Device, system and method for determining position of hip prosthesis in bone of patient

Abstract

Devices, systems, and methods for determining a position of a hip prosthesis in a bone of a patient are disclosed. A method for planning an orthopaedic surgery may include determining a first set of target orientations of an acetabular cup of a hip prosthesis when a femoral prosthesis of the hip prosthesis is in a first tilt orientation; determining a second set of target orientations of the acetabular cup when the femoral prosthesis is in a second tilt orientation different from the first tilt; displaying a first graphical user interface (GUI) including a first graph representing a first set of target orientations of the acetabular cup; receiving user input; and in response to the input, displaying a second GUI, the second GUI including a second graph representing a second set of target orientations of the acetabular cup.

Description

[0001] Cross-references to related applications This application claims the benefit of U.S. Patent Application No. 18 / 823,359, filed September 3, 2024; U.S. Provisional Patent Application No. 63 / 541,603, filed September 29, 2023; and U.S. Provisional Patent Application No. 63 / 571,818, filed March 29, 2024. The entire contents of each of the foregoing applications are incorporated herein by reference. Technical Field

[0002] This disclosure relates generally to computer-aided surgical systems for planning and / or performing orthopedic surgeries, and more specifically to techniques for determining the position of a hip prosthesis in the bone of a patient. Background Technology

[0003] Arthroplasty is a well-known surgical procedure that replaces a diseased and / or damaged natural joint with a prosthetic joint. For example, in hip arthroplasty, a patient's natural ball-and-socket joint is partially or completely replaced by a prosthetic hip joint. A typical prosthetic hip joint includes an acetabular cup and a femoral prosthesis. The acetabular cup is implanted into the patient's acetabulum and typically includes a shell configured to engage the acetabulum and an inner bearing or cup liner coupled to that shell. The femoral prosthesis is implanted into the patient's femur and typically includes a femoral head and a stem embedded in the femoral medullary canal. The femoral head is configured to engage the cup liner of the acetabular cup to form a ball-and-socket joint that approximates the natural hip joint.

[0004] Typically, orthopedic surgeons can perform a certain amount of preoperative planning to, for example, determine the location of the hip prosthesis. This preoperative planning can be performed manually by the orthopedic surgeon based on examination of the patient and / or preoperative medical images of the patient's bone anatomy. However, this type of preoperative planning often fails to provide the orthopedic surgeon with an understanding of the patient's hip joint mechanics and, consequently, the performance of the hip prosthesis, possibly due to the planned location of the hip prosthesis. Summary of the Invention

[0005] According to one aspect, a method for planning orthopedic surgery on a patient's hip to implant a hip prosthesis having a femoral prosthesis and an acetabular cup may include: using a computer system to determine a first set of target orientations of the acetabular cup when the femoral prosthesis is in a first version orientation; using the computer system to determine a second set of target orientations of the acetabular cup when the femoral prosthesis is in a second version orientation different from the first version orientation; and using the computer system to display a first graphical user interface (GUI) including: (i) a first graphic representing the first set of target orientations of the acetabular cup, (ii) first interface elements indicating that the first graphic corresponds to the femoral prosthesis in the first version orientation, and (ii) i) a second interface element indicating that a second set of target orientations of the acetabular cup corresponding to a femoral prosthesis with a second tilt orientation is available for viewing; receiving user input associated with the second interface element using a computer system; and displaying a second GUI using a computer system and in response to receiving user input associated with the second interface element, the second GUI including: (i) a second graphic representing a second set of target orientations of the acetabular cup, (ii) a third interface element indicating that the second graphic corresponds to a femoral prosthesis with a second tilt orientation, and (iii) a fourth interface element indicating that a first set of target orientations of the acetabular cup corresponding to a femoral prosthesis with a first tilt orientation is available for viewing.

[0006] In some implementations, the computer system determines a second set of target orientations for the acetabular cup before receiving user input associated with a second interface element of the first GUI.

[0007] In some implementations, displaying the second GUI includes updating the first GUI by: (i) replacing the first graphic with a second graphic, (ii) replacing the first interface element with a fourth interface element, and (iii) replacing the second interface element with a third interface element.

[0008] In some embodiments, determining a first set of target orientations for the acetabular cup when the femoral prosthesis is in a first tilt orientation includes determining a target orientation for the acetabular cup when the femoral prosthesis is in the same tilt orientation as the patient's natural femur. In other embodiments, the first tilt is 15 degrees, and the second tilt is selected from the group consisting of -5 degrees, 5 degrees, 25 degrees, and 35 degrees.

[0009] In some implementations, the method may further include: receiving user input associated with a fourth interface element using a computer system; and displaying a first GUI using the computer system in response to receiving user input associated with the fourth interface element.

[0010] In some embodiments, the method may further include: using a computer system to determine a third set of target orientations of the acetabular cup when the femoral prosthesis is in a third tilt orientation different from the first tilt and the second tilt; using the computer system to receive user input associated with a fifth interface element included in both the first GUI and the second GUI, the fifth interface element indicating that the third set of target orientations of the acetabular cup corresponding to the femoral prosthesis in the third tilt orientation is available for viewing; and using the computer system and in response to receiving user input associated with the fifth interface element to display a third GUI, the third GUI including: (i) a third graphic representing the third set of target orientations of the acetabular cup, (ii) a sixth interface element indicating that the third graphic corresponds to the femoral prosthesis in the third tilt orientation, (iii) a fourth interface element indicating that the first set of target orientations of the acetabular cup corresponding to the femoral prosthesis in the first tilt orientation is available for viewing, and (iv) a second interface element indicating that the second set of target orientations of the acetabular cup corresponding to the femoral prosthesis in the second tilt orientation is available for viewing.

[0011] In some implementations, the method may further include using a computer system to determine that the number of target orientations for the acetabular cup is below an output threshold when the femoral prosthesis is in a third tilt orientation, which differs from the first and second tilts. In such implementations, the first GUI may further include a fifth interface element indicating that the computer system cannot generate a sufficient set of target orientations for the acetabular cup when the femoral prosthesis is in a third tilt orientation, and the second GUI may further include a fifth interface element.

[0012] In some embodiments, the first drawing includes a tilt axis, a slew axis, and a first closed shape, which, when drawn relative to the tilt axis and slew axis, surrounds a first set of target orientations around the acetabular cup. In some embodiments, the second drawing includes a tilt axis, a slew axis, and a second closed shape, which, when drawn relative to the tilt axis and slew axis, surrounds a second set of target orientations around the acetabular cup.

[0013] In some embodiments, the first graphic also includes a marker indicating the centroid of the first closed shape. In some embodiments, the second graphic also includes a marker indicating the centroid of the second closed shape.

[0014] In some embodiments, the first drawing further includes a first line that represents a first target boundary when drawn relative to the tilt axis and the rotation axis. In some embodiments, the second drawing also includes the first line. In some embodiments, the first line intersects at least one of: (i) a first closed shape in the first drawing, and (ii) a second closed shape in the second drawing. In some embodiments, the portions of the first and second closed shapes located inside the first target boundary are visually distinct from the portions of the first and second closed shapes located outside the first target boundary. In some embodiments, the first line is positioned in each of the first and second drawings based on patient-specific pelvic tilt measurements. In some embodiments, the first line is curved to reflect the non-linear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation. In other embodiments, the first line is straight but approximates the relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation. In some embodiments, the first target boundary is based on the minimum or maximum permissible tilt of the acetabular cup in a specific functional position of the patient. In some implementations, the minimum or maximum permissible tilt of the acetabular cup in a specific functional position in the patient is user-defined. In other implementations, the minimum or maximum permissible tilt of the acetabular cup in a specific functional position in the patient is predefined using values ​​taken from medical literature.

[0015] In some embodiments, the first drawing further includes a second line that represents a second target boundary when drawn relative to the tilt axis and the rotation axis. In some embodiments, the second drawing also includes a second line. In some embodiments, the second line intersects at least one of: (i) a first closed shape in the first drawing, and (ii) a second closed shape in the second drawing. In some embodiments, the portions of the first and second closed shapes located inside both the first and second target boundaries are visually distinct from the portions of the first and second closed shapes located outside either the first or second target boundary. In some embodiments, the second line is positioned in each of the first and second drawings based on patient-specific pelvic tilt measurements. In some embodiments, the first target boundary is based on the minimum permissible tilt of the acetabular cup in a patient's first functional position, and the second target boundary is based on the maximum permissible tilt of the acetabular cup in a patient's second functional position, different from the first functional position. In some embodiments, the minimum permissible tilt of the acetabular cup is 10 degrees when the first functional position is a flexed seated position, and the maximum permissible tilt of the acetabular cup is 30 degrees when the second functional position is a standing position.

[0016] In some embodiments, determining a first set of target orientations for the acetabular cup includes predicting a set of orientations for the acetabular cup that, when the femoral prosthesis is in a first tilt orientation, will not result in rim loading of the femoral prosthesis onto the acetabular cup or impingement between the femoral prosthesis and the acetabular cup. In some embodiments, determining a second set of target orientations for the acetabular cup includes predicting a set of orientations for the acetabular cup that, when the femoral prosthesis is in a second tilt orientation, will not result in rim loading of the femoral prosthesis onto the acetabular cup or impingement between the femoral prosthesis and the acetabular cup.

[0017] In some implementations, predicting a set of orientations for the acetabular cup that will not result in rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup when the femoral prosthesis is in a first or second tilt orientation includes: operating a first mathematical model, wherein a set of candidate orientations of the acetabular cup, patient-specific pelvic tilt measurements, and hip prosthesis type and size data are taken as inputs to the first mathematical model to generate predicted distances between (i) the edge of the acetabular cup liner and (ii) the contact position between the cup liner and the femoral head of the femoral prosthesis in each of several different functional positions of the patient; selecting candidate orientations of the acetabular cup such that each predicted distance is greater than a distance threshold. The second mathematical model is operated on, wherein the selected candidate orientation of the acetabular cup, patient-specific pelvic tilt measurements, hip prosthesis type and size data, and corresponding femoral prosthesis tilt are taken as inputs to generate a predicted femoral prosthesis rotation for each selected candidate orientation of the acetabular cup, until the femoral prosthesis and acetabular cup impinge in each of the patient’s multiple different functional positions; and the selected candidate orientation of the acetabular cup that causes each predicted femoral prosthesis rotation to be greater than a rotation threshold is identified as a set of orientations of the acetabular cup that are predicted to not cause rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup when the femoral prosthesis is in the corresponding tilt orientation.

[0018] In some implementations, determining the first set of target orientations for the acetabular cup further includes removing orientations of the acetabular cup that do not meet one or more target boundaries from a set of orientations of the acetabular cup that are predicted not to cause rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup when the femoral prosthesis is in a first tilt orientation, such that orientations of the acetabular cup that do not meet one or more target boundaries are not included in the first set of target orientations for the acetabular cup.

[0019] In some implementations, determining a second set of target orientations for the acetabular cup further includes removing orientations of the acetabular cup that do not meet one or more target boundaries from a set of orientations of the acetabular cup that are predicted not to cause rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup when the femoral prosthesis is in a second tilt orientation, such that orientations of the acetabular cup that do not meet one or more target boundaries are not included in the second set of target orientations for the acetabular cup.

[0020] In some embodiments, each of the one or more target boundaries is based on a corresponding minimum or maximum permissible tilt of the acetabular cup in a corresponding functional position in the patient, which has been converted into a reference frame of a first set of target orientations and a second set of target orientations for the acetabular cup using patient-specific pelvic tilt measurements. In some embodiments, the one or more target boundaries include a first target boundary based on the minimum permissible tilt of the acetabular cup in a first functional position in the patient. In some embodiments, the one or more target boundaries include a second target boundary based on the maximum permissible tilt of the acetabular cup in a second functional position in the patient, different from the first functional position. In some embodiments, the first target boundary requires the acetabular cup to have at least 10 degrees of tilt when the patient is in a flexed seated position. In some embodiments, the second target boundary requires the acetabular cup to have no more than 30 degrees of tilt when the patient is in a standing position. In some embodiments, the one or more target boundaries each reflect a non-linear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation.

[0021] According to another aspect, a method for planning orthopedic surgery on a patient's hip to implant a hip prosthesis with a femoral prosthesis and an acetabular cup may include: using a computer system to predict a set of target orientations for the acetabular cup that will not result in rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup; using a computer system to determine target boundaries by converting the minimum or maximum permissible tilt of the acetabular cup in the patient's functional position into a reference frame of a set of target orientations for the acetabular cup using patient-specific pelvic tilt measurements; and using a computer system to display graphics including a tilt axis, a yaw axis, a closed shape around the set of target orientations for the acetabular cup when drawn relative to the tilt axis and the yaw axis, and lines representing the target boundaries when drawn relative to the tilt axis and the yaw axis.

[0022] In some implementations, the line intersects a closed shape in the graphic, and the portion of the closed shape inside the target boundary is visually distinct from the portion outside the target boundary. In some implementations, the line is curved to reflect the non-linear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation.

[0023] According to another aspect, a method for planning orthopedic surgery on a patient's hip to implant a hip prosthesis having a femoral prosthesis and an acetabular cup may include: using a computer system to predict a set of target orientations for the acetabular cup that will not result in rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup; using a computer system to determine a first target boundary by converting the minimum permissible tilt of the acetabular cup in a first functional position of the patient into a reference frame of the set of target orientations for the acetabular cup using patient-specific pelvic tilt measurements; using a computer system to determine a second target boundary by converting the maximum permissible tilt of the acetabular cup in a second functional position of the patient into a reference frame of the set of target orientations for the acetabular cup using patient-specific pelvic tilt measurements; and using a computer system to display a graphic including a tilt axis, a rotation axis, a closed shape around the set of target orientations for the acetabular cup when drawn relative to the tilt axis and the rotation axis, a first line representing the first target boundary when drawn relative to the tilt axis and the rotation axis, and a second line representing the first target boundary when drawn relative to the tilt axis and the rotation axis.

[0024] In some embodiments, at least one of the first and second lines intersects a closed shape in the graphic, and the portion of the closed shape located inside both the first and second target boundaries is visually distinct from each portion of the closed shape located outside either the first or second target boundary. In some embodiments, the first and second lines are each curved to reflect a non-linear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation. In some embodiments, the first target boundary reflects a minimum permissible rotation of 10 degrees of the acetabular cup when the first functional position is a flexed seated position. In some embodiments, the second target boundary reflects a maximum permissible rotation of 30 degrees of the acetabular cup when the second functional position is a standing position. In some embodiments, the graphic also includes a marker indicating the centroid of the closed shape.

[0025] In some implementations, predicting a set of target orientations for the acetabular cup that will not result in rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup includes: operating a first mathematical model, wherein a set of candidate orientations of the acetabular cup, patient-specific pelvic tilt measurements, and hip prosthesis type and size data are taken as inputs to the first mathematical model to generate a predicted distance between (i) the edge of the acetabular cup liner and (ii) the contact position between the cup liner and the femoral head of the femoral prosthesis in each of several different functional positions of the patient; selecting the acetabular cup to make the predicted distance Candidate orientations with a predicted distance greater than a distance threshold are selected; a second mathematical model is operated, wherein the selected candidate orientations of the acetabular cup, patient-specific pelvic tilt measurements, and hip prosthesis type and size data are taken as inputs to the second mathematical model to generate predicted femoral prosthesis rotation for each selected candidate orientation of the acetabular cup, until the femoral prosthesis and acetabular cup impinge in each of the patient’s multiple different functional positions; and the selected candidate orientations of the acetabular cup that cause each predicted femoral prosthesis rotation to be greater than a rotation threshold are identified as a set of target orientations of the acetabular cup.

[0026] According to another aspect, a method for planning orthopedic surgery on a patient's hip to implant a hip prosthesis having a femoral prosthesis and an acetabular cup may include: using a computer system to predict a first set of orientations for the acetabular cup that will not result in rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup; using a computer system to determine a second set of target orientations for the acetabular cup by removing orientations from the first set of orientations that do not meet one or more target boundaries; and using a computer system to display a graph including a tilt axis, a slew axis, and a closed shape that surrounds the second set of orientations for the acetabular cup when drawn relative to the tilt axis and the slew axis.

[0027] In some implementations, the first set of orientations for predicting the acetabular cup that will not result in rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup includes: operating a first mathematical model, wherein a set of candidate orientations of the acetabular cup, patient-specific pelvic tilt measurements, and hip prosthesis type and size data are taken as inputs to the first mathematical model to generate a predicted distance between (i) the edge of the acetabular cup liner and (ii) the contact position between the cup liner and the femoral head of the femoral prosthesis in each of the patient's multiple different functional positions; selecting the acetabular cup to make the predicted distance... Candidate orientations with a predicted distance greater than a distance threshold are selected; a second mathematical model is operated, wherein the selected candidate orientations of the acetabular cup, patient-specific pelvic tilt measurements, and hip prosthesis type and size data are used as inputs to generate predicted femoral prosthesis rotation for each selected candidate orientation of the acetabular cup, until the femoral prosthesis and acetabular cup impinge in each of the patient's multiple different functional positions; and the selected candidate orientations of the acetabular cup that cause each predicted femoral prosthesis rotation to exceed a rotation threshold are identified as the first set of orientations of the acetabular cup.

[0028] In some embodiments, the graph also includes a marker indicating the centroid of the closed shape. In some embodiments, each of the one or more target boundaries is based on a corresponding minimum or maximum permissible tilt of the acetabular cup in a corresponding functional position in the patient, which has been converted to a first set of orientations and a second set of orientations of the acetabular cup using patient-specific pelvic tilt measurements. In some embodiments, the one or more target boundaries include a first target boundary based on the minimum permissible tilt of the acetabular cup in a first functional position in the patient. In some embodiments, the one or more target boundaries include a second target boundary based on the maximum permissible tilt of the acetabular cup in a second functional position in the patient, different from the first functional position. In some embodiments, the first target boundary requires the acetabular cup to have at least 10 degrees of tilt when the patient is in a flexed seated position. In some embodiments, the second target boundary requires the acetabular cup to have no more than 30 degrees of tilt when the patient is in a standing position. In some embodiments, the one or more target boundaries each reflect a non-linear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation.

[0029] In some implementations, when the second set of target orientations of the acetabular cup is an empty set, the drawing also includes at least one of the following: (i) a closed shape that surrounds the first set of orientations of the acetabular cup when drawn relative to the tilt axis and the yaw axis, and (ii) one or more lines that represent one or more target boundaries when drawn relative to the tilt axis and the yaw axis, as defined by user-defined preferences.

[0030] According to another aspect, a method for planning orthopedic surgery on a patient's hip to implant a hip prosthesis having a femoral prosthesis and an acetabular cup may include: operating a first mathematical model using a computer system, wherein a set of candidate orientations of the acetabular cup, patient-specific pelvic tilt measurements, and hip prosthesis type and size data are taken as inputs to the first mathematical model to generate a predicted distance between (i) the edge of the cup liner of the acetabular cup and (ii) the contact position between the cup liner and the femoral head of the femoral prosthesis in each of a plurality of different functional positions of the patient; The computer system selects candidate orientations of the acetabular cup that make each predicted distance greater than a distance threshold; the computer system operates a second mathematical model, with the selected candidate orientations of the acetabular cup, patient-specific pelvic tilt measurements, hip prosthesis type and size data, and planned tilt of the femoral prosthesis as inputs to generate predicted femoral prosthesis rotation for each selected candidate orientation of the acetabular cup, until the femoral prosthesis and acetabular cup impinge in each of several different functional positions of the patient; the computer system identifies the selected candidate orientations of the acetabular cup that make each predicted femoral prosthesis rotation greater than a rotation threshold as a set of target orientations of the acetabular cup predicted to not result in rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup when the femoral prosthesis is in the planned tilt orientation; and the computer system provides a user interface that presents the set of target orientations of the acetabular cup to an orthopedic surgeon.

[0031] In some implementations, the method may further include: measuring the preoperative tilt of the patient's natural femur from one or more medical images using a computer system; and using the measured preoperative tilt as the planned tilt of the femoral prosthesis when operating a second mathematical model.

[0032] In some implementations, identifying selected candidate orientations of the acetabular cup that cause each of the predicted femoral prosthesis rotations to be greater than a rotation threshold includes: determining a first number of selected candidate orientations of the acetabular cup that cause each of the predicted femoral prosthesis rotations to be greater than a first rotation threshold; and, in response to a size threshold less than a set of target orientations of the acetabular cup, determining a second number of selected candidate orientations of the acetabular cup that cause each of the predicted femoral prosthesis rotations to be greater than a second rotation threshold, the second rotation threshold being less than the first rotation threshold.

[0033] In some embodiments, the user interface includes a graph comprising a tilt axis, a slew axis, and a closed shape, the closed shape being drawn relative to the tilt axis and slew axis around a set of target orientations of the acetabular cup. In some embodiments, the graph also includes markers indicating the centroid of the closed shape. In some embodiments, the method further includes receiving input via the user interface indicating a planned orientation of the acetabular cup selected by an orthopedic surgeon, and the graph also includes markers representing the planned orientation of the acetabular cup when drawn relative to the tilt axis and slew axis.

[0034] In some embodiments, the method may further include: using a computer system to detect the actual orientation of the acetabular cup relative to the patient's acetabulum during orthopedic surgery; and presenting a comparison of the actual orientation of the acetabular cup with a set of target orientations of the acetabular cup via a user interface during orthopedic surgery. In some embodiments, the user interface includes graphics including a tilt axis, a rotation axis, a closed shape around a set of target orientations of the acetabular cup when drawn relative to the tilt axis and the rotation axis, and markers representing the actual orientation of the acetabular cup when drawn relative to the tilt axis and the rotation axis.

[0035] According to another aspect, a method for planning orthopedic surgery involving a patient's pelvis may include: acquiring a standing medical image by a computer system, the standing medical image showing the sagittal profile of the patient's pelvis in a standing position; acquiring a seated medical image by a computer system, the seated medical image showing the sagittal profile of the patient's pelvis in a seated position; determining a standing sacral slope value from the standing medical image using the computer system; determining a seated sacral slope value from the seated medical image using the computer system; calculating a pelvic mobility value as the difference between the standing sacral slope value and the seated sacral slope value using the computer system; and generating a user alert using the computer system in response to the calculated pelvic mobility value being outside a predetermined range.

[0036] In some embodiments, generating a user alert includes displaying a message on a computer system indicating that the patient has a stiff spine in response to a calculated pelvic mobility value being less than the lower end of a predetermined range. In some embodiments, generating a user alert includes displaying a message on a computer system indicating that the patient has an overactive spine in response to a calculated pelvic mobility value being greater than the upper end of a predetermined range. In some embodiments, each of the standing sacral inclination value, the seated sacral inclination value, and the pelvic mobility value is an angle expressed in degrees. In some embodiments, the lower end of the predetermined range is 10 degrees. In some embodiments, the upper end of the predetermined range is 35 degrees.

[0037] In some embodiments, determining a standing sacral slope value from a standing medical image includes: receiving one or more user inputs that position a standing reference line across the upper edge of the S1 endplate of the patient shown in the standing medical image; and calculating the standing sacral slope value as the arctangent of the slope of the user-positioned standing reference line. In some embodiments, determining a seated sacral slope value from a seated medical image includes: receiving one or more user inputs that position a seated reference line across the upper edge of the S1 endplate of the patient shown in the seated medical image; and calculating the seated sacral slope value as the arctangent of the slope of the user-positioned seated reference line.

[0038] According to another aspect, a method for planning orthopedic surgery involving a patient's pelvis may include: acquiring a standing medical image by a computer system, the standing medical image showing the sagittal profile of the patient's pelvis in a standing position; determining, using the computer system, a sacral slope value, a midpoint of the sacral slope, and a femoral head center from the standing medical image; calculating a spinopelvic tilt value using the midpoint of the sacral slope and the femoral head center; calculating a pelvic angle of incidence value as the sum of the sacral slope value and the spinopelvic tilt value using the computer system; and generating a user alert using the computer system in response to the calculated pelvic angle of incidence value being outside a predetermined range.

[0039] In some implementations, generating a user alert includes displaying a message on a computer system advising the surgeon to assess the patient's risk of bone-on-bone impingement during surgery. In some implementations, the message is displayed on the computer system during orthopedic surgery. In some implementations, each of the sacral inclination value, spinopelvic tilt value, and pelvic incidence angle value is an angle expressed in degrees. In some implementations, the predetermined range is 45 degrees to 65 degrees.

[0040] In some implementations, determining the sacral slope value and the midpoint of the sacral slope from a standing medical image includes: receiving one or more user inputs that position a reference line across the upper edge of the S1 endplate of the patient shown in the standing medical image; calculating the sacral slope value as the arctangent of the slope of the user-positioned reference line; and calculating the midpoint of the sacral slope as the midpoint of the user-positioned reference line.

[0041] In some implementations, using the midpoint of the sacral slope and the center of the femoral head to calculate the spinopelvic tilt value includes calculating the arctangent of the slope of the derived line defined by the midpoint of the sacral slope and the center of the femoral head.

[0042] In some embodiments, determining the femoral head center from a standing medical image includes: receiving one or more user inputs that locate a reference circle around the femoral head of the patient shown in the standing medical image; and recording the center of the reference circle located by the user as the femoral head center. In other embodiments, determining the femoral head center from a standing medical image includes: receiving one or more user inputs that locate: (i) a first reference circle around the first femoral head of the patient shown in the standing medical image, and (ii) a second reference circle around the second femoral head of the patient shown in the standing medical image; determining the midpoint of the femoral head between: (i) the center of the first reference circle located by the user and (ii) the center of the second reference circle located by the user; and recording the midpoint of the femoral head as the femoral head center. Attached Figure Description

[0043] The specific implementation method refers to the following figures, in which: Figure 1 This is an exploded perspective view of an implementation scheme for a hip prosthesis, including the femoral prosthesis and the acetabular cup; Figure 2 yes Figure 1 Another perspective view of the hip prosthesis, which has an acetabular cup that is implanted into the patient's acetabulum; Figure 3 yes Figure 2 Another perspective view of the hip prosthesis, showing the femoral prosthesis engaging with the acetabular cup; Figure 4 It is used to determine hip prostheses (such as Figure 1 A block diagram of a computer system implementation scheme for the placement of a hip prosthesis in the patient's bone; Figure 5 It is used to determine hip prostheses (such as Figure 1 A block diagram of another implementation of a computer system for the location of a hip prosthesis in the patient's bone; Figures 6A to 6CThis is a flowchart of a method for determining patient-specific pelvic tilt measurements, which can be performed by... Figure 4 Computer systems or Figure 5 The computer system executes; Figure 7 It is possible Figures 6A to 6C The exemplary screen images displayed during the execution of the method show a seated medical image of the patient's hip joint and a seated reference line positioned by the user. Figure 8 It is possible Figures 6A to 6C The exemplary screen images displayed during the execution of the method show a standing medical image of the patient's hip joint and a standing reference line positioned by the user; Figure 9 It is possible Figures 6A to 6C The exemplary screen image displayed during the execution of the method shows a standing medical image of the patient's hip joint and a reference circle positioned by the user; Figures 10A to 10B This is a flowchart of a method for determining and presenting multiple sets of target orientations for the acetabular cup corresponding to femoral prostheses with different tilt orientations. This method can be developed by... Figure 4 Computer systems or Figure 5 The computer system executes; Figure 11 It is possible Figures 10A to 10B The exemplary screen images displayed during the execution of the method include graphics showing the patient target area corresponding to a 15-degree femoral implant tilt and the optimal orientation of the acetabular cup within the patient target area. Figure 12 It is possible Figures 10A to 10B The exemplary screen image displayed during the execution of the method includes a graphic showing the patient target area and the user-modified orientation of the acetabular cup within the patient target area corresponding to a 15-degree femoral implant tilt. Figure 13 It is possible Figures 10A to 10B The exemplary screen images displayed during the execution of the method, and the exemplary screen images include graphics showing different patient target areas and the optimal orientation of the acetabular cup in the different patient target areas corresponding to a 25-degree femoral implant tilt; Figure 14 It is possible Figures 10A to 10B The exemplary screen image displayed during the execution of the method, and the exemplary screen image includes a graph that does not show the patient target area corresponding to a 35-degree femoral implant tilt and the associated user alerts; Figure 15A It shows Figure 11An alternative graphic of the screen image, which shows the patient's target area and the boundaries of the two targets; Figure 15B It shows Figure 11 Another alternative graphic of the screen image shows the patient target area and two target boundaries, but the portion of the patient target area outside the target boundaries is visually different (in this embodiment, it is colored differently). Figure 15C It shows Figure 11 Another alternative graphic of the screen image shows two target boundaries and a modified patient target area, where portions outside the target boundaries are removed; Figure 15D It shows Figure 11 Another alternative graphic of the screen image shows only the modified patient target area, where the portion outside the target boundary has been removed; and Figure 16 It is used to implant hip prostheses (such as...) into a patient's hip. Figure 1 A flowchart illustrating the surgical procedure for hip prosthesis implantation, a method that can be performed by a plastic surgeon. Figure 4 Computer systems or Figure 5 The computer system executes this. Detailed Implementation

[0044] While the concepts of this disclosure are readily available in various modifications and alternatives, specific exemplary embodiments thereof have been shown by way of example in the accompanying drawings and will be described in detail herein. However, it should be understood that this disclosure is not intended to limit the concepts to the specific forms disclosed, but rather, the object of the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

[0045] Throughout this specification, when referring to orthopedic implants and surgical instruments described herein, as well as the natural anatomy of a patient, terms indicating anatomical reference, such as anterior, posterior, medial, lateral, superior, inferior, etc., may be used. These terms have well-known meanings in anatomical studies and orthopedic surgery. Unless otherwise stated, these anatomical reference terms used in the written details and claims are intended to be consistent with their well-known meanings.

[0046] References to "an embodiment," "an embodiment," "an exemplary embodiment," etc., in this specification mean that the described embodiment may include a particular feature, structure, or characteristic, but each embodiment may or may not include that particular feature, structure, or characteristic. Furthermore, these phrases do not necessarily refer to the same embodiment. Additionally, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, whether or not it is explicitly described, it should be assumed that implementing such a particular feature, structure, or characteristic in conjunction with other embodiments is within the knowledge of a person skilled in the art. Furthermore, it should be understood that items included in a list in the form of "at least one of A, B, and C" may mean (A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C). Similarly, items listed in the form of "at least one of A, B, or C" may mean (A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C).

[0047] In the accompanying drawings, certain structural or methodological features may be shown in a specific arrangement and / or order. However, it should be understood that such a specific arrangement and / or order may not be necessary. Instead, in some embodiments, such features may be arranged in a different manner and / or order than those shown in the illustrative drawings. Furthermore, the inclusion of structural or methodological features in a particular drawing does not imply that such features are necessary in all embodiments, and in some embodiments, these features may be omitted or may be combined with other features.

[0048] Now for reference Figure 1 An exemplary hip orthopedic prosthesis 100 includes a femoral prosthesis 102 and an acetabular cup 104. In use, as discussed in more detail below, the hip orthopedic prosthesis 100 is configured to replace a patient's natural hip joint. For this purpose, the femoral prosthesis 102 is configured to be implanted into the proximal end of a surgically prepared femur in the patient, and the acetabular cup 104 is configured to be implanted into a surgically prepared acetabulum in the patient's pelvis. Once implanted in this manner, the femoral prosthesis 102 is supported by the acetabular cup 104, and the femoral prosthesis 102 and the acetabular cup 104 cooperate to form a prosthetic hip joint for the patient.

[0049] An exemplary femoral prosthesis 102 includes a stem 110 having an elongated distal end 112 and a neck 114 located at a proximal end 116. The elongated distal end 112 is sized and shaped to be implanted into the medullary canal of a patient's femur to secure the femoral prosthesis 102 to the femur. The femoral prosthesis 102 also includes a femoral head 118 secured to the neck 114 of the stem 110. The femoral head 118 is substantially spherical and is configured to be received in an acetabular cup 104 to form an artificial ball-and-socket joint in the patient's hip. The stem 110 and the femoral head 118 may be formed separately from an implant-grade metallic material, such as cobalt-chromium. In some embodiments, the stem 110 may also include an outer coating, such as Porocoat. ® An outer coating that promotes bone inward growth to allow the patient's bone to bio-attach to the stem 110 after implantation.

[0050] The acetabular cup 104 includes an acetabular shell 120 and an acetabular cup liner 122 configured to be received within the acetabular shell 120. The acetabular shell 120 has a generally hemispherical shape and includes a convex outer wall 130 and a concave inner wall 132 opposite to the convex outer wall 130. The inner wall 132 defines a hemispherical recess 134, the shape and size of which are designed to receive the acetabular cup liner 122 to form an assembled acetabular cup 104. The acetabular shell 120 can be formed of any suitable implant-grade metallic material, such as, for example, titanium alloy. Similar to the stem 110 of the femoral prosthesis 102, the outer wall 130 of the acetabular shell 120 may include an outer coating, such as Porocoat. ® An outer coating promotes inward bone growth to allow the patient's bone to bio-attach to the acetabular shell 120 after implantation. As discussed above, the acetabular cup liner 122 is configured to be received in a hemispherical recess 134 of the acetabular shell 120 and is exemplarily formed of a polymeric material, such as, for example, polyethylene. Of course, in other embodiments, the acetabular cup liner 122 may be formed of other materials, such as ceramic materials, etc. While the exemplary acetabular cup 104 includes a single liner 122, it is contemplated that other embodiments may include multiple liners 122 (sometimes referred to as a "dual-mobility implant").

[0051] like Figure 2As shown, during the execution of an orthopedic surgery, the orthopedic surgeon implants an acetabular cup 104 into the patient's acetabulum 200 to replace the patient's natural "socket" in the corresponding hip joint. In doing so, the orthopedic surgeon can prepare the patient's acetabulum 200 (e.g., by enlarging the acetabulum) and, based on preoperative or intraoperative planning, implant the acetabular shell 120 of the acetabular cup 104 into the surgically prepared acetabulum 200, as discussed in more detail below. In doing so, the outer wall 130 of the acetabular shell 120 contacts or faces the prepared bone of the patient's acetabulum 200. The orthopedic surgeon can then insert an acetabular cup liner 122 into the hemispherical recess 134 of the acetabular shell 120 to form the implanted, assembled acetabular cup 104.

[0052] The orthopedic surgeon also prepares the proximal end of the patient's femur (not shown) for the implantation of the femoral prosthesis 102. Such surgical preparation may include removing a portion of the proximal end of the patient's femur (e.g., removing the natural femoral head of the patient's femur) and preparing the medullary canal of the patient's femur to receive the stem 110 of the femoral prosthesis 102.

[0053] After the femoral prosthesis 102 and acetabular cup 104 have been implanted into the corresponding bone anatomy of the patient, the orthopedic surgeon can insert the femoral head 118 of the femoral prosthesis 102 into the acetabular cup liner 122, as follows: Figure 3 As shown. In this way, the femoral prosthesis 102 and the acetabular cup 104 form a prosthetic hip joint for the patient. However, the function of the hip prosthesis 100 depends at least in part on the proper positioning of the acetabular cup 104 within the patient's acetabulum 200. That is, the orientation of the acetabular cup 104 relative to the patient's acetabulum 200 (i.e., the degree of anteversion and tilt) affects the performance of the hip prosthesis 100. For example, if the orientation of the acetabular cup 104 relative to the patient's acetabulum 200 is not correctly selected and subsequently achieved, the femoral prosthesis 102 may exhibit a certain amount of marginal load on the acetabular cup liner 122 of the acetabular cup 104. Such marginal load of the acetabular cup 104 may be associated with a higher risk of dislocation of the femoral prosthesis 102 from the acetabular cup 104 during the patient's normal activities. Furthermore, the risk of dislocation may increase if any part of the femoral prosthesis 102, other than the supporting surface of the femoral head 118 (such as the stem 116), impinges on or comes into contact with any part of the acetabular cup 102 (including the housing 120 and / or liner 122). Therefore, determining the appropriate orientation of the acetabular cup 104 (which has a reduced risk of such impingement and / or reduced or minimal edge load) can improve the performance of the hip prosthesis 100 and reduce the likelihood of dislocation of the femoral prosthesis 102 from the acetabular cup 104.

[0054] Now for reference Figure 4An exemplary computer system 400 for determining the position of a hip prosthesis (such as hip prosthesis 100) includes a hip prosthesis positioning analysis device 402 and an imaging device 404 communicatively coupled to the analysis device 402 via a network 406. In use, as discussed in more detail below, an orthopedic surgeon can manipulate the analysis device 402 to plan the orientation of the acetabular cup 104 relative to the patient's acetabulum 200. In addition to the features and functions described below, the computer system 400 may also include any features and functions described in the following documents: U.S. Patent Application Publications Nos. 2022 / 0202494 and 2022 / 0202503, published June 30, 2022, and PCT International Publication No. WO 2022 / 144448, published July 7, 2022, the entire disclosures of which are incorporated herein by reference.

[0055] The hip prosthesis positioning and analysis device 402 can be embodied as any type of computer or computing device capable of performing the functions described herein. For example, the analysis device 402 can be embodied as a desktop computer, surgical navigation computer, laptop computer, tablet computer, smartphone, mobile computer, smart device, wearable computer system, or other computer or computing device. Figure 4 As shown, the exemplary analysis device 402 includes an analysis engine 410, an input / output (“I / O”) subsystem 412, a data storage device 414, a display 416, a communication system 418, and in some embodiments includes one or more peripheral devices 420. Of course, in other embodiments, the analysis device 402 may include additional components or other components, such as those typically found in typical computing devices. Additionally, in some embodiments, one or more of the exemplary components may be incorporated into another component or otherwise formed as part of another component.

[0056] Analysis engine 410 may be embodied as any type of controller, function block, digital logic or other component, device, circuit, or collection thereof capable of performing the functions described herein. In an exemplary embodiment, analysis engine 410 includes processor 422 and memory 424. Processor 422 may be embodied as any type of processor capable of performing the functions described herein. For example, processor 422 may be embodied as a single-core or multi-core processor, digital signal processor, microcontroller, or other processor or processing / control circuitry. Similarly, memory 424 may be embodied as any type of volatile and / or non-volatile memory or data storage device capable of performing the functions described herein. In operation, memory 424 may store various data and software used during the operation of analysis device 402, such as operating systems, applications, executable software, programs, libraries, and drivers that can be executed by processor 422 or otherwise used.

[0057] The analysis engine 410 is communicatively coupled to other components of the analysis device 402 via an I / O subsystem 412, which may be embodied as circuitry and / or components to facilitate input / output operations between the analysis engine 410 (e.g., processor 422 and / or memory 424) and other components of the analysis device 402. For example, the I / O subsystem 412 may be embodied as or otherwise include a memory controller hub, an input / output control hub, firmware devices, communication links (i.e., point-to-point links, bus links, wires, cables, optical fibers, printed circuit board traces, etc.) and / or other components and subsystems facilitating input / output operations. In some embodiments, the I / O subsystem 412 may form part of a system-on-a-chip (SoC) and be integrated onto a single integrated circuit chip along with the analysis device 410 (e.g., processor 422 and memory 424) and other components of the analysis engine 410. Additionally, in some embodiments, memory 424 or a portion thereof may be integrated into processor 422.

[0058] Data storage device 414 can be embodied as any type of device configured for short-term and / or long-term data storage, such as, for example, a solid-state drive, hard disk drive, memory device and circuitry, memory card, non-volatile flash memory, or other data storage device. In an exemplary embodiment, data storage device 414 stores various types of data used by analysis device 402 to perform the functions described herein. For example, data storage device 414 can store one or more medical images 430 of a patient. Medical images 430 can be generated by imaging device 404 and transmitted via network 406 to analysis device 402 for local storage in data storage device 414. As discussed in more detail below, medical images can be embodied as X-ray images, computed tomography (CT) images, magnetic resonance imaging (MRI) images, or other medical images of the patient's bone anatomy in various functional locations.

[0059] The data storage device 414 may also store one or more landmark models 432, which may embody one or more models or algorithms (e.g., machine learning algorithms) capable of analyzing the medical image 404 and determining associated anatomical landmarks. As discussed in more detail below, the analysis device 402 may use the landmark model 432 to determine anatomical landmarks automatically, and / or determine anatomical landmarks manually based on annotations of the medical image received from the orthopedic surgeon.

[0060] Additionally, data storage device 414 may store contact model 434 and / or impact model 436. As discussed in more detail below, contact model 434 is illustratively represented as a mathematical model (specifically, a regression model) that takes as input a set of candidate orientations of acetabular cup 104, patient-specific pelvic tilt measurements, and type and size data of hip prosthesis 100. Using these inputs, contact model 434 generates predicted distances between (i) the edge of the cup liner 122 of acetabular cup 102 and (ii) the contact position between the cup liner 122 and the femoral head 118 of femoral prosthesis 102 for both standing and seated positions, these predicted distances being associated with each candidate orientation of acetabular cup 102 supplied to contact model 434 as input. The impact model 436 is illustratively represented as a mathematical model (specifically, a regression model) that takes as input a set of candidate orientations of the acetabular cup 104, patient-specific pelvic tilt measurements, type and size data of the hip prosthesis 100, and the tilt of the femoral prosthesis 102 to be oriented. Using these inputs, the impact model 436 generates predicted femoral prosthesis rotation for both the patient's standing and seated positions up to the impact of the femoral prosthesis 102 and the acetabular cup 104, and this predicted femoral prosthesis rotation is associated with each candidate orientation of the acetabular cup supplied as input to the impact model 436. As discussed further below, in an exemplary embodiment, the analysis device 402 uses contact model 434 and impact model 436 together to predict multiple orientations of the acetabular cup 104 that will not result in edge loading of the femoral prosthesis 102 on the acetabular cup 104 or impact between the femoral prosthesis 102 and the acetabular cup 104 when the femoral prosthesis 102 is in various tilt orientations.

[0061] Display 416 can be embodied as any type of display capable of displaying information to a user of analysis device 402 (e.g., a plastic surgeon). For example, display 416 can be embodied as a liquid crystal display (LCD), a light-emitting diode (LED) display, an organic light-emitting diode (OLED) display, a cathode ray tube (CRT) display, a plasma display, an augmented or virtual reality headset, and / or other display devices. In some embodiments, display 416 may include a touchscreen that can be configured to receive input from the plastic surgeon based on haptic interaction. Additionally, in some embodiments, display 416 or a repeating display 416 may be decoupled from analysis device 402 but communicatively coupled to it, such as... Figure 4 The center is indicated by a dashed line.

[0062] The communication subsystem 418 can be embodied as any type of communication circuit, device, or combination thereof capable of enabling communication between the analysis device 402 and the imaging device 404 and / or other devices of the computer system 400. For this purpose, the communication subsystem 418 can be configured to use any one or more communication technologies (e.g., wireless or wired communication) and associated protocols (e.g., Ethernet, Bluetooth). ® Wi-Fi ® This type of communication can be achieved using technologies such as WiMAX, LTE, and 5G.

[0063] One or more peripheral devices 420 may include any number of additional peripheral or interface devices, such as other input / output devices, storage devices, etc. The specific devices included in peripheral devices 420 may depend on, for example, the type and / or intended use of analysis device 402.

[0064] Imaging device 404 may be embodied as any type of device or collection of devices capable of generating medical images of a patient's bone anatomy preoperatively and / or intraoperatively. In some embodiments, imaging device 404 is embodied as (or includes) an X-ray imaging machine capable of generating two-dimensional medical images. In other embodiments, imaging device 404 may be embodied as (or includes) an imaging device, such as an MRI or CT scanner, capable of generating three-dimensional medical images. In exemplary embodiments, imaging device 404 generates images of the hip joint when the patient's hip joint is positioned in several functional positions, including one or more anteroposterior and / or sagittal (lateral) medical images when the patient is standing, sitting, and / or supine. Of course, in other embodiments, imaging device 404 may be configured to generate additional or different medical images of the patient's bone anatomy. For example, in some embodiments, the medical images may include the patient's entire femur, the patient's entire pelvis, and / or part or all of the patient's spine.

[0065] Network 406 can be embodied as any type of communication network capable of facilitating communication between the hip prosthesis positioning and analysis device 402 and the imaging device 404 (and other components of the computer system 400). Therefore, network 406 may include one or more networks, routers, switches, gateways, computers, and / or other intermediate devices. For example, network 406 can be embodied as or otherwise include one or more local area networks or wide area networks, cellular networks, publicly available global networks (e.g., the Internet), self-organizing networks, short-range communication networks or links, or any combination thereof.

[0066] In some embodiments, the computer system 400 may also include a surgical tracking system 408. The surgical tracking system 408 may be embodied in any type of surgical tracking system, surgical navigation system, digital surgical system, etc. For example, in some embodiments, the surgical tracking system 408 may be embodied in a computer-assisted orthopedic surgery (CAOS) system. As discussed in more detail below, the surgical tracking system 408 is configured to detect intraoperatively the actual orientation of the acetabular cup 104 (trial or final component) relative to the patient's bone anatomy (e.g., relative to the patient's acetabulum 200). For example, the computer system 400 may be configured to optically track markers attached to the patient's acetabulum 200 and acetabular cup 104 to facilitate this detection. In some embodiments, the tracking provided by the surgical tracking system 408 may replace intraoperative images generated by the imaging device 404, as discussed in more detail below.

[0067] Now for reference Figure 5 In some implementations, computer system 400 may be implemented as a cloud-based system. In such implementations, computer system 400 may include a location analytics server 502, which is communicatively coupled to local computer device 504 via network 406. Location analytics server 502 may be embodied as any type of computer or computing device capable of performing the functions described herein. For example, location analytics server 502 may be embodied as a server, rack-mount computer, network appliance, desktop computer, laptop computer, tablet computer, or other computer or computer device.

[0068] like Figure 5 As shown, each of the analysis engine 410 and the data storage device 412 resides on the positioning analysis server 502. Therefore, the positioning analysis server 502 is configured to perform substantially the same functions as described above and below with respect to the analysis device 402. For example, the positioning analysis server 502 is configured to acquire or otherwise receive medical images of a patient's hip joint from the imaging device 404 and determine patient-specific pelvic tilt measurements based on these medical images. Additionally, the positioning analysis server 502 is configured to determine or predict multiple sets of target orientations of the acetabular cup 104, including multiple sets of target orientations of the acetabular cup 104 that will not result in edge loading of the femoral prosthesis 102 on the acetabular cup 104 or impingement of the femoral prosthesis 102 and the acetabular cup 104 when the femoral prosthesis 102 is in various tilt orientations. The positioning analysis server 502 may send any data in this data and / or graphics representing any data in this data to the local computer device 504.

[0069] Local computer device 504 may be embodied as any type of computer or computing device capable of performing the functions described herein. For example, local computer device 504 may be embodied as a desktop computer, laptop computer, tablet computer, smartphone, mobile computer, smart device, wearable computer system, or other computer or computer device. Illustratively, local computer device 504 includes a processor 522, memory 520, input / output (“I / O”) subsystem 412, display 416, communication system 418, and in some embodiments includes one or more peripheral devices 420.

[0070] Processor 522 may be similar to processor 422 of the analysis device 402 described above, and may be embodied as any type of processor capable of performing the functions described herein. For example, processor 522 may be embodied as a single-core or multi-core processor, digital signal processor, microcontroller, or other processor or processing / control circuitry. Similarly, memory 524 may be similar to memory 424 of the analysis device 402 described above, and may be embodied as any type of volatile and / or non-volatile memory or data storage device capable of performing the functions described herein. In operation, memory 524 may store various data and software used during the operation of local computer device 504, such as operating systems, applications, executable software, programs, libraries, and drivers.

[0071] Now for reference Figures 6A to 6C In use, computer system 400 (for example, Figure 4 Hip prosthesis positioning analysis device 402 and / or Figure 5 The positioning analysis server 502 is configured to execute method 600 for determining patient-specific pelvic tilt measurements. If the patient-specific pelvic tilt measurements are outside a predetermined range, the computer system 400 may alert a user (e.g., a surgeon). Additionally, these (and other) patient-specific pelvic tilt measurements can be used to determine the position of the hip prosthesis 100, as discussed further below. Method 600, or portions thereof, may be embodied as a set of executable instructions stored on and executable by the computer system 400. Therefore, it should be understood that the operation of method 600 can be performed by one or more components of the analysis device 402 and / or means communicatively coupled to the analysis device 402.

[0072] Method 600 begins at block 602, where analysis device 402 acquires (e.g., captures, obtains, or receives) a set of medical images of the hip joint of a patient to be subjected to orthopedic surgery from imaging device 404. These medical images are embodied as images of the patient's hip joint, wherein the hip joint is positioned in various functional positions. Analysis device 402 can receive any type and number of suitable medical images that help determine patient-specific pelvic tilt measurements, as discussed in more detail below. For example, in the figures, the medical images are illustratively embodied as two-dimensional X-ray images. Alternatively or alternatively, other types of two-dimensional and / or three-dimensional medical images may be used. In some embodiments, one or more two-dimensional medical images can be generated from a three-dimensional medical image (e.g., a CT scan) by isolating slices of the three-dimensional medical image (e.g., slices parallel to the sagittal and / or coronal planes) and / or by projecting structures in the three-dimensional medical image onto a two-dimensional plane (to create a simulated X-ray image).

[0073] In an exemplary embodiment, the analysis device 402 acquires a seated medical image in block 604 and a standing medical image in block 606. The standing medical image may be a medical image of the patient's hip joint taken from the patient's sagittal plane while the patient is standing. Therefore, the standing medical image shows the sagittal profile of the patient's pelvis in a standing position. Figure 8 and Figure 9 An example of a standing medical image 802 is shown. A seated medical image can be represented as a medical image taken from the sagittal plane of a patient when the patient is in a seated position and the hip joint is in full flexion (e.g., the femur is bent at approximately 90 degrees relative to the standing position). Therefore, a seated medical image shows the sagittal profile of the pelvis of a patient in a seated position. Figure 7 An example of a seated medical image 702 is shown. In some embodiments of block 602, the analysis device 402 may acquire a standing medical image but not a seated medical image.

[0074] Box 602 may also involve acquiring other medical images of the patient's hip joint in the same and / or different functional positions, such as standing anteroposterior medical images, supine anteroposterior medical images, and sagittal standing contralateral flexion medical images. Anteroposterior medical images may be represented as medical images of the patient's hip joint taken from the coronal plane anterior to the patient, respectively, when the patient is standing or supine. In embodiments using a standing (rather than supine) reference frame to report the target orientation of the acetabular cup 104, supine anteroposterior medical images are advantageously not necessary and may be omitted. Sagittal standing contralateral flexion medical images may be represented as medical images taken from the patient's sagittal plane when the patient is standing, where the leg opposite the hip joint to which orthopedic surgery is being performed is positioned in a flexed position (e.g., where the opposing femur is flexed approximately 90 degrees relative to the standing position).

[0075] In the analysis device 402 Figure 6A After acquiring the medical image in box 602, the analysis device 402 analyzes the seated medical image in box 608. For this purpose, the analysis device 402 may identify one or more anatomical landmarks of the patient's bony anatomy in the seated medical image. Specifically, the analysis device 402 identifies one or more anatomical landmarks on the patient's pelvis. In some embodiments, the analysis device 402 may identify relevant anatomical landmarks based on annotations of the seated medical image provided by a surgeon, as further described below. Alternatively or additionally, in other embodiments, the analysis device 402 may be configured to automatically and / or autonomously identify relevant anatomical landmarks in the seated medical image in box 608. For example, in some embodiments of method 600, in box 608, the analysis device 402 may utilize a machine learning algorithm (of landmark model 432) to identify relevant anatomical landmarks in the seated medical image. In such embodiments, the machine learning algorithm may undergo a training phase in which a training set of medical images with surgeon annotations of sample patients is provided to the machine learning algorithm. In this way, the machine learning algorithm is trained to identify corresponding anatomical landmarks in new medical images, such as the current patient's medical image.

[0076] One or more anatomical landmarks identified in box 608 can be embodied as any anatomical landmark that facilitates or improves the determination of the patient's pelvic tilt measurement results. The specific landmarks used can depend on various factors, such as the patient's bone anatomy, the size and type of the hip prosthesis 100, and / or other factors. For example, in an exemplary embodiment of box 608, the analysis device 402 determines the patient's seated sacral slope, as shown in box 610. When the patient is in the seated position shown in the seated medical image, the seated sacral slope is defined by the superior margin of the patient's S1 endplate (i.e., the superior margin of the patient's sacrum, which can be identified as distal to the distal vertebral body L5). In an exemplary embodiment, the analysis device 402 provides a graphical user interface (GUI) through which a surgeon (or another user working under the surgeon's guidance) can annotate the seated medical image to identify the seated sacral slope. Figure 7 An example of the GUI 700 that computer system 400 can generate on display 416 is shown.

[0077] The GUI 700 includes a seated medical image 702 (or a related portion thereof) and instructs the surgeon to position a seated reference line 704 to define the slope and length of the S1 endplate. The entire length of the S1 endplate should be defined by the seated reference line 704, with a first end of the seated reference line 704 at the anterior margin and a second end of the seated reference line 704 at the posterior margin. This placement ensures that the midpoint and anterior point of the seated reference line 704 are sufficiently accurate for subsequent calculations. The seated reference line 704 should follow the S1 endplate as closely as possible, but in cases where the S1 endplate is curved or osteophytes are present, the surgeon may preferentially select accurate endpoints to approximate the slope as best as possible. To facilitate positioning the first end of the seated reference line 704 at the anterior margin of the S1 endplate, the GUI 700 provides two anchor points 706 ( Figure 7 Only one is marked in the text), and each anchor point can be selected and dragged by the user to move the first end. To facilitate positioning the second end of the seating reference line 704 at the trailing edge of the S1 end plate, the GUI 700 provides two anchor points 708 ( Figure 7 (Only one is marked in the text). Each anchor point can be selected and dragged by the user to move the second end. In addition, the GUI 700 provides a slider control that allows the user to adjust the contrast and brightness of the seated medical image 702 to facilitate the accurate positioning of the seated reference line 704.

[0078] When the user positions the seating reference line 704 across the upper edge of the S1 endplate of the patient shown in the seated medical image 702 via the GUI 700, the analysis device 402 receives this user input in box 612. Once the seating reference line 704 has been positioned, method 600 proceeds to box 614, where the analysis device 402 uses the seating reference line 704 to calculate the seated sacral slope. In an exemplary embodiment of box 614, the analysis device 402 calculates the seated sacral slope value as an angle (relative to the horizontal plane of the seated medical image 702) using the following formula: , The leftmost end of the seating reference line 704 in the image (i.e., the one with the smallest x-value) is assigned a coordinate point. Furthermore, the rightmost end of the seating reference line 704 in the image (i.e., the one with the largest x-value) is assigned a coordinate point. .

[0079] After analyzing the seated medical image in block 608, an exemplary embodiment of method 600 proceeds to block 616, where the analysis device 402 analyzes the standing medical image. (In other embodiments of method 600, block 616 may be performed before or concurrently with block 608.) In block 616, the analysis device 402 may identify one or more anatomical landmarks of the patient's bony anatomy in the standing medical image. Specifically, the analysis device 402 identifies one or more anatomical landmarks on the patient's pelvis. In some embodiments, the analysis device 402 may identify relevant anatomical landmarks based on annotations of the standing medical image provided by a surgeon, as further described below. Alternatively or additionally, in other embodiments, the analysis device 402 may be configured to automatically and / or autonomously identify relevant anatomical landmarks in the standing medical image in block 616. For example, in some embodiments of method 600, in block 616, the analysis device 402 may utilize a machine learning algorithm (of landmark model 432) to identify relevant anatomical landmarks in the standing medical image.

[0080] One or more anatomical landmarks identified in box 616 can be embodied as any anatomical landmark that facilitates or improves the determination of the patient's pelvic tilt measurement results. The specific landmarks used can depend on various factors, such as the patient's bone anatomy, the size and type of the hip prosthesis 100, and / or other factors. For example, in the exemplary embodiment of box 616, the analysis device 402 determines the patient's standing sacral slope (as shown in box 618) and femoral head center (as shown in box 626). When the patient is in the standing position shown in the standing medical image, the standing sacral slope is defined by the superior margin of the patient's S1 endplate (i.e., the superior margin of the patient's sacrum, which can be identified as distal to the distal vertebral body L5). In the exemplary embodiment, the analysis device 402 provides another GUI through which a surgeon (or another user working under the surgeon's guidance) can annotate the standing medical image to identify the standing sacral slope. Figure 8 An example of the GUI 800 that computer system 400 can generate on display 416 is shown.

[0081] The GUI 800 includes a standing medical image 802 (or a related portion thereof) and instructs the surgeon to position a standing reference line 804 to define the slope and length of the S1 endplate. The entire length of the S1 endplate should be defined by the standing reference line 804, with a first end of the standing reference line 804 at the anterior margin and a second end of the standing reference line 804 at the posterior margin. This placement ensures that the midpoint and anterior point of the standing reference line 804 are sufficiently accurate for subsequent calculations. The standing reference line 804 should follow the S1 endplate as closely as possible, but in cases where the S1 endplate is curved or osteophytes are present, the surgeon may preferentially select accurate endpoints to approximate the slope as best as possible. To facilitate positioning the first end of the standing reference line 804 at the anterior margin of the S1 endplate, the GUI 800 provides two anchor points 806 ( Figure 8 Only one is marked in the text), and each anchor point can be selected and dragged by the user to move the first end. To facilitate positioning the second end of the standing reference line 804 at the trailing edge of the S1 end plate, the GUI 800 provides two anchor points 808 ( Figure 8 (Only one is marked in the image), each anchor point can be selected and dragged by the user to move the second end. Additionally, the GUI 800 provides a slider control that allows the user to adjust the contrast and brightness of the standing medical image 802 to facilitate accurate positioning of the standing reference line 804.

[0082] When the user positions the standing reference line 804 across the upper edge of the S1 endplate of the patient shown in the standing medical image 802 via the GUI 800, the analysis device 402 receives this user input in box 620. Once the standing reference line 804 has been positioned, method 600 proceeds to box 622, where the analysis device 402 uses the standing reference line 804 to calculate the standing sacral slope. In an exemplary embodiment of box 622, the analysis device 402 calculates the standing sacral slope value as an angle (relative to the horizontal plane of the standing medical image 802) using the following formula: , The leftmost end of the standing reference line 804 in the image (i.e., the one with the smallest x-value) is assigned a coordinate point. Furthermore, the rightmost end of the standing reference line 804 in the image (i.e., the one with the largest x-value) is assigned a coordinate point. Box 618 also relates to box 624, in which the analysis device 402 calculates the midpoint of the sacral slope as the midpoint of a standing reference line 804 located by the user. In an exemplary embodiment of box 624, the analysis device 402 calculates the midpoint of the standing reference line 804 in Cartesian coordinates using the following formula: .

[0083] As described above, the exemplary embodiment of box 616 also relates to box 626, in which the analysis device 402 determines the femoral head center from a standing medical image. The femoral head center is defined as the midpoint between the corresponding rotation centers of the patient's femur (when the patient is in the standing position shown in the standing medical image). In the exemplary embodiment, the analysis device 402 provides another GUI through which a surgeon (or another user working under the surgeon's guidance) can annotate the standing medical image to identify the femoral head center. Figure 9 An example of the GUI 900 that computer system 400 can generate on display 416 is shown.

[0084] GUI 900 includes a standing medical image 802 (or a portion thereof) and instructs the surgeon to position reference circles 904A, 904B around each visible femoral head. In some cases, only one femoral head is visible in the standing medical image 802. In such cases, the surgeon can position reference circle 904A around the visible femoral head and remove the other reference circle 904B. To facilitate positioning around the femoral head, GUI 900 provides two anchor points 906, 908, as follows: Figure 9As shown. Anchor point 906 can be selected and dragged by the user to manipulate the position of the associated reference circle 904. Anchor point 908 can be selected and dragged by the user to change the size of the associated reference circle 904 while maintaining the current center point. In addition, GUI 900 provides a slider control that allows the user to adjust the contrast and brightness of the standing medical image 802 to facilitate accurate positioning of the reference circle 904.

[0085] When the user positions reference circle 904A and possibly reference circle 904B around the visible femoral head in the standing medical image 802 via GUI 900, the analysis device 402 receives this user input in box 628. Once reference circle 904 has been positioned, method 600 proceeds to box 630, where the analysis device 402 uses the center of reference circle 904 to record the center of the femoral head. In the case where the user places only a single reference circle 904A, in box 630, the analysis device 402 records the center of reference circle 904A as the center of the femoral head. Alternatively, in the case where the user places two reference circles 904A and 904B, the analysis device 402 calculates the midpoint of the femoral head in Cartesian coordinates using the following formula: , The center of reference circle 904A is assigned coordinate points. And coordinate points are assigned to the center of reference circle 904B. Then, this midpoint is recorded as the center of the femoral head.

[0086] In some embodiments of method 600, block 616 may also involve determining the anterior pelvic plane from the standing medical image 802. For example, the analysis device 402 may present another GUI that allows a surgeon to annotate the standing medical image 802 with reference point markers on the patient's pubic symphysis and two anterior iliac spines (ASIS) points. The surgeon may place these three reference point markers in any order. (Additionally or alternatively, in some embodiments, these three reference point markers may be placed automatically by the analysis device 402 using image analysis and machine learning.) Once the three reference point markers are placed, the analysis device 402 identifies the lowest marker as the pubic symphysis and the remaining two markers as ASIS points, and calculates the slope of the anterior pelvic plane of the patient in the standing position from these three reference point markers. The analysis device 402 also determines whether the patient's pelvis is facing left or right in the standing medical image 802 by comparing the relative position of the midpoint of the sacral slope to the midpoint between the two ASIS markers. The exemplary implementation of method 600 assumes that the patient's pelvis is a rigid body, such that the anterior pelvic plane of a patient in a seated position is equivalent to that of a patient in a standing position compared to a standing position, and the sacral slope of a patient in a seated position compared to a standing position. Therefore, the exemplary implementation of method 600 does not require the surgeon to annotate the anterior pelvic plane (or other anatomical features other than the sacral slope) on the seated medical image 702.

[0087] After analyzing the standing medical image in box 616, method 600 proceeds to box 632, where the analysis device 402 calculates the spinopelvic tilt of the pelvis of a patient in the standing position shown in the standing medical image. For this purpose, in box 632, the analysis device 402 defines a line between the midpoint of the sacral slope (from box 624) and the center of the femoral head (from box 630). The angle measured relative to this derived line with respect to a vertical line is the spinopelvic tilt associated with the patient's standing position. In an exemplary embodiment of box 632, the analysis device 402 calculates the spinopelvic tilt value as an angle in degrees (relative to the vertical plane of the standing medical image 802) using the following formula: in It is the coordinate point of the midpoint of the sacral slope (from box 624), and This is the coordinate point of the center of the femoral head (from box 630). When the midpoint of the sacral slope is posterior to the center of the femoral head, it is a positive spinopelvic tilt value, and when the midpoint of the sacral slope is anterior to the center of the femoral head, it is a negative spinopelvic tilt value. Therefore, for a left-facing pelvis in a standing medical image, the spinopelvic tilt value is multiplied by -1. For a right-facing pelvis in a standing medical image, the original landmarks are preserved.

[0088] After calculating the spinopelvic tilt value of the standing medical image in box 632, method 600 proceeds to box 634, where the analysis device 402 calculates the patient-specific pelvic angle of incidence. This pelvic angle of incidence is defined as the angle between a line derived from box 632 (extending between the midpoint of the sacral slope and the center of the femoral head) and a conceptual line perpendicular to the standing sacral slope at the midpoint of the sacral slope. In an exemplary embodiment of box 634, the analysis device 402 calculates the pelvic angle of incidence value by summing the standing sacral slope value (from box 622) and the spinopelvic tilt value (from box 632). In an exemplary embodiment, each of the pelvic angle of incidence value, the standing sacral slope value, and the spinopelvic tilt value is an angle expressed in degrees. Because the labels of the standing sacral slope value and the spinopelvic tilt value have been corrected to match the coordinate system, the label of the pelvic angle of incidence value will be accurate.

[0089] In an exemplary embodiment, after calculating the pelvic incidence angle in box 634, method 600 proceeds to box 636, where the analysis device 402 calculates patient-specific pelvic mobility. In other embodiments of method 600, box 636 can be performed at any time after calculating the seated sacral slope (box 614) and after calculating the standing sacral slope (box 622). This pelvic mobility is defined as the angle between the seated sacral slope and the standing sacral slope. In an exemplary embodiment of box 636, the analysis device 402 calculates the pelvic mobility value by subtracting the standing sacral slope value (from box 622) from the seated sacral slope value (from box 614). In an exemplary embodiment, each of the pelvic mobility value, the standing sacral slope value, and the seated sacral slope value is an angle expressed in degrees. While the exemplary implementation uses seated and standing sacral inclinations to calculate pelvic mobility, it is envisioned that similar calculations could be performed using other pelvic features identifiable in both seated and standing medical images. For example, in a collection of seated and standing medical images, an anterior pelvic plane could be identified at each location, and these two anterior pelvic planes could be used to determine patient-specific pelvic mobility.

[0090] After calculating pelvic mobility in block 636, method 600 proceeds to block 638, whereby analysis device 402 generates a user alert if the patient's pelvic mobility is outside a predetermined range. In an exemplary embodiment, analysis device 402 compares the pelvic mobility value (here, an angle expressed in degrees) calculated in block 636 with a range of 10 to 35 degrees (including endpoint values). It should be understood that in other embodiments, this range may have different values ​​at its lower end and / or different values ​​at its upper end. If the calculated pelvic mobility value is within this range, analysis device 402 may notify the user that the patient's pelvic mobility is within the normal range. However, in response to a pelvic mobility value outside this range, analysis device 402 will generate a user alert. User alerts may take any number of forms, including visual and / or audio alerts generated on any part of computer system 400. In some embodiments, user alerts may be manifested as icons that appear, change, or are highlighted on a graphical user interface.

[0091] In an exemplary embodiment of block 638, the analysis device 402 generates different user alerts based on whether the patient's pelvic mobility is above or below a predetermined range. If the calculated pelvic mobility value is less than the lower end of the predetermined range (e.g., less than 10 degrees), the analysis device 402 executes block 640, where the computer system 400 displays a message indicating that the patient has a rigid spine. In an exemplary embodiment of block 640, the computer system 400 displays the following message on the GUI: "The patient has a rigid spine. This has been taken into account in the target area by the algorithm. If the implant cannot be oriented in the patient's target area (e.g., dual mobility, lip liner, etc.), this can be given special consideration when making implant selection." In other embodiments, different messages (or another type of alert, such as icons) related to a patient with a rigid spine may be displayed in block 640.

[0092] On the other hand, if the calculated pelvic mobility value is greater than the upper end of a predetermined range (e.g., greater than 35 degrees), the analysis device 402 executes block 642, where the computer system 400 displays a message indicating that the patient has an overactive spine. In an exemplary embodiment of block 642, the computer system 400 displays the following message on the GUI: “The patient has an overactive spine. This has been taken into account in the target area by the algorithm. If the implant cannot be oriented in the patient’s target area (e.g., dual mobility, lip liner, etc.), this can be given special consideration when making implant selection.” In other embodiments, different messages (or another type of alert, such as an icon) related to a patient with an overactive spine may be displayed in block 642. In some embodiments of method 600, the surgeon may select a new hip prosthesis 100 of a different type and / or size than the initially selected hip prosthesis 100 in response to receiving a user alert in block 638.

[0093] Following box 638 (or at any other time after calculating the pelvic angle of incidence in box 634), method 600 may proceed to box 644, where the analysis device 402 generates a user alert if the patient's pelvic angle of incidence is outside a predetermined range. In an exemplary embodiment, the analysis device 402 compares the pelvic angle of incidence value (here, an angle expressed in degrees) calculated in box 634 with a range of 45 to 65 degrees (including endpoint values). It should be understood that in other embodiments, this range may have different values ​​at its lower end and / or different values ​​at its upper end. If the calculated pelvic angle of incidence value is within this range, the analysis device 402 may notify the user that the patient's pelvic angle of incidence is within the normal range.

[0094] However, in response to a pelvic angle of incidence value outside this range, the analysis device 402 will generate a user alert. The user alert can take any number of forms, including visual and / or audio alerts generated on any part of the computer system 400. In some embodiments, box 644 may relate to box 646, where the computer system 400 displays a message advising the surgeon to assess the patient's risk of bone-on-bone impingement intraoperatively. In an exemplary embodiment of box 646, the computer system 400 displays the message: "The patient has a [high / low] pelvic angle of incidence. Literature suggests that the patient may have an increased risk of bone-on-bone impingement, which should be assessed intraoperatively." This message may be displayed on the computer system 400 preoperatively and / or intraoperatively (including during orthopedic procedures) as a reminder to the surgeon. In other embodiments, the user alert may be embodied as an icon that appears, changes, or is highlighted on a graphical user interface. In some embodiments of method 600, the surgeon may perform an intraoperative assessment of the patient's risk of bone-on-bone impingement in response to receiving the user alert in box 644.

[0095] Now for reference Figures 10A to 10B In use, computer system 400 (for example, Figure 4 Hip prosthesis positioning analysis device 402 and / or Figure 5 The positioning analysis server 502 is also configured to execute method 1000, which is used to determine and present multiple sets of target orientations of the acetabular cup 104 corresponding to the femoral prosthesis 102 with different tilt orientations. Method 1000 or parts thereof may be embodied as a set of executable instructions stored on and executable by computer system 400. Therefore, it should be understood that the operation of method 1000 may be performed by one or more components of analysis device 402 and / or means communicatively coupled to analysis device 402.

[0096] Patient-specific pelvic tilt measurements determined by method 600, along with other parameters related to the patient's anatomy, planned orthopedic surgery, and the hip prosthesis 100, are fed into method 1000. For example, in addition to the patient-specific pelvic tilt measurements discussed above, analysis device 402 may request the surgeon to annotate various anatomical landmarks on anteroposterior (AP) medical images taken with the patient in a standing and / or supine position. These annotations can be used to generate inputs for method 1000 and / or facilitate the presentation of the results of method 1000 in standing and / or supine reference frames. As described above, in embodiments using a standing reference frame, methods 600 and 1000 may advantageously not require obtaining or annotating any supine medical images.

[0097] The analysis device 402 also requires the surgeon to input the type and size of the hip prosthesis 100 (including the femoral prosthesis 102 and the acetabular cup 104) to be used during orthopedic surgery. The surgeon can select the type and size from a menu of available types and sizes, or otherwise provide those selections to the analysis device 402. The selection of the type and size of the hip prosthesis 100 provides the method 1000 with data on the hip prosthesis 100, including geometric measurements. These geometric measurements may exemplify measurements of the inner diameter of the acetabular cup 104 (i.e., the cup liner 122), the outer diameter of the acetabular cup 104, the proximal-distal distance from the medial edge of the cup liner 122 of the acetabular cup 104 to the center of rotation of the femoral head 118 of the femoral prosthesis 102, the proximal-distal distance from the lateral edge of the cup liner 122 of the acetabular cup 104 to the center of rotation of the femoral head 118 of the femoral prosthesis 102, and the neck angle (e.g., the longitudinal angle relative to the stem 110) of the femoral prosthesis 102. In some embodiments, the analysis device 402 may retrieve those geometric measurements from a database based on the type and size of the hip prosthesis 100 selected by the surgeon. Alternatively, in other embodiments, the geometric measurements may be manually entered by the orthopedic surgeon or other user. In other embodiments, geometric measurements may be determined based on a three-dimensional model or engineering drawing of the selected hip prosthesis 100 (i.e., femoral prosthesis 102 and acetabular cup 104), including metadata files associated with such model or drawing.

[0098] Method 1000 begins at frame 1002, where analysis device 402 determines a set of target orientations for the acetabular cup 104 for each of a plurality of femoral prosthesis tilts (each target orientation is a pair of anteversion and tilt values). Femoral prosthesis tilt (sometimes also called femoral neck anteversion (FNA) or femoral tilt) is the angle between the projections of two lines into an axial plane perpendicular to the femoral axis: one line passes through the proximal femoral neck region, and the second line passes through the distal condylar region, indicating the degree of femoral “torsion.” Femoral prosthesis tilt affects the biomechanics of the hip because the moment arm and the line of action of the muscles around the joint are altered. When performing total hip arthroplasty, the surgeon can choose which tilt to orient the femoral prosthesis 102 among a plurality of different tilts.

[0099] In an exemplary embodiment, block 1002 relates to determining a set of target orientations for the acetabular cup 104 for each of five possible tilts of the femoral prosthesis 102, specifically -5 degrees, 5 degrees, 15 degrees, 25 degrees, and 35 degrees. Based on current medical literature, these tilt values ​​are chosen to represent the mean femoral prosthesis tilt (15°), ± approximately 1 standard deviation from that mean (5°, 25°), and ± approximately 2 standard deviations from that mean (-5°, 35°). It is envisioned that other embodiments may use a different solution space for femoral prosthesis tilt, including different tilt values ​​and / or different numbers of options for femoral prosthesis tilt. For example, in some embodiments, when determining the first set of target orientations for the acetabular cup 104, the analysis device 402 may utilize the patient's natural preoperative femoral tilt as the initial femoral prosthesis tilt. The analysis device 402 may then use additional femoral prosthesis tilts, both higher and lower than this initial femoral prosthesis tilt, to determine additional sets of target orientations for the acetabular cup 104. In such implementations, method 1000 may involve measuring the preoperative tilt of a patient’s natural femur from one or more medical images obtained by analysis device 402 (e.g., from a CT scan).

[0100] Box 1002 can use any suitable algorithm to determine a set of target orientations of the acetabular cup 104 in the solution space for each femoral prosthesis tilt. For example, in box 1002, multiple sets of target orientations of the acetabular cup 104 can be determined using any of the methods described in the following documents: U.S. Patent Application Publications Nos. 2022 / 0202494 and 2022 / 0202503, published June 30, 2022, and PCT International Publication No. WO 2022 / 144448, published July 7, 2022 (the entire disclosures of which are incorporated herein by reference). As described in the foregoing references, some embodiments of box 1002 can determine each set of target orientations of the acetabular cup 104 by predicting a set of orientations of the acetabular cup 104 that will not result in edge loading of the femoral prosthesis 102 on the acetabular cup 104 or impingement of the femoral prosthesis 102 and the acetabular cup 104 when the femoral prosthesis is in the corresponding tilt orientation. References below Figure 10A Boxes 1004 to 1016 describe an exemplary implementation of such an algorithm.

[0101] In an exemplary implementation, box 1002 begins with box 1004, wherein the following inputs are supplied to contact model 434: a set of candidate orientations of acetabular cup 104 (e.g., 2,091 candidate orientations given for each pair of integer values ​​of tilt between 20 and 60 degrees and anteversion between 0 and 50 degrees), patient-specific pelvic tilt measurements (e.g., pelvic angle of incidence and pelvic mobility values ​​discussed above), and type and size data of hip prosthesis 100 (e.g., geometric data regarding the dimensions of femoral prosthesis 102 and acetabular cup 104). Contact model 434 is exemplary embodied as a regression model that predicts for each set of input conditions how close the load of the femoral head 118 of femoral prosthesis 102 on the acetabular cup liner 122 of acetabular cup 104 will be to the edge of the supporting surface of acetabular cup liner 122 in different functional positions of the patient.

[0102] Following box 1004, the exemplary implementation of box 1002 proceeds to box 1006, where the analysis device 402 operates the contact model 434 to generate two predicted distances for each candidate orientation of the acetabular cup 104: (i) the closest distance between the edge of the cup liner 122 of the acetabular cup 104 and the predicted contact location between the cup liner 122 and the femoral head 118 of the femoral prosthesis 102 when the patient is in a standing position, and (ii) the closest distance between the edge of the cup liner 122 of the acetabular cup 104 and the predicted contact location between the cup liner 122 and the femoral head 118 of the femoral prosthesis 102 when the patient is in a seated position (e.g., seated with the hip fully flexed, as discussed above). Because the contact model 434 has been specifically configured to generate this data based on the provided input, box 1006 can be performed locally in real time by the analysis device 402 without computationally intensive modeling of the joint and hip prosthesis 100.

[0103] Following box 1006, the exemplary embodiment of box 1002 proceeds to box 1008, where the analysis device 402 compares the predicted distances generated by the contact model 434 for each candidate orientation of the acetabular cup 104 with one or more thresholds. For example, in box 1008, each predicted distance may be compared with a threshold between 0 mm and 2 mm. If both predicted distances associated with a particular candidate orientation of the acetabular cup 104 are greater than the threshold, the candidate orientation is identified as not causing edge loading and is selected for further processing by the algorithm. If either predicted distance associated with a particular candidate orientation is less than the threshold, the candidate orientation is not considered further and cannot be part of a set of target orientations of the acetabular cup 104 in that pass of the algorithm. It is envisioned that, in box 1008, some embodiments may use multiple thresholds, including thresholds that vary based on the size and / or type of the hip prosthesis 100.

[0104] Following box 1008, an exemplary implementation of box 1002 proceeds to box 1010, wherein the following inputs are supplied to the impingement model 436: the selected candidate orientations of the acetabular cup 104 (i.e., those orientations that satisfy the thresholds applied in box 1008), the same patient-specific pelvic tilt measurements and the same hip prosthesis 100 type and size data supplied to the contact model 434 in box 1004, and femoral prosthesis tilt (e.g., planned tilt of the femoral prosthesis) that determines a set of target orientations of the acetabular cup 104. The impingement model 436 is illustratively embodied as a regression model that predicts, for each set of input conditions, how far the femoral prosthesis 106 can rotate before impinging on the acetabular cup 104 in different functional positions of the patient.

[0105] Following box 1010, an exemplary implementation of box 1002 proceeds to box 1012, where analysis device 402 operates impingement model 436 to generate two predicted values ​​for each selected candidate orientation of acetabular cup 104: (i) the amount by which the femoral prosthesis 106 can rotate externally before impinging with acetabular cup 104 when the patient is in a standing position, and (ii) the amount by which the femoral prosthesis 106 can rotate internally before impinging with acetabular cup 104 when the patient is in a seated position (e.g., seated with the hip fully flexed, as discussed above). Because impingement model 436 has been specifically configured to generate this data based on the provided input, box 1012 can be performed locally in real time by analysis device 402 without computationally intensive modeling of the joint and hip prosthesis 100.

[0106] Following box 1012, the exemplary embodiment of box 1002 proceeds to box 1014, where the analysis device 402 compares the predicted rotation amounts generated by the impingement model 436 for each selected candidate orientation of the acetabular cup 104 with one or more thresholds. If both predicted rotation amounts associated with a particular selected candidate orientation of the acetabular cup 104 are greater than the applicable threshold, the selected candidate orientation is identified as not causing implant impingement and is included in a set of target orientations of the acetabular cup 104 in that iteration of the algorithm. If either predicted rotation amount associated with a particular selected candidate orientation is less than the applicable threshold, the selected candidate orientation is not included in a set of target orientations of the acetabular cup 104 in that iteration of the algorithm. In the exemplary embodiment of box 1014, those thresholds are dynamically updated based on whether the thresholds used to evaluate the predicted rotation amounts of each selected candidate orientation produce a sufficient number of target orientations for the acetabular cup 104. For example, if the default value of the thresholds applied in box 1014 does not produce a sufficient number of target orientations, the thresholds are incrementally reduced and box 1014 is executed again. The process is repeated iteratively until box 1014 produces a sufficient number of target orientations for the acetabular cup 104, or until the algorithm determines that it cannot produce a sufficient number of target orientations for the current set of input conditions.

[0107] Therefore, each of the selected candidate orientations that satisfies the threshold of box 1014 is identified as an orientation of the acetabular cup 104 that will not cause edge loading of the femoral prosthesis 102 onto the acetabular cup 104 or impact between the femoral prosthesis 102 and the acetabular cup 104 when the femoral prosthesis 102 is in the corresponding tilt orientation. The set of these orientations forms a set of target orientations of the acetabular cup 104 for the corresponding femoral prosthesis tilt. In box 1016, the femoral prosthesis tilt can be updated to different femoral prosthesis tilts in the solution space, and boxes 1004 to 1014 can be repeated for that femoral prosthesis tilt. In other embodiments, the system can determine multiple sets of target orientations of the acetabular cup 104 corresponding to all femoral prosthesis tilts in the solution space in parallel rather than sequentially.

[0108] Following box 1002, an exemplary implementation of method 1000 proceeds to... Figure 10B Box 1020, as shown, contains a GUI displaying some results of the algorithm running in box 1002, presented by the analysis device 402. Figure 11 The diagram shows an exemplary example of the GUI 1100 that can be displayed in box 1020. Figure 11 The GUI 1100 includes a medical image 1102 of the patient's hip (illustratively an anteroposterior supine X-ray, since the result of the algorithm running in box 1002 is presented from the supine reference frame in the GUI 1100). The medical image 1102 in the GUI 1100 has been annotated with a template 1104 for the hip prosthesis 100 to be implanted in the patient's right hip. Template 1104 includes a femoral prosthesis template 1106 and an acetabular cup template 1108. The orientation of the acetabular cup template 1108 in the GUI 1100 reflects the default target orientation 1110 of the acetabular cup 104 (discussed further below). The GUI 1100 also includes patient information 1112, certain type and size data of the hip prosthesis 100 1114, biomechanical information 1116 related to changes in the patient's biomechanics that can be anticipated from the current surgical planning, and pelvic tilt measurements 1118 (including, but not limited to, one or more pelvic tilt measurements determined during the above method 600).

[0109] like Figure 11As shown, GUI 1100 also includes a graph 1120 representing one of the target orientations of the acetabular cup 104 defined in box 1002. Graph 1120 illustratively includes a tilt axis 1122, a yaw axis 1124, and a closed shape 1126 that, when drawn relative to the tilt axis 1122 and the yaw axis 1124, surrounds the represented set of target orientations of the acetabular cup 104. The set of target orientations of the acetabular cup 104 can be represented in graph 1120 by the closed shape 1126 because outlier orientations lacking sufficient neighbors are excluded from this set of target orientations. Graph 1120 also includes a marker 1128 indicating the centroid of the closed shape 1126, which the algorithm renders as the default target orientation 1110 and is marked as "optimal orientation" in interface element 1130 of GUI 1100. As used in this article, an “interface element” can be represented as one or more text characters (including letters and / or numbers), one or more graphics (e.g., shapes, pictures, etc.), or any combination of text and graphics.

[0110] Several interface elements 1132 of the GUI 1100 allow the user to increment or decrement the tilt or rotation of the default target orientation 1110 to create a selected target orientation different from the planned orientation of the acetabular cup 104. For example, if the user adjusts by incrementing the tilt by 4 degrees (from 43 degrees to 47 degrees) and the rotation by 6 degrees (from 30 degrees to 36 degrees). Figure 7 If the default target orientation 1110 is shown in the GUI 1100, the analysis device 402 will display an updated GUI 1200, such as... Figure 12 As shown, GUI 1200 displays the newly selected target orientation 1210 (47-degree tilt, 36-degree rotation) of the acetabular cup 104. Marker 1128 on graph 1120 is replaced by a new mark 1228 indicating the selected target orientation 1210 on graph 1120. (This new mark 1228 is no longer the centroid of the closed shape 1126.) In some embodiments, the orientation of the acetabular cup template 1108 overlaid on the medical image 1102 in GUI 1200 can be updated to reflect the selected target orientation 1210 of the acetabular cup 104. Interface element 1130 is replaced by another interface element 1230 to indicate that the selected target orientation 1210 is no longer the "optimal orientation". Interface element 1230 illustratively reads "Reset Orientation" and can be selected by the user to return to the default target orientation 1110 (43-degree tilt, 30-degree rotation). Figure 11 GUI 1100.

[0111] like Figure 11 and Figure 12As shown, GUIs 1100 and 1200 also include interface elements 1140 and 1142 associated with various femoral prosthesis tilts, generating multiple target orientations of the acetabular cup 104 for these femoral prosthesis tilts in box 1002. Interface element 1140 indicates that the graphics 1120 and 1220 actively displayed on each GUI 1100 and 1200 (representing a set of target orientations of the acetabular cup 104) correspond to the femoral prosthesis 102 with a tilt orientation of 15 degrees. (As discussed above, in other embodiments, this initial femoral prosthesis tilt may correspond to the patient's natural preoperative femoral tilt, rather than a default value such as 15 degrees.) In an exemplary embodiment, interface element 1140 includes a solid circle next to the text "15°". Interface element 1142 (illustrated as hollow circles next to the text "-5°", "5°", and "25°") each indicates another set of target orientations of the acetabular cup 102, also generated in box 1002 but corresponding to different femoral prosthesis tilts, which are available for viewing. For example, in Figure 11 and Figure 12 In the interface element 1142, multiple sets of target orientations of the acetabular cup 102 corresponding to the femoral prosthesis with each of the following orientations: -5 degrees tilt, 5 degrees tilt, and 25 degrees tilt, are available for user viewing. As described above, different implementations can utilize different solution spaces for femoral prosthesis tilt.

[0112] As described above, in some cases, box 1002 may not be able to determine a sufficient set of target orientations for the acetabular cup 104 for each femoral prosthesis tilt in the solution space. For example, the algorithm may determine that the number of orientations of the acetabular cup 104 that will not result in edge loading of the femoral prosthesis 102 on the acetabular cup 104 and impingement of the femoral prosthesis 102 and the acetabular cup 104 when the femoral prosthesis 102 is in a particular tilt orientation is insufficient. In other words, the number of target orientations of the acetabular cup 104 when the femoral prosthesis is in that particular tilt orientation is below the threshold required for the software to generate a “patient target area”. In such cases, the resulting GUI may include interface elements that indicate that the analysis device 402 cannot generate a sufficient set of target orientations for the acetabular cup 104 when the femoral prosthesis is in that tilt orientation. Figure 11 and Figure 12 As shown, for example, GUIs 1100 and 1200 each include an interface element 1144 that indicates that a 35-degree femoral implant tilt does not produce a sufficient set of target orientations for the acetabular cup 104 in frame 1002. In an exemplary embodiment, the interface element 1144 is represented as a hollow circle next to the text "35°", wherein both the hollow circle and the text are colored red to distinguish interface element 1144 from interface element 1142.

[0113] Following box 1020, an exemplary embodiment of method 1000 proceeds to box 1022, where the analysis device 402 receives user input associated with one of the interface elements 1142. For example, box 1022 may involve a user clicking one of the interface elements 1142 with a mouse pointer or touching one of the interface elements 1142 with a finger or stylus (e.g., where GUI 1100 is displayed on a touchscreen). The analysis device 402 interprets this user input as an indication that the user expects to view a set of different target orientations of the acetabular cup 102 generated in box 1002 and associated with the selected interface element 1142. In an exemplary embodiment of method 1000, each of the multiple sets of different target orientations of the acetabular cup 102 is determined in box 1002 before receiving user input in box 1022, allowing a new set of target orientations to be displayed almost immediately after receiving user input.

[0114] In response to receiving user input in box 1022, method 1000 proceeds to box 1024, which displays an updated or new GUI that presents additional results of the algorithm run in box 1002. Figure 13 The diagram shows an exemplary example of a GUI 1300 that can be displayed in box 1024. Aside from the differences described below, Figure 13 The GUI1300 is similar to Figure 11The GUI 1100. Graph 1120 of GUI 1100 is replaced by graph 1320 of GUI 1300. Similar to graph 1120, graph 1320 includes a tilt axis 1122 and a yaw axis 1124. However, graph 1320 includes a different closed shape 1326 because graph 1320 represents a set of target orientations of the acetabular cup 104 that are different from the target orientations represented by the closed shape 1126 of graph 1120. The closed shape 1326 is drawn around the set of target orientations represented by the acetabular cup 104 when drawn relative to the tilt axis 1122 and the yaw axis 1124. A set of target orientations of the acetabular cup 104 can be represented by the closed shape 1326 in graph 1320 because outlier orientations lacking sufficient neighbors are excluded from this set of target orientations. Graphic 1320 also includes a marker 1328 indicating the centroid of the closed shape 1326, which the algorithm renders as the default target orientation 1310 and is marked as "optimal orientation" in interface element 1130 of GUI 1300. Interface element 1142 associated with a 25-degree femoral prosthesis tilt in GUI 1100 is replaced by interface element 1140 (illustratively, a solid circle next to the text "25°"), which indicates that graphic 1320 actively displayed on GUI 1300 corresponds to a femoral prosthesis 102 with a 25-degree tilt orientation. Interface element 1140 associated with a 15-degree femoral prosthesis tilt in GUI 1100 is replaced by interface element 1142 (illustratively, a hollow circle next to the text "15°"), which indicates that the dataset is no longer actively displayed but is available for viewing.

[0115] In some implementations, after box 1024, method 1000 may proceed to box 1026, where the analysis device 402 receives user input associated with one of the interface elements 1142 in the GUI 1300. For example, box 1022 may involve a user clicking one of the interface elements 1142 with a mouse pointer or touching one of the interface elements 1142 with a finger or stylus (e.g., where the GUI 1300 is displayed on a touchscreen). The analysis device 402 interprets this user input as an indication that the user expects to view a different set of target orientations of the acetabular cup 102 generated in box 1002 and associated with the selected interface element 1142. For example, if the user input in box 1026 is associated with an interface element 1142 representing an initial femoral prosthesis tilt value (e.g., 15°), method 1000 returns to box 1020 and displays again. Figure 11The GUI 1100. Alternatively, if the user input in box 1026 is associated with another interface element in interface element 1142 of GUI 1300, method 1000 effectively returns to box 1024, but displays a different GUI (not shown) corresponding to, for example, a femoral implant tilt of -5 degrees or 5 degrees. Again, each of the multiple sets of different target orientations of the acetabular cup 102 can be determined in box 1002 before receiving user input in box 1026, which allows a new set of target orientations to be displayed almost immediately after receiving user input.

[0116] If the user selects interface element 1144, the analysis device 402 can display an updated or new GUI that indicates an algorithm that identifies an insufficient number of orientations for the acetabular cup 104 that will not result in rim loading of the femoral prosthesis 102 on the acetabular cup 104 and impact between the femoral prosthesis 102 and the acetabular cup 104 when the femoral prosthesis 102 is in an associated tilt orientation. Figure 14 The diagram shows an exemplary example of a GUI 1400 that can be displayed in response to a user selection of interface element 1144. Apart from the differences described below, Figure 14 The GUI 1400 is similar to Figure 11 The GUI 1100 is replaced by the graphic 1120 of the GUI 1400. Similar to graphic 1120, graphic 1420 includes a tilt axis 1122 and a rotation axis 1124. However, graphic 1420 does not include a closed shape because the algorithm does not output a set of target orientations for the acetabular cup 104 for the tilt of the femoral prosthesis. Interface element 1130 of GUI 1100 is replaced by another interface element 1430 in GUI 1400 to indicate that there is a "no feasible target" for the tilt of the femoral prosthesis. Similarly, target orientation 1110 of GUI 1100 is replaced by an empty placeholder 1410 in GUI 1400. Additionally, interface element 1144 of GUI 1400 is replaced by interface element 1440 (illustratively, a solid circle next to the text "35°"), which indicates that the graphic 1420 actively displayed on GUI 1100 corresponds to the femoral prosthesis 102 with a 35-degree tilt orientation. In an exemplary embodiment, the solid circle and text of interface element 1440 are colored red to distinguish interface element 1440 from interface element 1140 (see [link to documentation]). Figures 11 to 13The interface element 1140 associated with the 15-degree femoral prosthesis tilt in GUI 1100 is replaced by interface element 1142 (illustratively, a hollow circle next to the text "15°"), which indicates that the dataset is no longer actively displayed but is available for viewing. Finally, GUI 1400 illustratively includes a pop-up window titled "No Feasible Target Area" that presents the user with several suggestions for successfully identifying the target orientation of the acetabular cup 102.

[0117] In addition to the "orientation" information discussed above, the exemplary GUIs 1100, 1200, 1300, and 1400 also each include a "risk factors" label, such as... Figures 11 to 14 As shown. Users can select the "Risk Factors" tab to view various messages output by the algorithm, including the one mentioned above. Figure 6C The messages discussed in boxes 638 to 646.

[0118] When displaying multiple target orientations of the acetabular cup 104, alternative embodiments of method 1000 may additionally include one or more target boundaries. For example, Figures 15A to 15D Various alternative drawings 1120A to 1120D are shown, which illustrate (or explain) the target boundary and can be included in GUI 1100 in place of drawing 1120 described above. Although Figures 15A to 15D Different methods of including target boundaries relative to figure 1120 are shown, but it should be understood that one or more target boundaries can be similarly included in any figure shown or described in this disclosure (such as, for example, figures 1220, 1320). Furthermore, while alternative figures 1120A through 1120D each illustratively include two target boundaries, it is contemplated that any number of target boundaries may be used in different embodiments.

[0119] exist Figure 15A An alternative drawing 1120A is shown to represent one set of target orientations of the acetabular cup 104 determined in block 1002 of method 1000. Figure 15BAnother alternative drawing 1120B is shown to represent the same set of target orientations for the acetabular cup 104. Similar to drawing 1120, alternative drawings 1120A and 1120B each include a tilt axis 1122, a rotation axis 1124, a closed shape 1126 (representing the set of target orientations around the acetabular cup 104 when drawn relative to the tilt axis 1122 and the rotation axis 1124), and a marker 1128 positioned at the centroid of the closed shape 1126, each of which has been described in detail above. Alternative drawings 1120A and 1120B both present the patient target area in a supine reference frame, similar to drawing 1120. However, in contrast to drawing 1120, alternative drawings 1120A and 1120B each additionally include a line 1550 representing the minimum target boundary and a line 1552 representing the maximum target boundary. Although lines 1550 and 1552 have similar appearances in the exemplary embodiments, it is contemplated that in other embodiments, these lines may have different colors, shades, shading lines, patterns and / or labels to indicate different target boundaries represented by each line.

[0120] Lines 1550 and 1552 respectively represent corresponding target boundaries drawn relative to the tilt axis 1122 and rotation axis 1124 of figures 1120A and 1120B. Each target boundary reflects a specific constraint on the positioning of the acetabular cup 104. For example, each target boundary may reflect a minimum or maximum permissible value of tilt or inclination of the acetabular cup 104 relative to a specific reference frame (e.g., relative to a specific functional position of the patient's pelvis). The target boundaries may also be based on both tilt and inclination of the acetabular cup 104, for example, a specific relationship between tilt and inclination of the acetabular cup 104. The constraints captured in the target boundaries may be derived from medical literature and / or studies. For example, in an exemplary embodiment, one target boundary (represented by line 1550) is predefined to represent a minimum permissible tilt of 10 degrees for the acetabular cup 104 when the patient is in a flexed seated position, while another target boundary (represented by line 1552) is predefined to represent a maximum permissible tilt of 30 degrees for the acetabular cup 104 when the patient is in a standing position. These two target boundaries are derived from J.W. Pierrepont's doctoral dissertation, "Patient-Specific Component Alignment in Total Hip Arthroplasty," The University of Sydney, June 2017. In other implementations, alternative target boundaries representing other constraints derived from different medical literature or studies may be used.

[0121] It is also envisioned that the target boundaries could be user-defined to reflect the constraints on the preferred positioning of the acetabular cup 104 by a particular surgeon (or group of surgeons) using systems 400 and 500. For example, if a surgeon using systems 400 and 500 prefers to avoid a placement of the acetabular cup 104 that would result in a tilt or inclination greater than or less than a specific value when the patient is in a certain functional position (e.g., seated, standing, etc.), then target boundaries could be defined to represent that surgeon's preference. In various embodiments, one or more target boundaries can be entirely user-defined, entirely predefined based on values ​​obtained from medical literature and / or studies, or a combination of user-defined and predefined values ​​obtained from medical literature and / or studies.

[0122] When a target boundary is defined solely based on tilt or inclination within the same frame of reference (e.g., a supine or standing frame of reference as described above) where one or more target orientations of the acetabular cup 104 are displayed to the user, the straight line representing that target boundary can be superimposed on a two-dimensional diagram drawn by the tilt axis 1122 and the rotation axis 1124. While such a target boundary may be defined only relative to one axis (e.g., a minimum acetabular cup tilt of 5 degrees when the patient is standing), the line representing that target boundary will typically have a slope because the apparent value of the acetabular cup tilt changes with the increase or decrease of the acetabular cup tilt due to the projection of the three-dimensional structure onto the two-dimensional image.

[0123] When a target boundary is defined in a different reference system than the set of target orientations used to display the acetabular cup 104, the target boundary must be converted between the two reference systems before it can be drawn relative to the tilt axis 1122 and the rotation axis 1124. For example, if the patient target area is presented in a supine reference system (as in figures 1120A, 1120B) but the target boundary is defined relative to a standing or flexed-sitting reference system (such as a minimum permissible rotation of 10 degrees for the acetabular cup 104 when the patient is in a flexed-sitting position, or a maximum permissible rotation of 30 degrees for the acetabular cup 104 when the patient is in a standing position, as described above), the target boundary must be converted to the supine reference system before it can be added to the figure displaying the patient target area. This conversion between different reference systems is based on the pelvic mobility of a particular patient, meaning that the same target boundary will be represented by lines positioned at different locations relative to the tilt axis 1122 and the rotation axis 1124 of different patients. When the target boundary defined in one reference frame is transformed to another reference frame to be displayed relative to the tilt axis 1122 and the rotation axis 1124, the systems 400, 500 can utilize the pelvic tilt measurement results determined during method 600, as described above.

[0124] Furthermore, there is a non-linear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation. Therefore, the line reflecting this non-linear relationship relative to the tilt axis 1122 and the rotation axis 1124 will typically be curved (similar to...). Figures 15A to 15C The illustrative implementations show curves 1550 and 1552. It should be understood that the shape of the curves will vary depending on the specific circumstances, as it depends on the patient's specific pelvic mobility. Again, when converting between different reference frames, systems 400 and 500 can utilize the pelvic tilt measurements determined during method 600. It is also envisioned that some implementations may use a straight line, approximating the more complex relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation, instead of using curves to represent the converted target boundary. It is also possible that a more complex target boundary based on both tilt and rotation in one reference frame could become a straight line when converted to a different reference frame.

[0125] exist Figure 15A and Figure 15B In the illustrative case depicted, lines 1550 and 1552 both intersect the closed shape 1126, thereby dividing the closed shape 1126 into portions 1126A, 1126B, and 1126C. In this particular case, closed shape portion 1126B lies outside the minimum tilt target boundary represented by line 1550, closed shape portion 1126C lies outside the maximum tilt target boundary represented by line 1552, and closed shape portion 1126A lies inside both the minimum tilt target boundary represented by line 1550 and the maximum tilt target boundary represented by line 1552. As mentioned above, the shape and positioning of lines 1550 and 1552 depend on the patient-specific pelvic tilt measurements and will therefore vary depending on the specific circumstances. Therefore, whether a given line representing the target boundary intersects with a closed shape representing a set of target orientations of the acetabular cup 104 (and if so, with which part) will vary depending on the patient’s pelvic mobility and the size and shape of each patient target area output by the box 1002 of method 1000.

[0126] In some implementations, each portion of the closed shape 1126 located outside any of the target boundaries of one or more target boundaries is visually different from each portion of the closed shape located inside all the target boundaries of one or more target boundaries. For example, in Figure 15BIn the illustrative graphic 1120B shown, closed shape portion 1126B (which is outside the minimum tilt target boundary represented by line 1550) and closed shape portion 1126C (which is outside the maximum tilt target boundary represented by line 1552) are each colored yellow. Conversely, closed shape portion 1126A (which is inside both the minimum tilt target boundary represented by line 1550 and the maximum tilt target boundary represented by line 1552) is colored green. In other embodiments, different shading, shading lines, patterns, and / or labels can be used to provide visual distinction between different portions of the closed shape 1126 that have different relationships with one or more target boundaries. In some scenarios, it may be possible that no portion of the closed shape 1126 is located within the target boundary (i.e., no candidate orientation meets all selection criteria, including any applicable boundaries). In such cases, systems 400, 500 can select which graphic elements to display or not display based on one or more user-defined preferences.

[0127] In other alternative implementations, one or more target boundaries may be used to remove certain target orientations of the acetabular cup 104 output by box 1002 of method 1000 before the patient target area is displayed to the user. For example, in Figure 15C Alternative graphics 1120C and Figure 15D In alternative drawing 1120D, certain target orientations of the acetabular cup 104 have been removed from the patient target area. These target orientations were predicted not to cause rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup (in box 1002), but did not satisfy the two target boundaries represented by lines 1550 and 1552. Specifically, the target orientation below the minimum tilt target boundary represented by line 1550 (i.e., Figure 15A and Figure 15B The closed shape portion 1126B in the middle has been removed, and the target orientation above the maximum tilt target boundary represented by line 1552 (i.e., Figure 15A and Figure 15B The closed shape portion (1126C) has also been removed.

[0128] Because target orientations that do not satisfy one or more target boundaries have been removed, the closed shape 1526 included in figures 1120C and 1120D differs from the closed shape 1126 included in figures 1120A and 1120B. The modified closed shape 1526 (which differs from the one from...) Figure 15A and Figure 15BThe closed shape portion 1126A (matched) represents the target orientation, which is both (i) predicted not to cause rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup (in box 1002), and (ii) satisfies all included target boundaries. In this way, one or more target boundaries can be used as an additional filter for which the orientation of the acetabular cup 104 is included in the patient target area. In such embodiments, the marking indicating the centroid of the closed shape can also be modified. For example, in Figure 15C and Figure 15D In the diagram, marker 1528 indicates the new centroid of the modified closed shape 1526. It is also envisioned that, in cases where the patient target area has been modified to remove the acetabular cup 104 and the target orientation does not satisfy all applicable target boundaries, optional inclusion (as in...) is possible. Figure 15C (in alternative graphics 1120C) or not included (as in) Figure 15D (In the alternative graphic 1120D) the line representing the target boundary.

[0129] As described above, systems 400 and 500 can also be used to assist orthopedic surgeons in performing orthopedic surgery on a patient's hip joint to implant a hip prosthesis 100. An example of method 1600 that can be performed by an orthopedic surgeon using one of systems 400 or 500 is shown as follows. Figure 16 The flowchart in the diagram is shown. Method 1600 begins at box 1602, where a user (e.g., a plastic surgeon) operates computer system 400 to develop a surgical plan for a plastic surgery procedure. Any system and method described in this disclosure can be used to generate a surgical plan in box 1602. This surgical plan includes, in particular, a planned tilt of the femoral prosthesis 102 of the hip prosthesis 100 to be implanted (e.g., selected by the user), and a set of target orientations of the acetabular cup 104 of the hip prosthesis 100 to be implanted (e.g., in…). Figure 10A The planning tilt generation for the femoral prosthesis 102 in box 1002), and the planning orientation of the acetabular cup 104 (e.g., using...). Figures 11 to 15D The graphical user interface allows selection from a set of target orientations. Box 1602 can be performed preoperatively and / or intraoperatively. For example, in some implementations, surgical planning may be developed before surgery but subsequently revised or reformulated during the operation.

[0130] After at least an initial tilt of the surgical plan developed in box 1602, method 1600 proceeds to box 1604, where the orthopedic surgeon prepares the patient's hip joint using the surgical plan. Certain aspects of the surgical plan (such as the size and type of the hip prosthesis 100 selected by the surgeon, the planned tilt of the femoral prosthesis 102, and / or the planned orientation of the acetabular cup 104) may specify other aspects of the surgical plan (such as the bone portions to be removed in order to surgically prepare the hip joint to receive the hip prosthesis 100). In an exemplary embodiment, box 1604 relates to a surgical tracking system 408 of computer system 400 assisting the orthopedic surgeon in preparing the hip joint according to the surgical plan developed in box 1602. For example, the surgical tracking system 408 may instruct the surgeon whether the tracked surgical instruments are correctly positioned relative to the patient's bone anatomy to accurately perform surgical steps according to the surgical plan.

[0131] After the patient's hip joint has been surgically prepared in frame 1604, method 1600 proceeds to frame 1606, where an orthopedic surgeon positions the acetabular cup 104 within the patient's acetabulum 200. The acetabular cup 104 positioned by the surgeon in frame 1606 can be a trial component (designed to test fit of the size and type of the acetabular cup 104, but not implanted) or a final component (designed to be implanted, but not yet glued or otherwise permanently installed). In either case, after the acetabular cup 104 has been positioned in frame 1606, method 1600 proceeds to frame 1608, where computer system 400 detects the actual orientation of the positioned acetabular cup 104 relative to the patient's acetabulum 200. In an exemplary embodiment, method 1600 involves attaching markers to both the acetabular cup 104 and the patient's pelvis (prior to frame 1608) such that the relative position and orientation of those structures can be tracked by surgical tracking system 408 in frame 1608.

[0132] After the actual orientation of the acetabular cup 104 has been detected in box 1608, method 1600 proceeds to box 1610, where computer system 400 presents a comparison of the actual orientation of the acetabular cup 104 detected in box 1608 with a set of target orientations of the acetabular cup 104 from the surgical plan formulated in box 1602. It is envisioned that this comparison may be presented in textual and / or graphical form. For example, in some embodiments, computer system 400 may present binary information to an orthopedic surgeon indicating whether the actual orientation of the acetabular cup 104 detected in box 1608 is part of a set of target orientations of the acetabular cup 104 from the surgical plan. In other embodiments, box 1610 may relate to box 1612, where the computer system displays a graphic including both a closed shape and markings (e.g., crosshairs) representing a set of target orientations of the acetabular cup 104 (e.g., similar to...). Figures 11 to 13 and Figures 15A to 15D The notation (either of figures 1120 and 1320 in the diagram) indicates the actual orientation of the acetabular cup 104 detected in box 1608 when drawn relative to a set of tilt and rotation axes that are the same as the target orientation of the acetabular cup 104. It should be understood that the figures displayed in box 1612 may include additional information, including any of the information described above (e.g., optimal orientation of the acetabular cup 104, planned orientation of the acetabular cup 104, etc.). In any case, the orthopedic surgeon may use the information presented in box 1610 to perform orthopedic surgery (e.g., with the current size, type, and orientation of the acetabular cup 104, or to change it to another size, type, and / or orientation of the acetabular cup 104 before proceeding).

[0133] Although the present disclosure has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions should be regarded as exemplary rather than restrictive in nature, and it should be understood that only exemplary embodiments are shown and described, and all changes and modifications made within the substance of the present disclosure should be protected.

[0134] The methods, apparatus, and systems described herein possess numerous advantages due to their various features. It should be noted that alternative embodiments of the methods, apparatus, and systems of this disclosure may exclude all described features, but may still benefit from at least some of the advantages of such features. Those skilled in the art will readily conceive of their own implementations of the methods, apparatus, and systems described above, which may incorporate one or more features of the invention and fall within the spirit and scope of this disclosure as defined by the appended claims.

Claims

1. A method for planning orthopedic surgery on a patient's hip to implant a hip prosthesis having a femoral prosthesis and an acetabular cup, the method comprising: A computer system is used to determine a first set of target orientations for the acetabular cup when the femoral prosthesis is in a first tilt orientation. The computer system is used to determine a second set of target orientations for the acetabular cup when the femoral prosthesis is in a second tilt orientation different from the first tilt. The computer system displays a first graphical user interface (GUI), the first graphical user interface (GUI) comprising: (i) a first graphic representing a first set of target orientations of the acetabular cup; (ii) a first interface element indicating that the first graphic corresponds to the femoral prosthesis with the first tilt orientation; and (iii) a second interface element indicating that a second set of target orientations of the acetabular cup corresponding to the femoral prosthesis with the second tilt orientation is available for viewing; The computer system receives user input associated with the second interface element; and The computer system is used to display a second GUI in response to receiving user input associated with the second interface element. The second GUI includes: (i) a second graphic representing the second set of target orientations of the acetabular cup; (ii) a third interface element indicating that the second graphic corresponds to the femoral prosthesis with the second tilt orientation; and (iii) a fourth interface element indicating that the first set of target orientations of the acetabular cup corresponding to the femoral prosthesis with the first tilt orientation is available for viewing.

2. The method according to claim 1, wherein, Displaying the second GUI includes updating the first GUI by: (i) replacing the first graphic with the second graphic, (ii) replacing the first interface element with the fourth interface element, and (iii) replacing the second interface element with the third interface element.

3. The method according to claim 1 or claim 2, wherein, The computer system determines the second set of target orientations of the acetabular cup before receiving the user input associated with the second interface element of the first GUI.

4. The method according to any one of claims 1 to 3, wherein, The first tilt is 15 degrees, and the second tilt is selected from the group consisting of -5 degrees, 5 degrees, 25 degrees and 35 degrees.

5. The method according to any one of claims 1 to 3, wherein, Determining the first set of target orientations of the acetabular cup when the femoral prosthesis is in the first tilt orientation includes: determining the target orientation of the acetabular cup when the femoral prosthesis is in the same tilt orientation as the patient's natural femur.

6. The method according to any one of claims 1 to 5, further comprising: The computer system is used to receive user input associated with the fourth interface element; as well as In response to receiving the user input associated with the fourth interface element, the computer system displays the first GUI.

7. The method according to any one of claims 1 to 6, further comprising: The computer system is used to determine a third set of target orientations for the acetabular cup when the femoral prosthesis is oriented at a third tilt, different from the first and second tilts. The computer system receives user input associated with a fifth interface element included in both the first GUI and the second GUI, the fifth interface element indicating that the third set of target orientations of the acetabular cup corresponding to the femoral prosthesis with the third tilt orientation is available for viewing; as well as The computer system is used to display a third GUI in response to receiving user input associated with the fifth interface element. The third GUI includes: (i) a third graphic representing the third set of target orientations of the acetabular cup; (ii) a sixth interface element indicating that the third graphic corresponds to the femoral prosthesis with the third tilt orientation; (iii) a fourth interface element indicating that the first set of target orientations of the acetabular cup corresponding to the femoral prosthesis with the first tilt orientation is available for viewing; and (iv) a second interface element indicating that the second set of target orientations of the acetabular cup corresponding to the femoral prosthesis with the second tilt orientation is available for viewing.

8. The method according to any one of claims 1 to 6, wherein: The method further includes using the computer system to determine that the number of target orientations of the acetabular cup is below an output threshold when the femoral prosthesis is in a third tilt orientation, wherein the third tilt is different from the first tilt and the second tilt; The first GUI also includes a fifth interface element, which indicates that when the femoral prosthesis is in the third tilt orientation, the computer system cannot generate a sufficient set of target orientations for the acetabular cup; and The second GUI also includes the fifth interface element.

9. The method according to any one of claims 1 to 8, wherein: The first graphic includes a tilt axis, a rotation axis, and a first closed shape, the first closed shape being drawn relative to the tilt axis and the rotation axis around the first set of target orientations of the acetabular cup; and The second graphic includes the tilt axis, the slewing axis, and a second closed shape, the second closed shape being drawn relative to the tilt axis and the slewing axis around the second set of target orientations of the acetabular cup.

10. The method according to claim 9, wherein: The first graphic also includes a marker indicating the centroid of the first closed shape; and The second graphic also includes a mark indicating the centroid of the second closed shape.

11. The method according to claim 9 or claim 10, wherein: The first graphic also includes a first line, which, when drawn relative to the tilt axis and the rotation axis, represents a first target boundary; and The second figure also includes the first line.

12. The method according to claim 11, wherein, The first line intersects at least one of the following: (i) the first closed shape in the first figure, and (ii) the second closed shape in the second figure.

13. The method according to claim 12, wherein, The portions of the first closed shape and the second closed shape located inside the first target boundary are visually different from the portions of the first closed shape and the second closed shape located outside the first target boundary.

14. The method according to any one of claims 11 to 13, wherein, The first line is positioned in each of the first and second graphs based on patient-specific pelvic tilt measurements.

15. The method according to claim 14, wherein, The first line is curved to reflect the nonlinear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation.

16. The method of claim 14, wherein, The first line is straight, but approximates the relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation.

17. The method according to any one of claims 11 to 16, wherein, The first target boundary is based on the minimum or maximum allowable tilt of the acetabular cup in the patient's specific functional position.

18. The method according to claim 17, wherein, The minimum or maximum permissible tilt of the acetabular cup in the patient's specific functional position is user-defined.

19. The method of claim 17, wherein, The minimum or maximum permissible tilt of the acetabular cup in the patient’s specific functional position is predefined using values ​​taken from medical literature.

20. The method according to any one of claims 11 to 16, wherein: The first graphic also includes a second line, which, when drawn relative to the tilt axis and the rotation axis, represents the boundary of the second target; and The second graphic also includes the second line.

21. The method according to claim 20, wherein, The second line intersects at least one of the following: (i) the first closed shape in the first figure, and (ii) the second closed shape in the second figure.

22. The method according to claim 21, wherein, The portions of the first closed shape and the second closed shape located inside both the first target boundary and the second target boundary are visually different from the portions of the first closed shape and the second closed shape located outside either the first target boundary or the second target boundary.

23. The method according to any one of claims 20 to 22, wherein, The second line is positioned in each of the first and second graphs based on patient-specific pelvic tilt measurements.

24. The method according to any one of claims 20 to 23, wherein: The first target boundary is based on the minimum permissible tilt of the acetabular cup in the patient's first functional position; and The second target boundary is based on the maximum permissible tilt of the acetabular cup in the patient's second functional position, which is different from the first functional position.

25. The method of claim 24, wherein: When the first functional position is the flexed seated position, the minimum permissible tilt of the acetabular cup is 10 degrees; and When the second functional position is the standing position, the maximum permissible tilt of the acetabular cup is 30 degrees.

26. The method according to any one of claims 1 to 25, wherein: Determining the first set of target orientations for the acetabular cup includes: predicting a set of orientations for the acetabular cup such that, when the femoral prosthesis is in the first tilt orientation, the set of orientations will not result in rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup; and Determining the second set of target orientations for the acetabular cup includes predicting a set of orientations for the acetabular cup that, when the femoral prosthesis is in the second tilt orientation, will not result in the femoral prosthesis loading the edge of the acetabular cup or impingement between the femoral prosthesis and the acetabular cup.

27. The method according to claim 26, wherein, A set of orientations that predict will not result in rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup when the femoral prosthesis is oriented at the first or second tilt include: The first mathematical model is operated, wherein a set of candidate orientations of the acetabular cup, patient-specific pelvic tilt measurements, and type and size data of the hip prosthesis are used as inputs to generate a predicted distance between the following items for each candidate orientation of the acetabular cup: (i) the edge of the cup liner of the acetabular cup and (ii) the contact position between the cup liner and the femoral head of the femoral prosthesis in each of the multiple different functional positions of the patient. Select the candidate orientation of the acetabular cup such that each of the predicted distances is greater than a distance threshold; A second mathematical model is operated, wherein the selected candidate orientation of the acetabular cup, the patient-specific pelvic tilt measurement, the type and size data of the hip prosthesis, and the corresponding tilt of the femoral prosthesis are used as inputs to generate a predicted femoral prosthesis rotation for each selected candidate orientation of the acetabular cup, until the femoral prosthesis and the acetabular cup impinge in each of the multiple different functional positions of the patient; and The selected candidate orientations of the acetabular cup that cause each of the predicted femoral prosthesis rotations to be greater than a rotation threshold are identified as the set of orientations of the acetabular cup that are predicted to not cause the femoral prosthesis to cause edge loading on the acetabular cup or impact between the femoral prosthesis and the acetabular cup when the femoral prosthesis is in the corresponding tilt orientation.

28. The method according to claim 27, wherein, The selected candidate orientations that identify the acetabular cup such that each of the predicted femoral prosthesis rotation amounts is greater than a rotation threshold include: Determine a first number of selected candidate orientations for the acetabular cup that cause each of the predicted femoral prosthesis rotations to be greater than a first rotation threshold; and In response to a first number being less than a size threshold of the set of target orientations of the acetabular cup, a second number of selected candidate orientations of the acetabular cup are determined such that each of the predicted femoral prosthesis rotations is greater than a second rotation threshold, wherein the second rotation threshold is less than the first rotation threshold.

29. The method according to any one of claims 26 to 28, wherein: Determining the first set of target orientations for the acetabular cup further includes: removing orientations of the acetabular cup that do not satisfy one or more target boundaries from the set of orientations of the acetabular cup that are predicted not to cause rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup when the femoral prosthesis is in the first tilt orientation, such that the orientations of the acetabular cup that do not satisfy the one or more target boundaries are not included in the first set of target orientations of the acetabular cup; and Determining the second set of target orientations for the acetabular cup further includes removing orientations of the acetabular cup that do not satisfy the one or more target boundaries from the set of orientations of the acetabular cup that are predicted not to cause rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup when the femoral prosthesis is in the second tilt orientation, such that the orientations of the acetabular cup that do not satisfy the one or more target boundaries are not included in the second set of target orientations for the acetabular cup.

30. The method according to claim 29, wherein, Each of the one or more target boundaries is based on the corresponding minimum or maximum permissible tilt of the acetabular cup in the corresponding functional position of the patient, the corresponding minimum or maximum permissible tilt being converted into a reference frame for the first set of target orientations and the second set of target orientations of the acetabular cup using patient-specific pelvic tilt measurements.

31. The method according to claim 30, wherein, The one or more target boundaries include: A first target boundary, the first target boundary being based on the minimum permissible tilt of the acetabular cup in the patient's first functional position; and The second target boundary is based on the maximum permissible tilt of the acetabular cup in a second functional position of the patient, different from the first functional position.

32. The method according to claim 31, wherein: The first target boundary requires that the acetabular cup has at least 10 degrees of tilt when the patient is in a flexed seated position; and The second target boundary requires that the acetabular cup have a tilt of no more than 30 degrees when the patient is in a standing position.

33. The method according to any one of claims 29 to 32, wherein, The one or more target boundaries each reflect the nonlinear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation.

34. A method for planning orthopedic surgery on a patient's hip to implant a hip prosthesis having a femoral prosthesis and an acetabular cup, the method comprising: A computer system is used to predict a set of target orientations for the acetabular cup, which will not cause the femoral prosthesis to load the edge of the acetabular cup or to impinge the femoral prosthesis with the acetabular cup; The computer system uses patient-specific pelvic tilt measurements to convert the minimum or maximum permissible tilt of the acetabular cup in the patient's functional position into a reference frame for the set of target orientations of the acetabular cup to determine the target boundaries. as well as The computer system displays graphics including a tilt axis, a slew axis, a closed shape of the set of target orientations around the acetabular cup when drawn relative to the tilt axis and the slew axis, and lines representing the target boundaries when drawn relative to the tilt axis and the slew axis.

35. The method according to claim 34, wherein, The line intersects the closed shape in the graphic, and the portion of the closed shape located inside the target boundary is visually different from the portion of the closed shape located outside the target boundary.

36. The method according to claim 34 or claim 35, wherein, The line is curved to reflect the nonlinear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation.

37. A method for planning orthopedic surgery on a patient's hip to implant a hip prosthesis having a femoral prosthesis and an acetabular cup, the method comprising: A computer system is used to predict a set of target orientations for the acetabular cup, which will not cause the femoral prosthesis to load the edge of the acetabular cup or to impinge the femoral prosthesis with the acetabular cup; The computer system uses patient-specific pelvic tilt measurements to convert the minimum permissible tilt of the acetabular cup in the patient's first functional position into a reference frame for the set of target orientations of the acetabular cup to determine the first target boundary. The computer system uses the patient-specific pelvic tilt measurement results to convert the maximum permissible tilt of the acetabular cup in the patient's second functional position into the reference frame of the set of target orientations of the acetabular cup to determine the second target boundary; as well as The computer system displays graphics including a tilt axis, a slew axis, a closed shape of the set of target orientations around the acetabular cup when drawn relative to the tilt axis and the slew axis, a first line representing the boundary of the first target when drawn relative to the tilt axis and the slew axis, and a second line representing the boundary of the first target when drawn relative to the tilt axis and the slew axis.

38. The method of claim 37, wherein: At least one of the first line and the second line intersects the closed shape in the figure; and The portion of the closed shape located inside both the first target boundary and the second target boundary is visually different from each portion of the closed shape located outside either the first target boundary or the second target boundary.

39. The method according to claim 37 or claim 38, wherein, The first and second lines are each curved to reflect the nonlinear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation.

40. The method according to any one of claims 37 to 39, wherein: The first target boundary reflects a minimum permissible tilt of 10 degrees for the acetabular cup when the first functional position is a flexed seated position; and The second target boundary reflects the maximum permissible tilt of the acetabular cup at 30 degrees when the second functional position is a standing position.

41. The method according to any one of claims 34 to 40, wherein, The set of target orientations that predict the acetabular cup will not result in rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup include: The first mathematical model is operated, wherein a set of candidate orientations of the acetabular cup, patient-specific pelvic tilt measurements, and type and size data of the hip prosthesis are used as inputs to generate a predicted distance between the following items for each candidate orientation of the acetabular cup: (i) the edge of the cup liner of the acetabular cup and (ii) the contact position between the cup liner and the femoral head of the femoral prosthesis in each of the multiple different functional positions of the patient. Select the candidate orientation of the acetabular cup such that each of the predicted distances is greater than a distance threshold; A second mathematical model is operated, wherein the selected candidate orientation of the acetabular cup, the patient-specific pelvic tilt measurements, the type and size data of the hip prosthesis, and the planned tilt of the femoral prosthesis are used as inputs to generate a predicted femoral prosthesis rotation for each selected candidate orientation of the acetabular cup, until the femoral prosthesis and the acetabular cup impinge in each of the multiple different functional positions of the patient; and The selected candidate orientations of the acetabular cup that cause each of the predicted femoral prosthesis rotations to be greater than a rotation threshold are identified as the set of target orientations of the acetabular cup.

42. The method of claim 41, further comprising: The computer system is used to measure the preoperative tilt of the patient's natural femur from one or more medical images, wherein the measured preoperative tilt is used as the planned tilt of the femoral prosthesis when operating the second mathematical model.

43. The method according to claim 41 or claim 42, wherein, The selected candidate orientations that identify the acetabular cup such that each of the predicted femoral prosthesis rotation amounts is greater than a rotation threshold include: Determine a first number of selected candidate orientations for the acetabular cup that cause each of the predicted femoral prosthesis rotations to be greater than a first rotation threshold; and In response to a first number being less than a size threshold of the set of target orientations of the acetabular cup, a second number of selected candidate orientations of the acetabular cup are determined such that each of the predicted femoral prosthesis rotations is greater than a second rotation threshold, wherein the second rotation threshold is less than the first rotation threshold.

44. A method for planning orthopedic surgery on a patient's hip to implant a hip prosthesis having a femoral prosthesis and an acetabular cup, the method comprising: The computer system is used to predict a first set of orientations for the acetabular cup, which will not cause the femoral prosthesis to load the edge of the acetabular cup or to impinge the femoral prosthesis with the acetabular cup. The computer system is used to determine a second set of target orientations for the acetabular cup by removing orientations from the first set of orientations that do not meet one or more target boundaries; as well as The computer system displays graphics including a tilt axis, a slew axis, and a closed shape, the closed shape being drawn relative to the tilt axis and the slew axis around the second set of orientations of the acetabular cup.

45. The method according to claim 44, wherein, The first set of orientations that predict the acetabular cup will not result in rim loading of the femoral prosthesis on the acetabular cup or impingement between the femoral prosthesis and the acetabular cup includes: The first mathematical model is operated, wherein a set of candidate orientations of the acetabular cup, patient-specific pelvic tilt measurements, and type and size data of the hip prosthesis are used as inputs to generate a predicted distance between the following items for each candidate orientation of the acetabular cup: (i) the edge of the cup liner of the acetabular cup and (ii) the contact position between the cup liner and the femoral head of the femoral prosthesis in each of the multiple different functional positions of the patient. Select the candidate orientation of the acetabular cup such that each of the predicted distances is greater than a distance threshold; A second mathematical model is operated, wherein the selected candidate orientation of the acetabular cup, the patient-specific pelvic tilt measurements, the type and size data of the hip prosthesis, and the planned tilt of the femoral prosthesis are used as inputs to generate a predicted femoral prosthesis rotation for each selected candidate orientation of the acetabular cup, until the femoral prosthesis and the acetabular cup impinge in each of the multiple different functional positions of the patient; and The selected candidate orientations of the acetabular cup that cause each of the predicted femoral prosthesis rotations to be greater than a rotation threshold are identified as the first set of orientations of the acetabular cup.

46. ​​The method of claim 45, further comprising: The computer system is used to measure the preoperative tilt of the patient's natural femur from one or more medical images, wherein the measured preoperative tilt is used as the planned tilt of the femoral prosthesis when operating the second mathematical model.

47. The method according to claim 45 or claim 46, wherein, The selected candidate orientations that identify the acetabular cup such that each of the predicted femoral prosthesis rotation amounts is greater than a rotation threshold include: Determine a first number of selected candidate orientations for the acetabular cup that cause each of the predicted femoral prosthesis rotations to be greater than a first rotation threshold; and In response to a first number being less than a size threshold of the set of target orientations of the acetabular cup, a second number of selected candidate orientations of the acetabular cup are determined such that each of the predicted femoral prosthesis rotations is greater than a second rotation threshold, wherein the second rotation threshold is less than the first rotation threshold.

48. The method according to any one of claims 44 to 47, wherein, Each of the one or more target boundaries is based on the corresponding minimum or maximum permissible tilt of the acetabular cup in the corresponding functional position of the patient, the corresponding minimum or maximum permissible tilt being converted into a reference system for the first set of orientations and the second set of orientations of the acetabular cup using patient-specific pelvic tilt measurements.

49. The method according to claim 48, wherein, The one or more target boundaries include: A first target boundary, the first target boundary being based on the minimum permissible tilt of the acetabular cup in the patient's first functional position; and The second target boundary is based on the maximum permissible tilt of the acetabular cup in a second functional position of the patient, different from the first functional position.

50. The method according to claim 49, wherein: The first target boundary requires that the acetabular cup has at least 10 degrees of tilt when the patient is in a flexed seated position; and The second target boundary requires that the acetabular cup have a tilt of no more than 30 degrees when the patient is in a standing position.

51. The method according to any one of claims 44 to 50, wherein, The one or more target boundaries each reflect the nonlinear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation.

52. The method according to any one of claims 44 to 51, wherein, When the second set of target orientations of the acetabular cup is an empty set, the drawing also includes at least one of the following: (i) a closed shape that, when drawn relative to the tilt axis and the yaw axis, surrounds the first set of orientations of the acetabular cup; and (ii) one or more lines that, when drawn relative to the tilt axis and the yaw axis, represent the one or more target boundaries, as defined by a user-defined preference.

53. The method according to any one of claims 34 to 52, wherein, The graphic also includes a marker indicating the centroid of the closed shape.

54. The method according to any one of claims 34 to 53, further comprising: The computer system receives user input indicating the planned orientation of the acetabular cup, wherein the graph also includes markers representing the planned orientation of the acetabular cup when drawn relative to the tilt axis and the rotation axis.

55. The method according to any one of claims 34 to 54, further comprising: During the orthopedic surgery, the computer system is used to detect the actual orientation of the acetabular cup relative to the patient's acetabulum, wherein the graph also includes markings indicating the actual orientation of the acetabular cup when drawn relative to the tilt axis and the rotation axis.

56. A method for planning orthopedic surgery on a patient's hip to implant a hip prosthesis having a femoral prosthesis and an acetabular cup, the method comprising: A computer system is used to operate a first mathematical model, wherein a set of candidate orientations of the acetabular cup, patient-specific pelvic tilt measurements, and type and size data of the hip prosthesis are used as inputs to the first mathematical model to generate a predicted distance between (i) the edge of the cup liner of the acetabular cup and (ii) the contact position between the cup liner and the femoral head of the femoral prosthesis in each of the multiple different functional positions of the patient. The computer system is used to select the candidate orientations of the acetabular cup such that each of the predicted distances is greater than a distance threshold. The computer system operates a second mathematical model, wherein the selected candidate orientation of the acetabular cup, the patient-specific pelvic tilt measurement, the type and size data of the hip prosthesis, and the planned tilt of the femoral prosthesis are used as inputs to the second mathematical model to generate a predicted amount of femoral prosthesis rotation for each selected candidate orientation of the acetabular cup until the femoral prosthesis and the acetabular cup impinge in each of the multiple different functional positions of the patient; The computer system identifies selected candidate orientations of the acetabular cup that cause each of the predicted femoral prosthesis rotations to be greater than a rotation threshold as a set of target orientations of the acetabular cup that are predicted to not cause the femoral prosthesis to cause edge loading on the acetabular cup or impact between the femoral prosthesis and the acetabular cup when the femoral prosthesis is in the planned tilt orientation. as well as The computer system provides a user interface that presents the set of target orientations of the acetabular cup to the orthopedic surgeon.

57. The method of claim 56, further comprising: The computer system is used to measure the preoperative tilt of the patient's natural femur from one or more medical images, wherein the measured preoperative tilt is used as the planned tilt of the femoral prosthesis when operating the second mathematical model.

58. The method according to claim 56 or claim 57, wherein, The selected candidate orientations that identify the acetabular cup such that each of the predicted femoral prosthesis rotation amounts is greater than a rotation threshold include: Determine a first number of selected candidate orientations for the acetabular cup that cause each of the predicted femoral prosthesis rotations to be greater than a first rotation threshold; and In response to a first number being less than a size threshold of the set of target orientations of the acetabular cup, a second number of selected candidate orientations of the acetabular cup are determined such that each of the predicted femoral prosthesis rotations is greater than a second rotation threshold, wherein the second rotation threshold is less than the first rotation threshold.

59. The method according to any one of claims 56 to 58, wherein, The user interface includes graphics that include a tilt axis, a slew axis, and a closed shape that, when drawn relative to the tilt axis and the slew axis, is oriented around the set of target orientations of the acetabular cup.

60. The method according to claim 59, wherein, The graphic also includes a marker indicating the centroid of the closed shape.

61. The method according to claim 59 or claim 60, further comprising: The user interface receives input indicating the planning orientation of the acetabular cup selected by the orthopedic surgeon, wherein the graph also includes markers representing the planning orientation of the acetabular cup when drawn relative to the tilt axis and the rotation axis.

62. The method according to any one of claims 59 to 61, further comprising: During the orthopedic surgery, the computer system is used to detect the actual orientation of the acetabular cup relative to the patient's acetabulum, wherein the graph also includes markings indicating the actual orientation of the acetabular cup when drawn relative to the tilt axis and the rotation axis.

63. The method according to any one of claims 56 to 58, further comprising: During the orthopedic surgery, the computer system is used to detect the actual orientation of the acetabular cup relative to the patient's acetabulum; as well as During the orthopedic surgery, a comparison is presented via the user interface between the actual orientation of the acetabular cup and the set of target orientations of the acetabular cup.

64. The method according to claim 63, wherein, The user interface includes graphics that include a tilt axis, a slew axis, a closed shape around the set of target orientations of the acetabular cup when drawn relative to the tilt axis and the slew axis, and a marker representing the actual orientation of the acetabular cup when drawn relative to the tilt axis and the slew axis.

65. The method according to claim 59 or claim 64, wherein, The graph also includes a first line, which, when drawn relative to the tilt axis and the rotation axis, represents a first target boundary.

66. The method according to claim 65, wherein, The first line is positioned in the graph based on patient-specific pelvic tilt measurements.

67. The method according to claim 66, wherein, The first line is curved to reflect the nonlinear relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation.

68. The method according to claim 66, wherein, The first line is straight, but approximates the relationship between pelvic tilt, acetabular cup tilt, and acetabular cup rotation.

69. The method according to any one of claims 65 to 68, wherein, The first target boundary is based on the minimum or maximum allowable tilt of the acetabular cup in the patient's specific functional position.

70. The method according to claim 69, wherein, The minimum or maximum permissible tilt of the acetabular cup in the patient's specific functional position is user-defined.

71. The method according to claim 69, wherein, The minimum or maximum permissible tilt of the acetabular cup in the patient’s specific functional position is predefined using values ​​taken from medical literature.

72. The method according to any one of claims 65 to 68, wherein, The graph also includes a second line, which, when drawn relative to the tilt axis and the rotation axis, represents the boundary of the second target.

73. The method according to claim 72, wherein, The portion of the closed shape located inside both the first target boundary and the second target boundary is visually different from the portion of the closed shape located outside either the first target boundary or the second target boundary.

74. The method according to claim 72 or claim 73, wherein: The first target boundary is based on the minimum permissible tilt of the acetabular cup in the patient's first functional position; and The second target boundary is based on the maximum permissible tilt of the acetabular cup in the patient's second functional position, which is different from the first functional position.

75. The method according to claim 74, wherein: When the first functional position is the flexed seated position, the minimum permissible tilt of the acetabular cup is 10 degrees; and When the second functional position is the standing position, the maximum permissible tilt of the acetabular cup is 30 degrees.

76. A method for planning orthopedic surgery involving a patient's pelvis, the method comprising: A standing medical image is acquired by a computer system, the standing medical image showing the sagittal contour of the patient's pelvis in a standing position; The computer system acquires seated medical images showing the sagittal contour of the patient's pelvis in a seated position. The computer system is used to determine the standing sacral slope value from the standing medical image; The computer system is used to determine the sacral slope value from the seated medical image; The computer system is used to calculate the pelvic mobility value as the difference between the standing sacral slope value and the seated sacral slope value; as well as In response to the calculated pelvic mobility value being outside a predetermined range, the computer system generates a user alert.

77. The method according to claim 76, wherein, Generating the user alert includes: in response to a calculated pelvic mobility value being less than the lower end of the predetermined range, displaying a message on the computer system indicating that the patient has a stiff spine.

78. The method according to claim 77, wherein, Each of the standing sacral inclination value, the seated sacral inclination value, and the pelvic mobility value is an angle expressed in degrees, and wherein the lower end of the predetermined range is 10 degrees.

79. The method according to any one of claims 76 to 78, wherein, Generating the user alert includes: in response to a calculated pelvic mobility value being greater than the upper end of the predetermined range, displaying a message on the computer system indicating that the patient has hypermobility of the spine.

80. The method according to claim 79, wherein, Each of the standing sacral inclination value, the seated sacral inclination value, and the pelvic mobility value is an angle expressed in degrees, and wherein the upper end of the predetermined range is 35 degrees.

81. The method according to any one of claims 76 to 80, wherein: Determining the standing sacral slope value from the standing medical image includes: Receive one or more user inputs, the one or more user inputs positioning a standing reference line across the upper edge of the S1 endplate of the patient as shown in the standing medical image; and The standing sacral slope value is calculated as the arctangent of the slope of the standing reference line located by the user; and Determining the sacral slope value from the seated medical image includes: Receive one or more user inputs, the one or more user inputs positioning the seating reference line across the upper edge of the S1 endplate of the patient as shown in the seated medical image; and The sacral slope value of the seated position is calculated as the arctangent of the slope of the seated reference line located by the user.

82. A method for planning orthopedic surgery involving a patient's pelvis, the method comprising: A standing medical image is acquired by a computer system, the standing medical image showing the sagittal contour of the patient's pelvis in a standing position; The computer system is used to determine the sacral slope value, the midpoint of the sacral slope, and the center of the femoral head from the standing medical image. The computer system is used to calculate the spinopelvic tilt value using the midpoint of the sacral slope and the center of the femoral head. The computer system is used to calculate the pelvic incident angle value as the sum of the sacral slope value and the spinal pelvic tilt value. as well as In response to the calculated pelvic incidence angle value being outside a predetermined range, the computer system generates a user alert.

83. The method according to claim 82, wherein, Each of the sacral slope value, the spinopelvic tilt value, and the pelvic incident angle value is an angle expressed in degrees, and the predetermined range is 45 degrees to 65 degrees.

84. The method according to claim 82 or claim 83, wherein, Generating the user alert includes displaying a message on the computer system suggesting that the surgeon assess the patient's risk of bone-on-bone impact during surgery.

85. The method according to claim 84, wherein, The message is displayed on the computer system during the plastic surgery procedure.

86. The method according to any one of claims 82 to 85, wherein, Determining the sacral slope value and the midpoint of the sacral slope from the standing medical image includes: Receive one or more user inputs, the one or more user inputs positioning the reference line across the upper edge of the S1 endplate of the patient as shown in the standing medical image; The sacral slope value is calculated as the arctangent of the slope of the reference line located by the user; and The midpoint of the sacral slope is calculated as the midpoint of the reference line located by the user.

87. The method according to claim 86, wherein, Calculating the spinopelvic tilt value using the midpoint of the sacral slope and the center of the femoral head includes: calculating the arctangent of the slope of the derived line defined by the midpoint of the sacral slope and the center of the femoral head.

88. The method according to claim 86 or claim 87, wherein, Determining the center of the femoral head from the standing medical image includes: Receive one or more user inputs, the one or more user inputs positioning a reference circle around the femoral head of the patient as shown in the standing medical image; and The center of the reference circle located by the user is recorded as the center of the femoral head.

89. The method according to claim 86 or claim 87, wherein, Determining the center of the femoral head from the standing medical image includes: Receive one or more user inputs, the one or more user inputs being positioned as: (i) a first reference circle, the first reference circle being around the first femoral head of the patient as shown in the standing medical image, and (ii) a second reference circle, the second reference circle being around the second femoral head of the patient as shown in the standing medical image; Determine the midpoint of the femoral head between: (i) the center of the first reference circle located by the user and (ii) the center of the second reference circle located by the user; and The midpoint of the femoral head is recorded as the center of the femoral head.

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