CN113332008A - Method and system for determining length of femur in hip arthroplasty - Google Patents

Abstract

The invention relates to the technical field of medical information processing, in particular to a method and a system for determining the length of a femur in hip arthroplasty, wherein the method comprises the following steps: acquiring a normal leg CT image obtained by CT scanning the leg of a normal leg of a patient, and determining the length of the leg of the patient according to the normal leg CT image so as to determine the length of the femoral neck prosthesis; respectively carrying out space positioning on the highest point of a femoral ball and a osteotomy surface of a leg part implanted with the femoral neck prosthesis by adopting an optical sensor so as to determine a first relative distance between the highest point of the femoral ball and the osteotomy surface in real time; respectively carrying out space positioning on the anterior superior iliac spine and the sole of the leg implanted with the femoral neck prosthesis by adopting an optical sensor so as to determine a second relative distance between the anterior superior iliac spine and the sole in real time; and finally, determining the length of the femoral head prosthesis implanted in the leg of the patient so that the second relative distance and the length of the leg of the patient are within the allowable deviation range, and effectively improving the accuracy and speed of the length of the femoral neck in the hip arthroplasty.

Description

A method and system for determining the length of the femur in hip arthroplasty

technical field

The invention relates to the technical field of medical information processing, in particular to a method and system for determining the length of a femur in hip joint replacement.

Background technique

Total-hip-arthroplasty (THA) is the use of surgical methods to replace the articular surface, femoral head, and acetabulum destroyed by disease or injury with an artificial hip prosthesis, so as to remove the lesion, eliminate pain, and recover. It is widely used in the treatment of joint ankylosis, femoral head necrosis, osteoarthritis, rheumatoid arthritis and other hip joint diseases. Human bone quality declines with age. The elderly are a high-risk group of hip joint diseases, and total hip arthroplasty is one of the common methods for the treatment of hip joint-related diseases. As China ages, the demand for total hip arthroplasty will increase.

In the process of total hip arthroplasty, choosing the appropriate length of femoral head prosthesis is the key to the success of the operation. A reasonable size artificial prosthesis can reduce the unequal length of the lower limbs after surgery and help improve the patient's satisfaction with the operation. degree. Traditional total hip replacement surgery is easily affected by the mismatch of the selected prostheses and affects the therapeutic effect.

In the prior art, one is to design a measuring instrument to measure the length of the eccentricity, and directly use the instrument to measure the eccentricity to determine the size of the prosthesis after the femoral head is removed. However, due to the limited exposure of the replacement area and the deep location of the affected area in total hip replacement surgery, this type of measuring instrument cannot accurately measure the length of the femoral head, and this structure is not conducive to the surgeon's accurate reading of the length data.

Another method is to use traditional mechanical principles to construct a mechanical measurement device, use the femoral head after intraoperative resection for measurement, and use the measurement data to restore the original length of the patient. However, patients who usually need total hip replacement surgery will have severe deformation of the femoral head and acetabulum, so patients are likely to have problems with "long and short legs" before surgery, and this method is only a rigid measurement and cannot be Really guide the doctor how to choose the right prosthesis.

Another method is to use the 3D reconstruction method to measure the size of the femoral head preoperatively. The operation steps of this method are complicated, and the 3D modeling with the information obtained by X-ray and binocular camera will be affected by the imaging quality and shooting angle. At the same time, such data can only be used as a reference for the operation, and cannot provide much help to the doctor.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method and system for determining the length of the femur in hip arthroplasty, so as to solve one or more technical problems existing in the prior art, and at least provide a beneficial choice or create conditions.

In order to achieve the above object, the present invention provides the following technical solutions:

A method for determining the length of a femur in hip arthroplasty, the method comprising the following steps:

Step S100, obtaining a normal leg CT image obtained by performing CT scanning on the leg of the patient's normal leg, and determining the length of the patient's leg according to the normal leg CT image to determine the length of the femoral neck prosthesis;

Step S200, using an optical sensor to spatially locate the highest point of the femoral bulb and the osteotomy surface of the leg implanted with the femoral neck prosthesis, so as to determine the first point between the highest point of the femoral bulb and the osteotomy surface of the patient's leg in real time. relative distance;

Step S300, using an optical sensor to spatially locate the anterior superior iliac spine and the sole of the leg implanted with the femoral neck prosthesis, so as to determine the second relative distance between the anterior superior iliac spine of the patient's leg and the sole of the foot in real time ;

Step S400, determining the length of the femoral head prosthesis implanted in the patient's leg, so that the second relative distance and the length of the patient's leg are within an allowable deviation range.

Further, the step S200 includes:

After the implantation of the femoral neck prosthesis is completed, the spatial position of the optical positioning sphere captured by the optical positioning sensor is calculated according to the image data of the patient's leg acquired by the plurality of cameras during the operation, and the optical positioning The spatial position of the ball determines the first relative distance from the highest point of the femoral ball of the leg where the femoral neck prosthesis is implanted to the osteotomy surface;

Wherein, the plurality of cameras and optical positioning sensors are deployed above the operating table, and the optical positioning ball is attached to the patient's ilium.

Further, the step S300 includes:

During the operation of implanting the femoral neck prosthesis, the spatial position of the optical positioning sphere captured by the optical positioning sensor is calculated according to the image data of the patient's leg acquired by the plurality of cameras during the operation, and according to the optical positioning The spatial position of the ball determines a second relative distance between the anterior superior iliac spine and the plantar of the leg in which the femoral neck prosthesis is implanted.

Further, the first relative distance is determined in the following manner;

与截骨面的空间坐标

通过以下公式计算出股骨球最高点和截骨面之间的第一相对距离C1：Obtain the spatial coordinates of the highest point of the femoral ball determined by the optical positioning ball at the end of the probe in the optical positioning sensor

Spatial coordinates with the osteotomy plane

The first relative distance C1 between the highest point of the femoral ball and the osteotomy surface is calculated by the following formula:

Further, the second relative distance is determined by the following formula;

为髂骨上棘的空间坐标，

为脚底的空间坐标，l为髂骨上棘到脚底之间的第二相对距离。in,

is the spatial coordinate of the superior iliac spine,

is the spatial coordinate of the sole of the foot, and l is the second relative distance between the superior iliac spine and the sole of the foot.

A computer-readable storage medium on which a program for determining the length of the femur in hip replacement is stored, and when the program for determining the length of the femur in the hip replacement is executed by a processor, any of the above The steps of a method for determining the length of the femur in hip arthroplasty.

A system for determining femoral length in hip arthroplasty, the system comprising:

at least one processor;

at least one memory for storing at least one program;

When the at least one program is executed by the at least one processor, the at least one processor implements the method for determining the length of the femur in hip joint replacement according to any one of the above.

The beneficial effects of the present invention are as follows: the present invention discloses a method and system for determining the length of the femur in hip replacement surgery, the present invention performs rapid and accurate measurement of the length of the femoral neck in hip replacement surgery, and assists doctors in making surgical decisions, The doctor can select the appropriate femoral head prosthesis model for the patient according to the data of the femoral neck length, reduce the error of human subjective judgment, and improve the placement accuracy of the replacement prosthesis. The coordinate transformation measures the length of the femoral ball and the osteotomy surface. The invention can effectively improve the accuracy and speed of the femoral neck length in hip joint replacement.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

1 is a schematic flowchart of a method for determining the length of a femur in hip arthroplasty in an embodiment of the present invention;

2 is a schematic diagram of optically marking probes in an embodiment of the present invention;

FIG. 3 is a schematic diagram of a first relative distance after implantation into the medullary cavity in an embodiment of the present invention.

Detailed ways

The concept, specific structure and technical effects of the present application will be clearly and completely described below with reference to the embodiments and accompanying drawings, so as to fully understand the purpose, solutions and effects of the present application. It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict.

Referring to FIG. 1 , as shown in FIG. 1 , a method for determining the length of a femur in a hip arthroplasty provided in an embodiment of the present application, the method includes the following steps:

Step S100, obtaining a normal leg CT image obtained by performing CT scanning on the leg of the patient's normal leg, and determining the length of the patient's leg according to the normal leg CT image to determine the length of the femoral neck prosthesis;

In this example, before the operation, multi-slice spiral CT scan was performed on the femoral medullary cavity to obtain a two-dimensional image of the femoral medullary cavity, and the three-dimensional reconstruction was completed by medical image software, and the inner diameter of the femoral medullary cavity was measured and inserted into the medullary cavity. maximum depth. According to the comparison of the three-dimensional image obtained by the three-dimensional reconstruction of the acetabulum with the three-dimensional image of the normal leg, the appropriate acetabular and femoral head prostheses were determined. According to the patient's femoral head, acetabulum, inner diameter of the femoral medullary cavity, length of the femoral neck, the maximum depth that can be inserted into the medullary cavity and other parameters, the model of the prosthesis that is suitable for the patient's leg is determined as the prosthesis implanted in the patient's leg during surgery. After the prosthesis is implanted, the patient's leg is planned, and the ideal prosthesis implantation scheme is selected.

Step S200, using an optical sensor to spatially locate the highest point of the femoral bulb and the osteotomy surface of the leg implanted with the femoral neck prosthesis, so as to determine the first point between the highest point of the femoral bulb and the osteotomy surface of the patient's leg in real time. relative distance;

Step S300, using an optical sensor to spatially locate the anterior superior iliac spine and the sole of the leg implanted with the femoral neck prosthesis, so as to determine the second relative distance between the anterior superior iliac spine of the patient's leg and the sole of the foot in real time ;

Step S400, determining the length of the femoral head prosthesis implanted in the patient's leg, so that the second relative distance and the length of the patient's leg are within an allowable deviation range.

It should be noted that during the operation, the selected femoral neck prosthesis is implanted into the medullary cavity after the osteotomy. According to the actual situation of the medullary cavity, the depth of the femoral stem inserted into the medullary cavity may be different from the preoperative planning. Therefore, it is necessary to conduct real-time detection of the patient's leg during the operation, and process it according to the actual situation. After the implantation of the femoral neck prosthesis is completed, the distance between the highest point of the femoral ball of the patient's leg and the osteotomy surface should be determined in real time. The first relative distance, the difference between the length of the patient's leg and the first relative distance is used as the basis for the preliminary determination of the size of the femoral head prosthesis, and the difference generated in the actual operation is compensated by selecting a suitable range of the femoral head prosthesis . During the operation of implanting the femoral head prosthesis, the second relative distance is determined in real time as the length of the leg for replacement surgery, the length of the patient's leg is compared with the second relative distance, and the femoral head prosthesis is continuously adjusted The length of the second relative distance and the length of the patient's legs are within the allowable deviation range, that is, the lengths of the two legs after the operation are guaranteed to be within the allowable deviation range.

In this embodiment, the femoral neck prosthesis can be used as the main factor for matching the length of the patient's leg, and the femoral head is used as a further fine-tuning for the length of the patient's leg. The relative distance is used as the length of the patient's leg after implantation of the prosthesis. Through continuous adjustment, the length of the femoral head prosthesis implanted in the patient's leg is finally determined to ensure that the length of the patient's two legs is maintained within the allowable deviation range after surgery. .

When measuring the femoral neck length of patients during the operation, the traditional method uses mechanical instruments. Because the measurement of mechanical instruments is not universal, the operation is complicated; After the overall installation of the prosthesis, the measurement is carried out to determine whether the selection of the femoral head model of the prosthesis is reasonable. The invention performs the spatial positioning of the marking points on the patient's legs based on the optical sensor, and has the advantages of accurate and timely measurement results, simple and efficient measurement operations, and real-time data visualization.

In a preferred embodiment, the step S200 includes:

After the implantation of the femoral neck prosthesis is completed, the spatial position of the optical positioning sphere captured by the optical positioning sensor is calculated according to the image data of the patient's leg acquired by the plurality of cameras during the operation, and the optical positioning The spatial position of the ball determines the first relative distance from the highest point of the femoral ball of the leg where the femoral neck prosthesis is implanted to the osteotomy surface;

Wherein, the plurality of cameras and optical positioning sensors are deployed above the operating table, and the optical positioning ball is attached to the patient's ilium.

In a preferred embodiment, the step S300 includes:

During the operation of implanting the femoral neck prosthesis, the spatial position of the optical positioning sphere captured by the optical positioning sensor is calculated according to the image data of the patient's leg acquired by the plurality of cameras during the operation, and according to the optical positioning The spatial position of the ball determines a second relative distance between the anterior superior iliac spine and the plantar of the leg in which the femoral neck prosthesis is implanted.

In some embodiments, the optical positioning sensor is used by deploying multiple cameras and optical positioning sensors (motion capture, NDI optical navigator, etc.) over the operating table and attaching the optical positioning ball to the patient's ilium. For the capture of the optical positioning ball, the spatial position of the optical positioning ball is calculated according to the acquired image data. Combined with computer vision technology and image recognition technology, the model attitude of the rigid body formed by the optical positioning ball is calculated based on the vision system, so as to know the change of the patient's body position. The optical positioning ball has an optical positioning function and can be captured by an optical positioning sensor. During the operation, infrared optical technology is used to obtain the corresponding spatial coordinates in real time, and the distance is calculated to measure the highest point of the femoral ball to the osteotomy surface. actual length.

As shown in Figure 2, in one embodiment, based on the optical positioning sensor technology, the three-dimensional coordinate information of the optical positioning balls A, B, and C on the probe in the optical positioning sensor is fed back in real time during the operation, so as to calculate the detection The 3D coordinates of the needle tip. The three-dimensional coordinates of the optical positioning ball at the end of the probe are determined by the function transformation relationship D=F(A, B, C);

与截骨面的空间坐标

通过以下公式计算出股骨球最高点和截骨面之间的第一相对距离C1：As shown in FIG. 3 , in a preferred embodiment, the spatial coordinates of the highest point of the femoral ball determined by the optical positioning ball at the end of the probe in the optical positioning sensor are obtained.

Spatial coordinates with the osteotomy plane

The first relative distance C1 between the highest point of the femoral ball and the osteotomy surface is calculated by the following formula:

In this embodiment, the model of the femoral head that fits is determined according to the length of the femoral neck. After the prosthesis is installed, the lengths of the two legs are measured in real time for further verification and feedback to determine the model of the femoral head and the actual length of the femoral neck of the prosthesis. Fitting; it is necessary to quickly and easily measure the length of the patient's leg after implantation of the prosthesis and the length of the other normal leg. This solution is based on the optical positioning sensor technology, using the probe tip to measure the length from the superior iliac spine to the sole of the foot. The relative distance l between the points is the length of the patient's leg after implantation of the prosthesis. Make sure that the length of the patient's leg after the prosthesis is implanted during the operation is within the allowable error range of the length of the other normal leg. In some embodiments, according to the actual femoral neck length of the prosthesis, the model of the femoral head that meets the femoral neck length is selected from the manufacturer's prosthesis product table.

In a preferred embodiment, the femoral neck length is determined using the formula C1-r, where C1 is the relative distance between the highest point of the femoral ball and the osteotomy surface, and r is the radius of rotation of the femoral head.

In a preferred embodiment, the length of the patient's leg after implanting the prosthesis is the second relative distance l between the superior iliac spine and the sole determined by the optical positioning sensor, that is, the patient's leg after implanting the prosthesis length is:

为髂骨上棘的空间坐标，

为脚底的空间坐标。in,

is the spatial coordinate of the superior iliac spine,

is the space coordinate of the sole of the foot.

In the same way, the leg length l′ of the other normal leg can be calculated:

In this embodiment, a reasonable leg length should satisfy: |l′-l|<ε ₂ ; wherein, ε ₂ is the allowable error in the length of both legs.

In some embodiments, set ε ₂ =0.5cm, if the difference between the lengths of the two legs is greater than 0.5cm, the femoral head model needs to be changed, so as to adjust the actual prosthesis femoral neck length.

Corresponding to the method in FIG. 1 , an embodiment of the present invention further provides a computer-readable storage medium, where a program for determining the length of the femur in hip joint replacement is stored on the computer-readable storage medium. When the program for determining the length of the femur is executed by the processor, it implements the steps of the method for determining the length of the femur in hip arthroplasty according to any one of the above embodiments.

Corresponding to the method in FIG. 1 , an embodiment of the present invention further provides a system for determining the length of a femur in hip arthroplasty, the system comprising:

at least one processor;

at least one memory for storing at least one program;

When the at least one program is executed by the at least one processor, the at least one processor implements the method for determining the length of the femur in hip joint replacement according to any one of the above embodiments.

The contents in the above method embodiments are all applicable to the present system embodiments, the specific functions implemented by the present system embodiments are the same as the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

The processor may be a central processing unit (Central-Processing-Unit, CPU), or other general-purpose processors, digital signal processors (Digital-Signal-Processor, DSP), application-specific integrated circuits (Application-Specific-Integrated). -Circuit, ASIC), Field-Programmable-Gate-Array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc., the processor is the control center of the system for determining the length of the femur in the hip joint replacement, and is connected with various interfaces and lines A system for determining the length of the femur in a total hip replacement can operate the various parts of the device.

The memory can be used to store the computer program and/or module, and the processor implements the hip by running or executing the computer program and/or module stored in the memory and calling the data stored in the memory. Various functions of the system for the determination of femoral length in joint replacement surgery. The memory may mainly include a stored program area and a stored data area, wherein the stored program area may store an operating system, an application program required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the storage data area may store Data (such as audio data, phone book, etc.) created according to the usage of the mobile phone, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, internal memory, plug-in hard disk, Smart-Media-Card (SMC), Secure-Digital (Secure-Digital, SD) card, Flash-Card, at least one magnetic disk storage device, flash memory device, or other volatile solid-state storage device.

Although the description of the present application has been described in considerable detail and with particular reference to a few of the described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but should be considered by reference The appended claims, given the broadest possible interpretation of the claims in view of the prior art, effectively cover the intended scope of the application. Furthermore, the foregoing description of the present application in terms of the embodiments foreseen by the inventors is intended to provide a useful description, and those insubstantial modifications to the present application that are not presently foreseen may still represent equivalent modifications of the present application.

Claims (7)

1. a determination method of femur length in hip arthroplasty, is characterized in that, described method comprises the following steps: Step S100, obtaining a normal leg CT image obtained by performing CT scanning on the leg of the patient's normal leg, and determining the length of the patient's leg according to the normal leg CT image to determine the length of the femoral neck prosthesis; Step S200, using an optical sensor to spatially locate the highest point of the femoral bulb and the osteotomy surface of the leg implanted with the femoral neck prosthesis, so as to determine the first point between the highest point of the femoral bulb and the osteotomy surface of the patient's leg in real time. relative distance; Step S300, using an optical sensor to spatially locate the anterior superior iliac spine and the sole of the leg implanted with the femoral neck prosthesis, so as to determine the second relative distance between the anterior superior iliac spine of the patient's leg and the sole of the foot in real time ; Step S400, determining the length of the femoral head prosthesis implanted in the patient's leg, so that the second relative distance and the length of the patient's leg are within an allowable deviation range. 2. The method for determining the length of the femur in a hip arthroplasty according to claim 1, wherein the step S200 comprises: After the implantation of the femoral neck prosthesis is completed, the spatial position of the optical positioning sphere captured by the optical positioning sensor is calculated according to the image data of the patient's leg acquired by the plurality of cameras during the operation, and the optical positioning The spatial position of the ball determines the first relative distance from the highest point of the femoral ball of the leg where the femoral neck prosthesis is implanted to the osteotomy surface; Wherein, the plurality of cameras and optical positioning sensors are deployed above the operating table, and the optical positioning ball is attached to the patient's ilium. 3. The method for determining the length of the femur in a hip arthroplasty according to claim 2, wherein the step S300 comprises: During the operation of implanting the femoral neck prosthesis, the spatial position of the optical positioning sphere captured by the optical positioning sensor is calculated according to the image data of the patient's leg acquired by the plurality of cameras during the operation, and according to the optical positioning The spatial position of the ball determines a second relative distance between the anterior superior iliac spine and the plantar of the leg in which the femoral neck prosthesis is implanted. 4. The method for determining the length of the femur in a hip arthroplasty according to claim 3, wherein the first relative distance is determined in the following manner; Obtain the spatial coordinates of the highest point of the femoral ball determined by the optical positioning ball at the end of the probe in the optical positioning sensor

Spatial coordinates with the osteotomy plane

The first relative distance C1 between the highest point of the femoral ball and the osteotomy surface is calculated by the following formula:

5. The method for determining the length of the femur in a hip arthroplasty according to claim 4, wherein the second relative distance is determined by the following formula:

in,

is the spatial coordinate of the superior iliac spine,

is the spatial coordinate of the sole of the foot, and l is the second relative distance between the superior iliac spine and the sole of the foot. 6. A computer-readable storage medium, characterized in that, a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the hippocampus as claimed in any one of claims 1 to 5 is realized. Procedure for the determination of femoral length in joint replacement surgery. 7. A system for determining femoral length in hip arthroplasty, wherein the system comprises: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the method for determining the length of the femur in hip arthroplasty according to any one of claims 1 to 5.

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