JP2014104195A - Support jig for artificial hip joint acetabular cartridge surgery and method for acquiring preoperative image data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a highly advanced surgery by using a small-scale jig device without depending on a large-scale CT scan apparatus or a large-scale computer.SOLUTION: A support jig (1) for an artificial hip joint acetabular cartridge surgery includes: an alignment shaft (24) that attachably/detachably holds an acetabular cartridge pin (22), the tip end of which is positioned at a central position of the acetabular cartridge (94) of the pelvis (10) and can substitute an acetabular reamer (23) for the acetabular cartridge pin; a first arm (25) that can turn within a first plane (27) and the tip end of which is positioned at a first feature point (P1); and a second arm (26) that can turn within a second plane (29) separated from the first plane by a prescribed distance (r) and being parallel to the first plane, and the tip end of which is positioned at a second feature point (P2). The physical relationship of the positioned first arm and second arm is fixed with respect to the alignment shaft on the basis of the preoperative image data. The support jig is placed on the pelvis of a patient, with the axis line of the alignment shaft matching a normal vector (96), and the acetabular reamer is substituted for the positioned acetabular cartridge pin.

Description

  The present invention relates to a hip prosthesis support tool used in a surgical operation for replacing a hip joint destroyed by a disease or an injury with an artificial hip joint, and a preoperative image data acquisition method.

  The hip joint is the most important joint in the lower limbs, and if there is a malfunction, serious problems occur in daily life including walking. The hip joint is a site that is often destroyed by trauma, and cartilage is degeneratively destroyed by aging, leading to arthropathy.

  As a surgical treatment for hip arthropathy, artificial joint replacement that removes the broken cartilage, inserts an artificial hip joint, and reconstructs the joint function by contact with metal and plastic provides the most stable improvement. Widely implemented as a treatment method.

  The hip prosthesis consists of an acetabular cup and a femoral stem, and the accuracy of the position where the acetabular cup and femoral stem are installed, that is, the position where each bone is extracted, ensures proper operation and durability of the hip prosthesis. A big influence.

  Conventionally, the position of the hip prosthesis has been determined by superimposing a transparent sheet printed with projection contours from the front and side directions on the front and side x-rays of the patient before surgery. It was. However, in this method, there is a problem that the grasp of the bone shape is affected by the X-ray irradiation direction and the position of the patient at the time of imaging and lacks accuracy.

  In recent years, a computer system has been developed in which the bone shape of an X-ray image is image-matched with a 3D model of a bone shape created by CT or MRI, so that the standing bone shape can be grasped in 3D. Yes. A system has been proposed in which a three-dimensional shape model based on CAD data of an artificial joint is called into this computer system so that the size and position of the artificial joint applied to the bone shape and load environment can be determined (for example, Patent Document 1). 2).

  Such a computer system has been put into practical use as a navigation system that can be used not only for preoperative determination of the position of the acetabular cup of an artificial hip joint but also during surgery.

JP 2003-144454 A JP 2004-008707 A

  However, the conventional navigation system as described above has a problem that the operation is complicated, the apparatus itself is large and expensive, and it is difficult to introduce it into an operating room unless it is a large hospital.

  Accordingly, an object of the present invention is to solve the problems of the prior art, determine the installation position of the acetabular cup based on preoperative image data of the pelvis, and then repair a simple structure during the operation. It is an object of the present invention to provide a hip prosthesis acetabular support jig and a preoperative image data acquisition method that support reaming of acetabular holes and intraoperative operations for installing a acetabular cup using a tool.

In order to achieve the above object, an artificial hip acetabular support jig according to the present invention positions an acetabular component of an artificial hip joint on the acetabulum of a patient's pelvis based on preoperative image data of the pelvis. A support jig for hip joint acetabular surgery that supports the surgery to be installed,
A sighting shaft capable of detachably holding a acetabular pin whose tip is positioned at the center position of the pelvis of the pelvis and removably holding the acetabular reamer instead of the positioned acetabular pin;
The first pelvis of the pelvis in the preoperative image data can be swiveled around a first pivot axis perpendicular to the first plane provided on the aiming shaft within a first plane including the axis of the aiming shaft. A first arm whose tip is positioned at the feature point;
In a second plane that is a predetermined distance away from the first plane and parallel to the first plane, and is pivotable about a second pivot axis that is perpendicular to the second plane provided on the aiming shaft; A second arm whose tip is positioned at a second feature point of the pelvis in the preoperative image data;
With
Based on the preoperative image data, the acetabular pin attached to the aiming shaft is made to coincide with the normal line standing at the center position of the acetabular, and the distal end portion of the first arm points to the first feature point. The first arm is positioned with respect to the first pivot axis, and the second arm is positioned with respect to the second pivot axis so that the tip of the second arm points to the second feature point. ,
The positioned first arm and the second arm are fixed in positional relation with respect to the aiming shaft, and the axis of the aiming shaft is set on the patient's pelvis so as to coincide with the normal line. The acetabular reamer is used instead of the acetabular pin.

Further, the preoperative image data is an X-ray source that is arranged so as to intersect the first irradiation surface on which the first tube as an X-ray source is irradiated from the front and the first irradiation surface by a predetermined angle. Using the second irradiation surface on which the two tubes are irradiated from the front, the first tube is applied to the first irradiation surface in a state where the patient is positioned at the first position which is a position facing the first irradiation surface. A first front image obtained by irradiation, a first slope image obtained by irradiating the second irradiation surface with the second tube, and a second position which is a position where the patient faces the second irradiation surface A second front image obtained by irradiating the second irradiation surface with the second tube in a state of being located at a position, and a second slope image obtained by irradiating the first irradiation surface with the first tube. It is obtained by performing predetermined image processing in a predetermined processing means.

Further, the preoperative image data acquisition method according to the present invention is a technique used in an artificial hip acetabular support jig for supporting an operation for positioning and installing a acetabular component of an artificial hip joint on a acetabulum of a patient's pelvis. A method of acquiring previous image data,
The first tube, which is an X-ray source, is arranged to intersect the first irradiation surface irradiated from the front and the first irradiation surface by a predetermined angle, and the second tube, which is an X-ray source, is irradiated from the front. First front image obtained by irradiating the first irradiation surface with the first tube in a state where the second irradiation surface is used and the patient is positioned at the first position where the patient faces the first irradiation surface. And the first slope image obtained by irradiating the second irradiation surface with the second tube, and the second tube in a state where the patient is located at a second position which is a position facing the second irradiation surface. Obtaining a second front image obtained by irradiating the second irradiation surface with a sphere and a second slope image obtained by irradiating the first irradiation surface with the first tube;
Capturing the first front image, the first slope image, the second front image, and the second slope image into a personal computer;
In the first slope image, the right anterior superior iliac spine (ASIS) is imaged so that the position can be specified, and in the second slope image, the left anterior superior iliac spine (ASIS) is imaged so that the position can be specified. The height position of the right anterior superior iliac spine (ASIS) obtained from the first slope image is drawn on the first front image, and the right anterior superior iliac spine (ASIS) is drawn to the first front image. The height position of the left anterior superior iliac spine (ASIS) identified above and obtained from the second slope image is drawn on the second front image, and the left anterior superior iliac spine (ASIS) is 2 The process of specifying on the front image;
In the first front image, the first slope image, the second front image, and the second slope image, a right acetabular position point, a left acetabular position point, and a sciatic unilateral lowest point are identified, and the right acetabulum Paying attention to the shape of an intermediate triangle formed by connecting the lid position point, the left acetabular position point, and the lowest point on the one side of the ischial bone, the first front image, the first slope image, the second front image, and the Identical coordinates representing the first front image, the first slope image, the second front image, and the second slope image based on the fact that each of the intermediate triangles in the second slope image is the same. An intermediate coordinate system is introduced, and the information in the intermediate coordinate system is used, and the left anterior superior iliac spine (ASIS) in the second front image and the second slope image is represented by the first front image and the first image. While specifying on one slope image, the first positive And specifying the right anterior superior iliac spines in the image and the first inclined surface image (ASIS) on the second front image and the second inclined surface image,
A first image set including the first front image and the first slope image in which the right anterior superior iliac spine (ASIS) and the left anterior superior iliac spine (ASIS) are specified; One image set suitable for surgery among the second front image in which osteophyte (ASIS) and the left anterior superior iliac spine (ASIS) are specified and the second image set including the second slope image Selecting as a surgical image set;
Referring to the front image and the slope image in the surgical image set, assuming that the concave portion of the acetabulum to be operated is filled with a hemispherical cup body, the diameter size of the hemispherical cup body and the contour circle of the hemispherical cup body A normal vector connecting the center of the hemispherical cup body and the bottom vertex of the hemispherical cup body, and selecting the acetabular component corresponding to the diameter size,
Referring to the front image and the slope image in the surgical image set, the ridge line of the iliac crest on the same side as the first feature point is obtained, and the intersection of the ridge line and the second plane is used as the second feature point. And a step of specifying an iliac crest point.

  According to the configuration of the present invention, it is possible to simply configure a support jig during an artificial hip acetabulum, without depending on a large-scale CT scanning device, a large-sized computer, etc. By using a personal computer, it is possible to perform an operation with high positional accuracy.

Explanatory drawing of the artificial hip joint used by artificial hip joint replacement surgery. The side view which shows the support jig | tool during artificial hip joint acetabulum operation by one Embodiment of this invention. The top view which shows the support jig | tool during an artificial hip acetabulum operation corresponding to FIG. Sectional drawing which shows the holder for acetabular pins in the support jig | tool during an artificial hip acetabulum operation. The longitudinal cross-sectional view corresponding to FIG. It is a side view which shows the holder for acetabular reamers in the support jig | tool during artificial hip acetabulum surgery, (a) shows the state before attaching an acetabular reamer to the holder for acetabular pins, (b) The state which attached the acetabular reamer to the holder for acetabular pins is shown. The figure which shows attaching and using a front-end | tip bar at the front-end | tip of a 1st arm and a 2nd arm. The perspective view which shows the support jig | tool during an artificial hip joint acetabulum operation to which the holder for acetabular pins was attached. The figure which shows the 1st irradiation surface and the 2nd irradiation surface which are arrange | positioned mutually and used in order to obtain the preoperative image data of a pelvis. The figure which shows the state in which the patient was located in FIG. In order to obtain preoperative image data of the pelvis, the patient is positioned in two ways: a first position that is the position facing the first irradiation surface and a second position that is the position facing the second irradiation surface. Figure. A first front image (a) obtained by irradiating the first irradiation surface in a state of being located at the first position which is a position opposite to the first irradiation surface, and a first slope obtained by irradiating the second irradiation surface. The figure which shows an image (b). A second front image (a) obtained by irradiating the second irradiation surface in a state of being located at the second position, which is a position facing the second irradiation surface, and a second slope obtained by irradiating the first irradiation surface. The figure which shows an image (b). The figure which shows the method of specifying the right frontal superior iliac spine (ASIS) in a 1st slope image (b) in a 1st front image (a). The figure which shows the method of specifying the left front superior iliac spine (ASIS) in a 2nd front image (a) in a 2nd slope image (b). It shows that the left anterior superior iliac spine (ASIS) specified from the second slope image and the second front image is specified in the first slope image (b) and the first front image (a) using the intermediate coordinate system. Figure. It shows that the right anterior superior iliac spine (ASIS) specified from the first slope image and the first front image is specified in the second slope image (b) and the second front image (a) using the intermediate coordinate system. Figure. The figure explaining the iliac crest approximate curve of the general insertion outline circle of an acetabulum, and an iliac crest. The hemispherical cup body in the cup model will be described. The figure which shows a 3rd arm. The figure which shows typically the relationship between the 1st arm and the 2nd arm, the right anterior superior iliac spine (ASIS), the hemispherical cup body, the normal vector, and the iliac crest approximation curve in the assist jig during the artificial hip acetabulum. On the acetabulum on the left leg side, the aiming fixed frame, the first arm, the second arm, the hemispheric cup body, the normal vector, the first feature point P1, the second feature point P2, and the third feature point P3 are schematically displayed. FIG.

  Hereinafter, an embodiment of an artificial hip acetabular support jig according to the present invention will be described with reference to the accompanying drawings.

  First, an artificial hip joint replacement operation will be described with reference to FIG. FIG. 1 shows a hip prosthesis used in hip replacement surgery. In FIG. 1, reference numeral 10 indicates the pelvis, and reference numeral 12 indicates the femur. The artificial hip joint includes a femoral stem 14 joined to the femur 12, a hemispherical acetabular component 16 embedded in the pelvic acetabulum, and a head attached to the femoral stem 14 and tiltable to the acetabular component 16. 18. The acetabular component 16 includes a metal outer shell 19 and a resin inner cup 20 that receives the head 18.

  In the hip replacement surgery, the cartilage is excised from the pelvic acetabulum, and the bone of the acetabulum is cut to form a hemispherical hole, and the acetabular component 16 is attached to the hole. On the other hand, the femoral stem 14 is inserted into the femur 12 after extracting the femoral head.

Next, the support jig 1 during the artificial hip acetabulum operation according to this embodiment will be described.
The hip prosthesis acetabular support jig 1 supports the operation of positioning and installing the acetabular component of the hip prosthesis on the acetabulum of the patient's pelvis based on the preoperative image data of the pelvis acquired in advance. .

  The assisting jig 1 during the hip prosthesis acetabulum can be detachably held by attaching a acetabular pin 22 whose tip is positioned at the center position of the pelvis of the pelvis and can be replaced with the acetabulum instead of the positioned acetabular pin 22. An aiming shaft 24 that can replace the mortar reamer 23, a first arm 25 whose lower end is positioned at the first feature point P1 of the pelvis in the preoperative image data, and a second feature point P2 of the pelvis in the preoperative image data And a second arm 26 whose lower end is positioned.

  The first arm 25 can turn around a first turning shaft 28 provided on the aiming shaft 24 and perpendicular to the first plane 27 in a first plane 27 including the axis 24 a of the aiming shaft 24. The second arm 26 is in a second plane 29 parallel to the first plane 7 that is separated from the first plane 27 by a predetermined distance r, and is a second pivot 30 that is perpendicular to the second plane 29 provided on the aiming shaft 24. Can be swiveled around. The first plane 27 and the second plane 29 are displayed perpendicular to the paper surface in FIG.

  The aiming shaft 24 includes a semi-cylindrical aiming shaft main body 31 having an axis line 24a, and a semi-ring-shaped aiming fixing frame 32 attached to the upper part of the aiming shaft main body 31 coaxially with the axis line 24a. The upper end portion of the aiming shaft main body 31 is formed integrally with the inner ring of the aiming fixing frame 32.

  The aiming fixed frame 32 is provided with projections 32a, 32b, and 32c at an angular position of 90 degrees with respect to each other, the first pivot shaft 28 is provided on the projection 32a, and the second pivot shaft 28 is provided on the projection 32b. It has been. As will be described later, when the acetabulum is weakened and the center position is not clear, the protrusion 32c is a third arm 106 whose lower end is positioned at the third feature point of the pelvis in the preoperative image data (see FIG. 22). ) To the aiming shaft 24.

  An acetabular pin holder 34 for attaching the acetabular pin 22 to the aiming shaft 24 and an acetabular reamer holder 36 for attaching the acetabular reamer 22 to the aiming shaft 24 are attached to the aiming shaft main body 31. Is possible.

  As shown in FIGS. 4 and 5, the acetabular pin holder 34 includes a block portion 38, a set screw 39, and a cylindrical portion 40. A pore body 41 is attached to the tip of the cylindrical portion 40 so that the axis of the mortar pin 22 coincides with the axis 24a of the aiming shaft and is easily positioned and held. The block portion 38 is attracted to the head side of the set screw 39 by the set screw 39, and the cylindrical portion 40 and the pore body 41 are attached to the aiming shaft main body 31 by the opposing set screws 39a and 39b. The mortar pin 22 is inserted from above the cylindrical portion 40. Further, a handle bar 42 is attached to the cylindrical portion 40, and the acetabular pin 22 held by the aiming shaft 24 is positioned at the center position of the acetabulum to be operated by operating the handle bar 42 by hand. Becomes easier.

Next, the acetabular reamer holder 36 will be described with reference to FIG.
The acetabular reamer holder 36 includes a semi-cylindrical portion 44 attached to the inside of the aiming shaft main body 31 and the set screw 39 for fixing the semi-cylindrical portion 44 to the inner side of the aiming shaft main body 31. The semi-cylindrical portion 44 is attracted to the head side of the set screw 39 by a set screw 39 and fixed to the aiming shaft main body 31.

The acetabular reamer holder 36 is used as follows.
Based on the preoperative image data, the acetabular pin attached to the aiming shaft 24 via the acetabular pin holder 34 is made to coincide with the normal line standing at the center position of the acetabulum, and the distal end portion of the first arm 25 is The first arm 25 is positioned with respect to the first pivot axis 28 so as to point to the one feature point P1, and the second arm 26 is moved to the second pivot axis so that the tip of the second arm 26 points to the second feature point P2. Position with respect to 30. The positional relationship between the positioned first arm 25 and second arm 26 is fixed with respect to the aiming shaft 24. Here, the normal line is specified by, for example, a normal vector described later. Next, the axis 24a of the aiming shaft 24 is set on the patient's pelvis so as to coincide with the normal line. In this state, the acetabular pin holder 34 attached to the aiming shaft main body 31 is replaced with the acetabular reamer holder 36 and replaced with the acetabular reamer 23 instead of the positioned acetabular pin 22.

  The acetabular reamer 23 is composed of a grind portion 23a at the distal end and a shaft portion 23b positioned at the upper portion of the grind portion 23a. The size of the grind portion 23a is selected so as to correspond to the size of a hemispherical cup body obtained by a cup model described later. FIG. 6A shows a state where the acetabular reamer 23 is removed from the acetabular reamer holder 36 before the acetabular reamer 23 is attached to the acetabular reamer holder 36. FIG. 6B shows a state where the shaft portion 23 b of the acetabular reamer 23 is brought into contact with the semi-cylindrical portion 44 of the acetabular reamer holder 36 and the acetabular reamer 23 is attached to the acetabular reamer holder 36. Indicates.

  In order to cut the acetabulum to be operated in the desired exact size and direction, the acetabulum is shaved at once with the acetabular reamer 23 replaced in place of the positioned acetabular pin 22. Instead, the acetabulum is shaved little by little while replacing the acetabular pin 22 and the acetabular reamer 23 alternately while confirming the proper position. For this reason, the semi-cylindrical portion 44 of the acetabular pin holder 34 is formed in a semi-cylindrical shape, so that the shaft portion 23b of the acetabular reamer 23 can be easily and frequently attached and detached. It is like that.

  Next, the auxiliary link 48 will be described with reference to FIG. 2, FIG. 3, FIG. The auxiliary link 48 allows the first arm 25 and the second arm 26 to pivot about the first pivot axis 28 and the second pivot axis 30 and allows the first arm 25 and the second arm 28 to be fixed to each other. To do.

  The auxiliary link 48 includes a first link 50 formed with a groove 50a, a second link 51 formed with a groove 51a, a first screw part 52, a second screw part 53, and a third screw part 54. The first arm 25 and the second arm 26 are provided with groove portions 25a and 26a, respectively.

  The first link 50 is attached so as to be rotatable around a turning shaft 55 attached to the lower part of the aiming shaft main body 31. The turning shaft 55 is provided perpendicular to the first plane 27 and is located in parallel with the first turning shaft 28. The second link 51 is spanned between the first screw portion 52 and the second screw portion 53.

  The first screw part 52 is attached at one end of the second link 51 through the groove part 26a and the groove part 51a, and holds one end of the second link 51 slidably in the groove part 26a of the second arm 26.

  The second screw portion 53 and the third screw portion 53 are connected with a shaft rod 56 interposed between the first link 50 and the second link 51. The second screw portion 53 and the shaft rod 56 slidably connect the first link 50 and the second link 51 to each other via the groove portion 50a and the groove portion 51a. The third screw portion 54 and the shaft rod 56 slidably connect the first link 50 and the first arm 25 to each other via the groove portion 50a and the groove portion 25a.

  After the first arm 25 and the second arm 28 are positioned based on the preoperative image data, first, the turning operation of the first turning shaft 28 and the second turning shaft 30 is tightened with a pin attached to each turning shaft. And fix. In this case, the first link 50 and the second link 51 of the auxiliary link 48 are slidably connected to the first arm 25 and the second arm 28, so that the first arm 25 and the second arm 28 are connected to each other. There is no problem in the turning operation for positioning. Then, after the turning operation of the first turning shaft 28 and the second turning shaft 30 is fixed by fastening the pin attached to each turning shaft, the first screw portion 52, the second screw portion 53, and the third screw portion 54 are attached. By tightening, the first arm 25 and the second arm 28 are more firmly fixed at the positioning positions.

  Further, in the actual positioning of the first arm 25 and the second arm 28, as shown in FIG. 7, a narrow tip-shaped bar 61 is attached to the hole at the lower end of the main body of the first arm 25. Then, a thin tip bar 62 having a dogleg shape is attached to the hole at the lower end of the main body of the second arm 26. The tip 61 a of the tip bar 61 corresponds to the tip of the first arm 25, and the tip 62 a of the tip bar 62 corresponds to the tip of the second arm 26.

Next, with reference to FIGS. 9 to 20, preoperative image data on which the assisting jig 1 during the hip prosthesis is operated will be described.
What is characteristic in the present invention is that high-level surgery can be performed by using a small-sized jig device and a personal computer without depending on a large-scale CT scanning device or a large-sized computer. .

  As shown in FIG. 9, FIG. 10, etc., in order to acquire preoperative image data, the first tube 71, the second tube 72, and the first tube 71, which are X-ray sources, are irradiated from the front. A first irradiation surface 73 and a second irradiation surface 74 on which the second tube 72 is irradiated from the front are also used. The second irradiation surface 74 is disposed so as to intersect the first irradiation surface 73 by a predetermined angle, for example, an angle of 120 degrees.

  The first irradiation surface 73 and the second tube 72 are provided with two grid plates 75 and 76 at an interval. The patient 76 is positioned between the grid plate 75 and the grid plate 76 with the back facing the first irradiation surface 73 and the second tube 72. In the grid plates 75 and 76, grid matrices 75a and 76a capable of imaging X-rays arranged in a grid are arranged, and the grid matrices 75a and 76a of the grid plates 75 and 76 arranged in the front and back are pelvis. By referring to the images together, it is possible to calibrate the deviation relationship between the irradiation direction of the first tube 71 and the second tube 72 as the X-ray source and the posture of the patient 77 as necessary.

  In a state where the patient 77 is positioned at the first position 78 that is the position facing the first irradiation surface 73, the first tube 71 irradiates the first irradiation surface 73 to obtain the first front image 81 and the second tube. A first slope image 82 is obtained by irradiating the second irradiation surface 74 with a sphere 72. In a state where the patient 77 is positioned at the second position 79 which is the position facing the second irradiation surface 74, the second tube 72 irradiates the second irradiation surface 74 to obtain the second front image 83 and the first tube. A first inclined surface 73 is irradiated with a sphere 71 to obtain a second slope image 74.

  The first front image 81 and the first slope image 82 are paired as images of the same posture of the patient 77 taken from the direction of about 60 degrees, respectively. Similarly, the second front image 83 and the second slope image 84 are taken. Pair with. Small circular points in the image are grid matrices 75a and 76a.

  The first front image 81, the first slope image 82, the second front image 83, and the second slope image 84 are taken into a personal computer as predetermined processing means, and predetermined image processing is performed in the personal computer. One piece of three-dimensional information is given by synthesizing the data corresponding to each other by the pair of the first front image 81 and the first slope image 82. Similarly, one three-dimensional information is given by a pair of the second front image 83 and the second slope image 84.

  In the first slope image 82 shown in FIG. 12, the right anterior superior iliac spine (ASIS) 85 on the right leg side is captured as the upper left corner of the pelvis so that the position can be specified. This is because the right anterior superior iliac spine (ASIS) 85 is positioned at the upper corner of the pelvis when the patient 77 is positioned at the first position 78 and irradiates the second irradiation surface 74 with the second tube 72. It is. However, in the first front image 81, since the right anterior superior iliac spine (ASIS) 85 is not imaged so as to be positioned at the upper corner of the pelvis, the right anterior superior iliac spine (ASIS) 85 is uniquely defined. Not located.

  Similarly, in the second slope image 84 shown in FIG. 13, the left anterior superior iliac spine (ASIS) 86 is imaged so that the position can be specified as the upper right corner of the pelvis.

Next, referring to FIG. 14, the position of the right anterior superior iliac spine (ASIS) 85 in the first front image 81 with reference to the information of the first slope image 82 will be described.
While comparing the first slope image 82 and the first front image 81, paying attention to the height position of the right anterior superior iliac spine (ASIS) 85 specified by the first slope image 82, A height straight line 87 corresponding to the height position of the anterior superior iliac spine (ASIS) 85 is drawn. The intersection of the height straight line 87 and the edge part of the pelvis is obtained with reference to medical knowledge about the pelvis. It has been confirmed that this intersection is the right anterior superior iliac spine (ASIS) 85 in the first front image 81, and this intersection is identified as the right anterior superior iliac spine (ASIS) 85 in the first front image 81. Is done.

  Similarly, in FIG. 15, the second slope image 84 and the second front image 83 are compared, and attention is paid to the height position of the left anterior superior iliac spine (ASIS) 86 specified by the second slope image 84. In the second front image 83, a height straight line 88 corresponding to the height position of the left anterior superior iliac spine (ASIS) 86 is drawn, and the intersection of the height straight line 88 and the edge portion of the pelvis in the second front image 83. Identified as the left anterior superior iliac spine (ASIS) 86.

  Next, referring to FIG. 16 and FIG. 17, a first image set consisting of a first front image 81 and a first slope image 82, and a second image consisting of a second front image 83 and a second slope image 84. A description will be given of the common use of coordinates for pairs.

  In the first front image 81, the first slope image 82, the second front image 83, and the second slope image 84, the right acetabulum position point 91, the left acetabulum position point 92, and the sciatic bone one side lowest point 93 are specified. As the acetabular position point 91a of the right acetabulum 91 and the acetabular position point 92a of the left acetabulum 92, for example, the center position of the bottom of each acetabulum is adopted, and as the lowermost point 93 on the one side of the sciatic bone, for example, the right one Alternatively, the right acetabular position point 91a and the left acetabular position point 92a are not limited to the center position as long as they can be uniquely identified. Attention is paid to the shape of an intermediate triangle 94 formed by connecting the right acetabular position point 91a, the left acetabular position point 92a, and the ischial bone one side lowest point 93. In FIGS. 16 and 17, the right acetabular position point 91a and the left acetabular position point 92a appear to be located on the head of the bone but are located on the acetabulum.

  The intermediate triangles 94 in the first front image 81, the first slope image 82, the second front image 83, and the second slope image 84 are attributed to the same patient 77 and are therefore identical to each other. Therefore, a known image such as coordinate conversion is performed on an intermediate coordinate system, which is the same coordinate system representing the first front image 81, the first slope image 82, the second front image 83, and the second slope image 84 on a personal computer. Introduced using processing technology.

  Then, using the information in the intermediate coordinate system, as shown in FIG. 16, the first front image 81 and the first slope image of the left anterior superior iliac spine (ASIS) 86 in the second front image 83 and the second slope image 84, respectively. 82 is specified. Further, as shown in FIG. 17, the right anterior superior iliac spine (ASIS) 85 in the first front image 81 and the first slope image 82 is specified on the second front image 83 and the second slope image 84.

  In the application of the intermediate coordinate system described above, the left anterior superior iliac spine (ASIS) 86 in the second front image 83 and the second slope image 84 is specified on the first front image 81 and the first slope image 82. The positional accuracy in specifying the right anterior superior iliac spine (ASIS) 85 in the first front image 81 and the first slope image 82 on the second front image 83 and the second slope image 84 is about 1.9 mm. It was confirmed that this is possible within an error range of about 3.0 mm.

  FIG. 16 shows a first image set including a first front image 81 and a first slope image 82 in which a right anterior superior iliac spine (ASIS) 85 and a left anterior superior iliac spine (ASIS) 86 are identified. FIG. 17 shows a second image set including a second front image 83 and a second slope image 84 in which the right anterior superior iliac spine (ASIS) 85 and the left anterior superior iliac spine (ASIS) 86 are identified. It is shown. In the operation, one of the first image set and the second image set, which is more suitable for the operation, for example, one that has been captured more clearly, is selected.

  Here, it is assumed that the acetabulum to be operated is on the right leg side, and the first image set including the first front image 81 and the first slope image 82 is used as an example of the surgical image set.

Next, the cup model will be described with reference to FIGS. 18 and 19.
In the cup model, it is assumed that the concave portion of the acetabulum to be operated is filled with the hemispherical cup body 94 with reference to the front image and the slope image in the surgical image set. Then, the diameter size of the hemispherical cup body 94 and the normal vector 96 connecting the center 94a of the outline circle of the hemispherical cup body 94 and the bottom vertex 94b of the hemispherical cup body 94 are obtained, and the acetabular component corresponding to the diameter size is obtained. 16 is selected.

  For this purpose, the surgeon observes the size and direction of the right acetabulum 91 to be operated in the first front image 81 and the first slope image 82 constituting the first image set adopted as the surgical image set, The acetabular component 16 to be used for the operation will be determined.

  For this reason, in the cup model, the concave portion of the right acetabulum 91 to be operated is assumed as a hemisphere. The approximate insertion contour circle 92 of this hemisphere is obtained by roughly inserting the contour curve of the concave portion of the right acetabulum 91. When the approximate insertion contour circle 93 is roughly determined, a hemispherical cup body 94 of a hemispherical size approximately the same size as the hemisphere having the approximate insertion contour circle 93 is introduced on the screen. The hemispherical cup body 94 is positioned on the screen by trial and error with respect to the concave portion of the right acetabulum 91 to be operated, and finally, the contour circle 95 and the normal vector 96 of the hemispherical cup body 94 are determined. The diameter of the contour circle 95 corresponds to the size of the hemispherical cup body 94. The normal vector 96 is determined as a direction connecting the center 95 a of the contour circle 95 of the hemispherical cup body 94 and the bottom vertex 94 a of the hemispherical cup body 94. Determining the normal vector 96 determines the outer opening angle, the front opening angle, and the position of the hemispherical acetabular component 16 or the femur 12 embedded in the pelvic acetabulum. The bottom vertex 94a of the hemispherical cup body 94 ideally matches the center position of the right acetabulum 91.

  The acetabular pin 22 with the normal vector 96 attached to the aiming shaft 24 is adopted as a normal to stand at the center position of the acetabulum 91, and the axis 24 a of the aiming shaft 24 is made coincident with the normal vector 96 to the patient's pelvis. The support jig 1 is installed during the artificial hip acetabulum.

  Next, with reference to FIG. 18, obtaining the ridge line of the iliac crest point 100 iliac crest 98 in order to identify the second feature point will be described.

  Focusing on the iliac crest 98 in the first front image 81 and the first slope image 82, the contour shape of the iliac crest 98 is digitized as a plurality of discretely distributed points. An iliac crest approximation curve 99 is obtained from a plurality of discretely distributed points by a cubic spline approximation.

  The right anterior iliac spine (ASIS) 85 is used as the first feature point, and the right iliac crest point 100 on the same side as the first feature point is the second feature point during the positioned hip prosthesis This corresponds to the intersection with the second plane 29 in the support jig 1.

  As shown in FIG. 3, the distance between the first plane 27 and the second plane 29 is a predetermined distance r, and the predetermined distance r is selected to be about 4 cm for a standard person. The distance between the right iliac crest point 100 on the same side as the first feature point as the second feature point and the first feature point is a predetermined distance r, and by setting the predetermined distance r to about 4 cm, It becomes possible to set the iliac crest point 100 on the bone crest approximate curve 99.

Next, the third arm 106 will be described with reference to FIG.
When the third arm cannot clearly grasp the center position of the acetabulum, the lower end of the third arm is positioned at the third feature point P3 of the pelvis 10 in the preoperative image data. The third arm 106 is attached to the protrusion 32c of the aiming fixing frame 32 shown in FIG. The third arm 106 is attached so that the projection 32c of the aiming fixing frame 32 is sandwiched by the attachment portion 106a at the upper end of the third arm 106.

  In the present embodiment, since the third arm 106 can be attached to the aiming fixing frame 32 as necessary, even when the center position of the acetabulum cannot be clearly grasped, It becomes possible to accurately position the support jig 1.

  21 shows the first arm 25 and the second arm 26, the right anterior superior iliac spine (ASIS) 85, the hemispherical cup body 94, the normal vector 96, and the iliac crest approximation in the assisting jig 1 during the hip prosthesis. An example of the relationship of the curve 99 is typically shown. In FIG. 21, the mounting positions of the first arm 25 and the second arm 26 with respect to the aiming fixing frame 32 are different from those shown in FIG.

  FIG. 22 is a schematic view of the aiming fixing frame 32, the first arm 25, the second arm 26, the hemispherical cup body 94, the normal vector 96, the first feature point P1, and the second feature point P2. The relationship with the 3rd feature point P3 is shown typically.

  When the left acetabulum 104 is a surgical target, for example, the left anterior superior iliac spine (ASIS) 86 corresponds to the first feature point P1, and the left iliac crest point on the left iliac ridge line 101 is It corresponds to the second feature point P2, and the right anterior superior iliac spine (ASIS) 85 corresponds to the third feature point P3.

  In FIG. 22, when the appropriate hemispherical cup body 94 is determined, the corresponding acetabular component 16 is selected. Then, the acetabular reamer holder 36 is attached to the aiming shaft body 31 with the first arm 25 and the second arm 26 positioned. The acetabular reamer 23 having the grind portion 23 a corresponding to the selected acetabular component 16 is attached to the acetabular reamer holder 36, and the acetabulum is processed by the acetabular reamer 23. The selected acetabular component 16 is placed on the machined acetabulum.

  As described above, according to the embodiment of the present invention, the artificial hip acetabular support jig 1 mainly includes the aiming shaft 24, the first arm 25, and the second arm 26, and can be simply configured. In addition, without depending on a large-scale CT scanning device, a large computer, or the like, it is possible to perform an operation with high positional accuracy by using a small-sized jig device and known image processing in a personal computer.

10 pelvis 16 acetabular component 22 acetabular pin 23 acetabular reamer 24 aiming shaft 24a axis 25 first arm 26 second arm 27 first plane 28 first pivot axis 29 second plane 30 second pivot axis 31 aiming shaft body 32 Aiming fixed frame 34 Acetabular pin holder 36 Acetabular reamer holder 48 Auxiliary link 71 First tube 72 Second tube 73 First irradiation surface 74 Second irradiation surface 81 First front image 82 First slope image 83 Second front image 84 Second slope image 85 Right anterior superior iliac spine (ASIS)
86 Left anterior superior iliac spine (ASIS)
92 outline contour circle 94 hemispherical cup body 96 normal vector 106 third arm P1 first feature point P2 second feature point P3 third feature point

Claims (21)

A hip prosthesis acetabular support jig for assisting in the operation of positioning and setting the acetabular component of the hip prosthesis on the acetabulum of the patient's pelvis based on preoperative image data of the pelvis,
A sighting shaft capable of detachably holding a acetabular pin whose tip is positioned at the center position of the pelvis of the pelvis and removably holding the acetabular reamer instead of the positioned acetabular pin;
The first pelvis of the pelvis in the preoperative image data can be swiveled around a first pivot axis perpendicular to the first plane provided on the aiming shaft within a first plane including the axis of the aiming shaft. A first arm whose tip is positioned at the feature point;
In a second plane that is a predetermined distance away from the first plane and parallel to the first plane, and is pivotable about a second pivot axis that is perpendicular to the second plane provided on the aiming shaft; A second arm whose tip is positioned at a second feature point of the pelvis in the preoperative image data;
With
Based on the preoperative image data, the acetabular pin attached to the aiming shaft is made to coincide with the normal line standing at the center position of the acetabular, and the distal end portion of the first arm points to the first feature point. The first arm is positioned with respect to the first pivot axis, and the second arm is positioned with respect to the second pivot axis so that the tip of the second arm points to the second feature point. ,
The positioned first arm and the second arm are fixed in positional relation with respect to the aiming shaft, and the axis of the aiming shaft is set on the patient's pelvis so as to coincide with the normal line. An artificial hip acetabular support jig which is replaced with an acetabular reamer instead of a acetabular pin. 2. The hip acetabular surgery according to claim 1, wherein the aiming shaft includes an aiming shaft main body having the axis, and an aiming fixing frame coaxially attached to the axis of the aiming shaft main body. Support jig. 3. The artificial hip acetabular cap according to claim 2, wherein the first pivot axis and the second pivot axis are provided on the aiming fixing frame at an angle of 90 degrees with respect to the axis. Intraoperative support jig. A acetabular pin holder for attaching the acetabular pin to the aiming shaft and an acetabular reamer holder for attaching the acetabular reamer to the aiming shaft can be attached to the aiming shaft body. The artificial hip acetabular surgery support jig according to claim 2, wherein the support jig is used. A third arm whose lower end is positioned at a third feature point of the pelvis in the preoperative image data can be attached to the aiming fixing frame when the center position of the acetabulum cannot be clearly grasped. The support jig for artificial hip joint acetabulum surgery according to claim 2. An auxiliary link is provided that allows the first arm and the second arm to pivot about the first pivot axis and the second pivot axis, and allows the first arm and the second arm to be fixed to each other. The assisting jig for an artificial hip joint acetabulum according to claim 1. The first feature point is a surgical target side anterior superior iliac spine (ASIS) of a pair of left and right anterior superior iliac spines (ASIS), or a healthy anterior superior iliac spine (ASIS) on the opposite side, 2. The artificial hip acetabular support according to claim 1, wherein the second feature point is an iliac ridge point that is one point on a ridge line of one iliac ridge of a pair of left and right iliac ridges. jig. The hip acetabular support treatment according to claim 8, wherein the iliac crest is an intersection of the ridge line of the iliac crest on the same side as the first feature point and the second plane. Ingredients. The artificial hip acetabular support jig according to claim 5, wherein the third feature point is an anterior superior iliac spine (ASIS) opposite to the first feature point. The preoperative image data is a second tube that is an X-ray source that is arranged so as to intersect the first irradiation surface irradiated from the front by a first tube that is an X-ray source and a predetermined angle with respect to the first irradiation surface. Using the second irradiation surface on which the sphere is irradiated from the front, the first irradiation surface is irradiated with the first tube in a state where the patient is positioned at the first position which is a position facing the first irradiation surface. The first front image obtained in this manner, the first slope image obtained by irradiating the second irradiation surface with the second tube, and the second position where the patient faces the second irradiation surface. In this state, a second front image obtained by irradiating the second irradiation surface with the second tube and a second slope image obtained by irradiating the first irradiation surface with the first tube are predetermined. 2. The artificial hip acetabular support jig according to claim 1, which is obtained by performing predetermined image processing in a processing means. The predetermined processing means includes a personal computer that takes in the first front image, the first slope image, the second front image, and the second slope image and performs the predetermined image processing. 10. A support jig for artificial hip acetabular surgery as described in 10. In the first slope image, the right anterior superior iliac spine (ASIS) is imaged so that the position can be specified, and in the second slope image, the left anterior superior iliac spine (ASIS) is imaged so that the position can be specified. The artificial hip acetabular surgery support jig according to claim 10, wherein The height position of the right anterior superior iliac spine (ASIS) obtained from the first slope image is drawn on the first front image, and the right anterior superior iliac spine (ASIS) is drawn on the first front image. The height position of the left anterior superior iliac spine (ASIS) obtained from the second slope image is identified on the second front image, and the left anterior superior iliac spine (ASIS) is drawn to the second front surface. The support jig for artificial hip joint acetabulum surgery according to claim 12, which is specified on an image. In the first front image, the first slope image, the second front image, and the second slope image, a right acetabular position point, a left acetabular position point, and a sciatic unilateral lowest point are identified, and the right acetabulum Pay attention to the shape of the intermediate triangle formed by connecting the lid position point, the left acetabular position point, and the lower point of the ischial bone side,
The first front image and the first slope image based on the fact that the intermediate triangles in the first front image, the first slope image, the second front image, and the second slope image are the same. And introducing an intermediate coordinate system that is the same coordinate system representing the second front image and the second slope image,
Using the information in the intermediate coordinate system, the left anterior superior iliac spine (ASIS) in the second front image and the second slope image is specified on the first front image and the first slope image, and The artificial hip joint according to claim 12, wherein the right anterior superior iliac spine (ASIS) in the first front image and the first slope image is specified on the second front image and the second slope image. Support jig during acetabular surgery. A first image set including the first front image and the first slope image in which the right anterior superior iliac spine (ASIS) and the left anterior superior iliac spine (ASIS) are specified; One image set suitable for surgery among the second front image in which osteophyte (ASIS) and the left anterior superior iliac spine (ASIS) are specified and the second image set including the second slope image 15 is selected as a surgical image set, and the artificial hip acetabular support jig is supported according to claim 14. Referring to the front image and the slope image in the surgical image set, assuming that the concave portion of the acetabulum to be operated is filled with a hemispherical cup body, the diameter size of the hemispherical cup body and the contour circle of the hemispherical cup body The hip vector acetabulum according to claim 15, wherein a normal vector connecting a center of the hemisphere cup and a bottom vertex of the hemispherical cup body is obtained, and the acetabular component corresponding to the diameter size is selected. Support jig. Referring to the front image and the slope image in the surgical image set, the ridge line of the iliac crest on the same side as the first feature point is obtained, and the intersection of the ridge line and the second plane is used as the second feature point. The iliac crest point is specified, and the artificial hip acetabular support jig is supported according to claim 15. 17. The hip acetabular support during surgery according to claim 16, wherein the normal vector is adopted as the normal, and the axis of the aiming shaft is set on the pelvis of a patient so as to coincide with the normal vector. jig. A method for acquiring preoperative image data to be used for a hip prosthesis acetabular support jig for assisting in the operation of positioning and installing the acetabular component of the hip prosthesis on the acetabulum of the patient's pelvis,
The first tube, which is an X-ray source, is arranged to intersect the first irradiation surface irradiated from the front and the first irradiation surface by a predetermined angle, and the second tube, which is an X-ray source, is irradiated from the front. First front image obtained by irradiating the first irradiation surface with the first tube in a state where the second irradiation surface is used and the patient is positioned at the first position where the patient faces the first irradiation surface. And the first slope image obtained by irradiating the second irradiation surface with the second tube, and the second tube in a state where the patient is located at a second position which is a position facing the second irradiation surface. Obtaining a second front image obtained by irradiating the second irradiation surface with a sphere and a second slope image obtained by irradiating the first irradiation surface with the first tube;
Capturing the first front image, the first slope image, the second front image, and the second slope image into a personal computer;
In the first slope image, the right anterior superior iliac spine (ASIS) is imaged so that the position can be specified, and in the second slope image, the left anterior superior iliac spine (ASIS) is imaged so that the position can be specified. The height position of the right anterior superior iliac spine (ASIS) obtained from the first slope image is drawn on the first front image, and the right anterior superior iliac spine (ASIS) is drawn to the first front image. The height position of the left anterior superior iliac spine (ASIS) identified above and obtained from the second slope image is drawn on the second front image, and the left anterior superior iliac spine (ASIS) is 2 The process of specifying on the front image;
In the first front image, the first slope image, the second front image, and the second slope image, a right acetabular position point, a left acetabular position point, and a sciatic unilateral lowest point are identified, and the right acetabulum Paying attention to the shape of an intermediate triangle formed by connecting the lid position point, the left acetabular position point, and the lowest point on the one side of the ischial bone, the first front image, the first slope image, the second front image, and the Identical coordinates representing the first front image, the first slope image, the second front image, and the second slope image based on the fact that each of the intermediate triangles in the second slope image is the same. An intermediate coordinate system is introduced, and the information in the intermediate coordinate system is used, and the left anterior superior iliac spine (ASIS) in the second front image and the second slope image is represented by the first front image and the first image. While specifying on one slope image, the first positive And specifying the right anterior superior iliac spines in the image and the first inclined surface image (ASIS) on the second front image and the second inclined surface image,
A first image set including the first front image and the first slope image in which the right anterior superior iliac spine (ASIS) and the left anterior superior iliac spine (ASIS) are specified; One image set suitable for surgery among the second front image in which osteophyte (ASIS) and the left anterior superior iliac spine (ASIS) are specified and the second image set including the second slope image Selecting as a surgical image set;
Referring to the front image and the slope image in the surgical image set, assuming that the concave portion of the acetabulum to be operated is filled with a hemispherical cup body, the diameter size of the hemispherical cup body and the contour circle of the hemispherical cup body A normal vector connecting the center of the hemispherical cup body and the bottom vertex of the hemispherical cup body, and selecting the acetabular component corresponding to the diameter size,
Referring to the front image and the slope image in the surgical image set, the ridge line of the iliac crest on the same side as the first feature point is obtained, and the intersection of the ridge line and the second plane is used as the second feature point. And a step of specifying an iliac crest point. The support tool for hip prosthesis
A sighting shaft capable of detachably holding a acetabular pin whose tip is positioned at the center position of the pelvis of the pelvis and removably holding the acetabular reamer instead of the positioned acetabular pin;
The first pelvis of the pelvis in the preoperative image data can be swiveled around a first pivot axis perpendicular to the first plane provided on the aiming shaft within a first plane including the axis of the aiming shaft. A first arm whose tip is positioned at the feature point;
In a second plane that is a predetermined distance away from the first plane and parallel to the first plane, and is pivotable about a second pivot axis that is perpendicular to the second plane provided on the aiming shaft; A second arm whose tip is positioned at a second feature point of the pelvis in the preoperative image data;
With
Based on the preoperative image data, the acetabular pin attached to the aiming shaft is made to coincide with the normal line standing at the center position of the acetabular, and the distal end portion of the first arm points to the first feature point. The first arm is positioned with respect to the first pivot axis, and the second arm is positioned with respect to the second pivot axis so that the tip of the second arm points to the second feature point. ,
The positioned first arm and the second arm are fixed in positional relation with respect to the aiming shaft, and the axis of the aiming shaft is set on the patient's pelvis so as to coincide with the normal line. The method for acquiring preoperative image data according to claim 19, wherein an acetabular reamer is substituted for the acetabular pin. 21. Acquisition of preoperative image data according to claim 20, wherein the normal vector is adopted as the normal, and the axis of the aiming shaft is set on the patient's pelvis so as to coincide with the normal vector. Method.

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