Three-dimensional reconstruction method for femoral neck fracture bone defect area

Abstract

The invention provides a three-dimensional reconstruction method for a femoral neck fracture bone defect area, which belongs to the technical field of medical imaging and comprises the following steps: 1, morphologically reconstructing the pelvis, femur, femoral head and femoral shaft of a patient; 2, selecting a plurality of point locations of the reconstructed pelvic bone, determining an optimal mirror image, and performing mirror image uninjured side; 3, based on the uninjured side femoral head mirror image file, generating an affected side femoral shaft reduction file and an affected side femoral head reduction file; 4, adopting a Boolean operation tool to obtain a bone defect area; 5, calculating the volume of the bone defect area, and outputting the space coordinates of the gravity center. Based on CT data of a patient, virtual reduction can be carried out on femoral neck fracture, three-dimensional reconstruction can be carried out on the form of bone defect existing at the broken end, data such as the relative position and the volume of the bone defect area and the broken end can be output, visual and quantifiable reference can be provided for preoperative operation planning, and accurate bone grafting of the bone defect area in the operation is assisted.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical imaging, and particularly relates to a three-dimensional reconstruction method for the bone defect area of femoral neck fractures. Background Art

[0002] Femoral neck fractures are often accompanied by bone defects at the fracture site. The location and volume of the bone defect directly affect the healing of the fracture, as well as the incidence of nonunion and femoral head necrosis. Moreover, bone defects in different locations will cause corresponding changes in the surface stress of the implant. In the existing internal fixation surgical planning, surgeons often lack a full understanding of parameters such as the three-dimensional shape, location, and defect volume of the bone defect area, resulting in failure to achieve good anatomical reduction in some patients during the operation, or failure to perform appropriate bone grafting.

[0003] Therefore, a method that can fully understand parameters such as the three-dimensional shape, location, and defect volume of the femoral neck bone defect area is needed. Summary of the Invention

[0004] The purpose of the present invention is to provide a three-dimensional reconstruction method for the bone defect area of femoral neck fractures, which is characterized by including the following steps:

[0005] Step 1: Perform morphological reconstruction on the patient's pelvis, femur, femoral head, and femoral shaft.

[0006] 1): Obtain the patient's CT imaging data and read the data using three-dimensional reconstruction software;

[0007] 2): (Taking Mimics as an example in this patent). Use the Bone Segmentation tool in Mimics with a threshold of 180 - 200 HU to preliminarily segment the pelvis, the healthy side femur, the affected side femoral head, and the affected side femoral shaft;

[0008] 3): Use the multiple slice edit tool and the cavity fill tool to perform image segmentation and filling along the outer contours of the affected side femoral head, the affected side femoral shaft, and the healthy side femur;

[0009] 4): Use the Calculate Part tool to three-dimensionally reconstruct the four bony structures of the pelvis, the healthy side femur, the affected side femoral head, and the affected side femoral shaft, and save them as STL format files respectively.

[0010] Step 2: Import the four generated STL files into the post-processing software 3-matic, select points such as the coccyx and pubic symphysis on the pelvis file to determine the best mirror image, and mirror the healthy side femur of the patient to the opposite side along this mirror plane, denoted as the healthy side femur mirror image file;

[0011] Step 3: Based on the mirror image file of the healthy-side femoral head, generate the reduction file of the affected-side femoral shaft and the reduction file of the affected-side femoral head.

[0012] 1): Use the automatic registration (Global Registration) tool based on the ICP algorithm. Take the mirror image file of the healthy-side femur as the source point cloud Q1 and the patient's femoral shaft file as the target point cloud P1. Register and reduce the affected-side femoral shaft to the mirror image file of the healthy-side femur, denoted as the reduction of the affected-side femoral shaft.

[0013] 2): Use the Lasso area mask tool to extract the fovea of the affected-side femoral head and the fovea of the femoral head on the surface of the mirror image of the healthy-side femur respectively, denoted as the fovea of the affected-side femoral head and the fovea of the mirror image of the healthy-side femoral head.

[0014] 3): Use the automatic registration tool based on the ICP algorithm. Take the fovea of the mirror image of the healthy-side femoral head as the source point cloud Q2 and the fovea of the affected-side femoral head as the target point cloud P2. Make the affected-side femoral head follow the fovea of the affected-side femoral head and register it to the fovea of the mirror image of the healthy-side femoral head, denoted as the reduction of the affected-side femoral head.

[0015] Step 4: Use the Boolean operations tool to perform a Boolean addition operation on the reduced affected-side femoral shaft and the affected-side femoral head to form a whole, denoted as the affected-side reduction file. Use the mirror image file of the healthy-side femur to perform a Boolean subtraction operation on the affected-side reduction file to obtain the bone defect area.

[0016] S5: Fit the center of gravity and output the volume V of the bone defect area and the center coordinates G of the bone defect area.

[0017] Among them, the volume calculation formula of the bone defect area is expressed as:

[0018] V 骨缺损区域 = V 健侧股骨镜像 -(V 患侧股骨干复位 + V 患侧股骨头复位

[0019] The spatial coordinates G of the center of gravity are expressed as (X1 + X2…+ X n \n, Y1 + Y2…+ Y n \n, Z1 + Z2…+ Z n \n).

[0020] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in that: the method of the present invention can perform virtual reduction on femoral neck fractures based on the patient's CT data, three-dimensionally reconstruct the shape of the bone defect existing at the fracture ends, and can output data such as the relative position and volume of the bone defect area and the fracture ends, providing a visual and quantifiable reference for preoperative surgical planning and assisting in precise bone grafting in the bone defect area during the operation. Brief Description of the Drawings

[0021] Figure 1 This is a schematic flow diagram of a three-dimensional reconstruction method for the bone defect area of femoral neck fractures in the present invention.

[0022] Figure 2 This is a schematic diagram after three-dimensional reconstruction of the four bony structures of the pelvis, the healthy-side femur, the affected-side femoral head, and the affected-side femoral shaft in the present invention.

[0023] Figure 3 This is a schematic diagram of the mirror image file of the healthy-side femur in the present invention.

[0024] Figure 4 This is a comparison diagram before and after reduction of the affected-side femoral head and the affected-side femoral shaft in the present invention.

[0025] Figure 5 This is a schematic diagram of the bone defect area in the present invention.

[0026] Figure 6 This is a schematic diagram of the three-dimensional shape of the bone defect area in the present invention. Detailed implementation method

[0027] The following will describe in more detail a three-dimensional reconstruction method for the bone defect area of femoral neck fractures in the present invention with reference to the schematic diagrams, in which the preferred embodiments of the present invention are shown. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as a broad guidance for those skilled in the art and not as a limitation on the present invention.

[0028] As Figure 1 shown, a three-dimensional reconstruction method for the bone defect area of femoral neck fractures includes the following steps:

[0029] Step 1

[0030] Obtain the patient's CT imaging data and read the data using three-dimensional reconstruction software (this patent takes Mimics as an example). Use the Bone Segmentation tool in Mimics with a threshold of 180 - 200 HU to preliminarily segment the pelvis, the healthy-side femur, the affected-side femoral head, and the affected-side femoral shaft. Use the multiple slice edit tool and the cavityfill tool to further segment and fill the images along the outer contours of the affected-side femoral head, the affected-side femoral shaft, and the healthy-side femur.

[0031] Continue to use the Calculate Part tool to three-dimensionally reconstruct the four bony structures of the pelvis, the healthy-side femur, the affected-side femoral head, and the affected-side femoral shaft, and save them in STL format, as Figure 2 shown.

[0032] Step 2

[0033] Import the four generated STL files into the post-processing software 3-matic. Select points such as the coccyx and symphysis pubis on the pelvic file to determine the optimal mirror plane. Along this mirror plane, mirror the healthy-side femur of the patient to the opposite side, denoted as the "mirrored healthy-side femur" file, as Figure 3 shown.

[0034] Step Three

[0035] Use the automatic registration (Global Registration) tool based on the ICP algorithm. Take the "mirrored healthy-side femur" file as the source point cloud Q1 and the patient's femoral shaft file as the target point cloud P1, and register and reset the affected-side femoral shaft to the "mirrored healthy-side femur" file, denoted as "reset of the affected-side femoral shaft".

[0036] Use the Lasso area mask tool to extract the fovea capitis femoris regions on the surface of the affected-side femoral head and the mirrored healthy-side femur respectively, denoted as the fovea capitis femoris of the affected side and the fovea capitis femoris of the mirrored healthy side.

[0037] Continue to use the automatic registration (Global Registration) tool based on the ICP algorithm. Take the fovea capitis femoris of the mirrored healthy side as the source point cloud Q2 and the fovea capitis femoris of the affected side as the target point cloud P2, so that the "affected-side femoral head" follows the "fovea capitis femoris of the affected side" and registers to the "fovea capitis femoris of the mirrored healthy side", and is denoted as "reset of the affected-side femoral head", as Figure 4 shown.

[0038] Step Four

[0039] Use the Boolean operations tool to perform a Boolean addition operation on the virtually reset affected-side femoral shaft and the affected-side femoral head to form a whole, denoted as "reset of the affected side". Boolean subtract the "reset of the affected side" file from the "mirrored healthy-side femur" to obtain the bone defect area. As Figure 5 shown.

[0040] Step Five

[0041] As Figure 6 shown, it is a schematic diagram of the three-dimensional shape of the bone defect area. This patent outputs the volume V (unit: mm3) of the bone defect area and the spatial coordinates G of the centroid of the bone defect area.

[0042] Among them, the formula for the volume of the bone defect area is:[[]]

[0043] V 骨缺损区域 = V 健侧股骨镜像 -(V 患侧股骨干复位 + V 患侧股骨头复位

[0044] The spatial coordinates G of the center of gravity are expressed as (X1 + X2… + X n \n, Y1 + Y2… + Y n \n, Z1 + Z2… + Z n \n).

[0045] The location and volume of bone defects directly affect the healing of fractures, as well as the incidence of nonunion and femoral head necrosis. Moreover, bone defects in different locations will cause corresponding changes in the surface stress of implants. Through the method of the present invention, the area of the bone defect region can be reconstructed and calculated, and data such as the relative position and volume of the bone defect region and the fracture ends can be calculated, providing a visual and quantifiable reference for preoperative surgical planning, assisting in accurate bone grafting in the bone defect region during the operation, thereby reducing the healing cycle of patients and further reducing the medical cost.

[0046] The above are only the preferred embodiments of the present invention and do not impose any limitation on the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification and other changes to the technical solution and technical content disclosed by the present invention, all of which fall within the content of the technical solution of the present invention and still belong to the protection scope of the present invention.

Claims

1. A three-dimensional reconstruction method for the bone defect area of femoral neck fractures, characterized in that It includes the following steps: S1: Perform morphological reconstruction on the patient's pelvis, femur, femoral head, and femoral shaft; S2: Based on the pelvis file in the morphological reconstruction file, select multiple pelvis points, determine the optimal mirror image, and along this mirror plane, mirror the healthy-side femur of the patient to the contralateral side, denoted as the healthy-side femur mirror image file; S3: Based on the healthy-side femoral head mirror image file, generate the diseased-side femoral shaft reduction file and the diseased-side femoral head reduction file; S4: Use a Boolean operation tool to perform a Boolean addition operation on the reduced diseased-side femoral shaft and diseased-side femoral head to form a whole, denoted as the diseased-side reduction file, and use the healthy-side femur mirror image file to perform a Boolean subtraction operation on the diseased-side reduction file to obtain the bone defect area; S5: Fit the center of gravity and output the volume of the bone defect area and the spatial coordinates of the center of gravity of the bone defect area.

2. The three-dimensional reconstruction method for the bone defect area of femoral neck fracture according to claim 1, characterized in that, The specific steps of S1 include the following: S11: Obtain the patient's CT imaging data and read the data using 3D reconstruction software; S12: Use a segmentation tool to preliminarily segment the pelvis, healthy-side femur, diseased-side femoral head, and diseased-side femoral shaft; S13: Use a multi-layer editing tool and a cavity filling tool to perform image segmentation and filling along the outer contours of the diseased-side femoral head, diseased-side femoral shaft, and healthy-side femur; S14: Use a create solid tool to perform 3D reconstruction on the four bony structures of the pelvis, healthy-side femur, diseased-side femoral head, and diseased-side femoral shaft, and save them as files respectively.

3. The three-dimensional reconstruction method for the bone defect area of femoral neck fractures according to claim 2, characterized in that S2 is completed by importing the 4 components generated in S14 into post-processing software.

4. The three-dimensional reconstruction method for the bone defect area of femoral neck fracture according to claim 1, wherein The specific steps of S3 include the following: S31: Use an automatic registration tool based on the ICP algorithm. Taking the healthy-side femur mirror image file as the source point cloud Q1 and the patient's femoral shaft file as the target point cloud P1, register and reduce the diseased-side femoral shaft to the healthy-side femur mirror image file, denoted as the diseased-side femoral shaft reduction; S32: Use a lasso tool to extract the femoral head concave areas on the surfaces of the diseased-side femoral head and the healthy-side femur mirror image respectively, denoted as the diseased-side femoral head concave and the healthy-side mirror femoral head concave; S33: Use an automatic registration tool based on the ICP algorithm. Taking the healthy-side mirror femoral head concave as the source point cloud Q2 and the diseased-side femoral head concave as the target point cloud P2, make the diseased-side femoral head follow the diseased-side femoral head concave and register it to the healthy-side mirror femoral head concave, denoted as the diseased-side femoral head reduction.

5. The three-dimensional reconstruction method for the bone defect area of femoral neck fractures according to claim 1, wherein In S5, the volume calculation formula of the bone defect area is expressed as: V 骨缺损区域 = V 健侧股骨镜像 - (V 患侧股骨干复位 + V 患侧股骨头复位 ) The spatial coordinates of the center of gravity are expressed as (X1 + X2… + X n \n, Y1 + Y2… + Y n \n, Z1 + Z2… + Z n \n).

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