Elbow joint suture anchor implantation direction determination method and device, electronic equipment, storage medium and program product

Abstract

The invention provides a method and a device for determining the placement direction of an elbow joint suture anchor, electronic equipment, a storage medium and a program product. The determination method comprises the following steps: acquiring elbow joint three-dimensional image data and suture anchor data of a target patient; constructing a reference three-dimensional coordinate system based on preset anatomical feature points in the elbow joint three-dimensional image data; based on the elbow joint three-dimensional image data and the suture anchor data, a plurality of anchor-imbedded elbow joint models are constructed according to a reference three-dimensional coordinate system, and each anchor-imbedded elbow joint model is used for representing that a suture anchor is imbedded into the elbow joint of the target patient along a candidate imbedding direction; performing mechanical analysis and calculation on the plurality of elbow joint models with the embedded anchors to obtain mechanical information corresponding to each elbow joint model with the embedded anchors; and according to the mechanical information corresponding to the elbow joint models with the rivets, one of the candidate implantation directions corresponding to the elbow joint models with the rivets is determined to serve as a preferred implantation direction.

Description

Technical Field

[0001] The present disclosure generally relates to the field of biomechanics technology, and more specifically, to a method, device, electronic device, storage medium and program product for determining an insertion direction of a suture anchor in an elbow joint. Background Art

[0002] Elbow sports injury is one of the most common diseases in clinical practice. Joint and tendon injuries caused by osteoarthritis and tennis elbow can cause pain and limited activity, seriously affecting the patient's normal life. In recent years, arthroscopic surgery has gradually replaced traditional open surgery due to its advantages of less trauma and faster recovery. However, elbow arthroscopic surgery has certain technical bottlenecks, and the surgical effect is heavily dependent on the surgeon's clinical experience and lacks accurate preoperative planning. Elbow arthroscopic tendon repair surgery relies on suture anchors to repair damaged tendons. During the insertion of the anchor, if the direction of the anchor is offset, it may even penetrate the cortical bone, fall or enter the joint. At the same time, anchor fixation failure will also lead to the failure of tendon repair surgery. The reasons for anchor fixation failure include loosening, displacement, and extraction of the anchor, which ultimately lead to articular cartilage damage, pain, and even secondary surgery. The anchor fixation strength is related to factors such as the anchor design, the patient's bone density, the anchor insertion depth, and the insertion angle. Therefore, determining the optimal insertion direction of the anchor is a key technology in elbow arthroscopic surgery.

[0003] Due to the complex anatomical structure of the elbow joint and individual differences in the humeral structure, the direction of anchor insertion will cause significant differences in mechanical strength and clinical recovery function. However, there is currently a lack of research on the direction of anchor insertion. In elbow arthroscopy, the position and direction of anchor insertion are determined entirely by the surgeon's experience. In order to avoid deviations in the direction of the suture anchor, the occurrence of penetrating cortical bone, detaching from or entering the joint, repeated fluoroscopy is required, which increases the risk of surgery and exposes the surgeon to radiation for a long time.

[0004] From the perspective of numerical analysis technology, although the existing finite element modeling technology can establish a finite element model of bone tissue with accurate appearance and similar material properties, for different samples, due to the inconsistent body posture of the human body when scanning medical images such as CT (Computed Tomography) and MRI (Magnetic Resonance Imaging), the three-dimensional coordinate system of the scanned image is inconsistent, and the existing technology cannot put different samples into the same coordinate system for comparison. For elbow surgery, if the optimal insertion direction of suture anchors in elbow arthroscopy is studied, it is necessary to unify the distal humeral coordinate systems of multiple elbow joint images to describe the insertion site of the suture anchor. Therefore, it is particularly necessary to realize a modeling method for a unified distal humeral coordinate system to achieve accurate preoperative planning of elbow arthroscopy. Summary of the invention

[0005] The present disclosure provides a method, device, electronic device, storage medium and program product for determining the insertion direction of an elbow joint suture anchor, which are used to solve at least one of the above problems.

[0006] According to a first aspect of an embodiment of the present disclosure, a method for determining an insertion direction of an elbow joint suture anchor is provided, the method comprising: acquiring three-dimensional image data of an elbow joint and suture anchor data of a target patient; constructing a reference three-dimensional coordinate system based on preset anatomical feature points in the three-dimensional image data of the elbow joint; constructing a plurality of elbow joint models with anchors inserted according to the reference three-dimensional coordinate system based on the three-dimensional image data of the elbow joint and the suture anchor data, wherein each elbow joint model with anchors inserted is used to represent that a suture anchor is inserted into the elbow joint of the target patient along a candidate insertion direction, and the plurality of elbow joint models with anchors inserted correspond to the plurality of candidate insertion directions one by one; performing mechanical analysis and calculation on the plurality of elbow joint models with anchors inserted, respectively, to obtain mechanical information corresponding to each elbow joint model with anchors inserted; and determining one of the plurality of candidate insertion directions corresponding to the plurality of elbow joint models with anchors inserted as a preferred insertion direction according to the mechanical information corresponding to each of the plurality of elbow joint models with anchors inserted.

[0007] Optionally, the preset anatomical feature points include the apex of the medial epicondyle, the apex of the lateral epicondyle, the lowest point of the trochlear ridge, and the midpoint of the narrowest part of the distal humeral cortex, wherein the construction of a reference three-dimensional coordinate system based on the preset anatomical feature points in the three-dimensional image data of the elbow joint includes: determining the straight line where the apex of the medial epicondyle and the apex of the lateral epicondyle are located as the X-axis of the reference three-dimensional coordinate system, determining the apex of the lateral epicondyle as the origin of the reference three-dimensional coordinate system, and determining the direction where the apex of the medial epicondyle is located as the positive direction of the X-axis; determining a line perpendicular to the X-axis and passing through the apex of the medial epicondyle as the origin of the reference three-dimensional coordinate system. The plane passing through the lowest point of the trochlear crest is determined as the reference sagittal plane; the straight line parallel to the reference Z axis in the reference sagittal plane and passing through the origin is determined as the Z axis of the reference three-dimensional coordinate system, and the straight line perpendicular to both the X axis and the Z axis is determined as the Y axis of the reference three-dimensional coordinate system, wherein the reference Z axis is a straight line in the reference sagittal plane passing through the midpoint of the narrowest part of the distal humeral cortex and tangent to the innermost side of the cortex of the humeral body; based on the right-hand rule, the positive directions of the Y axis and the Z axis are determined according to the positive direction of the X axis.

[0008] Optionally, the original three-dimensional coordinate system in the three-dimensional image data of the elbow joint includes an original horizontal plane, an original coronal plane and an original sagittal plane, wherein the plane perpendicular to the X-axis and passing through the lowest point of the trochlear crest is determined as the reference sagittal plane, including: translating and rotating the original coronal plane and the original horizontal plane to obtain an adjusted coronal plane, an adjusted horizontal plane and a corresponding adjusted sagittal plane, so that the intersection of the adjusted coronal plane and the adjusted horizontal plane coincides with the X-axis; within the adjusted coronal plane, translating the adjusted sagittal plane to pass through the lowest point of the trochlear crest to obtain the reference sagittal plane; wherein the straight line parallel to the reference Z axis in the reference sagittal plane and passing through the origin is determined as the reference three-dimensional coordinate system. The Z axis of the reference three-dimensional coordinate system is determined as the Y axis of the reference three-dimensional coordinate system, and a straight line perpendicular to both the X axis and the Z axis is determined as the Y axis of the reference three-dimensional coordinate system, including: translating and rotating the adjusted coronal plane in the reference sagittal plane to obtain a reference coronal plane, so that the reference coronal plane passes through the midpoint of the narrowest part of the distal cortex of the humerus and is tangent to the innermost side of the cortex of the humeral body, and correspondingly rotating the adjusted horizontal plane to obtain a reference horizontal plane; translating the reference horizontal plane, the reference coronal plane and the reference sagittal plane to intersect each other at the origin, and determining the intersection line of the reference coronal plane and the reference sagittal plane after translation as the Z axis, and determining the intersection line of the reference horizontal plane and the reference sagittal plane after translation as the Y axis.

[0009] Optionally, constructing multiple elbow joint models with implanted anchors based on the elbow joint three-dimensional image data and the suture anchor data according to the reference three-dimensional coordinates includes: constructing the elbow joint model based on the elbow joint three-dimensional image data; determining the multiple candidate implantation directions in the three-dimensional space described by the reference three-dimensional coordinate system; for each candidate implantation direction, constructing an elbow joint model with the suture anchor implanted into the elbow joint model along the candidate implantation direction based on the suture anchor data, to obtain the multiple elbow joint models with the implanted anchors.

[0010] Optionally, the reference three-dimensional coordinate system includes a horizontal plane, a coronal plane, and a sagittal plane that are perpendicular to each other, the intersection line of the horizontal plane and the coronal plane is the X-axis of the reference three-dimensional coordinate system, the intersection line of the horizontal plane and the sagittal plane is the Y-axis of the reference three-dimensional coordinate system, and the intersection line of the coronal plane and the sagittal plane is the Z-axis of the reference three-dimensional coordinate system, wherein determining the multiple candidate implantation directions in the three-dimensional space described by the reference three-dimensional coordinate system includes: rotating the horizontal plane around the Y-axis by multiple first preset angles to obtain multiple rotated horizontal planes, and rotating the coronal plane around the Z-axis by multiple second preset angles to obtain multiple rotated coronal planes; determining the direction of the intersection line of a rotated horizontal plane and a rotated coronal plane as a candidate implantation direction, and determining the multiple candidate implantation directions based on the multiple rotated horizontal planes and the multiple rotated coronal planes.

[0011] Optionally, the positive direction of the Z axis is the direction from the distal end of the humerus to the proximal end of the humerus, and the angle of rotation of the horizontal plane around the Y axis toward the positive direction close to the Z axis is positive, and the multiple first preset angles are all positive angles; the multiple second preset angles include 0, positive angles and negative angles.

[0012] According to a second aspect of an embodiment of the present disclosure, a device for determining the placement direction of a suture anchor in an elbow joint is provided, the device comprising: an acquisition unit configured to acquire three-dimensional image data of a target patient's elbow joint and suture anchor data; a coordinate construction unit configured to construct a reference three-dimensional coordinate system based on preset anatomical feature points in the three-dimensional image data of the elbow joint; and a model construction unit configured to construct a plurality of elbow joint models with anchors placed therein according to the reference three-dimensional coordinate system based on the three-dimensional image data of the elbow joint and the suture anchor data, wherein the direction of each elbow joint with the anchor placed therein is determined by the following steps: The model is used to represent that a suture anchor is placed into the elbow joint of the target patient along a candidate placement direction, and the multiple elbow joint models of the placed anchors correspond one-to-one to the multiple candidate placement directions; the calculation unit is configured to perform mechanical analysis and calculation on the multiple elbow joint models of the placed anchors respectively to obtain mechanical information corresponding to each elbow joint model of the placed anchors; the determination unit is configured to determine one from the multiple candidate placement directions corresponding to the elbow joint models of the multiple placed anchors as the preferred placement direction based on the mechanical information corresponding to each of the elbow joint models of the multiple placed anchors.

[0013] Optionally, the preset anatomical feature points include the apex of the medial epicondyle, the apex of the lateral epicondyle, the lowest point of the trochlear ridge, and the midpoint of the narrowest part of the distal humeral cortex, and the coordinate construction unit is further configured to: determine the straight line where the apex of the medial epicondyle and the apex of the lateral epicondyle are located as the X-axis of the reference three-dimensional coordinate system, determine the apex of the lateral epicondyle as the origin of the reference three-dimensional coordinate system, and determine the direction where the apex of the medial epicondyle is located as the positive direction of the X-axis; determine the plane perpendicular to the X-axis and passing through the lowest point of the trochlear ridge The reference sagittal plane is used as the reference plane; a straight line parallel to the reference Z axis in the reference sagittal plane and passing through the origin is determined as the Z axis of the reference three-dimensional coordinate system, and a straight line perpendicular to both the X axis and the Z axis is determined as the Y axis of the reference three-dimensional coordinate system, wherein the reference Z axis is a straight line in the reference sagittal plane that passes through the midpoint of the narrowest part of the distal humeral cortex and is tangent to the innermost side of the cortex of the humeral body; based on the right-hand rule, the positive directions of the Y axis and the Z axis are determined according to the positive direction of the X axis.

[0014] Optionally, the original three-dimensional coordinate system in the three-dimensional image data of the elbow joint includes an original horizontal plane, an original coronal plane and an original sagittal plane, and the coordinate construction unit is further configured to: translate and rotate the original coronal plane and the original horizontal plane to obtain an adjusted coronal plane, an adjusted horizontal plane and a corresponding adjusted sagittal plane, so that the intersection line of the adjusted coronal plane and the adjusted horizontal plane coincides with the X-axis; in the adjusted coronal plane, translate the adjusted sagittal plane to pass through the lowest point of the trochlear crest to obtain the reference sagittal plane; in the reference sagittal plane, The adjusted coronal plane is translated and rotated to obtain a reference coronal plane, so that the reference coronal plane passes through the midpoint of the narrowest part of the distal humeral cortex and is tangent to the innermost side of the cortex of the humeral body, and the adjusted horizontal plane is rotated accordingly to obtain a reference horizontal plane; the reference horizontal plane, the reference coronal plane and the reference sagittal plane are translated to intersect each other at the origin, and the intersection line of the reference coronal plane and the reference sagittal plane after translation is used as the Z axis, and the intersection line of the reference horizontal plane and the reference sagittal plane after translation is determined as the Y axis.

[0015] Optionally, the model construction unit is further configured to: construct an elbow joint model based on the three-dimensional image data of the elbow joint; determine the multiple candidate insertion directions in the three-dimensional space described by the reference three-dimensional coordinate system; for each candidate insertion direction, based on the suture anchor data, construct an elbow joint model in which a suture anchor is inserted into the elbow joint model along the candidate insertion direction to obtain the multiple elbow joint models with the insertion anchors.

[0016] Optionally, the reference three-dimensional coordinate system includes a horizontal plane, a coronal plane and a sagittal plane that are perpendicular to each other, the intersection line of the horizontal plane and the coronal plane is the X-axis of the reference three-dimensional coordinate system, the intersection line of the horizontal plane and the sagittal plane is the Y-axis of the reference three-dimensional coordinate system, and the intersection line of the coronal plane and the sagittal plane is the Z-axis of the reference three-dimensional coordinate system, and the model building unit is further configured to: rotate the horizontal plane around the Y-axis by multiple first preset angles to obtain multiple rotated horizontal planes, and rotate the coronal plane around the Z-axis by multiple second preset angles to obtain multiple rotated coronal planes; determine the direction of the intersection line of a rotated horizontal plane and a rotated coronal plane as a candidate implantation direction, and determine the multiple candidate implantation directions based on the multiple rotated horizontal planes and the multiple rotated coronal planes.

[0017] Optionally, the positive direction of the Z axis is the direction from the distal end of the humerus to the proximal end of the humerus, and the angle of rotation of the horizontal plane around the Y axis toward the positive direction close to the Z axis is positive, and the multiple first preset angles are all positive angles; the multiple second preset angles include 0, positive angles and negative angles.

[0018] According to a third aspect of an embodiment of the present disclosure, an electronic device is provided, comprising: at least one processor; and at least one memory storing computer executable instructions, wherein the computer executable instructions, when executed by the at least one processor, prompt the at least one processor to execute a method for determining an elbow joint suture anchor placement direction according to an exemplary embodiment of the present disclosure.

[0019] According to a fourth aspect of an embodiment of the present disclosure, a computer-readable storage medium is provided. When instructions in the computer-readable storage medium are executed by at least one processor, the at least one processor is prompted to execute a method for determining an elbow joint suture anchor placement direction according to an exemplary embodiment of the present disclosure.

[0020] According to a fifth aspect of an embodiment of the present disclosure, a computer program product is provided, comprising computer instructions, which, when executed by at least one processor, prompt the at least one processor to execute a method for determining an elbow joint suture anchor placement direction according to an exemplary embodiment of the present disclosure.

[0021] The technical solution provided by the embodiments of the present disclosure brings at least the following beneficial effects: According to the method and device for determining the insertion direction of the elbow joint suture anchor disclosed in the present disclosure, the reference three-dimensional coordinate system is constructed by taking the preset anatomical feature points inherent in the human body as the reference, and a unified three-dimensional coordinate system can be reliably constructed, so as to accurately quantify the insertion point and insertion direction of the suture anchor, and establish a model of the suture anchor being inserted into the elbow joint along different insertion directions. On this basis, by analyzing the mechanical strength of the suture anchor at different insertion angles, the preferred insertion direction of the suture anchor is determined, which helps to reduce the occurrence of suture anchors penetrating cortical bones, falling or entering joints during surgery, and reduces the failure of surgery due to loosening, displacement, and extraction of suture anchors after surgery. The method disclosed in the present disclosure helps to achieve accurate preoperative planning, thereby improving the safety of elbow arthroscopic surgery, and can also reduce the surgeon's dependence on arthroscopic surgery experience and reduce medical costs.

[0022] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the description are used to explain the principles of the present disclosure, and do not constitute improper limitations on the present disclosure.

[0024] Figure 1 is a flow chart of a method for determining an implantation direction of a suture anchor in an elbow joint according to an exemplary embodiment of the present disclosure.

[0025] Figure 2is a schematic diagram of an elbow joint skeleton according to an exemplary embodiment of the present disclosure.

[0026] Figure 3 is a schematic diagram of a reference three-dimensional coordinate system according to an exemplary embodiment of the present disclosure.

[0027] Figure 4 It is a schematic diagram of a two-dimensional image of a reconstructed image in three original planes according to a specific embodiment of the present disclosure.

[0028] Figure 5 It is a schematic diagram of a two-dimensional image of a reconstructed image in three adjustment planes according to a specific embodiment of the present disclosure.

[0029] Figure 6 It is a schematic diagram of a two-dimensional image of a reconstructed image in an adjusted coronal plane, an adjusted horizontal plane after translation, and a reference sagittal plane according to a specific embodiment of the present disclosure.

[0030] Figure 7 It is a schematic diagram of a two-dimensional image of a reconstructed image according to a specific embodiment of the present disclosure, including an adjusted coronal plane after translation, an adjusted horizontal plane after further translation, and a reference sagittal plane.

[0031] Figure 8 It is a schematic diagram of a two-dimensional image of a reconstructed image on three reference planes according to a specific embodiment of the present disclosure.

[0032] Fig. 9 It is a schematic diagram of a two-dimensional image of three planes of a reference three-dimensional coordinate system of a reconstructed image according to a specific embodiment of the present disclosure.

[0033] Fig.10 is a schematic diagram of an elbow joint model with an anchor placed according to an exemplary embodiment of the present disclosure.

[0034] Fig.11 is a schematic diagram of multiple rotating horizontal planes according to an exemplary embodiment of the present disclosure.

[0035] Fig.12 are schematic diagrams of multiple rotated coronal planes according to an exemplary embodiment of the present disclosure.

[0036] Fig.13 is a schematic diagram of a finite element mesh according to a specific embodiment of the present disclosure.

[0037] Fig.14 4 is a block diagram of a device for determining an implantation direction of a suture anchor in an elbow joint according to an exemplary embodiment of the present disclosure.

[0038] Fig.15 is a block diagram of an electronic device according to an exemplary embodiment of the present disclosure.

[0039] Figure 2Description of Figure Numbers:

[0040] 10: humerus; 11: medial epicondyle; 12: lateral epicondyle; 13: capitulum of humerus; 14: trochlea of ​​humerus;

[0041] 20: radius; 21: radial head; 22: radial tuberosity;

[0042] 30: ulna; 31: olecranon; 32: trochlear notch; 33: coronoid process. DETAILED DESCRIPTION

[0043] In order to enable ordinary persons in the art to better understand the technical solutions of the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings.

[0044] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. The implementation methods described in the following examples do not represent all implementation methods consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the attached claims.

[0045] It should be noted that the phrase "at least one of the items" in the present disclosure includes three types of parallel situations: "any one of the items", "a combination of any number of the items", and "all of the items". For example, "including at least one of A and B" includes the following three parallel situations: (1) including A; (2) including B; (3) including A and B. Another example is "executing at least one of step 1 and step 2" which means the following three parallel situations: (1) executing step 1; (2) executing step 2; (3) executing step 1 and step 2.

[0046] Hereinafter, a method and apparatus for determining the placement direction of an elbow joint suture anchor according to exemplary embodiments of the present disclosure, an electronic device, and a storage medium will be described in detail with reference to the accompanying drawings.

[0047] Figure 1 1 is a flow chart of a method for determining an elbow joint suture anchor placement direction according to an exemplary embodiment of the present disclosure. The method can be executed on an electronic device with sufficient computing power.

[0048] Reference Figure 1 In step S101, three-dimensional image data and suture anchor data of the target patient's elbow joint are obtained.

[0049] The three-dimensional image data of the elbow joint is obtained by photographing the elbow joint of the target patient using medical equipment, for example including but not limited to CT data and MRI data.

[0050] Suture anchor data is data used to describe the suture anchor, for example, including but not limited to the structural dimension data, material property data, and insertion point data of the suture anchor, wherein the structural dimension data and material property data are data used to describe the suture anchor itself, and the insertion point data is data used to describe the insertion point when the suture anchor is inserted into the elbow joint, specifically located near the apex of the lateral epicondyle of the humerus, for example, it can be determined by combining existing surgical experience, or by other theoretical analysis methods. The present disclosure does not limit this, and it can be fine-tuned in the subsequent modeling and analysis process.

[0051] In step S102, a reference three-dimensional coordinate system is constructed based on preset anatomical feature points in the three-dimensional image data of the elbow joint.

[0052] Anatomical feature points are characteristic points inherent in the human skeleton, and preset anatomical feature points are pre-selected anatomical feature points, including but not limited to the vertices of the medial and lateral epicondyles of the humerus. By using the preset anatomical feature points inherent in the human body as a reference to construct a reference three-dimensional coordinate system, a unified three-dimensional coordinate system can be reliably constructed, thereby accurately quantitatively describing the insertion point and insertion direction of the suture anchor, and in subsequent steps, a model of suture anchors inserted into the elbow joint along different insertion directions can be established. In addition, constructing a unified three-dimensional coordinate system between different individual samples is also conducive to studying more general biological laws.

[0053] In step S103, based on the elbow joint three-dimensional image data and the suture anchor data, a plurality of elbow joint models with anchors inserted are constructed according to a reference three-dimensional coordinate system.

[0054] As the name implies, the elbow joint model with anchors inserted is a model obtained by modeling the elbow joint with suture anchors inserted. Therefore, to construct a model, not only the three-dimensional image data of the elbow joint and the suture anchor data obtained in step S101 are required, but also the specific insertion direction needs to be clarified. Each elbow joint model with anchors inserted is used to represent the insertion of the suture anchor into the elbow joint of the target patient along a candidate insertion direction. Multiple elbow joint models with anchors inserted correspond to multiple candidate insertion directions one by one, thereby achieving modeling for different candidate insertion directions.

[0055] In step S104, mechanical analysis and calculation are performed on the elbow joint models with multiple anchors inserted respectively to obtain mechanical information corresponding to each elbow joint model with each anchor inserted.

[0056] This step can be implemented with reference to existing mechanical analysis and calculation methods, such as but not limited to the finite element method. Specifically, in general, the research methods for bone tissue mainly include physical experimental methods and mathematical calculation methods. The physical experimental method has poor repeatability, high cost and low research efficiency. For the mathematical calculation method, human bone tissue has complex geometric shapes and mechanical properties. Using traditional mathematical methods to calculate the mechanical properties of bone tissue not only makes the calculation process complicated, but also has large errors in the calculation results. As a numerical analysis method with a theoretical basis and wide application effectiveness, the finite element method can solve complex problems with irregular boundary conditions and structural shapes. The finite element method can simulate the complex shape of bone tissue well, give bone tissue different material properties, and apply various load conditions to bone tissue, so as to obtain more realistic calculation results. Before performing finite element calculations, the finite element model needs to be processed, that is, the process of modeling. How to establish a finite element model that is as realistic as possible is the key to the finite element method.

[0057] Existing finite element model building techniques usually include the following steps:

[0058] 1. First, use CT, MRI and other medical imaging data for three-dimensional reconstruction, mainly including grayscale threshold segmentation method and deep learning segmentation method, and then optimize the three-dimensional model, such as smoothing, filling, cleaning and other operations, to obtain a three-dimensional model of bone tissue that is more in line with the physiological morphology.

[0059] 2. Use 3D editing software such as Solidworks and UG (Unigraphics) to assemble bone tissue or simulate surgical operations, such as partial resection and assembly of medical devices.

[0060] 3. Divide the 3D model processed in step 2 into a grid using pre-processing software such as Hypermesh.

[0061] 4. Import the mesh data into finite element simulation software such as Ansys, Abaqus, etc., assign material properties to the finite element model, add loads and boundary conditions, and finally perform finite element analysis.

[0062] It should be understood that the existing finite element modeling method cannot establish a bone-anchor finite element model as accurate as the elbow joint model with anchors inserted in the exemplary embodiment of the present disclosure because it does not have a unified three-dimensional coordinate system. However, the exemplary embodiment of the present disclosure, on the basis of constructing and using a unified reference three-dimensional coordinate system, can still refer to the existing finite element modeling technology to perform assembly operations, meshing processing and mechanical analysis calculations on the model.

[0063] In step S105, according to the mechanical information corresponding to each of the multiple elbow joint models with the anchors placed, one is determined from multiple candidate placement directions corresponding to the multiple elbow joint models with the anchors placed as a preferred placement direction.

[0064] On the basis of constructing an elbow joint model with multiple anchors corresponding to multiple candidate insertion directions, the preferred insertion direction of the suture anchor is determined by analyzing the mechanical strength of the suture anchor at different insertion angles, which helps to reduce the occurrence of suture anchors penetrating cortical bone (bone includes cancellous bone located inside and cortical bone covered outside the cancellous bone), falling or entering the joint during surgery, and reduces the failure of surgery due to loosening, displacement, and extraction of suture anchors after surgery. The method disclosed in the present invention helps to achieve accurate preoperative planning, thereby improving the safety of elbow arthroscopic surgery, reducing the surgeon's dependence on arthroscopic surgery experience, and reducing medical costs.

[0065] It should be noted that each step in the exemplary embodiments of the present disclosure can be executed by manually operating software or by a computer calling software through an algorithm. These are all implementation methods of the present disclosure and fall within the protection scope of the present disclosure.

[0066] Next, the above step S102 is further introduced.

[0067] like Figure 2 As shown, the bones related to the elbow joint include the humerus 10, the radius 20 and the ulna 30. The structures on the humerus 10 mainly include the medial epicondyle 11, the lateral epicondyle 12, the capitellum 13 and the trochlea 14 of the humerus. The structures on the radius 20 mainly include the radial head 21 and the radial tuberosity 22. The structures on the ulna 30 mainly include the olecranon 31, the trochlea notch 32 and the coronoid process 33. The preset anatomical feature points can be selected from the anatomical feature points of these bone structures, such as the lowest point P of the trochlea ridge on the trochlea 14 of the humerus. Since the above structures mainly use the humerus 10 in the following text, and the focus of the present disclosure is on the method flow, the above structures will not be numbered in the following text.

[0068] Regarding the construction of the reference three-dimensional coordinate system, in principle, optionally, the preset anatomical feature points include the apex of the medial epicondyle, the apex of the lateral epicondyle, the lowest point of the trochlear crest, and the midpoint of the narrowest part of the distal humeral cortex. The execution principle of step S102 is to first determine the X-axis and then determine the Z-axis, specifically including: determining the straight line where the apex of the medial epicondyle and the apex of the lateral epicondyle are located as the X-axis of the reference three-dimensional coordinate system, determining the apex of the lateral epicondyle as the origin of the reference three-dimensional coordinate system, and determining the direction where the apex of the medial epicondyle is located as the positive direction of the X-axis; The plane perpendicular to the X-axis and passing through the lowest point of the trochlear crest is determined as the reference sagittal plane; the straight line parallel to the reference Z-axis line in the reference sagittal plane and passing through the origin is determined as the Z-axis of the reference three-dimensional coordinate system, and the straight line perpendicular to both the X-axis and the Z-axis is determined as the Y-axis of the reference three-dimensional coordinate system, wherein the reference Z-axis line is a straight line passing through the midpoint of the narrowest part of the distal humeral cortex in the reference sagittal plane and tangent to the innermost cortex of the humeral body; based on the right-hand rule, the positive directions of the Y-axis and the Z-axis are determined according to the positive direction of the X-axis. By first determining the X-axis and its positive direction based on the apex of the medial epicondyle and the apex of the lateral epicondyle, the extension direction of the sagittal plane perpendicular to the X-axis can be determined accordingly. On this basis, one of the countless sagittal planes perpendicular to the X-axis that passes through the lowest point of the trochlear crest is determined as the reference sagittal plane. The reference sagittal plane can pass through the humerus to form a clear section, and in this section, the cortical thickness of the distal humerus varies significantly. By taking the midpoint of the narrowest part of the distal humeral cortex in the reference sagittal plane as the reference and referring to the cortex of the humeral body, a straight line passing through the midpoint of the narrowest part of the distal humeral cortex and tangent to the innermost cortex of the humeral body can be determined. The direction of this straight line is determined as the reference Z-axis line, and the direction parallel to the extension direction of the Z-axis can be determined, thereby determining the Z-axis based on the position of the coordinate origin, and then determining the direction of the Y-axis and each axis, so as to achieve reliable construction of the reference three-dimensional coordinate system. The reference three-dimensional coordinate system finally determined using this principle is as follows: Figure 3 It should be noted that for the convenience of intuitive viewing, Figure 3 Only the positive half of the X, Y, and Z axes are drawn.

[0069] It should be understood that the core of the present disclosure is to use anatomical feature points as a reference to construct a reference three-dimensional coordinate system. In addition to the apex of the medial epicondyle, the apex of the lateral epicondyle, the lowest point of the trochlear crest, and the midpoint of the narrowest part of the distal humeral cortex given as examples here, other anatomical feature points can also be used as preset anatomical feature points, and a reliable reference three-dimensional coordinate system can be constructed accordingly, and the present disclosure does not limit this. In addition, these preset anatomical feature points can be marked manually or automatically by a computer through a reasonable algorithm, such as but not limited to the PCA (Principal Component Analysis) method based on point cloud and the deep learning method based on the UNet network, and the present disclosure does not limit this.

[0070] The implementation steps of marking the vertices of the medial and lateral epicondyles using the point cloud-based PCA method include, for example:

[0071] 1. Obtain point cloud data. This step uses the point cloud data of the distal end of the humerus to represent its surface shape.

[0072] 2. Perform PCA analysis. This step uses PCA to extract the principal axis direction of the point cloud data, and obtains the following three mutually perpendicular principal component vectors: the first principal component vector (denoted as PC1) is along the direction of the maximum variance of the data, that is, the direction of the humeral shaft (parallel to the Z axis); the second principal component vector (denoted as PC2) is perpendicular to PC1 and along the direction of the second largest variance, that is, the direction of the line connecting the vertices of the medial and lateral epicondyles (X axis direction); the third principal component vector (denoted as PC3) is perpendicular to the first two principal component vectors.

[0073] 3. Determine the feature points. In this step, all point clouds are projected onto the plane (coronal plane) formed by PC1 and PC2, and the two outermost points are the vertices of the medial and lateral epicondyles.

[0074] The implementation steps of marking the medial and lateral epicondyle vertices using the deep learning method based on the UNet network mainly include:

[0075] 1. Sample labeling: In this step, for each elbow joint 3D image data sample, the 3D coordinates of the medial epicondyle vertex and the lateral epicondyle vertex are manually labeled.

[0076] 2. Network design. This step uses the standard UNet network to extract features through downsampling (Encoder) and upsampling (Decoder) to reconstruct spatial information. The input of the network is a three-dimensional voxel, and the output is the position coordinates of the vertices of the medial epicondyle and the lateral epicondyle.

[0077] 3. Model training. In this step, the UNet network is trained using a supervised training method, and the loss function uses MSE (Mean Squared Error).

[0078] 4. Use the trained model to predict the coordinates of the medial and lateral epicondyle vertices.

[0079] For the several preset anatomical feature points and the corresponding coordinate construction principles shown above, appropriate operation steps may be flexibly selected when performing specific operations.

[0080] As an example, since the three-dimensional image data of the elbow joint can usually be viewed and processed in the medical image processing software, for example, including but not limited to using MPR (MultiPlanar Reconstruction, multi-planar reconstruction) technology to reconstruct the three-dimensional image data of the elbow joint, the three-dimensional image data of the elbow joint can be converted into a two-dimensional image displayed on three different planes: a horizontal plane (a plane that divides the human body into upper and lower parts), a coronal plane (a plane that divides the human body into front and back parts), and a sagittal plane (a plane that divides the human body into left and right parts). Based on this, these three types of planes can be translated and rotated in the medical image processing software to finally obtain the corresponding three planes that conform to the reference three-dimensional coordinate system, and then combined with the origin, the X-axis, and the direction of the X-axis to determine the reference three-dimensional coordinate system. Specifically, when the medical image processing software reconstructs the three-dimensional image data of the elbow joint, it will provide an original three-dimensional coordinate system, and the horizontal plane, the coronal plane, and the sagittal plane in the original three-dimensional coordinate system will be recorded as the original horizontal plane, the original coronal plane, and the original sagittal plane, respectively, and these three original planes can be translated and rotated when executing step S102.

[0081] Optionally, the operation of determining the plane perpendicular to the X-axis and passing through the lowest point of the trochlear crest as the reference sagittal plane in step S102 includes: translating and rotating the original coronal plane and the original horizontal plane to obtain an adjusted coronal plane, an adjusted horizontal plane and a corresponding adjusted sagittal plane, so that the intersection of the adjusted coronal plane and the adjusted horizontal plane coincides with the X-axis; in the adjusted coronal plane, translating the adjusted sagittal plane to pass through the lowest point of the trochlear crest to obtain a reference sagittal plane. This operation method can achieve rapid determination of the reference sagittal plane by first adjusting the original three planes based on the X-axis, and then translating the adjusted sagittal plane based on the three adjusted planes and the lowest point of the trochlear crest as a reference. It should be understood that the "corresponding adjusted sagittal plane" refers to a plane that is perpendicular to both the adjusted coronal plane and the adjusted horizontal plane. It should also be understood that when the sagittal plane is adjusted by translation, the coronal plane may be adjusted by translation synchronously or not, which does not affect the extension direction of the sagittal plane. The present disclosure does not limit this. Similar translation operations on one of the planes in the following text are the same and will not be explained one by one.

[0082] Optionally, in step S102, the straight line parallel to the reference Z axis line in the reference sagittal plane and passing through the origin is determined as the Z axis of the reference three-dimensional coordinate system, and the straight line perpendicular to both the X axis and the Z axis is determined as the Y axis of the reference three-dimensional coordinate system. The operation includes: in the reference sagittal plane, translating and rotating the adjusted coronal plane to obtain the reference coronal plane, so that the reference coronal plane passes through the midpoint of the narrowest part of the distal humeral cortex and is tangent to the innermost part of the cortex of the humeral body, and the adjusted horizontal plane is rotated accordingly to obtain the reference horizontal plane; translating the reference horizontal plane, the reference coronal plane, and the reference sagittal plane to intersect each other at the origin, using the intersection line obtained by translating the reference coronal plane and the reference sagittal plane as the Z axis, and determining the intersection line obtained by translating the reference horizontal plane and the reference sagittal plane as the Y axis. Since in the three-dimensional coordinate system, the straight line where the Z axis is located is the intersection line of the coronal plane and the sagittal plane, the projection straight line of the coronal plane in the sagittal plane can be used to represent the Z axis. Based on this, by implementing the determination operation of the reference Z axis as a translation and rotation operation of the adjustment coronal plane in the reference sagittal plane, the determination of the axis can be conveniently achieved through plane operation. Specifically, the adjustment coronal plane can be first translated to the midpoint passing through the narrowest part of the distal humeral cortex, and then the translated adjustment coronal plane can be rotated with this point as the center to be tangent to the innermost cortex of the humeral body. Similarly, the straight line where the Y axis is located is the intersection of the horizontal plane and the sagittal plane, and the horizontal plane needs to remain perpendicular to the coronal plane. Therefore, by making the adjustment horizontal plane rotate synchronously with the adjustment coronal plane and determining the Y axis accordingly, the determination of the axis can also be conveniently achieved through plane operation.

[0083] Next, combine Figures 4 to 9 A method for constructing a reference three-dimensional coordinate system according to a specific embodiment of the present disclosure is introduced.

[0084] The three-dimensional image data of the elbow joint in this specific embodiment is CT data, and the image reconstruction is realized by using the MPR technology, and the construction of the reference three-dimensional coordinate system is realized by translating and rotating the original three planes, wherein the original three planes are as follows: Figure 4 As shown, it is determined by the CT shooting angle. Figure 4 In the figure, the image in the upper left corner is the 2D image of the reconstructed image in the original horizontal plane, and the image in the lower left corner is the 2D image of the reconstructed image in the original coronal plane. Among these 2D images, the image in the upper right corner is the 2D image of the reconstructed image in the original sagittal plane. The red straight line, green straight line, and orange straight line represent the horizontal plane projection, the coronal plane projection, and the sagittal plane projection, respectively. In the 2D image of any plane, by translating and rotating the two straight lines in the figure, operations on the two planes corresponding to the two straight lines can be achieved, and the 2D image of the operated plane will change accordingly. Figures 5 to 9 Similarly, I will not explain them one by one.

[0085] First, through Figure 4The original horizontal plane (red straight line) and the original coronal plane (green straight line) in the image are translated and rotated so that the line connecting the vertices of the medial epicondyle and the lateral epicondyle is located on the intersection of the coronal plane and the horizontal plane, and the following is obtained: Figure 5 The adjusted horizontal plane (upper left corner), adjusted coronal plane (lower left corner), and adjusted sagittal plane (upper right corner) are shown, wherein the red marked points at the upper and lower parts of the adjusted horizontal plane are the apex of the lateral epicondyle and the apex of the medial epicondyle, respectively, the red marked points at the lower right and upper left parts of the adjusted coronal plane are the apex of the lateral epicondyle and the apex of the medial epicondyle, respectively, the line connecting the apex of the medial and lateral epicondyle is the X-axis, the apex of the lateral epicondyle is the origin, and the apex of the medial epicondyle is located on the positive side of the X-axis.

[0086] Second, in Figure 5 In the adjusted coronal plane (lower left corner) shown in the figure, the adjusted horizontal plane (red straight line) and the adjusted sagittal plane (orange straight line) are translated so that the intersection line of the horizontal plane and the sagittal plane (the intersection point of the red and orange straight lines) passes through the lowest point of the trochlear crest, as shown in FIG. Figure 6 As shown in the adjusted coronal plane in the lower left corner, the sagittal plane obtained at this time is the reference sagittal plane.

[0087] Third, in Figure 6 In the reference sagittal plane (upper right corner) shown in FIG. 1 , the adjusted horizontal plane (red straight line) and the adjusted coronal plane (green straight line) are translated so that the intersection of the horizontal plane and the coronal plane (the intersection of the red and green straight lines) passes through the midpoint of the narrowest part of the distal humeral cortex, as shown in FIG. Figure 7 The reference sagittal plane is shown in the upper right corner.

[0088] Fourth, in Figure 7 In the reference sagittal plane (upper right corner) shown, the translated coronal plane (green straight line) is rotated around the midpoint of the narrowest part of the distal humeral cortex so that it is tangent to the innermost cortex of the humeral body, as shown in Figure 2. Figure 8 As shown in the reference sagittal plane in the upper right corner, the horizontal plane and coronal plane obtained at this time are the reference horizontal plane and reference coronal plane, respectively.

[0089] Fifth, after determining the reference horizontal plane, reference coronal plane and reference sagittal plane, the extension direction of the coronal plane, sagittal plane and horizontal plane has been determined, and the intersection of the three planes will be used as the origin of the coordinate system. Therefore, it is only necessary to translate the three reference planes to modify the origin to the apex of the lateral epicondyle. The three planes of the reference three-dimensional coordinate system finally constructed are as follows: Fig. 9 shown.

[0090] Next, the above step S103 is further introduced.

[0091] Optionally, step S103 includes: constructing an elbow joint model based on the three-dimensional image data of the elbow joint; determining multiple candidate insertion directions based on the reference three-dimensional coordinate system; for each candidate insertion direction, constructing an elbow joint model with suture anchors inserted into the elbow joint model along the candidate insertion direction based on the suture anchor data, to obtain multiple elbow joint models with anchors inserted. The operations of constructing an elbow joint model and constructing an elbow joint model with anchors inserted for a specific candidate insertion direction may refer to existing finite element modeling technology to perform model assembly operations (for example, including but not limited to removing part of the bone tissue and inserting the suture anchors), meshing processing, and mechanical analysis calculations. The final constructed elbow joint model with anchors inserted is, for example, Fig.10 shown.

[0092] It should be noted that, as mentioned above, the three-dimensional image data of the elbow joint can be viewed and processed in the medical image processing software to realize the construction of the reference three-dimensional coordinate system, but the constructed coordinate system can usually only be viewed in the medical image processing software. In other words, the elbow joint model constructed based on the three-dimensional image data of the elbow joint may not have a coordinate system mark. Based on this, the coordinates of the key points of the reference three-dimensional coordinate system can be marked in the medical image processing software. The key points include, for example, but are not limited to the vertices of the medial epicondyle and the vertices of the lateral epicondyle (used to determine the origin, the X-axis, and the positive direction of the X-axis), and any two points on the Z-axis or the Y-axis (used to determine the Z-axis or the Y-axis). As long as they can be used to determine the reference three-dimensional coordinate system, when constructing the elbow joint model, these key points can be used to re-determine the reference three-dimensional coordinate system in the model.

[0093] It should be understood that since the difference between different elbow joint models for implanting anchors mainly lies in the use of different candidate implantation directions, the focus of step S103 is on how to determine multiple candidate implantation directions. Specifically, the reference three-dimensional coordinate system includes mutually perpendicular horizontal planes, coronal planes, and sagittal planes, the intersection of the horizontal plane and the coronal plane is the X-axis of the reference three-dimensional coordinate system, the intersection of the horizontal plane and the sagittal plane is the Y-axis of the reference three-dimensional coordinate system, and the intersection of the coronal plane and the sagittal plane is the Z-axis of the reference three-dimensional coordinate system.

[0094] In some embodiments, optionally, the operation of determining multiple candidate implantation directions based on the reference three-dimensional coordinate system includes: determining multiple candidate implantation directions in the horizontal plane of the reference three-dimensional coordinate system, and / or determining multiple candidate implantation directions in the coronal plane of the reference three-dimensional coordinate system, to obtain multiple candidate implantation directions. Figure 3 In the embodiment of the reference three-dimensional coordinate system shown, since the suture anchor needs to be placed in the humerus, and the sagittal plane perpendicular to the X-axis has only one intersection with the humerus, which is the vertex of the medial epicondyle, there is no need to determine the candidate placement direction in the sagittal plane.

[0095] In other embodiments, optionally, based on the reference three-dimensional coordinate system, the operation of determining multiple candidate insertion directions includes: determining multiple candidate insertion directions in the three-dimensional space described by the reference three-dimensional coordinate system. By determining the candidate insertion directions in the three-dimensional space rather than only in the two-dimensional plane, a richer and more accurate description of the insertion directions can be achieved, which helps to achieve accurate preoperative planning, thereby improving the safety of elbow arthroscopy.

[0096] In some other embodiments described above, optionally, the operation of determining a plurality of candidate placement directions in the three-dimensional space described by the reference three-dimensional coordinate system includes: referring to Figure 3 , rotating the horizontal plane (i.e., XOY plane) around the Y axis by multiple first preset angles to obtain multiple rotated horizontal planes, rotating the coronal plane (i.e., XOZ plane) around the Z axis by multiple second preset angles to obtain multiple rotated coronal planes; determining the direction of the intersection of a rotated horizontal plane and a rotated coronal plane as a candidate implantation direction, and determining multiple candidate implantation directions based on the multiple rotated horizontal planes and the multiple rotated coronal planes. By first determining multiple rotated horizontal planes (equivalent to determining multiple implantation directions in the coronal plane) and multiple rotated coronal planes (equivalent to determining multiple implantation directions in the horizontal plane), and combining the multiple rotated horizontal planes with the multiple rotated coronal planes in pairs, it is equivalent to taking the direction represented by the vector sum of the unit vector of an implantation direction in the coronal plane and the unit vector of an implantation direction in the horizontal plane as a candidate implantation direction, and multiple candidate implantation directions in three-dimensional space (the number of which is the product of the number of rotated horizontal planes and the number of rotated coronal planes) can be clearly obtained.

[0097] Optionally, refer to Figure 3 The reference three-dimensional coordinate system shown in FIG. 1 is a reference three-dimensional coordinate system, the origin of which is located on one side of the distal end of the humerus (e.g., the apex of the lateral epicondyle described above), the positive direction of the Z axis is from the distal end of the humerus to the proximal end of the humerus, and the X axis runs transversely through the humerus, and the positive direction of the X axis is from one side of the humerus to the other side of the humerus. For the first preset angle, Fig.11 As shown, the angle of rotation of the horizontal plane around the Y-axis toward the positive direction close to the Z-axis is positive, and multiple first preset angles are all positive angles, so that the insertion direction pointing to the inside of the humerus can be determined in the coronal plane. For the second preset angle, the multiple second preset angles include 0, positive angles and negative angles. Since the coronal plane traverses the humerus, no matter which direction it deflects in the horizontal plane, it can point to the inside of the humerus, so that the insertion direction pointing to the inside of the humerus can be determined in the horizontal plane. Of course, the specific absolute value of the angle needs to be reasonably determined to ensure that the insertion direction points to the inside of the humerus. As an example, Fig.11 As shown, the first preset angles include 15°, 30°, and 45°. Fig.12As shown, the multiple second preset angles include -10°, 0°, and 10°, that is, the initial coronal plane before the rotation of the reference three-dimensional coordinate system is also used as a rotated coronal plane, while the initial horizontal plane before the rotation is not used as a rotated horizontal plane.

[0098] Next, a method for determining the insertion direction of an elbow joint suture anchor according to a specific embodiment of the present disclosure is introduced. This specific embodiment does not separately describe the step of initially acquiring data (ie, step S101).

[0099] Step 1: construct a unified reference three-dimensional coordinate system of the distal humerus based on the medical image data (corresponding to the operation of obtaining three-dimensional image data of the elbow joint in S101 and step S102).

[0100] The target patient's elbow joint CT image data is obtained based on the computed tomography image as the elbow joint three-dimensional image data, and the data format is DICOM format. Then, the elbow joint three-dimensional image data in DICOM format is imported into the medical image processing software MIMICS21.0 for processing.

[0101] During the processing, the three-dimensional image of the elbow joint was first reconstructed by MPR, and the line connecting the vertices of the medial and lateral epicondyles was selected as the X-axis (the vertices of the lateral epicondyle were the origin, and the vertices of the medial epicondyle were located on the positive side of the X-axis); the original coronal plane, the original horizontal plane, and the original sagittal plane were translated and rotated to obtain the adjusted coronal plane, the adjusted horizontal plane, and the adjusted sagittal plane, so that the line connecting the vertices of the medial and lateral epicondyles was located on the intersection of the adjusted coronal plane and the adjusted horizontal plane; the adjusted sagittal plane was moved to the lowest point of the trochlear crest in the adjusted coronal plane to obtain the reference sagittal plane; the adjusted coronal plane was first moved to the lowest point of the trochlear crest in the reference sagittal plane The midpoint of the narrowest part of the distal cortex of the humerus is then rotated around the midpoint of the narrowest part of the distal cortex of the humerus to be tangent to the innermost cortex of the humeral body to obtain the reference coronal plane and the corresponding reference horizontal plane; the three reference planes are moved to intersect at the apex of the lateral epicondyle (i.e., the origin) to obtain the three planes of the reference three-dimensional coordinate system; the intersection of the horizontal plane and the sagittal plane is determined as the Y axis of the reference three-dimensional coordinate system, and the intersection of the coronal plane and the sagittal plane is determined as the Z axis of the reference three-dimensional coordinate system; based on the right-hand rule, the positive direction of the Y axis and the positive direction of the Z axis are determined according to the positive direction of the X axis to establish a reference three-dimensional coordinate system. For detailed process, please refer to the above and Figures 3 to 9 .

[0102] After the establishment is completed, the coordinates of the medial epicondyle vertex, the lateral epicondyle vertex and two arbitrary points on the Z axis (as key points) in the reference three-dimensional coordinate system are recorded.

[0103] Step 2: construct a three-dimensional model of the distal humerus based on the medical imaging data as an elbow joint model for inserting multiple anchors (corresponding to the operation of obtaining suture anchor data in step S101 and step S103).

[0104] First, the bones are segmented and masks are generated according to the CT grayscale. Then, the edge contours of the bones are filled and cleaned to obtain a bone mask with a clear contour boundary. Finally, the bone mask is smoothed and the processed mask is used to output a triangular mesh file in STL (Stereolithography) format.

[0105] Since the triangular mesh is too fine, it is not conducive to the subsequent meshing of the bone surface. Therefore, the reverse modeling software Geomagic needs to be used to re-mesh the STL file, and the smoothing function in the software is used to further smooth the bone surface. Then, the offset function is used to offset inward to form a cancellous bone surface. The unoffset bone is used as the cortical bone model. Finally, the offset file and the unoffset file are output in STP format respectively. The specific offset is the thickness of the cortical bone near the lateral epicondyle of the target patient's humerus measured by CT images.

[0106] Then import the cortical bone model into SolidWorks, create a reference 3D coordinate system based on the key coordinate points in step 1, and use the newly created reference 3D coordinate system as the global coordinate system. Based on the surgical experience of elbow arthroscopy, preliminarily determine the insertion point of the suture anchor, and use the 3D sketch function to mark the anchor insertion point. Figure 3 It is a three-dimensional model of cortical bone. The three straight lines represent the three coordinate axes after reconstruction. The point above the coordinate origin is the insertion point of the suture anchor. Then, a series of rotational horizontal planes and rotational coronal planes are generated based on the horizontal plane and the coronal plane to facilitate the simulation of the candidate insertion directions of the suture anchor. This specific embodiment uses 9 directions as candidate insertion directions based on surgical experience. Reference Figure 3 , the positive and negative directions of the Y axis are called the front side and the rear side respectively, and the positive and negative directions of the Z axis are called the bottom side and the top side respectively. Fig.11 As shown in the figure, the projection of the horizontal plane on the coronal plane is observed from the front, and the horizontal plane is rotated clockwise by 15°, 30°, and 45°, that is, the horizontal plane is rotated 15°, 30°, and 45° around the Y axis toward the positive direction of the Z axis to obtain three rotated horizontal planes. Fig.12 As shown in the figure, the projection of the coronal plane on the horizontal plane is observed from the upper side. With clockwise rotation as positive, the coronal plane is rotated by -10°, 0°, and 10°, that is, the coronal plane is rotated 10° in two opposite directions around the Z axis, and then the coronal plane itself is added to obtain three rotated coronal planes. The three rotated horizontal planes and the three rotated coronal planes are combined in pairs, and the angle line between a rotated horizontal plane and a rotated coronal plane is used as a candidate implantation direction, resulting in nine candidate implantation directions.

[0107] Finally, the cortical bone, cancellous bone and anchor model (constructed according to the suture anchor data) are imported into the assembly drawing of SolidWorks, the cortical bone and cancellous bone are assembled, and then the relevant coordination between the suture anchor and the humerus is set. The insertion point of the suture anchor needs to be collinear with the axis of the suture anchor, and the axis of the suture anchor needs to be in the candidate insertion direction. After the coordination is completed, the three-dimensional model is checked. If the suture anchor pierces the cortex in the model of a candidate insertion direction, the insertion point of the suture anchor in the model needs to be corrected and moved 2mm in the negative direction of the Y axis. If the suture anchor still pierces the cortex after the movement, continue to move until the suture anchor is normally inserted into the cancellous bone. After the assembly is completed, save it as an SLDASM (SolidWorks software file extension, representing SolidWorks Assembly) file. Fig.10 It is the assembled model, including cortical bone, cancellous bone and suture anchors.

[0108] Step 3: Perform finite element analysis calculation on the constructed model (corresponding to step S104).

[0109] 1) Divide the finite element mesh based on the three-dimensional model of the distal humerus.

[0110] Use the finite element pre-processing software Hypermesh to divide the mesh and import the assembly file in step 2. First, perform geometric cleaning, remove small features, and repair missing geometric lines. Then perform Boolean operations on the bones and suture anchors to prevent interference. Use tetrahedral meshes to divide the model into finite element meshes. Use 0.1mm meshes for the suture anchor part and 0.1-10mm meshes for the humerus part. After meshing, output the INP (Input) format files of the cortical bone, cancellous bone, and suture anchor respectively, and then use Abaqus for finite element analysis. Fig.13 It is the finite element mesh after dividing the tetrahedral units, which includes three parts: cortical bone, cancellous bone and suture anchor.

[0111] 2) Establish a finite element model based on the anchor-humerus connection relationship.

[0112] The finite element model was established using the finite element analysis software Abaqus, and the INP file generated in the previous step was imported. Different material properties were assigned to the cortical bone, cancellous bone, and suture anchor. According to the suture anchor data, the elastic modulus of the suture anchor was set to 200 MPa and the Poisson's ratio was set to 0.35, and the elastic modulus of the cortical bone was set to 80 MPa and the Poisson's ratio was set to 0.3, and the elastic modulus of the cancellous bone was set to 2 MPa and the Poisson's ratio was set to 0.26. A tensile force of 100 N was applied in the axial direction of the suture anchor to simulate the traction force of the suture during surgery.

[0113] After completing the modeling, finite element calculation is performed, and the calculation results of Abaqus are recorded to obtain the mechanical information corresponding to multiple candidate insertion directions.

[0114] Step 4: Select the preferred placement direction based on the finite element analysis results.

[0115] This specific embodiment uses the maximum stress of the suture anchor as a reference value. The maximum stress can reflect the stress distribution around the thread of the suture anchor. Small stress is more conducive to the fixation of the anchor. Therefore, the direction with the smallest maximum stress value is selected from the 9 candidate insertion directions as the preferred insertion direction for preoperative planning.

[0116] This specific embodiment uses MIMICS software to perform MPR reconstruction on CT images, establishes a reference three-dimensional coordinate system based on the preset anatomical feature points of the humerus, and records the coordinates of the key points. The 3D sketch function is used in SoldiesWorks to restore the key points, thereby reconstructing a unified distal humerus coordinate system, so that the insertion point and insertion direction of the suture anchor can be more conveniently described, which is convenient for optimizing elbow arthroscopic surgery. And the unified coordinate system between different individual samples is conducive to studying more general biological laws. In addition, this specific embodiment uses the finite element method to calculate and solve the anchor-humerus finite element model, by establishing a finite element model of different insertion directions of the suture anchor, analyzing the mechanical strength of the suture anchor in different insertion directions, and determining the preferred insertion direction of the suture anchor according to the value of the maximum stress of the thread of the suture anchor, which helps to achieve accurate preoperative planning, reduce the occurrence of suture anchors penetrating cortical bones, falling or entering joints during surgery, and reduce the failure of surgery due to loosening, displacement, and extraction of anchors after surgery. This method can not only improve the safety of elbow arthroscopic surgery, but also reduce the surgeon's dependence on arthroscopic surgical experience and reduce medical costs.

[0117] Fig.14 is a block diagram of a device for determining an elbow joint suture anchor placement direction according to an exemplary embodiment of the present disclosure. Fig.14 The device 1400 for determining the insertion direction of an elbow joint suture anchor comprises an acquisition unit 1401 , a coordinate construction unit 1402 , a model construction unit 1403 , a calculation unit 1404 , and a determination unit 1405 .

[0118] The acquisition unit 1401 may acquire the three-dimensional image data and suture anchor data of the target patient's elbow joint.

[0119] The coordinate construction unit 1402 may construct a reference three-dimensional coordinate system based on preset anatomical feature points in the three-dimensional image data of the elbow joint.

[0120] The model construction unit 1403 can construct multiple elbow joint models with inserted anchors according to the reference three-dimensional coordinate system based on the elbow joint three-dimensional image data and the suture anchor data, wherein each elbow joint model with inserted anchors is used to represent the insertion of the suture anchor into the elbow joint of the target patient along a candidate insertion direction, and the multiple elbow joint models with inserted anchors correspond one-to-one to the multiple candidate insertion directions.

[0121] The calculation unit 1404 may perform mechanical analysis calculations on the elbow joint models with multiple anchor pins inserted respectively to obtain mechanical information corresponding to each elbow joint model with each anchor pin inserted.

[0122] The determination unit 1405 may determine one of the multiple candidate placement directions corresponding to the multiple elbow joint models with the anchors placed therein as the preferred placement direction according to the mechanical information corresponding to each of the multiple elbow joint models with the anchors placed therein.

[0123] Optionally, the preset anatomical feature points include the apex of the medial epicondyle, the apex of the lateral epicondyle, the lowest point of the trochlear ridge, and the midpoint of the narrowest part of the distal humeral cortex. The coordinate construction unit 1402 can also: determine the straight line where the line connecting the apex of the medial epicondyle and the apex of the lateral epicondyle is located as the X-axis of the reference three-dimensional coordinate system, determine the apex of the lateral epicondyle as the origin of the reference three-dimensional coordinate system, and determine the direction where the apex of the medial epicondyle is located as the positive direction of the X-axis; determine the plane perpendicular to the X-axis and passing through the lowest point of the trochlear ridge as the reference sagittal plane; determine the straight line parallel to the reference Z-axis line in the reference sagittal plane and passing through the origin as the Z-axis of the reference three-dimensional coordinate system, and determine the straight line perpendicular to both the X-axis and the Z-axis as the Y-axis of the reference three-dimensional coordinate system, wherein the reference Z-axis line is a straight line in the reference sagittal plane that passes through the midpoint of the narrowest part of the distal humeral cortex and is tangent to the innermost side of the cortex of the humeral body; based on the right-hand rule, determine the positive directions of the Y-axis and the Z-axis according to the positive direction of the X-axis.

[0124] Optionally, the original three-dimensional coordinate system in the three-dimensional image data of the elbow joint includes an original horizontal plane, an original coronal plane, and an original sagittal plane. The coordinate construction unit 1402 can also: translate and rotate the original coronal plane and the original horizontal plane to obtain an adjusted coronal plane, an adjusted horizontal plane, and a corresponding adjusted sagittal plane, so that the intersection of the adjusted coronal plane and the adjusted horizontal plane coincides with the X-axis; translate the adjusted sagittal plane in the adjusted coronal plane to pass through the lowest point of the trochlear crest to obtain a reference sagittal plane; and in the reference sagittal plane , translate and rotate the adjusted coronal plane to obtain the reference coronal plane, so that the reference coronal plane passes through the midpoint of the narrowest part of the distal humeral cortex and is tangent to the innermost cortex of the humeral body, and rotate the adjusted horizontal plane accordingly to obtain the reference horizontal plane; translate the reference horizontal plane, the reference coronal plane, and the reference sagittal plane to intersect each other at the origin, and use the intersection line of the reference coronal plane and the reference sagittal plane after translation as the Z axis, and determine the intersection line of the reference horizontal plane and the reference sagittal plane after translation as the Y axis.

[0125] Optionally, the model construction unit 1403 can also: construct an elbow joint model based on the three-dimensional image data of the elbow joint; determine multiple candidate insertion directions in the three-dimensional space described by the reference three-dimensional coordinate system; for each candidate insertion direction, based on the suture anchor data, construct an elbow joint model in which the suture anchor is inserted into the elbow joint model along the candidate insertion direction, to obtain multiple elbow joint models with the anchor inserted.

[0126] Optionally, the reference three-dimensional coordinate system includes a horizontal plane, a coronal plane, and a sagittal plane that are perpendicular to each other, the intersection line of the horizontal plane and the coronal plane is the X-axis of the reference three-dimensional coordinate system, the intersection line of the horizontal plane and the sagittal plane is the Y-axis of the reference three-dimensional coordinate system, and the intersection line of the coronal plane and the sagittal plane is the Z-axis of the reference three-dimensional coordinate system. The model building unit 1403 can also: rotate the horizontal plane around the Y-axis by multiple first preset angles to obtain multiple rotated horizontal planes, and rotate the coronal plane around the Z-axis by multiple second preset angles to obtain multiple rotated coronal planes; determine the direction of the intersection line of a rotated horizontal plane and a rotated coronal plane as a candidate implantation direction, and determine multiple candidate implantation directions based on the multiple rotated horizontal planes and the multiple rotated coronal planes.

[0127] Optionally, the positive direction of the Z axis is the direction from the distal end of the humerus to the proximal end of the humerus, and the angle of rotation of the horizontal plane around the Y axis toward the positive direction close to the Z axis is positive, and multiple first preset angles are all positive angles; multiple second preset angles include 0, positive angles and negative angles.

[0128] Regarding the device in the above embodiment, the specific manner in which each unit performs the operation has been described in detail in the embodiment of the method, and will not be elaborated here.

[0129] Fig.15 A structural block diagram of an electronic device 1500 according to an exemplary embodiment of the present disclosure is shown.

[0130] Reference Fig.15 The electronic device 1500 includes: at least one memory 1501 and at least one processor 1502, wherein the at least one memory 1501 stores computer executable instructions, and when the computer executable instructions are executed by the at least one processor 1502, the at least one processor is prompted to execute the target corresponding method as described in the above exemplary embodiment.

[0131] As an example, the electronic device 1500 may be a PC, a tablet device, a personal digital assistant, a smart phone, or other device capable of executing the above instruction set. Here, the electronic device 1500 is not necessarily a single electronic device 1500, but may also be any device or circuit capable of executing the above instruction (or instruction set) individually or in combination. The electronic device 1500 may also be part of an integrated control system or system manager, or may be configured as a portable electronic device 1500 that is interconnected with a local or remote (e.g., via wireless transmission) interface.

[0132] In the electronic device 1500, the processor 1502 may include a central processing unit (CPU), a graphics processing unit (GPU), a programmable logic device, a dedicated processor system, a microcontroller or a microprocessor. As an example and not limitation, the processor 1502 may also include an analog processor, a digital processor, a microprocessor, a multi-core processor, a processor array, a network processor, etc.

[0133] The processor 1502 may execute instructions or codes stored in the memory 1501, wherein the memory 1501 may also store data. Instructions and data may also be sent and received over a network via a network interface device, wherein the network interface device may employ any known transmission protocol.

[0134] The memory 1501 may be integrated with the processor 1502, for example, by placing RAM or flash memory within an integrated circuit microprocessor or the like. In addition, the memory 1501 may include a separate device, such as an external disk drive, a storage array, or any other storage device that can be used by a database system. The memory 1501 and the processor 1502 may be operatively coupled, or may communicate with each other, such as through an I / O port, a network connection, etc., so that the processor 1502 can read files stored in the memory.

[0135] In addition, the electronic device 1500 may further include a video display (such as a liquid crystal display) and a user interaction interface (such as a keyboard, a mouse, a touch input device, etc.) All components of the electronic device 1500 may be connected to each other via a bus and / or a network.

[0136] According to an exemplary embodiment of the present disclosure, a computer-readable storage medium storing instructions may also be provided, wherein the instructions, when executed by at least one processor, cause the at least one processor to execute the target corresponding method as described in the above exemplary embodiment. Examples of computer-readable storage media here include: read-only memory (ROM), random access programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, non-volatile memory, CD-ROM, CD-R, CD+R, CD-RW, CD+RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM, BD-ROM, BD-R, BD-R LTH, BD-RE, Blu-ray or optical disk storage, hard disk drive (HDD), solid state drive (SSD), card storage (such as, multimedia card, secure digital (SD) card or extreme digital (XD) card), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid state disk and any other device, any other device is configured to store computer programs and any associated data, data files and data structures in a non-transitory manner and provide the computer programs and any associated data, data files and data structures to a processor or computer so that the processor or computer can execute the computer program. The computer program in the above-mentioned computer-readable storage medium can be run in an environment deployed in a computer device such as a client, a host, an agent device, a server, etc. In addition, in one example, the computer program and any associated data, data files and data structures are distributed on a networked computer system, so that the computer program and any associated data, data files and data structures are stored, accessed and executed in a distributed manner by one or more processors or computers.

[0137] According to an exemplary embodiment of the present disclosure, a computer program product may also be provided, including computer instructions, which, when executed by at least one processor, execute the target corresponding method as described in the above exemplary embodiment.

[0138] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. The present disclosure is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

[0139] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method for determining the insertion direction of an elbow joint suture anchor, characterized in that: The determination method comprises: Acquire three-dimensional image data of the elbow joint and suture anchor data of the target patient; Constructing a reference three-dimensional coordinate system based on preset anatomical feature points in the three-dimensional image data of the elbow joint; Based on the elbow joint three-dimensional image data and the suture anchor data, constructing a plurality of elbow joint models with anchor placement according to the reference three-dimensional coordinate system, wherein each elbow joint model with anchor placement is used to represent that a suture anchor is placed into the elbow joint of the target patient along a candidate placement direction, and the plurality of elbow joint models with anchor placement correspond one-to-one to the plurality of candidate placement directions; Performing mechanical analysis and calculation on the elbow joint models with the plurality of anchor pins inserted respectively to obtain mechanical information corresponding to each elbow joint model with the anchor pins inserted; According to the mechanical information corresponding to each of the plurality of elbow joint models with the anchors placed, one is determined from the plurality of candidate placement directions corresponding to the plurality of elbow joint models with the anchors placed as a preferred placement direction.

2. The determination method according to claim 1, characterized in that: The preset anatomical feature points include the apex of the medial epicondyle, the apex of the lateral epicondyle, the lowest point of the trochlear crest, and the midpoint of the narrowest part of the distal humeral cortex. The construction of a reference three-dimensional coordinate system based on the preset anatomical feature points in the three-dimensional image data of the elbow joint includes: Determine the straight line where the medial epicondyle vertex and the lateral epicondyle vertex are connected as the X-axis of the reference three-dimensional coordinate system, determine the lateral epicondyle vertex as the origin of the reference three-dimensional coordinate system, and determine the direction where the medial epicondyle vertex is located as the positive direction of the X-axis; Determine a plane perpendicular to the X-axis and passing through the lowest point of the trochlear crest as a reference sagittal plane; A straight line parallel to the reference Z axis in the reference sagittal plane and passing through the origin is determined as the Z axis of the reference three-dimensional coordinate system, and a straight line perpendicular to both the X axis and the Z axis is determined as the Y axis of the reference three-dimensional coordinate system, wherein the reference Z axis is a straight line in the reference sagittal plane that passes through the midpoint of the narrowest part of the distal humeral cortex and is tangent to the innermost side of the cortex of the humeral body; Based on the right-hand rule, the positive directions of the Y axis and the Z axis are determined according to the positive direction of the X axis.

3. The determination method according to claim 2, characterized in that: The original three-dimensional coordinate system in the three-dimensional image data of the elbow joint includes an original horizontal plane, an original coronal plane and an original sagittal plane. Wherein, determining a plane perpendicular to the X-axis and passing through the lowest point of the trochlear crest as a reference sagittal plane comprises: The original coronal plane and the original horizontal plane are translated and rotated to obtain an adjusted coronal plane, an adjusted horizontal plane and a corresponding adjusted sagittal plane, so that the intersection line of the adjusted coronal plane and the adjusted horizontal plane coincides with the X-axis; In the adjusted coronal plane, translating the adjusted sagittal plane to pass through the lowest point of the trochlear crest to obtain the reference sagittal plane; The method of determining a straight line parallel to the reference Z axis in the reference sagittal plane and passing through the origin as the Z axis of the reference three-dimensional coordinate system, and determining a straight line perpendicular to both the X axis and the Z axis as the Y axis of the reference three-dimensional coordinate system, includes: In the reference sagittal plane, the adjustment coronal plane is translated and rotated to obtain a reference coronal plane, so that the reference coronal plane passes through the midpoint of the narrowest part of the distal humeral cortex and is tangent to the innermost part of the cortex of the humeral body, and the adjustment horizontal plane is rotated accordingly to obtain a reference horizontal plane; The reference horizontal plane, the reference coronal plane and the reference sagittal plane are translated until they intersect each other at the origin, the intersection line of the reference coronal plane and the reference sagittal plane after translation is determined as the Z axis, and the intersection line of the reference horizontal plane and the reference sagittal plane after translation is determined as the Y axis.

4. The determination method according to any one of claims 1 to 3, characterized in that: The step of constructing a plurality of elbow joint models with anchors inserted according to the reference three-dimensional coordinates based on the elbow joint three-dimensional image data and the suture anchor data comprises: constructing an elbow joint model based on the three-dimensional image data of the elbow joint; Determining the plurality of candidate placement directions in the three-dimensional space described by the reference three-dimensional coordinate system; For each candidate placement direction, based on the suture anchor data, an elbow joint model of the suture anchor placed in the elbow joint model along the candidate placement direction is constructed to obtain the plurality of elbow joint models of the suture anchor placed.

5. The determination method according to claim 4, characterized in that: The reference three-dimensional coordinate system includes a horizontal plane, a coronal plane, and a sagittal plane that are perpendicular to each other, the intersection of the horizontal plane and the coronal plane is the X-axis of the reference three-dimensional coordinate system, the intersection of the horizontal plane and the sagittal plane is the Y-axis of the reference three-dimensional coordinate system, and the intersection of the coronal plane and the sagittal plane is the Z-axis of the reference three-dimensional coordinate system, wherein determining the multiple candidate implantation directions in the three-dimensional space described by the reference three-dimensional coordinate system includes: The horizontal plane is rotated around the Y axis by a plurality of first preset angles to obtain a plurality of rotated horizontal planes, and the coronal plane is rotated around the Z axis by a plurality of second preset angles to obtain a plurality of rotated coronal planes; The direction of the intersection line of a rotational horizontal plane and a rotational coronal plane is determined as a candidate implantation direction, and the plurality of candidate implantation directions are determined based on the plurality of rotational horizontal planes and the plurality of rotational coronal planes.

6. The determination method according to claim 5, characterized in that: The positive direction of the Z axis is the direction from the distal end of the humerus to the proximal end of the humerus, and the angle of rotation of the horizontal plane around the Y axis toward the positive direction close to the Z axis is positive, and the multiple first preset angles are all positive angles; The plurality of second preset angles include 0, a positive angle and a negative angle.

7. A device for determining the insertion direction of an elbow joint suture anchor, characterized in that: The determining device comprises: an acquisition unit configured to acquire three-dimensional image data of an elbow joint and suture anchor data of a target patient; A coordinate construction unit configured to construct a reference three-dimensional coordinate system based on preset anatomical feature points in the three-dimensional image data of the elbow joint; a model construction unit configured to construct a plurality of elbow joint models with anchors placed according to the reference three-dimensional coordinate system based on the elbow joint three-dimensional image data and the suture anchor data, wherein each elbow joint model with anchors placed is used to represent placing a suture anchor into the elbow joint of the target patient along a candidate placement direction, and the plurality of elbow joint models with anchors placed correspond one-to-one to the plurality of candidate placement directions; a calculation unit configured to perform mechanical analysis calculations on the plurality of elbow joint models with anchor pins inserted respectively, to obtain mechanical information corresponding to each elbow joint model with anchor pins inserted; The determination unit is configured to determine one of the multiple candidate insertion directions corresponding to the multiple elbow joint models with the multiple anchors inserted as a preferred insertion direction according to the mechanical information corresponding to each of the multiple elbow joint models with the multiple anchors inserted.

8. An electronic device, characterized in that: include: at least one processor; at least one memory storing computer executable instructions, Wherein, when the computer executable instructions are executed by the at least one processor, the at least one processor is prompted to execute the method for determining the insertion direction of the elbow joint suture anchor according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: When the instructions in the computer-readable storage medium are executed by at least one processor, the at least one processor is prompted to perform the method for determining the placement direction of an elbow joint suture anchor according to any one of claims 1 to 6.

10. A computer program product comprising computer instructions, characterized in that: When the computer instructions are executed by at least one processor, the at least one processor is prompted to perform the method for determining the placement direction of the elbow joint suture anchor according to any one of claims 1 to 6.

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