KR102467242B1 - Total hip arthroplasty simulation method and device - Google Patents

Abstract

Total hip arthroplasty simulation apparatus according to the present invention includes a photographing unit for taking an X-ray picture of a patient; an image processing unit that stores the photo data taken by the photo capturing unit in a first layer, extracts a femur image corresponding to the affected part from the first layer, and divides it into a second layer; Using the image data taken by the photographing unit, the patient's abnormal condition is analyzed from the physical dimensions and angles of the affected hip joint and the normal hip joint, and motion such as physical dimensions and range of motion predicted from the normal hip joint condition Image analysis unit to determine the characteristics; and a template recommendation unit that provides a doctor in charge of the patient with images according to a plurality of standards of an implant to be inserted into the hip joint on the side of the affected part and selects a template.

Description

Total hip arthroplasty simulation method and device

The present invention relates to a method and apparatus for simulating total hip arthroplasty, and more particularly, provides a method and apparatus capable of assisting in determining the physical dimensions and position of an implant to be inserted in total hip arthroplasty.

BACKGROUND OF THE INVENTION An increasing number of patients suffer from joint damage due to diseases or accidents. In some cases, the damage to the joint part is healed by the body's natural healing ability, but if it is not recoverable, or if the pain caused by the damage to the joint part is severe, artificial joint replacement surgery should be performed.

Various artificial joint surgery methods and artificial joint products are being used, but basically, artificial joint replacement surgery precisely cuts the surgically damaged bone and cartilage on both sides of the joint, and then inserts an artificial product to replace the role of the joint into the bone. refers to the fixation process.

Currently, it is known that about half of all artificial joint replacement surgeries are hip joint replacement surgeries, most of the rest are knee joint replacement surgeries, and the rest are shoulder joints or finger joints.

The hip joint implant shown in FIGS. 1 and 2 may be used for hip replacement surgery. As shown in FIG. 1, the hip joint implant is composed of a head 110, a stem 120, and a neck 123, and an acetabular cup 150 is fixed to the pelvic joint bone. The head 110 is accommodated in the shell 155 with a liner interposed therebetween and replaces the hip joint by rotating within a certain angle.

On the other hand, conventionally, the transparent templates shown in FIGS. 3 to 5 are checked in an overlapping manner on the patient's X-ray picture to determine the size and location of an implant suitable for the patient, and then total hip arthroplasty is performed accordingly. The size of the cap can be determined using the template of FIG. 3, and the position of the cap of that size can be determined on the x-ray photograph. Similarly, the size of the stem, neck, and head can be determined using the templates of FIGS. 4 and 5. Determine the offset and center of rotation of the joint.

However, in the case of these conventional methods, the precision of surgery may vary depending on the skill level of the surgeon, and if the size or center of rotation of the implant needs to be changed unintentionally due to an unintended error during surgery, leave the operating room and try again. It is inconvenient to recalculate the dimensions and location of the implant.

The present invention is to break away from the method of determining the size and angle of a femoral implant by randomly or sequentially overlapping femoral templates provided for each two-dimensional (plane) size, and to provide a surgeon with an X-ray picture. Provides a method that can be selected by providing data on an implant of a suitable physical standard and a device according to the method.

In addition, the present invention provides a method for predicting a postoperative result through simulation results of an implant having a selected size and location and providing information on an implant to be selected, and a device according to the method.

In addition, the present invention provides a simulation method and apparatus capable of quickly taking follow-up measures in response to errors that may occur during surgery.

Total hip arthroplasty simulation apparatus according to the present invention includes a photographing unit for taking an X-ray picture of a patient; an image processing unit that stores the photo data taken by the photo capturing unit in a first layer, extracts a femur image corresponding to the affected part from the first layer, and divides it into a second layer; Using the image data taken by the photographing unit, the patient's abnormal condition is analyzed from the physical dimensions and angles of the affected hip joint and the normal hip joint, and motion such as physical dimensions and range of motion predicted from the normal hip joint condition Image analysis unit to determine the characteristics; and a template recommendation unit that provides a doctor in charge of the patient with images according to a plurality of standards of an implant to be inserted into the hip joint on the side of the affected part and selects a template.

In addition, it may include a simulation unit that calculates joint characteristics and motion characteristics according to physical size and angle by simulating the postoperative state of the affected area according to the specifications of the acetabular cup, head, and stem selected through the template recommendation unit.

In addition, the simulation unit may evaluate the joint characteristics and motion characteristics of the affected part by comparing them with the joint characteristics and motion characteristics of the normal side.

In addition, an error response prediction unit providing data on the type of error that may occur when surgery is performed according to the physical size and location of the implant selected through the template recommendation unit and the standard change value data according to the error value of the type; can do.

Also, the standard variation value data may be a data table including a plurality of data pairs of variation values corresponding to error values.

In addition, the type of error may be at least one of stem size error, stem insertion depth error, acetabular cup insertion depth error inside the acetabular cup, acetabular cup size error, and acetabular cup insertion angle error.

Also, the corresponding value according to the type of error may be a variation value of at least one of the depth of the receiving groove in the head of the implant, the offset of the implant, the length of the stem of the implant, and the size of the stem of the implant.

In addition, the template recommendation unit may provide an acetabular cup image of the implant according to a plurality of standards, and determine the size of the acetabular cup, the position of the acetabular cup, and the center of rotation of the acetabular cup on the third layer from the doctor.

Also, the template recommendation unit may mark a rotation center of the acetabular cup determined by the doctor.

In addition, the template recommendation unit may provide images of the head and stem of the implant according to a plurality of standards, and select the size, position, and depth of the receiving groove of the head and the offset, length, and size of the stem on the fourth layer from the doctor. have.

In addition, the template recommendation unit may be positioned so that the center of rotation of the acetabular cup coincides with the center of rotation of the head.

According to the present invention, the size and angle of the femoral implant are determined by randomly or sequentially overlapping existing femoral templates provided for each two-dimensional (plane) size, and the size and angle of the femoral implant are determined. Efficient doctor selection can be assisted by providing data on phosphorus-standard implants so that they can be selected.

In addition, according to the present invention, comparison of surgical results can be performed in various ways by providing information on the implant to be selected or by predicting the result after surgery through simulation results by the implant of the selected size and location.

In addition, the present invention can prevent delays during surgery by promptly taking follow-up measures in response to errors that may occur during surgery.

1 and 2 are photographs showing an example of an implant used in total hip arthroplasty.
3 to 5 are photographs showing a template for selection of an acetabular cup and stem according to an embodiment.
6 is a block diagram showing a total hip arthroplasty simulation device according to an embodiment.
7 is a schematic diagram illustrating physical specifications of a stem according to an exemplary embodiment.
8 is a flowchart illustrating a method for simulating total hip arthroplasty according to an embodiment.
10 to 11 are images illustrating a process of selecting an implant using each layer.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Unless there is a specific definition or reference, the terms indicating directions used in this description are based on the state shown in the drawings. In addition, the same reference numerals refer to the same members throughout each embodiment. On the other hand, the thickness or dimensions of each component shown in the drawings may be exaggerated for convenience of description, and it does not mean that the dimensions or proportions between the components should actually be configured.

A total hip arthroplasty simulation device 200 according to an embodiment will be described with reference to FIGS. 6 and 7 . 6 is a block diagram showing a total hip arthroplasty simulation device according to an embodiment, and FIG. 7 is a schematic diagram for explaining specifications of an artificial joint implant.

The artificial joint simulation device 200 according to the present embodiment includes a photo taking unit 210, an image processing unit 220, an image analysis unit 230, a simulation unit 240, and an error response prediction unit 250.

The photographing unit 210 secures basic data by taking MRI or CT pictures including X-ray pictures including the pelvis and femur of a specific patient. The photo capturing unit 210 places and captures markers at regular intervals so that the length between specific points in the captured image can be calculated using the markers.

The image processing unit 220 stores the captured photo data as a first layer, extracts an image of the femur part from it, and divides it into a separate layer, that is, a second layer.

The image analysis unit 230 uses the image data captured by the photographing unit 210 to calculate the angle of engulfment and valgus from the physical dimensions and angles of the femoral head, acetabulum, femoral diameter, etc. of the normal affected hip joint and the opposite hip joint, and valgus. Analyze the condition of the patient, such as hip and varus, and grasp the motion characteristics such as physical dimensions and range of motion predicted from the condition of the normal hip joint.

The template recommendation unit 240 displays an acetabular cup image that can be layered in various sizes on a third layer to allow the doctor to select it in order to determine the size, location, and head depth (center of rotation) of the acetabular cup. let it be Also, the template recommendation unit 240 may provide head and stem images for selecting a head and stem on the fourth layer.

The template recommendation unit 240 may simply provide data by removing and displaying acetabular cups, heads, and stems of unapplicable sizes from the list from the data analyzed by the image analysis unit 230, and more actively It is also possible to recommend a method of recommending implant components having an appropriate standard analyzed from the image. Finally, the images of the presented list are sequentially applied to the corresponding layer, and the doctor selects an acetabular cup, head, and stem of appropriate specifications, and selects the location of the corresponding components.

The simulation unit 250 predicts the joint characteristics of the affected area after surgery through the specifications of the acetabular cup, head, and stem finally selected through the template recommendation unit 240, and uses the image of the predicted postoperative state Simulations such as leg length comparison and condition comparison with the normal side are performed, and the results are displayed to the doctor. At this time, it is also possible to display expected problems related to the physical exercise state together. In addition, the simulation unit 250 may perform a simulation for each standard of the acetabular cup, head, and stem to be recommended through the template recommendation unit 240, and present the result together with a recommendation list. That is, the simulation unit 250 may simulate the corresponding implant before and after determining the size and position for the surgery and provide the results to the doctor.

When the doctor selects the size and position of a plurality of components through the template recommendation unit 240, simulation results for each case may be displayed together, and the suitability of the selected standard and position may be evaluated in the simulation.

The error response prediction unit 260 provides a database of errors that can actually occur when surgery is performed according to the selected physical specifications and location, and a specific error occurs, requiring follow-up measures due to changes in the physical specifications or location of the implant. Even in this case, data is provided so that doctors can respond quickly without leaving the operating room and going through separate calculations and operations. If the type of error that can occur and the corresponding values according to the change in the corresponding physical standard are provided in advance, surgery is performed in response to the error that occurred quickly by preparing an implant of a preliminary standard in addition to the implant of the determined physical standard. can make it progress. That is, by presenting the type of error, a list of possible specification changes for the type of error, the amount of change in motion characteristics for each item in the list, or comparison data between the changed motion characteristics and the analysis value of the normal motion characteristics, surgery can be performed promptly in response to the error. allow it to proceed.

For example, when the stem is inserted 1 mm less or more into the femur, an error has occurred compared to the planned situation, and if the surgery is performed as it is, a problem of shortening or lengthening the leg may occur. In the past, there was a case of ad hoc response, such as recalculating it out of the operating room and replacing it with a stem or head of a suitable standard for the calculated item, restarting the operation in the operating room, or inserting a stem by grinding a bone with an eye patch. In the case of the error response prediction unit 260 according to the present embodiment, in preparation for possible errors, the stem and head specifications according to the follow-up measures are presented in the form of a list for each data, so that the errors can be quickly responded to.

These surgical errors may occur due to various causes. Although the human body has a three-dimensional shape, it is possible for errors to occur due to limitations in the photographing stage, and although photographing should be performed in an anatomical position, errors may occur because most photographing is not conducted in an ideal state. may occur, and an error may occur depending on the presence or absence of a gap between the bone marrow and the cortex. Errors may occur during surgery due to such complex causes, and it is difficult to eliminate errors only with images taken.

The error response prediction unit 260 eliminates the need for a separate calculation by providing the classification of the generated error by type, the changed countermeasure according to the size of the error, and the stem and head specifications according to the classification as a data set or data table.

For example, if there is a difference between the size determined before surgery and the stem size required when applied during actual surgery, it is possible to change simply by inserting a stem of a different size and selecting an appropriate one. The stem size was determined to be 3 before surgery and was applied in the actual surgery. If there is room in the bone inside the proximal femoral area where the implant is to be inserted, the size is increased, and if there is no room, the size is lowered.

If there is a difference in stem insertion depth, the depth of the receiving groove of the head is changed or the offset of the stem is changed. When the stem is inserted into the femur, there are cases where the stem goes in less or more. At this time, in order to match the length of the leg (almost similar to that of the opposite leg), adjust the depth of the receiving groove on the head. If the legs are longer than the normal side, select a head with a deep depth and insert the stem to expose the neck relatively short. If the legs are shorter than the normal side, select a head with a deep depth.

On the other hand, changing the offset of the stem is related to stability. Referring to FIG. 7, it has characteristics for major physical standards such as stem length (A), offset (B), leg adjustment length (C), and neck length (D). The configuration of the stem inserted into the thigh and the distance to the head correspond to the stem length (A) and the leg adjustment length (C). As described above, when the depth of the receiving groove of the head is changed to adjust the insertion depth, the center of rotation is changed and the offset is also changed. In this case, since the position of the femur is moved toward the center of the body compared to the normal femur on the opposite side, there may be a problem with stability, and it is necessary to increase the offset. In this case, leg length adjustment and maintenance of stability can be maximized by adjusting the stem length (A), offset (B), and neck length (D), and this simulation is performed by comparing the results calculated by the simulation unit. can do.

As another example of the error, when a difference occurs in the insertion depth of the acetabular cup, the depth of the head receiving groove or the offset of the stem is changed or the length of the stem is adjusted.

When the acetabular cup is inserted into the acetabulum deeper than expected, the center of rotation may shift to the acetabular side and the length of the leg may be shortened. In this case, the length of the leg is adjusted by selecting a head with a shallow depth of the receiving groove so that the neck is exposed relatively long from the head. When the cup is inserted into the acetabulum, it is stable, but when it is inserted shallowly, the length of the legs may increase. However, even in this case, since the offset may increase or decrease due to the variation of the leg adjustment length C, it is possible to provide data to ensure stability as much as possible along with the adjustment of the leg length through the adjustment of these values.

In general, when a trial artificial joint is inserted, if it is unstable, such as easily dislocated in the hip joint safety test, a method to increase safety by increasing the offset was used. data is provided.

In addition, when an error occurs according to the size of the acetabular cup, the size is re-determined in consideration of the contact surface between the acetabular cup and the acetabulum and the degree of exposure or burial of the upper end.

In addition, when an error occurs in the angle of the acetabular cup compared to the predetermined angle, more complicated adjustment is required. The angle of the acetabular cup is generally such that the bottom of the hemisphere (receiving side of the head) forms an angle of 45 to 50 degrees with respect to the central axis of the body. In this case, not only the length of the legs is different than expected, but also the angle of immersion is changed, which can cause various deformations of the legs. Even in this case, balance, stability, motion characteristics, etc. after surgery are evaluated through simulation, and suitable modified specifications are provided to the doctor in the form of a data table, etc., so that a template can be selected or quickly coped with during surgery.

A total hip arthroplasty simulation method according to an embodiment will be described with reference to FIGS. 8 to 11 . 8 is a flowchart illustrating a method for simulating total hip arthroplasty according to an embodiment, and FIGS. 10 to 11 are images illustrating a process of selecting an implant using each layer.

First, after taking an X-ray picture, it is prepared as a first layer, and the femur is recognized from the X-ray picture and separated into a second layer (S100). At this time, an X-ray picture is taken in an anatomical position, and a marker at a certain interval (eg, 10 cm) is placed and taken, and the size of the implant can be determined and calibrated using this.

Next, the acetabular cup size, positioning, and head depth (center of rotation) are determined on the third layer (S200). As shown in FIG. 9 , images of the acetabular cup are provided on the third layer according to various sizes so that the size and position of the acetabular cup can be determined. An appropriate size of the acetabular cup and the position of the center of rotation of the artificial joint are determined in consideration of the femoral anvesion on the first layer. At this time, the size is determined by referring to the inner margin, and the center of rotation may be marked on the third layer in consideration of the optimal position and bone contact. The determined center of rotation is related to determining the depth of the stem receiving groove of the head.

Next, as shown in FIG. 10, the head and stem are selected on the fourth layer (S300). First, determine the insertion size, offset, and head depth of the implant head (ball). Since the head is provided according to the depth of the accommodating groove accommodating the stem (particularly the neck), the length of the neck exposed from the head changes when the depth of the accommodating groove changes, and accordingly, the position of the rotation center of the stem changes.

After that, the stem is selected. Select a stem size that fits the proximal femur and equals the length of the leg. Stem images are available in standard offset or high offset options for all stem sizes. Determine the option to restore the proper offset by matching the center of rotation of the cup to the desired center of rotation of the head.

Next, simulation is performed on the dimensions and positions of the selected acetabular cup, head, and stem (S400). However, as described above, simulation can also be performed for a plurality of selections, and even when data of implant components for a plurality of specifications and positions are provided to a doctor, etc. for selection, data for comparative analysis can be obtained through this. can be provided together. As an example of the simulation performed at this time, as shown in FIG. 11 , a method of calculating a leg length difference by comparing vertical lengths from both lower ends of the pelvic bones to the greater or lesser trochanter of the femur may be considered.

When the selection of the final specification and position is completed, a data table for correction values according to possible error types and error values for each type is provided (S500).

Although the preferred embodiments of the present invention have been described above, the technical spirit of the present invention is not limited to the above-described preferred embodiments, and can be implemented in various ways within the scope of the technical spirit of the present invention embodied in the claims. have.

210: photographing unit
220: image processing unit
230: image analysis unit
240: template recommendation unit
250: simulation unit
260: error response prediction unit

Claims (11)

A photographing unit for taking an X-ray picture of a patient;
an image processing unit that stores the photo data taken by the photo capturing unit in a first layer, extracts a femur image corresponding to the affected part from the first layer, and divides it into a second layer;
The patient's abnormal state is analyzed from the physical dimensions and angles of the affected hip joint and the normal hip joint using the image data captured by the photographing unit, and at least any one of the physical dimensions and range of motion predicted from the normal hip joint condition is analyzed. An image analysis unit for identifying one or more motion characteristics; and
A template recommendation unit for providing a doctor in charge of the patient with images according to a plurality of standards of an implant to be inserted into the affected hip joint and receiving a selection;
A simulation unit that calculates joint characteristics and motion characteristics according to physical size and angle by simulating the postoperative state of the affected area according to the specifications of the acetabular cup, head, and stem selected through the template recommendation unit;
The simulation unit evaluates the joint characteristics and movement characteristics of the affected part by comparing them with the joint characteristics and movement characteristics of the normal side,
An error response prediction unit that provides standard variation value data according to the type of error that can occur when surgery is performed according to the physical specifications and location of the implant selected through the template recommendation unit and the error value of the corresponding type; ,
The standard variation value data includes a plurality of data pairs of variation values corresponding to error values,
The type of error is at least one of stem size error, stem insertion depth error, acetabular cup acetabular insertion depth error, acetabular cup size error, and acetabular cup insertion angle error,
The corresponding value according to the type of error is a variation value of at least one of the depth of the receiving groove in the head of the implant, the offset of the implant, the stem length of the implant, and the stem size of the implant,
The template recommendation unit provides an acetabular cup image of the implant according to a plurality of standards to determine the size of the acetabular cup, the location of the acetabular cup, and the center of rotation of the acetabular cup on a third layer from the doctor;
The template recommendation unit marks the center of rotation of the acetabular cup determined by the doctor;
The template recommendation unit provides images of the head and stem of the implant according to a plurality of standards, and selects the size, position, and depth of the receiving groove of the head and the offset, length, and size of the stem on a fourth layer from the doctor,
The total hip arthroplasty simulation device for positioning the template recommendation unit to match the center of rotation of the acetabular cup and the center of rotation of the head. delete delete delete delete delete delete delete delete delete delete

Images