Navigation system and method for shoulder joint replacement surgery

Abstract

The present application relates to the technical field of computers. Provided are a navigation system and method for shoulder joint replacement surgery. The system comprises a controller and a navigation and positioning apparatus, wherein the controller is in communication connection with the navigation positioning apparatus; and the controller comprises a preoperative planning module, a preoperative simulation module and an intraoperative execution module.

Description

Navigation systems and methods for shoulder replacement surgery

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application No. 202411928583.4, filed on December 25, 2024, entitled “Shoulder Joint Replacement Surgery Navigation System and Method”, which is incorporated herein by reference in its entirety. Technical Field

[0003] This application relates to the field of computer technology, and in particular to a shoulder joint replacement surgery navigation system and method. Background Technology

[0004] Shoulder replacement surgery is an effective treatment for severe shoulder pain and dysfunction, suitable for conditions such as shoulder arthritis, shoulder fractures, and rotator cuff tears. Types of shoulder replacement surgery typically include hemiarthroplasty, total shoulder replacement, and reverse total shoulder replacement, each tailored to different pathological conditions and patient needs. The main procedure involves removing the damaged joint surface (osteotomy) and implanting an artificial prosthesis to reduce pain and restore shoulder joint function.

[0005] In related technologies, before performing shoulder replacement surgery, it is difficult to accurately and objectively select the prosthesis with the highest compatibility with the affected bone based on the individual characteristics of the affected bone. It is also difficult to accurately simulate and evaluate whether the installation position of the prosthesis and the range of motion of the patient's shoulder joint are within a reasonable range after implantation. This increases the risk of long-term pain, shoulder joint instability, and prosthesis loosening or dislocation after surgery.

[0006] Therefore, how to more accurately and objectively select a prosthesis that fits the affected bone before shoulder replacement surgery, and how to more accurately simulate and evaluate whether the installation position of the prosthesis and the range of motion of the patient's shoulder joint are within a reasonable range after implantation, are the technical problems to be solved in this field. Summary of the Invention

[0007] This application provides a shoulder replacement surgery navigation system and method to address the shortcomings of existing technologies, such as the difficulty in accurately and objectively selecting a prosthesis that fits the affected bone before shoulder replacement surgery, and the difficulty in accurately simulating and evaluating the installation position of the prosthesis and whether the patient's shoulder joint range of motion is within a reasonable range after implantation. This system enables more accurate and objective selection of a prosthesis that fits the affected bone before shoulder replacement surgery, and more accurate simulation and evaluation of the installation position of the prosthesis and whether the patient's shoulder joint range of motion is within a reasonable range after implantation.

[0008] This application provides a shoulder joint replacement surgery navigation system, a controller, and a navigation and positioning device; the controller is communicatively connected to the navigation and positioning device; the controller includes a preoperative planning module, a preoperative simulation module, and an intraoperative execution module.

[0009] The preoperative planning module is used to generate a three-dimensional bone model of the patient's affected bone based on the first image and the second image, and to perform prosthesis planning based on the three-dimensional bone model of the affected bone to obtain parameter information of the prosthesis to be implanted in the affected bone. The first image includes a medical image of the affected bone before shoulder joint replacement surgery, and the second image includes a medical image of the healthy bone corresponding to the affected bone. The affected bone and the healthy bone corresponding to the affected bone are symmetrically distributed with the spine as the midline. The parameter information includes size, posture information and installation position information.

[0010] The preoperative simulation module is used to simulate the range of motion of the patient's shoulder joint on the surgical side after the prosthesis is implanted into the affected bone, based on the parameter information of the prosthesis to be implanted, and to obtain the maximum range of motion of the patient's shoulder joint on the surgical side.

[0011] The intraoperative execution module is used to control the navigation and positioning device to perform surgical navigation in the shoulder joint replacement surgery targeting the affected bone, based on the parameter information of the prosthesis to be implanted, when it is determined that the maximum range of motion of the patient's operated shoulder joint is greater than the range of motion threshold.

[0012] The navigation and positioning device is used to perform surgical navigation in response to the control of the intraoperative execution module during shoulder replacement surgery for the affected bone.

[0013] This application also provides a shoulder joint replacement surgery navigation method based on any of the shoulder joint replacement surgery navigation systems described above, including:

[0014] Based on the first and second images, a three-dimensional bone model of the patient's affected bone is generated. Based on the three-dimensional bone model of the affected bone, prosthesis planning is performed to obtain parameter information of the prosthesis to be implanted in the affected bone. The first image includes a medical image of the affected bone before shoulder joint replacement surgery. The second image includes a medical image of the healthy bone corresponding to the affected bone. The affected bone and the healthy bone corresponding to the affected bone are symmetrically distributed with the spine as the midline. The parameter information includes size, posture information and installation position information.

[0015] Based on the parameter information of the prosthesis to be implanted, the range of motion of the patient's shoulder joint on the operated side after the prosthesis to be implanted into the affected bone is simulated to obtain the maximum range of motion of the patient's shoulder joint on the operated side.

[0016] If the maximum range of motion of the patient's shoulder joint on the operated side is determined to be greater than the range of motion threshold, the navigation and positioning device is controlled to perform surgical navigation in the shoulder joint replacement surgery targeting the affected bone based on the parameter information of the prosthesis to be implanted.

[0017] The shoulder replacement surgery navigation system and method provided in this application generate a three-dimensional bone model of the affected bone by combining preoperative medical images of the affected bone and medical images of the corresponding healthy bone. This model can more accurately reflect the healthy morphology of the affected bone even when bone defects and / or morphological abnormalities exist. Based on this three-dimensional bone model, prosthesis planning can be performed, obtaining parameter information of the prosthesis to be implanted. This makes preoperative surgical planning more objective and quantitative. Based on the parameter information of the prosthesis to be implanted, the system can simulate the range of motion of the patient's shoulder joint on the operated side after implantation, obtaining the maximum range of motion angle of the patient's shoulder joint on the operated side. If the maximum range of motion angle of the patient's shoulder joint is greater than a threshold, the system controls the navigation and positioning device to perform surgical navigation during shoulder replacement surgery based on the parameter information of the prosthesis to be implanted. This further improves the accuracy and rationality of prosthesis planning, reduces surgical complications and postoperative recovery time, significantly improves the accuracy and reliability of orthopedic surgery, effectively reduces surgical risks, and achieves more stable surgical results. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 is one of the structural schematic diagrams of the shoulder joint replacement surgery navigation system provided in this application.

[0020] Figure 2 is one of the schematic cross-sectional views of the shoulder joint.

[0021] Figure 3 is the second cross-sectional view of the shoulder joint.

[0022] Figure 4 is the third cross-sectional view of the shoulder joint.

[0023] Figure 5 is a three-dimensional bone model of the patient's surgical shoulder joint in the shoulder replacement surgery navigation system provided in this application.

[0024] Figure 6 is a schematic diagram of the prosthesis planning and preoperative simulation process of the shoulder joint replacement surgery navigation system provided in this application.

[0025] Figure 7 is a second schematic diagram of the shoulder joint replacement surgery navigation system provided in this application.

[0026] Figure 8 is a flowchart illustrating the shoulder joint replacement surgery navigation method provided in this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] In the description of the invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0029] In the description of this application, the terms "first," "second," etc., are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, without limiting the number of objects; for example, a first object can be one or more. Furthermore, in the description of this application, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects have an "or" relationship.

[0030] It should be noted that surgical navigation is a visual image-guided surgical technique developed using medical images such as ultrasound, X-rays, CT (computed tomography), and MRI (magnetic resonance imaging) as the basis, and with the help of computers, precision instruments, and image processing technology. Surgical navigation can track the position of surgical instruments in real time through three-dimensional digitization of the patient's lesion tissue, realizing the visualization and automation of surgical procedures, thereby assisting doctors or robots to complete surgical tasks more quickly, accurately, and safely.

[0031] Shoulder replacement surgery is an orthopedic procedure used to treat severe shoulder pain and dysfunction. It is typically performed on patients experiencing persistent pain and limited function due to conditions such as arthritis of the shoulder, shoulder fractures, rotator cuff tears, or other conditions that damage the shoulder joint.

[0032] Artificial shoulder arthroplasty includes hemiarthroplasty, total shoulder arthroplasty, and reverse total shoulder arthroplasty. Hemiarthroplasty is primarily used for arthritis involving the humeral head and osteonecrosis not involving the labrum, as well as severe proximal humeral fractures. Total shoulder arthroplasty is mainly used for osteoarthritis, inflammatory arthritis, osteonecrosis involving the labrum, and postmenopausal degenerative joint diseases. Reverse total shoulder arthroplasty is primarily used for patients with osteoarthritis and complex humeral fractures. The indications for reverse total shoulder arthroplasty, unlike total and hemiarthroplasty, mainly include severe rotator cuff tears or loss but with intact biceps brachii function. Because of its better patient recovery and lower revision rate compared to total shoulder arthroplasty, it is currently the most widely used shoulder arthroplasty procedure.

[0033] Shoulder replacement surgery involves removing the damaged joint surface (osteotomy) and implanting an artificial prosthesis to replace the damaged joint, thereby reducing pain and restoring joint function.

[0034] The general procedure for shoulder surgery includes preoperative examination (such as medical imaging), surgical approach, dislocation of the humeral head, osteotomy and medullary canal expansion, prosthesis installation, rotator cuff repair, and postoperative evaluation.

[0035] Among the surgical procedures, osteotomy and prosthesis placement are the most critical. Factors such as the amount of bone removed, the angle of the osteotomy plane, the location of the prosthesis mounting holes, and the fit of the prosthesis implantation surface directly affect the success of the surgery. Improper prosthesis placement or poor implantation technique can lead to postoperative pain, joint instability, dislocation, or prosthesis loosening. Therefore, achieving high-quality osteotomy and prosthesis placement is a core clinical requirement for surgeons. If personalized surgical planning can be developed preoperatively, appropriate prostheses can be selected, joint range of motion can be simulated, and navigation technology can be used during osteotomy to assist surgeons in completing the preoperative planning, improving the accuracy of osteotomy and prosthesis placement, postoperative complications can be reduced, thereby improving the quality of the surgery. Furthermore, preoperative planning can predict the accuracy and stability of prosthesis placement, adjust the range of motion of the joint, and plan postoperative rehabilitation, thus enhancing surgical outcomes.

[0036] Traditional surgical navigation systems in related technologies are mainly suitable for trauma surgeries of the pelvis, hip, and limbs, full-segment spinal surgeries, and hip and knee joint replacement surgeries. Surgical navigation systems specifically for shoulder joint replacement surgery are not yet widely available in related technologies.

[0037] In related technologies, the main drawbacks of shoulder replacement surgery for surgeons are as follows: First, before performing shoulder replacement surgery, surgeons can only plan the surgical procedure based on subjective experience and medical images of the affected bone taken before the operation. When planning the surgical procedure based on subjective experience, surgeons are limited to qualitatively analyzing whether the patient's affected bone is suitable for surgery. It is difficult to accurately, objectively, and quantitatively plan the size of the osteotomy, the size of the implanted prosthesis, and the optimal placement of the prosthesis based on the individual characteristics of the affected bone.

[0038] In particular, during shoulder replacement surgery, doctors often lack objective and quantitative preoperative surgical planning, leading them to rely solely on subjective experience. This results in unstable surgical outcomes, increased surgical risks, and negative impacts on postoperative recovery and the final outcome for the patient.

[0039] Furthermore, the bones are obscured by surrounding tissues such as muscles, blood vessels, and nerves, making it difficult for doctors to accurately determine the entire shape of the affected bone with the naked eye. In cases where the patient's affected bone has bone defects or abnormal shapes, doctors also find it difficult to accurately determine the degree of bone defects or abnormal bone shapes through visual observation. This may lead to errors in surgical procedures, affecting the precision and safety of the surgery.

[0040] Furthermore, after prosthesis planning, there is a lack of effective simulation methods to simulate and assess whether the installation position of the prosthesis and the patient's shoulder joint range of motion are within a reasonable range after implantation. This makes it impossible to accurately assess whether the installation position of the prosthesis and the patient's shoulder joint range of motion are within a reasonable range, increasing the risk of long-term pain, shoulder joint instability, and prosthesis loosening or dislocation after surgery.

[0041] Finally, due to the limited space in the shoulder joint area and the thinness of the scapula, the accuracy and stability requirements for prosthesis implantation in shoulder replacement surgery are high. For example, in reverse shoulder replacement surgery, screws are needed for abutment installation. However, because the glenoid bone is too thin, if the affected bone cannot be accurately aligned and guided during surgery, the screws may penetrate the glenoid, leading to surgical failure. Furthermore, traditional surgical navigation systems in related technologies are insufficient to guide surgeons in accurately and stably implanting the prosthesis.

[0042] In response, this application provides a shoulder joint replacement surgery navigation system and method. The shoulder joint replacement surgery navigation system provided by this application can perform personalized prosthesis planning and surgical plan formulation based on medical images of the affected bone before shoulder joint replacement surgery. It can also simulate and evaluate the prosthesis placement and the patient's shoulder joint range of motion after implantation to more accurately assess whether it is within a reasonable range. This improves the accuracy and stability of prosthesis implantation during shoulder joint replacement surgery, thereby enhancing the precision, stability, and safety of the surgery, while also reducing surgical time and intraoperative radiation exposure.

[0043] The shoulder replacement surgery navigation system provided in this application offers a precise, stable, and safe surgical aid. It can simulate and evaluate the patient's joint mobility after prosthesis implantation, resulting in more accurate prosthesis model and planning position. It enables rapid implantation of prostheses such as central screws, reduces radiation dose in traditional surgery, and can automatically identify unexpected patient displacements and use a following strategy to complete target tracking, further ensuring the accuracy and safety of the surgery. It can significantly improve the outcome of shoulder replacement surgery, reduce postoperative complications, and accelerate the patient's recovery process.

[0044] The shoulder joint replacement surgery navigation system provided in this application is described below with reference to Figures 1-7.

[0045] Figure 1 is one of the structural schematic diagrams of the shoulder joint replacement surgery navigation system provided in this application. The shoulder joint replacement surgery navigation system provided in this application is described below with reference to Figure 1. As shown in Figure 1, the shoulder joint replacement surgery navigation system 1000 includes: a controller 1100 and a navigation and positioning device 2000; the controller 1100 is communicatively connected to the navigation and positioning device 2000; the controller 1100 includes a preoperative planning module 104, a preoperative simulation module 105, and an intraoperative execution module 106.

[0046] The preoperative planning module 104 is used to generate a three-dimensional bone model of the patient's affected bone based on the first image and the second image, and to perform prosthesis planning based on the three-dimensional bone model of the affected bone to obtain parameter information of the prosthesis to be implanted in the affected bone. The first image includes a medical image of the affected bone before shoulder joint replacement surgery, and the second image includes a medical image of the healthy bone corresponding to the affected bone. The affected bone and the healthy bone corresponding to the affected bone are symmetrically distributed with the spine as the midline. The parameter information includes size, posture information and installation position information.

[0047] The preoperative simulation module 105 is used to simulate the range of motion of the patient's shoulder joint on the operated side after the prosthesis is implanted into the affected bone, based on the parameter information of the prosthesis to be implanted, and to obtain the maximum range of motion of the patient's shoulder joint on the operated side.

[0048] The intraoperative execution module 106 is used to control the navigation and positioning device 2000 to perform surgical navigation in shoulder replacement surgery targeting the affected bone, based on the parameter information of the prosthesis to be implanted, when it is determined that the maximum range of motion of the patient's shoulder joint on the operated side is greater than the range of motion threshold.

[0049] The navigation and positioning device 2000 is used to perform surgical navigation in response to the control of the intraoperative execution module 106 during shoulder replacement surgery for the affected bone.

[0050] It should be noted that the controller 1100 in this embodiment can be configured in electronic devices such as computers and servers.

[0051] Specifically, the shoulder replacement surgery system provided in this application can provide surgical navigation for the surgeon performing the shoulder replacement surgery before and during the surgery, thereby improving the accuracy, safety and efficiency of the shoulder replacement surgery.

[0052] It is understandable that, in order to maintain the body's balance and stability, the human skeleton is symmetrically distributed with the spine as the midline. Normally, the bones in the human shoulder are also symmetrically distributed with the spine as the midline.

[0053] In this embodiment, the affected bone and healthy bone are symmetrically distributed with the spine as the midline. The affected bone is the bone on the surgical side that requires shoulder replacement surgery, and the healthy bone is the bone on the healthy side that corresponds to the affected bone and does not require shoulder replacement surgery. The surgical side is the side of the body that requires shoulder replacement surgery, and the healthy side is the side of the body that does not require shoulder replacement surgery.

[0054] When a patient's affected bone has bone defects and / or morphological abnormalities, it is difficult to generate a complete and accurate three-dimensional bone model based solely on the image of the affected bone. Therefore, in this embodiment, the image of the patient's healthy side is used for mapping, which can generate a complete and accurate three-dimensional bone model and bony landmarks of the affected bone, thereby improving the accuracy of preoperative surgical planning.

[0055] It is understood that the patient and the affected bone in the embodiments of this application can be determined based on actual needs. The embodiments of this application do not impose specific limitations on the patient and the affected bone.

[0056] Optionally, the affected bone in the aforementioned patients may include at least one of the scapula, humerus, or clavicle.

[0057] Before performing shoulder joint replacement surgery on the patient's affected bone, the preoperative planning module 104 can acquire medical images of the patient's affected bone as the first image and medical images of the healthy bone corresponding to the affected bone as the second image.

[0058] It should be noted that the medical images of the affected bone and healthy bone in the embodiments of this application may include, but are not limited to, medical images such as X-ray images, CT images and MRI images of the affected bone and healthy bone.

[0059] It is understood that medical images such as X-ray images, CT images, and MRI images follow standardized patient positioning, fixed imaging equipment, image reconstruction and localization methods, and standardized reports and markings. Therefore, the orientation of the affected bone in these medical images is relatively fixed. In this embodiment, the horizontal direction in the above medical images can be defined as the X-axis direction, and the vertical direction in the above medical images can be defined as the Y-axis direction.

[0060] In this embodiment, the preoperative planning module 104 can acquire medical images of the patient's affected bone and the corresponding healthy bone in various ways before shoulder joint replacement surgery. For example, the preoperative planning module 104 can acquire medical images of the patient's affected bone and the corresponding healthy bone through data query; or, the preoperative planning module 104 can acquire medical images of the patient's affected bone and the corresponding healthy bone based on user input. This embodiment does not limit the specific method for acquiring the medical images of the patient's affected bone and the corresponding healthy bone.

[0061] After the preoperative planning module 104 acquires medical images of the patient's affected bone and the corresponding healthy bone, it can determine the medical image of the affected bone as the first image and the medical image of the corresponding healthy bone as the second image. Then, based on the first and second images, the preoperative planning module 104 can generate a three-dimensional bone model of the affected bone through data calculation, mathematical statistics, or deep learning techniques.

[0062] As an optional embodiment, the preoperative planning module 104 includes a data import unit, an image processing unit, and a prosthesis planning unit.

[0063] The data import unit is used to acquire the first image and the second image, and sends the first image and the second image to the image processing unit if the image quality of the first image and the second image meets the preset standard.

[0064] The image processing unit is used to construct a first 3D point cloud model based on a first image, and a second 3D point cloud model based on a second image. It extracts the centroids of the first and second 3D point cloud models, and mirrors the second 3D point cloud model horizontally based on the centroids of the first and second 3D point cloud models to obtain a third 3D point cloud model. It aligns the first and third 3D point cloud models based on their centroids, obtains the feature descriptor for each point in the third 3D point cloud model, and then uses a consistent initial registration algorithm to perform coarse point cloud registration between the third and first 3D point cloud models based on the feature descriptors of each point in the third 3D point cloud model, obtaining a fourth 3D point cloud model. Finally, it uses an iterative nearest point algorithm and singular value decomposition to perform fine point cloud registration between the fourth and first 3D point cloud models, obtaining a 3D bone model of the affected bone.

[0065] The prosthesis planning unit is used to obtain the bony information of the affected bone based on the three-dimensional bone model, and then to plan the prosthesis based on the bony information of the affected bone to obtain the parameter information of the prosthesis to be implanted.

[0066] Specifically, before performing shoulder joint replacement surgery on the affected bone, the data import unit can acquire medical images of the patient's affected bone and the corresponding healthy bone through various methods. For example, the data import unit can acquire medical images of the patient's affected bone and the corresponding healthy bone through data query; or, the data import unit can acquire medical images of the patient's affected bone and the corresponding healthy bone based on user input. This application embodiment does not limit the specific method by which the data import unit acquires medical images of the patient's affected bone and the corresponding healthy bone.

[0067] It should be noted that, given the poor image quality of the first image, it is difficult to generate a 3D point cloud model based on it. Therefore, the data import unit in this embodiment can set preset standards based on prior knowledge and / or actual conditions, and check the first and second images based on these preset standards to determine whether their image quality meets the preset standards.

[0068] If the data import unit determines that the image quality of the first image and the second image meets the preset standard, it can determine that the image quality of the first image and the second image can meet the requirements for generating a three-dimensional point cloud model, and then send the first image and the second image to the image processing unit.

[0069] After receiving the first and second images sent by the data import unit, the image processing unit can construct a first three-dimensional point cloud model based on the first image and a second three-dimensional point cloud model based on the second image using methods such as numerical calculation, mathematical statistics, and deep learning.

[0070] As an optional embodiment, the image processing unit is specifically used to preprocess the first image to obtain a preprocessed first image when the image quality of the first image meets a preset standard. Based on the distribution of bone fragments of the affected bone, the preprocessed first image is segmented to obtain multiple sub-images corresponding to the first image. Each sub-image includes only one bone fragment of the affected bone. The sub-image of the largest bone fragment of the affected bone is determined as the target sub-image. Then, based on the target sub-image, a three-dimensional point cloud model of the largest bone fragment of the affected bone is constructed as the first three-dimensional point cloud model.

[0071] Specifically, the image processing unit can perform data preprocessing on the first image to further improve its image quality. This data preprocessing may include image denoising, contrast enhancement, and image sharpening.

[0072] It should be noted that, considering the possibility of bone fracture, after preprocessing the first image, the image processing unit can segment the first image to obtain multiple sub-images corresponding to the first image. Each sub-image corresponding to the first image includes only one bone fragment from the affected bone.

[0073] After the image processing unit acquires each sub-image corresponding to the first image, it can determine the sub-image including the largest bone fragment in the affected bone as the target sub-image, and then generate a three-dimensional point cloud model of the largest bone fragment in the affected bone based on the target sub-image, as the first three-dimensional point cloud model.

[0074] It should be noted that, in this embodiment, the image processing unit can utilize the Marching Cubes (MC) algorithm to generate a three-dimensional point cloud model of the largest bone fragment in the affected bone based on the aforementioned target sub-image, serving as the first three-dimensional point cloud model. In this embodiment, the image processing unit can also utilize the aforementioned Marching Cubes algorithm to generate a three-dimensional point cloud model of the healthy bone corresponding to the affected bone based on the second image, serving as the second three-dimensional point cloud model.

[0075] The moving cube algorithm is a well-established algorithm for extracting isosurfaces. Its basic idea is to process cubes (voxels) in the data field one by one, separating the cubes that intersect with the isosurfaces, and using interpolation to calculate the intersection points of the isosurfaces with the cube edges. Based on the relative position of each vertex of the cube to the isosurface, the intersection points of the isosurfaces with the cube edges are connected in a certain way to generate an isosurface, which serves as an approximate representation of the isosurface within the cube. This is because the moving cube algorithm has a fundamental assumption: the data field along the edges of the hexahedron changes continuously. That is, if two vertices of an edge are greater than or less than the value of the isosurface, then there is one and only one point on that edge that is the intersection point of the edge and the isosurface.

[0076] The image processing unit in this embodiment can ensure that the image clarity, contrast, etc. meet the preset standards for subsequent analysis or modeling by preprocessing the first image, which helps to reduce analysis errors caused by poor image quality. By determining the sub-image containing the largest bone block of the affected bone as the target sub-image and constructing a three-dimensional point cloud model based on the sub-image, the possibility of bone fracture in the affected bone can be fully considered, providing a more accurate data basis for generating a three-dimensional bone model of the affected bone.

[0077] In this embodiment, S can be used to represent the first three-dimensional point cloud model, and D can be used to represent the second three-dimensional point cloud model.

[0078] After the image processing unit constructs the first 3D point cloud model S and the second 3D point cloud model D, the centroid P of the first 3D point cloud model S can be extracted. c1 The centroid P of the second 3D point cloud model D c2 .

[0079] The position information of the centroid of a 3D point cloud model can be calculated using the following formula:

[0080] Among them, P c This represents the position information of the centroid of a 3D point cloud model; r i This represents the position information of the i-th point in the 3D point cloud model; n represents the number of points in the 3D point cloud model; m i The mass of the i-th point in the 3D point cloud model is represented by m in this embodiment. i The value of is 1; i represents a positive integer greater than zero.

[0081] It should be noted that in the embodiments of this application, coordinate values ​​can be used to represent the position information of any point in the three-dimensional point cloud model, or coordinate values ​​can be used to represent the position information of the centroid of the three-dimensional point cloud model.

[0082] The image processing unit acquires the centroid P of the first 3D point cloud model S. c1The centroid P of the second 3D point cloud model D c2 Then, the centroid P of the second 3D point cloud model D can be used as a basis. c2 The coordinates of each point in the second 3D point cloud model D are mirrored and flipped horizontally to obtain the third 3D point cloud model Q1.

[0083] The position information of the i-th point in the third 3D point cloud model Q1 can be represented by the following formula: T1(x i )=2*P c2 [0]-x i

[0084] Where, x i P represents the position information of the i-th point in the second 3D point cloud model D. c2 [0] represents the centroid P of the second three-dimensional point cloud model D. c2 Location information; T1(x i ) represents the position information of the i-th point in the second 3D point cloud model D after a horizontal mirror flip, which is the position information of the i-th point in the third 3D point cloud model Q1; T1={T1(x1),T1(x2),…,T1(x... i ),…,T1(x I )}, where I represents the number of points in the second three-dimensional point cloud model D.

[0085] After the image processing unit acquires the third 3D point cloud model Q1, it can proceed according to... Translate the aforementioned third 3D point cloud model Q1 to align the third 3D point cloud model Q1 with the first 3D point cloud model S.

[0086] It should be noted that SPFH (Simplified Point Feature Histograms) feature vectors are a feature representation method used to describe the local geometric relationships of each point in a point cloud. The dimension of an SPFH feature vector is 33. SPFH features are generated by calculating the geometric relationships between a point and its neighbors. An SPFH feature vector consists of three angle histograms: the angle between the normal vector of the point and the normal vector of its neighbors, the angle between the normal vector of the point and the line connecting the two points, and the angle between the normal vector of the neighboring point and the line connecting the two points.

[0087] FPFH (Fast Point Feature Histograms) feature vectors are a type of feature descriptor widely used in point cloud processing.

[0088] For the p-th point in the third 3D point cloud model Q1, the image processing unit can calculate the SPFH feature vector of the p-th point in the third 3D point cloud model Q1 through numerical calculation. Here, p represents a positive integer greater than zero.

[0089] After the image processing unit obtains the SPFH feature vector of the p-th point in the third 3D point cloud model Q1, it can obtain the FPFH feature vector of the p-th point in the third 3D point cloud model Q1 by weighted summing of the SPFH features of the neighboring points of the p-th point in the third 3D point cloud model Q1. The specific calculation formula is as follows:

[0090] Where FPFH(p) represents the FPFH feature vector of the p-th point in the third 3D point cloud model Q1; SPFH(p) represents the SPFH feature vector of the p-th point in the third 3D point cloud model Q1; p j SPFH(p) represents the j-th neighboring point of the p-th point in the third 3D point cloud model Q1; j ) represents the j-th neighbor point p of the p-th point in the third 3D point cloud model Q1. j SPFH feature vectors;

[0091] d(p,p j ) represents the p-th point and its j-th neighboring point p in the third 3D point cloud model Q1. j The distance between them; j represents a positive integer greater than zero; J represents the total number of neighborhood points of the p-th point in the third 3D point cloud model Q1.

[0092] After the image processing unit obtains the FPFH feature vector FPFH(p) of the p-th point in the third 3D point cloud model Q1, it can determine the FPFH feature vector FPFH(p) of the p-th point in the third 3D point cloud model Q1 as the feature descriptor of the p-th point in the third 3D point cloud model Q1.

[0093] After the image processing unit obtains the feature descriptor of the p-th point in the third 3D point cloud model Q1, it can use the Sample Consensus Initial Alignment (SAC-IA) algorithm to coarsely register the point clouds of the third 3D point cloud model Q1 and the first 3D point cloud model S. The specific steps include: selecting K sampling points from the third 3D point cloud model Q1, where K represents a positive integer greater than zero. To ensure that the sampling points selected from the third 3D point cloud model Q1 have different FPFH features, in this embodiment, the distance between any two sampling points selected by the image processing unit from the third 3D point cloud model Q1 is greater than a predefined distance threshold d.

[0094] For the k-th sampling point in the third 3D point cloud model Q1, the image processing unit can, based on the feature descriptor FPFH(k) of the k-th sampling point in the third 3D point cloud model Q1, determine one or more points in the first 3D point cloud model S that have similar FPFH features to the k-th sampling point in the third 3D point cloud model Q1 as similar points to the k-th sampling point in the third 3D point cloud model Q1. Specifically, if the Euclidean distance between the FPFH feature of any point in the first 3D point cloud model S and the feature descriptor FPFH(k) of the k-th sampling point in the third 3D point cloud model Q1 is less than a preset value, it can be determined that any point in the first 3D point cloud model S has similar FPFH features to the k-th sampling point in the third 3D point cloud model Q1.

[0095] When there is only one similar point corresponding to the k-th sampling point in the third 3D point cloud model Q1, the image processing unit can determine the similar point corresponding to the k-th sampling point in the third 3D point cloud model Q1 as the associated point corresponding to the k-th sampling point in the third 3D point cloud model Q1; when there are multiple similar points corresponding to the k-th sampling point in the third 3D point cloud model Q1, the image processing unit can determine any one of the similar points corresponding to the k-th sampling point in the third 3D point cloud model Q1 as the associated point corresponding to the k-th sampling point in the third 3D point cloud model Q1.

[0096] After the image processing unit determines the associated point corresponding to the k-th sampling point in the third 3D point cloud model Q1, it can calculate the rigid transformation matrix between the k-th sampling point and its associated point. Then, by solving the distance error sum function, the matching degree between the k-th sampling point and its associated point in the third 3D point cloud model Q1 can be obtained. A higher matching degree indicates a higher degree of matching between the k-th sampling point and its associated point in the third 3D point cloud model Q1.

[0097] It should be noted that the distance error and function in the embodiments of this application can be represented by the Huber penalty function, denoted as . in:

[0098] Where, m k Indicates a predefined threshold; l kThis represents the distance difference between the k-th sampling point in the third 3D point cloud model Q1 and the diameter of the associated point corresponding to the k-th sampling point in the third 3D point cloud model Q1.

[0099] The image processing unit can find an optimal transformation T3 that minimizes the Huber penalty function by coarsely registering the point clouds of the third 3D point cloud model Q1 and the first 3D point cloud model S. The optimal transformation T3 can be obtained using a gradient-based optimization algorithm.

[0100] The image processing unit transforms the third 3D point cloud model Q1 according to the optimal transformation T3 to obtain the fourth 3D point cloud model Q2.

[0101] After the image processing unit acquires the fourth 3D point cloud model Q2, it can use the Iterative Closest Point (ICP) algorithm to perform fine point cloud registration between the fourth 3D point cloud model Q2 and the first 3D point cloud model S. The specific steps include: using an initial transformation T = [R, t] to transform all points in the fourth 3D point cloud model Q2 to the first 3D point cloud model S, and defining the following energy function:

[0102] Where func represents the energy function value; s i The transformation parameter q represents the closest point in point cloud S after the transformation of the i-th point in the fourth 3D point cloud model Q2; R represents the first transformation parameter; t represents the second transformation parameter; q i This represents the i-th point in the fourth 3D point cloud model Q2.

[0103] It should be noted that the optimization objective of the energy function in this embodiment is to minimize the energy function value func.

[0104] The Singular Value Decomposition (SVD) algorithm is used to obtain the optimal solutions for the first transformation parameter R and the second transformation parameter t, resulting in transformation T4. In this embodiment, the optimal solutions for the first transformation parameter R and the second transformation parameter t are the values ​​of the first transformation parameter R and the second transformation parameter t that minimize the value of func. The specific method for obtaining transformation T4 based on the optimal solutions for the first transformation parameter R and the second transformation parameter t is as follows: the top-left 3x3 matrix is ​​transformed to represent the optimal solution for the first transformation parameter R, the right-hand 3x1 matrix to represent the optimal solution for the second transformation parameter t, and the bottom row is padded with 0, 0, 0, 1 to obtain transformation T4.

[0105] Transform the fourth 3D point cloud model Q2 according to the optimal transformation T4 to obtain the 3D bone model of the affected bone.

[0106] Transformation from the second 3D point cloud model D to the first 3D point cloud model S

[0107] In this embodiment, the image processing unit constructs a first 3D point cloud model based on a first image and a second 3D point cloud model based on a second image. Then, it extracts the centroids of the first and second 3D point cloud models and mirrors the second 3D point cloud model horizontally based on these centroids to obtain a third 3D point cloud model. This achieves symmetrical processing of the second 3D point cloud model. A consistent initial registration algorithm is used to perform coarse point cloud registration between the first and third 3D point cloud models, resulting in a fourth 3D point cloud model. This quickly establishes the initial correspondence between the first and third 3D point cloud models, helping to narrow the calculation range for subsequent fine registration and improve registration efficiency. By iteratively optimizing the transformation relationship between the first and fourth 3D point cloud models, the error between them can be gradually reduced, ultimately achieving accurate registration between the first and second 3D point cloud models and obtaining a 3D bone model of the affected bone. This provides a more accurate data foundation for subsequent surgical planning and intraoperative surgical navigation for the affected bone.

[0108] Upon receiving the three-dimensional bone model of the affected bone from the image processing unit, the prosthesis planning unit can obtain the parameter information of the prosthesis to be implanted based on the three-dimensional bone model of the affected bone through numerical calculation, mathematical statistics, and deep learning techniques.

[0109] As an optional embodiment, when the affected bone is the scapula, the prosthesis planning unit is specifically used to perform spatial correction on the three-dimensional bone model of the affected bone. After obtaining the spatially corrected three-dimensional bone model, the bony information of the affected bone is calculated based on the spatially corrected three-dimensional bone model. Based on the bony information of the affected bone, the size and posture information of the prosthesis to be implanted are obtained. Based on the size and posture information of the prosthesis to be implanted, the installation position information of the prosthesis to be implanted is obtained using an invasiveness optimization algorithm. Then, the size, posture information, and installation position information of the prosthesis to be implanted are determined as the parameter information of the prosthesis to be implanted.

[0110] The bony information of the affected bone includes the positional information of the superior, inferior, anterior, and posterior edges of the glenoid cavity, the normal of the glenoid plane, and the original posterior and superior tilt angles of the glenoid cavity. The normal of the glenoid plane is the direction from the glenoid plane of the affected bone to the normal of the humerus connected to the glenoid cavity. The glenoid plane of the affected bone is obtained by fitting the superior, inferior, anterior, and posterior edges of the glenoid cavity. The original posterior tilt angle of the glenoid cavity is the angle between the projection line of the normal of the glenoid plane in the transverse section of the affected bone and the target auxiliary line of the affected bone. The original superior tilt angle of the glenoid cavity is the angle between the projection line of the normal of the glenoid plane in the coronal section of the affected bone and the target auxiliary line of the affected bone. The target auxiliary line is the line connecting the innermost point of the scapula and the center point of the glenoid cavity of the scapula.

[0111] Figure 2 is one of the cross-sectional schematic diagrams of the shoulder joint. Figure 3 is another cross-sectional schematic diagram of the shoulder joint. Figure 4 is a third cross-sectional schematic diagram of the shoulder joint. When the affected bone is the scapula, the shape of the affected bone and its connection with other bones are shown in Figures 2 to 4.

[0112] To eliminate the influence of the patient's posture on prosthesis planning when medical images of the affected bone are taken, the prosthesis planning unit can first perform spatial correction on the three-dimensional bone model of the affected bone after receiving it from the image processing unit.

[0113] The specific method for the prosthesis planning unit to perform spatial correction of the three-dimensional bone model of the affected bone includes: taking the center point of the glenoid cavity of the affected bone as the rotation center, rotating the target auxiliary line of the affected bone (Friedman line, i.e., the line connecting the innermost point of the scapula and the center point of the glenoid cavity of the scapula) to be parallel to the horizontal direction (X-axis direction), and then rotating the three-dimensional bone model of the affected bone around the rotated Friedman line, so that when the lower edge point of the affected bone and the target auxiliary line of the affected bone are located in the standard coronal plane (i.e., the XOZ plane), the spatial correction of the three-dimensional bone model of the affected bone is completed, and the spatially corrected three-dimensional bone model of the affected bone is obtained.

[0114] After obtaining the spatially corrected three-dimensional bone model of the affected bone, the prosthesis planning unit can calculate the bony information of the affected bone based on the spatially corrected three-dimensional bone model.

[0115] It should be noted that the transverse and coronal views used in this application are medical terms. A transverse view, also known as a horizontal or axial view, refers to a cross-section parallel to the ground, dividing the human body into superior (cranial) and inferior (caudal) parts. A coronal view refers to the body position when the person is standing, based on the anterior-posterior position of the body; it is also known as a frontal or frontal view.

[0116] After obtaining the bony information of the affected bone, the prosthesis planning unit can obtain the vertical length h of the glenoid cavity of the affected bone, based on the position information of the upper and lower poles of the glenoid cavity, which is the distance (P). 上极 ,P 下极 Furthermore, based on the positions of the anterior and posterior edges of the glenoid cavity of the affected bone, the anteroposterior length w of the glenoid cavity can be obtained as distance(P). 前缘 ,P 后缘 ), where P 上极 This indicates the positional information of the superior pole of the glenoid fossa of the affected bone; P 下极 This indicates the location information of the lower pole of the glenoid cavity of the affected bone; P 前缘 This indicates the positional information of the anterior margin of the glenoid fossa of the affected bone; P 后缘 This indicates the positional information of the posterior margin of the glenoid fossa of the affected bone.

[0117] After the prosthesis planning unit obtains the vertical length h and the anterior-posterior length w of the glenoid cavity of the affected bone, it can select a prosthesis from the available prostheses whose vertical length and anterior-posterior length are both smaller than the vertical length h and anterior-posterior length w of the glenoid cavity of the affected bone as the target prosthesis. Then, the target prosthesis with the largest vertical length and anterior-posterior length among the target prostheses can be determined as the prosthesis to be implanted into the affected bone.

[0118] As an optional embodiment, the prosthesis planning unit is specifically used to determine the original posterior tilt angle and original superior tilt angle of the glenoid cavity of the affected bone as the posture information of the prosthesis to be implanted. Based on the size and posture information of the prosthesis to be implanted, a three-dimensional model of the prosthesis to be implanted is constructed. The nearest distance between any point on the base plane of the three-dimensional model of the prosthesis to be implanted and the three-dimensional bone model of the affected bone is defined as the invasive amount corresponding to any point. Based on the predefined ideal range of invasive amount, the invasive amount score corresponding to each position is calculated when the three-dimensional model of the prosthesis to be implanted is within the installation range of the three-dimensional bone model of the affected bone. Then, the position with the highest invasive amount score within the installation range of the three-dimensional bone model of the affected bone is determined as the installation position of the prosthesis to be implanted, thereby obtaining the installation position information of the prosthesis to be implanted. The installation range of the three-dimensional bone model of the affected bone is determined based on the upper pole, lower pole, anterior edge, and posterior edge of the glenoid cavity of the affected bone.

[0119] It should be noted that in related technologies, doctors typically use a 0° posterior tilt angle and a -5° (or -5° lateral tilt angle) as the initial angles for prosthesis planning. Unlike related technologies, in this embodiment, the prosthesis planning unit determines the original posterior tilt angle and lateral tilt angle of the affected bone as the posture information of the prosthesis to be implanted.

[0120] After the prosthesis planning unit obtains the size and pose information of the prosthesis to be implanted, it can obtain the installation position information of the prosthesis to be implanted by using the intrusion amount optimization algorithm based on the size and pose information of the prosthesis to be implanted. The specific steps are as follows: The prosthesis planning unit can define the shortest distance between any point on the base plane of the prosthesis to be implanted and the bone surface as the intrusion amount corresponding to the above-mentioned arbitrary point. When any point on the base plane of the prosthesis to be implanted is outside the bone surface, the intrusion amount corresponding to the above-mentioned arbitrary point is greater than 0. When any point on the base plane of the prosthesis to be implanted is inside the bone surface, the value of the intrusion amount corresponding to the above-mentioned arbitrary point is less than 0. Among them, the intrusion amount can be used to represent the relationship between the prosthesis and the bone surface.

[0121] Considering the firm combination of the prosthesis to be implanted and the bone surface, the intrusion amount corresponding to the points on the base plane of the prosthesis to be implanted should be made as small as possible and the proportion of the points with the corresponding intrusion value less than 0 should be increased. However, considering the clinical principle of minimizing bone resection to protect the diseased bone, the intrusion value cannot be made too small (for example, intrusion amounts of -4mm and -6mm mean excessive bone resection). Therefore, in the embodiment of the present application, the prosthesis planning unit determines the ideal range of the intrusion amount to be (-2, 0) based on the above principle, and then defines the intrusion score score as follows:

[0122] Among them, Num(-2 < contact < 0) represents the number of points whose corresponding intrusion amount is within the range of (-2, 0), and Num(All point) represents the total number of points.

[0123] Based on the size and pose information of the prosthesis to be implanted, the prosthesis planning unit can construct a three-dimensional model of the prosthesis to be implanted.

[0124] After the prosthesis planning unit constructs the three-dimensional model of the prosthesis to be implanted, it can control the three-dimensional model of the prosthesis to be implanted to move within the installation range in the three-dimensional bone model of the diseased bone, and based on the intrusion score at each position within the installation range of the three-dimensional model of the prosthesis to be implanted in the three-dimensional bone model of the diseased bone, it can then determine the position with the highest intrusion score within the installation range in the three-dimensional bone model of the diseased bone as the installation position of the prosthesis to be implanted, and obtain the installation position information of the prosthesis to be implanted.

[0125] It should be noted that the installation range in the three-dimensional bone model of the diseased bone is determined based on the upper pole, lower pole, anterior edge, and posterior edge of the glenoid cavity of the diseased bone.

[0126] It should be noted that the prosthesis planning unit in this embodiment also has the functions of selecting surgical procedure, prosthesis series, prosthesis model and position, and manual adjustment. It can adjust the installation position and posture of the prosthesis to be implanted in two-dimensional slices (coronal, sagittal and transverse) and three-dimensional space. The prosthesis planning unit can calculate the angle of the prosthesis to be implanted in real time (such as posterior tilt angle, superior tilt angle, humeral stem anteversion angle and neck-shaft angle, etc.) and simultaneously calculate the displacement after the affected bone is reduced, providing a basis for doctors to manually adjust the prosthesis planning.

[0127] After obtaining the parameter information of the prosthesis to be implanted, the prosthesis planning unit can send the parameter information of the prosthesis to be implanted to the preoperative simulation module 105.

[0128] As an optional embodiment, the preoperative simulation module 105 is specifically used to generate a three-dimensional bone model of the patient's shoulder joint on the surgical side after the implanted prosthesis is implanted into the affected bone, based on the parameter information of the prosthesis to be implanted. When the posture of the three-dimensional bone model of the patient's shoulder joint on the surgical side is a preset posture, the humerus in the three-dimensional bone model of the patient's shoulder joint on the surgical side is rotated in each preset direction until the humerus in the three-dimensional bone model of the patient's shoulder joint on the surgical side collides with the scapula in the three-dimensional bone model of the patient's shoulder joint on the surgical side. The rotation angle of the humerus in the three-dimensional bone model of the patient's shoulder joint on the surgical side at the time of the collision is determined as the maximum range of motion of the three-dimensional bone model of the patient's shoulder joint on the surgical side in each preset direction.

[0129] The intraoperative execution module 106 is used to send the maximum range of motion of the three-dimensional bone model of the patient's operated shoulder joint in any preset direction to the prosthesis planning unit when it is determined that the maximum range of motion of the three-dimensional bone model of the patient's operated shoulder joint in any preset direction is not greater than the range of motion threshold corresponding to any preset direction. The prosthesis planning unit updates the parameter information of the prosthesis to be implanted based on the maximum range of motion of the three-dimensional bone model of the patient's operated shoulder joint in any preset direction. When it is determined that the maximum range of motion of the three-dimensional bone model of the patient's operated shoulder joint in each preset direction is greater than the range of motion threshold corresponding to each preset direction, the navigation and positioning device 2000 controls the surgical navigation of the shoulder joint replacement surgery for the affected bone based on the parameter information of the prosthesis to be implanted.

[0130] Specifically, when the preoperative simulation module 105 receives the parameter information of the prosthesis to be implanted, it can generate a three-dimensional bone model of the shoulder joint on the surgical side of the affected bone after the prosthesis to be implanted is implanted into the affected bone, based on the parameter information of the prosthesis to be implanted, the three-dimensional bone model of the affected bone, and the first and second images, according to the prosthesis matching principle.

[0131] Figure 5 shows a three-dimensional bone model of the patient's surgical shoulder joint in the shoulder replacement surgery navigation system provided in this application. The three-dimensional bone model of the surgical shoulder joint after the prosthesis to be implanted is shown in Figure 5.

[0132] It should be noted that the orange structure in Figure 5 represents the prosthesis implanted in the scapula, and the green structure represents the prosthesis implanted in the humerus.

[0133] It should be noted that, in the embodiments of this application, the neutral position can be determined as a preset posture. Here, the neutral position is defined as having the flexion angle, backflexion angle, internal rotation angle, and external rotation angle of the shoulder joint all at 0°, and the abduction angle and adduction angle of the shoulder joint as the abduction angle and adduction angle of the shoulder joint in its natural state.

[0134] If the posture of the three-dimensional bone model of the shoulder joint on the affected side is not the preset posture mentioned above, the preoperative simulation module 105 may need to adjust the posture of the three-dimensional bone model of the shoulder joint on the affected side to the preset posture.

[0135] It should be noted that in this embodiment, the standard coronal plane (i.e., the XOZ plane) is determined by the Friedman line of the scapula on the patient's surgical side and the lowest point of the lower edge of the scapula on the patient's surgical side. The standard coordinate system corresponding to the scapula on the patient's surgical side is established with the Friedman line of the scapula on the patient's surgical side as the X-axis.

[0136] After transforming the humeral axis (the line connecting the center point of the proximal medullary canal of the humerus and the center point of the distal medullary canal of the humerus) extracted from the first image to the standard coordinate system corresponding to the scapula on the patient's side, the transformed humeral axis is projected onto the XOZ plane in the standard coordinate system corresponding to the scapula on the patient's side. The angle between the axis of this projection and the Z-axis of the standard coordinate system is the initial abduction / adduction angle of the shoulder joint on the patient's side.

[0137] In this embodiment, each preset direction and the corresponding activity angle threshold can be determined based on prior knowledge and / or actual conditions. This embodiment does not specifically limit each preset direction or the corresponding activity angle threshold.

[0138] Optionally, the preset directions in this embodiment may include a forward flexion direction, a backward flexion direction, an abduction direction, an adduction direction, an internal rotation direction, and an external rotation direction. The activity angle threshold corresponding to the forward flexion direction is 120°, the activity angle threshold corresponding to the backward flexion direction is 60°, the activity angle threshold corresponding to the abduction direction is 120°, the activity angle threshold corresponding to the adduction direction is 50°, the activity angle threshold corresponding to the internal rotation direction is 90°, and the activity angle threshold corresponding to the external rotation direction is 90°.

[0139] Understandably, when the posture of the three-dimensional bone model of the patient's shoulder joint on the operated side is the preset posture, the rotation angle of the humerus in the three-dimensional bone model of the patient's shoulder joint on the operated side is 0°.

[0140] When the posture of the three-dimensional bone model of the patient's surgical shoulder joint is in the preset posture, the preoperative simulation module 105 can rotate the humerus in the three-dimensional bone model of the patient's surgical shoulder joint in each preset direction, with each rotation angle being 1°, and determine whether the humerus in the three-dimensional bone model of the patient's surgical shoulder joint collides with the scapula in the three-dimensional bone model of the patient's surgical shoulder joint.

[0141] If the preoperative simulation module 105 determines that the humerus in the three-dimensional bone model of the patient's operated shoulder joint collides with the scapula in the three-dimensional bone model of the patient's operated shoulder joint, the rotation angle of the humerus in the three-dimensional bone model of the patient's operated shoulder joint at the time of the collision can be determined as the maximum range of motion of the three-dimensional bone model of the patient's operated shoulder joint in each preset direction.

[0142] Figure 6 is a schematic diagram of the prosthesis planning and preoperative simulation of the shoulder joint replacement surgery navigation system provided in this application. As shown in Figure 6, after the preoperative simulation module 105 obtains the maximum range of motion of the three-dimensional bone model of the patient's operated shoulder joint in each preset direction, it can send the maximum range of motion of the three-dimensional bone model of the patient's operated shoulder joint in each preset direction to the intraoperative execution module 106.

[0143] If the intraoperative execution module 106 determines that the maximum range of motion of the three-dimensional bone model of the patient's surgical shoulder joint in any preset direction is not greater than the range of motion threshold corresponding to the preset direction, and determines that the parameter information of the prosthesis to be implanted has failed the evaluation, it can send the maximum range of motion of the three-dimensional bone model of the patient's surgical shoulder joint in the preset direction to the prosthesis planning unit.

[0144] When the prosthesis planning unit receives the maximum range of motion of the three-dimensional bone model of the patient's surgical shoulder joint in the preset direction sent by the preoperative simulation module 105, it can adjust at least one of the size, posture and installation position of the bone to be implanted based on the maximum range of motion of the three-dimensional bone model of the patient's surgical shoulder joint in the preset direction, to obtain updated parameter information of the prosthesis to be implanted, and then transmit the updated parameter information of the prosthesis to be implanted to the preoperative simulation module 105 again.

[0145] When the intraoperative execution module 106 determines that the maximum range of motion of the three-dimensional bone model of the patient's shoulder joint on the surgical side is greater than the range of motion threshold corresponding to each preset direction, it determines the parameter information of the prosthesis to be implanted. Through evaluation, it can control the navigation and positioning device 2000 to perform surgical navigation in the shoulder joint replacement surgery for the affected bone based on the parameter information of the prosthesis to be implanted.

[0146] This application embodiment achieves precise planning and execution of shoulder joint replacement surgery through the synergistic effect of the preoperative simulation module and the intraoperative execution module, thereby improving surgical outcomes, optimizing patient rehabilitation, reducing surgical risks and complications, and increasing surgical efficiency and patient satisfaction.

[0147] As an optional embodiment, the intraoperative execution module is also used to determine several bony landmarks at the proximal end of the three-dimensional bone model and several bony landmarks at the distal end of the three-dimensional bone model. Then, in the shoulder replacement surgery for the affected bone, based on the correspondence between each bony landmark on the three-dimensional bone model and each bony landmark on the affected bone, the affected bone and the three-dimensional bone model are registered to establish a mapping relationship between the affected bone and the three-dimensional bone model and / or the first image. Based on the parameter information of the prosthesis to be implanted and the mapping relationship, the navigation and positioning device 2000 is controlled to perform surgical navigation in the shoulder replacement surgery for the affected bone, with the proximal end being the end closer to the incision and the distal end being the end farther from the incision.

[0148] Specifically, after receiving the three-dimensional bone model of the affected bone sent by the preoperative planning module 104, the intraoperative execution module 106 can also determine multiple bony landmarks on the three-dimensional bone model of the affected bone. Among them, bony landmarks refer to bones in certain parts of the human body that often form obvious bulges or depressions, and are often used clinically for positioning and other applications, thus becoming bony landmarks; in this embodiment of the application, bony landmarks can be determined on the three-dimensional bone model of the affected bone using an interactive picking method.

[0149] It should be noted that an incision, in orthopedic surgery, refers to the skin and tissue structures cut open to expose the surgical site and perform surgical procedures. The specific location of the incision can be determined based on the first imaging.

[0150] It should be noted that after the intraoperative execution module 106 determines multiple bony landmarks on the three-dimensional bone model of the affected bone, it can send the three-dimensional bone model of the affected bone marked with each bony landmark to the preoperative planning module 104. The preoperative planning module 104 can determine the planning scheme for different surgical procedures of the affected bone based on the three-dimensional bone model of the affected bone marked with each bony landmark. It can also provide the offset of the humerus on the surgical side relative to the preoperative side and relative to the contralateral side, and adjust the prosthesis planning according to the offset.

[0151] After the intraoperative execution module 106 determines multiple bony landmarks on the three-dimensional bone model of the affected bone, it can send the three-dimensional bone model of the affected bone marked with each bony landmark to the human-computer interaction device so that the human-computer interaction device can display the three-dimensional bone model of the affected bone marked with each bony landmark.

[0152] During orthopedic surgery on a affected bone, doctors can use probes and other devices to determine the bony landmarks on the affected bone based on the three-dimensional bone model of the affected bone, the bony landmarks on the three-dimensional bone model, and the prompts displayed on the human-computer interaction device. This establishes a correspondence between the bony landmarks on the three-dimensional bone model of the affected bone and the bony landmarks on the affected bone.

[0153] For example, in cases where bony landmarks include the medial epicondyle and lateral epicondyle of the distal humerus, a probe can be used to locate these bony landmarks on the affected bone without puncturing the patient's skin.

[0154] After establishing the correspondence between the bony landmarks on the three-dimensional bone model of the affected bone and the bony landmarks on the affected bone, the intraoperative execution module 106 can register the affected bone and the three-dimensional bone model of the affected bone based on the correspondence between the bony landmarks on the three-dimensional bone model of the affected bone and the bony landmarks on the affected bone, and establish the mapping relationship between the affected bone and the three-dimensional bone model of the affected bone and / or the first image.

[0155] As an optional embodiment, the intraoperative execution module 106 is specifically used to establish a first registration coordinate system corresponding to the affected bone based on the positional relationship between each bony landmark on the affected bone, establish a second registration coordinate system corresponding to the three-dimensional bone model based on the positional relationship between each bony landmark on the three-dimensional bone model, establish a representation matrix of the first registration coordinate system and a representation matrix of the second registration coordinate system, calculate a transformation matrix between the representation matrices of the first registration coordinate system and the second registration coordinate system as the target transformation matrix, and perform spatial transformation on each bony landmark on the affected bone based on the target transformation matrix to obtain the first... A first spatial point set is obtained by calculating a first transformation matrix based on the bony landmarks on the affected bone using a normal distribution transformation algorithm. The first spatial point set is then spatially transformed based on the first transformation matrix to obtain a second spatial point set. The second spatial point set and the bony landmarks on the three-dimensional bone model are then registered using the iterative nearest point algorithm and singular value decomposition to obtain a first registration matrix that describes the mapping relationship between the affected bone and the three-dimensional bone model. Based on the mapping relationship between the three-dimensional bone model and the first image and the first registration matrix, a second registration matrix that describes the mapping relationship between the affected bone and the first image is obtained.

[0156] It should be noted that the relevant techniques use a point-pair registration algorithm to register two 3D models, that is, to calculate the registration matrix based on 4-6 corresponding points on the two 3D models. However, for the registration of the affected bone and its 3D bone model, the determination of bony landmarks on the affected bone is easily affected by factors such as the patient's soft tissue and cartilage, resulting in inaccurate determination of the bony landmarks. Furthermore, the limited surgical area that can be operated on the affected bone leads to a relatively large error in the registration of the affected bone and its 3D bone model based on the aforementioned registration algorithm.

[0157] In response, this application provides an improved registration method. The intraoperative execution module 106 in this application performs two registrations on the affected bone and its three-dimensional bone model by establishing a registration coordinate system.

[0158] In this embodiment, the intraoperative execution module 106 can establish a first registration coordinate system corresponding to the affected bone based on the positional relationship between bony landmarks on the affected bone and through mathematical methods, and establish a second registration coordinate system corresponding to the three-dimensional bone model based on the positional relationship between bony landmarks on the three-dimensional bone model and through mathematical methods.

[0159] It is understood that the methods for establishing the first registration coordinate system corresponding to the affected bone and the second registration coordinate system corresponding to the three-dimensional bone model are the same in the embodiments of this application.

[0160] It should be noted that the bony landmarks on the affected bone include two bony landmarks located on the medial and lateral sides of the proximal end of the affected bone, and two bony landmarks located on the medial and lateral sides of the distal end of the affected bone.

[0161] Taking the humerus as the affected bone as an example, the bony landmarks on the affected bone include bony landmark 1 and bony landmark 2 located on both sides of the proximal end of the humerus, as well as bony landmark A located on the medial epicondyle of the humerus and bony landmark B located on the lateral epicondyle of the humerus.

[0162] The bony landmarks on the three-dimensional bone model of the affected bone include bony landmarks 1 and 2 located on both sides of the proximal end of the three-dimensional bone model of the humerus, as well as bony landmark A located on the medial epicondyle of the three-dimensional bone model of the humerus and bony landmark B located on the lateral epicondyle of the three-dimensional bone model of the humerus.

[0163] The vector pointing from bony landmark A located on the medial epicondyle of the humerus to bony landmark B located on the lateral epicondyle of the humerus The X-axis of the first registration coordinate system is defined by the midpoint of the line connecting bony landmark 1 and bony landmark 2 located on both sides of the proximal end of the humerus. The plane AOB is defined by the origin O of the first registration coordinate system and the bony landmark A located on the medial epicondyle of the humerus pointing to the bony landmark B located on the lateral epicondyle of the humerus. The direction that passes through the origin O of the first registration coordinate system and is perpendicular to the plane AOB upward is defined as the Y-axis of the first registration coordinate system. Thus, the first registration coordinate system can be obtained.

[0164] Similarly, the vector pointing from bony landmark A located on the inner epicondyle of the humerus in a three-dimensional bone model to bony landmark B located on the lateral epicondyle of the humerus is... The X-axis of the second registration coordinate system is defined by the midpoint of the line connecting bony landmark 1 and bony landmark 2 on both proximal sides of the three-dimensional bone model of the humerus. The plane AOB is defined by the origin O of the second registration coordinate system and the bony landmark A on the medial epicondyle of the three-dimensional bone model of the humerus pointing to the bony landmark B on the lateral epicondyle of the humerus. The direction that passes through the origin O of the second registration coordinate system and is perpendicular to the plane AOB upward is defined as the Y-axis of the second registration coordinate system. Thus, the second registration coordinate system can be obtained.

[0165] Establish the representation matrix of the first registration coordinate system and the representation matrix of the second registration coordinate system, and calculate the transformation matrix between the representation matrices of the first registration coordinate system and the second registration coordinate system as the target transformation matrix.

[0166] Specifically, the representation matrix O of the first registration coordinate system is established using mathematical methods. img The representation matrix O of the second registration coordinate system patient Then, the representation matrix O of the first registration coordinate system can be calculated. img The representation matrix O of the second registration coordinate system patient The transformation matrix between them is used as the target transformation matrix T. p2i-coarse The specific calculation formula is as follows:

[0167] Based on the target transformation matrix, spatial transformation is performed on each bony landmark on the affected bone to obtain the first spatial point set. Based on each bony landmark on the affected bone, the first transformation matrix is ​​calculated using the normal distribution transformation algorithm.

[0168] It should be noted that the representation matrix O of the first registration coordinate system img The 3x3 matrix in the upper left corner represents the direction vectors of the X-axis, Y-axis, and Z-axis in the first registration coordinate system. The 3x1 matrix to the right of the above 3x3 matrix represents the origin coordinates of the first registration coordinate system. The 1x3 matrix below the above 3x3 and 3x1 matrices represents {0, 0, 0, 1}.

[0169] The representation matrix O of the second registration coordinate system patient The 3x3 matrix in the upper left corner represents the direction vectors of the X-axis, Y-axis, and Z-axis in the second registration coordinate system. The 3x1 matrix to the right of the above 3x3 matrix represents the origin coordinates of the second registration coordinate system. The 1x3 matrix below the above 3x3 and 3x1 matrices represents {0, 0, 0, 1}.

[0170] In this embodiment, P can be used to represent the bony landmark point cloud on the affected bone, and Q can be used to represent the bony landmark point cloud on the three-dimensional bone model of the affected bone.

[0171] Based on the target change matrix T p2i-coarse By performing a spatial transformation on the bony landmark point cloud P on the affected bone, the bony landmark point cloud P on the affected bone can be transformed to the second registration coordinate system to obtain the first spatial point set P1.

[0172] Based on the bony landmark point cloud Q on the three-dimensional bone model of the affected bone, the first transformation matrix T can be calculated using the Normal Distribution Transform (NDT) algorithm. 1 The specific calculation steps include: dividing the bony landmark point cloud Q on the three-dimensional bone model into multiple grids, and calculating the mean value in each grid. The calculation formula is as follows:

[0173] Where μ represents the mean value in the grid; n represents the number of bony landmarks in the grid; b i This represents the position information of the i-th bony landmark in the grid.

[0174] The covariance of each grid cell is calculated using the following formula:

[0175] in,(*) t This indicates transpose.

[0176] Construct a normal distribution N(μ, Σ), whose probability density function p(b) i This can be represented as:

[0177] Using the initial transformation T = [R,t] to transform all points in the first spatial point set P1, the following evaluation function score(p) is established:

[0178] Among them, y i μ represents the i-th point in the first spatial point set P1; i Indicates y i The mean of the mesh containing the bony landmark point cloud Q mapped onto the 3D bone model after the initial transformation T = [R,t]; T(y i) represents the i-th point y in the first spatial point set P1. i The value after transformation according to the initial transformation T = [R, t].

[0179] The above evaluation function is optimized using Newton's optimization method, that is, to find the transformation parameter T = [R,t] that makes the value of the evaluation function score(p) optimal. The key step in the optimization is to solve for the Jacobian matrix and the Hessian matrix.

[0180] Repeat the above steps to optimize the evaluation function until the convergence condition is met, and obtain the first transformation matrix T. 1 .

[0181] Obtain the first transformation matrix T 1 Then, based on the first transformation matrix T 1 By performing a spatial transformation on the first spatial point set P1, we can obtain the second spatial point set P2.

[0182] After obtaining the second spatial point set P2, the iterative nearest point algorithm can be used to perform fine point cloud registration between the second spatial point set P2 and the bony landmark point cloud Q on the three-dimensional bone model of the affected bone. The specific steps include: using T = [R, t] to transform all points in the second spatial point set P2 to the bony landmark point cloud Q on the three-dimensional bone model of the affected bone, and defining the following energy function:

[0183] Where func′ represents the energy function value; w i The i-th point in the second spatial point set P2 is the closest point after transformation into the bony landmark point cloud Q; R represents the first transformation parameter; t represents the second transformation parameter; l i Let represent the i-th point in the second spatial point set P2.

[0184] It should be noted that the optimization objective of the energy function in this embodiment is to minimize the energy function value func′.

[0185] The optimal solutions for the first transformation parameter R and the second transformation parameter t are obtained using the Singular Value Decomposition (SVD) algorithm, thus yielding the second transformation matrix T. 2 In this embodiment, the optimal solution for the first transformation parameter R and the second transformation parameter t is the value of the first transformation parameter R and the value of the second transformation parameter t when the value of func′ is minimized. Based on the optimal solution for the first transformation parameter R and the second transformation parameter t, the second transformation matrix T is obtained. 2 The specific method is as follows: transform the top left 3x3 matrix to obtain the optimal solution for the first transformation parameter R, the right 3x1 matrix to obtain the optimal solution for the second transformation parameter t, and fill the bottom row with 0, 0, 0, 1 to obtain the second transformation matrix T. 2.

[0186] The first registration matrix T is used to describe the mapping relationship between the affected bone and the three-dimensional bone model. p2i-fine =T 1 *T 2 .

[0187] Obtain the first registration matrix T p2i-fine Subsequently, based on the mapping relationship between the three-dimensional bone model of the affected bone and the first image, and the first registration matrix T, the model can be further refined. p2i-fine A second registration matrix is ​​obtained through numerical calculation to describe the mapping relationship between the affected bone and the first image.

[0188] In this embodiment, the intraoperative execution module 106 establishes a first registration coordinate system corresponding to the affected bone based on the positional relationships between various bony landmarks on the affected bone, and a second registration coordinate system corresponding to the three-dimensional bone model based on the positional relationships between various bony landmarks on the three-dimensional bone model. Then, it establishes the representation matrix of the first registration coordinate system and the representation matrix of the second registration coordinate system, calculates the transformation matrix between the representation matrices of the first and second registration coordinate systems as the target transformation matrix, performs spatial transformation on the bony landmarks on the affected bone based on the target transformation matrix, obtains a first spatial point set, and calculates the first transformation matrix based on the bony landmarks on the affected bone using a normal distribution transformation algorithm. Finally, it performs spatial transformation on the first spatial point set based on the first transformation matrix. A second spatial point set is obtained by performing a spatial transformation on the point set. The iterative nearest point algorithm and singular value decomposition are then used to register the second spatial point set with each bony landmark on the 3D bone model. This yields a first registration matrix that describes the mapping relationship between the affected bone and the 3D bone model. By establishing a registration coordinate system corresponding to the affected bone and the 3D bone model and calculating the transformation matrix between them, the spatial relationship between the affected bone and the 3D bone model can be described more accurately. This overcomes the limitations of traditional point-pair-based registration algorithms and reduces registration errors caused by inaccurate bony landmarks on the affected bone or limited surgical area. Combining the normal distribution transformation algorithm and the iterative nearest point algorithm for spatial transformation and registration significantly improves the registration accuracy and robustness between the affected bone and the 3D bone model.

[0189] When a doctor performs orthopedic surgery on a affected bone using a handheld navigation and positioning device 2000, the human-computer interaction device can display real-time images of the affected bone during the operation, as well as the spatial position and pose of the navigation and positioning device 2000. It can also calculate the distance, angle, and other deviations between the navigation and positioning device 2000 and any position on the affected bone, providing visual feedback.

[0190] When bone grinding is required, to enhance visual feedback during the grinding process, the 3D bone model of the affected bone can be colored based on the parameters of the prosthesis to be implanted. Over-grinding, appropriately ground, and under-grinding areas are represented by red, white, and green, respectively. During the grinding process, the coloring information in the 3D bone model can be updated in real time based on the actual grinding progress and the position of the grinding tool, thus reflecting the grinding status and ensuring the grinding of the affected area is completed.

[0191] When grinding is required to implant central screws, fixation screws, or non-fixation screws into the affected bone, the central screws, fixation screws, and non-fixation screws can be tracked and displayed in real time. Furthermore, by calculating the distance of the central screw through the three-dimensional bone model of the affected bone, the direction of the central screw can be adjusted to ensure that the central screw does not protrude from the bone surface. At the same time, the direction of the fixation screws and non-fixation screws can be adjusted according to the patient's bony physiological structure, thereby achieving the most stable base fixation effect.

[0192] When it is necessary to install a base for the affected bone, the real-time position and orientation of the grinding tool and the installation tool can be obtained by the tracer on the affected bone side and the tracer on the navigation and positioning device 2000, so as to calculate the distance and angle deviation of the grinding reamer and the installation tool as well as the depth from the target position.

[0193] When bone reconstruction is required, different types of osteotomy guides can be used, including standard guides and personalized guides. During osteotomy, the error between the guide plane and the planned osteotomy plane is calculated and displayed in real time through the humeral tracer and the tracer installed on the guide.

[0194] During the implantation of the prosthesis for the affected bone, the position of the affected bone and the prosthesis can be obtained in real time by the tracer installed on the prosthesis and the tracer on the affected bone, and compared with the planned position. The deviation between the axis of the affected bone and the prosthesis and the anteversion angle and the plan can be provided in real time.

[0195] After the prosthesis is installed, in reverse shoulder replacement, a probe can be used to tap the liner and further confirm whether the liner is installed in place based on the position and posture of the humeral stem. In normal shoulder and hemi-shoulder replacement, the tracer on the ball head installer can be used to determine whether the ball head on the humeral stem is installed in place.

[0196] Figure 7 is a second structural schematic diagram of the shoulder joint replacement surgery navigation system provided in this application. As shown in Figure 7, the shoulder joint replacement surgery navigation system 1000 also includes a human-computer interaction device 1200 and a robot 3000.

[0197] The human-computer interaction device 1200 and the robot 3000 are respectively connected to the controller 1100 for communication.

[0198] The navigation and positioning device 2000 includes a navigation camera 2100, a patient tracker 2200, a robotic arm end effector tracker 2300, and a probe 2400.

[0199] Specifically, the controller 1100 can communicate with the navigation and positioning device 2000 to obtain the actual spatial position of the affected bone and surgical tools.

[0200] The controller 1100 is communicatively connected to the human-machine interaction device 1200 and the navigation camera 2100, respectively, receives information transmitted by the human-machine interaction device 1200 and the navigation camera 2100, and sends relevant information or instructions to the human-machine interaction device 1200 and the navigation camera 2100.

[0201] The patient tracer 2200 includes a humeral tracer and a scapular tracer, which are fixed to the patient's humerus and scapula respectively, and are used to determine the spatial position of the patient's affected side during surgery.

[0202] The robotic arm end effector 2300, mounted at the end of the robotic arm of robot 3000, is used to determine the spatial position of the robot's end effector. The probe 2400 is primarily used to collect bony landmarks of the patient's scapula and humerus.

[0203] The navigation camera 2100 receives signals from the patient tracker 2200, the robotic arm end effector tracker 2300, and the navigation tool 2500, determining the relative spatial positions of the robot 3000, probe 2400, and the patient's humerus and scapula in the same spatial coordinate system. With the spatial positional relationship between the patient's scapula and the robot's end effector determined, the navigation camera 2100 receives signals from the probe 2400 to complete the acquisition of bony landmarks on the patient's scapula and humerus.

[0204] The shoulder replacement surgery navigation system in this embodiment generates a three-dimensional bone model of the affected bone by combining preoperative medical images of the affected bone and medical images of the corresponding healthy bone. This model can more accurately reflect the healthy morphology of the affected bone even when bone defects and / or morphological abnormalities exist. Based on this three-dimensional bone model, prosthesis planning can be performed, obtaining parameter information of the prosthesis to be implanted. This makes preoperative surgical planning more objective and quantitative. Based on the parameter information of the prosthesis to be implanted, the system can simulate the range of motion of the patient's shoulder joint on the operated side after implantation, obtaining the maximum range of motion angle of the patient's shoulder joint on the operated side. If the maximum range of motion angle of the patient's shoulder joint is greater than a threshold, the system controls the navigation and positioning device to perform surgical navigation during shoulder replacement surgery based on the parameter information of the prosthesis to be implanted. This further improves the accuracy and rationality of prosthesis planning, reduces surgical complications and postoperative recovery time, significantly improves the accuracy and reliability of orthopedic surgery, effectively reduces surgical risks, and achieves more stable surgical results.

[0205] Figure 8 is a flowchart illustrating the shoulder joint replacement surgery navigation method provided in this application. As shown in Figure 8, the method includes the following steps: Step 801: Based on the first image and the second image, a three-dimensional bone model of the patient's affected bone is generated; based on the three-dimensional bone model of the affected bone, prosthesis planning is performed to obtain parameter information of the prosthesis to be implanted into the affected bone; the first image includes a medical image of the affected bone before the shoulder joint replacement surgery; the second image includes a medical image of the healthy bone corresponding to the affected bone; the affected bone and the healthy bone corresponding to the affected bone are symmetrically distributed with the spine as the midline; the parameter information includes size, posture information, and installation position information.

[0206] Step 802: Based on the parameter information of the prosthesis to be implanted, simulate the range of motion of the patient's shoulder joint on the operated side after the prosthesis is implanted into the affected bone, and obtain the maximum range of motion of the patient's shoulder joint on the operated side.

[0207] Step 803: When it is determined that the maximum range of motion of the patient's shoulder joint on the operated side is greater than the range of motion threshold, the navigation and positioning device is controlled to perform surgical navigation in the shoulder joint replacement surgery targeting the affected bone based on the parameter information of the prosthesis to be implanted.

[0208] It should be noted that the shoulder joint replacement surgery navigation method in this application embodiment is implemented based on the aforementioned shoulder joint replacement surgery navigation system 1000. The specific execution steps of the shoulder joint replacement surgery navigation method can be found in the contents of the above embodiments, and will not be repeated in this application embodiment.

[0209] This application embodiment generates a three-dimensional bone model of the affected bone by combining preoperative medical images of the affected bone and medical images of the corresponding healthy bone. This model can more accurately reflect the healthy morphology of the affected bone even when bone defects and / or morphological abnormalities exist. Furthermore, it enables prosthesis planning based on the three-dimensional bone model, obtaining parameter information of the prosthesis to be implanted. This makes preoperative surgical planning more objective and quantitative. Based on the parameter information of the prosthesis to be implanted, it can simulate the range of motion of the patient's shoulder joint on the operated side after implantation, obtaining the maximum range of motion angle of the patient's shoulder joint on the operated side. If the maximum range of motion angle of the patient's shoulder joint is determined to be greater than a threshold, the navigation and positioning device is controlled to perform surgical navigation during shoulder joint replacement surgery based on the parameter information of the prosthesis to be implanted. This further improves the accuracy and rationality of prosthesis planning, reduces surgical complications and postoperative recovery time, significantly improves the accuracy and reliability of orthopedic surgery, effectively reduces surgical risks, and achieves more stable surgical results.

[0210] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A shoulder arthroplasty surgical navigation system, comprising: A controller and a navigation and positioning device; the controller is communicatively connected to the navigation and positioning device; the controller includes a preoperative planning module, a preoperative simulation module, and an intraoperative execution module; The preoperative planning module is used to generate a three-dimensional bone model of the patient's affected bone based on the first image and the second image, and to perform prosthesis planning based on the three-dimensional bone model of the affected bone to obtain parameter information of the prosthesis to be implanted in the affected bone. The first image includes a medical image of the affected bone before shoulder joint replacement surgery, and the second image includes a medical image of the healthy bone corresponding to the affected bone. The affected bone and the healthy bone corresponding to the affected bone are symmetrically distributed with the spine as the midline. The parameter information includes size, posture information and installation position information. The preoperative simulation module is used to simulate the range of motion of the patient's shoulder joint on the surgical side after the prosthesis is implanted into the affected bone, based on the parameter information of the prosthesis to be implanted, and to obtain the maximum range of motion of the patient's shoulder joint on the surgical side. The intraoperative execution module is used to control the navigation and positioning device to perform surgical navigation in the shoulder joint replacement surgery targeting the affected bone, based on the parameter information of the prosthesis to be implanted, when it is determined that the maximum range of motion of the patient's operated shoulder joint is greater than the range of motion threshold. The navigation and positioning device is used to provide surgical navigation in response to the control of the intraoperative execution module during shoulder replacement surgery for the affected bone.

2. The shoulder arthroplasty surgery navigation system of claim 1, wherein, The preoperative planning module includes a prosthesis planning unit; When the affected bone is the scapula, the prosthesis planning unit is specifically used to perform spatial correction on the three-dimensional bone model of the affected bone. After obtaining the spatially corrected three-dimensional bone model of the affected bone, the bony information of the affected bone is calculated based on the spatially corrected three-dimensional bone model. Based on the bony information of the affected bone, the size and posture information of the prosthesis to be implanted are obtained. Based on the size and posture information of the prosthesis to be implanted, the installation position information of the prosthesis to be implanted is obtained using an invasiveness optimization algorithm. Then, the size, posture information and installation position information of the prosthesis to be implanted are determined as the parameter information of the prosthesis to be implanted. The bony information of the affected bone includes the positional information of the superior, inferior, anterior, and posterior edges of the glenoid cavity, the normal direction of the glenoid plane, and the original posterior and superior tilt angles of the glenoid cavity. The normal direction of the glenoid plane is the direction from the glenoid plane of the affected bone to the normal of the humerus connected to the glenoid cavity. The glenoid plane of the affected bone is obtained by fitting the superior, inferior, anterior, and posterior edges of the glenoid cavity. The original posterior tilt angle of the glenoid cavity is the angle between the projection line of the normal direction of the glenoid plane of the affected bone in the transverse position and the target auxiliary line of the affected bone. The original superior tilt angle of the glenoid cavity is the angle between the projection line of the normal direction of the glenoid plane of the affected bone in the coronal position and the target auxiliary line of the affected bone. The target auxiliary line is the line connecting the innermost point of the scapula and the center point of the glenoid cavity of the scapula.

3. The shoulder arthroplasty surgery navigation system of claim 2, wherein, The preoperative simulation module is specifically used to generate a three-dimensional bone model of the patient's surgical shoulder joint after the implanted prosthesis is inserted into the affected bone, based on the parameter information of the prosthesis to be implanted. When the posture of the three-dimensional bone model of the patient's surgical shoulder joint is a preset posture, the humerus in the three-dimensional bone model of the patient's surgical shoulder joint is rotated in each preset direction until the humerus in the three-dimensional bone model of the patient's surgical shoulder joint collides with the scapula in the three-dimensional bone model of the patient's surgical shoulder joint. The rotation angle of the humerus in the three-dimensional bone model of the patient's surgical shoulder joint at the time of collision is determined as the maximum range of motion of the three-dimensional bone model of the patient's surgical shoulder joint in each preset direction. The intraoperative execution module is used to send the maximum range of motion of the three-dimensional bone model of the patient's operated shoulder joint in any preset direction to the prosthesis planning unit when it is determined that the maximum range of motion of the three-dimensional bone model of the patient's operated shoulder joint in any preset direction is not greater than the range of motion threshold corresponding to the preset direction. The prosthesis planning unit then updates the parameter information of the prosthesis to be implanted based on the maximum range of motion of the three-dimensional bone model of the patient's operated shoulder joint in any preset direction. When it is determined that the maximum range of motion of the three-dimensional bone model of the patient's operated shoulder joint in each preset direction is greater than the range of motion threshold corresponding to each preset direction, the module controls the navigation and positioning device to perform surgical navigation in the shoulder joint replacement surgery for the affected bone based on the parameter information of the prosthesis to be implanted.

4. The shoulder arthroplasty surgery navigation system of claim 2, wherein, The prosthesis planning unit is specifically used to determine the original posterior tilt angle and original superior tilt angle of the glenoid cavity of the affected bone as the posture information of the prosthesis to be implanted. Based on the size and posture information of the prosthesis to be implanted, a three-dimensional model of the prosthesis to be implanted is constructed. The nearest distance between any point on the base plane of the three-dimensional model of the prosthesis to be implanted and the three-dimensional bone model of the affected bone is defined as the invasive amount corresponding to any point. Based on a predefined ideal invasive amount range, the invasive amount score corresponding to each position of the three-dimensional model of the prosthesis to be implanted is calculated when the three-dimensional model of the prosthesis to be implanted is within the installation range of the three-dimensional bone model of the affected bone. Then, the position with the highest invasive amount score within the installation range of the three-dimensional bone model of the affected bone is determined as the installation position of the prosthesis to be implanted, thus obtaining the installation position information of the prosthesis to be implanted. The installation range of the three-dimensional bone model of the affected bone is determined based on the upper pole, lower pole, anterior edge, and posterior edge of the glenoid cavity of the affected bone.

5. The shoulder arthroplasty surgery navigation system of claim 1, wherein, The intraoperative execution module is further configured to determine several bony landmarks at the proximal end of the three-dimensional bone model and several bony landmarks at the distal end of the three-dimensional bone model. Then, in the shoulder replacement surgery for the affected bone, based on the correspondence between each bony landmark on the three-dimensional bone model and each bony landmark on the affected bone, the affected bone and the three-dimensional bone model are registered to establish a mapping relationship between the affected bone and the three-dimensional bone model and / or the first image. Based on the parameter information of the prosthesis to be implanted and the mapping relationship, the navigation and positioning device is controlled to perform surgical navigation in the shoulder replacement surgery for the affected bone. The proximal end is the end closer to the incision, and the distal end is the end farther from the incision.

6. The shoulder arthroplasty surgery navigation system of claim 5, wherein, The intraoperative execution module is specifically used to establish a first registration coordinate system corresponding to the affected bone based on the positional relationship between the bony landmarks on the affected bone, and to establish a second registration coordinate system corresponding to the three-dimensional bone model based on the positional relationship between the bony landmarks on the three-dimensional bone model. It also establishes representation matrices for the first and second registration coordinate systems, calculates a transformation matrix between the representation matrices of the first and second registration coordinate systems as the target transformation matrix, and performs spatial transformation on the bony landmarks on the affected bone based on the target transformation matrix to obtain a first spatial point set. For each of the bony landmarks on the affected bone, a first transformation matrix is ​​calculated using a normal distribution transformation algorithm. Based on the first transformation matrix, a spatial transformation is performed on the first spatial point set to obtain a second spatial point set. The iterative nearest point algorithm and singular value decomposition are used to register the second spatial point set with each of the bony landmarks on the three-dimensional bone model to obtain a first registration matrix describing the mapping relationship between the affected bone and the three-dimensional bone model. Based on the mapping relationship between the three-dimensional bone model and the first image and the first registration matrix, a second registration matrix describing the mapping relationship between the affected bone and the first image is obtained.

7. The shoulder arthroplasty surgery navigation system of claim 2, wherein, The preoperative planning module also includes a data import unit and an image processing unit; The data import unit is used to acquire the first image and the second image, and send the first image and the second image to the image processing unit when the image quality of the first image and the second image meets the preset standard. The image processing unit is used to construct a first three-dimensional point cloud model based on the first image, construct a second three-dimensional point cloud model based on the second image, extract the centroids of the first and second three-dimensional point cloud models, mirror the second three-dimensional point cloud model along the horizontal direction based on the centroids of the first and second three-dimensional point cloud models to obtain a third three-dimensional point cloud model, align the first and third three-dimensional point cloud models based on the centroids of the first and third three-dimensional point cloud models, obtain the feature descriptor of each point in the third three-dimensional point cloud model, and then, based on the feature descriptor of each point in the third three-dimensional point cloud model, perform coarse point cloud registration on the third three-dimensional point cloud model and the first three-dimensional point cloud model using a consistent initial registration algorithm to obtain a fourth three-dimensional point cloud model, and perform fine point cloud registration on the fourth three-dimensional point cloud model and the first three-dimensional point cloud model using an iterative nearest point algorithm and singular value decomposition to obtain a three-dimensional bone model of the affected bone. The prosthesis planning unit is used to obtain the bony information of the affected bone based on the three-dimensional bone model of the affected bone, and then to plan the prosthesis based on the bony information of the affected bone to obtain the parameter information of the prosthesis to be implanted.

8. The shoulder arthroplasty surgery navigation system of claim 7, wherein, The image processing unit is specifically used to preprocess the first image to obtain a preprocessed first image when the image quality of the first image meets a preset standard. Based on the distribution of the bone fragments of the affected bone, the preprocessed first image is segmented to obtain multiple sub-images corresponding to the first image. Each sub-image includes only one bone fragment of the affected bone. The sub-image of the largest bone fragment of the affected bone is determined as the target sub-image. Based on the target sub-image, a three-dimensional point cloud model of the largest bone fragment of the affected bone is constructed as the first three-dimensional point cloud model.

9. The shoulder arthroplasty surgical navigation system of any of claims 1 to 8, further comprising: Human-computer interaction devices and robots; The human-computer interaction device and the robot are respectively communicatively connected to the controller; The navigation and positioning device includes a navigation camera, a patient tracker, a robotic arm end effector tracker, and a probe.

10. A method for navigating shoulder joint replacement surgery based on the shoulder joint replacement surgery navigation system as described in any one of claims 1 to 9, comprising: Based on the first and second images, a three-dimensional bone model of the patient's affected bone is generated. Based on the three-dimensional bone model of the affected bone, prosthesis planning is performed to obtain parameter information of the prosthesis to be implanted in the affected bone. The first image includes a medical image of the affected bone before shoulder joint replacement surgery. The second image includes a medical image of the healthy bone corresponding to the affected bone. The affected bone and the healthy bone corresponding to the affected bone are symmetrically distributed with the spine as the midline. The parameter information includes size, posture information and installation position information. Based on the parameter information of the prosthesis to be implanted, the range of motion of the patient's shoulder joint on the operated side after the prosthesis to be implanted into the affected bone is simulated to obtain the maximum range of motion of the patient's shoulder joint on the operated side. In a case where it is determined that the maximum movement angle of the shoulder joint of the operation side of the patient is greater than the movement angle threshold value, a navigation positioning device is controlled to perform surgical navigation in a shoulder joint replacement surgery for the affected bone based on the parameter information of the to-be-implanted prosthesis.

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