A method for determining an outside ankle nail placement path and a guide plate preparation method

Abstract

This invention discloses a method for determining the placement path of the lateral ankle pin and a method for preparing a guide plate. The determination method includes: acquiring an image sequence of the ankle joint; based on the analysis of the image sequence of the ankle joint, identifying and determining the talus, fibula, and outer contour of the skin, and constructing an ankle joint solid model; based on the ankle joint solid model, performing positional analysis on the fibula to determine the unnamed tubercle of the fibula and establishing a pin placement point; combining the ankle joint solid model and the pin placement point, performing positional analysis on the talus to determine the parallel plane of the lateral surface of the talus and providing an initial rotation reference line; updating the initial rotation reference line in the parallel plane of the lateral surface of the talus according to the pin placement point and a preset standard angle, and providing a rotation reference line; based on the rotation reference line, providing a first pin placement reference line, determining the lateral ankle pin placement path, achieving precise determination of the anchoring position, and ensuring the accuracy of pin placement.

Description

Technical Field

[0001] This invention belongs to the technical field of image data processing, specifically relating to a method for determining the path of lateral ankle nail placement and a method for preparing a guide plate. Background Technology

[0002] With the continuous advancement of medical imaging and instrument technology, guide plate design is increasingly being combined with medical imaging data to assist surgeons or other healthcare providers in performing surgical procedures.

[0003] In orthopedic surgery, it is often necessary to embed anchors into the bone. Guide plates help surgeons precisely position the bone during surgery. Currently, there is much research on guide plates for the spine, pelvis, and joints, but they are mostly used for joint replacement, osteotomy, or fracture fixation. Research on guide plates for ligament repair, especially ankle ligaments, has limited value. For ankle ligament repair guide plates, due to the complex structure of the ankle joint and the limited operating space, extremely precise positioning is required; even slight deviations can affect the surgical outcome.

[0004] Patent CN107260306A discloses a method for planning screw placement in a three-dimensional simulated surgery and a surgical simulator. The method includes: creating a three-dimensional model based on received CT images of the spine; generating three cross-sectional views from the three-dimensional model; displaying the three-dimensional model and the three cross-sectional views; adjusting the position and direction of the cross-sections to visually observe the cross-sectional condition of the spine; determining the screw path through the intersection of the cross-sections in two directions; adding a screw to the determined path; and moving the screw along the path to position it in the actual surgical position, thus completing the screw planning. This method offers simple and convenient planning, allowing for more precise screw path planning and making screw placement safer and more reliable.

[0005] Including the techniques mentioned above, most current surgical pin placement methods focus on bone structures such as the spine and pelvis, and there are no pin placement methods specifically for the bone structures of the lateral ankle in lateral malleolar anterior talofibular ligament repair surgery. Summary of the Invention

[0006] To address the shortcomings of the existing technologies, this invention provides a method for determining the lateral ankle pin placement path and a guide plate preparation method. The method includes acquiring an image sequence of the ankle joint; based on the analysis of the ankle joint image sequence, identifying and determining the talus, fibula, and outer skin contour entities, and constructing an ankle joint entity model; based on the ankle joint entity model, performing positional analysis on the fibula entity, determining the unnamed tubercle of the fibula, and establishing a pin placement point; combining the ankle joint entity model and the pin placement point, performing positional analysis on the talus entity, determining the parallel plane of the lateral surface of the talus, and providing an initial rotation reference line; updating the initial rotation reference line in the parallel plane of the lateral surface of the talus according to the pin placement point and a preset standard angle, and providing a rotation reference line; based on the rotation reference line, providing a first pin placement reference line, and determining the lateral ankle pin placement path.

[0007] By analyzing image sequences of the ankle joint, a solid model of the ankle joint is constructed. Positional analysis of the fibula and talus is performed to establish pin placement points and determine the parallel plane of the lateral surface of the talus. An initial rotation reference line is given, and combined with a preset standard angle, the initial rotation reference line is updated in the parallel plane of the lateral surface of the talus, thus determining the pin placement path of the lateral ankle. By combining inertial axis fitting and plane fitting, the problem of pin placement angle dependence on experience in traditional methods is solved, providing a repeatable and verifiable geometric method for pin placement location determination.

[0008] In a first aspect, the present invention provides a method for determining the path of a lateral ankle nail insertion device, comprising: Obtain image sequences of the ankle joint; Based on the analysis of image sequences of the ankle joint, the talus, fibula, and outer contour of the skin were identified and determined, and an ankle joint solid model was constructed. Based on the ankle joint solid model, the position of the fibula solid was analyzed to determine the unnamed tubercle of the fibula and establish the pin placement point; Based on the ankle joint solid model and pin placement points, positional analysis of the talus solid was performed to determine the parallel plane of the lateral surface of the talus and to provide an initial rotation reference line. Based on the pin placement point and the preset standard angle, update the initial rotation reference line in the parallel plane of the lateral surface of the talus and give the rotation reference line; Based on the rotation reference line, the first pin placement reference line is given to determine the pin placement path of the lateral ankle.

[0009] Furthermore, based on the analysis of image sequences of the ankle joint, the talus, fibula, and outer contour of the skin are identified and determined, and an ankle joint solid model is constructed, specifically including: Based on the image sequence of the ankle joint, the talus and fibula were located and the talus seed point and fibula seed point were marked; Based on the talus seed point and the fibula seed point, and combined with the bone tissue density, a talus mask and a fibula mask are generated. The solid forms of the talus, fibula, and outer contour of the skin are obtained by using the talus mask, fibula mask, and outer contour of the skin mask. Adjustments were made to the talus, fibula, and outer skin contour to construct a solid model of the ankle joint, including the talus, fibula, and outer skin contour.

[0010] Furthermore, the outer contour mask of the skin is obtained through the following steps: Based on the image sequence of the ankle joint, combined with skin tissue density, the skin outline of the ankle joint is covered to generate an initial skin mask; By obtaining cross-sectional images from the image sequence, seed points on the foot skin can be determined; Based on the seed points of the foot skin, the initial skin mask is adjusted and repaired to form the outer contour mask of the skin.

[0011] Furthermore, combining the ankle joint solid model and pin placement points, a positional analysis of the talus solid was performed to determine the parallel plane of the lateral surface of the talus and to provide an initial rotational reference line, specifically including: Based on the fibula, the inertial axis of the fibula is screened to determine the long axis of the fibula; Determine a parallel line that passes through the pin placement point and is parallel to the long axis of the fibula; this is the parallel line to the long axis of the fibula. Generate the lateral surface of the talus based on the talus entity; Generate a parallel surface that passes through the pin placement point and is parallel to the lateral surface of the talus, thus obtaining the parallel surface of the lateral surface of the talus; By fusing the parallel plane of the lateral surface of the talus with the pin placement point, the initial rotation reference line is determined.

[0012] Furthermore, by integrating the parallel plane of the lateral surface of the talus with the pin placement point, an initial rotation reference line is determined, specifically including: Based on the nail placement point, the parallel line of the long axis of the fibula, and the lateral surface of the talus, a vertical plane of the lateral surface of the talus is generated. By fusing the parallel plane of the lateral surface of the talus with the perpendicular plane of the lateral surface of the talus, the intersection line is obtained, and the initial rotation reference line is determined. Based on the pin placement point and the preset standard angle, update the initial rotation reference line in the parallel plane of the lateral surface of the talus, and provide the rotation reference line, specifically including: Based on the positional relationship between the fibular and talus entities, determine the current position angle α1 between the parallel line Y of the fibular long axis and the initial rotation reference line X; A spatial coordinate system is established using the parallel plane of the lateral surface of the talus as the xy plane and the direction perpendicular to the parallel plane of the lateral surface of the talus as the z direction. Using the pin point a as the origin of the spatial coordinate system, the relationship between the rotation angle δ of the initial rotation reference line X in the xy plane and the preset standard angle α2 is constructed as follows: ; Where α2 is the preset standard angle, α1 is the current position angle between the parallel line Y of the fibular long axis and the initial rotation reference line X, and δ is the rotation angle; Based on the relationship, the rotation angle δ and the rotation direction are determined. The rotation angle δ is specifically expressed as: ; Based on the pin placement point, combined with the rotation angle and rotation direction, adjust the initial rotation reference line on the parallel plane of the lateral surface of the talus to give the rotation reference line.

[0013] Furthermore, based on the pin placement point and the preset standard angle, the initial rotation reference line is updated in the parallel plane of the lateral surface of the talus, and the rotation reference line is given, specifically including: Based on the positional relationship between the fibular and talus entities, determine the current position angle α1 between the parallel line Y of the fibular long axis and the initial rotation reference line X; A spatial coordinate system is established using the parallel plane of the lateral surface of the talus as the xy plane and the direction perpendicular to the parallel plane of the lateral surface of the talus as the z direction. Using the pin placement point a as the origin of the spatial coordinate system, the projection line Y' of the parallel line Y of the long axis of the fibula on the xy plane is given, and the angle β between the parallel line Y of the long axis of the fibula and the xy plane is determined, as well as the angle γ between the initial rotation reference line X and the projection line Y'. Establish the first relation between α1, β, and γ, specifically expressed as: ; Where α1 is the current position angle between the parallel line Y of the long axis of the fibula and the initial rotation reference line X, β is the angle between the parallel line Y of the long axis of the fibula and the xy plane, and γ is the angle between the initial rotation reference line X and the projection line Y'. A second relation is established to establish the relationship between the initial rotation reference line X and the rotation angle δ in the xy plane and the preset standard angles α2, β, and γ, which is specifically expressed as: ; Where α2 is the preset standard angle, β is the angle between the parallel line Y of the fibular long axis and the xy plane, γ is the angle between the initial rotation reference line X and the projection line Y', and δ is the rotation angle. By combining the first and second relations, determine the rotation angle δ and the rotation direction; Based on the pin placement point, combined with the rotation angle and rotation direction, adjust the initial rotation reference line on the parallel plane of the lateral surface of the talus to give the rotation reference line.

[0014] Furthermore, the rotation angle is specifically expressed as: ; Where α1 is the current position angle between the parallel line Y of the long axis of the fibula and the initial rotation reference line X, α2 is the preset standard angle, β is the angle between the parallel line Y of the long axis of the fibula and the xy plane, and δ is the rotation angle.

[0015] Furthermore, after providing the first pin placement reference line, the process also includes determining the second pin placement reference line, specifically including: Based on the fibula, the bony ridge regions within the fibula are marked to form the bony ridge axis, thus obtaining the moving reference line; Based on the moving reference line and the lateral surface of the talus, a moving reference surface is generated; Within the moving reference plane, combining the direction and moving distance of the moving reference line, copy and move the first pin placement reference line to determine the second pin placement reference line.

[0016] Secondly, the present invention also provides a method for preparing a guide plate, comprising: Construct a guide plate base for the lateral ankle; Based on the above method for determining the lateral ankle pin placement path, a first pin placement reference line and / or a second pin placement reference line are given; Based on the first pin placement reference line, the inner diameter and outer diameter of the first pin track are set to form the first pin track entity, and / or, based on the second pin placement reference line, the inner diameter and outer diameter of the second pin track are set to form the second pin track entity; Assemble the guide plate base, the first pin track entity, and / or the second pin track entity to form the first guide plate; The first guide plate is cut to obtain the arthroscopic operating area, forming the second guide plate; Based on the guide plate segmentation surface, the second guide plate is segmented to form an inner guide plate component and an outer guide plate component; The inner guide plate component and the outer guide plate component are assembled through multiple sets of fixing structures to obtain the outer ankle guide plate.

[0017] Furthermore, the lateral ankle guide plate is detachably fixed to the foot. The lateral ankle guide plate includes a pin placement part and a positioning part. The pin placement part covers the lateral ankle, and the positioning part covers the heel. One end of the first pin channel entity and / or the second pin channel entity is fixed to the pin placement part, and the other end extends in a direction away from the positioning part. The inner channel of the first pin channel entity and / or the second pin channel entity passes through the pin placement part. The fixing structure includes a locking latch and a locking groove. The locking groove is located on the outer guide plate component, and the locking latch is fixed on the inner guide plate component. The outer guide plate component and the inner guide plate component are fixed together by multiple sets of fixing structures to form the outer ankle guide plate.

[0018] The present invention provides a method for determining the lateral ankle nail placement path and a method for preparing a guide plate, which has at least the following beneficial effects: (1) By analyzing the image sequence of the ankle joint, a solid model of the ankle joint is constructed. The position of the fibula and talus is analyzed to establish the pin placement point and determine the parallel plane of the lateral surface of the talus. An initial rotation reference line is given. Combined with the preset standard angle, the initial rotation reference line is updated in the parallel plane of the lateral surface of the talus, and the rotation reference line is given to determine the pin placement path of the lateral ankle. By combining inertial axis fitting, plane fitting and orthogonal plane intersection, the problem of pin placement angle relying on experience in traditional methods is solved, and a repeatable and verifiable geometric method is provided for pin placement position determination.

[0019] (2) By determining the initial rotation reference line, the direction of the initial rotation reference line can be obtained as the parallel direction of the lateral surface of the talus. By rotating the parallel surface of the lateral surface of the talus, the angle between the initial rotation reference line and the parallel line of the long axis of the fibula can be adjusted, and the final rotation reference line can be determined, providing a precise directional reference for the design of the nail path.

[0020] (3) By anatomical fitting, geometric constraints and precise translation, the first pin placement reference line and the second pin placement reference line are determined to achieve double anchor pin positioning. By combining the moving reference line and the moving reference surface, the angle is locked to prevent offset, which solves the problem that the spacing between the two pins depends on personal experience in the traditional method, reduces the error and improves the pin placement accuracy.

[0021] (4) The first pin placement reference line and / or the second pin placement reference line obtained by the method of determining the pin placement path of the lateral ankle are used to prepare the lateral ankle guide plate, which provides an accurate visual reference for the lateral ankle guide plate, making it easy to implement accurately, and making the final lateral ankle guide plate less prone to shaking during use. Attached Figure Description

[0022] Figure 1 A flowchart illustrating a method for determining the path of a lateral ankle nail placement according to an embodiment of the present invention; Figure 2 A schematic diagram illustrating the process of constructing an ankle joint solid model according to an embodiment of the present invention; Figure 3 This is a flowchart illustrating the initial rotation reference line provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of a first structure for determining an initial rotation reference line, provided in an embodiment of the present invention. Figure 5 A first exploded view of the structure for determining the initial rotation reference line provided in an embodiment of the present invention; Figure 6 A flowchart illustrating the rotation reference line is provided for an embodiment of the present invention; Figure 7 This is a schematic diagram of the second structure for determining the initial rotation reference line provided in an embodiment of the present invention; Figure 8This is a flowchart illustrating the process of determining the second pin placement reference line provided in an embodiment of the present invention; Figure 9 This is a schematic flowchart of a guide plate preparation method provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the external ankle guide plate provided in an embodiment of the present invention.

[0023] In the figure, 1. Lateral ankle guide plate; 11. Pin placement section; 12. Positioning section; 13. Lateral guide plate component; 14. Medial guide plate component; 15. First pin track entity; 16. Second pin track entity; 17. Fixation structure; 18. Locking device; 19. Arthroscopic operation area. Detailed Implementation

[0024] To better understand the above technical solutions, a detailed description of the solutions will be provided below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0026] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0027] The analysis of CT image sequences and the construction of the ankle joint solid model are carried out in medical image processing and 3D reconstruction software, such as Mimics 21.0 developed by Materialise in Belgium.

[0028] After obtaining the ankle joint solid model, the process of determining the rotation reference line and the lateral ankle pin placement path is carried out in visualization engineering design software. For example, 3-Matic 13.0 developed by Materialise in Belgium can be selected, which, along with Mimics 21.0, belongs to the medical image processing and biomedical engineering software suite.

[0029] like Figure 1 As shown in the figure, this embodiment of the invention provides a method for determining the path of the lateral ankle nail placement, the specific steps of which are as follows: S101: Obtain image sequences of the ankle joint.

[0030] The image sequence can be a CT image sequence, an MRI image sequence, or any other image sequence capable of constructing a three-dimensional model; there is no limitation on the latter. In the embodiments provided by this invention, a CT image sequence of the ankle joint is used for explanation. The ankle joint image sequence is a set of continuous images obtained by performing continuous tomographic scans of the ankle joint using a CT scanning device. After computer reconstruction processing, the scan data of each layer generates a cross-sectional image. The cross-sectional image shows the internal structure of tissues such as bones, joints, muscles, and fat at that layer, with tissues of different densities exhibiting different gray levels.

[0031] S102: Based on the analysis of image sequences of the ankle joint, identify and determine the talus, fibula, and outer contour of the skin to construct an ankle joint solid model.

[0032] Specifically, based on the analysis of image sequences of the ankle joint, the talus, fibula, and outer skin contours are identified and determined to construct a solid model of the ankle joint, referring to... Figure 2 Specifically, it includes: Based on the image sequence of the ankle joint, the talus and fibula were located and the talus seed point and fibula seed point were marked; Based on the talus seed point and the fibula seed point, and combined with the bone tissue density, a talus mask and a fibula mask are generated. The solid forms of the talus, fibula, and outer contour of the skin are obtained by using the talus mask, fibula mask, and outer contour of the skin mask. Adjustments were made to the talus, fibula, and outer skin contour to construct a solid model of the ankle joint, including the talus, fibula, and outer skin contour.

[0033] In one specific implementation, a CT image sequence of the ankle joint is first imported, and the window width and window level of the CT image sequence are adjusted. The talus and fibula images in the ankle joint are clearly displayed from the CT image sequence. The coronal, sagittal, and transverse planes of the CT image sequence are observed simultaneously to locate the image range of the talus and fibula, and the talus seed point and fibula seed point are marked. For example, the center of the talus body is used as the talus seed point, and the apex of the distal fibula at the lateral malleolus is used as the fibula seed point. The starting positions for generating the talus mask and fibula mask are determined by the talus seed point and fibula seed point. Based on the bone tissue density, the initial talus mask and fibula mask are generated. Combined with a pre-set number of iterations, the edges of the initial talus mask and fibula mask are smoothed, and the talus mask and fibula mask are checked in a 3D view to see if they completely cover the talus and fibula. Excess tissue in the initial talus mask and fibula mask is deleted, and missing areas in the initial talus mask and fibula mask are filled in, resulting in the talus mask and fibula mask. Bone tissue density is referred to as the HU value range of bone tissue. The HU value range refers to a specific range of HU values ​​set in CT image processing, used to screen, segment, or identify specific tissues or structures. For example, the HU value range for bone tissue is >150 or >200.

[0034] By segmenting the 3D contours of the talus and fibula from CT image sequences, talus and fibula masks are generated, laying the foundation for the subsequent generation of talus and fibula entities.

[0035] Furthermore, the outer contour mask of the skin is obtained through the following steps: Based on the image sequence of the ankle joint, combined with skin tissue density, the skin outline of the ankle joint is covered to generate an initial skin mask; By obtaining cross-sectional images from the image sequence, seed points on the foot skin can be determined; Based on the seed points of the foot skin, the initial skin mask is adjusted and repaired to form the outer contour mask of the skin.

[0036] In one specific implementation, the outer contour of the ankle skin is selected from a CT image sequence of the ankle joint based on skin tissue density to generate an initial skin mask. This initial skin mask completely covers the skin and subcutaneous fat within the ankle joint. Seed points for the foot skin are selected and determined using cross-sectional images from the CT image sequence; for example, the center of the sole is chosen as the seed point. The initial skin mask is then adjusted based on these seed points, cropping excess areas and filling in minor imperfections (such as gaps in skin folds) and pits on the skin surface to obtain the outer contour skin mask.

[0037] By segmenting the 3D contour of the foot skin, a skin-fitting surface reference was provided, which in turn provided data support for the subsequent preparation of the guide plate.

[0038] After obtaining the talus mask, fibula mask, and skin outer contour mask, select all three masks simultaneously and set parameters to perform solid modeling, generating initial solids for the talus, fibula, and skin outer contour. Converting the 2D masks into 3D solid models provides the geometric basis for subsequent operations.

[0039] Adjust the entity parameters of the initial entities of the talus, fibula, and skin outer contour to make the surfaces of each entity smooth, fix the defects of the initial entities of the talus and fibula, and construct the ankle joint entity model.

[0040] In the embodiments provided by this invention, a solid coordinate system is set for the ankle joint solid model, and the origin of the solid coordinate system is set to the lateral malleolus tip (a clinical anatomical landmark, facilitating subsequent pin placement). In other examples, the origin and direction of the solid coordinate system can be adjusted according to the actual situation, and there is no limitation thereto. By comparing the ankle joint solid model with CT image sequences (such as the trochlear articular surface of the talus and the lateral malleolus tip of the fibula) in a 3D view, the consistency between the solid model and the images is ensured.

[0041] By optimizing the smoothness and anatomical accuracy of each initial entity and eliminating mesh defects including burrs and pits, the constructed ankle joint solid model meets the requirements of anatomical accuracy, geometric integrity, and surface smoothness, providing a high-quality and reliable 3D geometric foundation for subsequent pin placement marking and guide plate design.

[0042] S103: Based on the ankle joint solid model, perform positional analysis on the fibular solid, determine the unnamed tubercle of the fibular bone, and establish the pin placement point.

[0043] In the embodiments provided by the present invention, the unnamed tubercle of the fibula is the highest point of the angle between the two bone surfaces of the anterior inferior border and the inferior border of the fibula. The unnamed tubercle of the fibula is used as the pin placement point. In other embodiments, other obvious nodes can be selected as pin placement points, and there is no limitation on this.

[0044] S104: Combining the ankle joint solid model and pin placement points, perform positional analysis on the talus solid, determine the parallel plane of the lateral surface of the talus, and provide an initial rotation reference line.

[0045] Specifically, based on the ankle joint solid model and pin placement points, the position of the talus solid was analyzed to determine the parallel plane of the lateral surface of the talus, and an initial rotation reference line was given. Figure 3 Specifically, it includes: Based on the fibula, the inertial axis of the fibula is screened to determine the long axis of the fibula; Determine a parallel line that passes through the pin placement point and is parallel to the long axis of the fibula; this is the parallel line to the long axis of the fibula. Generate the lateral surface of the talus based on the talus entity; Generate a parallel surface that passes through the pin placement point and is parallel to the lateral surface of the talus, thus obtaining the parallel surface of the lateral surface of the talus; By fusing the parallel plane of the lateral surface of the talus with the pin placement point, the initial rotation reference line is determined.

[0046] In one specific implementation, the initial rotation reference line is any straight line passing through the pin placement point in the parallel plane of the lateral surface of the talus. To improve the efficiency of determining the rotation reference line and simplify the calculation process for determining the rotation angle, the initial rotation reference line can be further determined by determining the parallel line to the long axis of the fibula and the perpendicular plane to the lateral surface of the talus.

[0047] Furthermore, by integrating the parallel plane of the lateral surface of the talus with the pin placement point, an initial rotation reference line is determined, specifically including: Based on the nail placement point, the parallel line of the long axis of the fibula, and the lateral surface of the talus, a vertical plane of the lateral surface of the talus is generated. By fusing the parallel plane to the lateral surface of the talus with the perpendicular plane to the lateral surface of the talus, the intersection line is obtained, and the initial rotation reference line is determined.

[0048] In one specific implementation, refer to Figure 4 , Figure 5 Side A is the side of the fibula furthest from the talus, called the lateral fibula. Side B is the side of the fibula closest to the talus, called the medial fibula. Similarly, side B is the side of the talus closest to the fibula, called the lateral talus. Side C is the side of the talus furthest from the fibula, called the medial talus. Based on the relative relationship between the fibula and talus, the fibular surface fitted on side A is the lateral fibular surface, the fibular surface fitted on side B is the medial fibular surface, the talar surface fitted on side B is the lateral talar surface E, and the talar surface fitted on side C is the medial talar surface. The fibular entity is selected and fitted to generate three axes of inertia. These three axes represent the long axis, middle axis, and short axis of the fibula, respectively. The longest axis is the long axis D, which typically extends from the proximal metaphysis of the fibula to the tip of the lateral malleolus. The other two axes of inertia are deleted, leaving only the long axis D. The long axis D of the fibula is a straight line connecting the center of the fibular head and the center of the lateral malleolus tip, representing the main longitudinal direction of the fibula in three-dimensional space. In medical imaging, it can be determined by fitting the center points of continuous cross-sections.

[0049] After determining the long axis D of the fibula, the lateral surface region of the talus is selected from the solid talus, and the lateral surface E of the talus is fitted using the irregular surface of the lateral surface region. The fitted lateral surface E of the talus intersects the solid talus to a certain extent. Based on the long axis D of the fibula and the pin placement point, a line Y parallel to the long axis D of the fibula is generated, passing through the pin placement point. Based on the lateral surface E of the talus and the pin placement point, a plane parallel to the lateral surface E of the talus is generated, passing through the pin placement point and parallel to the lateral surface E of the talus. Based on the pin placement point, the line Y parallel to the long axis of the fibula, and the lateral surface E of the talus, a vertical plane F perpendicular to the lateral surface E of the talus is generated. Finally, based on the parallel plane and the vertical plane F of the lateral surface of the talus, the intersection line of the two planes is determined, and the intersection line is set as the initial rotation reference line X.

[0050] By determining the long axis D of the fibula, the main extension direction of the fibula can be obtained, providing an accurate reference axis for calculating the anchor placement angle. The long axis D of the fibula is the main biomechanical axis of the fibula anatomically. The anchor placement angle (e.g., at 45° with the long axis) needs to be calculated along this axis to ensure that the biomechanical structure of the fibula is not damaged after the anchor is implanted.

[0051] By selecting the lateral surface of the talus trochlea where the anterior talofibular ligament attaches, the lateral surface of the talus is generated, providing a reference for the direction of screw placement. The lateral surface of the talus is one of the reference anatomical structures for screw placement. The screw placement line must be parallel to the lateral surface of the talus to ensure that the screw placement path does not deviate from the predetermined direction, passes through the medial fibular recess in advance, and does not disrupt the mechanical integrity of the fibula.

[0052] The Y-line, parallel to the long axis of the fibula, is determined by the pin placement point, providing a reference line for angle measurement. The Y-line is an extension of the long axis D of the fibula at the pin placement point. By measuring the angle between the Y-line and the plane parallel to the lateral surface of the talus, the required rotation angle can be calculated.

[0053] The lateral surface of the talus is determined by the pin placement point, providing a reference plane for the pin placement direction. This lateral surface of the talus acts as a constraint plane for the pin placement line, ensuring that the pin placement path does not deviate from the preset direction and exits the medial fibular recess in advance.

[0054] By determining the initial rotation reference line, we can find that the direction of the initial rotation reference line is parallel to the lateral surface of the talus. The rotation of the initial rotation reference line on the parallel plane of the lateral surface of the talus can adjust the angle between the initial rotation reference line and the long axis of the fibula to meet the requirements of the screw placement angle.

[0055] By using inertial axis fitting, plane fitting, and orthogonal plane intersection, the problem of the pin placement angle relying on experience in traditional methods is solved, providing a repeatable and verifiable geometric method for determining pin placement position and designing personalized guide plates.

[0056] S105: Based on the pin placement point and the preset standard angle, update the initial rotation reference line in the parallel plane of the lateral surface of the talus and give the rotation reference line.

[0057] In one specific implementation, when the initial rotation reference line is any straight line passing through the pin placement point in the parallel plane of the lateral surface of the talus, it is necessary to use the projection line Y' of the parallel line Y of the long axis of the fibula on the xy plane to define the position of the initial rotation reference line X.

[0058] Furthermore, based on the pin placement point and the preset standard angle, the initial rotation reference line is updated in the parallel plane of the lateral surface of the talus, and a rotation reference line is given for reference. Figure 6 Specifically, it includes: Based on the positional relationship between the fibular and talus entities, determine the current position angle α1 between the parallel line Y of the fibular long axis and the initial rotation reference line X; A spatial coordinate system is established using the parallel plane of the lateral surface of the talus as the xy plane and the direction perpendicular to the parallel plane of the lateral surface of the talus as the z direction. Using the pin placement point a as the origin of the spatial coordinate system, the projection line Y' of the parallel line Y of the long axis of the fibula on the xy plane is given, and the angle β between the parallel line Y of the long axis of the fibula and the xy plane is determined, as well as the angle γ between the initial rotation reference line X and the projection line Y'. Establish the first relation between α1, β, and γ, specifically expressed as: ; Where α1 is the current position angle between the parallel line Y of the long axis of the fibula and the initial rotation reference line X, β is the angle between the parallel line Y of the long axis of the fibula and the xy plane, and γ is the angle between the initial rotation reference line X and the projection line Y'. A second relation is established to establish the relationship between the initial rotation reference line X and the rotation angle δ in the xy plane and the preset standard angles α2, β, and γ, which is specifically expressed as: ; Where α2 is the preset standard angle, β is the angle between the parallel line Y of the fibular long axis and the xy plane, γ is the angle between the initial rotation reference line X and the projection line Y', and δ is the rotation angle. By combining the first and second relations, determine the rotation angle δ and the rotation direction; Based on the pin placement point, combined with the rotation angle and rotation direction, adjust the initial rotation reference line on the parallel plane of the lateral surface of the talus to give the rotation reference line.

[0059] The rotation direction is a clockwise or counterclockwise rotation of the initial rotation reference line within a plane parallel to the outer surface of the talus, with the pin placement point as the rotation center.

[0060] Furthermore, the rotation angle is specifically expressed as: ; ; Where α1 is the current position angle between the parallel line Y of the long axis of the fibula and the initial rotation reference line X, α2 is the preset standard angle, β is the angle between the parallel line Y of the long axis of the fibula and the xy plane, and δ is the rotation angle.

[0061] Where cosβ≠0, that is, β≠90°. It can be understood that, based on the positional relationship between the parallel line Y of the fibular long axis and the xy plane, β will not equal 90°. In extreme cases, the positional relationship between the parallel line Y of the fibular long axis and the xy plane can be adjusted. Similarly, the ratio of cosα2 to cosβ is within the range of [-1, 1]. If it exceeds [-1, 1], the preset standard angle is adjusted so that the ratio of cosα2 to cosβ falls within the range of [-1, 1]. Likewise, the ratio of cosα1 to cosβ is within the range of [-1, 1]. If it exceeds [-1, 1], the initial rotation reference line X is adjusted according to the rotation direction so that the ratio of cosα1 to cosβ is within the range of [-1, 1].

[0062] Understandably, the angle between the parallel line Y of the fibular long axis and the initial rotation reference line X (i.e., the current position angle α1) is determined through the following steps: First, determine the direction vector of the parallel line Y of the fibular long axis in the spatial coordinate system, denoted as the first vector. Determine the direction vector of the initial rotation reference line X, denoted as the second vector. Calculate the dot product of the first and second vectors to obtain the vector product. Next, calculate the magnitudes of the first and second vectors, and give the product of the magnitudes of the first and second vectors to obtain the magnitude product. The cosine of the angle is determined by the ratio of the vector product and the magnitude product, thus determining the current position angle α1.

[0063] In one specific implementation, refer to Figure 7 First, based on the positional relationship between the fibular and talus entities, the current position angle α1 between the parallel line Y of the fibular long axis and the initial rotation reference line X is determined. Using the pin placement point a as the origin of the spatial coordinate system, the parallel plane of the lateral surface of the talus as the xy plane, and the direction perpendicular to the parallel plane of the lateral surface of the talus as the z-direction, a spatial coordinate system is established. Based on this spatial coordinate system, the projection line Y' of the parallel line Y of the fibular long axis on the xy plane is given, and the angle β between the parallel line Y of the fibular long axis and the xy plane, as well as the angle γ between the initial rotation reference line X and the projection line Y', are determined.

[0064] Based on the positional relationships of the parallel line Y of the fibular long axis, the initial rotation reference line X, the projection line Y', and the xy plane in the spatial coordinate system, a first relation is established. Based on the positional relationships between the rotation angle δ of the initial rotation reference line X in the xy plane and the preset standard angles α2, β, and γ in the spatial coordinate system, a second relation is established. By combining the first and second relations, the rotation angle δ and the rotation direction can be determined. Based on the pin placement point, combined with the rotation angle and rotation direction, the initial rotation reference line is adjusted on the parallel plane of the lateral surface of the talus to give the rotation reference line. The rotation direction is the clockwise or counterclockwise rotation of the initial rotation reference line within the parallel plane of the lateral surface of the talus, with the pin placement point as the rotation center. That is, with the pin placement point as the rotation center, the initial rotation reference line is rotated clockwise or counterclockwise within the parallel plane of the lateral surface of the talus. When the rotation angle is reached, the rotation stops, and the angle between the rotation reference line and the long axis of the fibula is the preset standard angle.

[0065] It's important to understand that whether the rotation direction is clockwise or counterclockwise depends on the observation position and the value of the rotation angle. In a specific example, the rotation direction is from the initial rotation reference line towards the direction closest to the rotation reference line, that is, rotating the distal end of the initial rotation reference line (determined by the distal direction of the fibula) towards the anterior edge of the fibula (towards the anterior side of the fibula and talus, i.e., the front of the body).

[0066] In a specific example, within the parallel plane of the lateral surface of the talus, the initial rotation reference line is rotated posteriorly along the fibula (i.e., from the lateral malleolus towards the lower leg) with the pin placement point as the center of rotation, ensuring that the obtained rotation reference line points towards the proximal end of the fibula. In this example, the preset standard angle is 45°, meaning the angle between the final obtained rotation reference line and the long axis of the fibula is 45°. In other examples, the preset standard angle can be adjusted according to the actual situation; there are no limitations on this.

[0067] By adjusting the initial rotation reference line in the parallel plane of the lateral surface of the talus, and combining it with the rotation angle, the final rotation reference line is obtained, providing a precise directional reference for pin track design.

[0068] In another specific implementation, when the initial rotation reference line is the intersection of the parallel plane of the lateral surface of the talus and the perpendicular plane of the lateral surface of the talus, the rotation angle can be directly determined by the current position angle between the parallel line Y of the long axis of the fibula and the initial rotation reference line X. This simplifies the process of determining the rotation reference line from the initial rotation reference line and improves the efficiency of determining the pin placement path.

[0069] like Figure 4 , Figure 5 As shown, based on the pin placement point and the preset standard angle, the initial rotation reference line is updated in the parallel plane of the lateral surface of the talus, and the rotation reference line is given, specifically including: Based on the positional relationship between the fibular and talus entities, determine the current position angle α1 between the parallel line Y of the fibular long axis and the initial rotation reference line X; A spatial coordinate system is established using the parallel plane of the lateral surface of the talus as the xy plane and the direction perpendicular to the parallel plane of the lateral surface of the talus as the z direction. Using the pin point a as the origin of the spatial coordinate system, the relationship between the rotation angle δ of the initial rotation reference line X in the xy plane and the preset standard angle α2 is constructed as follows: ; Where α2 is the preset standard angle, α1 is the current position angle between the parallel line Y of the fibular long axis and the initial rotation reference line X, and δ is the rotation angle; Based on the relationship, the rotation angle δ and the rotation direction are determined. The rotation angle δ is specifically expressed as: ; Based on the pin placement point, combined with the rotation angle and rotation direction, adjust the initial rotation reference line on the parallel plane of the lateral surface of the talus to give the rotation reference line.

[0070] First, determine the angle between the initial rotation reference line and the line parallel to the long axis of the fibula, i.e., the line parallel to the long axis of the fibula and the plane parallel to the lateral surface of the talus, and determine the current position angle. Calculate the ratio of the cosine of the preset standard angle to the cosine of the current position angle to obtain the radian difference. Convert the radian difference to an angle to obtain the rotation angle. Using the pin placement point as the rotation center, rotate the initial rotation reference line clockwise or counterclockwise within the plane parallel to the lateral surface of the talus. Stop rotating when the rotation angle is reached. At this point, the angle between the rotation reference line and the long axis of the fibula is the preset standard angle.

[0071] S106: Based on the rotation reference line, give the first pin placement reference line and determine the pin placement path of the lateral ankle.

[0072] The rotation reference line is used as the first pin placement reference line, which is the pin placement path for the lateral ankle.

[0073] Understandably, the number of pins required may vary depending on the circumstances. In addition to providing a first pin placement reference line, the method for determining the pin placement path on the lateral ankle also includes determining a second pin placement reference line, referring to... Figure 8 Specifically, it includes: Based on the fibula, the bony ridge regions within the fibula are marked to form the bony ridge axis, thus obtaining the moving reference line; Based on the moving reference line and the lateral surface of the talus, a moving reference surface is generated; Within the moving reference plane, combining the direction and moving distance of the moving reference line, copy and move the first pin placement reference line to determine the second pin placement reference line.

[0074] In one specific implementation, the bony ridge region along the anteroinferior margin of the distal fibula is marked within the fibular body. The bony ridge axis is fitted and used as a reference line for translation, ensuring the translation path follows the anatomical orientation of the bony ridge. Based on the translation reference line and the lateral surface of the talus, a translation reference plane containing the translation reference line and perpendicular to the lateral surface of the talus is generated. The bony ridge axis serves as the axis of inertia for fitting the contour of the bony ridge region.

[0075] The moving reference plane is both an anatomical constraint plane, ensuring that the translation direction is parallel to the physiological plane of the ligament by perpendicularly to the lateral surface of the talus, thus avoiding ligament twisting after anchor implantation; and a path constraint plane, restricting translation to only within the bony ridge region by including the moving reference line, ensuring that the second pin placement point is offset longitudinally along the bony ridge, and preventing offset to the weak area of ​​the fibular lateral wall.

[0076] The first pin placement reference line is used as the translation reference. Within the translation reference plane, the first pin placement reference line is translated a preset distance (e.g., 8mm) towards the proximal fibula along the direction of the translation reference line, generating the second pin placement reference line. The proximal fibula refers to the upper part of the fibula near the center of the body (near the trunk), which is the area where the fibula connects to the knee joint region. The translation distance is related to the width of the anterior talofibular ligament, and is usually determined based on the average width of the anterior talofibular ligament (6-8mm), but the translation distance is adjusted according to different actual situations.

[0077] After determining the first and second pin placement reference lines, the distance between them is measured, and the starting point of the second pin placement reference line is checked to ensure it is on the bony ridge, avoiding deviation to the fibular lateral wall. Pin track safety is also verified by measuring the length of the fibular intraosseous pin track, i.e., the distance from the bone surface to the contralateral cortex along the directions of the first and second pin placement reference lines, ensuring the length of the fibular intraosseous pin track is ≥18mm.

[0078] By employing anatomical fitting, geometric constraints, and precise translation, a first and second pin placement reference line are determined, achieving dual-anchor pin positioning. The moving reference plane, generated based on the bony ridge anatomy, provides an anatomical constraint plane for the translation of the second pin placement point, ensuring the translation path conforms to individualized bony structures. The moving reference line serves as the path benchmark for translation; the translation operation moves along the bony ridge axis, locking the angle to prevent deviation. This approach addresses the issue of traditional methods where the pin spacing relies on personal experience, reducing errors and improving pin placement accuracy.

[0079] Reference Figure 9 This invention provides a method for preparing a guide plate, the specific steps of which are as follows: Construct a guide plate base for the lateral ankle; Based on the above method for determining the lateral ankle pin placement path, a first pin placement reference line and / or a second pin placement reference line are given; Based on the first pin placement reference line, the inner diameter and outer diameter of the first pin track are set to form the first pin track entity 15, and / or, based on the second pin placement reference line, the inner diameter and outer diameter of the second pin track are set to form the second pin track entity 16. Assemble the guide plate base, the first pin track entity 15 and / or the second pin track entity 16 to form the first guide plate; The first guide plate is cut to obtain the arthroscopic operating area 19, forming the second guide plate; Based on the guide plate segmentation surface, the second guide plate is segmented to form an inner guide plate component 14 and an outer guide plate component 13. The inner guide plate component 14 and the outer guide plate component 13 are assembled by multiple sets of fixing structures 17 to obtain the outer ankle guide plate 1.

[0080] Furthermore, referring to Figure 10 The lateral ankle guide plate 1 is detachably fixed to the foot. The lateral ankle guide plate 1 includes a pin placement part 11 and a positioning part 12. The pin placement part 11 covers the lateral ankle, and the positioning part 12 covers the heel. One end of the first pin channel body 15 and / or the second pin channel body 16 is fixed to the pin placement part 11, and the other end extends in a direction away from the positioning part 12. The inner channel of the first pin channel body 15 and / or the second pin channel body 16 passes through the pin placement part 11. The fixing structure 17 includes a locking latch 18 and a locking groove. The locking groove is located on the outer guide plate member 13, and the locking latch 18 is fixed on the inner guide plate member 14. The outer guide plate member 13 and the inner guide plate member 14 are fixed together by multiple sets of fixing structures 17 to form the outer ankle guide plate 1.

[0081] Furthermore, the lateral ankle guide plate 1 includes a detachable and fixed lateral guide plate component 13 and an inner guide plate component 14. A portion of the pin placement part 11 is located on the lateral guide plate component 13, and another portion is located on the inner guide plate component 14. A positioning part 12 is located on the lateral guide plate component 13. When the lateral guide plate component 13 and the inner guide plate component 14 are fixed, the lateral guide plate component 13 and the inner guide plate component 14 enclose each other to form a cylindrical structure.

[0082] In one specific implementation, an initial guide plate base is generated based on the guide plate thickness. According to the first pin placement reference line and / or the second pin placement reference line, the inner and outer diameters of the first pin channel and / or the second pin channel are set to preset values. A first pin channel entity 15 and / or a second pin channel entity 16 are generated on the guide plate base to form the first guide plate. A cutting marking area is set on the first guide plate and cutting is performed to obtain the arthroscopic operating area 19, forming the second guide plate. A guide plate dividing surface is set on the second guide plate and the second guide plate is divided to form an inner guide plate component 14 and an outer guide plate component 13. The inner guide plate component 14 and the outer guide plate component 13 are assembled using multiple sets of fixing structures 17 to obtain the lateral ankle guide plate 1. The fixing structures 17 are used to fix and assemble the outer guide plate component 13 and the inner guide plate component 14. The size of the fixing structures 17 can be adjusted according to actual conditions and is not limited thereto.

[0083] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the described module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0084] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. A method for determining the path for nail placement on the lateral ankle, characterized in that, Specifically, the steps include the following: Obtain image sequences of the ankle joint; Based on the analysis of image sequences of the ankle joint, the talus, fibula, and outer contour of the skin were identified and determined, and an ankle joint solid model was constructed. Based on the ankle joint solid model, the position of the fibula solid was analyzed to determine the unnamed tubercle of the fibula and establish the pin placement point; Based on the ankle joint solid model and pin placement points, positional analysis of the talus solid was performed to determine the parallel plane of the lateral surface of the talus and to provide an initial rotation reference line. Based on the pin placement point and the preset standard angle, update the initial rotation reference line in the parallel plane of the lateral surface of the talus and give the rotation reference line; Based on the rotation reference line, the first pin placement reference line is given to determine the pin placement path of the lateral ankle.

2. The method for determining the lateral ankle nail placement path as described in claim 1, characterized in that, Based on the analysis of image sequences of the ankle joint, the talus, fibula, and outer contour of the skin were identified and determined, and a solid model of the ankle joint was constructed, specifically including: Based on the image sequence of the ankle joint, the talus and fibula were located and the talus seed point and fibula seed point were marked; Based on the talus seed point and the fibula seed point, and combined with the bone tissue density, a talus mask and a fibula mask are generated. The solid forms of the talus, fibula, and outer contour of the skin are obtained by using the talus mask, fibula mask, and outer contour of the skin mask. Adjustments were made to the talus, fibula, and outer skin contour to construct a solid model of the ankle joint, including the talus, fibula, and outer skin contour.

3. The method for determining the lateral ankle nail placement path as described in claim 2, characterized in that, The outer contour mask of the skin is obtained through the following steps: Based on the image sequence of the ankle joint, combined with skin tissue density, the skin outline of the ankle joint is covered to generate an initial skin mask; By obtaining cross-sectional images from the image sequence, seed points on the foot skin can be determined; Based on the seed points of the foot skin, the initial skin mask is adjusted and repaired to form the outer contour mask of the skin.

4. The method for determining the lateral ankle nail placement path as described in claim 1, characterized in that, Based on the ankle joint solid model and pin placement points, positional analysis of the talus solid was performed to determine the parallel plane of the lateral surface of the talus and to provide an initial rotational reference line, specifically including: Based on the fibula, the inertial axis of the fibula is screened to determine the long axis of the fibula; Determine a parallel line that passes through the pin placement point and is parallel to the long axis of the fibula; this is the parallel line to the long axis of the fibula. Generate the lateral surface of the talus based on the talus entity; Generate a parallel surface that passes through the pin placement point and is parallel to the lateral surface of the talus, thus obtaining the parallel surface of the lateral surface of the talus; By fusing the parallel plane of the lateral surface of the talus with the pin placement point, the initial rotation reference line is determined.

5. The method for determining the lateral ankle nail placement path as described in claim 4, characterized in that, By fusing the parallel plane of the lateral surface of the talus with the screw placement point, the initial rotation reference line is determined, specifically including: Based on the nail placement point, the parallel line of the long axis of the fibula, and the lateral surface of the talus, a vertical plane of the lateral surface of the talus is generated. By fusing the parallel plane of the lateral surface of the talus with the perpendicular plane of the lateral surface of the talus, the intersection line is obtained, and the initial rotation reference line is determined. Based on the pin placement point and the preset standard angle, update the initial rotation reference line in the parallel plane of the lateral surface of the talus, and provide the rotation reference line, specifically including: Based on the positional relationship between the fibular and talus entities, determine the current position angle α1 between the parallel line Y of the fibular long axis and the initial rotation reference line X; A spatial coordinate system is established using the parallel plane of the lateral surface of the talus as the xy plane and the direction perpendicular to the parallel plane of the lateral surface of the talus as the z direction. Using the pin point a as the origin of the spatial coordinate system, the relationship between the rotation angle δ of the initial rotation reference line X in the xy plane and the preset standard angle α2 is constructed as follows: ； Where α2 is the preset standard angle, α1 is the current position angle between the parallel line Y of the fibular long axis and the initial rotation reference line X, and δ is the rotation angle; Based on the relationship, the rotation angle δ and the rotation direction are determined. The rotation angle δ is specifically expressed as: ； Based on the pin placement point, combined with the rotation angle and rotation direction, adjust the initial rotation reference line on the parallel plane of the lateral surface of the talus to give the rotation reference line.

6. The method for determining the lateral ankle nail placement path as described in claim 4, characterized in that, Based on the pin placement point and the preset standard angle, update the initial rotation reference line in the parallel plane of the lateral surface of the talus, and provide the rotation reference line, specifically including: Based on the positional relationship between the fibular and talus entities, determine the current position angle α1 between the parallel line Y of the fibular long axis and the initial rotation reference line X; A spatial coordinate system is established using the parallel plane of the lateral surface of the talus as the xy plane and the direction perpendicular to the parallel plane of the lateral surface of the talus as the z direction. Using the pin placement point a as the origin of the spatial coordinate system, the projection line Y' of the parallel line Y of the long axis of the fibula on the xy plane is given, and the angle β between the parallel line Y of the long axis of the fibula and the xy plane is determined, as well as the angle γ between the initial rotation reference line X and the projection line Y'. Establish the first relation between α1, β, and γ, specifically expressed as: ； Where α1 is the current position angle between the parallel line Y of the long axis of the fibula and the initial rotation reference line X, β is the angle between the parallel line Y of the long axis of the fibula and the xy plane, and γ is the angle between the initial rotation reference line X and the projection line Y'. A second relation is established to establish the relationship between the initial rotation reference line X and the rotation angle δ in the xy plane and the preset standard angles α2, β, and γ, which is specifically expressed as: ； Where α2 is the preset standard angle, β is the angle between the parallel line Y of the fibular long axis and the xy plane, γ is the angle between the initial rotation reference line X and the projection line Y', and δ is the rotation angle. By combining the first and second relations, determine the rotation angle δ and the rotation direction; Based on the pin placement point, combined with the rotation angle and rotation direction, adjust the initial rotation reference line on the parallel plane of the lateral surface of the talus to give the rotation reference line.

7. The method for determining the lateral ankle nail placement path as described in claim 6, characterized in that, The rotation angle is specifically expressed as: ； Where α1 is the current position angle between the parallel line Y of the long axis of the fibula and the initial rotation reference line X, α2 is the preset standard angle, β is the angle between the parallel line Y of the long axis of the fibula and the xy plane, and δ is the rotation angle.

8. The method for determining the lateral ankle nail placement path as described in claim 1, characterized in that, After providing the first pin placement reference line, the process also includes determining the second pin placement reference line, specifically including: Based on the fibula, the bony ridge regions within the fibula are marked to form the bony ridge axis, thus obtaining the moving reference line; Based on the moving reference line and the lateral surface of the talus, a moving reference surface is generated; Within the moving reference plane, combining the direction and moving distance of the moving reference line, copy and move the first pin placement reference line to determine the second pin placement reference line.

9. A method for preparing a lateral ankle guide plate, characterized in that, Specifically, the steps include the following: Construct a guide plate base for the lateral ankle; The method for determining the lateral ankle pin placement path as described in any one of claims 1-8 provides a first pin placement reference line and / or a second pin placement reference line. Based on the first pin placement reference line, the inner diameter and outer diameter of the first pin track are set to form the first pin track entity, and / or, based on the second pin placement reference line, the inner diameter and outer diameter of the second pin track are set to form the second pin track entity; Assemble the guide plate base, the first pin track entity, and / or the second pin track entity to form the first guide plate; The first guide plate is cut to obtain the arthroscopic operating area, forming the second guide plate; Based on the guide plate segmentation surface, the second guide plate is segmented to form an inner guide plate component and an outer guide plate component; The inner guide plate component and the outer guide plate component are assembled through multiple sets of fixing structures to obtain the outer ankle guide plate.

10. The method for preparing the lateral ankle guide plate as described in claim 9, characterized in that, The lateral ankle guide plate is detachably fixed to the foot. The lateral ankle guide plate includes a pin placement part and a positioning part. The pin placement part covers the lateral ankle, and the positioning part covers the heel. One end of the first pin channel body and / or the second pin channel body is fixed to the pin placement part, and the other end extends in a direction away from the positioning part. The inner channel of the first pin channel body and / or the second pin channel body passes through the pin placement part. The fixing structure includes a locking latch and a locking groove. The locking groove is located on the outer guide plate component, and the locking latch is fixed on the inner guide plate component. The outer guide plate component and the inner guide plate component are fixed together by multiple sets of fixing structures to form the outer ankle guide plate.

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