Screw angle measurement guide positioning method for proximal femoral compression plate

Abstract

The application provides a screw angle measurement and guiding positioning method of a proximal femoral compression plate, which is applied to the technical field of orthopedic surgery assistance, and is characterized in that: a three-dimensional bone shape model of the proximal femur of a patient is constructed before surgery, different X-ray projection directions are simulated, the projection of a virtual guide needle on a two-dimensional image is generated, the included angle parameter between the femoral neck axis and the guide needle projection is measured, the screw incidence angle parameter is corrected, the guide device shell, the guide hole and the sensor layout are further designed based on the angle parameter, and the cooperation simulation is carried out on the three-dimensional bone shape model to evaluate the fitting degree of the guide device on the bone surface and the positioning accuracy of the guide hole, so as to provide accurate reference for preoperative screw placement path planning and intraoperative guide device use, realize the quantifiable design and guiding control of the screw incidence angle, and reduce the deviation of screw placement.

Description

Technical Field

[0001] This application relates to the field of orthopedic surgical assistance technology, and in particular to a method for measuring and guiding the positioning of screw angles in proximal femoral compression plates. Background Technology

[0002] With the development of orthopedic surgical techniques, internal fixation surgery for proximal femoral fractures has gradually become a common clinical treatment option. Among them, proximal femoral compression plates are widely used in the fixation and reduction of proximal femoral fractures to maintain the stability of the fracture ends and promote bone healing.

[0003] In current clinical practice, screw implantation of proximal femoral compression plates usually relies on intraoperative two-dimensional X-ray fluoroscopy for guide pin positioning and angle measurement.

[0004] However, due to the complex structure of the proximal femur, intraoperative two-dimensional images are only planar projections, which are dependent on the projection direction and cannot accurately reflect the spatial relationship between the femoral neck axis and the femoral shaft central axis. Traditional guide designs usually have fixed guide holes and cannot be adjusted according to the individual bone morphology of the patient, making it difficult to correct guide pin deviation in a timely manner. Therefore, the existing technology lacks a guiding and positioning method that can measure the screw incident angle based on the patient's three-dimensional bone morphology and provide an adjustable guide hole and deviation monitoring during the operation, resulting in large deviations in screw implantation angle. Summary of the Invention

[0005] This application provides a method for measuring and guiding the screw angle of a proximal femoral compression plate. The core of this method is as follows: based on a three-dimensional bone morphology model of the patient's proximal femur, the spatial relationship between the femoral neck axis and the femoral shaft central axis is measured. Different X-ray projection directions are simulated to select the optimal projection direction. Two-dimensional images are acquired and the guide pin projection angle is corrected to determine the screw incident angle parameters. Furthermore, a guide model is designed based on the three-dimensional bone morphology model and the screw incident angle parameters. This guide includes an adjustable guide hole and a sensor to realize real-time adjustment and deviation monitoring of the guide pin direction during the operation, thereby reducing the deviation of screw implantation.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] This application provides a method for measuring and guiding the screw angle of a proximal femoral compression plate, the method including:

[0008] Before the operation, a three-dimensional bone morphology model of the proximal femur of the patient was constructed. In the three-dimensional bone morphology model, the spatial angle between the femoral neck axis and the central axis of the femoral shaft was measured. Based on the spatial angle, different projection directions of X-rays were simulated, and the projection direction with the angle between the femoral neck axis and the femoral neck axis in the preset range was selected as the first projection direction.

[0009] Under the first projection direction, acquire two-dimensional image data of the proximal femur in anteroposterior and lateral views. Measure the angle parameters between the femoral neck axis and the guide pin projection on the anteroposterior and lateral views of the two-dimensional image data. Based on the three-dimensional bone morphology model, correct the angle parameters to screw incident angle parameters.

[0010] Based on the three-dimensional bone morphology model and screw incident angle parameters, the corresponding guide design parameters are determined. According to the guide design parameters, the corresponding guide model is designed. The guide model may include at least one guide hole and a sensor. The sensor is used to detect guide needle deviation during the operation, and the guide hole is used to adjust the guide needle direction during the operation.

[0011] In some possible implementations, the corresponding guide design parameters are determined based on a three-dimensional bone morphology model and screw incident angle parameters, which may include:

[0012] Based on the three-dimensional bone morphology model, the first design parameters are determined. The first design parameters may include the guide shell and the fixing base.

[0013] The screw incident angle parameter is mapped onto a three-dimensional bone morphology model of the proximal femur of the patient to determine the second design parameter, which may include the installation position of the guide hole on the guide.

[0014] Based on the first design parameters and the second design parameters, the third design parameters are determined. The third design parameters may include the sensor's installation location.

[0015] The first design parameter, the second design parameter, and the third design parameter are used as the corresponding guide design parameters.

[0016] In some possible implementations, determining the first design parameters based on a three-dimensional bone morphology model may include:

[0017] Based on a three-dimensional bone morphology model, the surface curvature distribution and local geometric features of the greater trochanter, femoral neck, and femoral shaft are extracted.

[0018] Based on the surface curvature distribution and local geometric features, the fitting contour design parameters of the guide housing are calculated;

[0019] Based on the spatial orientation of the femoral shaft central axis, calculate the installation angle design parameters of the fixation base;

[0020] The first design parameter is obtained by combining the contour design parameter with the installation angle design parameter.

[0021] In some possible implementations, mapping the screw incident angle parameter to a three-dimensional bone morphology model of the patient's proximal femur to determine the second design parameter may include:

[0022] Based on the screw incident angle parameter, a screw incident vector is generated, and the screw incident vector is mapped to the three-dimensional bone morphology model to determine the spatial position of the screw incident point.

[0023] Based on the screw's incident vector and the spatial position of the screw's incident point, the screw's incident path is obtained.

[0024] Based on the incident path and the fitting contour design parameters of the guide housing, the installation position parameters and orientation tilt angle parameters of the guide hole on the guide housing are calculated.

[0025] The installation location parameters and orientation tilt angle parameters are used as the second design parameters.

[0026] In some possible implementations, determining the third design parameter based on the first and second design parameters may include:

[0027] Based on the conformal design parameters of the guide housing and the installation position and orientation angle parameters of the guide hole, the sensor setting position is calculated and used as the third design parameter.

[0028] In some possible implementations, based on spatial angles, different X-ray projection directions are simulated, and a projection direction with an angle between the X-ray and the femoral neck axis within a preset range is selected as the first projection direction. This can include:

[0029] Based on the spatial angle, a set of candidate projection directions is generated. For each candidate projection direction, the imaging process of X-ray is simulated, and the angle between the femoral neck axis and each candidate projection direction is calculated.

[0030] The candidate projection direction with an angle between itself and the femoral neck axis within a preset range is selected as the first projection direction.

[0031] In some possible implementations, under the first projection direction, acquiring two-dimensional image data of the proximal femur in anteroposterior and lateral views, and measuring the angle parameters between the femoral neck axis and the guide pin projection on the two-dimensional image data in the anteroposterior and lateral views, may include:

[0032] Two-dimensional imaging data of the proximal femur in anteroposterior and lateral views were acquired under the first projection direction;

[0033] On the anteroposterior two-dimensional image data, the angle between the femoral neck axis projection and the guide pin projection is measured to obtain the anteroposterior angle parameter;

[0034] On the lateral two-dimensional imaging data, the angle between the femoral neck axis projection and the guide pin projection is measured to obtain the lateral angle parameter.

[0035] In some possible implementations, correcting the included angle parameter to the screw incident angle parameter based on a three-dimensional bone morphology model may include:

[0036] The anteroposterior angle parameters and lateral angle parameters are mapped onto the three-dimensional bone morphology model. Based on the spatial relationship between the femoral neck axis and the femoral shaft central axis of the three-dimensional bone morphology model, the anteroposterior angle parameters and lateral angle parameters are spatially corrected to obtain the incident angle of the screw in three-dimensional space.

[0037] The incident angle is used as the parameter for the screw incident angle.

[0038] Among some possible implementation methods, the following may also be included:

[0039] Under the first projection direction, acquire two-dimensional image data of the proximal femur in an oblique position, and measure the angle parameter between the femoral neck axis and the guide pin projection in the oblique position on the two-dimensional image data.

[0040] Among some possible implementation methods, the following may also be included:

[0041] Before the operation, the three-dimensional bone morphology model and the guide model were simulated together to evaluate the fit of the guide model on the patient's bone surface and the positioning accuracy of the guide hole. The guide design parameters were adjusted according to the fit and the positioning accuracy of the guide hole.

[0042] As can be seen from the above technical solution, this application has the following beneficial effects:

[0043] 1. This application constructs a three-dimensional bone morphology model of the proximal femur of the patient before surgery, and generates a two-dimensional image projection of the screw channel by simulating different X-ray projection directions based on the model. This allows for a direct assessment of the screw path and the relationship with the bony structure before surgery, thereby improving the accuracy of preoperative planning.

[0044] 2. This application generates a virtual guide pin projection on a two-dimensional image and performs angular parameter correction by combining the spatial relationship between the femoral neck axis and the femoral shaft central axis, calculates the incident angle of the screw in three-dimensional space, realizes the quantitative analysis of the screw path before operation, and reduces the deviation of screw placement.

[0045] 3. This application maps the screw incident angle parameters obtained from preoperative measurements to a three-dimensional bone morphology model, designs the guide shell, guide hole and sensor layout, and conducts preoperative simulation to evaluate the guide's fit on the bone surface and the positioning accuracy of the guide hole, thereby improving the guide design accuracy and intraoperative operation safety, and reducing guide pin deviation and operation risks. Attached Figure Description

[0046] The present application will be further described below with reference to the accompanying drawings.

[0047] Figure 1 A flowchart of the screw angle measurement and guiding positioning method for the first proximal femoral compression plate provided in this application;

[0048] Figure 2 A flowchart of the second method for measuring and guiding the screw angle of the proximal femoral compression plate provided in this application;

[0049] Figure 3 A flowchart illustrating the screw angle measurement and guidance positioning method for the third type of proximal femoral compression plate provided in this application. Detailed Implementation

[0050] The terms "first," "second," and "third," etc., used in this application specification, claims, and drawings are used to distinguish different objects, not to limit a specific order.

[0051] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0052] To ensure clarity and conciseness in the description of the following embodiments, a brief introduction to the related technologies is given first:

[0053] The proximal femur refers to the region of the femur from the hip joint to the proximal femoral shaft, including the femoral head, femoral neck, greater trochanter, and lesser trochanter. The femoral head and acetabulum form the hip joint, bearing the body weight and participating in weight-bearing transmission. The femoral neck connects the femoral head and femoral shaft at a certain angle and is a common site for proximal femoral fractures. The greater trochanter and lesser trochanter are muscle attachment points, especially the greater trochanter, which is an important attachment point for the gluteal muscles. Due to the complex structure of the proximal femur and the large individual differences in its three-dimensional morphology, the direction of the guide pin, the angle of the screw, and the fit of the guide device are extremely important in fracture fixation and screw implantation surgery, directly affecting the surgical precision and postoperative fracture healing effect.

[0054] Proximal femoral compression plates are widely used in the fixation of proximal femoral fractures, mainly for internal fixation of femoral neck fractures, intertrochanteric fractures, and subtrochanteric fractures. The plate is fixed to the proximal femur and metaphysis with screws, providing stable mechanical support, preventing fracture displacement, and promoting bone healing.

[0055] Research has found that in current surgical procedures, screw implantation relies on two-dimensional imaging (such as C-arm X-ray machines) for guidance. Due to the complex morphology of the proximal femur, including the multidirectional curvature and local geometric features of the greater trochanter, femoral neck, and femoral shaft, two-dimensional imaging only provides planar projection information and is dependent on the projection direction. At different projection angles, the spatial relationship between the femoral neck axis and the femoral shaft central axis will produce different projection results on the image, making it difficult for the surgeon to accurately determine the screw's incident direction and increasing the risk of guide pin deviation.

[0056] In addition, existing guides typically use a fixed hole design, which cannot be adjusted according to the individual bone morphology of the patient. If the guide pin deviates from the predetermined path during the operation, the current technology lacks real-time monitoring and correction methods. Doctors can only rely on repeated fluoroscopy or experience to make adjustments, which not only increases the operation time and radiation exposure, but may also cause the screw position to deviate significantly from the expected planned position, thereby affecting the stability of fracture fixation and healing effect.

[0057] Example 1

[0058] To address the aforementioned issues, this application provides a method for measuring and guiding the screw angle of a proximal femoral compression plate. Please refer to [link to relevant documentation]. Figure 1 .

[0059] In some possible implementation methods, S101, before surgery, a three-dimensional bone morphology model of the proximal femur of the patient is constructed. For example, medical imaging data of the proximal femur of the patient is acquired first, preferably using high-resolution computed tomography data to obtain clear layered images of the bony structure. To ensure the integrity of subsequent modeling, the image acquisition range covers the area from the femoral head to the proximal femoral shaft, thereby including the continuous structure of the femoral head, femoral neck, greater trochanter of the femur, and part of the femoral shaft. After the image data is acquired, it is format-standardized and metal artifacts are corrected to remove image noise generated by implants or scanning equipment and to ensure grayscale consistency between different scanning layers.

[0060] The corrected image data is imported into a medical 3D reconstruction system. A 3D bone morphology model of the proximal femur is generated using a voxel-based reconstruction algorithm. During the 3D reconstruction process, the image grayscale is thresholded to distinguish between cortical and cancellous bone regions. Edge detection and morphological filtering methods are used to eliminate bone surface noise, thereby obtaining a clear bony contour. The reconstructed 3D model can accurately reflect the individualized anatomical structure of the proximal femur of the patient, including the spherical area of ​​the femoral head, the stenotic area of ​​the femoral neck, the greater trochanteric process of the femur, and part of the straight segment of the femoral shaft.

[0061] In the generated three-dimensional bone morphology model, the femoral neck axis and the femoral shaft central axis are fitted based on surface geometric features. For example, by extracting the cross-sectional contour point set of the femoral neck region, the least squares method is used to fit a straight line passing through the center point of each cross-section as the femoral neck axis. At the same time, the midline contour point set of the femoral shaft region is extracted, and the fitted straight line is used as the femoral shaft central axis. The spatial angle between the two axes is calculated to characterize the anatomical direction difference of the proximal femur. This spatial angle parameter varies significantly among individuals and is a key basic parameter for screw incident angle design.

[0062] Furthermore, a spatial reference coordinate system is established by means of the femoral head center, the femoral neck axis and the femoral shaft center axis, so that the anatomical structure of the proximal femur is unified into a standardized coordinate space. The spatial coordinate system serves as the geometric benchmark for preoperative planning and intraoperative positioning, and is used to describe the relative positional relationship between various bony structures.

[0063] While the model is being built, the curvature distribution and local geometric features of the proximal femur outer surface are extracted to analyze the area where the guide fits with the bone surface. By calculating the principal curvature and normal vector direction of the surface, the stable area where the guide can be installed is determined, and the surface fitting contour design data is output. The geometric feature data of this fitting area will be directly used as the initial design basis for the fitting contour of the guide shell, thereby achieving the matching between the guide and the patient's bone surface.

[0064] Through the above steps, a three-dimensional bone morphology model of the proximal femur that closely matches the individual anatomical characteristics of the patient was established. This model can not only provide basic data for the measurement and spatial correction of preoperative screw angles, but also provide geometric references for guide fitting design and installation angle calculation.

[0065] S102, simulates different X-ray projection directions to determine the first projection direction. Please refer to [link / reference]. Figure 2 Based on a three-dimensional bone morphology model, an X-ray projection spatial parameter system is established. By using the geometric relationship between the projection direction and the femoral neck axis and the femoral shaft central axis, the optimal projection direction that meets the requirements of intraoperative operation is generated. This enables quantifiable image projection simulation before surgery, avoiding the accumulation of errors caused by the current reliance on manual adjustment of the X-ray machine angle during surgery.

[0066] A three-dimensional coordinate system is established, with the geometric center of the proximal femur model set as the origin. The extension direction of the femoral shaft central axis is used as the Z-axis reference direction. The direction of the femoral neck axis is defined as the first characteristic vector, and the direction of the femoral shaft axis is defined as the second characteristic vector. By calculating the spatial angle between the first and second characteristic vectors, the spatial characteristics of the individual femoral neck-shaft angle and anteversion angle are reflected. This angle parameter is an important basis for determining the projection direction. Multiple candidate projection directions are generated in the three-dimensional coordinate system, each direction corresponding to a virtual X-ray path. The angle between each candidate direction and the femoral neck axis is calculated. Based on the pre-set preset range, directions that are close to perpendicular to the femoral neck axis (e.g., angles within 8°) are selected. An effective projection direction set is defined as the projection direction between 5° and 95°. By simulating the two-dimensional image projection process under each effective direction, the visual clarity and geometric distortion of the screw channel on the image plane are evaluated. If the screw path shows projection overlap or deformation exceeds the limit under a certain direction, the direction is eliminated and the simulation is re-performed at an adjacent angle. Based on the principle of minimizing the included angle deviation and achieving the best image clarity, the optimal projection direction is determined from the effective direction set. This optimal projection direction is used as the first projection direction mentioned above. This ensures that the screw channel is linearly projected in the two-dimensional image and accurately reflects the spatial relationship between the femoral neck and femoral shaft, thus providing a basis for the orientation setting of the preoperative X-ray equipment.

[0067] S103, under the first projection direction, acquire two-dimensional image data and measure the included angle parameters. For an example, please refer to [link to example]. Figure 3 Two-dimensional imaging data of the proximal femur of the patient were acquired under the first projection direction, including anteroposterior and lateral images. The proximal femur was irradiated using X-ray imaging equipment to obtain two-dimensional projection images. On the anteroposterior image, a virtual guide pin projection was generated on the two-dimensional image plane according to the ideal screw direction determined by the surgical plan. The anteroposterior angle parameter was obtained by measuring the angle between the femoral neck axis and the virtual guide pin projection. Similarly, on the lateral image, the angle between the femoral neck axis projection and the virtual guide pin projection was measured to obtain the lateral angle parameter. The anteroposterior and lateral angle parameters were mapped back to the three-dimensional bone morphology model. According to the spatial relationship between the femoral neck axis and the femoral shaft central axis, the angle parameters were spatially corrected to obtain the incident angle of the screw in three-dimensional space, and this incident angle was used as the screw incident angle parameter.

[0068] For example, during the preoperative planning stage, under the determined first projection direction, in addition to acquiring anteroposterior and lateral two-dimensional image data, oblique two-dimensional image data of the proximal femur of the patient can also be acquired to supplement the spatial information under different projection angles. According to the ideal screw direction determined by the surgical plan, a virtual guide pin projection is generated on the oblique two-dimensional image plane. By measuring the angle between the femoral neck axis and the virtual guide pin projection, the oblique angle parameter is obtained. The angle parameters of the anteroposterior, lateral and oblique views are simultaneously mapped back to the three-dimensional bone morphology model. Through the spatial relationship between the femoral neck axis and the femoral shaft central axis, all angle parameters are spatially corrected to obtain the incident angle of the screw in three-dimensional space.

[0069] The neck-shaft angle, also known as the femoral neck axis, is the angle between the femoral neck axis and the femoral shaft axis. It is a crucial parameter reflecting the anatomical structure of the proximal femur. In three-dimensional space, the femoral neck axis is defined as the direction vector connecting the center of the femoral head to the femoral neck axis, and the femoral shaft axis is defined as the direction vector along the centerline extending longitudinally along the femoral shaft. The angle between these two axes is the neck-shaft angle. This angle directly determines the degree of inclination and weight-bearing path of the proximal femur, and is a key parameter affecting the implantation angle and fixation stability of proximal femoral internal fixation devices (such as proximal femoral compression plates and cannulated screws). Clinically… The normal range of the neck-shaft angle is generally 120°~135°. If it is too small, the femoral neck will tend to varus hip, increasing the risk of concentrated joint load. If it is too large, it will manifest as valgus hip, affecting the uniformity of stress distribution. During the intraoperative angle measurement and guidance positioning process, accurate identification of the neck-shaft angle can match the guide hole position and screw channel direction with the individual bone morphology of the patient, avoiding implantation deviation caused by fixed angle design. Therefore, the neck-shaft angle plays a benchmark reference role in the projection direction planning and guidance structure calibration of this application, and is the core parameter for determining the spatial correspondence between the femoral neck and femoral shaft.

[0070] The anteversion angle refers to the angle between the projection of the femoral neck axis onto the horizontal plane and the line connecting the posterior margin of the femoral condyles. It describes the rotational orientation of the femoral neck relative to the femoral shaft in the horizontal plane. Taking the line connecting the posterior margins of the two femoral condyles at the distal end of the femur as a reference line, the femoral neck axis is projected onto this plane, and the angle formed by the two is the anteversion angle. The anteversion angle reflects the torsional characteristics of the femoral neck relative to the femoral shaft and is a key parameter affecting the alignment of lower limb rotation, hip joint range of motion, and screw insertion direction. The anteversion angle of a normal adult is generally about 10°~20°. If the anteversion angle is too large, the femoral neck rotates significantly forward, which can easily lead to an increased risk of anterior hip dislocation. If the anteversion angle is too small or reversed, the femoral neck rotates insufficiently, which may affect the range of external rotation of the lower limb. In the simulation projection direction generation method proposed in this application, the anteversion angle is used to determine the correspondence between the X-ray projection path and the rotation of the femoral neck in the horizontal plane. Through spatial quantitative analysis of the anteversion angle, the coordinated matching of the projection angle and the femoral torsional structure can be achieved in preoperative simulation.

[0071] S104. Based on the three-dimensional bone morphology model and screw incident angle parameters, guide design parameters are generated. The surface curvature distribution and local geometric features of the greater trochanter, femoral neck, and femoral shaft are extracted based on the three-dimensional bone morphology model to calculate the fitting contour of the guide shell. This contour ensures that the guide can closely cover the bone surface and provide sufficient stable support during the operation, avoiding guide pin deviation caused by insufficient contact. At the same time, combined with the direction of the femoral shaft central axis, the installation angle of the fixation base is determined so that the guide can be stably fitted with the bone surface during the operation and ensure the convenience of guide pin operation. The combination of fitting contour and fixation base parameters forms the preliminary shape design of the guide, and the above parameter combination is used as the first design parameter.

[0072] The preoperatively measured and corrected screw incidence angle parameters are mapped onto a three-dimensional bone morphology model to generate a corresponding screw incidence vector and determine the three-dimensional spatial position of the incidence point. The screw incidence vector and the incidence point form the screw incidence path in the bone model, ensuring that the screw is accurately inserted along the predetermined direction during the operation. Based on this path, and combined with the first design parameters of the guide shell contour, the installation position and orientation tilt angle parameters of the guide hole on the shell are determined through spatial geometric calculations. The above installation position and orientation tilt angle are used as the second design parameters. The spatial position and orientation tilt angle of the guide hole are designed to guide the guide needle to puncture along the screw incidence path during the operation, avoiding deviation and accidental entry into the soft tissue area, and ensuring the accuracy of screw insertion.

[0073] After the guide hole parameters are determined, the sensor placement positions need to be planned based on the relative positions of the guide hole and the housing. The aforementioned sensor placement positions serve as the third design parameter. The sensors are used to monitor the guide needle deviation in real time during the operation and provide feedback for guide needle fine-tuning. By integrating parameters such as the guide housing, fixing base, guide hole, and sensor placement, a complete set of guide design parameters is formed. The aforementioned set of guide design parameters includes the aforementioned first design parameter, second design parameter, and third design parameter.

[0074] After obtaining the complete guide design parameters, the guide shell model is first constructed based on the shell contour design parameters. The specific method includes generating the shell fitting surface in 3D modeling software using the curvature data of the femoral greater trochanter, femoral neck and femoral shaft surfaces to ensure that the shell can tightly cover the bone surface and avoid intraoperative slippage. The thickness, strength and material selection of the shell model are set according to the surgical mechanics requirements to ensure that the guide has sufficient structural rigidity during operation, while not increasing the pressure on the patient's bone surface or obstructing the surgical operation space. According to the design parameters of the fixation base installation angle, a fixation base interface is created on the shell model for the stable installation of the guide during operation. The size and installation method of the base can match standard screws or clamps to ensure stable positioning on the bone surface and facilitate quick disassembly or fine adjustment during operation.

[0075] The guide hole design section is the core operation control unit. Based on the guide hole position parameters and orientation tilt parameters, the guide hole channel is established on the shell model. The channel diameter, length and wall thickness are designed according to the standard guide pin specifications and screw requirements. The guide hole is strictly aligned with the screw incident path in the three-dimensional model to ensure that the guide pin is inserted along the preset path and avoid angular deviation. For guides with multiple screw channels, multiple guide holes can be arranged in the model at the same time. The spatial position and orientation of each hole are calculated independently based on the corresponding screw incident angle.

[0076] Around the guide hole, a sensor mounting base is generated according to the sensor setting parameters. The spatial position and fixing method of the sensor mounting base ensure that the sensor can detect guide needle deviation during the surgical operation, including angular deviation and directional deviation, without interfering with the guide needle operation. The sensor interface can be designed to be pluggable or rotatable for intraoperative adjustment and maintenance.

[0077] This application constructs a three-dimensional bone morphology model of the proximal femur of the patient before surgery, and simulates the X-ray projection direction and the measured screw incident angle based on the model. The incident angle is then mapped to the guide design parameters to achieve precise layout of the guide shell, guide hole and sensor. This allows for quantifiable screw path planning before surgery, reducing the deviation of screw placement.

[0078] Example 2

[0079] In some possible implementations, in a 3D modeling environment, the guide shell model designed in Implementation 1 is initially aligned with the femoral surface along the fixed base interface, so that the shell fit contour covers the installable area of ​​the proximal femur, and computational geometry methods are used to evaluate the distribution of contact points, contact area and gap parameters between the guide shell and the bone surface, thereby quantifying the fit of the guide.

[0080] The spatial position of the guide hole on the outer shell is simulated. Based on the screw incident angle parameters obtained from preoperative measurements and corrections, the guide hole channel is projected onto a three-dimensional bone morphology model to check whether the guide hole can accurately guide the guide pin through the predetermined position of the femoral neck and femoral shaft along the screw incident path. For multi-hole guides, it is also necessary to simultaneously evaluate the spatial interference between each guide hole and its relative positional relationship with the bone surface to ensure that the multi-screw channel can be safely operated during surgery.

[0081] Based on the evaluation results of fit and guide hole positioning accuracy, the guide design parameters are adjusted. For example, when the contact area between the shell and the bone surface is insufficient or the local gap is too large, the shell contour curvature or shell thickness can be finely adjusted. When the guide hole channel deviates from the screw incident path or interferes with the bone structure, the installation position or tilt angle of the guide hole on the shell can be adjusted. After adjustment, the fit simulation is repeated until the guide fit meets the preset standard and the guide hole positioning accuracy meets the screw path requirements.

[0082] This application improves the fit accuracy of the guide on the patient's bone surface and the accuracy of the guide needle by simulating the three-dimensional bone morphology model and the guide model together before surgery, and adjusting the guide design parameters according to the fit and the positioning accuracy of the guide hole.

[0083] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of this application as claimed. The scope of protection of this application is defined by the appended claims and their equivalents.

Claims

1. A method for measuring and guiding the screw angle of a proximal femoral compression plate, characterized in that, The method includes: Before the operation, a three-dimensional bone morphology model of the proximal femur of the patient is constructed. In the three-dimensional bone morphology model, the spatial angle between the femoral neck axis and the central axis of the femoral shaft is measured. Based on the spatial angle, different projection directions of X-rays are simulated, and the projection direction with the angle between the femoral neck axis and the femoral neck axis in a preset range is selected as the first projection direction. Under the first projection direction, acquire two-dimensional image data of the proximal femur in anteroposterior and lateral views, measure the angle parameters between the femoral neck axis and the guide pin projection in the anteroposterior and lateral views of the two-dimensional image data, and correct the angle parameters to screw incident angle parameters according to the three-dimensional bone morphology model. Based on the three-dimensional bone morphology model and the screw incident angle parameters, the corresponding guide design parameters are determined. According to the guide design parameters, the corresponding guide model is designed. The guide model includes at least one guide hole and a sensor. The sensor is used to detect guide pin deviation during surgery, and the guide hole is used to adjust the guide pin direction during surgery.

2. The method according to claim 1, characterized in that, The process of determining the corresponding guide design parameters based on the three-dimensional bone morphology model and the screw incident angle parameters includes: Based on the three-dimensional bone morphology model, a first design parameter is determined, which includes the guide shell and the fixing base. The screw incident angle parameter is mapped onto the three-dimensional bone morphology model of the proximal femur of the patient to determine the second design parameter, which includes the installation position of the guide hole on the guide. Based on the first design parameters and the second design parameters, a third design parameter is determined, the third design parameter including the sensor's installation position; The first design parameter, the second design parameter, and the third design parameter are used as the corresponding guide design parameters.

3. The method according to claim 2, characterized in that, The step of determining the first design parameters based on the three-dimensional bone morphology model includes: Based on the three-dimensional bone morphology model, the surface curvature distribution and local geometric features of the greater trochanter of the femur, femoral neck, and femoral shaft are extracted. Based on the surface curvature distribution and the local geometric features, calculate the fitting contour design parameters of the guide housing; Based on the spatial orientation of the femoral shaft central axis, calculate the installation angle design parameters of the fixation base; The first design parameter is obtained by combining the fitting contour design parameter with the installation angle design parameter.

4. The method according to claim 3, characterized in that, The step of mapping the screw incident angle parameter to the three-dimensional bone morphology model of the proximal femur of the patient to determine the second design parameter includes: Based on the screw incident angle parameters, a screw incident vector is generated, and the screw incident vector is mapped onto the three-dimensional bone morphology model to determine the spatial position of the screw incident point. Based on the screw incident vector and the spatial position of the screw incident point, the incident path of the screw is obtained; Based on the incident path and the fitting contour design parameters of the guide housing, calculate the installation position parameters and direction tilt angle parameters of the guide hole on the guide housing; The installation position parameters and orientation tilt angle parameters are used as the second design parameters.

5. The method according to claim 4, characterized in that, The step of determining the third design parameter based on the first design parameter and the second design parameter includes: Based on the fitting contour design parameters of the guide housing and the installation position and directional tilt angle parameters of the guide hole, the sensor setting position is calculated and the setting position is used as the third design parameter.

6. The method according to claim 1, characterized in that, The step of simulating different X-ray projection directions based on the spatial angle, and selecting a projection direction whose angle with the femoral neck axis is within a preset range as the first projection direction, includes: Based on the spatial angle, a set of candidate projection directions is generated. For each candidate projection direction, the imaging process of X-ray is simulated, and the angle between the femoral neck axis and each candidate projection direction is calculated. The candidate projection direction whose angle with the femoral neck axis is within a preset range is selected as the first projection direction.

7. The method according to claim 1, characterized in that, The step involves acquiring two-dimensional image data of the proximal femur in anteroposterior and lateral views under the first projection direction, and measuring the angle parameters between the femoral neck axis and the guide pin projection in the anteroposterior and lateral views of the two-dimensional image data, including: Under the first projection direction, acquire two-dimensional image data of the proximal femur in anteroposterior and lateral views; On the anteroposterior two-dimensional image data, the angle between the femoral neck axis projection and the guide pin projection is measured to obtain the anteroposterior angle parameter; On the lateral two-dimensional imaging data, the angle between the femoral neck axis projection and the guide pin projection is measured to obtain the lateral angle parameter.

8. The method according to claim 7, characterized in that, The step of correcting the included angle parameter to the screw incident angle parameter based on the three-dimensional bone morphology model includes: The positive angle parameter and the lateral angle parameter are mapped into the three-dimensional bone morphology model. Based on the spatial relationship between the femoral neck axis and the femoral shaft central axis of the three-dimensional bone morphology model, the positive angle parameter and the lateral angle parameter are spatially corrected to obtain the incident angle of the screw in three-dimensional space. The incident angle is used as the screw incident angle parameter.

9. The method according to claim 7, characterized in that, Also includes: Under the first projection direction, acquire two-dimensional image data of the proximal femur in an oblique position, and measure the angle parameter between the femoral neck axis and the guide pin projection in the oblique position on the two-dimensional image data.

10. The method according to claim 1, characterized in that, Also includes: Before the operation, the three-dimensional bone morphology model and the guide model are simulated together to evaluate the fit of the guide model on the patient's bone surface and the positioning accuracy of the guide hole. The design parameters of the guide are adjusted according to the fit and the positioning accuracy of the guide hole.

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