CN108175378A - A kind of determining method of knee joint central point - Google Patents

Abstract

The invention discloses a method for determining the center point of the knee joint. The bone model is reconstructed by CT scanning DICOM data, and the non-bone space of the knee joint after three-dimensional reconstruction is perfused by 3D modeling software, and the center point of the perfused body is taken as Center of the knee joint. In traditional knee replacement, the doctor determines the force line of the lower limb according to the preoperative scan of the two-dimensional X-ray of the patient's lower limb, including the determination of the midline point of the knee joint. The midpoint of the connecting line of the condyle, this method not only brings great subjective randomness, but also is difficult to complete accurate positioning, and belongs to two-dimensional definition and two-dimensional measurement. The present invention reconstructs the bone model through CT scanning DICOM data and determines it at a three-dimensional angle. The center point of the knee joint reduces human errors caused by traditional manual measurement and is determined in three-dimensional space with higher accuracy.

Description

A Method for Determining the Center Point of the Knee Joint

technical field

The invention relates to the field of medical technology, in particular to a method for determining the central point of a knee joint.

Background technique

In the field of medical technology, it is often necessary to understand the determination of geometric parameters such as limb position and angle deflection, and to study the biological characteristics of limbs by controlling certain geometric parameters. For example, in total knee arthroplasty (Total Knee Arthroplasty, TKA) surgery, osteotomy surgery and patellar dislocation surgery, in order to achieve good clinical long-term results, the selection of indications, the selection of prostheses, the precise mastery of surgical techniques and Pre-operative management is very important, especially the requirements for surgical skills to a large extent, not only accurate osteotomy in three-dimensional space, three-dimensional placement of prostheses, but also the re-replication of biomechanics after knee replacement. It has been reported in the literature that in addition to general complications such as infection and fat embolism, up to 50% of early revision operations are related to improper alignment, improper placement of prostheses, and joint instability. Therefore, in order to obtain better long-term follow-up results, anatomical reconstruction of the lower limb biological force line and the axis of rotation of the prosthesis is the ultimate goal that people continue to explore and pursue.

In traditional total knee replacement surgery, preoperative X-ray examinations and intraoperative mechanical guides are used to locate intramedullary and extramedullary osteotomies. The operator uses the naked eye, feel and experience to locate anatomical landmarks, the line of force of the lower limbs and the axis of rotation of the prosthesis. Osteotomy, prosthetic placement, and soft tissue balancing are then hand-marked. The positioning and alignment based on the naked eye observation of the limbs and prosthesis is highly subjective, which directly affects the reliability of the positioning method and the accuracy of the operation, and even leads to the failure of the operation. Although people continue to improve the mechanical positioning system to improve the accuracy of prosthetic implantation, the inherent limitations of the system itself determine its possible accuracy. It has been reported in the literature that even the most sophisticated mechanical positioning system is used by experienced doctors. The incidence of misalignment with the tibia by more than 3° was also at least 10%. Moreover, the mechanical positioning measurement system is based on the hypothetical standardized femoral anatomy and geometry, which may not be suitable for some specific cases. Therefore, the accuracy problem of the traditional surgical method is the main problem that plagues the surgeon. The determination of the center point of the knee joint is one of the key points for determining the force line of the lower limbs. Therefore, how to improve the accuracy of knee replacement and accurately establish the biological force line of the lower limbs requires accurate determination of the center point of the knee joint.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for determining the center point of the knee joint.

The purpose of the present invention is achieved through the following technical solutions: a method for determining the center point of the knee joint, which comprises the following steps:

S1. CT imaging of human lower limbs, and three-dimensional reconstruction of CT images;

S2. Use 3D modeling software to perfuse the three-dimensionally reconstructed knee joint space. The knee joint space consists of the articular surface of the distal femur except the interarticular fossa, the medial and lateral malleolus of the femur, the articular surface of the proximal tibia, and the medial and lateral malleolus of the tibia. The non-bone space formed by the package;

S3. Find the center point of the perfusion body through 3D modeling software, which is the center point of the knee joint.

Further, the three-dimensional reconstruction is constructed using Mimics software.

Further, the CT images are stored in .dicom format.

Further, the 3D modeling software is 3D Slicer.

Further, the 3D modeling software is Mimics.

The present invention has the following advantages: In traditional knee joint replacement, the doctor determines the line of force of the lower limbs according to the preoperative scan of the two-dimensional X-ray plain film of the patient's lower limbs, including the determination of the midline point of the knee joint, that is, by using a ruler under the X-ray plane Finding the midpoint of the connecting line between the medial condyle and the lateral condyle, this method not only brings great subjective randomness, but also is difficult to complete accurate positioning, and belongs to the two-dimensional definition of two-dimensional measurement. The present invention uses CT scanning DICOM data reconstruction Skeleton model, through the 3D modeling software to perfuse the non-bone space of the knee joint after 3D reconstruction, determine the center point of the knee joint from a 3D angle, reduce the human error caused by traditional manual measurement, and determine it in 3D space, with higher accuracy .

Description of drawings

Fig. 1 is a flow chart of the method of the present invention.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing, protection scope of the present invention is not limited to the following:

A method for determining the center point of the knee joint, as shown in Figure 1, comprises the following steps:

S1. CT imaging of human lower limbs, and three-dimensional reconstruction of CT images;

S2. Use 3D modeling software to perfuse the three-dimensionally reconstructed knee joint space. The knee joint space consists of the articular surface of the distal femur except the interarticular fossa, the medial and lateral malleolus of the femur, the articular surface of the proximal tibia, and the medial and lateral malleolus of the tibia. The non-bone space formed by the package;

S3. Find the center point of the perfusion body through 3D modeling software, which is the center point of the knee joint.

Wherein, the three-dimensional reconstruction is constructed using Mimics software; the CT image is stored in .dicom format; and the 3D modeling software is 3D Slicer or Mimics.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Equivalent replacements or changes to the inventive concepts thereof are all covered within the protection scope of the present invention.

Claims (5)

1. a method for determining the center point of the knee joint, is characterized in that it comprises the following steps: S1. CT imaging of human lower limbs, and three-dimensional reconstruction of CT images; S2. Use 3D modeling software to perfuse the three-dimensionally reconstructed knee joint space. The knee joint space consists of the articular surface of the distal femur except the interarticular fossa, the medial and lateral malleolus of the femur, the articular surface of the proximal tibia, and the medial and lateral malleolus of the tibia. The non-bone space formed by the package; S3. Find the center point of the perfusion body through 3D modeling software, which is the center point of the knee joint. 2. the determination method of a kind of knee joint center point as claimed in claim 1, is characterized in that, described three-dimensional reconstruction adopts Mimics software to construct. 3. The determination method of a kind of knee joint center point as claimed in claim 1, is characterized in that, described CT image is stored with .dicom format. 4. The determining method of a kind of knee joint center point as claimed in claim 1, is characterized in that, described 3D modeling software is 3D Slicer. 5. the determining method of a kind of knee joint center point as claimed in claim 1, is characterized in that, described 3D modeling software is Mimics.