A method and system for intelligent osteotomy and correction of lower limbs before 3D surgery

Abstract

The present invention provides a method and system for intelligent osteotomy and correction of lower limbs before 3D surgery, including: a feature point acquisition module, a mechanical axis construction module, a joint line construction module, a measurement module, an anatomical axis construction module, a cutting surface positioning module, an osteotomy module, a rotation axis determination module, a correction angle determination module, an automatic correction module, and a manual adjustment module. The present invention can achieve three-dimensional precise measurement through the measurement module; the positioning accuracy during the operation can be improved through the cutting surface positioning module, and the success rate and safety of the operation can be increased; and the surgical prediction model of coronal valgus deformity and coronal angular deformity of the lower limbs can be established through the simulated osteotomy, automatic correction and manual adjustment modules.

Description

Technical Field

[0001] The present invention relates to the field of intelligent diagnosis and treatment technology, and in particular to a method and system for lower limb 3D preoperative intelligent osteotomy and correction. Background Art

[0002] The main functions of the lower limbs are weight-bearing and walking, so maintaining the balance of lower limb length and restoring the normal axis of the lower limbs are particularly important in the treatment of various bone and joint deformities or fractures. At present, osteotomy is a commonly used treatment method for lower limb long bone deformities such as coronal plane valgus and coronal plane angulation. The key to the therapeutic effect of lower limb orthopedic surgery lies in the design of a perfect surgical plan and the precise control of the osteotomy site, osteotomy angle and amount. However, traditional osteotomy orthopedic surgery is difficult to achieve correction in three-dimensional space, has obvious deficiencies in accuracy, and cannot simulate the postoperative tissue morphology before surgery.

[0003] Through the above analysis, the problems and defects of the existing technology are: the two-dimensional plane measurement method is not comprehensive and accurate enough, the postoperative correction results cannot be predicted, and the surgical plan design time is long. Summary of the invention

[0004] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and provide a lower limb 3D preoperative intelligent osteotomy and correction method and system, which can achieve three-dimensional precise measurement and correction.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a lower limb 3D preoperative intelligent osteotomy correction method, comprising the following steps:

[0007] S1. Import the healthy bone and deformed bone STL models generated by CT data into the lower limb 3D preoperative intelligent osteotomy correction system;

[0008] S2, collecting spatial position information of joint center points of the manually selected model through a feature point collection module, and constructing a mechanical axis through a mechanical axis construction module using the collected spatial position information of the joint center points;

[0009] S3, collecting spatial position information of joint line constituent points of the manually selected model through the feature point collection module, and constructing joint lines through the joint line construction module using the collected spatial position information of the joint line constituent points;

[0010] S4, automatically calculating the bone length, joint running direction angle and mechanical axis offset value formed between the joint line of the deformed bone model before correction and the deformed mechanical axis through the measurement module;

[0011] S5, collecting spatial position information of two diaphysis midpoints of the proximal diaphysis midline and two diaphysis midpoints of the distal diaphysis midline of the manually selected deformed bone model through a feature point collection module, and constructing a proximal anatomical axis and a distal anatomical axis on the deformed bone model using the collected spatial position information of the two diaphysis midpoints of the proximal diaphysis midline and the two diaphysis midpoints of the distal diaphysis midline through an anatomical axis construction module;

[0012] S6, setting a cutting surface at the angle bisector of the intersection formed by the proximal anatomical axis and the distal anatomical axis through a cutting surface positioning module; performing osteotomy at the cutting surface through an osteotomy module to generate a proximal deformed bone block and a distal deformed bone block;

[0013] S7, determining the rotation axis according to two extreme points of the cutting surface contour line on the maximum deformity surface through the rotation axis determination module, calculating the correction angle according to the angle between the rotation axis and the expected joint center point through the correction angle determination module, and adjusting the position of the deformed bone block according to the correction angle so that the adjusted deformed bone block is in a pre-set standard position;

[0014] S8. The measurement module is used to automatically calculate the bone length, joint running angle and mechanical axis offset value of the deformed bone model after automatic correction. The manual adjustment module is used to manually fine-tune the angle according to the joint running angle of the deformed bone after correction. During the adjustment process, the system provides real-time data of the correction angle and generates the final correction plan.

[0015] Further, in S2, the joint center point includes the femoral head center point, the knee joint center point and the ankle joint center point;

[0016] The mechanical axis includes the correct mechanical axis of the lower limb, the mechanical axis of the entire lower limb, the mechanical axis of the femur and the mechanical axis of the tibia, and is specifically constructed as follows:

[0017] S101, automatically construct a straight line from the center of the femoral head to the center of the ankle joint as the mechanical axis of the entire lower limb;

[0018] Automatically construct a straight line from the center of the femoral head to the center of the knee joint as the mechanical axis of the femur;

[0019] Automatically construct a straight line from the center of the knee joint to the center of the bare joint as the tibial mechanical axis;

[0020] S102, femoral deformity, automatically construct the tibial mechanical axis extension line as the correct mechanical axis of the lower limb;

[0021] S103, tibial deformity, automatically construct the femoral mechanical axis extension line as the correct mechanical axis of the lower limb;

[0022] Further, in S3, the points constituting the joint line include the lowest point of the medial femoral condyle, the lowest point of the lateral femoral condyle, the medial point of the tibial plateau plane, the lateral point of the tibial plateau plane, the medial end point of the distal tibial subchondral bone line, and the lateral end point of the distal tibial subchondral bone line;

[0023] The joint lines include the proximal femoral joint line, the distal femoral joint line, the proximal tibia joint line, and the distal tibia joint line, and are specifically constructed as follows:

[0024] Automatically construct the femoral head horizontal line as the proximal femoral joint line;

[0025] Automatically construct the line between the lowest points of the medial and lateral femoral condyles as the distal femoral joint line;

[0026] The line connecting the inner and outer points of the tibial plateau plane is automatically constructed as the proximal tibial joint line;

[0027] The line connecting the inner and outer end points of the tibial subchondral bone line is automatically constructed as the distal tibial joint line.

[0028] Further, said S4, bone length includes the total lower limb length, femur length and tibia length;

[0029] The joint travel direction angle includes:

[0030] Proximal femoral mechanical lateral angle ∠mLPFA,

[0031] Distal femoral mechanical lateral angle ∠mLDFA,

[0032] Proximal tibia mechanical medial angle ∠mMPTA,

[0033] Distal tibia mechanical lateral angle ∠mLDTA

[0034] The angle between the knee joint line and the knee joint line is ∠JLCA.

[0035] The bone length:

[0036] The total length of the lower limb is calculated by the straight-line distance from the center of the femoral head to the center of the ankle joint.

[0037] The femur length is automatically calculated by the straight-line distance from the center of the femoral head to the center of the knee joint.

[0038] The tibia length is automatically calculated by the straight-line distance from the center of the knee joint to the center of the ankle joint;

[0039] Mechanical axis offset value:

[0040] The mechanical axis offset value is automatically calculated by the vertical distance between the knee joint center and the mechanical axis of the entire lower limb.

[0041] Further, in 5, the proximal anatomical axis is a line connecting two backbone midpoints on the proximal backbone midline, and the distal anatomical axis is a line connecting two backbone midpoints on the distal backbone midline.

[0042] Further, in S7, the maximum deformity surface is composed of the center point of the femoral head, the center point of the knee joint and the center point of the ankle joint;

[0043] The deformed bone block includes a distal deformed bone block and a proximal deformed bone block, wherein:

[0044] Femoral deformity is divided into proximal femoral deformity bone fragment and distal femoral deformity bone fragment after osteotomy. The position of the proximal femoral deformity bone fragment needs to be adjusted.

[0045] Tibial deformity is divided into proximal tibial deformity bone block and distal tibial deformity bone block after osteotomy. What needs to be adjusted is the position of the distal tibial deformity bone block.

[0046] Further, in S7, the method for determining the rotation axis is:

[0047] S701, projecting all points on the cutting surface contour line onto the maximum deformity surface;

[0048] S702, finding two extreme points along the X-axis direction on the maximum deformity surface, the direction of the rotation axis is perpendicular to the maximum deformity surface, and the position of the rotation axis is determined by the position of the extreme points.

[0049] Further, in said S7, the expected joint center point includes the femoral head center point of the correct mechanical axis of the lower limb and the ankle joint center point of the correct mechanical axis of the lower limb;

[0050] The method for calculating the correction angle comprises:

[0051] Femoral deformity

[0052] Automatically select a point on the extension line of the tibia mechanical axis that is equal to the femoral mechanical axis as the center point of the femoral head of the correct mechanical axis of the lower limb;

[0053] Calculate the angle between the rotation axis and the center point of the femoral head on the correct mechanical axis of the lower limb to automatically calculate the correction angle of the distal deformed bone block;

[0054] Tibial deformity

[0055] Automatically select a point on the extension line of the femoral mechanical axis that is equal to the tibial mechanical axis as the center point of the ankle joint of the correct mechanical axis of the lower limb;

[0056] The angle between the rotation axis and the center point of the ankle joint on the correct mechanical axis of the lower limb is calculated to automatically calculate the correction angle of the distal deformed bone block.

[0057] The present invention also provides a lower limb 3D preoperative intelligent osteotomy and correction system, which implements a lower limb 3D preoperative intelligent osteotomy and correction method, and:

[0058] A feature point acquisition module is used to acquire the spatial position information of manually selected joint center points, joint line constituent points, two backbone midpoints of the proximal backbone midline, and two backbone midpoints of the distal backbone midline;

[0059] Mechanical axis building module, used to build the correct mechanical axis of the lower limbs and the mechanical axis of the lower limb deformity;

[0060] The joint line construction module is used to construct the femoral head horizontal line, the distal femoral joint line, the proximal tibial joint line and the distal tibial joint line;

[0061] A measurement module, used to measure the total lower limb length, femur length, tibia length, joint running direction angle and mechanical axis deviation value of the deformed bone before and after correction;

[0062] An anatomical axis building module, used to build a proximal anatomical axis and a distal anatomical axis;

[0063] A cutting surface positioning module, used for locating the cutting surface position;

[0064] An osteotomy module, used for osteotomizing deformed bones at the cutting surface position;

[0065] A rotation axis determination module is used to set the rotation axis at the extreme point of the cutting surface;

[0066] A correction angle determination module is used to determine the angle that needs to be corrected for the distal deformed bone block;

[0067] An automatic correction module is used to automatically correct the distal deformed bone block to the expected set position;

[0068] The manual adjustment module is used to manually fine-tune the position of the distal deformed bone block.

[0069] The beneficial effects of the present invention are as follows: the measurement and correction of the mechanical axis of the lower limbs are not limited to a two-dimensional plane, but can achieve three-dimensional precise measurement and correction;

[0070] The cutting surface positioning module can improve the positioning accuracy during surgery, increase the success rate and safety of surgery;

[0071] Combining simulated osteotomy, automatic correction and manual adjustment modules with surgery can establish a surgical prediction model for lower limb coronal plane valgus and valgus deformity and lower limb coronal plane angular deformity, providing a scientific basis for future surgeries;

[0072] The operation process is relatively procedural, which is convenient for guiding more young doctors with less experience to master some complex and difficult operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 It is a flow chart of the intelligent correction method for 3D osteotomy of lower limbs provided by an embodiment of the present invention.

[0074] Figure 2 This is a diagram of the deformed bone and healthy bone model of the patient before correction in Example 1.

[0075] Figure 3 It is a schematic diagram of the correct mechanical axis of the patient's lower limb, the mechanical axis of the entire lower limb, the mechanical axis of the femur and the mechanical axis of the tibia in Example 1.

[0076] Figure 4 It is a schematic diagram of the patient's proximal femoral joint line, distal femoral joint line, proximal tibia joint line and distal tibia joint line in Example 1.

[0077] Figure 5 It is the anatomical axis of the proximal femur and the anatomical axis of the distal femur of the patient in Example 1.

[0078] Figure 6 It is a schematic diagram of the positioning position of the cutting plane in the first embodiment.

[0079] Figure 7 It is a schematic diagram of the cutting plane in the first embodiment.

[0080] Figure 8 This is a schematic diagram of determining the rotation axis in the first embodiment.

[0081] Fig. 9 This is a schematic diagram of simulated surgical resetting after automatic correction in the first embodiment.

[0082] Fig.10 This is a diagram of the deformed bone and healthy bone model of the patient before correction in Example 2.

[0083] Fig.11 This is a schematic diagram of simulated surgical resetting after automatic correction in the second embodiment. DETAILED DESCRIPTION

[0084] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0085] Embodiment 1

[0086] A 3D preoperative intelligent osteotomy correction method for lower limbs, such as Figure 1 As shown, the following steps are included:

[0087] S1, import the healthy bone and deformed bone STL models generated by CT data into the lower limb 3D preoperative intelligent osteotomy correction system. In this embodiment, the patient's healthy tibia STL model and deformed femur STL model are imported, such as Figure 2 shown.

[0088] S2, through the feature point acquisition module, collect the spatial position information of the joint center points of the manually selected model; and through the mechanical axis construction module, use the collected spatial position information of the joint center points to construct the mechanical axis. In this embodiment, the mechanical axis is automatically constructed based on the spatial position information of the manually selected joint center points, such as Figure 3 As shown, axis 1 is the mechanical axis of the entire lower limb, axis 2 is the mechanical axis of the femur, axis 3 is the mechanical axis of the tibia, and axis 4 is the correct mechanical axis of the lower limb.

[0089] S3, using the feature point acquisition module to acquire the spatial position information of the joint line constituent points of the manually selected model; and using the joint line construction module to construct the joint line using the acquired spatial position information of the joint line constituent points. In this embodiment, the joint line is automatically constructed based on the spatial position information of the manually selected joint line constituent points, such as Figure 4 As shown, joint line 5 is the proximal femoral joint line, joint line 6 is the distal femoral joint line, joint line 7 is the proximal tibia joint line, and joint line 8 is the distal tibia joint line.

[0090] S4, through the measurement module, automatically calculate the joint running direction angle, bone length and mechanical axis offset value formed between the joint line of the deformed bone model before correction and the deformed mechanical axis. In this embodiment, the joint running direction angle, bone length and mechanical axis offset value before correction are automatically calculated. The joint running direction angle ∠mLPFA before correction is 73.0°, ∠LDFA is 106.4°, ∠JLCA is 0.5°, ∠mMPTA is 87.7°, and ∠mLDTA is 90.0°. Among the automatically calculated bone lengths, the total lower limb length is 694.6 mm, the femur length is 376.5 mm, and the tibia length is 328.0 mm. The automatically calculated mechanical axis offset value is 58.5 mm.

[0091] S5, using the feature point acquisition module, collects the spatial position information of the two midpoints of the proximal midline and the two midpoints of the distal midline of the manually selected deformed bone model; using the anatomical axis construction module, the proximal anatomical axis and the distal anatomical axis are constructed on the deformed bone model using the collected spatial position information of the two midpoints of the proximal midline and the two midpoints of the distal midline. In this embodiment, Figure 5 As shown, axis 9 is the anatomical axis of the proximal femur, and axis 10 is the anatomical axis of the distal femur.

[0092] S6, using the cutting surface positioning module to set a cutting surface at the angular bisector of the intersection formed by the proximal anatomical axis and the distal anatomical axis; using the osteotomy module to perform osteotomy at the cutting surface to generate a proximal deformed bone block and a distal deformed bone block. In this embodiment, Figure 6 As shown in the figure, the cutting plane is located at the bisector of the angle formed by the intersection of the proximal femoral anatomical axis and the distal femoral anatomical axis. Figure 7 The figure shows a schematic diagram of the cutting surface.

[0093] S7, the rotation axis is determined by the rotation axis determination module according to the two extreme points of the cutting surface contour line on the maximum deformity surface; the correction angle determination module calculates the correction angle according to the angle between the rotation axis and the expected joint center; the automatic correction module adjusts the position of the deformed bone block according to the correction angle, so that the adjusted deformed bone block is in a pre-set standard position. In this embodiment, Figure 8 As shown, shaft 11 is a rotation axis. Fig. 9 As shown, after osteotomy, the bone is divided into the proximal femoral deformity bone block and the distal femoral deformity bone block, and the position of the proximal femoral deformity bone block is adjusted.

[0094] S8, through the measurement module, automatically calculates the joint running angle, bone length and mechanical axis offset value of the deformed bone model after automatic correction; through the manual adjustment module, manually fine-tune the angle according to the joint running angle of the deformed bone after correction. During the adjustment process, the system provides real-time data of the correction angle and generates the final correction plan. In this implementation case, the joint running angle ∠mLPFA of the corrected model is 91.6°, ∠LDFA is 87.8°, ∠JLCA is 0.5°, ∠mMPTA is 87.7°, and ∠mLDTA is 90.0°. Among the automatically calculated bone lengths, the total lower limb length is 716.0 mm, the femur length is 388.0 mm, and the tibia length is 328.0 mm. The automatically calculated mechanical axis offset value is 1.9 mm. Fig. 9 Shown is a schematic diagram of simulated surgical reduction after automatic correction.

[0095] Example 2 II

[0096] Tibial angular deformity

[0097] A method for intelligent osteotomy and correction of lower limbs before 3D surgery, the other features of which are the same as those of Example 1, except that:

[0098] In step S2, a mechanical axis is constructed. Specifically, the correct mechanical axis of the lower limb is the extension line of the femoral mechanical axis.

[0099] In step S5, an anatomical axis is constructed, specifically, a proximal tibia anatomical axis and a distal tibia anatomical axis are constructed;

[0100] In step S6, a cutting plane is set, and the specific position of the cutting plane is at the bisector of the intersection formed by the proximal tibia anatomical axis and the distal tibia anatomical axis;

[0101] In step S7, the correction angle is calculated according to the angle between the rotation axis and the expected joint center, wherein the expected joint center is specifically the ankle joint center of the correct mechanical axis of the lower limb. The position of the deformed bone block is adjusted according to the correction angle, and after osteotomy, it is divided into the proximal tibia deformed bone block and the distal tibia deformed bone block, and the position of the distal tibia deformed bone block is specifically adjusted.

[0102] The above-mentioned embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be based on the attached claims.

Claims

1. A method for intelligent osteotomy and correction of lower limbs before 3D surgery, characterized in that: The following steps are involved: S1. Import the healthy bone and deformed bone STL models generated by CT data into the lower limb 3D preoperative intelligent osteotomy correction system; S2, collecting spatial position information of joint center points of the manually selected model through a feature point collection module, and constructing a mechanical axis through a mechanical axis construction module using the collected spatial position information of the joint center points; S3, collecting spatial position information of joint line constituent points of the manually selected model through the feature point collection module, and constructing joint lines through the joint line construction module using the collected spatial position information of the joint line constituent points; S4, automatically calculating the bone length, joint running direction angle and mechanical axis offset value formed between the joint line of the deformed bone model before correction and the deformed mechanical axis through the measurement module; S5, collecting spatial position information of two diaphysis midpoints of the proximal diaphysis midline and two diaphysis midpoints of the distal diaphysis midline of the manually selected deformed bone model through a feature point collection module, and constructing a proximal anatomical axis and a distal anatomical axis on the deformed bone model using the collected spatial position information of the two diaphysis midpoints of the proximal diaphysis midline and the two diaphysis midpoints of the distal diaphysis midline through an anatomical axis construction module; S6, setting a cutting surface at the angle bisector of the intersection formed by the proximal anatomical axis and the distal anatomical axis through a cutting surface positioning module; performing osteotomy at the cutting surface through an osteotomy module to generate a proximal deformed bone block and a distal deformed bone block; S7, determining the rotation axis according to two extreme points of the cutting surface contour line on the maximum deformity surface through the rotation axis determination module, calculating the correction angle according to the angle between the rotation axis and the expected joint center point through the correction angle determination module, and adjusting the position of the deformed bone block according to the correction angle so that the adjusted deformed bone block is in a pre-set standard position; S8. The measurement module is used to automatically calculate the bone length, joint running angle and mechanical axis offset value of the deformed bone model after automatic correction. The manual adjustment module is used to manually fine-tune the angle according to the joint running angle of the deformed bone after correction. During the adjustment process, the system provides real-time data of the correction angle and generates the final correction plan.

2. A method for lower limb 3D preoperative intelligent osteotomy and correction according to claim 1, characterized in that: In S2, the joint center point includes the femoral head center point, the knee joint center point and the ankle joint center point; The mechanical axis includes the correct mechanical axis of the lower limb, the mechanical axis of the entire lower limb, the mechanical axis of the femur and the mechanical axis of the tibia, and is specifically constructed as follows: S101, automatically construct a straight line from the center of the femoral head to the center of the ankle joint as the mechanical axis of the entire lower limb; Automatically construct a straight line from the center of the femoral head to the center of the knee joint as the mechanical axis of the femur; Automatically construct a straight line from the center of the knee joint to the center of the bare joint as the tibial mechanical axis; S102, femoral deformity, automatically construct the tibial mechanical axis extension line as the correct mechanical axis of the lower limb; S103, tibial deformity, automatically construct the femoral mechanical axis extension line as the correct mechanical axis of the lower limb.

3. The method for 3D preoperative intelligent osteotomy and correction of lower limbs according to claim 1, characterized in that: Said S3, said joint line constituent points include the lowest point of the medial femoral condyle, the lowest point of the lateral femoral condyle, the medial point of the tibial plateau plane, the lateral point of the tibial plateau plane, the medial end point of the distal tibial subchondral bone line, and the lateral end point of the distal tibial subchondral bone line; The joint lines include the proximal femoral joint line, the distal femoral joint line, the proximal tibia joint line, and the distal tibia joint line, and are specifically constructed as follows: Automatically construct the femoral head horizontal line as the proximal femoral joint line; Automatically construct the line between the lowest points of the medial and lateral femoral condyles as the distal femoral joint line; The line connecting the inner and outer points of the tibial plateau plane is automatically constructed as the proximal tibial joint line; The line connecting the inner and outer end points of the tibial subchondral bone line is automatically constructed as the distal tibial joint line.

4. The method for 3D preoperative intelligent osteotomy and correction of lower limbs according to claim 1, characterized in that: The S4, bone length includes the total lower limb length, femur length and tibia length; The joint travel direction angle includes: Proximal femoral mechanical lateral angle ∠mLPFA, Distal femoral mechanical lateral angle ∠mLDFA, Proximal tibia mechanical medial angle ∠mMPTA, Distal tibia mechanical lateral angle ∠mLDTA The angle between the knee joint line and the knee joint line is ∠JLCA; The bone length: The total length of the lower limb is calculated by the straight-line distance from the center of the femoral head to the center of the ankle joint. The femur length is automatically calculated by the straight-line distance from the center of the femoral head to the center of the knee joint. The tibia length is automatically calculated by the straight-line distance from the center of the knee joint to the center of the ankle joint; Mechanical axis offset value: The mechanical axis offset value is automatically calculated by the vertical distance between the knee joint center and the mechanical axis of the entire lower limb.

5. The method for 3D preoperative intelligent osteotomy and correction of lower limbs according to claim 1, characterized in that: In S5, the proximal anatomical axis is a line connecting two diaphysis midpoints on the proximal diaphysis midline, and the distal anatomical axis is a line connecting two diaphysis midpoints on the distal diaphysis midline.

6. The method for 3D preoperative intelligent osteotomy and correction of lower limbs according to claim 1, characterized in that: Said S7, said maximum deformity surface is formed by the center point of the femoral head, the center point of the knee joint and the center point of the ankle joint; The deformed bone block includes a distal deformed bone block and a proximal deformed bone block, wherein: Femoral deformity is divided into proximal femoral deformity bone fragment and distal femoral deformity bone fragment after osteotomy. The position of the proximal femoral deformity bone fragment needs to be adjusted. Tibial deformity is divided into proximal tibial deformity bone block and distal tibial deformity bone block after osteotomy. What needs to be adjusted is the position of the distal tibial deformity bone block.

7. The method for lower limb 3D preoperative intelligent osteotomy and correction according to claim 1, characterized in that: In S7, the method for determining the rotation axis is: S701, projecting all points on the cutting surface contour line onto the maximum deformity surface; S702, finding two extreme points along the X-axis direction on the maximum deformity surface, the direction of the rotation axis is perpendicular to the maximum deformity surface, and the position of the rotation axis is determined by the position of the extreme points.

8. The method for 3D preoperative intelligent osteotomy and correction of lower limbs according to claim 1, characterized in that: In S7, the expected joint center point includes the femoral head center point of the correct mechanical axis of the lower limb and the ankle joint center point of the correct mechanical axis of the lower limb; The method for calculating the correction angle comprises: Femoral deformity Automatically select a point on the extension line of the tibia mechanical axis that is equal to the femoral mechanical axis as the center point of the femoral head of the correct mechanical axis of the lower limb; Calculate the angle between the rotation axis and the center point of the femoral head on the correct mechanical axis of the lower limb to automatically calculate the correction angle of the distal deformed bone block; Tibial deformity Automatically select a point on the extension line of the femoral mechanical axis that is equal to the tibial mechanical axis as the center point of the ankle joint of the correct mechanical axis of the lower limb; The angle between the rotation axis and the center point of the ankle joint on the correct mechanical axis of the lower limb is calculated to automatically calculate the correction angle of the distal deformed bone block.

9. A lower limb 3D preoperative intelligent osteotomy and correction system, characterized in that: Implementing the lower limb 3D preoperative intelligent osteotomy correction method as claimed in any one of claims 1 to 8, and: A feature point acquisition module is used to acquire the spatial position information of manually selected joint center points, joint line constituent points, two backbone midpoints of the proximal backbone midline, and two backbone midpoints of the distal backbone midline; Mechanical axis building module, used to build the correct mechanical axis of the lower limbs and the mechanical axis of the lower limb deformity; The joint line construction module is used to construct the femoral head horizontal line, the distal femoral joint line, the proximal tibial joint line and the distal tibial joint line; A measurement module, used to measure the total lower limb length, femur length, tibia length, joint running direction angle and mechanical axis deviation value of the deformed bone before and after correction; An anatomical axis building module, used to build a proximal anatomical axis and a distal anatomical axis; A cutting surface positioning module, used for locating the cutting surface position; An osteotomy module, used for osteotomizing deformed bones at the cutting surface position; A rotation axis determination module is used to set the rotation axis at the extreme point of the cutting surface; A correction angle determination module is used to determine the angle that needs to be corrected for the distal deformed bone block; An automatic correction module is used to automatically correct the distal deformed bone block to the expected set position; The manual adjustment module is used to manually fine-tune the position of the distal deformed bone block.

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