Implant positioning methods, systems, and storage media for knee arthroplasty

Abstract

The application relates to a knee replacement implant positioning method, system and storage medium. The method comprises the following steps: acquiring a three-dimensional bone model of an anatomical structure; the three-dimensional bone model is a three-dimensional femur model and / or a three-dimensional tibia model; marking a plurality of anatomical landmark points on the three-dimensional bone model; establishing a bone coordinate system of the three-dimensional bone model according to the adjusted anatomical landmark points; and placing an implant three-dimensional model on the three-dimensional bone model under the bone coordinate system or an image coordinate system. The method can fine-tune the positions of the anatomical landmark points, and accurate implant positioning planning values can be obtained; the bone coordinate system established according to the adjusted anatomical landmark points can solve the position error problem caused by the fact that the bones are not directly opposite to the image coordinate system when the patient takes CT, so that the position parameters of the prosthesis placement are more accurate; the implant placement parameters are calculated in a simulation mode, instead of the manual adjustment mode, so that the automation and intelligent degree can be improved.

Description

Technical Field

[0001] This application relates to the field of robot navigation technology, and in particular to a method, system and storage medium for implant placement in knee replacement surgery. Background Technology

[0002] Computer-assisted joint replacement surgery first requires determining the osteotomy plan through preoperative implant placement. Then, a robotic arm, based on the pre-determined plan, locates the corresponding osteotomy position to assist the surgeon in performing the procedure. Current implant placement methods rely on manual adjustment of the implant's position on the bone. This subjective approach is prone to error and inefficient. While some methods use anatomical landmarks to determine implant placement parameters, these are manually selected, leading to subjective errors that affect placement accuracy. Furthermore, the bone may not be aligned with the CT coordinate system during CT scans, resulting in inaccurate prosthesis placement parameters. Summary of the Invention

[0003] Therefore, it is necessary to provide a method, system, and storage medium for implant placement in knee replacement surgery that can improve the accuracy of implant placement, addressing the aforementioned technical problems.

[0004] In a first aspect, this application provides a method for implant placement in knee replacement surgery. The method includes:

[0005] Obtain a 3D model of the anatomical structure of the skeleton; the 3D model of the skeleton is a 3D model of the femur and / or the tibia;

[0006] Multiple anatomical landmarks are marked on the 3D skeletal model, and their positions are adjusted to obtain the adjusted anatomical landmarks.

[0007] Based on the adjusted anatomical landmarks, establish the skeletal coordinate system of the three-dimensional skeletal model;

[0008] Place the implant 3D model on the skeletal 3D model in the skeletal coordinate system or image coordinate system.

[0009] In one embodiment, the anatomical landmarks are repositioned to obtain adjusted anatomical landmarks, including:

[0010] Centered on anatomical landmarks and within a preset cube, the voxel points of the 3D skeletal model are traversed to identify target voxel points that meet preset search conditions. These target voxel points are then used as adjusted anatomical landmarks. The preset search condition is that the vector from the anatomical landmark to the target voxel point has the largest projection length in the direction perpendicular to the vector in the skeletal coordinate system of the 3D skeletal model.

[0011] In one embodiment, the anatomical landmarks include at least three anatomical landmarks protruding in the coronal view of the 3D skeletal model and at least two anatomical landmarks protruding in the sagittal view of the 3D skeletal model; establishing a skeletal coordinate system for the 3D skeletal model based on the adjusted anatomical landmarks includes:

[0012] Based on at least three anatomical landmarks on the coronal view of the 3D skeletal model, determine the normal vector of the coronal view and use the normal vector as the vertical axis of the skeletal coordinate system of the 3D skeletal model.

[0013] The line vector connecting two anatomical landmarks on the sagittal view of the 3D skeletal model is used as the vertical axis of the skeletal coordinate system of the 3D skeletal model.

[0014] The cross product vector of the vertical and y-axis is used as the x-axis of the skeletal coordinate system of the 3D skeletal model.

[0015] In one embodiment, establishing the skeletal coordinate system for the 3D skeletal model based on the adjusted anatomical landmarks further includes:

[0016] Using any anatomical landmark as the base point, and the cross product of the vertical axis of the skeletal coordinate system and the vertical axis of the image coordinate system as the rotation axis, rotate the skeletal coordinate system until the vertical axis of the skeletal coordinate system is parallel to the vertical axis of the image coordinate system.

[0017] Rotate the skeletal coordinate system around the vertical axis of the image coordinate system until the horizontal axis of the skeletal coordinate system is parallel to the horizontal axis of the image coordinate system.

[0018] In one embodiment, placing the implant 3D model on a 3D skeletal model in a skeletal coordinate system or an image coordinate system includes:

[0019] Determine the dimensions of the 3D skeletal model;

[0020] Based on the size values, determine the 3D model of the implant that matches the size values;

[0021] Based on the osteotomy amount and rotation angle adapted to the 3D model of the implant, the 3D model of the implant is installed on the 3D model of the bone so that the rotation angle and osteotomy amount of the 3D model of the implant after installation are the same as the adapted rotation angle and osteotomy amount.

[0022] In one embodiment, determining the dimensional values ​​of the skeletal 3D model includes:

[0023] Using anatomical landmarks on the coronal view of the 3D skeletal model as base points, the voxel points on the coronal view of the 3D skeletal model are traversed to determine the target voxel point that meets the preset conditions. The preset conditions are to maximize the projection length of the vector from the target voxel point to the anatomical landmark point in the axial direction of the skeletal coordinate system.

[0024] The magnitude of the vector from the target voxel to the anatomical landmark is used as the dimension value of the skeletal 3D model.

[0025] In one embodiment, based on the osteotomy amount and rotation angle adapted to the implant 3D model, the implant 3D model is mounted on the bone 3D model so that the rotation angle and osteotomy amount of the implant 3D model after mounting are the same as the adapted rotation angle and osteotomy amount, including:

[0026] For the three-dimensional space where the implant 3D model and the bone 3D model coexist, the implant coordinate system of the implant 3D model is aligned with the bone coordinate system of the bone 3D model to obtain the aligned implant 3D model; the vertical axis of the implant coordinate system is perpendicular to the mounting surface of the implant 3D model, the horizontal axis of the implant coordinate system is parallel to the mounting surface of the implant 3D model, and the vertical axis of the implant coordinate system is perpendicular to both the vertical axis and the horizontal axis of the implant coordinate system.

[0027] The implant 3D model is rotated and aligned in three-dimensional space until the rotation angle of the implant 3D model reaches the appropriate rotation angle.

[0028] The implant 3D model is moved and rotated in 3D space. The real-time osteotomy amount caused by the implant 3D model to the skeletal 3D model during the movement is calculated until the real-time osteotomy amount reaches the appropriate osteotomy amount.

[0029] In one embodiment, the rotation angle includes inversion / exversion angle, external rotation angle, and forward / backward tilt angle. The implant's 3D model is rotated and aligned in three-dimensional space until the rotation angle reaches the appropriate rotation angle, including:

[0030] Using the vertical axis of the skeletal coordinate system as the rotation axis and the appropriate inversion / exversion angle as the rotation angle, the 3D model of the implant after rotation and alignment is obtained, thus obtaining the positioning of the 3D model of the implant under the inversion / exversion angle, and the implant coordinate system in the first posture.

[0031] Determine the condylar line of the skeletal 3D model, the projection vector on the XOY plane of the implant coordinate system in the first pose, the cross product vector of the projection vector and the horizontal axis of the implant coordinate system in the first pose as the rotation axis, and the appropriate internal and external rotation angle as the rotation angle, rotate the implant 3D model in the first pose to obtain the placement of the implant 3D model under the internal and external rotation angle, and the implant coordinate system in the second pose.

[0032] Rotate the implant 3D model in the second pose using the horizontal axis of the implant coordinate system as the rotation axis and the adapted forward and backward tilt angle as the rotation angle to obtain the placement of the implant 3D model under the forward and backward tilt angle, as well as the implant coordinate system in the third pose.

[0033] In one embodiment, the implant 3D model is moved and rotated in three-dimensional space, and the real-time osteotomy amount caused by the implant 3D model to the skeletal 3D model during the movement is calculated until the real-time osteotomy amount reaches the appropriate osteotomy amount, including:

[0034] After translating the center of the mounting surface of the implant 3D model to the center of the osteotomy surface of the bone 3D model, it moves along the vertical axis of the bone coordinate system. Based on the projection distance of the line connecting the anatomical landmarks of the bone 3D model and the center of the osteotomy surface of the bone 3D model in the vertical direction of the bone coordinate system, the real-time osteotomy amount caused by the implant 3D model to the bone 3D model during the movement is determined until the real-time osteotomy amount reaches the appropriate osteotomy amount.

[0035] Secondly, this application also provides an implant placement system for knee replacement surgery. The system includes a robotic device, surgical tools, and processing circuitry.

[0036] Surgical instruments are mounted on a robotic device; the robotic device guides the surgical instruments to place the implant onto the anatomical structure.

[0037] The processing circuitry is configured to: acquire a three-dimensional model of the anatomical structure of the skeleton; the three-dimensional model of the skeleton is a three-dimensional model of the femur and / or the tibia;

[0038] Multiple anatomical landmarks are marked on the 3D skeletal model; these anatomical landmarks are feature points whose positions have been adjusted.

[0039] Based on the adjusted anatomical landmarks, establish the skeletal coordinate system of the three-dimensional skeletal model;

[0040] Place the implant 3D model on the skeletal 3D model in the skeletal coordinate system or image coordinate system.

[0041] In one embodiment, the processing circuitry is further configured to generate a control object based on the placement of the implant, and to control the robotic device to confine the surgical instruments within the control object.

[0042] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to perform the following steps:

[0043] Obtain a 3D model of the anatomical structure of the skeleton; the 3D model of the skeleton is a 3D model of the femur and / or the tibia;

[0044] Mark multiple anatomical landmarks on the 3D skeletal model;

[0045] Based on the adjusted anatomical landmarks, establish the skeletal coordinate system of the three-dimensional skeletal model;

[0046] Place the implant 3D model on the skeletal 3D model in the skeletal coordinate system or image coordinate system.

[0047] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, performs the following steps:

[0048] Obtain a 3D model of the anatomical structure of the skeleton; the 3D model of the skeleton is a 3D model of the femur and / or the tibia;

[0049] Mark multiple anatomical landmarks on the 3D skeletal model;

[0050] Based on the adjusted anatomical landmarks, establish the skeletal coordinate system of the three-dimensional skeletal model;

[0051] Place the implant 3D model on the skeletal 3D model in the skeletal coordinate system or image coordinate system.

[0052] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, performs the following steps:

[0053] Obtain a 3D model of the anatomical structure of the skeleton; the 3D model of the skeleton is a 3D model of the femur and / or the tibia;

[0054] Mark multiple anatomical landmarks on the 3D skeletal model;

[0055] Based on the adjusted anatomical landmarks, establish the skeletal coordinate system of the three-dimensional skeletal model;

[0056] Place the implant 3D model on the skeletal 3D model in the skeletal coordinate system or image coordinate system.

[0057] The aforementioned method, system, and storage medium for implant placement in knee replacement surgery involves marking multiple anatomical landmarks on a three-dimensional skeletal model of the anatomical structure; establishing a skeletal coordinate system for the three-dimensional skeletal model based on the adjusted anatomical landmarks; and placing the three-dimensional implant model on the skeletal model within the skeletal coordinate system or the image coordinate system. By fine-tuning the positions of the anatomical landmarks, accurate implant placement planning values ​​can be obtained. The skeletal coordinate system established based on the adjusted anatomical landmarks solves the positional error problem caused by the bone not being aligned with the image coordinate system during CT scans, resulting in more accurate implant placement parameters. This invention calculates implant placement parameters through simulation, replacing manual adjustments and improving automation and intelligence. Attached Figure Description

[0058] Figure 1 This is an application scenario of an implant placement method in knee replacement surgery, as described in one embodiment.

[0059] Figure 2 This is a flowchart illustrating the implant placement method in a knee replacement surgery according to one embodiment.

[0060] Figure 3 This is a schematic diagram of a 3D skeletal model in one embodiment;

[0061] Figure 4 This is a schematic diagram of anatomical structures in the image coordinate system in another embodiment;

[0062] Figure 5 This is a schematic diagram of the coronal, transverse, and sagittal planes of a three-dimensional skeletal model in one embodiment;

[0063] Figure 6 This is a distribution diagram of anatomical landmarks shown in the coronal and sagittal views of a three-dimensional model of the femur in one embodiment;

[0064] Figure 7 This is a distribution diagram of anatomical landmarks shown in the coronal and sagittal views of a three-dimensional model of the tibia in one embodiment;

[0065] Figure 8 This is a schematic diagram of the automatic adjustment of initial anatomical landmarks on the coronal view of the femur in one embodiment;

[0066] Figure 9 This is a schematic diagram of the automatic adjustment of initial anatomical landmarks on the sagittal view of the tibia in one embodiment.

[0067] Figure 10 This is a flowchart illustrating the establishment of a skeletal coordinate system in one embodiment;

[0068] Figure 11A flowchart illustrating the establishment of a skeletal coordinate system via alignment in another embodiment;

[0069] Figure 12 for Figure 6 A schematic diagram showing the alignment of the three-dimensional model of the middle femur in the image coordinate system;

[0070] Figure 13 for Figure 7 A schematic diagram showing the alignment of the three-dimensional model of the middle tibia in the image coordinate system;

[0071] Figure 14 This is a flowchart illustrating the placement of a 3D model of an implant in a skeletal coordinate system in one embodiment.

[0072] Figure 15 This is a flowchart illustrating the determination of dimensional values ​​for a skeletal 3D model in one embodiment;

[0073] Figure 16 This is a schematic diagram illustrating the determination of dimensional values ​​for a three-dimensional model of the femur in one embodiment.

[0074] Figure 17 This is a schematic diagram illustrating the determination of dimensional values ​​for a three-dimensional model of the tibia in one embodiment.

[0075] Figure 18 This is a flowchart illustrating the matching of an implant 3D model onto a bone 3D model in one embodiment.

[0076] Figure 19 This is a schematic diagram of the implant coordinate system on a three-dimensional model of the femur in one embodiment;

[0077] Figure 20 This is a schematic diagram of the implant coordinate system on a three-dimensional model of the tibia in one embodiment;

[0078] Figure 21 A flowchart of a three-dimensional model of a rotating implant in one embodiment;

[0079] Figure 22 This is a schematic diagram of the transcondylar line of a three-dimensional femoral model in one embodiment;

[0080] Figure 23 This is a schematic diagram of the osteotomy surface on a three-dimensional model of the tibia in one embodiment;

[0081] Figure 24 This is a schematic diagram of the medial and lateral osteotomy amounts of the distal femur in one embodiment;

[0082] Figure 25 This is a schematic diagram of the medial and lateral osteotomy amounts at the posterior end of the femur in one embodiment;

[0083] Figure 26 This is a schematic diagram of the medial and lateral osteotomy amounts of the proximal tibia in one embodiment;

[0084] Figure 27 This is a final positioning diagram of the implant 3D model on the femoral 3D model and the tibia 3D model in one embodiment. Detailed Implementation

[0085] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0086] The implant placement method for knee replacement surgery provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, the joint replacement surgery robot first needs to determine the osteotomy plan through preoperative implant placement. Then, the robotic arm positions itself at the corresponding osteotomy location according to the preoperative osteotomy plan to assist the surgeon in completing the osteotomy operation. In this setup, patient 73 lies on operating table 81; robotic arm trolley 11 controls the movement of robotic arm 12; tool target 21 positions the end effector of the robotic arm; oscillating saw 41 performs osteotomy on the patient's femur 71 and tibia 72; osteotomy guide tool 31 provides direction during osteotomy; NIDI navigation device 51 tracks the positions of tool target 21, femoral target 22, tibial target 23, and base target 24 in real time; main display 62 and auxiliary display 52 display the pre-planned surgical plan and the navigation guidance process based on the pre-planned plan, respectively; navigation trolley 61 acquires pre-planned osteotomy surface information and implant internal / external rotation angles for patient 73, and sends this information to robotic arm trolley 11; input device 63 inputs patient and implant parameters. Base target 24 positions robotic arm trolley 11.

[0087] Existing implant placement methods rely on manual adjustment of the implant's position on the bone, a subjective approach that is prone to error and inefficient. While some methods use anatomical landmarks to determine implant placement parameters, these are manually selected and subject to subjective error, affecting placement accuracy. Furthermore, the bone may not be aligned with the CT coordinate system, leading to inaccurate implant placement parameters. Therefore, to address these issues, this embodiment marks multiple anatomical landmarks on the 3D bone model. Based on these adjusted landmarks, a skeletal coordinate system is established. When aligning the 3D bone model in either the skeletal or CT coordinate system, the alignment in the CT coordinate system is determined by ensuring the axes of both systems are parallel.

[0088] In one embodiment, such as Figure 2 As shown, a method for implant placement in knee replacement surgery is provided, including the following steps:

[0089] Step 202: Obtain a three-dimensional model of the anatomical structure of the skeleton; the three-dimensional model of the skeleton is a three-dimensional model of the femur and / or a three-dimensional model of the tibia.

[0090] Among them, a 3D skeletal model refers to a three-dimensional model built based on the three-dimensional information of anatomical structures such as the femur and / or tibia. The 3D skeletal model is presented in an image coordinate system, and a schematic diagram of the 3D skeletal model is shown below. Figure 3 As shown.

[0091] Optionally, the computer device acquires three-dimensional images of the anatomical structure, including CT, MRI, and other three-dimensional images; the computer device then displays the three-dimensional images of the anatomical structure in three directions: coronal, transverse, and sagittal (e.g.,...). Figure 4 As shown, this display allows operators to view three-dimensional images of anatomical structures from three perspectives: coronal, transverse, and sagittal. The computer equipment uses image segmentation or model reconstruction methods to obtain a three-dimensional skeletal model of the anatomical structure from the three-dimensional images. The coronal, transverse, and sagittal planes of the skeletal model are shown below. Figure 5 As shown.

[0092] Step 204: Mark multiple anatomical landmarks on the 3D skeletal model, adjust the positions of the anatomical landmarks, and obtain the adjusted anatomical landmarks.

[0093] Anatomical landmarks are feature points on a 3D skeletal model that characterize the anatomical features of the skeleton. These landmarks are used to determine implant placement parameters. Since many anatomical landmarks on the 3D skeletal model are manually selected and confirmed, their positions are subject to subjective errors, thus affecting the accuracy of implant placement. Therefore, to address this issue, this embodiment adjusts the positions of the anatomical landmarks, correcting errors from manual selection by the physician, improving the accuracy of the skeletal coordinate system, and ultimately enhancing the placement precision of the implant.

[0094] Taking the femur 3D model as an example, Figure 6 The image on the left shows the femur in a three-dimensional model, viewed from the coronal plane, with the femur at point A (posterior border of the greater trochanter), point B (medial posterior condyle), and point C (lateral posterior condyle). Figure 6 The image on the right shows the femoral head center point E and the knee joint center point F in the sagittal plane view of the 3D femoral model. Anatomical landmarks on the 3D femoral model can be... Figure 6 The coronal and sagittal views of the femur shown are marked by the following points: A, the posterior border of the greater trochanter; B, the medial tangent of the posterior condyle; C, the lateral tangent of the posterior condyle; E, the center of the femoral head; and F, the center of the knee joint.

[0095] Taking the 3D model of the tibia as an example, Figure 7 The image on the left shows the medial proximal tibial tangent point G, the lateral proximal tibial tangent point H, and the center point K of the talus in the coronal view of the tibial three-dimensional model. Figure 7 The image on the right shows the tibial plateau center J and talus center point K in the sagittal view of the femur of the tibial 3D model. Anatomical landmarks on the tibial 3D model can be... Figure 7 The coronal view of the tibia and the sagittal view of the femur show the medial proximal tibial tangent point G, the lateral proximal tibial tangent point H, the center point of the talus K, the center of the tibial plateau J, and the center point of the talus K.

[0096] Optionally, the computer device presents the three-dimensional model of the skeleton in an image coordinate system, and according to the skeletal features of the anatomical structure, marks multiple anatomical landmarks representing the anatomical features of the skeleton on the three-dimensional model of the skeleton, and adjusts the position of the anatomical landmarks to obtain the adjusted anatomical landmarks.

[0097] Step 206: Establish the skeletal coordinate system of the three-dimensional skeletal model based on the adjusted anatomical landmarks.

[0098] In order to ensure the accurate and reasonable placement of the implant, this embodiment establishes a skeletal coordinate system based on the adjusted anatomical landmarks, which provides an accurate basis for implant adjustment and thus improves the accuracy of implant placement.

[0099] Optionally, the computer device establishes a bone coordinate system for a three-dimensional femur model based on the location of anatomical landmarks, for example, Figure 6 As shown, the plane formed by connecting the posterior border point A of the greater trochanter, the medial tangent point B of the posterior condyle, and the lateral tangent point C of the posterior condyle in the coronal view of the femur in the 3D model of the femur is used as the XoZ two-dimensional plane of the skeletal coordinate system. The normal vector perpendicular to the XoZ two-dimensional plane is used as the vertical axis of the skeletal coordinate system, i.e., the Y-axis. The force lines of the 3D femur model in the XoZ two-dimensional plane are used as the vertical axis of the skeletal coordinate system, i.e., the Z-axis. Then, the cross product vector of the vertical axis and the posterior vertical axis is used as the horizontal axis of the skeletal coordinate system, i.e., the X-axis. Thus, the skeletal coordinate system of the 3D model of the femur is established. The skeletal coordinate system of the tibial 3D model is as follows. Figure 7 As shown.

[0100] Step 208: Place the implant 3D model on the skeletal 3D model in the skeletal coordinate system or image coordinate system.

[0101] The process of placing the implant 3D model in the skeletal coordinate system includes: based on the above-mentioned skeletal coordinate system, after unifying the skeletal coordinate system and the implant model coordinate system, the force line, condylar line, internal rotation, and external rotation angles calculated using the adjusted anatomical landmarks are used to automatically place or adapt the implant 3D model to the corresponding position of the skeletal 3D model.

[0102] The process of placing the implant 3D model into the skeletal unit model in the image coordinate system includes: adjusting the skeletal coordinate system to be parallel to each axis of the image coordinate system, aligning the skeletal coordinate system with the image coordinate system in the same direction, and completing the alignment of the skeletal 3D model in the image coordinate system.

[0103] Optionally, the computer device displays the 3D model of the implant and the 3D model of the skeleton in an image coordinate system. Then, a skeleton coordinate system is established based on the anatomical landmarks of the 3D model of the skeleton. However, the axes of the skeleton coordinate system may not necessarily be consistent with those of the image coordinate system. During the placement of the 3D model of the implant onto the 3D model of the skeleton, the pose of the 3D model of the implant on the 3D model of the skeleton is controlled by rotation or translation adjustment buttons on the computer device. The amount of rotation or translation of the 3D model of the implant is calculated based on the skeleton coordinate system.

[0104] In the above-described implant placement method, multiple anatomical landmarks are marked on a three-dimensional skeletal model of the anatomical structure. A skeletal coordinate system is established based on these adjusted anatomical landmarks. The implant's three-dimensional model is then placed on the skeletal model within the skeletal coordinate system or the image coordinate system. By fine-tuning the positions of the anatomical landmarks, accurate implant placement planning values ​​can be obtained. The skeletal coordinate system established based on the adjusted anatomical landmarks solves the positional error problem caused by the bone not being aligned with the image coordinate system during CT scans, resulting in more accurate implant placement parameters. This embodiment calculates the implant placement parameters through simulation, replacing manual adjustments and improving automation and intelligence.

[0105] In one embodiment, multiple anatomical landmarks on the 3D skeletal model are manually selected and confirmed. The positions of these landmarks are subject to subjective error, affecting the accuracy of implant placement. Therefore, to address this issue, this embodiment designs an algorithm to fine-tune the positions of the manually selected anatomical landmarks within a small range. By fine-tuning the positions of the anatomical landmarks on the bone, they are automatically adjusted to geometrically local extreme points to obtain accurate implant placement planning values, ensuring the accuracy of implant placement. Specifically, marking multiple anatomical landmarks on the 3D skeletal model further includes:

[0106] Centered on anatomical landmarks and within a preset cube, the voxel points of the 3D skeletal model are traversed to identify target voxel points that meet preset search conditions. These target voxel points are then used as adjusted anatomical landmarks. The preset search condition is that the vector from the anatomical landmark to the target voxel point has the largest projection length in the direction perpendicular to the vector in the skeletal coordinate system of the 3D skeletal model.

[0107] For example, the 3D skeletal model is a 3D femoral model. Anatomical landmarks include the posterior border of the greater trochanter (A), the medial posterior condyle (B), the lateral posterior condyle (C), the femoral head center (E), and the knee joint center (F). The fine-tuning method for each anatomical landmark is the same. Therefore, taking the medial posterior condyle (B) and the lateral posterior condyle (C) as examples, such as... Figure 8 As shown, for the medial tangent point B and lateral tangent point C of the posterior condyle on the 3D femoral model, a certain search range is set. For example, the search range can be set to a cube range of half the length of the line connecting the medial tangent point B and the lateral tangent point C. All voxel points B' and C' on the outer surface of the 3D femoral model within the cube range are traversed to maximize the projection length of vectors BB' and CC' on the vertical axis of the skeletal coordinate system of the 3D femoral model. That is, the voxel points B' and C' that meet the requirements are the local extreme points of the medial tangent point B and the lateral tangent point C after fine-tuning.

[0108] It should be noted that since the medial tangent point B and the lateral tangent point C of the posterior condyle are located on the coronal view of the femoral 3D model and are close to the posterior end of the femoral 3D model, the vertical axis of the skeletal coordinate system of the femoral 3D model is perpendicular to vectors BB' and CC'.

[0109] For example, the 3D skeletal model is a tibial 3D model. Anatomical landmarks include the medial proximal tibial tangent point G, the lateral proximal tibial tangent point H, the talus center point K, the tibial plateau center J, and the talus center point K. The fine-tuning method for each anatomical landmark is the same. Therefore, taking the medial proximal tibial tangent point G and the lateral proximal tibial tangent point H as examples, ... Figure 9 As shown, for the medial proximal tibial tangent point G and the lateral proximal tibial tangent point H on the tibial 3D model, a certain search range is set. For example, the search range can be set as a cube range with half the length of the line connecting the medial proximal tibial tangent point G and the lateral proximal tibial tangent point H. Traverse all voxel points G' and H' on the outer surface of the tibial 3D model within the cube range on the tibial 3D model, so that the projection length of vectors GG' and HH' in the vertical axis direction of the skeletal coordinate system of the femoral 3D model is maximized. That is, the voxel points G' and H' that meet the requirements are the local extreme points of the posterior condyle medial tangent point G and the posterior condyle lateral tangent point H after fine-tuning.

[0110] It should be noted that since the medial proximal tibial tangent point G and the lateral proximal tibial tangent point H are located on the sagittal view of the tibial 3D model and are close to the front end of the tibial 3D model, the vertical axis of the skeletal coordinate system of the tibial 3D model is perpendicular to vectors GG' and HH'.

[0111] In this embodiment, the positions of anatomical landmarks are fine-tuned within a small range. By fine-tuning the positions of the anatomical landmarks of the bones, they are automatically adjusted to the extreme points of the geometric locality to obtain accurate implant placement planning values ​​and ensure the correctness of implant placement.

[0112] In one embodiment, to establish the skeletal coordinate system of a 3D skeletal model, this embodiment determines the XoZ two-dimensional plane of the skeletal coordinate system based on three anatomical landmarks located in the coronal view. The normal vector perpendicular to the XoZ two-dimensional plane is used as the vertical axis of the skeletal coordinate system, i.e., the Y-axis. The force lines of the 3D skeletal model in the XoZ two-dimensional plane are used as the vertical axis of the skeletal coordinate system, i.e., the Z-axis. The cross product of the vertical axis and the vertical axis is used as the horizontal axis of the skeletal coordinate system, i.e., the X-axis, thus establishing the skeletal coordinate system of the 3D skeletal model. Therefore, the anatomical landmarks include at least three anatomical landmarks used to mark the protrusions on the coronal view of the 3D skeletal model, and at least two anatomical landmarks used to mark the protrusions on the sagittal view of the 3D skeletal model. Specifically, based on the adjusted anatomical landmarks, the skeletal coordinate system of the 3D skeletal model is established, such as... Figure 10 As shown, it includes the following steps:

[0113] Step 1002: Determine the normal vector of the coronal view based on at least three anatomical landmarks on the coronal view of the 3D skeletal model, and use the normal vector as the vertical axis of the skeletal coordinate system of the 3D skeletal model.

[0114] In particular, the coronal, sagittal, and transverse planes of the skeletal 3D model are oriented in the same way as the 3D images of the anatomical structures displayed in the image coordinate system.

[0115] Taking the femur as an example of a 3D skeletal model, the coronal and sagittal views of the femur 3D model, obtained according to the coronal and sagittal directions of the anatomical structures displayed in the image coordinate system, are as follows: Figure 6 As shown. The coronal view of the femur 3D model includes the femur at the posterior border of the greater trochanter (A), the medial posterior condyle (B), and the lateral posterior condyle (C). The sagittal view of the femur 3D model includes the femoral head center point (E) and the knee joint center point (F).

[0116] Taking the tibia as an example of a 3D skeletal model, the coronal and sagittal views of the 3D skeletal model, obtained according to the coronal and sagittal planes of the anatomical structure displayed in the image coordinate system, are as follows: Figure 7 As shown. The coronal view of the tibial 3D model includes the medial proximal tibial tangent point G, the lateral proximal tibial tangent point H, and the talus center point K. The sagittal view of the tibial 3D model includes the tibial plateau center J and the talus center point K.

[0117] Because anatomical landmarks are raised points on a coronal view, they are not on a straight line. For example... Figure 4 As shown, the normal vector of the coronal plane view in the image coordinate system is the vertical axis.

[0118] Taking the 3D model of the skeleton as an example, such as the 3D model of the femur. Figure 6 As shown, the coronal view of the three-dimensional femur model includes the femur with the posterior edge point A of the greater trochanter, the medial tangent point B of the posterior condyle, and the lateral tangent point C of the posterior condyle. The femur with the posterior edge point A of the greater trochanter, the medial tangent point B of the posterior condyle, and the lateral tangent point C of the posterior condyle can form a plane. The normal vector perpendicular to this plane is the vertical axis of the skeletal coordinate system of the three-dimensional femur model.

[0119] Taking the 3D model of the tibia as an example, such as... Figure 7 As shown, the coronal view of the tibial 3D model includes the medial proximal tibial tangent point G, the lateral proximal tibial tangent point H, and the talus center point K. The medial proximal tibial tangent point G, the lateral proximal tibial tangent point H, and the talus center point K can form a surface, and the normal vector perpendicular to this surface is the vertical axis of the skeletal coordinate system of the tibial 3D model.

[0120] Optionally, the computer device determines the coronal and sagittal views of the 3D skeletal model according to the coronal and sagittal directions of the anatomical structure displayed in the image coordinate system. The computer device obtains the 3D coordinates of at least three anatomical landmarks on the coronal view in the image coordinate system. Based on the three anatomical landmarks that are not on a straight line, a unique plane can be determined, and the normal vector of this plane is used as the vertical axis of the skeletal coordinate system of the 3D skeletal model.

[0121] Step 1004: Take the line vector connecting two anatomical landmarks on the sagittal view of the 3D skeletal model as the vertical axis of the skeletal coordinate system of the 3D skeletal model.

[0122] Among them, such as Figure 4 As shown, the normal vector of the sagittal plane view in the image coordinate system is the vertical axis.

[0123] Taking the 3D model of the skeleton as an example, such as the 3D model of the femur. Figure 6 As shown, the sagittal view of the three-dimensional femur model includes the femoral head center point E and the knee joint center point F. The line connecting the knee joint center point F and the femoral head center point E is the femoral force line. The vector from the knee joint center point F to the femoral head center point E is the vertical axis of the skeletal coordinate system of the three-dimensional femur model.

[0124] Taking the 3D model of the tibia as an example, such as... Figure 7 As shown, the sagittal view of the tibial 3D model includes the tibial plateau center J and the talus center point K. The line connecting the talus center point K and the tibial plateau center J is the tibial force line. The vector from the talus center point K to the tibial plateau center J is the vertical axis of the skeletal coordinate system of the tibial 3D model.

[0125] Optionally, the computer device acquires the three-dimensional coordinates of at least two anatomical landmarks in the image coordinate system on the sagittal view, and uses the line vector connecting the two anatomical landmarks on the sagittal view as the vertical axis of the skeletal coordinate system of the skeletal three-dimensional model.

[0126] Step 1006: Take the cross product vector of the vertical axis and the y-axis as the x-axis of the skeletal coordinate system of the 3D skeletal model.

[0127] Given the vertical and ordinate axes of the skeletal coordinate system, the cross product of the vertical and ordinate axes is the horizontal axis of the skeletal coordinate system.

[0128] Taking the femur as an example of a three-dimensional skeletal model, the cross product of the femoral force line and the normal vector of the coronal plane is used to determine the horizontal axis of the skeletal coordinate system.

[0129] Taking the tibial 3D model as an example, the cross product of the tibial force line and the normal vector of the coronal plane is used to determine the horizontal axis of the skeletal coordinate system.

[0130] In this embodiment, the force line direction of the three-dimensional bone model is taken as the vertical axis of the bone coordinate system, and the normal vector of the coronal view of the three-dimensional bone model is taken as the vertical axis of the bone coordinate system. The bone coordinate system of the three-dimensional bone model is established. Based on the above method of establishing the coordinate system, the implant placement error caused by the patient's position and posture not being aligned with the image coordinate system or the bone itself being tilted is reduced.

[0131] In one embodiment, if the skeletal coordinate system of the 3D skeletal model established in the above embodiment is not aligned with the image coordinate system, an angular error will occur during implant placement, resulting in inaccurate positional parameters of the implant 3D model on the skeletal 3D model. Therefore, to solve this problem, this embodiment aligns the skeletal coordinate system of the 3D skeletal model to be parallel to each axis of the image coordinate system, thus resolving the positional error problem caused by the misalignment between the skeletal coordinate system and the image coordinate system, making the positional parameters of the implant 3D model more accurate. Specifically, as shown... Figure 11 As shown, establishing the skeletal coordinate system for the 3D skeletal model based on the adjusted anatomical landmarks also includes the following steps:

[0132] Step 1102: Using any anatomical landmark as the base point, rotate the skeletal coordinate system with the cross product of the vertical axis of the skeletal coordinate system and the vertical axis of the image coordinate system as the rotation axis until the vertical axis of the skeletal coordinate system is parallel to the vertical axis of the image coordinate system.

[0133] In this system, the cross product of the vertical axes of the skeletal coordinate system and the image coordinate system is perpendicular to both. Since the vertical axes of the skeletal and image coordinate systems intersect or are parallel in the three-dimensional space where they coexist, to accommodate the positional relationship between their vertical axes in different scenarios, we can use any anatomical landmark as a base point and the cross product of their vertical axes as the rotation axis. Rotating the skeletal coordinate system will make the vectors along the vertical axis of the skeletal coordinate system parallel to the vectors along the vertical axis of the image coordinate system.

[0134] Optionally, the computer device's display interface displays the positional relationship between the skeletal coordinate system and the image coordinate system in real time. Using any anatomical landmark as a base point, and the cross product of the vertical axes of the skeletal coordinate system and the image coordinate system as the rotation axis, the skeletal coordinate system is rotated in a direction in which the vertical axis of the skeletal coordinate system is parallel to the vertical axis of the image coordinate system. During the rotation of the skeletal coordinate system, the computer device displays the angle between the vertical axis of the skeletal coordinate system and the vertical axis of the image coordinate system. When the vertical axis of the skeletal coordinate system is parallel to the vertical axis of the image coordinate system, the rotation of the skeletal coordinate system is stopped.

[0135] Step 1104: Rotate the skeletal coordinate system with the vertical axis of the image coordinate system as the rotation axis until the horizontal axis of the skeletal coordinate system is parallel to the horizontal axis of the image coordinate system.

[0136] Once the vertical axis of the skeletal coordinate system is parallel to the vertical axis of the image coordinate system, simply aligning the horizontal axis of the skeletal coordinate system with the horizontal axis of the image coordinate system, or aligning the vertical axis of the skeletal coordinate system with the vertical axis of the image coordinate system, will align the skeletal coordinate system of the 3D skeletal model with the axes of the image coordinate system.

[0137] For example, such as Figure 12 As shown, taking the femur as the 3D model of the skeleton and the knee joint center point F as the anatomical landmark, the rotation axis is the cross product of the femoral force line EF (the vertical axis of the skeletal coordinate system) and the vertical axis of the image coordinate system, using the knee joint center point F as the base point, until the femoral force line EF is parallel to the vertical axis of the image coordinate system. Then, using the knee joint center point F as the base point and the vertical axis of the image coordinate system as the rotation axis, the skeletal coordinate system is rotated until the horizontal axis of the skeletal coordinate system is parallel to the horizontal axis of the image coordinate system.

[0138] For example, such as Figure 13As shown, taking the tibial 3D model as the skeletal 3D model and the tibial plateau center J as the anatomical landmark, the rotation axis is the cross product of the tibial force line JK (the vertical axis of the skeletal coordinate system) and the vertical axis of the image coordinate system, using the tibial force line JK (the vertical axis of the skeletal coordinate system) as the base point and the vertical axis of the image coordinate system as the rotation axis, until the tibial force line JK is rotated to be parallel to the vertical axis of the image coordinate system. Then, using the tibial plateau center J as the base point and the vertical axis of the image coordinate system as the rotation axis, the skeletal coordinate system is rotated until the horizontal axis of the skeletal coordinate system is rotated to be parallel to the horizontal axis of the image coordinate system.

[0139] The algorithm for aligning the 3D skeletal model to be parallel to the axes of the image coordinate system is as follows:

[0140]

[0141] Among them, Translation 膝关节中心点 This represents a 3×3 displacement matrix composed of the position coordinates of the center point of the knee joint; This represents a 3×3 rotation matrix that rotates the X-axis of the skeleton coordinate system to be parallel to the X-axis of the image coordinate system, with the Z-axis of the image coordinate system as the rotation axis. The cross product of the Z-axis of the skeletal coordinate system and the Z-axis of the image coordinate system is represented by a rotation axis, which is a 3×3 rotation matrix that rotates the Z-axis of the skeletal coordinate system to be parallel to the Z-axis of the image coordinate system.

[0142] Optionally, the computer device's display interface displays the positional relationship between the skeletal coordinate system and the image coordinate system in real time. The skeletal coordinate system is rotated with the vertical axis of the image coordinate system as the rotation axis, and the horizontal axis of the skeletal coordinate system is parallel to the horizontal axis of the image coordinate system. During the rotation of the skeletal coordinate system, the computer device displays the angle between the horizontal axis of the skeletal coordinate system and the horizontal axis of the image coordinate system. When the horizontal axis of the skeletal coordinate system is parallel to the horizontal axis of the image coordinate system, the rotation of the skeletal coordinate system is stopped.

[0143] In this embodiment, the skeletal coordinate system of the 3D skeletal model is aligned to be parallel to each axis of the image coordinate system by means of alignment, which solves the positional error problem caused by the misalignment between the skeletal coordinate system of the 3D skeletal model and the image coordinate system, and makes the positional parameters of the implant 3D model more accurate.

[0144] In one embodiment, the traditional method of placing a 3D implant model on a 3D bone model relies primarily on manual adjustment, which suffers from large placement errors and low efficiency. Therefore, to address these issues, this embodiment utilizes implant placement parameters recommended for various implant systems to achieve automatic implant placement, improving the efficiency of 3D implant model placement and enhancing automation and intelligence. Specifically, as... Figure 14As shown, placing the implant 3D model on the skeletal 3D model in the skeletal coordinate system or image coordinate system includes the following steps:

[0145] Step 1402: Determine the dimensional values ​​of the 3D skeletal model of the anatomical structure.

[0146] Since the bone dimensions of different anatomical structures are different, when modeling the bones of anatomical structures, it is necessary to determine the bone dimensions of the anatomical structure and then model it at a 1:1 scale to obtain a three-dimensional bone model of the anatomical structure.

[0147] Optionally, the computer device obtains the three-dimensional information of the skeleton of the anatomical structure by scanning or measuring, imports the three-dimensional information of the skeleton into the computer device, and the computer device calculates the size value of the three-dimensional skeleton model, or obtains the size value of the three-dimensional skeleton model of the anatomical structure by scanning.

[0148] Step 1404: Determine the 3D model of the implant that matches the size value.

[0149] Different bone sizes require different implant sizes.

[0150] Optionally, after learning the dimensions of the 3D bone model, the computer device automatically adapts the implant model to the implant model and imports the 3D implant model corresponding to the implant model into the computer device.

[0151] Step 1406: Based on the osteotomy amount and rotation angle adapted to the implant 3D model, install the implant 3D model on the bone 3D model so that the rotation angle and osteotomy amount of the implant 3D model after installation are the same as the pre-planned rotation angle and osteotomy amount.

[0152] Different implant models have corresponding recommended osteotomy amounts and rotation angles. Therefore, after determining the implant model, the osteotomy amount and rotation angle that are compatible with the implant's three-dimensional model can be determined based on the implant model.

[0153] Optionally, the computer device calculates the real-time rotation angle of the implant's 3D model and the amount of osteotomy caused to the bone 3D model. Based on the difference between the real-time rotation angle of the implant's 3D model and the appropriate rotation angle, it determines the rotation matrix required for the implant's 3D model to reach the appropriate rotation angle. The computer device rotates the implant's 3D model according to the rotation matrix until the real-time rotation angle of the implant's 3D model reaches the appropriate rotation angle. Based on the difference between the real-time translation amount of the implant's 3D model and the appropriate amount of osteotomy, it determines the translation matrix required for the implant's 3D model to reach the appropriate amount of osteotomy. The computer device translates the implant's 3D model according to the translation matrix until the real-time translation amount of the implant's 3D model reaches the appropriate amount of osteotomy.

[0154] In this embodiment, based on the dimensions of the 3D bone model of the anatomical structure, a 3D implant model matching the dimensions is determined. Based on the osteotomy amount and rotation angle of the implant model, a rotation matrix required for the implant model to reach the matching rotation angle and a translation matrix required for the matching osteotomy amount are determined. The implant model is rotated according to the rotation matrix until its real-time rotation angle reaches the matching angle. The implant model is then translated according to the translation matrix until its real-time translation reaches the matching osteotomy amount. Using this method, the implant model can be mounted on the 3D bone model so that the rotation angle and osteotomy amount after mounting are the same as the pre-planned rotation angle and osteotomy amount, achieving automatic implant placement, improving the efficiency of implant model placement, and enhancing automation and intelligence.

[0155] In one embodiment, such as Figure 15 As shown, determining the dimensions of the 3D skeletal model includes the following steps:

[0156] Step 1502: Using the anatomical landmarks on the coronal view of the 3D skeletal model as base points, traverse the voxel points on the coronal view of the 3D skeletal model to determine the target voxel point that meets the preset conditions; the preset conditions are to maximize the projection length of the vector from the target voxel point to the anatomical landmarks in the axial direction of the skeletal coordinate system.

[0157] Here, a voxel is a pixel on the surface of the 3D skeletal model. The dimensions of the 3D skeletal model include its length and width. The implant model can be determined based on the length or width of the 3D skeletal model; therefore, in this embodiment, only the length or width of the 3D skeletal model needs to be determined. In this embodiment, the distance between the anatomical landmarks on the coronal view of the 3D skeletal model and the target voxel on the coronal view is the length of the 3D skeletal model.

[0158] For example, such as Figure 16 As shown, taking the femur as the 3D model of the skeleton and the anatomical landmarks as the finely adjusted medial posterior condyle tangent point B' or lateral posterior condyle tangent point C' as the base point, a certain search range is set, and the voxel point D on the coronal view of the 3D skeleton model is traversed to maximize the projection length of the vector DB' or DC' formed by voxel point D and B' or C' in the vertical direction of the skeleton coordinate system. That is, the magnitude of the vector DB' or DC' is set to the length value of the 3D skeleton model. The implant size corresponding to the length value is searched, and the implant size can be automatically adapted.

[0159] Step 1504: Use the magnitude of the vector from the target voxel to the anatomical landmark as the dimension value of the skeletal 3D model.

[0160] Among them, the projection length of vector DB' or DC' on the vertical axis of the skeleton coordinate system is the largest, which is the magnitude of vector DB' or DC, and is used as the bone length value of the 3D skeleton model.

[0161] In some embodiments, the dimensions of the skeletal 3D model include its length and width. The implant model can be determined based on the length or width of the skeletal 3D model. Therefore, this embodiment determines the width value of the anatomical skeletal 3D model by including the following steps:

[0162] Step 1: Using the anatomical landmarks on the sagittal view of the 3D skeletal model as base points, traverse the voxel points on the sagittal view of the 3D skeletal model to determine the first target voxel point and the second target voxel point that meet the preset conditions. The preset conditions are to maximize the projection length of the first vector from the first target voxel point to the anatomical landmark point and the second vector from the second target voxel point to the anatomical landmark point in the horizontal direction of the skeletal coordinate system.

[0163] Among them, the projection length of the first vector and the second vector on the horizontal axis of the skeleton coordinate system is the largest, which indicates that the first target voxel point and the second target voxel point are located at the leftmost point and the rightmost point of the skeleton 3D model on the horizontal axis of the skeleton coordinate system. Therefore, the distance between the first target voxel point and the second target voxel point is the width value of the skeleton 3D model.

[0164] For example, such as Figure 17As shown, taking the tibial 3D model as the skeletal 3D model and the anatomical landmark point as the finely adjusted tibial plateau center point J' as an example, the tibial plateau center point J' is used as the base point. A certain search range is set, and the voxel points on the sagittal view of the skeletal 3D model are traversed to determine the first target voxel point I and the second target voxel point L, so that the projection of vector IJ' and vector LJ' on the horizontal axis of the skeletal coordinate system is maximized. The magnitude of vector IL is set to the width value of the tibial 3D model, and the corresponding tibial implant size is searched to complete the automatic adaptation of the implant size.

[0165] Step 2: Use the vector magnitude from the first target voxel to the second target voxel as the size value of the skeletal 3D model.

[0166] In this embodiment, the voxel points on the coronal view of the 3D skeletal model are traversed to determine the target voxel point that meets the preset conditions. The preset conditions are to maximize the projection length of the vector from the target voxel point to the anatomical landmark point in the vertical direction of the skeletal coordinate system. The bone length value of the 3D skeletal model is determined by the magnitude of the vector from the target voxel point to the anatomical landmark point on the coronal view of the 3D skeletal model.

[0167] In one embodiment, the computer device performs rotation and translation operations on the implant's 3D model according to rotation and translation matrices respectively, until the real-time rotation angle of the implant's 3D model reaches the appropriate rotation angle and the real-time translation amount of the implant's 3D model reaches the appropriate osteotomy amount. Specifically, such as... Figure 18 As shown, based on the osteotomy amount and rotation angle adapted to the 3D model of the implant, the 3D model of the implant is installed on the 3D model of the bone, so that the rotation angle and osteotomy amount of the 3D model of the implant after installation are the same as the pre-planned rotation angle and osteotomy amount, including:

[0168] Step 1802: For the three-dimensional space where the implant 3D model and the bone 3D model coexist, align the implant coordinate system of the implant 3D model with the bone coordinate system of the bone 3D model to obtain the aligned implant 3D model; the vertical axis of the implant coordinate system is perpendicular to the mounting surface of the implant 3D model, the horizontal axis of the implant coordinate system is parallel to the mounting surface of the implant 3D model, and the vertical axis of the implant coordinate system is perpendicular to both the vertical and horizontal axes of the implant coordinate system.

[0169] Taking the three-dimensional model of the femur as an example, such as Figure 19 As shown, the 3D model of the implant on the 3D femoral model and the 3D femoral model are displayed in the image coordinate system. Taking the 3D model of the tibia as an example, as shown... Figure 20As shown, the implant 3D model and the tibial 3D model are displayed in the image coordinate system; the 3D space where the implant 3D model and the bone 3D model coexist can be the 3D space defined by the influencing coordinate system. Aligning the implant coordinate system of the implant 3D model with the bone coordinate system of the bone 3D model means aligning the axes of the implant coordinate system with the axes of the bone coordinate system.

[0170] In this embodiment, the mounting surface of the implant 3D model refers to the plane that contacts the bone 3D model, and is located at the bottom of the implant 3D model, such as... Figure 19 As shown, the vertical axis of the implant coordinate system is perpendicular to the mounting surface of the implant's 3D model, and the positive direction of the vertical axis points from the bottom to the top of the implant. Figure 19 As shown, the mounting surface of the implant's 3D model is approximately a rectangle. The length of the rectangle is taken as the horizontal axis of the implant's coordinate system, and the positive direction of the horizontal axis points from the inside to the outside of the implant. Figure 19 As shown, the vertical axis of the implant coordinate system is perpendicular to both the vertical and horizontal axes of the implant coordinate system, and the positive direction of the vertical axis of the implant coordinate system is from the front to the back of the implant.

[0171] Optionally, the computer device rotates the implant 3D model in the three-dimensional space where the implant 3D model and the bone 3D model coexist, using the origin of the implant coordinate system of the implant 3D model as the base point, the angle between the vertical axis of the implant coordinate system and the vertical axis of the bone coordinate system as the rotation angle, and the cross product axis of the vertical axis of the implant coordinate system and the vertical axis of the bone coordinate system as the rotation axis, until the vertical axis of the implant coordinate system is parallel to the vertical axis of the bone coordinate system, thus obtaining the aligned implant 3D model.

[0172] Step 1804: Rotate the aligned 3D model of the implant in three-dimensional space until the rotation angle of the 3D model of the implant reaches the appropriate rotation angle.

[0173] Optionally, after the implant 3D model is aligned, the computer device acquires the real-time rotation angle of the aligned implant 3D model, determines the rotation matrix required for the implant 3D model to reach the appropriate rotation angle based on the difference between the real-time rotation angle and the appropriate rotation angle, and rotates the implant 3D model according to the rotation matrix until the real-time rotation angle of the implant 3D model reaches the appropriate rotation angle.

[0174] Step 1806: Move and rotate the 3D model of the implant in 3D space, and calculate the real-time osteotomy amount caused by the 3D model of the implant to the 3D model of the skeleton during the movement until the real-time osteotomy amount reaches the appropriate osteotomy amount.

[0175] The translation process specifically includes: the computer device translates the center of the implant coordinate system of the rotated implant 3D model to the center of the bone coordinate system, moves the implant 3D model up and down along the vertical axis of the bone coordinate system, and calculates the real-time osteotomy amount caused by the implant 3D model to the bone 3D model during the up and down movement until the real-time osteotomy amount reaches the appropriate osteotomy amount.

[0176] Optionally, after the computer device acquires the 3D model of the implant and rotates it to the appropriate rotation angle, the computer acquires the real-time position coordinates of the 3D model of the implant in the image coordinate system. Based on the difference between the real-time position coordinates and the appropriate osteotomy amount, the computer determines the translation matrix required for the 3D model of the implant to reach the appropriate osteotomy amount. The computer then translates the 3D model of the implant according to the translation matrix until the real-time translation amount of the 3D model of the implant reaches the appropriate osteotomy amount.

[0177] In this embodiment, by aligning the implant coordinate system of the implant 3D model with the skeletal coordinate system, the axes of the implant coordinate system are aligned to be parallel to the axes of the skeletal coordinate system, thus obtaining an aligned implant 3D model. Based on the aligned implant 3D model, rotation and translation are performed so that the rotation angle of the implant 3D model and the amount of osteotomy caused to the skeletal 3D model are the same as the matching rotation angle and amount of osteotomy, thereby realizing automatic implant placement, improving the efficiency of implant 3D model placement, and enhancing the degree of automation and intelligence.

[0178] In one embodiment, the rotation angle includes inward / outward rotation angle, outward / inward rotation angle, and forward / backward tilt angle. Therefore, as... Figure 21 As shown, the implant's 3D model is rotated and aligned in three-dimensional space until the rotation angle of the implant's 3D model reaches the appropriate rotation angle. This process specifically includes the following steps:

[0179] Step 2102: Rotate the 3D model of the implant after it has been aligned by using the vertical axis of the skeletal coordinate system as the rotation axis and the appropriate inversion / exversion angle as the rotation angle, so as to obtain the positioning of the 3D model of the implant under the inversion / exversion angle and the implant coordinate system in the first posture.

[0180] The rotation matrix required to rotate the 3D model of the implant to the appropriate inversion / exversion angle is calculated based on the vertical axis of the skeletal coordinate system as the rotation axis and the appropriate inversion / exversion angle as the rotation angle.

[0181] Optionally, the computer device rotates the 3D implant model in the skeletal 3D model with the vertical axis of the iliac coordinate system as the rotation axis and the appropriate inversion / exversion angle as the rotation angle, thereby obtaining the positioning of the 3D implant model under the inversion / exversion angle and the implant coordinate system in the first posture.

[0182] Step 2104: Determine the condylar line of the skeletal 3D model, the projection vector of the implant coordinate system in the XOY plane in the first pose, the cross product of the projection vector and the horizontal axis of the implant coordinate system in the first pose as the rotation axis, and the appropriate internal and external rotation angles as the rotation angles, rotate the implant 3D model in the first pose to obtain the positioning of the implant 3D model under the internal and external rotation angles, and the implant coordinate system in the second pose.

[0183] In the 3D model of the skeleton, the condylar line is the line connecting the highest point of the lateral condyle and the lowest point of the medial intercondylar fossa. Taking the femur as an example, as... Figure 22 As shown, the femoral condyle line is the line connecting the medial tangent point B and the lateral tangent point C of the posterior condyle. Taking the tibia as an example, as... Figure 23 As shown, the condylar line of the tibia is the line connecting the medial tangent point G and the lateral tangent point H of the proximal tibia.

[0184] Specifically, the rotation matrix required to rotate the 3D model of the implant to the appropriate internal and external rotation angles is calculated by taking the cross product vector of the projection vector of the condylar line of the skeletal 3D model onto the XOY plane of the implant coordinate system in the first pose and the horizontal axis of the implant coordinate system in the first pose as the rotation axis, and taking the appropriate internal and external rotation angles as the rotation angles.

[0185] Optionally, the computer device determines the condylar line of the skeletal 3D model based on anatomical landmarks on the skeletal 3D model, determines the vector direction of the condylar line, and the projection vector of the condylar line with the vector direction on the XOY plane of the implant coordinate system in the first pose. The cross product vector of the projection vector and the horizontal axis of the implant coordinate system in the first pose is used as the rotation axis, and the appropriate internal and external rotation angles are used as the rotation angles. The implant 3D model in the first pose is rotated to obtain the positioning of the implant 3D model under the internal and external rotation angles, and the implant coordinate system in the second pose.

[0186] Step 2106: Rotate the implant 3D model in the second posture with the horizontal axis of the implant coordinate system in the second posture as the rotation axis and the adapted forward and backward tilt angle as the rotation angle to obtain the placement of the implant 3D model in the forward and backward tilt angle and the implant coordinate system in the third posture.

[0187] Specifically, the rotation matrix required to rotate the 3D model of the implant to the appropriate forward and backward tilt angle is calculated based on the horizontal axis of the implant coordinate system in the second posture as the rotation axis and the appropriate forward and backward tilt angle as the rotation angle.

[0188] Optionally, the computer device rotates the implant 3D model in the second posture with the horizontal axis of the implant coordinate system in the second posture as the rotation axis and the adapted forward and backward tilt angle as the rotation angle, to obtain the positioning of the implant 3D model in the forward and backward tilt angle, and the implant coordinate system in the third posture.

[0189] In this embodiment, when the suitable rotation angle includes inversion / outversion angle, rotation / inversion angle, and tilt angle, a rotation process and rotation matrix are provided to obtain the rotation of the implant 3D model to the suitable rotation angle, thereby realizing the automatic rotation of the implant 3D model and improving the placement efficiency of the implant 3D model.

[0190] In one embodiment, the implant 3D model is moved and rotated in three-dimensional space, and the real-time osteotomy amount caused by the implant 3D model to the skeletal 3D model during the movement is calculated until the real-time osteotomy amount reaches the appropriate osteotomy amount, including the following steps:

[0191] After translating the center of the mounting surface of the implant 3D model to the center of the osteotomy surface of the bone 3D model, it moves along the vertical axis of the bone coordinate system. Based on the projection distance of the line connecting the anatomical landmarks of the bone 3D model and the center of the osteotomy surface of the bone 3D model in the vertical direction of the bone coordinate system, the real-time osteotomy amount caused by the implant 3D model to the bone 3D model during the movement is determined until the real-time osteotomy amount reaches the appropriate osteotomy amount.

[0192] In this context, the osteotomy surface of the 3D bone model is the plane on which the 3D model of the implant is mounted. Taking the tibia as an example, the 3D bone model is as follows: Figure 23 As shown, the center of the osteotomy surface on the tibial 3D model is the center position P of the line connecting the medial proximal tibial incision point G and the lateral proximal tibial incision point H on the tibial 3D model.

[0193] In this embodiment, as the implant 3D model moves along the vertical axis of the skeletal coordinate system from the center of the mounting surface until the real-time osteotomy amount reaches the appropriate osteotomy amount, the translation matrix required for the real-time osteotomy amount of the implant 3D model to reach the appropriate osteotomy amount is calculated.

[0194] Osteotomy volume refers to the amount of bone removed from the 3D bone model when the implant 3D model is installed onto the 3D bone model. Taking the femur 3D model as an example, the osteotomy volume of the femur 3D model includes the medial and lateral osteotomy volume of the distal femur and the medial and lateral osteotomy volume of the posterior femur. For example, Figure 24 As shown, the calculation of the medial and lateral osteotomy amounts of the distal femur is as follows: the projection distance of the lines connecting the medial incision point M and the lateral incision point N of the distal femur to the geometric center point P1 of the distal mounting surface of the implant 3D model onto the vertical axis of the femur 3D model is the medial and lateral osteotomy amount. Figure 25 As shown, the calculation of the medial and lateral osteotomy amounts at the posterior end of the femur is as follows: the projection distance of the lines connecting the medial posterior condyle incision point B and the lateral posterior condyle incision point C to the geometric center point P2 of the posterior mounting surface of the implant 3D model onto the vertical axis of the femoral 3D model is the medial and lateral osteotomy amount. Taking the tibial 3D model as an example, the osteotomy amount of the tibial 3D model includes the medial and lateral osteotomy amounts of the proximal tibia, such as... Figure 26 As shown, the calculation of the medial and lateral osteotomy amount of the proximal tibia is as follows: the projection distance of the line connecting the center point E of the femoral head and the center point F of the knee joint to the geometric center point P3 of the distal mounting surface of the implant 3D model on the vertical axis of the tibia 3D model is the medial and lateral osteotomy amount.

[0195] After osteotomy and implant placement on the femoral and tibial 3D models, the final positioning of the implant 3D models on the femoral and tibial 3D models is as follows: Figure 27 As shown,

[0196] In this embodiment, the implant 3D model is moved and rotated in three-dimensional space. After the center of the mounting surface of the implant 3D model is translated to the center of the osteotomy surface of the bone 3D model, it moves along the vertical axis of the bone coordinate system. Based on the projection distance of the line connecting the anatomical landmarks of the bone 3D model and the center of the osteotomy surface of the bone 3D model in the vertical direction of the bone coordinate system, the real-time osteotomy amount caused by the implant 3D model to the bone 3D model during the movement is determined until the real-time osteotomy amount reaches the appropriate osteotomy amount. During this process, the translation matrix required for the real-time osteotomy amount of the implant 3D model to reach the appropriate osteotomy amount is calculated, thereby realizing the automatic translation of the implant 3D model and improving the placement efficiency of the implant 3D model.

[0197] In one embodiment, detailed steps of a method for implant placement in knee replacement surgery are provided, specifically including:

[0198] Step 1: Obtain a 3D model of the anatomical structure of the skeleton; the 3D model of the skeleton is a 3D model of the femur and / or a 3D model of the tibia.

[0199] Step 2: Mark multiple anatomical landmarks on the 3D skeletal model. Using the anatomical landmarks as the center and a preset cube as the search range, traverse the voxel points of the 3D skeletal model to determine the target voxel points that meet the preset search conditions. Use the target voxel points as the adjusted anatomical landmarks. The preset search condition is that the vector from the anatomical landmark to the target voxel point has the largest projection length in the direction perpendicular to the vector in the skeletal coordinate system of the 3D skeletal model.

[0200] Step 3: Determine the normal vector of the coronal view based on at least three anatomical landmarks on the coronal view of the 3D skeletal model, and use the normal vector as the vertical axis of the skeletal coordinate system of the 3D skeletal model.

[0201] Step 4: Use the line vector connecting two anatomical landmarks on the sagittal view of the 3D skeletal model as the vertical axis of the skeletal coordinate system of the 3D skeletal model.

[0202] Step 5: Use the cross product vector of the vertical axis and the y-axis as the x-axis of the skeletal coordinate system of the 3D skeletal model.

[0203] Step 6: Using any anatomical landmark as the base point, rotate the skeletal coordinate system with the cross product of the vertical axis of the skeletal coordinate system and the vertical axis of the image coordinate system as the rotation axis until the vertical axis of the skeletal coordinate system is parallel to the vertical axis of the image coordinate system.

[0204] Step 7: Rotate the skeletal coordinate system with the vertical axis of the image coordinate system as the rotation axis until the horizontal axis of the skeletal coordinate system is parallel to the horizontal axis of the image coordinate system.

[0205] Step 8: Using the anatomical landmarks on the coronal view of the 3D skeletal model as base points, traverse the voxel points on the coronal view of the 3D skeletal model to determine the target voxel point that meets the preset conditions. The preset conditions are to maximize the projection length of the vector from the target voxel point to the anatomical landmarks in the vertical direction of the skeletal coordinate system.

[0206] Step 9: Use the magnitude of the vector from the target voxel to the anatomical landmark as the size value of the skeletal 3D model.

[0207] Step 10: Determine the 3D model of the implant that matches the size value.

[0208] Step 11: For the three-dimensional space where the implant 3D model and the bone 3D model coexist, align the implant coordinate system of the implant 3D model with the bone coordinate system of the bone 3D model to obtain the aligned implant 3D model; the vertical axis of the implant coordinate system is perpendicular to the mounting surface of the implant 3D model, the horizontal axis of the implant coordinate system is parallel to the mounting surface of the implant 3D model, and the vertical axis of the implant coordinate system is perpendicular to both the vertical and horizontal axes of the implant coordinate system.

[0209] Step 12: Rotate the 3D model of the implant after it has been aligned by using the vertical axis of the skeletal coordinate system as the rotation axis and the appropriate inversion / exversion angle as the rotation angle, so as to obtain the positioning of the 3D model of the implant under the inversion / exversion angle and the implant coordinate system in the first posture.

[0210] Step 13: Determine the condylar line of the skeletal 3D model, the projection vector of the implant coordinate system in the first pose on the XOY plane, the cross product of the projection vector and the horizontal axis of the implant coordinate system in the first pose as the rotation axis, and the appropriate internal and external rotation angles as the rotation angles, rotate the implant 3D model in the first pose to obtain the positioning of the implant 3D model under the internal and external rotation angles, and the implant coordinate system in the second pose.

[0211] Step 14: Rotate the implant 3D model in the second posture with the horizontal axis of the implant coordinate system in the second posture as the rotation axis and the adapted forward and backward tilt angle as the rotation angle to obtain the positioning of the implant 3D model in the forward and backward tilt angle and the implant coordinate system in the third posture.

[0212] Step 15: After translating the center of the mounting surface of the implant 3D model to the center of the osteotomy surface of the bone 3D model, move it along the vertical axis of the bone coordinate system. Based on the projection distance of the line connecting the anatomical landmarks of the bone 3D model and the center of the osteotomy surface of the bone 3D model in the vertical direction of the bone coordinate system, determine the real-time osteotomy amount caused by the implant 3D model to the bone 3D model during the movement, until the real-time osteotomy amount reaches the appropriate osteotomy amount.

[0213] In this embodiment, a skeletal coordinate system is established, and each axis of the skeletal coordinate system is aligned parallel to each axis of the image coordinate system. This solves the positional error problem caused by the skeletal 3D model not necessarily being aligned with the image coordinate system, making the positional parameters of the implant 3D model more accurate. By fine-tuning the position of the anatomical landmarks of the skeletal 3D model, the anatomical landmarks are automatically adjusted to geometric local extreme points to obtain accurate implant placement planning values. The placement of the implant 3D model is automatically calculated and controlled, which, when applied to a shutdown replacement surgery robot, can improve the level of automation and intelligence.

[0214] Based on the same inventive concept, this application also provides an implant placement system for knee replacement surgery to implement the implant placement method described above. The solution provided by this system is similar to the implementation described in the above method; therefore, the specific limitations of one or more implant placement system embodiments for knee replacement surgery provided below can be found in the limitations of the implant placement method described above, and will not be repeated here.

[0215] In one embodiment, an implant placement system for knee replacement surgery is provided, the implant placement system for knee replacement surgery includes a robotic device, surgical manipulation tools, and processing circuitry.

[0216] Surgical instruments are mounted on a robotic device; the robotic device is used to guide the surgical instruments to place the implant onto the anatomical structure.

[0217] The processing circuitry is configured to: acquire a three-dimensional model of the anatomical structure of the skeleton; the three-dimensional model of the skeleton is a three-dimensional model of the femur and / or the tibia;

[0218] Multiple anatomical landmarks are marked on the 3D skeletal model; the positions of the anatomical landmarks are adjusted to obtain the adjusted anatomical landmarks;

[0219] Based on the adjusted anatomical landmarks, establish the skeletal coordinate system of the three-dimensional skeletal model;

[0220] Place the implant 3D model on the skeletal 3D model in the skeletal coordinate system or image coordinate system.

[0221] In one embodiment, the processing circuitry is further configured to generate a control object based on the placement of the implant, and to control the robotic device to confine the surgical instruments within the control object.

[0222] In one instance, the processing circuitry is also configured to generate a control object based on the placement of the implant and to control the robotic device to confine the surgical instruments within the control object.

[0223] In this context, the control object refers to the parameters used to define the placement and orientation of the implant on the 3D model of the skeleton. For example, the control object can be parameters such as the amount of osteotomy and the rotation angle.

[0224] In one embodiment, the processing circuitry is further configured to implement the steps in the above method embodiments.

[0225] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0226] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0227] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0228] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data shall comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0229] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0230] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0231] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A computer-readable storage medium having stored thereon a computer program, characterized in that, When the computer program is executed by the processor, it performs the following steps: Obtain a three-dimensional model of the anatomical structure of the skeleton; the three-dimensional model of the skeleton is a three-dimensional model of the femur and / or a three-dimensional model of the tibia; Multiple anatomical landmarks are marked on the three-dimensional skeletal model, and the positions of the anatomical landmarks are adjusted to obtain the adjusted anatomical landmarks. The step of adjusting the position of the anatomical landmark to obtain the adjusted anatomical landmark includes: taking the anatomical landmark as the center and a preset cube as the search range, traversing the voxel points of the 3D skeletal model, determining the target voxel point that meets the preset search conditions, and using the target voxel point as the adjusted anatomical landmark; the preset search conditions are that the vector from the anatomical landmark to the target voxel point has the largest projection length in the direction perpendicular to the vector in the skeletal coordinate system of the 3D skeletal model. Based on the adjusted anatomical landmarks, establish the skeletal coordinate system of the three-dimensional skeletal model; The implant 3D model is placed on the bone 3D model in the bone coordinate system or image coordinate system; the rotation angle and osteotomy amount of the implant 3D model after installation are the same as the matching rotation angle and osteotomy amount.

2. The computer-readable storage medium of claim 1, wherein, The anatomical landmarks include at least three anatomical landmarks for marking the coronal view of the three-dimensional skeletal model, and at least two anatomical landmarks for marking the protrusions on the sagittal view of the three-dimensional skeletal model. The step of establishing the skeletal coordinate system of the three-dimensional skeletal model based on the adjusted anatomical landmarks includes: Based on at least three anatomical landmarks on the coronal view of the three-dimensional skeletal model, the normal vector of the coronal view is determined, and the normal vector is used as the vertical axis of the skeletal coordinate system of the three-dimensional skeletal model. The line vector connecting two anatomical landmarks on the sagittal view of the 3D skeletal model is taken as the vertical axis of the skeletal coordinate system of the 3D skeletal model. The cross product vector of the vertical axis and the longitudinal axis is used as the horizontal axis of the skeletal coordinate system of the skeletal 3D model.

3. The computer-readable storage medium of claim 2, wherein, The step of establishing the skeletal coordinate system of the three-dimensional skeletal model based on the adjusted anatomical landmarks further includes: Using any of the anatomical landmarks as a base point, and the cross product of the vertical axis of the skeletal coordinate system and the vertical axis of the image coordinate system as the rotation axis, rotate the skeletal coordinate system until the vertical axis of the skeletal coordinate system is parallel to the vertical axis of the image coordinate system. Rotate the skeletal coordinate system around the vertical axis of the image coordinate system until the horizontal axis of the skeletal coordinate system is parallel to the horizontal axis of the image coordinate system.

4. The computer-readable storage medium of claim 1, wherein, Placing the implant 3D model on the skeletal 3D model in the skeletal coordinate system or image coordinate system includes: Determine the dimensions of the skeletal 3D model; Based on the stated dimensions, determine a three-dimensional model of the implant that matches the stated dimensions; Based on the osteotomy amount and rotation angle adapted to the implant 3D model, the implant 3D model is matched to the bone 3D model so that the rotation angle and osteotomy amount of the implant 3D model after installation are the same as the adapted rotation angle and osteotomy amount.

5. The computer-readable storage medium of claim 4, wherein, Determining the dimensions of the skeletal 3D model includes: Using the anatomical landmarks on the coronal view of the 3D bone model as base points, the voxel points on the coronal view of the 3D bone model are traversed to determine the target voxel point that meets the preset conditions; the preset conditions are to maximize the projection length of the vector from the target voxel point to the anatomical landmarks in the axial direction of the bone coordinate system. The magnitude of the vector from the target voxel point to the anatomical landmark point is used as the size value of the skeletal 3D model.

6. The computer-readable storage medium of claim 4, wherein, The step of mounting the 3D implant model onto the 3D bone model according to the osteotomy amount and rotation angle adapted to the 3D implant model, so that the rotation angle and osteotomy amount of the 3D implant model after installation are the same as the adapted rotation angle and osteotomy amount, includes: For the three-dimensional space where the implant 3D model and the bone 3D model coexist, the implant coordinate system of the implant 3D model is aligned with the bone coordinate system of the bone 3D model to obtain the aligned implant 3D model; the vertical axis of the implant coordinate system is perpendicular to the mounting surface of the implant 3D model, the horizontal axis of the implant coordinate system is parallel to the mounting surface of the implant 3D model, and the vertical axis of the implant coordinate system is perpendicular to both the vertical axis and the horizontal axis of the implant coordinate system. The implant 3D model is rotated and aligned in the 3D space until the rotation angle of the implant 3D model reaches the appropriate rotation angle. The implant 3D model is moved and rotated in the 3D space, and the real-time osteotomy amount caused by the implant 3D model to the skeletal 3D model during the movement is calculated until the real-time osteotomy amount reaches the appropriate osteotomy amount.

7. The computer-readable storage medium of claim 6, wherein, The rotation angle includes inversion / exversion angle, external rotation angle, and forward / backward tilt angle. The process of rotating and aligning the implant 3D model in the three-dimensional space until the rotation angle of the implant 3D model reaches the appropriate rotation angle includes: Using the vertical axis of the skeletal coordinate system as the rotation axis and the pre-planned inversion / exversion angle as the rotation angle, the three-dimensional model of the implant after rotation and alignment is obtained to achieve the positioning of the three-dimensional model of the implant under the inversion / exversion angle and the implant coordinate system in the first posture. The condylar line of the skeletal 3D model is determined, and its projection vector on the XOY plane of the implant coordinate system in the first pose is used as the cross product vector of the projection vector and the horizontal axis of the implant coordinate system in the first pose as the rotation axis. The implant 3D model in the first pose is rotated with a pre-planned internal and external rotation angle as the rotation angle to obtain the positioning of the implant 3D model under the internal and external rotation angle, and the implant coordinate system in the second pose. Using the horizontal axis of the implant coordinate system in the second posture as the rotation axis and the pre-planned forward and backward tilt angle as the rotation angle, rotate the implant 3D model in the second posture to obtain the placement of the implant 3D model under the forward and backward tilt angle, and the implant coordinate system in the third posture.

8. The computer-readable storage medium of claim 6, wherein, The process of moving and rotating the implant 3D model in the three-dimensional space, calculating the real-time osteotomy amount caused by the implant 3D model to the skeletal 3D model during the movement, until the real-time osteotomy amount reaches the appropriate osteotomy amount, includes: After translating the center of the mounting surface of the implant 3D model to the center of the osteotomy surface of the bone 3D model, it moves along the vertical axis of the bone coordinate system. Based on the projection distance of the line connecting the anatomical landmarks of the bone 3D model and the center of the osteotomy surface of the bone 3D model in the vertical direction of the bone coordinate system, the real-time osteotomy amount caused by the implant 3D model to the bone 3D model during the movement is determined until the real-time osteotomy amount reaches the appropriate osteotomy amount.

9. An implant placement system for knee replacement surgery, characterized in that, The system includes robotic devices, surgical instruments, and processing circuitry. The surgical instrument is mounted on the robotic device; the robotic device is used to guide the surgical instrument to place the implant onto the anatomical structure. The processing circuit is configured as follows: Obtain a three-dimensional model of the anatomical structure of the skeleton, wherein the three-dimensional model of the skeleton is a three-dimensional model of the femur and / or the tibia. Multiple anatomical landmarks were marked on the three-dimensional skeletal model; The positions of the anatomical landmarks are adjusted to obtain the adjusted anatomical landmarks; The step of adjusting the position of the anatomical landmark to obtain the adjusted anatomical landmark includes: taking the anatomical landmark as the center and a preset cube as the search range, traversing the voxel points of the 3D skeletal model, determining the target voxel point that meets the preset search conditions, and using the target voxel point as the adjusted anatomical landmark; the preset search conditions are that the vector from the anatomical landmark to the target voxel point has the largest projection length in the direction perpendicular to the vector in the skeletal coordinate system of the 3D skeletal model. Based on the adjusted anatomical landmarks, establish the skeletal coordinate system of the three-dimensional skeletal model; The implant 3D model is placed on the bone 3D model in the bone coordinate system or image coordinate system; the rotation angle and osteotomy amount of the implant 3D model after installation are the same as the matching rotation angle and osteotomy amount.

10. The system according to claim 9, characterized in that, The processing circuit is further configured to: A control object is generated based on the placement of the implant, and the robotic device is controlled to confine the surgical instruments within the control object.

11. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method implemented by the computer-readable storage medium according to any one of claims 1 to 8.

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