JP2009195490A - Program for preoperative plan of artificial hip joint replacement, and instrument for supporting the replacement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correctly determine the reaming operation of pelvis acetabular cup, the scission of a femoral head, and the reaming operation from an osteotomy surface by appropriately reflecting the individual difference of a patient. <P>SOLUTION: A computer is allowed to perform: an image reconstitution step (S101) for inputting a plurality of two-dimensional tomographic images of pelvis including the cup and reconstituting at least the three-dimensional image of the pelvis including the cup; artificial joint determination steps (S102-S104) for determining an artificial joint to be replaced and the arrangement position, based on the three-dimensional image of the femoral cup obtained in the image reconstitution step; and parameter determination steps (S105, S106) for determining respective kinds of parameters to be used in the reaming operation to embed the artificial joint into the femoral cup, based on the artificial joint determined in the artificial joint determination steps, the arrangement position, and the reference point of the cup in the three-dimensional image. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a preoperative planning program for an artificial hip joint replacement surgery using a data processing device such as a personal computer and a surgical support jig.

  The knee joint and hip joint constituting a part of the human lower limb are particularly important joints in daily life such as walking. Due to the size of the necessity, it is also a site that is susceptible to trauma, and the cartilage of the joint part is degeneratively destroyed with aging, leading to arthropathy.

  As a surgical treatment for this arthropathy, artificial arthroplasty (Total Arthro-Plasty) that removes the broken cartilage, inserts a metal therein, and reconstructs the joint function by contacting the metal with a plastic such as polyethylene, is available. As a method that can improve the most stable function, it is currently being performed all over the world.

  At this time, the femoral component and tibial component in the artificial knee joint, and the installation positions of the femoral stem and acetabular cup in the artificial hip joint, that is, the accuracy of the extraction (osteotomy) of the respective bones is the accuracy of the subsequent artificial joint. It greatly affects the durability.

  Conventionally, regarding the placement of this artificial joint, the position and size of the above-mentioned components, stems, and cups are obtained by matching the outline of the artificial joint printed on a transparent sheet with the X-ray photograph taken from the front and side before surgery. Had decided. However, in such a method, grasping of the bone shape is affected by the photographing direction of the X-ray photograph and the position of the patient at the time of photographing, and lacks accuracy.

In order to solve this problem, X-ray photography was performed on the front in two standing directions and at an oblique angle of 60 ° on a special photographing stand in which the position between the film and the irradiation point was previously determined by a calibration frame. The bone shape three-dimensional model created from the X-ray CT apparatus and MRI apparatus is aligned with each bone shadow (image matching) on the image, and the three-dimensional shape of the standing bone shape that serves as the reference for the installation position A method using computer software that performs accurate grasping has been considered. In this computer software method, the size and position of the artificial joint suitable for the bone shape and the load environment can be determined by reading out a plurality of three-dimensional shape models based on CAD (Computer Aided Design) data of the artificial joint. . (For example, Patent Document 1)
JP 2004-008707 A

  However, the technique described in Patent Document 1 is merely a technique that allows an operator to easily know the osteotomy surface on the tibial side in artificial knee joint replacement, and has different bone shapes and functional axes. It cannot be directly applied to the femur side or other joints, for example, hip joints that are also important in the lower limbs.

  The present invention has been made in view of the above circumstances, and the object of the present invention relates to hip replacement surgery, and appropriately reflects the individual differences of patients before surgery, For preoperative planning of hip replacement surgery that can accurately determine the femoral head cutting and reaming action from the cut surface, and can manage the surgical operation that accurately reproduces the contents determined preoperatively during the operation It is to provide a program and a jig for surgery support.

  According to the first aspect of the present invention, an image input step of inputting a plurality of two-dimensional tomographic images of the pelvis including the acetabulum and a three-dimensional image of the pelvis including at least the acetabulum from the plurality of images input in the image input step are reproduced. An image reconstruction step to be constructed, an artificial joint determination step for determining an artificial joint to be replaced and an installation position from a three-dimensional image of a pelvic acetabulum obtained in the image reconstruction step, and a determination in the artificial joint determination step A parameter determination step for determining various parameters used in the reaming operation for embedding the artificial joint in the pelvic acetabulum based on the artificial joint and its installation position and the reference point of the acetabulum in the three-dimensional image. The computer is executed.

  According to a second aspect of the present invention, in the first aspect of the invention, the parameter determining step is based on the position coordinates of three points on the acetabular edge and the normal vector of the artificial joint at the installation position. Various parameters including a distance from a disk formed by three points on the lid edge to the bottom surface of the acetabulum are determined.

  The invention according to claim 3 is the invention according to claim 2, wherein the three points on the acetabular margin are planes (XZ plane) including the three points of both the anterior superior iliac spine and the pubic joint center. Two points on the acetabular edge located in the XY plane including the femoral head center of the pelvic coordinate system set with the center as the origin, and one of the closest points in the Z-axis direction of the pelvic coordinate system on the acetabular edge It is characterized by being a point.

  According to a fourth aspect of the present invention, there is provided an image input step of inputting a plurality of two-dimensional tomographic images of a femur including a hip joint, and a three-dimensional image of a femur including at least a hip head from the plurality of images input in the image input step. An image reconstructing step for reconstructing, an artificial joint determining step for determining an artificial joint to be replaced and an installation position from the three-dimensional image including the femoral head obtained in the image reconstructing step, and the artificial joint determination Various parameters used in the bone marrow reaming operation for embedding the artificial joint after cutting the femoral head and neck based on the artificial joint determined in the step and its installation position and the reference point of the bone head in the three-dimensional image. A parameter determining step for determining is executed by a computer.

  In the invention described in claim 5, in the invention described in claim 4, the parameter determining step determines various parameters indicating the distance and direction of the femoral bone marrow axis with respect to the cut surface of the femoral head and neck. It is characterized by.

  The invention according to claim 6 supports the hollow shaft portion indicating the reaming axis direction of the pelvic acetabulum and the ball bearing portion that penetrates and supports the hollow shaft portion and is slidable in the radial direction, and includes a screw portion. The disc-shaped holder portion that can fix the rotation position and slide position of the ball bearing portion by fastening, a holder mounting surface for mounting the disc-shaped holder portion, and a paper surface at a predetermined distance across the holder mounting surface And a frame body for determining the direction of the disk-shaped holder, which includes first and second paper surface mounting portions to be mounted.

  The invention according to claim 7 is the invention according to claim 6, wherein the disk-shaped holder portion is moved along the circumference, and the protruding amount is projected outward from the circumference in the radial direction. It is characterized by comprising three indicating members that can be adjusted together.

  According to an eighth aspect of the present invention, there is provided a first attachment portion having a flat plate-like portion attached in the vicinity of the head and neck of the femoral body, and a first attachment portion detachably provided on the first attachment portion. The head and neck are cut from the gap between the plate-like portion of the second attachment portion having a plate-like portion to be attached to the femoral head at a distance from the plate-like portion of the head portion, and the plate-like portions of the first and second attachment portions. A hollow shaft portion detachably attached to the first and second mounting portions, showing a reaming axis direction with respect to the cut surface, and a ball bearing portion attached to the second mounting portion and penetrating and supporting the hollow shaft portion. A disk-shaped holder part that is supported rotatably and slidable in the radial direction, and can fix the rotational position and sliding position of the ball bearing part by fastening the screw part, and preoperatively the cut femoral head The holding part corresponding to the shape at the time of planning, the disk-like holder part and the upper A correction mechanism for holding the femoral head mounted with the second mounting portion and correcting the rotational position and slide position of the ball bearing portion of the disc-shaped holder portion according to the position and direction of the cut surface of the femoral head to be held. And a frame body provided.

  According to the present invention, it is possible to accurately determine the pelvic acetabular reaming operation and the femoral head cutting and reaming operation from the cut surface by appropriately reflecting the individual differences of patients before the operation. A sword that accurately reproduces the contents determined before surgery can be implemented.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(1. Preoperative plan)
FIG. 1 shows a hardware configuration of a personal computer (hereinafter “PC”) 10 in which a preoperative planning program for hip replacement is installed. The north bridge 12 is connected to the CPU 11 that controls various processes and the front side bus FSB.

  The north bridge 12 is further connected to the main memory 13 via the memory bus MB and to the graphic controller 14 and the graphic memory 15 via the graphics interface AGP, and is also connected to the south bridge 16 mainly between them. Execute I / O control.

  The south bridge 16 is connected to the PCI bus 17, keyboard / mouse 18, video encoder 19, hard disk device (HDD) 20, network interface (I / F) 21, and multi-disk drive 22. Input / output control with 12 is performed.

  In the hard disk device 20, in addition to the OS (operating system), various application programs, various data files, etc., a preoperative planning program for hip replacement surgery and the accompanying shape data of artificial joints and various jigs Etc. are installed in advance.

  The video encoder 19 generates and outputs an RGB video signal, which is an analog image signal, from a given digital image signal, and is composed of a color TFT (thin film transistor) liquid crystal display panel (not shown). The display unit is driven to display.

  The multi-disc drive 22 can reproduce and record an optical disc medium in accordance with, for example, a CD (Compact Disc) standard and a DVD (Digital Versatile Disc) standard, and can be used for patient X-ray photography, X-ray CT apparatus, MRI, and the like. It is assumed that the three-dimensional shape data of the patient's lower limbs can be input and recorded in the hard disk device 20 by reproducing and reading out the optical disk medium on which the tomographic photograph of the device is recorded.

  It should be noted that the individual elements constituting the PC 10 are very general well-known techniques, and therefore description thereof is omitted.

Next, the operation of the preoperative plan will be described.
FIG. 2 shows the processing contents of the present invention which are executed mainly by the CPU 11 when a doctor who is a user of the PC 10 activates a preoperative planning program stored in the hard disk device 20.

  When this preoperative planning program is executed, the 3D bone shape data of the patient's lower limb created from the 2D tomographic image data slice imaged by the X-ray CT apparatus or the MRI apparatus is read and stored in the hard disk device 20. It shall be.

  Further, three-dimensional shape data of the artificial joint and various jigs used during the operation are separately prepared and stored in the hard disk device 20 together.

  When the preoperative planning program shown in FIG. 2 is started, a GUI (graphical user interface) is displayed on the screen of the display unit connected to the video encoder 19, and the desired lower limb displayed on the GUI is displayed. The three-dimensional shape data in the standing position or the lying position is selected.

  This is performed by designating a folder storing the three-dimensional shape data of the lower limbs, which is used in a general PC program. In the three-dimensional shape data of the pelvis and the three-dimensional shape data of the femur, the three-dimensional positional relationship (three-dimensional alignment) in the standing position in the weighted state and the decubitus position in the extracted state is correctly arranged in advance. Shall.

(1-1. Pelvic acetabulum side)
Next, the three-dimensional shape data of the selected lower limb pelvis is read from the folder of the hard disk device 20 and expanded in the main memory 13, and an image of the three-dimensional shape data viewed from an appropriate viewpoint is displayed on the display screen ( Step S101). In this display, a three-dimensional image or three-dimensional shape data obtained by perspective projection can be two-dimensionally displayed in a cross section in a plane parallel to the coordinate axis.

For this three-dimensional image, the three points A, B, and C on the acetabular edge are designated as reference points (step S102).
FIG. 3 exemplifies the result of specifying the above three reference points. As the reference point, for example, a pelvic coordinate system (a plane including the three points of both anterior superior iliac spine and the pubic joint center (XZ plane)) 2) (B, C) on the acetabular rim located on the pelvic coordinate XY plane including the center of the femoral head, and the latest in the Z-axis direction of the pelvic coordinate system on the acetabular rim Digitize a total of three points (A, B, C), one point A.

  The three edge points may be arbitrary point positions, but by specifying the positions as described above, the three edge points can be easily referred to during the operation and can be easily used as a coordinate system of a jig described later.

  Assuming that the circumference passing through the three points (A, B, C) on the acetabular edge is a acetabular circle, a center vector of the acetabular circle and a ray vector with the center position O as the origin are created ( Step S103).

FIG. 4 is a diagram illustrating the center O of the acetabular circle passing through the three points (A, B, C) and the ray to the bottom of the acetabulum passing through the center O. The acetabular circle passing through the three points and its radial dimension can be calculated.
In this case, in the software, the acetabular circle plane is the YZ plane, the acetabular circle normal vector is the X axis, the plane passing point of the normal vector is the center, and the Z axis direction is the same as in the pelvic coordinate system. Define and display the cross-section and sagittal plane of this jig coordinate. From the two cross sections, the cup normal vector passing position is determined on an acetabular plane or an arbitrary plane up and down, and the position is calculated.

  By referring to the radial dimensions of the acetabular circle thus obtained, the three-dimensional shape data of the acetabular cup (hereinafter referred to as “cup”), which is an artificial joint for the pelvic acetabulum, is selected from the size of the acetabular margin Then, the data is read from the hard disk device 20 and displayed on the display screen (step S104).

  By optimally arranging the cup on the acetabulum, the ray vector of the cup, that is, the reaming direction is calculated (step S105).

  In the slice view on the calculated cup ray vector, the distance from the acetabular circle center O to the cup bottom surface and the acetabular bottom surface is calculated (step S106).

  In addition, an arbitrary 2XY plane in the X-axis direction in this jig coordinate (plus 100 [mm] and minus 50 [mm] from the design of the adjustment tool for artificial hip joint replacement surgery for determining the direction of the disc-shaped holder presented earlier) The passing point of the cup normal vector in the plane is detected and the position is calculated, or the surface is printed.

  The distance from the center of the acetabular circle to the positions of points A, B, and C is calculated and printed out in the coordinate system of the jig.

  Next, the set ray vector of the cup is displayed. At this stage, the cross section of the bone shape model in the jig coordinate system is also displayed.

  For this purpose, as shown in FIG. 6, it is necessary to construct a coordinate system for the acetabulum and the cup with CO as the cup origin and CB as the cup bottom point. The positional relationship with the acetabular position is a three-dimensional installation position preoperative plan, and this relationship is known in this intraoperative support operation management. Therefore, the cup normal vector is simply displayed (step S107).

FIG. 7 shows the acetabular coordinate system of each item obtained by this coordinate transformation together with the image at the acetabular part, FIG. 7A is the image, and FIG. 7B is the acetabular coordinate of each item. The system coordinate value is illustrated. As shown in FIG. 5B, the coordinates of the points A to C on the acetabular edge with respect to the acetabular origin (0, 0, 0) are shown. Each vector in FIG.

  When the acetabular coordinate system is obtained as described above, the cup ray vector expression in the acetabular coordinate system is then obtained. Consider a ray vector passing from the cup bottom point CB to the cup origin CO as shown in FIG.

By calculating the coordinate system of the cup origin and the cup bottom point as shown in FIG.
X = aZ + b, Y = a′Z + b ′ (2)
Thus, the coefficients a, b, a ′, and b ′ have values as shown in FIG.

  A full-size sheet centered on the circumferential center O of the three edge points (A, B, C) is printed out on a plane along the acetabular circle. At this time, since the jig coordinate system is defined with the Z axis of the pelvis coordinate system being the same, the point A is always located at a point directly above the center of the circle.

  Also, with the upper 100 [mm] and the lower 50 [mm] parallel to the plane along the acetabular circle, centered on the position corresponding to the circumferential center O of the three edge points (A, B, C), In addition, a full-size sheet in which the position of the passing point of the cup normal vector is written is printed out.

  The pre-operative processing on the pelvic acetabulum side is completed as described above, and the obtained conversion result and the like are stored and set in the hard disk device 20 (step S108).

(1-2. Femoral head side)
Next, the operation proceeds to preoperative treatment on the femoral head side.
On the femoral head side, in order to install a femoral head artificial joint (FIG. 15B), which will be referred to as a stem below, reaming is performed in the bone marrow direction of the femur with the long axis direction of the stem as the Z axis. This stem coordinate system is determined by the position of the Z axis indicating the reaming direction and the center of the stem head in order to make a relative evaluation of the stem position with respect to the femoral coordinate system in the pre-operative installation position plan.

Specifically, an attachment position of a stem installation jig (to be described later) is determined on the Z-axis direction of the stem coordinates at a point proximal to the femur where bone marrow reaming is performed (step S109).
Here, as the jig coordinates, the stem coordinates that coincide with the stem major axis direction are displayed as the Z axis, and the XY plane orthogonal to the Z axis at the height position of the head center is displayed. The passing point of the stem Z-axis is the origin of the jig coordinate system, and centered here is the position of 40 [mm] in the YZ direction, and 80 [mm] on one side of 80 [mm] in the XY direction (the direction of the head center). ] Is set.

  From the bone-shaped cross-section (XY plane), the position of the bone head margin in the origin X direction (nearest point) and the position of the bone border bone contour 10 [mm] proximal from this position are set on the bone center plane It is specified by calculating the distance from the side and top and bottom surfaces of the legislative body.

  Further, the position of the peripheral edge of the head of the head, which is 10 [mm] proximal in the direction of the origin Y-axis, is specified from the cross section, and the distance from the cube side surface is calculated. It is necessary to specify the length of two points from the wall surface different from the latest position.

  However, it is assumed that it is difficult to specify the deformed bone head before the operation, and calculation points can be selected from cross sections of 10 [mm] and 20 [mm]. A screw hole for length adjustment is arranged at a corresponding position of the jig 70.

  The cross section and the sagittal plane display by the same stem coordinates are displayed at 30 [mm] position and 40 [mm] position from the nearest point. In this display, the positions of at least three points not on the same plane that can be clearly seen at the origin level 10 [mm] or 20 [mm] below from the surface shape of the femoral neck are calculated as reference points. (Step S110).

  The direction of the bone marrow reaming with respect to the bone marrow Z-axis is determined based on the stem mounting position and the reference point thus obtained (step S111), and the determined result is associated with the data on the pelvic acetabulum side together with the reference point. (Step S112), the preoperative planning process of FIG. 2 is completed, and the patient is prepared for hip replacement surgery for the patient.

(2. Surgery jig)
Next, various jigs used during the hip replacement surgery will be described.
(2-1. Pelvic acetabular side)
First, a jig for determining a reaming direction and a depth for mounting a cup as an artificial joint on the pelvic acetabulum side and a process of using the jig will be described with reference to FIGS. 9 to 13.
FIG. 9 shows a frame body that reproduces a parallel plane separated by a predetermined distance, for example, 100 [mm] above and a parallel plane separated by a predetermined distance, for example, 50 [mm], below the acetabular circle surface. 2 is a perspective view showing an external configuration of a jig 30. FIG.

  As shown in the figure, the frame body jig 30 is configured such that one flat plate 31 is fixedly arranged in parallel with the upper bottom surface 32 and the lower bottom surface 33 with respect to a rectangular parallelepiped having 12 prismatic frames. Each distance from the upper surface of the flat plate 31 to the upper bottom surface 32 and the lower bottom surface 33 is as described above. For example, a circular hole 34 having a diameter of 30 [mm] is formed in the center of the flat plate 31.

  FIG. 10 shows a configuration of the disk-shaped holder 40 and the hollow shaft 50 used in combination with the frame body jig 30. FIG. 4A shows the side structure of the disk-shaped holder 40 and the hollow shaft 50, and FIG. 4B mainly shows the planar structure of the disk-shaped holder 40 as viewed from the XX direction of FIG. Show.

  The disc-shaped holder 40 has a ball bearing 43 sandwiched in an oblong hole formed at the center of a pair of circular discs 41 and 42 and is screwed with screw portions 44 and 44, and the distance between the pair of circular discs 41 and 42. By changing the position of the ball bearing 43, the position and angle of the ball bearing 43 loosely fitted in the oval hole can be arbitrarily changed, and can be fixed if necessary.

  By tightening the knurled knob 46 formed at the end of the outer cylinder portion 45 formed integrally with the ball bearing 43, the position of the hollow shaft 50 loosely slidably fitted to the ball bearing 43 is fixed.

  The hollow shaft 50 is provided with a T-shaped handle 51 at the end as shown in the figure, and a center shaft 53 provided with a slider 52 is coaxially loosely fitted, and the position of the slider 52 with respect to the center shaft 53 is adjusted. Thus, the amount of the central shaft 53 protruding from the disk-shaped holder 40 side can be arbitrarily adjusted.

  A contact sensor is built in the tip of the center shaft 53 on the bottom side of the acetabulum so that the presence or absence of contact with the acetabulum bottom can be detected externally.

  Further, pointers 47A to 47C that are movable along the circumferential direction are provided on the outer peripheral portion of the disk-shaped holder 40, respectively. These pointers 47A to 47C are movable within an angle range of less than about 120 [°] at the center angle of the disc-shaped holder 40, and the moving positions can be fixed by tightening the screw portions 48A to 48C attached integrally. .

  Furthermore, the tips of the pointers 47A to 47C protruding to the outer peripheral sides are sharp point screw portions 49A to 49C screwed to the main bodies of the pointers 47A to 47C. For example, it can be adjusted within a range up to about 12 [mm].

  In addition, these point screw portions 49A to 49C have a built-in contact sensor for selection, and the presence or absence of contact with the acetabulum edge can be detected externally when the acetabulum edge point abuts.

  Accordingly, the disc-shaped holder 40 fitted with the hollow shaft 50 is fitted into the circular hole 34 formed in the flat plate 31 of the frame body jig 30 to indicate the reaming axis direction of the cup with respect to the pelvic acetabulum of the patient. be able to.

(2-1-1. Preoperative adjustment)
FIGS. 11A to 11C illustrate guide papers GP11 to GP13 that are printed out in the preoperative plan and are attached to the upper bottom surface 32, the flat plate 31, and the lower bottom surface 33 of the frame body jig 30. FIG. Is.
FIG. 11B is a guide paper GP12 simulating a acetabular circle surface to be attached to the flat plate 31. A circular hole is formed so as to coincide with the circular hole 34, and is shown in FIG. 3 to FIG. 5 and FIG. The three points A to C on the acetabular rim are accurately pointed by crosses based on the data obtained before the operation.

  FIG. 11A shows a guide paper GP11 that is attached to the upper bottom surface 32 that is 100 [mm] away from the upper surface of the acetabular circle surface, and the pass position UP of the cup radiation vector at the spatial position is the hard disk. Points are based on pre-operative data stored in the device 20.

  Similarly, FIG. 11C is a guide paper GP13 to be attached to the lower bottom surface 33 that is 50 [mm] away from the lower side of the acetabular circle, and a passing position DP obtained by extending the cup ray vector at the spatial position is a guide paper GP13. The point is based on data obtained before the operation stored in the hard disk device 20.

  After the circular holes corresponding to the thickness of the hollow shaft 50 are formed around the passing positions LP and DP of the guide papers GP11 and GP13, the guide papers GP11 to GP13 are attached to the upper bottom surface 32 and the flat plate 31 of the frame body jig 30. And affixed to the lower bottom surface 33.

  A flat plate on which the guide paper GP12 is affixed in a state where the screw portions 44, 44 of the disc-shaped holder 40 are loosened so that the position and direction of the ball bearing 43 relative to the circular discs 41, 42 can be arbitrarily adjusted. The hollow shaft 50 passes through the opening of the passing position LP of the guide paper GP11 stuck on the upper bottom surface 32 and the opening of the passing position DP of the guide paper GP13 stuck on the lower bottom surface 33. Position to do.

  FIG. 12A shows a state in which the guide holders GP11 to GP13 are attached to the corresponding positions of the frame body jig 30 as described above, and the disk-shaped holder 40 with the hollow shaft 50 attached is positioned. In this state, the setting of the hollow shaft 50 along the direction of the ray vector of the cup, which is an artificial joint, can be reproduced by tightening the screw portions 44 of the disk-shaped holder 40.

  After aligning the hollow shaft 50 in the direction of the normal vector of the cup in this manner, the knurled knob 46 and the slider 52 are loosened as shown in FIG. 12B, and the hollow shaft 50 and the central shaft 53 inside thereof are indicated by XII in the drawing. By arbitrarily moving along the normal vector direction and adjusting the amount of the hollow shaft 50 and the central shaft 53 protruding downward from the flat plate 31 and the guide paper GP12, The distance from the origin CO to the bottom of the acetabulum can be reproduced.

  By tightening the knurled knob 46 and the slider 52 in this state, it is possible to fix the amount of protrusion of the hollow shaft 50 protruding from the acetabular surface to the bottom of the acetabulum along the cup ray vector and the central shaft 53 inside thereof.

(2-1-2. Intraoperative usage)
During the operation, the disk-shaped holder 40 and the hollow shaft 50 are reproduced by sterilizing the disk-shaped holder 40 and the hollow shaft 50. The disk-shaped holder 40 and the hollow shaft 50 reproduce the direction of the cup radiation vector with respect to the acetabular circle and the protruding amount to the bottom of the acetabulum. The point screw portions 49A to 49C at the tips of the pointers 47A to 47C of the disc-shaped holder 40 are placed on the acetabulum edge with respect to the pelvic acetabulum of the patient developed in the above.

  FIG. 13A illustrates the state of positioning at this time. Contact to a total of four points, that is, three points on the edge of the acetabulum and one point on the bottom surface of the acetabulum can be easily confirmed by the output of the contact sensor at each tip.

  When the contact of the four points is confirmed, the direction of the cup ray vector set by the model before the operation can be accurately reproduced as the direction of the hollow shaft 50 even during the operation.

  Thereafter, the center shaft 53 is replaced with a drill and a pilot pin is hit to determine the center. At that time, a semi-cylindrical reamer guide for fixing the hollow shaft 50 is fixed to a pelvis outer edge by a fixing pin.

After completion of drilling, the disk-shaped holder 40 and the hollow shaft 50 are removed from the mortar cover. The piercing at the bottom of the acetabulum indicates the reaming direction, and reaming is advanced along the reamer guide with reference to this. This drilling direction is a reference until the final cup insertion.
FIG. 12B shows a model in a state where the cup 60 is attached to the acetabulum after the reaming.

(2-2. Femoral head side)
Next, a jig for cutting the head and determining the reaming direction of the femur bone marrow for mounting the stem which is an artificial joint on the femur side and the process of using the jig will be described with reference to FIGS.

  FIG. 14 shows an external configuration of a frame body jig 70 that corrects the reaming direction of the femur bone marrow with respect to the cut surface of the femoral head cut at the neck. The frame body jig 70 has a substantially cubic structure in which three side walls 70B to 70D are upright with respect to the bottom surface 70A. In other words, a shape in which an upper part and one side surface of a cube whose outer dimension on one side is 80 [mm] is omitted is adopted.

  A total of four screw holes are formed at each corner so as to form a square with a side of 10 [mm] at the center of the pair of side walls 70B and 70D that face each other. Further, in the side wall 70C sandwiched between the side walls 70B and 70D, a total of two screw holes with a distance of 10 [mm] are formed in the central portion in the vertical direction.

  Two screw holes in each of the side walls 70B and 70D corresponding to the YZ plane of the head coordinate, one in each screw hole in the side wall 70C corresponding to the XZ plane, and one on the bottom surface 70A corresponding to the XY plane. A total of six sharp threaded portions 71a to 71f are attached from the outer surface side toward the inner surface side, and the amount of protrusion of each is adjustable.

  Each of these screw portions 71a to 71f has a sharp tip and a built-in contact sensor, and can accurately detect the presence or absence of contact with the bone head when the bone head is connected after connection.

  In addition, it has a screw portion 72 that stands upright from the bottom surface 70A, and this screw portion 72 is arbitrarily provided along the direction of the arrow XIV in the figure corresponding to the X-axis direction of the bone head coordinates as the bolt 73 rotates. Slide. The axial direction of the threaded portion 72 indicates the Z axis that coincides with the femur bone marrow axial direction.

  FIG. 15A shows a partial external configuration of the osteotomy jig 80 used for femoral head cutting and femur bone marrow direction detection. In FIG. 1A, the osteotomy jig 80 is configured such that a pair of flat plate portions 81 and 82 are integrated via an inclined plate portion 83 and have a predetermined gap. The flat plate-like portion 82 can be separated from the flat plate-like portion 81 side by a separation portion 82a in the vicinity of the inclined plate portion 83 in the drawing.

  Two plate holes 811, 812, 821, and 822 are formed in both of the flat plate portions 81 and 82, and the flat plate portions 81 and 82 can be fixed with pins from the side surfaces of the femoral head. An osteotomy saw is inserted along the gap between the flat plate portions 81 and 82 to cut the femoral head and neck.

  The inclined plate portion 83 has an arc-shaped notch formed at a position offset from the flat plate portions 81 and 82, and is a disk-shaped holder (not shown) that is substantially equivalent to the disk-shaped holder 40 used as the pelvic side shaft. ) Is installed. This disk-shaped holder has substantially the same configuration as the disk-shaped holder 40 except that there are no circumferential pointers 47A to 47C and screw parts 48A to 48C. The bearing also supports a hollow shaft (not shown) in an arbitrary direction, and the angle of the ball bearing can be fixed by tightening the screw portion.

FIG. 15B shows an external configuration of a stem 90 that is installed as an artificial joint after the femoral head is cut off. In the figure, it is inserted and fixed in the axial direction (Z direction) of the femur bone marrow with respect to the femoral head from which the sharp part at the lower end is cut off.

(2-2-1. Adjustment before surgery)
First, the screw 73 of the frame body jig 70 is moved by rotating the bolt 73 to a position in the reaming direction (Z axis) that can be calculated from the position of the nearest point.

  In addition, the protruding amounts of the screw portions 71a to 71f of the bottom surface 70A and the side walls 70B to 70D are adjusted based on the bone head shape obtained by the preoperative plan and the distance to the bone contour of the neck.

  At this time, a paper on which the bone head contour shape is printed in full size from each angle is pasted on the inner surfaces of the bottom surfaces 70A and the side walls 70B to 70D, and the screw portions 71a to 71f are matched to the images. It is good also as what adjusts, visually observing the protrusion amount.

(2-2-2. Intraoperative use)
Hereinafter, handling on the femoral side during the operation will be described with reference to FIGS. 16 to 20.
During the operation, the osteotomy jig 80 is installed on the side of the femoral TB head having a shape as shown in FIG. 16 as shown in FIG.

In this case, a pin is driven into each pin hole 811, 812, 821, 822 so that the gap between the integrally connected flat plate portions 81, 82 is located at the head and neck of the head planned before the operation. As shown in FIG. 17, an osteotomy jig 80 is installed on the front side of the head side.
As described above, the central gap between the integrally connected flat plate portions 81 and 82 becomes the osteotomy surface, and after finishing the bone cutting, the pins of the flat plate portions 81 and 82 to the respective femurs are fixed. The flat plate portions 81 and 82 are separated from the separation portion 82a, and the flat plate portion 81 on the femoral head side is removed with the disc-shaped holder attached.

  As shown in FIG. 18, the extracted bone head and the flat plate-like portion 81 are supported by the frame body jig 70. As described above, in the center of the frame body jig 70, the screw portion 72 indicating the Z axis indicating the femur bone marrow direction is upright, and the Z axis from the tip of the screw from the corresponding wall surface of the frame body jig 70 is arranged. The distance to the screw part 72 shown is adjusted to the distance from the origin to the nearest point calculated by the jig coordinates calculated in the preoperative plan. It arrange | positions so that this thread part 72 may be penetrated with respect to the ball bearing of a disk shaped holder.

  The side walls 70B to 70D of the frame body jig 70 correspond to the jig coordinate system. As described above, the projections of the screw portions 71a to 71f are adjusted to the distances calculated before the operation from the respective surfaces of the side walls 70B to 70D. The amount is set.

  Therefore, as shown in FIG. 19, it positions so that the extracted bone head may contact | connect the front-end | tip of the screw parts 71a-71f adjusted to predetermined length. In this case, since the position and the angle of the ball bearing of the disk-shaped holder penetrated by the screw portion 72 are not fixed, the free movement of the bone head can be realized.

  When contact with the tips of the screw portions 71a to 71f protruding from the three-direction wall surfaces at the bone head and neck is confirmed, the distance from the bottom surface 70A and the side walls 70B to 70D to the bone cortical surface of the bone head is preoperatively. The plan can be reproduced, and the angle of the ball bearing of the disc-shaped holder at the position passes through the origin of the stem in the Z-axis direction of the stem regardless of the position of the cut surface.

  This reference point adjusts two screws from different wall surfaces including the most recent point on the bone head and three screws on different surfaces in the neck, and a contact sensor is laid at each screw tip.

  Therefore, after tightening the screw part of the disk-shaped holder in this state to fix the position and angle of the ball bearing, the plate-shaped part 81 and the disk-shaped holder are removed from the bone head by removing the pins of the pin holes 811 and 812, and again. It connects with the flat part 82 attached to the femur. At this point, since the ball bearing of the disc-shaped holder of the osteotomy jig 80 accurately indicates the bone marrow (Z) direction of the femur, drilling is performed on the ball bearing as shown in FIG. By performing the reaming (over drill) process according to the drill position, the same direction as the preoperative plan can be reproduced, and the stem 90 shown in FIG. 15B can be installed.

  As described above, regarding the hip replacement surgery using the bone shape model by the X-ray CT scanning apparatus and the MRI apparatus, the pelvic acetabular reaming operation and the femur are appropriately reflected in the individual differences of the patient before the operation. The cutting of the bone head and the reaming operation from the cut surface can be accurately determined, and during the operation, a surgical operation that accurately reproduces the content determined before the operation can be performed.

  In addition, the personal computer software for preoperative planning and various jigs used during the operation according to the present embodiment are useful as those that are sufficiently practical not only in large hospitals but also in relatively small general hospitals.

  In addition, this invention is not limited to embodiment mentioned above, In the implementation stage, it can change variously in the range which does not deviate from the summary. In addition, the functions executed in the above-described embodiments may be implemented in appropriate combination as much as possible. The above-described embodiment includes various stages, and various inventions can be extracted by an appropriate combination according to a plurality of disclosed structural requirements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the effect is obtained, a configuration from which the constituent requirements are deleted can be extracted as an invention.

The block diagram which shows the hardware constitutions of the personal computer which installed the preoperative planning program of the hip replacement surgery which concerns on one Embodiment of this invention. The flowchart which shows the processing content of the program for preoperative planning which concerns on the embodiment. The figure which illustrates the preoperative process step by the side of the pelvis acetabulum concerning the embodiment. The figure which illustrates the preoperative process step by the side of the pelvis acetabulum concerning the embodiment. The figure which illustrates the preoperative process step by the side of the pelvis acetabulum concerning the embodiment. The figure which illustrates the preoperative process step by the side of the pelvis acetabulum concerning the embodiment. The figure which illustrates the preoperative process step by the side of the pelvis acetabulum concerning the embodiment. The figure which illustrates the preoperative process step by the side of the pelvis acetabulum concerning the embodiment. The perspective view which shows the external appearance structure of the frame body jig | tool for acetabulum based on the embodiment. The figure which shows the structure of the disk shaped holder and hollow shaft which concern on the same embodiment. The figure which illustrates the guide paper with which the frame body jig | tool for acetabula which concerns on the same embodiment is mounted | worn. The figure which illustrates the setting of the disk-shaped holder and hollow shaft using the frame body jig | tool for acetabulum and guide paper which concern on the embodiment. The figure which shows the contact | abutting to the pelvic acetabulum of the intraoperative disk-shaped holder and hollow shaft based on the preoperative plan which concerns on the same embodiment, and the installed cup (artificial joint). The figure which shows the external appearance structure of the frame body jig | tool for the femoral head which concerns on the same embodiment. The figure which shows the external appearance structure of the osteotomy jig | tool for cutting a femur and stem (artificial joint) which concern on the embodiment. The figure which shows in steps from the cutting | disconnection of the femoral head which concerns on the embodiment to the bone marrow direction detection for stem mounting | wearing. The figure which shows in steps from the cutting | disconnection of the femoral head which concerns on the embodiment to the bone marrow direction detection for stem mounting | wearing. The figure which shows in steps from the cutting | disconnection of the femoral head which concerns on the embodiment to the bone marrow direction detection for stem mounting | wearing. The figure which shows in steps from the cutting | disconnection of the femoral head which concerns on the embodiment to the bone marrow direction detection for stem mounting | wearing. The figure which shows in steps from the cutting | disconnection of the femoral head which concerns on the embodiment to the bone marrow direction detection for stem mounting | wearing.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Personal computer (PC), 11 ... CPU, 12 ... North bridge, 13 ... Main memory, 14 ... Graphic controller, 15 ... Graphic memory, 16 ... South bridge, 17 ... PCI bus, 18 ... Keyboard / mouse, 19 ... Video encoder, 20 ... Hard disk device (HDD), 21 ... Network interface (I / F), 22 ... Multi-disk drive, 30 ... Frame body jig for acetabulum, 31 ... Flat plate, 32 ... Upper bottom surface, 33 ... Lower bottom surface 34 ... Circular hole, 35 ..., 36 ..., 37 ..., 38 ..., 39 ..., 40 ... Disc-shaped holder, 41, 42 ... Circular disc, 43 ... Ball bearing, 44 ... Screw part, 45 ... Outer cylinder part, 46 ... Knurled knob, 47A-47C ... Pointer, 48A-48C ... Screw part, 49A-49C ... Point screw part, 50 ... Empty shaft, 51 ... T-shaped handle, 52 ... Slider, 53 ... Center axis, 60 ... Cup, 70 ... Frame body jig, 70A ... Bottom surface, 70B-70D ... Side wall, 71a-71f ... Screw part, 72 ... Screw , 73 ... bolt, 80 ... osteotomy jig, 81 and 82 ... flat plate part, 82a ... separation part, 83 ... inclined plate part, 90 ... stem, AGP ... graphics interface, FSB ... front side bus, MB ... memory Bus, TB ... femur.

Claims (8)

An image input step for inputting a plurality of two-dimensional tomographic images of the pelvis including the acetabulum;
An image reconstruction step of reconstructing a three-dimensional image of the pelvis including at least the acetabulum from the plurality of images input in the image input step;
From the three-dimensional image of the pelvic acetabulum obtained in the image reconstruction step, an artificial joint determination step for determining a replacement artificial joint and an installation position;
Various parameters used in the reaming operation for embedding the artificial joint in the pelvic acetabulum based on the artificial joint determined in the artificial joint determination step and its installation position and the reference point of the acetabulum in the three-dimensional image. A program for preoperative planning of hip replacement surgery, characterized by causing a computer to execute a parameter determining step to be determined.   The parameter determination step is performed by measuring the distance from the disc formed by the three points of the acetabular edge to the acetabular bottom based on the position coordinates of the three points on the acetabular edge and the normal vector of the artificial joint at the installation position. The preoperative planning program for hip replacement surgery according to claim 1, wherein various parameters including: are determined.   The three points on the acetabular margin are XY including the femoral head center of the pelvic coordinate system in which the pubic joint center is set as the origin in a plane (XZ plane) including the three points of both anterior superior iliac spines and the pubic joint center The total hip replacement surgery according to claim 2, characterized in that two points on the acetabular margin located in a plane and one of the closest points in the Z-axis direction of the pelvic coordinate system on the acetabular margin are also used. Preoperative planning program. An image input step of inputting a plurality of two-dimensional tomographic images of the femur including the hip joint;
An image reconstruction step of reconstructing a three-dimensional image of the femur including at least the hip head from the plurality of images input in the image input step;
An artificial joint determination step for determining an artificial joint to be replaced and an installation position from a three-dimensional image including the femoral head obtained in the image reconstruction step;
Used in bone marrow reaming operation to embed the prosthetic joint after cutting the femoral head and neck based on the prosthetic joint determined in the prosthetic joint determining step and its installation position and the reference point of the femoral head in the three-dimensional image A program for preoperative planning of hip replacement surgery, characterized by causing a computer to execute a parameter determination step for determining various parameters to be performed.   5. The preoperative planning program for artificial hip joint replacement surgery according to claim 4, wherein the parameter determining step determines various parameters indicating the distance and direction of the femoral bone marrow axis with respect to the cut surface of the femoral head and neck. . A hollow shaft portion indicating the reaming axis direction of the pelvic acetabulum;
A disc-shaped holder portion that supports a ball bearing portion that penetrates and supports the hollow shaft portion so as to be rotatable and slidable in a radial direction, and can fix the rotation position and the slide position of the ball bearing portion by fastening a screw portion. When,
For determining the direction of the disk-shaped holder, comprising a holder mounting surface for mounting the disk-shaped holder portion, and first and second paper surface mounting portions for mounting a paper surface at a predetermined distance across the holder mounting surface. An artificial hip joint replacement surgical jig characterized by comprising:   The disk-shaped holder portion includes three indicating members capable of adjusting both a moving position that moves along the circumference and a protruding amount that protrudes outward from the circumference in the radial direction. Item 7. The artificial hip joint replacement jig according to Item 6. A first attachment part having a flat plate-like part attached to the vicinity of the head and neck of the femoral body;
A second mounting portion that is detachably provided on the first mounting portion and has a flat plate-like portion that is mounted on the femoral head at a distance from the flat plate portion of the first mounting portion;
A hollow shaft portion detachably attached to the first and second mounting portions, showing a reaming axis direction with respect to a cut surface obtained by cutting the head and neck of the first and second mounting portions from the gap between the flat plate portions;
A ball bearing portion, which is attached to the second mounting portion and supports the hollow shaft portion so as to penetrate therethrough, is rotatably supported and slidable in a radial direction. A disc-shaped holder that can fix the slide position;
A holding part corresponding to the shape at the time of preoperative planning of the cut femoral head, and the femur holding and holding the femoral head with the discoid holder part and the second attachment part attached to the holding part A hip replacement surgical treatment characterized by comprising a frame body having a correction mechanism for correcting the rotational position and slide position of the ball bearing portion of the disc-shaped holder portion according to the position and direction of the cutting surface of the bone head. Ingredients.

Images