B illustrates an actuation system of the femoral preparation and knee distraction system of FIG. 3A. [Figure 5C] FIG. 3B illustrates an actuation system of the femoral preparation and knee distraction system of FIG. 3A. [Figure 5D] FIG. 3B illustrates an actuation system of the femoral preparation and knee distraction system of FIG. 3A. [Figure 6A] FIG. 3B illustrates a reference sensor device of the femoral preparation and knee distraction system of FIG. 3A. [Figure 6B] FIG. 3B illustrates a reference sensor device of the femoral preparation and knee distraction system of FIG. 3A. [Figure 7A] FIG. 3B illustrates the femoral preparation and knee distraction system of FIG. 3A . [Figure 7B] FIG. 3B illustrates the femoral preparation and knee distraction system of FIG. 3A . [Figure 8A] FIG. 7C shows a drill guide coupled to the femoral system of FIGS. 7A-7B. [Figure 8B] FIG. 7C shows a drill guide coupled to the femoral system of FIGS. 7A-7B. [Figure 9A]FIG. 3B shows the femoral preparation and knee distraction system of FIG. 3A positioned within the joint space between the femur and tibia with the femur and tibia positioned in flexion. [Figure 9B] FIG. 9B illustrates a subsystem of the femoral preparation and knee distraction system of FIG. 9A including a reference device. [Figure 9C] FIG. 9B illustrates a subsystem of the femoral preparation and knee distraction system of FIG. 9A including a drill guide. [Figure 10] 10A-10C illustrate another embodiment of a femoral preparation and knee distraction system. [Figure 11A] 1A-1C illustrate a femoral preparation and knee distraction system for soft tissue balancing illustrating one method of using the femoral preparation and knee distraction system for soft tissue balancing. [Figure 11B] 1A-1C illustrate a femoral preparation and knee distraction system for soft tissue balancing illustrating one method of using the femoral preparation and knee distraction system for soft tissue balancing. [Figure 11C] 1A-1C illustrate a femoral preparation and knee distraction system for soft tissue balancing illustrating one method of using the femoral preparation and knee distraction system for soft tissue balancing. [Figure 11D] 1A-1C illustrate a femoral preparation and knee distraction system for soft tissue balancing illustrating one method of using the femoral preparation and knee distraction system for soft tissue balancing. [Figure 11E] 1A-1C illustrate a femoral preparation and knee distraction system for soft tissue balancing illustrating one method of using the femoral preparation and knee distraction system for soft tissue balancing. [Figure 11F] 1A-1C illustrate a femoral preparation and knee distraction system for soft tissue balancing illustrating one method of using the femoral preparation and knee distraction system for soft tissue balancing. [Figure 12A] FIG. 1 illustrates a femoral preparation and knee distraction system for soft tissue balancing. [Figure 12B]FIG. 1 illustrates a femoral preparation and knee distraction system for soft tissue balancing. [Figure 12C] FIG. 1 illustrates a femoral preparation and knee distraction system for soft tissue balancing. [Figure 12D] FIG. 1 illustrates a femoral preparation and knee distraction system for soft tissue balancing. [Figure 12E] FIG. 1 illustrates a femoral preparation and knee distraction system for soft tissue balancing. [Figure 13A] 10A-10C illustrate another embodiment of a femoral preparation and knee distraction system. [Figure 13B] 10A-10C illustrate another embodiment of a femoral preparation and knee distraction system. [Figure 13C] 10A-10C illustrate another embodiment of a femoral preparation and knee distraction system. [Figure 13D] 10A-10C illustrate another embodiment of a femoral preparation and knee distraction system. [Figure 13E] 10A-10C illustrate another embodiment of a femoral preparation and knee distraction system. [Figure 14A] FIG. 13B shows the tibial system of the femoral preparation and knee distraction system of FIG. 13A. [Figure 14B] FIG. 13B shows the tibial system of the femoral preparation and knee distraction system of FIG. 13A. [Figure 15A] FIG. 13B illustrates an actuation system of the femoral preparation and knee distraction system of FIG. 13A. [Figure 15B] FIG. 13B illustrates an actuation system of the femoral preparation and knee distraction system of FIG. 13A. [Figure 15C] FIG. 13B illustrates an actuation system of the femoral preparation and knee distraction system of FIG. 13A. [Figure 15D] FIG. 13B illustrates an actuation system of the femoral preparation and knee distraction system of FIG. 13A. [Figure 15E] FIG. 13B illustrates an actuation system of the femoral preparation and knee distraction system of FIG. 13A. [Figure 16A] FIG. 13B illustrates a movable interface of the femoral preparation and knee distraction system of FIG. 13A. [Figure 16B] FIG. 13B illustrates a movable interface lock of the femoral preparation and knee distraction system of FIG. 13A. [Figure 17A] FIG. 13B shows the femoral system of the femoral preparation and knee distraction system of FIG. 13A. [Figure 17B] FIG. 13B shows the femoral system of the femoral preparation and knee distraction system of FIG. 13A. [Figure 18A] FIG. 17C shows a resection guide coupled to the femoral system of FIGS. 17A-17B. [Figure 18B] FIG. 17C shows a resection guide coupled to the femoral system of FIGS. 17A-17B. [Figure 19A] FIG. 13B shows the femoral preparation and knee distraction system of FIG. 13A positioned within the joint space of a schematic knee joint positioned in flexion. [Figure 19B] FIG. 13B is a front view showing the femoral preparation and knee distraction system of FIG. 13A positioned within the joint space of a schematic knee joint positioned in flexion. [Figure 19C] 14A-14B show subsystems of the femoral preparation and knee distraction system of FIG. 13A including the tibial system of FIGS. 14A-14B. [Figure 19D] 14A-14B show subsystems of the femoral preparation and knee distraction system of FIG. 13A including the tibial system of FIGS. 14A-14B. [Figure 19E] FIG. 13B illustrates a subsystem of the femoral preparation and knee distraction system of FIG. 13A including a movable interface. [Figure 19F] FIG. 13B illustrates a subsystem of the femoral preparation and knee distraction system of FIG. 13A including a movable interface. [Figure 19G] FIG. 13B illustrates a subsystem of the femoral preparation and knee distraction system of FIG. 13A including a resection guide. [Figure 19H] FIG. 13B illustrates a subsystem of the femoral preparation and knee distraction system of FIG. 13A including a torque driver. [Figure 20A] FIG. 3B illustrates the femoral preparation and knee distraction system of FIG. 3A. [Figure 20B] FIG. 3B illustrates the femoral preparation and knee distraction system of FIG. 3A. [Figure 20C] FIG. 13B illustrates the femoral preparation and knee distraction system of FIG. 13A. [Figure 20D] FIG. 13B illustrates the femoral preparation and knee distraction system of FIG. 13A. DETAILED DESCRIPTION OF THE INVENTION

[0027] This application discloses systems and methods that can be used to measure how the soft tissues surrounding the knee interact with the bones of the knee during knee replacement procedures. These measurements allow surgeons to better understand the dynamics of the patient's knee anatomy, allowing them to better tailor bone preparation and application of prosthetic components to the patient and achieve superior results.

[0028] A. Alignment 1. Femur and tibial systems for performing measurement-based resections Before replacing a knee joint with a prosthetic component, surgical cuts, commonly referred to as resections, are typically made along one or more portions of both the proximal tibia and distal femur using one or more cutting tools. These cuts are made to prepare the tibia and femur for the prosthetic component. After these cuts are made, the prosthetic component can be attached and / or fixed to the tibia and femur.

[0029] The desired orientation and / or location of these cuts and prosthetic components can be determined preoperatively and may be based, for example, on the mechanical axis of an individual patient's leg. Once the desired locations of these cuts are determined preoperatively, the surgeon can accurately perform these cuts using the systems and methods described herein. While these systems and methods are described in the context of knee replacement procedures, these systems and / or their components, as well as these methods, can be used in other types of medical procedures as well, such as, but not limited to, hip replacement procedures. U.S. Patent Nos. 8,998,910, 9,339,226, and 8,118,815 disclose additional embodiments of tibia and femur preparation systems and are incorporated by reference in their entireties. U.S. Patent Application Publication Nos. 2014 / 0052149 and 2016 / 0242934 disclose additional features of surgical orientation and reference devices, as well as other components that can be incorporated into the systems described herein.

[0030] 1A and 1B, a femoral preparation system 10 can be used to remodel a natural femur by performing a distal femoral resection to allow a prosthetic component to be securely attached to the distal end of the femur. The femoral preparation system 10 can include, for example, a femoral jig assembly 12, a surgical orientation device 14, a reference device 16, a first coupling device 18, and a second coupling device 20. The first coupling device 18 can be used to attach the surgical orientation device 14 to the femoral jig assembly 12. The second coupling device 20 can be used to attach the reference sensor device 16 to the femoral jig assembly 12.

[0031] The surgical orientation device 14 can be used to measure and record the locations of anatomical landmarks used in total knee procedures, such as the location of the mechanical axis of the leg (and femur). The term "surgical orientation device" is a broad term and is intended to be given its ordinary and customary meaning to those skilled in the art (i.e., not limited to a specialized or specialized meaning), including, but not limited to, any device that provides orientation information or can be used to perform orientation calculations used in surgical or other procedures. As defined herein, the mechanical axis of the leg generally refers to a line extending from the center of rotation of the proximal head of the femur (e.g., the center of the femoral head), ideally through the approximate center of the knee, to the center or midpoint of the ankle. The mechanical axis of the femur is the same as the axis extending from the center of rotation of the proximal head of the femur through the center of the distal end of the femur (the center of the distal end of the femur is commonly referred to as the center of the intercondylar notch). Generally, ideal mechanical axes within a patient's body allow loads to be transferred from the center of the hip joint through the center of the knee to the center of the ankle. The surgical orientation device 14 can be used in conjunction with the reference devices 16 described herein to identify the spatial orientation of a mechanical axis. In certain techniques described herein, the surgical orientation device 14 and reference devices 16 can be used to identify one or more planes that intersect with a mechanical axis. The surgical orientation device 14 and reference devices 16 can also be used to verify the alignment of one or more orthopedic fixation tools or one or more cutting planes during an orthopedic surgical procedure. The surgical orientation device 14 and reference devices 16 described herein can each be used alone or in conjunction with other devices, components, and / or systems.

[0032] The surgical orientation device 14 may include a display 26. The display 26 may be sized so that a user can easily read numbers, letters, and / or symbols displayed on the display screen while performing a medical procedure. The surgical orientation device 14 may further include at least one user input device 28. The at least one user input device 28 may include a plurality of buttons located proximate to the display 26. The buttons may be activated, for example, by a finger, a hand, and / or an instrument, to select one or more operational modes of the device 14, as described further below. The surgical orientation device 14 includes a user interface with which a clinician can interact during a procedure. The surgical orientation device 14 includes an electrical system. The electrical system may include one or more mechanisms, such as one or more sensors, an electronic control unit in communication with the one or more sensors, one or more visual alignment indicators, a power supply, a display 26, memory, one or more user input devices 28, one or more processors, other board configurations representing program logic, data, and instructions, controller circuitry, processor circuitry, processors, single-chip or multi-chip general-purpose microprocessors, digital signal processors, embedded microprocessors, microcontrollers, other output devices, and / or one or more input / output (I / O) ports. In certain embodiments, the electronic control unit may be configured to convert electronic data from a machine-readable format to a human-readable format for presentation on the display 26. The electronic control unit may communicate with internal and / or external memory to retrieve and / or store data and / or program instructions for the software and / or hardware. The internal and external memory may include random access memory (RAM), such as static RAM, for temporarily storing information, and / or read-only memory (ROM), such as flash memory, for more permanently storing information.Generally, the sensor(s) can be configured to provide continuous, real-time data to the surgical orienting device 14. The electronic control unit can be configured to receive the real-time data from the sensor(s) and use this sensor data to determine, estimate, and / or calculate the orientation or position of the surgical orienting device 14. This orientation information can be used to provide feedback to a user during the performance of a surgical procedure, such as a total knee replacement, as described in further detail herein.

[0033] In some embodiments, the electronics may include a display in addition to or instead of the surgical orienting device 14. The electronics may include one or more handheld devices, such as a computer, a desktop computer, a laptop computer, or a tablet computer such as an iPad®. In some embodiments, the display is located within the surgical field. In some embodiments, the display is located outside the surgical field. In some embodiments, the reference sensor device 16 may include a display. In some embodiments, the electronics may include at least one user input device 28 in addition to or instead of the surgical orienting device 14. The user input device 28 may be activated, for example, by a finger, a hand, and / or an instrument, to select one or more operating modes of one or more electronic devices of a system that includes the surgical orienting device 14 and / or the reference sensor device 16. The electronics may include software and / or hardware for the systems described herein. The electronics may include external memory for the systems described herein. The surgical orienting device 14 and / or the reference sensor device 16 may be connected to the Internet. The surgical orienting device 14 and / or the reference sensor device 16 may transmit information to or receive information from the Internet. The surgical orientation device 14 and / or the reference sensor device 16 may also be connected to the cloud. The surgical orientation device 14 and / or the reference sensor device 16 may also transmit information to or receive information from the cloud.

[0034] In some configurations, the one or more sensors may include at least one orientation sensor configured to provide real-time data related to the movement, orientation, and / or position of the surgical orienting device 14 to the electronic control unit. For example, the sensor module may include at least one gyroscope sensor, acceleration sensor, tilt sensor, magnetometer, and / or one or more other similar devices configured to measure and / or facilitate determining the orientation of the surgical orienting device 14. In some embodiments, the sensors may be configured to provide measurements relative to reference point(s), reference line(s), reference plane(s), and / or gravitational zero. As referred to herein, "gravitational zero" generally refers to an orientation in which the sensor's axis is orthogonal to gravity, thereby exhibiting no angular offset, such as tilt, pitch, roll, or yaw, relative to the gravity vector. In other embodiments, the sensor(s) may be configured to provide measurements used in dead reckoning or inertial navigation systems.

[0035] In various embodiments, the sensor(s) include one or more accelerometers that measure static acceleration due to gravity of the surgical orienting device 14. For example, the accelerometer(s) can be used as tilt sensors to detect rotation about one or more axes of the surgical orienting device 14. The one or more accelerometers can include dual-axis accelerometers (capable of measuring rotation about two axes of rotation) or triaxial accelerometers (capable of measuring rotation about three axes of rotation). Changes in orientation about the accelerometer axes can be determined relative to zero gravity and / or a reference plane that is registered during tibia or femur preparation as described herein.

[0036] In certain embodiments, a multi-axis accelerometer (such as the Analog Devices ADXL203CE MEMS accelerometer or the ST Microelectronics LIS331DLH accelerometer) detects changes in orientation about two axes of rotation. For example, the multi-axis accelerometer can detect changes in the angular position of the surgical orienting device 14 from the horizontal plane (e.g., forward / backward rotation) and changes in the angular position of the surgical orienting device 14 from the vertical plane (e.g., roll rotation). The changes in the angular position of the surgical orienting device 14 from the horizontal and vertical planes (measured by the sensor) can also be used to determine changes in the medial / lateral orientation of the surgical orienting device 14 (e.g., varus / valgus rotation).

[0037] In some configurations, the sensors include at least one single-axis or multi-axis gyroscope sensor and at least one single-axis or multi-axis accelerometer sensor. For example, the sensors may include a three-axis gyroscope sensor (or three gyroscope sensors) and a three-axis accelerometer (or three accelerometer sensors) to provide position and orientation measurements for all six degrees of freedom of the surgical orienting device 14. In some embodiments, the sensors comprise an inertial navigation system or dead reckoning system that continuously calculates the position, orientation, and direction of the surgical orienting device 14 without the need for an external reference.

[0038] In one embodiment, the surgical orientation system includes a surgical orienting device 14 and a reference device 16. The reference device 16 can include any of the features of the surgical orienting device 14. The surgical orienting device 14 and / or the reference device 16, in one embodiment, include one or more sensors that can comprise an inertial measurement unit (IMU). In particular, the IMU includes a first sensor for determining acceleration and a second sensor for determining gyroscopic position. As described herein, the first sensor can be an accelerometer, and the second sensor can be a gyroscopic sensor. The reference device 16 also includes a transmitter that transmits data from these sensors to the electrical system of the surgical orienting device 14. Information received from the reference device 16 can be sent to an input port, or the electronic control unit of the surgical orienting device 14 itself can receive this information wirelessly. Information from the reference device 16 may correspond, for example, to the position and / or orientation of the reference device 16, which the surgical orientation device 14 may use to determine the overall relative or global position and / or orientation of the surgical orientation device 14.

[0039] The reference sensor device 16 can be used to measure and record the locations of anatomical landmarks used in total knee procedures, such as the location of the mechanical axis of the leg (and femur). "Reference sensor device" is a broad term of meaning and shall be given its ordinary and customary meaning to those skilled in the art (i.e., not limited to a specific or specialized meaning), including, but not limited to, any device that references another device and / or provides orientation information or performs calculations in the same or similar manner as the surgical orientation device 14 described above. In some embodiments, the reference sensor device 16 may include the same or similar components as the surgical orientation device 14 described above. Further description of reference sensors can be found, for example, but not limited to, U.S. Patent Application No. 12 / 509,388, paragraphs

[0176] -

[0178] , which are incorporated herein by reference. Further details of the systems, devices, sensors, and methods can be found in U.S. application Ser. Nos. 10 / 864,085, filed June 9, 2004, 11 / 182,528, filed July 15, 2009, 12 / 557,051, filed September 10, 2009, 12 / 509,388, filed July 24, 2009, and 12 / 509,388, filed January 21, 2011, all of which are incorporated by reference in their entireties for all purposes. and US Patent No. 13 / 011815 filed May 24, 2011, US Patent No. 13 / 115065 filed November 5, 2014, US Patent No. 14 / 399046 filed November 14, 2014, US Patent No. 14 / 401274 filed November 14, 2014, US Patent No. 13 / 800620 filed March 13, 2013, US Patent No. 14 / 643864 filed March 10, 2015, and US Patent No. 15 / 550564 filed August 11, 2017.

[0040] 1C, the femoral jig assembly 12 may include an orthopedic assembly for preparing the femur during a total knee replacement procedure. In a preferred configuration, the femoral jig assembly 12 may include a distal guide assembly 88, a microblock assembly 90, a cutting block 92, an articulating arm 98, and a midline pin 102. In preparing the distal femoral resection, the method may begin with identifying a distal point that intersects with the mechanical axis of the femur. The method may include placing the femoral jig assembly 12 approximately in the center of the intercondylar notch via the midline pin 102, which positions the femoral jig assembly 12 approximately in the center of the distal end of the femur.

[0041] The reference sensor device 16 and / or the orienting device 14 can be used to determine the relative coordinates of a central pivot point on the femur. By determining the coordinates of the pivot point of the femoral head, the reference sensor device 16 and / or the surgical orienting device 14 can calculate the location and / or orientation of a mechanical axis extending within the femur.

[0042] To determine the coordinate of the femoral head pivot point (i.e., the pivot point of the mechanical axis), the leg may be moved (e.g., rocked). For example, the leg may be moved in several different directions and / or in several different planes with the reference sensor device 16 and / or surgical orienting device 14 attached. The reference sensor device 16 and / or surgical orienting device 14 may take readings such as angular velocity and acceleration of the femur 140 (the "surgical orienting device 14 and / or reference device 16 data") until the location and / or orientation of the leg and femur 140 mechanical axis (the "femur mechanical axis") is determined. In an embodiment using one or more multi-axis (e.g., two-axis) accelerometers and gyroscopes, the surgical orienting device 14 and / or reference device 16 data for each movement of the femur 140 may be numerically integrated over time to obtain a trajectory of position and velocity points (one point for each IMU data point). The IMU data can be integrated without imposing any planar trajectory constraints on the movement of the femur 140.

[0043] The accelerations and angular velocities sensed by the reference sensor device 16 and / or the surgical orienting device 14 during leg movement can be processed while the leg is moving about its pivot point. The reference sensor device 16 and / or the surgical orienting device 14 can provide an output vector representing the center of rotation of the reference sensor device 16 and / or the surgical orienting device 14 relative to the inertial sensor axis.

[0044] In some embodiments, prior to determining the location and / or orientation of the center of rotation of the mechanical axis, error correction techniques can be used to remove bias in the surgical orienting device 14 and / or the reference sensor device 16. For example, the error correction techniques may include assessing 1) static bias, 2) gyroscope bias, and 3) accelerometer bias in the reference sensor device 16 and / or the surgical orienting device 14.

[0045] At least one purpose of the surgical orientation device 14 and / or reference device 16 and various systems described herein is to provide a surgeon with guidance on how to position a cutting block on a bone to achieve a cutting plane that is orthogonal to the bone's load-bearing axis (or, if desired, a plane that deviates from that orthogonal plane by some distance). A jig, such as the one described above, can be fixed to the bone to be cut, and the reference sensor device 16 and surgical orientation device 14 can be attached to the jig (one device attached to a fixed portion of the jig to serve as a reference for bone orientation, and the other device attached to an articulating arm of the jig to provide the surgeon with a means to find and set the desired cutting plane). The articulating arm of the jig can be constrained to move in only two directions, e.g., pitch and yaw (but not rotation). These two axes define a plane that can be adjusted to guide the placement of the cutting block, which in turn guides the saw to cut the bone in that plane.

[0046] Once the bias is removed and the reference sensor device 16 and / or surgical orientation device 14 have calculated the mechanical axis pivot point and located the mechanical axis as described above, the user can begin adjusting and orienting the cutting block 92 relative to the location of the mechanical axis. For example, the surgical orientation device 14 can display the varus / valgus and flexion / extension angular adjustments required to bring the surgical orientation device 14 (and femoral jig assembly 12) into neutral alignment with the mechanical axis through the femoral head.

[0047] In some embodiments, the reference sensor device 16 may be advantageously capable of tracking the relative position of a leg, such as the femur, such that the reference sensor device 16 may allow the procedure to proceed without immobilizing the operative leg. For example, at least one of the reference sensor device 16 and the surgical orientation device 14 may be in communication with the other such that any relative movement of one of the devices is tracked by the other, and the resulting overall orientation of the reference sensor device 16 and / or the surgical orientation device 14 may be displayed on the display 26 of the surgical orientation device 14. In some embodiments, the reference sensor device 16 may be capable of tracking the movement of the leg (i.e., the femur or the tibia), such that the overall orientation of the surgical orientation device 14 remains accurate even if the leg moves during the procedure.

[0048] 2A, a tibial preparation system 210 may be used to modify the natural tibia with a proximal tibial resection to allow a prosthetic component to be securely attached to the proximal end of the tibia. The tibial preparation system 210 may include, for example, a tibial jig assembly 212, a landmark acquisition assembly 214, a surgical orientation device 14, and a reference sensor device 16.

[0049] The tibia jig assembly 212 may include an orthopedic assembly for use in preparing the tibia for a prosthetic component, particularly for making angular adjustments relative to anatomical features.

[0050] In a preferred configuration, the tibial jig assembly 212 may include components to adjust the posterior / anterior slope of the surgical orientation device 14 and / or the cutting block. In a preferred configuration, the tibial jig assembly 212 may also include components to adjust the varus / valgus slope of the cutting block.

[0051] 2A illustrates various features of the landmark acquisition assembly 214. The landmark acquisition assembly 214 may comprise structures configured to contact and / or acquire information about anatomical landmarks of the human body. The landmark acquisition assembly 214 may be attached to or form part of the tibia jig assembly 212.

[0052] 2A , the probe assembly 202 may include an elongated member 220. The probe assembly 202 may include a probe member 206 located at at least one end of the elongated member 220. The probe member 206 may be configured to contact an anatomical landmark, such as the malleolus of a patient's ankle. The elongated member 220 may further include a series of markings 227 indicating distance and / or length. These markings may be used, for example, to measure the AP offset of the probe member 206.

[0053] The midline reference probe assembly 226 can be positioned at a suitable anatomical location on the proximal tibia, such as a point immediately behind the attachment of the anterior cruciate ligament (ACL), or another suitable anatomical landmark. For example, the tip 241 of the midline reference probe assembly 226 may be located above the attachment of the anterior cruciate ligament at the knee and / or above a soft point on the top of the tibia, commonly referred to as the A / P point of the mechanical axis. This A / P point is generally located along the tibial osteophyte at the top of the tibia, marking the location of a point along the mechanical axis of the leg. A distance indicator on the top surface of the midline reference probe assembly 226 can be identified (e.g., via markings 240), and a corresponding A / P offset position can be set in the landmark acquisition assembly 214 (e.g., via markings 227 described above).

[0054] FIG. 2A shows the tibia jig assembly 212 in a fully assembled state, with the reference sensor device 16 coupled to the reference sensor device interface 228 and the surgical orienting device 14 coupled to the orienting device interface 230.

[0055] Referring to FIG. 2B , the method may further include acquiring landmarks that determine the location of the mechanical axis through the tibia. For example, the landmarks may be acquired by first engaging the probe member 206 of the probe assembly 202 with the medial malleolus and then with the lateral malleolus (or vice versa). FIG. 2B illustrates the acquisition of one malleolus. The acquisition of the other malleolus may be similarly performed by pivoting one or more portions of the tibial jig assembly 212 so that the probe member 206 contacts the opposite side of the leg. The surgical orientation device 14 may then determine the location of the mechanical axis, for example, by identifying sagittal and coronal planes that extend through the mechanical axis. In some embodiments, the surgical orientation device may also calculate the location of the mechanical axis by assuming that the mechanical axis extends from the point where the midline reference probe assembly 226 contacts the proximal tibia through a midpoint between the two malleolus points where the probe members 206 contact on either side of the leg, or any other suitable point.

[0056] In some embodiments, the user can activate the surgical orienting device 14 during each landmark acquisition, such as by pressing one of the user input devices 28 on the surgical orienting device 14. Once activated, the surgical orienting device 14 can register (e.g., record) the orientation of the surgical orienting device 14 as a reference position (e.g., a first reference position). For example, the surgical orienting device 14 can register and / or calculate the current orientation of the surgical orienting device 14 based on data collected from a sensor(s) within the surgical orienting device 14. The orientation of the surgical orienting device 14 at the first reference position can be used to identify and register the orientation of a coronal plane containing the mechanical axis of the leg and can also determine a first reference point for identifying the location and / or orientation of a sagittal plane containing this same mechanical axis.

[0057] The user can then swing the probe member 206 to the opposite side of the leg (e.g., the medial side) so that the probe member 206 is positioned proximate to the other malleolus. During each landmark acquisition, the user can palpate the ankle. Once the other (e.g., medial) malleolus is located, the user can press one of the user input devices 28 on the surgical orientation device 14 to cause the surgical orientation device 14 to determine its orientation at the second reference position. For example, the surgical orientation device 14 can register and / or calculate its current orientation based on data collected from a sensor(s) within the surgical orientation device 14.

[0058] The orientation of the surgical orientation device 14 at the second reference position can also be used to identify the orientation of a coronal plane extending through the tibia that contains the mechanical axis of the leg, and / or can be used to identify a second reference point for identifying the location and / or orientation of a sagittal plane that contains the same mechanical axis.

[0059] When determining the first and second reference positions using surgical orientation device 14, the output of the sensor(s) of surgical orientation device 14 can be monitored in a manner that minimizes erroneous readings. For example, transition phases in the sensor output can be eliminated to provide an accurate estimate of a given anatomical landmark.

[0060] Once information about both the first and second reference positions has been obtained and registered with the surgical orientation device 14, the surgical orientation device 14 can determine (e.g., calculate) the location of a desired plane between the lateral and medial malleolus. This desired plane may correspond to a sagittal plane that includes the mechanical axis. The desired plane may vary depending on factors such as the patient's unique anatomy and the surgeon's training and experience. For example, the desired plane may be located midway between the lateral and medial malleolus, 55% from the lateral malleolus toward the medial malleolus, or some other predetermined location.

[0061] A user can use one or more user input devices 28 to instruct surgical orientation device 14 to calculate the location and / or orientation of the sagittal plane. Once surgical orientation device 14 has calculated where the sagittal plane is, surgical orientation device 14 can provide location feedback to the user, such as in the form of one or more visual signals on display 26, to indicate that the location of the sagittal plane has been calculated.

[0062] Referring to FIG. 2C , once the mechanical axis is identified, the tibial cutting block assembly 224 can be utilized. The cutting block assembly 224 can be positioned so that the cutting block 232 is spaced away from the anterior surface of the tibia. Using the surgical orientation device 14 and the tibial jig assembly 212, the cutting block 232 can be adjusted to obtain the desired orientation for resecting the upper portion of the tibia. For example, the posterior slope assembly 216 and the varus / valgus assembly can each be independently adjusted to change the angle of the cutting block 232 and subsequently the angle of the intended resection. During this adjustment, the surgical orientation device 14 can provide one or more readings on its display 26 indicating whether the surgical orientation device 14 (and cutting block 232) is aligned with the sagittal and / or coronal planes that contain the mechanical axis.

[0063] Once the cutting block is in place, the cutting block 232 can be attached to the anterior surface of the proximal portion of the tibia with a number of pins. The surgical orientation device 14 can be removed, as can the tibia jig assembly 212. After the cutting block 232 is attached to the tibia, the proximal portion of the tibia can be resected.

[0064] B. Femoral Preparation and Knee Distraction System 3A-3E illustrate an embodiment of a resection plane orientation system 310. The system 310 can be configured to distract the knee joint during a knee replacement procedure. The system 310 can be configured to distract the knee joint during a knee replacement procedure and measure the natural or preoperative rotation of the femur relative to the tibial resection. Additionally or alternatively, the system 310 can be configured to facilitate attachment of a drill guide to the distal femur to align a location hole in the distal femur for an implant's "universal" cutting block. When the knee is fully distracted, the system 310 provides information about how to resect the femur to aid in balancing the soft tissue and / or ligaments within the knee joint. The system 310 can include a surgical orientation device 14 and a reference sensor device 16. As described herein, the surgical orientation device 14 and the reference sensor device 16 can be used for alignment, distraction, or both alignment and distraction. System 310 may further include one or both of a tibial system 312 and a femoral system 352, as described herein. Although tibial system 312 and femoral system 352 are described as separate subsystems, system 310 may also be considered a single instrument. In some embodiments, system 310 may be implemented as a pre-connected, e.g., non-separable, assembly on a surgical kit.

[0065] 1. Tibial System 4A and 4B illustrate a tibial system 312. The tibial system 312 may include a tibial baseplate 314. The tibial baseplate 314 may be considered a reference mechanism. The tibial baseplate 314 may be configured to be positioned on the tibial plateau or on a resected surface formed on the proximal tibia. The tibial baseplate 314 may include a planar member. The tibial baseplate 314 may include a first surface 318 configured to align with a flat surface of the resected tibia. The tibial baseplate 314 may include a second surface 316 opposite the first surface 318 positioned on the femoral side. The tibial system 312 may include an extension member 320. The tibial system 312 may include a mounting block 322. The extension member 320 may extend between the mounting block 322 and the tibial baseplate 314. The extension member 320 can position the mounting block 322 away from the knee joint, for example, anteriorly.

[0066] In some embodiments, the extension member 320 can be integrally or monolithically formed with the tibial baseplate 314. In some embodiments, the extension member 320 and the tibial baseplate 314 comprise a unitary structure. In some embodiments, the extension member 320 can be integrally or monolithically formed with the mounting block 322. In some embodiments, the extension member 320 and the mounting block 322 comprise a unitary structure. In some embodiments, one or more of the extension member 320, the tibial baseplate 314, and the mounting block 322 are separate components.

[0067] The mounting block 322 may include a first coupler 324. The first coupler 324 may be configured to couple with the surgical orientation device 14 and / or the reference sensor device 16. The first coupler 324 may include an elongated post. In some embodiments, the first coupler 324 may have a regular shape (e.g., cylindrical). In some embodiments, the first coupler 324 has an irregular shape (e.g., triangular, teardrop-shaped, oval, rectangular). The irregular shape may facilitate alignment of the reference sensor device 16 in an orientation relative to the mounting block 322. In the illustrated embodiment, the first coupler 324 is positioned on the bottom surface of the mounting block 322. In the illustrated embodiment, the first coupler 324 is positioned orthogonal to the tibial resection. In some methods of use, the tibial resection is the reference feature. In the illustrated embodiment, the first coupler 324 is positioned so that the longitudinal axis of the reference sensor device 16 is aligned with the longitudinal axis of the tibia, which may be perpendicular to the tibial resection. In the illustrated embodiment, the first coupler 324 is positioned so that the longitudinal axis of the reference sensor device 16 is aligned with a mechanical axis associated with the knee joint, such as the mechanical axis of the tibia or leg.

[0068] In some embodiments, the mounting block 322 may include one or more additional couplers 326. The one or more additional couplers 326 may be the same as the first coupler 324. The one or more additional couplers 326 may be positioned on any surface of the mounting block 322. The additional coupler 326 may be positioned so that the longitudinal axis of the reference sensor device 16 is perpendicular to the longitudinal axis of the tibia. See FIG. 11B . The additional coupler 326 may also be positioned so that the longitudinal axis of the reference sensor device 16 is perpendicular to the mechanical axis. The additional coupler 326 may also be positioned so that the longitudinal axis of the reference sensor device 16 is perpendicular to the tibial resection plane. The additional coupler 326 may also be positioned at any known angle relative to the tibial resection plane. One or more of the couplers 324, 326 may be parallel to the tibial resection plane. The coupler 324 may also position the reference sensor 16 so that it is perpendicular to the tibial resection plane. The coupler 326 may also position the reference sensor 16 so that it is parallel to the tibial resection plane. The orientation of the reference sensor 16 relative to the tibial resection surface may be an input to the system 310. A user may also input the orientation of the reference sensor 16 as an input to the surgical orientation device 14. The couplers 324, 326 may also work with different software versions corresponding to their configuration. In some embodiments, the coupler 326 may be provided without the coupler 324.

[0069] The mounting block 322 may include a guide portion 330. In some embodiments, the guide portion 330 may extend into the mounting block 322. In some embodiments, the guide portion 330 is a slot or other opening. The guide portion 330 may guide a post 332 through the mounting block 322. The guide portion 330 may be configured to allow the post 332 to slide within the mounting block 322. The post 332 may provide movement of the femoral system 352 relative to the tibial system 312.

[0070] The system 310 may include an adjustment device 336. The adjustment device 336 can be positioned anywhere within the system 310. In the illustrated embodiment, the tibial system 312 may include the adjustment device 336. The adjustment device 336 is configured to translate the post 332 relative to the mounting block 322. The adjustment device 336 may include a gear. The post 332 may include a corresponding gear, screw, ramp, rack, etc. The adjustment device 336 may include a pinion. The post 332 may include a corresponding rack. In the illustrated embodiment, the adjustment device 336 is a drive pinion. The adjustment device 336 may include any mechanical mechanism configured to cause translation of the post 332. In some embodiments, the adjustment device 336 can be rotated to cause translation of the post 332. In some embodiments, the adjustment device 336 can also be translated to cause translation of the post 332. Other adjustment devices are also contemplated. The adjustment device 336 may include an interface 338. The interface 338 may allow a user to move the adjustment device 336. The interface 338 may include a knob. The interface 338 may include a recess. In the illustrated embodiment, the interface 338 is a hexagonal recess. The interface 338 may allow a user to rotate the adjustment device 336.

[0071] FIGS. 4A and 4B illustrate the tibial system 312 and the post 332. FIGS. 5A-5D illustrate the internal components of the tibial system 312 and the post 332. In some embodiments, the post 332 is substantially straight along its length. The post 332 can be translated by an adjustment device 336. The post 332 can include a rack 334. The rack 334 can extend along an edge of the post 332. The rack 334 can extend along the entire length of the post 332 or along a portion thereof. The adjustment device 336 can be a drive pinion. The adjustment device 336 can interact with the rack 334 such that rotation of the adjustment device 336 causes translation of the post 332. The adjustment device 336 can rotate freely within the mounting block 322. The adjustment device 336 can be prevented from translating within the mounting block 322.

[0072] The post 332 may include one or more markings 340. The markings 340 may indicate the length or extent of the post 332. The markings 340 may indicate the distraction distance of the system 310, as described herein. The markings 340 may include scales. The markings 340 may include machine-readable scales. The markings 340 may include user-visible scales. User-visible scales are shown in FIGS. 4B, 5B, and 5D. The scales extend beyond the mounting block 322. The user can look at the scale to indicate the distraction distance. The mounting block 322 may include indicia such as an arrow to direct the user's eye to the measurement. As the post 332 translates upward, the number of indicia visible to the user increases (e.g., 8 mm, 9 mm, 10 mm, etc.). The distraction distance may correspond to the measurement visible to the user on the scale. In some embodiments, the marking 340 may range from about 0.5 inches to 3 inches, about 0-5 inches, etc. The marking 340 may be printed on the post 332. In some embodiments, the marking 340 may be on a separate component, such as an inlay 342. The inlay 342 may be received within a portion of the post 332. In some embodiments, the inlay 342 is spaced a distance from the distal end of the post 332. In some embodiments, the inlay 342 is spaced a distance from the proximal end of the post 332.

[0073] In some embodiments, the marking 340 may include a machine-readable feature disposed on the surface of the post 332. In some embodiments, the machine-readable feature includes a binary code, a two-dimensional bar code, or other symbol. In some embodiments, the reference sensor device 16 shown in FIG. 3A is configured to be positioned to read the marking 340. The reference sensor device 16 may be adapted to optically detect the machine-readable feature of the marking 340. The marking 340 may include a binary code or other symbol that can be read by the reference sensor device 16. The marking 340 may include a scale. In some embodiments, the scale can be read by the reference sensor device 16. In some embodiments, the scale is obscured from the user. The distance indicated on the marking 340 can be input into the system 310 in any manner described herein (e.g., manually or by sensing).

[0074] 6A and 6B illustrate embodiments of the reference sensor device 16. The reference sensor device 16 may include a camera 344. In some embodiments, the camera 344 and the reference sensor device 16 are separate components. In some embodiments, the camera 344 and the reference sensor device 16 are coupled together. In some embodiments, the camera 344 is integral with the reference sensor device 16. In some embodiments, the camera 344 is a separate component from the reference sensor device 16. The reference sensor device 16 may include a window 346 through which the camera 344 can view. The camera 344 can capture an image of the marking 340. In some embodiments, the camera 344 and / or the reference sensor device 16 may include a light that illuminates the marking 340. In some embodiments, the light is an LED. In some embodiments, the mounting block 322 includes a window that allows the camera 344 to capture an image. In other embodiments, the camera 344 captures an image of the marking 340 that extends beyond the mounting block 322.

[0075] The image of the marking 340 allows the translational position of the post 332 to be accurately determined. The marking 340 can be positioned on the post 332 so as to be proximate to the camera 344 when the reference sensor device 16 is coupled to the mounting block 322. The camera 344 can be fixed relative to the mounting block 322 when the camera 344 captures the image. The camera 344 can be oriented to face the marking 340. The camera 344 can capture an image of the marking 340. The image can correspond to a distraction distance, which changes as the post 332 slides within the mounting block 322.

[0076] In some embodiments, camera 344 may capture an image of the binary code of markings 340. In some embodiments, camera 344 may capture an image of a scale or other markings 340. The distraction distance may be based on an image of markings 340 captured by camera 344, as described herein. In some embodiments, this image may be captured automatically by camera 344. In some embodiments, this image may be captured by camera 344 when prompted by a user (e.g., by interacting with user input device 28).

[0077] In some embodiments, the system 310 can measure the distraction distance using one or more sensors. The reference sensor device 16 can include one or more inertial sensors capable of determining distance measurements. The surgical orienting device 14 can include one or more inertial sensors capable of determining distance measurements. In some embodiments, the system 310 can measure a reference distance from the surgical orienting device 14 and / or the reference sensor device 16. In some embodiments, the system 310 can record or store a reference distance from the surgical orienting device 14 and / or the reference sensor device 16. During distraction, the system 310 can measure the change in distance from the reference distance. In addition to or instead of the camera 344 reading the markings 340, the output of the inertial sensor can also be used to measure the distance. The system 310 can perform one or more calculations to determine the distraction distance from the inertial sensor output.

[0078] 4A-5D , the system 310 may include a catch 348. The catch 348 may be positioned anywhere within the system 310. In the illustrated embodiment, the tibial system 312 may include the catch 348. The catch 348 is configured to maintain the position of the post 332 relative to the mounting block 322. The catch 348 may include a gear. The catch 348 may include a detent. The catch 348 may include a pin. The post 332 may include a corresponding gear, screw, ramp, rack, or ratchet. The catch 348 may include any mechanical mechanism configured to limit movement of the post 332. In some embodiments, the catch 348 may include any mechanical mechanism configured to limit movement of the post 332 in one direction.

[0079] The post 332 may include a ratchet 350. The ratchet 350 may extend along the entire length of the post 332, or may extend along a portion thereof. A catch 348 may interact with the ratchet 350 to limit translation of the post 332. In some embodiments, when the catch 348 is engaged with the ratchet 350, translation of the post 332 may be limited in both directions. When the catch 348 is disengaged from the ratchet 350, the post 332 may translate in both directions via the adjustment device 336. In some embodiments, the catch 348 may be engaged or disengaged by a user interacting with an interface, such as by turning a knob. In some embodiments, the catch 348 limits movement in only one direction. When the catch 348 is engaged with the ratchet 350, translation of the post 332 may be limited to movement in one direction. In some embodiments, the one-way nature of the catch 348 increases the distraction distance. When the catch 348 is disengaged from the ratchet 350 , the post 332 can translate in both directions via the adjustment device 336 .

[0080] In some embodiments, catch 348 may include a spring. In some embodiments, catch 348 may be biased toward engagement with ratchet 350. A user interacts with an interface to move catch 348 away from ratchet 350. In some embodiments, catch 348 may be biased toward disengagement from ratchet 350. A user interacts with an interface to move catch 348 toward ratchet 350. Other configurations are contemplated.

[0081] In some embodiments, the movement of the post 332 can be tracked or monitored. For example, the system 310 can provide audible and / or visual feedback to the user to indicate the degree or range that the post 332 has moved relative to an initial starting position. In some embodiments, the feedback system can be coupled to the post 332. In some embodiments, the catch 348 is the feedback system. In other embodiments, the system 310 can include another feedback system. In some embodiments, the user can hear and / or feel the catch 348 contact the ratchet 350 as the post 332 moves upward, downward, or both. This contact can produce one or more clicks. Additionally or alternatively, this contact can provide a force (e.g., a frictional force) that can hold the post 332 in a desired position until the adjustment device 336 is turned again.

[0082] 2. Femoral System 7A and 7B illustrate a femoral system 352. The femoral system 352 may include a femoral baseplate 354. In the illustrated embodiment, the femoral baseplate 354 may include one femoral baseplate 354. In some embodiments, the femoral baseplate 354 may include two or more femoral baseplates 354. In some embodiments, the femoral baseplate 354 is a femoral contacting component. The femoral baseplate 354 may include a planar member. The femoral baseplate 354 may include a first surface 358 configured to be positioned relative to a portion of the femur. For example, the first surface 358 of the femoral baseplate 354 may be configured to engage the bottom of a bony landmark, such as a femoral condyle. The femoral baseplate 354 may include a second surface 356 opposite the first surface 358 positioned on the tibia.

[0083] The femoral system 352 may include an extension member 360. In the illustrated embodiment, the extension member 360 is generally L-shaped. The extension member 360 may include a first portion 362 extending from the femoral baseplate 354. The extension member 360 may include a second portion 364 extending perpendicularly or nearly perpendicularly from the first portion 362. Other configurations of the extension member 360 are also contemplated. In some embodiments, the extension member 360 may be integrally or monolithically formed with the femoral baseplate 354. In some embodiments, the extension member 360 and the femoral baseplate 354 comprise a unitary structure. Rotation of the femoral baseplate 354 may correspondingly rotate the extension member 360, as described herein.

[0084] The femoral system 352 may include a post mount 366. An extension member 360 may extend between the post mount 366 and the femoral base plate 354. The extension member 360 may position the post mount 366 away from the knee joint. The femoral system 352 may include a post 332, as described herein. In some embodiments, the post mount 366 may be coupled to the post 332. In some embodiments, the post mount 366 may be integrally or monolithically formed with the post 332. In some embodiments, the post mount 366 and the post 332 comprise a unitary structure. Translation of the post 332 may correspondingly translate the post mount 366, as described herein.

[0085] A post mount 366 may be coupled to the extension member 360. The post mount 366 may be coupled to the second portion 364 of the extension member 360. The post mount 366 may be attached such that the extension member 360 can rotate relative to the post mount 366. The post mount 366 may also be attached such that the femoral baseplate 354 can rotate relative to the post 332. The femoral system 352 may include a rotational interface 368. The rotational interface 368 may be a pin. The extension member 360 can rotate relative to the tibial baseplate 314 about the rotational interface 368. The femoral baseplate 354 can rotate relative to the tibial baseplate 314 about the rotational interface 368. The rotational interface 368 may be positioned at the center of the femur and / or tibia. The rotational interface 368 may be aligned with an anatomical feature such as the intercondylar notch, Whiteside's Line, or the mechanical axis of the tibia.

[0086] The rotational interface 368 may include an attachment mechanism 370. The attachment mechanism 370 may allow one or more drill guides or other instruments to be attached to the system 310. The attachment mechanism 370 may be parallel to the tibial baseplate 314. The attachment mechanism 370 may be coupled to the post 332. In some embodiments, the attachment mechanism 370 remains in position as the femoral baseplate 354 rotates. The attachment mechanism 370 may be decoupled from the rotation of the extension member 360. The attachment mechanism 370 may be decoupled from the rotation of the femoral baseplate 354.

[0087] The extension member 360 may include a second coupler 374. The second coupler 374 may be configured to couple with the surgical orienting device 14 and / or the reference sensor device 16. The second coupler 374 may include an elongated post. In some embodiments, the second coupler 374 may have a regular shape (e.g., cylindrical). In some embodiments, the second coupler 374 has an irregular shape (e.g., triangular, teardrop-shaped, oval, rectangular). The irregular shape may facilitate alignment of the surgical orienting device 14 in an orientation relative to the extension member 360. In the illustrated embodiment, the second coupler 374 is positioned on a side of the second portion 364. In the illustrated embodiment, the second coupler 374 is positioned such that the longitudinal axis of the surgical orienting device 14 is aligned with the femoral base plate 354. As the femoral baseplate 354 rotates relative to the tibial baseplate 314, the surgical orienting device 14 rotates. As the femoral baseplate 354 translates relative to the tibial baseplate 314, the surgical orienting device 14 translates.

[0088] 3E , the femoral system 352 may include a bracket 376. The second coupler 374 may be configured to couple with the bracket 376. The surgical orientation device 14 may be configured to couple with the bracket 376. The bracket 376 may include a third coupler 378. The third coupler 378 may be configured to couple with the surgical orientation device 14 and / or the reference sensor device 16. The third coupler 378 may have the same shape and / or configuration as the first coupler 324 and / or the second coupler 374. In the illustrated embodiment, the third coupler 378 is positioned on a side of the bracket 376.

[0089] In some methods of use, the surgical orientation device 14 is coupled to the second coupler 374, and the reference sensor device 16 is coupled to the third coupler 378. The surgical orientation device 14 and the reference sensor device 16 are coupled to the femur at an angle. The surgical orientation device 14 and the reference sensor device 16 can be calibrated relative to the femur. The surgical orientation device 14 and the reference sensor device 16 can be zeroed. The role of the third coupler 378 is to hold the surgical orientation device 14 and the reference sensor device 16 at some known angle during calibration or zeroing. The user can move the reference sensor device 16 to the first coupler 324 described herein. The reference sensor device 16 is coupled to the tibia via the first coupler 324. The change in position and / or orientation of the surgical orientation device 14 and / or the reference sensor device 16 relative to each other can then be calculated. The surgical orientation device 14 and / or the reference sensor device 16 calculate the change in angle relative to one another. The surgical orientation device 14 and / or the reference sensor device 16 may measure the coronal plane angle using gyro propagation. The surgical orientation device 14 and / or the reference sensor device 16 may include software and / or hardware that performs gyro propagation. The surgical orientation device 14 and / or the reference sensor device 16 may include one or more algorithms that calculate the angle of the surgical orientation device 14 as it rotates with the femoral baseplate 354.

[0090] FIG. 3E is a perspective view of the system 310. As shown in FIGS. 3E, 8A, and 8B, the femoral system 352 may include a drill guide 380. The drill guide 380 may include one or more apertures 382. These apertures 382 may extend entirely through the drill guide 380. When multiple apertures 382 are used, various numbers, sizes, shapes, and / or locations of apertures 382 may be used. The apertures 382 may be used as guides for drills and / or pins. For example, when the system 310 distracts one or more condyles of the distal femur during a knee replacement procedure, one or more pins (not shown) may be inserted into the distal femur to provide an attachment location for a cutting block (not shown). The apertures 382 may be used as guides for inserting these pins.

[0091] The apertures 382 may be spaced apart from one another in one or more patterns. For example, some of the apertures 382 along the bottom of the drill guide 380 may be slightly higher and / or further away from the tibial baseplate 314 than other apertures along the bottom of the drill guide 380. Similarly, some of the apertures 382 along the top of the drill guide 380 may be slightly higher and / or further away from the tibial baseplate 314 than other apertures along the top of the drill guide 380. In some embodiments, one or more parallel rows of apertures 382 are provided. These rows may be parallel to the tibial baseplate 314. This row or rows of parallel apertures 382 may allow a user to adjust the clearance, as described herein. This row or rows of parallel apertures 382 may allow a user to adjust the cutting block a known distance. This row or rows of parallel apertures 382 may be used, for example, to control the orientation of a cutting block that is subsequently attached to a pin.

[0092] In some embodiments, the drill guide 380 can have two orientations. The drill guide 380 may provide openings for even measurements (e.g., 2 mm, 4 mm, 6 mm, etc.). The drill guide 380 may be inverted for odd measurements (e.g., 1 mm, 3 mm, 5 mm, etc.). The drill guide 380 may include a first leg 384 and a second leg 386. The first leg 384 may be coupled to the attachment mechanism 370. The second leg 386 may also be coupled to the attachment mechanism 370. In some embodiments, when the first leg 384 is coupled to the attachment mechanism 370, a user can utilize even measurements. In FIG. 8A , the first leg 384 is shown coupled to the attachment mechanism 370. In some embodiments, when the second leg 386 is coupled to the attachment mechanism 370, a user can utilize odd measurements. The drill guide 380 may include one or more markings 388. The markings 388 can indicate values ​​associated with the apertures 382. The markings 388 can indicate distance measurements associated with the apertures 382. In FIG. 8B, the markings 388 for the even measurements are inverted for the odd measurements. In some embodiments, each aperture 382 has two markings 388. In some embodiments, each aperture 382 has two markings 388, only one of which is readable by the user. In some embodiments, each aperture 382 has two markings 388, one of which is inverted. In some embodiments, each aperture has two markings 388, only one of which is readable depending on the orientation of the drill guide 380.

[0093] 3E and 7A , drill guide 380 can be a modular device that can be coupled to or decoupled from attachment mechanism 370. In some embodiments, attachment mechanism 370 can be coupled to rotating baseplate 368. In some embodiments, rotating baseplate 368 is coupled to post 332. In some embodiments, post 332 is coupled to tibial baseplate 314. In some embodiments, drill guide 380 can be stabilized relative to tibial baseplate 314. Drill guide 380 can be rotatably coupled to tibial baseplate 314. Drill guide 380 can be parallel to tibial baseplate 314. In some embodiments, rotation of femoral baseplate 354 is independent of positioning of drill guide 380. System 310 can achieve alignment of drill guide 380 relative to tibial baseplate 314 as described herein.

[0094] In some embodiments, the system 310 may further include one or more springs (not shown) capable of applying a constant spring force to any one or more anatomical structures with which the femoral baseplate 354 contacts. For example, the system 310 may include a pre-tensioned spring that can be released when the system 310 is positioned within an anatomical joint (e.g., a knee joint), allowing a predetermined force to be applied from the femoral baseplate 354 to any anatomical structures with which it contacts (e.g., the condyles). In some embodiments, the applied force can be approximately 70-80 N. In other embodiments, the applied force can be approximately 60-90 N. Other forces and / or force ranges are possible. The force applied by each spring may be different. In some embodiments, the system 310 does not include one or more springs that apply a distraction force. The distraction force can be applied solely by the posts 332 described herein. A potential disadvantage of springs is that the force is not constant over a range of distraction distances. The post 332 can provide a constant force over a range of distraction distances. A potential disadvantage of a spring is that the force is not controlled and / or limited by the surgeon. A potential disadvantage of a spring is that springs are more likely to cause ligament damage. The post 332 can provide a force that is controlled and / or limited by the user.

[0095] The above-described system 310 can be biocompatible for short-term exposure to the internal anatomy of a knee or other human joint and can be sterilized by autoclaving and / or gas. System 310 or other similar distraction devices can also be used in joints other than the knee. For example, system 310 can be used to distract an elbow or other joint.

[0096] 3. Overview of distraction 9A-9C are additional views showing the system 310 mounted on the patient's tibia and femur. FIG. 9A shows the initial position of the system 310. FIGS. 9B and 9C show the subsystems of the system 310. In some embodiments, the tibial baseplate 314 may be proximate the femoral baseplate 354. In some embodiments, the extension member 320 may be proximate the extension member 360. In some embodiments, the post mount 366 may be proximate the mounting block 322. The surgical orientation device 14 may be coupled to the second coupler 374 (see also FIG. 7A). The reference sensor device 16 may be coupled to the first coupler 324 (see also FIG. 4A). The reference sensor device 16 may be coupled to the additional coupler 326 (see also FIG. 11A). As described herein, the first coupler 324, the second coupler 374, and / or the third coupler 378 can be aligned along a mechanical axis. The additional coupler 326 can be at some angle to the mechanical axis, such as orthogonal to the mechanical axis.

[0097] FIG. 9A illustrates how the tibial system 312 and the femoral system 352 can function together. The femoral system 352 can be moved up and down (e.g., proximally and distally) relative to the tibial baseplate 314 by one or more adjustment devices 336. The adjustment devices 336 can be used to define and / or facilitate movement of the femoral system 352. The adjustment devices 336 can include an interface 338 that allows a user to rotate the adjustment device 336. See FIG. 4A for more information. The adjustment devices 336 can be located within a mounting block 322. The mounting block 322 can provide stability to the post 332 as it translates within the mounting block 322. The adjustment devices 336 and the post 332 can comprise the rack and pinion system described herein.

[0098] The post 332 can extend between the tibial system 312 and the femoral system 352. The post 332 can be coupled to a post mount 366 on the femoral system 352. The post mount 366 can be located on one side of the mounting block 322, and the post 332 can extend through the opposite side of the mounting block 322. Movement of the post 332 can correspondingly move the femoral system 352 relative to the tibial system 312. Translation of the post 332 can correspondingly translate the femoral system 352 relative to the tibial system 312.

[0099] During distraction, the post 332 translates within the guide portion 330 of the mounting block 322. See FIG. 4A. As the post 332 moves, the femoral system 352 also moves. The post 332 can cause translation of the post mount 366 coupled to it. The post mount 366 can cause translation of the extension member 360 and femoral base plate 354. The femoral system 352 translates with the post 332 as a unit.

[0100] Translation of the post 332 allows the femoral baseplate 354 to move relative to the tibial baseplate 314 to increase or decrease the gap between them. The femoral baseplate 354 can be moved away from the tibial baseplate 314 (e.g., proximally). The femoral baseplate 354 can also be moved toward the tibial baseplate 314 (e.g., distally). The femoral baseplate 354 can be moved to increase the gap between the tibia and femur.

[0101] For example, the femoral baseplate 354 can be moved vertically upward (e.g., proximally) to apply pressure to the distal condyles of the femur or other bony structures within the body. The femoral baseplate 354 can move the femoral condyles to a desired position. This movement can distract the knee joint, surrounding soft tissue, and / or ligaments. In some embodiments, one or more pressure or force gauges can also be incorporated into the system 310 to determine the amount of compressive force that the femoral baseplate 354 applies to the femoral condyles.

[0102] In some embodiments, the femoral baseplate 354 can be rotatably coupled to the post mount 366. The femoral baseplate 354 can be adjusted relative to the patient's anatomy. For example, the femoral baseplate 354 can rotate relative to a plane that includes the tibial baseplate 314. In a preferred configuration, the femoral baseplate 354 can rotate in one or more directions about the post mount 366. This rotation can facilitate use of the system 310 in knee joints that vary in size, for example, where the femoral condyles in a particular knee joint are spaced apart significantly. This rotation allows the femoral baseplate 354 to be inserted through a relatively narrow body incision and, once inside the knee joint, can also be rotated to engage the femoral condyles.

[0103] 9B, the system 310 may include markings 340 that indicate the distance the post 332 has moved. In some embodiments, the markings 340 are scales that are visible to the user. In some embodiments, the markings 340 are captured by a camera 344. The post 322, or a portion thereof, that extends beyond the mounting block 322 may include the markings 340. The markings 340 may be aligned with the camera 344 of the reference sensor device 16. The camera 344 may capture an image of the markings 340. The markings 340 may be the distraction distance between the tibial baseplate 314 and the femoral baseplate 354.

[0104] In some embodiments, when the system 310 is being used to distract the knee joint, one or more ligaments on one or both sides of the knee can be released, allowing the user to modify the knee ligament(s) to achieve a desired balance of forces around the knee joint.

[0105] 9A and 9C, the system 310 may include a drill guide 380 for one or more femoral cuts. In some methods of use, a user may perform the femoral cuts after distraction. As described herein, the drill guide 380 may be a modular device that may be coupled to or detached from the attachment mechanism 370 shown in FIG. 9C. In some embodiments, the drill guide 380 may be stabilized relative to the tibial baseplate 314. The drill guide 380 may be parallel to the tibial baseplate 314. In some embodiments, the drill guide 380 allows a user to place one or more pins that may assist in attaching a cutting block configured to perform one or more cuts in the femur at a selected angle relative to (e.g., parallel to) the tibial baseplate 314.

[0106] FIG. 10 illustrates an embodiment of a system 410. The system 410 can include any of the features of the system 310 described herein. As shown in FIG. 10, the system 410 can include a tibial system 412, a tibial baseplate 414, a mounting block 422, a first coupler 424, an additional coupler 426, a post 432, a rack 434, an adjustment device 436, an interface 438, a femoral system 452, a femoral baseplate 454, a clasp 458, a post mount 466, and a second coupler 474. FIG. 10 also illustrates the system 410 being used with the knee in extension. The system 310 can be used when the knee is in extension, as described herein. The clasp 458 is shown as including a knob. A user can rotate the knob to limit the movement of the post 432.

[0107] 4. Distraction in extension During a knee replacement procedure, the above-described system 310 can be used to align and balance the ligamentous structures of the knee and / or to determine the orientation of one or more cuts along the femur. For simplicity, the following description of distraction in extension will be provided with reference to system 310, although system 410 can be used as well.

[0108] In some applications, the proximal (i.e., upper) tibia can be cut. In some applications, the tibia is resected before using system 310 and / or before resecting the femur. For example, as described above, tibial preparation system 210 or other tibial preparation systems can be used to resect a portion or portions of the tibia so that the proximal end of the tibia comprises a generally flat surface or plateau. Based on preoperative determinations of the desired varus / valgus, posterior / anterior, and / or other angles for this tibial resection surface, the plateau can be perpendicular to the mechanical axis or at an angle other than perpendicular to the mechanical axis.

[0109] In some applications, the femur can be cut. In some applications, the femur is resected prior to using the system 310. For example, as described above, femoral preparation system 10 or other femoral preparation systems can be used to resect a portion or portions of the femur so that the distal end of the femur has a substantially flat surface. Depending on the preoperative determination of the desired varus / valgus, posterior / anterior, and / or other angle for this femoral resection, the resection can be perpendicular to the mechanical axis or at an angle other than perpendicular to the mechanical axis. In some techniques, this cut is referred to as a distal femoral cut (DFC). In a DFC, the distal (i.e., lower) portion of the femur is removed.

[0110] In some methods of use, the leg is positioned in full extension (not shown). The tibial baseplate 314 and the femoral baseplate 354 can be inserted into the knee joint. The tibial baseplate 314 can be positioned on the tibial plateau. The femoral baseplate 354 can be positioned above the tibial plateau. In some embodiments, the femoral baseplate 354 is positioned below the femoral resection. In some embodiments, the femoral baseplate 354 is positioned below the femoral condyles. Once the tibial baseplate 314 and the femoral baseplate 354 are inserted into the knee joint, the femoral baseplate 354 can be moved by turning the adjustment device 336. For example, the femoral baseplate 354 can be moved away from the tibial baseplate 314. In some embodiments, the femoral baseplate 354 is moved to contact the distal surface of the femoral condyle. In some embodiments, the femoral baseplate 354 moves into contact with the resected femur. This movement causes the system 310 to apply one or more opposing forces to the proximal tibia and distal femur. This force can distract the knee joint and the surrounding soft tissue and / or ligaments. The femoral baseplate 354 can apply different amounts of pressure or force to each femoral condyle. The femoral baseplate 354 can also apply the same amount of pressure or force to each femoral condyle. In some methods of use, the femoral baseplate 354 can rotate to apply equal forces or pressures to each femoral condyle. In some embodiments, the tibial baseplate 314 can remain stationary while the femoral baseplate 354 translates and / or rotates.

[0111] In some methods of use, a user may distract the knee joint. The user may apply force until the femur is held in tension. The user may have a visual indication of the gap as it increases. In some methods of use, the user may have a visual indication that the gap or distance between one femoral condyle and the tibial plateau is substantially the same as the gap or distance between the other femoral condyle and the tibial plateau. In some methods of use, the user may have a visual indication that the gap or distance between the femoral and tibial resections is substantially rectangular. In some methods of use, the user may have a visual indication that the femoral resection is parallel to the tibial resection.

[0112] In some embodiments, a user can release one or more ligaments within the knee joint before or during knee distraction to facilitate simultaneous symmetry of the gap, alignment of the mechanical axes, and / or balancing of the soft tissue and / or ligaments within the knee joint. In some methods of use, a user can modify the soft tissue to align the femoral baseplate 354 and the tibial baseplate 314. A user can score or cut the soft tissue to adjust for the laxity of the knee joint. A user performs soft tissue balancing until the femoral baseplate 354 and the tibial baseplate 314 are parallel or nearly parallel. A user can release the ligaments when the knee is in extension based on the angle output of the surgical orientation device 14. In some embodiments, a user releases the soft tissue until the angle measurement reaches zero. An angle measurement of zero indicates that the femoral baseplate 354 is parallel to the tibial baseplate 314 .

[0113] The surgical orientation device 14 and / or reference device 16 can be configured to measure rotations related to the relative tension in the medial and lateral soft tissues of the medial and / or lateral sides of the knee joint. In some embodiments, the adjustment device 336 is calibrated so that rotations of the interface 338 correspond to a resulting force. For example, each rotation may correspond to a predetermined amount of force or pressure applied to the femoral baseplate 354. In some embodiments, the system 310 can calculate the force from the distraction distance. In some embodiments, the system 310 can calculate the force from the area of ​​the femoral baseplate 354 and / or the tibial baseplate 314. In some embodiments, the system 310 can include sensors or other structures that can rely on the surgical orientation device 14 and / or reference sensor device 16 for information regarding the amount of force applied to the femoral baseplate 354. In some embodiments, the system 310 may include sensors or other structures that may rely on information from the surgical orientation device 14 and / or the reference sensor device 16 regarding the amount of force being applied to the tibial baseplate 314.

[0114] The surgical orientation device 14 may be configured to display the rotation of the femur, which is detected by the surgical orientation device 14 when the soft tissue is tensioned. The surgical orientation device 14 may be configured to display the rotation of the femoral baseplate 354 relative to the tibial baseplate 314 when the knee is tensioned. The surgical orientation device 14 may display this information, for example, on a visual display located within the surgical field. If too much tension, pressure, and / or force is being applied to the soft tissue, the user can change the tension by adjusting (e.g., turning) one or more of the adjustment devices 336.

[0115] The surgical orientation device 14 and / or the reference sensor device 16 can be configured to measure the distraction distance between the femoral baseplate 354 and the tibial baseplate 314. As described herein, the camera 344 can capture an image corresponding to the distraction distance. The camera 344 can capture an image of the markings 340. This image may correspond to the distance the post 332 translates during distraction. This distance changes as the post 332 slides within the mounting block 322. As the femoral baseplate 354 is translated and / or adjusted in rotation to distract the knee joint, the camera 344 can capture an image corresponding to the distraction distance. This image may correspond to the distraction distance between the femoral baseplate 354 and the tibial baseplate 314.

[0116] In some methods, the surgical orientation device 14 and / or the reference sensor device 16 convert the image of the camera 344 into a distraction distance. In some methods, the surgical orientation device 14 and / or the reference sensor device 16 convert the image of the camera 344 into an extension measurement of the post 332. In some embodiments, the surgeon provides input (e.g., pressing a button, interacting with the user input device 28, etc.) to collect data from the reference device 16. In some embodiments, the surgeon provides input (e.g., pressing a button) to collect data from the camera 344. In some embodiments, the surgeon provides input (e.g., pressing a button) to collect data from the reference device 16 and the camera 344 simultaneously. In some methods, the reference device 16 and / or the camera 344 transmit data to the surgical orientation device 14 only if the reference device 16 is stable or not moving.

[0117] The surgical orientation device 14 can be configured to display information during distraction. The surgical orientation device 14 can display information in real time. The surgical orientation device 14 can also display information while acquiring data from the reference device 16 and / or the camera 344. The surgical orientation device 14 can display the distraction distance of the femur and tibia. This information can be a measured distance (e.g., 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc.). This information can also be any visual indicator (e.g., a bullseye, target, sliding scale, etc.). The surgical orientation device 14 can display this information, for example, on a display 26 located within the surgical field.

[0118] The surgical orientation device 14 and / or the reference sensor device 16 can store any data related to distraction. The surgical orientation device 14 and / or the reference sensor device 16 can be configured to store the distraction distance of the femur and tibia when the leg is in extension. The surgical orientation device 14 and / or the reference sensor device 16 may be configured to store the extension gap when the leg is in extension. The surgical orientation device 14 and / or the reference sensor device 16 can store the distraction distance in extension for later comparison with the leg in flexion. The surgical orientation device 14 and / or the reference sensor device 16 can store the distraction distance for post-operative use.

[0119] In some applications, the femur is resected before the leg is placed in extension. The system 310 can measure the angle relative to the tibial resection. In some applications, the femur is resected using the femoral preparation system 10 described herein. The femoral preparation system 10 can position the cutting block at a specific angle relative to the mechanical axis of the femur.

[0120] 5. Distraction in flexion Another cut that can be made in some knee procedures is a post-femoral cut (PFC). In preparation for a post-femoral cut, the leg can be placed in approximately 90 degrees of flexion as shown in Figure 11A, which shows the leg in flexion with the tibial baseplate 314 and femoral baseplate 354 within the knee joint.

[0121] In some methods of use, the proximal (i.e., upper) tibia can be cut as shown in FIG. 11A. Using tibia preparation system 210 or other tibia preparation systems, a portion or portions of the tibia can be resected so that the proximal end of the tibia comprises a generally flat surface or plateau. In some methods of use, the femur can be cut as shown in FIG. 11A. In some methods of use, using femur preparation system 10 or other femur preparation systems, a portion or portions of the femur can be resected so that the distal end of the femur comprises a generally flat surface or plateau. In some embodiments, the femur is resected after distraction in extension.

[0122] In some methods of use, after completing the tibial resection and distal femoral resection, the user flexes the knee 90 degrees and inserts the system 310. In some methods of use, the leg is positioned in flexion. The tibial baseplate 314 and the femoral baseplate 354 can be inserted into the knee joint. The tibial baseplate 314 can be positioned on the tibial plateau. The femoral baseplate 354 can be positioned above the tibial plateau. In some embodiments, the femoral baseplate 354 is positioned below the femoral condyles, as shown in FIG. 11A.

[0123] Once the tibial baseplate 314 and the femoral baseplate 354 are inserted into the knee joint, the femoral baseplate 354 can be moved by rotating the adjustment device 336. As described herein, rotating the adjustment device 336 can move the femoral baseplate 354 away from the tibial baseplate 314, thereby distracting the knee joint. The adjustment device 336 can cause translation of the post 332. The post 332 can be coupled to the femoral baseplate 354 such that translation of the post 332 causes translation of the femoral baseplate 354. The femoral baseplate 354 can be moved away from the tibial baseplate 314, as shown in FIG. 11A . In some embodiments, the femoral baseplate 354 moves into contact with the posterior surfaces of the femoral condyles. This movement causes the system 310 to apply one or more opposing forces to the proximal tibia and distal femur. This force can distract the knee joint and the surrounding soft tissues and / or ligaments. The system 310 can apply separate, opposing forces to the tibial plateau and femoral condyles. Each condyle can be distracted individually, simultaneously, and / or sequentially.

[0124] In some embodiments, the femoral baseplate 354 can rotate, as shown in FIG. 11B . The femoral baseplate 354 can rotate as the post 332 translates. The femoral system 352 can include a post 332 as described herein. The femoral system 352 can include a post mount 366 coupled to the post 332. In some embodiments, the post mount 366 and the post 332 form a unitary structure. Translation of the post 332 can cause corresponding translation of the post mount 366, as described herein. The post mount 366 can allow the femoral baseplate 354 to rotate relative to the post 332. The femoral system 352 can include a rotational interface 368, not shown in FIG. 11B . The rotational interface 368 can be a pin. The femoral baseplate 354 can rotate relative to the post 332 about the rotational interface 368. The femoral baseplate 354 can rotate relative to the tibial baseplate 314 about the rotational interface 368.

[0125] The femoral baseplate 354 can apply different amounts of pressure or force to each femoral condyle. The femoral baseplate 354 can apply the same amount of pressure or force to each femoral condyle. The femoral baseplate 354 can be rotated to place both femoral condyles in tension. The post 332 can be translated by the system 310 until both femoral condyles are in tension. The post 332 can be translated until both femoral buds are under a predetermined force. The adjustment device 336 can be rotated to distract the joint. The adjustment device 336 can be rotated until both collateral ligaments are in tension. In some embodiments, the tibial baseplate 314 can remain stationary while the femoral baseplate 354 is rotated.

[0126] 11B shows the additional coupler 326 and the second coupler 374. FIG. 11C shows the surgical orientation device 14 and the reference sensor device 16 coupled to the system 310. As described herein, the mounting block 322 may include one or more additional couplers 326. The additional couplers 326 can be configured to couple with the reference sensor device 16. The one or more additional couplers 326 can be positioned on any surface of the mounting block 322. The additional couplers 326 can be positioned such that the longitudinal axis of the reference sensor device 16 is orthogonal to the longitudinal axis of the tibia. The additional couplers 326 can also be positioned such that the longitudinal axis of the reference sensor device 16 is orthogonal to the mechanical axis.

[0127] The femoral system 352 may include a second coupler 374. The second coupler 374 can be configured to couple with the surgical orienting device 14. The second coupler 374 can be positioned such that the longitudinal axis of the surgical orienting device 14 is aligned with the longitudinal axis of the tibia. The second coupler 374 can also be positioned such that the longitudinal axis of the surgical orienting device 14 is aligned with the mechanical axis.

[0128] 11C shows the surgical orientation device 14 and the reference sensor device 16. The surgical orientation device 14 can be coupled to a second coupler 374. The reference sensor device 16 can be coupled to an additional coupler 326. As described herein, the surgical orientation device 14 is rotatably coupled to a femoral baseplate 354. As the femoral baseplate 354 rotates, the surgical orientation device 14 can also rotate.

[0129] As described herein, the reference sensor device 16 can measure the distraction distance. The reference sensor device 16 may include a camera 344. The camera 344 can provide a measurement of distraction when the leg is in extension. The camera 344 can also provide an indication of the extension of the post 332. For example, the camera 344 can provide a distance measurement while the femoral baseplate 354 is translated and / or adjusted by rotation to distract the knee joint. This distance measurement can correspond to the distraction distance between the femoral baseplate 354 and the tibial baseplate 314. In some embodiments, the camera 344 can capture an image of the markings 340 described herein. In some embodiments, the camera 344 can read the markings 340, such as machine-readable markings. The surgical orientation device 14 can be configured to display the flexion gap. In some methods of use, a user can read the display 26 of the surgical orientation device 14. In some methods of use, a user can read the markings 340. The system 310 may calculate the anterior-posterior shift required to match the flexion and extension gaps. In some embodiments, the user may compare two numbers shown on the display 26 of the surgical orienting device 14. In some embodiments, the display may show the difference in gaps.

[0130] The surgical orientation device 14 may be configured to display the distraction distance, as described herein. The surgical orientation device 14 can provide a visual indication of the gap as the gap increases. The surgical orientation device 14 and / or the reference sensor device 16 can convert the image from the camera 344 into a distraction distance. The user can refer to the display 26 of the surgical orientation device 14 to determine the distraction distance. The distraction distance can be displayed in real time. The user can read the distraction distance on the display 26 of the surgical orientation device 14.

[0131] The surgical orientation device 14 may be configured to display the rotation angle of the surgical orientation device 14 relative to the tibial baseplate 314. The rotation angle of the surgical orientation device 14 may correspond to the posterior condyle angle. The display 26 may indicate the rotation angle of the femoral baseplate 354. A user can read the rotation angle on the display 26 of the surgical orientation device 14. In some methods of use, the surgical orientation device 14 may provide a visual indication of whether the rotation angle is within a predetermined range. In some methods of use, the surgical orientation device 14 may provide a visual indication of femoral rotation. In some methods of use, the surgical orientation device 14 may provide a visual indication of soft tissue balancing. In some methods of use, the surgical orientation device 14 may provide a visual indication of the femoral condyle obliqueness relative to the tibial plateau. The display 26 may provide a digital display of the rotation angle.

[0132] The surgical orientation device 14 and / or the reference sensor device 16 can record the rotation angle. The surgical orientation device 14 and / or the reference sensor device 16 can also store the rotation angle. The surgical orientation device 14 can provide angle readings in real time. The rotation angle of the surgical orientation device 14 can correspond to the posterior condylar angle. The rotation angle of the surgical orientation device 14 can correspond to the posterior condylar angle input into the drill guide or cutting guide. The user can set the angle of the cutting block 394 or the drill guide 380 based on the rotation angle displayed on the surgical orientation device 14. The cutting block 394 or the drill guide 380 with the implant can be adjustable based on the posterior condylar angle. The system 310 provides an accurate reading of the posterior condylar angle.

[0133] In some methods of use, the surgical orientation device 14 may provide a visual indication of the medial distraction distance. In some methods of use, the surgical orientation device 14 may provide a visual indication of the lateral distraction distance. In some methods of use, the surgical orientation device 14 and / or the reference sensor device 16 may calculate the medial / lateral distraction distance based on a rotation angle of the surgical orientation device 14. In some methods of use, the surgical orientation device 14 and / or the reference sensor device 16 may calculate the medial / lateral distraction distance based on the distraction distance. In some methods of use, the surgical orientation device 14 and / or the reference sensor device 16 may calculate the medial / lateral distraction distance based on parameters of the femoral base plate 354. In some methods of use, the surgical orientation device 14 may provide a visual indication that the gap or distance between one femoral condyle and the tibial plateau is substantially the same as the gap or distance between the other femoral condyle and the tibial plateau. In some methods of use, the surgical orientation device 14 may provide a visual indication of the rotation angle. In some methods of use, the surgical orientation device 14 may provide a visual indication of the distraction distance. In some methods of use, the surgical orientation device 14 may provide a visual indication of a parameter of the baseplate. In some methods of use, the surgical orientation device 14 may provide a visual indication of the medial and lateral distraction distance. In some methods of use, the distraction distance is an input to the system 310. In some methods of use, one or more parameters of the tibial baseplate 314 are an input to the system 310. In some methods of use, one or more parameters of the femoral baseplate 354 are an input to the system 310. In some methods of use, the condylar width of the femur is an input to the system 310. In some methods of use, the surgical orientation device 14 may provide a visual indication of a measurement of the condylar width of the femur itself. The measurement of the condylar width may be useful in calculating the medial and lateral distraction distance.In some methods of use, the surgical orientation device 14 may provide a visual indication of the obliqueness of the gap or distance between the posterior femoral condyle and the tibial plateau. In some methods of use, the surgical orientation device 14 may provide a visual indication of the obliqueness of the posterior femoral condyle relative to the tibial plateau. In some methods of use, the surgical orientation device 14 may provide a visual indication of the obliqueness of the posterior femoral resection relative to the tibial plateau after the posterior femoral resection has been made. The visual indication of the posterior condyle may be a useful final confirmation after the cut has been made. The visual indication of the posterior femoral resection may also be a useful final confirmation after the cut has been made.

[0134] In some methods of use, the surgical orientation device 14 may provide a visual indication of the distraction distance in flexion compared to the distraction distance in extension. The display 26 may provide a digital representation of the distraction distance. The user may visually verify the digital representation of the distraction distance with one or more additional markings 340, such as a scale visible to the user. The display 26 may provide a digital representation of the distraction distance comparison.

[0135] In some methods of use, the user can install the drill guide 380 and drill holes with an appropriate anterior-posterior shift based on the anterior-posterior shift calculated by the surgical orientation device 14. This anterior-posterior shift can be the difference between the extension gap and the flexion gap. The user can use selected apertures 382 in the drill guide 380 based on a comparison of the flexion distraction distance and the extension distraction distance. For example, if the difference between the flexion distraction distance and the extension distraction distance is 2 mm, the user can select a different parallel aperture row, such as an aperture row that increases or decreases the height of the cutting plane of the cutting block by 2 mm. For example, if the difference between the flexion distraction distance and the extension distraction distance is 4 mm, the user can select a different parallel aperture row, such as an aperture row that increases or decreases the height of the cutting plane of the cutting block by 4 mm. In some embodiments, the user matches the flexion gap with the extension gap. In some embodiments, the user cannot match the flexion distraction gap with the extension distraction gap due to, for example, anatomical constraints. The system 310 can calculate this gap difference. The user can select a row of parallel openings 382 in the drill guide 380 that corresponds to this gap difference. The row of parallel openings 382 in the drill guide 380 can adjust the femoral cut parallel to the tibial baseplate 314. The row of parallel openings 382 in the drill guide 380 can adjust the femoral cut to match the gap in flexion and extension. The user can attach the implant sizing / drill guide onto the distal resection surface of the femur. The user can select the appropriate universal cutting block 394. The user can remove the implant sizing / drill guide. The user can attach the universal cutting block 394. The user can complete the resection. The universal cutting block 394 is positioned with the posterior resection slot parallel to the tibial resection by precisely aligning the drilled guide holes.

[0136] In some alternative methods, the user may measure the posterior condylar angle on the surgical orientation device 14. The posterior condylar angle can be determined from accelerometer measurements. The user can attach an implant sizing / drill guide onto the distal resection surface of the femur. The user can set the implant sizing / drill guide to this angle. The surgical orientation device 14 provides an accurate method for measuring the posterior condylar angle. The user can drill holes. The user can select the appropriate universal cutting block 394. The user can remove the implant sizing / drill guide. The user can attach the universal cutting block 394. The user can complete the resection. The universal cutting block 394 is positioned with the posterior resection slot parallel to the tibial resection by precisely aligning the drilled guide holes.

[0137] The surgical orienting device 14 and / or the reference sensor device 16 may be configured to measure the tension in the soft tissues on the medial and / or lateral sides of the knee joint. In some embodiments, the surgical orienting device 14 and / or the reference sensor device 16 may be configured to measure the tension from the distraction distance. In some embodiments, the system 310 may include a sensor or other structure that may rely on information to the surgical orienting device 14 and / or the reference sensor device 16 regarding the degree of tension being applied. The surgical orienting device 14 may be configured to display this force.

[0138] In some embodiments, a user can release one or more ligaments within the knee joint before or during knee distraction to facilitate simultaneous symmetry of the gap, alignment of the mechanical axes, and / or balancing of the soft tissues and / or ligaments within the knee joint. In some methods of use, a user can modify the soft tissue to align and change the angle between the femoral baseplate 354 and the tibial baseplate 314. A much more common scenario is to modify the soft tissue only in extension. A user can score or cut the soft tissue to adjust for knee laxity. A user performs soft tissue balancing until the desired angle between the femoral baseplate 354 and the tibial baseplate 314 is achieved.

[0139] The surgical orientation device 14 and / or the reference sensor device 16 can store any data related to distraction. The surgical orientation device 14 and / or the reference sensor device 16 can be configured to store the distraction distance of the femur and tibia. The surgical orientation device 14 and / or the reference sensor device 16 can be configured to store the distraction distance of the femur and tibia when the leg is in flexion. The surgical orientation device 14 can compare the distraction distance in flexion with the distraction distance in extension. The surgical orientation device 14 can store data for post-operative comparison. The surgical orientation device 14 can store data for post-operative recording of parameters used during the procedure.

[0140] After distraction, holes can be drilled in the femur and reference pins can be inserted. As described herein, the drill guide 380 can include one or more apertures 382. These apertures 382 can be used to guide the drills and / or pins. For example, when the system 310 distracts the distal femur in a knee replacement procedure, one or more pins can be inserted into the resection surface to provide a mounting location for a cutting block. The apertures 382 can be used as guides for inserting these pins.

[0141] The apertures 382 can be spaced apart in one or more patterns. For example, some of the apertures 382 can be slightly higher and / or further away from the tibial baseplate 314 than other apertures 382. This spacing can be used, for example, to control the orientation of a cutting block attached to the pins. Reference pins can be inserted into various apertures 382 in the drill guide 380, again depending on the desired resection angle. For example, as described above, some of the apertures 382 can be positioned at slightly different heights or elevational locations on the drill guide 380. Depending on where the reference pins are inserted, slightly different resection angles (e.g., zero degrees, plus three degrees, minus three degrees, etc., relative to the tibial resection) can be achieved.

[0142] FIG. 11D illustrates the use of a sizing guide 390. The system 310 can be removed as shown in FIG. 11D. The sizing guide may correspond to the selected implant. The sizing guide 390 can be adjusted to match the rotational angle displayed on the surgical orientation device 14 during distraction in flexion. The system 310 can set the pin location for the femoral cutting block. The system 310 can also set the rotational alignment for the femoral cutting block. The sizing guide 390 is an example of a representative sizing / drill guide for an implant instrument set. Other commercially available examples exist. FIG. 11E illustrates an alternative sizing guide 392. FIG. 11F illustrates an embodiment of a universal cutting block 394.

[0143] Once the reference pins are inserted, a cutting block 394 can be placed on or coupled to the reference pins. A saw or other cutting device can then be used to make the appropriate PFC cut(s) along the femur (e.g., an anterior cut, additional posterior cuts, and / or chamfer cuts). Once all of the tibia and / or femur cuts have been made using the systems and / or methods described above, one or more knee prostheses can be attached to the distal femur and / or proximal tibia. The knee prosthesis device may include a knee replacement. The knee replacement can be evaluated by the user to verify that the alignment of the prosthetic components within the knee replacement does not result in any undesired wear, interference, and / or damage to the patient's anatomy or to the prosthetic components themselves.

[0144] 12A-12D are additional views illustrating the femoral baseplate 354 and the tibial baseplate 314. The femoral baseplate 354 can be rotated relative to the tibial baseplate 314. The system 310 can measure the rotation angle of the femoral baseplate 354, as shown in FIG. 12C. The system 310 can measure the distraction distance on the medial and / or lateral sides of the knee, as shown in FIG. 12D. FIG. 12E is a schematic diagram illustrating a drill guide 380 including an aperture 382. The drill guide 380 can be coupled to the tibial baseplate 314 as described herein. The drill guide 380 can remain parallel to the tibial baseplate 314 during rotation of the femoral baseplate 354.

[0145] C. Alternative Femoral Preparation and Knee Distraction Systems 13A-13E illustrate an embodiment of a system 510. The system 510 can be used to perform numerous functions, as described herein. The system 510 can include any of the features of any other system described herein, including the system 310. The system 510 can be configured to distract the knee joint during a knee replacement procedure. The system 510 can be configured to measure the rotation of the open bone relative to the tibial resection. The system 510 can be configured to orient the resection plane. The system 510 can be configured to guide a posterior resection. The system 510 can be used to prepare the femur, such as to facilitate a posterior femoral cut. The system 510 can be configured to provide information about how to resect the femur.

[0146] The system 510 may include a surgical orientation device 14 and a reference sensor device 16, as described herein. The system 510 may further include one or both of a tibial system 512 and a femoral system 552, as described herein. While the tibial system 512 and the femoral system 552 are described as separate subsystems, the system 510 may also be considered a single instrument. In some embodiments, the system 510 may be implemented as an inseparable assembly. In some embodiments, the separate subsystems of the system 510 may be separately positioned on or within a patient's body. In some embodiments, the separate subsystems of the system 510 may be simultaneously positioned on or within a patient's body. FIG. 13E illustrates additional features described herein.

[0147] 1. Tibial System 14A and 14B illustrate a tibial system 512. The tibial system 512 can include any of the features of the tibial system 312. The tibial system 512 can include a tibial baseplate 514. The tibial baseplate 514 can include a first surface 518 configured to align with a flat surface of the resected tibia. The tibial baseplate 514 can include a second surface 516 opposite the first surface 518 positioned on the femur. The tibial system 512 can include an extension member 520. The tibial system 512 can include a mounting block 522. The extension member 520 can extend between the mounting block 522 and the tibial baseplate 514. The extension member 520 can position the mounting block 522, for example, anteriorly, away from the knee joint.

[0148] The mounting block 522 may include a first coupler 524. The first coupler 524 may be configured to couple with the surgical orientation device 14 and / or the reference sensor device 16. The first coupler 524 may include any of the coupler features described herein. In the illustrated embodiment, the first coupler 524 is positioned on a bottom surface of the mounting block 522. In the illustrated embodiment, the first coupler 524 extends perpendicular to the tibial resection. In the illustrated embodiment, the first coupler 524 is positioned such that the longitudinal axis of the reference sensor device 16 is aligned with the longitudinal axis of the tibia. The axis of the tibia may be perpendicular to the tibial resection. In the illustrated embodiment, the first coupler 524 is positioned such that the longitudinal axis of the reference sensor device 16 is aligned with the longitudinal axis of the tibia. The axis of the tibia may be perpendicular to the tibial resection. In the illustrated embodiment, the first coupler 524 is positioned such that the longitudinal axis of the reference sensor device 16 is aligned with the mechanical axis associated with the knee joint, e.g., the tibia. In some embodiments, the mounting bracket is positioned to align with the mechanical axis of the leg. Lock 522 may include one or more additional or alternative couplers as described herein. This can happen.

[0149] The mounting block 522 may include a guide portion 530. The guide portion 530 may extend the entire length of the mounting block 522, or may extend only a portion of it. The guide portion 530 may include at least one opening in the bottom of the mounting block 522. In some embodiments, the guide portion 530 may include openings in the bottom of the mounting block 522 and the top of the mounting block. The guide portion 530 may include at least two diagonally positioned openings. In some embodiments, the guide portion 530 may be a groove extending into the mounting block 522. In some embodiments, the guide portion 530 may include a round or circular groove extending into the mounting block 522. Other configurations for the guide portion 530 are also contemplated, such as triangular, oval, square, or polygonal grooves.

[0150] The mounting block 522 can be configured to facilitate movement of the post 532 of the femoral system 552 therein. The post 532 and the guide portion 530 can have complementary or corresponding cross-sectional shapes. The post 532 and the guide portion 530 can have corresponding cross-sectional dimensions or diameters. In some embodiments, the guide portion 530 and the post 532 have substantially similar cross-sectional dimensions. The post 532 and the guide portion 530 can be shaped to allow metered movement of the post 532 within the guide portion 530. The guide portion 530 can guide the post 532 through the mounting block 522. The guide portion 530 can be configured to allow the post 532 to slide within the mounting block 522. As described herein, the post 532 can be coupled to the femoral system 552. The post 532 can be part of an actuation system that effects movement of the femoral system 552 relative to the tibial system 512.

[0151] In some embodiments, a portion of the post 532 and the guide portion are round. Advantages of the post 532, or a portion thereof, being round or circular include reduced tolerance between the mounting block 522 of the tibial system 512 and the post 532 of the femoral system 552. Advantages include improved alignment between the tibial system 512 and the femoral system 552. Advantages include increased precision in aligning the markings or markings located on the post 532 with the camera 334 of the reference sensor device 16. Advantages include increased precision of movement between the tibial system 512 and the femoral system 552. Advantages include reduced or no undesired movement, such as lateral movement, between the tibial system 512 and the femoral system 552. Advantages include reduced manufacturing costs associated with manufacturing the round guide portion 530 and the round post 532.

[0152] 14B shows the post 532 in one position relative to the mounting block 522. The post 532 may include a marking 540, which may extend below the mounting block 522. The post 532 may include a rack 534, which may extend below the mounting block 522 in the position shown. The post 532 may extend from below the mounting block 522 to above the mounting block 522. The post 532 may be connected to a femoral system 552 as described herein. The marking 540 may be optically detected by a camera 344. The marking 540 may be a representation that can be read by any camera.

[0153] In some embodiments, guide portion 530 may include an anti-rotation feature that limits rotation, such as by allowing post 532 to extend in only one orientation through guide portion 530 of mounting block 522. In some embodiments, components of the actuation system allow post 532 to extend in only one orientation through guide portion 530 of mounting block 522. Post 532 and / or guide portion 530 may include a mechanism to reduce or prevent rotation. In some embodiments, the shape of post 532 can reduce or prevent rotation.

[0154] 15A-15D are diagrams illustrating the actuation system of system 510. FIG. 15E is a perspective view illustrating post 532. System 510 may include a differential system that allows movement between tibial system 512 and femoral system 552. The actuation system may be positioned anywhere within system 510. In the illustrated embodiment, tibial system 512 may house certain components of the actuation system. The actuation system may include post 532. Post 532 may connect tibial system 512 and femoral system 552.

[0155] The actuation system may include an adjustment device 536. The adjustment device 536 may be located at least partially within the mounting block 522. The adjustment device 536 may extend from the mounting block 522 to allow a user to move the adjustment device 536. Figure 14B illustrates one positional relationship between the adjustment device 536 and the mounting block 522.

[0156] The adjustment device 536 can be configured to apply a distraction force between the tibial system 512 and the femoral system 552. The adjustment device 536 can be configured to maintain the position between the tibial system 512 and the femoral system 552. The adjustment device 536 can be configured to maintain the position of the post 532 relative to the mounting block 522. The adjustment device 536 can be configured to apply a force in the range of 150 N to 200 N. Adjustment device 536 can be configured to apply a force of 50 N, 60 N, 70 N, 80 N, 90 N, 100 N, 110 N, 120 N, 130 N, 140 N, 150 N, 160 N, 170 N, 180 N, 190 N, 200 N, 210 N, 220 N, 230 N, 240 N, 250 N, 260 N, 270 N, 280 N, 290 N, or 300 N, or any range of forces including two or more of these values. Adjustment device 536 can be configured to translate post 532 relative to mounting block 522 when actuated by a user.

[0157] In some embodiments, the adjustment device 536 can include a pinion configured to interact with the rack 534 of the post 532. In some embodiments, the adjustment device 536 can include a drive pinion. The post 532 can be substantially straight along its length. The rack 534 can extend along an edge of the post 532. The rack 534 can extend along the entire length of the post 532, or along a portion thereof. The adjustment device 536 can interact with the rack 534 such that rotation of the adjustment device 536 causes translation of the post 532. The adjustment device 536 can be free to rotate within the mounting block 522. The adjustment device 536 can be prevented from translating within the mounting block 522. Other configurations are also contemplated. The adjustment device 536 can include any mechanism that allows for relative movement, such as a gear, detent, pawl, pinion, screw, ramp, rack, etc. Post 532 may include any corresponding mechanism that allows for relative movement, such as gears, detents, pawls, pinions, screws, ramps, racks, etc. Adjustment device 536 may include any mechanical mechanism that can cause translational movement of post 532 when actuated.

[0158] In some embodiments, rotating the adjusting device 536 can cause translation of the post 532. In some embodiments, translating the adjusting device 536 can cause translation of the post 532. The adjusting device 536 can include an interface 538 that can engage with a driver. The interface 538 can allow a user to rotate or translate the adjusting device 536. The interface 538 can include a recess or protrusion. In some embodiments, the interface 538 can be a hexagonal recess. The interface 538 can allow a driver to rotate the adjusting device 536, as described herein. Other configurations of the interface 538 are also contemplated.

[0159] The actuation system may include a catch 548. The catch 548 may be located at least partially within the mounting block 522. In some embodiments, the catch 548 may extend from the mounting block 522 to allow a user to adjust the catch 548. In some embodiments, the catch 548 may be housed within the mounting block 522 so that it is out of reach of a user. Figure 14B illustrates one positional relationship between the catch 548 and the mounting block 522.

[0160] The stopper 548 can be configured to provide incremental positioning between the tibial system 512 and the femoral system 552. The stopper 548 can be configured to provide precise positioning of the post 532 relative to the mounting block 522. The stopper 548 can be configured to allow positioning in 1 mm increments. The stopper 548 can be configured to allow positioning in increments of 0.25 mm, 0.5 mm, 0.75 mm, 1 mm, 1.25 mm, 1.5 mm, 1.75 mm, or 2 mm, or any range of increments including two or more of these values. The stopper 548 can be configured to allow adjustment of the position of the post 532 relative to the mounting block 522.

[0161] In some embodiments, the catch 548 can be a pawl configured to interact with a ratchet 550 on the post 532. In the illustrated embodiment, the catch 548 is a spring-loaded pawl. In some embodiments, the catch 548 can be biased toward engagement with the ratchet 550. The post 532 can be substantially straight along its length. The ratchet 550 can extend along an edge of the post 532. The ratchet 550 can extend along the entire length of the post 532 or along a portion thereof. The catch 548 can interact with the ratchet 550 such that actuation of the catch 548 can incrementally change the position of the post 532. The catch 548 can be free to move within the mounting block 522. The catch 548 can be prevented from translating within the block 522. Other configurations are contemplated. Detent 548 may include any mechanism that allows for relative movement, such as a gear, detent, pawl, pinion, screw, ramp, rack, etc. Post 532 may include any corresponding mechanism that allows for relative movement, such as a gear, detent, pawl, pinion, screw, ramp, rack, etc. Detent 548 may include any mechanical mechanism that can cause translational movement of post 532 when actuated. In some embodiments, detent 548 can allow for movement of post 532 in one direction. In some embodiments, detent 548 can allow for movement of post 532 in both directions.

[0162] The catch 548 can interact with the ratchet 550 to maintain the translation of the post 532 at a stepped position. The catch 548 can be configured to slide along the teeth of the ratchet 550 as the user activates the adjustment device 536. When the user stops actuating the adjustment device 536, the catch 548 can maintain the position of the post 532. An advantage of the catch 548 is that it allows for finer adjustment of the post 532 than the adjustment device 536. In some embodiments, the gear or teeth of the ratchet 550 can be smaller than the gear or teeth of the rack 534. An advantage of the catch 548 is that it prevents slippage of the adjustment device 536 when the user stops actuating the adjustment device 536. Without the catch 548, the gear of the adjustment device 536 could slip the distance between engaging the bottom surface of the gear of the rack 534 and engaging the top surface of the adjacent gear of the rack 534. An advantage of catch 548 is that it limits movement in one or more directions. In some embodiments, when catch 548 engages with ratchet 550, it can limit translational movement of post 532 in one direction. In some embodiments, when catch 548 engages with ratchet 550, it can limit translational movement of post 532 in both directions. Additionally or alternatively, the contact between catch 548 and ratchet 550 can provide a force (e.g., a frictional force) that can hold post 532 in a desired position until adjustment device 536 is turned again.

[0163] In some embodiments, the catch 548 may automatically engage the ratchet 550 regardless of movement of the adjusting device 536. In some embodiments, the catch 548 is pushed or biased by a spring into engagement with the ratchet 550. In some embodiments, the catch 548 may be biased to slide along the ratchet 550 when the adjusting device 536 is actuated. In some embodiments, the catch 548 may be biased to maintain its position along the ratchet 550 when the adjusting device 536 is deactuated. In some embodiments, the catch 548 may be user-controlled. In some embodiments, the catch 548 may be engaged or disengaged from the ratchet 550 by the user interacting with an interface (not shown). In some embodiments, the catch 548 is out of reach or controllable by the user.

[0164] In some embodiments, the user may receive feedback related to the movement of the post 532 relative to the detent 548. For example, the system 510 may provide the user with audio, tactile, and / or visual feedback indicating the degree or range that the post 532 has moved. In some embodiments, the detent 548 provides audio feedback. In some embodiments, the detent 548 provides tactile feedback. In some embodiments, the user may hear and / or feel the detent 548 contact the ratchet 550 as the post 532 moves upward, downward, or both. This contact may produce one or more clicks. In some embodiments, the user may see a scale or other marking on the post 532 related to the position of the detent 548. Other feedback schemes are also contemplated.

[0165] The actuation system may include a post 532. The post 532 may be located at least partially within the mounting block 522. In some embodiments, the post 532 may extend from the mounting block 522 to allow the post 532 to translate relative to the mounting block 522. Figure 14B illustrates one positional relationship between the post 532 and the mounting block 522.

[0166] The post 532 may include an upper portion 542. In some embodiments, the upper portion 542 can be configured to move within the mounting block 522. The upper portion 542 may include a rack 534. The upper portion 542 may include a ratchet 550. The upper portion 542 may have a round cross-sectional shape. The post 532 may include a lower portion 546. The lower portion 546 can have any cross-sectional shape, including a cross-sectional shape other than round. In the illustrated embodiment, the lower portion 546 may have a square cross-sectional shape. The post 532 may include a window 544. The upper portion 542 may be above the window. The lower portion 546 may include the window 544.

[0167] In some embodiments, the post 532 may include one or more markings 540. The markings 540 may be located on a lower portion 546. The lower portion 546 may include at least one flat side for placement of the markings 540. The markings 540 may indicate the position of the post 532. By reading one or more readings on the markings 540, the system 510 can determine the distance the post 532 has traveled. In some embodiments, the markings 540 may be graduations. In some embodiments, the markings 540 may be captured by the camera 344. The post 522, or a portion thereof, that extends beyond the mounting block 522 may include the markings 540. The markings 540 may be aligned with the camera 344 of the reference sensor device 16. The camera 344 may capture an image of the markings 540. The image of the markings 540 may be analyzed to determine the initial positions of the tibial system 512 and the femoral system 552. Images of the markings 540 can be captured and analyzed at different times during the procedure. The markings 540 can indicate the distraction distance between the tibial system 512 and the femoral system 552.

[0168] FIG. 16A illustrates movable interface 600. Movable interface 600 can be configured to slide relative to mounting block 522. In some embodiments, movable interface 600 can include a surface 602 configured to abut against the patient's skin. In some embodiments, surface 602 of movable interface 600 can be configured to abut against an anatomical landmark. In some embodiments, surface 602 of movable interface 600 can include a portion configured to engage another portion of the patient's anatomy. Movable interface 600 can have any shape that allows movable interface 600 to move or slide relative to mounting block 522. Movable interface 600 can include one or more side surfaces 604, 606, 608. Movable interface 600 can include two parallel side surfaces 604, 606. Movable interface 600 can include a front side surface 608 connecting the two parallel sides. Front side surface 608 can include surface 602. Movable interface 600 can have a U-shaped configuration. The movable interface 600 may have one or more flat surfaces. In the illustrated embodiment, the movable interface 600 may include three flat sides. In the illustrated embodiment, the movable interface 600 may include three outer surfaces, including two outer surfaces and one anterior outer surface. The anterior outer surface may be configured to contact the patient's anatomy.

[0169] In Figure 16B, the front cover of mounting block 522 has been removed to show the interior of mounting block 522. Movable interface 600 can stabilize mounting block 522 relative to the tibia. Movable interface 600 can be located at least partially within mounting block 522. In some embodiments, movable interface 600 can extend from mounting block 522 to allow movable interface 600 to translate relative to mounting block 522. Figure 16B shows one positional relationship between movable interface 600 and mounting block 522. Movable interface 600 can be configured to slide within mounting block 522.

[0170] 16B illustrates a movable interface lock 610 associated with the movable interface 600. The movable interface lock 610 may be located at least partially within the mounting block 522. The movable interface lock 610 may include a turnbuckle 612 including two segments with opposite threads. Each end of the turnbuckle 612 engages a threaded end of a shoulder screw 614. The shoulder screw 614 may include a head 616 and a shank 618. The head 616 of the shoulder screw 614 may be located proximate to the movable interface 600. In some embodiments, the shank 618 of the shoulder screw 614 may be inserted into a slot 620 in the movable interface 600 to engage the turnbuckle 612. The head 616 of the shoulder screw 614 may be located proximate to an outer surface of the movable interface 600.

[0171] The turnbuckle 612 may include a handle 622 that a user uses to actuate the turnbuckle 612. When a user translates the handle 622, the turnbuckle 612 may rotate. Rotation of the turnbuckle 612 draws each shoulder screw 614 toward the turnbuckle 612. Rotation of the turnbuckle 612 draws each shoulder screw 614 into contact with the movable interface 600. Frictional interference between the shoulder screws 614 and the movable interface 600 can reduce or prevent movement of the movable interface 600. Other configurations for locking the movable interface 600 are also contemplated. In some embodiments, only one shoulder screw 614 may be used to lock the movable interface 600. In some embodiments, only one contact point may be used to lock the movable interface 600. In some embodiments, two or more contact points may be used to lock the movable interface 600.

[0172] In some embodiments, the movable interface 600 can be configured to slide in one plane. The movable interface lock can prevent movement in that plane when the shoulder screws 614 are engaged with the movable interface 600. In the illustrated embodiment, two shoulder screws 614 are utilized, but other configurations are contemplated (e.g., one shoulder screw, three shoulder screws, four shoulder screws, six shoulder screws, etc.). In the illustrated embodiment, one shoulder screw 614 engages each side of the movable interface 600. When the shoulder screws 614 are tightened toward the turnbuckles 612, the shoulder screws 614 apply a clamping force to the movable interface 600. Other mechanisms for reducing or preventing sliding of the movable interface 600 are also contemplated.

[0173] The movable interface 600 can translate relative to the mounting block 522 before inserting the tibial baseplate 514. The movable interface 600 can limit the insertion depth of the tibial baseplate 514. The movable interface 600 can also translate relative to the mounting block 522 after inserting the tibial baseplate 514. The movable interface 600 can provide a measurement of the insertion depth of the tibial baseplate.

[0174] The movable interface 600 may include one or more markings 624. The markings 624 may indicate the length or extent of the movable interface 600. The markings 624 may indicate the insertion depth of the system 510. The markings 624 may indicate the insertion depth of the tibial baseplate 514. The markings 624 may include scales. The markings 624 may include machine-readable scales. The markings 624 may include scales visible to the user. The mounting block 522 may include indicia such as arrows to direct the user's eyes to the markings 624. The markings 624, such as numbers on a scale, may be visible to the user as the movable interface 600 translates toward the user's leg. In some embodiments, the markings 624 may range from 0 mm to 30 mm. The markings 624 may include distance measurements of 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, or 30 mm, or a range of two or more of these values, etc.

[0175] 2. Femoral System 17A and 17B illustrate a femoral system 552. The femoral system 552 can include any of the features of the femoral systems described herein, including the femoral system 352. The femoral system 552 can include a femoral baseplate 554. The femoral baseplate 554 can include a first surface 558 configured to be positioned relative to a portion of the femur. For example, the first surface 558 of the femoral baseplate 554 can be configured to engage the bottom of a bony landmark, such as a femoral condyle. The femoral baseplate 554 can include a second surface 556 opposite the first surface 558 positioned on the tibia.

[0176] The femoral system 552 may include an extension member 560. In the illustrated embodiment, the extension member 560 is substantially straight. The femoral system 552 may include an interface 568. The extension member 560 may extend between the interface 568 and the femoral baseplate 554. The interface 568 may include a pin or a pivot. The interface 568 may allow the extension member 560 to rotate relative to the tibial baseplate 514. The interface 568 may allow the femoral baseplate 554 to rotate relative to the tibial baseplate 514. The interface 568 may be positioned in the center of the femur and / or tibia. The interface 568 may be aligned with an anatomical feature such as the intercondylar notch, Whiteside's line, or other visible landmark indicating or related to the mechanical axis of the femur. In some embodiments, the femoral baseplate 554 and the interface 568 can be rotatably coupled such that rotation of the femoral baseplate 554 causes a corresponding rotation of the interface 568. In some embodiments, the femoral baseplate 554 and the interface 568 can be rotatably coupled via an extension member 560.

[0177] The femoral system 552 may include a post mount 566. The extension member 560 may position the post mount 566 away from the knee joint. The femoral system 552 may include a post 532 as described herein. In some embodiments, the post mount 566 may be coupled to the post 532. In some embodiments, the post mount 566 may be integrally or monolithically formed with the post 532. In some embodiments, the post mount 566 and the post 532 comprise a unitary structure. Translation of the post 532 may correspondingly translate the post mount 566, as described herein. Translation of the post 532 may correspondingly translate the femoral base plate 554. Translation of the post 532 may correspondingly translate the extension member 560. Translation of the post 532 may correspondingly translate the interface 568. Translation of the post 532 may correspondingly translate other components of the femoral system 552.

[0178] In some embodiments, the extension member 560 can extend into the post mount 566. As described herein, the extension member 560, the femoral base plate 554, and the interface 568 can comprise a unitary structure such that rotation of the femoral base plate 554 causes the interface 568 to rotate accordingly. The post mount 566 can be coupled to the extension member 560 to allow the extension member 560 to rotate relative to the post mount 566. The post mount 566 can be coupled to the femoral base plate 554 via the extension member 560. The post mount 566 can be coupled to the femoral base plate 554 to allow the femoral base plate 554 to rotate relative to the post mount 566. The post mount 566 can be coupled to the interface 568 to allow the interface 568 to rotate relative to the post mount 566.

[0179] The post mount 566 may include an attachment mechanism 570. The attachment mechanism 570 may allow one or more guides or other instruments to be attached to the system 510. The attachment mechanism 570 may be parallel to the tibial baseplate 514. The attachment mechanism 570 may be coupled to the post 532 via the post mount 566. In some embodiments, the attachment mechanism 570 remains in position even when the femoral baseplate 554 is rotated. The attachment mechanism 570 may be decoupled from rotation of the extension member 560. The attachment mechanism 570 may be decoupled from rotation of the femoral baseplate 554.

[0180] The interface 568 may include a second coupler 574. The second coupler 574 may be configured to couple with the surgical orienting device 14 and / or the reference sensor device 16. The second coupler 574 may include any of the features of the couplers described herein. In some embodiments, the second coupler 574 may be positioned on a front surface of the interface 568. In some embodiments, the second coupler 574 may be positioned such that a longitudinal axis of the second coupler 574 is aligned or parallel with the femoral baseplate 554.

[0181] 13E , in some embodiments, as the femoral baseplate 554 rotates relative to the tibial baseplate 514, the interface 568 rotates relative to the tibial baseplate 514. In some embodiments, as the femoral baseplate 554 rotates relative to the tibial baseplate 514, the surgical orienting device 14 rotates relative to the tibial baseplate 514. In some embodiments, as the femoral baseplate 554 translates relative to the tibial baseplate 514 via the post 532, the interface 568 translates via the translation of the post mount 566. In some embodiments, as the femoral baseplate 554 translates relative to the tibial baseplate 514 via the post 532, the surgical orienting device 14 translates relative to the tibial baseplate 514. FIG. 13E is a perspective view illustrating the system 510.

[0182] The femoral system 552 may include a bracket 576. The second coupler 574 may be configured to couple with the bracket 576. The surgical orientation device 14 may be configured to couple with the bracket 576. The bracket 576 may include additional or alternative couplers as described herein.

[0183] 13E, 18A, and 18B, femoral system 552 may include a resection guide 580. Post mount 566 may include an attachment mechanism 570. Attachment mechanism 570 may be a recess or protrusion that couples to the resection guide. Attachment mechanism 570 may allow for a quick connection between femoral system 552 and resection guide 580. Other manners of coupling resection guide 580 to post mount 566 are also contemplated.

[0184] The resection guide 580 may include one or more notches 582. In some embodiments, each notch 582 may define a right-angle cutout. The notches 582 may extend the entire length of the resection guide 580. In some embodiments, each notch 582 may define a step on the resection guide 580. While the multiple notches 582 forming five steps are shown, different numbers, sizes, shapes, and / or locations of notches 582 may be used. The notches 582 may be spaced at any interval, such as 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc. In some embodiments, the notches 582 on the right side of the resection guide 580 correspond to the notches 582 on the left side of the resection guide 580. In some embodiments, each notch 582 is aligned or coaxial with another notch 582.

[0185] The resection guide 580 may include one or more markings 588. The markings 588 may indicate a value relative to the corresponding notch 582. The markings 588 may indicate a distance measurement relative to the notch 582. The markings 588 may range from 8 mm to 16 mm. The markings 588 may indicate a distance of 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, or 30 mm, or any range of these measurements. The markings 588 may be used as a guide for the femoral cut by indicating the distance from the tibial resection. In some embodiments, the markings 588 on the right side of the resection guide 580 correspond to the markings 588 on the left side of the resection guide 580. In some embodiments, each notch 582 has one marking 588. In some embodiments, each notch 582 has a corresponding notch 582 with the same marking 588.

[0186] In some methods, when the system 510 distracts one or more distal femoral condyles during a knee replacement procedure, a user can mark the femur at the notch 582. In some methods, a user may mark with a dot on the right side of the resection guide 580 and mark with a dot the corresponding notch 582 with the same marking 588 on the left side of the resection guide 580. In some methods, a user may mark with a line on the right side of the resection guide 580 and mark with a line the corresponding notch 582 with the same marking 588 on the left side of the resection guide 580. In some methods, a user may mark with a cross line on the right side of the resection guide 580 and mark with a cross line the corresponding notch 582 with the same marking 588 on the left side of the resection guide 580. In some embodiments, a user can remove the resection guide 580. In some embodiments, a user can connect the markings on the femur to form a line. In some methods, this line may serve as a guide for posterior resection.

[0187] The notches 582 can be spaced apart in one or more patterns. In some embodiments, the notches 582 can be spaced in incremental increments. The notches 582 can be evenly spaced or irregularly spaced. The notches 582 can indicate the distance to the tibial baseplate 514 via markings 588. The notches 582 can also indicate the distance to the resected tibial surface. In some embodiments, one or more parallel rows of notches 582 are provided. These rows can be parallel to the tibial baseplate 514 and / or the resected tibial surface. Such one or more parallel rows of notches 582 can allow a user to mark a line for a posterior resection, as described herein. Such one or more rows of notches 582 can allow a user to mark a resection line a known distance from the tibial resection. This row or rows of notches 582 can be used to ensure that the posterior femoral cut is parallel to the tibial cut.

[0188] In some embodiments, the resection guide 580 may provide notches 582 for even measurements (e.g., 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, etc.). In some embodiments, the resection guide 580 may provide notches 582 for odd measurements (e.g., 7 mm, 9 mm, 11 mm, 13 mm, 15 mm, 17 mm, etc.). The resection guide 580 may include a first portion extending in a first direction. The resection guide 580 may include a second portion extending in a second direction different from the first direction. In some embodiments, the resection guide 580 has two orthogonal or substantially orthogonal portions. The first portion may be configured to extend proximal to the femur, and the second portion may be configured to extend away from the femur. The first and second portions may be substantially flat or plate-like. The resection guide 580 may be L-shaped. The second portion may include a slot 584 configured to receive a thumbscrew 586. The thumbscrew 586 may removably extend the entire length of the resection guide 580. The thumbscrew 586 allows the user to move the resection guide 580 against the femur.

[0189] The resection guide 580 may include a portion that engages with the attachment mechanism 570 of the post mount 566. The resection guide 580 may be coupled to the attachment mechanism 570 of the post mount 566 such that as the post 532 translates, the resection guide 580 translates accordingly. The system 510 may translate such that the resection guide 580 remains parallel to the tibial baseplate 514. The resection guide 580 may be a modular device. The resection guide 580 may be coupled to and detached from the attachment mechanism 570 as needed during the procedure.

[0190] Other guides are contemplated. System 510 can be utilized with any of the guides described herein. System 510 can also be utilized with a drill guide to facilitate placement of one or more pins into the distal femur. In some embodiments, system 510 can include multiple resection guides configured to couple with attachment mechanism 570. In some embodiments, the multiple resection guides can include different notches to allow for different posterior resection cuts. Other devices can be attached to attachment mechanism 570. Other configurations for coupling resection guide 580 to system 510 are also contemplated.

[0191] 13E and 18A , the resection guide 580 can be maintained in a rotated orientation relative to the tibial baseplate 514. The resection guide 580 can be coupled to or decoupled from the attachment mechanism 570. The attachment mechanism 570 can be coupled to the post mount 566. In some embodiments, the post mount 566 can maintain the position of the resection guide 580 relative to the tibial baseplate. The post mount 566 is coupled to the post 532 in a manner that reduces or prevents rotation of the post mount 566 relative to the post 532. The post 532 is coupled to the tibial baseplate 514 via the tibial mounting block 522 in a manner that reduces or prevents rotation of the post 532 relative to the tibial baseplate 514. The resection guide 580 can be rotationally stable relative to the tibial baseplate 514. The resection guide 580 can be rotatably coupled to the tibial baseplate 514. The resection guide 580 can be parallel to the tibial baseplate 514. The resection guide 580 may be parallel to the tibial resection.

[0192] 13E and 18A , the femoral baseplate 554 can rotate relative to the tibial baseplate 514. The femoral baseplate 554 can be coupled to an interface 568. The surgical orientation device 14 can be coupled to the interface 568. The surgical orientation device 14 can measure the rotation of the femoral baseplate 554. In some embodiments, the femoral baseplate 554 can rotate relative to the resection guide 580. In some embodiments, the femoral baseplate 554 can rotate relative to the post mount 566. In some embodiments, the femoral baseplate 554 can rotate relative to the post 532.

[0193] The resection guide 580 can be rotationally decoupled from the femoral baseplate 554. The femoral baseplate 554 can be at any angle relative to the resection guide 580. The femoral baseplate 554 can be at any angle relative to the tibial resection. In some embodiments, the rotation of the femoral baseplate 554 is independent of the positioning of the resection guide 580. The resection guide 580 can translate relative to the tibial baseplate 514. The resection guide 580 can translate as the post 532 translates. The system 510 can provide alignment of the resection guide 580 with respect to the tibial resection, as described herein.

[0194] 3. Overview of distraction 19A-19H are additional views showing the system 510 coupled to a patient's tibia and femur. FIG. 19A is a perspective view showing the position of the system 510. FIG. 19B is a front view showing the position of the system 510. The femoral system 552 may include a bracket 576 as described herein. The bracket 576 may allow a user to view the joint space. The bracket 576 may move the surgical orienting device 14 inferiorly relative to the femoral baseplate 554. The surgical orienting device 14 may be positioned outside the joint space. The user may view the tibial baseplate 514 and the femoral baseplate 554. The bracket 576 may shift the surgical orienting device 14 laterally.

[0195] In some embodiments, the bracket 576 may be generally L-shaped. The bracket 576 may include a first portion 562 extending from the second coupler 574. The first portion may extend in a first direction. The bracket 576 may include a second portion 564. The second portion 564 may extend in a second direction, which may be different from the first direction. In some embodiments, the first portion 562 may extend horizontally. In some embodiments, the second portion may extend vertically. In some embodiments, the second portion 564 may extend orthogonally or nearly orthogonally to the first portion 562. In some embodiments, the first portion 562 is linear or nearly linear. In some embodiments, the first portion 562 is non-linear, e.g., having linear segments and diagonal segments. In some embodiments, the second portion 564 is linear or nearly linear. In some embodiments, the first portion 562 can be integral or monolithically configured with the second portion 564. In some embodiments, the first portion 562 can extend at an angle from the second coupler 574, resulting in an offset. In some embodiments, the first portion 562 can extend straight from the second coupler 574.

[0196] Advantages include the bracket 576 being able to position the surgical orienting device 14 below the tibial resection. Advantages include the bracket 576 being able to position the surgical orienting device 14 outside of the field of view of the joint space, enhancing visibility from the perspective of FIG. 19A , for example. Advantages include the bracket 576 being able to position the surgical orienting device 14 offset from the reference sensor device 16. Advantages include the bracket 576 being able to position the surgical orienting device 14 offset from the interface 538 of the adjustment device 536. Advantages include the bracket 576 being able to position the surgical orienting device 14 below the resection guide 580. The surgical orienting device 14 can be positioned to line up with the line of sight of the resection guide 580. Other configurations are also contemplated.

[0197] In some embodiments, the longitudinal axis of the reference sensor device 16 may be aligned with the longitudinal axis of the tibia. The axis of the tibia may be perpendicular to the tibial resection. In some embodiments, the reference sensor device 16 may be aligned with a mechanical axis associated with the knee joint, such as the mechanical axis of the tibia or leg. In some embodiments, the longitudinal axis of the surgical orienting device 14 may be offset from the longitudinal axis of the tibia. In the illustrated embodiment, the surgical orienting device 14 may be offset from a mechanical axis associated with the knee joint, such as the mechanical axis of the tibia or leg. The longitudinal axes of the surgical orienting device 14 and the reference sensor device 16 may be parallel. The longitudinal axes of the surgical orienting device 14 and the reference sensor device 16 may be offset in the coronal plane. The longitudinal axes of the surgical orienting device 14 and the reference sensor device 16 may be offset in the sagittal plane. The longitudinal axes of the surgical orienting device 14 and the reference sensor device 16 may be misaligned in the transverse plane.

[0198] FIG. 19C is a perspective view illustrating the position of the tibial system 512 and post 532. As described herein, the upper portion 542 of the post 532 can have a substantially round or circular cross-sectional shape, and the guide portion 530 of the mounting block 522 can have a corresponding substantially round or circular cross-sectional shape. The round or circular cross-sectional shape can allow for more precise placement of the markings 540 relative to the camera 344 of the reference sensor device 16. The round or circular cross-sectional shape can allow the tibial baseplate 514 and the femoral baseplate 554 to maintain alignment during distraction. The round or circular cross-sectional shape can reduce tolerances between the components of the system 510. The lower portion 547 of the post 532 can have any cross-sectional shape.

[0199] 19D is a cross-sectional view showing the interior of the mounting block 522. The adjusting device 536 and the catch 548 can be in diametrically opposed positions. The adjusting device 536 and the catch 548 can be spaced apart. The adjusting device 536 can be configured to engage with the rack 534, which can have a larger gear than the ratchet 550 with which the catch 548 engages. The adjusting device 536 can be capable of applying a force. The applied force can be in the range of 150 N to 200 N. The adjusting device 536 and the rack 534 can be configured to apply any force sufficient to distract the joint. The teeth of the adjusting device 536 and the teeth of the rack 534 can be configured to apply a desired force to the joint. The catch 548 can allow for fine positioning. The ratchet 550 can have a smaller tooth pitch than the rack 534. The ratchet 550 can have a tooth pitch of 1 mm. The catch 548 can maintain the position of the post 532 when the user deactivates the adjustment device 536 .

[0200] FIG. 19D illustrates connections between other components of system 510. Post 532 can be coupled to post mount 566. Translation of post 532 can cause post mount 566 to translate accordingly. Resection guide 580 can be coupled to post mount 566 via attachment mechanism 570. In some embodiments, rotation between post 532 and post mount 566 is limited or prevented. In some embodiments, rotation between post 532 and resection guide 580 is limited or prevented. In some embodiments, post 532 and post mount 566 can function as a single unit. In some embodiments, post 532 and post mount 566 are integrally formed. In some embodiments, resection guide 580 is removably attached to attachment mechanism 570 of post mount 566. In some embodiments, when resection guide 580 is coupled to attachment mechanism 570, post 532, post mount 566, and resection guide 580 form a single unit. In some embodiments, the resection guide 580 can be configured to only translate linearly with translation of the post 532 .

[0201] 19D illustrates a connection between an extension member 560 and a post mount 566. The extension member 560 can be coupled to a femoral base plate 554. The extension member 560 can be coupled to an interface 568 (see FIG. 17A). When the femoral base plate 554 rotates, the extension member 560 can rotate accordingly. The post mount 566 allows the femoral base plate 554 and the extension member 560 to rotate relative to the post mount 566.

[0202] 19E and 19F illustrate the tibial system and the movable interface 600. FIG. 19E shows the movable interface 600 spaced apart from the tibia. FIG. 19F shows the movable interface 600 engaged with the tibia. The movable interface 600 may include a surface 602 that contacts the user's skin. The movable interface 600 may be configured to move forward and backward within the mounting block 522 (corresponding to backward and anterior movements relative to the patient). The movable interface 600 may slide forward to rest against the patient's skin. A movable interface lock may also be used to reduce or prevent sliding of the movable interface 600. The movable interface lock may include a handle 622 that can rotate the turnbuckle 612 within the mounting block 522 as described herein. The frictional force of the movable interface lock may limit sliding of the movable interface 600.

[0203] The movable interface 600 may include markings 624. The markings 624 may provide indications of the insertion depth of the system 510. The movable interface 600 may limit or prevent further insertion due to interference between the movable interface 600 and the patient's anatomy. The movable interface 600 may increase the stability of the system 510. The movable interface 600 may provide additional points of contact between the system 510 and the patient. The movable interface 600 may limit the insertion depth in a flexed state. The movable interface 600 may limit the insertion depth in an extended state.

[0204] FIG. 19G is a perspective view illustrating one or more notches 582 on a resection guide 580. The notches 582 can indicate the distance to the tibial resection. The resection guide 580 can be a plate configured to rest on the resected femur. Each notch 582, or a portion of a notch 582, can include a corresponding marking 588. The notches 582 can allow a user to draw a line to indicate the location of the posterior cut. In some methods, a user can mark the femur using one or more notches 582. In some methods, a user can then draw a line connecting the marks on the femur. This line can correspond to the resection plane.

[0205] FIG. 19H is a perspective view illustrating system 510 and torque driver 650. Torque driver 650 can engage with adjusting device 536. Interface 538 of adjusting device 536 can be located on mounting block 522. Torque driver 650 can allow adjusting device 536 to rotate. In some embodiments, rotation of torque driver 650 can rotate adjusting device 536 accordingly. In some embodiments, translation of torque driver 650 can rotate adjusting device 536 accordingly. In some embodiments, movement or translation of torque driver 650 can rotate adjusting device 536 accordingly. While FIG. 19H shows torque driver 650, other drivers are contemplated.

[0206] The system 510 can facilitate a posterior resection. The posterior resection can allow for positioning of the implant. The implant manufacturer may supply a guide configured to be attached to the femur after the posterior resection. The anterior cut and / or chamfer cut can be referenced to the posterior resection. The positioning of the drill guide and cutting block can also be referenced to the posterior resection. The notch 582 can aid in marking the femur for the posterior resection cut. The resection guide 580 can allow the user to mark the femur at a specific distance from the tibial resection for the posterior resection cut.

[0207] The surgical orientation device 14 can measure the distance of the posterior resection cut. The surgical orientation device 14 and the reference sensor device 16 can communicate to determine the distraction distance. In some methods, the camera 344 of the reference sensor device 16 can capture a distance measurement from the markings 540 on the post 532. In some embodiments, the reference sensor device 16 can transmit this distance measurement to the surgical orientation device 14. In some embodiments, the reference sensor device 16 can transmit an image from the camera 344 to the surgical orientation device 14.

[0208] The system 510 can be configured to be inserted into the joint space. In some embodiments, the tibial baseplate 514 can be adjacent to the femoral baseplate 554 during insertion. The surgical orientation device 14 can be coupled to the bracket 576. The reference sensor device 16 can be coupled to the mounting block 522. The femoral system 552 can be moved up and down (e.g., proximally and distally) relative to the tibial system 512 by the adjustment device 536. The adjustment device 536 can be used to distract the femur relative to the tibia. The adjustment device 536 can be actuated by a user to translate the post 532 within the mounting block 522. The catch 548 can maintain the position of the post 532 when the user deactivates the adjustment device 536. The catch 548 can prevent the adjustment device 536 from slipping. Moving the post 532 can move the femoral system 552 relative to the tibial system 512 accordingly. The femoral system 552 translates as a unit with the post 532. The translation of the post 532 allows the femoral baseplate 554 to move relative to the tibial baseplate 514 to increase or decrease the gap between the femoral baseplate 554 and the tibial baseplate 514.

[0209] In some embodiments, the femoral baseplate 554 can rotate relative to the tibial baseplate 514. The femoral baseplate 554 can rotate in a medial / lateral direction. This rotation allows the femoral baseplate 554 to engage both femoral condyles regardless of their size or orientation or the spacing between the femoral condyles. This rotation allows the femoral baseplate 554 to be inserted through a relatively narrow incision in a low-back orientation and then rotated within the joint space to engage the femoral condyles.

[0210] The surgical orientation device 14 can be coupled to the femoral baseplate 554. The surgical orientation device 14 can provide indications indicating the degree of rotation of the femoral baseplate 554. The surgical orientation device 14 can be coupled to the femoral baseplate 554 such that as the femoral baseplate 554 rotates, the surgical orientation device 14 can rotate accordingly. The surgical orientation device 14 can include a display 26 that can indicate the angle of rotation of the surgical orientation device 14. In some embodiments, the surgical orientation device 14 and the reference sensor device 16 determine the angle of the surgical orientation device 14. In some embodiments, one or more sensors within the surgical orientation device 14 determine the angle of the surgical orientation device 14. As a non-limiting example, the one or more sensors may determine a position or orientation relative to zero gravity. The surgical orientation device 14 can measure the angle of the femoral baseplate 554. This angle may correspond to the angle between the femoral baseplate 554 and the tibial baseplate 514.

[0211] In some embodiments, the soft tissue around the knee joint can be released. In some embodiments, the soft tissue around the knee joint can be released when the knee is in extension. In some embodiments, the soft tissue around the knee joint can be released only when the knee is in extension. In some embodiments, the soft tissue around the knee joint can be released when the knee is in flexion. In some methods, the user can remodel the soft tissue by cutting one or more ligaments. Changing the soft tissue can change the rotation of the femoral baseplate 554. Changing the rotation of the femoral baseplate 554 can change the rotation of the surgical orienting device 14 accordingly. The surgical orienting device 14 can display the angle of the surgical orienting device 14 as it rotates. In some embodiments, the user can release one or more ligaments in the knee joint before or during knee distraction to facilitate simultaneous symmetry of the gap. In some embodiments, the user can release one or more ligaments within the knee joint before or during knee distraction to facilitate alignment of the mechanical axes. In some embodiments, the user can release one or more ligaments within the knee joint before or during knee distraction to facilitate balancing of the soft tissue and / or ligaments within the knee joint. The user can score or cut the soft tissue to adjust for knee joint laxity. In some embodiments, the user performs soft tissue balancing until the femoral baseplate 554 and the tibial baseplate 514 are parallel or nearly parallel when the knee is in extension. In some embodiments, the user performs soft tissue balancing until the femoral baseplate 554 and the tibial baseplate 514 form a desired angle.

[0212] The surgical orientation device 14 and / or the reference device 16 can be configured to measure the rotation of the surgical orientation device 14 during soft tissue balancing. The rotation of the surgical orientation device 14 is related to the relative tension of the medial and lateral soft tissues on the medial and lateral sides of the knee joint. The surgical orientation device 14 can display the rotation angle before and / or during soft tissue release. The surgical orientation device 14 can display this information on a display 26 located within the surgical field. As described herein, the surgical orientation device 14 can be positioned below the joint space. The surgical orientation device 14 can display the femoral rotation angle. In some embodiments, the surgical orientation device 14 can display the femoral rotation angle in real time. In some embodiments, the surgical orientation device 14 can display a static angle of femoral rotation, such as the femoral rotation angle at a particular time, such as when a button or other user input device 28 is activated. In some embodiments, the surgical orientation device 14 can display a dynamic angle of femoral rotation, such as the angle of femoral rotation while soft tissue is being manipulated. In some embodiments, the surgical orientation device 14 can display a target angle of femoral rotation. This target can be displayed as a graphical representation, such as a sliding scale or markings located on a target.

[0213] The surgical orientation device 14 and / or the reference device 16 can be configured to measure the distraction distance between the femoral baseplate 554 and the tibial baseplate 514. The camera 344 can capture an image corresponding to the distraction distance or otherwise read the markings 540 on the post 532. The markings 540 can be graduations that can be captured by the camera 344. The image from the camera 344 can be interpreted by either the surgical orientation device 14 or the reference sensor device 16. The surgical orientation device 14 can display the distraction distance on the display 26. In some embodiments, the surgical orientation device 14 can display the distraction distance in real time. In some embodiments, the surgical orientation device 14 can display a static distraction distance, such as the distraction distance at a particular time, for example, when a button or other user input device 28 is activated. In some embodiments, the surgical orientation device 14 can display a dynamic distraction distance, such as the distraction distance while the post 532 is moving. In some embodiments, the surgical orientation device 14 can display a target distraction distance. This target can be displayed as a graphical representation, such as a fillable bar on a bar graph, a sliding scale, or a mark located on a bullseye.

[0214] In some embodiments, the user can make the femoral cuts after distraction. Resection guide 580 can be a modular device that can be coupled to or detached from attachment mechanism 570. In some embodiments, resection guide 580 can be rotatably fixed relative to tibial baseplate 514. In some embodiments, resection guide 580 can allow the user to make one or more cuts in the femur at a selected angle (e.g., parallel) relative to tibial baseplate 514. In some embodiments, resection guide 580 can allow the user to make one or more cuts in the femur at a known distance from the resected tibia. In some embodiments, the cuts can be made with the knee in flexion.

[0215] In some methods of use, the tibia is resected prior to using system 510. For example, as described above, tibia preparation system 210 or other tibia preparation systems may be used to resect a portion or portions of the tibia so that the proximal end of the tibia has a substantially flat surface. In some methods of use, the femur is resected prior to using system 510. For example, as described above, femur preparation system 10 or other femur preparation systems may be used to resect a portion or portions of the femur so that the distal end of the femur has a substantially flat surface.

[0216] In some embodiments, the system 510 can be used when the knee is in extension. In some methods of use, after completing the tibial resection and distal femoral resection, the user flexes the knee 180 degrees and inserts the system 510. In some methods of use, the leg is positioned in full extension (not shown). The tibial baseplate 514 and the femoral baseplate 554 can be inserted into the knee joint and the knee joint can be distracted. The surgical orientation device 14 can measure the distraction distance using one or more sensors. The reference sensor device 16 can measure the distraction distance using one or more sensors. The reference sensor device 16 can also measure the distraction distance using the camera 344. The surgical orientation device 14 and / or the reference sensor device 16 can record the distraction distance when the knee is in extension. The surgical orientation device 14 and / or the reference sensor device 16 can store the distraction distance when the knee is in extension for use when the knee is in flexion. The surgical orientation device 14 and femoral baseplate 554 may rotate based on the tension on the medial and lateral sides of the knee. A user can release the ligaments when the knee is in extension based on the angle output of the surgical orientation device 14. A user can release the ligaments to reduce rotation of the femoral baseplate 554. A user can release the ligaments so that the femoral baseplate 554 is parallel to the tibial baseplate 514. A user can release the ligaments so that the femoral baseplate 554 is at a desired angle relative to the tibial baseplate 514. In some methods, soft tissue release is performed only when the knee is in extension.

[0217] In some embodiments, the system 510 can be used when the knee is in flexion. In some methods of use, after completing the tibial resection and distal femoral resection, the user flexes the knee 90 degrees and inserts the system 510. The tibial baseplate 514 and the femoral baseplate 554 can be inserted into the knee joint, and the knee joint can be distracted. The surgical orientation device 14 can measure the distraction distance using one or more sensors. The reference sensor device 16 can measure the distraction distance using one or more sensors. The reference sensor device 16 can measure the distraction distance using the camera 344. The surgical orientation device 14 and / or the reference sensor device 16 can record the distraction distance when the knee is in flexion. The surgical orientation device 14 and / or the reference sensor device 16 can compare the distraction distance when the knee is in extension to the distraction distance when the knee is in flexion. The surgical orientation device 14 and femoral baseplate 554 may rotate based on the tension on the medial and lateral sides of the knee. The surgical orientation device 14 may display the rotation angle of the femoral baseplate. The resection guide 580 may be parallel to the tibial resection. After distracting the joint, the user may mark the resection line for the posterior cut. In some methods, the user may balance the flexion and extension gaps. In some methods, the user may balance the flexion and extension gaps by selecting the notch 582 on the resection guide 580 that corresponds to the extension gap.

[0218] As described herein, the camera 344 can capture images related to the distraction distance. The distraction distance may correspond to the distraction distance between the tibia and the femur. The system 510 can calculate an anterior-posterior shift that equalizes the flexion gap and the extension gap. In some embodiments, the surgical orientation device 14 can display the extension distraction distance and the flexion distraction distance. In some embodiments, the surgical orientation device 14 can display the static distraction distance obtained from measurements taken when the knee was in extension and the dynamic distraction distance when the knee was in flexion. In some methods, the user can compare the extension distraction distance to the flexion distraction distance. In some methods, the surgical orientation device 14 can output the difference between the extension gap and the flexion gap.

[0219] In some knee procedures, the posterior femoral cut (PFC) is performed while the knee is in flexion. In some methods of use, a user can utilize a resection guide 580 to perform the posterior cut. The resection guide 580 can include notches corresponding to various gap measurements. The resection guide 580 can provide a guide for marking the posterior resection to achieve the appropriate anterior-posterior shift. This anterior-posterior shift can be based on an anteroposterior shift calculated by the surgical orientation device 14. The anteroposterior shift can be based on an anteroposterior shift determined by comparing the distraction distance in extension to the distraction distance in flexion. The anteroposterior shift can be the difference between the gap in extension and the gap in flexion.

[0220] The user may select a notch 582 that corresponds to the gap measured in extension. The notch 582 may include a corresponding marking 588, which may be a distance measurement. For example, if the gap in extension is 8 mm, the user may select a notch 582 that corresponds to a gap in flexion of 8 mm. The user may select from various parallel rows of notches 582 that correspond to various distances. The user may also use a row of notches 582 to make two marks on the femur. In some methods, the user may remove the resection guide 580 and draw a line connecting the marks. The user may use these marks and / or lines to make the posterior femoral cut. An anterior cut may be made relative to the posterior cut. A chamfer cut may also be made relative to the posterior cut. One or more additional cuts may be made based on the posterior femoral cut.

[0221] The system 510 can be utilized for soft tissue balancing in extension and / or flexion. The surgical orientation device 14 can display a rotation angle of the surgical orientation device 14. The rotation angle can be referenced to a reference sensor device 16. The rotation angle can be referenced to zero gravity or any other vertical or horizontal vector. The surgical orientation device 14 can display a rotation angle of the surgical orientation device 14. The surgical orientation device 14 can display a rotation angle of the surgical orientation device 14 relative to a vertical vector. The surgical orientation device 14 can display a rotation angle of the surgical orientation device 14 relative to a horizontal vector. The surgical orientation device 14 and / or the reference sensor device 16 can include one or more sensors for determining the direction of gravity. In some embodiments, the surgical orientation device 14 and / or the reference sensor device 16 can include an accelerometer.

[0222] The rotation angle of the surgical orienting device 14 may correspond to the posterior condylar angle. The system 510 may record the rotation angle in extension and / or flexion. The rotation angle of the surgical orienting device 14 may correspond to the posterior condylar angle associated with the implant or implant guide. In some embodiments, a cutting block or drill guide equipped with the implant by the implant manufacturer may be adjustable based on the posterior condylar angle. In some embodiments, an implant may be selected from a plurality of implants based on the posterior condylar angle.

[0223] The system 510 can perform one or more calculations related to the rotation angle of the surgical orientation device 14. The system 510 can perform one or more calculations related to the distraction distance. The system 510 can be utilized to provide a visual indication of the medial distraction distance. The system 510 can be utilized to provide a visual indication of the lateral distraction distance. The system 510 can be configured to measure the tension in the soft tissue on the medial and / or lateral sides of the knee joint. The surgical orientation device 14 can be configured to display the force or tension on each side.

[0224] In some embodiments, a user can release one or more ligaments within the knee joint to balance the soft tissue on the medial and / or lateral sides of the knee joint. A user can release the soft tissue when the knee joint is in extension to symmetrize the gap in extension. A user can release the soft tissue when the knee joint is in flexion to symmetrize the gap in flexion. A user can release the soft tissue when the knee is in extension or flexion to align the mechanical axes between the femur and tibia. A user can release the soft tissue to decrease the rotation angle of the surgical orienting device 14. A user can release the soft tissue to increase the rotation angle of the surgical orienting device 14. In some methods, a user can score or cut the soft tissue to adjust for knee laxity. A user can perform soft tissue balancing until the desired angle between the tibia and femur is achieved. The user may perform soft tissue balancing until the surgical orientation device 14 displays the desired angle. In some methods, the soft tissue is modified only in extension. In some methods, the soft tissue is modified only in flexion. In some methods, the soft tissue is modified in both flexion and extension. In some methods, the soft tissue is not modified.

[0225] D. Advantages The total knee arthroplasty (TKA) market is segmented. Various systems typically focus on alignment or balancing. Alignment systems perform measured resections. The resections or cuts are aligned with bony or anatomical landmarks. Then, tension is addressed. Balancing systems perform gap balancing. They balance the soft tissues or ligaments within the knee joint. Typically, a square cut is made on the balanced knee.

[0226] FIGS. 20A-20B illustrate the system 310. FIGS. 20C-20D illustrate the system 510. FIGS. 20A and 20C illustrate the systems 310, 510 in a distracted position in which the tibial system 312, 512 is separated a distance from the femoral system 352, 552. As described herein, this separation can be achieved by an actuation system including the posts 332, 532. For example, a rack and pinion can be utilized to apply force. The femoral system 352, 552 translates relative to the tibial system 312, 512 through movement of the posts 332, 532. The femoral system 352, 552 is translatably coupled to the posts 332, 532. As described herein, the femoral system 352, 552 can include post mounts 366, 566 that translate the femoral system 352, 552 with the posts 332, 532. The resection guide 580 or drill guide 380 can be coupled to the post mounts 366,566 such that the resection guide 580 or drill guide 380 translates with the femoral system 352,552.

[0227] 20B and 20D show the systems 310, 510 in a distracted and rotated position in which the tibial system 312, 512 is separated a distance from the femoral system 352, 552 and the femoral system 352, 552 is rotated relative to the tibial system 312, 512. As described herein, the femoral system 352, 552 may include a femoral baseplate 354, 554 that can be configured to rotate relative to the post 332, 532. As described herein, the femoral baseplate 354 is coupled to an extension member 360 that includes a second coupler 374. The femoral baseplate 354 and the second coupler 374 form a unitary structure configured to rotate about a rotational interface 368. As described herein, the femoral baseplate 554 is coupled to an extension member 560 that extends through a post mount 566 to an interface 568. The interface 568 includes the second coupler 574. Rotation of the femoral baseplate 554 about one axis translates to rotation of the interface 568 about a second axis. In some embodiments, the system 510 converts rotation about one axis into rotation about the other axis to improve the accuracy of the inertial sensor. The interface 568 can pivot up and down as the femoral baseplate 554 rotates. Although all components of the femoral system 552 are rotatably coupled, the interface 568 rotates about a different axis of rotation than the femoral baseplate 554.

[0228] The systems 310, 510 can be integrated with the femoral preparation system 10 and / or tibial preparation system 210 described herein. The systems 310, 510 provide a balancing solution. The systems 310, 510 integrate soft tissue balancing functionality. The systems 310, 510 are simple, streamlined systems that can be integrated into the workflow with alignment systems. The femoral preparation system 10, tibial preparation system 210, and / or system 310 enable the user to perform an aligned, balanced posterior condylar cut.

[0229] The femur preparation system 10, the tibia preparation system 210, and / or the systems 310, 510 can achieve angular precision and accuracy through inertial sensors. The femur preparation system 10, the tibia preparation system 210, and / or the systems 310, 510 utilize a surgical orientation device 14 and / or a reference sensor device 16. The surgical orientation device 14 and / or the reference sensor device 16 comprise one or more inertial sensors as described herein. The surgical orientation device 14 and / or the reference sensor device 16 comprise one or more accelerometers. The surgical orientation device 14 and / or the reference sensor device 16 comprise one or more gyroscopes.

[0230] The femoral preparation system 10, the tibial preparation system 210, and / or the system 310, 510 can apply a controlled, known distraction force. The post 332, 532 can be translated via the adjustment device 336, 536. In some embodiments, rotation of the adjustment device 336, 536 can be correlated to a known force or pressure. In some embodiments, one rotation of the adjustment device 336, 536 can correspond to a force of 40 to 50 N, and two rotations of the adjustment device 336, 536 can correspond to a force of 80 to 100 N. In some embodiments, the adjustment device 336, 536 can be configured to apply a force of 150 N to 200 N. In some embodiments, the tibial baseplate 314, 315 can include one or more sensors for measuring force. In some embodiments, the femoral baseplate 354, 554 can include one or more sensors for measuring force. The surgical orientation device 14 and / or the reference sensor device 16 can record force measurements. The surgical orientation device 14 and / or the reference sensor device 16 can store force measurements.

[0231] The femoral preparation system 10, the tibial preparation system 210, and / or the systems 310, 510 may include an intra-operative graphical user interface. The femoral preparation system 10, the tibial preparation system 210, and / or the systems 310, 510 may include a surgical orientation device 14. The surgical orientation device 14 may include a display 26. The display 26 may provide on-screen graphics of one or more parameters used during the procedure. For example, a numeric display may be provided for one or more measurements, such as flexion / extension angle, medial / lateral angle, rotation angle (e.g., rotation angle around the mechanical axis of the leg, posterior condyle angle, etc.), or distance (e.g., extension distance of the post 332, 532, etc.). The on-screen graphics may include alphanumeric text or symbols of various colors, one or more background colors, one or more icons, one or more GUI images, animations, arrows, etc. The display 26 may also provide a textual, audible, or other visual notification to the user that a current measurement is outside of a predetermined range. The surgical orientation device 14 can be controlled by a user within the surgical field. The user can view the display 26 within the surgical field. The user can interact with the surgical orientation device 14 within the surgical field (e.g., press buttons, record measurements, receive commands, interact with the user input device 28, read the display 26, etc.).

[0232] The femoral preparation system 10, the tibial preparation system 210, and / or the system 310, 510 may be open platform. The system 310, 510 may cooperate with a primary implant. A drill guide 380 may be provided by the implant manufacturer. The drill guide 380 may form an opening 382 that corresponds to the measurements of the cutting block provided by the implant manufacturer. The opening 382 may correspond to the cutting block 394 provided by the implant manufacturer. The system 310 may include the drill guide 380 for aligning the tibial resection with the universal block. The drill guide 380 may be used to create a hole for locating the cutting block 394, as described herein. The resection guide 580 may be utilized to mark a line on the femur. In some embodiments, the resection guide 580 includes notches 582 that allow a user to draw a dot, line, or check mark that corresponds to the notch 582. These marks may then be used to draw a line after removing the resection guide 580. Other configurations for drawing a resection line are also contemplated. The resection guide 580 may include one or more apertures for drawing points. The resection guide 580 may include one or more slots for drawing lines or line segments. The resection guide 580 may include one or more flat surfaces for drawing lines or line segments. Other configurations for marking the resection line are also contemplated.

[0233] The system 310, 510 can calculate, display, record, and store various measurements and / or calculations. Data can be stored throughout the procedure. Data can be stored for post-operative use. The system 310, 510 can calculate the posterior condyle angle. The system 310, 510 can display the posterior condyle angle. The system 310, 510 can record the posterior condyle angle. The system 310, 510 can store the posterior condyle angle. As described herein, the system 310, 510 can allow the reference sensor device 16 to be positioned in two or more orientations when the system 310, 510 calculates the posterior condyle angle. The system 310, 510 can allow the reference sensor device 16 to be positioned in two orthogonal orientations. The longitudinal axis of the reference sensor device 16 can be parallel to the tibial baseplate 314, 315 when the system 310, 510 calculates the posterior condyle angle. The longitudinal axis of the surgical orientation device 14 may be perpendicular to the tibial baseplate 314 when the system 310, 510 calculates the angle of the posterior condyle.

[0234] The system 310, 510 can calculate the distraction distance in extension. The system 310, 510 can display the distraction distance in extension. The system 310, 510 can record the distraction distance in extension. The system 310, 510 can store the distraction distance in extension. The system 310, 510 can calculate the distraction distance in flexion. The system 310, 510 can display the distraction distance in flexion. The system 310, 510 can record the distraction distance in flexion. The system 310, 510 can store the distraction distance in flexion. The system 310, 510 can compare the distraction distance in flexion to the distraction distance in extension. The system 310, 510 can calculate an adjustment distance if the distraction distance in flexion differs from the distraction distance in extension. The user can adjust the drill guide 380 by this adjustment distance. The user can utilize a row of parallel openings 382 separated by an adjustable distance. The user can utilize a resection guide 580 that is related to the distraction distance. The user can utilize a row of parallel notches 582 to mark a line for the posterior resection.

[0235] The system 310, 510 can calculate the medial distraction distance. The system 310, 510 can also calculate the lateral distraction distance. The medial distraction distance and the lateral distraction distance can be determined in part based on the distraction distance. The medial distraction distance and the lateral distraction distance can also be determined in part based on the angle of the posterior condyle. The system 310, 510 can display the medial distraction distance. The system 310, 510 can display the lateral distraction distance. The system 310, 510 can record the medial distraction distance. The system 310, 510 can record the lateral distraction distance. The system 310, 510 can store the medial distraction distance. The system 310, 510 can store the lateral distraction distance. The system 310, 510 can dynamically provide the medial distraction distance and / or the lateral distraction distance. The system 310, 510 can provide the medial distraction distance and / or the lateral distraction distance in real time.

[0236] The system 310, 510 can perform cut verification. The system 310, 510 can perform cut verification for a distal femoral cut (DFC). A DFC involves removing the distal (i.e., lower) portion of the femur. The system 310, 510 can perform cut verification for a posterior femoral cut (PFC). A PFC involves removing a portion of the posterior condyle. The system 510 can be utilized to mark the femur in relation to the PFC. The system 310, 510 can perform cut verification for one or more cuts in the femur. The system 310, 510 can perform cut verification for one or more cuts in the tibia.

[0237] The systems 310, 510 can utilize the surgical orientation device 14 and / or the reference sensor device 16 of the femoral preparation system 10 and the tibial preparation system 210 described herein. The systems 310, 510 can provide a mounting for the surgical orientation device 14. The systems 310, 510 can provide a mounting for the reference sensor device 16. The systems 310, 510 can provide a mounting for the drill guide 380. The systems 310, 510 can allow for the mounting of a resection guide 580. The systems described herein can be compatible with any of the subsystems described herein, including the guides described herein. The drill guide 380 can be coupled to the tibial baseplate 314. The drill guide 380 can be rotationally independent from the femoral baseplate 354. The drill guide 380 can guide the drill holes to the specifications of the universal block. The drill guide 380 can guide the cutting block to be parallel with the tibial resection. The resection guide 580 can be coupled to the tibial baseplate 514. The resection guide 580 can be rotationally independent from the femoral baseplate 554. The resection guide 580 can guide the posterior cut to be parallel with the tibial resection.

[0238] The system 310, 510 can apply a distraction force. The system 310, 510 can provide mechanical distraction in extension and flexion. The system 310, 510 can apply a known distraction force. In some embodiments, the known distraction force is between 80 N and 100 N. In some embodiments, the distraction force is between 150 N and 200 N. In some embodiments, the known distraction force is greater than 50 N, greater than 60 N, greater than 70 N, greater than 80 N, greater than 90 N, greater than 100 N, greater than 110 N, greater than 120 N, greater than 130 N, greater than 140 N, greater than 150 N, greater than 160 N, greater than 170 N, greater than 180 N, greater than 190 N, greater than 200 N, greater than 210 N, greater than 220 N, greater than 230 N, greater than 240 N, greater than 250 N, etc.

[0239] The display 26 can provide a method of determining distraction distance other than by visually viewing a scale. The display 26 can provide a digital output of the distraction distance. The display 26 can provide a faster method of determining distraction distance than by visually viewing a scale. The display 26 can provide a more accurate method of determining distraction distance than by visually viewing a scale. The display 26 can be easier to use than a scale visible to the user. The data output of the display 26 can be real-time. The display 26 can be positioned within the surgical field. The display 26 can be positioned so that it is visible to the user during the procedure.

[0240] The display 26 may provide a visual reference for important anatomical features. The display 26 may provide a visual reference for Whiteside's line. The display 26 may provide a visual reference for the epicondylar axis. The display 26 may provide a visual reference for the mechanical axis.

[0241] The systems 310, 510 can provide balanced right-angle flexion clearance. The systems 310, 510 can provide an improved ability to measure balanced flexion clearance. The systems 310, 510 can provide an improved ability to achieve balanced flexion clearance. The systems 310, 510 can provide a guide for rotationally aligning the femoral components. The systems 310, 510 can provide improved recording of measurements during a procedure. The systems 310, 510 can provide improved storage of measurements during a procedure.

[0242] In some methods of use, the procedure may include one or more of the following steps: A user may complete a distal femoral resection. The distal femoral resection may be orthogonal to the mechanical axis of the femur in the coronal plane. A user may use a femoral preparation system 10 described herein. A user may complete a tibial resection. The tibial resection may be orthogonal to the mechanical axis of the femur in the coronal plane. A user may use a tibial preparation system 210 described herein. A user may insert a system 310, 510 between the tibia and the femur. A user may distract the knee in full extension.

[0243] The system 310, 510 may include a surgical orientation device 14 and a reference sensor device 16 described herein. In some embodiments, the system 310, 510 may use gyroscopic propagation to measure the coronal plane angle between the tibial resection and the femoral resection. A user may mount the surgical orientation device 14 on the femoral rigid body. For example, a user may mount the surgical orientation device 14 on the second coupler 374, 574. The reference sensor device 16 is at a fixed angle relative to the surgical orientation device 14. For example, a user may mount the reference sensor device 16 on the third coupler 378. The surgical orientation device 14 and the reference sensor device 16 may be zeroed. Gyroscopes within the surgical orientation device 14 and the reference sensor device 16 may be zeroed. The reference sensor device 16 may be moved to the tibial rigid body. For example, a user may mount the reference sensor device 16 on the first coupler 324, 524. The user can read the tibial / femoral angle on the display 26 of the surgical orientation device 14 .

[0244] The user can release the ligaments as needed to achieve the target angle. In some methods, the target angle is zero. The user can record the distraction distance (gap in extension). The user can remove the system 310, 510 from the leg in extension.

[0245] The user can flex the knee to 90°. The user can insert the system 310, 510 between the tibia and femur. The user can apply distraction in flexion. The user can read the flexion gap on the display 26 of the surgical orientation device 14. The user can visually read the flexion gap from the markings 340, 540. The user can calculate the anterior-posterior shift required to match the flexion gap with the extension gap.

[0246] In some methods of use, the user can attach the drill guide 380 and drill holes with the appropriate AP shift in the previous step. In some methods of use, the user can measure the posterior condyle angle on the surgical orienting device 14 from accelerometer readings. The user can set the implant sizing / drill guide to this angle. In some methods of use, the user either attaches the drill guide 380 and drills holes with the appropriate AP shift in the previous step, or measures the posterior condyle angle on the surgical orienting device 14 from accelerometer readings and sets the implant sizing / drill guide to this angle. In some embodiments, the universal cutting block 394 positions the posterior resection slot parallel to the tibial resection through precise alignment of the drilled guide holes, so no soft tissue release is required in flexion. The method may include attaching the implant sizing / drill guide to the distal resection surface. The method may include drilling holes, if not previously completed. The user simply reads the implant size and selects the appropriate universal cutting block. The user can remove the sizing / drill guide. The user can position and attach the cutting block using the drilled holes. The user can complete the resection.

[0247] In some methods of use, the user can attach the resection guide 580 and cut the femur with the appropriate AP shift in the previous step. In some methods of use, the user can measure the posterior condyle angle on the surgical orientation device 14 before making the posterior cut. In some embodiments, the posterior condyle angle is measured only in flexion. The user can set the implant sizing / drill guide to this angle. In some methods, the user makes the posterior cut. In some methods, the user makes one or more additional cuts based on the posterior cut. In some methods, the user makes one or more additional cuts based on specifications from the implant manufacturer. In some methods, the user makes one or more additional cuts based on a cutting guide provided by the manufacturer. In some embodiments, the soft tissue is released in extension to balance the gap in extension. In some embodiments, the soft tissue is not released in flexion.

[0248] Although the systems and methods presented herein have been described in the context of knee replacement procedures, these systems and / or their components, as well as these methods, may be used in other types of medical procedures as well, such as, but not limited to, shoulder replacement and hip replacement procedures.

[0249] Additionally, while the systems and methods presented herein have been described in the context of individual components and assemblies, in some embodiments, one or more of these assemblies may be provided in the form of a kit for use by a surgeon. For example, in some embodiments, a kit may include each of the components of the femoral preparation system 10 and the tibial preparation system 210 described above. In some embodiments, a kit may include only the surgical orientation device 14 and the reference sensor device 16. In some embodiments, a kit may include only the femoral preparation system 10 or only the tibial preparation system 210. In some embodiments, a kit may include only the systems 310, 510. Various other combinations and kits are possible.

[0250] While these inventions have been disclosed in the context of specific embodiments and examples, those skilled in the art will recognize that the invention extends beyond these specifically disclosed embodiments to other alternative embodiments and / or uses of the invention, as well as obvious modifications and equivalents thereof. Moreover, while several variations of the invention have been illustrated and described in detail, other modifications within the scope of the invention will be readily apparent to those skilled in the art based on this disclosure. It is also contemplated that specific features and aspects of the embodiments can be combined or subcombined in various ways, and that such combinations or subcombinations are within the scope of the invention. It is also understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another to form varying modes of the disclosed invention. Accordingly, it is intended that at least some of the scope of the inventions disclosed herein not be limited by the specific embodiments disclosed above. [Explanation of symbols]

[0251] 10 Femur Preparation System 12 Femur Jig Assembly 14 Surgical Orientation Device 16 Reference sensor device, reference device 18 First Coupling Device 20 Second coupling device 26 Display 28 User Input Devices 92 Cutting Block 210 Tibia Preparation System 212 Tibia Jig Assembly 214 Landmark Acquisition Assembly 220 Slender Members 226 Midline Reference Probe Assembly 227 Marking 228 Reference Sensor Device Interface 230 Orientation Device Interface 232 Cutting Block 310 Ablation Plane Orientation System 312 Tibia System 314 Tibia Base Plate 320 Extension member 322 Mounting Block 324 First Coupler 326 Additional Couplers 330 Guide part 332 posts 336 Regulating Devices 338 Interface 340 Marking 344 Camera 348 Clasp 350 Ratchet 352 Femoral System 354 Femoral Base Plate 360 Extension member 366 Post Mount 368 Rotation Interface 370 Mounting mechanism 374 Second Coupler 376 Bracket 378 Third Coupler 380 Drill Guide 382 Aperture 510 System 512 Tibia System 514 Tibia Base Plate 520 Extension member 522 Mounting Block 524 First Coupler 530 Guide part 532 posts 536 Regulating Device 540 Marking 548 Clasp 550 Ratchet 552 Femoral System 554 Femoral Base Plate 560 Extension member 566 Post Mount 570 Mounting mechanism 574 Second Coupler 576 Bracket 580 Resection Guide 582 Notch 588 Marking 600 Movable Interface 610 Movable Interface Lock 612 Turnbuckle 614 Shoulder screw 624 Marking 650 Torque Driver

Claims

[Claim 1] 1. An orthopedic system for orienting a cutting plane during a joint replacement procedure, comprising: a tibial component; a femoral component; a surgical orientation device coupled to or configured to couple to at least one of the tibial component and the femoral component, the surgical orientation device comprising: The housing and an inertial sensor configured to monitor the orientation of the surgical orientation device in a three-dimensional reference coordinate system during joint distraction; a user interface comprising a display screen configured to display measurements related to distraction of the joint.

Images