JP2012231988A - Support implement during artificial hip cup surgery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily perform reaming of an acetabular hole or in-surgery operation where an acetabular roof is set by use of a computer three-dimensional shape model prepared before surgery and by use of a simple-structure implement during the surgery.SOLUTION: This support implement during artificial hip cup surgery includes: a sighting shaft 22 holding an acetabular pins 40a- 40c positioned in acetabular indication points set in a plurality of parts of an acetabular roof of a pelvis and an acetabular bottom pin 42 positioned in the center of the acetabular bottom in a lower end part, and having a sighting part 32 crossing the axis thereof in an upper end part; a characteristic point indication shaft 24 whose lower end part is positioned at a prescribed characteristic point in the pelvis; a positioning arm 26 holding the sighting shaft 22 and the characteristic point indication shaft 24 parallel to each other, and positioning a position of the characteristic point indication shaft 24 in a direction orthogonal to the axial direction of the characteristic point indication shaft 24; and a support shaft 28 having one end swingably connected to the positioning arm 26 and the other end fixed to a prescribed characteristic point in the pelvis.

Description

  The present invention relates to an artificial hip acetabular support jig used in a surgical operation for replacing a hip joint destroyed by a disease or an injury with an artificial hip joint.

  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.

  Therefore, the object of the present invention is to solve the problems of the prior art and determine the installation position of the acetabular cup using a computer three-dimensional shape model before the operation. An object of the present invention is to provide an artificial hip joint acetabular support jig that supports the reaming of the acetabular hole and the intraoperative operation of installing the acetabular cup using the jig.

  To achieve the above object, the present invention provides an artificial hip acetabular support jig for assisting in the operation of installing a acetabular component of an artificial hip joint on the acetabulum of a patient's pelvis, The acetabular pin positioned at the acetabular instruction point set at a plurality of locations and the acetabular bottom pin positioned at the center of the acetabular bottom are held at the lower end, and the sighting has an aiming portion that intersects the axis at the upper end A shaft, a feature point indicating axis whose lower end is positioned at a predetermined feature point in the pelvis, the aiming shaft and the feature point indicating axis are held in parallel and perpendicular to the axial direction of the feature point indicating axis A positioning arm for positioning the position of the feature point indicating axis in the direction, and a support shaft having one end pivotably connected to the positioning arm and the other end fixed to a predetermined feature point in the pelvis. Features It is intended.

Explanatory drawing of the artificial hip joint used by artificial hip joint replacement surgery. The top view which shows the pelvic acetabulum in a pelvis shape three-dimensional model. The three-dimensional figure which shows the whole pelvis shape three-dimensional model. 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 artificial hip joint acetabulum operation by one Embodiment of this invention. The partial cross section side view which shows the support shaft of the support jig | tool during artificial hip joint acetabulum operation by one Embodiment of this invention. The side view which shows the support jig | tool during artificial hip joint acetabulum operation by other embodiment of this invention. The schematic diagram which shows the positional relationship of each part when the support jig | tool during an artificial hip joint acetabulum is installed in the pelvis. Explanatory drawing of the positional relationship of the aiming shaft and acetabulum of a support jig during an artificial hip acetabulum operation in a three-dimensional model of a pelvis. Explanatory drawing of the acetabulum which can be seen when looking at the aiming shaft of the support jig during the artificial hip acetabulum during operation. Explanatory drawing of the reaming operation of the acetabulum hole using the support jig | tool during an artificial hip acetabulum operation. Explanatory drawing of the position confirmation operation of the acetabular component using the support jig | tool during an artificial hip acetabulum operation. An explanatory view of a positional relationship between an aiming shaft and an acetabular component of an assisting jig during an artificial hip acetabulum operation in a three-dimensional model of a pelvis shape.

Hereinafter, an embodiment of an artificial hip acetabular support jig according to the present invention will be described with reference to the accompanying drawings.
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, FIG. 2 is a diagram showing the acetabulum in the pelvic shape three-dimensional model on the computer, and FIG. 3 is a diagram showing the entire pelvic shape three-dimensional model. In the preoperative plan, in order to evaluate the three-dimensional position of the acetabulum with a three-dimensional model of the pelvis on the computer, the three-dimensional coordinate system and the artificial hip acetabular support jig of the present invention are installed as follows. A plurality of reference points to be referred to when fixing to is set.

  2 and 3, O represents the center of the acetabulum bottom. A vector perpendicular to the hemispherical plane when passing through the center O of the acetabulum and assuming the outline of the acetabulum as a hemisphere is defined as a normal vector nc. The axes perpendicular to each other on the hemispherical plane of the acetabulum are defined as the Yc axis that is the anterior direction of the patient's body and the Zc axis that is the direction of the anterior superior iliac spine (ASIS) that is a feature point in the pelvis. There is a normal vector nc on the Xc axis.

  After setting the coordinate system in this way, reference points A, B, and C on the acetabulum are set. In this case, the reference points A, B, and C are points on the Yc-Zc plane, and are points where the acetabular pin of the aiming shaft of the assisting jig during the artificial hip acetabulum operation described below comes into contact.

  As other reference points, as shown in FIG. 3, there are anterior superior iliac spine ASIS and iliac crest point D, which are feature points particularly conspicuous in the pelvis. There are two anterior superior iliac spines ASIS in the pelvis, but the reference point is the surgical anterior superior iliac spine ASIS closer to the acetabulum to be operated on. The anterior superior iliac spine ASIS is a point to be referred to when fixing the ASIS indicating shaft of the assisting jig in the artificial hip joint acetabulum of the present invention. The iliac ridge point D is a point to be referred to when fixing the iliac ridge point indicating axis of the assisting jig during the artificial hip acetabulum.

  Next, FIG. 4 is a side view showing a support jig during a hip prosthesis acetabulum according to the present embodiment, and FIG. 5 is a plan view showing a support jig during a hip prosthesis acetabulum.

  4 and 5, the assisting jig during the artificial hip joint acetabulum of this embodiment is roughly divided into an aiming shaft 22, an ASIS indicating shaft 24, a positioning arm 26 for positioning the ASIS indicating shaft 24, and a healing jig. A support shaft 28 that is a support column of the tool is used as a main component.

  First, an aiming fixing frame 30 curved in a semicircular shape is fixed to one end side of the positioning arm 26. An aiming shaft 22 having the following configuration is attached to the aiming fixing frame 30 at a right angle to the longitudinal direction of the positioning arm 26.

  Four arrow blades 29 are fixed to the upper end portion of the aiming shaft 22 so as to form a cross, and the aiming cylinder 32 is held coaxially with the aiming shaft 22 by these arrow feathers 29, so that the aiming portion Is configured. As shown in FIG. 5, a fixed piece 33 is attached to the aiming cylinder 32 so as to protrude. The boss portion 34 of the aiming fixing frame 30 is provided with a fixing pin 35 and a fixing screw 36 so as to sandwich the fixing piece 33. The aiming cylinder 32 can be fixed to the aiming fixing frame 30 by screwing the fixing screw 36 into the boss portion 34, and conversely, the aiming cylinder 32 can be detached from the aiming fixing frame 30 by returning the fixing screw 36. It is like that.

  On the other hand, a trident pin holder 38 is detachably fixed to the lower end of the aiming shaft 22. Three acetabular pins 40a, 40b, and 40c are fixed to the pin holder 38 by knurled knobs 41, respectively. In this case, the acetabular pins 40 a, 40 b, and 40 c are arranged 120 ° symmetrically with respect to the axis of the aiming shaft 22. These three acetabular pins 40a, 40b, and 40c are positioned so as to contact the reference points A, B, and C of the acetabulum in the actual patient's pelvis.

  Further, the acetabular pins 40a, 40b, 40c are movably fitted to the fixed pieces 39, respectively, and the lengths of the acetabular pins 40a, 40b, 40c protruding from the pin holder 33 can be adjusted. A mortar bottom indicating pin 42 is fixed to the bottom surface of the pin holder 38 so that the axis of the aiming shaft 22 coincides with the axis. When removing the pin holder 38 from the aiming shaft 22, it can be removed by loosening the knurled knob 43.

  As shown in FIG. 5, when the aiming cylinder 32 is looked into from above, it appears that the center of the pin holder 38 and the intersection of the arrow feathers 29 forming a cross coincide with each other.

  Next, the support shaft 28 is connected to the aiming fixed frame 30 through a hinge pin 44 so as to be swingable. In this embodiment, as shown in FIG. 6, the support shaft 28 is hollow, and the iliac crest indicating shaft 46 is inserted so as to be movable in the axial direction. The iliac crest indicating shaft 46 can be adjusted in length extending from the support shaft 28 by a knurled knob 47. A plate 49 for attaching a pin to the pelvis and fixing the iliac crest indicating shaft 46 to the pelvis is attached to the tip of the iliac crest indicating shaft 46. In the support shaft 28, a support column 48 is integrally formed at a substantially right angle, and a fixing piece 50 for fixing the iliac crest indicating shaft 46 is attached to the support column 48.

  Next, the ASIS instruction shaft 24 will be described. As shown in FIG. 4, the positioning arm 26 has upper and lower two elongated parallel guide plates 52a and 52b, and a slide member 54 is slidably engaged along the guide plates 52a and 52b. ing. The ASIS indicating shaft 24 is supported at a right angle to the longitudinal direction of the positioning arm 26 so as to be inserted into the slide member 54. As shown in FIG. 5, the guide plates 52 a and 52 b have a long groove 56 formed in the longitudinal direction, and the ASIS indicating shaft 24 along with the slide member 54 extends in the longitudinal direction of the positioning arm 26. Is also possible.

  A male screw 57 is formed on the outer periphery of the upper portion of the ASIS indicating shaft 24, and adjustment knobs 58 and 59 made of knurled nuts are screwed into the male screw 57. By using the adjustment knobs 58 and 59, the length from the positioning arm 26 to the tip of the ASIS instruction shaft 24 can be adjusted, and the ASIS instruction shaft 24 can be fixed. In this embodiment, the ASIS indicating shaft 24 is engraved with a scale 60 indicating its length. Similarly, a scale 62 is engraved along the long groove 56 of the positioning arm 26. This scale 62 indicates the distance between the aiming shaft shaft 22 and the ASIS indicating shaft 24. A fixing piece 64 for fixing the ASIS indicating shaft 24 is attached to the tip of the ASIS indicating shaft 24 via a knurled knob 63.

  The ASIS indicating shaft 24 as described above is attached to the positioning arm 26 so as to be parallel to the aiming shaft 22.

  7 is an embodiment in which an auxiliary support shaft 66 is added in addition to the aiming shaft 22, the ASIS indicating shaft 24, and the support shaft 28. In order to make the jig more stable, an auxiliary support shaft 66 may be added as in this embodiment.

  The artificial hip acetabular support jig according to the present embodiment is configured as described above. Next, operations and effects will be described in relation to the usage in the hip replacement surgery.

Preoperative planning On the computer, a three-dimensional model of the pelvis is constructed on the basis of the CT data of the patient, and the position where the acetabular component 16 of the artificial hip joint is installed using the three-dimensional model of the pelvis. As shown in FIGS. 2 and 3, the normal vector nc, the three-dimensional coordinate system, and the artificial hip acetabular support jig (hereinafter referred to as an intraoperative support jig) of the present invention are determined as shown in FIGS. An anterior superior iliac spine ASIS, reference points A, B, and C in the acetabulum and iliac crest points D, which are reference points to be referred to when fixing to the pelvis, are set.

  First, in a pelvic shape three-dimensional model on a computer, reference points such as the anterior superior iliac spine ASIS, reference points A, B, C, and iliac crest point D, an aiming shaft 22 that constitutes an intraoperative support jig, and ASIS The positional relationship between the indicating shaft 24 and the support shaft 28 is as shown in FIG.

  The tips of the three acetabular pins 40a, 40b, 40c at the lower end of the aiming shaft 22 are positioned at the reference points A, B, C on the inner wall of the acetabulum, and the aiming shaft 22 Is positioned in a direction that coincides with the normal vector nc set to. The lower end of the ASIS indicating shaft 24 is positioned on the anterior superior iliac spine ASIS. The tip of the iliac crest support shaft 46 at the lower end of the support shaft 28 is positioned on the iliac crest point D.

  At this time, since the aiming shaft 22 and the ASIS indicating shaft 24 are parallel, the distance L between the center O of the acetabular base and the anterior superior iliac spine ASIS is a positioning that supports the aiming shaft 22 and the ASIS indicating shaft 24. It becomes equal to the arm length L ′ of the arm 26.

  Therefore, a distance L between the center O of the acetabular base and the anterior superior iliac spine ASIS is obtained based on a pelvic shape three-dimensional model on a computer. Further, in FIG. 9, the position of the center O ′ on the hemispherical plane of the acetabulum is obtained, and the distances from the center O ′ to the reference points A, B, and C are obtained.

Next, the intraoperative support jig is adjusted according to these distances obtained above.
4 and 5, the ASIS indicating shaft 24 is slid together with the slide member 54 while looking at the scale 62 so that the distance L is equal to the distance L between the center O of the acetabular base and the anterior superior iliac spine ASIS. The ASIS indicating shaft 24 is fixed.

  Similarly, each of the acetabular pins 40a, 40b, and 40c is adjusted so that the distance to the tip coincides with the distance from the center O 'to the reference points A, B, and C, respectively.

Installation of support jig during operation
Next, FIG. 9 shows a three-dimensional model of a pelvis shape on a computer, and acetabular pins 40a, 40b, and 40c at the lower end of the aiming shaft 22 of the intraoperative support jig are used as reference points A, B, and C on the acetabular inner wall. FIG. 6 is a diagram simply showing an image displayed by synthesizing CAD data of the aiming shaft 22 on a computer as to how the aiming cylinder 32 looks when viewed from above.
When the acetabular pins 40a, 40b, and 40c are positioned at the reference points A, B, and C on the acetabulum of the patient's pelvis, the axis of the aiming shaft 22 is relative to the normal vector nc of the acetabulum. If they match, it should look like FIG.

  If the axis of the aiming shaft 22 is inclined with respect to the normal vector nc of the acetabulum, or the acetabular pins 40a, 40b, 40c are not accurately positioned with respect to the reference points A, B, C The appearance differs between FIG. 9 and FIG.

  Therefore, when the intraoperative support jig having been adjusted as described above is installed on the patient's pelvis according to the preoperative plan, each reference point A, B, C is indicated when the aiming shaft 22 is actually viewed from above. If the positional relationship between the acetabular pins 40a, 40b, 40c and the aiming cylinder 32 and the arrow feathers 29 is the same as the model image on the preoperative plan computer shown in FIG. 9, the intraoperative support jig is correctly positioned. That's right.

  After confirming that the intraoperative support jig has been accurately positioned in this way, a pin is inserted into the fixing piece 64 of the ASIS indicating shaft 24 and the fixing piece 49 of the iliac ridge indicating shaft 46 and fixed to the pelvis.

Intraoperative operation Next, an intraoperative operation performed using an intraoperative support jig will be described. The main intraoperative operations include reaming the acetabular hole, installing the outer shell 19 and inner cup 20 of the acetabular component 16 of the artificial joint on the pelvis, and confirming the installation of the acetabular component 16.

  First, FIG. 11 shows a acetabular hole reaming operation. The position of the reamer shaft 70 is managed by an intraoperative support jig using a reaming instrument having a reamer 72 attached to the tip of the reamer shaft 70.

  When reaming the acetabular hole, the aiming shaft 22 is removed by the intraoperative support jig. Instead, during the reaming, the reamer shaft 70 is positioned at the center of the arc of the semicircular aiming fixed frame 30 and the reamer shaft 70 is managed so as to be kept parallel to the ASIS indicating shaft 24. . By managing the posture of the reamer shaft 70 in this way, the reamer shaft 70 is maintained in a state that coincides with the normal vector nc of the acetabulum, so that it is easy to ream the acetabular hole as planned before the operation. Become.

  After the reaming is completed, the outer shell 19 is first inserted into the acetabular hole among the parts constituting the acetabular component 16 by using a known attachment tool (not shown). After the outer shell 19 is attached, the inner cup 20 is attached to the outer shell 19 using an inner cup inserter (not shown). During the operation of installing the acetabular component 16, the aiming shaft 22 is removed from the intraoperative support jig, so that the installation operation is not hindered.

After the acetabular component 16 is placed on the pelvis in this way, it is confirmed whether or not the placement is correctly performed using an intraoperative support jig as follows.
In FIG. 12, the pin holder 38 that holds the acetabular pins 40 a, 40 b, 40 c is removed from the lower end portion of the aiming shaft 22, and a hemispherical ball member 74 that fits into the inner cup 20 is used instead of the pin holder 38. It is attached and the length of the aiming shaft 22 is adjusted to the length required in the preoperative plan.

  In this case, when the ball member 74 is attached to the aiming shaft 22 and this ball member 74 is fitted to the inner cup 20, how the aiming shaft 22 looks when viewed from above is expressed by a pelvic shape three-dimensional model. Based on this, an image is created on the computer. For example, FIG. 13 is an example of the image.

  Therefore, when the aiming shaft 22 is viewed from above, if it matches the model image on the preoperative plan computer shown in the figure, the acetabular component 16 is correctly placed on the pelvis.

  By installing the intraoperative support jig on the pelvis as described above, the acetabular component can be accurately installed while being compared with the model image obtained in the preoperative plan.

Other methods of intraoperative operation In the intraoperative operation performed using the intraoperative support jig described above, the intraoperative support jig shown in FIG. 4 is used, but the intraoperative support jig of the embodiment shown in FIG. 7 is used. In this case, the acetabular hole may be reamed as follows.

  In the intraoperative support jig of FIG. 7, an auxiliary support shaft 66 is added, and the auxiliary support shaft 66 is a hollow shaft through which a steel wire can pass. In preparation for reaming, a steel wire is applied to the patient's pelvis using the auxiliary support shaft 66 as a guide. The aiming shaft 22 is not intentionally removed from the intraoperative support jig, and when the steel wire is properly hit so as to be parallel to the normal vector nc, the entire intraoperative support jig is removed from the pelvis while leaving the steel wire. It will be.

On the other hand, since the remaining steel wire is parallel to the normal vector nc, the mortar hole is reamed by a simple method while managing the posture of the reamer shaft based on this steel wire. Also good.
About the reaming of a acetabular hole, you may make it as follows using said steel wire. That is, after placing a steel wire on the patient's pelvis as described above, the intraoperative support jig is removed leaving the steel wire. Instead, a simple reaming jig similar in shape to the semicircular aiming fixing frame 30 of the intraoperative support jig is attached to the steel wire, and the posture of the reaming shaft is managed using this reaming jig. However, the acetabular hole may be reamed.
As described above, the present invention has been described with reference to the preferred embodiment. However, the intraoperative operation using the intraoperative support jig is not limited to the above embodiment, and may be combined with a conventionally used instrument. Therefore, various intraoperative operations are possible.

  DESCRIPTION OF SYMBOLS 10 ... Pelvis, 12 ... Femur, 14 ... Femoral stem, 16 ... Acetabular component, 22 ... Aiming shaft, 24 ... ASIS indicating axis, 26 ... Positioning arm, 28 ... Support shaft, 29 ... Arrow feather, 30 ... Aiming Fixed frame, 32 ... sighting cylinder, 38 ... pin holder, 40a, 40b, 40c ... acetabular pin, 46 ... iliac crest indicating axis, ASIS ... anterior superior iliac spine, A, B, C ... reference points on acetabulum , D ... iliac crest, nc ... normal vector

Claims (7)

An artificial hip acetabular support jig for assisting in the operation of installing an acetabular component of an artificial hip joint on the acetabulum of a patient's pelvis,
The lower end of the acetabular pin positioned at the acetabular indication point set in the pelvis acetabulum and the center of the acetabular base are held at the lower end, and the upper end intersects with the axis. An aiming shaft having an aiming part;
A feature point indicating axis in which a lower end portion is positioned at a predetermined feature point in the pelvis;
A positioning arm for holding the aiming shaft and the feature point indicating axis in parallel and positioning the position of the feature point indicating axis in a direction perpendicular to the axial direction of the feature point indicating axis;
A support shaft, one end of which is pivotably connected to the positioning arm and the other end is fixed to a predetermined feature point in the pelvis;
A support jig for artificial hip joint acetabular surgery, characterized by comprising:   The hip support acetabular support jig according to claim 1, wherein the aiming shaft is detachably attached to an aiming fixing frame provided on the positioning arm.   2. The artificial hip acetabular support jig according to claim 1, wherein a pin holder for holding the acetabular pin and the acetabular bottom pin is detachably attached to a lower end portion of the aiming shaft.   The artificial hip joint acetabular support jig according to claim 1, wherein the acetabular indication point is set on a plane perpendicular to a normal vector defined in the acetabulum.   The artificial hip acetabulum according to claim 3, wherein a ball member that can be attached to a acetabular component installed on the pelvis can be attached to the lower end portion of the aiming shaft in place of the pin holder. Intraoperative support jig.   2. The artificial hip acetabular support jig according to claim 1, wherein the feature point on the pelvis where the feature point indicating shaft is positioned is an anterior superior iliac spine.   The artificial hip acetabular support jig according to claim 1, wherein the feature point on the pelvis where the support shaft is positioned is an iliac crest point.

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