A design method of a pedicle screw guide plate and a use method thereof

Abstract

The application provides a design method and use method of a pedicle screw guide plate, and belongs to the field of medical instruments, and comprises the following steps: extracting the cross-sectional profile of a target vertebra based on image scanning to obtain the long-axis vertex position and end-axis vertex position of the target vertebra; establishing a two-dimensional coordinate system through the long axis and the short axis of the target vertebra, fitting a standard ellipse equation according to the long-axis vertex and the short-axis vertex of the target vertebra; designing a guide plate base according to the bone surface between the two focal points of the standard ellipse equation; and performing parameterized modeling on the guide hole at the focal point position to obtain a guide plate; the guide hole is used for mounting a pedicle screw, and the technical scheme of the application realizes a significant breakthrough in terms of surgical precision, safety, efficiency, cost control and the like through accurate positioning and personalized guide plate design by mathematical modeling.

Description

Technical Field

[0001] This invention relates to the field of medical device design technology, and in particular to a design method and usage method of a pedicle screw guide plate. Background Technology

[0002] Traditional manual pedicle screw placement techniques rely on the surgeon holding a bone drill or incision tool, without a dedicated navigation device. The insertion point and angle are determined empirically based on anatomical landmarks (such as transverse processes and articular processes). Intraoperatively, repeated fluoroscopy with a C-arm X-ray machine is required to verify the pedicle screw position. Anatomical variations (such as pedicle stenosis or scoliosis) easily lead to misplacement, with a nerve injury rate as high as 5-15%. A single surgery requires 5-8 fluoroscopy sessions, and the cumulative radiation dose poses a threat to the health of both doctors and patients. Relying heavily on the surgeon's experience, novice surgeons have an accuracy rate of less than 70% in screw placement.

[0003] Universal pedicle screw navigation template technology typically uses standardized metal or plastic guide plates with pre-set guide holes at fixed angles, designed based on "average anatomical data." During surgery, it guides the screw into place after fitting against the vertebral body surface. However, it cannot accommodate individual anatomical differences (such as vertebral rotation or transverse process morphology variations), requiring repeated adjustments during the procedure, and its success rate is only 60-80%. Furthermore, the screw insertion direction does not consider bone density distribution, resulting in a high risk of pedicle screw loosening. It only provides one-dimensional or two-dimensional directional guidance and cannot correct for three-dimensional spatial deviations.

[0004] Image-guided navigation systems include optical trackers, intraoperative imaging equipment, and computer navigation software. Preoperative CT / MRI reconstructs a 3D model, and intraoperatively, an infrared camera tracks the real-time position of the instruments and bones. The surgeon places the screws according to the virtual path on the screen. However, the equipment purchase cost exceeds ten million yuan, making it difficult for small and medium-sized hospitals to adopt. Specialized training is required, and surgery time is extended by 20-30%. Intraoperative CT or X-ray verification is still necessary, and radiation concerns remain unresolved. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a design method and usage method for a pedicle screw guide plate, which eliminates human error through objective focal point positioning based on an elliptical mathematical model. Specifically, it includes:

[0006] A design method for a pedicle screw guide plate includes:

[0007] Based on image scanning, the cross-sectional contour of the target vertebra is extracted to obtain the position of the long axis vertex and the position of the end axis vertex of the target vertebra.

[0008] A two-dimensional coordinate system is established using the major and minor axes of the target vertices, and the standard ellipse equation is obtained by fitting the vertices of the major and minor axes of the target vertices.

[0009] The guide plate base is designed based on the bone surface between the two foci of the standard ellipse equation.

[0010] Parametric modeling of the guide hole is performed at the focal position to obtain the guide plate;

[0011] The guide hole is used to install the pedicle screw.

[0012] Optionally, the extraction of the cross-sectional contour of the target vertebra based on image scanning includes:

[0013] Based on the image data of the cross section of the target vertebral body from CT or MRI scans, the cross-sectional contour information of the target vertebral body is obtained;

[0014] Among them, the layer thickness is ≤1mm.

[0015] Optionally, the step of establishing a two-dimensional coordinate system through the major and minor axes of the target vertices, and fitting the standard ellipse equation based on the vertices of the major and minor axes of the target vertices, includes:

[0016] The geometric center of the cross-section of the target vertebra is defined as the origin, the major axis of the target vertebra is defined as the x-axis, and the minor axis of the target vertebra is defined as the y-axis.

[0017] Based on the cross-sectional contour information of the target vertebrae, a standard ellipse equation is fitted with the origin as the center, the major axis vertices of the two target vertebrae as the principal axis, and the minor axis vertices of the two target vertebrae as the secondary axis, and the positions of the two foci of the standard ellipse equation are obtained.

[0018] Optionally, the guide plate base, designed based on the bone surface between the two focal positions according to the standard ellipse equation, includes:

[0019] Based on the skeletal image between the two focal points of the standard ellipse equation, a guide plate base is obtained by 3D printing technology, which perfectly fits the skeletal surface between the two focal points of the standard ellipse equation.

[0020] Optionally, the step of parametrically modeling the guide hole at the focal position to obtain the guide plate includes:

[0021] The direction of each guide hole coincides with the line connecting the focal point of the ellipse on the same side and the secondary protrusion;

[0022] When modeling the guide hole for the positive x-axis, follow formula (1):

[0023] ;in, Let x be the direction vector of the guide hole along the positive x-axis. Let x be the x-coordinate of the vertex of the ellipse along the positive x-axis. The ordinate of the vertex of the ellipse is the positive x-axis;

[0024] When modeling the guide hole for the positive x-axis, follow formula (2):

[0025] ;in, Let x be the direction vector of the guide hole, which is the negative x-axis. Let x be the x-coordinate of the vertex of the ellipse along the negative x-axis. The ordinate of the vertex of the ellipse is the negative x-axis.

[0026] Guide holes are made on the guide plate base at the corresponding focal point based on the direction vectors of the guide holes of the positive x-axis and the negative x-axis to obtain the guide plate.

[0027] A method for using a pedicle screw guide plate, applied to the guide plate obtained by the above-mentioned design method for pedicle screw guide plates, comprising:

[0028] Obtain cross-sectional image data of the actual vertebral body, and generate a three-dimensional model of the actual vertebral body based on the cross-sectional image data of the actual vertebral body. The three-dimensional model of the actual vertebral body includes: spinous process, transverse process and articular process;

[0029] Based on the design method of pedicle screw guide plate, a guide plate model that conforms to the actual vertebral structure is obtained according to the cross-sectional image data of the actual vertebral body.

[0030] Based on the judgment of the actual vertebral structure, after the guide plate model is installed with the actual vertebral 3D model, whether the pedicle screw exceeds the safe distance between the pedicle screw and the pedicle cortex, where the safe distance between the pedicle screw and the pedicle cortex is 1mm;

[0031] If the safe distance is not exceeded, a guide plate is used to guide the pedicle screws into the actual vertebral body.

[0032] The above technical solution has at least the following advantages compared with the existing technology:

[0033] This invention transforms the geometric characteristics of the vertebral body cross-section into a quantifiable elliptical mathematical model. By positioning the focal point and associating it with anatomical landmarks, a 3D-printed personalized guide plate is designed to achieve precise and safe placement of pedicle screws. The technical solution of this invention, through precise positioning via mathematical modeling and personalized guide plate design, achieves significant breakthroughs in surgical precision, safety, efficiency, and cost control.

[0034] The focal coordinates are quantified by elliptical focal point positioning, eliminating subjective experience errors. A three-dimensional anatomical model is reconstructed based on the patient's CT data, with the guide plate base perfectly fitting the spinous and transverse processes (error <0.5mm), adapting to complex anatomical cases. The fit rate for complex cases such as spinal deformities, vertebral rotation, and osteoporosis is >99%.

[0035] The number of intraoperative fluoroscopy sessions is reduced from 5-8 to 1, resulting in an 80%-100% reduction in radiation dose. Finite element analysis (FEA) pre-verifies pathway safety (bone tunnel breakthrough risk <0.1%), eliminating the need for real-time intraoperative image correction. One-step guide plate guidance: the guide hole direction is directly generated by a mathematical model; the surgeon simply inserts the guide pin according to the hole.

[0036] Using medical-grade resin materials (such as DSM Somos NeXt), printing a single guide plate takes less than 4 hours, with a material cost of approximately 200 yuan. Once the guide plate is fixed, pins can be directly placed, eliminating the need for repeated angle adjustments. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is an image of a standard ellipse obtained by fitting the target vertebral body in a two-dimensional coordinate system.

[0039] Figure 2 A schematic diagram of the guide plate base installation from the first perspective, obtained by combining the standard elliptic equation;

[0040] Figure 3 A schematic diagram of the guide plate base installation from a second perspective, obtained by combining the standard elliptic equation;

[0041] Figure 4 A partial view of the guide plate;

[0042] Figure 5 Example of the target vertebral body in Sample 1 of Table 1;

[0043] Figure 6 Example of the target vertebral body in Sample 2 of Table 1;

[0044] Figure 7 Example of the target vertebral body in Sample 3 of Table 1;

[0045] Figure 8 This is an example of the target vertebral body in sample 4 of Table 1. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0047] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising,” “including,” or “including,” and similar terms mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or “connected,” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0048] Traditional pedicle screw placement relies on surgeon experience, posing a risk of nerve and blood vessel damage due to accidental pedicle penetration. Universal navigation templates have poor adaptability, making it difficult to match complex anatomical variations. Repeated fluoroscopic positioning during surgery is required, increasing radiation exposure and surgical time. Furthermore, current technologies lack precise positioning methods based on biomechanical symmetry and mathematical modeling of anatomical landmarks, and existing guides do not optimize screw insertion direction by incorporating the geometric characteristics of the vertebral body cross-section. Therefore, this embodiment provides a design method and usage method for a pedicle screw guide through creative experiments. By quantitatively analyzing vertebral body cross-sectional parameters using an elliptic mathematical model, the focal point positioning is correlated with bone density distribution, overcoming the limitations of purely morphological design in traditional guides and filling a technological gap in the field of "anatomical-mechanical co-optimization."

[0049] The details are as follows:

[0050] like Figures 1 to 4 As shown, a design method for a pedicle screw guide plate includes:

[0051] S1. Extract the cross-sectional contour of the target vertebra based on image scanning to obtain the position of the long axis vertex and the position of the end axis vertex of the target vertebra.

[0052] S2. Establish a two-dimensional coordinate system using the major and minor axes of the target vertices, and obtain the standard ellipse equation by fitting the vertices of the major and minor axes of the target vertices.

[0053] S3. The guide plate base is designed based on the bone surface between the two foci of the standard ellipse equation.

[0054] S4. Perform parametric modeling of the guide hole at the focal position to obtain the guide plate;

[0055] The guide hole is used to install the pedicle screw.

[0056] In one specific implementation, S1, the cross-sectional contour of the target vertebra is extracted based on image scanning to obtain the position of the long axis vertex and the position of the end axis vertex of the target vertebra, including:

[0057] Based on the image data of the cross section of the target vertebral body from CT or MRI scans, the cross-sectional contour information of the target vertebral body is obtained; wherein, the slice thickness is ≤1mm.

[0058] The specific procedure is as follows: Obtain cross-sectional image data of the target vertebral body (slice thickness ≤ 1mm) through CT or MRI scans, export it in DICOM format, and ensure the accuracy of extracting the geometric parameters (major axis and minor axis) for ellipse modeling by using high-resolution images. Use medical image processing software (such as Mimics, 3D Slicer) to segment the vertebral body cross-sectional contour, automatically identify the vertex coordinates of the major and minor axes, eliminate manual annotation errors, and ensure the objectivity of ellipse fitting.

[0059] In one specific implementation, S2, a two-dimensional coordinate system is established using the major and minor axes of the target vertebra, and a standard ellipse equation is obtained by fitting the vertices of the major and minor axes of the target vertebra, including:

[0060] The geometric center of the cross-section of the target vertebra is defined as the origin, the major axis of the target vertebra is defined as the x-axis, and the minor axis of the target vertebra is defined as the y-axis.

[0061] Based on the cross-sectional contour information of the target vertebrae, a standard ellipse equation is fitted with the origin as the center, the major axis vertices of the two target vertebrae as the principal axis, and the minor axis vertices of the two target vertebrae as the secondary axis, and the positions of the two foci of the standard ellipse equation are obtained.

[0062] The specific steps are as follows: Figure 1 A local coordinate system (xOy) is established with the geometric center of the vertebral cross-section as the origin, the major axis as the x-axis, and the minor axis as the y-axis. The extracted contour point set is fitted to a standard ellipse equation, which simplifies complex anatomical morphology into a computable geometric model. The major semi-axis a (distance from the vertex of the major axis to the origin) and the minor semi-axis b (distance from the vertex of the minor axis to the origin) are calculated. The focal length c is calculated using a formula. The focal coordinates are determined as M1(c,0) and M2(-c,0). The focal position is used as the reference point for the optimal mechanical path in the nail insertion direction.

[0063] In one specific implementation, S4, the guide plate base is designed based on the bone surface between the two foci of the standard ellipse equation, including:

[0064] Based on the skeletal image between the two focal points of the standard ellipse equation, a guide plate base is obtained by 3D printing technology, which perfectly fits the skeletal surface between the two focal points of the standard ellipse equation.

[0065] The guide plate is printed using medical-grade titanium alloy or biocompatible photosensitive resin (such as DSM Somos NeXt) through SLM (Selective Laser Melting) or SLA (Stereolithography) technology. This ensures the mechanical strength and sterilization safety of the guide plate.

[0066] In one specific implementation, S4, parametric modeling of the guide hole is performed at the focal position to obtain the guide plate, which includes:

[0067] The direction of each guide hole coincides with the line connecting the focal point of the ellipse on the same side and the secondary protrusion;

[0068] When modeling the guide hole for the positive x-axis, follow formula (1):

[0069] ;in, Let x be the direction vector of the guide hole along the positive x-axis. Let x be the x-coordinate of the vertex of the ellipse along the positive x-axis. The ordinate of the vertex of the ellipse is the positive x-axis;

[0070] When modeling the guide hole for the positive x-axis, follow formula (2):

[0071] ;in, Let x be the direction vector of the guide hole, which is the negative x-axis. Let x be the x-coordinate of the vertex of the ellipse along the negative x-axis. The ordinate of the vertex of the ellipse is the negative x-axis.

[0072] Guide holes are made on the guide plate base at the corresponding focal point based on the direction vectors of the guide holes of the positive x-axis and the negative x-axis to obtain the guide plate.

[0073] When this guide plate is installed with the mounting pin, the following steps must be met:

[0074] a. Expose the posterior structures of the target vertebral body and remove soft tissue.

[0075] b. Secure the guide plate to the spinous and transverse processes to ensure anatomical fit.

[0076] c. Drill the guide needle along the guide hole to a depth of the anterior 1 / 3 of the vertebral body (no fluoroscopy is required during the operation).

[0077] D. After removing the guide plate, insert the pedicle screw.

[0078] In addition, before using this guide plate, it is necessary to pre-assess whether the patient meets the requirements for using this guide plate. Therefore, this embodiment provides a method for using a pedicle screw guide plate, which is applied to the guide plate obtained by the above-mentioned pedicle screw guide plate design method, including:

[0079] Step 1: Obtain cross-sectional image data of the actual vertebral body, and generate a three-dimensional model of the actual vertebral body based on the cross-sectional image data. The three-dimensional model of the actual vertebral body includes: spinous process, transverse process and articular process; (This step can be performed simultaneously with step S1 in the above method, but the decision to start step S2 depends on the judgment result of this method.)

[0080] Step 2: Based on the design method of the pedicle screw guide plate, a guide plate model that conforms to the actual vertebral structure is obtained according to the cross-sectional image data of the actual vertebral body;

[0081] Step S3: Simulate the pedicle screw insertion process in software mimics or 3-matic, analyze the stress distribution in the bone tunnel, and determine whether the pedicle screw breaks through the pedicle cortex after the guide plate model of the actual vertebral body structure is installed with the actual vertebral body three-dimensional model. The safe distance between the pedicle screw and the pedicle cortex is 1mm.

[0082] If the pedicle cortex is not breached, a guide plate is used to guide the pedicle screws into the actual vertebral body.

[0083] Steps 1 to 3 are for preoperative risk assessment to avoid neurovascular damage.

[0084] Taking L4 pedicle screw placement as an example:

[0085] 1. Data acquisition: CT slice thickness 0.5mm, extract the major axis vertex A1(24,0) and minor axis vertex B1(0,16) of the cross section.

[0086] 2. Ellipse modeling: Calculated a=24mm, b=16mm, focal point M1(18.3,0).

[0087] 3. Guide plate generation: Connect the root of the transverse protrusion P(10.5,-3) to M1 to generate a guide hole, and verify the safety of the path using finite element analysis.

[0088] 4. Postoperative verification: CT showed that the pedicle screw was completely located within the pedicle, with a deviation from the preset path of <0.8mm.

[0089] In addition, relevant statistics were conducted on the elliptical modeling method used in this scheme and the existing pedicle screw placement method. A total of 15 samples were selected for comparison, and the data are shown in Table 1.

[0090] Table 1:

[0091]

[0092] Figures 5 to 8 Measurement charts for the first 4 cases (samples 1 to 4):

[0093] The red line represents the nail insertion direction calculated based on elliptical focus modeling, while the blue line represents the nail insertion direction simulated using medical imaging modeling software (mimics, 3-matic) after multiple attempts and optimizations using conventional methods. The comparison shows that the nail insertion angle deviation of both methods is within 3°. Based on the above data, the existing pedicle screw placement method meets the requirements of this elliptical modeling approach. (The advantage of this approach is that the optimal nail insertion direction can be directly calculated through elliptical modeling, eliminating the need for extensive subjective experience-based trials and adjustments in software.)

[0094] This technical solution systematically addresses the issues of accuracy, safety, and cost in pedicle screw placement through a complete innovation chain encompassing mathematical modeling, guide plate design, and intraoperative guidance, providing a revolutionary tool for spinal surgery.

[0095] This invention transforms the geometric characteristics of the vertebral body cross-section into a quantifiable elliptical mathematical model. By positioning the focal point and associating it with anatomical landmarks, a 3D-printed personalized guide plate is designed to achieve precise and safe placement of pedicle screws. The technical solution of this invention, through precise positioning via mathematical modeling and personalized guide plate design, achieves significant breakthroughs in surgical precision, safety, efficiency, and cost control.

[0096] The focal coordinates are quantified by elliptical focal point positioning, eliminating subjective experience errors. A three-dimensional anatomical model is reconstructed based on the patient's CT data, with the guide plate base perfectly fitting the spinous and transverse processes (error <0.5mm), adapting to complex anatomical cases. The fit rate for complex cases such as spinal deformities, vertebral rotation, and osteoporosis is >99%.

[0097] The number of intraoperative fluoroscopy sessions is reduced from 5-8 to 1, resulting in an 80%-100% reduction in radiation dose. Finite element analysis (FEA) pre-verifies pathway safety (bone tunnel breakthrough risk <0.1%), eliminating the need for real-time intraoperative image correction. One-step guide plate guidance: the guide hole direction is directly generated by a mathematical model; the surgeon simply inserts the guide pin according to the hole.

[0098] Using medical-grade resin materials (such as DSM Somos NeXt), printing a single guide plate takes less than 4 hours, with a material cost of approximately 200 yuan. Once the guide plate is fixed, pins can be directly placed, eliminating the need for repeated angle adjustments.

[0099] This invention deeply couples mathematical models with clinical anatomy, unifying and quantifying vertebral geometry (elliptical parameters) and biomechanics (bone density distribution), creating a fully digital closed-loop process: from image processing and focus calculation to guide plate printing, enabling data-driven surgery. This invention also democratizes low-cost technology: replacing high-end equipment with 3D printing, making precision surgery accessible in primary care hospitals.

[0100] The following points need to be explained:

[0101] (1) The accompanying drawings of the embodiments of the present invention only involve the structures involved in the embodiments of the present invention. Other structures can refer to the general design.

[0102] (2) For clarity, the thickness of layers or regions is enlarged or reduced in the drawings used to describe embodiments of the invention, i.e., these drawings are not drawn to scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element or there may be intermediate elements.

[0103] (3) Where there is no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0104] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A design method for a pedicle screw guide plate, characterized in that, include: Based on image scanning, the cross-sectional contour of the target vertebra is extracted to obtain the positions of the major axis vertices and minor axis vertices of the target vertebra. A two-dimensional coordinate system is established using the major and minor axes of the target vertices. The standard ellipse equation is obtained by fitting the vertices of the major and minor axes of the target vertices. The geometric center of the cross-section of the target vertebra is defined as the origin, the major axis of the target vertebra is defined as the x-axis, and the minor axis of the target vertebra is defined as the y-axis. Based on the cross-sectional contour information of the target vertebrae, a standard ellipse equation is fitted with the origin as the center, the major axis vertices of the two target vertebrae as the principal axis, and the minor axis vertices of the two target vertebrae as the secondary axis, and the positions of the two foci of the standard ellipse equation are obtained. The guide plate base is designed based on the bone surface between the two foci of the standard ellipse equation. Parametric modeling of the guide hole is performed at the focal position to obtain the guide plate; The guide hole is used to install the pedicle screw; The step of parametrically modeling the guide hole at the focal position to obtain the guide plate includes: The direction of each guide hole coincides with the line connecting the focal point of the ellipse on the same side and the secondary protrusion; When modeling the guide hole for the positive x-axis, follow formula (1): ；（1） in, Let x be the direction vector of the guide hole along the positive x-axis. Let x be the x-coordinate of the vertex of the ellipse along the positive x-axis. The ordinate of the vertex of the ellipse is the positive x-axis; When modeling the guide hole for the negative x-axis, follow formula (2): ；（2） in, Let x be the direction vector of the guide hole, which is the negative x-axis. Let x be the x-coordinate of the vertex of the ellipse along the negative x-axis. y is the ordinate of the vertex of the ellipse on the negative x-axis, and c is the distance from the focus M1 or focus M2 of the ellipse to the origin of the ellipse. Guide holes are made on the guide plate base at the corresponding focal point based on the direction vectors of the guide holes of the positive x-axis and the negative x-axis to obtain the guide plate.

2. The design method of the pedicle screw guide plate according to claim 1, characterized in that, The method of extracting the cross-sectional contour of the target vertebra based on image scanning includes: Based on the image data of the cross section of the target vertebral body from CT or MRI scans, the cross-sectional contour information of the target vertebral body is obtained; Among them, the layer thickness is ≤1mm.

3. The design method of the pedicle screw guide plate according to claim 2, characterized in that, The guide plate base, designed based on the bone surface between the two foci of the standard ellipse equation, includes: Based on the skeletal image between the two focal points of the standard ellipse equation, a guide plate base is obtained by 3D printing technology, which perfectly fits the skeletal surface between the two focal points of the standard ellipse equation.

4. A method of using a pedicle screw guide plate, characterized in that, The guide plate, applied to the design method of the pedicle screw guide plate according to any one of claims 1 to 3, comprises: Obtain cross-sectional image data of the actual vertebral body, and generate a three-dimensional model of the actual vertebral body based on the cross-sectional image data of the actual vertebral body. The three-dimensional model of the actual vertebral body includes: spinous process, transverse process and articular process; Based on the design method of pedicle screw guide plate, a guide plate model that conforms to the actual vertebral structure is obtained according to the cross-sectional image data of the actual vertebral body. Based on the judgment of the actual vertebral structure, after the guide plate model is installed with the actual vertebral 3D model, whether the pedicle screw exceeds the safe distance between the pedicle screw and the pedicle cortex, where the safe distance between the pedicle screw and the pedicle cortex is 1mm; If the safe distance is not exceeded, a guide plate is used to guide the pedicle screws into the actual vertebral body.

Images