CN115153834A - Intelligent osteotomy correction method and system for lower limb 3D preoperative operation - Google Patents

Abstract

The invention provides a method and a system for intelligently cutting bones and correcting a lower limb before a 3D operation, which comprises the following steps: the device comprises a characteristic 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. According to the invention, three-dimensional accurate measurement can be realized through the measurement module; the positioning precision in the operation process can be improved through the cutting surface positioning module, and the operation success rate and safety are improved; through simulating osteotomy, automatic correction and manual adjustment modules, an operation prediction model of the coronal plane valgus deformity and the coronal plane angulation deformity of the lower limb can be established.

Description

Intelligent lower limb 3D preoperative osteotomy orthopedic method and system

Technical Field

The invention relates to the technical field of intelligent diagnosis and treatment, in particular to an intelligent lower limb 3D preoperative osteotomy correction method and system.

Background

The lower limbs are mainly used for loading and walking, so that the balance of the length of the lower limbs and the restoration of the normal axis of the lower limbs are particularly important in the treatment of various bone joint deformities or fractures. At present, for lower limb long bone deformity such as coronal plane eversion and coronal plane angulation, osteotomy correction is a common treatment method clinically. The key of the treatment effect of the lower limb orthopedic surgery lies in designing a perfect surgical scheme and accurately controlling the osteotomy part, the osteotomy angle and the osteotomy amount. However, the traditional osteotomy orthopedic surgery is difficult to do orthopedic surgery in a three-dimensional space, has obvious defects in the aspect of accuracy, and can not simulate the postoperative tissue morphology before the operation.

Through the analysis of the complaints, the problems and the defects existing in the prior art are as follows: the two-dimensional plane measurement method is not comprehensive and accurate enough, the postoperative correction result cannot be predicted, and the design time of the operation scheme is long.

Disclosure of Invention

The invention aims to provide a method and a system for intelligently cutting bones and correcting the lower limb before a 3D operation, aiming at the defects of the prior art, and the method and the system can realize three-dimensional accurate measurement and correction.

In order to realize the purpose, the invention adopts the following technical scheme:

the invention provides an intelligent lower limb 3D preoperative osteotomy orthopedic method, which comprises the following steps:

s1, leading an STL model of healthy bones and deformed bones generated by CT data into a lower limb 3D preoperative intelligent osteotomy orthopedic system;

s2, acquiring spatial position information of a joint central point of the manually selected model through a characteristic point acquisition module, and constructing a mechanical shaft by utilizing the acquired spatial position information of the joint central point through a mechanical shaft construction modeling module;

s3, collecting the spatial position information of joint line forming points of the manually selected model through the characteristic point collecting module, and constructing joint lines by utilizing the collected spatial position information of the joint line forming points through the joint line constructing module;

s4, automatically calculating the bone length, the joint walking direction angle and the mechanical axis deviation value formed between the joint line of the deformed bone model before correction and the deformed mechanical axis through a measuring module;

s5, acquiring the spatial position information of two diaphysial midpoints of a proximal diaphysial midline and two diaphysial midpoints of a distal diaphysial midline of the malformed bone model manually through a characteristic point acquisition module, and constructing a proximal anatomic shaft and a distal anatomic shaft on the malformed bone model by utilizing the acquired spatial position information of the two diaphysial midpoints of the proximal diaphysial midline and the two diaphysial midpoints of the distal diaphysial midline through an anatomic shaft construction modeling block;

s6, a cutting surface is arranged at an angular bisector of an intersection point formed by the proximal dissection axis and the distal dissection axis through a cutting surface positioning module; cutting bones at a cutting surface through a bone cutting module to generate a proximal malformed bone block and a distal malformed bone block;

s7, a rotating shaft is determined through a rotating shaft determining module according to two extreme points of the cutting surface contour line on the maximum abnormal surface, a correction angle is calculated through a correction angle determining module according to an included angle between the rotating shaft and the center point of the expected joint, and the position of the abnormal bone block is adjusted through an automatic correction module according to the correction angle, so that the adjusted abnormal bone block is in a preset standard position;

and S8, automatically calculating the bone length, the joint running direction angle and the mechanical axis deviation value of the deformed bone model after automatic correction through the measuring module, manually finely adjusting the angle according to the joint running direction angle of the deformed bone after correction through the manual adjusting module, providing real-time data of the corrected angle by the system in the adjusting process, and generating a final correcting scheme.

Further, in S2, the joint center point includes a femoral head center point, a knee joint center point, and an ankle joint center point;

the mechanical shaft comprises a lower limb correct mechanical shaft, a full lower limb mechanical shaft, a femur mechanical shaft and a tibia mechanical shaft, and is specifically constructed as follows:

s101, automatically constructing a straight line from the center of the femoral head to the center of the ankle joint as a full lower limb mechanical axis;

automatically constructing a straight line from the center of the femoral head to the center of the knee joint as a femoral mechanical shaft;

automatically constructing a straight line from the knee joint center to the bare joint center as a tibia mechanical axis;

s102, automatically constructing a mechanical tibial axis extension line as a correct lower limb mechanical axis after femoral deformity;

s103, automatically constructing a mechanical axis extension line of the femur as a correct mechanical axis of the lower limb when the tibia is deformed;

further, in S3, the joint line forming points include a femur medial condyle lowest point, a femur lateral condyle lowest point, a tibia plateau plane medial point, a tibia plateau plane lateral point, a tibia distal subchondral bone line medial end point, and a tibia distal subchondral bone line lateral end point;

the joint line comprises a proximal femur joint line, a distal femur joint line, a proximal tibia joint line and a distal tibia joint line, and is specifically constructed as follows:

automatically constructing a femoral head horizontal line as a proximal femur joint line;

automatically constructing a connecting line between the lowest points of the inner and outer condyles of the femur as a distal femur joint line;

automatically constructing a connecting line of inner and outer side points of a tibial plateau plane as a proximal tibial joint line;

and automatically constructing a connecting line of the inner and outer side end points of the tibial subchondral bone line as a tibial distal joint line.

Further, in S4, the bone length includes a full lower limb length, a femur length, and a tibia length;

the joint walking direction angle comprises:

a mechanical external angle of the proximal femur & lt mlPFA,

A mechanical external angle of the distal femur mLDFA,

A mechanical internal side angle of tibia near end mMPTA,

Mechanical outer side angle mLDTA of tibia far end

And a knee joint wire clip angle < JLCA.

The length of the bone is as follows:

calculating the length of the whole lower limb according to the linear distance from the center of the femoral head to the center of the ankle joint,

Automatically calculating the length of the femur through the linear distance from the center of the femoral head to the center of the knee joint,

Automatically calculating the length of the tibia through the linear distance from the knee joint center to the ankle joint center;

mechanical axis offset value:

and automatically calculating the mechanical axis deviation value according to the vertical distance between the knee joint center and the mechanical axis of the whole lower limb.

Further, in the step 5, the proximal dissection axis is a connection line of two diaphysis midpoints on a proximal diaphysis midline, and the distal dissection axis is a connection line of two diaphysis midpoints on a distal diaphysis midline.

Further, in S7, the maximum deformity shape surface is formed by a femoral head central point, a knee joint central point, and an ankle joint central point;

the malformed bone pieces comprise distal and proximal malformed bone pieces, wherein,

the femur deformity is divided into a proximal femur malformed bone block and a distal femur malformed bone block after osteotomy, and the position of the proximal femur malformed bone block needs to be adjusted;

and (3) tibial deformity, namely dividing the tibial deformity bone block into a proximal tibial malformation bone block and a distal tibial malformation bone block after osteotomy, wherein the position of the distal tibial malformation bone block needs to be adjusted.

Further, in S7, the method for determining the rotation axis includes:

s701, projecting all points on the contour line of the cutting surface to the maximum distortion surface;

s702, finding two extreme points along the X-axis direction on the maximum distortion surface, wherein the rotation axis direction is vertical to the maximum distortion surface, and the position of the rotation axis is determined by the positions of the extreme points.

Further, in S7, the expected joint center point includes a femoral head center point of a correct mechanical axis of the lower limb and an ankle joint center point of the correct mechanical axis of the lower limb;

the method for calculating the correction angle comprises the following steps:

deformity of femur

Automatically selecting a point with the same length as the mechanical axis of the femur on the extension line of the mechanical axis of the tibia as the center point of the femoral head of the correct mechanical axis of the lower limb;

calculating an angle between the rotating shaft and the femoral head central point on the lower limb correct mechanical shaft, and automatically calculating the correction angle of the distal end malformed bone block;

tibial deformity

Automatically selecting a point with the same length as the mechanical axis of the tibia on the extension line of the mechanical axis of the femur as the ankle joint central point of the correct mechanical axis of the lower limb;

and calculating an angle between the rotating shaft and the central point of the ankle joint on the correct mechanical axis of the lower limb, and automatically calculating the correction angle of the distal malformed bone block.

The invention also provides an intelligent lower limb 3D preoperative osteotomy orthopedic system, which realizes an intelligent lower limb 3D preoperative osteotomy orthopedic method and comprises the following steps:

the characteristic point acquisition module is used for acquiring the manually selected joint central points, joint line forming points, two backbone middle points of a proximal backbone middle line and two backbone middle points of a distal backbone middle line;

the mechanical shaft construction module is used for constructing a correct mechanical shaft of the lower limb and a deformed mechanical shaft of the lower limb;

the joint line construction module is used for constructing a femoral head horizontal line, a femoral distal joint line, a tibial proximal joint line and a tibial distal joint line;

the measurement module is used for measuring the length of the deformed bone whole lower limb, the length of the femur, the length of the tibia, the joint walking direction angle and the mechanical axis deviation value before and after correction;

an anatomical shaft construction module for constructing a proximal anatomical shaft and a distal anatomical shaft;

the cutting surface positioning module is used for positioning the position of a cutting surface;

the bone cutting module is used for cutting the deformed bone at the position of the cutting surface;

the rotating shaft determining module is used for setting a rotating shaft at an extreme point of a cutting surface;

the correcting angle determining module is used for determining the angle of the far-end malformed bone block to be corrected;

the automatic correction module is used for automatically correcting the distal malformed bone block to adjust to an expected set position;

and the manual adjusting module is used for manually finely adjusting the position of the distal malformed bone block.

The invention has the beneficial effects that: the measurement and the correction of the lower limb mechanical axis are not limited to a two-dimensional plane, and three-dimensional accurate measurement and correction can be realized;

the cutting surface positioning module can improve the positioning precision in the operation process and increase the success rate and safety of the operation;

the simulation osteotomy, the automatic correction and the manual adjustment module are combined with the operation, so that an operation prediction model of the varus deformity in the coronal plane of the lower limb and the angulation deformity in the coronal plane of the lower limb can be established, and scientific basis is provided for the subsequent operation;

the operation process is relatively programmed. It is convenient for guiding more young doctors with less experience to master some complicated and difficult operations.

Drawings

Fig. 1 is a flowchart of an intelligent lower limb 3D osteotomy orthopedic method according to an embodiment of the present invention.

FIG. 2 is a diagram of a model of a deformed and healthy bone of a patient before correction according to the first embodiment.

FIG. 3 is a schematic view of the patient's lower limb correct mechanical axis, full lower limb mechanical axis, femoral mechanical axis and tibial mechanical axis according to the first embodiment.

FIG. 4 is a schematic view of a proximal femur joint line, a distal femur joint line, a proximal tibia joint line and a distal tibia joint line of a patient according to an embodiment.

FIG. 5 is a proximal femoral anatomical axis and a distal femoral anatomical axis of a patient according to one embodiment.

FIG. 6 is a schematic view of the positioning position of the cutting plane in the first embodiment.

FIG. 7 is a schematic cut-away plan view of an embodiment.

FIG. 8 is a schematic diagram illustrating the determination of the rotation axis according to the first embodiment.

Fig. 9 is a schematic view of the simulated surgical reduction after automatic correction according to the first embodiment.

Fig. 10 is a diagram of a model of a deformed and healthy bone of a patient before correction according to example two.

Fig. 11 is a schematic diagram of the simulated surgical reduction after the automatic correction according to the second embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example one

An intelligent lower limb 3D preoperative osteotomy orthopedic method is shown in fig. 1, and comprises the following steps:

s1, importing an STL model of healthy bones and deformed bones generated by CT data into a lower limb 3D preoperative intelligent osteotomy orthopedic system. In this embodiment, a healthy tibia STL model and a malformed femur STL model of the patient are introduced, as shown in fig. 2.

S2, acquiring spatial position information of a joint central point of the manually selected model through a characteristic point acquisition module; and constructing a mechanical shaft by using the collected spatial position information of the joint central point through a mechanical shaft structure modeling block. In this embodiment, a mechanical axis is automatically constructed for the manually selected spatial position information of the joint center point, as shown in fig. 3, axis 1 is a full lower limb mechanical axis, axis 2 is a femur mechanical axis, axis 3 is a tibia mechanical axis, and axis 4 is a lower limb correct mechanical axis.

S3, collecting the spatial position information of joint line forming points of the manually selected model through a characteristic point collecting module; and constructing the joint line by using the collected space position information of the joint line construction points through a joint line construction module. In this embodiment, the joint line is automatically constructed based on the spatial position information of the joint line constituent points manually selected, as shown in fig. 4, the joint line 5 is a proximal femur joint line, the joint line 6 is a distal femur joint line, the joint line 7 is a proximal tibia joint line, and the joint line 8 is a distal tibia joint line.

And S4, automatically calculating a joint walking direction angle, a bone length and a mechanical axis deviation value formed between a joint line of the deformed bone model before correction and the deformed mechanical axis through the measuring module. In this embodiment, the walking direction angle of the joint before correction, the bone length, and the mechanical axis offset value are automatically calculated. The joint walking direction angle before correction is 73.0 degrees, the angle LDFA is 106.4 degrees, the angle JLCA is 0.5 degrees, the angle mMPTA is 87.7 degrees, and the angle mLDTA is 90.0 degrees. Of the automatically calculated bone lengths, the total lower limb length was 694.6 mm, the femur length was 376.5 mm, and the tibia length was 328.0 mm. The automatically calculated mechanical axis offset value was 58.5 mm.

S5, acquiring the spatial position information of two diaphysis midpoints of a proximal diaphysis midline and two diaphysis midpoints of a distal diaphysis midline of the manually selected malformed bone model through a characteristic point acquisition module; and constructing a proximal anatomical shaft and a distal anatomical shaft on the malformed bone model by using the acquired spatial position information of the two diaphyseal midpoints of the proximal diaphyseal midline and the two diaphyseal midpoints of the distal diaphyseal midline through an anatomical shaft structure modeling block. In this embodiment, as shown in fig. 5, the shaft 9 is a proximal femoral anatomical shaft and the shaft 10 is a distal femoral anatomical shaft.

S6, a cutting surface is arranged at an angular bisector of an intersection point formed by the proximal dissection axis and the distal dissection axis through the cutting surface positioning module; and (3) cutting the bone at the cutting surface through the bone cutting module to generate a proximal malformed bone block and a distal malformed bone block. In this embodiment, the cutting plane is located at the bisector of the intersection formed by the proximal femoral anatomical axis and the distal femoral anatomical axis, as shown in fig. 6. As shown in fig. 7, a schematic cut surface.

S7, determining a rotating shaft according to two extreme points of the cutting surface contour line on the maximum distortion surface through a rotating shaft determining module; the correction angle determining module calculates a correction angle according to an included angle between the rotating shaft and the center of the expected joint; 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 preset standard position. In the present embodiment, as shown in fig. 8, the shaft 11 is a rotation shaft. As shown in fig. 9, after the osteotomy, the proximal femur malformed bone piece and the distal femur malformed bone piece are separated, and the position of the proximal femur malformed bone piece is adjusted.

S8, automatically calculating a joint walking direction angle, a bone length and a mechanical axis deviation value of the deformed bone model after automatic correction through a measuring module; the angle is manually finely adjusted by a manual adjustment module according to the joint running direction angle of the corrected deformed bone, the system provides real-time data of the correction angle in the adjustment process, and a final correction scheme is generated. In the embodiment, the joint running direction angle of the corrected model is 91.6 degrees, the angle LDFA is 87.8 degrees, the angle JLCA is 0.5 degrees, the angle mMPTA is 87.7 degrees and the angle mLDTA is 90.0 degrees. Of the automatically calculated bone lengths, the total lower limb length was 716.0 mm, the femur length was 388.0 mm, and the tibia length was 328.0 mm. The automatically calculated mechanical axis offset value is 1.9 mm. Fig. 9 is a schematic view of simulated surgical reduction after automatic correction.

Example 2 two

Angulation deformity of tibia

The other characteristics of the intelligent osteotomy orthopedic method before the 3D operation of the lower limb are the same as those of the embodiment 1, and the difference is that:

and (S2) constructing a mechanical axis, wherein the accurate lower limb mechanical axis is a femur mechanical axis extension line.

Step S5, constructing an anatomical shaft, specifically constructing a proximal tibial anatomical shaft and a distal tibial anatomical shaft;

step S6, a cutting surface is set, and the specific cutting surface is positioned at an angular bisector of an intersection point formed by the proximal tibia dissection axis and the distal tibia dissection axis;

in step S7, the correction angle is calculated according to the angle between the rotation axis and the center of the expected joint, wherein the center of the expected joint 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, the bone is divided into a proximal tibia deformed bone block and a distal tibia deformed bone block after osteotomy, and the position of the distal tibia deformed bone block is specifically adjusted.

The above-mentioned embodiments only express the embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent should be defined by the appended claims.

Claims (9)

1. An intelligent lower limb 3D preoperative osteotomy orthopedic method is characterized by comprising the following steps:

s1, leading an STL model of healthy bones and deformed bones generated by CT data into a lower limb 3D preoperative intelligent osteotomy orthopedic system;

s2, acquiring spatial position information of a joint central point of the manually selected model through a characteristic point acquisition module, and constructing a mechanical shaft by utilizing the acquired spatial position information of the joint central point through a mechanical shaft construction modeling module;

s3, collecting the spatial position information of joint line forming points of the manually selected model through the characteristic point collecting module, and constructing joint lines by utilizing the collected spatial position information of the joint line forming points through the joint line constructing module;

s4, automatically calculating the bone length, the joint walking direction angle and the mechanical axis deviation value formed between the joint line of the deformed bone model before correction and the deformed mechanical axis through a measuring module;

s5, acquiring the spatial position information of two backbone midpoints of a proximal backbone midline and two backbone midpoints of a distal backbone midline of the malformed bone model manually through a characteristic point acquisition module, and constructing a proximal anatomical shaft and a distal anatomical shaft on the malformed bone model by utilizing the acquired spatial position information of the two backbone midpoints of the proximal backbone midline and the two backbone midpoints of the distal backbone midline through an anatomical shaft construction modeling block;

s6, a cutting surface is arranged at an angular bisector of an intersection point formed by the proximal dissection axis and the distal dissection axis through a cutting surface positioning module; cutting bones at a cutting surface through a bone cutting module to generate a proximal malformed bone block and a distal malformed bone block;

s7, a rotating shaft is determined through a rotating shaft determining module according to two extreme points of the cutting surface contour line on the maximum deformed surface, a correction angle is calculated through a correction angle determining module according to an included angle between the rotating shaft and the center point of the expected joint, and the position of the deformed bone block is adjusted through an automatic correction module according to the correction angle, so that the adjusted deformed bone block is in a preset standard position;

and S8, automatically calculating the bone length, the joint walking direction angle and the mechanical axis deviation value of the deformed bone model after automatic correction through the measuring module, manually finely adjusting the angle according to the joint walking direction angle of the deformed bone after correction through the manual adjusting module, providing real-time data of the corrected angle by the system in the adjusting process, and generating a final correcting scheme.

2. The method for intelligently osteotomy and orthopedic surgery on lower limb 3D of claim 1, wherein: in S2, the joint central points comprise a femoral head central point, a knee joint central point and an ankle joint central point;

the mechanical shaft comprises a lower limb correct mechanical shaft, a full lower limb mechanical shaft, a femur mechanical shaft and a tibia mechanical shaft, and is specifically constructed as follows:

s101, automatically constructing a straight line from the center of the femoral head to the center of the ankle joint as a full lower limb mechanical axis;

automatically constructing a straight line from the center of the femoral head to the center of the knee joint as a femoral mechanical shaft;

automatically constructing a straight line from the knee joint center to the bare joint center as a tibia mechanical axis;

s102, automatically constructing a mechanical tibial shaft extension line as a correct lower limb mechanical shaft after femoral deformity;

s103, tibial deformity, and automatically constructing a mechanical axis extension line of the femur as a correct mechanical axis of the lower limb.

3. The method for intelligently osteotomy and orthopedic surgery on lower limb 3D of claim 1, wherein: s3, the joint line forming points comprise a femur medial condyle lowest point, a femur lateral condyle lowest point, a tibia plateau plane medial point, a tibia plateau plane lateral point, a tibia far-end subchondral bone line medial end point and a tibia far-end subchondral bone line lateral end point;

the joint line comprises a proximal femur joint line, a distal femur joint line, a proximal tibia joint line and a distal tibia joint line, and is specifically constructed as follows:

automatically constructing a femoral head horizontal line as a proximal femur joint line;

automatically constructing a connecting line between the lowest points of the inner and outer condyles of the femur as a distal femur joint line;

automatically constructing a connecting line of inner and outer side points of a tibial plateau plane as a proximal tibial joint line;

and automatically constructing a connecting line of the inner and outer side end points of the tibial subchondral bone line as a tibial distal joint line.

4. The method of intelligently osteotomy orthopedic before lower limb 3D surgery of claim 1, wherein, S4, bone length includes full lower limb length, femur length, and tibia length;

the joint walking direction angle comprises:

the mechanical external angle of the proximal femur is mLPFA,

A mechanical external angle of the distal femur mLDFA,

A mechanical internal side angle of tibia near end mMPTA,

Mechanical outer side angle mLDTA of tibia far end

And the clip angle of the knee joint is JLCA.

The length of the bone is as follows:

the length of the whole lower limb is calculated by the linear distance from the center of the femoral head to the center of the ankle joint,

Automatically calculating the length of the femur through the linear distance from the center of the femoral head to the center of the knee joint,

Automatically calculating the length of the tibia through the linear distance from the knee joint center to the ankle joint center;

mechanical axis offset value:

and automatically calculating the deviation value of the mechanical axis according to the vertical distance between the knee joint center and the mechanical axis of the whole lower limb.

5. The method of claim 1, wherein in the step 5, the proximal anatomical axis is a connection line between two diaphyseal midpoints on a proximal diaphyseal midline, and the distal anatomical axis is a connection line between two diaphyseal midpoints on a distal diaphyseal midline.

6. The method of claim 1, wherein in step S7, the maximum deformity shape surface is formed by a femoral head center point, a knee joint center point and an ankle joint center point;

the malformed bone pieces comprise distal and proximal malformed bone pieces, wherein,

the femur deformity comprises a proximal femur malformed bone block and a distal femur malformed bone block after osteotomy, wherein the position of the proximal femur malformed bone block needs to be adjusted;

and (3) tibial deformity, namely dividing the tibial deformity bone block into a proximal tibial malformation bone block and a distal tibial malformation bone block after osteotomy, wherein the position of the distal tibial malformation bone block needs to be adjusted.

7. The method for intelligent osteotomy correction before 3D lower limb operation according to claim 1, wherein in S7, the method for determining the rotation axis comprises:

s701, projecting all points on the contour line of the cutting surface to the maximum distortion surface;

s702, finding two extreme points along the X-axis direction on the maximum distortion surface, wherein the rotation axis direction is vertical to the maximum distortion surface, and the rotation axis position is determined by the extreme point position.

8. The method for intelligently osteotomy orthopedic before lower limb 3D surgery according to claim 1, characterized in that: in S7, the expected joint center point includes a femoral head center point of a lower limb correct mechanical axis and an ankle joint center point of a lower limb correct mechanical axis;

the method for calculating the correction angle comprises the following steps:

deformity of femur

Automatically selecting a point with the same length as the mechanical axis of the femur on the extension line of the mechanical axis of the tibia as the center point of the femoral head of the correct mechanical axis of the lower limb;

calculating an angle formed between the rotating shaft and the central point of the femoral head on the correct mechanical shaft of the lower limb, and automatically calculating the correction angle of the far-end malformed bone block;

deformity of tibia

Automatically selecting a point with the same length as the mechanical axis of the tibia on the extension line of the mechanical axis of the femur as the ankle joint central point of the correct mechanical axis of the lower limb;

and calculating an angle between the rotating shaft and the central point of the ankle joint on the correct mechanical axis of the lower limb, and automatically calculating the correction angle of the distal malformed bone block.

9. An intelligent lower limb 3D preoperative osteotomy correction system, characterized by realizing the intelligent lower limb 3D preoperative osteotomy correction method according to any one of claims 1 to 8, and:

the characteristic point acquisition module is used for acquiring the manually selected joint center points, joint line forming points, two backbone middle points of a proximal backbone middle line and two backbone middle points of a distal backbone middle line;

the mechanical shaft construction module is used for constructing a correct mechanical shaft of the lower limb and a malformed mechanical shaft of the lower limb;

the joint line construction module is used for constructing a femoral head horizontal line, a femoral far-end joint line, a tibial near-end joint line and a tibial far-end joint line;

the measurement module is used for measuring the length of the deformed bone whole lower limb, the length of the femur, the length of the tibia, the joint walking direction angle and the mechanical axis deviation value before and after correction;

an dissecting shaft construction module for constructing a proximal dissecting shaft and a distal dissecting shaft;

the cutting surface positioning module is used for positioning the position of a cutting surface;

the bone cutting module is used for cutting the deformed bone at the position of the cutting surface;

the rotating shaft determining module is used for setting a rotating shaft at an extreme point of a cutting surface;

the correcting angle determining module is used for determining the angle of the far-end malformed bone block to be corrected;

the automatic correction module is used for automatically correcting the far-end malformed bone block and adjusting the far-end malformed bone block to an expected set position;

and the manual adjusting module is used for manually finely adjusting the position of the distal malformed bone block.

Images