Tibial prosthesis preoperative planning method and device, electronic equipment and storage medium

Abstract

The invention provides a tibial prosthesis preoperative planning method and device, electronic equipment and a storage medium, a tibial condyle region point set is obtained by combining an operative side condyle region point set and a normal condyle region point set, a tibial coordinate system is constructed according to the tibial condyle region point set, a final reference point of a prosthesis posture is calculated in the tibial coordinate system, and the final reference point of the prosthesis posture is calculated according to the final reference point. The method comprises the following steps: acquiring a final reference point of a prosthesis posture, calculating the size of an operation-side condyle prosthesis region according to the final reference point of the prosthesis posture, and matching an optimal prosthesis body size and an optimal mounting posture according to the size of the operation-side condyle prosthesis region, so that feature information of a normal condyle is effectively utilized to assist in modeling, a more reasonable tibia coordinate system is constructed, and the accuracy of the model is improved. And the accuracy of prosthesis type matching and prosthesis posture planning is improved.

Description

Technical Field

[0001] The present invention relates to the field of medical image processing, and particularly relates to a method and device for preoperative planning of tibial prosthesis, an electronic device, and a storage medium. Background Art

[0002] Unicompartmental knee arthroplasty refers to the surface replacement of only the medial or lateral condyle of the knee joint, retaining the anterior and posterior cruciate ligaments of the knee joint, and having the characteristics of precise treatment. At present, doctors cannot achieve ideal surgical effects only driven by their own experience, and need to combine effective preoperative prosthesis planning to ensure the accuracy of the surgery, thereby reducing the incidence of postoperative complications (such as joint pain caused by unbalanced stress on the medial and lateral condyles, prosthesis dislocation caused by inaccurate tibial plateau, etc.). For the preoperative planning of tibial prosthesis, constructing a reasonable tibial coordinate system, automatically planning the accurate pose of the prosthesis, and screening the best prosthesis model are the key factors to ensure the effectiveness of tibial preoperative planning.

[0003] In the prior art, a preoperative planning system for unicompartmental arthroplasty based on deep learning is proposed. The three-dimensional femoral image and tibial image are segmented through a neural network model, and the key points and key axes in the three-dimensional bone image are identified. Then, the size and angle parameters are calculated according to the extracted key points and key axes, so as to match a suitable model in the prosthesis database. However, this system only calculates the prosthesis pose based on the key points and key axes of the tibial operative condyle, lacks the use of information of the normal tibial condyle for overall modeling, does not establish a reasonable tibial coordinate system, resulting in a too simple screening mechanism and not considering whether the lower side of the prosthesis implanted in the tibia leaks out of the tibial edge.

[0004] In the prior art, a prosthesis planning system is also proposed. The bony landmark points are automatically identified and marked, then the tibial coordinate system is constructed. Secondly, the prosthesis feature points are marked on the tibial prosthesis, and the prosthesis pose and specifications are calculated according to the bony landmark points and prosthesis feature points. However, this system overly relies on bony landmark points, lacks the use of information of the normal tibial condyle for overall modeling, and uses the 1 / 2 point of the tibial crest as a prior point to calculate the distance between the tibial outer diameter point in the prosthesis planning module, lacking adaptability, with a too simple screening mechanism and not considering whether the lower side of the prosthesis implanted in the tibia leaks out of the tibial edge.

[0005] Generally speaking, the preoperative planning system for tibial prosthesis in the prior art lacks the introduction of information of the normal tibial condyle for overall modeling, and the accuracy of prosthesis pose planning is low. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above technical deficiencies and provide a method and device for preoperative planning of tibial prosthesis, an electronic device, and a storage medium, so as to solve the problem of lack of overall modeling by introducing information of the normal tibial condyle in the related art.

[0007] To achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] According to the first aspect of the present invention, there is provided a method for preoperative planning of a tibial prosthesis. The tibial condyle includes the operative condyle and the normal condyle. The method for preoperative planning of the tibial prosthesis includes:

[0009] Obtain the point set of the operative condyle region and the point set of the normal condyle region of the tibia;

[0010] Merge the point set of the operative condyle region and the point set of the normal condyle region to obtain the point set of the tibial condyle region, and construct a tibial coordinate system according to the point set of the tibial condyle region;

[0011] In the tibial coordinate system, calculate the final reference point of the prosthesis pose, and calculate the size of the operative condyle prosthesis region according to the final reference point of the prosthesis pose;

[0012] Match the alternative prosthesis models according to the size of the operative condyle prosthesis region, and obtain the installation pose of each alternative prosthesis model according to the alternative prosthesis model and the final reference point of the prosthesis pose;

[0013] Obtain the optimal prosthesis model according to the installation pose of each alternative prosthesis model, and use the installation pose corresponding to the optimal prosthesis model as the optimal installation pose.

[0014] Preferably, the method for obtaining the point set of the operative condyle region and the point set of the normal condyle region of the tibia includes:

[0015] Obtain the point set of the contour feature points of the operative condyle and the point set of the contour feature points of the normal condyle of the tibia;

[0016] Segment the operative condyle region according to the point set of the contour feature points of the operative condyle to obtain the point set of the operative condyle region, segment the normal condyle region according to the point set of the contour feature points of the normal condyle to obtain the point set of the normal condyle region. The method for constructing the tibial coordinate system according to the point set of the tibial condyle region includes:

[0017] Fit the point set of the tibial condyle region by a plane fitting algorithm to obtain the X-axis, Y-axis and Z-axis of the tibial coordinate system;

[0018] Calculate the average point of the point set of the tibial condyle region, and use the average point as the origin of the tibial coordinate system.

[0019] Preferably, the method for calculating the final reference point of the prosthesis pose includes:

[0020] Fit an ellipse of the tibial plateau according to the point set of the operative condyle region and the point set of the normal condyle region;

[0021] Calculate the center of the ellipse of the tibial plateau and the focus of the operative condyle of the ellipse of the tibial plateau;

[0022] Calculate the initial reference point of the prosthesis pose based on the center of the ellipse of the tibial plateau and the focus of the operative condyle;

[0023] Adjust the position of the initial reference point of the prosthesis pose to obtain the final reference point of the prosthesis pose.

[0024] Preferably, the method for calculating the initial reference point of the prosthesis pose based on the center of the ellipse of the tibial plateau and the focus of the operative condyle includes:

[0025] Calculate the direction vector F from the focus of the operative condyle to the center of the ellipse of the tibial plateau;

[0026] According to the point set of the operative condyle region, fit the ellipse of the operative condyle and calculate the direction vector P from the focus of the operative condyle to each point on the ellipse of the operative condyle i , where i is the identification number of the point on the ellipse of the operative condyle, i≥0 and is an integer;

[0027] Calculate the direction vector P i The projection of to the direction vector F, and set the point on the ellipse of the operative condyle corresponding to the maximum projection as the initial reference point of the prosthesis pose;

[0028] Adjust the position of the initial reference point of the prosthesis pose to obtain the final reference point of the prosthesis pose.

[0029] Preferably, the method for adjusting the position of the initial reference point of the prosthesis pose includes:

[0030] Obtain the lowest point in the operative condyle region parallel to the Z-axis direction of the tibial coordinate system;

[0031] Move the initial reference point of the prosthesis pose along the Z-axis direction parallel to the tibial coordinate system so that the height of the initial reference point of the prosthesis pose is the same as that of the lowest point in the Z-axis direction parallel to the tibial coordinate system, and update the initial reference point of the prosthesis pose;

[0032] Adjust the position of the updated initial reference point of the prosthesis pose to obtain the final reference point of the prosthesis pose.

[0033] Preferably, the method for adjusting the position of the updated initial reference point of the prosthesis pose includes:

[0034] Taking the updated initial reference point of the prosthesis pose as the starting point, draw a straight line along the Y-axis direction parallel to the tibial coordinate system, and the straight line intersects the tibial surface at a first intersection point and a second intersection point;

[0035] Calculate the midpoint of the first intersection point and the second intersection point, and take the midpoint as the final reference point of the prosthesis pose parameter.

[0036] Preferably, the method for calculating the size of the operative condyle prosthesis region includes:

[0037] Calculate the distance between the first intersection point and the second intersection point, and use the distance between the first intersection point and the second intersection point as the maximum width of the prosthesis area of the operative condyle;

[0038] Along the direction parallel to the X-axis of the tibial coordinate system, with the final reference point of the prosthesis pose as the starting point, draw a ray towards the operative condyle side, and the ray intersects the tibial surface at a third intersection point;

[0039] Calculate the distance between the third intersection point and the final reference point of the prosthesis pose, and use the distance between the third intersection point and the final reference point of the prosthesis pose as the maximum length of the prosthesis area of the operative condyle.

[0040] Preferably, the method for matching alternative prosthesis models and obtaining the installation pose of each alternative prosthesis model includes:

[0041] Obtain the prosthesis width and prosthesis length corresponding to all prosthesis models in the database;

[0042] Select the prosthesis models with a prosthesis width less than the maximum width of the prosthesis area of the operative condyle and a prosthesis length less than the maximum length of the prosthesis area of the operative condyle as alternative prosthesis models;

[0043] Obtain the initial pose information of each alternative prosthesis model, where the initial pose information includes the initial pose origin of the prosthesis and three initial pose normal vectors with the initial pose origin as the starting point;

[0044] Move the initial pose origin of each alternative prosthesis model to the position of the final reference point of the prosthesis pose, and make the three normal vectors corresponding to the initial pose origin parallel to the X-axis, Y-axis, and Z-axis of the tibial coordinate system respectively, so as to obtain the installation pose of each alternative prosthesis model.

[0045] Preferably, the method for obtaining the optimal prosthesis model includes:

[0046] According to the installation pose of each alternative prosthesis model, screen out the alternative prosthesis models whose prosthesis cross-section is within the boundary of the tibial cross-section, and use the alternative prosthesis model with the largest prosthesis width and the largest prosthesis length among the screened alternative prosthesis models as the optimal prosthesis model.

[0047] According to the second aspect of the present invention, there is provided a preoperative planning device for a tibial prosthesis, which is used to execute the preoperative planning method for the tibial prosthesis. The preoperative planning device for the tibial prosthesis includes:

[0048] An acquisition module, which is used to acquire the point set of the operative condyle area and the point set of the normal condyle area of the tibia;

[0049] A construction module, configured to merge the set of points of the surgical condyle region and the set of points of the normal condyle region to obtain a set of points of the tibial condyle region, and construct a tibial coordinate system according to the set of points of the tibial condyle region;

[0050] A calculation module, configured to calculate a final reference point of the prosthesis pose in the tibial coordinate system, and calculate the size of the surgical condyle prosthesis region according to the final reference point of the prosthesis pose;

[0051] A matching module, configured to match alternative prosthesis models according to the size of the surgical condyle prosthesis region, and obtain the installation pose of each alternative prosthesis model according to the alternative prosthesis model and the final reference point of the prosthesis pose;

[0052] A screening module, configured to obtain an optimal prosthesis model according to the installation pose of each alternative prosthesis model, and use the installation pose corresponding to the optimal prosthesis model as the optimal installation pose.

[0053] According to a third aspect of the present invention, there is provided an electronic device, including:

[0054] A processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory complete mutual communication through the communication bus;

[0055] The memory is used for storing a computer program;

[0056] The processor is configured to implement the described method when executing the program stored on the memory.

[0057] According to a third aspect of the present invention, there is provided a non-transitory computer-readable storage medium storing computer instructions for causing a computer to execute the described method.

[0058] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0059] Merge the set of points of the surgical condyle region and the set of points of the normal condyle region to obtain a set of points of the tibial condyle region, construct a tibial coordinate system according to the set of points of the tibial condyle region, calculate a final reference point of the prosthesis pose in the tibial coordinate system, calculate the size of the surgical condyle prosthesis region according to the final reference point of the prosthesis pose, and then match the optimal prosthesis model and the optimal installation pose according to the size of the surgical condyle prosthesis region, effectively using the characteristic information of the normal condyle to assist in modeling, constructing a more reasonable tibial coordinate system, and improving the accuracy of prosthesis model matching and prosthesis pose planning. Description of the Drawings

[0060] Figure 1 is a flowchart of a method for preoperative planning of a tibial prosthesis shown according to an exemplary embodiment;

[0061] Figure 2 It is a schematic diagram of the effect of a method for establishing a tibial coordinate system shown according to another exemplary embodiment;

[0062] Figure 3 It is a schematic diagram of the effect of a final reference point of a prosthesis pose shown according to another exemplary embodiment;

[0063] Figure 4 It is a schematic diagram of the effect of calculating the size of the operative condyle prosthesis area and the prosthesis pose shown according to another exemplary embodiment;

[0064] Figure 5 It is a schematic structural diagram of a tibial prosthesis preoperative planning device shown according to another exemplary embodiment;

[0065] Figure 6 It is a schematic structural diagram of an electronic device shown according to another exemplary embodiment. Detailed implementation manners

[0066] In order to enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0067] Embodiment 1

[0068] Figure 1 It is a flowchart of a method for preoperative planning of a tibial prosthesis shown according to an exemplary embodiment, as Figure 1 shown, the method for preoperative planning of the tibial prosthesis includes:

[0069] Step S11, obtaining a set of points in the operative condyle area and a set of points in the normal condyle area of the tibia;

[0070] Step S12, combining the set of points in the operative condyle area and the set of points in the normal condyle area to obtain a set of points in the tibial condyle area, and constructing a tibial coordinate system according to the set of points in the tibial condyle area;

[0071] Step S13, calculating a final reference point of the prosthesis pose in the tibial coordinate system, and calculating the size of the operative condyle prosthesis area according to the final reference point of the prosthesis pose;

[0072] Step S14, matching alternative prosthesis models according to the size of the operative condyle prosthesis area, and obtaining the installation pose of each alternative prosthesis model according to the alternative prosthesis model and the final reference point of the prosthesis pose;

[0073] Step S15: Obtain the optimal prosthesis model according to the installation pose of each alternative prosthesis model, and use the installation pose corresponding to the optimal prosthesis model as the optimal installation pose.

[0074] It should be noted that the tibial condyle is a part of the human lower limb bone and plays an important role in stable walking and running. The tibial condyle is divided into the medial tibial condyle and the lateral tibial condyle, and the structures of the medial tibial condyle and the lateral tibial condyle are highly similar. In unicompartmental knee arthroplasty, the diseased tibial condyle on one side is called the operative condyle, and the other tibial condyle corresponding to the operative condyle is the normal condyle (for example: if the medial tibial condyle is diseased, then the medial tibial condyle is the operative condyle and the lateral tibial condyle is the normal condyle). Doctors need to use a prosthesis to replace the operative condyle (the prosthesis is usually made of materials such as metal, plastic, or ceramic and is used to simulate the structure and function of the natural joint) to restore the function of the tibial condyle.

[0075] It should be noted that the pose of the prosthesis refers to the position and orientation of the prosthesis installed on the human body. In unicompartmental knee arthroplasty, the correct prosthesis pose can ensure the force balance between the medial and lateral tibial condyles and avoid prosthesis detachment.

[0076] In the technical solution provided in this embodiment, the operative condyle region point set and the normal condyle region point set of the tibia are combined to obtain the tibial condyle region point set. According to the tibial condyle region point set, a tibial coordinate system is constructed. In the tibial coordinate system, the final reference point of the prosthesis pose is calculated. According to the final reference point of the prosthesis pose, the size of the operative condyle prosthesis region is calculated. Then, according to the size of the operative condyle prosthesis region, the optimal prosthesis model and the optimal installation pose are matched, effectively using the characteristic information of the normal condyle to assist in modeling, constructing a more reasonable tibial coordinate system, and improving the accuracy of prosthesis model matching and prosthesis pose planning.

[0077] In specific practice, the method for obtaining the operative condyle region point set and the normal condyle region point set of the tibia includes:

[0078] Obtain the contour feature point set of the operative condyle and the contour feature point set of the normal condyle of the tibia;

[0079] According to the contour feature point set of the operative condyle, the operative condyle region is segmented to obtain the operative condyle region point set. According to the contour feature point set of the normal condyle, the normal condyle region is segmented to obtain the normal condyle region point set.

[0080] As Figure 2 (a) shows, the contour feature point set of the operative condyle and the contour feature point set of the normal condyle are respectively selected; as Figure 2 (b) shows, according to the contour feature point set of the operative condyle, the operative condyle region is segmented, and the set of all points within the operative condyle region is the operative condyle region point set. According to the contour feature point set of the normal condyle, the normal condyle region is segmented, and the set of all points within the normal condyle region is the normal condyle region point set.

[0081] The technical solution provided by this embodiment divides the affected-side condyle region according to the set of characteristic points of the affected-side condyle contour, obtains the point set of the affected-side condyle region, divides the normal condyle region according to the set of characteristic points of the normal condyle contour, obtains the point set of the normal condyle region, and completely extracts the regional characteristic information of the affected-side condyle region and the normal condyle region.

[0082] In specific practice, the method for constructing the tibial coordinate system according to the point set of the tibial condyle region includes:

[0083] By using a plane fitting algorithm, fitting the point set of the tibial condyle region to obtain the X-axis, Y-axis, and Z-axis of the tibial coordinate system;

[0084] Calculating the average point of the point set of the tibial condyle region and using the average point as the origin of the tibial coordinate system.

[0085] It should be noted that the plane fitting algorithm is a common method in the field of image processing, which is used to fit the best three-dimensional plane model according to a three-dimensional point set. As shown in Figure 2 (c) and Figure 2 (d), by using the plane fitting algorithm to fit the point set of the tibial condyle region, the X-axis, Y-axis, and Z-axis of the fitted plane are obtained, then the average point of the point set of the tibial condyle region is calculated, and the average point is used as the origin of the tibial coordinate system, obtaining a three-dimensional tibial coordinate system. In the process of establishing the tibial coordinate system, the characteristic information of the normal condyle is effectively utilized, making the tibial coordinate system more reasonable and contributing to subsequent quantitative measurement and analysis of the tibial structure.

[0086] In specific practice, the method for calculating the final reference point of the prosthesis pose includes:

[0087] Fitting an ellipse of the tibial plateau according to the point set of the affected-side condyle region and the point set of the normal condyle region;

[0088] Calculating the center of the ellipse of the tibial plateau and the affected-side condyle focus of the ellipse of the tibial plateau;

[0089] Calculating the initial reference point of the prosthesis pose according to the center of the ellipse of the tibial plateau and the affected-side condyle focus;

[0090] Adjusting the position of the initial reference point of the prosthesis pose to obtain the final reference point of the prosthesis pose.

[0091] As shown in Figure 3 (a), according to the edge points in the point set of the affected-side condyle region and the edge points in the point set of the normal condyle region, an ellipse of the tibial plateau is fitted. The ellipse of the tibial plateau has a center and two foci, and one of the foci falls within the affected-side condyle region, which is the affected-side condyle focus.

[0092] In specific practice, the method for calculating the initial reference point of the prosthesis pose based on the center of the tibial plateau ellipse and the focus of the surgical condyle side includes:

[0093] Calculate the direction vector F from the focus of the surgical condyle side to the center of the tibial plateau ellipse;

[0094] According to the point set of the surgical condyle area, fit the surgical condyle ellipse, and calculate the direction vector P from the focus of the surgical condyle side to each point on the surgical condyle ellipse i , where i is the identification number of the point on the surgical condyle ellipse, i≥0 and is an integer;

[0095] Calculate the projection of the direction vector P i onto the direction vector F, and set the point on the surgical condyle ellipse corresponding to the maximum projection as the initial reference point of the prosthesis pose;

[0096] Adjust the position of the initial reference point of the prosthesis pose to obtain the final reference point of the prosthesis pose.

[0097] As Figure 3 (b) shows, the edge of the surgical condyle area is irregular, and it is necessary to fit a surgically condyle ellipse with a regular shape according to the point set of the surgical condyle area; as Figure 3 (c) shows, by calculating the projection of the direction vector P i onto the direction vector F, and selecting the point on the surgical condyle ellipse corresponding to the maximum projection as the initial reference point of the prosthesis pose.

[0098] In specific practice, the method for adjusting the position of the initial reference point of the prosthesis pose includes:

[0099] Obtain the lowest point in the surgical condyle area in the direction parallel to the Z-axis of the tibial coordinate system;

[0100] Move the initial reference point of the prosthesis pose along the direction parallel to the Z-axis of the tibial coordinate system so that the height of the initial reference point of the prosthesis pose in the direction parallel to the Z-axis of the tibial coordinate system is the same as that of the lowest point, and update the initial reference point of the prosthesis pose;

[0101] Adjust the position of the updated initial reference point of the prosthesis pose to obtain the final reference point of the prosthesis pose.

[0102] In specific practice, the method for adjusting the position of the updated initial reference point of the prosthesis pose includes:

[0103] Taking the updated initial reference point of the prosthesis pose as the starting point, draw a straight line along the direction parallel to the Y-axis of the tibial coordinate system, and the straight line intersects the tibial surface at a first intersection point and a second intersection point;

[0104] Calculate the midpoint of the first intersection point and the second intersection point, and use the midpoint as the final reference point for the prosthesis pose parameter.

[0105] It should be noted that since the prosthesis area is three-dimensional, it is necessary to adjust the initial reference point of the prosthesis pose to avoid deviations in subsequent calculations of the size of the prosthesis area on the surgical side condyle and the prosthesis installation pose. In the technical solution provided in this embodiment, as Figure 4 (a) shows, first move the initial reference point of the prosthesis pose so that the height of the initial reference point of the prosthesis pose is the same as the lowest point in the Z-axis direction parallel to the tibia coordinate system. Then, taking the updated initial reference point of the prosthesis pose as the starting point, draw a straight line along the Y-axis direction parallel to the tibia coordinate system. The straight line intersects the tibia surface at the first intersection point and the second intersection point. Calculate the midpoint of the first intersection point and the second intersection point, and use the midpoint as the final reference point for the prosthesis pose parameter. The final reference point for the prosthesis pose parameter can match the three-dimensional feature information of the prosthesis area on the surgical side condyle, enabling the installation pose of the prosthesis to fit the prosthesis area on the surgical side condyle. The final reference point for the prosthesis pose parameter can also be used as a reference point for calculating the size of the prosthesis area on the surgical side condyle, further ensuring the rationality of prosthesis selection.

[0106] In specific practice, the method for calculating the size of the prosthesis area on the surgical side condyle includes:

[0107] Calculate the distance between the first intersection point and the second intersection point, and use the distance between the first intersection point and the second intersection point as the maximum width of the prosthesis area on the surgical side condyle;

[0108] Along the X-axis direction parallel to the tibia coordinate system, taking the final reference point of the prosthesis pose as the starting point, draw a ray towards the surgical side condyle. The ray intersects the tibia surface at the third intersection point;

[0109] Calculate the distance between the third intersection point and the final reference point of the prosthesis pose, and use the distance between the third intersection point and the final reference point of the prosthesis pose as the maximum length of the prosthesis area on the surgical side condyle.

[0110] As Figure 4 (a) shows, calculate the distance between the first intersection point and the second intersection point as the maximum width of the prosthesis area on the surgical side condyle, and calculate the distance between the third intersection point and the final reference point of the prosthesis pose as the maximum length of the prosthesis area on the surgical side condyle. As Figure 4 (b) shows, the maximum width and the maximum length define the size range of the prosthesis. Combining the position of the final reference point of the prosthesis pose, the maximum contour of the prosthesis can be simulated, ensuring the rationality of prosthesis selection.

[0111] In specific practice, the method for matching alternative prosthesis models includes:

[0112] Obtain the prosthesis width and prosthesis length corresponding to all prosthesis models in the database;

[0113] Select the prosthesis models whose prosthesis width is less than the maximum width of the prosthesis area on the operative condyle side and whose prosthesis length is less than the maximum length of the prosthesis area on the operative condyle side as the alternative prosthesis models.

[0114] Table 1

[0115] Prosthesis Model Prosthesis Length (mm) Prosthesis Width (mm) Type Ⅰ Prosthesis 30 24 Type Ⅱ Prosthesis 33 26 Type Ⅲ Prosthesis 35 28

[0116] As shown in Table 1, if the calculated maximum width of the prosthesis area on the operative condyle side is 28 mm and the calculated maximum length of the prosthesis area on the operative condyle side is 34 mm, according to the data in Table 1, the prosthesis length of Model III prosthesis is greater than the maximum length of the prosthesis area on the operative condyle side, while the prosthesis lengths of Model I prosthesis and Model II prosthesis are both less than the maximum length of the prosthesis area on the operative condyle side, and their prosthesis widths are both less than the maximum width of the prosthesis area on the operative condyle side. Therefore, select Model I prosthesis and Model II prosthesis as the alternative prosthesis models to avoid the prosthesis size exceeding the prosthesis area on the operative condyle side.

[0117] In specific practice, the method for obtaining the installation pose of each alternative prosthesis model includes:

[0118] Obtain the initial pose information of each alternative prosthesis model, where the initial pose information includes the initial pose origin of the prosthesis and three initial pose normal vectors starting from the initial pose origin;

[0119] Obtain the installation pose of each alternative prosthesis model according to the initial pose information corresponding to each alternative prosthesis model.

[0120] It should be noted that the three initial pose normal vectors are the three coordinate axes of the prosthesis three-dimensional coordinate system, represented by X m 、Y m and Z m The origin of the prosthesis three-dimensional coordinate system is the initial pose origin of the prosthesis, and the prosthesis three-dimensional coordinate system is used to represent the initial pose of the prosthesis.

[0121] In specific practice, the method for obtaining the installation pose of each alternative prosthesis model includes:

[0122] Move the initial pose origin of each alternative prosthesis model to the position of the final reference point of the prosthesis pose, and make the three normal vectors corresponding to the initial pose origin parallel to the X-axis, Y-axis, and Z-axis of the tibia coordinate system respectively, so as to obtain the installation pose of each alternative prosthesis model.

[0123] Such as Figure 4As shown in (c), there is a deviation between the initial pose of the prosthesis and the installation pose of the prosthesis. In order to enable the prosthesis to fit into the prosthesis area of the operative condyle during the simulated installation of the prosthesis, it is necessary to adjust the initial pose of the prosthesis to obtain the installation pose of the prosthesis, as follows:

[0124] Calculate the rotation axis and angle between the X-axis of the three-dimensional coordinate system of the prosthesis and the X-axis of the tibia coordinate system to obtain the first transformation matrix; m

[0125] Calculate the transformation vector of the Y-axis through the first transformation matrix, and then calculate the rotation axis and angle between the transformation vector of the Y-axis and the Y-axis of the tibia coordinate system to obtain the second transformation matrix; m m

[0126] Update the second transformation matrix with the translation amount using the final reference point of the prosthesis pose to obtain the pose transformation matrix;

[0127] According to the pose transformation matrix, the origin of the initial pose of the prosthesis can be moved to the position of the final reference point of the prosthesis pose, and the X-axis of the three-dimensional coordinate system of the prosthesis is parallel to the X-axis of the tibia coordinate system, the Y-axis is parallel to the Y-axis of the tibia coordinate system, and the Z-axis is parallel to the Z-axis of the tibia coordinate system, thereby obtaining the installation pose of the prosthesis. m m m

[0128] In specific practice, the method for obtaining the optimal prosthesis model includes:

[0129] According to the installation poses of each alternative prosthesis model, select the alternative prosthesis models whose cross-sections of the prosthesis are within the boundaries of the cross-section of the tibia, and use the alternative prosthesis model with the largest prosthesis width and the largest prosthesis length among the selected alternative prosthesis models as the optimal prosthesis model.

[0130] It should be noted that in the installation pose, the cross-section of the prosthesis is within the boundaries of the cross-section of the tibia, indicating that the prosthesis will not exceed the prosthesis area of the operative condyle, thus completing the first screening of the alternative prosthesis models. Then, select the alternative prosthesis model with the largest prosthesis width and the largest prosthesis length from the alternative prosthesis models after the first screening as the optimal prosthesis model (the larger the prosthesis model, the larger the length and width of the prosthesis), and use the installation pose corresponding to the optimal prosthesis model as the optimal installation pose, which can ensure that the prosthesis can best fit into the prosthesis area of the operative condyle and avoid prosthesis detachment.

[0131] ​​​​​​The technical solution provided in this embodiment is to obtain the initial pose information of each alternative prosthesis model, obtain the installation pose of each alternative prosthesis model according to the initial pose information corresponding to each alternative prosthesis model, screen out the alternative prosthesis models whose prosthesis cross-sections are within the boundary of the tibial cross-section according to the installation poses of each alternative prosthesis model, select the alternative prosthesis model with the largest prosthesis width and the largest prosthesis length among the screened alternative prosthesis models as the optimal prosthesis model, and use the installation pose corresponding to the optimal prosthesis model as the optimal installation pose, which can ensure that the prosthesis can best fit the prosthesis area of the operative condyle and avoid prosthesis detachment.

[0132] Embodiment 2

[0133] Figure 5 FIG. 100 is a schematic structural diagram of a preoperative planning device for a tibial prosthesis shown according to another exemplary embodiment, as Figure 5 shown, the preoperative planning device for a tibial prosthesis includes:

[0134] An acquisition module 101, configured to acquire a point set of the operative condyle region and a point set of the normal condyle region of the tibia;

[0135] A construction module 102, configured to merge the point set of the operative condyle region and the point set of the normal condyle region to obtain a point set of the tibial condyle region, and construct a tibial coordinate system according to the point set of the tibial condyle region;

[0136] A calculation module 103, configured to calculate a final reference point of the prosthesis pose in the tibial coordinate system, and calculate the size of the prosthesis area of the operative condyle according to the final reference point of the prosthesis pose;

[0137] A matching module 104, configured to match alternative prosthesis models according to the size of the prosthesis area of the operative condyle, and obtain the installation pose of each alternative prosthesis model according to the alternative prosthesis model and the final reference point of the prosthesis pose;

[0138] A screening module 105, configured to obtain an optimal prosthesis model according to the installation pose of each alternative prosthesis model, and use the installation pose corresponding to the optimal prosthesis model as the optimal installation pose.

[0139] In the technical solution provided in this embodiment, an acquisition module 101, a construction module 102, a calculation module 103, a matching module 104, and a screening module 105 are provided in the tibial prosthesis preoperative planning device 100. The point sets of the operative condyle region and the normal condyle region are combined to obtain the tibial condyle region point set. According to the tibial condyle region point set, a tibial coordinate system is constructed. In the tibial coordinate system, the final reference point of the prosthesis pose is calculated. According to the final reference point of the prosthesis pose, the size of the operative condyle prosthesis region is calculated. Then, according to the size of the operative condyle prosthesis region, the optimal prosthesis model and the optimal installation pose are matched. The characteristic information of the normal condyle is effectively utilized to assist in modeling, a more reasonable tibial coordinate system is constructed, and the accuracy of prosthesis model matching and prosthesis pose planning is improved.

[0140] Embodiment III

[0141] Figure 6 is a schematic structural diagram of an electronic device shown according to another exemplary embodiment, as Figure 6 shown, the electronic device includes:

[0142] A processor 701, a communication interface 702, a memory 703, and a communication bus 704. Among them, the processor 701, the communication interface 702, and the memory 703 complete mutual communication through the communication bus 704;

[0143] The memory 703 is used to store a computer program;

[0144] The processor 701 is used to implement the described method when executing the program stored on the memory.

[0145] In the technical solution provided in this embodiment, a processor 701, a communication interface 702, a memory 703, and a processor 704 are provided in the electronic device. The point sets of the operative condyle region and the normal condyle region are combined to obtain the tibial condyle region point set. According to the tibial condyle region point set, a tibial coordinate system is constructed. In the tibial coordinate system, the final reference point of the prosthesis pose is calculated. According to the final reference point of the prosthesis pose, the size of the operative condyle prosthesis region is calculated. Then, according to the size of the operative condyle prosthesis region, the optimal prosthesis model and the optimal installation pose are matched. The characteristic information of the normal condyle is effectively utilized to assist in modeling, a more reasonable tibial coordinate system is constructed, and the accuracy of prosthesis model matching and prosthesis pose planning is improved.

[0146] Embodiment IV

[0147] A non-transitory computer-readable storage medium storing computer instructions, where the computer instructions are used to cause a computer to execute the described method.

[0148] The technical solution provided in this embodiment combines the point set of the surgical condyle region and the point set of the normal condyle region through the non-transitory computer-readable storage medium storing computer instructions to obtain the tibial condyle region point set, constructs a tibial coordinate system based on the tibial condyle region point set, calculates the final reference point of the prosthesis pose in the tibial coordinate system, calculates the size of the surgical condyle prosthesis region based on the final reference point of the prosthesis pose, and then matches the optimal prosthesis model and the optimal installation pose according to the size of the surgical condyle prosthesis region. It effectively utilizes the characteristic information of the normal condyle to assist in modeling, constructs a more reasonable tibial coordinate system, and improves the accuracy of prosthesis model matching and prosthesis pose planning.

[0149] The serial numbers of the above embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0150] If the integrated unit in the above embodiments is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in the above computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in the storage medium and includes several instructions for causing one or more computer devices (which can be personal computers, servers, or network devices, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application.

[0151] In the above embodiments of the present application, the descriptions of the various embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0152] In several embodiments provided by the present application, it should be understood that the disclosed client can be implemented in other ways. Among them, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection can be through some interfaces, and the indirect coupling or communication connection of the units or modules can be in an electrical or other form.

[0153] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0154] In addition, in each embodiment of the present application, each functional unit can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0155] The above are only the preferred embodiments of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A preoperative planning method for a tibial prosthesis, wherein the tibial condyle includes the operative condyle and the normal condyle, characterized in that, The preoperative planning method for the tibial prosthesis includes: Obtaining a set of points in the operative condyle region and a set of points in the normal condyle region of the tibia; Combining the set of points in the operative condyle region and the set of points in the normal condyle region to obtain a set of points in the tibial condyle region, and constructing a tibial coordinate system based on the set of points in the tibial condyle region; Calculating the final reference point of the prosthesis pose in the tibial coordinate system, and calculating the size of the operative condyle prosthesis region based on the final reference point of the prosthesis pose; Matching alternative prosthesis models according to the size of the operative condyle prosthesis region, and obtaining the installation pose of each alternative prosthesis model based on the alternative prosthesis model and the final reference point of the prosthesis pose; Obtaining the optimal prosthesis model according to the installation pose of each alternative prosthesis model, and taking the installation pose corresponding to the optimal prosthesis model as the optimal installation pose.

2. The preoperative planning method for the tibial prosthesis according to claim 1, characterized in that, The method for obtaining the set of points in the operative condyle region and the set of points in the normal condyle region of the tibia includes: Obtaining a set of contour feature points in the operative condyle and a set of contour feature points in the normal condyle of the tibia; Segmenting the operative condyle region according to the set of contour feature points in the operative condyle to obtain a set of points in the operative condyle region, and segmenting the normal condyle region according to the set of contour feature points in the normal condyle to obtain a set of points in the normal condyle region. The method for constructing a tibial coordinate system based on the set of points in the tibial condyle region includes: Fitting the set of points in the tibial condyle region by a plane fitting algorithm to obtain the X-axis, Y-axis, and Z-axis of the tibial coordinate system; Calculating the average point of the set of points in the tibial condyle region, and taking the average point as the origin of the tibial coordinate system.

3. The preoperative planning method for a tibial prosthesis according to claim 1, wherein The method for calculating the final reference point of the prosthesis pose includes: Fitting an ellipse of the tibial plateau according to the set of points in the operative condyle region and the set of points in the normal condyle region; Calculating the center of the ellipse of the tibial plateau and the operative condyle focus of the ellipse of the tibial plateau; Calculating the initial reference point of the prosthesis pose based on the center of the ellipse of the tibial plateau and the operative condyle focus; Adjusting the position of the initial reference point of the prosthesis pose to obtain the final reference point of the prosthesis pose.

4. The preoperative planning method for the tibial prosthesis according to claim 3, wherein The method for calculating the initial reference point of the prosthesis pose based on the center of the ellipse of the tibial plateau and the operative condyle focus includes: Calculating the direction vector F from the operative condyle focus to the center of the ellipse of the tibial plateau; According to the set of points in the surgical condyle region, fit an ellipse of the surgical condyle, and calculate the direction vector P from the focus of the surgical condyle to each point on the ellipse of the surgical condyle i , where i is the identification number of the point on the ellipse of the surgical condyle, i≥0 and is an integer; Calculate the direction vector P i Project it onto the direction vector F, and set the point on the contralateral condylar ellipse corresponding to the maximum projection as the initial reference point for the prosthesis pose; Adjusting the position of the initial reference point of the prosthesis pose to obtain the final reference point of the prosthesis pose.

5. The preoperative planning method for the tibial prosthesis according to claim 4, wherein The method for adjusting the position of the initial reference point of the prosthesis pose includes: Obtaining the lowest point in the operative condyle region parallel to the Z-axis direction of the tibial coordinate system; Moving the initial reference point of the prosthesis pose along the Z-axis direction parallel to the tibial coordinate system so that the height of the initial reference point of the prosthesis pose in the Z-axis direction parallel to the tibial coordinate system is the same as that of the lowest point, and updating the initial reference point of the prosthesis pose; Adjusting the position of the updated initial reference point of the prosthesis pose to obtain the final reference point of the prosthesis pose.

6. The preoperative planning method for a tibial prosthesis according to claim 5, wherein, The method for adjusting the position of the updated initial reference point of the prosthesis pose includes: Taking the updated initial reference point of the prosthesis pose as the starting point, making a straight line along the Y-axis direction parallel to the tibial coordinate system, and the straight line intersects the tibial surface at a first intersection point and a second intersection point; Calculating the midpoint of the first intersection point and the second intersection point, and taking the midpoint as the final reference point of the prosthesis pose.

7. The preoperative planning method for the tibial prosthesis according to claim 6, wherein The method for calculating the size of the surgical condylar prosthesis area includes: Calculating the distance between the first intersection point and the second intersection point, and using the distance between the first intersection point and the second intersection point as the maximum width of the surgical condylar prosthesis area; Along the direction parallel to the X-axis of the tibial coordinate system, taking the final reference point of the prosthesis pose as the starting point, making a ray towards the surgical condylar side, and the ray intersects the tibial surface at a third intersection point; Calculating the distance between the third intersection point and the final reference point of the prosthesis pose, and using the distance between the third intersection point and the final reference point of the prosthesis pose as the maximum length of the surgical condylar prosthesis area.

8. The preoperative planning method for the tibial prosthesis according to claim 7, characterized in that, The method for matching alternative prosthesis models and obtaining the installation pose of each alternative prosthesis model includes: Obtaining the prosthesis width and prosthesis length corresponding to all prosthesis models in the database; Selecting the prosthesis models with a prosthesis width smaller than the maximum width of the surgical condylar prosthesis area and a prosthesis length smaller than the maximum length of the surgical condylar prosthesis area as alternative prosthesis models; Obtaining the initial pose information of each alternative prosthesis model, where the initial pose information includes the initial pose origin of the prosthesis and three initial pose normal vectors starting from the initial pose origin; Moving the initial pose origin of each alternative prosthesis model to the position of the final reference point of the prosthesis pose, and making the three normal vectors corresponding to the initial pose origin parallel to the X-axis, Y-axis, and Z-axis of the tibial coordinate system respectively, so as to obtain the installation pose of each alternative prosthesis model.

9. The preoperative planning method for a tibial prosthesis according to claim 1, wherein The method for obtaining the optimal prosthesis model includes: According to the installation pose of each alternative prosthesis model, screening out the alternative prosthesis models whose prosthesis cross-section is within the boundary of the tibial cross-section, and using the alternative prosthesis model with the largest prosthesis width and the largest prosthesis length among the screened alternative prosthesis models as the optimal prosthesis model.

10. A preoperative planning device for a tibial prosthesis, which is used to execute the preoperative planning method for the tibial prosthesis described in claim 1, and is characterized in that, The tibial prosthesis preoperative planning device includes: An acquisition module for acquiring the point set of the surgical condylar area and the point set of the normal condylar area of the tibia; A construction module for merging the point set of the surgical condylar area and the point set of the normal condylar area to obtain the point set of the tibial condylar area, and constructing a tibial coordinate system according to the point set of the tibial condylar area; A calculation module for calculating the final reference point of the prosthesis pose in the tibial coordinate system, and calculating the size of the surgical condylar prosthesis area according to the final reference point of the prosthesis pose; A matching module for matching alternative prosthesis models according to the size of the surgical condylar prosthesis area, and obtaining the installation pose of each alternative prosthesis model according to the alternative prosthesis model and the final reference point of the prosthesis pose; A screening module for obtaining the optimal prosthesis model according to the installation pose of each alternative prosthesis model, and using the installation pose corresponding to the optimal prosthesis model as the optimal installation pose.

11. An electronic device, characterized in that, Includes: A processor, a communication interface, a memory, and a communication bus. Among them, the processor, the communication interface, and the memory complete communication with each other through the communication bus; A memory for storing computer programs; A processor for implementing the method according to any one of claims 1 to 9 when executing the program stored on the memory.

12. A non-transitory computer-readable storage medium storing computer instructions, characterized in that, The computer instructions are used to cause the computer to execute the method according to any one of claims 1 to 9.

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